JP3354009B2 - Electrostatic stepping motor and magnetic storage device using the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrostatic stepping motor, and more particularly to an electrostatic stepping motor for rotating a magnetic storage medium in a stepwise manner in a micro magnetic storage device utilizing micromechanics technology.

[0002]

2. Description of the Related Art Japanese Patent Application Laid-Open No. 6-84269 discloses a magnetic storage device which has been filed by the present applicant.

As shown in FIG. 17, a magnetic storage device assembly 10 has an appearance similar to that of a general package LSI, and is mounted on a printed board by soldering leads 11.

The magnetic storage device assembly 10 includes a housing 1.
2 has a configuration in which a magnetic storage device 13 and an IC chip 14 are incorporated.

As shown in FIG. 18, the magnetic storage device 13 includes a magnetic disk 15, an electrostatic stepping motor 16 for rotating the magnetic disk 15 in a stepwise manner, and an arm 17.
A magnetic head 18 used for recording and an MR (magnetoresistive) element 19 used for reproduction on the tip side of the arm 17;
This is a configuration including piezo elements 20 _-1 and 20 _-2 for making the arm 17 vibrate in a simple manner.

Recording (reproduction) of information on the magnetic disk 15 is performed as follows.
The magnetic disk 15 is rotated stepwise by an electrostatic stepping motor 16 as shown by an arrow S, and the magnetic disk 1
This is performed by causing the piezo elements 20 _-1 and 20 _-2 to single-oscillate the arm 17 as indicated by arrows X ₁ and X ₂ when the stop 5 is stopped.

As a result, information is transferred by the magnetic head 18 to the tracks 21 extending in the radial direction of the magnetic disk 15.
Will be recorded. The information recorded on the track 21 is reproduced by the MR element 19.

The conventional electrostatic stepping motor 16 comprises a stator 30 and a rotor 31, as shown in FIG.

The rotor 31 is integral with the magnetic disk 15 and has on its lower surface a plurality of dielectric teeth 32 _-1 .
It has a dielectric tooth pattern 33 of 32 _-6 .

The stator 30 has an equiangular pitch p on the lower surface.₁
Electrodes 34 arranged by_-1~ 34 _-6Electrode pattern
And has a shaft 35.

The electrodes _34-1 and _34-4 are connected to the first electrode pair 3
_6-1 is formed.

[0012] electrodes 34 _-2 and 34 _-5 and is the second electrode pair 3
Form _6-2 .

The electrodes 34 _-3 and 34 _{-6 form a} third electrode pair 3
Form _6-3 .

The driving circuit 37 includes driving voltages # 1, # 2, #
3 is output. The drive voltages # 1, # 2, and # 3 have three phases.

The driving voltage # 1 is supplied to the first terminal _38-1 through the terminal _38-1 .
Is applied to the electrode pair 36 _-1, the driving voltage # 2, the terminal 38
Through _-2 it is applied to the second electrode pair 36 _-2, the drive voltage #
3 is applied to the third electrode pair 36 _-3 through terminal 38 _-3.

Accordingly, as described in detail below, an electrostatic repulsion force and an electrostatic attraction force in a rotating direction are generated between each electrode pair 38 _{-1 to} 38 _-3 and the dielectric tooth pattern 33. Acting, the rotor 31 rotates one step at a time.

FIGS. 20A to 20F show the operation when the rotor 31 rotates one step.

FIG. 20 schematically shows a part of the electrostatic stepping motor 16 in a developed state.

FIGS. 20A to 20F show A to A in FIG.
The state in the section indicated by F is shown, and (A) to (F) representing the division diagram in FIG. 20 correspond to A to F representing the section in FIG.

FIG. 20A, the operation in the section A The dielectric teeth 32 _-1 , 32 _-2 , 32 _-3 , and 32 _-4 are respectively connected to the electrodes 3.
4 _-1 , 34 _-2 , 34 _-3 , 34 _-4 .

The electrodes 34 _-1 and 34 _-4 are positively charged and the electrodes 34 _-2 are negatively charged by the driving voltages # 1, # 2 and # 3.

Thus, the dielectric teeth 32 _-1 , 32 _-2 , 3
Dielectric polarization occurs on the 2 _-4.

Operation in section B of FIG. 20B, the charging of the electrodes 34 _-1 , 34 _-2 , 34 _-4 is reversed, and
_-1 and 34 _-4 are negatively charged, and the electrode 34 _-2 is positively charged.

Thus, the dielectric teeth 32_-1And electrode 34_-1
Between the dielectric teeth 32_-2And electrode 34 _-2Between the dielectric teeth
32_-FourAnd electrode 34_-FourBetween the electrostatic repulsion force F₁Occurs
Then, the rotor 31 floats with respect to the stator 30.

FIG. 20 (C), the working electrode 34 _-2 interval C is positively charged, electrode 34 _-3 is negatively charged.

The electrodes 34 _-1 and 34 _-4 are no longer charged.

As a result, the dielectric teeth 32 _-2 and the electrodes 34 _-2
Between the electrostatic repulsion force F ₁ is generated. Further, between the dielectric teeth 32 _-1 and the electrode 34 _-2 electrode 3 dielectric teeth 32 _-1
4 electrostatic attractive force F ₂ is generated to suck the _-2. Between the dielectric teeth 32 _-2 and the electrode 34 _-3, the electrostatic attractive force F ₂ for sucking the dielectric teeth 32 _-2 to electrode 34 _-3 occurs.

Operation in Section D of FIG. 20 (D) The rotor 30 is rotated in the S direction by being given a thrust by the electrostatic attraction force F ₂ while being kept in a floating state by the electrostatic repulsion force F ₁ . I do.

FIG. 20 (E), operation dielectric teeth 32 _-1 of period E is adsorbed on the electrode 34 _-2 dielectric teeth 32
_-2 are attracted to the electrode 34 _-3.

As a result, the rotor 30 rotates by an angle corresponding to the pitch p ₁ in FIG. 19 and then temporarily stops.

FIG. 20 (F), Operation in Section F The electrodes 34 _-1 , 34 _-2 , 34 _-4 are negatively charged, and the electrodes 34 _-3
Are positively charged.

As a result, the dielectric polarization states of the dielectric teeth 32 _-1 and 32 _-2 are inverted. Also, the dielectric teeth 32 _-3 , 32
_-6 causes dielectric polarization.

The above operation is repeatedly performed, and the rotor 3
1, while rotating by the angle p ₁ in one step, is rotated.

[0034]

In the above-mentioned electrostatic stepping motor 16, the angle between adjacent positions where the rotor 31 temporarily stops is determined by the angle pitch p in FIG.
_The angle is equal to ₁ .

On the other hand, there is a limit in reducing the electrode pitch p ₁ .

For this reason, it is difficult to reduce the angle between adjacent stop positions of the rotor 31.

Also, it was difficult to increase the recording density in the magnetic storage device 13 due to this.

Accordingly, an object of the present invention is to provide an electrostatic stepping motor that solves the above-mentioned problems and a magnetic storage device using the same.

[0039]

According to the first aspect of the present invention, there is provided
Husband of the fan-shaped area of N (an integer of 2 or more) that has been improved and divided
In each case, an electrode pattern section in which a plurality of electrodes are arranged at a pitch p
And the electrode pattern portion of each region has p / N
Has an electrode pattern that is configured to be shifted by
And a stator rotatably provided with respect to the stator.
And a plurality of radially arranged
Having a dielectric tooth pattern comprising a plurality of dielectric teeth
Selected from among the plurality of electrode pattern portions.
The driving voltage is applied to the one electrode pattern portion thus formed.

According to the second aspect of the present invention, in the radial direction and the circumferential direction,
Divided N (integer of 2 or more) concentric and fan-shaped
An electrode pattern in which a plurality of electrodes are arranged at a pitch p in each of the regions
Electrode portion, and the electrode pattern portion of each region
Electrode patterns that are arranged so as to be shifted by p / N
A stator having a dielectric tooth pattern formed of a plurality of dielectric teeth radially arranged facing the electrode pattern, the stator being provided rotatably with respect to the stator, The driving voltage is applied to a selected one of the plurality of electrode pattern portions.

According to a third aspect of the present invention, there is provided the first or second aspect.
In an electrostatic stepping motor, the electrode pattern
Of the N areas of the stator, the area near the center of the stator
The electrode pattern part of the area is a long electrode in the radial direction.
On the electrode pattern in the area near the outer periphery of the stator.
Has an electrode with a short length in the radial direction .

According to a fourth aspect of the present invention, there is provided the first or second aspect of the present invention .
In an electrostatic stepping motor, the electrode pattern
Of the N areas of the stator, the area near the center of the stator
The electrode pattern in the region has electrodes with a long circumferential length.
The electrode pattern in the region near the outer periphery of the stator
Characterized by having an electrode with a short length in the direction
3. The electrostatic stepping motor according to claim 1, wherein

According to a fifth aspect of the present invention, the radially divided N
(An integer of 2 or more) concentric regions,
The electrode has an electrode pattern portion arranged at a pitch p, and
The electrode pattern part of the area is arranged by shifting each electrode by p / N.
And an N region of the stator.
Of the electrode pattern part near the center of the stator
Has an electrode with a long radial length, outside the stator
The length in the radial direction is
Stations with electrode patterns that are arranged with short electrodes
Motor and the stator are provided rotatably with respect to the stator.
Multiple radially arranged dielectrics facing the electrode pattern
Rotor with a dielectric tooth pattern consisting of body teeth
Selected from among the plurality of electrode pattern portions.
One of the electrode pattern portion, in which the driving voltage has a configuration that will be applied.

The invention according to claim 6 is characterized in that the radially divided N
(An integer of 2 or more) concentric regions,
The electrode has an electrode pattern portion arranged at a pitch p, and
The electrode pattern part of the area is arranged by shifting each electrode by p / N.
And an N region of the stator.
Of the electrode pattern part near the center of the stator
Has an electrode whose length in the circumferential direction is long, and
The electrode pattern in the closer area has an electrode with a short circumferential length.
Stator having electrode pattern arranged in poles
And rotatably provided with respect to the stator.
Made of multiple dielectrics radially opposite the pole pattern
Rotor with a dielectric tooth pattern consisting of
Selected one of the plurality of electrode pattern portions.
The electrode pattern portion is obtained by a configuration in which the driving voltage is Ru is applied.

According to a seventh aspect of the present invention, there is provided a disk-shaped magnetic storage medium, a head in contact with the magnetic storage medium, and a reciprocating movement of the head in a radial direction of the magnetic storage medium. Head reciprocating means for forming tracks extending substantially in the radial direction on the magnetic storage medium in a state in which the magnetic storage medium is located, and the individual tracks formed extending in the radial direction are arranged side by side in the circumferential direction of the magnetic storage medium. so formed, thereby stepwise rotating the magnetic storage medium, it is obtained by more become configured as an electrostatic stepper motor of any one of claims 1乃 optimum 6.

[0046]

According to the first aspect, the region is divided in the circumferential direction,
A configuration in which the stator electrode is composed of a plurality of electrode pattern portions;
And a configuration in which electrodes each electrode pattern portion is disposed shifted by p / N serves to narrow the spacing between adjacent positions rotor is temporarily stopped.

According to the second aspect , the region is formed radially and circumferentially.
The configuration divided in the direction increases the number of divided areas.
Acts as follows.

According to claims 3 and 4, the center of the stator is
On the near side, adjust the radial length or circumferential length of the electrode.
Longer, and on the side closer to the outer circumference of the stator, the radial
Configurations with reduced length or circumferential length always have the same level.
Even if a driving voltage of
The generated torque acts so as to be uniform, and each electrode pattern
The drive voltage level applied to the
Acts so as not to need to change .

According to the fifth and sixth aspects, the area is defined in the circumferential direction.
And divide the stator electrode from multiple electrode patterns.
And each electrode pattern portion is not formed by p / N electrodes.
The configuration placed next to where the rotor temporarily stops
It acts to narrow the gap between the fitting positions. Claim 5
However, on the side closer to the center of the stator, the radial
Increase the length and set the radius of the electrode
Configurations with a shorter length in the direction always have the same level of drive power.
Even when pressure is applied, the
It acts so that the torque is uniform, and marks each electrode pattern.
Changing the level of applied driving voltage for each electrode pattern
Acts to make it unnecessary. Claim 6
On the side closer to the center of the data, increase the circumferential length of the electrode,
On the side closer to the outer circumference of the stator, shorten the circumferential length of the electrode.
Configuration, even if the same level of drive voltage is always applied,
The torque generated by each electrode pattern is uniform
And the drive voltage applied to each electrode pattern
No need to change the level for each electrode pattern
Acting on.

[0050] In claim 7, configuration in which an electrostatic stepper motor of any one of claims 1乃 Itaru 6 acts to finely stop position of the magnetic storage medium, the conventional recording density In order to increase the pressure, the means for step-displacing the head reciprocating means itself is not required.

[0051]

【Example】

1 to 3 show an electrostatic stepping motor 50 according to a first embodiment of the present invention.

As shown in FIG. 1 and FIG.
Are a plate-shaped stator 51 and a disk-shaped rotor 53 supported on a shaft 52 and rotatably provided on the stator 51.
And a drive control unit 54.

As shown in FIG. 1, the rotor 53 has a dielectric tooth pattern 55 on the lower surface.

The dielectric tooth pattern 55 will be described later for convenience of explanation.

As shown in FIG. 1 and FIG.
Are a main body 60 and an electrode pattern 61 on the upper surface.
And

The electrode pattern 61 includes three electrode pattern portions 62, 63, and 64.

1 and 2, the upper surface of the stator body 60 is divided into three regions in the radial direction, that is, an annular region 65 on the outer peripheral side and an annular region 65 on the center side. It has a circular region 66 and an annular region 67 intermediate between the regions 65 and 66.

The areas 65, 67, 66 are concentric.

The electrode pattern section 62 is provided in the area 65.

The electrode pattern portion 62 has an equiangular pitch p.₁
A plurality of electrodes 68_-1~ 68 _-6Consisting of

[0061] and the electrode 68 _-1 and 68 _-4, a first electrode pair 69 _-1.

[0062] and the electrode 68 _-2 and 68 _-5, to form a second electrode pair 60 _2.

[0063] electrodes 68 _-3 and the 68 _-6, a third electrode pairs 6
_9-3 is formed.

The electrode pattern section 63 is provided in the area 67.

The electrode pattern section 63 includes a plurality of electrodes 70 _-1.
~ _70-6 .

The electrodes 70 _-1 to 70 _-6 have an angle pitch p ₁ equal to the above-mentioned angle pitch p ₁ , and
Against _-1 to 68 _-6, clockwise, it is provided in an arrangement shifted by p _1/3. Here, the numerical value “3” is in the above area 6
It is a numerical value equal to the number of 5, 66, 67.

The electrodes 70 _-1 and 70 _-4 are connected to the first electrode pair 7.
To form _1-1 .

[0068] and the electrode 70 _-2 and 70 _-5, to form a second electrode pair 71 _2.

[0069] electrodes 70 _-3 and 70 _-6, a third pair of electrodes 71 _-3.

In the region 66, an electrode pattern portion 64 is provided.

The electrode pattern section 64 includes a plurality of electrodes _72-1.
Consisting of 72 _-6.

The electrodes 72 _{-1 to} 72 _-6 have an angle pitch p ₁ equal to the above-mentioned angle pitch p ₁ , and
_-1 to 70 _-6 are provided in the clockwise direction with an offset of p / 3. Here, the numerical value “3” is in the above area 6
It is a numerical value equal to the number of 5, 66, 67.

[0073] and the electrode 72 _-1 and 70 _-4, a first electrode pair 73 _-3.

[0074] and the electrode 72 _-2 and 70 _-5, to form a second electrode pair 73 _2.

[0075] electrodes 72 _-3 and 70 _-6, a third pair of electrodes 73 _-3.

That is, the electrodes 70 _-1 to 70 _-6 and 72 _{-1 to} 72
_-6 are arranged at equal angular intervals between the adjacent electrodes 68 _-1 to 68 _-6 .

In FIG. 1, each of the electrodes 68 _{-1 to} 68 _-6 , 70 _-1 to
Terminals 80 to 9 drawn out from 70 _-6 , 72 _{-1 to} 72 _-6
7 are connected to the terminals 80 to 97 arranged vertically.

Therefore, the electrodes constituting each electrode pair are electrically connected. In practice, the electrodes that make up each electrode pair have a comb-like pattern.

The terminals 100 _{-1 to} 100-1 are connected to each electrode pair.
_-3 is provided.

That is, the first, second, and second electrode patterns 62
Third electrode pattern pair 69_-1, 69 _-2, 69_-3From husband
Terminal 100_-1, 100_-2, 100_-3Is pulled out
I have.

From the first, second, and third electrode pairs 70 _-1 , 70 _-2 , and 70 _-3 of the electrode pattern portion 63, the terminals 101 are respectively provided.
_-1 , 101 _-2 and 101 _-3 are drawn.

From the first, second, and third electrode pairs 73 _-1 , 73 _-2 , and 73 _-3 of the electrode pattern portion 64, the terminals 102 are respectively provided.
_-1 , 102 _-2 , 102 _-3 are extracted.

The dielectric tooth pattern 54 of the rotor 53
Has _six teeth 110 _{-1 to} 110 _-6 . Here, the numerical value “6” is used for each of the electrode pattern portions 62, 63, 64.
The number is the same as the number of electrodes.

Further, the teeth 110 _{-1 to} 110 _-6 are arranged radially, and the angular pitch p ₁ is the angular pitch p of the electrode.
Equal to ₁ .

In FIG. 1, the drive control unit 54 includes a drive circuit 37
, A switch circuit 120, and a control circuit 121.

The drive circuit 37 includes three-phase drive voltages # 1 and #
2 and # 3 are output.

The switch circuit 120 is provided on the output side of the drive circuit 35, and is controlled by the control
00 _{-1 to} 100 _-3 , 101 _{-1 to} 101 _-3 and 102 _-1
It is connected by switching to and -102 _-3.

Next, the operation of the electrostatic stepping motor 50 having the above configuration will be described.

The switch circuit 120 is connected to the terminal group 100 _-1
100 if the system is connected to the _-3 driving voltage # 1 via a terminal 100 _-1, are applied to the electrode pairs 69 _-1 of the electrode pattern 62.

The driving voltage # 2 is supplied via the terminal _100-2 .
The voltage is applied to the electrode pair 69 _-2 of the electrode pattern portion 62.

The driving voltage # 3 is applied via the terminal _100-3 .
It is applied to the electrode pairs 69 _-3 of the electrode pattern 62.

Thus, an electrostatic repulsion force and an electrostatic attraction force are applied between the electrodes 68 _{-1 to} 68 _-6 and the dielectric teeth 110 _{-1 to} 110 _-6 , as shown in FIG.

Thus, the rotor 53 is moved to the specific point 12
2 are the positions 130, 131, 132, 1 in FIG.
Temporarily while stopped at 33, by an angle p ₁ rotates, the stepping operation.

The switch circuit 120 is connected to the terminal group 101 _-1
To 101 when being switched connected to _-3 driving voltage # 1 via a terminal 101 _-1, it is applied to the electrode pairs 71 _-1 of the electrode pattern 63.

The driving voltage # 2 is supplied via the terminal _101-2 .
The voltage is applied to the electrode pair 71 _-2 of the electrode pattern portion 63.

The driving voltage # 3 is applied via the terminal _101-3 .
It is applied to the electrode pairs 71 _-3 electrode pattern 63.

Thus, between the electrodes 70 _-1 to 70 _-6 and the dielectric teeth 110 _{-1 to} 110 _-6 , an electrostatic repulsion force and an electrostatic attraction force act as shown in FIG.

Thus, the rotor 53 moves the specific point 122 to the position 140, 141, 14 in FIG.
Temporarily while it stopped at 2,143, by the angle p ₁ rotates, the stepping operation.

Positions 140 to 143 correspond to position 1 described above, respectively.
The angle is shifted by p / 3 from 30 to 133.

The switch circuit 120 is connected to the terminal group 102 _-1
To 102 when being switched connected to _-3 driving voltage # 1 via a terminal 102 _-1, it is applied to the electrode pairs 73 _-1 of the electrode pattern 64.

[0102] The driving voltage # 2, through the terminal 102 _-2
It is applied to the electrode pairs 73 _-2 electrode pattern part 64.

The driving voltage # 3 is applied via the terminal _102-3 .
It is applied to the electrode pairs 73 _-3 electrode pattern part 64.

As a result, an electrostatic repulsion force and an electrostatic attraction force are applied between the electrodes 72 _{-1 to} 72 _-6 and the dielectric teeth 110 _{-1 to} 110 _-6 as shown in FIG.

As a result, the rotor 53 moves the specific point 122 to the position 150, 151, 15 in FIG.
Temporarily while it stopped at 2,153, by the angle p ₁ rotates, the stepping operation.

The positions 150 to 153 correspond to the positions 1
Against 40-143, it is offset angle p _1/3.

[0106] As seen from the above, according to the electrostatic stepper motor 50 of the present embodiment, by switching the switch circuit 120 as appropriate, the position of the rotor 53 is temporarily stopped, in fineness of p _1/3 That is, 1 /
Determined by the fineness of 3.

[Second Embodiment] FIG. 5 shows an electrostatic stepping motor 160 according to a second embodiment of the present invention.

The motor 160 has a configuration in which a region on the stator is divided in the circumferential direction.

For convenience of illustration, the region is divided into two in the circumferential direction, and the electrode pattern portion is constituted by two electrodes.

The motor 160 has a rotor 161, a stator 162, and a drive control unit 54.

The rotor 161 has a dielectric tooth pattern 163 on the lower surface.

The stator 162 has an electrode pattern 164 on the upper surface.

The upper surface of the stator body 165 is
The fan-shaped regions 166 and 167 are divided into two.

In the region 166, the electrode pattern portion 170 is provided.
Are provided in the region 167 where the electrode pattern portion 171 is provided.
Is provided.

The electrode pattern section 170 includes a plurality of electrodes 17.
2 _-1 and 172 _-2 .

The electrode pattern portion 171 has a plurality of electrodes 17.
3 _-1 and 173 _-2 .

The angular pitch of the electrodes 172 _-1 and 172 _-2 is equal to the angular pitch of the electrodes 173 _-1 and 173 _-2 , that is, p ₂ .

The electrode pattern portion 171 is located at a position 174 where the electrode pattern portion 170 is to be located, assuming that the electrode pattern portion 170 is continuously present in the circumferential direction.
Respect are positioned shifted by p _2/2. here,
The numerical value “2” is a value equal to the number of divided areas.

That is, the electrodes 173 _-1 and 173 _-2 are connected to the electrode 1
Assuming that 72 _-1 and 172 _-2 are further extended in the clockwise direction, p ₂ /
They are offset by two.

Regarding the electrode pattern section 170, the electrode 1
72 _-1 and 172 _{-1 form a} first electrode pair 175 _-1 ;
The electrodes 172 _-2 and 172 _-2 form a second electrode pair 175 _-2 .

For the electrode pattern portion 171, the electrode 1
73 _-1 and 173 _{-1 form a} first electrode pair 176 _-1 ;
The electrodes 173 _-2 and 173 _-2 form a second electrode pair 176 _-2 .

[0122] The dielectric tooth pattern 163 includes a plurality of dielectric teeth 177 _-1 to 177 _-8 arranged above the angular pitch p ₂ equal angular pitch p _2.

The above-described electrostatic stepping motor 160
Are driven by the drive control unit 54 in the same manner as described above.

[0124] When the drive voltage is applied to the electrode pattern portion 170 electrode 172 _-1, 172 _-2 and the dielectric teeth 177 _-1 to 177 _-8
And an electrostatic repulsion force and an electrostatic suction force act between them.

As a result, the rotor 161 moves to the specific point 1
22 are positions 180, 181, 182 and 182 in FIG.
Temporarily while it stopped at 183, rotates by the angle p _2,
Perform stepping operation.

When the switch circuit 120 in FIG. 1 is switched to apply a drive voltage to the electrode pattern portion 171, the electrodes 173 _-1 and 173 _-2 and the dielectric teeth 177 _{-1 to} 177 _-8
And an electrostatic repulsion force and an electrostatic suction force act between them.

As a result, the rotor 161 moves the specific point 122 to the position 190, 191, 1 in FIG.
Temporarily while it stopped at 92,193, each angle p ₂ rotates, the stepping operation.

Here, the positions 190, 191 and 192 are
Against each said position 180, 181, 182, are offset angle p _2/2.

As can be seen from the above description, according to the electrostatic stepping motor 160 of the present embodiment, by appropriately switching the switch circuit 120 in FIG.
There position to temporarily stop, in fineness of p _2/2, i.e., determined by the fineness of the conventional 1/2.

[Third Embodiment] FIG. 7 shows an electrostatic stepping motor 200 according to a third embodiment of the present invention.

The area on the upper surface of the stator 201 is divided in both the radial direction and the circumferential direction.

The number of divisions in the radial direction is two, and the number of divisions in the circumferential direction is two.

Therefore, the upper surface of the stator 201 is 2 × 2.
Divided into four regions 202 _-1~ 202_-FourHave
You.

[0134] Each area 202 _-1 to 202 _-4, has a fan shape.

[0135] region 202 _-1, and 202 _-3, region 20
_2-2, the 202 _-4, and forms a concentric.

The stator 201 has the electrode pattern 2
03.

The electrode pattern 203 is_-1Inside
Electrode pattern section 204_-1And the area 202_-2Electrode pattern inside
Area 204_-2And the area 202_-3Electrode pattern 2 inside
04 _-FourAnd the area 202_-FourElectrode pattern part 204 inside_-FourWhen
Consisting of

Each of the electrode pattern portions 204 _{-1 to} 204 _-4
A plurality of electrodes 205 are configured to arranged at a pitch p _3.

[0139] electrode pattern part 204 _-1 and 204 _-2,
p _2/2 is shifted. Here, the numerical value "2" is a number equal to the number of radially divided areas.

[0140] electrode pattern part 204 _-3, to the electrode pattern part 204 _-1, and p _3/4 shift. Similarly, the electrode pattern 204 _-4, the electrode pattern portion 204 _-2, and p _3/4 shift.

The dielectric tooth pattern 210 of the rotor has a configuration in which a plurality of dielectric teeth 211 (only three are shown for convenience of illustration) are arranged at an angular pitch p ₃ .

[0142] Electrostatic stepper motor 200, the electrode pattern 204 _-1 20 a drive voltage from the drive control unit 54
_4-4 is selectively applied, and a stepping operation is performed by an electrostatic repulsion force and an electrostatic attraction force.

[0143] rotor when the driving voltage is applied to the electrode pattern part 204 _-1, a particular point, as shown in FIG. 8 (A), temporarily stops at the position 220,221,222,223 while, rotated by an angle p _3.

[0144] rotor when the driving voltage is applied to the electrode pattern portion 204 _-2, the specific points, as shown in FIG. 8 (B), temporarily in position 230,231,232,233 while stopped, rotated by an angle p _3.

[0145] When the drive voltage is applied to the electrode pattern part 204 _-3 rotor, the specific points, as shown in FIG. 8 (C), temporarily in position 240,241,242,243 while stopped, rotated by an angle p _3.

[0146] When the drive voltage is applied to the electrode pattern part 204 _-4 rotor, the specific points, as shown in FIG. 8 (D), temporarily in position 250,251,252,253 while stopped, rotated by an angle p _3.

Here, positions 240 to 243 correspond to position 22
Respect 0-223, it is offset angle p _3/4.

Similarly, positions 250 to 253 correspond to position 23
It is offset angle p _3/4 with respect to 0-233.

[0149] As seen from the above, according to the electrostatic stepping motor 200 of the present embodiment, by switching the switch circuit 120 in FIG. 1 as appropriate, the position of the rotor is temporarily stopped, the p _3/4 It is determined by the fineness, that is, 1/4 of the conventional fineness.

[Fourth Embodiment] FIG. 9 shows an electrostatic stepping motor 260 according to a fourth embodiment of the present invention.

The present embodiment has properties similar to those of the first embodiment.

In FIG. 9, the same portions as those shown in FIG. 1 are denoted by the same reference numerals, and portions corresponding to the portions shown in FIG. 1 are denoted by the same reference numerals with a suffix a.

The fan-shaped electrode 68a in the region 65a, the region 6
The fan-shaped electrode 70a in 7a and the fan-shaped electrode 72a in the region 66a both have the same opening angle α.

The electrode 68a has a radial length (r ₄ −
r ₃ ).

The electrode 70a has a radial length (r ₃ −
r ₂ ).

The electrode 72a has a radial length (r ₂ −
r ₁ ).

[0157] Here, the radius r ₁ ~r ₄ is determined to be the so as to satisfy the following equation ^{_{r 4 3 -r 3 3 = r}} 3 3 -r 2 3 = r 2 3 -r 1 3.

That is, (r ₄ −r ₃ ) <(r ₃ −r ₂ ) <
(R ₂ −r ₁ ).

Here, since the radii r _{1 to} r ₄ are determined as described above, as will be described later, each electrode 68
a, 70a, the torque T ₁ generated by 72a,
T ₂ and T ₃ become equal.

Generally, the torque T is obtained by the following equation.

[0161]

(Equation 1)

Here, f (r) is the thrust (force F _{2 in} FIG. 20) generated by the unit length of the electrode. Thrust f
(R) is considered to be constant for each of the electrodes 68a, 70a, 72a.

Under the condition that the vertical f (r) is constant,

[0164]

(Equation 2)

Solving the [0165], and _{^{r 4 3 -r 3 3 = r}} 3 3 -r 2 3 = r 2 3 -r 1 3.

Therefore, the above-described electrostatic stepping motor 2
According to 60, by applying the same level of driving voltage to the electrodes 68a, 70a, 72a of any of the regions 65a, 67a, 66a, the rotor 50 is moved to the region 65a.
When driven by the electrode 68a of the
When driven by the electrode 70a, the region 66a
When they are driven by the electrode 72a, they are all rotated with the same torque.

That is, it is not necessary to change the level of the driving voltage to be applied for each region, and the driving control unit 54 has a simple configuration as compared with a configuration in which the level of the driving voltage to be applied is changed for each region.

[Fifth Embodiment] FIG. 10 shows an electrostatic stepping motor 270 according to a fifth embodiment of the present invention.

This embodiment is a modification of the fourth embodiment.

In FIG. 10, the same parts as those shown in FIG. 1 are denoted by the same reference numerals, and the parts corresponding to the parts shown in FIG.
The same reference numerals with the suffix b are used.

The fan-shaped electrode 68b in the area 65 has an opening angle α ₁ and a circumferential length l ₁ .

The fan-shaped electrode 70b in the region 67 has an opening angle α ₂ and a circumferential length l ₂ .

The fan-shaped electrode 72b in the region 66 has an opening angle α ₃ and a circumferential length l ₃ .

Here, the opening angles α ₁ , α ₂ , α ₃ satisfy α ₁ <α ₂ <α ₃ .

The circumferential lengths l ₁ , l ₂ and l ₃ satisfy the relation l ₁ <l ₂ <l ₃ .

Opening angles α ₁ , α ₂ , α ₃ and circumferential length l
The relationship between ₁ , l ₂ and l ₃ is determined so that when the same level of drive voltage is applied to the electrodes 68b, 70b and 72b in the regions 65, 67 and 66, the same torque is applied to the rotor 50. It is.

According to the present embodiment, there is an effect similar to that of the above-described fourth embodiment, that the drive control unit 54 can be simplified.

Although each of the above embodiments has been described with reference to a rotary type electrostatic stepping motor, the present invention is not limited to this, and a linear type electrostatic stepping device in which a moving body moves linearly with respect to a fixed body. It can also be applied to motors.

[Magnetic Storage Device] Next, a magnetic storage device 300 to which the electrostatic stepping motor 50 shown in FIG. 1 is applied will be described.

In FIGS. 11 and 12, reference numeral 311 denotes a silicon or ceramic substrate.

Reference numeral 312 denotes a disk-shaped magnetic disk having a diameter D of, for example, about 10 mm. The center is supported by the shaft 313 and disposed on the substrate 311.

Reference numeral 316 denotes a head support arm, the base side of which is fixed on the substrate 311 by a fixing portion 317.
It extends parallel to the Y-axis 315, and the tip is the X-axis 31
4 above.

At the tip of the arm 316, a recording head 318 used for recording and a magnetoresistive element (hereinafter, referred to as MR element) 319 used for reproduction are provided. The recording head 318 and the MR element 319 constitute a magnetic head.
12 is attached.

The arm 316 has a slit at the center.
And a pair of arms. The head goes to this arm
Piezo element 320 made of ZnO as return movement means_-1, 3
20 _-2Is provided.

As shown in FIG. 12, an electrostatic stepping motor 50 as a magnetic disk rotating means shown in FIG. 1 is provided between the magnetic disk 312 and the substrate 311.

As shown in FIG. 16, this device 300
The LSI chip 23 is placed in a housing 312 made of synthetic resin.
2 to form a magnetic storage device assembly 330.

The LSI chip 32 incorporates a signal processing circuit 333, a piezo element driving circuit 334, a driving circuit 337, a switch circuit 120, and the like, as shown in FIG.

The motor 50 has the following first, second,
A third stepping operation is performed.

First stepping operation: driving voltages # 1 to # 1
Rotor 53 when # 3 is applied to electrode pattern portion 62
Step operation.

Second stepping operation: driving voltages # 1 to # 1
Rotor 53 when # 3 is applied to electrode pattern portion 63
Step operation.

Third Stepping Operation: Drive Voltages # 1 to # 1
Rotor 53 when # 3 is applied to electrode pattern portion 63
Step operation.

On the outer peripheral side of the magnetic disk 312, position information 340 indicating a position where a track is to be formed is recorded in advance.

Further, as shown in FIG.
2, position information Q ₁ and Q ₂ indicating a recording end position are recorded in advance at positions where short tracks are to be formed.

Next, the operation when information is first recorded on the entire magnetic disk 312 will be described. First, the motor 50 performs a first stepping operation.

While the rotor 53 is temporarily stopped,
Piezoelectric elements 320 _-1, 320 _-2 driving signal is applied in phase is the inverse of the alternating voltage, the arm 316 is simple harmonic motion.

As a result, as shown in FIG.
On the magnetic disk 312 which is temporarily stopped, a long track 341 extending in the radial direction is formed, and information is recorded here.

During the first rotation of the rotor 53, the first stepping operation of the motor 50 and the arm 316
Is repeated alternately.

As a result, the magnetic disk 312
As shown in 3 (A), the long track 341 arranged over the entire circumference at an angular pitch p ₃ in the circumferential direction track pattern is formed.

Next, the motor 50 performs the second stepping operation.

While the rotor 53 is temporarily stopped,
The arm 316 makes a simple vibration.

As a result, as shown in FIG.
For near the outer periphery side of the magnetic disc 312, the position of the gap between the long track 341 adjacent the circumferential direction, the degree of long track in which the center side end of the magnetic disk 312 and Q ₁ 342 Is formed, and information is recorded here.

The above operation is performed during the next rotation of the rotor 53.

Next, the motor 50 shifts to the third stepping operation.

The arm 316 vibrates simply while the rotor 53 is temporarily stopped.

As a result, as shown in FIG.
In the portion of the magnetic disk 312 closer to the outer periphery, a short track 3 having a terminating end of Q ₂ is located at a gap between the medium length track 342 and the long track 341.
43 is formed, and information is recorded here.

As described above, a track pattern in which medium-length tracks 342 and short tracks 342 enter at equal pitches between adjacent long tracks 341 in the circumferential direction of the magnetic disk 312 is formed. . Pitch between the tracks is p _1/3.

As a result, when a long track 342 is formed in the magnetic disk 312, a track is also formed in a vacant portion near the outer peripheral side of the magnetic disk 312, so that information can be compared with the conventional case. It is recorded at high density.

Each track 341, 342, 343
Is as shown in FIG.

The position information 34 is provided on the outer peripheral side of the magnetic disk 312.
0, and the other part is the recorded content 343.

Next, the actual operation of the device 300 will be described with reference to FIGS.

In FIG. 15, first, information on the current track is read (step 1).

At this time, there is no change in the drive voltage from the motor drive circuit 37 in FIG. 11 (reference numeral 51 _-1 in FIG. 16B), the motor 50 is stopped, and the magnetic disk 312 is stopped.
Has stopped.

Also, from the piezo drive circuit 334, FIG.
Piezoelectric element drive signal is an alternating voltage represented by the middle code 350 _-1 (A) is output, the piezoelectric element 320 _-1, 320 _-2 is driven arm 316 is a single vibration, MR element 319 of the current track Read the data.

Next, the position information is analyzed (step 2).

Here, the signal processing circuit 333 in FIG.
Analyzes the position information from the read data.

Next, the magnetic disk is rotated by a predetermined angle in accordance with the amount of deviation between the current track and the target track to move the current track (step 3).

The signal processing circuit 333 calculates the shift amount between the current track and the target track, and
Is operated, and a three-phase drive voltage indicated by reference numeral _51-2 in FIG. 7B is output from the circuit 37.

Further, the switch circuit 120 is switched by a signal from the signal processing circuit 333.

As a result, the three-phase driving voltage is applied to the electrodes in a predetermined area of the electrostatic stepping motor 50 via the switch circuit 120.

As a result, the motor 50 (rotor 53)
Perform a stepping operation of a predetermined amount (one step in FIG. 16).

Thereafter, the drive voltage does not change (35).
1 _-3 ), the rotor 53 is stopped at the rotation position at this time.

Thus, the magnetic disk 312 is rotated by a predetermined angle, and the target track reaches the position of the MR element 19.

Next, data is read or written (step 4).

[0224] The drive signal shown in FIG. 16 (A) Medium code 350 _-1 piezo driving circuit 334 is outputted, the magnetic disc 31
With the arm 2 stopped, the arm 316 again makes a single oscillation, and the MR element 319 reads information from the target track, or the recording head 318 writes information on the target track.

Note that the read information is, for example, as shown in FIG.
The data is written into the RAM 337 provided outside the assembly 11 via the medium signal processing circuit 333, and can be accessed from outside.

[0226]

As described in the foregoing, according to the first aspect of the present invention, the rotor is a position to stop temporarily, it is possible to define several times finer than the conventional.

According to the second aspect of the present invention, the first aspect of the present invention is provided.
The position where the rotor stops temporarily is more detailed than
Can be determined.

According to the third and fourth aspects of the present invention, which electrode
A constant level of drive voltage is always applied to the pattern area.
Can be added, simplifying the configuration of the drive control system
And

According to the fifth and sixth aspects of the present invention, the rotor
Temporary stop position is defined several times finer than before
In addition to this, a constant level of drive voltage can always be applied to any of the electrode pattern portions, and the configuration of the drive control system can be simplified.

According to the seventh aspect of the present invention, the recording on the magnetic storage medium can be performed at a high density with a simple configuration in which the head reciprocating means is fixed.

[Brief description of the drawings]

FIG. 1 is a diagram showing an electrostatic stepping motor according to a first embodiment of the present invention.

FIG. 2 is a diagram showing an electrode pattern of a stator in FIG.

FIG. 3 is a sectional view of the electrostatic stepping motor of FIG. 1;

FIG. 4 is a diagram for explaining a stepping operation of a rotor.

FIG. 5 is a diagram illustrating an electrostatic stepping motor according to a second embodiment of the present invention.

FIG. 6 is a diagram for explaining a stepping operation of the rotor.

FIG. 7 is a view showing a stator of an electrostatic stepping motor according to a third embodiment of the present invention.

FIG. 8 is a diagram for explaining a stepping operation of the rotor.

FIG. 9 is a view showing an electrostatic stepping motor according to a fourth embodiment of the present invention.

FIG. 10 is a view showing an electrostatic stepping motor according to a fifth embodiment of the present invention.

FIG. 11 is an enlarged view showing a magnetic storage device according to an embodiment of the present invention, together with a control system.

FIG. 12 is a longitudinal sectional view of the magnetic storage device of FIG. 11;

FIG. 13 is a diagram for explaining formation of a track pattern in FIG. 11;

FIG. 14 is a diagram showing a format of a track.

FIG. 15 is a flowchart of the operation of the apparatus of FIG. 11;

FIG. 16 is a waveform diagram of a signal of each unit in FIG.

FIG. 17 is a perspective view of a magnetic storage device assembly in which the magnetic storage device of the present applicant has been applied.

FIG. 18 is a diagram showing a magnetic storage device filed by the present applicant earlier.

19 is a diagram showing the electrostatic stepping motor in FIG.

20 is a diagram for explaining the operation of the electrostatic stepping motor of FIG.

[Explanation of symbols]

50 Electrostatic stepper motor 51 stator 52 shaft 53 rotor 54 drive control unit 55 dielectric tooth pattern 60 stator body 61 the electrode patterns 62, 63, 64 electrode pattern part 65 the outer peripheral side of the region 66 the center side of the region 67 intermediate areas 68 _{- 1-68 -6} electrodes 69 _-1, 69 _-2, 69 _-3 electrode pairs 70 _-1 to 70 _-6 electrodes 71 _-1, 71 _-2, 71 _-3 electrode pairs 72 _-1 to 72 _-6 electrodes 73 _{- 1} , 73 _-2 , 73 _-3 Electrode pair 80-97 terminal 100 _-1 -100 _-3 terminal 110 _-1 -110 _-6 dielectric tooth 120 switch circuit 121 control circuit 122 specific point on rotor 130-133 140 to 143, 150 to 153 Position where rotor temporarily stops 160 Motor 161 Rotor 162 Stator 163 Dielectric tooth pattern 164 Electrode pattern 165 Stator body 66,167 regions 170 electrode pattern part 171 electrode pattern part 172 _-1, 172 _-2, 173 _-1, 173 _-2 electrode 174 position 175 _-1, 175 _-2, 176 _-1, 176 _-2 electrode pair 177 _-1 177 _-6 dielectric teeth 180～183,190～193 rotor temporarily position 200 electrostatic stepper motor 201 stator 202 to stop _-1 to 202 _-4 regions 203 electrode pattern 204 _-1 to 204 _-4 electrode pattern part 205 electrode 210 dielectric tooth pattern 211 dielectric tooth 220-223, 230-233, 240-243, 2
50-253 rotor temporarily stop positions 260, 270 Electrostatic stepper motor 300 magnetic storage device 311 substrate 312 magnetic disk 313 shaft portion 316 a head supporting arm 317 fixed portion 318 recording head 319 MR elements 320 _-1, 320 _{- 2} Piezo element 330 Magnetic storage device assembly 332 LSI chip 333 Signal processing circuit 334 Piezo element driving circuit 340 Position information 341 Long track 342 Medium length track 343 Short track 344 Recorded content 350 Piezo element driving signal 351 (# 1 , # 2, # 3) drive voltage

Continuation of front page (56) References JP-A-5-122948 (JP, A) JP-A-4-198890 (JP, A) JP-A-3-65082 (JP, A) JP-A-3-65081 (JP) (A) JP-A 1-259769 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H02N 1/00 G11B 19/20 G11B 25/04 101

Claims (7)

(57) [Claims] (1)N divided in the circumferential direction (an integer of 2 or more)
A plurality of electrodes are arranged at a pitch p in each of the fan-shaped regions of
Electrode pattern portion, and the electrode pattern portion of each region
Is a configuration in which the electrodes are arranged shifted by p / N.
A stator having an electrode pattern;  The electrode pad is rotatably provided with respect to the stator.
A plurality of radially arranged dielectric teeth facing the turn
A rotor having a dielectric tooth pattern comprising: a selected one of the plurality of electrode pattern portions;
The drive voltage is applied to the pattern part.
Characteristic electrostatic stepping motor. (2)N (2) divided radially and circumferentially
Each of the concentric and fan-shaped regions of
A plurality of electrodes having electrode pattern portions arranged at a pitch p, and
The electrode pattern part of each area shifts each electrode by p / N
Having an electrode pattern that is configured to be arranged
And  The electrode pad is rotatably provided with respect to the stator.
A plurality of radially arranged dielectric teeth facing the turn
A rotor having a dielectric tooth pattern comprising: a selected one of the plurality of electrode pattern portions;
The drive voltage is applied to the pattern part.
Characteristic electrostatic stepping motor. 3. The method according to claim 1, wherein the electrode pattern is N
Of the area near the center of the stator
The part has an electrode with a long radial length, and the stator
The electrode pattern in the area near the outer periphery of
Characterized by having an electrode with a short length
Item 3. The electrostatic stepping motor according to item 1 or 2 . 4. The method according to claim 1, wherein the electrode pattern is N
Of the area near the center of the stator
The stator portion has an electrode with a long circumferential length, and
The length of the electrode pattern in the area near the outer periphery is short in the circumferential direction
A structure having a plurality of electrodes.
Is an electrostatic stepping motor according to 2. 5. N divided radially (an integer of 2 or more)
In each of the concentric regions , a plurality of electrodes are arranged at a pitch p.
Electrode pattern portion, and the electrode pattern of each region
In which the electrodes are arranged by shifting each electrode by p / N.
And in the N region of the stator,
The electrode pattern in the area near the center of the
Electrode with a long electrode and a region near the outer periphery of the stator
The pattern portion has an electrode with a short radial length.
A stator having an electrode pattern, and an electrode pattern rotatably provided with respect to the stator.
A plurality of radially arranged dielectric teeth facing the turn
One of the plurality of electrode pattern portions , comprising a rotor having a dielectric tooth pattern comprising
An electrostatic stepping motor , wherein a driving voltage is applied to a pattern section . 6. N divided in the radial direction (an integer of 2 or more)
In each of the concentric regions, a plurality of electrodes are arranged at a pitch p.
Electrode pattern portion, and the electrode pattern of each region
In which the electrodes are arranged by shifting each electrode by p / N.
And in the N region of the stator,
The electrode pattern in the area near the center of the
Have long electrodes, and the electrode pads in the area near the outer periphery of the stator
The turn section has an arrangement having electrodes with a short circumferential length.
A stator having an electrode pattern that is rotatable with respect to the stator;
A plurality of radially arranged dielectric teeth facing the turn
One of the plurality of electrode pattern portions , comprising a rotor having a dielectric tooth pattern comprising
An electrostatic stepping motor , wherein a driving voltage is applied to a pattern portion . 7. A disk-shaped magnetic storage medium, a head in contact with the magnetic storage medium, and a magnetic storage in a state where the head is reciprocated in a radial direction of the magnetic storage medium and is substantially stopped. A head reciprocating means for forming tracks extending substantially in the radial direction on the medium; and so that the individual tracks formed extending in the radial direction are formed side by side in the circumferential direction of the magnetic storage medium. , magnetic storage device, characterized in that said magnetic storage medium is stepwise rotated, and more become configured as an electrostatic stepper motor of any one of claims 1乃 optimum <br/> 6.