LED as a new generation of light source, is gradually replacing the traditional energy-saving lamps market.
But the LED light source of the light form, but also with the traditional light source has a big difference, the current market circulation of LED products, in addition to a few, such as street lamps, most of them follow the traditional light source with light design, more rough and general.
So, LED optical system, how should the design?
To this end, special interview with the "2014 National Technology Invention Award" winner, Tsinghua University, Shenzhen Graduate School of Professor Qian Can Yuan. Prof. Qian Ke-yuan was awarded the award on January 9, 2015 for his contribution to the construction of "Three-dimensional free optical surface control of light behavior and its application in semiconductor lighting".
Simple and rugged LED optics design
The most important factors affecting LED optical design include light, electricity, and mechanical parts. Inside the light, in addition to the light source itself, the design of the optical system is particularly important. Because the LED is a point light source, want to meet a variety of lighting needs, must be matched with the corresponding optical system.
"From the LED lamp beads package, a light distribution is relatively simple.Packers are generally based on the cost and production point of view, more to consider the material and structure can be fully extracted from the light to improve efficiency.
The other is to do the light color to meet our requirements, including the control of color temperature, color temperature uniformity of the control. True light distribution, have to rely on secondary optics to design. "
However, enterprises in the process of designing optical systems, often used to use doctrine, slightly modified, or directly use the supplier's program.
Industry is facing the biggest problem is the lack of professional talent, and LED optical design requirements higher, the general lack of theoretical guidance, to be rational, the system design LED light distribution system of enterprises rare.
LED precision light distribution design difficult
Enterprise design ability and technology accumulation
In the industry just started the occasion, companies are busy to seize the market, promote products, light quality aspects of the things considered less. Such as a street lamp, to achieve the basic illumination requirements, there will not be too much problem, to achieve a certain degree of illumination uniformity even better, there will not be too many people to really true. As for the general bulb, lamp, there is no basic optical design at all.
Precision optical design itself is the LED lighting products to improve the need for optimization, the same a street lamp, to design well, according to the different sections of the lights themselves configuration, the corresponding optical design, which requires the lamp factory according to the actual project Situation to carry out professional optical design.
The width of the road, the height of the poles, the spacing of the lights, the high angle of the street lights, the requirements of the lens of the street lamp, the optical system.
"It is not difficult to understand why the street lights are some large enterprises. Enterprises need to configure a different mold, according to the different needs with the corresponding optical system, so as to make every road is very beautiful. Business, it is difficult to bear such a cost. "Professor Qian can be pointed out.
Lighting design and basic optical theory we all understand, but LED lighting is an emerging industry, is based on a variety of different scenarios to design, for the designer's request is relatively high, not only to understand the theory, but also have to Have practical experience, with the actual situation of the entire project to do the corresponding optical design.
"There is no standard model or theory can be universal, which is the difficulty of LED precision optical design, according to the requirements of different application scenarios designed in our design UV curing light source system, the request is the divergence angle is Small large area uniform strong irradiation, its design and the traditional similar products are very different. "Money can be said.
In addition, the general business to support a professional optical engineer is not easy.
The secondary optical design of COB
LED optical design, usually for point light sources, but COB is a surface light source, as one of the mainstream packaging trends, its light distribution design is also of concern.
COB package is not optical design, but the chip integrated together, although the COB itself light uniform, applied to the optical system but it will cause problems.
"If you need a clear edge of the uniform lighting of the scene, in fact, use the COB to do, but the effect will be poor, the edge is clearly clear is not clear, or the illumination becomes uneven.
Qian can talk about the COB light distribution requirements of the spot has become a high problem in the industry, but in some specific occasions, the COB light distribution with some optimization and improvement, so that it meets the requirements, but only Not all lamps are suitable for use with COB light sources.
"At present, we have some optimization of the optical design such as downlights and spotlights. Some of the downlights are not lenses, but they have a good lighting effect, and if the COB is used for street lamps, Lens to do a lot, otherwise there is no way to achieve the requirements of light distribution.
COB is an extended light source, how to optimize the design of the secondary optical design of COB, which is what Professor Qian Kewei is currently studying in one direction.
LED precision optical design errors
Ignore the optical design of the LED
LED as a lighting product to meet people's needs of a variety of lighting is a basic function, but the enterprise for LED optical design has not given enough attention, such as filament lamp, from the optical design point of view is relatively simple and rude, "can not Said backwards, but it was a helpless move.
Not considering the integration of lights and the environment
Street lights is a good example, glare, zebra and other phenomena exist, the reason is the design of enterprises, not fully take into account the specific sections of the environmental factors caused.
"At present, we design a new generation of LED street lamp West Tower, according to the actual reflection of the road surface to optimize the light source in the road illumination distribution, so as to achieve the premise of lighting control glare to meet the road illumination and brightness at the same time uniform and effectively eliminate the road ' Zebra "phenomenon.
Did not consider the light source and optical system adaptation problem
LED optical design, must be based on the specific light source to design, the light is not the same, the lens will have to follow the change.
"The current light source, each package factory will be different, the packaging device has changed, the optical system is not appropriate, these things should also be considered the application plant. Such technical issues related to backlight and straight down the light of the optical design Is particularly important in the process of contact, we found that some companies in this area is still limited.
"Business for LED optical design, according to market needs, or their own product positioning, such as uniformity, 80% is uniform, 90% is uniform, as long as the product can meet the market demand, the optical system is enough. Of the lighting business, there should be an optical engineer, do not have to design their own, but at least the optical design concept must understand that companies should know how to choose, how to control their own optical design requirements. "Professor Qian Can Yuan final recommendations Road.