REFLECTION TYPE DIFFUSION PLATE AND OPTICAL APPARATUS USING THE SAME

摘要

PROBLEM TO BE SOLVED: To achieve a new reflection type diffusion plate that can achieve a desired diffusion angle.SOLUTION: There is provided a reflection type diffusion plate 1A comprising a diffuse reflector including two or more types of micro-optical surfaces A1 to A4 having a negative radius of curvature, and diffusing and reflecting light beams made incident on the diffuse reflector, where: the micro-optical surfaces have positive or negative radii of curvature R and effective diameters different for each type; the radii of curvature R and effective diameters D of the micro-optical surfaces A1 to A4 are set according to the diffusion angle 2θ of diffusion light to be diffused and reflected; F values defined by F=|R|/2D of all the micro-optical surfaces are substantially the same.SELECTED DRAWING: Figure 1