Users in the purchase of liquid crystal display will often listen to the merchant said: "XX card good, with a screen, XX card not, with the B-screen." What's the difference between a screen and B?
A-level screen than the Grade B screen higher, the lowest grade C. In addition to these three levels, there is also a call is "super a" or "AA grade", that is, than a grade is slightly higher than a few products. Generally speaking, B-and C-level are defective, compared with a-level, B-Class and C-class bad points more, the brightness is relatively uneven, the appearance may also be damaged, and a-level screen price gap may be as high as nearly thousand yuan.
For Samsung, Philips, LG These well-known brands, for the quality of LCD screen is relatively high, will use a "a" level of the screen to ensure quality. Therefore, in the procurement process, the price is not entirely in accordance with a simple brand positioning, but strict adherence to a cost-manufacturing principle.
The bad point is the fixed pixel point on the LCD panel, which is produced during the production process. There are three transistors behind the liquid crystal pixels, corresponding to the red, green, and blue filters, and any one of the transistors will cause the pixel to become a bad point. With a 15-inch $number screen, a total of approximately pixel 1024 768 is required, and a separate drive tube is integrated behind each LCD pixel, and there will inevitably be problems in so many pixel points and drive tubes. The number of bad points is directly related to the technical and technological level of the manufacturer. For the time being, each batch of LCD panels produced usually has a bad point of 20% of the product. With the continuous improvement of technology, some brands of LCD bad point rate has been able to control within 10%, but the 0 bad point rate is still rare.