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:
Jul. 07, 2009
Filed:
Jun. 30, 2005
Yuan Kong, Kirkland, WA (US);
Craig S. Ranta, Redmond, WA (US);
Tianpeng Zhao, Hefei, CN;
Hai Ming, Hefei, CN;
Jianping Xie, Hefei, CN;
Jun Xu, Hefei, CN;
Deyong He, Hefei, CN;
Yuan Kong, Kirkland, WA (US);
Craig S. Ranta, Redmond, WA (US);
Tianpeng Zhao, Hefei, CN;
Hai Ming, Hefei, CN;
Jianping Xie, Hefei, CN;
Jun Xu, Hefei, CN;
Deyong He, Hefei, CN;
Microsoft Corporation, Redmond, WA (US);
Abstract
An input device encodes motion using a laser self-mixing velocimeter. The laser beam is directed at a disk or other moving member. As light from that beam is reflected back into the emitting cavity of the laser, the beam power output fluctuates because of the self-mixing effect and generates a beat signal. The beat signal frequency is used to determine the speed of the member's motion. The direction of motion is also determined based on the beat signal. A difference frequency analog phase locked loop filters the beat signal. A zero-point control disables motion detection when the average beat signal amplitude falls below a threshold. A triangle modulator generates a triangle wave for the laser bias current, with the triangle wave frequency being a submultiple of the beat signal frequency.