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:
Mar. 23, 1993
Filed:
Dec. 13, 1991
Tamayo Hiroki, Ebina, JP;
Hidetoshi Nojiri, Hadano, JP;
Canon Kabushiki Kaisha, Tokyo, JP;
Abstract
A field effect type photo-detector comprises a semiconductor buffer layer arranged on a substrate. A semiconductor activation layer is arranged on that buffer layer, and a source electrode, a drain electrode and a gate electrode are arranged on the activation layer. A depletion layer for controlling a current flow between the source electrode and the drain electrode is created in the activation layer by applying a voltage to the gate electrode. When light irradiates the activation layer, the depletion layer changes. The buffer layer has a wider band gap than that of the activation layer and has an energy gap which serves as a barrier to carriers. The buffer layer has a sufficiently wide band gap to prevent the absorption of light having an equal wavelength to that of the light irradiated to the activation layer.