JPH0214406A - magnetic recording and reproducing device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a magnetic recording/reproducing device which is particularly useful for use with video floppies.

Conventional technology A conventional example will be explained using drawings.

FIG. 3 is a block diagram showing a video floppy device for recording and reproducing still images on a magnetic sheet.

In FIG. 3, a magnetic head 2 is in contact with a magnetic sheet 1.
is translated in the radial direction of the magnetic sheet 1 by the movement of the carriage 6 that fixes the magnetic head 2 by the rotation of the rotating shaft 4 of the stepping motor 3. In addition, the magnetic head 2 is
In the head configuration, one side is connected to the erase signal generator 8 and the other side is connected to the recording/reproducing circuit via the changeover switch 6 and the connection switch. Therefore, during erasing, an erasing signal is supplied from the erasing signal generator 8 to the magnetic head 2.

FIG. 4 is a diagram showing the relative relationship between the recording tracks of the magnetic sheet 1 and the magnetic head, and the operation during erasing will be explained below.

The magnetic sheet 1 has recording tracks 12a and 12b.

12c is a track width of 60 μm, guard band (shaded area)
It is recorded at intervals of 40 μm. The magnetic head 2 has a two-track configuration and has the same shape as the recording track 12 in the track width direction. Therefore, by supplying an erase current to the head 2, the recording track 12 can be erased.

The recording track 12 is due to the dimensional error of the recording device, and the magnetic sheet 1
Errors may occur due to the temperature characteristics of the recording track 12.
By changing the position of the magnetic head 2 relative to the magnetic head 2, the occurrence of unerased portions is prevented.

Problem to be Solved by the Invention However, in the conventional device, displacing the magnetic head 2 in the track width direction of the recording track 12 means that erroneous erasing of adjacent tracks occurs, and for this reason, the amount of displacement is limited. As a result, unerased portions occur, which interferes with the recorded signal.

Means for Solving the Problems The magnetic recording apparatus of the present invention supplies an erasing current to a recording/reproducing head having a two-head configuration, and further controls and moves the magnetic head in the track width direction every 1/3 of the track pitch. The invention is characterized in that it includes a means for doing so.

According to the present invention, a two-head magnetic head is moved in the track width direction of the magnetic sheet at intervals of % of the track pitch of the recording tracks of the magnetic sheet by supplying an erase current to one of the magnetic heads. The magnetic head supplied with the erasing current is displaced by -Bn/n with respect to the center of the recording track width to erase a width wider than the recording track width, and
When erasing frame recording tracks, the value of m is changed between the inner circumferential direction and the outer circumferential direction of each recording track, thereby erasing everything between the frame tracks.

Embodiment FIGS. 1 and 2 show an embodiment of the magnetic recording/reproducing apparatus of the present invention. In FIG. 1, a magnetic head 2 that comes into contact with a magnetic sheet 1 is attached to a carriage 6 that moves by rotation of a rotating shaft 4 of a stepping motor 3, and moves in the radial direction of the magnetic sheet 1. Furthermore, the magnetic head 2 is
One head is connected to a video signal recording and reproducing system, and the other head is connected to a changeover switch 11.

The changeover switch 11 is similarly connected to the video signal recording/reproducing circuit and the erasing signal generator 8. The erase signal generator 8 supplies an erase current to one of the magnetic heads 2 using a changeover switch 11 during erasing.

Next, the operation of the magnetic head 2 during erasing will be explained using FIG.

FIG. 2 shows the relative position of the recording track 12 recorded on the magnetic sheet 1 and the magnetic head 2. As shown in FIG.

In the recording track 12 determined to be frame recording by the recording mode detector 10, one frame of video signal is recorded, and 12a represents the first field μ field and 12b represents the second field.

The magnetic head 2 rotates the recording track 12 (60μ) by rotating the stepping motor 3 corresponding to the 10 rotations of the magnetic sheet.
m) every 1/n (n=10 μm), and during erasing, it is displaced by 10 m/m and −1− (m is an integer integer) with respect to the center of the track width.

For example, to erase the recording track 12a, -)m=
1, -m=3, and +1 for each track width center
0μm, -30μm displacement. Similarly, recording track 1
To erase 2b, +30 μm from the center of the track width by setting 10 m = 3 and −m = 1.

-10 μm. Therefore, the frame recording tracks 12a and 12b are completely erased including the guard bands (shaded areas).

Effects of the Invention As described above, the magnetic recording/reproducing device of the present invention has no unerased portion even if an error occurs in the recording track position due to compatibility, temperature characteristics of the magnetic sheet, etc. A signal (so-called ID signal) is superimposed, which has the advantage of preventing erroneous discrimination due to non-erased data and enabling good recording and reproduction.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the magnetic recording/reproducing device of the present invention, FIG. 2 is an explanatory diagram of the erasing operation of the same device, FIG. 3 is a block diagram showing a conventional magnetic recording/reproducing device, and FIG. 4 is a diagram showing the relationship between the magnetic head and the magnetic sheet of the same device. 1...magnetic sheet, 2...magnetic head, 3...stepping motor, 4...
Rotating shaft, 5... Carriage, 8... Erasing signal generator, 1o... Recording mode detector. Name of agent: Patent attorney Shigetaka Awano and 1 other person Figure 12α-～-Araki I field. 12b-+ z fee sit? ! 2θ

Claims (1)

[Claims] It has a field recording mode in which one field of video signal is recorded on each concentric track of a magnetic sheet, and a frame mode in which one frame of video signal is recorded in two tracks, and is erased using a recording/reproducing head. The magnetic recording/reproducing device moves the head in the track width direction every 1/3 of the track pitch, and when erasing a field recording track, moves the head by the same amount in both the inner and outer circumferential directions of the recording track. The head position control means is provided for erasing a frame recording track in a wider width than the recording track, and for making the amount of head movement from the center of each of the two recording tracks different in the inner circumferential direction and the outer circumferential direction when erasing the frame recording track. Features of magnetic recording and reproducing device.