With the growth of LED optical efficiency, many innovat […]
With the growth of LED optical efficiency, many innovative products in the traditional lighting industry were developed rapidly. However, it is well known that Led Panel Light China products are usually directive light sources. Thus, they are still not completely fit to the whole indoor lighting market due to some parts of indoor lighting market require isotropic lighting products.
In 2008, a new optical design for LED indoor lighting product was proposed, which can provide better illumination uniformity than traditional t-bar fluorescents, and the efficiency of the illumination uniformity could be enhanced effectively. Recently, a new LED lighting product, named LED panel light, was proposed and applied in home lighting or office lighting. Current LED panel lights are usually designed by using edge-lit backlight theorem, and they contain several advantages, such as the thinner volume and the more uniform brightness of emitting surface. But they also contain some drawbacks, such as narrow lighting areas and hot spots. The narrow lighting area usually results from the directive light source of the LED package, and it also easily forms hot spots in the lighting space.
In this article, an innovative optical design approach was proposed to enhance illumination uniformity. Here, the micro-secondary lens array technique was applied for the design of the light guide surface to enhance the illumination uniformity. The micro-secondary lens array can be used to readjust the light intensity in each angle. By using the micro-secondary lens array, the candela distribution of the flat panel light can be adjusted as the batwing distribution, and therefore, its illumination uniformity in the lighting space can be efficiently improved.
The optical design of flat panel lights is usually based on the designer’s past design experience on light guide, reflector and diffuser. In this innovation, the micro-secondary lens array technique was applied for the emitting surface design of the flat panel light guide to improve the illumination uniformity. The micro-secondary lens array can be used to readjust the light intensity in each angle of the flat panel light.
The design of flat panel lights is generally based on LCD edge-lit backlight theorem. General flat panel lights can provide nearly uniform luminance, but actually, their illuminations are still not uniform enough. Therefore, engineers attempted to redesign the flat panel light by readjusting the luminous intensity in each angle. The candela distribution of the proposed flat panel light design will be similar to a batwing distribution, which can provide more uniform illumination on the floor.