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:
Jul. 03, 1990
Filed:
Jul. 08, 1988
Kabushiki Kaisha Toshiba, Kawasaki, JP;
Abstract
A cordless telephone system which allows, in addition to outside-line communication, extension communication between wire and wireless telephone sets and also which can prevent wiretapping of communication contents during the outside-line communication. The system comprises a first switch connecting a connection unit to a wire telephone circuit, a connector connecting the wire telephone set to a connection-unit terminal of the first switch, a second switch switchingly controlled by the connection unit to supply a predetermined DC current to the connection-unit terminal of the first switch, and a DC power source for outputting the predetermined DC current. Further provided in the system, in addition to the above arrangement, are a third switch connected as inserted between the connection-unit terminal of the first switch and a voice circuit of the connection unit and a fourth switch connected as inserted between the connection-unit terminal of the first switch and the connector.