JPH047031B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention relates to a magnetic disk recording/reproducing device.

(Prior Art) In recent years, recording and reproducing devices using magnetic disks have been widely used. This recording/reproducing device has the advantage of being able to record and reproduce information in a few milliseconds, and has excellent so-called random accessibility.
This advantage is realized by moving a magnetic head for recording and/or reproducing data onto concentric tracks formed or to be formed on a recording medium at high speed in the radial direction of the magnetic disk.

By the way, when performing magnetic recording and reproduction in this manner, the following problems have conventionally occurred.

(1) Until the rotational speed of the magnetic disk reaches a certain value or more, that is, the relative speed between the magnetic disk and the magnetic head reaches a certain value or more, even if the magnetic head is brought into contact with the magnetic disk, the contact between the two will be unstable. ,
There was a risk of damage to the magnetic head or magnetic disk. For this reason, a magnetic recording/reproducing device has been proposed in which the magnetic head is separated from the magnetic disk when the rotation speed of the magnetic disk does not reach a certain value or higher when the rotation starts or stops.
No. 72762). This magnetic recording/reproducing device uses an electromagnet to attract a leaf spring that presses the magnetic head against the surface of the magnetic disk until the rotational speed of the magnetic disk reaches a certain value, thereby separating the magnetic head from the magnetic disk. Then, when the rotational speed of the magnetic disk reaches a specified value, the attraction by the electromagnet is released and the magnetic head is brought into contact with the surface of the magnetic disk. However, in this device, when the magnetic head is sent in the radial direction of the magnetic disk, the magnetic head remains in sliding contact with the magnetic disk, so the wear of the magnetic surface of the magnetic disk and the wear of the magnetic head are reduced. There is a problem that the number of cases increases significantly.

(Objective) An object of the present invention is to provide a magnetic disk recording/reproducing apparatus in which a magnetic head is brought into contact with a magnetic disk only when performing a recording or reproducing operation on the magnetic disk.

(Summary) The magnetic disk recording and reproducing device according to the present invention includes:
A carriage to which a magnetic head is fixed is slidably supported so that the magnetic head can move in the radial direction of the magnetic disk, and also supported so that the magnetic head can move toward and away from the magnetic surface of the magnetic disk. The present invention is characterized in that the magnetic head is separated from the magnetic disk until the disk reaches a predetermined rotation and while the magnetic head is moved in the radial direction of the magnetic disk.

(Example) The present invention will be described below based on an example shown in FIGS. 1 and 3.

Bearings 2 and 3 are integrally formed at both ends of one longitudinal edge of the substrate 1, which has a rectangular planar shape, and project from the surface of the substrate 1, respectively.
A guide shaft 4, which is a guide member, is spanned between both bearing parts 2 and 3, and its both ends are held by holding plates 5 and 6.
The coaxial 4 is fixed to the substrate 1 by being pressed down by the . A carriage 7 that is slidable in the axial direction of the guide shaft 4 is disposed on the guide shaft 4 . This carriage 7 has an inverted L-shape in plan view, and one vertical portion of the carriage 7 is inserted into the guide shaft 4 . The carriage 7 can be rotated by a predetermined angle around the guide shaft 4, that is, rotated clockwise and counterclockwise. They are placed side by side. A roller support plate 10 is inserted between both rollers 8 and 9. The roller support plate 10 is configured such that its both side edges can be rotated in the vertical direction by a magnetic head vertical movement device 11. As shown in FIG. 3, the magnetic head vertical movement device 11 has a channel-shaped frame 12 fixed on the substrate 1 and having an open side facing the horizontal end surface of the carriage 7. A support shaft 13 suspended horizontally within the frame body 12 is fixed to both front and rear walls of the frame body 12. The roller support plate 10 is rotatably attached to the support shaft 13 so as to pass through the middle thereof.
One side edge of this roller support plate 10 extending toward the horizontal end surface of the carriage 7 is sandwiched between the rollers 8 and 9, and the other side edge extending toward the inside of the frame. Adjustment screws 14 and 15 for position regulation are screwed into the frame from above and below.
The tips of the roller support plates 10 are brought into contact with each other, and the range of rotation of the roller support plate 10 is restricted. Further, a tension spring 16 is provided between the upper surface of the roller support plate 10 and the inner surface of the upper wall of the frame, and a solenoid 17 is attached to the lower wall of the frame 12 opposite to the tension spring 16. . In the magnetic head vertical movement device 11 configured in this way,
When the coil of the solenoid 17 is de-energized,
The tension force of the tension spring 16 causes the roller support plate 10 to
rotates clockwise around the support shaft 13, and the upper surface of the other side edge is in contact with the lower end of the adjustment screw 14, and when energized, the other side of the roller support plate 10 is held by the magnetic attraction force of the solenoid 17. By attracting the edge, the roller support plate 10 rotates counterclockwise about the support shaft 13, and the lower surface of the other side edge comes into contact with the upper end of the adjustment screw 15.

On the other hand, a magnetic head 18 for recording video signals and the like on a magnetic disk 40 and reproducing signals recorded on the disk 40 is fixedly supported on the outer surface of the horizontal portion of the carriage 7. Further, a square hole 19 parallel to the guide shaft 4 is bored through the horizontal portion of the carriage 7 near the guide shaft. Inside this square hole 19, a light receiving part and a main scale of an optical linear encoder 50 are arranged integrally with the carriage 7, and an index scale 20 facing this main scale passes through the inside of the square hole 19. It is well arranged. Both ends of the index scale 20 are fixed to mounting portions protruding from the plate surface of the substrate 1. A light emitting section 21 is embedded in a portion of the carriage 7 that faces the top surface of the index scale 20.

On the other hand, a disk drive motor 22 for giving a predetermined rotation to the magnetic disk 40 is attached to a central portion of the board surface of the substrate 1 surrounded by the inverted L-shaped carriage 7.

Further, the motor 22 on the board surface of the board 1
A cam mechanism 23 is disposed at a position facing the horizontal portion of the carriage 7 with the cam mechanism 23 in between. This cam mechanism 23 is for sliding the carriage 7 along the guide shaft 4 and the roller support plate 10 and moving the magnetic head 18 in the radial direction of the magnetic disk 40. A stepping motor 24, which is a motor for driving the mechanism, is attached.
An output shaft 25 of the motor 24 passes through the substrate 1 and extends above the top surface, and a first plate cam 26 and a second plate cam 27 are fixed to the output shaft 25.
Further, the base of a protruding arm 28 extending parallel to the horizontal part of the carriage 7 is fixed to the distal end of the vertical part of the carriage 7, and the upper surface of the distal end of the protruding arm 28 has a first base. A roller 29 is rotatably and fixedly supported. And this first roller 2
9 is in contact with the operating cam surface of the first plate cam 26. Also, a relatively thick thin strip-shaped leaf spring 3
The base end of the plate spring 30 is fixed to the distal end surface of the vertical part of the carriage 7, and the distal end of the leaf spring 30 has a second plate spring 30 that contacts the operating cam surface of the second plate cam 27.
rollers 31 are supported. This roller 31
For installation, a cutout 34 is formed in the center of the leaf spring 30 along the longitudinal direction of the leaf spring 30, and the upper and lower ends of the leaf spring 30 are separated. The second roller 31 is wound around the upper and lower ends of a rotatably supported shaft 32, so that the shaft 32 is fixed to the tip of the leaf spring 30.

The operating cam edge of the first plate cam 26 is connected to the output shaft 2.
5, and the difference between the minimum diameter and the maximum diameter of the plate cam 26, that is, the operating stroke, is set approximately equal to the movement range of the magnetic head 18 in the radial direction of the magnetic disk. has been done.
Further, the second plate cam 27 also has a substantially symmetrical shape with the first plate cam 26, and both plate cams 26, 2
7, the positional relationship between the cam surface of the first plate cam 26 and the circumferential surface of the first roller 29, and the contact point between the cam surface of the second plate cam 27 and the second roller The straight line distance connecting the point of contact with the plate cam 31 is approximately equal over the rotation range of the plate cams 26 and 27, which is approximately one revolution.

Note that the optical linear encoder 50 is
The operation of the stepping motor 24 is controlled based on the overlap of the slits formed in the main scale and the index scale 20, which are formed by the main scale, the light receiving section, the index scale 20, and the light emitting section 21. This is to obtain position detection information of the carriage 7 for closed loop control.

In the above embodiment, the magnetic head 18 is thus attached to the carriage 7 at a location spaced apart from the location where the carriage is rotatably supported by the guide member 4 by a predetermined first distance. In addition, an elastic body 16 is provided which applies a rotational biasing force to cause the head 18 to be rotated in a direction in which it is retracted from the magnetic disk 40 to which the head 18 is applied. along the same direction as the first distance from the rotatably supported part.
The carriage 7 is rotated around the guide member 4 against the rotation biasing force of the elastic body 16 by applying a driving force to a portion separated by a distance longer than the distance . The head 18 attached to the carriage 7 is connected to the magnetic disk 4.
An actuator consisting of a magnetic head up/down device 11 is provided for displacing the magnetic head in the direction of protruding toward the direction 0. The carriage 7 is rotated by the driving force of the actuator 11 by locking at a portion separated by a second distance longer than the first distance along the same direction as the distance. A position regulating member consisting of a roller support plate 10, a frame 12, a spindle 13, and adjustment screws 14 and 15, which regulates the amount of protrusion when the head 18 is displaced toward the magnetic disk 40. are arranged.

The magnetic disk recording and reproducing apparatus of this embodiment is thus configured. The operation will be explained below. When the magnetic disk is attached to the output shaft of the motor 22 via a chucking member (not shown) and the start button is pressed, the coil of the solenoid 17 of the magnetic head vertical movement device 11 is not energized until the magnetic disk reaches a predetermined rotation. Not done. Therefore,
The roller support plate 10 rotates clockwise around the support shaft 13 due to the elasticity of the tension spring 16, and in conjunction with this, the carriage 7 rotates counterclockwise around the guide shaft 4 to generate magnetic force. The head 18 is displaced to a position away from the magnetic surface of the magnetic disk 40.

Then, when the magnetic disk 40 reaches a predetermined rotational speed and is in a state where stable recording or reproducing operation can be performed, the coil of the solenoid 17 is energized. When the coil of the solenoid 17 is energized, the attraction force of the solenoid 17 causes the roller support plate 1 to
0 rotates on the support shaft 13 as a fulcrum against the elasticity of the tension spring 16 toward the solenoid 17, and the lower surface of the other side edge of the roller support plate 10 comes into contact with the upper end of the adjustment screw 15. Then, the roller 8 is pushed upward by the roller mounting plate 10, and the carriage 7 is rotated upward about the guide shaft 4, so that the magnetic head 18 comes into contact with the magnetic surface of the magnetic disk 40. Therefore, the desired recording or reproducing operation can be performed stably in this contact state.

Also, at this time, the optical linear encoder 50
As a result, information on the position of the carriage 7, in other words, the position of the magnetic head 18 can be obtained.

Next, when moving the magnetic head 18 closer to the motor 22, the stepping motor 2
When the output shaft 25 of No. 4 is rotated clockwise, the first plate cam 26 rotates clockwise around the output shaft 25, and along with this, the first roller 29 and the first plate are rotated clockwise. The contact point of the cam 26 with the cam surface approaches the output shaft 25. Therefore, the carriage 7 slides on the guide shaft 4 and moves in the direction of arrow X, and the magnetic head 18 approaches the motor 22. Such movement of the carriage 7 is continued until the output information of the optical linear encoder 50 matches the information corresponding to the desired position, and at the time when the desired position is detected by the optical encoder 50. Then, the stepping motor 24 is brought into a non-driving state by a control circuit (not shown) to which information from the encoder 50 is input. In this way, the carriage 7 can be reliably moved to a desired position, or in other words, the magnetic head 18 can be accurately moved to a desired position on the magnetic disk.

Also, while the magnetic head 18 is being sent in the radial direction of the magnetic disk 40 in this way, the solenoid 1
Since the coil 7 is not energized, the tension force of the tension spring 16 causes the roller support plate 1 to
0 rotates clockwise around the support shaft 13, and the upper surface of the other side edge of the roller support plate 10 comes into contact with the tip of the adjustment screw 14. Therefore, since the roller support plate 10 pushes the roller 9 downward, the carriage 7 also rotates counterclockwise around the guide shaft 4, and the magnetic head 18 is separated from the magnetic disk 40.

On the other hand, when moving the magnetic head 18 in a direction away from the motor 22, the stepping motor 24 is rotated counterclockwise in the opposite direction. Then, the carriage 7 can be moved in the direction of the arrow Y by performing the opposite operation to the previous one. While the carriage 7 is being moved in the direction of the arrow Y in this manner, the coil of the solenoid 17 is not energized, so the tension force of the tension spring 16 causes the roller support plate 10 to slide out of the adjustment screw. 1
The carriage 7 rotates clockwise around the support shaft 13 until it comes into contact with the tip of the carriage 7.
The magnetic head 18 is also rotated counterclockwise, and the magnetic head 18 is separated from the magnetic surface of the magnetic disk 40.

In addition, in the above embodiment, two plate cams 2
6 and 27 constitute a cam mechanism 23, which moves the carriage 7 in the radial direction of the magnetic disk.This is achieved by arranging a DC motor 60 parallel to the guide shaft 4, as shown in FIG. However, a feed screw mechanism may be used in which a feed screw 62 is fixed to the output shaft 61 of the motor 60, and a feed rod 63 that presses against the feed screw 62 is fixed to the side surface of the carriage 7.

In this case, by rotating the output shaft 61 of the DC motor 60, the feed rod 63 that is in pressure contact with the feed screw 62 moves in the axial direction of the guide shaft 4, and the carriage 7 moves accordingly. By sliding in the axial direction of the guide shaft 4, the magnetic head 18 can be moved in a desired radial direction of the magnetic disk 40. It goes without saying that during such a feeding operation of the magnetic head 18, the magnetic surface of the magnetic disk 40 and the magnetic head 18 are separated by the operation of the magnetic head vertical movement device 11, as described above.

Furthermore, instead of the magnetic head vertical moving device 11 as shown in FIG. 3, a magnetic head vertical moving device 11A constructed as shown in FIG. 5 may be used.
That is, the roller support plate 10A is formed of a plate bent at a substantially right angle, and the lower surface of the tip of one side edge extending horizontally is connected to the roller 9 attached to the tip of the horizontal portion of the carriage 7. The upper surface of the tip of the same side edge is in contact with the upper peripheral surface of the carriage 7.
The horizontal end of the roller support plate 10A is in pressure contact with a sliding piece 8A attached via a leaf spring 8B, and the horizontally extending edge of the roller support plate 10A is held between the roller 9 and the sliding piece 8A. It is included.

Further, the inner surface of the right-angled bent portion of the roller support plate 10A is supported by a rotation support shaft 13A, and the roller support plate 10A can slide around the rotation support shaft 13A. and roller support plate 1
A compression spring 16A is disposed between the inner surface of the tip of the other side edge extending downward and the stationary member 1A, and applies clockwise rotational force to the roller support plate 10A. . However, this rotation is restricted by the adjustment screw 14A. The adjustment screw 14A is screwed into the stationary member 1A so that its tip abuts the outer surface of the tip of the other side edge of the roller support plate 10A. Also, this adjustment screw 1
An adjustment screw 15A is screwed into the fixed member 1A at a position opposite to the roller support plate 10.
The counterclockwise rotation position of A is regulated. Also, a solenoid 1 is located above this adjustment screw 15A.
7A is installed.

In the vertical movement device 11A configured in this way, the coil of the solenoid 17A is energized until the rotation of the magnetic disk 40 reaches a predetermined rotation speed and when the magnetic head 18 is sent in the radial direction of the magnetic disk 40. During this period, the roller support plate 10A rotates clockwise around the support shaft 13A until it comes into contact with the adjustment screw 14A due to the elasticity of the compression spring 16A. As a result, the carriage 7 rotates counterclockwise about the guide shaft 4, and as a result, the magnetic head 18 becomes separated from the magnetic surface of the magnetic disk 40.

On the other hand, when the coil of solenoid 17A is energized,
That is, when the magnetic disk 40 reaches a predetermined rotational speed and the feeding of the magnetic head 18 is completed, the solenoid 17A generates a magnetic attraction force by energizing the coil of the solenoid 17A, thereby causing the roller support plate to 10A is attracted against the elasticity of the compression spring 16A, and the roller support plate 10A is attached to the support shaft 13A.
As a result, the carriage 7 rotates clockwise around the guide shaft 4, and the magnetic head 18 is brought into contact with the magnetic disk 40, thereby recording and recording the desired data. Or a playback operation is performed.

In each of the above embodiments, in order to rotationally displace the carriage supporting the magnetic head in the direction in which the magnetic head comes into contact with the magnetic disk and in the direction in which it moves away from the magnetic disk, the horizontal portion of the flat L-shaped carriage is used. Although the distal end of the vertical movement device is engaged with the vertical movement device, the engagement position of the vertical movement device with respect to the carriage is not limited to the position in the above embodiment, for example, the middle position of the horizontally extending portion of the carriage. Alternatively, it is of course possible to provide a horizontal portion extending on the opposite side to the horizontal portion and rotate this horizontal portion by a vertical movement device.

(Effects) As described above, according to the present invention, the accuracy of the amount of protrusion of the magnetic head toward the magnetic disk can be easily ensured.

The head can be moved up and down as desired with sufficient responsiveness using a relatively low output actuator.

The magnetic head is protruded when the actuator works, and the head is retracted by the rotational biasing force of the elastic body 16 when the actuator is not working. Since the head is always automatically placed in the retracted position when
This is desirable in order to prevent permanent deformation of the magnetic disk, and is also desirable in terms of power saving effect. Further, even when the actuator stops working due to equipment failure, power outage, or drop in power supply voltage during battery operation, the head is always placed in the retracted position, which is desirable in order to protect the magnetic disk.

Remarkable effects such as these can be obtained.

[Brief explanation of drawings]

FIG. 1 is a perspective view of a magnetic disk recording and reproducing apparatus showing one embodiment of the present invention, and FIG.
3 is a cross-sectional view of the main part of the magnetic disk recording and reproducing apparatus shown in FIGS. 1 and 2, and FIG. 4 is a schematic enlarged plan view of the magnetic disk recording and reproducing apparatus shown in FIG. FIG. 5 is a perspective view of a magnetic disk recording and reproducing apparatus showing another embodiment of the present invention, and FIG. 5 is a sectional view of a main part showing another example of a magnetic head vertical movement device. 4... Guide shaft (guide member), 7... Carriage, 10, 10A... Roller support plate (support member), 11, 11A... Magnetic head vertical movement device,
18...Magnetic head.

Claims (1)

[Scope of Claims] 1. A guide member disposed so as to extend in a predetermined direction; and a predetermined portion of the guide member that is rotatably supported by the guide member and guided in a direction by the guide member. a magnetic head mounted on the carriage at a location spaced a predetermined first distance from a location where the carriage is rotatably supported by the guide member; an elastic body that applies a rotational urging force to the carriage so that the head attached to the carriage is rotationally displaced in a direction to retreat from the applied magnetic disk; The carriage is rotated by the elastic body by applying a driving force to a part that is separated by a distance longer than the first distance along the same direction as the first distance from the rotatably supported part. an actuator that rotates around the guide member against a biasing force and displaces the head attached to the carriage in a direction in which it projects toward the magnetic disk; The carriage is locked at a position spaced apart from a position rotatably supported by the guide member by a second distance, which is longer than the first distance, along the same direction as the first distance. Therefore, when the carriage is rotated by the driving force of the actuator and the head is displaced in the direction of protrusion toward the magnetic disk, the magnetic head is provided with a position regulating member that regulates the amount of protrusion. A magnetic disk recording and reproducing device characterized by the following.