JP3755524B2 - Angular velocity detector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve detection accuracy in an angular velocity detection device. <P>SOLUTION: Frames 30-1 to 30-4 are provided on a substrate in the state capable of vibrating in the X-axis direction through driving beams 42-1 to 42-4, 43-1 to 43-4, 45-1 to 45-4, 46-1 to 46-4, and a vibrator 20 is provided inside the frames 30-1 to 30-4 in the state capable of vibrating in the X-axis direction and in the Y-axis direction through detection beams 33-1 to 33-4. The vibration in the Y-axis direction of the vibrator 20 is detected in the state where the frames 30-1 to 30-4 and the vibrator 20 are vibrated in the X-axis direction, to thereby detect an angular velocity working around the Z-axis. The driving beams 42-1 to 42-4, 43-1 to 43-4, 45-1 to 45-4, 46-1 to 46-4 are constituted from a pair of driving beams 42-1 to 42-4, 43-1 to 43-4 provided respectively on symmetrical positions with respect to the center position in the X-axis direction of the frames, and a pair of driving beams 45-1 to 45-4, 46-1 to 46-4 provided between the pair of driving beams 42-1 to 42-4, 43-1 to 43-4. <P>COPYRIGHT: (C)2004,JPO

Description

  The present invention relates to an angular velocity detection device that detects an angular velocity of an object using Coriolis force.

  Conventionally, for example, Technical Digest of the 16th Symposium, 1998, pp. 37-40 of the 16th Sensor Symposium published in 1998, JP-A-10-103960, and 1997 Transducer (Trnsducer '97) published by IEEE, as described on pages 1129 to 1132, connected to the substrate via a support member, and orthogonal to each other on the substrate. A vibration unit that can vibrate in a direction, a drive unit that is provided on the substrate and vibrates the vibration unit in the X-axis direction, and a detection unit that is provided on the substrate and detects vibration in the Y-axis direction of the vibration unit. An angular velocity detection device that detects an angular velocity acting around the Z axis perpendicular to the X axis and the Y axis in a state where the vibration unit is vibrated in the X axis direction based on vibration in the Y axis direction of the vibration unit. Well-known It is.

  In the IEEE-issued transducer, the vibrating portion is connected to the substrate via a driving beam as a support member and is capable of vibrating in the X-axis direction on the substrate, and in the frame. And a vibrator that is connected to the frame via a detection beam as a support member and can vibrate on the substrate in the Y-axis direction with respect to the frame. Driving in the X-axis direction causes the vibrator to vibrate in the X-axis direction with respect to the substrate, and detects vibration in the Y-axis direction with respect to the substrate of the vibrator by the detection unit. It is also shown that the force is not transmitted, and the vibrator is easily vibrated in the Y-axis direction by the angular velocity around the Z-axis, thereby improving the detection accuracy of the angular velocity. Japanese Patent Laid-Open No. 10-103960 discloses that a part of the drive signal for vibrating the vibrating portion in the X-axis direction leaks in the Y-axis direction (hereinafter, this leakage vibration is referred to as crosstalk). In order to prevent the noise from appearing as noise, a correction unit that vibrates the vibration unit in the Y-axis direction is provided so that the vibration unit is vibrated in the Y-axis direction by the amount that cancels the crosstalk. ing.

  However, in this type of angular velocity detection device, not only the angular velocity detection error due to the crosstalk, but also the vibration portion (vibrator) due to variations in processing of the vibration portion (vibrator), drive unit, frame, beam, etc. ) Cannot be vibrated stably in the desired direction (in the X-axis direction), or the vibrator can stably vibrate in the desired direction (in the Y-axis direction) in accordance with the Coriolis force. As a result, there is a problem that the accuracy of detecting the angular velocity is deteriorated.

  Further, in the conventional angular velocity detection device of the type in which a rectangular frame is connected to a substrate via a driving beam, and a vibrator is connected to the frame via a detection beam inside the frame, When the board is deformed due to external factors such as temperature change and external force, the frame and the driving beam are also deformed along with the deformation of the board. Therefore, internal stress is generated in the driving beam, and the spring constant of the driving beam is changed. Since the nonlinearity becomes large and the deformation amount of the driving beam is limited, the vibrator cannot be stably vibrated in a desired direction (in the X-axis direction) with high accuracy, and the angular velocity detection accuracy. There is also the problem of worsening. Further, in this type of angular velocity detection device, since only driving beams are provided at both ends of the two opposite sides of the frame, the stress acting on one beam becomes too large, Since the nonlinearity of the spring constant of the driving beam becomes large and the deformation amount of the driving beam is limited, the vibrator is vibrated in a desired direction (in the X-axis direction) with high stability and large amplitude. In other words, the angular velocity detection accuracy deteriorates.

  Further, in the conventional angular velocity detection device, the vibration and crosstalk in the Y-axis direction of the vibrator corresponding to the Coriolis force are also input to the substrate via the frame and the beam, and the reaction to the input vibration. Is input from the substrate to the vibrator via the frame and the beam. The vibration input to the vibrator causes noise with respect to the detected angular velocity. Therefore, if the vibration and crosstalk in the Y-axis direction according to the Coriolis force of the vibrator are increased, the angular velocity detection accuracy is deteriorated. There is also a problem.

  The present invention has been made in order to address the above-described problems, and its object is to reduce the detection error as much as possible by reducing the influence of vibration due to the processing variations, the nonlinearity of the beam, and the Coriolis force of the vibrator. An object of the present invention is to provide an angular velocity detecting device.

In order to achieve the above object, the structural feature of the present invention is that it is divided in the Y-axis direction parallel to the upper surface of the substrate, and is arranged to extend in the X-axis direction parallel to the upper surface of the substrate and orthogonal to the Y-axis direction. A pair of main frames, a pair of sub-frames arranged outside the pair of main frames in the Y-axis direction and extending in parallel with the pair of main frames, respectively, and arranged inside the pair of main frames in the Y-axis direction A first driving beam that extends in the Y-axis direction, connects the substrate and the pair of subframes, and supports the pair of subframes so as to vibrate in the X-axis direction; A second driving beam extending in the axial direction and connecting the pair of sub-frames and the pair of main frames to support the pair of main frames so as to vibrate in the X-axis direction; A detection beam oscillating supporting the vibrator in the X-axis direction and the Y-axis direction respectively connected to the pair of main frames with vibrator while being extended in the X-axis direction, a pair of main frames in the substrate A drive unit for vibrating in the X-axis direction and a detection unit for detecting vibration in the Y-axis direction with respect to the substrate of the vibrator are provided, and the pair of main frames, the pair of subframes, and the vibrator are arranged in the X-axis. in that the angular velocity acting on the Z-axis orthogonal to the X-axis and Y-axis in a state of oscillating in the direction so as to detect based on the vibration of the Y-axis direction in the vibrator.

In this case, for example, a terminal portion extending in the Y-axis direction is provided at each end portion of the pair of main frames, and the driving unit drives the pair of main frames in the X-axis direction at each terminal portion. Can be configured.

According to this, since the pair of frames and the pair of subframes can be supported with respect to the substrate by many first and second driving beams, the stress acting on one first and second driving beams is kept small. And the linearity of the spring constants of the first and second driving beams can be kept good, and the maximum deformation amount of the first and second driving beams can be kept large. Can be vibrated stably and with a large amplitude in the X-axis direction, and the angular velocity detection accuracy can be improved. Further, since the pair of subframes acts as reinforcing members for the first and second drive beams, the displacement of the pair of main frames in the Y-axis direction due to the deformation of the first and second drive beams is suppressed, and the pair of subframes The main frame can be vibrated stably and with a large amplitude in the X-axis direction with high accuracy. The vibrator can also be vibrated with high accuracy in the X-axis direction with high amplitude through the pair of main frames, and the angular velocity detection accuracy can be improved.

Furthermore, the pair of main frames are divided into a plurality of parts in the Y-axis direction without surrounding the entire periphery of the vibrator, and are elastically connected by the detection beam via the vibrator, so that external changes such as temperature changes and external forces can be avoided. Even if the substrate is deformed, such as warping in the Y-axis direction due to a mechanical factor, the deformation is absorbed by the detection beam, and the pair of main frames can be prevented from affecting each other. And each deformation amount of the second driving beam can be kept small. Therefore, the generation of internal stress in the first and second drive beams due to external factors can be suppressed to an extremely low level, and the linearity of the spring constant of the first and second drive beams can be kept good. Since the maximum amount of deformation of the first and second driving beams can be increased, the vibrator can be vibrated stably and with a large amplitude in the X-axis direction. The accuracy of detecting the angular velocity can be improved.

a. DESCRIPTION OF EXEMPLARY EMBODIMENTS First Embodiment Hereinafter, a first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a plan view of an angular velocity detecting element composed of a semiconductor according to the embodiment, and FIG. It is sectional drawing. In FIGS. 1 and 2, the pattern is different between a member having a gap with respect to the upper surface of the substrate 10 and a member having no gap.

  This angular velocity detection element is formed symmetrically with respect to the center lines in the X and Y axes orthogonal to each other in the horizontal plane, and on the substrate 10 formed of silicon in a rectangular shape, The pair of main frames 30-1 and 30-2 and the pair of subframes 30-3 and 30-4 are extended in a horizontal plane separated from the upper surface by a predetermined distance. These vibrators 20 and the respective frames 30-1, 30-2, 30-3, and 30-4 constitute a vibration part that is supported on the substrate 10 so as to vibrate.

  The vibrator 20 vibrates in the Y-axis direction with an amplitude proportional to the magnitude of the angular velocity by the angular velocity around the Z-axis orthogonal to both the X and Y axes in a state of vibrating in the X-axis direction. A square-shaped mass portion 21 having an appropriate mass and having an X-axis and a Y-axis extending in each side, and extending from each diagonal position of the mass portion 21 in the X-axis direction. In addition, it is formed in an approximately H shape comprising four arm portions 22-1 to 22-4. A wide portion such as the mass portion 21 and the arm portions 22-1 to 22-4 are provided with a plurality of rectangular through holes 21a.

  The main frames 30-1 and 30-2 vibrate the vibrator 20 in the X-axis direction. The main frames 30-1 and 30-2 respectively move in the X-axis direction at positions outside the Y-axis direction of the arm portions 22-1 to 22-4 of the vibrator 20. Wide long portions 31-1 and 31-2 that are extended, and wide ends that are shortly extended in the Y-axis direction at both ends of both long portions 31-1 and 31-2, respectively. Each of the portions 32-1 to 32-4 is formed in a substantially I-shape. The subframes 30-3 and 30-4 are also wide and extend in the X-axis direction on the outer sides of the long portions 31-1 and 31-2. The main frames 30-1 and 30-2 and the sub frames 30-3 and 30-4 are also provided with through holes similar to the through holes 21a in the vibrator 20.

  In this case, between each inner end in the Y-axis direction of the end portions 32-1 and 32-3 and each inner end in the Y-axis direction of the end portions 32-2 and 32-4 in the main frames 30-1 and 30-2. Each is provided with a gap. This means that the main frames 30-1 and 30-2 are divided into a plurality of parts in the Y-axis direction without surrounding the entire periphery of the vibrator 20.

  The main frames 30-1 and 30-2 are connected to the vibrator 20 by beams 33-1 to 33-4. The beams 33-1 to 33-4 are also extended in the X-axis direction within a horizontal plane separated from the upper surface of the substrate 10 by a predetermined distance, and one end of each of the arms 22-1 to 22-4 of the vibrator 20 is provided. The other ends are connected to the vicinity of the roots, and the other ends are connected to the end portions 32-1 to 32-4 of the main frames 30-1 and 30-2, respectively. Further, the beams 33-1 to 33-4 are the arm portions 22-1 to 22-4 of the vibrator 20, the long portions 31-1 and 31-2 and the end portion 32 of the main frames 30-1 and 30-2. It is configured to be narrower than the width of −1 to 32-4. Accordingly, vibration in the Y-axis direction is difficult to be transmitted from the main frames 30-1 and 30-2 to the vibrator 20, and vibration in the X-axis direction is efficiently transmitted, and the vibrator 20 is attached to the main frame 30. As compared with the X-axis direction, vibrations in the Y-axis direction are easier with respect to −1 and 30-2. That is, the beams 33-1 to 33-4 support the vibrator 20 so as to be able to vibrate in the Y-axis direction with respect to the substrate 10, the main frames 30-1 and 30-2, and the sub frames 30-3 and 30-4. It has the function to do.

  The main frame 30-1 can vibrate with respect to the substrate 10 via the anchors 41-1, 41-2, the beams 42-1, 42-2, the subframe 30-3, and the beams 43-1, 43-2. It is supported. As shown in FIG. 2A, the anchors 41-1 and 41-2 are fixed to the upper surface of the substrate 10 at each outer position of the long portion 31-1 of the main frame 30-1. Each end of the beams 42-1 and 42-2 is connected to the anchors 41-1 and 41-2, and the beams 42-1 and 42-2 are respectively connected to the anchors 41-1 and 41-2 from the Y-axis. It extends outward in the direction. The ends of the beams 42-1 and 42-2 are connected to the inner end of the subframe 30-3, and the subframe 30-3 extends inward in the Y-axis direction of the frame 30-3. One end of each of the beams 43-1 and 43-2 is connected. The other ends of the beams 43-1 and 43-2 are respectively connected to the outer ends of the long portion 31-1 of the main frame 30-1. The beams 42-1, 42-2, 43-1, and 43-2 are a predetermined distance from the substrate 10 in the same manner as the vibrator 20, the main frames 30-1 and 30-2, and the subframes 30-3 and 30-4. It is provided so as to float upward, and has a narrow width like the beams 33-1 and 33-2.

  The main frame 30-2 can vibrate with respect to the substrate 10 via the anchors 41-3 and 41-4, the beams 42-3 and 42-4, the subframe 30-4, and the beams 43-3 and 43-4. It is supported. These anchors 41-3 and 41-4, beams 42-3 and 42-4, subframe 30-4 and beams 43-3 and 43-4 are anchors 41-1, 41-2, beams 42-1, 42-2, the sub-frame 30-3 and the beams 43-1 and 43-2 are symmetrically configured with respect to the center line in the Y-axis direction and are similarly configured. With these configurations, the main frames 30-1 and 30-2 are supported with respect to the substrate 10 so as to easily vibrate in the X-axis direction and hardly vibrate in the Y-axis direction. In other words, the beams 42-1 to 42-4 and 43-1 to 43-4 are arranged so that the main frames 30-1 and 30-2, the subframes 30-3 and 30-4, and the vibrator 20 are X with respect to the substrate 10. It has a function of supporting the shaft so as to vibrate. Further, the sub frames 30-3 and 30-4 act as reinforcing members, and make it difficult for the beams 42-1 to 42-4 and 43-1 to 43-4 to be deformed in directions other than the X-axis direction. The anchors 41-1 to 41-4, the beams 42-1 to 42-4, 43-1 to 43-4, and 33-1 to 33-4 are connected to the vibrating portion (the vibrator 20 and the frame 30-1). To 30-4) are configured to support the substrate 10 so as to vibrate.

  Further, on the substrate 10, drive electrode portions 51-1 to 51-4 for driving the main frames 30-1 and 30-2 with respect to the substrate 10 in the X-axis direction, and the main frame 30-1, Drive monitor electrode units 52-1 to 52-4 for monitoring the X-axis direction drive of the substrate 2 to 30-2, and a detection electrode unit for detecting the vibration of the vibrator 20 to the substrate 10 in the Y-axis direction. 53-1 to 53-4 are provided.

  The drive electrode portions 51-1 to 51-4 are located at the end portions 32-1 to 32-4 at outer positions in the X-axis direction of the end portions 32-1 to 32-4 of the main frames 30-1 and 30-2. Comb-shaped electrodes 51a1 to 51a4 each having a plurality of electrode fingers extending in the X-axis direction. Each comb-like electrode 51a1 to 51a4 is integrally formed with the pad portions 51b1 to 51b4 connected to the electrodes 51a1 to 51a4 and fixed to the upper surface of the substrate 10 as shown in FIG. In addition, electrode pads 51c1 to 51c4 made of conductive metal (for example, aluminum) are provided on the upper surfaces of the pad portions 51b1 to 51b4, respectively. The terminal portions 32-1 to 32-4 are provided with comb-like electrodes 32a1 to 32a4 made of a plurality of electrode fingers extending outward in the X-axis direction so as to face the comb-like electrodes 51a1 to 51a4, respectively. ing. The comb-shaped electrodes 32a1 to 32a4 are integrally formed with the terminal portions 32-1 to 32-4 and are provided so as to float a predetermined distance from the upper surface of the substrate 10, and the electrode fingers of the electrodes 32a1 to 32a4 are The comb-like electrodes 51a1 to 51a4 invade into the center positions in the width direction of the adjacent electrode fingers and face the adjacent electrode fingers.

  The drive monitor electrode portions 52-1 to 52-4 are located at the end portions 32-1 to 32-2 at the X-axis direction inner positions of the end portions 32-1 to 32-4 of the main frames 30-1 and 30-2. 4 have comb-like electrodes 52a1 to 52a4 each having a plurality of electrode fingers extending in the X-axis direction. As shown in FIGS. 2B and 2C, each of the comb-shaped electrodes 52a1 to 52a4 is integrally formed with the pad portions 52b1 to 52b4 connected to the electrodes 52a1 to 52a4 to form the substrate 10 respectively. Electrode pads 52c1 to 52c4 made of a conductive metal (for example, aluminum) are provided on the upper surfaces of the pad portions 52b1 to 52b4, respectively. The terminal portions 32-1 to 32-4 are provided with comb-like electrodes 32b1 to 32b4 made of a plurality of electrode fingers extending inward in the X-axis direction so as to face the comb-like electrodes 52a1 to 52a4, respectively. ing. The comb-shaped electrodes 32b1 to 32b4 are integrally formed with the terminal portions 32-1 to 32-4 and are provided so as to float a predetermined distance from the upper surface of the substrate 10. Each electrode finger of the electrodes 32b1 to 32b4 is The comb-like electrodes 52a1 to 52a4 invade into the center positions in the width direction of the adjacent electrode fingers and face the adjacent electrode fingers.

  The detection electrode parts 53-1 to 53-4 are respectively provided with comb-like electrodes 53a1 to 53a4 having a plurality of electrode fingers extending on both the inner and outer sides in the X-axis direction at the respective outer positions of the mass part 21. Each comb-like electrode 53a1 to 53a4 is integrally formed with pad portions 53b1 to 53b4 connected to the electrodes 53a1 to 53a4 and fixed to the upper surface of the substrate 10 as shown in FIG. In addition, electrode pads 53c1 to 53c4 made of conductive metal (for example, aluminum) are provided on the upper surfaces of the pad portions 53b1 to 53b4, respectively. The mass portion 21 of the vibrator 20 is provided with comb-like electrodes 21a1 to 21a4 made up of a plurality of electrode fingers extending outward in the X-axis direction so as to face each one of the comb-like electrodes 53a1 to 53a4. It has been. Comb-like electrodes 22a1 to 22a4 made up of a plurality of electrode fingers extending inward in the X-axis direction are also provided at the intermediate portions of the arm portions 22-1 to 22-4 of the vibrator 20 as comb-like electrodes 53a1 to 53a4. Are provided to face each other. The comb-like electrodes 21a1 to 21a4 and 22a1 to 22a4 are formed integrally with the mass portion 21 and the arm portions 22-1 to 22-4, and are provided so as to float by a predetermined distance from the upper surface of the substrate 10. The electrode fingers 21a1 to 21a4 and 22a1 to 22a4 enter between the adjacent electrode fingers of the comb-like electrodes 53a1 to 53a4 and face the adjacent electrode fingers. In this case, the electrode fingers of the comb-like electrodes 21a1 to 21a4, 22a1 to 22a4 are provided so as to be shifted to one side from the center position in the width direction of the adjacent electrode fingers of the comb-like electrodes 53a1 to 53a4.

  Further, on the substrate 10, the vibrator 20 includes beams 33-3 and 33-4, a main frame 30-2, beams 43-3 and 43-4, a subframe 30-4, a beam 42-3, and an anchor 41-. The pad part 20a electrically connected via 3 is provided. The pad portion 20a is formed integrally with the anchor 41-3 and is fixed to the upper surface of the substrate 10. An electrode pad 20b made of conductive metal (for example, aluminum) is provided on the upper surface of the pad portion 20a. ing.

  Next, a method for manufacturing the angular velocity detecting element having the above configuration will be briefly described with reference to FIG. First, an SOI (Silicon-On-Insulator) substrate in which a single crystal silicon layer C is provided on the upper surface of the single crystal silicon layer A via a silicon oxide film B is prepared. Phosphorus, boron, or the like is formed on the single crystal silicon layer C. The resistance of the layer C is reduced by doping impurities. Hereinafter, this layer is referred to as a low resistance layer C. Next, the portion with the pattern shown in FIG. 1 (excluding the through holes 21a of the vibrator 20, the through holes of the main frames 30-1, 30-2 and the sub frames 30-3, 30-4) and various electrodes The finger portion is masked with a resist film, the single crystal silicon layer C is etched by reactive ion etching or the like, and anchors 41-1 to 41-4 and various comb-like electrodes 51a1 to 51a1 are formed on the silicon oxide film B. 51 a 4, 52 a 1 to 52 a 4, 53 a 1 to 53 a 4, and various pad portions 20 a, 51 b 1 to 51 b 4, 52 b 1 to 52 b 4, 53 b 1 to 53 b 4, etc. (portions described as being fixed to the substrate 10 above).

  Next, the silicon oxide film B remaining in the portion other than the formed portion is removed by etching with a hydrofluoric acid aqueous solution or the like, and the vibrator 20, the beams 33-1 to 33-4, and the main frames 30-1 and 30-. 2, subframes 30-3 and 30-4, beams 42-1 to 42-4, 43-1 to 43-2 and comb-shaped electrodes 32a1 to 32a4, 32b1 to 32b4, 21a1 to 21a4, 22a1 to 22a4 (above The portion described as being floated by a predetermined distance from the substrate 10 is formed. And aluminum etc. are vapor-deposited on various pad part 20a, 51b1-51b4, 52b1-52b4, 53b1-53b4, and electrode pad 20b, 51c1-51c4, 52c1-52c4, 53c1-53c4 is formed. Therefore, each of the above-described portions formed on the substrate 10 is composed of the low resistance layer C insulated from the substrate 10, and the vibrator 20, the beams 33-1 to 33-4, the main frame 30-1, 30-2, subframes 30-3 and 30-4, beams 42-1 to 42-4, 43-1 to 43-4, and comb-shaped electrodes 32a1 to 32a4, 32b1 to 32b4, 21a1 to 21a4, 22a1 to 22a4 However, it has a structure in which it floats from the substrate 10 by a predetermined distance and is supported on the substrate 10 by the anchors 41-1 to 41-4 so as to vibrate.

  An electrical circuit device for detecting an angular velocity using the angular velocity detection element configured as described above will be described. FIG. 3 shows the electrical circuit device in a block diagram.

A high frequency oscillator 61 is connected to the electrode pads 53c1 and 53c2 of the detection electrode portions 53-1, 53-2, and the oscillator 61 has a detection signal E having a frequency f ₁ that is extremely higher than the resonance frequency of the vibrator 20. ₁ sin (2πf ₁ t) is supplied to the pads 53c1 and 53c2. This is the high-frequency oscillator 61 is connected to a phase inversion circuit 61a, the circuit 61a will detect a detection signal E ₁ sin the phase inverted of said detection signal _{E 1 sin (2πf 1 t)} (2πf 1 t + π) It supplies to the electrode pads 53c3 and 53c4 of the electrode parts 53-3 and 53-4.

The electrode pads 52c1,52c3 drive monitor electrode portions 52-1 and 52-3 are high-frequency oscillator 62 is connected, the oscillator 62 is very high and the frequency f ₁ than the resonance frequency of the vibrator 20 A monitor signal E ₂ sin (2πf ₂ t) having a different frequency f ₂ is supplied to the pads 52c1 and 52c3. The high-frequency oscillator 62 is connected to a phase inversion circuit 62a, the circuit 62a is driven monitor electrode the inverted monitoring signal _{E 2 sin (2πf 2 t +} π) phase of the monitoring signal E ₂ sin (2πf ₂ t) It supplies to the electrode pads 52c2 and 52c4 of the parts 52-2 and 52-4. As a result, when the vibrations of the vibrator 20 in the X and Y axis directions are expressed by E _0x sin (2πf ₀ t) and E _0y sin (2πf ₀ t), they are output from the electrode pad 20b and are X, The signals representing the vibrations in both Y-axis directions are E ₂ · E _0x · sin (2πf ₀ t) · sin (2πf ₂ t), E ₁ · E _0y · sin (2πf ₀ t) · sin (2πf ₁ t). The frequency f ₀ is a frequency near the resonance frequency of the vibrator 20.

  A drive circuit 70 is connected to the electrode pads 51c1 to 51c4 of the drive electrode portions 51-1 to 51-4. The drive circuit 70 forms a drive signal based on a signal input from the electrode pad 20b through the amplifier 63 and supplies the drive signal to each of the electrode pads 51c1 to 51c4.

The drive circuit 70 includes a demodulation circuit 71, a phase shift circuit 72, and a gain control circuit 73 that are connected in series to the amplifier 63, and a detection circuit 74 that is connected to the demodulation circuit 71 and controls the gain of the gain control circuit 73. It has. Demodulation circuit 71, a signal outputted from the electrode pads 20b by detecting synchronism with the frequency f ₂ (retrieves an amplitude envelope of the frequency 2 [pi] f ₂ of the signal), the signal E representing the vibration components in the X-axis direction of the vibrator 20 _0x sin (2πf ₀ t) is output. The phase shift circuit 72 corrects that the detection signal representing the vibration of the vibrator 20 is delayed by π / 2 (corresponding to 1 / 8πf ₀ seconds) with respect to the signal for driving the vibrator 20. The phase of the input signal is advanced by π / 2 and output. The detection circuit 74 synchronously detects the signal from the demodulation circuit 71 at the frequency f ₀ (takes out the amplitude envelope of the vibration component in the X-axis direction of the vibrator 20), and vibrates the vibration component in the X-axis direction of the vibrator 20. A signal E _0x representing the amplitude of is output. The gain control circuit 73 outputs the output signal from the phase shift circuit 72 so that the amplitude of the input signal of the phase shift circuit 72 and the gain control circuit 73 (the amplitude of the vibration component in the X-axis direction of the vibrator 20) is constant. The gain is controlled and output in accordance with the signal E _0x from the detection circuit 74, that is, the gain is controlled and output so that the amplitude of the output signal of the gain control circuit 73 decreases as the signal from the detection circuit 74 increases. .

The drive circuit 70 also includes adders 75-1 and 75-3 connected to the output of the gain control circuit 73, and an adder 75 connected to the gain control circuit 73 via a phase inverting circuit 73a. -2 and 75-4 are also provided. The phase inversion circuit 73a inverts the phase of the signal from the gain control circuit 73 and outputs it. The adders 75-1 and 75-2 are connected to a variable voltage source circuit 76a that outputs a DC voltage E _T that is variably adjusted, and the adders 75-3 and 75-4 are connected to a fixed DC voltage E. A constant voltage source circuit 76b for outputting _B is connected.

The adder 75-1 adds the signal E _0x 'sin (2πf ₀ t) from the gain control circuit 73 and the DC voltage signal E _T from the variable voltage source circuit 76a, and adds the added voltage E _T + E _0x ' sin. (2πf ₀ t) is supplied to the electrode pad 51c1 of the drive electrode portion 51-1. The adder 75-2 adds the signal E _0x 'sin (2πf ₀ t + π) from the phase inverting circuit 73a and the DC voltage signal E _T from the variable voltage source circuit 76a to add the added voltage E _T + E _0x ' sin. (2πf ₀ t + π) is supplied to the electrode pad 51c2 of the drive electrode portion 51-2. The adder 75-3 adds the signal E _0x 'sin (2πf ₀ t) from the gain control circuit 73 and the DC voltage signal E _B from the constant voltage source circuit 76b, and adds the added voltage E _B + E _0x ' sin. (2πf ₀ t) is supplied to the electrode pad 51c3 of the drive electrode section 51-3. The adder 75-4 adds the signal E _0x 'sin (2πf ₀ t + π) from the phase inverting circuit 73a and the DC voltage signal E _B from the constant voltage source circuit 76b, and adds the added voltage E _B + E _0x ' sin. (2πf ₀ t + π) is supplied to the electrode pad 51c4 of the drive electrode portion 51-4.

The amplifier 63 is connected to an output circuit 80 including a demodulation circuit 81, a detection circuit 82, and an amplifier 83 connected in series. The demodulating circuit 81 synchronously detects the signal output from the electrode pad 20b at the frequency f ₁ (takes out the amplitude envelope of the signal at the frequency f ₁ ), and the signal E representing the vibration component of the vibrator 20 in the Y-axis direction. _0y sin (2πf ₀ t) is output. The detection circuit 82 synchronously detects the signal from the demodulation circuit 81 at the frequency f ₀ (takes out the amplitude envelope of the vibration component of the vibrator 20 in the Y-axis direction), and vibrates the vibration component of the vibrator 20 in the Y-axis direction. A signal E _0y representing the amplitude of is output. The amplifier 83 receives the signal E _0y and outputs a DC signal representing the magnitude of vibration of the vibrator 20 in the Y-axis direction from the output terminal OUT.

In the first embodiment configured as described above, after the angular velocity detecting device is configured by connecting the angular velocity detecting element to the electric circuit device as shown in FIG. 3, the angular velocity around the Z-axis is measured before the device is shipped. In the state of “0”, a signal representing the magnitude of vibration of the vibrator 20 in the Y-axis direction is extracted from the output terminal OUT. In this case, since an angular velocity "0", the output signal is should be "0", by changing the DC voltage signal E _T by adjusting the "0" unless the variable voltage source circuit 76a The output signal is set to “0”.

To explain this point, the drive electrode portions 51-1 and 51-2 have drive voltage signals E _T + E _0x 'sin (2πf ₀ t), E _T + E _0x ' sin (2πf ₀ t + π) = E _T − E _0x 'sin (2πf ₀ t) is applied, and drive voltage signals E _B + E _0x ' sin (2πf ₀ t), E _B + E _0x 'sin (2πf) are applied to the drive electrode portions 51-3 and 51-4. ₀ t + π) = E _B −E _0x 'sin (2πf ₀ t) is applied. If the angular velocity detection element is configured accurately, if set equal to the DC voltage signal E _B from the DC voltage signal E _T and a constant voltage source circuit 76b from the variable voltage source circuit 76a, a main frame 30- 1 and 30-2, an equal force due to electrostatic attraction acts in the X-axis direction. The main frames 30-1 and 30-2 are synchronized in the X-axis direction at the vibration frequency f ₀ and vibrate with the same amplitude. Should do. This vibration is transmitted to the vibrator 20 via the beams 33-1 to 33-4, and the vibrator 20 should vibrate only in the X-axis direction. Therefore, the signal representing the magnitude of vibration in the Y-axis direction of the vibrator 20 taken out from the output terminal OUT should be “0”.

In this case, a signal E ₂ · E _0x · sin (2πf ₀ t) representing a vibration component in the X-axis direction is obtained by the action of the high-frequency oscillator 62, the phase inverting circuit 62a, and the drive monitor electrode units 52-1 to 52-4. Sin (2πf ₂ t) is supplied to the drive circuit 70 via the electrode pad 20b and the amplifier 63. The demodulating circuit 71, the detecting circuit 74, the phase shift circuit 72, and the gain control circuit 73 constituting the drive circuit 70 are input signals E _0x sin (2πf ₀ t) of the phase shift circuit 72 and the gain control circuit 73, that is, electrodes Since the vibration component in the X-axis direction from the pad 20b acts so as to be always constant in time, the vibrator 20 always vibrates with a constant amplitude in the X-axis direction.

On the other hand, main parts 30-1 and 30-2, beams 33-1 to 33-4, drive electrode portions 51-1 to 51-4, and the like are processed due to variations in each part of the angular velocity detection element. If the frames 30-1 and 30-2 are not evenly driven in the X-axis direction, the vibrator 20 will vibrate in the Y-axis direction even if the DC voltage signals E _T and E _B are equal. Here, paying attention to the driving forces F1 and F2 to the main frames 30-1 and 30-2, the driving force F1 is the driving voltage signal E _T + E _0x 'sin (2πf ₀ t), E _T −E _0x. This is based on 'sin (2πf ₀ t), and is expressed by the following formula 1 where K is a proportional constant.

F1 = K. {(E _T + E _0x 'sin (2πf ₀ t)) ² − (E _T −E _0x ' sin (2πf ₀ t)) ² }
= 4 · K · E _T · E _0x 'sin (2πf ₀ t)

The driving force F2 is based on the driving voltage signal E _B + E _0x 'sin (2πf ₀ t), E _B -E _0x ' sin (2πf ₀ t), and is expressed by the following equation (2).

F1 = K. {(E _B + E _0x 'sin (2πf ₀ t)) ² − (E _B −E _0x ' sin (2πf ₀ t)) ² }
= 4 · K · E _B · E _0x 'sin (2πf ₀ t)

These numbers 1, as can be understood from Equation 2, by changing the magnitude of the DC voltage signal E _T output from the variable voltage source circuit 76a, both driving force to the main frame 30-1 and 30-2 The size of can be adjusted. Therefore, the vibration component in the Y-axis direction of the vibrator 20 and the main frames 30-1 and 30-2 can be removed.

  As described above, according to the first embodiment, the drive electrode units 51-1 to 51-4 for driving the vibrator 20 and the main frames 30-1 and 30-2 in the X-axis direction are divided into a plurality of parts. At the same time, the drive voltage signals applied to the drive electrode portions 51-1 to 51-4 are variably adjusted independently, so that the main frames 30-1 and 30-2, the beams 33-1 to 33-4, and Even if there are variations in processing in the drive electrode portions 51-1 to 51-4 and the like, leakage vibration in the Y-axis direction of the vibrator 20 due to variations in the processing can be easily removed.

  Next, the operation of detecting the angular velocity around the Z axis using the angular velocity detection device that has finished the adjustment will be described. First, the angular velocity detection device is fixed to an object whose angular velocity is to be detected, and the electric circuit device is operated as described above. In this state, when an angular velocity acts around the Z axis, the vibrator 20 starts to vibrate in the Y axis direction with an amplitude proportional to the angular velocity due to the Coriolis force.

In this case, the capacitance of the detection electrode portions 53-1 to 53-4 changes according to the vibration due to the vibration of the vibrator 20 in the Y-axis direction. The change in capacitance is caused by detection signals E ₁ sin (2πf ₁ t) and E ₁ sin (2πf ₁ t + π) = − E ₁ sin (2πf ₁ ) output from the high-frequency oscillator 61 and the phase inversion circuit 61a. A signal obtained by modulating the amplitude of tπ), that is, E ₁ · E _0y · sin (2πf ₀ t) · sin (2πf ₁ t) appears on the electrode pad 20b and is output to the output circuit 80 via the amplifier 63. . The output circuit 80 outputs a signal E _0y indicating the magnitude of vibration of the vibrator 20 in the Y-axis direction from the output terminal OUT by the operation of the demodulation circuit 81, the detection circuit 82, and the amplifier 83. Since the magnitude of the vibration in the Y-axis direction is proportional to the angular velocity around the Z-axis, a detection signal indicating the same angular velocity is output from the output terminal OUT.

  As described above, in the angular velocity detecting element according to the first embodiment, the vibrator 20, the main frames 30-1, 30-2, and the sub frames 30-3, 30-4 are the driving beams (support members). The vibrator 20 is supported on the substrate 10 so as to vibrate in the X-axis direction by beams 42-1 to 42-4 and 43-1 to 43-4 extending in the Y-axis direction functioning as The beams 33-1 to 33-4 extending in the X-axis direction functioning as detection beams (support members) are supported on the substrate 10 so as to vibrate in the Y-axis direction. On the substrate 10, the vibrator 20, the main frames 30-1 and 30-2 and the sub-frames 30-3 and 30-4 are independently driven in the X-axis direction by being arranged at different positions in the Y-axis direction. Possible drive electrode portions 51-1 to 51-4 are provided, and each drive force by these drive electrode portions 51-1 to 51-4 is adjusted by the drive circuit 70. Even if there are variations in processing in each part of the detection element, the vibration in the X-axis direction of the vibrator 20, the main frames 30-1, 30-2, and the sub frames 30-3, 30-4 can be accurately and stably performed. The angular velocity around the Z axis is detected with high accuracy.

  Further, as described above, the main frames 30-1 and 30-2 are divided into a plurality of pieces in the Y-axis direction without surrounding the entire periphery of the vibrator 20, and the beams 33-1 to 33-4 are passed through the vibrator 20. Therefore, even if the substrate 10 is deformed such as warping in the Y-axis direction due to external factors such as temperature change and external force, the deformation is absorbed by the beams 33-1 to 33-4. The main frames 30-1 and 30-2 can be prevented from affecting each other, and the deformation amounts of the beams 42-1 to 42-4 and 43-1 to 43-4 can be suppressed to be small. it can. Therefore, the generation of internal stress in the beams 42-1 to 42-4 and 43-1 to 43-4 due to the external factors can be suppressed to be extremely small, and the linearity of the spring constant of the driving beam can be kept good. In addition, since the maximum deformation amount of the beams 42-1 to 42-4 and 43-1 to 43-4 can be increased, the vibrator 20 can be vibrated stably and accurately in the X-axis direction with a large amplitude. Also in this respect, the detection accuracy of the angular velocity around the Z axis can be improved.

b. Second Embodiment Next, an angular velocity detection device according to a second embodiment of the present invention will be described. FIG. 4 is a plan view of the angular velocity detection element according to the second embodiment shown in the same manner as in FIG. .

  This angular velocity detection element is a correction electrode unit 54-for canceling the influence of the oblique vibration (vibration component in the Y-axis direction) of the main frames 30-1 and 30-2 due to driving on the angular velocity detection element of the first embodiment. 1 to 54-4 is provided. Since other parts are the same as those in the first embodiment, the same reference numerals are given and description thereof is omitted.

  The correction electrode portions 54-1 to 54-4 are provided on both the inner and outer sides in the X-axis direction at the inner portions in the Y-axis direction of the end portions 32-1 to 32-4 of the main frames 30-1 and 30-2. And comb-shaped electrodes 54a1 to 54a4 each having a plurality of electrode fingers extending in the X-axis direction. Each of the comb-like electrodes 54a1 to 54a4 is integrally formed with the pad portions 54b1 to 54b4 connected to the electrodes 54a1 to 54a4 and fixed to the upper surface of the substrate 10, and is attached to the upper surface of the pad portions 54b1 to 54b4. Are provided with electrode pads 54c1 to 54c4 made of a conductive metal (for example, aluminum). Comb-like electrodes composed of a plurality of electrode fingers extending inward and outward in the X-axis direction on the inner sides in the Y-axis direction of the end portions 32-1 to 32-4 of the main frames 30-1 and 30-2 32c1 to 32c4 are provided to face the comb-like electrodes 54a1 to 54a4, respectively. The comb-shaped electrodes 32c1 to 32c4 are formed integrally with the main frames 30-1 and 30-2, and are provided so as to float by a predetermined distance from the upper surface of the substrate 10. The electrode fingers of the electrodes 32c1 to 32c4 are The interdigital electrodes 54a1 to 54a4 penetrate between adjacent electrode fingers and face the adjacent electrode fingers.

  Also in this case, the electrode fingers of the comb-shaped electrodes 32c1 to 32c4 are provided to be shifted from the center positions in the width direction of the adjacent electrode fingers of the comb-shaped electrodes 54a1 to 54a4. The displacement direction of each electrode finger of the comb-shaped electrodes 32c1 to 32c4 is the comb-shaped electrodes 21a1 to 21a4 and 22a1 with respect to the electrode fingers of the comb-shaped electrodes 54a1 to 54a4 in the detection electrode units 53-1 to 53-4 described above. This is opposite to the direction of displacement of the electrode fingers of ˜22a4. Accordingly, in this case, the capacitance (capacitance) change of the correction electrode portions 54-1 to 54-4 due to the displacement of the main frames 30-1 and 30-2 in the Y-axis direction is the same as the Y-axis of the vibrator 20 described above. It changes opposite to the capacitance change of the detection electrode portions 53-1 to 53-4 due to the displacement in the direction. That is, when the capacities of the correction electrode portions 54-1 to 54-4 increase (or decrease) with respect to the displacement of the main frames 30-1 and 30-2 and the vibrator 20 in the same direction of the Y axis, the detection electrode portion The capacities of 53-1 to 53-4 decrease (or increase). Note that the capacitance change of the correction electrode portions 54-1 to 54-4 caused by unnecessary vibrations of the main frames 30-1 and 30-2 in the Y-axis direction is caused by unnecessary vibrations of the vibrator 20 in the Y-axis direction. The correction electrode portions 54-1 to 54-4 and the detection electrode portions 53-1 to 53-4 are configured so as to be opposite to and have the same size as the capacitance changes of the detection electrode portions 53-1 to 53-4. It is necessary to keep it.

  Next, the first electric circuit device connected to the angular velocity detecting element will be described. FIG. 5 shows the electric circuit device in a block diagram. In this electric circuit device, the electrode pads 54c1 and 54c2 for the correction electrode portions 54-1 and 54-2 are commonly used with the electrode pads 53c1 and 53c2 for the detection electrode portions 53-1 and 53-2. 61 is connected to the output. Further, the electrode pads 54c3 and 54c4 for the correction electrode portions 54-3 and 54-4 are output to the phase inverting circuit 61a in common with the electrode pads 53c3 and 53c4 for the detection electrode portions 53-3 and 53-4. It is connected. Since the other circuits are the same as those in the first embodiment, the same reference numerals are given and description thereof is omitted.

  Also in the angular velocity detection device according to the second embodiment configured as described above, the angular velocity around the Z-axis is detected as in the case of the first embodiment. 54-4 functions as follows.

  That is, when the main frames 30-1 and 30-2 and the vibrator 20 vibrate in an oblique direction inclined from the X axis with respect to the substrate 10 by driving the drive electrode portions 51-1 to 51-4, the Z axis Even if the rotational angular velocity is “0”, a vibration component in the Y-axis direction appears at the output terminal OUT. However, in this case, the high-frequency signal for detection from the high-frequency oscillator 61 is supplied to the comb-like electrodes 53a1 and 53a2 of the detection electrode portions 53-1 and 53-2 and the correction electrode portions 54-1 and 54-2. Of the high frequency signal from the phase inversion circuit 61a is supplied to the comb electrodes 53a3 and 53a4 of the detection electrode portions 53-3 and 53-4. It is supplied to the comb electrodes 54a3 and 54a4 of the correction electrode portions 54-3 and 54-4. As described above, the capacitances of the correction electrode portions 54-1 to 54-4 with respect to the displacement of the main frames 30-1 and 30-2 and the vibrator 20 in the same direction as the Y axis are the detection electrode portions 53-1. Since the vibrator 20 and the main frames 30-1 and 30-2 simultaneously vibrate in an oblique direction inclined from the X axis, the Y of the vibrator 20 is changed. Correction electrode portions 54-1 to 54-54 brought about by the vibration components in the Y-axis direction of the main frames 30-1, 30-2 from the capacitance changes of the detection electrode portions 53-1 to 53-4 brought about by the vibration components in the axial direction. -4 capacitance change is removed.

  On the other hand, the main frames 30-1 and 30-2 are configured not to vibrate in the Y-axis direction due to the action of the beams 42-1 to 42-4 and 43-1 to 43-4 as support members, and the vibrator 20 is easily vibrated integrally with the main frames 30-1 and 30-2 in the X-axis direction by the action of the beams 33-1 to 33-4 as support members, and the main frame 30-1 in the Y-axis direction. , 30-2. Therefore, for the angular velocity around the Z axis, only the vibrator 20 vibrates in the Y axis direction in proportion to the Coriolis force due to the Coriolis force. As a result, even if the vibrator 20 is driven in a direction tilted from the X axis due to variations in processing of each component on the substrate 10, particularly the main frames 30-1 and 30-2, The influence of the vibration in the inclined direction is removed, and the angular velocity is detected with high accuracy.

  Next, the second electric circuit device connected to the angular velocity detecting element according to the second embodiment will be described. FIG. 6 is a block diagram showing the electric circuit device.

In this electric circuit device, the electrode pads 54c1 and 54c2 for the correction electrode portions 54-1 and 54-2 are connected to the output of the high-frequency oscillator 64. The electrode pads 54c3 and 54c4 for the correction electrode portions 54-3 and 54-4 are connected to the output of the phase inversion circuit 64a that inverts the phase of the output of the high frequency oscillator 64. The high-frequency oscillator 64 and the phase inversion circuit 64a are for detecting the capacitance change of the correction electrode portions 54-1 and 54-2. The oscillator 64 is extremely higher than the resonance frequency of the vibrator 20, and the high-frequency oscillator 61. , 62 outputs a correction electrode signal E ₃ sin (2πf ₃ t) having a frequency f ₃ different from the oscillation frequencies f ₁ and f ₂ .

In this electric circuit device, the demodulator circuit 84, the detector circuit 85, and the amplifier 86 are connected to the output of the amplifier 63 in parallel with the demodulator circuit 81, the detector circuit 82, and the amplifier 83. The demodulation circuit 84 synchronously detects the signal output from the electrode pad 20b at the frequency f ₃ (takes out the amplitude envelope of the signal at the frequency f ₃ ), and in the Y-axis direction of the main frames 30-1 and 30-2. A signal E _3y sin (2πf ₀ t) representing the vibration component is output. The detection circuit 85 synchronously detects the signal from the demodulation circuit 84 at the frequency f ₀ (takes out the amplitude envelope of the vibration component in the Y-axis direction of the main frames 30-1 and 30-2), and the main frame 30- A signal E _3y representing the amplitude of the vibration component of 1, 30-2 in the Y-axis direction is output. Between the output terminal OUT and the amplifier 83 and 86, a subtracter 87 and to and outputting the subtraction output value E _3y amplifier 86 from the output value E _0y of the amplifier 83 is connected.

  In the angular velocity detection device configured as described above, the angular velocity around the Z-axis is detected as in the case of the first embodiment, but this case is also detected by the correction electrode portions 54-1 to 54-4. Using the vibration component in the Y-axis direction of the main frames 30-1 and 30-2, the vibration component in the Y-axis direction of the vibrator 20 by driving is removed.

In other words, when the main frames 30-1 and 30-2 and the vibrator 20 vibrate in an oblique direction inclined from the X axis with respect to the substrate 10 by driving the drive electrode portions 51-1 to 51-4, The amplitude value of the vibration component in the Y-axis direction of the main frames 30-1 and 30-2 in the direction vibration is extracted as an output value E _3y by the action of the demodulation circuit 84, the detection circuit 85 and the amplifier 86. The subtractor 87 subtracts the output value E _3y from the output value E _{0y of the} amplifier 83 _indicating the magnitude of vibration of the vibrator 20 in the Y-axis direction, and outputs the result from the output terminal OUT. On the other hand, the output value E _0y representing the vibration in the Y-axis direction of the vibrator 20 extracted from the amplifier 83 is oblique to the main frames 30-1 and 30-2 in addition to the vibration component due to the angular velocity around the Z-axis. Unnecessary vibration components due to vibration in the direction are also included, and these unnecessary vibration components are removed by subtraction of the subtractor 87.

  Therefore, also in the angular velocity detection device using the second electric circuit device, the vibrator 20 is tilted from the X axis due to processing variations of the components on the substrate 10, particularly the main frames 30-1 and 30-2. Even if driven in the direction, the influence of the vibration in the tilted direction of the vibrator 20 by the drive is removed, and the angular velocity is detected with high accuracy.

  In the first electric circuit device of the angular velocity detection device according to the second embodiment, the correction electrode portions 54-1 to 54-54 caused by unnecessary vibrations in the Y-axis direction of the main frames 30-1 and 30-2. −4 so that the capacitance change of −4 is opposite and equal to the capacitance change of the detection electrode portions 53-1 to 53-4 caused by unnecessary vibration of the vibrator 20 in the Y-axis direction. It is necessary to configure the parts 54-1 to 54-4 and the detection electrode parts 53-1 to 53-4. However, according to the second electric circuit device, by adjusting the gains of the amplifiers 83 and 86, the capacitance changes of the correction electrode portions 54-1 to 54-4 and the detection electrode portions 53-1 to 53-4 are adjusted. Even if the sizes are different, unnecessary vibration components in the Y-axis direction of the vibrator 20 can be removed.

  Further, when the angular velocity detection element is applied to the second electric circuit device, the capacitance change of the correction electrode portions 54-1 to 54-4 is opposite to the capacitance change of the detection electrode portions 53-1 to 53-4. There is no need to make it. Therefore, in this case, the direction in which the electrode fingers of the comb-shaped electrodes 32c1 to 32c4 are shifted with respect to the center positions in the width direction of the adjacent electrode fingers of the comb-shaped electrodes 54a1 to 54a4 and the comb-shaped electrodes 53a1 to 53a4 The direction in which the electrode fingers of the comb-like electrodes 21a1 to 21a4 and 22a1 to 22a4 are shifted with respect to the center position in the width direction of the adjacent electrode fingers may be made to coincide with each other or may be made opposite.

c. Third Embodiment Next, an angular velocity detection device according to a third embodiment of the present invention will be described. FIG. 7 is a plan view of the angular velocity detection element according to the third embodiment shown in the same manner as in FIGS. FIG.

  This angular velocity detection element is different from the angular velocity detection element of the second embodiment in that the support structure for the substrate 10 of the main frames 30-1, 30-2 and the subframes 30-3, 30-4 is different. 20 are provided with adjustment electrode portions 55-1 to 55-4 for adjusting the resonance frequency, and servo electrode portions 56-1 to 56-4 for canceling the vibration of the vibrator 20 in the Y-axis direction. It is different in point. Further, the pad portions 54b1 to 54b4 for the correction electrode portions 54-1 to 54-4 of the angular velocity detection element of the second embodiment are omitted, and the pad portions 53b1 to 53b1 of the detection electrode portions 53-1 to 53-4 are omitted. The correction electrode portions 54-1 to 54-4 are also commonly connected to 53b4. This is because, as in the case of the first electric circuit device (FIG. 5) of the second embodiment, the pad portions 53b1 to 53b4 of the detection electrode portions 53-1 to 53-4 and the correction electrode portions 54-1 to 54-1. This means that the pad portions 54b1 to 54b4 for 54-4 are equivalent in operation to the case where they are connected outside the substrate 10. The other parts are the same as those in the second embodiment, so the same reference numerals are given and the description thereof is omitted.

  First, the support structure for the substrate 10 of the main frames 30-1, 30-2 and the sub frames 30-3, 30-4 will be described. A set of support members consisting of the anchor 41-1 and the beams 42-1 and 43-1 and a set of support members consisting of the anchor 41-2 and the beams 42-2 and 43-2 as in the second embodiment. Between the anchor 44-1 and the beams 45-1, 46-1 and a pair of support members composed of the anchor 44-2 and the beams 45-2, 46-2, respectively. Is provided.

  The beams 45-1 and 45-2 extend in the Y-axis direction, and their inner ends are connected to the anchors 44-1 and 44-2, respectively, and their outer ends are connected to the subframe 30-3. Each is connected to the inner end. The beams 46-1 and 46-2 are also extended in the Y-axis direction, and their respective inner ends are connected to the outer ends of the elongated portion 31-1 of the main frame 30-1, respectively. Are respectively connected to the inner ends of the subframes 30-3. Further, the beams 45-1, 45-2, 46-1, and 46-2 are configured to have a narrow width and are predetermined from the substrate 10 in the same manner as the beams 42-1, 42-2, 43-1, and 43-2. It floats upward by a distance.

  In this case, the beam 42-1 and the beam 42-2 are respectively provided symmetrically with respect to the X-axis direction center positions of the frame 30-3 and the main frame 30-1 at both ends of the subframe 30-3. The beams 43-1, 45-1, 46-1 and the beams 43-2, 45-2, 46-2 are also symmetrical with respect to the X-axis direction center positions of the subframe 30-3 and the main frame 30-1. Is provided. All of these beams 42-1, 42-2, 43-1, 43-2, 45-1, 45-2, 46-1, 46-2 are structurally identical in length, width, etc. It is comprised so that it may have the same spring constant. It is preferable to arrange all the beams 42-1, 42-2, 43-1, 43-2, 45-1, 45-2, 46-1, 46-2 at substantially equal intervals in the X-axis direction. .

  Further, all the beams 42-1, 42-2, 43-1, 43-2, 45-1, 45-2, 46-1, 46-2 have the same spring constant and the main frame 30-1 and the sub frame. In order to vibrate the frame 30-3 accurately in the X-axis direction, the structure of the connecting portion is devised. This structure will be described with reference to FIG. 8 taking the beams 45-1 and 46-1 as an example. In order to match the structure of the connecting portion between the beam 45-1 and the anchor 44-1 and the connecting portion between the beam 46-1 and the long portion 31-1 of the main frame 30-1, the anchor 44-1 is a base. 10, and a connecting portion 44 b 1 equal to the width in the X-axis direction of the fixing portion 44 a 1 provided floating from the upper surface of the substrate 10. On the long portion 31-1 side, a connection portion 31 a 1 equal to the width in the X-axis direction of the anchor 44-1 is formed so as to float from the upper surface of the substrate 10. Both the connecting portions 44b1 and 31a1 are provided with through holes 44b11 and 31a11 having the same shape, and the numbers of the through holes 44b11 and 31a11 in the X-axis direction are also set equal. For the other anchors 41-1, 41-2, 44-2 and beams 42-1, 42-2, 43-1, 43-2, 45-2, 46-2, the anchor 44-1 and the beam 45 are also described. -1, 46-1.

  Further, the anchors 41-1, 41-2, 44-1, 44-2 are also symmetrically arranged on the main frame 30-2 and subframe 30-4 side with respect to the center position of the angular velocity detection element in the Y-axis direction. And anchors 41-3, 41-4, 44 similar to the support members made of the beams 42-1, 42-2, 43-1, 43-2, 45-1, 45-2, 46-1, 46-2. −3, 44-4 and beams 42-3, 42-4, 43-3, 43-4, 45-3, 45-4, 46-3, 46-4 are provided.

  As described above, in the third embodiment, in order to vibrate the vibrator 20 and the main frames 30-1 and 30-2 in the X-axis direction, many driving beams 42-1 to 42-4 and 43- are used. 1 to 43-4, 45-1 to 45-4, and 46-1 to 46-4 are provided, so that the vibrator 20 and the main frames 30-1 and 30-2 are also combined into one beam. The acting stress can be kept small. Therefore, the linearity of the spring constants of the beams 42-1 to 42-4, 43-1 to 43-4, 45-1 to 45-4, 46-1 to 46-4 can be kept good, and Since the maximum deformation amount can be kept large, the vibrator 20 can be vibrated stably and with a large amplitude in the X-axis direction and the angular velocity detection accuracy can be improved. In addition, in this 3rd Embodiment, although the number of sets of each support member which consists of the beam and anchor which supports the main frame 30-1 and the main frame 30-2 was each 4, the number of sets of each of these support members is It may be 3 sets or 5 sets or more.

  In the third embodiment, the connection structures of the beams 42-1 to 42-4, 43-1 to 43-4, 45-1 to 45-4, and 46-1 to 46-4 are substantially the same. Therefore, even when the vibrator 20 and the main frames 30-1 and 30-2 are vibrated, the stress acting on each beam can be made uniform. As a result, the linearity of the spring constants of the beams 42-1 to 42-4, 43-1 to 43-4, 45-1 to 45-4, 46-1 to 46-4 are kept good, and their maximum A large amount of deformation can be maintained, and accurate and stable vibration in the X-axis direction of the vibrator 20 and the main frames 30-1 and 30-2 can be ensured. improves. Further, the sub frames 30-3 and 30-4 are beams 42-1 to 42-4, 43-1 to 43-4, and 45-1 with respect to displacements other than the X-axis direction of the main frames 30-1 and 30-2. Since it acts as a reinforcing member for .about.45-4, 46-1 to 46-4, accurate and stable vibration in the X-axis direction of the vibrator 20 and the main frames 30-1, 30-2 is ensured, and angular velocity is detected. Accuracy is improved.

  Next, the adjustment electrode portions 55-1 to 55-4 and the servo electrode portions 56-1 to 56-4 will be described. The adjustment electrode portions 55-1 to 55-4 are provided on the outer sides of the mass portion 21 of the vibrator 20 in the X-axis direction and in the center portion of the substrate 10 in the Y-axis direction, and extend in the X-axis direction. A pair of electrode fingers 55a1 to 55a4 is provided. The electrode fingers 55a1 and 55a3 are integrally formed with the pad portions 56b1 connected in common to the electrode fingers 55a1 and 55a3, respectively, and are fixed to the upper surface of the substrate 10. The electrode fingers 55a2 and 55a4 are integrally formed with the pad portion 55b2 commonly connected to the electrode fingers 55a2 and 55a4, and are fixed to the upper surface of the substrate 10. Electrode pads 55c1 and 55c2 made of conductive metal (for example, aluminum) are provided on the upper surfaces of the pad portions 55b1 and 55b2, respectively.

  Each pair of electrode fingers 55a1 to 55a4 is provided with a pair of electrode fingers 23a1 to 23a4 that vibrate integrally with the vibrator 20 and extend in the X-axis direction so as to face each other in the Y-axis direction. The electrode fingers 23a1 to 23a4 are respectively integrally formed on the inner ends in the Y-axis direction of the T-shaped portions 23-1 to 23-4 protruding in the X-axis direction from both sides of the mass portion 21 of the vibrator 20 in the X-axis direction. Has been. The T-shaped portions 23-1 to 23-4 and the electrode fingers 23 a 1 to 23 a 4 are formed integrally with the vibrator 20 and are provided so as to float a predetermined distance from the upper surface of the substrate 10.

  The servo electrode portions 56-1 to 56-4 are provided on the inner side in the Y-axis direction of the detection electrode portions 53-1 to 53-4, respectively, and each pair of electrode fingers 56a1 to 56a4 extending in the X-axis direction is provided. Each has. Each pair of electrode fingers 56a1 to 56a4 is integrally formed with the pad portions 56b1 to 56b4 connected to the electrode fingers 56a1 to 56a4 and fixed to the upper surface of the substrate 10, and the upper surfaces of the pad portions 56b1 to 56b4. Are provided with electrode pads 56c1 to 56c4 made of a conductive metal (for example, aluminum).

  Each of the pair of electrode fingers 56a1 to 56a4 has a pair of electrode fingers 23b1 to 23b4 integrally formed on the outer ends in the Y axis direction of the T-shaped portions 23-1 to 23-4, respectively. It is provided opposite to. The electrode fingers 23b1 to 23b4 are also formed integrally with the vibrator 20 and provided so as to float from the upper surface of the substrate 10 by a predetermined distance.

  Next, the first electric circuit device connected to the angular velocity detecting element according to the third embodiment will be described. FIG. 9 is a block diagram showing the electric circuit device. In this electric circuit device, a common electrode pad 53c1 for the detection electrode unit 53-1 and the correction electrode unit 54-1, and a common electrode pad 53c2 for the detection electrode unit 53-2 and the correction electrode unit 54-2. Is connected to the high-frequency oscillator 61. The common electrode pad 53c3 for the detection electrode unit 53-3 and the correction electrode unit 54-3 and the common electrode pad 53c4 for the detection electrode unit 53-4 and the correction electrode unit 54-4 have the above phase. An inverting circuit 61a is connected.

  A DC variable voltage source 65a is connected to the common electrode pad 55c1 for the adjustment electrode portions 55-1 and 55-3, and the common electrode pad 55c2 for the adjustment electrode portions 55-2 and 55-4. Is connected to a DC variable voltage source 65b. These DC variable voltage sources 65a and 65b may be composed of a plurality of voltage sources, but a single voltage source may be used in common.

  A servo control circuit 90 is connected to the electrode pads 56c1 to 56c4 of the servo electrode portions 56-1 to 56-4. The servo control circuit 90 is for suppressing the vibration of the vibrator 20 in the Y-axis direction, and includes a demodulation circuit 91, a servo amplifier 92, and a phase inversion circuit 93. The demodulating circuit 91 is the same as the demodulating circuit 92 of the second embodiment, extracts a signal representing the vibration of the vibrator 20 in the Y-axis direction, and outputs the signal as an AC servo control signal. The servo amplifier 92 amplifies the AC servo control signal with a predetermined gain to cancel the vibration in the Y axis direction of the vibrator 20 (vibration in the Y axis direction of the vibrator 20 due to the angular velocity around the Z axis). The AC servo control signal subjected to the gain control is supplied to the electrode pads 56c3 and 56c4 of the servo electrode portions 56-3 and 56-4. The phase inversion circuit 93 inverts the phase of the AC servo control signal whose gain is controlled, and applies the inverted phase control signal to the electrode pads 56c1 and 56c2 of the servo electrode portions 56-1 and 56-2. Supply.

  The output circuit 80 is connected to the detection circuit 82a and the DC amplifier 83. The detection circuit 82a receives an AC servo control signal from the servo amplifier 92, and also receives a signal representing vibration in the X-axis direction of the vibrator 20 driven by the phase-shift circuit 72, and the AC servo control signal is input to the X-axis direction. And a DC signal representing the magnitude of vibration of the vibrator 20 in the Y-axis direction, that is, the angular velocity around the Z-axis, is output. Here, the output signal of the phase shift circuit 72 is used because the signal is synchronized with the phase of the Coriolis force caused by the angular velocity around the Z axis of the vibrator 20. This is because it is synchronized with the angular velocity around the Z axis. Since the other circuits are the same as those of the first electric circuit device of the second embodiment, the same reference numerals are assigned to the circuits and the description thereof is omitted.

  In the angular velocity detection device according to the third embodiment configured as described above, when the voltages of the DC variable voltage sources 65a and 65b are changed, the magnitude of the electrostatic attractive force by the adjustment electrode portions 55-1 to 55-4 changes. Then, the amount of displacement of the vibrator 20 with respect to the force in the Y-axis direction, that is, the spring constant of the detection beams 33-1 to 33-4 is changed. As a result, the resonance frequency of the vibrator 20 in the Y-axis direction is adjusted as appropriate.

  Further, since the servo control circuit 90 supplies an AC servo control signal to the servo electrode portions 56-1 to 56-4, the servo electrode portions 56-1 to 56-4 are caused to vibrate in the Y axis direction of the vibrator 20, that is, the Z axis. The vibration of the vibrator 20 in the Y-axis direction due to the angular velocity around is suppressed. Ideally, the amplitude of vibration of the vibrator 20 in the Y-axis direction is controlled to “0”. At this time, the servo amplifier 92 outputs a signal for canceling the vibration of the vibrator 20 in the Y-axis direction, that is, a signal indicating the magnitude of the vibration of the vibrator 20 in the Y-axis direction by the angular velocity around the Z-axis in amplitude. Therefore, the detection circuit 82a forms a DC signal representing the magnitude of the angular velocity and outputs it through the amplifier 83. Therefore, actually, a signal representing the magnitude of the angular velocity around the Z axis is extracted even though the vibrator 20 does not vibrate in the Y axis direction.

  As a result, according to the third embodiment, the vibration in the Y-axis direction of the vibrator 20 due to the angular velocity about the Z-axis is not re-input to the vibrator 20 via the substrate 10, and noise accompanying this re-input Can be suppressed, and the angular velocity detection accuracy can be improved.

  Such servo control will be briefly described with reference to a block diagram showing the principle of servo control in FIG. In the figure, Fc represents the Coriolis force in the Y-axis direction caused by the angular velocity around the Z axis, Fs represents the servo force, Rate represents the angular velocity, and N represents the electrical noise of the electric circuit input unit. Represents an amount. Q represents the resonance Q of the vibrator 20, A represents the gain of the servo amplifier 92, and b represents the feedback amount. As can be seen from this block diagram, the angular velocity Rate is expressed by the following equation (3).

    Rate = (N / Q + Fc) / (1 / Q · A + b) Equation 3

  In the equation (3), if the gain A can be set to a large value (for example, a value large enough to be considered to be substantially infinite), the equation (3) is transformed into the following equation (4).

    Rate = Fc / b + N / Q · b Equation 4

In Equation 4, the first term Fc / b represents the angular velocity detection sensitivity, and the second term N / Qb represents the noise component. Here, assuming an angular velocity detection device (without the feedback loop in FIG. 10) that does not perform servo control as described above, the angular velocity Rate is expressed as in the following equation (5).

    Rate = Fc · Q · A + N · A ... Formula 5

In Equation 5, the first term Fc · Q · A represents the angular velocity detection sensitivity, and the second term N · A represents the noise component. By comparing these numbers 4 and 5, when the servo control is not performed, the detection sensitivity of the angular velocity depends on the resonance Q of the vibrator 20, and when the servo control is performed by increasing the gain A to some extent. It can be understood that the detection sensitivity of the angular velocity does not depend on the resonance Q of the vibrator 20. Therefore, according to the third embodiment in which the vibration of the vibrator 20 in the Y-axis direction is servo-controlled, the detection sensitivity of the angular velocity does not depend on the resonance Q of the vibrator 20, and the detection sensitivity can be stabilized. it can.

  Next, a second electric circuit device connected to the angular velocity detection element according to the third embodiment will be described. Before describing the second electric circuit device, the problem of the angular velocity detection device using the first electric circuit device will be described. In this type of servo control, it is necessary to perform servo control near the resonance frequency (several to several tens of kHz) of the vibrator 20. On the other hand, in this type of angular velocity detection element, as shown in FIG. 11B, a large phase shift occurs in the frequency axis due to a mechanical phase delay. If the gain of the servo loop is set large due to this phase shift, oscillation due to servo control occurs in a frequency range where the phase shift is large. Therefore, as shown in FIG. 11 (A), it is necessary to realize stable servo control by suppressing the gain of the servo loop to some extent. This means that the gain A in Equation 3 must be suppressed to a certain small value, and as a result, the angular velocity detection sensitivity as described in Equation 4 depends on the resonance Q of the vibrator 20. Therefore, the detection sensitivity cannot be sufficiently stabilized.

  The second electric circuit device has been considered for such a problem, and the electric circuit device will be described with reference to the block diagram of FIG. Since the second electric circuit device is different from the first electric circuit device only in the output circuit 80 and the servo control circuit 90, only the two circuits 80 and 90 will be described.

  The servo control circuit 90 includes an amplitude control circuit 94a, a detection circuit 95a, a servo amplifier 96a, and a multiplication circuit 97a, and a first servo control circuit for suppressing vibration in the Y-axis direction of the vibrator 20 according to the angular velocity; It comprises an amplitude control circuit 94b, a detection circuit 95b, a servo amplifier 96b, and a multiplication circuit 97b, and a second servo control circuit for suppressing leakage vibration in the Y-axis direction due to driving of the vibrator 20.

  The amplitude control circuit 94a controls the amplitude of a signal synchronized with the Coriolis force acting on the vibrator 20 that is an output of the phase shift circuit 72 to a predetermined reference value, so that the Y axis according to the angular velocity of the vibrator 20 is controlled. A first reference signal having a constant amplitude synchronized with the directional vibration is formed. The detection circuit 95a outputs a signal (vibration) that is output from the demodulation circuit 91 and that represents vibration in the Y-axis direction of the vibrator 20 in synchronization with the Coriolis force that is output from the phase shift circuit 72 and acts on the vibrator 20. The first DC servo control signal proportional to the magnitude of the vibration in the Y-axis direction due to the angular velocity of the vibrator 20 is formed by synchronous detection with a signal synchronized with the vibration in the Y-axis direction due to the angular velocity of the child 20. The servo amplifier 96a amplifies and outputs the first DC servo control signal with a predetermined gain. The multiplication circuit 97a multiplies the first reference signal by the gain-adjusted first DC servo control signal to control the amplitude of the first reference signal in accordance with the first DC servo-control signal adjusted to the same gain. The controlled first reference signal having the same amplitude is output as a control signal for suppressing vibration in the Y-axis direction due to the angular velocity of the vibrator 20.

  The amplitude control circuit 94b is an output of the demodulation circuit 71 and is a signal synchronized with leakage vibration in the Y-axis direction due to driving of the vibrator 20 (with a phase of 90 degrees with respect to vibration in the Y-axis direction due to the angular velocity of the vibrator 20). By controlling the amplitude of the delayed signal) to a predetermined reference value, a second reference signal having a constant amplitude synchronized with the leakage vibration in the Y-axis direction by driving the vibrator 20 is formed. The detection circuit 95b synchronizes the output of the demodulation circuit 91 and representing the vibration in the Y-axis direction of the vibrator 20 with the output of the demodulation circuit 71 and the leakage vibration in the Y-axis direction driven by the vibrator 20. The second DC servo control signal proportional to the magnitude of the leakage vibration due to the driving of the vibrator 20 is formed by synchronous detection using the signal. The servo amplifier 96b amplifies and outputs the second DC servo control signal with a predetermined gain. The multiplication circuit 97b multiplies the second reference signal by the gain-adjusted second DC servo control signal to control the amplitude of the second reference signal according to the gain-adjusted second DC servo control signal. Then, the controlled second reference signal having the same amplitude is output as a control signal for suppressing leakage vibration in the Y-axis direction due to driving of the vibrator 20.

  The outputs of the multiplying circuits 97a and 97b are connected to an adding circuit 98, and the adding circuit 98 adds and synthesizes the outputs of both multiplying circuits 97a and 97b to form electrode pads 56c3 of the servo electrode units 56-3 and 56-4. 56c4. Similarly to the first electric circuit device, the phase inverting circuit 93 inverts the phase of the combined signal from the adder circuit 98 and outputs the inverted combined signal having the same phase inverted to the servo electrode units 56-1 and 56-2. To the electrode pads 56c1 and 56c2.

  The output circuit 80 includes an amplifier 83 similar to that of the first electric circuit device. The amplifier 83 amplifies the output of the servo amplifier 96a and outputs it.

  In the second electric circuit device configured as described above, the first servo control circuit suppresses the vibration of the vibrator 20 in the Y-axis direction according to the angular velocity. Therefore, the vibration of the vibrator 20 in the Y-axis direction due to the angular velocity. Is prevented from being generated due to the reverse input to the vibrator 20 through the substrate 10. Further, since the second servo control circuit suppresses leakage vibration in the Y-axis direction due to driving of the vibrator 20, occurrence of leakage vibration in the Y-axis direction due to the driving is also prevented. On the other hand, the servo amplifier 96a outputs a DC signal proportional to the magnitude of the vibration of the vibrator 20 in the Y-axis direction due to the angular velocity, so that the amplifier 83 can obtain a DC signal representing the angular velocity.

  According to the second electric circuit device, the detection circuits 95a and 95b are provided in front of the servo amplifiers 96a and 96b, respectively, so that the servo control signal is converted into a direct current. Therefore, the servo control is performed in the resonance frequency band of the sensor. Since it becomes unnecessary, the problem of the phase shift described above is eliminated, and the servo loop gain described above can be set large. This means that the gain A in Equation 3 can be set to substantially infinite. As a result, the angular velocity detection sensitivity described in Equation 4 does not depend on the resonance Q of the vibrator 20, The detection sensitivity can be stabilized. Further, even if a phase shift occurs in the detection signal by the amplifier 63 and the demodulation circuit 91, the servo control gain only changes, and the angular velocity detection sensitivity and offset are not affected at all.

d. Abnormality determination in the third embodiment In the third embodiment, the vibration of the vibrator 20 in the Y-axis direction is controlled by servo, so that the vibration is suppressed. The signal representing the vibration of the vibrator 20 in the Y-axis direction is extremely small. Accordingly, whether the signal representing the vibration in the Y-axis direction of the vibrator 20 is “0” due to an abnormality such as a break in the servo control circuit 90, or the vibration in the Y-axis direction of the vibrator 20 is suppressed. Therefore, it may be difficult to determine whether the signal representing the vibration in the Y-axis direction is substantially “0”, and there may be a delay in determining the abnormality. The disconnection abnormality is a circuit constituting a low-pass filter provided in the output unit of the detection circuit 82a, the output unit of the amplifier 83, the servo amplifiers 96a and 96b, a high-pass filter provided in the amplifier 63, the demodulation circuit 91, and the like. It often occurs when a terminal of a component (for example, a capacitor, a resistor) is opened.

  The abnormality determination device will be described. FIG. 13 is a block diagram illustrating a first abnormality determination device example. In this first abnormality determination device example, a low-pass filter 101 including an operational amplifier OP1, resistors R1 and R2, a capacitor C1, and a DC power source DC1 is provided in a path of a detection signal representing vibration in the Y-axis direction of the vibrator 20. is doing. A dummy signal generation circuit 102 is connected to the upstream side of this signal path, that is, the input side of the low-pass filter 101 via a resistor R3. The dummy signal generation circuit 102 outputs a signal having a frequency higher than the cut-off frequency of the low-pass filter 101 and not used for the detection signal and not included in the detection signal as a dummy signal. Superimpose via.

  A window comparator 103, which is composed of comparators COMP1 and COMP2, resistors R4, R5 and R6, and an OR circuit OR1, is connected to the downstream of the detection signal path, that is, the output of the low-pass filter 101. In this case, the detection signal is set so as to fall between the first and second reference voltages Vref1 and Vref2 determined by the resistors R4, R5 and R6, and the dummy signal is the first and second reference voltages Vref1 and Vref2. Large amplitude exceeding the range is set.

  The operation of this first abnormality determination device example will be described. If no disconnection abnormality has occurred in the circuit components such as the capacitor C1 and the low-pass filter 101 is operating normally, it is generated from the dummy signal generation circuit 102. Since the dummy signal does not pass through the low-pass filter 101, the window comparator 103 outputs a low level signal representing normality from the OR circuit OR1 without responding to the detection signal. On the other hand, when a disconnection abnormality occurs in a circuit component such as the capacitor C1 and the low-pass filter 101 does not operate normally, the dummy signal passes through the low-pass filter 101. In this case, the window comparator 103 outputs a high level signal representing an abnormality from the OR circuit OR1 in response to the dummy signal. As a result, the window comparator 103 can detect an abnormality in the signal path including the low-pass filter 101 without delay based on whether or not the dummy signal passes, and a fail processing circuit (not shown) connected to the window comparator 103 can detect the signal path. It can deal with abnormalities without delay.

  FIG. 14 is a block diagram showing a second abnormality determination device example. In this device example, operational amplifiers OP2 and OP3 and a resistor R7 are provided in the path of a detection signal representing the vibration of the vibrator 20 in the Y-axis direction. , R8, R9, a capacitor C2, and a high-pass filter 104 including a DC power source DC2. A dummy signal generation circuit 102 is connected to the upstream side of the signal path, that is, the input side of the high-pass filter 104, via the resistor R3, as in the first abnormality determination device example. In this case, the dummy signal generation circuit 102 outputs, as a dummy signal, a signal having a frequency that is higher than the cutoff frequency of the high-pass filter 104 and is not used for the detection signal and is not included in the detection signal. Is superimposed via a resistor R3.

  A detection circuit 105 and a window comparator 103 similar to the first abnormality determination device example are connected to the downstream of the detection signal path, that is, the output of the high-pass filter 104. These detection circuit 105 and window comparator 103 constitute an abnormality determination circuit. A dummy signal is also supplied to the detection circuit 105. The circuit 105 synchronously detects the output of the high-pass filter 104 with the dummy signal, converts the dummy signal into a DC signal representing the amplitude, and outputs the DC signal to the window comparator 103. To do. In this case, the amplitude of the dummy signal is set to fall between the first and second reference voltages Vref1 and Vref2 set in the resistors R4, R5, and R6.

  The operation of the second abnormality determination device example will be described. If the disconnection abnormality does not occur in the circuit components such as the capacitor C2 and the high-pass filter 104 is operating normally, it is output from the dummy signal generation circuit 102. The dummy signal passes through the high pass filter 104. Since the detection circuit 105 synchronously detects the dummy signal and outputs a DC voltage signal, the window comparator 103 outputs a low level signal indicating normality without responding to the DC voltage signal. On the other hand, if a disconnection abnormality occurs in a circuit component such as the capacitor C2, the dummy signal does not pass through the high-pass filter 104. Therefore, the window comparator 103 responds to the “0” level signal output from the detection circuit 105, and the OR circuit A high level signal indicating abnormality is output from OR1. As a result, the window comparator 103 can detect an abnormality in the signal path including the high-pass filter 104 without delay based on whether or not the dummy signal passes, and a fail processing circuit (not shown) connected to the window comparator 103 can detect the signal path. It can deal with abnormalities without delay.

  FIG. 15 is a block diagram showing a third abnormality determination device example. In the third abnormality determination device example, a frequency detection circuit 106 is used instead of the detection circuit 105 and the window comparator 103 of the second abnormality determination device example. By detecting the frequency of the dummy signal, the frequency detection circuit 106 outputs a high level signal when the dummy signal arrives, and outputs a low level signal otherwise. Also in this case, the dummy signal is a signal having a frequency higher than the cut-off frequency of the high-pass filter 104 and not used for the detection signal and not included in the detection signal.

  Also in the third abnormality determination device example configured as described above, if the disconnection abnormality does not occur in the circuit component such as the capacitor C2 and the high-pass filter 104 is operating normally, the dummy signal generation circuit 102 outputs it. The dummy signal passes through the high pass filter 104. The frequency detection circuit 106 outputs a high level signal indicating normality in response to the arrival of the dummy signal. On the other hand, when a disconnection abnormality occurs in a circuit component such as the capacitor C2, since the dummy signal does not pass through the high-pass filter 104, the frequency detection circuit 106 outputs a low level signal indicating the abnormality. Also by this, the frequency detection circuit 106 can detect the abnormality of the signal path including the high-pass filter 104 without delay depending on whether or not the dummy signal passes, and the fail processing circuit (not shown) connected to the frequency detection circuit 106 can It is possible to cope with signal path abnormalities without delay.

  Therefore, if the first to third abnormality determination devices are used, the vibration of the vibrator 20 in the Y-axis direction is suppressed by servo control, and the amplitude of the signal representing the vibration of the vibrator 20 in the Y-axis direction is “0”. Even if it is extremely small, an abnormality due to the disconnection of the route can be detected without delay depending on the presence or absence of the dummy signal.

e. Other Modifications In the first to third embodiments, the vibrator 20 is vibrated in the X-axis direction via the main frames 30-1 and 30-2. A pair of drive electrode portions 51-1 and 51-2 arranged and a pair of drive electrode portions 51-3 and 51-4 arranged on the same straight line in the X-axis direction are provided at different positions in the Y-axis direction. However, the other one or more pairs of drive electrode portions arranged on the same straight line in the X-axis direction are arranged at different positions in the Y-axis direction from the drive electrode portions 51-1 to 51-4. You may make it do. In this case as well, driving signals having opposite phases are supplied to all pairs of driving electrode portions, and the driving force by the driving signals for at least the pair of driving electrode portions can be changed.

  In the first to third embodiments, the variable voltage source circuit 76a is connected to the adders 75-1 and 75-2, and the constant voltage source circuit 76a is connected to the adders 75-3 and 75-4. Connected. However, the variable voltage source circuit 76a and the constant voltage source circuit 76b generate a voltage applied to the drive electrode portions 51-1 and 51-2 and a voltage applied to the drive electrode portions 51-3 and 51-4. As long as it can be relatively adjusted, a constant voltage source circuit is connected to the adders 75-1 and 75-2, and a variable voltage source is connected to the adders 75-3 and 75-4. A circuit may be connected, or both voltage source circuits 76a and 76b may be made variable.

  In the first to third embodiments, the adders 75-1 to 75-4 superimpose the alternating current signals from the gain control circuit 73 and the phase inverting circuit 73a on the direct current signals by the adders 75-1 to 75-4. Although the drive signal for 51-4 is used, the AC signal from the gain control circuit 73 and the phase inversion circuit 73a may be used as the drive signal for the drive electrode portions 51-1 to 51-4. In this case, in order to make it possible to relatively change the driving force by the driving electrode units 51-1 and 51-2 and the driving force by the driving electrode units 51-3 and 51-4, the driving electrode units 51-1 and 51-5. It is preferable that the amplitude value of at least one of the drive signal including the AC signal for -2 and the drive signal including the AC signal for the drive electrode portions 51-3 and 51-4 can be changed.

It is a top view of the angular velocity detection element concerning a 1st embodiment of the present invention. (A)-(D) are sectional drawings of each part of FIG. It is a block diagram of an electric circuit device for detecting angular velocity using the angular velocity detecting element according to the first embodiment. It is a top view of the angular velocity detection element concerning a 2nd embodiment of the present invention. It is a block diagram of the 1st electric circuit apparatus for detecting angular velocity using the angular velocity detection element concerning the 2nd embodiment. It is a block diagram of the 2nd electric circuit device for detecting angular velocity using the angular velocity detection element concerning the 2nd embodiment. It is a top view of the angular velocity detection element concerning a 3rd embodiment of the present invention. FIG. 8 is an enlarged partial view showing in detail the support structure of the main frame of FIG. 7. It is a block diagram of the 1st electric circuit device for detecting angular velocity using the angular velocity detection element concerning the 3rd embodiment. It is a block diagram which shows the principle figure of the servo control of the said 3rd Embodiment. (A) is a graph showing the frequency characteristic of the servo loop gain in the servo control, and (B) is a graph showing the frequency characteristic of the servo loop phase in the servo control. It is a block diagram of the 2nd electric circuit device for detecting angular velocity using the angular velocity detection element concerning the 3rd embodiment. It is a block diagram which shows the 1st abnormality determination circuit apparatus suitable for being incorporated in the servo control circuit of the said 3rd Embodiment. It is a block diagram which shows the 2nd abnormality determination circuit apparatus suitable for being incorporated in the servo control circuit of the said 3rd Embodiment. It is a block diagram which shows the 3rd abnormality determination circuit apparatus suitable for being incorporated in the servo control circuit of the said 3rd Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Board | substrate, 20 ... Vibrator, 30-1, 30-2 ... Main frame, 30-3, 30-4 ... Sub frame, 33-1 to 33-4 ... Beam (detection beam), 41-1 41-4, 44-1 to 44-4 ... Anchor, 42-1 to 42-4, 43-1 to 43-4, 45-1 to 45-4, 46-1 to 46-4 ... Beam (for driving) Beams), 51-1 to 51-4... Drive electrode section (drive section), 52-1 to 52-4 drive monitor electrode section (drive monitor section), 53-1 to 53-4 ... detection electrode section (detection) Part), 54-1 to 54-4 ... correction electrode part (correction part), 55-1 to 55-4 ... adjustment electrode part (adjustment part), 56-1 to 56-4 ... servo electrode part (servo part) , 61, 62, 64 ... high frequency oscillator, 70 ... drive circuit, 71, 81, 84, 91 ... demodulation circuit, 74, 82, 82a, 85, 95a, 95b Detection circuit, 75-1 to 75-4 ... adder, 76a ... variable voltage source circuit, 76b ... constant voltage source circuit, 80 ... output circuit, 90 ... servo control circuit, 92, 96a, 96b ... servo amplifier, 94a, 94b, amplitude control circuit, 97a, 97b, multiplication circuit, 101, low-pass filter, 102, dummy signal generation circuit, 103, window comparator, 104, high-pass filter, 105, detection circuit, 106, frequency detection circuit.

Claims (2)

A pair of main frames that are divided in the Y-axis direction parallel to the upper surface of the substrate and arranged to extend in the X-axis direction parallel to the upper surface of the substrate and perpendicular to the Y-axis direction;
A pair of sub-frames that are respectively arranged on the outer side in the Y-axis direction of the pair of main frames and are arranged to extend in parallel with the pair of main frames;
A vibrator disposed inside the pair of main frames in the Y-axis direction;
A first driving beam extending in the Y-axis direction and connecting the substrate and the pair of subframes to support the pair of subframes so as to vibrate in the X-axis direction;
A second driving beam extending in the Y-axis direction and connecting the pair of sub-frames and the pair of main frames to support the pair of main frames so as to vibrate in the X-axis direction;
A detection beam that extends in the X-axis direction and connects the pair of main frames and the vibrator to support the vibrator so as to vibrate in the X-axis direction and the Y-axis direction;
A drive unit for vibrating the pair of main frames in the X-axis direction with respect to the substrate;
A detection unit for detecting vibration of the vibrator with respect to the substrate in the Y-axis direction,
Based on the vibration of the vibrator in the Y-axis direction, the angular velocity acting around the Z-axis orthogonal to the X-axis and the Y-axis in a state where the pair of main frames, the pair of subframes, and the vibrator are vibrated in the X-axis direction. angular velocity detection equipment to detect Te. In the angular velocity detection device according to claim 1,
Each end of the pair of main frames is provided with a terminal portion extending in the Y-axis direction,
The drive unit is an angular velocity detection device that drives the pair of main frames in the X-axis direction at the end portions.

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