What kind of LCD screen are there?
Author:Liu Chunyan Time:2021-08-05 08:03 Browse(579)
What kind of Regent screen? The bright screen is called by the manufacturer. If you press the screen by hand, it will change color, which is called soft screen / no response, which is called hard screen. Description of various LCD screen types (TFT, TFD, ufb, STN, DSTN, OLED, GF, CG, etc.)
What kind of Regent screen? Bright screen is called by manufacturers. Pressing the screen by hand will change color, which is called soft screen / no response, which is called hard screen. Description of various types of LCD screen (TFT, TFD, ufb, STN, DSTN, OLED, GF, CG, etc.) at present, color screen mobile phones have been popular, but the screen parameters of color screen are also uneven. There are many kinds of screens, such as TFT, TFD, ufb, STN, etc, Although most of the old bird players are very clear about the difference, but for some birds just into the forest, there are still some unclear, look at the following introduction, I hope to help you! The color screens of mobile phones are different due to different LCD quality and R & D technology.
generally speaking, the more colors they can display, the more complex images they can display.
the levels of images are also richer.

What kind of LCD screen are there?

at present, the number of colors that can be displayed by mobile phones on the market has reached 260000.
the technical indicators of mobile phone screens also include screen resolution.
we put the number of LCD cells (units) into the screen Dot) divided by the screen area is the screen resolution, This index is the biggest factor that determines the quality of the picture.
therefore, when purchasing a color screen mobile phone, we should not only pay attention to the color depth that the screen can display.
screen resolution is also a very important index.
TFT thin film transistor is one of the active matrix LCD am-lcd.
TFT sets a special light tube on the back of the LCD, This is the origin of the so-called active matrix TFT, which can greatly improve the response time. Generally, the response time of TFT is relatively fast,About 80 ms and 200 ms for STN, If we want to improve it, there will be flicker.
and because TFT is an active matrix LCD, it can make the arrangement of liquid crystal have memory.
it will not return to its original state immediately after the current disappears.
TFT also improves the flicker (water ripple) - blur phenomenon of STN, and effectively improves the ability of playing dynamic pictures.
compared with STN.
TFT has excellent color saturation, color stability and color stability However, the disadvantages are power consumption and high cost.
TFD screen TFD is the abbreviation of thinfilmdiode.
due to the high power consumption and high cost of TFT.
this undoubtedly increases the usability and mobile phone cost, Therefore, TFD technology has been developed by Seiko Epson, a giant of mobile screen, and is specially used in mobile screen.
it is a compromise between TFT and STN.
it has better brightness and color saturation than STN, but it also saves more power than TFT.
the characteristics of TFD are "high image quality, ultra-low power consumption, miniaturization, low power consumption, low power consumption, high power consumption, low power consumption, low power consumption, low power consumption, high power consumption, low power consumption, low power consumption, low power consumption, low power consumption, low The display principle of TFD is that each pixel on the LCD is equipped with a separate diode as the control source.
because of this separate control design, each pixel will not affect each other, As a result, it can display dynamic images without residual shadow and bright colors.
like TFT, TFD is also an active matrix driver.
the initially developed TFD can only display 4096 colors.
however, if image processing technology is adopted, it can display images of 260000 colors.
however, compared with TFT, it is still inferior in color display.
compared with TFT, TFD can only display 4096 colorsAt present, the more common mobile phones using TFD include necn8, Samsung sch-x319 and lgcu8280 ufb screen with 260000 colors. Ufb is the abbreviation of ultrafine (bright).
March 2002.
as the first LCD market share in the world, Samsung Electronics released a ufblcd for mobile phones, Ufb-lcd is characterized by ultra-thin and high brightness.
in the design, ufb-lcd also adopts a special grating design.
it can reduce the pixel spacing to obtain better image quality.
generally, ufb-lcd can display 65536 colors.
it can reach 128 colors × The resolution of ufblcd is 160 pixels. At the same time, the contrast of ufblcd is twice that of STN LCD. When the color is 65536, the brightness of ufblcd is the same as that of TFT, and the power consumption is less than that of TFT, and the price of ufblcd is similar to that of STN, It can be said that it combines the advantages of these two existing products.
ufb LCD makes the multi-function mobile phones with large color LCD closer and closer to us.
now the mobile phones using ufblcd are mainly Samsung mobile phones, such as shgt208, t508, etc.
generally speaking, ufb still has a certain gap compared with TFT, And the power consumption is not satisfactory.
STN screen STN is the abbreviation of supertwisted nematic, which is the LCD we contact most, because the screens of gray-scale mobile phones we used in the past are all STN's.
compared with the previous several LCDs.
STN LCD belongs to passive matrix LCD device, It has the advantage of low power consumption and power saving.
the display principle of color STN is to add a color filter to the traditional monochrome STN liquid crystal displayEach pixel in the monochrome display matrix is divided into three sub pixels, and red, green and blue primary colors are displayed through color filters, Different from TFT,
STN is a passive passive LCD, which can display up to 65536 colors.
apart from gray-scale STN, STN is mainly divided into CSTN and DSTN.
CSTN, that is, colorstn generally adopts transmission lighting mode, and the transmission screen uses external light source lighting.
it is called backlight, The lighting source should be installed behind the LCD.
the transmission LCD has good display effect under normal light and dark light lines.
but it is difficult to distinguish the display content outdoors, especially in sunlight, and the backlight needs power supply to produce lighting light, In the past, it was mainly used in some notebook computers.
it is also a kind of passive display technology.
using two display layers, this display technology solves the drift problem in traditional STN display, and because DSTN also uses double scanning technology, it can reduce the power consumption, Therefore, the display effect is greatly improved compared with STN.
because DSTN can scan the upper and lower screens at the same time, a bright line may appear in the center of the display screen in use.
at present, DSTN LCD has Nokia's 72106610 and so on OLED organic light emitting display (OLED organic light emitting display) is a new type of Mobile LCD, which is known as "dream display"OLED display technology is different from traditional LCD display.
it does not need backlight, and uses very thin organic material coating and glass substrate. When current passes through, these organic materials will emit light.
moreover, OLED display screen can be made lighter and thinner.
the viewing angle is larger, At present, low molecular OLED technology is mastered by Japan, while the so-called OEL of polymer pledlg mobile phone is this system, and the technology and patent are mastered by CDT, a British technology company, However, although OLED with better technology will replace TFT and other LCDs in the future, organic light-emitting display technology still has some problems, such as short service life, low cost and low cost At present, OLED is mainly used by Samsung, such as the newly launched schx339, which uses 256 color OLED, while OEL is mainly used by LG, which has been seen on cu81808280.
other types of LCD besides the above categories, we can also see other LCD on some mobile phones, such as Japanese sharp GF screen and CG continuous crystalline silicon LCD.
two kinds of LCD are available Compared with LCD, it belongs to completely different types. The improvement of GF for STN can improve the brightness of LCD, while CG is a high-precision high-quality LCD, which can reach QVGA (240) × At present, the main manufacturers of LCD panel are sharp, Samsung, LG Philips, Youda optoelectronics, Qimei electronics, BOE, etc.
The wide view technology of LCD TV panel is divided into TN + film (soft screen) camp, IPS (hard screen) camp and VA (soft screen) camp.
they have their own advantages.
let's take a closer look now.
1 TN + film technology is still based on the traditional TN mode liquid crystal.
only a film sticking process is added in the manufacturing process.
the biggest feature of TN + film wide-angle technology is its low price.
technology access threshold is low, and it is widely used.
in general.
TN panel is a product with obvious advantages and disadvantages, low price and less output gray class, Because of the fast deflection speed of liquid crystal molecules, the response time is easy to be improved, so that the response time can meet the requirements of the game is its advantage, Poor viewing angle and unreal color performance are the obvious disadvantages.
therefore, the improved TN + film (compensation film) is widely used to make up for the deficiency of viewing angle of TN panel in the current market.
at the same time, the use of color jitter technology also makes the TN panel which can only display 260000 colors obtain 16.2M display capacity.
in this paper, the color jitter technology of TN panel is introduced
2. The biggest selling point of IPS (in plane switching mode) wide view technology (hard screen) is that its two poles are on the same plane.
unlike other liquid crystal modes, the electrodes are arranged on the upper and lower sides in a three-dimensional manner.
because the electrodes are on the same plane.
regardless of the state, the liquid crystal molecules are always parallel to the screen, which will reduce the opening rate and light transmittance, Therefore, IPS application in LCD TV will need more backlights.
the black color restored by IPS is slightly worse than that of PVA.
this paper introduces the application of IPS in LCD TVTherefore, we need to rely on the compensation of optical film to achieve better black; Another characteristic of IPS mode LCD is that it can see the gray scale reversal phenomenon similar to TN mode when it is observed at an angle of 45 degrees, which can be used as a sign to distinguish IPS.
IPS also has the disadvantages of slow response time and difficult to improve contrast.
(S-IPS and as-ips are improved iPS technology).
3 At present, VA panels are widely used in high-end LCD applications.
16.7M color number and large viewing angle are the capital for this kind of panels to locate high-end. At the same time, VA panels can be divided into MVA panels and PVA panels.
1 MVA (multi domain vertical alignment) mode liquid crystal display.
the long axis of liquid crystal molecules is not parallel to the screen as TN mode, but perpendicular to the screen, and each pixel is composed of multiple liquid crystal molecules with this vertical orientation.
2 PVA (patterned vertical alignment.
vertical alignment configuration) wide view technology (soft screen), PVA wide view technology also belongs to the category of VA technology, in fact, it is very similar to MVA, can be said to be a kind of deformation of MVA.
PVA uses transparent ITO electrode to replace the liquid crystal layer protrusion in MVA.
transparent electrode can obtain better opening rate, This mode greatly reduces the possibility of "bright spot" on LCD panel.
in the era of LCD TV, the status is equivalent to "long tube" in the era of kinescope TVSamsung's PVA mode wide view technology is widely used by Japanese and American manufacturers due to its strong production capacity and stable quality control system.
at present.
this technology is widely used in medium and high-end LCD TV.
(S-PVA is an improved PVA Technology).
Fourth, CPA (continuous pinwheel alignment.
continuous fireworks arrangement) mode wide view technology (soft screen), CPA mode wide view technology is strictly a member of the VA camp.
the liquid crystal molecules radiate toward the central electrode in a fireworks like arrangement.
because the electric field on the pixel electrode changes continuously.
therefore, this wide view mode is called "continuous fireworks like arrangement" mode.
and CPA is promoted by sharp, the father of liquid crystal.
it should be noted that sharp has always advocated ASV in fact does not refer to a specific wide perspective technology, it uses TN + film, VA The products of CPA wide view technology are collectively referred to as ASV.
in fact, only CPA mode is sharp's own wide view technology.
the products of this mode are basically equivalent to MVA and PVA.
that is to say.
Sharp's LCD TV does not necessarily use sharp's own CPA mode LCD panel, It may use the VA mode panel of Taiwan manufacturer or the LCD panel of other manufacturers.
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