JP2008096932A - Lens actuator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lens actuator which can satisfy all required performance requirements such that the size and thickness can be reduced, while sufficiently securing the moving distance of a lens, the power consumption is reduced, the service life is long, a sufficient generation force can be secured and the like. <P>SOLUTION: A piezoelectric element 1 is used as a drive source and a displacement in a uniaxial direction output from the piezoelectric element 1 is transmitted to the lens, while successively enlarging a displacement amount, by a displacement enlarging mechanism 2 provided with a plurality of levers 20 arranged along the transmission direction of the displacement. Since the drive source is the piezoelectric element, there are advantages such that the power consumption is reduced, the service life is long, the sufficient generation force and high responsiveness can be obtained and the like. Since the displacement enlarging mechanism with a specific structure is used, the large moving amount of the lens can be secured regardless of a compact and thin structure. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a lens actuator for a camera module incorporated in a portable terminal or the like.

  A camera module incorporated in a portable terminal such as a cellular phone is required to have a high-speed and high-precision autofocus function and zoom function, as in a normal electronic camera (digital camera). In order to realize these functions, it is necessary to move the lens group of the camera module in the optical axis direction at high speed and with high accuracy, and a mechanism and driving means are required for that purpose.・ Thinning is progressing, so the camera module and its components are also required to be smaller and thinner.

  As an actuator for moving a lens of a camera module, an actuator having a screw-type rotation mechanism is generally known. However, this type of mechanism involves mechanical sliding and has a large energy loss. There is a drawback that wear powder tends to be generated. In addition, there are structural limitations that make it difficult to reduce the size and thickness. For this reason, it cannot be applied to a recent lens moving mechanism for portable terminals that requires power saving, high precision, miniaturization, and thinning.

Also, for example, in Patent Document 1, a movable part holding a lens is supported in a cantilevered manner so as to be movable up and down via an elastic member such as a leaf spring with respect to the fixed part, and between the movable part and the fixed part. 2 shows an actuator provided with a shape memory alloy so that the elastic member can be deformed.
In Patent Document 2, a lens holder is provided so as to be movable along a guide shaft and a drive shaft arranged in parallel to the lens optical axis, and a piezoelectric element mounted on the lens holder is excited so that the drive shaft An actuator is shown that moves a lens holder along a guide shaft and a drive shaft by applying a driving force (a traveling wave due to bending vibration).

JP 2002-130114 A JP 2006-106797 A

  However, the actuators disclosed in Patent Documents 1 and 2 both have a device thickness (actuator height) in the lens moving direction to ensure a sufficient lens moving distance due to structural limitations. There is a problem that it cannot sufficiently cope with the miniaturization and thinning required for the lens movement mechanism for terminals.

On the other hand, a stepping motor, a voice coil motor, a piezoelectric ultrasonic motor, and the like have been conventionally used as a driving source for the focusing mechanism of the camera module.
The stepping motor system is a system that decelerates the rotational output of a small stepping motor by a gear mechanism and converts rotational motion into motion on one axis. This method is characterized by easy position control because the stepping motor has a function of rotating by a certain angle for each voltage pulse applied, but a complicated gear mechanism is indispensable, When the motor is downsized, it is inevitable that the torque is reduced and the power consumption is increased at the same time. Therefore, there is a difficulty in miniaturization and low power consumption.

  The voice coil motor system is a system that uses a magnetic action of a current that a coil receives a force by flowing a current through an air-core coil placed in a magnetic field. This method is capable of high-speed response and is suitable for downsizing, but current must be kept flowing when holding a certain position, and thus it is difficult to realize low power consumption. In addition, this method also has a problem that the generated force is weak because of the structure using attraction and repulsion by a small magnetic circuit.

  The piezoelectric ultrasonic motor system generates two circular vibration modes simultaneously in the piezoelectric element, and generates a circular motion by giving the required phase relationship between the two vibration modes, and uses this circular motion to move the position. It is a method to make it. In addition to this method, there is a method called a smooth impact mechanism. This smooth impact mechanism selects the inertial force generated by alternately applying a fast rising voltage and a slow falling voltage to the piezoelectric element, exceeding the frictional force at the rising point and exceeding the frictional force at the falling point. It is a mechanism that moves in one direction by avoiding it. The piezoelectric ultrasonic motor method and the method using the smooth impact mechanism are common in that the small displacement generated by the piezoelectric element is repeatedly used. Since these methods are friction-held, they do not consume power to maintain a certain position. However, although the power applied to the piezoelectric element is small for each operation, Since the moving distance due to the voltage application is as small as several tens of nanometers, for example, in order to move the entire distance, for example, 10,000 times of driving are required, and as a result, there is a disadvantage that power consumption is not reduced. In addition, since the operation includes uncertain elements, it is difficult to move a certain amount every time a voltage is applied like a stepping motor, and a position sensor is indispensable. In addition, the piezoelectric ultrasonic motor system has a short life due to the drive structure using the frictional force, and there is also a problem that the generated force is small due to the structure when the impact system is used.

  Accordingly, an object of the present invention is to make it possible to reduce the size and thickness while ensuring a sufficient lens moving distance, to reduce power consumption and to have a long life, to ensure a sufficient generation force, and to create a complicated gear mechanism. It is an object of the present invention to provide a lens actuator that can satisfy all the required performances such as no need for a position sensor or a position sensor and excellent response.

As a result of studying the lens actuator mechanism that can satisfy all of the required performance as described above, the present inventors have used a piezoelectric element as a drive source, and the displacement in the uniaxial direction output from the piezoelectric element is transmitted as a displacement. It has been found that the above problem can be solved by transmitting to a lens by a displacement magnifying mechanism having a specific structure having a plurality of levers (lever) arranged along the direction.
The present invention has been made on the basis of such knowledge and has the following gist.

[1] A piezoelectric element (1) that deforms with a deformation amount corresponding to an applied voltage and outputs the deformation as a displacement in a uniaxial direction, a lens holder (3) that can be displaced to adjust a focal length, The lens held by the lens holder (3) and the displacement output from the piezoelectric element (1) are transmitted to the lens holder (3) while increasing the amount of displacement, and the lens holder (3) is displaced. A lens actuator having a displacement magnifying mechanism (2),
The displacement enlarging mechanism (2) includes at least a plurality of levers (20) arranged along the displacement transmission direction as displacement enlarging means, and the plurality of levers (20) sequentially expands the amount of displacement. Lens actuator.

[2] In the lens actuator of [1], the displacement magnifying mechanism (2) includes a fixing portion (21) that supports each lever (20), and each lever (20) is an elastic that forms a fulcrum of the lever. It is supported by the fixed part (21) by being connected to the fixed part (21) via a deformable fulcrum connecting part (22), and is the most upstream between the adjacent levers (20) and in the displacement transmission direction. A lens actuator characterized in that the side lever (20) and the displacement output portion (100) of the piezoelectric element (1) are coupled by a resiliently deformable force point coupling portion (23) that forms the force point of the lever. .
[3] In the lens actuator of [2] above, the distal end portion of the most downstream lever (20) in the displacement transmission direction is connected to or engaged with the lens holder (3), and the displacement of the most downstream lever (20) A lens actuator characterized in that the lens holder (3) is displaced by means of the above.

[4] In the lens actuator of [3] above, the most upstream lever (20) in the displacement transmission direction has a proximal end portion coupled to the fixed portion (21) via the fulcrum coupling portion (22). In addition, the lever (20) other than the most upstream lever (20) is coupled to the displacement output portion (100) of the piezoelectric element (1) via the force point coupling portion (23). Is coupled to the fixed portion (21) via the fulcrum coupling portion (22) and coupled to the tip side portion of another adjacent lever (20) via the force point coupling portion (23). Lens actuator characterized by
[5] In the lens actuator of [4] above, a fulcrum coupling portion (22) coupled to a proximal end portion of at least one lever (20) of the plurality of levers (20) and a force point coupling portion ( 23) is a lens actuator characterized by having a length of 1/4 or more of the length of the lever (20).
[6] The lens actuator according to any one of [1] to [5] above, wherein the displacement magnifying mechanism (2) is formed of a molded body or / and a laminated body made of metal or / and resin. Lens actuator.

[7] In the lens actuator according to any one of [2] to [6], a fulcrum coupling portion (22) coupled to the most downstream lever (20) in the displacement transmission direction among the plurality of levers (20) A lens actuator, wherein a parallel direction of the force point coupling portion (23) is orthogonal to a displacement surface of the lever (20) upstream of the most downstream lever (20).
[8] The lens actuator according to [7], wherein the piezoelectric element (1) and the displacement enlarging mechanism (2) are arranged in a state of surrounding the lens holder (3) in a plan view. .
[9] In the lens actuator of [8] above, the displacement enlarging mechanism (2) includes first and second levers (20), and the lens holder (3) includes the piezoelectric element (1) and the first lever ( 20) A lens actuator characterized in that at least three sides are surrounded by the second lever (20).

[10] In the lens actuator according to any one of [2] to [6], the parallel direction of the fulcrum coupling portion (22) and the force point coupling portion (23) coupled to each of the plurality of levers (20) is A lens actuator characterized by being parallel to a displacement surface of a lever (20) upstream of the lever (20).
[11] In the lens actuator of [10] above, the displacement enlarging mechanism (2) includes first and second levers (20), and the first and second levers (20) and the piezoelectric element (1) are provided. The lens actuator is characterized by surrounding the fixed portion (21) to which the fulcrum coupling portion (22) of the second lever (20) is coupled in three directions.
[12] the above-mentioned [1] - In any of the lens actuator of [11], the length direction center of the lever front end part p ₁ and the fulcrum connecting portion coupled to the lever (20) (20) (22) lens actuator, wherein the sum of all the lever length of the straight line L connecting the p ₂ is greater than or equal to the length of the displacement output direction of the piezoelectric element (1).

[13] In the lens actuator of [2], the displacement magnifying mechanism (2) includes a pair of lever groups (X), (Y) including a plurality of levers (20) arranged along the displacement transmission direction. The longitudinal direction connecting the fixing part (21) supporting the lever (20), the most downstream lever (20) in the displacement transmission direction of both lever groups (X), (Y) and the lens holder (3) And an elastically deformable connecting member (24),
Each lever (20) is supported by the fixed portion (21) by being coupled to the fixed portion (21) via the elastically deformable fulcrum coupling portion (22) that forms the fulcrum of the lever, and adjacent to each other. Between the lever (20) and between the most upstream lever (20) in the displacement transmission direction and the displacement output part (100) of the piezoelectric element (1) are elastically deformable force point coupling parts (23 )
The distal end portion of the most downstream lever (20) in the displacement transmission direction of the pair of lever groups (X) and (Y) and the lens holder (3) are connected by the connecting member (24), and both the most downstream levers are connected. A lens actuator characterized in that the lens holder (3) is displaced via the connecting member (24) by the displacement of (20).

[14] In the lens actuator of [13], the most downstream lever (20) in the displacement transmission direction of the pair of lever groups (X) and (Y) in any one of the following forms (i) to (iii): ) And the lens holder (3) are connected by a connecting member (24).
(I) A pair of connecting members (24) connect both side portions of the lens holder (3) and the distal end portions of the two most downstream levers (20), and the distal ends of the two most downstream levers (20). The lens holder (3) is displaced by moving the side parts so as to approach and separate.
(Ii) The connecting member (24) connects the tip end portions of the two most downstream levers (20), and the intermediate portion of the connecting member (24) is coupled to the lens holder (3), so that both the most downstream levers ( 20) Displace the lens holder (3) by moving the tip side parts closer to and away from each other.
(Iii) A pair of connecting members (24) are respectively installed on the distal end portions of the fixed portion (21) and the two most downstream levers (20), and the intermediate portion of both connecting members (24) is the lens holder (3 The lens holder (3) is displaced by linking or engaging with both sides of the lens) and moving the most downstream levers (20) toward and away from the fixed part (21). Make it work.

[15] In the lens actuator of [13] or [14] above, in each lever group (X), (Y), the most upstream lever (20) in the displacement transmission direction has a base end portion for the fulcrum It is coupled to the fixed part (21) via the coupling part (22), and is coupled to each displacement output part (100) at both ends of the piezoelectric element (1) via the force point coupling part (23). The lever (20) other than the upstream lever (20) has its proximal end portion coupled to the fixed portion (21) via the fulcrum coupling portion (22) and the force point coupling portion (23). A lens actuator, wherein the lens actuator is coupled to a tip side portion of another lever (20) adjacent thereto.
[16] In the lens actuator of [15], in each lever group (X), (Y), a fulcrum coupled to a proximal end portion of at least one lever (20) of the plurality of levers (20) The lens coupling portion (22) and the force point coupling portion (23) have a length that is ¼ or more of the length of the lever (20).

[17] The lens actuator according to any one of [13] to [16], wherein the displacement enlarging mechanism (2) excluding the displacement enlarging mechanism (2) or the connecting member (24) is made of metal or / and resin. A lens actuator comprising a laminated body.
[18] In the lens actuator according to any one of the above [13] to [17], the pair of lever groups (X) and (Y) may be symmetrical with respect to the planar shape and arrangement of the plurality of levers (20). A lens actuator characterized by point symmetry.
[19] In any of the lens actuator of the above-mentioned [13] to [18], each lever groups (X), coupled to the (Y), the tip portion p ₁ and the lever (20) of the lever (20) sum of all the lever length of the straight line L connecting the central longitudinal p ₂ of the fulcrum connecting portion (22), characterized in that at least the length of the displacement output direction of the piezoelectric element (1) Lens actuator.

  Since the lens actuator of the present invention uses a piezoelectric element as a driving source, it consumes less power and has a long life, sufficient generating force and high responsiveness, and no complicated gear mechanism or position sensor is required. There is an advantage of being. Furthermore, a piezoelectric element is used as a drive source, and the uniaxial displacement output from the piezoelectric element is transmitted to the lens holder by a displacement magnifying mechanism having a specific structure including a plurality of levers arranged along the displacement transmission direction. Therefore, a large movement amount of the lens can be ensured while being a small or thin structure. For this reason, it is possible to provide an actuator that can be reduced in size and thickness while ensuring a sufficient movement distance of the lens. In addition, since the displacement enlarging mechanism has no mechanical contact, there is almost no wear and energy loss is small. From this aspect as well, the life and energy efficiency of the lens actuator can be improved.

1 to 5 show an embodiment of a lens actuator according to the present invention. FIG. 1 is an overall perspective view, FIG. 2 is an exploded perspective view, and FIG. 3 is a perspective view with a lens holder removed. Is a plan view, and FIG. 5 is an explanatory view showing a function (operation form). In the figure, reference numeral 3 denotes a lens holder to which a lens (not shown) is attached.
The lens actuator is deformed by a deformation amount corresponding to the applied voltage, and outputs the deformation as a displacement in a uniaxial direction. The displacement output from the piezoelectric element 1 is increased while the displacement amount is increased. A displacement magnifying mechanism 2 that transmits to the holder 3 and moves the lens holder 3 is provided.

  In the present embodiment, in order to make the lens actuator as thin as possible, a structure in which the piezoelectric element 1 and the displacement magnifying mechanism 2 surround the lens holder 3 in a plane, in other words, a piezoelectric element is formed on the outer periphery of the lens holder 3. The element 1 and the displacement magnifying mechanism 2 are arranged. In such a structure, the central space can be accommodated in the lens holder 3 to reduce the thickness of the actuator, and the length of the lever (lever) constituting the displacement magnifying mechanism 2 can be sufficiently secured. Therefore, it is advantageous in obtaining a large displacement enlargement amount. In addition, since there is no member that obstructs the optical axis of the lens, it is advantageous from this point to miniaturization and thinning.

The piezoelectric element 1 is an element that generates dimensional distortion in accordance with an applied drive voltage. (1) Low power consumption and long life (2) Sufficient generation force and high responsiveness can be obtained. (3) All the required performances such as no complicated gear mechanism and position sensor are required.
The piezoelectric element 1 of the present embodiment has a quadrangular prism shape, generates dimensional distortion (displacement) in the longitudinal direction, and outputs this dimensional distortion in a uniaxial direction from the displacement output unit 100 at the tip.
The piezoelectric element 1 is fixed to a fixing portion 21a described later, or is fixed to a container that supports the entire actuator.
The amount of uniaxial displacement that can be output from an extremely small piezoelectric element that is applied to a camera module of a portable terminal is usually about several hundred ppm in a stacked type, and in the present invention, such amount of displacement is about several tens to one hundred times. The lens holder 3 is transmitted to the lens holder 3, and the lens holder 3 is displaced.

The displacement enlarging mechanism 2 includes a plurality of levers 20 arranged along the displacement transmission direction and a fixing portion 21 that supports the lever 20, but the displacement enlarging mechanism 2 of the present embodiment is A first lever 20a (most upstream lever) connected to the distal end (displacement output portion) of the piezoelectric element 1 at a 90 ° relationship with respect to the longitudinal direction of the piezoelectric element 1, and a distal end of the first lever 20a The second lever 20b (most downstream lever) connected in a 90 ° relationship with the longitudinal direction of the lever 20a. The lens holder 3 includes the piezoelectric element 1, the first lever 20a, and the second lever 20a. The lever 20b has a structure in which three sides are surrounded by a U-shape.
The fixing portion 21 includes a fixing portion 21a installed in parallel with the piezoelectric element 1 at a position outside the piezoelectric element 1, and a fixing portion 21b installed in parallel with the lever 21b below the second lever 21b. These fixing portions 21a and 21b are fixed to a container that supports the entire actuator.

  In each embodiment of the present invention to be described below including this embodiment, each lever 20 constituting the displacement magnifying mechanism 2 is supported by a plate-shaped fulcrum coupling portion 22 and a force point coupling portion 23 that are elastically deformable, and Although the fulcrum coupling portion 22 and the force point coupling portion 23 are both plate-shaped, there is little lateral deflection when the lever 20 is actuated. Displacement transmission and expansion can be performed stably.

In the present embodiment, the first lever 20a has a quadrangular prism shape, and a base end portion of the first lever 20a is fixed via an elastically deformable plate-shaped fulcrum coupling portion 22a that forms a fulcrum of the lever. It is coupled to the tip of the portion 21a and is thereby supported by the fixed portion 21a. Further, at a position slightly closer to the lever distal end side than the coupling position of the fulcrum coupling portion 22a, a lever force point is formed between the proximal end portion of the lever 20a and the displacement output portion 100 (driving member distal end) of the piezoelectric element 1. It is connected by a plate-like force point connecting portion 23a that can be elastically deformed.
The fulcrum coupling portion 22a and the force point coupling portion 23a have a relatively short plate shape, and are coupled at right angles to the longitudinal direction of the first lever 20a.

The second lever 20b also has a quadrangular prism shape, and the base end side portion thereof is coupled to the lower fixing portion 21b via the fulcrum coupling portion 22b and the force lever coupling portion 23b. The first lever 20a is coupled to the tip side portion.
The fulcrum coupling portion 22b and the force point coupling portion 23b have a relatively long plate shape, and one end portions thereof are coupled to the base end side portion of the lever 20b along the longitudinal direction of the lever 20b. The other end portion of the force point coupling portion 23b is coupled at right angles to the longitudinal direction of the lever 20a, and the other end portion of the fulcrum coupling portion 22b is coupled to the fixed portion 21b.

  In the displacement magnifying mechanism 2 of the present invention, the fulcrum coupling portion 22 and the force point coupling portion 23 coupled to the proximal end portion of at least one lever 20 of the plurality of levers 20 have the length of the lever 20. It is desirable to have a length of ¼ or more, preferably ３ or more, more preferably ½ or more. In this way, by sufficiently increasing the lengths of the fulcrum coupling portion 22 and the force point coupling portion 23, a large amount of deformation can be obtained while ensuring the rigidity of these coupling portions. This is because the enlargement amount can be increased. In the present embodiment, the fulcrum coupling portion 22b and the force point coupling portion 23b coupled to the proximal end portion of the second lever 20b have a length that is about ½ of the length of the lever 20b. Yes.

  Here, the displacement magnifying mechanism 2 of the present embodiment converts the horizontal displacement of the piezoelectric element 1 into the vertical direction and transmits it to the lens holder 3, and in order to perform the conversion of the displacement direction, the lever 20b. The parallel direction (the arrow (α) direction in FIG. 3) of the fulcrum coupling portion 22b and the force point coupling portion 23b coupled to the (most downstream lever in the displacement transmission direction) is the upstream side lever 20a of the lever 20a. The structure is orthogonal to the displacement surface (displacement surface in the direction of arrow (β) in FIG. 3).

  The distal end portion of the second lever 20b (the most downstream lever in the displacement transmission direction) is connected to or engaged with the lens holder 3, and the lens holder 3 is displaced by the displacement of the lever 20b. In the present embodiment, the lens holder 3 has a plate-shaped attachment portion 31 protruding from the upper end of the ring-shaped main body 30, and both of them are in contact with the upper surface of the lever 20 b. It is connected by being clamped by a character-shaped connecting member 4 (plate spring). In addition, 5 and 6 are presser springs for pressing and holding the upper and lower portions of the lens holder 3.

In the displacement magnifying mechanism 2 of the present invention, in order to increase the displacement magnifying amount as much as possible, it is preferable to make the entire length of the plurality of levers 20 longer. Specifically, as shown in FIG. 4, each lever 20 (20a, 20b). ) of the tip portion _{p 1} and the lever 20 (20a, 20b proximal portion coupled to the fulcrum connecting portion 22 (22a in), 22b) longitudinal center _{p 2} and the connecting straight line L the length of the The total of all levers is preferably equal to or greater than the length of the piezoelectric element 1 in the displacement output direction.

The displacement magnifying mechanism 2 is composed of a molded body or / and a laminated body made of metal (for example, stainless steel) and / or resin. This laminate is a laminate of thin plates. The displacement magnifying mechanism 2 may be composed of a molded body or a laminated body that is integrally molded as a whole. However, in this embodiment, the main portions of the fixed portion 21a and the first lever 20a are an integrally molded body or an integral laminated body. In addition, the fixed portion 21b, the second lever 20b, and the tip portion 25 of the first lever 20a are formed of an integrally molded body or an integrated laminate, and the portion 25 is fixed to the tip side of the lever 20a. Thus, the displacement enlarging mechanism 2 is configured.
Three or more levers 20 constituting the displacement enlarging mechanism 2 may be provided along the displacement transmission direction. For example, in the example of the present embodiment, the first lever 20a and the second lever 20b are provided between the first lever 20a and the second lever 20b. One or more levers having the same principle as the one lever 20a may be provided.

FIG. 5 shows the function (operation form) of the lens actuator of this embodiment.
When a predetermined drive voltage is applied to the piezoelectric element 1, it expands in the direction of the arrow (A) due to dimensional distortion, and a uniaxial displacement is output from the displacement output part 100 to the first lever 20a through the force point coupling part 23a. (That is, push the lever 20a). Thus, the first lever 20a rotates in the direction of the arrow (B) with the fulcrum coupling portion 22a being deformed as a fulcrum. By the rotation of the first lever 20a, the force point coupling portion 23b of the second lever 20b is pulled in the direction of the arrow (C), so that the second lever 20b deforms the fulcrum coupling portion 22b. Using this as a fulcrum, it rotates (rotates upward) in the direction of the arrow (D). Accordingly, the lens holder 3 connected to the tip of the second lever 20b is also displaced (raised) upward. Naturally, when the piezoelectric element 1 is reduced in the direction of the arrow (A), the lens holder 3 is displaced (lowered) downward by the reverse operation. The displacement output from the piezoelectric element 1 is enlarged (amplified) in the process of displacement transmission by the displacement magnifying mechanism 2 as described above, and is more than several tens of times the output displacement amount of the piezoelectric element 1 (in some cases 100 times) The above displacement amount is transmitted to the lens holder 3.

6 to 8 show another embodiment of the lens actuator of the present invention. FIG. 6 is a perspective view with the lens holder removed, FIG. 7 is a side view, and FIG. 8 is an overall perspective view. . In the figure, reference numeral 3 denotes a lens holder to which a lens (not shown) is attached.
The embodiment shown in FIGS. 1 to 5 has a structure in which the piezoelectric element 1 and the displacement magnifying mechanism 2 are arranged on the outer periphery of the lens holder 3 in order to make the lens actuator as thin as possible in a plane. However, in the present embodiment, a vertical type is used in order to minimize the installation area of the lens actuator, and the displacement is transmitted and enlarged on the same surface.

The lens actuator is also deformed by a deformation amount corresponding to the applied voltage, and the piezoelectric element 1 that outputs the deformation as a displacement in a uniaxial direction, and the displacement output from the piezoelectric element 1 is increased while the displacement amount is increased. A displacement enlarging mechanism 2 that transmits to the lens holder 3 and moves the lens holder 3 is provided.
The piezoelectric element 1 has a quadrangular prism shape, generates dimensional distortion (displacement) in the longitudinal direction, and outputs the dimensional distortion from the displacement output unit 100 at the tip in a uniaxial direction.

  The displacement magnifying mechanism 2 includes a plurality of levers 20 arranged along the displacement transmission direction and a fixing portion 21 that supports the levers 20. The fixing portion 21 includes upper and lower horizontal fixing portions 21c and 21d having appropriate intervals, and a fixing portion 21e that couples the fixing portions 21c and 21d with a part thereof. The piezoelectric element 1 of the present embodiment is positioned between the upper and lower fixed portions 21c and 21d, and is held horizontally by the fixed portion 21e via its rear end portion. The fixing portions 21 c and 21 d form a gap with the piezoelectric element 1 and are positioned in parallel above and below the piezoelectric element 1. The upper fixing portion 21 c is longer than the piezoelectric element 1. In addition, the fixing | fixed part 21 is fixed to the container which supports the whole actuator.

  The displacement magnifying mechanism 2 of the present embodiment is connected to the tip (displacement output portion) of the piezoelectric element 1 in the longitudinal direction in a relationship of 90 ° with respect to the longitudinal direction of the piezoelectric element 1 and extends upward. A lever 20a (the most upstream lever) is connected to the tip of the first lever 20a at a 90 ° relationship with respect to the longitudinal direction of the lever 20a, and extends horizontally in a state substantially parallel to the piezoelectric element 1. 2 levers 20b (the most downstream lever).

The first lever 20a is relatively short, and its proximal end portion is coupled to the distal end of the fixed portion 21d via an elastically deformable plate-shaped fulcrum coupling portion 22a that forms a fulcrum of the lever. Is supported by the fixing portion 21d. Further, at a position slightly closer to the lever distal end side than the coupling position of the fulcrum coupling portion 22a, a lever force point is formed between the proximal end portion of the lever 20a and the displacement output portion 100 (driving member distal end) of the piezoelectric element 1. It is connected by a plate-like force point connecting portion 23a that can be elastically deformed.
The fulcrum coupling portion 22a and the force point coupling portion 23a are coupled at right angles to the longitudinal direction of the first lever 20a.

The second lever 20b has a relatively long rectangular column shape and is disposed above the fixed portion 21c. The second lever 20b has a base end portion coupled to the distal end portion of the fixed portion 21c via a fulcrum coupling portion 22b, and the first lever 20a via the force point coupling portion 23b. It is connected to the tip side part.
The fulcrum coupling portion 22b and the force point coupling portion 23b have a relatively long plate shape, and one end portions thereof are coupled to the base end side portion of the lever 20b along the longitudinal direction of the lever 20b. The other end portion of the force point coupling portion 23b is coupled at right angles to the longitudinal direction of the lever 20a, and the other end portion of the fulcrum coupling portion 22b is coupled to the fixing portion 21c. In the present embodiment, the fulcrum coupling portion 22b and the force point coupling portion 23b coupled to the proximal end portion of the second lever 20b have a length that is 1/2 or more of the length of the lever 20b. Yes.
The second lever 20b and the fulcrum coupling portion 22b and the force point coupling portion 23b coupled to the second lever 20b are arranged in parallel with the fixed portion 21c so as to form a gap.

  Here, the displacement magnifying mechanism 2 of the present embodiment is for a fulcrum coupled to the second lever 20b (the most downstream lever in the displacement transmission direction) so that the displacement is transmitted and enlarged on the same surface. The parallel direction of the coupling portion 22b and the force point coupling portion 23b is parallel to the displacement surface of the lever 20a on the upstream side of the lever 20b. Further, in such a structure, the first lever 20a, the second lever 20b, and the piezoelectric element 1 form a gap between the fixing portion 21c to which the fulcrum coupling portion 22b of the second lever 20b is coupled. It has a compact structure (folded structure) surrounded by three sides.

The distal end portion of the second lever 20b (the most downstream lever in the displacement transmission direction) is connected to or engaged with the lens holder 3, and the lens holder 3 is displaced by the displacement of the lever 20b. In the present embodiment, the lens holder 3 has a mounting portion 32 protruding from the upper end of a plate-like main body 30 having a lens mounting hole in the center, and this mounting portion 32 is connected (fixed) to the upper surface of the lever 20b. ing.
Three or more levers 20 constituting the displacement enlarging mechanism 2 may be provided along the displacement transmission direction. For example, in the example of the present embodiment, the first lever 20a and the second lever 20b are provided between the first lever 20a and the second lever 20b. One or more levers having the same principle as the one lever 20a may be provided.
The other configurations relating to the piezoelectric element 1, the displacement magnifying mechanism 2 and the like are the same as those in the embodiment of FIGS.

  In the lens actuator of the present embodiment, when a predetermined driving voltage is applied to the piezoelectric element 1, the piezoelectric actuator 1 expands in the direction of the arrow (A) due to dimensional distortion, and the uniaxial displacement from the displacement output unit 100 is first transmitted through the force point coupling unit 23a. 1 is output to the first lever 20a (that is, the lever 20a is pushed). As a result, the first lever 20a rotates outward (arrow (B) direction) with the fulcrum coupling portion 22a being deformed as a fulcrum. By the rotation of the first lever 20a, the force point coupling portion 23b of the second lever 20b is pulled in the direction of the arrow (C), so that the second lever 20b deforms the fulcrum coupling portion 22b. With this as a fulcrum, it rotates upward (arrow (D) direction). Accordingly, the lens holder 3 connected to the tip of the second lever 20b is also displaced (raised) upward. Naturally, when the piezoelectric element 1 is reduced in the direction of the arrow (A), the lens holder 3 is displaced (lowered) downward by the reverse operation. The displacement output from the piezoelectric element 1 is enlarged (amplified) in the process of displacement transmission by the displacement magnifying mechanism 2 as described above, and is more than several tens of times the output displacement amount of the piezoelectric element 1 (in some cases 100 times) The above displacement amount is transmitted to the lens holder 3.

9 to 11 show another embodiment of the lens actuator of the present invention, which is a modification of the embodiment of FIGS. 9 is a perspective view with the lens holder removed, FIG. 10 is a side view, and FIG. 11 is an overall perspective view.
This embodiment is characterized by the structure of the second lever 20b and the fixing portion 21d that supports the second lever 20b with respect to the embodiments of FIGS. That is, the second lever 20b is longer than the embodiment of FIGS. 6 to 8 and has a length equal to or longer than the length of the piezoelectric element 1. A step portion 200 is formed at an upper portion of an intermediate portion of the lever 20b (substantially central portion in the longitudinal direction in the present embodiment). The intermediate portion in the longitudinal direction where the step portion 200 is formed and the distal end side of the first lever 20a. The portions are coupled by a force point coupling portion 23b. On the other hand, the length of the fixing portion 21c is considerably shorter than the length of the piezoelectric element 1 (preferably about 2/3 to 1/2 of the length of the piezoelectric element 1), and the tip of the fixing portion 21c and the lever 20b. Are coupled by a fulcrum coupling portion 22b substantially parallel to the lever 20b.

In such an embodiment, since the second lever 20b is long, and the force point coupling portion 23b and the fulcrum coupling portion 22b are sufficiently long (approximately half the length of the lever 20b), the displacement expansion amount can be increased. There is a big advantage.
Although not as compact as the embodiments of FIGS. 6 to 8, the displacement magnifying mechanism 2 of this embodiment also includes the first lever 20a, the second lever 20b, and the piezoelectric element 1 of the second lever 20b. The fixed portion 21c to which the fulcrum coupling portion 22b is coupled has a compact structure (folded structure) in which a gap is formed and surrounded in three directions.
Other configurations and basic functions are the same as those of the embodiment of FIGS.

12 to 14 show another embodiment of the lens actuator of the present invention, which is a modification of the embodiment of FIGS. 12 is a perspective view with the lens holder removed, FIG. 13 is a plan view, and FIG. 14 is a side view.
Also in this embodiment, in order to make the lens actuator as thin as possible, a structure in which the piezoelectric element 1 and the displacement magnifying mechanism 2 surround the lens holder 3 in a planar manner, that is, the piezoelectric element is provided on the outer periphery of the lens holder 3. 1 and a displacement magnifying mechanism 2 are arranged.
The piezoelectric element 1 is fixed to a fixing portion 21a described later, or is fixed to a container that supports the entire actuator.

The displacement enlarging mechanism 2 includes a plurality of levers 20 arranged along the displacement transmission direction and a fixing portion 21 that supports the lever 20, but the displacement enlarging mechanism 2 of the present embodiment is A first lever 20a (most upstream lever) connected to the distal end (displacement output portion) of the piezoelectric element 1 at a 90 ° relationship with respect to the longitudinal direction of the piezoelectric element 1, and a distal end of the first lever 20a The second lever 20b (most downstream lever) connected in a 90 ° relationship with the longitudinal direction of the lever 20a. The lens holder 3 includes the piezoelectric element 1, the first lever 20a, and the second lever 20a. The lever 20b has a structure in which three sides are surrounded by a U-shape.
The fixing portion 21 includes a fixing portion 21a installed in parallel with the piezoelectric element 1 at an inner position of the piezoelectric element 1, and a fixing portion 21b installed in parallel with the lever 21b on the inner side of the second lever 21b. The fixing 21 including the fixing portions 21a and 21b is fixed to a container that supports the entire actuator.

The first lever 20a has a quadrangular prism shape, and a base end portion of the first lever 20a is attached to the distal end of the fixed portion 21a via an elastically deformable plate-shaped fulcrum coupling portion 22a that forms a fulcrum of the lever. It couple | bonds and is supported by the fixing | fixed part 21a by this. Further, at a position slightly closer to the rear end of the lever than the coupling position of the fulcrum coupling portion 22a, the lever force point is set between the proximal end portion of the lever 20a and the displacement output portion 100 (piezoelectric element distal end) of the piezoelectric element 1. The elastically deformable plate-shaped force point connecting portion 23a is formed. The coupling position relationship between the fulcrum coupling portion 22a and the force point coupling portion 23a with respect to the lever 20a as described above is the reverse of the embodiment shown in FIGS.
The fulcrum coupling portion 22a and the force point coupling portion 23a have a relatively short plate shape, and are coupled at right angles to the longitudinal direction of the first lever 20a.

The second lever 20b also has a quadrangular prism shape, and its proximal end portion is coupled to the end portion of the fixed portion 21b near the lever 20a via the fulcrum coupling portion 22b, and the force point coupling portion. The first lever 20a is coupled to the distal end portion of the first lever 20a through 23b.
The fulcrum coupling portion 22b and the force point coupling portion 23b have a relatively long plate shape, and one end portions thereof are coupled to the base end side portion of the lever 20b along the longitudinal direction of the lever 20b. The other end portion of the force point coupling portion 23b is coupled at right angles to the longitudinal direction of the lever 20a, and the other end portion of the fulcrum coupling portion 22b is coupled to the fixing portion 21b via the horizontal portion 220. ing.

In the present embodiment, the fulcrum coupling portion 22b and the force point coupling portion 23b coupled to the proximal end portion of the second lever 20b have a length equal to or greater than the length of the lever 20b.
1 to 5, the displacement magnifying mechanism 2 of the present embodiment converts the horizontal displacement of the piezoelectric element 1 into the vertical direction and transmits it to the lens holder 3. In order to change the displacement direction, the parallel direction of the fulcrum coupling portion 22b and the force point coupling portion 23b coupled to the lever 20b (the most downstream lever in the displacement transmission direction) is the lever 20a upstream of the lever 20b. The structure is orthogonal to the displacement plane.

The tip side portion of the second lever 20b (the most downstream lever in the displacement transmission direction)
As in the embodiment of FIGS. 1 to 5, the lens holder 3 is connected or engaged with the lens holder 3 and the lens holder 3 is displaced by the displacement of the lever 20b.
Three or more levers 20 constituting the displacement enlarging mechanism 2 may be provided along the displacement transmission direction. For example, in the example of the present embodiment, the first lever 20a and the second lever 20b are provided between the first lever 20a and the second lever 20b. One or more levers having the same principle as the one lever 20a may be provided.
The other configurations relating to the piezoelectric element 1, the displacement magnifying mechanism 2 and the like are the same as those in the embodiment of FIGS.

  In the lens actuator of the present embodiment, when a predetermined driving voltage is applied to the piezoelectric element 1, the piezoelectric actuator 1 expands in the direction of the arrow (A) due to dimensional distortion, and the uniaxial displacement from the displacement output unit 100 is first transmitted through the force point coupling unit 23a. 1 is output to the first lever 20a (that is, the lever 20a is pushed). Here, since the force point coupling portion 23a is coupled to the lever rear end side with respect to the fulcrum coupling portion 22a, the first lever 20a deforms the fulcrum coupling portion 22a and uses it as a fulcrum in the inner direction ( It rotates in the direction of arrow (B). By the rotation of the first lever 20a, the force point coupling portion 23b of the second lever 20b is pushed out in the direction of the second lever 20b (arrow (C) direction), so that the second lever 20b becomes a fulcrum. The connecting portion 22b is deformed and rotated upward (in the direction of the arrow (D)) using this as a fulcrum. Accordingly, the lens holder 3 connected to the tip of the second lever 20b is also displaced (raised) upward. Naturally, when the piezoelectric element which is the piezoelectric element 1 is reduced in the direction of the arrow (A), the lens holder 3 is displaced (lowered) downward by the reverse operation. The displacement output from the piezoelectric element 1 is enlarged (amplified) in the process of displacement transmission by the displacement magnifying mechanism 2 as described above, and is more than several tens of times the output displacement amount of the piezoelectric element 1 (100 times in some cases). The above displacement amount is transmitted to the lens holder 3.

15 to 17 show another embodiment of the lens actuator of the present invention. FIG. 15 is a plan view with the lens holder removed, FIG. 16 is a plan view, and FIG. 17 is a schematic side view. In the figure, reference numeral 3 denotes a lens holder to which a lens (not shown) is attached.
The lens actuator is also deformed by a deformation amount corresponding to the applied voltage, and the piezoelectric element 1 that outputs the deformation as a displacement in a uniaxial direction, and the displacement output from the piezoelectric element 1 is increased while the displacement amount is increased. The displacement enlarging mechanism 2 that transmits to the lens holder 3 and displaces the lens holder 3 is provided. The displacement enlarging mechanism 2 includes a pair of levers 20 arranged along the displacement transmission direction. The lever groups X and Y, the fixing portion 21 that supports the lever 20, the most downstream lever 20 in the displacement transmission direction of the lever groups X and Y, and the lens holder 3 can be elastically deformed in the longitudinal direction. And a connecting member 24.

  In the present embodiment as well, the structure in which the piezoelectric element 1 and the displacement magnifying mechanism 2 surround the lens holder 3 in plan view in order to make the lens actuator as thin as possible as in the embodiments of FIGS. In other words, the piezoelectric element 1 and the displacement magnifying mechanism 2 are arranged on the outer periphery of the lens holder 3. As described above, in such a structure, not only can the actuator be thinned by using the central space as the accommodation space for the lens holder 3, but also the length of the lever (lever) constituting the displacement magnifying mechanism 2 can be reduced. Since it can be sufficiently secured, it is advantageous in obtaining a large displacement expansion amount. In addition, since there is no member that obstructs the optical axis of the lens, it is advantageous from this point to miniaturization and thinning.

On the other hand, the actuator of the present embodiment with respect to each of the above-described embodiments is characterized in that the lens holder 3 can be stably held and displaced by having a pair of left and right lever groups X and Y. Since the connecting member 24 that can be elastically deformed as well as 20 has a displacement expansion function, the entire displacement expansion amount can be increased accordingly.
The piezoelectric element 1 has a quadrangular prism shape, generates dimensional distortion (displacement) in the longitudinal direction, and outputs this dimensional distortion from the displacement output units 100 at both ends in a uniaxial direction. The piezoelectric element 1 is fixed to a container that supports the entire actuator.

The fixed portion 21 is placed at the center of the actuator, and the lens holder 3 is disposed above it. The piezoelectric element 1 is disposed on the side portion of the fixed portion 21. The fixing portion 21 is fixed to a container that supports the entire actuator.
In the pair of lever groups X and Y, the planar shape and arrangement of the plurality of levers 20 are axisymmetric with respect to the actuator center, and the lever 20 on the most downstream side connects the lens holder 3 via the connecting member 24. It is structured to be held from both sides.
Each lever group X, Y is connected in the horizontal direction to a first lever 20a (most upstream lever) connected to one end (displacement output portion) of the piezoelectric element 1 and to the tip of the first lever 20a. And a second lever 20b (the most downstream lever).

The first lever 20a is configured in an L shape in the longitudinal direction (in the figure, 201 is an L-shaped first side, 202 is a second side), and the L-shaped of both lever groups X, Y The lever 20a is arranged in a gate shape. In each of the lever groups X and Y, the first lever 20a is coupled at its base end portion to the fixing portion 21 via an elastically deformable plate-shaped fulcrum coupling portion 22a that forms a fulcrum of the lever. Thereby, it is supported by the fixing portion 21. Further, at a position slightly closer to the rear end of the lever than the coupling position of the fulcrum coupling portion 22a, the elasticity between the proximal end portion of the lever 20a and the displacement output portion 100 at each end of the piezoelectric element 1 forms a lever power point. They are coupled by a deformable plate-shaped force point coupling portion 23a.
The fulcrum coupling portion 22a and the force point coupling portion 23a have a relatively short plate shape, and are coupled at right angles to the longitudinal direction of the L-shaped first side portion 201 of the first lever 20a.

The second lever 20b is disposed inside the first side 201 of the first lever 20a in parallel with the part of the first side in the horizontal direction, and the base end side portion is connected to the fulcrum It is coupled to the fixed portion 21 via the portion 22b, and is coupled to the tip side portion of the first lever 20a via the force point coupling portion 23b.
The fulcrum coupling portion 22b and the force point coupling portion 23b have a relatively long plate shape and are arranged on the inner side of the second side portion 202 of the first lever 20a in parallel with the second side portion. Are coupled to the base end side portion of the lever 20b at right angles to the longitudinal direction of the lever 20b. The other end portion of the force point coupling portion 23b is coupled to the tip of the lever 20a via the horizontal portion 221. The other end portion of the fulcrum coupling portion 22b is a fixed portion on the opposite side to the drive member 1. 21 is coupled to the side.
The fulcrum coupling portion 22b and the force point coupling portion 23b coupled to the proximal end portion of the second lever 20b have substantially the same length as the lever 20b.

The tip side portion of the second lever 20b (the most downstream lever in the displacement transmission direction) of each lever group X and Y and the lens holder 3 are connected by a connecting member 24 that can be elastically deformed in the longitudinal direction. The lever 20b and the connecting member 24 are held from both sides.
The connecting member 24 is made of an elastically deformable member such as a leaf spring, and a high-rigidity portion 240 for preventing buckling (a portion having higher rigidity than the other portions) is provided in the middle portion in the longitudinal direction. Further, both side portions of the highly rigid portion 240 are configured to be elastically deformed. In the present embodiment, the lens holder 3 is pushed up or down while the connecting member 24 is elastically deformed by moving the tip side portions of the most downstream levers 20b of both lever groups X and Y to approach and separate from each other. The holder 3 is displaced up and down.

In this embodiment, each lever groups X, the Y, each lever 20 (20a, 20b) of the distal end portion _{p 1} and the lever 20 (20a, 20b) of the proximal portion to coupled the fulcrum connecting portion 22 (22a, 22b) the sum of all the lever length of the straight line L connecting the central longitudinal p ₂ of, is preferably at least the length of the displacement output direction of the piezoelectric element 1.
Three or more levers 20 constituting the lever groups X and Y of the displacement magnifying mechanism 2 may be provided along the displacement transmission direction. For example, in the example of the present embodiment, the first lever 20a and the second lever 20 are provided. One or more levers having the same principle as the first lever 20a may be provided between the levers 20b.
The other configurations relating to the piezoelectric element 1, the displacement magnifying mechanism 2 and the like are the same as those in the embodiment of FIGS.

  In the lens actuator of this embodiment, when a predetermined drive voltage is applied to the piezoelectric element 1, the piezoelectric element 1 expands in the direction of the arrow (A) due to dimensional distortion, and the uniaxial displacement from the displacement output portions 100 at both ends of the piezoelectric element 1 is for the power point. The signals are output to the first levers 20a of both lever groups X and Y through the coupling portion 23a (that is, the levers 20a are pushed). Here, since the force point coupling portion 23a is coupled to the lever rear end side with respect to the fulcrum coupling portion 22a, the first lever 20a deforms the fulcrum coupling portion 22a and uses it as a fulcrum in the inner direction ( It rotates in the direction of arrow (B). By the rotation of the first lever 20a, the force point coupling portion 23b of the second lever 20b is pulled in the direction of the arrow (C), so that the second lever 20b deforms the fulcrum coupling portion 22b. With this as a fulcrum, it rotates in the outer direction (arrow (D) direction). As a result, both connecting members 24 are pulled outward, so that the lens holder 3 held by the connecting members 24 is displaced (lowered) downward. Naturally, if the piezoelectric element 1 is reduced in the direction of the arrow (A), the lens holder 3 is displaced (raised) upward by the reverse operation. The displacement output from the piezoelectric element 1 is enlarged (amplified) in the process of displacement transmission by the displacement magnifying mechanism 2 as described above, and is more than several tens of times the output displacement amount of the piezoelectric element 1 (100 times in some cases). The above displacement amount is transmitted to the lens holder 3.

18 to 20 show another embodiment of the lens actuator of the present invention. FIG. 18 is a perspective view with the lens holder removed, FIG. 19 is a side view, and FIG. 20 is an overall perspective view. . In the figure, reference numeral 3 denotes a lens holder to which a lens (not shown) is attached.
Similarly to the embodiment of FIGS. 15 to 17, the lens actuator is also deformed by a deformation amount corresponding to the applied voltage, and the piezoelectric element 1 that outputs the deformation as a displacement in the uniaxial direction is output from the piezoelectric element 1. And a displacement magnifying mechanism 2 for transmitting the displacement to the lens holder 3 while enlarging the amount of displacement and displacing the lens holder 3, and the displacement magnifying mechanism 2 is arranged along the displacement transmission direction. A pair of lever groups X and Y composed of a plurality of levers 20, a fixing portion 21 that supports the levers 20, the most downstream lever 20 in the displacement transmission direction of both lever groups X and Y, and the lens holder 3 are connected. And a connecting member 24 that is elastically deformable in the longitudinal direction.

  Therefore, the feature of the actuator of this embodiment with respect to each embodiment shown in FIGS. 1 to 14 is that the lens holder 3 can be stably held and displaced by having a pair of lever groups X and Y. What can be done is that not only the lever 20 but also the elastically deformable connecting member 24 has a displacement expanding function, so that the entire displacement expanding amount can be increased accordingly. However, in the embodiment shown in FIGS. 15 to 17 described above, the lens actuator has a structure that can be thinned in a plane, but this embodiment is intended to reduce the installation area of the lens actuator. It is a vertical type. Further, in the embodiment of FIGS. 15 to 17, the planar shape and arrangement of the plurality of levers 20 of the pair of lever groups X and Y are made symmetrical with respect to a line, whereas this is made point symmetrical in the vertical direction. ing.

The piezoelectric element 1 has a quadrangular prism shape, generates dimensional distortion (displacement) in the longitudinal direction, and outputs this dimensional distortion from the displacement output units 100 at both ends in a uniaxial direction.
The fixing portion 21 has a fixing portion 21 f located below the piezoelectric element 1 and a fixing portion 21 g located above the piezoelectric element 1. The fixing portions 21 f and 21 g form a gap with the piezoelectric element 1 and are positioned in parallel above and below the piezoelectric element 1.
The fixing portion 21f is fixed to a container that supports the entire actuator. On the other hand, the fixed portion 21g may be fixed to the body that supports the entire actuator by being connected to the fixed portion 21f directly or via a connecting portion, or the fulcrum connecting portion 22b of both lever groups X and Y. May be held in a doubly supported manner.

In the pair of lever groups X and Y, the shape and arrangement of the plurality of levers 20 are point-symmetric with respect to the actuator center, and the levers 20 on the most downstream side are connected by a connecting member 24. The lens holder 3 is held.
Each lever group X, Y is connected to each end (displacement output portion) of the piezoelectric element 1 in the longitudinal direction at a relationship of 90 ° with respect to the longitudinal direction of the piezoelectric element 1 and extends upward. 20a (the most upstream lever) is connected to the tip of the first lever 20a at a 90 ° relationship with respect to the longitudinal direction of the lever 20a and extends horizontally in a state substantially parallel to the piezoelectric element 1. Lever 20b (the most downstream lever).

In each lever group X, Y, the first lever 20a has an end portion of the fixed portion 21f via a resiliently deformable plate-shaped fulcrum coupling portion 22a that forms a fulcrum of the lever. By this, it is supported by the fixing | fixed part 21f. Further, at a position slightly closer to the lever tip than the coupling position of the fulcrum coupling portion 22a, the elasticity between the proximal end portion of the lever 20a and the displacement output portion 100 at each end portion of the piezoelectric element 1 forms a lever power point. They are coupled by a deformable plate-shaped force point coupling portion 23a.
The fulcrum coupling portion 22a and the force point coupling portion 23a have a relatively short plate shape, and are coupled at right angles to the longitudinal direction of the first lever 20a.

The second lever 20b is disposed above the fixed portion 21g at the end opposite to the end on the lever 20a arrangement side of each lever group X, Y in the drive member longitudinal direction. The second lever 20b has a base end portion at the end portion of the fixing portion 21g via the fulcrum coupling portion 22b (the end portion on the lever 20a arrangement side of each lever group X, Y in the piezoelectric element longitudinal direction). ) And a tip end portion of the first lever 20a via a force point connecting portion 23b.
The fulcrum coupling portion 22b and the force point coupling portion 23b have a relatively long plate shape, and one end portions thereof are coupled to the base end side portion of the lever 20b along the longitudinal direction of the lever 20b. The other end portion of the force point coupling portion 23b is coupled at right angles to the longitudinal direction of the lever 20a, and the other end portion of the fulcrum coupling portion 22b is coupled to the fixed portion 21g.

The fulcrum coupling portion 22b and the force point coupling portion 23b coupled to the proximal end portion of the second lever 20b have a length that is several times the length of the lever 20b.
The second lever 20b and the fulcrum coupling portion 22b and the force point coupling portion 23b coupled to the second lever 20b are arranged in parallel with the fixed portion 21g so as to form a gap.
In the present embodiment, the first lever 20a, the second lever 20b, and the piezoelectric element 1 form a fixed portion 21g to which the fulcrum coupling portion 22b of the second lever 20b is coupled in three directions while forming a gap. The enclosed compact structure (folding structure).

The distal end portions of the second levers 20b (the most downstream levers in the displacement transmission direction) of each lever group X and Y are connected by a connecting member 24 that is elastically deformable in the longitudinal direction, and an intermediate portion of the connecting member 24 is Coupled to the lens holder 3.
The connecting member 24 is made of an elastically deformable member such as a leaf spring, and is formed in a mountain shape having a very small inclination in the longitudinal direction, and has a flat portion 241 at the top of the central portion in the longitudinal direction. Both ends of the connecting member 24 are coupled to the distal end portion of the second lever 20b (the most downstream lever in the displacement transmission direction) of each lever group X, Y, and connect the two.

In the present embodiment, the lens holder 3 has a mounting portion 32 protruding from the upper end of a plate-like main body 30 having a lens mounting hole in the center, and the mounting portion 32 is flat at the center in the longitudinal direction of the connecting member 24. It is connected (fixed) to the part 241.
In the present embodiment, the connecting member 24 is elastically deformed and the height of the flat portion 241 is changed by performing a displacement in which the distal end portions of the most downstream levers 20a of both lever groups X and Y are moved toward and away from each other. The lens holder 3 held here is moved up and down.

Three or more levers 20 constituting each lever group X, Y of the displacement magnifying mechanism 2 may be provided along the displacement transmission direction. For example, in the example of this embodiment, the first lever 20a and the second lever 20 are provided. One or more levers having the same principle as the first lever 20a may be provided between the levers 20b.
The other configurations relating to the piezoelectric element 1, the displacement magnifying mechanism 2 and the like are the same as those in the embodiment of FIGS.

  In the lens actuator of this embodiment, when a predetermined drive voltage is applied to the piezoelectric element 1, the piezoelectric element 1 expands in the direction of the arrow (A) due to dimensional distortion, and the uniaxial displacement from the displacement output portions 100 at both ends of the piezoelectric element 1 is for the power point. The signals are output to the first levers 20a of both lever groups X and Y through the coupling portion 23a (that is, the levers 20a are pushed). As a result, the first lever 20a rotates outward (arrow (B) direction) with the fulcrum coupling portion 22a being deformed as a fulcrum. By the rotation of the first lever 20a, the force point coupling portion 23b of the second lever 20b is pulled in the direction of the arrow (C), so that the second lever 20b deforms the fulcrum coupling portion 22b. With this as a fulcrum, it rotates in the direction of the arrow (D). As a result, the distance between both ends of the connecting member 24 is shortened, so that the connecting member 24 is elastically deformed, the height of the flat portion 241 is raised, and the lens holder 3 connected thereto is displaced (raised) upward. Naturally, when the piezoelectric element 1 is reduced in the direction of the arrow (A), the lens holder 3 is displaced (lowered) downward by the reverse operation. The displacement output from the piezoelectric element 1 is enlarged (amplified) in the process of displacement transmission by the displacement magnifying mechanism 2 as described above, and is more than several tens of times the output displacement amount of the piezoelectric element 1 (in some cases 100 times) The above displacement amount is transmitted to the lens holder 3.

FIGS. 21 to 23 show other embodiments of the lens actuator of the present invention, which are modified examples of the embodiments of FIGS. 18 to 20. FIG. 21 is a perspective view with the lens holder removed, FIG. 22 is a plan view, and FIG. 23 is an overall perspective view. In the figure, reference numeral 3 denotes a lens holder to which a lens (not shown) is attached.
The piezoelectric element 1 and the displacement magnifying mechanism 2 of this embodiment are obtained by changing the configuration of the connecting member 24 from the embodiment of FIGS.

  The lens actuator is also deformed by a deformation amount corresponding to the applied voltage, and the piezoelectric element 1 that outputs the deformation as a displacement in a uniaxial direction, and the displacement output from the piezoelectric element 1 is increased while the displacement amount is increased. A displacement magnifying mechanism 2 that transmits to the holder 3 and moves the lens holder 3 is provided. The displacement magnifying mechanism 2 includes a pair of lever groups X including a plurality of levers 20 arranged along the displacement transmission direction. , Y, a fixing portion 21 that supports the lever 20, and a connecting member 24 that is elastically deformable in the longitudinal direction connecting the most downstream lever 20 and the lens holder 3 in the displacement transmitting direction of the two lever groups X, Y. Is provided.

The piezoelectric element 1 has a quadrangular prism shape, generates dimensional distortion (displacement) in the longitudinal direction, and outputs this dimensional distortion from the displacement output units 100 at both ends in a uniaxial direction.
The fixing portion 21 has fixing portions 21h and 21i positioned on both sides in the width direction of the piezoelectric element 1, and a fixing portion 21j positioned facing the lever 20 with a lens holder installation space in between. The fixing portions 21h and 21i form a gap with the piezoelectric element 1 and are positioned in parallel on both sides of the piezoelectric element 1, respectively. Of these fixing portions 21h and 21i, at least the fixing portion 21h is fixed to the container body 7 that supports the entire actuator.

In the pair of lever groups X and Y, the shape and arrangement of the plurality of levers 20 are point-symmetric with respect to the actuator center, and a connecting member 24 is coupled to the lever 20 on the most downstream side. The member 3 is held.
Each lever group X, Y is connected to each end (displacement output portion) of the piezoelectric element 1 in the horizontal direction in a relationship of 90 ° with respect to the longitudinal direction of the piezoelectric element 1 (the most upstream side). Lever) and a second lever 20b (most downstream lever) connected to the tip of the first lever 20a at a 90 ° relationship with respect to the longitudinal direction of the lever 20a.

In each lever group X, Y, the first lever 20a has an end portion of the fixed portion 21h through a resiliently deformable plate-shaped fulcrum coupling portion 22a that forms a fulcrum of the lever. By this, it is supported by the fixing | fixed part 21h. Further, at a position slightly closer to the lever tip than the coupling position of the fulcrum coupling portion 22a, the elasticity between the proximal end portion of the lever 20a and the displacement output portion 100 at each end portion of the piezoelectric element 1 forms a lever power point. They are coupled by a deformable plate-shaped force point coupling portion 23a.
The fulcrum coupling portion 22a and the force point coupling portion 23a have a relatively short plate shape, and are coupled at right angles to the longitudinal direction of the first lever 20a.

The second lever 20b is disposed outside the fixed portion 21i at the end opposite to the end on the lever 20a arrangement side of each lever group X, Y in the drive member longitudinal direction. As for this 2nd lever 20b, the base end side part is the edge part (the edge part by the side of the lever 20a arrangement | positioning of each lever group X, Y in the piezoelectric element longitudinal direction) via the coupling | bond part 22b for fulcrum. ) And a tip end portion of the first lever 20a via a force point connecting portion 23b.
The fulcrum coupling portion 22b and the force point coupling portion 23b have a relatively long plate shape, and one end portions of the fulcrum coupling portion 22b and the proximal end portion of the lever 20b are coupled so as to be substantially along the longitudinal direction of the lever 20b. .
The fulcrum coupling portion 22b and the force point coupling portion 23b coupled to the proximal end portion of the second lever 20b have a length that is approximately twice the length of the lever 20b.

A pair of connecting members 24 that are elastically deformable in the longitudinal direction are installed between the distal end portion of the second lever 20b (the most downstream lever in the displacement transmission direction) of the lever group X and Y and the fixing portion 21j. Has been.
The connecting member 24 is made of an elastically deformable member such as a leaf spring, is configured in a mountain shape having a small inclination in the longitudinal direction, and has a support portion 242 at the top of the central portion in the longitudinal direction. The connecting member 24 is bridged between the distal end portion of the lever 20b and the fixing portion 21j so that the top of the mountain faces upward. In addition, a rigid member 243 for preventing buckling is attached at an interval in the longitudinal direction of the connecting member 24, and the connecting member 24 is elastically deformed mainly at a portion other than the rigid member 243.
In the present embodiment, the lens holder 3 has mounting portions 33 protruding on both sides of the ring-shaped main body 30, and the mounting portions 33 are connected to or engaged with the support portion 242 in the center in the longitudinal direction of the connecting member 24. Thus, the lens holder 3 is supported by the connecting member 24.

In the present embodiment, the connecting member 24 is elastically deformed by the displacement of the distal end portion of the second lever 20a of both lever groups X, Y approaching / separating from the fixed portion 21j, and the support portion 242 thereof. The lens holder 3 held here is displaced up and down.
Three or more levers 20 constituting each lever group X, Y of the displacement magnifying mechanism 2 may be provided along the displacement transmission direction. For example, in the example of this embodiment, the first lever 20a and the second lever 20 are provided. One or more levers having the same principle as the first lever 20a may be provided between the levers 20b.
The other configurations relating to the piezoelectric element 1, the displacement magnifying mechanism 2 and the like are the same as those in the embodiment of FIGS.

  In the lens actuator of this embodiment, when a predetermined drive voltage is applied to the piezoelectric element 1, the piezoelectric element 1 expands in the direction of the arrow (A) due to dimensional distortion, and the uniaxial displacement from the displacement output portions 100 at both ends of the piezoelectric element 1 is for the power point. The signals are output to the first levers 20a of both lever groups X and Y through the coupling portion 23a (that is, the levers 20a are pushed). As a result, the first lever 20a rotates outward (arrow (B) direction) with the fulcrum coupling portion 22a being deformed as a fulcrum. By the rotation of the first lever 20a, the force point coupling portion 23b of the second lever 20b is pulled in the direction of the arrow (C), so that the second lever 20b deforms the fulcrum coupling portion 22b. With this as a fulcrum, it rotates in the direction of the arrow (D). As a result, the distance between the distal end portion of the second lever 20b and the fixed portion 21j is shortened, so that the connecting member 24 is elastically deformed and the height of the support portion 242 is raised, and the lens holder 3 held here is moved upward. Displace (rise). Naturally, when the piezoelectric element 1 is reduced in the direction of the arrow (A), the lens holder 3 is displaced (lowered) downward by the reverse operation. The displacement output from the piezoelectric element 1 is enlarged (amplified) in the process of displacement transmission by the displacement magnifying mechanism 2 as described above, and is more than several tens of times the output displacement amount of the piezoelectric element 1 (in some cases 100 times) The above displacement amount is transmitted to the lens holder 3.

24 to 26 show another embodiment of the lens actuator of the present invention, which is a modification of the embodiment of FIGS. 24 is a perspective view with the lens holder removed, FIG. 25 is a plan view, and FIG. 26 is an overall perspective view.
This embodiment uses a connecting member 24 (connecting member 24 that can be elastically deformed in the longitudinal direction) of a type different from the embodiment shown in FIGS. The connecting member 24 includes a support plate portion whose main body 245 is made of an elastically deformable member such as a leaf spring, is configured in a mountain shape having a small inclination in the longitudinal direction, and is elastically deformable at the top of the central portion in the longitudinal direction. 246 has a projecting structure. Note that a rigid member 243 for preventing buckling is attached to a part of the main body 245 of the connecting member 24, and the main body 245 is elastically deformed mainly at a portion other than the rigid member 243.

The pair of connecting members 24 are installed between the distal end portion of the second lever 20b of both the lever groups X and Y and the fixing portion 21j so that the tops of the peaks face each other. In this state, the support plate portions 246 of both the connecting members 24 face each other so as to face obliquely upward. Then, the lens holder 3 is supported by the connecting member 24 by connecting or engaging the mounting portions 33 on both sides of the main body 30 of the lens holder 3 to the support plate portion 246 at the center in the longitudinal direction of the connecting member 24.
In the present embodiment, the top portions of the two connecting members 24 are moved closer to and away from each other by moving the distal end portion of the second lever 20b of both lever groups X and Y toward and away from the fixed portion 21j. Along with this, the support plate 246 is elastically deformed and the lens holder 3 is pushed up or down to move the lens holder 3 up and down.

1 is an overall perspective view showing an embodiment of a lens actuator of the present invention. 1 is an exploded perspective view of the embodiment of FIG. The perspective view of the state which removed the lens holder in embodiment of FIG. The top view of the state which removed the lens holder in embodiment of FIG. Explanatory drawing which shows the function (operation form) of embodiment of FIG. The other embodiment of the lens actuator of this invention is shown, and the perspective view of the state which removed the lens holder The side view of the state which removed the lens holder in embodiment of FIG. Overall perspective view of the embodiment of FIG. The other embodiment of the lens actuator of this invention is shown, and the perspective view of the state which removed the lens holder The side view of the state which removed the lens holder in embodiment of FIG. Overall perspective view of the embodiment of FIG. The other embodiment of the lens actuator of this invention is shown, and the perspective view of the state which removed the lens holder Top view of the embodiment of FIG. Side view of the embodiment of FIG. The other embodiment of the lens actuator of this invention is shown, The top view of the state which removed the lens holder Plan view of the embodiment of FIG. Schematic side view of the embodiment of FIG. The other embodiment of the lens actuator of this invention is shown, and the perspective view of the state which removed the lens holder The side view of the state which removed the lens holder in embodiment of FIG. Overall perspective view of the embodiment of FIG. The other embodiment of the lens actuator of this invention is shown, and the perspective view of the state which removed the lens holder The top view of the state which removed the lens holder in embodiment of FIG. Overall perspective view of the embodiment of FIG. The other embodiment of the lens actuator of this invention is shown, and the perspective view of the state which removed the lens holder The top view of the state which removed the lens holder in embodiment of FIG. Overall perspective view of the embodiment of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Piezoelectric element 2 Displacement expansion mechanism 3 Lens holder 4 Connection member 5,6 Spring for presser 7 Body 20a, 20b Lever 21,21a-21j Fixing part 22a, 22b Connection part for fulcrum 23a, 23b Connection part for force points 24 Connection member 25 parts 30 body 31, 32, 33 mounting part 100 displacement output part 200 step part 201 first side part 202 second side part 220, 221 horizontal part 240 high rigidity part 241 flat part 242 support part 243 rigid member 245 body 246 Support plate X, Y lever group

Claims (19)

A piezoelectric element (1) that deforms with a deformation amount corresponding to an applied voltage and outputs the deformation as a displacement in a uniaxial direction, a lens holder (3) that can be displaced to adjust a focal length, and the lens holder ( 3) A displacement enlarging mechanism for transmitting the lens held by 3) and the displacement output from the piezoelectric element (1) to the lens holder (3) while enlarging the displacement amount, and displacing the lens holder (3). (2) a lens actuator comprising:
The displacement enlarging mechanism (2) includes at least a plurality of levers (20) arranged along the displacement transmission direction as displacement enlarging means, and the plurality of levers (20) sequentially expands the amount of displacement. Lens actuator. The displacement enlarging mechanism (2) includes a fixing portion (21) that supports each lever (20),
Each lever (20) is supported by the fixed portion (21) by being coupled to the fixed portion (21) via an elastically deformable fulcrum coupling portion (22) that forms a fulcrum of the lever, Between the levers (20) adjacent to each other and between the most upstream lever (20) in the displacement transmission direction and the displacement output part (100) of the piezoelectric element (1), the elastically deformable force point coupling part (the force point coupling part) 23. The lens actuator according to claim 1, wherein the lens actuator is coupled in 23).   The distal end portion of the most downstream lever (20) in the displacement transmission direction is connected to or engaged with the lens holder (3), and the lens holder (3) is displaced by the displacement of the most downstream lever (20). The lens actuator according to claim 2.   The most upstream lever (20) in the displacement transmission direction has its base end portion coupled to the fixed portion (21) via the fulcrum coupling portion (22) and via the force point coupling portion (23). The lever (20) other than the most upstream lever (20) is coupled to the displacement output portion (100) of the piezoelectric element (1), and the base end portion of the lever (20) is interposed via the fulcrum coupling portion (22). 4. The lens actuator according to claim 3, wherein the lens actuator is coupled to the fixed portion (21) and is coupled to a tip side portion of another lever (20) adjacent thereto via a force point coupling portion (23). .   The fulcrum coupling portion (22) and the force point coupling portion (23) coupled to the proximal end portion of at least one lever (20) of the plurality of levers (20) are the length of the lever (20). The lens actuator according to claim 4, wherein the lens actuator has a length equal to or greater than ¼.   The lens actuator according to any one of claims 1 to 5, wherein the displacement enlarging mechanism (2) is formed of a molded body or / and a laminated body made of metal or / and resin.   The parallel direction of the fulcrum coupling portion (22) and the force point coupling portion (23) coupled to the most downstream lever (20) in the displacement transmission direction among the plurality of levers (20) is the most downstream lever (20 The lens actuator according to any one of claims 2 to 6, wherein the lens actuator is orthogonal to a displacement surface of the lever (20) on the upstream side.   The lens actuator according to claim 7, wherein the piezoelectric element (1) and the displacement magnifying mechanism (2) are arranged in a state of surrounding the lens holder (3) in a plan view.   The displacement enlarging mechanism (2) includes first and second levers (20), and the lens holder (3) includes a piezoelectric element (1), a first lever (20), and a second lever (20). The lens actuator according to claim 8, wherein at least three sides are enclosed.   The parallel direction of the fulcrum coupling portion (22) and the force point coupling portion (23) coupled to each of the plurality of levers (20) is parallel to the displacement surface of the lever (20) upstream of the lever (20). The lens actuator according to claim 2, wherein the lens actuator is a lens actuator.   The displacement enlarging mechanism (2) includes first and second levers (20), and the first and second levers (20) and the piezoelectric element (1) are used as fulcrums for the second lever (20). The lens actuator according to claim 10, wherein the fixed portion (21) to which the coupling portion (22) is coupled is surrounded in three directions. Lever sum of all the lever length of the straight line L connecting the tip portion p ₁ and the fulcrum connecting portion coupled to the lever (20) in (22) and a central longitudinal p ₂ (20) is a piezoelectric element The lens actuator according to any one of claims 1 to 11, wherein the lens actuator has a length in the displacement output direction of (1). The displacement magnifying mechanism (2) includes a pair of lever groups (X), (Y) including a plurality of levers (20) arranged along the displacement transmission direction, and a fixing portion that supports the lever (20) ( 21) and a connecting member (24) that is elastically deformable in the longitudinal direction connecting the most downstream lever (20) in the displacement transmission direction of both lever groups (X) and (Y) and the lens holder (3). Prepared,
Each lever (20) is supported by the fixed portion (21) by being coupled to the fixed portion (21) via the elastically deformable fulcrum coupling portion (22) that forms the fulcrum of the lever, and adjacent to each other. Between the lever (20) and between the most upstream lever (20) in the displacement transmission direction and the displacement output part (100) of the piezoelectric element (1) are elastically deformable force point coupling parts (23 )
The distal end portion of the most downstream lever (20) in the displacement transmission direction of the pair of lever groups (X) and (Y) and the lens holder (3) are connected by the connecting member (24), and both the most downstream levers are connected. The lens actuator according to claim 2, wherein the lens holder (3) is displaced through the connecting member (24) by the displacement of (20). In the form of any of the following (i) to (iii), the tip end portion of the most downstream lever (20) in the displacement transmission direction of the pair of lever groups (X), (Y) and the lens holder (3) The lens actuator according to claim 13, wherein the lens actuators are connected by a connecting member (24).
(I) A pair of connecting members (24) connect both side portions of the lens holder (3) and the distal end portions of the two most downstream levers (20), and the distal ends of the two most downstream levers (20). The lens holder (3) is displaced by moving the side parts so as to approach and separate.
(Ii) The connecting member (24) connects the tip end portions of the two most downstream levers (20), and the intermediate portion of the connecting member (24) is coupled to the lens holder (3), so that both the most downstream levers ( 20) Displace the lens holder (3) by moving the tip side parts closer to and away from each other.
(Iii) A pair of connecting members (24) are respectively installed on the distal end portions of the fixed portion (21) and the two most downstream levers (20), and the intermediate portion of both connecting members (24) is the lens holder (3 The lens holder (3) is displaced by linking or engaging with both sides of the lens) and moving the most downstream levers (20) toward and away from the fixed part (21). Make it work.   In each lever group (X), (Y), the most upstream lever (20) in the displacement transmission direction has its proximal end portion coupled to the fixed portion (21) via the fulcrum coupling portion (22). In addition, the levers (20) other than the most upstream lever (20) are coupled to the displacement output portions (100) at both ends of the piezoelectric element (1) via the force point coupling portion (23). The end side part is connected to the fixed part (21) via the fulcrum connection part (22), and is connected to the tip side part of another adjacent lever (20) via the force point connection part (23) The lens actuator according to claim 13 or 14, wherein:   In each lever group (X), (Y), a fulcrum coupling portion (22) coupled to a proximal end portion of at least one lever (20) of the plurality of levers (20) and a force point coupling portion ( The lens actuator according to claim 15, wherein 23) has a length equal to or more than ¼ of a length of the lever (20).   The displacement enlarging mechanism (2) excluding the displacement enlarging mechanism (2) or the connecting member (24) is composed of a molded body or / and a laminated body made of metal or / and resin. The lens actuator according to any one of the above.   The pair of lever groups (X), (Y) is characterized in that the planar shape and arrangement of the plurality of levers (20) are line symmetric or point symmetric. Lens actuator. Each lever groups (X), in (Y), a straight line connecting the distal portion p ₁ and the central longitudinal p ₂ of the fulcrum connecting portion coupled to the lever (20) (22) of the lever (20) L The lens actuator according to any one of claims 13 to 18, wherein the total length of all the levers is equal to or greater than the length of the piezoelectric element (1) in the displacement output direction.

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