JPS62128072A - Head feeding device - Google Patents

Abstract

PURPOSE:To eliminate the necessity of a motor as a driving source by making the reciprocating motion of an electromagnetic movable coil into a driving source, and after the reciprocating motion is converted into a rotating motion, shifting a head with the converting mechanism converted to a linear motion. CONSTITUTION:By supplying an electric current pulse to a movable coil 23, the coil 23 is reciprocated and works as the driving source of a head feeding. A ratchet gear 29 and a feeding claw 31 constitute the first converting mechanism to convert the reciprocating of the movable coil 23 into the rotating motion. A rack gear 38 formed at the tip of a scanning arm 39 is geared with a small diameter gear 37 to rotate in a single body with an interlocking gear 36, and the second converting mechanism to convert the rotation of the small diameter gear 37 into the linear motion is formed.

Description

Detailed Description of the Invention "Field of Industrial Application" The present invention is applicable to disk memory devices that magnetically or optically record and reproduce image information, audio information, and various other numerical information. This invention relates to a head feeding device.

``Prior Art'' A recording/reproducing device that records information on a magnetic disk or optical disk and reproduces the information scans in the radial direction of the disk with a recording or reproducing head that faces the disk in close proximity to the disk that rotates at high speed. The structure is as follows. In such recording and reproducing devices, the relative position of the head with respect to the disk is performed with an accuracy of micrometers, so the scanning of the head and the accuracy of its position are extremely important, so various device technologies related to head feeding have been developed. is being developed.

Fig. 4 shows an example of a magnetic feeder using a beam screw shaft, which is connected to the motor 1 by a coupling 2, and partially has bearings 4a and 4b with the screw shaft 3 as the base.
The enlarged diameter parts 3b and 3C provided on both sides of the threaded part 3a formed on the lead screw shaft 3 rotatably pass through the parallel arms 4a and 4b of the U-shaped sliding frame 4. A needle 6 provided on a presser plate 5 fixed to the arm ends of the parallel arms 4a, 4b is in contact with the threaded portion 3a.

A scanning arm 4C is integrally formed on the sliding frame 4,
A magnetic head 7 is provided on a part of this arm 4a.

In the magnetic head feeding device, a lead screw shaft 3 is rotated by a motor 1 to move a sliding frame 4, and a magnetic head 7 is moved in the radial direction of a magnetic disk that is rotated at high speed by a disk drive motor 8.

Figure 5 shows a magnetic head feeding device using a ratchet.This was developed as a magnetic recording and reproducing device for electronic still cameras.The tracking par 9 is fed in conjunction with an interlocking lever that flips up the quick return mirror. As a result, the ratchet gear 10 is advanced by one tooth by the feed pawl 11.

The ratchet gear 10 is provided with a steel belt drum 10a, and the stage 13 is moved via the steel belt 12 by rotation of the drum 10a. Than this,
The stage 13 moves along the guide shaft 14, and the magnetic head 15 provided thereon moves in the radial direction of the magnetic disk. In addition, in this conventional example, the ratchet gear 1
A locking pawl 16 for preventing reverse rotation is provided, and the interlocking lever for releasing the reverse rotation as appropriate and flipping up the mirror is configured to be charged by the driving force of the motor.

"Problems to be Solved by the Invention" As mentioned above, in disc-type recording and reproducing devices,
Since the scanning accuracy and positional accuracy of the recording or reproducing head are important, the configuration of the head feeding device is complicated and tends to be large in order to achieve that accuracy.In addition, as shown in the conventional example above, Most of them use a pulse motor or servo motor as the drive source for the head.

For this reason, in small devices such as electronic cameras, the installation space becomes a problem, and the cost of the device is high (resulting in many difficulties in realizing the equipment).

"Means for Solving Problems" In view of the above-mentioned circumstances, the present invention can be expected to have high accuracy.
Another purpose is to develop a head feeding device that is as compact and cost-effective as possible.

Therefore, in the present invention, as a first invention, there is provided a reciprocating drive source including an electromagnetic movable coil that fluctuates against a returning force by being supplied with electricity, and a reciprocating drive source that is interlocked by the forward movement or rhythm of the drive source. a first conversion mechanism that converts the
The present invention proposes a head feeding device that includes a second conversion mechanism that receives the rotational motion, converts the rotational motion into linear motion, and moves the head linearly along the surface of the recording medium disk.

Further, as a second invention, there is provided a reciprocating drive source including an electromagnetic movable coil that fluctuates against a returning force by being supplied with electricity, a ratchet gear that is stepped by a feed pawl that receives fluctuations of the electromagnetic movable coil, and this ratchet. a first conversion mechanism that includes a locking pawl that prevents the gear from reversing and converts the reciprocating motion of the electromagnetic movable coil into rotational motion; an interlocking gear that is interlocked by the ratchet gear to reduce the rotational momentum; and a tooth on the interlocking gear. The present invention proposes a head feeding device comprising a second converting mechanism, which is equipped with a rack gear that is combined with the rack gear, and linearly advances the head having a retreating force by the rack gear.

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

FIG. 1 is a perspective view showing a head feeding device according to the present invention, FIG. 2 is a plan view showing a main part of the feeding device, and FIG. 3 is a sectional view of a main part of the feeding device.

In these figures, 21 is a magnet made of a permanent magnet, and 22 is a yoke plate forming a magnetic path of the magnet. The magnet 21 and the yoke plate 22 are fixed to a part of the device so as to face each other at a predetermined distance.

Reference numeral 23 denotes a movable coil formed into a ring shape by integrally applying a large number of windings.This movable coil is fixed to the tip of a swinging lever 25 that swings about a support shaft 24 as a fulcrum, thereby connecting the magnet 21 and the yoke plate. 22 and can freely enter between the two.

As can be seen from FIG. 3, the swing lever 25 has its base rotatably supported on a support shaft 24, and is normally attached to a clamp provided between a pin 26 on the lever and the device fixing part. It receives a swinging force in the clockwise direction in FIG. 1 by the pressing force spring 27, and remains stationary at the swinging position where its side surface abuts against the stopper pin 28.

A current pulse is supplied to the moving coil 23.

When a current pulse is input, this coil 23 is deeply (attracted) into the magnetic field region between the magnet 21 and the yoke plate 22, and the swinging lever 25 resists the clamping force of the spring 27 and moves upward as shown in FIG. After the current pulse passes, the swinging lever 25 immediately returns to the state shown in FIG. 1 due to the clamping force of the spring 27.

Therefore, by supplying a current pulse to the movable coil 23, the coil 23 reciprocates and acts as a drive source for head feeding.

29 is a ratchet gear whose rotation axis is the support shaft 24;
This has a configuration in which the feed is fed in increments by a feed pawl 31 rotatably supported by a shaft pin 30 provided on the swing lever 25.

The feed pawl 31 is given a turning force in the counterclockwise direction in FIG.

On the other hand, a tapered cam is formed at the tail of the feed pawl 31, and in the swinging state shown in FIG. Since the feed pawl 31 is rotated slightly clockwise in FIG. 1, the tip pawl portion is separated from the ratchet gear 29.

The ratchet gear 29 and feed pawl 31 are connected to the movable coil 2
This constitutes a first conversion mechanism that converts the reciprocating motion of No. 3 into rotational motion.

Reference numeral 33 denotes a small diameter gear integrally connected to the ratchet gear 29 and pivotally supported on the support shaft 24, a large diameter interlocking gear 34 meshed with this, and a small diameter gear rotating integrally with this interlocking gear 34. A large-diameter interlocking gear 36 meshed with the ratchet gear 35 is used to appropriately reduce the rotational momentum of the ratchet gear 29.

38 is a rack gear formed at the tip of the scanning arm 39;
This is a small diameter gear 3 that rotates integrally with the interlocking gear 36.
7 to form a second conversion mechanism that converts the rotation of the small diameter gear 37 into linear motion.

The scanning arm 39 is integrally formed with a slider 40 that slides on a guide rod 41, and a recording head 42 is provided on this slider 40.

The slider 40 is guided by a guide rod 41 passing through it, and slides in the direction of the arrow shown while compressing a spring 43 when advancing the rad 42 towards the above, and by sliding in the direction of the arrow shown when moving the rad 42 backward. It slides in the opposite direction to the above in response to the expanding force of the spring 43.

The guide rod 41 has both ends 41a and 41b fixed to a part of the device, and one end 41a is provided with an elastic member 44 to weaken the impact force when the slider 40 retreats.

Reference numeral 45 denotes a locking pawl for preventing the ratchet gear 29 from reversing. Normally, it receives the turning force of the spring 46 and engages with the ratchet gear 29 to prevent reverse rotation, but the electromagnetic device 47
By supplying power at any time, the locking by the locking claw 45 can be released.

This release allows the slider 40 to return from the slid position and the recording head 42 to return to the initial scanning position.

48 is a motor that rotates the disk at high speed, and the disk is set on a turntable 49.

The recording head 42 described above moves in the radial direction of this disk.

Next, the operation of the head feeding device described above will be explained.

When the feeding device is stationary, the swing lever 25 is pulled by the spring 27 so that its side edge hits the stopper pin 28 and is in the state shown in FIG. As already mentioned, in this stationary state, the tip end pawl portion of the feed pawl 31 is slightly separated from the ratchet gear 29.

When a current pulse is supplied to the movable coil 23, the coil 23 is attracted towards the magnetic field area between the magnet 21 and the yoke plate 22 and moves in the direction of the arrow shown in the figure, thereby causing the swinging lever 25 to move as shown in FIG. It swings counterclockwise about the upper support shaft 24 as a fulcrum.

The feed pawl 31 pivots together with the swing lever 25 around the support shaft 24 in accordance with the above swing, and in the initial stage of swing of the swing lever 25, the tapered cam at its tail slides on the stopper pin 28, and then It goes beyond this. With this operation, the feed claw 31 is moved to the first position by the rotational force of the spring 32.
It rotates clockwise in the figure, and its tip end claw comes into contact with the teeth of the ratchet gear 29.

The feed pawl 31 follows the swinging lever 25 and pushes the ratchet gear 29 in the direction of the arrow shown in the figure as the swinging lever 25 swings.

Since the movable coil 23 loses its driving force after the current pulse has passed, the swinging lever 25 is pulled by the spring 27 and returns to the swinging position shown in FIG. 1, as described above.

The feed pawl 31 pivots clockwise in FIG. 1 around the support shaft 24 in accordance with the return swing of the swing lever 25. Therefore, at the final stage of return of the swing lever 25, a stopper pin is attached to the tapered cam surface. 28 hits, and the taper cam is pushed back in response to the subsequent return operation of the swing lever 25.

As a result, the feed pawl 31 rotates slightly clockwise in FIG.

The feed pawl 31 pushes the ratchet gear 29 by approximately one tooth by the above-described operation, and the rotational position of the ratchet/throat gear 29 thus pushed around is maintained by the locking pawl 45 preventing reverse rotation.

The above-described operation is repeated every time a current pulse is supplied to the movable coil 23, and the ratchet gear 29 is sequentially fed in increments.

The stepwise rotation of the ratchet gear 29 is performed by gears 33.34.3.
5, 36, and 37 to the rack gear 38, the momentum of the stepwise rotation is reduced by these gears, and the rack gear 38 converts the rotation into a linear motion.

As the rack gear 38 advances, the slider 40 compresses the spring 43 and moves in the direction of the arrow shown in the figure under the guidance of the guide rod 41, and the recording head 42 advances along the radial direction of the disk rotating at high speed, recording various information. will be carried out.

When the recording head 42 is advanced and power is supplied to the electromagnetic device 47 when the head 42 is in the final advanced position or the intermediate advanced position, the locking pawl 45 is activated by the excitation of the electromagnetic device 47.
is pulled back, and the rotation stop of the ratchet gear 29 is released. In this release, the ratchet gear 29 and each gear are free to rotate, so the slider 40
3, the recording head 42 moves all at once in the direction opposite to the illustrated arrow, and the recording head 42 returns to the initial scanning position.

In addition, in the above embodiment, the case where the recording head 42 for recording information on the magnetic disk is moved was explained.
To reproduce information recorded on this magnetic disk, the head may be moved in the same manner as described above, and the present invention can be similarly implemented on optical disks that are optically recorded and reproduced. Furthermore, the magnet 21 shown in the above embodiment may be configured as an electromagnet.

"Effects of the Invention" As described above, the head feeding device of the present invention uses the reciprocating motion of an electromagnetic moving coil as a drive source, and moves the head by a conversion mechanism that converts the reciprocating motion into rotational motion and then converts it into linear motion. This configuration eliminates the need for a motor as a drive source and has a simple configuration, which is suitable for downsizing the device and reducing production costs.Furthermore, by using the above-mentioned conversion mechanism as an interlocking gear configuration, it is possible to control the scanning of the head. Sufficiently high precision can be expected for the position control as well.

[Brief explanation of drawings]

FIG. 1 is a perspective view of a recording head feeding device showing an embodiment of the present invention, FIG. 2 is a plan view showing essential parts of the feeding device, FIG. 3 is a sectional view of essential parts of the feeding device, and FIG. FIG. 5 is a plan view of a conventional magnetic head feeding device using a lead screw shaft, and FIG. 5 is a simplified diagram of a conventional magnetic head feeding device using a ratchet gear. 21... Magnet 22... Yoke plate 23.
... Moving coil 24 ... Support shaft 25 ... Rocking lever 29 ... Ratchet gear 31 ... Feed pawl 33.34.37 ... Small diameter gear 34.36
... Interlocking gear 38 ... Rack gear 39 ... Scanning arm 40 ... Slider 41 ... Guide rod
42... Recording head 45... Locking claw
47...Electromagnetic device. Patent applicant: Kyocera Corporation Figure 3

Claims (2)

[Claims] (1) A reciprocating drive source equipped with an electromagnetic movable coil that fluctuates against a return force when supplied with electricity, and a first reciprocating drive source that is linked by the forward or backward movement of this drive source and converts the reciprocating motion into rotational motion. and a second conversion mechanism that receives the rotational motion, converts the rotational motion into linear motion, and moves the head linearly along the surface of the recording medium disk. (2) A reciprocating drive source equipped with an electromagnetic moving coil that moves against the returning force when supplied with electricity, a ratchet gear that is advanced by a feed pawl that receives fluctuations in the electromagnetic moving coil, and a reversal of the ratchet gear. a first conversion mechanism that includes a blocking pawl and converts the reciprocating motion of the electromagnetic movable coil into rotational motion; an interlocking gear that is interlocked by the ratchet gear to reduce rotational momentum; and a rack gear meshed with the interlocking gear. A head feeding device comprising a second converting mechanism that linearly advances a head having a backward force using the rack gear.