JP2002133775A - Digital signal recording/reproducing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve a problem that a digital signal recording/reproducing device may be possibly used in a very limit state for interchangeable reproduction, a device and a medium are used in an over-specification state so far as self- record/reproduction is concerned, and they must be used in a state that the performance of a head tape cannot be fully extracted. SOLUTION: When a medium judging means 13 judges the head tape as a VHS tape, or when a recording mode judging means 31 recognizes that a tape feed has a 19 μm track pitch and the tape is a D-VHS tape, a reproduction signal decoding means 34 generates key information based on the device individual information extracted from a deck 11 by a device individual information extracting means 32 and reproduces the data of the reproduction signal unformatted by a formatting means 33 while unlocking a key, i.e., only self- record/reproduction is feasible in this case. When the tape feed has a 29 μm track pitch and the tape is the D-VHS tape, the data can be reprodued regardless of the key information, thereby allowing interchangeable reproduction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a digital signal recording / reproducing apparatus, and more particularly to a digital signal recording / reproducing apparatus such as a D-VTR for recording a digital signal on a recording medium at a high density in a predetermined track format and reproducing the same. .

[0002]

2. Description of the Related Art In a digital signal recording / reproducing apparatus such as a D-VTR, a predetermined track format determined by using a high-density recording technique is not premised on recording / reproducing by one recording / reproducing apparatus. Generally, compatible playback between different devices is considered. In addition, digital signal recording / reproducing devices capable of recording a certain format take into account recording differences between devices, production variations, track bending during compatible playback, etc. In general, the medium to be used is limited so as to use a medium having sufficiently good recording and reproduction characteristics so as not to make a mistake.

[0003] In other words, when limited to self-recording / reproducing, the specified format has a margin more than necessary because of consideration for compatible reproduction, and is usually over-spec. If D-VHS (registered trademark) is taken as an example, a track pitch of 29 μm is
-Self-recording and re-recording on a VHS recommended tape means that there is ample room for it. Therefore, it is desirable to use the recording / reproducing mode at a track pitch of 19 μm only for self-recording / reproducing. Similarly, if the track pitch is limited to 29 μm, even if the tape is not a D-VHS recommended tape, it is desirable to record on a VHS tape and perform self-recording / reproduction.

[0004]

However, since a medium recorded on one device may be reproduced on another device, it is desirable to use a format that has a possibility of exhibiting insufficient characteristics in compatible reproduction. Absent. For this reason, although compatible reproduction may be used in a marginal state, if it is limited to self-recording and reproduction, the result is that both equipment and media will be used in an overspec state, and the performance of head and tape will be fully exploited. There is a problem that it has to be used without it. Further, although the medium and the head are good, there is a problem that the format and the medium are restricted in consideration of compatible reproduction, and as a result, the price of the medium becomes high.

[0005] The present invention has been made in view of the above points,
An object of the present invention is to provide a digital signal recording / reproducing apparatus capable of sufficiently extracting the characteristics of a medium in self-recording / reproducing without causing a problem of compatible reproduction.

Another object of the present invention is to provide a digital signal recording / reproducing apparatus which can use an inexpensive medium.

[0007]

In order to achieve the above object, the present invention provides a medium discriminating means for discriminating a type of a recording medium to be recorded and reproduced, and first key information based on identification information unique to a recording apparatus. Key information generating means for generating a digital signal, an encrypting means for encrypting a digital signal to be recorded using the first key information, a recording mode selected from a plurality of recording modes, and a medium discriminating means. When the combination with the type of recording medium determined by the above is the first combination, the digital signal encrypted by the encryption means is recorded on the recording medium, and when the combination is another second combination, Recording means for recording an unencrypted digital signal on a recording medium, and a second key for generating second key information based on second identification information unique to a device for reproducing the recorded digital signal on the recording medium. Information generator A recording mode discriminating means for reproducing a digital signal recorded on the recording medium to discriminate the recording mode; and a combination of the recording mode discriminated by the recording mode discriminating means and the type of the recording medium discriminated by the medium discriminating means. When the combination is 1, the encryption of the digital signal reproduced from the recording medium is decrypted using the second key information and decoded, and the recording mode determined by the recording mode determining means and the recording mode determined by the medium determining means are determined. When the combination with the type of the recording medium is the second combination, a configuration is provided in which decoding means is provided for decoding as is regardless of the second key information.

According to the present invention, when the combination of the selected recording mode and the type of the recording medium is the above-described first combination, the digital signal is converted into the first signal based on the identification information unique to the apparatus.
Is recorded using the key information described above, and when the recording medium is reproduced, the code is decrypted and decoded only when reproduced by the same device as the recording. That is, in the present invention,
In the case of the first combination, the recorded digital signal can be reproduced only by self-recording / reproducing. When the combination of the selected recording mode and the type of the recording medium is the second combination, the digital signal is recorded on the recording medium without encryption, and is decoded as it is during reproduction. In the case of the above second combination, compatible reproduction can be performed. As described above, according to the present invention, only the self-recording / playback is performed according to the combination of the selected recording mode and the type of the recording medium.
Or, compatible playback is possible.

According to the present invention, in order to achieve the above object, the recording mode of the first combination includes a long time recording a digital signal by forming a track at a track pitch narrower than the track pitch of the standard mode. Since the recording mode is set, a digital signal recorded in the long-time mode can be made only for self-recording and replay, and can not be compatiblely reproduced.

According to the present invention, in order to attain the above object, the type of the recording medium of the first combination is a type of recording medium whose characteristics are inferior to those of a predetermined type of recording medium. A digital signal recorded on a recording medium of inferior type can only be self-recorded and reproduced, and cannot be compatiblely reproduced.

Further, in order to achieve the above object, the present invention provides the above-mentioned first combination, wherein when the type of the recording medium is a predetermined type, the recording mode has a track pitch narrower than that of the standard mode. The digital signal recorded in the long-time recording mode is compatible with a predetermined type, which has excellent characteristics, because the long-time recording mode is used to record a digital signal by forming a track. I can do it.

According to the present invention, in order to achieve the above object, the second combination is a recording medium of a predetermined type and a standard recording mode.
Digital signals recorded on a standard type of recording medium with excellent characteristics and in a standard mode with a wider track pitch than the long-time recording mode can be either self-recorded or compatible. Can be.

[0013]

Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram of a recording system of an embodiment of a digital signal recording / reproducing apparatus according to the present invention. The recording system according to this embodiment includes a deck 11 which is a recording / reproducing mechanism for a magnetic tape, and a device individual information extracting unit 1.
2, a medium discriminating means 13, and a format means 14 for converting an input signal to be recorded into a signal of a predetermined format.
Recording mode setting means 15 and recording signal generating means 16
And a recording amplifier 17.

The recording signal generating means 16 includes an apparatus individual information extracting means 12, a medium discriminating means 13, and a formatting means 14.
It receives each signal from the recording mode setting means 15 as an input, generates a recording signal based on these signals, and outputs it to the recording amplifier 17. In this embodiment, D-VH
A recording system for recording a digital signal based on the S format will be described as an example.

First, when a cassette containing a magnetic tape, which is a recording medium, is inserted into the deck 11, the medium discriminating means 13 usually causes the magnetic tape to be D-VHS (registered) according to the presence or absence of a hole at a predetermined position of the cassette. (Trademark) tape. In addition, recording mode setting means 1
According to 5, the recording mode is 29 μm or 19 μm track pitch.
m. In addition, D-VHS tape is S-VH
It is the same as the S tape.

The medium discrimination means 13 determines that the magnetic tape is
When the recording signal is determined to be a VHS tape and the recording mode set by the recording mode setting means 15 is a 29 μm mode, the input signal is formatted by the formatting means 14 in the first format of the 29 μm mode to generate a recording signal. It is supplied to the means 16. At this time, the recording signal generating means 16
Irrespective of the device individual information from the device and the recording mode signal from the recording mode setting means 15, the recording digital signal input from the formatting means
To form a track with a track pitch of 29 μm on a magnetic tape.

The recording / reproducing mechanism itself of the deck 11 is well known in the art. The two rotating heads attached to the rotating drum 180 ° face each other, and the rotating rotating drum is inclined at an angle range of about 180 °. The input digital signal of the above-described first format is sequentially recorded on a magnetic tape running at a predetermined running speed while being wound at a track pitch of 29 μm with respect to the tape longitudinal direction. .

When the medium discriminating means 13 determines that the magnetic tape is D-VHS and the recording mode set by the recording mode setting means 15 is a mode with a track pitch of 19 μm, the formatting means 1
4, the input signal is formatted in the second format of the 19 μm mode and supplied to the recording signal generating means 16. At this time, the deck 11 is set in the recording mode setting means 15.
The magnetic tape is caused to travel at a traveling speed slower than that in the 29 μm mode, in which the recording mode set by (1) is set in the 19 μm mode.

At the same time, the device individual information extracting means 12 extracts the serial number uniquely assigned to the deck 11 from the deck 11 and outputs the recording signal generating means 16
To supply. The recording signal generating means 16 encrypts the digital signal of the second format input from the formatting means 14 using the key information generated from the device individual information (serial number) input from the device individual information extracting means 12. This is input to the deck 11 through the recording amplifier 17 as a recording digital signal, and a track having a track pitch of 19 μm is formed on the magnetic tape for recording.

The means for generating the key information in the recording signal generating means 16 is conventionally known, and has, for example, the configuration shown in the block diagram of FIG. This key information generation means supplies the identification signal generated by the identification signal generator 21 to the key generator 22 with the configuration disclosed in Japanese Patent Application Laid-Open No. 11-102572 to generate key information. The encryption processor 23 performs an encryption process on the input data using the key information described above, and outputs the obtained encrypted signal with the recording processor 24 adding an error correction code and the like.

When this key information generating means is applied to the present embodiment, the identification signal generator 21 shown in FIG. 2 corresponds to the device individual information extracting means 12 shown in FIG. (Number) corresponds to the above identification signal. The key generator 22, the encryption processor 23, and the recording processor 24 are provided inside the recording signal generating means 16, and encrypt the digital signal from the formatting means 14 with the key information, and then, generate an error correction code. Add and output.

FIG. 3 is a block diagram further showing the recording signal generating means 16. Referring to FIG.
The recording processing unit 18 includes a key generator 22 shown in FIG. 2, and a scrambler 19 comprises a cryptographic processor 23 shown in FIG.
A recording processor 24 is included. In FIG. 3, the formatted SYNC block data extracted from the formatting means 14 and the initial value load pulse are:
It is supplied to the scrambler 19.

On the other hand, the recording processing unit 18 outputs the lower 15 bits of the device individual information (serial number) of the deck 11 extracted by the device individual information extracting means 12 to the scrambler 19 as key information, where the initial value is output. Is exclusive-ORed with the initial value at the timing of loading. However,
When recording on a D-VHS tape at a track pitch of 29 μm, the recording processing unit 18 is forcibly reset so that the serial number becomes “0”, so that the scrambler 19 does not perform the scramble operation. .

Next, the operation when the medium discriminating means 13 discriminates that the magnetic tape of the insertion cassette is a VHS tape will be described. In this case, the VHS tape is D
Since the characteristics are considerably inferior to those of the -VHS tape, the track pitch is limited to the 29 μm mode regardless of the user setting. Thus, the input signal is formatted by the formatting means 14 in the first format of the 29 μm mode and supplied to the recording signal generation means 16.

At the same time, the device individual information extracting means 12 extracts the serial number uniquely assigned to the deck 11 from the deck 11 and outputs the recording signal generating means 16
To supply. The recording signal generating means 16 generates the first key information based on the serial number input from the apparatus individual information extracting means 12 by the method described with reference to FIGS. 2 and 3, and uses the first key information. After scrambled (encrypted) the recording digital signal of the first format inputted from the formatting means 14 through the recording amplifier 17, the recording digital signal is inputted to the deck 11 to form a track having a track pitch of 29 μm on a magnetic tape and record it. When recording digital signals, a fixed control head records a control pulse of a fixed cycle along the longitudinal direction of the tape regardless of the type of tape.

Next, the configuration and operation of the reproducing system will be described. FIG. 4 is a block diagram of a reproducing system according to an embodiment of the digital signal recording / reproducing apparatus according to the present invention. In the figure,
The same components as those in FIG. 1 are denoted by the same reference numerals. In FIG. 4, when a cassette containing a magnetic tape to be reproduced is loaded on the deck 11, the medium discriminating means 13 discriminates whether the magnetic tape in the cassette is a D-VHS tape or a VHS tape.

When the cassette is loaded on the deck 11 in parallel with the tape discriminating operation by the medium discriminating means 13, the deck 11 controls the control pulse recorded on the magnetic tape irrespective of self-recording / reproducing or compatible reproduction. The magnetic tape is run at the tape running speed determined by the interval, and the recording mode determining means 31 determines the recording mode. A recording mode discriminating method by the recording mode discriminating means 31 is conventionally known.

When the running speed of the magnetic tape is servoed in the same manner as during recording, and when the recording digital signal starts to be reproduced from the magnetic tape, the recording mode discriminating means 31 makes the tape feed 2
9 μm track pitch, and
When the medium discrimination means 13 discriminates that the tape is a D-VHS tape, the reproduction signal reproduced from the magnetic tape by the deck 11 and unformatted by the format means 33 uses the key information by the reproduction signal decoding means 34. The decoding is performed in a known manner without performing the decoding.

Further, the recording mode discriminating means 31 recognizes that the tape feed is of a track pitch of 19 μm,
On the other hand, if the medium discrimination means 13 determines that the tape is a D-VHS tape, the reproduction signal decoding means 34
Is device-specific information (serial number) unique to deck 11 extracted from deck 11 by device-specific information extracting means 12
To generate a key from this device individual information,
The data is reproduced while releasing the key from the reproduction signal unformatted by the formatting means 33.

Here, as the key release means of the reproduction signal decoding means 34, for example, the configuration disclosed in Japanese Patent Application Laid-Open No. H11-102572 can be used.
And a reproduction processor is provided on the input side of the decryption device in place of the recording processor 24. The reproduction signal corrected by the reproduction processor is error-corrected. Is input to the decryption device, where the decryption is performed using the key information from the key generator 22 and the data is output.

At this time, since the identification signal input to the key generator 22 is the device individual information (serial number) of the deck 11 extracted by the device individual information extracting means 12,
Only when played back on the same deck as at the time of recording, the same serial number is obtained and the same key information is generated, so that the encryption can be decrypted. On the other hand, at the time of compatible reproduction in which reproduction is performed on a deck different from that at the time of recording, a serial number different from that at the time of recording is extracted from the deck, so that the generated key information is different from that at the time of recording, so that the encryption cannot be decrypted.

Note that the reproduction signal decoding means 34
And a descrambler may be provided in place of the scrambler 19 in place of the recording processing unit 18. The lower 15 bits of the device individual information (serial number) of the deck 11 extracted by 12 are output to the descrambler as key information, and the initial value is exclusively ORed with the initial value at the timing of loading the initial value. However, D-VHS tape has a track pitch of 29μ.
When the digital signal recorded by m is reproduced, the reproduction processing unit is forcibly reset so that the serial number becomes "0".

In FIG. 4, when the recording mode discriminating means 31 recognizes that the tape feed is at a track pitch of 29 μm and the medium discriminating means 13 discriminates that the tape is a VHS tape, the reproduction signal is output. The decoding means 34 is provided by the device individual information extracting means 12 by the deck 11.
Receiving the device individual information (serial number) extracted from the device as input, generating key information from the device individual information by the above-described method, and reproducing the reproduced signal unformatted by the formatting means 33 while releasing the key. (However, as described above, this is possible only when the data is reproduced by the same digital signal recording / reproducing apparatus used for recording.)

As a result, in the case of a D-VHS tape on which a digital signal is recorded at a track pitch of 29 μm, it is not necessary to release the key, so that the recording signal of the D-VHS tape is self-recorded by the same device. It can be reproduced regardless of whether it is a compatible reproduction recorded on a different device or a D-VHS tape recording a digital signal at a track pitch of 19 μm or a VHS tape recording a digital signal at a track pitch of 29 μm. In such a case, the self-recording can be reproduced, whereas the compatible reproduction has different key information, so that data cannot be reproduced accurately in principle. However, the key information is limited by bits and has a certain probability (in the example of FIG. 3, a probability of 1/32708).
Can be played in some cases.

That is, when a D-VHS tape is used for self-recording / playback, the normal mode (track pitch 29 μm)
The digital signal can be recorded / reproduced in both the normal mode and the long time mode (track pitch 19 μm).
m) can be used to record and reproduce digital signals. Also,
When a D-VHS tape is used, self-playback and compatible playback are both possible in the normal mode. However, the D-VHS tape recorded in the long-time mode and the VHS tape recorded in the standard mode are not supported. , Compatible playback is not possible.

As a result, the D-VHS tape recorded in the long-time mode from the beginning and the standard-mode D-VHS tape can be used without displaying a message such as "Please use the long-time mode in self-recording / playback". It is known that compatible playback is not possible with VHS tapes. If you try to use compatible playback, you can display "Not self-recording" on the monitor screen or forcibly stop the tape. It is possible and easy to understand.

In this manner, recording on various media and various tape running speeds can prevent the overflow of the format of the system which is originally possible, and can prevent self-recording / reproducing without causing a problem of compatible reproduction. , It is possible to construct a system that fully exploits the characteristics of the medium.

It should be noted that the present invention is not limited to the above-described embodiment. For example, the present invention can be applied to three or more types of modes, and the present invention can be applied to three or more types of magnetic tapes. It is also possible to apply.

[0039]

As described above, according to the present invention,
Depending on the combination of the selected recording mode and the type of recording medium, only self-recording / playback is possible or both self-recording / playback and compatible playback are possible. It is possible to build a system that can fully utilize the characteristics of a recording medium in self-recording / reproduction without preventing the overflow of the format of the system in which recording in the recording mode is originally possible and without causing a problem of compatible reproduction. .

Further, according to the present invention, for a user who wants to enjoy time-shift recording of a television or long-time recording by himself, compatible reproduction is not required, and the characteristics of the recording medium are lower than the standard and inexpensive. It is possible to use a recording medium (for example, VHS tape) capable of only self-recording and reproduction, and to realize an economical digital signal recording / reproducing apparatus.

[Brief description of the drawings]

FIG. 1 is a block diagram of a recording system according to an embodiment of the present invention.

FIG. 2 is a block diagram illustrating an example of a key information generation unit.

FIG. 3 is a block diagram of an example of a recording signal generation unit in FIG.

FIG. 4 is a block diagram of a reproducing system according to an embodiment of the present invention.

[Explanation of symbols]

 Reference Signs List 11 deck 12 device individual information extracting means 13 medium discriminating means 14, 33 formatting means 15 recording mode setting means 16 recording signal generating means 17 recording amplifier 18 recording processing unit 19 scrambler 31 recording mode discriminating means 34 reproduction signal decoding means

Claims (5)

[Claims] 1. A medium discriminating means for discriminating a type of a recording medium to be recorded and reproduced; a first key information generating means for generating first key information based on identification information unique to a device to be recorded; An encryption unit for encrypting the digital signal using the first key information; and a combination of a recording mode selected from a plurality of recording modes and a type of the recording medium determined by the medium determination unit is determined. In the first combination, the digital signal encrypted by the encrypting means is recorded on the recording medium, and in the second combination, the unencrypted digital signal is stored in the recording medium. Recording means for recording on a recording medium; second key information generating means for generating second key information based on second identification information unique to a device for reproducing a digital signal recorded on the recording medium; Medium A recording mode discriminating means for reproducing the recorded digital signal and discriminating the recording mode; and a combination of the recording mode discriminated by the recording mode discriminating means and the type of the recording medium discriminated by the medium discriminating means is the first. When the combination is a combination of the above, the encryption of the digital signal reproduced from the recording medium is decrypted and decoded using the second key information, and the recording mode determined by the recording mode determining means and the medium determining means are used. A digital signal recording / reproducing apparatus, comprising: decoding means for decoding, when the determined combination with the type of recording medium is the second combination, irrespective of the second key information. 2. The recording mode of the first combination,
2. The digital signal recording / reproducing apparatus according to claim 1, wherein the digital signal is recorded in a long time recording mode in which a track is formed at a track pitch narrower than a standard mode. 3. The digital signal recording / reproducing apparatus according to claim 1, wherein the type of the recording medium in the first combination is a type of recording medium having characteristics lower than those of a predetermined type of recording medium. . 4. The first combination is that, when the type of the recording medium is the predetermined type, the recording mode forms a track at a track pitch narrower than that of a standard mode, and 4. The digital signal recording / reproducing apparatus according to claim 3, wherein the digital signal recording / reproducing apparatus is in a long time recording mode for recording a digital signal. 5. The digital signal recording / reproducing apparatus according to claim 1, wherein in the second combination, the type of the recording medium is a predetermined type of recording medium, and the recording mode is a standard mode.