Gyroscope and input apparatus using the same

• US 6,497,148 B1
• Filed: 09/07/2000
• Issued: 12/24/2002
• Est. Priority Date: 09/08/1999
• Status: Expired due to Fees

• Current Assignee: ALPS Electric Company Limited (Alps Alpine Co., Ltd.)
• Original Assignee: ALPS Electric Company Limited (Alps Alpine Co., Ltd.)
• Inventors: Shinohara, Eiji, Esashi, Masayoshi, Abe, Munemitsu
• Primary Examiner(s): KWOK, HELEN C
• Application Number:
  US09/657,435
• Time in Patent Office: 838 Days
• Field of Search: 735/041.2, 735/041.4, 735/041.5, 735/041.6, 735/040.4, 735/040.2, 735/143.2, 310/370, 310/321, 310/329
• US Class Current: 73/504.16
• CPC Class Codes: G01C 19/5607 using vibrating tuning forks double-ended tuning forks using planar vibrating masses suspended at opposite ends G01C19/5719

Abstract

A gyroscope of the invention is provided with a tuning fork having three legs and a support, a top side glass substrate and a bottom side glass substrate between which the tuning fork is interposed, driving movable electrodes disposed on the top surface of each leg, driving fixed electrodes disposed on the bottom surface of the top side glass substrate so as to face to the driving movable electrodes, six detection movable electrodes connected to each other in parallel disposed on the top surface of the free end of each leg, and six detection fixed electrodes connected to each other in parallel disposed on the bottom surface of the top side glass substrate so as to face to the detection movable electrodes.

Claims

1. A gyroscope comprising;

a tuning fork including a vibration member,

a base material disposed to face said vibration member,

a driving mechanism to drive and vibrate the vibration member,

a plurality of detection movable electrodes provided at a free end position on a surface of the vibration member, the surface being parallel to a displacement detection direction that is perpendicular to a vibration direction by the driving mechanism, wherein the plurality of detection movable electrodes has a width not less than a maximum amplitude of vibration of the vibration member generated in the displacement detection direction, and

a plurality of detection fixed electrodes provided on the base material disposed to face to the plurality of detection movable electrodes and to form a capacitance between said plurality of detection fixed electrodes and said plurality of detection movable electrodes, wherein the plurality of detection fixed electrodes has a width not less than the maximum amplitude of vibration of the vibration member generated in the displacement detection direction and is electrically connected to each other.

2. The gyroscope as claimed in claim 1, wherein the vibration member is comprised of conductive material, and the plurality of detection movable electrodes are provided with interposition of an insulative film formed at least on the free end portion of the vibration member.

3. The gyroscope as claimed in claim 1, wherein an end of each of the detection movable electrodes and an end of each of the detection fixed electrodes are disposed to deviate from each other by a distance not less than the maximum amplitude of the vibration member in the displacement detection direction.

4. An input apparatus provided with the gyroscope as claimed in claim 1.

5. The input apparatus as claimed in claim 4, wherein the vibration member consists of conductive material, and the plurality of detection movable electrodes are provided with interposition of an insulative film formed at least on the free end portion of the vibration member in the gyroscope.

6. The input apparatus as claimed in claim 4, wherein an end of each of the detection movable electrodes and an end of each of the detection fixed electrodes are disposed to deviate from each other by a distance not less than the maximum amplitude of the vibration member in the displacement detection direction in the gyroscope.

19. A gyroscope according to claim 1, wherein the vibration direction is perpendicular to the base material.

20. An input device comprising a gyroscope according to claim 19.

7. A gyroscope comprising;

a vibration member including a tuning fork,

a base material disposed to face said vibration member,

a driving mechanism to drive the vibration member,

a plurality of detection movable electrodes provided on surface side parallel to a displacement detection direction of a free end portion of the vibration member, each of the detection movable electrodes has a width not less than a maximum amplitude of the vibration member in the displacement detection direction, and

detection fixed electrodes comprising two electrode groups, each group of the two electrode groups comprising a plurality of electrodes, electrodes of said two electrode groups being provided on the base material facing the plurality of detection movable electrodes to form a capacitance respectively with any electrode of the plurality of detection movable electrodes, an outer end of each electrode of one electrode group out of the two electrode groups is disposed with deviation to an outside from one outer end of the detection movable electrodes that are facing said each electrode in the one electrode group by a distance not less than the maximum amplitude in the displacement detection direction, an outer end of each electrode of another electrode group out of the two electrode groups is disposed with deviation to an outside from another outer end of the detection movable electrodes that are facing said each electrode in said another electrode group by a distance not less than the maximum amplitude in the displacement detection direction, and each of which electrodes has a width equal to or larger than the maximum amplitude of the vibration member in the displacement detection direction,

wherein a difference between a sum of capacitances formed between the one electrode group out of the detection fixed electrodes and the plurality of detection movable electrodes that are facing the one electrode group and a sum of capacitances formed between the another electrode group out of the detection fixed electrodes and the plurality of detection movable electrodes that are facing the another electrode group is detected.

9. The gyroscope as claimed in claim 7, wherein a number of electrodes of the two electrode groups of the detection fixed electrodes is equal to a number of electrodes of the detection movable electrodes.

11. The gyroscope as claimed in claim 7, wherein the vibration member is comprised of conductive material, and one of the plurality of detection movable electrodes and the plurality of pairs of detection movable electrodes are provided with the interposition of an insulative film on at least the free end portion of the vibration member.

13. An input apparatus provided with the gyroscope as claimed in claim 7.

15. The input apparatus as claimed in claim 13, wherein a number of electrodes of the two electrode groups of the detection fixed electrodes is equal to a number of electrodes of the detection movable electrodes in the gyroscope.

17. The input apparatus as claimed in claim 13, wherein the vibration member is comprised of conductive material, and one of the plurality of detection movable electrodes and the plurality of pairs of detection movable electrodes are provided with the interposition of an insulative film on at least the free end portion of the vibration member in the gyroscope.

8. A gyroscope comprising;

a vibration member including a tuning fork,

a base material disposed to face said vibration member,

a driving mechanism to drive the vibration member,

a plurality of detection fixed electrodes provided on the base material to face a surface parallel to a displacement detection direction of a free end portion of the vibration member, each of the plurality of detection fixed electrodes has a width not less than a maximum amplitude of the vibration member in the displacement detection direction, and

detection movable electrodes comprising two electrode groups, each group of which two electrode groups comprising a plurality of electrodes, electrodes of said two electrode groups being disposed on both sides parallel to the displacement detection direction of the free end portion of the vibration member facing any electrode of the plurality of detection fixed electrodes to form a capacitance with the plurality of detection fixed electrodes, an outer end of each of which electrodes of the one electrode group out of the two electrode groups is disposed with deviation to an outside from one outer end of the detection fixed electrodes that are facing said each electrode of the one electrode group by a distance not less than the maximum amplitude in the displacement detection direction, an outer end of electrodes of another electrode group out of the two electrode groups is disposed with deviation to an outside from another outer end of the detection fixed electrodes that are facing said each electrode of the another electrode group by a distance not less than the maximum amplitude in the displacement detection direction, and each of which electrodes has a width equal to or larger than the maximum amplitude of the vibration member in the displacement detection direction,

wherein a difference between a sum of capacitances formed between the one electrode group out of the detection movable electrodes and the plurality of detection fixed electrodes that are facing the one electrode group and a sum of capacitances formed between the another electrode group out of the detection movable electrodes and the plurality of detection fixed electrodes that are facing the another electrode group is detected.

10. The gyroscope as claimed in claim 8, wherein a number of electrodes of the two electrode groups of the detection movable electrodes is equal to a number of electrodes of the detection fixed electrodes.

12. The gyroscope as claimed in claim 8, wherein the vibration member is comprised of conductive material, and one of the plurality of detection movable electrodes and the plurality of pairs of detection movable electrodes are provided with the interposition of an insulative film on at least the free end portion of the vibration member.

14. An input apparatus provided with the gyroscope as claimed in claim 8.

16. The input apparatus as claimed in claim 14, wherein a number of electrodes of the two electrode groups of the detection movable electrodes is equal to a number of electrodes of the detection fixed electrodes in the gyroscope.

18. The input apparatus as claimed in claim 14, wherein the vibration member is comprised of conductive material, and one of the plurality of detection movable electrodes and the plurality of pairs of detection movable electrodes are provided with the interposition of an insulative film on at least the free end portion of the vibration member in the gyroscope.