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:
Jan. 14, 1992
Filed:
Sep. 01, 1989
Hitoshi Maekawa, Owariasahi, JP;
Yuji Hirano, Owariasahi, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
Signals are transmitted using light or the like in a cordless manner between a keyboard and a controller related thereto. The keyboard transmits a signal that indicates a keycode corresponding to a key to the controller in a cordless manner, and the controller sends the keycode signal back to the keyboard. The keyboard compares the transmitted keycode with the received keycode to check whether the keycode signal is correctly transmitted to the controller. When the communication is to be carried out between a plurality of keyboards and the related controllers, a device code specific to the keyboard is attached to the keycode such that the individual keyboards can be identified.