Small pitch led screen compared to traditional LCD and DLP

Small pitch led screen compared to traditional LCD and DLP

Small pitch led screen Advantages and disadvantages of different display technologies:

1. Joint problem. LCD and PDP have the problem of splicing, DLP is slightly better, projection fusion can process the splicing area when it is handled properly; small spacing LED display technology has no splicing at all.

2. Display effect. From the gray level, contrast, brightness, refresh rate and other indicators, DLP rear projection and projection and fusion technology display the worst results (determined by the physical properties of projection), LCD display effect is better, but after a long time of use, there are dark edges and black angles due to brightness attenuation, in addition, there will be brightness and color differences between the screen and the screen, and the human eye is very sensitive to the differences;

LED display technology has good gray level, contrast, refresh rate and other indicators. It can also easily solve the problem of light attenuation through point by point correction, but the biggest problem lies in two points: ① dead light: the standard of dead light rate of outdoor LED display screen is generally 1 / 10000 to 3 / 10000, but the standard of small spacing led needs to be greatly improved. Take the small spacing LED display screen of p2.5 specification as an example, its per square meter. There are 160000 lamp beads in total; if the spacing is further to 1mm, there will be 1 million lamp beads per square meter. At this time, according to the standard requirement of "no more than 3 bad spots" of LCD screen, it is almost impossible for LED display screen to reduce the dead lamp rate to 3 parts per million. ② the contradiction between brightness and grayscale: one of the most significant differences between indoor and outdoor applications is the change of ambient light. When the LED display is used outdoors, the intensity of sunlight in the daytime is very high, so the outdoor LED display needs to be bright, bright and bright! The higher the brightness of the display, the higher the technical specifications of the display. However, for indoor use, the brightness of the LED display screen should be greatly reduced due to long-time viewing. The brightness range of reference home TV is 350 CD / ㎡ - 500 CD / ㎡; the brightness range of DLP splicing wall is 250 CD / ㎡ - 400 CD / ㎡; the brightness range of LCD splicing wall is 450 CD / ㎡ - 700 CD / ㎡. As a self-illumination display technology, LED is different from passive illumination, and the human eye is more sensitive, so it needs lower brightness for the human eye to be comfortable. LED display needs to be less than 300 CD / m2 to achieve the best viewing effect of human eyes (internationally recognized standard is that viewing at a brightness of more than 700 CD / m2 will cause harm to human eye health, in addition, some special application areas have more stringent requirements for "low brightness and high gray", for example, TV studio sometimes even requires the brightness of the display screen within 100 CD / m2) It is not difficult to find that there is a big gap between the brightness of the existing display screen and the actual application brightness by looking at the specifications of the small spacing LED display screen in the current market. Take a listed company that produces small spacing LED products in Beijing as an example. The company's official website clearly indicates the specifications of small spacing LED products. The brightness value is greater than 1200cd / ㎡, far higher than the comfort zone. Professional test experts in the industry have carried out a large number of practical tests on small spacing LED display screens of many manufacturers and found that when the brightness of the display screen drops to 500 CD / ㎡ or even from 600 CD / ㎡ down, the picture has begun to show a more obvious gray loss phenomenon. And with the further decrease of brightness, the gray loss is more and more serious. When the brightness is reduced to below 200 CD / ㎡, the gray level of most of the display screen is greatly lost, and the image quality is almost "unsightly". Therefore, how to achieve the minimum loss of gray level under the brightness level of 300 CD / m2 is a threshold for LED display application enterprises, which is also the moat of excellent enterprises.

3. Resolution. DLP and LCD have high resolution, and the resolution of a single 60 Inch display unit can reach 2K HD, while the resolution of small spacing fine pixel LED display technology is lower than other technologies on the premise of controllable cost because the pixel points are composed of lamp beads. For example, the resolution matching between display screen and signal source, outdoor LED display screen used in advertising and other fields does not need standard resolution, customers only care about display effect and brightness. After the small spacing LED display screen enters the indoor application, the downstream application fields expand rapidly, such as command, control, monitoring and other fields, often need the display screen to match the standard resolution signal output by each subsystem, such as 1920 × 1080 signal of HD camera, etc. Within the specified size, the standard LED display box may not be able to splice the required standard resolution.

4. Cost. Among all the indoor narrow fine pitch led screen large-screen display solutions, LCD splicing, projection and fusion are the lowest cost (because the lowest cost LCD splicing wall accounts for the largest share of the indoor display field), followed by PDP splicing. At present, compared with DLP rear projection splicing, it is difficult to say which is higher or lower. Because of the large cost difference of small spacing LED display screens with different point spacing specifications, the price per square meter of p1.9 display screen is equivalent to that of DLP rear-projection splicing, but considering the difference in gross profit margin, the cost is even higher than that of DLP splicing products. For the industry users with the highest benefits, considering the comprehensive cost-performance ratio on the premise of meeting the application requirements, small spacing narrow pitch led screen LED may not be the first choice. High cost has always been the main problem of small spacing led, although small spacing LED has many advantages. However, with the continuous investment of the market and the rapid improvement of small spacing LED technology, the cost of technology has been greatly reduced. At present, the commercial cost of products below P1.2 is too high for users. This also means that the current LED technology can not be popularized and popularized without big innovation and Small pitch led screen.