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:
Jun. 03, 2008
Filed:
Dec. 07, 2005
Akio Nakajima, Katsuragi, JP;
Akio Nakajima, Katsuragi, JP;
Sharp Kabushiki Kaisha, Osaka, JP;
Abstract
A light modulation type photointerrupter includes: a light source that emits a light pulse to a transit area where an object transits; a driving circuit that drives the light source to emit the light pulse; a photoreceptor that converts the light pulse from the transit area into a pulse current and outputs the pulse current; an integrating circuit that integrates a pulse signal resulting from the pulse current and outputs a result of the integration, the integrating circuit having different time constants at a rise and at a fall of the pulse signal; and a detecting circuit that detects, based upon the output from the integrating circuit, presence or absence of the object in the transit area. The light source is driven to emit a pulse, which reduces the loss of power in the light emitter and the consumption of the current.