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:
May. 12, 1987
Filed:
Jul. 24, 1985
Ichiya Sato, Hitachi, JP;
Takao Yoneyama, Katsuta, JP;
Masanori Tanabe, Hitachi, JP;
Kanji Kawakami, Mito, JP;
Hisao Okada, Hitachi, JP;
Soji Sasaki, Hitachi, JP;
Shigeru Inose, Tochigi, JP;
Mareo Suto, Tochigi, JP;
Hideo Uzuhashi, Tochigi, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
A tablet type coordinate input apparatus comprises a flat medium for propagating a longitudinal elastic wave, longitudinal elastic wave detecting elements disposed on part of the end-adjacent side surfaces or of the front surface of the flat medium, a longitudinal elastic wave input member having an end portion terminating in a sharp-pointed end and brought into pressure engagement at that end with any desired position on the surface of the flat medium to radiate the longitudinal elastic wave from that end, an amplifier circuit amplifying electrical signals indicative of the elastic wave detected by the detecting elements, a comparator circuit comparing the signals amplified by the amplifier circuit with a predetermined threshold voltage thereby generating delay pulse signals corresponding to the propagation times of the longitudinal elastic wave, a counter circuit counting the lengths of time elapsed from the time of radiation of the longitudinal elastic wave toward the flat medium as a result of pressure engagement of the input member therewith to the time of generation of the delay pulse signals, and a computing circuit computing the coordinates on the basis of the time signals applied from the counter circuit.