JPS54108612A - Reproduction preventing system of recorded video tapes - Google Patents

Reproduction preventing system of recorded video tapes

Info

Publication number
JPS54108612A
JPS54108612A JP1616678A JP1616678A JPS54108612A JP S54108612 A JPS54108612 A JP S54108612A JP 1616678 A JP1616678 A JP 1616678A JP 1616678 A JP1616678 A JP 1616678A JP S54108612 A JPS54108612 A JP S54108612A
Authority
JP
Japan
Prior art keywords
pulses
output
recording
monostable multi
signals
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.)
Pending
Application number
JP1616678A
Other languages
Japanese (ja)
Inventor
Hiroshi Taniguchi
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.)
Panasonic Holdings Corp
Original Assignee
Matsushita Electric Industrial Co Ltd
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 Matsushita Electric Industrial Co Ltd filed Critical Matsushita Electric Industrial Co Ltd
Priority to JP1616678A priority Critical patent/JPS54108612A/en
Publication of JPS54108612A publication Critical patent/JPS54108612A/en
Pending legal-status Critical Current

Links

Classifications

    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B20/00—Signal processing not specific to the method of recording or reproducing; Circuits therefor
    • G11B20/00086—Circuits for prevention of unauthorised reproduction or copying, e.g. piracy
    • G11B20/00731—Circuits for prevention of unauthorised reproduction or copying, e.g. piracy involving a digital rights management system for enforcing a usage restriction
    • G11B20/00818—Circuits for prevention of unauthorised reproduction or copying, e.g. piracy involving a digital rights management system for enforcing a usage restriction wherein the usage restriction limits the signal quality, e.g. by low-pass filtering of audio signals or by reducing the resolution of video signals
    • G11B20/00826—Circuits for prevention of unauthorised reproduction or copying, e.g. piracy involving a digital rights management system for enforcing a usage restriction wherein the usage restriction limits the signal quality, e.g. by low-pass filtering of audio signals or by reducing the resolution of video signals wherein a spoiler signal is added to degrade the signal quality
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B20/00—Signal processing not specific to the method of recording or reproducing; Circuits therefor
    • G11B20/00086—Circuits for prevention of unauthorised reproduction or copying, e.g. piracy

Landscapes

  • Engineering & Computer Science (AREA)
  • Computer Security & Cryptography (AREA)
  • Signal Processing (AREA)
  • Multimedia (AREA)
  • Signal Processing Not Specific To The Method Of Recording And Reproducing (AREA)

Abstract

PURPOSE:To achieve the prevention of unauthorized reproduction from soft tapes by making recording of normal signals infeasible in the case of recording special signals in the soft tape and recording reproduction signals with another VTR. CONSTITUTION:The output of a synchronous separator circuit 2 forms the pulses delayed by the period about half that of horizontal synchronizing pulses in a monostable multi 4. A monostable multi 5 is driven by the trailing edge of said pulses to make the pulses of the width about half that of the horizontal synchronizing pulses. The pulses corresponding to equivalent pulse period are made at every other one field in a monostable multi 7 by way of an FF 6 by the output of a perpendicular seprator circuit 3. Further, a monostable multi 8 is driven by the trailing edge of the output of the multi 7 to make the pulses corresponding to the vertical blanking period after the equivalent pulses and at the same time the outputs of the multis 5, 8 are led to an AND 9, the output whereof is then applied to the video signal in an adder 10. This signal is further passed through a frequency modulator 11 and is then recorded in a soft tape. Thereby, recording of normal signals becomes infeasible.
JP1616678A 1978-02-14 1978-02-14 Reproduction preventing system of recorded video tapes Pending JPS54108612A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP1616678A JPS54108612A (en) 1978-02-14 1978-02-14 Reproduction preventing system of recorded video tapes

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP1616678A JPS54108612A (en) 1978-02-14 1978-02-14 Reproduction preventing system of recorded video tapes

Publications (1)

Publication Number Publication Date
JPS54108612A true JPS54108612A (en) 1979-08-25

Family

ID=11908913

Family Applications (1)

Application Number Title Priority Date Filing Date
JP1616678A Pending JPS54108612A (en) 1978-02-14 1978-02-14 Reproduction preventing system of recorded video tapes

Country Status (1)

Country Link
JP (1) JPS54108612A (en)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4488183A (en) * 1980-10-27 1984-12-11 Victor Company Of Japan, Limited Copy-proof recording medium and device for adding copy-proof interference signal
EP0297539A2 (en) * 1987-06-30 1989-01-04 Kabushiki Kaisha Toshiba Recording control apparatus
US5057947A (en) * 1988-02-10 1991-10-15 Matsushita Electric Industrial Co., Ltd. Recording and reproducing apparatus with limited digital copying
US5179452A (en) * 1987-07-29 1993-01-12 Scitec Corporation Method for producing copy protected recorded videotape having uncopyable vertical synchronizing signal partition
US5418853A (en) * 1992-07-24 1995-05-23 Sony Corporation Apparatus and method for preventing unauthorized copying of video signals

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4488183A (en) * 1980-10-27 1984-12-11 Victor Company Of Japan, Limited Copy-proof recording medium and device for adding copy-proof interference signal
EP0297539A2 (en) * 1987-06-30 1989-01-04 Kabushiki Kaisha Toshiba Recording control apparatus
US4965680A (en) * 1987-06-30 1990-10-23 Kabushiki Kaisha Toshiba Apparatus for releasing a restriction on the recording of an information signal on a recording medium
US5179452A (en) * 1987-07-29 1993-01-12 Scitec Corporation Method for producing copy protected recorded videotape having uncopyable vertical synchronizing signal partition
US5057947A (en) * 1988-02-10 1991-10-15 Matsushita Electric Industrial Co., Ltd. Recording and reproducing apparatus with limited digital copying
US5418853A (en) * 1992-07-24 1995-05-23 Sony Corporation Apparatus and method for preventing unauthorized copying of video signals
USRE36763E (en) * 1992-07-24 2000-07-04 Sony Corporation Apparatus and method for preventing unauthorized copying of video signals

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