JP2009195053A - Actuator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an actuator in which a plurality of layers of piezoelectric elements and electrodes are stacked, and the respective piezoelectric elements are displaced for improved driving force of the actuator. <P>SOLUTION: First electrode layers 5A-5D, first piezoelectric element layers 6A and 6B, second electrode layers 7A-7D, second piezoelectric element layers 8A and 8B, and third electrode layers 9A-9D are sequentially stacked in a predetermined region on a base material 4. When driving an actuator 1, the second electrode layer 7A is grounded while the first electrode layer 5A and the third electrode layer 9A are applied with AC voltages in antiphases respectively. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an actuator in which a plurality of electrode layers and piezoelectric element layers are stacked.

Conventionally, various actuators have been proposed in which a piezoelectric element or the like is laminated on a base material formed using an elastic material such as silicon.
For example, in the actuator described in Patent Document 1, a reflection mirror part is arranged at the center of a rectangular frame, and both sides of the reflection mirror part and the frame are two elastic parts. Connected to form a main body. In addition, an upper electrode, a piezoelectric element, and a lower electrode are formed across the two elastic parts and the frame body on both sides of the reflection mirror part of the main body part. And it is comprised so that a reflective mirror part can be driven to a perpendicular | vertical direction with respect to a reflective surface by applying a drive voltage between this upper electrode and a lower electrode.
JP 2006-320089 A (paragraphs (0060) to (0063), FIG. 4)

Here, in the above actuator, when the upper electrode, the piezoelectric element, and the lower electrode are formed, the lower electrode layer, the piezoelectric element layer, and the upper electrode layer are applied to a predetermined region of the silicon base material that is previously formed into a predetermined shape. It forms by laminating in order. Then, the lower electrode is grounded and an AC voltage is applied to the upper electrode. Thereby, the piezoelectric element layer between the lower electrode layer and the upper electrode layer is displaced.
Here, FIG. 17 is an explanatory view for explaining the displacement operation of the piezoelectric element layer. As shown in FIG. 17A, when the lower electrode is grounded and no voltage is applied to the upper electrode, no stress is generated in the piezoelectric element layer 301 and no displacement is performed.
On the other hand, when a positive voltage is applied to the upper electrode, as shown in FIG. 17B, an electric field is applied to the piezoelectric element layer 301 so that the piezoelectric element layer 301 is perpendicular to the upper electrode and the lower electrode. Extend in the direction. At this time, the piezoelectric element layer 301 is displaced so as to shrink isotropically in a plane parallel to the upper electrode and the lower electrode.
When a negative voltage is applied to the upper electrode, as shown in FIG. 17C, an electric field is applied to the piezoelectric element layer 301 so that the piezoelectric element layer 301 is perpendicular to the upper electrode and the lower electrode. Shrink in the direction. At this time, the piezoelectric element layer 301 is displaced so as to extend isotropically in a plane parallel to the upper electrode and the lower electrode.
On the other hand, since the base material 302 on which the reflection mirror portion is formed does not expand or contract by voltage application, the expansion (contraction) in the plane parallel to the upper electrode and the lower electrode of the piezoelectric element layer 301 formed on the upper surface Causes bending deformation downward (upward). As a result, the reflecting mirror portion formed on the base material 302 is displaced in the direction perpendicular to the reflecting surface.

  Here, in the actuator described in Patent Document 1, only one set of electrodes to which an electric field is applied is formed across the piezoelectric element, and the displaced piezoelectric element is a single layer disposed between the set of electrodes. It was only a piezoelectric element. Therefore, the displacement amount of the piezoelectric element is small, and the driving force of the actuator cannot be secured sufficiently.

  Therefore, the present invention has been made to solve the above-described problems, and the driving force of the actuator has been improved by stacking a plurality of layers of piezoelectric elements and electrodes and displacing each piezoelectric element. An object is to provide an actuator.

  In order to achieve the above object, an actuator according to claim 1 includes a support portion including at least two pairs of beams, and a movable portion that is swingably supported via the support portion, and applies a voltage. An actuator for swinging the movable part by the first layer electrode formed from an electrode layer laminated separately for each beam on the support part, and laminated on the first layer electrode A first layer piezoelectric element formed from a piezoelectric element layer, a second layer electrode formed from an electrode layer laminated separately on each beam on the first layer piezoelectric element, and on the second layer electrode A second layer piezoelectric element formed from stacked piezoelectric element layers; and a third layer electrode formed from an electrode layer stacked separately on each beam on the second layer piezoelectric element. Features.

  The actuator according to claim 2 is the actuator according to claim 1, wherein the support portion has a flat plate shape, and the first layer electrode, the first layer piezoelectric element, the second layer electrode, and the first layer electrode. The two-layer piezoelectric element and the third layer electrode are formed on both surfaces of the support portion.

  An actuator according to claim 3 is the actuator according to claim 1 or 2, wherein the first layer piezoelectric element and the second layer piezoelectric element are separated from each other by a beam and stacked. It is formed.

  An actuator according to a fourth aspect is the actuator according to any one of the first to third aspects, wherein the second layer electrode is grounded and the first layer electrode and the third layer electrode are respectively grounded. An antiphase voltage is applied.

  An actuator according to claim 5 is the actuator according to any one of claims 1 to 4, wherein the first layer electrode connected to one of the pair of beams and the other beam are connected to each other. A voltage having an opposite phase is applied to each of the connected first layer electrodes.

  The actuator according to claim 6 is the actuator according to claim 5, wherein the support portion includes a pair of beams at positions facing each other across the movable portion, and is connected to each pair of beams. A voltage is applied to each of the first layer electrode and the third layer electrode.

  An actuator according to a seventh aspect is the actuator according to the sixth aspect, wherein the first layer electrode connected to one of the two pairs of beams symmetrically about the movable portion and the other of the two pairs of beams A voltage having an opposite phase is applied to each of the first layer electrodes connected to the beam.

  An actuator according to an eighth aspect is the actuator according to any one of the first to seventh aspects, wherein the upper piezoelectric element made of a piezoelectric element layer and a beam are separated and laminated on the third layer electrode. It is characterized in that upper electrodes made of the formed electrode layers are alternately laminated.

  Furthermore, the actuator according to claim 9 is the actuator according to any one of claims 1 to 7, wherein a voltage having an opposite phase is applied to each of the upper electrodes arranged with the upper piezoelectric element interposed therebetween. It is characterized by.

  According to the actuator of claim 1, the first layer piezoelectric element located between the first layer electrode and the second layer electrode is displaced, and the second layer located between the second layer electrode and the third layer electrode. By displacing the piezoelectric element, it is possible to increase the swing displacement amount of the movable part and improve the driving force of the actuator.

  According to the actuator of the second aspect, the piezoelectric element is formed on both surfaces of the support portion that supports the movable portion, and the stress generated on the support portion is reduced by displacing the piezoelectric elements on both surfaces. It is possible to increase the driving force of the actuator further.

  According to the actuator of the third aspect, the swing displacement amount of the movable portion can be increased by forming the piezoelectric element separately for each beam and displacing the piezoelectric element for each beam. .

  According to the actuator of the fourth aspect, by causing the displacement direction of the first layer piezoelectric element and the displacement direction of the second layer piezoelectric element to be the same direction, it is possible to increase the stress generated on the support portion and The swing displacement amount of the part can be further increased.

  Further, according to the actuator of the fifth aspect, since the stress in the opposite direction is applied to each of the pair of beams, the swing displacement amount of the movable portion supported by the support portion can be further increased. .

  Further, according to the actuator of claim 6, since the stress is applied to each beam to be supported with respect to the beam portion supported from the left and right directions around the movable portion, the movable portion supported by the support portion. Can be increased.

  In addition, according to the actuator of the seventh aspect, stress in the opposite direction is applied to each of the beam portions that are symmetrically located at the center of the movable portion, so that the swing displacement amount of the movable portion supported by the support portion Can be increased.

  Further, according to the actuator of the eighth aspect, by further increasing the piezoelectric element layers and electrode layers to be stacked, a large number of piezoelectric elements between the electrodes are displaced, and the swing displacement amount of the movable portion is further increased. It becomes possible. Therefore, it becomes possible to improve the driving force of the actuator.

  Furthermore, according to the actuator of the ninth aspect, by causing the piezoelectric elements to be displaced in the same direction for a large number of stacked piezoelectric elements, the stress generated on the support portion is increased, and the movable portion is swung. The amount of displacement can be increased.

  Hereinafter, the actuator according to the present invention will be described in detail with reference to the drawings based on first to fourth embodiments.

(First embodiment)
[Schematic structure of actuator]
First, a schematic configuration of the actuator 1 according to the first embodiment will be described with reference to FIG. FIG. 1 is an exploded perspective view schematically showing a schematic configuration of the actuator 1.
As shown in FIG. 1, the actuator 1 is configured by mounting a main body 2 on a base 3.

  First, the main body 2 will be described in detail. The main body 2 is formed on a base material 4 formed using an elastic material such as silicon. First electrode layers 5A to 5D, first piezoelectric element layers 6A and 6B, second electrode layers 7A to 7D, which will be described later, The second piezoelectric element layers 8A and 8B and the third electrode layers 9A to 9D are stacked. The first electrode layers 5A to 5D constitute the first layer electrode of the actuator 1, the first piezoelectric element layers 6A and 6B constitute the first layer piezoelectric element of the actuator 1, and the second electrode layers 7A to 7D The second layer electrode of the actuator 1 is constituted, the second piezoelectric element layers 8A and 8B constitute the second layer piezoelectric element of the actuator 1, and the third electrode layers 9A to 9D constitute the third layer electrode of the actuator 1. . Moreover, the thickness after lamination | stacking of the main-body part 2 shall be about 30 micrometers-200 micrometers.

  Further, as shown in the upper part of FIG. 1, the main body 2 has a thin plate rectangular shape having a through hole 11 through which light can pass. The main body 2 includes a reflecting mirror portion 13 having a substantially circular shape in plan view on which the reflecting surface 12 is formed, a pair of beam portions 14A and 14B that swingably support the reflecting mirror portion 13, and the main body portion 2 on the outside. And a fixing frame 16 for fixing the. A portion composed of the reflection mirror portion 13 and the beam portions 14A and 14B is referred to as a vibrating body 15.

  Here, the reflection mirror part 13 is a movable part supported so as to be swingable with respect to the fixed frame 16 by the beam parts 14A and 14B. The reflection mirror 13 grounds the second layer electrode and applies a voltage to the first layer electrode and the third layer electrode as will be described later, thereby swinging around the swing axis 17 that is the symmetrical center line. Moved. The reflection mirror unit 13 is not limited to a circle, but may be a quadrangle, a polygon, or the like.

  The beam portions 14 </ b> A and 14 </ b> B have a flat plate shape, extend from both side surface portions on the swing shaft 17 of the reflection mirror portion 13 to the same surface in the outer direction, and join the reflection mirror portion 13 to the fixed frame 16. Thus, it is a support part that supports the reflection mirror part 13 in a swingable manner. In the actuator 1 of the first embodiment, a pair of beam portions 14A and 14B extend in opposite directions from both side surface portions of the reflection mirror portion 13, respectively.

  One beam portion 14 </ b> A (on the left side in FIG. 1) is in a symmetrical position in a direction perpendicular to the one mirror side leaf spring portion 18 </ b> A disposed on the swing shaft 17 and the swing shaft 17. It is comprised from a pair of frame side leaf | plate spring parts 19A and 19B arrange | positioned, and the connection part 20A which connects these mirror side leaf | plate spring parts 18A and a pair of frame side leaf | plate spring parts 19A and 19B mutually.

  The other beam portion 14B (on the right side in FIG. 1) is in a symmetrical position in a direction perpendicular to the one mirror side leaf spring portion 18B disposed on the swing shaft 17 and the swing shaft 17. It is comprised from a pair of frame side leaf | plate spring parts 19C and 19D arrange | positioned, and the connection part 20B which mutually connects these mirror side leaf | plate spring parts 18B and a pair of frame side leaf | plate spring parts 19C and 19D.

  Therefore, as shown in the upper part of FIG. 1, the pair of frame side leaf spring portions 19A, 19B and the pair of frame side leaf spring portions 19C, 19D sandwich the reflection mirror portion 13 and each frame side leaf spring portion 19A, 19D, Each frame side leaf | plate spring part 19B, 19C is arrange | positioned so that it may each oppose a rocking | fluctuation axis direction. In other words, the pair of frame side leaf springs 19A and 19B and the pair of frame side leaf springs 19C and 19D sandwich the reflection mirror part 13, and each frame side leaf spring 19A and 19C and each frame side leaf spring 19B and 19D. These are arranged so as to face each other diagonally.

  Moreover, in each beam part 14A, 14B, each mirror side leaf | plate spring part 18A, 18B corresponds to each connection part 20A corresponding from one of a pair of edges which mutually oppose on the rocking | fluctuation axis | shaft 17 among the reflective mirror parts 13. It extends to 20B. Further, each of the connecting portions 20 </ b> A and 20 </ b> B extends in a direction orthogonal to the swing shaft 17. Furthermore, in each beam part 14A, 14B, a pair of frame side leaf | plate spring part 19A, 19B and a pair of frame side leaf | plate spring part 19C, 19D are the rocking | fluctuation shaft 17 from the edge part of each corresponding connection part 20A, 20B. It extends to the fixed frame 16 in parallel to.

Further, in the beam portion 14A, a pair of first electrodes laminated in a thickness of 0.2 μm to 0.6 μm as described later from the pair of frame side leaf spring portions 19A and 19B to the fixed frame 16. Layers 5A and 5B are formed. Each pair of first electrode layers 5A and 5B is formed separately for each of the two beams constituting the beam portion 14A with the swing shaft 17 interposed therebetween.
On the other hand, in the beam portion 14B, a pair of first electrodes laminated in a thickness of 0.2 μm to 0.6 μm as described later from the pair of frame side leaf spring portions 19C and 19D to the fixed frame 16. Layers 5C and 5D are formed. Each pair of first electrode layers 5C and 5D is formed separately for each of the two beams constituting the beam portion 14B with the swing shaft 17 interposed therebetween.

  In addition, a predetermined gap is formed on the upper side of the pair of first electrode layers 5A and 5B from the outer peripheral portion of each of the first electrode layers 5A and 5B on the fixed frame 16 side from each of the pair of frame-side leaf spring portions 19A and 19B. Thus, as described later, the first piezoelectric element layer 6A laminated with a thickness of 1 μm to 3 μm is formed. Accordingly, the first piezoelectric element layer 6A is formed so as to extend from the fixed frame 16 onto the frame side leaf spring portions 19A and 19B, and to cover the separation portion between the pair of first electrode layers 5A and 5B. Has been.

  Further, a predetermined gap is formed on the upper side of the pair of first electrode layers 5C and 5D from the outer peripheral portion of the first electrode layers 5C and 5D on the fixed frame 16 side from each of the pair of frame side leaf spring portions 19C and 19D. As described later, the first piezoelectric element layer 6B laminated with a thickness of 1 μm to 3 μm is formed as will be described later. Accordingly, the first piezoelectric element layer 6B is formed to extend from the fixed frame 16 onto the frame side leaf spring portions 19C and 19D, and to cover the separation portion between the pair of first electrode layers 5C and 5D. Has been.

  Further, on the upper side of the first piezoelectric element layer 6A, a predetermined gap is formed from each of the pair of frame side leaf spring parts 19A and 19B with the outer peripheral part on the fixed frame 16 side of the first piezoelectric element layer 6A. Thus, a pair of second electrode layers 7A and 7B laminated with a thickness of 0.2 μm to 0.6 μm are formed. The pair of second electrode layers 7A and 7B are formed separately for each of the two beams constituting the beam portion 14A with the swing shaft 17 interposed therebetween.

  Further, on the upper side of the first piezoelectric element layer 6B, a predetermined gap is formed from each of the pair of frame side leaf spring portions 19C and 19D with the outer peripheral portion on the fixed frame 16 side of the first piezoelectric element layer 6B. Thus, a pair of second electrode layers 7C and 7D are formed which are stacked with a thickness of 0.2 μm to 0.6 μm. In addition, the pair of second electrode layers 7C and 7D are formed separately for each of the two beams constituting the beam portion 14B with the swing shaft 17 interposed therebetween.

  Further, a predetermined gap is formed on the upper side of the pair of second electrode layers 7A and 7B from the outer peripheral portion of the second electrode layers 7A and 7B on the fixed frame 16 side from the pair of frame side leaf spring portions 19A and 19B, respectively. Thus, as described later, the second piezoelectric element layer 8A laminated with a thickness of 1 μm to 3 μm is formed. Accordingly, the second piezoelectric element layer 8A is formed to extend from the fixed frame 16 onto the frame side leaf spring portions 19A and 19B, and to cover the separation portion between each pair of the second electrode layers 7A and 7B. Has been.

In addition, a predetermined gap is formed on the upper side of the pair of second electrode layers 7C and 7D from the outer peripheral portion of the second electrode layers 7C and 7D on the fixed frame 16 side from the pair of frame side leaf spring portions 19C and 19D, respectively. Thus, as described later, the second piezoelectric element layer 8B laminated with a thickness of 1 μm to 3 μm is formed. Accordingly, the second piezoelectric element layer 8B is formed so as to extend from the fixed frame 16 onto the frame side leaf spring portions 19C, 19D, and to cover the separation portion between the pair of second electrode layers 7C, 7D. Has been.
The second piezoelectric element layers 8A and 8B have a larger formation area than the first piezoelectric element layers 6A and 6B. Thereby, the coverage of the electrode is increased.

  Further, on the upper side of the second piezoelectric element layer 8A, a predetermined gap is formed from each of the pair of frame side leaf spring portions 19A, 19B with the outer peripheral portion on the fixed frame 16 side of the second piezoelectric element layer 8A. Thus, a pair of third electrode layers 9A and 9B are formed which are stacked with a thickness of 0.2 μm to 0.6 μm. Further, the pair of third electrode layers 9A and 9B are formed separately for each of the two beams constituting the beam portion 14A with the swing shaft 17 interposed therebetween.

  Further, on the upper side of the second piezoelectric element layer 8B, a predetermined gap is formed from each of the pair of frame side leaf spring portions 19C, 19D with the outer peripheral portion on the fixed frame 16 side of the second piezoelectric element layer 8B. Thus, a pair of third electrode layers 9C and 9D are formed which are stacked with a thickness of 0.2 μm to 0.6 μm. In addition, the pair of second electrode layers 7C and 7D are formed separately for each of the two beams constituting the beam portion 14B with the swing shaft 17 interposed therebetween.

  Accordingly, wire bonding is performed to the portions of the first electrode layers 5A to 5D, the second electrode layers 7A to 7D, and the third electrode layers 9A to 9D formed on the fixed frame 16, and the frame-side leaf spring portions 19A to 19D. It is possible to apply a drive voltage to or to detect the generated voltage. That is, it is possible to apply a driving voltage and detect a generated voltage without applying a load to each of the frame side leaf spring portions 19A to 19D. A specific driving method of the actuator 1 will be described later.

  On the other hand, as shown in the lower part of FIG. 1, the base 3 corresponds to the above-described configuration of the main body 2. 15 and the recessed part 23 which opposes. The recess 23 has a shape that does not interfere with the base 3 even when the vibrating body 15 is displaced by vibration in a state where the main body 2 is mounted on the base 3.

[Actuator manufacturing method]
Next, a method for manufacturing the main body 2 of the actuator 1 will be described with reference to FIGS.
FIG. 2 is an explanatory view showing the production of the fixed frame 16, the reflection mirror portion 13, and the beam portions 14A and 14B. FIG. 3 is an explanatory view showing the production of the first layer electrode. FIG. 4 is an explanatory view showing the production of the first layer piezoelectric element. FIG. 5 is an explanatory view showing the production of the second layer electrode. FIG. 6 is an explanatory view showing the fabrication of the second layer piezoelectric element. FIG. 7 is an explanatory view showing the production of the third layer electrode. FIG. 8 is a schematic diagram showing a cross section taken along arrow X1-X1 in FIG. FIG. 9 is a schematic diagram showing a cross section taken along arrow X2-X2 of FIG.

  First, as shown in FIG. 2, a resist film is formed on a portion of the base 4 made of thin rectangular silicon having a thickness of about 30 μm to 200 μm, excluding the portion of the through holes 11, and masking is performed. Subsequently, after the masking, an etching process is performed to form the through hole 11, and then the resist film is removed. Thereby, each mirror side leaf | plate spring part 18A, 18B, each frame side leaf | plate spring part 19A-19D, and each connection part 20A, 20B which comprise the fixed frame 16, the reflective mirror part 13, and each beam part 14A, 14B are formed.

  Next, as shown in FIG. 3, a resist film is formed and masked at portions other than the portions where the first electrode layers 5 </ b> A to 5 </ b> D on the upper side of the fixed frame 16 and the frame-side leaf spring portions 19 </ b> A to 19 </ b> D are formed. I do. Subsequently, after masking, 0.05 μm of titanium (Ti) is laminated. Next, platinum (Pt), gold (Au), or the like is laminated by 0.2 μm to 0.6 μm to form the first electrode layers 5A to 5D. Thereafter, the resist film is removed. Thereby, as shown in FIGS. 3, 8, and 9, the first electrode layers 5 </ b> A to 5 </ b> D are separated from each frame side leaf spring portion 19 </ b> A to 19 </ b> D to the fixed frame 16 for each beam. It is formed.

  Note that the pair of first electrode layers 5A and 5B and the pair of first electrode layers 5C and 5D may be divided after being formed in a continuous state. Specifically, after the first electrode layers 5A and 5B and the first electrode layers 5C and 5D are formed in a continuous state, separation holes each having a predetermined width are formed along the swing shaft 17 in the first layers. A resist film is formed and masked so as to be formed over the entire width in the direction of the swing axis 17 of the electrode. Then, after etching and dividing into a pair of first electrode layers 5A and 5B and a pair of first electrode layers 5C and 5D, the resist film is removed. Moreover, you may form each 1st electrode layer 5A-5D not by the shadow mask method but by the etching method.

  Subsequently, as shown in FIG. 4, a resist film is formed and masked on a portion excluding the portion where the first piezoelectric element layers 6A and 6B are formed. Thereafter, piezoelectric elements such as PZT are laminated by 1 μm to 3 μm to form the first piezoelectric element layers 6A and 6B above the first electrode layers 5A and 5B and the first electrode layers 5C and 5D. Thereafter, the resist film is removed. Further, not only a masking method using a resist film but also a shadow mask method may be used.

  As a result, as shown in FIGS. 4, 8, and 9, the first piezoelectric element layer 6A is formed by extending from the fixed frame 16 onto the frame-side plate spring portions 19A, 19B, and each pair of first elements It forms so that the isolation | separation part between electrode layer 5A, 5B may be covered. Further, the first piezoelectric element layer 6B is formed to extend from the fixed frame 16 onto the frame side leaf spring portions 19C, 19D, and is formed so as to cover the separation portion between the pair of first electrode layers 5C, 5D. Is done.

  Thereafter, as shown in FIG. 5, the second electrode layers 7 </ b> A to 7 </ b> D are formed on the upper sides of the first piezoelectric element layers 6 </ b> A and 6 </ b> B from the frame-side plate spring portions 19 </ b> A to 19 </ b> D to the fixed frame 16. Then, a resist film is formed and masked on a portion excluding the surface portion on which the second electrode layers 7A to 7D are formed. Subsequently, after masking, 0.05 μm of titanium (Ti) is laminated. Next, platinum (Pt), gold (Au), or the like is laminated by 0.2 μm to 0.6 μm to form the second electrode layers 7A to 7D. Thereafter, the resist film is removed. As a result, as shown in FIGS. 5, 8, and 9, the second electrode layers 7 </ b> A to 7 </ b> D are separated from each frame side leaf spring portion 19 </ b> A to 19 </ b> D to the fixed frame 16 for each beam. It is formed.

  Note that the pair of second electrode layers 7A and 7B and the pair of second electrode layers 7C and 7D are also formed in a continuous state and then divided in the same manner as the first electrode layers 5A to 5D. Also good.

  Subsequently, as shown in FIG. 6, a resist film is formed and masked on portions excluding the portions where the second piezoelectric element layers 8 </ b> A and 8 </ b> B are formed. Thereafter, piezoelectric elements such as PZT are laminated by 1 μm to 3 μm to form the second piezoelectric element layers 8A and 8B above the second electrode layers 7A and 7B and the second electrode layers 7C and 7D. Thereafter, the resist film is removed. Further, not only a masking method using a resist film but also a shadow mask method may be used.

  As a result, as shown in FIGS. 6, 8 and 9, the second piezoelectric element layer 8A is formed to extend from the fixed frame 16 onto the frame side leaf spring portions 19A and 19B. It forms so that the isolation | separation part between electrode layer 7A, 7B may be covered. Further, the second piezoelectric element layer 8B is formed to extend from the fixed frame 16 onto the frame side leaf spring portions 19C, 19D, and is formed so as to cover the separation portion between the pair of second electrode layers 7C, 7D. Is done.

  Thereafter, as shown in FIG. 7, the third electrode layers 9 </ b> A to 9 </ b> D are formed on the upper side of the second piezoelectric element layers 8 </ b> A and 8 </ b> B from the frame-side plate spring portions 19 </ b> A to 19 </ b> D to the fixed frame 16. Then, a resist film is formed and masked on a portion excluding the surface portion on which the third electrode layers 9A to 9D are formed. Subsequently, after masking, 0.05 μm of titanium (Ti) is laminated. Next, platinum (Pt), gold (Au), or the like is laminated by 0.2 μm to 0.6 μm to form the third electrode layers 9A to 9D. Thereafter, the resist film is removed. As a result, as shown in FIGS. 7 to 9, the third electrode layers 9 </ b> A to 9 </ b> D are formed in a state of being separated for each beam from the frame side leaf spring portions 19 </ b> A to 19 </ b> D to the fixed frame 16. .

  Note that the pair of third electrode layers 9A and 9B and the pair of third electrode layers 9C and 9D are also formed in a continuous state and then divided in the same manner as the first electrode layers 5A to 5D. Also good.

  Moreover, in the manufacturing method of the actuator 1 mentioned above, electrode material and piezoelectric element material are deposited alternately, and 1st electrode layer 5A-5D, 1st piezoelectric element layer 6A, 6B, 2nd electrode layer 7A-7D, The second piezoelectric element layers 8A and 8B and the third electrode layers 9A to 9D are sequentially stacked, and the first layer electrode, the first layer piezoelectric element, the second layer electrode, the second layer piezoelectric element, and the third layer electrode are sequentially stacked. The physical vapor deposition method (PVD: Physical Vapor Deposition) to be formed was adopted. In the physical vapor deposition method, for example, an inert gas is introduced into a vacuum while a DC voltage or an AC voltage is applied between the substrate and the target, and the ionized inert gas is collided with the target to be blown off. There is also an AD method in which film formation is performed by sputtering a material to form a film on a substrate or spraying nano-sized fine particles. However, the present invention is not limited to this, and the first electrode layer, the first piezoelectric element layer, the second electrode layer, the second piezoelectric element layer, and the third electrode layer are formed by chemical vapor deposition (CVD). At least one layer may be formed.

[Driving method]
Next, a method for driving the actuator 1 will be described. The actuator 1 is driven by applying a voltage to each electrode laminated on the substrate 4 as described above, and the reflection mirror unit 13 is driven to swing as the piezoelectric element expands and contracts. FIG. 10 is a diagram illustrating a driving method of the actuator 1 according to the first embodiment. Further, the cross-sectional view shown in FIG. 10 is a cross-sectional view of the actuator 1 in the vicinity of X2-X2 in FIG.

Here, in the actuator 1 according to the first example, the voltage is applied to the first electrode layer 5A, the second electrode layer 7A, and the third electrode layer 9A, thereby being formed on the frame-side leaf spring portions 19A and 19B. The first piezoelectric element layer 6 </ b> A and the second piezoelectric element layer 8 </ b> A function as drive sources, torsionally vibrate the vibrating body 15 about the swing shaft 17, and swing the reflection mirror unit 13 about the swing shaft 17. Let
A voltage may be applied to the first electrode layer 5B, the second electrode layer 7B, and the third electrode layer 9B. Further, a voltage is applied to the first electrode layer 5C, the second electrode layer 7C, the third electrode layer 9C, the first electrode layer 5D, the second electrode layer 7D, and the third electrode layer 9D, so that the frame side leaf spring portion 19C, The first piezoelectric element layer 6B and the second piezoelectric element layer 8B formed on 19D may function as a drive source.

Hereinafter, a method for applying a voltage to each electrode will be described in more detail. Specifically, a predetermined drive voltage (for example, about 1V to 40V) is applied to the first electrode layer 5A and the third electrode layer 9A formed on the frame side leaf spring portion 19A via a drive circuit (not shown). )) Is applied. On the other hand, the second electrode layer 7A is grounded. Note that an alternating voltage having an opposite phase with a phase shifted by 180 ° is applied to the first electrode layer 5A and the third electrode layer 9A.
Further, the amplitudes of the alternating voltages applied to the first electrode layer 5A and the third electrode layer 9A may be the same or different.

  As a result, the first piezoelectric element layer 6A and the second piezoelectric element layer 8A formed on the frame side leaf spring portion 19A are displaced in the direction orthogonal to the direction of application, that is, in the length direction (see FIG. 17). In addition, since opposite phase voltages are applied to the first electrode layer 5A and the third electrode layer 9A, the directions of displacement generated in the first piezoelectric element layer 6A and the second piezoelectric element layer 8A always coincide.

  Then, due to the displacement in the same direction generated in the first piezoelectric element layer 6A and the second piezoelectric element layer 8A, each frame side leaf spring portion 19A has the fixed frame 16 side as a fixed end and the reflection mirror portion 13 side as a free end. Depending on whether each displacement is upward or downward, each free end is displaced upward or downward. As a result, the reflection mirror unit 13 is swung around the swing shaft 17.

  As described above, in the actuator 1 according to the first embodiment, the first electrode layers 5A to 5D, the first piezoelectric element layers 6A and 6B, the second electrode layers 7A to 7D, and the second electrode The piezoelectric element layers 8A and 8B and the third electrode layers 9A to 9D are sequentially stacked, and when the actuator 1 is driven, the second electrode layer 7A is grounded, and the first electrode layer 5A and the third electrode layer 9A are connected to each other. Since the reverse phase alternating voltage is applied, the first layer piezoelectric element between the first layer electrode and the second layer electrode and the second layer piezoelectric element between the second layer electrode and the third layer electrode are in the same direction. By displacing them, the swing displacement amount of the movable part can be increased, and the driving force of the actuator can be improved.

(Second embodiment)
Next, an actuator 51 according to a second embodiment will be described with reference to FIG. In the following description, the same reference numerals as those of the actuator 1 according to the first embodiment shown in FIGS. 1 to 10 denote the same or corresponding parts as those of the actuator 1 according to the first embodiment. .

  The schematic configuration of the actuator 51 according to the second embodiment is substantially the same as that of the actuator 1 according to the first embodiment. However, the actuator 51 according to the second embodiment is similar to the actuator 1 according to the first embodiment in that a third piezoelectric element layer and a fourth electrode layer are sequentially stacked on the third electrode layers 9A to 9D. Is different.

[Schematic structure of actuator]
The actuator 51 according to the second embodiment is configured by further stacking a third piezoelectric element layer 52A and fourth electrode layers 53A, 53B on the actuator 1 shown in the first embodiment. Here, the cross-sectional view shown in FIG. 11 is a drawing corresponding to the cross-section taken along the arrow line X2-X2 of FIG. 7 in the actuator 51 of the second embodiment. Although illustration is omitted, the third piezoelectric element layer and the fourth electrode layer are similarly laminated on the third electrode layers 9C and 9D.

[Schematic structure and driving method of actuator]
Next, a method for driving the actuator 51 of the second embodiment will be described. The actuator 51 is driven by applying a voltage to each electrode laminated on the base material 4 as in the first embodiment, and the reflection mirror 13 is driven to swing as the piezoelectric element expands and contracts. Is done. FIG. 11 shows a driving method of the actuator 51 according to the second embodiment.

Here, in the actuator 51 according to the second embodiment, by applying a voltage to the first electrode layer 5A, the second electrode layer 7A, the third electrode layer 9A, and the fourth electrode layer 53A, the frame side leaf spring portion 19A, The first piezoelectric element layer 6A, the second piezoelectric element layer 8A, and the third piezoelectric element layer 52A formed on 19B function as a drive source, and torsionally vibrate the vibrating body 15 around the swing shaft 17, thereby reflecting The mirror unit 13 is swung around the swing shaft 17.
A voltage may be applied to the first electrode layer 5B, the second electrode layer 7B, the third electrode layer 9B, and the fourth electrode layer 53B.

Hereinafter, a method for applying a voltage to each electrode will be described in more detail. Specifically, a predetermined drive voltage (for example, about approximately) is applied to the first electrode layer 5A, the third electrode layer 9A, and the fourth electrode layer 53A formed on the frame side leaf spring portion 19A via a drive circuit (not shown). An alternating voltage of 1 to 40 V) is applied. On the other hand, the second electrode layer 7A is grounded. Note that an alternating voltage having an opposite phase with a phase shifted by 180 ° is applied to the first electrode layer 5A and the third electrode layer 9A. In addition, an alternating voltage having a phase shifted by 180 ° (that is, an alternating voltage having the same phase is applied to the first electrode layer 5A and the fourth electrode layer 53A) is applied to the third electrode layer 9A and the fourth electrode layer 53A. Is done.
Further, the amplitudes of the alternating voltages applied to the first electrode layer 5A, the third electrode layer 9A, and the fourth electrode layer 53A may all be the same, or may be different from each other at one place or all places. . As shown in FIG. 11, when the amplitude of the alternating voltage applied to the third electrode layer 9A is ΔV ′, the voltage applied to the fourth electrode layer 53A is considered as a pseudo GND of the third electrode layer 9A. As a result, an offset voltage (V + ΔV ′) corresponding to the voltage applied to the third electrode layer 9A becomes an alternating voltage having an amplitude ΔV ″.

When the alternating voltage shown in FIG. 11 is applied to each electrode layer, the electric field state in the third piezoelectric element layer 52A is displaced as shown in FIG. Here, since ΔV, ΔV ′, and ΔV ″ are alternating currents, they change from 0 to ΔV, 0 to ΔV ′, and 0 to ΔV ″, respectively, with respect to time.
Therefore, as shown in (1) of FIG. 12, when ΔV ′ = 0, the electric field applied to the third piezoelectric element layer 52A is zero.
Further, as shown in (2) of FIG. 12, in the case of 0 to ΔV ′, the electric field applied to the third piezoelectric element layer 52A is a negative electric field.
In addition, as shown in (3) of FIG. 12, in the case of ΔV ′, the electric field applied to the third piezoelectric element layer 52A is a negative electric field and has a maximum value.
Also, as shown in FIG. 12 (4), in the case of ΔV′˜0, the electric field applied to the third piezoelectric element layer 52A is a positive electric field.
The electric field state in the third piezoelectric element layer 52A repeatedly changes in the order of (1) → (2) → (3) → (4) → (1) →.

  Thereby, the first piezoelectric element layer 6A, the second piezoelectric element layer 8A, and the third piezoelectric element layer 52A formed on the frame side leaf spring portion 19A are oriented in the direction orthogonal to the application direction, that is, in the length direction. A displacement is generated (see FIG. 17). In addition, a reverse phase voltage is applied to the first electrode layer 5A and the third electrode layer 9A, and a reverse phase voltage is applied to the third electrode layer 9A and the fourth electrode layer 53A. The directions of displacement generated in the first piezoelectric element layer 6A, the second piezoelectric element layer 8A, and the third piezoelectric element layer 52A always coincide with each other.

  Then, due to the displacement in the same direction generated in the first piezoelectric element layer 6A, the second piezoelectric element layer 8A, and the third piezoelectric element layer 52A, each frame side leaf spring portion 19A has the fixed frame 16 side as a fixed end, and a reflection mirror. With the portion 13 side as a free end, each free end is displaced upward or downward depending on whether each displacement is upward or downward. As a result, the reflection mirror unit 13 is swung around the swing shaft 17.

(Third embodiment)
Next, an actuator 101 according to a third embodiment will be described with reference to FIG. In the following description, the same reference numerals as those of the actuator 1 according to the first embodiment shown in FIGS. 1 to 10 denote the same or corresponding parts as those of the actuator 1 according to the first embodiment. .

  The schematic configuration of the actuator 101 according to the third embodiment is substantially the same as that of the actuator 1 according to the first embodiment. However, in the actuator 101 according to the third embodiment, a third piezoelectric element layer, a fourth electrode layer, a fourth piezoelectric element layer, and a fifth electrode layer are sequentially stacked on the third electrode layers 9A to 9D. The actuator 1 is different from the actuator 1 according to the first embodiment.

[Schematic structure of actuator]
The actuator 101 according to the third embodiment is configured by further laminating a fourth piezoelectric element layer 102A and fifth electrode layers 103A and 103B to the actuator 51 shown in the second embodiment. Here, the cross-sectional view shown in FIG. 13 is a drawing corresponding to the cross-section taken along the line X2-X2 in FIG. 7 in the actuator 101 of the third embodiment. Although not shown, the fourth piezoelectric element layer and the fifth electrode layer are similarly laminated on the third electrode layers 9C and 9D.

[Schematic structure and driving method of actuator]
Next, a method for driving the actuator 101 according to the third embodiment will be described. The actuator 101 is driven by applying a voltage to each electrode stacked on the substrate 4 as in the first embodiment, and the reflection mirror 13 is driven to swing as the piezoelectric element expands and contracts. Is done. FIG. 13 shows a driving method of the actuator 101 according to the third embodiment.

Here, in the actuator 101 according to the third example, by applying a voltage to the first electrode layer 5A, the second electrode layer 7A, the third electrode layer 9A, the fourth electrode layer 53A, and the fifth electrode layer 103A, The first piezoelectric element layer 6A, the second piezoelectric element layer 8A, the third piezoelectric element layer 52A, and the fourth piezoelectric element layer 102A formed on the frame side leaf spring portions 19A and 19B function as a drive source, and the vibrating body 15 is The reflection mirror unit 13 is swung around the swinging shaft 17 by torsionally vibrating around the swinging shaft 17.
A voltage may be applied to the first electrode layer 5B, the second electrode layer 7B, the third electrode layer 9B, the fourth electrode layer 53B, and the fifth electrode layer 103B.

Hereinafter, a method for applying a voltage to each electrode will be described in more detail. Specifically, the first electrode layer 5A, the third electrode layer 9A, the fourth electrode layer 53A, and the fifth electrode layer 103A formed on the frame-side leaf spring portion 19A are predetermined via a drive circuit (not shown). An alternating voltage of a drive voltage (for example, about 1 V to 40 V) is applied. On the other hand, the second electrode layer 7A is grounded. Note that an alternating voltage having an opposite phase with a phase shifted by 180 ° is applied to the first electrode layer 5A and the third electrode layer 9A. In addition, an alternating voltage having a phase shifted by 180 ° (that is, an alternating voltage having the same phase is applied to the first electrode layer 5A and the fourth electrode layer 53A) is applied to the third electrode layer 9A and the fourth electrode layer 53A. Is done. The fourth electrode layer 53A and the fifth electrode layer 103A are applied with alternating voltages having opposite phases with a phase shift of 180 ° (that is, the third electrode layer 9A and the fifth electrode layer 103A have the same phase alternating voltage). Is done.
In addition, the amplitudes of the alternating voltages applied to the first electrode layer 5A, the third electrode layer 9A, the fourth electrode layer 53A, and the fifth electrode layer 103A may all be the same, or may be a plurality of locations or all locations. It may be a different size. As shown in FIG. 13, when the amplitude of the alternating voltage applied to the third electrode layer 9A is ΔV ′, the voltage applied to the fourth electrode layer 53A is considered as a pseudo GND of the third electrode layer 9A. As a result, an offset voltage (V + ΔV ′) corresponding to the voltage applied to the third electrode layer 9A becomes an alternating voltage having an amplitude ΔV ″. In addition, the voltage applied to the fifth electrode layer 103A is an offset voltage (V + ΔV ′ + ΔV ″) corresponding to the voltage applied to the fourth electrode layer 53A by simulating the fourth electrode layer 53A as GND. Becomes an alternating voltage having an amplitude ΔV ′ ″.

  Accordingly, the first piezoelectric element layer 6A, the second piezoelectric element layer 8A, the third piezoelectric element layer 52A, and the fourth piezoelectric element layer 102A formed on the frame side leaf spring portion 19A have directions orthogonal to the application direction. That is, a displacement in the length direction is generated (see FIG. 17). In addition, an antiphase voltage is applied to the first electrode layer 5A and the third electrode layer 9A, an antiphase voltage is applied to the third electrode layer 9A and the fourth electrode layer 53A, and the fourth electrode layer 53A is applied. And the fifth electrode layer 103A are applied with voltages having opposite phases, so that the displacement generated in the first piezoelectric element layer 6A, the second piezoelectric element layer 8A, the third piezoelectric element layer 52A, and the fourth piezoelectric element layer 102A. The directions always match.

  Each frame-side leaf spring portion 19A is moved to the fixed frame 16 side by the displacement in the same direction generated in the first piezoelectric element layer 6A, the second piezoelectric element layer 8A, the third piezoelectric element layer 52A, and the fourth piezoelectric element layer 102A. The free end is displaced upward or downward depending on whether each displacement is upward or downward, with the fixed end as the fixed end and the reflecting mirror portion 13 side as the free end. As a result, the reflection mirror unit 13 is swung around the swing shaft 17.

As described above, in the actuator 101 according to the second and third embodiments, as compared with the first embodiment, the piezoelectric element layers and electrode layers to be stacked are further increased, so that a large number of piezoelectric elements between the electrodes can be obtained. It is possible to displace the element layer and increase the amount of oscillation displacement of the reflection mirror unit 13. Therefore, it becomes possible to improve the driving force of the actuator.
In addition, the third electrode layer 9A and the fourth electrode layer 53A disposed with the third piezoelectric element layer 52A interposed therebetween are applied with voltages having opposite phases, and the fourth electrode disposed with the fourth piezoelectric element layer 102A interposed therebetween. Since voltages having opposite phases are applied to the layer 53A and the fifth electrode layer 103A, the displacement directions of the piezoelectric element layers can be made the same for a large number of stacked piezoelectric element layers. Accordingly, the stress generated on the beam can be increased, and the amount of swing displacement of the reflection mirror portion 13 can be increased.

(Fourth embodiment)
Next, an actuator 151 according to a fourth embodiment will be described with reference to FIG. In the following description, the same reference numerals as those of the actuator 1 according to the first embodiment shown in FIGS. 1 to 10 denote the same or corresponding parts as those of the actuator 1 according to the first embodiment. .

  The schematic configuration of the actuator 151 according to the fourth embodiment is substantially the same as that of the actuator 1 according to the first embodiment. However, in the actuator 151 according to the fourth embodiment, the piezoelectric element layer is also formed separately for each of the two beams constituting the beam portions 14A and 14B in the same manner as the electrode layer, and each separated piezoelectric element layer is formed. Is different in that an electric field is applied in different directions.

[Schematic structure of actuator]
The actuator 151 according to the fourth example is configured by dividing the first piezoelectric element layer 6A in the actuator 1 shown in the first example into a first right piezoelectric element layer 152A and a first left piezoelectric element layer 152B, The second piezoelectric element layer 8A is divided into a second right piezoelectric element layer 153A and a second left piezoelectric element layer 153B. Here, the cross-sectional view shown in FIG. 14 is a drawing corresponding to an arrow cross-section in the vicinity of X2-X2 of FIG. 7 in the actuator 151 of the fourth embodiment. Although not shown, the first piezoelectric element layer 6B and the second piezoelectric element layer 8B are similarly divided for each beam.

[Schematic structure and driving method of actuator]
Next, a method for driving the actuator 151 of the fourth embodiment will be described. The actuator 151 is driven by applying a voltage to each electrode laminated on the substrate 4 as in the first embodiment, and the reflecting mirror 13 is driven to swing as the piezoelectric element expands and contracts. Is done. FIG. 14 shows a driving method of the actuator 151 according to the fourth embodiment.

  Here, in the actuator 151 according to the fourth example, a voltage is applied to the first electrode layer 5A, the second electrode layer 7A, and the third electrode layer 9A, and at the same time, the first electrode layer 5B, the second electrode layer 7B, By applying a voltage also to the three-electrode layer 9B, the first right piezoelectric element layer 152A, the first left piezoelectric element layer 152B, the second right piezoelectric element layer 153A and the first right piezoelectric element layer 153A formed on the frame side leaf springs 19A and 19B 2 The left piezoelectric element layer 153B functions as a drive source, torsionally vibrates the vibrating body 15 around the swing shaft 17, and swings the reflection mirror portion 13 around the swing shaft 17.

Hereinafter, a method for applying a voltage to each electrode will be described in more detail. Specifically, a predetermined drive voltage (for example, about 1 V to 40 V) is applied to the first electrode layer 5A and the third electrode layer 9A formed on the frame side leaf spring portion 19A via a drive circuit (not shown). ) Is applied. On the other hand, the second electrode layer 7A is grounded. Note that an alternating voltage having an opposite phase with a phase shifted by 180 ° is applied to the first electrode layer 5A and the third electrode layer 9A.
Further, an alternating voltage of a predetermined drive voltage (for example, about 1 V to 40 V) is applied to the first electrode layer 5B and the third electrode layer 9B formed on the frame side leaf spring portion 19B via a drive circuit. . On the other hand, the second electrode layer 7B is grounded. Note that an alternating voltage having an opposite phase with a phase shifted by 180 ° is applied to the first electrode layer 5B and the third electrode layer 9B. In addition, an alternating voltage having a phase shifted by 180 ° (that is, an alternating voltage having an opposite phase also applied to the third electrode layer 9A and the third electrode layer 9B) is applied to the first electrode layer 5A and the first electrode layer 5B. Is done.
Further, the amplitudes of the alternating voltages applied to the first electrode layer 5A, the first electrode layer 5B, the third electrode layer 9A, and the third electrode layer 9B may all be the same, or may be a plurality of locations or all locations. It may be a different size.

As a result, the first right piezoelectric element layer 152A and the second right piezoelectric element layer 153A formed on the frame side leaf spring portion 19A are displaced in the direction orthogonal to the application direction, that is, in the length direction. (See FIG. 17). In addition, since opposite phase voltages are applied to the first electrode layer 5A and the third electrode layer 9A, the directions of the displacements generated in the first right piezoelectric element layer 152A and the second right piezoelectric element layer 153A are always the same. To do.
On the other hand, the first left piezoelectric element layer 152B and the second left piezoelectric element layer 153B formed on the frame side leaf spring portion 19B are also displaced in the direction perpendicular to the direction of application, that is, in the length direction. . However, since voltages having opposite phases are applied to the first electrode layer 5A and the first electrode layer 5B, the first right piezoelectric element layer 152A, the second right piezoelectric element layer 153A, and the first left piezoelectric element layer 152B are applied. And the direction of the displacement generated in the second left piezoelectric element layer 153B is always the opposite direction.

  The frame-side leaf spring portion 19A and the frame are then moved by displacements in opposite directions generated in the first right-side piezoelectric element layer 152A, the second right-side piezoelectric element layer 153A, the first left-side piezoelectric element layer 152B, and the second left-side piezoelectric element layer 153B. The side leaf spring portions 19B are alternately displaced upward or downward. As a result, the reflection mirror unit 13 is swung more largely around the swing shaft 17.

  In the fourth embodiment, the reflection mirror unit 13 is increased in swinging by applying an alternating voltage having an opposite phase to the electrodes of adjacent beams (pattern 1 in FIG. 15). The object can also be achieved by other driving methods shown in Patterns 2 to 4.

For example, as shown in the pattern 2, by applying an alternating voltage having the same phase to the electrodes of the beam A and the beam D that are symmetrically positioned at the center of the reflection mirror unit 13, stresses in the same direction are applied to the beam A and the beam D, respectively. Therefore, the amount of rocking displacement of the reflecting mirror unit 13 can be increased.
Further, as shown in the pattern 3, by applying an alternating voltage having an opposite phase to the electrodes of the beam A and the beam C diagonally located at the center of the reflection mirror portion 13, the beam A and the beam C are respectively reversed in directions. Therefore, the amount of oscillation displacement of the reflecting mirror unit 13 can be increased.
Further, as shown in the pattern 4, an alternating voltage having an opposite phase is applied to the electrodes of the adjacent beams A and B, and the alternating electrodes having the same phase are applied to the electrodes of the beams A and D that are symmetrically positioned at the center of the reflection mirror portion 13. Stress is applied to beam A and beam B in the same direction by applying a voltage and applying an alternating voltage of opposite phase to the electrodes of beam A and beam C located diagonally at the center of the reflecting mirror 13. At the same time, stresses in the opposite directions can be applied to the beams C and D, respectively. Therefore, the amount of oscillation displacement of the reflecting mirror unit 13 can be further increased.

As described above, in the actuator 151 according to the fourth embodiment, compared to the first embodiment, the piezoelectric element layer is divided for each beam, and the first electrode layer and the third electrode layer of the adjacent beams are respectively reversed. By applying the alternating voltage of the phase, stress in the opposite direction can be applied to each of the pair of beams, so that the swing displacement amount of the reflection mirror unit 13 can be further increased.
(5th Example)
Next, an actuator 201 according to a fifth embodiment will be described with reference to FIG. In the following description, the same reference numerals as those of the actuator 1 according to the first embodiment shown in FIGS. 1 to 10 denote the same or corresponding parts as those of the actuator 1 according to the first embodiment. .

  The schematic configuration of the actuator 201 according to the fifth embodiment is substantially the same as that of the actuator 1 according to the first embodiment. However, the actuator 201 according to the fifth embodiment is different from the actuator 1 according to the first embodiment in that an electrode layer and a piezoelectric element layer are sequentially laminated on both surfaces of the substrate 4.

[Schematic structure of actuator]
The actuator 201 according to the fifth embodiment has the first electrode layers 202A and 202B, the first piezoelectric element layer 203A, and the actuator 1 shown in the first embodiment, further on the back side surface of the substrate 4. The second electrode layers 204A and 204B, the second piezoelectric element layer 205A, and the third electrode layers 206A and 206B are laminated. Here, the cross-sectional view shown in FIG. 16 is a drawing corresponding to the cross-section taken along the arrow line X2-X2 in FIG. 7 in the actuator 201 of the fifth embodiment. Although not shown, the first electrode layer, the first piezoelectric element layer, the second electrode layer, the second piezoelectric element layer, and the third electrode layer are also provided on the back side surface of the base 4 on the frame side leaf spring portions 19C and 19D. Are stacked in the same manner.

[Schematic structure and driving method of actuator]
Next, a method for driving the actuator 201 of the fifth embodiment will be described. The actuator 201 is driven by applying a voltage to each electrode stacked on the substrate 4 as in the first embodiment, and the reflecting mirror 13 is driven to swing as the piezoelectric element expands and contracts. Is done. FIG. 16 shows a driving method of the actuator 201 according to the fifth embodiment.

Here, in the actuator 201 according to the fifth example, a voltage is applied to the first electrode layer 5A, the second electrode layer 7A, and the third electrode layer 9A, and at the same time, the first electrode layer 202A, the second electrode layer 204A, By applying a voltage also to the three-electrode layer 206A, the first piezoelectric element layers 6A and 203A and the second piezoelectric element layers 8A and 205A formed on the frame side leaf spring portion 19A function as a drive source, and the vibrating body 15 Is torsionally oscillated around the oscillating shaft 17 to oscillate the reflecting mirror portion 13 about the oscillating shaft 17.
A voltage may be applied to the first electrode layer 5B, the second electrode layer 7B, the third electrode layer 9B, the first electrode layer 202B, the second electrode layer 204B, and the third electrode layer 206B.

Hereinafter, a method for applying a voltage to each electrode will be described in more detail. Specifically, a predetermined drive voltage (for example, about 1V to 40V) is applied to the first electrode layer 5A and the third electrode layer 9A formed on the surface side of the frame side leaf spring portion 19A via a drive circuit (not shown). The alternating voltage is applied. On the other hand, the second electrode layer 7A is grounded. Note that an alternating voltage having an opposite phase with a phase shifted by 180 ° is applied to the first electrode layer 5A and the third electrode layer 9A.
Further, an alternating voltage of a predetermined drive voltage (for example, about 1 V to 40 V) is applied to the first electrode layer 202A and the third electrode layer 206A formed on the back side of the frame side leaf spring portion 19A via a drive circuit. Applied. On the other hand, the second electrode layer 204A is grounded. Note that an alternating voltage having an opposite phase with a phase shifted by 180 ° is applied to the first electrode layer 202A and the third electrode layer 206A. Further, an alternating voltage having an opposite phase with a phase shift of 180 ° (that is, an alternating voltage having an opposite phase also to the third electrode layer 9A and the third electrode layer 206A) is applied to the first electrode layer 5A and the first electrode layer 202A. Is done.
In addition, the amplitudes of the alternating voltages applied to the first electrode layer 5A, the first electrode layer 202A, the third electrode layer 9A, and the third electrode layer 206A may all be the same, or may be a plurality of locations or all locations. It may be a different size.

As a result, the first piezoelectric element layer 6A and the second piezoelectric element layer 8A formed on the surface side of the frame side leaf spring portion 19A are displaced in the direction perpendicular to the direction of application, that is, in the length direction. (See FIG. 17). In addition, since opposite phase voltages are applied to the first electrode layer 5A and the third electrode layer 9A, the directions of displacement generated in the first piezoelectric element layer 6A and the second piezoelectric element layer 8A always coincide.
On the other hand, the first piezoelectric element layer 203A and the second piezoelectric element layer 205A formed on the back side of the frame side leaf spring portion 19A are also displaced in the direction perpendicular to the direction of application, that is, in the length direction. The In addition, since voltages having opposite phases are applied to the first electrode layer 5A and the first electrode layer 202A, the direction of displacement generated in the first piezoelectric element layer 203A and the second piezoelectric element layer 205A is the first piezoelectric layer. It always coincides with the direction of displacement generated in the element layer 6A and the second piezoelectric element layer 8A.

  Each frame-side leaf spring portion 19A is moved to the fixed frame 16 side by the displacement in the same direction generated in the first piezoelectric element layer 6A and the second piezoelectric element layer 8A and the first piezoelectric element layer 203A and the second piezoelectric element layer 205A. The free end is displaced upward or downward depending on whether each displacement is upward or downward, with the fixed end as the fixed end and the reflecting mirror portion 13 side as the free end. As a result, the reflection mirror unit 13 is swung around the swing shaft 17.

  As described above, in the actuator 201 according to the fifth embodiment, compared to the first embodiment, the piezoelectric element layer and the electrode layer are formed on both surfaces of the beam supporting the reflection mirror unit 13, and both surfaces of the piezoelectric device are piezoelectric. By displacing each element layer, the stress generated on the beam can be increased, and the driving force of the actuator can be further improved.

It is a disassembled perspective view which shows typically schematic structure of the actuator which concerns on 1st Example. It is explanatory drawing which shows preparation of a fixed frame, a reflective mirror part, and each beam part. It is explanatory drawing which shows preparation of a 1st layer electrode. It is explanatory drawing which shows preparation of a 1st layer piezoelectric element. It is explanatory drawing which shows preparation of a 2nd layer electrode. It is explanatory drawing which shows preparation of a 2nd layer piezoelectric element. It is explanatory drawing which shows preparation of a 3rd layer electrode. It is a schematic diagram which shows the X1-X1 arrow cross section of FIG. It is a schematic diagram which shows the X2-X2 arrow cross section of FIG. It is the figure which showed the drive method of the actuator which concerns on 1st Example. It is the figure which showed schematic structure and the drive method of the actuator which concerns on 2nd Example. It is the figure which showed the electric field state in the 3rd piezoelectric element layer of the actuator which concerns on 2nd Example. It is the figure which showed schematic structure and the drive method of the actuator which concerns on 3rd Example. It is the figure which showed schematic structure and the drive method of the actuator which concerns on 4th Example. It is the figure which showed the other drive method of the actuator which concerns on 4th Example. It is the figure which showed schematic structure and the drive method of the actuator which concerns on 5th Example. It is explanatory drawing which showed the drive mechanism used as the basis of an actuator.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1, 51, 101, 151,201 Actuator 4 Base material 5A-5D, 202A, 202B 1st electrode layer 6A, 6B, 203A 1st piezoelectric element layer 7A-7D, 204A, 204B 2nd electrode layer 8A, 8B, 205A Second piezoelectric element layer 9A to 9D, 206A, 206B Third electrode layer 13 Reflection mirror part 14A, 14B Beam part 52A Third piezoelectric element layer 53A, 53B Fourth electrode layer 102A Fourth piezoelectric element layer 103A, 103B Fifth electrode Layer 152A First right piezoelectric element layer 152B First left piezoelectric element layer 153A Second right piezoelectric element layer 153B Second left piezoelectric element layer

Claims (9)

An actuator that has a support part including at least two pairs of beams, and a movable part that is swingably supported via the support part, and that swings the movable part by applying a voltage;
A first layer electrode formed of an electrode layer laminated separately on each beam on the support;
A first layer piezoelectric element formed from a piezoelectric element layer laminated on the first layer electrode;
A second layer electrode formed from an electrode layer laminated separately for each beam on the first layer piezoelectric element;
A second layer piezoelectric element formed from a piezoelectric element layer laminated on the second layer electrode;
An actuator comprising: a third layer electrode formed from an electrode layer laminated separately on each beam on the second layer piezoelectric element. The support portion has a flat plate shape,
The said 1st layer electrode, the said 1st layer piezoelectric element, the said 2nd layer electrode, the said 2nd layer piezoelectric element, and the said 3rd layer electrode are formed in both surfaces of the said support part. Actuator.   3. The actuator according to claim 1, wherein the first layer piezoelectric element and the second layer piezoelectric element are formed of piezoelectric element layers that are stacked separately for each beam. 4.   The actuator according to any one of claims 1 to 3, wherein the second layer electrode is grounded, and voltages having opposite phases are applied to the first layer electrode and the third layer electrode, respectively. .   2. A voltage having an opposite phase is applied to the first layer electrode connected to one of the pair of beams and the first layer electrode connected to the other beam, respectively. The actuator according to claim 4. The support part includes a pair of beams at positions facing each other across the movable part,
The actuator according to claim 5, wherein a voltage is applied to each of the first layer electrode and the third layer electrode connected to each pair of beams.   Among the two pairs of beams, voltages having opposite phases are applied to the first layer electrode connected to one beam positioned symmetrically with respect to the movable portion and the first layer electrode connected to the other beam, respectively. The actuator according to claim 6.   8. The upper piezoelectric element made of a piezoelectric element layer and the upper electrode made of an electrode layer laminated separately for each beam are alternately laminated on the third layer electrode. The actuator according to any one of the above.   The actuator according to claim 8, wherein a voltage having an opposite phase is applied to each of the upper electrodes arranged with the upper piezoelectric element interposed therebetween.

Images