Four aspects of LCD panel identification

06 LCD has grabbed the market's thunder, accompanied by a long period of steep price declines, LCD has become a consumer installed when the darling. Consumers in various brands of various grades of liquid crystal display in the selection, the most powerful basis is often the performance parameters of the liquid crystal display. Response time, contrast, brightness, visual angle these nouns are all familiar with the performance parameters of consumers, and the only concept that does not understand is the level of the LCD panel. In this paper, I will describe the concept of the level of LCD panel, consumers in the purchase of liquid crystal display, especially low-cost products may be used!

1. LCD panel's Bad point

In the absence of the LCD level, the author first introduced the LCD panel on the "Bad point" of the specific concept, so as to be based on this to distinguish the level of the LCD panel. LCD panels are composed of a large number of pixel points, they can display black and white color and red, yellow, blue three primary colors. Then we can see the image displayed by the LCD panel by combining the pixel points with different colors. However, a few pixel points on the LCD panel do not produce color changes, regardless of what the LCD screen shows the image, these pixels will always show the same color. These faulty pixel points cannot be repaired and can only be solved by replacing the entire LCD panel. And these fault pixels are usually divided into two categories, where the "dark point" is no matter how the screen image changes can not show the "black spots", and more annoying is the kind as long as the boot will always glow "bright spot."

The development of liquid crystal display technology is still unable to fundamentally overcome this shortcoming. Because the LCD panel is made up of two glass panels, the middle interlayer is a crystalline droplet of about 5 microns thick. These crystal droplets are evenly spaced and contained in tiny cells, each consisting of three cells forming a pixel on the screen. Under the magnifying glass the pixel is square, and a pixel is a point of light. Each luminous point has a separate transistor to control the strength of its current, if the control of the point of the transistor is broken, it will cause the light point will always light or not light. This is the highlight or dark point mentioned above, collectively referred to as "bad point"!

2. The level of the LCD panel

LCD panel According to the quality can be divided into a, B, C three grades, the basis for the classification is the number of bad points. However, there are no relevant rules and regulations in the world, so the level standards of each country are different. Normally, the number of bad points in the LCD panel within 5 is a class, the number of bad points more than 5 and less than 10 is a B-class, the number of bad points in more than 10 of the C-class panel. In principle, a-level panel is most suitable for the production of the display, but the LCD panel production of B-class panels is inevitable, so the B-class panels are also most of the kitchen display manufacturers to digest. and the C-level panel is completely unsuitable for the production of the display, mostly cut into small area of the LCD panels used in other fields. However, there are very few liquid crystal display manufacturers will use the C-class panel, two or three years ago, there was a low price inferior LCD display disturbed the market turmoil.

Of course, in addition to the number of bad points, B-Class and C-class panels in other aspects of performance can not be compared with a-level panel. Compared with a-level panel, B and C-level panels have relatively uneven brightness, relatively low color saturation, poor image color reduction, and even the appearance of damage. In addition to the use of professional equipment to determine the level of LCD panels, consumers can also use the naked eye for intuitive identification. It is best to use the known A-level panel for comparison, b and C-class panels will immediately show the prototype. In addition, panel manufacturers will also be a-level panel divided into a++, A +, a these three steps, the best quality of the LCD panel for the display of higher quality requirements of consumers. Under normal circumstances, a-level panel of less than 3 dark spots, the number of bright spots is less than 3, while the highlights and bad points of the sum of less than 5; A + Level Panel has fewer than 3 dark dots, and the entire screen has no bright spots and fewer than 3 bad points; a++-level Panel has neither bright spot nor dark spot, the number of bad points is 0. A small number of liquid crystal display manufacturers claim that their display products do not have bright spots, the LCD display is a +-level panel.

3. Panel Identification method

With the intensification of competition and the improvement of technological process level, the manufacturer of LCD screen has improved the raw material standard. Strengthen the production and inspection and other internal quality control, greatly reducing the frequency of the occurrence of bad points. Detect the bad point of the method is also relatively simple, as long as the LCD screen brightness and contrast to the maximum (display anti-white screen) or adjust to the smallest (show full black screen), you will find how many bright spots on the screen and how many dark spots. As long as the number of bad points does not exceed a certain standard, it is normal to appear a number of bad points, but it is best not to lower than a Level Panel standard.

In addition, you can also use professional testing software to test the other indicators of the liquid crystal display. Nokia MONITOR test software, for example, is a test program that consumers can carry around on a disk. The software offers a total of 15 options, namely geometry (geometry), brightness and contrast (brightness and contrast), High voltage (High-voltage), Colors (color), to control Panel/display (Control Panel Display properties), Convergence (convergence), focus (Spotlight), resolution (resolution), moire (water ripple), readability (text sharpness), jitter (jitter), Sound (noise), and so on. For liquid crystal displays, in addition to not test response time, other major performance parameters glance, consumers focus on the bad point is not a cinch. If the color of the display is pure, contrast, dark and light problems, B-Class and C-class panels will have no hiding.

4. The brand of liquid crystal display

B-Class and C-class panels should be eliminated or used for other uses of defective panels, but because of low prices and profits due to a small number of display manufacturers to use. The recent uproar caused by the B-class panel to sneak into the market incident, it is from this. So consumers in the recent purchase of liquid crystal display, must pay attention to the quality of liquid crystal display. Unless the manufacturer clearly claims to have adopted a level above the LCD panel, or buy Word-of-mouth better brand. The display is definitely one of the most competitive areas in the world, a phenomenon that has lasted from the CRT display era to the LCD era.

Samsung, LG, Philips, BenQ, ViewSonic Five manufacturers in the field of display reputation, five major manufacturers in earlier time to start the liquid crystal display market. With preconceived advantages, coupled with the overall display in the field of brand awareness, the five major display manufacturers in the liquid crystal display market has been recognized by many users, but also won a larger market share. As we all know, the difficulty of building a brand is quite large. So for the five first-line manufacturers, the use of B-class panels is absolutely not worth the matter, so their products are still trustworthy. The other is AOC these "new sharp" manufacturers, their products also dare to play "No bright spot" slogan, also worthy of consumer trust.