Physical quantity sensor with multiple masses and displacement conversion mechanism
09746489 · 2017-08-29
Assignee
Inventors
Cpc classification
International classification
Abstract
A functional element includes a driving portion, a first mass portion which is vibrated along the first direction, a first connection portion which is connected to the first mass portion and can perform a first movement in which the first connection portion contracts and extends along the first direction, a second connection portion which is connected to the first connection portion, extends in a second direction intersecting the first direction, and can perform a second movement in which the second connection portion rotates with the second direction as the axis, and a second mass portion which is connected to the second connection portion.
Claims
1. A functional element comprising: a driving portion; a first mass portion which is movable in a first direction and is driven by the driving portion; a first connection portion which is connected to the first mass portion at a first end and is extendable and contractible in the first direction along the length of the first connection portion; a second connection portion which is connected to a second end of the first connection portion and is formed in a second direction intersecting the first direction, the length of the second connection portion extending in the second direction; and a second mass portion which is connected to an end of the second connection portion, wherein the second mass portion can rotate with an axial center of the second connection portion as a rotational axis.
2. The functional element according to claim 1, wherein the first connection portion is asymmetrically connected to the second connection portion with respect to the axial center of the second connection portion.
3. The functional element according to claim 1, wherein the second mass portion includes a detection portion which detects a Coriolis force by at least one of a rotational movement having an axial center in the first direction and a rotational movement having an axial center in the second direction.
4. The functional element according to claim 1, wherein the first mass portion includes a detection portion which detects a Coriolis force by a rotational movement having an axial center in a direction orthogonal to the first direction.
5. The functional element according to claim 1, wherein the first connection portion is connected to a third mass portion opposite to the first mass portion.
6. The functional element according to claim 5, wherein the third mass portion includes a detection portion which detects a Coriolis force by a rotational movement having an axial center in a direction orthogonal to the first direction.
7. An electronic device on which the functional element according to claim 1 is mounted.
8. An electronic device on which the functional element according to claim 2 is mounted.
9. An electronic device on which the functional element according to claim 3 is mounted.
10. An electronic device on which the functional element according to claim 4 is mounted.
11. An electronic device on which the functional element according to claim 5 is mounted.
12. An electronic device on which the functional element according to claim 6 is mounted.
13. A moving object on which the functional element according to claim 1 is mounted.
14. A moving object on which the functional element according to claim 2 is mounted.
15. A moving object on which the functional element according to claim 3 is mounted.
16. A moving object on which the functional element according to claim 4 is mounted.
17. A moving object on which the functional element according to claim 5 is mounted.
18. A moving object on which the functional element according to claim 6 is mounted.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
(1) The invention will be described with reference to the accompanying drawings, wherein like numbers reference like elements.
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DESCRIPTION OF EXEMPLARY EMBODIMENTS
(19) Hereinafter, embodiments of the invention will be described with reference to the drawings. Moreover, in each drawing described below, in order to make a size of each component in the drawings be recognizable, the size and the ratio of each component may be described to be appropriately different from those of an actual component.
(20) First Embodiment
(21) A functional element 1 according to a first embodiment will be described with reference to
(22)
(23)
(24) Moreover, in
(25) Structure of Functional Element 1
(26) The functional element 1 of the embodiment includes a first mass portion 12, a second mass portion 14, a driving portion 22, a first connection portion 42, a second connection portion 44, a third connection portion 46, a first fixing portion 32, and a second fixing portion 36. In the functional element 1, the first mass portion 12 and the second mass portion 14 are connected to each other via the first connection portion 42 and the second connection portion 44. Moreover, according to vibration of the driving portion 22, a vibration speed component which is a movement along a first direction can be applied to the first mass portion 12, and a vibration speed component in a direction different from the first direction can be applied to the second mass portion 14 via the first connection portion 42 and the second connection portion 44.
(27) Hereinafter, the structure of the functional element 1 will be described in detail.
(28) First Mass Portion 12
(29) The first mass portion 12 is a weight which can be displaced by the vibration of the driving portion 22.
(30) A first detection portion 120 and a second detection portion 220 are provided on the first mass portion 12.
(31) Moreover, the first connection portion 42 and the third connection portion 46 are connected to the first mass portion 12.
(32) The first connection portion 42 is soft in the Y axis direction defined in
(33) The first detection portion 120 is provided as a sensor element which detects an angular velocity around the X axis which is defined in
(34) An example of the first detection portion 120 of the embodiment is shown in
(35) In the sensor element, the movable electrode 126 is displaced according to a rotational moment which is generated around the axis O-O′ according to the angular velocity, and thus, a gap between the movable electrode 126 and the fixed electrode 127 is changed. Accordingly, a gap between both electrodes is changed, and thus, capacitance generated between both electrodes is changed. The fixed electrode 127 is divided into two electrodes (fixed electrode 127 (+) and fixed electrode 127 (−)) having different potentials while interposing the axis O-O′, and a desired angular velocity can be effectively detected by differentially detecting the different potentials.
(36) The second detection portion 220 is provided as a sensor element which detects an angular velocity around the Z axis which is defined in
(37) An example of the second detection portion 220 of the embodiment is shown in
(38) In the sensor element, the movable mass portion 225 is displaced in the X axis direction according to the angular velocity, and thus, a gap between the movable electrode 226 and the fixed electrode 227 is changed. The fixed electrode 227 is divided into two electrodes (fixed electrode 227 (+) and fixed electrode 227 (−)) having different potentials, and a desired angular velocity can be effectively detected by differentially detecting the different potentials.
(39) Second Mass Portion 14
(40) Return to
(41) The second mass portion 14 is a mass (weight) which can be displaced according to the displacement of the first mass portion 12 by the vibration speed component. A third detection portion 320 is provided on the second mass portion 14. Moreover, the second connection portion 44 is connected to the second mass portion 14. The other end of the second connection portion 44 is fixed to the first fixing portion 32, and the second connection portion 44 acts as a torsion spring. That is, the second mass portion 14 can be rotated with the second connection portion 44 as the axis.
(42) In the third detection portion 320 provided on the second mass portion 14, a third detection portion 322 and a third detection portion 324 are provided in the Y axis direction (+Y axis direction and −Y axis direction) intersecting the X axis about the X axis along which the second connection portion 44 extends.
(43) The third detection portion 322 is disposed on the second mass portion 14 of the direction (+Y axis direction) side in which the first mass portion 12 is provided from the X axis along which the second connection portion 44 extends.
(44) The third detection portion 324 is disposed on the second mass portion 14 of a direction (−Y axis direction) side opposite to the direction in which the first mass portion 12 is provided from the X axis along which the second connection portion 44 extends.
(45) In addition, in descriptions below, when the third detection portions 322 and 324 are collectively referred to be included, it is referred to as the “third detection portion 320”.
(46) The third detection portion 320 is provided as a sensor element which detects an angular velocity around the Y axis which is defined in
(47) An example of the third detection portion 320 of the embodiment is shown in
(48) In the sensor element, the movable mass portion 325 is displaced in the X axis direction according to the angular velocity, and thus, a gap between the movable electrode 326 and the fixed electrode 327 is changed. Accordingly, capacitance generated between both electrodes is changed. The fixed electrode 327 is divided into two electrodes (fixed electrode 327 (+) and fixed electrode 327 (−)) having different potentials, and a desired angular velocity can be effectively detected by differentially detecting the different potentials.
(49) First Connection Portion 42
(50) Return to
(51) The first connection portion 42 extends toward the Y axis direction from the first mass portion 12.
(52) The bending portion 43 meandering in the X axis direction intersecting the Y axis direction in which the first connection portion 42 extends is provided on the first connection portion 42. The bending portion 43 is provided between the first mass portion 12 and the second connection portion 44. Since the first connection portion 42 includes the bending portion 43, the spring constant of the first connection portion in the Y axis direction can be decreased (the first connection portion can be soft).
(53) Moreover, the first connection portion 42 includes a connection region at the region in which the first connection portion 42 and the second connection portion 44 intersect each other. The connection region is provided at least between the second mass portion 14 and the first fixing portion 32. Moreover, a second connection portion 44L and a first connection portion 42L described below are connected to each other at the connection region, and thus, form a displacement conversion mechanism. In addition, a second connection portion 44R and a first connection portion 42R described below are connected to each other at the connection region, and thus, form a displacement conversion mechanism E. Moreover, in descriptions below, when the first connection portions 42L and 42R are collectively referred to be included, it is referred to as the “first connection portion 42”.
(54) Second Connection Portion 44 and First Fixing Portion 32
(55) The second connection portion 44 extends toward the X axis direction from the second mass portion 14. More specifically, the second connection portion 44 extends in both directions along the X axis about the second mass portion 14. The other end of the second connection portion 44, which is different from the one end connected to the second mass portion 14, is connected to the first fixing portion 32. The second connection portion 44 has a degree of freedom in a torsional direction, and can rotate the second mass portion 14. Accordingly, the rotational movement of the second mass portion 14 can be performed.
(56) The second connection portion 44 includes a second connection portion 44R which extends in the +X axis direction from the second mass portion 14, and a second connection portion 44L which extends in the −X axis direction, which is the direction opposite to the extension direction of the second connection portion 44R, from the second mass portion 14.
(57) The other end of the second connection portion 44R, which is different from the one end connected to the second mass portion 14, is connected to the first fixing portion 32R. The other end of the second connection portion 44L, which is different from the one end connected to the second mass portion 14, is connected to the first fixing portion 32L. Moreover, in descriptions below, when the second connection portions 44L and 44R are collectively referred to be included, it is referred to as the “second connection portion 44”.
(58) The above-described connection region will be described in detail.
(59) A relationship between the linear movement and the rotational movement described above is shown in
(60) Third Connection Portion 46 and Second Fixing Portion 36
(61) Return to
(62) The third connection portion 46 extends toward the +Y axis direction from the first mass portion 12.
(63) The other end of the third connection portion 46, which is different from the one end connected to the first mass portion 12, is connected to the second fixing portion 36. Similar to the first connection portion 42, the bending portion 43 meandering in the X axis direction intersecting the Y axis direction in which the third connection portion 46 extends is provided on the third connection portion 46. The bending portion 43 is provided between the first mass portion 12 and the second fixing portion 36. Since the third connection portion 46 includes the bending portion 43, the third connection portion 46 can be extended and contracted in the Y axis direction.
(64) Moreover, the third connection portion 46 includes a third connection portion 46L connected to the second fixing portion 36L and a third connection portion 46R connected to the second fixing portion 35R. Moreover, in descriptions below, when the third connection portions 46R and 46L are collectively referred to be included, it is referred to as the “third connection portion 46”. In addition, when the second fixing portions 36R and 36L are collectively referred to be included, it is referred to as the “second fixing portion 36”.
(65) Driving Portion 22
(66) The driving portion 22 vibrates the first mass portion 12, and is provided to apply a vibration speed component in the Y axis direction, which is a first direction, to the first mass portion 12.
(67) The method in which the driving portion 22 vibrates the first mass portion 12 is not particularly limited, and various piezoelectric drive elements or electrostatic drive elements can be used. As an example, the driving portion 22 of the embodiment uses the electrostatic drive element. Since the electrostatic drive element is used, by electrostatic induction generated between an electrode (not shown) provided on the driving portion 22 and an electrode (not shown) provided on the first mass portion 12, the first mass portion 12 is vibrated, and the vibration speed component in the Y axis direction can be applied to the first mass portion.
(68) Moreover, secondarily, the driving portion 22 may vibrate the second mass portion 14 in the direction of the rotational movement which is a second direction. The vibration method is not particularly limited, and various piezoelectric drive elements or various electrostatic drive elements may be used. Specifically, an electrode (not shown) for electrostatic driving is provided below the second mass portion 14, and thus, the second mass portion may be vibrated by the electrostatic induction.
(69) Operation of Functional Element 1
(70) An operation of the functional element 1 will be described with reference to
(71) The vibration speed component associated with the linear movement along the Y axis direction is applied to the first mass portion 12 by the vibration of the driving portion 22.
(72) When the first mass portion 12 is displaced in the +Y axis direction (a direction of an arrow Y1 in
(73) Moreover, in the following descriptions with respect to the operation of the functional element 1, this displacement is referred to as “first vibration speed displacement” by the vibration.
(74) When the first mass portion 12 is displaced in the −Y axis direction (a direction of an arrow Y2 in
(75) In addition, when the first vibration speed displacement and the second vibration speed displacement are collectively referred to be included, it is referred to as “vibration speed displacement”, and a direction in which the displacement is generated is referred to as a “vibration speed displacement direction”.
(76) In the functional element 1, as shown in
(77) Moreover, in the functional element 1, the vibration speed component in the direction different from the direction of the vibration speed component applied to the first mass portion 12 can be applied to the second mass portion 14.
(78) Operation When Rotation Movement with Z Axis as the Rotational Axis is Applied
(79) As shown in
(80) When the vibration speed displacement is generated in the first mass portion 12 as shown in
(81) According to the force by the Coriolis displacement, the movable electrode 226 (movable mass portion 225) included in the second detection portion 221 is displaced in the X axis direction. In the second detection portion 221, since the movable electrode 226 is displaced in the X axis direction, the gap between the fixed electrode 227 and the movable electrode 226 is changed, and thus, the rotational movement can be detected.
(82) As shown in
(83) As shown
(84) By this displacement, the counterclockwise rotational movement with the Z axis as the rotational axis can be detected.
(85) When the vibration speed displacement is generated in the first mass portion 12 as shown in
(86) As shown in
(87) As shown
(88) By this displacement, the clockwise rotational movement with the Z axis as the rotational axis can be detected.
(89) Operation When Rotation Movement with Y Axis as the Rotational Axis is Applied
(90) As shown in
(91) When the vibration speed displacement is generated in the second mass portion 14 as shown in
(92) According to the force by the Coriolis displacement, the movable electrode 326 (movable mass portion 325) included in the third detection portion 320 is displaced in the X axis direction. In the third detection portion 320, since the movable electrode 326 is displaced in the X axis direction, the gap between the fixed electrode 327 and the movable electrode 326 is changed, and thus, the rotational movement can be detected.
(93) As shown in
(94) As shown
(95) Here, the direction (Z axis direction) of the vibration speed displacement applied to the second mass portion 14, on which the third detection portion 322 and the third detection portion 324 are provided, is a reverse phase (reverse direction) to each other, and thus, the force by the Coriolis displacement is also generated in the reverse direction.
(96) By this displacement, the counterclockwise rotational movement with the Y axis as the rotational axis can be detected.
(97) When the vibration speed displacement is generated in the second mass portion 14 as shown in
(98) According to the force by the Coriolis displacement, the movable electrode 326 (movable mass portion 325) included in the third detection portion 320 is displaced in the X axis direction. In the third detection portion 320, since the movable electrode 326 is displaced in the X axis direction, the gap between the fixed electrode 327 and the movable electrode 326 is changed, and thus, the rotational movement can be detected.
(99) As shown in
(100) As shown
(101) Here, the direction (Z axis direction) of the vibration speed displacement applied to the second mass portion 14, on which the third detection portion 322 and the third detection portion 324 are provided, is a reverse direction to each other, and thus, the force by the Coriolis displacement is also generated in the reverse direction.
(102) By this displacement, the clockwise rotational movement with the Y axis as the rotational axis can be detected.
(103) Operation when Rotation Movement with X Axis as the Rotational Axis is Applied
(104) As shown in
(105) When the vibration speed displacement is generated in the first mass portion 12 as shown in
(106) According to the force by the Coriolis displacement, the movable electrode 126 included in the first detection portion 120 is displaced in the Z axis direction. In the first detection portion 120, since the movable electrode 126 is displaced in the Z axis direction, the gap between the fixed electrode 127 and the movable electrode 126 is changed, and thus, the rotational movement can be detected.
(107) As shown in
(108) As shown
(109) By this displacement, the counterclockwise rotational movement with the X axis as the rotational axis can be detected.
(110) When the vibration speed displacement is generated in the first mass portion 12 as shown in
(111) According to the force by the Coriolis displacement, the movable electrode 126 included in the first detection portion 120 is displaced in the Z axis direction. In the first detection portion 120, since the movable electrode 126 is displaced in the Z axis direction, the gap between the fixed electrode 127 and the movable electrode 126 is changed, and thus, the rotational movement can be detected.
(112) As shown in
(113) As shown
(114) By this displacement, the clockwise rotational movement with the X axis as the rotational axis can be detected.
(115) According to the above-described first embodiment, the following effects can be obtained.
(116) According to the functional element 1, the force associated with the vibration speed component which is obtained by the vibration of the first mass portion 12 is transmitted to the second connection portion 44 via the first connection portion 42, and thus, the vibration speed component in the direction different from the first mass portion 12 can be applied to the second mass portion 14 connected to the second connection portion 44. The Coriolis force orthogonal to the Y axis direction in which the vibration speed component applied to the first mass portion 12 is operated with respect to the rotational movement applied to the functional element 1 is generated in the first detection portion 120 and the second detection portion 220 provided in the first mass portion 12. The Coriolis force orthogonal to the Z axis direction in which the vibration speed component applied to the second mass portion 14 is operated with respect to the rotational movement applied to the functional element 1 is generated in the third detection portion 320 provided in the second mass portion 14.
(117) Accordingly, the first detection portion 120 can detect the rotational movement with the X axis as the axis, the second detection portion 220 can detect the rotational movement with the Z axis as the axis, and the third detection portion 320 can detect the rotational movement with the Y axis as the axis. Therefore, the functional element 1 can be realized, which can detect the rotational movements in the three axes in which the directions in the vibration speed components applied to the first mass portion 12 and the second mass portion 14 are different from one another while suppressing the disposition areas of the first mass portion 12 and the second mass portion 14. Moreover, since the disposition areas of the first mass portion 12 and the second mass portion 14 are suppressed, the functional element 1 capable of achieving a reduction in size and detecting the rotational movements of three axes can be realized.
(118) Second Embodiment
(119) A functional element 2 according to a second embodiment will be described with reference to
(120)
(121)
(122) Similar to the above-described functional element 1, the functional element 2 according to the second embodiment includes the first mass portion 12, the second mass portion 14, the driving portion 22, the first connection portion 42, the second connection portion 44, the third connection portion 46, the first fixing portion 32, and the second fixing portion 36. Moreover, a third mass portion 16 is provided on the functional element 2.
(123) In the functional element 2, the first mass portion 12 and the second mass portion 14 are connected to each other via the first connection portion 42 and the second connection portion 44. In addition, the first connection portion 42 is connected to the third mass portion 16.
(124) In the functional element 2, the first mass portion 12, the second mass portion 14, the third mass portion 16, and the driving portion 22 are disposed in point symmetry with the second connection portion 44 as the center.
(125) Moreover, according to vibration of the driving portion 22, vibration speed components having reverse phases can be applied to the first mass portion 12 and the third mass portion 16, and the vibration speed component can be applied to the second mass portion 14 via the first connection portion 42 and the second connection portion 44.
(126) Hereinafter, the structure of the functional element 2 will be described in detail. Moreover, the portions similar to the functional element 1 described in the first embodiment are partially omitted, and the structure of the functional element 2 will be described.
(127) First Mass Portion 12 and Third Mass Portion 16
(128) The first mass portion 12 and the third mass portion 16 are masses (weights) which can be displaced by the vibration of the driving portion 22.
(129) The first detection portion 120 and the second detection portion 220 are provided on each of the first mass portion 12 and the third mass portion 16.
(130) Moreover, the first connection portion 42 and the third connection portion 46 are connected to each of the first mass portion 12 and the third mass portion 16.
(131) The first connection portion 42 extended from the first mass portion 12 is extended from the first mass portion 12 toward the −Y axis direction in which the first mass portion 12 is vibrated by the vibration of the driving portion 22. Moreover, the third connection portion 46 extended from the first mass portion 12 is extended from the first mass portion 12 toward the +Y axis direction in which the first connection portion 42 is extended.
(132) The first connection portion 42 extended from the third mass portion 16 is extended in a first direction in which the third mass portion 16 is vibrated by the vibration of the driving portion 22 and is extended from the third mass portion 16 toward the direction (hereinafter, referred to as the “+Y axis direction”) in which the second mass portion 14 is provided. Moreover, the third connection portion 46 extended from the third mass portion 16 is extended from the first mass portion 12 toward the direction (hereinafter, referred to as the “−Y axis direction”) opposite to the +Y axis direction in which the first connection portion 42 is extended. In addition, in descriptions below, when the first direction is referred to include the +Y axis direction and the −Y axis direction, it is referred to as the “Y axis direction”.
(133) The first detection portion 120 is provided as a sensor element which detects the “Coriolis force” by the rotational movement with a second direction (hereinafter, referred to as the “X axis direction”) orthogonal to the Y axis direction as the axis. In the first detection portion 120, the detection method is not particularly limited, and various sensor elements can be used.
(134) Similar to the functional element 1 described in the first embodiment, the first detection portion 120 of the embodiment may use a so-called “flap type” sensor element, which includes the journaled movable electrode 126 and the fixed electrode 127 disposed to face the movable electrode 126 (refer to
(135) The second detection portion 220 is provided as a sensor element which detects the “Coriolis force” by the rotational movement with a third direction (hereinafter, referred to as the “Z axis direction”) orthogonal to the X axis direction and the Y axis direction as the axis. In the second detection portion 220, the detection method is not particularly limited, and various sensor elements can be used.
(136) Similar to the functional element 1 described in the first embodiment, as the second detection portion 220 of the embodiment, a so-called “interdigital” sensor element can be used, which includes a movable electrode 226 provided on the movable mass portion 225, and a fixed electrode 227 disposed to configure comb teeth (refer to
(137) Second Mass Portion 14
(138) The second mass portion 14 is a mass (weight) which can be displaced according to the displacement of the first mass portion 12 and the third mass portion 16 by the vibration speed component.
(139) The third detection portion 320 is provided on the second mass portion 14. Moreover, the second connection portion 44 is connected to the second mass portion 14.
(140) The second connection portion 44 extends from the second mass portion 14 toward the X axis direction (second direction) intersecting the Y axis direction (first direction) in which the first mass portion 12 and the third mass portion 16 are displaced by the vibration speed component.
(141) In the third detection portion 320 provided on the second mass portion 14, a third detection portion 322 and a third detection portion 324 are provided in the Y axis direction (+Y axis direction and −Y axis direction) intersecting the X axis about the X axis along which the second connection portion 44 extends.
(142) The third detection portion 322 is disposed on the second mass portion 14 of the direction (+Y axis direction) side in which the first mass portion 12 is provided from the X axis along which the second connection portion 44 extends.
(143) The third detection portion 324 is disposed on the second mass portion 14 of a direction (−Y axis direction) side opposite to the direction in which the first mass portion 12 is provided from the X axis along which the second connection portion 44 extends.
(144) The third detection portion 320 is provided as a sensor element which detects the “Coriolis force” by the rotational movement with the Y axis direction as the axis. In the third detection portion 320, the detection method is not particularly limited, and various sensor elements can be used.
(145) Similar to the above-described second detection portion 220, as the third detection portion 320 of the embodiment, a so-called “interdigital” sensor element can be used, which includes a movable electrode 326 provided on the movable mass portion 325, and a fixed electrode 327 disposed to configure comb teeth (refer to
(146) First Connection Portion 42
(147) The first connection portion 42 extends toward the third mass portion 16 which is provided in the −Y axis direction from the first mass portion 12.
(148) The other end of the first connection portion 42, which is different from the one end connected to the first mass portion 12, is connected to the second connection portion 44, and the first connection portion extends toward the third mass portion 16 and is connected to the third mass portion 16.
(149) The bending portion 43 meandering in the X axis direction intersecting the Y axis direction in which the first connection portion 42 extends is provided on the first connection portion 42. The bending portion 43 is provided between the first mass portion 12 and the second connection portion 44, and between the third mass portion 16 and the second connection portion 44.
(150) The first connection portion 42 includes the bending portion 43, and thus, can be extended and contracted in the Y axis direction.
(151) Moreover, the first connection portion 42 includes a first connection portion 42L which is connected to the second connection portion 44L described below. In addition, the first connection portion 42 includes a first connection portion 42R which is connected to the second connection portion 44R described below.
(152) Second Connection Portion 44 and First Fixing Portion 32
(153) The second connection portion 44 extends from the second mass portion 14 toward the X axis direction (second direction) intersecting the Y axis direction (first direction) in which the first mass portion 12 is displaced by the vibration speed component. More specifically, the second connection portion 44 extends in both directions along the X axis about the second mass portion 14. The other end of the second connection portion 44, which is different from the one end connected to the second mass portion 14, is connected to the first fixing portion 32.
(154) The second connection portion 44 includes the second connection portion 44R which extends in the +X axis direction from the second mass portion 14, and the second connection portion 44L which extends in the −X axis direction, which is the direction opposite to the extension direction of the second connection portion 44R, from the second mass portion 14.
(155) The other end of the second connection portion 44R, which is different from the one end connected to the second mass portion 14, is connected to the first fixing portion 32R. The other end of the second connection portion 44L, which is different from the one end connected to the second mass portion 14, is connected to the first fixing portion 32L.
(156) The displacement conversion mechanism E provided in the above-described connection region will be described in detail.
(157) Accordingly, when the first mass portion 12 and the third mass portion 16 linearly move, the force, which is applied to the first connection portion 42 according to the linear displacement, is transmitted to the second connection portion 44. At this time, since the point of application of the force is deviated from the axial center P, the linear movement of the first connection portion 42 is converted into the rotational moment of the second connection portion 44.
(158) Accordingly, the second connection portion 44 can rotate with the axial center P as the rotational axis. Moreover, the second mass portion 14 connected to the second connection portion 44 can rotate with the X axis along which the second connection portion 44 extends as the rotational axis. On the contrary, when the second mass portion 14 is rotated, a torsional force which is applied to the first connection portion 42 according to the displacement of the rotation is transmitted to the first connection portion 42. At this time, the rotational moment of the second connection portion 44 is converted into the linear movement of the first connection portion 42.
(159) The relationship between the linear movement and the rotational movement described above is shown in
(160) Moreover, the forces, which are applied to the first connection portion 42 extending from the first mass portion 12 and the first connection portion 42 extending from the third mass portion 16, and are displaced in the Y axis direction, are applied in the reverse phase.
(161) Third Connection Portion 46 and Second Fixing Portion 36
(162) Return to
(163) The third connection portion 46 extends from the first mass portion 12 and the third mass portion 16.
(164) The third connection portion 46 extending from the first mass portion 12 extends toward the +Y axis direction opposite to the direction in which the first connection portion 42 extends from the first mass portion 12, and the other end of the third connection portion different from the one end connected to the first mass portion 12 is connected to the second fixing portion 36. The third connection portion 46 extending from the third mass portion 16 extends toward the −Y axis direction opposite to the direction in which the first connection portion 42 extends from the third mass portion 16, and the other end of the third connection portion different from the one end connected to the first mass portion 12 is connected to the second fixing portion 36. Moreover, the third connection portion 46 includes a third connection portion 46L connected to the second fixing portion 36L and a third connection portion 46R connected to the second fixing portion 35R.
(165) Similar to the first connection portion 42, the bending portion 43 meandering in the X axis direction intersecting the Y axis direction in which the third connection portion 46 extends is provided on the third connection portion 46. The bending portion 43 is provided between the first mass portion 12 and the second fixing portion 36. Since the third connection portion 46 includes the bending portion 43, the third connection portion 46 can be extended and contracted in the Y axis direction.
(166) Driving Portion 22
(167) The driving portion 22 vibrates the first mass portion 12 and the third mass portion 16, and is provided to apply the vibration speed component in the Y axis direction, which is the first direction, to the first mass portion 12 and the third mass portion 16.
(168) The vibration of the driving portion 22 vibrates the first mass portion 12 and the third mass portion 16 in the reverse phase. Accordingly, the vibration speed displacement having the reverse phase can be applied to the first mass portion 12 and the third mass portion 16. The method in which the driving portion 22 vibrates the first mass portion 12 and the third mass portion 16 is not particularly limited, and various piezoelectric drive elements or electrostatic drive elements can be used. As an example, the driving portion 22 of the embodiment uses the electrostatic drive element. Since the electrostatic drive element is used, by electrostatic induction generated between an electrode (not shown) provided on the driving portion 22 and electrodes (not shown) provided on the first mass portion 12 and the third mass portion 16, the first mass portion 12 and the third mass portion 16 are vibrated, and the vibration speed components in the Y axis direction can be applied to the first mass portion and the third mass portion.
(169) Operation of Functional Element 2
(170) An operation of the functional element 2 will be described with reference to
(171) The vibration speed component associated with the linear movement having the reverse phase along the Y axis direction is applied to the first mass portion 12 and the third mass portion 16 by the vibration of the driving portion 22. That is, when the first mass portion 12 is displaced in the +Y axis direction, the third mass portion 16 is displaced in the −Y axis direction which is the reverse phase. Moreover, when the first mass portion 12 is displaced in the −Y axis direction, the third mass portion 16 is displaced in the +Y axis direction which is the reverse phase.
(172) When the first mass portion 12 is displaced in the +Y axis direction (the direction of the arrow Y1 in
(173) When the first mass portion 12 is displaced in the −Y axis direction (the direction of the arrow Y2 in
(174) In addition, when the first vibration speed displacement and the second vibration speed displacement are collectively referred to be included, it is referred to as “vibration speed displacement”, and the direction in which the displacement is generated is referred to as the “vibration speed displacement direction”.
(175) In the functional element 2, as shown in
(176) Moreover, in the functional element 2, the vibration speed component in the direction different from the direction of the vibration speed component applied to the first mass portion 12 and the third mass portion 16 can be applied to the second mass portion 14.
(177) Operation when Rotation Movement with Z Axis as the Rotational Axis is Applied
(178) As shown in
(179) When the vibration speed displacement is generated in the first mass portion 12 the third mass portion 16 as shown in
(180) According to the force by the Coriolis displacement, the movable electrode 226 (movable mass portion 225) included in the second detection portion 221 and the second detection portion 223 is displaced in the X axis direction. In the second detection portion 221 and the second detection portion 223, since the movable electrode 226 is displaced in the X axis direction, the gap between the fixed electrode 227 and the movable electrode 226 is changed, and thus, the rotational movement can be detected.
(181) As shown in
(182) As shown
(183) By this displacement, the counterclockwise rotational movement with the Z axis as the rotational axis can be detected.
(184) When the vibration speed displacement is generated in the first mass portion 12 and the third mass portion 16 as shown in
(185) As shown in
(186) As shown
(187) By this displacement, the clockwise rotational movement with the Z axis as the rotational axis can be detected.
(188) In addition, the rotational movement with the Z axis as the rotational axis is detected by differential motion which uses the second detection portion 221 provided on the first mass portion 12 and the second detection portion 223 provided on the third mass portion 16 being displaced in the reverse phase, and thus, the detection accuracy can be increased.
(189) Operation when Rotation Movement with Y Axis as the Rotational Axis is Applied
(190) As shown in
(191) When the vibration speed displacement is generated in the second mass portion 14 as shown in
(192) According to the force by the Coriolis displacement, the movable electrode 326 (movable mass portion 325) included in the third detection portion 320 is displaced in the X axis direction. In the third detection portion 320, since the movable electrode 326 is displaced in the X axis direction, the gap between the fixed electrode 327 and the movable electrode 326 is changed, and thus, the rotational movement can be detected.
(193) As shown in
(194) As shown in
(195) Here, the direction (Z axis direction) of the vibration speed displacement applied to the second mass portion 14, on which the third detection portion 322 and the third detection portion 324 are provided, is the reverse phase (reverse direction) to each other, and thus, the force by the Coriolis displacement is also generated in the reverse direction.
(196) By this displacement, the counterclockwise rotational movement with the Y axis as the rotational axis can be detected.
(197) When the vibration speed displacement is generated in the second mass portion 14 as shown in
(198) According to the force by the Coriolis displacement, the movable electrode 326 (movable mass portion 325) included in the third detection portion 320 is displaced in the X axis direction. In the third detection portion 320, since the movable electrode 326 is displaced in the X axis direction, the gap between the fixed electrode 327 and the movable electrode 326 is changed, and thus, the rotational movement can be detected.
(199) As shown in
(200) As shown
(201) Here, the direction (Z axis direction) of the vibration speed displacement applied to the second mass portion 14, on which the third detection portion 322 and the third detection portion 324 are provided, is a reverse direction, and thus, the force by the Coriolis displacement is also generated in the reverse direction.
(202) By this displacement, the clockwise rotational movement with the Y axis as the rotational axis can be detected.
(203) In addition, in the second mass portion 14, the third detection portion 322 and the third detection portion 324 are provided about the extension line of the second connection portion 44, the rotational movement with the Y axis as the rotational axis is detected by differential motion which uses the third detection portion 322 and the third detection portion 324 being displaced in the reverse phase, and thus, the detection accuracy can be increased.
(204) Operation when Rotation Movement with X Axis as the Rotational Axis is Applied
(205) As shown in
(206) When the vibration speed displacement is generated in the first mass portion 12 and the third mass portion 16 as shown in
(207) According to the force by the Coriolis displacement, the movable electrode 126 included in the first detection portion 121 and the first detection portion 123 is displaced in the Z axis direction. In the first detection portion 120, since the movable electrode 126 is displaced in the Z axis direction, the gap between the fixed electrode 127 and the movable electrode 126 is changed, and thus, the rotational movement can be detected.
(208) As shown in
(209) As shown
(210) By this displacement, the counterclockwise rotational movement with the X axis as the rotational axis can be detected.
(211) When the vibration speed displacement is generated in the first mass portion 12 and the third mass portion 16 as shown in
(212) According to the force by the Coriolis displacement, the movable electrode 126 included in the first detection portion 121 and the first detection portion 123 is displaced in the Z axis direction. In the first detection portion 121 and the first detection portion 123, since the movable electrode 126 is displaced in the Z axis direction, the gap between the fixed electrode 127 and the movable electrode 126 is changed, and thus, the rotational movement can be detected.
(213) As shown in
(214) As shown
(215) By this displacement, the clockwise rotational movement with the X axis as the rotational axis can be detected.
(216) In addition, the rotational movement with the X axis as the rotational axis is detected by differential motion which uses the first detection portion 121 provided on the first mass portion 12 and the first detection portion 123 provided on the third mass portion 16 being displaced in the reverse phase, and thus, the detection accuracy can be increased.
(217) According to the above-described second embodiment, the following effects can be obtained.
(218) According to the functional element 2, the first detection portion 120 can detect the rotational movement with the X axis as the axis by the differential motion, and the second detection portion 220 can detect the rotational movement with the Z axis as the axis by the differential motion. Moreover, the third detection portion 320 can detect the rotational movement with the Y axis as the axis. Therefore, the functional element 2 can be realized, which can detect the rotational movements in the three axes in which the directions in the vibration speed components applied to the first mass portion 12 and the second mass portion 14 are different from one another while suppressing the disposition areas of the first mass portion 12 and the second mass portion 14. Moreover, since the disposition areas of the first mass portion 12 and the second mass portion 14 are suppressed, the functional element 2 capable of achieving a reduction in size and detecting the rotational movements of three axes can be realized. Moreover, in the functional element 2, the rotational movements with the X axis and the Z axis as the axes are differentially detected by the first detection portion 120 and the third detection portion 320 provided on the first mass portion 12 and the third mass portion 16, and thus, the detection accuracy can be increased.
(219) Moreover, the functional element 1 and the functional element 2 are configured to include two or three mass portions in which the vibration speed displacement can be performed in the Y axis direction or the Z axis direction, and the number of the mass portions is smaller than that of the functional element of the related art. In addition, the degrees of freedom of the first connection portion 42 and the second connection portion 44 which are elastic connection mechanisms are limited to the Y axis and the X axis. Accordingly, in the functional element 1 and the functional element 2, unnecessary resonance frequency is suppressed. Therefore, the accuracy of the detection in the rotational movements with the X axis and the Z axis as the axes can be increased.
(220) Example
(221) Examples to which the functional element 1 and the functional element 2 according to the embodiments of the invention are applied will be described with reference to
(222) Electronic Device
(223) An electronic device to which the functional element 1 according to the embodiment of the invention is applied will be described with reference to
(224)
(225)
(226)
(227) A display portion 1308 is provided on the rear surface of a case (body) 1302 in a digital still camera 1300 and is configured to perform the display based on imaging signals of the CCD, and the display portion 1308 functions as a finder which displays the subject as an electronic image. Moreover, a light receiving unit 1304 including an optical lens (an imaging optical system), the CCD, or the like is provided on the front surface side (the rear surface side in the drawing) of the case 1302.
(228) If a photographer confirms a subject image displayed on the display portion 1308 and presses a shutter button 1306, the imaging signals of the CCD at the point in time are transmitted to and stored in a memory 1310. Moreover, in the digital still camera 1300, a video signal output terminal 1312, and an input and output terminal for data communication 1314 are provided on the side surface of the case 1302. In addition, as shown in
(229) In addition, for example, the functional element 1 according to the embodiments of the invention may be applied to an electronic device such as an ink jet type ejecting apparatus (for example, an ink jet printer), a television, a video camera, a video tape recorder, a car navigation apparatus, a pager, an electronic organizer (with a communication function), an electronic dictionary, an electronic calculator, electronic game equipment, a word processor, a work station, a video telephone, a television monitor for crime prevention, an electronic binocular, a POS terminal, medical equipment (for example, electronic thermometer, sphygmomanometer, blood sugar meter, electrocardiogram measurement device, ultrasonic diagnostic equipment, or electronic endoscope), a fish finder, various measurement devices, instruments (for example, instruments for vehicle, airplane, or ship), or a flight simulator, in addition to the laptop type personal computer (mobile type personal computer) shown in
(230) Moving Object
(231)
(232) In addition, the functional element 1 can be widely applied to a vehicle body posture control unit, an Antilock Brake System (ABS), an air bag, or a Tire Pressure Monitoring System (TPMS).