Method for testing optical attenuation of LED light source

Abstract

The invention discloses a method for testing optical attenuation of an LED light source, which comprises the following steps of fixing the LED light source at one end inside a hollow cylinder with a black inner surface, mounting an illuminometer probe corresponding to the LED light source in a corresponding position of the cylinder, reading an illuminance value; immobilizing the LED light source,reading an illuminance value at fixed intervals, reading for many times and recording each illuminance value; calculating optical attenuation according to data read in many times. The invention has the advantages that the illuminometer can read directly, thereby avoiding incorrectness of test result caused by the test instrument; the illuminometer can be read when lights are available, thereby solving the problem of metering distance; and the cylinder with the black inner surface avoids influence of parasitic lights; after mounting, the LED light source is not moved until result is tested, thereby reducing influences of the position and the angle of the light source, the artificial reading difference as well as improving the accuracy of test.

Description

technical field [0001] The invention relates to a test method, in particular to a light decay test method of an LED light source. Background technique [0002] During the working process of the LED light source, due to the influence of heat and other factors, the phosphor and the chip will gradually age, the electro-optical conversion efficiency of the chip will become lower, and the light emitted by the phosphor will also decrease, resulting in the overall luminous efficiency of the LED light source becoming lower. , This phenomenon is called the light decay of the LED light source. [0003] When the light decay reaches a certain level, the light emitted by the LED light source cannot meet the needs of use, and at this time the life of the LED light source is over. Since the light decay of LED light sources is extremely slow, it usually takes tens of thousands of hours to reach its lifespan. Therefore, the method of measuring the lifespan of LED light sources is to measure...

AI Technical Summary

Problems solved by technology

[0006] 1. Human factors: The light source needs to be removed from the burn-in board for each test. In the process of disassembly, there is a problem of heat dissipation due to the error of the thickness of the heat-conducting adhesive; there is a bad problem of manually provoking the LED light source; there is repeated disassembly of the circuit Poor contact with the fixture; there are errors caused by the distance, position and angle of manually placing the LED light source into the integrating sphere and errors caused by reading test results;

[0007] 2. Factors of testing equipment: especially the integrating sphere optical instrument, no matter how advanced it is, the total luminous flux of each test will deviate, because this is the value obtained by integral calculation by software, not the value of direct test, and it is unstable. The repeatability is poor; and when the distance is too far, the light measured by the integrating sphere is too little, the result is inaccurate, and the effect of stray light is too close

[0009] 4. Light detection distance: that is, the distance between the test instrument and the LED light source. There will be loss during the light propagation process, so the test result will have a large deviation if the distance is too far; the light emitted by the LED light source is directed in all directions, so if the distance is too close, test The light received by the instrument is impure, which will also affect the test results;

[0011] 7. Fixtures: The degree and position of clamping fixtures affect the position and angle of installation

[0012] All of the above factors are easy to cause the original light to drift, so that the measured illuminance or luminous flux of a single LED light source has a large deviation, which seriously affects the accuracy of the light decay test, thus affecting the accuracy of the light decay test

[0013] Moreover, multiple disassembly and assembly lead to low test efficiency

The price of the integrating sphere is relatively expensive, and it needs to use software, so a computer is also necessary, so the cost of the overall equipment is relatively high

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