Vibratory gyroscope element and angular rate sensor comprising the same

Abstract

A vibration type gyro element (100) includes a fixed portion (10), a vibrator (20) having a vibration mode of cosNθ (N is a natural number of 2 or more), a support portion (30), and an electrode (40). The electrode (40) is arranged in 4N azimuths arranged in an outer peripheral direction of the vibrator (20), respectively. The plurality of electrodes (40) includes a primary driving electrode (PD) and a secondary detection electrode (SPO). When the number of arrangement states in which the primary driving electrode (PD) is arranged in an azimuth adjacent to a clockwise side of the secondary detection electrode (SPO) is set to S1, the number of arrangement states in which the primary driving electrode (PD) is arranged in an azimuth adjacent to an anticlockwise side of the secondary detection electrode (SPO) is set to S2, and the number of secondary detection electrodes (SPO) not adjacent to the primary driving electrode (PD) is set to U, a relation of U ≥ 1 or (S1+S2)-2 ≥ |S1-S2| is satisfied.

Description

Technical Field

[0001] This disclosure relates to a vibrating gyroscope element and an angular velocity sensor including the vibrating gyroscope element. Background Technology

[0002] To date, oscillating gyroscopes have been known as gyroscope elements for use in angular velocity sensors. For example, electromagnetic gyroscopes with multiple electrodes arranged on the front of a ring oscillator and a magnetic field applied along the direction intersecting the front of the electrodes are well known (see, for example, Patent Documents 1 and 2).

[0003] In an electromagnetic gyroscope, when a magnetic field is applied, a current with a frequency equivalent to the resonant frequency of the oscillator flows to a portion of the electrodes (hereinafter referred to as the primary driving electrode) to cause the oscillator to resonate (hereinafter referred to as primary vibration). When an angular velocity is generated by applying a Coriolis force to the oscillator, the voltage generated on the other electrode (hereinafter referred to as the secondary pickoff electrode) is detected and used as a signal for calculating the angular velocity.

[0004] Patent Document 1: Japanese Patent No. 5410518

[0005] Patent Document 2: Japanese Patent Publication No. 2019-032302 Summary of the Invention

[0006] -The technical problem the invention aims to solve-

[0007] However, when the primary driving electrode and the secondary detection electrode are close together, mutual inductance may sometimes occur on the secondary detection electrode due to the alternating current flowing in the primary driving electrode, thereby inducing a voltage (hereinafter sometimes referred to as crosstalk voltage).

[0008] The crosstalk voltage is superimposed on the output signal as an error component, which causes an error in the detected angular velocity value.

[0009] This disclosure was made in view of the above-mentioned technical problems, and its object is to provide a vibrating gyroscope element and an angular velocity sensor including the vibrating gyroscope element, the vibrating gyroscope element being able to reduce the crosstalk voltage contained in the voltage generated by the secondary detection electrode.

[0010] - Technical solutions for solving technical problems -

[0011] To achieve the above objectives, the vibrating gyroscope element disclosed herein includes at least a fixed part, an oscillator, a support part, and electrodes. The support part connects the oscillator to the fixed part and supports the oscillator in a manner that allows the oscillator to vibrate. The electrodes are formed in the plane of the oscillator. When the oscillator has a vibration mode of cosNθ (N is a natural number greater than 2), the electrodes are arranged in 4N directions. In these 4N directions, the axes of the electrodes are arranged at equal angular intervals in the outer circumferential direction of the oscillator. Among the plurality of electrodes, primary driving electrodes and secondary detection electrodes are included respectively. The primary driving electrode is located in the plane of the oscillator. The primary vibration of the cosNθ mode is excited on the oscillator, and the secondary vibration of the oscillator is detected by the secondary detection electrode. The number of arrangements in which the primary driving electrode is arranged in a position adjacent to the clockwise side of the secondary detection electrode is set as S1, the number of arrangements in which the primary driving electrode is arranged in a position adjacent to the counterclockwise side of the secondary detection electrode is set as S2, and the number of secondary detection electrodes in which the primary driving electrode is not arranged in either the clockwise or counterclockwise side is set as U. When U≥1 or (S1+S2)-2≥|S1-S2| is satisfied.

[0012] The angular velocity sensor disclosed herein includes at least the vibrating gyroscope element, a primary AC power supply, a secondary detection unit, and a computation unit. The primary AC power supply applies AC current of a predetermined frequency to the primary driving electrode. The secondary detection unit detects the voltage signal generated by the secondary detection electrode. The computation unit calculates the angular velocity based on the output signal of the secondary detection unit.

[0013] -The effects of the invention-

[0014] According to the vibrating gyroscope element of this disclosure, the crosstalk voltage contained in the voltage generated by the secondary detection electrode can be reduced. According to the angular velocity sensor of this disclosure, the crosstalk voltage contained in the output signal of the vibrating gyroscope element can be reduced, thereby improving the detection accuracy of angular velocity. Attached Figure Description

[0015] Figure 1 This is a top view of the vibration-type gyroscope element according to the first embodiment.

[0016] Figure 2 yes Figure 1 A sectional view at line II-II.

[0017] Figure 3 yes Figure 1 An enlarged view of the portion enclosed by the dotted line.

[0018] Figure 4 This is a simplified diagram of the circuit block of the angular velocity sensor.

[0019] Figure 5A This is a schematic diagram showing the primary vibration state of the oscillator.

[0020] Figure 5B This is a schematic diagram showing the secondary vibration state of the oscillator.

[0021] Figure 6 This is a top view showing the location where crosstalk voltage is generated when the vibrating gyroscope element is working.

[0022] Figure 7 This is a top view showing the location where crosstalk voltage is generated when the vibrating gyroscope element used for comparison is operating.

[0023] Figure 8A This is a top view of the vibrating gyroscope element involved in Variation Example 1.

[0024] Figure 8B This is a top view of another vibrating gyroscope element involved in Variation Example 1.

[0025] Figure 8C This is a top view of another vibrating gyroscope element involved in Variation Example 1.

[0026] Figure 9A This is a top view of the vibrating gyroscope element involved in Variation Example 2.

[0027] Figure 9B This is a top view of another vibrating gyroscope element involved in Variation Example 2.

[0028] Figure 10A This is a top view of the vibrating gyroscope element involved in Variation Example 3.

[0029] Figure 10B This is a top view of another vibrating gyroscope element involved in Variation Example 3.

[0030] Figure 11A This is a top view of the vibrating gyroscope element involved in Variation Example 4.

[0031] Figure 11B This is a top view of another vibrating gyroscope element involved in Variation Example 4.

[0032] Figure 12A This is a top view of the vibrating gyroscope element involved in Variation Example 5.

[0033] Figure 12B This is a top view of another vibrating gyroscope element involved in Variation Example 5.

[0034] Figure 13 This is a diagram showing the relationship between the arrangement of the primary driving electrode and the secondary detection electrode and the conditions for reducing crosstalk voltage.

[0035] Figure 14 This is a top view of the vibration-type gyroscope element according to the second embodiment.

[0036] Figure 15 yes Figure 14 An enlarged view of the portion enclosed by the dotted line.

[0037] Figure 16 This is a simplified diagram of the circuit block of the angular velocity sensor. Detailed Implementation

[0038] The embodiments of this disclosure will now be described with reference to the accompanying drawings. It should be noted that the following description of preferred embodiments is merely illustrative in nature and is not intended to limit this disclosure, its application, or its uses.

[0039] (First Implementation)

[0040] [Structure of a Vibrating Gyroscope Element]

[0041] Figure 1 This is a top view showing the vibration-type gyroscope element according to the first embodiment. Figure 2 It is shown Figure 1 A cross-sectional view at line II-II. Figure 3 It is shown Figure 1 An enlarged view of the portion enclosed by the dotted line.

[0042] It should be noted that, for ease of explanation, in Figure 1 , Figure 3 The diagram of the magnetic field application unit 60 is omitted. Additionally, it should be noted that... Figures 1-3 The diagram schematically illustrates the structure of the vibrating gyroscope element 100, and does not precisely show the actual dimensional relationships between the components.

[0043] It should be noted that in the following description, the radial direction of the oscillator 20 is sometimes referred to as the radial direction, the outer circumferential direction of the oscillator 20 as the circumferential direction, and the direction orthogonal to the radial and circumferential directions as the axial direction. Furthermore, in the radial direction, the center side of the oscillator 20 is sometimes referred to as the inner or inner side, and the outer circumferential side of the oscillator 20 as the outer or outer side. In the axial direction, the side with the upper magnetic yoke 61 (see reference...) is sometimes... Figure 2 The side of the magnetic yoke 63 (see reference) is called the upper or upper side, and the lower magnetic yoke 63 will be provided thereon. Figure 2 The side of the component shown below is called the bottom or lower side. It should be noted that sometimes the upper surface of the components shown below is called the front, and the lower surface is called the back.

[0044] In addition, one or more primary driving electrodes are sometimes collectively referred to as primary driving electrodes (PD), and one or more secondary detection electrodes are collectively referred to as secondary detection electrodes (SPO).

[0045] like Figure 1 , Figure 2 As shown, the vibration type gyroscope element 100 has a fixing part 10, an oscillator 20, multiple support parts 30, multiple electrodes 40a to 40h, and a magnetic field application part 60.

[0046] like Figure 1 As shown, the fixing part 10 has an opening 10a in the central part, and an oscillator 20, a plurality of support parts 30, a plurality of electrodes 40a to 40h, and a magnetic field application part 60 are arranged inside the opening 10a. Additionally, as... Figure 2 As shown, the fixing part 10 is a component with a stacked structure, which is formed by sequentially stacking a first silicon layer 51, a silicon oxide layer (insulating layer) 52, and a second silicon layer 53. In addition, a silicon oxide film 54 is formed on the front side of the second silicon layer 53.

[0047] The oscillator 20 is a ring-shaped component obtained by processing the second silicon layer 53, and has a cos2θ vibration mode.

[0048] The support portion 30 is a component obtained by processing the second silicon layer 53, and is integrally formed with the oscillator 20. In addition, the support portion 30 connects the oscillator 20 to the fixing portion 10 and supports the oscillator 20 in a cantilever manner. In other words, the support portion 30 supports the oscillator 20 in a way that allows the oscillator 20 to vibrate.

[0049] like Figure 3 As shown, the plurality of support portions 30 each have a first foot 31 and a second foot 32. The first foot 31 and the second foot 32 each have a first end portion 30a and a second end portion 30b. The first end portion 30a is connected to different positions of the vibrator 20 with a first gap. The second end portion 30b is connected to different positions of the fixing portion 10 with a second gap narrower than the first gap.

[0050] Furthermore, the first foot portion 31 has a first portion 31a and a second portion 31c. The first portion 31a extends radially outward from the first end portion 30a toward the oscillator 20, and the second portion 31c bends at a first bend portion 31b, which is one end of the first portion 31a, and extends parallel to the outer periphery of the oscillator 20. Additionally, the first foot portion 31 has a third portion 31e, which bends at a second bend portion 31d, which is one end of the second portion 31c, extends radially outward toward the oscillator 20, and reaches the second end portion 30b.

[0051] Similarly, the second foot 32 has a first portion 32a and a second portion 32c. The first portion 32a extends radially outward from the first end 30a toward the oscillator 20, and the second portion 32c bends at a first bend 32b, which is one end of the first portion 32a, and extends parallel to the outer periphery of the oscillator 20. Additionally, the second foot 32 has a third portion 32e, which bends at a second bend 32d, which is one end of the second portion 32c, extends radially outward toward the oscillator 20, and reaches the second end 30b.

[0052] The second portion 31c of the first leg 31 and the second portion 32c of the second leg 32 extend to the second bends 31d and 32d respectively, close to each other. Furthermore, the third portion 31e of the first leg 31 and the third portion 32e of the second leg 32 are spaced apart by a predetermined interval and extend side-by-side from the second bends 31d and 32d to the second end 30b respectively. Additionally, the first leg 31 and the second leg 32 are arranged symmetrically about an imaginary line passing through the center of the oscillator 20 and between the respective third portions 31e and 32e of the first leg 31 and the second leg 32.

[0053] Electrodes 40a to 40h are annular conductive components formed within the surface of the oscillator 20. Furthermore, electrodes 40a to 40h are formed to extend onto the front surfaces of the support portion 30 and the fixing portion 10, respectively. For example, as... Figure 3 As shown, electrode 40d starts from the second end 30b of the first foot 31, passes through the oscillator 20 between the first foot 31 and the first end 30a, and extends to the second end 30b of the second foot 32. Electrode 40d is formed on the front side of the silicon oxide film 54. It should be noted that in the following description, unless the arrangement and function of electrodes 40a to 40h are particularly important, electrodes 40a to 40h are sometimes collectively referred to as electrode 40. Furthermore, for electrodes 40a to 40p shown later (refer to...),... Figure 14 Sometimes, they are also referred to as electrodes 40. It should be noted that some or all of the functionally identical electrodes 40 arranged in different locations are connected by wiring (not shown) provided within the fixing part 10. It should be noted that the term "location" in this specification corresponds to the "area" where the electrodes 40 are arranged; when these areas are adjacent, they are continuous. Furthermore, electrodes 40 may also be arranged across a single location. Additionally, the size of the electrodes 40 may be smaller than the size of a single location (area). Multiple electrodes 40 may also be arranged in the same location.

[0054] like Figure 1As shown, four primary driving electrodes (PDs) and four secondary detection electrodes (SPOs) are arranged alternately throughout the circumference. Each primary driving electrode (PD) is positioned 90 degrees apart from its nearest neighbor. Each secondary detection electrode (SPO) is also positioned 90 degrees apart from its nearest neighbor. Adjacent primary driving electrodes (PDs) and secondary detection electrodes (SPOs) are positioned 45 degrees apart.

[0055] It should be noted that each of the multiple electrodes 40a to 40h has electrode pads (not shown) at both ends. The four secondary detection electrodes SPO are connected in series via the electrode pads.

[0056] like Figure 2 As shown, the magnetic field applying part 60 has an upper yoke 61, a magnet 62, and a lower yoke 63. The upper yoke 61 and the lower yoke 63 are both bottomed cylindrical components formed of a magnetic material such as iron. The upper yoke 61 and the lower yoke 63 are arranged such that the cylindrical portions of the upper yoke 61 and the lower yoke 63 are axially spaced apart. Furthermore, an oscillator 20 is arranged between the cylindrical portions of the upper yoke 61 and the lower yoke 63. The oscillator 20 is arranged between the cylindrical portions of the upper yoke 61 and the lower yoke 63, respectively, with axial gaps between them.

[0057] One of the upper and lower parts of the magnet 62 is the N pole, and the other is the S pole. The magnet 62 is held by the upper yoke 61 or the lower yoke 63, or both, and is fixedly arranged inside the oscillator 20.

[0058] Magnetic flux flowing from one pole of magnet 62 passes through one of the upper yoke 61 and the lower yoke 63, and reaches the oscillator 20 and the electrodes 40a-40h formed on the front side of the oscillator 20. Further, the magnetic flux passes through the oscillator 20 and the electrodes 40a-40h, and flows into the other pole of magnet 62 via the other of the upper yoke 61 and the lower yoke 63.

[0059] In this way, the magnetic field applying part 60 applies a magnetic field to the plurality of electrodes 40a to 40h along the direction intersecting the front of the oscillator 20, which in this case is along the axial direction. It should be noted that the magnetic field applying part 60 is supported by a support substrate (not shown), thereby maintaining its position relative to the oscillator 20 in the radial and axial directions.

[0060] The vibration-type gyroscope element 100, other than the magnetic field application part 60, is a MEMS (Micro Electro Mechanical Systems) element obtained by processing a known SOI (Silicon On Insulator) substrate using microfabrication technology that applies semiconductor microfabrication technology.

[0061] The MEMS device is manufactured, for example, by thermal oxidation of an SOI substrate having a first silicon layer 51, a silicon oxide layer 52, and a second silicon layer 53, forming a silicon oxide film 54 on the front side of the second silicon layer 53.

[0062] Next, a plurality of electrodes 40a to 40h are formed on the front side of the silicon oxide film 54 using a mask pattern (not shown). For example, a metal film is attached to the front side of the silicon oxide film 54 using a mask pattern, thereby forming a plurality of electrodes 40a to 40h.

[0063] Using a different mask pattern (not shown), the silicon oxide film 54 and the second silicon layer 53 are etched and removed until the silicon oxide layer 52 is reached. After this process, a prototype of the support portion 30 and the oscillator 20 is formed.

[0064] Next, with the electrodes 40a-40h, the support portion 30, and the front surface of the oscillator 20 protected by wax or the like, the first silicon layer 51 located below the support portion 30 and the oscillator 20 is etched and removed using a mask pattern (not shown) corresponding to the opening 10a of the fixing portion 10. Further, using the same mask pattern, the silicon oxide layer 52 is etched and removed to obtain the aforementioned MEMS device.

[0065] It should be noted that the etching of the first silicon layer 51 and the silicon oxide layer 52 can be performed using either dry etching or wet etching. However, when using either etching method, it is preferable to use an etchant that has high etching selectivity for the substrate layer to be etched.

[0066] [Structure and operation of the angular velocity sensor]

[0067] Figure 4 This is a simplified diagram showing the circuit block structure of an angular velocity sensor. It should be noted that, for ease of explanation, [the diagram is simplified here]. Figure 4 The diagram only briefly shows the primary drive electrode PD and the secondary detection electrode SPO in the vibrating gyroscope element 100.

[0068] like Figure 4 As shown, the angular velocity sensor 1000 has at least a vibration-type gyroscope element 100, a primary AC power supply 200, a secondary detection unit 230, and a calculation unit 240.

[0069] Four primary drive electrodes PD are connected to the primary AC power supply 200. Four secondary detection electrodes SPO connected in series are connected to the secondary detection unit 230. In addition, the secondary detection unit 230 is connected to the arithmetic unit 240.

[0070] The following describes the operation of the angular velocity sensor 1000.

[0071] When an alternating current Ip is supplied from the primary AC power supply 200 to the primary drive electrode PD, a Lorentz force is applied to the primary drive electrode PD. The direction of this Lorentz force intersects the direction of the magnetic field applied from the magnetic field application unit 60 and the direction in which the alternating current Ip flows. In other words, the Lorentz force acts in a direction parallel to the front surface of the oscillator 20. The oscillator 20, on which the primary drive electrode PD is located, deforms under this Lorentz force. Furthermore, since the direction of the Lorentz force periodically reverses according to the frequency of the alternating current Ip, the oscillator 20 vibrates at the same frequency. In this case, the oscillator 20 vibrates in a direction parallel to its front surface.

[0072] By setting the frequency of the alternating current Ip to match the resonant frequency of the oscillator 20, the primary vibration of the cos2θ mode is excited on the oscillator 20.

[0073] Furthermore, to generate such primary vibration in the oscillator 20, the alternating current Ip needs to flow to the four primary drive electrodes PD respectively. Specifically, the alternating current Ip flowing in the four primary drive electrodes PD alternately reverses direction. To elaborate further, when viewed from above, the primary drive electrodes PD with alternating current Ip flowing clockwise and those with alternating current Ip flowing counterclockwise are arranged alternately. In the example shown in this embodiment, it is set such that the flow directions of the alternating current Ip between two primary drive electrodes PD positioned 90 degrees apart circumferentially are opposite to each other; that is, when viewed from above, the flow directions of the alternating current Ip are clockwise and counterclockwise (see reference). Figure 6 In addition, the connection relationship between the four primary drive electrodes PD and the primary AC power supply 200 only needs to meet the above settings. The four primary drive electrodes PD can be connected in series or in parallel with respect to the primary AC power supply 200.

[0074] Figure 5A The primary vibration state of the oscillator is schematically shown. Figure 5B The secondary vibration state of the oscillator is schematically shown.

[0075] like Figure 5AAs shown, the annular oscillator 20 periodically undergoes primary vibration in an elliptical shape with mutually orthogonal principal axes. However, when a Coriolis force is applied to the oscillator 20, causing an angular velocity about the axial direction, the direction of the principal axes of the aforementioned ellipse changes. Figure 1 In the case of the vibration-type gyroscope element 100 of this embodiment shown, as Figure 5B As shown, compared with the case of primary vibration, the principal axis of the ellipse changes to a position rotated by 45 degrees, and the oscillator 20 becomes a secondary vibration state.

[0076] A magnetic field is also applied to the secondary detection electrode SPO in a direction intersecting its front surface. Furthermore, corresponding to the vibration of the oscillator 20, the secondary detection electrode SPO also vibrates in a direction parallel to its front surface. As a result, a voltage is generated on the secondary detection electrode SPO corresponding to the strength of the magnetic field and its vibrational speed. Moreover, since the movement speed of the secondary detection electrode SPO differs between the primary vibration state and the secondary vibration state of the oscillator 20, the voltage generated in each state is also different.

[0077] The secondary detection unit 230 detects the voltage generated by the secondary detection electrode SPO and outputs a signal corresponding to the magnitude of the voltage to the arithmetic unit 240.

[0078] Furthermore, as mentioned above, when the angular velocity sensor 1000 is operating, forces are applied to each electrode 40, and corresponding mechanical motion axes can be imagined. In view of this, it can also be said that the arrangement orientation of the electrodes 40 is the orientation of their respective imagined motion axes (hereinafter sometimes referred to as the axes of the electrodes 40) arranged at equal angular intervals in the outer circumferential direction of the oscillator 20.

[0079] The arithmetic unit 240 determines whether the oscillator 20 is in a primary vibration state or a secondary vibration state based on the output signal of the secondary detection unit 230. Furthermore, if it is determined that the oscillator 20 is in a secondary vibration state, the arithmetic unit 240 calculates the angular velocity based on the output signal of the secondary detection unit 230.

[0080] It should be noted that the vibrating gyroscope element 100, the primary AC power supply 200, the secondary detection unit 230, and the arithmetic unit 240 can be mounted on different substrates or on the same substrate. The vibrating gyroscope element 100, the primary AC power supply 200, the secondary detection unit 230, and the arithmetic unit 240 can also be housed in different packages (not shown). Furthermore, the vibrating gyroscope element 100 and other components can be mounted on different substrates or housed in different packages. In this case, the primary AC power supply 200 can also be further mounted on different substrates or housed in different packages.

[0081] [Effects, etc.]

[0082] As described above, the vibration-type gyroscope element 100 according to this embodiment includes at least: a fixed part 10, an oscillator 20, a support part 30, and electrodes 40a to 40h. The support part 30 connects the oscillator 20 to the fixed part 10 and supports the oscillator 20 in a manner that allows the oscillator 20 to vibrate. The electrodes 40a to 40h are respectively formed in a ring shape within the surface of the oscillator 20.

[0083] When the oscillator 20 has a cos2θ vibration mode, the electrodes 40 are arranged in eight positions, which are eight positions in which the axes of the electrodes 40 are arranged at equal angular intervals along the outer periphery of the oscillator 20, or in this case at 45-degree intervals. In addition, four primary drive electrodes PD and four secondary detection electrodes SPO are alternately arranged in the eight positions.

[0084] In addition, the vibrating gyroscope element 100 also includes a magnetic field application section 60, which applies a magnetic field to eight electrodes 40a to 40h along a direction that intersects the front of the oscillator 20, which in this case is along the axial direction.

[0085] By configuring the vibrating gyroscope element 100 in this way, the crosstalk voltage contained in the voltage generated by the secondary detection electrode SPO when the vibrating gyroscope element 100 is operating can be reduced. This will be further explained with reference to the accompanying drawings.

[0086] Figure 6 The location where crosstalk voltage is generated during operation of the vibration-type gyroscope element in this embodiment is shown. Figure 7 The location of crosstalk voltage generation during operation of the vibrating gyroscope element used for comparison is shown. It should be noted that... Figure 6 , Figure 7 In the Roman numerals i to viii, the positions of electrodes 40a to 40h are indicated. This order is determined clockwise, but counter-clockwise is also possible. Furthermore, the location of the first position can be adjusted as appropriate.

[0087] In addition, Figure 6 In the accompanying figures, the arrows marked inside the primary drive electrode PD indicate the direction of the alternating current Ip. Additionally, the hollow arrows marked inside the secondary detection electrode SPO indicate the location of crosstalk voltage generation and the direction of its electromotive force.

[0088] Figure 7The illustrated vibration-type gyroscope element 110 has, for example, the same structure as the vibration-type gyroscope element disclosed in Patent Document 1. Furthermore, in this vibration-type gyroscope element 110, in addition to the primary drive electrode PD and the secondary detection electrode SPO, two other electrodes are provided. One is the primary pickoff electrode PPO, which detects the primary vibration of the oscillator 20. The other is the secondary driving electrode SD, which drives the oscillator 20 to counteract the secondary vibration generated by the oscillator 20.

[0089] like Figure 7 As shown, when viewed from above, the primary driving electrode PD, secondary driving electrode SD, primary detection electrode PPO, and secondary detection electrode SPO are arranged sequentially in eight positions in a clockwise direction. Furthermore, two of each type of electrode are arranged, with electrodes of the same type positioned 180 degrees apart circumferentially.

[0090] It should be noted that the vibration-type gyroscope element 120 and the angular velocity sensor 1100 with these four types of electrodes (PD, PPD, SD, and SPO) (see reference) Figures 14-16 The structure and operation of the ) will be described in detail in the second embodiment shown below.

[0091] In the vibrating gyroscope element 110, the primary drive electrode PD and the secondary detection electrode SPO are arranged adjacent to each other. Furthermore, the alternating current Ip flowing in the two primary drive electrodes PD are in the same direction. Figure 7 In the example shown, the direction is clockwise when viewed from above.

[0092] When an alternating current Ip flows through the primary drive electrode PD to cause the oscillator 20 to vibrate in the primary direction, a crosstalk voltage is induced in the portion of the secondary detection electrode SPO that is close to the primary drive electrode PD due to mutual inductance. It should be noted that... Figure 1 , Figure 3 It is clearly known that among the adjacent electrodes 40, the distance between the portion of the first part 32a of the second foot 32 of one electrode 40 and the portion of the first part 31a of the first foot 31 of the other electrode 40 is the closest.

[0093] from Figure 7It is clearly understood that each of the two secondary detection electrodes SPO has a primary driving electrode PD arranged adjacent to it on only one side, specifically, adjacent to it on only the clockwise side. Furthermore, the electromotive force (EMF) of the crosstalk voltage of magnitude Vspo generated by the two secondary detection electrodes SPO is in the same direction (hereinafter sometimes referred to as polarity). Therefore, when the two secondary detection electrodes SPO are connected in series, the crosstalk voltages they generate do not cancel each other out, and a crosstalk voltage of magnitude 2Vspo is superimposed on the voltage detected by the secondary detection unit 230. This crosstalk voltage is superimposed as an error on the output signal of the secondary detection unit 230, and further as an error on the angular velocity calculated by the arithmetic unit 240.

[0094] In particular, in order to enable the oscillator 20 to perform primary oscillation, the amplitude of the alternating current Ip is set to a specified value. Therefore, the magnitude of the crosstalk voltage 2Vspo also increases, and the error component of the angular velocity caused by the crosstalk voltage becomes non-negligible.

[0095] On the other hand, in the vibration-type gyroscope element 100 of this embodiment, such as Figure 6 As shown, primary drive electrodes PD are arranged adjacent to each other on both sides of the secondary detection electrode SPO, that is, primary drive electrodes PD are arranged adjacent to each other on both the clockwise and counterclockwise sides of the secondary detection electrode SPO. Furthermore, as described above, the directions of the alternating current Ip flowing in the two primary drive electrodes PD adjacent to the secondary detection electrode SPO are opposite to each other. Therefore, in one secondary detection electrode SPO, the crosstalk voltage induced in the region adjacent to the primary drive electrode PD on the clockwise side has the opposite polarity to the crosstalk voltage induced in the region adjacent to the primary drive electrode PD on the counterclockwise side. Thus, these crosstalk voltages cancel each other out. That is, the magnitude of the crosstalk voltage induced by one secondary detection electrode SPO is almost zero. This applies to each of the four secondary detection electrodes SPO included in the oscillating gyroscope element 100, therefore the magnitude of the crosstalk voltage generated in the oscillating gyroscope element 100 is almost zero. As a result, the error component superimposed on the output signal of the secondary detection unit 230 can be significantly reduced, and further, the error component superimposed on the angular velocity can be significantly reduced.

[0096] The four secondary detection electrodes SPO are preferably connected in series with each other.

[0097] In this way, the voltage signals generated by the four secondary detection electrodes SPO are added together, resulting in a larger voltage signal for detecting secondary vibrations. As a result, the signal-to-noise ratio (S / N ratio) of the output signal of the secondary detection unit 230 can be increased, thereby improving the detection accuracy of the angular velocity calculated by the calculation unit 240.

[0098] Furthermore, preferably, the support portion 30 on which the electrode 40 is arranged is composed of a first foot 31 and a second foot 32, wherein the first foot 31 has the aforementioned first to third portions 31a, 31c, and 31e, and the second foot 32 has the first to third portions 32a, 32c, and 32e. More preferably, the first foot 31 and the second foot 32 are arranged symmetrically about an imaginary line, which passes through the center of the oscillator 20 and between the third portions 31e and 32e of the first foot 31 and the second foot 32, respectively.

[0099] By configuring the support portion 30 in this way, the oscillator 20 can be supported in a manner that does not significantly affect its vibration during primary vibration. Furthermore, the support portion 30 is arranged at equal angular intervals in the circumferential direction, and the first foot 31 and the second foot 32 are symmetrically arranged about the aforementioned imaginary line, thereby enabling the oscillator 20 to be stably connected to the fixing portion 10. Thus, the oscillator 20 can stably perform primary vibration.

[0100] The angular velocity sensor 1000 of this embodiment includes at least a vibrating gyroscope element 100, a primary AC power supply 200, a secondary detection unit 230, and a calculation unit 240. The primary AC power supply 200 is used to make an AC current of a predetermined frequency flow to the primary drive electrode PD. The secondary detection unit 230 detects the voltage signal generated by the secondary detection electrode PD. The calculation unit 240 calculates the angular velocity based on the output signal of the secondary detection unit 230.

[0101] According to the angular velocity sensor 1000 of this embodiment, the crosstalk voltage contained in the output signal of the vibrating gyroscope element 100 can be reduced, thereby improving the detection accuracy of angular velocity.

[0102] <Variation Example 1>

[0103] Figure 8A This is a top view showing the vibrating gyroscope element involved in this variation. Figure 8B This is a top view showing another vibrating gyroscope element. Figure 8C This is a top view showing yet another vibrating gyroscope element. It should be noted that... Figures 8A to 8C In the accompanying drawings shown thereafter, the same symbols are used for the same parts as in the first embodiment, and detailed descriptions are omitted.

[0104] exist Figures 8A to 8C The structure shown has three primary drive electrodes PD, which differs from the structure shown in the first embodiment. The directions of the alternating current Ip flowing in the three primary drive electrodes PD are respectively... Figure 6 The directions shown are the same.

[0105] exist Figure 8A In the structure shown, three primary driving electrodes (PDs) and four secondary detection electrodes (SPOs) are arranged alternately in the circumferential direction. Specifically, the secondary detection electrodes (SPOs) are arranged at the first, third, fifth, and seventh positions, and the primary driving electrodes (PDs) are arranged at the second, fourth, and sixth positions.

[0106] It should be noted that the type of electrode 40h arranged in the eighth position is not explicitly shown; for example, it is not explicitly shown whether it is the primary drive electrode PD or the secondary detection electrode SPO. Electrode 40h is a so-called dummy electrode set up to make the mass balance of the oscillator 20 equal, and it does not help in the detection of the primary and secondary vibrations of the oscillator 20. In the following figures, the type of electrode 40 is also not explicitly shown, which is also a dummy electrode. However, other functions can be given to these dummy electrodes. For example, the dummy electrode can also be the aforementioned primary detection electrode PPO or secondary drive electrode SD.

[0107] exist Figure 8A In the structure shown, primary driving electrodes PD are arranged on both sides of the secondary detection electrodes SPO located at the third and fifth positions, respectively. Therefore, the crosstalk voltage induced by these two secondary detection electrodes SPO is almost zero.

[0108] On the other hand, for the secondary detection electrode SPO located in the first position, the primary driving electrode PD is arranged adjacent to it on the clockwise side. For the secondary detection electrode SPO located in the seventh position, the primary driving electrode PD is arranged adjacent to it on the counterclockwise side. Figure 8A As shown, the crosstalk voltages induced by the two secondary detection electrodes SPO are the same in magnitude, Vspo, but with opposite polarities. Therefore, the crosstalk voltages between the secondary detection electrodes SPO arranged in the first and seventh positions cancel each other out and are almost zero. In other words, the voltage generated by the four secondary detection electrodes SPO connected in series contains almost no crosstalk voltage.

[0109] exist Figure 8B The structure shown includes three primary driving electrodes (PDs) and three secondary detection electrodes (SPOs). Specifically, the secondary detection electrodes (SPOs) are arranged at the first, third, and seventh positions, while the primary driving electrodes (PDs) are arranged at the second, fourth, and sixth positions. Electrodes 40e and 40h, arranged at the fifth and eighth positions, are dummy electrodes.

[0110] In this case, primary drive electrodes PD are arranged on both sides of the secondary detection electrode SPO located at the third position. As a result, the crosstalk voltage induced by the secondary detection electrode SPO is almost zero.

[0111] On the other hand, for the secondary detection electrode SPO located in the first position, the primary driving electrode PD is arranged adjacent to it on the clockwise side. For the secondary detection electrode SPO located in the seventh position, the primary driving electrode PD is arranged adjacent to it on the counterclockwise side. Figure 8B As shown, the crosstalk voltages induced by the two secondary detection electrodes SPO are the same in magnitude, Vspo, but with opposite polarities. Therefore, the crosstalk voltages between the secondary detection electrodes SPO arranged in the first and seventh positions cancel each other out and are almost zero. In other words, the voltage generated by the three secondary detection electrodes SPO connected in series contains almost no crosstalk voltage.

[0112] On the other hand, Figure 8C In the structure shown, the number of primary driving electrodes PD and secondary detection electrodes SPO is related to... Figure 8B The number of electrodes shown is the same. However, the arrangement of these electrodes differs: the secondary detection electrode SPO is arranged in the first, third, and fifth positions, while the primary driving electrode PD is arranged in the second, fourth, and sixth positions. Electrodes 40g and 40h, arranged in the seventh and eighth positions, are dummy electrodes.

[0113] In this case, primary drive electrodes PD are arranged on both sides of the secondary detection electrodes SPO located at the third and fifth positions, respectively. As a result, the crosstalk voltage induced by these two secondary detection electrodes SPO is almost zero.

[0114] On the other hand, for the secondary detection electrode SPO arranged in the first position, the primary driving electrode PD is arranged adjacent to it on the clockwise side. In this case, the crosstalk voltage induced by the secondary detection electrode SPO arranged in the first position is not zero, but a voltage of magnitude Vspo remains. That is, the voltage generated by the three secondary detection electrodes SPO connected in series contains a crosstalk voltage of magnitude Vspo.

[0115] <Variation Example 2>

[0116] Figure 9A This is a top view showing the vibrating gyroscope element involved in this variation. Figure 9B This is a top view showing another vibrating gyroscope element.

[0117] exist Figure 9A and Figure 9B In the structure shown, two primary driving electrodes (PD) and two secondary detection electrodes (SPO) are each provided, which differs from the structure shown in the first embodiment. The direction of the alternating current Ip flowing in the two primary driving electrodes (PD) is different from that in the second embodiment. Figure 6 The directions shown are the same.

[0118] exist Figure 9A In the structure shown, two sets of electrodes 40, consisting of a primary driving electrode PD and a secondary detection electrode SPO adjacent to each other, are arranged circumferentially. Specifically, the secondary detection electrode SPO is arranged at the first and fifth positions, and the primary driving electrode PD is arranged at the second and fourth positions. Electrodes 40c, 40f, 40g, and 40h, respectively arranged at the third position and the sixth to eighth positions, are dummy electrodes.

[0119] exist Figure 9A In the structure shown, for the secondary detection electrode SPO located in the first position, the primary driving electrode PD is arranged adjacent to it on the clockwise side. For the secondary detection electrode SPO located in the fifth position, the primary driving electrode PD is arranged adjacent to it on the counterclockwise side. On the other hand, as... Figure 9A As shown, the crosstalk voltages induced by the two secondary detection electrodes SPO are the same in magnitude, Vspo, but with opposite polarities. Therefore, the crosstalk voltages between the secondary detection electrodes SPO arranged in the first and fifth positions cancel each other out and are almost zero. In other words, the voltage generated by the two secondary detection electrodes SPO connected in series contains almost no crosstalk voltage.

[0120] exist Figure 9B In the structure shown, the secondary detection electrode SPO is arranged at the third and seventh positions, and the primary driving electrode PD is arranged at the second and fourth positions. Electrodes 40a, 40e, 40f, and 40h, respectively arranged at the first, fifth, sixth, and eighth positions, are dummy electrodes.

[0121] In this case, primary drive electrodes PD are arranged on both sides of the secondary detection electrode SPO located at the third position. As a result, the crosstalk voltage induced by the secondary detection electrode SPO is almost zero.

[0122] On the other hand, for the secondary detection electrode SPO located at the seventh position, there are no primary driving electrodes PD arranged adjacent to each other on either side. Therefore, the crosstalk voltage induced by this secondary detection electrode SPO is almost zero. In other words, the voltage generated by the two secondary detection electrodes SPO connected in series contains almost no crosstalk voltage.

[0123] <Variation Example 3>

[0124] Figure 10A This is a top view showing the vibrating gyroscope element involved in this variation. Figure 10B This is a top view showing another vibrating gyroscope element.

[0125] exist Figure 10A and Figure 10BThe structure shown is the same as that shown in Modification 2, with two primary driving electrodes PD and two secondary detection electrodes SPO. The direction of the alternating current Ip flowing in the two primary driving electrodes PD is... Figure 6 The directions shown are the same.

[0126] exist Figure 10A In the structure shown, two sets of electrodes, consisting of a primary driving electrode PD and a secondary detection electrode SPO arranged adjacent to each other, are arranged circumferentially. Specifically, the secondary detection electrode SPO is arranged at the first and seventh positions, and the primary driving electrode PD is arranged at the second and sixth positions. Electrodes 40c, 40d, 40e, and 40h, respectively arranged at the third to fifth positions and the eighth position, are dummy electrodes.

[0127] exist Figure 10A In the structure shown, for the secondary detection electrode SPO located in the first position, the primary driving electrode PD is arranged adjacent to it on the clockwise side. For the secondary detection electrode SPO located in the seventh position, the primary driving electrode PD is arranged adjacent to it on the counterclockwise side. On the other hand, as... Figure 10A As shown, the crosstalk voltages induced by the two secondary detection electrodes SPO are the same in magnitude, Vspo, but with opposite polarities. Therefore, the crosstalk voltages between the secondary detection electrodes SPO arranged in the first and seventh positions cancel each other out and are almost zero. In other words, the voltage generated by the two secondary detection electrodes SPO connected in series contains almost no crosstalk voltage.

[0128] exist Figure 10B In the structure shown, the secondary detection electrode SPO is arranged at the first and third positions, and the primary driving electrode PD is arranged at the second and sixth positions. The electrodes 40d, 40e, 40g, and 40h, which are arranged at the fourth and fifth positions, and the seventh and eighth positions, respectively, are dummy electrodes.

[0129] exist Figure 10B In the structure shown, for the secondary detection electrode SPO located at the first position, the primary driving electrode PD is arranged adjacent to it on the clockwise side. For the secondary detection electrode SPO located at the third position, the primary driving electrode PD is arranged adjacent to it on the counterclockwise side. On the other hand, as... Figure 10B As shown, the crosstalk voltages induced by the two secondary detection electrodes SPO are the same in magnitude, Vspo, but with opposite polarities. Therefore, the crosstalk voltages between the secondary detection electrodes SPO arranged at the first and third positions cancel each other out and are almost zero. In other words, the voltage generated by the two secondary detection electrodes SPO connected in series contains almost no crosstalk voltage.

[0130] <Variation Example 4>

[0131] Figure 11A This is a top view showing the vibrating gyroscope element involved in this variation. Figure 11B This is a top view showing another vibrating gyroscope element.

[0132] exist Figure 11A and Figure 11B The structure shown is the same as that shown in Modification 2, with two primary driving electrodes PD and two secondary detection electrodes SPO. The direction of the alternating current Ip flowing in the two primary driving electrodes PD is... Figure 6 The directions shown are the same.

[0133] exist Figure 11A In the structure shown, the secondary detection electrode SPO is arranged at the first and seventh positions, and the primary driving electrode PD is arranged at the second and fourth positions. Electrodes 40c, 40e, 40f, and 40h, respectively arranged at the third and fifth positions, and the sixth and eighth positions, are dummy electrodes.

[0134] For the secondary detection electrode SPO located at the seventh position, there are no primary driving electrodes PD arranged adjacent to each other on either side. As a result, the crosstalk voltage induced by this secondary detection electrode SPO is almost zero.

[0135] On the other hand, for the secondary detection electrode SPO arranged in the first position, the primary driving electrode PD is arranged adjacent to it on the clockwise side. In this case, the crosstalk voltage induced by the secondary detection electrode SPO arranged in the first position is not zero, but a voltage of magnitude Vspo remains. That is, the voltage generated by the two secondary detection electrodes SPO connected in series contains a crosstalk voltage of magnitude Vspo.

[0136] exist Figure 11B In the structure shown, the secondary detection electrode SPO is arranged at the first and third positions, and the primary driving electrode PD is arranged at the second and fourth positions. The electrodes 40e, 40f, 40g, and 40h, respectively, arranged at the fifth to eighth positions, are dummy electrodes.

[0137] exist Figure 11B In the structure shown, primary driving electrodes PD are arranged on both sides of the secondary detection electrode SPO located at the third position. Therefore, the crosstalk voltage induced by the secondary detection electrode SPO is almost zero.

[0138] On the other hand, for the secondary detection electrode SPO arranged in the first position, the primary driving electrode PD is arranged adjacent to it on the clockwise side. In this case, the crosstalk voltage induced by the secondary detection electrode SPO arranged in the first position is not zero, but a voltage of magnitude Vspo remains. That is, the voltage generated by the two secondary detection electrodes SPO connected in series contains a crosstalk voltage of magnitude Vspo.

[0139] <Variation Example 5>

[0140] Figure 12A This is a top view showing the vibrating gyroscope element involved in this variation. Figure 12B This is a top view showing another vibrating gyroscope element.

[0141] exist Figure 12A and Figure 12B The structure shown is the same as that shown in Modification 2, with two primary driving electrodes PD and two secondary detection electrodes SPO. The direction of the alternating current Ip flowing in the two primary driving electrodes PD is... Figure 6 The directions shown are the same.

[0142] exist Figure 12A In the structure shown, the secondary detection electrode SPO is arranged at the first and fifth positions, and the primary driving electrode PD is arranged at the third and seventh positions. Electrodes 40b, 40d, 40f, and 40h, respectively arranged at the second, fourth, sixth, and eighth positions, are dummy electrodes.

[0143] In other words, the two primary driving electrodes PD are arranged opposite each other at a circumferential distance of 180 degrees. Similarly, the two secondary detection electrodes SPO are arranged opposite each other at a circumferential distance of 180 degrees. The secondary detection electrode SPO is arranged at a circumferential distance of 90 degrees from the primary driving electrode PD.

[0144] For either of the secondary detection electrodes SPOs arranged in the first and fifth positions, there are no primary drive electrodes PDs arranged adjacent to each other on either side. Therefore, the crosstalk voltage induced by this secondary detection electrode SPO is almost zero. In other words, the voltage generated by the two secondary detection electrodes SPOs connected in series contains almost no crosstalk voltage.

[0145] exist Figure 12B In the structure shown, the secondary detection electrode SPO is arranged at the first and third positions, and the primary driving electrode PD is arranged at the fifth and seventh positions. Electrodes 40b, 40d, 40f, and 40h, respectively arranged at the second, fourth, sixth, and eighth positions, are dummy electrodes.

[0146] In other words, the two primary driving electrodes (PDs) are arranged 90 degrees apart circumferentially. Similarly, the two secondary detection electrodes (SPOs) are arranged 90 degrees apart circumferentially. The primary driving electrodes (PDs) and secondary detection electrodes (SPOs) are arranged opposite each other at a circumferential distance of 180 degrees.

[0147] For either of the secondary detection electrodes SPOs arranged in the first and third positions, there are no primary drive electrodes PDs arranged adjacent to each other on either side. Therefore, the crosstalk voltage induced by this secondary detection electrode SPO is almost zero. In other words, the voltage generated by the two secondary detection electrodes SPOs connected in series contains almost no crosstalk voltage.

[0148] (Summary of the first embodiment and variations 1 to 5)

[0149] Depending on the arrangement and number of the primary drive electrodes PD, the oscillator 20 can adopt a vibration mode of cosNθ (where N is a natural number greater than or equal to 2). In this case, there are 4N arrangement positions assigned to each electrode 40. The examples shown in the first embodiment and variations 1 to 5 are all equivalent to the case where N = 2.

[0150] Including cases where N≥3, if the examples shown in the first embodiment and variations 1 to 5 above are considered in a typological manner, the arrangement of the primary drive electrode PD and the secondary detection electrode SPO used to reduce crosstalk voltage satisfies either of the following equations (1) or (2).

[0151] U≥1……(1)

[0152] (S1+S2)-2≥|S1-S2|......(2)

[0153] Here, S1 is the number of arrangement states in which the primary driving electrode PD is arranged in a position adjacent to the secondary detection electrode SPO on the clockwise side. S2 is the number of arrangement states in which the primary driving electrode PD is arranged in a position adjacent to the secondary detection electrode SPO on the counterclockwise side. In the following description, these are sometimes referred to simply as the number of arrangement states S1 and the number of arrangement states S2. Additionally, U is the number of secondary detection electrodes SPO in which the primary driving electrode PD is not arranged in either the position adjacent to the clockwise side or the position adjacent to the counterclockwise side.

[0154] It should be noted that, in this application specification, when a primary driving electrode PD is arranged adjacent to both sides of a secondary detection electrode SPO, both the arrangement state number S1 and the arrangement state number S2 are counted as "1". In this case, since the primary driving electrode PD is adjacent to the clockwise side of the secondary detection electrode SPO, the arrangement state number S1 is "1". In addition, since the primary driving electrode PD is also adjacent to the counterclockwise side of the same secondary detection electrode SPO, the arrangement state number S2 is also "1".

[0155] Based on the above, equations (1) and (2) will be further explained.

[0156] First, as explained in variations 2, 4, and 5, secondary detection electrodes SPOs where no primary drive electrode PD is arranged in either the clockwise or counterclockwise orientation will not generate crosstalk voltage. In other words, if more than one of the multiple secondary detection electrodes SPOs included in the vibrating gyroscope element 100 meets this condition, the total crosstalk voltage will decrease. Specifically, if equation (1) is satisfied, the crosstalk voltage contained in the total value of the voltages generated by the secondary detection electrodes SPOs will decrease.

[0157] On the other hand, as described above, the voltages generated by the multiple secondary detection electrodes SPO are summed. Therefore, the sum of the crosstalk voltage generated by the secondary detection electrode SPO when the primary driving electrode PD is positioned adjacent to the clockwise side of the secondary detection electrode SPO, and the crosstalk voltage generated by the secondary detection electrode SPO when the primary driving electrode PD is positioned adjacent to the counterclockwise side of the secondary detection electrode SPO, is the sum of the crosstalk voltages contained in the total value of the voltages generated by the secondary detection electrodes SPO.

[0158] Therefore, it can be said that (S1+S2) corresponds to the maximum value of the crosstalk voltage contained in the total value of the voltage generated by the secondary detection electrode SPO.

[0159] Here, as described above, when the primary driving electrode PD is arranged adjacent to the secondary detection electrode SPO on the clockwise side and when the primary driving electrode PD is arranged adjacent to the secondary detection electrode SPO on the counterclockwise side, the polarities of the generated crosstalk voltages are opposite.

[0160] Therefore, ((S1+S2)-2) shown in Equation (2) implies a case where crosstalk voltage cancellation occurs, that is, there is a set of crosstalk voltage cancellations between the secondary detection electrodes SPO. In other words, ((S1+S2)-2) shown in Equation (2) corresponds to the magnitude of the crosstalk voltage contained in the total value of the voltages generated by the secondary detection electrodes SPO when a crosstalk voltage is reduced due to a cancellation.

[0161] On the other hand, |S1-S2| shown in Equation (2) corresponds to the magnitude of the net crosstalk voltage contained in the total value of the voltage generated by the secondary detection electrode SPO after removing the actual cancellation amount.

[0162] Therefore, equation (2) implies that among multiple secondary detection electrodes SPO, there is more than one secondary detection electrode SPO where crosstalk voltage cancellation occurs. In other words, if equation (2) is satisfied, the crosstalk voltage contained in the total value of the voltages generated by the secondary detection electrodes SPO is reduced.

[0163] Figure 13 The relationship between the arrangement of the primary driving electrode and the secondary detection electrode and the conditions for reducing crosstalk voltage is shown.

[0164] from Figure 13 It is clear that in most of the examples shown in the first embodiment and variations 1 to 5, the relationship shown in equation (2) is satisfied. That is, it is equivalent to the arrangement state numbers S1 and S2 being greater than or equal to 1, resulting in cancellation and a reduction in crosstalk voltage.

[0165] On the other hand, in variation 4 Figure 11A and variation example 5 Figure 12A and Figure 12B The examples shown do not satisfy the relationship shown in equation (2), but they do satisfy the relationship shown in equation (1). In these cases, from Figure 13 It is clear that, with Figure 7 Compared to the comparative example shown, the crosstalk voltage is reduced.

[0166] It should be noted that, as can be clearly seen from the explanation of equation (2), if the number of arrangement states S1 and the number of arrangement states S2 are the same, that is, if S1 = S2, then the net crosstalk voltage contained in the total value of the voltage generated by the secondary detection electrode SPO is zero, and the crosstalk voltage is reduced to the maximum extent.

[0167] from Figure 13 It is clear that, Figure 6 , Figure 8A , Figure 8B , Figure 9A , Figure 9B , Figure 10A , Figure 10B The example shown meets this condition (S1 = S2). Additionally, if the case of S1 = S2 = 0 is also included, then... Figure 12A , Figure 12B The example shown also meets this condition.

[0168] Furthermore, if the vibration-type gyroscope element 100 shown in the first embodiment and variations 1 to 5 is reviewed, the following conclusions can be drawn regarding the arrangement relationship between the primary drive electrode PD and the secondary detection electrode SPO.

[0169] <Condition A>

[0170] In a continuous sequence of orientations from the first to the Kth (K is an odd number and 3≤K≤4N-1), the electrodes 40 arranged in the first and Kth orientations are either primary driving electrodes PD or secondary detection electrodes SPO. From either a clockwise or counterclockwise perspective, in each of the first to the Kth electrodes 40, at least one primary driving electrode PD and a secondary detection electrode SPO are alternately arranged in adjacent areas.

[0171] Condition A implies that there is more than one secondary detection electrode SPO whose crosstalk voltage is canceled. It is clear from this that if this condition is met, then the relationship shown in equation (2) above is satisfied.

[0172] It should be noted that, Figure 6 , Figures 8A to 8C , Figure 9A , Figure 10A , Figure 10B and Figure 11B The example shown satisfies condition A. It should be noted that, in Figure 9B In the middle, if relative to the location Figure 6 The position of the secondary detection electrode SPO in the original first position, adjacent to the primary driving electrode PD in the counterclockwise direction, is taken as the first position. Figure 9B The structure shown also satisfies condition A.

[0173] The arrangement of the primary driving electrode PD and the secondary detection electrode SPO that satisfies condition A is further classified as shown below. However, there may also be arrangements of the primary driving electrode PD and the secondary detection electrode SPO that satisfy both conditions A1 and A2.

[0174] <Condition A1>

[0175] There are two or more combinations of primary driving electrode PD and secondary detection electrode SPO adjacent to each other on only one side, satisfying the following conditions. First, in this electrode combination, the primary driving electrode PD and the secondary detection electrode SPO are adjacent to each other. Furthermore, in this case, the secondary detection electrodes SPO included in each group are arranged at an orientation separated by (360 / 2N + 360 × (M / 2N)) degrees, and the primary driving electrode PD is arranged at an orientation separated by (360 / N + 360 × (M / 2N)) degrees or (360 × (M / 2N)) degrees (see reference). Figure 8A , Figure 8B , Figure 10A However, the secondary detection electrodes SPO are arranged in an angular range greater than 0 degrees and less than 360 degrees apart. Similarly, the primary drive electrodes PD are arranged in an angular range greater than 0 degrees and less than 360 degrees apart. It should be noted that here, M is an integer greater than 0.

[0176] <Condition A2>

[0177] There are two or more combinations of primary driving electrodes (PDs) and secondary detection electrodes (SPOs) that are adjacent to each other on only one side, satisfying the following conditions. First, in this electrode combination, the primary driving electrode (PD) and the secondary detection electrode (SPO) are adjacent. Furthermore, in this case, the primary driving electrodes (PDs) included in each group are arranged at an orientation separated by (360 / 2N + 360 × (M / 2N)) degrees, and the secondary detection electrodes (SPOs) are arranged at an orientation separated by (360 / N + 360 × (M / 2N)) degrees or (360 × (M / 2N)) degrees (see reference). Figure 9A However, the primary driving electrodes PD are arranged in an angular range greater than 0 degrees and less than 360 degrees apart. Similarly, the secondary detection electrodes SPO are arranged in an angular range greater than 0 degrees and less than 360 degrees apart.

[0178] <Condition A3>

[0179] For at least one secondary detection electrode SPO, a primary driving electrode PD is arranged in both the direction adjacent to its clockwise side and the direction adjacent to its counterclockwise side. (Ref) Figure 6 , Figures 8A to 8C , Figure 9B , Figure 11B It should be noted that, Figure 6 The example shown is for the case of N=2, where 2N primary driving electrodes PD and 2N secondary detection electrodes SPO are arranged alternately in 4N orientations.

[0180] (Second Implementation)

[0181] Figure 14This is a top view showing the vibration-type gyroscope element according to this embodiment. Figure 15 It is shown Figure 14 An enlarged view of the portion enclosed by the dotted line. Figure 16 This is a simplified structural diagram of the circuit block for an angular velocity sensor. It should be noted that, for ease of explanation, [the diagram is not translated here]. Figure 4 The same, in Figure 16 The electrodes PD, PPO, SD, and SPO in the vibrating gyroscope element 120 are only briefly shown in the diagram.

[0182] exist Figure 14 , Figure 15 The vibration-type gyroscope element 120 of this embodiment shown here is provided with the aforementioned secondary drive electrode SD and primary detection electrode PPO, which differs from the vibration-type gyroscope element 100 shown in the first embodiment. It should be noted that the number and arrangement of the primary drive electrode PD and the secondary detection electrode SD are the same as those shown in the first embodiment. Therefore, the vibration-type gyroscope element 120 has sixteen electrodes 40a to 40p.

[0183] Furthermore, in the vibrating gyroscope element 120, the primary detection electrode PPO is arranged in the same orientation as the primary drive electrode PD, and the secondary drive electrode SD is arranged in the same orientation as the secondary detection electrode SPO. This will be explained further.

[0184] like Figure 15 As shown, the two electrodes 40d and 40l are formed to extend side by side with a gap between them in the planes of the support portion 30 and the oscillator 20. Similarly, the two electrodes 40e and 40m are formed to extend side by side with a gap between them in the planes of the support portion 30 and the oscillator 20. It should be noted that, in this application specification, "side by side" includes not only the case where the two components are arranged parallel to each other, but also the case where the two components are arranged with a gap between them to a degree that they do not contact or intersect each other.

[0185] exist Figure 15 In this gyroscope element 120, among the two electrodes 40d and 40l arranged in a ring on the front side of a support portion 30, the outer electrode 40d is the primary drive electrode PD, and the inner electrode 40l is the primary detection electrode PPO. Similarly, among the two electrodes 40e and 40m arranged in a ring on the front side of another support portion 30, the outer electrode 40e is the secondary drive electrode SD, and the inner electrode 40m is the secondary detection electrode SPO. In this gyroscope element 120, the combinations of the primary drive electrode PD and the primary detection electrode PPO, and the combinations of the secondary drive electrode SD and the secondary detection electrode SPO, are provided in equal numbers.

[0186] In addition, Figure 16The angular velocity sensor 1100 of this embodiment also includes a primary detection unit 210 and a secondary AC power supply 220, which differs from the angular velocity sensor 1000 shown in the first embodiment. That is, the angular velocity sensor 1100 of this embodiment includes at least a vibrating gyroscope element 120, a primary AC power supply 200, a primary detection unit 210, a secondary AC power supply 220, a secondary detection unit 230, and a processing unit 240.

[0187] Four primary drive electrodes PD are connected to the primary AC power supply 200. Four primary detection electrodes PPO connected in series are connected to the primary detection unit 210. Four secondary drive electrodes SD are connected to the secondary AC power supply 220. Four secondary detection electrodes SPO connected in series are connected to the secondary detection unit 230. Additionally, the secondary AC power supply 220 is connected to the arithmetic unit 240.

[0188] The following describes the operation of the angular velocity sensor 1100.

[0189] The alternating current Ip flows in the primary driving electrode PD, thereby exciting a primary vibration in the cos2θ mode on the oscillator 20; and when the oscillator 20 generates an angular velocity and undergoes secondary vibration, a voltage signal corresponding to the magnitude of the secondary vibration is generated on the secondary detection electrode SPO. These two points are the same as in the first embodiment.

[0190] The primary detection electrode PPO detects the primary vibration and generates a voltage signal whose magnitude corresponds to its amplitude. This voltage signal is fed back to the primary detection unit 210. Based on the voltage signal generated by the primary detection electrode PPO, the primary detection unit 210 outputs an output signal to the primary AC power supply 200. Based on the output signal from the primary detection unit 210, the amplitude and frequency of the primary AC power supply 200 are controlled; specifically, the amplitude and frequency of the AC current Ip are controlled to keep the vibration frequency and amplitude of the oscillator 20 constant.

[0191] The output signal of the secondary detection unit 230 is input to the secondary AC power supply 220. Based on this output signal, the secondary AC power supply 220 supplies AC current to the secondary drive electrode SD to drive the oscillator 20, thereby canceling the secondary vibration generated by the oscillator 20. Additionally, the secondary AC power supply 220 inputs an output signal based on the output current to the arithmetic unit 240.

[0192] The arithmetic unit 240 calculates the angular velocity based on the output signal of the secondary AC power supply 220.

[0193] According to this embodiment, by using the primary detection unit 210 to detect the voltage generated by the primary detection electrode PPO and feeding back the output signal of the primary detection unit 210 to the primary AC power supply 200, the primary vibration generated by the oscillator 20 can be stabilized.

[0194] Furthermore, the voltage generated by the secondary detection electrode SPO is detected by the secondary detection unit 230, and the output of the secondary AC power supply 220 is controlled based on the output signal of the secondary detection unit 230, thereby canceling the secondary vibration generated by the oscillator 20. This stabilizes the vibration state of the oscillator 20. Consequently, the noise component contained in the output signal of the secondary AC power supply 220 is reduced, and the detection accuracy of the angular velocity is improved.

[0195] Furthermore, in the vibration-type gyroscope element 120 of this embodiment, the arrangement and connection relationship of the primary drive electrode PD and the secondary detection electrode SPO are the same as those of the vibration-type gyroscope element 100 shown in the first embodiment. That is, the vibration-type gyroscope element 120 and the angular velocity sensor 1100 of this embodiment can also achieve the same effect as the structure shown in the first embodiment. Specifically, the crosstalk voltage contained in the voltage generated by the secondary detection electrode SPO when the vibration-type gyroscope element 120 is operating can be reduced. In addition, the crosstalk voltage contained in the output signal of the vibration-type gyroscope element 120 can be reduced, thereby improving the detection accuracy of angular velocity.

[0196] Furthermore, in the vibration-type gyroscope element 120 of this embodiment, such as Figure 15 As shown, a secondary drive electrode SD is arranged at a position between the primary drive electrode PD and the secondary detection electrode SPO. This reduces the mutual inductance between the primary drive electrode PD and the secondary detection electrode SPO, thereby reducing the magnitude of the crosstalk voltage generated by the secondary detection electrode SPO.

[0197] It should be noted that the arrangement of the electrodes PD, PPO, SD, and SPO on each support 30 is not particularly limited to the following: Figure 14 , Figure 15 The example shown is illustrated below. For instance, the primary detection electrode PPO can be arranged on the outside, and the primary driving electrode PD on the inside, as not shown. In this way, with the primary driving electrode PPO and the secondary detection electrode SD arranged between the primary driving electrode PD and the secondary detection electrode SPO, the magnitude of the crosstalk voltage generated by the secondary detection electrode SPO can be further reduced.

[0198] It should be noted that by connecting the four secondary detection electrodes SPO in series, the signal-to-noise ratio (S / N ratio) of the output signal of the secondary detection unit 230 can be increased, thereby improving the detection accuracy of the angular velocity calculated by the calculation unit 240, which is the same as the vibration type gyroscope element shown in the first embodiment.

[0199] Furthermore, for the same reason, the four primary detection electrodes PPO are preferably connected in series.

[0200] (Other implementation methods)

[0201] It is also possible to appropriately combine the constituent elements shown in the first embodiment, the second embodiment, and the various modifications to construct new embodiments.

[0202] For example, the primary detection electrode PPO and the secondary drive electrode SD shown in the second embodiment can be applied to the vibration-type gyroscope element 100 shown in variations 1 to 5. In this case, it is self-evident that the primary drive electrode PD and the primary detection electrode PPO are formed to extend side by side with a gap between them in the planes of the support portion 30 and the oscillator 20. Similarly, the secondary drive electrode SD and the secondary detection electrode SD are formed to extend side by side with a gap between them in the planes of the support portion 30 and the oscillator 20.

[0203] It should be noted that in the second embodiment, an example is shown where the primary driving electrode PD and the primary detection electrode PPO are arranged side by side on the front of the oscillator 20 and the support portion 30. However, this is not particularly limiting; for example, they may also be arranged side by side with a gap between them in the thickness direction of the oscillator 20 and the support portion 30. Specifically, one of the primary driving electrode PD and the primary detection electrode PPO may be located on the front of the oscillator 20 and the support portion 30, and the other on the back of the oscillator 20 and the support portion 30. Similarly, the secondary driving electrode SD and the secondary detection electrode SPO may also be arranged side by side with a gap between them in the thickness direction of the oscillator 20 and the support portion 30. That is, one of the secondary driving electrode SD and the secondary detection electrode SPO may be located on the front of the oscillator 20 and the support portion 30, and the other on the back of the oscillator 20 and the support portion 30. Alternatively, these electrodes may be arranged inside the oscillator 20 and the support portion 30.

[0204] It should be noted that the oscillator 20 can be any shape that is excited to undergo primary vibration and whose vibration state changes when angular velocity is generated; it is not particularly limited to a ring shape. For example, it can also be a regular polygonal ring or a disk shape. Alternatively, it can be hemispherical.

[0205] Furthermore, the support portion 30 is not limited to any shape, as long as it can connect the oscillator 20 to the fixing portion 10 without hindering the vibration of the oscillator 20. Figure 1 , Figure 3 The shape shown.

[0206] It should be noted that, alternatively, the multiple secondary detection electrodes SPO can be not connected in series. Instead, the voltages generated by the multiple secondary detection electrodes SPO can be input to the arithmetic unit 240, where addition is performed internally. Similarly, the multiple primary detection electrodes PPO can be not connected in series. Instead, the voltages generated by the multiple primary detection electrodes PPO can be input to the arithmetic unit 240 (not shown), where addition is performed internally and the voltage is then input to the primary AC power supply 200.

[0207] -Industry Applicability-

[0208] The vibration-type gyroscope element disclosed herein can reduce the crosstalk voltage generated by the secondary detection electrode during operation, and is therefore useful in applications of high-precision angular velocity sensors.

[0209] - Symbol Explanation -

[0210] 10. Fixing part

[0211] 20 oscillators

[0212] 30 Support section

[0213] 40a~40p electrodes

[0214] 51 First silicon layer

[0215] 52 Silicon oxide layer

[0216] 53 Second silicon layer

[0217] 54 Silica film

[0218] 60 Magnetic field application section

[0219] 61 Upper yoke

[0220] 62 magnets

[0221] 63 lower yoke

[0222] 100, 110, 120 vibration type gyroscope elements

[0223] 200 primary AC power supply

[0224] 210 Primary Testing Department

[0225] 220 secondary AC power supply

[0226] 230 Secondary Testing Department

[0227] 240 Computing Unit

[0228] 1000 angular velocity sensor

[0229] 1100 angular velocity sensor.

Claims

1. A vibrating gyroscope element, characterized in that: The vibrating gyroscope element includes at least a fixed part, an oscillator, a support part, electrodes, and a magnetic field application part. The support portion connects the oscillator to the fixing portion and supports the oscillator in a manner that allows it to vibrate. The electrodes are formed in the plane of the oscillator. The magnetic field applying part applies a magnetic field to the plurality of electrodes along a direction intersecting the front of the oscillator. When the oscillator has a vibration mode of cosNθ and N is a natural number greater than 2, The electrodes are arranged in 4N directions, and the axes of the electrodes are arranged at equal angular intervals along the outer periphery of the oscillator. The plurality of electrodes include a primary driving electrode and a secondary detection electrode, wherein the primary driving electrode excites primary vibrations of the cosNθ mode on the oscillator, and the secondary detection electrode detects secondary vibrations of the oscillator. When the number of arrangements in which the primary driving electrode is arranged in a position adjacent to the clockwise side of the secondary detection electrode is set to S1, the number of arrangements in which the primary driving electrode is arranged in a position adjacent to the counterclockwise side of the secondary detection electrode is set to S2, and the number of secondary detection electrodes in which the primary driving electrode is not arranged in either the clockwise or counterclockwise side is set to U, the following relationship (1) or (2) is satisfied. U≥1　（1） (S1+S2)-2≥|S1-S2| (2), The plurality of electrodes also include a primary detection electrode and a secondary driving electrode. The primary detection electrode detects the primary vibration. The secondary drive electrode drives the oscillator to counteract the secondary vibration. The primary detection electrode and the primary driving electrode are arranged in the same orientation. The secondary driving electrode and the secondary detection electrode are arranged in the same orientation.

2. The vibration-type gyroscope element according to claim 1, characterized in that: The relationship S1 = S2 is satisfied.

3. An angular velocity sensor, characterized in that: The angular velocity sensor includes at least the vibration-type gyroscope element as described in claim 1, a primary AC power supply, a primary detection unit, a secondary AC power supply, a secondary detection unit, and a computing unit. The primary AC power supply applies an AC current of a specified frequency to the primary driving electrode. The primary detection unit detects the voltage signal generated by the primary detection electrode. The secondary AC power supply applies an alternating current to the secondary drive electrode. The secondary detection unit detects the voltage signal generated by the secondary detection electrode. The arithmetic unit calculates the angular velocity based on the output signal of the secondary AC power supply.

4. The angular velocity sensor according to claim 3, characterized in that: By feeding back the output signal of the primary detection unit to the primary AC power supply, the primary vibration generated by the oscillator is stabilized. The output of the secondary AC power supply is controlled based on the output signal of the secondary detection unit, thereby canceling out the secondary vibration generated by the oscillator. The arithmetic unit calculates the angular velocity based on the output signal of the secondary AC power supply.

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