JP2016033572A - Oscillation actuator and lens barrel using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lens barrel that enables a structure with a contact pressure force unchanged even if an external impact or the like is applied in a direct-acting type oscillation actuator, and can obtain a stable drive characteristic.SOLUTION: A lens barrel comprises: a lens guide shaft that movably supports a lens frame; a main body frame that holds the lens guide shaft; a slider that comes into contact with a drive shaft; an oscillator that is fixed to any one of the drive shaft or the slider; a drive guide shaft that supports the slider movably in parallel with the drive shaft; a drive case that holds the drive shaft and the drive guide shaft; an output shaft that is rotatable centering around a shaft almost in parallel with the drive guide shaft, and is supported movably in a shaft direction integrally with the slider; a pressure spring that presses the output shaft against the lens frame; and a connection part of the output shaft and the lens frame that transmits a drive force in an optical axis to the lens frame, and is slidable toward a direction almost orthogonal to a pressure direction in a direction orthogonal to the lens guide shaft.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a vibration actuator using vibration of a vibrating body and a lens barrel configured to move a lens group using the vibration actuator.

  Conventionally, a driven lens is brought into pressure contact with a vibrating body composed of a vibrator such as a piezoelectric element with respect to a moving lens group in a lens barrel, and the moving lens is vibrated, so that the moving lens is caused by the frictional force of the pressure contact portion. Vibration actuators that move the group relatively are known.

  Patent Document 1 discloses a configuration in which a moving lens group is moved in the optical axis direction using a linear motion type vibration actuator that moves along a drive shaft extending in the optical axis direction. The slider movement guide shaft is integrally provided, and the driven member is detachably attached. The actuator is unitized.

Japanese Patent No. 3170999

  However, in the case of a lens barrel that uses such a direct-acting vibration actuator as an actuator for a movable lens group, the slider is directly connected to the frictional force adding member, the drive shaft, and the moving body, so the press contact portion is Susceptible to external influences. For example, if an external impact is applied due to a drop, vibration, or collision caused by the user, the friction force application member or slider is deformed or damaged, the drive shaft is directly affected, and the pressure contact force changes. End up. As a result, drive characteristics deteriorate. Therefore, a structure is required in which the pressure contact force of the vibration actuator does not change even when an external impact or the like is applied to the lens barrel.

  Accordingly, an object of the present invention is to provide a lens barrel that enables a structure in which a pressure contact force does not change even when an external impact or the like is applied in a direct acting type vibration actuator, and which can obtain stable driving characteristics. To do.

  In addition, if there is a backlash between the lens holding frame, which is a movement target, and the lens guide shaft, there is a problem that image shake occurs or an impact sound occurs in the output image. Against this, in the present invention, play is prevented by using the pressure contact force.

In order to achieve the above object, the present invention provides:
A lens,
A lens frame for holding the lens;
A lens guide shaft that movably supports the lens frame;
A body frame for holding the lens guide shaft;
A drive shaft;
A slider that contacts the drive shaft;
A vibrator fixed to either the drive shaft or the slider;
A drive guide shaft that supports the slider so as to be movable parallel to the drive shaft;
A drive case for holding the drive shaft and the drive guide shaft;
An output shaft that is rotatable about an axis substantially parallel to the drive guide shaft, and is supported so as to be movable in the axial direction integrally with the slider;
A pressing spring that presses the output shaft against the lens frame;
The connecting portion between the output shaft and the lens frame transmits a driving force to the lens frame in the optical axis direction, and is slidable in a direction perpendicular to the lens guide shaft and substantially perpendicular to the pressing direction. It has the connection part.

  According to the present invention, in a moving lens group using a direct-acting type vibration actuator, a lens barrel that enables a structure in which a pressure contact force does not change even when an external impact or the like is applied, and a stable driving characteristic is obtained. Can be provided. Furthermore, according to the present invention, the lens holding frame can be easily urged with a predetermined force with respect to the lens guide shaft of the lens holding frame without any additional member. Is effective.

Exploded view of the drive unit of the first embodiment Sectional view of the lens barrel of the first embodiment The perspective view of the drive part of 1st Example The figure which looked at the drive part of the 1st example from the top The figure which looked at the drive part of the 1st example from the optical axis direction of the 4th lens holding frame AA sectional view in which the connecting portion of the first embodiment is cut along a plane perpendicular to the optical axis. BB sectional drawing of the press-contact part of the 4th lens holding frame of 1st Example CC sectional view of the tension coil spring part of the first embodiment Exploded view of the second embodiment The top view of the drive unit of the second embodiment DD sectional drawing which cut | disconnected the connection part of 2nd Example by the surface perpendicular | vertical to an optical axis EE sectional drawing of the coil spring part of 2nd Example.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

  Hereinafter, a first embodiment to which the present invention is applied will be described with reference to FIGS. In the figure, the optical axis direction is set as the Z axis, the X axis is set in the direction shown in the figure in the optical axis orthogonal direction, and the direction perpendicular to the X axis is set as the Y axis. FIG. 2 is a sectional view of the lens barrel 1 according to the embodiment of the present invention.

  The lens barrel 1 has a four-group configuration including a first lens group 2, a second lens group 3, a third lens group 4, and a fourth lens group 5, and a light amount adjusting diaphragm mechanism 6 is provided between the third lens groups 4. This is a lens barrel having an image sensor (not shown) behind the four lens group 5. The first lens holding frame 21 holds the first lens group 2. The second lens holding frame 31 holds the second lens group 3. The third lens holding frame 41 holds the third lens group, and the second lens group 3 is movable in the optical axis direction by a zooming optical system. The fourth lens holding frame 51 holds the fourth lens group 5, and the fourth lens group 5 is movable in the optical axis direction by a focusing optical system. The fixed frame 72 holds the first lens holding frame 21 and the miscellaneous image element holding frame 71.

  Of these optical systems described above, the present invention will be described below as an example in which the present invention is applied to the fourth lens group 5 for focusing. However, the present invention is not limited to this and is applied to an optical system for zooming. it can.

  FIG. 3 is a perspective view of a fourth lens group 5 that is a moving lens group according to the embodiment, a drive unit 10 that is an actuator that moves the fourth lens group 5, and the surrounding configuration. Further, an exploded view is shown in FIG. 1 so that the internal configuration of the drive unit 10 can be easily grasped.

  The fourth lens holding frame 51 is held by the main lens guide shaft 8 and the sub lens guide shaft 9 so as to be movable in the optical axis direction. The main lens guide shaft 8 and the sub lens guide shaft 9 are fixed by an image sensor holding frame 71 and a third lens holding frame 41 to which the third lens group 4 is fixed.

  The fourth lens holding frame 51 includes a position detection sensor 52 and a portion for transmitting the output from the drive unit 10, and the position of the actuator is determined by determining the output of the actuator based on the target position and the output of the sensor 52. .

  The drive unit will be described mainly with reference to FIGS. In the drive case 101, a drive member in which the piezoelectric element 103 is coupled to the drive shaft 102 is bonded and held at the drive shaft holding portion 101d by a silicon-based adhesive or the like. The drive case 101 holds a drive guide shaft 104 for guiding the driven body 106 in the moving direction by a drive guide shaft holding portion 101e, and is driven between the drive shaft holding portion 101d and the drive guide shaft holding portion 101e. It has the partition wall 101a which partitions off the space in a case. The drive case 101 is attached by screwing the screwing portions 101b and 101c to the image sensor holding frame 71 as a fixing member with a screw 111.

  The driven body 106 holds the drive bearing sheet metal 105, and the pressing plate spring 107 biases the driving shaft 102 with a predetermined force so that the driving bearing sheet metal 105 and the pressing plate spring 107 sandwich the driving shaft 102 in parallel. Thus, it is fixed to the driven body 106. In this embodiment, the claw portion 106b of the driven body 106 is hung by the hole 107b of the pressing plate spring 107, and the hooking portion 106f of the driven body 106 is hooked by the locking portion 107f of the pressing plate spring 107. The leaf spring 107 is fixed to the driven body 106. The driven body 106 is held by the drive guide shaft holding portion 106c while being slidable in the optical axis direction by the drive guide shaft 104.

  As a result, a pressure contact force is generated between the pressure contact portion 13 of the drive shaft 102 and the drive bearing metal plate 105 and the pressure contact portion 14 of the drive shaft 102 and the pressing plate spring 107. Therefore, when the drive shaft 102 connected to the piezoelectric element 103 vibrates in the axial direction, the driven member 106 moves along the drive guide shaft 104 by the drive bearing metal plate 105 and the pressing plate spring 107.

  As shown in FIG. 6, in the present invention, the drive shaft is pressed in two places by a flat surface and a flat surface like the press contact portions 13 and 14, but the drive shaft and the drive guide shaft are parallel or the drive guide shaft is fitted. By making the hole to be combined into a long hole, it may be press-contacted at two or more places by a V groove and a flat surface. The lid 112 is fixed to the drive case 101.

  Further, as shown in FIG. 6, the driven body 106 has a concave portion 106d for avoiding the partition wall 101a between the pressure contact portions 13, 14 and the driving guide shaft holding portion 106c. Furthermore, the driven body 106 has a connecting member 109 for connecting to the fourth lens holding frame 51 on the drive guide shaft 104 side with respect to the partition wall 101a. The connecting member 109 can rotate on an axis parallel to the drive guide shaft 104 and is attached to the attaching portion 106g and the attaching portion 106h of the driven body 106 by the attaching portion 109b and the attaching portion 109c of the connecting member 109. A connecting portion side spring 110 that is a tension coil spring is attached to the spring attaching portion 109 d of the connecting member 109 and the spring attaching portion 106 i of the driven body 106.

  The connecting member 109 is offset in the rotational direction and the driving direction with respect to the driven body 106 with respect to the driven body 106 by the connecting portion offset spring 110. Accordingly, the pressure contact portion 109 a of the connection member 109 is pressed against the pressure contact portion 51 a of the fourth lens holding frame 51 by the connection portion side spring 110. With the above configuration, the connecting member 109 is offset in the moving direction by the driven body 106 and is offset in the rotational direction around the attachment portions 106g and 106h.

  The structure of a connection part is demonstrated. The shape of the pressure contact portion 109a of the connecting member 109 is spherical. The shape of the pressure contact portion 51 a of the fourth lens holding frame 51 has two surfaces that have a ridge line 51 b in a plane perpendicular to the lens guide shaft 8 and press the pressure contact portion 109 a of the connecting member 109 in a direction parallel to the lens guide shaft 8. V-shape having The pressure contact portion 109 a of the connecting member 109 and the pressure contact portion 51 a of the fourth lens holding frame 51 are in pressure contact with each other in the Y direction by the connection portion bias spring 110.

  As shown in FIG. 6, the press contact portion 109 a of the connecting member 109 is incorporated into the press contact portion 51 a of the fourth lens holding frame 51. The coupling member 109 rotates relative to the driven body 109 with respect to the positional deviation in the Y direction between the lens guide shaft 8 and the drive guide shaft 104. Further, the contact portion of the press contact portion changes in the X direction with respect to the positional deviation of the lens guide shaft 8 and the drive guide shaft 104 in the X direction. As a result, they are connected in a row.

  With the above configuration, even if the fourth lens holding frame 51 moves in the direction perpendicular to the optical axis due to impact, the impact force is applied to the press contact portions 13 and 14 of the drive shaft 102 by the rotation of the connecting member 109 and the movement of the press contact portion 109a. Will not take.

  The force in the Y direction in which the pressure contact portion 109 a of the connecting member 109 is in pressure contact with the lens guide shaft 8 is in a different direction. Due to this pressure contact force, the fourth lens holding frame 51 is biased to the lens guide shaft 8, and is also biased to the lens guide shaft 9 by a force to rotate around the lens guide shaft 8. A gap is provided between the fourth lens moving frame 51 and the lens guide shafts 8 and 9 so as to be movable. However, due to this offset, the fourth lens holding frame 51 can move along the lens guide shafts 8 and 9 without any difficulty.

  The drive unit 10 described above is a direct-acting type vibration actuator in which the driven body 106 that is in pressure contact moves along the drive guide shaft 104 when the drive shaft 102 connected to the piezoelectric element 103 vibrates. . The connecting member 109 protruding from the drive unit 10 transmits the driving force to the fourth lens holding frame 51, and the fourth lens holding frame 51 can move along the main lens guide shaft 8.

  As described above, even when the position 104 of the drive guide shaft of the drive unit 10 and the position of the lens guide shaft 8 are deviated, the connected state is maintained.

  Further, even if the fourth lens holding frame 51 moves in the direction perpendicular to the driving direction due to dropping or the like, the force applied to the driving shaft 102 does not change greatly, and the press contact portion is not damaged.

  The drive unit 10 can be easily attached from the V-shaped opening direction of the connecting portion of the fourth lens holding frame 51.

  In addition, the offset structure of the connecting portion between the fourth lens holding frame and the connecting member of the present embodiment is a V-shape and a sphere, but if it is a structure that transmits force in the driving direction at the offset abutting portion, It may be other than a sphere. Regarding the relationship between the V shape and the sphere, the fourth lens holding frame may have a spherical portion, and the connecting member may have a V shape.

  A second embodiment to which the present invention is applied will be described below with reference to FIGS. The second embodiment is a modified type of the connecting member 109 in the first embodiment, and the description of the common part with the first embodiment is omitted.

  The drive unit will be described mainly with reference to FIGS. In the drive case 201, a drive member in which the piezoelectric element 103 is connected to the drive shaft 102 is bonded and held by the drive shaft holding portion 201d with a silicon-based adhesive or the like. The drive case 201 holds the drive guide shaft 204 for guiding the driven body 206 in the moving direction by the drive guide shaft holding portion 201e, and is driven between the drive shaft holding portion 201d and the drive guide shaft holding portion 201e. It has the partition wall 201a which partitions off the space in a case. The drive case 201 is attached by screwing the screwing portions 201b and 201c to the image sensor holding frame 71 as a fixing member with a screw 111.

  The driven body 206 holds the drive bearing sheet metal 105, and the pressing plate spring 107 biases the driving shaft 102 with a predetermined force so that the driving bearing sheet metal 105 and the pressing plate spring 107 sandwich the driving shaft 102 in parallel. Thus, it is fixed to the driven body 206. In this embodiment, the claw portion 206b of the driven body 206 is hung by the hole 107b of the pressing plate spring 107, and the hooking portion 206f of the driven body 206 is hooked by the locking portion 107f of the pressing plate spring 107. The leaf spring 107 is fixed to the driven body 206. The driven body 206 is held by the drive guide shaft holding portion 206c while being slidable by the drive guide shaft 204 in the optical axis direction.

  As a result, a pressure contact force is generated between the pressure contact portion 13 of the drive shaft 102 and the drive bearing metal plate 105 and the pressure contact portion 14 of the drive shaft 102 and the pressing plate spring 107. Thus, when the drive shaft 102 connected to the piezoelectric element 103 vibrates in the axial direction, the driven body 206 moves along the drive guide shaft 204 by the drive bearing metal plate 105 and the pressing plate spring 107.

  As shown in FIG. 12, in the present invention, the drive shaft is pressed in two places by a plane and a plane like the press contact portions 13 and 14, but the drive shaft and the drive guide shaft are parallel or the drive guide shaft is fitted. By making the hole to be combined into a long hole, it may be press-contacted at two or more places by a V groove and a flat surface.

  Further, as shown in FIG. 12, the driven body 206 has a recess 206d for avoiding the partition wall 201a between the pressure contact portions 13, 14 and the drive guide shaft holding portion 206c. Furthermore, the driven body 206 has a connecting member 209 for connecting to the fourth lens holding frame 51 on the drive guide shaft 204 side with respect to the partition wall 201a. The lid 112 is fixed to the drive case 201.

  The connecting member 209 is attached to the drive guide shaft 204 so as to be rotatable and movable in the drive direction. A connecting portion bias spring 210 that is a coil spring is passed through the drive guide shaft 204. The end portion 210 a of the connecting portion bias spring 210 is locked to the spring mounting portion 209 b of the connecting member 209, and the other end portion 210 b of the connecting portion bias spring 210 is locked to the spring mounting portion 206 g of the driven body 206. And offset in the twisting direction. Further, the connecting portion side spring 210 abuts against the abutting portion 210b of the connecting member 209, and the connecting portion side spring 210 abuts against the abutting portion 206g of the driven body 206 and is offset in the driving direction. The pressure contact portion 209 a of the connection member 209 is pressed against the pressure contact portion 51 a of the fourth lens holding frame 51 by the connection portion side spring 210. With the above configuration, the connecting member 209 is offset in the moving direction by the driven body 206, and is offset in the rotational direction around the drive guide shaft 204.

  The structure of a connection part is demonstrated. The shape of the pressure contact portion 209a of the connecting member 209 is spherical. The shape of the pressure contact portion 51 a of the fourth lens holding frame 51 has two surfaces that have a ridge line 51 b in a plane perpendicular to the lens guide shaft 8 and press the pressure contact portion 209 a of the connecting member 209 in a direction parallel to the lens guide shaft 8. V-shape having The pressure contact portion 209 a of the connection member 209 and the pressure contact portion 51 a of the fourth lens holding frame 51 are in pressure contact with each other in the Y direction by the connection portion bias spring 210.

  The press contact portion 209a of the connecting member 209 is incorporated into the press contact portion 51a of the fourth lens holding frame 51 as shown in FIG. The connecting member 209 rotates relative to the driven body 209 with respect to the positional deviation in the Y direction between the lens guide shaft 8 and the drive guide shaft 204. Further, the contact portion of the pressure contact portion changes in the X direction with respect to the positional deviation in the X direction between the lens guide shaft 8 and the drive guide shaft 204. As a result, they are connected with each other.

  With the above configuration, even if the fourth lens holding frame 51 moves in the direction perpendicular to the optical axis due to an impact, the impact force is applied to the pressure contact portions 13 and 14 of the drive shaft 102 by the rotation of the connecting member 209 and the movement of the pressure contact portion 209a. Will not take.

  The force in the Y direction in which the pressure contact portion 209a of the connecting member 209 is in pressure contact is in pressure contact with the lens guide shaft 8 in a different direction. Due to this pressure contact force, the fourth lens holding frame 51 is biased to the lens guide shaft 8, and is also biased to the lens guide shaft 9 by a force to rotate around the lens guide shaft 8. A gap is provided between the fourth lens moving frame 51 and the lens guide shafts 8 and 9 so as to be movable. However, due to this offset, the fourth lens holding frame 51 can move along the lens guide shafts 8 and 9 without any difficulty.

  The drive unit 20 described above is a direct-acting type vibration actuator in which the driven body 206 brought into pressure contact moves along the drive guide shaft 204 when the drive shaft 102 connected to the piezoelectric element 103 vibrates. The connecting member 209 protruding from the drive unit 20 transmits the driving force to the fourth lens holding frame 51, and the fourth lens holding frame 51 can move along the main lens guide shaft 8.

  As described above, even when the position 204 of the drive guide shaft of the drive unit 20 and the position of the lens guide shaft 8 are deviated, the connected state is maintained.

  Further, even if the fourth lens holding frame 51 moves in the direction perpendicular to the driving direction due to dropping or the like, the force applied to the driving shaft 102 does not change greatly, and the press contact portion is not damaged.

  The drive unit 20 can be easily attached from the V-shaped opening direction of the connecting portion of the fourth lens holding frame 51.

  In addition, the offset structure of the connecting portion between the fourth lens holding frame and the connecting member of the present embodiment is a V-shape and a sphere, but if it is a structure that transmits force in the driving direction at the offset abutting portion, It may be other than a sphere. Regarding the relationship between the V shape and the sphere, the fourth lens holding frame may have a spherical portion, and the connecting member may have a V shape.

  In addition, although the first and second embodiments are provided with the vibrator on the drive shaft, the vibrator may be provided on the driven body.

  As mentioned above, although preferable embodiment of this invention was described, this invention is not limited to these embodiment, A various deformation | transformation and change are possible within the range of the summary.

  As mentioned above, although preferable embodiment of this invention was described, this invention is not limited to these embodiment, A various deformation | transformation and change are possible within the range of the summary.

1 lens barrel, 2 first lens group, 3 second lens group, 4 third lens group,
5 Fourth lens group, 6 Light quantity adjusting diaphragm mechanism, 8 Main lens guide shaft,
9 Sub lens guide shaft, 10 drive unit, 13 pressure contact part, 14 pressure contact part,
21 First lens holding frame, 31 Second lens holding frame, 41 Third lens holding frame,
51 Fourth lens holding frame, 51a pressure contact part, 51b ridge line, 52 sensor,
71 Image sensor holding frame, 72 fixed frame, 101 drive case, 101a partition wall,
101b, 101c screwing part, 101d drive shaft holding part,
101e Drive guide shaft holder, 102 Drive shaft, 103 Piezoelectric element,
104 drive guide shaft, 105 drive bearing sheet metal, 105 drive bearing sheet metal,
106 driven body, 106b claw portion, 106c driving guide shaft holding portion, 106d concave portion,
106f spring mounting part, 106f hooking part, 106g mounting part,
106h Mounting portion, 107 Pressing leaf spring, 107b Hole portion, 107b Hole portion,
107f Locking part, 109 connecting member, 109a pressure contact part, 109b mounting part,
109c mounting part, 109d spring mounting part, 110 connecting part side spring,
111 screws, 112 lids, 201 drive cases, 201a partition walls,
201b, 201c screwing part, 201d drive shaft holding part,
201e driving guide shaft holding portion, 204 driving guide shaft, 206 driven body,
206b claw portion, 206c driving guide shaft holding portion, 206d concave portion,
206f hook part, 206g butting part, 209a pressure contact part,
209b Spring mounting part, 209g Spring mounting part, 210 Linking part side spring,
210a, 10b end, 210c butting part

Claims (4)

A lens,
A lens frame for holding the lens;
A lens guide shaft that movably supports the lens frame;
A body frame for holding the lens guide shaft;
A drive shaft;
A slider that contacts the drive shaft;
A vibrator fixed to either the drive shaft or the slider;
A drive guide shaft that supports the slider so as to be movable parallel to the drive shaft;
A drive case for holding the drive shaft and the drive guide shaft;
An output shaft that is rotatable about an axis substantially parallel to the drive guide shaft, and is supported so as to be movable in the axial direction integrally with the slider;
A pressing spring that presses the output shaft against the lens frame;
The connecting portion between the output shaft and the lens frame transmits a driving force to the lens frame in the optical axis direction and is slidable in a direction perpendicular to the lens guide shaft and perpendicular to the pressing direction. A lens barrel having a portion.   The lens barrel according to claim 1, wherein a connecting portion between the lens frame and the output shaft has a V groove and a spherical shape.   The lens barrel according to claim 1, wherein the slider and the output shaft are pressed along the drive shaft by a spring.   The lens according to any one of claims 1 to 3, wherein the force that the output shaft presses against the lens frame is applied in a direction in which the lens frame is pressed against the lens guide shaft. A lens barrel.