JP5344147B2 - Physical quantity detection device and electronic device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a physical quantity detection device for determining whether failure occurs and also specifying the failure part to some extent. <P>SOLUTION: An angular velocity detection device 1 (an example of the physical quantity detection device) includes a vibrator 100, a drive circuit 20, a detection circuit 30, voltage determination circuits 50a, 50b, and a failure determination circuit 60. The drive circuit 20 generates a drive signal and supplies it to the vibrator 100. The detection circuit 30 includes a synchronous detection circuit 35 performing detection processing to an output signal of the vibrator 100, and generates a detection signal in response to angular velocity (an example of the physical quantity) on the basis of an output signal of the synchronous detection circuit 35. The voltage determination circuits 50a, 50b each determine whether the voltage level of an input signal or an output signal of the drive circuit 20 and the voltage level of an input signal of the synchronous detection circuit 35 are normal. A signal indicating the determination result is output to the outside via an external output terminal 18. The failure determination circuit 60 determines whether or not the angular velocity detection device 1 fails on the basis of the determination results of the voltage determination circuits 50a, 50b. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a physical quantity detection device.

  Conventionally, physical quantity detection devices that detect various physical quantities are known. For example, an angular velocity detection device that detects an angular velocity as a physical quantity is known, and various electronic devices and systems that are equipped with the angular velocity detection device and perform predetermined control based on the angular velocity detected by the angular velocity detection device are widely used. ing. For example, in a car navigation system or a mobile phone, the current position is specified based on the angular velocity detected by the angular velocity detection device, and in a digital camera, camera shake correction is performed based on the angular velocity detected by the angular velocity detection device. In addition, for example, the inclination of the automobile is detected based on the angular velocity detected by the angular velocity detection device, and the inclination is controlled to be constant to prevent a rollover accident or the rollover is detected to activate the side airbag. A system has also been developed.

  In these electronic devices and systems, if the angular velocity detection device fails, incorrect control is performed. Therefore, recently, it is detected whether the angular velocity detection device has failed. Measures such as prompting repairs are being taken. In particular, it is important to quickly detect a failure of the angular velocity detection device because an error is not allowed in the control related to human life such as the prevention of rollover and the detection of rollover described above.

For example, Patent Document 1 proposes an angular velocity sensor device in which a failure determination circuit is provided inside, determines whether there is a failure, and outputs a failure determination signal.
JP-A-6-207946

  It can be repaired by judging whether the angular velocity sensor device has failed and replacing the failed angular velocity sensor device, but in order to maintain the reliability of the product, the failure location can be identified and fed back to future design development. is important.

  However, the angular velocity sensor device described in Patent Document 1 has a problem that only the presence or absence of a failure is determined, and the failure location cannot be easily specified.

  The present invention has been made in view of the above problems, and according to some aspects of the present invention, a physical quantity that can not only determine the presence / absence of a failure but also specify the failure location to some extent. A detection device can be provided.

(1) The present invention is a physical quantity detection device that detects a predetermined physical quantity, detects the physical quantity, generates a sensor element that outputs a signal according to the magnitude of the detected physical quantity, and generates a drive signal, A drive circuit that supplies the drive signal to the sensor element; and a detection circuit that performs a detection process on the output signal of the sensor element, and detects a detection signal corresponding to the physical quantity based on the output signal of the detection circuit. Based on the detection circuit to generate, the plurality of voltage determination circuits for determining whether the voltage levels of each of the plurality of predetermined signals are normal, and the determination results of the plurality of voltage determination circuits, the physical quantity detection device A failure determination circuit for determining whether or not there is a failure; and at least one external output terminal for outputting a signal indicating a determination result of the voltage determination circuit to the outside, the first voltage determination The path determines whether the voltage level of the input signal or output signal of the drive circuit is normal, and the second voltage determination circuit determines whether the voltage level of the input signal of the detection circuit is normal It is characterized by that.
In one embodiment, a sensor element that outputs a signal corresponding to the magnitude of a physical quantity, a drive circuit that generates a drive signal and supplies the drive signal to the sensor element, and an output signal of the sensor element And a detection circuit that performs detection processing, and generates a detection signal corresponding to the physical quantity based on an output signal of the detection circuit, and determines whether or not the voltage level of each of the plurality of signals is normal A plurality of voltage determination circuits; a failure determination circuit for determining whether or not the physical quantity detection device is out of order based on determination results of the plurality of voltage determination circuits; and a signal indicating the determination result of the voltage determination circuit At least one external output terminal for outputting to the outside, the first voltage determination circuit determines whether the voltage level of the input signal or output signal of the drive circuit is normal, and the second Said voltage determining circuit may be characterized in that the voltage level of the input signal of the detection circuit to determine whether normal or not.

  The predetermined physical quantity is, for example, angular velocity, acceleration, geomagnetism, pressure or the like.

  In the physical quantity detection device of the present invention, for example, the number of external output terminals equal to the number of voltage determination circuits may be provided, and a signal indicating the determination result of each voltage determination circuit may be output from each dedicated external output terminal. However, only one external output terminal for outputting a signal indicating the determination result of each voltage determination circuit to the outside may be provided.

  In the physical quantity detection device of the present invention, the first voltage determination circuit determines whether the voltage level of the input signal or the output signal of the drive circuit is normal, and the second voltage determination circuit determines whether the detection circuit included in the detection circuit It is determined whether or not the voltage level of the input signal is normal, and the failure determination circuit determines the presence or absence of a failure based on the determination result of the first voltage determination circuit and the determination result of the second voltage determination circuit.

  Therefore, according to the physical quantity detection device of the present invention, it is possible to detect a failure when there is a failure in the drive circuit or in a circuit prior to the detection circuit in the detection circuit.

  The physical quantity detection device of the present invention includes at least one external output terminal for outputting a signal indicating the determination result of the first voltage determination circuit and a signal indicating the determination result of the second voltage determination circuit to the outside. Therefore, according to the physical quantity detection device of the present invention, when there is a failure, it is possible to specify whether the drive circuit has failed or the detection circuit has failed.

  Therefore, according to the present invention, it is possible to provide a physical quantity detection device capable of not only determining the presence / absence of a failure but also specifying the failure location to some extent.

(2) physical quantity detecting apparatus of the present invention, may include a switch circuit for outputting to the external select one of a plurality of signals indicating the determination result of the voltage determining circuit.

  According to the physical quantity detection device of the present invention, since only one external output terminal is required to output a signal indicating the determination result of each voltage determination circuit to the outside, the fault location is specified even when the number of pins is severely limited. be able to.

  (3) The physical quantity detection device of the present invention includes a first switch circuit that selects one of a plurality of signals indicating the determination result of each voltage determination circuit, and the signal selected by the first switch circuit or the And a second switch circuit that selects a signal indicating a determination result of the failure determination circuit and outputs the signal to the outside via the one external output terminal.

  According to the physical quantity detection device of the present invention, one external output terminal is also used to output a signal indicating the determination result of each voltage determination circuit to the outside and to output a signal indicating the determination result of the failure determination circuit to the outside. Therefore, the presence or absence of a failure and the location of the failure can be identified even when the restriction on the number of pins is severe.

  (4) In the physical quantity detection device of the present invention, the third voltage determination circuit may determine whether or not the voltage level of the output signal of the detection circuit is normal.

  According to the physical quantity detection device of the present invention, it is possible to detect a failure of a circuit after the detection circuit in the detection circuit.

  Further, according to the physical quantity detection device of the present invention, if there is a failure, whether the drive circuit is broken, whether the circuit before the detection circuit in the detection circuit is broken, or the detection circuit in the detection circuit It is possible to specify whether a subsequent circuit has failed.

  (5) In the physical quantity detection device of the present invention, the third voltage determination circuit compares the voltage level of the output signal of the detection circuit with a first threshold when the physical quantity detection device is moving, When the physical quantity detection device is stopped, the voltage level of the output signal of the detection circuit is compared with a second threshold value different from the first threshold value, and the voltage level of the output signal of the detection circuit is determined based on the comparison result. You may make it determine whether it is normal.

  In the physical quantity detection device of the present invention, the normal voltage range of the output signal of the detection circuit is set to a different range when moving and when stopped. Therefore, for example, regarding the output signal of the detection circuit, if the normal voltage range is set to a very narrow voltage range near the zero point voltage when stopped, and the normal voltage range is widened according to the size of the detectable physical quantity when moving, The presence or absence of a failure can be determined with higher accuracy.

  (6) In the physical quantity detection device of the present invention, the third voltage determination circuit determines whether or not the voltage level of the output signal of the detection circuit is normal when the physical quantity detection device is stopped. When the physical quantity detection device is moving, it may not be determined whether or not the voltage level of the output signal of the detection circuit is normal.

  The normal voltage range of the output signal of the detection circuit during movement must be set to a wide range according to the detectable physical quantity. Therefore, even if there is a failure, it cannot be detected if the voltage level of the output signal of the detection circuit is in the normal voltage range. Further, even when the voltage level of the output signal of the detection circuit exceeds the normal voltage range, it cannot be distinguished whether a failure has occurred or a physical quantity larger than the maximum detectable value has been added. That is, it is difficult to accurately determine the presence or absence of a failure during movement, and the failure determination circuit may erroneously determine the presence or absence of a failure.

  On the other hand, when the operation is stopped, the normal voltage range of the output signal of the detection circuit is set to a narrow range including the zero point voltage, so the possibility that the failure determination circuit erroneously determines the presence or absence of a failure is low.

  According to the physical quantity detection device of the present invention, it is determined whether or not the voltage level of the output signal of the detection circuit is normal when stopped, and it is not determined whether or not the voltage level of the output signal of the detection circuit is normal when moving. The possibility that the failure determination circuit erroneously determines the presence or absence of a failure can be reduced.

  (7) The physical quantity detection device of the present invention includes an external input terminal to which a control signal indicating whether the physical quantity detection device is moving or stopped is input, and the third voltage determination circuit includes the control signal Based on the above, it may be determined whether the physical quantity detection device is moving or stopped.

  In general, a complicated circuit having a large area size is required to accurately determine whether it is moving or stopped inside the physical quantity detection device, and thus the cost of the physical quantity detection device increases.

  According to the present invention, since the control signal indicating whether it is moving or stopped is input from the outside, it is possible to suppress an increase in the cost of the physical quantity detection device. In the case of an external microcomputer, it is relatively easy to determine whether it is moving or stopped more accurately, generate a control signal, and supply it to the physical quantity detection device of the present invention.

  (8) The physical quantity detection device of the present invention includes a power supply circuit that generates an internal power supply based on an externally supplied input power supply, and the fourth voltage determination circuit includes the input power supply or the voltage level of the internal power supply. It may be determined whether or not is normal.

  According to the physical quantity detection device of the present invention, it is possible to detect an abnormality of an input power supply or a failure of a power supply circuit.

  Further, according to the physical quantity detection device of the present invention, if there is a failure, whether the drive circuit is broken, whether the circuit before the detection circuit in the detection circuit is broken, or the detection circuit in the detection circuit It is possible to specify whether the subsequent circuit is faulty or the power supply circuit is faulty (or whether the input power supply is abnormal).

(9) In the physical quantity detection device of the present invention, the physical quantity may be an angular velocity.
Further, the physical quantity detection device of the present invention may be provided in an electronic device.

  DESCRIPTION OF EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. The embodiments described below do not unduly limit the contents of the present invention described in the claims. Also, not all of the configurations described below are essential constituent requirements of the present invention.

  In the following, a physical quantity detection device (angular velocity detection device) that detects angular velocity as a physical quantity will be described as an example. However, the present invention can detect any of various physical quantities such as angular velocity, acceleration, geomagnetism, and pressure. It can be applied to devices that can.

1. Angular Velocity Detection Device of First Embodiment FIG. 1 is a diagram illustrating a configuration of an angular velocity detection device of the first embodiment.

  The angular velocity detection device 1 of the first embodiment includes a vibrator 100 and an angular velocity detection IC 10. Hereinafter, the vibrator 100 and the angular velocity detection IC 10 will be described in order.

[Vibrator]
The vibrator 100 functions as a sensor element in the present invention, detects an angular velocity, and outputs a signal corresponding to the detected angular velocity.

  FIG. 2 is a plan view of the vibrator 100. The X-axis, Y-axis, and Z-axis in FIG. 2 indicate crystal axes.

  As shown in FIG. 2, the vibrator 100 is formed of a thin plate made of a piezoelectric material such as quartz, and drive vibration arms 101a and 101b (drive vibration pieces in a broad sense) are respectively provided from two drive bases 104a and 104b. The crystal extends in the Y-axis direction. Drive electrodes 112 and 113 are formed on the side surface and the upper surface of the drive vibration arm 101a, respectively, and drive electrodes 113 and 112 are formed on the side surface and the upper surface of the drive vibration arm 101b, respectively. As shown in FIG. 1, the drive electrodes 112 and 113 are connected to the drive circuit 20 via the external output terminal 11 and the external input terminal 12 of the angular velocity detection IC 10, respectively.

  The drive bases 104a and 104b are connected to the detection base 107 via connecting arms 105a and 105b extending in the X-axis direction of the crystal, respectively. The detection vibration arm 102 (detection vibration piece in a broad sense) extends from the detection base 107 in the Y-axis direction of the crystal. Detection electrodes 114 and 115 are formed on the upper surface of the detection vibrating arm 102, and a common electrode 116 is formed on the side surface of the detection vibrating arm 102a. As shown in FIG. 1, the detection electrodes 114 and 115 are connected to the detection circuit 30 via the external input terminals 13 and 14 of the angular velocity detection IC 10, respectively. The common electrode 116 is grounded.

  When a drive signal composed of an alternating voltage / alternating current is applied between the drive electrode 112 and the drive electrode 113 of the drive vibration arms 101a and 101b, as shown in FIG. Flexurally vibrates like B.

  Here, when the vibrator 100 performs a rotational motion with the Z axis of the crystal as the rotation axis, the drive vibrating arms 101a and 101b are Coriolis in a direction perpendicular to both the direction of the bending vibration of the arrow B and the Z axis of the crystal. Gain power. As a result, the connecting arms 105a and 105b vibrate as indicated by an arrow C as shown in FIG. The detection vibrating arm 102 bends and vibrates as indicated by an arrow D in conjunction with the vibrations of the connecting arms 105a and 105b (arrow C).

  Then, an alternating voltage / alternating current in the opposite direction is generated between the detection electrodes 114 and 115 of the detection vibrating arm 102 and the common electrode 116 by the inverse piezoelectric effect generated based on these bending vibrations. As described above, the vibrator 100 detects the angular velocity component based on the Coriolis force using the Z axis of the crystal as the detection axis, and outputs a detection signal via the detection electrodes 114 and 115.

  In the configuration of FIG. 2, in order to improve the balance of the vibrator 100, the detection base 107 is disposed in the center, and the detection vibration arm 102 extends from the detection base 107 in both the + Y axis and the −Y axis. I am letting. Further, the connecting arms 105a and 105b are extended from the detection base 107 in both the + X-axis and −X-axis directions, and the drive vibrating arms 101a and 101b are extended in both the + Y-axis and −Y-axis directions from the connecting arms 105a and 105b. Is extended.

  Further, the tip of the drive vibrating arms 101a and 101b is made to have a wide wide portion 103, and a Coriolis force is increased by attaching a weight. Also, due to the weight effect, a desired resonance frequency can be obtained with a short vibrating arm. For the same reason, the front end of the detection vibrating arm 102 is a wide portion 106 and a weight is attached.

  The vibrator 100 is not limited to the above-described WT configuration, and may be a structure that serves as both a drive vibration arm and a detection vibration arm, and a piezoelectric film is formed on the drive vibration arm and the detection vibration arm. It may be the configuration.

[Angular velocity detection IC]
As shown in FIG. 1, the angular velocity detection IC 10 includes a drive circuit 20, a detection circuit 30, a power supply circuit 40, voltage determination circuits 50a, 50b, 50c, and 50d, a failure determination circuit 60, and a switch circuit 70.

  The drive circuit 20 functions as a drive circuit in the present invention, and includes an I / V conversion circuit (current / voltage conversion circuit) 21, an AC amplification circuit 22, and an amplitude adjustment circuit 23.

  When the vibrator 100 vibrates, an alternating current based on the piezoelectric effect is output from the drive electrode 113 and input to the I / V conversion circuit 21. The I / V conversion circuit 21 converts the input alternating current into an alternating voltage signal having the same frequency as the vibration frequency of the vibrator 100 and outputs it.

  The AC voltage signal output from the I / V conversion circuit 21 is input to the AC amplifier circuit 22. The AC amplifier circuit 22 amplifies and outputs the input AC voltage signal.

  The AC voltage signal output from the AC amplifier circuit 22 is input to the amplitude adjustment circuit 23. The amplitude adjustment circuit 23 controls the gain so as to hold the amplitude of the input AC voltage signal at a constant value, and outputs the AC voltage signal after gain control to the drive electrode 112 of the vibrator 100. The vibrator 100 is vibrated by an AC voltage signal (drive signal) input to the drive electrode 112.

  The detection circuit 30 functions as a detection circuit in the present invention, and includes charge amplifier circuits 31 and 32, a differential amplifier circuit 33, an AC amplifier circuit 34, a synchronous detection circuit 35, a smoothing circuit 36, a variable amplifier 37, and a filter circuit 38. It consists of

The charge amplifier circuits 31 and 32 receive detection signals (alternating currents) of opposite phases detected by the vibrator 100 via the detection electrodes 12 and 13. The charge amplifier circuits 31 and 32 convert the input detection signal (alternating current) into an alternating voltage signal centered on the reference voltage _Vref .

  The differential amplifier circuit 33 differentially amplifies the output signal of the charge amplifier circuit 31 and the output signal of the charge amplifier circuit 32. The output signal of the differential amplifier circuit 33 is further amplified by the AC amplifier circuit 34.

  The synchronous detection circuit 35 functions as a detection circuit in the present invention, and extracts an angular velocity component by synchronously detecting the output signal of the AC amplification circuit 34 based on the AC voltage signal output from the AC amplification circuit 22.

  The angular velocity component signal extracted by the synchronous detection circuit 35 is smoothed into a DC voltage signal by the smoothing circuit 36 and input to the variable amplification circuit 37.

  The variable amplifier circuit 37 amplifies (or attenuates) the output signal (DC voltage signal) of the smoothing circuit 36 with a set amplification factor (or attenuation factor) to change the angular velocity sensitivity. The signal amplified (or attenuated) by the variable amplifier circuit 37 is input to the filter circuit 38.

  The filter circuit 38 removes high-frequency noise components from the output signal of the variable amplifier circuit 37 (precisely attenuates below a predetermined level), and generates a detection signal having a polarity and a voltage level corresponding to the direction and magnitude of the angular velocity. To do. This detection signal is output from the external output terminal 16 to the outside.

  The power supply circuit 40 functions as a power supply circuit in the present invention, regulates the input power input from the power input terminal 15 to generate an internal power supply of a predetermined voltage, and drives the circuit 20, the detection circuit 30, and the voltage determination circuit 50a. , 50b, 50c, 50d, the failure determination circuit 60 and the switch circuit 70.

  The voltage determination circuit 50a functions as the first voltage determination circuit in the present invention, and receives the output signal of the drive circuit 20 (the output signal of the amplitude adjustment circuit 23 in FIG. 1), and the voltage level of the signal is normal. A voltage determination signal indicating that is output. The voltage determination circuit 50a receives an input signal of the drive circuit 20 (input signal of the I / V conversion circuit 21 in FIG. 1) and outputs a voltage determination signal indicating whether the voltage level of the signal is normal. You may do it.

  The voltage determination circuit 50b functions as the second voltage determination circuit in the present invention, and receives the input signal of the synchronous detection circuit 35 included in the detection circuit 30 (the output signal of the amplitude adjustment circuit 23 in FIG. 1). A voltage determination signal indicating whether the voltage level is normal is output.

  The voltage determination circuit 50c functions as the third voltage determination circuit in the present invention, and receives the output signal of the detection circuit 30 (the output signal of the filter circuit 38 in FIG. 1) and determines whether the voltage level of the signal is normal. Is output.

  The voltage determination circuit 50d functions as the fourth voltage determination circuit in the present invention, receives the internal power generated by the power supply circuit 40, and outputs a voltage determination signal indicating whether the voltage level of the internal power supply is normal. The voltage determination circuit 50c may receive an input power supply input to the power supply circuit 40 and output a voltage determination signal indicating whether or not the voltage level of the input power supply is normal.

  For example, the voltage determination circuits 50a, 50b, 50c, and 50d may output a voltage determination signal that is at a low level when the voltage level of each input signal is determined to be normal and is at a high level when it is determined as abnormal.

  The failure determination circuit 60 functions as a failure determination circuit in the present invention. If all the voltage determination signals of the voltage determination circuits 50a, 50b, 50c, and 50d indicate normality, it is determined that the angular velocity detection device 1 has not failed. If at least one voltage determination signal indicates abnormality, it is determined that the angular velocity detection device 1 has failed, and a failure determination signal indicating the determination result is output. For example, when the voltage determination circuits 50a, 50b, 50c, and 50d output a voltage determination signal that is low level when the voltage level of each input signal is determined to be normal and is high when it is determined as abnormal, the failure determination circuit 60 is A failure determination signal that can be realized by an OR circuit and is at a low level when there is no failure and at a high level when there is a failure is generated. The failure determination signal is output from the external output terminal 17 to the outside.

  The host CPU is connected to the external output terminal 17 during normal use. The host CPU monitors the voltage level of the external output terminal 17 to determine whether or not the angular velocity detection device 1 has failed in real time. If it is determined that, for example, a warning lamp can be displayed.

  The switch circuit 70 functions as a switch circuit in the present invention, and selects any one of the voltage determination signals of the voltage determination circuits 50a, 50b, 50c, and 50d and outputs the selected signal from the external output terminal 18 to the outside. The switch circuit 70 selects a voltage determination signal based on, for example, a set value of an internal register (not shown) or an external control signal (not shown).

  When the angular velocity detection device 1 is out of order, a failure analysis device (for example, PC) is connected to the external output terminal 18 and the voltage level of the external output terminal 18 is monitored while switching the switch circuit 70, whereby the angular velocity is detected. The failure location of the detection device 1 can be identified. In addition, the host CPU is connected to the external output terminal 18 during normal use, and the host CPU monitors the voltage level of the external output terminal 18 to identify the failure location of the angular velocity detection device 1 in real time, and more detailed according to the failure location. Such control may be performed.

  FIG. 5 is a diagram illustrating an example of signal waveforms at points A to H in FIG. 1 when an angular velocity is applied to the angular velocity detection device 1. In FIG. 5, the horizontal axis represents time, and the vertical axis represents voltage.

An AC voltage signal (drive signal) centered on the reference voltage V _ref is generated at the output (point A) of the amplitude adjustment circuit 23, and this drive signal is supplied to the drive electrode 112 of the vibrator 100, so that the vibrator 100 It vibrates, and an AC voltage signal obtained by amplifying the signal fed back from the drive electrode 113 of the vibrator 100 is generated at the output (point B) of the AC amplifier circuit 22.

  When an angular velocity about the Z axis is applied to the vibrator 100, an alternating current having the same frequency as the drive signal supplied to the drive electrode 112 is generated on the detection electrodes 114 and 115 of the vibrator 100.

  The alternating current generated in the detection electrode 114 of the vibrator 100 is converted into an alternating voltage signal by the charge amplifier circuit 31, and the output signal (point B) of the AC amplifier circuit 22 is output to the output (point C) of the charge amplifier circuit 31. A sine wave voltage signal with the same phase as that is generated.

  Since the alternating current generated at the detection electrode 115 of the vibrator 100 is in the opposite phase to the alternating current generated at the detection electrode 114, the output signal (point D) of the charge amplifier circuit 32 is output to the output signal (point D). A sine wave voltage signal having an antiphase with respect to the signal at point C) is generated.

  The output signal (point C signal) of the charge amplifier circuit 31 and the output signal (point D signal) of the charge amplifier circuit 32 are differentially amplified, and the output (point E) of the AC amplifier circuit 34 is supplied to the charge amplifier circuit 31. A sine wave voltage signal having the same phase as the sine wave voltage signal generated at the output (point C) is generated.

  The output signal of the AC amplifier circuit 34 (point E signal) is synchronously detected by the synchronous detection circuit 35 based on the output signal of the AC amplifier circuit 22 (point B signal). As a result, a signal obtained by full-wave rectifying the output signal (signal at point E) of the AC amplifier circuit 34 is generated at the output (point F) of the synchronous detection circuit 35. Note that an unnecessary alternating current having the same phase and the same frequency as that of the drive signal supplied to the drive electrode 112 is generated on the detection electrodes 114 and 115 of the vibrator 100. The unnecessary alternating current is generated by the synchronous detection circuit 35. Removed.

The output signal (point F signal) of the synchronous detection circuit 35 is smoothed by the smoothing circuit 36, and a signal having a voltage higher than the reference voltage _Vref is generated at the output (point G) of the smoothing circuit 36. As a result, A signal having a voltage higher than the reference voltage _Vref is also generated at the output (point H) of the filter circuit 38, that is, the output of the detection circuit 30.

When an angular velocity in the direction opposite to that in FIG. 5 is applied to the angular velocity detection device 1, both the output signal of the charge amplifier circuit 31 (signal at point C) and the output signal of the charge amplifier circuit 32 (signal at point D) are both. The waveform is inverted by 180 °. Therefore, a signal having a voltage lower than the reference voltage V _ref is generated at the output of the detection circuit 30.

  In this way, the detection circuit 30 can detect the angular velocity. The detection signal output from the detection circuit 30 is proportional to the magnitude of Coriolis force (angular velocity), and its polarity is determined by the direction of rotation. The device can calculate the angular velocity applied to the angular velocity detection device 1 based on the detection signal.

  FIG. 6 is a diagram illustrating an example of the circuit configuration of the voltage determination circuits 50a, 50b, and 50c.

  As shown in FIG. 6, the voltage determination circuits 50a, 50b, and 50c in the present embodiment are configured to include a rectifier circuit 52, a smoothing circuit 54, and a comparison circuit 56.

  The rectifier circuit 52 in this embodiment includes a resistor 521, a resistor 522, a resistor 523, a differential amplifier 524, a diode 525, a diode 526, and a resistor 527.

The first terminal of the first terminal and the resistor 522 of the resistor 521 is connected to the input terminal _{I 1.} The output signal of the driving circuit 20 shown in FIG. 1 the input terminal I _1, the output signal of the input signal or the detection circuit 30 of the synchronous detection circuit 35 is input.

The resistance values of the resistor 521 and the resistor 523 are equal, and the second terminal of the resistor 521, the first terminal of the resistor 523, and the non-inverting input terminal (+ input terminal) of the differential amplifier 524 are connected to each other. The second terminal of the resistor 523 and the output terminal of the differential amplifier 524 are connected. The second terminal of the resistor 522, the inverting input terminal (−input terminal) of the differential amplifier 524, and the anode terminal of the diode 525 are connected to each other. The cathode terminal of the diode 525, the cathode terminal of the diode 526, and the first terminal of the resistor 527 are connected to each other, and the reference voltage V _ref is supplied to the anode terminal of the diode 526. A second terminal of the resistor 527 is grounded.

Since the diode 526 flows forward current and the forward voltage drop of the pn junction and _{V d,} the voltage of the cathode terminal of the diode 526 becomes _V ref -V _d. Therefore, the voltage at the cathode terminal of the diode 525 is also V _ref −V _d .

When the voltage V _in of the input terminal I ₁ is higher than the reference voltage V _ref , that is, when V _in = V _ref + ΔV, a forward current flows through the diode 525, so the voltage at the anode terminal of the diode 525 is V _ref become. Accordingly, the voltages at the inverting input terminal (−input terminal) and the non-inverting input terminal (+ input terminal) of the differential amplifier 524 are also V _ref . Then, since the resistance values of the resistor 521 and the resistor 523 are equal, the voltage of the output terminal of the differential amplifier 524 is V _ref −ΔV, that is, the voltage V _in (= V _ref + ΔV) of the input terminal I ₁ is the reference voltage V _ref. The voltage is turned back with respect to.

On the other hand, when the voltage at the input terminal I ₁ is lower than the reference voltage V _ref , that is, when V _in = V _ref −ΔV, no current flows through the diode 525, so the voltage at the anode terminal of the diode 525 is the input terminal I ₁ equal to the voltage V _in (= V _ref −ΔV). Therefore, the voltages of the inverting input terminal (−input terminal) and the non-inverting input terminal (+ input terminal) of the differential amplifier 524 are also V _in (= V _ref −ΔV). Therefore, the voltage at the output terminal of the differential amplifier 524 becomes equal to the voltage V _in (= V _ref −ΔV) at the input terminal I ₁ .

That is, the rectifier circuit 52 rectifies the signal supplied to the input terminal I ₁ to a low voltage signal than the reference voltage V _ref.

  The smoothing circuit 54 in this embodiment includes a resistor 541 and a capacitor 542. The first terminal of the resistor 541 is connected to the output terminal of the differential amplifier 544, the second terminal of the resistor 541 and the first terminal of the capacitor 542 are connected, and the second terminal of the capacitor 542 is grounded. That is, an integrating circuit is configured by the resistor 541 and the capacitor 542, and the output signal of the rectifier circuit 52 is smoothed by the smoothing circuit 54 to become a DC signal.

  The comparison circuit 56 in this embodiment includes differential amplifiers 561 and 563, variable resistors 562 and 564, and an OR circuit 565.

  The non-inverting input terminal (+ input terminal) of the differential amplifier 561 and the inverting input terminal (−input terminal) of the differential amplifier 563 are connected to the second terminal of the resistor 541 and the first terminal of the capacitor 542. The output terminal of the amplifier 561 and the output terminal of the differential amplifier 561 are connected to the first input terminal and the second input terminal of the OR circuit 565, respectively. The variable resistors 562 and 564 can be realized by, for example, a circuit in which a plurality of resistors are connected in series between a power supply and a ground, and an inverting input terminal (−input) of the differential amplifier 561 according to a selection signal (not shown). Terminal) and the non-inverting input terminal (+ input terminal) of the differential amplifier 563 are each connected to one of taps between the resistors.

  The differential amplifiers 561 and 563 output a high level voltage to the output terminal when the voltage of the non-inverting input terminal (+ input terminal) is higher than the voltage of the inverting input terminal (−input terminal), and the non-inverting input terminal When the voltage at the (+ input terminal) is lower than that at the inverting input terminal (−input terminal), a low level voltage is output to the output terminal. A voltage obtained by resistance-dividing the power supply voltage according to the selection signal is supplied to the inverting input terminal (−input terminal) of the differential amplifier 561 as the upper limit threshold voltage, and the voltage level of the output signal of the smoothing circuit 54 is the upper limit threshold voltage. To be compared. The non-inverting input terminal (+ input terminal) of the differential amplifier 563 is supplied with a voltage obtained by resistance-dividing the power supply voltage according to the selection signal as a lower limit threshold voltage, and the voltage level of the output signal of the smoothing circuit 54 is lower limit threshold voltage. Compared with In the present embodiment, the upper threshold voltage and the lower threshold voltage can be changed by changing the resistance values of the variable resistors 562 and 564, but the upper threshold voltage and the lower threshold voltage are fixed. You may make it do.

If the voltage level of the output signal of the smoothing circuit 54 is between the lower threshold voltage and the upper threshold voltage, the output signal of the OR circuit 565 becomes low level, and the voltage level of the output signal of the smoothing circuit 54 becomes lower limit threshold voltage. If the voltage is not between the upper threshold voltages, the output signal of the OR circuit 565 becomes a high level. The output terminal of the OR circuit 565 is connected to the output terminal O _1, and the output signal of the OR circuit 565 is supplied to the switch circuit 70 and the failure determination circuit 60 shown in FIG. 1 via the output terminal O ₁ . The

  As described above, the voltage determination circuits 50a, 50b, and 50c of the present embodiment are respectively the output signal of the drive circuit 20 (point A signal) and the input signal of the synchronous detection circuit 35 (point E signal) shown in FIG. ) If the integrated value (power) of the voltage level of the AC voltage signal generated in () is within a predetermined range, it is determined to be normal and a low level voltage is output. Output.

  FIG. 7 is a diagram illustrating an example of a circuit configuration of the voltage determination circuit 50d.

  As shown in FIG. 7, the voltage determination circuit 50 d in the present embodiment includes only the comparison circuit 56. Although the internal power generated by the power supply circuit 40 shown in FIG. 1 is supplied to the voltage determination circuit 50d, since the internal power supply is a constant DC voltage signal, unlike the voltage determination circuits 50a, 50b, and 50c, a rectifier circuit 52 and the smoothing circuit 54 are unnecessary.

  The voltage determination circuit 50d of the present embodiment determines that the internal power supply generated by the power supply circuit 40 shown in FIG. 1 is normal if the voltage level is within a predetermined range and outputs a low level voltage. Outputs a high-level voltage based on an abnormality.

[Procedure for identifying the fault location]
FIG. 8 is a flowchart illustrating an example of a procedure for identifying a failure location of the angular velocity detection device 1. In the flowchart of FIG. 8, it is assumed that the voltage determination circuits 50a, 50b, 50c, 50d, and the switch circuit 70 are not broken down. Note that the voltage determination circuits 50a, 50b, 50c, and 50d output a voltage determination signal that is low when the voltage level of each input signal is determined to be normal and is high when the voltage level is determined to be abnormal. Further, the failure determination circuit 60 outputs a failure determination signal that is at a low level when there is no failure and at a high level when there is a failure. Hereinafter, the flowchart of FIG. 8 will be described.

  First, the angular velocity detection device 1 is rotated at a predetermined angular velocity or stopped until all subsequent processes are completed (step S10).

  Next, the external output terminal 17 is monitored, and if the external output terminal 17 is at a low level (No in step S20), it is determined that there is no failure (step S30), and the process ends without performing the process of identifying the failure location. To do.

  If the external output terminal 17 is at a high level (Yes in step S20), it is determined that there is a failure (step S40).

  If there is a failure, first, the switch circuit 70 is switched to connect the output of the voltage determination circuit 50d and the external output terminal 18 (step S50). As a result, the voltage determination signal output from the voltage determination circuit 50d is output from the external output terminal 18.

  If the external output terminal 18 is at a high level (Yes in step S60), it is determined that the input power supply voltage input from the power input terminal 15 is abnormal or that the power supply circuit 40 is faulty ( Step S70), the fault location specifying process is terminated.

  If the external output terminal 18 is at a low level (No in step S60), the switch circuit 70 is switched to connect the output of the voltage determination circuit 50a and the external output terminal 18 (step S80). As a result, the voltage determination signal output from the voltage determination circuit 50 a is output from the external output terminal 18.

  If the external output terminal 18 is at a high level (Yes in step S90), the drive unit of the vibrator 100 has failed, or the I / V conversion circuit 21, the AC amplification circuit 22, and the amplitude of the drive circuit 20 It is determined that any one of the adjustment circuits 23 has failed (step S100), and the failure point specifying process ends.

  If the external output terminal 18 is at a low level (No in step S90), the switch circuit 70 is switched to connect the output of the voltage determination circuit 50b and the external output terminal 18 (step S110). As a result, the voltage determination signal output from the voltage determination circuit 50 b is output from the external output terminal 18.

  If the external output terminal 18 is at a high level (Yes in step S120), the detection unit of the vibrator 100 has failed, or the charge amplifier circuits 31, 32, the differential amplifier circuit 33, the detection circuit 30, It is determined that one of the AC amplifier circuits 34 has failed (step S130), and the failure point identification processing is terminated.

  If the external output terminal 18 is at a low level (No in step S120), the switch circuit 70 is switched to connect the output of the voltage determination circuit 50c and the external output terminal 18 (step S140). As a result, the voltage determination signal output from the voltage determination circuit 50 c is output from the external output terminal 18.

  If the external output terminal 18 is at a high level (Yes in step S150), it is determined that any one of the synchronous detection circuit 35, the smoothing circuit 36, the variable amplification circuit 37, and the filter circuit 38 of the detection circuit 30 has failed. (Step S160), and the fault location specifying process is terminated.

  If the external output terminal 18 is at a low level (in the case of No in step S150), it is determined that the failure determination circuit 60 has failed (step S170), and the failure location specifying process ends.

[Effect of the first embodiment]
In the angular velocity detection device of the first embodiment, the voltage determination circuit 50a determines whether or not the voltage level of the output signal of the drive circuit 20 (amplitude adjustment circuit 23) is normal, and the voltage determination circuit 50b inputs the synchronous detection circuit 35. It is determined whether the voltage level of the signal is normal, the voltage determination circuit 50c determines whether the voltage level of the output signal of the detection circuit 30 (filter circuit 38) is normal, and the voltage determination circuit 50c detects the detection circuit 30 ( It is determined whether the voltage level of the output signal of the filter circuit 38) is normal, and the voltage determination circuit 50d determines whether the voltage level of the output signal of the power supply circuit 40 is normal. Then, the failure determination circuit 60 determines the presence or absence of a failure based on the output signals of the voltage determination circuits 50a, 50b, 50c, and 50d.

  Since the failure determination signal output from the failure determination circuit 60 is output to the outside from the external output terminal 17, according to the angular velocity detection device of the first embodiment, if the voltage level of the external output terminal 17 is monitored, whether or not there is a failure Can be easily determined from the outside.

  Furthermore, if the switch circuit 70 is switched, the voltage determination signals output from the voltage determination circuits 50a, 50b, 50c, and 50d are output to the outside from the external output terminal 18. Therefore, according to the angular velocity detection device of the first embodiment. If the voltage level of the external output terminal 17 is monitored, it can be determined to some extent from the outside which of the drive circuit 20, the detection circuit 30, and the power supply circuit 40 has failed.

  Further, according to the angular velocity detection device of the first embodiment, only one external output terminal for outputting each voltage determination signal output from the voltage determination circuits 50a, 50b, 50c, and 50d to the outside is sufficient, so that the angular velocity detection IC 10 can be used. Even when the number of pins is severely limited, it is possible to identify a failure location.

[Modification]
9 and 10 are diagrams showing a configuration of a modification of the first embodiment.

  In the modification shown in FIG. 9, the angular velocity detection IC 10 does not include the switch circuit 70 and the external output terminal 18, but includes external output terminals 18a, 18b, 18c, and 18d instead. The external output terminals 18a, 18b, 18c, and 18d output voltage determination signals output from the voltage determination circuits 50a, 50b, 50c, and 50d, respectively.

  The modification of FIG. 9 can be applied when the restriction on the number of pins of the angular velocity detection IC 10 is loose. 9, there is a possibility that the chip area can be reduced by the amount of the switch circuit 70, and each voltage determination signal output by the voltage determination circuits 50a, 50b, 50c, and 50d by switching with the switch. Therefore, it is possible to identify the failure location more easily and in a short time.

  In the modification shown in FIG. 10, the angular velocity detection IC 10 includes a switch circuit 80. The switch circuit 80 functions as the second switch circuit in the present invention, and the voltage determination selected by the failure determination signal output from the failure determination circuit 60 and the switch circuit 70 (functioning as the second switch circuit in the present invention). One of the signals is selected and output from the external output terminal 17 to the outside. The switch circuit 80 selects a failure determination signal or a voltage determination signal based on, for example, a set value of an internal register (not shown) or an external control signal (not shown).

  During normal operation, the switch circuit 80 is set so as to select a failure determination signal, and an external device (for example, a host CPU) connected to the external output terminals 16 and 17 is determined as a failure determination output from the external output terminal 17. Based on the voltage level of the signal, it is determined whether or not the angular velocity detection device 1 has failed. If it is determined that there is a failure, for example, a warning lamp can be turned on.

  On the other hand, at the time of failure analysis, the switch circuit 80 is set to select a failure determination signal, and an external device (for example, PC) connected to the external output terminals 16 and 17 By monitoring the voltage level of the voltage determination signal output from the terminal 17 in order, the failure location of the angular velocity detection device 1 can be specified.

  As described above, the angular velocity detection IC 10 in the modification of FIG. 10 also serves as the external output terminal 17 in order to output a failure determination signal or a voltage determination signal to the outside. Therefore, the modification of FIG. 10 is particularly effective when the restriction on the number of pins of the angular velocity detection IC 10 is severe.

2. Angular Velocity Detection Device of Second Embodiment Since the angular velocity is applied when the angular velocity detection device 1 is moved, the range in which the angular velocity can be detected needs to be a normal voltage range. Therefore, in the first embodiment, for example, in the voltage determination circuit 50c, the normal voltage range of the output signal of the detection circuit 30 is set to a wide range. Therefore, a failure in which the output signal of the detection circuit 30 sticks to the power supply voltage can be detected.

On the other hand, when the stop angular velocity detection device 1 is the angular velocity is zero, the output signal of the detection circuit 30 becomes a signal having a constant voltage of the reference voltage V _ref is ideally narrow around the reference voltage V _ref range Is the normal voltage range. Therefore, in the first embodiment, when the normal voltage range of the output signal of the detection circuit 30 is set to be wide in accordance with the movement, the voltage at the time of stopping (zero point voltage) has an offset with respect to the reference voltage V _ref . Such a failure cannot be detected.

  Therefore, in the second embodiment, in the voltage determination circuit 50c, the normal voltage range of the output signal of the detection circuit 30 at the time of stopping and moving is set to a different range.

  FIG. 11 is a diagram illustrating a configuration of an angular velocity detection device according to the second embodiment. In FIG. 11, the same components as those in FIG.

  In the angular velocity detection device 1 of the second embodiment, an external input terminal 19 is added to the configuration of the first embodiment shown in FIG. 1, and a control signal 192 is input from the external input terminal 19 to the voltage determination circuit 50c. Is done. The control signal 192 is a signal indicating whether the angular velocity detection device 1 is moving or stopped, and is, for example, a high level when moving and a low level when stopping.

  Based on the control signal 192, the voltage determination circuit 50c in the second embodiment supplies the upper limit threshold voltage supplied to the inverting input terminal (−input terminal) of the differential amplifier 561 shown in FIG. The lower threshold voltage supplied to the input terminal (+ input terminal) is changed. That is, the voltage determination circuit 50c is configured so that, for example, the normal voltage range at the time of movement is different from the normal voltage range at the time of stop so that the normal voltage range at the time of movement differs from the normal voltage range at the time of stop in the output signal of the detection circuit 30. Can be wide.

By setting in this way, for example, when the voltage level of the output signal of the detection circuit 30 does not become a value very close to the reference voltage V _ref even when stopped due to a failure, the output signal of the detection circuit 30 is not moved when moving. Although the normal voltage range is wide, failure detection cannot be performed. However, if the normal voltage range of the output signal of the detection circuit 30 at the time of stop is set to a very narrow range centered on the reference voltage V _ref , the failure can be detected at the time of stop. It becomes like this.

  Since other configurations in the second embodiment are the same as those in the first embodiment, description thereof is omitted.

  It should be noted that the normal voltage range of the output signal of the detection circuit 30 during movement can be determined based on the maximum value of the angular velocity to be detected and the sensitivity voltage.

For example, when the angular velocity detection device 1 is used for prevention of rollover or rollover detection of an automobile, if the angular velocity at which the vehicle rolls over is about ± 300 dps (degree per second) and the sensitivity voltage of the angular velocity detection device 1 is 6 mV / dps, the automobile The voltage level of the output signal of the detection circuit 30 at the time of rollover is the reference voltage V _ref ± 1.8V. Actually, if it is rare that the angular velocity exceeds about ± 250 dps, the normal voltage range of the output signal of the detection circuit 30 at the time of movement is the reference voltage V _ref −1.5 V or more and the reference voltage V _ref +1.5 V or less. It can be.

However, if the reference voltage V _ref −1.5 V or higher and the reference voltage V _ref +1.5 V or lower is set as the normal voltage range, the failure determination circuit when the detection circuit 30 has not failed even when traveling at a high speed on a sharp curve. There is a possibility that control such as turning on a warning lamp by outputting a failure determination signal indicating a failure from 60 may be performed. Therefore, in order to output a failure determination signal indicating a failure from the failure determination circuit 60 only when the detection circuit 30 has failed reliably, the detection circuit 30 during movement is also considered in consideration of the influence of noise. of the normal voltage range of the output signal, for example, it is preferably less than or equal to the reference voltage _V ref -2.0 V or more reference voltage _V ref + 2.0V.

On the other hand, the normal voltage range of the output signal of the detection circuit 30 at the time of stop may be a narrow range centered on the reference voltage _Vref .

For example, the normal voltage range of the output signal of the detection circuit 30 at the time of stop can be set to the reference voltage V _ref −0.5 V or more and the reference voltage V _ref +0.5 V or less in consideration of the influence of noise. Furthermore, if emphasis is placed on detecting a failure as soon as possible, the normal voltage range of the output signal of the detection circuit 30 at the time of stop is set to a reference voltage V _ref −0.3 V or more and a reference voltage V _ref +0.3 V or less. It is desirable.

  As described above, in the angular velocity detection device of the second embodiment, the output signal of the detection circuit 30 has a very narrow voltage range near the zero point voltage as a normal voltage range when stopped, and a detectable angular velocity when moving. Accordingly, the presence or absence of a failure can be determined with higher accuracy by widening the normal voltage range according to the above.

3. Angular Velocity Detection Device of Third Embodiment The configuration of the angular velocity detection device of the third embodiment is the same as that of the angular velocity detection device 1 of the second embodiment shown in FIG. 11, but the configuration of the voltage determination circuit 50c is different.

  As described above, when the angular velocity detection device 1 moves, the normal voltage range of the output signal of the detection circuit 30 is generally set to a wide range. Even if the angular velocity detection device 1 is out of order, the failure cannot be detected if the voltage level of the output signal of the detection circuit 30 is in the normal voltage range. In general, even when the voltage level of the output signal of the detection circuit 30 exceeds the normal voltage range (for example, when the output signal of the detection circuit 30 sticks to the power supply voltage), the angular velocity detection is performed. It cannot be distinguished whether the device 1 has failed or whether an angular velocity greater than the maximum detectable angular velocity has been applied. That is, it is difficult to accurately determine the presence or absence of a failure when the angular velocity detection device 1 is moving, and the failure determination circuit 60 may erroneously determine the presence or absence of a failure.

  On the other hand, since the normal voltage range of the output signal of the detection circuit 30 is generally set to a narrow voltage range including the zero point voltage when the angular velocity detection device 1 is stopped, the failure determination circuit 60 erroneously determines whether there is a failure or not. The possibility of doing is low.

  Therefore, it may be realistic to determine whether or not the voltage level of the output signal of the detection circuit 30 is normal only when the angular velocity detection device 1 is stopped. Therefore, the voltage determination circuit 50c in the third embodiment determines whether the angular velocity detection device 1 is moving or stopped based on the control signal 192 input from the external input terminal 19, and the detection circuit 30 at the time of stop. It is determined whether or not the voltage level of the output signal is normal, and it is not determined whether or not the voltage level of the output signal of the detection circuit 30 is normal when stopped.

FIG. 12 shows a configuration example of the voltage determination circuit 50c in the third embodiment. The voltage determination circuit 50c in the third embodiment has an input terminal I ₂ , an inverting circuit 566, and an AND circuit 567 added to the voltage determination circuit 50c in the first embodiment shown in FIG. Are the same.

Input terminal of the inverter circuit 566 is connected to the input terminal I _2, the output terminal of the inverter circuit 566 is connected to the second input terminal of the AND circuit. The first input terminal of the AND circuit 567 is connected to the output terminal of the OR circuit 565, the output terminal of the AND circuit 567 is connected to the output terminal _{O 1.} The output signal of the AND circuit 567 is supplied to the switch circuit 70 and the failure determination circuit 60 shown in FIG. 11 via the output terminal O ₁ .

The inverting circuit 566, control signal 192 is input through the input terminal _{I 2.} The control signal 192 is at a high level when the angular velocity detection device 1 is moving, and is at a low level when it is stopped.

  Accordingly, when the angular velocity detection device 1 is moved, the output of the inverting circuit 566 becomes low level, and as a result, the output of the AND circuit 567 also becomes low level. That is, the voltage determination circuit 50c always outputs a voltage determination signal indicating that the voltage level of the output signal of the detection circuit 30 is normal when the angular velocity detection device 1 is moved. Therefore, when the angular velocity detection device 1 moves, the voltage determination signal output from the voltage determination circuit 50 c does not affect the failure determination by the failure determination circuit 60.

  On the other hand, when the angular velocity detection device 1 is stopped, the output of the inverting circuit 566 becomes high level, and as a result, the output signal of the OR circuit 565 propagates to the output of the AND circuit 567. That is, when the angular velocity detection device 1 is stopped, the voltage determination circuit 50c determines whether or not the voltage level of the output signal of the detection circuit 30 is normal, and outputs a voltage determination signal. Therefore, when the angular velocity detection device 1 is stopped, the voltage determination signal output from the voltage determination circuit 50 c is used for failure determination by the failure determination circuit 60.

  As described above, according to the angular velocity detection device of the third embodiment, it is determined whether or not the voltage level of the output signal of the detection circuit 30 is normal when stopped, and the voltage level of the output signal of the detection circuit 30 is determined when moving. Since it is not determined whether it is normal or not, the possibility that the failure determination circuit 60 erroneously determines the presence or absence of a failure can be reduced.

  The angular velocity detection devices of the first to third embodiments include a digital camera, a mobile phone, a portable information terminal, a car navigation system, a device for performing posture detection and posture control of a moving body such as an automobile and a robot, a virtual It can be incorporated into various electronic devices and systems such as a head mounted display used for reality, a tracker for detecting the posture angle of the head, a game machine using a 3D game pad, and the like.

  In addition, this invention is not limited to this embodiment, A various deformation | transformation implementation is possible within the range of the summary of this invention.

  For example, the voltage determination circuits 50a, 50b, and 50c may be realized with the same circuit configuration as the voltage determination circuit 50d shown in FIG.

  The present invention includes configurations that are substantially the same as the configurations described in the embodiments (for example, configurations that have the same functions, methods, and results, or configurations that have the same objects and effects). In addition, the invention includes a configuration in which a non-essential part of the configuration described in the embodiment is replaced. In addition, the present invention includes a configuration that exhibits the same operational effects as the configuration described in the embodiment or a configuration that can achieve the same object. Further, the invention includes a configuration in which a known technique is added to the configuration described in the embodiment.

The figure which shows the structure of the angular velocity detection apparatus of 1st Embodiment. The top view of a vibrator. The figure for demonstrating operation | movement of a vibrator | oscillator. The figure for demonstrating operation | movement of a vibrator | oscillator. The figure which shows an example of the signal waveform when the angular velocity is added to the angular velocity detection apparatus. The figure which shows an example of the circuit structure of a voltage determination circuit. The figure which shows an example of the circuit structure of a voltage determination circuit. The flowchart figure which shows an example of the procedure which pinpoints the failure location of an angular velocity detection apparatus. The figure which shows the structure of the modification of 1st Embodiment. The figure which shows the structure of the other modification of 1st Embodiment. The figure which shows the structure of the angular velocity detection apparatus of 2nd Embodiment and 3rd Embodiment. The figure which shows the structural example of the voltage determination circuit in 3rd Embodiment.

DESCRIPTION OF SYMBOLS 1 Angular velocity detection apparatus, 10 Angular velocity detection IC, 20 Drive circuit, 21 I / V conversion circuit (current voltage conversion circuit), 22 AC amplifier circuit, 23 Amplitude adjustment circuit, 30 Detection circuit, 31 Charge amplifier circuit, 32 Charge amplifier Circuit, 33 differential amplifier circuit, 34 AC amplifier circuit, 35 synchronous detection circuit, 36 smoothing circuit, 37 variable amplifier, 38 filter circuit, 40 power supply circuit, 50a to 50d voltage determination circuit, 52 rectifier circuit, 54 smoothing circuit, 56 Comparison circuit, 60 failure determination circuit, 70 switch circuit, 80 switch circuit, 100 vibrator, 101a drive vibration arm, 101b drive vibration arm, 102 detection vibration arm, 103 wide portion, 104a drive base, 104b drive base, 105a Connecting arm, 105b Connecting arm, 106 Wide part, 107 Detection base 112 driving electrode, 113 driving electrode, 114 sensing electrode, 115 sensing electrode, 116 common electrode, 192 control signal, 521 resistance, 522 resistance, 523 resistance, 524 differential amplifier, 525 diode, 526 diode, 527 resistance, 541 resistance, 542 Capacitor, 561 Differential amplifier, 562 Variable resistor, 563 Differential amplifier, 564 Variable resistor, 565 OR circuit, 566 Inversion circuit, 567 AND circuit

Claims (8)

A sensor element that outputs a signal according to the size of the physical quantity;
A drive circuit that generates a drive signal and supplies the drive signal to the sensor element;
A detection circuit that performs detection processing on the output signal of the sensor element, and generates a detection signal corresponding to the physical quantity based on the output signal of the detection circuit;
A plurality of voltage determination circuits for determining whether or not each voltage level of the plurality of signals is normal;
A failure determination circuit that determines whether or not the physical quantity detection device has failed based on the determination results of the plurality of voltage determination circuits;
And external output terminal for outputting a signal indicating the determination result of the voltage determining circuit to the outside,
A switch circuit that selects one of a plurality of signals indicating a determination result of each of the voltage determination circuits and outputs the selected signal to the outside via the external output terminal ;
The first voltage determination circuit includes:
Determining whether the voltage level of at least one of the input signal and the output signal of the drive circuit is normal;
The second voltage determination circuit includes:
A physical quantity detection device for determining whether or not a voltage level of an input signal of the detection circuit is normal. Oite to claim 1,
The third voltage determination circuit includes:
A physical quantity detection device for determining whether or not a voltage level of an output signal of the detection circuit is normal. In claim 2 ,
The third voltage determination circuit includes:
When the physical quantity detection device is moving, the voltage level of the output signal of the detection circuit is compared with the first threshold value, and when the physical quantity detection device is stopped, the voltage level of the output signal of the detection circuit is set. A physical quantity detection device that compares with a second threshold different from the first threshold and determines whether or not the voltage level of the output signal of the detection circuit is normal based on the comparison result. In claim 2 ,
The third voltage determination circuit includes:
When the physical quantity detection device is stopped, it is determined whether or not the voltage level of the output signal of the detection circuit is normal. When the physical quantity detection device is moving, the voltage level of the output signal of the detection circuit is A physical quantity detection device characterized by not determining whether or not it is normal. In claim 3 or 4 ,
Including an external input terminal to which a control signal indicating whether the physical quantity detection device is moving or stopped is input;
The third voltage determination circuit includes:
A physical quantity detection device that determines whether the physical quantity detection device is moving or stopped based on the control signal. In any one of Claims 1 thru | or 5 ,
Including a power supply circuit for generating an internal power supply based on an externally supplied input power supply,
The fourth voltage determination circuit determines whether the voltage level of the input power supply or the internal power supply is normal. In any one of Claims 1 thru | or 6 ,
The physical quantity detection device is characterized in that the physical quantity is an angular velocity. An electronic apparatus characterized by comprising a physical quantity detecting device according to any one of claims 1 to 7.

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