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:
Jan. 02, 2007
Filed:
Aug. 30, 2004
Hiroaki Itoh, Kashihara, JP;
Naruichi Yokogawa, Kashihara, JP;
Takao Matsui, Kashihara, JP;
Sharp Kabushiki Kaisha, Osaka, JP;
Abstract
An amplifier circuit amplifies the difference between an output voltage from a current voltage conversion circuit and a bias voltage. The current voltage conversion circuit converts a photocurrent of a photodiode which detect incoming light into a voltage. A gm-amp charges or discharges a capacity by a current corresponding to the difference between the output voltage from the amplifier circuit and a reference voltage. A field effect transistor supplies a drain current, which is controlled by voltages at the respective terminals of the capacity, to the photodiode, in order to prevent the output voltage of the amplifier circuit from being varied due to the influence of a DC photocurrent flowing in the photodiode. The gate of a field effect transistor, which is connected in parallel to a current voltage conversion resistor, has an identical voltage with the gate of the field effect transistor.