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. 30, 1980
Filed:
Dec. 04, 1978
Applicant:
Inventors:
Jean-Claude Rahuel, 35000 Rennes, FR;
Jean-Paul Dagnelie, 35000 Rennes, FR;
Assignee:
Other;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G08C / ;
U.S. Cl.
CPC ...
178 19 ;
Abstract
A graphics table comprises a non-conductive plate supporting two crossing layers of wires and a pen for writing on a sheet disposed on the plate. The wires are successively scanned by an electric current which creates a field to be detected by the pen. The electric current has a high frequency, for example of the order of ten megahertz, and the wires are switched at a frequency of for example one hundred kilohertz. The pen is followed by a selective amplifier of ten megahertz, by a filter, by a detector, and by a circuit for determining the time when the picked up signal passes through a peak. The invention is notably useful in a telewriting system.