JP2008199755A - Drive device, lens unit, and optical device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To achieve a size reduction of a drive device. <P>SOLUTION: The drive device is provided with a holder 4, which has a tubular guide part 4a, and a lens barrel 2 stored inside the guide part 4a. The outer peripheral face of the lens barrel 2 is fitted to the inner peripheral face of the guide part 4a. The lens barrel 2 is rotatably supported in the guide part 4a. The lens barrel 2 is connected with a piezoelectric element 3 that expands/contracts when a voltage is applied and transmits a drive force, generated by expansion/contraction, to the lens barrel 2. The lens barrel 2 is rotated by the drive force from the piezoelectric element 3. The rotational movement of the lens barrel 2 is converted into linear movement so that the lens barrel 2 is displaced in a rotation-axis direction. The piezoelectric element 3 is installed so as to expand/contract in a tangential direction of the lens barrel. Therefore, it is possible to reduce the height of the whole drive device. Consequently, it achieves a size reduction of the device. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a driving apparatus including a piezoelectric element mounted on a precision instrument, an optical instrument, or the like.

  An imaging device such as a digital camera is equipped with a lens driving device for moving a movable part such as a focus lens in the optical axis direction. FIG. 9 shows a conventional example of a lens driving device mounted on the camera device disclosed in Patent Document 1.

  As shown in FIG. 9, the drive device 10 includes a lens barrel 11, a piezoelectric element 12, a holder 13, a guide shaft 14, a drive shaft 15, and a leaf spring 16 that functions as a friction member. A lens 17 is supported inside the lens barrel 11. The guide shaft 14 and the drive shaft 15 are arranged substantially symmetrical with respect to the optical axis with the lens barrel 11 in between. The axial directions of the guide shaft 14 and the drive shaft 15 are parallel to the optical axis of the lens barrel 11. The lens barrel 11 is connected to the guide shaft 14 and the drive shaft 15 so as to be movable in the axial direction. One end of the guide shaft 14 is fixed to the holder 13 and one end of the drive shaft 15 is fixed to the piezoelectric element 12. Further, the leaf spring 16 provided in the lens barrel 11 is in contact with the drive shaft 15. The elastic force of the leaf spring 16 generates a frictional force between the lens barrel 11 and the drive shaft 15, and the lens barrel 11 is supported by the drive shaft 15.

  When an axial external force greater than the frictional force generated between the lens barrel 11 and the drive shaft 15 is applied to the drive shaft 15, the lens barrel 11 can move in the axial direction with respect to the guide shaft 14 and the drive shaft 15. . When the external force in the axial direction is smaller than the frictional force generated between the lens barrel 11 and the drive shaft 15, the lens barrel 11 is supported by the guide shaft 14 and the drive shaft 15 and does not move. In order to apply an external force in the axial direction to the drive shaft 15, the piezoelectric element 12 is connected to one end of the drive shaft 15. The other end of the piezoelectric element 12 is fixed to the holder 13. As the piezoelectric element 12, an element that expands and contracts slightly when a voltage is applied is used.

In order to move the lens barrel 11 in the direction of arrow F shown in FIG. 9, a voltage is applied so that the piezoelectric element 12 is slowly stretched and then rapidly contracted. That is, when a voltage is applied so that the piezoelectric element 12 extends slowly, the drive shaft 15 and the lens barrel 11 supported by the drive shaft 15 move in the F direction by a distance that the piezoelectric element 12 is deformed. Further, when a voltage is applied so as to rapidly contract the piezoelectric element 12, the drive shaft 15 moves in the direction of arrow N by the distance that the piezoelectric element 12 contracts. At this time, since the inertial force of the lens barrel 11 is larger than the frictional force between the drive shaft 15 and the lens barrel 11, the lens barrel 11 remains in its original position, and only the drive shaft 15 moves in the direction of arrow N. That is, the lens barrel 11 does not move. The lens barrel 11 can be driven in a predetermined direction by repeating such an operation as one step.
Japanese Patent Laid-Open No. 4-69070 (published March 4, 1992)

  In recent years, it has become common to mount a digital camera on a mobile phone, and with the trend toward thinner mobile phones, there is a demand for thinner lens driving devices. Large elements that determine the height of the above-described conventional driving device include the amount of movement of the lens barrel, the thickness of the piezoelectric element, and the like. Here, since the amount of movement of the lens barrel is determined by the optical performance of the lens, it is excluded from the problem for realizing thinning of the apparatus.

  Therefore, it is conceivable to reduce the thickness of the piezoelectric element in order to reduce the thickness of the lens driving device, but the amount of deformation of the piezoelectric element per applied voltage is reduced. For this reason, the driving force applied to the drive shaft from the piezoelectric element is reduced, the moving distance of the lens barrel in one step as described above is reduced, and the drive time is extended. Also, if the leaf spring is weakened in proportion to the decrease in driving force, the frictional force for holding the lens barrel will be weakened, and the position of the lens barrel will easily change due to external vibration, impact, etc. Can happen.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to realize downsizing of a driving device without deteriorating driving characteristics by a piezoelectric element.

  In order to solve the above-described problem, the drive device according to the present invention is fitted to one of the guide member having the accommodating portion and the inner peripheral surface and the outer peripheral surface of the accommodating portion, and is rotatable to the accommodating portion. And a piezoelectric element connected to the driving member and extending and contracting in a tangential direction of the driving member. The driving member is fitted to the guide member as the piezoelectric element expands and contracts. It is characterized by being displaced in the direction of the rotation axis by rotating in the combined state.

  According to the above configuration, when a voltage is applied to the piezoelectric element connected to the driving member and the piezoelectric element is deformed, the driving force generated by the deformation of the piezoelectric element is transmitted to the driving member. At this time, since the piezoelectric element expands and contracts in the extending direction of the tangent line of the driving member, the driving member rotates by the driving force transmitted to the driving member. Further, the drive member is fitted to either the inner peripheral surface or the outer peripheral surface of the guide member, is supported so as to be able to rotate and move the guide member, and the rotational motion of the drive member is converted into a linear motion. It is configured to be displaced in the direction of the rotation axis.

As used herein, the term “piezoelectric element” is used interchangeably with the term “electrostrictive element” and is intended to be an element made of a material that is distorted and deformed against an electric field. . Further, the piezoelectric element, with respect to the applied electric field E, the amount of deformation may be an element having a linearity characteristic which is proportional to E, has a deformation amount approximating the curve proportional to E ² Characteristics It may be an element.

  Thus, the power for displacing the drive member is generated by the deformation of the piezoelectric element that expands and contracts in the tangential direction of the drive member. In general, a piezoelectric element provided in a driving device has the longest length in the expansion / contraction direction. In the drive device of the present invention, the piezoelectric element expands and contracts in a direction perpendicular to the displacement direction of the drive member, so that the height of the entire drive device can be kept low. As a result, downsizing of the apparatus can be realized. In addition, since the friction member and the drive shaft member mounted on the conventional drive device are unnecessary, the number of components mounted on the device can be reduced, and further, the process of managing the shaft accuracy when the device is assembled is unnecessary. Therefore, the manufacturing process can be shortened. As a result, the manufacturing cost can be reduced.

  In the drive device according to the present invention, a screw thread portion is formed in a spiral shape on one of the outer peripheral surface and the inner peripheral surface of the drive member, and the screw is formed on either the inner peripheral surface or the outer peripheral surface of the housing portion. Complementary thread grooves are formed in the ridges, and the drive member rotates and moves with the thread ridges fitted into the thread grooves as the piezoelectric element expands and contracts. It is preferable to be displaced.

  Either one of the outer peripheral surface of the drive member and the inner peripheral surface of the housing portion is spirally formed with a screw thread, and either the inner peripheral surface or the outer peripheral surface of the guide member is complementary to the screw thread. By forming a simple screw groove, the drive member can be appropriately supported by the guide member by the frictional force between the screw thread and the screw groove. In addition, the rotation angle of the drive member and the amount of displacement in the direction of the rotation axis can be made constant, and the amount of displacement of the drive member can be accurately controlled by the pitch of the helical line of the thread. For this reason, it is suitable for the structure which converts the rotational motion of a drive member into a linear motion.

  Furthermore, the frictional force between the screw thread part and the screw groove part can be adjusted by appropriately changing the shapes of the screw thread part and the screw groove part. When the driving force transmitted from the piezoelectric element is larger than the frictional force between the driving member and the guide member, the driving member is displaced. Therefore, by adjusting the frictional force between the driving member and the guide member, the driving force by the piezoelectric element necessary for displacing the driving member can be adjusted. That is, for example, if the frictional force is reduced, the driving member can be displaced by a smaller driving force, but there is also a problem that the position of the driving member easily changes due to external vibration, impact, etc. The shapes of the thread portion and the thread groove portion may be determined in consideration of these influences.

  In the driving device according to the present invention, the piezoelectric element extends and contracts with respect to a plane perpendicular to the rotation axis of the driving member so as to expand and contract in a state inclined at the same angle as the lead angle of the thread portion. It is preferable that it is connected.

  With respect to a plane perpendicular to the rotation axis of the drive member, the piezoelectric element is connected to the lead angle of the spiral thread portion, that is, the rotation axis of the drive member passing through the screw winding line and one point above it. Since it expands and contracts in a state where it is inclined at the same angle as the angle formed by the perpendicular plane, the driving force by the piezoelectric element can be transmitted to the driving member more efficiently.

  The drive device according to the present invention preferably further includes a weight member at an end of the piezoelectric element that is not connected to the drive member.

  Since the weight member is provided at the end of the piezoelectric element that is not connected to the driving member, the driving force due to expansion and contraction of the piezoelectric element can be more efficiently generated by the inertial force generated in the weight member.

  The drive device according to the present invention preferably further includes an elastic member that presses the drive member in the rotation axis direction.

  Thereby, the frictional force between the drive member and the guide member can be adjusted more easily.

  In the drive device according to the present invention, a guide pin is formed on one of the outer peripheral surface of the drive member and the inner peripheral surface of the housing portion, and a guide groove portion that fits the guide pin is formed on the other. The drive member is preferably displaced in the direction of the rotation axis by causing the guide pin to fit into the guide groove and rotating as the piezoelectric element expands and contracts.

  A guide pin is formed on one of the outer peripheral surface of the drive member and the inner peripheral surface of the housing portion, and a guide groove portion into which the guide pin can be fitted is formed on the other side. The drive member can be appropriately supported inside the guide member by the frictional force therebetween.

  In the drive device according to the present invention, a guide pin is formed on one of the inner peripheral surface of the drive member and the outer peripheral surface of the housing portion, and a guide groove portion that fits the guide pin is formed on the other. The drive member is preferably displaced in the direction of the rotation axis by causing the guide pin to fit into the guide groove and rotating as the piezoelectric element expands and contracts.

  A guide pin is formed on one of the inner peripheral surface of the drive member and the outer peripheral surface of the housing portion, and a guide groove portion on which the guide pin can be fitted is formed on the other side. The drive member can be appropriately supported inside the guide member by the frictional force therebetween.

  By adopting the drive device according to the present invention, it is possible to provide a lens unit, an optical device, and an information processing device that have the effect of reducing the thickness and reducing the cost, similarly to the drive device.

  The information processing apparatus includes an imaging device equipped with the optical device, a mobile phone, a personal computer, a portable information terminal, a game device, and the like equipped with the imaging device.

  Since the drive device according to the present invention includes the piezoelectric element that expands and contracts in the tangential direction of the drive member as described above, the piezoelectric element is arranged in a direction perpendicular to the optical axis of the drive member, and the entire drive device Can be kept low. In addition, since the shaft member, friction coupling member, and the like provided in the conventional drive device are no longer necessary, the number of components can be reduced, and a process for managing the shaft accuracy when the device is assembled is not necessary. Therefore, the manufacturing process can be shortened. As a result, the manufacturing cost can be reduced.

  The first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a perspective view of a drive device according to the present invention, FIG. 2 is a sectional view of the drive device according to the present invention, and FIGS. 3 and 4 are top views of the drive device according to the present invention. is there.

  As shown in FIG. 1, the drive device 1 includes a lens barrel (drive member) 2, a piezoelectric element 3, a holder 4, and a weight (weight member) 5. A lens 6 (FIG. 2) is supported inside the lens barrel 2. The holder 4 has a cylindrical guide part (guide member) 4a, and the lens barrel 2 is accommodated in the guide part 4a (accommodating part). One end of the piezoelectric element 3 is connected to the lens barrel 2, and a weight 5 is attached to the other end. The piezoelectric element 3 expands and contracts slightly when a voltage is applied, and transmits the driving force generated by the expansion and contraction to the lens barrel 2.

  Further, as shown in FIG. 2, a screw thread portion 2 a is formed in a spiral shape on the outer peripheral surface of the lens barrel 2, and a screw groove portion 4 b is formed on the inner peripheral surface of the guide portion 4 a of the holder 4. . The screw thread portion 2a and the screw groove portion 4b have complementary shapes, and the outer peripheral surface of the lens barrel 2 is fitted to the inner peripheral surface of the guide portion 4a. Thus, the lens barrel 2 is supported in the guide portion 4a by the frictional force generated between the screw thread portion 2a and the screw groove portion 4b having complementary shapes.

  Here, with reference to FIG. 3 and FIG. 4, the drive mechanism of the drive device 1 is demonstrated. As shown in FIGS. 3 and 4, the piezoelectric element 3 is provided so as to expand and contract in the tangential direction of the lens barrel 2. Since the piezoelectric element 3 has the longest length in the expansion / contraction direction, by providing the piezoelectric element 3 so as to expand / contract in the tangential direction of the lens barrel 2, the overall height of the driving device 1 can be kept low. In order to move the lens barrel 2 in the direction of the arrow F shown in FIG. 1, a voltage is applied to the piezoelectric element 3 so that the piezoelectric element 3 expands slowly and then contracts rapidly. When the piezoelectric element 3 extends slowly, a downward driving force in FIG. 3 is applied to the weight 5, and the weight 5 moves downward in FIG. 3. At this time, since the driving force applied to the weight 5 is smaller than the frictional force generated between the screw thread portion 2a and the screw groove portion 4b, the lens barrel 2 does not move. Next, when the piezoelectric element 3 rapidly contracts, a driving force in a direction approaching the weight 5 is applied to the lens barrel 2 by an inertial force acting on the weight 5.

  That is, since the driving force in the tangential direction of the lens barrel 2 is applied to the lens barrel 2, and this driving force is larger than the frictional force generated between the screw thread portion 2a and the screw groove portion 4b, the lens barrel 2 is connected. Together with the piezoelectric element 3 and the weight 5 that are in rotation, it rotates around the screw axis. That is, the lens barrel 2 rotates in the direction of arrow A shown in FIG. As a result, the piezoelectric element 3 and the weight 5 move to the positions shown in FIG. 3 is converted into a linear motion in the direction of the rotation axis, and the lens barrel 2 is displaced in the direction of the arrow F shown in FIG. By repeating this series of movements as one step, the lens barrel 2 is driven with a predetermined amount of displacement.

  On the other hand, when the lens barrel 2 is screwed, that is, in order to move in the direction of the arrow N shown in FIG. 1, a voltage is applied to the piezoelectric element 3 so that the piezoelectric element 3 expands rapidly and then contracts slowly.

  Here, the rotation angle of the lens barrel 2 and the amount of displacement in the direction of the rotation axis are kept constant by the screw thread portion 2a and the screw groove portion 4b. Further, the amount of displacement of the lens barrel 2 can be accurately controlled by the pitch of the helical line of the spiral thread portion 2a. Moreover, the frictional force generated between the thread part 2a and the thread groove part 4b can be adjusted by appropriately changing the shapes of the thread part 2a and the thread groove part 4b. When the driving force transmitted from the piezoelectric element 3 is larger than the frictional force generated between the screw thread portion 2a and the screw groove portion 4b, the lens barrel 2 is displaced, and therefore, between the screw thread portion 2a and the screw groove portion 4b. By adjusting the frictional force generated in the lens, the driving force by the piezoelectric element 3 necessary for displacing the lens barrel 2 can be adjusted.

  For example, when the frictional force generated between the screw thread portion 2a and the screw groove portion 4b is reduced, the driving member can be displaced by a smaller driving force. However, if the frictional force generated between the screw thread portion 2a and the screw groove portion 4b is too small, there is a problem that the position of the drive member easily changes due to external vibration, impact, etc. The shape of the thread part 2a and the thread groove part 4b is determined in consideration of the influence.

  Further, as shown in FIG. 5, the piezoelectric element 3 is expanded and contracted with respect to a plane perpendicular to the rotation axis of the lens barrel 2 while being inclined at the same angle as the lead angle of the spiral thread portion 2a. The lens barrel 2 may be connected. FIG. 5 is a side view schematically showing a coupling state of the piezoelectric element 3 to the lens barrel 2 in one embodiment. Here, the lead angle of the threaded portion 2a is intended to be an angle α formed by the helical line 2a of the threaded portion and a plane X passing through one point on the threaded portion 2a and perpendicular to the rotation axis Y of the lens barrel 2. is doing. The piezoelectric element 3 is connected to the lens barrel 2 so as to expand and contract with respect to a plane X ′ perpendicular to the rotation axis Y of the lens barrel 2 while being inclined at the same angle α ′ as the lead angle α. As a result, the driving force by the piezoelectric element 3 can be transmitted to the lens barrel 2 more efficiently, and the time required to drive the lens barrel 2 by efficient driving can be shortened.

  Further, as shown in FIG. 6, a recess is formed on the outer periphery of the cylindrical portion where the lens 6 is supported in the lens barrel 2 so as to accommodate the cylindrical guide portion 4 a. The inner peripheral surface and the outer peripheral surface of the guide part 4a may be configured to fit. FIG. 6 is a cross-sectional view showing a second embodiment of the driving apparatus of the present invention. As shown in FIG. 6, the screw thread portion 2a spirally formed on the inner peripheral surface of the lens barrel 2 and the screw groove portion 4b spirally formed on the outer peripheral surface of the guide portion 4a are complementary to each other. The lens barrel 2 may be supported by the guide member 4a by fitting the inner peripheral surface of the lens barrel 2 to the outer peripheral surface of the guide portion 4a.

  When the drive device 1 as described above is fixed to the image sensor, the drive device can be used as an autofocus actuator of a camera device that extends and screws the lens 6 with respect to the image sensor.

  Another embodiment of the present invention is shown in FIGS. FIG. 7 is a perspective view showing a third embodiment of the drive device of the present invention, and FIG. 8 is a cross-sectional view showing a fourth embodiment of the drive device of the present invention. As shown in FIG. 7, the drive device 7 includes a lens barrel 2, a piezoelectric element 3, a holder 4, and a weight 5, similarly to the drive device 1 of the first embodiment. The holder 4 has a cylindrical guide part 4a, and the lens barrel 2 is accommodated inside the guide part 4a. One end of the piezoelectric element 3 is connected to the lens barrel 2, and a weight 5 is attached to the other end. The piezoelectric element 3 is connected to the lens barrel 2 so as to expand and contract in the tangential direction of the lens barrel 2.

  In the driving device 7 in the third embodiment, the lens barrel 2 is driven by a cam mechanism. That is, a guide pin 2 b is provided on the outer peripheral surface of the lens barrel 2, and a guide groove portion 4 c is formed on the inner peripheral surface of the guide portion 4 a of the holder 4. The guide pin 2b is fitted into the guide groove portion 4c, and the lens barrel 2 is supported in the guide portion 4a by a frictional force generated between the guide pin 2b and the guide groove portion 4c. On the other hand, the guide groove part 4c may be formed in the outer peripheral surface of the lens-barrel 2, and the guide pin 2b may be attached to the inner peripheral surface of the guide part 4a.

  Also in the driving device 7 of the third embodiment, the lens barrel 2 is driven by the driving force from the piezoelectric element 3 as in the driving device 1 of the first embodiment. In this case, the rotation angle of the lens barrel 2 and the amount of displacement in the direction of the axis of rotation are kept constant by the guide pin 2b and the guide groove 4c, and the amount of displacement of the lens barrel 2 is accurately controlled by the formation state of the guide groove 4c. be able to.

  In addition, in the driving device 7 shown in FIG. 7, similarly to the configuration shown in FIG. 6, there is a recess that accommodates the cylindrical guide portion 4 a on the outer periphery of the cylindrical portion where the lens is supported in the lens barrel 2. It is formed and the structure in which the inner peripheral surface of the lens-barrel 2 and the outer peripheral surface of the guide part 4a fit may be sufficient. That is, the lens barrel 2 is supported by the guide member 4a by fitting the guide pin 2b formed on the inner peripheral surface of the lens barrel 2 and the guide groove portion 4c formed on the outer peripheral surface of the guide portion 4a. May be. Moreover, the guide groove part 4c may be formed in the inner peripheral surface of the lens-barrel 2, and the guide pin 2b may be formed in the outer peripheral surface of the guide part 4a.

  Further, as in the driving device 8 shown in FIG. 8, in order to assist the frictional force generated between the screw thread portion 2a and the screw groove portion 4b, the spring 9 is in contact with the bottom surface of the lens barrel 2 in the guide portion 4a. May be provided. Thereby, the displacement of the lens barrel 2 due to external vibration, impact, or the like can be prevented. Similarly, in the driving device 7 shown in FIG. 7, the same effect can be obtained by providing the spring 9 so as to be in contact with the bottom surface of the lens barrel 2 in the guide portion 4a.

(Other configurations)
The present invention can also be expressed as follows.

(First configuration)
An electrostrictive element, a cylindrical guide member formed with a screw, and a moving body formed with a screw to be screwed with the electrostrictive element, the guide member and the moving body are screwed so as to be rotatable, and the strain element is driven. The moving body is fixed to the moving body so that the direction is substantially tangential to the screw, the moving body is rotated by an impact force due to expansion and contraction of the electrostrictive element, and the moving object is extended or screwed in the screw shaft direction. The drive device characterized.

(Second configuration)
The drive device described in the first configuration is characterized in that the electrostrictive element is inclined in accordance with the threading angle of the screw.

(Third configuration)
The drive device according to any one of the first and second configurations, wherein a weight member is fixed to one end of the electrostrictive element.

(Fourth configuration)
The drive device according to any one of the first to third configurations, wherein the elastic member is pressed in the axial direction of the screw.

(Fifth configuration)
The driving device and lens unit according to any one of the first to fourth configurations, wherein the screw is formed in a lens unit barrel.

(Sixth configuration)
6. The driving device and the lens unit according to any one of the first to fifth configurations, wherein a cam mechanism is used instead of the screw.

(Seventh configuration)
An optical device equipped with the driving device or lens unit described in any of the first to sixth configurations, an imaging device equipped with the optical device, a mobile phone equipped with the imaging device, a personal computer, a mobile phone Information terminals and game machines.

  The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope shown in the claims, and embodiments obtained by appropriately combining technical means disclosed in different embodiments. Is also included in the technical scope of the present invention.

  Since the drive device of the present invention can contribute to the downsizing of the device, the lens unit driven by the drive device, the optical device including the lens unit, the imaging device including the optical device, and the imaging device are mounted. The present invention can be applied to devices that are required to be thin and small, such as mobile phones, personal computers, portable information terminals, and game devices.

1 is a perspective view showing a first embodiment of the present invention. It is sectional drawing which shows the 1st Embodiment of this invention. It is a top view which shows the 1st Embodiment of this invention. It is a top view which shows the 1st Embodiment of this invention. It is a side view which shows typically one form of the installation state of the piezoelectric element of this invention. It is sectional drawing which shows the 2nd Embodiment of this invention. It is a disassembled perspective view which shows the 3rd Embodiment of this invention. It is sectional drawing which shows the 4th Embodiment of this invention. It is sectional drawing which shows the conventional drive device.

Explanation of symbols

1 drive device 2 lens barrel (drive member)
2a Thread part 2b Guide pin 3 Piezoelectric element 4 Holder 4a Guide part (guide member)
4b Screw groove 4c Guide groove 5 Weight (weight member)
6 Lens 9 Spring (elastic member)

Claims (10)

A guide member having a receiving portion;
A drive member that is fitted to either the inner peripheral surface or the outer peripheral surface of the housing portion and is supported by the housing portion so as to be rotatable.
A piezoelectric element coupled to the drive member and extending and contracting in a tangential direction of the drive member;
The drive device is displaced in the direction of the rotation axis by rotating in a state of being fitted to the guide member as the piezoelectric element expands and contracts. A screw thread portion is formed in a spiral shape on one of the outer peripheral surface and the inner peripheral surface of the drive member, and a screw groove portion complementary to the screw thread portion on either the inner peripheral surface or the outer peripheral surface of the housing portion Is formed,
2. The drive member according to claim 1, wherein the drive member is displaced in a rotation axis direction by fitting the screw thread portion into the screw groove portion and rotating and moving as the piezoelectric element expands and contracts. Drive device.   The piezoelectric element is connected to the drive member so as to expand and contract in a state inclined with respect to a plane perpendicular to the rotation axis of the drive member at the same angle as the lead angle of the thread portion. The drive device according to claim 2.   The drive device according to claim 1, further comprising a weight member at an end portion of the piezoelectric element not connected to the drive member.   The drive device according to claim 1, further comprising an elastic member that presses the drive member in a rotation axis direction. A guide pin is formed on one of the outer peripheral surface of the drive member and the inner peripheral surface of the housing portion, and a guide groove portion that is fitted to the guide pin is formed on the other,
2. The drive according to claim 1, wherein the drive member is displaced in a rotation axis direction by fitting the guide pin into the guide groove portion and rotationally moving as the piezoelectric element expands and contracts. apparatus. A guide pin is formed on one of the inner peripheral surface of the drive member and the outer peripheral surface of the accommodating portion, and a guide groove portion that is fitted to the guide pin is formed on the other,
2. The drive according to claim 1, wherein the drive member is displaced in a rotation axis direction by fitting the guide pin into the guide groove portion and rotationally moving as the piezoelectric element expands and contracts. apparatus. The drive device according to any one of claims 1 to 7,
A lens unit comprising: a lens supported in the driving member.   An optical device, wherein the lens unit according to claim 8 is mounted.   An information processing apparatus comprising the optical device according to claim 9.

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