STN is also the material type that we contact most, which is mainly divided into CSTN and DSTN. It is a passive matrix liquid crystal device, so it consumes less power and saves electricity, but the response time is slow, 200 milliseconds.
CSTN generally adopts transmission lighting mode, and external light source must be used for lighting, which is called backlight, and the lighting source should be installed behind LCD. TFT (thin film transistor) is a kind of thin film field effect transistor, which belongs to an active matrix liquid crystal display. It can "actively" control each independent pixel on the screen, which can greatly improve the reaction time. Generally, the reaction time of TFT is relatively fast, about 80 milliseconds, and the viewing angle is large, which can generally reach about 130 degrees, and it is mainly used in high-end products. The so-called thin film field effect transistor (TFET) means that each LCD pixel is driven by a thin film transistor integrated behind it. So that screen information can be displayed at high speed, high brightness and high contrast. TFT belongs to active matrix liquid crystal display, which is driven by "active matrix" in technology. The method is to control the opening and closing of any display point by using the transistor electrode "active pull" made by thin film technology. When the light source illuminates, it first passes through the lower polarizer, and the light is transmitted by the liquid crystal molecules, so as to achieve the purpose of display through shading and light transmission.
TFT-LCD liquid crystal display is a thin film transistor type liquid crystal display, that is, "true color" (TFT). TFT liquid crystal technology accelerates the development of mobile phone color screen. Many new-generation color screen mobile phones support 65536 color display, and some even support160,000 color display. At this time, the advantages of high contrast and rich colors of TFT are very important.
TFT LCD is mainly composed of fluorescent tubes, light guide plates, polarizers, filter plates, glass substrates, alignment films, liquid crystal materials, thin transistors and so on.
On behalf of motorcycle MB860 HTC incredible S Lenovo music mobile phone Samsung I9 100 Sharp 72 18U iphone 4 LG P350
Advantages of the screen: good brightness, high reduction, splicing, fast response, high contrast, high visibility, low granularity, good color and good black and white performance.
TFT material screen
TFT screen is the most commonly used and common material on mobile phone screen at present. The full name of TFT is TFT-Thin Film Organizer, which is a kind of active matrix liquid crystal display AM- LCD. TFT is equipped with a special lamp on the back of liquid crystal, which can actively control each independent pixel on the screen, thus greatly improving the reaction time. Because TFT is an active matrix LCD, the arrangement of liquid crystals can be remembered, and it will not recover immediately after the current disappears. TFT also improves the phenomenon of STN flicker (water ripple)-blur, and effectively improves the playback ability of dynamic pictures.
TFT screen structure
Each pixel of TFT liquid crystal has a semiconductor switch, and each pixel can be directly controlled by point pulse, so each node is relatively independent and can be continuously controlled, which not only improves the response speed of the display screen, but also accurately controls the display color scale, so the color of TFT liquid crystal is more realistic. TFT liquid crystal display is characterized by good brightness, strong layering and high reduction, but it also has the problem of insufficient power consumption. UFB LCD is a new type of mobile phone LCD released by Samsung in March 2002, which has the characteristics of ultra-thin and high brightness. UFB-LCD is a display screen specially designed for mobile phones and PDA. With ultra-thin and high brightness, it can display 65536 colors, reaching the resolution of1.280x65,438+0.600. The display screen also adopts a special grating design, which can reduce the pixel spacing and get better picture quality.
The contrast of UFB LCD screen is twice that of STN LCD screen, and its brightness is equivalent to that of TFT display screen in 65536 colors, but its power consumption is less than that of TFT display screen, and its price is similar to that of STN display screen, which can be said to combine the advantages of these two existing products. Organic light emitting display (OLED) is a new product on mobile phone LCD, which is called "dream display". Organic light emitting diode display technology is different from the traditional liquid crystal display mode. It does not need backlight, and uses very thin organic material coating and glass substrate. These organic materials will emit light when current passes through them. In addition, the OLED display screen can be made lighter and thinner, with a larger viewing angle, and can significantly save power consumption. Among the two major organic light-emitting diode technology systems, the low-molecular-weight organic light-emitting diode technology is mastered by Japan, while the technology and patents of polymer PLED (the so-called OEL of LG mobile phone is the product of this system) are mastered by British technology company CDT. Compared with PLED products, colorization is still difficult.
However, although organic light-emitting diodes with better technology may replace LCD such as TFT in the future, organic light-emitting display technology still has shortcomings such as short service life and difficult screen enlargement.
These differences between organic light-emitting diodes and TFT and SLCD/ASV are as follows: the latter is a kind of liquid crystal, which needs light to see the image clearly, while organic light-emitting diodes do not, and each pixel of organic light-emitting diodes can emit light. Organic light emitting diodes can be divided into two types: passively driven PMOLED and actively driven AMOLED.
POLED is generally monochrome, and it will be smaller on some mobile phones. For example, the sub-screen of a few tenths of an inch used to display the time and status of the mobile phone is POLED. There is also AMOLED, full name: active matrix/organic light emitting diode, which can be colored. In terms of display efficiency, AMOLED has the advantages of faster response speed, higher contrast and wider viewing angle, which are inherently superior to TFT LCD. In addition, AMOLED has self-luminous characteristics, so it can be made thinner and more power-saving than TFT. There is another more important feature. AMOLED without backlight can save the cost of backlight module, which accounts for 3 ~ 4% of TFT LCD, but in other cases, it is slightly more grainy than the same resolution.
In recent years, the application of AMOLED has been greatly improved, not a few applications a few years ago. For example, Samsung Galaxy S series and Microsoft Lumia series Motorola MOTO X all use AMOLED screens. In addition to foreign mobile phones, some domestic mobile phones such as OPPO, VIVO and Meizu all use AMOLED screens.
We can see the "Super AMOLED PLUS" technology in the media, which appears on Samsung's dual-core models. The improvement is that if calculated in pixels, the number of pixels of the new display screen will increase by 50%, and the contrast and outdoor readability will be improved compared with the previous Super AMOLED screen. IPS (in-plane switching) hard screen technology is an advanced LCD panel technology in the world. A hard screen is a film with a layer of resin on its surface, just like people wearing glasses. The reason why IPS hard screen has a clear and ultra-stable dynamic display effect depends on its innovative horizontal conversion molecular arrangement, which changes the vertical molecular arrangement of VA soft screen, so it has a more stereoscopic and stable liquid crystal structure. From the surface, the hard screen is to add a hard protective film on the LCD panel to prevent the LCD screen from being poked by external hard objects.
IPS hard screen technology is the most advanced LCD technology in the world. Compared with traditional soft screen LCD, IPS hard screen LCD has faster response speed and smoother moving picture. It has the following advantages: 1, dynamic picture, no afterimage; 2, dynamic picture, uniform reaction speed; 3, dynamic picture, no color shift.
Apple iPhone 4 uses IPS screen, and of course it also adds retina screen display technology. Pixels per inch reach 326ppi, and 300ppi is the resolution that people can see. 326ppi can make you feel like looking at paper products when you look at the display screen. Hence the name "retina display screen". SLCD, the full name of ultra-clear liquid crystal display, was developed by Sony Corporation. With the gorgeous contrast of Super AMOLED, the color is warmer and more natural according to the characteristics of LCD, which is suitable for human eyes to watch. Moreover, according to the typesetting of LCD, its resolution is consistent with the nominal and the screen is clear. SLCD is also a LCD screen, which does not emit light by itself. It can be regarded as a super version of TFT.
The resolutions of ultra-clear LCD and Super AMOLED are both 800*480, and the display granularity of ultra-clear LCD is smaller. In terms of fineness, there is no obvious graininess at a distance of 50CM from the eyes. Super AMOLED has obvious advantages in color and brightness. Ultra-clear LCD has a slightly whiter screen and lower color under high brightness. There is not much difference in graininess between SA screen and ultra-clear LCD. In fact, there is no obvious difference in reaction speed. Relatively new HTC high-end machines all use SLCD screens.
SLCD can meet the needs of different occasions and different signal inputs, with a service life of over 50,000 hours, no burns and injuries, and low maintenance cost. Any number of units can be combined to display a complete picture, and any picture can be superimposed on other pictures. Through the software, any signal can move on the spliced curtain wall in units of one screen. In addition, the viewing angle of the screen is also very good. ASV(Advanced Super View) technology is another breakthrough of Sharp's LCD panel production technology, which is mainly used in Sharp's high-end LCD. This technology mainly improves the viewing angle, reaction time, color contrast and screen brightness of the LCD screen by reducing the spacing between particles on the LCD panel, increasing the aperture on the LCD particles and adjusting the arrangement of the LCD particles as a whole. Under the comparison of the same screen area, the parameters and effects of the screen with ASV technology are substantially improved compared with those of the ordinary LCD without ASV technology. For example, T 1520, T 1620, T 1820 and other series models are obviously superior in parameters and effects compared with the models with the same screen size on the market.