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:
Jun. 25, 1991
Filed:
Feb. 27, 1989
Takakazu Tanaka, Fukuoka, JP;
Yuji Hirai, Fukuoka, JP;
Abstract
A radio communication apparatus includes a device for sequentially discriminating whether or not different frequency channels are open or occupied and generating channel-condition signals representative thereof during each of cycles of a channel scan. The channel-condition signals correspond to the channels respectively. A device holds the channel-condition signals and thereafter outputs the channel-condition signals. A device detects a variation between a current channel-condition signal and a preceding channel-condition signal in respect of each of the channels. The current channel-condition signal is currently generated by the discriminating device. The preceding channel-condition signal is outputted from the holding device. A device detects whether or not a given identification signal is present in the channel where the detected variation occurs.