JPH04147455A - Magnetic recording and reproducing device - Google Patents

Abstract

PURPOSE:To specify one reel of a magnetic tape to be preventive of partial erroneous erasing by inhibiting all signal recording and signal erasing during a reproducing period when a protect signal recorded on a magnetic tape is regenerated. CONSTITUTION:The protect signal is recorded in a user data write area via a control head 5 in accordance with a CTL recording system. A protect signal regenerating head 7 is connected with a recording/erasing inhibit circuit 13 via a protect selecting switch 12, and by closing the protect selecting switch 12 to send the regenerated protect signal to the recording/erasing inhibit circuit 13, a recording circuit 10 can be stopped in its operation for a whole width erasing head 6 and a rotary magnetic head 3, and even under a recording mode, recording and whole width erasing can be stopped. By this method, the erroneous erasing preventing measure can be given to only a spot which is considered necessary in the magnetic tape.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a magnetic recording and reproducing apparatus that is capable of specifying only a portion of a negative volume of magnetic tape to prevent accidental erasure of only a portion deemed necessary.

[Prior Art] A magnetic recording/reproducing device using a magnetic tape such as an audio tape or a video tape as a recording medium is indispensable as a recording medium for audio and video. In order to prevent the previously recorded contents from being erased by mistake, these magnetic tapes are equipped with an accidental erasure prevention claw on a part of the cassette half. It is devised to prevent new recording from a magnetic recording/reproducing device on the magnetic tape that has been removed.

[Problems to be Solved by the Invention] The above-mentioned conventional magnetic recording and reproducing device determines whether or not recording is possible on a magnetic tape by mechanically sensing the presence or absence of an accidental erasure prevention claw formed on a part of the tape cassette. Therefore, it is possible to take measures to prevent erroneous erasure of the entire negative volume of the magnetic tape. However, it is not possible to make only part of the magnetic tape subject to accidental erasure prevention, and even if the accidental erasure prevention designation is canceled, cellophane tape or the like must be attached to the cassette half as a substitute for the accidental erasure prevention claw. However, there have been problems such as the work required to do so is troublesome.

[Means for Solving the Problems] The present invention solves the above problems, and is a magnetic recording/reproducing device for recording or reproducing information on a magnetic tape as a medium, in which an arbitrary section of the magnetic tape can be specified. a protect signal recording means for recording a protect signal to prevent erroneous erasure on the magnetic tape; and a recording/erasing means for reproducing the protect signal recorded on the magnetic tape and prohibiting any signal recording or signal erasure during the reproduction period. It is characterized by having a prohibition means.

[Function] The present invention specifies an arbitrary section of a magnetic tape and records a protect signal to prevent erroneous erasure.
When the protect signal recorded on the magnetic tape is reproduced, all signal recording and signal erasure is prohibited during the reproduction period, thereby making it possible to designate partial accidental erasure prevention for one roll of magnetic tape. .

[Example] Hereinafter, an example of the present invention will be described with reference to FIGS. 1 to 3. FIG. 1 is a circuit diagram showing the main parts of an embodiment of the magnetic recording/reproducing apparatus of the present invention, and FIG.
FIG. 3, which is a diagram showing a recording pattern of a magnetic tape partially protected against erroneous erasure, is a simplified flowchart for explaining the operation of the magnetic recording/reproducing apparatus shown in FIG. 1.

In FIG. 1, a magnetic recording/reproducing apparatus 1 writes a protect signal in a control track of a magnetic tape 2, thereby making it possible to prevent erroneous erasure in any section. A normal audio track and a control track are formed on the magnetic tape 2 with a video track in between, and a rotating magnetic head 3 is used to record signals on each track. Audio head 4. The control head 5 corresponds to each position, but in this embodiment, the full-width erase head 6 is placed first along the tape running direction, followed by the rotating magnetic head 3, and finally the audio head 4 and the control head 5 are placed in the same line. It is placed in the

However, in this case, a magnetic head for the purpose of reproducing and erasing a protect signal is arranged at an appropriate position in the above-mentioned head series. That is, the protect signal reproducing head 7 is disposed immediately before the full-width erase head 6, and the protect signal erase head 8 is disposed immediately before the control head 5. The protection signal is recorded using the CTL recording method.
via the control head 5 according to the formula. In this CTL recording method, as shown in Figure 2, a 16-bit user data writing area is provided between the header writing area and the time code data writing area as a user data writing area that can be used freely by the knee and the user. A writing area of 0000 to 9999 is given.
It is now possible to write each digit of a decimal number up to 4 bits using 4-bit binary code. Therefore, in this embodiment, 9999 is set as a protect signal, and this protect signal is recorded in the user data write area.

A recording circuit 10 and a reproducing circuit 11 are connected to the rotating magnetic head 3 via a changeover switch 9 that switches between recording and reproduction. On the other hand, the protect signal reproducing head 7
A recording/erasing prohibition circuit 13 is connected to the recording circuit 10 via a protection selection switch 12. By closing the protection selection switch 12 and sending a protect signal to the recording/erasure inhibition circuit 13, full-width erasure is performed on the recording circuit 10. The action on the head 6 and the rotary magnetic head 3 can be stopped, and recording and full-width erasing can be stopped even in the recording mode. A protect signal recording circuit 15 is connected to the control head 5 via a protect switch 14, and by closing the protect switch 14, a protect signal can be sent to the control head 5. Further, a protect signal erasing circuit 18 is connected to the protect signal erasing head 8 via a protect canceling switch 16, and by closing the protect canceling switch 16 and playing back, only the protect signal can be selectively erased. I can do it.

By the way, when protecting a necessary part while playing back the magnetic tape 2, the magnetic tape 2 is first rewound to the beginning of the part to be saved, as shown in FIG. 3(A). Next, the protect switch 14 is closed and playback is started. In this case, the control head 5 writes a protect signal in the user data writing area that was blank until then, so the user opens the protect switch 14 when the last part of the storage area is reached while viewing the reproduced image, and then Stop playback. Thereby, the portion of the magnetic tape 2 desired by the user can be protected.

Next, when protecting the necessary portions while recording on the magnetic tape 2, first close the protect switch 14 and then start recording, as shown in FIG. 3(B). Then, at the last location desired to be saved, recording is stopped or the protect switch 14 is opened. Thereby, a desired location on the magnetic tape 2 can be protected.

On the other hand, when canceling the protection while reproducing the magnetic tape 2, as shown in FIG. 3(C), the magnetic tape 2 is first rewound to the beginning of the part from which protection is to be canceled. Next, the protection release switch 16 is closed and playback is started. In this case, the protect signal eraser 17 erases the protect signal written in the control track, so the user opens the protect release switch 16 when the user reaches the last part of the protection release area while viewing the reproduced image. Then stop playback.

This allows the user to select the desired location on the magnetic tape 2.
protection can be removed.

Also, when recording on the magnetic tape 2 and canceling the protection of necessary locations, it is preferable to follow the same procedure as above, as shown in FIG. 3(D).

Further, the magnetic recording/reproducing apparatus 1 can release the protection while fast forwarding the magnetic tape 2 as shown in FIG. You can also remove protection while rewinding. However, in the case of fast-forwarding, for the convenience of the user, the fast-forwarding is automatically stopped at the end of the saved portion. In addition, when canceling by rewinding, the tape counter (not indicated) will be displayed at the beginning of the protection that you want to cancel.
, and then play or fast-forward the magnetic tape 2 to the last part you want to unprotect. Next, by closing the protection release switch 16 and rewinding, protection can be released during the process of rewinding to the reset position of the tape counter.

Furthermore, as shown in FIG. 3(G), it is also possible to record while canceling protection, and to perform protection in parallel with this recording. In this case, the magnetic tape 2 is rewound to the point where protection is to be removed, and both the protection release switch 16 and the protection switch 14 are closed. Then, recording can be performed in this state.

Further, even during timer recording, as shown in FIG. 3(H), by closing the protect switch 14, protection can be applied during the timer recording period. Conversely, as shown in FIG. 3(I), it is also possible to instruct parallel processing of protection release and protection at the time of timer reservation recording.

Note that when the protect selection switch 12 is opened, even if the magnetic tape 2 is already protected, the measures to prevent accidental erasure are abandoned regardless of the protected location, so overwriting can be performed. . Furthermore, a protect selection switch 12 and a protect release switch 16
By closing both, it is possible to prevent careless recording, and at the same time, it is possible to make protection effective until playback, and then cancel the protection. In other words, since the protect signal is erased for the first time after being played back for - degrees, for a large number of magnetic tapes 2 that had previously been piled up with only recordings, different content is being read one after another without being played back even for - degrees. It is possible to eliminate inertial recording such as repeatedly recording.

In this way, the magnetic recording/reproducing device 1 has a magnetic tape 2.
In addition to recording a protect signal to prevent erroneous erasure by specifying an arbitrary section of Because it is configured to prohibit
Instead of applying accidental erasure prevention to the entire roll of magnetic tape 2 as in the conventional mechanical erasure prevention method, by recording a protect signal only in the necessary parts of the magnetic tape 2, Measures to prevent accidental erasure can be applied only to the parts of 2 that are considered necessary, and as the image quality of the 3x mode improves, magnetic tapes 2 recorded over long periods of time tend to pile up in ordinary households. You can easily specify only the parts that really need to be saved by pressing a button, and if you erase the protect signal from the entire magnetic tape 2 or partially, it can be erased mechanically. Free overwriting can be performed again without using the prevention claw for reproduction.

In the above embodiment, the protect signal erasing head 8 may be absorbed and integrated into the control head 5, and in that case, the protect signal erasing circuit 17 and the protect signal recording circuit 15 may also be configured as one unit.

[Effects of the Invention] As explained above, the present invention specifies an arbitrary section of a magnetic tape and records a protect signal to prevent erroneous erasure, and also allows the protect signal recorded on the magnetic tape to be reproduced. Since the structure prohibits all signal recording and signal erasure during the playback period, it is not necessary to apply accidental erasure prevention to the entire roll of magnetic tape as in the conventional mechanical erasure prevention method. - By recording protect signals only in the necessary parts of the magnetic tape, it is possible to take measures to prevent accidental erasure only in the necessary parts of the magnetic tape, and as the image quality improves in 3x mode. Nowadays, even in ordinary households, there is a tendency for magnetic tapes that have been recorded over long periods of time to accumulate in piles, so it is possible to easily specify only the parts that truly need to be saved with the touch of a button, or to save the entire magnetic tape. Once the protect signal is completely or partially erased, excellent effects such as free overwriting can be achieved again without mechanically using the erroneous erasure prevention claw as a substitute for reproduction.

[Brief explanation of the drawing]

FIG. 1 is a circuit configuration diagram showing a main part of an embodiment of a magnetic recording/reproducing apparatus of the present invention, FIG. 2 is a diagram showing a recording pattern of a magnetic tape partially protected against accidental erasure, and FIG. The diagram is
2 is a simplified flowchart for explaining the operation of the magnetic recording and reproducing apparatus shown in FIG. 1. FIG. 201. magnetic tape, 5. ,,control head,7
．． ,,protect signal reproducing head, 1301. Recording/erasing prohibition circuit.

Claims (1)

[Claims] A magnetic recording/reproducing device for recording on or reproducing information from a magnetic tape as a medium, comprising: a protect signal recording means for specifying an arbitrary section of the magnetic tape and recording a protect signal for preventing erroneous erasure; and the magnetic tape. 1. A magnetic recording/reproducing apparatus comprising a recording/erasing prohibiting means for reproducing a protect signal recorded on a magnetic recording medium and prohibiting any signal recording or erasing during the reproduction period.