Patent ID: 6919961

Claim:
An object sensor comprising: a light-emitting unit for emitting light to a transparent substrate, the transparent substrate having a detection surface on which the light emitted from the light-emitting unit and introduced into the transparent substrate is reflected; a photodetecting unit for receiving the light reflected on the detection surface; and an object sensing unit for sensing presence of an object on the detection surface by detecting a change in a photodetection signal obtained as a result of photodetection of the photodetecting unit, the change being caused by a change in a reflection condition on the detection surface which is caused by the object, wherein the light-emitting unit and the photodetecting unit are arranged with respect to the transparent substrate so that the reflected light is received by the photodetecting unit, and so that a photodetecting surface of the photodetecting unit and the detection surface form a focusing optical system, the light-emitting unit is a linear or planar light source formed by providing a plurality of light sources at either one or both of ends of a photoconductor, the focusing optical system is a focusing system of equal magnification, and the photodetecting unit includes a plurality of micro-photodetecting elements.