JP2010054263A - Rotation oscillation gyroscope - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rotation oscillation gyroscope for eliminating effect of noise, based on a support structure of a movable section. <P>SOLUTION: The rotation oscillation gyroscope includes a drive spindle 4, a drive electrode 3 for rotating and oscillating the drive spindle 4, a detection spindle 5 that is arranged inside the drive spindle 4 and oscillates in a seesaw manner about the Y-axis together with the drive spindle 4 by Coriolis force when the angular velocity around the X-axis is received. an anchor 6 disposed projectedly on a substrate 2, a plurality of coupling support springs 8 that have an absorbing function of rotation and oscillation and a transmitting function of the Coriolis force and couple the drive spindle 4 to the detection spindle 5 and support it, a pair of twist support springs 7 that are suspended between the anchor 6 and detection spindle 5 on the Y-axis, function as a hinge shaft of the oscillating detection spindle 5, and are arranged so that the axial center pass the center of gravity of the movable section 10, and a pair of detection electrodes 9 for detecting the displacement of the oscillating detection spindle 5. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a rotational vibration type gyro which is a rotational vibration type angular velocity sensor in a micro electro mechanical system (MEMS) sensor.

As a conventional rotational vibration type gyro, there is known one in which a drive electrode is disposed inside an annular mass part (see Patent Document 1). This rotational vibration type gyro connects a fixed portion (anchor) projecting on a substrate, a flat plate-shaped mass portion (drive weight and detection weight) supported by the fixed portion, and the fixed portion and the mass portion. A radial mass support portion (support spring), a drive electrode that rotates and vibrates the mass portion, and four detection electrodes that face the mass portion are provided. When the angular velocity around the X-axis acts (angular velocity motion) in a state where the voltage is applied to the drive electrode and the mass part is rotated and oscillated, the Coriolis force is excited and the mass part becomes like a seesaw around the Y-axis. Vibrate. Due to this vibration, the capacitance changes between the mass part and the detection electrode, and the angular velocity is detected based on this change.
JP 2000-180177 A

  In such a conventional rotational vibration type gyro, the movable part is asymmetric in the Z-axis direction at the anchor portion, so that it can be set on the object in a posture other than the horizontal posture, or in the X-axis direction or the Y-axis direction. When the acceleration is received, the movable part tilts slightly due to its own weight. That is, since it is affected by the acceleration in the direction orthogonal to the Z-axis direction, this becomes noise and there is a problem that the angular velocity cannot be detected uniquely with high accuracy. In addition, since the drive weight (part) and the detection weight (part) are integrally formed, when the drive weight rotates, the detection weight also rotates. Since the Coriolis force received by the detection weight is very small, if the detection weight oscillates with the rotational vibration of the drive weight, the rotational vibration becomes noise and the angular velocity based on the Coriolis force cannot be detected accurately. there were.

  An object of the present invention is to provide a rotational vibration type gyro capable of eliminating the influence of noise based on the support structure of the movable part and the influence of noise based on the rotational vibration of the driving weight.

  The rotational vibration type gyro of the present invention is provided with a plate-shaped annular drive weight, a drive electrode for rotating the drive weight around the Z axis passing through the center thereof, an inner side of the drive weight, and receiving an angular velocity around the X axis. Plate-shaped detection weight that vibrates like a seesaw around the Y axis together with the drive weight due to Coriolis force generated at the time, an anchor projecting on the substrate and supporting the drive weight and the detection weight, and a function of absorbing rotational vibration And a Coriolis force transmission function, a plurality of connection support springs for connecting and supporting the drive weight to the detection weight, and a detection weight that is spanned between the anchor and the detection weight on the Y axis and vibrates like a seesaw. A pair of torsion support springs that function as a hinge shaft and whose axis passes through the center of gravity of a movable part including a drive weight, a detection weight, and a plurality of connection support springs, and a detection weight that vibrates like a seesaw A pair to detect the displacement of Characterized by comprising a detection electrode.

  According to this configuration, the pair of torsion support springs are disposed so as to pass through the center of gravity of the movable part including the drive weight, the detection weight, and the plurality of connection support springs. It will be supported symmetrically in the axial direction. For this reason, the influence of the noise based on the support structure of the movable part can be eliminated without being affected by the acceleration in the direction orthogonal to the Z-axis direction. In addition, since the drive weight and the detection weight are separated from each other in the direction of the rotational vibration, the detection weight does not vibrate with the rotational vibration of the drive weight, and the influence of noise based on the rotational vibration of the drive weight. Can be eliminated. Therefore, the angular velocity can be detected with high accuracy without requiring correction or the like.

  In the above-described rotational vibration type gyro, each torsion support spring extends linearly in the Y-axis direction, and the rigidity against rotational vibration around the Z-axis is higher than the rigidity against seesaw-like vibration around the Y-axis. High is preferable.

  According to this configuration, the movable portion can be stably supported by the anchor by the pair of torsion support springs, and the influence of acceleration on the detection weight can be eliminated. Further, the torsion support spring can function as a hinge that does not absorb the seesaw-like vibration of the detection weight. Therefore, the angular velocity detection sensitivity is not lowered.

  In this case, the torsion support springs are manufactured by microfabrication technology using silicon as a material, and each torsion support spring has the same thickness as the detection weight and is formed in a square cross section, and the ratio of width to thickness is 1: 2 to 10. Is preferred.

  According to this configuration, it is possible to suitably achieve the support function for the movable part and the non-absorption function for the seesaw-like vibration of the detection weight.

  On the other hand, it is preferable that the anchor corresponds to a pair of torsion support springs and is configured by a pair disposed on the Y axis.

  According to this configuration, the pair of torsion support springs can suitably achieve the above non-absorbing function with respect to the seesaw-like vibration of the detection weight, and can more stably support the movable portion with the anchor.

  Further, the anchor corresponds to the pair of torsion support springs, is constituted by a pair of elements disposed on the Y axis, and is preferably disposed at the same position as the outer peripheral edge of the detection weight in the radial direction. .

  According to this configuration, the length of the torsion support spring can be sufficiently taken without downsizing the detection weight, and the non-absorbing function for the seesaw-like vibration of the detection weight can be improved.

  Furthermore, it is preferable that the plurality of connection support springs are configured by four pieces extending in the radial direction at an angle of 45 ° with respect to the X-axis direction and the Y-axis direction.

  According to this configuration, since the driving weight is stably supported by the detection weight, the Coriolis force can be faithfully transmitted to the detection weight, and the detection sensitivity can be increased. On the other hand, since the rotational vibration of the driving weight can be absorbed, it is possible to prevent noise based on the rotational vibration from being transmitted to the detection weight, and to improve the detection accuracy.

  Similarly, the plurality of connection support springs may be composed of two pieces located on the X axis.

  According to this configuration, with a simple structure, appropriate transmission of Coriolis force to the detection weight and edge cutting of the rotational vibration to the detection weight can be achieved at the same time. In addition, since the Coriolis force with respect to the angular velocity around the Y axis (around the other axis) is difficult to transmit to the detection weight, this type of noise can also be eliminated.

  Moreover, it is preferable that each connection support spring has higher rigidity against vibration in the Z-axis direction than rigidity against rotational vibration around the Z-axis.

  According to this configuration, with the driving weight supported by the detection weight, appropriate transmission of the Coriolis force from the driving weight to the detection weight and edge cutting of the rotational vibration from the driving weight to the detection weight can be achieved simultaneously. Can do.

  In the above-mentioned rotational vibration type gyro, it is preferable that the resonance frequency of the rotational vibration in the drive weight and the resonance frequency of the vibration in the detection weight are different.

  According to this configuration, although sensitivity is lowered, variations in detection sensitivity based on manufacturing variations can be suppressed.

  Another rotational vibration type gyro of the present invention is disposed so as to surround a disk-shaped driving weight, a driving electrode for rotating the driving weight around the Z axis passing through the center thereof, and an outer side of the driving weight. A flat plate-shaped detection weight that vibrates like a seesaw around the Y axis together with the drive weight by the Coriolis force generated when the angular velocity around the axis is received, and an anchor projecting on the substrate and supporting the drive weight and the detection weight , A plurality of connection support springs that have a function of absorbing rotational vibration and connect and support the drive weight to the detection weight, and a detection weight that oscillates between the anchor and the detection weight on the Y axis and vibrates like a seesaw A pair of torsion support springs that function as a hinge shaft and whose axis passes through the center of gravity of a movable part including a drive weight, a detection weight, and a plurality of connection support springs, and a detection weight that vibrates like a seesaw A pair of detection electrodes for detecting the displacement of Characterized by comprising a.

  Also in this case, since the pair of torsion support springs are disposed so as to pass through the center of gravity of the movable part including the drive weight, the detection weight, and the plurality of connection support springs, the movable part is centered on the anchor in the Z-axis direction. Will be supported symmetrically. For this reason, the influence of the noise based on the support structure of the movable part can be eliminated without being affected by the acceleration in the direction orthogonal to the Z-axis direction. In addition, since the drive weight and the detection weight are separated from each other in the direction of the rotational vibration, the detection weight does not vibrate with the rotational vibration of the drive weight, and the influence of noise based on the rotational vibration of the drive weight. Can be eliminated. Therefore, the angular velocity can be detected with high accuracy without requiring correction or the like.

  As described above, according to the present invention, the shaft centers of the pair of torsion support springs are disposed so as to pass through the center of gravity of the movable part including the drive weight, the detection weight, and the plurality of connection support springs. The influence of noise based on the support structure of the part can be eliminated. In addition, since the drive weight and the detection weight are cut with respect to the direction of the rotational vibration, the influence of noise based on the rotational vibration of the drive weight can be eliminated. Thereby, the angular velocity can be detected with high accuracy.

  Hereinafter, a rotational vibration gyro according to an embodiment of the present invention will be described with reference to the accompanying drawings. This rotational vibration type gyroscope is a uniaxial angular velocity sensor in a micro electro mechanical system (MEMS) sensor manufactured by microfabrication technology using silicon or the like as a material, and is driven by reciprocal rotational vibrations in the normal and reverse directions. And the thing of embodiment is packaged to about 1 mm square, for example, and is commercialized. Here, the description will be made assuming that the left-right direction of the drawing is “X-axis direction”, the front-rear direction is “Y-axis direction”, and the penetration direction is “Z-axis direction”.

  As shown in FIG. 1, the rotational vibration gyro 1 includes a plurality of sets (eight sets in the embodiment) of drive electrodes 3 positioned on the outermost periphery on the substrate 2, and a plurality of sets of drive electrodes 3. A flat plate-shaped annular drive weight 4, a disk-shaped detection weight 5 widely arranged inside the drive weight 4, and a pair of anchors arranged opposite to each other on the Y axis at the outer peripheral edge of the detection weight 5 6, 6, a pair of torsion support springs 7, 7 extending between the pair of anchors 6, 6 and the detection weight 5 and extending between the drive weight 4 and the detection weight 5. A plurality of connection support springs 8 and a pair of detection electrodes 9 and 9 for detecting the displacement of the detection weight 5 are provided. In this case, the drive weight 4 and the detection weight 5 (the same applies to the torsion support spring 7 and the connection support spring 8) are made of conductive members, and the movable drive electrode 12 described later is made up of a part of the drive weight 4, The movable detection electrode 17 is constituted by a part of the detection weight 5.

  The plurality of drive electrodes 3 are arranged at equal intervals in the circumferential direction outside the drive weight 4. Each drive electrode 3 includes a fixed drive electrode 11 formed integrally on the substrate 2 and a movable drive electrode 12 provided as a part of the drive weight 4 so as to extend radially outward from the outer peripheral end of the drive weight 4. And is composed of. The fixed drive electrode 11 and the movable drive electrode 12 are opposed to each other in the form of comb teeth. When an AC voltage is applied to the fixed drive electrode 11 and the movable drive electrode 12, the drive weight 4 becomes Z by the electrostatic force generated between the electrodes 11 and 12. Vibrates around the axis.

  The drive weight 4 is formed in a flat plate ring centered on the Z axis, and the detection weight 5 is formed on a disk centered on the Z axis with a slight gap between the drive weight 4 and the drive weight 4. . The drive weight 4 and the detection weight 5 are located on the same plane and have the same thickness. Needless to say, the detection weight 5 is formed symmetrically with respect to the Y axis which is the center of the vibration (in the X axis direction).

  On the other hand, the four connection support springs 8 that connect the drive weight 4 and the detection weight 5 are arranged at an angle of 45 ° with respect to the X-axis and Y-axis directions, and have an X-shape formed on the detection weight 5. It is arranged so as to be enclosed in the four long cutouts 14. Each of the connection support springs 8 is formed into a narrow cross-sectional rectangle, and structurally, the rigidity against vibration in the Z-axis direction is higher than the rigidity against rotational vibration around the Z-axis. Thereby, the rotational vibration of the driving weight 4 is absorbed and the Coriolis force received by the driving weight 4 is transmitted to the detection weight 5. That is, due to the four connection support springs 8, the rotational vibration of the drive weight 4 is not transmitted to the detection weight 5, but the vibration due to the Coriolis force is transmitted to the detection weight 5. Thereby, the detection weight 5 vibrates like a seesaw by Coriolis force without being influenced by the rotational vibration of the drive weight 4.

  Each anchor 6 is arranged at the position of the peripheral portion of the detection weight 5 on the Y axis, and is erected integrally on the substrate 2 so as to be slightly higher than the detection weight 5. In this case, each anchor 6 is formed in a prismatic shape with a low height, and the pair of torsion support springs 7 and 7 extend from the inner surface thereof. Each torsion support spring 7 is arranged linearly on the Y-axis and is arranged so as to be included in a notch 15 that is deeply cut into the detection weight 5. Each torsion support spring 7 is spanned between the detection weights 5 and supports the detection weights 5 and the drive weights 4 connected to the detection weights 5 in a state of being lifted from the substrate 2.

  Each torsion support spring 7 is formed in a narrow cross-sectional rectangle like the connection support spring 8, supports the detection weight 5 and the drive weight 4, and vibrates in a seesaw manner by the transmitted Coriolis force. Functions as a hinge axis. That is, the torsion support spring 7 functions as a so-called torsion spring. As a result, the detection weight 5 that has received the Coriolis force vibrates like a seesaw around the pair of torsion support springs (Y-axis) 7 and 7 at one half and the other half in the X-axis direction. For this reason, in the pair of detection electrodes 9, the angular velocity is detected by taking the difference between the respective capacitance changes. Therefore, for example, even if acceleration is applied in the Z-axis direction, seesaw-like vibrations are not affected, and noise based on acceleration does not affect the detection of angular velocity.

  In this case, each torsion support spring 7 preferably has higher rigidity against rotational vibration around the Z axis than rigidity against seesaw-like vibration around the Y axis. Specifically, the width and thickness ratio is preferably 1: 2 to 1:10. More preferably, the ratio is around 1: 5.

  Further, the pair of torsion support springs 7 are arranged so that their axes pass through the center of gravity of the movable portion 10 including the drive weight 4, the detection weight 5, and the connection support spring 8. That is, the drive weight 4 including the movable drive electrode 12, the detection weight 5, the four connection support springs 8 and the pair of torsion support springs 7 are formed in the same plane with the same thickness (and the same material). The outer end portion of the support spring 7 is connected to the side surface of the anchor 6. Thereby, the movable part 10 is formed not only symmetrically in the X-axis direction and the Y-axis direction but also symmetrically in the Z-axis direction.

  The pair of detection electrodes 9 includes a pair of movable detection electrodes 17 and 17 configured by one half and the other half of the detection weight 5 in the X-axis direction. A pair of fixed detection electrodes 18 and 18 facing each other with a gap (however, larger than the amplitude of the detection weight 5). The pair of fixed detection electrodes 18 and 18 may be provided on the substrate 2 or may be provided on the inner surface of the sealing member 20 as illustrated. When the detection weight 5 vibrates like a seesaw due to Coriolis force, the capacitance between the movable detection electrode 17 and the fixed detection electrode 18 changes, and the angular velocity is detected based on this change. In the embodiment, when the driving weight 4 is rotating and oscillating, for example, when an angular velocity around the X axis is received, the detection weight 5 together with the driving weight 4 by the generated Coriolis force is as small as a seesaw around the Y axis. Vibrate. Thereby, the electrostatic capacitance of a pair of detection electrodes 9 and 9 changes, and the received angular velocity is detected.

  By the way, in such a rotational vibration type gyro 1, detection sensitivity can be improved by making the resonance frequency of the rotation vibration in the drive weight 4 and the resonance frequency of the vibration in the detection weight 5 the same. However, it is extremely difficult to make the resonance frequency the same in actual manufacturing. Therefore, in the present embodiment having good detection sensitivity, the resonance frequency of the rotational vibration in the drive weight 4 and the resonance frequency of the vibration in the detection weight 5 can be different. Thereby, although sensitivity becomes low, the variation in detection sensitivity based on the variation in manufacturing can be suppressed, and the yield of products can be improved.

  As described above, according to the present embodiment, the shaft centers of the pair of torsion support springs 7 and 7 are disposed so as to pass through the center of gravity of the movable portion 10 such as the drive weight 4 or the detection weight 5. The movable portion 10 is supported symmetrically also in the Z-axis direction around the anchor (torsion support spring 7) 6. For this reason, it is not affected by acceleration (including gravitational acceleration) in the direction orthogonal to the Z-axis direction, and the influence of noise based on the support structure of the movable portion 10 can be eliminated. Further, since the four connection support springs 8 absorb the rotational vibration of the drive weight 4, the detection weight 5 is not affected by noise based on this rotational vibration. Further, since the detection weight 5 is structured to vibrate like a seesaw, the angular velocity can be detected stably.

  Next, a modified example of the first embodiment will be described with reference to FIG. In this modification, a pair of anchors 6 and 6 are arranged back to back in the vicinity of the drive rotation center on the Y axis, and a pair of torsion support springs 7 and 7 connected thereto are connected to the anchor 6 from the anchor 6 on the Y axis. It extends in a straight line outward. Also in this case, as in the first embodiment, the pair of torsion support springs 7 and 7 has their axis passing through the center of gravity of the movable portion 10 including the drive weight 4, the detection weight 5, and the connection support spring 8. It is arranged. Therefore, even in this modification, the influence of noise based on the support structure of the movable portion 10 can be eliminated, and the angular velocity detection accuracy can be improved.

  FIG. 3 shows another modification of the first embodiment. In this modification, the connection support spring 8 is composed of two (a pair). That is, the pair of connection support springs 8 are arranged symmetrically with respect to the Y axis on the X axis. Similarly to the above, each of the connection support springs 8 is formed in a narrow cross-sectional rectangle, and is structurally configured so that the rigidity against vibration in the Z-axis direction is higher than the rigidity against rotational vibration around the Z-axis. Yes. Then, the rotational vibration of the drive weight 4 is absorbed and the Coriolis force received by the drive weight 4 is transmitted to the detection weight 5. In this case, since the drive weight 4 and the detection weight 5 are connected only in the X-axis direction, it is difficult to transmit the Coriolis force with respect to the angular velocity around the Y axis (around the other axis) to the detection weight. The noise based on the Coriolis force around the other axis can be eliminated. Therefore, the angular velocity detection accuracy can be further improved.

  Next, with reference to FIG. 4, a rotational vibration gyro 1 according to a second embodiment of the present invention will be described. In the second embodiment, unlike the rotational vibration type gyro 1 of the first embodiment, the detection weight 5 is disposed on the outer side and the driving weight 4 is disposed on the inner side. That is, the rotational vibration gyro 1 includes a flat plate-shaped annular detection weight 5 positioned on the outermost periphery on the substrate 2, a substantially disk-shaped drive weight 4 disposed inside the detection weight 5, and a drive weight. 4 on the left and right (X-axis direction) fan-shaped notch openings 21, 21 and the pair of notch portions 22, 22 of the drive weight 4 on the Y-axis. A pair of torsion support springs 7, 7 extending linearly in the Y-axis direction passed between the pair of anchors 6, 6 and the detection weight 5, the drive weight 4, and the detection weight 5 4 (plurality) of connection support springs 8 and a pair of detection electrodes 9 and 9 for detecting the displacement of the detection weight 5.

  Also in this case, the form of each anchor 6, the form of each torsion support spring 7, and the form of each connection support spring 8 are the same as those of the first embodiment including the modification and exhibit the same functions. The drive electrodes 3 and the detection electrodes 9 also have the same functions as those in the first embodiment, although the number and arrangement are different. Therefore, even in this embodiment, the influence of noise based on the support structure of the movable portion 10 can be eliminated without being affected by the acceleration in the direction orthogonal to the Z-axis direction, and the angular velocity detection accuracy can be improved. Can be improved.

  Next, a modification of the second embodiment will be described with reference to FIG. In this modification, a pair of anchors 6, 6 and a pair of torsion support springs 7, 7 are disposed outside the detection weight 5. That is, a pair of anchors 6, 6 and a pair of torsion support springs 7, 7 are disposed outside the detection weight 5 on the Y axis. Accordingly, a total of four fan-shaped notch openings 21 are formed on the X-axis and the Y-axis of the drive weight 4, and the four drive electrodes 3 are disposed in the four fan-shaped notch openings 21. ing.

  Also in the modified examples of the second embodiment, the shaft centers of the pair of torsion support springs 7 and 7 are disposed so as to pass through the center of gravity of the movable portion 10 including the drive weight 5, the detection weight 4, and the connection support spring 8. ing. Therefore, even in this modification, the influence of the noise based on the support structure of the movable portion 10 can be eliminated without being affected by the acceleration in the direction orthogonal to the Z-axis direction, and the angular velocity detection accuracy can be improved. Can be improved. Further, since the torsion support spring 7 and the anchor 6 are disposed outside the movable portion 10, the rigidity against the see-saw-like vibration around the Y axis is suppressed and the rigidity against the rotational vibration around the Z axis is increased. be able to.

It is the top view (a) and sectional drawing (b) of the rotational vibration gyroscope which concern on 1st Embodiment. It is a top view of the rotational vibration type gyro which concerns on the modification of 1st Embodiment. It is a top view of the rotational vibration type gyro which concerns on the other modification of 1st Embodiment. It is a top view of the rotational vibration type gyro according to a second embodiment. It is a top view of the rotational vibration type gyro which concerns on the modification of 2nd Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Rotation vibration type gyro 2 Board | substrate 3 Drive electrode 4 Drive weight 5 Detection weight 6 Anchor 7 Torsion support spring 8 Connection support spring 9 Detection electrode 10 Movable part

Claims (10)

A flat plate-shaped driving weight;
A drive electrode for rotating the drive weight about the Z axis passing through the center thereof;
A plate-like detection weight disposed inside the drive weight and vibrating in a seesaw-like manner around the Y axis together with the drive weight by a Coriolis force generated when an angular velocity around the X axis is received;
An anchor projecting on a substrate and supporting the drive weight and the detection weight;
A plurality of coupling support springs having a function of absorbing the rotational vibration and a function of transmitting the Coriolis force, and coupling and supporting the driving weight to the detection weight;
It functions as a hinge shaft of the detection weight that is spanned between the anchor and the detection weight on the Y axis and vibrates like a seesaw, and its axis is the drive weight, the detection weight, and the plurality of connections. A pair of torsion support springs arranged to pass through the center of gravity of the movable part including the support springs;
A rotational vibration type gyro comprising: a pair of detection electrodes for detecting displacement of the detection weight that vibrates like a seesaw.   Each of the torsion support springs extends linearly in the Y-axis direction and has higher rigidity against rotational vibration around the Z-axis than rigidity against seesaw-like vibration around the Y-axis. Item 2. The rotational vibration gyroscope according to Item 1. Manufactured by microfabrication technology using silicon,
2. The rotational vibration according to claim 1, wherein each of the torsion support springs has the same thickness as the detection weight and has a square cross section, and a ratio of width to thickness is 1: 2 to 10. Type gyro.   The rotary vibration type gyro according to claim 1, wherein the anchor corresponds to the pair of torsion support springs and is configured by a pair disposed on the Y axis. The anchor corresponds to the pair of torsion support springs, and is composed of a pair disposed on the Y axis,
2. The rotational vibration gyro according to claim 1, wherein the rotational vibration gyro is disposed at the same position as an outer peripheral edge of the detection weight in a radial direction.   2. The plurality of connection support springs are configured by four pieces extending in a radial direction at an angle of 45 ° with respect to the X-axis direction and the Y-axis direction. Rotating vibration type gyro.   The rotary vibration gyro according to claim 1, wherein the plurality of connection support springs are constituted by two pieces located on the X axis.   2. The rotational vibration gyro according to claim 1, wherein each of the connection support springs has higher rigidity against vibration in the Z-axis direction than rigidity against rotational vibration around the Z axis.   2. The rotational vibration gyro according to claim 1, wherein a resonance frequency of the rotational vibration in the driving weight is different from a resonance frequency of the vibration in the detection weight. A disk-shaped drive weight;
A drive electrode for rotating the drive weight about the Z axis passing through the center thereof;
A flat plate-shaped detection weight which is disposed so as to surround the drive weight, and vibrates like a seesaw around the Y axis together with the drive weight by a Coriolis force generated when an angular velocity around the X axis is received;
An anchor projecting on a substrate and supporting the drive weight and the detection weight;
A plurality of connection support springs having a function of absorbing the rotational vibration and connecting and supporting the drive weight to the detection weight;
It functions as a hinge shaft of the detection weight that is spanned between the anchor and the detection weight on the Y axis and vibrates like a seesaw, and its axis is the drive weight, the detection weight, and the plurality of connections. A pair of torsion support springs arranged to pass through the center of gravity of the movable part including the support springs;
A rotational vibration type gyro comprising: a pair of detection electrodes for detecting displacement of the detection weight that vibrates like a seesaw.

Images