Physical quantity detection vibrator element, physical quantity detection apparatus, electronic apparatus, and moving object

Patent metadata

Field	Value
Publication number	US-10072928-B2
Application number	US-201615336404-A
Country	US
Kind code	B2
Filing date	Oct 27, 2016
Priority date	Oct 28, 2015
Publication date	Sep 11, 2018
Grant date	Sep 11, 2018

Abstract

A vibrator element has a detection arm that performs a drive vibration in a Z-axis direction, and performs a detection vibration in an X-axis direction when an angular velocity is applied thereto The vibrator element also has first, second, third, and fourth electrode portions and first, second, third, and fourth ground electrode portions provided on a detection arm. Further, a signal generated between the first electrode portion and the first ground electrode portion and a signal generated between the second electrode portion and the second ground electrode portion are in opposite phase in a drive vibration and in phase in a detection vibration. Furthermore, a signal generated between the third electrode portion and the third ground electrode portion and a signal generated between the fourth electrode portion and the fourth ground electrode portion are in opposite phase in the drive vibration and in phase in the detection vibration.

First claim

What is claimed is:

1. A physical quantity detection vibrator element comprising:
a detection arm that includes a piezoelectric material, performs a drive vibration in a first direction, and performs a detection vibration in second direction orthogonal to the first direction when a physical quantity is applied thereto; and
a first detection signal electrode, a second detection signal electrode, and a reference potential electrode provided on the detection arm;
wherein:
the first detection signal electrode includes a first electrode portion and a second electrode portion;
the second detection signal electrode includes a third electrode portion and a fourth electrode portion;
the reference potential electrode includes:
(a) a first reference potential electrode portion at a reference potential with respect to the first electrode portion;
(b) a second reference potential electrode portion at the reference potential with respect to the second electrode portion;
(c) a third reference potential electrode portion at the reference potential with respect to the third electrode portion; and
(d) a fourth reference potential electrode portion at the reference potential with respect to the fourth electrode portion;

a first signal generated between the first electrode portion and the first reference potential electrode portion and a second signal generated between the second electrode portion and the second reference potential electrode portion are in opposite phase with each other when the drive vibration is performed and in phase with each other when the detection vibration is performed; and
a third signal generated between the third electrode portion and the third reference potential electrode portion and a fourth signal generated between the fourth electrode portion and the fourth reference potential electrode portion are in opposite phase with each other when the drive vibration is performed and in phase with each other when the detection vibration is performed.

2. The physical quantity detection vibrator element according to claim 1 , wherein a first plane is defined normal the first direction and the detection arm further includes:
a first projection portion projecting away from the first plane on one side of the first plane;
a second projection portion projecting away from the first plane on the other side of the first plane;
a third projection portion projecting away from the first plane on the one side of the first plane beside the first projection portion; and
a fourth projection portion projecting away from the first plane on the other side of the first plane beside the second projection portion,
wherein the first electrode portion and the first reference potential electrode portion are provided with the first projection portion in between,
the second electrode portion and the second reference potential electrode portion are provided with the second projection portion in between,
the third electrode portion and the third reference potential electrode portion are provided with the third projection portion in between, and
the fourth electrode portion and the fourth reference potential electrode portion are provided with the fourth projection portion in between.

3. The physical quantity detection vibrator element according to claim 1 , further comprising:
a pair of drive arms provided with the detection arm in between; and
a base part connected to the detection arm and to the pair of drive arms.

4. The physical quantity detection vibrator element according to claim 3 , further comprising a second detection arm with the base part located in between the detection arms.

5. The physical quantity detection vibrator element according to claim 3 , wherein a first plane is defined normal the first direction, a second plane is defined normal the second direction, and each of the drive arms includes:
a drive arm first principal surface provided on one side of the first plane;
a drive arm second principal surface provided on the other side of the first plane,
a drive arm first side surface provided on one side of the second plane;
a drive arm second side surface provided on the other side of the second plane;
a drive arm first groove portion provided in the drive arm first principal surface;
a drive arm second groove portion provided in the drive arm second principal surface;
a first step portion located in the drive arm first groove portion on the one side of the second plane and connecting the drive arm first principal surface and the drive arm first side surface; and
a second step portion located in the drive arm second groove portion on the other side of the second plane and connecting the drive arm second principal surface and the drive arm second side surface,
a tip end of the first stepped portion in a third direction orthogonal to the first direction and second direction is located closer to a tip end side of the drive arm than a tip end of the drive arm first groove portion in the third direction; and
a tip end of the second stepped portion in the third direction is located closer to a tip end side of the drive arm than a tip end of the drive arm second groove portion in the third direction.

6. A physical quantity detection apparatus comprising:
the physical quantity detection vibrator element according to claim 1 ; and
a circuit electrically connected to the physical quantity detection vibrator element.

7. An electronic apparatus comprising the physical quantity detection vibrator element according to claim 1 .

8. A moving object comprising the physical quantity detection vibrator element according to claim 1 .

9. The physical quantity detection vibrator element according to claim 1 , further comprising:
a base part;
a pair of the detection arms extending from the base part in opposite directions along a third direction orthogonal to the first direction and second direction;
a pair of connecting arms extend from the base in opposite directions parallel to the second plane;
a first pair of drive arms extend from one connecting arm in opposite directions parallel to the first plane; and
a second pair of drive arms extend from the other of the pair of connecting arms in opposite directions to each other along the first plane.

10. The physical quantity detection vibrator element according to claim 9 , further comprising:
a first weight portion provided on a surface of the one detection arms on one side of the first plane; and
a second weight portion provided on a surface of the other detection arms on the other side of the first plane.

11. A physical quantity detection vibrator element comprising:
a detection arm that includes a piezoelectric material, performs a drive vibration in a first direction, and performs a detection vibration in a second direction orthogonal to the first directions when a physical quantity is applied thereto; and
a first detection signal electrode and a second detection signal electrode provided on the detection arm;
wherein:
the first detection signal electrode includes a first electrode portion and a second electrode portion;
the second detection signal electrode includes a third electrode portion and a fourth electrode portion;
a signal generated between the first electrode portion and the third electrode portion and a signal generated between the second electrode portion and the third electrode portion are in opposite phase with each other when the drive vibration is performed and in phase with each other when the detection vibration is performed; and
a signal generated between the first electrode portion and the fourth electrode portion and a signal generated between the second electrode portion and the fourt

Assignees

• Seiko Epson Corp

Inventors

• Ishii Masahiro
• Yamaguchi Keiichi
• Kikuchi Takayuki

Classifications

• G01C19/5649

  Signal processing · CPC title

• G01C19/5656 Primary

  the devices involving a micromechanical structure · CPC title

• G01C19/56 Primary

  Turn-sensitive devices using vibrating masses, e.g. vibratory angular rate sensors based on Coriolis forces · CPC title

• G01C19/5614 Primary

  Signal processing · CPC title

• H01L41/1132

  Electricity · mapped topic