JP2001289605A - Position detector for moving body and electronic equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a position detector for moving body which can be reduced in size and cost and can be improved in reliability and electronic equipment. SOLUTION: The position detector 500 which detects the position of a moving body 170 with respect to a fixed body 17 is provided with a magnet 510 which is fixed to the moving body 170 and has pairs G of S and P poles and one Hall element 520 which is fixed to the fixed body 199 and detects the magnetism of S poles 511 and N poles 512 when the pairs G of the S and N poles of the magnet 510 pass over the element 520 as the magnet 510 moves together with the moving body 17 when the moving body 170 is moved in a first direction T2 or a second direction T1 opposite to the direction T2, moves.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a moving body position detecting device for detecting the position of a moving body with respect to a fixed body and an electronic apparatus.

[0002]

2. Description of the Related Art A CD-ROM (read only memory using a compact disk) disk, an M-type disk, and the like are used as recording media for various data and programs used in electronic devices such as personal computers.
2. Description of the Related Art Disk-shaped information recording media (hereinafter, referred to as “disks”) such as O (magnetic optical) disks are known. Such a disk is rotated at a predetermined speed after being loaded into the disk drive device, and then the optical pickup reads data or the like recorded on the signal surface.

By the way, when reading data or the like recorded on a disk, a disk drive capable of rotating the disk at a speed higher than a standard speed (1 × speed) for the purpose of improving the reading efficiency. Devices are known. In such a disk drive device, the rotational speed of the disk is reduced to a standard speed (200 to 5).
For example, 4 × speed, 6 × speed, 8
The data reading efficiency is improved by increasing the transfer rate of the reproduced data by using a high-speed rotation such as a double speed,..., 32 times.

[0004] In this type of disk drive device, the optical pickup is movable in the tilt direction so that so-called skew correction can be performed in accordance with the tilt state of the mounted disk. JP-A-11-
Japanese Patent No. 328837 discloses a disk drive device of this type, which includes a skew motor and a plurality of gears for performing skew correction of an optical pickup. The skew motor used is a large cylindrical motor with a so-called rotor and stator,
It is difficult to reduce the size, cost, and power consumption of the drive device.

There is an attempt to correct the skew of such a disk drive device by linearly moving the slider 1000 in the direction of A1 or A2 as shown in FIGS. In FIG. 24, the slider 1
000 has a magnet 1010. The magnet 1010 has an S pole and an N pole.
The poles are arranged alternately in close contact. A circuit board 1020, which is a fixed portion, is arranged so as to face the slider 1000. On this circuit board 1020, two Hall elements 1030 and 1040 are mounted. These Hall elements 1030 and 1040 detect that the slider 1000 moves in the direction of A1 or A2 by detecting the magnetic force of the S pole and the N pole of the magnet 1010 of the slider 1000. In the conventional example of FIG. 25, the slider 1000 similarly has a magnet 1010. The fixed part 1050 is provided with a magnetoresistive element 1060, and a sensor part 1070 of the magnetoresistive element detects magnetic forces of the N pole and the S pole.

[0006]

In the conventional apparatus shown in FIG. 24, two Hall elements 1030 and 1040 are required, which hinders downsizing and cost reduction. In the conventional device shown in FIG. 25, since the magnetoresistive element 1060 is used, the resin portion 1 for holding the sensor portion 1070 is used.
080 is required. In addition, since the gap H between the magnet 1010 and the sensor portion 1070 can be only about 0.1 mm, an adjusting mechanism for adjusting the gap H is required. There is also a problem that the magnetoresistive element 1060 is very expensive compared to the Hall element. Accordingly, it is an object of the present invention to provide a position detecting device and an electronic device for a moving object that can solve the above problems, reduce the size and cost, and increase the reliability.

[0007]

According to a first aspect of the present invention, there is provided a position detecting apparatus for a moving body for detecting a position of the moving body with respect to a fixed body, the apparatus having a set of S pole and N pole fixed to the moving body. A magnet, and the S pole and the N pole of the magnet fixed to the fixed body and moving together with the moving body when the moving body moves in a first direction or a second direction opposite to the first direction. A position detecting device for a moving body, comprising: one Hall element for detecting magnetism of the S pole and the N pole when a set of poles passes.

In the first aspect, the magnet is fixed to the movable body and has a set of an N pole and an S pole. One Hall element is fixed to a fixed body. When the moving body moves in the first direction or the second direction, the magnetism when the pair of the N pole and the S pole of the magnet that moves together with the moving body passes,
The detection is performed by one Hall element. Thus, the position of the moving body, that is, for example, the moving direction and the moving speed of the moving body can be detected by using only one Hall element. Since only one Hall element may be used, the number of components can be reduced, and the cost of the Hall element is considerably lower than that of the magnetoresistive element, so that the cost can be reduced. Since only one Hall element may be used, position detection reliability can be improved as compared with using a plurality of Hall elements.

According to a second aspect of the present invention, in the moving object position detecting device according to the first aspect, the S pole and the N pole are arranged along a moving direction of the moving body. The pole sets are arranged at the same pitch with respect to the adjacent S pole and N pole sets. According to claim 2, a certain pair of N pole and S pole is arranged at the same pitch with respect to a pair of adjacent S pole and N pole. Thus, since the sine wave can be deformed, the waveform can be changed according to the moving direction of the moving body.

According to a third aspect of the present invention, in the moving object position detecting device according to the first aspect, the width W1 and the pitch W of the S pole are W1 = 1 / 8W to 1 / 3W. Claim 3
Then, if the width W1 of the set of the S pole and the N pole is smaller than 1 / 8W, the waveform is distorted. If it is larger than 1 / 3W, it will be close to a sine wave, and there will be no difference in waveform between forward rotation and inversion.

According to a fourth aspect of the present invention, in the moving object position detecting device according to the first aspect, the pair of the S pole and the N pole includes:
A notch portion larger than the size of the Hall element is formed. According to the fourth aspect, a notch portion larger than the size of the Hall element is formed in the set of the N pole and the S pole to provide a portion where the Hall element is not affected by magnetic flux while the magnet is integrated. be able to.

According to a fifth aspect of the present invention, in the moving object position detecting device according to the first aspect, the notch has a square shape,
Either a curved shape or a triangular shape.

According to a sixth aspect of the present invention, in the position detecting apparatus for a moving body according to the first aspect, the output waveform of the Hall element has a saw-tooth shape, and the time of the rising portion and the time of the falling portion of the output waveform are different. And a processing unit that determines whether the direction in which the moving body moves is the first direction or the second direction, and obtains the moving speed of the moving body. According to claim 6, the processing unit can determine whether the moving body is moving in the first direction or the second direction and obtain the moving speed based on the output waveform of the Hall element.

According to a seventh aspect of the present invention, there is provided an electronic apparatus having a moving body position detecting device for detecting a position of the moving body with respect to the fixed body, wherein the position detecting device is fixed to the moving body, and has an S pole and an N pole. And a magnet fixed to the fixed body, the magnet moving together with the moving body when the moving body moves in a first direction or a second direction opposite to the first direction. An electronic apparatus including a moving object position detecting device, comprising: one Hall element for detecting magnetism of the S pole and the N pole when a set of the S pole and the N pole passes.

According to the present invention, the magnet is fixed to the movable body and has a set of an N pole and an S pole. One Hall element is fixed to a fixed body. When the moving body moves in the first direction or the second direction, the magnetism when the pair of the N pole and the S pole of the magnet that moves together with the moving body passes,
The detection is performed by one Hall element. Thus, the position of the moving body, that is, for example, the moving direction and the moving speed of the moving body can be detected by using only one Hall element. Since only one Hall element may be used, the number of components can be reduced, and the cost of the Hall element is considerably lower than that of the magnetoresistive element, so that the cost can be reduced. Since only one Hall element may be used, position detection reliability can be improved as compared with using a plurality of Hall elements.

According to an eighth aspect of the present invention, in the electronic apparatus having the moving body position detecting device according to the seventh aspect, the S pole and the N pole are arranged along a moving direction of the moving body. The pair of the S pole and the N pole is arranged at the same pitch with respect to the adjacent pair of the S pole and the N pole. According to claim 8, a set of a certain N pole and S pole is arranged at the same pitch with respect to a set of an adjacent S pole and N pole. Thus, since the sine wave can be deformed, the waveform can be changed according to the moving direction of the moving body.

According to a ninth aspect of the present invention, in the electronic device having the moving body position detecting device according to the seventh aspect, the width W1 and the pitch W of the S pole are W1 = 1 / 8W to 1 / 3W.
It is. In the ninth aspect, the width W1 of the pair of the S pole and the N pole is 1
If it is smaller than / 8 W, the waveform will be distorted. 1/3
If it is larger than W, it will be close to a sine wave, and there will be no difference in the waveform between normal rotation and inversion.

According to a tenth aspect of the present invention, there is provided an electronic apparatus having the moving object position detecting device according to the seventh aspect, wherein
A notch larger than the size of the Hall element is formed in the pair of the pole and the N pole. According to the tenth aspect, a notch portion larger than the size of the Hall element is formed in the set of the N pole and the S pole to provide a portion where the Hall element is not affected by magnetic flux while the magnet is integrated. be able to.

According to an eleventh aspect of the present invention, in the electronic device having the moving body position detecting device according to the seventh aspect, the notch has any one of a square shape, a curved shape, and a triangular shape.

According to a twelfth aspect of the present invention, in the electronic apparatus having the moving body position detecting device according to the seventh aspect, the output waveform of the Hall element is saw-toothed, and the time of the rising portion of the output waveform is reduced. A processing unit that determines whether the moving body moves in the first direction or the second direction by comparing the time of the descending portion and obtains the moving speed of the moving body. In the twelfth aspect, the processing unit determines that the moving direction of the moving body is the first based on the output waveform of the Hall element.
It is possible to determine whether it is the direction or the second direction and obtain the moving speed.

According to a thirteenth aspect of the present invention, there is provided a position detecting device for a moving body for detecting a position of the moving body with respect to a fixed body, wherein the magnet fixed to the fixed body and having a pair of S pole and N pole; A Hall element that detects the magnetism of the S pole and the N pole when the moving body moves in a first direction or a second direction opposite to the first direction;
A position detecting device for a moving object, comprising: In claim 13, the magnet is fixed to the fixed body,
It has a pair of S pole and N pole. One Hall element is fixed to the moving body. When the moving body moves in the first direction or the second direction, one Hall element detects the S pole and N pole magnetism on the fixed body side. Thus, the position of the moving body, that is, for example, the moving direction and the moving speed of the moving body can be detected by using only one Hall element. Since only one Hall element may be used, the number of components can be reduced, and the cost of the Hall element is considerably lower than that of the magnetoresistive element, so that the cost can be reduced. Since only one Hall element may be used, position detection reliability can be improved as compared with using a plurality of Hall elements.

According to a fourteenth aspect of the present invention, in the moving object position detecting device according to the thirteenth aspect, the S pole and the N pole are arranged along a moving direction of the moving body. The pole sets are arranged at the same pitch with respect to the adjacent S pole and N pole sets.

[0023]

Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings. Note that the embodiments described below are preferred specific examples of the present invention,
Although various technically preferable limits are given, the scope of the present invention is not limited to these modes unless otherwise specified in the following description.

FIG. 1 shows a drive device for an information recording medium as an example of the electronic apparatus of the present invention. This drive device is a device for driving an optical disk which is an example of a disk-shaped information recording medium. Drive device 100 of FIG.
For example, a disc 90 such as an optical disc loaded in a CD-DA (Compact Disc Digit)
AL-AUDIO), CD-ROM (CD-ROM (read only memory using CD)), DVD
(DIGITAL VERSATILE DISC / D
A disk called "IGITAL VIDEO DISC" can be considered. Of course, the present invention can be applied to a drive device corresponding to another type of disk.

The disk 90 shown in FIG.
And a constant linear velocity (CLV) or a constant angular velocity (CA) by the spindle motor 6 during the reproducing operation.
V). Then, data recorded in a pit form on the disk 90 is read by the optical pickup 1 as an optical unit.

The laser light from the laser diode 4 in the optical pickup 1 is applied to the recording surface of the disk 90 from the objective lens 2 via an optical system (not shown).
The objective lens 2 is held by a biaxial mechanism 3 so as to be movable in a tracking direction and a focus direction. Tracking and focus control of laser light are performed by the operation of the biaxial mechanism 3.

The reflected light information of the laser light from the disk 90 is detected by the detector 5 from the objective lens 2 via an optical system (not shown), and the detector 5 supplies an electric signal corresponding to the amount of received light to the RF amplifier 21.

The RF amplifier 21 generates a necessary signal based on a signal from the detector 5, and generates, for example, an RF signal as reproduction data, a focus error signal FE for servo control, a tracking error signal TE, and the like.

Various signals generated by the RF amplifier 21 are:
It is supplied to the binarization circuit 25 and the servo processor 31.
The reproduced RF signal from the RF amplifier 21 is converted to a binarization circuit 25.
Supplied to The focus error signal FE, the tracking error signal TE, and the like are supplied to the servo processor 31.

The reproduced RF signal obtained by the RF amplifier 21 is binarized by a binarization circuit 25, so that, for example, EFM
The signal is supplied to the decoder 26 as a signal (8-14 modulated signal; when the disk 90 is a CD disk) or an EFM + signal (8-16 modulated signal; when the disk 90 is a DVD disk). Decoder 26
Performs EFM demodulation, etc., and if necessary,
The information read from the disc 90 by performing OM decoding or the like is reproduced.

The servo processor 31 includes the RF amplifier 21
From the focus error signal FE, the tracking error signal TE, and the spindle error signal SPE from the decoder 26 or the system controller 30, various servo drive signals for focus, tracking, sled, and spindle are generated to execute the servo operation.

A focus drive signal and a tracking drive signal are generated in accordance with the focus error signal FE and the tracking error signal TE, and the two-axis driver 18
To supply. The two-axis driver 18 drives the two-axis mechanism 3 in the optical pickup 1. Thereby, a tracking servo loop and a focus servo loop by the optical pickup 1, the RF amplifier 21, the servo processor 31, and the two-axis driver 18 are formed.

The servo processor 31 sends a spindle error signal SPE to the spindle motor driver 19.
Is supplied, and the CAV rotation or CLV rotation of the spindle motor 6 is executed.

The rotation speed of the spindle motor can be set to a high speed such as a double speed, a quadruple speed, and an octuple speed when the normal speed is set to a normal speed.

The FG 27 generates a frequency pulse (FG pulse) corresponding to the rotation speed of the spindle motor 6 and supplies it to the servo processor 31. For example, six FG pulses are generated for one rotation of the spindle motor 6.

The sled mechanism 8 shown in FIG. 1 indicates the parts such as the main shaft 8a, the sled motor 8b, the sled transmission gears 8c, 8d and 8e shown in FIG. By driving the sled motor 8b of the sled mechanism 8 of FIG. 2 according to the sled drive signal by the sled driver 17 of FIG. 1, the optical pickup 1 performs an appropriate sliding movement in the A direction.

The system controller 30 receives the movement information TKC from the thread sensor 10 and the optical pickup 1
The speed signal SLv of the optical pickup 1 is generated and supplied to the servo processor 31. At the same time, rough position information of the optical pickup 1 obtained from the movement information TKC is supplied to the servo processor 31.

The servo processor 31 generates a thread error signal from the speed signal SLv from the system controller 30, the tracking error signal TE from the RF amplifier 21, and the like, and generates a thread error signal based on access execution control from the system controller 30. A drive signal is generated and supplied to the thread driver 17. The sled driver 17 drives the sled mechanism 8 according to the sled drive signal to control the feed of the optical pickup 1.

The laser diode 4 of the optical pickup 1 shown in FIG. The servo processor 31 generates a laser drive signal for performing laser emission of the optical pickup 1 at the time of reproduction or the like based on an instruction from the system controller 30, and supplies the laser drive signal to the laser driver 20.

Various operations such as servo and decoding as described above are controlled by a system controller 30 formed by a microcomputer. For example, operations such as playback start, end, and track access (seek)
This is realized by the system controller 30 controlling the operations of the servo processor 31 and the optical pickup 1.

Next, referring to FIG. 2, a description will be given of the structure of a drive section (so-called mechanical deck section) for playing back a disc of the information recording medium drive device 100. FIG. On the sub-chassis main body 11 of the mechanical deck, various mechanisms necessary for driving and reproducing the disc are provided. The loaded disk 90 is mounted on the turntable 7, and the disk 90 is rotated by the rotation of the turntable 7 by the spindle motor 6.

The optical pickup has an optical system and a laser light source for irradiating the rotating disk 90 with laser light and extracting information from the reflected light. In the optical pickup 1, the objective lens 2 serves as an output end of the laser beam, and faces the disk 90 as shown in the figure.

The optical pickup 1 is slidable in the disk radial direction (A direction) by the sled mechanism 8 shown in FIG. Therefore, a main shaft 8a and a sub shaft 12 are provided on both sides of the optical pickup 1.
The main shaft 8 is attached to the holder 8g of the optical pickup 1.
The optical pickup 1 can move in the shaft direction (direction A) while being supported by the main shaft 8a and the sub shaft 12 because the sub shaft 12 passes through the holder portion 12g on the opposite side. .

As a mechanism for moving the optical pickup 1 on the shaft, a thread motor 8b and thread transmission gears 8c, 8d, 8e are provided, and a rack gear 8f is mounted near the holder 8g of the optical pickup 1. ing. When the thread motor 8b is rotationally driven, its rotational force is transmitted to the thread transmission gears 8c, 8d,
8e. The thread transmission gear 8e is a rack gear 8f
The transmitted rotational force moves the optical pickup 1 in the shaft direction. Therefore, the optical pickup 1 is moved in the shaft direction, that is, in the disk radial direction by the forward / reverse rotation of the sled motor 8b.

The optical pickup 1 is movable in the tilt direction so as to perform so-called skew correction according to the tilt state of the loaded disk. For this reason, one end of the main shaft 8a is held by the sub-chassis main body 11 by the holding portion 8h, and the other end is in a cam groove 15 formed in the rotating member 14 for skew.

In FIG. 2, a skew adjustment unit 150 is mounted on the drive device 100. The skew adjustment unit 150 adjusts the skew of the optical pickup 1 as an optical reproducing unit in the Z direction by moving the main shaft 8a as a feed shaft and a support member in the Z direction. Thereby, the optical pickup 1 is moved around the sub-shaft 12 in the Z direction, which is the tilt direction, in accordance with the tilt state of the disk 90 loaded on the turntable 7 of the spindle motor 6 to perform the skew correction. It can be carried out.

The skew adjusting section 150 will be described in detail below. As shown in FIG. 3, the skew adjustment unit 150 roughly includes the rotating body 14, the moving body 170, the shape memory alloy member 200 for moving operation, and the like.
As shown in FIGS. 2 and 3, the skew adjusting unit 150
It is provided on the basis of the side plate 199 which is a fixing portion.
The side plate 199 is integrally fixed to the sub-chassis 11 in FIG. 2 and is provided upright on the rear side of the rotating body 14. The side plate 199 is preferably made of an electrical insulator such as plastic.

In FIGS. 3 to 5, the rotating body 14 is a disc, and rotates around the central axis 14A in the first rotation direction R1 or the second rotation direction R2.
The rotating body 14 is desirably made of an insulating material such as plastic. The rotating body 14 has a cam groove 15. The cam groove 15 is formed so as to be eccentric about the center axis 14A. The end of the main shaft 8a is inserted into the cam groove 15. In addition, the rotating body 14 is retained by a retaining ring. The shape of the cam groove 15 is shown in FIG.
And an arc shape as shown in FIG. The main shaft 8a is located at a position directly below the central axis 14A in FIG. 3, that is, at a position directly below along the Z direction, and when the rotating body 14 rotates in the first rotation direction R1 or the second rotation direction R2, The main shaft 8 a moves up and down along the cam groove 15 in the Z direction, that is, in the radial direction of the rotating body 14, depending on the eccentric state of the cam groove 15.

A gear 14B is provided on the rear side of the rotating body 14 in FIG.
Has been fixed. As shown in FIG. 3 and FIG.
Is set smaller than the diameter of the rotating body 14. As shown in FIGS. 3 and 8, the rotating body 14 and the side plate 199
Between them, a torsion coil spring 260 as an urging member is set. One end 2 of this torsion coil spring 260
61 is fixed to the rotating body 14 and the gear 14B via a pin 262. However, the torsion coil spring 26
The other end 263 of the “0” is fixed to the side plate 199 via a pin 264. The torsion coil spring 260 connects the rotating body 14 and the gear 14B to the first rotation direction R of FIG.
It is biased to one side.

Next, the moving body 170 and the shape memory alloy member 200 for moving operation in FIG. 3 will be described. Moving object 1
70 is preferably made of a conductor, for example. The moving body 170 is a plate-shaped member, and is arranged in parallel with the side plate 199 as shown in FIGS. 3 and 5, and the moving body 170 is moved along the guide 171 of FIG.
It is provided so as to be movable in two directions. Moving object 1
A rack 173 is provided above 70. The rack 173 is engaged with the gear 14B of the rotating body 14.

Below the moving body 170, for example, a concave portion 174 is provided. The portions 174 are formed, for example, at equal intervals along the T1 direction. The portions 174 are desirably formed at a pitch corresponding to the pitch at which the racks 173 are formed. A guide groove 176 is formed in an intermediate portion of the moving body 170 along the T1 direction. A large hole 177 is formed at one end of the guide groove 176.
Are formed. A boss 18 is provided at one end of the moving body 170.
0 is provided. This boss 180 and the central boss 1
Between 81, a shape memory alloy member 200 for moving operation is attached. FIG. 9 shows an example of a cross-sectional structure taken along line FF in FIG.

The boss 184 in FIG. 9 is directly fixed to the moving body 170. The boss 180 is screwed and fixed to the boss 184. One end 201 of the shape memory alloy member 200 is located between the bosses 180 and 184 in FIG.
It is fixed by press fitting as shown in FIG. The other end 202 of the shape memory alloy member 200 is connected to the boss 1 as shown in FIG.
Also between 81 and another boss 185 is fixed by press fitting. The boss 185 is the guide groove 1 of the moving body 170.
It just goes to 76. However, the shaft portion 181A of the boss 181 is screwed and fixed to the side plate 199.
Therefore, the bosses 181, 185 and the shape memory alloy member 200
Is fixed to the side plate 199 without moving its position. Another boss 187 also has a side plate 199
3, but passes through the guide groove 176 of the moving body 170 as shown in FIG.
70 is in electrical contact.

The bosses 180 and 185 in FIG. 9 are made of an electrical insulator such as plastic. On the other hand, the boss 184, the boss 181 and the boss 187 are made of a conductive material. As the conductive material, a metal or a resin coated with a metal can be used. As a result, the energization control unit 219 in FIG. 3 outputs the operating shape memory alloy member 2 in the manner shown in FIG.
00 can be energized. First, the energizing section 200
9 passes through the boss 181, the shape memory alloy member 200, the boss 184, and the moving body 170 in FIG.
Then, the process returns to the energization control unit 219 in FIG.

Thus, when the shape memory alloy member 200 for moving operation is energized, the shape memory alloy member 200 exerts a tensile force. The shape memory alloy member 200 is shown in FIG.
When the pulling force is exerted at
Move in the direction. An example of the movement is shown in FIG. As described above, when the moving body 170 moves in the T1 direction,
The rotating body 14 can rotate against the urging force of the torsion coil spring 260 along the second rotation direction R2.
Thereby, the main shaft 8a is lifted in the Z direction along the cam groove 15, so that the main shaft 8a
2, that is, skew correction in the Z direction of the optical pickup 1 in FIG. 2 can be performed. By changing the amount of energization from the energization control unit 200 to the shape memory alloy member 200 for the moving operation, the degree of the tensile force of the shape memory alloy member 200 can be adjusted, so that the second rotation direction R2 of the rotating body 14 can be adjusted. , The skew correction amount of the main shaft 8a in the Z direction can be adjusted.

Next, a boss 330 is provided on the side plate 199 as shown in FIG. The boss 330 fixes one end of the lock member 340. Lock member 340
Are mechanically engaged with the portion 174 of the moving body 170. The lock member 340 is formed by the shape memory alloy member 400 for locking operation along the direction E in the region 1.
74. One end of the shape memory alloy member 400 is fixed to the lock member 340, and the other end is fixed to the boss 350. The energization method for the shape memory alloy member 400 is as follows. The energization control unit 219 includes the boss 330 and the boss 35
0, and the shape memory alloy member 400
Is supplied with current through the bosses 350 and 330. When an electric current passes through the shape memory alloy member 400, a tensile force is exerted, so that the lock member 340 retreats from the portion 174 around the boss 330 along the direction E and becomes the state shown in FIG. The lock member 340 has a function of positioning and fixing the moving body 170 in the direction of T1 or T2 since the lock member 340 is engaged with the corresponding portion 174.

The shape memory alloy member 2 for the moving operation described above
00 and the following shape memory alloy member 400 for lock operation can be employed. The shape memory alloy member 200 and the shape memory alloy member 400 exhibit superelasticity by being energized together and exhibit a function as a tension coil spring. The shape memory alloy member 200 and the shape memory alloy member 400 are made of, for example, Ti (titanium), Ni
It is an alloy member made of (nickel) and Cu (copper).
However, the present invention is not limited to this.
0,400 may be an alloy of Ni and Ti.

Next, an example of the operation of the skew adjusting unit 150 in the above-described information recording medium drive device 100 will be described. For example, in FIG. 3, an example will be described in which the skew correction of the main shaft 8a in the Z direction is performed by changing the state of the moving body 170, for example, to the state of the moving body 170 as shown in FIG. Moving object 1 in FIG.
The locking member 340 is engaged with the portion 174 of the 70, and in this state, the moving body 170 is fixed in the T1 direction and the T2 direction.

FIG. 11 shows the power supply control unit 219 in FIG.
Shows an example of a time chart in which a drive signal S1 is supplied to a shape memory alloy member 200 for a moving operation, and an energization control unit 219 supplies an unlock signal S2 to a shape memory alloy member 400 for a lock operation. I have. First, when the energization control unit 219 of FIG. 3 supplies a current that is the lock release signal S2 to the shape memory alloy member 400, the lock member 34
0 retreats from the part 174 along the E direction. Thus, the moving body 170 can move in the direction of T1 or T2.

Next, when the energization control unit 219 of FIG. 3 supplies the drive signal S1 shown in FIG. 11 to the shape memory alloy member 200 for the moving operation, the shape memory alloy member 200 exerts a pulling force to move. The body 170 moves in the T1 direction.
Accordingly, the rotating body 14 rotates against the biasing force of the torsion coil spring 260 along the second rotation direction R2.
Therefore, since the main shaft 8a is guided along the cam groove 15, the main shaft 8a rises in the Z direction so as to approach the central axis 14A.
The shape memory alloy member 200 exerts a tensile force in accordance with the magnitude of the current which is the drive signal S1, so that the moving amount of the moving body 170 in the T1 direction is
It may be adjusted according to the skew correction amount in the direction.
Thereafter, by turning off the lock release signal S2 shown in FIG. 11, the tensile force of the shape memory alloy member 400 shown in FIG. 3 is released, and the lock member 340 fits into the corresponding position 174 as shown in FIG. Put in. With this, moving body 1
The movement of the rotating body 14 in the T1 direction or the T2 direction can be stopped, and the rotation of the rotating body 14 can also be prevented.

As described above, according to the present invention, the skew of the main shaft 8a can be adjusted by using the shape memory alloy member, so that the conventional electromagnetic cylindrical large motor can be used. In comparison, drive device 1
00 can be significantly reduced in size, and cost and power consumption can be reduced. From this, it is possible to secure the thinness and high reliability of the drive device 100. What has been described above is an operation example of the skew adjustment unit 150 in FIG.

Next, a description will be given of a position detecting device of the moving body for detecting the position information when the moving body 170 moves with respect to the fixed portion or the side plate 199 which is the fixed body, that is, the moving direction and the moving speed shown in FIG. I do. FIG. 12 shows a configuration example of a moving object position detection device 500. This moving object position detecting device 500 includes magnets 510 and 1
It has two Hall elements 520. Magnet 510
Has at least one set G of the S pole 511 and the N pole 512. Set G of S pole and N pole of magnet 510
Are fixed to the inner surface 170D of the moving body 170 as a slider. One Hall element 520 is fixed to side plate 199. One Hall element 520 faces magnet 510 at an interval.

FIG. 13 is a diagram viewed from the AB side in FIG. 12, and shows the magnet 510 and the moving body 170. The set G of the S pole and the N pole of the magnet 510 is arranged at a predetermined pitch W along the moving direction of the moving body 170. The pitch W has the following relationship with the width W1 of the S pole 511. W1 = 1 / 8W to 1 / 3W If, for example, the width W1 of the S pole 511 is smaller than 1 / 8W, the waveform will be distorted. If the width W1 is larger than 1 / 3W, the waveform becomes close to a sine wave, and there is no difference in the waveform between forward rotation and inversion.

FIG. 14 shows an example of the output waveform SW1 generated by the Hall element 520 when the moving body 170 in FIG. 12 moves in the forward direction T2. FIG. 15 shows an example of an output waveform SW generated by the Hall element 520 when the moving body 170 moves in the opposite direction T1.

Next, the detection of the moving direction of the moving body 170 will be described with reference to FIGS. FIG.
(A) shows the output waveform SW of the detection output S when the moving body 170 in FIG. 12 moves in the opposite direction T1. FIG. 17B shows an output waveform SW1 of the detection signal S when the moving body 170 in FIG. 12 moves in the forward direction T2. As described above, the output waveforms SW, S
W1 has a substantially sawtooth shape, and the output waveforms SW and SW1 have inverted waveforms.

The output waveform SW shown in FIG. 16A has a rising portion 980 of the output waveform SW which is different from the exact shape of the sine waveform.
And the descending portion 981 has a different inclination. Similarly,
Also in the output waveform SW1 of FIG.
82 and the descending portion 983 have different inclination angles. FIG.
In (A), the time when the rising portion 980 crosses the reference voltage v0 is defined as t1, and the time when the maximum value is reached is defined as t2. The time when the falling part 981 crosses the reference voltage v0 is defined as t3. In FIG. 16B, times t1, t2, and t3 are set in the same manner. Such time setting processing is performed by the signal processing unit 300 in FIG. The reference voltage v0 is a value obtained by adding the maximum value MAX and the minimum value MIN and dividing by 2 as shown in FIGS.

FIG. 17 shows such times t1, t2, t
After setting 3, the moving body 120 in FIG.
Moving in the opposite direction T1 as shown in FIG.
It is a flowchart for judging whether it is moving in the forward direction T2 as shown in FIG. In step ST1 of FIG. 17, the value of the output waveform SW of FIG. 16A is converted from analog to digital, and when the digital value exceeds the reference voltage v0, the value of the output waveform SW is changed to the reference voltage v0. Is assumed to have crossed, and the time is set to t1. Next, step ST2
In the above, it is determined whether or not the value of the output waveform SW has reached the maximum value MAX. If the value has reached the maximum value, the time is set to t2.

Next, in step ST3, the output waveform S
It is determined whether or not the value of W has become equal to or lower than the reference voltage v0. If the value has become equal to or lower than the reference voltage v0, the time is set to t3. In step ST4, the computer 411 in FIG. 18 compares the value of (t2-t1) with the value of (t3-t2). The result of this comparison (t2-t1) is (t3-
If it is larger than t2), as shown in FIG. 16A, the computer 411 in FIG. 18 can consider that the moving object 170 is moving along the opposite direction T1. Otherwise, if (t3-t2) is greater than (t2-t1), the computer 411 of FIG.
It can be considered that the moving body 170 is moving in the forward direction T2 as shown in FIG.

As described above, FIGS. 16A and 16B
Is determined based on the flowchart of FIG. 17, the computer 411 of FIG. 18 can surely know whether the rotating body is rotating forward or inverting. In addition, by knowing the values of the times t1, t2, and t3, the moving speed of the moving body 170 can be known.

The Hall element 5 shown in FIGS. 18 and 19
The 20 detection outputs S are sent to the signal processing unit 300. The signal processing unit 300 receives the detection output S,
The computer 411 is a mobile object 170 shown in FIG.
It is determined whether it is moving in the forward direction T2 or the opposite direction T1 which is the second direction, and the N pole and the S pole of the magnet 510 passing through the Hall element 520 are determined.
By counting the number of poles, the moving amount of the moving body 170 in the moving direction is detected.

One Hall element 520 shown in FIG. 12 is a magnetoelectric conversion element which converts the magnetic quantity of the N pole and S pole of the magnet 130 into an electric quantity (Hall output).
System, GaAs system, InSb system and the like. As the magnet 510 in FIG. 12, for example, a magnet in which a magnetic substance is included in rubber, a magnet in which a magnetic substance is included in plastic, or a magnet such as a sintered magnet is used. Can be.

In the circuit example shown in FIG.
Are mounted on the substrate 150C. One Hall element 520 has a sensor unit 425 and an amplification unit 410. When the sensor unit 425 detects the magnetism of the N and S poles of the magnet, the sensor unit 425 converts the magnetism into a magnetic-electric signal and converts the signal to an amplifying unit 41.
Send to 0 input side. The Hall element 520 has a reference voltage Vc
c, the voltage output unit Vout, and the ground GND.

Next, another embodiment of the present invention will be described with reference to FIGS. 20 to FIG.
FIG. 20 shows the moving body 170 and the magnet 510 in the same direction as FIG. The position of the Hall element 520 on the fixed body side is shown by a broken line for reference. S pole 511 of magnet 510 and N
A rectangular or square cutout 770 is formed between the set G of the poles 512 and the adjacent set G, for example.

In the embodiment shown in FIG. 21, a notch portion 780 is similarly formed between a set G of the S pole and the N pole and an adjacent set G. The notch 780 is a curved notch such as an arc. In the embodiment of FIG. 22, a triangular cutout portion 790 is formed between adjacent sets G, G. Notches 770, 78 in FIGS.
The notched area of 0,790 is set to be larger than the area of the Hall element 520 on the fixed body side indicated by the broken line for reference. As shown in FIG. 20 to FIG.
By providing the Hall element 10, a portion where the Hall element is not affected by the magnetic flux can be provided while the magnet is integrated.

FIG. 23 shows still another embodiment of the present invention. In FIG. 23, one Hall element 520 is provided on the moving body 170 side. On the other hand, the side plate 199 which is a fixed body is provided with the magnet 5 shown in FIG.
A magnet 1510 similar to 10 is provided. The S pole 511 and the N pole 512 of the magnet 510 form a set G, and the pitch between the adjacent set G and the set G is W, for example, the width of the S pole 511 is W1. This width W1 and pitch W
Is the same as the case shown in FIGS. In the example of FIG. 23, when the moving body 170 moves in the forward direction T2 or the opposite direction T1, the Hall element 520 moves with respect to each set of the magnets 1510. Thus, output waveforms SW1 and SW similar to those in FIG. 16 can be output. The movement direction can be determined from the change in the waveform, and the movement speed can be detected from the cycle of the waveform.

The electronic apparatus having the moving object position detecting device according to the present invention may be used not only for a skew adjusting mechanism in a drive device for an information recording medium, but also for a zoom mechanism and a focusing mechanism of a lens such as a video camera and a digital still camera. For example, it can be used anywhere as long as the position of a moving body that moves linearly is detected.

In the embodiment of the present invention, since only one Hall element is used, the size and cost can be reduced as compared with the conventional example using two Hall elements. Further, since only one Hall element may be used, the cost can be reduced as compared with a conventionally used magnetoresistive element. The Hall element itself is much smaller than the magnetoresistive element, and the size of the device can be reduced. Since only one Hall element may be used, operation reliability can be improved as compared with using two Hall elements. When two Hall elements are used, it is necessary to make the characteristics of the two Hall elements the same, so that an increase in cost is inevitable. However, in this regard, in the present invention, one Hall element may be used. Therefore, cost can be reduced.

[0077]

As described above, according to the present invention,
The size and cost can be reduced, and the reliability can be improved.

[Brief description of the drawings]

FIG. 1 is a diagram showing a drive device for an information recording medium as a preferred embodiment of an electronic apparatus according to the present invention.

FIG. 2 is a perspective view of a drive device for the information recording medium of FIG. 1;

FIG. 3 is a diagram illustrating a skew adjustment unit.

FIG. 4 is a diagram illustrating an example of a state in which a moving body of a skew adjustment unit has moved.

FIG. 5 is a perspective view of a skew adjustment unit.

FIG. 6 is a front view showing a rotating body of a skew adjustment unit.

FIG. 7 is a perspective view of a rotating body.

FIG. 8 is a perspective view showing a rotating body and side plates.

FIG. 9 is a cross-sectional view showing a moving body, a fixed body, and the like.

FIG. 10 is a sectional view of a fixed portion of the moving body.

FIG. 11 is a diagram showing an example of an operation drive signal and an unlock signal.

FIG. 12 is a diagram showing a preferred embodiment of a moving object position detecting device according to the present invention.

FIG. 13 is a diagram viewed from the AB direction in FIG. 12;

FIG. 14 is a diagram showing an output waveform when the moving body moves in the forward direction.

FIG. 15 is a diagram showing an output waveform when the moving body moves in the opposite direction.

FIG. 16 is a diagram showing output waveforms in the forward direction and the opposite direction arranged side by side.

FIG. 17 is a flowchart for judging a moving direction and the like of a moving object based on an output waveform.

FIG. 18 is a diagram illustrating a Hall element, a signal processing unit, and the like.

FIG. 19 is a diagram showing a structural example of a Hall element.

FIG. 20 is a diagram showing another embodiment of the present invention.

FIG. 21 is a view showing still another embodiment of the present invention.

FIG. 22 is a view showing still another embodiment of the present invention.

FIG. 23 is a diagram showing another embodiment of the moving object position detecting device.

FIG. 24 is a diagram showing a magnet and two Hall elements of a conventional slider.

FIG. 25 is a diagram showing a magnet and a magnetoresistive element of a conventional slider.

[Explanation of symbols]

100: Drive device for information recording medium (electronic device), 170: Moving body, 199: Side plate (fixed body), 500: Position detecting device for moving body, 510 ...
・ Magnet, 511 ・ ・ ・ S pole, 512 ・ ・ ・ N pole,
520: Hall element, 770: Notch, G
..Set of S pole and N pole, T1... Opposite direction (second direction), T2... Forward direction (first direction)

 ──────────────────────────────────────────────────続 き Continuing on the front page F term (reference) 2F034 AA13 EA04 EA05 EA14 EA21 2F063 AA00 AA02 BA30 BD15 CA34 DA01 DA05 DD02 EA02 GA52 GA65 GA72 LA12 LA19 2F077 AA37 AA43 CC02 NN05 NN07 NN17 PP12 QQ13 TT55 V02 KK25

Claims (14)

[Claims] 1. A position detecting device for a moving body for detecting a position of the moving body with respect to a fixed body, wherein the magnet is fixed to the moving body and has a set of an S pole and an N pole; When the moving body moves in a first direction or a second direction opposite to the first direction, the S pole when the set of the S pole and the N pole of the magnet that moves together with the moving body passes therethrough And a Hall element for detecting N-pole magnetism. 2. The S pole and the N pole are arranged along a moving direction of the moving body, and a pair of the S pole and the N pole is the same as an adjacent pair of the S pole and the N pole. The position detecting device for a moving body according to claim 1, wherein the position detecting device is arranged at a pitch. 3. The moving object position detecting device according to claim 1, wherein the width W1 of the S pole and the pitch W are W1 = 1 / 8W to 1 / 3W. 4. The mobile object position detecting device according to claim 1, wherein a cutout portion larger than the size of the Hall element is formed in the set of the S pole and the N pole. 5. The moving object position detecting device according to claim 1, wherein the notch has any one of a square shape, a curved shape, and a triangular shape. 6. The output waveform of the Hall element has a saw-tooth shape, and by comparing the time of the rising portion and the time of the falling portion of the output waveform, the moving direction of the moving body is in the first direction. The position detection device for a moving body according to claim 1, further comprising a processing unit that determines whether the moving body is located in the second direction and obtains a moving speed of the moving body. 7. An electronic apparatus having a moving body position detecting device for detecting a position of a moving body with respect to a fixed body, wherein the position detecting device is fixed to the moving body and has a set of an S pole and an N pole. And the S pole and the N pole of the magnet fixed to the fixed body and moving together with the moving body when the moving body moves in a first direction or a second direction opposite to the first direction. An electronic apparatus having a position detecting device for a moving object, comprising: one Hall element for detecting the magnetism of the S pole and the N pole when the set passes. 8. The S pole and the N pole are arranged along the moving direction of the moving body, and the pair of the S pole and the N pole is the same as the pair of the adjacent S pole and the N pole. An electronic apparatus comprising the moving object position detecting device according to claim 7 arranged at a pitch. 9. The electronic apparatus according to claim 7, wherein the width W1 of the south pole and the pitch W are W1 = 1/8 W to 1/3 W. 10. The electronic apparatus according to claim 7, wherein a notch portion larger than the size of the Hall element is formed in the pair of the S pole and the N pole. 11. The notch has a square shape, a curved shape,
An electronic apparatus comprising the mobile object position detection device according to claim 7, wherein the electronic device has a triangular shape. 12. The output waveform of the Hall element has a saw-tooth shape, and by comparing the time of the rising part and the time of the falling part of the output waveform, the moving direction of the moving body is in the first direction. The electronic apparatus according to claim 7, further comprising a processing unit configured to determine whether the moving object is in the second direction and to obtain a moving speed of the moving object. 13. A position detecting device for a moving body for detecting a position of the moving body with respect to a fixed body, wherein: a magnet fixed to the fixed body and having a set of an S pole and an N pole; When the moving body moves in the first direction or the second direction opposite to the first direction, the S
A position detecting device for a moving body, comprising: a Hall element for detecting magnetic poles and N poles. 14. The S pole and the N pole are arranged along the moving direction of the moving body, and the pair of the S pole and the N pole is the same as the pair of the adjacent S pole and the N pole. 14. The position detecting device for a moving body according to claim 13, which is arranged at a pitch.