To design a street light lens, first design the street light, design the height of the street light, set the distance between the light poles, set the length and width of the road to be illuminated, and determine the source type and source technical parameters, including physical size and power. The lens is to be mated with the outer casing member, so the shape is designed in combination with the machine member.
With the continuous upgrading and integration of the LED industry, the LED market in the first half of the year is relatively deserted, and the market competition is also intensifying. Most LED lighting companies have turned to online sales channels, online channel prices are chaotic, but the overall market outlook is better. At present, the investment in LED enterprise channels is large, but the revenue is not optimistic. Most of the business development of LED lighting companies has slowed down. However, the LED domestic lighting market is still growing. For foreign markets, industry experts generally believe that most of the main battlefields for export have shifted from traditional European and American developed countries to emerging markets such as Southeast Asia, South America and Africa. Due to the low production cost in Southeast Asia and close to China, the material distribution is convenient, so the gross profit of the lighting market is also surprisingly low, and the lighting companies in Southeast Asia have initially built their own factories, basically buying modules to assemble themselves without purchasing the whole lamp. Foreign trade enterprises will be a big blow. When the export is transferred to domestic sales, the competition in the domestic LED market will become more intense. In LED lighting, street lighting performance is more obvious.
Street lamps are urban development infrastructure. In order to meet the requirements of urban road lighting, traditional road lighting uses bulbs that consume more than 200 watts of mercury, which consumes electricity and has a short life. In 2009, the optical efficiency of light-emitting diodes (LEDs) on the market has exceeded 100 lm/W, which means that the power consumption of street lamps using LEDs as light sources will be greatly reduced. Due to the long life of the LED, mercury-free and energy-saving features, it is a good choice to replace the traditional LPS (low pressure sodium lamp) or MH (metal halide lamp) with LED as the light source. In recent years, LED street lamps have been adopted in many countries in the world to solve the problem of energy shortage and greenhouse gas emissions. The Chinese government is also actively promoting the replacement of more environmentally friendly LED street lamps, especially for supporting efficient solar cells. Street lighting will be on the road of green, environmental protection and energy conservation.
Most of the LEDs on the market are distributed in a Langer type, with a strong central intensity and a symmetrical circular spot distribution that cannot be directly used for road lighting. In order to meet the road lighting design standards, LED street lamps need to be designed with secondary optics to produce a rectangular, evenly distributed spot whose light distribution curve needs to be in the shape of a batwing.
At the same time, the optical design directly determines the efficiency of the LED street lamp. After the LED street lamp is equipped with a secondary lens with poor design, some of the light is lost after multiple reflections in the lens or the effective area illumination effect is not achieved. Although the secondary lens has a spot shape and uniformity, the light extraction efficiency is reduced by nearly half. LED street light optics must also avoid glare. Some LED street light lenses can also produce a rectangular, evenly distributed spot, and the light distribution curve can also be a batwing. However, since the cut-off design is not used, the outgoing light in the range of 75 to 90 degrees along the road direction is still a lot. It will cause glare to distant vehicles or pedestrians, posing a safety hazard.
The standard street lamp LED lens design should make full use of the advantage of small LED light source area, fully consider the light utilization rate, and distribute all the light emitted from the LED chip to the road surface to form a uniformity, no glare, and match The light curve is the spot of the batwing.