JP3780924B2 - Digital information transmission method and recording / reproducing method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a digital information signal transmission method and recording / reproduction method , and more particularly, to a digital information transmission method and recording method in which control information is added to an information signal for transmission or recording, and reception or reproduction is performed using the additional information. It relates to a playback method .
[0002]
[Prior art]
Audio and video software as described in the Journal of the Institute of Television Engineers of Japan, Vol. 47, No. 4 (1993), pages 494 to 497, is transmitted via radio waves and cables, and recorded at home. The system is considered.
[0003]
[Problems to be solved by the invention]
When selling and renting audio and video software using the above-described conventional technology, there is a problem that the sales destination, the number of rental days, and the like must be managed.
[0004]
An object of the present invention is to provide a digital information transmission method and a recording / reproducing method capable of solving such problems and easily managing a sales destination, rental days, and the like.
[0005]
[Means for Solving the Problems]
In order to achieve the above object, the present invention transmits a digital information signal that has been made secret, and secret information for releasing the digital information signal. Recording the transmitted digital information signal; A digital information recording / reproducing method for canceling secretization of the digital information signal by the transmitted secret information at the time of reproducing the recorded digital information signal, wherein the secret information is recorded when the digital information signal is recorded. When the digital information is transmitted and a predetermined period has elapsed, the digital information signal is received by not transmitting the secret information corresponding to the digital information. After a predetermined period of time has elapsed, the recorded digital information signal cannot be unlocked.
[0006]
The present invention also relates to a digital information transmission method for transmitting a digital information signal that has been made secret to the information recording / reproducing apparatus and secret information for releasing the secret information from the digital information signal. Is for recording the transmitted digital information signal and releasing the digital information signal by using the transmitted confidential information when reproducing the recorded digital information signal, and transmitting the digital information. After a predetermined period has elapsed, the transmission of the secret information corresponding to the digital information is not transmitted to the information recording / reproducing apparatus, so that the predetermined period has elapsed after receiving the digital information signal. In such a case, the recorded digital information signal cannot be unlocked.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings.
[0008]
FIG. 1 is a block diagram showing an embodiment of a digital information recording / reproducing apparatus according to the present invention. The apparatus is roughly divided into a transmission system 100, a reception system 200, and a recording / reproduction system 300, where 1 is an input terminal and 10 is a transmission. System encoder, 20 is a time axis compressor, 25 is a modulator, 30 is a transmission path, 35 is a demodulator, 40 is a recording system encoder, 45 is a switching switch, 50 is a rotating drum, 51a and 51b are magnetic heads, 60 is a magnetic tape, 70 is a reproduction system decoder, 80 is a reception system decoder, and 9 is an output terminal. In the magnetic heads 51a and 51b, (+) indicates positive azimuth and (-) indicates negative azimuth.
[0009]
In the figure, the operation of the transmission system 100 is such that the digital information signal input from the input terminal 1 is encoded in a predetermined format by the transmission system encoder 10 and 1 / n (in the present invention, by the time axis compressor 20). , N is set to an integer of 2 or more), and the transmission rate is increased by a factor of n, modulated by the modulator 25, and sent to the transmission line 30.
[0010]
In the receiving system 200, the signal received via the transmission path 30 is demodulated by the demodulator 35, and the demodulated signal is directly recorded in the recording system encoder of the recording / reproducing system 300 in a state where it is encoded in the transmission system. 40. The recording encoder 40 records and encodes the supplied signal in a format suitable for recording and reproduction.
[0011]
FIG. 2 is a block diagram showing a configuration example of the recording system encoder 40, in which 41 is a storage circuit, 42 is an interface circuit, 43 is a parity generation circuit, 44 is a recording signal generation circuit, and 301 is control information generation. Circuit. In the figure, the data demodulated by the demodulator 35 of the receiving system 200 is first stored in the storage circuit 41 via the interface circuit 42. FIG. 3A shows this demodulated data. The parity generation circuit 43 generates a parity from the demodulated data stored in the storage circuit 41 and stores it in the storage circuit 41. The recording signal generation circuit 44 reads the demodulated data and parity stored in the storage circuit 41, adds an ID signal and a synchronization signal made up of control information generated by the control signal generation circuit 301, and the like in FIG. It is output as a block format signal as shown. FIG. 4 shows an example of the configuration of an ID signal. For example, a track number for identifying a recording track, a block number for identifying a position in the track, control information, and error detection and correction of the ID signal. Because of the parity.
[0012]
The signals encoded in this manner are supplied to the magnetic heads 51a and 51b attached to the rotary drum 50 at positions opposite to each other by 180 degrees via the switching switch 45, and azimuthally recorded on the magnetic tape 60. . FIG. 5 shows a track pattern at this time. The rotational speed of the rotating drum 50 and the traveling speed of the magnetic tape 60 are set to R1 and V1, as in the conventional case, P is the track pitch, and W is the head width of the magnetic heads 51a and 51b. In this embodiment, the head width W is larger than the track pitch P, for example, 1.5 times.
[0013]
At the time of reproduction, the rotating drum 50 is rotated at the same speed R1 as at the time of recording, and the magnetic tape 60 is run at the speed V1 / n at the time of recording, and the recorded signal is reproduced by the magnetic heads 51a and 51b. . FIG. 6 is a diagram showing a track pattern at the time of reproduction. A solid line shows a recorded track pattern, and a broken line shows scanning trajectories of the magnetic heads 51a and 51b. Thus, since the rotating drum 50 is rotated at the same speed R1 as that during recording and the magnetic tape 60 is driven at a speed 1 / n of 1 / n during recording, the scanning pitch of the magnetic heads 51a and 51b is as follows. The track pitch P is 1 / n, and the scanning angle is slightly shifted, but scanning is performed n times per track. In this embodiment, n is set to 3 to simplify the description. W indicates the head width of the magnetic heads 51a and 51b. Normally, the head width (W) is larger than the track pitch (P), for example, 1.5 times.
[0014]
FIG. 7 shows the structure of the control signal. The program number is information indicating the program number in the tape, and the time information is information indicating the elapsed time in the tape and in the program. The type is information indicating a type such as whether the digital information signal to be recorded is sold or rented. This information may be further subdivided according to whether the sold information is sold only to a specific user, the number of days to rent, or the like. The recording date and time is the recording date and time, and the user number is the registered user registration number, and is stored in the receiving system 200 or the recording / reproducing system 300.
[0015]
Redundancy can be reduced by recording control information distributed over a plurality of blocks. Further, as shown in FIG. 8, it may be recorded in a different area from the digital information signal. In this case, the control information may be recorded in the same block configuration as the digital information signal recording area and in the portion where the demodulated data in FIG. 3B is recorded. Note that the reliability of the control information can be improved by multiple writing.
[0016]
When receiving a digital information signal sales or rental service, when a user makes an application for a transmission source, the transmission source transmits a digital information signal together with a user number and additional information indicating the type of sales or rental. On the receiving side, the user number in the additional information is identified in the receiving system 200 or the recording / reproducing system 300, and if it matches, the information is recorded. At this time, the type of sale or rental is identified from the additional information and recorded as information indicating the type in the control information.
[0017]
FIG. 9 is a block diagram showing an example of the configuration of a playback system decoder 70 that performs processing of the entire playback system. Reference numeral 71 denotes a memory circuit, 72 denotes a block reproduction circuit, 73 denotes an error correction circuit, 74 denotes a reproduction signal output circuit, and 302 denotes a control signal detection circuit. In the figure, signals reproduced by the magnetic heads 51 a and 51 b are first input to a block reproduction circuit 72. The block reproduction circuit 72 detects the synchronization signal and the ID signal, and stores them in a predetermined position on the storage circuit 71 from the track number and block number in the ID signal. The error correction circuit 73 corrects an error in the reproduction data using the parity stored in the storage circuit 71, and simultaneously generates a pointer indicating the error state and stores it in the storage circuit 71. At this time, the data of the same track number and block number are inputted n times into the storage circuit 71, but the data with the best error state is finally stored by the pointer. The reproduction signal output circuit 74 reads out the data after error correction processing stored in the storage circuit 71 according to the order of the track number and the block number, and outputs the low-speed data expanded in the time axis.
[0018]
The low-speed data signal subjected to the reproduction system decoding process in this manner is sent to the reception system 200, and the reception system decoder 80 decodes the encoding in the transmission system. Then, the signal decoded into the original digital information signal is output from the output terminal 9.
[0019]
As described above, the reception decoder 80 may be low-speed processing by being arranged not in front of the recording / reproducing unit 300 but in the rear.
[0020]
The control signal detection circuit 302 determines whether to perform reproduction by identifying control information. For example, in the case of sold information, when the user number matches according to the sales form, that is, it can be played back only on the recorded device and cannot be played back on other devices. In the case of rented information, the recording date and time and the rental period are compared, and if the rental period has expired, it cannot be reproduced. Note that this control may be performed by the reception system 200. In this case, the control signal reproduced by the recording / reproducing system 300 is output to the receiving system 200.
[0021]
FIG. 10 is a block diagram showing another embodiment of the digital information recording / reproducing apparatus according to the present invention, which is an example in which the present invention is applied to a system in which video software is transmitted in secret and recorded and reproduced only by subscribers. . In the figure, 15 is a scrambler, 52a and 52b are magnetic heads, 75 is a descrambler, 101, 102 and 103 are input terminals, 111 and 112 are A / D converters, 121 and 122 are information amount compressors, 201 , 202 are information amount expanders, 211 and 212 are D / A converters, 221, 222, and 223 are output terminals, and portions corresponding to those in FIG. In the magnetic heads 52a and 52b, (+) indicates positive azimuth and (-) indicates negative azimuth.
[0022]
In the transmission system 100, the image signal input from the input terminal 101 is A / D converted by the A / D converter 111, and the information amount is compressed to an appropriate rate by the information amount compressor 121. The audio signal input from the input terminal 102 is A / D converted by the A / D converter 112, and the information amount is compressed to an appropriate rate by the information amount compressor 122. These A / D converted image signals and audio signals are time-division multiplexed and encoded by the transmission system encoder 10 together with the independent data input from the input terminal 103, and are then encoded by the scrambler 15. Secret story. Hereinafter, this secret signal is time-axis compressed to 1 / n by the time-axis compressor 20, modulated by the modulator 25, and sent to the transmission line 30 as in the embodiment of FIG.
[0023]
In the receiving system 200, as in the embodiment of FIG. 1, the signal received via the transmission path 30 is demodulated by the demodulator 35 and demodulated data is supplied to the recording system encoder 40 of the recording / reproducing system 300.
[0024]
In the recording / reproducing system 300, the supplied demodulated data is recorded and encoded by the recording system encoder 40, and supplied to the two sets of magnetic heads 51 a, 51 b, 52 a, 52 b through the switching switch 45, and applied to the magnetic tape 60. 2 channel azimuth recording. The recording frequency can be reduced to ½ by two-channel recording using the two sets of magnetic heads 51a, 51b, 52a, and 52b. The rotational speed of the rotating drum 50 and the traveling speed of the magnetic tape 60 are set to R2, V2, for example.
[0025]
At the time of reproduction, the rotating drum 50 is rotated at the same speed R2 as at the time of recording, and the magnetic tape 60 is run at a speed V2 / n of 1 / n at the time of recording, and the recorded signal is sent to a pair of magnetic heads 51a and 51b. To play. In this embodiment, the time-axis compression coefficient n is set sufficiently large (originally, it is desirable that n is larger), and n / 2 times per track even in one-channel reproduction by one set of magnetic heads 51a and 51b. Since tracing is possible, sufficient data reproduction is possible by performing the same processing as in the embodiment of FIG. As a result, there is an effect that a single reproduction system circuit is required and the circuit scale can be reduced.
[0026]
In the reception system 200, the signal decoded by the reproduction system decoder 70 is received, the signal that has been made secret in the transmission system is solved by the descrambler 75, and the signal encoded in the transmission system is decoded by the reception system decoder 80. Separate the image signal, audio signal and independent data. The separated image signal and audio signal are expanded to the original information amount by the information amount expanders 201 and 202, D / A converted by the D / A converters 211 and 212, and output from the output terminals 221 and 222, respectively. Is output. The separated independent data is output from the output terminal 223.
[0027]
FIG. 11 shows the configuration of the control signal in the embodiment of FIG. The scramble information is information necessary for descrambling. Usually, this information is stored in the receiving system 200. By storing this scramble information as control information and outputting the scramble information reproduced at the time of reproduction to the receiving system 200 for descrambling, the recorded information can be reproduced even if the scramble is changed. .
[0028]
In the case of rented information, if the scramble is changed periodically and the scramble information is not recorded in the control information, the information after a certain period cannot be descrambled. The rental period can be managed. In this case, although not shown, the descrambler is performed by the received scramble information stored in the reception system 200.
[0029]
【The invention's effect】
As described above, according to the present invention, it is possible to easily manage the rental period and the like.
[Brief description of the drawings]
FIG. 1 is a block diagram showing an embodiment of a digital information recording / reproducing apparatus according to the present invention.
FIG. 2 is a block diagram showing a configuration example of a recording system encoder according to the present invention.
FIG. 3 is a diagram showing input / output signals of the recording system encoder shown in FIG. 2;
FIG. 4 is a diagram illustrating a configuration example of an ID signal.
FIG. 5 is a diagram showing a track pattern during recording in the embodiment of FIG. 1;
6 is a diagram showing a track pattern at the time of reproduction in the embodiment of FIG. 1; FIG.
FIG. 7 is a diagram illustrating a configuration example of a control signal.
FIG. 8 is a diagram illustrating another embodiment of a control signal recording method;
FIG. 9 is a block diagram showing an example of the configuration of a reproduction system encoder according to the present invention.
FIG. 10 is a block diagram showing another embodiment of the digital information recording / reproducing apparatus according to the present invention.
FIG. 11 is a diagram illustrating a configuration example of a control signal in the embodiment of FIG. 10;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 ... Transmission system encoder, 15 ... Scrambler, 20 ... Time axis compressor, 25 ... Modulator, 35 ... Demodulator, 40 ... Recording system encoder, 41 ... Memory circuit, 42 ... Interface circuit, 43 ... Parity generation Circuit 44... Recording signal generation circuit 50... Rotating drum 51a 51b 52a 52b magnetic head 60 magnetic tape 70 reproduction decoder 71 71 storage circuit 72 block reproduction circuit 73 Error correction circuit, 74 ... reproduction signal output circuit, 75 ... descrambler, 80 ... reception decoder, 111, 112 ... A / D converter, 121,122 ... information amount compressor, 201, 202 ... information amount decompressor 211, 212, D / A converters, 301, control signal generation circuit, 302, control signal detection circuit.

Claims (2)

An encrypted digital information signal and an anonymized information for releasing the digital information signal are transmitted,
Recording the transmitted digital information signal;
A digital information recording / reproducing method for canceling the secrecy of the digital information signal by the transmitted secrecy information when reproducing the recorded digital information signal,
When recording the digital information signal, avoid recording the secret information,
When a predetermined period elapses after transmission of the digital information, and when a predetermined period elapses after receiving the digital information signal by not transmitting the secret information corresponding to the digital information The digital information recording / reproducing method is characterized in that it is impossible to cancel the secrecy of the recorded digital information signal. In a digital information transmission method for transmitting a digital information signal made secret to an information recording / reproducing apparatus and secret information for releasing the secret information of the digital information signal,
The information recording / reproducing apparatus records the transmitted digital information signal, and when reproducing the recorded digital information signal, releases the secret information of the digital information signal by the transmitted secret information,
After the digital information is transmitted, after a predetermined period has elapsed, the digital information signal is received by not transmitting the secret information corresponding to the digital information to the information recording / reproducing apparatus. A digital information transmission method characterized in that, after a predetermined period of time has passed, it is impossible to cancel the recording of the recorded digital information signal.

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