JPH0325778A - Magnetic tape and magnetic tape device therefor - Google Patents

Abstract

PURPOSE:To prevent information on part of a tape from being erroneously erased by recording or reproducing an erroneous erasure prevention signal in a requested position on the tape and preventing the information from being erased in the reproducing position. CONSTITUTION:First the erroneous erasure prevention signal is recorded in the desired position on the tape by an erroneous erasure prevention recording head 9. After that, new information is rerecorded only when an erroneous erasure prevention signal reproducing head 8 does not reproduce the prevention signal. In addition, the magnetic tape 15 is reproduced, and information can not be erased in the position of the tape 15, where the erroneous erasure prevention signal is reproduced. In that manner, information on part of the tape 15 is prevented from being erroneously erased by recording or reproducing the erroneous erasure prevention signal on the tape 15.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a magnetic tape device that uses magnetic tape such as video tape and audio tape.

Conventional technology In recent years, in the field of magnetic recording, digitalization, miniaturization,
As the performance of magnetic recording devices such as longer recording times is increasing, the functions of magnetic recording devices are also increasing in variety and diversification.

With conventional magnetic recording, when you want to save the content recorded on a magnetic tape, you can erase it by mistake on the cassette that stores the magnetic tape as a means to prevent it from being accidentally erased. A prevention function is provided.

An example of the above-mentioned conventional method for preventing erroneous erasure will be described below with reference to the drawings.

FIG. 6 is a rear perspective view of a cassette equipped with a function to prevent accidental erasure. In FIG. 5, 1 is the lower half and 2 is the upper half. 3 is a reel housed in the cassette. Reference numeral 4 denotes a hole for preventing accidental erasure, and numeral 5 denotes a piece for preventing accidental erasure.

The operation of the cassette constructed as described above will be explained below.

The erroneous erasure prevention hole 4 provided in the lower half 1 can be opened and closed by an erroneous erasure prevention piece 6 that can freely move left and right. If the cassette is inserted into a magnetic recording device with the accidental erasure prevention hole 4 closed, it will be possible to record, but if the cassette is inserted into the magnetic recording device with the accidental erasure prevention hole 4 open. Then, the magnetic recording device detects the erroneous erasure prevention hole 4 and becomes unable to record, thereby preventing erroneous erasure.

Problems to be Solved by the Invention However, in the above structure, it is impossible to re-record all parts of the magnetic tape stored in the cassette because it prevents erroneous erasure on the cassette side. There was a problem in that it was not possible to prevent partial erroneous erasure.

SUMMARY OF THE INVENTION In view of the above problems, an object of the present invention is to provide a magnetic recording device that prevents partial erroneous erasure of a magnetic tape by recording or reproducing an erroneous erasure prevention signal on the magnetic tape. It is.

Means for Solving the Problems In order to achieve the above objects, the present invention provides a magnetic tape in which an erroneous erasure prevention signal is recorded at a desired tape position, and a method for reproducing the erroneous erasure prevention signal from the magnetic tape. This is a magnetic tape device that does not allow erasure at the tape position.

According to the above-described structure, the present invention records or reproduces an accidental erasure prevention signal on a magnetic recording medium, thereby preventing errors from occurring not only in all parts but also in a part of the magnetic recording medium housed in a cassette. This means that erasure can be prevented.

EXAMPLES Hereinafter, examples of the present invention will be described with reference to the drawings.

FIG. 1 is a diagram showing a running system of a magnetic tape device according to a first embodiment of the present invention, and FIG. 2 is a diagram showing a recording pattern of a magnetic tape. In FIG. 1, 6 is a supply reel, 7 is a take-up reel, 8 is an accidental erasure prevention signal reproducing head, 9 is an accidental erasure prevention signal recording head, 1o is a full width erasing head, 11 is a rotating cylinder, and 12 is an audio control signal head,
13 is a CADESTAN, 14 is a BINCHROW, and 16 is a magnetic tape. In FIG. 2, 16 is a video track, 17 is an audio track, 18 is an audio control track, and 19 is an accidental erasure prevention track.

According to the first embodiment, the erroneous erasure prevention signal is recorded by the erroneous erasure prevention signal recording head 9 during the first recording. 2
When recording from the first time onward, the error erasure prevention signal reproducing head 8
After checking the presence or absence of an accidental erasure prevention signal, new information is re-recorded only if there is no accidental erasure prevention signal. The recording pattern of the magnetic tape is shown in FIG. 2, and the track is dedicated to preventing erroneous erasure or is also used as a control track. Therefore, it is also possible to edit the accidental erasure prevention signal alone later, and in such cases, the magnetic tape can be run at high speed to write, erase, or use the accidental erasure prevention signal to cue. Therefore, it is possible to use the erroneous erasure prevention signal more effectively.

FIG. 3 is a diagram showing the arrangement of magnetic heads on a rotary cylinder in a magnetic tape device having a rotary cylinder according to a second embodiment of the present invention, and FIG. 4 is a diagram showing a frequency spectrum. In FIG. 3, 20 is a rotary cylinder, 21 is a recording/reproducing CH1 head, 22 is a recording/reproducing CH2 head, 23 is an erasing head, and 24 is an erroneous erasure prevention signal read head.

In FIG. 4, 25 is a luminance signal, 26 is a color signal, and 27
is an FM audio signal, 28 is a tracking signal, and 29 is an erroneous erasure prevention signal.

In the second embodiment, when recording, first, the presence or absence of an erroneous erasure prevention signal is checked using the erroneous erasure prevention signal reading head 24, and then the erasing head 23 erases the signal, and then recording is performed. In this case, unlike the first embodiment, independent editing is not possible, and it is not possible to record only the accidental erasure prevention signal later. However, unlike the first embodiment, it is easy to add to the format of an existing magnetic recording device while maintaining upward compatibility.

In addition to the above-mentioned embodiments, the recording unit for the accidental erasure prevention signal can include: ■ Mixing it into the audio signal with a long length, ■ Performing deep recording with a long wavelength, ■ Inserting it into the vertical synchronization signal part of the image signal, ■ A rotating cylinder. For example, when the image signal wrapping angle is 180°, it is also possible to use a method such as increasing the wrapping angle by 1° and writing an erroneous erasure prevention signal there. Further, the erroneous erasure prevention signal can be temporally divided or compressed, or converted into a digital recording and mixed with other signals.

Effects of the Invention As described above, according to the present invention, by recording or reproducing an erroneous erasure prevention signal on a magnetic tape, erroneous erasure of the entire length of the magnetic tape can be prevented even if the magnetic tape is stored in a cassette. It is possible to obtain excellent effects such as not only prevention but also partial prevention of erroneous erasure.

[Brief explanation of drawings]

FIG. 1 is a plan view showing a running system of a magnetic tape device according to a first embodiment of the present invention, FIG. 2 is a pattern diagram showing a recording pattern of a magnetic tape according to a first embodiment of the present invention, and FIG. The figure is a head arrangement diagram of a magnetic tape device according to the second embodiment of the present invention, FIG. 4 is a diagram showing the frequency spectrum of the button according to the second embodiment of the present invention, and FIG. 6 is a diagram showing the conventional erroneous erasure prevention method. FIG. 3 is a rear perspective view of a cassette with functions. 8... Erroneous erasure prevention signal playback head, 9...
... Signal recording head to prevent accidental erasure. 6-・ 7 −・− 8 −・ 9 −1110 −11N 11112 −−・ a−・− H−・Sid tll drop 15 prevention platform g recording head treasure groove removal head 5i] k. Syringe 1 voice: Huntroll Akebono! Scrap head cap stamp pin +0-5 I6 -・- e 9 A'5
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Claims (2)

[Claims] (1) A magnetic tape on which an erroneous erasure prevention signal is recorded at a desired tape position. (2) A magnetic tape device which reproduces the magnetic tape according to claim 1 and has an erroneous erasure prevention signal that prohibits erasure at the tape position where the signal is reproduced.