Patent ID: 12187598

DESCRIPTION OF EMBODIMENTS

An embodiment of the disclosure will be described in detail below with reference to the drawings. in the following description, the same or corresponding elements are denoted by the same reference numerals and the repeated description thereof will be omitted.

As illustrated inFIG.1, an actuator device1includes a support part2, a first movable part3, a second movable part4, a pair of first torsion bars (first connecting part)5and6, a pair of second torsion bars (second connecting part)7and8, and a magnetic field generator9. The support part2, the first movable part3, the second movable part4, the pair of first torsion bars5and6, and the pair of second torsion bars7and8are integrally formed by, for example, a Silicon on Insulator (SOI) substrate. That is, the actuator device1is formed of a MEMS device. In the actuator device1, the first movable part3provided with a mirror surface10is made to swing around each of an X axis (first axis) and a Y axis (second axis orthogonal to the first axis) orthogonal to each other. The actuator device1is used for, for example, an optical switch for optical communication, an optical scanner, and the like. The actuator device1is manufactured using a MEMS technology (patterning, etching, and the like).

The magnetic field generator9is formed of permanent magnets and the like arranged in a Halbach array. The magnetic field generator9generates, for example, a magnetic field in a direction D inclined with respect to each of the X axis and the Y axis by an angle of 45° in plan view (when viewed in a direction orthogonal to the X axis and the Y axis), and causes the magnetic field to act on a coil14to be described later. The direction D of the magnetic field generated by the magnetic field generator9may be inclined with respect to the X axis and the Y axis by an angle other than 45° in plan view.

The support part2has, for example, a rectangular outer shape in plan view and is formed in the shape of a frame. The support part2is arranged on one side of the magnetic field generator9in the direction orthogonal to the X axis and the Y axis. The first movable part3is arranged inside the support part2in a state where the first movable part3is spaced from the magnetic field generator9. The first movable part3includes a body portion3a, a ring shape portion3b, and a pair of connecting portions3c.

The body portion3ahas a circular shape in plan view, but may be formed in any shape, such as an elliptical shape, a rectangular shape, or a rhombic shape. The center P of the body portion3ain plan view coincides with the intersection of the X axis and the Y axis. The mirror surface10is provided on the surface of the body portion3aopposite to the magnetic field generator by a metal film made of, for example, aluminum. The mirror surface10is provided over the entire surface of the body portion, but may be provided on only a part of the surface of the body portion. The ring shape portion3bis formed in an ring shape shape so as to surround the body portion3ain plan view. The ring shape portion3bhas an octagonal outer shape in plan view, but may have an arbitrary outer shape, such as a circular shape, an elliptical shape, a rectangular shape, or a rhombic shape. The pair of connecting portions3cis arranged on both sides of the body portion3aon the Y axis, and connects the body portion3ato the ring shape portion3b.

The second movable part4is formed in the shape of a frame, and is arranged inside the support part2so as to surround the first movable part3in a state where the second movable part4is spaced from the magnetic field generator9. The detailed configuration of the second movable part4will be described later.

The first torsion bars5and6are arranged on both sides of the first movable part3on the X axis. The first torsion bars5and6connect the first movable part3(ring shape portion3b) to the second movable part4on the X axis so that the first movable part3can swing around the X axis (around the X axis as a center line). Each of the first torsion bars5and6extends linearly along the X axis. In this embodiment, for a reduction in stress acting on the first torsion bars5and6, the width of an end portion of each of the first torsion bars5and6close to the first movable part3increases as approaching the first movable part3, and the width of an end portion of each of the first torsion bars5and6close to the second movable part4increases as approaching the second movable part4.

The second torsion bars7and8are arranged on both sides of the second movable part4on the Y axis. The second torsion bars7and8connect the second movable part4to the support part2on the Y axis so that the second movable part4can swing around the Y axis (around the Y axis as a center line). Each of the second torsion bars7and8extends meanderingly in plan view. Each of the second torsion bars7and8includes a plurality of linear portions11and a plurality of folded portions12. The linear portions11extend in a Y-axis direction (second axis direction) parallel to the Y axis, and are arranged side by side in an X-axis direction (first axis direction) parallel to the X axis. The folded portions12alternately connect both ends of the adjacent linear portions11.

The actuator device1further includes a pair of coils14and15, a plurality of wirings21,22,23, and24, and a plurality of electrode pads25,26,27, and28. Each of the coils14and15is provided in the second movable part4so as to surround the first movable part3, and has a spiral shape in plan view. Each of the coils14and15is wound around the first movable part3a plurality of times. The pair of coils14and15is alternately arranged side by side in the width direction of the second movable part4in plan view. A region R where the coils14and15are arranged is illustrated inFIG.1by hatching. The detail shapes and arrangement of the coils14and15in plan view will be described later.

FIG.2is a cross-sectional view taken along line II-II illustrated inFIG.1. As illustrated inFIG.2, the second movable part4is provided with groove portions31having shapes corresponding to the respective coils14and15. An insulating layer32is provided on the inner surfaces of the groove portions31, and an insulating layer33is provided on the insulating layer32. Each of the coils14and15is arranged in the groove portion31via the insulating layers32and33. Each of the coils14and15is a damascene wiring embedded in the second movable part4. An insulating layer34is provided so as to cover the coils14and15and the insulating layer33. An insulating layer35is provided on the insulating layer34. Each of the insulating layers32to35is made of, for example, silicon oxide, silicon nitride, silicon oxynitride, or the like. Each of the insulating layers32to35is integrally formed so as to cover the surfaces (surfaces opposite to the magnetic field generator9) of the support part2, the first movable part3, the second movable part4, the first torsion bars5and6, and the second torsion bars7and8.

Each of the coils14and15is made of a metal material of which the density is higher than the density of the material of the second movable part4. In this embodiment, the second movable part4is made of silicon and each of the coils14and15is made of copper. Each of the coils14and15may be made of gold.

Each of the electrode pads25to28is provided on the support part2, and is exposed to the outside from the insulating layer35. The wiring21is electrically connected to one end of the coil14and the electrode pad25. The wiring21extends to the electrode pad25from one end of the coil14through the second torsion bar7. The wiring22is electrically connected to the other end of the coil14and the electrode pad26. The wiring22extends to the electrode pad26from the other end of the coil14through the second torsion bar8. Each of the wirings21and22may be a damascene wiring that is formed as with, for example, each of the coils14and15, and may be a wiring arranged on the surface of the support part2or the like.

The wiring23is electrically connected to one end of the coil15and the electrode pad27. The wiring23extends to the electrode pad27from one end of the coil15through the second torsion bar7. The wiring24is electrically connected to the other end of the coil15and the electrode pad28. The wiring24extends to the electrode pad28from the other end of the coil15through the second torsion bar8. Each of the wirings23and24may be a damascene wiring that is formed as with, for example, each of the coils14and15, and may be a wiring arranged on the surface of the support part2or the like.

In the actuator device1having the above-mentioned configuration, when a drive signal for a linear operation is input to the coil14through the electrode pads25and26and the wirings21and22, Lorentz force acts on the coil14due to an interaction between the drive signal and the magnetic field generated by the magnetic field generator9. The mirror surface10(first movable part3) can be linearly operated around the Y axis together with the second movable part4using a balance between the Lorentz force and the elastic forces of the second torsion bars7and8.

On the other hand, when a drive signal for a resonant operation is input to the coil15through the electrode pads27and28and the wirings23and24, Lorentz force acts on the coil15due to an interaction between the drive signal and the magnetic field generated by the magnetic field generator9. The mirror surface10(first movable part3) can be operated to resonate around the X axis using the resonance of the first movable part3at a resonant frequency in addition to the Lorentz force. Specifically, when a drive signal having a frequency equal to the resonant frequency of the first movable part3around the X axis is input to the coil15, the second movable part4slightly vibrates around the X axis at this frequency. This vibration is transmitted to the first movable part3through the first torsion bars5and6, so that the first movable part3can swing around the X axis at this frequency.

Subsequently, the detailed configuration of the second movable part4will be described. As illustrated inFIG.1, the second movable part4includes a pair of first connection portions41A and41B, a pair of second connection portions42A and42B, a pair of first linear portions43A and43B, a pair of second linear portions44A and44B, a pair of third linear portions45A and45B, and a pair of fourth linear portions46A and46B. The second movable part4has a shape symmetrical with respect to each of the X axis and the Y axis in plan view. In the following description, symmetry with respect to the X axis or the Y axis means symmetry in plan view.

The first connection portions41A and41B are positioned on both sides of the first movable part3on the X axis. Each of the first connection portions41A and41B includes a portion facing the first movable part3in the X-axis direction in plan view. Each of the first connection portions41A and41B extends in the Y-axis direction. The first connection portions41A and41B are connected to the first torsion bars5and6. That is, the first torsion bars5and6are connected to the second movable part4at the first connection portions41A and41B.

The second connection portions42A and42B are positioned on both sides of the first movable part3on the Y axis. Each of the second connection portions42A and42B includes a portion facing the first movable part3in the Y-axis direction in plan view. Each of the second connection portions42A and42B extends in the X-axis direction. The second connection portions42A and42B are connected to the second torsion bars7and8. That is, the second torsion bars7and8are connected to the second movable part4at the second connection portions42A and42B.

The first linear portions43A and43B are positioned on both sides of the second connection portion42A in the X-axis direction, and are connected to the second connection portion42A. Each of the first linear portions43A and43B extends in the X-axis direction. The first linear portions43A and43B are arranged symmetrically to each other with respect to the Y axis. The second linear portions44A and44B are positioned on both sides of the second connection portion42B in the X-axis direction, and are connected to the second connection portion42B. Each of the second linear portions44A and44B extends in the X-axis direction. The second linear portions44A and44B are arranged symmetrically to each other with respect to the Y axis.

The third linear portions45A and45B are positioned on the sides opposite to the second connection portion42A with respect to the first linear portions43A and43B, and are connected to the first linear portions43A and43B and the first connection portions41A and41B. The third linear portion45A extends in a direction inclined with respect to each of the X axis and the Y axis by an angle of 45° in plan view. The third linear portion45B extends symmetrically to the third linear portion45A with respect to the Y axis. A direction in which the third linear portion45A extends may be inclined with respect to the X axis and the Y axis by an angle other than 45°.

The fourth linear portions46A and46B are positioned on the sides opposite to the second connection portion42B with respect to second linear portions44A and44B, and are connected to the second linear portions44A and44B and the first connection portions41A and41B. The fourth linear portion46A extends symmetrically to the third linear portion45A with respect to the X axis. The fourth linear portion46B extends symmetrically to the fourth linear portion46A with respect to the Y axis, and extends symmetrically to the third linear portion45B with respect to the X axis.

The configuration of the second connection portion42A will be described in more detail with reference toFIG.3. The second connection portion42A will be described below. However, the second connection portion42B is configured symmetrically to the second connection portion42A with respect to the X axis, and has the same configuration as the second connection portion42A. An inner edge51of the second connection portion42A in plan view includes one depression portion52recessed in the Y-axis direction. The depression portion52is recessed from the inner edge of each of the first linear portions43A and43B toward the side opposite to the first movable part3. The depression portion52is positioned on the Y axis in plan view. The depression portion52is provided over a region of the second connection portion42A facing the first movable part3in plan view. The inner edge51of the region where the depression portion52is formed is curved so as to go away from the first movable part3as approaching the Y axis. The inner edge51of a region where the depression portion52is not formed extends in the X-axis direction. The curvature of the inner edge51is continuous at a boundary between the region where the depression portion52is formed and the region where the depression portion52is not formed.

An outer edge53of the second connection portion42A in plan view includes one protrusion portion54protruding in the Y-axis direction. The protrusion portion54protrudes from the outer edge of each of the first linear portions43A and43B toward the side opposite to the first movable part3. The protrusion portion54is positioned on the Y axis in plan view. The protrusion portion54is provided over a region of the second connection portion42A facing the first movable part3in plan view. The protrusion portion54does not have a shape corresponding to the depression portion52. That is, the outer edge53includes a portion formed not along the inner edge51. The outer edge53of a region where the protrusion portion54is formed includes a linear portion53aand a pair of curved portions53b. The linear portion53aextends in the X-axis direction, and crosses the Y axis in plan view. Each curved portion53bhas a curved shape so as to be recessed inward, and is connected to the linear portion53a. The curvature of the outer edge53is continuous at a boundary between the linear portion53aand each curved portion53b. The pair of curved portions53bis connected to the outer edges of the first linear portions43A and43B so that the curvature is continuous at the boundary.

The second connection portion42A includes a portion (widened portion) having a width larger than the width of a portion of the second movable part4other than the first connection portions41A and41B and the second connection portions42A and42B in plan view. In this embodiment, the widths of the respective linear portions43A to46B are equal to each other. Accordingly, the width (maximum width) W1of the portion of the second movable part4other than the first connection portions41A and41B and the second connection portions42A and42B is the width of each of the linear portions43A to46B. The width of the second connection portion42A is the minimum width W2on the Y axis. The minimum width W2is larger than the width W1. Accordingly, the entire second connection portion42A has a width larger than the width W1in this embodiment.

Further, the minimum width W2of the second connection portion42A is larger than the width (maximum width) W3of each of the first connection portions41A and41B. The width W3of each of the first connection portions41A and41B is larger than the above-mentioned width W1, but may be equal to the width W1or may be smaller than the width W1. A boundary between the first connection portion41A and the first torsion bar5is illustrated inFIG.3by a one-dot chain line B. The width of a certain portion of the second movable part4is a distance between the inner edge and the outer edge of this portion in plan view, that is, is the width of this portion in a direction (width direction) orthogonal to a direction orthogonal to the X axis and the Y axis and a direction orthogonal to the extending direction of this portion. For example, the width of the first connection portion41A is the width of the first connection portion41A in the X-axis direction, and the width of the second connection portion42A is the width of the second connection portion42A in the Y-axis direction.

Subsequently, the detail shapes and arrangement of the coils14and15in plan view will be described. As illustrated inFIGS.1and3, each of the coils14and15extends in the extending directions of the first connection portions41A and41B and the respective linear portions43A to46B at the first connection portions41A and41B and the respective linear portions43A to46B. Each of the coils14and15provided at the third and fourth linear portions45B and46A extends in a direction orthogonal to the magnetic field generated by the magnetic field generator9. At the first connection portions41A and41B and the respective linear portions43A to46B, the outer edge of the region R where the coils14and15are arranged extends along the outer edges of the first connection portions41A and41B and the respective linear portions43A to46B and the inner edge of the region R extends along the inner edges of the first connection portions41A and41B and the respective linear portions43A to46B.

As illustrated inFIG.3, the region R in the second connection portion42A includes a first portion55, a pair of second portions56, and a pair of third portions57. The first portion55extends in the X-axis direction, and crosses the Y axis in plan view. The pair of second portions56is positioned on both sides of the first portion55in the X-axis direction, and is connected to the first portion55. One second portion56extends in the direction inclined with respect to each of the X axis and the Y axis by an angle of 45°. The other second portion56extends symmetrically to one second portion56with respect to the Y axis. Each of the coils14and15provided in the other second portion56extends in the direction orthogonal to the magnetic field generated by the magnetic field generator9. The first portion55is arranged at a position closer to the outer edge53than the inner edge51of the second connection portion42A. That is, a distance between the first portion55and the inner edge51is longer than a distance between the first portion55and the outer edge53. The pair of third portions57is positioned on the sides opposite to the first portion55with respect to the second portions56, and is connected to the pair of second portions56and the region R of the first linear portions43A and43B. Each third portion57extends in the X-axis direction. A direction where one second portion56extends may be inclined with respect to the X axis and the Y axis by an angle other than 45°.

As described above, in the actuator device1, each of the pair of second connection portions42A and42B positioned on both sides of the first movable part3on the Y axis includes a portion having a width larger than the width of a portion of the second movable part4other than the first connection portions41A and41B and the second connection portions42A and42B. Accordingly, while an increase in the moment of inertia of the second movable part4about the Y axis is suppressed, the moment of inertia of the second movable part4about the X axis can be increased. That is, the resonant frequency of the second movable part4around the Y axis is larger as the moment of inertia of the second movable part4about the Y axis is smaller. It is more difficult for the second movable part4to be deformed around the X axis as the moment of inertia of the second movable part4about the X axis is larger. Accordingly, both the ensuring of the resonant frequency of the second movable part4around the Y axis and the suppression of the deformation of the second movable part4around the X axis can be achieved in the actuator device1.

Further, in the actuator device1, the inner edge51of each of the second connection portions42A and42B in plan view includes the depression portion52recessed in the Y-axis direction. Accordingly, the size of the second movable part4can be reduced in the Y-axis direction, so that an increase in the moment of inertia of the second movable part4about the Y axis can be further suppressed. Furthermore, the outer edge53of each of the second connection portions42A and42B in plan view includes the protrusion portion54protruding in the Y-axis direction. Accordingly, the moment of inertia of the second movable part4about the X axis can be further increased. Moreover, since each of the second connection portions42A and42B is positioned on the Y axis, an increase in the moment of inertia of the second movable part4about the Y axis can be still further suppressed. Therefore, according to the actuator device1, both the ensuring of the resonant frequency of the second movable part4around the Y axis and the suppression of the deformation of the second movable part4around the X axis can be achieved in the actuator device1in which the first movable part3swings around the X axis and the second movable part4surrounding the first movable part3swings around the Y axis. For example, according to the actuator device1, the moment of inertia of the second movable part4about the X axis can be effectively increased in comparison with a case where the outer shape of the second movable part4in plan view is a substantially rhombic shape.

In the actuator device1, the second movable part4further includes the first linear portions43A and43B and the second linear portions44A and44B. Accordingly, while an increase in the moment of inertia of the second movable part4about the Y axis is effectively suppressed, the moment of inertia of the second movable part4about the X axis can be effectively increased.

In the actuator device1, the second movable part4further includes the third linear portions45A and45B and the fourth linear portions46A and46B. Accordingly, the length of a portion of the second movable part4extending in the Y-axis direction can be shortened. As a result, while an increase in the moment of inertia of the second movable part4about the Y axis is more effectively suppressed, the moment of inertia of the second movable part4about the X axis can be more effectively increased.

In the actuator device1, the depression portions52and the protrusion portions54are positioned on the Y axis in plan view. Accordingly, while an increase in the moment of inertia of the second movable part4about the Y axis is still more effectively suppressed, the moment of inertia of the second movable part4about the X axis can be still more effectively increased.

The actuator device1includes the coils14and15and the magnetic field generator9. Accordingly, both the ensuring of the resonant frequency of the second movable part4around the Y axis and the suppression of the deformation of the second movable part4around the X axis can be achieved while an arrangement space of the coils14and15is ensured in the second movable part4.

In the actuator device1, each of the coils14and15is arranged at a position that is closer to the outer edge53than the inner edge51of each of the second connection portions42A and42B. Accordingly, the moment of inertia of the second movable part4about the X axis can be still more effectively increased.

In the actuator device1, each of the coils14and15includes a portion extending in the direction orthogonal to the magnetic field. Accordingly, Lorentz force, which is generated by an interaction between current flowing through the coils14and15and a magnetic field, can be increased.

In the actuator device1, each of the coils14and15is made of a metal material of which the density is higher than the density of the material of the second movable part4and is embedded in the second movable part4. Accordingly, the moment of inertia of the second movable part4about the X axis can be still more effectively increased.

In the actuator device1, each of the second connection portions42A and42B includes a portion having a width larger than the width of each of the first connection portions41A and41B. Accordingly, while an increase in the moment of inertia of the second movable part4about the Y axis is still more effectively suppressed, the moment of inertia of the second movable part4about the X axis can be still more effectively increased.

In the actuator device1, the depression portion52is provided over a region of each of the second connection portions42A and42B facing the first movable part3in plan view. Accordingly, the moment of inertia of the second movable part4about the X axis can be still more effectively increased. Further, a space where the first movable part3swings can be suitably ensured.

In the actuator device1, each of the second torsion bars7and8extends meanderingly in plan view. Accordingly, the strength of each of the second torsion bars7and8can be improved, and the adjustment of the spring constants of the second torsion bars7and8can be facilitated. Further, even though the length of the second movable part4in the Y-axis direction is increased due to the protrusion portions54, an increase in the size of the device in the Y-axis direction can be suppressed.

One embodiment of the disclosure has been described above, but the disclosure is not limited to the embodiment. The second movable part4may be adapted as in a modification illustrated in, for example,FIG.4. In this modification, the second movable part4includes a fifth linear portion61, a sixth linear portion62, a seventh linear portion63, and an eighth linear portion64. The fifth linear portion61is connected to the first connection portion41A and the second connection portion42A. The sixth linear portion62is connected to the first connection portion41A and the second connection portion42B. The seventh linear portion63is connected to the first connection portion41B and the second connection portion42A. The eighth linear portion64is connected to the first connection portion41B and the second connection portion42B. The fifth linear portion61extends in a direction inclined with respect to the X axis and the Y axis in plan view. The sixth linear portion62extends symmetrically to the fifth linear portion61with respect to the X axis. The seventh linear portion63extends symmetrically to the fifth linear portion61with respect to the Y axis. The eighth linear portion64extends symmetrically to the sixth linear portion62with respect to the Y axis. The eighth linear portion64extends symmetrically to the seventh linear portion63with respect to the X axis. Even in this modification, as in the embodiment, both the ensuring of the resonant frequency of the second movable part4around the Y axis and the suppression of the deformation of the second movable part4around the X axis can be achieved. Further, since the second movable part4includes the linear portions61to64, the moment of inertia of the second movable part4about the X axis can be effectively increased while an increase in the moment of inertia of the second movable part4about the Y axis is effectively suppressed.

The first movable part3is driven by an electromagnetic force in the embodiment, but the first movable part3may be driven by a piezoelectric element. In this case, for example, the second movable part4is provided with a first piezoelectric film that causes the first movable part3to swing around the X axis, instead of the coils14and15. The first piezoelectric film is arranged on, for example, the second connection portions42A and42B, the first linear portions43A and43B, and the second linear portions44A and44B. Further, each of the second torsion bars7and8is provided with a second piezoelectric film that causes the second movable part4to swing around the Y axis. The magnetic field generator9will be omitted.

The first and second movable parts3and4are linearly operated around the Y axis in the embodiment, but the first and second movable parts3and4may be operated to resonate around the Y axis. The second movable part4is provided with the pair of coils14and15in the embodiment, but the second movable part4may be provided with only one coil. Even in this case, the first movable part can swing around the X axis and the second movable part4can swing around the Y axis by the input of a drive signal to the coil. Alternatively, the first movable part3may be provided with one coil that causes the first movable part3to swing around the X axis, and the second movable part4may be provided with one coil that causes the second movable part4to swing around the Y axis. In the embodiment, the second movable part4may be provided with an electromotive force-monitoring coil for measuring an electromotive force and the support part2may be provided with a temperature sensor coil for measuring a temperature. The respective coils14and15may be arranged on the second movable part4without being embedded in the second movable part4.

The material and shape of each component are not limited to the above-mentioned material and shape, and various materials and shapes can be employed. The outer edge53of each of the second connection portions42A and42B may include a plurality of protrusion portions protruding in the Y-axis direction. For example, the outer edge53may include a pair of protrusion portions arranged symmetrically to each other with respect to the Y axis. In this case, the outer edge53between the two protrusion portions extends linearly in the X-axis direction, and the second torsion bars7and8may be connected to this linear portion. In this case, the protrusion portions are not positioned on the Y axis in plan view. Likewise, the inner edge51of each of the second connection portions42A and42B may include a plurality of depression portions recessed in the Y-axis direction, and the depression portions may not be positioned on the Y axis in plan view. The shape of each of the depression portion52and the protrusion portion54in plan view may be an arbitrary shape, such as a rectangular shape, a semicircular shape, or a semi-elliptical shape. The protrusion portion54may be provided with a slit or a depression portion.

Each of the second connection portions42A and42B has only to include a portion having a width larger than the width W1of a portion of the second movable part4other than the first connection portions41A and41B and the second connection portions42A and42B, and may include a portion having a width equal to the width W1or a width smaller than the width W1. Each of the second connection portions42A and42B may not include a portion having a width larger than the width W3of each of the first connection portions41A and41B.

The shape of the second movable part4is not limited to the above-mentioned example. For example, the third linear portions45A and45B and the fourth linear portions46A and46B may not be provided, and the first linear portions43A and43B and the second linear portions44A and44B may be directly connected to the first connection portions41A and41B. Alternatively, the first linear portions43A and43B and the second linear portions44A and44B may not be provided, and third linear portions45A and45B and the fourth linear portions46A and46B may be directly connected to the second connection portions42A and42B. The second movable part4may have a substantially circular shape, a substantially elliptical shape, a substantially rectangular shape, or the like in plan view. The ring shape portion3bmay not be provided, and the first torsion bars5and6may be directly connected to the body portion3a. The first torsion bars5and6have only to be arranged on both sides of the first movable part3in the X-axis direction, and may connect the first movable part3to the second movable part4at positions other than the positions on the X axis. The second torsion bars7and8have only to be arranged on both sides of the second movable part4in the Y-axis direction, and may connect the second movable part4to the support part2at positions other than the positions on the Y axis. The second torsion bars7and8may extend linearly in plan view. The actuator device1may be a device to drive a portion other than the mirror surface10. Each of the linear portions43A to46B has only to extend in a certain direction, the inner edge of at least one of the linear portions43A to46B in plan view may include a depression portion or a protrusion portion, and the outer edge of at least one of the linear portions43A to46B in plan view may include a depression portion or a protrusion portion.

REFERENCE SIGNS LIST

1: actuator device,2: support part,3: first movable part,4: second movable part,5,6: first torsion bar (first connecting part),7,8: second torsion bar (second connecting part),9: magnetic field generator,14,15: coil,41A,41B: first connection portion,42A,42B: second connection portion,43A,43B: first linear portion,44A,44B: second linear portion,45A,45B: third linear portion,46A,46B: fourth linear portion,51: inner edge,52: depression portion,53: outer edge,54: protrusion portion.