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:
May. 09, 1995
Shuzo Sudo, Chiba, JP;
Hideki Kitajima, Chiba, JP;
Yasuyuki Mitsuoka, Chiba, JP;
Susumu Fujita, Chiba, JP;
Seiko Instruments Inc., , JP;
Abstract
A coordinate reader comprises a coordinate detector body having at least one excitation line, at least one detection line, an exciting circuit connected to the excitation line for supplying an exciting signal, a signal processing circuit connected to the detection line for receiving an induction signal generated in the detection line and outputting a signal containing amplitude information of the induction signal, and a control circuit for receiving the signal outputted by the signal processing unit and outputting an excitation control signal to the exciting circuit. A coordinate indicator indicates position information obtained from the induction signal induced in the detection line. A phase detecting circuit detects a phase difference between the excitation signal and the induction signal generated in the detection line. By this structure, an induction signal component due to the direct electromagnetic coupling between the excitation line and the detection line is eliminated, the required accuracy in calculation of the coordinates is ensured, and the read invalid region can be further reduced.