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:
Feb. 24, 1998
Filed:
Apr. 05, 1996
Matsushita Electronics Corporation, Osaka, JP;
Abstract
This invention provides an improved photodetector with the availability of various amplifiers and with a small circuit scale. A first light-receiving element PD.sub.1 is composed of a first impurity region of the n-type formed on a p-type semiconductor substrate and a second impurity region of the p-type formed at a surface zone of the first impurity region. A second light-receiving element PD.sub.2 is composed of the semiconductor substrate and a third impurity region of the n-type. PD.sub.1 and PD.sub.2 are connected together in series. Such arrangement makes it possible to reduce the circuit scale of photodetectors if a bipolar transistor or the like is used as an amplifier means. The photosensitivity becomes higher since reverse-bias voltages are applied to PD.sub.1 and PD.sub.2. Additionally, it is possible to set a wavelength band for light to be detected, according to the area ratio of PD.sub.1 and PD.sub.2.