JP2009128629A - Zoom lens unit, lens-barrel for zoom lens unit, imaging device, camera, portable terminal device, and cellular phone - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a zoom lens unit capable of adjusting driving conditions of each group of lenses easily. <P>SOLUTION: This zoom lens unit 1 includes the lens-barrel 3, the group 7 of second lenses, the group 9 of third lenses, a first guide shaft 11, and a second guide shaft 13. A part of side face of the lens-barrel 3 is opened as an opening part 22. The group 7 of second lenses are provided with a mobile piece 35 held on the first guide shaft 11 by friction in a part where the first guide shaft 11 passes through, and the mobile piece 35 is provided with a screw 34a for adjustment. The group 9 of third lenses are provided with a mobile piece 45 held on the second guide shaft 13 by friction in a part where the second guide shaft 13 passes through, and the mobile piece 45 is provided with a screw 34b for adjustment. Consequently, it is possible to adjust holding force of the first and second guide shafts 11, 13 for the group 7 of second lenses and the group 9 of third lenses by operating the screws 34a, 34b for adjustment through the opening part 22 while a first lens frame 21 is assembled. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a zoom lens unit, a lens barrel for a zoom lens unit, an imaging device having a zoom lens unit, a camera, a mobile terminal device, and a mobile phone.

  The zoom lens unit is a lens unit that can continuously change the focal length without changing the focus position within a certain range, and is widely used in imaging devices such as cameras.

  The zoom lens unit usually has a structure in which a plurality of lenses and a drive mechanism are combined.

  Then, the lens is moved by the drive mechanism, and the focal distance is changed by changing the distance between the lenses, and zooming and focus correction are performed.

  Conventionally, many drive mechanisms for zoom lens units use electromagnetic rotary actuators such as stepping motors.

  On the other hand, in such a structure, the structure of the motor and the gear box is complicated, and it is difficult to reduce the size without reducing the torque.

  In addition, since the electromagnetic motor generates electromagnetic noise during rotation, the generated electromagnetic noise has a disadvantage that it adversely affects surrounding electronic devices.

  Therefore, in recent years, a structure using an ultrasonic actuator as a driving device has been developed.

  An ultrasonic actuator is an actuator that drives an object by vibrating a piezoelectric element at a constant period, and does not require a gear box and does not generate electromagnetic noise.

  For example, FIG. No. 8 describes a zoom lens unit in which an ultrasonic actuator (ultra-small piezoelectric actuator) is used as a driving unit for the second group lens and the second group lens and the third group lens are connected by a cam.

  In this case, the second group lens is driven by an ultrasonic actuator, and the third group lens is driven by a cam in conjunction with the driving of the second group lens.

  On the other hand, in the structure as in Non-Patent Document 1, since the cam is used, it is difficult to accurately match the optical axes of the lens groups, the structure is complicated, and each lens group is uniquely set. There were problems such as being unable to drive.

  Therefore, the present applicant has previously proposed a structure in which each lens group is driven independently using two ultrasonic actuators that also serve as guides (Patent Document 1).

Okamoto, Yoshida, Sueyoshi, “Development of ultra-small piezoelectric actuator”, Konica Minolta Technology Report, Konica Minolta, 2004, Vol. 1, p. 23-26 Japanese Patent Application No. 2007-151191

  The structure as in Patent Document 1 is a useful structure in that the optical axes of the lens groups can be accurately matched, the structure is simple, and each lens group can be independently driven.

  However, in the structure as in Patent Document 1, since the driving state (movement speed, etc.) of each lens group is affected by the holding force of the guide shaft with respect to the lens group, it is necessary to provide a means for adjusting the holding force. The structure is required to be easily adjusted in the manufacturing process.

  The present invention has been made in view of such problems, and an object thereof is to provide a zoom lens unit that can easily adjust the driving state of each lens group.

  In order to achieve the above-mentioned object, the first invention includes at least one lens and a lens frame that holds the lens, and is provided so that optical axes of the lenses coincide with each other. A plurality of lens groups movable in the axial direction, and provided so as to pass through and hold the lens frames of the plurality of lens groups and to be parallel to the optical axis. The direction is limited to the optical axis direction, and among the plurality of lens groups, a plurality of guide shafts that are ultrasonic actuators that drive the corresponding lens groups, and the guide shafts are provided on the plurality of lens groups. Adjusting means for adjusting the holding force with respect to the lens group, and a lens barrel provided around the plurality of lens groups and the guide shaft, and covering the plurality of lens groups and the guide shaft. The lens barrel is a zoom lens unit, wherein the opening for operating the adjustment means from the outside.

  The lens barrel includes a cylindrical body having a side surface provided with the opening, and a side frame detachably provided on the cylindrical body, and the side frame is provided so as to cover the opening. It has been.

  In this case, the cylindrical body has a concave portion and / or a convex portion provided in a portion in contact with the side frame, and the side frame is provided in a portion in contact with the cylindrical body, and the concave portion and / or the convex portion. The cylindrical body has a convex portion and / or a concave portion having a shape corresponding to the shape of the cylindrical body, and the convex portion and / or the concave portion of the side frame are engaged with the concave portion and / or the convex portion of the cylindrical body. And the side frame may be connectable.

  The adjusting means may be an adjusting screw for tightening the lens group and the guide shaft. In this case, the plurality of lens groups are provided to face each other and hold a pair of the guide shafts sandwiched between them. The adjusting screw may be provided through the pair of holding members.

  The side frame may be provided with a sensor for detecting a movement amount of the plurality of lens groups.

  The sensor may be a magnetic sensor. In this case, the lens group is provided with a magnetic body that is detected by the magnetic sensor so as to face the sensor.

  A second invention includes a plurality of lenses that include at least one lens and a lens frame that holds the lens, and are provided such that the optical axes of the lenses coincide with each other, and are movable in the optical axis direction. A lens group and a plurality of the lens groups are provided so as to penetrate the lens frame and parallel to the optical axis, and the moving direction of the plurality of lens groups is limited to the optical axis direction. A plurality of guide shafts which are ultrasonic actuators for driving the corresponding lens group among the plurality of lens groups, and a plurality of the lens groups, and the holding force of the guide shafts on the lens group is adjusted. And a lens barrel that is provided around the plurality of lens groups and the guide shaft, and covers the plurality of lens groups and the guide shaft. It is barrel zoom lens unit, wherein an opening for operating the adjustment means from the outside.

  The lens barrel includes a cylindrical body having a side surface provided with the opening, and a side frame detachably provided on the cylindrical body, and the side frame is provided so as to cover the opening. It has been.

  In this case, the cylindrical body has a concave portion and / or a convex portion provided in a portion in contact with the side frame, and the side frame is provided in a portion in contact with the cylindrical body, and the concave portion and / or the convex portion. The cylindrical body has a convex portion and / or a concave portion having a shape corresponding to the shape of the cylindrical body, and the convex portion and / or the concave portion of the side frame are engaged with the concave portion and / or the convex portion of the cylindrical body. And the side frame may be connectable.

  The side frame may be provided with a sensor for detecting a movement amount of the plurality of lens groups. In this case, the sensor may be a magnetic sensor.

  According to a third aspect of the present invention, there is provided an imaging apparatus having the zoom lens unit according to the first aspect of the present invention.

  A fourth invention is a camera having the zoom lens unit of the first invention.

  A fifth invention is a portable terminal device having the zoom lens unit of the first invention.

  A sixth invention is a cellular phone characterized by having the zoom lens unit of the first invention.

  In the first to sixth aspects of the invention, each lens group of the zoom lens unit is provided with adjusting means for adjusting the holding force of the guide shaft with respect to the lens group, and the lens barrel is provided with the adjusting means outside. An opening is provided for operation.

  Therefore, the driving state of each lens group can be easily adjusted even after the lens barrel is assembled.

  According to the present invention, it is possible to provide a zoom lens unit capable of easily adjusting the driving state of each lens group.

  DESCRIPTION OF EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail based on the drawings.

  First, a schematic configuration of the zoom lens unit 1 according to the first embodiment will be described with reference to FIGS.

  Here, as the zoom lens unit 1, a zoom lens unit used for a mobile phone or the like (camera) is illustrated.

  As shown in FIGS. 1 to 3, the zoom lens unit 1 includes a lens barrel 3 (first lens group), a second lens group 7, a third lens group 9, a first guide shaft 11, a second guide shaft 13, And a pedestal 4 (fourth lens group).

  As shown in FIGS. 1 to 3, the zoom lens unit 1 holds the first lens 23, the second lens group 7, the third lens group 9, and the first guide shaft 11 and the second guide shaft 13. 1 has a lens barrel 3 (first lens group).

  A second lens group 7 is provided so as to be adjacent to the first lens 23 and hold the second lens 31 and the third lens 32 (not shown) for zooming.

  The lens barrel 3 (first lens group) and the second lens group 7 are provided so that the optical axes 2 of the first lens 23, the second lens 31, and the third lens 32 coincide with each other.

  The second lens group 7 is movable in a direction parallel to the optical axis 2 (directions A1 and A2 in FIG. 2), and the magnification of the zoom lens unit 1 is changed by the movement.

  Further, the zoom lens unit 1 includes a third lens group 9 that holds a fourth lens 41 for focus correction.

  The third lens group 9 is provided adjacent to the second lens group 7 and at a position opposite to the upper surface 21a of the lens barrel 3 (first lens group) with the second lens group 7 interposed therebetween.

  The third lens group 9 is provided so that the optical axis of the fourth lens 41 coincides with the optical axis 2 of the first lens 23, the second lens 31, and the third lens 32.

  The third lens group 9 is movable in a direction parallel to the optical axis 2 (directions A1 and A2 in FIG. 2), and the focus of the zoom lens unit 1 is corrected by the movement.

  The first guide shaft 11 that restricts the movement of the second lens group 7 and the third lens group 9 in the direction parallel to the optical axis 2 and drives the second lens group 7 includes the second lens group 7 and the second lens group 7. The third lens group 9 is provided so as to pass through, and the second lens group 7 is held.

  Although details will be described later, the first guide shaft 11 is an ultrasonic actuator provided so as to be parallel to the optical axis 2.

  The second guide shaft 13 that restricts the movement of the second lens group 7 and the third lens group 9 in the direction parallel to the optical axis 2 and drives the third lens group 9 includes the second lens group 7 and the second lens group 9. The third lens group 9 is held through the third lens group 9.

  Although the details will be described later, the second guide shaft 13 is an ultrasonic actuator provided so as to be parallel to the optical axis 2.

  A plate-like base 4 (fourth lens group) having a fifth lens 71 at the ends of the first guide shaft 11 and the second guide shaft 13 and holding the first guide shaft 11 and the second guide shaft 13. Is provided.

  The pedestal 4 (fourth lens group) is provided so that the optical axis of the fifth lens 71 coincides with the optical axes 2 of the first lens 23, the second lens 31, the third lens 32, and the fourth lens 41. .

  The base 4 (fourth lens group) is provided adjacent to the third lens group 9 and at a position opposite to the second lens group 7 with the third lens group 9 in between.

  The pedestal 4 (fourth lens group) is connected to the lens barrel 3 (first lens group), and a second lens group 7, a third lens group 9, and a space formed inside by the pedestal 4 and the lens barrel 3, Part of the first guide shaft 11 and the second guide shaft 13 is accommodated.

  Next, among the members constituting the zoom lens unit 1, the lens barrel 3 (first lens group), the second lens group 7, the third lens group 9, the first guide shaft 11, the second guide shaft 13, and the pedestal 4. The structure of the (fourth lens group) will be described in detail with reference to FIGS.

  First, the structure of the lens barrel 3 (first lens group) will be described with reference to FIGS.

  As shown in FIGS. 2 to 4, the lens barrel 3 (first lens group) is detachably attached to the first lens frame 21 and a first lens frame 21 (cylindrical body) as a cylindrical body having an open bottom surface. A side frame 81 is provided.

  The first lens frame 21 has an upper surface 21a, and a first lens 23 that is a lens (concave lens) having a negative focal length is provided at the center of the upper surface 21a.

  Around the first lens 23 on the upper surface 21a of the first lens frame 21, a through hole 25 into which the first guide shaft 11 is inserted and a through hole 27 into which the second guide shaft 13 is inserted are provided.

  As shown in FIG. 4, a flange 3 a connected to the base 4 is provided around the bottom surface of the first lens frame 21, and a through-hole into which screws 8 b, 8 c and 8 d described later are inserted into the flange 3 a. Holes 6b, 6c, 6d (not shown) are provided.

  Further, a part of the side surface of the first lens frame 21 is opened as an opening 22.

  Concave portions 24 a and 24 b for connecting the side frame 81 and the first lens frame 21 are provided on the outer periphery of the upper surface 21 a on the opening 22 side.

  On the other hand, as shown in FIG. 4, the side frame 81 has a bowl-shaped main body 83.

  The side surface of the main body 83 has a shape with the same curvature as the side surface of the first lens frame 21, and the cylindrical portion of the lens barrel 3 is formed by connecting the side frame 81 and the first lens frame 21. Is done.

  In addition, convex portions 85 a and 85 b for connecting the side frame 81 and the first lens frame 21 are provided on the surface of the main body 83 that faces the first lens frame 21.

  The convex portions 85a and 85b have shapes corresponding to the concave portions 24a and 24b, and the side frame 81 and the first lens frame 21 are connected by engaging the convex portions 85a and 85b with the concave portions 24a and 24b.

  Further, a flange 83a connected to the base 4 is provided on the bottom surface of the main body 83, and a through hole 6a into which a screw 8a described later is inserted is provided in the flange 83a.

  When the side frame 81 and the first lens frame 21 are connected, the flange 3a and the flange 83a are integrated, and the flange portion of the lens barrel 3 is formed.

  Next, the structure of the second lens group 7 will be described with reference to FIGS.

  As shown in FIG. 3, the second lens group 7 has a plate-like second lens frame 29.

  At the center of the second lens frame 29, a second lens 31 and a third lens 32 (not shown) for zooming, which are lenses (convex lenses) having a positive focal length, are provided.

  In the vicinity of the outer periphery of the second lens frame 29, a mover 35 that is frictionally held by the first guide shaft 11 is provided in a portion through which the first guide shaft 11 passes.

  The moving element 35 is provided with a through hole 37 into which the first guide shaft 11 is inserted. The through-hole 37 is provided so that the through-hole 25 and the central axis coincide.

  Since the diameter of the through hole 37 is substantially equal to the diameter of a shaft 49 of the first guide shaft 11 to be described later, the movable element 35 is frictionally held by the first guide shaft 11.

  In the vicinity of the outer periphery of the second lens frame 29, a through hole 33 is further provided in a portion through which the second guide shaft 13 passes. The through-hole 33 is provided so that the through-hole 27 and the central axis coincide.

  Since the diameter of the through hole 33 is larger than the diameter of the shaft 55 of the second guide shaft 13 described later, the movement of the second guide shaft 13 and the second lens group 7 (second lens frame 29) is not restricted. .

  In addition, an attachment 38 for attaching a member for measuring the amount of movement of the second lens group 7 is provided on the side of the second lens frame 29 facing the opening 22. 38 is not used in the first embodiment.

  Here, with reference to FIG. 5, the structure around the moving element 35 will be described in more detail.

  As shown in FIG. 5A, the second lens frame 29 is provided with plate-like holding members 37a and 37b as a pair of holding members, and the moving member 35 is held by the holding members 37a and 37b. It is composed.

  The holding members 37a and 37b have semi-cylindrical curved recesses 30a and 30b on opposite surfaces, respectively, and the through holes 37 are formed by the curved recesses 30a and 30b.

  The holding members 37a and 37b have through holes 36a and 36b provided at positions adjacent to the curved recesses 30a and 30b so as to be perpendicular to the surface direction of the facing surface.

  As shown in FIG. 5B, the through holes 36a and 36b are provided with adjustment screws 34a as adjustment means for adjusting the holding force of the first guide shaft 11 with respect to the second lens group 7. It has been.

  Here, when the adjustment screw 34a is tightened, the holding members 37a and 37b of the moving element 35 are tightened to the adjustment screw 34a, and the first guide shaft 11 is moved in the directions of B1 and B2 in FIG. 5B, respectively. Press.

  Although the moving element 35 is frictionally held by the first guide shaft 11, since the holding force (friction force) is proportional to the vertical load, the holding force increases as the tightening force (contact pressure) increases.

  That is, the holding force can be adjusted using the adjusting screw 34a, and the driving state of the second lens group 7 described later can be adjusted.

  Next, the structure of the third lens group 9 will be described with reference to FIGS.

  As shown in FIG. 3, the third lens group 9 has a plate-like third lens frame 39.

  At the center of the third lens frame 39, a fourth lens 41 for focus correction, which is a lens (concave lens) having a negative focal length, is provided.

  In the vicinity of the outer periphery of the third lens frame 39, a through hole 43 is provided in a portion through which the first guide shaft 11 passes. The through hole 43 is provided so that the central axis thereof coincides with the through hole 25 and the through hole 37.

  Since the diameter of the through hole 43 is larger than the diameter of a shaft 49 of the first guide shaft 11 described later, the movement of the first guide shaft 11 and the third lens group 9 (third lens frame 39) is not restricted. .

  In the vicinity of the outer periphery of the third lens frame 39, a mover 45 that is frictionally held by the second guide shaft 13 is provided in a portion through which the second guide shaft 13 passes.

  The moving element 45 is provided with a through hole 47 into which the second guide shaft 13 is inserted. The through hole 47 is provided so that the central axis coincides with the through hole 27 and the through hole 33.

  Since the diameter of the through hole 47 is substantially equal to the diameter of the shaft 55 of the second guide shaft 13 to be described later, the moving element 45 is frictionally held by the second guide shaft 13.

  An attachment 48 for attaching a member for measuring the amount of movement of the third lens group 9 is provided on the surface of the third lens frame 39 facing the opening 22, but the attachment 48 is provided. 48 is not used in the first embodiment.

  Here, with reference to FIG. 6, the structure around the moving element 45 will be described in more detail.

  As shown in FIG. 6A, the third lens frame 39 is provided with plate-like holding members 47a and 47b as a pair of holding members, and the moving member 45 is held by the holding members 47a and 47b. It is composed.

  The holding members 47a and 47b have semi-cylindrical curved recesses 40a and 40b on the surfaces facing each other, and the through-holes 47 are configured by the curved recesses 40a and 40b.

  The holding members 47a and 47b have through holes 46a and 46b provided at positions adjacent to the curved concave portions 40a and 40b so as to be perpendicular to the surface direction of the facing surface.

  As shown in FIG. 6B, the through holes 46a and 46b are provided with adjustment screws 34b as adjustment means for adjusting the holding force of the second guide shaft 13 with respect to the third lens group 9. It has been.

  Here, when the adjusting screw 34b is tightened, the holding members 47a and 47b of the moving element 45 are tightened to the adjusting screw 34b, and the second guide shaft 13 is moved in the directions of B1 and B2 in FIG. 6B, respectively. Press.

  Although the moving element 45 is frictionally held by the second guide shaft 13, the holding force (friction force) is proportional to the vertical load, so that the holding force increases as the tightening force (contact pressure) increases.

  That is, the holding force can be adjusted using the adjusting screw 34b, and the driving state of the third lens group 9 described later can be adjusted.

  Next, the structure of the first guide shaft 11 and the second guide shaft 13 will be described with reference to FIG.

  As shown in FIG. 3, the first guide shaft 11 and the second guide shaft 13 have rod-shaped shafts 49 and 55, respectively.

  Disk-shaped piezoelectric elements 51 and 57 that warp when a voltage is applied are respectively provided at one ends of the shafts 49 and 55, and a power supply circuit (not shown) is connected to the piezoelectric elements 51 and 57. A power supply circuit (not shown) is connected to a controller (not shown) that controls the power supply circuit.

  Although details will be described later, the piezoelectric elements 51 and 57 are vibrated by warping upon receiving a voltage supplied from a power supply circuit (not shown), and move the second lens group 7 and the third lens group 9.

  The shaft 49 passes through the through hole 43 and further passes through the through hole 37 to frictionally hold the second lens group 7. The shaft 49 is press-fitted into the through hole 37.

  Further, among the end portions of the shaft 49, an end portion different from the end portion where the piezoelectric element 51 is provided is inserted into the through hole 25.

  The shaft 55 passes through the through hole 47 to frictionally hold the third lens group 9 and also passes through the through hole 33. The shaft 55 is press-fitted into the through hole 47.

  Further, of the end portions of the shaft 55, an end portion different from the end portion where the piezoelectric element 57 is provided is inserted into the through hole 27.

  The piezoelectric elements 51 and 57 are housed in piezoelectric element housing recesses 70a and 70b of a pedestal 4 (fourth lens group) to be described later, and the shafts 49 and 55 are inserted into and supported by the through holes 67a and 67b.

  Next, the structure of the base 4 (fourth lens group) will be described with reference to FIG.

  As shown in FIG. 3, the base 4 has a main body 61 and a lid 63.

  The main body 61 has a plate shape, and a fifth lens 71 that is a lens (convex lens) having a positive focal length is provided at the center.

  A through hole 77a for connecting the base 4 and the side frame 81 and through holes 77b, 77c, 77d for connecting the base 4 and the first lens frame 21 are provided on the outer periphery of the surface of the main body 61. .

  The through-hole 77a is provided so that the central axis coincides with the through-hole 6a, and the through-holes 77b, 77c, 77d are provided so that the central axes coincide with the through-holes 6b, 6c, 6d, respectively.

  Therefore, the side frame 81 is fixed to the base 4 (main body 61) by inserting the screw 8a into the through hole 6a and the through hole 77a and fastening the flange 83a and the main body 61.

  Further, by inserting the screws 8b, 8c, 8d into the through holes 6b, 6c, 6d and the through holes 77b, 77c, 77d, respectively, and fastening the flange 3a and the main body 61, the first lens frame 21 is fixed to the base 4 (main body 61).

  An annular lid housing recess 68 for housing the lid 63 is provided on the surface of the main body 61 so as to surround the periphery of the fifth lens 71.

  Disc-shaped piezoelectric element storage recesses 70 a and 70 b for storing the piezoelectric elements 51 and 57 are provided on the bottom surface of the lid storage recess 68.

  The piezoelectric element housing recesses 70a and 70b have shapes corresponding to the piezoelectric elements 51 and 57, and are provided so that the central axes thereof coincide with the axes 49 and 55, respectively.

  The lid 63 has a shape corresponding to the shape of the lid housing recess 68 and is detachably provided in the lid housing recess 68.

  The lid 63 has a through hole 65 having a shape corresponding to the shape of the fifth lens 71 at the center.

  In the vicinity of the outer periphery of the lid 63, through holes 67 a and 67 b for supporting the shafts 49 and 55 are further provided at positions where the shafts 49 and 55 penetrate.

  The through holes 67a and 67b are provided so that the axes 49 and 55 coincide with the central axis.

  That is, in the pedestal 4, when the lid 63 is accommodated in the lid accommodating recess 68, the piezoelectric element accommodating recesses 70 a and 70 b exist as spaces inside the pedestal 4, and the through holes 67 a and 67 b accommodate the piezoelectric element. It becomes a structure provided so that it may penetrate outside from the recessed parts 70a and 70b for use.

  The first guide shaft 11 and the second guide shaft 13 store the piezoelectric elements 51 and 57 in the piezoelectric element storage recesses 70 a and 70 b, and further insert the lid 63 into the lid storage recess 68. , 55 are inserted into the through holes 67a and 67b of the lid 63, and are accommodated in the base 4.

  Next, the principle and control method of the movement of the second lens group 7 and the third lens group 9 will be briefly described with reference to FIG.

  Here, the case where the second lens group 7 is moved in the direction of A1 in FIG. 7 will be described as an example. However, the same applies to the case where the third lens group 9 is moved.

  In order to move the second lens group 7 (second lens frame 29) in the direction of A1 in FIG. 7, first, a voltage is applied to the piezoelectric element 51 so that the piezoelectric element 51 warps in the direction of A1 in FIG. To load.

  Here, the speed at which the piezoelectric element 51 warps in the direction of A <b> 1 is a speed at which the moving element 35 does not slide with respect to the shaft 49.

  When the piezoelectric element 51 is warped in the direction of A1, the shaft 49 is integrated with the piezoelectric element 51 and moves by a predetermined length in the direction of A1, and the movable element 35 is also integrated with the shaft 49 and has a predetermined length. Just move.

  Next, the polarity of the voltage applied to the piezoelectric element 51 is reversed while the piezoelectric element 51 is warped in the direction of A1, and the piezoelectric element 51 is warped in the direction of A2 at a speed at which the slider 35 slides with respect to the shaft 49.

  When the piezoelectric element 51 is warped in the direction of A2, the shaft 49 is integrated with the piezoelectric element 51 and moves in the direction of A2, but the mover 35 slides with respect to the shaft 49.

  The slidable moving element 35 does not move due to inertia and remains at the same position as the position in which the piezoelectric element 51 is warped in the direction of A1.

  Thereafter, if the process of “turning the piezoelectric element 51 in the direction of A1 at a speed at which the moving element 35 does not slip” → “turning the piezoelectric element 51 in the direction of A2 at a speed at which the moving element 35 slides” is repeated, the moving element 35 becomes The second lens frame 29 (second lens group 7) sequentially moves in the direction of A1, and the second lens frame 29 (second lens group 7) moves in the direction of A1 together with the mover.

  That is, when the movable element 35 is vibrated at a constant period, the movable element 35 moves in the direction A1, and the second lens frame 29 (second lens group 7) moves together with the movable element 35 in the direction A1. To do.

  In order to move the second lens group 7 in the direction of A2, “the piezoelectric element 51 is warped in the direction of A2 at a speed at which the movable element 35 does not slip” → “the piezoelectric element 51 is moved at a speed at which the movable element 35 slides. The process of “warping in the direction of A1” is repeated to vibrate the piezoelectric element 51.

  The same applies to the case where the third lens group 9 is moved by vibrating the piezoelectric element 57.

  Here, the greater the holding force (frictional force) of the shafts 49 and 55 with respect to the movers 35 and 45, the greater the voltage required to slide the movers 35 and 45.

  That is, the drive state (movement speed, etc.) of the movers 35 and 45 is affected by the holding force (friction force).

  Therefore, the driving state of the second lens group 7 and the third lens group 9 can be adjusted by adjusting the holding force using the adjusting screws 34a and 34b.

  Next, an assembling method (manufacturing method) of the zoom lens unit 1 and a procedure for adjusting the driving state of the second lens group 7 and the third lens group 9 in the manufacturing process will be described with reference to FIGS.

  First, as shown in FIG. 8, it is assumed that all the members constituting the zoom lens unit 1 are in a disassembled state.

  From this state, first, the first guide shaft 11 and the second guide shaft 13 are moved in the direction of A2 in FIG. 8, and the piezoelectric elements 51 and 57 are stored in the piezoelectric element storage recesses 70a and 70b of the main body 61, respectively.

  When the piezoelectric elements 51 and 57 are accommodated, the lid 63 is moved in the direction of A2 in FIG. 8 and accommodated in the lid accommodating recess 68 of the main body 61.

  At this time, the first guide shaft 11 and the shafts 49 and 55 of the second guide shaft 13 pass through the through holes 67a and 67b of the lid 63, respectively.

  Next, the shaft 49 is inserted into the through holes 43 and 37, the shaft 55 is inserted into the through holes 47 and 33, and the second lens group 7 and the third lens group are connected to the first guide shaft 11 and the second guide shaft 13. 9 is attached.

  At this time, the adjusting screw 34a is inserted into the through holes 36a and 36b (see FIG. 5A) of the second lens group 7, and the through holes 46a and 46b of the third lens group 9 (see FIG. 6A). The adjustment screw 34b is inserted into.

  From this state, next, as shown in FIG. 9, the first lens frame 21 is moved in the direction of A2 in FIG. 9 to bring the flange 3a into contact with the main body 61 of the base 4, and the screws 8b, 8c, and 8d are respectively attached. It inserts in through-hole 6b, 6c, 6d (not shown) and through-hole 77b, 77c, 77d.

  By tightening the inserted screws 8b, 8c, and 8d, the flange 3a and the main body 61 are fastened, and the first lens frame 21 is fixed to the base 4 (main body 61).

  In this state, as shown in FIG. 10, the adjustment screws 34 a and 34 b are visible from the outside through the opening 22.

  Next, in the state shown in FIG. 10, by inserting a screwdriver or the like (not shown) from the opening 22 and operating the adjusting screws 34a and 34b (adjusting the tightening force), the first guide shaft 11 and the second guide The holding force of the shaft 13 with respect to the second lens group 7 and the third lens group 9 is adjusted.

  Thus, by providing the opening 22 in the first lens frame 21, the driving state of the second lens group 7 and the third lens group 9 can be adjusted even after the first lens frame 21 is attached. Become.

  When the adjustment is completed, as shown in FIG. 11, the side frame 81 is moved in the direction of A <b> 2 in FIG. 11, and the flange 83 a is brought into contact with the main body 61 of the base 4.

  At this time, the convex portions 85 a and 85 b of the side frame 81 are engaged with the concave portions 24 a and 24 b of the first lens frame 21, and the side frame 81 and the first lens frame 21 are connected to form the lens barrel 3.

  When the flange 83a contacts the main body 61 of the base 4, the screw 8a is inserted into the through hole 6a and the through hole 77a, and the screw 8a is tightened to fasten the flange 83a and the main body 61, and the side frame 81 is fixed to the base 4 (main body 61).

  In this way, the zoom lens unit 1 shown in FIG. 1 is completed.

  Thus, according to the first embodiment, the first lens frame 21 of the zoom lens unit 1 has the opening 22, and the second lens group 7 and the third lens group 9 have the adjusting screws 34a and 34b, respectively. In the state where the first lens frame 21 is assembled, the adjustment screws 34a and 34b are operated from the opening 22 (the tightening force is adjusted) to hold the first guide shaft 11 and the second guide shaft 13. It is possible to adjust the force.

  Therefore, the zoom lens unit 1 can easily adjust the driving state of each lens group.

  Next, the structure of the zoom lens unit 1a according to the second embodiment will be described with reference to FIGS.

  In the first embodiment, the zoom lens unit 1a according to the second embodiment is provided with a sensor for detecting the amount of movement of the second lens group 7 and the third lens group 9 in the side frame 81a.

  In the second embodiment, elements having the same functions as those in the first embodiment are denoted by the same reference numerals and description thereof is omitted.

  First, a schematic configuration of the zoom lens unit 1a will be described with reference to FIGS.

  As shown in FIGS. 12 and 13, the zoom lens unit 1a has a side frame 81a, and a substrate 101 is provided on the side frame 81a.

  The substrate 101 is fixed to the side frame 81 a with screws 105.

  As shown in FIG. 14, a magnetic sensor 107 a as a sensor for detecting the amount of movement of the second lens group 7 and the third lens group 9 is provided on the back surface (surface facing the opening 22) of the substrate 101. 107b is provided.

  Examples of the magnetic sensors 107a and 107b include MR (Magneto Resistance) sensors.

  On the other hand, as shown in FIG. 13, the attachment 38 of the second lens frame 29 is provided with a magnet scaler 103a that is a magnetic material, and the attachment 48 of the third lens frame 39 is provided with a magnet scaler 103b that is a magnetic material. Is provided.

  The magnet scalers 103a and 103b are provided so as to face the magnetic sensors 107a and 107b, respectively.

  The magnet scalers 103a and 103b move together in the directions of A1 and A2 when the second lens frame 29 and the third lens frame 39 move in the directions of A1 and A2 in FIG. 13, respectively. The sensors 107a and 107b detect the movement amounts of the magnet scalers 103a and 103b, respectively.

  For example, when the magnetic sensors 107a and 107b are MR sensors, the magnetic scalers 103a and 103b are detected by detecting changes in the magnetic field strength around the sensors as the magnet scalers 103a and 103b move as changes in the magnetic resistance of the MR sensor. The amount of movement of 103b is detected without contact.

  That is, the magnetic sensors 107a and 107b can detect the movement amounts of the second lens group 7 and the third lens group 9, respectively.

  Here, the structure of the side frame 81a and the substrate 101 will be described in more detail with reference to FIG.

  As shown in FIG. 15, the main body 83 of the side frame 81 a has a storage portion 86 a for storing the substrate 101.

  Slits 83b and 83c are provided at the end of the storage portion 86a.

  In addition, the storage portion 86a is provided with a through hole 82a into which the screw 105 is inserted.

  The substrate 101 has a plate-like shape, and protrusions 109 and 111 having shapes corresponding to the shapes of the slits 83b and 83c are provided at the ends.

  Further, the substrate 101 is provided with a through hole 101a into which the screw 105 is inserted. The through hole 101a is provided so that the central axis coincides with the through hole 82a.

  A circuit (not shown) for operating the magnetic sensors 107a and 107b is provided on the surface of the substrate 101, and the circuit (not shown) is connected to a controller (not shown) via a connector (not shown) and a flexible printed board (not shown).

  When the substrate 101 is provided on the side frame 81a, the substrate 101 is moved from the side of the slits 83b and 83c of the side frame 81a in the direction C in FIG. Mesh with.

  Furthermore, the board | substrate 101 is fixed to the side frame 81a by inserting the screw 105 in the through-hole 101a and the through-hole 82a, and fastening.

  Here, a circuit (not shown) for operating the magnetic sensors 107a and 107b is connected to a controller (not shown).

  Therefore, the information on the movement amounts of the second lens frame 29 and the third lens frame 39 (second lens group 7 and third lens group 9) detected by the magnetic sensors 107a and 107b is automatically transmitted to a controller (not shown). Feedback is provided to the driving of the piezoelectric elements 51 and 57.

  For example, when the movement amounts of the second lens group 7 and the third lens group 9 detected by the magnetic sensors 107a and 107b coincide with the movement amount that the controller (not shown) wants to move, the controller (not shown) sends the piezoelectric element 51, A command to stop driving (vibration) 57 is transmitted.

  Thus, by providing the magnetic sensors 107a and 107b, the positioning when moving the second lens group 7 and the third lens group 9 can be performed accurately.

  Thus, according to the second embodiment, the first lens frame 21 of the zoom lens unit 1a has the opening 22, and the second lens group 7 and the third lens group 9 have the adjusting screws 34a and 34b, respectively. In the state where the first lens frame 21 is assembled, it is possible to adjust the holding force of the first guide shaft 11 and the second guide shaft 13 by operating the adjusting screws 34a and 34b from the opening 22. is there.

  Accordingly, the same effects as those of the first embodiment are obtained.

  Further, according to the second embodiment, the second lens frame 29 and the third lens frame 39 are provided with the magnet scalers 103a and 103b, and the side frame 81a detects the movement amount of the magnet scalers 103a and 103b. Magnetic sensors 107a and 107b are provided.

  Therefore, the positioning when moving the second lens group 7 and the third lens group 9 can be performed accurately.

  In the above-described embodiment, the case where the present invention is applied to a camera such as a mobile phone has been described. However, the present invention is not limited to this, for example, an imaging apparatus that requires the zoom lens unit 1, It can be used for cameras, portable terminal devices, and the like.

1 is a perspective view showing a zoom lens unit 1. FIG. FIG. 2 is an exploded perspective view of FIG. 1. FIG. 2 is an exploded perspective view of FIG. 1. FIG. 4 is an exploded perspective view of the lens barrel 3 of FIG. 3. FIG. 5A is a plan view showing the second lens group 7, and FIG. 5B is a plan view showing the periphery of the second lens group 7 in a state where the zoom lens unit 1 is assembled. FIG. 6A is a plan view showing the third lens group 9, and FIG. 6B is a plan view showing the periphery of the third lens group 9 in a state where the zoom lens unit 1 is assembled. FIG. 2 is a view taken in the direction of the arrow A in FIG. FIG. 3 is a diagram illustrating an assembly procedure of the zoom lens unit 1. FIG. 3 is a diagram illustrating an assembly procedure of the zoom lens unit 1. FIG. 3 is a diagram illustrating an assembly procedure of the zoom lens unit 1. FIG. 3 is a diagram illustrating an assembly procedure of the zoom lens unit 1. It is a perspective view which shows the zoom lens unit 1a. It is a disassembled perspective view of FIG. In FIG. 13, it is a perspective view at the time of seeing the side frame 81a from the back side. It is a disassembled perspective view of the side frame 81a.

Explanation of symbols

1 …… Zoom lens unit 2 ………… Optical axis 3 ………… Tube (first lens group)
4 …… Pedestal (fourth lens group)
7 ………… Second lens group 9 ………… Third lens group 11 ………… First guide shaft 13 ……… Second guide shaft 21 ……… First lens frame 22 ……… Opening portion 23 ...... First lens 25 ......... Through hole 27 ......... Through hole 29 ......... Second lens frame 31 ......... Second lens 33 ......... Through hole 34a ... Adjustment screw 35 ......... Mover 37 ......... Through hole 39 ......... Third lens frame 41 ......... Fourth lens 43 ......... Through hole 45 ......... Mover 47 ...... Through hole 49 ......... Shaft 51 ......... Piezoelectric element 55 ......... Axis 57 ......... Piezoelectric element 71 ......... Fifth lens 81 ......... Side frame 81a ... Side frame 101 ... Substrate 107a ... Magnetic sensor

Claims (16)

A plurality of lens groups that include at least one lens and a lens frame that holds the lens, and are provided such that the optical axes of the lenses coincide with each other, and are movable in the optical axis direction;
The plurality of lens groups are provided so as to pass through the lens frames and parallel to the optical axis, and the moving direction of the plurality of lens groups is limited to the optical axis direction. A plurality of guide shafts that are ultrasonic actuators for driving the corresponding lens group,
An adjusting means provided in a plurality of the lens groups, for adjusting a holding force of the guide shaft with respect to the lens group;
A plurality of lens groups and a guide tube provided around the guide shaft and covering the plurality of lens groups and the guide shaft;
Have
The lens barrel is provided with an opening for operating the adjusting means from the outside. The lens barrel is
A cylinder having a side surface provided with the opening;
A side frame detachably provided on the cylindrical body;
Have
The zoom lens unit according to claim 1, wherein the side frame is provided so as to cover the opening. The cylindrical body has a concave portion and / or a convex portion provided in a portion in contact with the side frame,
The side frame is provided at a portion in contact with the cylindrical body, and has a convex portion and / or a concave portion having a shape corresponding to the shape of the concave portion and / or the convex portion,
The said cylinder and the said side frame can be connected by mesh | engaging the said convex part and / or recessed part of the said side frame with the said recessed part and / or convex part of the said cylinder. Zoom lens unit.   The zoom lens unit according to claim 1, wherein the adjusting unit is an adjusting screw for tightening the lens group and the guide shaft. The plurality of lens groups are
A pair of holding members that are provided facing each other and sandwich and hold the guide shaft;
The zoom lens unit according to claim 4, wherein the adjustment screw is provided so as to penetrate a pair of holding members.   The zoom lens unit according to claim 2, wherein a sensor for detecting a movement amount of the plurality of lens groups is provided in the side frame. The sensor is a magnetic sensor;
The zoom lens unit according to claim 6, wherein the lens group is provided with a magnetic body that is detected by the magnetic sensor so as to face the sensor. A plurality of lens groups that include at least one lens and a lens frame that holds the lens, and are provided such that optical axes of the lenses coincide with each other, and are movable in the optical axis direction; The lens group is provided so as to penetrate the lens frame and parallel to the optical axis, and the movement direction of the plurality of lens groups is limited to the optical axis direction, and the plurality of lens groups A plurality of guide shafts that are ultrasonic actuators that drive the corresponding lens group, and an adjustment unit that is provided in the plurality of lens groups and adjusts the holding force of the guide shaft with respect to the lens group. A lens barrel that is provided around the plurality of lens groups and the guide shaft of the zoom lens unit and covers the plurality of lens groups and the guide shaft,
A lens barrel for a zoom lens unit, wherein an opening for operating the adjusting means from the outside is provided. The lens barrel is
A cylinder having a side surface provided with the opening;
A side frame detachably provided on the cylindrical body;
Have
The zoom lens unit barrel according to claim 8, wherein the side frame is provided so as to cover the opening. The cylindrical body has a concave portion and / or a convex portion provided in a portion in contact with the side frame,
The side frame is provided at a portion in contact with the cylindrical body, and has a convex portion and / or a concave portion having a shape corresponding to the shape of the concave portion and / or the convex portion,
The said cylinder and the said side frame can be connected by mesh | engaging the said convex part and / or recessed part of the said side frame with the said recessed part and / or convex part of the said cylinder. Zoom lens unit barrel.   The zoom lens unit barrel according to claim 9, wherein the side frame is provided with a sensor for detecting a movement amount of the plurality of lens groups.   The zoom lens unit according to claim 11, wherein the sensor is a magnetic sensor.   An image pickup apparatus comprising the zoom lens unit according to claim 1.   A camera comprising the zoom lens unit according to claim 1.   A portable terminal device comprising the zoom lens unit according to claim 1.   A mobile phone comprising the zoom lens unit according to claim 1.

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