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. 03, 2009
Filed:
Mar. 01, 2002
Sukeyuki Shinotsuka, Sayama-shi, Saitama, JP;
Katsuhiko Takebe, Sayama-shi, Saitama, JP;
Sukeyuki Shinotsuka, Sayama-shi, Saitama, JP;
Katsuhiko Takebe, Sayama-shi, Saitama, JP;
Other;
Abstract
Disclosed is a light sensor circuit which works by producing in a photoelectric converting element a photo current proportional to a quantity of incident light falling thereon, converting the photo current into a voltage signal by using a threshold region characteristic of a transistor with a logarithmic output characteristic in a weak inverse state and producing a sensor output corresponding to the voltage signal. The light sensor circuit is provided with an initializing means for removing an electric charge remaining in a parasite capacitor of the photoelectric converting element before detecting light by the same element, thereby achieving a wide dynamic range and obtaining a sensor signal with no afterglow even if it works with a small quantity of incident light.