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:
May. 04, 1993
Filed:
Apr. 29, 1992
Applicant:
Inventor:
Yoshinori Narutaki, Machida, JP;
Assignee:
Optec Co. Ltd., Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G01C / ;
U.S. Cl.
CPC ...
356-4 ; 356-5 ;
Abstract
An electro-optical distance meter has a light-emitting element that is directed through a shutter to a target and returned from the target to a photodetector. Internal and external optical paths are continuously switched by the shutter with a predetermined time ratio. The internal optical path is used for calibrating the distance being measured. The meter reduces the measurement time and enhances accuracy. In one form, the shutter comprises a disc having a C-shaped opening with an index thereon for providing a reference signal. In another form, the shutter comprises a liquid crystal switch.