JPH0263247B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a magnetic head reversing device used in an auto-reversing tape recorder.

2. Description of the Related Art Auto-reverse tape recorders are already well known, which automatically switch the running direction of a magnetic tape so that recording or playback can be performed even when the magnetic tape runs in either the left or right direction. This type of tape recorder is equipped with a pair of magnetic heads and uses both heads selectively depending on the running direction of the magnetic tape. There is a method in which the position of the core gap is changed in the tape width direction by moving the magnetic head. moreover,
There are two ways to move a single magnetic head: one is to move the magnetic head up and down, and the other is to rotate it 180 degrees to change the height of the core gap.

The present invention relates to an improvement of a magnetic head reversing device in an auto-reverse type tape recorder in which each magnetic head is rotated 180 degrees at a time.

Generally, this type of magnetic head reversing device has a configuration in which a rotating plate with a magnetic head attached thereto is rotatably attached to the head board, and the rotating plate is rotated 180 degrees by a drive mechanism to invert the magnetic head. It is becoming.

By the way, this type of conventional device has a structure in which a support shaft fixed perpendicularly to the center of the rotating plate is inserted through a through hole provided in the head board, and in order to prevent the magnetic head from wobbling, It was necessary to minimize the dimensional difference between the outer diameter of the support shaft and the inner diameter of the through hole, and to make the length of the bearing portion that supports the support shaft, that is, the through hole, sufficiently long. Therefore, manufacturing becomes difficult because the dimensional accuracy of the support shaft and the through hole must be high, and the length of the support shaft and the through hole must be increased, making the head board thicker and the overall size larger. There were flaws.

The present invention has been made based on the above circumstances, and its object is to provide a small magnetic head reversing device that can prevent the wobbling of the magnetic head, is easy to manufacture, and is easy to manufacture.

In order to achieve this object, the magnetic head reversing device of the present invention inserts a support shaft fixed to a rotating plate into a through hole provided in a head substrate, and fixes a driven member to the shaft end of the support shaft. A spring receiving plate is disposed between the driven member and the head board, and three or more recesses are formed at equal angular intervals on the front and back surfaces of the head board, respectively, with the support shaft as the center. Spheres are accommodated in the recess to form gaps between the rotating plate and the head board and between the spring receiving plate and the head board, and also to form gaps between the spring receiving plate and the driven member. By inserting a compression spring between them, the rotary plate is biased toward the head board.

Hereinafter, a detailed explanation will be given based on examples.

In the figure, 1A is a recording/playback magnetic head, 1
B is the erase head, 2 is these heads 1A, 1B
3 is a rotary plate to which the head support 2 is attached, and 5 is a head substrate. The core gap 6 of the recording/playback magnetic head 1A is located away from the center O of the rotating plate 3, and the dimension between the center O of the rotating plate 3 and the core gap 6 is the same as the channel center distance of a two-channel magnetic tape. It is set to 1/2 of the distance.

The heads 1A, 1B are attached to one surface of the rotary plate 3, and a hollow support shaft 7 is vertically fixed to the center of the other surface of the rotary plate 3.
Lead wires 8 connect between the magnetic head 1A and erase head 1B and a control circuit (not shown).
is inserted through the inside of this support shaft 7. On the other hand, the head substrate 5 is provided with a through hole 9,
The support shaft 7 is inserted through the through hole 9. In addition,
A tape guide 10 is integrally formed on the head support 2.

Three recesses 11 . . . , 12 . Hard spheres (for example, steel balls) 13..., 14 are placed in these recesses.
...is accommodated.

In addition, a pair of locking pieces 15 are provided on one side of the rotating plate 3.
A and 15B are bent. On one side of the head board 5 are screw mounting pieces 16A and 16B.
are provided, and each screw mounting piece 16A, 16B has an azimuth screw 1 corresponding to each locking piece 15A, 15B.
7A and 17B are screwed together. Furthermore, each screw mounting piece 16A, 16B and each azimuth screw 17A, 1
Compression coil springs 18A, 1 are connected between the head of 7B and
8B is inserted in a compressed state to stabilize the position of each azimuth screw 17A, 17B.

A gear 19, which functions as a driven member, is fixed to the front end of the support shaft 7 on the back side of the head board 5. Further, a spring receiving plate 2 having a through hole 20 is provided between the gear 19 and the head board 5.
1 is disposed with the support shaft 7 inserted through the through hole 20 thereof. And this spring receiving plate 21 and gear 1
9, there is a compression spring, for example, a compression coil spring 2.
2 is inserted in a somewhat compressed state. A slide plate 24, which constitutes a part of the drive mechanism 23, is attached to the back side of the head board 5 so as to be slidable in the left and right directions. As shown in FIGS. 3 and 4, this slide plate 24 has a rectangular opening 25.
A rack 26 is provided at the upper edge of the opening 25, and this rack 26 is meshed with the gear 19. Further, the lower end of the slide plate 24 is folded forward, and the folded portion 27 extends forward at a position below the heads 1A, 1B. A guide groove 28 that is long in the front-rear direction is formed in this folded portion 27 as shown in FIG. Further, a spring 29 is suspended between the slide plate 24 and the head board 5, and this spring 29 always applies a biasing force to the slide plate 24 toward the neutral position.

The head board 5 is provided on a tape recorder main body board (not shown) so that it can move forward and backward with the magnetic head 1A facing forward.

FIG. 5 shows the relationship between the slide plate 24 and pinch rollers 30A, 30B, etc. incorporated in the tape recorder main body board (not shown). The capstans 31A and 31B are arranged symmetrically to each other and are opposed to the capstans 31A and 31B, respectively. These pinch rollers 30A and 30B are provided with pinch roller supports 33A and 33A, which are rotatable about shafts 32A and 32B.
33B, and as the supports 33A and 33B rotate, the corresponding capstans 31A and 3
It is configured to move toward and away from 1B.

A drive gear 3 is attached to the one capstan 31A.
2 are coaxially and integrally attached, and the drive gear 32 and capstan 31A are always driven clockwise in FIG. 5 by a motor (not shown). The other capstan 31B is always driven counterclockwise in FIG. 5 by the above-mentioned common motor.

A large gear 33 is arranged near the one capstan 31A. This large gear 33 constitutes the drive mechanism 23 together with the drive gear 32, the slide plate 24, and the motor (not shown), and has two symmetrical non-engaging parts 34A with some teeth missing, 34B, and the upper surface has an eccentric pin 35 near the center and a pair of engagement pins 36A and 36B at symmetrical positions near the outer periphery. The eccentric pin 35 is inserted into the guide groove 28 of the slide plate 24.

In addition, 37 in FIG. 5 is an electromagnetic plunger, and a rotary lever 39 is attached to the movable part 38 of this plunger 37.
one end of which is engaged. A stopper pin 40 is provided at the other end of the rotary lever 39, and this stopper pin 40 is engaged with one engagement pin 36A.

Linear springs 41A, 41B are attached to each of the pinch roller supports 33A, 33B.

Next, the operation will be explained.

FIG. 5 shows the tape recorder in a stopped state, where the head board 5 and the magnetic head 1A are in the retracted position. Furthermore, the slide plate 24 is in a position moved to the left. Therefore, a restoring force is applied to the slide plate 24 in the rightward direction by the spring 29, and therefore the large gear 33 is biased counterclockwise in the figure. The stopper pin 40 engages with one engagement pin 36A, and rotation of the large gear 33 is prohibited. At this time, one non-engaging portion 34A faces the drive gear 32,
Therefore, the rotation of the drive gear 32 is not transmitted to the large gear 33.

For example, when a playback operation is performed from the state shown in FIG. 5, the head board 5 moves forward and the magnetic head 1A comes into contact with the magnetic tape. At this time, the left end of the slide plate 24 supports the left pinch roller. The linear spring 41A of the body 33A is pushed.
Therefore, as the magnetic head 1A moves forward, the pinch roller support 33A rotates, and the left pinch roller 30A is pressed against the corresponding capstan 31A as shown by the imaginary line in the figure. At this time, the pressing force of the pinch roller 30A against the capstan 31A is given by the elasticity of the linear spring 41A. Therefore, the magnetic tape is capstan 3.
1A and pinch roller 30A, and travels to the left in the figure by rotation of capstan 31A to perform a predetermined regeneration operation.

When the magnetic tape is pulled out to the end in this manner, a tape running direction switching signal is issued from a tape position detecting device (not shown), thereby driving the head board 5 together with the slide plate 24 in the backward direction. At the same time, the electromagnetic plunger 37 is energized for a short time. As the slide plate 24 retreats, the left pinch roller 30A separates from the left capstan 31A. Furthermore, when the electromagnetic plunger 37 is energized, the rotation lever 39 rotates, and the stopper pin 40 is disengaged from the engagement pin 36A.
The large gear 33 is slightly rotated counterclockwise in FIG. 5 by the spring 29. Therefore, this large gear 33 will mesh with the drive gear 32, and the drive gear 33 will mesh with the drive gear 32.
When the other non-engaging portion 34B faces the drive gear 32 after rotating 180°, the other engaging pin 36B engages the stopper pin 40.
, and the large gear 33 stops again. and,
While the large gear 33 rotates 180 degrees, the slide plate 24
is moved from the left position shown in FIGS. 3 and 5 to the right position shown in FIG. 4 due to the engagement between the guide groove 28 and the eccentric pin 35. At this time, the gear 19 rotates 180 degrees due to the movement of the rack 26, and the magnetic head 1A and erasing head 1B rotate 180 degrees together with this. At this time, since the elastic force of the spring 29 is acting to the left on the slide plate 24, the large gear 33 is urged counterclockwise in FIG. 5.

In this state, the head board 5 is driven forward again to bring the magnetic head 1A into contact with the magnetic tape, but as the head board 5 moves forward, the right end of the slide plate 24 is now pinched to the right. This pushes the linear spring 41B of the roller support 33B. Therefore, as the magnetic head 1A moves forward, the right pinch roller 30B is moved to the right capstan 3.
It comes to be pressed into contact with 1B. Therefore, the magnetic tape is connected to the right capstan 31B and the pinch roller 3.
0B, and travels to the right in FIG. 5 due to the rotation of the capstan 31B, and then a predetermined regeneration operation is performed.

Note that switching from the rightward running state of the magnetic tape to the leftward running state is performed in the same manner.

In the magnetic head reversing device configured as described above, the rotary plate 3 is pressed against the head substrate 5 via the three steel balls 13 due to the elasticity of the compression coil spring 22, so that the support shaft 7 and the through hole 9 Even if there is a gap between the rotating plate 3 and the through hole 9, the rotary plate 3 is always stably held. Therefore, the magnetic head 1A attached to the rotating plate 3 will not wobble. Therefore, a high degree of dimensional accuracy is not required when processing the through hole 9 of the head substrate 5 and the support shaft 7, and manufacturing becomes easy. Further, steel balls 14 are also provided between the back surface of the head board 5 and the spring receiving plate 21.
Since the compression coil spring 22 is interposed therebetween, no torsional force is applied to the compression coil spring 22, and the rotating operation of the rotary plate 3 is performed smoothly. Furthermore, since the head board 5 is provided with recesses 11..., 12... on the front and back surfaces to accommodate the steel balls 13..., 14... Each gap between the receiving plate 21 and the receiving plate 21 can be made smaller, and together with making the head substrate 5 thinner, the overall size can be reduced.
Further, the slide plate 24 that rotates the gear 19 as a driven member includes a pinch roller support 33A,
Since it is also used as a pressing member for selectively pressing 33B, the configuration of the auto-reverse device is simplified. A rectangular opening 25 is provided in the slide plate 24, and the gear 1 is provided at the upper edge of the opening 25.
9 is provided, so that the gear 19 is located inside the opening 25.
Therefore, there is no problem in which the lead wire 8 inserted through the support shaft 7 to which the gear 19 is fixed is caught between the gear 19 and the rack 26.

Note that the present invention is not limited to the configuration of the above embodiment. For example, the number of recesses 11..., 12... provided on the front and back surfaces of the head substrate may be four or more. Of course, in this case as well, hard spheres such as steel balls are to be accommodated in all the recesses. Further, the driven member is not limited to a gear, and any drive mechanism may be used as long as the driven member is reversed by 180 degrees.

As detailed above, in the magnetic head reversing device of the present invention, the support shaft fixed to the rotating plate is inserted into the through hole provided in the head board, and the driven member is fixed to the shaft end of the support shaft. A spring receiving plate is disposed between the driven member and the head board, and three or more recesses are formed at equal angular intervals on the front and back surfaces of the head board, respectively, with the support shaft as the center, and A sphere is accommodated in each recess so that the spheres form gaps between the rotating plate and the head board, and between the spring receiving plate and the head board, and also between the spring receiving plate and the driven member. By inserting a compression spring between them, the rotating plate is biased toward the head substrate.

Therefore, it is possible to prevent the magnetic head from wobbling, to facilitate manufacturing, and to achieve the desired effects, such as miniaturization.

[Brief explanation of drawings]

The drawings show one embodiment of the present invention; FIG. 1 is a front view, FIG. 2 is a sectional view taken from FIG. 1, FIGS. 3 and 4 are rear views in different operating states, and FIG. FIG. 2 is a plan view showing the relationship between a slide plate, a pinch roller, and the like. 1A...Magnetic head for recording/playback, 5...Head board, 7...Support shaft, 9...Through hole, 11, 12
...Concavity, 13, 14...Steel ball (sphere), 19...
... Gear (driven member), 21 ... Spring receiving plate, 2
2... Compression spring, 23... Drive mechanism.

Claims (1)

[Claims] 1 A rotating plate with a magnetic head attached to one side,
A support shaft fixed perpendicularly to the center of the other surface of the rotary plate, a head board having a through hole through which the support shaft is inserted, and a support shaft attached to the front and back surfaces of the head board. three or more recesses formed at equal angular intervals around the center, a driven member fixed to the shaft end of the support shaft, and a through hole in the center, into which the support shaft is inserted. A spring receiving plate is inserted through and disposed between the head board and the driven member, and a spring receiving plate is housed in each of the recesses and is housed between the rotary plate and the head board and between the spring receiving plate and the head board. a plurality of spheres each forming a gap and reducing resistance to the rotational movement of the rotary plate; and a compressor inserted between the spring receiving plate and the driven member to bias the rotary plate toward the head board. 1. A magnetic head reversing device comprising: a spring; and a drive mechanism that rotates the driven member by 180 degrees to reverse the magnetic head.