JP2012048159A - Lens barrel and imaging apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an imaging apparatus having a drive mechanism that employs a lead screw generating less noise during driving operations.SOLUTION: A digital camera which is an imaging apparatus includes a fixed frame 13, a fourth group lens 24 which is a focus lens group, a fourth group frame 12 for holding the fourth group lens 24, and a focus driving unit 60 which is provided on the outer periphery of the fixed frame 13 and includes a focus motor 61 and a rotation transmitting mechanism 59 for focus driving of the fourth group lens 24. The rotation transmitting mechanism 59 comprises a lead screw 66 for driving the fourth group lens 12 forward and backward, a pair of nuts 64A and 64B screwed to the lead screw 66 and arranged opposite to each other, a guide groove 13e to which a rotation regulating projection 64b of each of the nuts 64A and 64B is fitted, and a torsion spring 69 provided between the nuts 64A and 64B, biasing the nuts 64A and 64B in a direction of separating them from each other, and also biasing the nuts 64A and 64B in opposite rotation directions.

Description

  The present invention relates to a lens barrel and an imaging apparatus to which a drive mechanism using a lead screw is applied.

  A conventional lens frame advance / retreat mechanism that applies a drive mechanism that applies a lead screw in a conventional imaging device has a focus drive unit that advances and retracts the focus lens holding frame, and has an axis along the optical axis direction of the imaging lens, A lead screw that is rotationally driven by a drive motor; a nut that is screwed to the lead screw and has a rotation-preventing protrusion; and a guide groove into which the protrusion is slidably fitted. When the lead screw is driven to rotate during focus driving, the holding frame is driven back and forth in the direction of the photographic lens optical axis while being pressed by the nut. Note that Patent Document 1 is disclosed as a mechanism similar to the conventional lens frame advance / retreat mechanism.

  In addition, in the image blur correction apparatus A1 disclosed in Patent Document 2 as an application of a drive mechanism that applies a lead screw, the driving force of the first motor 15 is the first as shown in FIGS. The binion 16 is rotated. The first pinion 16 rotates the first lead screw 18 via the first gear 17. At this time, the first nut 19 screwed into the first lead screw 18 is rotated by its rotation restricting portion 19a being engaged with the engagement portion 11p (see FIG. 23) on the base 10 side. Is regulated. Therefore, as the first lead screw 18 rotates, the first nut 19 moves in a direction (first direction) along the arrow Y in FIG.

  The first engaging portion 11c of the first moving frame 11 is in contact with the first nut 19, and the contact state between the two is always maintained by the urging force of the first urging spring (FIG. 22). reference). That is, the urging force of the first urging spring 13 urges the first moving frame 11 in the Y direction with respect to the base 10, so that the first engaging portion 11 c is on the upper surface side of the first nut 19. The state of being in constant contact with the (outer surface) is maintained. In this state, the drive control of the first motor 15 is performed as described above, and, for example, when the first nut 19 moves in the direction of the arrow Y1 in FIG. The first engagement portion 11c and the first nut 19 are maintained in contact with each other by the urging force of the spring 13, and move in the same direction (arrow Y1 direction). Further, for example, when the first nut 19 moves in the direction opposite to the arrow Y1 direction in FIG. 3, the first nut 19 resists the biasing force of the first biasing spring 13 and the first engagement portion. This is pressed while contacting 11c. Accordingly, the first moving frame 11 moves in the same direction (the direction opposite to the arrow Y1 direction).

JP 2000-206391 A JP 2008-048220 A

  In the case of the focus drive unit of the conventional imaging apparatus, a fitting backlash is indispensable between the guide groove and the protruding portion of the nut, and when the focus lens holding frame is driven forward and backward, the fitting backlash is used. The collision between the protrusion and the guide groove is repeated, and noise generation is unavoidable.

  The present invention has been made to solve the above-described problems, and provides an imaging apparatus including a drive mechanism such as a lens frame advance / retreat mechanism or a shake correction drive mechanism with less noise during driving operation. With the goal.

  In order to solve the above problems, a lens barrel of the present invention includes a fixed frame, a photographing optical system having a focus lens group having an imaging lens optical axis, a focus lens holding frame for holding the focus lens group, and the fixed lens. A focus drive unit including a focus motor and a rotation transmission mechanism provided on the outer periphery of the frame for performing focus drive of the focus lens group, and the rotation transmission mechanism is in the optical axis direction of the imaging lens A lead screw that is rotationally driven by the focus motor and drives the focus lens holding frame forward and backward, and is screwed into the lead screw, and is arranged facing the optical axis direction, A pair of nuts with protrusions, and the protrusions provided on the fixed frame to restrict rotation of the pair of nuts The pair of nuts arranged between the guide groove portion slidably fitted in the optical axis direction of the imaging lens and the pair of nuts, urging the pair of nuts away from each other, and the pair of nuts And an urging member for urging them in the rotational directions opposite to each other.

  An imaging apparatus of the present invention includes a fixed frame, a photographing optical system having a focus lens group having an imaging lens optical axis, an imaging element that receives an optical image formed through the photographing optical system and generates image data, A base member coupled to the fixed frame and supporting the image sensor so as to be displaceable in a first direction and a second direction orthogonal to the first direction within a plane parallel to the light receiving surface of the image sensor; A first motor that is disposed on the base member and that drives the imaging device in the first direction and includes a first rotation transmission mechanism, and a second motor that drives in the second direction And a second drive unit including a second rotation transmission mechanism, the first rotation transmission mechanism and the second rotation transmission mechanism are rotationally driven by the first motor and the second motor, The image sensor is arranged in a first direction and a second direction A lead screw that is displaced in a direction, a pair of nuts that are screwed into the lead screw and provided with a protrusion, and the base member into which the protrusion is slidably fitted to restrict rotation of the nut The guide groove provided in the guide and the pair of nuts are urged to urge the nuts in a direction away from each other and urge the pair of nuts in opposite directions of rotation. And a member.

  The present invention can provide a lens barrel and an imaging apparatus that include a drive mechanism that generates less noise during a driving operation.

1 is an exploded perspective view showing a part of a lens barrel in an imaging apparatus according to an embodiment of the present invention. It is a disassembled perspective view which shows the other part of the lens-barrel of FIG. 1 and 2 are exploded perspective views of the third group frame and the shutter unit in the lens barrel of FIGS. 1 and 2 are exploded perspective views of the fixed frame, the fourth group frame, and the focus drive unit in the lens barrel of FIGS. FIG. 4 is an exploded exploded perspective view of the focus drive unit of FIG. FIG. 4 is an assembled perspective view of a lead screw, a nut, and an urging spring incorporated in the focus drive unit of FIG. 1 and 2 are perspective views of a blur correction imaging unit in the lens barrel of FIGS. 1 and 2 are longitudinal sectional views including the lens optical axis in the retracted state of the lens barrel of FIGS. 1 and 2 is a longitudinal sectional view including the lens optical axis in the wide state in which the lens barrel of FIGS. 1 and 2 is a longitudinal sectional view including the lens optical axis in a telephoto state where the lens barrel of FIGS. 1 and 2 are cross-sectional views including the lens optical axis in the retracted state of the lens barrel of FIGS. Front view of the lens barrel of FIGS. Rear view of the lens barrel of FIGS. FIG. 9 is a cross-sectional view taken along the line XIV-XIV in FIG. 1 and 2 in a retracted state of the lens barrel of FIGS. The bottom view of the lens barrel of FIGS. The right side view of the lens barrel of FIGS. The left side view of the lens barrel of FIGS. FIG. 2 is a partial cross-sectional view of the lens barrel of FIGS. 1 and 2 viewed from the left in a retracted state, particularly showing a cross-section of a focus drive unit 1 and 2 are exploded perspective views of a lead screw, a nut, and an urging spring as modifications of the first and second rotation transmission mechanisms in the X and Y drive units of the lens barrel of FIGS. The disassembled perspective view of the conventional image blur correction apparatus. The front view which shows the state which assembled the image blurring correction apparatus of FIG. FIG. 23 is a cross-sectional view of the main part as seen from the direction of arrow A in FIG. 22.

  A lens barrel serving as an imaging apparatus according to an embodiment of the present invention will be described with reference to FIGS.

  The lens barrel 1 of the present embodiment includes a photographing optical system having a first group lens having a positive refractive power, a second group lens having a negative refractive power, a third group lens having a positive refractive power, and a fourth group lens having a positive refractive power. A retractable lens barrel in which each movable lens barrel member is retracted in a non-photographing state, and further has an image blur correction function including an image sensor that can move to the imaging plane of the optical system It can be built in a digital camera as an imaging device.

  In the following description, the photographic lens optical axis of the imaging optical system is indicated by “O”. Among the optical axis O directions, the subject side direction is defined as the front, and the imaging side direction is defined as the rear. Further, the direction that is orthogonal to the optical axis O and viewed from the front side is the X direction that is the first direction, and the right direction is the + X side. A direction (vertical direction) perpendicular to the optical axis O and the X direction is a second direction, the Y direction, and in particular, the upward direction is the + Y side. A plane orthogonal to the optical axis O is defined as an XY plane.

  When the lens barrel 1 is in the retracted state, as shown in FIG. 8, each movable frame member is retracted to the fixed frame 13 side, which will be described later, so that they are close to each other, and the entire length of the lens barrel is shortened. It is in the state that was done. On the other hand, when the lens barrel 1 is in a zoom wide state and a zoom telephoto state where photographing is possible, as shown in FIGS. 9 and 10, each movable frame member is extended forward in the optical axis O direction, and a group frame 4 described later. Then, the cam frame 5, the rotating frame 11 and the like are in a protruding state. Further, in the lens barrel 1, an imaging device 96 described later is supported so as to be movable on an XY plane orthogonal to the optical axis O, and based on a camera shake detection signal detected on the digital camera side during shooting, The image sensor 96 is displacement controlled on the XY plane so as to correct the camera shake.

  1 and 2, the main constituent members of the lens barrel 1 are sequentially arranged from the front side in the optical axis O direction, and include a barrier unit 3 for opening and closing a front surface portion of a group lens 21 described later, and a group. A first group frame 4 that is a zoom lens holding frame that holds the lens 21, a second group frame 6 that is a zoom lens holding frame that holds the second group lens 22, and a cam frame for driving the first group frame 4 and the second group frame 6 to advance and retreat. 5, a shutter / aperture unit 8 on the rear side, a third group frame 7 that is a zoom lens holding frame for holding the third group lens 23, and a frame member for restricting the rotation of the first and second group frames. The float key 9 and the cam frame 5 are driven forward / backward, the movable frame 10 for restricting the rotation of the third group frame 7 and the float key 9, the cam frame 5 is driven to rotate, and the third group frame 7 is Rotating frame 11 for advancing and retreating driving, and fourth group lens 24 A fixed frame member for supporting the fourth group frame 12 that is a focus lens holding frame to be held and the rotary frame 11 so that the rotary frame 11 can be rotated forward and backward and for restricting the rotation of the movable frame 10. A frame 13, a zoom drive unit 50 that rotationally drives the rotary frame 11, a focus drive unit 60 that drives the fourth group frame 12 to advance and retreat, and a base plate 14 that is a base member, and holds an image sensor 96. A blur correction imaging unit 90 is provided for driving the imaging element 96 to move on a plane orthogonal to the optical axis O direction.

  The fixed frame 13 has a cylindrical portion, accommodates each frame member in the inner peripheral portion, and the base plate 14 of the shake correction imaging unit 90 is fixed to the back surface portion. The fixed frame 13 includes a rotating frame cam groove 13a that is inclined with respect to the direction of the optical axis O along the inner periphery of the cylinder, a linear guide groove 13c for a moving frame along the direction of the optical axis O, and a fourth group frame. A rectilinear guide groove 13b and a nut guide groove 13e (FIG. 14) and a gear housing recess 13d in which a long gear 54 described later is housed are provided. In addition, a zoom drive unit 50 is disposed along the right side of the outer periphery of the cylinder, and a focus drive unit 60 is disposed on the upper left of the outer periphery of the cylinder. A light shielding ring 35 is fixed to the front surface portion.

  The rotating frame 11 is a cylindrical frame member, and is inserted into the inner peripheral portion of the fixed frame 13 so that the outer periphery of the rear end portion can rotate and retreat. A cam follower 11 b is arranged on the outer periphery of the rear end portion, and is slidably fitted into the cam groove 13 a of the fixed frame 13. A gear portion 11 a that meshes with the long gear 54 is provided in a predetermined range on the outer periphery of the rear end portion. A third group frame cam groove 11c and a cam frame rectilinear groove 11d which are inclined with respect to the optical axis O direction are provided on the inner peripheral portion of the rotary frame 11.

  When the rotary frame 11 is rotationally driven by the rotation of a long gear driven by the zoom drive unit 50, the rotary frame 11 is driven to advance and retreat in the optical axis O direction while rotating along the cam groove 13a. A light shielding ring 34 and a decorative ring 33 are mounted on the outer periphery of the front surface of the rotary frame 11.

  The moving frame 10 is a cylindrical frame member, the rear end portion of which is bayonet-coupled to the rotating frame 11, is moved forward and backward in the optical axis O direction with respect to the rotating frame 11, and is supported so as to be relatively rotatable. Has been. Further, a guide pin 10 b that protrudes to the outer periphery of the rear end portion is engaged with the rectilinear guide groove 13 c of the fixed frame 13. Therefore, the moving frame 10 advances and retreats together with the rotating frame 11 under the rotation restricted state.

  A cam frame cam groove 10c that penetrates the inner and outer peripheries of the movable frame 10 and obliquely moves with respect to the optical axis O, a third group frame rectilinear guide groove 10e that penetrates the inner and outer peripheries, and an inner peripheral portion Is provided with a straight guide groove 10f for a float key.

  The float key 9 is a cylindrical frame member, the rear end portion of the cam frame 5 is bayonet-coupled, moves forward and backward in the direction of the optical axis O with respect to the cam frame 5, and is relatively rotatable. It is supported by. The float key 9 is provided with a guide projection 9a projecting to the outer periphery of the rear end portion, a first-group frame rectilinear guide groove 9c on the outer peripheral portion, and a second-group frame rectilinear guide groove 9b penetrating the inner and outer peripheries.

  The guide protrusion 9 a of the float key 9 is slidably fitted into the straight guide groove 10 f of the moving frame 10. Accordingly, the float key 9 is supported so as to be movable back and forth in the direction of the optical axis O together with the cam frame 5 under a state in which the rotation is restricted by the moving frame 10.

  The cam frame 5 is a cylindrical frame member that is fitted into the inner peripheral portion of the moving frame 10 and is incorporated so as to be capable of rotating forward and backward. The cam frame 5 is provided with a cam follower 5d that protrudes from the rear outer peripheral portion, and is fitted and fixed to the center of the cam follower 5d in a state in which the linear guide pin 38 protrudes outward. The inner peripheral portion is provided with three pairs of one-group frame cam grooves 5a, sub-cam grooves 5b, and three second-group frame cam grooves 5c having the same cam curve (cam groove center locus).

  Cam followers 36 and 37 of the first group frame 4, which will be described later, are fitted in the first group frame cam groove 5a and the sub cam groove 5b, respectively, and the cam groove 5a side functions as an advance / retreat drive for the first group frame 4, but the sub cam groove 5b side Serves to prevent the cam follower from coming off when an external force in the thrust direction is applied to the group frame 4 due to an impact or the like.

  The cam groove 5c for the second group frame is composed of cam grooves having different groove widths, and when the lens barrel 1 is in a wide state from the telephoto state to the tele state, a cam follower 39 of the second group frame 6 to be described later is formed on the cam groove 5c. Of these, when fitted into a cam groove without a gap and in a retracted state, the cam groove 5c is fitted into a cam groove with a gap. This prevents a clogged state between the first group frame 4 and the second group frame 5 when the lens barrel 1 is in the retracted state.

  The cam follower 5d is slidably fitted into the cam groove 10c of the moving frame 10, and the rectilinear guide pin 38 is slidably fitted into the rectilinear groove 11d of the rotating frame 11 after being inserted through the cam groove 10c (FIG. 11). . Therefore, the cam frame 5 is supported so as to be movable back and forth in the direction of the optical axis O along the cam groove 10 c of the moving frame 10 while rotating together with the rotating frame 11.

  When the cam frame 5 is extended together with the rotating frame 11 in the telephoto state as shown in FIG. 10, the cam follower 5 d is located near the thin portion 10 d on the front side of the cam groove 10 c of the moving frame 10. It is moving (Fig. 1). If an external force (tensile force) in the forward direction is applied to the group frame 4 exposed to the outside or the cam frame 5 in this state, a thin-walled portion on the front side of the movable frame 10 via the cam follower 5d. There is a possibility that the external force acts on 10d to break the thin portion 10d. However, in the present embodiment, since the front end surface of the moving frame 10 is in contact with the inner step portion 11e (FIG. 10) of the rotating frame 11 due to the forward external force, the thin wall of the moving frame 10 due to the external force is used. Damage to the portion 10d is prevented.

  The barrier unit 3 incorporates four barrier blades 3 a and is attached to the front portion of the group frame 4 while being covered with the decorative ring 2. As the first group frame 4 is retracted from the retracted position, the barrier blade 3a is retracted, and the front surface of the first group lens 21 is opened. Further, as the first group frame 4 is retracted from the photographing position, the barrier blade 3a is advanced to the closed position, and the front surface of the first group lens 21 is closed.

  The first group frame 4 is a cylindrical frame member and is fitted in the inner peripheral portion of the cam frame 5 so as to be able to advance and retreat in a rotation restricted state. The first group frame 4 holds a first group lens 21 which is a zoom lens group, and three pairs of cam followers 36 and 37 are fixed to the outer peripheral portion. Further, a guide protrusion (not shown) that is slidably fitted in the straight guide groove 9c of the float key 9 is provided on the inner peripheral portion.

  The cam followers 36 and 37 of the first group frame 4 are slidably fitted into the cam groove 5a and the sub cam groove 5b of the cam frame 5, respectively, and the first group frame 4 is restricted in rotation by the rectilinear guide groove 9c of the float key 9. In this state, the cam frame 5 moves forward and backward as the cam frame 5 rotates and advances and retracts. Note that the cam follower 37 and the sub cam groove 5b are provided to prevent the cam follower from coming off when an external force due to dropping or the like acts on the group frame 4 as described above.

  The second group frame 6 is a cylindrical frame member. The second group frame 6 is fitted into the inner peripheral portion of the float key 9 so as to be able to advance and retreat in a rotation restricted state, and is incorporated on the rear side of the first group frame 4. The second group frame 6 holds a second group lens 22 which is a zoom lens group, and has three guide projections 6a on the outer peripheral portion, and a cam follower 39 protruding outward from the center of the guide projection 6a. It is fixed.

  The guide protrusion 6 a is fitted into the straight guide groove 9 b of the float key 9 and penetrates therethrough, and the cam follower 39 is fitted into the cam groove 5 c of the cam frame 5. Therefore, the second group frame 6 moves forward and backward under the rotation restricted state by the rotation and forward / backward movement of the cam frame 5.

  The third group frame 7 is a cylindrical frame member, is fitted into the inner peripheral portion of the float key 9, and is incorporated behind the second group frame 6 so as to be able to advance and retreat in a rotation restricted state. The third group frame 7 holds a third group lens 23 which is a zoom lens group, and supports a shutter / aperture unit 8 on the inner peripheral portion on the back side so as to be movable relative to the optical axis O direction. Further, a third group lens pressing plate 7a is fixed to the front side. A guide protrusion 7b is provided on an arm portion protruding outward from the third group frame 7, and a cam follower 41 is fixed to the guide protrusion (FIG. 3).

  The third group frame 7 is assembled by fitting the guide protrusion 7b into the rectilinear guide groove 10e of the moving frame 10 and inserting the cam follower 41 into the cam groove 11c of the rotating frame 11 after passing through. Accordingly, the third group frame 7 moves back and forth in the direction of the optical axis O under the rotation restricted state as the rotating frame 11 rotates.

  The shutter / aperture unit 8 incorporates a shutter blade 25 for opening and closing a photographing optical path and a diaphragm blade 26 for adjusting a photographing light amount. A compression spring 42 is inserted between the shutter / diaphragm unit 8 and the third group frame 7 and is urged away from each other.

  When the lens barrel 1 is ready for photographing, the shutter / aperture unit 8 and the third group frame 7 are separated from each other by a predetermined distance. However, in the retracted state, the compression spring 42 is compressed by the fourth group frame 12 and is substantially in close contact with each other. It becomes a state to do. In the retracted state, the shutter blade 25 and the diaphragm blade 26 are driven to the open position, and the rear portion of the third lens group 23 enters the open opening. As a result, a state closer to the close contact between the shutter / diaphragm unit 8 and the third group frame 7 is obtained. Furthermore, it is in a state of being very close to the fourth group lens 24.

  Between the second group frame 6 and the third group frame 7, a conical coil spring 18 as an urging member for urging the second and third group frames is inserted, and the second group frame 6 and the third group frame 7 are optically connected to each other. It is urged so as to be separated in the O direction (FIGS. 8 to 10). Since the second group frame 6 and the third group frame 7 are urged away from each other as described above, the cam follower of the second group frame 6 can be used when the lens barrel 1 is in a state where it can be photographed including the retracted state. 39, the cam groove 5c of the cam frame 5, the cam follower 41 of the third group frame 7, and the cam groove 11c of the rotary frame 11 are each fitted together, and the second group frame 6 in the state where there is no play in the optical axis O direction. And the third group frame 7 can be moved forward and backward.

  In addition, the conical coil spring 18 is provided with a bent portion 18a that is bent to the inner diameter side at the large-diameter side end winding portion. When assembled between the second group frame 6 and the third group frame 7, the large-diameter side winding portion is disposed against the end surface side of the second group frame 6. When the lens barrel 1 is retracted into the retracted state, the conical coil spring 18 is compressed and close to the close contact state as shown in FIG. A state in which the winding adjacent to the winding portion is fitted and not restored is prevented.

  The fourth group frame 12 is disposed behind the shutter / aperture unit 8 so as to be able to advance and retreat in a rotation restricted state. The fourth group frame 12 holds a fourth group lens 24, which is a focus lens group, in a central opening, and has two arms extending outward. The one arm portion is provided with a guide protrusion 12c, and the other arm portion is provided with a guide shaft hole 12a, a lead screw insertion hole 12b, and a sensor shielding piece portion 12d.

  A guide shaft 65 supported by the fixed frame 13 is slidably fitted into the guide shaft hole 12a. The guide protrusion 12 c is formed to protrude in both widths (circumferential direction) around the optical axis O, and includes two micro cylindrical portions extending in the direction parallel to the optical axis O. Fits movably. Accordingly, the fourth group frame 12 is supported by the driving force of the focus driving unit 60 described later via the lead screw 66 so as to be able to advance and retract in the optical axis O direction along the guide shaft 65 and the rectilinear guide groove 13b.

  The guide protrusion 12c is composed of two minute partial cylindrical portions in the width direction as described above. Accordingly, even if there is a slight misalignment around the optical axis O due to the dimensional accuracy of the fourth group frame 12, both cylindrical widths of the guide protrusions 12c abut against the rectilinear guide groove 13b of the fixed frame 13, so A good fitting state without any problem is maintained.

  In addition, when the center adjustment mechanism of the fourth group lens 24 is applied to the fourth group frame 12 and, for example, the eccentric adjustment mechanism is incorporated in the guide shaft 65, the guide protrusion 12c is a minute partial cylindrical portion as described above. If formed, it is possible to maintain a good fitting state between the straight guide groove 13b and the guide protrusion 12c even when the posture of the fourth group frame 12 is changed by the core adjustment. The guide protrusion 12c is not limited to the minute cylindrical portion, and may be two minute spherical portions that protrude in the width direction.

  As shown in FIGS. 2 and 14, the zoom drive unit 50 is arranged on the right side (on the left side in FIG. 14) of the cylindrical outer periphery of the fixed frame 13, and includes a zoom motor 51 composed of a DC motor, a gear case lid 52, and a gear train. 53 and a long gear 54.

  The gear case lid 52 is fixed to the right side of the fixed frame 13 from the back side, and includes a shaft hole portion that supports the shaft portions of the gear train 53 and the long gear 54.

  The zoom motor 51 is supported by the fixed frame 13 and is disposed between an X drive motor 71 and a Y drive motor 81, which will be described later, mounted on the base plate 14, and a worm gear is provided on the output shaft along the Y direction. It is fixed.

  The gear train 53 includes a worm wheel that meshes with the worm gear of the zoom motor 51 and a reduction gear train that meshes with the worm wheel and meshes with the long gear 54.

  The long gear 54 is housed in the gear housing recess 13 d of the fixed frame 13 along the direction parallel to the optical axis O, and meshes with the gear portion 11 a of the rotating frame 11.

  In the zoom drive unit 50, when the zoom motor 51 is rotationally driven during the retracting drive and zoom driving of the lens barrel 1, the rotary frame 11 is rotationally driven via the long gear 54, and the lens barrel 1 is extended or retracted. Is done.

  As described above, the focus drive unit 60 is disposed at the upper left of the outer peripheral portion of the cylinder. As shown in FIGS. 4 to 6, 14, and 19, the focus motor 61 including a step motor, a gear case lid 62, and a rotation transmission mechanism 59 are provided. As a guide shaft 65, a gear train 63, a lead screw 66, a pair of nuts 64A and 64B, a torsion spring 69 which is a biasing member for biasing the nut, a fourth group frame biasing spring 67, and a photo interrupter. It comprises a focus origin detection PI 68 which is an origin detector.

  The gear case lid 62 is fixed to the upper left part of the fixed frame 13 from the back side, and supports the guide shaft 65 and the shaft end of the lead screw 66 parallel to the optical axis O.

  The focus motor 61 is supported by the fixed frame 13, and a pinion that meshes with the gear train 63 is attached to an output shaft along a direction parallel to the optical axis O.

  The guide shaft 65 is arranged along a direction parallel to the optical axis O, is slidably fitted into the guide shaft hole 12a of the fourth group frame 12, and its shaft end is supported by the fixed frame 13 and the gear case lid 62. The

  The lead screw 66 is driven by a focus motor 61 through a gear train 63. A pair of nuts 64 </ b> A and 64 </ b> B with a torsion spring 69 interposed are screwed into the lead screw 66.

  The fourth group frame urging spring 67 is formed of a tension spring, is suspended between the fixed frame 13 and the fourth group frame 12, urges the fourth group frame 12 forward, and the fourth group frame is biased to one nut 64A of a pair of nuts. The end surface portion of the lead screw insertion hole 12b of the frame 12 is brought into contact.

  A pair of nuts 64A and nuts 64B have the same shape, and are formed in a female screw part 64a screwed into the lead screw 66 and a guide groove 13e (FIG. 14) along the optical axis O direction of the fixed frame 13. A rotation restricting protrusion 64b that is slidably fitted, and convex portions 64c and 64d provided on the front and rear surfaces of the rotation restricting protrusion 64b in the optical axis O direction are provided.

  The torsion spring 69 has a coil spring shape, is interposed between the nut 64A and the nut 64B, is inserted into the lead screw 66 in a compressed state in the direction of the optical axis O, and further, the spring hook portions 69a and 69b are respectively connected to the nuts. It hangs on the convex part 64d of 64A and the convex part 64c of the nut 64B, and is assembled in a state in which both are separated.

  The nut 64A and the nut 64B are urged by the torsion spring 69 in opposite directions of rotation and are urged and held in directions away from each other in the optical axis O direction. Accordingly, the nut 64A and the nut 64B are configured so that the rotation restricting projection 64b does not cause a backlash in the rotational direction with respect to the guide groove 13e of the fixed frame 13 when the lead screw 66 is stopped or rotated. It is slidably supported in the O direction.

  It is desirable that the biasing force of the nut 64 </ b> A and the nut 64 </ b> B of the torsion spring 69 that is separated in the direction of the optical axis O has a large difference in the amount of force with respect to the forward biasing force by the fourth group frame biasing spring 67. This is because there is no occurrence of positional deviation of the fourth group frame 12 in the optical axis O direction, and the correct position is always maintained. In addition, the biasing force of the torsion spring 69 in the direction of the optical axis O is preferably as small as possible because of the rotational load of the lead screw 66.

  The PI 68 is fixed to the fixed frame 13 so that the sensor shielding piece 12d of the fourth group frame 12 can be inserted therethrough. When the camera is turned on, the PI 68 detects passage of the sensor shielding piece 12d of the fourth group frame 12 and the focus origin position information of the fourth group frame 12 is taken into a camera control unit (not shown).

  Note that the rear end portion of the focus drive unit 60 including the gear case lid 62 protrudes rearward from the back surface of the fixed frame 13, and the protruding portion is the upper left on the base plate 14 of the shake correction imaging unit 90 described later. It has entered a notch provided in the third corner 14d of the corner.

  In the focus drive unit 60, when the focus motor 61 is rotationally driven during the focusing drive of the lens barrel 1, the lead screw 66 is rotationally driven, and the pair of nuts 64A and 64B move forward and backward. The fourth group frame 12 moves forward and backward in the direction of the optical axis O in a state where the end surface of the lead screw insertion hole 12b is in contact with the rear end surface of the nut 64A. Further, the rotation restricting protrusions 64b of the nuts 64A and 64B as a pair are slidably fitted into the guide groove 13e of the fixed frame 13 without any backlash.

  Here, the first, second, third, and fourth group lenses constituting the photographing optical system of the lens barrel 1 will be described. The first group lens 21 includes a negative meniscus lens 21a having a convex surface facing the subject side in order from the subject side and a biconvex shape. It consists of a cemented lens of the positive lens 21b, and moves to the subject side from the wide end to the tele end. By applying the first group lens 21, it is advantageous for downsizing in the thickness direction and the radial direction, and each lens cancels out aberrations, which is advantageous for correction of various aberrations in the first group lens 21, widening, Aberration fluctuation when the zoom ratio is increased is suppressed.

  The second group lens 22 includes a second group lens front group 22a and second group lens rear groups 22b and 22c in order from the subject side. The second lens group front group 22a is composed of a negative meniscus lens having a convex surface facing the subject, and the second lens group rear groups 22b and 22c are composed of a biconcave negative lens and a positive meniscus lens having a convex surface facing the object. .

  The second group lens 22 is moved from the wide end to the intermediate state with the first group lens 21 and moved toward the image plane while narrowing the distance with the third group lens 23. From the intermediate state to the tele end, Is moved to the subject side while the distance from the third lens group 23 is narrowed. At the tele end, it is located closer to the subject than at the wide end.

  The third group lens 23 includes a third group lens front group 23a and a third group lens rear group 23b in order from the subject side. The third lens group 23a is composed of a biconvex positive lens, and the third lens group rear group 23b is composed of a negative meniscus lens having a convex surface facing the subject. The third group lens 23 moves toward the subject from the wide end to the tele end.

  The fourth group lens 24 is composed of one positive meniscus lens having a convex surface facing the subject side. The fourth group lens 24 is driven back and forth during focusing, and further moves from the wide end to the intermediate state toward the subject side while widening the distance from the third group lens 23, and from the intermediate state to the tele end, Move slightly to the image plane side while widening the interval. At the tele end, it is located closer to the subject than at the wide end.

  By composing the photographing optical system as described above, the combined system of the first group lens 21 and the second group lens 22 approaching in the vicinity of the wide end has a positive refractive power (first group lens 21) and a negative refractive power (in order from the subject side). The second lens group front group 22a) and the positive refracting power (second lens group rear groups 22b and 22c) have a symmetrical power arrangement.

  Also in the composite system of the third group lens 23 and the fourth group lens 24, in order from the subject side, positive refractive power (third group lens front group 23a), negative refractive power (third group lens rear group 23b), positive refractive power ( The symmetric power arrangement of the fourth group lens 24) is obtained.

  In addition, the composite system of the second group lens 22 and the third group lens 23 that are close to each other near the telephoto end has a negative refractive power (second group lens front group 22a) and a positive refractive power (second group lens rear group 22b) in order from the subject side. 22c), a positive refracting power (the third lens group front group 23a), and a negative refracting power (the third lens group rear group 23b).

  Therefore, it is easy to correct Petzval sum, coma aberration, lateral chromatic aberration, and spherical aberration near the wide end, and Petzval sum, coma aberration, and lateral chromatic aberration near the tele end. It becomes easy to do. In addition, the principal point of the third lens group can be more easily set than the subject, and the zoom ratio can be easily secured.

  Furthermore, the fourth group lens 24 is made up of a single positive lens component, which is advantageous in reducing the thickness when the lens barrel is retracted. Since the fourth group lens 24 mainly has a function of separating the exit pupil from the image plane, the positive refractive power can be reduced. Therefore, the above-described configuration is advantageous in reducing the size and cost.

  The blur correction imaging unit 90 includes a movable imaging unit mounted on the back surface of the fixed frame 13, and a base plate 14 that is a base member and a Y supported on the base plate 14 so as to be movable in the Y direction of the XY plane. A frame 15, an X frame 16 supported on the Y frame 15 so as to be movable in the X direction of the XY plane, an image sensor unit 95 fixedly supported on the X frame 16, and an X drive unit as a first drive unit 70 and a Y drive unit 80 as a second drive unit.

  The base plate 14 has a central opening 14a, and a schematic projection shape seen from the front is centered on the optical axis O, and a lower right (lower left in FIG. 13) first corner 14b and an upper right (in FIG. 13). A frame member having a substantially rectangular shape having a second corner portion 14c at the upper left, a third corner portion 14d at the upper left (upper right in FIG. 13), and a fourth corner 14e at the lower left (lower right in FIG. 13). Thus, it is fixed to the back surface of the fixed frame 13. When the base plate 14 is fixed to the fixed frame 13, it is necessary to accurately position the shake correction imaging unit 90 on the XY plane with respect to the optical axis O on the lens barrel side. Both positioning holes 14f and 14g (FIG. 13) are fixed in a state where the positioning holes 14f and 14g (FIG. 13) are fitted into the positioning pins on the fixed frame 13 side.

  The third corner 14d has a notch, and the rear end of the focus drive unit 60 including the gear case lid 62 enters the notch as described above. The fourth corner portion 14 e is a member arrangement relief portion in a state along the outer periphery of the fixed frame 13. The escape portion serves as an escape portion for arranging a tripod female screw portion of the digital camera to which the lens barrel 1 is attached.

  The Y frame 15 is made of a frame member having an opening 15a, and is arranged in the central opening 14a of the base plate 14, and is biased by a biasing spring in the Y direction by two guide shafts 91 and 92. It is slidably supported.

  The X frame 16 is made of a frame member having an opening 16a, is arranged in the opening 15a of the Y frame 15, and is slid in the X direction by two guide shafts 93 and 94 while being urged by an urging spring. It is supported movably.

  The image sensor unit 95 is fixed to the image sensor support plate 98 while being mounted on an image sensor support plate 98 and an FPC (flexible printed circuit board) 103, and includes an image sensor 96 made of CCD, CMOS, or the like, and an image sensor. 96, an optical low-pass filter disposed on the front side of 96 or an optical filter 97 of an infrared cut absorption filter. A near-infrared sharp cut coat may be directly coated on the surface of the optical low-pass filter.

  The image sensor unit 95 is attached to the X frame 16 with the image sensor support plate 98 fixed to the back side of the X frame 16 with screws, and the image sensor 96 and the optical filter 97 arranged in the opening 16 a of the X frame 16. The

  The X drive unit 70 is assembled to the front side of the upper right first corner 14b of the base plate 14, and is arranged in a state of overlapping the rear position of the gear train 53 of the zoom drive unit 50 on the outer peripheral portion of the fixed frame 13 ( FIG. 12). The X drive unit 70 includes an X drive unit support plate 72, an X drive motor 71 as a first motor composed of a step motor, and a pinion of an output shaft of the X drive motor 71 as a first rotation transmission mechanism 77. The intermediate gear 73 and the intermediate gear 73 meshing with each other are fixed, and include a lead screw 74 and a nut 75 along the X direction, and a PI (photo interrupter) 76 which is an X frame initial position detection sensor. Instead of the position detector of PI76, it is also possible to arrange a position detector that performs initial position detection by a combination of a photo reflector or a Hall element and a flat permanent magnet.

  The nut 75 is screwed into the lead screw 74 under the rotation restriction state with respect to the X frame 16, and the protruding portion 75 b of the nut is inserted into the guide groove 14 h in the X direction provided in the base plate 14. It is supported so as to be slidable in a rotation restricted state, and is in contact with the U-shaped notch 16b of the X frame 16 under the biasing force of the biasing spring. Accordingly, when the X drive motor 71 is rotationally driven during the shake correction operation, the nut 75 and the X frame 16 are driven to be displaced in the X direction by the lead screw 74.

  The Y drive unit 80 is assembled on the front surface side of the second corner portion 14 c of the base plate 14 and is disposed above the zoom motor 51 on the outer peripheral portion of the fixed frame 13. The Y drive unit 80 includes a Y drive unit support plate 82, a Y drive motor 81 as a second motor composed of a step motor, and a pinion of an output shaft of the Y drive motor 81 as a second rotation transmission mechanism 87. The meshing intermediate gear 83 and the intermediate gear 83 are fixed, and are composed of a lead screw 84 and a nut 85 along the Y direction, and a PI (photo interrupter) 86 that is a Y frame initial position detection sensor.

  The nut 85 is threadedly engaged with the lead screw 84 under the rotation restriction state with respect to the Y frame 15, and is in a rotation restriction state in which the nut protrusion is fitted in a guide groove in the Y direction provided on the base plate 14. It is supported so as to be slidable, and is in contact with the U-shaped notch 15b of the Y frame 15 under the urging force of the urging spring. Therefore, when the Y drive motor 81 is rotationally driven during the blur correction operation, the nut 85 and the Y frame 15 are displaced and driven in the Y direction by the lead screw 84.

  In the shake correction imaging unit 90, during the image sensor exposure operation by camera shake correction, the Y frame 15 and the X frame 16 are driven to be displaced on the XY plane according to camera shake. Immediately after the power switch of the digital camera is turned on, the Y frame 15 and the X frame 16 are respectively returned to the initial intermediate positions based on the output signals of I86 and PI76. In the state where the Y frame 15 and the X frame 16 are at the initial intermediate position, the center position of the light receiving surface of the image sensor 96 coincides with the optical axis O.

  In the shake correction imaging unit 90, the arrangement of the X drive unit 70 and the Y drive unit 80 with respect to the base plate 14 is turned upside down with respect to the above-described arrangement, and the X drive unit 70 is moved to the first corner 14b. It is also possible to arrange the Y drive unit 80 at the second corner 14c.

  In the lens barrel 1 described above, the exterior color of the zoom motor 51, the focus motor 61, the Y drive motor 81, and the X drive motor 71 is black or other than black, for example, silver, and the fixed frame 13 and The exterior color of the base plate 14 is a color other than black, for example, silver or black. Thus, for example, each motor of the zoom motor 51, the focus motor 61, the Y drive motor 81, and the X drive motor 71 in a state in which the assembly state during the assembly process is confirmed by making the exterior color of the component member and the motor different. The base plate 14 can be fixed to the fixed frame 13 by confirming that the fixed frame 13 and the base plate 14 are mounted at the predetermined positions.

  Next, the arrangement of an FPC (flexible printed circuit board) for electrical connection between the electrical control elements of the constituent units of the lens barrel 1 and the control unit of the digital camera will be described with reference to FIGS. .

  The FPC for electrical connection provided in the lens barrel 1 is an FPC 101 for electrical connection between the zoom and focus drive units 50 and 60, the shutter / aperture control unit 8 and the camera-side electrical control unit, and X and Y drive. The unit includes an FPC 102 for electrical connection between the units 70 and 80 and the camera-side electrical control unit, and an FPC 103 for electrical connection between the image sensor unit 95 and the camera-side electrical control unit.

  The FPC 101 includes a zoom motor connector 101a, a focus motor connector 101b, a focus position detection PI connector 101f, a connection extension 101c to the focus motor connector, a left extension 101d, A control connector 101g, a shutter / aperture control unit FPC connector 101e, and a zoom position detection PI connector and a PR connector are also provided (FIG. 2).

  In the FPC 101, as shown in FIG. 12, a zoom motor connector portion 101 a disposed at one end is connected to a terminal portion of the zoom motor 51. Further, the focus motor connector portion 101b branched from the connecting extension portion 101c in the middle of the left extension portion 101d of the FPC 101 extending leftward along the upper outer peripheral portion of the fixed frame 13 is the focus motor 61. Connected to the terminal portion of The left extending portion 101d is connected to the PI 68 at a PI connector portion 101f that branches rearward after being inserted through the upper outer periphery of the fixed frame 13. Further, after passing through the upper outer periphery of the fixed frame 13, the branched shutter / aperture control unit FPC connector portion 101e is connected to a shutter / aperture control unit FPC (not shown). The FPC 101 is connected to a camera electrical control unit (not shown) with a camera electrical control connector portion 101g extending leftward after passing through the upper outer periphery of the fixed frame 13 to the left.

  The FPC 102 includes an X motor connector portion 102a, a Y motor connector portion 102b, PI connector portions 102c and 102d, a lateral extension portion 102e, a downward extension portion 102f, and a camera electrical control connector portion 102g. (Fig. 2).

  In the FPC 102, the Y motor connector portion 102 b is connected to the Y drive motor 81, the PI connector portion 102 d is connected to PI 86, and the PI connector portion 102 c is connected to PI 76, and then the lateral extension portion 102 e is connected to the right side surface of the fixed frame 13. After the X motor connector portion 102a is connected to the X drive motor 71, the downward extending portion 102f is inserted along the outer periphery of the lower portion of the fixed frame. And the camera electrical control connector part 102g extended in the left direction is connected to a camera electrical control part (not shown).

  The FPC 103 includes an image sensor mounting connecting portion 103a, a V-shaped bent portion 103b with a central slit for supporting the image sensor 96 so as to be displaceable on the XY plane, and a camera electrical control connector portion 103c. (FIG. 2).

  In the FPC 103, after the mounting connection portion 103a is connected to the image sensor 96, the back surface portion of the base plate 14 is moved to the left through the V-shaped bent portion 103b stored in the FPC bent portion storing recess 14f (FIG. 8) of the base plate 14. The camera electrical control connector portion 103c that is inserted through and extends in the left direction is connected to a camera electrical control portion (not shown).

  A retracting operation, a feeding operation, a blur correction operation, and the like in the lens barrel 1 of the present embodiment having the above-described configuration will be described.

  The lens barrel 1 is set in the wide-angle or tele-photographable state shown in FIGS. 9 and 10 by the extension operation from the retracted state shown in FIG. Specifically, the zoom motor 51 is driven under the control of the camera-side control unit, and the rotary frame 11 is rotated and driven out. As the rotary frame 11 is rotated and extended, first, the barrier unit 3 is opened, and the first group frame 4, the second group frame 6, the third group frame 7, and the shutter / aperture unit 8 are each based on distance measurement signals. Move to the zoom position. Further, the focus motor 61 is driven based on the distance measurement signal, the fourth group frame 12 is extended to the focus position, and the lens barrel 1 is ready for photographing.

  Further, at the time of blur correction shooting, when the image sensor 96 is exposed, an X drive motor is controlled under the control of the control unit of the digital camera based on the camera shake signal detected by the camera shake detection sensor on the digital camera side. 71 and the Y drive motor 81 are driven, the Y frame 15 and the X frame 16 are displaced accordingly, and the image sensor 96 is driven in a direction to correct camera shake. An imaging signal without camera shake is output from the imaging device 96 arranged on the X frame 16 driven in the camera shake correction direction.

  When the lens barrel 1 is retracted from the shootable state to the retracted state, each movable frame member is retracted to the fixed frame 13 side by driving the zoom motor 51 and the focus motor 61 to be in the retracted state. In the retracted state, the movable frame members are in close contact with each other or in a state very close to close contact, and the first group lens 22 to the fourth group lens 23 are also in close contact with each other. Therefore, shortening of the total length in the optical axis O direction in the retracted state can be realized.

  Further, as described above, the zoom drive unit 50 for driving the lens barrel forward and backward is disposed on the right side of the outer peripheral portion of the fixed frame 13, and the focus drive unit 60 is disposed on the upper left of the outer peripheral portion of the fixed frame 13. Further, the X drive unit 70 and the Y drive unit for blur correction are located at the right upper and lower corners of the base plate 14 so that there is no dead space above and below the zoom motor 51 on the right side of the outer periphery of the fixed frame 13. Deploy.

  The FPC 101 for connecting the zoom drive unit 50, the focus drive unit 60, the shutter / aperture unit 8 and the camera control unit, and the FPC 102 for connecting the X drive unit 70 and the Y drive unit and the camera control unit are fixed. It is arranged to extend toward the camera control unit side along the top and bottom of the outer periphery of the frame 13. With these arrangement structures, the projection area in the optical axis O direction occupied by the lens barrel 1 including the blur correction imaging unit 90 can be reduced, and downsizing of the lens barrel 1 as an imaging device can be realized.

  Further, in the rotation transmission mechanism 59 of the focus drive unit 60, a pair of nuts 64A and 64B are applied as nuts to be screwed to the lead screw 66, and a torsion spring 69 that urges the nut to rotate between the nuts 64A and 64B. The rotation restricting protrusion 64b of each of the nuts 64A and 64B is inserted into the guide groove 13e of the fixed frame 13. Accordingly, the nuts 64A and 64B can be driven to move back and forth in the direction of the optical axis O in a state where there is no backlash between the rotation restricting protrusion 64b and the guide groove 13e, and noise is generated at the fitting portion between the rotation restricting protrusion 64b and the guide groove 13e. Is reduced. As the pair of nuts 64A and 64B uses the same shape member as described above, there is no increase in the types of parts compared to the case of using a conventional single nut.

  As shown in FIG. 14, in addition to the guide groove 13e as a guide groove of the fixed frame 13 into which the rotation restricting protrusions 64b of the pair of nuts 64A and 64B in the rotation transmission mechanism 59 of the focus drive unit 60 are inserted. The guide grooves 13f are provided, and the guide grooves into which the respective rotation restricting projections 64b are fitted can be selected, thereby enabling adjustment of the rotational biasing force of the torsion spring 69 or fine adjustment of the advance / retreat position of the fourth group frame 12. Become.

  The torsion spring 69 applied to the rotation transmission mechanism 59 has a coil spring shape. However, instead of this, for example, a U-shaped leaf spring can be applied, and in this case, the assemblability is improved.

  Moreover, it is also possible to propose the 1st rotation transmission mechanism 77A which has the structure shown in FIG. 20 as a modification with respect to the 1st rotation transmission mechanism 77 of the X drive unit 70 which is a 1st drive part mentioned above. The first rotation transmission mechanism 77A of this modification is a mechanism having a configuration similar to the rotation transmission mechanism 59 of the focus drive unit 60 described above, and as a nut screwed to the lead screw 74 in addition to the lead screw 74. A pair of nuts 78A and 78B and a torsion spring 79 are provided.

  The pair of nuts 78A and 78B have the same shape, and can slide in the female screw portion 78a screwed into the lead screw 74 and the guide groove 14h (FIG. 2) along the X direction of the base plate 14. And a protrusion 78c, 78d provided on both end surfaces in the X direction of the rotation restricting protrusion 78b.

  The torsion spring 79 is interposed between the nut 78A and the nut 78B, and is inserted into the lead screw 74 while being compressed in the X direction. Further, the spring hook portions 79a and 79b are respectively connected to the convex portion 78d of the nut 78A and the convex portion of the nut 78B. It is assembled in a state where it is suspended on the part 78c and separated from each other.

  The nut 78A and the nut 78B are rotated and biased by the torsion spring 79 in opposite directions of rotation, and are biased and held in directions away from each other in the X direction. Therefore, when the lead screw 74 is stopped and rotated, the nut 78A and the nut 78B are moved in the X direction with the respective rotation restricting projections 78b being free from the rotation of the guide groove 14h of the base plate 14. Support as possible.

  In the rotation transmission mechanism 77A of this modified example, the lead screw 74 is rotationally driven as the X drive motor 71 rotates, and the pair of nuts 78A and 78B both move forward and backward. The X frame 16 is displaced in the X direction according to the movement. At that time, the rotation restricting protrusions 78b of the nuts 78A and 78B as a pair are slidably fitted in the guide groove 14h of the base plate 14 without any play, and noise due to play in the guide groove is generated. Is prevented.

  Similarly, a second rotation transmission mechanism 87A can be proposed as a modified example of the second rotation transmission mechanism 87 of the Y drive unit 80 that is the second drive unit described above. As shown in FIG. 20, the second rotation transmission mechanism 87 A has the same configuration as the first rotation transmission mechanism 77 A of the modified example described above. In addition to the lead screw 84, the second rotation transmission mechanism 87 A is screwed onto the lead screw 84. A pair of nuts 85 </ b> A and 85 </ b> B and a torsion spring 89 are provided as mating nuts. The second rotation transmission mechanism 87A operates in the same manner as the first rotation transmission mechanism 77A, and the Y frame 15 is displaced in the Y direction by moving the pair of nuts 85A and 85B together, and the same effect is obtained. Play.

  Further, a configuration similar to the rotation transmission mechanism 59 applied to the focus drive unit 60 employs a folding imaging optical system in which the imaging lens optical axis is bent in an imaging device such as a digital camera, and uses a lead screw. The present invention can also be applied to the rotation transmission mechanism of the focus drive unit.

  The present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the invention at the stage of implementation. Further, the above embodiments include inventions at various stages, and various inventions can be extracted by appropriately combining a plurality of disclosed constituent elements.

  As described above, the lens barrel and the image pickup apparatus of the present invention can be used as a lens barrel and an image pickup apparatus provided with a drive mechanism that applies a lead screw with low noise during driving operation.

12 ... Four-group frame (focus lens holding frame)
13 ... fixed frame 13e ... guide groove (guide groove, rotation transmission mechanism)
14 ... Base plate (base member)
14h ... guide groove (guide groove, first rotation transmission mechanism)
24. Four-group lens (imaging optical system, focus lens group)
59 ... Rotation transmission mechanism 60 ... Focus drive unit 61 ... Focus motor 64A, 64B ... A pair of nuts (rotation transmission mechanism)
64b ... Rotation restricting projection (projection, rotation transmission mechanism)
66 ... Lead screw (rotation transmission mechanism)
69 ... Torsion spring (biasing member, rotation transmission mechanism)
70 ... X drive unit (first drive unit)
71 ... X drive motor (first motor)
74 ... Lead screw (first rotation transmission mechanism)
77A ... first rotation transmission mechanism 78A, 78B ... a pair of nuts (first rotation transmission mechanism)
78b ... Rotation restricting protrusion (protrusion, first and second rotation transmission mechanism)
79 ... Torsion spring (biasing member, first rotation transmission mechanism)
80 ... Y drive unit (second drive unit)
81 ... Y drive motor (second motor)
84 ... Lead screw (second rotation transmission mechanism)
87A ... second rotation transmission mechanism 85A, 85B ... a pair of nuts (second rotation transmission mechanism)
89 ... Torsion spring (biasing member, second rotation transmission mechanism)
O ... Optical axis (optical axis of the photographic optical system)
X ... first direction Y ... second direction

Claims (2)

A fixed frame,
An imaging optical system having a focus lens group having an imaging lens optical axis;
A focus lens holding frame for holding the focus lens group;
A focus drive unit that is disposed on an outer peripheral portion of the fixed frame and includes a focus motor and a rotation transmission mechanism for performing focus drive of the focus lens group;
The rotation transmission mechanism has an axis along the optical axis direction of the imaging lens, is driven to rotate by the focus motor, and advances and retracts the focus lens holding frame; A pair of nuts that are screwed into the lead screw and arranged opposite to each other and provided with projections, and the projections are provided on the fixed frame, and the projections are used to regulate the rotation of the pair of nuts. A guide groove portion that is slidably fitted in the lens optical axis direction and the pair of nuts, urges the pair of nuts away from each other, and the pair of nuts mutually A lens barrel comprising a biasing member that biases in opposite directions of rotation. A fixed frame,
An imaging optical system having a focus lens group having an imaging lens optical axis;
An image sensor that receives an optical image formed through the photographing optical system and generates image data;
A base member coupled to the fixed frame and supporting the image sensor so as to be displaceable in a first direction and a second direction orthogonal to the first direction within a plane parallel to the light receiving surface of the image sensor;
A first motor that is disposed on the base member and that drives the imaging device in the first direction and includes a first rotation transmission mechanism, and a second motor that drives in the second direction And a second drive unit including a second rotation transmission mechanism;
The first rotation transmission mechanism and the second rotation transmission mechanism are rotationally driven by the first motor or the second motor, and the image sensor is moved in the first direction or the second direction. A lead screw that is displaced in two directions, a pair of nuts that are screwed into the lead screw and provided with projections, and the projections are slidably fitted to restrict rotation of the pair of nuts. The guide groove provided in the base member and the pair of nuts are arranged to urge the nuts in a direction away from each other, and the pair of nuts in a rotational direction opposite to each other. An image pickup apparatus comprising an urging member for urging.

Images