JPH0734251B2 - Recording or playback device - Google Patents

Description

The present invention relates to an apparatus for winding a recording medium on the outer peripheral surface of a rotary cylinder having a rotary head and recording or reproducing a signal on the medium. .

[Conventional technology]

FIG. 6 is a diagram showing a configuration example of a main part of a rotary head assembly of a conventional magnetic recording / reproducing apparatus of this type, wherein 1 is a magnetic tape,
Reference numeral 2 is a rotary head, 3 is a fixed cylinder, and 4 is a rotary cylinder.

In FIG. 6, a tape guide groove is formed in the fixed cylinder 3. Then, by fixing the amount of protrusion of the rotary head 2 from the rotary cylinder 4 and the fixed cylinder 3 to several tens of μm, the magnetic tape 1 and the rotary head 2 wound around the rotary head assembly at a predetermined angle come into contact with each other. Always keeps.

[Problems to be solved by the invention]

When the running of the magnetic tape is stopped in the apparatus using the rotary head assembly as described above, the rotary head repeatedly traces the same portion of the magnetic tape. However, there was a drawback that the trace part of was damaged. Due to this drawback, the current VTR (video tape recorder) has a risk of damaging the magnetic tape in a recording standby state (hereinafter referred to as a pause state). Therefore, for example, it is common to have a safety device that automatically releases the pause state in about 5 minutes. However, in this case, it is impossible to hold the pause state for a long time of 7 minutes or more by a single operation, and the head moves over the tape even after 5 minutes (60 × 60 × 5 =) 18,000 times. Tracing is still the same, and there is no fundamental solution.

The present invention has been made to solve the above conventional problems, and an object of the present invention is to provide a recording or reproducing apparatus capable of preventing unnecessary wear of a rotary head and damage of a recording medium. And

[Means for solving problems]

The present invention has been made to solve the above-mentioned problems, and in a recording or reproducing apparatus, a recording medium is wound around the outer peripheral surface of a rotating cylinder provided with a head, and the recording medium is inserted through the head. In a recording or reproducing device for recording or reproducing a signal, a first substrate fixed to the rotary cylinder, and a second substrate to which the head is attached and which is movable with respect to the first substrate. A shape memory alloy provided between the first substrate and the second substrate; a spring stretched between the first substrate and the second substrate; A rod-shaped support member fixed to one of the substrate and the second substrate in parallel with the moving direction of the second substrate, and a hole provided in the other substrate and into which the rod-shaped support member is fitted. And the second substrate is
Due to the shape change of the shape memory alloy and the urging force of the spring, the first position where the head and the recording medium come into contact with each other, and the head and the recording medium come into contact with each other by retracting toward the rotation center direction of the rotary cylinder. It is characterized in that it is configured to move to a second position that does not.

[Action]

In the above-described configuration, when the rotary cylinder around which the recording medium is wound is rotating and in a recording standby state, the protrusion of the rotary head from the rotary cylinder is prohibited and the recording medium and the rotary head are not brought into contact with each other. I am trying.

〔Example〕

1 (a) and 1 (b) are diagrams showing the structure of a rotary head assembly in a recording / reproducing apparatus according to an embodiment of the present invention, and FIG. 2 is a block diagram showing a schematic configuration of the entire apparatus of this embodiment. Is.

1 and 2, 1 is a magnetic tape, 2a, 2b, 2
a 'and 2b' are head substrates forming a one-piece structure with the piezo elements 5 and 5'used as one of the objects whose shape can be changed, and 3 has a magnetic tape guide groove to hold the magnetic tape 1 at a predetermined angle. Fixed cylinder for winding only, 4 is piezo element 5, 5 '
Is a rotary cylinder in which a pair of head substrates are fixed.

3 (a) and 3 (b) are diagrams showing the head substrate in FIG. 1 in detail. The piezo element 5 is provided with lead wires 6a and 6b, and by applying a predetermined voltage or current to the lead wires 6a and 6b by a piezo drive circuit 13 described later, the direction of the arrow in FIG. It can be expanded and contracted. FIG. 3B shows that the piezo element 5 is sandwiched between the head substrates 2a and 2b, and an integrated structure is formed by a method such as adhesion or welding.
Is.

In the recording / reproducing apparatus configured as described above, recording,
When the magnetic tape 1 and the rotary heads HA and HB have to be in contact with each other as in the reproducing state, the capstan drive circuit 14 appropriately sets the capstan 16 based on the data D corresponding to the manual operation of the operation unit 15. The magnetic tape is rotated and the recording / reproducing signal processing circuit 10 performs desired signal processing, and the piezo drive circuit 13 is used to drive the piezo element 5 to a predetermined position as shown in FIG. 1 (a). By applying voltage or current, the piezo element 5 is extended, the rotary heads HA and HB are projected from the rotary cylinder 4 by several tens of μm, and brought into contact with the magnetic tape 1.

When the magnetic tape 1 and the rotating cylinder 2a do not have to come into contact with each other as in the paused state described above, the capstan drive circuit 14 and the recording / reproducing signal processing circuit 10 are appropriately controlled by the data D and the piezo drive circuit. The voltage or current applied to the piezo element 5 by controlling 13 is changed to contract the piezo element 5 and eliminate the contact with the magnetic tape 1. In addition, 11 is an input terminal of a signal to be recorded,
Reference numeral 12 is a reproduction signal output terminal, and 17 is a pinch roller.

In the embodiment shown in FIG. 3, the piezo element 5 is used as an example of an object whose shape is variable in order to change the protrusion amount of the rotary heads HA and HB. An example using a memory alloy is shown in FIG. Fourth
The shape memory alloy 7 shown in the figure is a flat plate as shown in FIG. 4 (a), but when a constant current is passed through the lead wires 8a and 8b, heat is generated due to the electric resistance effect of the shape memory alloy 7 itself. Then, it changes as shown in FIG. FIG. 5 shows the shape memory alloy 7 inserted between the head substrates 2a and 2b to form an integrated structure.

In FIG. 5, one head substrate 2a has two holes 21a,
21b are provided, and two rods 20a, 20b fixed to the other head substrate 2b are fitted into the holes 21a, 21b.
Shape memory alloy 7 is placed between a and 2b, and both head substrates 2a and 2b
By mounting the springs 29a, 29b on the spring mounting rods 22a, 22b and 23a, 23b respectively provided on the two head substrates 2a, 2b.
Are joined together.

By fixing the head substrate 2b to the rotary cylinder 4 in the above structure, the head substrate 2a can move in the direction indicated by the arrow in FIG. The rotary head 2a remains at a fixed position unless the shape memory alloy 7 changes.

By using the above structure, the shape memory alloy 7 is not energized during recording, reproduction, etc.
The HA is projected from the outer circumference of the rotary cylinder 4 to bring the magnetic tape 1 into contact with the rotary head HA. Further, in the standby state and the paused state, the shape memory alloy 7 is energized so that the rotary head HA is retracted from the rotary cylinder 4 so as not to come into contact with the magnetic tape 1.

〔The invention's effect〕

As described above, in the recording and reproducing apparatus, the recording medium is wound around the outer peripheral surface of the rotating cylinder provided with the head, and the recording or reproducing apparatus which records or reproduces the signal on the recording medium through the head is rotated. A first substrate fixed to the cylinder, a second substrate to which a head is attached and configured to be movable with respect to the first substrate, and provided between the first substrate and the second substrate A shape memory alloy, a spring stretched between the first substrate and the second substrate, and fixed to one of the first substrate and the second substrate in parallel with the moving direction of the second substrate. And a hole provided on the other substrate into which the rod-shaped support member is fitted, the second substrate is formed by the shape change of the shape memory alloy and the biasing force of the spring.
Since the head is moved to the first position where the head and the recording medium come into contact with each other and the second position where the head retracted in the direction of the rotation center of the rotary cylinder does not come into contact with the recording medium, the head is moved in a short time. It was possible to move the second substrate attached to the recording medium, prevent unnecessary contact between the head and the recording medium, and minimize damage to the recording medium and wear of the head. Further, in order to determine the position of the second substrate with respect to the recording medium into two positions, a first position where the head and the recording medium come into contact with each other and a second position where the head does not come into contact with the recording medium, Even when the recording medium comes into contact with the recording medium, it is possible to prevent the generation of noise and the loss of the signal, and it is possible to write or read the signal very stably.

[Brief description of drawings]

1 is a sectional view showing the structure of a rotary head assembly in a recording or reproducing apparatus according to an embodiment of the present invention, FIG. 2 is a block diagram showing a schematic structure of the entire apparatus in FIG. 1, and FIG. a) and (b) are diagrams showing the rotary head substrate portion in detail in FIG. 1, FIG. 4 is an explanatory diagram of a shape memory alloy,
FIG. 5 is a view showing a rotary head substrate portion including the shape memory alloy of FIG. 4, and FIG. 6 is a sectional view showing a structure of a conventional rotary head assembly. In the figure, HA and HB are rotary heads, 1 is magnetic tape, and 2a and 2b.
Is a rotary head substrate, 3 is a fixed cylinder, 4 is a rotary cylinder, 5 is a piezo element, 10 is a recording / reproducing signal processing circuit, 13 is a piezo drive circuit, 14 is a capstan drive circuit, and 15 is an operating unit.

Claims (1)

[Claims] 1. A recording or reproducing apparatus in which a recording medium is wound around an outer peripheral surface of a rotary cylinder having a head, and a signal is recorded on or reproduced from the recording medium via the head, the recording or reproducing apparatus being fixed to the rotary cylinder. A first substrate; a second substrate to which the head is attached and which is movable with respect to the first substrate; and a first substrate provided between the first substrate and the second substrate. A shape memory alloy, a spring stretched between the first substrate and the second substrate, and movement of the second substrate to one of the first substrate and the second substrate. A rod-shaped support member fixed parallel to the direction, and a hole portion provided on the other substrate into which the rod-shaped support member is fitted, the second substrate includes a shape change of the shape memory alloy and the spring. The head is brought into contact with the recording medium by the urging force of A recording or reproducing apparatus configured to move to a first position to be touched and a second position to be retracted in the direction of the rotation center of the rotary cylinder and the head and the recording medium are not in contact with each other. .