Angular velocity detecting device

• US 7,770,451 B2
• Filed: 06/10/2008
• Issued: 08/10/2010
• Est. Priority Date: 06/22/2007
• Status: Expired due to Fees

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Goto, Yasushi, Jeong, Heewon
• Primary Examiner(s): Williams; Hezron
• Assistant Examiner(s): Shah; Samir M
• Application Number:
  US12/136,759
• Publication Number:
  US 20090056444A1
• Time in Patent Office: 791 Days
• Field of Search: 735/040.1, 735/040.2, 735/040.3, 735/040.4, 735/041.2, 735/140.1, 735/140.2, 735/143.8, 735/041.4
• US Class Current: 73/504.14
• 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 direction on a surface of an active layer, a y-axis direction perpendicular to the x-axis direction on the surface of the active layer, and a z-axis direction perpendicular to the surface of the active layer are given to a substrate having a basement layer and the active layer on the basement layer interposing an interlayer insulating layer formed in a thickness direction;

and wherein a drive frame provided on the active layer so as to vibrate in the x-axis direction and a Coriolis frame provided so as to vibrate also in the y-axis direction following the vibration of the drive frame configure the angular rate detecting device for detecting a physical amount relating to a Coriolis force generated to the Coriolis frame when an angular rate about the z-axis direction 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 substrate by a fixed end between said fixed beams;

at least two free beams provided to extend in the x-axis direction and each coupled with a free end of at least a respective one of said fixed beams; and

at least two supporting beams extending in the y-axis direction with predetermined spaces from said fixed beams, wherein each of said supporting beams has one end coupled with a respective one of the free beams and another end 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 said fixed beams, said free beams, and said supporting beams are provided in the x-axis direction with predetermined spaces therebetween.

4. An angular rate detecting apparatus having the angular rate detecting device of claim 1 as one unit of a sensor unit, and at least two such sensor units are provided on the active layer and coupled by a linking beam, so that said sensor units are interlocked.

5. The angular rate detecting device according to claim 1, wherein the fixed end is shared by said fixed beams.

6. 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 on the same layer as the fixed part and suspended to from the fixed part via a first beam, a second beam, a third beam, and a connecting part; and

a Coriolis frame provided on the same layer as the fixed part and suspended from the fixed part via a fourth beam,

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

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 another end of the first beam is coupled with the second beam;

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

the connecting part extends in the x-axis direction and the connecting part is coupled with the drive frame.

7. The angular rate detecting device according to claim 6, further comprising an additional first beam, an additional second beam, and an additional third beam,

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

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

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

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

one end of the additional third beam is coupled with the additional second beam and another end of the additional third beam is coupled with the connecting part;

the first beam and the additional first beam are provided to extend in the y-axis direction symmetrically across the fixed part, and

the third beam and the additional third beam are provided to extend in the y-axis direction symmetrically across the connecting part.

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

wherein a planar 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 shape.

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

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

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

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

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