JP2011242257A - Vibration gyro - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vibration gyro that is smaller in size than a conventional one and detects angular velocity with high accuracy.SOLUTION: In a vibration gyro 50, supports (21) of fixing structure portions for detection 2A and 2B are arranged between drive mass sections 13A and 13B that face each other along Y-axis of a rectangular coordinate system with Z-axis in a normal direction to a principal surface of a lid plate 50A. A detection mass section 17A is positioned between the drive mass section 13A and the supports (21), and a detection mass section 17B is positioned between the drive mass section 13B and the supports (21). An interdigital electrode is positioned between the supports 21 and the detection mass section 17A. Another interdigital electrode is positioned between the supports 21 and the detection mass section 17B.

Description

  The present invention relates to a vibration gyro for driving a vibrator and detecting a force acting in a direction orthogonal to the vibration direction.

  A certain type of vibrating gyroscope vibrates the vibrator with the X axis in the Cartesian coordinate system in which the main surface normal direction of the support substrate is the Z axis as the driving direction, and the vibrating gyroscope rotates around the Z axis, thereby The Coriolis force acting in the Y-axis direction orthogonal to the drive direction is detected from changes in the electrode spacing and interelectrode capacitance between the detection fixing structure and the vibrator. (For example, refer to Patent Documents 1 and 2).

Here, a configuration example of a conventional vibrating gyroscope will be described.
FIG. 1A is a plan view of a conventional vibrating gyroscope 101.

The vibration gyro 101 includes a cover plate (not shown), a support plate 102A, an outer frame portion 102B, an anchor 103A, a sub-anchor 103B, a support beam 104A, a drive beam 104B, drive mass units 105A to 105D, a detection beam 106, and a detection mass unit. 107A, 107B, detection fixing structures 108A to 108D, and driving fixing structure 110.
The outer frame portion 102B is joined to a support plate 102A and a lid plate (not shown). The anchor 103A, the sub-anchor 103B, the support beam 104A, the drive beam 104B, the drive mass units 105A to 105D, the detection beam 106, and the detection mass units 107A and 107B constitute an integrated vibrator made of a low resistance silicon material (conductive). Connected to ground.

  The drive beam 104B constituting the vibrator is supported on the support beam 104A by three sub-anchors 103B connected to the side surface in the X-axis direction with the Y-axis direction as the longitudinal direction. The support beam 104A is supported by the outer frame portion 102B with one anchor 103A connected to the side surface in the X-axis direction with the Y-axis direction as the longitudinal direction. The driving mass units 105C and 105D are arranged so as to sandwich the driving mass units 105A and 105B, and the driving mass units 105A to 105D are respectively connected between the two driving beams 104B. The detection mass units 107A and 107B are connected to the drive mass units 105A and 105B via the detection beams 106 in the openings provided in the drive mass units 105A and 105B, respectively.

The detection fixing structures 108A to 108D are arranged in the openings provided in the detection mass units 107A and 107B, spaced apart from the detection mass units 107A and 107B, and fixed to the support plate 102A and a lid plate (not shown). Is done.
The driving fixing structure portion 110 is fixed to the support plate 102A and a lid plate (not shown), and is applied with a driving voltage so as to be static between the driving mass portions 105C and 105D constituting the vibrator. Electric power works. Due to this electrostatic force, the driving mass portions 105A to 105D vibrate in the driving direction along the X axis, and the driving beam 104B is also deformed (flexed vibration) in the same direction. When the vibrating gyroscope 101 rotates around the Z axis in this state, Coriolis force in the direction along the Y axis acts on the detection mass units 107A and 107B, and the detection mass units 107A and 107B are displaced in that direction. As a result, the electrode spacing and interelectrode capacitance between the detection mass units 107A and 107B and the detection fixing structure units 108A to 108D change. At this time, in the detection mass units 107A and 107C and the detection mass units 107B and 107D, vibrations in the X-axis direction are in reverse phase, and Coriolis force acts in the reverse direction.

  In the vibration gyro 101 having the above-described configuration, the magnitude of the Coriolis force and the angular velocity is detected by detecting a change in the interelectrode capacitance between the detection mass units 107A and 107B and the detection fixing structure units 108A to 108D. Is possible.

  When the vibration gyro 101 is downsized, characteristic deterioration associated with downsizing, for example, sensitivity reduction is expected. In order to suppress a decrease in the S / N ratio due to a decrease in sensitivity, it is effective to perform CV conversion (capacitance voltage conversion) on the detection signal by a signal amplification circuit connected to the vibration gyro, and amplify the detection signal immediately thereafter. However, in the vibration gyro 101, noise due to blur in the Y-axis direction accompanying drive vibration in the X-axis direction is mixed in the detection signal after CV conversion, and thus it is necessary to amplify the detection signal after removing the noise by synchronous detection. is there.

  FIG. 1B is a plan view of a conventional vibrating gyroscope 201.

The vibration gyro 201 has a configuration in which two vibrators 202A and 202B are connected in the Y-axis direction by a connecting beam 202C. Each vibrator 202A, 202B has three mass portions 203A to 203C arranged in triplicate, and the first mass portion 203A from the outside is for driving, and is supported by the anchor 204 so as to be displaceable only in the X-axis direction. And driven in the X-axis direction by the driving fixing structure 205. The mass part 203B of the second layer is displaced by Coriolis force, and is connected and supported by the mass part 203A and the mass part 203C. The mass portion 203C in the third layer is for detection and is supported by the anchor 206 so as to be displaceable only in the Y-axis direction.
In the vibration gyro 201 having the above configuration, since the second layer mass part and the third layer mass part are formed separately, the second layer mass part has a vibration in the Y-axis direction due to drive vibration. Even if it occurs, the blur does not reach the mass part of the third layer, and the detection signal can be detected from the mass part of the third layer while suppressing the generation of noise due to the blur in the Y-axis direction. Therefore, even if the vibration gyro 201 amplifies the detection signal immediately after the CV conversion and performs the synchronous detection after the amplification, the SN ratio can be prevented from being lowered.

Japanese Patent No. 3870895 Japanese Patent No. 4290987

  In the conventional vibrating gyroscope 101, the detection fixing structure portions 108A to 108D including the detection electrodes and the support portions are provided in the openings of the two detection mass portions 107A and 107B. In such a configuration, the same number of support columns as the detection fixing structures 108 </ b> A to 108 </ b> D and the number of detection electrodes are required, which is one of the reasons why it is difficult to further reduce the size of the vibration gyro 101. .

  Further, the conventional vibration gyro 201 is provided with a connecting beam 202C that couples the vibrations of the two vibrators 202A and 202B, and connects the two. In such a structure, not only is it difficult to reduce the size, but there is a difference in the natural frequency (resonance frequency) of the two vibrators 202A and 202B due to variations in the shape of the vibrators 202A and 202B due to the connecting beam 202C. A difference occurs between the amplitudes, and the reaction force acting on the anchor 206 during drive vibration does not completely cancel out. Therefore, the residual reaction force causes vibration in the X-axis direction on the support plate, or from each of the two vibrators. The reaction force may act on the support plate as a rotational moment, and the characteristics of the vibration gyro 201 may become unstable.

  Therefore, an object of the present invention is to provide a vibrating gyroscope that can be made smaller than before and that can suppress vibration passing from a vibrator to a support plate.

  The vibration gyro of the present invention includes a support plate, a drive mass unit, a drive beam, a vibrator including a beam support unit and a detection mass unit, and a detection fixing structure unit including a support column and a detection electrode. The driving mass unit vibrates by driving. The drive beam supports the drive mass unit and bends and vibrates due to the force acting from the drive mass unit. The beam support unit fixes and supports the drive beam on the support plate. The detection mass unit is supported by the drive mass unit in a state in which the detection mass unit can be displaced by Coriolis force generated by vibration of the drive mass unit. The support column is fixedly supported by the support plate. The detection electrode is fixedly supported by the support column and has an interelectrode capacitance adjacent to the detection mass unit. In the vibration gyro configured as described above, a support column is disposed between two adjacent drive mass units in a direction orthogonal to the vibration direction of the drive mass unit, and is detected between the adjacent drive mass unit and the support column. A mass part is arranged, and a detection electrode is arranged between each of the adjacent detection mass parts and the column part.

In the fixed structure portion of the conventional configuration, one column portion and one detection electrode form a set, whereas in this configuration, one column portion and two detection electrodes form a set. Therefore, the number of support portions can be reduced as compared to the conventional case, and the area of the support plate that the support portions are required can be reduced, and the entire vibration gyro can be downsized.
Further, since the plurality of driving mass units are integrally supported by the driving beam, the substrate is not vibrated unlike the configuration in which the two vibrators are connected by the connecting beam, and the characteristics of the vibration gyro can be stabilized.

  It is preferable that the beam support portion of the present invention is disposed between the drive beam and the support column adjacent to each other in the vibration direction.

  With this configuration, it is possible to reduce the arrangement space of the beam support portion that is conventionally arranged on the outside rather than between the drive beam and the column portion, and further reduce the size of the vibration gyro.

  The vibrating gyroscope according to the present invention includes an inner support portion that supports the detection mass portion so that the detection mass portion is displaceable only in a direction perpendicular to the vibration direction with respect to the support plate, and a Coriolis acting by vibration of the drive mass portion. It is preferable to provide a connecting mass unit that is connected between the detection mass unit and the driving mass unit in a state that is displaceable with respect to a force.

  In this configuration, the detection mass unit is not shaken in the Y-axis direction due to drive vibration, and a capacitance change (noise) caused by this shake can be reduced, and a small-sized vibration gyro having a high SN ratio can be configured. .

  According to the present invention, by providing a fixed structure portion that includes one strut portion and two detection electrodes as a set, the number of strut portions is reduced as compared with the conventional configuration, and the support plate area that the strut portion has been required. The vibration gyro can be reduced in size. Further, since the plurality of driving mass units are integrally supported by the driving beam, the substrate is not vibrated unlike the configuration in which the two vibrators are connected by the connecting beam, and the characteristics of the vibration gyro can be stabilized.

It is a figure explaining the structure of the conventional vibration gyroscope. It is a figure explaining the structure of the vibration gyroscope which concerns on the 1st Embodiment of this invention. It is a figure explaining operation | movement of the vibration gyro shown in FIG. FIG. 3 is a partially enlarged view of the vibration gyro shown in FIG. 2. It is a figure explaining the circuit structure of the drive detection circuit of the vibration gyro shown in FIG. It is a figure explaining the structure of the vibration gyroscope which concerns on the 2nd Embodiment of this invention. It is a figure explaining the structure of the vibration gyroscope which concerns on the 3rd Embodiment of this invention.

  In the following description, it is assumed that the rotation detection axis of the vibration gyroscope is the Z-axis of the orthogonal coordinate system, the drive direction is the X-axis direction of the orthogonal coordinate system, and the direction of Coriolis force action is the Y-axis direction of the orthogonal coordinate system.

  2A is a plan view showing the configuration of the vibrating gyroscope 50 according to the embodiment of the present invention, and FIG. 2B is an X-axis passing through the center of the vibrator in a state where the vibrating gyroscope 50 is mounted on the mounting board. FIG.

  The vibrating gyroscope 50 has a configuration in which a lid plate 50A, a low-resistance silicon plate 50B, and a bottom plate 50C are stacked in order along the Z axis in a step view. The low-resistance silicon plate 50B is divided into the following configuration, vibrator 1, detection fixing structure portions 2A and 2B, driving fixing structure portions 3A and 3B, monitor fixing structure portions 4A and 4B, and an outer frame portion. 5 is provided. The cover plate 50A, the outer frame portion 5, and the bottom plate 50C constitute a housing having an internal space. This casing is bonded to the mounting substrate 150 on the outer main surface of the bottom plate 50C, and external connection terminals (not shown) formed on the outer main surface of the lid plate 50A are wire-bonded to mounting electrodes (not shown) on the mounting substrate 150. It is the structure to do.

The vibrator 1 is locally fixed to the cover plate 50A and the bottom plate 50C, and includes drive mass units 13A to 13D as regions that can be displaced in the X-axis direction, and detection masses as regions that can be displaced in the Y-axis direction. Units 17A and 17B are provided.
The detection fixing structures 2A and 2B are provided to detect the Coriolis force acting on the vibrator 1 by detecting the interelectrode capacitance between the detection mass parts 17A and 17B. It arrange | positions inside the center opening and is being fixed to 50A of cover plates, and the baseplate 50C so that the whole may not deform | transform.
The driving fixing structures 3A and 3B are arranged inside the openings at both ends of the Y axis provided in the vibrator 1 and fixed to the cover plate 50A and the bottom plate 50C so that the whole is not deformed. By applying a driving voltage to the driving fixing structure portions 3A and 3B, the electrostatic force between the driving fixing structure portions 3A and 3B and the driving mass portions 13A to 13D varies, and the driving mass portions 13A to 13D Vibration in the X-axis direction occurs.
The monitor fixing structures 4A and 4B are arranged on both outer sides of the Y axis with the vibrator 1 interposed therebetween, and are fixed to the cover plate 50A and the bottom plate 50C so as not to be deformed as a whole. The monitor fixing structures 4A and 4B detect the interelectrode capacitance between the driving mass parts 13C and 13D, adjust the driving voltage applied to the driving fixing structures 3A and 3B, and vibrate the vibrator 1. Is provided to make it appropriate.

  FIG. 3 is a diagram for explaining deformation due to driving of the vibrator 1. The drive mass units 13A to 13D vibrate in the X-axis direction due to fluctuations in the electrostatic force between the drive fixing structure units 3A and 3B (not shown) and the drive mass units 13A to 13D. At this time, the driving directions of the driving mass units 13A and 13D and the driving mass units 13B and 13C are reversed. In this state, when an angular velocity around the Z-axis acts on the vibrator 1, a Coriolis force acts on the detection mass units 17A and 17B. Since the driving mass units 13A and 13D and the driving mass units 13B and 13C have opposite driving directions, the Coriolis force also acts in the opposite direction, and the detection mass units 17A and 17B are displaced in the Y axis direction in opposite directions. .

Returning to FIG. 2 again, the detailed structure of the vibrating gyroscope 50 will be described.
The vibrator 1 has the following integrally formed structure, support anchors 10A to 10F, drive beams 12A and 12B, drive mass units 13A to 13D, drive comb portions 14A to 14D (partially not shown), and a detection beam 15A. , 15B, detection mass portions 17A, 17B, detection comb teeth portions 18A, 18B (partially not shown), and monitor comb teeth portions 19A, 19B (partially not shown).

The driving comb portions 14A to 14D are attached to the driving mass portions 13A to 13D, respectively. FIG. 4A is an enlarged plan view in the vicinity of the driving comb portions 14A and 14C. The driving comb portions 14B and 14D have the same configuration as the driving comb portions 14A and 14C.
The driving comb portion 14A includes a comb electrode protruding in a comb shape along the X axis from one side surface of a linear portion protruding in the Y axis positive direction from the driving mass portion 13A. The driving comb portion 14C includes a comb electrode protruding in a comb shape along the X axis from one side surface of the linear portion protruding in the Y axis negative direction from the driving mass portion 13C. The comb electrodes of the drive comb portions 14A and 14C are opposed to the comb electrodes 33 provided in the drive fixing structure portion 3A with a minute gap. The driving fixing structure 3A includes a columnar column 31 fixed to the cover plate 50A and the bottom plate 50C, a linear portion 32 connected to the column 31, and the linear portion 32 along the X axis. The driving fixing structure 3A is electrically connected to the external connection terminal by a via electrode provided on the cover plate 50A. With such a configuration, when a driving voltage (bias voltage and AC voltage) is applied between the driving comb portions 14A, 14C and the driving fixing structure portion 3A, the driving comb portions 14A, 14C and the driving fixing portion are fixed. The drive mass units 13A and 13C vibrate along the X-axis due to fluctuations in the electrostatic force with the structure unit 3A.

  Returning again to FIG. The drive mass units 13C and 13D are arranged along the Y axis so as to sandwich the drive mass units 13A and 13B. The driving mass portions 13A and 13B are substantially U-shaped with the Y-axis inner side opened in a plan view, and both arm portions are connected to the driving beams 12A and 12B via T-shaped beam portions. The driving mass portions 13C and 13D have a substantially linear shape elongated in the X-axis direction in plan view, and both ends of the X-axis are connected to both ends of the Y-axis of the driving beams 12A and 12B.

  The driving beams 12A and 12B are arranged on both outer sides of the X axis with the driving mass portions 13A to 13D interposed therebetween. Each of the driving beams 12A and 12B has a substantially linear shape that is long in the Y-axis direction when seen in a plan view, and is thus configured to be deformable (flexible vibration) in the X-axis direction. The drive beams 12A and 12B are connected to the support anchors 10A to 10F at positions that are approximately 1/4, approximately 2/4, and approximately 3/4 of the entire length in the Y-axis direction. Each of the support anchors 10 </ b> A to 10 </ b> F has a generally U shape in plan view, and fixes the drive beams 12 </ b> A and 12 </ b> B to the outer frame portion 5. The support anchors 10A to 10F constitute the beam support portion described in the claims.

  With the above-described configuration, the positions of the drive beams 12A and 12B connected to the support anchors 10A to 10F are the bending vibration nodes (node points) when the drive beams 12A and 12B are deformed (flex vibration) in the X-axis direction. Become. And the position which supports drive mass part 13A-13D becomes the antinode (antinode point) of a bending vibration, or its vicinity. Therefore, the driving mass units 13A and 13D vibrate in the same phase in the X-axis direction, and the driving mass units 13B and 13C vibrate in the opposite phase to the driving mass units 13A and 13D in the X-axis direction.

  The detection beam 15A is substantially T-shaped in plan view, and has one end connected to the center of the opening bottom of the drive mass units 13A and 13B and the other two ends connected to the detection mass units 17A and 17B. The detection beam 15B has a substantially meander shape meandering with respect to the Y axis in plan view, and has one end connected to the vicinity of the tips of both arms of the drive mass units 13A and 13B, and the other end connected to the detection mass unit 17A. 17B.

  The detection mass portions 17A and 17B are substantially U-shaped in plan view, and are arranged in the openings of the drive mass portions 13A and 13B so that the respective U-shaped openings face each other, and the detection beams 15A , 15B. The detection mass units 17A and 17B are displaceable in the Y-axis direction, and the displacement in the X-axis direction is interlocked with the drive mass units 13A and 13B.

  The detection comb-tooth portions 18A and 18B are attached in openings facing the detection mass portions 17A and 17B. FIG. 4B is an enlarged plan view in the vicinity of the detection comb portion 18A. The detection comb tooth portion 18B has the same configuration as the detection comb tooth portion 18A.

  The detection comb portion 18A includes a comb electrode protruding in a comb shape along the X axis in the opening of the detection mass portion 17A. The comb-tooth electrode of the detection comb-tooth portion 18A faces the comb-tooth electrode 23 included in the detection fixing structure portions 2A and 2B with a minute gap therebetween. The detection fixing structures 2A and 2B include the column 21 fixedly supported by the cover plate 50A and the bottom plate 50C, the linear portion 22 connected to the column 21, and the linear portion 22 along the X axis. And a comb-tooth electrode 23 (detection electrode) protruding in a comb-teeth shape. With such a configuration, when the detection mass part 17A is displaced in the Y-axis direction, the interelectrode capacitance between the detection comb part 18A and the detection fixing structure parts 2A and 2B varies.

  As shown in FIG. 2, the monitor comb teeth 19A and 19B are attached to both outer sides of the drive mass units 13C and 13D in the Y axis. As shown in FIG. 4A, the detailed configuration of the monitor comb-tooth portion 19A includes comb-tooth electrodes that project in a comb-tooth shape along the X-axis from the side surface of the linear portion extending along the Y-axis. The comb-tooth electrodes of the monitor comb-tooth portions 19A and 19B are opposed to the comb-tooth electrode 43 included in the monitor fixing structure portions 4A and 4B with a minute gap therebetween. The monitor fixing structures 4A and 4B include a column 41 fixedly supported by the cover plate 50A and the bottom plate 50C, a linear portion 42 connected to the column 41, and the linear portion 42 along the X axis. And a comb electrode 43 protruding in a comb shape. With such a configuration, when the drive mass units 13C and 13D are displaced in the X-axis direction, the interelectrode capacitance between the monitor comb portions 19A and 19B and the monitor fixing structure portions 4A and 4B varies.

  FIG. 5 is a circuit diagram of a drive detection circuit connected to the vibration gyro 50. Here, an example in which the drive detection circuit is configured as a custom IC 151 is shown. The custom IC 151 is preferably mounted on the mounting substrate 150 shown in FIG. 2B, molded integrally with the vibration gyro 50, and configured as an integrated chip element.

The custom IC 151 includes a CV conversion circuit 152, a differential amplifier 153, a synchronous detection circuit 154, a DC amplifier / low-pass filter circuit 155, a digital trimming circuit 156, an amplifier 158, an auto gain control circuit 159, and a phase shifter / sine wave generation A circuit 160 is provided.
The CV conversion circuit 152 is connected to each of the detection fixing structures 2A and 2B of the vibration gyro 50 and the monitor fixing structures 4A and 4B (or at least one of the monitor fixing structures 4A and 4B). A voltage signal corresponding to the interelectrode capacitance is output. The differential amplifier 153 outputs a differential signal of two voltage signals input from the CV conversion circuit 152. The detection electrode connected to the CV conversion circuit 152 cancels the capacitance change when the acceleration in the Y-axis direction is applied to the vibration gyro 50, and the capacitance change occurs only in the angular velocity around the Z-axis. Therefore, only the signal due to the Coriolis force is generated. Are differentially amplified. The synchronous detection circuit 154 detects from the differential signal at a timing synchronized with the sine wave generated by the phase shifter / sine wave generation circuit 160. Since the phase in the X-axis direction due to the drive and the Y-axis direction due to the Coriolis force are 90 degrees out of phase, the Y-axis except for most unnecessary signals due to vibration in the X-axis direction by performing synchronous detection. It becomes possible to selectively detect vibration due to the Coriolis force in the direction. The DC amplifier / low-pass filter circuit 155 amplifies the detection signal output from the synchronous detection circuit 154 and cuts a noise component. The digital trimming circuit 156 calibrates the characteristic variation of the vibration gyro 50 in the detection signal and outputs the detection signal. The amplifier 158 amplifies the voltage signal input from the CV conversion circuit 152 (signals from the monitor fixed structures 4A and 4B). The auto gain control circuit 159 and the phase shifter / sine wave generation circuit 160 adjust the phase and amplitude of the drive voltage so that the vibration of the vibration gyro 50 is appropriately maintained, and the fixed structure portion 3A for driving the vibration gyro 50, Output to 3B.
With such a drive detection circuit, the vibration gyro 50 vibrates in the driving direction, and an angular velocity around the Z axis acts on the vibration gyro 50 in the vibration state, whereby a detection signal corresponding to the angular velocity is obtained.

  The vibrating gyroscope 50 of the present embodiment has the above-described configuration, and the detection mass units 17A and 17B are arranged between the drive mass units 13A and 13B arranged along the Y axis, and the detection is performed between the detection mass units 17A and 17B. The fixing structure portions 2A and 2B for detection are arranged, and the fixing structure portions 2A and 2B for detection have a configuration in which comb-tooth electrodes 23 are provided on both sides in the Y-axis direction of one supporting column portion. For this reason, the vibration gyro 50 can reduce the number of support portions 21 as compared with the conventional configuration and reduce the area of the support plate.

  Next, a vibrating gyroscope 70 according to a second embodiment of the present invention will be described. FIG. 6 is a plan view showing the configuration of the vibrating gyroscope 70.

  The vibration gyro 70 includes a vibrator 61 having a shape different from that of the first embodiment, but the other schematic configuration is the same as that of the first embodiment.

The vibrator 61 includes support anchors (support beams) 60A to 60D, drive beams 62A and 62B, drive mass units 63A to 63D, drive comb portions 64A and 64B (partially not shown), a detection beam 65, and a detection mass unit 67A. 67B, detection comb teeth 68A and 68B (partially not shown), and monitor comb teeth 69A and 69B (partially not shown).
In this embodiment, the arrangement of the monitor fixing structures 4A and 4B and the driving fixing structures 3A and 3B is changed from the configuration of the first embodiment, and support anchors (support beams) 60A to 60A The structure of 60D is different.

  The support anchors 60A and 60B are disposed in a central opening provided in the vibrator 61, and are fixed to the support plate together with the support column portions of the detection fixing structure portions 2A and 2B. The support anchors 60C and 60D are disposed in the openings on both outer sides of the Y axis of the vibrator 61, and are fixed to the support plate together with the support column portions of the monitor fixing structures 4A and 4B. The movable ends of the support anchors 60A and 60B are connected to the central portion of the drive beams 62A and 62B in the Y-axis direction, and the movable ends of the support anchors 60C and 60D are 1 with respect to the total length of the drive beams 62A and 62B in the Y-axis direction. / 4 and 3/4. For this reason, the vibrating gyroscope 70 does not need to dispose a support anchor outside the vibrator 61, and can reduce the substrate area.

  Next, a vibrating gyroscope 90 according to a third embodiment of the present invention will be described. FIG. 7 is a plan view showing the configuration of the vibrating gyroscope 90.

  The vibration gyro 90 includes a vibrator 81 having a shape different from that of the above-described embodiment, but the other schematic configuration is the same as that of the above-described embodiment.

  The vibrator 81 includes support anchors (support beams) 80A to 80E, drive beams 82A and 82B, drive mass units 83A to 83D, drive comb portions 84A and 84B (partially not shown), connection mass units 86A and 86B, and detection. Mass portions 87A and 87B, detection comb teeth 88A and 88B (partially not shown), and monitor comb teeth 89A and 89B (partly not shown) are provided.

  In the present embodiment, the drive mass units 83A to 83D and the detection mass units 87A and 87B are coupled by the coupling mass units 86A and 86B, and the detection mass units 87A and 87B are supported by the support anchor 80E (inner support unit). It is characterized by being fixed with respect to.

  More specifically, the connecting mass portions 86A and 86B are substantially U-shaped with an opening on the inner side of the Y-axis, and both ends of the linear portion along the X-axis that constitutes the bottom surface of the opening are substantially T-shaped beams. Both arms of the drive mass units 83A and 83B are connected to the bottom openings of the drive mass units 83A and 83B via the substantially meander-shaped beams that meander the tips of both arms along the Y axis with respect to the Y axis. It is connected to the tip of the part. The detection mass portions 87A and 87B are connected to the linear portions along the X axis of the connection mass portions 86A and 86B via a substantially meander-shaped beam meandering the tips of both arms with respect to the X axis. The tip of the linear portion along the central Y axis is connected to the support anchor 80E via a beam having a shape in which three rectangular annular portions are connected along the Y axis.

  In this configuration, when the vibrating gyroscope 90 rotates around the Z axis while the driving mass units 83A to 83D vibrate in the X axis direction, Coriolis force in the Y axis direction acts. The drive mass units 83A to 83D are configured to be displaceable in the X-axis direction but are restricted from displacement in the Y-axis direction, and vibration in the Y-axis direction due to Coriolis force hardly occurs. The connecting mass portions 86A and 86B are configured to be displaceable in both the X-axis direction and the Y-axis direction, and vibrations are generated in both directions. The detection mass portions 87A and 87B are configured to be displaceable in the Y-axis direction but are restricted from displacement in the X-axis direction, and the vibration in the Y-axis direction of the coupling mass portions 86A and 86B acts via the beam. By doing so, it vibrates only in the Y-axis direction. For this reason, the detection mass portions 87A and 87B are hardly shaken in the Y-axis direction due to the drive vibration in the X-axis direction, and the Y acting on the vibration gyro 90 is removed except for the influence of unnecessary signals due to the shake in the Y-axis direction. It becomes possible to accurately detect the axial Coriolis force.

  In each of the above-described embodiments, the example in which both the monitor fixing structures 4A and 4B are used for vibration monitoring is shown. However, only one of them is used for vibration monitoring and the other is the same as the vibrator. A potential may be used so as to be connected to the ground electrode via the support column. In this case, it is not necessary to separately provide a via electrode by connecting the vibrator to the ground electrode via a fixed structure having the same potential as that of the vibrator, and the reduction of the support plate area can be promoted. Even if there is only one fixed structure used for vibration monitoring, it is preferable to dare to form the other fixed structure not used for vibration monitoring in order to maintain the symmetry of the vibration gyro.

DESCRIPTION OF SYMBOLS 1,61,81 ... Vibrator 10A-10D, 60A-60D, 80A-80E ... Support anchor 12A, 12B, 62A, 62B, 82A, 82B ... Drive beam 13A-13D, 63A-63D, 83A-83D ... Drive mass Part 14A, 14B, 64A, 64B, 84A, 84B ... Drive comb tooth part 15A-15D, 16A-16D, 65 ... Detection beam 17A, 17B, 67A, 67B, 87A, 87B ... Detection mass part 18A, 18B, 68A, 68B, 88A, 88B ... detection comb teeth 19A, 19B, 69A, 69B, 89A, 89B ... monitor comb teeth 2A, 2B ... detection fixing structure 3A, 3B ... driving fixing structure 4A, 4B ... for monitoring Fixed structure part 21, 31, 41 ... Column part 22, 32, 42 ... Linear part 23, 33, 43 ... Comb electrode 5 ... Outer frame part 50, 70, 90 ... vibrating gyro 50A ... lid plate 50B ... low resistance silicon plate 50C ... bottom plate

Claims (3)

A support plate;
A driving mass unit that vibrates by driving, a driving beam that supports the driving mass unit and flexes and vibrates due to a force acting from the driving mass unit, a beam support unit that fixes and supports the driving beam to the support plate, and the driving A vibrator comprising a detection mass unit supported by the drive mass unit in a freely displaceable state with respect to Coriolis force acting by vibration of the mass unit;
A supporting structure fixed to the support plate, and a detection fixing structure that includes a detection electrode that is fixedly supported by the supporting column and has a capacitance between electrodes adjacent to the detection mass unit,
The support column is disposed between two drive mass units adjacent to each other in a direction orthogonal to the vibration direction of the drive mass unit, and the detection mass unit is disposed between each of the adjacent drive mass units and the support column. A vibrating gyroscope which is arranged and the detection electrode is arranged between the adjacent support column and the detection mass unit.   The vibration gyro according to claim 1, wherein the beam support portion is disposed between the drive beam and the support column that are adjacent to each other in the vibration direction. An inner support part that supports the detection mass part so as to be displaceable only in a direction perpendicular to the vibration direction with respect to the support plate; and
The connection mass part further connected between the said detection mass part and the said drive mass part in the state which can be displaced with respect to the Coriolis force which acts by the vibration of the said drive mass part is further provided. The vibrating gyroscope described in 1.

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