The main performance indexes LED display analytical

Beginning in 1998, after five years, in the LED display branch (now China light association LED display branch), the organization efforts LED display industry standard test method "(hereinafter referred to as" the standards ") is releasing implementation. Thus correctly guide users understand the performance index of the LED display on standardizing the LED display market has the extremely vital significance.
In order to better implement standard, put forward the following Suggestions.

1 maximum brightness

Late last year the industry standard in the discussion about "maximum brightness of the important performance without giving a definite property requirements, it is in the GB/T1.2-2002. In the standardization of section 2: standard guidelines for the technical factors in normative method to determine the content of 5.4.3 determined by the supplier of "mentioned in the numerical" : "if allowed, the products have diversified products without some characteristics of the value (although these characteristics make provisions for the performance of our products have obvious influence)". Because the LED display using environment differ in thousands ways, intensity of illumination (which is commonly spoken environment is different, so brightness) "for most complicated by the standard of product, as long as the corresponding experiment method, then the supplier provide a performance data (product information) than the standard list of specific performance requirement better". These are all accord with international standard, but it also created in the competition of one-upmanship bid, users impractical and don't understand this, caused many the requirements of the "biggest tender brightness" tend to be far higher than the actual needs. Accordingly, the proposal is in order to guide the user correctly understand the LED display "maximum brightness" this performance index, industry is necessary to give a guidance: in some occasions, in different illumination use environment, the LED display brightness to achieve what value can meet the requirements.

2 gezer main wavelength error

Will gezer main wavelength error, from "gezer wavelength index changed to" gezer error ", "main wavelength error more able to explain this index reflects the LED display a what characteristics. The main wavelength eye color equivalent of the observed color tonal, is a psychological quantity, is the color of a kind of attribute separated from each other. And this industry standards of performance requirements, literally, the user is unable to read that it reflects the LED display color uniformity index. Therefore, is guide users to find out this term and then understand this index? From the Angle of customer was the first to recognize and understand the LED display, and then presents the user can understand the performance characteristics of simple? As mentioned in the GB/T1.2-2002 (standardization work guideline in section 2 of standard of technical factors determine the content of standardized methods of about product standards set in one of the principle that "performance principle" : "as long as possible, requirements shall be expressed by the performance characteristics, instead of design and describe characteristics to express, this kind of method to leave room for largest technical development." "gezer main wavelength error" is a design requirement, if by "color uniformity" instead of, would not exist. What wavelength of limited LED to users, as long as you promise LED display color is uniform, without thinking about what you are using the technology to achieve technical development, to leave as much leeway, so to the industry's development greatly beneficial.

As said above "performance" principle "as long as possible, requirements shall be expressed by the performance characteristics, instead of design and describe characteristics to express, this kind of method to leave room for largest technical development. We think, "390v" is a design technology requirements, should not be LED display product standards as a performance index; Everybody is very understand, what users would care display driver 390v, they do care about screen effect, not our technical implementation; We should make such technical barriers, limit the technology of industry of development?

4 refresh frequency

From the perspective of the standards of measurement methods, seem to ignore the user really care about, and it is not very good considering each manufacturer USES drive IC and drive circuit and the way is differ, causing the test difficulty. Such as shenzhen stadium in full color bidding, the sample tests, the experts in this index test will bring many problems. "Refresh frequency" a frame shows the reciprocal of the time needed for the screen as a luminous, light source, that is the flashing light frequency. We can use a similar "light sensor frequency plan" instruments of direct test screen to reflect light blinking frequency, the index. We've done this aspect of testing using an oscilloscope measurement of any color LED drive current waveform to determine the "refresh frequency", measured in white off-court 200HZ; At level 3 gray etc, low grayscale KHZ, dozen high frequency measurement using PR - 6.5 spectrometer measurement; No matter in white field or in 200, 100, level 50, such gray level are flashing frequency source metering 200HZ.

All of the above only for several LED display characteristics do a simple explanation, and many of the bidding process meet of "working life", "MTBF" etc, not a test method can in the short term confirmed the LED display meets the stability, reliability or life requirement; Should not stipulate that these requirements. Producers can make sure, but can not replace the request, it is a business concepts, contract concept, not a technology concepts. Industry association should have a clear about that for the user, producers, and the entire industries will be very beneficial. How to guide users to correctly understand the LED display such a complex system products, or to industry association LED display technology to make some more BBS, many from set out actually, from the user's perspective of this product, guide the user correctly understand the LED display.