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:
Jun. 04, 2002
Filed:
May. 10, 1999
Yifeng Cui, Fremont, CA (US);
Hadi A. Akeel, Rochester Hills, MI (US);
Michael A. McNeill, Hayward, CA (US);
Fanuc America Corporation, Hoffman Estates, IL (US);
Abstract
The present invention recognizes that the limiting structures to size reduction for an optical encoder were the laser diode/photo diode package and the photodetector with amplifier package(s). The invention includes removing the discrete components from the laser diode cover package and mounting the much smaller discrete components on a base framework. The photodetector with amplifier package of the invention have an altered photodetector/amplifier geometry including shortening the leads between them. This resulted in significant size reduction of the encoder, a reduction in required gain and resulting increase in bandwidth. The entire base framework is temperature cooled by disposing two thermo-electric coolers between the base framework and an adjacent heat sink. Such positioning of the two coolers between the base framework and it's adjacent heat sink stabilizes both the laser diode's and the photo detector's outputs. In addition this novel design stabilizes the entire footprint/base of the encoder from thermal effects, whatever their origin.