Analysis of how to improve the reliability of LED lighting

With the blue and white light emitting diode (LED) in 1990, heavily towards the practical stage,whether it is carried out by using LED full color display, or is in the attached great importance toenergy conservation issues in recent years the public show, LED spread to the intelligent mobile phone, personal computer (PC), TV, lighting, backlighting white goods or traffic signaldiversification of product application more and more widespread. In order to meet the market demand, the industry for a variety of products, including can achieve high color rendering and high reliability of the lighting with LED, with PICOLED as the small thin LED of representative products,and automotive into customized color LED considerable R & D resources.

Lighting with white LED output is growing rapidly

By rising world energy saving trend, triggered by the northeastern Japan earthquake awareness of energy conservation, the Japanese market demand for lighting with white LED increased,promoting LED lighting market value is continuously rapid growth, however, to make the lighting source completely from the traditional incandescent lamp illumination modes is converted to LEDlighting, there are, in the product properties are still some problems to be solved in which theindustry research and development focus, especially in the LED lamp high color rendering and high reliability, the following will be separately employment in high Ra value technology and luminous efficiency do share.

The balance of high Ra value and the luminous efficiency

The average color evaluation index (Ra) is a light source to make the object performance orreproduce a true color index, a higher index, represents the color reproducibility is better (the light of the sun, 100 for Ra), the market for lighting with white LED can provide both high luminousefficiency and high color rendering (Ra = 80) however, the luminous efficiency and Ra valuesbetween the two there are benefits (Trade-off) characteristics. On the market for the luminous efficiency have higher requirements, therefore, currently on the market for Ra - 70 high luminous efficiency of LED.

Package structure of the general white light LED lamp is the blue light LED chip mounted on the substrate, and then to resin containing fluorescent body package. In the luminous color of the LED element (blue) light color and fluorescent substance (yellow, red or green) after mixing, will form awhite light.

From the light emitting efficiency point of view, the general mostly Blu ray + yellow light to form white light, but this will cause a red poor reproducibility, therefore not suitable for lighting purposes.The general solution is used to increase red component, thereby improving the reproducibility of the red, but so will lead to the problem of non ideal luminous efficiency.

For both high luminous efficiency and high Ra value, the industry will be the fluorescent bodyefficiently configured on the internal packaging, to satisfy both sides of technology as a solution,has successfully developed a Ra greater than 80 and high light-emitting efficiency products. This series of products in both Ra or R9 (red) index on the performance are very good, and the Ravalues of other brands of products are the same in comparison, the series products of R9 is high,the reproducibility is good red. With this breakthrough, LED lamp can not only decrease the coloruneven, but also because of should be more detailed chroma level.