| 摘要 |
PURPOSE:To suppress reduction in the quantity of incident light so as to reduce a change in photocurrent due to an incident angle of the incident light, by providing a surface of a protection glass with processing which is used to diffuse the incident light on a surface of a photodetector unit. CONSTITUTION:A surface of a protection glass 2 facing a photodetector unit 11 is sandblasted as shown in a symbol 3. One part of light IN incident to a light-receiving element 1 is reflected on the surface of the protection glass, and the other part is transmitted there to attain to the sandblasted surface 3. The incident light attaining to the sandblasted surface 3 is diffused on this surface to become diffusion light DF, and the ligh DF is made incident to the light receiving element unit 11. Photoelectric conversion is performed in the photodetector unit 11 by the incident diffusion light DF, so that photocurrent is generated according to intensity of the incident light IN, that is, the intensity of the diffusion light DF. Since almost all of the diffusion light DF is made incident to the surface of the photodetector unit 11, the sufficient quantity of light can be given to the photodetector unit 11. |
