Patent · US Expired

Secret communication control apparatus

US5001750A · kind A · utility

25Cited by
1References
3Claims
0Family size

Assignee

Inventors

Key dates

Filing dateMar 7, 1990
Grant dateMar 19, 1991
Priority date
Expiry dateMar 7, 2010

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH04N2201/3335
  • WIPO fieldAudio-visual technology
  • WIPO sectorElectrical engineering

Abstract

A secret communication control apparatus used to effect secret communication with communication equipment, for example, facsimile equipment, which transmits picture information by use of public communication lines. When a communication control code that is utilized to set a communication mode is to be transmitted, the intervention of the secret communication control apparatus in the communication is suspended by switching a change-over switch, so that the main body of the local communication equipment and the remote communication equipment perform direct transmission of the communication control code therebetween without passing it through the secret communication control apparatus. It is therefore possible to transmit the signal in the minimized time, that is, in the same way as in the case of ordinary, nonsecret communication.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.