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:
Feb. 20, 1990
Filed:
Nov. 10, 1988
Tsuguya Yamanami, Okegawa, JP;
Toshiaki Senda, Okegawa, JP;
Wacom Co., Ltd., Saitama, JP;
Abstract
A system for detecting the types and statuses of position designating devices is incorporated in a coordinates input apparatus having a tablet constituting a coordinates input section, a plurality of position designating devices of different types, and a position detecting circuit for driving the tablet and detecting positions at which coordinates are input by the position designating devices. The system has an antenna coil disposed around a coordinates input range of the tablet, and a tuning circuit disposed in each of the position designating devices for transmitting radio waves in response to an external signal at an individual frequency determined in accordance with the type of the corresponding position designating device. An AC signal of predetermined frequencies is applied to the antenna coil so that it transmits radio waves. The types and statuses of the position designating devices are detected by judging the condition of the position designating circuits from signals within the antenna coil while the transmission of the radio waves is suspended. With this system, the types and statuses of a plurality of position designating devices can be detected without having to connect the devices to other circuits via cords or provide them with complicated signal generating circuits and power sources such as batteries.