Angular velocity acquisition device and electronic component for acquiring angular velocity

Patent metadata

Field	Value
Publication number	US-2017268878-A1
Application number	US-201615243511-A
Country	US
Kind code	A1
Filing date	Aug 22, 2016
Priority date	Mar 16, 2016
Publication date	Sep 21, 2017
Grant date	—

Abstract

An angular velocity acquisition device includes a movable body, a drive electrode to which a drive voltage is applied to vibrate the movable body in a first direction, at least one stopper that stops the movable body at a predetermined position, a hold electrode which receives a hold voltage to hold the movable body at the predetermined position, a detection unit that detects a predetermined physical quantity depending on an amplitude of the vibration of the movable body in a second direction based on a Coriolis force acting on the movable body that vibrates in the first direction, and an angular velocity calculation unit that calculates an angular velocity of the movable body based on the predetermined physical quantity detected by the detection unit.

First claim

What is claimed is:

1 . An angular velocity acquisition device comprising:
a movable body; a drive electrode, configured to receive a drive voltage to vibrate the movable body in a first direction; at least one stopper configured to stop the movable body at a predetermined position; a hold electrode configured to receive a hold voltage to hold the movable body at the predetermined position; a detection unit configured to detect a predetermined physical quantity depending on an amplitude of the vibration of the movable body in a second direction based on a Coriolis force acting on the movable body as it vibrates in the first direction; and an angular velocity calculation unit configured to calculate an angular velocity of the movable body based on the predetermined physical quantity detected by the detection unit.

2 . The device according to claim 1 ,
wherein the predetermined physical quantity is a physical quantity based on a capacitance between a movable electrode unit located in the movable body and a fixed electrode unit located in the vicinity of the movable electrode unit.

3 . The device according to claim 1 ,
wherein when the movable body is held in the predetermined position, the movable body is in contact with the at least one stopper and is not in contact with the hold electrode.

4 . The device according to claim 1 ,
wherein the detection unit is configured to detect the predetermined physical quantity based on the Coriolis force acting on the movable body when the vibration in the second direction is in a non-steady state.

5 . The device according to claim 1 , wherein the detection unit is configured to detect the predetermined physical quantity when the movable body is freely vibrated in the first direction.

6 . The device according to claim 1 , wherein the hold electrode is configured to release the movable body, and upon release, the movable body is configured to vibrate in the second direction in a non-steady state condition and a steady state condition, and
the detection unit is configured to detect the predetermined physical quantity based on the Coriolis force acting on the movable body when the vibration in the second direction is in a non-steady state condition.

7 . The device according to claim 6 , wherein the predetermined physical quantity is a physical quantity based on a capacitance between a movable electrode unit and a fixed electrode unit provided in the vicinity of the movable electrode unit.

8 . The device according to claim 6 , wherein when the movable body is held in the predetermined position, the movable body is in contact with the at least one stopper and is not in contact with the hold electrode.

9 . The device according to claim 1 , wherein the hold voltage is applied to the hold electrode when the amplitude of the vibration of the movable body in the first direction reaches a peak.

10 . The device according to claim 1 , wherein the movable body has a plurality of protrusion portions, the hold electrode has a plurality of protrusion portions, and the protrusion portions of the movable body and the protrusion portions of the hold electrode are interdigitated.

11 . An electronic component for acquiring an angular velocity comprising:
a movable body; a drive electrode configured to receive a drive voltage to vibrate the movable body in a first direction; at least one stopper configured to stop the movable body at a predetermined position; and a hold electrode configured to receive a hold voltage to hold the movable body at the predetermined position, wherein the movable body includes a movable electrode unit configured to detect a predetermined physical quantity depending on amplitude of the vibration of the movable body in a second direction based on Coriolis force acting on the movable body vibrating in the first direction.

12 . The component according to claim 11 ,
wherein the movable body has a plurality of protrusion portions and the hold electrode has a plurality of protrusion portions, and wherein the protrusion portions of the movable body and the protrusion portions of the hold electrode are interdigitated.

13 . The component according to claim 11 ,
wherein when the movable body is held in the predetermined position, the movable body is in contact with the at least one stopper and is not in contact with the hold electrode.

14 . The component according to claim 11 ,
wherein the detection unit is configured to detect the predetermined physical quantity based on the Coriolis force acting on the movable body when the vibration in the second direction is in a non-steady state.

15 . The component according to claim 11 , wherein the detection unit is configured to detect the predetermined physical quantity when the movable body is freely vibrated in the first direction.

16 . The component according to claim 11 , wherein the hold electrode is configured to release the movable body, and upon release, the movable body is configured to vibrate in the second direction in a non-steady state condition and a steady state condition, and
the detection unit is configured to detect the predetermined physical quantity based on the Coriolis force acting on the movable body when the vibration in the second direction is in a non-steady state condition.

17 . The component according to claim 11 , wherein the hold voltage is applied to the hold electrode when the amplitude of the vibration of the movable body in the first direction reaches a peak.

18 . The component according to claim 11 , in which the movable body has a plurality of protrusion portions, the hold electrode has a plurality of protrusion portions, and the protrusion portions of the movable body and the protrusion portions of the hold electrode are interdigitated.

19 . A method of detecting angular velocity, comprising:
providing, on a substrate,
a movable body;
a drive electrode, configured to receive a drive voltage to vibrate the movable body in a first direction;
at least one stopper configured to stop the movable body at a predetermined position; and
a hold electrode configured to receive a hold voltage to hold the movable body at the predetermined position;
providing a detection unit configured to detect a predetermined physical quantity depending on an amplitude of the vibration of the movable body in a second direction based on a Coriolis force acting on the movable body as it vibrates in the first direction; and providing an angular velocity calculation unit configured to calculate an angular velocity of the movable body based on the predetermined physical quantity detected by the detection unit.

20 . The method of claim 19 , further comprising:
providing a hold voltage to hold the movable body at the predetermined position; releasing the hold voltage to release the movable body from the predetermined position, whereby the movable body initially vibrates in a non-steady state condition and then will vibrate in a non-steady state condition; detecting, with the detection unit, the physical property while the movable body is vibrating in the steady state condition; and applying the hold voltage to the hold electrode before the movable body begins vibrating at the steady state condition.

Assignees

• Toshiba Kk

Inventors

• Yamamoto Haruka
• Tomizawa Yasushi
• Ikehashi Tamio

Classifications

• G01C19/5733

  Structural details or topology · CPC title

• B81B3/0054

  For holding or placing an element in a given position · CPC title

• G01C19/5762 Primary

  the sensing mass being connected to a driving mass, e.g. driving frames · CPC title

• G01C19/56 Primary

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