JPS61147767A - Head positioning device - Google Patents

Abstract

PURPOSE:To eliminate a torque ripple by restricting the rotating angle of a rotor coil block 360 deg. or less, and maintaining a magnetic flux applied to the block constant. CONSTITUTION:A rotational shaft 1 is rotatably supported by the first and second bearings 2, 3, the bearing 2 is disposed on an upper tab 4, and the bearing 3 is disposed on a lower tab 5. A rotor coil block 6 is secured through a rotor ring 13 to the shaft 1, and a center yoke 7 is disposed in a hollow portion, an inner magnet block 8 secured to the inner yoke 9 is disposed at the inner peripheral side, and an outer magnet block 10 secured to the casing yoke 11 is disposed on the outer peripheral side. A slit plate 14 is secured to the ring 13, and a light emitting diode 16 opposed thereto is secured to the first board 15, and a phototransistor 18 is secured to the second board 17. Further, the rotary angle of the block 6 is restricted to the 360 deg. or less, and the torque constant can be maintained constant.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a heave positioning device, and more particularly,
The present invention relates to a head positioning device having mold in a positioning motor for moving and positioning the head of an information recording/reproducing device such as a rigid disk device, a floppy disk device, an optical disk device, etc.

[Conventional technology]

Many conventional head positioning devices use a stepping motor as the head positioning motor.
When using a stepping motor, the rotational torque of the stepping motor is transmitted to the head carriage through a power transmission mechanism such as a steel belt, rack and pinion, or lead screw, and the head is moved. As a configuration in which the head is positioned according to the step, it is often seen that the head is moved and positioned in an open loop. Alternatively, some other conventional head positioning devices use a voice coil motor as the head positioning motor, and when a voice coil motor is used, the voice coil Tanabata is directly incorporated into the head hand ridge. The thrust and torque generated by the voice coil motor are directly transmitted to the disk carriage, and the head reads out the servo information recorded on the servo surface of the disk, and the head transfers the servo information to the carriage. As a configuration for moving and positioning, it is common to see cases in which moving and positioning of the front and rear ends is done in a closed loop.

[Problem that the invention seeks to solve]

However, in the conventional technology as described above, when a stepping motor is used as a head positioning motor, the stepping motor is made into an inexpensive and compact unit and rotates step by step, so it is an open loop that is inexpensive and easy to assemble. However, the number of angle divisions and precision of the stepping motor are limited and there is torque ripple, so it is not applicable to head positioning devices that require high information recording track density. Things are difficult;
Even if a heave positioning servo is applied to achieve a high information placement track density, the controllability is poor, making it difficult to achieve high-speed and high-precision head movement positioning, and the lack of responsiveness results in disturbances such as vibration and shock. Another problem is that it is difficult to maintain accurate head positioning when the machine is busy.

However, when a voice coil motor is used as a head positioning motor, the movement is smooth and there is no torque IJ, there is no pull, so high-speed heave movement is possible, head positioning closed loop servo is easy, and there is no vibration. It has excellent responsiveness and can maintain accurate head positioning even in the face of shock and disturbances.Since it is directly incorporated into the h'-5 head carriage, a magnetic shield is required, making the device large and complex. Because the head positioning motor is not assembled into a unit, it is difficult to assemble and inspect, making the head positioning device not only easy to assemble but also very expensive. , there are some problems.

The following problems should be considered with respect to the present invention:
The objective is to provide a head positioning device using a positioning motor that is capable of high-speed movement, has excellent responsiveness, is capable of closed-loop servo control for head positioning, is easy to assemble, is compact, and is inexpensive.

[Means for solving problems]

The head positioning device of the present invention includes a disk as an information recording carrier, a head for performing device reproduction of information on the disk, a head ridge to which the head is fixed, and a head ridge to which the head is moved. In an information recording and reproducing apparatus having a positioning motor for moving and positioning a disc to a predetermined information recording trunk, the positioning motor has a hollow part in the circumferential direction and is equipped with a P-tacoil boot disk wound with an SK coil. , an inner magnet block disposed with a gap on the inner circumference of the rotor coil block, an inner yoke to which the inner magnet pulley is fixed, and an outer circumference of the -partial coil block. ! The outer magnet product is arranged with a gap, the casing yoke to which the outer magnet block is fixed, and the rotor coil block is arranged with an air gap N in the hollow part of the rotor coil block. A center yoke that is connected to the inner yoke and the casing yoke to form a magnetic circuit; a slit plate that is indirectly fixed to the rotor coil block and has a plurality of slits in the circumferential direction; The rotation angle of the rotor coil unit 9 is configured by one or more light emitting means disposed at the same time, and one or more light receiving means for sensing the amount of light generated by the light emitting means passing through the Suriride plate. It is characterized by regulating the angle to less than 360 degrees.

[Effect]

According to the above configuration of the present invention, the rotation angle of the rotor coil is regulated to 360 degrees or less, and the magnetic flux density given to some of the coils is made constant, so that there is no torque ripple. To provide a torque generating means with a constant torque constant, to configure one positioning motor unit by combining it with an optical position detecting means, and to provide a high performance head positioning device using this positioning motor. is possible.

〔Example〕

FIG. 1 is a structural diagram of a positioning motor according to an embodiment of the present invention, in which FIG. FIG. 3 is a plan cross-sectional view of the vicinity of the coil block. In FIG. 1, a rotating shaft 1 is rotatably supported by a first bearing 2 and a second bearing 3;
The second bearing 2 is disposed on the upper cover 4, the second bearing 3 is disposed on the lower cover 5, and a rotor coil block 6 having a hollow portion in the circumferential direction is fixed to the rotating shaft 1 via a rotor ring 13. In the hollow part of the rotor coil block 6, a center yoke 7b'' is disposed with a gap, and on the inner peripheral side of the rotor coil block 6, an inner magnet block 8 fixed to an inner yoke 9 is arranged with a gap. An outer magnet block 10 fixed to a casing yoke 11 is arranged with a gap on the outer peripheral side of the rotor coil block 6, and both the inner magnet block 8 and the outer magnet block 10 are attached in the radial direction. The magnetic poles of the magnetized surfaces facing the center yoke 7 are the same, and as shown in Figure 1-), the center yoke 7, inner yoke 9, and casing yoke 11 are all made of magnetic metal such as pure iron. A first magnetic circuit and an outer magnet 1 that are connected at a part of the circumference by a connect yoke 12 and are composed of an inner magnet 8, a center yoke 7, a connect yoke 12, and an inner yoke 9.
0, the center yoke 7, the connect yoke 12, and the casing yoke 11 provide a uniform air gap magnetic flux density to the rotor coil block 6, and the rotor ring 13 has a plurality of magnetic fluxes arranged in the circumferential direction. A slit plate 14 having slits is fixed, and the slit plate 14
One or more light emitting diodes 16 serving as light emitting means are connected to the casing yoke 11 with a gap in the axial direction relative to the casing yoke 11.
One or more phototransistors 18 serving as light receiving means are fixed on the first substrate 15 disposed on the lower cover 5 with a gap in the axial direction opposite to the light emitting diode 6 with respect to the slit plate 141C. The board 17 of the whistle 2 is arranged in
A slit plate 14 and a phototransistor 1 are fixed on the top.
A window plate 19 having a plurality of slits in the circumferential direction and adjusting the amount of light received and the phase of light received by the phototransistor is disposed between the casing yoke 11 and the upper lid 4.
and the lower cover 5 are connected with a screw 20 to constitute a positioning motor.

FIG. 2 is a general view of the rotor coil shifter 1 in the embodiment of the present invention, in which the rotor coil I2-7 and 21 are constructed by winding coils so as to have a hollow portion in the circumferential direction. Ru.

FIG. 3 is a schematic view of a rotor coil block according to a middle embodiment of the present invention, in which the rotor coil block 31 is wound with coils so as to have a hollow portion in the circumferential direction, and then molded with resin or the like. Constructed by solidification.

FIG. 4 is a general view of a coil case in a partial coil package in still another embodiment of the present invention, in which the coil case 41 is made of a non-magnetic, non-conductive material such as resin. Then, the coil is wound around the coil case 41.

FIG. 5 is a diagram showing an example of magnetization of the inner magnet block in the embodiment of the present invention, in which the ring-shaped tee-shaped inner magnet pull 51 is magnetized and pulled in the radial direction.

FIG. 6 is a diagram showing an example of magnetization of the outer magnet pulley according to the embodiment of the present invention, in which a ring-shaped T-shaped 7-center magnet block 61 is magnetized in the radial direction. The magnetic properties are opposite to the incorporated inner magnet plate G19.

FIG. 7 shows an inner magnet according to another embodiment of the present invention.
, ) is a schematic diagram of the block, which is a ring-shaped tee-shaped inner magnet block 71, which is molded with uneven thickness so that the air gap magnetic flux density is constant, taking into account the permeance due to the length of the magnetic path, and is magnetized in the radial direction. Ru.

FIG. 8 is a schematic diagram of an outer magnet probe according to another embodiment of the present invention, in which an outer magnet block 81 in a ring-shaped Tee shape has an air gap magnetic flux in consideration of permeance due to the magnetic path length. It is molded with uneven thickness so that the density h'' is constant and is magnetized in the radial direction.

The rotor coil block and inner magnet as shown above.
・By using a door block and an outer magnet 9 door block, the coil placed in the gap with the center yoke receives Lorentz force and generates a certain torque when a certain current is passed in one direction.

The relationship between the rotation angle and the generated torque is shown in Figure 9.
rz, if the mechanical rotation angle is limited to the range indicated by the diagonal line in the figure, the generated torque is constant, and the torque constant, which indicates the efficiency of converting current into torque, can be kept constant, which is very A positioning motor with excellent controllability, which can be positioned at any desired position, whose movable parts are coiled and lightweight, and which is capable of high-speed rotation and high-speed response, can be obtained. However, by providing a runaway prevention mechanism such as rubber on the rotor coil block of the connect yoke, it is effective to mechanically limit the rotation range to a portion where the torque constant hZ is constant.

FIG. 10 is a configuration diagram of a slit plate in an embodiment of the present invention. The slit plate 14 has a plurality of slits 101ht formed at a constant angular pitch, and the shaded areas in the figure The slit 101 transmits light.

FIG. 11 is a configuration diagram of a window plate in an embodiment of the present invention, and the window plate 19 has a first window 111-(b)) and a second window 111-(b) at a constant angular pitch. ) is formed, and a first phototransistor 18 serving as a light receiving element is formed for each window.
-IIL) and second phototransistor 18-(b)
are arranged, and it is possible to obtain a position signal output that is approximately proportional to the amount of light transmitted through each window.

In this example, the angular pitch of each of the first window 111-(b)) and the second window 111-(b) is the same as the angular pitch of the slit of the three-metal plate; The second window 111-(1)) has a phase of 9 with respect to VC.
They are placed at positions shifted by 0 degrees, making it possible to output multiphase position signals.

Normally, slit plates and window plates can be produced by etching thin metal plates with high precision and excellent mass production. However, when greater precision is required, glass with good translucency can be used. It is obtained by forming a thin film of metal or the like on a substrate.

FIG. 12 is a diagram showing a timing chart of optical position detection in an embodiment of the present invention, and is an example in which the slit pattern shown in FIG. 10 and the window pattern shown in FIG. 11 are used. In Fig. 12, the amount of light input to the first phototransistor changes in a triangular waveform as shown in A with respect to the rotation angle, and similarly, the amount of light inputted to the second phototransistor changes as shown in B. The phase of B is 90 degrees behind the phase of A, and by comparing the signals of A and B,
A position selection signal such as C and a position selection signal such as D cannot be obtained.By selecting the signals from A and B by C and D, a sawtooth position signal E is obtained and the rotational position is known. I can do things.

Therefore, the position signal of the above-mentioned rotor coil block, which can be positioned at any position, can be obtained from the position signal JK shown in Fig. 12, and the position signal E is output linearly with respect to displacement within one cycle. As a result, closed-loop positioning servo is easy and positioning accuracy can be improved by making the division angle pitch of the slits and windows finer.

FIG. 13 is a block diagram of a head positioning device in an embodiment of the present invention, in which a positioning motor 13 as shown in FIG.
A disk 134 is rotatably arranged on the seven frame 132 via a disk clamp mechanism 135. A plurality of pieces of information are recorded concentrically on the disk 134, and the information recording tracks are arranged on the disk 134. The head 135 is moved to a predetermined information recording track and positioned to record and reproduce information.
Fixed to Hevdo block 157 kehe j do thousand yari?
:) 138 VC fixed-g, head carriage 13
A steel belt 140 whose both ends are supported and fixed to 8 is fixed to a rotating shaft of a positioning motor 131.
39 at a specific part, and the positioning motor 1
By the rotation of 31, the head 135 is moved and positioned to a predetermined information recording track on the disk 134. At this time,
Although the head 135 is moved and positioned by an optical position detection signal from the positioning motor 131, even more accurate track positioning is possible if track position servo information is provided from the disk 134 through the head 135. On the wood flow side, the rotation angle of the positioning motor 131 is 36
The rotation angle is mechanically limited to 0 degrees or less, and if the rotation angle is limited to a region where the torque constant is constant, it is possible to obtain a rotation angle of about 200 to 300 degrees. By determining the diameter, head movement amount, and position detection accuracy, the average head movement time can be reduced to less than half of that when using a stevbing motor, and by obtaining the same number of sawtooth position signals as the number of tracks, the track position WIt High-speed and precise head positioning is possible by knowing the Needless to say, it can be applied to transmission mechanisms or rotary head positioning devices, and although Fig. 13 shows an example of application to a rigid disk device, it can also be applied to floppy disk devices and optical disk devices. It is.

〔Effect of the invention〕

According to the present invention, as described above, the following effects are obtained.

By restricting the rotation angle of the positioning motor to 1360 degrees or less, the rotation direction is uniquely determined by the current direction of the rotor coil block, no current switching mechanism such as a brush is required, and the torque constant does not change depending on the rotation angle.

Since the torque constant of the positioning motor is constant, stable servo control with excellent controllability and responsiveness is possible, and it is easy to cope with high track density.

Since the rotor coil is lightweight and has a simple structure, it is possible to rotate at high speed and respond quickly, and it is also advantageous to reduce costs.

By attaching the structure to the head positioning device as a positioning motor unit, it is possible to inspect the operation of the positioning motor unit alone, and it is easy to handle.The head positioning device is also easier to assemble, and magnetic shielding is also possible. It is not particularly necessary and can be downsized.

By arranging the torque generating means and the optical position detecting means in the same motor unit, space utilization efficiency is high and position signal noise due to external light is not affected.

Since it is composed of ring-shaped parts such as magnets and yokes, it is easy to machine the parts, and it is easy to achieve high processing accuracy, which is advantageous in reducing costs.

By arranging the center yoke in the hollow part of the coil, it is possible to provide a positioning motor with a large torque constant and high magnetic flux utilization efficiency.

Since the torque constant is constant in an angular range close to one revolution and it also has an optical position detection means, it is possible to use a conventional stepping motor to replace the positioning motor of a magnetic head positioning device.

Faster positioning is possible by replacing the positioning motor.

The positioning motor, which has a torque generating means with a constant torque constant and an optical position detecting means, not only facilitates one-position control, but also enables stable speed control using the speed signal obtained from the position signal, making it possible to perform heave positioning. The time for moving and positioning the head in the device is shortened, the time for communicating information with the computer is also shortened, and the arithmetic processing function of the computer is improved.

By molding and solidifying the rotor coil block with resin, it is possible to obtain a lightweight, highly rigid and high mechanical resonance point, and the resin provides insulation between the coils.
Furthermore, it is possible to provide a rotor coil block that is easy to mold and reliable, which also improves the heat dissipation state of the coil and prevents the coil from burning out due to overcurrent.

By holding the rotor coil block in a non-magnetic, non-conductive coil case, a theta coil block with high rigidity and a high mechanical resonance point can be obtained, making coil winding work and handling easy, inexpensive and reliable. It is possible to provide a rotor coil block with various properties.

By adjusting the wall thickness of the inner magnet pro 9, the wall thickness of the center yoke, or the gap length, a positioning motor with a constant magnetic flux density in the gap and a constant torque constant can be achieved with simple assembly.

By adjusting the wall thickness of the outer magnet boot stock, the wall thickness of the center yoke, or the gap length, a positioning motor with a constant magnetic flux density in the gap and a constant torque constant can be achieved with simple assembly.

Since the inner magnet pull is a part of a ring-shaped magnet magnetized in the radial direction, an inexpensive magnet that is easy to mold and handle can be used.

Since the outer magnetic block is magnetized in the radial direction and is a part of the T-ring magnet, it is possible to use an inexpensive magnet Hz that is easy to mold and handle.

The runaway prevention not only limits the mechanical rotation angle so that the torque constant is constant, but also prevents the head positioning device from running out of control, prevents the head positioning device from sagging, and can also be used as a stop for determining the head reference position of the head positioning device. Can be used.

[Brief explanation of drawings]

FIG. 1 is a structural diagram showing an embodiment of the positioning motor in the head positioning device of the present invention, and (α) is a front view (right half sectional view "J + (6) is a plan sectional view. Fig. 3 is an overview diagram showing an embodiment of the rotor coil block according to the present invention. Fig. 3 is an overview diagram showing an embodiment of the rotor coil block according to the invention. An overview diagram showing one embodiment of the coil case of the coil block. Fig. 5 is a diagram showing an example of magnetization of the inner magnet proof in the present invention. Fig. 6 is a diagram showing an example of magnetization of the inner magnet proof in the present invention. A diagram showing an example of magnetization of a block. FIG. 7 is a schematic diagram showing an example of an inner magnet block according to the present invention. FIG. 8 is a diagram showing an example of an outer magnet product according to the present invention. Schematic diagram. Fig. 9 is a diagram showing the relationship between the rotation angle of the positioning motor and the generated torque in the present invention. Fig. 10 is a configuration diagram showing one embodiment of the slit plate in the present invention. Figure 1 is a configuration diagram showing an embodiment of a window plate according to the present invention. Figure 12 is a timing chart diagram showing an embodiment of optical position detection according to the present invention. A configuration diagram showing an embodiment of the head positioning device. 1...Rotary shaft 6...Rotor coil blow J'77...
・Center yoke 8... Inner magnet block 9...
... Inner yoke 10 ... Outer magnet pulley 11 -
... Casing yoke 12 ... Connect yoke 14 ... Slit plate 16 ... Light emitting diode (light emitting means) 18 ...
...Phototransistor (light receiving means) 131...
...Positioning motor 134...Disk 135...Head 138...Head carriage and above

Claims (8)

[Claims] (1) A disk as an information recording carrier, a head for recording and reproducing information on the disk, a head carriage to which the head is fixed, and moving the head carriage to move the head to a predetermined information recording track on the disk. In an information recording/reproducing device having a positioning motor for positioning, the positioning motor may include a rotor coil block around which a coil is wound so as to have a hollow portion in the circumferential direction, and a rotor coil block disposed with a gap around the inner periphery of the rotor coil block. an inner magnet block provided, an inner yoke to which the inner magnet block is fixed, an outer magnet block arranged with a gap around the outer periphery of the rotor coil block, a casing yoke to which the outer magnet block is fixed, and the rotor. A center yoke is disposed with a gap in a hollow part of the coil block and is connected to the inner yoke and the casing yoke at a specific part on the circumference to form a magnetic circuit, and is indirectly fixed to the rotor coil block. A slit plate having a plurality of slits in the circumferential direction, one or more light emitting means disposed with gaps in the axial direction with respect to the slit plate, and an amount of light generated from the light emitting means that passes through the slit plate. 1. A head positioning device comprising one or more light receiving means for sensing the rotation angle of the rotor coil block, and regulating the rotation angle of the rotor coil block to 360 degrees or less. (2) The head positioning device according to claim 1, wherein the rotor coil block is molded and solidified with resin. (3) The head positioning device according to claim 1, wherein the rotor coil block is held by a non-magnetic, non-conductive coil case. (4) The head positioning device according to claim 1, wherein the wall thickness of the inner magnet block, the wall thickness of the center yoke, or the gap length are made non-uniform depending on the circumferential position. (5) The head positioning device according to claim 1, wherein the wall thickness of the outer magnet block, the wall thickness of the center yoke, or the gap length are made non-uniform depending on the circumferential position. (6) The head positioning device according to claim 1, wherein the inner magnet block is a part of a ring-shaped magnet magnetized in the radial direction. (7) The head positioning device according to claim 1, wherein the outer magnet block is a part of a ring-shaped magnet magnetized in the radial direction. (8) A patent claim characterized in that a runaway stopper is provided at a connecting portion between the center yoke, the inner yoke, and the casing yoke, and the rotation angle of the rotor coil block is mechanically regulated to 360 degrees or less. The head positioning device according to item 1.