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:
Oct. 19, 1999
Filed:
Feb. 12, 1997
Koji Oka, Tamano, JP;
Masujiro Hisatani, Tamano, JP;
Hiroshi Imajo, Tamano, JP;
Toru Takehara, Tamano, JP;
Mitsui Engineering & Shipbuilding Co. Ltd., Tokyo, JP;
Abstract
A sensor detects the presence or the absence of an obstacle by radiating a laser beam to the outside of a casing through a light projecting mirror and by letting the reflected light from an obstacle enter a light receiving element through a light receiving mirror. A light projecting window with a light projecting mirror positioned and a light receiving window with a light receiving mirror are positioned in the casing with a space therebetween to prevent reflected light from directly entering the light projecting window. The mirrors are attached to a rotation shaft of a motor, or rotation shafts of motors, synchronously rotatable provided between both mirrors. The optical axis of light radiated to the outside of the casing is set to face in a higher direction than horizontal to radiate in a cone-shaped form. By comparing a received light signal from a light receiving circuit to an output signal from a circuit for a previously set threshold, which has a correlation between detected distance and light intensity, a light receiving trigger is output. The distance is calculated when a signal is greater than the threshold. The presence or the absence of an obstacle is determined by the detection of reflected light intensity. This laser obstacle detection method and sensor, which can be used on an automated guided vehicle (AGV), will not misdetect rainfall as an obstacle.