Physical quantity sensor having angular speed sensor and acceleration sensor

• US 7,290,449 B2
• Filed: 03/15/2005
• Issued: 11/06/2007
• Est. Priority Date: 03/30/2004
• Status: Active Grant

• Current Assignee: DENSO Corporation
• Original Assignee: DENSO Corporation
• Inventors: Ao, Kenichi
• Primary Examiner(s): CHAPMAN JR, JOHN E
• Application Number:
  US11/079,246
• Publication Number:
  US 20050217377A1
• Time in Patent Office: 966 Days
• Field of Search: 735/040.4, 735/041.2, 735/10
• US Class Current: 73/510
• CPC Class Codes: G01C 19/5719 using planar vibrating masses driven in a translation vibration along an axis
• CPC Class Codes: G01P 15/125 by capacitive pick-up

Abstract

A physical quantity sensor includes: a substrate; an angular speed sensor disposed on the substrate; and an acceleration sensor disposed on the substrate. The angular speed sensor includes an oscillator capable of oscillating by a driving force and displaceable in accordance with a Coriolis force attributed to an angular speed of the oscillator. The acceleration sensor includes a movable portion displaceable in accordance with an acceleration applied to the acceleration sensor. The oscillator has a driving direction, which is not parallel to a displacement direction of the movable portion. The physical quantity sensor having the angular speed sensor and the acceleration sensor detects both of the angular speed and the acceleration with high accuracy.

Claims

1. A physical quantity sensor comprising:

a substrate;

an angular speed sensor disposed on the substrate; and

an acceleration sensor disposed on the substrate, wherein

the angular speed sensor includes an oscillator capable of oscillating by a driving force and displaceable in accordance with a Coriolis force attributed to an angular speed of to oscillator,

the acceleration sensor includes a movable portion displaceable in accordance with an acceleration of the acceleration sensor, and

the oscillator has a driving direction, which is not parallel to a displacement direction of the movable portion,

the oscillator of the annular speed sensor has a resonant frequency in the driving direction,

the acceleration sensor is disposed on the substrate through an adhesive layer,

the adhesive layer of the acceleration sensor has another resonant frequency, and

the resonant frequency of the oscillator in the driving direction is greater than or equal to square root of two times the resonant frequency of the adhesive layer in the displacement direction.

2. The sensor according to claim 1, wherein

the driving direction of the oscillator and the displacement direction of the movable portion provide an angle therebetween, and

the angle is in a range between 60 degrees and 120 degrees.

3. The sensor according to claim 2, wherein

the angle is substantially 90 degrees.

4. The sensor according to claim 1, wherein

the oscillator of the angular speed sensor has a resonant frequency in the driving direction,

the movable portion of the acceleration sensor has another resonant frequency in the displacement direction, and

the resonant frequency of the oscillator is equal to or larger than square root of two times the resonant frequency of the movable portion.

5. The sensor according to claim 1, wherein

the oscillator of the angular speed sensor has a resonant frequency in the driving direction,

the angular speed sensor is disposed on the substrate through an adhesive layer,

the adhesive layer of the angular speed sensor has another resonant frequency, and

the resonant frequency of the oscillator is equal to or larger than square root of two times the resonant frequency of the adhesive layer.

6. A physical quantity sensor comprising:

a mounting base;

an angular speed sensor disposed on the mounting base; and

an acceleration sensor disposed on the mounting base, wherein

the angular speed sensor includes an oscillator capable of oscillating by a driving force and capable of being displaced in accordance with a Coriolis force attributed to an angular speed applied to the angular speed sensor,

the acceleration sensor includes a movable portion displaceable in accordance with an acceleration applied to the acceleration sensor,

the oscillator of the angular speed sensor has a resonant frequency in a driving direction,

the movable portion of the acceleration sensor has another resonant frequency in a displacement direction which is not parallel to the direction—

has been inserted after, and

the resonant frequency of the oscillator in the driving direction is equal to or larger than square root of two times the resonant frequency of the movable portion in the displacement direction.

7. A physical quantity sensor comprising:

a mounting base;

an angular speed sensor disposed on the mounting base; and

an acceleration sensor disposed on the mounting base, wherein

the angular speed sensor includes an oscillator capable of oscillating by a driving force in a driving direction and capable of being displaced in accordance with a Coriolis force attributed to an angular speed applied to the angular speed sensor,

the acceleration sensor includes a movable portion displaceable in accordance with an acceleration applied to the acceleration sensor in a displacement direction which is not parallel to the driving direction—

has been inserted after,

the oscillator of the angular speed sensor has a resonant frequency in the driving direction,

the angular speed sensor is disposed on the mounting base through an adhesive layer,

the adhesive layer of the angular speed sensor has another resonant frequency, and

the resonant frequency of the oscillator in the driving direction is equal to or larger than square root of two times the resonant frequency of the adhesive layer in the displacement direction.

8. A physical quantity sensor comprising:

a mounting base;

an angular speed sensor disposed on the mounting base; and

an acceleration sensor disposed on the mounting base, wherein

the angular speed sensor includes an oscillator capable of oscillating by a driving force in a driving direction and capable of being displaced in accordance with a Coriolis force attributed to an angular speed applied to the oscillator,

the acceleration sensor includes a movable portion displaceable in accordance with an acceleration applied to the acceleration sensor in a displacement direction which is not parallel to the driving direction,

the oscillator of the angular speed sensor has a resonant frequency in the driving direction,

the acceleration sensor is disposed on the mounting base through an adhesive layer,

the adhesive layer of the acceleration sensor has another resonant frequency, and

the resonant frequency of the oscillator in the driving direction is equal to or larger than square root of two times the resonant frequency of the adhesive layer in the displacement direction.