Semiconductor light beam position sensor element and a position sensor

Abstract

A transparent semiconductor light beam position sensor element comprises a semiconductor layer consisting of p-, i- and n-type semiconductor layers successively bonded in junction and an electrically conductive layer disposed on either side of the semiconductive layer, at least one of the conductive layers being material transparent material, at least the other conductive layer and the semiconductor layer being provided with a multiplicity of common apertures running in the thickness direction and at least one conductive layer being provided with one pair or two pairs of electrodes of opposite polarities as disposed in its marginal regions. A position sensor utilizing the sensor element comprises a light source capable of varying the position of incidence of light on the position sensor element and a means for detecting the level of light incident on the element and holding the level constant, wherein the point of incidence of light can be identified from the photoelectric current output from one electrode of the electrode pair. A picture image input device utilizing the semiconductor light beam position sensor element further comprises a means for outputting a position signal representative of the point of incidence of light on the sensor element according to the photoelectric current output derived from the electrode pair and a means for outputting a bright dark signal representative of the intensity of light incident on the sensor element after passing or being reflected by an original according to the photoelectric current output derived from the electrode pair.