We have all seen the shaped LED display, so how can a LED display screen be regarded as a very good LED display screen? Four is the key.1. Brightness and viewing angle; the brightness of display screen mainly depends on the luminous intensity and led density of LED. In recent years, the new technology layers of LED in substrate, epitaxy, chip and package are introduced
In particular, the stability and maturity of indium tin oxide (ITO) current spreading layer technology and technology have greatly improved the luminous intensity of LED. At present, the state
In the case of horizontal angle of view of 110 degrees and vertical angle of view of 50 degrees, the luminous intensity of green LED is as high as 4000 MCD, and that of red LED is as high as 4000 MCD
It is up to 1500mcd and 1000mcd for blue tube. When the pixel spacing is 20 mm, the brightness of the display can reach more than 10 000 nit. The display can be used in any environment
All day long
When talking about the perspective of the display screen, there is a phenomenon worthy of our consideration: LED display screen, especially outdoor display screen, people’s observation angle is basically
From the bottom to the top, half of the luminous flux disappears in the vast sky in the form of the existing LED display.
2. Uniformity and definition [LED display]
with the development of LED 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 film” is a kind of image metaphor of serious non-uniformity between pixels and modules. The professional terms are “dust effect” and “mosaic phenomenon”. The main causes of the uneven phenomenon are: the inconsistency of LED performance parameters; the lack of assembly accuracy in the process of production and installation; others
The consistency of electrical parameters of electronic components is not enough; the design of modules and PCB is not standardized.
in which “the inconsistency of various performance parameters of LED” is the main reason. The inconsistency of these performance parameters mainly includes: light intensity inconsistency, optical axis inconsistency and color setting
The results show that the intensity distribution curve of each primary color is inconsistent, and the attenuation characteristics are inconsistent. [LED display price]
how to solve the inconsistency of LED performance parameters, there are two main technical ways in the industry at present: one is to further subdivide the LED specifications and parameters,
The second is to improve the uniformity of the display screen through subsequent correction. The subsequent correction is also from the early module correction, module
Correction, developed 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 optical axis is inconsistent, the light intensity distribution curve is inconsistent, the attenuation characteristics are inconsistent, and the assembly
The error of precision and nonstandard design can’t be eliminated by follow-up correction, and even the optical axis, attenuation and assembly accuracy will be affected by the follow-up correction
The inconsistency worsened.
therefore, through practice, our conclusion is: the follow-up correction is only the treatment of the table, and the subdivision of LED parameters is the root cause, which is the future of LED display industry
Flow. [LED display manufacturer]
and when it comes to the relationship between the uniformity and the definition of the display screen, there is often a misunderstanding in the industry, that is, to replace the definition with resolution. It is obvious
The definition of display screen is the subjective feeling of the human eye on the display resolution, uniformity (signal-to-noise ratio), brightness, contrast and other factors. Simple reduction physics
It is no doubt that pixel spacing improves resolution while ignoring uniformity. Imagine a serious “dust effect” and “mosaic phenomenon”
Even if its physical pixel spacing is smaller and resolution is higher, it is impossible to get a good image definition.
Therefore, in a sense, the main reason restricting the improvement of LED display clarity is “uniformity” rather than “physical pixel spacing”.
3. The display screen pixel is out of control. There are many reasons for the display screen pixel out of control, among which the most important reason is “led failure”. [LED display rental]
the main causes of LED failure can be divided into two aspects: one is the poor quality of LED itself; the other is the improper use method. Through the analysis, we conclude the LED failure
The corresponding relationship between the pattern and the above two main factors.
as we mentioned above, many led failures are usually not found in the regular inspection and testing of LEDs. In addition to the electrostatic discharge, high current
In addition to improper use of high junction temperature and external strength, many led failures are caused by high temperature, low temperature, rapid temperature change or other harsh conditions
The difference of thermal expansion coefficient of chip, epoxy resin, bracket, inner lead, solid crystal glue and PPA cup body results in different internal stress,
Therefore, led quality detection is a very complex work.
4. Service life
the factors that affect the life of LED display screen are internal and external factors. The internal factors include the performance of peripheral components, the performance of LED light-emitting devices, the fatigue resistance of products; and the internal factors
Working environment with LED display, etc. [LED full color display screen]