thin film transistor
TFT？ Thin film transistor is an active matrix liquid crystal display? As a kind of AM-LCD, TFT is equipped with a special lamp on the back of LCD, which can "actively" control each independent pixel on the screen. This is the origin of the so-called active matrix TFT(activematrixTFT), which can greatly improve the reaction time. Generally, the reaction time of TFT is relatively fast, about 80ms, while STN is 200 ms, and flicker will appear if it is to be improved. Moreover, 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. Compared with STN, TFT has excellent color saturation, reduction ability and higher contrast, but its disadvantages are higher power consumption and higher cost.
TFD screen
TFD is the abbreviation of thin film diode. Because of the high power consumption and high cost of TFT, it undoubtedly increases the usability and cost of mobile phones. TFD technology was developed by Seiko Epson, a mobile phone screen giant, and was specially used for mobile phone screens. It is a compromise between TFT and STN. The brightness and color saturation are better than STN, but it also saves more power than TFT. TFD is characterized by "high image quality, ultra-low power consumption, miniaturization, dynamic image display ability and fast response time". The display principle of TFD is to equip each pixel on the LCD with a separate diode as the control source. Because of this separate control design, each pixel will not affect each other, so dynamic pictures and bright colors can be displayed on the TFD screen without afterimage. Like TFT, TFD is also driven by active matrix.
Initially developed TFD can only display 4096 colors, but if image processing technology is adopted, it can display images equivalent to 260,000 colors. But compared with TFT, it is still inferior in color display. At present, the commonly used mobile phones using TFD are NECN8, Samsung SCH-X3 19, LGCU8280 with 260000 colors.
UFB screen
UFB is the abbreviation of ultra-fine (bright). In March 2002, Samsung Electronics, which occupies the first place in the global LCD market, released a UFBLCD for mobile phones, which is characterized by ultra-thin and high brightness. In design, UFB LCD also adopts a special grating design, which can reduce the pixel spacing and obtain better image quality. Generally, UFBLCD can display 65536 colors, and the resolution can reach 128× 160 pixels. At the same time, the contrast of UFBLCD is twice that of STN LCD. 65,536 colors, the brightness is comparable to TFT display, but the power consumption is less than TFT display, and the price is similar to STN display, which can be said to combine the advantages of these two existing products. UFB LCD screen makes the multifunctional mobile phone with super-large color LCD screen closer and closer to us.
At present, the mobile phones using UFBLCD are mainly Samsung mobile phones such as SHGT208 and T508. Generally speaking, there is still a certain gap between UFB and TFT, and the power consumption is not satisfactory.
Super twisted nematic
STN is short for supertwist medical? Is it the LCD that we contact the most? Because the screen of the gray-scale mobile phone we used to use was STN. Compared with previous LCDs, STN LCD is a passive matrix LCD device with the advantage of low power consumption? Its biggest advantage is saving electricity. The display principle of color STN is to add a color filter to the traditional monochrome STN liquid crystal display, divide each pixel in the monochrome display matrix into three sub-pixels, and display the three primary colors of red, green and blue through the color filter, thus displaying a color picture. Unlike TFT, STN belongs to passive liquid crystal? Usually, it can display up to 65536 colors. In addition to gray level STN, STN can also be divided into CSTN and DSTN. CSTN is in color? Generally, transmissive lighting is used? The transmission screen should be illuminated by an external light source, which is called backlight, and the light source should be installed behind the LCD. Transmission LCD displays well in normal light and dark light, but it is difficult to distinguish the display content outdoors, especially in sunlight, and the backlight needs power to generate illumination light and consume electricity.
At present, the mobile phones using CSTN are Sony Ericsson T6 18, Philips 820/826, MOTOT720E350 and Siemens S57SL55.
DSTN (Double Super Twisted Nematic Phase) used to be mainly used in some notebook computers. It is also a passive display technology, using two display layers. This display technology solves the drift problem in traditional STN display? Moreover, because DSTN also adopts double scanning technology, the display effect has been greatly improved compared with STN. Because DSTN is scanned by two screens at the same time, a bright line may appear in the center of the display screen during use.
Temporary? Can I use DSTNLCD with Nokia 72 1066 10? It is said that OKWAP's 166 and 163 also use DSTN screens.
Organic light emitting display
Organic light emitting diode? OrganicLightEmittingDisplay？ Is it a new category on mobile phone LCD? It is called "dream show". 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 organic light-emitting diode display screen can be made lighter and thinner, and the viewing angle can be larger, and it can significantly save electricity. At present, among the two major technical systems of organic light-emitting diodes, the technology of low-molecular-weight organic light-emitting diodes is mastered by Japan, and the OEL of the so-called polymer PLEDLG mobile phone is this system, and the technology and patents are mastered by the British technology company CDT. In contrast, the coloring of PLED products is still difficult. And low molecular organic light-emitting diodes are easy to color? Not long ago, Samsung released 65530 color organic light-emitting diodes for mobile phones. However, although organic light-emitting diodes with better technology will replace LCDs such as TFT in the future? However, organic light-emitting display technology still has some shortcomings, such as short service life and difficulty in enlarging the screen. At present, organic light-emitting diodes are mainly used by Samsung. For example, the newly listed SCHX339 uses 256-color OLEDs. As for OEL, it is mainly adopted by LG, and we have all seen it on CU8 1808280.
Other species
In addition to the above-mentioned types of liquid crystal displays. We can also see some other LCDs on some mobile phones. For example, GF screen in Sharp, Japan, and CG continuous crystalline silicon liquid crystal. Are these two kinds of LCD totally different? GF is an improvement of STN? Can improve the brightness of LCD? CG is a high-precision and high-quality LCD, and its resolution can reach the standard of QVGA(240×320) pixels. At present, Kyocera KZ820 is the main user of GF. The first mobile phone using CG is Sharp mobile phone "J-J-SH0 10" released by J-Phone in June 2003, and the European model is GX20.
FTF:Tine thin film transistor, which can improve STN flicker (water ripple) and effectively improve the ability of playing dynamic pictures. Compared with STN, TFT has excellent color saturation, reduction ability and higher contrast, but its disadvantages are higher power consumption and higher cost.
UFB: Ultra-fine & ampBright, which can usually display 65536 colors, and the resolution can reach 128× 160 pixels. At the same time, its contrast is twice that of STN LCD. In 65536 colors, its brightness is equivalent to that of TFT display, but its power consumption is less than that of TFT display, and its price is similar to that of STN display. It can be said that it combines the advantages of these two existing products.
Organic light-emitting diodes: Organic light-emitting displays belong to a new category of mobile phone screen materials, which can be made lighter and thinner, with a larger viewing angle, and can significantly save electricity.
CGS: Continuous grain silicon can improve the display quality and brightness of LCD, reduce power consumption and provide more functions.
Because for most friends, when they buy a machine, they pay more attention to the color of the color screen, whether it is 65536 or 4096, and ignore the material of the screen. In fact, 4096 color TFT screen is often much better than 65536 color STN screen. Therefore, we can't just look at the number of colors. The display effect is roughly ranked as follows: TFT & gtTFD & gtUFB & gt；; Station 1.
The so-called true color refers to TFT screen and false color is STN screen, both of which belong to LCD (Liquid Crystal Display). Compared with STN, TFT has the advantages of clear display, high brightness, smooth animation and no tailing, but there is not much difference between the viewing angle (that is, the maximum angle at which the screen content can be clearly seen) and the interference degree of external light sources. But if you compare two mobile phones with the same number of colors, using TFT and STN screens respectively, you will find a very obvious difference.