Drive detection device for gyroscope

• US 6,288,474 B1
• Filed: 05/25/2000
• Issued: 09/11/2001
• Est. Priority Date: 05/28/1999
• 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: Hasegawa, Kazuo, Ono, Yasuichi, Takai, Daisuke
• Primary Examiner(s): BUDD, MARK OSBORNE
• Application Number:
  US09/578,989
• Time in Patent Office: 474 Days
• Field of Search: 310/321, 310/322, 310/366, 310/370, 310/316.01, 310/317, 310/319, 73/505, 73/504.04, 73/504.12, 73/504.15, 73/504.16
• US Class Current: 310/319
• 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 pair of electrodes are formed on the front surface and the rear surface of each vibrator in a longitudinal direction, and dielectric polarization is performed in the direction from the front surface to the rear surface. When I/V converters constituted by operational amplifiers are connected to electrodes of the middle vibrator, the detection electrodes can be grounded to a reference potential Vref through the imaginary short circuits of the I/V converters, so that a gyroscope can be vibrated without a conventional ground electrode. Therefore, the number of electrodes of the vibrators can be reduced, and an interval size between the drive electrodes or between the detection electrodes can be assured. For this reason, sufficient dielectric polarization can be performed when a high voltage is applied.

Claims

1. A drive detection device for a gyroscope including at least one vibrator which has a pair of drive electrodes extending in a longitudinal direction on one surface and a pair of detection electrodes extending in the longitudinal direction on an opposing surface and which is dielectric-polarized in one direction between one surface and the opposing surface, comprising:

a drive system to give drive signals opposite from each other in phase to the pair of drive electrodes; and

a detection system including a pair of I/V conversion mechanisms to respectively convert current outputs detected from the pair of detection electrodes into voltage outputs and an addition mechanism to add voltage outputs of the I/V conversion mechanisms.

2. A drive detection device for a gyroscope according to claim 1, wherein dielectric polarization directions of adjacent vibrators are opposite from each other in phase.

3. A drive detection device for a gyroscope according to claim 1, wherein one surface of each vibrator is constituted by only a drive electrode, and the opposing surface is constituted by only a detection electrode.

4. A drive detection device for a gyroscope including at least one vibrator which has first and second drive electrodes extending in a longitudinal direction on one surface and first and second detection electrodes extending in the longitudinal direction on an opposing surface and which is dielectric-polarized between the surface and the opposing surface, comprising:

a circuit of a drive system to generate drive signals being in-phase to the first and second drive electrodes; and

a detection system having a pair of I/V conversion mechanisms to respectively convert current outputs detected from the first and second detection electrodes into voltage outputs and a differential amplification mechanism to subtract voltage outputs of the I/V conversion mechanisms from each other.

5. A drive detection device for a gyroscope according to claim 4, wherein a piezoelectric vibrator is formed such that a dielectric polarization direction between the first drive electrode and the first detection electrode and a dielectric polarization direction between the second dielectric electrode and the second detection electrode are opposite from each other in phase, and is formed such that a dielectric polarization direction between the first drive electrode and the second drive electrode and a dielectric polarization direction between the first detection electrode and the second detection electrode are opposite from each other in phase.

6. A drive detection device for a gyroscope according to claim 4, wherein dielectric polarization directions of adjacent vibrators are opposite from each other in phase.

7. A drive detection device for a gyroscope according to claim 4, wherein one surface of each vibrator is constituted by only a drive electrode, and the opposing surface is constituted by only a detection electrode.