Patent ID: 9594017
Date: 2017-03-14
CPC Classifications: G01N,G03G

Claim:
1. A reflective sensor, comprising: a light emitting section for emitting light toward a detection target object moving in a single direction; and a light receiving section for receiving regular and diffuse reflection of the light, the reflective sensor further comprising: an optical system including at least one lens section each including at least one lens which at least one lens section is disposed on an optical path of light that (i) is emitted by the light emitting section, (ii) travels to the detection target object, (iii) is reflected by the detection target object, and (iv) reaches the light receiving section, the optical system being arranged to, in a movement direction in which the detection target object is moving, collect light so that a regularly reflected light receiving area differs in position from a diffuse-reflected light receiving area by an amount within a predetermined range, the regularly reflected light receiving area being an area present between (i) the detection target object and (ii) the light emitting section and the light receiving section within which area the light emitted by the light emitting section is regularly reflected by the detection target object and is then received by the light receiving section, the diffuse-reflected light receiving area being an area present between (i) the detection target object and (ii) the light emitting section and the light receiving section within which area the light emitted by the light emitting section is diffuse-reflected by the detection target object and is then received by the light receiving section, the optical system being further arranged to, in a perpendicular direction that is perpendicular to the movement direction, refract light so that a light receiving area, which covers the regularly reflected light receiving area and the diffuse-reflected light receiving area, is wider in the perpendicular direction than in the movement direction, the at least one lens section includes (i) a single lens section disposed on either an outward portion of the optical path or a return portion of the optical path or (ii) two lens sections a first one of which is disposed on the outward portion of the optical path and a second one of which is disposed on the return portion of the optical path; and the optical system satisfies where: f′ represents a focal distance of the at least one lens section along the perpendicular direction; d represents a distance between a center of the at least one lens section and the detection target object; and a represents a distance between the center of the at least one lens section and either the light emitting section or the light receiving section.