Physical quantity detection device

Abstract

To provide a physical quantity detection device or the like capable of achieving improvement of detection sensitivity and individual measurement of detection arms.SOLUTION: The physical quantity detection device 1 includes a physical quantity detection element 10 and a circuit device 20. The physical quantity detection device 10 includes a detection arm EL1A having detection electrodes EL1B and AS1, and a detection arm EL2A having detection electrodes EL2B and AS2. The circuit device 20 includes terminals T1, T2, T3, and T4 coupled to the detection electrodes EL1A, EL1B, EL2A, and EL2B, and an amplifier circuit 120. The amplifier circuit 120 includes a difference amplifier circuit 128, a switch T1 provided between the node NI1 and an input-node SW1A of the difference amplifier circuit 128, a switch T2 provided between the node NI2 and an input-node SW1B of the difference amplifier circuit 128, a switch T3 provided between the node NI2 and the input-node SW2A, and a switch provided between the node and the input-node. T4 NI1 SW2B.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a physical quantity detection device and the like. [Background technology]

[0002] Patent Document 1 discloses a physical quantity detection device in which one of the positive and negative electrodes of the detection arm is not grounded, and detection signals from both the positive and negative electrodes are input to a detection circuit, thereby improving detection sensitivity. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-184124 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the physical quantity detection device of Patent Document 1, the first detection electrode of the first detection arm and the fourth detection electrode of the second detection arm are electrically connected to input the detection signal from the first detection electrode of the first detection arm and the detection signal from the fourth detection electrode of the second detection arm to the first input node of the amplifier circuit. Furthermore, the second detection electrode of the first detection arm and the third detection electrode of the second detection arm are electrically connected to input the detection signal from the second detection electrode of the first detection arm and the detection signal from the third detection electrode of the second detection arm to the second input node of the amplifier circuit. Therefore, it is not possible to determine whether the unwanted signal originates from the first detection arm or the second detection arm, and therefore it is not possible to measure the vibration characteristics of the first detection arm and the second detection arm individually. This makes it difficult to achieve appropriate balance tuning, making it difficult to improve the performance of the physical quantity detection device. [Means for solving the problem]

[0005] One aspect of the present disclosure includes a physical quantity detection element having a plurality of detection arms, a plurality of drive arms, and a base portion; and a circuit device that detects a physical quantity based on a plurality of detection signals from the plurality of detection arms of the physical quantity detection element, wherein the plurality of detection arms of the physical quantity detection element include a first detection arm having a first detection electrode and a second detection electrode and extending from the base portion, and a second detection arm having a third detection electrode and a fourth detection electrode and extending from the base portion in an opposite direction to the first detection arm, and the circuit device includes a first terminal connected to the first detection electrode, a second terminal connected to the second detection electrode, and The physical quantity detection device includes a third terminal connected to a third detection electrode, a fourth terminal connected to the fourth detection electrode, and an amplifier circuit, wherein the amplifier circuit includes a differential amplifier circuit, a first switch provided between the first terminal and a first input node of the differential amplifier circuit, a second switch provided between the second terminal and a second input node of the differential amplifier circuit, a third switch provided between the third terminal and the second input node of the differential amplifier circuit, and a fourth switch provided between the fourth terminal and the first input node of the differential amplifier circuit. [Brief explanation of the drawings]

[0006] [Figure 1] 1 shows an example of the configuration of a physical quantity detection device according to an embodiment of the present invention. [Figure 2] FIG. 3 is an explanatory diagram of the operation of the physical quantity detection element. [Figure 3] 10 shows a detailed configuration example of a circuit device. [Figure 4] FIG. 4 is a signal waveform diagram illustrating the operation of the amplifier circuit. [Figure 5] FIG. [Figure 6] FIG. 10 is an explanatory diagram of a second comparative example. [Figure 7] 1. First configuration example of an amplifier circuit. [Figure 8] FIG. 10 is a diagram showing switch connections in the first configuration example when inspecting the first detection arm. [Figure 9] FIG. 10 is a diagram showing switch connections in the first configuration example when inspecting the second detection arm. [Figure 10] FIG. 2 is an explanatory diagram of the operation of the first configuration example. [Figure 11] 2. Second configuration example of an amplifier circuit. [Figure 12] FIG. 10 is a diagram showing switch connections in the second configuration example when inspecting the first detection arm. [Figure 13] FIG. 10 is a diagram showing switch connections in the second configuration example when inspecting the second detection arm. [Figure 14] FIG. 10 is an explanatory diagram of the operation of the second configuration example. [Figure 15] Third example of amplifier circuit configuration. [Figure 16] FIG. 10 is a diagram showing switch connections in the third configuration example when inspecting the first detection arm. [Figure 17] FIG. 10 is a diagram showing switch connections in the third configuration example when inspecting the second detection arm. [Figure 18] FIG. 10 is an explanatory diagram of the operation of the third configuration example. DETAILED DESCRIPTION OF THE INVENTION

[0007] The present embodiment will be described below. Note that the present embodiment described below does not unduly limit the content of the claims. Furthermore, not all of the configurations described in the present embodiment are necessarily essential components.

[0008] 1. Physical quantity detection device FIG. 1 is a diagram illustrating an example of the configuration of a physical quantity detection device 1 according to this embodiment. As shown in FIG. 1, the physical quantity detection device 1 according to this embodiment includes a physical quantity detection element 10 and a circuit device 20. The physical quantity detection element 10 includes multiple detection arms, multiple drive arms, and a base. In FIG. 1, the physical quantity detection element 10 includes detection arms AS1 and AS2 as the multiple detection arms. The circuit device 20 detects a physical quantity based on multiple detection signals from the multiple detection arms of the physical quantity detection element 10. The physical quantity detection device 1 is not limited to the configuration shown in FIG. 1 , and various modifications are possible, such as omitting some of the components or adding other components. For example, the physical quantity detection device 1 may have a support substrate that supports the physical quantity detection element 10. The support substrate includes a frame, an element mounting portion, and multiple beams. The element mounting portion is provided inside the frame, and the physical quantity detection element 10 is mounted on the support substrate. The beams support the element mounting portion inside the frame. Terminals of the physical quantity detection element 10 and terminals of the circuit device 20 are electrically connected via the support substrate. The physical quantity detection device 1 may also include a package that houses the physical quantity detection element 10 and the circuit device 20. The package may include a base having a recess that opens upward, and a lid joined to the top surface of the base so as to form a space for housing the physical quantity detection device 1 and the circuit device 20 between the base and the lid.

[0009] The physical quantity detection element 10 is an element for detecting a physical quantity and can be referred to as, for example, a physical quantity transducer or a vibration element. The physical quantity detection element 10 has, for example, a vibrating element, and the physical quantity is detected using the vibration of this vibrating element. For example, if the physical quantity detection element 10 is a gyro sensor element, angular velocity is detected as the physical quantity. Examples of gyro sensor elements include sensor elements having a piezoelectric vibrating element formed from a thin plate of a piezoelectric material such as quartz. Specifically, the gyro sensor element is a sensor element having a vibrating element such as a double T-shaped, tuning fork-shaped, or H-shaped vibrating element formed from a quartz substrate such as a Z-cut. Alternatively, a MEMS (Micro Electro Mechanical Systems) sensor element may be used as the gyro sensor element. Furthermore, the physical quantity detected by the physical quantity detection element 10 may be a physical quantity other than angular velocity, such as angular acceleration, angle, acceleration, velocity, movement distance, or pressure.

[0010] The circuit device 20 is, for example, an integrated circuit device called an IC (Integrated Circuit). For example, the circuit device 20 is an IC manufactured by a semiconductor process, and is a semiconductor chip in which circuit elements are formed on a semiconductor substrate. The circuit device 20 includes terminals T1, T2, T3, and T4 and an amplifier circuit 120.

[0011] Terminals T1, T2, T3, and T4 are the first terminal, second terminal, third terminal, and fourth terminal, respectively. These terminals T1, T2, T3, and T4 are, for example, pads of the circuit device 20. For example, in the pad region, a metal layer is exposed from a passivation film, which is an insulating layer, and the exposed metal layer forms the pad, which is the terminal of the circuit device 20.

[0012] The amplifier circuit 120 includes switches SW1A, SW1B, SW2A, and SW2B and a differential amplifier circuit 128. The switches SW1A, SW1B, SW2A, and SW2B are a first switch, a second switch, a third switch, and a fourth switch, respectively. For example, the switches SW1A, SW1B, SW2A, and SW2B can be realized by transistors, and more specifically, can be realized by N-type or P-type MOS transistors. The amplifier circuit 120 will be described in detail later.

[0013] Next, detailed examples of the physical quantity detection element 10 and the circuit device 20 will be described. Fig. 2 is a diagram illustrating an example of the operation of a detailed example of the physical quantity detection element 10. Note that the following mainly describes an example in which the physical quantity detection element 10 is a gyro sensor element, specifically a double-T shaped gyro sensor element. However, as described above, the physical quantity detection element 10 may be a gyro sensor element other than a double-T shaped gyro sensor element, or a physical quantity detection element other than a gyro sensor element.

[0014] For example, if the Z axis is the thickness direction of the physical quantity detection element 10, the physical quantity detection element 10, which is a gyro sensor element, detects an angular velocity ω around the Z axis. The X axis and the Y axis are coordinate axes that are orthogonal to the Z axis, and the X axis and the Y axis are orthogonal to each other. As shown in FIG. 2, the physical quantity detection device 1 includes the physical quantity detection element 10 and a circuit device 20. The circuit device 20 includes a drive circuit 100, a detection circuit 110, and a processing circuit 150. Note that modifications such as omitting some of these components or adding other components are possible.

[0015] Physical quantity detection element 10 has drive arms 18P, 18Q, 18R, and 18S, detection arms 19P and 19Q, a base 21, and connecting arms 22P and 22Q. Detection arms 19P and 19Q extend in the +Y-axis direction and the -Y-axis direction from rectangular base 21. Connecting arms 22P and 22Q extend in the +X-axis direction and the -X-axis direction from base 21. Drive arms 18P and 18Q extend from the tip of connecting arm 22P in the +Y-axis direction and the -Y-axis direction, and drive arms 18R and 18S extend from the tip of connecting arm 22Q in the +Y-axis direction and the -Y-axis direction.

[0016] The physical quantity detection element 10 also has weights 27P, 27Q, 27R, 27S, 28P, and 28Q. These weights are also called hammerheads. Weights 27P and 27Q are provided at the tips of drive arms 18P and 18Q, respectively, and weights 27R and 27S are provided at the tips of drive arms 18R and 18S, respectively. Weights 28P and 28Q are provided at the tips of detection arms 19P and 19Q, respectively. Weights 27P, 27Q, 27R, and 27S provided on drive arms 18P, 18Q, 18R, and 18S are balance adjustment units used to adjust the balance of vibration of the physical quantity detection element 10. For example, during the manufacture of the physical quantity detection device 1, the balance of vibration of the physical quantity detection element 10 is adjusted by performing a trimming process in which the metal of weights 27P, 27Q, 27R, and 27S is removed using a laser.

[0017] The vibrating element of the physical quantity detection element 10 can be formed from a piezoelectric material such as quartz, lithium tantalate, or lithium niobate. Among these, it is preferable to use quartz as the constituent material of the vibrating element. The X-axis, Y-axis, and Z-axis are also called the electrical axis, mechanical axis, and optical axis of the quartz substrate, respectively. The quartz substrate is formed from a plate-shaped Z-cut quartz plate having a thickness in the Z-axis direction.

[0018] Drive electrodes 13 are formed on the upper and lower surfaces of the drive arms 18P and 18Q, and drive electrodes 14 are formed on the right and left sides of the drive arms 18P and 18Q. Drive electrodes 14 are formed on the upper and lower surfaces of the drive arms 18R and 18S, and drive electrodes 13 are formed on the right and left sides of the drive arms 18R and 18S. A drive signal DS from the drive circuit 100 is supplied to the drive electrode 13, and a feedback signal DG from the drive electrode 14 is input to the drive circuit 100. For example, the drive signal DS is output from the drive circuit 100 via terminal T5 of the circuit device 20, and the feedback signal DG is input to the drive circuit 100 via terminal T6 of the circuit device 20.

[0019] Detection electrodes 15A are formed on the upper and lower surfaces of detection arm 19P, and detection electrodes 15B are formed on the right and left sides of detection arm 19P. Detection electrodes 16A are formed on the upper and lower surfaces of detection arm 19Q, and detection electrodes 16B are formed on the right and left sides of detection arm 19Q. Detection electrodes 15A, 15B, 16A, and 16B are the first detection electrode, second detection electrode, third detection electrode, and fourth detection electrode, respectively.

[0020] Detection signals S1A, S1B, S2A, and S2B from detection electrodes 15A, 15B, 16A, and 16B are input to detection circuit 110. Specifically, detection circuit 110 includes an amplifier circuit 120. For example, amplifier circuit 120 is implemented by a charge amplifier that performs charge-to-voltage conversion (Q / V conversion). A first detection signal S1A from detection electrodes 15A formed on the upper and lower surfaces of detection arm 19P is input to amplifier circuit 120 via a first terminal T1. A second detection signal S1B from detection electrodes 15B formed on the right and left surfaces of detection arm 19P is input to amplifier circuit 120 via a second terminal T2. A third detection signal S2A from detection electrodes 16A formed on the upper and lower surfaces of detection arm 19Q is input to amplifier circuit 120 via a third terminal T3. Furthermore, a fourth detection signal S2B from the detection electrodes 16B formed on the right and left sides of the detection arm 19Q is input to the amplifier circuit 120 via the fourth terminal T4. For example, S1A and S2B are in-phase detection signals, as described below. Furthermore, S2A and S1B are in-phase detection signals that are, for example, 180 degrees out of phase with S1A and S2B, and have opposite polarities. This configuration makes it possible to realize double-wiring, which essentially doubles the area of ​​the detection electrodes, as described below.

[0021] Grooves (not shown) are provided on the top and bottom surfaces of the drive arms 18P, 18Q, 18R, and 18S and the detection arms 19P and 19Q to improve the electric field effect between the electrodes. The provision of the grooves makes it possible to generate a relatively large amount of charge with a relatively small amount of distortion.

[0022] Drive terminals 23 and 24 and detection terminals 25A, 25B, 26A, and 26B are provided on base 21. A drive signal DS from drive circuit 100 is input to drive terminal 23, and a feedback signal DG to drive circuit 100 is output from drive terminal 24. Detection signals S1A and S1B are output from detection terminals 25A and 25B of detection arm 19P, and detection signals S2A and S2B are output from detection terminals 26A and 26B of detection arm 19Q.

[0023] The drive circuit 100 included in the circuit device 20 is a circuit that drives the physical quantity detection element 10. The drive circuit 100 outputs a drive signal DS to the physical quantity detection element 10, thereby driving the vibrating arms of the physical quantity detection element 10 to vibrate. The drive signal DS is, for example, a rectangular wave signal, but may also be a sine wave signal.

[0024] The detection circuit 110 detects a physical quantity based on the detection signals S1A, S1B, S2A, and S2B from the physical quantity detection element 10. In FIG. 2, angular velocity is detected as the physical quantity. The detection signals S1A, S1B, S2A, and S2B are detection signals of physical quantities with, for example, the drive frequency of the drive signal DS as the carrier frequency. The detection circuit 110 detects the physical quantity (angular velocity) in the detection signals S1A, S1B, S2A, and S2B by, for example, synchronously detecting the signals based on the detection signals S1A, S1B, S2A, and S2B using a synchronization signal, and outputs the detection data.

[0025] The processing circuit 150 is a circuit that performs processing such as digital signal processing on the detection data from the detection circuit 110. The processing circuit 150 performs digital signal processing, including digital filter processing, on the detection data from the detection circuit 110. The detection data after digital filter processing by the processing circuit 150 is then output as, for example, a final detection value of a physical quantity. Note that the signal processing performed by the processing circuit 150 is not limited to digital filter processing, and various other signal processing such as temperature compensation processing and various correction processing can be performed.

[0026] Next, detailed operation of the physical quantity detection element 10 when it is a gyro sensor element will be described. When a drive signal DS is applied to the drive electrode 13 by the drive circuit 100, the drive arms 18P, 18Q, 18R, and 18S undergo flexural vibration as indicated by arrow C1 in FIG. 2 due to the inverse piezoelectric effect. For example, the vibration modes indicated by the solid arrows and the dotted arrows are repeated at a predetermined frequency. That is, the tips of the drive arms 18P and 18R repeatedly approach and separate from each other, and the tips of the drive arms 18Q and 18S also undergo flexural vibration in which they repeatedly approach and separate from each other. At this time, the drive arms 18P and 18Q and the drive arms 18R and 18S vibrate symmetrically with respect to the X-axis passing through the center of gravity of the base 21, so the base 21, the connecting arms 22P and 22Q, and the detection arms 19P and 19Q hardly vibrate.

[0027] In this state, when an angular velocity about the Z-axis is applied to physical quantity detection element 10, Coriolis force causes drive arms 18P, 18Q, 18R, and 18S to vibrate as indicated by arrow C2. That is, a Coriolis force in the direction of arrow C2, which is perpendicular to the direction of arrow C1 and the Z-axis, acts on drive arms 18P, 18Q, 18R, and 18S, generating a vibration component in the direction of arrow C2. This vibration of arrow C2 is transmitted to base 21 via connecting arms 22P and 22Q, causing detection arms 19P and 19Q to flexurally vibrate in the direction of arrow C3. Charge signals generated by the piezoelectric effect due to the flexural vibration of detection arms 19P and 19Q are input to detection circuit 110 as detection signals S1A, S1B, S2A, and S2B, allowing angular velocity about the Z-axis to be detected.

[0028] For example, if the angular velocity of the physical quantity detection element 10 around the Z axis is ω, the mass is m, and the vibration velocity is v, the Coriolis force is expressed as Fc=2m·v·ω. Therefore, the detection circuit 110 can obtain the angular velocity ω around the Z axis by detecting a desired signal that is a signal corresponding to the Coriolis force.

[0029] FIG. 3 shows a detailed configuration example of the circuit device 20. Note that the circuit device 20 is not limited to the configuration of FIG. 3, and various modifications are possible, such as omitting some of the components or adding other components. Furthermore, the connection in this embodiment is an electrical connection. An electrical connection is a connection that allows electrical signals to be transmitted, and is a connection that allows information to be transmitted by electrical signals. The electrical connection may be a connection via a passive element or the like.

[0030] Physical quantity detection element 10, which is a sensor element, has drive vibrating bar 11, detection vibrating bar 12P, 12Q, drive electrodes 13, 14, and detection electrodes 15A, 15B, 16A, 16B. Drive vibrating bar 11 corresponds to drive arms 18P, 18Q, 18R, 18S in FIG. 2. Detecting vibrating bar 12P corresponds to detection arm 19P in FIG. 2, and detecting vibrating bar 12Q corresponds to detection arm 19Q. Vibrating bars 11, 12P, 12Q are piezoelectric vibrating bars formed from thin plates of a piezoelectric material such as quartz.

[0031] A drive signal DS from the drive circuit 100 is supplied to the drive electrode 13, causing the drive vibrating bar 11 to vibrate. A feedback signal DG generated by the vibration of the vibrating bar 11 is input from the drive electrode 14 to the drive circuit 100. The vibration of the drive vibrating bar 11 also causes the detection vibrating bars 12P and 12Q to vibrate. Charges generated in the detection electrodes 15A and 15B due to the vibration of the vibrating bar 12P are input to terminals T1 and T2 of the circuit device 20 as detection signals S1A and S1B, respectively. Charges generated in the detection electrodes 16A and 16B due to the vibration of the vibrating bar 12Q are input to terminals T3 and T4 of the circuit device 20 as detection signals S2A and S2B, respectively. The circuit device 20 detects physical quantities such as angular velocity based on these detection signals S1A, S1B, S2A, and S2B.

[0032] The driver circuit 100 includes an amplifier circuit 102, a gain control circuit 104, a driver signal output circuit 106, and a synchronization signal output circuit .

[0033] The amplifier circuit 102 amplifies the feedback signal DG from the physical quantity detection element 10. For example, the amplifier circuit 102, which is an I / V conversion circuit, converts the current feedback signal DG from the physical quantity detection element 10 into a voltage signal DV and outputs it.

[0034] The gain control circuit 104 outputs a control voltage VC to the drive signal output circuit 106 to control the amplitude of the drive signal DS. The gain control circuit 104, which is, for example, an AGC circuit, automatically adjusts the gain so that the amplitude of the feedback signal DG from the physical quantity detection element 10 remains constant, in order to maintain constant sensor sensitivity. The gain control circuit 104 includes a full-wave rectifier circuit that performs full-wave rectification of the AC signal DV output by the amplifier circuit 102, and an integration circuit that integrates the signal from the full-wave rectifier circuit. The gain control circuit 104 then outputs the control voltage VC obtained by the integration process to the drive signal output circuit 106.

[0035] The drive signal output circuit 106 outputs a drive signal DS based on the signal DV amplified by the amplifier circuit 102. The drive signal output circuit 106 outputs, for example, a rectangular wave drive signal DS such that the control voltage VC from the gain control circuit 104 becomes a high-level voltage that is a voltage on the high potential side. Note that variations are also possible, such as the drive signal output circuit 106 outputting a sine wave drive signal DS.

[0036] The synchronization signal output circuit 108 outputs a synchronization signal SYC. The synchronization signal SYC is a signal generated based on the drive signal DS. Specifically, the synchronization signal SYC is a signal corresponding to the drive signal DS, and is, for example, a clock signal with the same frequency as the drive signal DS.

[0037] The detection circuit 110 includes an amplifier circuit 120, a synchronous detection circuit 130, a filter circuit 132, and an A / D conversion circuit 134. The amplifier circuit 120 includes switches SW1A, SW1B, SW2A, and SW2B, a differential amplifier circuit 128, and an AC amplifier circuit 129. Note that the configurations of the detection circuit 110 and the amplifier circuit 120 are not limited to these. For example, as will be described later, various modifications are possible, such as providing other circuits such as amplifier circuits between the differential amplifier circuit 128 and the switches SW1A, SW1B, SW2A, and SW2B, or between the switches SW1A, SW1B, SW2A, and SW2B and the terminals T1, T2, T3, and T4, or omitting the configuration of the AC amplifier circuit 129.

[0038] The switch SW1A is provided between the terminal T1 and an input node NI1 of the differential amplifier circuit 128, and the switch SW1B is provided between the terminal T2 and an input node NI2 of the differential amplifier circuit 128. The switch SW2A is provided between the terminal T3 and an input node NI2 of the differential amplifier circuit 128, and the switch SW2B is provided between the terminal T4 and an input node NI1 of the differential amplifier circuit 128. The input node NI1 is a first input node, for example, a node of the inverting input terminal of the differential amplifier circuit 128. The input node NI2 is a second input node, for example, a node of the non-inverting input terminal of the differential amplifier circuit 128.

[0039] With this configuration, the detection signal S1A input via terminal T1 and the detection signal S2B input via terminal T4 are input to an input node NI1 of the differential amplifier circuit 128 via switches SW1A and SW2B, respectively. For example, a first sum signal of the detection signals S1A and S2B is input to the input node NI1 of the differential amplifier circuit 128. Furthermore, the detection signal S2A input via terminal T3 and the detection signal S1B input via terminal T2 are input to an input node NI2 of the differential amplifier circuit 128 via switches SW2A and SW1B, respectively. For example, a second sum signal of the detection signals S2A and S1B is input to the input node NI2 of the differential amplifier circuit 128. The differential amplifier circuit 128 then performs differential amplification of the first sum signal and the second sum signal. As will be described later, the first sum signal and the second sum signal are signals whose phases differ by, for example, 180 degrees from each other. Therefore, by differentially amplifying the first sum signal and the second sum signal, the physical quantity signal included in the detection signal is amplified. Here, the differential amplifier circuit 128 is, for example, a continuous-type charge-to-voltage conversion circuit (Q / V conversion circuit) having a feedback resistor, and converts the detection signal, which is a charge signal, into a voltage signal. The AC amplifier circuit 129 then amplifies the output signal QDF of the differential amplifier circuit 128 and outputs it as the output signal AQA of the amplifier circuit 120. The AC amplifier circuit 129 performs, for example, signal gain adjustment.

[0040] The synchronous detection circuit 130 performs synchronous detection on the output signal AQA of the amplifier circuit 120 based on the synchronization signal SYC. This makes it possible to extract the physical quantity signal, which is the desired signal included in the output signal AQA, and detect the physical quantity.

[0041] The filter circuit 132 performs filtering such as low-pass filtering on the output signal of the synchronous detection circuit 130. The filter circuit 132 functions as a pre-filter for the A / D conversion circuit 134 in the subsequent stage. The filter circuit 132 also functions as a circuit for attenuating unwanted signals that cannot be completely removed by synchronous detection. The A / D conversion circuit 134 performs A / D conversion of the analog output signal from the filter circuit 132 and outputs digital detection data DQA.

[0042] The processing circuit 150 performs various digital signal processing on the physical quantity detection data DQA from the detection circuit 110. The processing circuit 150 performs temperature correction calculations based on the detection data DQA and temperature detection data. The processing circuit 150 also performs temperature compensation processing on the detection data DQA based on the temperature correction value obtained by the temperature correction calculations. The processing circuit 150 then performs digital filtering such as low-pass filtering and notch filtering on the detection data after the temperature compensation processing.

[0043] As described above, in this embodiment, charge signals from detection electrodes 15B and 16B in addition to detection electrodes 15A and 16A are input to detection circuit 110, and a first sum signal of detection signals S1A and S2B and a second sum signal of detection signals S2A and S1B are input to differential amplifier circuit 128 for differential amplification. In this way, when detecting the same physical quantity such as angular velocity, the amount of charge input to detection circuit 110 increases, thereby improving the detection sensitivity of the physical quantity. This improves the S / N ratio in detecting the physical quantity, making it possible to achieve low noise.

[0044] 2. Amplification circuit Next, the amplifier circuit 120 of this embodiment will be described in detail. As shown in Fig. 1, the amplifier circuit 120 includes switches SW1A, SW1B, SW2A, and SW2B, and a differential amplifier circuit 128. The physical quantity detection element 10 also includes detection arms AS1 and AS2. The detection arms AS1 and AS2 in Fig. 1 are the first detection arm and the second detection arm, respectively, and correspond to the detection arms 19P and 19Q in Fig. 2.

[0045] The detection arm AS1 includes detection electrodes EL1A and EL1B. The detection electrodes EL1A and EL1B are the first and second detection electrodes, respectively, and correspond to detection electrodes 15A and 15B in FIG. 2. The detection arm AS2 includes detection electrodes EL2A and EL2B. The detection electrodes EL2A and EL2B are the third and fourth detection electrodes, respectively, and correspond to detection electrodes 16A and 16B in FIG. 2. Although not particularly limited, the detection electrodes EL1A and EL2A are electrodes formed on, for example, the upper and lower surfaces of the detection arms AS1 and AS2, respectively. The detection electrodes EL1B and EL2B are electrodes formed on, for example, the right and left sides of the detection arms AS1 and AS2, respectively. However, the surfaces on which the detection electrodes are formed may be reversed.

[0046] The terminal T1 is connected to the detection electrode EL1A of the detection arm AS1, and the terminal T2 is connected to the detection electrode EL1B of the detection arm AS1. That is, the first terminal (T1) is connected to the first detection electrode (EL1A) of the first detection arm (AS1), and the second terminal (T2) is connected to the second detection electrode (EL1B) of the first detection arm (AS1). The terminal T3 is connected to the detection electrode EL2A of the detection arm AS2, and the terminal T4 is connected to the detection electrode EL2B of the detection arm AS2. That is, the third terminal (T3) is connected to the third detection electrode (EL2A) of the second detection arm (AS2), and the fourth terminal (T4) is connected to the fourth detection electrode (EL2B) of the second detection arm (AS2). Note that the connection between these detection electrodes and terminals is electrical, and may be via wiring or terminals of a support substrate (relay substrate), for example.

[0047] The detection signal S1A from the detection electrode EL1A of the detection arm AS1 is input to the terminal T1, and the detection signal S1B from the detection electrode EL1B of the detection arm AS1 is input to the terminal T2. That is, the first detection signal (S1A) from the first detection electrode (EL1A) of the first detection arm (AS1) is input to the first terminal (T1), and the second detection signal (S1B) from the second detection electrode (EL1B) of the first detection arm (AS1) is input to the second terminal (T2).

[0048] Furthermore, the detection signal S2A from the detection electrode EL2A of the detection arm AS2 is input to the terminal T3, and the detection signal S2B from the detection electrode EL2B of the detection arm AS2 is input to the terminal T4. That is, the third detection signal (S2A) from the third detection electrode (EL2A) of the second detection arm (AS2) is input to the third terminal (T3), and the fourth detection signal (S2B) from the fourth detection electrode (EL2B) of the second detection arm (AS2) is input to the fourth terminal (T4).

[0049] In this embodiment, in the descriptions "1A," "1B," "2A," and "2B," "1" and "2" indicate that they correspond to the "first" and "second" of the first detection arm (AS1) and the second detection arm (AS2), respectively, and "A" and "B" indicate that they correspond to the top and bottom surfaces, right and left sides of each detection arm, respectively.

[0050] The amplifier circuit 120 includes switches SW1A, SW1B, SW2A, and SW2B and a differential amplifier circuit 128. The switch SW1A is provided between a terminal T1 and an input node NI1 of the differential amplifier circuit 128, and the switch SW1B is provided between a terminal T2 and an input node NI2 of the differential amplifier circuit 128. That is, the first switch (SW1A) is provided between the first terminal (T1) and a first input node (NI1) of the differential amplifier circuit 128, and the second switch (SW1B) is provided between the second terminal (T2) and a second input node (NI2) of the differential amplifier circuit 128.

[0051] The switch SW2A is provided between the terminal T3 and the input node NI2 of the differential amplifier circuit 128, and the switch SW2B is provided between the terminal T4 and the input node NI1 of the differential amplifier circuit 128. That is, the third switch (SW2A) is provided between the third terminal (T3) and the second input node (NI2) of the differential amplifier circuit 128, and the fourth switch (SW2B) is provided between the fourth terminal (T4) and the first input node (NI1) of the differential amplifier circuit 128.

[0052] The input nodes NI1 and NI2 are respectively a first input node and a second input node of the differential amplifier circuit 128. One of the input nodes NI1 and NI2 is one of the nodes at the inverting input terminal and the non-inverting input terminal of the differential amplifier circuit 128, and the other of the input nodes NI1 and NI2 is the other of the nodes at the inverting input terminal and the non-inverting input terminal. The differential amplifier circuit 128 performs differential amplification of a signal I1 input to the input node NI1 and a signal I2 input to the input node NI2.

[0053] 4 is a signal waveform diagram illustrating the operation of the amplifier circuit 120 in the operating mode. In the operating mode, the switches SW1A, SW1B, SW2A, and SW2B in FIG. 1 are turned on, terminals T1 and T4 are connected to input node NI1 of the differential amplifier circuit 128, and terminals T3 and T2 are connected to input node NI2 of the differential amplifier circuit 128. As a result, a first sum signal, which is the sum signal of the detection signals S1A and S2B, is input as signal I1 to input node NI1 of the differential amplifier circuit 128, and a second sum signal, which is the sum signal of the detection signals S2A and S1B, is input as signal I2 to input node NI2 of the differential amplifier circuit 128.

[0054] As shown in Fig. 4, the detection signals S1A and S2B are in-phase signals. Therefore, S1A+S2B, which is a first sum signal (addition signal) of the detection signals S1A and S2B, has an amplitude that is approximately twice that of each of the detection signals S1A and S2B. This first sum signal S1A+S2B is input to an input node NI1 of the differential amplifier circuit 128. For example, S1A+S2B is input to a node at the inverting input terminal of the differential amplifier circuit 128.

[0055] 4, the detection signals S2A and S1B are in-phase signals. Therefore, S2A+S1B, which is a second sum signal (addition signal) of the detection signals S2A and S1B, has an amplitude that is approximately twice that of each of the detection signals S2A and S1B. This second sum signal S2A+S1B is input to an input node NI2 of the differential amplifier circuit 128. For example, S2A+S1B is input to a node at the non-inverting input terminal of the differential amplifier circuit 128.

[0056] The detection signals S1A and S2B and the detection signals S2A and S1B are 180 degrees out of phase with each other and have opposite electrical polarities. For example, if the detection signals S1A and S2B have a first polarity, which is either positive or negative, the detection signals S2A and S1B have a second polarity, which is the other of positive and negative.

[0057] For example, in the detection arm AS1, when a positive charge is generated in the detection electrode EL1A, a negative charge is generated in the detection electrode EL1B, and when a negative charge is generated in the detection electrode EL1A, a positive charge is generated in the detection electrode EL1B. Therefore, the detection signal S1A from the detection electrode EL1A and the detection signal S1B from the detection electrode EL1B are opposite in phase.

[0058] Similarly, in the detection arm AS2, when one of positive and negative charges is generated in the detection electrode EL2A, the other of positive and negative charges is generated in the detection electrode EL2B. Therefore, the detection signal S2A from the detection electrode EL2A and the detection signal S2B from the detection electrode EL2B are signals of opposite phases.

[0059] As shown by the solid and dotted arrows in C3 in FIG. 2, when the detection arm AS1 (19P) bends in the positive direction of the X axis, the detection arm AS2 (19Q) bends in the negative direction of the X axis due to the Coriolis force, and when the detection arm AS1 bends in the negative direction of the X axis, the detection arm AS2 bends in the positive direction of the X axis. Therefore, when one of positive and negative charges is generated on the detection electrode EL1A of the detection arm AS1, the other of positive and negative charges is generated on the detection electrode EL2A of the detection arm AS2. Therefore, the detection signal S1A from the detection electrode EL1A and the detection signal S2A from the detection electrode EL2A are opposite in phase. Similarly, the detection signal S1B from the detection electrode EL1B and the detection signal S2B from the detection electrode EL2B are opposite in phase.

[0060] Therefore, as shown in FIG. 4, the detection signals S1A and S2B are in-phase, the detection signals S2A and S1B are in-phase, and the detection signals S1A and S2B and the detection signals S2A and S1B are out-of-phase.

[0061] 1, the detection signal S2B, which is the charge signal from the detection electrode EL2B, is added to the detection signal S1A, which is the charge signal from the detection electrode EL1A, and the resulting charge signal is input to the input node NI1 of the differential amplifier circuit 128 as a charge signal with double the amplitude. Also, the detection signal S1B, which is the charge signal from the detection electrode EL1B, is added to the detection signal S2A, which is the charge signal from the detection electrode EL2A, and the resulting charge signal is input to the input node NI2 of the differential amplifier circuit 128 as a charge signal with double the amplitude. Therefore, it is possible to essentially double the area of ​​the detection electrodes, thereby improving the physical quantity detection sensitivity of the physical quantity detection device 1. In this embodiment, for convenience, this technique of essentially doubling the area of ​​the detection electrodes will be referred to as double wiring.

[0062] For example, Fig. 5 shows a configuration example of a first comparative example of this embodiment. The comparative example in Fig. 5 differs from Fig. 1 in that in Fig. 5, detection electrode EL1B of detection arm AS1 and detection electrode EL2B of detection arm AS2 are grounded. A detection signal S1 from detection electrode EL1A of detection arm AS1 is input to input node NI1 of differential amplifier circuit 128, and a detection signal S2 from detection electrode EL2A of detection arm AS2 is input to input node NI2 of differential amplifier circuit 128.

[0063] 5, the charges generated at the detection electrode EL1B of the detection arm AS1 and the charges generated at the detection electrode EL2B of the detection arm AS2 are discharged to GND without being input to the differential amplifier circuit 128. Therefore, the amplitude of the detection signal cannot be doubled, which is disadvantageous in that the detection sensitivity is lower than in the configuration of this embodiment shown in FIG.

[0064] Fig. 6 shows a configuration example of a second comparative example of this embodiment. In Fig. 6, a detection signal S1A from the detection electrode EL1A of the detection arm AS1 and a detection signal S2B from the detection electrode EL2B of the detection arm AS2 are input to an input node NI1 of the differential amplifier circuit 128. Furthermore, a detection signal S2A from the detection electrode EL2A of the detection arm AS2 and a detection signal S1B from the detection electrode EL1B of the detection arm AS1 are input to an input node NI2 of the differential amplifier circuit 128. However, it has been found that the second comparative example of Fig. 6 has a problem in that it is not possible to achieve balance tuning, which is an adjustment of the balance of vibration of the physical quantity detection element 10.

[0065] That is, in the physical quantity detection device 1, due to process variations during manufacturing and the like, the vibration balance of each drive arm is poor in the initial state, and unnecessary vibrations are generated in the detection arms when the physical quantity detection element 10 is driven. Therefore, in balance tuning, the detection signals generated by the unnecessary vibrations are measured while the metal weight film of each drive arm is trimmed with an energy beam such as a laser to adjust the frequency and reduce the unnecessary vibrations. In balance tuning, the unnecessary signals generated from the two detection arms are measured individually for each detection arm, and the drive arm to be processed and the amount of processing in that drive arm are calculated according to the measured values.

[0066] However, in the second comparative example of FIG. 6, the unwanted signals generated from the two detection arms are added together and then input to each input node of the differential amplifier circuit 128, which causes a problem that it is not possible to determine which detection arm generated the measured unwanted signal, and therefore it is not possible to calculate the drive arm to be processed and the amount of processing.

[0067] For example, when the drive arms are vibrated and no angular velocity is generated, the detection arms AS1 and AS2 ideally should not vibrate, but before balance tuning, they vibrate due to process variations during manufacturing, etc. For this reason, in balance tuning, unwanted signals due to unwanted vibrations of the detection arms AS1 and AS2 are measured, and the drive arms to be processed and the amount of processing by those drive arms are calculated based on the measured values.

[0068] 5, unwanted vibrations in the detection arm AS1 can be measured based on the output of the differential amplifier circuit 128, in which an unwanted signal from the detection arm AS1 is input to an input node NI1 as a detection signal S1, and unwanted vibrations in the detection arm AS2 can be measured based on the output of the differential amplifier circuit 128, in which an unwanted signal from the detection arm AS2 is input to an input node NI2 as a detection signal S2.

[0069] 6, not only the unwanted signal due to the unwanted vibration of the detection arm AS1 but also the unwanted signal due to the unwanted vibration of the detection arm AS2 is input to the input node NI1 of the differential amplifier circuit 128. Furthermore, not only the unwanted signal due to the unwanted vibration of the detection arm AS2 but also the unwanted signal due to the unwanted vibration of the detection arm AS1 is input to the input node NI2 of the differential amplifier circuit 128. Therefore, the unwanted signals due to the unwanted vibration of each of the detection arms AS1 and AS2 cannot be measured individually, which poses a problem in that appropriate balance tuning cannot be achieved.

[0070] Therefore, in this embodiment, as shown in FIG. 1 , the circuit device 20 is provided with terminals T1 and T2 connected to the detection electrodes EL1A and EL1B of the detection arm AS1 and terminals T3 and T4 connected to the detection electrodes EL2A and EL2B of the detection arm AS2. For example, in the first comparative example of FIG. 5 and the second comparative example of FIG. 6 , only two terminals are provided as terminals connected to the detection electrodes. However, in this embodiment, four terminals, for example, T1, T2, T3, and T4, are provided as terminals connected to the detection electrodes. The detection signals S1A, S1B, S2A, and S2B from the detection electrodes EL1A, EL1B, EL2A, and EL2B can be input to the circuit device 20 via these four terminals T1, T2, T3, and T4. Furthermore, in this embodiment, switches SW1A, SW1B, SW2A, and SW2B are provided between the terminals T1, T2, T3, and T4 and the input node NI1 or the input node NI2 of the differential amplifier circuit 128. Specifically, the switch SW1A is provided between the terminal T1 and the input node NI1, the switch SW1B is provided between the terminal T2 and the input node NI2, the switch SW2A is provided between the terminal T3 and the input node NI2, and the switch SW2B is provided between the terminal T4 and the input node NI1.

[0071] 5, and detection can be performed using double wiring, which doubles the number of detection electrodes. That is, when the switches SW1A, SW1B, SW2A, and SW2B are turned on in the operation mode, the physical quantity detection device 1 performs normal operation. Therefore, when the switches SW1A and SW2B are turned on in the operation mode, the detection signal S1A from the detection electrode EL1A is input to the input node NI1 of the differential amplifier circuit 128 via the terminal T1 and the switch SW1A, and the detection signal S2B from the detection electrode EL2B is input to the input node NI1 of the differential amplifier circuit 128 via the terminal T4 and the switch SW2B. As a result, a first sum signal, which is the sum signal of the detection signal S1A and the detection signal S2B, is input to the input node NI1 of the differential amplifier circuit 128. Furthermore, in the operating mode, when the switches SW2A and SW1B are turned on, the detection signal S2A from the detection electrode EL2A is input to the input node NI2 of the differential amplifier circuit 128 via the terminal T3 and the switch SW2A, and the detection signal S1B from the detection electrode EL1B is input to the input node NI2 of the differential amplifier circuit 128 via the terminal T2 and the switch SW1B. As a result, a second sum signal, which is the sum signal of the detection signals S2A and S1B, is input to the input node NI2 of the differential amplifier circuit 128. Therefore, as described with reference to FIG. 4, the differential amplifier circuit 128 receives the first sum signal of the detection signals S1A and S2B, S1A+S2B, as input to the input node NI1, and the second sum signal of the detection signals S2A and S1B, S2A+S1B, as input to the input node NI2, thereby performing differential amplification of the first sum signal and the second sum signal. This enables detection using double-wiring, which doubles the number of detection electrodes, thereby improving the detection sensitivity of the physical quantity detection device 1.

[0072] On the other hand, in an inspection mode in which balance tuning of the physical quantity detection device 1 is performed, for example, only switch SW1A is turned on, or only switch SW2A is turned on. For example, by turning on only switch SW1A in the inspection mode, the detection signal S1A from the detection electrode EL1A of the detection arm AS1 is input to the differential amplifier circuit 128 via terminal T1 and switch SW1A. In this way, an unwanted signal due to unwanted vibration of the detection arm AS1 is measured and balance tuning can be performed based on the measured value. Also, by turning on only switch SW2A in the inspection mode, the detection signal S2A from the detection electrode EL2A of the detection arm AS2 is input to the differential amplifier circuit 128 via terminal T3 and switch SW2A. In this way, an unwanted signal due to unwanted vibration of the detection arm AS2 is measured and balance tuning can be performed based on the measured value. Therefore, in the inspection mode of the physical quantity detection device 1, the unwanted signals of each detection arm can be individually measured and balance tuning can be performed. As described above, according to the physical quantity detection device 1 of this embodiment, by providing the circuit device 20 with terminals T1, T2, T3, and T4 and switches SW1A, SW1B, SW2A, and SW2B, it is possible to simultaneously achieve improved detection sensitivity through double wiring and balanced tuning by individually measuring unwanted signals from each detection arm.

[0073] As described above, the physical quantity detection device 1 of this embodiment includes, as shown in Fig. 1 and Fig. 2, a physical quantity detection element 10 and a circuit device 20. The physical quantity detection element 10 has a plurality of detection arms (AS1, AS2, 19P, 19Q), a plurality of drive arms (18P to 18S), and a base 21. The circuit device 20 detects a physical quantity based on a plurality of detection signals from the plurality of detection arms.

[0074] 1 and 2, the physical quantity detection element 10 includes a plurality of detection arms, namely, a detection arm AS1 (19P) and a detection arm AS2 (19Q). The detection arm AS1 has detection electrodes EL1A and EL1B and extends from the base 21. The detection arm AS2 has detection electrodes EL2A and EL2B and extends from the base 21 in the opposite direction to the detection arm AS1.

[0075] 1 , the circuit device 20 includes a terminal T1 connected to the detection electrode EL1A, a terminal T2 connected to the detection electrode EL1B, a terminal T3 connected to the detection electrode EL2A, a terminal T4 connected to the detection electrode EL2B, and an amplifier circuit 120. The amplifier circuit 120 includes a differential amplifier circuit 128 and switches SW1A, SW1B, SW2A, and SW2B. The switch SW1A is provided between the terminal T1 and an input node NI1 of the differential amplifier circuit 128, and the switch SW1B is provided between the terminal T2 and an input node NI2 of the differential amplifier circuit 128. The switch SW2A is provided between the terminal T3 and an input node NI2 of the differential amplifier circuit 128, and the switch SW2B is provided between the terminal T4 and the input node NI1 of the differential amplifier circuit 128. For example, other circuits or circuit elements may be arranged between the terminals T1, T2, T3, T4 and the switches SW1A, SW1B, SW2A, SW2B, or between the switches SW1A, SW1B, SW2A, SW2B and the input node NI1 or input node NI2 of the differential amplifier circuit 128. Furthermore, the differential amplifier circuit 128 may have both a charge / voltage conversion function and a differential amplification function, or may have only a differential amplification function.

[0076] According to the physical quantity detecting device 1 of this embodiment having such a configuration, for example, in an operation mode (normal operation), the detection signal S1A from the detection electrode EL1A and the detection signal S2B from the detection electrode EL2B can be input to an input node NI1 of the differential amplifier circuit 128 via the terminal T1 and the switch SW1A, and the terminal T4 and the switch SW2B, respectively. Also, the detection signal S2A from the detection electrode EL2A and the detection signal S1B from the detection electrode EL1B can be input to an input node NI2 of the differential amplifier circuit 128 via the terminal T3 and the switch SW2A, and the terminal T2 and the switch SW1B, respectively. This makes it possible to achieve, for example, improved sensitivity by double wiring. On the other hand, in the test mode (during testing), for example, it is possible to input only the detection signal S1A from the detection electrode EL1A of the detection arm AS1 to the input node NI1 of the differential amplifier circuit 128 via the terminal T1 and the switch SW1A, or to input only the detection signal S2A from the detection electrode EL2A of the detection arm AS2 to the input node NI2 of the differential amplifier circuit 128 via the terminal T3 and the switch SW2A. This makes it possible to individually measure the detection signals of the detection arms AS1 and AS2 and achieve balance tuning and the like. Therefore, it is possible to simultaneously achieve both improved detection sensitivity of the physical quantity and adjustments such as balance tuning.

[0077] Furthermore, in this embodiment, in the operating mode, the switches SW1A, SW1B, SW2A, and SW2B are turned on. In this manner, for example, by turning on the switches SW1A and SW2B, the detection signal S1A from the detection electrode EL1A and the detection signal S2B from the detection electrode EL2B are input to the input node NI1 of the differential amplifier circuit 128. Furthermore, by turning on the switches SW2A and SW1B, the detection signal S2A from the detection electrode EL2A and the detection signal S1B from the detection electrode EL1B are input to the input node NI2 of the differential amplifier circuit 128. This makes it possible to achieve, for example, improved sensitivity by using double wiring.

[0078] In the operation mode, the differential amplifier circuit 128 receives at its input node NI1 a first sum signal of the detection signal S1A input from the detection electrode EL1A via terminal T1 and the detection signal S2B input from the detection electrode EL2B via terminal T4. In the operation mode, the differential amplifier circuit 128 receives at its input node NI2 a second sum signal of the detection signal S2A input from the detection electrode EL2A via terminal T3 and the detection signal S1B input from the detection electrode EL1B via terminal T2. The differential amplifier circuit 128 then performs differential amplification of the first sum signal (S1A+S2B) and the second sum signal (S2A+S1B). In this way, when detecting the same physical quantity, such as angular velocity, the amplitude of the signals input to the input nodes NI1 and NI2 of the differential amplifier circuit 128 increases, thereby improving the detection sensitivity of the physical quantity. This improves the S / N ratio in the detection of the physical quantity, enabling noise reduction.

[0079] In this embodiment, in the inspection mode, switch SW1A is turned on and switches SW1B, SW2A, and SW2B are turned off, or switch SW2A is turned on and switches SW1A, SW1B, and SW2B are turned off. This allows for an inspection mode in which switch SW1A is turned on and switches SW1B, SW2A, and SW2B are turned off, inputting only the detection signal S1A from the detection electrode EL1A of detection arm AS1 to the differential amplifier circuit 128 and measuring an unwanted signal due to unwanted vibration of detection arm AS1. Alternatively, turning switch SW2A on and switches SW1A, SW1B, and SW2B are turned off allows for an inspection mode in which only the detection signal S2A from the detection electrode EL2A of detection arm AS2 is input to the differential amplifier circuit 128 and measuring an unwanted signal due to unwanted vibration of detection arm AS2. This enables adjustments such as balance tuning of the physical quantity detection device 1.

[0080] When the test mode is the first test mode, the switch SW1A is turned on and the switches SW1B, SW2A, and SW2B are turned off. The input node NI2 of the differential amplifier circuit 128 is set to a constant potential, and the differential amplifier circuit 128 amplifies the detection signal S1A input from the detection electrode EL1A to the input node NI1 via the terminal T1 and the switch SW1A. When the test mode is the second test mode, the switch SW2A is turned on and the switches SW1A, SW1B, and SW2B are turned off. The input node NI1 of the differential amplifier circuit 128 is set to a constant potential, and the differential amplifier circuit 128 amplifies the detection signal S2A input from the detection electrode EL2A to the input node NI2 via the terminal T3 and the switch SW2A. In this way, in the first test mode, the detection signal S1A can be input to the input node NI1 of the differential amplifier circuit 128, whose input node NI2 is set to a constant potential, via the terminal T1 and the switch SW1A, and can be amplified. This enables the first test mode to be realized, in which unwanted signals due to unwanted vibrations of the detection arm AS1 are measured. In the second test mode, the detection signal S2A can be input and amplified via the terminal T3 and the switch SW2A to the input node NI2 of the differential amplifier circuit 128, whose input node NI1 is set to a constant potential. This allows the second test mode to be implemented, in which unwanted signals due to unwanted vibrations of the detection arm AS2 are measured.

[0081] In the first inspection mode, switch SW1B sets terminal T2 to a constant potential, and in the second inspection mode, switch SW2B sets terminal T4 to a constant potential. The constant potential is, for example, ground potential. In this manner, in the first inspection mode, switch SW1B sets terminal T2 to a constant potential, thereby setting the detection electrode EL1B connected to terminal T2 to a constant potential. This enables the first inspection mode to be implemented, in which the detection electrode EL1B of detection arm AS1 is set to a constant potential and unwanted signals from detection electrode EL1A are measured to inspect the detection arm AS1 for unwanted vibrations and the like. In the second inspection mode, switch SW2B sets terminal T4 to a constant potential, thereby setting the detection electrode EL2B connected to terminal T4 to a constant potential. This enables the second inspection mode to be implemented, in which the detection electrode EL2B of detection arm AS2 is set to a constant potential and unwanted signals from detection electrode EL2A are measured to inspect the detection arm AS2 for unwanted vibrations and the like.

[0082] Note that when the switches SW1A, SW2A, SW1B, and SW2B are turned on or off, it means that the connection between the terminals T1, T2, T3, and T4 and the input node NI1 or the input node NI2 of the differential amplifier circuit 128 is turned on or off. For example, when the switch SW1A is turned on and the switches SW1B, SW2A, and SW2B are turned off in the first inspection mode, the connection between the terminal T1 and the input node NI1 by SW1A is turned on, and the connection between the terminals T2, T3, and T4 and the input node NI1 or the input node NI2 by SW1B, SW2A, and SW2B is turned off. In this case, the connection destination of the switch SW1B is a constant potential such as ground. In the second test mode, when the switch SW2A is turned on and the switches SW1A, SW1B, and SW2B are turned off, the connection between the terminal T3 and the input node NI2 by SW2A is turned on, and the connections between the terminals T1, T2, and T4 and the input node NI1 or NI2 by SW1A, SW1B, and SW2B are turned off. In this case, the connection destination of the switch SW2B is a constant potential such as ground.

[0083] 3. Detailed configuration example 3.1 First configuration example Next, detailed configuration examples of this embodiment will be described. FIG. 7 shows a first configuration example of the amplifier circuit 120. In the first configuration example of FIG. 7, the switches SW1A, SW1B, SW2A, and SW2B are, for example, three-terminal switches, and are capable of turning on or off the connection between terminals T1, T2, T3, and T4 and the input node NI1 or input node NI2 of the differential amplifier circuit 128, or setting the terminals T1, T2, T3, and T4 to a constant potential such as ground. The switches SW1A, SW1B, SW2A, and SW2B in the second and third configuration examples described below are also capable of similar switching. For example, the switch SW1A is capable of turning on or off the connection between terminal T1 and the input node NI1 of the differential amplifier circuit 128, or setting the terminal T1 to ground (constant potential in a broad sense; the same applies below). The switch SW2A is capable of turning on or off the connection between terminal T2 and the input node NI2 of the differential amplifier circuit 128, or setting the terminal T2 to ground. The same applies to the switches SW2A and SW2B. Note that the function of setting the terminal to ground may be provided only to the switches SW1B and SW2B, and the function may not be provided to the switches SW1A and SW2A.

[0084] The differential amplifier circuit 128 includes an operational amplifier OP, feedback resistors R1 and R2, and capacitors C1 and C2. The operational amplifier OP has, for example, an inverting input terminal connected to an input node NI1 and a non-inverting input terminal connected to an input node NI2. The operational amplifier OP has a non-inverting output terminal connected to an output node NQ1 and an inverting output terminal connected to an output node NQ2. The output nodes NQ1 and NQ2 are the first and second output nodes of the differential amplifier circuit 128, respectively. The resistor R1 and the capacitor C1 are connected in parallel between the input node NI1 and the output node NQ1. The resistor R2 and the capacitor C2 are connected in parallel between the input node NI2 and the output node NQ2. The differential amplifier circuit 128 configured as described above can be used as a differential amplifier charge-voltage conversion circuit (Q / V conversion circuit) having both a charge-voltage conversion function for converting a charge signal into a voltage signal and a differential amplification function for amplifying a differential signal.

[0085] 7 also includes switches SW5 and SW6. One end of the switch SW5 is connected to an input node NI1 of the differential amplifier circuit 128, and the other end is set to a constant potential such as ground. One end of the switch SW6 is connected to an input node NI2 of the differential amplifier circuit 128, and the other end is set to a constant potential such as ground. The switches SW5 and SW6 are a fifth switch and a sixth switch, respectively.

[0086] In the first configuration example, in the operating mode, the switches SW1A, SW1B, SW2A, SW2B, SW5, and SW6 are connected as shown in FIG. 7 . That is, the switch SW1A connects the terminal T1 to the input node NI1, and the switch SW1B connects the terminal T2 to the input node NI2. The switch SW2A connects the terminal T3 to the input node NI2, and the switch SW2B connects the terminal T4 to the input node NI1. The switches SW5 and SW6 are turned off, and the connections to ground are cut off. In this manner, a first sum signal of the detection signal S1A input from the detection electrode EL1A via the terminal T1 and the detection signal S2B input from the detection electrode EL2B via the terminal T4 is input to the input node NI1 of the differential amplifier circuit 128. A second sum signal of the detection signal S2A input from the detection electrode EL2A via the terminal T3 and the detection signal S1B input from the detection electrode EL1B via the terminal T2 is input to the input node NI2 of the differential amplifier circuit 128. The differential amplifier circuit 128 performs differential amplification of the first sum signal and the second sum signal, thereby improving the detection sensitivity of the physical quantity.

[0087] On the other hand, in the first configuration example, in the first inspection mode for inspecting the detection arm AS1, the switches SW1A, SW1B, SW2A, SW2B, SW5, and SW6 are connected as shown in FIG. 8 . That is, the switch SW1A is turned on, turning on the connection between the terminal T1 and the input node NI1. Meanwhile, the connections of the switches SW1B, SW2A, and SW2B between the terminals T2, T3, and T4 and the input node NI1 or the input node NI2 are turned off. The connection destination of the switch SW1B is ground, and the terminal T2 is set to ground, which is a constant potential. Furthermore, the switch SW5 is turned off, while the switch SW6 is turned on. As a result, the input node NI2 is set to ground, which is a constant potential.

[0088] In this manner, the detection signal S1A from the detection electrode EL1A of the detection arm AS1 is input to the input node NI1 of the differential amplifier circuit 128 via terminal T1 and switch SW1A. Furthermore, by connecting switch SW1B to ground and setting terminal T2 to ground, the detection electrode EL1B of the detection arm AS1 is set to ground. By turning off switches SW2A and SW2B, the detection signal S2A from the detection electrode EL2A of the detection arm AS2 and the detection signal S2B from the detection electrode EL2B of the detection arm AS2 are not input to the differential amplifier circuit 128. By turning on switch SW6, the input node NI2 of the differential amplifier circuit 128 is set to ground, which is a constant potential. This enables balance tuning, in which the detection signal S1A from the detection electrode EL1A of the detection arm AS1 is measured as an unwanted signal to measure unwanted vibrations of the detection arm AS1. Balance tuning measures the unwanted signals generated by the detection arm AS1, and calculates the drive arm to be machined and the amount of machining in that drive arm based on the measured values.

[0089] In the second test mode for testing the detection arm AS2, the switches SW1A, SW1B, SW2A, SW2B, SW5, and SW6 are connected as shown in FIG. 9. That is, the switch SW2A is turned on, turning on the connection between the terminal T3 and the input node NI2. Meanwhile, the connections of the switches SW1A, SW1B, and SW2B between the terminals T1, T2, and T4 and the input node NI1 or NI2 are turned off. The connection destination of the switch SW2B is ground, and the terminal T4 is set to ground, which is a constant potential. The switch SW6 is turned off, while the switch SW5 is turned on. As a result, the input node NI1 is set to ground, which is a constant potential.

[0090] In this way, the detection signal S2A from the detection electrode EL2A of the detection arm AS2 is input to the input node NI2 of the differential amplifier circuit 128 via terminal T3 and switch SW2A. Furthermore, by connecting switch SW2B to ground and setting terminal T4 to ground, the detection electrode EL2B of the detection arm AS2 is set to ground. Turning switches SW1A and SW1B off prevents the detection signals S1A and S1B from the detection electrodes EL1A and EL1B of the detection arm AS1 from being input to the differential amplifier circuit 128. Turning switch SW5 on sets the input node NI1 of the differential amplifier circuit 128 to ground, which is a constant potential. This allows the detection signal S2A from the detection electrode EL2A of the detection arm AS2 to be measured as an unwanted signal, thereby achieving balance tuning to measure unwanted vibrations of the detection arm AS2.

[0091] FIG. 10 is an explanatory diagram summarizing the operation of the first configuration example. As shown in FIG. 10, in the first inspection mode for measuring S1A of the detection arm AS1, switch SW1A is connected to the differential amplifier circuit 128, and switch SW1B is connected to ground. Switches SW2A, SW2B, and SW5 are turned off, and switch SW6 is connected to ground. This sets the detection electrode EL1B of the detection arm AS1 to ground, and the detection signal S1A from the detection electrode EL1A is input to the input node NI1 on the inverting input terminal side of the differential amplifier circuit 128 via terminal T1 and switch SW1A. Furthermore, the input node NI2 on the non-inverting input terminal side of the differential amplifier circuit 128 is set to ground. Therefore, by measuring the output signals Q1 and Q2 of the differential amplifier circuit 128, unwanted vibrations in the detection arm AS1 can be detected, enabling balance tuning.

[0092] In the second test mode, which measures S2A of the detection arm AS2, switch SW2A is connected to the differential amplifier circuit 128 and switch SW2B is connected to ground. Switches SW1A, SW1B, and SW6 are turned off, and switch SW5 is connected to ground. This sets the detection electrode EL2B of the detection arm AS2 to ground, and the detection signal S2A from the detection electrode EL2A is input to the input node NI2 on the non-inverting input terminal side of the differential amplifier circuit 128 via terminal T3 and switch SW2A. The input node NI1 on the inverting input terminal side of the differential amplifier circuit 128 is also set to ground. Therefore, by measuring the output signals Q1 and Q2 of the differential amplifier circuit 128, unwanted vibrations in the detection arm AS2 can be detected and balance tuning can be performed.

[0093] As described above, in this embodiment, when the test mode is the first test mode, the switch SW1A is turned on and the switches SW1B, SW2A, and SW2B are turned off. For example, the switch SW1B turns off the connection between the terminal T2 and the input node NI2 and is connected to ground, setting the terminal T2 to ground. The differential amplifier circuit 128 sets the input node NI2 to ground by the switch SW6, and amplifies the detection signal S1A input from the detection electrode EL1A to the input node NI1 via the terminal T1 and the switch SW1A. When the test mode is the second test mode, the switch SW2A is turned on and the switches SW1A, SW1B, and SW2B are turned off. For example, the switch SW2B turns off the connection between the terminal T4 and the input node NI1 and is connected to ground, setting the terminal T4 to ground. The differential amplifier circuit 128 has an input node NI1 set to ground by the switch SW5, and amplifies the detection signal S2A input from the detection electrode EL2A to the input node NI2 via the terminal T3 and the switch SW2A.

[0094] 10, S1B may be measured to measure unwanted vibrations in the detection arm AS1, or S2B may be measured to measure unwanted vibrations in the detection arm AS2. When measuring S1B, the switch SW1B is connected to the differential amplifier circuit 128, and the switches SW1A and SW5 are connected to ground. When measuring S2B, the switch SW2B is connected to the differential amplifier circuit 128, and the switches SW2A and SW6 are connected to ground.

[0095] For example, ideally, after balance tuning, the levels of unwanted signals in S1A, S1B, S2A, and S2B would all be 0, but when balance tuning is performed to reduce the levels of unwanted signals in S1A and S2A to 0 by measuring S1A and S2A, there are cases where the levels of unwanted signals in S1B and S2B do not become 0. Therefore, it is desirable to measure all of S1A, S1B, S2A, and S2B, and perform balance tuning so that the levels of unwanted signals in S1A, S1B, S2A, and S2B are reduced equally.

[0096] 3.2 Second configuration example 11 shows a second configuration example of the amplifier circuit 120. In FIG. 11, the amplifier circuit 120 is further provided with amplifier circuits 121 and 122 in addition to switches SW1A, SW1B, SW2A, and SW2B and a differential amplifier circuit 128. The amplifier circuit 120 is also provided with switches SWD5 and SWD6. The amplifier circuits 121 and 122 are a first amplifier circuit and a second amplifier circuit, respectively. The switches SWD5 and SWD6 are a fifth switch and a sixth switch, respectively.

[0097] For example, the amplifier circuit 121 is provided between the switches SW1A and SW2B and the input node NI1 of the differential amplifier circuit 128. The amplifier circuit 122 is provided between the switches SW2A and SW1B and the input node NI2 of the differential amplifier circuit 128. The switch SWD5 has one end connected to the input node NI1 of the differential amplifier circuit 128 and the other end connected to ground, which is a constant potential. The switch SWD6 has one end connected to the input node NI2 of the differential amplifier circuit 128 and the other end connected to ground, which is a constant potential. As described above, the switches SW1A, SW1B, SW2A, and SW2B only need to be provided between at least the terminals T1, T2, T3, and T4 and the input node NI1 or the input node NI2 of the differential amplifier circuit 128. For example, as shown in FIG. 11 , circuits or circuit elements such as the amplifier circuits 121 and 122 may be provided between the switches SW1A, SW1B, SW2A, and SW2B and the input node NI1 or the input node NI2 of the differential amplifier circuit 128.

[0098] The amplifier circuit 121 includes an operational amplifier OPD1 and a feedback resistor RD1 and capacitor CD1. One ends of switches SW1A and SW2B are connected to an input node NID1 on the inverting input terminal side of the operational amplifier OPD1, and the non-inverting input terminal is set to ground, which is a constant potential. The resistor RD1 and capacitor CD1 are provided in parallel between the input node NID1 and output node NQD1 of the amplifier circuit 121. The input node NI1 of the differential amplifier circuit 128 is connected to the output node NQD1 of the amplifier circuit 121.

[0099] The amplifier circuit 122 also includes an operational amplifier OPD2, and a feedback resistor RD2 and capacitor CD2. One end of switches SW2A and SW1B is connected to an input node NID2 on the inverting input terminal side of the operational amplifier OPD2, and the non-inverting input terminal is set to ground, which is a constant potential. The resistor RD2 and capacitor CD2 are connected in parallel between the input node NID2 and output node NQD2 of the amplifier circuit 122. An input node NI2 of the differential amplifier circuit 128 is connected to the output node NQD2 of the amplifier circuit 122. These amplifier circuits 121 and 122 are charge / voltage conversion circuits that convert charge signals S1A, S1B, S2A, and S2B into voltage signals.

[0100] In the second configuration example, in the operating mode, the switches SW1A, SW1B, SW2A, SW2B, SWD5, and SWD6 are connected as shown in FIG. 11 . That is, when the switches SW1A and SW2B are turned on, the terminals T1 and T4 are connected to the input node NI1 of the differential amplifier circuit 128 via the amplifier circuit 121. When the switches SW2A and SW1B are turned on, the terminals T3 and T2 are connected to the input node NI2 of the differential amplifier circuit 128 via the amplifier circuit 122. In this manner, a first sum signal of the detection signal S1A input to the terminal T1 and the detection signal S2B input to the terminal T4 is input to the input node NI1 of the differential amplifier circuit 128 via the amplifier circuit 121. A second sum signal of the detection signal S2A input to the terminal T3 and the detection signal S1B input to the terminal T2 is input to the input node NI2 of the differential amplifier circuit 128 via the amplifier circuit 122. Then, differential amplifier circuit 128 performs differential amplification of the first sum signal and the second sum signal, making it possible to improve the detection sensitivity of the physical quantity.

[0101] On the other hand, in a first inspection mode for inspecting the detection arm AS1, the switches SW1A, SW1B, SW2A, SW2B, SWD5, and SWD6 are connected as shown in FIG. 12. When the switch SW1A is turned on, the detection signal S1A from the detection electrode EL1A of the detection arm AS1 is input to the input node NI1 of the differential amplifier circuit 128 via terminal T1, the switch SW1A, and the amplifier circuit 121. When the switch SW1B is connected to ground, the detection electrode EL1B of the detection arm AS1 is set to ground. When the switches SW2A and SW2B are turned off, the detection signals S2A and S2B from the detection electrodes EL2A and EL2B of the detection arm AS2 are not input to the differential amplifier circuit 128. When the switch SWD6 is turned on, the input node NI2 of the differential amplifier circuit 128 is set to ground. This makes it possible to realize balance tuning in which the detection signal S1A from the detection electrode EL1A of the detection arm AS1 is measured as an unwanted signal and unwanted vibrations of the detection arm AS1 are measured.

[0102] In the second inspection mode for inspecting the detection arm AS2, the switches SW1A, SW1B, SW2A, SW2B, SWD5, and SWD6 are connected as shown in FIG. 13. When the switch SW2A is turned on, the detection signal S2A from the detection electrode EL2A of the detection arm AS2 is input to the input node NI2 of the differential amplifier circuit 128 via terminal T3, the switch SW2A, and the amplifier circuit 122. When the switch SW2B is connected to ground, the detection electrode EL2B of the detection arm AS2 is set to ground. When the switches SW1A and SW1B are turned off, the detection signals S1A and S1B from the detection electrodes EL1A and EL1B of the detection arm AS1 are not input to the differential amplifier circuit 128. When the switch SWD5 is turned on, the input node NI1 of the differential amplifier circuit 128 is set to ground. This allows the detection signal S2A from the detection electrode EL2A of the detection arm AS2 to be measured as an unwanted signal, thereby achieving balance tuning for measuring unwanted vibrations of the detection arm AS2.

[0103] Figure 14 is an explanatory diagram summarizing the operation of the second configuration example. The operation of the second configuration example is the same as that explained in Figures 11, 12, and 13, so a detailed explanation of Figure 14 will be omitted. Also, as in Figure 10, Figure 14 shows the connection state of the switches when measuring S1B and S2B.

[0104] As described above, in the second configuration example of FIG. 11, the amplifier circuit 120 includes an amplifier circuit 121 provided between the switches SW1A, SW2B and the input node NI1 of the differential amplifier circuit 128, and an amplifier circuit 122 provided between the switches SW2A, SW1B and the input node NI2 of the differential amplifier circuit 128.

[0105] In this way, the detection signal S1A can be input to the input node NI1 of the differential amplifier circuit 128 via the switch SW1A and the amplifier circuit 121. The detection signal S2B can be input to the input node NI1 of the differential amplifier circuit 128 via the switch SW2B and the amplifier circuit 121. Furthermore, the detection signal S2A can be input to the input node NI2 of the differential amplifier circuit 128 via the switch SW2A and the amplifier circuit 122, and the detection signal S1B can be input to the input node NI2 of the differential amplifier circuit 128 via the switch SW1B and the amplifier circuit 122.

[0106] As a result, for example, in operation mode, a first sum signal of detection signals S1A and S2B can be input to input node NI1 of differential amplifier circuit 128 via amplifier circuit 121, and a second sum signal of detection signals S2A and S1B can be input to input node NI2 of differential amplifier circuit 128 via amplifier circuit 122. The differential amplifier circuit 128 then performs differential amplification of the first sum signal and the second sum signal, thereby improving the detection sensitivity of the physical quantity. Furthermore, in inspection mode, the detection signal S1A can be input to input node NI1 of differential amplifier circuit 128 via switch SW1A and amplifier circuit 121 to measure the unwanted signal in detection arm AS1, and the detection signal S2A can be input to input node NI2 of differential amplifier circuit 128 via switch SW2A and amplifier circuit 122 to measure the unwanted signal in detection arm AS2. This allows the unwanted signals of each detection arm to be measured individually, enabling balance tuning and other operations to be performed.

[0107] In the second configuration example, in the operation mode, the switches SW1A, SW1B, SW2A, and SW2B are turned on. On the other hand, in the inspection mode, the switch SW1A is turned on and the switches SW1B, SW2A, and SW2B are turned off, or the switch SW2A is turned on and the switches SW1A, SW1B, and SW2B are turned off. In this manner, in the operation mode, when the switches SW1A and SW2B are turned on, the detection signals S1A and S2B from the detection electrodes EL1A and EL2B are input to the input node NI1 of the differential amplifier circuit 128. When the switches SW2A and SW1B are turned on, the detection signals S2A and S1B from the detection electrodes EL2A and EL1B are input to the input node NI2 of the differential amplifier circuit 128. This improves the detection sensitivity of the physical quantity. In the inspection mode, the switch SW1A is turned on and the switches SW1B, SW2A, and SW2B are turned off, so that only the detection signal S1A from the detection electrode EL1A of the detection arm AS1 is input to the differential amplifier circuit 128, thereby enabling measurement of the unwanted signal in the detection arm AS1. Alternatively, the switch SW2A is turned on and the switches SW1A, SW1B, and SW2B are turned off, so that only the detection signal S2A from the detection electrode EL2A of the detection arm AS2 is input to the differential amplifier circuit 128, thereby enabling measurement of the unwanted signal in the detection arm AS2. This enables adjustments such as balance tuning of the physical quantity detection device 1.

[0108] In the second configuration example, the amplifier circuit 120 includes a switch SWD5 having one end connected to an input node NI1 of the differential amplifier circuit 128 and the other end set to ground, which is a constant potential, and a switch SWD6 having one end connected to an input node NI2 of the differential amplifier circuit 128 and the other end set to ground, which is a constant potential. In the operation mode, the switches SWD5 and SWD6 are turned off, and in the test mode, either the switch SWD5 or the switch SWD6 is turned on. For example, in a first test mode in which S1A is measured, the switch SWD6 is turned on, and in a second test mode in which S2A is measured, the switch SWD5 is turned on. In this way, in the test mode in which the detection signal S1A is input to the input node NI1 of the differential amplifier circuit 128 for measurement, the input node NI2 of the differential amplifier circuit 128 is set to ground, which is a constant potential, so that the detection signal S1A can be properly measured. In addition, in the test mode in which the detection signal S2A is input to the input node NI2 of the differential amplifier circuit 128 for measurement, the input node NI1 of the differential amplifier circuit 128 is set to the ground, which is a constant potential, so that the detection signal S2A can be measured properly.

[0109] 3.3 Third configuration example FIG. 15 shows a third configuration example of the amplifier circuit 120. In FIG. 15, in addition to switches SW1A, SW1B, SW2A, and SW2B and a differential amplifier circuit 128, amplifier circuits 123, 124, 125, and 126 are further provided in the amplifier circuit 120. Switches SWE5 and SWE6 are also provided in the amplifier circuit 120. The amplifier circuits 123, 124, 125, and 126 are a first amplifier circuit, a second amplifier circuit, a third amplifier circuit, and a fourth amplifier circuit, respectively. Switch SWE5 is a fifth switch, and switch SWE6 is a sixth switch.

[0110] For example, the amplifier circuit 123 is provided between the terminal T1 and the switch SW1A, and the amplifier circuit 124 is provided between the terminal T2 and the switch SW1B. The amplifier circuit 125 is provided between the terminal T3 and the switch SW2A, and the amplifier circuit 126 is provided between the terminal T4 and the switch SW2B. The switch SWE5 has one end connected to the input node NI1 of the differential amplifier circuit 128 and the other end set to the ground, which is a constant potential. The switch SWE6 has one end connected to the input node NI2 of the differential amplifier circuit 128 and the other end set to the ground, which is a constant potential. In this way, the switches SW1A, SW1B, SW2A, and SW2B only need to be provided between at least the terminals T1, T2, T3, and T4 and the input node NI1 or the input node NI2 of the differential amplifier circuit 128. For example, as shown in FIG. 15, circuits and circuit elements such as amplifier circuits 123, 124, 125, and 126 may be provided between terminals T1, T2, T3, and T4 and switches SW1A, SW1B, SW2A, and SW2B.

[0111] The amplifier circuit 123 includes an operational amplifier OPE1, and a feedback resistor RE1 and capacitor CE1. A terminal T1 is connected to an input node NIE1 on the inverting input terminal side of the operational amplifier OPE1, and the non-inverting input terminal is set to ground. The resistor RE1 and capacitor CE1 are provided in parallel between the input node NIE1 and output node NQE1 of the amplifier circuit 123. One end of a switch SW1A is connected to the output node NQE1 of the amplifier circuit 123.

[0112] The amplifier circuit 124 includes an operational amplifier OPE2, and a feedback resistor RE2 and capacitor CE2. A terminal T2 is connected to an input node NIE2 on the inverting input terminal side of the operational amplifier OPE2, and the non-inverting input terminal is set to ground. The resistor RE2 and capacitor CE2 are provided in parallel between the input node NIE2 and output node NQE2 of the amplifier circuit 124. One end of a switch SW1B is connected to the output node NQE2 of the amplifier circuit 124.

[0113] The amplifier circuit 125 includes an operational amplifier OPE3, and a feedback resistor RE3 and capacitor CE3. A terminal T3 is connected to an input node NIE3 on the inverting input terminal side of the operational amplifier OPE3, and the non-inverting input terminal is set to ground. The resistor RE3 and capacitor CE3 are provided in parallel between the input node NIE3 and output node NQE3 of the amplifier circuit 125. One end of a switch SW2A is connected to the output node NQE3 of the amplifier circuit 125.

[0114] The amplifier circuit 126 includes an operational amplifier OPE4 and a feedback resistor RE4 and capacitor CE4. A terminal T4 is connected to an input node NIE4 on the inverting input terminal side of the operational amplifier OPE4, and the non-inverting input terminal is set to ground. The resistor RE4 and capacitor CE4 are provided in parallel between the input node NIE4 and output node NQE4 of the amplifier circuit 126. One end of a switch SW2B is connected to the output node NQE4 of the amplifier circuit 126. These amplifier circuits 123, 124, 125, and 126 are charge / voltage conversion circuits that convert the charge signals S1A, S1B, S2A, and S2B into voltage signals.

[0115] One end of the switches SW1A, SW1B, SW2A, and SW2B is connected to output nodes NQE1, NQE2, NQE3, and NQE4, respectively, of the amplifier circuits 123, 124, 125, and 126. The other ends of the switches SW1A and SW2B are connected to an input node NI1 of a differential amplifier circuit 128, and the other ends of the switches SW2A and SW1B are connected to an input node NI2 of the differential amplifier circuit 128.

[0116] In the third configuration example, in the operating mode, the switches SW1A, SW1B, SW2A, SW2B, SWE5, and SWE6 are connected as shown in FIG. 15. That is, when the switches SW1A and SW2B are turned on, the terminals T1 and T4 are connected to the input node NI1 of the differential amplifier circuit 128 via the amplifier circuits 123 and 126, respectively. When the switches SW2A and SW1B are turned on, the terminals T3 and T2 are connected to the input node NI2 of the differential amplifier circuit 128 via the amplifier circuits 125 and 124, respectively. In this way, a first sum signal of the detection signal S1A input from the terminal T1 via the amplifier circuit 123 and the detection signal S2B input from the terminal T4 via the amplifier circuit 126 is input to the input node NI1 of the differential amplifier circuit 128. Furthermore, a second sum signal of detection signal S2A input from terminal T3 via amplifier circuit 125 and detection signal S1B input from terminal T2 via amplifier circuit 124 is input to input node NI2 of differential amplifier circuit 128. Differential amplifier circuit 128 performs differential amplification of the first sum signal and the second sum signal, thereby improving the detection sensitivity of the physical quantity.

[0117] On the other hand, in a first inspection mode for inspecting the detection arm AS1, the switches SW1A, SW1B, SW2A, SW2B, SWE5, and SWE6 are connected as shown in FIG. 16. When the switch SW1A is turned on, the detection signal S1A from the detection electrode EL1A of the detection arm AS1 is input to the input node NI1 of the differential amplifier circuit 128 via the terminal T1, the amplifier circuit 123, and the switch SW1A. When the switch SW1B is connected to ground, the detection electrode EL1B of the detection arm AS1 is set to ground. When the switches SW2A and SW2B are turned off, the detection signals S2A and S2B from the detection electrodes EL2A and EL2B of the detection arm AS2 are not input to the differential amplifier circuit 128. When the switch SWE6 is turned on, the input node NI2 of the differential amplifier circuit 128 is set to ground. This makes it possible to realize balance tuning in which the detection signal S1A from the detection electrode EL1A of the detection arm AS1 is measured as an unwanted signal and unwanted vibrations of the detection arm AS1 are measured.

[0118] In the second inspection mode for inspecting the detection arm AS2, the switches SW1A, SW1B, SW2A, SW2B, SWE5, and SWE6 are connected as shown in FIG. 17. When the switch SW2A is turned on, the detection signal S2A from the detection electrode EL2A of the detection arm AS2 is input to the input node NI2 of the differential amplifier circuit 128 via terminal T3, the amplifier circuit 125, and the switch SW2A. When the switch SW2B is connected to ground, the detection electrode EL2B of the detection arm AS2 is set to ground. When the switches SW1A and SW1B are turned off, the detection signals S1A and S1B from the detection electrodes EL1A and EL1B of the detection arm AS1 are not input to the differential amplifier circuit 128. When the switch SWE5 is turned on, the input node NI1 of the differential amplifier circuit 128 is set to ground. This allows the detection signal S2A from the detection electrode EL2A of the detection arm AS2 to be measured as an unwanted signal, thereby achieving balance tuning for measuring unwanted vibrations of the detection arm AS2.

[0119] Figure 18 is an explanatory diagram summarizing the operation of the third configuration example. The operation of the third configuration example is the same as that explained in Figures 15, 16, and 17, so a detailed explanation of Figure 18 will be omitted. Also, as in Figures 10 and 14, Figure 18 shows the connection state of the switches when measuring S1B and S2B.

[0120] As described above, the third configuration example of FIG. 15 includes an amplifier circuit 123 provided between terminal T1 and switch SW1A, an amplifier circuit 124 provided between terminal T2 and switch SW1B, an amplifier circuit 125 provided between terminal T3 and switch SW2A, and an amplifier circuit 126 provided between terminal T4 and switch SW2B.

[0121] In this way, the detection signal S1A can be input to the input node NI1 of the differential amplifier circuit 128 via the amplifier circuit 123 and the switch SW1A. The detection signal S2B can be input to the input node NI1 of the differential amplifier circuit 128 via the amplifier circuit 126 and the switch SW2B. The detection signal S2A can also be input to the input node NI2 of the differential amplifier circuit 128 via the amplifier circuit 125 and the switch SW2A, and the detection signal S1B can also be input to the input node NI2 of the differential amplifier circuit 128 via the amplifier circuit 124 and the switch SW1B.

[0122] As a result, for example, in operation mode, the detection signals S1A and S2B can be input via the amplifier circuit 123 and switch SW1A, and via the amplifier circuit 126 and switch SW2B, respectively, and a first sum signal thereof can be input to the input node NI1 of the differential amplifier circuit 128. Also, the detection signals S2A and S1B can be input via the amplifier circuit 125 and switch SW2A, and via the amplifier circuit 124 and switch SW1B, respectively, and a second sum signal thereof can be input to the input node NI2 of the differential amplifier circuit 128. The differential amplifier circuit 128 then performs differential amplification of the first sum signal and the second sum signal, thereby improving the detection sensitivity of the physical quantity. Also, in inspection mode, the detection signal S1A can be input via the amplifier circuit 123 and switch SW1A to the input node NI1 of the differential amplifier circuit 128 to measure the unwanted signal in the detection arm AS1, and the detection signal S2A can be input via the amplifier circuit 125 and switch SW2A to the input node NI2 of the differential amplifier circuit 128 to measure the unwanted signal in the detection arm AS2. This makes it possible to measure the unwanted signals from each detection arm individually and perform balance tuning, etc.

[0123] In the third configuration example, in the operation mode, the switches SW1A, SW1B, SW2A, and SW2B are turned on. Meanwhile, in the inspection mode, the switch SW1A is turned on and the switches SW1B, SW2A, and SW2B are turned off, or the switch SW2A is turned on and the switches SW1A, SW1B, and SW2B are turned off. In this manner, in the operation mode, the switches SW1A and SW2B are turned on, so that the detection signals S1A and S2B from the detection electrodes EL1A and EL2B are input to the input node NI1 of the differential amplifier circuit 128. Furthermore, the switches SW2A and SW1B are turned on, so that the detection signals S2A and S1B from the detection electrodes EL2A and EL1B are input to the input node NI2 of the differential amplifier circuit 128. This improves the detection sensitivity of the physical quantity. In the inspection mode, the switch SW1A is turned on and the switches SW1B, SW2A, and SW2B are turned off, so that only the detection signal S1A from the detection electrode EL1A of the detection arm AS1 is input to the differential amplifier circuit 128, thereby enabling measurement of the unwanted signal in the detection arm AS1. Alternatively, the switch SW2A is turned on and the switches SW1A, SW1B, and SW2B are turned off, so that only the detection signal S2A from the detection electrode EL2A of the detection arm AS2 is input to the differential amplifier circuit 128, thereby enabling measurement of the unwanted signal in the detection arm AS2. This enables adjustments such as balance tuning of the physical quantity detection device 1.

[0124] In the third configuration example, the amplifier circuit 120 includes a switch SWE5 having one end connected to an input node NI1 of the differential amplifier circuit 128 and the other end set to ground, which is a constant potential, and a switch SWE6 having one end connected to an input node NI2 of the differential amplifier circuit 128 and the other end set to ground, which is a constant potential. In the operation mode, the switches SWE5 and SWE6 are turned off, and in the test mode, either the switch SWE5 or the switch SWE6 is turned on. For example, in a first test mode in which S1A is measured, the switch SWE6 is turned on, and in a second test mode in which S2A is measured, the switch SWE5 is turned on. In this way, in the test mode in which the detection signal S1A is input to the input node NI1 of the differential amplifier circuit 128 for measurement, the input node NI2 of the differential amplifier circuit 128 is set to ground, allowing the detection signal S1A to be properly measured. In the test mode in which the detection signal S2A is input to the input node NI2 of the differential amplifier circuit 128 for measurement, the input node NI1 of the differential amplifier circuit 128 is set to ground, allowing the detection signal S2A to be measured properly.

[0125] As described above, the physical quantity detection device of this embodiment includes a physical quantity detection element having multiple detection arms, multiple drive arms, and a base, and a circuit device that detects a physical quantity based on multiple detection signals from the multiple detection arms of the physical quantity detection element. The physical quantity detection element also includes, as the multiple detection arms, a first detection arm having a first detection electrode and a second detection electrode and extending from the base, and a second detection arm having a third detection electrode and a fourth detection electrode and extending from the base in a direction opposite to the first detection arm. The circuit device also includes a first terminal connected to the first detection electrode, a second terminal connected to the second detection electrode, a third terminal connected to the third detection electrode, a fourth terminal connected to the fourth detection electrode, and an amplifier circuit. The amplifier circuit also includes a differential amplifier circuit, a first switch provided between the first terminal and a first input node of the differential amplifier circuit, a second switch provided between the second terminal and a second input node of the differential amplifier circuit, a third switch provided between the third terminal and the second input node of the differential amplifier circuit, and a fourth switch provided between the fourth terminal and the first input node of the differential amplifier circuit.

[0126] According to this embodiment, for example, the first detection signal from the first detection electrode and the fourth detection signal from the fourth detection electrode can be input to the first input node of the differential amplifier circuit via the first terminal and the first switch, and the fourth terminal and the fourth switch, respectively. Furthermore, the third detection signal from the third detection electrode and the second detection signal from the second detection electrode can be input to the second input node of the differential amplifier circuit via the third terminal and the third switch, and the second terminal and the second switch, respectively. This improves the detection sensitivity of the physical quantity. It is also possible to input only the first detection signal from the first detection electrode of the first detection arm to the first input node of the differential amplifier circuit via the first terminal and the first switch, or to input only the third detection signal from the third detection electrode of the second detection arm to the second input node of the differential amplifier circuit via the third terminal and the third switch. This makes it possible to individually measure the detection signals of the first detection arm and the second detection arm. Therefore, it is possible to simultaneously improve the detection sensitivity of the physical quantity and individually measure the detection signals of the detection arms.

[0127] In this embodiment, the first switch, the second switch, the third switch, and the fourth switch may be turned on in the operation mode.

[0128] In this way, when the first switch and the fourth switch are turned on, the first detection signal from the first detection electrode and the fourth detection signal from the fourth detection electrode are input to the first input node of the differential amplifier circuit. Also, when the third switch and the second switch are turned on, the third detection signal from the third detection electrode and the second detection signal from the second detection electrode are input to the second input node of the differential amplifier circuit. This makes it possible to achieve, for example, improved detection sensitivity of physical quantities.

[0129] In this embodiment, in the operating mode, the differential amplifier circuit may receive a first sum signal of a first detection signal input from the first detection electrode via the first terminal and a fourth detection signal input from the fourth detection electrode via the fourth terminal at its first input node.The differential amplifier circuit may receive a second sum signal of a third detection signal input from the third detection electrode via the third terminal and a second detection signal input from the second detection electrode via the second terminal at its second input node, and perform differential amplification of the first sum signal and the second sum signal.

[0130] In this way, when the same physical quantity is detected, the amplitude of the signals input to the first input node and the second input node of the differential amplifier circuit becomes larger, thereby improving the detection sensitivity of the physical quantity and the S / N ratio in detecting the physical quantity.

[0131] In addition, in this embodiment, in the inspection mode, the first switch may be turned on and the second switch, the third switch, and the fourth switch may be turned off, or the third switch may be turned on and the first switch, the second switch, and the fourth switch may be turned off.

[0132] In this way, it is possible to realize an inspection mode in which only the first detection signal from the first detection electrode of the first detection arm is input to the differential amplifier circuit to measure the first detection arm, or an inspection mode in which only the third detection signal from the third detection electrode of the second detection arm is input to the differential amplifier circuit to measure the second detection arm.

[0133] In this embodiment, when the test mode is the first test mode, the first switch is turned on, the second switch, the third switch, and the fourth switch are turned off, the second input node of the differential amplifier circuit is set to a constant potential, and the differential amplifier circuit may amplify a first sensed signal input from the first detection electrode to the first input node via the first terminal and the first switch. Also, when the test mode is the second test mode, the third switch is turned on, the first switch, the second switch, and the fourth switch are turned off, and the first input node of the differential amplifier circuit is set to a constant potential, and the differential amplifier circuit may amplify a third sensed signal input from the third detection electrode to the second input node via the third terminal and the third switch.

[0134] In this way, in the first test mode, the first detection signal can be input and amplified via the first terminal and the first switch to the first input node of the differential amplifier circuit whose second input node is set to a constant potential, and in the second test mode, the third detection signal can be input and amplified via the third terminal and the third switch to the second input node of the differential amplifier circuit whose first input node is set to a constant potential.

[0135] In this embodiment, the second switch may set the second terminal to a constant potential in the first inspection mode, and the fourth switch may set the fourth terminal to a constant potential in the second inspection mode.

[0136] In this way, in the first inspection mode, the second detection electrode connected to the second terminal is set to a constant potential, thereby realizing an inspection mode for inspecting the first detection arm, and in the second inspection mode, the fourth detection electrode of the second detection arm is set to a constant potential, thereby realizing an inspection mode for inspecting the second detection arm.

[0137] In addition, in this embodiment, the amplifier circuit may include a first amplifier circuit provided between the first switch and the fourth switch and a first input node of the differential amplifier circuit, and a second amplifier circuit provided between the third switch and the second switch and a second input node of the differential amplifier circuit.

[0138] In this way, the first detection signal can be input to the first input node of the differential amplifier circuit via the first switch and the first amplifier circuit, the fourth detection signal can be input to the first input node of the differential amplifier circuit via the fourth switch and the first amplifier circuit, the third detection signal can be input to the second input node of the differential amplifier circuit via the third switch and the second amplifier circuit, and the second detection signal can be input to the second input node of the differential amplifier circuit via the second switch and the second amplifier circuit.

[0139] In this embodiment, the first switch, the second switch, the third switch, and the fourth switch may be turned on in the operation mode, and the first switch may be turned on and the second switch, the third switch, and the fourth switch may be turned off in the inspection mode, or the third switch may be turned on and the first switch, the second switch, and the fourth switch may be turned off.

[0140] In this way, in the operation mode, the first and fourth detection signals from the first and fourth detection electrodes are input to the first input node of the differential amplifier circuit, and the third and second detection signals from the third and second detection electrodes are input to the second input node of the differential amplifier circuit. Also, in the inspection mode, it is possible to input only the first detection signal from the first detection electrode of the first detection arm to the differential amplifier circuit to measure the first detection arm, or to input only the third detection signal from the third detection electrode of the second detection arm to the differential amplifier circuit to measure the second detection arm.

[0141] In this embodiment, the amplifier circuit may include a fifth switch having one end connected to a first input node of the differential amplifier circuit and the other end set to a constant potential, and a sixth switch having one end connected to a second input node of the differential amplifier circuit and the other end set to a constant potential. In the operation mode, the fifth switch and the sixth switch may be turned off, and in the test mode, either the fifth switch or the sixth switch may be turned on.

[0142] In this way, in a test mode in which a first detection signal is input to a first input node of the differential amplifier circuit for measurement, the second input node of the differential amplifier circuit is set to a constant potential, allowing the first detection signal to be measured properly, and in a test mode in which a third detection signal is input to a second input node of the differential amplifier circuit for measurement, the first input node of the differential amplifier circuit is set to a constant potential, allowing the third detection signal to be measured properly.

[0143] In addition, in this embodiment, the amplifier circuit may include a first amplifier circuit provided between the first terminal and the first switch, a second amplifier circuit provided between the second terminal and the second switch, a third amplifier circuit provided between the third terminal and the third switch, and a fourth amplifier circuit provided between the fourth terminal and the fourth switch.

[0144] In this way, the first detection signal can be input to the first input node of the differential amplifier circuit via the first amplifier circuit and the first switch, the fourth detection signal can be input to the first input node of the differential amplifier circuit via the fourth amplifier circuit and the fourth switch, the third detection signal can be input to the second input node of the differential amplifier circuit via the third amplifier circuit and the third switch, and the second detection signal can be input to the second input node of the differential amplifier circuit via the second amplifier circuit and the second switch.

[0145] In this embodiment, the first switch, the second switch, the third switch, and the fourth switch may be turned on in the operation mode, and the first switch may be turned on and the second switch, the third switch, and the fourth switch may be turned off in the inspection mode, or the third switch may be turned on and the first switch, the second switch, and the fourth switch may be turned off.

[0146] In this way, in the operation mode, the first and fourth detection signals from the first and fourth detection electrodes are input to the first input node of the differential amplifier circuit, and the third and second detection signals from the third and second detection electrodes are input to the second input node of the differential amplifier circuit. Also, in the inspection mode, it is possible to input only the first detection signal from the first detection electrode of the first detection arm to the differential amplifier circuit to measure the first detection arm, or to input only the third detection signal from the third detection electrode of the second detection arm to the differential amplifier circuit to measure the second detection arm.

[0147] In this embodiment, the amplifier circuit may include a fifth switch having one end connected to a first input node of the differential amplifier circuit and the other end set to a constant potential, and a sixth switch having one end connected to a second input node of the differential amplifier circuit and the other end set to a constant potential. In the operation mode, the fifth switch and the sixth switch may be turned off, and in the test mode, either the fifth switch or the sixth switch may be turned on.

[0148] In this way, in a test mode in which a first detection signal is input to a first input node of the differential amplifier circuit for measurement, the second input node of the differential amplifier circuit is set to a constant potential, allowing the first detection signal to be measured properly, and in a test mode in which a third detection signal is input to a second input node of the differential amplifier circuit for measurement, the first input node of the differential amplifier circuit is set to a constant potential, allowing the third detection signal to be measured properly.

[0149] Although the present embodiment has been described in detail above, those skilled in the art will readily understand that many modifications are possible without substantially departing from the novel features and advantages of the present invention. Therefore, all such modifications are intended to be within the scope of the present invention. For example, a term described at least once in the specification or drawings together with a different term having a broader or equivalent meaning may be replaced with that different term anywhere in the specification or drawings. Furthermore, the configurations of the physical quantity detection device, physical quantity detection element, and circuit device are not limited to those described in the present embodiment, and various modifications are possible. [Explanation of symbols]

[0150] 1...physical quantity detection device, 10...physical quantity detection element, 11, 12P, 12Q...vibration arm, 13, 14...driving electrode, 15A, 15B, 16A, 16B...detection electrode, 18P, 18Q, 18R, 18S...driving arm, 19P, 19Q...detection arm, 20...circuit device, 21...base, 22P, 22Q...connecting arm, 23, 24, 25A, 25B, 26A, 26B...terminal, 27P, 27Q, 27R, 27S, 28P, 28Q... weight portion, 100... drive circuit, 102... amplifier circuit, 104... gain control circuit, 106... drive signal output circuit, 108... synchronization signal output circuit, 110... detection circuit, 120, 121, 122, 123, 124, 125, 126... amplifier circuit, 128... differential amplifier circuit, 129... AC amplifier circuit, 130... synchronous detection circuit, 132... filter circuit, 134... A / D conversion circuit, 150... processing circuit, A S1, AS2, C1, C2, CD1, CD2, CE1, CE2, CE3, CE4...capacitors, DG...feedback signal, DQA...detection data, DS...drive signal, EL1A, EL1B, EL2A, EL2B...detection electrodes, NI1, NI2, NID1, NID2, NIE1 to NIE4...input nodes, NQ1, NQ2, NQD1, NQD2, NQE1 to NQE4...output nodes, OP, O PD1, OPD2, OPE1, OPE2, OPE3, OPE4... operational amplifiers, R1, R2, RD1, RD2, RE1, RE2, RE3, RE4... resistors, S1, S1A, S1B, S2, S2A, S2B... detection signals, SW1A, SW1B, SW2A, SW2B, SW5, SW6, SWD5, SWD6, SWE5, SWE6, SYC... synchronization signals, T1, T2, T3, T4, T5, T6... terminals

Claims

1. a physical quantity detection element having a plurality of detection arms, a plurality of drive arms, and a base; a circuit device that detects a physical quantity based on a plurality of detection signals from the plurality of detection arms of the physical quantity detection element; Including, The physical quantity detection element has the following detection arms: a first detection arm extending from the base, the first detection arm having a first detection electrode and a second detection electrode; a second detection arm having a third detection electrode and a fourth detection electrode and extending from the base in a direction opposite to the first detection arm; Including, The circuit device comprises: a first terminal connected to the first detection electrode; a second terminal connected to the second detection electrode; a third terminal connected to the third detection electrode; a fourth terminal connected to the fourth detection electrode; an amplifier circuit; Including, The amplifier circuit a differential amplifier circuit; a first switch provided between the first terminal and a first input node of the differential amplifier circuit; a second switch provided between the second terminal and a second input node of the differential amplifier circuit; a third switch provided between the third terminal and the second input node of the differential amplifier circuit; a fourth switch provided between the fourth terminal and the first input node of the differential amplifier circuit; A physical quantity detection device comprising:

2. 2. The physical quantity detection device according to claim 1, In the operating mode, The physical quantity detection device, wherein the first switch, the second switch, the third switch, and the fourth switch are turned on.

3. 3. The physical quantity detection device according to claim 2, In the operation mode, the differential amplifier circuit a first sum signal of a first detection signal input from the first detection electrode via the first terminal and a fourth detection signal input from the fourth detection electrode via the fourth terminal is input to the first input node, and a second sum signal of a third detection signal input from the third detection electrode via the third terminal and a second detection signal input from the second detection electrode via the second terminal is input to the second input node, and differential amplification of the first sum signal and the second sum signal is performed.

4. 2. The physical quantity detection device according to claim 1, In the inspection mode, a first switch being turned on and the second switch, the third switch, and the fourth switch being turned off, or a third switch being turned on and the first switch, the second switch, and the fourth switch being turned off;

5. 5. The physical quantity detection device according to claim 4, When the inspection mode is the first inspection mode, the first switch is turned on, and the second switch, the third switch, and the fourth switch are turned off; the differential amplifier circuit amplifies a first detection signal input from the first detection electrode to the first input node via the first terminal and the first switch, with the second input node set to a constant potential; When the inspection mode is the second inspection mode, the third switch is turned on, and the first switch, the second switch, and the fourth switch are turned off; the differential amplifier circuit amplifies a third detection signal input from the third detection electrode to the second input node via the third terminal and the third switch, while the first input node is set to a constant potential.

6. 6. The physical quantity detection device according to claim 5, In the first inspection mode, the second switch sets the second terminal to a constant potential; In the second inspection mode, The physical quantity detection device, wherein the fourth switch sets the fourth terminal to a constant potential.

7. 2. The physical quantity detection device according to claim 1, The amplifier circuit a first amplifier circuit provided between the first switch and the fourth switch and the first input node of the differential amplifier circuit; a second amplifier circuit provided between the third switch and the second switch and the second input node of the differential amplifier circuit; A physical quantity detection device comprising:

8. 8. The physical quantity detection device according to claim 7, In the operating mode, the first switch, the second switch, the third switch, and the fourth switch are turned on, In the inspection mode, a first switch being turned on and the second switch, the third switch, and the fourth switch being turned off, or a third switch being turned on and the first switch, the second switch, and the fourth switch being turned off;

9. 9. The physical quantity detection device according to claim 8, The amplifier circuit a fifth switch having one end connected to the first input node of the differential amplifier circuit and the other end set to a constant potential; a sixth switch having one end connected to the second input node of the differential amplifier circuit and the other end set to a constant potential; Including, In the operation mode, the fifth switch and the sixth switch are turned off, In the inspection mode, either the fifth switch or the sixth switch is turned on.

10. 2. The physical quantity detection device according to claim 1, The amplifier circuit a first amplifier circuit provided between the first terminal and the first switch; a second amplifier circuit provided between the second terminal and the second switch; a third amplifier circuit provided between the third terminal and the third switch; a fourth amplifier circuit provided between the fourth terminal and the fourth switch; A physical quantity detection device comprising:

11. The physical quantity detection device according to claim 10, In the operating mode, the first switch, the second switch, the third switch, and the fourth switch are turned on, In the inspection mode, a first switch being turned on and the second switch, the third switch, and the fourth switch being turned off, or a third switch being turned on and the first switch, the second switch, and the fourth switch being turned off;

12. The physical quantity detection device according to claim 11, The amplifier circuit a fifth switch having one end connected to the first input node of the differential amplifier circuit and the other end set to a constant potential; a sixth switch having one end connected to the second input node of the differential amplifier circuit and the other end set to a constant potential; Including, In the operation mode, the fifth switch and the sixth switch are turned off, In the inspection mode, either the fifth switch or the sixth switch is turned on.

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