JPH01152880A - Video signal recording and reproducing device - Google Patents

Abstract

PURPOSE:To attain strong protect effect by providing a scrambling means applying scramble to picture information to a recording system and providing a descrambling means applying descrambling corresponding to the scramble by a specific command only to the reproducing system. CONSTITUTION:A picture signal scrambled by a scrambler 36 is converted into a form of a recording signal by a recording processing circuit 38, mixed with a recording audio signal by a mixer 40, applied to heads 44A, 44B by a gate circuit 42 and recorded on a prescribed location of a magnetic tape 46. A descrambler 66 applies opposite processing to a scrambler 36. A pattern ROM 76 stores the same content as the pattern ROM 26. A descrambler 66 converts a video signal from a reproduction processing circuit 62 into a digital signal by an A/D converter 68 and writes the result to a picture memory 70 sequentially.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a video signal recording and reproducing device, and more specifically to a video signal recording and reproducing device that can reproduce recorded video only under specific conditions. .

[Conventional technology]

If you do not want anyone other than a specific person to view image information recorded on a recording medium, you must use some method to prevent reproduction. Figure 3 shows the recording pattern of the magnetic tape of a helical scan type VTR. In the conventional prevention method, the video signal is recorded in the video signal recording area as usual, and various types of information accompanying the video signal are recorded. information (e.g. digitized audio signal)
A signal indicating whether the video area 10 can be played back is recorded in the recording area 12 of the video area 10, and during playback, the video area 1 is
Sometimes it played 0, sometimes it didn't.

[Problem that the invention seeks to solve]

However, in this conventional method, since the video signal is recorded in the video area 10 regardless of the reproduction permission information in the accompanying information recording area 12, if the reproduction permission information in the accompanying information recording area 12 is ignored. , video area 1
It has the disadvantage that it can reproduce 0 signals.

SUMMARY OF THE INVENTION Therefore, it is an object of the present invention to provide a video signal recording and reproducing apparatus that cannot reproduce recorded video even if only the recorded signal in the video area is reproduced.

[Means for solving problems]

In the video signal recording and reproducing apparatus according to the present invention, the recording system is provided with a scrambling means for scrambling image information, and the reproducing system is configured to perform descrambling corresponding to the scrambling by the scrambling means only in accordance with a specific instruction. The present invention is characterized in that it is provided with a descrambling means capable of.

[Operation] With the above means, the video signal itself recorded on the recording medium is scrambled, so even if the video signal itself is reproduced, the original image cannot be observed. Further, since the operation of the descrambling means corresponding to the above-mentioned scrambling is performed only in response to a specific instruction, only a specific person can view the original image.

〔Example〕

Hereinafter, one embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows a block diagram of the structure of a recording system of an embodiment in which the present invention is applied to a so-called 8 mm VTR, and FIG. 2 shows a block diagram of the structure of a reproduction system thereof.

In FIG. 1, an original image signal input to a video input terminal 20 is converted into a digital signal by an A/D converter 22 and written into an image memory 24. pattern ROM
Several patterns for scrambling are stored in 26, and the user specifies any one of the patterns using a pattern specifying device (for example, a numeric keypad) 28.

Specifically, the system controller 30 selects the pattern ROM 2 according to the designation signal from the pattern designation device 28.
6, the memory successive/write control circuit 32 is controlled so that the storage signals of the memory 24 are read out in the address order according to the selected scrambling pattern. Of course, the signals from the A/D converter 22 may be written into the memory 24 in the address order according to the selected scrambling pattern, and the subsequent output from the memory 24 may be performed in the address order. The output of the memory 24 is converted back to an analog signal by a D/A converter 34. A/D converter 22, memory 24
, pattern ROM 26, memory succession/write control circuit 32
and the D/A converter 34 constitute a scrambler 36.

The image signal scrambled by the scrambler 36 is converted into a recording signal form by a recording processing circuit 38, mixed with a recording audio signal to be described later by a mixer 40, and applied to heads 44A and 44B by a gate circuit 42. It is recorded at a predetermined location on the magnetic tape 46.

As is well known, the audio signals input to the audio input terminals 48A and 48B are subjected to FM modulation in an FM modulation circuit 50 and mixed with a recorded video signal in a mixer 40. The input audio signal is also supplied to the PCM processing circuit 52 and converted into a PCM audio signal. Since these effects are well known, further explanation will be omitted.

Information about which scrambling pattern has been selected is applied from the system controller 30 to the PCM processing circuit 52. The scramble pattern information is added to the audio data as ID data, and is sent to the gate circuit 42.
and head 44A.

The information is recorded at a predetermined location on the magnetic tape 46 via the magnetic tape 44B.

FIG. 2 will be explained. From the magnetic tape 46 to the head 54A,
The signal reproduced by 54B is distributed to a video/audio separation circuit 58 and a PCM processing circuit 60 by a gate circuit 56 according to the recording area. That is, video
The recording signal of the area is supplied to the video/audio separation circuit 58, and the recording signal of the PCM code area is supplied to the PCM processing circuit 60. The video/audio separation circuit 58 separates the video signal and the FM audio signal,
The video signal is applied to a reproduction processing circuit 62 and the FM audio signal is applied to an FM demodulation circuit 64. The video signal reproduced by the reproduction processing circuit 62 is applied to a descrambler 66.

The descrambler 66 includes an A/D converter and an image memory 70.
, a D/A converter 72, a memory readout/write control circuit 74 that controls reading and writing of the image memory 70, and a pattern RO that stores information regarding the scramble pattern.
It consists of M76 and performs processing opposite to that of the scrambler 36 in FIG. The pattern ROM 76 is pattern R in FIG.
Stores the same contents as OM26. In the descrambler 66, the video signal from the reproduction processing circuit 62 is converted into a digital signal by an A/D converter 68, and sequentially written into the image memory 70. On the other hand, the system controller 78
The scrambling information at the time of recording is received from the M processing circuit 60, and the scrambling pattern is checked by the pattern ROM 76. Then, according to the determined scramble pattern, the memory successive/write control circuit 74 is controlled to read the stored data from the memory 70 in the order in which the scrambled image is returned to the original image. The output data of the memory 70 is converted into an analog signal by the D/A converter 72 and sent to the video output terminal 8.
Output to 0.

The audio signal FM demodulated by the FM demodulation circuit 64 and the output of the PCM processing circuit 60 are applied to the gate circuit 82 . Gate circuit 82 outputs audio signals to audio output terminals 84A and 84B under the control of system controller 78.

An example of a scramble pattern is shown in FIG.

FIG. 4(a) shows how the data is arranged when the original image is written into the memory 24, with the IH-th data at address O, the data at addresses 1 and 2H, and so on. . Figure 4~) shows the order in which data is read after applying °--su winter ripple, first reading the IH-th data at address O, then reading from address 131.
The 132nd H data is read out, and the memory successive access/write control circuit 32 is controlled in the following manner.

As described above, by arbitrarily scrambling the video signal itself and performing corresponding descrambling during playback, a proper original image can be played back and displayed. The so-called protect operation that does not allow descrambling to function will be explained.

When recording, a user's code is inputted from the code input device (for example, numeric keypad) 90 shown in FIG.
are simultaneously recorded on the magnetic tape 46 as ID words. During playback, the same code is input from the code input device (for example, numeric keypad) 92 shown in FIG. System controller 78 compares the cipher to the ID word in the playback signal.

If the codes match, switch 94 is closed to enable input of scrambling pattern information from PCM processing circuit 60 to system controller 78. If the codes do not match, switch 94 is opened to prevent the scrambling pattern information from being input to system controller 78, thereby disabling descrambling. When descrambling is disabled, a video signal of a scrambled image is output to the video output terminal 80. Instead of opening and closing the switch 94, the control method of the memory successive/write control circuit 74 may be changed depending on whether the codes match or do not match.

By doing this, people who do not know the code will not be able to view the original picture before it is scrambled. This code is
The scrambling pattern selection number itself may be configured as a code. In that case, there is no need to provide a separate code.

〔Effect of the invention〕

As can be easily understood from the above description, according to the present invention, the original picture cannot be reproduced just by reproducing the video signal itself recorded on the recording medium, so that a strong protection effect can be achieved.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a recording system according to an embodiment of the present invention.
FIG. 2 is a block diagram of the structure of the reproduction system, FIG. 3 is a magnetic recording pattern of an 8 mm VTR, and FIG. 4 is an example of scrambling by the recording system of FIG. 1. 20...Video input terminal 26.7 RO1 pattern RO
M 28-・Pattern information input device 30.78・・
-System controller 36-・Scrambler 48
A, 48B-Audio input terminal 50...-FM modulation circuit 58-Video/audio separation circuit 66--
Descrambler 80-/Video output terminal 84A,
84B-Audio output terminal 90°92・-Encryption input device

Claims (1)

[Claims] The recording system is provided with a scrambling means for scrambling image information, and the reproduction system is provided with a descrambling means that can perform descrambling corresponding to the scrambling by the scrambling means only in accordance with a specific instruction. A video signal recording and reproducing device characterized by: