What is the TFT LCD?
TFT LCD is an abbreviation for Thin Film Transistor-Liquid Crystal Display,TFT LCD technology is a technology that combines microelectronics technology with liquid crystal display technology,People use the technology of microelectronics fine processing on Si to transplant TFT arrays on large-area glass, and then use the mature LCD technology with the array substrate and another substrate with color filter. Forming a liquid crystal cell in combination, and then going through a post-process such as polarizing film coating, etc., and finally forming a liquid crystal display (screen).
Main Components of TFT LCD Module
- TFT LCD is an active matrix LCD driven by a circuit composed of an IC and an FPC
- Backlight(Backlit),it is a component for light resources
- Touch panel(Touchscreen),it is a Multi-layer composite film that accepts touch signals and feeds them back to the processor for processing.
- FPC(Flexible printed Circuit),it has Highly reliable,excellent flexible circuit board with with high density, light weight and thin thickness
In a TFT LCD, the display of each pixel is divided into three sub-pixels of R, G, and B. The total number of pixels in an LCD is the resolution of the LCD.(PPI=
QQVGA 128*160 QCIF+:176*220
2.Brightness:Luminous intensity per unit area in cd/m2
The LCD operates at normal operating voltage, and the vertical incidence measures the brightness of the bright (white) picture. The average value is defined as the brightness value of the LCD.
The brightness ratio of light passing through the front of the LCD is the transmittance of the LCD.
The ratio of the brightness of the bright state to the brightness of the dark state measured by the liquid crystal display operating at a normal operating voltage
The contrast of the LCD is related to the viewing angle (ie, the angle of view of the human eye). The characteristic that the contrast changes with the viewing angle is called the viewing angle characteristic. The viewing angle characteristics are determined by the birefringence characteristics of the liquid crystal molecules because LC is elliptical and has a relationship in which the major axis and the minor axis are unequal lengths. Therefore, when light enters the LC, it will cause different refractive indices due to such a relationship, thereby causing different viewing angles.
Reference is made to the clock hour orientation. The angle of view from the observation angle of 3, 6, 9 and 12 points is the standard (lowest acceptable value) angle, called the effective angle of view, also known as right, bottom, left, and upper angles.
7.The Gray-Scale Reversal Direction
The Gray-scale reversal direction is the observation direction in which the picture is black, that is, the perspective of our company defines the direction. The grayscale reverse direction is indicated in the Taiwanese glass specification and is applicable to TN glass.
The AA area is an area composed of pixels on the TFT-LCD, and can also be an area, Active Area.
The VA area refers to the assembly to the customer’s product. Observable LCD area.
10.Main Interface:MCU, RGB, MIPI
MCU: The signals required for MCU mode are WR, RD, RS, RESET, CS.
CS, RS, WR, RD (I80 or 8080)
CS, RS, E, RW (M68 or 6800)
DB0-DB7: 8 bits DB0-DB8: 9 bits
DB0-DB15: 16 bits DB0-DB17: 18 bits
RGB: RGB mode requires signals HSYNC, VSYNC, ENABLE, CS,
RESET, some also need RS.
Data line: DB0-DB17, R6G6B6
MIPI: (Mobile Industry Processor Interface) mobile industry processor interface
The signals required by MIPI mode are DATA_N, DATA_P
Lower power consumption, higher data transfer rates and smaller PCB footprints, and optimized for mobile devices, making them more suitable for mobile and smart tablet connectivity.
(1) Good use characteristics: low-voltage application, low driving voltage, flat, thin and light, saving a lot of raw materials and space. Low power consumption, its power consumption is about one-tenth of CRT display, reflective TFT LCD even only about one percent of CRT, saving a lot of energy. TFT LCD products are also available in a variety of specifications, sizes, sizes, convenience, flexibility, maintenance, update, upgrade, and long life. The display range covers the range of applications for all displays from 1 inch to 40 inches, as well as the projected large plane, which is a full-size display terminal. Display quality from the simplest monochrome character graphics to high resolution, high color fidelity, high brightness, high contrast, high response speed of various specifications of video displays. Display methods are direct view, projection type, perspective type, and reflective type.
(2) Good environmental protection characteristics: no radiation, no flicker, no damage to the user’s health
(3) Wide application range, from -20 °C to +50 °C temperature range can be used normally, the temperature-hardened TFT LCD low temperature working temperature can reach minus 80 °C. It can be used as a mobile terminal display, a desktop terminal display, or a large-screen projection TV. It is a full-size video display terminal with excellent performance.
(4) The TFT LCD industry is mature in technology,and the yield of large-scale production has reached more than 90%.
(5) TFT LCD is easy to integrate and update, and it is a perfect combination of large-scale semiconductor integrated circuit technology and light source technology, and has great potential for further development. At present, there are amorphous, polycrystalline and monocrystalline silicon TFT LCDs, and there will be TFTs of other materials in the future, both glass substrates and plastic substrates.