JP2008058061A - Angular velocity sensor and electronic device - Google Patents

Abstract

An angular velocity sensor that realizes angular velocity detection of a two-axis rotation system of a Z-axis rotation system and a Y-axis rotation system by a piezoelectric vibrating piece for detecting the angular velocity of a one-axis rotation system and a series of detection means.
An angular velocity sensor (1) includes a base (20) and a connecting arm (31, 32) connected to the base (20) or the base (20). The angular velocity sensor (1) extends in parallel with the Y-axis and performs bending vibration in the X-axis direction perpendicular to the Y-axis. The arm 40, 50 and the detection arm 60 parallel to the drive arm 40, 50 are formed on the XY plane, and the detection arm 60 by the Coriolis force in the Z-axis direction provided by rotation around the Y-axis. Detection that outputs a detection signal in accordance with both the vibration component generated in the detection arm 60 and the vibration component generated in the detection arm 60 due to the Coriolis force in the Y-axis direction given by rotation about the Z-axis perpendicular to the XY plane Means. Further, weight portions 63 and 64 having a width 5 to 10 times the width of the detection arm portions 61 and 62 are formed at the tip of the detection arm 60.
[Selection] Figure 1

Description

  The present invention relates to an angular velocity sensor that outputs a detection signal in response to both an angular velocity of a Z-axis rotating system and an angular velocity of a Y-axis rotating system, and an electronic device equipped with the angular velocity sensor.

  Angular velocity sensors (sometimes called gyroscopes) that detect rotational angular velocities are used in navigation systems, aircraft and ship attitude control systems, robot and other attitude control systems, video camera and digital camera shake prevention devices, and the like. ing. These electronic devices are required to be reduced in size, and accordingly, the angular velocity sensor is also required to be reduced in size and simplified in configuration.

  Conventionally, an angular velocity sensor has been proposed in which three vibrating bodies are integrally formed on an elastic body formed of a piezoelectric material, and the vibrating bodies on both sides and the center vibrating body are driven to vibrate in mutually opposite phases. . When this angular velocity sensor is placed in a rotating system around the Z axis, the vibrating bodies on both sides vibrate in the X direction with opposite phases due to the Coriolis force in the Y direction. And the central vibrating body vibrate in the Z direction with opposite phases. Then, by detecting the vibration component in the X direction from the vibrating bodies on both sides, and detecting the vibration component in the Z direction by the central vibrating body, the angular velocity that individually detects the rotation output around the two axes of the Z axis and the Y axis. A sensor is known (for example, see Patent Document 1).

JP-A-8-327362 (page 11, FIGS. 13 to 15)

  In Patent Document 1, each of the three vibrators includes a drive electrode, a detection electrode, and a ground electrode (GND electrode), and further supports detection of the Z-axis rotation system and detection of the Y-axis rotation system. Since the detection means is provided, the formation of electrodes is complicated, and the system configuration is complicated by two series of detection circuits.

  SUMMARY OF THE INVENTION The object of the present invention is to solve the above-described problems, and to detect the angular velocity of a uniaxial rotating system using a piezoelectric vibrating piece and to detect the angular velocities of the Z-axis rotating system and the Y-axis rotating system with a series of detecting means. It is to provide a small angular velocity sensor with a simple structure for realizing detection.

  An angular velocity sensor according to the present invention includes a base, a drive arm that extends in parallel to the Y axis from the base or a connecting arm connected to the base, and performs bending vibration in the X-axis direction perpendicular to the Y axis, and the drive arm A detection arm parallel to the XY plane, a piezoelectric vibrating piece formed on the XY plane, a vibration component generated in the detection arm by Coriolis force given by rotation about the Y axis, and a Z axis perpendicular to the XY plane Detecting means for outputting a detection signal in accordance with both of the vibration component generated in the detection arm by the Coriolis force given by the rotation of.

  According to this invention, the structure of the piezoelectric vibrating piece described above is used for an angular velocity sensor of a uniaxial rotating system, and the vibration component of the Y axis rotating system and the vibrating component of the Z axis rotating system are generated in the detection arm. In addition, since the detection electrode formed on the detection arm and the detection circuit provided outside can be configured in one common series, an angular velocity sensor capable of detecting the angular velocity of a two-axis rotating system with a simple configuration is provided. Can be provided.

  In the present invention, the vibration component generated in the detection arm by the Coriolis force in the Z-axis direction given by the rotation around the Y axis is a torsional vibration component, and the Y-axis direction given by the rotation around the Z axis It is preferable that the vibration component generated in the detection arm by the Coriolis force is a bending vibration component.

  In this way, different vibration modes of the Y-axis rotation system and the Z-axis rotation system are generated and detected as angular velocities, so that the drive arm (including the drive electrode) and the detection arm that are common to the one-axis rotation system are detected. An angular velocity sensor can be configured with (including detection electrodes).

  The piezoelectric vibrating piece includes a detection arm extending in the Y-axis direction and a negative Y-axis direction from the base, a first connecting arm extending in the X-axis direction from the base, and a negative from the base. A second connecting arm extending in the X-axis direction, a driving arm connected to the first connecting arm, extending in the Y-axis direction and the minus Y-axis direction, and connected to the second connecting arm. And a drive arm that extends in the Y-axis direction and the minus Y-axis direction.

  The angle sensor configured as described above has a form called a WT type angular velocity sensor (double T type). WT type angular velocity sensors are known to have high detection sensitivity, and high detection sensitivity is realized even in detection of angular velocity of a biaxial rotating system.

  Further, the piezoelectric vibrating piece has a shape in which a weight portion is formed at each end of the drive arm and the detection arm, and a width D of the weight portion of the detection arm is larger than a width d of the detection arm portion of the detection arm. Thus, it is preferably set in the range of 5d ≦ D ≦ 10d.

  The piezoelectric vibrating piece can be miniaturized by forming the weight portion at the tip of the drive arm and the detection arm. Furthermore, in the present invention, since the vibration component of the Y-axis rotation system is a torsional vibration component, it is easy to generate torsional vibrations by increasing the width of the weight part much larger than the width of the vibration part, and the detection power is increased. be able to.

Moreover, it is preferable to adjust the sensitivity ratio between the detection sensitivity of the bending vibration component of the Z-axis rotation system and the detection sensitivity of the torsional vibration component of the Y-axis rotation system by the detuning frequency.
Here, the detuning frequency represents the difference between the frequency of the detection signal and the frequency of the drive signal.

  Although details will be described in an embodiment described later, the sensitivity ratio between the Y-axis rotation system and the Z-axis rotation system can be changed by adjusting the detuning frequency. Accordingly, the detection sensitivity of the two axes can be set depending on whether the detection of the Y-axis rotation system or the Z-axis rotation system is regarded as important depending on the purpose and application of use of the angular velocity sensor.

  In the present invention, it is desirable that the sensitivity ratio between the detection sensitivity of the bending vibration component of the Z-axis rotation system and the detection sensitivity of the torsional vibration component of the Y-axis rotation system is approximately 1: 1.

  In this way, since the detection sensitivities of the Z-axis rotation system and the Y-axis rotation system are the same, it is possible to detect a balanced angular velocity in both the Z-axis rotation system and the Y-axis rotation system.

  In addition, an electronic apparatus according to the present invention includes a base, a drive arm that extends in parallel to the Y axis from the base or a connecting arm connected to the base, and performs bending vibration in the X-axis direction perpendicular to the Y-axis, A detection arm parallel to the drive arm, a piezoelectric vibrating piece formed on the XY plane, a vibration component generated in the detection arm by Coriolis force provided by rotation around the Y axis, and a Z perpendicular to the XY plane Detection means for outputting a detection signal according to both of the vibration component generated in the detection arm by the Coriolis force given by the rotation around the axis, and a lens including the X-axis direction as an optical axis are provided. An electronic device characterized by that.

  Here, examples of the electronic device include a digital camera using an angular velocity sensor for correcting camera shake, an HDD (Hard Disk Drive) using an impact detection sensor, and the like.

  For camera shake correction of a digital camera, image blur can be suppressed by adjusting the shutter speed by detecting the angular velocity of a biaxial rotating system that affects the focal depth of the digital camera.

  In addition, in the HDD, when an impact is applied to the mounted electronic device or the like in two directions other than the horizontal direction of the HDD, the impact can be sensed to prevent the pickup device from being retracted and destroyed. .

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
1 to 7 show the structure of the angular velocity sensor of the present invention and the two-axis detection form.
Note that the embodiments described below are preferred specific examples of the present invention, and thus various technically preferable limitations are given. However, the scope of the present invention is particularly limited in the following description. Unless otherwise stated, the present invention is not limited to these forms. The drawings referred to in the following description are schematic views in which the vertical and horizontal scales of members or parts are different from actual ones for convenience of illustration.
(Embodiment)

  FIG. 1 is a perspective view showing an angular velocity sensor according to an embodiment of the present invention. In FIG. 1, an angular velocity sensor 1 according to this embodiment includes a piezoelectric vibrating piece 10, a detection circuit (not shown) as detection means, and an oscillation circuit as excitation means. In addition, although the piezoelectric vibrating piece 10 can be comprised from a well-known piezoelectric material, in this embodiment, a crystal vibrating piece is illustrated and demonstrated.

The piezoelectric vibrating piece 10 is formed in the XY plane. In the present embodiment, the piezoelectric vibrating piece 10 is made of quartz, and is a Z-cut obtained by cutting the X-axis and Y-axis of the X-axis called the electrical axis, the Y-axis called the mechanical axis, and the Z-axis called the optical axis in the plane direction. It is formed from a quartz substrate.
The planar shape of the piezoelectric vibrating piece 10 is developed on the XY plane in accordance with the crystal axis of the crystal, and is 180 ° point-symmetric with respect to the gravity center position G.

  The piezoelectric vibrating piece 10 is formed with a rectangular base 20 having end faces parallel to the X-axis direction and the Y-axis direction, respectively, and extends in the direction parallel to the X-axis from the center of the two end faces of the base 20 parallel to the Y-axis. A pair of extending drive arms 40 and 50 and a detection arm 60 extending in the direction parallel to the Y axis from the center of the two end faces of the base 20 parallel to the X axis are formed. The driving arm 40 includes a first connecting arm 31 extending from the end face of the base portion 20 in the X-axis direction, and two driving arms 40 extending in the Y-axis direction and the minus Y-axis direction orthogonal to the first connecting arm 31. It is comprised by the vibration parts 41 and 42. Similarly, the drive arm 50 includes two vibrating portions 51 and 52 that are orthogonal to the second connecting arm 32 extending in the minus X-axis direction from the base portion 20 and extend in the Y-axis direction and the minus Y-axis direction. ing.

  At the tips of the vibration parts 41, 42, 51, 52, substantially square weight parts 43, 44, 53, 54 that are wider than the other parts are formed.

  The detection arm 60 includes detection arm portions 61 and 62 extending linearly in the Y-axis direction and the negative Y-axis direction from the two end portions of the base portion 20. The substantially square weight parts 63 and 64 having a width wider than the part are formed.

  Here, the widths of the weight parts 63 and 64 formed at the tips of the detection arm parts 61 and 62 are set larger than the other weight parts 43, 44, 53 and 54, and the widths of the weight parts 63 and 64 are set. Is D, and the width of the detection arm portions 61 and 62 is d, 5d ≦ D ≦ 10d. That is, the widths of the weight parts 63 and 64 are designed to be 5 to 10 times the width d of the detection arm parts 61 and 62.

  The reason why the weights 63 and 64 are set in this way is to efficiently obtain torsional vibration of the detection arm 60 in the angular velocity detection of the Y-axis rotation system described later (see FIGS. 4 to 6).

A concave groove 45, 46, 55, 56, 65, 66 is formed in the thickness direction at the center in the width direction of each of the vibration parts 41, 42, 51, 52 and the detection arm parts 61, 62.
The weights 43, 44, 53, 54, 63, 64 and the grooves 45, 46, 55, 56, 65, 66 are provided to reduce the size of the piezoelectric vibrating piece 10. The invention is not particularly limited.

  The drive arms 40 and 50 have the widths and lengths of the vibration parts 41, 42, 51, and 52, the dimensions of the weight parts 43, 44, 53, and the grooves 45 and 46 so that the drive vibration of a predetermined frequency is generated. , 55 and 56 are set. In addition, the width and length of the detection arm portions 61 and 62, the dimensions of the weight portions 63 and 64, and the dimensions of the grooves 65 and 66 are set in the detection arm 60 so that predetermined detection vibration is generated.

  The piezoelectric vibrating piece 10 having the shape as described above is generally called a WT (double T type) piezoelectric vibrating piece as a basic structure, and is said to be advantageous for downsizing and high accuracy. Except for the relationship between the width of 62 and the width of the weight portions 63 and 64, the configuration is the same as that of the WT type already proposed.

  The drive arms 40 and 50 and the detection arm 60 are formed with drive electrodes and detection electrodes (not shown), respectively. The drive electrode and the detection electrode may have a configuration already proposed in the WT type piezoelectric vibrating piece, and are integrated on the back side of the base 20 and connected to a detection circuit and an oscillation circuit (not shown). The detection circuit and the oscillation circuit have the same configuration as that used in the conventional WT type piezoelectric vibrating piece.

Next, the operation of the piezoelectric vibrating piece of the present embodiment described above, and detection of the angular velocity of the Z-axis rotation system and the rotation system around the Y-axis (hereinafter sometimes simply referred to as the Y-axis rotation system) will be described.
FIG. 2 is an explanatory diagram schematically illustrating the operation of the piezoelectric vibrating piece according to the present embodiment, and FIG. 3 is an explanatory diagram schematically illustrating the operation of the Z-axis rotation system. 2 and 3, the drive arms 40 and 50 and the detection arm 60 are simplified and represented by lines in order to easily express the vibration form. The same components as those in FIG. 1 are denoted by the same reference numerals, and the description of the structure is omitted.

  First, the static operation of the piezoelectric vibrating piece 10 will be described. In FIG. 2, the drive vibration is a bending vibration indicated by an arrow A of the vibration parts 41, 42, 51, 52, and a vibration state indicated by a solid line and a vibration state indicated by a two-dot chain line are repeated at a predetermined frequency. . At this time, since the vibration parts 41 and 42 and the vibration parts 51 and 52 are oscillating line-symmetrically with respect to the Y axis passing through the gravity center position G, the base part 20, the connecting arms 31 and 32, and the detection arm part 61. , 62 hardly vibrate.

  Next, the operation when the rotational angular velocity ω around the Z axis is applied will be described. In FIG. 3, in the Z-axis rotation system, the detected vibration repeats a vibration state indicated by a solid line and a vibration state indicated by a two-dot chain line. The detected vibration is applied to the drive arms 40 and 50 when a rotational angular velocity ω around the Z-axis is applied to the piezoelectric vibrating piece 10 in a state where the piezoelectric vibrating piece 10 performs the driving vibration (bending vibration) shown in FIG. It is generated by the Coriolis force in the direction indicated by the arrow B.

  Due to the Coriolis force in the direction of arrow B, the driving arms 40 and 50 vibrate in the circumferential direction with respect to the gravity center position G. At the same time, as shown by an arrow C, the detection arm portions 61 and 62 perform bending vibration in the direction opposite to the arrow B in response to the vibration of the arrow B.

  The drive electrode and the detection electrode formed on the piezoelectric vibrating piece 10 are electrically connected to the detection circuit and the oscillation circuit (both mounted on the semiconductor device) via the connection electrode formed on the base 20. Yes. As a result, the piezoelectric vibrating piece 10 is bent and vibrated by the oscillation circuit, and a detection vibration signal corresponding to the angular velocity is output from the detection arm 60 to the detection circuit. Then, an electrical signal corresponding to the angular velocity is output by the semiconductor device.

Subsequently, a detection operation of a rotation system around the Y axis (hereinafter, sometimes simply referred to as a Y axis rotation system) will be described with reference to the drawings.
4 to 6 show the detection operation of the Y-axis rotation system, FIG. 4 is a perspective view, and FIGS. 5 and 6 are upper side views showing the state viewed from above (in the direction of arrow A) in FIG. When the rotational angular velocity ω is applied around the Y axis when the driving arms 40 and 50 are flexurally vibrating, the piezoelectric vibrating reed 10 is driven by the Coriolis force as shown in FIG. In a vibration mode in which the bending vibration in the direction and the bending vibration in the Z-axis direction are combined.

  That is, due to the Coriolis force, the driving arm 40 bends and vibrates in the Z direction in opposite phases with the connecting arm 31 as the axis of vibration and the driving arm 50 with the connecting arm 32 as the axis of vibration. Then, torsional vibration in the direction of arrow T is generated in the detection arm 60. By detecting this torsional vibration, a detection signal corresponding to the angular velocity is output to the detection circuit. Then, an electrical signal corresponding to the angular velocity is output by the semiconductor device.

  The relationship between Coriolis force and torsional vibration (detected vibration) in the Y-axis rotation system will be described with reference to FIGS. FIG. 5 illustrates a case where the driving arms 40 and 50 vibrate in the outer direction (indicated by an arrow + V in the drawing). The driving arm 40 is moved in the + Z direction by the Coriolis force F, and the driving arm 50 is moved in the −Z direction. It is deformed by vibration. Then, the detection arm 60 undergoes torsional vibration deformation in a direction (+ T direction) to cancel the Coriolis force F.

FIG. 6 illustrates a case where the driving arms 40 and 50 vibrate in the inner direction (indicated by an arrow −V in the figure). The driving arm 40 is moved in the −Z direction by the Coriolis force F, and the driving arm 50 is + Z. Vibration deformation in the direction. Then, the detection arm 60 undergoes torsional vibration deformation in a direction (-T direction) in which the Coriolis force F is canceled.
In this manner, the detection arm 60 can repeat the torsional vibration as shown in FIGS. 5 and 6 by the Coriolis force F, detect the torsion signal as a detection signal, and detect the angular velocity of the Y-axis rotation system.
In the case of the X-axis rotating system, no detection signal is output to the detection arm 60 because no Coriolis force is generated.

  As described above, the bending vibration in the X-axis direction of the detection arm 60 can be detected as a detection signal for the Z-axis rotation system, and the torsional vibration of the detection arm 60 can be detected as a detection signal for the Y-axis rotation system. Can do. In the present embodiment, as described above, the detection electrode for the Z-axis rotation system and the detection electrode for the Y-axis rotation system are common electrodes, and the detection circuit is also shared. Therefore, each of the Z-axis rotation system and the Y-axis rotation system Is detected as one synthesized detection signal. Therefore, it is necessary to consider the detection sensitivity of each of the Z-axis rotation system and the Y-axis rotation system (hereinafter simply referred to as sensitivity).

FIG. 7 is a graph showing an example of detection sensitivity, detuning frequency, and sensitivity ratio of each of the Z-axis rotation system and the Y-axis rotation system of the present embodiment. The horizontal axis represents the detuning frequency (difference between detection frequency and drive frequency of the Y-axis rotation system, unit Hz), one vertical axis represents the detection sensitivity (mV / dps), and the other vertical axis represents the sensitivity ratio (Z-axis rotation system (Detection sensitivity / detection sensitivity of Y-axis rotation system, unit%).
This graph is displayed with reference to the detuning frequency of the Y-axis rotation system.

  In FIG. 7, the Z-axis sensitivity and the Y-axis sensitivity have an inclination in the opposite direction with respect to the detuning frequency, and intersect each other in the vicinity of the detuning frequency of −2000 Hz. This intersection indicates that the sensitivity ratio is 1: 1, that is, the sensitivity ratio is 100%. Therefore, if the detection frequency of the Z-axis rotation system and the Y-axis rotation system is designed to be in a substantially equal range so that the sensitivity ratio is 100%, the angular velocities of the Z-axis rotation system and the Y-axis rotation system are almost the same. Detection is possible with a degree of detection sensitivity.

  Further, depending on the usage pattern of the angular velocity sensor 1 according to the present embodiment, the sensitivity ratio may be set to a range other than 100%. If the Y-axis sensitivity is important, the detuning frequency is set in a direction close to 0. If the Z-axis sensitivity is regarded as important, the detuning frequency is set in the negative direction.

  Since the detuning frequency is expressed by the difference between the frequency of the detection signal and the driving frequency, if the weights 63 and 64 of the detection arm 60 are increased, the detuning frequency is shifted to the minus direction, and if it is decreased, it is moved to the 0 direction. By setting the width D of the weight portions 63 and 64 of the detection arm 60 to a range of 5d ≦ D ≦ 10d with respect to the width d of the detection arm portions 61 and 62 of the detection arm 60, the Z axis rotation system and the Y The angular velocities of the two axes of the shaft rotation system can be detected with good balance. The relationship between the width D of the weight parts 63 and 64 and the width of the detection arm parts 61 and 62 is a range for obtaining the detection sensitivity represented by the graph of FIG.

  Therefore, according to the above-described embodiment, the piezoelectric vibrating piece 10 is used in a conventional Z-axis rotation system single-axis angular velocity sensor, and includes a vibration component of the Y-axis rotation system and a vibration component of the Z-axis rotation system. Occurs in the common detection arm 60. Furthermore, since the detection electrode formed on the detection arm 60 and the detection circuit mounted on the semiconductor device can be configured in a common series, the Z-axis rotation system and the Y-axis rotation system with simple configurations can be configured. An angular velocity sensor 1 capable of detecting biaxial angular velocities can be provided.

  Further, a torsional vibration is generated in the detection arm 60 by the Coriolis force F given by the rotation around the Y axis, and a bending vibration is generated in the detection arm by the rotation around the Z axis. Accordingly, different vibration modes of the Y-axis rotation system and the Z-axis rotation system are generated and detected as angular velocities, so that the drive arms 40 and 50 (including the drive electrodes) and the detection arm 60 common to the one-axis rotation system are detected. (Including detection electrodes) The angular velocity sensor 1 of a biaxial rotating system can be configured.

  Further, the piezoelectric vibrating piece 10 described above has a form called a WT type, and it is known that the WT type angular velocity sensor can be miniaturized and has high detection sensitivity, and detection of the angular velocity of the biaxial rotating system of the present invention. The sensor is also small and achieves high detection sensitivity.

  The width D of the weight portion of the detection arm 60 is set in a range of 5d ≦ D ≦ 10d with respect to the width d of the detection arm portions 61 and 62 of the detection arm 60. In the piezoelectric vibrating piece in which the drive arms 40 and 50 vibrate, the detection vibration is hardly generated by the Coriolis force on the detection arm 60 in the Y-axis rotation system. However, in this embodiment, a torsional vibration component is used as the vibration component of the Y-axis rotation system, and the torsional vibration is generated by making the width D of the weight parts 63 and 64 much larger than the width d of the detection arm parts 61 and 62. It can be easily generated and the detection power can be increased.

  Normally, the sensitivity ratio between the detection sensitivity of the bending vibration component of the Z-axis rotation system and the detection sensitivity of the torsional vibration component of the Y-axis rotation system is different, but depending on the purpose and application of use of the angular velocity sensor, The detection sensitivity of each of the two axes can be set appropriately depending on which of the detections of the Z-axis rotation system is important.

  At this time, if the sensitivity ratio between the detection sensitivity of the Z-axis rotation system and the detection sensitivity of the Y-axis rotation system is approximately 1: 1 (sensitivity ratio 100%), both the Z-axis rotation system and the Y-axis rotation system are almost the same. It is possible to detect angular velocities with the same balance, and it is easy to mount on various devices.

It should be noted that the present invention is not limited to the above-described embodiment, but includes modifications and improvements as long as the object of the present invention can be achieved.
For example, in the above-described embodiment, the WT type piezoelectric vibrating piece has been described as an example. However, the present invention can also be applied to a piezoelectric vibrating piece called an H type, a tuning fork type vibrating piece, and other forms. These can be realized by designing one of the two-axis rotation systems so that the detection arm is flexibly oscillated by the Coriolis force and the other is torsionally oscillated.

  Therefore, according to the present embodiment, the piezoelectric vibrating piece for detecting the angular velocity of the uniaxial rotating system and the detecting means of one series have a small and simple structure that realizes the angular velocity detection of the Z-axis rotating system and the Y-axis rotating system. An angular velocity sensor is provided.

The above-described angular velocity sensor according to the present invention can be mounted on various electronic devices. For example, it can be applied to camera shake correction of a digital camera, an impact detection sensor such as an HDD (Hard Disk Drive), or the like.
For example, for camera shake correction of a digital camera, image blur can be suppressed by adjusting the shutter speed by detecting the angular velocity of a biaxial rotating system that affects the focal depth of the digital camera.

  In the case of a digital camera, the image is greatly affected when camera shake occurs around an axis perpendicular to the optical axis of the lens. On the other hand, camera shake around the optical axis of the lens has less influence on the image than camera shake around the axis perpendicular to the optical axis. Therefore, the above-described angular velocity sensor according to the present invention is arranged so that the X-axis direction is included in the optical axis of the lens. In this way, when an angular velocity around the Y axis and / or the Z axis occurs, the image is not affected by adjusting the exposure time to be short according to the angular velocity. When underexposure occurs, the image can be adjusted by amplifying the signal. On the other hand, since it does not react to the angular velocity around the Z axis, which is less affected by camera shake, it is possible to ensure proper exposure without adjusting the shutter speed.

  Further, in the HDD, when an impact is applied to the mounted electronic device or the like in two directions other than the horizontal direction of the HDD, the impact is sensed to prevent the HDD device from being destroyed by retracting the pickup device. It can be applied as an impact sensor.

The perspective view which shows the angular velocity sensor which concerns on embodiment of this invention. Explanatory drawing which shows typically operation | movement of the piezoelectric vibrating piece which concerns on embodiment of this invention. Explanatory drawing which shows typically operation | movement of the Z-axis | shaft rotation system which concerns on embodiment of this invention. The perspective view which shows the detection operation | movement of the Y-axis rotation system which concerns on embodiment of this invention. The upper side view which shows the state visually recognized from the upper direction (arrow A direction) of FIG. The upper side view which shows the state visually recognized from the upper direction (arrow A direction) of FIG. The graph showing one example about the detection sensitivity of each of the Z-axis rotation system which concerns on embodiment of this invention, and a Y-axis rotation system, a detuning frequency, and a sensitivity ratio.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Angular velocity sensor, 10 ... Piezoelectric vibration piece, 20 ... Base part, 40, 50 ... Drive arm, 60 ... Detection arm, 61, 62 ... Detection arm part, 63, 64 ... Weight part.

Claims (7)

A base, a drive arm extending in parallel to the Y axis from the base or a connecting arm connected to the base, and bending-vibrating in the X-axis direction perpendicular to the Y axis; and a detection arm parallel to the drive arm; A piezoelectric vibrating piece formed on the XY plane,
Both a vibration component generated in the detection arm due to Coriolis force given by rotation around the Y axis and a vibration component generated in the detection arm due to Coriolis force given by rotation around the Z axis perpendicular to the XY plane According to the detection means for outputting a detection signal;
An angular velocity sensor comprising: The angular velocity sensor according to claim 1,
The vibration component generated in the detection arm by the Coriolis force in the Z-axis direction given by the rotation about the Y-axis is a torsional vibration component,
An angular velocity sensor, wherein a vibration component generated in the detection arm by a Coriolis force in a Y-axis direction given by the rotation about the Z-axis is a bending vibration component. The angular velocity sensor according to claim 1 or 2,
A detection arm in which the piezoelectric vibrating piece extends in the Y-axis direction and the negative Y-axis direction from the base;
A first connecting arm extending from the base in the X-axis direction; a second connecting arm extending from the base in the negative X-axis direction;
A driving arm connected to the first connecting arm and extending in the Y-axis direction and the minus Y-axis direction, and a driving arm connected to the second connecting arm and extended in the Y-axis direction and the minus Y-axis direction. And an angular velocity sensor. The angular velocity sensor according to any one of claims 1 to 3,
A weight portion is formed at the tip of each of the drive arm and the detection arm,
The angular velocity sensor, wherein the width D of the weight portion of the detection arm is set in a range of 5d ≦ D ≦ 10d with respect to the width d of the detection arm portion of the detection arm. The angular velocity sensor according to any one of claims 1 to 4,
An angular velocity sensor, wherein a sensitivity ratio between a detection sensitivity of a bending vibration component of the Z-axis rotation system and a detection sensitivity of a torsional vibration component of the Y-axis rotation system is adjusted by a detuning frequency. The angular velocity sensor according to claim 5,
An angular velocity sensor, wherein a sensitivity ratio between a detection sensitivity of a bending vibration component of the Z-axis rotation system and a detection sensitivity of a torsional vibration component of the Y-axis rotation system is approximately 1: 1. A base, a drive arm extending in parallel to the Y axis from the base or a connecting arm connected to the base, and bending-vibrating in the X-axis direction perpendicular to the Y axis; and a detection arm parallel to the drive arm; A piezoelectric vibrating piece formed on the XY plane,
Both a vibration component generated in the detection arm due to Coriolis force given by rotation around the Y axis and a vibration component generated in the detection arm due to Coriolis force given by rotation around the Z axis perpendicular to the XY plane According to the detection means for outputting a detection signal;
A lens including the X-axis direction as an optical axis;
An electronic apparatus comprising:

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