In recent years, LED panel lights have gradually become a large indoor area due to their soft light, large light-emitting area, uniform illumination, energy saving and environmental protection.
Mainstream products for panel lighting. At present, LED panel lights are divided into two types: direct type and side type. However, the light mixing distance greatly limits the thickness of the direct-lit flat panel lamp; in contrast, the side-entry LED flat panel light uses a light guide plate to mix the light emitted by the LED lightbar on the side frame, and there is no restriction on the mixing distance, and it is thin and light. However, the light loss is large after the light passes through the light guide plate for multiple couplings, and the quality of the light guide plate is large, the production cost is high, and the process is difficult, which largely limits the development of edge-lit LED flat lights. Lai Liping et al. [4] researched and designed an LED projector, using the projector to realize a uniform light-emitting LED flat light without a light guide plate. Although the design without a light guide plate improves the light efficiency, the projector has a complicated structure. , The design accuracy is high, the process is complicated, and because the light still passes through the coupling of the projector, the light efficiency of the flat panel lamp without light guide plate still has a lot of room for improvement. In addition, side-entry panel lights are affected by multiple parameters during design, so the trial-and-error method is usually used for design. This method not only has a long design cycle, but also relies too much on the designer’s experience, which is very impractical in production design. .
The white light LED panel light has been widely praised for its unique and natural lighting effect. In view of the low light coupling efficiency of the light guide plate and the LED in the flat light, the problem of large absorption and reflection loss, this paper studies a kind of LED flat light without light guide plate , And focus on the optical design of high-efficiency projectors with uniform surface illuminance, which is used to improve the light output efficiency and illuminance uniformity of LED flat lights. Using projectors instead of light guide plates can make LED flat lights light in weight, low in production cost, and low in light loss. . The general projector research in the design of illumination optics is based on the purpose of uniform frontal illumination.
