JPH07230667A - Information recording and reproducing device - Google Patents

Abstract

PURPOSE:To restrict the reproduction of recorded information and to protect the copyright by determining the term of validity for reproducing information to be transmitted and recorded and interrupting the reproducing signal of the transmitted information at the expiration of the term of validity. CONSTITUTION:A recording means including a recording amplifier 18 and magnetic heads 3a, 3b, etc., and a reproducing means including a reproducing amplifier 23 and magnetic heads 3a, 3b record and reproduce a main information signal and the signal of the term of validity for production, respectively. A detecting circuit 27 for the term of validity information and a detecting circuit 28 for date-time information extract the pieces of index information at the time of recording and reproducing, respectively and supply them to a comparator circuit 29. The comparator circuit 29 receives them, compares the information of the term of validity for reproduction with the absolute date information at the time of reproduction and supplies a control signal to a signal interrupting circuit 30. The signal interrupting circuit 30 cuts off a reproducing digital signal when the date/time at the time of reproduction is out of the term of validity for reproduction and supplies the reproducing digital signal to a memory circuit 31 when it falls within the range of the term of validity for reproduction.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an information recording / reproducing apparatus for recording / reproducing a digital information signal supplied via a transmission line, and more particularly to a mechanism for protecting the copyright of digital information transmitted / recorded. The present invention relates to an information recording / reproducing device.

[0002]

2. Description of the Related Art AV systems and communication systems have been developed with the progress of coding (digitization) techniques of video and audio information and their compression techniques, and progress of digital signal processing LSIs represented by microprocessors and digital signal processors. And the fusion of computer systems is becoming possible, and a system called multimedia has attracted attention. In one area of this multimedia,
For example, there is an interactive cable television (CATV). This CATV is currently analog transmission, but it is expected that it will shift to digital transmission in the future. In that case,
The information (television signal) supplied is the current analog NT.
Not only uniform information such as SC signal but also video and audio quality (information compression rate) and data transmission rate can be set to some extent according to viewer's request. Moreover, it is considered that the transmission information itself can widely transmit not only television signals but also other digital information. Note that technical information on CATV can be found in, for example, Journal of Television Society, Vol. 47, No. 8 1993 "Small Feature: Cable TV Technology Trends" P1048-P
1087.

In addition, MPEG (Moving Picture I) using motion compensation and DCT (Discrete Cosine Transform) as a compression method by digital signal processing of current video information.
The mageCoding Expert Group) method has been developed, and significant compression is becoming possible. Generally, compression ratio and quality are contradictory in video information, etc., but these are properly used depending on the application and purpose. For example, in the case of current television (NTSC) signals, the quality after compression is set to a quality equivalent to the VTR recording level. In that case, there is a report that transmission including a voice signal is possible at about 1.5 Mbps. Hereinafter, a video signal (including audio) of about 1.5 Mbps transmission is referred to as a compressed video signal.
Note that the compression technique of video information is described in, for example, the Journal of Television Society, Vol. 47, No. 6 1993 "Minor Special Issue: Digital Recording Technology and Its Applications, 1-2: Trend of Digital Video Technology and Digital Recording Technology" P801-
P806 and the same magazine, Vol. 47, No. 10 1993
"Trends in Digital Video Transmission Technology" P1269-P1
276, etc. When transmitting the above low transmission rate information using a transmission line such as CATV having a band of about 6 MHz per channel,
A transmission rate of about 20 to 25 Mbps is possible, and a compressed television signal as described above can transmit information of about 12 channels even if redundant data is included. In the case of high quality video signals, 10 Mbps is also applied due to the compression technology.
Transmission is possible with a degree, and in this case, two-channel transmission is possible.

On the other hand, even in a VTR for recording / reproducing digital information on / from the transmission line of the CATV or the like, for example, Nikkei Electronics, 1993.7.19 (no. 5).
86) As described in P66, the transmission rate in recording / reproducing is 25 Mb with a single head configuration even at the consumer level due to the increase in the relative speed between the magnetic head and the tape.
ps, 50M with multi-head (2 channels) configuration
A digital VTR having a recording / reproducing transmission rate of about bps is technically feasible. Therefore, this 2
If a digital VTR having a recording / reproducing transmission rate of about 5 Mbps is used, 12 channels of the above compressed video signal including redundant data and the like can be recorded in the case of a high quality compressed video signal by 2 channels. The above-mentioned quality and data transmission rate are specific examples.

When video information or audio information is handled as a digital signal, the digital information should be transmitted or recorded without distinction from video, audio, programs and data handled by a computer, and any other digital information. You can In other words, with regard to the transmission and recording of digital information, it will be possible to process regardless of the type of information that is the subject, and in the future CA
By using a transmission line such as a TV, it is possible to supply not only a video signal but also all kinds of digital information such as a program handled by a computer and its data.

On the other hand, at present, the system for supplying information such as video software and computer software (including game software) is package (cassette tape, disk or ROM).
Media is the center, and such software information is sold or rented. On the other hand, with the development of the digital information network and the spread of the VTR capable of recording and reproducing the digital information as described above, a lot of software information is supplied through the digital information transmission network instead of the package medium. Seems to be possible.

[0007]

However, the transmission of information and the digital V by the digital information network as described above.
In the recording / reproducing by TR, the quality deterioration in the transmission and recording / reproducing process is small, and the copyright of the supplied software information cannot be protected as it is. This is the sale of software information when the user (viewer) records the transmitted information such as video software and makes it semi-permanently owned by the user. Supply at low prices becomes difficult. Conversely, in order to enable the distribution of software information at a low price like the current rental video, it is necessary to use a different copyright protection means than before.

Therefore, while the conventional copyright protection was mainly for the prevention of dubbing (anti-copy), the present invention does not use the copyright information at the stage of acquiring and recording the software information. It was considered to be the use of copyright information. Therefore, an object of the present invention is to provide an information recording / reproducing apparatus for recording / reproducing information supplied via a transmission path, which is capable of restricting reproduction of information recorded for the purpose of copyright protection. Is provided.

[0009]

In order to achieve the above-mentioned object, the present invention provides a main information signal supplied via a transmission line and a main information signal accompanying the main information signal in an information recording / reproducing apparatus. A recording means for recording an expiration date signal indicating the reproduction expiration date of, a reproducing means for reproducing the main information signal and the expiration signal, and a time axis for generating or obtaining a time axis information signal such as date and time. Information generating means, comparing means for comparing the expiration date signal reproduced by the reproducing means with the time axis information signal detected by the time axis information generating means, and the reproducing operation according to the comparison signal of the comparing means. A signal cut-off means for cutting off the output of the main information signal, and when the value of the time axis information signal exceeds the value of the expiration signal, the signal cut-off means sets It is configured to block the output of the broadcast signal.

In addition, when the interruption device interrupts the main information signal, it is provided with display information generating means for displaying that the reproduction expiration date of the main information signal has expired.

[0011]

As a function of each of the above means, the recording means records the main information signal supplied through the transmission line and the expiration date signal indicating the reproduction expiration date of the main information signal accompanying the main information signal. The reproducing means reproduces the recorded main information signal and the recorded expiration date signal. The time-axis information generating means generates a time-axis information signal such as a date and time by a timer or the like that counts a stable clock, or by detecting the time-axis information supplied through the transmission path. To do. The comparing means compares the expiration date signal reproduced by the reproducing means with the time axis information signal generated or detected by the time axis information generating means, and reproduces the time axis information (such as time including date). ) Is over the expiration date and a comparison signal is supplied to the interruption device. According to the comparison signal of the comparison means, the signal cutoff means cuts off the output of the reproduced main information signal when the time axis information exceeds the expiration date. With the above configuration and operation, the reproduction expiration date of the main information signal supplied through the transmission path can be set, and if the expiration date is exceeded, the reproduction of the main information signal cannot be performed. Is protected.

Further, the display information generating means makes it possible to display that the reproduction cannot be performed because the expiration date of the main information signal has expired. You can do well.

[0013]

Embodiments of the present invention will now be described in detail with reference to the drawings. First, prior to a detailed description of the information recording / reproducing apparatus of the present invention, a usage environment of the apparatus will be briefly described with reference to FIG. FIG. 2 shows an environment in which the information recording / reproducing apparatus is used. In FIG. 2, a broken line part 36 shows a transmitting station system for supplying a digital information signal, 37 is a transmission line of the digital information signal, and a broken line part 38 is a viewer (user) device having the information recording / reproducing device. The system is shown. The transmitting station 36 uses, for example, a digital VTR 39, a disk device 40, or a semiconductor recording / reproducing device 41 using a large-capacity memory, etc., to compress the information of the digital information signal (main digital information signal) by the MPEG method and the time base. After compression, P at the specified transmission rate
It is supplied to the CM encoder 42. PCM encoder 42
In order to prevent an adverse effect due to the occurrence of a code error (error) in the transmission process of the digital information signal, an error detection / correction code and a synchronization signal are generated / added, and the date and time supplied from the calendar timer circuit 43 and Time axis information such as time (hereinafter referred to as date / time information) and expiration date information that defines the expiration date of the transmission information supplied from the expiration information generating circuit 45 are added to the transmission information as index signals. The expiration date information is not uniquely determined and is requested by the information receiver (user). For example, as shown in FIG. It detects and decodes it to determine the expiration date.
Generally, the longer the expiration date, the higher the information supply price is set. The user's request is not limited to the use of the telephone line, but the transmission line 37 is a bidirectional transmission line, for example, a bidirectional CAT.
In the case of a transmission path such as V, the bidirectional transmission path may be used as a matter of course. The digital information signal to which the redundant data has been added by the PCM encoder 42 is supplied to the modulation circuit 46. The modulation circuit 46 converts the digital information signal into an efficient signal form suitable for the characteristics of the transmission line 37 at the next stage, for example, multi-level QAM or the like, and outputs it. The digital information signal supplied through the transmission line 37 is the information recording / reproducing apparatus 4
At 7 the original time axis is expanded, and when the transmission information is a video and audio signal, the information is expanded (decompressed), converted into an analog signal and output to the television monitor-device 48. If the transmission information signal is a program or data used in a computer device, etc., it is reproduced at a transmission rate suitable for the external device by an external command (control signal), and digital information of the computer or the like is reproduced. It is supplied to the device 49. Whether the transmitted digital information signal is a video / audio signal or a program and data signal can be easily determined by detecting the index signal added by the PCM encoder 42. Is.

A detailed description of the information recording / reproducing apparatus of the present invention will be given with reference to FIG. FIG. 1 is a block diagram showing the configuration of an information recording / reproducing apparatus to which the present invention is applied. In FIG.
1 is a magnetic tape, 2 is a drum (including a drum motor), 3a and 3b are magnetic heads, 4 is a capstan, 5
Is a capstan motor, 6 is a CTL head, 7 to 11 are signal input or output terminals, 12 is a channel selector (tuner), 13 is a demodulation circuit, 14 is a PCM decoder, and 15 and 26 are index signals. A detection circuit, 16 is a digital signal processor (hereinafter referred to as DSP), 17 is a modulation circuit, 18 is a recording amplifier, 19 is a system controller, 20 is a drum servo circuit, 21 is a CTL signal generation / detection circuit, 22 is a capstan servo circuit, 23 is a reproduction amplifier, 24 is a demodulation circuit, and 25 is a DS.
P, 27 is an expiration date information detection circuit, 28 is a date / time information detection circuit, 29 is a comparison circuit, 30 is a signal cutoff circuit, 31
Is a memory circuit, 32 is an MPEG decoder (information decompression circuit), 33 is a DA converter, 34 is a character generator, and 35 is an addition circuit. First, the operation at the time of recording will be described along the flow of signals.

In FIG. 1, the input information signal supplied through the input terminal 7 is supplied to the channel selector 12. The channel selector 12 is a system controller.
The information signal of a desired channel is selected according to the channel designation signal CH supplied from the receiver 19 and supplied to the demodulation circuit 13. The channel designation signal CH is set by the user command signal supplied through the input / output terminal 8. The demodulation circuit 13 demodulates the input information signal, which has been modulated into a signal form suitable for the transmission line 37, converts it into an original digital signal, and supplies it to the PCM decoder 14. PCM
The decoder 14 performs error detection and correction of the input digital information signal, supplies the digital information signal to the DSP 16 at the next stage, and supplies the multiplexed index signal TID to the index signal detection circuit 15. . Further, the sync signal SYC for detecting the data block structure of the input digital signal is separated and separated from the drum server.
Supply to the circuit 20. The index signal detection circuit 15 supplied with the index signal TDI has transmitted the data necessary for reproducing the information of the time base compression rate and the information indicating the kind of the recording information signal from the index signal. The expiration date information data indicating the reproduction expiration date of the information signal and the transmitted date time information data are supplied to the DSP 16 as the recording signal RID. Further, the input index signal information is supplied to the system controller 19 and from there is supplied to a display system (not shown) via the input / output terminal 8 to display the index signal information on the user. The DSP 16 converts the digital information signal supplied from the PCM decoder 15 and the index signal necessary for reproduction supplied from the index signal detection circuit 15 into a signal form suitable for magnetic recording and reproduction. That is, in order to cope with a code error in magnetic recording / reproduction,
Block data, add address data, interface
Error detection and correction codes such as the leave and lead solomon codes are added.

FIG. 3 shows an example of the block structure of the recording information signal. The digital information and index signals input to the DSP 16 are arranged as shown in the lower part of FIG. 3 in units of information recorded on one track (a track formed by the magnetic head in one scan), for example. After the outer check code is added in the vertical direction, the inner check code is added in the horizontal direction. It should be noted that the check codes are generated for the data A and the address information and the data B as shown in the upper part of FIG. As described above, the recording information signal to which the error detection and correction code is added is supplied with the block synchronization signal (hereinafter referred to as SYNC) indicating the beginning of the block before the address information and supplied to the modulation circuit 17. Further, FIG. 4 shows an example of the data structure of the recording index signal. In FIG. 4, the index signal is composed of byte units, and ID0 determines the mode of the index signal. ID1 to ID7 are date and time information data at the time of recording, ID8 determines the expiration date mode, and ID9 to IDF are expiration date data. The ID1 to IDF are used for the data such as the time axis compression rate information, the type information of the recording information signal or the type information of the compression method such as the MPEG method, the user's data, etc., according to the data of the ID0. This index signal can record various index information by recording in different index signal modes for each track, for example.

The recording digital signal to which the redundant data has been added is supplied to a modulation circuit 17, subjected to modulation processing such as 8-10 conversion suitable for magnetic recording, and supplied to a recording amplifier 18 as a serial signal. The recording amplifier 18 is
The recorded digital signal is amplified to a level suitable for magnetic recording and recorded on the magnetic tape through the magnetic heads 3a and 3b with an optimum recording current.

Now, the servo of the drum 2 and the capstan 4 at the time of recording will be described. The drum 2 and the capstan 4 are controlled by the command signal D for the drum and the capstan supplied from the system controller 19.
It is performed by the drum servo circuit 20 and the capstan servo circuit 22 according to C and CC. FIG. 5 is a block diagram showing the configuration of the drum servo circuit 20 and the capstan servo circuit 22.

In FIG. 5, the broken line portion 20 is the drum servo circuit, and the broken line portion 22 is the capstan servo circuit. And 51 to 54 and 66 to 68 are input terminals, 5
5, 56, 69 are output terminals, 57, 70 are speed detection circuits, 58, 71 are speed target setting circuits, 59, 62,
72 is a subtraction circuit, 60 is a phase detection circuit, 61 is a phase target setting circuit, 63 and 75 are addition & characteristic compensation circuits, 56 and 7
6 is a DA converter, and 65 and 77 are motor drivers.
An amplifier (hereinafter referred to as MDA) 63, an integrating circuit, and 74 are switches.

First, the drum servo will be described. In FIG. 5, the DFG (Dr supplied through the input terminal 52
The am frequency generator signal is supplied to the speed detection circuit 57. Although not shown, the DFG signal generation mechanism is a frequency signal generated in proportion to the rotation frequency of the drum 2. The speed detection circuit 57 detects the rotation speed of the drum 2 by measuring the period of the DFG signal, and supplies the speed detection information to the subtraction circuit 59. The drum command signal DC supplied from the system controller 19 via the input terminal 51 is supplied to the speed target setting circuit 58 and the phase target setting circuit 61. The speed target setting circuit 58 generates a rotation speed target of the drum 2 in accordance with the drum command signal DC and supplies the speed target information to the subtraction circuit 59. Subtraction circuit 5
Reference numeral 9 subtracts the speed detection information from the speed target information and supplies the speed error information, which is the difference, to the addition & characteristic compensation circuit 63. On the other hand, a DPG (Dram Phase Generator) signal supplied via the input terminal 53 is supplied to the phase detection circuit 60. Although not shown, the DPG signal is synchronized with the rotation of the drum 2 and the magnetic head 3a or 3b.
Is a phase signal having a predetermined phase relationship with the rotation phase of. The phase detection circuit 60 detects the rotational phase of the drum 2 by detecting the phase of the DPG signal, and supplies the phase detection information to the subtraction circuit 62. The phase target setting circuit 61 generates phase target information from the synchronizing signal of the input information signal supplied from the PCM decoder 14 via the input terminal 54 during recording, and supplies the phase target information to the subtraction circuit 62. . Further, the phase target setting circuit 61 supplies the reference signal of the rotation frequency of the drum 2 to the CTL generation / detection circuit 21 via the output terminal 55 in synchronization with the rotation phase of the drum 2. The subtraction circuit 62 subtracts the phase detection information and the phase target information, and supplies the phase error information which is the difference to the addition & characteristic compensation circuit 63. Addition & characteristic compensation circuit 63
Adds the velocity error information and the phase error information, performs characteristic compensation filter processing such as phase delay compensation so as to obtain a desired servo characteristic, and supplies it to the DA converter 64. The DA converter 64 is an addition & characteristic compensation circuit 6
The drum control signal supplied from 3 is converted into an analog signal and supplied to the MDA 65. The MDA 65 amplifies the power of the drum control signal and supplies it as a drum drive signal to the drum 2 via the output terminal 56 to rotate the drum 2 at a predetermined speed and a predetermined phase. The above-mentioned phase target information is generated by using the synchronization signal of the input information signal. This is because the drum 2 is rotationally controlled in accordance with the transmission rate of the input information signal, so that the input information signal is overwritten. It is designed to be able to record without any shortage.

Next, the capstan servo will be described. CF supplied via the input terminal 67 in FIG.
The G (Capsutan Frequency Generator) signal is supplied to the speed detection circuit 70. Although not shown, the generation mechanism of the CFG signal is a frequency signal generated in proportion to the rotation frequency of the capstan 4, like the DFG signal. The speed detection circuit 70 detects the rotation speed of the capstan 4 by measuring the cycle of the CFG signal, and supplies the speed detection information to the subtraction circuit 72. Capstan command signal C supplied from the system controller 19 via the input terminal 66.
C is supplied to the speed target setting circuit 71. The speed target setting circuit 71 generates a rotation speed target of the capstan 4 according to the capstan command signal CC, and supplies the speed target information to the subtraction circuit 72. The subtraction circuit 72 subtracts the speed detection information and the speed target information, and supplies the speed error information which is the difference to the addition & characteristic compensation circuit 75 and the integration circuit 73. The integrating circuit 73 generates speed error integration information by sequentially accumulating the speed error information supplied from the subtraction circuit 72, and supplies this speed error integration information to the switch 74. Switch 74 is set to A during recording
The speed error integral information output from the integrating circuit 73, which is closed on the input terminal side, is supplied to the adding & characteristic compensating circuit 75.
The addition & characteristic compensation circuit 75 adds the velocity error information and the velocity error integration information and performs characteristic compensation filter processing such as phase delay compensation so as to obtain a desired servo characteristic, and a DA converter. Supply to 76. DA converter 7
6 converts the capstan control signal supplied from the addition & characteristic compensation circuit 75 into an analog signal and supplies the analog signal to the MDA 77. The MDA 77 amplifies the power of the capstan control signal and supplies it as a capstan drive signal to the capstan motor 5 through the output terminal 69 to rotate the capstan 2 at a predetermined speed and the magnetic tape 1 to a predetermined speed. To run. The integrating circuit 73 is provided with an integral control system in addition to the speed system (proportional control system) so that the steady speed deviation becomes zero.

In the above recording operation, the rotation reference signal of the drum 2 supplied from the phase target setting circuit 61 of the drum system is supplied to the CTL generation / detection circuit 21 shown in FIG. It becomes a control signal (hereinafter referred to as a CTL signal) having a frequency obtained by multiplying the signal. The CTL signal is converted into a signal level suitable for magnetic recording and then recorded on a linear track on the magnetic tape via the CTL head 6. In this embodiment, the frequency multiplication rate of the CTL signal is set equal to the time-axis compression rate of the recording information signal.

Next, the operation during reproduction, which is important in the present invention, will be described. In FIG. 1, the reproduction signal reproduced from the magnetic tape 1 by the magnetic head 3a or 3b is sufficiently amplified by the reproduction amplifier 23 and then supplied to the demodulation circuit 24. The demodulation circuit 24 equalizes the waveform of the supplied reproduction information signal, extracts a clock component, strobes the reproduction data using this clock, and converts it into a logic signal. Then, the demodulation process of the reverse conversion at the time of recording is performed and the demodulated reproduced digital signal is supplied to the DSP 25. The DSP 25 performs error detection / correction on the reproduced digital signal, deinterleaves based on the address information to restore the original data sequence, and returns the index signal PI.
D is supplied to the index signal detection circuit 26, and reproduced digital information is supplied to the signal cutoff circuit 30.

The index signal detection circuit 26, the expiration date information detection circuit 27, the date / time information detection circuit 28, the comparison circuit 29, and the signal cutoff circuit 30 serve to protect the copyright of the supply information, which is the object of the present invention. Play an important role in. The index signal detection circuit 26 is the I signal shown in FIG.
Mode decoding of D0 is performed, and various index signals are supplied to the expiration date information detection circuit 27 and the system controller 19. The expiration date information detection circuit 27 extracts an index signal (ID9 to IDF in FIG. 4) relating to the reproduction expiration date information of the recorded digital information signal from the input reproduction index signal, and compares this index signal PDT. Supply to the circuit 29. Further, the system controller 19 to which the above-mentioned index signal is input determines the reproduction mode based on the reproduction index signal, and information that should be notified to the user, for example, information regarding the recorded date and time and the type of recorded information. Is supplied to the display system (not shown) via the input / output terminal 8. The comparison circuit 29 to which the index signal relating to the reproduction expiration date information is input is a circuit for determining whether or not the date and time at the reproduction time point has exceeded the expiration date of the reproduction signal, and therefore the absolute date at the reproduction time point is set. Time information is required. The absolute date / time information at the time of reproduction is supplied from the date / time information detection circuit 28. The date / time information detection circuit 28 compares the date / time information supplied from the transmission line 37 through the input terminal 7, the channel selector 12, the demodulation circuit 13, the PCM decoder 14 and the index signal detection circuit 15 as in the recording. Supply to the circuit 29. The comparison circuit 29 compares the reproduction expiration date information with the absolute date / time information at the reproduction time point, and supplies a control signal to the signal cutoff circuit 30 and the character generator 34.

In the above case, the date / time information used at the time of reproduction is transmitted as redundant data of the main digital information signal to be transmitted, but this absolute date / time information is transmitted through the transmission line 37. Another channel may be used for transmission, reception and detection independently of the main digital information signal.

The signal cutoff circuit 30 to which the reproduced digital signal supplied from the DSP 25 is inputted, according to the control signal supplied from the comparator circuit 29, outputs the inputted reproduced digital signal to the memory circuit 39 of the next stage. Switch between supplying and shutting off. As is clear from the above point, this switching cuts off the playback digital signal when the date and time at the playback time has passed the playback expiration date, and the date and time at the playback time falls within the playback expiration date range. In some cases, the reproduced digital signal is supplied to the memory circuit 31. The memory circuit 31 converts the reproduced digital signal into a predetermined transmission rate and supplies it to the MPEG decoder 32 and the output terminal 10. The MPEG decoder 32 decompresses (expands) compression by decoding when the reproduced signal is a compressed signal of the MPEG system according to the identification signal of the reproduced digital signal supplied from the system controller 19 and a setting signal such as the decoding system. DA converter 3 for digital video signals and digital audio signals
Supply to 3. The DA converter 33 converts the supplied digital video and audio signals into analog signals, and supplies the video signals to the adder circuit 35 and the audio signals to the output terminal 11. The adding circuit 35 combines and adds the reproduced video signal and the character signal supplied from the character generator 34, and outputs the result through the output terminal 10. When the reproduction signal is cut off by the signal cut-off circuit 30 according to the control signal supplied from the comparison circuit 29, the character generator 34 monitors the expiration indication to notify the user that the expiration date has expired. A character signal is generated for display on 48.

When the reproduced digital signal is a data signal used in computer equipment or the like, it is output through the output terminal 10 after being converted to a predetermined transmission rate.

Next, regarding servo control during reproduction,
A brief description will be given with reference to FIG. First, the drum servo will be described. In FIG. 5, the speed control of the drum 2 is performed by generating speed error information by the speed detection circuit 57, the speed target setting circuit 58, and the subtraction circuit 59 by the same processing as that at the time of recording described above. In the phase control, the synchronizing signal of the input digital information signal is not always supplied at the time of reproduction, so that the phase target setting circuit 61 shown in FIG. A phase reference signal in the rotation of the drum 2 is generated by using such a clock, a phase target signal is generated by this phase reference signal, and the phase target signal is supplied to the subtraction circuit 62. Then, the subtraction circuit 62 subtracts the phase detection information from the phase target information, and supplies the phase error information which is the difference to the addition & characteristic compensation circuit 63. Processing after the addition & characteristic compensation circuit 63 is the same as that at the time of recording.

In the tape running control during reproduction, that is, the capstan control, it is necessary to decelerate the tape running speed in accordance with the time axis compression ratio of the recorded digital information signal.

In FIG. 5, the speed detection circuit 70 detects the rotation speed of the capstan 4 by measuring the period of the CFG signal, and supplies the speed detection information to the subtraction circuit 72. The speed target setting circuit 71 is the system controller 1
A rotation speed target of the capstan 4 is generated according to the capstan command signal CC supplied from the input terminal 66 from the input terminal 9, and the speed target information is supplied to the subtraction circuit 72. The system controller 19 detects the time base compression rate information of the reproduction digital signal from the reproduction index signal, determines the speed target of the capstan 4 from this information, and supplies it as the capstan command signal CC to the speed target setting circuit 71. To do. Therefore, when the time base compression rate of the reproduced digital signal is 1 / N, the tape speed target during reproduction is set to 1 / N of the tape speed during recording.

In order to correctly control the tape speed during reproduction with respect to the tape speed during recording, it is necessary to configure a speed integral control system, which is performed using the reproduction CTL signal. The integral control of the speed by the reproduction CTL signal is generated in the CTL generation / detection circuit 21 in FIG. 1 using the reproduction CTL signal detected from the CTL head 6 and the stable clock in the phase target setting circuit 61 shown in FIG. The rotation reference signal of the drum 2 is compared with the phase reference signal to generate a phase error signal. The phase error signal generated by the reproduced CTL signal is the input terminal 68 shown in FIG.
Is supplied to the switch 74 via. The switch 74 is closed to the B terminal side during reproduction, and supplies the phase error signal generated from the reproduction CTL signal to the addition & characteristic compensation circuit 75. By the above operation, the tape running speed is controlled so that the reproduction CTL signal frequency becomes 1 / N of the recording CTL signal frequency.

As described above, according to this embodiment, when the information signal supplied via the transmission line and having the limited reproduction period is recorded and reproduced, the reproduction expiration date of the supplied digital information is the main. It is possible to record the information together with the information, detect the expiration date information at the time of reproduction, and cut off the output of the reproduction digital information when the date and time at the reproduction time have passed the reproduction expiration date. As a result, it is possible to prevent the reproduction of the information supplied over the limited range of the period and to protect the copyright of the transmission information (recording / reproduction information). In addition, since the date and time information at the time of reproduction, which is the criterion for determining the expiration date, is supplied from the above transmission line, the user cannot change the date and time at the time of reproduction, so it is correct. You can judge the expiration date.

In the above embodiment, when the user tries to reproduce pirated information, that is, information whose expiration date has expired, the information recording / reproducing device 47 and the transmission line 37 are reproduced at the time of reproduction.
It is necessary to ensure that the reproduction signal, which is the protection of the copyrighted work, can be cut off even when the update of the absolute date and time at the time of reproduction is stopped by cutting off the. In order to prevent this piracy, for example, the cutoff detection circuit for the absolute date and time information transmitted as shown by the broken line portion 78 in FIG. 6 is provided with the date and time information detection circuit 28 and the comparison circuit shown in FIG. It is possible to take countermeasures by providing it between 29. In FIG. 6, blocks denoted by reference numerals 27, 28 and 29 are blocks having the same reference numerals in FIG. 1, 81 is a signal combining circuit, and 82 is a control signal output terminal. The cutoff detection circuit 78 for date / time information is composed of a latch circuit 79 and a comparison circuit 80. In FIG. 6, the latch circuit 79
Latches the date and time information supplied from the date and time information detection circuit 28 at a predetermined timing interval, and supplies the latched date and time information to the comparison circuit 80. Comparison circuit 80
Compares the latched date / time information with the date / time information directly supplied from the date / time information detection circuit 28, and judges that the date / time information is not supplied if the date / time is not updated, The control signal is supplied to the signal synthesis circuit 81. The signal synthesizing circuit 81 generates a new control signal to be supplied to the signal cutoff circuit 30 and the character generator 34 from the control signal supplied from the comparison circuit 29 and the control signal supplied from the comparison circuit 80. . The control signal supplied from the signal synthesis circuit 81 is
If the date and time information is not supplied, the signal cutoff circuit 3
0 controls the reproduction digital signal to be cut off, and also controls the character generator 34 to generate a character signal which prompts confirmation of the connection with the transmission line 37 because the date / time information is not supplied. On the other hand, when the date and time information is supplied, the output control signal of the comparison circuit 29 described above is supplied to the signal cutoff circuit 30 and the character generator 34 as it is.

By providing the cutoff detection circuit for date / time information as described above, the information recording / reproducing apparatus 47 at the time of reproduction.
By blocking the transmission line 37 and the absolute date and time at the time of reproduction, the copyright is surely protected against piracy of a user who tries to reproduce the expired information. It is possible to cut off the reproduction signal.

Next, a second embodiment will be described.
The major difference between the second embodiment and the previous embodiment is the method of setting the expiration date of the reproduced digital information. In the first embodiment, the reproduction expiration date is set by the absolute date and time regardless of the date and time when the information is transmitted and recorded, whereas in the present embodiment, the information is transmitted and recorded. It is intended to limit the reproduction period by the relative reproduction effective period with respect to the specified date and time. Hereinafter, a detailed description will be given with reference to FIG. 7. FIG. 7 is a block diagram showing the structure of an information recording / reproducing apparatus to which the present invention is applied. In FIG. 7, blocks designated by the same reference numerals as the blocks shown in FIG.
It has the same or similar function as the block of FIG. Incidentally, reference numeral 83 in FIG. 7 merely represents the drum servo circuit 20, the CTL generation / detection circuit 21, and the capstan servo circuit 22 in FIG. 1 as a servo circuit, and the operation thereof is the same as the above three blocks. It works. The apparatus of FIG. 7 is different from the apparatus of FIG. 1 in that the expiration date of reproduction information is determined.
While the expiration date information detecting circuit 27 in FIG. 1 is deleted, an effective period information detecting circuit 84, a recording date / time information detecting circuit 85 and an arithmetic circuit 86 are newly provided. Hereinafter, the operation of the expiration date determination portion of the reproduction information will be mainly described.

First, in this embodiment, when setting the reproduction expiration date of the transmitted information, the date and time information at the time of transmission and recording and the relative reproduction effective period with respect to the date and time at the time of transmission and recording are set. I am trying to set it. This is because the expiration date information generation circuit 45 shown in FIG. 2 on the information supply side sets an absolute expiration date when the expiration date information is generated, while the date generated by the calendar timer circuit 43. By referring to the time information, a relative effective period is generated and is supplied to the transmission path together with the main digital information signal. Next, in the recording system of the information recording / reproducing apparatus shown in FIG. 7, relative expiration date information, that is, the effective period in which the information of ID8 to IDF in the index signal shown in FIG. 4 is supplied through the transmission path. Replace with information. Then, in the reproducing system, at the time of reproduction, FIG.
The effective period information of the reproduction information is detected by the effective period information detection circuit 84 from the reproduction index signal PID supplied from the index signal detection circuit 26 shown in FIG. To detect. The valid period information and the recorded date and time information are
It is supplied to the arithmetic circuit 86 and the reproduction effective period is added to the recorded date and time to make absolute effective period information PDT. This absolute expiration date information PDT is compared with the comparison circuit 29.
Is supplied to. The comparison circuit 29 corresponds to the first circuit shown in FIG.
In the same manner as in the above embodiment, the date / time information RDT at the time of reproduction supplied from the date / time information detection circuit 28 and the arithmetic circuit 8
6 compares the expiration date information PDT supplied from the control unit 6 and sends the control signal to the signal cutoff circuit 30 and the character generator 3.
Supply to 4. The operations of the signal cutoff circuit 30 and thereafter and the character generator 34 are the same as those in the first embodiment.

As described above, according to the second embodiment, when recording / reproducing an information signal supplied through the transmission line and having a limited reproduction period, the supplied digital information is recorded. The date / time information and its relative reproduction effective period information are recorded together with the main information, and the date / time information at the time of recording and its relative reproduction effective period information are reproduced at the time of reproduction. It is possible to calculate a typical reproduction expiration date, and to interrupt the output of reproduction digital information when the date and time at the time of reproduction exceed the reproduction expiration date. As a result, it is possible to prevent the reproduction of the information beyond the limited range of the period and protect the copyright of the transmission information (recording / reproduction information). In addition, since the date and time information at the time of reproduction, which is the criterion for determining the expiration date, is supplied from the above transmission line, the user cannot change the date and time at the time of reproduction, so it is correct. You can judge the expiration date.

In the second embodiment, ID8 to IDF 8 shown in FIG. 4 are used to record the reproduction valid period information.
A byte index signal is allocated and recorded / reproduced as year, month, day, and time information, but in many cases, the effective period may be in units of hours or days. Therefore, in that case, instead of recording the actual time or number of days information in the index signal,
For example, if 1 byte of ID8 shown in FIG. 4 is assigned to the validity period information and ID8 is “00”, the following ID
9 to IDF represent the valid period of any year, month, day, and time. When ID8 is other than "00", "01" is 1 hour, "02" is 3 hours, and "03" is 6 hours. , “04” is a half day, “05” is a day, “06” is a day, and so on. It is also possible to represent a plurality of specific valid periods with a 1-byte index signal. In that case, The index signal can be reduced or used for other purposes.

Furthermore, in the case of a system in which the effective period corresponds to only a fixed effective period such as one day from the information recording time, the index signal shown in FIG. All you need is the date and time information. In this case, the valid period information detection circuit 84 shown in FIG. 7 is not necessary, and the arithmetic circuit 86 adds a fixed day to the date and time information at the time of information recording supplied from the recording date and time information detection circuit 85. Thus, the absolute reproduction expiration date information PDT can be generated.

Further, in the above-mentioned embodiments, since absolute date / time information supplied via the transmission line at the time of reproduction is required, it is desirable that this transmitted date / time information can be always easily detected. Therefore, for example, even in the case where the main digital information signal is subjected to user-specified confidential processing and then transmitted, the absolute date / time information may be user-free, non-secreted, or sent in another channel.

Next, a third embodiment will be described.
The major difference of the third embodiment from the first or second embodiment is the generation means of the date and time information at the time of reproduction compared with the expiration date information. In the previous embodiment, the date and time information at the time of reproduction is always transmitted by the transmission line 37.
In contrast to the case where the information is supplied from the transmitting station side 36 via the, in the third embodiment, means for generating absolute date and time information inside the information recording / reproducing apparatus 47. Is provided. Hereinafter, a detailed description will be given with reference to FIG. FIG. 8 is a block diagram showing the structure of an information recording / reproducing apparatus to which the present invention is applied. In FIG.
The blocks designated by the same reference numerals as the blocks shown in FIG. 1 or FIG. 7 have the same or similar functions as the blocks in FIG. The apparatus of FIG. 8 is different from the apparatus of FIG. 1 in that it is a means for generating absolute date / time information at the time of reproduction supplied to the comparison circuit 29. This is the point that the generation circuit 87 is provided. The operation of the date / time information generating circuit 87 will be mainly described below.

In this embodiment, the date / time information detecting circuit 28 extracts the date / time information RDT from the transmitted index signal and supplies it to the date / time information generating circuit 87. The date / time information generation circuit 87 generates a stable clock by the crystal oscillator 88, and generates date / time information by a timer using this clock. The date / time information generating circuit 87 generates absolute date / time information preset by the date / time information RDT supplied from the date / time information detecting circuit 28. The absolute date / time information is supplied to the comparison circuit 29 at the time of reproduction and compared with the expiration date information included in the reproduction signal. The operation after the comparison circuit 29 and the signal cutoff circuit 30 is the same as that of the first or second embodiment described above.

The circuit for generating the date / time information as described above is often provided in the current VTR, for example, in order to realize timer reserved recording, but the date / time information generation circuit in the current VTR is used. The date and time presets can be set freely by the user. Therefore, if the user can freely set the date and time in the date and time information generation circuit 87 of the present embodiment, as in the case of the current VYR, the date and time information can be reproduced when pirated information that has been expired is desired to be reproduced. It is conceivable to preset the date and time of the generating circuit 87 within the expiration date. In this case, the copyright protection of the recorded information cannot be maintained. So, as a means to solve this problem,
The date / time information generating circuit 87 is configured to be preset only with the absolute date / time information supplied via the transmission line. Alternatively, when both the preset by the user and the preset by the date / time information supplied via the transmission line are enabled, the date / time information generation circuit 87 is used when the information having the reproduction expiration date is reproduced. If the most recent preset is based on the date and time information supplied via the transmission line, it can be played back as it is. If the most recent preset is from the user, the playback signal is blocked by the signal blocking circuit 30 and This can be dealt with by making the generator 34 generate information for prompting presetting in the date and time information supplied via the transmission path. The former configuration can be realized simply by not providing a preset mechanism by the user, and the latter case can be realized by using a flip-flop function or the like for detecting the preset by the user and the preset by the date / time information from the transmission path. .

As described above, according to the third embodiment, when the information signal supplied via the transmission line and having the limited reproduction period is recorded and reproduced, the information signal is compared with the expiration date information at the time of reproduction. Since the date and time information at the time of reproduction can be generated inside the device, it is not necessary to always supply the date and time information from the transmission line at the time of reproduction, and the device can be used for portable use etc. spread. Then, when reproducing the information with the expiration date set, it is possible to always use the absolute correct date / time information so that the generation of the date / time information at the time of reproduction can be prevented from being pirated. The copyright of the reproduction information) can be protected.

[0045]

As described above, according to the present invention, in the information recording / reproducing apparatus for recording / reproducing the information supplied via the transmission path, the reproduction expiration date of the transmitted and recorded information is set, When the expiration date has passed, the reproduction signal of the transmission information is cut off, and the copyright of the supply information can be protected. As a result, it becomes possible to distribute a large amount of information such as video software at a low price through the digital information network, and in order to realize the development of the digital information network and the user needs to obtain a large amount of information at a low price. The effect is great.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of an information recording / reproducing apparatus of the present invention.

FIG. 2 is a configuration diagram showing a usage environment of the information recording / reproducing apparatus of the present invention.

FIG. 3 is a diagram showing an error detection / correction code structure and a block configuration of a recording information signal.

FIG. 4 is a diagram showing a configuration example of an index signal.

FIG. 5 is a block diagram showing configurations of a drum servo circuit and a capstan servo circuit.

FIG. 6 is a block diagram showing a configuration of a cutoff detection circuit for transmitted date / time information.

FIG. 7 is a block diagram showing a configuration of an information recording / reproducing apparatus of the present invention.

FIG. 8 is a block diagram showing a configuration of an information recording / reproducing apparatus of the present invention.

[Explanation of symbols]

 12 ... Channel selector 13,24 ... Demodulation circuit 14 ... PCM decoder 15,26 ... Index signal detection circuit 16,25 ... Digital signal processor 17,46 ... Modulation circuit 19 ... System controller 20 ... Drum Servo circuit 21 ... CTL generation / detection circuit 22 ... Capstan servo circuit 31 ... Memory circuit 27 ... Expiration date information detection circuit 28 ... Date / time information detection circuit 29, 80 ... Comparison circuit 30 ... Signal interruption Circuit 32 ...... MPEG decoder 33 ...... DA converter 34 ...... Character generator 37 ...... Transmission line 42 ...... PCM encoder 43 ...... Calendar timer circuit 44 ...... Controller 45 ...... Expiration date information generation circuit 79 ...... Latch circuit 81 ...... Signal synthesis circuit 84 …… Detection of valid period information Circuit 85 ... Recording date / time information detection circuit 86 ... Calculation circuit 87 ... Date / time information generation circuit

Front page continuation (72) Inventor Hiroo Okamoto 292 Yoshida-cho, Totsuka-ku, Yokohama, Kanagawa, Ltd.Inside of Hitachi Media Visual Media Research Institute (72) Inventor Keiji Noguchi 292 Yoshida-cho, Totsuka-ku, Yokohama, Kanagawa Hitachi, Ltd. Video Media Laboratory (72) Inventor Hiroaki Ono 292 Yoshida-cho, Totsuka-ku, Yokohama, Kanagawa Stock Company Hitachi, Ltd.Video Media Laboratory (72) Inventor Jiro Owashi 292 Yoshida-cho, Totsuka-ku, Yokohama, Kanagawa Hitachi, Ltd. Visual Media Research Center (72) Inventor Takao Arai 292 Yoshida-cho, Totsuka-ku, Yokohama, Kanagawa Prefecture Hitachi Media Visual Media Research Center

Claims (7)

[Claims] 1. A first information signal, which is a main information signal supplied via a transmission line, and a first time period synchronized with time axis information such as a date and time attached to the first information signal. A recording means for recording the axis information signal, a reproducing means for reproducing the first information signal and the first time axis information signal, and a date and time supplied through the transmission line at the time of reproduction. Detection means for detecting a second time axis information signal which is time axis information, the first time axis information signal reproduced by the reproducing means, and the second time axis information signal detected by the detecting means. And a signal cut-off means for cutting off the reproduction output signal of the first information signal in accordance with the comparison signal of the comparison means. Exceeds a predetermined expiration date for the time axis information signal of In the case that, in the signal cutoff means, the information recording and reproducing apparatus being characterized in that so as to shut off the output of said first information signal. 2. A first information signal, which is a main information signal supplied via a transmission line, and a first information signal associated with the first information signal.
Recording means for recording the second information signal indicating the reproduction expiration date of the information signal, reproduction means for reproducing the first information signal and the second information signal, and supply via the transmission path during reproduction. Detection means for detecting a third information signal, which is time axis information such as date and time, and the second information signal reproduced by the reproducing means, and the third information detected by the detecting means. The third information signal, comprising: a comparison means for comparing with the information signal; and a signal cutoff means for cutting off the output of the reproduced first information signal according to the comparison signal of the comparison means. When the time axis information exceeds the reproduction expiration date which is the second information signal, the signal cutoff means cuts off the output of the first information signal. Playback device. 3. A first information signal, which is a main information signal supplied via a transmission line, and a first information signal associated with the first information signal.
Recording means for recording a second information signal indicating a reproduction effective period of the information signal and a third information signal which is time axis information such as date, time, etc., and the first information signal and the second information. Reproducing means for reproducing the signal and the third information signal, and detecting means for detecting the fourth information signal which is time axis information such as date and time supplied through the transmission line at the time of reproduction, Calculating means for calculating a reproduction expiration date from the second information signal and the third information signal reproduced by the reproducing means; reproduction expiration date information calculated by the calculating means; and detection means detected by the detecting means. No. 4 information signal, and a signal cutoff unit for cutting off the output of the reproduced first information signal according to the comparison signal of the comparison unit. Time axis information that is If it exceeds the playback expiration date calculated by the stage in the signal cutoff means, the information recording and reproducing apparatus being characterized in that so as to shut off the output of said first information signal. 4. A first information signal, which is a main information signal supplied via a transmission line, and a first information signal associated with the first information signal.
Recording means for recording a second information signal indicating a reproduction expiration date of the information signal, reproduction means for reproducing the first information signal and the second information signal, and a time axis such as date and time. A time axis information generating means for generating a third information signal, which is information, compares the second information signal reproduced by the reproducing means with the third information signal generated by the time axis information generating means. Comparing means and a signal cutoff means for cutting off the output of the reproduced first information signal according to the comparison signal of the comparison means, and the time base information which is the third information signal is An information recording / reproducing apparatus characterized in that, when the reproduction expiration date, which is the second information signal, is exceeded, the output of the first information signal is interrupted by the signal interrupting means. 5. The time axis information such as date and time in the time axis information generating means is preset by the time axis information such as date and time supplied through the transmission line. The information recording / reproducing apparatus according to claim 4. 6. A display information generating means for displaying that the reproduction expiration date of the first information signal has expired when the interruption device interrupts the first information signal. The information recording / reproducing apparatus according to any one of claims 1 to 5. 7. The comparing means is always provided when the second time axis information signal, which is time axis information such as date and time supplied to the comparing means through the transmission line, is not supplied. 2. The information recording / reproducing apparatus according to claim 1, wherein a control signal is supplied to the interruption means so as to interrupt the reproduced first information signal.