【 Weak current College 】 correct understanding of the led display key performance indicators

Starting in 1998, after five years, led display Recycling Council (now China optical Association led display Branch) organization efforts, the led screen test method "industry standard (hereinafter referred to as the" standards ") is about to release. In order to properly guide the user to understand the performance indicators for led display, LED display market specification with a very important significance. In order to better implementation of standards, make the following recommendations.

1 maximum brightness

At the end of last year to discuss industry standards ", for" maximum brightness "this important performance did not give a definite characteristics requirements, this is in line with GB/T1.2-2002. In the standardization work part 2: standard normative content of technical elements to determine the method of "determined by supply-side 5.4.3 numerical" reference: "If you allow the diversification of the product, the product of some attribute values may not make regulations (although these characteristics to the product's properties have a noticeable impact)". Because the led display using the environment vary illuminance (that is, most people say the brightness of the environment), so "for most complex product, as long as the standards set forth in the corresponding test methods, the supplier shall provide a copy of the performance data (product information) on the list than standard in specific performance requirements better." These are consistent with international standards, but it also resulted in a competing bid unrealistically rivalries, and the user does not understand this, cause many bids in "maximum brightness" are often much higher than the actual needs. Therefore, it is recommended that in order to guide the user to the correct understanding of the led display of "maximum brightness" in the performance indicators, the industry is necessary to give a guidance: on some occasions, the use of different illumination, led display monitor's brightness to achieve what values you can meet the requirements.

2-color dominant wavelength errors

Multiplies the dominant wavelength error indicators and error from the "base color wavelength to the" base "instead of a primary wavelength error" and is better able to explain this indicator reflects the led display what characteristics of a. Color of main wavelength corresponds to the human eye observed color tones, a mental capacity, was the distinction between the color of a property. While this industry-standard provisions of performance requirements, literally, the user is unable to understand that it is a reflection of the led display color uniformity of an index. Therefore, is to guide the user to find out what the term and then understand the index or from the customer point of awareness and understanding of the led display, and then gives the user to understand the performance characteristics of chm? like previously mentioned T1.2-2002 GB/(standardized for the work of the second part of the standard normative technical elements of the content determines the method of product standards of one of the principle that "the performance principle": "as long as possible, the requirements should be expressed by the performance characteristics, rather than design or descriptive characteristics, this approach to technology development, with a maximum room". "Color dominant wavelength error" is a design requirement, if only to "color uniformity," instead, there is no limit on what wavelength LED. To the user, as long as you guarantee led display color is uniform, regardless of what you are used to achieve technical means, to technology development, leaving room for possible so far to the development of the industry.

3 duty

As described above in "performance principles" and "whenever possible, should be expressed by the performance characteristics, rather than design or descriptive characteristics, this approach to technology development, with a maximum room". We believe that the "duty" is a purely technical design requirements, should not be done for led display product standards of performance indicators; we understand that any user would care what display driver duty, they care about is the display of results, instead of our technology; we need their own manufacturing such technical barriers, in restraint of trade, technology development?

4 refresh frequency
From the standard method of measurement, seem to ignore the user really cares, it's also not very good considering the various manufacturers with driver, driver and is not a test, resulting in difficulties. For example, Shenzhen stadium full color screen, in the expert's sample test, the test of this indicator presents many problems. "Refresh rate" a frame displays a countdown to the time needed to display as a light source, that is the light blinking frequency. We can use a similar sense of "optical frequency counter" instrument directly test display of lights blink rate to reflect the indicators. We do this test using any color oscilloscope measurements of led driver current waveform to determine the "refresh rate", in the white field measured 200Hz; 3-level grayscale, and other low-to-gray, the measured frequency up to 10 kHz, and measurement; whether PR-650 spectrometer at White point, 200, 100, 50 levels, grayscale, the measuring light blinking frequency are 200Hz.
The above points just for several led display characteristics of a simple description, there are many bidding in the "working life" and the "mean time between failures," and so on, there is no test method can in a relatively short period of time confirms the led display is in line with the stability, reliability, or life, etc.; shall not be provided for these requirements. Producers can be made to ensure, but cannot replace the requirements, it is a business concept, the concept of the contract, instead of technical concepts. Association on this should be a clear statement that, for users, producers and the industry will be very beneficial.

How to guide the user to the correct understanding of led display such a complex system of products, or to engage in trade associations more points led display technology forum, from reality and from a user perspective to analyze this product to guide the user to the correct understanding of LED display screen.