Method and apparatus for recording and reproducing digital video signals as a function of copy protection of a tape

• US 5,907,655 A
• Filed: 09/30/1996
• Issued: 05/25/1999
• Est. Priority Date: 10/05/1995
• Status: Expired due to Term

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Oguro, Masaki
• Primary Examiner(s): Garber, Wendy
• Assistant Examiner(s): NGUYEN, LUONG TRUNG
• Application Number:
  US08/723,354
• Time in Patent Office: 967 Days
• Field of Search: 386/1, 386/94-95, 386/98, 386/109, 386/111-112, 360/60, 380/3-5, 380/19-20, 380/22
• US Class Current: 386/245
• CPC Class Codes: H04N 2005/91314 the copy protection signal being a pulse signal inserted in blanking intervals of the video signal, e.g. pseudo-AGC pulses, pseudo-sync pulses
• CPC Class Codes: H04N 2005/91328 the copy protection signal being a copy management signal, e.g. a copy generation management signal [CGMS]
• CPC Class Codes: H04N 5/78263 for recording on tracks inclined relative to the direction of movement of the tape
• CPC Class Codes: H04N 5/913 for scrambling ; for copy protection
• CPC Class Codes: H04N 9/8042 involving data reduction
• CPC Class Codes: H04N 9/8063 using time division multiplex of the PCM audio and PCM video signals
• CPC Class Codes: H04N 9/8205 involving the multiplexing of an additional signal and the colour video signal

Abstract

An apparatus records and reproduces digital video signals on a tape such that recording by another digital VTR or another analog VTR can be blocked, both through a digital interface and an analog interface, to provide a copy protection through various techniques, such as AGC or color striping. The digital recording format includes a recording area for encoded video signals and a recording area for auxiliary information configured in packs. A disturbance signal generating flag is included in an auxiliary information pack and recorded in the auxiliary information recording area. Based on the status of the flag, a disturbance signal may be inserted as a copy protection signal that is reproduced from the encoded video signals into the analog video signal.

Claims

1. A method for recording and reproducing on a recording medium a digital picture signal using a format which includes a picture recording area for storing said digital picture signal and an auxiliary recording area for auxiliary information configured in packs, said method comprising the steps of:

detecting an analog copy protection signal from an analog video signal by counting pseudo sync pulses in a horizontal synchronization period and comparing the counted pseudo sync pulses to a predetermined threshold value such that said analog copy protection signal is detected if the number of the counted pseudo sync pulses exceeds said predetermined threshold value, wherein said analog video signal includes an analog picture signal and said analog copy protection signal;

recording a disturbance signal generating flag in said auxiliary recording area in response to the detected analog copy protection signal;

converting said analog picture signal into said digital picture signal for recording in said picture recording area;

reproducing said analog picture signal from said picture recording area;

obtaining said disturbance signal generating flag from said auxiliary recording area; and

inserting a disturbance signal into said reproduced analog picture signal to disturb subsequent recording thereof, said disturbance signal being a function of said obtained disturbance signal generating flag.

2. The method according to claim 1, further comprising the step of providing another flag to indicate whether said disturbance signal is to be inserted into a vertical blanking period of said reproduced analog picture signal.

3. The method according to claim 1, wherein said disturbance signal is an automatic gain control (AGC) signal.

4. The method according to claim 1, wherein said disturbance signal is a color striping signal.

5. An apparatus for recording and reproducing on a recording medium a digital picture signal using a format which includes a picture recording area for storing said digital picture signal and an auxiliary recording area for auxiliary information configured in packs, said apparatus comprising:

means for detecting an analog copy protection signal from an analog video signal by counting pseudo sync pulses in a horizontal synchronization period and comparing the counted pseudo sync pulses to a predetermined threshold value such that said analog copy protection signal is detected if the number of the counted pseudo sync pulses exceeds said predetermined threshold value, wherein said analog video signal includes an analog picture signal and said analog copy protection signal;

means for recording a disturbance signal generating flag in said auxiliary recording area in response to the detected analog copy protection signal;

means for converting said analog picture signal into said digital picture signal for recording in said picture recording area;

means for reproducing said analog picture signal from said picture recording area;

means for obtaining said disturbance signal generating flag from said auxiliary recording area; and

means for inserting a disturbance signal into said reproduced analog picture signal to disturb subsequent recording thereof, said disturbance signal being a function of said obtained disturbance signal generating flag.

6. The apparatus according to claim 5, further comprising means for providing another flag to indicate whether said disturbance signal is to be inserted into vertical blanking period of said reproduced analog picture signal.

7. The apparatus according to claim 5, further comprising means for transferring said disturbance signal generating flag via a digital interface.

8. The apparatus according to claim 5, wherein said disturbance signal is an automatic gain control (AGC) signal.

9. The apparatus according to claim 5, wherein said disturbance signal is a color striping signal.