JP6633734B2 - Actuator - Google Patents

Description

  The present invention relates to a technical field of an actuator such as a MEMS scanner that drives a movable unit provided with a mirror and the like.

  For example, in various technical fields such as a display, a printing apparatus, precision measurement, precision processing, and information recording / reproduction, research on a MEMS (Micro Electro Mechanical System) device manufactured by a semiconductor process technology is actively advanced. As such a MEMS device, a MEMS scanner used for laser beam scanning is known. Such a MEMS scanner includes a movable plate, a frame-shaped support frame surrounding the movable plate, and a torsion bar for pivotally supporting the movable plate with respect to the support frame.

  As prior arts that disclose such a MEMS scanner, Patent Documents 1 to 3 are given as examples.

JP 2001-525972 A JP-T-2002-524271 JP-A-2004-177543

  As a method of utilizing such a MEMS scanner, for example, it is assumed that the MEMS scanner is used for an image display device such as a head-up display for projecting an image. Here, when the MEMS scanner is used for an image display device such as a head-up display, the frequency of the oscillating motion of the movable plate (for example, the mass of the movable plate and the It is preferable to increase the resonance frequency determined by the spring constant of the torsion bar to be supported.

  As one measure for increasing the frequency of the swinging motion of the movable plate, a measure for increasing the thickness of the torsion bar or shortening the torsion bar to make the torsion bar harder (in other words, increasing the spring constant of the torsion bar) can be considered. However, simply increasing the thickness of the torsion bar causes a technical problem that the stress applied to the torsion bar increases as the movable plate swings as much as the thickness of the torsion bar increases. Similarly, if the torsion bar is simply shortened, there is a technical problem that the stress applied to the torsion bar increases as the movable plate swings as much as the torsion bar is shortened. As a result, there arises a technical problem that such an increase in stress may cause breakage of the torsion bar.

  The present invention has been made in consideration of, for example, the above-described conventional problems, and provides an actuator capable of increasing the frequency at which a movable portion moves while preventing or suppressing breakage of a torsion bar, for example. As an issue.

  In order to solve the above-described problem, the actuator has a movable portion, a support portion that supports the movable portion, and (i) each such that the movable portion can swing around a rotation axis along a longitudinal direction. And connecting the movable portion and the support portion along the longitudinal direction, and (ii) a plurality of torsion bars arranged along the lateral direction, each of the plurality of torsion bars. Becomes smaller as the respective torsion bars are farther from the rotation axis.

  The operation and other advantages of the present invention will become more apparent from the embodiments explained below.

FIG. 3 is a plan view illustrating an example of a configuration of the actuator according to the first embodiment. FIG. 3 is an enlarged plan view illustrating an example of details of the shape of a pair of torsion bars provided in the actuator of the first embodiment. FIG. 11 is an enlarged plan view illustrating an example of a configuration of an actuator of a comparative example in which a movable portion is rotated using only one torsion bar located on a rotation axis. It is an enlarged plan view showing an example of the shape of a plurality of pairs of torsion bars provided in the actuator of the second embodiment. FIG. 13 is an enlarged plan view illustrating an example of details of the shape of a pair of torsion bars provided in the actuator of the third embodiment. FIG. 14 is an enlarged plan view illustrating an example of details of the shape of a pair of torsion bars provided in the actuator of the fourth embodiment. It is an enlarged plan view showing an example of the shape in detail of a plurality of pairs of torsion bars provided in the actuator of the fifth embodiment. It is an enlarged plan view showing an example of the shape of a plurality of pairs of torsion bars provided in the actuator of the sixth example in detail. It is an enlarged plan view showing an example of the details of the shape of a plurality of pairs of torsion bars provided in the actuator of the seventh embodiment. It is an enlarged plan view showing an example of the shape in detail of a plurality of pairs of torsion bars provided in the actuator of the eighth embodiment. It is a top view showing an example of the composition of the actuator of a 9th example. It is a top view showing an example of the composition of the actuator of a 10th example.

  Hereinafter, embodiments of the actuator will be sequentially described.

  The actuator according to the present embodiment includes a movable portion, a support portion that supports the movable portion, and (i) each of the longitudinal portions such that the movable portion can swing about a rotation axis along a longitudinal direction. Along with connecting the movable portion and the support portion along a direction, (ii) a plurality of torsion bars arranged along the lateral direction, each spring constant of the plurality of torsion bars is The smaller the distance between the respective torsion bars and the axis of rotation, the smaller.

  According to the actuator of the present embodiment, the movable portion suspended by the plurality of torsion bars moves. For example, the movable portion may move so as to rotate about an axis along a direction in which each of the plurality of torsion bars extends (that is, a longitudinal direction of each of the plurality of torsion bars) as a rotation axis.

  In order to realize such rotation of the movable part, each of the plurality of torsion bars connects the movable part and the support part along the longitudinal direction of the respective torsion bar. At this time, each of the plurality of torsion bars may directly connect the movable part and the support part. Alternatively, each of the plurality of torsion bars may indirectly connect the movable portion and the support portion (in other words, with an arbitrary member interposed therebetween). In addition, the plurality of torsion bars are arranged along the short direction of the plurality of torsion bars (in other words, they are arranged in parallel). In other words, the plurality of torsion bars are arranged along a direction orthogonal to the rotation axis of the movable part.

  In the present embodiment, the spring constants of the plurality of torsion bars are adjusted according to the distance between the rotation axis of the movable part and each of the plurality of torsion bars. More specifically, the spring constant of each of the plurality of torsion bars becomes smaller as the respective torsion bar becomes farther from the rotation axis (that is, as the distance from the rotation axis becomes larger). Has been adjusted. In other words, the spring constant of each of the plurality of torsion bars is adjusted so that the spring constant of the torsion bar farther from the rotation axis becomes smaller. In other words, the spring constant of each of the plurality of torsion bars is adjusted such that the spring constant of the torsion bar relatively far from the rotation axis is smaller than the spring constant of the torsion bar relatively close to the rotation axis. I have. In the case where the middle torsion bar of the plurality of torsion bars is located on the rotation axis, the spring constant of each of the plurality of torsion bars is located relatively outside of the array along the short direction. It can also be said that the torsion bar is adjusted so that the spring constant of the torsion bar is smaller than the spring constant of the torsion bar located relatively at the center side of the array along the short direction.

  Here, the stress applied to the torsion bar when the movable portion supported by only one torsion bar located on the rotation axis moves far will be described. When such a movable part swings, the stress applied to the edges on both sides of the single torsion bar (more specifically, the edges on both sides along the short direction of the torsion bar) is The stress is larger than the stress applied to the central portion (more specifically, the central portion along the short direction of the torsion bar). That is, the stress applied to the edge portion of the single torsion bar relatively far from the rotation axis is larger than the stress applied to the central portion of the single torsion bar relatively close to the rotation axis. That is, the stress applied to the single torsion bar as the movable portion moves farther is more easily applied farther from the rotation axis.

  Considering how such stress is applied, according to the actuator including a plurality of torsion bars in which the spring constant decreases as the distance from the rotation axis increases, the distance from the rotation axis increases. Stress is likely to be applied to a torsion bar (that is, a torsion bar having a relatively small spring constant). However, due to the relatively small spring constant, the stress applied to the torsion bar relatively far from the rotation axis is reduced. For this reason, destruction of the torsion bar relatively far from the rotation axis is preferably prevented or suppressed. On the other hand, a torsion bar relatively close to the rotation axis (that is, a torsion bar having a relatively large spring constant) does not receive a large stress. For this reason, destruction of the torsion bar relatively close to the rotation axis is also suitably prevented or suppressed. Therefore, according to the actuator of the present embodiment including the plurality of torsion bars whose spring constant is adjusted according to the distance from the rotation axis, the breakage of the plurality of torsion bars is suitably prevented or suppressed.

  On the other hand, since the spring constant of the torsion bar relatively close to the rotation axis can be relatively increased, the spring constant of the plurality of torsion bars as a whole can be relatively increased. As a result, the frequency of the oscillating movement of the movable part, which is determined according to the spring constant of the plurality of torsion bars as a whole, can be relatively increased.

  That is, according to the actuator of the present embodiment, it is possible to increase the frequency at which the movable part swings while preventing or suppressing the destruction of the plurality of torsion bars.

  In order to adjust the respective spring constants of the plurality of torsion bars according to the distance from the rotation axis, the width and length of the plurality of torsion bars may be appropriately adjusted as described later. Alternatively, in order to adjust the spring constant of each of the plurality of torsion bars according to the distance from the rotation axis, the density of the plurality of torsion bars may be adjusted as described later. Specifically, the density of each of the plurality of torsion bars may decrease as the distance from each of the torsion bars to the rotation axis increases. Adjustment of the density of each of the plurality of torsion bars may be realized by the presence or absence of holes formed in each of the plurality of torsion bars. Specifically, while forming one or more holes in the torsion bar relatively far from the rotation axis among the plurality of torsion bars, one or more holes are formed in the torsion bar relatively closer to the rotation axis among the plurality of torsion bars. By not forming the plurality of holes, the density of the plurality of torsion bars may be adjusted. Alternatively, the adjustment of the density of each of the plurality of torsion bars may be realized by the number of holes formed in each of the plurality of torsion bars. Specifically, while forming a relatively large number of holes in a plurality of torsion bars that are relatively far from the rotation axis, a plurality of holes are formed in a plurality of torsion bars that are relatively close to the rotation axis. The density of the plurality of torsion bars may be adjusted by forming an extremely small number of holes or not forming the holes. Alternatively, the adjustment of the density of each of the plurality of torsion bars may be realized by the size of the hole formed in each of the plurality of torsion bars. Specifically, while forming a relatively large hole in the torsion bar that is relatively far from the rotation axis among the plurality of torsion bars, the relative torsion bar that is relatively close to the rotation axis among the plurality of torsion bars is formed. The density of the plurality of torsion bars may be adjusted by forming small holes or not forming holes. Alternatively, the adjustment of the density of each of the plurality of torsion bars may be realized by a difference in the material constituting each of the plurality of torsion bars. Specifically, of the plurality of torsion bars, the torsion bar relatively far from the rotation axis is made of a material having a relatively low density, while the torsion bar relative to the rotation axis is relatively close among the plurality of torsion bars. The density of the plurality of torsion bars may be adjusted by using a material having a relatively high density.

  Further, the plurality of torsion bars may all be completely separated. Alternatively, some of the plurality of torsion bars may be connected to another adjacent torsion bar in a bridge shape along the lateral direction.

  Even when the movable portion is supported by only one torsion bar, the thickness of the torsion bar (specifically, the thickness of the torsion bar along the direction orthogonal to the longitudinal direction and the transverse direction, respectively) By adjusting (), it is also possible to increase the frequency at which the movable part swings while preventing or suppressing the destruction of the torsion bar. In this case, it is preferable to increase the thickness of the torsion bar in order to increase the frequency at which the movable portion swings while preventing or suppressing the destruction of the torsion bar. However, as described later, the movable portion, the support portion, and the torsion bar may be manufactured from a common (in other words, one) semiconductor substrate using a semiconductor manufacturing process. Therefore, in order to increase the thickness of the torsion bar, it is necessary to increase the thickness of the movable portion and the support portion. Further, as will be described in detail later, the thickness of other torsion bars for which it is not desired to increase the spring constant must be increased. However, according to the present embodiment, it is possible to increase the frequency at which the movable part swings while preventing or suppressing the destruction of the torsion bar without changing the specifications of the movable part and the support part. For this reason, the actuator of the present embodiment including a plurality of torsion bars whose spring constant is adjusted according to the distance from the rotation axis has a higher practicality than an actuator whose thickness of the torsion bar is adjusted. It is very advantageous.

  In another aspect of the actuator according to the present embodiment, the width of each of the plurality of torsion bars decreases as the distance from the rotation axis increases.

  According to this aspect, by adjusting the width of each of the plurality of torsion bars, it is possible to relatively easily realize the plurality of torsion bars whose spring constants are adjusted according to the distance from the rotation axis. it can.

  In another aspect of the actuator of the present embodiment, the length of each of the plurality of torsion bars increases as the distance from the rotation axis increases.

  According to this aspect, by adjusting the length of each of the plurality of torsion bars, it is possible to relatively easily realize the plurality of torsion bars whose spring constants are adjusted according to the distance from the rotation axis. Can be.

  As described above, in the aspect of the actuator in which the longer the torsion bar is from the rotation axis, the length of the torsion bar is longer, at least one of the plurality of torsion bars is directed from the support section toward the movable section. The at least one torsion bar may be configured to be bent at least once in a direction intersecting a direction in which the torsion bar extends.

  With this configuration, the length of at least one torsion bar can be relatively increased by making at least one torsion bar into a bent shape. Therefore, the length of each of the plurality of torsion bars can be adjusted relatively easily.

  The torsion bar has a bent shape, for example, in a direction in which the torsion bar extends from the support portion toward the movable portion (that is, in the longitudinal direction of the torsion bar or the direction of the rotation axis). Examples of the shape include a shape in which the torsion bar extends in a different direction, and then returns to the original direction, a shape in which the torsion bar extends while meandering, and a shape in which the torsion bar bends in a zigzag shape. .

  In the aspect of the actuator in which at least one torsion bar has a bent shape as described above, other than the one or two torsion bars located on the rotation axis or closest to the rotation axis among the plurality of torsion bars, At least one of the torsion bars has the bent shape, and one or two torsion bars closest to the rotation axis among the plurality of torsion bars have the bent shape. It may be configured not to.

  With this configuration, since one or two torsion bars located on or closest to the rotation axis do not have a bent shape, the torsion bar causes the movable part to swing (for example, (Rotating oscillating motion) is preferably realized. That is, by forming at least one torsion bar into a bent shape, a plurality of torsion bars whose lengths are adjusted in accordance with the distance from the rotation axis are realized, but the movable portion has a favorable distance. Movement can be realized.

  In addition, one or two torsion bars located on or closest to the rotation axis move from the support portion to the movable portion (or from the connection point between the support portion and the torsion bar to the movable portion and the torsion bar). (To the connection point of (i.e., the connection point)).

  As described above, in the aspect of the actuator in which the longer the torsion bar is from the rotation axis, the length of the torsion bar is longer, at least one of the plurality of torsion bars is directed from the support section toward the movable section. The at least one torsion bar may be configured to be folded at least once in a direction opposite to a direction in which the at least one torsion bar extends.

  According to this structure, the length of at least one torsion bar can be relatively increased by making at least one torsion bar into a folded shape. Therefore, the length of each of the plurality of torsion bars can be adjusted relatively easily.

  Note that the folded shape of the torsion bar refers to, for example, a direction in which the torsion bar extends from the support portion toward the movable portion (that is, a direction in which the torsion bar extends in the longitudinal direction or the rotation axis direction). An example is a shape in which the torsion bar is bent (ie, folded) at an angle of 90 degrees or more with respect to the direction.

  In the aspect of the actuator in which at least one torsion bar has a folded shape as described above, other than the one or two torsion bars located on the rotation axis or closest to the rotation axis among the plurality of torsion bars. At least one of the other torsion bars has the folded shape, and one or two of the plurality of torsion bars closest to the rotation axis is the folded shape. May not be provided.

  According to this structure, the one or two torsion bars located on or closest to the rotation axis do not have a folded shape. , Rotating oscillating motion) is preferably realized. In other words, while realizing a plurality of torsion bars whose length is adjusted in accordance with the distance to the rotation axis by forming the shape of at least one torsion bar into a folded shape, it is preferable that the movable portion is Harmony can be realized.

  In addition, one or two torsion bars located on or closest to the rotation axis move from the support portion to the movable portion (or from the connection point between the support portion and the torsion bar to the movable portion and the torsion bar). (To the connection point of (i.e., the connection point)).

  In another aspect of the actuator of the present embodiment, the density of each of the plurality of torsion bars decreases as the distance from each of the torsion bars to the rotation axis increases.

  According to this aspect, by adjusting the density of each of the plurality of torsion bars, it is possible to relatively easily realize the plurality of torsion bars whose spring constant is adjusted according to the distance from the rotation axis.

  As described above, in the aspect of the actuator in which the density of the torsion bar decreases as the torsion bar becomes farther from the rotation axis, at least one of the plurality of torsion bars has one or more holes formed therein. It may be configured as follows.

  According to this structure, by forming holes in at least one torsion bar, the density of at least one torsion bar can be relatively reduced. Therefore, the density of each of the plurality of torsion bars can be adjusted relatively easily.

  The “hole” in the present embodiment may be a hole (so-called opening) that penetrates the torsion bar, a hole that does not penetrate the torsion bar (so-called concave portion), or a torsion bar. (In other words, voids) formed inside (in other words, not appearing outside).

  The operation and other advantages of the present embodiment will become more apparent from the examples explained below.

  As described above, according to the actuator of the present embodiment, the movable portion, the support portion, and the plurality of torsion bars are provided, and the spring constant of each of the plurality of torsion bars is such that the torsion bars are far from the rotation axis. The smaller it becomes, the smaller it becomes. Therefore, it is possible to increase the frequency at which the movable part swings while preventing or suppressing the destruction of the torsion bar.

  Hereinafter, embodiments will be described with reference to the drawings.

(1) First Embodiment Hereinafter, an actuator 1 according to a first embodiment will be described with reference to FIG. FIG. 1 is a plan view illustrating an example of the configuration of the actuator 1 according to the first embodiment.

  As shown in FIG. 1, the actuator 1 of the first embodiment is, for example, a planar type electromagnetic drive actuator (ie, a MEMS scanner) used for scanning a laser beam. The actuator 1 includes an outer support 110, a pair of torsion bars 130, an inner support 210, a plurality of torsion bars 230, a movable portion 120, a pair of permanent magnets 160, a pair of power terminals 170, It has.

  The outer support 110, the pair of torsion bars 130, the inner support 210, the plurality of torsion bars 230, and the movable section 120 are integrally formed from a nonmagnetic substrate such as a silicon substrate. That is, a gap is formed between the outer support 110, the pair of torsion bars 130, the inner support 210, the plurality of torsion bars 230, and the movable part 120 by removing a part of a nonmagnetic substrate such as a silicon substrate. It is formed by being formed. It is preferable to use a MEMS process as the formation process at this time. Note that, instead of the silicon substrate, the outer support 110, the pair of torsion bars 130, the inner support 210, the plurality of torsion bars 230, and the movable portion 120 may be integrally formed from any elastic material. .

  The outer support 110 has a frame shape surrounding the inner support 210 and is located on both sides of the inner support 210 (in other words, sandwiches the inner support 210 from both sides of the inner support 210). The pair of torsion bars 130 is connected to the inner support 210. Although FIG. 1 shows an example in which the shape of the outer support 110 is a frame shape, it goes without saying that the shape of the outer support 110 is not limited to the frame shape. For example, the shape of the outer support 110 may be a frame shape in which a part thereof is open.

  The inner support 210 has a frame shape surrounding the movable part 120, and extends in the direction in which the pair of torsion bars 130 extend (that is, the longitudinal direction of the pair of torsion bars 130, ) Is pivotally supported on the outer support 110 by a pair of torsion bars 130 so as to be able to swing about a rotation axis along the direction. The inner support 210 is further connected to the movable part 120 by a plurality of pairs of torsion bars 230 located on both sides of the movable part 120 (in other words, sandwiching the movable part 120 from both sides of the movable part 120). The drive coil 140 is formed on the surface of the inner support 210. However, the drive coil 140 may be formed inside the inner support 210. Although FIG. 1 illustrates an example in which the shape of the inner support 210 is a frame shape, it is needless to say that the shape of the inner support 210 is not limited to the frame shape. For example, the shape of the inner support 210 may be a frame shape in which a part thereof is open.

  The movable portion 120 swings about a rotation axis along a direction in which the plurality of torsion bars 230 extend (that is, the longitudinal direction of the plurality of torsion bars 230 and the direction of the Y axis in FIG. 1). A plurality of torsion bars 230 are pivotally supported on the inner support 210 so as to be movable. A mirror (not shown) that reflects laser light is formed on the surface of the movable section 120.

  The pair of torsion bars 130 connect the inner support 210 and the outer support 110 such that the inner support 210 can swing with respect to the outer support 110. Due to the elasticity of the pair of torsion bars 130, the inner support 210 swings so as to rotate about an axis along the direction in which the pair of torsion bars 130 extend, as a rotation axis. That is, the inner support body 210 swings around the rotation axis with the X axis in FIG. 1 as the rotation axis. At this time, the movable section 120 is connected to the inner support 210 via a plurality of pairs of torsion bars 230. Accordingly, as the inner support 210 swings, the movable portion 120 swings substantially so as to rotate around the rotation axis with the X axis in FIG. 1 as the rotation axis.

  Each of the pair of torsion bars 230 connects the movable part 120 and the inner support 210 so that the movable part 120 can swing with respect to the inner support 210. Due to the elasticity of the plurality of torsion bars 230, the movable portion 120 swings so as to rotate about an axis along the direction in which the plurality of torsion bars 230 extend as a rotation axis. That is, the movable part 120 swings around the Y axis in FIG. 1 so as to rotate around the rotation axis. In addition, the plurality of pairs of torsion bars 230 are arranged so as to be arranged in parallel along the short direction of the torsion bars 230.

  The drive coil 140 is, for example, a coil that extends on the inner support 210. The drive coil 140 may be formed using, for example, a material having relatively high conductivity (for example, gold or copper). Further, the drive coil 140 may be formed using a semiconductor manufacturing process such as a plating process or a sputtering method. Alternatively, the drive coil 140 is embedded in the silicon substrate for forming the outer support 110, the pair of torsion bars 130, the inner support 210, the plurality of torsion bars 230, and the movable part 120 using an implant method. It may be. Note that, in FIG. 1, the outer shape of the drive coil 140 is simplified in order to emphasize the legibility of the drawing, but the drive coil 140 is actually formed on the surface of the inner support 210. And one or more windings.

  The drive coil 140 includes a pair of power terminals 170 formed on the outer support 110 and a wire 150 for electrically connecting the pair of power terminals 170 and the drive coil 140 and a pair of torsion. A control current is supplied from a power supply via a wiring 150 formed on the bar 130. The control current is a control current for causing the inner support 210 and the movable unit 120 to move, and typically, a signal component having a frequency synchronized with the frequency at which the inner support 210 moves and the movable unit 120 are generated. It is an alternating current including a signal component of a frequency synchronized with a oscillating frequency. Note that the power supply may be a power supply provided in the actuator 1 itself, or may be a power supply prepared outside the actuator 1.

  The pair of permanent magnets 160 are mounted outside the outer support 110. However, the pair of permanent magnets 160 may be attached to any location as long as a predetermined static magnetic field can be applied to the drive coil 140. It is preferable that the orientation of the magnetic poles of the pair of permanent magnets 160 is appropriately set so that a predetermined static magnetic field can be applied to the drive coil 140. Note that a yoke may be added to the pair of permanent magnets 160 in order to increase the strength of the static magnetic field.

  When the actuator 1 according to the first embodiment operates (specifically, the movable portion 120 moves), first, the power is supplied from the power supply to the drive coil 140 via the power supply terminal 170 and the wiring 150. A control current is supplied thereto. At this time, the control current supplied to the drive coil 140 includes a signal for oscillating the inner support 210 (specifically, a signal synchronized with the oscillating cycle of the inner support 210) and the movable unit 120. It is preferable that the current is superimposed with a signal for causing the movable part 120 to move (specifically, a signal synchronized with the cycle of the movable part 120). On the other hand, a static magnetic field is applied to the drive coil 140 by the pair of permanent magnets 160. Therefore, a force (i.e., Lorentz force) is generated in the drive coil 140 due to an electromagnetic interaction between the static magnetic field applied from the pair of permanent magnets 160 and the control current supplied to the drive coil 140. As a result, the inner support 210 on which the drive coil 140 is formed is farther away by the Lorentz force caused by the electromagnetic interaction between the static magnetic field applied from the pair of permanent magnets 160 and the control current supplied to the drive coil 140. Move. That is, the inner support 210 swings so as to rotate around the X axis in FIG. At this time, the movable section 120 is connected to the inner support 210 via a plurality of pairs of torsion bars 230. Accordingly, as the inner support 210 swings, the movable portion 120 swings substantially so as to rotate around the rotation axis with the X axis in FIG. 1 as the rotation axis.

  In addition, the Lorentz force resulting from the electromagnetic interaction between the static magnetic field applied from the pair of permanent magnets 160 and the control current supplied to the drive coil 140 is transmitted to the movable unit 120 as an inertial force. As a result, the movable section 120 swings so as to rotate around the Y axis in FIG.

  Thus, according to the actuator 1 of the first embodiment, the movable unit 120 is driven in two axes.

  In the first embodiment, the biaxial driving of the movable unit 120 is performed by moving the inner support 210 using the Lorentz force itself and moving the movable unit 120 using the Lorentz force as an inertia force. Have been done. However, a drive coil for generating Lorentz force for moving the movable portion 120 may be formed on the movable portion 120. In this case, the plurality of pairs of torsion bars 230 (further, the inner support 210, the pair of torsion bars 130, and the outer support 110) are connected to the movable portion 120 by the power supply terminal 170 on the outer support 110. It is preferable that a wiring connected to the upper drive coil is formed.

  In the first embodiment, in particular, the width of each of the plurality of pairs of torsion bars 230 (specifically, the width corresponding to the length of each of the plurality of torsion bars 230 along the lateral direction, and FIG. 1 is a rotation axis of the movable portion 120 (hereinafter, simply referred to as “rotation axis” unless otherwise specified). In this case, the adjustment is made according to the distance between the rotation axis of the movable part 120 (that is, the rotation axis along the Y axis). Hereinafter, with reference to FIG. 2, the width of each of the pair of torsion bars 230 adjusted according to the distance between each of the pair of torsion bars 230 and the rotation axis of the movable unit 120 will be described. I do. FIG. 2 is an enlarged plan view illustrating an example of the details of the shape of the pair of torsion bars 230 included in the actuator 1 of the first embodiment. Note that FIG. 2 focuses on the torsion bar 230 that is disposed on one side (for example, the upper side in FIG. 1) of the movable portion 120 among the plurality of torsion bars 230 in the description. However, the same applies to the torsion bar 230 arranged on the other side (for example, the lower side in FIG. 1) of the movable portion 120 among the plurality of torsion bars 230.

  As shown in FIG. 2, the width of each of the plurality of torsion bars 230 arranged in parallel along the short direction (the direction of the X axis) increases as the distance between the torsion bar 230 and the rotation axis increases. It has been adjusted to be thinner. That is, the width of each of the plurality of torsion bars 230 is adjusted so that the closer the distance between the torsion bar 230 and the rotation axis is, the larger the width is. In other words, the width of each of the plurality of torsion bars 230 is adjusted so that the farther the torsion bar 230 is from the rotation axis, the narrower. That is, the width of each of the plurality of torsion bars 230 is adjusted so that the closer the torsion bar 230 is to the rotation axis, the thicker the torsion bar 230 is. In other words, the width of each of the plurality of torsion bars 230 is adjusted so as to be thinner as the torsion bar 230 is farther from the rotation axis. That is, the width of each of the plurality of torsion bars 230 is adjusted such that the closer to the rotation axis the torsion bar 230 is, the thicker.

  Specifically, as shown in FIG. 2, the plurality of torsion bars 230 are (i) two torsion bars 230a whose distance from the rotation axis is D1, and (ii) a distance from the rotation axis is D2 (however, An example including two torsion bars 230b satisfying D2 <D1) and (iii) a torsion bar 230c located on the rotation axis (that is, the distance from the rotation axis is zero) will be described. At this time, assuming that the width of the torsion bar 230a is da, the width of the torsion bar 230b is db, and the width of the torsion bar 230c is dc, a plurality of torsion bars 230 are formed so that the relation da <db <dc is satisfied. The width has been adjusted.

  FIG. 1 shows an example in which the torsion bar 230c located at the center of the plurality of torsion bars 230 is located on the rotation axis. In this case, the distance between the torsion bar 230 and the rotation axis depends on whether the torsion bar 230 is located relatively toward the center or outside in the arrangement of the plurality of torsion bars 230. Become. Therefore, when the torsion bar 230c located at the center of the plurality of torsion bars 230 is located on the rotation axis, the width of each of the plurality of torsion bars 230 is a relative width of the array along the short direction. It can be said that the width of the torsion bar 230 (for example, the torsion bar 230a) positioned outside is adjusted to be smaller than the width of the torsion bar (for example, the torsion bar 230c) positioned relatively on the center side. . In other words, it can be said that the width of each of the plurality of torsion bars 230 is adjusted so that the width of each torsion bar 230 located relatively outside the arrangement along the short direction becomes narrower.

  Preferably, the plurality of torsion bars 230 are arranged so as to be line-symmetric with respect to the rotation axis of the movable section 120. At this time, when the actuator 1 includes an odd number of torsion bars 230, it is preferable that one of the center of the odd number of torsion bars 230 is located on the rotation axis. Alternatively, when the actuator 1 includes an even number of torsion bars 230, the center two torsion bars 230 of the even number of torsion bars 230 are arranged at positions that are line-symmetric with respect to the rotation axis. Preferably.

  Here, the spring constant of the torsion bar 230 decreases as the width of the torsion bar 230 decreases. In other words, the spring width of the torsion bar 230 increases as the width of the torsion bar 230 increases. For this reason, according to the actuator 1 of the first embodiment, by adjusting the width of each of the plurality of torsion bars 230, the spring constant of each of the plurality of torsion bars 230 is increased. The smaller the distance between them, the smaller the distance. In other words, the spring constant of each of the plurality of torsion bars 230 increases as the distance between the torsion bar 230 and the rotation axis decreases. In other words, the spring constant of each of the plurality of torsion bars 230 decreases as the torsion bar 230 moves away from the rotation axis. That is, the spring constant of each of the plurality of torsion bars 230 is adjusted so as to increase as the torsion bar 230 approaches the rotation axis. In other words, the spring constant of each of the plurality of torsion bars 230 is adjusted to be smaller as the torsion bar 230 is farther from the rotation axis. That is, the spring constant of each of the plurality of torsion bars 230 is adjusted so that the closer to the rotation axis the torsion bar 230 is.

  Here, in order to explain the technical effect of the actuator 1 of the first embodiment including the plurality of torsion bars 230 whose widths are adjusted according to the distance from the rotation axis, referring to FIG. The actuator according to the comparative example in which the movable portion 120 is rotated by using only one torsion bar 1230 located at the position shown in FIG. FIG. 3 is an enlarged plan view illustrating an example of a configuration of an actuator of a comparative example in which the movable section 120 is rotated using only one torsion bar 1230 located on the rotation axis.

  As shown in FIG. 3, in the actuator of the comparative example, when the movable portion 120 moves far, the edge portions on both sides of the torsion bar 1230 (more specifically, both sides along the short direction of the torsion bar 230). The stress applied to the central portion (more specifically, the central portion along the short direction of the torsion bar) is larger than the stress applied to the central portion (more specifically, the central portion along the lateral direction of the torsion bar). . That is, the stress applied to the edge portion of the torsion bar 1230 relatively far from the rotation axis becomes larger than the stress applied to the center portion of the torsion bar 1230 relatively close to the rotation axis. That is, the stress applied to the torsion bar 1230 as the movable portion 120 moves farther becomes more likely to be applied as the distance from the rotation axis increases.

  Considering how such stress is applied, the actuator 1 according to the first embodiment including the plurality of torsion bars 230 having a smaller width as the distance from the rotation axis becomes smaller (that is, a smaller spring constant). For example, stress is likely to be applied to the torsion bar 230 relatively far from the rotation axis (that is, the torsion bar 230 having a relatively small width and a relatively small spring constant). However, since the spring constant is relatively small because the width is relatively small, the stress applied to the torsion bar 230 relatively far from the rotation axis is reduced. In other words, the spring constant is relatively small due to the relatively small width, so that the torsion bar 230 relatively far from the rotation axis is relatively soft, and as a result, the torsion bar 230 relatively far from the rotation axis is relatively small. The stress applied to 230 is reduced. Therefore, destruction of the torsion bar 230 relatively far from the rotation axis is suitably prevented or suppressed.

  On the other hand, a relatively large stress is not applied to the torsion bar 230 relatively close to the rotation axis (that is, the torsion bar 230 having a relatively large width and a relatively large spring constant). . Therefore, the destruction of the torsion bar 230 relatively close to the rotation axis is also suitably prevented or suppressed. In other words, the spring constant is relatively large because the width is relatively large, so that the torsion bar 230 relatively close to the rotation axis is relatively hard. However, since a large stress is not applied to the torsion bar 230 relatively close to the rotation axis, breakage of the torsion bar 230 relatively close to the rotation axis is also suitably prevented or suppressed.

  As described above, according to the actuator 1 of the first embodiment, the widths (or spring constants) of the plurality of torsion bars 230 are adjusted according to the distance from the rotation axis. Destruction is suitably prevented or deterred.

  In addition, according to the actuator 1 of the first embodiment, it is possible to make the width of the torsion bar 230 relatively close to the rotation axis relatively large while preventing or suppressing the destruction of the plurality of torsion bars 230 ( That is, the spring constant can be relatively increased. In the actuator of the comparative example shown in FIG. 3, although the spring constant of the torsion bar 1230 can be increased by increasing the width of the torsion bar 1230, the torsion bar 1230 is increased by the increased width. 1230 is easily broken. However, according to the actuator 1 of the first embodiment, taking into account the trade-off relationship between the destruction of the torsion bar 230 and the increase in the spring constant of the torsion bar 230, the destruction of the plurality of torsion bars 230 is prevented. While preventing or suppressing, the width of the torsion bar 230 relatively far from the rotation axis can be relatively narrow while the width of the torsion bar 230 relatively close to the rotation axis can be relatively large. Therefore, the spring constant of the plurality of torsion bars 230 as a whole can be relatively increased. As a result, it is possible to relatively increase the frequency of swaying of the movable portion 120 determined according to the spring constant of the plurality of torsion bars 230 as a whole. In particular, when the actuator 1 according to the first embodiment is applied to a video display device such as a head-up display, the swaying caused by the elasticity of the pair of torsion bars 130 (that is, the swaying using the X axis as the rotation axis) ) To realize vertical scanning, and also realize horizontal scanning by swaying caused by the elasticity of the plurality of torsion bars 230 (that is, swaying with the Y axis as a rotation axis). In this case, in order to increase the resolution of the image, it is preferable to increase the frequency of the sway (that is, the sway with the Y axis as the rotation axis) caused by the elasticity of the pair of torsion bars 230. Therefore, according to the actuator 1 of the first embodiment, the spring constant of the plurality of pairs of torsion bars 230 as a whole can be relatively increased. (I.e., the oscillating motion with the Y axis as the rotation axis) can be increased in frequency. As a result, it is possible to increase the frequency at which the movable portion 120 swings due to the elasticity of the pair of torsion bars 230.

  As described above, according to the actuator 1 of the first embodiment, it is possible to increase the frequency at which the movable unit 120 moves while preventing or suppressing the destruction of the plurality of torsion bars 230.

  Note that the actuator 1 includes a plurality of torsion bars 130 (ie, a plurality of torsion bars 230) whose widths are adjusted in accordance with the distance from the rotation axis of the inner support 210, instead of the pair of torsion bars 130. Torsion bar). That is, instead of the pair of torsion bars 130, the actuator 1 may include a plurality of pairs of torsion bars 130 whose width decreases as the distance from the rotation axis of the inner support 210 increases. Alternatively, when the actuator 1 includes a plurality of pairs of torsion bars 130 whose widths are adjusted according to the distance of the inner support 210 from the rotation axis, the width is determined according to the distance of the movable unit 120 from the rotation axis. A pair of torsion bars 230 (that is, a torsion bar similar to the pair of torsion bars 130) may be provided instead of the pair of torsion bars 230 in which is adjusted.

(2) Second Embodiment Next, an actuator 2 according to a second embodiment will be described with reference to FIG. FIG. 4 is an enlarged plan view illustrating an example of the details of the shape of the pair of torsion bars 230 included in the actuator 2 of the second embodiment. The same components as those included in the actuator 1 of the first embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.

  As shown in FIG. 4, in the actuator 2 of the second embodiment, as compared with the actuator 1 of the first embodiment, the widths of the plurality of pairs of torsion bars 230 are adjusted according to the distance from the rotation axis. Instead of this, the length of the plurality of pairs of torsion bars 230 (specifically, the length along the longitudinal direction of each of the pair of torsion bars 230) according to the distance from the rotation axis. Are different in that they have been adjusted. The other components of the actuator 2 of the second embodiment may be the same as the other components of the actuator 1 of the first embodiment.

  Specifically, as shown in FIG. 4, in the second embodiment, the length of each of the plurality of torsion bars 230 arranged in parallel along the short direction (X-axis direction) is It is adjusted so that the longer the distance between 230 and the rotation axis, the longer. That is, the length of each of the plurality of torsion bars 230 is adjusted to be shorter as the distance between the torsion bar 230 and the rotation axis is shorter. In other words, the length of each of the plurality of torsion bars 230 is adjusted to be longer as the torsion bar 230 is farther from the rotation axis. That is, the length of each of the plurality of torsion bars 230 is adjusted so that the closer the torsion bar 230 is to the rotation axis, the shorter the length. In other words, the length of each of the plurality of torsion bars 230 is adjusted to be longer as the torsion bar 230 is farther from the rotation axis. That is, the length of each of the plurality of torsion bars 230 is adjusted to be shorter as the torsion bar 230 is closer to the rotation axis.

  Specifically, as shown in FIG. 4, the plurality of torsion bars 230 are (i) two torsion bars 230a whose distance from the rotation axis is D1, and (ii) a distance from the rotation axis is D2 (however, An example including two torsion bars 230b satisfying D2 <D1) and (iii) a torsion bar 230c located on the rotation axis (that is, the distance from the rotation axis is zero) will be described. At this time, when the length of the torsion bar 230a is La, the length of the torsion bar 230b is Lb, and the length of the torsion bar 230c is Lc, a plurality of torsion bars are set so that the relationship of La> Lb> Lc is established. The length of the bar 230 has been adjusted.

  When the center torsion bar 230c is located on the rotation axis, the length of each of the plurality of torsion bars 230 is relatively outside the torsion bar 230 (for example, , The length of the torsion bar 230a) is adjusted so as to be longer than the length of the torsion bar (for example, the torsion bar 230c) positioned relatively on the center side.

  Here, as the length of the torsion bar 230 increases, the spring constant of the torsion bar 230 decreases. In other words, the shorter the length of the torsion bar 230, the greater the spring constant of the torsion bar 230. For this reason, according to the actuator 2 of the second embodiment, the spring constant of each of the plurality of torsion bars 230 is adjusted by adjusting the length of each of the plurality of torsion bars 230, and The greater the distance between, the smaller. Therefore, even with the actuator 2 of the second embodiment, various effects that can be enjoyed by the actuator 1 of the first embodiment can be suitably enjoyed.

(3) Third Embodiment Next, an actuator 3 according to a third embodiment will be described with reference to FIG. FIG. 5 is an enlarged plan view illustrating an example of the details of the shape of a pair of torsion bars 230 included in the actuator 3 of the third embodiment. Note that the same components as those included in the actuator 1 of the first embodiment to the actuator 2 of the second embodiment are denoted by the same reference numerals, and a detailed description thereof will be omitted.

  As shown in FIG. 5, in the actuator 3 of the third embodiment, as compared with the actuator 1 of the first embodiment, the width of the plurality of pairs of torsion bars 230 is adjusted according to the distance between the rotation axis and the actuator 1. In addition, the length of the pair of torsion bars 230 according to the distance from the rotation axis (specifically, the length along the longitudinal direction of each of the pair of torsion bars 230) Are different in that they have been adjusted. That is, the actuator 3 of the third embodiment corresponds to an actuator in which the components of the actuator 1 of the first embodiment and the components of the actuator 2 of the second embodiment are combined. The other components of the actuator 3 of the third embodiment may be the same as the other components of the actuator 1 of the first embodiment.

  Even with such an actuator 3 of the third embodiment, various effects that can be enjoyed by the actuator 1 of the first embodiment and the actuator 2 of the second embodiment can be suitably enjoyed. In particular, according to the actuator 3 of the third embodiment, since both the width and the length of the plurality of torsion bars 230 are adjusted, the spring constant of the plurality of torsion bars 230 can be adjusted with higher accuracy. .

(4) Fourth Embodiment Next, an actuator 4 according to a fourth embodiment will be described with reference to FIG. FIG. 6 is an enlarged plan view illustrating an example of the details of the shape of the pair of torsion bars 230 included in the actuator 4 of the fourth embodiment. Note that the same components as those included in the actuators 1 to 3 of the first embodiment to the actuators 3 of the third embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.

  As shown in FIG. 6, the actuator 4 of the fourth embodiment is different from the actuator 2 of the second embodiment in that each of the plurality of torsion bars 230 bites into both the movable part 120 and the inner support 210. They differ in that they have a shape. The other components of the actuator 4 of the fourth embodiment may be the same as the other components of the actuator 2 of the second embodiment.

  More specifically, a notch for adjusting the length of each of the plurality of torsion bars 230 is formed in a region on the movable unit 120 where the movable unit 120 and each of the plurality of torsion bars 230 are connected. ing. That is, in the second embodiment and the third embodiment, the region that forms a part of the movable portion 120 is replaced by the region that forms a part of the plurality of torsion bars 230 in the fourth embodiment (that is, a plurality of (Area part for increasing the length of the torsion bar 230).

Similarly, a cutout for adjusting the length of each of the plurality of torsion bars 230 is formed in a region on the inner support 210 where the inner support 210 and each of the plurality of torsion bars 230 are connected. I have. That is, in the second embodiment and the third embodiment, the region that forms a part of the inner support 210 is changed to the region that forms a part of the plurality of torsion bars 230 in the fourth embodiment (that is, the region part). Even though the actuator 4 of the fourth embodiment is treated as an area for increasing the length of the plurality of torsion bars 230, various types of actuators 2 that can be enjoyed by the actuator 2 of the second embodiment The effect can be suitably enjoyed. In particular, the actuator 4 according to the fourth embodiment has a shape in which the inner support 210 and the movable portion 120 project or protrude toward the plurality of torsion bars 230 in order to adjust the length of the plurality of torsion bars 230. (Refer to the shapes of the inner support 210 and the movable portion 120 in FIGS. 4 and 5).

  FIG. 6 illustrates the actuator 4 having such a shape that each of the plurality of torsion bars 230 bites into both the movable part 120 and the inner support 210. However, the actuator 4 may have a shape such that at least one of the plurality of torsion bars 230 bites into at least the movable portion 120 and the inner support 210.

(5) Fifth Embodiment Next, an actuator 5 according to a fifth embodiment will be described with reference to FIG. FIG. 7 is an enlarged plan view illustrating an example of the details of the shape of the pair of torsion bars 230 included in the actuator 5 of the fifth embodiment. The same components as those included in the actuators 1 to 4 of the first embodiment are denoted by the same reference numerals, and the detailed description thereof will be omitted.

  As shown in FIG. 7, in the actuator 5 of the fifth embodiment, at least a part of the plurality of torsion bars 230 is moved from the inner support 210 to the movable part 120 as compared with the actuator 2 of the second embodiment. The difference is that not only does it extend in the direction toward it (the direction of the Y axis in FIG. 7), but it also extends in the direction bent from that direction (the direction of the X axis in FIG. 7). The other components of the actuator 5 of the fifth embodiment may be the same as the other components of the actuator 2 of the second embodiment.

  FIG. 7 shows an example in which the actuator 5 has an odd number of torsion bars 230. In this case, it is preferable that one torsion bar 230c at the center of the odd number of torsion bars 230 extends only in the direction from the inner support 210 toward the movable portion 120. That is, it is preferable that one torsion bar 230c at the center of the odd number of torsion bars 230 does not extend in a direction bent from the direction from the inner support 210 toward the movable portion 120. FIG. 7 shows an example in which one of the odd number of torsion bars 230 is located on the rotation axis at the center. However, when one torsion bar 230 at the center of the plurality of torsion bars 230 is disposed at a position off the rotation axis of the movable unit 120, one torsion bar 230 closest to the rotation axis is It preferably extends only in the direction from the support 210 toward the movable part 120. Alternatively, when one of the torsion bars 230 at the center of the plurality of torsion bars 230 is disposed at a position off the rotation axis of the movable portion 120, the torsion bar 230 is closest to the rotation axis and is line-symmetric with respect to the rotation axis. It is preferable that at least two torsion bars 230 extend only in the direction from the inner support 210 toward the movable part 120.

  Even with the actuator 5 of the fifth embodiment, various effects that can be enjoyed by the actuator 2 of the second embodiment can be suitably enjoyed. In particular, according to the actuator 5 of the fifth embodiment, it is possible to suitably adjust the length of the plurality of torsion bars 230 while suppressing an increase in the space occupied by the plurality of torsion bars 230.

  In addition, according to the actuator 5 of the fifth embodiment, one torsion bar 230 located on or closest to the rotation axis does not have a bent shape. For this reason, the hardness of the plurality of torsion bars 230 as a whole in a direction other than the rotation direction of the movable unit 120 is relatively hardened due to the presence of the torsion bar 230 that does not have a bent shape. Can be. However, one torsion bar 230 located on or closest to the rotation axis may have a bent shape.

(6) Sixth Embodiment Next, an actuator 6 according to a sixth embodiment will be described with reference to FIG. FIG. 8 is an enlarged plan view illustrating an example of the details of the shape of the pair of torsion bars 230 included in the actuator 6 of the sixth embodiment. Note that the same components as those included in the actuators 1 to 5 of the first embodiment to the actuators 5 of the fifth embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.

  As shown in FIG. 8, the actuator 6 of the sixth embodiment is different from the actuator 5 of the fifth embodiment in that the actuator 6 has an even number of torsion bars 230. The other components of the actuator 6 of the sixth embodiment may be the same as the other components of the actuator 5 of the fifth embodiment.

  In this case, it is preferable that the two torsion bars 230c at the center of the even number of torsion bars 230 extend only in the direction from the inner support 210 toward the movable portion 120. That is, it is preferable that the two torsion bars 230c at the center of the even number of torsion bars 230 do not extend in the direction bent from the direction from the inner support 210 toward the movable portion 120. FIG. 8 shows an example in which the center two torsion bars 230c of the even number of torsion bars 230 are located closest to the rotation axis. However, when the other torsion bar 230 other than the center two torsion bars 230 of the plurality of torsion bars 230 is located at the position closest to the rotation axis, one torsion bar 230 closest to the rotation axis is It preferably extends only in the direction from the inner support 210 to the movable part 120. Alternatively, when another torsion bar 230 other than the center two torsion bars 230 of the plurality of torsion bars 230 is located at a position closest to the rotation axis, the torsion bar is closest to the rotation axis and a line with respect to the rotation axis. It is preferable that at least two symmetrical torsion bars 230 extend only in a direction from the inner support 210 toward the movable portion 120.

  Even with the actuator 6 of the sixth embodiment, various effects that can be enjoyed by the actuator 5 of the fifth embodiment can be suitably enjoyed. In addition, according to the actuator 6 of the sixth embodiment, even in the case where the actuator 6 includes the even number of torsion bars 230, the rotation direction of the movable portion 120 is the same as in the actuator 5 of the fifth embodiment. The hardness as a whole of the plurality of torsion bars 230 in directions other than the above can be relatively hardened. However, the two torsion bars 230 located on or closest to the rotation axis may have a bent shape.

(7) Seventh Embodiment Next, an actuator 7 according to a seventh embodiment will be described with reference to FIG. FIG. 9 is an enlarged plan view illustrating an example of the details of the shape of the pair of torsion bars 230 included in the actuator 7 of the seventh embodiment. The same components as those of the actuator 1 of the first embodiment to the actuators 6 of the sixth embodiment are denoted by the same reference numerals, and a detailed description thereof will be omitted.

  As shown in FIG. 9, in the actuator 7 of the seventh embodiment, at least a part of the plurality of torsion bars 230 is moved from the inner support 210 to the movable part 120 as compared with the actuator 2 of the second embodiment. In addition to extending in the direction (direction from top to bottom in FIG. 7), the direction opposite to the direction (direction from bottom to top in FIG. 7) or the direction folded back when viewed from this direction (That is, the returned direction which has an angle of at least 90 ° or more with respect to the direction and is the direction from the bottom to the top in FIG. 7). I have. Other components of the actuator 7 of the seventh embodiment may be the same as the other components of the actuator 2 of the second embodiment.

  FIG. 9 shows an example in which the actuator 7 has an odd number of torsion bars 230. Therefore, also in the actuator 7 of the seventh embodiment, similarly to the actuator 5 of the fifth embodiment, one torsion bar 230 closest to the rotation axis extends only in the direction from the inner support 210 to the movable part 120. Is preferred. However, when the actuator 7 has an even number of torsion bars 230, the two torsion bars 230c at the center closest to the rotation axis are movable from the inner support 210, as in the actuator 6 of the sixth embodiment. It preferably extends only in the direction toward the part 120.

  Even with the actuator 7 of the seventh embodiment, various effects that can be enjoyed by the actuator 2 of the second embodiment can be suitably enjoyed. In particular, according to the actuator 7 of the seventh embodiment, it is possible to adjust the lengths of the plurality of torsion bars 230 while suppressing an increase in the space occupied by the plurality of torsion bars 230.

  In addition, according to the actuator 7 of the seventh embodiment, one torsion bar 230 located on or closest to the rotation axis does not have a folded shape. Therefore, due to the presence of the torsion bar 230 having no folded shape, the hardness of the plurality of torsion bars 230 as a whole in a direction other than the rotation direction of the movable unit 120 is relatively hardened. be able to. However, one torsion bar 230 located on or closest to the rotation axis may have a folded shape.

(8) Eighth Embodiment Next, an actuator 8 according to an eighth embodiment will be described with reference to FIG. FIG. 10 is an enlarged plan view illustrating an example of the details of the shape of the pair of torsion bars 230 included in the actuator 8 of the eighth embodiment. Note that the same components as those included in the actuators 1 to 7 of the first embodiment to the actuators 7 of the seventh embodiment are denoted by the same reference numerals, and a detailed description thereof will be omitted.

  As shown in FIG. 10, in the actuator 8 of the eighth embodiment, as compared with the actuator 1 of the first embodiment, the widths of the plurality of pairs of torsion bars 230 are adjusted according to the distance from the rotation axis. Instead, the difference is that the density of the plurality of pairs of torsion bars 230 is adjusted according to the distance from the rotation axis. The other components of the actuator 8 of the eighth embodiment may be the same as the other components of the actuator 1 of the first embodiment.

  Specifically, in the eighth embodiment, the density of each of the plurality of torsion bars 230 arranged in parallel along the short direction (the direction of the X-axis) is determined by determining the density between the torsion bar 230 and the rotation axis. It is adjusted so that it becomes smaller as the distance increases. That is, the density of each of the plurality of torsion bars 230 is adjusted so as to increase as the distance between the torsion bar 230 and the rotation axis decreases. In other words, the density of each of the plurality of torsion bars 230 is adjusted so as to be smaller as the torsion bar 230 is farther from the rotation axis. That is, the density of each of the plurality of torsion bars 230 is adjusted so that the closer the torsion bar 230 is to the rotation axis, the higher the density. In other words, the density of each of the plurality of torsion bars 230 is adjusted so as to decrease as the torsion bar 230 is farther from the rotation axis. That is, the respective densities of the plurality of torsion bars 230 are adjusted so as to increase as the torsion bars 230 are closer to the rotation axis.

  In the eighth embodiment, holes 231 are formed in at least one of the plurality of torsion bars 230 in order to adjust the density of each of the plurality of torsion bars 230. The hole 231 may be a hole 231 (so-called opening) penetrating the torsion bar 230, a hole 231 (so-called concave portion) not penetrating the torsion bar 230, or a hole 231 of the torsion bar 230. It may be a hole 231 (so-called void) formed inside (in other words, not appearing outside). In particular, the number of holes 231 formed in each of the plurality of torsion bars 230 may decrease as the distance between the torsion bar 230 and the rotation axis increases. Accordingly, the density of each of the plurality of torsion bars 230 decreases as the distance between the torsion bar 230 and the rotation axis increases.

  Here, the spring constant of the torsion bar 230 decreases as the density of the torsion bar 230 decreases. In other words, the higher the density of the torsion bar 230, the higher the spring constant of the torsion bar 230. For this reason, according to the actuator 8 of the eighth embodiment, the spring constant of each of the plurality of torsion bars 230 is adjusted by adjusting the density of each of the plurality of torsion bars 230. The smaller the distance between them, the smaller the distance. Therefore, even with the actuator 8 of the eighth embodiment, various effects that can be enjoyed by the actuator 1 of the first embodiment can be suitably enjoyed.

  FIG. 8 shows that the number of holes 231 formed in each of the plurality of torsion bars 230 is reduced as the distance between the torsion bar 230 and the rotation axis becomes longer, so that the distance between the rotation axis and the rotation axis is reduced. An example is shown in which the density of a plurality of pairs of torsion bars 230 is adjusted according to the distance. However, by increasing the size (for example, diameter, depth, etc.) of the hole 231 formed in each of the plurality of torsion bars 230 as the distance between the torsion bar 230 and the rotation axis increases, The density of the plurality of pairs of torsion bars 230 may be adjusted according to the distance from the rotation axis. Alternatively, by changing the material constituting each of the plurality of torsion bars 230, the density of the pair of torsion bars 230 may be adjusted according to the distance from the rotation axis. Alternatively, the density of the plurality of pairs of torsion bars 230 may be adjusted according to the distance from the rotation axis using some other method. In any case, various effects that can be enjoyed by the actuator 1 of the first embodiment can be suitably enjoyed.

(9) Ninth Embodiment Next, an actuator 9 according to a ninth embodiment will be described with reference to FIG. FIG. 11 is a plan view showing an example of the configuration of the actuator 9 of the ninth embodiment. Note that the same components as those included in the actuators 1 to 8 of the first embodiment to the actuators 8 of the eighth embodiment are denoted by the same reference numerals, and a detailed description thereof will be omitted.

  As shown in FIG. 11, the actuator 9 of the ninth embodiment is different from the actuator 2 of the second embodiment in that each of the plurality of torsion bars 230 has a different extension mode. The other components of the actuator 9 of the ninth embodiment may be the same as the other components of the actuator 1 of the first embodiment.

  Specifically, of the plurality of torsion bars 230, the torsion bar 232 relatively close to the rotation axis extends linearly from the movable part 120 toward the inner support 210. On the other hand, among the plurality of torsion bars 230, the torsion bar 233 relatively far from the rotation axis extends in a curved line or a broken line along the outer edge inside the inner support 210.

  Even with such an actuator 9 of the ninth embodiment, various effects that can be enjoyed by the actuator 2 of the second embodiment can be suitably enjoyed.

(10) Tenth Embodiment Next, an actuator 10 according to a tenth embodiment will be described with reference to FIG. FIG. 12 is a plan view illustrating an example of the configuration of the actuator 10 according to the tenth embodiment. Note that the same components as those included in the actuators 1 to 9 of the first embodiment to the actuators 9 of the ninth embodiment are denoted by the same reference numerals, and a detailed description thereof will be omitted.

  As shown in FIG. 12, the actuator 10 of the tenth embodiment is different from the actuator 1 of the first embodiment in which the movable unit 120 is driven in two axes in that the movable unit 120 is driven in one axis. ing. Specifically, the actuator 10 of the tenth embodiment includes an outer support 110, a plurality of pairs of torsion bars 230, a movable part 120, a pair of permanent magnets 160, and a pair of power terminals 170. I have. That is, the actuator 10 of the tenth embodiment is different from the actuator 1 of the first embodiment in that the actuator 10 of the tenth embodiment does not include the pair of torsion bars 130 and the inner support 210.

  The outer support 110, the plurality of torsion bars 230, and the movable part 120 are integrally formed from a non-magnetic substrate such as a silicon substrate. That is, the outer support 110, the plurality of torsion bars 230, and the movable part 120 are formed by forming a gap by removing a part of a nonmagnetic substrate such as a silicon substrate. It is preferable to use a MEMS process as the formation process at this time. Note that, instead of the silicon substrate, the outer support 110, the plurality of pairs of torsion bars 230, and the movable portion 120 may be integrally formed from any elastic material.

  The outer support 110 has a frame shape that surrounds the movable part 120, and is located on both sides of the movable part 120 (in other words, a plurality of pairs of a plurality of pairs that sandwich the movable part 120 from both sides of the movable part 120). The torsion bar 230 is connected to the movable unit 120.

  The movable portion 120 swings about a rotation axis along a direction in which the plurality of torsion bars 230 extend (that is, a longitudinal direction of the pair of torsion bars 230 and a direction of the X axis in FIG. 12). A plurality of torsion bars 230 are pivotally supported on the outer support 110 so as to be movable. A mirror (not shown) that reflects laser light is formed on the surface of the movable section 120. A drive coil 140 is formed on the surface of the movable section 120. However, the drive coil 140 may be formed inside the movable part 120.

  Each of the pair of torsion bars 230 connects the movable part 120 and the outer support 110 so that the movable part 120 can swing with respect to the outer support 110. Due to the elasticity of the plurality of torsion bars 230, the movable portion 120 swings so as to rotate about an axis along the direction in which the plurality of torsion bars 230 extend as a rotation axis. That is, the movable unit 120 swings around the rotation axis with the X axis in FIG. 12 as the rotation axis.

  The drive coil 140 includes a pair of power terminals 170 formed on the outer support 110 and a wiring 150 for electrically connecting the pair of power terminals 170 and the drive coil 140. A control current is supplied from a power supply via a wiring 150 formed on the torsion bar 230 of FIG. The control current is a control current for moving the movable portion 120, and is typically an alternating current including a signal component having a frequency synchronized with the frequency at which the movable portion 120 moves. Note that the power supply may be a power supply provided in the actuator 1 itself, or may be a power supply prepared outside the actuator 1.

  When the actuator 10 according to the tenth embodiment operates (specifically, the movable part 120 moves), first, the power is supplied from the power supply to the drive coil 140 via the power supply terminal 170 and the wiring 150. A control current is supplied thereto. At this time, the control current supplied to the drive coil 140 is a current including a signal for moving the movable section 120 (specifically, a signal synchronized with the cycle of the movable section 120). Is preferred. On the other hand, a static magnetic field is applied to the drive coil 140 by the pair of permanent magnets 160. Therefore, a force (i.e., Lorentz force) is generated in the drive coil 140 due to an electromagnetic interaction between the static magnetic field applied from the pair of permanent magnets 160 and the control current supplied to the drive coil 140. As a result, the movable part 120 in which the drive coil 140 is formed swings by Lorentz force caused by an electromagnetic interaction between the static magnetic field applied from the pair of permanent magnets 160 and the control current supplied to the drive coil 140. I do. That is, the movable unit 120 swings so as to rotate around the X axis in FIG.

  As described above, according to the actuator 10 of the tenth embodiment, the one-axis driving of the movable unit 120 is performed. The actuator 10 that performs one-axis driving of the movable portion 120 also includes the plurality of pairs of torsion bars 230, so that various effects that can be enjoyed by the actuator 1 of the first embodiment can be suitably enjoyed. can do.

  Note that some of the components described in the first to tenth embodiments may be appropriately combined. Even in this case, an actuator obtained by appropriately combining some of the components described in the first to tenth embodiments can suitably enjoy the various effects described above.

  The present invention is not limited to the above-described embodiment, but can be appropriately modified without departing from the spirit or spirit of the invention which can be read from the claims and the entire specification. It is within the technical scope of the invention.

110 outer supporting part 210 inner supporting part 120 movable part 130 torsion bar 230 torsion bar 231 hole 140 drive coil 150 wiring 160 permanent magnet

Claims (1)

A support section for supporting the movable section,
A plurality of torsion bars connecting the movable portion and the support portion so as to swing the movable portion around a rotation axis along a longitudinal direction,
The plurality of torsion bars are arranged line-symmetrically with respect to the rotation axis along the short direction of the torsion bar,
The width of each of the plurality of torsion bars in the short direction is narrower as the torsion bar is farther from the rotation axis, and the thickness of each of the plurality of torsion bars in the direction perpendicular to the longitudinal direction and the short direction is one. Actuator.

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