The liquid crystal module (LCM) is simply an LCD screen and backlight assembly. For example, the display part of an LCD TV is a liquid crystal module, and its low temperature is equivalent to a picture tube in a CRT. The other parts include the power supply circuit, signal processing circuit, etc., and of course the shell or something.
LCD modules are mainly divided into screen and backlight components. The two parts are assembled together, but work independently of each other. The principle of liquid crystal display is that the backlight unit emits light, and the light is displayed through the LCD screen. The function of the LCD screen is to control and process these lights by pixels to display images.
The LCD panel is the main component of a liquid crystal display, accounting for nearly 80% of the cost of a liquid crystal display. At present, there are not many manufacturers with panel manufacturing technology in the world. Only SHARP, Samsung, LGD, Taiwan Innolux, AUO and other manufacturers have core technologies. In the past, most terminal manufacturers used their LCD panels. Of course, with the rapid development of mainland panel manufacturers, domestic companies such as BOE, Shentianma, Huaxing Optoelectronics, etc. have also started to accumulate their own patented technologies, and the panels produced by them have also been widely used by terminal manufacturers.
LCD panel specification classification
The so-called dead pixels are a collective term for pixels that cannot be displayed normally on a liquid crystal panel. The liquid crystal panel is composed of a plurality of pixels, and the liquid crystal substance on each display point is completed by changing the light transmission and the same state under the control of an electric signal. With a resolution of 1024 * 768, the LCD panel has a total of 786,432 display points. It is difficult to completely guarantee that there are individual problems with so many points. At present, the technology cannot completely overcome the situation of no dead pixels. Therefore, the panel classification is also judged based on the number of dead pixels. Manufacturers generally avoid LCD panels with broken pixels and sell LCD panels with no or few broken pixels at a high price, while those with a large number of broken pixels are dealt with at a low price.
The main grading standards for panels are:
Korean manufacturers, A level below 3
Japanese manufacturers, A level below 5
Taiwanese manufacturers, A level below 8
Key indicators of mainstream LCD brands:
AA level: The LCD display without any dead pixels is AA level.
Level A: Less than 3 dead pixels, of which no more than one bright spot, and the bright spot is not in the center area of the screen.
Level B: less than 3 dead pixels, of which no more than two bright points, and the bright points are not in the central area of the screen.
In addition, the quality of a liquid crystal panel is related to the resolution, brightness, response time, contrast, etc. of the liquid crystal panel. The control IC, filters, and orientation films used in the manufacture of LCD panels are closely related to the contrast of the panel. For ordinary users, a contrast ratio of 350: 1 is sufficient, but this level of contrast in the professional field is not enough. User needs.