Reflection mirror for lighting apparatus

Abstract

Abstract PURPOSE:To obtain a reflection mirror having good efficiency by providing a diffuse reflecting surface having a regular wave shape on the face of a main reflection mirror so that diffusivity of a specified angle is given to the light reflected by the main reflection mirror. CONSTITUTION:If parallel rays 1, 2 fall onto a spherical convex or concave mirror having a radius (r) of curvature and diameter (d), the reflected light 1', 2' are made into the diffused light having 2theta spread if the angle between the diameter and center of curvature of the reflecting surface is designated as theta. The light made incident on each microelement is regarded to be parallel rays and the reflected light is the diffused light having 2theta spread when the distance between a light source and the reflection mirror is substantially large as compared with the diameter (d) of the spherical mirror. If the light source is at a relatively near distance and the angle between the microelement and the light source is designated as alpha, the diffusion angle of the reflected light is 2theta+alpha and if further the size of the light source cannot be neglected, the diffusion angle is 2theta+alpha+beta where the angle of the light source viewed from the reflecting surface is designated as beta.

Inventors

• 👤 Akira Arai
• 👤 荒井　昌

Bibliographic Details