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:
Oct. 11, 1988
Filed:
Aug. 24, 1987
Applicant:
Inventor:
Samuel W Mallicoat, Portland, OR (US);
Assignee:
Microfield Graphics, Inc., Beaverton, OR (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G08C / ;
U.S. Cl.
CPC ...
178 18 ; 340706 ; 434408 ;
Abstract
A graphic input system determining position coordinate data of a mobile element on a writing surface by measuring the transit times of ultrasonic signals and an electromagnetic signal. The mobile element may comprise either a writing instrument or an eraser. The electromagnetic signal contains information that represents the color of ink used in the writing instrument and identifies the portion of the eraser in contact with the writing surface.