A screen to the plasma (Plasma Display Panel - PDP) is a type of large flat screen hour commonly used for screen television (typically over to the 32 inches). Many small cells posizionate in means to two panels of glass maintain one inert noble gas mixture (neon and xeno). The gas in the cells comes electrically transformed in a plasma, which then it excites phosphorus to emit light.
Saturday, February 9, 2008
Plasma Display Panel
A screen to the plasma (Plasma Display Panel - PDP) is a type of large flat screen hour commonly used for screen television (typically over to the 32 inches). Many small cells posizionate in means to two panels of glass maintain one inert noble gas mixture (neon and xeno). The gas in the cells comes electrically transformed in a plasma, which then it excites phosphorus to emit light.
History Of The Plasma
The screen to the plasma has been invented inthe University of the Illinois to Urbana-Champaign from Donald L. Bitzer, H. Gene Slottow, and from the student Robert Willson in 1964 for the PLATO System Computer. It originates them monochromium plated panels us (of orange or green usual, to times yellow) had an impulse of popolarità in years ' 70 since the screen was sturdy and they did not need neither of memory neither of circuitry electronic for the refresh ofthe image. It followed in years ' 80 along period of decline of the sales when the memories to semiconductor rendered cathodic tube screen CRT () more economic than those to the plasma. That although, the relatively great dimensions of a screen to the plasma and the thin profile, rendered screen attractive for giving an image of high profile such, as it knows them of income and stock markets.
In 1983 IBM introduced black an orange monochromatic screen on of 19 inches (model 3290 "information panel") which she was in a position to showing four blots of it virtual (VM) IBM 327 in session of finishes them. The factory was transferred in 1987 in the emergent company Plasmaco, than Larry F. Weber, one of the students of Bitzer, founded with Stephen Globus and James Kehoe, that it was the manager of the factory of IBM. In 1992 the Fujitsu introduced the first screen of 21 inches to colors to the world. It was a hybrid, based on the screen to the plasma created tothe University of the Illinois andNHK STRL (the laboratory of the tv Japanese), obtaining one advanced brightness. In 1996 the Matsushita Electrical Industries (Panasonic) bought the Plasmaco, its technology to colors AC and the factory American. In 1997 the Pioneer began to sell the first television set to the plasma to the public.
Only recently, the greater detail in the dark scenes, a smaller effect wake, a greater phantom than colors and a wider visual angle has rendered the screen to the plasma the more popular shape for televisions HDTV, to the damages of screen LCD. For along period it has been believed that technology LCD was only adapted for the smaller televisions, accomplice also the economic impossibility of the display to the plasma to come down in diagonal, and it could not instead have competed in the segment of the great diagonals, that is from the 40 inches in on.
However, from then, the improvements of the technology LCD, accomplices also the great investments in search, have strongly reduced the gap technological. The prices in reduction, the higher to parity than diagonal, important resolutions for the HDTV, the inferior weight, the phantom of colors increased, and finally a consumption inferior electrical worker, render them competiti to you against the screen to the plasma in all the segments of market. To the end of the 2006 it has been already noticed that screen LCD is exceeding in the sales those to the plasma, particularly in that segment of 40"and advanced where historically strong predominanza of screen to the plasma was one. Industrial other trend is the consolidation of the constructors of screen to the plasma, with approximately fifty various ones marks, but only five great producers.
Characteristic generates them
The screen to the plasma is luminous (1000 lux or more for the modules), has a wide one gamut of colors and can be produced in greatest dimensions, until 262 cm (103 inches) diagonally. They have a greatest level of black "dark-room", creating "black perfect" the desirable one in order to watch films. The panel of the screen is wide only 6 centimeters, while the width total, included the part electronic that manages the screen, is inferior to the 10 centimeters. The screen to the plasma how much consumes much Watt for square meter the cathodic tubes or televisions AMLCD. The consumption is influenced from that it is being watched: luminous scenes, like, in order to make an example, a sport event, will absorb much more watt than a film with many nocturnal scenes. Nominal measures indicate approximately 400 watt for one 50"screen.
The duration of a screen to the plasma of last generation is estimated in 60 000 hours (27 years with 6 hours of uses to the day). More just, this is the esteem of half of the life of the screen, the point in which the image it is degraded to half of its brightness originates them. He is still guardabile after this point, than but it comes generally considered the end of the life works them of the screen.
The screen that they compete with includes the CRT, OLED, AMLCD, DLP, SED-tv and screen plates field emission. The main advantage of the technology for screen to the thin plasma is that large screen can be produced one much using material much. Every Siccome pixel comes ignited individually, the image is much luminous one and has a wide visible angle.
In 1983 IBM introduced black an orange monochromatic screen on of 19 inches (model 3290 "information panel") which she was in a position to showing four blots of it virtual (VM) IBM 327 in session of finishes them. The factory was transferred in 1987 in the emergent company Plasmaco, than Larry F. Weber, one of the students of Bitzer, founded with Stephen Globus and James Kehoe, that it was the manager of the factory of IBM. In 1992 the Fujitsu introduced the first screen of 21 inches to colors to the world. It was a hybrid, based on the screen to the plasma created tothe University of the Illinois andNHK STRL (the laboratory of the tv Japanese), obtaining one advanced brightness. In 1996 the Matsushita Electrical Industries (Panasonic) bought the Plasmaco, its technology to colors AC and the factory American. In 1997 the Pioneer began to sell the first television set to the plasma to the public.
Only recently, the greater detail in the dark scenes, a smaller effect wake, a greater phantom than colors and a wider visual angle has rendered the screen to the plasma the more popular shape for televisions HDTV, to the damages of screen LCD. For along period it has been believed that technology LCD was only adapted for the smaller televisions, accomplice also the economic impossibility of the display to the plasma to come down in diagonal, and it could not instead have competed in the segment of the great diagonals, that is from the 40 inches in on.
However, from then, the improvements of the technology LCD, accomplices also the great investments in search, have strongly reduced the gap technological. The prices in reduction, the higher to parity than diagonal, important resolutions for the HDTV, the inferior weight, the phantom of colors increased, and finally a consumption inferior electrical worker, render them competiti to you against the screen to the plasma in all the segments of market. To the end of the 2006 it has been already noticed that screen LCD is exceeding in the sales those to the plasma, particularly in that segment of 40"and advanced where historically strong predominanza of screen to the plasma was one. Industrial other trend is the consolidation of the constructors of screen to the plasma, with approximately fifty various ones marks, but only five great producers.
Characteristic generates them
The screen to the plasma is luminous (1000 lux or more for the modules), has a wide one gamut of colors and can be produced in greatest dimensions, until 262 cm (103 inches) diagonally. They have a greatest level of black "dark-room", creating "black perfect" the desirable one in order to watch films. The panel of the screen is wide only 6 centimeters, while the width total, included the part electronic that manages the screen, is inferior to the 10 centimeters. The screen to the plasma how much consumes much Watt for square meter the cathodic tubes or televisions AMLCD. The consumption is influenced from that it is being watched: luminous scenes, like, in order to make an example, a sport event, will absorb much more watt than a film with many nocturnal scenes. Nominal measures indicate approximately 400 watt for one 50"screen.
The duration of a screen to the plasma of last generation is estimated in 60 000 hours (27 years with 6 hours of uses to the day). More just, this is the esteem of half of the life of the screen, the point in which the image it is degraded to half of its brightness originates them. He is still guardabile after this point, than but it comes generally considered the end of the life works them of the screen.
The screen that they compete with includes the CRT, OLED, AMLCD, DLP, SED-tv and screen plates field emission. The main advantage of the technology for screen to the thin plasma is that large screen can be produced one much using material much. Every Siccome pixel comes ignited individually, the image is much luminous one and has a wide visible angle.
Characteristic generates them
The screen to the plasma is luminous (1000 lux or more for the modules), has a wide one gamut of colors and can be produced in greatest dimensions, until 262 cm (103 inches) diagonally. They have a greatest level of black "dark-room", creating "black perfect" the desirable one in order to watch films. The panel of the screen is wide only 6 centimeters, while the width total, included the part electronic that manages the screen, is inferior to the 10 centimeters. The screen to the plasma how much consumes much Watt for square meter the cathodic tubes or televisions AMLCD. The consumption is influenced from that it is being watched: luminous scenes, like, in order to make an example, a sport event, will absorb much more watt than a film with many nocturnal scenes. Nominal measures indicate approximately 400 watt for one 50"screen.
The duration of a screen to the plasma of last generation is estimated in 60 000 hours (27 years with 6 hours of uses to the day). More just, this is the esteem of half of the life of the screen, the point in which the image it is degraded to half of its brightness originates them. He is still guardabile after this point, than but it comes generally considered the end of the life works them of the screen.
The screen that they compete with includes the CRT, OLED, AMLCD, DLP, SED-tv and screen plates field emission. The main advantage of the technology for screen to the thin plasma is that large screen can be produced one much using material much. Every Siccome pixel comes ignited individually, the image is much luminous one and has a wide visible angle.
The duration of a screen to the plasma of last generation is estimated in 60 000 hours (27 years with 6 hours of uses to the day). More just, this is the esteem of half of the life of the screen, the point in which the image it is degraded to half of its brightness originates them. He is still guardabile after this point, than but it comes generally considered the end of the life works them of the screen.
The screen that they compete with includes the CRT, OLED, AMLCD, DLP, SED-tv and screen plates field emission. The main advantage of the technology for screen to the thin plasma is that large screen can be produced one much using material much. Every Siccome pixel comes ignited individually, the image is much luminous one and has a wide visible angle.
Details on the operation
The neon and gases xeno in a television set to the plasma are contained in hundred of migliaia of small cells posizionate between two panels of glass. Also of the long electrodes they come inserted between the glass panels, and behind the cells. The indirizzamento electrodes are behind the cells, along the panel of posterior glass. The transparent electrodes of the screen, that they are encircles from dielectric insulator to you and covered material of a protecting layer in magnesium oxide, are mount to you in front of the cells, along the front glass. The loaded circuitry of control the electrodes that are intercrossed to a cell, creating a potential difference them between and behind provoking to the ionization of gases and the plasma formation ; when the Ionian ones of the gas head towards the electrodes and collidono they come emitted of photons.
In a monochromatic screen, the ionizzante state can be maintained applying to a voltage of low level between all the horizontal and vertical electrodes, also when the ionization voltage comes removed. In order to cancel a cell, all the tension comes removed from the electrodes. This type of panel has an intrinsic memory and it does not use phosphorus. One small nitrogen amount comes added to neon in order to increasethe hysteresis.
In the panels to colors, the back of every cell is covered with a phosphorus. The emitted ultraviolet photons from the plasma excite these phosphorus for giving colorful light. Every cell is therefore comparable to one fluorescent lamp.
Every pixel it is made of three sottocelle separate, ognuna with phosphorus of various colors. A sottocella it has phosphorus for the red light, one for the green light and the other for the blue light. These colors join together in order to create the color total of the pixel, analogous to the Triad computers (to three colors; for technical details you see pixel, technical aspects) or to screen CRT. Varying the current impulses that slide through the various cells migliaia of times to the second, the control system can increase or diminish the intensity of every every color of sottocella in order creating billions of various combinations of green, red and blue. In this way the control system can produce the greater part of the visible colors. The display to the plasma they use same phosphorus of the CRT, that door to one reproduction of the colors extremely taken care of.
In a monochromatic screen, the ionizzante state can be maintained applying to a voltage of low level between all the horizontal and vertical electrodes, also when the ionization voltage comes removed. In order to cancel a cell, all the tension comes removed from the electrodes. This type of panel has an intrinsic memory and it does not use phosphorus. One small nitrogen amount comes added to neon in order to increasethe hysteresis.
In the panels to colors, the back of every cell is covered with a phosphorus. The emitted ultraviolet photons from the plasma excite these phosphorus for giving colorful light. Every cell is therefore comparable to one fluorescent lamp.
Every pixel it is made of three sottocelle separate, ognuna with phosphorus of various colors. A sottocella it has phosphorus for the red light, one for the green light and the other for the blue light. These colors join together in order to create the color total of the pixel, analogous to the Triad computers (to three colors; for technical details you see pixel, technical aspects) or to screen CRT. Varying the current impulses that slide through the various cells migliaia of times to the second, the control system can increase or diminish the intensity of every every color of sottocella in order creating billions of various combinations of green, red and blue. In this way the control system can produce the greater part of the visible colors. The display to the plasma they use same phosphorus of the CRT, that door to one reproduction of the colors extremely taken care of.
Relationship of contrast
The contrast relationship is a intrinsic value del display, seppur employee from external factors like calibration and brightness it acclimatizes them, and it is obtained more measuring the relationship between the more luminous part and that buia than one image, that is the white man, and the black one. Generally, greater values indicate one more realistic image, in how much sintomatica of one probable ability to the screen to show a high number of discreet steps of gradazioni. The relationships of contrast for the screen to the plasma are pubblicizzati like rather high, in around of the 10.000:1. On the paper this turns out in a good advantage of the plasma regarding the other technologies of display. Not existing industrial outlines in order to measure the contrast relationship, the greater part of the producers adopts what it guarantees values more elevates to you, standard VESA (called also ON/OFF), that totally black image consists in the visualization of one, continuation from one totally white woman. Less used he is instead the standard PANTS, that he uses an image of test to chessboard where black the darker and clearer white men are measured simultaneously, in how much gives back very inferior values, difficultly advanced to 600:1. The two measurements can are considered complementary, in how many ends, the VESA are end too much blanda, representing a visual scene practically never verifiable, while IT PANTS it is nearer what it can it are defined like the visual scene worse. You attend also the cases in which the producers they improve ulteriorly, in artificial way, the contrast relationship, in order then to be able some to boast greater values, opportunely acting in the settaggi of brightness and contrast. However, a relationship of generated contrast in this way is misleading, since for guilt of the settaggi it alters the images to you would be essentially inguardabili.
The technology to the base of the screen to the plasma helps to obtain high relationships of contrast. Similarly to the CRT, the screen to the plasma can obtain black nearly a every total completely extinguishing single cella/pixel, seppur then in truth this does not happen, in how much the cells always are held under load and ready to the use. This contrasts with technology LCD, where the black points, generate to you from a method of polarization of the light, are not in a position to completely blocking the coming from light from the retroilluminazione. However, the technology to the plasma has anch' it of the points weak people, in the first place making to work a screen to the maximum brightness meaningfully reduces the life of the panel. For this reason many owners leave the settaggi of the brightness a lot under to the maximum, that however advanced brightness of that one of the cathodic tube screen guarantees one. Finally, the display to the plasma they find themselves in difficulty in the images where there are many clear zones, the cells correspondents to those points need of much energy, going to influence the general brightness of the panel, than cove leggermente.
The technology to the base of the screen to the plasma helps to obtain high relationships of contrast. Similarly to the CRT, the screen to the plasma can obtain black nearly a every total completely extinguishing single cella/pixel, seppur then in truth this does not happen, in how much the cells always are held under load and ready to the use. This contrasts with technology LCD, where the black points, generate to you from a method of polarization of the light, are not in a position to completely blocking the coming from light from the retroilluminazione. However, the technology to the plasma has anch' it of the points weak people, in the first place making to work a screen to the maximum brightness meaningfully reduces the life of the panel. For this reason many owners leave the settaggi of the brightness a lot under to the maximum, that however advanced brightness of that one of the cathodic tube screen guarantees one. Finally, the display to the plasma they find themselves in difficulty in the images where there are many clear zones, the cells correspondents to those points need of much energy, going to influence the general brightness of the panel, than cove leggermente.
Burn-in of the screen
With screen electronic it bases to you on phosphorus (included those to cathode rays and the plasma), the visualization extended in the time of a bar of menu or other graphical elements it can create images ghost of these objects. This because of the fact that the members to phosphorus who emit the light forgiveness their brightness with the use. Like result, when some areas of the screen come used more than frequent than others, in the time the areas that have lost brightness become visible to eye knot, creating the effect called burn-in. While the ghost image is the more obvious effect, a more common result is that the quality of the image will continuously decrease gradually and while the brightness variations are developed, creating an effect "mud" in the visualized image.
The screen to the plasma exhibits also an other type of alteration of the image, which it comes to times confused with the damage give burn-in. In this way, when a group of pixel comes ignited to high brightness (visualizing the white man, as an example) for along period of time, it loads it is constructed in the structure of the pixel and becomes visible a ghost image. However, to difference of burn-in, this it loads constructed is transitory and autocorregge when the screen is extinguished sufficiently for a period along, or after to have visualized accidental television images.
The screen to the plasma exhibits also an other type of alteration of the image, which it comes to times confused with the damage give burn-in. In this way, when a group of pixel comes ignited to high brightness (visualizing the white man, as an example) for along period of time, it loads it is constructed in the structure of the pixel and becomes visible a ghost image. However, to difference of burn-in, this it loads constructed is transitory and autocorregge when the screen is extinguished sufficiently for a period along, or after to have visualized accidental television images.
Cathodic tube
The term cathode-ray tube, more commonly cathodic tube or CRT (acronym of the English term Cathode Ray Tube), commonly indicates the used technology for the visualization in the monitor and the televisori, that it consists ad hoc in the convogliare of the cathode rays on an sensitive surface, that reconstructs the visible image. The measure of monitor CRT is carried out on the diagonal of the visible area, in Inches.
The technology to the base cathodic tube was developed in 1897 from the German physicist Karl Ferdinand Braun who realized the first oscilloscope, while the first prototype of the type used in the modern televisori was realized from American inventor Philo Farnsworth.
Currently the technology of the cathodic tube is destined to a progressive obsolescence in favor of the technologies to the plasma, to crystals liquids and OLED, the less cumbersome, thriftier in the consumption electrical worker and with production costs in continuous reduction.
The cathodic tube monitor introduces the advantage, regarding the concurrent technologies, of a better speed than reaction (or minor appreciatedin the image and a lot, latenza use videogiochi) with more faithful colors.
The technology to the base cathodic tube was developed in 1897 from the German physicist Karl Ferdinand Braun who realized the first oscilloscope, while the first prototype of the type used in the modern televisori was realized from American inventor Philo Farnsworth.
Currently the technology of the cathodic tube is destined to a progressive obsolescence in favor of the technologies to the plasma, to crystals liquids and OLED, the less cumbersome, thriftier in the consumption electrical worker and with production costs in continuous reduction.
The cathodic tube monitor introduces the advantage, regarding the concurrent technologies, of a better speed than reaction (or minor appreciatedin the image and a lot, latenza use videogiochi) with more faithful colors.
Description and operation
The structure of the cathodic tube drift directly from the cold cathode diode valve , in its turn derived from the tube of Crookes, to which covered screen of fluorescent material is added one, also called Tube of Brown. In 1922 the first version was developed trades them to hot cathode from part of J. B. Johnson and H. W. Weinhart, of the Electric Western.
The cathode is a small heated metallic element to the incandescence that emits electrons for termoelettronico effect. To the inside of the cathodic tube, in which it has been practiced an empty one pushed, these electrons come directed in a bundle (cathode rays) for means of one elevated potential difference them electrical worker between cathode and anode, with the aid of other magnetic electric fields or opportunely arranged in order to focus the bundle accurately. The beam (said also electronic paint-brush) comes deflected from the action of magnetic fields (Force of Lorentz) so as to to succeed in to hit a point any on the internal surface of the screen, the anode. This surface is covered of fluorescent material (sayings phosphorus, in kind metals of transition or rare-earths) that excited from the energy of electrons it emits light.
In the televisori and the monitor the surface scandita second a predefined matrix of successive lines, call raster, and the image is created modulating the intensity of the electronic bundle second the course of marks them video. The scansion is obtained having the bundle for means of the variable magnetic field generated from opportune fixed electromagnets on the "neck" of the tube (electromagnetic deflection), that they constitute the so-called one giogo of deflection. I affixed electronic circuits to you pilot the electromagnets of the giogo so as to to carry out one scansion in perfect synchrony.
Inthe oscilloscope instead the intensity of the electronic paint-brush he is constant, while the deflection comes carried out based on marks them arbitrary. Usually the horizontal deflection happens proportionally to the time, second a configurabile base from the customer, while the vertical one is proporziona them to marks them to analyze.
In these tubes, plus tight and long, the deflection comes orthogonally carried out for means of an electric field generated from plates disposed to the inside of the tube (electrostatic deflection). This technique is preferibile in the oscilloscope because fast one concurs a variation much of marks them of deflection, that instead it is limited within precise margins fromthe inductance of the electromagnets.
The cathode is a small heated metallic element to the incandescence that emits electrons for termoelettronico effect. To the inside of the cathodic tube, in which it has been practiced an empty one pushed, these electrons come directed in a bundle (cathode rays) for means of one elevated potential difference them electrical worker between cathode and anode, with the aid of other magnetic electric fields or opportunely arranged in order to focus the bundle accurately. The beam (said also electronic paint-brush) comes deflected from the action of magnetic fields (Force of Lorentz) so as to to succeed in to hit a point any on the internal surface of the screen, the anode. This surface is covered of fluorescent material (sayings phosphorus, in kind metals of transition or rare-earths) that excited from the energy of electrons it emits light.
In the televisori and the monitor the surface scandita second a predefined matrix of successive lines, call raster, and the image is created modulating the intensity of the electronic bundle second the course of marks them video. The scansion is obtained having the bundle for means of the variable magnetic field generated from opportune fixed electromagnets on the "neck" of the tube (electromagnetic deflection), that they constitute the so-called one giogo of deflection. I affixed electronic circuits to you pilot the electromagnets of the giogo so as to to carry out one scansion in perfect synchrony.
Inthe oscilloscope instead the intensity of the electronic paint-brush he is constant, while the deflection comes carried out based on marks them arbitrary. Usually the horizontal deflection happens proportionally to the time, second a configurabile base from the customer, while the vertical one is proporziona them to marks them to analyze.
In these tubes, plus tight and long, the deflection comes orthogonally carried out for means of an electric field generated from plates disposed to the inside of the tube (electrostatic deflection). This technique is preferibile in the oscilloscope because fast one concurs a variation much of marks them of deflection, that instead it is limited within precise margins fromthe inductance of the electromagnets.
Maintenance
During the operation of the tube, on the surface of the screen it is induced loads electrostatics that, although it does not represent a danger for the man, provokes the powder warehouse that in the long run degrades the quality of the image. For this reason it is opportune to clean up the screen with specific products (produced periodically adapted cannot damage the been reflected covering, if present).
Because of the presence of high tension, the inside of a television apparatus attracts much powder, that it can be removed with a moderated compressed air jet, possibly to the open.
The external surface of the cathodic tube comprised between the screen and the neck is covered from one fine black powder of grafite. Its scope is to realize the armor of a condenser in a position to accumulateing and levelling generated high tension (the other armor is an analogous covering on the internal surface of the glass). This powder, that it could seem to a profane eye a simple warehouse of dirt, does not have absolutely to be removed.
Because of the presence of high tension, the inside of a television apparatus attracts much powder, that it can be removed with a moderated compressed air jet, possibly to the open.
The external surface of the cathodic tube comprised between the screen and the neck is covered from one fine black powder of grafite. Its scope is to realize the armor of a condenser in a position to accumulateing and levelling generated high tension (the other armor is an analogous covering on the internal surface of the glass). This powder, that it could seem to a profane eye a simple warehouse of dirt, does not have absolutely to be removed.
Magnetic Fields
Since the electrons come turn aside to you from the magnetic field, must be avoided to approach to magnets (es. loudspeakers) to a color screen, in how much they would provoke to the magnetization of the mask and therefore the wrong rappresentazione of the colors. Such phenomenon permane also after the removal of the magnet and the correction can be difficult.
The modern televisori and monitor implement a special coil of demagnetization that, to the ignition of the apparatus, produces a short but intense magnetic field with dampened sinusoidale course, to leave from the 50 frequency to Hz of the net electrical worker. This variable field can eliminate one modest residual magnetization. They are available also I affixed smagnetizzatori exteriors to you to use in the case the inner coil he is not effective or it lacks all. As alternative can be used a saldatore by hand that it has an integrated transformer. The manual demagnetization must progressively begin from the center, going away from the screen with movement to spiral, repeating the process until the restoration of the correct colors.
In extreme cases, in particular with magnets to neodymium-iron-boron, the magnetic field can deform the mask mechanically. This damage is irreversible and renders the cathodic tube practically unusable.
In old the black monitor in.bianco and, you deprive of mask, the problem is not placed and can be employs to you for physical demonstrations on the motion of electrons in the magnetic field, remembering but the public not to make it on the house television set!
The modern televisori and monitor implement a special coil of demagnetization that, to the ignition of the apparatus, produces a short but intense magnetic field with dampened sinusoidale course, to leave from the 50 frequency to Hz of the net electrical worker. This variable field can eliminate one modest residual magnetization. They are available also I affixed smagnetizzatori exteriors to you to use in the case the inner coil he is not effective or it lacks all. As alternative can be used a saldatore by hand that it has an integrated transformer. The manual demagnetization must progressively begin from the center, going away from the screen with movement to spiral, repeating the process until the restoration of the correct colors.
In extreme cases, in particular with magnets to neodymium-iron-boron, the magnetic field can deform the mask mechanically. This damage is irreversible and renders the cathodic tube practically unusable.
In old the black monitor in.bianco and, you deprive of mask, the problem is not placed and can be employs to you for physical demonstrations on the motion of electrons in the magnetic field, remembering but the public not to make it on the house television set!
Risk of implosion
To the inside of the tube an empty one is practiced pushed, for which the on all its surface the hydrostatic push ( 1 Kg for cmacts constantly2). This represents a cospicuo accumulates of energy upgrades them that implosion in case of damaging of the glass can get rid under shape of one. In the tubes of the modern televisori and monitor the frontal part is irrobustita with the interposizione of plastic sheets, so as to to resist to it hits and not to implodere. The remaining part of the tube and in particular the neck is instead much delicate.
In other tubes, like as an example the oscilloscopes, it does not exist I reinforce of the screen, that it comes instead protect with one put in front plastic screen.
The cathodic tube must be handled with attention and competence; it must be avoided in particular to raise it for the neck or however for the points purposely previewed.
In other tubes, like as an example the oscilloscopes, it does not exist I reinforce of the screen, that it comes instead protect with one put in front plastic screen.
The cathodic tube must be handled with attention and competence; it must be avoided in particular to raise it for the neck or however for the points purposely previewed.
Toxicity of phosphorus
In the old tubes they came employs to you for toxic material phosphorus, replaced hour from the other surest ones. The implosion or however the breach of the glass cause the dispersion of these materials. In the smaltimento of the tube account of the lead presence must be held , that a polluting one is considered.
Images blinkings
In the television apparatuses the sfarfallio produced from the continuous one I redesign of the image (50 times to the second but in interlacciato way, that is they come before designed to all the equal lines and subsequently all the uneven lines, than in practical door the 25 frequency to Hz) can in some subjects be triggering cause of epilettiche crises. They are available systems in order to reduce this risk.
High tension
The cathode-ray tubes are feed with tensions high electrical workers to you much. These tensions can much later permanere in the apparatus also in order the extinction and the logoff from the net electrical worker. To avoid therefore to open monitor or television apparatuses also to detached thorn if one adapted technical preparation is not had and however being adopted the necessary precautions (es. unloading of the tube and the condensers).
Degradation in the time
As it happens in all the tubes electron-beams, also in the CRT the efficiency of electron emission from part of the cathode, in the time stretches to diminish progressively, with consequent minor brightness of the images on the screen. In the oscilloscopes, the consequence is one smaller brightness of the trace. Cause of the degradation, is the alteration of the oxide layer deposited on the surface of the cathode and the formation on the surface of small letters lumps, true and own slags, consequence of innumerevoli the ignitions and extinctions, whose presence constitutes one screen to the flow of electrons generated. In the years in which tube CRT it was of universal use, data the elevated cost for its substitution, existed in commerce particular apparatuses calls to you "regenerative", which allowed to carry out a momentary cleaning of slags deposited on the cathode. The method consisted in applying one sufficiently high tension, between the pin connected to the connected cathode and the pin to the first grill near to it. The eventual voltaico arc that was formed, destroyed consisting slags more giving for short new time life to the tube.
Thin Film Transistor
Thin Film Transistor (TFT), in Italian thin film transistor, is a technology applied to display the plates to crystals liquids (LCD) or to OLED that come in this way it identifies to you like display to active matrix.
The fundamental difference between a TFT and a traditional panel LCD is the way in which it comes polarized the liquid crystal. In both the technologies the liquid crystal molecules are oriented once that they are subordinates to an electric field, but while in the traditional LCD a tension from the outside of the visualization panel is applied, like in a condenser, technology TFT the electric field comes applied directly in the necessary point, removing therefore the introduced parasitic abilities from I disentangle of the tracks necessary in order to catch up the dot, through note a transistor to directly realized thin film with a superficial substrate of material deposited transparent semiconductor on the inner ones of the glasses that accommodate also crystals liquids.
The more obvious advantage is in lowlands necessary currents of pilotage for the polarization of crystals, in the low tensions of polarization necessary for the commutation of the transistor and in the times of answer necessary to the fluid in order to change of state and therefore to make to journey or less the light that crosses it. All this allows to realize easily display with a high number of dot, pixel, than it would otherwise not have been possible to make.
The used technology rispecchia much close gives that anchor today used in the realization of dynamic memories (DRAM) with the difference that the single cells of the transistors come realized directly applying a conductive substrate, opportunely drug addict, directly on the glasses of the panel, rather than to work on a classic die in silicon.
The technology for the construction of active matrices OLED, has the same scope of that one of the LCD: to carry to the realization of a display to flat matrix. Substantial the differences are in the elettroluminescente element that, in this case, is represented from the OLED. To replace the LCD would allow to obtain display more performanti from all the points of view: optical, since the emission of the OLED is to 360°C; from the point of view of the consumptions, since the OLED is for its emissivo and not trasmissivo nature like in the case of the LCD; from the point of view of the construction and the flexibility. The only problem is, today, the time of life of the colors: still a time of life has not been caught up, for the blue above all, sufficiently high.
While general technology TFT was developed in the United States to leave from 1979 near the university of the Minnesota and carried in the years succeeded you to the realization of resistive and capacitive nets to the high integration for the realization of mainframe, the implementazione of this technology for the realization of LCD to active matrix must to varied Japanese industries and has been subsequently implemented and elaborated also from taiwanesi, Korean and alsolately Chinese colossus of the electronics.
The fundamental difference between a TFT and a traditional panel LCD is the way in which it comes polarized the liquid crystal. In both the technologies the liquid crystal molecules are oriented once that they are subordinates to an electric field, but while in the traditional LCD a tension from the outside of the visualization panel is applied, like in a condenser, technology TFT the electric field comes applied directly in the necessary point, removing therefore the introduced parasitic abilities from I disentangle of the tracks necessary in order to catch up the dot, through note a transistor to directly realized thin film with a superficial substrate of material deposited transparent semiconductor on the inner ones of the glasses that accommodate also crystals liquids.
The more obvious advantage is in lowlands necessary currents of pilotage for the polarization of crystals, in the low tensions of polarization necessary for the commutation of the transistor and in the times of answer necessary to the fluid in order to change of state and therefore to make to journey or less the light that crosses it. All this allows to realize easily display with a high number of dot, pixel, than it would otherwise not have been possible to make.
The used technology rispecchia much close gives that anchor today used in the realization of dynamic memories (DRAM) with the difference that the single cells of the transistors come realized directly applying a conductive substrate, opportunely drug addict, directly on the glasses of the panel, rather than to work on a classic die in silicon.
The technology for the construction of active matrices OLED, has the same scope of that one of the LCD: to carry to the realization of a display to flat matrix. Substantial the differences are in the elettroluminescente element that, in this case, is represented from the OLED. To replace the LCD would allow to obtain display more performanti from all the points of view: optical, since the emission of the OLED is to 360°C; from the point of view of the consumptions, since the OLED is for its emissivo and not trasmissivo nature like in the case of the LCD; from the point of view of the construction and the flexibility. The only problem is, today, the time of life of the colors: still a time of life has not been caught up, for the blue above all, sufficiently high.
While general technology TFT was developed in the United States to leave from 1979 near the university of the Minnesota and carried in the years succeeded you to the realization of resistive and capacitive nets to the high integration for the realization of mainframe, the implementazione of this technology for the realization of LCD to active matrix must to varied Japanese industries and has been subsequently implemented and elaborated also from taiwanesi, Korean and alsolately Chinese colossus of the electronics.
Surface-conduction electron-emitter display
S.E.D. (Surface-conduction Electron-emitter Display) is one new technology of televisori devised from Toshiba and Canon introduced to the CEATEC in October 2004.
New televisori SED must have been puttinges in production already in August of 2005 and puttinges in sale in the spring of 2006. The vice president of Toshiba instead in March of 2006 has postponed their production in the course of the 2007 and income in the market in 2008.
In single every technology SED pixel it is a microscopical cathodic tube, with luminous phosphorus that come ignited from an electron flow.
Technology SED joins the technological qualities of the cathodic tubes, like contrast and speed of answer, to the praticità of one flat screen to plasma or LCD. The energetic efficiency turns out similar to that one of a advanced LCD and to a television set to the plasma.
New televisori SED must have been puttinges in production already in August of 2005 and puttinges in sale in the spring of 2006. The vice president of Toshiba instead in March of 2006 has postponed their production in the course of the 2007 and income in the market in 2008.
In single every technology SED pixel it is a microscopical cathodic tube, with luminous phosphorus that come ignited from an electron flow.
Technology SED joins the technological qualities of the cathodic tubes, like contrast and speed of answer, to the praticità of one flat screen to plasma or LCD. The energetic efficiency turns out similar to that one of a advanced LCD and to a television set to the plasma.
Burn-in of the screen
With screen electronic it bases to you on phosphorus (included those to cathode rays and the plasma), the visualization extended in the time of a bar of menu or other graphical elements it can create images ghost of these objects. This because of the fact that the members to phosphorus who emit the light forgiveness their brightness with the use. Like result, when some areas of the screen come used more than frequent than others, in the time the areas that have lost brightness become visible to eye knot, creating the effect called burn-in. While the ghost image is the more obvious effect, a more common result is that the quality of the image will continuously decrease gradually and while the brightness variations are developed, creating an effect "mud" in the visualized image.
The screen to the plasma exhibits also an other type of alteration of the image, which it comes to times confused with the damage give burn-in. In this way, when a group of pixel comes ignited to high brightness (visualizing the white man, as an example) for along period of time, it loads it is constructed in the structure of the pixel and becomes visible a ghost image. However, to difference of burn-in, this it loads constructed is transitory and autocorregge when the screen is extinguished sufficiently for a period along, or after to have visualized accidental television images.
The screen to the plasma exhibits also an other type of alteration of the image, which it comes to times confused with the damage give burn-in. In this way, when a group of pixel comes ignited to high brightness (visualizing the white man, as an example) for along period of time, it loads it is constructed in the structure of the pixel and becomes visible a ghost image. However, to difference of burn-in, this it loads constructed is transitory and autocorregge when the screen is extinguished sufficiently for a period along, or after to have visualized accidental television images.
Relationship of contrast
The contrast relationship is a intrinsic value del display, seppur employee from external factors like calibration and brightness it acclimatizes them, and it is obtained more measuring the relationship between the more luminous part and that buia than one image, that is the white man, and the black one. Generally, greater values indicate one more realistic image, in how much sintomatica of one probable ability to the screen to show a high number of discreet steps of gradazioni. The relationships of contrast for the screen to the plasma are pubblicizzati like rather high, in around of the 10.000:1. On the paper this turns out in a good advantage of the plasma regarding the other technologies of display. Not existing industrial outlines in order to measure the contrast relationship, the greater part of the producers adopts what it guarantees values more elevates to you, standard VESA (called also ON/OFF), that totally black image consists in the visualization of one, continuation from one totally white woman. Less used he is instead the standard PANTS, that he uses an image of test to chessboard where black the darker and clearer white men are measured simultaneously, in how much gives back very inferior values, difficultly advanced to 600:1. The two measurements can are considered complementary, in how many ends, the VESA are end too much blanda, representing a visual scene practically never verifiable, while IT PANTS it is nearer what it can it are defined like the visual scene worse. You attend also the cases in which the producers they improve ulteriorly, in artificial way, the contrast relationship, in order then to be able some to boast greater values, opportunely acting in the settaggi of brightness and contrast. However, a relationship of generated contrast in this way is misleading, since for guilt of the settaggi it alters the images to you would be essentially inguardabili.
The technology to the base of the screen to the plasma helps to obtain high relationships of contrast. Similarly to the CRT, the screen to the plasma can obtain black nearly a every total completely extinguishing single cella/pixel, seppur then in truth this does not happen, in how much the cells always are held under load and ready to the use. This contrasts with technology LCD, where the black points, generate to you from a method of polarization of the light, are not in a position to completely blocking the coming from light from the retroilluminazione. However, the technology to the plasma has anch' it of the points weak people, in the first place making to work a screen to the maximum brightness meaningfully reduces the life of the panel. For this reason many owners leave the settaggi of the brightness a lot under to the maximum, that however advanced brightness of that one of the cathodic tube screen guarantees one. Finally, the display to the plasma they find themselves in difficulty in the images where there are many clear zones, the cells correspondents to those points need of much energy, going to influence the general brightness of the panel, than cove leggermente.
The technology to the base of the screen to the plasma helps to obtain high relationships of contrast. Similarly to the CRT, the screen to the plasma can obtain black nearly a every total completely extinguishing single cella/pixel, seppur then in truth this does not happen, in how much the cells always are held under load and ready to the use. This contrasts with technology LCD, where the black points, generate to you from a method of polarization of the light, are not in a position to completely blocking the coming from light from the retroilluminazione. However, the technology to the plasma has anch' it of the points weak people, in the first place making to work a screen to the maximum brightness meaningfully reduces the life of the panel. For this reason many owners leave the settaggi of the brightness a lot under to the maximum, that however advanced brightness of that one of the cathodic tube screen guarantees one. Finally, the display to the plasma they find themselves in difficulty in the images where there are many clear zones, the cells correspondents to those points need of much energy, going to influence the general brightness of the panel, than cove leggermente.
Details on the operation
The neon and gases xeno in a television set to the plasma are contained in hundred of migliaia of small cells posizionate between two panels of glass. Also of the long electrodes they come inserted between the glass panels, and behind the cells. The indirizzamento electrodes are behind the cells, along the panel of posterior glass. The transparent electrodes of the screen, that they are encircles from dielectric insulator to you and covered material of a protecting layer in magnesium oxide, are mount to you in front of the cells, along the front glass. The loaded circuitry of control the electrodes that are intercrossed to a cell, creating a potential difference them between and behind provoking to the ionization of gases and the plasma formation ; when the Ionian ones of the gas head towards the electrodes and collidono they come emitted of photons.
In a monochromatic screen, the ionizzante state can be maintained applying to a voltage of low level between all the horizontal and vertical electrodes, also when the ionization voltage comes removed. In order to cancel a cell, all the tension comes removed from the electrodes. This type of panel has an intrinsic memory and it does not use phosphorus. One small nitrogen amount comes added to neon in order to increasethe hysteresis.
In the panels to colors, the back of every cell is covered with a phosphorus. The emitted ultraviolet photons from the plasma excite these phosphorus for giving colorful light. Every cell is therefore comparable to one fluorescent lamp.
Every pixel it is made of three sottocelle separate, ognuna with phosphorus of various colors. A sottocella it has phosphorus for the red light, one for the green light and the other for the blue light. These colors join together in order to create the color total of the pixel, analogous to the Triad computers (to three colors; for technical details you see pixel, technical aspects) or to screen CRT. Varying the current impulses that slide through the various cells migliaia of times to the second, the control system can increase or diminish the intensity of every every color of sottocella in order creating billions of various combinations of green, red and blue. In this way the control system can produce the greater part of the visible colors. The display to the plasma they use same phosphorus of the CRT, that door to one reproduction of the colors extremely taken care of.
In a monochromatic screen, the ionizzante state can be maintained applying to a voltage of low level between all the horizontal and vertical electrodes, also when the ionization voltage comes removed. In order to cancel a cell, all the tension comes removed from the electrodes. This type of panel has an intrinsic memory and it does not use phosphorus. One small nitrogen amount comes added to neon in order to increasethe hysteresis.
In the panels to colors, the back of every cell is covered with a phosphorus. The emitted ultraviolet photons from the plasma excite these phosphorus for giving colorful light. Every cell is therefore comparable to one fluorescent lamp.
Every pixel it is made of three sottocelle separate, ognuna with phosphorus of various colors. A sottocella it has phosphorus for the red light, one for the green light and the other for the blue light. These colors join together in order to create the color total of the pixel, analogous to the Triad computers (to three colors; for technical details you see pixel, technical aspects) or to screen CRT. Varying the current impulses that slide through the various cells migliaia of times to the second, the control system can increase or diminish the intensity of every every color of sottocella in order creating billions of various combinations of green, red and blue. In this way the control system can produce the greater part of the visible colors. The display to the plasma they use same phosphorus of the CRT, that door to one reproduction of the colors extremely taken care of.
Characteristic generates them
The screen to the plasma is luminous (1000 lux or more for the modules), has a wide one gamut of colors and can be produced in greatest dimensions, until 262 cm (103 inches) diagonally. They have a greatest level of black "dark-room", creating "black perfect" the desirable one in order to watch films. The panel of the screen is wide only 6 centimeters, while the width total, included the part electronic that manages the screen, is inferior to the 10 centimeters. The screen to the plasma how much consumes much Watt for square meter the cathodic tubes or televisions AMLCD. The consumption is influenced from that it is being watched: luminous scenes, like, in order to make an example, a sport event, will absorb much more watt than a film with many nocturnal scenes. Nominal measures indicate approximately 400 watt for one 50"screen.
The duration of a screen to the plasma of last generation is estimated in 60 000 hours (27 years with 6 hours of uses to the day). More just, this is the esteem of half of the life of the screen, the point in which the image it is degraded to half of its brightness originates them. He is still guardabile after this point, than but it comes generally considered the end of the life works them of the screen.
The screen that they compete with includes the CRT, OLED, AMLCD, DLP, SED-tv and screen plates field emission. The main advantage of the technology for screen to the thin plasma is that large screen can be produced one much using material much. Every Siccome pixel comes ignited individually, the image is much luminous one and has a wide visible angle.
The duration of a screen to the plasma of last generation is estimated in 60 000 hours (27 years with 6 hours of uses to the day). More just, this is the esteem of half of the life of the screen, the point in which the image it is degraded to half of its brightness originates them. He is still guardabile after this point, than but it comes generally considered the end of the life works them of the screen.
The screen that they compete with includes the CRT, OLED, AMLCD, DLP, SED-tv and screen plates field emission. The main advantage of the technology for screen to the thin plasma is that large screen can be produced one much using material much. Every Siccome pixel comes ignited individually, the image is much luminous one and has a wide visible angle.
Screen to the plasma
A screen to the plasma (Plasma Display Panel - PDP) is a type of large flat screen hour commonly used for screen television (typically over to the 32 inches). Many small cells posizionate in means to two panels of glass maintain one inert noble gas mixture (neon and xeno). The gas in the cells comes electrically transformed in a plasma, which then it excites phosphorus to emit light.
Technological Evolution
# In the 2003 Kodak it has introduced the first digital camera them with screen OLED.
# In the 2004 Samsung it has commercialized cellular telephone SGH-E700, equipped of one external screen OLED to 256 colors with one resolution of 64x96 pixel.
# In the May of 2005 it has been introduced a prototype of screen OLED of 40 inches.
# Inyou open them of the 2006 University of Braunschweig has communicated one new technology that within 2 years will produce first transparent screen OLED using TFT.
# In the september of a 2006 group of investigators of the Cornell University it has created a new type of flexible OLED that acts like rising of photovoltaic cell and that therefore it generates electricity from the light.
# The Sony Japanese has announced of wanting to put in commerce for Japanese market TV based on technology OLED within 2007. XEL-1 will be the first model of television set, with 11 inches, 940 x 540 points, contrast 1.000.000:1, card of net ethernet, door HDMI, door USB. It will come produced from ST Liquid Crystal Display, Joint venture between Sony and Toyota.
# For the 2008 Sony TV OLED from 31 inches with resolution Full HD has announced one (1080 points)
# In the 2004 Samsung it has commercialized cellular telephone SGH-E700, equipped of one external screen OLED to 256 colors with one resolution of 64x96 pixel.
# In the May of 2005 it has been introduced a prototype of screen OLED of 40 inches.
# Inyou open them of the 2006 University of Braunschweig has communicated one new technology that within 2 years will produce first transparent screen OLED using TFT.
# In the september of a 2006 group of investigators of the Cornell University it has created a new type of flexible OLED that acts like rising of photovoltaic cell and that therefore it generates electricity from the light.
# The Sony Japanese has announced of wanting to put in commerce for Japanese market TV based on technology OLED within 2007. XEL-1 will be the first model of television set, with 11 inches, 940 x 540 points, contrast 1.000.000:1, card of net ethernet, door HDMI, door USB. It will come produced from ST Liquid Crystal Display, Joint venture between Sony and Toyota.
# For the 2008 Sony TV OLED from 31 inches with resolution Full HD has announced one (1080 points)
Technologies OLED
* AMOLED (Active Matrix OLED)
* PHOLED (Phosphorescent OLED)
* PLED (Polymer light-emitting diodes)
* SM-OLED (Small molecules OLED)
* SOLED (Stacked OLED)
* TOLED (Transparent Organic Light Emitting Device)
* PHOLED (Phosphorescent OLED)
* PLED (Polymer light-emitting diodes)
* SM-OLED (Small molecules OLED)
* SOLED (Stacked OLED)
* TOLED (Transparent Organic Light Emitting Device)
Limits
Technology OLED has great advantages (low tension of feeding, optimal contrast, brilliance of the colors) however still introduces of the limits. First of all the cost still elevated of the production process. In the second place screen OLED much inferior to the screen to crystals liquids and the screen to the plasma has one duration. The organic material of which they are compounds, in fact, stretches to lose the ability to emit light after little migliaia of hours of exercise.
Structure
Display a OLED is composed from several overlapping layers: on a first transparent layer, that it has protecting functions, it comes placed a transparent conductive layer that acts as from anode; subsequently they come added 3 organic layers: one for the injection of gaps, one for the electron transport , and, between of they, the three red, green and blue materials elettroluminescenti (), arranged to form an only layer composed from many elements, everyone of the which format from the three microdisplay colors to you. Finally, it comes placed a reflecting layer that acts as from cathode.
In spite of the variety of layers, the thickness total, without to consider the transparent layer, is of approximately 300 nanometers.
In spite of the variety of layers, the thickness total, without to consider the transparent layer, is of approximately 300 nanometers.
Characteristic techniques
In this case the organic material is as an example a elettroluminescente conductive polymer similar to the plastic (in this case can be spoken more correctly than POLED: polymer organic LED) or not polymer organic materials of molecular weight relatively low. An element comes mostly defined organic in how much containing one structure constituted from carbon. From here the name of led organic. Normally, the organic layers are in a position to emitting single light white woman, but with opportune drogaggi (of elettrofosforescenti compounds) are possible to render them in a position to emitting red light (drugging fluorescent made up of perilene dicarbossammide), green (cumarina) or blue (- DNA) (RGB): being these primary colors, it is possible to arrange them in order to produce all the colors of the visible phantom, in analogous way to how much happens in any display to colors: every point of an image is constituted from 3 microdisplay places side by side,that they produce red light to you, green and blue; approval from far away, every element composed from three microdisplay appears to the human eye like a single point, whose color second changes the intensity of the light of several colors emitted from the single ones microdisplay.
The Universal Display Corporation, however, has recently announced to have realized a different type of display, in which the three microdisplay of every element they are overlapped rather than places side by side to you, that it allows a remarkable increment of the resolution.
The Universal Display Corporation, however, has recently announced to have realized a different type of display, in which the three microdisplay of every element they are overlapped rather than places side by side to you, that it allows a remarkable increment of the resolution.
History
Although the property of elettroluminescenza possessed from some organic elements is known gives along time, the first types of display OLED never did not go beyond the prototype stage, in how much demanded too much high tensions of feeding (beyond 100 V) in order to turn out useful in the practical applications. Subsequently, they were developed with succeeding thin films of elettroluminescente organic material, whose small dimensions allowed the feeding through more modest tensions.
The first using models of display this technology were structurally much simple: a film of organic substance was placed between two electrodes (anode and cathode): applying a tension to the two electrodes, the passage of current in the organic layer of it caused the luminous emission.
However, this type of electrodes was not much practical one, in how much demanded, in order to work, an extreme precision in phase of production; a not perfect alignment, in fact, caused to great losses of energy and consequent inefficiency of the display.
The first display efficient ones and to low tension were introduce to you in the 1987 from Ching Tang and Steve Van Slyke; such display they made use of two organic layers: one predisposed in order to receive gaps, the other in order to receive electrons; in this way, and with successes improvements, volt was possible to construct to you display to high brightness feeds to you from low tensions (approximately 10).
The first using models of display this technology were structurally much simple: a film of organic substance was placed between two electrodes (anode and cathode): applying a tension to the two electrodes, the passage of current in the organic layer of it caused the luminous emission.
However, this type of electrodes was not much practical one, in how much demanded, in order to work, an extreme precision in phase of production; a not perfect alignment, in fact, caused to great losses of energy and consequent inefficiency of the display.
The first display efficient ones and to low tension were introduce to you in the 1987 from Ching Tang and Steve Van Slyke; such display they made use of two organic layers: one predisposed in order to receive gaps, the other in order to receive electrons; in this way, and with successes improvements, volt was possible to construct to you display to high brightness feeds to you from low tensions (approximately 10).
OLED
OLED isthe acronym of Orrganic Light andmitting Diode that is organic diode valve to emission of light.
Technology that allows to realize display to colors with the ability to emit own light: to difference of display to crystals the liquids, display the OLED do not demand members added to you for being illuminate (display to crystals the liquids to you come illuminate to you from a source of external light), but they produce own light; this allows to realize display much thinner and quite collapsible and arrotolabili, and that minors demand energy amount in order to work.
Because of the monopolar nature of the layers of organic material, display the OLED lead single current in one direction, behaving themselves therefore in analogous way to a diode valve; here the O-LED name, for similitudine with the LED.
Technology that allows to realize display to colors with the ability to emit own light: to difference of display to crystals the liquids, display the OLED do not demand members added to you for being illuminate (display to crystals the liquids to you come illuminate to you from a source of external light), but they produce own light; this allows to realize display much thinner and quite collapsible and arrotolabili, and that minors demand energy amount in order to work.
Because of the monopolar nature of the layers of organic material, display the OLED lead single current in one direction, behaving themselves therefore in analogous way to a diode valve; here the O-LED name, for similitudine with the LED.
Applications
The crystals liquids find wide use in the screen to crystals liquids, that they take advantage of the optical property of determined liquid-crystalline molecules. These molecules in presence of an electric field are aligned with it, altering the polarization of the light in a determined sense. Taking advantage of this ability it is possible to filter the light that it passes within I affixed panels to you polarizes to you.
An other application, that it takes advantage of the property of crystals colesterici liquids, finds in some thermometers for the measure of the corporea temperature or the circuits electrical workers.
An other application, that it takes advantage of the property of crystals colesterici liquids, finds in some thermometers for the measure of the corporea temperature or the circuits electrical workers.
Mesofasi liotropiche
A mesofase liotropica it is generated from mesogeni that disciolti in dissolvent appropriating, and in it determines concentration intervals to you, become a member of in liquid-crystalline structures.
Often the mesogeni liotropici they are anfifiliche molecules (that is they contain is groups works them idrofobici that idrofilici). To varying of the concentration of the dissolvent (water in this case) the idrofiliche or idrofobiche property can vary, modifying the way in which molecules they become a member of between of they and in connection with molecules of the dissolvent.
The degree of order of aggregation of these molecules increases increasing of the concentration, and exists numerous possibilities of micelle aggregation, between which as an example:
* Spherical
* Colonnare
* Cubical
* Lamellare
Numerous tensioatti to you they show this type of behavior and they are organized in micelles when disciolti in water. The operation of many soaps is based on this ability to organize itself in spheroidal micelles that inglobano the fat person rimuovendolo from the dealt surface.
Also in Biology they are met mesogeni liotropici: as an example numerous substances been involved in the mechanism of biological membranes, the proteins that constitute the burlap of the spider, some virus, the phospholipids and the same DNA.
Often the mesogeni liotropici they are anfifiliche molecules (that is they contain is groups works them idrofobici that idrofilici). To varying of the concentration of the dissolvent (water in this case) the idrofiliche or idrofobiche property can vary, modifying the way in which molecules they become a member of between of they and in connection with molecules of the dissolvent.
The degree of order of aggregation of these molecules increases increasing of the concentration, and exists numerous possibilities of micelle aggregation, between which as an example:
* Spherical
* Colonnare
* Cubical
* Lamellare
Numerous tensioatti to you they show this type of behavior and they are organized in micelles when disciolti in water. The operation of many soaps is based on this ability to organize itself in spheroidal micelles that inglobano the fat person rimuovendolo from the dealt surface.
Also in Biology they are met mesogeni liotropici: as an example numerous substances been involved in the mechanism of biological membranes, the proteins that constitute the burlap of the spider, some virus, the phospholipids and the same DNA.
Classification
The compounds that form mesofasi (mesogeni) when disciolti in an opportune dissolvent in a sure interval of concentration, sayings come crystals liotropici liquids. Those in a position to generating mesofasi to varying of the temperature come call to you thermotropic generally and are equip of one molecular structure to you to disc shape (crystals discotici liquids), or to shape of stick (calamitici).
A same compound, in the distance between the crystalline state and that liquid isotropo, can pass through several mesofasi contraddistinte from a degree of decreasing order.
To the class of crystals liotropici liquids numerous substances belong, some di.le which of great biological interest, than they become a member of in mesofasi when they come disciolte in an opportune dissolvent. It is possible to observe different liotropiche mesofasi to varying of the concentration, and exists a critical value under which the solution is isotropa.
A same compound, in the distance between the crystalline state and that liquid isotropo, can pass through several mesofasi contraddistinte from a degree of decreasing order.
To the class of crystals liotropici liquids numerous substances belong, some di.le which of great biological interest, than they become a member of in mesofasi when they come disciolte in an opportune dissolvent. It is possible to observe different liotropiche mesofasi to varying of the concentration, and exists a critical value under which the solution is isotropa.
Property
The crystals liquids can be defined like highly anisotropic fluid that exist between the crystalline solid phase and that liquid isotropa: this is that that has been defined the "fourth state of the matter".
The existence of these mesofasi is due to a sure organization that the molecules can assume passing from the former crystalline disposition of the solid state to the accidental disposition of the liquid state.
Numerous crystals liquids can be observe to you based on their optical birifrangenza to the microscope with polarizzatori filters intercross to you.
To the typical property of the solid state (optical anisotrophy and electrical worker) and of the liquid state (fluidity and molecular mobility) join to peculiar characteristics of crystals liquids: as an example the possibility to vary of the degree of order for means of magnetic fields and electrical workers, or the faculty that they have to change color varying of the temperature.
This has made of crystals composed liquids a class of that today they are widely used for the construction of objects of daily use.
The existence of these mesofasi is due to a sure organization that the molecules can assume passing from the former crystalline disposition of the solid state to the accidental disposition of the liquid state.
Numerous crystals liquids can be observe to you based on their optical birifrangenza to the microscope with polarizzatori filters intercross to you.
To the typical property of the solid state (optical anisotrophy and electrical worker) and of the liquid state (fluidity and molecular mobility) join to peculiar characteristics of crystals liquids: as an example the possibility to vary of the degree of order for means of magnetic fields and electrical workers, or the faculty that they have to change color varying of the temperature.
This has made of crystals composed liquids a class of that today they are widely used for the construction of objects of daily use.
Crystals liquids
The crystals liquids, or in order better to say "the possessed liquid-crystalline property from some organic compounds", were discoveries in the 1888 from the Austrian botanist Friedrich Reinitzer.
Reinitzer noticed that heating of the colesterile benzoate this at first it became opaque, in order then to schiarirsi to the progressive one to raise itself of the temperature. Once cooled, the liquid became bluastro and then it crystallized.
In practical such substances directly from the solid state to that liquid, but in particular conditions they are in a position to organizing itself in makes (mesofasiintermediate) that they introduce characteristics is of the crystalline solid state that of that liquid. This dualismo justifies the term with which these compounds are indicated: crystals liquids.
Reinitzer noticed that heating of the colesterile benzoate this at first it became opaque, in order then to schiarirsi to the progressive one to raise itself of the temperature. Once cooled, the liquid became bluastro and then it crystallized.
In practical such substances directly from the solid state to that liquid, but in particular conditions they are in a position to organizing itself in makes (mesofasiintermediate) that they introduce characteristics is of the crystalline solid state that of that liquid. This dualismo justifies the term with which these compounds are indicated: crystals liquids.
Families of panels TFT
The main families of panels to crystals liquids of type TFT are:
* TN - Twisted nematic
* Vertical GOES - alignment
o MVA
+ P-MVA/S-MVA
+ A-MVA
o PVA
+ S-PVA
* IPS - In-plane switching
o S-IPS
o AS-IPS/ES-IPS
o IPS-for
* ASV
* TN - Twisted nematic
* Vertical GOES - alignment
o MVA
+ P-MVA/S-MVA
+ A-MVA
o PVA
+ S-PVA
* IPS - In-plane switching
o S-IPS
o AS-IPS/ES-IPS
o IPS-for
* ASV
Defective state.
Beyond to the aforesaid prettamente technical parameters, it is opportune to point out to the problem of the pixel burns to you, that is impossible to control because of one defective state to the film of typical transistor of matrices TFT. It is important to observe that, contrarily to how much it could be imagined, it is not worth always the equation "pixel ignited = pixel white man". In fact in some technical families of panels the ignited state of the pixel corresponds to the white man, while in others it corresponds that is to the black one (nero=acceso, bianco=spento). It achieves some that an breakdown will be able to more probably turn out in pixel (or a subpixel R, G or B) perennially ignited or perennially extinguished to second of the type of installed panel CL.
Irregolarity of the scale of the grays.
As famous in system RGB adopted from PC, dvd, dvb, high definition, etc the gray can assume 256 equal levels to the possible combinations with 8 bit. A value 0 corresponds to the black one while 256 correspond to the white man. He is intuitable therefore that, if a screen has the maximum brightness - to example of 400 cd/mq, such level of brightness will correspond to the white man, that is to a value of 256 on the scale of the grays. The much less explicit one is the fact that to the value of 128 (halves scale) does not correspond the value of 200 cd/mq: the real value of brightness is generally much more low. In other words, the scale of grays is not at all linear, but it follows a esponenziale course with expansions and jams: as already said - to example black (value 0) it is not completely buio, and moreover to growing of values RGB the course of the brightness grows less in a marked manner than how much us it could be waited for, in order then to increase remarkablly towards the bottom of the scale. It is therefore possible that some near values of gray are not in practical distinguibili between they, species to the ends of the scale (low and high lights). It also goes noticed that the variation of brightness and contrast in kind is not to delineate with the observation angle, for which this topic is connected with how much before said on purpose of the visual angle. Some tipologie of panels (* GO quite) introduce a scale of the grays better (that is the best one rendered and distinction of the various tonalities of gray, in particular on the low lights) if it watches to you in leggermente angled position rather than centrally.
Visual angle of in connection with brightness and contrast
The angle of visual is an other important parameter: also in this case various modalities of measurement exist. The pubblicizzati angles of visual refer in kind to the maximum angle under which the screen can be watched maintaining one "acceptable" brightness and a contrast: the degree of "acceptability" can be liberations established from the producers, for which it is possible that the data supplied from various producers have mean to you various. As an example, the limit is in kind characterized from a 10:1 contrast, for which a sure angle of visual is obtained; if it is considered instead 5:1, the angle of visual will increase, also referring to same identical panel CL with the same identical characteristics.
Brightness and chromatic yield of the retroilluminazione
"television" screen LCD is today characterizes you from one brightness much elevating, of the order of the hundreds of candles to the metroquadro (cd/mq): this elevated brightness renders them also with one strongly light very visible acclimatizes them but it can even turn out annoying for the vision in an atmosphere buio or seeds-buio. The reason for which the constructors they adopt strong retroilluminazioni therefore can be explained with the effect that such strongly brightness has on the "dynamic contrast". As already said it it is, to parity of panel CL, as well as more elevated how much greater one it is the relationship between the white man, measured with the maximum retroilluminazione, and the black one, measured with the minimal retroilluminazione. It is comprised well that the increase of the maximum brightness is the simpler way for pubblicizzare values of dynamic contrast a lot elevates to you. Moreover, one strongly brightness stretches to increase to the persistence of the vision on the hairnet increasing the perceived time of answer and effect wake.
Speech to part deserves the chromatic yield of the panel, that is the ability to reproduce one immense range of colors. Premised that no kind of screen of some type is in a position to reproducing all the percepibili colors from the human eye, the chromatic yield depends in good part from the retroilluminazione, and in the fattispecie from the monocromaticità of colors RGB (red green and blue) of the subpixel. With them it puts into effect them lamps of retroilluminazione to discharge are obtained turns out to you discreet but the use of led allows to ulteriorly improve the level of monocromaticità of the three fundamental colors, with the consequent effect to increase the surface of the gamut, that is of the triangle having for you concern three colors to us RGB and that it represents the riproducibili shadings of color from the screen. However, it is not said that sources video (comprised the high definition, HD DVD and Blu-ray) can indeed take advantage of effectively these gamut more extensive, being however codified to 8 bit for channel.
Speech to part deserves the chromatic yield of the panel, that is the ability to reproduce one immense range of colors. Premised that no kind of screen of some type is in a position to reproducing all the percepibili colors from the human eye, the chromatic yield depends in good part from the retroilluminazione, and in the fattispecie from the monocromaticità of colors RGB (red green and blue) of the subpixel. With them it puts into effect them lamps of retroilluminazione to discharge are obtained turns out to you discreet but the use of led allows to ulteriorly improve the level of monocromaticità of the three fundamental colors, with the consequent effect to increase the surface of the gamut, that is of the triangle having for you concern three colors to us RGB and that it represents the riproducibili shadings of color from the screen. However, it is not said that sources video (comprised the high definition, HD DVD and Blu-ray) can indeed take advantage of effectively these gamut more extensive, being however codified to 8 bit for channel.
Time of answer of crystals liquids for transitions white man-black or gray-gray, effect wake and techniques of improvement of "the perceived" time
As famous the mechanism of operation of a screen to CL is based on the fact that, it orients to you in opportune way, the CL can concur or less the passage of the coming from light from the retroilluminazione of the panel; the time of answer total is in kind defined like the time necessary to the CL in order to pass from one be "all closed" (black) to one "all open" (white man), in order then to return to the "all closed one". However some producers measure alone the bianco>nero passage (or viceversa) to which they achieve therefore lower values of time. Moreover, it is not said that the bianco>nero passage has the same duration of the passage nero>bianco. In truth, this often boasted value from the producers is not indeed meaningful, in how much it is rarest that in filmato steps from the white man to the black one (or viceversa): very more frequent it is that steps from a shading of gray to an other and the times for the transitions gray-gray (G2G) are generally longer than that white man-black.Today sovravoltaggio) of panels CL is in correct part this slowness on the gray-gray by means of techniques of "overdrive" (, to the cost but of an increase of the noise of the images and/or sometimes of a reduction of riproducibili colors (6 bit rather than 8, simulates to you then through techniques of dithering).
The so-called "effect wake" that often comes attributed to panels LCD is in truth by now only in riferibile part to the time of answer of the CL: in part it is in fact to charge itself to the persistence of the vision on the hairnet, that is depends on the physiology of the human eye[necessary citation]. In fact, the perception of the effect wake also is tied to the fact that panels LCD maintain the image between frame and an other and are retroilluminati in continuous, with the exception of a traditional cathode-ray tube in which the image it is "reconstructed" to the frequency of refresh of screen (50 or 100 Hz the TV; from 60 until 120 Hz a monitor for PC). In other words, while the phosphorus of a CRT alone stretch "to extinguish themselves" endured after the passage of the electron paint-brush , in a LCD-TFT (like in all the screen to active matrix, put molding on and OLED) the pixel conserve the brightness "until new order", that is until the successive photogram of the filmato one. This is a great advantage for a screen PC (the image is stable and not sfarfalla), but it becomes a problem with images (TV, film in motion): every photogram turns out in fact in part overlapped to the previous one to cause is of the slowness of the CL to change be, is to the persistence of the vision on the hairnet. Of fact also with a theorist LCD with instantaneous time of answer a sure effect would be always present wake[necessary citation]. The solutions currently on the market are substantially three, commercially often joined (also improperly) from diciture type 100Hz: paradoxicalally such several solutions always do not have to that to make with 100Hz of the CRT and indeed the someone they try to imitate the operation of a classic CRT to 50Hz. Such effect comes obtained by means of the intercalamento of completely black pictures, interpolated intermediate pictures "calculate to you" from the electronics of the screen or by means of the short sequenziali extinctions of the lamps of retroilluminazione (realizing one risen of "luminous scansion" of the screen); for obvious reasons the constructors are restii - in some cases to supply precise indications on the precise operation of these technical new. Some of these solutions could determine an increase of the perception of sfarfallamento of screen LCD.
The so-called "effect wake" that often comes attributed to panels LCD is in truth by now only in riferibile part to the time of answer of the CL: in part it is in fact to charge itself to the persistence of the vision on the hairnet, that is depends on the physiology of the human eye[necessary citation]. In fact, the perception of the effect wake also is tied to the fact that panels LCD maintain the image between frame and an other and are retroilluminati in continuous, with the exception of a traditional cathode-ray tube in which the image it is "reconstructed" to the frequency of refresh of screen (50 or 100 Hz the TV; from 60 until 120 Hz a monitor for PC). In other words, while the phosphorus of a CRT alone stretch "to extinguish themselves" endured after the passage of the electron paint-brush , in a LCD-TFT (like in all the screen to active matrix, put molding on and OLED) the pixel conserve the brightness "until new order", that is until the successive photogram of the filmato one. This is a great advantage for a screen PC (the image is stable and not sfarfalla), but it becomes a problem with images (TV, film in motion): every photogram turns out in fact in part overlapped to the previous one to cause is of the slowness of the CL to change be, is to the persistence of the vision on the hairnet. Of fact also with a theorist LCD with instantaneous time of answer a sure effect would be always present wake[necessary citation]. The solutions currently on the market are substantially three, commercially often joined (also improperly) from diciture type 100Hz: paradoxicalally such several solutions always do not have to that to make with 100Hz of the CRT and indeed the someone they try to imitate the operation of a classic CRT to 50Hz. Such effect comes obtained by means of the intercalamento of completely black pictures, interpolated intermediate pictures "calculate to you" from the electronics of the screen or by means of the short sequenziali extinctions of the lamps of retroilluminazione (realizing one risen of "luminous scansion" of the screen); for obvious reasons the constructors are restii - in some cases to supply precise indications on the precise operation of these technical new. Some of these solutions could determine an increase of the perception of sfarfallamento of screen LCD.
Native contrast and dynamic contrast, fluorescent retroilluminazione or to led
The relationship between the brightness of the white man and the brightness of the black one is defined contrast. Draft therefore of a parameter - native of the panel employee from the ability to crystals liquids to stop the coming from light from the retroilluminazione. The so-called "dynamic contrast" viceversa does not only depend on crystals liquids (of continuation CL), but also from the retroilluminazione: it is in fact the relationship between the white man, measured with the retroilluminazione to the maximum, and the black one, measured with the lessened retroilluminazione. The values of dynamic contrast are therefore much formally higher than that native one of the panels, medium of a relationship of 1 to 5. Today the best panels boast contrasts born you of the same order of magnitude of those dynamic ones of the panels more given to you; in kind comunuque the dynamic contrasts are of the order of magnitude of the various ones migliaia:1, while those NATO to you oscillate meaningfully around the 1000:1 (and in some recent cases also beyond). An image that it has is clear parts that dark a panel puts however in difficulty that boasts high dynamic contrasts in how much the brightness of the retroilluminazione is only, for which the real contrast it will be that native of the CL and not that dynamic one. Since the retroilluminazioni to LED (therefore "more aliquot") allow to separately manage the several parts of the image, these would have to allow a partial improvement of the situation, igniting and extinguishing single groups of LED. Strong contrasts are however necessary only for the use in full light of the screen; observed và in fact that the really perceived contrast depends also on the lighting system of the atmosphere and the superficial finish of the screen (lucido/riflettente or opaco/diffondente). Since in any case the screen is not a black body and reflects a part of the light that hits it, is intuitivo that the luminance of the black one comes altered if the screen is hit from one strongly ambient light. Viceversa, as an example for the vision of a film in a dark atmosphere (the typical stay the evening), contrasts elevates to you is in kind in how much annoying the parts of more luminous image has a dazzling effect, reducing the perception of the details in the darker parts and increasing to the perceived effect wake.
Parameters of characterization of a panel LCD
The main parameters that characterize a recent screen LCD to active matrix (TFT) for TV or PC are contrast, brightness (or more properly luminance), linearity of the grays, angle of visual, time of answer and chromatic yield. Moreover for the TV, also not making part of the true panel and just, also the electronics of scalatura of the image are determining for the quality video.
Screen assets and liabilities to you
Screen LCD with a modest number of segments, like those used in the calculators or the digital clocks them, is supplies of a contact electrical worker for every segment. It marks them electrical worker in order to control every segment is generated from an external circuit. This type of structure becomes improponibile as the number of segments increases.
The screen of medium dimensions, like those of the electronic agendas, structure to passive matrix has one. This type of structure has a group of contacts for every line and column of the screen, instead that one for every pixel. The disadvantage is that a pixel can be only controlled to the time, the others pixel must newly remember their state until the control loop not dedication to they. The result is a reduced contrast and one sure difficulty to visualize the images in express well movement. The problem clearly goes getting worse as the number of pixel increases.
For the screen to high resolution, like the monitor for computer, a system to active matrix is used. In this case screen LCD contains one thin film of transistor (Thin Film Transistor - TFT). This device memorizza the state electrical worker of every pixel of the screen while the others pixel come dawn to you. This method allows to obtain more luminous and clear images much regarding the traditional LCD.
The average life of screen LCD is attested to the day around to the 50,000 hours today. This data, united to the remarkable and constant reduction of their price, renders this technology one valid alternative to the cathodic tube screen.
The screen of medium dimensions, like those of the electronic agendas, structure to passive matrix has one. This type of structure has a group of contacts for every line and column of the screen, instead that one for every pixel. The disadvantage is that a pixel can be only controlled to the time, the others pixel must newly remember their state until the control loop not dedication to they. The result is a reduced contrast and one sure difficulty to visualize the images in express well movement. The problem clearly goes getting worse as the number of pixel increases.
For the screen to high resolution, like the monitor for computer, a system to active matrix is used. In this case screen LCD contains one thin film of transistor (Thin Film Transistor - TFT). This device memorizza the state electrical worker of every pixel of the screen while the others pixel come dawn to you. This method allows to obtain more luminous and clear images much regarding the traditional LCD.
The average life of screen LCD is attested to the day around to the 50,000 hours today. This data, united to the remarkable and constant reduction of their price, renders this technology one valid alternative to the cathodic tube screen.
Color screen
The crystals present liquids in ruotano screen LCD all the wave shapes in the same way, but some sagacities allow to differentiate the behavior of the single cells and to produce color screen.
In a every screen LCD to colors pixel it comes divided in three sections (subpixel), one with a red filter, one with a green filter and one with a blue filter. Altogether the pixel it can therefore appear simply of an arbitrary color varying every the relative brightness of single section.
In a every screen LCD to colors pixel it comes divided in three sections (subpixel), one with a red filter, one with a green filter and one with a blue filter. Altogether the pixel it can therefore appear simply of an arbitrary color varying every the relative brightness of single section.
Screen Transmissive, Reflective and Transflexive
Screen LCD I can be used in two transmissive and reflective called modalities. The transmissive screen of type is illuminates and comes seen to you on one side from the other. In practical a light it comes posizionata on the back of the screen and the crystals liquids act from filter making to only pass the wished chromatic member. In this way they obtain screen much luminous, of other song, but the light source often consumes more energy than that demand from the screen in himself. This screen has a good leggibilità in conditions of insufficient light acclimatizes them, while they strongly become little visible in conditions lighting system, turning out adapted for the use in inner.
Reflective screen LCD of type uses the present light in the atmosphere that comes reflected from one mirror place behind the screen. This screen more low has a contrast regarding the transmissive LCD, in fact the light is forced to pass two times through the filter. The main advantage of this type of screen is that the absence of a source of artificial light maintains to the energetic consumptions many bottoms. A small screen LCD consumes little therefore that simple photovoltaic cell can be fed from one. This screen lighting system has a good leggibilità in conditions strongly acclimatizes them, while they turn out leggibili less and less to diminishing of the external lighting system.
The Transflexive screen tries to join the better characteristics of the Transmissive and the Reflective. They have a seed-mirror place behind the display, in a position to reflecting the frontal light (like the reflective), but to make to pass to the coming from light from an illuminator place in the posterior part (like the trasmissive). This type of display is gone diffusing quickly, above all in the apparatuses furnish (cellular telephones and palmari computers), for its good leggibilità in all the light conditions.
Reflective screen LCD of type uses the present light in the atmosphere that comes reflected from one mirror place behind the screen. This screen more low has a contrast regarding the transmissive LCD, in fact the light is forced to pass two times through the filter. The main advantage of this type of screen is that the absence of a source of artificial light maintains to the energetic consumptions many bottoms. A small screen LCD consumes little therefore that simple photovoltaic cell can be fed from one. This screen lighting system has a good leggibilità in conditions strongly acclimatizes them, while they turn out leggibili less and less to diminishing of the external lighting system.
The Transflexive screen tries to join the better characteristics of the Transmissive and the Reflective. They have a seed-mirror place behind the display, in a position to reflecting the frontal light (like the reflective), but to make to pass to the coming from light from an illuminator place in the posterior part (like the trasmissive). This type of display is gone diffusing quickly, above all in the apparatuses furnish (cellular telephones and palmari computers), for its good leggibilità in all the light conditions.
Screen to crystals liquids
A screen to crystals liquids, or LCD (Liquid Crystal Display), is one thin and light screen without no mobile part. It is composed from a liquid caught in numerous cells. Every cell is supply of contacts electrical workers with which to be able to apply to an electric field to the liquid that contains. Polarizzatori the same cells are contained to the inside of two screen along perpendicular aces between they. The crystals liquids twist of 90° the polarization of the light that arrives from one of the polarizzatori, allowing them to pass through the other.
Before that the electric field is applied, the light can pass through the entire structure, and, to part one small part of light absorbed from the polarizzatori, the apparatus turns out transparent. When the electric field comes activated molecules of the liquid aligns in parallel with the electric field, limiting the spin of the entering light. If the crystals are completely align to you with the field, the light that passes to you through is polarized perpendicular to according to polarizzatore, and therefore it is blocked of all. The pixel it will appear not illuminated. Controlling the torsion of crystals liquids in every pixel, how much light can be controlled to make to pass, corresponding illuminating the pixel.
The unit of measure of the dimensions of the screen is inch (2,54 cm), and is the distance measured in diagonal between two opposite angles of the screen; largest currently available, adapted to the vision of the TV to high definition, arrive to 65 inches with one resolution of 1920 X 1080 pixel. In the month of August 2007, Samsung constructor has introduced two new LCD of great dimensions (the greater one of 70 inches) which adopting the technique of retroilluminazione to LED, door the value of dynamic contrast to a 500.000:1 relationship.
One of the main characteristics of the panels to crystals liquids (made saves the retroilluminazione) is the low consumption of power electrical worker, than it renders them particularly indicates for applications in equipment fed from batteries electrical workers to you. Particular applications, as an example in the TV, involve instead consumptions total electrical workers rather elevate (a TV to you 32 "have powers of approximately 120-180W).
Before that the electric field is applied, the light can pass through the entire structure, and, to part one small part of light absorbed from the polarizzatori, the apparatus turns out transparent. When the electric field comes activated molecules of the liquid aligns in parallel with the electric field, limiting the spin of the entering light. If the crystals are completely align to you with the field, the light that passes to you through is polarized perpendicular to according to polarizzatore, and therefore it is blocked of all. The pixel it will appear not illuminated. Controlling the torsion of crystals liquids in every pixel, how much light can be controlled to make to pass, corresponding illuminating the pixel.
The unit of measure of the dimensions of the screen is inch (2,54 cm), and is the distance measured in diagonal between two opposite angles of the screen; largest currently available, adapted to the vision of the TV to high definition, arrive to 65 inches with one resolution of 1920 X 1080 pixel. In the month of August 2007, Samsung constructor has introduced two new LCD of great dimensions (the greater one of 70 inches) which adopting the technique of retroilluminazione to LED, door the value of dynamic contrast to a 500.000:1 relationship.
One of the main characteristics of the panels to crystals liquids (made saves the retroilluminazione) is the low consumption of power electrical worker, than it renders them particularly indicates for applications in equipment fed from batteries electrical workers to you. Particular applications, as an example in the TV, involve instead consumptions total electrical workers rather elevate (a TV to you 32 "have powers of approximately 120-180W).
Digital Light Processing
The Digital Light Processing (or DLP inthe English acronym) is a technology applied to the devices you that they visualize images, like the videoproiettori of last generation. It takes advantage of an optical semiconductor in order to manipulate the digital light them. Microchip DMD (Digital Micromirror Device) is covered of million mirrors that independently move one from the other and that they are in a position to representing R-al.meglio every pixel of the image. The result is one quality of advanced vision to technology LCD and a high relationship of contrast.
To the CES 2008 Nec introduces its first model of screen based on DLP: NEC CRVD-42DWX+ with one resolution of 2880x900 pixel, a time and contrast 10000:1 of answer of 0,2 milliseconds.
To the CES 2008 Nec introduces its first model of screen based on DLP: NEC CRVD-42DWX+ with one resolution of 2880x900 pixel, a time and contrast 10000:1 of answer of 0,2 milliseconds.
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