JP4961877B2 - Angular velocity / acceleration detection sensor - Google Patents

Description

  The present invention relates to an angular velocity / acceleration detection sensor for measuring acceleration and rotational angular velocity acting on a moving body, and more particularly to an angular velocity / acceleration detection sensor having a relatively simple configuration and excellent sensitivity.

As a conventional acceleration sensor, a sensor formed of a mass part having a predetermined mass and a spring element such as a beam part supporting the mass part is known.
In such an acceleration sensor, since the stress generated in the spring element corresponds to the acceleration, the acceleration is detected by detecting the stress.
Specifically, when acceleration acts on the mass portion, the mass portion is displaced until the stress generated in the spring element is balanced with the inertial force of the mass portion. Therefore, it is possible to detect the stress generated in the spring element from this displacement and know the acceleration.
However, in such an acceleration sensor, it has been pointed out that it is necessary to use a special detection means such as a semiconductor sensor for stress detection, and a problem of stress-voltage conversion efficiency.

Therefore, the parallel beam vibrating body is connected to and supported by the support base, the parallel beam vibrating body is connected to the mass portion, means for exciting the parallel beam vibrating body, and the frequency of the parallel beam vibrating body is detected. An acceleration sensor having a configuration provided with means is also proposed (see Patent Document 1, FIG. 1 and FIG. 2).
According to the acceleration sensor having such a configuration, the beam of the parallel beam vibrating body is bent by the inertial force of the mass portion generated by the acceleration. As a result, the shape rigidity of the parallel beam vibrator changes, and the resonance frequency thereof changes. By detecting this change in frequency, acceleration is to be detected.
Since the acceleration sensor is configured as described above, the frequency of the parallel beam vibrating body is detected by a detection means such as a frequency counter, so that no special means such as a conventional semiconductor sensor is required and conversion efficiency is reduced. There is no problem.
JP-A-9-257830

However, the acceleration sensor disclosed in Patent Document 1 requires a mass portion having a relatively large shape and mass, and it is difficult to reduce the size accordingly.
In addition, there is a problem that a vibration mode that optimizes stress sensitivity corresponding to acceleration is not selected.

  An object of the present invention is to provide an angular velocity / acceleration detection sensor that can be configured in a small size, can detect acceleration with high sensitivity, and can also detect angular velocity at the same time.

  In the first aspect of the present invention, the first tuning fork type piezoelectric vibrating piece includes an oscillation circuit including at least one tuning fork type piezoelectric vibrating piece, and the first tuning fork type piezoelectric vibration provided in the oscillation circuit. A second tuning fork type piezoelectric vibrating piece as many as the piece, and a filter circuit to which a signal output from the oscillation circuit is input directly or via another circuit, and each of the first and second A tuning fork type piezoelectric vibrating piece includes a base portion made of a piezoelectric material, and at least a pair of vibrating arms formed integrally with the base portion and extending in parallel from the base portion, and is provided in the oscillation circuit and the filter circuit. The first tuning-fork type piezoelectric vibrating piece and the second tuning-fork type piezoelectric vibrating piece are arranged so that the extending directions of the vibrating arms are opposite to each other, and the oscillation occurs when acceleration is applied. Frequency of the first tuning-fork type piezoelectric resonator element of the circuit Increases, the frequency attenuation characteristic or frequency phase characteristic of the filter circuit shifts in the negative direction, and when the frequency of the first tuning-fork type piezoelectric vibrating piece of the oscillation circuit decreases, the frequency attenuation characteristic of the filter circuit or The frequency phase characteristic is configured to shift in frequency in the positive direction, and at least one tuning-fork type piezoelectric vibrating piece of the first and second tuning-fork type piezoelectric vibrating pieces has an angular velocity detection function. This is achieved by an angular velocity / acceleration detection sensor.

According to the configuration of the first invention, the tuning-fork type piezoelectric vibrating piece has a length of the vibrating arm that slightly extends or contracts when acceleration is applied in parallel to the vibrating arm. In both the first tuning-fork type piezoelectric vibrating piece provided in the circuit and the second tuning-fork type piezoelectric vibrating piece provided in the filter circuit, the extending direction of each vibrating arm coincides with the direction in which the acceleration acts. Moreover, the first tuning-fork type piezoelectric vibrating piece provided in the oscillation circuit and the second tuning-fork type piezoelectric vibrating piece provided in the filter circuit are arranged so that the directions of the vibrating arms are opposite to each other.
For this reason, if the vibrating arm of the first tuning-fork type piezoelectric vibrating piece provided in the oscillation circuit is extended, the vibrating arm of the second tuning-fork type piezoelectric vibrating piece provided in the filter circuit is slightly contracted. When the vibrating arm of the first tuning-fork type piezoelectric vibrating piece provided is contracted, the vibrating arm of the second tuning-fork type piezoelectric vibrating piece provided in the filter circuit is slightly extended.

Here, when the length of the vibrating arm of the tuning fork type piezoelectric vibrating piece is l and the width of the vibrating arm is W,
(Frequency) f = W / l ² (Formula 1).
It becomes.
That is, when the length of the vibrating arm is long, the frequency is low, and when the length of the vibrating arm is short, the frequency is high.
Therefore, when an acceleration having a component parallel to the direction of the vibrating arm is applied, the frequency (“frequency value”, hereinafter the same) of the first tuning-fork type piezoelectric vibrating piece included in the oscillation circuit increases or Decrease. The filter characteristic of the filter circuit determined by the second tuning fork type piezoelectric vibrating piece is shifted in the direction opposite to the direction in which the frequency of the first tuning fork type piezoelectric vibrating piece changes. The filter characteristics include, for example, the attenuation characteristic of the filter circuit with respect to the frequency of the signal input to the filter circuit, the phase characteristic of the filter circuit with respect to the frequency of the signal input to the filter circuit, and the like. When the acceleration acts, the filter characteristics of the filter circuit change and the frequency of the signal input to the filter circuit also changes, so that the amplitude and phase of the signal output from the filter circuit change greatly.
Therefore, the sensitivity of acceleration detection can be improved as compared with a configuration for detecting a frequency change when acceleration acts on one tuning-fork type piezoelectric vibrating piece.
In addition, the first tuning fork type piezoelectric vibrating piece and the second tuning fork type piezoelectric vibrating piece are subjected to acceleration at the same time, and the frequency change occurs simultaneously and instantaneously, so that the response is very fast.
Since the mass portion that deforms the spring element by receiving the acceleration is not required, it can be formed in a small size.
Further, since at least one tuning fork type piezoelectric vibrating piece of the first and second tuning fork type piezoelectric vibrating pieces has an angular velocity detection function, not only acceleration but also angular velocity can be detected simultaneously. .

According to a second invention, in the configuration of the first invention, a rectifier circuit that rectifies a signal output from the filter circuit and an integration circuit that integrates a signal output from the rectifier circuit are provided.
According to the configuration of the second invention, when the acceleration of the component parallel to the vibrating arm of the first tuning fork type piezoelectric vibrating piece is applied, the vibrating arm of the first tuning fork type piezoelectric vibrating piece provided in the oscillation circuit is Slightly extends. Therefore, the frequency of the tuning-fork type piezoelectric vibrating piece provided in the oscillation circuit is reduced (and the frequency of the signal output from the oscillation circuit is also reduced. Note that the first tuning-fork type piezoelectric vibrating piece is disposed in the opposite direction, When acceleration of a component parallel to the vibrating arm is applied, the frequency increases when the vibrating arm of the first tuning-fork type piezoelectric vibrating piece is slightly contracted, and so on. .
On the other hand, in the filter circuit, the attenuation amount-frequency characteristic shifts in a direction in which the attenuation amount increases due to the influence of acceleration.
Therefore, if a signal with an increased frequency from the oscillation circuit is input to the filter circuit whose attenuation amount-frequency characteristic is shifted, the attenuation amount in the filter circuit including the second tuning-fork type piezoelectric vibrating piece becomes larger. The amplitude of the signal output from the filter circuit changes greatly, and the value obtained by rectifying and integrating the amplitude changes more than the change in the frequency of the output signal of the oscillation circuit including the first tuning-fork type piezoelectric vibrating piece. Will be greatly reflected.
Therefore, according to the configuration of the second invention, it is possible to improve the sensitivity of acceleration detection based on the change of the attenuation-frequency characteristic of the tuning fork type piezoelectric vibrating piece by using the signal output from the integrating circuit. It becomes.

Further, for example, when the ambient temperature of the angular velocity sensor is high, it is as follows. That is, the frequency of the vibrating arm of the tuning fork type piezoelectric vibrating piece increases, and the attenuation amount-frequency characteristic of the tuning fork type piezoelectric vibrating piece shifts in a direction in which the attenuation amount decreases. Therefore, when the ambient temperature of the angular velocity / acceleration detection sensor is high in the configuration of the second invention, the frequency of the tuning fork type piezoelectric vibrating piece provided in the oscillation circuit is increased, and the frequency of the signal output from the oscillation circuit is also increased. .
On the other hand, in the filter circuit, the attenuation amount-frequency characteristic shifts in a direction in which the attenuation amount decreases while maintaining the graph shape of the characteristic waveform.
Accordingly, since the signal whose frequency is increased from the oscillation circuit is input to the filter circuit whose attenuation-frequency characteristic is shifted in the direction in which the attenuation decreases, the change in the attenuation in the filter circuit due to the temperature change is canceled out. A change in the amplitude of the signal output from the circuit is suppressed.
Therefore, according to the configuration of the second invention, it is possible to suppress an error that occurs in the acceleration detection value due to a change in the ambient temperature.

  According to a third invention, in the configuration of the first invention, a phase shift circuit that outputs a signal obtained by shifting the phase of the signal output from the oscillation circuit by 90 degrees to the filter circuit, and the output from the filter circuit A multiplication circuit that multiplies the signal and the signal output from the oscillation circuit, and an integration circuit that integrates the signal output from the multiplication circuit.

According to the configuration of the third invention, when acceleration is not applied, the signal output from the oscillation circuit and the signal output from the filter circuit have a phase difference of 90 degrees. When integrated, the value becomes zero.
However, in the angular velocity / acceleration detection sensor according to the third aspect of the present invention, when acceleration acts, the vibrating arm of the first tuning-fork type piezoelectric vibrating piece provided in the oscillation circuit slightly extends. Therefore, in the oscillation circuit, the frequency of the first tuning-fork type piezoelectric vibrating piece is decreased, and the phase-frequency characteristic is also shifted in the direction of increasing the phase while maintaining the graph shape representing the characteristic. For this reason, the phase (“phase value”, hereinafter the same) of the signal output from the oscillation circuit increases.

On the other hand, in the filter circuit, since the vibrating arm of the second tuning-fork type piezoelectric vibrating piece slightly contracts, the frequency of the second tuning-fork type piezoelectric vibrating piece increases, and the phase-frequency characteristic also has a graph shape representing the characteristic. The phase is shifted in the direction of decreasing while maintaining. Therefore, the phase of the signal output from the filter circuit decreases.
Therefore, in the angular velocity / acceleration detection sensor according to the third aspect of the invention, the phase of the signal output from the oscillation circuit increases while the phase of the signal output from the filter circuit decreases. The phase of the signal output from the circuit and the phase of the signal output from the filter circuit change in the direction of increasing the phase difference between them. Therefore, the value obtained by multiplying and integrating these values becomes larger compared to the case where no filter circuit is provided, and the acceleration detection sensitivity can be improved.

Further, the frequency of the vibrating arm of the tuning fork type piezoelectric vibrating piece increases as the temperature increases, and the phase-frequency characteristic of the tuning fork type piezoelectric vibrating piece shifts in a direction in which the phase increases as the temperature increases. Therefore, when the temperature of the angular velocity / acceleration detection sensor becomes high in the configuration of the third invention, the frequency of the tuning fork type piezoelectric vibrating piece provided in the oscillation circuit increases, and the phase of the signal output from the oscillation circuit increases.
On the other hand, in the filter circuit, the phase-frequency characteristic shifts in the direction of increasing the phase while maintaining the graph shape representing the characteristic.
Therefore, since the signal whose phase has increased from the oscillation circuit is input to the filter circuit whose phase-frequency characteristics are shifted in the direction of increasing the phase, the phase change in the filter circuit due to the temperature change is canceled and output from the oscillation circuit. The phase difference between the output signal and the signal output from the filter circuit remains 90 degrees.
Therefore, according to the configuration of the third invention, it is possible to prevent a value different from an accurate acceleration signal from being detected due to a change in temperature even though no acceleration is applied.

According to a fourth invention, in the configuration of any one of the first to third inventions, the second tuning-fork type piezoelectric element including the first tuning-fork type piezoelectric vibrating piece and the integrated circuit constituting the oscillation circuit, and the filter circuit. It has the package which accommodates a vibration piece, and the cover body which seals this package airtightly.
According to the configuration of the fourth invention, when detecting acceleration, the operating environment of the tuning-fork type piezoelectric vibrating piece can be stabilized by hermetically sealing the piezoelectric vibrating piece, and stable vibration can be obtained. Therefore, stable acceleration detection can be performed.

According to a fifth aspect of the invention, in the configuration of the fourth aspect of the invention, the package is formed by stacking two cavities each having a wiring board on top and bottom, and the first and second tuning forks are provided in one cavity. A type piezoelectric vibrating piece is accommodated, and the integrated circuit is accommodated in the other cavity.
According to the configuration of the fifth invention, the mounting space can be reduced by providing two cavities and accommodating the electronic components in two vertical stages.

A sixth invention is a so-called H-type package in which the two cavities are formed on the upper and lower sides of a common wiring board in the configuration of the fourth invention. The second tuning fork type piezoelectric vibrating piece is accommodated, and the integrated circuit is accommodated in the other cavity.
According to the configuration of the sixth aspect of the invention, by providing a common wiring board for each electronic component housed in the two cavities, the height dimension can be reduced and the height can be reduced.

Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings.
The embodiments described below are preferable specific examples of the present invention, and thus various technically preferable limitations are given. However, the scope of the present invention particularly limits the present invention in the following description. As long as there is no description of the effect, it is not restricted to these aspects.

(First embodiment)
FIG. 1 is a diagram showing an angular velocity / acceleration detection sensor 100 according to a first embodiment of the present invention.
Reference numeral 101 denotes a container, for example, a ceramic package. An appropriate package 101 is selected in order to stabilize the driving environment of the tuning-fork type piezoelectric vibrating piece accommodated in the interior and to eliminate various influences from the outside. A specific configuration of a suitable package or the like will be described in detail in an embodiment described later.
A first tuning fork type piezoelectric vibrating piece 111 and a second tuning fork type piezoelectric vibrating piece 121 are housed in the package 101.
As will be described later, the first tuning-fork type piezoelectric vibrating piece 111 constitutes a part of the oscillation circuit. The second tuning fork type piezoelectric vibrating piece 121 constitutes a part of the filter circuit.
Of the first and second tuning-fork type piezoelectric vibrating pieces 111 and 121, at least one tuning-fork type piezoelectric vibrating piece has an angular velocity detection function as will be described later.

The first tuning-fork type piezoelectric vibrating piece 111 and the second tuning-fork type piezoelectric vibrating piece 121 include a base 51 formed of a piezoelectric material, and at least a pair of base 51 formed integrally with the base 51 and extending in parallel with the base 51. The vibrating arms 34 and 35 are provided.
In the first tuning-fork type piezoelectric vibrating piece 111 and the second tuning-fork type piezoelectric vibrating piece 121, as shown in the drawing, the extending direction of each vibrating arm 34, 35 is coincident with the direction G in which the acceleration to be detected acts. In addition, the first tuning fork type piezoelectric vibrating piece 111 and the second tuning fork type piezoelectric vibrating piece 121 are arranged so that the directions of the vibrating arms 34 and 35 are opposite to each other.
Of the first tuning fork type piezoelectric vibrating piece 111 (211) and the second tuning fork type piezoelectric vibrating piece 121 (221), at least one tuning fork type piezoelectric vibrating piece has an angular velocity detecting function.
In this embodiment, the following description will be given by using a tuning fork type piezoelectric vibrating piece having an angular velocity detection function for the first tuning fork type piezoelectric vibrating piece 111 (211). Only the piezoelectric vibrating piece or the second tuning-fork type piezoelectric vibrating piece may be provided with an angular velocity detecting function.

2 and 3 are diagrams showing a detailed configuration example of a tuning fork type piezoelectric vibrating piece 32 (without an angular velocity detecting function) that can be used for the above-described second tuning fork type piezoelectric vibrating piece 121 (221). .
In FIG. 2, the tuning fork type piezoelectric vibrating piece 32 has, for example, a rectangular or square base 51 formed of a piezoelectric material, and a pair of vibrating arms 34 and 35 extending in the same direction with the base as a base end. .

Here, the tuning fork type piezoelectric vibrating piece 32 is formed by using, for example, a quartz substrate of a size capable of separating a plurality or a large number of tuning fork type piezoelectric vibrating pieces 32 as a piezoelectric substrate of the piezoelectric material. Yes. In this case, when cutting from a single crystal of crystal, in the orthogonal coordinate system consisting of the X, Y, and Z axes, the X axis is an electrical axis, the Y axis is a mechanical axis, and the Z axis is an optical axis. A crystal Z plate obtained by rotating and cutting in the clockwise direction around the axis in the range of 0 to 5 degrees to a predetermined thickness is used.
By etching such a crystal wafer, the outer shape of the tuning-fork type piezoelectric vibrating piece 32 of FIG. 2 is formed.

FIG. 3 is an end view taken along the line EE of FIG. As shown in FIGS. 2 and 3, long bottomed long grooves 56 and 57 extending in the length direction are formed in the respective vibrating arms 34 and 35 of the tuning fork type piezoelectric vibrating piece 32. As shown in FIG. 3, the long grooves 56 and 57 are formed on both the front and back surfaces of the vibrating arms 34 and 35.
Further, in FIG. 2, lead electrodes 52 and 53 are formed near both ends in the width direction of the end portion (lower end portion in FIG. 2) of the base portion 51 of the tuning fork type piezoelectric vibrating piece 32. The respective lead electrodes 52 and 53 are similarly formed on the back surface (not shown) of the base 51 of the tuning fork type piezoelectric vibrating piece 32.

Each of these lead electrodes 52 and 53 is a portion connected to an electrode portion on the package side described later by a conductive adhesive. As shown in FIGS. 2 and 3, the extraction electrodes 52 and 53 are integrated with excitation electrodes 54, 54, 55 and 55 provided on the upper and lower surfaces of the vibrating arms 34 and 35, respectively. It is connected. Further, as shown in FIG. 3, the respective excitation electrodes 54, 54, 55, 55 are also formed on both side surfaces of the respective vibrating arms 34, 35. The excitation electrode 54 and the excitation electrode 55 on the side surface thereof have different polarities. Further, with respect to the vibrating arm 35, the excitation electrode 55 on the upper and lower surfaces and the excitation electrode 54 on the side surface thereof have different polarities.

Here, when a driving voltage is applied to the extraction electrodes 52 and 53, a horizontal bending motion is generated so that the tip portions of the vibrating arms 34 and 35 are moved closer to and away from each other. The frequency of the alternating current generated as a piezoelectric action due to the deformation of the vibrating arms 34 and 35 due to the bending motion is as follows, where the arm width is W and the arm length is l:
(Frequency) f = W / l ² (Formula 1).
Further, the tuning fork type piezoelectric vibrating piece 32 is preferably formed to be extremely small as a whole. In FIG. 2, for example, the total length is about 1300 μm, the length of the vibrating arm is about 1040 μm, and the arm width is 40 μm. It is a very small piezoelectric vibrating piece of about 55 μm.

4 and 5 show a detailed configuration example of the tuning-fork type piezoelectric vibrating piece 32-1, which can be used for the first tuning-fork type piezoelectric vibrating piece 111 (211) described above, and has an angular velocity detection function. FIG.
In FIG. 4, a tuning fork type piezoelectric vibrating piece 32-1 includes, for example, a rectangular or square base 51 formed of a piezoelectric material, and a pair of vibrating arms 34-1 and 35-1 extending in the same direction with the base as a base end. Since the material and the like are the same as those of the piezoelectric vibrating piece 32 described with reference to FIGS. 2 and 3, the overlapping description is omitted.

One vibrating arm 34-1 of the tuning fork type piezoelectric vibrating piece 32-1 is a driving vibrating arm, and excitation electrodes 54, 54, 55, and 55 are provided as driving electrodes on the upper and lower surfaces and both side surfaces thereof. Is formed. As shown in FIG. 4, the extraction electrodes D1 and D2 extracted from the excitation electrodes 54, 54, 55, and 55 are routed to the end of the base, and can be used as drive terminals.
The other vibrating arm 35-1 of the tuning fork type piezoelectric vibrating piece 32-1 is a vibrating arm for detection. An electrode 56 is formed on the inner side surface of the vibrating arm 35-1, and is connected to the driving terminal D2. In addition, a pair of electrodes 57, 57 extending in parallel with the length direction of the vibrating arm are formed on the other side surface of the vibrating arm 35-1, and are drawn around the base 51 to detect the angular velocity detection terminal S1. , S2.

The tuning fork type piezoelectric vibrating piece 32-1 is configured as described above, and an AC voltage is applied to the drive terminals D 1 and D 2 to cause the vibrating arm 34-1 to bend and vibrate. Electric charges are generated in the detection vibrating arm 35-1 by Coriolis force, and are detected as angular velocity signals by the angular velocity detection terminals S1 and S2.
Thus, according to the tuning-fork type piezoelectric vibrating piece 32-1, the generation of the frequency based on the bending vibration and the angular velocity detection based on the angular velocity ω of FIG. 1 acting on the tuning-fork type piezoelectric vibrating piece 32-1 can be performed simultaneously. .

FIG. 6 is a block diagram showing an example of an electrical configuration of the angular velocity / acceleration detection sensor 100 of FIG.
As shown in FIG. 6, the angular velocity / acceleration detection sensor 100 according to the first embodiment includes an oscillation circuit 110, a filter circuit 120, a rectifier circuit 130 that rectifies a signal output from the filter circuit 120, And an integration circuit 140 for integrating the signal output from the rectifier circuit 130.

The oscillation circuit 110 includes, for example, a first tuning-fork type piezoelectric vibrating piece 111 having the same configuration as the tuning-fork type piezoelectric vibrating piece 32-1 described with reference to FIGS. As described above, the first tuning-fork type piezoelectric vibrating piece 111 includes a base portion made of a piezoelectric material and at least a pair of vibrating arms that are formed integrally with the base portion and extend in parallel from the base portion.
The filter circuit 120 includes a second tuning fork type piezoelectric vibrating piece 121 having the same configuration as the tuning fork type piezoelectric vibrating piece 32 described with reference to FIGS.
As described with reference to FIG. 1, the second tuning-fork type piezoelectric vibrating piece 121 has a vibrating arm that is opposite in direction to the first tuning-fork type piezoelectric vibrating piece 111 of the oscillation circuit 110. A signal output from the oscillation circuit 110 is directly input to the filter circuit 120.
The rectifier circuit 130 includes, for example, a diode 131, rectifies the output signal of the filter circuit 120, and outputs the rectified signal to the integration circuit 140.

When acceleration acts on the angular velocity / acceleration detection sensor 100 according to the first embodiment, the first tuning-fork type piezoelectric vibrating piece 111 of the oscillation circuit 110 and the second tuning-fork type piezoelectric element of the filter circuit 120 are included in the components. When a component parallel to the vibrating arm of the vibrating piece 121 is included, the following physical change occurs.
The following description relates to acceleration detection, and angular velocity velocity ω (see FIG. 1) is detected separately from acceleration from angular velocity detection terminals S1 and S2.

That is, the direction of the vibrating arm is opposite between the first tuning-fork type piezoelectric vibrating piece 111 of the oscillation circuit 110 and the second tuning-fork type piezoelectric vibrating piece 121 of the filter circuit 120. Therefore, if the length of the vibrating arm of the first tuning-fork type piezoelectric vibrating piece 111 included in the oscillation circuit 110 is slightly increased, the length of the vibrating arm of the second tuning-fork type piezoelectric vibrating piece 121 included in the filter circuit 120 is increased. Shrinks slightly. On the other hand, when the vibrating arm of the first tuning-fork type piezoelectric vibrating piece 111 included in the oscillation circuit 110 is contracted, the vibrating arm of the second tuning-fork type piezoelectric vibrating piece 121 included in the filter circuit 120 is slightly extended.

Therefore, the frequency of the first tuning-fork type piezoelectric vibrating piece 111 included in the oscillation circuit 110 is increased or decreased, while the frequency of the second tuning-fork type piezoelectric vibrating piece 121 included in the filter circuit 120 is decreased or increased (see Equation 1). ).
Therefore, in the angular velocity / acceleration detection sensor 100 according to the first embodiment, acceleration is applied, and the frequency of the first tuning-fork type piezoelectric vibrating piece 111 included in the oscillation circuit 110 and the second tuning-fork type included in the filter circuit 120. When the difference from the frequency of the piezoelectric vibrating piece 121 is taken, the absolute value thereof is larger than the frequency change of the first tuning-fork type piezoelectric vibrating piece 111 of the oscillation circuit 110.

FIG. 7 is a diagram (part 1) illustrating the attenuation-frequency characteristics of the second tuning-fork type piezoelectric vibrating piece 121 included in the filter circuit 120.
In the angular velocity / acceleration detection sensor according to the first embodiment, assuming that the frequency of the oscillation circuit 110 before the acceleration is applied is f1, the filter circuit 120 receives a signal having a frequency of f1. The amount of attenuation at 120 is A1.
Here, when an acceleration acts on the angular velocity / acceleration detection sensor according to the first embodiment in the direction of G1 shown in FIG. 1, for example, the vibration of the first tuning-fork type piezoelectric vibrating piece 111 provided in the oscillation circuit 110 Arms shrink slightly. Therefore, the frequency of the first tuning-fork type piezoelectric vibrating piece 111 included in the oscillation circuit 110 decreases, and the frequency of the signal output from the oscillation circuit 110 also decreases to f2.

On the other hand, in the filter circuit 120, as shown in FIG. 7, the attenuation amount-frequency characteristic shifts in a direction in which the attenuation amount decreases while maintaining the graph shape representing the characteristic (in FIG. 7, before the shift). Is indicated by a solid line (characteristic 1), and the shifted characteristic is indicated by a broken line (characteristic 2)).
Therefore, for example, when acceleration acts in the direction G1 shown in FIG. 1 on the angular velocity / acceleration detection sensor according to the first embodiment, a signal of the frequency f2 from the oscillation circuit 110 is input to the filter circuit 120. The amount of attenuation is A2.

  Therefore, when the acceleration is applied to the angular velocity / acceleration detection sensor according to the first embodiment, for example, in the direction of G1 shown in FIG. 1, the attenuation of the filter circuit 120 changes from A1 to A2. Therefore, in the angular velocity / acceleration detection sensor 100 according to the first embodiment, the frequency of the signal output from the oscillation circuit 110 and the attenuation-frequency characteristic of the filter circuit 120 change in a mutually opposite manner, The amplitude of the signal output from the filter circuit 120 changes greatly. Therefore, the value obtained by rectifying and integrating the signal output from the filter circuit 120 is larger than the value obtained by rectifying and integrating the change in the amplitude of the signal output from the oscillation circuit 110, and greatly reflects the change in acceleration. It will be. Therefore, according to the angular velocity / acceleration detection sensor according to the first embodiment, it is possible to improve the sensitivity of acceleration detection.

FIG. 8 is a diagram (part 2) illustrating an attenuation-frequency characteristic of the second tuning-fork type piezoelectric vibrating piece 121 included in the filter circuit 120.
Hereinafter, with reference to FIG. 8, the angular velocity / acceleration detection sensor 100 according to the first embodiment can detect an accurate acceleration without being influenced by the frequency-temperature characteristics of the tuning-fork type piezoelectric vibrating piece. Will be described.

In the angular velocity / acceleration detection sensor 100 according to the first embodiment, for example, the frequency of the first tuning-fork type piezoelectric vibrating piece 111 included in the oscillation circuit 110 is increased (increased) due to a change in environmental temperature. The frequency of the signal output from 110 also increases (becomes higher) (here, it is assumed that the frequency increases from f1 to f2).
On the other hand, in the filter circuit 120, the attenuation-frequency characteristic shifts in a direction in which the attenuation decreases in the filter circuit 120 due to a change in the environmental temperature (the characteristic before the shift is a solid line in FIG. 8). And the characteristic after the shift is indicated by a broken line).
Therefore, as shown in FIG. 8, since the frequency of the oscillation circuit 110 to f2 is input to the filter circuit 120 having the attenuation amount-frequency characteristic indicated by the broken line in FIG. 8, the attenuation amount remains unchanged at A1. Therefore, the change in the attenuation amount in the filter circuit 120 due to the temperature change is canceled, and the amplitude of the signal output from the filter circuit 120 does not change.
Therefore, according to the angular velocity / acceleration detection sensor 100 according to the first embodiment, it is possible to prevent a value different from an accurate acceleration signal from being detected due to a change in temperature although no acceleration is applied.

FIG. 9 is a time chart for explaining the operation of the circuit of FIG.
In the figure, a signal A is a signal output from the oscillation circuit 110, and the signal A is input to the filter circuit 120.
The filter circuit 120 is a band-pass filter. In the band-pass filter 120, a signal having a frequency set by the oscillation circuit 110 is attenuated by a predetermined attenuation amount corresponding to the transmission characteristics of the first tuning-fork type piezoelectric vibrating piece 111. Is output. The output signal is B.
The signal B is input to the rectifier circuit 130, rectified as indicated by C, and converted into a DC signal by the integrating circuit 140. This voltage level corresponds to acceleration.
Here, when acceleration is applied, the amplitude level of the output signal of the rectifier circuit 130 changes as indicated by C ′ in FIG.
As described above, the frequency shift due to the acceleration change can be converted into the voltage level change as the attenuation amount change.

(Second Embodiment)
Regarding the angular velocity / acceleration detection sensor 200 according to the second embodiment, the configuration described in FIGS. 1 to 3 is the same as that in the first embodiment, and therefore, a duplicate description is omitted, and the electrical difference is the same. The explanation will focus on the specific configuration.

FIG. 10 is a block diagram showing an electrical configuration of an angular velocity / acceleration detection sensor 200 according to the second embodiment of the present invention.
As shown in FIG. 10, the angular velocity / acceleration detection sensor 200 according to the second embodiment performs a filter by shifting the phase of an oscillation circuit 210, a filter circuit 220, and a signal output from the oscillation circuit 210 by 90 degrees. A phase shift circuit 230 output to the circuit 220; a multiplication circuit 240 that multiplies the signal output from the filter circuit 220 and the signal output from the oscillation circuit 210; and an integration circuit 250 that integrates the signal output from the multiplication circuit 240. And have.

The oscillation circuit 210 includes, for example, a first tuning-fork type piezoelectric vibrating piece 211 having the same configuration as that of the tuning-fork type piezoelectric vibrating piece 32-1 described with reference to FIGS. As described above, the first tuning-fork type piezoelectric vibrating piece 211 includes a base portion made of a piezoelectric material and at least a pair of vibrating arms that are formed integrally with the base portion and extend in parallel from the base portion.
The filter circuit 220 includes a second tuning-fork type piezoelectric vibrating piece 221 having the same configuration as the tuning-fork type piezoelectric vibrating piece 32 described with reference to FIGS. 2 and 3, for example.
The following description relates to acceleration detection, and angular velocity velocity ω (see FIG. 1) is detected separately from acceleration from angular velocity detection terminals S1 and S2.

As described with reference to FIG. 1, the first tuning-fork type piezoelectric vibrating piece 211 of the oscillation circuit 210 and the second tuning-fork type piezoelectric vibrating piece 221 of the filter circuit 220 are disposed in opposite directions. For this reason, when acceleration acts on the angular velocity / acceleration detection sensor 200, the vibration arms of the first tuning-fork type piezoelectric vibrating piece 211 of the oscillation circuit 210 and the second tuning-fork type piezoelectric vibrating piece 221 of the filter circuit 220 are included in the components. Can be detected as follows.
That is, if the length of the vibrating arm of the first tuning-fork type piezoelectric vibrating piece 211 provided in the oscillation circuit 210 is slightly extended, the length of the vibrating arm of the second tuning-fork type piezoelectric vibrating piece 221 provided in the filter circuit 220 is increased. Shrink slightly.
On the other hand, if the length of the vibrating arm of the first tuning-fork type piezoelectric vibrating piece 211 provided in the oscillation circuit 210 is slightly shortened, the length of the vibrating arm of the second tuning-fork type piezoelectric vibrating piece 221 provided in the filter circuit 220 is slightly reduced. The relationship extends to

Therefore, the frequency of the first tuning-fork type piezoelectric vibrating piece 211 included in the oscillation circuit 210 is increased or decreased, while the frequency of the second tuning-fork type piezoelectric vibrating piece 221 included in the filter circuit 220 is decreased or increased. Therefore, in the angular velocity / acceleration detection sensor 200 according to the second embodiment, acceleration is applied, and the frequency of the first tuning fork type piezoelectric vibrating piece 211 provided in the oscillation circuit 210 and the second tuning fork type provided in the filter circuit 221 are provided. When the difference from the frequency of the piezoelectric vibrating piece 221 is taken, the absolute value thereof is larger than the frequency change of the first tuning-fork type piezoelectric vibrating piece 211 of the oscillation circuit 210.

FIG. 11 is a diagram showing a phase difference-frequency characteristic of the first tuning-fork type piezoelectric vibrating piece 211 included in the oscillation circuit 210 and a phase difference-frequency characteristic of the second tuning-fork type piezoelectric vibrating piece 221 included in the filter circuit 220. (Part 1).
In the angular velocity / acceleration detection sensor 200 according to the second embodiment, when no acceleration is applied, the signal output from the oscillation circuit 210 and the signal output from the filter circuit 220 have a phase difference of 90 degrees. Therefore, when these are multiplied and integrated, the value becomes 0 (described later).

  However, in the angular velocity / acceleration detection sensor 200 according to the second embodiment, for example, when acceleration acts in the direction of G1 shown in FIG. 1, the vibration of the first tuning-fork type piezoelectric vibrating piece 211 provided in the oscillation circuit 210. Arms shrink slightly. Therefore, in the oscillation circuit 210, the frequency of the first tuning-fork type piezoelectric vibrating piece 211 is increased, and the phase-frequency characteristics are also reduced in phase (the phase is delayed while maintaining the graph shape representing the characteristics of FIG. 11). (In FIG. 11, the characteristic before the shift is indicated by a solid line, and the characteristic after the shift is indicated by a broken line b). For this reason, the phase of the signal output from the oscillation circuit 210 decreases.

On the other hand, in the filter circuit 220, since the vibrating arm of the second tuning-fork type piezoelectric vibrating piece 221 slightly extends, the frequency of the second tuning-fork type piezoelectric vibrating piece 221 increases, and the phase-frequency characteristic also has a graph shape. The phase is shifted in the direction in which the phase is increased (the phase is advanced) while maintaining (in FIG. 11, the characteristic before the shift is indicated by a solid line and the characteristic after the shift is indicated by a broken line a). Therefore, the phase of the signal output from the filter circuit 220 increases.
For this reason, in the angular velocity / acceleration detection sensor 200 according to the second embodiment, the phase of the signal output from the oscillation circuit 210 increases while the phase of the signal output from the filter circuit 220 decreases. Thus, the phase of the signal output from the oscillation circuit 210 and the phase of the signal output from the filter circuit 220 change in the direction of increasing the phase difference between them. Therefore, the value obtained by multiplying and integrating these values becomes larger than that in the case where the filter circuit 220 is not provided, and the acceleration detection sensitivity is improved.

FIG. 12 is a diagram showing the phase-frequency characteristics of the first tuning-fork type piezoelectric vibrating piece 211 included in the oscillation circuit 210 and the phase-frequency characteristics of the second tuning-fork type piezoelectric vibrating piece 221 included in the filter circuit 220. 2).
Hereinafter, with reference to FIG. 12, according to the angular velocity / acceleration detection sensor 200 according to the second embodiment, a value different from an accurate acceleration signal is detected due to a change in temperature even though no acceleration is applied. The point which can prevent that will be demonstrated.
When the temperature environment where the tuning fork type piezoelectric vibrating piece is placed changes, the phase of the first tuning fork type piezoelectric vibrating piece 211 of the oscillation circuit 210 and the second tuning fork type piezoelectric vibrating piece 221 of the filter circuit 220 increase. The direction is shifted by the same amount (in FIG. 12, the characteristic before the shift is indicated by a solid line, and the characteristic after the shift is indicated by a broken line c). Therefore, in the angular velocity / acceleration detection sensor according to the second embodiment, the bending vibration of the first tuning-fork type piezoelectric vibrating piece 211 of the oscillation circuit 210 and the second tuning-fork type of the filter circuit 220 before and after the temperature change. The phase difference from the bending vibration of the piezoelectric vibrating piece 221 does not change, and the phase difference between the signal output from the oscillation circuit 210 and the signal output from the filter circuit 220 remains 90 degrees.
Therefore, according to the angular velocity / acceleration detection sensor 200 according to the second embodiment, it is possible to prevent a value different from an accurate acceleration signal from being detected due to a change in temperature although no acceleration is applied.

FIG. 13 is a time chart for explaining the operation of the circuit of FIG.
In the figure, the sine wave input from the oscillation circuit 210 is shifted by 90 degrees from the rectangular wave A output from the oscillation circuit 210 described in FIG. Yes.
If the acceleration does not work, the result obtained by integrating the C signal output as a result of multiplying them by the multiplication circuit 240 by the integration circuit is zero.

Here, in FIG. 11 showing the phase-frequency characteristics, as described above, the zero point indicating the peak value which is the resonance point of the first tuning-fork type piezoelectric vibrating piece 211 of the oscillator circuit 210 is indicated by the symbol a. When the frequency shifts, the second tuning-fork type piezoelectric vibrating piece 221 of the filter circuit 220 shifts in the reverse direction so that the peak value 0 is indicated by the symbol b.
That is, the fact that the peak value is shifted means that the phase is shifted by φ, and as described above, the frequency of the peak value changes in the opposite direction and in the direction of increasing the “shift”.
For this reason, the B signal is shifted in phase like D, and the signal C that has passed through the multiplication circuit 240 becomes F. When this is integrated, h appears, and this h is detected as acceleration.

Next, regarding the angular velocity / acceleration detection sensor 100 (200) of FIG. 1, the first tuning-fork type piezoelectric vibrating piece and the integrated circuit constituting the oscillation circuit and the second tuning-fork type piezoelectric vibrating piece included in the filter circuit are accommodated. An embodiment having a package to be sealed and a lid for hermetically sealing the package will be specifically described below.

Example 1
In the first embodiment, a package is formed by stacking two cavities on top and bottom with a common wiring board 330 having conductive patterns formed on the front and back sides, and the first and second tuning fork types are formed in one of the cavities. The present invention relates to a configuration in which a piezoelectric vibrating piece is accommodated and the integrated circuit is accommodated in the other cavity.
Specifically, the piezoelectric device 300 in FIG. 14 constitutes an angular velocity / acceleration detection sensor. The piezoelectric device 300 includes a first tuning-fork type piezoelectric vibrating piece 111 (211) of the oscillation circuit 110 (210) and a second tuning-fork type piezoelectric vibrating piece 121 (221) of the filter circuit 120 (220). It is housed in a package.
14A is a plan view of the piezoelectric device 300, FIG. 14B is a schematic cross-sectional view taken along line AA in FIG. 14A, and FIG. 14C is a cross-sectional view taken along line BB in FIG. It is a schematic sectional drawing.

  In FIG. 14, a first tuning fork type piezoelectric vibrating piece 111 (211) and a second tuning fork type piezoelectric vibrating piece 121 (221) are mounted in one cavity 302 of an H type package 301, and a lid 304 is used. It is designed to be hermetically sealed. In the plan view of FIG. 14A, the lid 304 is not shown for convenience of explanation. An IC chip 305 is attached to the other cavity 303 of the H-type package 301.

  Here, the package 301 is formed by, for example, laminating a plurality of substrates formed by molding an aluminum oxide ceramic green sheet as an insulating material and then sintering. The lid 304 is formed by selecting a material such as ceramic, metal, or glass. When the lid 304 is made of metal, for example, there is an advantage that the strength is generally higher than that of other materials. As the material of the lid 304, a material having a thermal expansion coefficient close to that of the package 301 is suitable, and for example, Kovar or the like can be used. Further, in order to enable frequency adjustment after sealing the lid, the lid 304 is formed of a light transmitting material such as glass. For example, a plate body such as borosilicate glass can be used.

At one end of one cavity 302 of the package 301, for example, electrode portions 306, 307, 308, and 309 formed by nickel plating and gold plating on a tungsten metallization are provided. The electrode portions 306, 307, 308, and 309 are connected to electrodes 310, 311, 312, and 313 formed in the other cavity 303 of the package 301 through the wiring substrate 330, respectively, for example. 312 and 313 are connected to terminals of the IC chip 305 by wire bonding. The IC chip 305 is connected to mounting terminals 316 and 317 via through holes 314 and 315 provided in the package 301.
A conductive adhesive is applied on the electrode portions 306, 307, 308, and 309 of one cavity 302 of the package 301, and the first tuning-fork type piezoelectric vibrating piece 111 (211) is applied on the conductive adhesive. ) And the base of the second tuning-fork type piezoelectric vibrating piece 121 (221) are placed, and the conductive adhesive is cured. In addition, as the conductive adhesive, a synthetic resin agent as an adhesive component that exhibits a bonding force and containing conductive particles such as silver fine particles can be used. A polyimide-based conductive adhesive or the like can be used. An epoxy-based conductive adhesive is suitable for bonding and fixing the base of each tuning fork type piezoelectric vibrating piece more rigidly.

Here, both the first tuning-fork type piezoelectric vibrating piece 111 (211) and the second tuning-fork type piezoelectric vibrating piece 121 (221) have the same structure as the tuning-fork type piezoelectric vibrating piece 32 described in FIG. However, the first tuning fork type piezoelectric vibrating piece 111 (211) and the second tuning fork type piezoelectric vibrating piece 121 (221) are used for the oscillation circuit and the filter circuit in FIGS. This is to correspond to the configuration.
That is, the first tuning-fork type piezoelectric vibrating piece 111 (211) and the second tuning-fork type piezoelectric vibrating piece 121 (221) are, for example, rectangular or square bases 111a (211a) and 121a (221a) formed of a piezoelectric material. And a pair of vibrating arms 111b (211b) and 121b (221b) extending from the base portions 111a (211a) and 121a (221a).
The first tuning-fork type piezoelectric vibrating piece 111 (211) and the second tuning-fork type piezoelectric vibrating piece 121 (221) as described above are, for example, main surfaces of the vibrating arms 111b (211b) and 121b (221b), that is, the upper surface. Electrodes are formed on the lower surface, and these electrodes are routed to the extraction electrodes of the base portions 111a (211a) and 121a (221a).
When a driving voltage is applied to the extraction electrode, a horizontal bending motion is generated so that the tip portions of the vibrating arms 111b (211b) and 121b (221b) are moved closer to and away from each other.
As already described, the first tuning-fork type piezoelectric vibrating piece 111 (211) and the second tuning-fork type piezoelectric vibrating piece 121 (221) are moved to the vibrating arms 111b with respect to the direction in which the acceleration G to be detected acts. (211b) and 121b (221b) are arranged in parallel.

Here, when the acceleration acts in the G1 direction, the vibrating arm 111b (211b) of the first tuning-fork type piezoelectric vibrating piece 111 (211) extends very slightly. For this reason, the frequency by the bending vibration of the vibrating arm 111b (211b) of the first tuning-fork type piezoelectric vibrating piece 111 (211) changes high. On the other hand, the vibrating arm 121b (221b) of the second tuning-fork type piezoelectric vibrating piece 121 (221) is slightly shortened. Therefore, the vibrating arm 121b (221b) of the second tuning-fork type piezoelectric vibrating piece 121 (221). The frequency due to the flexural vibration of the plate changes low.
Similarly, in FIG. 14, when the acceleration acts in the G2 direction, the vibrating arm 111b (211b) of the first tuning-fork type piezoelectric vibrating piece 111 (211) is slightly shortened. For this reason, the frequency by the bending vibration of the vibrating arm 111b (211b) of the first tuning-fork type piezoelectric vibrating piece 111 (211) changes low. On the other hand, the vibrating arm 121b (221b) of the second tuning-fork type piezoelectric vibrating piece 121 (221) extends very slightly, and therefore, the vibrating arm 121b (221b) of the second tuning-fork type piezoelectric vibrating piece 121 (221). The frequency due to flexural vibration varies high.

According to the piezoelectric device 300 of the first embodiment described above, the first tuning-fork type piezoelectric vibrating piece 111 (211) of the oscillation circuit 110 (210) and the second tuning-fork type piezoelectric vibrating piece of the filter circuit 120 (220). 121 (221) can be accommodated in one package, and the angular velocity / acceleration detection sensor can be downsized.
In addition, by providing the common wiring board 330 for each electronic component housed in the two cavities 302 and 303, the overall height of the apparatus can be reduced and the height can be reduced.

(Example 2)
In the second embodiment, two cavities each having wiring boards 431 and 432 are stacked one above the other, and the first and second tuning-fork type piezoelectric vibrating pieces are accommodated in one cavity and the other cavity is accommodated. The present invention relates to a configuration housing an integrated circuit.
Specifically, as shown in FIG. 15, the piezoelectric device 400 also constitutes an angular velocity / acceleration detection sensor, and the piezoelectric device 400 is a first tuning-fork type piezoelectric vibrating piece 111 of the oscillation circuit 110 (210). (211) and the second tuning-fork type piezoelectric vibrating piece 121 (221) of the filter circuit 120 (220) are accommodated in one package.

15A is a plan view of the piezoelectric device 400, FIG. 15B is a schematic cross-sectional view taken along the line CC in FIG. 15A, and FIG. 15C is a line DD in FIG. It is a schematic sectional drawing.
In the example shown in FIG. 15, the first tuning fork type piezoelectric vibrating piece 111 (211) and the second tuning fork type piezoelectric vibrating piece 121 (221) are mounted in the upper cavity 402 of the package 401, and the lid 404 It is designed to be hermetically sealed. In the plan view of FIG. 15A, the lid 404 is not shown for convenience of explanation. An IC chip 405 is attached to the lower cavity 403 of the package 401.
The package 401 uses the two wiring boards 431 and 432 to form the two cavities 402 and 403, except that the package 401 is different from the first embodiment, and the material and the forming method thereof are the same as the first embodiment. Therefore, the overlapping description is omitted.
Further, the first tuning fork type piezoelectric vibrating piece 111 (211) and the second tuning fork type piezoelectric vibrating piece 121 (221) can both be of the same structure as the tuning fork type piezoelectric vibrating piece 32 described in FIG. This is also the same as in the first embodiment.

At one end of the wiring substrate 432 for constituting the upper cavity 402 of the package 401, for example, electrode portions 406, 407, 408, and 409 formed by nickel plating and gold plating on tungsten metallization are provided.
The electrode portions 406, 407, 408, and 409 are connected to electrodes 410, 411, 412, and 413 formed on the wiring substrate 431 for constituting the lower cavity 403 of the package 401, respectively. 413 is connected to electrodes 418, 419, 420, 421 through through holes 414, 415, 416, 417. The electrodes 418, 419, 420, and 421 are connected to the IC chip 405 by wire bonding. The electrodes 418, 419, 420, and 421 are connected to the mounting terminals 422 and 423 by conductive through holes (not shown).
A conductive adhesive is applied on the electrode portions 406, 407, 408, and 409 of the upper stage 402 of the package 401. On the conductive adhesive, the first tuning-fork type piezoelectric vibrating piece 111 (211) is applied. The base and the base of the second tuning-fork type piezoelectric vibrating piece 121 (221) are placed, and the conductive adhesive is cured.
Other configurations are the same as those of the first embodiment.

  According to the piezoelectric device 400 of the second embodiment described above, the first tuning-fork type piezoelectric vibrating piece 111 (211) of the oscillation circuit 110 (210) and the second tuning-fork type piezoelectric vibrating piece of the filter circuit 120 (220). 121 (221) can be accommodated in one package, and the angular velocity / acceleration detection sensor can be downsized.

The present invention is not limited to the above-described embodiment. Each configuration of each embodiment and each example can be combined or omitted as appropriate, and can be combined with other configurations not shown.
In addition, the present invention can be applied without a package as long as a tuning fork type piezoelectric vibrating piece is used. In the above-described embodiment, the tuning fork type piezoelectric vibrating piece has a box shape using ceramic. However, the present invention is not limited to such a configuration, and a storage container of a type in which a tuning fork type piezoelectric vibrating piece is bonded to a flat substrate and sealed with a cap-shaped lid may be used.

1 is a schematic plan view showing a schematic configuration of an angular velocity / acceleration detection sensor according to an embodiment of the present invention. The schematic perspective view which shows the detailed structural example of the tuning fork type piezoelectric vibrating piece used for the angular velocity / acceleration detection sensor of FIG. The EE line | wire cut end elevation of FIG. The schematic perspective view which shows the detailed structural example of the tuning fork type piezoelectric vibrating piece used for the angular velocity / acceleration detection sensor of FIG. FIG. 5 is an end view taken along line F-F in FIG. 4. The block diagram which shows the electrical structural example which concerns on 1st Embodiment of the angular velocity and acceleration detection sensor of FIG. The graph which shows the attenuation amount-frequency characteristic of an angular velocity and acceleration detection sensor provided with the structure of FIG. The graph which shows the attenuation amount-frequency characteristic of an angular velocity and acceleration detection sensor provided with the structure of FIG. 7 is a time chart in an operation example of an angular velocity / acceleration detection sensor having the configuration of FIG. The block diagram which shows the electrical structural example which concerns on 2nd Embodiment of the angular velocity and acceleration detection sensor of FIG. The graph which shows the phase-frequency characteristic of an angular velocity and acceleration detection sensor provided with the structure of FIG. The graph which shows the phase-frequency characteristic of an angular velocity and acceleration detection sensor provided with the structure of FIG. 11 is a time chart in an operation example of an angular velocity / acceleration detection sensor having the configuration of FIG. The figure which shows the piezoelectric device as Example 1 of the angular velocity and acceleration detection sensor of this invention. The figure which shows the piezoelectric device as Example 2 of the angular velocity and acceleration detection sensor of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 ... Angular velocity / acceleration detection sensor, 110 ... Oscillation circuit, 120 ... Filter circuit, 130 ... Rectification circuit, 140 ... Integration circuit, 111 ... First tuning-fork type piezoelectric vibrating piece 121: second tuning-fork type piezoelectric vibrating piece, 131: diode, 200: angular velocity / acceleration detection sensor, 210: oscillation circuit, 220: filter circuit, 230: phase shift circuit , 240 ... multiplication circuit, 250 ... integration circuit, 211 ... first tuning fork type piezoelectric vibrating piece, 221 ... second tuning fork type piezoelectric vibrating piece, 300 ... piezoelectric device, 301 · ..H-shaped package, 302 ... one cavity, 304 ... lid, 303 ... other cavity, 305 ... IC chip, 306,307,308,309 ... electrode part, 310, 311, 12, 313 ... electrodes, 314, 315 ... through holes, 316, 317 ... mounting terminals, 330 ... wiring boards, 111a (211a), 121a (221a) ... base, 111b (211b) ), 121b (221b) ... vibrating arm, 400 ... piezoelectric device, 401 ... package, 402 ... upper cavity, 404 ... lid, 403 ... lower cavity, 405 ..IC chip, 406, 407, 408, 409 ... electrode part, 410, 411, 412, 413 ... electrode, 414, 415, 416, 417 ... through hole, 422, 423 ... mounting Terminal

Claims (6)

An oscillation circuit including a first tuning-fork type piezoelectric vibrating piece ;
A second tuning-fork type piezoelectric vibrating piece, and a filter circuit for inputting a signal output from the oscillation circuit directly or via another circuit,
It said first and second sound fork type piezoelectric vibrating piece,
Group unit, and the base and formed integrally comprises at least a pair of vibrating arms extending parallel from said base portion,
And the oscillation circuit and the filter circuit wherein a provided in the first tuning-fork type piezoelectric vibrating piece, the a in the second tuning-fork type piezoelectric vibrating piece, such that the direction of extension of each of said vibrating arms in opposite directions to each other Has been placed,
When acceleration is applied, and the the frequency of the first tuning-fork type piezoelectric vibrating piece is increased, the frequency shift in the negative direction frequency attenuation characteristics or frequency phase characteristic of the filter circuit of the oscillation circuit,
When the frequency of the first tuning-fork type piezoelectric vibrating piece of the oscillating circuit is decreased, is configured to frequency attenuation characteristics or frequency phase characteristic of the filter circuit is a frequency shift in the positive direction,
Further, at least one tuning fork type piezoelectric vibrating piece of the first and second tuning fork type piezoelectric vibrating pieces has an angular velocity detecting function.   The angular velocity / acceleration detection sensor according to claim 1, further comprising: a rectifier circuit that rectifies a signal output from the filter circuit; and an integration circuit that integrates a signal output from the rectifier circuit.   A phase shift circuit that outputs a signal obtained by shifting the phase of a signal output from the oscillation circuit by 90 degrees to the filter circuit, and a signal output from the filter circuit and a signal output from the oscillation circuit. The angular velocity / acceleration detection sensor according to claim 1, further comprising a multiplication circuit and an integration circuit that integrates a signal output from the multiplication circuit. A package for accommodating said first tuning-fork type piezoelectric vibrating piece and an integrated circuit constituting the oscillator circuit, and said second tuning-fork type piezoelectric vibrating piece comprising said filter circuit, a lid for sealing the package hermetically The angular velocity / acceleration detection sensor according to claim 1, further comprising a body.   The package is formed by stacking two cavities each having a wiring board, and the first and second tuning-fork type piezoelectric vibrating pieces are accommodated in one cavity and the integrated in the other cavity. 5. The angular velocity / acceleration detection sensor according to claim 4, further comprising a circuit.   The package is a package in which two cavities are formed on both sides of a common wiring board. The first and second tuning-fork type piezoelectric vibrating reeds are accommodated in one cavity and the integrated in the other cavity. 5. The angular velocity / acceleration detection sensor according to claim 4, further comprising a circuit.

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