JPH06267225A - Actuator lock mechanism and recording and reproducing device using the same - Google Patents

Abstract

PURPOSE:To enhance the lock strength without upsizing the device and to make the lock sharp in function without impairing to a high speed and high precision head positioning function. CONSTITUTION:A side surface of a frame 11 of a carriage arm 7 is brought into contact with a stopper 12, and is stopped to utilize leakage flux of a permanent magnet 13 constituting a voice coil motor. Then, a magnetic member 16 is provided for the purpose of making the leakage flux to be generated from a projecting part 15 of the permanent magnet 13 flow in the direction of attracting a pin 14 consisting of a magnetic material provided on a tip of the frame 11 at the time of fixing the frame by attracting the pin 14.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention positions a recording / reproducing head (hereinafter referred to as "head") for recording / reproducing information on an information recording medium (hereinafter referred to as "disk") at an arbitrary position on the disk. The present invention relates to an actuator lock mechanism for fixing a head in an unrecorded area (hereinafter referred to as “CSS zone”) on a disk when the actuator is not operating, and a recording / reproducing apparatus using the actuator lock mechanism.

[0002]

2. Description of the Related Art In recent years, there has been an increasing demand for a small-sized and large-capacity recording / reproducing apparatus, especially a magnetic disk apparatus. As a result of recent technological development, higher recording density has been realized by improving track density (density in the disk radial direction) and bit density (density in the disk circumferential direction), and the magnetic disk device is a laptop type or a notebook type. It is attracting attention as a storage device for personal computers that is convenient to carry.

Along with this, the head is small and can be accessed at high speed and with high precision, and further, the head is disengaged from the CSS zone on the disk due to an external shock generated when the apparatus is powered off and carried. There have been many attempts to provide actuators that can be fixed so that they do not happen.

FIG. 8 shows an outline of an actuator lock mechanism in a conventional magnetic disk device.
In order to move the head to a predetermined position on the disk, a head (not shown) is supported at one end and the drive coil 10 is provided at the other end.
1, a carriage arm 103 having a frame 102 for holding 1, a drive coil 101 and a drive coil 10.
Permanent magnets 104 provided so as to face each other so as to sandwich 1 therebetween.
And an actuator composed of a voice coil motor having a magnetic circuit composed of the yoke plates 105 and 106. The carriage arm 103 is rotatably provided around an axis, and the head is positioned at a predetermined position on the disk by rotating the carriage arm. In recent actuator lock mechanisms, in order to reduce the number of parts as much as possible, the leakage flux of the permanent magnet 104 that constitutes the magnetic circuit of the voice coil motor that drives the carriage arm is used to drive the drive coil 101 on the carriage arm 103. A pin 10 made of a magnetic material is attached to the tip of the frame 102 to be held.
7 is attached, and the pin 107 is attracted by the magnetic force generated by the above-mentioned leakage magnetic flux to fix the carriage arm 103 at a predetermined position, thereby fixing the head to the CSS zone on the disk. Has been adopted. In particular, when the actuator is not in operation, it is necessary to effectively generate the leakage magnetic flux in the vicinity of the pin 107, and as shown in the figure, the permanent magnet 104 near the lock position of the pin 107 in the non-operation is attached to the carriage arm 103. On protrusion 1
08 is provided.

By the way, according to such a method, a certain degree of lock strength is required in order to fix the head so as not to come off from the CSS zone on the disk even when an external shock is applied. In order to improve the lock strength, the strength of the magnetic attraction force generated by the leakage magnetic flux generated from the permanent magnet 104 and the carriage arm 1 are increased.
It is necessary to increase the lock torque force given by the product of the distance from the rotation center of 03 to the lock position. In order to increase the lock torque force, the permanent magnet 1 described above is used.
It is necessary to lengthen the frame 102 in order to increase the volume of the protrusion 108 of No. 04 to strengthen the magnetic attraction force or to move the lock position away from the rotation center of the carriage arm 103.

However, if the frame 102 of the carriage arm 103 is lengthened, the moment of inertia of the carriage arm 103 becomes large, which makes it difficult to access the head at high speed and with high precision, and also because the carriage arm 103 itself becomes large. This is against the demand for miniaturization of the device. In addition, the protruding portion 108 of the permanent magnet 104
When the volume is increased, the lock strength when the head is fixed to the CSS zone can be increased, but the area where the leakage magnetic flux is generated is also enlarged. Therefore, when the head is moved to the recording area, the carriage arm 104 is moved. The magnetic attraction force that tries to return to the fixed position acts. In addition, the head is CS
The magnetic attraction force also acts on the recording area close to the S zone. That is, the lock breaks worse. In normal actuator control, in order not to complicate the configuration of the control system, it is required to keep the driving force of the carriage arm 104 constant when the head is in the recording area. However, as described above, in the case where the lock is not easily broken, the external force acts while the head is in the recording area, and it is necessary to consider such an influence, so that the control system is complicated. In addition, it may become difficult to position the head at high speed and with high accuracy.

As described above, in the conventional actuator lock mechanism, if the lock strength is further increased, the size of the device becomes large and the lock breaks badly, which makes it difficult to position the head at high speed and with high accuracy. , Becomes an obstacle to the improvement of recording density. On the other hand, unless the lock strength can be increased, it is difficult to construct a highly reliable device against an external impact or the like.

[0008]

As described above,
In a conventional recording / reproducing device using an actuator lock mechanism, if the lock strength is further increased, the device becomes large or the lock breaks poorly, making it difficult to position the head at high speed and with high accuracy. Therefore, there is a problem such as an obstacle to the improvement of the recording density.

In view of the above, the present invention solves the above-mentioned problems, can increase the lock strength without increasing the size of the device, and has a good lock break, which does not impair the high-speed and high-accuracy positioning function of the head. An object of the present invention is to provide a mechanism and a recording / reproducing device using the same.

[0010]

To achieve the above object, the present invention has a function of positioning a recording / reproducing head for recording / reproducing information on / from an information recording medium at a predetermined position on the information recording medium. A first magnetic member provided on the arm, a permanent magnet that constitutes a driving means for driving the arm, and the first magnetic member when the arm is not in operation. The second magnetic member is provided at a position where the leakage magnetic flux of the permanent magnet can be guided in a direction in which the first magnetic member is attracted, because the second magnetic member is fixed at a predetermined position by an attractive force. The actuator lock mechanism is characterized in that there is a predetermined gap between the first magnetic member and the second magnetic member when the arm is not operating. Click mechanism, as well as an information recording medium,
Rotating means for holding the information recording medium, a recording / reproducing head for recording / reproducing information on / from the information recording medium, and an arm having a function of positioning the recording / reproducing head at a predetermined position of the information recording medium. A first magnetic member provided on the arm, a permanent magnet constituting a driving means for driving the arm, and a non-operating state of the arm,
Since the first magnetic member is fixed at a predetermined position by the magnetic attraction force due to the leakage flux of the permanent magnet, the first magnetic member is positioned at a position where the leakage flux of the permanent magnet can be guided in the direction of attracting the first magnetic member. A recording / reproducing apparatus having a second magnetic member provided.

[0011]

According to the above-described structure of the present invention, when the arm having the function of positioning the recording / reproducing head for recording / reproducing information on / from the information recording medium at a predetermined position on the information recording medium, the arm is not operated. The first magnetic member provided in
It can be fixed at a predetermined position by the magnetic attraction force due to the leakage magnetic flux of the permanent magnet that constitutes the driving means for driving the arm. At that time, the second magnetic element is placed at a position where the leakage flux of the permanent magnet can be guided in the direction in which the first magnetic member is attracted.
By providing the magnetic member, the magnetic flux density in the vicinity of the lock position of the first magnetic member can be increased, so that the magnetic attraction force particularly in the vicinity of the lock position can be increased. On the other hand, since the volume of the permanent magnet is not increased, the region where the leakage magnetic flux is generated does not expand and the lock breakage does not deteriorate.

[0012]

Embodiments of the present invention will be described in detail with reference to the drawings. Here, an example of a magnetic disk device will be described as an example of the recording / reproducing device, but the present invention is not limited to this case, and is applicable to other recording / reproducing devices such as an optical disk.

FIG. 7 schematically shows a magnetic disk device provided with an actuator lock mechanism according to the present invention. A magnetic disk 1 for recording information is mounted on a spindle motor 2 and rotated at a constant speed. The magnetic disks 1 are arranged such that one or a plurality of magnetic disks are laminated. A magnetic head 3 for accessing the magnetic disk 1 to record and reproduce information is attached to the tip of a thin plate-shaped suspension 4. In addition, suspension 4
Is connected to one end of the carriage arm 5. Here, the same effect may be provided by forming the tip of the carriage arm 5 into a thin plate shape without providing the suspension 4 in particular. A frame for holding a drive coil is provided at the other end of the carriage arm 5, and is composed of a drive coil held by the frame, a permanent magnet and a yoke plate which are arranged to face each other so as to sandwich the drive coil. The magnetic circuit constitutes a voice coil motor 6 which is a kind of linear motor. The carriage arm 5 is held by ball bearings (not shown) provided at two positions above and below the fixed shaft 7, and can be freely rotated and rocked by the voice coil motor 6 described above.

The magnetic head 3 on the magnetic disk 1
The positioning is performed by reading the servo information written on the magnetic disk 1 by the magnetic head 3 and rotating the carriage arm 5 by a positioning servo system that feeds back this information to the voice coil motor 6.

The above-mentioned components are arranged in a housing 8 and covered from above by a cover 9 on a thin plate to hermetically seal the entire device to form a magnetic disk device. As described above, it is necessary to retract the magnetic head 3 to the CSS zone on the magnetic disk 1 (usually the inner circumference side of the magnetic disk 1) when the apparatus is not operating. Even if an external shock is applied when carrying the device, the magnetic head 3
Must be kept out of the area. Therefore, the present invention proposes the following actuator lock mechanism and experimentally proves its usefulness.

FIG. 1 is a schematic view showing a first embodiment of an actuator lock mechanism according to the present invention. Figure 1 (a)
FIG. 1A is a top view of the periphery of a voice coil motor that constitutes an actuator, and FIG. 1B is a side view of the same. Also, the figure is
The magnetic head 3 (not shown) is fixed to the CSS zone on the magnetic disk 1 (not shown). Here, the carriage arm 7 that supports the magnetic head 3 via the suspension 4 is
The side surface 1 contacts the stopper 12 and stops, and is fixed by the actuator lock mechanism according to the present invention. The actuator lock mechanism according to the present invention utilizes the leakage magnetic flux of the permanent magnet 13 constituting the voice coil motor 6 and attracts the pin 14 made of a magnetic material provided at the tip of the frame 11 as in the conventional case. It is based on the fixed magnet lock system. In this embodiment, the magnetic member 16 is provided at a position facing the protrusion 15 of the permanent magnet 13.
Is provided. As shown in FIG. 1B, the magnetic member 16 is attached to the upper yoke plate 17 forming the magnetic circuit of the voice coil motor 6, and its thickness is almost the same as that of the permanent magnet 13. When locked, pin 14
And the magnetic member 16 are not in contact with each other. This is to prevent the lock mechanism from being damaged due to the pin 14 colliding with the magnetic member 16. The carriage arm 7 stops without contacting the two, and the lock mechanism functions sufficiently. As described above, the position of the stopper 12 described above is determined. In addition, the stopper 12 is provided in order to reduce a shock when the side surfaces of the frame 11 come into contact with each other.
It is formed of a cushioning material such as rubber, and also has a function as a hard stop when the actuator goes out of control.

Next, the effect of providing the above-mentioned magnetic member 16 will be described. FIG. 2 is a schematic diagram showing the action of the magnetic attraction force in the actuator lock mechanism according to the first embodiment of the present invention. In the conventional actuator lock mechanism, the flow of the leakage magnetic flux due to the protruding portion 15 of the permanent magnet 13 is diffused toward the yoke plates 17 and 18 located above and below the permanent magnet 13 and is intended to particularly contribute to the lock force. Absent. On the other hand, in the present embodiment, by providing the magnetic member 16, the flow of magnetic flux as shown by the arrow in the drawing is formed, and the lock position of the pin 14 provided at the tip of the frame 11 of the carriage arm. Measures have been taken to increase the magnetic flux density in the vicinity. That is,
The leakage magnetic flux generated from the protrusion 15 of the permanent magnet 13 flows toward the magnetic member 16 in a direction to attract the pin 14, so that the magnetic attraction force particularly near the lock position can be increased. On the other hand, in this embodiment, since the volume of the protruding portion 15 of the permanent magnet 13 is not increased, the region where the leakage magnetic flux is generated is not expanded and the breakage of the lock is not deteriorated. Further, since a sufficient locking force can be obtained without increasing the size of the carriage arm 7, it is suitable for downsizing the device without impairing the high-speed and highly accurate positioning function of the magnetic head.

FIG. 3 shows the measurement result of the lock torque force of the actuator lock mechanism according to the first embodiment of the present invention. In the figure, the measurement results of the lock torque force of the conventional actuator lock mechanism are also shown. In the figure, the vertical axis represents the lock torque force, and the horizontal axis represents the rotation angle of the actuator with reference to when the magnetic head is located at the outermost periphery of the recording area. Here, the maximum lock torque force when locked is about 4 gf in the conventional example.
-Cm, whereas in the first embodiment of the present invention is about 12
It is about 3 times as large as gf · cm. Further, it can be seen that the rotation angles of the actuators at which the lock torque force starts to be generated are almost equal to each other and the lock is not broken easily. Therefore, an external force does not act while the magnetic head is in the recording area, and the control system of the actuator does not become complicated and high-speed and highly accurate positioning of the magnetic head does not become difficult.

FIG. 4 is a schematic view showing a second embodiment of the actuator lock mechanism according to the present invention. Figure 4 (a)
[Fig. 4] is a top view of the periphery of a voice coil motor forming an actuator, and Fig. 4 (b) is a side view of the same. Also, the figure is
The magnetic head 3 (not shown) is fixed to the CSS zone on the magnetic disk 1 (not shown). The same parts as those of the first embodiment shown in FIG. 1 are designated by the same reference numerals to omit redundant description.

In this embodiment, the protrusion of the permanent magnet 13 provided in the first embodiment is not provided. This is from the viewpoint of manufacturability that the protrusion is not easy to provide when manufacturing the permanent magnet 13 and that the effect of unnecessary external force caused by providing the protrusion is eliminated as much as possible. . Even with such a configuration, as shown in FIG. 5, since the flow of the leakage magnetic flux from the permanent magnet 13 can be guided, the pin 14 provided at the tip of the frame 11 of the carriage arm, as in the first embodiment. The magnetic flux density near the lock position can be increased. The other effects are similar to those of the first embodiment.

FIG. 6 shows the measurement result of the lock torque force of the actuator lock mechanism according to the second embodiment of the present invention. As shown in the figure, the maximum lock torque force at the time of locking in the actuator lock mechanism according to the present embodiment is about 9 gf · cm, which is lower than that of the first embodiment, but about twice as much as that of the conventional example. Indicates lock torque force. On the other hand, it can be seen that the actuator rotation angle at which the lock force begins to act is moved to the CSS zone side more than in the first embodiment, and the lock is broken well.

In the first and second embodiments described above, the magnetic member 16 provided near the permanent magnet 13 is
As described above, the voice coil motor 6 may be mounted on the upper yoke plate 17 forming the magnetic circuit,
Alternatively, a part of the yoke plate 17 may be cut out and bent so as to face the permanent magnet 13. Alternatively, the same effect can be obtained by providing a cylindrical step portion on the yoke plate 17 by a processing method called embossing.

Further, at the position where the protrusion 15 of the permanent magnet 13 is provided in the first embodiment or the position where the magnetic member 16 is provided in the first and second embodiments, the pin 14 made of a magnetic material on the carriage arm 7 is used. Even when the permanent magnet 13 is provided near the center where the magnetic pole of the permanent magnet 13 changes, the effect does not change, corresponding to the position where it is provided. In addition, various changes can be made without departing from the spirit of the present invention.

Next, an embodiment relating to another invention will be described. 9 and 10 show an outline of a method of fixing a fixed shaft for rotatably holding a carriage arm of a rotary swing actuator. FIG. 9 is a top view showing the outline of the rotary oscillating type actuator, and FIG. 10 is a partial sectional view thereof. As shown in the figure, the carriage arm 22 holding the drive coil 21 has two ball bearings 2
It is rotatably supported on a fixed shaft 25 via 3, 24. The fixed shaft 25 has a lower end fixed to the device base 26 and an upper end fixed to the upper yoke plate 27 by screws 28 and 29, respectively. A spindle motor (not shown) for rotating the magnetic disk is also fixed to the device base 26.

With such a structure, the height of the entire apparatus can be suppressed to the lowest. Further, even if the drive coil 21 and the carriage arm 22 generate bending vibration in the vertical direction, the vibration energy in the vertical direction is canceled because both ends of the fixed shaft are fixed. Therefore, since the servo gain in the positioning direction of the head 30 shown in FIG. 9 can be increased, the positioning of the head 30 can be performed at high speed and with high accuracy.

Further, even when an external force is generated in the drive coil 21 and the carriage arm 22 in an arbitrary direction and acts to incline and deform the fixed shaft 25, both ends of the fixed shaft 25 are fixed. Since the shaft 25 is not statically deformed, high positioning accuracy can be obtained regardless of the position of the head 30 on the disk.

[0027]

As described above, according to the present invention,
Since the magnetic attraction force in the vicinity of the lock position can be increased without increasing the size of the device and the volume of the permanent magnet is not increased, the region where the leakage magnetic flux is generated does not expand, and the lock breakage is worse. No actuator locking mechanism can be constructed. Therefore, it is possible to provide a recording / reproducing apparatus suitable for downsizing without impairing the high-speed and highly accurate positioning function of the head.

[Brief description of drawings]

FIG. 1 is a first part of an actuator lock mechanism according to the present invention.
The schematic diagram showing the example.

FIG. 2 is a schematic diagram showing the action of a magnetic attraction force in the actuator lock mechanism according to the first embodiment of the present invention.

FIG. 3 is a diagram showing measurement results of lock torque force of the actuator lock mechanism according to the first embodiment of the present invention.

FIG. 4 is a second actuator lock mechanism according to the present invention.
The schematic diagram showing the example.

FIG. 5 is a schematic view showing the action of a magnetic attraction force in the actuator lock mechanism according to the second embodiment of the present invention.

FIG. 6 is a diagram showing a measurement result of a lock torque force of an actuator lock mechanism according to a second embodiment of the present invention.

FIG. 7 is a schematic diagram of a magnetic disk device including an actuator lock mechanism according to the present invention.

FIG. 8 is a schematic view of an actuator lock mechanism in a conventional magnetic disk device.

FIG. 9 is a top view schematically showing a method of fixing a fixed shaft that rotatably holds a carriage arm of a rotary oscillating actuator.

FIG. 10 is a cross-sectional view schematically showing a method of fixing a fixed shaft that rotatably holds a carriage arm of a rotary oscillating actuator.

[Explanation of symbols]

 1 magnetic disk 2 spindle motor 3 magnetic head 4 suspension 5 carriage arm 6 voice coil motor 7 fixed shaft 8 housing 9 cover 11 frame 12 stopper 13 permanent magnet 14 pin made of magnetic material (first magnetic member) 15 permanent magnet Protrusion 16 Magnetic member (second magnetic member)

Claims (3)

[Claims] 1. A first magnetic member provided on an arm having a function of positioning a recording / reproducing head for recording / reproducing information on / from an information recording medium at a predetermined position of the information recording medium, and driving the arm. The first magnetic member is fixed to a predetermined position by a magnetic attraction force due to a leakage magnetic flux of the permanent magnet when the permanent magnet constituting the driving means for moving the arm and the arm are not in operation. An actuator lock mechanism comprising: a second magnetic member provided at a position capable of guiding the leakage magnetic flux of the permanent magnet in a direction in which the magnet is attracted. 2. The actuator lock mechanism according to claim 1, wherein there is a predetermined gap between the first magnetic member and the second magnetic member when the arm is not operating. . 3. An information recording medium, rotating means for holding the information recording medium, a recording / reproducing head for recording / reproducing information on / from the information recording medium, and the recording / reproducing head for a predetermined portion of the information recording medium. An arm having a function of positioning at a position, and a first magnetic member provided on the arm,
The permanent magnet forming the driving means for driving the arm and the first magnetic member are fixed at a predetermined position by the magnetic attraction force due to the leakage flux of the permanent magnet when the arm is not operating. And a second magnetic member provided at a position capable of guiding the leakage magnetic flux of the permanent magnet in a direction of attracting the first magnetic member.