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:
Feb. 15, 1994
Filed:
Dec. 04, 1992
Applicant:
Inventor:
Richard D Bates, Ann Arbor, MI (US);
Assignee:
Stanley Home Automation, Novi, MI (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G01J / ; H01J / ; G01V / ;
U.S. Cl.
CPC ...
250205 ; 2502 / ; 250221 ; 340556 ;
Abstract
A modulated light beam obstacle detector for use as a safety mechanism in an automatic closure operator which must operate in varying ambient light conditions. If the obstacle detector senses the interruption of the light beam, the motion of the door is arrested or reversed. The obstacle detector uses an auxiliary light source connected in a feedback circuit to maintain a constant background illumination on the light detector and thereby hold the light detector in conduction at all times. In this manner, the presence of the light beam can be sensed regardless of the ambient light conditions.