JPH05224751A - Electrostatic actuator - Google Patents

Electrostatic actuator

Info

Publication number
JPH05224751A
JPH05224751A JP2302592A JP2302592A JPH05224751A JP H05224751 A JPH05224751 A JP H05224751A JP 2302592 A JP2302592 A JP 2302592A JP 2302592 A JP2302592 A JP 2302592A JP H05224751 A JPH05224751 A JP H05224751A
Authority
JP
Japan
Prior art keywords
movable
electrode
voltage
electrostatic actuator
comb
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
JP2302592A
Other languages
Japanese (ja)
Inventor
Wataru Nakagawa
Michihiko Tsuruoka
亘 中川
亨彦 鶴岡
Original Assignee
Fuji Electric Co Ltd
富士電機株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Fuji Electric Co Ltd, 富士電機株式会社 filed Critical Fuji Electric Co Ltd
Priority to JP2302592A priority Critical patent/JPH05224751A/en
Publication of JPH05224751A publication Critical patent/JPH05224751A/en
Granted legal-status Critical Current

Links

Abstract

(57) [Abstract] [Purpose] It is possible to flexibly meet various demands by making it possible to control the amount of displacement with an electrostatic actuator. [Structure] Between the fixed electrodes 11A and 11B and the movable electrode 21, the detection electrode 4 is arranged so as to face the movable electrode 21 of the electrostatic actuator that displaces the movable electrode 21 in the vertical direction in the figure by using electrostatic force. Then, the capacitance is detected by the detector 6 to obtain a signal corresponding to the displacement amount, and the deviation between this and the command value set by the setter 8 is obtained by the comparison calculation circuit 7 to obtain the voltage control unit 9. By controlling the voltage of the fixed electrodes 11A and 11B by obtaining a voltage signal that eliminates the deviation between the two, it is possible to displace or stop at a desired position.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a microminiature electrostatic actuator for displacing an object by utilizing electrostatic force between electrodes, and more particularly to an electrostatic actuator capable of position control.

[0002]

2. Description of the Related Art FIG. 3 shows a conventional example of this type. this is,
The comb-shaped fixed electrode K and the movable electrode M are meshed with each other with an appropriate gap provided, and a voltage is applied to both to displace them in the longitudinal direction of the comb teeth and electrostatically drive in proportion to the number of comb teeth. It is to gain strength. When a voltage is applied as described above, it is displaced in the direction of arrow R1, and when a voltage is applied as described above, it is displaced in the direction of arrow R2. In addition, H shows a support part (fixed part). The electrostatic driving force F acting in this case is ε is the relative permittivity, ε 0 is the vacuum permittivity, d is the gap distance, n is the number of comb teeth, t is the tooth thickness, and V is the applied voltage, It is expressed as F = ε · ε 0 · n · t · V 2 / 2d.

FIG. 4 shows another conventional example. In this method, the fixed electrode K and the movable electrode M are arranged so as to face each other, and a voltage is applied to the fixed electrode K and the movable electrode M to obtain an electrostatic driving force in the direction of reducing the gap as indicated by arrow F. In this case, the electrostatic driving force F is ε as relative permittivity, ε 0 as vacuum permittivity, d as gap distance, and S
Is the facing area and V is the applied voltage, F = ε · ε 0 · S · V 2 / 2d 2 .

However, since the latter one is inversely proportional to the square of the gap distance d, there is a problem that the driving force cannot be obtained if the gap is set large to increase the displacement amount. On the other hand, the former can make the displacement larger than the latter, but there is a limit in the number of comb teeth that can be manufactured, the gap distance, the tooth thickness, etc., and as a result, there is a problem that a large driving force cannot be obtained. .. Therefore, the applicant has proposed the following electrostatic actuator (also referred to as a proposed device).

FIG. 5 is a perspective view showing the proposed device. In the figure, 1 is a fixing member on which the comb-teeth-shaped fixed electrode 11 is formed, and 2 is the first and second movable electrodes 21A and 21B (see FIG. 6) formed via an insulator 21C. The movable members 3A and 3B are guide members. That is, the comb-teeth fixed electrode 1 and the pair of comb-teeth movable electrodes 2 insulated from each other are arranged so as to mesh with each other.
Although a spring is assumed here as the guide member, any member having a function equivalent to this may be used.

FIG. 6 is an explanatory diagram for explaining the principle of the proposed device. This shows a part of the A cross section of FIG. 5, and shows two fixed electrodes 11A and 11B and a pair of movable electrodes 2
1A and 21B are arranged as shown in the figure. For example, by connecting the movable electrode 21A and the fixed electrodes 11A and 11B to the negative electrode of the power source V and connecting the movable electrode 21B to the positive electrode of the power source V, the movable electrode 21A, The electric field strengths acting on 21B are made different from each other to obtain the electrostatic driving force F. The electrostatic driving force F at this time is F = ε · ε 0 · n · L · V 2 / 2d. Here, L represents the length of the comb-teeth electrode. At this time, a force is generated in the movable electrode as long as the movable electrode is in the fixed electrode. Therefore, the displacement amount can be increased by increasing the thickness of the fixed electrode. Further, since the generated force is proportional to the length L of the comb-teeth electrode, the electrostatic driving force F can be made larger than that of the conventional one. Also, FIG.
In the case shown in (1), the force is always actuated at half of the total number of comb teeth when driven, but in this embodiment, the force is always generated at the total number of comb teeth, so that a larger force can be obtained.

Therefore, in the configuration of FIG. 5, the guide member 3B and the fixing member 1 are connected as shown in FIG.
When the voltage V shown by the solid line is applied between A and the fixed member 1, the movable member 2 moves in the direction (upward) shown by the arrow of the solid line according to the above principle. In addition, the guide member 3A and the fixed member 1 are connected as shown in FIG.
When the voltage is applied, the movable member 2 moves in the direction (downward) indicated by the dotted arrow by the same principle. At this time,
Since a voltage is applied to the movable electrodes 21A and 21B via the guide members 3A and 3B, the guide member 3A and the movable electrode 21A and the guide member 3B and the movable electrode 21B are electrically connected to each other.

[0008]

By the way, in such an electrostatic actuator, there is a demand for moving the movable member to a desired position or stopping the movable member. There remains a problem that actuators cannot meet such demands. Therefore, an object of the present invention is to provide an electrostatic actuator capable of controlling the position of a movable member.

[0009]

In order to solve such a problem, according to the present invention, a fixing member having a comb-teeth-shaped fixed electrode and a comb which is insulated from each other by an insulator and meshes with the comb teeth of the fixed electrode. A movable member having tooth-shaped first and second movable electrodes and a guide member for guiding the movable member in only one direction are provided, and one of the movable electrodes and the fixed electrode are provided via the guide member. In an electrostatic actuator that drives the movable member in one direction by applying a voltage between the other movable electrodes, a detection electrode for detecting a change in capacitance is arranged near the movable member. The displacement of the movable member is detected from the change in the electrostatic capacity, and the position of the movable member can be controlled based on the deviation signal as a result of comparing this signal with a reference signal.

[0010]

In the proposed device, a detection electrode for detecting a change in electrostatic capacitance is arranged near the movable member, the displacement of the movable member is detected from the change in the electrostatic capacitance, and this signal is used as a reference signal. It is possible to control the position of the movable member based on the deviation signal as a result of comparison with the above, and to meet various requirements.

[0011]

1 is a perspective view showing an embodiment of the present invention, FIG.
FIG. 3 is a block diagram showing an electrical configuration of FIG. 1. As is clear from FIG. 1, this embodiment is characterized in that the detection electrode 4 having an insulator 5 partially formed is provided in the configuration. As shown in the drawing, the detection electrode 4 has a central portion which is further raised, and this portion is inserted into a window formed in the fixed member 1 so as to face the movable electrode 21 of the movable member 2. An insulator 5 is provided on the lower portion of the detection electrode 4 to insulate the fixing member 1. The configuration and operation of the electrostatic actuator are the same as those described with reference to FIG. 5, and therefore the description thereof will be omitted. Below, how to perform the position control will be described with reference to FIG.

Since the detection electrode 4 is arranged so as to face the movable electrode 21 as shown in FIG. 1, when the movable electrode 21 is displaced, the distance from the detection electrode 4 changes, which appears as a change in capacitance. Therefore, if the capacitance detector 6 is provided and the capacitance is detected, the amount of displacement of the movable electrode 21 from the reference position can be known conversely. Therefore, in order to perform control for displacing or stopping the movable electrode 21 to a desired position, a signal corresponding to the amount of displacement from the reference position is given to the setter 8 as a command value, and this and the capacitance detector 6 The deviation from the output of is calculated by the comparison calculation circuit 7, the voltage control unit 9 performs a control calculation to make this deviation zero, and the voltage applied to the fixed electrodes 11A and 11B is controlled based on the result. The movable electrode 21 can be displaced or stopped at a desired position. That is, it can be said that the voltage control unit 9 plays a role as a regulator capable of performing control calculation. As described above, by adding the position control function to the electrostatic actuator, it becomes possible to provide an electrostatic actuator that can meet various requirements.

[0013]

According to the present invention, since the position control function is added to the electrostatic actuator, it is possible to flexibly meet various demands.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of the present invention.

FIG. 2 is a block diagram showing an electrical configuration of FIG.

FIG. 3 is a schematic diagram showing a conventional example.

FIG. 4 is a schematic diagram showing another conventional example.

FIG. 5 is a perspective view showing a proposed device.

FIG. 6 is an explanatory diagram for explaining the principle of FIG. 5;

[Explanation of symbols]

1 ... Fixed member, 2 ... Movable member, 3A, 3B ... Guide member,
4 ... Detection electrode, 5, 21C ... Insulator, 6 ... Capacitance detector, 7 ... Comparison arithmetic circuit, 8 ... Setting device, 9 ... Voltage control unit,
11, 11A, 11B ... Fixed electrodes, 21, 21A, 21
B ... Movable electrode.

Claims (1)

[Claims]
1. A fixed member having a comb-teeth-shaped fixed electrode, and a movable member having comb-teeth-shaped first and second movable electrodes which are insulated from each other by an insulator and mesh with the comb-teeth of the fixed electrode. A guide member for guiding the movable member in only one direction,
An electrostatic actuator that drives the movable member in one direction by applying a voltage between one of the movable electrodes and a fixed electrode and the remaining movable electrode via the guide member, wherein the movable member A detection electrode for detecting a change in capacitance is placed near the sensor to detect the displacement of the movable member from this change in capacitance, and this signal is compared with a reference signal to move based on the deviation signal. An electrostatic actuator characterized in that the position of a member can be controlled.
JP2302592A 1992-02-10 1992-02-10 Electrostatic actuator Granted JPH05224751A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2302592A JPH05224751A (en) 1992-02-10 1992-02-10 Electrostatic actuator

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP2302592A JPH05224751A (en) 1992-02-10 1992-02-10 Electrostatic actuator

Publications (1)

Publication Number Publication Date
JPH05224751A true JPH05224751A (en) 1993-09-03

Family

ID=12098944

Family Applications (1)

Application Number Title Priority Date Filing Date
JP2302592A Granted JPH05224751A (en) 1992-02-10 1992-02-10 Electrostatic actuator

Country Status (1)

Country Link
JP (1) JPH05224751A (en)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2006224224A (en) * 2005-02-16 2006-08-31 Fujitsu Ltd Micro-oscillating element and its manufacturing method
US7197815B2 (en) 1999-09-03 2007-04-03 Canon Kabushiki Kaisha Method of manufacturing the electromagnetic actuator
JP2007093816A (en) * 2005-09-27 2007-04-12 Matsushita Electric Works Ltd Method of manufacturing vertical comb actuator
US7263039B2 (en) 2002-08-13 2007-08-28 Lg Electronics Inc. Micro-actuator, manufacturing method thereof, optical pickup head of optical recording/reproducing apparatus with micro-actuator and manufacturing method thereof
US8154784B2 (en) 2007-09-12 2012-04-10 Ricoh Company, Ltd. Optical scanning device and image forming apparatus

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7197815B2 (en) 1999-09-03 2007-04-03 Canon Kabushiki Kaisha Method of manufacturing the electromagnetic actuator
US7263039B2 (en) 2002-08-13 2007-08-28 Lg Electronics Inc. Micro-actuator, manufacturing method thereof, optical pickup head of optical recording/reproducing apparatus with micro-actuator and manufacturing method thereof
JP2006224224A (en) * 2005-02-16 2006-08-31 Fujitsu Ltd Micro-oscillating element and its manufacturing method
US8142670B2 (en) 2005-02-16 2012-03-27 Fujitsu Limited Micro-oscillating element and method of making the same
JP2007093816A (en) * 2005-09-27 2007-04-12 Matsushita Electric Works Ltd Method of manufacturing vertical comb actuator
JP4534931B2 (en) * 2005-09-27 2010-09-01 パナソニック電工株式会社 Method for manufacturing vertical comb actuator
US8154784B2 (en) 2007-09-12 2012-04-10 Ricoh Company, Ltd. Optical scanning device and image forming apparatus

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