Dentate lens design for the US LED energy-saving traffic signal lamps

摘要

The purpose of the secondary optical design for light emitting diode (LED) illumination is to rearrange the luminous flux output of energy-saving LED and then achieve the desired luminous intensity distribution. Secondary optical design can be realized through refraction or reflection and it is one of the most important components in energy-saving LED illumination related technology. In this paper, a dentate lens for US traffic signal lamps was designed and the desired illumination was achieved and the demand was met perfectly. The design procedure of the dentate lens is presented. The dentate lens was formed of the array of the dentate units which has the dentate structure composed of the rectangular surfaces. Based on the US Vehicle traffic control signal heads- Lamp Emitting Diode (LED) circular signal supplement (US standards), according to the Snell law, the point coordinates of the dentate lens surface were calculated in the geometric methods and the optical surface entity was established. The results show that the dentate lens can distribute the luminous flux accurately and reasonably. The luminous flux can be saved as much as possible and the related demand of luminous intensity is met.