The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 10, 1996
Filed:
May. 22, 1995
Hiroyasu Yamada, Hachioji, JP;
Casio Computer Co., Ltd., Tokyo, JP;
Abstract
A photosensor formed on an insulating substrate has a transparent top gate electrode arranged on the upper side of a semiconductor layer for photoelectric conversion and a bottom gate electrode arranged on the lower side of the semiconductor layer. If light is applied from the top gate electrode side in a state in which a bottom gate voltage V.sub.BG =+20 V is applied to the bottom gate electrode and a top gate voltage V.sub.TG =-20 V is applied to the top gate electrode, electron-hole pairs are generated in the semiconductor layer and only the holes are held in the semiconductor layer by the effect of the top gate voltage V.sub.TG =-20 V. Therefore, an n-channel is formed in the semiconductor layer and a drain current I.sub.DS flows. It was confirmed that the drain current I.sub.DS will not flow even if illumination light is applied when the bottom gate voltage V.sub.BG is set at 0 V. Therefore, the selection or non-selection state of the photosensor can be controlled by the bottom gate voltage V.sub.TG.