JP2012242260A - Physical quantity sensor and electronic apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a small-sized physical quantity sensor that secures amplitude displacement amount of mass sections and has high detection sensitivity.SOLUTION: The physical quantity sensor 1 includes: a sensor surface 3 on a board 2; two mass sections 4 arranged horizontally in a first axis direction of the sensor surface 3; rotary axes 8 which are provided in the two mass sections 4 and extend in a second axis (Y-axis) direction vertical to a first axis (X-axis) on the sensor surface 3; a drive section 5 for rotationally vibrating the two mass sections 4 around the rotary axes 8 in opposite phases using a first frequency; a force transmission section 6 for transmitting force received from each of the two mass sections 4; and a detection section 7 which is provided in the force transmission section 6 to detect displacement amount according to the transmitted force as an electric signal. In the physical quantity sensor 1, Coriolis force generated in the mass sections 4 according to the angular velocity around a third axis vertical to the sensor surface 3 is detected in the detection section 7.

Description

  The present invention relates to a physical quantity sensor and an electronic device using the same.

2. Description of the Related Art In recent years, angular velocity sensors that detect angular velocities are often used for camera shake correction of imaging devices such as digital cameras and attitude control of mobile navigation systems such as vehicles using GPS signals. Further, an angular velocity sensor that can detect an angular velocity in the sensor surface is also known (see, for example, Patent Document 1).
The sensor described in Patent Document 1 includes a frame parallel to the sensor surface, two mass parts arranged in the lateral direction, a coupling part inside the frame and connected to the two mass parts, and an actuator for driving And a converter for detection, and the connecting part is configured to restrict the mass part to move in the vertical direction.

US Pat. No. 6,892,575

  However, in the configuration described in Patent Document 1, it is difficult to ensure the amplitude displacement amount of the mass part. When the amplitude displacement amount of the mass part is small, the detection sensitivity of the angular velocity sensor is lowered. In addition, in order to obtain a necessary amplitude displacement amount, a drive unit having a high drive capability is required, resulting in an increase in the size of the sensor.

  An object of the present invention is to provide a small physical quantity sensor that secures an amplitude displacement amount of a mass part and has high detection sensitivity, and an electronic apparatus using the same.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following forms or application examples.

  [Application Example 1] A physical quantity sensor according to this application example includes a substrate, two mass parts arranged above the substrate in the direction of the first axis, and each of the two mass parts. The first torsion spring provided in the direction of the second axis perpendicular to the first axis in plan view, and the two mass parts rotating in the opposite directions with the first torsion spring as an axis A drive unit that is connected to each of the two mass units via the first torsion spring, the force transmission unit that transmits the force received from the mass unit, and the force transmission unit, And a detector that detects a displacement amount corresponding to the electric signal as an electrical signal.

  According to this application example, since the two mass portions are rotated and vibrated using the first torsion spring as the rotation axis, a sufficient amplitude displacement amount can be ensured with a small driving power. When an angular velocity is input around the first axis (X axis) when the two mass parts rotate and vibrate in the third axis (Z axis) direction around the rotation axis, the two mass parts The force transmission unit is displaced in the second axis (Y-axis) direction by the Coriolis force received by the sensor, and the angular velocity around the first axis can be detected using the detection unit provided in the force transmission unit. In the case of the angular velocity sensor, if the amplitude displacement can be obtained, the amplitude velocity can be set fast, so that a minute Coriolis force can be detected (high sensitivity). Therefore, a high-performance physical quantity sensor with high detection sensitivity can be provided.

  Application Example 2 In the physical quantity sensor according to the application example, the drive unit is fixed to the substrate via a second torsion spring provided in the direction of the second axis, and the second torsion spring is used as an axis. It is preferable to vibrate.

  According to this application example, the drive unit includes a rotation shaft with the second torsion spring as an axis, and includes, for example, at least one arm that allows rotational vibration around the rotation shaft and restricts other movements. Since it is fixed to the substrate via, it can move only around the rotation axis. By transmitting this rotational vibration to two adjacent mass parts via the connecting part, it is possible to efficiently convert a small amount of drive energy into vibration energy of the two mass parts. Therefore, a highly efficient physical quantity sensor with low power consumption can be provided.

  Application Example 3 In the physical quantity sensor according to the application example described above, it is preferable that the driving unit is rotated and vibrated by an electrostatic force between an electrode provided on the driving unit and an electrode provided on the substrate.

  According to this application example, for example, a positive voltage is applied to the electrode provided in the drive unit, and a negative voltage is applied to the electrode of the substrate facing the electrode of the drive unit. It swings like a seesaw, so that each of the mass parts can be rotated and vibrated in opposite directions.

  Application Example 4 In the physical quantity sensor according to the application example described above, it is preferable that each of the two mass units is connected to the driving unit via a connection unit.

  According to this application example, the driving force from the driving unit can be efficiently transmitted by causing the two mass units to be adjacent to each other and mechanically connected by the driving unit and the connector. Furthermore, two mass parts, a drive part, and a connector can be installed in a small area range, and a physical quantity sensor can be reduced in size.

  Application Example 5 In the physical quantity sensor according to the application example described above, it is preferable that each of the force transmission units is provided at least at a part around the mass unit.

  According to this application example, by providing the force transmission unit at least at a part of the periphery of the drive unit and the two mass units, space can be saved by connecting the detection unit to the outside of the force transmission unit. By setting it as such a form, the area of the mass part inside a force transmission part can be taken large, ie, the mass of a mass part can be enlarged. Since the Coriolis force generated by the angular velocity is proportional to the mass, the sensitivity can be increased by increasing the mass. Moreover, the force transmission part does not need to be integrated, and may be composed of a plurality of mass bodies and mechanical springs. By dividing the force transmission unit into a plurality of mass bodies and mechanical springs, it is possible to efficiently transmit force necessary for Coriolis detection and to suppress transmission of other unnecessary force and vibration.

  Application Example 6 In the physical quantity sensor according to the application example, it is preferable that the first torsion spring is provided on each of the opposing side surfaces of the mass unit on the second axis.

  According to this application example, the first torsion spring provided in the mass part is provided on each of the opposing side surfaces, and the mass part is formed by the plurality of torsion springs connecting the mass part and the force transmission unit. It is possible to efficiently rotate and vibrate. In particular, when the rotating shaft is formed by two torsion springs, the Q value of the rotational vibration can be increased, and vibration with less energy loss can be given to the mass portion. The higher the Q value of vibration, the greater the displacement of the mass part can be obtained with less drive energy, leading to higher sensitivity of the physical quantity sensor. Therefore, a high-performance physical quantity sensor can be obtained.

  Application Example 7 In the physical quantity sensor according to the application example, it is preferable that the first torsion spring is provided in parallel with the second torsion spring.

  According to this application example, the vibration energy generated by the drive unit can be efficiently converted into the vibration energy of the mass unit by making the rotation axis provided in the mass unit parallel to the rotation axis of the drive unit. Thereby, the power consumption of the drive unit can be reduced.

  Application Example 8 In the physical quantity sensor according to the application example described above, it is preferable that the two mass parts are arranged at positions symmetrical to each other with respect to the second torsion spring.

According to this application example, by disposing the mass portion in a symmetrical position with respect to the second torsion spring, it is possible to equalize the amount of displacement of rotational vibration between one mass portion and the other mass portion. The accuracy of physical quantity detection can be improved.
Application Example 9 In the physical quantity sensor according to the application example described above, the detection unit is provided at a position where the detection unit is provided on the substrate and the movable electrode unit provided on the substrate and is opposed to the movement electrode unit. It is preferable to include a fixed electrode portion.

  According to this application example, when an angular velocity is input around the first axis (X axis) and the force transmission unit is displaced in the direction of the second axis (Y axis) by the Coriolis force, the movable electrode unit provided in the force transmission unit And the capacitance between the fixed electrode portion provided on the substrate and the fixed electrode portion provided at a position facing the movable electrode portion is changed, whereby the angular velocity around the first axis can be detected. it can.

  Application Example 10 An electronic apparatus according to this application example is characterized in that the physical quantity sensor described in any one of Application Examples 1 to 9 is mounted.

  According to this application example, it is possible to provide an electronic device with high sensitivity and reduced size.

1 is a schematic plan view according to a first embodiment of the present invention. 1 is a schematic plan view according to a first embodiment of the present invention. It is the model perspective view (a) explaining the operation | movement of 1st Embodiment of this invention, and a model side view schematic diagram (b). It is a schematic plan view which concerns on 2nd Embodiment of this invention. It is the model perspective view (a) explaining the operation | movement of 2nd Embodiment of this invention, and a model side schematic diagram (b). It is a schematic plan view which concerns on the 1st modification of the detection part of this invention. It is a schematic plan view which concerns on the 2nd modification of the detection part of this invention. It is a schematic plan view which concerns on 3rd Embodiment of this invention. It is a perspective view of an electronic device (notebook type personal computer) provided with the physical quantity sensor of the present invention. It is a perspective view of an electronic device (cellular phone) including the physical quantity sensor of the present invention. It is a perspective view of an electronic device (digital still camera) provided with the physical quantity sensor of the present invention.

  Hereinafter, a physical quantity sensor of the present invention and an electronic apparatus using the same will be described in detail based on preferred embodiments shown in the accompanying drawings. In the following drawings, the scale of each layer and each member is made different from the actual scale so that each layer and each member can be recognized.

FIG. 1 is a schematic plan view according to the first embodiment of the physical quantity sensor of the present invention, and FIG. 2 is a detailed schematic plan view according to the first embodiment of the physical quantity sensor of the present invention. FIG. 3 is a schematic perspective view (a) and a schematic side view (b) for explaining the operation of the physical quantity sensor shown in FIG.
In each figure, for convenience of explanation, an X axis, a Y axis, and a Z axis are illustrated as three axes orthogonal to each other. In the following, the direction parallel to the X axis (first axis) is the “X axis direction”, the direction parallel to the Y axis (second axis) is the Y axis direction, and the direction is parallel to the Z axis (third axis). Is referred to as “Z-axis direction”. Hereinafter, the physical quantity sensor of the present invention will be described in detail by applying it to an angular velocity sensor that detects an angular velocity around the X axis (first axis). The springs are represented by lines for convenience.

(Embodiment 1)
As shown in FIG. 1, the physical quantity sensor 1 is formed on a sensor surface 3 parallel to the substrate 2, and has a pair of mass parts (two mass parts) 4 disposed to face each other in the X-axis direction. The rotation shafts J1 and J2 formed by the first torsion spring 8 provided in the mass part 4 and parallel to the Y axis, and the two mass parts 4 opposed to each other are rotated in the opposite phases by using the first frequency. It is connected to the drive unit 5 that rotates around J1 and J2, the force transmission unit 6 that transmits the force generated in the mass unit 4 via the rotating shaft 8, and the force transmission unit 6, depending on the received force And a detector 7 for detecting the amount of displacement as an electrical signal. Further, the drive unit 5 has a rotation axis J3 composed of the second torsion spring 9 so that the rotation motion can be transmitted to the mass unit 4 via the connection portion 10 when performing the rotation motion around the rotation axis J3. The structure is taken.

  According to such a physical quantity sensor 1, the mass portion 4 is rotated and oscillated around the rotation axes J <b> 1 and J <b> 2. In the case of the angular velocity sensor, the amplitude velocity is increased simultaneously with the amplitude displacement, so that the detection of the Coriolis force corresponding thereto is facilitated (high sensitivity). Furthermore, taking advantage of the fact that the positional relationship between the rotary shafts J1 and J2 and the connecting portion 10 can be freely set, the maximum and optimum amplitude displacement amount can be set with a small driving force using the lever principle. If it can be driven with a small driving force, the size of the physical quantity sensor 1 can be reduced. Therefore, the small physical quantity sensor 1 having high detection sensitivity can be provided.

(Vibration structure)
Hereinafter, the physical quantity sensor 1 will be described more specifically with reference to FIG. A sensor surface 3 parallel to the substrate 2 is provided, and a physical quantity sensor 1 is formed. The physical quantity sensor 1 includes a first mass unit 210 and a second mass unit 310 that are parallel to the sensor surface 3 and arranged to face each other in the X-axis direction. The two mass portions 210 and 310 are installed adjacent to each other, and a rotation shaft J1 composed of torsion springs 219 and 220 and a rotation shaft J2 composed of torsion springs 319 and 320 are formed on the respective mass portions 210 and 310. ing. That is, the two mass portions 210 and 310 have a structure capable of rotating about the rotation axes J1 and J2, respectively.

  Further, the drive unit 5 is installed in an intermediate region between the first mass unit 210 and the second mass unit 310. The drive unit 5 is suspended by torsion springs 40 and 41 mechanically connected to substrate fixing units (anchors) 30 and 31 fixed to the substrate 2, respectively. Further, the drive unit 5 performs a seesaw motion around the rotation axis J3 formed by the torsion springs 40 and 41 by alternately applying a voltage to the electrodes 260 and 360 provided on the substrate 2 at a predetermined frequency. Designed to do. Although not shown, a driving lower electrode is formed on the substrate 2 at a position facing the electrodes 260 and 360. The movement can be transmitted to the first mass part 210 via the first connection part 221 and to the second mass part 310 via the second connection part 321. That is, by using this drive unit 5, the first mass unit 210 and the second mass unit 310 can be moved in opposite phases using a predetermined frequency.

(Detection system structure)
On the other hand, the first force transmission unit 211 and the second force transmission unit 212 provided adjacent to the first mass unit 210 are fixed to a substrate (anchor) by plate springs 253 and 254 and plate springs 251 and 252, respectively. 242, 31 and the substrate fixing portions (anchors) 241, 30. At this time, the leaf springs 251 to 254 are all designed to be hard in the X-axis direction and soft in the Y-axis direction. Further, the first force transmission unit 211 and the second force transmission unit 212 are mechanically connected to the first mass unit 210 by torsion springs 219 and 220. The torsion springs 219 and 220 are designed to be soft around the rotation axis J1 and hard in the Y-axis direction. When the torsion springs 219 and 220 receive the force F1 in the Y-axis direction, the force F1 is transmitted as the first force. It is structured to transmit to the part 211 and the second force transmission part 212.

  The force F1 is soft in the X-axis direction and hard in the Y-axis direction by the leaf springs 222 and 223, and the third force transmission unit 213 from the first force transmission unit 211 and the second force transmission unit 212. Is transmitted to. The third force transmission unit 213 is connected to a first detection unit 218 that detects a displacement amount corresponding to the force F1 as an electrical signal. More specifically, the first detection unit 218 is connected to the third force transmission unit 213 and connected to the first electrodes 215 of the first detection comb teeth movable in the Y-axis direction and to different potentials fixed to the substrate 2. In addition, a plurality of comb-tooth units 214 constituted by the second electrode 216 and the third electrode 217 of the first detection comb-tooth are provided.

  The amount of displacement corresponding to the force F1 changes the capacitance between the first electrode 215 and the other two electrodes (second electrode 216, third electrode 217). Can be detected. However, even if the third force transmission unit 213 and the first electrode 215 are displaced in the X-axis direction, the first detection unit 218 does not generate a difference in capacitance and therefore does not generate a detection signal. That is, the displacement amount only in the Y-axis direction can be detected. In addition, it can be said that the 1st force transmission part 211, the 2nd force transmission part 212, and the 3rd force transmission part 213 form the flame | frame surrounding the 1st mass part 210 in appearance.

  Further, the fourth force transmission unit 311 and the fifth force transmission unit 312 provided adjacent to the second mass unit 310 are fixed to the substrate (anchor) by leaf springs 353 and 354 and leaf springs 351 and 352, respectively. 344, 31 and the substrate fixing portion (anchors) 343, 30. At this time, the leaf springs 353, 354, 351, and 352 are all designed to be hard in the X-axis direction and soft in the Y-axis direction. Further, the fourth force transmission unit 311 and the fifth force transmission unit 312 are mechanically connected to the second mass unit 310 by torsion springs 319 and 320. The torsion springs 319 and 320 are designed to be soft around the rotation axis J2 and hard in the Y-axis direction. When the torsion springs 319 and 320 receive the force F2 in the Y-axis direction, the force F2 is transmitted as it is to the fourth force. It is structured to transmit to the part 311 and the fifth force transmission part 312.

  The force F2 is soft in the X-axis direction and hard in the Y-axis direction by the leaf springs 322 and 323 that are designed from the fourth force transmission unit 311 and the fifth force transmission unit 312 to the sixth force transmission unit 313. Is transmitted to. The sixth force transmission unit 313 is connected to a second detection unit 318 that detects a displacement amount corresponding to the force F2 as an electrical signal. More specifically, the second detection unit 318 is connected to the sixth force transmission unit 313 and connected to the first electrode 315 of the second detection comb tooth movable in the Y-axis direction and to different potentials fixed to the substrate 2. In addition, a plurality of comb-teeth units 314 each including the second electrode 316 and the third electrode 317 of the second detection comb-teeth are provided.

  The amount of displacement corresponding to the force F2 changes the capacitance between the first electrode 315 and the other two electrodes (second electrode 316 and third electrode 317). Can be detected. However, even in the second detection unit 318, even if the sixth force transmission unit 313 and the first electrode 315 are displaced in the X-axis direction, a difference in capacitance change does not occur, and thus no detection signal is generated. That is, the displacement amount only in the Y-axis direction can be detected as in the first detection unit 218. It can be said that the fourth force transmission unit 311, the fifth force transmission unit 312, and the sixth force transmission unit 313 apparently form a frame surrounding the second mass unit 310.

  According to such a configuration, the physical quantity sensor 1 converts the Coriolis force generated according to the angular velocity around the X axis into the forces F1 and F2, and the electrostatic capacitance in the first detection unit 218 and the second detection unit 318. It can be detected as a change. Hereinafter, the operation principle will be described in detail with reference to FIG.

(Operating principle)
3A and 3B are schematic diagrams for explaining the operation principle of the physical quantity sensor 1. FIG. 3A is a schematic perspective view, and FIG. 3B is a schematic side view. The drive unit 5 provided in the physical quantity sensor 1 is rotated and oscillated around the rotation axis J3 by applying a drive voltage to the drive lower electrode formed on the substrate 2 (not shown). That is, the drive unit 5 performs a seesaw motion on the sensor surface with the rotation axis J3 as a fulcrum. Since the drive unit 5 and the first mass unit 210 and the second mass unit 310 are physically connected via the first connection unit 221 and the second connection unit 321, the movement of the drive unit 5 is the first mass. Is transmitted to the unit 210 and the second mass unit 310.

  When the movement of the driving unit 5 is transmitted to the two mass units 210 and 310, the mass transmission units 6 and 310 are torsion springs (not shown) that coincide with the rotation axes J1 and J2, respectively. Therefore, rotational vibration is performed around the respective rotation axes J1 and J2. At this time, the first mass unit 210 and the second mass unit 310 increase the amplitude displacement amount of the rotational vibration by utilizing the principle of the lever, based on the positional relationship between the connection portions 221 and 321 and the rotation axes J1 and J2. It can be taken (see FIG. 3B).

  When an angular velocity around the X axis is input to the first mass unit 210 and the second mass unit 310 that are performing such rotation vibration, the Coriolis force (see FIG. 5) depends on the rotation direction (V1, V2). 2 forces F1 and F2). The generated Coriolis forces F1 and F2 are transmitted to the force transmission unit 6 by a torsion spring (not shown). The amount of displacement corresponding to the transmitted force is detected by the detection unit 7. In this way, the angular velocity with respect to the in-plane axis on which the physical quantity sensor 1 is formed, for example, the X axis or the Y axis can be measured.

(Embodiment 2)
FIG. 4 is a schematic plan view according to the second embodiment of the present invention. Note that the same reference numerals as those in the first embodiment are assigned to members that overlap those in the first embodiment. A sensor surface 3 parallel to the substrate 2 is provided, and a physical quantity sensor 11 is formed. The physical quantity sensor 11 includes a first mass unit 410 and a second mass unit 510 that are parallel to the sensor surface 3 and arranged to face each other in the X-axis direction. The two mass portions 410 and 510 are installed adjacent to each other, and a rotary shaft J1 including torsion springs 419 and 420 and a rotation shaft J2 including torsion springs 519 and 520 are formed on the respective mass portions 410 and 510. ing. That is, the two mass portions 410 and 510 have a structure capable of rotating about the rotation axes J1 and J2, respectively.

  In addition, the drive unit 51 is installed in an intermediate region between the first mass unit 410 and the second mass unit 510. The driving portion 51 is suspended by torsion springs 40 and 41 mechanically connected to substrate fixing portions (anchors) 30 and 31 fixed to the substrate 2, respectively. Further, the drive unit 51 alternately applies a voltage to the electrodes 260 and 360 provided on the substrate 2 at a predetermined frequency to perform a seesaw motion around the rotation axis J3 formed by the torsion springs 40 and 41. Designed to do. Although not shown, a driving lower electrode is formed on the substrate 2 at a position facing the electrodes 260 and 360. The movement can be transmitted to the first mass part 410 via the first connection part 421 and the second connection part 521 to the second mass part 510. That is, by using this drive unit 51, the first mass unit 410 and the second mass unit 510 can be moved in opposite phases using a predetermined frequency.

  The drive unit 51 is formed smaller than the drive unit 5 of the first embodiment. Instead, the first connecting portion 421 with the first mass portion 410 and the second connecting portion 521 with the second mass portion 510 are rotated with the rotation axis J1 including the torsion springs 419 and 420 and the torsion springs 519 and 520. It is provided inside the axis J2, that is, close to the drive unit 51.

A first detection unit 418 that detects a displacement amount corresponding to the force as an electrical signal is connected to the first force transmission unit 211 and the second force transmission unit 212 of the physical quantity sensor 11. More specifically, the first detection unit 418 is connected to the first force transmission unit 211 and the second force transmission unit 212, and the first electrode 415 of the first detection comb tooth as a movable electrode unit movable in the Y-axis direction. A plurality of comb-tooth units 414 composed of a second electrode 416 of a first detection comb tooth and a third electrode 417 as fixed electrode portions fixed to the substrate 2 and connected to different potentials. Yes.
The amount of displacement corresponding to the force F1 changes the capacitance between the first electrode 415 and the other two electrodes (second electrode 416, third electrode 417). Can be detected. In addition, it can be said that the 3rd force transmission part 213 is connected to the 1st force transmission part 211 and the 2nd force transmission part 212, and forms the frame which surrounds the 1st mass part 410 with three appearances.

A second detection unit 518 that detects a displacement amount corresponding to the force F2 as an electric signal is connected to the fourth force transmission unit 311 and the fifth force transmission unit 312 of the physical quantity sensor 11. More specifically, the second detection unit 518 is connected to the fourth force transmission unit 311 and the fifth force transmission unit 312, and is fixed to the substrate 2 and the first electrode 515 of the second detection comb tooth movable in the Y-axis direction. A plurality of comb-teeth units 514 each having a second electrode 516 and a third electrode 517 of the second detection comb tooth connected to different potentials are provided.
The amount of displacement corresponding to the force F2 changes the capacitance between the first electrode 515 and the other two electrodes (the second electrode 516 and the third electrode 517). Can be detected. In addition, it can be said that the 6th force transmission part 313 is connected to the 4th force transmission part 311 and the 5th force transmission part 312, and forms the flame | frame which surrounds the 2nd mass part 510 with three appearances.

(Operating principle)
5A and 5B are schematic diagrams for explaining the operation principle of the physical quantity sensor 11, wherein FIG. 5A is a schematic perspective view, and FIG. 5B is a schematic side view. The drive unit 51 provided in the physical quantity sensor 11 rotates and vibrates around the rotation axis J3 by applying a drive voltage to the drive lower electrode formed on the substrate 2 (not shown). That is, the drive unit 51 performs a seesaw motion on the sensor surface with the rotation axis J3 as a fulcrum. Since the drive unit 51 and the first mass unit 410 and the second mass unit 510 are physically connected via the first connection unit 421 and the second connection unit 521, the movement of the drive unit 51 is the first mass. Transmitted to the portion 410 and the second mass portion 510.

  When the movement of the drive unit 51 is transmitted to the two mass units 410 and 510, the mass units 410 and 510 are torsion springs (not shown) that coincide with the rotation axes J1 and J2, respectively. Therefore, rotational vibration is performed around the respective rotation axes J1 and J2. At this time, the first mass part 410 and the second mass part 510 take the amplitude displacement amount of the rotational vibration larger from the positional relationship between the connection parts 421 and 521 and the rotation axes J1 and J2 using the principle of the lever. (See FIG. 5 (b)).

  When an angular velocity around the X axis is input to the first mass unit 410 and the second mass unit 510 that perform such rotation vibration, the Coriolis force F1, F1 is determined according to the rotation direction (V1, V2). F2 is generated. The generated Coriolis forces F1 and F2 are transmitted to the force transmission unit 6 by a torsion spring (not shown). The amount of displacement corresponding to the transmitted force is detected by the detection unit 7. In this way, the angular velocity with respect to an axis in the surface of the physical quantity sensor 11, for example, the X axis or the Y axis can be measured.

  In the second embodiment shown in FIGS. 4 and 5, the drive unit 51 is formed smaller than the drive unit 5 of the first embodiment. Using the principle, the amplitude displacement amount of each of the mass portions 410 and 510 can be set freely. Furthermore, since the detection unit 7 is extended in the Y-axis direction with respect to the force transmission unit 6 of the physical quantity sensor 11, the occupied width in the X-axis direction can be reduced.

(Modification 1)
FIG. 6 is a schematic plan view illustrating a modification of the detection unit in the physical quantity sensor according to the first embodiment. More specifically, in the physical quantity sensor 1, the force transmission unit 6 includes a first force transmission unit 211, a second force transmission unit 212, and a third force transmission unit 213. The detection unit 7 includes a first detection unit 618 connected to the third force transmission unit 213 among the three force transmission units. Further, the first detection unit 618 is connected to the third force transmission unit 213 and the first electrode 615 of the first detection capacitor movable in the Y-axis direction, and the first detection fixed to the substrate 2 and connected to different potentials. A plurality of capacitance units 614 (first detection capacitance units) each including a second electrode 616 and a third electrode 617 are provided.
The amount of displacement corresponding to the force changes the capacitance between the first electrode 615 and the other two electrodes (the second electrode 616 and the third electrode 617). Can be detected. However, even if the third force transmission unit 213 and the first electrode 615 are displaced in the X-axis direction, the first detection unit 618 does not generate a difference in capacitance and therefore does not generate a detection signal. That is, the displacement amount only in the Y-axis direction can be detected.

  Since the detection unit 7 has such a configuration, the area of the capacitance necessary for signal detection can be increased. That is, the difference in capacitance change due to the Coriolis force can be increased, and the sensitivity of the physical quantity sensor 1 can be increased. In addition, although the modification of the detection part 7 of Embodiment 1 was demonstrated above, it can apply similarly in the detection part of Embodiment 2.

(Modification 2)
FIG. 7 is a schematic plan view illustrating a modification of the detection unit in the physical quantity sensor according to the first embodiment. In the physical quantity sensor 1, the force transmission unit 6 includes an integrated force transmission unit 611 having a “U” shape. A first detection unit 711 using a piezoelectric body is formed at a site where stress is concentrated when the force transmission unit 611 receives a force. In stress detection using a piezoelectric body, it is possible to detect by comparing the capacity change due to compressive stress and the capacity change due to tensile stress.
In this modification, the first piezoelectric body 712 and the second piezoelectric body 713 are provided, and the amount of force transmitted from the Coriolis force is detected by detecting the difference therebetween. Even in this case, even if the force transmission unit 611 is simply displaced in the X-axis direction, no difference is generated, so that no detection signal is generated. That is, the displacement amount only in the Y-axis direction can be detected.

  Since the detection unit 7 has such a configuration, an area necessary for signal detection can be reduced. That is, the physical quantity sensor 1 can be downsized. In addition, although the modification of the detection part 7 of Embodiment 1 was demonstrated above, it can apply similarly in the detection part of Embodiment 2.

(Modification 3)
FIG. 8 is a schematic plan view showing a modification of the present invention. The physical quantity sensor 14 has an X-axis physical quantity sensor 12 related to the X axis and a Y-axis physical quantity sensor 13 related to the Y axis in a sensor surface 3 parallel to the substrate 2. The X-axis physical quantity sensor 12 has the configuration of the physical quantity sensor 11 of the second embodiment, and is arranged in a form that requires a small area in the X-axis direction. The X-axis physical quantity sensor 12 can detect the angular velocity around the X axis with high sensitivity. On the other hand, the Y-axis physical quantity sensor 13 has the configuration of the physical quantity sensor 1 of the first embodiment and is arranged by being rotated by 90 degrees, so that it is arranged with a small required area in the X-axis direction. . The Y-axis physical quantity sensor 13 can detect the angular velocity around the Y axis with high sensitivity.

  As described above, the physical quantity sensor 14 is configured by combining the physical quantity sensor 1 of the first embodiment and the physical quantity sensor 11 of the second embodiment with a minimum area around the X axis and the Y axis. can do. Therefore, the physical quantity sensor 14 can provide a small and highly sensitive multi-axis physical quantity sensor.

FIG. 9 is a perspective view illustrating a configuration of a mobile (or notebook) personal computer to which an electronic device including the physical quantity sensor of the present invention is applied.
In FIG. 9, a personal computer 1100 includes a main body portion 1104 provided with a keyboard 1102 and a display unit 1106 provided with a display portion 100. The display unit 1106 is connected to the main body portion 1104 via a hinge structure portion. It is rotatably supported.
Such a personal computer 1100 incorporates the physical quantity sensor 1 of the present invention that functions as angular velocity detection means (gyro sensor).

FIG. 10 is a perspective view showing a configuration of a mobile phone (including PHS) to which an electronic device including the physical quantity sensor of the present invention is applied.
In FIG. 10, a mobile phone 1200 includes a plurality of operation buttons 1202, an earpiece 1204, and a mouthpiece 1206, and the display unit 100 is disposed between the operation buttons 1202 and the earpiece 1204.
Such a cellular phone 1200 incorporates the physical quantity sensor 1 of the present invention that functions as an angular velocity detection means (gyro sensor).

FIG. 11 is a perspective view illustrating a configuration of a digital still camera to which an electronic device including the physical quantity sensor of the present invention is applied. Note that FIG. 11 also shows a simple connection with an external device.
Here, a normal camera sensitizes a silver halide photographic film with a light image of a subject, whereas a digital still camera 1300 photoelectrically converts a light image of a subject with an image sensor such as a CCD (Charge Coupled Device). An imaging signal (image signal) is generated.
A display unit 100 is provided on the back of a case (body) 1302 in the digital still camera 1300, and is configured to display based on an imaging signal from the CCD. The display unit 100 displays a subject as an electronic image. Functions as a viewfinder.
A light receiving unit 1304 including an optical lens (imaging optical system), a CCD, and the like is provided on the front side (the back side in the drawing) of the case 1302.

When the photographer confirms the subject image displayed on the display unit 100 and presses the shutter button 1306, the CCD image pickup signal at that time is transferred and stored in the memory 1308.
In the digital still camera 1300, a video signal output terminal 1312 and an input / output terminal 1314 for data communication are provided on the side surface of the case 1302. As shown in the figure, a television monitor 1430 is connected to the video signal output terminal 1312 and a personal computer 1440 is connected to the input / output terminal 1314 for data communication as necessary. Further, the imaging signal stored in the memory 1308 is output to the television monitor 1430 or the personal computer 1440 by a predetermined operation.
Such a digital still camera 1300 incorporates the physical quantity sensor 1 of the present invention that functions as angular velocity detection means (gyro sensor).

  In addition to the personal computer of FIG. 9 (mobile personal computer), the mobile phone of FIG. 10, and the digital still camera of FIG. Inkjet printers), laptop personal computers, televisions, video cameras, video tape recorders, car navigation devices, pagers, electronic notebooks (including those with communication functions), electronic dictionaries, calculators, electronic game devices, word processors, workstations, televisions Telephone, crime prevention TV monitor, electronic binoculars, POS terminal, medical equipment (for example, electronic thermometer, blood pressure monitor, blood glucose meter, electrocardiogram measuring device, ultrasonic diagnostic device, electronic endoscope), fish detector, various measuring devices, instruments Type (e.g., vehicle, Sky machine, gauges of a ship), can be applied to a flight simulator or the like.

The physical quantity sensor of the present invention has been described based on the illustrated embodiment. However, the present invention is not limited to this, and the configuration of each part may be replaced with an arbitrary configuration having the same function. Can do.
In addition, any other component may be added to the present invention. Further, the present invention may be a combination of any two or more configurations (features) of the above embodiments.

DESCRIPTION OF SYMBOLS 1 ... Physical quantity sensor, 2 ... Board | substrate, 3 ... Sensor surface, 4 ... Mass part, 5 ... Drive part, 6 ... Force transmission part, 7 ... Detection part, 8, 9 ... Torsion spring, 10 ... Connection part, 11 ... Physical quantity Sensor (second embodiment), 12 ... X-axis physical quantity sensor, 13 ... Y-axis physical quantity sensor, 14 ... X-axis and Y-axis physical quantity sensor, 30, 31 ... Substrate fixing part (anchor), 40, 41 ... Torsion spring , 51... Drive unit, 210... First mass unit, 211... First force transmission unit, 212... Second force transmission unit, 213. First electrode of first detection comb teeth, 216... Second electrode of first detection comb teeth, 217... Third electrode of first detection comb teeth, 218... First detection portion, 219, 220. 1st connection part (connection part), 222,223 ... leaf spring, 241,242 ... board fixed Part (anchor), 251 to 254 ... leaf spring, 260 ... electrode, 310 ... second mass part, 311 ... fourth force transmission part, 312 ... fifth force transmission part, 313 ... sixth force transmission part, 314 ... first 2 detection comb teeth, 315... First electrode of second detection comb teeth, 316... Second electrode of second detection comb teeth, 317... Third electrode of second detection comb teeth, 318. 319, 320 ... torsion spring, 321 ... second connection part (connection part), 322, 323 ... leaf spring, 341, 342 ... substrate fixing part (anchor), 351-354 ... leaf spring, 360 ... electrode, 410 ... 1st mass part, 414 ... 1st detection comb tooth part, 415 ... 1st electrode of 1st detection comb tooth, 416 ... 2nd electrode of 1st detection comb tooth, 417 ... 1st detection comb tooth 1st 3 electrodes, 418 ... first detection section, 419, 420 ... torsion spring, 421 ... first connection section (connection section) 510 ... first mass part, 514 ... first detection comb tooth part, 515 ... first electrode of first detection comb tooth, 516 ... second electrode of first detection comb tooth, 517 ... first detection comb tooth ,..., First detecting section, 519, 420... Torsion spring, 521... First connecting section (connecting section), 614... First detecting capacitor section, 615. Electrodes, 616 ... second electrode of the first detection capacitor, 617 ... third electrode of the first detection capacitor, 618 ... first detection unit, 711 ... first detection unit, 712 ... first piezoelectric body, 713 ... Second piezoelectric body, 100 ... display unit, 1100 ... personal computer, 1102 ... keyboard, 1104 ... main body unit, 1106 ... display unit, 1200 ... mobile phone, 1202 ... operation button, 1204 ... earpiece, 1206 ... mouthpiece, 1300: Digital still camera, 1 302 ... Case, 1304 ... Light receiving unit, 1306 ... Shutter button, 1308 ... Memory, 1312 ... Video signal output terminal, 1314 ... Input / output terminal, 1430 ... TV monitor, 1440 ... Personal computer, J1 ... Rotating shaft in the first mass section , J2 ... rotation axis in the second mass part, J3 ... rotation axis of the drive part, V1 ... rotation direction of the first mass part, V2 ... rotation direction of the second mass part, F1, F2 ... Coriolis force.

Claims (10)

A substrate,
Two mass parts arranged above the substrate and aligned in the direction of the first axis;
A first torsion spring provided in each of the two mass parts and provided in the direction of a second axis perpendicular to the first axis in plan view;
A drive unit configured to rotate and vibrate the two mass units in opposite directions around the first torsion spring;
A force transmitting part connected to each of the two mass parts via the first torsion spring to transmit a force received from the mass part;
A physical quantity sensor, comprising: a detection unit provided in each of the force transmission units and detecting a displacement amount corresponding to the force as an electrical signal.   The said drive part is fixed to the said board | substrate via the 2nd torsion spring provided in the direction of the said 2nd axis | shaft, and rotates and vibrates on the said 2nd torsion spring as an axis | shaft. Physical quantity sensor.   3. The physical quantity sensor according to claim 1, wherein the driving unit is rotated and vibrated by an electrostatic force between an electrode provided on the driving unit and an electrode provided on the substrate.   4. The physical quantity sensor according to claim 1, wherein each of the two mass units is connected to the driving unit via a connection unit. 5.   5. The physical quantity sensor according to claim 1, wherein each of the force transmission units is provided at least at a part of the periphery of the mass unit.   6. The physical quantity sensor according to claim 1, wherein the first torsion spring is provided on each of the opposing side surfaces of the mass portion on the second axis.   The physical quantity sensor according to claim 2, wherein the first torsion spring is provided in parallel with the second torsion spring.   8. The physical quantity sensor according to claim 2, wherein the two mass parts are arranged at positions symmetrical to each other with respect to the second torsion spring.   The detection unit includes a movable electrode unit provided in the force transmission unit, and a fixed electrode unit provided on the substrate and at a position facing the movable electrode unit. The physical quantity sensor according to any one of claims 1 to 8.   An electronic apparatus comprising the physical quantity sensor according to any one of claims 1 to 9.

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