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:
Aug. 20, 2002
Filed:
Feb. 03, 1999
Applicant:
Inventors:
Olivier Egloff, Le Mont, CH;
Olivier Campiche, Pully, CH;
Assignee:
Logitech, Inc., Fremont, CA (US);
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H01J 4/014 ; G01D 5/34 ; G09G 5/08 ;
U.S. Cl.
CPC ...
H01J 4/014 ; G01D 5/34 ; G09G 5/08 ;
Abstract
An encoder having a movable element with a first polarized filter coupled to the movable element. A second polarized filter is either stationary, or moves differently from the first polarized filter. A photo-emitter and photodetector are arranged on opposite sides of the two polarized filters. Thus, when the polarized filters are aligned in phase, a maximum amount of light will penetrate to the photodetector. However, as they become out of phase due to movement of one of the filters, the amount of light will decrease, as a function of the amount of movement.