U.S. patent application number 12/160237 was filed with the patent office on 2009-03-12 for inertial force sensor.
This patent application is currently assigned to MATSUSHITA ELECTRIC INDUSTRIAL CO., LTD.. Invention is credited to Hiroyuki Aizawa, Yohei Ashimori, Takami Ishida, Hideo Ohkoshi, Satoshi Ohuchi, Ichirou Satou, Jiro Terada.
Application Number | 20090064783 12/160237 |
Document ID | / |
Family ID | 38309130 |
Filed Date | 2009-03-12 |
United States Patent
Application |
20090064783 |
Kind Code |
A1 |
Ohuchi; Satoshi ; et
al. |
March 12, 2009 |
INERTIAL FORCE SENSOR
Abstract
An inertial force sensor includes a detecting device which
detects an inertial force, the detecting device having a first
orthogonal arm and a supporting portion, the first orthogonal arm
having a first arm and a second arm fixed in a substantially
orthogonal direction, and the supporting portion supporting the
first arm. The second arm has a folding portion. In this
configuration, there is provided a small inertial force sensor
which realizes detection of a plurality of different inertial
forces and detection of inertial forces of a plurality of detection
axes.
Inventors: |
Ohuchi; Satoshi; (Hyogo,
JP) ; Aizawa; Hiroyuki; (Osaka, JP) ; Terada;
Jiro; (Osaka, JP) ; Ishida; Takami; (Osaka,
JP) ; Satou; Ichirou; (Osaka, JP) ; Ohkoshi;
Hideo; (Osaka, JP) ; Ashimori; Yohei; (Osaka,
JP) |
Correspondence
Address: |
PEARNE & GORDON LLP
1801 EAST 9TH STREET, SUITE 1200
CLEVELAND
OH
44114-3108
US
|
Assignee: |
MATSUSHITA ELECTRIC INDUSTRIAL CO.,
LTD.
Osaka
JP
|
Family ID: |
38309130 |
Appl. No.: |
12/160237 |
Filed: |
January 22, 2007 |
PCT Filed: |
January 22, 2007 |
PCT NO: |
PCT/JP2007/050901 |
371 Date: |
July 8, 2008 |
Current U.S.
Class: |
73/514.15 |
Current CPC
Class: |
G01C 19/574 20130101;
G01C 19/5607 20130101; G01P 15/18 20130101; G01C 19/5642 20130101;
G01P 15/097 20130101; G01C 19/56 20130101 |
Class at
Publication: |
73/514.15 |
International
Class: |
G01P 15/097 20060101
G01P015/097 |
Foreign Application Data
Date |
Code |
Application Number |
Jan 24, 2006 |
JP |
2006-014852 |
Jan 24, 2006 |
JP |
2006-014854 |
Jan 24, 2006 |
JP |
2006-014856 |
Jan 24, 2006 |
JP |
2006-014858 |
Jan 24, 2006 |
JP |
2006-014859 |
Claims
1. An inertial force sensor comprising: a detecting device which
detects an inertial force, wherein the detecting device includes:
two first orthogonal arms, each of which has a first arm and a
second arm and is formed by fixing the first arm and the second arm
in a substantially orthogonal direction; and a supporting portion
which supports the first arm, and wherein the second arm has a
folding portion which folds the second arm.
2. The inertial force sensor according to claim 1, wherein the
second arm is folded at the folding portion and confronted with the
first arm.
3. The inertial force sensor according to claim 2, wherein the
first arm and the supporting portion are arranged on a
substantially identical straight line.
4. The inertial force sensor according to claim 2, wherein an end
of the second arm is driven and oscillated in a direction
confronting the first arm, and wherein an angular velocity is
detected by detecting distortion of the first arm or the second
arm.
5. The inertial force sensor according to claim 2, wherein
acceleration is detected by detecting distortion of the first arm
or the second arm.
6. The inertial force sensor according to claim 2, wherein the
detecting device further includes a weight portion formed at an end
of the second arm.
7. The inertial force sensor according to claim 2, wherein an end
of the second arm is folded in meander shape.
8. The inertial force sensor according to claim 1, wherein the
detecting device further includes two fixing arms which are fixed
to the supporting portion and fixed to a mounting substrate on
which the detecting device is to be mounted, wherein the fixing arm
is a second orthogonal arm, which has a third arm and a fourth arm
and is formed by fixing the third arm and the fourth arm in a
substantially orthogonal direction, wherein the third arm is
supported by the supporting portion, and wherein the fixing arm is
fixed to the mounting substrate by the fourth arm.
9. The inertial force sensor according to claim 8, wherein the
second arm is folded at the folding portion and confronted with the
second arm.
10. The inertial force sensor according to claim 8, wherein the
first arm and the supporting portion are arranged on a
substantially identical straight line, wherein the third arm and
the supporting portion are arranged on a substantially identical
straight line, and wherein the first arm and the third arm are
arranged in a substantially orthogonal direction.
11. The inertial force sensor according to claim 8, wherein an end
of the second arm is driven and oscillated in a direction
confronting the first arm, and wherein an angular velocity is
detected by detecting distortion of at least one of the first arm,
the second arm, the third arm, and the fourth arm.
12. The inertial force sensor according to claim 8, wherein
acceleration is detected by detecting distortion of at least one of
the first arm, the second arm, the third arm, and the fourth
arm.
13. The inertial force sensor according to claim 8, wherein the
detecting device further includes a weight portion formed at an end
of the second arm.
14. The inertial force sensor according to claim 8, wherein an end
of the second arm is folded in meander shape.
15. The inertial force sensor according to claim 1, wherein the
detecting device further includes two fixing arms which are fixed
to the supporting portion and fixed to a mounting substrate on
which the detecting device is to be mounted, and wherein the second
arm is folded at the folding portion and confronted with the second
arm.
16. The inertial force sensor according to claim 15, wherein the
first arm and the supporting portion are arranged on a
substantially identical straight line, wherein the fixing arm and
the supporting portion are arranged on a substantially identical
straight line, and wherein the first arm and the fixing arm are
arranged in a substantially orthogonal direction.
17. The inertial force sensor according to claim 15, wherein an end
of the second arm is driven and oscillated in a direction
confronting the second arm, and wherein an angular velocity is
detected by detecting distortion of at least one of the first arm,
the second arm, and the fixing arm.
18. The inertial force sensor according to claim 15, wherein
acceleration is detected by detecting distortion of at least one of
the first arm, the second arm, and the fixing arm.
19. The inertial force sensor according to claim 15, wherein the
detecting device further includes a weight portion formed at an end
of the second arm.
20. The inertial force sensor according to claim 15, wherein an end
of the second arm is folded in meander shape.
21. The inertial force sensor according to claim 1, wherein the
detecting device further includes two fixing arms which are fixed
to the supporting portion and fixed to a mounting substrate on
which the detecting device is to be mounted, wherein the fixing arm
is a second orthogonal arm, which has a third arm and a fourth arm
and is formed by fixing the third arm and the fourth arm in a
substantially orthogonal direction, wherein at least a part of the
third arm serves as the first arm, and wherein the fixing arm is
fixed to the mounting substrate by the fourth arm.
22. The inertial force sensor according to claim 21, wherein the
second arm is folded at the folding portion and confronted with the
second arm.
23. The inertial force sensor according to claim 21, wherein the
third arm and the supporting portion are arranged on a
substantially identical straight line.
24. The inertial force sensor according to claim 21, wherein an end
of the second arm is driven and oscillated in a direction
confronting the second arm, and wherein an angular velocity is
detected by detecting distortion of at least one of the first arm,
the second arm, the third arm, and the fourth arm.
25. The inertial force sensor according to claim 21, wherein
acceleration is detected by detecting distortion of at least one of
the first arm, the second arm, the third arm, and the fourth
arm.
26. The inertial force sensor according to claim 21, wherein the
detecting device further includes a weight portion formed at an end
of the second arm.
27. The inertial force sensor according to claim 21, wherein an end
of the second arm is folded in meander shape.
28. The inertial force sensor according to claim 1, wherein the
detecting device further includes two fixing arms which are fixed
to the supporting portion and fixed to a mounting substrate on
which the detecting device is to be mounted, and wherein at least a
part of the fixing arm serves as the first arm.
29. The inertial force sensor according to claim 28, wherein the
second arm is folded at the folding portion and confronted with the
second arm.
30. The inertial force sensor according to claim 28, wherein the
fixing arm and the supporting portion are arranged on a
substantially identical straight line.
31. The inertial force sensor according to claim 28, wherein an end
of the second arm is driven and oscillated in a direction
confronting the second arm, and wherein an angular velocity is
detected by detecting distortion of at least one of the first arm,
the second arm, and the fixing arm.
32. The inertial force sensor according to claim 28, wherein
acceleration is detected by detecting distortion of at least one of
the first arm, the second arm, and the fixing arm.
33. The inertial force sensor according to claim 28, wherein the
detecting device further includes a weight portion formed at an end
of the second arm.
34. The inertial force sensor according to claim 28, wherein an end
of the second arm is folded in meander shape.
Description
TECHNICAL FIELD
[0001] The present invention relates to an inertial force sensor
which detects an inertial force used for various electronic
devices, such as a posture controller or a navigation device, of a
moving body, such as an airplane, an automobile, a robot, a ship,
or a vehicle.
BACKGROUND ART
[0002] A conventional inertial force sensor will be described
below.
[0003] An inertial force sensor which detects an inertial force,
such as an angular velocity or acceleration, has been used. In the
use of the conventional inertial force sensor, an exclusive angular
velocity sensor is used to detect an angular velocity and an
exclusive acceleration sensor is used to detect acceleration. When
angular velocities and accelerations corresponding to a plurality
of detection axes of an X-axis, a Y-axis, and a Z-axis orthogonal
to each other are detected, a plurality of angular velocity sensors
and a plurality of acceleration sensors according to the number of
the detecting axes are used.
[0004] When various types of electronic devices combine and detect
an angular velocity and acceleration or detect angular velocities
and accelerations relative to a plurality of detection axes, a
plurality of angular velocity sensors and a plurality of
acceleration sensors are mounted on a mounting substrate of the
electronic devices.
[0005] The angular velocity sensor oscillates a detecting device in
tuning fork shape, H shape, or T shape and then electrically
detects distortion of the detecting device with occurrence of a
Force de Coriolis to detect an angular velocity. The acceleration
sensor has a weight portion and compares and detects movement of
the weight portion with acceleration with that before operation to
detect acceleration.
[0006] Such conventional inertial force sensors, such as the
angular velocity sensor and the acceleration sensor, are used for a
posture controller or a navigation device of a moving body, such as
a vehicle, according to an inertial force or a detection axis to be
detected.
[0007] The conventional inertial force sensor is disclosed in
Unexamined Japanese Patent Publication No. 2001-208546 (Patent
Document 1) or Unexamined Japanese Patent Publication No.
2001-74767 (Patent Document 2).
[0008] [Patent Document 1] Unexamined Japanese Patent Publication
No. 2001-208546
[0009] [Patent Document 2] Unexamined Japanese Patent Publication
No. 2001-74767
DISCLOSURE OF THE INVENTION
[0010] The present invention provides a small inertial force sensor
which does not require a large mounting area for mounting a
plurality of inertial force sensors and can detect a plurality of
different inertial forces, such as an angular velocity and
acceleration, or inertial forces of a plurality of detection
axes.
[0011] An inertial force sensor of the present invention includes a
detecting device which detects an inertial force, the detecting
device having a first orthogonal arm and a supporting portion, the
first orthogonal arm having a first arm and a second arm fixed in a
substantially orthogonal direction, and the supporting portion
supporting the first arm. The second arm has a folding portion.
With this configuration, there is provided a small inertial force
sensor which realizes detection of a plurality of different
inertial forces and detection of inertial forces of a plurality of
detection axes.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] FIG. 1A is a plan view illustrating a detecting device used
for an inertial force sensor according to exemplary embodiment 1 of
the present invention.
[0013] FIG. 1B is an operation state diagram illustrating an
operation state of the detecting device illustrated in FIG. 1A.
[0014] FIG. 2A is a plan view illustrating a detecting device
according to another embodiment of exemplary embodiment 1 of the
present invention.
[0015] FIG. 2B is a plan view illustrating a detecting device
according to a further embodiment of exemplary embodiment 1 of the
present invention.
[0016] FIG. 3 is an operation state diagram illustrating an
operation state of an inertial force sensor according to exemplary
embodiment 2 of the present invention.
[0017] FIG. 4A is a plan view illustrating a detecting device used
for an inertial force sensor according to exemplary embodiment 3 of
the present invention.
[0018] FIG. 4B is an operation state diagram illustrating an
operation state of the detecting device illustrated in FIG. 4A.
[0019] FIG. 5A is a plan view illustrating a detecting device
according to another embodiment of exemplary embodiment 3 of the
present invention.
[0020] FIG. 5B is a plan view illustrating a detecting device
according to a further embodiment of exemplary embodiment 3 of the
present invention.
[0021] FIG. 6A is a plan view illustrating a detecting device used
for an inertial force sensor according to exemplary embodiment 4 of
the present invention.
[0022] FIG. 6B is an operation state diagram illustrating an
operation state of the detecting device illustrated in FIG. 6A.
[0023] FIG. 7A is a plan view illustrating a detecting device
according to another embodiment of exemplary embodiment 4 of the
present invention.
[0024] FIG. 7B is a plan view illustrating a detecting device
according to a further embodiment of exemplary embodiment 4 of the
present invention.
[0025] FIG. 8A is a plan view illustrating a detecting device used
for an inertial force sensor according to exemplary embodiment 5 of
the present invention.
[0026] FIG. 8B is an operation state diagram illustrating an
operation state of the detecting device illustrated in FIG. 8A.
[0027] FIG. 9 is a plan view illustrating a detecting device
according to another embodiment of exemplary embodiment 5 of the
present invention.
[0028] FIG. 10 is a perspective view of a detecting device
according to a further embodiment of exemplary embodiment 5 of the
present invention.
[0029] FIG. 11 is a plan view of a detecting device used for an
inertial force sensor according to exemplary embodiment 6 of the
present invention.
[0030] FIG. 12 is an operation state diagram illustrating an
operation state of the detecting device illustrated in FIG. 11.
[0031] FIG. 13 is a plan view of a detecting device according to
another embodiment of exemplary embodiment 6 of the present
invention.
[0032] FIG. 14A is a plan view of a detecting device according to a
further embodiment of exemplary embodiment 6 of the present
invention.
[0033] FIG. 14B is a plan view of a detecting device according to a
still another embodiment of exemplary embodiment 6 of the present
invention.
REFERENCE MARKS IN THE DRAWINGS
[0034] 1 Detecting device [0035] 2 First arm [0036] 4 Second arm
[0037] 4a Folding portion [0038] 4b End [0039] 6 First orthogonal
arm [0040] 7 Second orthogonal arm [0041] 8 Supporting portion
[0042] 9 Base portion [0043] 10 Fixing arm [0044] 10b End [0045] 12
Third arm [0046] 14 Fourth arm [0047] 18 Weight portion [0048] 20
Inertial force sensor
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Exemplary Embodyment 1
[0049] FIG. 1A is a plan view of a detecting device used for an
inertial force sensor according to exemplary embodiment 1 of the
present invention. FIG. 1B is an operation state diagram of the
detecting device illustrated in FIG. 1A.
[0050] In FIG. 1A, inertial force sensor 20 has detecting device 1
which detects an inertial force and a processing circuit (not
illustrated). Detecting device 1 has two first orthogonal arms 6
and supporting portion 8. Each of first orthogonal arms 6 has first
arm 2 and second arm 4. First arm 2 is formed so as to be fixed to
second arm 4 in a substantially orthogonal direction. Supporting
portion 8 supports two first arms 2. Supporting portion 8 serves as
base portion 9. When detecting device 1 is mounted on a mounting
substrate (not illustrated), detecting device 1 is fixed to the
mounting substrate using base portion 9. Second arm 4 is folded at
folding portions 4a so that ends 4b of second arm 4 are arranged to
be confronted with first arm 2. Weight portion 18 is formed at end
4b of second arm 4.
[0051] In detecting device 1, first arm 2 and supporting portion 8
are arranged on a substantially identical straight line. Relative
to an X-axis, a Y-axis, and a Z-axis orthogonal to each other, a
longitudinal direction of first arm 2 is arranged in the Y-axis
direction and a longitudinal direction of second arm 4 is arranged
in the X-axis direction.
[0052] Detecting device 1 is integrally molded to a silicon
substrate as a material. A driving electrode is arranged on an arm,
which is driven and oscillated, on the silicon substrate. A
detecting electrode is arranged on an arm, whose distortion is
detected, on the silicon substrate. In detecting device 1
illustrated in FIG. 1A, end 4b of second arm 4 is the arm which is
driven and oscillated, and first arm 2 and second arm 4 are the arm
whose distortion is detected. The driving electrode (not
illustrated) is arranged on end 4b. The detecting electrodes (not
illustrated) are arranged on both of first arm 2 and second arm
4.
[0053] The driving electrode and the detecting electrode are formed
by laminating a lower electrode, a piezoelectric element, and an
upper electrode on the silicon substrate. The lower electrode is
formed by high-frequency sputtering of Pt, for example. A PZT
piezoelectric element is formed on the lower electrode by
high-frequency sputtering, for example. The upper electrode is
formed on the piezoelectric element by Au deposition, for
example.
[0054] When an alternating voltage having a resonance frequency
which resonates the silicon configuring detecting device 1 is
applied between the lower electrode and the upper electrode, the
arm on which the driving electrode is arranged is driven and
oscillated. The arm is distorted due to an angular velocity and
acceleration. A voltage according to the distortion is outputted
from the detecting electrode arranged on the distorted arm. The
processing circuit detects the angular velocity and the
acceleration based on an output voltage outputted from the
detecting electrode.
[0055] With the above configuration, as for an angular velocity, as
illustrated in FIG. 1B, end 4b of second arm 4 is driven and
oscillated in the X-axis direction, for example. A distortion due
to an angular velocity about the Z-axis is caused in the Y-axis
direction of second arm 4. That is to say, a Force de Coriolis
corresponding to the driving and oscillation is caused in the
Y-axis direction of second arm 4. At the same time, a distortion
due to an angular velocity about the Y-axis is caused in the Z-axis
direction of second arm 4. Similarly, a Force de Coriolis
corresponding to the driving and oscillation is caused in the
Z-axis direction of second arm 4. The distortion caused in at least
one of the Y-axis direction and the Z-axis direction of second arm
4 is detected to detect an angular velocity produced in detecting
device 1. The driving and oscillation in the X-axis direction of
end 4b are driving and oscillation in which a solid arrow line and
a dotted arrow line illustrated in FIG. 1B are repeated
alternately, for example.
[0056] As for acceleration, as illustrated in FIG. 1B, a distortion
due to acceleration in the X-axis direction is caused in first arm
2, similarly. That is to say, a force due to a deadweight of second
arm 4 is added to first arm 2. At the same time, a distortion due
to acceleration in the Y-axis direction is caused in second arm 4.
That is to say, a force due to the deadweight of second arm 4 is
added to second arm 4. The distortion caused in at least one of
first arm 2 and second arm 4 is detected to detect acceleration
produced in detecting device 1.
[0057] Thus, a plurality of different inertial forces added to
detecting device 1 is detected. Inertial forces of a plurality of
different detection axes added to detecting device 1 are detected.
Detecting device 1 which reduces a mounting area and is
miniaturized is realized.
[0058] In detecting device 1 of the present invention, end 4b of
second arm 4 is driven and oscillated, and second arm 4 has a shape
folded at folding portion 4a. Thus, detecting device 1 which has a
small mounting area and is miniaturized is realized. In addition, a
distance between driven and oscillated end 4b of second arm 4 and
base portion 9 to which detecting device 1 is fixed becomes
substantially longer. Detection sensitivity of the angular velocity
and the acceleration in each of the directions is increased. Using
miniaturized detecting device 1, a plurality of different angular
velocities and accelerations are detected at high sensitivity.
[0059] In addition, weight portion 18 is formed at end 4b of second
arm 4. Detection sensitivity of the acceleration is improved by an
effect of a mass of weight portion 18. At the same time, an
amplitude of the driving and oscillation of end 4b becomes larger
to improve detection sensitivity of the angular velocity. In these
effects, a product constant (mass.times.moving speed) becomes
larger by weight portion 18 so that a Force de Coriolis caused by
driving and oscillation is increased.
[0060] Detecting device 1 illustrated in FIG. 1A is formed with
weight portion 18. However, weight portion 18 is not always
necessary. The effect of the mass of weight portion 18 is exerted
by provision of weight portion 18 to improve detection sensitivity
of the acceleration and the angular velocity. As illustrated in
FIG. 2A, detecting device 1 which does not have weight portion 18
can exert an operation and effect of the present invention. That is
to say, in detecting device 1, first arm 2 and second arm 4 are
fixed in a substantially orthogonal direction so as to form first
orthogonal arm 6. Second arm 4 is folded at folding portions 4a so
that ends 4b are arranged to face together and first arm 2 is
placed between ends 4b. With this configuration, a plurality of
different angular velocities and accelerations are detected by
detecting device 1 having simple configuration.
[0061] Moreover, second arm 4 is folded at a plurality of folding
portions 4a so that end 4b may be confronted with second arm 4.
Furthermore, as illustrated in FIG. 2B, second arm 4 is folded at a
plurality of folding portions 4a in meander shape so that end 4b
may be confront with second arm 4. Detecting device 1 is thus
configured so that the distance between driven and oscillated end
4b of second arm 4 and base portion 9 to which detecting device 1
is fixed becomes substantially longer. The above operation and
effect can be improved. Accordingly, detecting device 1 which has a
small mounting area, is miniaturized, and has high detection
sensitivity is realized.
[0062] A position of the driving and oscillation added to detecting
device 1 is not always limited to end 4b of second arm 4. Other
positions of second arm 4 or other arms may be driven and
oscillated.
Exemplary Embodyment 2
[0063] An inertial force sensor according to exemplary embodiment 2
of the present invention may be of configuration as illustrated in
FIG. 3. In the inertial force sensor according to exemplary
embodiment 2, the same configuration as that of the inertial force
sensor according to exemplary embodiment 1 is indicated by the same
reference numerals and the detailed description is omitted.
[0064] As illustrated in FIG. 3, in detecting device 1, supporting
portion 8 which supports two first arms 2 is fixed to two fixing
arms 10. Base portion 9 is formed at end 10b of each of fixing arms
10. Base portion 9 is fixed to a mounting substrate (not
illustrated) on which detecting device 1 is mounted. Ends 4b of
second arm 4 are folded at folding portions 4a so as to be away
from fixing arm 10. Although not illustrated, weight portion 18 may
be formed at end 4b of second arm 4.
[0065] In inertial force sensor 20 according to exemplary
embodiment 2, as in inertial force sensor 20 according to exemplary
embodiment 1, detecting device 1 is integrally molded to a silicon
substrate as a material. End 4b of second arm 4 is the arm which is
driven and oscillated. First arm 2, second arm 4, and fixing arm 10
are the arm whose distortion is detected. Accordingly, a driving
electrode (not illustrated) is arranged on end 4b. Detecting
electrodes (not illustrated) are arranged on first arm 2, second
arm 4, and fixing arm 10.
[0066] Moreover, as in exemplary embodiment 1, as illustrated in
FIG. 3, driving and oscillation in which a solid arrow line and a
dotted arrow line are repeated alternately are added in an X-axis
direction of end 4b, for example. A distortion due to a Force de
Coriolis corresponding to the driving and oscillation of end 4b is
detected to detect an angular velocity.
[0067] In detecting device 1 illustrated in FIG. 3, the distortion
due to acceleration in a Y-axis direction is caused in fixing arm
10. The distortion caused in fixing arm 10 is detected using the
detecting electrode to detect acceleration in the Y-axis direction.
Accordingly, as in exemplary embodiment 1, detecting device 1 which
reduces a mounting area and is miniaturized is realized.
[0068] A position of the driving and oscillation added to detecting
device 1 is not always limited to end 4b of second arm 4. Other
positions of second arm 4 or other arms may be driven and
oscillated.
Exemplary Embodyment 3
[0069] FIG. 4A is a plan view of a detecting device used for an
inertial force sensor according to exemplary embodiment 3 of the
present invention. FIG. 4B is an operation state diagram of the
detecting device illustrated in FIG. 4A. In the inertial force
sensor according to exemplary embodiment 3, the same configuration
as that of the inertial force sensor according to exemplary
embodiment 1 or 2 is indicated by the same reference numerals and
the detailed description is omitted.
[0070] In FIG. 4A, inertial force sensor 20 has detecting device 1
which detects an inertial force and a processing circuit (not
illustrated). Detecting device 1 has two first orthogonal arms 6,
supporting portion 8, and two fixing arms 10. Each of first
orthogonal arms 6 has first arm 2 and second arm 4. First arm 2 is
formed so as to be fixed to second arm 4 in a substantially
orthogonal direction. Supporting portion 8 supports two first arms
2. Each of fixing arms 10 has one end fixed to supporting portion 8
and end 10b as the other end formed with base portion 9. Base
portion 9 is fixed to a mounting substrate (not illustrated) on
which detecting device 1 is mounted. In addition, fixing arm 10 has
third arm 12 and fourth arm 14. Third arm 12 is formed so as to be
fixed to fourth arm 14 in a substantially orthogonal direction.
That is to say, fixing arm 10 configures second orthogonal arm 7
having third arm 12 and fourth arm 14. End 10b of fixing arm 10
formed with base portion 9 is an end of fourth arm 14 or an end of
second orthogonal arm 7. Second arm 4 is folded at folding portions
4a so that ends 4b of second arm 4 are confronted with first arm 2.
First arm 2 and end 4b of second arm 4 are arranged to face
together and fixing arm 10 is placed between arm 2 and ends 4b, in
appearance. Moreover, second arm 4 is folded at folding portions 4a
so that ends 4b of second arm 4 are confronted with ends 4b of
another second arm 4.
[0071] In detecting device 1, first arm 2 and supporting portion 8
are arranged on a substantially identical straight line. Third arm
12 and supporting portion 8 are arranged on a substantially
identical straight line. First arm 2 and third arm 12 are arranged
in a substantially orthogonal direction. Relative to an X-axis, a
Y-axis, and a Z-axis orthogonal to each other, a longitudinal
direction of first arm 2 and a longitudinal direction of fourth arm
14 are arranged in the Y-axis direction, and a longitudinal
direction of second arm 4 and a longitudinal direction of third arm
12 are arranged in the X-axis direction.
[0072] As in exemplary embodiment 1, detecting device 1 is
integrally molded to a silicon substrate as a material. In
detecting device 1 illustrated in FIG. 4A, end 4b of second arm 4
is the arm which is driven and oscillated, and first arm 2, second
arm 4, third arm 12, and fourth arm 14 are the arm whose distortion
is detected. Accordingly, a driving electrode (not illustrated) is
arranged on end 4b, and detecting electrodes (not illustrated) are
arranged on first arm 2, second arm 4, third arm 12, and fourth arm
14. The detecting electrodes need not be always provided on all
arms of first arm 2, second arm 4, third arm 12, and fourth arm 14.
The detecting electrode should be provided on the arm whose
distortion is detected.
[0073] With the above configuration, as for an angular velocity, as
illustrated in FIG. 4B, when end 4b of second arm 4 is driven and
oscillated in the X-axis direction, a distortion due to an angular
velocity about the Z-axis is caused in the Y-axis direction of
second arm 4, for example. That is to say, a Force de Coriolis
corresponding to the driving and oscillation is caused in the
Y-axis direction of second arm 4. At the same time, a distortion
due to an angular velocity about the Y-axis is caused in the Z-axis
direction of second arm 4. That is to say, a Force de Coriolis
corresponding to the driving and oscillation is caused in the
Z-axis direction of second arm 4. Accordingly, the distortion
caused in the Y-axis direction and the Z-axis direction of second
arm 4 is detected to detect an angular velocity produced in
detecting device 1. The driving and oscillation in the X-axis
direction of end 4b is driving and oscillation in which a solid
arrow line and a dotted arrow line illustrated in FIG. 4B are
repeated alternately, for example.
[0074] As for acceleration, as illustrated in FIG. 4B, a distortion
due to acceleration in the X-axis direction is caused in fourth arm
14, similarly for example. That is to say, forces due to
deadweights of first arm 2, second arm 4, and third arm 12 are
added to fourth arm 14. At the same time, distortion due to
acceleration in the Y-axis direction is caused in third arm 12.
That is to say, forces due to deadweights of first arm 2 and second
arm 4 are added to third arm 12. Accordingly, the distortion caused
in at least one of third arm 12 and fourth arm 14 is detected to
detect acceleration produced in detecting device 1.
[0075] Thus, a plurality of different inertial forces added to
detecting device 1 is detected. Inertial forces of a plurality of
different detection axes added to detecting device 1 are detected.
Detecting device 1 which reduces a mounting area and is
miniaturized is realized.
[0076] In detecting device 1 of the present invention, end 4b of
second arm 4 is driven and oscillated, and second arm 4 has a shape
folded at folding portion 4a. Thus, detecting device 1 which has a
small mounting area and is miniaturized is realized. In addition, a
distance between driven and oscillated end 4b of second arm 4 and
base portion 9 to which detecting device 1 is fixed becomes
substantially longer. Detection sensitivity of the angular velocity
and the acceleration in each of the directions is increased. Using
miniaturized detecting device 1, the angular velocity and the
acceleration in each of the directions are detected at high
sensitivity. Moreover, detecting device 1 of the present invention
has a plurality of different first orthogonal arms 6 and second
orthogonal arms 7. Detecting device 1 which has a small mounting
area and is excellent in detection sensitivity is realized.
[0077] In addition, weight portion 18 is formed at end 4b of second
arm 4. Detection sensitivity of the acceleration is improved by an
effect of a mass of weight portion 18. At the same time, an
amplitude of the driving and oscillation of end 4b becomes larger
to improve detection sensitivity of the angular velocity. An effect
of forming weight portion 18 is similar to that of exemplary
embodiment 1.
[0078] Detecting device 1 illustrated in FIG. 4A is formed with
weight portion 18. Weight portion 18 is not always necessary. As
illustrated in FIG. 5A, detecting device 1 which does not have
weight portion 18 can exert an operation and effect of the present
invention. That is to say, a plurality of different angular
velocities and accelerations are detected at high sensitivity.
[0079] Moreover, second arm 4 is folded at a plurality of folding
portions 4a so that end 4b may be confronted with second arm 4.
Furthermore, as illustrated in FIG. 5B, second arm 4 is folded at a
plurality of folding portions 4a in meander shape so that end 4b
may be confronted with second arm 4. Detecting device 1 is thus
configured to improve the above operation and effect. Accordingly,
detecting device 1 which has a small mounting area, is
miniaturized, and has high detection sensitivity is realized.
[0080] A position of the driving and oscillation added to detecting
device 1 is not always limited to end 4b of second arm 4. Other
positions of second arm 4 or other arms may be driven and
oscillated.
Exemplary Embodyment 4
[0081] FIG. 6A is a plan view of a detecting device used for an
inertial force sensor according to exemplary embodiment 4 of the
present invention. FIG. 6B is an operation state diagram of the
detecting device illustrated in FIG. 6A. In the inertial force
sensor according to exemplary embodiment 4, the same configuration
as that of the inertial force sensors according to exemplary
embodiments 1 to 3 is indicated by the same reference numerals and
the detailed description is omitted.
[0082] In FIG. 6A, inertial force sensor 20 has detecting device 1
which detects an inertial force and a processing circuit (not
illustrated). Detecting device 1 has two first orthogonal arms 6,
supporting portion 8, and two fixing arms 10. Each of first
orthogonal arms 6 has first arm 2 and second arm 4. First arm 2 is
formed so as to be fixed to second arm 4 in a substantially
orthogonal direction. Supporting portion 8 supports two first arms
2. Each of fixing arms 10 has one end fixed to supporting portion 8
and end 10b as the other end formed with base portion 9. Base
portion 9 is fixed to a mounting substrate (not illustrated) on
which detecting device 1 is mounted. In addition, second arm 4 is
folded at folding portions 4a so that ends 4b of second arm 4 are
confronted with second arm 4. Weight portion 18 is formed at end 4b
of second arm 4.
[0083] In detecting device 1, first arm 2 and supporting portion 8
are arranged on a substantially identical straight line. Fixing arm
10 and supporting portion 8 are arranged on a substantially
identical straight line. First arm 2 and fixing arm 10 are arranged
in a substantially orthogonal direction. Relative to an X-axis, a
Y-axis, and a Z-axis orthogonal to each other, a longitudinal
direction of first arm 2 is arranged in the Y-axis direction and a
longitudinal direction of second arm 4 is arranged in the X-axis
direction.
[0084] As in exemplary embodiment 1, detecting device 1 is
integrally molded to a silicon substrate as a material. In
detecting device 1 illustrated in FIG. 6A, end 4b of second arm 4
is the arm which is driven and oscillated, and first arm 2, second
arm 4, and fixing arm 10 are the arm whose distortion is detected.
A driving electrode (not illustrated) is arranged at end 4b.
Detecting electrodes (not illustrated) are arranged on first arm 2,
second arm 4, and fixing arm 10. The detecting electrodes need not
be always provided on all arms of first arm 2, second arm 4, and
fixing arm 10. The detecting electrode should be provided on the
arm whose distortion is detected.
[0085] With the above configuration, as for an angular velocity, as
illustrated in FIG. 6B, when end 4b of second arm 4 is driven and
oscillated in the Y-axis direction, a distortion due to an angular
velocity about the Z-axis is caused in the X-axis direction of
first arm 2, for example. That is to say, a Force de Coriolis
corresponding to the driving and oscillation is caused in the
X-axis direction of second arm 4. At the same time, a distortion
due to an angular velocity about the X-axis is caused in the Z-axis
direction of second arm 4. That is to say, a Force de Coriolis
corresponding to the driving and oscillation is caused in the
Z-axis direction of second arm 4. Accordingly, the distortion
caused in the X-axis direction of first arm 2 and the Z-axis
direction of second arm 4 is detected to detect an angular velocity
produced in detecting device 1. The driving and oscillation in the
Y-axis direction of end 4b are driving and oscillation in which a
solid arrow line and a dotted arrow line illustrated in FIG. 6B are
repeated alternately, for example.
[0086] As for acceleration, as illustrated in FIG. 6B, a distortion
due to acceleration in the X-axis direction is caused in first arm
2, for example. That is to say, a force due to a deadweight of
second arm 4 is added to first arm 2. At the same time, a
distortion due to acceleration in the Y-axis direction is caused in
fixing arm 10. That is to say, forces due to deadweights of first
arm 2 and second arm 4 are added to fixing arm 10. Accordingly, the
distortion caused in at least one of first arm 2 and fixing arm 10
is detected to detect acceleration produced in detecting device
1.
[0087] Thus, a plurality of different inertial forces added to
detecting device 1 is detected. Inertial forces of a plurality of
different detection axes added to detecting device 1 are detected.
Detecting device 1 which reduces a mounting area and is
miniaturized is realized.
[0088] In detecting device 1, second arms 4 are folded at folding
portions 4a so that second arms 4 are arranged so as to be
confronted with each other. Thus, detecting device 1 which has a
small mounting area and is miniaturized is realized. In addition,
end 4b of second arm 4 is driven and oscillated to detect the
distortion of each of the arms. That is to say, detecting device 1
is thus configured so that a distance between driven and oscillated
end 4b of second arm 4 and base portion 9 to which detecting device
1 is fixed becomes substantially longer. An amplitude of the
driving and oscillation of end 4b becomes larger to improve
detection sensitivity of the angular velocity. Using miniaturized
detecting device 1, a plurality of different angular velocities and
accelerations are detected at high sensitivity.
[0089] In addition, weight portion 18b is formed at end 4b of
second arm 4. Detection sensitivity of the acceleration is improved
by an effect of a mass of weight portion 18. At the same time, an
amplitude of the driving and oscillation of end 4b becomes larger
to improve detection sensitivity of the angular velocity. An effect
of forming weight portion 18 is similar to that of exemplary
embodiment 1.
[0090] Detecting device 1 illustrated in FIG. 6A is formed with
weight portion 18. Weight portion 18 is not always necessary. As
illustrated in FIG. 7A, detecting device 1 which does not have
weight portion 18 can exert an operation and effect of the present
invention. That is to say, a plurality of different angular
velocities and accelerations are detected at high sensitivity.
[0091] Moreover, second arm 4 is folded at a plurality of folding
portions 4a so that end 4b may be confronted with second arm 4.
Furthermore, as illustrated in FIG. 7B, second arm 4 is folded at a
plurality of folding portions 4a in meander shape so that end 4b
may be confronted with second arm 4. Detecting device 1 is thus
configured to improve detection sensitivity of the angular
velocity. Detecting device 1 which has a small mounting area, is
miniaturized, and has high detection sensitivity is realized.
[0092] A position of the driving and oscillation added to detecting
device 1 is not always limited to end 4b of second arm 4. Other
positions of second arm 4 or other arms may be driven and
oscillated.
Exemplary Embodyment 5
[0093] FIG. 8A is a plan view of a detecting device used for an
inertial force sensor according to exemplary embodiment 5 of the
present invention. FIG. 8B is an operation state diagram of the
detecting device illustrated in FIG. 8A. In the inertial force
sensor according to exemplary embodiment 5, the same configuration
as that of the inertial force sensors according to exemplary
embodiments 1 to 4 is indicated by the same reference numerals and
the detailed description is omitted.
[0094] In FIG. 8A, inertial force sensor 20 has detecting device 1
which detects an inertial force and a processing circuit (not
illustrated). Detecting device 1 has two first orthogonal arms 6,
supporting portion 8, and two fixing arms 10. Each of first
orthogonal arms 6 has first arm 2 and second arm 4. First arm 2 is
formed so as to be fixed to second arm 4 in a substantially
orthogonal direction. Supporting portion 8 supports two first arms
2. Each of fixing arms 10 has one end fixed to supporting portion 8
and end 10b as the other end formed with base portion 9. Base
portion 9 is fixed to a mounting substrate (not illustrated) on
which detecting device 1 is mounted. In addition, fixing arm 10 has
third arm 12 and fourth arm 14. Third arm 12 is formed so as to be
fixed to fourth arm 14 in a substantially orthogonal direction.
That is to say, fixing arm 10 configures second orthogonal arm 7
having third arm 12 and fourth arm 14. End 10b of fixing arm 10
formed with base portion 9 is an end of fourth arm 14 and also an
end of second orthogonal arm 7. At least a part of third arm 12
serves as first arm 2. Second arm 4 is folded at folding portions
4a so that ends 4b of second arm 4 are confronted with second arm 4
mutually. Second arm 4 is folded at folding portions 4a so that
ends 4b of second arm 4 are confronted with fourth arm 14.
[0095] In detecting device 1, third arm 12 and supporting portion 8
are arranged on a substantially identical straight line. In other
words, first arm 2 and supporting portion 8 are arranged on a
substantially identical straight line. Relative to an X-axis, a
Y-axis, and a Z-axis orthogonal to each other, a longitudinal
direction of first arm 2 and a longitudinal direction of third arm
12 are arranged in the Y-axis direction, and a longitudinal
direction of second arm 4 and a longitudinal direction of fourth
arm 14 are arranged in the X-axis direction.
[0096] As in exemplary embodiment 1, detecting device 1 is
integrally molded to a silicon substrate as a material. In
detecting device 1 illustrated in FIG. 8A, end 4b of second arm 4
is the arm which is driven and oscillated, and first arm 2, second
arm 4, and fixing arm 10 are the arm whose distortion is detected.
A driving electrode (not illustrated) is arranged on end 4b.
Detecting electrodes (not illustrated) are arranged on first arm 2,
second arm 4, third arm 12, and fourth arm 14. The detecting
electrodes need not be always provided on all arms of first arm 2,
second arm 4, third arm 12, and fourth arm 14. The detecting
electrode should be provided on the arm whose distortion is
detected.
[0097] With the above configuration, as for an angular velocity, as
illustrated in FIG. 8B, when end 4b of second arm 4 is driven and
oscillated in the Y-axis direction, a distortion due to an angular
velocity about the Z-axis is caused in the X-axis direction of
third arm 12, for example. That is to say, a Force de Coriolis
corresponding to the driving and oscillation is caused in the
X-axis direction of second arm 4. At the same time, a distortion
due to an angular velocity about the X-axis is caused in the Z-axis
direction of second arm 4, third arm 12, and fourth arm 14. That is
to say, a Force de Coriolis corresponding to the driving and
oscillation is caused in the Z-axis direction of second arm 4,
third arm 12, and fourth arm 14. Accordingly, the distortion caused
in the Y-axis direction of second arm 4 and the Z-axis direction of
at least one of second arm 4, third arm 12, and fourth arm 14 is
detected to detect an angular velocity produced in detecting device
1. The driving and oscillation in the Y-axis direction of end 4b
are driving and oscillation in which a solid arrow line and a
dotted arrow line illustrated in FIG. 8B are repeated alternately,
for example.
[0098] As for acceleration, as illustrated in FIG. 8B, a distortion
due to acceleration in the X-axis direction is caused in third arm
12, for example. That is to say, a force due to a deadweight of
second arm 4 is added to third arm 12. At the same time, a
distortion due to acceleration in the Y-axis direction is caused in
fourth arm 14. That is to say, forces due to deadweights of second
arm 4 and third arm 12 are added to fourth arm 14. Accordingly, the
distortion caused in at least one of third arm 12 and fourth arm 14
is detected to detect acceleration produced in detecting device
1.
[0099] Thus, a plurality of different inertial forces added to
detecting device 1 is detected. Inertial forces of a plurality of
different detection axes added to detecting device 1 are detected.
Detecting device 1 which reduces a mounting area and is
miniaturized is realized.
[0100] In detecting device 1, second arms 4 are folded at folding
portions 4a so that second arms 4 are arranged so as to be
confronted with each other. Thus, detecting device 1 which has a
small mounting area and is miniaturized is realized. In addition,
end 4b of second arm 4 is driven and oscillated to detect the
distortion of each of the arms. That is to say, detecting device 1
is thus configured so that a distance between driven and oscillated
end 4b of second arm 4 and base portion 9 to which detecting device
1 is fixed becomes substantially longer. An amplitude of the
driving and oscillation of end 4b becomes larger to improve
detection sensitivity of an angular velocity. Using miniaturized
detecting device 1, a plurality of different angular velocities and
accelerations are detected at high sensitivity.
[0101] Moreover, second arm 4 is folded at a plurality of folding
portions 4a so that end 4b may be confronted with second arm 4.
Furthermore, as illustrated in FIG. 9, second arm 4 is folded at a
plurality of folding portions 4a in meander shape so that end 4b
may be confronted with second arm 4. Detecting device 1 is thus
configured to improve detection sensitivity of the angular
velocity. Detecting device 1 which has a small mounting area, is
miniaturized, and has high detection sensitivity is realized.
[0102] In addition, weight portion 18 is formed at end 4b of second
arm 4. Detection sensitivity of acceleration is improved. An
amplitude of the driving and oscillation of end 4b becomes larger
to improve detection sensitivity of the angular velocity.
[0103] Accordingly, as illustrated in FIG. 10, when second arm 4 is
folded at folding portions 4a so that ends 4b are confronted with
second arm 4 and weight portion 18 is formed at end 4b, detection
sensitivity of both the angular velocity and acceleration is
improved.
[0104] A position of the driving and oscillation added to detecting
device 1 is not always limited to end 4b of second arm 4. Other
positions of second arm 4 or other arms may be driven and
oscillated.
Exemplary Embodyment 6
[0105] FIG. 11 is a plan view of a detecting device used for an
inertial force sensor according to exemplary embodiment 6 of the
present invention. FIG. 12 is an operation state diagram of the
detecting device illustrated in FIG. 11. In the inertial force
sensor according to exemplary embodiment 6, the same configuration
as that of the inertial force sensors according to exemplary
embodiments 1 to 5 is indicated by the same reference numerals and
the detailed description is omitted.
[0106] In FIG. 11, inertial force sensor 20 has detecting device 1
which detects an inertial force and a processing circuit (not
illustrated). Detecting device 1 has two first orthogonal arms 6,
supporting portion 8, and two fixing arms 10. Each of first
orthogonal arms 6 has first arm 2 and second arm 4. First arm 2 is
formed so as to be fixed to second arm 4 in a substantially
orthogonal direction. Supporting portion 8 supports two first arms
2. Each of fixing arms 10 has one end fixed to supporting portion 8
and end 10b as the other end formed with base portion 9. Base
portion 9 is fixed to a mounting substrate (not illustrated) on
which detecting device 1 is mounted. At least a part of fixing arm
10 serves as first arm 2.
[0107] In detecting device 1, fixing arm 10 and supporting portion
8 are arranged on a substantially identical straight line. In other
words, first arm 2 and supporting portion 8 are arranged on a
substantially identical straight line. Relative to an X-axis, a
Y-axis, and a Z-axis orthogonal to each other, a longitudinal
direction of first arm 2 and a longitudinal direction of fixing arm
10 are arranged in the Y-axis direction, and a longitudinal
direction of second arm 4 is arranged in the X-axis direction.
[0108] As in exemplary embodiment 1, detecting device 1 is
integrally molded to a silicon substrate as a material. In
detecting device 1 illustrated in FIG. 11, end 4b of second arm 4
is the arm which is driven and oscillated, and second arm 4 and
fixing arm 10 are the arm whose distortion is detected. A driving
electrode (not illustrated) is arranged on end 4b. Detecting
electrodes (not illustrated) are arranged on second arm 4 and
fixing arm 10. The detecting electrodes need not be always provided
on all arms of first arm 2, second arm 4, and fixing arm 10. The
detecting electrode should be provided on the arm whose distortion
is detected.
[0109] With the above configuration, as for an angular velocity, as
illustrated in FIG. 12, when end 4b of second arm 4 is driven and
oscillated in the Y-axis direction, a distortion due to an angular
velocity about the Z-axis is caused in the X-axis direction of
fixing arm 10, for example. That is to say, a Force de Coriolis
corresponding to the driving and oscillation is caused in the
X-axis direction of second arm 4. At the same time, a distortion
caused in an angular velocity about the X-axis is caused in the
Z-axis direction of fixing arm 10 and second arm 4. That is to say,
a Force de Coriolis corresponding to the driving and oscillation is
caused in the Z-axis direction of second arm 4 and fixing arm 10.
Accordingly, the distortion caused in the X-axis direction of
fixing arm 10 and the Z-axis direction of at least one of second
arm 4 and fixing arm 10 is detected to detect an angular velocity
produced in detecting device 1. The driving and oscillation in the
Y-axis direction of end 4b are driving and oscillation in which a
solid arrow line and a dotted arrow line illustrated in FIG. 12 are
repeated alternately, for example.
[0110] As for acceleration, as illustrated in FIG. 12, a distortion
due to acceleration in the X-axis direction is caused in fixing arm
10, for example. That is to say, a force due to a deadweight of
second arm 4 is added to fixing arm 10. At the same time, a
distortion due to acceleration in the Y-axis direction is caused in
second arm 4. A force due to a deadweight of second arm 4 is added
to second arm 4. Accordingly, the distortion caused in at least one
of fixing arm 10 and second arm 4 is detected to detect
acceleration produced in detecting device 1.
[0111] Thus, a plurality of different inertial forces added to
detecting device 1 is detected. Inertial forces of a plurality of
different detection axes added to detecting device 1 are detected.
Detecting device 1 which reduces a mounting area and is
miniaturized is realized.
[0112] In addition, as illustrated in FIG. 13, weight portion 18 is
formed at end 4b of second arm 4. Detection sensitivity of
acceleration is improved. An amplitude of the driving and
oscillation of end 4b becomes larger to improve detection
sensitivity of the angular velocity.
[0113] Moreover, as illustrated in FIG. 14A, second arm 4 is folded
at a plurality of folding portions 4a so that end 4b may be
confronted with second arm 4. Furthermore, as illustrated in FIG.
14B, second arm 4 is folded at a plurality of folding portions 4a
in meander shape so that end 4b may be confronted with second arm
4. Detecting device 1 is thus configured so that an amplitude of
the driving and oscillation of end 4b becomes larger to improve
detection sensitivity of the angular velocity. Detecting device 1
which has a small mounting area, is miniaturized, and has high
detection sensitivity is realized.
[0114] A position of the driving and oscillation added to detecting
device 1 is not always limited to end 4b of second arm 4. Other
positions of second arm 4 or other arms may be driven and
oscillated.
INDUSTRIAL APPLICABILITY
[0115] The inertial force sensor according to the present invention
can detect a plurality of inertial forces and inertial forces of a
plurality of detection axes and is applicable to various electronic
devices.
* * * * *