JPH0350354B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a magnetic recording device that records or reproduces information by spirally tracing a magnetic head on a rotating magnetic disk.

BACKGROUND TECHNOLOGY Conventionally, in this type of device, a magnetic disk is rotated by a single motor that rotates in one direction, and a movable body that holds a magnetic head is moved in the radial direction of the magnetic disk.

The specific driving means for the movable body is to first form a fan-shaped gear on the movable body whose rotational fulcrum is the center of the radius, and then to form a large number of drive gears each having teeth formed on a part of its outer periphery to mesh with this sector-shaped gear. It is connected to a motor via a reduction gear to bias the movable body in one direction.

Problems to be Solved by the Invention Therefore, the drive gear is always rotated in one direction to rotate the movable body in one direction, and when the teeth of the drive gear are disengaged from the sector gear, the movable body is Although the operation of returning to the other direction is repeated, the meshing positions of the teeth of the sector gear, drive gear, and reduction gear inevitably change each time the movable body makes one reciprocation. Even when looking at a single gear, it is extremely difficult to finish the large number of teeth arranged around the outer periphery to uniform dimensions. In particular, gears used in this field are often made of plastic to reduce costs, resulting in lower dimensional accuracy and dimensional changes due to temperature increases that cannot be ignored. Therefore, each time the movable body holding the magnetic head is reciprocated, the position of the magnetic disk relative to the track changes, resulting in the problem of so-called off-track.

In addition, a loop is formed in the middle part of one steel belt, this loop is wound around a pulley driven by a motor, and both ends of the steel belt are fixed to a movable object, and the pulley is rotated. There is a steel belt that moves back and forth, but since it forms a loop, the shape of the steel belt is complicated, and it is disadvantageous to remove material when punching the steel belt with a press.

This invention was made in view of the above points, and it is possible to reliably prevent the occurrence of off-track, easily connect the deceleration mechanism and the movable body with a simple steel belt, and furthermore, it is possible to easily connect the deceleration mechanism and the movable body with a simple steel belt. An object of the present invention is to provide a magnetic recording device that can accurately and easily determine a position.

Means for Solving the Problem As shown in FIG. 1, a drive shaft 5 that rotates the magnetic disk 16 and a movable body 8 that holds the magnetic head 7 and reciprocates in the radial direction of the magnetic disk 16 are provided. , a reduction mechanism 3 including a plurality of gears 24 to 30
The input side of 1 and the drive shaft 5 are connected to a motor 2 whose rotation direction is selectively controlled to either forward or reverse, biasing the movable body 8 in one direction, and one end of which is connected to the rotation output section of the speed reduction mechanism 31. A steel belt 3 is connected to the movable body 8 and is connected to the movable body 8 , has an intermediate portion folded back to a part of the movable body 8 , and has the other end fixed to the support portion 38 to pull the movable body 8 against the biasing force.
4 will be provided.

In addition, a support portion 36 that supports the steel belt 34 is provided.
is fixedly provided, and the steel belt 34 is attached to the support part 3.
6, and an adjustment screw 41 that presses and bends the leaf spring 39.
2 will be provided.

Function: Therefore, the motor 2 is rotated forward at a constant rotation angle, and the movable body 8 is rotated by the steel belt 34.
is pulled, the motor 2 is reversed, and the movable body 8 is returned to its original position by the biasing force, thereby causing the movable body 8 to reciprocate once. As a result, the meshing range of the gears 24 to 30 does not always change. Therefore, magnetic disk 1
Once the position of the movable body 8 with respect to 6 is adjusted,
No matter how many times the movable body 8 is reciprocated, the home position and operating range of the movable body 8 remain constant. The shape of the steel belt 34 can also be simplified. Furthermore, by folding back the steel belt 34,
The reduction ratio is increased to cause the movable body 8 to move slightly.

In addition, by turning the adjustment screw 41 to adjust the amount of bending of the leaf spring 39, the support portion 36 and the leaf spring 39 can be adjusted.
By changing the effective length of the steel belt 34 between the fixed end of the movable body 8 and the fixed end of the movable body 8, it is possible to accurately and easily adjust the home position of the movable body 8.

Embodiment An embodiment of the present invention will be described based on FIGS. 1 to 4. 1 is the base. Attached to this base 1 are a substrate 3 and a PC board 4 that hold a motor 2 whose rotation direction is selectively controlled to be forward or reverse. A drive shaft 5 directly connected to the motor 2 projects from the base 1, and a disk holder 6 is fixed to the projecting end. A movable body 8 holding a magnetic head 7 is supported on the base 1 so as to be rotatable by a shaft 10 and biased counterclockwise by a spring 9. A presser arm 12 for holding a pad 11 is attached to the movable body 8 by a spring 13.
It is biased toward the side and connected by a shaft 14 so as to be able to rise and fall freely. Projections 15 formed on both sides of the rear of the base 1
A cover 18 having a support portion 17 for supporting the magnetic disk 16 is urged toward the base 1 by a spring 19 and is rotatably attached to the base 1 by a hinge 20.

Next, a gear case 21 is fixed to the base 1, and a support shaft 2 that rotatably supports a drive pulley 22, which is a rotation output section, is attached to the end of the gear case 21.
3 are erected. A gear 24 is integrally formed on the disk holder 6, and a plurality of gears 25, which sequentially transmit the rotation of the gear 24 to the drive pulley 22,
26, 27, 28, 29, 30 are gear case 21
It is stored in. And these gears 24~
30 forms a speed reduction mechanism 31. Further, a notch 32 is formed in a part of the outer periphery of the gear 30, and a stopper 33 located in this notch 32 is erected on the base 1.

Then, the steel belt 34 whose one end is fixed to the drive pulley 22 is bent into a V shape by a pulley 35 fixed to the movable body 8, and then the steel belt 34 is bent into a V shape by a pulley 35 fixed to the movable body 8.
The screw 40 is passed through the groove 37 of the pin 36, which is an upright support part, and is attached to the support plate 38, which is a support part whose tip end is fixed to the base 1, together with the leaf spring 39.
Fixed by A leaf spring 3 is attached to the support plate 38.
An adjustment screw 41 that pushes 9 is screwed together, and these leaf springs 39 and the adjustment screw 41 form an adjustment mechanism 42 that changes the effective length of the steel belt 34 between the drive pulley 22 and the pin 36.

Furthermore, the cover 18 includes leaf springs 43 that press against both sides of a flat hard case (not shown) in which the magnetic disk 16 is housed, and a plate that retracts the presser arm 12 from the magnetic disk 16 when the cover 18 is opened. 44 is fixed. cover 18
A switch 45 for detecting opening/closing operations is attached to the base 1 via a bracket 46.

As shown in FIG. 4, a microcomputer 47, a motor control circuit 48, and a motor drive circuit 49 for the motor 2 are connected in sequence. these are
It is held on the PC board 4.

In such a configuration, when the motor 2 is rotated forward, the magnetic disk 16 and the drive pulley 22 rotate counterclockwise, and the steel belt 34 is pulled by the drive pulley 22, so that the movable body 8 is rotated around the shaft 10. During this process, information is recorded or reproduced. When the motor 2 is reversed, the drive pulley 22 rotates clockwise to loosen the steel belt 34, and the movable body 8 rotates counterclockwise by the force of the spring 9, causing the magnetic head 7 to move toward the magnetic disk 1.
Return to the home position on the inner circumferential side of No. 6. During one reciprocating motion of the movable body 8, all the power transmission members repeat normal rotation and reverse rotation, so each gear 24 to 3
The meshing range of the 0 teeth remains constant no matter how many times the movable body 8 is reciprocated. Therefore, the home position and movement range of the movable body 8 are always constant, and off-track can be prevented.

Adjustment of the home position of the magnetic head 7 during assembly is accomplished accurately and easily by turning the adjustment screw 41 and changing the effective length of the steel belt 34 between the pin 36 and the drive pulley 34. The steel belt 34 is connected to the adjustment screw 4 via the leaf spring 39.
Since it receives a pressure of 1, it will not be damaged, and since it is pressed by the leaf spring 39, it will not come off from the groove 37 of the pin 36.

Since the steel belt 34 is folded back by the pulley 35, the amount of movement of the movable body 8 can be halved relative to the length pulled by the drive pulley 22. That is, the steel belt 34 also exhibits a deceleration effect on the power transmission path, and allows the movable body 8 to move minutely to obtain an accurate tracking effect.

Since the steel belt 34 does not need to form a single loop in the middle portion, the shape is simple and it is advantageous for material removal during press punching.

The microcomputer 47 outputs a forward/reverse switching signal for the motor 2 in response to the operator's operation, and the motor control circuit 48 that receives this signal controls the motor drive circuit 49, so that during forward rotation, the speed is set to a speed suitable for recording or reproducing information. The motor 2 is rotated in the reverse direction, and the motor 2 is rotated at high speed during reverse rotation to save time.

The microcomputer 47 that controls the operation rarely generates an error, and the motor 2 may not stop. In this case, the stopper 33 located in the notch 32 forcibly prevents the gear 30 from overrunning. Therefore, no load is placed on the movable body 8, the steel belt 34 does not stretch or break, and the adjusted home position of the movable body 8 does not go out of order.

Effects of the Invention Since the present invention is configured as described above, the meshing range of the gear teeth in the speed reduction mechanism can be made constant by rotating the motor in forward and reverse directions to reciprocate the movable body. As a result, the home position of the movable body does not change each time the movable body moves back and forth, which makes it possible to reliably prevent the occurrence of off-track.Furthermore, the steel belt can be folded back at a part of the movable body. By doing so, it is possible to increase the reduction ratio and enable minute movements of the movable body, further improving tracking accuracy.Furthermore, the steel belt does not need to form a loop in the middle, simplifying the shape. When manufacturing using a press, material removal is advantageous and manufacturing is easy. Furthermore, the effective length of the steel belt between the support part and the leaf spring can be changed using an adjustment mechanism to accurately maintain the home position of the movable body. It also has the advantage of being easy to adjust.

[Brief explanation of drawings]

The drawings show one embodiment of the invention.
2 is a scaled-down exploded perspective view, FIG. 3 is a longitudinal side view, and FIG. 4 is a block diagram showing a motor drive circuit. 2... Motor, 7... Magnetic head, 8... Movable body, 16... Magnetic disk, 22... Drive pulley (rotation output section), 24-30... Gear, 31... Reduction mechanism, 34... Steel belt, 35... Pulley (part of movable body), 38... Support plate (support part),
39...Plate spring, 41...Adjustment screw, 42...Adjustment mechanism.

Claims (1)

[Claims] 1 A drive shaft that rotates a magnetic disk and a movable body that holds a magnetic head and reciprocates in the radial direction of the magnetic disk are provided, and the input side of a speed reduction mechanism including a plurality of gears is connected to the drive shaft in the rotational direction. is connected to a motor that is selectively controlled in either forward or reverse direction, biases the movable body in one direction, one end is connected to the rotational output part of the reduction mechanism, and the intermediate part is connected to a part of the movable body. A support part that supports the steel belt between the folded part of the movable body and the support part, the steel belt being folded back and having its other end fixed to a support part to pull the movable body against the biasing force. a plate spring that is fixedly provided, one end of which is fixed to the support portion, and presses the steel belt against the support portion;
A magnetic recording device characterized in that an adjustment mechanism is provided that includes an adjustment screw that is screwed onto the support portion and presses and bends the leaf spring between the support portion and the fixed end of the leaf spring. .