JPH05268625A - Method and device for preventing dubbing - Google Patents

Abstract

PURPOSE:To effectively prevent illegal dubbing without affecting a video signal to be displayed. CONSTITUTION:A dubbing prevention signal adding device 3 applies code pattern data, which cannot exist in the natural worl, to corner parts A, B, C, and D of the over scan area placed around the part where the video signal is effectively displayed. For example, white data and black data are applied to first and second field of the cover part A respectively, and black data and white data are applied to those of the corner part B, and black and white data are applied to those of the corner part C, and white data and black data are applied to those of the corner part D. A video signal processing device 7 detects a dubbing prevention signal DP, as which these signals are applied, on a video tape 5 to stop dubbing at the time of recording. Since the dubbing prevention signal DP is applied to corner parts of the over scan area, it does not have an influence upon a normal reproduced picture at all.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for recording and reproducing a video signal, and more particularly to a video signal dubbing prevention apparatus and method for preventing illegal copying (copying or dubbing).

[0002]

2. Description of the Related Art Conventionally, various dubbing prevention methods have been tried for effectively and effectively preventing illegal dubbing in a video tape recording / reproducing apparatus or when providing a video signal. As one of the dubbing prevention methods, a copy prevention method proposed by Macrovision (hereinafter referred to as Macrovision method) is known (for example,
See Japanese Patent Laid-Open No. 63-107281). The outline of the macrovision method is described below. As shown in FIG. 12, during the blanking period of the video signal, a signal having an excessive amplitude shown by a solid line exceeding the normal amplitude level shown by a broken line is applied. The video tape recording / reproducing apparatus is provided with an automatic gain adjustment (control) circuit (AGC), but normally, during recording, a video signal is automatically adjusted in gain based on the amplitude of the broken line level as a reference. The automatic gain adjustment circuit in the tape recording / reproducing apparatus is caused to perform gain adjustment based on the above-mentioned excessive amplitude signal, and the automatic gain adjustment is intentionally changed.
As a result, the amplitude of the video signal following the over-amplitude signal is recorded with the amplitude being limited to a level lower than the original level by the automatic gain adjustment. When the dubbed video signal is played back, the display becomes dark and becomes an invisible image, so even if the image is played back and dubbed, it becomes meaningless, which contributes to the prevention of dubbing.

[0003]

In the macrovision method described above, an excessive amplitude signal is applied within a blanking period that does not affect the normal display of video signals. Therefore, the macrovision method is premised on that the above-mentioned excessive amplitude signal is used as it is applied in the video tape recording / reproducing apparatus without being removed. Therefore, a video tape recording / reproducing apparatus of a system for performing signal processing of only the input video signal by the color difference line ranking system without removing the applied blanking period signal and using it, for example, high-definition video signal processing We have encountered the problem that the macrovision method cannot be applied to the device because the above-mentioned excessive amplitude signal is not used.

A specific example of the above-mentioned video signal processing of the color difference line ranking method will be described in detail with reference to FIG. FIG. 13 (A)
Is a high-definition video signal, and a horizontal synchronization signal H-SYNC every 1H, followed by a time series of a luminance signal Y, a first signal.
The color difference signals PB and PR of the second color difference signal PR are waveform forms of the video signal input to the video tape recording apparatus. FIG.
(B) shows a horizontal synchronizing signal H in the video tape recorder.
-SYNC, other signals in the blanking period are removed, converted into a time axis compression / decompression (TCI) signal, rearranged in color difference line order, and the signal form generated in the A channel signal Ach and the B channel signal Bch is changed. Show. FIG. 13 (C)
Is a horizontal synchronization signal H-SYNC,
Burst signal BURST, index signal ID, etc. are added, and the signal waveforms of A and B channels which are FM-modulated and recorded on a video tape via a magnetic head are shown. FIG.
The horizontal synchronizing signal H-SYNC, burst signal BURST, index signal ID, etc. shown in (C) are added in the video tape recorder. At the stage shown in FIG. 13A, even if an excessive amplitude signal by the macrovision method is applied within the blanking period,
Since the signal within the blanking period is removed at the stage of processing into the signal of (B), the application of the excessive amplitude signal for the purpose of preventing dubbing is meaningless. It is an object of the present invention to provide a dubbing prevention method applicable to a video signal recording / reproducing apparatus which performs the above-mentioned color difference line ranking method signal processing.

[0005]

In order to solve the above problems, according to a first aspect of the present invention, a video used in a video signal processing apparatus for processing an applied video signal by a color difference line ranking method. In a device that provides a signal, a code signal that prohibits illegal dubbing at a video signal insertion position corresponding to a corner of an overscan area around the area where the video signal is effectively displayed in the area where the video signal is inserted There is provided a dubbing prevention device comprising a device for applying a voltage.

According to a second aspect of the present invention, illegal dubbing is performed at a position corresponding to a corner portion of an overscan region around a region where a video signal is effectively displayed in a portion where a video signal is inserted. An anti-dubbing method is provided, which comprises applying a code signal that prevents

According to a third aspect of the present invention, the video signal is inserted at a position corresponding to a corner of the overscan area around the area where the video signal is effectively displayed in the area where the video signal is inserted. There is provided a video signal recording device having a means for detecting a code signal for preventing illegal dubbing and inhibiting dubbing.

[0008]

In a video signal recording device for performing signal processing by the color difference line ranking system, for example, a video tape recording device,
Even if an excessive amplitude signal is applied during the blanking period (blanking period) of the macrovision method, it is removed and dubbing cannot be prevented. For example, as the format of the high definition video signal, the area where the video signal is effectively displayed,
An overscan area is defined around the area, and a spare area is defined outside the overscan area. The video signal is normally inserted at a position corresponding to the above-mentioned effectively displayed area, but as the format of the video signal, the video signal can be inserted at a position corresponding to the overscan area, and can also be inserted in the spare area. ..

Although the video signal inserted in the overscan area or the spare area is not displayed on the TV monitor, it is not a blanking signal, so that it is not removed in the color difference line ranking system video tape recording apparatus. If a code signal having a certain pattern capable of detecting illegal dubbing is added to the corner of the overscan area, it will not be displayed and will not affect normal reproduction. At the time of dubbing, the video signal processing device detects a code signal of a certain pattern and prohibits the dubbing.

[0010]

FIG. 1 is a block diagram showing a schematic structure of a dubbing prevention device of the present invention. Hereinafter, as an embodiment of the present invention, an example in which a video tape recording a video signal generated by the dubbing prevention device of the present invention is applied to a high-definition video tape recording / reproducing device will be described. The dubbing prevention device has a video signal generation device 1, a dubbing prevention signal addition device 3, a video tape 5 as an example of a video signal recording medium, and a high definition video signal recording / reproducing device (or a video signal processing device) 7. ..

FIG. 2 shows a video signal storage area of a high-definition signal defined by BTA. Further, FIG. 3 shows a display screen of a high-definition TV monitor. The video signal is stored in a range that covers the area 8B in FIG. 2, but the peripheral area 8B
The video signal located at is a spare and is not displayed. The shaded area 8A in FIG. 2 is the range in which the video signal is actually displayed. As shown in FIG. 3, the shaded area 8A indicates the overscan area 10B and the effective display in the overscan area 10B. Even if a video signal is present in a portion located in the overscan area 10B, the video signal is not actually displayed. For example, even if it corresponds to 1035 lines, the video signals of about 97.5 to 95% of the number of lines are actually displayed in the effective video display area 10A, and about several percent of the video signals are overscan areas 10B. It is not displayed even if it exists.

In the horizontal (horizontal) time T2 of the image displayable area 8A shown in FIG. 2, an effective video signal having a time width of 25.86 μs is displayed, and 1035 or 1080 horizontal lines are displayed in the vertical direction. is there. The spare area that is not the display target has 1125 lines in the vertical direction, and the time width T1 in the horizontal direction is 29.63 μs. In addition, the horizontal direction time ta outside the image displayable area 8A in FIG.
tb are a = 2.586 μs and b = 1.185 μ, respectively.
s. The spare area 8B of FIG. 3 is the spare area 10C of FIG.
It corresponds to.

The effective display area 10A in FIG. 3 is smaller than the overscan area 10B by about several percent. If the video signal is temporarily overscan area 10B or spare area 1
Even if it is inserted at the position of 0C (8B), it is not displayed in the effective display area 10A, but it is not removed by the video signal recording / reproducing device 7 because it is not in the blanking period, and is subject to automatic gain adjustment during recording. .. When a signal having a specific code pattern indicating the prevention of dubbing is applied to the portion located in the overscan area 10B or the spare area 10C in the dubbing prevention signal adding device 3, the video signal processing device 7 detects the code pattern signal. You can prohibit dubbing. Overscan area 10B
Since the code pattern signal for preventing dubbing applied to the display does not affect the display of the effective image display area 10A, the video tape 5 on which such a code pattern signal is recorded is recorded.
The image displayed on the effective video display area 10A is not affected even when the video signal processing device 7 is played back.

FIG. 4 shows the format of a high definition video signal. FIG. 5 is a partial view of a video tape format of a high definition video signal. In FIG. 4, the preampule PRE AM of 3H is counted from the vertical reference phase.
Following BLE, as the position corresponding to the spare area 8B,
Line 17-20 to Line 37 for the first field
-40, line 579-521 for second field
There is a spare video signal storage position on lines 599-602. The high-definition video signal displayed in the effective video display area 10A of the high-definition TV monitor screen 10 shown in FIG. A margin of about several percent is expected, and this margin is not displayed as the overscan area 10B. The symbol X in the preampule PRE AMBLE is an X signal, CW is a carrier signal, VL is a segment synchronization signal, and R is a portion where a ramp signal is set. Of the video signals, it is actually
The effective image display area 10A shown in (1) is displayed after 45 lines for the first field and after 607 lines for the second field.

The application position of the dubbing prevention signal DP in the overscan area will be described with reference to FIG. In this embodiment, of the overscan area 10B,
The dubbing prevention signal DP having the code pattern shown in FIG. 7 was applied to the corners A, B, C and D, respectively. Originally, no video signal should exist in the corner of the overscan area 10B. Even if they exist, the combination of patterns as shown in FIG. 7 is not usually considered as a video signal in the natural world. Therefore, if the code signal having the pattern as shown in FIG. 7 is used as the dubbing prevention signal DP, it can be easily identified as the dubbing prevention signal. Since the dubbing prevention signal DP is applied to the corner of the overscan area 10B, it does not affect the video signal displayed in the effective video display area 10A during reproduction.

In FIG. 8, the video tape 5 to which the dubbing prevention signal DP is applied is reproduced by the reproducing device 400,
When dubbing the reproduction signal, the dubbing prevention signal D
The apparatus structure which detects P is shown. The detector 500 detects that the signal of the code pattern shown in FIG. 7 exists at the position corresponding to the corners A, B, C, D of the overscan area 10B in the video signal reproduced by the reproducing device 400. It is detected whether or not to do. FIG. 9 shows a processing flowchart in the detection apparatus 500. Step S01: The detection device 500 detects the video signals of the corners A, B, C, D of the overscan area in the video signal reproduced by the reproduction device 400. Step S02: The detection device 500 determines that the dubbing prevention signal DP is detected when the signals at the corners A, B, C, and D of the overscan area show the pattern shown in FIG. Step S03:
When the detection device 500 determines that the dubbing prevention signal DP has been detected, it outputs a dubbing stop signal to the recording device 200. When the recording device 200 receives the stop signal, the recording device 200 stops recording the reproduced video signal.

The function of the detection device 500 shown in FIG. 8 may be incorporated in the recording device 200. 10 (A), (B)
Is a recording circuit 200 of the video signal recording / reproducing apparatus 7 incorporating a circuit for detecting such a dubbing prevention signal DP.
The circuit example of A and 200B is shown. Recording device 200A
Is the input luminance signal Y, the first color difference signal P _B , the second
3 low pass filter blocks 20 for passing low frequency signal components of the color difference signal P _R (collectively referred to as video signals), and a dubbing prevention signal for detecting the dubbing prevention signal DP from the output signals of these low pass filters. It has a detection circuit section 41. The dubbing prevention signal detection circuit unit 41 sequentially supplies the corners A, B, and
Whether or not the code pattern of the extracted signal coincides with that shown in FIG. 7 when the signal existing there is extracted (detected) at the timing corresponding to C and D and reaches the corner D of the overscan area. Determine whether or not. If the dubbing prevention signal DP is determined, the dubbing prevention signal detection circuit unit 41 outputs a recording stop signal to the recording control circuit 43 to stop the subsequent dubbing. The dubbing prevention signal detection circuit section 41 is an automatic gain adjustment circuit 2 which will be described later.
It may be provided after 1. If the dubbing prevention signal DP is not detected, signal processing in the circuit described below is performed. In the subsequent stage of the dubbing prevention signal detection circuit section 41,
Automatic gain control circuit of three systems for automatic gain control (AG
C) Block 21, A / D conversion circuit block 21A for converting a gain-controlled analog video signal into a digital video signal, a non-linear emphasis signal processing circuit 22 for performing non-linear emphasis and vertical emphasis, and a non-linear emphasis signal processing circuit A time-division multiplexing processing (TDM) encoding signal processing circuit 23 is provided which performs time-axis compression / decompression (TCI) signal processing on the output signal from 22 and shuffle processing for color difference line sequential processing. Automatic gain adjustment circuit block 2
1 indicates the A / D conversion circuit block 21 as indicated by the broken line.
You may arrange | position in the latter part of A.

Non-linear emphasis signal processing circuit 2
2 is a vertical filter circuit block 22A, 3 of two systems for the first color difference signal P _B and the second color difference signal P _R.
It is composed of a vertical non-linear emphasis circuit block 22B of a system and a horizontal non-linear emphasis circuit block 22C of three systems, and T is provided in the subsequent stage.
A DM encode signal processing circuit 23 is provided. The recording apparatus 200A is further provided with a D / A conversion circuit block 26, an emphasis circuit block 28, and an FM modulation circuit block 2 each having a two-system circuit configuration of an A channel and a B channel.
9, amplifier circuit block 30, magnetic heads 31A, 31B
have. In addition, the signal addition circuit 24 and the synchronization signal
A burst signal generation circuit 25 is provided to synchronize the two signals of the TDM encode signal processing circuit 23 with the synchronization signal.
Synchronization signal SY generated from burst signal generation circuit 25
NC and burst signal BURST are applied.

In the configuration shown in FIG. 10B, the horizontal non-linear emphasis circuit block 22C is moved to the subsequent stage of the TDM encode signal processing circuit 23.
By this arrangement change, the three-system horizontal non-linear emphasis circuit 22C shown in FIG. 10A becomes the two-system horizontal non-linear emphasis circuit 22C '.

The operation of the recording apparatus 200A or 200B shown in FIG. 10 will be described with reference to the video signal of FIG.
The luminance signal Y, the first color difference signal P _B shown in FIG.
When the second color difference signal P _R is applied to the low-pass filter 20, the TDM encode signal processing circuit 23 outputs the signal shown in FIG.
The color difference line sequential signals of the two channels A and B shown in 1 (B) are output. The horizontal synchronizing signal H-SYNC and the burst signal BURST output from the synchronizing signal / burst signal generating circuit 25 are added to the output signal from the TDM encode signal processing circuit 23. If necessary, an index signal ID (not shown) is also applied. After that, the D / A conversion circuit 26, the low-pass filter 27, the emphasis circuit 2
8, through the FM modulation circuit 29, the horizontal synchronizing signal H-
The video tape recording signal having the waveform shown in FIG. 11C, to which SYNC and the burst signal BURST are added, is recorded on the video tape 5 from the magnetic heads 31A and 31B.

The dubbing prevention signal DP can be inserted at an arbitrary position in the overscan area 10B, not in the corner bending of the overscan area described above. The code pattern shown in FIG. 7 is merely an example, and other patterns that do not exist in nature, for example, red, green, blue, white, or black in the corners A, B, C, and D of the overscan area, respectively. It is also possible to use a pattern such as. Further, in the present invention, the code pattern signal can be inserted into the video signal storage position corresponding to the spare area outside the overscan area.

In carrying out the present invention, the present invention is not limited to the above-mentioned embodiments, but various modifications can be made. In implementing the present invention, the above-described embodiments can be combined appropriately.

Although the above-described embodiments have particularly described the examples using the characteristics of the high-definition video signal, the dubbing prevention apparatus and method of the present invention are not limited to the dubbing prevention for the high-definition video signal, and the same as above. Can be applied to available video signal formats.

[0024]

As described above, according to the present invention, it is difficult to release the dubbing prevention signal, and an effective dubbing prevention device that records a video signal that is meaningless even if dubbing prevention is performed. The method can be provided. Further, since the dubbing prevention apparatus and method of the present invention do not affect the video signal itself that should be effectively displayed, even if the dubbing prevention measures of the present invention are taken, the displayed image itself is not affected. ..

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a dubbing prevention device of the present invention.

FIG. 2 is a plan view of a TV monitor screen for explaining an effective video signal portion of a high-definition signal defined by BTA.

FIG. 3 is a plan view of a TV monitor screen for explaining an effective display portion of the TV monitor.

FIG. 4 is a diagram showing a format of a high-definition video signal and its waveform applied in the dubbing prevention apparatus of the present invention.

FIG. 5 is a diagram showing a format of a high definition video signal.

FIG. 6 is a diagram showing an application position of a dubbing signal in the dubbing prevention device of the present invention.

7 is a diagram showing an example of a code pattern of a dubbing signal applied to the position shown in FIG.

FIG. 8 is a diagram showing a configuration of a video signal processing device which detects the dubbing prevention signal shown in FIG. 7 and prohibits illegal dubbing.

9 is a flowchart showing a dubbing prevention signal detection process in the detection apparatus shown in FIG.

FIG. 10 is a circuit configuration diagram of a video signal recording device for recording a video signal from a video tape by the dubbing prevention device of the present invention.

11 is a waveform diagram showing a recording operation process of a video signal to which a dubbing prevention signal according to an embodiment of the present invention is applied in the video signal recording device shown in FIG.

FIG. 12 is a diagram showing a waveform of a conventional dubbing prevention signal.

FIG. 13 is a diagram showing a recording process in a video signal processing device to which the dubbing prevention device of the present invention is applied.

[Explanation of symbols]

1 ··· Video signal generator, 3 · · Dubbing prevention signal adding device, 5 · · Video tape, 7 · · Video signal processing device (video signal recording / playback device), 8, 10 · · HD TV monitor screen, 10A ... Effective video display area, 10B ... Overscan area, 20 ... Low-pass filter block, 21 ... Automatic gain adjustment circuit block, 21A ... A / D conversion circuit block, 22 ... Non-linear emphasis signal processing circuit , 22A ... Vertical filter circuit block, 22B ... Vertical non-linear emphasis circuit block, 22C ... Horizontal non-linear emphasis circuit block, 23 ... TDM encode signal processing circuit, 24 ... Signal adding circuit, 25 ... .Synchronization signal / burst signal generation circuit, 26 ... D / A conversion circuit block , 27 ... Low-pass filter block, 28 ... Emphasis circuit block, 29 ... FM modulation circuit block, 31A, 31B ... Magnetic head, 41 ... Dubbing prevention signal detection circuit section, 43 ... Recording control circuit, 200A , 200B ··· Recording device, 400 ··· Reproducing device, 500 ··· Detecting device

Claims (3)

[Claims] 1. An apparatus for providing a video signal for use in a video signal processing apparatus for processing an applied video signal in a color difference line order method, wherein the video signal in a portion where the video signal is inserted is effectively displayed. A dubbing prevention apparatus comprising a device for applying a code signal for prohibiting illegal dubbing to a video signal insertion position corresponding to a corner portion of an overscan region around the region to be dubbed. 2. A code signal for preventing illegal dubbing is applied to a position corresponding to a corner of an overscan region around a region where a video signal is effectively displayed in a portion where a video signal is inserted. Characteristic dubbing prevention method. 3. A code signal for preventing illegal dubbing, which is inserted at a position corresponding to a corner of an overscan region around a region where a video signal is effectively displayed, in a portion where a video signal is inserted is detected. A video signal recording apparatus having means for inhibiting dubbing.