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:
Apr. 06, 1993
Filed:
Jul. 22, 1991
Won B Kim, Seoul, KR;
Hyundai Electronics Industries Co., Ltd., Kyoungkido, KR;
Abstract
A radio-telephone system employing a manner of changing a channel and a privacy digital code and interstoring them between by wireless and a method of changing the privacy digital code. The radio-telephone system comprises a stationary apparatus 100 and a portable apparatus 200. The stationary apparatus 100 includes a base MPU 410 containing a ROM, a charging power supply and sensing circuit 450, a transmitting and receiving PLL circuit 420, a duplex radio transmitting and receiving unit 430, a line connecting circuit 460 and an antenna A. The portable apparatus 200 includes a hand MPU 610 containing a RAM, a transmitting and receiving PLL circuit 620, a duplex radio transmitting and receiving unit 630, a charging circuit 680 and an antenna A'. The method of changing the privacy digital code is performed by using the radio-telephone system. Therefore, in accordance with the present invention, the selection of the talk channel having no crosstalk by the system software is enabled. In addition, first in confirmation of a identification code in decision of the talk channel, a misconnection between the stationary and portable apparatus in the course of a talker's talking over the telephone can be prevented.