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:
Dec. 02, 1997
Filed:
Aug. 21, 1995
Yasuji Ogawa, Otonemachi, JP;
Wacom Co., Ltd., Saitama-ken, JP;
Abstract
A digitizer for use as an input device for a computer system is provided. The digitizer is of the passive type, having a coordinate board for use as an input board which does not include any power sources or active circuit elements. In the coordinate board there is configured a plurality of resonant loop coils along each of two coordinate axes, whose resonant frequencies are mutually different. A position indicating device, exemplified by a hand-held pointer, includes an antenna coil electromagnetically coupled with any of the loop coils disposed in the coordinate board. AC power supplied to the antenna coil has a frequency which is varied to match the resonant frequencies of each of the plurality of loop coils. An AC signal generated by the induction effect due to the electromagnetic coupling is generated in the antenna coil, is outputted to a processing unit, and coordinate values of the position indicating device are calculated based on the output AC signal. Further, a method for detecting positions performed in the digitizer is described.