| 摘要 |
PROBLEM TO BE SOLVED: To greatly suppress stray light from being generated by providing a reflection member reflecting a backward emitted light from plural light sources so that a part of the emitting lights does not enter optical members and photodetectors. SOLUTION: A reflection member 35 is provided in the extended directions of the backward emitted lights 2h, 9h of light sources 2, 9. The inclined angles of surfaces 35a, 35b, of the reflection member 35 are respectively set in accordance with diffusion angles of lights emitted from the light sources 2, 9. For example, when the magnitude of the diffusion angle of the light emitted from the light source 2 is larger than that of the light emitted from the light source 9, the inclined angle θ1 of the surface 35a is formed larger than the inclined angle θ2 of the surface 35b. Thus, not only the light whose the duffusion angle is small and which is emitted from the light source 9, of course but also even the light being diffused wider and which is emitted from the light source 2 can be made so as not to enter prescribed optical paths of optical members and light receiving elements. Moreover, a manufacturing process can be simplified while greatly suppressing stray lights from being generated by making the both inclined angles θ2 together. |
