Brief introduction to color LCD
A Color Liquid Crystal Display generally uses a TFT (Thin Film Transistor) thin film transistor liquid crystal display. The principle is: depositing a layer of silicon on a glass substrate, forming a transistor array by a process such as printing lithography, each pixel is provided with a semiconductor switch, and processing thereof The process is similar to large scale integrated circuits. Then the liquid crystal is poured between the two pieces of glass. Since each pixel can be directly controlled by the point pulse, each node is relatively independent and can be continuously controlled. This design not only improves the response speed of the display screen. At the same time, the display gray scale can be precisely controlled, so the color of the TFT liquid crystal is more realistic, which is called true color. TFT is divided into polysilicon, amorphous silicon and monocrystalline silicon. In March 2004, Samsung released a liquid crystal display device for mobile phones, called UFB (Ultra Fine & Bright) LCD, which has ultra-thin, high brightness. specialty.
Color LCD Screens Compared with LCD monitors, color LCD screens have advantages in terms of brightness, power consumption, viewing angle and refresh rate. The power consumption ratio of LED to LCD is about 10:1, and the higher refresh rate enables LEDs to perform better in video, providing a viewing angle of up to 160° and displaying various text, digital, and color images. And animation information, you can also play TV, video, VCD, DVD and other color video signals, multiple screens can also be broadcast online. The single element of the organic LED display has a reaction speed of 1000 times that of the LCD screen. It can also be taken under strong light and is suitable for low temperatures of minus 40 degrees. LED technology can be used to produce displays that are thinner, brighter, and clearer than LCDs, and have broad application prospects.
Screen advantages and disadvantages:
1. STN LCD screen
Is a passive matrix LCD device, its advantage is low power consumption? Has the greatest advantage of power saving. The display principle of color STN is to add a color filter to the traditional monochromatic STN liquid crystal display, through the color filter to display the three primary colors of red, green, and blue, the color picture can be displayed. STN screen display response time is slow, about 200 milliseconds, the tail phenomenon is serious when playing animation.
2. TFT LCD screen
It is an active matrix type LCD screen, with a special lamp on the back, which can actively control each independent pixel on the screen. This is also known as the active matrix TFT. The response time is relatively fast, about 80 milliseconds, and The viewing angle is large, usually about 130 degrees. But the disadvantage is that it consumes more power and the manufacturing cost is also relatively high.
3. OLED LCD screen
It is an organic light-emitting display, which is essentially different from the traditional LCD display method mentioned earlier, that is, it does not require a backlight. It uses a very thin organic material coating and a glass substrate. When current passes, these organic materials will Glow. Therefore, the OLED LCD screen can be made lighter and thinner, with a larger viewing angle, and at the same time more power saving. However, the service life is short and the screen cannot be made larger.
4. LTPS LCD screen
It is a new generation of technical products derived from TFT LCD. The LTPS screen is manufactured by adding a laser processing process to the traditional amorphous silicon (a-Si) TFT-LCD panel. The number of components can be reduced by 40%, and the connection part can be reduced by 95%, which greatly reduces product failures. The odds. This kind of screen has greatly improved energy consumption and durability. The horizontal and vertical viewing angle can reach 170 degrees, the display response time can reach 12ms, the display brightness can reach 500 nits, and the contrast ratio can reach 500:1.
MP4 products on the market mainly use the first three screens. The STN screen used in ordinary products, from the characteristics of this screen, we can see that its display effect is not very good, and the color is not rich. Although TFT LCD screens are widely used in notebook products, they have no advantages when applied to MP4 due to cost and volume. Although OLED has excellent color performance, its short service life limits its use. The most suitable screen for MP4 display is the LTPS screen. It can be said that it is a display technology born for MP4.