Led Secondary Optics For Street Light Application

Abstract: An optical sheet with a structured surface profile performing as secondary optics for LED lighting devices. The optical sheet is manufactured with a structured profile, like fresnel lens type, on its surface but leaving a flat portion in the centre of the optical sheet which does not possess the structured profile. An LED emitting a bunch of light rays which falls on the optical sheet, where central light rays pass through the central flat portion experiencing refraction. Since the light rays pass through a flat portion, the angle of incidence will be equal to the final angle of refi"action. These light rays illuminate a region (say a street) with a particular shape of illumination depending upon the shape and area of the central flat portion, and optical configuration of the lighting device which includes mounting point and orientation of the device, etc. The rest of the light rays which fail to pass through the central flat portion, fall on the structured profile of the optical sheet, undergo refraction and illuminate those areas of the required region (a street) which are less illuminated. In this way, uniformity in illumination is achieved with a variety of shape and sizes depending upon the shape and area of the central flat portion and type of profile used for optical sheet. The optical sheet may be a prismatic type/ micro structured type optical sheet.

Patent Information

Applicants

Inventors

Specification

Documents

Application Documents