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. 08, 1990
Filed:
Dec. 19, 1988
Applicant:
Inventors:
John J Osborn, Corte Madera, CA (US);
Edgar M Litzaw, Corte Madera, CA (US);
Assignee:
Other;
Primary Examiner:
Int. Cl.
CPC ...
G01B / ;
U.S. Cl.
CPC ...
33 / ;
Abstract
An improved polar co-ordinate digitizer where a cord extensible from a base unit moves a cord guide to provide an angle measurement and is wrapped on a drum whose movement reflects a length measurement. Lateral pressure on the cord guide is minimized by a low mass pivot arm whose angle is sensed by optical photodetector techniques. In addition the length of the cord is also sensed by a similar photodetector both mounted for rotation about the origin axis of the polar co-ordinate system and utilizing a fixed reference photodetector all of which sense a continuously rotating disk with an index mark on it. Suitable calibration is provided for the system.