Title:
TELEVISION SIGNAL SCRAMBLING SYSTEM
Document Type and Number:
Japanese Patent JPS62236291
Kind Code:
A
Abstract:
PURPOSE:To attain an effective scrambling of a video and voice by inversing the video signal spectrum in the television signal band, and carrying the result together with a voice signal. CONSTITUTION:In the video inversion system, a television signal is mixed with a signal fosc-1 from the first local oscillator 14 in the first mixer 8, and inputted to the first intermediate frequency filter 9. In the filter 9, only the video components in a difference signal generated in the lower side of the signal fosc-1 is extracted, and inputted to the second mixer 10. On the other hand, in a voice extraction system, a video signal is sufficiently attenuated via a voice extraction filter 16, a sound carrier wave is extracted, video components are eliminated from the wave by a voice output filter 18, and the wave is sup plied to a mixer 13. As a result, the intercarrier relation between the video signal carrier wave and the sound signal carrier wave is broken. Accordingly,to display a picture only by normal manual tuning operation at the terminal is made impossible unless the scrambling is executed in the inverses system.
Inventors:
NAKAMARU NORIKANE
IMAZAKI KENJI
IMAZAKI KENJI
Application Number:
JP8163686A
Publication Date:
October 16, 1987
Filing Date:
April 08, 1986
Export Citation:
Assignee:
PIONEER ELECTRONIC CORP
International Classes:
G06F21/10; H04N7/167; H04N7/169; (IPC1-7): H04N7/167
Attorney, Agent or Firm:
Nobujun Kobashi