JP2005312244A - Drive unit, three-dimensional drive unit, and camera module - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To drive a driven body in a plane without causing the interference of two actuators while using a simple constitution. <P>SOLUTION: The driving force of a first drive source 29a with a first direction as a driving direction is transmitted to the driven body 21 via a first elastic spring 24a, and the driving force of a second drive source 29b with a second direction orthogonal to the first direction as a driving direction is transmitted to the driven body 21 via a second elastic spring 24b. The rigidity of the first elastic spring 24a is large in the first direction, and small in the second direction. The rigidity of the second elastic spring 24b is large in the second direction, and small in the first direction. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a drive device. In particular, the present invention relates to a drive device that can be preferably used to drive an optical lens or an image sensor. The present invention also relates to a camera module provided with this driving device.

  Conventionally, in a camera module composed of a lens system and an image sensor that is mounted on a camera that acquires video, video is shot by driving the lens constituting the lens system in a direction perpendicular to the optical axis of the lens system. Techniques for reducing the effects of camera shake that sometimes occur are known.

  Also, a technique for adjusting the focus of an image by changing the relative position between the lens system and the image sensor in a direction parallel to the optical axis of the lens system is widely used.

  In the optical system having the above-described camera shake correction function, since it is necessary to drive the lens in a direction perpendicular to the optical axis at high speed and with high precision, conventionally, a voice coil type driving device, a DC motor, and a reduction gear are used. The drive device which consists of was used.

  FIG. 11 is a perspective view showing an example of an optical system (anti-vibration optical system) having a conventional camera shake correction function (see Patent Document 1). In this anti-vibration optical system, the correction lens 1 is driven in a first direction perpendicular to the optical axis of the optical system by a first actuator comprising a magnet 2a and a coil 3a, and a second actuator comprising a magnet 2b and a coil 3b. Is driven in a second direction orthogonal to the optical axis of the optical system and the first direction. The amount of movement of the lens 1 in the first direction and the second direction is controlled by changing the current flowing through the coils 3a and 3b. The first and second actuators are voice coil type actuators that use the force generated by the interaction between the magnets 2a, 2b and the coils 3a, 3b. In addition, a DC motor and a speed reducer are combined. It is also possible to use an actuator.

  In this image stabilization optical system, one of the first and second actuators does not affect the other, so that each actuator can be driven independently.

  However, the first and second actuators require a magnet and a coil, and therefore it is difficult to reduce the volume of the actuator. If the volume of the actuator is reduced, the generated driving force is drastically reduced, so that the desired camera shake correction effect cannot be realized. That is, a large volume is required to obtain a driving force necessary for camera shake correction, and it is difficult to reduce the size of the camera shake correction apparatus.

  A surface acoustic wave motor is known as an actuator that does not use magnets and coils (see Patent Document 2). FIG. 12A is a plan view showing a schematic configuration of a conventional surface acoustic wave motor, and FIG. 12B is a side view thereof. Drive electrodes (IDT) 11a and 11b are formed on the surface of a piezoelectric surface acoustic wave substrate 10 such as lithium niobate. Further, the moving body 12 is pressed onto the surface of the surface acoustic wave substrate 10 with a predetermined pressure F, and the surface acoustic wave substrate 10 and the moving body 12 are frictionally coupled. As shown in FIG. 13, a plurality of protrusions 14 are formed on the lower surface of the moving body 12. The apex of the protrusion 14 is in contact with the surface of the surface acoustic wave substrate 10.

  By applying a high frequency voltage (several to several tens of MHz) to the drive electrodes 11a and 11b, a surface acoustic wave propagating only in the vicinity of the surface of the surface acoustic wave substrate 10 is generated, and a minute vibration of several nm obtained by the high frequency is generated. The moving body 12 to which the pressurizing pressure F is applied can be moved in one direction.

  In the case where camera shake correction is performed using such a surface acoustic wave motor, the following configuration is conceivable. That is, two surface acoustic wave motors are arranged so that their driving directions are orthogonal to each other and also to the optical axis of the optical system, and the movable body 12 of each surface acoustic wave motor is used as a correction lens for the optical system. Combine with.

  However, the surface acoustic wave substrate 10 and the moving body 12 are frictionally coupled, and their relative positions are held by frictional force except during driving. Therefore, the frictional force between the surface acoustic wave substrate 10 of one surface acoustic wave motor and the moving body 12 acts to suppress the drive of the other surface acoustic wave motor. Thus, since the two surface acoustic wave motors interfere with each other, it is actually difficult to drive the correction lens in a plane using them.

  Patent Document 3 discloses a drive device that drives a driven body in a plane by combining two actuators that perform linear drive. This drive device is configured as follows. The second frame is held on the first frame via an elastic spring, and the driven body is held on the second frame via an elastic spring. The first actuator drives the second frame in the first direction relative to the first frame, and the second actuator drives the driven body in the second direction relative to the second frame. With such a configuration, the driven body can be driven in a plane without considering mutual interference between the first actuator and the second actuator.

  However, in such a drive device, the first and second frames are mechanically complex. Further, the first actuator needs to drive all of the second frame, the second actuator, and the driven body, and there is a problem that a large driving force is required.

Furthermore, when the above-mentioned conventional driving device that drives the driven body in a plane orthogonal to the optical axis is applied to drive the driven body also in the optical axis direction, it is necessary to provide a new actuator. It has been difficult to reduce the size and thickness of the driving device.
JP 2000-227614 A Japanese Patent Laid-Open No. 9-233865 Japanese Patent Laid-Open No. 10-285475

  A first object of the present invention is to provide a drive device that can drive a driven body in a plane without interference of two actuators, although it has a simple configuration.

  A second object of the present invention is to provide a driving device that can drive a driven body in a plane with a simple configuration, has excellent impact resistance against external force, and has high reliability.

  A third object of the present invention is to provide a driving device for realizing a three-dimensional driving device that three-dimensionally drives a driven body with a simple configuration.

  Furthermore, the present invention provides a camera module that includes a lens system, an image sensor, and a drive device that changes the relative position of the lens system in a plane perpendicular to the optical axis of the lens system and that can be reduced in size and thickness. This is the fourth purpose.

  The present invention also provides a camera module that includes a lens system, an image sensor, and a drive device that changes the relative position of the lens system in a direction parallel to the optical axis of the lens system and that can be reduced in size and thickness. This is the fifth purpose.

  A first driving device of the present invention includes a first driving source having a first direction as a driving direction, a second driving source having a second direction orthogonal to the first direction as a driving direction, and the first driving source. A first elastic spring that transmits the driving force to the driven body, and a second elastic spring that transmits the driving force of the second drive source to the driven body, and the rigidity of the first elastic spring is: The second elastic spring is large in the first direction and small in the second direction, and the rigidity of the second elastic spring is large in the second direction and small in the first direction.

  The second driving device of the present invention includes a first driving source having a first direction as a driving direction, a second driving source having a second direction orthogonal to the first direction as a driving direction, and the first driving device. A first elastic spring that transmits the driving force of the second driving device to the driven body, a second elastic spring that transmits the driving force of the second driving device to the driven body, the first driving source, and the second driving source. And a driven substrate connected to the fixed substrate via a third elastic spring.

  The third drive device according to the present invention includes a pair of uniaxial drive sources arranged so that the respective drive directions are on the same straight line, and an elasticity spanned between the respective movable bodies of the pair of uniaxial drive sources. And a connecting means for connecting the elastic body and the driven body, wherein the driven body is driven in a direction perpendicular to the driving direction of the uniaxial driving source.

  The first camera module of the present invention includes a lens system including at least one lens, an image sensor, and at least one lens constituting the lens system or the image sensor that is perpendicular to the optical axis of the lens system. A camera module having a shape that bends light at least two surfaces included in the lens system, wherein the driving device is the first or second drive of the present invention. It is a device.

  The second camera module of the present invention includes a lens system including at least one lens, an image sensor, and at least one lens constituting the lens system or the image sensor parallel to at least the optical axis of the lens system. A camera module having a shape in which at least two surfaces included in the lens system bend light, and the drive device is perpendicular to the drive direction of the uniaxial drive source. The third drive device according to the present invention is characterized in that the direction is arranged parallel to the optical axis.

  According to the first driving apparatus of the present invention, the driven body is driven in the first direction and the second direction without the interference between the first driving source and the second driving source, although the configuration is simple. A drive device can be provided.

  According to the second driving device of the present invention, it is possible to drive the driven body in the first direction and the second direction with a simple configuration, which is excellent in impact resistance against external force and has high reliability. Can be provided.

  According to the third driving apparatus of the present invention, it is possible to provide a driving apparatus for realizing a three-dimensional driving apparatus that three-dimensionally drives the driven body with a simple configuration.

  According to the first camera module of the present invention, it is possible to provide a camera module that has a camera shake correction function or a zoom function and can be reduced in size and thickness.

  According to the second camera module of the present invention, it is possible to provide a camera module that has a focus function and can be reduced in size and thickness.

  A first driving device of the present invention includes a first driving source having a first direction as a driving direction, a second driving source having a second direction orthogonal to the first direction as a driving direction, and the first driving source. A first elastic spring that transmits the driving force to the driven body, and a second elastic spring that transmits the driving force of the second drive source to the driven body, and the rigidity of the first elastic spring is: Large in the first direction and small in the second direction, the rigidity of the second elastic spring is large in the second direction and small in the first direction.

  Accordingly, the driven body can be driven in the first direction and the second direction without the first driving source and the second driving source interfering with each other. Therefore, for example, an actuator having a holding force using a surface acoustic wave can be used as the first drive source and the second drive source. As a result, a small and thin two-dimensional drive device can be realized with a simple configuration.

  The second driving device of the present invention includes a first driving source having a first direction as a driving direction, a second driving source having a second direction orthogonal to the first direction as a driving direction, and the first driving device. A first elastic spring that transmits the driving force of the second driving device to the driven body, a second elastic spring that transmits the driving force of the second driving device to the driven body, the first driving source, and the second driving source. And a driven substrate connected to the fixed substrate via a third elastic spring.

  As a result, when an actuator having a holding force using, for example, a surface acoustic wave is used as the first drive source and the second drive source, the position of the driven body is greatly shifted even when an external impact is applied. There is no. Therefore, it is excellent in impact resistance against external force and reliability is improved.

  In the second driving device of the present invention, the rigidity of the first elastic spring is large in the first direction and small in the second direction, and the rigidity of the second elastic spring is large in the second direction. The first direction is preferably small.

  Accordingly, the driven body can be driven in the first direction and the second direction without the first driving source and the second driving source interfering with each other. Therefore, for example, an actuator having a holding force using a surface acoustic wave can be used as the first drive source and the second drive source. As a result, a small and thin two-dimensional drive device can be realized with a simple configuration.

  In the second driving device of the present invention, it is preferable that the rigidity of the third elastic spring in the first direction is the same as the rigidity in the second direction.

  Thereby, the load for driving the driven body in the first direction and the second direction can be made the same, and a two-dimensional drive device with good controllability can be realized.

  In the first and second drive devices of the present invention described above, it is preferable that each of the first drive source and the second drive source includes an actuator using a surface acoustic wave.

  Thereby, the miniaturization and thickness reduction of a drive device are realizable.

  Alternatively, in the first and second drive devices of the present invention, it is preferable that each of the first drive source and the second drive source includes an actuator using a piezoelectric element.

  Thereby, the miniaturization of the drive device can be realized.

  The third drive device according to the present invention includes a pair of uniaxial drive sources arranged so that the respective drive directions are on the same straight line, and an elasticity spanned between the respective movable bodies of the pair of uniaxial drive sources. And a connecting means for connecting the elastic body and the driven body, and the driven body is driven in a direction perpendicular to the driving direction of the uniaxial driving source.

  As a result, the driven body can be driven in a direction perpendicular to the driving direction of the uniaxial driving source, so that a driving device having a small size in the direction in which the driven body is driven can be realized.

  In the third driving device of the present invention, it is preferable that the driven body is further driven in a direction parallel to a driving direction of the uniaxial driving source.

  As a result, a small and thin driving device capable of driving the driven body in two orthogonal directions can be realized. Therefore, by using a plurality of the driving devices, it is possible to realize a three-dimensional driving device that three-dimensionally drives the driven body with a simple configuration.

  In the third driving device of the present invention, the moving bodies of the pair of uniaxial driving sources are moved in opposite directions to move the driven body in a direction perpendicular to the driving direction of the uniaxial driving source. It is preferable to drive.

  Thereby, the drive device which drives a to-be-driven body in the direction orthogonal to the drive direction of a uniaxial drive source is realizable with a small and simple composition.

  Further, in the third drive device of the present invention described above, by moving the movable bodies of the pair of uniaxial drive sources in the same direction, the driven body is parallel to the drive direction of the uniaxial drive source. Is preferably driven.

Accordingly, the driving body that drives the driven body in two orthogonal directions can be realized with a small and simple configuration. In the third driving device of the present invention, the uniaxial driving source is an actuator that uses a surface acoustic wave. It is preferable to include.

  Thereby, the miniaturization and thickness reduction of a drive device are realizable.

  Alternatively, in the third drive device of the present invention, the uniaxial drive source preferably includes an actuator using a piezoelectric element.

  Thereby, the miniaturization of the drive device can be realized.

  The driven body is driven in three axial directions orthogonal to each other by using one or a plurality of the third driving devices of the present invention arranged such that the driving directions of the pair of uniaxial driving sources are orthogonal to each other. A three-dimensional drive device may be realized.

  Thereby, the dimension in the direction orthogonal to the plane including the drive direction of the uniaxial drive source constituting one set or a plurality of sets of third drive devices is small, and a small three-dimensional drive device as a whole can be realized.

  In the above three-dimensional drive device, it is preferable that the uniaxial drive source includes an actuator using a surface acoustic wave.

  As a result, it is possible to reduce the size and thickness of the three-dimensional drive device.

  Alternatively, in the above three-dimensional drive device, the uniaxial drive source preferably includes an actuator using a piezoelectric element.

  Thereby, the miniaturization of the three-dimensional drive device can be realized.

  The first camera module of the present invention includes a lens system including at least one lens, an image sensor, and at least one lens constituting the lens system or the image sensor that is perpendicular to the optical axis of the lens system. A camera module having a shape that bends light at least two surfaces included in the lens system, wherein the driving device is the first or second drive according to the present invention. It is a device.

  Accordingly, it is possible to provide a camera module that has a camera shake correction function or a zoom function and can be reduced in size and thickness.

  The second camera module of the present invention includes a lens system including at least one lens, an image sensor, and at least one lens constituting the lens system or the image sensor parallel to at least the optical axis of the lens system. A camera module having a shape in which at least two surfaces included in the lens system bend light, and the drive device is perpendicular to the drive direction of the uniaxial drive source. The third drive device according to the present invention is characterized in that the direction is arranged parallel to the optical axis.

  According to the second camera module of the present invention, it is possible to provide a camera module that has a focus function and can be reduced in size and thickness.

  In the first and second camera modules, the driving device may drive the lens. Alternatively, the driving device may drive the image sensor.

  Furthermore, the third camera module of the present invention includes a lens system including at least one lens, an image sensor, and at least one lens constituting the lens system or the image sensor as an optical axis of the lens system. A camera module having a shape in which at least two surfaces included in the lens system bend light; and a three-dimensional drive device that drives in a vertical direction and a direction parallel to the optical axis. The apparatus is the above-described three-dimensional drive apparatus of the present invention.

  Accordingly, it is possible to provide a camera module that has a focus function, a camera shake correction function, or a zoom function and that can be reduced in size and thickness.

  In the third camera module, the three-dimensional driving device may drive the lens. Alternatively, the three-dimensional drive device may drive the image sensor.

  Hereinafter, the present invention will be described in more detail with reference to embodiments.

(Embodiment 1)
1A is a plan view of a camera module according to Embodiment 1 of the present invention, and FIG. 1B is a cross-sectional view taken along a plane including the optical axis of the lens system. The camera module according to the first embodiment includes a lens 28 and an image sensor 21 disposed so as to face the lens 28. The lens 28 forms an image on the image sensor 21 by bending light from the subject. As shown in the drawing, an XYZ three-dimensional orthogonal coordinate system is set in which the axis parallel to the optical axis of the lens 28 is the Z axis. In FIG. 1A, the lens 28 is not shown so that the configuration of the driving device can be clearly understood.

  The first substrate 20a to which the image sensor 21 is fixed is connected to the second substrate 20b via the bidirectional elastic springs 25a and 25b, and the second substrate 20b is fixed to the fixed substrate 15 at a fixing point 27. The bi-directional elastic springs 25a and 25b have the same and small rigidity in the X direction and the Y direction as a whole, and can be easily deformed in the XY plane. Therefore, the first substrate 20a and the image pickup device 21 mounted thereon can be easily displaced in the X direction and the Y direction with respect to the fixed substrate 15.

  Around the first substrate 20a, first and second surface acoustic wave actuators 29a and 29b for uniaxial driving are arranged. The first surface acoustic wave actuator 29a is arranged so that its driving direction is parallel to the X axis, and the second surface acoustic wave actuator 29b is arranged so that its driving direction is parallel to the Y axis.

  The first and second surface acoustic wave actuators 29a and 29b have surface acoustic wave substrates 23a and 23b made of a piezoelectric material. The surface acoustic wave substrates 23 a and 23 b are fixed to the fixed substrate 15. Interdigital drive electrodes 22a and 22b are formed on the upper surface of the surface acoustic wave substrate 23a so as to be separated from each other, and interdigital drive electrodes 22c and 22d are formed on the upper surface of the surface acoustic wave substrate 23b so as to be separated from each other. Has been. The moving body 26a is pressed to a region between the drive electrodes 22a and 22b on the upper surface of the surface acoustic wave substrate 23a with a predetermined pressure, and the surface acoustic wave substrate 23a and the moving body 26a are frictionally coupled. Similarly, the moving body 26b is pressed with a predetermined pressure in a region between the drive electrodes 22c and 22d on the upper surface of the surface acoustic wave substrate 23b, and the surface acoustic wave substrate 23b and the moving body 26b are frictionally coupled. A plurality of minute protrusions are formed on the surfaces of the moving bodies 26a, 26b facing the surface acoustic wave substrates 23a, 23b.

  The moving body 26a is connected to the first substrate 20a via the Y-direction elastic spring 24a, and the moving body 26b is connected to the first substrate 20a via the X-direction elastic spring 24b. The Y-direction elastic spring 24a has low Y-direction rigidity and high X-direction rigidity. Accordingly, the rigidity between the moving body 26a and the first substrate 20a is low in the Y direction and high in the X direction. The X-direction elastic spring 24b has low rigidity in the X direction and high rigidity in the Y direction. Therefore, the rigidity between the moving body 26b and the first substrate 20a is low in the X direction and high in the Y direction.

  In such a configuration, by applying a high frequency (several to several tens of MHz) to the drive electrodes 22a and 22b and / or the drive electrodes 22c and 22d, the surface acoustic wave substrate 23a and / or the surface acoustic wave substrate 23b are brought close to the surface. The movable body 26a and / or the movable body 26b to which the pressurized pressure is applied can be moved by generating a surface acoustic wave that only propagates and using a minute vibration of several nm obtained by the high frequency. The moving body 26a driven along the X direction drives the image sensor 21 as a driven body in the X direction via the Y direction elastic spring 24a. In addition, the moving body 26b driven along the Y direction drives the imaging element 21 that is a driven body in the Y direction via the X-direction elastic spring 24b.

  At this time, the Y-direction elastic spring 24a and the X-direction elastic spring 24b have high rigidity in one direction but low rigidity in a direction orthogonal thereto, so that the first actuator 29a moves the image sensor 21 in the X direction. When driving, the frictional force between the surface acoustic wave substrate 23b of the second actuator 29b and the moving body 26b hardly restricts the displacement of the image sensor 21 in the X direction. Similarly, when the second actuator 29b drives the image sensor 21 in the Y direction, the frictional force between the surface acoustic wave substrate 23a of the first actuator 29a and the moving body 26a hardly causes the displacement of the image sensor 21 in the Y direction. There is no limit. That is, the first and second actuators 29a and 29b move the image pickup element 21 as the driven body in the X and Y directions without interfering with each other even though the positions of the moving bodies 26a and 26b are held by frictional coupling. It is possible to drive freely.

  In addition, since the bidirectional elastic springs 25 a and 25 b are interposed between the first substrate 20 a and the fixed point 27, the image sensor 21 is restrained in the X direction and the Y direction with respect to the fixed point 27. Driven without.

  Since the Y-direction elastic spring 24a, the X-direction elastic spring 24b, and the bi-directional elastic springs 25a and 25b are interposed between the first substrate 20a and the fixed substrate 15, external force (impact force) is applied to the camera module. ) Hardly acts on the friction coupling portions of the first and second actuators 29a and 29b, and the relative positions of the moving bodies 26a and 26b with respect to the surface acoustic wave substrates 23a and 23b are almost zero. It does not change. Therefore, a highly reliable camera module having excellent impact resistance can be realized.

  FIG. 2 is a block diagram of a drive circuit that drives the drive electrodes 22a to 22d of the camera module according to the first embodiment.

  The position of the image sensor 21 is detected by the image sensor position detection sensor 38 by an optical method. On the other hand, the image sensor position determining means 37 outputs an image sensor position command value from the specifications of the image to be captured based on the video signal from the image sensor 21. For example, an image sensor position command value for moving the image sensor 21 in the X direction by 1/2 pixel with respect to the current position is output.

  The current position information from the image sensor position detection sensor 38 and the image sensor position command value from the image sensor position determination unit 37 are compared, and based on the difference information, the X direction driving force calculation unit 34 performs imaging in the X direction. The Y-direction driving force calculation means 35 calculates the driving force for the image sensor 21 in the Y direction.

  The output signal from the X direction driving force calculating means 34 is input to the driving electrode X1 driving means 30 and the driving electrode X2 driving means 31. The output signal from the Y-direction driving force calculating means 35 is input to the driving electrode Y1 driving means 32 and the driving electrode Y2 driving means 33. A high-frequency signal from the high-frequency generating means 36 is also input to these driving means 30 to 33. Based on these input signals, the drive electrode X1 drive unit 30 generates a signal to be applied to the drive electrode 22a, and the drive electrode X2 drive unit 31 generates a signal to be applied to the drive electrode 22b, thereby driving the drive electrode Y1 drive unit. 32 generates a signal to be applied to the drive electrode 22c, and the drive electrode Y2 drive means 33 generates a signal to be applied to the drive electrode 22d. As a result, the first and second actuators 29a and 29b finely drive the image sensor 21 in the X direction and the Y direction.

  In the above embodiment, the image sensor 21 is driven in the XY plane, but the lens 28 may be driven in the XY plane.

  According to this embodiment, for example, a small and thin camera module having a camera shake correction function or an optical zoom function can be realized.

(Embodiment 2)
FIG. 3 is a perspective view of a camera module equipped with the three-dimensional drive device according to the second embodiment of the present invention, and FIG. 4 is a plan view of the camera module equipped with the three-dimensional drive device according to the second embodiment of the present invention. is there. The camera module according to the second embodiment includes a lens and an image sensor 40 that is disposed to face the lens. 3 and 4, the illustration of the lens is omitted so that the configuration of the imaging device 40 and the three-dimensional driving device that drives the imaging device 40 can be understood well. The lens forms an image on the image sensor 40 by bending light from the subject. As shown in the drawing, an XYZ-3D orthogonal coordinate system is set in which the axis parallel to the optical axis of the lens is the Z axis.

  First to fourth surface acoustic wave actuators 49 a to 49 d are arranged on the surface of the fixed substrate 45 so as to surround the imaging device 40. The first surface acoustic wave actuator 49a and the third surface acoustic wave actuator 49c are arranged to face each other with the image pickup element 40 interposed therebetween, and these perform biaxial driving in the X direction and the Z direction. The second surface acoustic wave actuator 49b and the fourth surface acoustic wave actuator 49d are arranged to face each other with the image pickup element 40 interposed therebetween, and these perform biaxial driving in the Y direction and the Z direction.

  The basic configurations of the first to fourth surface acoustic wave actuators 49a to 49d are common and are as follows.

  The first surface acoustic wave actuator 49a is composed of two surface acoustic wave actuators 49a1 and 49a2 that perform uniaxial driving, the drive axes of which are arranged in a straight line and parallel to the X axis. The second surface acoustic wave actuator 49b includes two surface acoustic wave actuators 49b1 and 49b2 that perform uniaxial driving, the drive axes of which are arranged in a straight line and parallel to the Y axis. The third surface acoustic wave actuator 49c includes two surface acoustic wave actuators 49c1 and 49c2 that perform uniaxial driving, the drive axes thereof being arranged in a straight line and parallel to the X axis. The fourth surface acoustic wave actuator 49d is configured by two surface acoustic wave actuators 49d1 and 49d2 that perform uniaxial driving, the drive axes thereof being arranged in a straight line and parallel to the Y axis.

  The surface acoustic wave actuator 49a1 constituting the first surface acoustic wave actuator 49a is made of a material having piezoelectricity, and is separated from the surface acoustic wave substrate 44a1 fixed to the fixed substrate 45 and the upper surface of the surface acoustic wave substrate 44a1. The driving electrodes 42a1 and 42b1 formed in this manner, and a moving body 43a1 that is pressed with a predetermined pressure on a region between the driving electrodes 42a1 and 42b1 on the upper surface of the surface acoustic wave substrate 44a1 and frictionally coupled to the surface acoustic wave substrate 44a1. including. A plurality of minute protrusions are formed on the surface of the moving body 43a1 facing the surface acoustic wave substrate 44a1.

  The surface acoustic wave actuator 49a2 constituting the first surface acoustic wave actuator 49a is made of a material having piezoelectricity, and is separated from the surface acoustic wave substrate 44a2 fixed to the fixed substrate 45 and the upper surface of the surface acoustic wave substrate 44a2. The driving electrodes 42a2 and 42b2 formed in this manner, and a movable body 43a2 that is pressed with a predetermined pressure on a region between the driving electrodes 42a2 and 42b2 on the upper surface of the surface acoustic wave substrate 44a2 and frictionally coupled to the surface acoustic wave substrate 44a2. including. A plurality of minute protrusions are formed on the surface of the moving body 43a2 facing the surface acoustic wave substrate 44a2.

  A substantially inverted V-shaped elastic body 41a is bridged between the moving body 43a1 and the moving body 43a2.

  The surface acoustic wave actuator 49b1 constituting the second surface acoustic wave actuator 49b is made of a material having piezoelectricity, and is separated from the surface acoustic wave substrate 44b1 fixed to the fixed substrate 45 and the upper surface of the surface acoustic wave substrate 44b1. The driving electrodes 42c1 and 42d1 formed in this manner, and a moving body 43b1 that is pressed with a predetermined pressure on the area between the driving electrodes 42c1 and 42d1 on the upper surface of the surface acoustic wave substrate 44b1 and frictionally coupled to the surface acoustic wave substrate 44b1. including. A plurality of minute protrusions are formed on the surface of the moving body 43b1 facing the surface acoustic wave substrate 44b1.

  The surface acoustic wave actuator 49b2 constituting the second surface acoustic wave actuator 49b is made of a piezoelectric material, and is separated from the surface acoustic wave substrate 44b2 fixed to the fixed substrate 45 and the upper surface of the surface acoustic wave substrate 44b2. The driving electrodes 42c2 and 42d2 formed on the surface of the surface acoustic wave substrate 44b2, and a movable body 43b2 that is pressed with a predetermined pressure on a region between the driving electrodes 42c2 and 42d2 on the upper surface of the surface acoustic wave substrate 44b2 and frictionally coupled to the surface acoustic wave substrate 44b2. including. A plurality of minute protrusions are formed on the surface of the moving body 43b2 facing the surface acoustic wave substrate 44b2.

  A substantially inverted V-shaped elastic body 41b is bridged between the moving body 43b1 and the moving body 43b2.

  The surface acoustic wave actuator 49c1 constituting the third surface acoustic wave actuator 49c is made of a material having piezoelectricity, and is separated from the surface acoustic wave substrate 44c1 fixed to the fixed substrate 45 and the upper surface of the surface acoustic wave substrate 44c1. The driving electrodes 42e1 and 42f1 formed in this manner, and a moving body 43c1 that is pressed with a predetermined pressure to a region between the driving electrodes 42e1 and 42f1 on the upper surface of the surface acoustic wave substrate 44c1 and frictionally coupled to the surface acoustic wave substrate 44c1. including. A plurality of minute protrusions are formed on the surface of the moving body 43c1 facing the surface acoustic wave substrate 44c1.

  The surface acoustic wave actuator 49c2 constituting the third surface acoustic wave actuator 49c is made of a material having piezoelectricity, and is separated from the surface acoustic wave substrate 44c2 fixed to the fixed substrate 45 and the upper surface of the surface acoustic wave substrate 44c2. The driving electrodes 42e2 and 42f2 formed in this manner, and a moving body 43c2 that is pressed with a predetermined pressure on the upper surface of the surface acoustic wave substrate 44c2 between the driving electrodes 42e2 and 42f2 and frictionally coupled to the surface acoustic wave substrate 44c2. including. A plurality of minute protrusions are formed on the surface of the moving body 43c2 facing the surface acoustic wave substrate 44c2.

  A substantially inverted V-shaped elastic body 41c is stretched between the moving body 43c1 and the moving body 43c2.

  The surface acoustic wave actuator 49d1 constituting the fourth surface acoustic wave actuator 49d is made of a material having piezoelectricity, and is separated from the surface acoustic wave substrate 44d1 fixed to the fixed substrate 45 and the upper surface of the surface acoustic wave substrate 44d1. The driving electrodes 42g1 and 42h1 formed in this manner, and a movable body 43d1 that is pressed with a predetermined pressure to a region between the driving electrodes 42g1 and 42h1 on the upper surface of the surface acoustic wave substrate 44d1 and frictionally coupled to the surface acoustic wave substrate 44d1. including. A plurality of minute protrusions are formed on the surface of the moving body 43d1 facing the surface acoustic wave substrate 44d1.

  The surface acoustic wave actuator 49d2 constituting the fourth surface acoustic wave actuator 49d is made of a material having piezoelectricity, and is separated from the surface acoustic wave substrate 44d2 fixed to the fixed substrate 45 and the upper surface of the surface acoustic wave substrate 44d2. The driving electrodes 42g2 and 42h2 formed in this manner, and a moving body 43d2 that is pressed with a predetermined pressure to a region between the driving electrodes 42g2 and 42h2 on the upper surface of the surface acoustic wave substrate 44d2 and frictionally coupled to the surface acoustic wave substrate 44d2. including. A plurality of minute protrusions are formed on the surface of the moving body 43d2 facing the surface acoustic wave substrate 44d2.

  A substantially inverted V-shaped elastic body 41d is stretched between the moving body 43d1 and the moving body 43d2.

  The tops of the substantially inverted V-shaped elastic bodies 41a to 41d located at the center in the longitudinal direction are connected to the image sensor 40 via the elastic spring 50 (see FIG. 5). At this time, the elastic spring 50 that connects the elastic bodies 41 a and 41 c and the image sensor 40 has low Y-direction rigidity and high X-direction rigidity, and the elastic spring 50 that connects the elastic bodies 41 b and 41 d and the image sensor 40. Preferably has low rigidity in the X direction and high rigidity in the Y direction.

  Next, the operation principle of the first to fourth surface acoustic wave actuators 49a to 49d will be described. Since the operating principle of the first to fourth surface acoustic wave actuators 49a to 49d is the same except that the arrangement direction of the drive shaft is different, the first surface acoustic wave actuator 49a will be described. FIG. 5 is a side view showing the driving principle of the first surface acoustic wave actuator 49a.

  As described above, the first surface acoustic wave actuator 49a is configured by arranging the two surface acoustic wave actuators 49a1 and 49a2 that perform uniaxial driving in the X direction so that their driving directions are in a straight line.

  By applying a high frequency (several to several tens of MHz) to the drive electrodes 42a1 and 42b1 and / or the drive electrodes 42a2 and 42b2, the surface acoustic wave that propagates only near the surface of the surface acoustic wave substrate 44a1 and / or surface acoustic wave substrate 44a2. The moving body 43a1 and / or the moving body 43a2 to which the pressure is applied can be moved in the X direction by using a minute vibration of several nm obtained by the high frequency. The mobile body 43a1 and the mobile body 43a2 can be independently driven by appropriately setting the high frequency applied to the drive electrodes 42a1, 42b1, 42a2, and 42b2 independently.

  Here, a substantially inverted V-shaped elastic body 41a is bridged between the moving body 43a1 and the moving body 43a2. Depending on the respective moving directions of the moving body 43a1 and the moving body 43a2, the elastic spring 50 fixed to the top of the substantially inverted V-shaped elastic body 41 can be moved in four different directions. This will be described below.

  As shown in FIG. 6A, when the moving body 43a1 and the moving body 43a2 are driven to the left along the directions of arrows 51a1 and 51a2, that is, in the X direction, they are coupled to each other as shown in FIG. 6B. The elastic body 41a moves in the direction of the arrow 52a, that is, leftward. As a result, the driven body (imaging element 40) connected to the elastic body 41a via the elastic spring 50 moves in the same left direction as the moving body 43a1 and the moving body 43a2 (first driving mode).

  On the other hand, as shown in FIG. 7A, when the moving body 43a1 and the moving body 43a2 are driven in the right direction opposite to that shown in FIG. 6A, the elasticity coupled thereto is shown in FIG. 7B. The body 41a moves to the right. Thereby, the driven body (imaging element 40) connected to the elastic body 41a via the elastic spring 50 moves to the right (second drive mode).

  As shown in FIG. 8A, the moving body 43a1 and the moving body 43a2 are driven closer to each other, that is, the moving body 43a1 is driven rightward along the X direction as indicated by an arrow 51a1, and the moving body 43a2 is moved. When driven to the left along the X direction as shown by the arrow 51a2, the substantially inverted V-shaped elastic body 41a coupled thereto receives a compressive force in the X direction as shown in FIG. The top part is elastically deformed so as to move upward as indicated by an arrow 52a. Thereby, the driven body (imaging element 40) connected to the elastic body 41a via the elastic spring 50 moves upward (third drive mode).

  On the contrary, as shown in FIG. 9A, the moving body 43a1 and the moving body 43a2 are driven away from each other, that is, the moving body 43a1 is driven leftward along the X direction as indicated by an arrow 51a1. When the moving body 43a2 is driven to the right along the X direction as indicated by the arrow 51a2, the substantially inverted V-shaped elastic body 41a coupled thereto is pulled in the X direction as shown in FIG. 9B. Under the force, the top part is elastically deformed so as to move downward as indicated by an arrow 52a. Thereby, the driven body (imaging element 40) connected to the elastic body 41a via the elastic spring 50 moves downward (fourth drive mode).

  Furthermore, the driven body (imaging element 40) can be moved simultaneously in the X direction and the Z direction by making the moving direction of the moving body 43a1 and the moving body 43a2 the same direction and making the moving speeds of the both different.

  As described above, the first surface acoustic wave actuator 49a includes the two surface acoustic wave actuators 49a1 and 49a2 that perform uniaxial driving and the elastic body 41a that connects them, so that the driving directions of the surface acoustic wave actuators 49a1 and 49a2 are achieved. The driven body can be driven in two directions, ie, the same X direction and a Z direction orthogonal thereto.

  The imaging device 40 is supported by first to fourth surface acoustic wave actuators 49a to 49d that perform the same operation as the first surface acoustic wave actuator 49a, and these actuators 49a to 49d are driven independently, whereby the imaging device 40 can be driven in an arbitrary direction of a three-axis direction obtained by adding the Z direction to the X direction and the Y direction.

  In the above embodiment, the image sensor 40 is driven in three axes, but the lens may be driven in three axes.

  According to this embodiment, for example, a small and thin camera module having an optical zoom function, an autofocus function, a camera shake correction function, or the like can be realized.

(Embodiment 3)
10A is a plan view of the camera module according to Embodiment 3 of the present invention, and FIG. 10B is a cross-sectional view taken along line 10B-10B in FIG. 10A. The camera module according to the third embodiment includes a lens 61 and an image sensor 60 disposed to face the lens 61. The lens 61 forms an image on the image sensor 60 by bending light from the subject. As shown in the figure, an XYZ three-dimensional orthogonal coordinate system is set in which the axis parallel to the optical axis of the lens 61 is the Z axis.

  Around the image sensor 60, first and second surface acoustic wave actuators 29a and 29b that perform uniaxial driving are disposed. The first surface acoustic wave actuator 29a is arranged so that its driving direction is parallel to the X axis, and the second surface acoustic wave actuator 29b is arranged so that its driving direction is parallel to the Y axis. The first and second surface acoustic wave actuators 29a and 29b drive the image sensor 60 in the XY plane. The basic configurations of the first and second surface acoustic wave actuators 29a and 29b that perform uniaxial driving are the same as those described in the first embodiment, and the same components as those in the first embodiment are denoted by the same reference numerals. A detailed description thereof will be omitted.

  The surface acoustic wave substrates 23 a and 23 b constituting the first and second surface acoustic wave actuators 29 a and 29 b are fixed on a fixed substrate 66.

  Reference numerals 70a and 70b denote pressurizing mechanisms that press the movable bodies 26a and 26b against the surfaces of the surface acoustic wave substrates 23a and 23b with a predetermined pressure.

  The moving body 26a is connected to the imaging element 60 via a Y-direction elastic spring 65a, and the moving body 26b is connected to the imaging element 60 via an X-direction elastic spring 65b. The Y-direction elastic spring 65a has low Y-direction rigidity and high X-direction rigidity. Accordingly, the rigidity between the moving body 26a and the image sensor 60 is low in the Y direction and high in the X direction. The X-direction elastic spring 65b has low rigidity in the X direction and high rigidity in the Y direction. Accordingly, the rigidity between the moving body 26b and the image sensor 60 is low in the X direction and high in the Y direction.

  As described in the first embodiment, the imaging element 60 is driven in the X direction and / or the Y direction by applying a high frequency (several to several tens of MHz) to the drive electrodes 22a and 22b and / or the drive electrodes 22c and 22d. can do. By appropriately controlling the high-frequency pattern applied to the drive electrodes 22a and 22b and / or the drive electrodes 22c and 22d, the two-dimensional position of the image sensor 60 in the X direction and the Y direction can be set to a desired position. it can. Thereby, for example, an optical zoom function and a camera shake correction function in the camera module can be realized.

  Since the moving bodies 26a and 26b and the image sensor 60 are connected via the Y-direction elastic spring 65a and the X-direction elastic spring 65b, the first and second actuators 29a and 29b are frictionally coupled to each other. Therefore, it is possible to freely drive the image sensor 60 in the XY directions without interfering with each other even though the position is maintained.

  Further, a surface acoustic wave actuator 49 a is disposed around the image sensor 60. The surface acoustic wave actuator 49a drives the lens 61 in the Z direction (optical axis direction). The basic configuration of the surface acoustic wave actuator 49a is the same as that of the first surface acoustic wave actuator 49a described in the second embodiment, and the same components as those in the second embodiment are denoted by the same reference numerals, and The detailed description of is omitted. The surface acoustic wave actuator 49a includes two surface acoustic wave actuators 49a1 and 49a2 that perform uniaxial driving, the drive axes thereof being arranged in a straight line and parallel to the Y axis.

  The surface acoustic wave substrates 44a1 and 44a2 constituting the first surface acoustic wave actuator 49a are fixed on a fixed substrate 66.

  Reference numerals 70c and 70d denote pressurizing mechanisms that press the moving bodies 43a1 and 43a2 against the surfaces of the surface acoustic wave substrates 44a1 and 44a2 with a predetermined pressure.

  Reference numeral 69 denotes a connecting means for connecting the lens 61 and the top portion located at the center in the longitudinal direction of the substantially inverted V-shaped elastic body 41a bridged between the moving body 43b1 and the moving body 43b2.

  As described in the second embodiment, the moving body 43a1 and the moving body 43a2 are moved in the Y direction by applying a high frequency (several to several tens of MHz) to the drive electrodes 42a1, 42b1, 42a2, and 42b2. The mobile body 43a1 and the mobile body 43a2 can be independently driven by appropriately setting the high-frequency pattern applied to the drive electrodes 42a1, 42b1, 42a2, and 42b2 independently. For example, by applying a high frequency to the drive electrodes 42a1 and 42b2, the moving body 43a1 and the moving body 43a2 are driven in a direction away from each other, and the elastic body 41a is deformed so that the dimension in the Z direction is reduced, whereby the lens 61 Can be moved along the Z direction (optical axis direction) in a direction approaching the image sensor 60. On the contrary, by applying a high frequency to the drive electrodes 42b1 and 42a2, the moving body 43a1 and the moving body 43a2 are driven in directions approaching each other, and the elastic body 41a is deformed so that its dimension in the Z direction increases. The lens 61 can be moved in the direction away from the image sensor 60 along the Z direction (optical axis direction). Thereby, for example, a zoom function and an autofocus function in a camera module can be realized.

  In the first to third embodiments, an actuator using a surface acoustic wave is used as a drive source. However, an actuator using a piezoelectric element can also be used, and in this case, the same effect as described above can be obtained.

  In the first to third embodiments, the case where the lens system is a single lens has been described. However, the lens system may include a plurality of lenses. In this case, one or more of the lenses can be driven.

  The field of use of the present invention is not particularly limited, but can be used for, for example, a camera module mounted on a portable information terminal or a mobile phone that is required to be reduced in size and thickness.

(A) is a top view of the camera module which concerns on Embodiment 1 of this invention, (B) is sectional drawing along the surface containing the optical axis of the lens system. It is a block diagram of the drive circuit which drives the drive electrode of the camera module which concerns on Embodiment 1 of this invention. It is a perspective view of the camera module carrying the three-dimensional drive device which concerns on Embodiment 2 of this invention. It is a top view of the camera module carrying the three-dimensional drive device which concerns on Embodiment 2 of this invention. It is a side view which shows the drive principle of the 1st surface acoustic wave actuator which comprises the three-dimensional drive device which concerns on Embodiment 2 of this invention. (A) And (B) is a side view which shows the principle of the 1st drive mode of the 1st surface acoustic wave actuator which comprises the three-dimensional drive device concerning Embodiment 2 of this invention. (A) And (B) is a side view which shows the principle of the 2nd drive mode of the 1st surface acoustic wave actuator which comprises the three-dimensional drive device concerning Embodiment 2 of this invention. (A) And (B) is a side view which shows the principle of the 3rd drive mode of the 1st surface acoustic wave actuator which comprises the three-dimensional drive device concerning Embodiment 2 of this invention. (A) And (B) is a side view which shows the principle of the 4th drive mode of the 1st surface acoustic wave actuator which comprises the three-dimensional drive device concerning Embodiment 2 of this invention. (A) is a top view of the camera module which concerns on Embodiment 3 of this invention, (B) is arrow sectional drawing in the 10B-10B line | wire of (A). It is the disassembled perspective view which showed an example of the optical system (anti-vibration optical system) provided with the conventional camera-shake correction function. (A) is a top view which shows schematic structure of the conventional surface acoustic wave motor, (B) is the side view. FIG. 13 is an enlarged view of a portion 13 in FIG.

Explanation of symbols

1 Lens 2a, 2b Magnet 3a, 3b Coil 10 Surface acoustic wave substrate 11a, 11b Drive electrode (IDT)
DESCRIPTION OF SYMBOLS 12 Moving body 14 Protrusion 15 Fixed board | substrate 20a 1st board | substrate 20b 2nd board | substrate 21 Image pick-up element 22a-22d Drive electrode 23a, 23b Surface acoustic wave board | substrate 24a Y direction elastic spring 24b X direction elastic spring 25a, 25b Bidirectional elastic spring 26a, 26b Moving body 27 Fixed point 28 Lens 29a, 29b Surface acoustic wave actuator 30 Drive electrode X1 drive means 31 Drive electrode X2 drive means 32 Drive electrode Y1 drive means 33 Drive electrode Y2 drive means 34 X-direction drive force calculation means 35 Y-direction drive force Calculation means 36 High frequency generation means 37 Imaging element position determination means 38 Imaging element position detection sensor 40 Imaging elements 41a to 41d Elastic bodies 42a to 42d Driving electrodes 43a to 43d Moving bodies 44a to 44d Surface acoustic wave substrate 45 Fixed substrates 49a to 49d Elasticity Surface wave actuators 49a1, 49a 2 surface acoustic wave actuators 49b1 and 49b2 surface acoustic wave actuators 49c1 and 49c2 surface acoustic wave actuators 49d1 and 49d2 surface acoustic wave actuator 60 imaging element 61 lens 65a X-direction elastic spring 65b Y-direction elastic spring 66 fixed substrate 69 coupling means 70a to 70d Pressurization mechanism

Claims (22)

A first drive source having a first direction as a drive direction;
A second drive source having a second direction orthogonal to the first direction as a drive direction;
A first elastic spring that transmits a driving force of the first driving source to a driven body;
A second elastic spring that transmits the driving force of the second driving source to the driven body;
The rigidity of the first elastic spring is large in the first direction and small in the second direction,
The driving device according to claim 1, wherein the rigidity of the second elastic spring is large in the second direction and small in the first direction. A first drive source having a first direction as a drive direction;
A second drive source having a second direction orthogonal to the first direction as a drive direction;
A first elastic spring that transmits a driving force of the first driving device to a driven body;
A second elastic spring for transmitting the driving force of the second driving device to the driven body;
A fixed substrate for holding the first drive source and the second drive source,
The driving device, wherein the driven body is connected to the fixed substrate via a third elastic spring. The rigidity of the first elastic spring is large in the first direction and small in the second direction,
The drive device according to claim 2, wherein the rigidity of the second elastic spring is large in the second direction and small in the first direction.   The drive device according to claim 2, wherein the rigidity of the third elastic spring in the first direction is the same as the rigidity in the second direction.   The drive device according to claim 1, wherein each of the first drive source and the second drive source includes an actuator using a surface acoustic wave.   The drive device according to claim 1, wherein each of the first drive source and the second drive source includes an actuator using a piezoelectric element. A pair of uniaxial drive sources arranged so that each drive direction is on the same straight line;
An elastic body spanned between each moving body of the pair of uniaxial drive sources;
A connecting means for connecting the elastic body and the driven body,
A driving apparatus for driving the driven body in a direction perpendicular to a driving direction of the uniaxial driving source.   Furthermore, the drive device of Claim 7 which drives the said to-be-driven body in the direction parallel to the drive direction of the said uniaxial drive source.   The driving apparatus according to claim 7, wherein the driven bodies are driven in a direction perpendicular to a driving direction of the uniaxial driving source by moving respective moving bodies of the pair of uniaxial driving sources in opposite directions.   9. The drive device according to claim 8, wherein the driven body is driven in a direction parallel to the drive direction of the uniaxial drive source by moving the movable bodies of the pair of uniaxial drive sources in the same direction.   The drive device according to claim 7, wherein the uniaxial drive source includes an actuator using a surface acoustic wave.   The drive device according to claim 7, wherein the uniaxial drive source includes an actuator using a piezoelectric element. The driving device according to claim 8 or 10, wherein the driving device of the pair of uniaxial driving sources is arranged so that driving directions thereof are orthogonal to each other.
A three-dimensional drive device for driving the driven bodies in three axial directions orthogonal to each other.   The three-dimensional drive device according to claim 13, wherein the uniaxial drive source includes an actuator using a surface acoustic wave.   The three-dimensional drive device according to claim 13, wherein the uniaxial drive source includes an actuator using a piezoelectric element. A lens system comprising at least one lens;
An image sensor;
A driving device that drives at least one lens constituting the lens system or the imaging element in a direction perpendicular to the optical axis of the lens system;
A camera module having a shape in which at least two surfaces included in the lens system bend light;
A camera module, wherein the driving device is the driving device according to claim 1. A lens system comprising at least one lens;
An image sensor;
A driving device that drives at least one lens constituting the lens system or the image sensor in a direction parallel to at least the optical axis of the lens system;
A camera module having a shape in which at least two surfaces included in the lens system bend light;
The camera module according to any one of claims 7 to 12, wherein the drive device is arranged in a direction perpendicular to the drive direction of the uniaxial drive source in parallel with the optical axis.   The camera module according to claim 16 or 17, wherein the driving device drives the lens.   The camera module according to claim 16 or 17, wherein the driving device drives the imaging device. A lens system comprising at least one lens;
An image sensor;
A three-dimensional drive device that drives at least one lens constituting the lens system or the imaging device in a direction perpendicular to the optical axis of the lens system and a direction parallel to the optical axis;
A camera module having a shape in which at least two surfaces included in the lens system bend light;
The camera module which is the three-dimensional drive device in any one of Claims 13-15 in which the said three-dimensional drive device.   The camera module according to claim 20, wherein the three-dimensional driving device drives the lens.   The camera module according to claim 20, wherein the three-dimensional drive device drives the image sensor.

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