LED lighting to improve the color rendering index (two)

To improve the stability of fluorescent powder, white LED is the mainstream technology, in this regard China's current technical force is weak, the short term can not be achieved a breakthrough progress, for most of China's enterprises to seek a breakthrough in this regard is difficult.

Color compensation technology is a kind of make up for the lack of a technical means of color LED color index decreased, this technology is feasible in principle, but in practice, facing the strict restriction conditions of light mixing technology, so the actual application value is not high.

White with red green and blue light mixed according to 3:6:1 theory, this theory is built on the basis of the objects we see light, this light mixing technology can be successfully applied in the white balance in LED display technology, but the application of this scheme in the lighting light mixing scheme is not much reference, this is because the human eye has an average characteristic and a habit characteristics of visible light, and these two characteristics, is also an important reason for our damage eyesight imperceptibly.

Because of the nature of light and lighting, illumination on the object, the object being reflected into the eye, so as to form the lighting process, because the objects on the various wavelengths of light absorption is different, so the color red green and blue three primary colors LED by 3:6:1 and the white light mixing technology, itself color defect the exposure to the surface, because the red green and blue is the surface absorption, reflection effect, caused by the reduction of CRI. So the light product uses three primary colors light mixing technology and production, should be in the internal surface of components or products using technical means mixing light to emit white light, rather than send three different light on the irradiated object surface mixing light, resulting in decrease of CRI.

Red green and blue three color LED color mixing technology is a kind of white lighting technology is more mature, this technology due to the larger distance between different LED caused by the light mixing distance, mixed with the mask before LED, while solving the problem of mixed light, but the light loss is a barrier for lighting in the light the development of the formation of obstacles. The next person to watch the lighting is not uniform white light; these two factors directly restrict the development of this technology.

The research on the three primary color LED hybrid technology is based on the solution of these two problems. The study found that with the decrease of the distance between the LED chip decreases exponentially light mixing distance, with the increase of three color coated color dispersing agent concentration of the light mixing effect is greatly increased, the research started, three color LED chip spacing decrease and the increase of the concentration of the three agents looking for a best balance point that is a best solution to three color light mixing, this scheme makes the three color white LED light source as possible.

At present our country in the LED packaging industry is a big country, but in innovative technology lags behind, red green and blue three color light mixing technology, using white LED phosphor coating technology, can achieve the perfect effect of white light. This is red and green and blue LED through the light mixing layer optical loss curve (curve three color dispersing agent for light).

We can see that with the increase of the concentration of color dispersing agent, optical loss increases gradually, but in the test process we found that the amount of light colloid currently used packaging technology at around 5%, the light loss and color dispersing agent in doped colloidal encapsulated by the LED at around 12%, but reached the light mixing effect well, increase the optical loss of 7% of the amount of light than the original transparent colloid loss, and achieve the light mixing effect is more perfect, from the practical application value of speaking, it is worth it.

The object of our study is the compact SMD three in one package, a plane without lens, this package requires internal RGB three chips of LED between the distance is less than the range of 1mm for low power chip.

In the field of high-power white LED chip production, and three color phosphor coating technology of powder color light mixing technology to produce the LED, for the loss of light is roughly the same, but the color chip color dispersing agent light mixing technology is more simple and effective, we should be in this technology to go farther.

LED color the means from the LED practical technology is various, this paper focuses on the practical significance of the CRI, although the production of white LED blue chip coating technology market mainstream products, but with the further development of research, with the technology, with the continuous improvement of the packaging technology, three the color of white light LED technology has made great progress, for our country in the white LED industry, has important a space for one person in the field of LED lighting.