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:
Sep. 06, 1994
Filed:
May. 03, 1993
Kazuo Hasegawa, Furukawa, JP;
Shin Sugifune, Sendai, JP;
Alps Electric Co., Ltd., Tokyo, JP;
Abstract
A light emitting diode driving circuit for supplying a driving pulse to a light emitting diode to thereby cause the light emitting diode to intermittently emit light is disclosed which comprises a clamping circuit, a photodiode disposed in the vicinity of the light emitting diode for detecting the optical output power of the light emitting diode, an AC amplifier having its DC operating point stabilized by means of a DC feedback circuit for AC amplifying the detected output from the photodiode, a shaping circuit for shaping the output amplified signal from the AC amplifier, and a comparison circuit for comparing for voltage the output shaped signal from the shaping circuit and a reference voltage, in which the clamping voltage of the clamping circuit is controlled by the output of the comparison circuit and, thereby, the optical output power of the light emitting diode is maintained constant.
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile