Device for moving a suspended weight body

• US 5,531,092 A
• Filed: 02/24/1995
• Issued: 07/02/1996
• Est. Priority Date: 12/28/1989
• Status: Expired due to Term

• Current Assignee: Kazuhiro Okada
• Original Assignee: Kazuhiro Okada
• Inventors: Okada, Kazuhiro
• Primary Examiner(s): RAEVIS, ROBERT R
• Application Number:
  US08/393,801
• Time in Patent Office: 494 Days
• Field of Search: 73/1 B, 73/1 C, 73/1 D, 73/1 DV, 73/4 R, 310/309
• US Class Current: 73/1.13
• CPC Class Codes: G01L 1/148 using semiconductive material, e.g. silicon
• CPC Class Codes: G01L 1/18 using properties of piezo-resistive materials, i.e. materials of which the ohmic resistance varies according to changes in magnitude or direction of force applied to the material
• CPC Class Codes: G01L 25/00 Testing or calibrating of apparatus for measuring force, torque, work, mechanical power, or mechanical efficiency
• CPC Class Codes: G01L 5/162 of piezoresistors
• CPC Class Codes: G01P 15/123 by piezo-resistive elements, e.g. semiconductor strain gauges
• CPC Class Codes: G01P 15/125 by capacitive pick-up
• CPC Class Codes: G01P 15/18 in two or more dimensions
• CPC Class Codes: G01P 2015/084 the mass being suspended at more than one of its sides, e.g. membrane-type suspension, so as to permit multi-axis movement of the mass
• CPC Class Codes: G01P 21/00 Testing or calibrating of apparatus or devices covered by the preceding groups

Abstract

A sensor comprises a semiconductor pellet (10) including a working portion (11) adapted to undergo action of a force, a fixed portion (13) fixed on the sensor body, and a flexible portion (13) having flexibility formed therebetween, a working body (20) for transmitting an exterted force to the working portion, and detector means (60-63) for transforming a mechanical deformation produced in the semiconductor pellet to an electric signal to thereby detect a force exerted on the working body as an electric signal. A signal processing circuit is applied to the sensor. This circuit uses analog multipliers (101-109) and analog adders/subtracters (111-113), and has a function to cancel interference produced in different directions. Within the sensor, two portions (E3, E4-8) located at positions opposite to each other and producing a displacement therebetween by action of a force are determined. By exerting a coulomb force between both the portions, the test of the sensor is carried out. Further, a pedestal (21, 22) is provided around the working body (20). The working body and the pedestal are located with a predetermined gap or spacing therebetween. A displacement of the working body is caused to limitatively fall within a predetermined range corresponding to the spacing. The working body and the pedestal are provided by cutting a same common substrate (350, 350'"'"').

Claims

1. A device for moving a suspended weight body in a direction along an X-axis in an XYZ three-dimensional coordinate system, the device comprising:

a first substrate having a first plane surface which is parallel with an XY-plane of said coordinate system, said first substrate including a working portion to which a weight body to be moved is attached, a fixed portion fixed to a device body, and a flexible portion having flexibility formed between said working portion and said fixed portion, said weight body being suspended by the first substrate;

a second substrate having a second plane surface which is opposite to said first plane surface with a predetermined distance and is fixed to said fixed portion;

a first set of two electrode layers formed on said first plane surface, wherein a first layer is located in a positive field of the X-axis and substantially has a symmetrical shape with respect to the X-axis, and a second layer is located in a negative field of the X-axis and substantially has a symmetrical shape with respect to the X-axis;

a second set of two electrode layers formed on said second plane surface, wherein first and second layers of the second set are opposite to said first and second layers of the first set, respectively; and

means for applying predetermined voltages to said first set of electrodes and said second set of electrodes to exert a coulomb force therebetween, thereby permitting said first substrate to produce a mechanical deformation to move said weight body in the X-axis direction.

2. A device as set forth in claim 1, wherein one of said first set and said second set of two electrode layers consists of an electrically singular electrode layer.

3. A device as set forth in claim 1, wherein the working portion of the first substrate and the weight body are integrated.

4. A device as set forth in claim 1, wherein charges of predetermined polarities are applied to the first and the second electrode layers of both the sets to move the weight body in the X-axis direction.

5. A device for moving a suspended weight body in a direction defined by a product of a first vector component along an X-axis and a second vector component along a Y-axis in an XYZ three-dimensional coordinate system, the device comprising:

a first substrate having a first plane surface which is parallel with an XY-plane of said coordinate system, said first substrate including a working portion to which a weight body to be moved is attached, a fixed portion fixed to a device body, and a flexible portion having flexibility formed between said working portion and said fixed portion, said weight body being suspended by the first substrate;

a second substrate having a second plane surface which is opposite to said first plane surface with a predetermined distance and is fixed to said fixed portion;

a first set of four electrode layers formed on said first plane surface, wherein a first layer is located in a positive field of the X-axis and substantially has a symmetrical shape with respect to the X-axis, a second layer is located in a negative field of the X-axis and substantially has a symmetrical shape with respect to the X-axis, a third layer is located in a positive field of the Y-axis and substantially has a symmetrical shape with respect to the Y-axis, and a fourth layer is located in a negative field of the Y-axis and substantially has a symmetrical shape with respect to the Y-axis;

a second set of four electrode layers formed on said second plane surface, wherein first to fourth layers of the second set are opposite to said first to fourth layers of the first set, respectively; and

means for applying predetermined voltages to said first set of electrodes and said second set of electrodes to exert a coulomb force therebetween, thereby permitting said first substrate to produce a mechanical deformation to move said weight body in the X-axis direction and the Y-axis direction.

6. A device as set forth in claim 5, wherein one of said first set and said second set of four electrode layers consists of an electrically singular electrode layer.

7. A device as set forth in claim 5, wherein the working portion of the first substrate and the weight body are integrated.

8. A device as set forth in claim 5, wherein charges of predetermined polarities are applied to the first and the second electrode layers of both the sets to move the weight body in the X-axis direction, and charges of predetermined polarities are applied to the third and the fourth electrode layers of both the sets to move the weight body in the Y-axis direction.

9. A device for moving a suspended weight body in a direction defined by a product of a first vector component along an X-axis and a second vector component along a Z-axis in an XYZ three-dimensional coordinate system, the device comprising:

a first substrate having a first plane surface which is parallel with an XY-plane of said coordinate system, said first substrate including a working portion to which a weight body to be moved is attached, a fixed portion fixed to a device body, and a flexible portion having flexibility formed between said working portion and said fixed portion, said weight body being suspended by the first substrate;

a second substrate having a second plane surface which is opposite to said first plane surface with a predetermined distance and is fixed to said fixed portion;

a first set of four electrode layers formed on said first plane surface, wherein a first layer is located in a positive field of the X-axis and substantially has a symmetrical shape with respect to the X-axis, a second layer is located in a negative field of the X-axis and substantially has a symmetrical shape with respect to the X-axis, a third layer is located in a positive field of the Y-axis and substantially has a symmetrical shape with respect to the Y-axis, and a fourth layer is located in a negative field of the Y-axis and substantially has a symmetrical shape with respect to the Y-axis;

a second set of four electrode layers formed on said second plane surface, wherein first to fourth layers of the second set are opposite to said first to fourth layers of the first set, respectively; and

means for applying predetermined voltages to said first set of electrodes and said second set of electrodes to exert a coulomb force therebetween, thereby permitting said first substrate to produce a mechanical deformation to move said weight body in the X-axis direction and the Z-axis direction.

10. A device as set forth in claim 9, wherein one of said first set and second set of four electrode layers consists of an electrically singular electrode layer.

11. A device as set forth in claim 9, wherein the working portion of the first substrate and the weight body are integrated.

12. A device as set forth in claim 9, wherein charges of predetermined polarities are applied to the first and the second electrode layers of both the sets to move the weight body in the X-axis direction, and charges of predetermined polarities are applied to the first, second, third and fourth electrode layers of both the sets to move the weight body in the Z-axis direction.

13. A device for moving a suspended weight body in a direction defined by a product of a first vector component along an Z-axis, a second vector component along a Y-axis and a third vector component along X-axis in an XYZ three-dimensional coordinate system, the device comprising:

a first substrate having a first plane surface which is parallel with an XY-plane of said coordinate system, said first substrate including a working portion to which a weight body to be moved is attached, a fixed portion fixed to a device body, and a flexible portion having flexibility formed between said working portion and said fixed portion, said weight body being suspended by the first substrate;

a second substrate having a second plane surface which is opposite to said first plane surface with a predetermined distance and is fixed to said fixed portion;

a first set of four electrode layers formed on said first plane surface, wherein a first layer is located in a positive field of the X-axis and substantially has a symmetrical shape with respect to the X-axis, a second layer is located in a negative field of the X-axis and substantially has a symmetrical shape with respect to the X-axis, a third layer is located in a positive field of the Y-axis and substantially has a symmetrical shape with respect to the Y-axis, and a fourth layer is located in a negative field of the Y-axis and substantially has a symmetrical shape with respect to the Y-axis;

a second set of four electrode layers formed on said second plane surface, wherein first to fourth layers of the second set are opposite to said first to fourth layers of the first set, respectively; and

means for applying predetermined voltages to said first set of electrodes and said second set of electrodes to exert a coulomb force therebetween, thereby permitting said first substrate to produce a mechanical deformation to move said weight body in the X-axis direction, the Y-axis direction and the Z-axis direction.

14. A device as set forth in claim 13, wherein one of said first set and second set of four electrode layers consists of an electrically singular electrode layer.

15. A device as set forth in claim 13, wherein the working portion of the first substrate and the weight body are integral.

16. A device as set forth in claim 13, wherein charges of predetermined polarities are applied to the first and the second electrode layers of both the sets to move the weight body in the X-axis direction, charges of predetermined polarities are applied to the third and the fourth electrode layers of both the sets to move the weight body in the Y-axis direction, and charges of predetermined polarities are applied to the first, second, third and fourth electrode layers of both the sets to move the weight body in the Z-axis direction.