JPH04155658A - Recording/reproducing apparatus - Google Patents

Abstract

PURPOSE:To achieve compatibility of machine, to protect copyright and to enhance privacy by mnemonically encoding input record information, detecting mnemonically encoded reproduction information and decoding. CONSTITUTION:A password input unit 10 receives a password for designating mnemonically encoded information according to a scramble mode. In reproduction mode, control track on a video tape 100 is read out and reproduced and when a pass word detector 11 detects the header of a control signal, a password comparator 12 checks a password identical to the input password being recorded following to the head. In case of an identical password, descramble reproduction is executed by a controller 13 based on that password so that the image data in the vertical direction are exchanged line by line according to a line address data on a lookup table 14.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Fields] The present invention relates to recording and reproducing devices, particularly magnetic media recording and reproducing devices, such as video tape recorders, audio tape recorders, etc., which record video signals, audio signals, etc. on recording media. The present invention relates to encryption technology and decryption technology for a recording/playback device that can record, read, and play back.

[Prior Art] As conventional encryption techniques and decryption techniques, for example, the following encryption techniques and decryption techniques for broadcasting transceivers are known.

In other words, when receiving Direct Satellite Broadcasting (DBS) or CATV, the source broadcasting station superimposes a special signal on the broadcast radio wave and transmits it to prevent unauthorized viewing. Encryption technology was used to distort the signal or audio signal, making it impossible to receive the video or audio correctly.

On the other hand, since broadcasts from general broadcast stations are usually transmitted and received without encryption, a receiver that can receive broadcasts from general broadcast stations as well as direct satellite broadcast stations is - Many receivers have a descrambling function added to the standard tuner function, and such receivers can correctly receive both broadcast radio waves carrying special signals to prevent unauthorized viewing, as well as general broadcast radio waves. Therefore, video and audio can be received correctly.

However, in recent years, with the spread of video tape recorders, audio tape recorders, etc., many users have come to use these devices.

With the increase in the number of users of magnetic media recording and reproducing devices, the purposes for which magnetic media recording and reproducing devices are used are becoming more diverse. Regarding recording, etc., magnetic media recording, reading, and reproducing devices that are suitable for recording, reading, and reproducing such recorded information are magnetic media that can be recorded, read, and reproduced in a manner that can only be reproduced and referenced by specific persons. Recording and reproducing devices are now in demand.

[Problems to be Solved by the Invention] However, conventional recording and reproducing devices have a problem in that they do not protect the copyright of the recorder while maintaining compatibility with magnetic media recording and reproducing devices such as general video tape recorders. There has never been a recording/reproducing device that can record, read, and reproduce highly confidential records that can be reproduced and referenced only by specific persons.

The present invention was developed in view of the above situation.

Targets recordings that are compatible with magnetic media recording and reproducing devices such as general video tape recorders, protect the copyright of the recorder, and are highly confidential and can only be played and referenced by specific persons. The object of the present invention is to obtain a recording/reproducing device that performs recording, reading, and reproducing.

[Means for Solving the Problems] In order to achieve the above object, the recording and reproducing apparatus according to the present invention has two features: an encryption means for encrypting recorded information input from the outside according to a predetermined rule during recording; an encryption detection means for detecting whether or not the read/output information read out/reproduced from the recorded recording medium is encrypted according to the predetermined rule; and decoding means for decoding the readout information according to the predetermined rule.

[Action Co. Therefore, according to the recording/reproducing apparatus of the present invention.

At the time of recording, the recorded information input from the outside is encrypted by an encryption means according to a predetermined rule, and when reading from a recording medium encrypted and recorded by the encryption means, the read information is read by an encryption detection means.・It becomes possible to detect whether the reproduced read information is encrypted and to decode the read information read and reproduced from the recorded recording medium by the decryption means according to the predetermined rules. .

[Example] An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram of a magnetic medium recording and reproducing apparatus which is an embodiment of the recording and reproducing apparatus of the present invention.

In FIG. 1, the magnetic medium recording/reproducing apparatus of the present invention has a switching key to a scramble mode for encrypting recorded information, and a numeric keypad for inputting a password, which is encrypted information consisting of three digits. a password input device (10) having a
1), and compares whether the password input from the password input device (10) during playback matches the password detected from the read information read out and played back from the recording medium by the password detection device (11). A password comparator (12) that scrambles the video signal input from the video signal input terminal (101) during recording according to instructions from the password input device (10), and scrambles the video signal input from the video signal input terminal (101) during recording, and ), and data indicating how to perform scrambling or descrambling according to the password in accordance with the comparison output from the password comparator (12). A look-up table (14) having a look-up table (14), which records the video signal input from the video signal input terminal (101) on the video tape (100) during recording, or reads and plays the video signal from the video tape (100). A recording/reproducing circuit (15) and a changeover switch (15) that switches the signal line and control line depending on the operating state of either recording mode or playback mode.
6), a changeover switch (17) that switches between a signal line and a control line depending on whether or not the scramble mode is specified by the password input device (10), and a head, which is a known component in conventional magnetic media recording and reproducing devices. Consists of a switching pulse generator (18), a phase comparator (19), a control head (20), a reference oscillator (21), a phase comparator (22), and a servo control mechanism (23), Furthermore, the servo control mechanism (23) includes motor drive amplifiers (24) (27), a drum motor (25), speed servo circuits (26) (28), and a capstan motor (
29).

Next, the operation will be explained. In the magnetic medium recording and reproducing apparatus of the present invention configured as described above, the video head helically scans the video tape (100) to form a video track, and information is recorded on the video track. , Recording information is being recorded. In such a magnetic medium recording and reproducing apparatus, a control track is formed at the lower end of the video track of the video tape (100) so that the video track can be correctly traced during reproduction.

To explain this operation in more detail using FIG. 1, during recording, the head switching pulse generator (18) generates a pulse based on the vertical synchronization signal of the video signal input from the video signal input terminal (101). A motor drive amplifier (24) and a speed servo circuit (26) are connected to the drum having a video head (not shown).
), servo control is performed via the drum motor (25).

Furthermore, a control signal formed based on the vertical synchronization signal is recorded on the control track of the video track by the control head (20).

On the other hand, during reproduction, the oscillation output generated from the reference oscillator (21) and the head switching pulse generator (18)
A phase comparator (19) compares the phase with the head switching pulse from the head switching pulse, and the drum servo control, which is phase-controlled to a constant value, is connected to the motor drive amplifier (24), speed servo circuit (26), and drum motor (25). It is done through.

Furthermore, for capstan servo control, the oscillation output from the reference oscillator (21) and the control head (2
The phase comparator (22) compares the phase of the control signal regenerated by the motor drive amplifier (22) with the control signal regenerated by the motor drive amplifier (22).
6) Servo control is performed on the capstan via a speed servo circuit (28) and two capstan motors.

With the above control, when playing back a videotape (100) recorded on another magnetic medium recording/playing device,
Tracking of the videotape (100) is performed correctly even when the mode is changed to EP.

Next, scramble φ descrambling control device (13)
The scramble/descramble control will be explained using FIG. 2, which is a block diagram of the scramble/descramble control device (13) showing the internal configuration of the scramble/descramble control device (13).

The scramble/descramble control device (13) includes an analog-to-digital converter (31) that converts the video signal input from the video signal input terminal (101) from analog to digital, and an analog-to-digital converter (31).
Image memory (32) that stores the digital video signal converted from analog to digital by the clock input for one field, and scrambles or descrambles it for each line address and outputs it.
During recording, the password comparator (12) corresponds to the 3-digit password input, and during playback, the password is manually input f! (10) and password detection device (1
1), only if there is a match in the password comparator (12), the 3-digit password is stored in the image memory (32) in the order of the line address specified from the lookup table (14). 1
A control unit (33) that sends image data for one field and controls the image memory (32) for each field pulse from the analog-to-digital converter (31), and scrambles or decodes the image data from the image memory (32). It consists of a digital-to-analog converter (34) that converts the scrambled video signal from digital to analog.

Next, the operation of recording and reproducing the password, which is encrypted information, on the control track will be described below, based on FIG. 3, which shows the control signals recorded and reproduced by the control head (20).

In the magnetic medium recording/reproducing apparatus of the present invention, the recording signal shown in FIG. 3 is sent to the control head (20) during recording.

In Figure 3, a square wave formed by the vertical synchronization signal is sent to the control head (20) during normal recording, but when scramble mode operation is performed, the password input device (10) specifies the To record the entered password, a square wave with a special duty ratio recorded as a header, and then a square wave with a duty ratio corresponding to the 3-digit password are sequentially switched to the control head (2o). This indicates that the message will be sent to

Furthermore, during reproduction, the pulses of the control track reproduced by the control head (20) as shown in FIG. 3 are recorded at the above-mentioned duty ratio during recording, and therefore can be distinguished from normal control signals. I understand.

The control track pulses reproduced by the control head (20) serve as special pulses for the servo control system (22). Therefore, the control head (20
) The servo may not work correctly depending on the pulses of the control track played back, but since no image information is recorded on the video track corresponding to the control track of the video tape (100) on which the password is recorded, there is no particular problem. do not have.

Next, the operation of the magnetic medium recording/reproducing apparatus shown in FIG. 1 will be explained below using the flowchart shown in FIG.

First, it is checked whether the scramble mode is designated by the state of the scramble mode switching key that instructs encryption on the password input device (10) (step 51).

If the check results in the scramble mode, a password indicating encrypted information consisting of three digits is input using the ten keys of the password input device (10) (step 52).

Next, the state of the playback mode key or the record mode key that designates the operating mode of the magnetic medium recording/playback device (not shown) is checked to determine whether it is the playback mode or the record mode (steps 53 and 57).

If the check in step 53 indicates that the playback mode is selected, the magnetic medium recording/playback device of the present invention reads out and plays back the control track of the video tape (100) to check whether a password is recorded on the control track, and stores the password. A detection device (11) checks whether there is a header in the control signal. In order to shorten the search time, these operations are performed by fast forwarding or rewinding (step 54).

Thereafter, if a header is detected, a password comparator (12) compares whether the same password as the password entered by the password input device (10) is recorded after the header ( Step 55).

If the same password is detected by the password comparator (12), the scramble/descramble control device (13) converts vertical image data according to the line address data in the lookup table (14) based on the password. Descramble playback is performed to replace each line (step 56). Note that, at this time, address data for restoring the line to the original line exists in the look-up table (14) for the line in which the image data was replaced during recording.

In the check of step 55, the password comparator (
If the same password is not detected by step 12), it is checked whether the entire tape search of the videotape (100) has been completed (step 60).

If the search across the tape of the videotape (100) has not been completed, a return is made to step 54 to continue the search operation until completion.

On the other hand, if the state of the playback mode key is checked (step 53) and it is determined that the playback mode is not in effect, the state of the record mode key is checked to determine whether the mode is in the record mode (step 57).

Then, if it is not the recording mode, the process returns to step 53.

If the recording mode is determined, the password input device (10)
A header is added in front of the three-digit password input in step 58, and the signal is sent to the control head (20) (step 58).

then accessing a lookup table (14) based on the password via a password comparator (12);
Based on the line address data from the lookup table (14), the scramble/descramble control device (
13) Scramble recording is performed by replacing the vertical image data line by line (step 59).

In the above embodiment, the magnetic medium recording/reproducing device is shown as a video tape recorder, but it may also be an audio tape recorder or the like.

Furthermore, although the description has been made using a videotape as a recording medium corresponding to a videotape recorder, the same applies to CDs, optical recording media, laser recording media, and the like.

Furthermore, in the above embodiment, the scrambling method is a line partition method, but a line rotation method,
A scrambling method such as a line translation method or a scanning line backward method may also be used.

In the above embodiment, the password is recorded on the control track, but the password may be recorded on the video track or the audio track. In that case, the password will be recorded using the video head or audio head instead of the control head.

Further, in the above embodiment, numbers are used for the password in order to comply with the scrambling rules, but alphabets or the like may be used instead.

In addition, line replacement scrambling is shown as applying a rule corresponding to a password for each field, but it is also possible to apply a rule corresponding to a password for each multiple scanning line, or to apply a rule corresponding to a password for each frame. The rules may also be applied.

[Effects of the Invention] As explained above, according to the recording and reproducing apparatus of the present invention,
At the time of recording, the recorded information inputted from the outside is encrypted by the encryption means according to a predetermined rule, and at the time of reading from the recording medium encrypted and recorded by the encryption means, the information is read by the encryption detection means.・Configured to detect whether or not the reproduced read information is encrypted, and to enable the decryption means to decrypt the read information read and reproduced from the recorded recording medium according to the predetermined rules. Therefore, while maintaining compatibility with magnetic media recording and reproducing devices such as general video tape recorders, it also protects the copyright of the recorder and is highly secure, allowing playback and reference only by specific persons. The present invention is effective in that it is possible to obtain a recording/reproducing device capable of recording, reading, and reproducing π1 records.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a magnetic medium recording and reproducing device determined by an embodiment of the recording and reproducing device of the present invention, and FIG. 2 shows the internal configuration of the scramble/descramble system ft (13) shown in FIG. 1. Scramble/rus crumple control device (1
3), the block diagram of Figure 3 shows the password or two on the control track based on the control signal recorded and reproduced by the control head (20) shown in Figure 1.
FIG. 4 is a flowchart showing the operation of the magnetic medium recording and reproducing apparatus shown in FIG. 1. In the figure, (10) is a password input device, (11)
is a password detection device, (12) is a password comparator,
(13) is a scramble/desk ripple control device, (14) is a look-up table, (15) is a recording/reproducing circuit, and (16). L (17) is a changeover switch, (18) is a head switching pulse generator, (19) and (22) are phase comparators, (20) is a control head, (21) is a reference oscillator, and (23) is a servo control. Mechanism, (24), (
27) is the motor drive amplifier, (25) is the drum motor, (26), (2g) is the J speed servo circuit,
(29) is the capstan motor, (31) is the analog motor.
Digital converter, (32) is image memory, (3B) is digital-to-analog converter, (34) is controller section,
(100) is a video tape, (101) is a video signal input terminal, and (102) is a video signal output terminal. In addition, in FIG. 1, the same reference numerals indicate the same or equivalent parts. Agent Patent Attorney Yoshi 1) Kenji (2 others) Foot Roll Signal No.

Claims (1)

[Scope of Claims] A recording and reproducing apparatus that records recorded information input from the outside onto a recording medium, and also reads and reproduces recorded information from the recorded recording medium, comprising the following: an encryption means for encrypting recorded information; an encryption detection means for detecting whether the read information read out and reproduced from the recorded recording medium is encrypted according to the predetermined rule at the time of reading; 1. A recording and reproducing apparatus comprising: decoding means for decoding read information read and reproduced from a recorded recording medium according to the predetermined rule.