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:
Sep. 21, 1993
Filed:
Apr. 29, 1992
Masahiro Hirano, Saitama, JP;
Pioneer Electronic Corporation, Tokyo, JP;
Pioneer Communication Corp., Saitama, JP;
Abstract
A portable-to-portable talk system for cordless telephone. The transmitter-receiver of base unit has a control channel and a plurality of talk channels. The transmitter-receiver transmits the channel number of a vacant talk channel to a first portable unit and to a second portable unit over the control channel upon reception of a connection request from the first portable unit over the control channel. The transmitter-receiver is then switched from the control channel to the vacant talk channel after having transmitted the channel number of vacant talk channel over the control channel. Then, the receiver output of the transmitter-receiver is connected to the transmitter input. The transmitter-receiver of the portable unit has the control channel and the plurality of talk channels and transmits the connection request to the base unit over the control channel. The transmitter-receiver of portable unit is switched from the control channel to the vacant talk channel upon reception of the channel number of vacant talk channel from the base unit. A Tx/Rx selecting signal is transmitted over the vacant talk channel to other portable unit via the base unit when an operator of portable unit completes his speech. The second transmitter-receiver operates as a receiver when the Tx/Rx selecting signal is outputted from the local portable unit, and as a transmitter upon reception of the Tx/Rx selecting signal from other portable unit so that an operator is permitted to begin his speech.