With the development of LED full-color display technology, uniformity has become the most important indicator to measure the quality of display screen. It is often said that led display “little bit brilliant, piece brilliant”, is a kind of image metaphor of serious uneven between pixels and led display modules. The professional terms are “dust effect” and “mosaic phenomenon”.
the insufficient assembly accuracy of display screen in the process of production and installation; the inconsistency of electrical parameters of other electronic components; the nonstandard design of modules and PCB. in which “inconsistency of various performance parameters of LED” is the main reason. The inconsistency of these performance parameters mainly includes: the light intensity is inconsistent, the optical axis is inconsistent, the color coordinate is inconsistent, the light intensity distribution curve of each primary color is inconsistent, and the attenuation characteristics are inconsistent. At present, there are two main technical approaches to solve the inconsistency of LED performance parameters: one is to further subdivide the LED specifications and parameters to improve the consistency of LED performance parameters; the other is to improve the uniformity of display screen through subsequent correction.
also developed from early module correction and module correction to today’s point by point correction. The correction technology has developed from simple intensity correction to intensity color coordinate correction. However, we believe that the subsequent correction is not omnipotent. Among them, the inconsistency of optical axis, light intensity distribution curve, attenuation characteristics, poor assembly accuracy and nonstandard design can not be eliminated by subsequent correction, and even the inconsistency in optical axis, attenuation and assembly accuracy will be worsened.
large outdoor display screen therefore, through practice, we have come to the conclusion that the follow-up correction is only the treatment of the surface, and the subdivision of LED parameters is the root cause, which is the mainstream of the LED display industry in the future.
however, when it comes to the relationship between display uniformity and clarity, there is often a misunderstanding in the industry, that is, to replace the definition with resolution. In fact, the definition of the display screen is the subjective feeling of the human eye on the screen resolution, uniformity (signal-to-noise ratio), brightness, contrast and other factors.
simply reducing the physical pixel spacing to improve the resolution, while ignoring the uniformity, is no doubt to improve the clarity. Imagine a display screen with serious “dust effect” and “mosaic phenomenon”. Even if its physical pixel spacing is smaller and the resolution is higher, it is impossible to get a good image definition. Therefore, in a sense, the main reason for improving the clarity of LED full-color displays is “uniformity” rather than “physical pixel spacing”.