Angular velocity sensor, electronic apparatus, and mobile object

• US 10,119,823 B2
• Filed: 04/17/2015
• Issued: 11/06/2018
• Est. Priority Date: 04/22/2014
• Status: Active Grant

• Current Assignee: Seiko Epson Corporation (Seiko Group)
• Original Assignee: Seiko Epson Corporation (Seiko Group)
• Inventors: Takizawa, Teruo
• Primary Examiner(s): Caputo, Lisa
• Assistant Examiner(s): Campbell, Irving A
• Application Number:
  US14/689,450
• Publication Number:
  US 20150300821A1
• Time in Patent Office: 1,299 Days
• Field of Search: 7350412, 181121
• CPC Class Codes: G01C 19/574 the devices having two sensing masses in anti-phase motion

Abstract

An angular velocity sensor includes a substrate; a plurality of mass units which is disposed above the substrate; respective coupling units which couple the respective mass units (a first mass unit and a third mass unit, the third mass unit and a second mass unit, the second mass unit and a fourth mass unit, and a fourth mass unit and the first mass unit) adjacent to each other, among the plurality of mass units; and respective drive units which are disposed above the substrate and are connected to the respective coupling units, and the respective drive units drive the respective mass units (the first mass unit and the third mass unit, the third mass unit and the second mass unit, the second mass unit and the fourth mass unit, and the fourth mass unit and the first mass unit) adjacent to each other through the respective coupling units.

Claims

1. An angular velocity sensor comprising:

a substrate;

a plurality of mass units which are disposed above the substrate;

a plurality of coupling units which couple the mass units that are adjacent to each other, among the plurality of mass units, the adjacent mass units being connected to opposing ends of one of the coupling units; and

a plurality of drive units which are disposed above the substrate and are connected to the coupling units,

each of the plurality of drive units having a fixing unit fixed to the substrate, wherein the plurality of drive units respectively drive the mass units that are adjacent to each other through the plurality of coupling units using the fixing unit as a center of the motion, and

each of the plurality of drive units is connected to one of the plurality of coupling units through a moving unit at a location on the coupling unit between the opposing ends.

2. The angular velocity sensor according to claim 1,

wherein the plurality of mass units includes a first mass pair in which two of the mass units are disposed so as to face each other along a first axis, and a second mass pair in which the other two of the mass units are disposed so as to face each other along a second axis that intersects the first axis in a planar view, and

wherein the drive units drive the respective mass units such that the second mass pair is displaced in a direction that separates the pair from each other, when the first mass pair is displaced in a direction that brings the pair toward each other, and such that the second mass pair is displaced in a direction that brings the pair toward each other, when the first mass pair is displaced in a direction that separates the pair from each other.

3. The angular velocity sensor according to claim 2,

wherein at least one of the mass units of the first mass pair includes a first detection unit which detects angular velocity of a second axis rotation,

wherein at least one of the mass units of the second mass pair includes a second detection unit which detects angular velocity of a first axis rotation, and

wherein at least one mass unit of at least one of the first mass pair and the second mass pair includes a third detection unit which detects angular velocity of a third axis rotation which intersects a flat plane along the first axis and the second axis.

4. The angular velocity sensor according to claim 3,

wherein each of the coupling units is formed in an arc shape having a center between the mass units that are adjacent to each other,

wherein each of the drive units includes a fixing unit that includes the center of the arc shape and is fixed to the substrate and a moving unit which connects the fixing unit to one of the coupling units, and

wherein the moving unit and the coupling unit can rotate using the fixing unit as a center.

5. The angular velocity sensor according to claim 4,

wherein each of the drive units includes a fixing electrode which is provided above the substrate and a moving electrode which is provided in the moving unit,

wherein the fixing electrode and the moving electrode include electrode fingers which mesh with each other and have a comb tooth shape, and

wherein the electrode fingers are formed in an arc shape having the fixing unit as a center.

6. The angular velocity sensor according to claim 3,

wherein each of the coupling units includes a stress reduction unit in a connection unit between the coupling unit and the mass unit to which the coupling unit is attached.

7. The angular velocity sensor according to claim 3,

wherein at least one of the plurality of mass units includes a monitoring unit which monitors displacement of the mass unit at the time of driving.

8. The angular velocity sensor according to claim 2,

wherein each of the coupling units is formed in an arc shape having a center between the mass units that are adjacent to each other,

wherein each of the drive units includes a fixing unit that includes the center of the arc shape and is fixed to the substrate and a moving unit which connects the fixing unit to one of the coupling units, and

wherein the moving unit and the coupling unit can rotate using the fixing unit as a center.

9. The angular velocity sensor according to claim 8,

wherein each of the drive units includes a fixing electrode which is provided above the substrate and a moving electrode which is provided in the moving unit,

wherein the fixing electrode and the moving electrode include electrode fingers which mesh with each other and have a comb tooth shape, and

wherein the electrode fingers are formed in an arc shape having the fixing unit as a center.

10. The angular velocity sensor according to claim 2,

wherein each of the coupling units includes a stress reduction unit in a connection unit between the coupling unit and the mass unit to which the coupling unit is attached.

11. The angular velocity sensor according to claim 2,

wherein at least one of the plurality of mass units includes a monitoring unit which monitors displacement of the mass unit at the time of driving.

12. The angular velocity sensor according to claim 1,

wherein at least one of the plurality of mass units includes a monitoring unit which monitors displacement of the mass unit at the time of driving.

13. The angular velocity sensor according to claim 12,

wherein each of the coupling units is formed in an arc shape having a center between the mass units that are adjacent to each other,

wherein each of the drive units includes a fixing unit that includes the center of the arc shape and is fixed to the substrate and a moving unit which connects the fixing unit to one of the coupling units, and

wherein the moving unit and the coupling unit can rotate using the fixing unit as a center.

14. The angular velocity sensor according to claim 13,

wherein each of the drive units includes a fixing electrode which is provided above the substrate and a moving electrode which is provided in the moving unit,

wherein the fixing electrode and the moving electrode include electrode fingers which mesh with each other and have a comb tooth shape, and

wherein the electrode fingers are formed in an arc shape having the fixing unit as a center.

15. The angular velocity sensor according to claim 1,

wherein each of the coupling units is formed in an arc shape having a center between the mass units that are adjacent to each other,

wherein each of the drive units includes a fixing unit that includes the center of the arc shape and is fixed to the substrate and a moving unit which connects the fixing unit to one of the coupling units, and

wherein the moving unit and the coupling unit can rotate using the fixing unit as a center.

16. The angular velocity sensor according to claim 15,

wherein each of the drive units includes a fixing electrode which is provided above the substrate and a moving electrode which is provided in the moving unit,

wherein the fixing electrode and the moving electrode include electrode fingers which mesh with each other and have a comb tooth shape, and

wherein the electrode fingers are formed in an arc shape having the fixing unit as a center.

17. The angular velocity sensor according to claim 1,

wherein each of the coupling units includes a stress reduction unit in a connection unit between the coupling unit and the mass unit to which the coupling unit is attached.

18. An electronic apparatus comprising:

the angular velocity sensor according to claim 1.

19. A mobile object comprising:

the angular velocity sensor according to claim 1.

20. An angular velocity sensor comprising:

a substrate;

a plurality of mass units which are disposed above the substrate;

a plurality of coupling units which couple the mass units that are adjacent to each other, among the plurality of mass units, the adjacent mass units being connected to opposing ends of one of the coupling units;

a plurality of drive units which are disposed above the substrate; and

each of the plurality of drive units having a fixing unit fixed to the substrate,

wherein each of the plurality of drive units is connected to a corresponding one of the coupling units respectively, and

each of the plurality of drive units directly drives the corresponding one of the plurality of coupling units to vibrate the mass units through the corresponding coupling unit using the fixing unit as a center of the motion.

21. An angular velocity sensor comprising:

a substrate;

a first mass unit connected to a first fixing unit via a first spring, the first fixing unit fixed to the substrate;

a second mass unit connected to a second fixing unit via a second spring, the second fixing unit fixed to the substrate;

a first coupling unit connecting the first mass unit and the second mass unit;

a first drive unit connected to a third fixing unit fixed to the substrate and connected to the first coupling unit;

wherein

the first drive unit directly drives the first coupling unit to vibrate the first mass unit and the second mass unit using the first fixing unit as a center of motion.

22. The angular velocity sensor according to claim 21 comprising:

a third mass unit connected to a fourth fixing unit via a third spring, the fourth fixing unit fixed to the substrate;

a fourth mass unit connected to a fifth fixing unit via a fourth spring, the fifth fixing unit fixed to the substrate;

a second coupling unit connecting the second mass unit and the third mass unit;

a third coupling unit connecting the third mass unit and the fourth mass unit;

a fourth coupling unit connecting the fourth mass unit and the first mass unit;

a second drive unit connected to a sixth fixing unit fixed to the substrate and connected to the second coupling unit;

a third drive unit connected to a seventh fixing unit fixed to the substrate and connected to the third coupling unit; and

a fourth drive unit connected to an eighth fixing unit fixed to the substrate and connected to the fourth coupling unit, wherein

the second drive unit directly drives the second coupling unit to vibrate the second mass unit and the third mass unit,

the third drive unit directly drives the third coupling unit to vibrate the third mass unit and the fourth mass unit, and

the fourth drive unit directly drives the fourth coupling unit to vibrate the fourth mass unit and the first mass unit.