In the LED lighting performance evaluation
a) color space uniformity evaluation to evaluate the presence of different colors of LED lamps.
Traditional light source of a single luminous body of different characteristics, LED lamps used LED lights are composed of multiple luminous body and light, LED lamps in the luminous body between the color differences, the need to use color space uniformity evaluation to evaluate the LED lighting color The spatial distribution of the situation.
b) unlike the traditional lighting source can be a separate photometric test, photometric measurement can use the relative method, LED light source is extremely sensitive to the temperature, not suitable for LED light source separated from the lamp separately measured, photometric measurement should be used absolute method of lighting The overall photometric test.
In the LED lighting design
LED lighting in the optical system design, electrical accessories, cooling measures and structural design and traditional light source compared to the lighting is clearly different.
The optical system of the lamp is the soul of the lamp, and its purpose is to design a lighting system according to the characteristics of the selected light source to meet the specific lighting requirements. Conventional light source lighting system is usually composed of light source, lamp holder, reflector and light mask. As some LED units with 2π luminous luminosity characteristics, lighting system with the traditional light source light is very different. Specific performance characteristics are as follows:
a) LED lighting The optical system is usually composed of LED chips and lenses LED unit or LED unit array, the array is sometimes arranged in the flat aluminum substrate, it may be in the protruding or concave molding substrate, the use of lamps, or not Through the mask. Lamp manufacturers can be based on lighting needs, a number of LED units or dozens of LED units combined on the substrate, should pay attention to control the combination of LED unit light color consistency, assessment of LED lamps color space uniformity.
b) Because the photoelectric characteristics of the LED are very sensitive to the change of the PN junction temperature, the encapsulated resin will deteriorate rapidly under high temperature and strong light. The long-term optical radiation will decrease the photo-conversion rate of the phosphor and lead to the color coordinates Will be offset. LED lamp life evaluation is usually in the limit color shift under the conditions of assessment of LED lamps lumen maintenance rate.