JPS6314409B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a tape recorder that records or reproduces signals on a plurality of tracks in the width direction of a tape, in which a specific track of the tape is set as a recording/reproduction prohibited track.

One type of video tape recorder is one in which video signals are recorded and reproduced in a plurality of tracks in the longitudinal direction of a magnetic tape in the width direction. This type of videotape recorder uses other methods (e.g. diagonal scanning).
Like the video tape recorder, it can be used to record not only video signals but also digital signals, and has a storage capacity several to several ten times larger than floppy disks. In this video tape recorder, when recording and reproducing video signals, the magnetic head is moved track by track, but when recording and reproducing digital signals, the same track is often used continuously, and access time is reduced. To reduce the size, it is preferable to keep the tape running and the magnetic head in contact with the same track on the tape. However, if the magnetic head is always in contact with the magnetic tape, there is a problem in that the track portion in contact with the magnetic tape becomes demagnetized, resulting in a reduction in the reproduction output level during reproduction. In the case of video signals, even if the playback output level decreases, there is almost no effect on the image quality due to the afterimage effect in the eyes of the person viewing the playback image, but in the case of digital signals, for example, the signal is a combination of binary codes 1 and 0. There is also a possibility that an erroneous reproduction signal may be output. In the case of a floppy disk, when the disk is stationary, the head can be separated from the disk to prevent the above demagnetization.
In this video tape recorder, it is difficult to move the head away from the tape when not recording or reproducing, and if this was attempted, the structure would be complicated and problems would arise in terms of accuracy.

In view of the above points, the present invention prevents a specific track from being used for recording or reproducing among a plurality of tracks in the width direction of a magnetic tape, and when the tape is running and is not in the recording or reproducing mode, the magnetic head is moved to that specific track. By doing so, the magnetic head is not constantly in contact with the recording track, and demagnetization can be prevented.

The present invention will be explained below based on the drawings.

FIG. 1 is a block diagram when a video tape recorder is used as a data recording device, which records and reproduces data on multiple tracks in the longitudinal direction of a magnetic tape.
1 is a data processing device having a data calculation section 11 and a tape recorder control section 12; 2 is a video tape recorder as a data recording device; the mechanical section includes a capstan, a pinch roller, a magnetic head, and a motor as a driving source thereof; 21
and a control section 22 that controls the drive of this mechanism section 21 based on a control signal from a tape recorder control section 22 of the data processing device 1, and a control section 22 that records the calculation data from the calculation section 11 of the data processing device 1 on the tape. and a recording/reproducing section 24 including a recording/reproducing circuit for reproducing data recorded on the tape. The tape recorder control unit 22 includes a storage unit 22a that includes a memory (RAM) that stores the operating state of the mechanism unit 21 and a memory (ROM) that stores a predetermined program, and a control signal from the control unit 12 of the data processing device 1. and a calculation section 22b that calculates a tape recorder control signal based on the following.

FIG. 2 is a cross-sectional view of the main part of the magnetic head drive mechanism of the tape recorder, showing gear trains 5, 6, and 7 meshing with each other for transmitting the rotation of the step motor 4 fixed to the base 3 of the tape recorder main body. A threaded portion 8a is provided on the drive shaft 8 that is integrated with the gear 7.
A wedge-shaped engagement piece 9a fixed to the head mounting shaft 9 engages with this threaded portion 8a. The magnetic head 10 is attached to the upper end of the head mounting shaft 9, and its tip is connected to the tape guide 1.
The magnetic tape T is contacted through the opening 13a formed in 3. When a pulse is applied to the step motor 4, the magnetic head 10 rotates by a predetermined angle per pulse, and the rotation is transmitted to the drive shaft 8 via the gears 5, 6, and 7, and as a result, the threaded portion 8a When the head is rotated, the head mounting shaft 9 is moved up and down via the engagement piece 9a and moves by one track. in this way,
The magnetic head 10 moves by a number of tracks equal to the number of pulses applied to the step motor 4 with reference to a predetermined position (referred to as the zero point position).

Now, in FIG. 1, for example, an 8-bit tape recorder operation command signal and a strobe signal for strobe these signals are outputted from the control section 12 of the data processing device 1 and applied to the control section 22 of the tape recorder 2. Tape recorder operation command signals include drive command signal, stop command signal,
There are recording command signals, playback recording signals, etc. The recording command signals and playback command signals include address signals that indicate the recording position of data on the tape.
When the control section 22 of the tape recorder receives these command signals, it converts them into signals that drive the motor, pinch roller, drive solenoid, and head according to the program stored in the memory of the storage section 22a, and controls the mechanism section 21 and recording. It is output to the playback section 24. As described above, the position of the magnetic head 10 is determined by the number of pulses applied to the step motor 4. Therefore, the control section 22 of the tape recorder determines the position of the magnetic head 10 according to the program based on the address signal included in the recording/reproduction command signal. Detect track position. on the other hand,
Since the current position of the magnetic head is stored in the storage unit 22a of the control unit 22, the number of tracks to be moved can be calculated from the current track position and the track position determined from the address signal input to the calculation unit 22b. It is calculated and output to the mechanism section 21 as a step motor drive pulse. For example, the current track position is the 20th track, and the track determined from the address signal included in the playback signal is the 20th track.
Assuming that there are 115 tracks, the number of tracks the magnetic head moves is 115-20, which corresponds to 95 tracks, and the control section 22 provides 95 pulses to the step motor.

Nowadays, for example, tapes for video tape recorders are
It is assumed that data is recorded on 200 tracks, and the 100th track located approximately in the center is set as a recording/reproduction prohibited track. In order to prohibit recording and playback, as shown in the flowchart in FIG. If it is a recording command signal, it is determined whether the magnetic head is on the 100th track or not, and the process proceeds to another routine.
If the data is not on the 100th track, the mechanism unit 21 and the recording/reproducing unit 24 are put into the recording state, and the data output from the calculation unit 11 of the data processing device 1 is recorded.
If the magnetic head is on the 101st track, a command to move the magnetic head to the 101st track is output to the mechanism section 21 and recorded after the movement. In this way, recording of data is prohibited on the 100th track. The position of the magnetic head is always stored in the storage section 22a of the control section 22, and after data recording is completed, the position of the magnetic head is stored on the recording track and the 100th head.
A track difference with the track is calculated, and a pulse corresponding to the track difference is outputted from the control section 22 and applied to the step motor. In this way, the magnetic head is returned to the 100th track, which is a recording/reproduction prohibited track.

The same applies when a reproduction command signal is output from the data processing device 1, in which the control unit 22 calculates the track to be reproduced from the address signal of the reproduction command signal, and further calculates the calculated reproduction track and the recording/reproduction prohibited track, that is, the 100th track. A pulse corresponding to the track difference is outputted from the control section 22 and applied to the step motor. In this way, the magnetic head moves to the commanded reproduction track, reproduces that track several times in order to improve the reliability of the reproduction data, and then sends the reproduced data to the calculation unit 11 of the data processing device 1 via the recording and reproduction unit 24. . The procedure for returning the magnetic head to the recording/reproduction inhibited track after the end of reproduction is the same as that after the end of recording, so a description thereof will be omitted.

In the above embodiment, a processing device such as a CPU provided in the tape recorder stores the operating state of the tape recorder mechanism, stores the program, and calculates the control signal based on the command signal from the data processing device. , data processing unit CPU
Of course, you can also do it with Also,
The recording/reproduction prohibited track is not limited to one track, but may be a plurality of tracks, and the position thereof is preferably at the center in the width direction of the tape, but may not be at the center.

As explained above, in the present invention, in a tape recorder having a plurality of tracks in the width direction of the tape, a specific track of the magnetic tape is set as a recording/playback prohibited track, and the magnetic head is prohibited except during recording or playback operations. Since it is positioned on the track, the recording signal is not unnecessarily demagnetized, and therefore reliable reproduction output of the digital signal can be obtained. Furthermore, by setting the recording/playback prohibited track at approximately the center of the width of the tape, it is possible to shorten the access time when reproducing recorded data and prevent the magnetic head from shifting. This has the advantage that the playback output becomes uniform.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing a tape recorder according to the present invention using functional blocks, FIG. 2 is a magnetic head drive mechanism of the tape recorder, and FIG. 3 is a flowchart of a recording mode. 1...Data processing device, 2...Tape recorder, 3
...Base, 4...Step motor, 5, 6, 7...Gear train, 8...Drive shaft, 9...Head mounting shaft, 10...Magnetic head, 11...Data calculation section, 12...Control section.

Claims (1)

[Scope of Claims] 1. In a tape recorder having a plurality of tracks in the width direction of the tape, a storage unit that stores track positions of a magnetic head, and a track position of the magnetic head stored in the storage unit in a recording mode or a playback mode. a calculation unit that calculates the difference between the magnetic head position and a predetermined recording/reproduction prohibited track position of the magnetic head; A tape recorder comprising a head drive means for moving the tape recorder. 2. The tape recorder according to claim 1, wherein the recording/reproduction inhibiting track position is located approximately at the widthwise center of the magnetic tape.