JP2001075870A - Information signal transmission method, information signal transmission system, information signal transmission device, and information signal reception device - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To ensure that copy information restriction control on an information signal can be performed reliably and properly even if a recording device is interposed in a non-compliant manner. An STB 2 is connected to an analog output terminal 43 of the STB 2 by a device information detecting unit 44.
The non-compliant device receiving the supply of the analog video signal from the device is a non-compliant device, and the copy control information superimposed on the output analog video signal as digital watermark information is “Copy Once (copy of one generation is possible)”.
Indicates that “No More”
Copy to "No More Copy"
An analog video signal on which the copy control information indicating “y” is superimposed is output.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an information signal transmission method and an information signal transmission method in a case where copy control information for restricting the generation of copy is added to an information signal such as a video signal or an audio signal and transmitted. The present invention relates to a system, an information signal transmitting device, and an information signal receiving device.

[0002]

2. Description of the Related Art Through broadcasting media such as digital broadcasting and communication media such as the Internet,
D (compact disc), MD (mini disc), D
2. Description of the Related Art Various digital contents have been provided via various recording media such as a VD (digital video disc).

[0003] On the other hand, illegal duplication (copying) of digital contents that have become abundantly provided
Copyright infringement is a problem. In order to cope with this problem, it has been considered to add information for copy control to digital contents, and to prevent illegal duplication using the additional information.

[0004] Controls for preventing this duplication include a case where duplication is not permitted at all depending on the information source and a case where duplication is permitted once but duplication from one time is prohibited ( Generation control). The former is the case of original software created and sold by a content maker, such as a DVD-ROM. The latter generation-limited copy control method is applied to, for example, broadcast information in broadcast media.

In the latter case of the generation-restricted copy control method, a method capable of effectively controlling the copy generation is desired. As a method of the copy control information capable of managing the copy generation, CGMS (Copy Generation) is used.
Management System) and a system using digital watermarking have been proposed.

[0006] The digital watermarking process is a process of embedding information as noise in a portion that is not important to human perception existing in image data or music data, that is, a portion that is not redundant to music or video. The additional information embedded in the image data or music data by such a digital watermarking process is not easily removed from the image data or music data. On the other hand, even after filtering processing and data compression processing on image data and music data, it is possible to detect additional information of a digital watermark embedded in the image data and music data from the image data and music data.

[0007] In the case of the copy control system using the digital watermarking process, "copy free" or "copy once (only one generation can be copied)" (One C
opt) "" No more copying allowed (No More Cop)
y) ”and“ Never Copy ”, indicating the copy generation and copy restriction status of the image data and music data on which the digital watermark information is superimposed.

[0008] "Copy Free"
Indicates that music data and image data can be freely copied. "Can be copied once (only one generation can be copied)
“(One Copy)” indicates that music data and image data can be copied only once. “No more copy prohibited” means that the music data and image data are copied from the music data and image data that can be copied once, and no further copying is prohibited. It is shown that. “Absolute duplication prohibited (Never Copy)” indicates that duplication is completely prohibited.

The digital watermark information superimposed on image data and music data is "one copy possible (One Copy)".
, The digital watermark processing is supported (that is,
The recording apparatus of (copy restriction processing) determines that the image data and music data can be copied and recorded, and executes recording. However, the recorded image data and music data include
"No more copying (No More Copy)"
The rewritten digital watermark information is superimposed. Then, the digital watermark information superimposed on the image data or music data to be recorded indicates “No more duplication prohibited (No
In the case of “More Copy)”, the recording device that supports the digital watermarking process prohibits the duplication recording of the image data and the music data and prohibits the execution of the recording.

In the CGMS system, for example, in the case of an analog image signal, 2-bit additional information for duplication control is superimposed on a specific horizontal section in the vertical blanking period. In this method, 2-bit additional information for copy control is added to digital image data and transmitted.

In the case of the CGMS system, the meaning of 2-bit information (hereinafter referred to as CGMS information) is [00]... Can be copied. [10]... Can be copied once (only one generation can be copied). ] ... Reproduction is prohibited (absolute reproduction is prohibited). In the CGMS system, there is no state of “no more duplication prohibited” described above.

The CGMS information added to the image information is [1
0], the CGMS-compatible recording apparatus determines that the duplicate recording of the image information is possible and executes the recording. However, the recorded image signal includes the CGMS rewritten to [11]. Information is added. If the CGMS information added to the image information to be recorded is [11], the CGMS-compatible recording apparatus prohibits the duplication recording of the image signal and prohibits the execution of the recording.

In addition, there is also a copy control method in which the copyable generation is arbitrarily set by, for example, the copyright holder of the image signal, and the copy generation restriction control is performed. In this case, for example, in the recording apparatus, each time the copy is performed, the copy control over a plurality of generations is performed by reducing the number of copyable generations of the copy control information added to the copied image signal.

That is, in the case of the copy control system using the digital watermarking process, the copy control information is changed from "copy generation once (Copy Once)" to "copy no more (NoMore Copy)". By changing the number of copyable generations indicated by the copy control information, copy generation restriction control over a plurality of generations becomes possible.

In the case of digital contents, an information signal such as image data is subjected to encryption processing (scramble processing) so as to reliably prevent unauthorized duplication of the information signal. I have. For example, IE
In case of EE1394 standard digital interface,
Between the electronic devices connected through the digital interface, an electronic device serving as an output destination of digital content can perform a copy control according to copy control information added to the information signal, such as a recording device (hereinafter referred to as a recording device). , Compliant devices.)
The device information about the electronic device is transmitted to the electronic device that outputs the digital content.

[0016] The digital content output source device encrypts the digital content and supplies it to the output destination electronic device. Then, communication is performed with a digital content output destination electronic device through a digital interface, and whether the output destination is a compliant device or copy control is performed according to copy control information added to the information signal. Is verified as a non-compliant device (hereinafter referred to as a non-compliant device), the copy control information added to the digital content is verified, and according to the verification result, the device is applied to the digital content. It is determined whether or not the key is to be sent to the output destination electronic device for decrypting the encryption.

For example, an electronic device to which an information signal is output is
If the device is a compliant device, a key for decrypting the encryption is provided to the output destination electronic device. Further, when the electronic device to which the information signal is output is a non-compliant device, a key for decrypting the encryption is not provided. As a result, illegal duplication of digital content can be effectively prevented. Such a communication control method is based on IEEE13.
It is called a 94 secure bus.

[0018]

However, a receiver called a set-top box (STB) for receiving digital contents through broadcast media, a personal computer having a communication function for receiving digital contents from communication media, or Inconvenience arises when information signals such as video signals and audio signals are supplied from a playback device such as a DVD or a recording / playback device to analog devices such as a conventionally used VTR (video tape recorder). May occur.

For example, an electronic device to which an information signal is output is
In the case of a conventional analog device (non-compliant recording device) such as a VTR, it is not possible to directly receive digital contents provided by being encrypted or compressed. For this reason, the digital contents are decrypted and compressed / decompressed, and are D / A converted and provided to analog devices. However, in the case of a conventional analog device, CG
It does not support the MS system or the copy control system using digital watermarking.

For this reason, a conventional analog VTR
In the case of using a (non-compliant recording device), the information signal to which the copy control information of “one generation copy permitted (Copy Once)” is added is recorded as it is without changing the state of the copy control information. It can be copied to media. Therefore, a recording medium on which an information signal that can be copied for one generation is recorded is created without any limitation, and it is not possible to appropriately limit the generation of the information signal copy.

This can also occur when digital information signals are transmitted through various digital interfaces such as the above-mentioned IEEE 1394 secure bus.
In other words, even when the above-described digital interface of the IEEE 1394 standard is used, if a digital information signal capable of being copied for one generation is transmitted to a non-compliant recording device, the state of the copy control information is not changed and the recording medium is not changed. Can be duplicated.

For this reason, when the electronic device to which the information signal is output is a non-compliant recording device and the information signal to be supplied to the device is one that can be copied for one generation. It is conceivable to protect the copyright of the information signal by not outputting the information signal. But in this case,
Even if the information signal has been recognized for one generation, it cannot be copied if the recording device is used non-compliant, which is inconvenient for the user.

As described above, when an information signal is supplied to an electronic device such as a recording device, even if the information signal is added with copy control information for performing copy generation restriction control, the recording device is non-compacted. If it is a client device, it will not be possible to properly limit the generation of duplication,
The copyright of the information signal cannot be protected.

[0024] In view of the above, the present invention has been made to solve the above-described problems, and therefore, whether the information signal is output as an analog signal or the digital signal, the information signal can be obtained. It is an object of the present invention to provide an information signal transmission method, an information signal transmission system, an information signal transmission device, and an information signal reception device that enable the generation limit control of duplication to be performed reliably and appropriately.

[0025]

In order to solve the above-mentioned problems, an information signal transmission method according to the first aspect of the present invention is a method for transmitting an information signal to which duplication control information for limiting generations of duplication is added. The method, wherein the electronic device that outputs the information signal receives device information about the partner device from a partner device that is the output destination of the information signal, and the partner device is added to the information signal. The device is not compatible with the copy generation restriction method based on the copy control information, and the copy control information is N (N is an integer of 1 or more)
When it indicates that generations can be replicated,
The duplication control information is rewritten with a reduced number of duplicatable generations, and the information signal to which the rewritten duplication control information is added is output.

According to the information signal transmission method of the first aspect of the invention, in the electronic device that outputs the information signal, the device information from the partner device is detected, and the partner device converts the information signal to the information signal. A non-compliant device that cannot perform copy control according to the added copy control information, and the copy control information added to the information signal is
If it indicates "N generations can be duplicated", 1 is subtracted from the number N of duplicatable generations of the duplication control information added to the information signal, and the duplication control information obtained by updating the number of duplicatable generations is obtained. The added information signal is transmitted to the output destination electronic device.

Thus, for example, when the information signal to which the copy control information indicating one generation copy is possible (Copy Once) is transmitted to a non-compliant device, further copy prohibition ( No More C
opt) "and the copy control information is added and transmitted. Even if the information signal whose copy control information has been updated is copied to the recording medium, the copied information signal cannot be copied again using a compliant recording device. The generation of copies can be properly restricted.

According to a second aspect of the present invention, there is provided the information signal transmitting method as set forth in the first aspect, wherein the destination device to which the information signal is output is transmitted to the own device. It has a function of sending information indicating the operation state as the device information, and the rewriting of the copy control information, the partner device is a recording device, and,
It is characterized in that it is performed when a recording state is set.

According to the information signal transmission method of the present invention, the partner device is a non-compliant recording device, is in the recording state, and transmits the information signal to the partner device. If the copy control information added to the information signal is "N generations of copy possible", the number N of copyable generations of the copy control information added to the information signal is subtracted, and the number of copyable generations N An information signal to which the updated copy control information is added is transmitted.

Thus, in the electronic device that outputs the information signal, the copy control information is updated only when it is necessary to update the copy control information for truly limiting the generation of the copy. Thus, the load on updating the copy control information can be reduced.

According to a third aspect of the present invention, there is provided the information signal transmitting method as set forth in the first or second aspect, wherein the copy control information includes the digital watermark information as the digital watermark information. It is characterized by being transmitted by being superimposed on an information signal.

According to the information signal transmission method of the present invention, the copy control information is digital watermark information formed by digital watermark processing, such as a spread spectrum signal, and is superimposed on the information signal. By being transmitted, the risk that the copy control information is removed or falsified from the information signal is reduced, and the copy control according to the copy control information can be reliably performed.

[0033]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an information signal transmission method and an information signal transmission device according to the present invention will be described below with reference to the drawings. In the embodiment described below, digital content such as a movie provided through broadcast media is received by a receiver called a set-top box (hereinafter, abbreviated as STB), demodulated, and demodulated. A case in which the data is supplied to a video tape recorder (hereinafter, abbreviated as VTR) as an apparatus will be described as an example. That is, in the following embodiments, the STB is used as an information signal transmitting device that transmits an information signal, and the VTR is used as an information signal receiving device that receives and processes an information signal.

It should be noted that a video signal of digital content provided through broadcast media is provided by adding CGMS information capable of controlling generation duplication restriction and copy control information as digital watermark information WM. It is. Further, in the embodiment described below, the digital watermark information WM includes a PN (Pseudorandom Noi).
The pseudo-noise code (se; pseudo-noise code) is used to spread-spectrum copy control information (copy generation restriction information) using a PN code.

The STB according to the embodiment described below
Each device such as a video recorder and a VTR can process audio signals as well as video signals. However, in the embodiment described below, to simplify the description,
The description of the audio system of each device is omitted.

[First Embodiment] [Regarding Information Signal Output Device] FIG. 1 illustrates a broadcast device (information signal output device) 1 used in a broadcast station that performs digital broadcasting in this embodiment. FIG. As shown in FIG. 1, a broadcasting device 1 according to this embodiment includes an input terminal 11, a digital watermark information superimposing unit (hereinafter, referred to as a WM superimposing unit) 12, and a digital watermark information forming unit (hereinafter, referred to as a WM forming unit). ) 13, A / D converter 1
4. Data compression processing unit 15, CGMS-D information adding unit 1
6, a CGMS-D information generation unit 17, an encryption unit 18, and a signal output unit 19.

As shown in FIG. 1, the WM forming unit 13 includes a synchronization detecting unit 131, a timing signal generating unit 132,
It includes a PN generation unit 133, a copy control information generation unit 134, an SS spreading unit 135, and a level adjustment unit 136.

In this embodiment, a video signal (analog signal) to be broadcast is supplied to an input terminal 11 through a WM superimposing section 12 and a synchronization detecting section 1 of a WM forming section 13.
31. The synchronization detection unit 131 extracts a vertical synchronization signal V and a horizontal synchronization signal H from the video signal supplied thereto.
And outputs this detection output to the timing signal generator 132.
To supply.

The timing signal generator 132 uses the vertical synchronizing signal V and the horizontal synchronizing signal H as reference signals.
A PN code reset timing signal RE (hereinafter, abbreviated as a reset signal RE) indicating the generation start timing of the PN code, and a PN generation enable signal EN (hereinafter, abbreviated as the enable signal EN) indicating a section in which the PN code is generated. ) And a clock signal PNCLK.

FIG. 2 is a block diagram for explaining the timing signal generator 132 of the broadcasting device 1 according to this embodiment. As shown in FIG. 2, the timing signal generator 13
2 includes a PN generation timing signal generator 321, a PN clock signal generator 322 including a PLL, and a timing signal generator 323.

In this embodiment, FIG.
As shown in, the PN generation timing signal generation unit 321
And the timing signal generation unit 323 includes the synchronization detection unit 1
The vertical sync signal V and the horizontal sync signal H from the sync detector 31 are supplied, and the horizontal sync signal H from the sync detector 31 is supplied to the PN clock generator 322.

The PN generation timing signal generator 3
The reference numeral 21 generates a reset signal RE for determining a repetition period of a PN code sequence for spreading for duplicating control information using the vertical synchronization signal V and the horizontal synchronization signal H as reference signals. In this example, the reset signal RE
Is a signal of one frame cycle, for example.

The PN generation timing signal generator 321
In the case of this example, the enable signal EN is generated using the vertical synchronization signal V and the horizontal synchronization signal H as reference signals. In this embodiment, the enable signal EN is, for example, a low-active signal. When the enable signal EN is at a low level,
The PN generation unit 133 is set to an operation state.

The PN clock generator 322 generates a clock PNCLK synchronized with the horizontal synchronizing signal H using a PLL. Further, the timing signal generation section 323 generates various timing signals used in the broadcasting device 1 of the present embodiment based on the vertical synchronization signal V and the horizontal synchronization signal H.

The reset signal RE, the enable signal EN, and the clock signal PNCLK among the signals generated by the timing signal generator 132 are supplied to the PN generator 133, and the enable signal EN and the clock signal PNCLK are It is also supplied to the copy control information generation unit 134.

The PN generator 133 outputs a reset signal RE
, A PN code is generated according to the enable signal EN and the clock signal PNCLK. That is, in this example, the PN generator 133 is reset by the reset signal RE in one frame cycle, and changes the PN code sequence PS of the predetermined code pattern from its head to 1 every one clock of the PN clock signal PNCLK. Generate at the rate of chips. In this way, a PN code string PS having a predetermined code pattern is generated from the beginning of each frame and supplied to the SS spreading section 135.

As described above, the PN generator 133 generates the M-sequence PN code string PS based on the enable signal EN, the PN clock signal PNCLK, and the reset signal RE. , A multi-stage shift register, and several exclusive OR circuits for calculating an appropriate tap output of the shift register.

On the other hand, based on the clock signal PNCLK, the duplication control information generating section 134 performs spectrum spreading and superimposition on the video signal input through the input terminal 11 at the timing of the enable signal EN from the timing signal generating section 132. It generates duplication control information and outputs it based on the clock signal PNCLK, and
5 That is, the copy control information generation unit 134
At the same timing as the PN code string PS, the copy control information string F
S is formed and supplied to the SS diffusion unit 135.

In this embodiment, if the video signal to be transmitted is permitted to be copied freely, the copy control information generating section 134 sets the message "Copy Free (Copy Free)". Is generated, and if duplication is not permitted at all, "absolute duplication prohibited (Ne
ver Copy) is generated. If the video signal to be transmitted is a signal for which one generation of duplication has been recognized, copy control information indicating "one generation of duplication is possible (Copy Once)" is generated.

As described above, the copy control information generator 34
This is generated when low bit rate information indicating which copy control state is possible for duplication is possible or not, and which one-generation duplication is possible, as copy control information.

In this embodiment, PN generating section 133 generates PN code string PS in accordance with clock signal PNCLK only when PN code generation is enabled (enable state) by enable signal EN. It is made to let. The enable signal EN also indicates the generation timing of the copy control information, as described above.

Therefore, the PN code is generated only when the enable signal is enabled by the enable signal, and the copy control information is generated, so that, for example, every other frame or every other frame. In an appropriate region of a video signal, digital watermark information that is spread control information is generated in an appropriate region of the video signal, such that digital watermark information can be formed and superimposed on every other frame of the video signal, as described later. It can be superimposed on a video signal.

Further, in this embodiment, the copy control information generating section 134 determines which copy is performed by a control signal generated in the control section 20 in response to an instruction from the operator input through the key operation section 21. Whether to generate control information is controlled. Therefore, the operator of the broadcasting device 1 can generate the target copy control information in response to, for example, an instruction from the copyright holder of the video signal (content) to be broadcast.

The SS spreading unit 135 performs the duplication control information sequence FS
Is spread by the PN code string PS,
The copy control information formed as the digital watermark information WM is formed and supplied to the level adjustment unit 136. Level adjuster 13
6 adjusts the level of the digital watermark information WM to a level at which the digital watermark information WM does not deteriorate the video signal when the supplied digital watermark information WM is superimposed on the video signal. To supply.

[0055] The WM superimposing section 12 superimposes digital watermark information WM formed by spread spectrum on the analog video signal input to the broadcasting device 1. Here, the level of the digital watermark information WM is adjusted by the level adjusting unit 136. In this embodiment, the digital watermark information WM whose superimposition level has been adjusted to such an extent that the reproduced image is not deteriorated is converted to the analog image. Superimposed on the signal. In this case, the digital watermark information WM is superimposed at a level smaller than the dynamic range of the video signal.

The video signal on which the digital watermark information WM indicating the state of the copy control is superimposed is supplied to the A / D converter 14. The A / D converter 14 converts the analog video signal from the WM superimposing unit 12 into a digital video signal, and supplies the digital video signal to the data compression processor 15.

The data compression processing unit 15 converts the supplied digital video signal into M in this embodiment.
The data is compressed by the PEG method and supplied to the CGMS-D information adding unit 16. In this specification, CG
The letter "D" in MS-D means digital. The CGMS-D information adding unit 16 adds a CGMS-D generating unit 17 to the data compressed digital video signal.
The CGMS-D information supplied from is added.

The CGMS-D information generating section 17 generates CGMS-D information to be added to a video signal to be transmitted. The CGMS-D information generation unit 17 also has a key operation unit 21 similar to the copy control information generation unit 134 described above.
Which CGMS-D information is to be generated is controlled by a control signal generated in the control unit 20 in accordance with an instruction from the operator input through the PC.

Therefore, the operator of the broadcasting device 1 can generate CGMS-G information in accordance with an instruction from the copyright holder of a video signal (content) to be broadcast, for example. The CGMS-D information generated by the CGMS-D information generation unit 17 means one of “copy permitted [00]”, “one generation copy permitted [10]”, and “copy prohibited [11]”. It is.

That is, the CGMS-D information generation unit 17
If the video signal to be transmitted is a signal that is permitted to be freely copied, C indicating that copying is possible is performed.
If GMS-D information [00] is generated and copying is not permitted at all, CGMS-D information [11] indicating a copy-prohibited state is generated. Then, when the video signal to be transmitted is a signal of which only one generation of duplication has been recognized, CGMS-D information indicating "one generation duplication is possible [10]" is generated.

In the CGMS-D information adding section 16, C
The video signal to which the GMS-D information has been added is transmitted to the encryption unit 18.
Supplied to In this embodiment, the encryption unit 1
8 includes, for example, a CSS (Cont.)
ents Scramble System).

The digital video signal that has been subjected to the encryption processing in the encryption section 18 is supplied to a signal output section 19,
Here, after processing for output such as level amplification processing is performed, broadcasting is performed to a user (recipient) through, for example, an antenna or a cable.

As described above, the broadcasting device 1 of this embodiment
For the output video signal, as copy control information,
Duplicate control information, which is digital watermark information (spread spectrum signal) by spectrum spreading, is superimposed on the video signal, and CGMS-D information is added and output.

Since the digital watermark information WM is superimposed on the video signal, for example, even if a digital video signal on which the digital watermark information WM is superimposed is converted into an analog video signal, the digital watermark information WM is removed. It will not be done. Further, even when the digital watermark information WM is superimposed on the video signal, the video signal does not deteriorate.

FIG. 3 shows copy control information which is converted to digital watermark information (spread spectrum signal) by spectrum spreading and is superimposed on the information signal, and an information signal on which digital watermark information is superimposed in this embodiment. The relationship with a certain video signal is shown by a spectrum. The copy control information contains a small amount of information, is a low bit rate signal, and is a narrow band signal as shown in FIG. When this is subjected to spread spectrum, FIG.
The signal has a wide bandwidth as shown in FIG. At this time, the level of digital watermark information (SS duplication control information (SS means spectrum spread)) formed by spread spectrum decreases in inverse proportion to the band expansion ratio.

This digital watermark information (SS copy control information)
Is superimposed on the video signal from the input terminal 11 by the WM superimposing unit 12. In this case, as shown in FIG. 3C, SS is set to a level smaller than the dynamic range of the video signal as the information signal. Copy control information is superimposed. By superimposing in this way, deterioration of the main information signal can hardly occur. Therefore, as described above, when the video signal on which the SS duplication control information is superimposed is supplied to the monitor receiver and the video is reproduced, the SS duplication control information has almost no effect, and a good reproduced video is obtained. It is something that can be done.

On the other hand, as will be described later, when the inverse spread spectrum is performed to detect the SS copy control information, FIG.
As shown in (d), the SS duplication control information is restored again as a narrowband signal. By giving a sufficient band spreading factor, the power of the duplication control information after despreading exceeds the information signal and becomes detectable.

In this case, since the SS copy control information superimposed on the video signal is superimposed on the video signal at the same time and within the same frequency, it is impossible to delete or correct it by replacing the frequency filter or simple information. .

Therefore, since the SS duplication control information superimposed on the video signal is not removed and its falsification is difficult, the duplication control which can surely prevent the illegal duplication becomes possible.

Further, in the above-described configuration, the spread spectrum is performed using a PN code string generated using the vertical synchronizing signal V and the horizontal synchronizing signal H as reference signals. For this reason, the PN code sequence for inverse spectrum spreading required when detecting the SS duplication control information from the video signal includes the vertical synchronization signal V detected from the video signal,
The horizontal synchronization signal H can be easily generated using the reference signal, and the spread spectrum signal superimposed on the video signal can be quickly and accurately detected.

Here, the case where one broadcast program such as a movie is broadcast has been described as an example, but in the case of digital broadcast, a plurality of broadcast programs are multiplexed and broadcast on one broadcast channel. Is what you can do. For example, a broadcast signal in which a plurality of broadcast apparatuses shown in FIG. 1 are provided, a signal from an encryption unit 18 of each broadcast apparatus is supplied to a multiplex unit (multiplex apparatus), and a plurality of broadcast program signals are multiplexed. And broadcast this through the signal output unit 19, or store the output signal from the encryption unit 18 of the broadcasting device 1 shown in FIG. 1 in a recording medium,
It is also possible to multiplex and broadcast a plurality of broadcast programs stored in a recording medium.

For the sake of simplicity, in the following, for the SS copy control information, which is digital watermark information, “one generation copy is possible” is described as “Copy Once” and “no more copy is prohibited”. Is "No More
"Copy" and "Absolute duplication prohibited" means "Never
"Copy F" and "Copy free" is "Copy F
ree ".

[Regarding Set Top Box] FIG.
FIG. 1 is a block diagram showing a configuration example of an STB 2 of this embodiment to which an information signal transmitting device according to the present invention is applied. The STB 2 is a broadcast device 1 described with reference to FIG.
And demodulates a digital broadcast broadcasted through the Internet, and forms and outputs a signal to be supplied to an electronic device such as a monitor receiver or a recording device.

As shown in FIG. 4, ST in this embodiment
B2 is a receiving antenna 31, a tuner unit 32, a descramble unit 33, a demultiplex unit 34, an encryption unit 35, a CGMS-D rewrite unit 36, IEEE 139
4 standard digital interface (in FIG. 4,
Described as IEEE1394 I / F. 37, a digital output terminal 38, a CDMS-D decoding unit 39, a data compression / decompression unit 40, a D / A conversion unit 41, a digital watermark information decoding unit (hereinafter, referred to as a WM decoding unit) 42, and a digital watermark information rewriting unit ( Hereinafter, it is referred to as a WM rewriting unit.) 4
3, an analog output terminal 44, a device information detection unit 45, a connection detection unit 46, and a control unit 50.

The control unit 50 includes a CPU, a ROM,
A microcomputer provided with a RAM and the like, which receives an instruction operation (instruction input) from an operator (user) through a key operation unit and controls each unit of the STB 2 in accordance with an instruction from the user, though not shown. Can be done.

The digital broadcast signal received by the receiving antenna 31 is supplied to a tuner 32.
A tuning control signal according to the user's tuning operation is supplied from the control unit 50 to the tuner unit 32, and a broadcast signal of a channel according to the user's tuning operation is selected and de-tuned.
The data is supplied to the scramble unit 33. In the descrambling unit 33, a descrambling process for descrambling (encrypting) the broadcast signal supplied thereto is performed. Then, the signal of the descrambled channel is supplied to the demultiplex unit 34.

In this embodiment, a digital broadcast signal received by STB2 includes a plurality of broadcast programs. For this reason, the demultiplex unit 34
In, based on a selection control signal corresponding to a user's selection operation supplied from the control unit 50, data of a target broadcast program is extracted from an output signal from the tuner unit 32, and the extracted broadcast program data is extracted by the encryption unit 35. , CGMS-D decoding unit 39 and data compression / decompression unit 40.

Then, the encrypting section 35 performs a predetermined encrypting process on the video data (digital video signal) to be output, and in this embodiment,
The CGMS-D rewrite unit 36 outputs the digital output through the digital interface 37 of the IEEE 1394 standard.

In the IEEE 1394 standard interface, as described above, transmission digital information is encrypted in order to prevent unauthorized duplication, but it is verified whether the output destination is a compliant device. At the same time, it verifies the CGMS-D information added to the video signal, which is information for duplication control, and determines whether or not to send a key to the output destination to decrypt the encryption according to the verification result. To determine. The above communication control method is IEEE
This is called a 1394 secure bus, and the digital interface is thereby effectively prevented from unauthorized copying.

That is, the encrypting unit 35 encrypts the output data from the demultiplex unit 34 based on a different encryption key for each communication under the control of the control unit 50. The video data encrypted by the encryption unit 35 is transmitted to a CGMS-D rewrite unit 36, an IEEE
Through the 1394 digital interface 37, it is supplied to the electronic device of the output destination through the digital output terminal 37. IEEE 1394 digital interface 37
Converts data so as to conform to the IEEE 1394 digital interface standard and outputs data.

At this time, the control unit 50 sets the IEEE
It communicates with the output destination device via the E1394 interface 37, and determines whether the output destination device is a compliant device or, if it is a compliant device, a recording device.

Then, the control unit 50 determines the type of the copy control information from the CGMS-D decoding unit 38, which will be described later, and the identification information of the electronic device as the output destination through the IEEE 1394 interface 36. It is determined whether or not to transmit the encrypted key information for decrypting the encrypted data to the output destination.

For example, when the output destination is a non-compliant device, the encryption key information is not passed to the output destination device. Further, even if the output destination is a compliant device, the output destination is a recording device, and CG
When the MS-D information is [11], the encryption key information is
Do not pass to the output device. By doing so, it is possible to prevent the video data from being illegally copied by the output destination electronic device.

However, if the CGMS-D information is “10” indicating that one-generation copy is possible, the encryption key information is passed to the output destination just because the output destination is a non-compliant electronic device. Without this, it is impossible to copy video data for which one generation of copying is permitted, which is inconvenient for the user.

Therefore, the control unit 50 of the STB 2 according to this embodiment includes a CGMS-D decoding unit 3 described later.
8 and the output of the copy control information from the IEEE 1394
From the discrimination information of the electronic device of the output destination via the interface 36, the electronic device of the output destination is a non-compliant electronic device, and the CGMS-D information is “10” indicating that one generation of copy is possible. In that case, CGMS-
By controlling the D information rewriting unit 36, the CGMS-D information is rewritten from "10" to "11" indicating absolute copy prohibition.

When the output destination electronic device is a non-compliant electronic device and the CGMS-D information is “10” indicating that one generation of copy is possible,
As described above, the CGM rewritten from "10" indicating that one-generation copy is possible to "11" indicating that absolute copy is prohibited
The video data to which the SD information is added is output, and the encryption key information is passed to the output destination. Also, even if the output destination is a compliant device, if it is a recording device and the CGMS-D information is [11], the encryption key information is not passed to the output destination device. Also,
If the CGMS-D information is "00" or CGMS-D cannot be detected, it is determined that the copy is free.
Pass the encryption key information to the output destination.

In this way, the STB of this embodiment
No. 2 prevents the digital data, that is, video data, from being illegally copied by the output destination electronic device. And, in the case of STB2 of this embodiment, S
The one-generation copy-enabled video data received by TB2 can be copied using a non-compliant recording device, and the video data copied by the non-compliant recording device includes: Since the CGMS-D information of "11" indicating the absolute copy prohibition is added, the subsequent copy is prohibited, and the generation restriction of the copy can be properly controlled.

As described above, in the STB 2 of this embodiment, the CGMS-D decoder 39 separates the video data from the video data by the function of the digital interface of the IEEE 1394 standard in order to prevent unauthorized duplication of the video data. The 2-bit CGMS information added to the specified position is extracted and supplied to the control 50. The control unit 50 can detect the content of the copy control for the video data to be output, based on the CGMS information from the CGMS-D decoding unit 39.

In this specification, a compliant device is compatible with copy generation restrictions. That is, as described above, a device that can also rewrite the copy control information such as rewriting the CGMS-D information of “10” to “11” is a compliant device.

On the other hand, the STB 2 of this embodiment has an analog output terminal 44 and converts a broadcast signal received and tuned into a broadcast signal.
As described above, the video data of the target broadcast program extracted by the demultiplex unit 34 can be output as an analog signal.

The STB 2 of this embodiment receives supply of device information from the output destination electronic device even when the analog video signal is supplied to the output destination device, and the output destination device transmits the analog video signal as digital watermark information. In accordance with the copy control information superimposed on the analog video signal to be output, it is possible to determine whether or not the device is a compliant device capable of performing copy control.

The device at the output destination is a non-compliant device, and the electronic watermark information superimposed on the analog video signal output from the STB 2 is “Copy”.
Once ", S
In TB2, the copy control information, which has been digital watermark information, is shifted to information indicating “No More Copy”.

Thus, the analog video signal output from the analog output terminal 44 of the STB 2 of this embodiment is supplied to a non-compliant recording device and is allowed to be copied to a recording medium. The generation limit of duplication can be appropriately set so that the analog video signal duplicated by the recording device of the client is not duplicated. Therefore, as described above, the WM decoding unit 42 and the WM rewriting unit 4 are provided in a stage preceding the analog information signal output terminal 44.
3. A device information detecting unit 45 and a connection detecting unit 46 are provided.

In this embodiment, since the video data from the demultiplex unit 34 is data-compressed, it is supplied to the data compression / decompression unit 40.
Here, it is decompressed. The video data decompressed and decompressed and expanded to the original state before the compression is applied to the D / A converter 4.
1 is supplied. The D / A converter 41 converts the compressed and decompressed video data into an analog video signal,
It is supplied to the decoding unit 42 and the WM rewriting unit 43.

The WM decoding section 42 includes a D / A conversion section 41
And detects the copy control information superimposed as the digital watermark information on the analog video signal from the MFP and decodes the contents of the copy control indicated by the copy control information. In this embodiment, as described above, by multiplying the narrow band, high level, low bit rate copy control information by a PN code, which is a spreading code generated at a sufficiently fast period, the video signal is Converts to digital watermark information of a wideband and minute level without affecting. Then, the digital watermark information, that is, the copy control information subjected to the spectrum spreading is superimposed on the video signal and transmitted.

The WM decoding unit 42 which detects the digital watermark information (SS copy control information) superimposed as described above and determines the content of the copy control indicated by the copy control information.
Can be configured as shown in FIG. That is, as shown in FIG. 5, the video data from the demultiplex unit 34 is supplied to the despreading unit 424 and also to the synchronization detection unit 421. The synchronization detection unit 421 detects the vertical synchronization signal V and the horizontal synchronization signal H, and supplies the detection output to the timing signal generation unit 422.

The timing signal generator 422 has the same configuration as the timing signal generator 132 of the broadcasting device 1 described above. Based on the supplied vertical synchronizing signal V and horizontal synchronizing signal H, a reset signal is generated. RE, an enable signal EN, a clock signal PNCLK, and other timing signals are formed. Therefore, the timing signal generator 422 of the STB 2 will be described using the same reference numerals as having the same configuration as the timing signal generator 132 shown in FIG.

The PN generation timing signal generator 321
The reset signal RE is generated using the vertical synchronization signal V and the horizontal synchronization signal H as reference signals. This reset signal R
E is a signal of one frame cycle, similar to the reset RE used in the information signal output device described above.

The PN generation timing signal generator 321
Further, an enable signal EN is generated using the vertical synchronization signal V and the horizontal synchronization signal H as reference signals. In this example, the enable signal EN is set to PN in any frame.
The signal is generated as a signal for generating the PN code from the generator 423. That is, the enable signal EN is
This signal is a low active signal. In this STB2, it is a signal that becomes low level in any frame.

The PN clock generator 322 uses a PLL to generate a PN clock PNCL synchronized with the horizontal synchronization signal H.
Generate K. In addition, the timing signal generation unit 323
4 based on the vertical synchronizing signal V and the horizontal synchronizing signal H.
The various timing signals used in STB2 shown in FIG. The reset signal RE, the enable signal EN, and the PN clock signal PNCLK generated by the timing signal generator 422 are output from the PN generator 42.
3 is supplied.

[0101] The PN generating section 423 is provided with the broadcast device 1 described above.
The configuration is the same as that of the PN code generator 133 of FIG. Then, the PN generator 423 outputs the reset signal RE.
In this embodiment, according to the enable signal EN and the clock signal PNCLK, the same P as in the case where the copy control information is spread spectrum by frame is used.
An N code sequence PS (PN code sequence for despreading) is generated at the same timing with respect to the analog video signal supplied to the WM decoding unit 42.

That is, the PN generation section 423 is reset by the reset signal RE in one frame cycle in this example, and only when the PN code can be generated (enable state) by the enable signal EN, the clock signal PNCLK is output. Generates a PN code sequence PS.

Therefore, in this embodiment, S
The PN generation unit 423 of the TB2 is the WM of the broadcast device described above.
Similarly to the PN generating unit 133 of the forming unit 13, a PN code string PS having a predetermined code pattern is generated for each frame from the beginning. As a result, the PN generator 413 of the STB 2 generates a PN code string PS that repeats every frame in any frame. The PN code string PS thus obtained from the PN generating section 423 is supplied to the despreading section 424.

In the despreading section 424, the PN generating section 4
Using the PN code string PS from 23 as a spreading code for despreading, despreading is performed, and a copy control information string FS that is spectrum-spread and superimposed on the analog video signal is obtained. This copy control information sequence FS is supplied to the WM determination unit 425, and the copy control state is determined. Then, the determination output is supplied to the control unit 50.

As a result, the control unit 50 determines whether the content of the copy control indicated by the copy control information added as digital watermark information to the analog video signal to be output is “Copy Free” or “Never Cop”.
y "or" Copy Once "can be detected.

In this embodiment, the connection detection section 46 outputs the output destination of the analog video signal to the analog output terminal based on the impedance of the analog transmission line connected to the analog output terminal 44 and the voltage level of the signal. Is detected, and a detection output is supplied to the control unit 50. The control unit 50
When the detection output from the connection detection unit indicates that the electronic device at the output destination is connected to the analog output terminal 44, the device information detection unit 45 is controlled to detect the device information.

In this embodiment, the device information detection section 45 outputs the device information from the electronic device to which the analog video signal transmitted through the analog transmission line connected to the analog information signal output terminal 44 is output. Is detected. In this embodiment, a compliant electronic device capable of performing copy control on an analog video signal in accordance with the copy control information superimposed on the analog video signal as digital watermark information transmits device information on its own device. The output source of the analog video signal, in this embodiment, can be transmitted to the STB 2.

As will be described in detail later, in this embodiment, the compliant electronic device that receives the supply of the analog video signal includes information indicating the type of the device itself, such as a playback device or a recording device, and a playback status. Device information such as information indicating an operation state of the own device such as a recording state, for example, as an electric signal of a predetermined pattern, an analog output terminal of an analog video signal output source and an analog input terminal of the own device. Connected to a transmission line for transmitting an analog video signal.

In this case, the device information converted into an electric signal is
The signal is supplied to a transmission line for transmitting the analog video signal as a minute level signal that does not affect the analog video signal. By doing so, the compliant electronic device transmits the device information relating to itself to the STB2, which is the output source of the analog video signal, via the transmission line through which the analog video signal is transmitted.

Then, the device information detecting section 45 of the STB 2
Is connected to an analog transmission line that connects the analog information signal output terminal 44 and the WM rewriting unit 43, as shown in FIG. 4, receives a signal from this analog transmission line, and outputs the analog information signal. The device information transmitted in reverse through the output terminal 44 is detected, and the detected output is supplied to the control unit 50.

When the device information from the electronic device to which the analog video signal is output is detected by the device information detecting section 45, the electronic device of the output destination connected to the analog output terminal 43 is compliant with the device. In addition, the control unit 50 of the STB 2 can detect the operation state of the device, such as a playback device or a recording device. When the device information detection unit 45 cannot detect the device information, it can determine that the electronic device to which the analog signal is output is a non-compliant device.

In the STB 2 of this embodiment, the control 50 indicates that the detection output from the WM decoding unit 42 indicates “Copy Once (copy of one generation is possible)”. If the device information is not detected and the electronic device of the output destination is determined to be a non-compliant electronic device, the WM rewriting unit 43 is controlled so that the electronic watermark information superimposed on the analog video signal to be output. Is rewritten. In this case, the WM rewriting unit 43 includes the D / A conversion unit 4
The copy control information superimposed as the digital watermark information on the analog video signal from No. 1 is rewritten from the information indicating “Copy Once” to the information indicating “No More Copy”.

In this embodiment, the WM rewriting unit 43 removes, from the analog video signal, the copy control information indicating “Copy Once” superimposed on the analog video signal as digital watermark information, and then “No More Cop”
The copy control information indicating “y” is newly superimposed as digital watermark information.

The digital watermark information superimposed on the analog video signal can be removed by subtracting the same digital watermark information as the digital watermark information superimposed on the analog video signal. In this embodiment, as described above, the PN code reset for each frame allows, for example,
Alternatively, the copy control information is spectrum spread and superimposed so as to be completed for each of a plurality of frames.

For this reason, the STB 2 can detect the copy control information used as the digital watermark information.
In other words, the control unit 50 of the STB 2 knows what type of PN code sequence is used for the copy control information that is the digital watermark information. For this reason, in this embodiment, the control unit 50 can determine which digital watermark information is superimposed on which frame of the analog video signal. By subtracting the same digital watermark information as the information, an analog video signal from which the digital watermark information has been removed can be obtained.

In the STB 2 of this embodiment, the WM rewriting section 43 also includes a WM forming section substantially similar to the WM forming section 13 shown in FIG.
By electronically spreading the copy control information indicating "eCopy", digital watermark information indicating "No More Copy" is formed and superimposed on the analog video signal. Then, an analog video signal on which digital watermark information indicating “No More Copy” is superimposed is output through the analog output terminal 44.

As described above, the STB2 of this embodiment is
Indicates that the analog video signal to be output has "Co"
In the case where the electronic watermark information indicating “py once” is superimposed and the electronic device to which the analog video signal is output is a non-compliant device, the electronic watermark information superimposed on the analog video signal to be output To "N
o More Copy ”, and the“ No M
An analog video signal on which digital watermark information indicating "ore Copy" is superimposed is output.

Thus, similarly to the case where the video data is output through the IEEE 1394 digital interface 37, the one-generation copy-permitted video data received by the STB 2 of this embodiment is converted into an analog video signal as a non-compressed signal. It can be supplied to a client's recording device and copied to a recording medium. And
In this case, the analog video signal copied to the recording medium by the recording device in a non-compliant manner includes “No M
Since the copy control information indicating “more copy” is superimposed as digital watermark information, the copied analog video signal can be prevented from being further copied, and a one-generation copy-enabled digital broadcast program can be prevented. Copyright can be properly protected.

As described above, the STB2 of this embodiment is
Can prevent a non-compliant recording device from creating a recording medium on which a one-generation copy-enabled video signal has been copied indefinitely. In addition, instead of using the passive method of prohibiting duplication by a non-compliant recording device of a one-generation copyable video signal, the one-generation copyable video signal is
Copying can be performed even by using a non-compliant recording device, and further duplication of the copied video signal is prohibited, so that generation restriction of duplication can be appropriately performed.

In the WM rewriting unit 42 of the STB 2 of this embodiment, a PN code of a sequence different from a PN code sequence in which copy control information already superimposed as digital watermark information on an analog video signal is spread. The digital watermark information indicating “No More Copy” is formed using the columns, and this is further superimposed on the video signal on which the digital watermark information indicating “Copy Once” is superimposed, and is output. Good.

In the case of digital watermark information using spread spectrum, by changing the sequence of spread codes used for spread spectrum, it is possible to detect each piece of copy control information which is spread spectrum by a spread code of a different sequence and superimposed on a video signal, for example. can do.

When digitally outputting video data, the digital watermark information superimposed on the output video data as digital watermark information is rewritten so that the copy control superimposed on the video data as digital watermark information is performed. The status of the replication control indicated by the information and the CGMS-D
The state of the copy control indicated by the information may be matched.

In this case, the CGMS-D information rewriting unit 36 rewrites the copy control information superimposed on the video data as digital watermark information at the preceding or subsequent stage.
What is necessary is just to provide M rewriting part. In this case as well, similarly to the case of the WM rewriting unit 43 for the analog video signal described above, after removing the copy control information indicating “Copy Once” superimposed on the video data as digital watermark information, a new “ No Mor
e Copy ”may be superimposed as digital watermark information, or may be“ No More Copy ”that is spread spectrum using a spread code different from the original digital watermark information. The information may be superimposed on the digital watermark information already superimposed.

In the STB 2 of this embodiment, when video data is output through a digital interface conforming to the IEEE 1394 standard, not only CGMS information but also digital watermark information detected and decoded by the WM decoder 41. In consideration of the copy control information superimposed on the video data (video signal), it may be determined whether or not a key for decryption is to be transmitted to the output destination electronic device.

As described above, when the CGMS-D information and the copy control information as the digital watermark information are used, if either one of them can be detected, appropriate copy control can be performed. Further, even if one of the CGMS information and the digital watermark information is subjected to an attack such as falsification, the duplication control can be appropriately performed.

[Compliant Recording Device]
Next, a compliant recording device 3 to which the information signal receiving device according to the present invention is applied will be described. FIG.
FIG. 1 is a block diagram of a configuration example of a compliant recording device 3 according to this embodiment. The compliant recording device of this embodiment is, for example, an analog VTR,
An analog video signal output from the STB 20 described above with reference to FIG. 4 can be supplied and recorded on a video tape.

As shown in FIG. 6, a VTR 3 which is a compliant recording apparatus of this embodiment has an analog input terminal 61, a connection detecting section 62, a device information transmitting section 63, a W
M rewriting unit 64, recording control unit 65, WM decoding unit 6
6. The control unit 70 is provided.

Then, the connection detecting section 62 performs the above-described ST.
Similarly to the connection detection section 46 of B2, the analog input terminal 61
It detects whether or not the electronic device of the output source of the analog video signal is connected based on the impedance of the transmission line through which the analog video signal is transmitted or the voltage level of the signal,
The detection output is supplied to the control unit 70.

The control unit 70 controls the device information transmission unit 63 when the detection output from the connection detection unit 62 indicates that the electronic device which is the output source of the analog video signal is connected to the analog input terminal. Then, the device information of the own device is supplied as an electric signal to the transmission line through which the analog video signal is transmitted.

As a result, the VTR 3 of this embodiment is
Transmits the device information of its own device to the electronic device to the output source of the analog video signal through a transmission line connecting the analog output terminal of the electronic device that outputs the analog video signal and the analog input terminal of the VTR 3. As described above, the device information transmitting section 63 of the VTR 3 converts the analog video signal into a minute-level signal that does not affect the analog video signal and supplies the signal to the transmission line that transmits the analog video signal.

On the other hand, the analog video signal supplied to the VTR 3 through the analog input terminal 61 is supplied to the WM rewriting section 64 and the WM decoding section 66 of the VTR 3 of this embodiment.

The WM decoding unit 66, like the WM decoding unit 41 of the STB 2 described above with reference to FIGS. 4 and 5, performs copy control in which digital watermark information is superimposed on the analog video signal supplied thereto. The information is detected, and the content of the copy control indicated by the copy control information is decoded. And
The decoded content of the copy control is supplied to the control unit 70.

Thus, the copy control state indicated by the copy control information superimposed as the digital watermark information on the analog video signal supplied through the analog input terminal 61 is
It is detected by the control unit 70. That is, based on the discrimination output from the WM decoding unit 66, the control unit 70 determines whether the analog video signal supplied to the VTR 3 is “Copy Free” or “Never C”.
"copy", "Copy Once", or "No Mo"
re Copy "is detected.

[0134] The control 70 determines that the copy control information in which the discrimination output from the WM decoding section 64 is superimposed as digital watermark information on the analog video signal supplied to the recording device 3 is "Copy Once". , A control signal is supplied to the WM rewriting unit 64, and the copy control information indicating “Copy Once” superimposed as digital watermark information on the analog video signal supplied to the WM rewriting unit 64 indicates “No More Copy”. Control is performed so as to rewrite the copy control information.

Thus, when the control signal is supplied from the control unit 70, the WM rewriting unit 62 is superimposed on the video signal supplied to the WM rewriting unit 62 as digital watermark information in accordance with the control signal. "Co
py Once ”, the copy control information is“ No Mo
re Copy ”to copy control information indicating“ N.
o More copy control information indicating “More Copy” is supplied to the recording control unit 65 with an analog video signal superimposed thereon as digital watermark information.

The rewriting of the digital watermark information in the WM rewriting unit 64 is performed by the STB2 described above with reference to FIG.
Is performed in the same manner as the WM rewriting unit 42 of FIG. That is, W
After removing the digital watermark information indicating “Copy Once” superimposed on the analog video signal, the M rewriting unit 64 newly superimposes digital watermark information indicating “No More Copy”.

Alternatively, the digital watermark information indicating “Copy Once” is obtained by further adding digital watermark information indicating “No More Copy” formed by spectrum spreading using a PN code of another sequence or another spreading code. Superimposed on the signal.

The detection output from the WM decoding unit 66 is “Copy Free”, “No More Co
py ”,“ Never Copy ”, or when no digital watermark information is detected from the analog video signal supplied to the VTR 3, the WM rewriting unit 6
In No. 4, the digital watermark information is not rewritten,
The analog video signal supplied to the WM rewriting unit 64 is supplied to the recording control unit 65 as it is.

The control unit 70 determines that the discrimination output from the WM decoding unit 66 is “Copy Free”.
, Or “Copy Once”, and when the digital watermark information is not detected from the analog video signal supplied to the VTR 3, the recording control unit 65 performs the recording of the analog video signal. Control.
The discrimination output from the WM decoding unit 66 is “Nev
In the case of “er Copy” or “No More Copy”, the control unit 70 controls the recording control unit 65 so as not to record the analog video signal.

As described above, the VTR 3 of this embodiment is
, Through the transmission line that connects the analog output terminal of the analog video signal output source and its own analog input terminal,
It is possible to transmit device information indicating that the device is a compliant recording device capable of performing copy control in accordance with copy control information superimposed as digital watermark information on an analog video signal.

In the case of a conventional non-compliant electronic device such as a VTR which cannot perform copy control in accordance with copy control information superimposed as digital watermark information on an analog video signal, the WM decoding unit It does not have a function for performing copy control based on copy control information that is digital watermark information, or a device information sending unit.

Therefore, the STB described with reference to FIG.
2, when the electronic device information is not transmitted from the electronic device connected to the analog output terminal 43, the electronic device to which the analog video signal is output is transmitted to the copy control information superimposed on the analog video signal as digital watermark information. It is possible to determine that the device is a non-compliant device that cannot perform copy control based on the device.

As described above, in the case of a compliant electronic device, the device information of its own device is transmitted to the output source of the analog video signal. It is possible to determine whether the electronic device to which the video signal is output is a compliant device or a non-compliant device.

As described above, in the STB 2 of this embodiment shown in FIG. 4, even if the electronic device to which the analog video signal is output is a non-compliant recording device, It is possible to appropriately restrict the generation of duplication of a signal.

[Operation of STB2] FIG. 7 is a flowchart for explaining the operation of STB2 of this embodiment. In this embodiment, the processing shown in FIG. 7 is repeatedly executed at an appropriate timing by the control unit 50 after the power supply to the STB 2 is turned on.

First, the control unit 50 of the STB 2
After confirming the detection output from the device information detection unit 44, the electronic device connected to the analog output terminal 44 and serving as the output destination of the analog video signal from the STB 2 is a copy that is superimposed on the analog video signal as digital watermark information. Based on the control information, it is determined whether or not the electronic device is a compliant electronic device capable of performing copy control, that is, whether or not it is compatible with WM (digital watermark information) (step S101).

In the determination processing in step S101, if the electronic device to which the analog video signal is output determines that it is compatible with WM, the analog video signal (information signal) is output as it is (step S102). The process shown in FIG. This is because if the electronic device at the output destination is WM compatible, the electronic device at the output destination, based on the copy control information superimposed on the analog video signal from the STB 2 as digital watermark information, This is because the duplication control for the analog video signal can be appropriately performed.

If it is determined in step S101 that the electronic device to which the analog video signal is output is not a WM-compatible electronic device, the control unit 50
Is based on the discrimination output from the WM decoding unit 42, the copy control information superimposed as digital watermark information on the analog video signal output from the STB 2 is “Copy
It is determined whether the information indicates "Once" (copy of one generation is possible) (step S103).

In the determination processing of step S103, when it is determined that the copy control information superimposed as the digital watermark information on the analog video signal does not indicate “Copy Once”, the process proceeds to step S102, and the analog video signal is processed. The signal is output as it is, and the processing shown in FIG. 7 ends.

Therefore, if the copy control information is “Copy”
In the case of "Free" or "Never Copy", the analog video signal is output as it is. Then, even when the copy control information is “Never Copy”, the copy can be performed by a non-compliant recording device.

However, the copy control information superimposed on the analog video signal as digital watermark information is "Never".
"Copy" means that if a compliant playback device or a compliant recording device is used, the video signal cannot be played back or copied, so that use of the video signal without restriction is prevented. Copyright can be protected.

In the determination processing of step S103, when it is determined that the copy control information superimposed as the digital watermark information on the analog video signal indicates “Copy Once”, the control 50 causes the WM rewriting unit 43 to Under the control of the copy control information that is superimposed on the analog video signal as digital watermark information.
y Nonce ”to“ No More Co
py], and this “No More”
An analog video signal on which copy control information indicating "Copy" is superimposed as digital watermark information is output through the analog output terminal 44 (step S104).

As a result, even if the electronic device analog-connected to the STB 2 of this embodiment is a non-compliant recording device that cannot correspond to the copy control information used as the digital watermark information, the one received by the STB 2 The generation-reproducible video signal is supplied to a non-compliant recording device and can be reproduced.

However, even if the one-generation copy-enabled video signal received by the STB 2 is copied to a recording medium by a non-compliant recording device, the copied video signal does not include “No More Copy”. Is superimposed as digital watermark information, so that further duplication is prohibited. Therefore,
The duplication control (duplication generation restriction control) of the one-generation copy-enabled video signal received by the STB 2 can be properly performed, and the copyright of the video signal can be properly protected.

FIG. 8 shows that STB2 of this embodiment has W
FIG. 4 is a diagram for explaining a case where an M-compatible (compliant) VTR is connected and a case where a WM non-compliant (non-compliant) VTR is connected; FIG. 8A shows STB2 of this embodiment.
FIG. 8B shows a case where the WM compatible (compliant) VTR 3 of this embodiment shown in FIG. 6 is analog-connected. FIG. 8B shows the STB 2 of this embodiment and the WM non-compliant (non-compliant). The case where the VTR 6 and the VTR 6 are connected in an analog manner is shown.

8A and 8B, the VTR 3 and VTR 6 receiving the supply of the analog video signal from the STB 2 are provided with the WM-compliant (compliant) digital VTR.
(DVTR) 4 and an analog VTR 5 are connected. In this case, the DVTR 4 is
3. Digitally connected to VTR6.

[0157] The video signal of the digital broadcast program selected and received by STB2 can be copied for one generation, and copy control information indicating "Copy Once" is superimposed as digital watermark information. 8A and FIG. 8B.

In the case of FIG. 8A, since the VTR 3 is WM compatible, the STB 2 outputs the analog video signal on which the copy control information indicating “CopyOnce” is superimposed as digital watermark information as it is. The VTR 3 can record, on a video tape, an analog video signal on which duplication control information indicating “Copy Once” as digital watermark information is superimposed, as indicated by a circle in FIG. 8A. At this time, “CopyOnc” superimposed as digital watermark information on the analog video signal
e ", the copy control information indicating" No More Cop "
y ".

Therefore, the analog video signal recorded on the video tape by the VTR 3 includes “No Mo”.
Copy control information indicating “re Copy” is superimposed as digital watermark information. Then, the analog video signal recorded on the video tape is reproduced by the VTR 3,
For example, as shown in FIG. 8A, when all are supplied to the WM-compatible recording devices DVTR4 and VTR5,
The video signals supplied to VTR4 and VTR5 include:
Copying is prohibited because copy control information indicating "No More Copy" is superimposed as digital watermark information.

On the other hand, in the case of FIG. 8B, the VTR 6 does not support WM, so that the STB 2 outputs “Copy Onc” superimposed on the analog video signal as digital watermark information.
e ", the copy control information indicating" No More Cop "
y ”, and this“ No More C
An analog video signal on which duplication control information indicating “copy” is superimposed as digital watermark information is output to the VTR 6.

Since the VTR 6 does not support WM, the VT
Even if the analog video signal supplied to R6 is superimposed with copy control information as digital watermark information, it is possible to record on a video tape without being affected by the copy control information. Therefore, as shown by a circle in FIG. 8B, the analog video signal from STB2 includes "No Mo"
Even when the copy control information indicating “re Copy” is superimposed as digital watermark information, the VTR 6 can record the analog video signal from the STB 2 on a video tape.

In this case, since the copy control information indicating “No More Copy” has already been superimposed on the analog video signal recorded on the video tape by the VTR 6 in the STB 2 as digital watermark information, as shown in FIG. 8B. , VTR 6 reproduces the analog video signal recorded on the video tape, and the WM compatible DVTR 4,
When supplied to the VTR 5, "No More C
Copy is prohibited based on the copy control information indicating “copy”.

Therefore, even in the case shown in FIG. 8B, the analog video signal (first
Copying is possible for the video signal of the next generation, but once it is copied, copying is prohibited in a WM-compatible recording device. In other words, even if a video signal that can be copied for one generation is copied by a recording device that does not support WM, an analog video signal on which copy control information indicating “Copy Once” is superimposed as digital watermark information is recorded. It is possible to prevent the creation of a recorded medium, and to appropriately limit the generation of duplication for a video signal that can be duplicated for one generation.

In this embodiment, VTR3
In the above, the connection detection unit 62 performs the detection after detecting that the electronic device that outputs the analog video signal is connected to the analog input terminal of the own device. STB
In 2, the device information detection unit 45 detects the device information after the connection detection unit 46 detects that the electronic device of the output destination of the analog video signal is connected to its own analog output terminal 44. .

As described above, since the STB 2 and the VTR 3 include the connection detection unit 46 and the connection detection unit 62, for example, the VTR 3 is configured such that the electronic device that outputs the analog video signal is connected to its own analog input terminal. When it is detected that the device information has been transmitted, the device information is transmitted once or a predetermined number of times.

On the other hand, STB2 detects device information when detecting that an electronic device to which an analog video signal is output is connected to its own analog output terminal. In this case, the device information is detected for a predetermined time, and if the device information cannot be detected during that time, it is determined that the output destination is a non-compliant device.

Then, the STB 2 outputs an analog video signal after completing the process of detecting the device information for a predetermined time of the device information. As described above, by transmitting the device information from the VTR 3 and detecting the device information in the STB 2 before outputting the analog signal from the STB 2, the analog video signal is affected by the device information at all. Can never be.

Of course, as described above, since the device information is a signal of a minute level, for example, the connection detection unit 46,
62 is not provided and while the power is turned on to STB2,
The device information may be always detected, and the device information may be constantly transmitted while the VTR 3 is powered on.

In this case, for example, as the device information, the electronic device to which the analog video signal is output, in this embodiment, the VTR 3 is in the playback state (playback mode) or the recording state (recording mode) Information indicating the operating state, such as the status, is also transmitted to the STB 2 as device information.

In STB2, when the electronic device to which the analog video signal is to be output is a recording device and is in the recording state based on the detected device information, the video signal to be output is output. When the copy control information or the CGMS-D information added as the digital watermark information indicates “one generation copy is possible”, as described above, the copy control information converted into the digital watermark information is used. Is rewritten to indicate "no more duplication prohibited" or the CGMS-D information is rewritten to indicate "absolute duplication prohibition".

In other words, STB2 rewrites the copy control information and CGMS-D information, which are digital watermark information, only when the output destination electronic device is in the recording mode and is necessary. To do. By doing so, it is possible to minimize the rewriting of the copy control information and the CGMS-D information, which are the digital watermark information, to a minimum necessary. Therefore, it is possible to reduce the load on the STB 2 for rewriting the copy control information. it can.

The VTR 3 sends out device information including the operation state once or every predetermined number of times each time the operation state changes. And S
In the TB2, the device information may always be detected, and the operation state of the electronic device to which the analog video signal is output may be detected in real time.

The VTR 3 sends out device information including the operating state at every predetermined timing, regardless of the operating state. And
Also in this case, the STB 2 constantly detects the device information so that the operation state of the electronic device to which the analog video signal is output can be detected almost in real time.

In the VTR 3, while the device information transmitting section 64 is transmitting the device information, the processing on the analog video signal supplied to the VTR is not performed.
The control unit 70 may control. By doing so, it is possible to record an analog video signal which is not affected by the device information at all on the recording medium.

[Specific Example of Converting Device Information to Small Level Signal] In the above-described embodiment, the device information transmitted from the VTR 3 to the STB 2 is a small level signal that does not affect the analog video signal. The above description has been made on the assumption that the signal is supplied to a transmission line for transmitting an analog video signal. When the device information is a signal of a very small level,
Various methods can be used, but by supplying the device information as digital watermark information to the transmission line that transmits the analog video signal, it is possible to transmit the analog video signal without affecting it and reliably. it can.

Therefore, in this example, the device information is spread as a spectrum to obtain digital watermark information.
A case of transmitting and receiving between the VTR 3 and the STB 2 of the above-described embodiment via a transmission line of an analog video signal will be described. Also in this case, STB2 and VTR3 are as shown in FIGS. However, in the VTR 3, the configuration of the device information transmitting unit 62 is as shown in FIG. 9, and the configuration of the device information detecting unit 45 of the STB 2 is as shown in FIG.

First, the VT of this example will be described with reference to FIG.
The device information transmission unit 63 of R3 will be described. In this example, the spreading code is PN (Pseudoran).
The device information is spread spectrum using a code of a dom noise (pseudo noise code) sequence (hereinafter referred to as a PN code).

As shown in FIG. 9, the device information sending section 63 of this example includes a timing control section 631, a PN generating section 63
2, a device information sequence generator 633 and a spectrum spreader (hereinafter referred to as a spreader) 634.

In this embodiment, the timing control section 631 receives, for example, a reference clock signal, and generates a PN code string generation timing signal based on the reference clock signal.
Various timing signals such as a PN code string reset timing signal, a device information sequence formation timing signal, and a device information bit switching timing signal are formed.

The generation timing of the PN code string indicates the timing at which one chip of the PN code string having a predetermined code pattern is generated. The reset timing signal of the PN code string indicates the timing at which a PN code string having a predetermined code pattern is generated from the beginning.

The device information sequence forming timing signal indicates the timing at which one chip of the device information sequence to be spread spectrum by the PN code sequence is generated.
In addition, the bit switching timing signal of the device information is
It shows the timing of switching the bits of the device information output as the device information sequence in the multi-bit device information.

The PN code string generation timing signal and the PN code string reset timing signal generated by the timing control section 631 are supplied to a PN generation section 632.
Further, the device information sequence forming timing signal and the device information bit switching timing signal are transmitted to the device information sequence forming unit 6.
33.

The PN generation section 632 includes the timing control section 6
A PN code sequence having a predetermined code pattern is generated from the head thereof in accordance with the timing signal from 31, and is supplied to the spreading unit 634. In this case, the device information sequence forming unit 633 forms a device information sequence from the device information supplied from the control unit 70 in response to the timing signal from the timing control unit 631, 634.

The spreading section 634 spreads the device information sequence with a PN code sequence, thereby converting the device information into a minute-level spread spectrum signal (digital watermark information). This spread spectrum signal is supplied to a transmission line for transmitting an analog video signal connecting the analog output terminal of STB2 and the analog input terminal of VTR3, and the VTR3
To STB2.

Next, with reference to FIG.
The device information detection unit 45 of the TB 2 will be described. FIG.
Is a block diagram for explaining the device information detection unit 45 of the STB 2 in this example. As shown in FIG. 6, the device information detection unit 45 of the STB 2 in this example includes a despreading unit 451, a timing control unit 452, a PN generation unit 453, and a device information determination unit 454.

The device information detecting section 45 of the STB 2
Is connected to a stage preceding the analog output terminal 44, and receives a signal supplied from a transmission line for transmitting an analog video signal. The signal from the transmission line is supplied to the despreading unit 451 of the device information detecting unit 45. This despreading unit 451 includes
The PN code string is supplied from the PN code generator 453.
In this case, the PN generator 453 determines the P of the VTR 3 described above.
N generator 632 and has a VTR
3 generates a PN code string having the same code pattern as that used in the device information transmission section 63 of FIG.

That is, the timing control section 452 of the device information detection section 45 of the STB 2 generates a PN code string generation timing signal and a PN code string reset timing signal, similarly to the timing control section 631 of the VTR 3.
These two timing signals provide the same timing as the timing used in the device information transmitting section 63 of the VTR 3.

The PN generator 453 generates a PN code sequence having the same code pattern as the PN code sequence used when the device information is spread spectrum, based on the timing signal from the timing controller 452. As described above, it is supplied to the despreading unit 451.

[0189] Despreading section 451 performs despread spectrum spreading on the signal supplied thereto using the PN code string from PN generating section 453, and supplies the result to device information determining section 454. The device information determination unit 454 includes:
The information obtained as a result of the inverse spread spectrum from the reverse spread unit 451 is integrated, the contents of the original device information before the spread spectrum are determined, and this is notified to the control unit 20 of the STB 2.

In the despreading unit 451, at the same timing as when the device information is spread spectrum, the device information is supplied to the transmission line for transmitting the analog video signal as digital watermark information. If the same PN code is not multiplied, device information cannot be obtained accurately.

For this reason, for example, the device information determination unit 454
In the case where the level of the signal supplied from the despreading unit 451 is lower than a predetermined level, for example, when the despread spectrum is not accurately performed, this is notified to the timing control unit 452 and the PN is notified. The timing signal is adjusted so that the generation timing of the code string is shifted, so that despreading can be performed accurately.

As described above, the device information is spectrum-spread, whereby the device information is converted into minute-level digital watermark information, and the minute-level digital watermark information is supplied to a transmission line for transmitting an analog video signal. Even when a video signal is being transmitted, the device information is repeated at all times or at intervals so that the analog video signal is not affected, and the STR is transmitted from the VTR 3.
The data can be transmitted back to TB2.

[Second Embodiment] In the above-described first embodiment, transmission and detection of device information are performed when it is detected that a partner device has been connected. Is set to a very low level signal, and is transmitted at all times or at intervals while the other device is connected.

However, as described in the above-described first embodiment, the device information is output to the information signal output source that outputs a predetermined information signal such as a video signal, for example, in the output control of the information signal. What is used.
For this reason, it is conceivable that the device information is transmitted from the output destination of the information signal in response to a request from the output source of the information signal.

That is, taking as an example a case where STB 2 and VTR 3 in the first embodiment described above are connected by a transmission line, the VTR 3 is transmitted only when there is a request for transmission of device information from STB 2. Supplies the device information to the analog transmission line. As a result, compared to the case where the device information is transmitted constantly or repeatedly at intervals, the VTR
3 can reduce the load on the transmission of the device information.

Also, the STB 2 may detect the device information when it requests transmission of the device information, so that the load on the detection can be reduced and the device information can be more reliably transmitted. Can be detected. Further, since the device information is transmitted in response to a transmission request from the STB 2, even when the device information is transmitted through a transmission line through which an analog video signal is transmitted, the device information affects an information signal such as a video signal. Can be reduced.

Therefore, in the second embodiment, the device information is transmitted from the output destination of the information signal in response to a request from the output source of the information signal.
In the second embodiment, the information signal is output from an STB (set-top box) and the information signal is output from a VTR (video tape recorder). An example in which an analog video signal is transmitted as a signal will be described.

FIG. 11 shows an STB according to the second embodiment.
FIG. 7 is a block diagram for explaining No. 7; As shown in FIG. 11, the STB 7 according to the second embodiment has a request sending unit 47 provided between the WM rewriting unit 43 and the analog output terminal 44. The other components are configured similarly to the components of the STB 2 of the first embodiment described above with reference to FIG. For this reason, in the STB 70 of the second embodiment, portions configured similarly to the STB 2 of the first embodiment include the STB of the first embodiment.
The same reference numerals as those in FIG.

Also in the second embodiment, when the connection detecting section 46 of the STB 7 detects that a partner device has been connected to the analog output terminal 44 of its own device, it notifies the control section 50 of this. . Control part 5
0, upon receiving a notification that the partner device has been connected to the analog output terminal 44, forms a control signal for controlling to output a device information transmission request.
To supply.

In the second embodiment, the request sending section 41 sends a request for sending an electrical signal of a predetermined fixed pattern requesting the sending of device information based on a control signal from the control section 41. The analog output terminal 44 is formed and supplied to a transmission line connected to the analog output terminal 44, so that it is transmitted to a partner device connected to its own analog output terminal 44.

As described above, the ST of the second embodiment is described.
In B7, when it is detected that the partner device is connected to the analog output terminal, for example, “Copy On”
Requesting transmission of device information to an electronic device to which an analog video signal is output as necessary, such as when a video signal of a broadcast program in which copy control information indicating "ce" is superimposed as digital watermark information is selected. I do.

If the output destination electronic device transmits the device information in response to the device information transmission request from the STB 2, the STB 2 can obtain the device information only when necessary. To be.

FIG. 12 shows a VTR according to the second embodiment.
FIG. 8 is a block diagram for explaining No. 8; As shown in FIG. 12, the VTR 8 according to the second embodiment has a request detecting section 67 provided at a stage subsequent to the analog input terminal 61. Other components are configured in the same manner as the components of the VTR 3 of the first embodiment described above with reference to FIG. For this reason, in the VTR 8 of the second embodiment, the same components as those of the VTR 3 of the first embodiment are denoted by the same reference numerals as those of the VTR 3 of the first embodiment. Description is omitted.

The request detection section 67 of the VTR 8 detects a transmission request which is a fixed pattern electric signal requesting transmission of device information from a signal input through the analog input terminal 61. Upon detecting the transmission request from the source of the analog video signal, the request detection unit 67 notifies the control unit 70 that the transmission request for the device information has been transmitted.

Upon receiving the notification that the transmission request has been transmitted, the control unit 70 forms a control signal for controlling the device information transmission unit 63 so as to transmit the device information. 63. The device information sending unit 63 sends device information as an electric signal to the analog input terminal 61 according to a control signal from the control unit 70.
Feeding the transmission leads to.

As a result, the device information transmitting section 6 of the VTR 8
The device information of the electric signal transmitted from the analog input terminal 61 of the VTR 8 and the analog output terminal 4 of the STB 7
The data is transmitted from the VTR 8 to the STB 7 via a transmission line connecting the four houses. Then, in STB7, the first
As in the case of the STB 2 of the embodiment, the output to the VTR 8 is performed based on the device information from the VTR 8 and the copy control information superimposed as digital watermark information on the video signal of the received and tuned television broadcast. Rewriting control of digital watermark information superimposed on a video signal to be reproduced.

[0207] Thus, as described above, the load on the transmission of the device information in the VTR 8 can be reduced as compared with the case where the device information is transmitted constantly or repeatedly at intervals. In the STB 7, when necessary, device information can be obtained from the electronic device to which the analog video signal is output.

[Third Embodiment] The first and second embodiments described above are described.
In the embodiment, the case where video data (digital video signal) is output through an IEEE1394 standard digital interface and the case where an analog video signal is output have been described as examples. However, some digital interfaces are not limited to those of the IEEE 1394 standard, and some digital signals are transmitted serially using one transmission line.

In this case, as in the case of the analog transmission in the first and second embodiments described above, since there is only one transmission line for serially transmitting video data, transmission of device information is not performed. You can't. However, the present invention can also be used for serial transmission of digital signals using one transmission line.

FIGS. 13 and 14 are diagrams for explaining an example in which the present invention is applied to a case where video data (digital signal) is serially transmitted through one transmission line. In the following, the ST of the first embodiment described above will be described.
A case will be described as an example in which video data is digitally transmitted between B2 and VTR3.

In this case, the video data to be handled is digital serial data.
The configuration of TR3 is not much different from that of the first embodiment. Then, for example, from STB2 to VTR
13 is transmitted via one transmission line to the video data Me as shown in FIG.
1 through the same transmission line transmitting video data to B2.
When the digital device information Ks as shown in FIG. 3B is transmitted in reverse, the following is performed.

That is, the device information transmitting section 63 converts the digital device information Ks (FIG. 13B) into digital device information Kn of a minute level that does not affect the binarization determination of the video data Me as shown in FIG. 13C. (FIG. 16C). In other words, the threshold (threshold) th used when the digital device information Ks is used to determine whether the digital video signal is binarized.
The digital device information Kn, which is a signal of a very low level, is supplied to a transmission line for transmitting video data.

Thus, for example, even when video data is transmitted through a transmission line for transmitting video data, the digital device information Kn is added (superimposed) to the video data Me as shown in FIG. 13D. The digital device information Kn is converted to the digital audio information M
It does not affect the binarization determination of e.

Then, in the device information detecting section 45 of the STB 2, the VTR 3 adds a very small level of device information to the video data Me in the VTR 3 (FIG. 1).
4A) is binarized using a predetermined threshold th to obtain the original video data Me (FIG. 14).
Obtain B).

Then, a signal Ds (FIG. 1) in which a minute level of device information Kn is added to the video data Me.
4A), the original video data Me obtained by the binarization process
By subtracting (FIG. 14B), a minute level of digital device information Kn (FIG. 14C) is obtained. By performing a process of restoring the signal level to the digital device information Kn of a minute level, as shown in FIG. 14D, the device information is transmitted from the VTR 3 to the STB 2 through one transmission line for serially transmitting video data. Can be transmitted in reverse.

As described above, even when video data is serially transmitted through one transmission line, the device information can be transmitted to the electronic device that outputs the video data through the transmission line. Then, in this way, the electronic device from which the video data is output, in this example, STB2
Detects device information transmitted reversely through one transmission line for transmitting video data.

Then, using the detected device information and the copy control information superimposed on the video data to be output as digital watermark information, the video signal output destination electronic device is a non-compliant electronic device. If the copy control information superimposed on the output video data as digital watermark information indicates “Copy Once”, the copy control information superimposed on the video data as digital watermark information is referred to as “No More Cop”.
The video data whose copy control information is rewritten is output by rewriting ni indicating "y".

Thus, as in the case of the first and second embodiments described above, even when one generation of copy-enabled video data is supplied to a non-compliant electronic device, the copy generation restriction is imposed. Can be properly performed.

As described above, when digital data is transmitted serially, similarly to the case where the information signal of the first and second embodiments is transmitted analogly, device information is transmitted and operating state information is transmitted. And the like, from one digital data output destination electronic device to a digital data output source electronic device through one transmission line (digital serial transmission line) connecting a digital data output source and a digital data output destination. Can be transmitted.

[Fourth Embodiment] In the above-described embodiment, an example has been described in which the STB and the VTR are connected in a one-to-one relationship. However, a plurality of electronic devices may be connected to the STB. For example, as shown in FIG. 15, a plurality of recording devices 9 and 10 may be connected to STB2.

As described above, when a plurality of electronic devices are connected to the STB 2, the compliant recording device 9
And the non-compliant recording device 10 in some cases. In this case, a problem may occur if the video signal on which the copy control information indicating “Copy Once” is superimposed as the digital watermark information is output as it is because there is a compliant recording device.

That is, a video signal on which copy control information indicating “Copy Once” is superimposed as digital watermark information may be directly copied to a recording medium by a non-compliant recording device, and the first generation of the first generation may be illegally copied. A recording medium on which a video signal that can be copied (a first-generation video signal) is recorded is created.

Therefore, as shown in FIG. 15, when a plurality of electronic devices are connected to STB2, which is an information signal transmitting device, STB2 obtains device information of the electronic device from each electronic device. To For example, in STB2,
If a plurality of electronic devices are connected via the above-described IEEE 1394 standard digital interface, the IEEE
With the function of the digital interface of the EE1394 standard, each device including the STB2 can know what electronic device is connected to itself.

When at least one non-compliant electronic device is connected, the CGMS-D information or the CGMS-D information added to the output video data (digital video signal) or the analog video signal is output. When the copy control information or the like, which is the digital watermark information, indicates "one generation of copy is possible", the copy control information is rewritten to indicate "no more copy is prohibited" or "absolute copy is prohibited". Video data or an analog video signal to which the rewritten copy control information is added is output.

In this case, when the electronic device to which the video data and the analog video signal are output is an electronic device such as a non-compliant recording device, the video data and the analog video signal can be copied. However, the copy control information indicating “no more duplication prohibited” or “absolute duplication prohibition” is added to the video data or analog video signal to be copied. Duplication is prohibited.

On the other hand, when the electronic device to which the video data and the analog video signal are output is an electronic device such as a compliant recording device, the supplied video data and the analog video signal include “No more Since the copy control information indicating "copy prohibited" or "absolute copy prohibited" is added, the copy is prohibited according to the copy control information.

If at least one non-compliant electronic device is connected to STB2, STB2
The second control unit 50 indicates that even if the video data or the analog video signal is permitted to be copied for one generation, there is a risk that the information signal may be illegally duplicated, and the control unit 50 cannot properly output the information signal. ST message to notify
LCD (liquid crystal display) provided in B2, ST
The information is supplied to a monitor receiver connected to B2 and displayed.

As a result, the user can be informed that there is a possibility that inconvenience may occur, and the user can take measures such as removing a non-compliant device from the STB 2 as necessary.

Of course, through an interface other than the IEEE1394 standard digital interface,
Even when a plurality of electronic devices are connected to one information signal transmitting device, if the information signal transmitting device can detect device information from each of the electronic devices connected to the own device, Similarly, even in the case of connection, appropriate processing can be performed, and the copyright of the information signal can be reliably and appropriately protected.

[0230] In the above embodiment, the description has been made assuming that video signals are transmitted and received between electronic devices.
It is not limited to this. The present invention can be applied to a case where both a video signal and an audio signal are transmitted, a case where only an audio signal is transmitted, and a case where a computer program or computer data is transmitted.

In the above-described embodiment, an example has been described in which an STB (set-top box) is used as an information signal output source and a VTR (video tape recorder) is used as an information signal output destination. However, the electronic device that outputs the information signal (the information signal transmitting device) and the electronic device that outputs the information signal (the information signal receiving device) are not limited to the above-described embodiment.

For example, DVD (digital video disk) playback equipment and recording and playback equipment, LD (laser disk) playback equipment, video tape recorder, CD playback equipment, MD playback equipment, recording and playback equipment, cassette tape recorder, etc. The information signal transmitting apparatus according to the present invention can be applied to a device that outputs various information signals such as a video signal and an audio signal.

The recording apparatus using various recording media such as a magnetic recording medium such as a video tape, a hard disk, and a floppy disk, a magneto-optical recording medium such as an MD (mini disk), and an optical recording medium such as a DVD. The information signal receiving device according to the invention can be applied. Further, for example, an electronic device capable of outputting supplied information to another electronic device, such as a television receiver or various relay devices, may also include the information signal transmitting device or the information signal receiving device according to the present invention. Can be applied.

The present invention can be applied to a case where data is transmitted between computers such as a personal computer or between a computer and another electronic device. The present invention is also applicable to a case where data received by a computer having a communication function is supplied to a so-called slave device such as a hard disk device or a CD-R device connected to the computer.

Further, in the above-described embodiment, the non-compliant electronic device has been described as not having the function of transmitting device information. However, the non-compliant electronic device has a non-compliant electronic device. In order to transmit device information notifying that the device is, in the electronic device of the output source of the information signal, based on the detected device information, whether the electronic device of the output destination of the information signal is a compliant device, It may be determined whether the device is a non-compliant device.

Further, in a copy control system (copy control system) in which the number of generations that can be copied can be set arbitrarily, “Copy Once” is changed to “No Mor”.
Similarly to the state transition to “eCopy”, by reducing the number of remaining copyable generations, it is possible to appropriately perform copy generation limit control.

In the case of a duplication control system in which the number of duplicatable generations can be arbitrarily set, for example, duplication control information indicating that two generations of duplication are possible or three generations of duplication is possible in the output information signal. Even if the copy control information indicating that the information signal is output is a non-compliant electronic device, the number of generations that can be copied is not subtracted but “No More Cop” is subtracted.
and outputs an information signal to which copy control information indicating "y" or copy control information indicating "copy prohibited" is added.

In this case, if the information signal can be copied for a plurality of generations, and the information signal is copied by a non-compliant electronic device, the information signal is further copied. Can be prohibited, so that it is possible to prevent a large number of recording media recording information signals that can be copied for a plurality of generations. Thereby, the copyright of the information signal that can be copied for a plurality of generations can be more reliably protected.

Further, as described above, the present invention can be applied to both analog output and digital output. Therefore, even if analog or digital equipment is used, the generation of copy can be reliably and appropriately performed. Duplication control including restriction control can be performed.

In the above-described embodiment, in the case of analog output, copy control information superimposed on a video signal (information signal) is used as digital watermark information, and in the case of digital output, CGMS- Although D is used, it is not limited to this.

In the case of digital output, copy control information superimposed on a video signal (information signal) may be used as digital watermark information. In the case of analog output, CGMS copy for analog signals is performed. CGMS-A which is control information (the letter "A" after-(hyphen) means analog) may be used. Further, both the copy control information superimposed on the video signal (information signal) and the CGMS information may be used as the digital watermark information.

Further, the present invention can be applied to a case where various copy control information capable of generation restriction control is used in addition to copy control information and CGMS information used as digital watermark information.

Further, in the above-described embodiment, the digital watermark information is obtained by spectrum-spreading the copy control information and the device information. However, the digital watermark processing is not limited to the one using the spread spectrum. Digital watermark information formed by various types of digital watermark processing can be used.

In the above embodiment, in the case of digital output, the device information of the output destination of the information signal is obtained using the function of the digital interface of the IEEE1394 standard. In the case of analog output or serial transmission of digital data, the same transmission line for transmitting information signals is used.
Device information is transmitted in the opposite direction to the information signal.

However, the transmission of the device information is not limited to the above-described embodiment. For example, a dedicated line for transmitting the device information for authentication may be used, or the device information may be transmitted wirelessly. Or various methods such as using one transmission line in a time-division manner.

In the above-described embodiment, whether or not a counterpart device is connected is detected based on the detection of the impedance of the transmission line or the voltage level of the signal on the transmission line. Absent. For example, connection of a transmission line to an output terminal or an input terminal may be mechanically detected.

[0247]

As described above, according to the present invention, even if a non-compliant electronic device is interposed,
It is possible to appropriately limit the generation of the information signal whose copy generation is restricted. Therefore, it is possible to appropriately protect the copyright of the information signal whose copy generation is restricted.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration example of an information signal output device that superimposes copy control information as electronic watermark information on an information signal to be output.

FIG. 2 is a block diagram for explaining a timing signal generator 132 shown in FIG.

FIG. 3 is a diagram for explaining digital watermark information and an information signal on which the digital watermark information is superimposed.

FIG. 4 is a block diagram for explaining a set-top box to which an embodiment of the information signal transmitting apparatus according to the present invention is applied;

FIG. 5 is a block diagram for explaining a WM detection unit 42 of the set-top box shown in FIG.

FIG. 6 shows an analog V that is a compliant recording device.
It is a figure for explaining TR.

FIG. 7 is a flowchart for explaining the operation of the set-top box shown in FIG.

FIG. 8 is a diagram for explaining a case where a compliant recording device is connected to the set-top box shown in FIG. 4 and a case where a non-compliant recording device is connected.

9 is a block diagram for explaining another example of the device information transmitting section 63 of the VTR 3 shown in FIG.

10 is a device information detection unit 45 of the STB 2 shown in FIG.
FIG. 10 is a block diagram for explaining another example of FIG.

FIG. 11 is a block diagram for explaining another example of a set-top box to which an embodiment of the information signal transmitting apparatus according to the present invention is applied.

FIG. 12 is a diagram for explaining another example of an analog VTR that is a compliant recording device.

FIG. 13 is a diagram for describing a case in which device information is transmitted by digital serial.

FIG. 14 is a diagram for describing detection of device information transmitted by digital serial transmission.

FIG. 15 is a diagram illustrating a case where a plurality of electronic devices are connected to a set-top box as an information signal transmission device.

[Explanation of symbols]

2 set-top box, 31 antenna, 32 tuner section, 33 de-scramble section, 34 de-multiplex section, 35 encryption section, 36 CGMS-D
Rewriting unit, 37 ... Digital interface of IEEE1394 standard, 38 ... Digital output terminal, 39 ... CG
MS-D decoding unit, 40 ... data compression / decompression unit, 41 ...
D / A converter, 42: WM (digital watermark information) decoder, 43: WM rewriter, 44: analog output terminal,
45: device information detecting unit, 46: connection detecting unit, 47: request sending unit, 50: control unit, 3: VTR (compliant recording device), 61: analog input terminal, 62
... Connection detection unit, 63 ... Device information transmission unit, 64 ... WM rewriting unit, 65 ... Record control unit, 66 ... WM (digital watermark information) decoding unit, 67 ... Request detection unit, 70 ... Control unit

 ──────────────────────────────────────────────────続 き Continued on the front page F-term (reference)

Claims (39)

[Claims] 1. An information signal transmission method to which duplication control information for limiting generation of duplication is added, wherein an electronic device that outputs the information signal is a partner device that is an output destination of the information signal. From the other device, the other device is a device that cannot support the copy generation restriction method based on the copy control information added to the information signal, and the copy control information is N ( N
Is an integer equal to or greater than 1) when the copy control information indicates that the copy is possible. And transmitting an information signal. 2. The apparatus according to claim 1, wherein the destination device that outputs the information signal has a function of transmitting information indicating an operation state of the destination device as the device information. 2. The information signal transmission method according to claim 1, wherein the method is performed when the device is a recording device and is in a recording state. 3. The information signal transmission method according to claim 1, wherein the copy control information is transmitted as electronic watermark information by being superimposed on the information signal. 4. The device according to claim 1, wherein the destination device that outputs the information signal transmits the device information when detecting that an electronic device is connected to the destination device. Or the information signal transmission method according to claim 3. 5. The electronic device as an output source of the information signal,
5. The information signal transmission method according to claim 1, wherein the device information is detected when it is detected that an electronic device is connected to the own device. 6. The electronic device as an output source of the information signal,
6. The information signal transmission method according to claim 1, wherein the information signal is output after the device information is detected. 7. The device according to claim 1, wherein said destination device to which said information signal is output always sends said device information. Or the information signal transmission method according to claim 6. 8. The device according to claim 1, wherein said destination device which outputs said information signal transmits said device information at intervals. The information signal transmission method according to claim 5. 9. An electronic device which outputs the information signal transmits a request for transmitting the device information, and the counterpart device which is an output destination of the information signal transmits the device information in response to the request for transmission. 3. The method according to claim 1, wherein the transmission is performed.
The information signal transmission method according to claim 3 or claim 6. 10. The device to which the information signal is output supplies the device information as a signal of a level smaller than that of the information signal to a transmission line for transmitting the information signal. Claim 1, Claim 2, Claim 3,
The information signal transmission method according to claim 5, claim 6, claim 7, claim 8, or claim 9. 11. The information signal transmission method according to claim 10, wherein the destination device to which the information signal is output sends the device information as digital watermark information. 12. The destination device of the information signal, wherein the counterpart device does not process the information signal transmitted through the transmission line when transmitting the device information. Claim 10 or Claim 1
2. The information signal transmission method according to 1. 13. A first electronic device serving as an output source of an information signal for transmitting an information signal to which copy control information for limiting generation of duplication is added, and a first electronic device for receiving the information signal. An information signal transmission system formed by connecting to a second electronic device serving as an output destination, wherein the second electronic device includes device information transmitting means for transmitting device information relating to the second electronic device, and (1) an electronic device, device information detection means for detecting the device information, copy control information detection means for detecting the copy control information added to the information signal, and the copy added to the information signal. A copy control information rewriting means for rewriting control information; and, based on a detection output of the device information detection means, an electronic device to which the information signal is output cannot support a copy generation restriction method based on the copy control information. If the duplication control information detected by the duplication control information detecting means indicates N-generation duplication possible, the duplication control information rewriting means is controlled to copy the duplication control information. An information signal transmission system comprising: rewriting control means for rewriting data with a reduced number of generations. 14. The device information transmitting means of the second electronic device has a function of transmitting operation state information indicating an operation state of the device itself, and the device information of the first electronic device. The detection means can also detect the operation state information, and the rewrite control means of the first electronic device, based on a detection output from the device information detection means, When it is determined that the device is a recording device and that the device is in a recording state, the device controls the copy control information rewriting means to rewrite the copy control information to a device with a reduced number of copyable generations. The information signal transmission system according to claim 13, wherein: 15. The duplication control information is superimposed on the information signal as digital watermark information, and the duplication control information detecting means and the duplication control information rewriting means perform the duplication with the digital watermark information. The information signal transmission system according to claim 13, wherein the information signal transmission system is capable of responding to control information. 16. The second electronic device further comprises connection detection means for detecting whether or not the electronic device is connected to itself, and the device information sending means of the second electronic device comprises: 16. The information according to claim 13, wherein the connection detection unit of the electronic device transmits the device information when detecting that the electronic device is connected to the own device. Signal transmission system. 17. The first electronic device includes connection detection means for detecting whether or not an electronic device is connected to the first electronic device, and the device information detection means of the first electronic device includes: 13. The device according to claim 13, wherein the connection detection unit of the electronic device detects the device information when detecting that the electronic device is connected to the own device.
The information signal transmission system according to claim 5 or 16. 18. The apparatus according to claim 13, wherein said first electronic device outputs said information signal after detecting said device information by said device information detecting means. 15. The information signal transmission system according to claim 16 or claim 17. 19. The apparatus according to claim 13, wherein said device information transmitting means of said second electronic device always transmits said device information.
An information signal transmission system according to claim 17 or claim 18. 20. The apparatus according to claim 13, wherein said apparatus information transmitting means of said second electronic apparatus supplies said apparatus information to said transmission line at intervals. 19. The information signal transmission system according to claim 16, claim 17, or claim 18. 21. The first electronic device comprises request sending means for sending a request for sending the device information; the second electronic device comprises request detecting means for detecting the sending request; The device information transmitting means of the second receiving device, when the request detecting means detects the transmission request,
14. The device according to claim 13, wherein the device information is transmitted.
An information signal transmission system according to claim 14, claim 15, or claim 18. 22. The device information transmitting means of the second electronic device supplies the device information as a signal having a level smaller than that of the information signal to a transmission line for transmitting the information signal. The information signal transmission system according to claim 13, claim 14, claim 15, claim 17, claim 18, claim 19, claim 20, or claim 21. 23. The information signal transmission system according to claim 22, wherein said device information transmitting means of said second electronic device transmits said device information as digital watermark information. 24. The second electronic device, wherein the device information sending means does not perform processing on the information signal supplied through the transmission line when the device information sending means is sending the device information. Claim 22 or Claim 2
3. The information signal transmission system according to 3. 25. An information signal transmitting apparatus for transmitting an information signal to which duplication control information for limiting generation of duplication is added, wherein the apparatus detects device information from an electronic apparatus to which the information signal is output. Information detection means; copy control information detection means for detecting the copy control information added to the information signal; copy control information rewriting means for rewriting the copy control information added to the information signal; From the detection output of the information detection means, the electronic device of the output destination of the information signal is a device that can not support the copy generation restriction method by the copy control information, the copy control information detected by the copy control information detection means, If it indicates that N generations can be copied, the copy control information rewriting means is controlled to reduce the number of generations in which the copy control information can be copied. An information signal transmitting device comprising: rewriting control means for rewriting data. 26. An electronic device to which the information signal is output, wherein operating state information indicating an operating state of the own device is included in the device information and transmitted. The means can also detect the operating state information from the electronic device to which the information signal is output, and the rewriting control means of the information signal transmitting device includes a detection output from the device information detecting means. Based on the above, when it is determined that the electronic device to which the information signal is to be output is a recording device, and that the electronic device is in a recording state, the duplication control information rewriting means is controlled to copy the duplication control information. 26. The information signal transmitting apparatus according to claim 25, wherein the information signal is rewritten with a reduced number of generations. 27. The copy control information is superimposed on the information signal as digital watermark information, and the copy control information detecting means and the copy control information rewriting means are adapted to copy the digital watermark information 27. The information signal transmitting apparatus according to claim 25, wherein the information signal transmitting apparatus can correspond to control information. 28. Connection detecting means for detecting whether or not an electronic device is connected to the own device, wherein the device information detecting means detects that the electronic device has been connected to the own device. 27. The apparatus according to claim 25, wherein the apparatus information is detected.
28. The information signal transmitting device according to claim 27. 29. An apparatus according to claim 25, wherein said information signal is outputted after said apparatus information detecting means detects said apparatus information transmitted through said transmission line. 29. The information signal transmission device according to claim 28. 30. The information signal transmitting apparatus according to claim 25, further comprising a request transmitting means for transmitting the device information transmitting request. 31. An information signal receiving apparatus for receiving an information signal to which duplication control information for limiting generations of duplication is added, comprising: a device information transmitting means for transmitting device information relating to its own device. Characteristic information signal receiving device. 32. An information signal receiving apparatus according to claim 31, wherein said apparatus information transmitting means can also transmit operation state information indicating an operation state of the apparatus. 33. Connection detecting means for detecting whether or not an electronic device is connected to the own device, wherein the device information transmitting means detects when the connection detecting device detects that an electronic device is connected to the own device. And transmitting the device information to the device.
3. The information signal receiving device according to 2. 34. The information signal receiving apparatus according to claim 31, wherein said device information transmitting means always transmits said device information. 35. The apparatus according to claim 3, wherein the device information transmitting means transmits the device information at intervals.
An information signal receiving apparatus according to claim 1 or claim 32. 36. An electronic device as an information signal output source, wherein a transmission request for the device information is transmitted, and a request detection unit for detecting the transmission request is provided. 33. The information signal receiving apparatus according to claim 31, wherein the device information is transmitted when the transmission request is detected by the request detection unit. 37. The apparatus according to claim 31, wherein said apparatus information transmitting means supplies said apparatus information as a signal having a level smaller than that of said information signal to a transmission line for transmitting said information signal. Claim 32, Claim 33, Claim 34,
An information signal receiving apparatus according to claim 35 or claim 36. 38. The information signal receiving apparatus according to claim 37, wherein said device information transmitting means transmits said device information as digital watermark information. 39. The apparatus according to claim 37, wherein the device information transmitting means does not perform processing on the information signal supplied through the transmission line when transmitting the device information. An information signal receiving device according to claim 1.