JPS6314408B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a head moving device suitable for use in a magnetic recording and reproducing device for recording and reproducing video signals.

A conceivable magnetic recording/reproducing device is a device capable of running an endless magnetic tape at high speed, supplying video signal information to a magnetic head disposed at a fixed position, recording on the magnetic tape, and reproducing the same. ing. As shown in FIG. 1, this device is of a type in which recording tracks T ₁ , T ₂ , _. . .
2 is controlled to move in the tape width direction when the magnetic tape 11 makes one revolution.

With this type of device, the recording track
It is necessary for the magnetic head 12 to trace T ₁ , T ₂ , . . . T _o at accurate intervals. In particular, magnetic head 1
The mechanism section for controlling the movement of tape 2 in the tape width direction requires highly precisely machined parts, but there are limits to manufacturing technology, and rattling is likely to occur.

The present invention has been made in order to cope with the above-mentioned circumstances, and an object of the present invention is to provide a head moving device having a simple structure, easy to manufacture, and capable of controlling the movement of the head with high precision.

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 2 shows the basic configuration of a magnetic recording and reproducing apparatus to which the present invention is applied.
is wound. A tape pull-out hole 21 is formed in the fixed reel 20, and the innermost peripheral portion of the magnetic tape 11 is pulled out from the tape pull-out hole 21. This pulled out portion is brought into contact with the head mechanism section 23 by guide poles 22a and 22b, and guided between the capstan 24 and the pinch roller 25. That is, the magnetic tape 11 is moved through the tape pull-out hole 2 by the rotation of the capstan 24.
1 and run opposite to the head mechanism section 23, in which video signals are recorded and reproduced. The magnetic tape sent out from 24 capstans is
The magnetic tape 11 is guided through curved guide plates 26a and 26b to the outermost circumference of the wound magnetic tape 11 and wound up. In this case, the wound magnetic tape 11 is rotated as a whole around the outer periphery of the fixed reel 20 as shown by the arrow as it is pulled out by the capstan section, so that the tape that is pulled out touches the edge of the winding section. It will be rolled over and wound around the outer periphery.

FIG. 3 shows the head mechanism section 23 taken out, and is equipped with a tape guide body 30. The tape guide body 30 includes a pair of guide plates 32a and 32 that regulate the surface of the magnetic tape 11 relative to the magnetic head 31.
b and a stepped portion 33 that regulates the edge of the tape.
Since the magnetic tape 11 is placed on the step 33 and runs along the surfaces of the guide plates 32a and 32b, the height position of the running magnetic tape 11 is regulated by the step 33. This also determines the position of the track formed by the magnetic head 31.

FIG. 4 shows tracking control means for the magnetic head 31. The magnetic head 31 is attached to a head base 35.
It is attached by adhesive or other means. The head base 35 includes a board 3 disposed horizontally.
It is attached to the tip of 6 by means of screws or the like. A rotation preventing member 37 for preventing rotation is attached to the substrate 36 in a direction perpendicular to the substrate. The rotation preventing member 37 is, for example, a cylindrical shaft,
It passes through a shaft hole 36 ₁ provided in the substrate 36 and is fixed to the substrate 36 by, for example, a screw 38 . Therefore, when the substrate 36 is driven up and down in the direction of arrow Z in the figure, the rotation stopper 37 also moves up and down together.

Furthermore, a hole-shaped portion 36 ₂ is provided at the rear end of the substrate 36 .
is formed, and a male screw 39 is rotatably inserted through this. This male screw 39 is used for vertically driving the substrate 36 and the like, and is arranged parallel to the rotation preventing member 37. This male screw 3
9 is rotatably but immovably supported by bearing portions 41 and 42 of opposing bearing portions of the housing 40 . In this case, the male screw 39 is attached to one of the bearing parts 4 so as to prevent rattling in the vertical direction.
1 is pressed in the other direction by a washer 43 having elasticity. Further, the rotation preventing member 37 is also supported by bearing portions 44 and 45 of the housing 40. In this case, the bearings 44 and 45 are provided with slippery rings 4 so as to smoothly move the rotation preventing member 37.
4 ₁ and 45 ₁ are provided. Note that this may be formed by the housing 40 itself that constitutes the bearing parts 44 and 45.

Next, the base plate 36 and the male thread 39 are associated with each other by a female thread means having a single-blade structure inclined in accordance with the thread inclination. That is, as shown in FIG.
are pressed against each other, and the pressing member 47 is brought into contact with the other one.
As a result, the male screw 39 is connected to the blade-shaped engagement member 46.
It is in the shape of being held between the holding members 47. The engaging member 46 is fixed to the substrate 36 with screws 49 and 50, and the holding member 47 is attached to the substrate 36 with a screw 51 via the elastic body 48. In this case, the elastic body 48 connects the engaging member 46 to the external thread 39.
It acts to press against the

The housing 40 is a chassis 5 of the main body of the device.
It is fixed at 2. In this case, a gear 53 is attached to the lower end of the male screw 39, and a gear 54 of a pulse motor 55 is meshed with the gear 53. In the head moving device described above, the male screw 39 is rotated by the rotation of the pulse motor 55, and the substrate 36, that is, the head 31, is controlled to move in the width direction of the magnetic tape 11 so as to come into contact with a track position.

According to the head moving device of the present invention constructed as described above, the blade-shaped engagement member 46 constitutes a part of the female screw with respect to the male screw 39. Further, a pressing member 47 is pressed against the engaging member 46 .
The tip of the blade of the engagement member 46 has an apex angle substantially equal to the apex angle of the male thread 46, and is inserted into the thread groove of the male thread.
Therefore, this engaging member 46 is connected to the male screw 39 in the axial direction of the board 36 (the Z direction in the drawing) or in the direction shown in the drawing.
Shake in the Qx direction can be controlled and eliminated.

Further, the substrate 36 is stably held horizontally by the rotation preventing member 37 as well. Further, the rotation preventing member 37 is supported vertically (in the Z direction) by the housing 40, and is also supported by a support portion (bearing portion).
Since they are spaced apart from each other, there is no rotation in the directions of arrows Qy and Qx shown in the figure, and therefore, the rotation preventing member 37 allows the substrate 36 to maintain its posture stably.

Further, since the holes in the bearing parts 44 and 45 of the housing can be machined simultaneously with the same tool, the coaxiality is good, and the bearing part 4 which receives the male thread 39 has good coaxiality.
The parallelism with holes 1 and 42 is also extremely accurate.
Furthermore, if the rotation preventing member 37 is cylindrical, the hole will also be a round hole, resulting in a simple shape, easy machining, and a highly accurate fitted state. Further, the tip (head) side of the substrate 36 is regulated by a holding member 47, so that there is no wobbling in the Y direction in the figure.

According to the above device, by using an engaging member in which at least the blade-like tip fits into the groove of the male screw as the female screw means, rattling of the male screw and the female screw can be prevented with a simple-shaped part that is easy to manufacture. It is possible to create a device that can eliminate the Furthermore, by simplifying the shape of the parts, it is possible to reduce the cost, ease of assembly, and reduce the number of man-hours. Furthermore, by simplifying the configuration and downsizing of the female thread means, the overall space (especially height) of the threaded portion can be small relative to the necessary movement stroke of the head, resulting in a smaller device as a whole, and a smaller housing. You will also get a price reduction.

The present invention is not limited to the above-described embodiments, and the same effects as in the previous embodiments can be obtained even with the following configuration.

FIG. 6 shows another embodiment of the female screw means, in which a bolt 61 is horizontally fixed to the base plate 36, and by turning a nut 62 screwed onto the bolt 61, a repulsion spring 63 is attached. Therefore, the pressing force of the presser member 47 can be adjusted. Figure b is a sectional view taken along line A←→A' in figure a.

FIG. 7 also shows another embodiment of the female screw means.
In this case, a torsion coil spring 6 is used as the holding member.
This is an example using 4. Figure b is B in figure a←→
It is a sectional view taken along the line B'.

Furthermore, FIGS. 8 and 9 show other examples of the female screw means. The female screw means shown in FIG. 8 has a locking portion 66 that locks one end of a compression spring 65 on the side of the base plate 36, and the other end of the compression spring 65 presses a presser member 67 against the male screw 39. It has been done. Also the 9th
The female screw means shown in the figure is an example in which a presser member 69 that is pressed against the outer periphery of the male screw 39 by an elastic body 70 is used.

Furthermore, various embodiments are possible as the engaging member, and it may have a plurality of blades. In this case, the engaging member 71 as shown in FIGS. 9 and 10 is used. becomes. In addition, as an engaging member,
As shown in FIG. 11, it may be an engaging member 73 in which a ball 72 is provided on a part of the blade. Further, in order to elastically press the holding member against the male screw, the fulcrum may be supported by a butterfly plate, or a tension spring may be used. Note that common parts in each of the above-mentioned figures are given the same reference numerals.

Figures 12a and 12b show a conventional head moving mechanism. In FIG. 12, 81 is a pulse motor, 82 is a chassis, 83 is a rotating mechanism, 84 is a housing, 85 is a male screw, 86 is a female screw, 87 is a head base, and 88 is a magnetic head. According to this mechanism, in vertically guiding the female screw 86 that moves up and down,
Directional deflection control is obtained on the thread surface of the male thread 85. Further, the rotation of the female thread 86 in the horizontal plane (restricted in the Qz direction shown in the figure) is achieved by guide surfaces 90a and 90b (shown in the figure b) that are part of the housing 84.

According to this device, the male screw 85 and the female screw 86 tend to fit loosely, and the position of the magnetic head 88 also fluctuates in the vertical and horizontal directions. In particular, in magnetic recording and reproducing devices, vertical positional fluctuations of the magnetic head 88 result in track deviation (approximately 35 μm in the vertical direction).
error (misplacement of recording signal bands lined up at the same pitch) or noise (noise due to fluctuations in the playback signal level due to the head being deviated from the center of the recording signal band)
occurs. In order to reduce the rattling of the fitting between the male thread 85 and the female thread 86 to within the target precision of microns, complicated processing such as thread alignment and pitting processing is required, which increases the cost and is not suitable for mass production. The female thread 86 needs to be long in the axial direction, which increases the size of the entire structure. There are problems such as. Furthermore, rotation of the female screw 86 in the horizontal plane is restricted by a guide surface 90 on a part of the housing 84.
a, 90b and partially protruding ends 86a, 8 of the female thread 86
6b, but in the vertical direction, the guide surface 9
The contact range between 0a, 90b and the protruding ends 86a, 86b is small and is only at one location in the vertical direction, so it is not shown in the figure.
Shakiness in the Qx direction is likely to occur.

The apparatus of the present invention does not have the above-mentioned problems, and the moving pitch of the magnetic head can be made extremely accurate and consistent.

As described above, the present invention eliminates rattling of the board by attaching a rotation preventing member vertically to the board and using a blade-like engagement member for the female screw means, and is easy to assemble and inexpensive. Therefore, it is possible to provide a head moving device that can be made small in size and that can control the movement of the bed with high precision.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing an example of a magnetic recording pattern of a magnetic recording and reproducing device to which the present invention is applied, FIG. 2 is a basic configuration diagram of the magnetic recording and reproducing device to which the present invention is applied, and FIG. FIG. 4 is a configuration explanatory diagram showing an embodiment of the present invention; FIG. 5 is a diagram showing the threaded portion of FIG. 4; FIGS. Figure 7 a, b, Figure 8, Figure 9
11 are views showing other embodiments of the female screw means applied to the present invention, and FIG. 10 is a view showing other examples of the engaging member applied to the present invention,
FIGS. 12a and 12b are diagrams showing a conventional head moving device and its rotation regulating means. 36... Board, 37... Rotating member, 39... Male thread, 40... Housing, 46... Engaging member, 47...
Pressing member, 48...elastic body.

Claims (1)

[Scope of Claims] 1. A substrate having a head attached to a horizontal end, a rotation preventing member attached perpendicularly to the substrate, and a hole-shaped portion of the substrate arranged parallel to the rotation preventing member. An engaging member fixed to the substrate such that at least one blade-like tip engages a vertically inserted male screw without going around the male screw once in accordance with the slope of the thread groove of the male screw, and this engagement. female screw means having a pressing member positioned to sandwich the male screw together with the member and applying a pressing force in the pinching direction by an elastic body latched to the substrate; 1. A head moving device comprising: a housing that supports the male screw so as to be movable in the axial direction and rotatably supports the male screw so as to be immovable in the axial direction. 2. The head moving device according to claim 1, wherein the engaging member has a single blade shape. 3. The head according to any one of claims 1 to 2, wherein the female thread means includes an adjustment means attached to the base plate so as to be able to adjust the pressing force of the elastic body. Mobile device. 4. The head moving device according to any one of items 1 to 3, wherein the rotation preventing member has a cylindrical shape.