OPTICAL SENSOR, RECORDING MEDIUM DISCRIMINATION DEVICE, AND IMAGE FORMATION DEVICE

摘要

PROBLEM TO BE SOLVED: To reduce variations in a polarization ratio on a light source of each of individual optical sensors.SOLUTION: An optical sensor 2245 comprises: an illumination system 100 emitting linear polarization in a first polarization direction toward a surface Pa of an object P from an incidence direction oblique to a normal direction of the surface; a polarization optical element 16 arranged on an optical path of light diffused and reflected by the object within an incidence surface of the object, and separating linear polarization components in a second polarization direction orthogonal to the first polarization direction; and a first photodetector 17 receiving the linear polarization component in the first polarization direction separated by the polarization optical element. The illumination system comprises a light source part 111 including a light source 116 emitting light. The light source part 111 is fixed to a housing 21 holding the illumination system, the first photodetector and the polarization optical element, via a space S1a in an emission direction of the light of the light source part.SELECTED DRAWING: Figure 2