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:
Sep. 20, 2011
Filed:
Jul. 09, 2007
Applicant:
Richard M. Greene, San Rafael, CA (US);
Inventor:
Richard M. Greene, San Rafael, CA (US);
Assignee:
Other;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G09G 5/00 (2006.01);
U.S. Cl.
CPC ...
Abstract
The invention provides a graphic input device which has uniform sensitivity and is free of keystone distortion but which is lighter and less expensive to manufacture than the prior art, particularly for large drawing surfaces. It uses Fresnel optics to reduce the cost, thickness, and weight of the prism or collimator or both. Means are provided to mitigate the effects of lens flare from the Fresnel optics, minimize the thickness of the device, and to correct any remaining distortion in the camera's image using software executing on a standard computer.