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. 02, 1991
Filed:
Jan. 11, 1990
Applicant:
Inventors:
Alexander M Purcell, Guilford, CT (US);
David A Siefer, Orange, CT (US);
Assignee:
Summagraphics Corporation, Seymour, CT (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G08C / ;
U.S. Cl.
CPC ...
178 18 ; 340712 ; 340716 ; 362 33 ; 362 97 ;
Abstract
Digitizer tablet and digitizer tablet structure having an illuminable working surface are disclosed. A space between a top translucent layer having the working surface and a source of light is provided so as to eliminate or minimize undesirable lighting effects at the working surface. In the preferred embodiments, the space is an air gap (e.g. 0.060-0.250 inch) immediately adjacent the top translucent layer. The air gap is formed by transparent optical fibers or solid glass or acrylic rods. Back-lighted, translucent, back-lightable (without light source) and surface lighted digitizer tablet embodiments are described.