ANGULAR VELOCITY DETECTING DEVICE

• US 20090056444A1
• Filed: 06/10/2008
• Published: 03/05/2009
• Est. Priority Date: 06/22/2007
• Status: Active Grant

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: GOTO, Yasushi, JEONG, Heewon
• Granted Patent: US 7,770,451 B2
• Time in Patent Office: Days
• US Class Current: 73/504.140
• CPC Class Codes: G01C 19/5747 each sensing mass being connected to a driving mass, e.g. driving frames
• CPC Class Codes: G01C 19/5762 the sensing mass being connected to a driving mass, e.g. driving frames
• CPC Class Codes: G01P 3/22 transferred to the indicator by electric or magnetic means

Abstract

A high-performance angular rate detecting device is provided. A driving part including a drive frame and a Coriolis frame is levitated by at least two fixing beams which share a fixed end and are extending in a direction orthogonal to a driving direction, thereby vibrating the driving part. Even when a substrate is deformed by mounting or heat fluctuation, internal stress generated to the fixed beam and a supporting beam is small, thereby maintaining a vibrating state such as resonance frequency and vibration amplitude constant. Therefore, a high-performance angular rate detecting device which is robust to changes in mounting environment can be obtained.

Claims

1. An angular rate detecting device in which an x-axis in a direction on a surface of the active layer;

a y-axis perpendicular to the x-axis in the surface of the active layer; and

a z-axis perpendicular to the surface of the active layer are given to a substrate having a basement layer and an active layer on the basement layer interposing an interlayer insulating layer formed in a thickness direction, and a drive frame provided to the active layer so as to vibrate in the x-axis and a Coriolis frame provided so as to vibrate also in the y-axis following the vibration of the drive frame configure the angular rate detecting device for detecting a physical amount relating to the Coriolis force generated to the Coriolis frame when an angular rate about the z-axis is applied, the angular rate detecting device comprising;

at least two fixed beams provided to extend in opposite directions in the y-axis direction orthogonal to the vibrating direction and sharing a fixed end;

a free beam provided to extend in the x-axis direction and coupled with a free end of the fixed beam; and

at least two supporting beams provided to the free beam and extending in the y-axis direction with a predetermined space from the fixed beam, and the other free end of the supporting beam is coupled with the drive frame near the fixed end.

2. The angular rate detecting device according to claim 1,

wherein the drive frame is provided inside the Coriolis frame.

3. The angular rate detecting device according to claim 1,

wherein at least two or more sets of the fixed beam, the free beam, and the supporting beam are provided in the x-axis direction with predetermined space therebetween.

4. An angular rate detecting device having the angular rate detecting device as one unit of a sensor unit, and at least two sensor units are provided to the active layer and coupled by a linking beam, so that respective sensor units are interlocked.

5. An angular rate detecting device comprising:

a basement layer;

an interlayer provided on the basement layer;

a fixed part provided on the interlayer;

a drive frame provided to the same layer of the fixed part and suspended to the fixed part via a first beam, a second beam, a third beam, and a connecting part; and

a Coriolis frame provided to the same layer of the fixed part and suspended to the fixed part via a fourth beam,

wherein, when a direction in a surface of the basement layer is taken as an x-axis and a direction perpendicular to the x-axis in the surface of the basement layer is taken as a y-axis,

the first beam is provided to extend in the y-axis direction;

the second beam is provided to extend in the x-axis direction;

the third beam is provided to extend in the y-axis direction with a predetermined space from the first beam;

one end of the first beam is coupled with the fixed part and the other end is coupled with the second beam;

one end of the third beam is coupled with the second beam, and the other end is coupled with the connecting part; and

the connecting part is coupled with the drive frame on the x-axis as with the fixed part.

6. The angular rate detecting device according to claim 5,

wherein the first beams are provided to extend in the y-axis direction in pair symmetrically across the fixed part, and

the third beam is provided to extend in the y-axis direction in pair symmetrically across the connecting part.

7. The angular rate detecting device according to claim 5,

wherein a planer shape of the drive frame is a rectangular shape, and the fixed part, the first beam, the second beam, the third beam, and the connecting part are provided inside the rectangular.

8. The angular rate detecting device according to claim 5,

wherein a planer shape of the Coriolis frame is a rectangular shape, and the drive frame is provided inside the rectangular.

9. The angular rate detecting device according to claim 5,

wherein a length of the second beam is smaller than that of the first beam, and

a width of the second beam is larger than that of the first beam.