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. 17, 2002
Filed:
Jan. 19, 2001
Yasuhiro Miwa, Omiya, JP;
Fuji Photo Optical Co., Ltd., Saitama, JP;
Abstract
A rangefinder apparatus includes an infrared emitting device (IRED) for projecting a light beam toward a target object; a position sensitive detector (PSD) for detecting light of the light beam reflected from the target object and outputting an output signal corresponding to a distance to the target object; an output circuit for charging an integrating capacitor according to the output signal of the PSD and an analog-to-digital (A/D) converter for converting a voltage of the integrating capacitor after an end of a rangefinding operation including a number of light-projecting actions by the IRED, light-detecting actions by the PSD, and integrating actions by the output circuit are repeated. Multiple rangefinding operations are carried out with a different number of repetitions, and the distance is determined according to respective values obtained by A/D conversions after the rangefinding operations. Consequently, conversion errors in A/D conversions are reduced, whereby the rangefinding accuracy is improved.