JPS5539439A - Stealthy glance preventing system for catv system - Google Patents

Stealthy glance preventing system for catv system

Info

Publication number
JPS5539439A
JPS5539439A JP11283178A JP11283178A JPS5539439A JP S5539439 A JPS5539439 A JP S5539439A JP 11283178 A JP11283178 A JP 11283178A JP 11283178 A JP11283178 A JP 11283178A JP S5539439 A JPS5539439 A JP S5539439A
Authority
JP
Japan
Prior art keywords
signal
stealthy
frequency
horizontal synchronous
preventing
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
JP11283178A
Other languages
Japanese (ja)
Other versions
JPS6156920B2 (en
Inventor
Atsushi Fukushima
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Pioneer Corp
Original Assignee
Pioneer Electronic Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Pioneer Electronic Corp filed Critical Pioneer Electronic Corp
Priority to JP11283178A priority Critical patent/JPS5539439A/en
Publication of JPS5539439A publication Critical patent/JPS5539439A/en
Publication of JPS6156920B2 publication Critical patent/JPS6156920B2/ja
Granted legal-status Critical Current

Links

Abstract

PURPOSE: To prevent the stealthy glance due to reception of the adjacent channels for the multi-channel CATV system by using the frequency of double as much as the horizontal synchronous signal to the modulation signal.
CONSTITUTION: Signal (a) generated from horizontal synchronous signal generator 1 pulse signal (b) received the 90° phase shift at phase shifter 2 are appied to video signal generators 31∼3n with application of GEN LOCK so that the output channels of converter 6 may be adjacent to each other. Both the output of the video modulator and the aural signal are modulated to the IF signals through modulators 41∼4n, and then the horizontal synchronous signal is detected at the stealthy glance preventing modulator. Then the AM modulation is applied so that the synchronous signals may be suppressed by the double frequency signal. And the horizontal synchronous signals undergo the frequency conversion through frequency converters 61∼6n and then added together at acarrier adder 7 to be sent to transmission line 8. After this, the demodulation is given at demodulation part 11 to suppress the stealthy preventing modultation component after the frequency conversion at terminal 9. Thus the adjacent channels cannot be demodulated since the phases of their synchronous signals differ from each other.
COPYRIGHT: (C)1980,JPO&Japio
JP11283178A 1978-09-13 1978-09-13 Stealthy glance preventing system for catv system Granted JPS5539439A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP11283178A JPS5539439A (en) 1978-09-13 1978-09-13 Stealthy glance preventing system for catv system

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP11283178A JPS5539439A (en) 1978-09-13 1978-09-13 Stealthy glance preventing system for catv system

Publications (2)

Publication Number Publication Date
JPS5539439A true JPS5539439A (en) 1980-03-19
JPS6156920B2 JPS6156920B2 (en) 1986-12-04

Family

ID=14596619

Family Applications (1)

Application Number Title Priority Date Filing Date
JP11283178A Granted JPS5539439A (en) 1978-09-13 1978-09-13 Stealthy glance preventing system for catv system

Country Status (1)

Country Link
JP (1) JPS5539439A (en)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH071793U (en) * 1992-12-09 1995-01-13 有限会社新津興器 Thaw container

Also Published As

Publication number Publication date
JPS6156920B2 (en) 1986-12-04

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