Angular velocity sensor

• US 7,043,988 B2
• Filed: 09/23/2005
• Issued: 05/16/2006
• Est. Priority Date: 05/30/1995
• Status: Expired due to Fees

• Current Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Inventors: Uemura, Takeshi, Nozoe, Toshiyuki, Tamura, Masami
• Primary Examiner(s): KWOK, HELEN C
• Application Number:
  US11/233,014
• Publication Number:
  US 20060032311A1
• Time in Patent Office: 235 Days
• Field of Search: 735/041.2, 735/041.3, 735/041.4, 735/041.5, 735/041.6, 735/040.2, 735/040.4, 735/143.2, 735/142.9, 73/13.7, 73/17.7, 73/18.2
• US Class Current: 73/504.12
• CPC Class Codes: G01C 19/5607 using vibrating tuning forks double-ended tuning forks using planar vibrating masses suspended at opposite ends G01C19/5719
• CPC Class Codes: G01P 21/02 of speedometers

Abstract

An angular velocity sensor of the present invention includes a driving part for stably vibrating a driving part of a sensor element and a detector part for detecting an angular velocity of the sensor element and obtains a self diagnosis signal for a malfunction by detecting a mechanical coupling signal obtained at the detection part.

Claims

1. A circuit for amplifying outputs of an angular velocity sensor element, said sensor element having first and second sensing electrodes, said circuit comprising;

a pair of input channels to which said first and second sensing electrodes of said angular velocity sensor element are connected respectively,

a differential amplifier which amplifies a difference in outputs from said pair of input channels, and

a self-diagnosis circuit which couples a test signal to one of said pair of input channels.

2. The circuit as recited in claim 1, wherein said pair of input channels comprises a pair of charge amplifiers.

3. The circuit as recited in claim 1, wherein said pair of input channels comprises a pair of current amplifiers.

4. The circuit as recited in claim 1, wherein said angular velocity sensor element is driven by a driving signal and said test signal is a signal synchronized with said driving signal.

5. The circuit as recited in one of claims 1–

4, wherein said differential amplifier is a balanced differential amplifier.

6. An angular velocity sensor including said circuit for amplifying outputs of said angular velocity sensor element as recited in one of claims 1–

4, for detecting an abnormality of said angular velocity sensor including said sensor element.