JP2004007672A - Video signal processing apparatus and method, and recording medium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To selectively add a copy protection signal to an analog video signal for reducing the degradation of the image reproduced on a monitor as much as possible. <P>SOLUTION: A normal burst signal SB1 from a signal generator 31, and a first copy protection signal SB2 or a second copy protection signal SB3 selected by a switcher 36 is selected by a switcher 35. Subsequently, the signal is inputted to an adder 27, and then added to a reproduced color signal by the adder 27. The signal SB2 is a signal in which a pseudo burst signal is inserted into one part of a burst period, and the signal SB3 is a signal in which a pseudo burst signal is inserted into the whole of a burst period. Therefore, the positions in which a pseudo signal is inserted are different from each other in signals SB2 and SB3. A user controls the switcher 36 to select a copy protection signal which reduces image degradation as much as possible for an image displayed on a television monitor. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a video tape recorder for recording an analog video signal from a video disk, a digital VCR, a digital broadcast receiving device, and the like, and a video signal processing device applied to a television receiver for displaying a reproduced output thereof, The present invention relates to a signal processing method and a recording medium.
[0002]
[Prior art]
With the development of digital technology, high-quality video signal sources are easily available even at home. For example, not only pre-recorded tapes (soft tapes) but also digital broadcasting terminals, DVDs (digital video discs), and the like provide users with high-quality video signals. Digital VCRs (video cassette tape recorders) are gradually becoming popular for home use. At present, analog VCRs have become much more popular. As described above, a provider of a high-quality video signal has to pay great attention to the restriction of copying by an analog VCR from the viewpoint of copyright protection.
[0003]
In the analog VCR, several copy restriction methods have already been considered. For example, an AGC pulse method and a color stripe method by Macrovision are known. The AGC pulse method limits a pulse by inserting a pulse having a level larger than a normal AGC reference level into an AGC reference level detection section of a video signal. That is, a pseudo SYNC pulse is inserted in a part of the V (vertical) blanking period of the video signal. There are many analog video tape recorders (analog VCRs for home use) in which AGC is performed using a horizontal synchronization pulse and a pedestal level (back porch). Therefore, if a pseudo SYNC pulse having a portion corresponding to the back porch and having a larger amplitude than a normal horizontal synchronization pulse is inserted, the AGC circuit determines the amplitude of the pseudo SYNC pulse as the reference level and Is applied. As a result, since the AGC level is detected as the level of the pseudo SYNC pulse, SYNC cannot be detected and normal reproduction cannot be performed. On the other hand, the television monitor can display a reproduced image normally because the AGC system is different.
[0004]
[Problems to be solved by the invention]
However, this AGC pulse method has a problem that it is effective only for a part of the VHS system video tape recorder. For example, the VCR of the β system, the 8 mm VCR, and the VHS system have no effect on those having a long AGC time constant.
[0005]
Therefore, as another copy restriction method, a color stripe method described below has been proposed. The color stripe method is a method of inverting the phase of a burst signal for a reproduced video signal by, for example, 2 to 4 lines every 20 lines. When the reproduced video signal whose phase of the burst signal is inverted is recorded by another home analog VCR, an APC (automatic phase control circuit) of the analog VCR uses the burst signal whose phase is inverted as an original burst signal. Since the line is used, the color of the line is inverted and reproduced. Therefore, when the recorded video signal is reproduced, a band whose color is inverted is displayed on the screen.
[0006]
On the other hand, in a general television receiver, the time constant of a PLL (APC) that forms a carrier for demodulating a color signal has a long time constant. Does not come out. However, depending on the model, a PLL having a short time constant may be used, and in this case, there is a problem that a band whose color is inverted is generated on the screen.
[0007]
SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a video signal processing apparatus, a video signal processing method, and a recording medium in which copy restriction is surely performed and image quality of a reproduced image is less likely to deteriorate.
[0008]
[Means for Solving the Problems]
In order to solve the above-mentioned problem, the present invention receives a digital video signal reproduced from a recording medium or an analog video signal for analog output corresponding to a received digital video signal, and adds a signal for recording restriction. A video signal processing device for outputting
Means for separating a control signal included in the reproduced digital video signal or the received digital video signal and indicating whether or not to perform recording restriction;
In the case where recording is restricted in response to the separated control signal, a signal adding unit that adds a recording restriction signal to the analog video signal is provided,
The recording restriction signal is a signal added to at least one of the sections on the front side and the rear side of the color burst signal, and is a signal having a phase different from the original phase of the color burst signal. It is a video signal processing device.
[0009]
The present invention relates to a video signal processing method for receiving a digital video signal reproduced from a recording medium or an analog video signal for analog output corresponding to a received digital video signal, adding a signal for recording restriction, and outputting the signal. Separating a control signal included in the reproduced digital video signal or the received digital video signal and indicating whether or not to perform recording restriction;
When recording is restricted in response to the separated control signal, a signal adding step of adding a recording restriction signal to the analog video signal is included.
The recording restriction signal is a signal added to at least one of the sections on the front side and the rear side of the color burst signal, and is a signal having a phase different from the original phase of the color burst signal. This is a video signal processing method.
[0010]
Further, the present invention provides a video signal reproducing device that detects the state of a control signal provided on a recording medium and controls the addition of a recording restriction signal that restricts recording of an analog video signal based on the detection output. A recording medium for supporting a video signal reproducing method,
The recording medium has a pack structure for storing a control signal for instructing whether to add a recording restriction signal for restricting recording of the form of the analog video signal to the pack to the analog video signal,
In the case where the recording of the aspect of the analog video signal is restricted, when the reproducing apparatus reproduces the digital video signal and outputs the digital video signal as an analog video signal, at least one of the front side and the rear side of the color burst signal for recording restriction. The control signal indicates that a signal added to a part of the section and having a phase different from the original phase of the color burst signal is added to the analog video signal as a recording restriction signal. Is a recording medium.
[0011]
Still further, the present invention provides a video signal reproducing apparatus or a video signal detecting a state of a control signal disposed on a recording medium and generating a recording restriction signal for restricting recording of an aspect of an analog video signal based on the detection output. A recording medium for supporting a signal reproducing method,
The recording medium has a sector structure for storing a control signal for instructing whether to generate a recording restriction signal for restricting recording of an aspect of an analog video signal with respect to a header added to the sector,
In the case where the recording of the aspect of the analog video signal is restricted, when the reproducing apparatus reproduces the digital video signal and outputs the digital video signal as an analog video signal, at least one of the front side and the rear side of the color burst signal for recording restriction. The control signal indicates that a signal added to a part of the section and having a phase different from the original phase of the color burst signal is added to the analog video signal as a recording restriction signal. Is a recording medium.
[0012]
According to the present invention, a signal having a phase different from the original phase of the color burst signal is added to the analog video signal as a recording restriction signal in at least one of the front and rear portions of the color burst signal of the video signal. . There is no problem with a medium in which the analog video signal to which the recording restriction signal has been added is directly reproduced by a television receiver, but the recording restriction signal is extended by low-frequency conversion performed when recording a video signal in an analog system. Therefore, when a signal recorded in such a manner is reproduced, an image failure occurs, thereby making it possible to restrict recording.
[0013]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an embodiment of the present invention will be described. To facilitate understanding of the present invention, an application example of copy restriction will be described with reference to FIG. FIG. 1 shows an example in which an analog video signal reproduced by a digital VCR 2 is recorded by an analog VCR 1. When the cassette tape reproduced by the digital VCR 2 is, for example, a pre-recorded tape, and control information (referred to as CGMS (Copy Generation Management System)) relating to copy generation restrictions recorded in the tape indicates copy prohibition. Then, it is necessary to prohibit recording by the analog VCR1.
[0014]
FIG. 1B shows an example in which a reproduced analog video signal from the DVD player 3 is recorded by the analog VCR 1. Even in this case, when the copy prohibition is instructed by the CGMS recorded on the DVD, it is necessary to prohibit the recording by the analog VCR1. Further, FIG. 1C is an example in which a program received by an IRD (Integrated Receiver Decoder) (or a set-top box) 4 for receiving a digital broadcast is recorded by a digital VCR 5, and the recorded content is recorded by an analog VCR 1. . Generally, it is often permitted that the digital VCR 5 records a digital broadcast program once as a digital signal or an analog signal. However, copying of the recorded contents by the analog VCR 1 is restricted. Of course, the copying of the video signal from the IRD 4 to the analog VCR 1 may be prohibited.
[0015]
The present invention makes it possible to prohibit copying by the analog VCR 1 and to display analog video signals from the digital VCR 2, the DVD player 3, and the digital VCR 5 on the monitor device without any trouble in the case illustrated in FIG. Things. FIG. 2 shows an embodiment of the present invention applied to a case where an analog video signal reproduced by the DVD player 3 is output as in the example of FIG. 1B.
[0016]
A digital signal compressed and encoded by MPEG or the like is read from the DVD 6 by the optical pickup 7. The reproduction signal of the optical pickup 7 is supplied to an error processing circuit 9 via a preamplifier, a waveform shaping and decoding circuit 8. The error processing circuit 9 decodes the error correction code and corrects the error. The output of the error processing circuit 9 is supplied to a demultiplexer 10. The demultiplexer 10 separates video data, audio data, and control digital data from the reproduced signal.
[0017]
The video data is supplied to the video decoder 11. The video decoder 11 performs processing such as decoding of compression encoding and conversion to an analog video signal, and supplies an analog video signal to the output unit 14. The output unit 14 is one to which the present invention is applied, and the details thereof will be described later. An analog video signal to which a copy protection signal is selectively added is output from the output unit 14 to the output terminal 16. The audio data undergoes processing such as decoding of compression encoding and conversion to an analog audio signal in the audio decoder 12, and an analog audio signal is obtained at an output terminal 17. The digital data decoder 13 separates and decodes the control digital data recorded on the DVD 6. The decoded output is supplied to the microcomputer 15. CGMS is included in the control digital data.
[0018]
The microcomputer 15 generates a control signal indicating addition of a signal for copy protection and a type of the added signal in accordance with CGMS recorded in advance on the DVD 6 and an instruction input from outside by a user. This control signal is provided to the output unit 14. The output unit 14 is provided inside the DVD player.
[0019]
FIG. 3 shows an example of the configuration of the output unit 14. The reproduced video signal from the video decoder 11 is supplied to the output unit 14 as, for example, an analog component signal. A luminance signal Y and color difference signals RY and BY are supplied to input terminals indicated by 21, 22, and 23, respectively. The luminance signal Y is taken out to the output terminal 16Y via the adders 24 and 25. The color difference signal is supplied to the color encoder 26, and the color encoder 26 forms a carrier color signal subjected to quadrature two-phase modulation. This carrier chrominance signal is extracted via the adder 27 to the output terminal 16C.
[0020]
In the adder 24, the normal composite synchronizing signal generated by the synchronizing signal generator 28 is added to the luminance signal Y. The adder 25 receives the AGC pulse from the AGC pulse generator 29 and adds the AGC pulse to the luminance signal Y. The AGC pulse generator 29 generates one of a normal level AGC pulse and a high level AGC pulse for copy prohibition. The selection is made by a control signal from the microcomputer 15.
[0021]
In the adder 27, a color burst signal is added. When copying is permitted, the normal color burst signal SB1 generated by the signal generator 31 is added. When copying is prohibited, the first copy protection signal signal SB2 generated by the signal generator 32 or the second copy protection signal signal SB3 generated by the signal generator 33 is added. For selecting these signals, a switcher 35 controlled by the microcomputer 15 and a switcher 36 controlled by the user are provided.
[0022]
The switcher 36 selectively supplies one of the copy protection signal signals SB2 and SB3 supplied to its input terminals c and d to the input terminal b of the switcher 35 in accordance with a user selection. The switcher 35 supplies the color burst signal SB1 from the signal generator 31 to one input terminal a, and supplies the output signal of the switcher 36 to the other input terminal b. The signal selected by the switcher 35 according to the user's selection is supplied to the adder 27.
[0023]
The switcher 35 is controlled by a control signal generated by the microcomputer 15 based on a video signal reproduced from the DVD 6 and a result of decoding a CGMS accompanying the video signal. That is, when the CGMS instructs the prohibition of the analog copy, the switcher 35 selects the input terminal b and supplies the copy protection signal signal SB2 or SB3 to the adder 27. When the user supplies an analog video signal reproduced by the DVD player to the television monitor, the user inputs a key to select which of the copy protection signal signals SB2 and SB3 to be added, based on the quality of the displayed image. , Via a user interface such as button input. The switcher 36 is controlled based on the instruction. Therefore, when the video signals taken out to the output terminals 16Y and 16C are recorded by the analog VCR, the recording can be prohibited. When the video signals are supplied to the television monitor, a high quality reproduced image is obtained. Can be seen.
[0024]
FIG. 4A shows an example of a CGMS recorded in advance together with a digital video signal recorded on the DVD 6. As shown in FIG. 4A, CGMS is defined as follows.
00: copy possible 01: unused 10: copy 1 generation possible 11: copy impossible
In the case where the copy in the CGMS specifies only the digital copy restriction, a flag indicating whether or not analog copying is possible, that is, a trigger bit for instructing generation of an analog copy restriction signal may be separately specified. FIG. 4B is an example of this. If the trigger bit is “0”, it is instructed not to generate an analog copy restriction signal. If this bit is “1”, the analog copy restriction signal is generated. Is indicated. In this case, the restriction information of the analog copy is constituted by a total of three bits of the CGMS and the trigger bit. However, both analog and digital may be defined by the CGMS, or two bits (01) not used by the CGMS may be used to configure the restriction information of copying by the analog VCR with two bits.
[0026]
Various forms are possible for actually recording such copy restriction information on a recording medium. In the case of a digital VCR, the data structure shown in FIGS. 5 and 6 is adopted. FIG. 5 shows the configuration of VAUX (video auxiliary data), which is a pack having a pack header of (01100001) (61h) (h represents hexadecimal notation).
[0027]
In this pack, CGMS is recorded as the upper two bits of PC1. The definition of this CGMS is the same as that shown in FIG. 4A, for example. The copy source in the PC 1 is defined as follows.
00: Copy by analog input 01: Copy by digital input 10: Reserved 11: No information
The definition of the copy generation in PC1 is shown below.
00: first generation 01: second generation 10: third generation 11: fourth generation
FIG. 6 shows an example of auxiliary data (AAUX data) relating to an audio signal in a digital VCR. The header of this pack is (0101001) (51h). In the pack PC1, information on copy generation restriction is recorded in the same configuration as the VAUX. If the CGMS attached to the input video signal can be copied for one generation and the input video signal is recorded, the CGMS on the tape is rewritten to copy prohibited.
[0030]
In the case of a DVD according to an embodiment of the present invention, although not shown, the recording data has a break such as a sector, and a sync signal and a header are added to the head of the break. Information for copy restriction is recorded in this header.
[0031]
Next, a signal added for copy restriction in one embodiment of the present invention will be described. First, the first copy protection signal, which is a copy prohibition signal generated by the signal generator 32, will be described.
[0032]
In an analog home-use VCR, a chrominance subcarrier having a frequency of 3.58 MHz (in the case of the NTSC system) is down-converted into a low-pass conversion color signal having a predetermined center frequency of 600 to 700 KHz. . Then, the low-frequency conversion color signal and the luminance signal are frequency-multiplexed and recorded on a magnetic tape. As described above, in a home analog VCR, a color signal is band-limited very narrowly compared to a television receiver or the like, and is recorded on a magnetic tape.
[0033]
Therefore, when reproduced, the color burst signal included in the recorded video signal has a property of being extended before and after the original signal before recording on the time axis due to band limitation when reproduced. FIG. 7 shows a color burst signal SB1 in the original signal and the signal reproduced by the VCR. When the original signal SB1 of the color burst signal arranged after the horizontal synchronizing signal h shown in FIG. 7A is recorded on the magnetic tape and reproduced, the color burst signal expands back and forth on the time axis as shown in FIG. 7B. Is done.
[0034]
The first copy prevention signal signal SB2 for copy inhibition is a signal for utilizing this property to achieve copy protection by the copy protection signal addition method. An example of the first copy protection signal signal SB2 will be described with reference to FIG. FIG. 8A shows a normal color burst signal SB1. On the other hand, FIG. 8B shows an example in which a pseudo-burst signal b (shown by oblique lines) whose phase is inverted is inserted after the normal color burst signal a. FIG. 8C is an example of the copy protection signal SB2 in which the pseudo burst signal b is inserted before the original signal a. FIG. 8D shows an example of the copy protection signal SB2 in which the pseudo burst signals b and c are inserted before and after the original signal a. For example, when the pseudo burst signals b and c are inserted before and after the original signal a with respect to nine color burst signals, two waves are respectively inserted before and after the original signal a.
[0035]
When the video signal to which the copy protection signal SB2 including the pseudo burst signals b and c is added by the adder 27 is recorded and reproduced as described above, the color burst signal is converted into the color burst signal according to the above-described nature of the forward and backward expansion on the time axis. The width of the pseudo burst signals b and c added before and after the original signal a increases. This is shown in FIG. That is, in the copy protection signal SB2 in a state where the pseudo burst signals b and c shown in FIG. 9A are inserted, the pseudo burst signals b and c pass through recording / reproduction on a magnetic tape, and are indicated by SB2 'in FIG. 9B. As such, the width is extended back and forth.
[0036]
When the video signal including the copy prevention signal SB2 'having the increased width is reproduced by, for example, a VCR, the PLL cannot follow the color synchronizing circuit of the VCR, causing image degradation, thereby preventing copy. Can be. Needless to say, even when this video signal is recorded / reproduced by another VCR, a normal image cannot be obtained.
[0037]
On the other hand, the video signal shown in FIG. 9A including the copy protection signal SB2 in which the pseudo burst signals b and c are inserted before and after the color burst signal is detected and used as a substantially regular color burst signal in the television monitor. You. Therefore, in this case, the image does not deteriorate. However, image quality may deteriorate depending on the characteristics of the APC of the television monitor. Therefore, the user generates a control signal for switching the switcher 36, and switches to add the second copy protection signal SB3. In this way, by selecting a copy protection signal that causes less deterioration in image quality, it is possible to avoid obstacles when viewing an image on a television monitor.
[0038]
FIG. 10 illustrates an example of processing when the above-described copy protection signal SB2 is generated by the signal generator 32. FIG. 10A shows a normal color burst signal SB1. FIG. 10B shows an example in which a copy protection signal SB2 having a pseudo burst signal b after a normal color burst signal a is generated. A phase control pulse is generated based on a timing signal from the timing controller 33, and a pseudo burst signal b having an inverted phase is generated in a section of the phase control pulse.
[0039]
FIG. 10C shows an example in which a copy protection signal SB2 having pseudo burst signals b and c before and after a normal color burst signal a is generated. Also in this example, phase control pulses corresponding to the pseudo burst signals b and c are used. Further, as shown in FIG. 10D, by generating both the phase control pulse and the gain control pulse based on the timing control pulse, the copy prevention signal SB2 including the pseudo burst signal b in which the gain is controlled together with the phase is generated. May be generated.
[0040]
Although the above-described copy protection signal SB2 has been described in detail, the other copy protection signal SB3 is the same as the conventional color stripe method. That is, the second copy protection signal SB3 is generated by inverting the phase of the entire color burst signal for 2 to 4 lines for every 20 lines with respect to the reproduced video signal. If a video signal whose burst signal is inverted in this way is recorded by an analog VCR, an APC (automatic phase control circuit) of the analog VCR uses the inverted burst signal as an original burst signal. , The color of the line is inverted and recorded. Therefore, when the recorded video signal is reproduced, a band whose color is inverted is displayed on the screen as shown in FIG. As a result, copying can be restricted.
[0041]
On the other hand, in a television monitor, the time constant of a PLL for forming a carrier for demodulating a color signal has a long time constant. You can see the image. However, there is also a television monitor in which the image quality deteriorates. In such a case, the user can select the first copy protection signal SB2 and thereby avoid the image quality deterioration.
[0042]
Next, as a mode in which the first copy protection signal SB2 is added to the analog video signal, there are several methods for effectively exerting the copy protection function. These will be described. FIG. 12 shows a first method. In this example, as shown in FIG. 12A, a copy protection signal SB2 having pseudo burst signals b and c before and after a color burst signal a is shown. The insertion positions of the burst signals b and c are devised. In FIG. 12B described below, the horizontal direction indicates the horizontal direction of raster scanning, and the vertical direction indicates the vertical direction of raster scanning. The hatched portion indicates the position where the pseudo burst signal exists within the vertical blanking period. This representation is common to other similar figures.
[0043]
First, as shown in part d of FIG. 12B, the pseudo burst signals c and b are inserted over a continuous block of several to several tens of lines, and this is repeated, for example, every 100 lines. Next, a part of the pseudo burst signal b with a shorter width than that inserted in the part d in FIG. 12B is further inserted into several lines to several hundred lines before and after the part d (part e in FIG. 12B). By adding the copy prevention signal SB2 in this way, it is possible to effectively cause image deterioration when copying. Further, depending on the characteristics of the television monitor, the copy prevention signal SB2 may cause an image quality failure. This can be reduced by providing a portion into which the copy protection signal SB2 is not inserted, as shown in a portion f of FIG. 12B. This f-part is preferably set near the vertical synchronization signal.
[0044]
Here, if the number of blocks (the number of lines) of the d part in FIG. 12B is increased to increase the deterioration of the image due to the copy guard, the PLL for the color burst signal cannot follow the television monitor and becomes unstable. Could be. Therefore, as shown in FIG. 13A and FIG. 13B, by arranging the blocks to which the pseudo burst signals b and c are added, for example, every field or every frame, it is possible to increase the effective area where the image is deteriorated. You may do it. This dividing method can be performed over several frames.
[0045]
FIG. 14 shows another example of the mode of adding the pseudo burst signal. In a home analog VCR, the position and width of a burst gate for detecting a burst signal may differ depending on specifications. In the copy prevention signal SB2, since the pseudo burst signal is inserted only in a part of the burst signal period, if the position and the width of the burst gate are different, the effect of the copy guard may not be obtained. For this reason, in the example shown in FIG. 14, as shown in the i, j, k, and l portions, the position and width of the pseudo burst signal insertion are changed with time. In this way, even if the position and width of the burst gate are different, the influence of the copy protection signal can be obtained.
[0046]
FIG. 15 shows another example of the mode of adding the pseudo burst signal. Depending on the specifications of the television monitor, when a pseudo burst signal is inserted, as in part e, flicker may occur at the boundary between the block where the pseudo burst signal is inserted and the line where it is not inserted. Therefore, as shown in FIG. 15, the width of the pseudo-burst signal is gradually changed at the beginning and the end of the block where the pseudo-burst signal exists, ie, at the m and n portions. By doing so, it is possible to prevent flicker symptoms in the television monitor.
[0047]
In one embodiment of the present invention, the AGC pulse generated by the AGC pulse generator 25 is controlled in accordance with CGMS in order to prevent copy by the above-mentioned pseudo burst signal and to further ensure copy prevention. That is, in the case of copy prohibition, a pseudo sync pulse having a level higher than the normal AGC reference level is inserted into the AGC reference level detection section of the video signal. For example, as shown in FIG. 16A, a pseudo sync C pulse is inserted in a part of the V blanking period of the video signal. FIG. 16B shows an enlarged portion where the pseudo sync pulse is inserted. For example, five pseudo sync pulses are inserted at a level obtained by adding the level p to the horizontal sync pulse. This level p is changed and inserted.
[0048]
In the analog VCR, there are many models that use the 1H horizontal synchronization pulse during the V blanking period to apply AGC as shown in FIG. 16C. Therefore, when a pseudo sync pulse having a larger amplitude than the horizontal sync pulse is inserted into 1H, the AGC circuit determines that the amplitude of the pseudo sync pulse is the reference level and performs AGC. As a result, since the AGC level is detected as the level of the pseudo sync pulse, the sync signal cannot be detected by amplitude separation, and normal reproduction cannot be performed. By using such an AGC pulse method, copy guard can be performed more reliably.
[0049]
In the embodiment of FIG. 3, two types of copy protection signals are prepared, and one of them is selected by the user. However, three or more types of copy protection signals may be prepared. More specifically, a modified example of the first copy protection signal SB2 may be used as the third copy protection signal.
[0050]
Further, in the configuration of FIG. 3, the generation circuits of the normal burst signal SB1 and the first and second copy protection signals SB2 and SB3 are shown as separate blocks. Since the copy protection signal is generated by controlling the phase, it is possible to share some hardware of these generation circuits. Although an adder is used to add a copy protection signal, it is also possible to use a modulation circuit that adds a normal color burst signal and then changes the phase only for a predetermined period. good. Further, according to the present invention, a copy prevention signal may be added to a composite signal format in which a luminance signal and a carrier chrominance signal are superimposed, instead of a component signal format.
[0051]
【The invention's effect】
As described above, according to the present invention, when copying is prevented by adding a copy preventing signal that makes the phase of a burst signal different from that of a normal signal, the video signal is viewed by a television monitor. In such a case, it is possible to prevent the image quality from deteriorating. Further, in the present invention, since information for restricting copying is recorded together with the digital video signal on a recording medium such as a pre-recorded tape or a DVD, copy prevention can be reliably performed.
[Brief description of the drawings]
FIG. 1 is a block diagram showing some examples of a video signal recording system to which the present invention can be applied.
FIG. 2 is a block diagram of an embodiment in which the present invention is applied to a case where a reproduced analog signal of a DVD player is recorded.
FIG. 3 is a block diagram of an output unit to which the present invention is applied.
FIG. 4 is a schematic diagram used for explaining an example of a CGMS and a trigger bit instructing generation of a copy restriction signal.
FIG. 5 is a schematic diagram used for describing an example of a CGMS recording method employed in a digital VCR.
FIG. 6 is a schematic diagram used for explaining an example of a CGMS recording method employed in a digital VCR.
FIG. 7 is a waveform chart showing an original signal and a color burst signal in a reproduced signal, respectively.
FIG. 8 is a waveform chart showing some examples of a first copy protection signal.
FIG. 9 is a waveform diagram showing that the width of a copy protection signal has increased after reproduction.
FIG. 10 is a timing chart for explaining some methods for generating a first copy protection signal.
FIG. 11 is a schematic diagram for describing copy protection by a second copy protection signal.
FIG. 12 is a schematic diagram illustrating a first example of a method of adding a first copy protection signal.
FIG. 13 is a schematic diagram illustrating a second example of the method of adding the first copy protection signal.
FIG. 14 is a schematic diagram illustrating a third example of the method of adding the first copy protection signal.
FIG. 15 is a schematic diagram illustrating a fourth example of a method of adding a first copy protection signal.
FIG. 16 is a waveform chart for explaining the AGC pulse method.
[Explanation of symbols]
6 ... DVD, 14 ... Output section for outputting a reproduced analog video signal, 15 ... Microcomputer, 16, 16Y, 16C ... Output terminal, 24, 25, 27 ... Adder , 31... A signal generator for generating a normal burst signal, 32... A signal generator for generating a first copy protection signal, and 33... A signal generation for generating a second copy protection signal , 35 ... Switcher controlled by microcomputer, 36 ... Switcher controlled by user's instruction, SB1 ... Normal color burst signal, SB2 ... First copy protection signal, SB3 ... second copy protection signal, b, c ... pseudo burst signal

Claims (10)

A video signal processing device for receiving a digital video signal reproduced from a recording medium or an analog video signal for analog output corresponding to a received digital video signal, and adding and outputting a signal for recording restriction,
Means for separating a control signal included in the reproduced digital video signal or the received digital video signal and indicating whether or not to perform recording restriction;
In the case where recording is restricted in response to the separated control signal, the recording apparatus further comprises signal addition means for adding a recording restriction signal to the analog video signal,
The recording restriction signal is a signal added to at least one of the sections on the front side and the rear side of the color burst signal, and is a signal having a phase different from the original phase of the color burst signal. Video signal processing device. The apparatus according to claim 1,
A video signal processing device, wherein the recording restriction signal is added to an analog video signal when copy generation restriction information accompanying a video signal to be output indicates a copy prohibited state. The apparatus according to claim 1,
The video signal processing device according to claim 1, wherein the recording restriction signal is a signal for inverting the phase of a color burst signal for several lines every predetermined number of lines. A video signal processing method for receiving a digital video signal reproduced from a recording medium or an analog video signal for analog output corresponding to a received digital video signal, and adding and outputting a signal for recording restriction, comprising:
Separating a control signal included in the reproduced digital video signal or the received digital video signal and indicating whether or not to perform recording restriction;
When recording is restricted in response to the separated control signal, a signal adding step of adding a recording restriction signal to the analog video signal is included.
The recording restriction signal is a signal added to at least one of the sections on the front side and the rear side of the color burst signal, and is a signal having a phase different from the original phase of the color burst signal. Video signal processing device. The method of claim 4, wherein
A video signal processing method, wherein the recording restriction signal is added to an analog video signal when copy generation restriction information accompanying a video signal to be output indicates a copy prohibited state. The method of claim 4, wherein
The video signal processing method according to claim 1, wherein the first signal is a signal for inverting the phase of a color burst signal for several lines every predetermined number of lines. Applicable to a video signal reproducing apparatus or a video signal reproducing method for detecting a state of a control signal provided on a recording medium and controlling addition of a recording restriction signal for restricting recording of an analog video signal based on the detected output. A recording medium for causing
The recording medium has a pack structure for storing a control signal for instructing whether to add a recording restriction signal for restricting recording of an aspect of an analog video signal to the pack to the analog video signal,
In the case where the recording of the aspect of the analog video signal is restricted, when the reproducing apparatus reproduces the digital video signal and outputs the digital video signal as an analog video signal, at least the front side and the rear side of the color burst signal for recording restriction. The control signal is to add a signal having a phase different from an original phase of the color burst signal to the analog video signal as the recording restriction signal, the signal being added to one of the sections. A recording medium for instructing. In order to correspond to a video signal reproducing apparatus or a video signal reproducing method for detecting a state of a control signal arranged on a recording medium and generating a recording restriction signal for restricting recording of an aspect of an analog video signal based on the detected output. Recording medium,
The recording medium has a sector structure for storing a control signal for instructing whether to generate a recording restriction signal for restricting recording of an aspect of an analog video signal with respect to a header added to the sector,
In the case where the recording of the aspect of the analog video signal is restricted, when the reproducing apparatus reproduces the digital video signal and outputs the digital video signal as an analog video signal, at least the front side and the rear side of the color burst signal for recording restriction. The control signal is to add a signal having a phase different from an original phase of the color burst signal to the analog video signal as the recording restriction signal, the signal being added to one of the sections. A recording medium for instructing. The recording medium according to claim 7, wherein
A recording medium, wherein the recording restriction signal is added to an analog video signal when copy generation restriction information accompanying a video signal to be output indicates a copy prohibited state. The recording medium according to claim 7, wherein
The recording medium according to claim 1, wherein the first signal is a signal for inverting the phase of a color burst signal for several lines every predetermined number of lines.

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