Patent ID: 7417217
Filing Date: 2008-08-26
Classification: G01V,G02B

Abstract:
1. A regressive reflection type photoelectric switch which receives a reflected light from a regressive reflection plate comprising: a light emitting element which irradiates laser light; a light receiving element which receives the reflected light of the laser light, which is reflected by the regressive reflection plate; a light emitting lens which collimates the laser light, which has a positive spread angle, the light emitting lens having a concave curved surface to which the laser light, which is irradiated from the light emitting element, is inputted, and a convex curved surface from which the collimated laser light is emitted; and a slit through which a portion of the laser light which is irradiated from the light emitting element to the concave curved surface of the light emitting lens passes, and which blocks the other portion of the laser light; wherein a concave curved surface is formed of a nearly spherical shape, the convex curved surface is formed of a nearly spherical shape, and area of the concave curved surface is smaller than an area of the convex curved surface.