With the development of science and technology, the technology of LED lights has become more and more mature, making it possible to use LED lights to set up urban street lights. Compared with traditional sodium lamps, LED lamps have the characteristics of lower power consumption, higher lighting intensity, longer service life, and softer lighting.
A very important point in the design of street lamps is the uniform distribution of the illuminating light. For different lamps, different materials are required for the production of different illuminating light distributions. Although ordinary urban street lamps are far from the effect of LED street lamps in terms of energy saving, But most of them have good uniform lighting characteristics. It is not easy to achieve this effect for general LEDs. The radiation angle distribution of most LEDs is a Lambertian distribution of 110°~120°. Therefore, the ideal area of lighting illumination is concentrated in the area about 60% of the middle of the circle area with the center of the illumination area as the origin and the radius of the maximum illumination edge length, and the illumination area at the edge cannot reach the illumination level that can ensure basic traffic safety. Although it is possible to cover the road area with a lighting area that can meet the standard by increasing the number of street lights, this will not only waste peripheral lights, but also affect the possible light pollution caused by the normal metabolism of plants in the green belt. Faced with this problem, although the basic nature of LED lights cannot be changed, we can reasonably design the arrangement of LED lights to make the overall light radiation angle reach the level of ordinary street lights.
Through the research on the lighting requirements of urban traffic street lights, the street lights need uniform square illumination on the road surface. Although the general lighting method can be improved by the arc illumination light distribution method, the efficiency is not high, and the use of square illumination LED lights is expensive. At this time, the reasonable choice of light source is particularly important. Here we choose Lumiled's 120-degree divergence angle LED. This LED light emits less light on the main optical axis, and emits more light in the direction of the main optical axis at a certain angle, so as to solve the problem. The problem makes the road light distribution more uniform and reasonable.