JP2006317809A - Lens barrel and imaging apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lens barrel capable of restraining the variation of aberration on image formation when performing focusing operation. <P>SOLUTION: A shutter device 21 is moved between a position set when an image is picked up and a position set when an image is not picked up interlocked with the movement of a zoom optical system 27 between the position set when the image is picked up and the position set when the image is not picked up by a zoom optical system moving means 29 moving the zoom optical system 27 in an optical axis direction. A focus lens L4 can be disposed at a position comparatively separate from the shutter device 21, and the variation of aberration on the image formation when performing focusing operation is restrained while restraining the upsizing of the lens barrel 3. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a lens barrel that is extended from the casing when in use and is moved toward the casing when not in use, and an imaging apparatus including the lens barrel.

  2. Description of the Related Art Conventionally, a camera as an imaging apparatus includes a camera body as a housing and a lens barrel provided on the camera body.

  The lens barrel is extended from the camera body side to the subject side during shooting, and is retracted into the camera body while shortening the overall length when not shooting, and the amount that protrudes from the camera body when not shooting There is a so-called collapsible type that makes the minimum possible.

  In such a retractable lens barrel, the distance between the lens arranged in the optical axis direction and the shutter unit as the light shielding means is made as narrow as possible when not photographing and is transferred into the camera body. By configuring so that the amount of protrusion can be reduced, the amount of protrusion from the camera body can be further reduced.

  Therefore, the collapsible that shortens the overall length is configured such that the distance between the shutter unit adjacent to the rear side of the shutter unit in the optical axis direction and movable back and forth along the optical axis direction is narrowed during non-imaging. A zoom lens barrel of a type is known (for example, see Patent Document 1).

  The lens barrel described in FIGS. 1 to 3 of Patent Document 1 includes a second lens group for zooming and a shutter unit from the front side in the optical axis direction on a moving frame that can move back and forth along the optical axis direction. Are sequentially supported, and the focus unit is supported on the moving frame, and the focusing unit is moved back and forth along the optical axis direction by the focus unit separately from the moving frame on the rear side in the optical axis direction of the moving frame. The third lens group is disposed, and when the lens barrel is retracted, the front portion of the third lens group in the optical axis direction is inserted into the shutter unit, thereby reducing the distance between the third lens group and the shutter unit. Is.

Further, in the lens barrel described in FIGS. 6 to 8 of Patent Document 1, two shutter groups are fixed to a moving frame that can move back and forth along the optical axis direction, and the second lens group is held. The lens frame is supported by the moving frame so as to be movable back and forth along the optical axis direction with respect to the shutter unit, and the optical characteristics are prioritized for the intervals between the second lens group and the third lens group and the shutter unit. On the other hand, it is possible to reduce the total length of the lens barrel by narrowing this interval during non-imaging, while the interval can be reduced.
Japanese Patent No. 3496667 (page 3-5, FIGS. 1-3 and 6-8)

  As described above, in the lens barrel described in Patent Document 1, the third lens group, or the second lens group and the third lens group positioned on the rear side in the optical axis direction of the shutter unit are relatively moved when retracted. By moving the shutter unit toward the shutter unit side, the displacement amount of the shutter unit and the first to third lens groups in the rear direction in the optical axis direction can be increased, and the overall length of the lens barrel can be shortened as much as possible. Since the focus unit for moving the third lens group or the second lens group and the third lens group is provided in the moving frame to which the shutter unit is fixed, the third lens group for focus is the shutter unit. Are disposed relatively close to each other.

  However, when the shutter unit and the third lens group for focusing are relatively close to each other as described above, the third lens group or the second lens group and the third lens group are moved to perform focusing operation, that is, focusing. However, there is a problem that the influence of aberration fluctuations is likely to appear in image formation.

  SUMMARY An advantage of some aspects of the invention is that it provides a lens barrel that suppresses variation in aberrations in image formation during a focusing operation, and an imaging apparatus including the lens barrel.

  The lens barrel according to claim 1 is a lens barrel that is provided in a casing and is extended from the casing when in use and retracted toward the casing when not in use. The zoom optical system and the zoom optical system Zoom optical system moving means for performing a zoom operation by moving the lens along the optical axis direction, a focus optical system that forms an image of subject light on the imaging surface, and moving the focus optical system along the optical axis direction Focusing optical system moving means for performing a focusing operation and a light shielding means for restricting the amount of light passing therethrough, and the zoom optical system moving means is located at a position corresponding to each of when in use and when not in use. In addition to moving the zoom optical system, the light shielding means is moved to the use position and the non-use position in conjunction with the movement of the zoom optical system.

  Then, the zoom optical system moving means for moving the zoom optical system moves the light shielding means between the use position and the non-use position in conjunction with the movement between the use position and the non-use position of the zoom optical system. As a result, the focus optical system can be disposed at a position relatively distant from the light shielding means, and fluctuations in aberrations to image formation during the focus operation are suppressed.

  According to a second aspect of the present invention, in the lens barrel according to the first aspect, the zoom optical system includes one and the other different lens optical systems disposed back and forth in the optical axis direction, and these lens optics. One and the other lens holding frame for holding the system respectively, and the zoom optical system moving means is a distance between the use area where the zoom optical system is zoomed and the one and other lens optical systems of the zoom optical system And a light shielding means disposed between the lens optical systems, and a position in use and a position in non-use with respect to the one lens holding frame. An urging means provided between the light shielding means and the one lens holding frame, for urging the light shielding means from a non-use position to a use position, and the other lens. Holding frame and Respectively provided on the serial light-shielding means is obtained by including a contact portion abutting each other in the optical axis direction by the non-use area.

  Then, the urging means provided between the one lens holding frame that holds one lens optical system and the light shielding means enables the light shielding means to be moved from the non-use position to the use position. At the same time, the other lens holding frame that holds the other lens optical system and the light shielding means are brought into contact with each other in the non-use region of the cam portion so that the light shielding means can be moved to the non-use position. Thus, it is possible to move the light shielding means while suppressing an increase in size and an increase in the number of parts.

  The lens barrel according to claim 3 is the lens barrel according to claim 2, wherein the light shielding means includes a light shielding plate, and the abutting portion on the light shielding means side holds the other lens with respect to the light shielding plate. It is provided at a position that does not overlap in the direction of contact with the contact portion on the frame side.

  By providing the abutting portion on the light shielding means side at a position that does not overlap the abutting direction with respect to the abutting portion on the other lens holding frame side with respect to the light shielding plate, Deformation of the light shielding plate is reliably prevented.

  According to a fourth aspect of the present invention, there is provided an imaging apparatus comprising a casing and the lens barrel according to any one of the first to third aspects provided in the casing.

  By providing the lens barrel according to any one of claims 1 to 3, fluctuations in aberrations to image formation during the focusing operation are suppressed, and stable imaging is possible.

  According to the present invention, it is possible to dispose the focus optical system at a position relatively away from the light shielding means, and it is possible to suppress fluctuations in aberrations to image formation during the focus operation.

  Hereinafter, the configuration of an imaging apparatus according to an embodiment of the present invention will be described with reference to the drawings.

  1 to 3, reference numeral 1 denotes a digital camera as an imaging device. The digital camera 1 includes a camera body 2 as a housing, and a substantially cylindrical lens barrel 3 provided in the camera body 2. It has.

  Hereinafter, for convenience, along the optical axis from the subject to the imaging plane, the left side shown in FIGS. 1 to 3 which is the subject side is the front side, and the right side shown in FIGS. 1 to 3 is the imaging plane side. 3 is assumed to be the rear side, and the vertical direction shown in FIGS. 1 to 3 orthogonal to the optical axis is assumed to be the vertical direction. FIGS. 1 to 3 are longitudinal sectional views of the imaging apparatus 1. However, since the internal structure cannot be appropriately described when represented as a longitudinal sectional view on a single plane passing through the optical axis, It is a longitudinal sectional view showing the position of the cross section appropriately changed so that the internal structure can be easily understood.

  The camera body 2 is formed in, for example, a hollow rectangular parallelepiped shape, and an opening (not shown) to which the lens barrel 3 is attached corresponding to the shape of the lens barrel 3 is formed on the front side.

  The lens barrel 3 is a so-called collapsible zoom lens barrel, and the camera from the wide-angle state (wide state) shown in FIG. 1 to the telephoto state (tele state) shown in FIG. 3 is retracted toward the subject side with respect to the main body 2 and is retracted into the camera main body 2 when the digital camera 1 is not used, that is, not imaged, as shown in FIG.

  This lens barrel 3 moves from the outer peripheral side to the inner peripheral side, a fixed cam barrel 11, a retractable barrel 12, a first rectilinear barrel 13, a second rectilinear barrel 14, a first group lens holding frame 15 holding a lens L1, and movement The cam barrel 16, the third rectilinear barrel 17, the second group lens holding frame 18 as a lens holding frame as one lens holding frame holding the lens group L2 as one lens optical system, and the other lens optical system A third lens group holding frame 19 is sequentially provided as the other lens holding frame that holds the second lens group L3.

  Further, the lens barrel 3 is disposed on the front side of the third group lens holding frame 19, that is, between the second group lens holding frame 18 and the third group lens holding frame 19 at a position where the principal ray of the subject light intersects the optical axis. A shutter device 21 as a light shielding means is attached in the vicinity, and a rear end portion of the fixed cam cylinder 11 is attached to a substrate portion 22 fixed to the camera body 2. As a focusing optical system moving means that holds a focusing lens holding frame 23 as a focusing lens holding frame holding a focusing lens as a system, that is, a focusing lens holding frame L4, in a worm gear-like lead portion 24a so as to be movable along the optical axis direction An autofocus motor 24 (hereinafter abbreviated as AF motor 24) and an image sensor 25 are respectively attached.

  In the lens barrel 3, a zoom optical system 27 is configured by a lens L1, a lens group L2, and a lens group L3 that are sequentially arranged from the front side to the rear side in the optical axis direction and the diameters are gradually reduced. The zoom optical system is driven by a drive motor (not shown) as a moving means for applying a rotational force for rotating the cylinders 11 to 14, 16, 17, the holding frames 15, 18, 19, and the retractable cylinder 12 around the optical axis. A zoom optical system moving means 29 is configured to perform a zoom operation by moving 27 along the optical axis direction.

  The fixed cam cylinder 11 is formed in a substantially cylindrical shape, constitutes the outer periphery of the lens barrel 3, and sets the entire length of the lens barrel 3 in the retracted state shown in FIG. Regardless of time, almost the entire camera body 2 is accommodated. A plurality, for example, three fixed cam grooves 31 and a plurality, for example, three fixed rectilinear grooves 32 extending in parallel with the optical axis are formed on the inner peripheral surface of the fixed cam cylinder 11.

  The fixed cam groove 31 forms part of the cam portion 28, and moves the retractable cylinder 12 along the optical axis direction with respect to the fixed cam cylinder 11, and is spaced 120 ° in the circumferential direction around the optical axis. Are formed in a substantially rotationally symmetrical manner around the optical axis. Further, as shown in FIG. 4, the fixed cam grooves 31 are provided as an open portion 34 that is continuously opened to the outside at the rear end portion of the fixed cam cylinder 11, and a non-use area that is continuous to the open portion 34. A non-imaging area 35 and an imaging area 36 as a use area continuous to the non-imaging area 35 are provided.

  The opening 34 is formed in a straight line parallel to the optical axis.

  In the non-imaging area 35, a continuous part with the open part 34 is formed linearly along the circumferential direction of the fixed cam cylinder 11, and forwards along the circumferential direction of the fixed cam cylinder 11 toward the imaging area 36 side. It is slightly inclined to form a straight line.

  The imaging area 36 is curved and formed in a substantially arc shape that protrudes rearward along the circumferential direction of the fixed cam cylinder 11, and the end opposite to the non-imaging area 35 is more than the end on the non-imaging area 35 side. Is also formed on the front side and linearly along the circumferential direction of the fixed cam cylinder 11.

  The non-imaging area 35 and the imaging area 36 set the amount of movement of the retractable cylinder 12 shown in FIGS. 1 to 3 in the optical axis direction.

  The fixed rectilinear groove 32 guides the first rectilinear cylinder 13 back and forth along the optical axis direction and restricts the rotation of the first rectilinear cylinder 13 in the circumferential direction. Near the non-imaging area 35 side of the imaging area 36 and the front end of the imaging area 36 opposite to the non-imaging area 35 side. Located behind the end.

  As shown in FIGS. 1 to 3, the retractable cylinder 12 is formed in a substantially cylindrical shape, and a gear portion 38 that meshes with the output portion of the drive motor is provided in a belt shape along the circumferential direction at the outer peripheral portion of the rear end portion. It has been. Further, a plurality of, for example, three cam followers 39 corresponding to the fixed cam grooves 31 are provided in front of the gear portion 38 at the rear of the retractable cylinder 12 so as to engage with the fixed cam grooves 31. Further, a groove 41 that engages with the first rectilinear cylinder 13 is formed in the inner peripheral portion of the front portion of the retractable cylinder 12 along the circumferential direction. A plurality of, for example, three cam grooves 45 are formed in the inner peripheral portion of the retractable cylinder 12.

  The cam followers 39 are provided substantially rotationally symmetrically around the optical axis at intervals of 120 ° in the circumferential direction around the optical axis. These cam followers 39 are inserted from the opening 34 of the fixed cam groove 31 when the lens barrel 3 is assembled.

  Further, the groove portion 41 makes the first rectilinear cylinder 13 rotatable in the circumferential direction with respect to the retractable cylinder 12 and restricts the movement of the first rectilinear cylinder 13 in the front-rear direction with respect to the retractable cylinder 12. .

  Further, the cam groove 45 forms a part of the cam portion 28, and moves the movable cam cylinder 16 along the optical axis direction with respect to the retractable cylinder. The cam groove 45 is spaced by 120 ° in the circumferential direction around the optical axis. Are formed in a substantially rotationally symmetrical manner around the optical axis.

  Further, the cam grooves 45 are formed in a substantially rotational symmetry around the optical axis at intervals of 120 ° in the circumferential direction around the optical axis. Further, as shown in FIG. 5, the cam grooves 45 are a non-imaging area 48 as a non-use area formed at a position behind the retractable cylinder 12 and a use area continuous to the non-image area 48. The imaging area 49 is provided.

  The non-imaging area 48 has an end opposite to the imaging area 49 formed in a straight line along the circumferential direction of the retractable cylinder 12, and inclines forward toward the imaging area 49 along the circumferential direction of the retractable cylinder 12. It is formed in a straight line.

  Further, the imaging region 49 is formed in a straight line along the circumferential direction from a continuous portion with the non-imaging region 48.

  The non-imaging area 48 and the imaging area 49 set the amount of movement of the movable cam cylinder 16 shown in FIGS. 1 to 3 in the optical axis direction.

  The first rectilinear cylinder 13 is formed in a substantially cylindrical shape, and a first protrusion 43 that protrudes in the radial direction and engages with each of the fixed rectilinear grooves 32 of the fixed cam cylinder 11 is fixed to the outer peripheral portion of the rear end portion. A plurality of, for example, three protrusions corresponding to the rectilinear grooves 32 are provided. Further, a first engaging portion 44 that engages with the groove portion 41 of the retractable cylinder 12 projects in the radial direction on the outer peripheral portion of the front end portion of the first rectilinear cylinder 13. In the inner peripheral portion of the first rectilinear cylinder 13, a plurality of, for example, three first rectilinear grooves 46 parallel to the optical axis are located slightly forward from the rear end portion of the center portion in the front-rear direction. Each is formed.

  The first protrusions 43 are provided at intervals of 120 ° in the circumferential direction around the optical axis, that is, substantially rotationally symmetrical around the optical axis, and are located on the rear side of the rear end portion of the retractable cylinder 12. Is engaged with the fixed rectilinear groove 32. The first protrusions 43 are inserted into the fixed rectilinear grooves 32 from the rear end portions of the fixed rectilinear grooves 32 when the lens barrel 3 is assembled.

  The first rectilinear groove 46 guides the second rectilinear cylinder 14 and the third rectilinear cylinder 17 shown in FIGS. 1 to 3 back and forth along the optical axis direction, and the second rectilinear cylinder 14 and the third rectilinear cylinder 17. And is formed in a substantially rotationally symmetrical manner around the optical axis at intervals of 120 ° in the circumferential direction.

  As shown in FIGS. 1 to 3, the second rectilinear cylinder 14 is formed in a substantially cylindrical shape, and protrudes radially in the outer peripheral portion of the rear end portion to each of the first rectilinear grooves 46 of the first rectilinear cylinder 13. A plurality of, for example, three projecting portions 51 corresponding to the first rectilinear grooves 46 are provided. Further, a second engagement portion 52 that engages with the outer peripheral portion of the movable cam cylinder 16 is projected from the inner peripheral portion of the rear end portion of the second rectilinear cylinder 14. Further, a plurality of, for example, three second rectilinear grooves 53 are formed on the inner peripheral portion of the second rectilinear cylinder 14 in a straight line parallel to the optical axis from the rear end portion to the vicinity of the front end portion.

  The second projecting portion 51 and the second rectilinear groove 53 are provided substantially at rotational symmetry about the optical axis at intervals of 120 ° in the circumferential direction with the optical axis as the center. The second rectilinear groove 53 guides the first group lens holding frame 15 back and forth along the optical axis direction and restricts the rotation of the first group lens holding frame 15 in the circumferential direction.

  The first group lens holding frame 15 is formed in a substantially cylindrical shape, and a plurality of, for example, three pins 56 that engage with each of the second rectilinear grooves 53 of the second rectilinear cylinder 14 correspond to the second rectilinear grooves 53. It is arranged penetrating in the radial direction. Further, cam followers 57 are provided on the respective pins 56 on the inner peripheral side of the first group lens holding frame 15, and these cam followers 57 are respectively engaged with the outer peripheral portion of the movable cam cylinder 16. Further, a front end portion of the first group lens holding frame 15 is provided with a first group flange portion 58 that holds the lens L1 projecting from the inner peripheral portion toward the central axis.

  The pins 56 and the cam followers 57 are provided in a substantially rotational symmetry around the optical axis at intervals of 120 ° in the circumferential direction around the optical axis. Further, the pin 56 is inserted into the second rectilinear groove 53 from the rear end portion of the second rectilinear groove 53 when the lens barrel 3 is assembled.

  The movable cam cylinder 16 is formed in a substantially cylindrical shape, and is inserted into the first rectilinear groove 46 of the first rectilinear cylinder 13 behind the second rectilinear cylinder 14 and the first group lens holding frame 15 in the outer peripheral portion of the rear end. A plurality of, for example, three cam followers 61 corresponding to the cam grooves 45 are provided so as to engage with the cam grooves 45 of the retractable cylinder 12. In addition, an outer peripheral groove 62 that engages with the second engaging portion 52 of the second rectilinear cylinder 14 is formed in the outer peripheral portion of the movable cam cylinder 16 on the front side of the cam follower 61 along the circumferential direction. Further, a plurality of, for example, three outer peripheral cam grooves 63 corresponding to the cam followers 57 are formed on the outer peripheral portion of the movable cam cylinder 16 to be engaged with the cam followers 57 of the first group lens holding frame 15. The inner peripheral portion of the movable cam cylinder 16 is formed with an inner peripheral groove portion 64 that is engaged with the outer peripheral portion of the third rectilinear cylinder 17 along the circumferential direction at the rear end portion. Three first inner circumferential cam grooves 65 and second inner circumferential cam grooves 66 are formed.

  The cam followers 61 are respectively provided substantially rotationally symmetrically around the optical axis at intervals of 120 ° in the circumferential direction around the optical axis.

  The outer circumferential groove 62 makes the movable cam cylinder 16 and the second rectilinear cylinder 14 relatively rotatable in the circumferential direction, and relatively moves the movable cam cylinder 16 and the second rectilinear cylinder 14 in the front-rear direction. Is to regulate.

  The outer peripheral cam groove 63 forms a part of the cam portion 28, and moves the first group lens holding frame 15 along the optical axis direction with respect to the movable cam cylinder 16, and 120 in the circumferential direction about the optical axis. They are formed approximately at rotational intervals, ie, around the optical axis. Further, as shown in FIG. 6, these outer peripheral cam grooves 63 are provided as an open portion 71 that is continuously open to the outside continuously from the rear end portion of the movable cam cylinder 16, and a non-use area that is continuous to these open portions 71. A non-imaging area 72 and an imaging area 73 as a use area continuous with the non-imaging area 72 are provided.

  The opening portions 71 are linearly formed parallel to the optical axis, and the cam followers 57 of the movable cam barrel 16 are inserted into the opening portions 71 when the lens barrel 3 is assembled.

  In the non-imaging region 72, a continuous portion with the open portion 71 is formed linearly along the circumferential direction of the movable cam cylinder 16, and along the circumferential direction of the movable cam cylinder 16 toward the non-imaging region 72 side. It is formed to incline forward and extends to the vicinity of the front end portion of the movable cam cylinder 16.

  The imaging region 73 is formed in a linear shape that is slightly inclined forward from a continuous portion with the non-imaging region 72.

  The non-imaging area 72 and the imaging area 73 set the amount of movement of the first group lens holding frame 15 shown in FIGS. 1 to 3 in the optical axis direction.

  The inner circumferential groove 64 makes the movable cam cylinder 16 and the third rectilinear cylinder 17 shown in FIGS. 1 to 3 relatively rotatable in the circumferential direction, and also shows the movable cam cylinder 16 and FIGS. 1 to 3. The relative movement in the front-rear direction with respect to the third rectilinear cylinder 17 is restricted.

  The first inner peripheral cam groove 65 forms a part of the cam portion 28 and moves the second group lens holding frame 18 shown in FIGS. 1 to 3 along the optical axis direction with respect to the movable cam cylinder 16. The optical axis is formed at an interval of 120 ° in the circumferential direction around the optical axis, that is, substantially rotationally symmetrical around the optical axis. Further, as shown in FIG. 7, the first inner peripheral cam groove 65 includes a non-imaging area 75 as a non-use area formed from a central area in the front-rear direction of the movable cam cylinder 16, and the non-imaging area 75. And an imaging region 76 as a continuous use region.

  The non-imaging area 75 has an end opposite to the imaging area 76 formed in a straight line along the circumferential direction of the movable cam cylinder 16 and extends along the circumferential direction of the movable cam cylinder 16 toward the imaging area 76 side. And a continuous portion with the imaging region 76 is formed linearly along the circumferential direction of the movable cam cylinder 16.

  The imaging area 76 has a continuous portion with the non-imaging area 75 formed in a straight line along the circumferential direction of the movable cam cylinder 16, and the movable cam cylinder 16 extends toward the end opposite to the non-imaging area 75. It is formed to be inclined rearward along the circumferential direction.

  The non-imaging area 75 and the imaging area 76 form a first inner cam groove 65 in a square shape in plan view, and the second group lens holding frame 18 shown in FIGS. 1 to 3 moves in the optical axis direction. The amount is set.

  On the other hand, the second inner peripheral cam groove 66 forms a part of the cam portion 28 and moves the third group lens holding frame 19 shown in FIGS. 1 to 3 along the optical axis direction with respect to the movable cam cylinder 16. They are formed in a substantially rotationally symmetrical manner around the optical axis at intervals of 120 ° in the circumferential direction around the optical axis. The second inner peripheral cam groove 66 includes an open part 81 that is continuously open to the rear end of the movable cam cylinder 16 and a non-imaging area 82 that is a non-use area that is continuous to the open part 81. An imaging region 83 as a use region continuous with the non-imaging region 82 and a continuous portion 84 continuous between the imaging region 83 and the imaging region 76 of the first inner peripheral cam groove 65 are provided.

  The open part 81 is formed in a straight line parallel to the optical axis.

  In the non-imaging region 82, a continuous portion with the open portion 81 is formed linearly along the circumferential direction of the movable cam cylinder 16, and along the circumferential direction of the movable cam cylinder 16 toward the non-imaging region 82 side. Inclined rearward and linearly formed, and a continuous portion with the imaging region 83 is formed linearly along the circumferential direction of the movable cam cylinder 16.

  The imaging area 83 has a continuous portion with the non-imaging area 82 formed in a straight line along the circumferential direction of the movable cam cylinder 16, and the movable cam cylinder 16 extends toward the end opposite to the non-imaging area 82. The first inner circumferential cam groove 65 is formed behind the non-imaging region 75 of the first inner circumferential cam groove 65 so as to be inclined forward along the circumferential direction.

  The non-imaging area 82 and the imaging area 83 set the amount of movement of the third rectilinear cylinder 17 shown in FIGS. 1 to 3 in the optical axis direction.

  The continuous portion 84 extends from the imaging region 83 along the circumferential direction of the movable cam cylinder 16, and is folded back in the circumferential direction so as to continue to the imaging region 76 of the first inner circumferential cam groove 65. Yes.

  As shown in FIGS. 1 to 3, the third rectilinear cylinder 17 is formed in a substantially cylindrical shape, and the first rectilinear groove of the first rectilinear cylinder 13 on the outer periphery of the rear end portion behind the movable cam cylinder 16. A plurality of, for example, three projecting portions 86 corresponding to the first rectilinear grooves 46 are provided to be engaged with the respective 46. Further, a third engaging portion 87 is provided on the outer peripheral portion of the third rectilinear cylinder 17 so as to engage with the inner peripheral groove portion 64 of the movable cam cylinder 16 on the front side of the third projecting portion 86. . Further, the third rectilinear cylinder 17 is formed with a plurality of, for example, three first rectilinear holes 88 penetrating radially from the inner peripheral side to the outer peripheral side at a position closer to the front side in the front-rear direction. In addition, a plurality of, for example, three second rectilinear holes 89 penetrating in the radial direction from the inner peripheral side to the outer peripheral side are formed at positions closer to the rear side in the front-rear direction.

  The third projecting portion 86, the first rectilinear hole 88, and the second rectilinear hole 89 are provided in a substantially rotationally symmetrical manner around the optical axis at intervals of 120 ° in the circumferential direction. . The third protrusion 86 is inserted into the first rectilinear groove 46 from the rear end of the first rectilinear groove 46 when the lens barrel 3 is assembled. Further, each of the rectilinear holes 88 and 89 is formed linearly along the optical axis direction.

  As shown in FIGS. 8 and 10, the second group lens holding frame 18 holds, for example, lenses L5 and L6 constituting the lens group L2 shown in FIGS. The second group flange portion 91 having a flat and substantially cylindrical shape is provided, and a plurality of, for example, three group second convex portions 92 as three contact portions are provided on the rear side of the outer peripheral edge portion of the second group flange portion 91, respectively. And a portion between the second group convex shape portions 92 is a second group concave shape portion 93. A cylindrical second group holding portion 94 that holds the lenses L5 and L6 is formed at the center of the second group flange portion 91.

  The second group convex portions 92 are provided at substantially equal angles in the circumferential direction around the optical axis, that is, substantially rotationally symmetrical around the optical axis. Round holes 95 are formed, and in these round holes 95, cam followers 96 that are inserted into the first rectilinear holes 88 of the third rectilinear cylinder 17 and engage with the first inner peripheral cam grooves 65 of the movable cam cylinder 16 are provided. Each is attached. These cam followers 96 are inserted into the second inner peripheral cam groove 66 from the opening 81 when the lens barrel 3 is assembled, and are further arranged in the first inner peripheral cam groove 65 via the continuous portion 84. Each second group convex portion 92 is a portion that contacts the shutter device 21 in the retracted state shown in FIG. 3 and pushes the shutter device 21 rearward in the optical axis direction.

  In the second group holding portion 94, the lens L5 is held at the front end portion protruding forward from the second group flange portion 91, and the lens L6 is held at the rear end portion protruding rearward from the second group flange portion 91. .

  The third group lens holding frame 19 holds, for example, lenses L8 and L9 constituting the lens group L3 shown in FIGS. 1 to 3, and is a shaft as a lens holding frame main body having a size substantially equal to that of the second group flange portion 91. A three-group flange portion 101 having a substantially cylindrical shape that is flat in the direction is provided, and a plurality of, for example, three three-group convex-shaped portions 102 project forward from the front edge of the outer peripheral edge of the third group flange portion 101, respectively. The third group concave shape portion 103 is formed between the third group convex shape portions 102. A cylindrical third group holding portion 104 that holds the lenses L8 and L9 is formed at the center of the third group flange portion 101. Further, the second group flange portion 91 is provided with a plurality of round hole-shaped guide holes 105 as, for example, three support portions around the third group holding portion 104, respectively. Escape holes 106, 106 are respectively drilled at two places in between, and at one other place between the guide holes 105, 105, an elongated insertion hole 107 is formed in the circumferential direction.

  The third group convex portions 102 are provided at substantially equal angles in the circumferential direction around the optical axis, that is, substantially rotationally symmetric around the optical axis. Round hole portions 111 are formed, and cam followers that are inserted into the second rectilinear holes 89 of the third rectilinear cylinder 17 and engage with the second inner peripheral cam grooves 66 of the movable cam cylinder 16 are formed in the round hole portions 111. 112 are attached to each. These cam followers 112 are inserted into the second inner peripheral cam groove 66 from the opening 81 when the lens barrel 3 shown in FIGS. 1 to 3 is assembled.

  The third group lens holding frame 19 includes the second group concave shape portion 93 of the third group convex shape portion 102 and the second group lens holding frame 18, and the second group of the third group concave shape portion 103 and the second group lens holding frame 18. In the retracted state shown in FIG. 3, the convex portion 92 is assembled alternately at six locations in the circumferential direction as shown in FIGS. 9 and 11.

  As shown in FIGS. 8 and 10, the third group holding portion 104 has a lens L8 held at the front end portion protruding forward from the third group flange portion 101 and is projected rearward from the third group flange portion 101. A lens L9 is held at the end.

  The guide hole 105 guides the shutter device 21 along the optical axis direction, and is provided at an interval of 120 ° in the circumferential direction around the optical axis, that is, substantially rotationally symmetrical around the optical axis, The third group flange portion 101 on the outer peripheral side of the third group holding portion 104, that is, the inner periphery of the outer peripheral edge portion of the third group lens holding frame 19 is located.

  The escape holes 106 avoid interference between the shutter device 21 and the third group flange portion 101, and are respectively formed at positions below the optical axis, and the third group flange portion 101 on the outer peripheral side of the third group holding portion 104. That is, it is located inside the outer peripheral edge of the third group lens holding frame 19.

  Here, as shown in FIGS. 1 to 3, since the lens barrel 3 is configured to have a diameter corresponding to the lens L1 having the maximum diameter, the lens barrel 3 holds the lens group L3 having the minimum diameter. The third group flange portion 101 around the third group holding portion 104 is wider in the optical axis direction than the first group flange portion 58 of the first group lens holding frame 15, and a dead space is formed in this portion. A guide hole 105 and a relief hole 106 are provided in the dead space.

  The insertion hole 107 is for avoiding interference with the lead portion 24a of the AF motor 24, and is provided at a position above the optical axis.

  The shutter device 21 regulates the amount of light passing therethrough. As shown in FIGS. 8 and 10, the shutter device 21 is provided with a flat, substantially cylindrical shutter device body 115 serving as a light shielding unit body, and the shutter device body 115. And a shutter 116 as a light shielding plate facing the opening 115a at the center of the shutter device main body 115. The shutter device 21 is designed to reduce the size of the shutter device 21 and reduce the influence on the aberration when limiting the light flux passing through the shutter device 21. It is preferable to arrange it near the position where it intersects. In addition, the shutter device 21 is operated by the zoom optical system moving unit 29 in accordance with the movement of the zoom optical system 27 by the zoom optical system moving unit 29 shown in FIGS. 1 to 3, respectively. Moved to.

  The shutter device main body 115 is formed in a D shape by a cut portion 117 as a notch portion for avoiding interference with the lead portion 24a of the AF motor 24 shown in FIGS. 1 to 3, and is formed as a guide convex portion on the back surface, that is, the rear surface. A plurality of, for example, three columnar supported pillars 118 serving as supported parts are respectively provided, and drive motors 119 and 119 which are supported parts as driving means for opening and closing the shutter blades of the shutter 116 are provided. It is attached. Further, the shutter device main body 115 has an outer diameter dimension substantially equal to the inner peripheral edge portion of the third group convex portion 102 of the third group lens holding frame 19, and a plurality of, for example, three protrusions 121 abut on the outer peripheral portion. It is installed.

  The guide pillars 118 are provided corresponding to the guide holes 105 at intervals of 120 ° in the circumferential direction around the optical axis, that is, provided approximately rotationally symmetrical around the optical axis, respectively, and are coil springs as biasing means. The screw 124 is inserted into the guide hole 105 of the third group flange portion 101 of the third group lens holding frame 19 and inserted into the guide hole 105 of the third group lens holding frame 19 with a washer-shaped stopper ring 123 interposed therebetween. It is fixed.

  Note that the guide pillar 118 and the guide hole 105 are preferably disposed at positions that are substantially symmetrical with respect to the center of gravity of the shutter device 21, that is, symmetrically.

  The coil spring 122 is held in a state where the shutter device 21 is attached to the third group lens holding frame 19 and is slightly compressed between the shutter device main body 115 and the third group flange portion 101. An urging force is applied between the front surface of the third group lens holding frame 19 and the shutter device 21 and the third group lens holding frame 19 are urged away from each other. In other words, the coil spring 122 corresponds to the image pickup possible state of the lens barrel 3 shown in FIGS. 1 and 2 from the non-image pickup position corresponding to the retracted state of the lens barrel 3 shown in FIG. It is biased to the position at the time of imaging. That is, the shutter device 21 is elastically supported in the optical axis direction with respect to the third group lens holding frame 19.

  The coil springs 122 are compressed and held between the shutter device main body 115 and the third group flange portion 101 in the retracted state shown in FIG.

  The stopper ring 123 is set to have an outer diameter dimension larger than the inner diameter dimension of the guide hole 105, and serves to prevent the shutter device 21 from coming off.

  The drive motor 119 has a substantially cylindrical outer shape and is inserted into the escape hole 106 of the third group flange portion 101. These drive motors 119 are connected to the shutter blades of the shutter 116 by various gears (not shown).

  The contact portion 121 is formed wide in the circumferential direction and protrudes in the radial direction from the shutter device main body 115. The contact portion 121 is spaced apart by 120 ° in the circumferential direction around the optical axis except for the portion corresponding to the cut portion 117. That is, they are provided approximately rotationally symmetrical around the optical axis. The contact portions 121 protrude to the third group flange portion 101 of the third group lens holding frame 19. For this reason, these contact portions 121 are provided at positions that do not overlap with the shutter 116 in the optical axis direction, and the shutter device 21 is attached to the third group lens holding frame 19 and arranged in the lens barrel 3 together with the second group lens holding frame 18. In the state where it is installed, it faces the second group convex portion 92 of the second group lens holding frame 18 in the optical axis direction, and in the retracted state shown in FIG. In the image pickup state shown in FIGS. 1 and 2, the second group convex shape portions 92 are spaced apart from each other in the optical axis direction.

  The shutter 116 is formed by arranging a plurality of shutter blades of the same shape so as to be rotatable in the circumferential direction, and an opening is formed in the opening 115a by the inner peripheral edge of these shutter blades. The shutter blades are varied by being moved by the drive motor 119. The shutter 116 is opened in the retracted state shown in FIG. 3 so as not to interfere with the lens group L3 fitted in the opening 115a.

  As shown in FIGS. 1 to 3, the substrate portion 22 is attached so as to close the rear opening of the fixed cam cylinder 11, and an element fixing hole 125 for holding and fixing the imaging element 25 is formed in a substantially central portion. A motor fixing hole 126 to which the AF motor 24 is attached is formed above the element fixing hole 125.

  The focus lens holding frame 23 is formed in a substantially cylindrical shape. The focus lens holding frame 23 holds the focus lens L4 at the center portion, and a meshing portion 128 that meshes with the lead portion 24a of the AF motor 24 is provided at the top. The focus lens L4 held by the focus lens holding frame 23 forms an image of subject light from the zoom optical system 27 on the imaging surface of the image sensor 25.

  The AF motor 24 is, for example, a stepping motor, and the driving of the AF motor 24 is controlled by a signal from a control unit (not shown), and the lead unit 24a is rotated in accordance with the focused state on the imaging surface of the image sensor 25, that is, the focus state. Thus, the focus lens L4 is moved back and forth along the optical axis via the focus lens holding frame 23, thereby causing the focus lens L4 to perform a focusing operation.

  The lead portion 24a of the AF motor 24 protrudes forward in parallel with the optical axis.

  The image sensor 25 is a CCD or the like that forms an image formation surface on which the light flux that has passed through the zoom optical system 27 and the focus lens L4 forms an image, and this image formation is converted into an image by various circuits (not shown).

  The zoom optical system moving means 29 rotates the retractable cylinder 12 in the circumferential direction by a drive motor so that the lens holding frames 15, 18, 19 are imaged areas 36, 49, 73, 76, 83 of the cam portion 28. In each of the non-imaging regions 35, 48, 72, 75, and 82, the lens holding frames 15, 18, and 19 are biased toward the image sensor 25 in the non-imaging regions 35, and the lens barrel 3 when not imaging is performed. The total length is shortened.

  Next, the operation of the above embodiment will be described.

  First, the extension operation of the lens barrel 3 for making the digital camera 1 in an imageable state will be described.

  When the power of the digital camera 1 is turned on from the retracted state shown in FIG. 3, the drive motor of the zoom optical system moving means 29 is driven, and the retractable cylinder 12 is fixed to the fixed cam by the gear portion 38 meshed with the output shaft of this drive motor. By rotating clockwise with respect to the cylinder 11 in a front view, the cam follower 39 is engaged with the non-imaging area 35 shown in FIG. 4 of the fixed cam groove 31 of the fixed cam cylinder 11, so that the retractable cylinder 12 is According to the shape of the non-imaging area 35, the retractable cylinder 12 moves forward according to the amount of rotation.

  At this time, in the first rectilinear cylinder 13, the first protrusion 43 is engaged with the fixed rectilinear groove 32 of the fixed cam cylinder 11 and the first engaging portion 44 is engaged with the groove 41 of the retractable cylinder 12. As a result, the retractable cylinder 12 does not follow the rotation in the circumferential direction, but only follows the forward movement of the retractable cylinder 12 and moves forward by the same amount of movement as the retractable cylinder 12.

  Further, the movable cam cylinder 16 is configured such that the cam follower 61 is engaged with the non-imaging region 48 shown in FIG. 5 of the cam groove 45 of the retractable cylinder 12 through the first rectilinear groove 46 of the first rectilinear cylinder 13. In accordance with the shape of the non-imaging region 48 of the cam groove 45, the lens barrel 12 moves forward in accordance with the amount of rotation of the collapsible cylinder 12 while rotating in the circumferential direction following the rotation in the circumferential direction. For this reason, the movable cam cylinder 16 moves forward with a movement amount larger than the movement amounts of the retractable cylinder 12 and the first rectilinear cylinder 13.

  Further, the second rectilinear cylinder 14 has the second projecting portion 51 engaged with the first rectilinear groove 46 and the second engaging portion 52 engaged with the outer peripheral groove portion 62 of the movable cam cylinder 16. The moving cam cylinder 16 does not follow the rotation of the moving cam cylinder 16 in the circumferential direction, but only follows the movement of the moving cam cylinder 16 to the front, and moves forward by the same movement amount as the moving cam cylinder 16.

  At the same time, the first group lens holding frame 15 has the pin 56 engaged with the second rectilinear groove 53 of the second rectilinear cylinder 14 and the cam follower 57 engaged with the outer peripheral cam groove 63 of the movable cam cylinder 16. It does not follow the rotation of the movable cam cylinder 16 in the circumferential direction, but only follows the movement of the movable cam cylinder 16 in the forward direction, and moves according to the shape of the non-imaging area 72 of the outer cam groove 63 shown in FIG. The cam cylinder 16 moves forward according to the amount of rotation. For this reason, the first lens group holding frame 15 moves forward with a movement amount larger than the movement amount of the movable cam cylinder 16.

  Further, in the third rectilinear cylinder 17, the third engaging portion 87 is engaged with the inner peripheral groove portion 64 of the movable cam cylinder 16 and the third projecting portion 86 is engaged with the first rectilinear groove 46 of the first rectilinear tube 13. Therefore, it does not follow the rotation of the moving cam cylinder 16 in the circumferential direction, and only follows the movement of the moving cam cylinder 16 forward, and moves forward with the same amount of movement as the moving cam cylinder 16. Moving.

  The second group lens holding frame 18 has the cam follower 96 engaged with the first inner peripheral cam groove 65 of the moving cam cylinder 16 through the first rectilinear hole 88 of the third rectilinear cylinder 17. According to the amount of rotation of the movable cam cylinder 16 according to the shape of the non-imaging area 75 shown in FIG. 7 of the first inner circumferential cam groove 65 due to the rotation of the movable cam cylinder 16. And move forward. Therefore, the second group lens holding frame 18 moves forward with a movement amount larger than the movement amount of the movable cam cylinder 16.

  Similarly, the third group lens holding frame 19 is configured so that the cam follower 112 is engaged with the second inner peripheral cam groove 66 of the moving cam cylinder 16 through the second rectilinear hole 89 of the third rectilinear cylinder 17. According to the shape of the non-imaging area 82 shown in FIG. 7 of the second inner peripheral cam groove 66 due to the rotation of the movable cam cylinder 16, the rotation amount of the movable cam cylinder 16 is not followed. Correspondingly, it moves rearward relative to the movable cam cylinder 16, and the pressing force for holding the shutter device 21 in the non-imaging position is released as the distance from the second group lens holding frame 18 increases. The lead portion 24a of the AF motor 24, which has moved relatively forward with respect to the fixed cam cylinder 11 and separated from the base plate portion 22 and has been inserted into the insertion hole 107, protrudes rearward from the insertion hole 107. .

  To summarize the above operations, the retractable cylinder 12 is rotated clockwise by the drive motor of the zoom optical system moving means 29, so that each cam follower 39, 57, 61, 96, 112 is Corresponding to the gradual movement of the non-imaging areas 35, 48, 72, 75, 82 to the respective imaging areas 36, 49, 73, 76, 83, the retractable cylinder 12 and the first rectilinear cylinder 13 are moved approximately equally. The moving cam cylinder 16 moves so as to gradually protrude forward from the collapsible cylinder 12, and the second rectilinear cylinder 14 and the third rectilinear cylinder 17 move approximately equal to the moving cam cylinder 16. The first group lens holding frame 15 moves so as to gradually protrude forward from the moving cam cylinder 16, and the second group lens holding frame 18 moves relatively forward in the third rectilinear cylinder 17. The third group lens holding frame 19 moves relatively rearward in the third rectilinear cylinder 17 so that the distance from the second group lens holding frame 18 increases and each second group convex shape Moves to relatively forward with respect to the fixed cam barrel 11 with the contact between the parts 92 and the contact portions 121 is released gradually.

  Then, each cam follower 39, 57, 61, 96, 112 transfers all the non-imaging regions 35, 48, 72, 75, 82 of the cam portion 28 to the end portions on the imaging region 36, 49, 73, 76, 83 side. With the AF motor 24 rotating the lead portion 24a and moving the focus lens holding frame 23 forward, the lens L1, the lens unit L2, the lens unit L3, and the focus of the zoom optical system 27 are moved. The lens L4 is disposed at a predetermined position, and the shutter ring 21 comes in contact with the third group flange portion 101 forward relative to the third group lens holding frame 19 by the biasing force of the coil spring 122. Up to the imaging position, that is, the lens L8 moves relatively rearward from the opening 115a of the shutter device 21 and the shutter 116 can be used, so that the digital camera 1 is ready for imaging.

  In this imaging enabled state, each imaging area 36, 49, 73, 76, 83 is driven by the drive motor of the zoom optical system moving means 29 rotating the retractable cylinder 12 clockwise or counterclockwise when viewed from the front. And the cam followers 39, 57, 61, 96 and 112, the lens holding frames 15, 18, and 19 are relatively moved back and forth to perform a zoom operation by the zoom optical system 27, and an AF motor. 24 rotates the lead portion 24a to appropriately move the focus lens L4 back and forth, and performs an image focusing operation by the zoom optical system 27 to form an image on the imaging surface of the image sensor 25 with a predetermined circuit. Convert it to an image.

  On the other hand, the retraction operation of the lens barrel 3 is performed by an operation reverse to the above-described operation.

  That is, after the lens barrel 3 is set to the wide-angle state shown in FIG. 1, the retractable cylinder 12 is rotated counterclockwise by the drive motor so that each cam follower 39, 57, 61, 96, 112 is rotated. In response to the gradual movement of the non-imaging areas 35, 48, 72, 75, 82 of the cam portion 28 to the end opposite to the imaging areas 36, 49, 73, 76, 83, the retractable cylinder 12 And the first rectilinear cylinder 13 moves rearward by substantially the same amount of movement, and the movable cam cylinder 16 moves rearward so as to gradually retract to the collapsible cylinder 12, and the second rectilinear cylinder 14 and the third rectilinear cylinder 17 moves rearward by a movement amount substantially equal to the moving cam cylinder 16, the first group lens holding frame 15 moves rearward so as to gradually retract to the moving cam cylinder 16, and the second group lens holding frame 18 It moves relatively backward in the third rectilinear cylinder 17.

  Then, the third group lens holding frame 19 moves relatively forward in the third rectilinear cylinder 17 and approaches the second group lens holding frame 18, and each second group convex portion 92 and each second group concave shape. The portions 93 are respectively fitted with the respective third group concave shape portions 103 and the respective third group convex shape portions 102 so that the respective second group convex shape portions 92 are brought into contact with the respective contact portions 121 so that the shutter device 21 holds the third group lens. The third group lens holding frame 19 is moved rearward relative to the fixed cam cylinder 11 and gradually moved backward so as to approach the frame 19, and is within the longitudinal dimension of the fixed cam cylinder 11. The tubes 12, 13, 14, 16, 17 and the lens holding frames 15, 18, 19 are retracted.

  Furthermore, each cam follower 39, 57, 61, 96, 112 moves each non-imaging area 35, 48, 72, 75, 82 of the cam portion 28 to the end opposite to the imaging areas 36, 49, 73, 76, 83. And the lens L1, the lens unit L2, the lens unit L3, and the focus lens L4 approach each other with a slight gap in a state where the AF motor 24 has moved the focus lens holding frame 23 toward the end. In addition, the shutter device 21 is pushed toward the third group lens holding frame 19 side to move to the non-imaging position until the coil spring 122 is completely contracted, and the shutter 116 is opened, and the lens group L3 is moved to the opening 115a. By fitting, the digital camera 1 enters a non-imaging state.

  As described above, according to the above-described embodiment, the shutter device 21 is supported by the third group lens holding frame 19 so as to be movable along the optical axis direction between the imaging position and the non-imaging position. Compared to the conventional case in which the lens holding frame is supported on the shutter device side while the distance in the optical axis direction between the lens group L3 and the shutter device 21 in the non-imaging mode is variable, for example, the lens barrel 3 A relative positional shift between the third group lens holding frame 19 and the shutter device 21 when an external force is applied can be suppressed, and the optical axis of the lens becomes difficult to move (rare is less likely to occur).

  That is, in the conventional case of supporting the lens holding frame on the shutter device, it is necessary to form a slight gap (clearance) in the portion supporting the lens holding frame so that the lens holding frame can be moved smoothly. If there is rattling in the part that supports the lens holding frame, the lens holding frame moves with respect to the shutter device and the optical axis due to vibration or the like, whereas the three groups as in the above embodiment. When the shutter device 21 is supported on the lens holding frame 19, there is rattling on the portion that supports the shutter device 21, and this causes the shutter device 21 to move relative to the third group lens holding frame 19. Also, the influence on imaging is reduced compared to the case where the third group lens holding frame moves relative to the optical axis.

  Further, guide holes 105 are respectively provided in the third group lens holding frame 19, and the shutter device 21 is supported by the guide holes 105 on the inner side of the outer peripheral edge of the third group lens holding frame 19. It can suppress that the outer diameter of becomes large.

  Furthermore, by providing a plurality of guide holes 105 substantially rotationally symmetrical with respect to the optical axis, the shutter device 21 can be stably supported with respect to the third group lens holding frame 19 without being inclined with respect to the optical axis.

  In the case where the rear end portion of the second group lens holding frame is in contact with the shutter device at a position overlapping the shutter in the optical axis direction, the force acting when the second group lens holding frame and the shutter device are in contact with each other is In contrast to the shutter blades of the shutter, which may be bent and deformed, in the above-described embodiment, the contact portion 121 on the shutter device 21 side is connected to the shutter 116 with the second group lens. By providing the holding frame 18 at a position that does not overlap in the contact direction with the second group convex portion 92, it is ensured that the shutter 116 is deformed by the contact between each second group convex portion 92 and each contact portion 121. Can be prevented.

  Further, by forming the contact portion 121 wider in the circumferential direction, the contact area between the second group convex shape portion 92 of the second group lens holding frame 18 and the contact portion 121 increases, and the shutter device 21 is pressed. Since the force is dispersed, the possibility of deforming the shutter blades of the shutter 116 can be further suppressed.

  In addition, the second group convex shape portion 92 and the contact portion 121 are provided at a plurality of locations in the circumferential direction, and the pushing direction of the shutter device 21 is guided by the guide hole 105, whereby the second group lens holding frame 18 is shuttered. The device 21 can be pushed stably in a balanced manner.

  The shutter device main body 115 of the shutter device 21 is formed in a D shape by providing a cut portion 117 in order to avoid interference with the lead portion 24a of the AF motor 24, so that the center of gravity of the shutter device 21 moves downward. Therefore, the shutter device 21 can be supported on the third group lens holding frame 19 more stably by biasing the guide hole 105 downward from the optical axis according to the position of the center of gravity.

  Furthermore, for example, in the conventional case where the focus lens is moved by a focus unit provided so as to be movable integrally with a shutter device located on the front side of the zoom lens, a lead screw or the like for moving the focus lens is used for zooming. It is necessary to form the lens barrel longer to allow it to act on the focus lens beyond the lens, and there is a risk of increasing the size of the lens barrel. To avoid this increase in size, the shutter device and the focus lens are close to each other. In contrast to this, in the above-described embodiment, the zoom optical system moving means 29 causes the shutter device 21 to be linked to the movement of the zoom optical system 27 between the imaging position and the non-imaging position. The focus lens L4 is disposed at a position relatively distant from the shutter device 21 by moving between the imaging position and the non-imaging position. Thus, it is possible to suppress variation in aberrations to image formation during the focusing operation while suppressing an increase in the size of the lens barrel 3.

  Further, the coil spring 122 provided between the third group lens holding frame 19 and the shutter device 21 enables the shutter device 21 to be moved from the non-imaging position to the imaging position, and the second group lens. The holding frame 18 and the shutter device 21 are attached to the coil spring 122 by abutting between the second group convex portion 92 and the abutting portion 121 in the non-imaging areas 35, 48, 72, 75, 82 of the cam portion 28. The lens barrel 3 is increased in size and the number of parts is suppressed by allowing the shutter device 21 to be moved toward the non-imaging position by pushing the shutter device 21 toward the third group lens holding frame 19 side against the force. Thus, the shutter device 21 can be easily moved between the imaging position and the non-imaging position, and the shutter device 21 can be held against the third group lens holding frame 19 by the urging force of the coil spring 122. Misalignment can be suppressed.

  When the second group lens holding frame 18 and the third group lens holding frame 19 are brought close to each other, each second group convex shape portion 92, each third group concave shape portion 103, and each second group concave shape portion 93, By forming the third group convex portions 102 so as to be combined, for example, each lens holding frame at the time of non-imaging as compared with the case where the second group lens holding frame and the third group lens holding frame are each formed into a cylindrical shape, for example. The thickness in the optical axis direction with respect to 18 and 19 can be reduced, and the total length of the lens barrel 3 when not imaged can be further shortened.

  In addition, during non-imaging, the shutter 116 opens and the lens group L3 is inserted into the opening 115a of the shutter device 21, so that the arrangement interval between the shutter device 21 and the second group lens holding frame 18 can be reduced, and the lens The total length of the lens barrel 3 when it is not imaged can be further shortened.

  Further, the dead space can be effectively utilized by supporting the shutter device 21 by the guide hole 105 formed in the dead space of the third group flange portion 101 of the third group lens holding frame 19. The shutter device 21 can be held by the third group lens holding frame 19 in a state where the increase in size is effectively suppressed.

  That is, the third group lens holding frame 19 that holds the lens unit L3 having the smallest diameter among the lenses constituting the zoom optical system 27 is compared with the first group lens holding frame 15 or the second group lens holding frame 18. Since a large dead space is formed around the third group holding portion 104 that holds the lens group L3, the shutter device 21 is supported by the third group lens holding frame 19, thereby providing a space for supporting the shutter device 21. There is no need to newly secure the lens barrel 3 and so on.

  Furthermore, since the beam width before and after the position where the chief ray intersects the optical axis is narrow, the outer diameter of each lens group L2, L3 arranged in the vicinity of the subsequent mounting corresponds to the beam width. Can be small.

  Further, since the non-imaging areas 35, 48, 72, 75, 82 of the cam portion 28 are formed by extending the imaging areas 36, 49, 73, 76, 83, each cam cylinder 11, 16, and There is no need to increase the size of the first straight cylinder 13 and the like, and a guide hole 105 for supporting the shutter device 21 on the third group lens holding frame 19 is also arranged inside the outer diameter of the second group lens holding frame 18. Therefore, the moving mechanism of the shutter device 21 can be configured while reliably suppressing the enlargement of the lens barrel 3.

  Further, by providing the lens barrel 3 as described above, when an external force is applied while the distance in the optical axis direction between the lens group L3 and the shutter device 21 during imaging and during non-imaging is variable. The movement of the optical axis of the lens group L3 can be suppressed to suppress the influence on the imaging, and the fluctuation of aberration to the image formation during the focusing operation can be suppressed, so that stable imaging can be performed.

  In the above embodiment, the lens barrel 3 can be used in correspondence with any imaging device other than the digital camera 1 or any optical device.

  The lens barrel 3 may be configured to be supported on the rear side of the second group lens holding frame 18 or may be configured to be disposed between the first group lens holding frame 15 and the second group lens holding frame 18. .

  Furthermore, the above configuration can be applied to a lens barrel such as a third group zoom lens or a fifth group zoom lens.

It is a longitudinal cross-sectional view which shows the wide angle state of the lens barrel of the imaging device of one embodiment of this invention. It is a longitudinal cross-sectional view which shows the telephoto state of a lens barrel same as the above. It is a longitudinal cross-sectional view which shows the retracted state of a lens barrel same as the above. It is an expanded view which shows a part outer periphery part of a lens-barrel same as the above. It is an expanded view which shows a part outer periphery part of a lens-barrel same as the above. It is an expanded view which shows a part outer periphery part of a lens-barrel same as the above. It is an expanded view which shows a part inner peripheral part of a lens-barrel same as the above. It is a disassembled perspective view which shows a part of lens barrel same as the above from the front side. It is a perspective view which shows a part of lens barrel same as the above from the front side. It is a disassembled perspective view which shows a part of lens barrel same as the above from the rear side. It is a perspective view which shows a part of lens barrel same as the above from the rear side.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Digital camera as an imaging device 2 Camera body as a housing 3 Lens barrel
18 Two-group lens holding frame as one lens holding frame
19 Three-group lens holding frame as the other lens holding frame
21 Shutter device as light shielding means
24 Autofocus motor as a means of moving the focus optical system
27 Zoom optical system
28 Cam part
29 Zoom optical system moving means
35, 48, 72, 75, 82 Non-imaging area as non-use area
36, 49, 73, 76, 83 Imaging area as use area
116 Shutter as shading plate
121 Contact part
122 Coil spring as biasing means
L2 Lens group as one lens optical system
L3 Lens group as the other lens optical system
L4 Focus lens as a focus optical system

Claims (4)

A lens barrel that is provided in the case and is drawn out from the case at the time of use and into the case when not in use;
Zoom optics,
Zoom optical system moving means for performing zoom operation by moving this zoom optical system along the optical axis direction;
A focus optical system that forms an image of subject light on the imaging surface;
A focus optical system moving means for performing a focus operation by moving the focus optical system along the optical axis direction;
A light shielding means for regulating the amount of light passing therethrough,
The zoom optical system moving means moves the zoom optical system to a position corresponding to each of when in use and when not in use, and in conjunction with the movement of the zoom optical system, moves the light shielding means from the position in use. A lens barrel that is moved to each position when in use. The zoom optical system
One and the other lens optical systems different from each other disposed back and forth in the optical axis direction;
One and the other lens holding frame for holding each of these lens optical systems,
The zoom optical system moving means includes a cam portion having a use area for zooming the zoom optical system and a non-use area for narrowing an interval between the one and other lens optical systems of the zoom optical system,
The light shielding means is disposed between the lens optical systems, and is supported so as to be movable between a use position and a non-use position with respect to the one lens holding frame.
A biasing means provided between the light shielding means and the one lens holding frame, and biasing the light shielding means from a non-use position to a use position;
2. The lens barrel according to claim 1, further comprising a contact portion that is provided on each of the other lens holding frame and the light shielding unit and contacts each other in the optical axis direction in the non-use area. The light shielding means includes a light shielding plate,
The contact portion on the light shielding means side is provided at a position that does not overlap with the light shielding plate in the contact direction with the contact portion on the other lens holding frame side. Lens barrel. A housing,
An imaging apparatus comprising: the lens barrel according to any one of claims 1 to 3 provided in the housing.

Images