JP2007292864A - Lens drive device and photographic apparatus using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve transmission efficiency of a lens drive mechanism and to make the mechanism compact. <P>SOLUTION: A lens frame 25 is supported so as to be freely movable in the direction of an optical axis and is pressed in one direction of the direction of the optical axis by a coil spring 24. A moving member 21 has a struck part 47, brought into contact with the struck part 46 of the lens frame 25 from one direction, supported so as to be freely movable in the direction of the optical axis, and is pressed by a tensile spring 22, in a direction where it is brought into contact with the lens frame 25. The moving member 21 has a wire receiving member 42. An SMA wire 20 is fixed to a fixed lens barrel 15 at both its ends, and an acting part 39 is hooked around a wire receiving member 42 so that a projection is oriented in the direction of a curved shape oriented in the one direction. By the displacement of the acting part 39 in the direction of the optical axis, resulting from a change from a curved shape to an almost straight shape by its shortening due to the supply of power, the lens frame 25 is moved in the other direction. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a lens driving device that drives a part of lenses or lens groups constituting an optical system using a shape memory alloy (SMA) wire and a photographing device using the lens driving device.

  The SMA mechanism includes an SMA wire and an energization control unit that controls energization of the SMA wire. When an SMA wire is heated to a temperature higher than its transition temperature by energization, it changes to a memorized shape, and when it is cooled to a temperature lower than its transition temperature, it reverses from the memorized shape to its original shape. To change.

A lens moving device that moves a lens using such a mechanism is conventionally known (Patent Document 1). In this device, the barrel holder that holds the lens barrel is rotated around the optical axis, thereby moving the lens holder in the optical axis direction while sequentially abutting the low, middle, and high cam steps formed on the mount plate for focusing. This is a lens moving device that is configured to rotate an actuator (lever) that rotates the barrel holder by expanding and contracting the SMA wire. Both ends of the SMA wire are fixed, and the center is hooked to one end of the actuator. The SMA wire undergoes a recovery displacement that shortens its length when self-heated by energization. When the recovery displacement is performed, the actuator rotates about the axis in conjunction with the contraction of the SMA wire, and the other end of the actuator rotates the barrel holder about the optical axis.
JP 2002-244015 A

  However, in the lens moving device, the barrel holder is supported so as to be rotatable about the optical axis and movable in the direction of the optical axis, and a rotational force is generated by the actuator by the recovery displacement of the SMA wire. Since this mechanism is converted into a linear force in the optical axis direction, the configuration is complicated, and since there are many configurations, there is a drawback that the drive transmission efficiency is lowered and the stopping accuracy of the lens is lowered. In addition, when the barrel holder is pushed by an external impact and rotates in any direction, the rotational force directly acts on the SMA wire via the actuator, which may deteriorate the performance of the SMA wire.

  The present invention has been made in consideration of the above-mentioned problems, and provides a lens driving device that is simple in configuration and that can maintain the performance of the SMA wire even from an external impact, and a photographing device using the lens driving device. The purpose is to do.

  In order to achieve the above object, in the lens driving device of the present invention, both ends are fixed to the fixed lens barrel, and are contracted by being heated by energization, and the original length when being cooled by de-energizing. A shape memory alloy wire that returns to the shape of the shape memory alloy wire so that the biasing means in the optical axis direction has a convex direction toward one side that biases the lens frame. A wire bearing member to which an action portion set between both ends is hooked; and the shape memory alloy wire holds and holds the lens frame with a predetermined length in a relaxed state when de-energized, Due to the displacement in the optical axis direction of the action portion when the length changes from a curved shape to a substantially linear shape due to the contraction of the length due to energization, the lens frame is resisted against the urging force of the urging means. It is intended to move towards

  When the shape memory alloy wire self-heats by energization, the shape memory alloy wire contracts and shortens from the length of the relaxed state (recovery displacement). When the energization is stopped, the length returns to the original length (the length in the relaxed state) by natural cooling (return displacement). The shape memory alloy wire is arranged so that both ends of this wire are fixed to the fixed barrel, the action part between both ends is hooked on the wire bearing member, and the convex is curved toward one side in the optical axis direction. When the length is reduced by energization, the lens frame can be moved toward the other side in the optical axis direction based on the displacement in the optical axis direction of the action portion when changing from a curved shape toward a substantially linear shape.

  By the way, when an external force is applied to the lens frame, the force is transmitted to the shape memory alloy wire, and the shape memory alloy wire may be damaged. When an external force is applied to the other side in the optical axis direction, the lens frame moves in a direction away from the wire receiving member, so there is no risk of damaging the shape memory alloy wire. When the contact is added, the lens frame moves in the direction in which the shape memory alloy wire bites into the wire receiving member, and there is a risk of damaging the shape memory alloy wire.

  Therefore, in another invention, a contact part provided on a part of the lens frame has a contact part abutting from one side and is supported so as to be movable in the optical axis direction; a lens frame and a movement member; A second urging means that is urged toward a direction in which the contacted part and the abutting part abut against each other and is set to a stronger urging force than the urging means; A wire bearing member on which the action portion of the shape memory alloy wire is hooked so as to be in a curved direction, and the shape memory alloy wire holds the moving member in a relaxed length when not energized. The lens frame resists the biasing of the biasing means through the moving member due to the displacement in the optical axis direction of the action part when the length is reduced from the curved shape to the substantially straight shape due to the contraction of the length by energization. It moves to the other side.

  According to this, when an external force is applied to the lens frame in one direction, the lens frame is moved by the force, and the moving member moves following the lens frame by the urging of the second urging means. The moving member moves in the direction in which the alloy wire bites into the wire receiving member. However, when the external force exceeds the urging force of the second urging means, the urging force of the second urging means is lost, and the excess amount is exceeded. Since the moving member is separated from the lens frame by the force of the force, there is no fear that the shape memory alloy wire is applied with a force greater than the urging force of the second urging means, and therefore the damage to the shape memory alloy wire can be suppressed. .

  When energization of the shape memory alloy wire is stopped, the shape memory alloy wire returns toward the relaxed length. At this time, if the shape memory alloy wire is simply hooked on the wire receiving member, the shape memory alloy wire may be detached from the wire receiving member. Therefore, it is preferable to provide the wire receiving member with a pressing member that prevents the shape memory alloy wire from falling off.

  In order to earn a moving stroke of the lens frame, it is necessary to increase the length of the shape memory alloy wire. However, if the length is simply increased, a large space is required to attach the shape memory alloy wire, and the apparatus itself becomes larger. Therefore, a first wire support member that supports one end of the shape memory alloy wire; a first intermediate member that supports the side opposite to the one end across the working portion; and a shape memory alloy that extends from the first intermediate member A second wire support member for supporting the other end of the wire; and a shape memory alloy wire between the first intermediate member and the second wire support member is bent and supported along the front contour of the fixed barrel It is preferable to provide a second intermediate member.

  Note that the lens driving device described above can be used for photographing devices such as a photographic camera, an electronic camera, a video camera, a mobile phone with a TV camera, and a projector.

  According to the present invention, the lens frame or the moving member is provided with the wire bearing member, and the convex is formed in a curved direction toward the one in which the biasing means in the optical axis direction biases the lens frame. Since the working portion of the memory alloy wire is hooked on the wire bearing member, the configuration is simple, and the length of the shape memory alloy wire is reduced by energization, so that the working portion is turned from a curved shape to a substantially straight shape. Due to the displacement in the direction of the optical axis when changed, the lens frame is moved toward the other side against the urging force of the urging means, so that the drive transmission efficiency is increased and the lens frame can be moved with high accuracy.

  In the invention provided with the moving member, when the external force is applied to the lens frame toward one of the urging directions of the urging means, and the external force is stronger than the second urging means, the moving means is the lens. Since the second urging means absorbs the force away from the frame and exceeding the urging force of the second urging means, the damage to the shape memory alloy wire can be suppressed.

  As shown in FIG. 1, the lens driving device 10 is a lens moving device for a small camera built in a mobile phone or the like, and moves the lens group 13 in the optical axis direction with respect to the light receiving surface 12 of the CCD 11. Perform focusing. The lens driving device 10 includes a CCD substrate 14, a fixed lens barrel 15, a first guide rod 16, a second guide rod 17, a pair of wire support members 18 and 19, a shape memory alloy wire (SMA wire) 20, and a moving member 21. , A tension spring 22, a spring receiving member 23, a coil spring 24, a lens frame 25, a cover 26, an energization control unit 28, and the like.

  The CCD 11 is positioned and fixed on the CCD substrate 14. The CCD substrate 14 is fixed behind the fixed barrel 15 so that the light receiving surface 12 is positioned on the optical axis. A cover 26 is inserted into the fixed barrel 15 from the subject side (front side), joined by an elastic claw, and fixed by screws 27. Between the fixed barrel 15 and the cover 26, the first guide rod 16, the second guide rod 17, a pair of wire support members 18, 19, an SMA wire 20, a moving member 21, a tension spring 22, a spring support The member 23, the coil spring 24, and the lens frame 25 are each inserted and attached from the front side.

  Both ends of the first and second guide rods 16 and 17 are fixed by the fixed barrel 15 and the cover 26, respectively, and are arranged in parallel to the optical axis at different positions. The lens frame 25 holds a lens group 13 that constitutes part or all of the optical system. A bearing 30 and a key protrusion 31 are integrally formed on the outer periphery of the lens frame 25. The bearing portion 30 includes a pair of front and rear receiving portions 32 and 33 provided at a predetermined distance in the optical axis direction. The first guide rod 16 is inserted into the front and rear receiving portions 32 and 33. Is done. The first guide rod 16 guides the movement of the lens frame 25 in the optical axis direction. The lens frame 25 moves inside a cylindrical portion 34 provided in the fixed barrel 15. The key protrusion 31 is formed long in the optical axis direction, and engages with a key groove 35 provided on the inner surface of the cylindrical portion 34 to stop the rotation of the lens frame 25. The cover 26 has an opening 29 for exposing the lens group 13.

  The spring receiving member 23 is made of an elastic material and is formed into a thin plate shape. One end 36 enters between the pair of front and rear receiving portions 32, 33 and includes the other end 37 except for the one end 36. Is fixed to the fixed lens barrel 15 and is arranged so that the longitudinal direction is along the direction perpendicular to the optical axis. As shown in FIG. 2, the one end 36 is formed with a hole 38 into which the first guide rod 16 enters with play. The coil spring 24 is inserted between one end 36 of the spring receiving member 23 and the front receiving portion 32 on the subject side and around the first guide rod 16, and the lens frame 25 faces the subject side with respect to the spring receiving member 23. Energize. In this manner, the one end 36 of the spring receiving member 23 is inserted between the front and rear receiving portions 32 and 33 to support the one end 24a of the coil spring 24, and the other end 24b of the coil spring 24 biases the lens frame 25. Therefore, space saving can be achieved as compared with a configuration in which the coil spring is disposed outside the bearing portion and one end of the coil spring is supported by another support member.

  The moving member 21 is integrally formed with a bearing portion 40, a key protrusion 41, and a wire receiving member 42. The second guide rod 17 is inserted into the bearing portion 40, and the second guide rod 17 guides the movement of the moving member 21 in the optical axis direction. The key protrusion 41 engages with the key groove 43 provided in the fixed barrel 15 to stop the rotation of the moving member 21. A spring hook portion 44 is formed on the moving member 21, and a tension spring 22 is hung between the spring hook portion 44 and a spring hook portion 45 provided on the front receiving portion 32. The tension spring 22 biases the moving member 21 in a direction approaching the lens frame 25. The position of the moving member 21 in the optical axis direction is usually determined by the contact portion 47 provided in a part of the moving member 21 abutting the contact portion 46 provided in a part of the lens frame 25. It is done. As the tension spring 22, a spring having a larger urging force than the coil spring 24 is used.

  The wire receiving member 42 has a pulley shape having a groove 50 on which the action portion 39 of the SMA wire 20 is hung. Both ends of the SMA wire 20 are fixed to a pair of wire support members 18, 19, and the pair of wire support members 18, 19 are fixed to the fixed barrel 15 apart in the vertical direction. Specifically, as shown in FIG. 3, the action portion 39 of the SMA wire 20 directs the moving member 21 toward the image plane when the recovery displacement is performed, that is, the direction in which the coil spring 24 biases the lens frame 25. It is hung on the groove 50 so as to be biased in the opposite direction.

  The SMA wire 20 has a fiber shape made of, for example, a shape memory alloy such as a Ti—Ni system or a Cu—Al—Zn system. The SMA wire 20 is subjected to processing for storing a specific shape for the material in advance. As a result, when the SMA wire 20 self-heats due to energization, the SMA wire 20 contracts to a previously stored contraction length (recovery displacement). When the energization is stopped, the original length (relaxed length) is restored (return displacement) by natural cooling.

  A pressing plate 51 is attached to the wire receiving member 42 so that the SMA wire 20 does not fall out of the groove 50 when the SMA wire 20 is returned and displaced. The pressing plate 51 is provided so as to protrude from the moving member 21, and has a notch portion 55 in which a part of a pair of flanges 53, 54 on both sides of the wire receiving member 42 sandwiching the groove 50 is cut out. 56. Providing the presser plate 51 in this way is convenient because it can be performed without worrying about the SMA wire 20 falling off during assembly. In addition, as long as it is a member which prevents the SMA wire 20 from dropping from the wire receiving member 42, not only the pressing plate 51 but any known one can be adopted.

  The energization control unit 28 energizes both ends of the SMA wire 20 via the pair of wire support members 18 and 19. The pair of wire support members 18 and 19 are made of a conductive material, and the fixed barrel 15 is made of an insulating material.

  When the SMA wire 20 reaches a certain temperature, the SMA wire 20 has a first natural temperature (recovery start point) that starts a recovery displacement. Thereafter, when the SMA wire 20 reaches a second natural temperature (saturation point), the recovery displacement further changes. Disappear. This state is the contracted length contracted in the length direction. Further, since the temperature of the SMA wire 20 depends on the amount of heat radiation (determined by the amount of heat generated by itself and the ambient temperature), the temperature rises faster as the amount of current increases, and thus the recovery speed also increases. On the other hand, since the return speed is a heat dissipation time until the temperature of the SMA wire 20 becomes equal to the ambient temperature, the return speed is substantially constant if the ambient temperature is constant.

  The energization of the energization control unit 28 includes a constant current drive method. In this constant current driving method, a constant current is passed through the SMA wire 20. The SMA wire 20 begins to recover when the current starts to flow, and when the current is saturated for a certain period of time, that is, when the current continues to flow, the amount of displacement does not change. Return to length. Therefore, in this method, the lens frame 25 can be moved only to two positions, that is, the initial position when the power is not supplied and the lens position when the recovery displacement is completed after the power is supplied. Therefore, the lens frame 25 can be moved to an arbitrary position between the two positions by using the pulse current driving method.

  The pulse current driving method is an energization method in which the ratio of the energization (on) time t to the period T (= 1 / f) of the frequency f, that is, the DUTY ratio is changed. In this method, the energization control unit 28 is provided with a pulse transmitter and a pulse width modulation circuit. Within the energization time, the SMA wire 20 is heated to start recovery displacement, and during the non-energization (off) time, it is naturally cooled to stop the recovery displacement and start the return displacement. However, depending on the value of the DUTY ratio, the SMA wire 20 is completely recovered Before the displacement, the energization time of the next cycle comes and the recovery displacement starts, so that the SMA wire 20 can be maintained at a desired length.

  Utilizing this, heating is controlled by changing the DUTY ratio of the modulation current to change the average value of the current. Specifically, the energization control unit 28 causes the square wave pulse width modulation current (PWM) to flow through the SMA wire 20. Thus, by changing the average value of the PWM current, the heating of the SMA wire 20 can be controlled, and the length of the SMA wire 20 can also be controlled. For example, the control unit of the camera guides the moving amount of the lens group 13 according to the subject distance obtained at that time by a distance measuring mechanism provided in the camera or the like, and the average value of the PWM current corresponding to the moving amount is previously stored in a ROM or the like. Refer to the table stored in The result is sent to the energization control unit 28, and the energization control unit 28 generates a square wave pulse width modulation current based on the result, and energizes the SMA wire 20.

  Since the energization from the energization controller 28 is stopped when the camera is in the initial state, the SMA wire 20 has a predetermined length of relaxation as shown in FIG. On the other hand, the lens frame 25 is biased toward one side by the bias of the coil spring 24, and the moving member 21 is biased in a direction to follow the lens frame 25 by the bias of the tension spring 22. On the other hand, the SMA wire 20 having a relaxed length stretches and holds the moving member 21 via the wire receiving member 42. For this reason, the lens frame 25 is stopped at a position where the abutted portion 46 abuts against the abutting portion 47 by the urging of the tension coil spring 24. The position of the lens frame 25 is an initial position closest to the subject side. At this time, the rear receiving portion 33 is in a state where a gap is generated between the rear receiving portion 33 and the one end 36 of the spring receiving member 23.

  When the SMA wire 20 is energized from the energization control unit 28, the SMA wire 20 self-heats, and when it reaches a predetermined temperature or more, a recovery displacement that contracts to a prestored contraction length is started. When the SMA wire 20 is contracted toward the contraction length, both ends of the SMA wire 20 are fixed. Therefore, as shown in FIGS. 4 and 5, the action portion of the SMA wire 20 is curved with the convex toward the subject. The moving member 21 is moved toward the image plane based on the amount of displacement along the optical axis direction of the action portion during this time. When the moving member 21 moves toward the imaging plane side, the urging force of the tension spring 22 is stronger than the coil spring 24, so that the lens frame 25 moves toward the imaging plane side by the urging force of the tension spring 22. Then, the lens frame 25 stops at a position where the hit portion 46 contacts the hit portion 47 of the moving member 21. As a result, the lens frame 25 moves from the sane position toward the other side. When the energization control unit 28 heats the SMA wire 20 to the second natural temperature, the contraction length is such that the SMA wire 20 is the shortest, and the position of the lens frame 25 at this time is closest to the image plane. It becomes the position.

  When the energization is stopped, the SMA wire 20 is softened by natural cooling, and a return displacement that returns to the original length is started. When the SMA wire 20 starts to return, the SMA wire 20 extends toward the relaxed length, so that the lens frame 25 moves toward the subject side by the urging force of the coil spring 24, and the moving member 21 is attached to the tension spring 22. It moves following the movement of the lens frame 25 by the force. When the return displacement is completed, the SMA wire 20 has a relaxed length. At this time, the SMA wire 20 is no longer stretched. For this reason, the moving member 21 is stretched and held by the SMA wire 20, and the contact portion 46 of the lens frame 25 abuts against the contact portion 47 of the moving member 21 by the urging of the tension spring 22, so that the lens frame 25 is in the initial position. Returned to

  By the way, the lens frame 25 may be subjected to an impact force from the outside. For example, when an external force in a direction in which the lens frame 25 is moved toward the other side, that is, an impact force in a direction opposite to the biasing direction of the coil spring 24 is applied to the lens frame 25, the coil spring 24 is compressed and the lens frame 25 is compressed. And the moving member 21 move together toward the other, and the wire receiving member 42 moves away from the SMA wire 20. As described above, since the SMA wire 20 is hooked so as to resist the biasing direction of the coil spring 24 to the lens frame 25, an impact force directed in the direction opposite to the biasing direction of the coil spring 24 is applied to the lens frame 25. Even if applied, the impact force is not applied to the SMA wire 20.

  On the contrary, when the impact force in the direction in which the lens frame 25 is moved toward one side, that is, the impact force in the biasing direction of the coil spring 24 is applied to the lens frame 25, the moving member 21 is moved by the biasing force of the tension spring 22. The SMA wire 20 is pulled by moving following the movement of the lens frame 25. When the impact force exceeds the urging force of the tension spring 22, the tension spring 22 is extended, and the lens frame 25 and the moving member are moved. 21 is released. For this reason, the SMA wire 20 is not subjected to a load greater than the urging force of the tension spring 22. Therefore, if the tension spring 22 is set to a larger biasing force than the coil spring 24, damage to the SMA wire 20 due to impact force can be suppressed.

  By the way, in order to earn the movement amount of the lens frame 25, it is necessary to increase the displacement amount in the optical axis direction in which the action portion of the SMA wire 20 is deformed from the curved shape to the linear shape. In this case, in order to secure the movement stroke of the lens frame 25 without sacrificing the downsizing of the lens driving device, it can be dealt with by increasing the total length of the SMA wire 20.

  6 and 7, the long SMA wire 60 can be used by bending the SMA wire 60 so as to surround the cylindrical portion 34 provided in the fixed lens barrel 15, and thereby the lens. A lens driving device 61 that can increase the movement stroke of the frame 25 is shown. In this embodiment, the same members as those described in FIGS. 1 to 5 are given the same reference numerals, and detailed description thereof is omitted here.

  The SMA wire 60 has a length that extends from the upper left to the lower right through the lower left of the cylindrical portion 34 when the cylindrical portion 34 is viewed from the front, and one end 62 is fixed to the first wire support member 63. The end 64 is fixed to the second wire support member 65. The second wire support member 65 is formed to extend longer than the first wire support member 63 in an L shape, and is attached to both ends of the SMA wire 60 via the first and second wire support members 63 and 65. Is energized from the energization controller. The SMA wire 60 is hooked by the first intermediate member 66 on the opposite side to the one end 62 with the acting portion 68 interposed between the acting portion 68 set near the one end 62 and the wire receiving member 42. After the wire support member 63 and the first intermediate member 66 are bent in a curved shape with one convex portion, the portion extending from the first intermediate member 66 is hooked on the second intermediate member 67 to the right of the cylindrical portion 34. It is bent downward. The other end 64 is located on an extension line bent by the second intermediate member 67. The first and second intermediate members 66 and 67 are attached to the fixed barrel 15.

  In the second embodiment described with reference to FIGS. 6 and 7, the SMA wire 60 having a length twice as long as the SMA wire 20 described in the first embodiment described with reference to FIGS. 1 to 5 is used. Therefore, when the contraction rate of the SMA wires 20 and 60 is the same, the contraction amount is approximately doubled, so that the moving stroke of the lens frame 25 can be made sufficiently large. In this example as well, the first and second intermediate members 66 and 67 are formed with grooves recessed one step, and the SMA wires 60 are respectively hooked in the grooves recessed one step, and the SMA wire 60 is in a relaxed state. The SMA wire 60 is prevented from falling off at the stepped portion rising from the groove so as not to drop out of the groove.

  In each of the above embodiments, the SMA wire 60 is hooked on the wire receiving member 42 provided on the moving member 21. However, the present invention is not limited thereto, and the moving member 21 and the tension spring 22 are omitted, and the wire receiving member 42 is omitted. May be attached to the lens frame 25 and the lens frame 25 may be moved directly by expansion and contraction of the SMA wires 20 and 60.

  In each of the above embodiments, the lens frame 25 is urged toward the subject by the coil spring 24, and the SMA wires 20 and 60 are hooked against the urge. The SMA wires 20 and 60 may be hooked so as to urge 25 toward the imaging plane side and resist the urging.

  The lens driving devices 10 and 61 described in the above embodiments are examples in which the lens frame 25 is moved at the time of focusing. However, the present invention is not limited to this, and the lens frame 25 may be moved at the time of zooming. In this case, the lens frame 25 may be moved based on the zoom direction and operation time obtained from the zoom operation unit.

  In each of the above embodiments, the lens driving devices 10 and 61 used in the camera are described. However, the present invention is not limited to this, and the present invention is not limited to this, and may be applied to an optical device such as an endoscope or a photographing device such as an electronic camera or projector. Needless to say, the present invention can be employed.

It is a disassembled perspective view which shows the outline of a lens drive device. It is explanatory drawing which looked at the principal part of the lens drive device demonstrated in FIG. 1 from the plane side, and has shown the state of the position (initial position) which the lens frame approached to the to-be-photographed object side most. It is explanatory drawing which looked at the principal part of the lens drive device demonstrated in FIG. 1 from the side surface side, and has shown the state of the position (initial position) which the lens frame approached to the to-be-photographed object side most. It is explanatory drawing which looked at the principal part of the lens drive device demonstrated in FIG. 1 from the plane side, and has shown the state of the position which energized the SMA wire and the lens frame approached the image plane side. It is explanatory drawing which looked at the principal part of the lens drive device demonstrated in FIG. 1 from the side surface side, and has shown the state of the position which energized the SMA wire and the lens frame approached the image plane side. It is a disassembled perspective view which shows the lens drive device using a long SMA wire so that the movement stroke of a lens frame may be earned. It is a perspective view which shows the SMA wire wrapping demonstrated in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10,61 Lens drive device 13 Lens group 18, 19, 63, 65 Wire support member 20, 60 SMA wire 21 Moving member 22 Tension spring 23 Spring receiving member 24 Coil spring 42 Wire receiving member

Claims (5)

A fixed lens barrel, a lens frame for holding a part or all of the lens group constituting the optical system, guide means for supporting the lens frame movably in the optical axis direction with respect to the fixed lens tube, and the lens An urging unit that urges the frame toward one of the optical axis directions, and the lens frame is directed toward the other against the urging of the urging unit with respect to the fixed barrel. In the lens driving device to be moved,
Both ends are fixed to the fixed lens barrel, and when heated by energization, the length becomes shorter than the predetermined length of the relaxed state, and the shape returns to the relaxed state when cooled by deenergizing. A memory alloy wire;
A wire bearing member that is provided on the lens frame and on which a working portion that is set between both ends of the shape memory alloy wire is hooked so that a convex direction is directed to the one side.
When the shape memory alloy wire is not energized, the lens frame is stretched and held with the length of the relaxed state, and when the length is reduced by energization, the shape memory alloy wire changes from the curved shape toward the substantially linear shape. The lens drive device according to claim 1, wherein the lens frame is moved toward the other side against the urging force of the urging means by displacement of the acting portion along the optical axis direction. A fixed lens barrel, a lens frame for holding a part or all of the lens group constituting the optical system, guide means for supporting the lens frame movably in the optical axis direction with respect to the fixed lens tube, and the lens Biasing means for biasing the frame toward one of the optical axis directions, and moving the lens frame toward the other against the biasing of the biasing means with respect to the fixed barrel In the lens driving device to be
A contact member provided in a part of the lens frame, a moving member that has a contact part that comes into contact with the one side and is supported so as to be movable in the optical axis direction;
A second urging means for urging the lens frame and the moving member in a direction in which the abutted portion and the abutting portion abut against each other and a stronger urging force than the urging means; ,
Both ends are fixed to the fixed lens barrel, and are contracted from a predetermined length of the relaxed state by being heated by energization, and return to the length of the relaxed state when cooled by stopping the energization. A memory alloy wire;
A wire bearing member that is provided on the moving member and on which a working portion that is set between both ends of the shape memory alloy wire is hooked so that a convex is in a curved direction facing the one side,
When the shape memory alloy wire is not energized, it holds the moving member with the length of the relaxed state, and when the shape memory alloy wire changes from the curved shape to the substantially linear shape by contracting the length by energization The lens driving device according to claim 1, wherein the lens frame is moved toward the other side against the urging force of the urging means through the moving member by displacement of the action portion in the optical axis direction.   The lens driving device according to claim 1, wherein the wire receiving member is provided with a pressing member that prevents the shape memory alloy wire from falling off.   A first wire support member that supports one end of the shape memory alloy wire, a first intermediate member that supports the opposite side of the one end across the action portion, and a shape that extends from the first intermediate member A second wire support member that supports the other end of the memory alloy wire, and a shape memory alloy wire between the first intermediate member and the second wire support member, along the front contour of the fixed barrel The lens driving device according to claim 1, further comprising a second intermediate member that is bent and supported as described above.   An imaging device having the lens driving device according to claim 1.

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