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Title:
SCRAMBLE SYSTEM OF TELEVISION SIGNAL
Document Type and Number:
Japanese Patent JPS60109390
Kind Code:
A
Abstract:

PURPOSE: To obtain the higher scramble effect and to obtain higher secrecy by level-shifting the horzontal blanking period in the whole period of a signal, and by inverting an optional image part by the prescribed folding back level.

CONSTITUTION: A signal S0 which is supplied from a video signal source 1 is added to an HBLK shift circuit 3 through an amplifier 2, and is also added to a synchronizing separator circuit 4. As a result, horizontal and vertical synchronizing signals are separated. A timing circuit 5 controls the operational timing of the circuit 3 based on the signal from the circuit 4, and the level shift of the horizontal blanking period is executed over the whole period of the signal S0. A level-shifted signal S1 is added to an inversion/noninversion circuit 6, and the volantary horizontal blanking period and/or the volantary image part are/is inverted by a 50IRE intermediate luminance level.


Inventors:
MATSUMOTO SHIGEO
HIRAYASU KATSUTOSHI
NAKAMICHI YUKIYA
Application Number:
JP21674983A
Publication Date:
June 14, 1985
Filing Date:
November 17, 1983
Export Citation:
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Assignee:
SONY CORP
International Classes:
H04K1/00; G06F21/10; H04N7/167; H04N7/171; (IPC1-7): H04K1/00; H04N7/167
Attorney, Agent or Firm:
Tsuchiya Masaru



 
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