JP2010156797A - Lens-barrel and imaging apparatus having the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lens-barrel with simple configuration having a lens frame for integrally holding a plurality of lens groups at predetermined intervals, and an independently movable lens group disposed between the plurality of lens groups, which are engaged with a common guide bar in moving. <P>SOLUTION: The lens-barrel includes: a first holding member (30) having a first engaging part (31) engaged with a guide shaft (52) and holding a first optical system (L2) and a second optical system (L4) different from the first optical system, so as to be integrally movable along the guide shaft; and a second holding member (40) having a second engaging part (41) engaged with the guide shaft and holding a third optical system (L3) disposed between the first optical system and the second optical system, so as to be movable independently of the first and second optical systems. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a lens barrel and an imaging apparatus provided with the lens barrel.

Conventionally, a guide bar type lens barrel configured such that a plurality of lens groups can be independently moved using a guide bar is known (for example, see Patent Document 1).
JP-A-6-94963

  The conventional guide bar system is configured such that each lens group moves independently. However, in such a conventional guide bar system, a lens frame that integrally holds a plurality of lens groups at a predetermined interval, and a lens group that is arranged between the plurality of lens groups and is independently movable It has not been proposed at all to configure such that they are moved by engaging with a common guide bar.

  An object of the present invention is to share a lens frame that integrally holds a plurality of lens groups at a predetermined interval with a simple configuration and a lens group that is arranged between the plurality of lens groups and that can be moved independently. An object of the present invention is to provide a lens barrel that can be configured to move by engaging with a guide bar, and an imaging apparatus including the lens barrel.

The present invention solves the above problems by the following means. In addition, in order to make an understanding easy, although the code | symbol corresponding to embodiment of this invention is attached | subjected and demonstrated, it is not limited to this.
The invention according to claim 1 has a first engagement portion (31) that engages with the guide shaft (52), and is different from the first optical system (L2) and the first optical system. A first holding member (30) for holding (L4) integrally movable along the guide shaft; and a second engagement portion (41) for engaging with the guide shaft; A second holding member (40) for holding a third optical system (L3) disposed between the system and the second optical system so as to be movable independently of the first and second optical systems; This is a lens barrel.
A second aspect of the present invention is the lens barrel according to the first aspect, wherein the first holding member (30) is spaced from the first engaging portion (31F) to the guide shaft. A third engagement portion (31R) to be engaged, and the second holding member (40) is engaged with the guide shaft at a distance from the second engagement portion (41F). A first engaging portion and a third engaging portion, and the second engaging portion and the fourth engaging portion are alternately engaged with the guide shaft (52). It is characterized by that.
Invention of Claim 3 is a lens-barrel of Claim 1 or 2, Comprising: The said guide shaft (52) is a said 2nd holding member (40) with respect to a said 1st holding member (30). The second engaging portion (41) is engaged with the guide shaft via a notch (35) provided in the first holding member.
The invention according to claim 4 is the lens barrel according to claim 3, wherein the second engaging portion (41) is separable from the second holding member (40). To do.
A fifth aspect of the present invention is the lens barrel according to the third or fourth aspect, wherein the first holding member (70) includes the second engaging portion (of the notch (75)). 41), reinforcing members (77, 78) are provided at positions not interfering with 41).
The invention according to claim 6 is the lens barrel according to claim 1 or 2, wherein the guide shaft (52) is connected to the second holding member (40) with respect to the first holding member (80). It is arranged on the same side.
A seventh aspect of the present invention is an imaging apparatus (1) comprising the lens barrel (20) according to any one of the first to sixth aspects.
Note that the configuration described with reference numerals may be improved as appropriate, or at least a part thereof may be replaced with another component.

  According to the present invention, a lens frame that integrally holds a plurality of lens groups at a predetermined interval with a simple configuration and a lens group that is disposed between the plurality of lens groups and that can move independently are shared. It is possible to provide a lens barrel and an imaging apparatus that can be configured to engage and move with the guide bar.

Embodiments of a lens barrel and an imaging apparatus according to the present invention will be described below with reference to the drawings.
FIG. 1 is a schematic view of a camera 1 including an imaging lens 20 as an embodiment of a lens barrel according to the present invention.

  In FIG. 1, an XYZ rectangular coordinate system is provided for ease of explanation and understanding. In this coordinate system, the direction toward the left as viewed from the photographer at the position of the camera when the photographer shoots a horizontally long image with the optical axis OA horizontal (hereinafter referred to as a normal position) is defined as the X plus direction. Further, the direction toward the upper side in the normal position is defined as the Y plus direction. Further, the direction toward the subject at the normal position is defined as the Z plus direction. The Z plus direction toward the subject in the Z direction is also called the front side, and the Z minus direction is also called the back side.

  The camera 1 of this embodiment is comprised by the camera main body 10 and the imaging lens 20, as shown in FIG. The imaging lens 20 includes a plurality of lens groups (L1 to L4) constituting a photographing optical system, and is detachably attached to the mount CM of the camera body 10. Thereby, the camera 1 can image | photograph by replacing | exchanging different imaging lenses 20 according to a use.

  The camera body 10 includes a quick return mirror 11, a viewfinder screen 12, a pentaprism 13, an eyepiece optical system 14, a shutter 15, an image sensor 16, a display device 17, and the like.

  The quick return mirror 11 is a mirror for causing an optical path of light (subject light) from the subject side that has passed through the imaging lens 20 to go straight toward the image sensor 16 or to bend toward the viewfinder screen 12. The camera body 10 is configured to be rotatable. In response to the release operation, the quick return mirror 11 moves to a retracted position (indicated by a two-dot chain line in FIG. 1) that does not prevent the subject light from entering the image sensor 16.

The finder screen 12 is a screen for forming a subject image reflected by the quick return mirror 11, and is disposed between the quick return mirror 11 and the pentaprism 13.
The pentaprism 13 is a prism having a substantially pentagonal cross-sectional shape, and is disposed on the upper part of the camera body 10 held in a lateral position. The pentaprism 13 guides the image formed on the finder screen 12 to the eyepiece optical system 14 as an erect image.

The eyepiece optical system 14 is an optical system for magnifying and observing a subject image that has become an erect image by the pentaprism 13, and is arranged on the back side (photographer side) of the pentaprism 13.
The shutter 15 opens and closes in response to a release operation, and controls the exposure time of subject image light that forms an image on the image sensor 16.

The image sensor 16 is a part that converts a subject image formed by the photographing optical system into an electric signal, and is configured by a photodiode, a CCD, a CMOS, or the like. The imaging element 16 is provided on the back side (the right side shown in FIG. 1) inside the camera body 10 with the light receiving surface orthogonal to the optical axis OA.
The display device 17 is configured by a display panel such as a liquid crystal provided on the back side (photographer side) outside the camera body 10. The display device 17 displays a photographed image, information relating to photographing such as an exposure time, and the like on the display panel.

  In the camera 1 configured as described above, when a shutter button (not shown) is pressed (release operation), the quick return mirror 11 moves to the retracted position. The shutter 15 opens and closes in response to the release operation, and causes the image sensor 16 to expose subject image light for a predetermined time. Further, the image sensor 16 converts the subject image light into an electrical signal and images it. Image data captured by the image sensor 16 is recorded in a recording unit (not shown).

  Next, the imaging lens 20 will be described.

  The imaging lens 20 includes a zoom operation ring 22 at the tip of a cylindrical outer cylinder 21. On the inner peripheral side of the zoom operation ring 22, a first group barrel 23, a cam barrel 24, and a fixed barrel 25 that hold the first lens unit L1 are disposed.

  The cam barrel 24 is provided such that it can rotate relative to the fixed barrel 25 and cannot move in the optical axis OA direction (Z-axis direction), and is rotated by the rotation of the zoom operation ring 22. Yes.

  A lens inner cylinder 30 that holds the second lens group L2 and the fourth lens group L4 is disposed on the inner peripheral side of the fixed barrel 25. A lens mount LM is fixed to the rear side end of the fixed barrel 25.

  The lens inner cylinder 30 has a cylindrical shape, and the second lens group L2 is attached to the front end thereof, and the fourth lens group L4 is attached to the rear end thereof.

  A third lens barrel 40 that holds the third lens unit L3 is disposed on the inner peripheral side of the lens inner tube 30.

  The first group lens barrel 23, the lens inner cylinder 30, and the third group lens barrel 40 are each provided so as to be movable in the optical axis OA direction (Z-axis direction). Although the detailed configurations of the first group barrel 23, the lens inner barrel 30 and the third group barrel 40 are not shown, they are linked to the cam barrel 24 so as to be interlocked with each other by a cam groove and a follower. As a result, the first group barrel 23, the lens inner barrel 30 and the third group barrel 40 are moved and operated in the direction of the optical axis OA in a predetermined relationship by the rotation of the cam barrel 24.

The imaging lens 20 configured as described above has the first lens group L1, the lens inner cylinder 30 (the second lens group L2 and the fourth lens group L4), and the third lens group L3 by rotating the zoom operation ring 22. Move in a predetermined relationship, and the combined focal length changes. Further, the lens inner cylinder 30 and the third group lens barrel 40 in the imaging lens 20 are guided by a guide member 50 provided in the fixed lens barrel 25 and independently in the optical axis OA direction (Z-axis direction). It is supposed to move. As described above, the lens barrel of the present embodiment includes the lens inner cylinder 30 that integrally holds a plurality of lens groups at a predetermined interval, and the third group barrel 40 that is disposed therebetween and can move independently. Is configured as a nested guide bar system that engages with a common guide member 50.
(First embodiment)

Next, the configuration of the lens inner cylinder 30 and the third group barrel 40, which is the first embodiment of the present invention, will be described with reference to FIGS.
FIG. 2 is a plan view of the lens inner cylinder 30. 3 is a cross-sectional view taken along line AA of FIG. 2 showing a cross section of the lens inner cylinder 30 in the direction along the optical axis OA. 4A and 4B are views showing a cross section of the lens inner cylinder 30 in a direction orthogonal to the optical axis OA. FIG. 4A is a cross-sectional view taken along the line BB in FIG. 3, and FIG. is there.

  The guide member 50 includes an annular support ring 51 (see FIG. 1) and two guide bars 52 (52U, 52L) fixed to the support ring 51.

  The guide bar 52 has a round bar shape with a predetermined diameter, and is formed of a material having rigidity such as a stainless alloy. The two guide bars 52 (52U, 52L) are each fixed to the support ring 51 at one end. The two guide bars 52 (52U, 52L) are arranged at two locations on the same circumference that divide the circumferential direction of the support ring 51 into two equal parts (that is, positions separated by 180 °).

  The guide member 50 is integrally fixed to the fixed barrel 25 with a support ring 51 interposed between the fixed barrel 25 and the lens mount LM. Thus, the two guide bars 52 (52U, 52L) are provided in parallel with the optical axis OA between the inner peripheral surface of the fixed barrel 25 and the outer peripheral surface of the lens inner tube 30, respectively. The guide bar 52 has a length over the entire length direction of the fixed barrel 25, and the tip of the guide bar 52 is fitted to the end of the fixed barrel 25 on the subject side.

  The lens inner cylinder 30 has a cylindrical shape with a predetermined thickness, and is formed of metal, plastic, or the like. As described above, the lens inner cylinder 30 has the second lens group L2 attached to the front end thereof and the fourth lens group L4 attached to the rear end thereof. In addition, a third lens barrel 40 is disposed inside the lens inner cylinder 30 so as to be movable in the direction of the optical axis OA.

  Although a detailed configuration is not shown, the lens inner cylinder 30 is formed in a divided state in the direction of the optical axis OA, and the third group lens barrel 40 is accommodated therein and integrally assembled.

  A pair of front and rear slide bearing portions 31F and 31R project from the outer peripheral surface of the lens inner cylinder 30 at positions corresponding to the two guide bars 52 (52U and 52L). In addition, guide openings 35 and 36 for guiding and operating a third group lens barrel 40 to be described later are formed at predetermined positions of the lens inner cylinder 30.

  One slide bearing portion 31 </ b> F is provided in the vicinity of the front end portion of the lens inner cylinder 30, and the other slide bearing portion 31 </ b> R is provided in the vicinity of the rear end portion of the lens inner cylinder 30. That is, the slide bearing portion 31F and the slide bearing portion 31R are arranged at a predetermined interval in the optical axis OA direction.

  The slide bearing portions 31F and 31R are formed with a predetermined thickness in the direction of the optical axis OA, and are provided with bearing holes into which the guide bar 52 is slidably fitted with a predetermined fitting tolerance.

  The slide bearing portions 31F and 31R are fitted to the guide bar 52. Thereby, the lens inner cylinder 30 moves along the guide bar 52 inside the fixed barrel 25. In other words, the lens inner cylinder 30 is guided by the guide bar 52 and is provided so as to move in the direction of the optical axis OA that is the extending direction of the guide bar 52 without rotating.

  Note that the portion of the fixed barrel 25 corresponding to the movement area of the slide bearing portions 31F and 31R accompanying the movement of the lens inner tube 30 is opened so as not to prevent the movement of the slide bearing portions 31F and 31R. In the present embodiment, the center position of the guide bar 52 substantially coincides with the outer peripheral surface of the lens inner cylinder 30. For this reason, a concave portion having an arcuate cross section corresponding to the peripheral surface of the guide bar 52 is formed in the outer peripheral surface portion of the lens inner cylinder 30 where the guide bar 52 is disposed. As a result, the arc-shaped concave portion is also guided by the guide bar 52 and contributes to more stable movement of the lens inner cylinder 30.

  The movement of the lens inner cylinder 30 is performed via the cam cylinder 24 that is rotationally driven by the rotation operation of the zoom operation ring 22 as described above. That is, although not shown in detail, a cam follower projecting from the outer peripheral surface of the lens inner cylinder 30 is fitted in a cam groove formed in the cam cylinder 24, and the cam follower is fitted by rotation of the cam cylinder 24. Is configured to be displaced in the direction of the optical axis OA. As a result, the cam follower is moved in the direction of the optical axis OA by the rotation of the cam cylinder 24, and the lens inner cylinder 30 is moved in the direction of the optical axis OA.

  As described above, the third lens barrel 40 that holds the third lens unit L3 is disposed inside the lens inner tube 30.

  The third group lens barrel 40 has a disk shape with a predetermined thickness, and includes slide blocks 41 and 42 at outer peripheral portions corresponding to the two guide bars 52 (52U and 52L) on the outer periphery thereof.

  In FIG. 3, the slide block 41 corresponding to the upper guide bar 52U includes bearings 41F and 41R at both ends of the mounting substrate 41A in the optical axis OA direction.

  As shown in FIG. 3, the mounting substrate 41 </ b> A of the slide block 41 is formed in a plate shape whose planar shape is substantially rectangular and whose thickness is thinner than the thickness of the lens inner cylinder 30. The inner peripheral surface (side facing the outer peripheral surface of the third group lens barrel 40) of the mounting substrate 41A has an arc shape corresponding to the outer peripheral surface of the third group lens barrel 40.

  The bearings 41F and 41R of the slide block 41 are provided so as to protrude from the mounting substrate 41A in the circumferential direction (lower side in FIG. 3) and the outer circumferential direction (left side in FIG. 5B). Both bearings 41F and 41R are formed with a predetermined thickness in the direction of the optical axis OA, and are provided with bearing holes into which the guide bar 52U is slidably fitted with a predetermined fitting tolerance.

  One bearing 41 </ b> F is disposed at the front edge portion of the mounting substrate 41 </ b> A. Further, the other bearing 41R is disposed at the edge on the back side of the mounting substrate 41A. That is, both bearings 41F and 41R are arranged at a predetermined interval in the direction of the optical axis OA. The distance between the bearings 41F and 41R is set so that the third group barrel 40 can move stably along the guide bar 52U.

  The slide block 41 is fixed to the outer peripheral surface of the third group lens barrel 40 by screws 45 penetrating the mounting substrate 41A. The slide block 41 attached to the third group lens barrel 40 is located inside the guide opening 35 of the lens inner tube 30. The bearings 41F and 41R of the slide block 41 protrude outward from the outer peripheral surface of the lens inner cylinder 30, and are fitted to the guide bar 52U.

  In FIG. 3, the slide block 42 corresponding to the guide bar 52L located on the lower side includes one bearing 42B. The bearing 42B is formed with a predetermined thickness in the direction of the optical axis OA, and includes a bearing hole into which the guide bar 52L is slidably fitted with a predetermined fitting tolerance.

  The slide block 42 is fixed to the outer peripheral surface of the third group barrel 40 by screws 46. The bearing 42B protrudes outward from the outer peripheral surface of the lens inner cylinder 30 from the guide opening 36 of the lens inner cylinder 30, and is fitted to the guide bar 52L.

  As described above, the slide block 41 is fixed to the outer peripheral surface of the third group lens barrel 40 by the screw 45, and the slide block 42 is fixed to the outer peripheral surface of the third group lens barrel 40 by the screw 46. ing. By adopting such a structure, it is possible to easily assemble the slide blocks 41 and 42 to the third group lens barrel 40 even in a nested guide bar system.

  As described above, the guide openings 35 and 36 are formed at portions of the lens inner cylinder 30 corresponding to the slide blocks 41 and 42 in the third group lens barrel 40.

  As shown in FIG. 3, the guide openings 35 and 36 accommodate the slide blocks 41 and 42 and have sizes and shapes that allow the slide blocks 41 and 42 to move with the movement of the third group barrel 40. Is formed.

  3 and 4, the third group lens barrel 40 (third lens group L3) is most front side (subject side) with respect to the lens inner cylinder 30 (second lens group L2 and fourth lens group L4). The state located at is shown. This is the state on the most telephoto side (the side with the longest focal length) in the present embodiment. From this state, the third group lens barrel 40 (third lens group L3) is moved to the rear side (camera body 10 side: right side in FIGS. 3 and 4) to be on the wide angle side. The guide openings 35 and 36 are configured to be movable to the wide-angle end where the slide blocks 41 and 42 are defined. In other words, the movement range of the slide blocks 41 and 42 is defined by the size of the guide openings 35 and 36 in the direction of the optical axis OA.

  Slide blocks 41 and 42 provided in the third group lens barrel 40 are respectively positioned inside guide openings 35 and 36 in the lens inner tube 30.

  The bearings 41F and 41R of the slide block 41 protrude from the guide opening 35 to the outside of the lens inner cylinder 30 and are fitted to the guide bar 52U. The bearing 42B of the slide block 42 protrudes from the guide opening 36 to the outside of the lens inner cylinder 30 and is fitted to the guide bar 52L.

  Thereby, the third group lens barrel 40 is movable along the guide bar 52 inside the lens inner cylinder 30. That is, the third group lens barrel 40 is guided by the guide bar 52 and moves in the direction of the optical axis OA which is the extending direction of the guide bar 52 without rotating.

  The movement of the third group lens barrel 40 is performed by the cam cylinder 24 that is rotationally driven via the zoom operation ring 22 in the same manner as the movement of the lens inner cylinder 30 described above. That is, a cam follower projecting from the outer peripheral surface of the third group barrel 40 is fitted into the cam groove formed in the cam barrel 24, and the cam groove where the cam follower is fitted by the rotation of the cam barrel 24 is light. It is displaced in the direction of the axis OA. Thereby, the cam follower is moved in the direction of the optical axis OA by the rotation of the cam barrel 24, and the third group lens barrel 40 is moved in the direction of the optical axis OA. The movement of the third lens barrel 40 is different from the movement of the lens inner cylinder 30 operated by the same cam cylinder 24.

  In the moving configuration of the lens inner cylinder 30 and the third group lens barrel 40 configured as described above, the lens inner cylinder 30 (the second lens group L2 and the second lens group L2 and the second lens group L2) is rotated by the rotation of the cam cylinder 24 as the zoom operation ring 22 rotates. The fourth lens unit L4) and the third lens barrel 40 (third lens unit L3) are guided by one guide member 50 (guide bar 52) and moved. At that time, the lens inner cylinder 30 and the third group barrel 40 move independently of each other. That is, the lens inner cylinder 30 and the third group lens barrel 40 that move differently are guided by the same guide member 50.

Therefore, according to the first embodiment, compared with a configuration in which the configuration for guiding the movement of the lens inner cylinder 30 and the third group lens barrel 40 is separately provided, the number of parts requiring accuracy can be greatly reduced. it can. This makes it easy to keep the tilt and position (tilt and shift) of the lenses (second lens group L2, third lens group L3, and fourth lens group L4) within a design tolerance. Moreover, not only can the structure be simplified, but the outer diameter of the imaging lens 20 can be reduced, and the structure can be made highly rigid. In other words, it is possible to provide a nested guide bar type imaging lens 20 having a simple configuration but having high accuracy, small size, and high rigidity.
(Second Embodiment)

Next, a second embodiment of the present invention will be described with reference to FIGS.
FIG. 5 is a plan view of a lens inner tube 60 according to the second embodiment of the present invention. 6 is a cross-sectional view taken along the line DD of FIG. 6, showing a cross section in the direction along the optical axis OA of the lens inner cylinder 60. 7 is a cross-sectional view taken along the line EE of FIG. 6 showing a cross section of the lens inner cylinder 60 in a direction orthogonal to the optical axis OA.

  The second embodiment is different from the first embodiment in the arrangement of the slide bearing portions 61F and 61R in the lens inner tube 60. The basic configuration is the same as that of the first embodiment described above, and common portions are denoted by the same reference numerals and description thereof is omitted.

  A second lens group L2 and a fourth lens group L4 are mounted on the lens inner cylinder 60. In addition, a third lens barrel 40 that holds the third lens unit L3 is disposed inside the lens inner tube 60 so as to be movable in the optical axis direction.

  The lens inner cylinder 60 includes slide bearing portions 61F and 61R that fit into the guide bar 52. Thereby, the lens inner tube 60 is guided by the guide bar 52 and moves in the direction of the optical axis OA.

In addition, a guide opening 65 is formed in the lens inner cylinder 60.
The bearings 41 </ b> F and 41 </ b> R of the slide block 41 fixed to the third group lens barrel 40 protrude to the outer peripheral side of the lens inner tube 60 through the guide opening 65 and are fitted to the guide bar 52. Thereby, the third group lens barrel 40 is guided by the guide bar 52 and moves in the direction of the optical axis OA.

  The slide bearing portions 61F and 61R provided in the lens inner cylinder 60 are provided at two positions spaced apart by a predetermined distance in the extending direction of the guide bar 52 (in the direction of the optical axis OA).

  One slide bearing portion 61 </ b> F is provided at the opening edge on the front side of the guide opening 65. Further, the other slide bearing portion 61R is formed so as to protrude from the lower opening edge of the guide opening 65 in FIG. Accordingly, the slide bearing portion 61R is disposed between the bearings 41F and 41R before and after the slide block 41 in the third group barrel 40. That is, the pair of slide bearing portions 61F and 61R of the lens inner tube 60 and the pair of bearings 41F and 41R in the slide block 41 of the third group barrel 40 are arranged alternately.

  As shown in FIGS. 6 and 7, the rear-side slide bearing 61 </ b> R is disposed at a position where the third group lens barrel 40 is located on the most front side (telephoto side) with respect to the lens inner tube 60. The slide block 41 is set so as to be adjacent to the front side of the back side bearing 41B.

  According to the arrangement configuration of the slide bearing portions 61F and 61R in the lens inner cylinder 60 in the second embodiment, the slide bearing portion is not arranged at the opening edge portion on the back side of the guide opening 65. For this reason, the opening edge of the back side of the guide opening 65 can be set close to the back side end of the lens inner tube 60. As a result, the movement range of the slide block 41 (movement range of the third group barrel 40) can be increased. That is, conditions other than the arrangement position of the slide bearing portion 61R are completely equal to the movable distance X1 of the slide block 41 (third group barrel 40) shown in FIG. 3 in the first embodiment described above. It is possible to set a large movable distance X2 (X1 <X2) in the second embodiment shown in FIG.

That is, in the configuration of the first embodiment described above, if the movement stroke of the third group barrel 40 (third lens group L3) is to be increased, the interval between the bearings 41F and 41R of the slide block 41 must be reduced. Disappear. As a result, there is a risk that the smooth movement of the third lens barrel 40 may be impaired. However, in the configuration of the second embodiment, the stroke of the third lens barrel 40 can be increased without reducing the distance between the bearings 41F and 41R of the slide block 41 (without impairing smooth movement). .
(Third embodiment)

Next, a third embodiment of the present invention will be described with reference to FIGS.
8A and 8B are plan views of the lens inner cylinder 70 according to the third embodiment of the present invention, in which FIG. 8A is a state in which the third group barrel 40 is located on the telephoto side, and FIG. 8B is a third group barrel. A state 40 is moved to the wide-angle side. FIG. 9 is a cross-sectional view taken along line FF in FIG. 8 showing a cross section in the direction along the optical axis OA of the lens inner cylinder 70. 10 shows a cross section of the lens inner cylinder 70 in a direction orthogonal to the optical axis OA, (a) is a GG cross sectional view of FIG. 8, and (b) is a HH cross sectional view of FIG.

  The third embodiment is different from the second embodiment described above in the configuration of the guide opening 75. The basic configuration is the same as in the first embodiment and the second embodiment, and common portions are denoted by the same reference numerals and description thereof is omitted.

  A second lens group L2 and a fourth lens group L4 are mounted on the lens inner cylinder 70. In addition, a third lens barrel 40 that holds the third lens unit L3 is disposed inside the lens inner tube 70 so as to be movable in the optical axis direction.

  The lens inner cylinder 70 includes slide bearing portions 71F and 71R that fit into the guide bar 52. Thereby, the lens inner cylinder 70 is guided by the guide bar 52 and moves in the direction of the optical axis OA.

  The lens inner cylinder 70 is formed with a guide opening 75. The rear wall surface of the lens inner cylinder 70 corresponding to the guide opening 75 is cut out in a shape that does not interfere with the slide block 41 fixed to the third group lens barrel 40. Thereby, the guide opening 75 is open to the back side of the lens inner tube 70.

  Here, an end bridge portion 77 is provided across the guide opening 75 at the end of the lens inner tube 70 where the guide opening 75 opens.

  The end bridging portion 77 is a plate having a predetermined thickness having a predetermined width in the optical axis OA direction, and joins the circumferential edges of the guide opening 75. The end bridging portion 77 has a shape that bulges to the outer peripheral side as shown in FIG. Thereby, the end bridge portion 77 can accommodate the slide block 41 on the inner peripheral side without interfering with the bearing 41R of the slide block 41. Further, the end bridging portion 77 prevents a decrease in the rigidity of the lens inner cylinder 70 due to the opening of the guide opening 75 on the back side.

  The bearings 41 </ b> F and 41 </ b> R of the slide block 41 fixed to the third group lens barrel 40 protrude from the guide opening 75 to the outer peripheral side of the lens inner tube 70 and are fitted to the guide bar 52. Thereby, the third group lens barrel 40 is guided by the guide bar 52 and moves in the direction of the optical axis OA.

  The slide bearing portions 71F and 71R provided in the lens inner cylinder 70 are provided at two locations that are separated by a predetermined distance in the extending direction of the guide bar 52 (in the direction of the optical axis OA).

  One slide bearing portion 71 </ b> F is provided at the opening edge on the front side of the guide opening 75. Further, the other slide bearing portion 71 </ b> R is formed so as to protrude from the lower opening edge of the guide opening 75 in FIG. 9 to the inner side of the guide opening 75. Accordingly, the slide bearing portion 71R is disposed between the bearings 41F and 41R before and after the slide block 41 in the third group barrel 40. That is, the pair of slide bearing portions 71 and 72 of the lens inner cylinder 70 and the pair of bearings 41F and 41R in the slide block 41 of the third group barrel 40 are alternately arranged.

  Further, as shown in FIG. 10B, a central bridging portion 78 is provided across the guide opening 75 at the portion of the lens inner cylinder 70 where the slide bearing portion 71 </ b> R is formed.

  The central bridge portion 78 is formed in a plate shape having a width equal to that of the slide bearing portion 72 and a predetermined thickness, and connects the outer peripheral end of the slide bearing portion 72 and the edge of the guide opening 75. The central bridge portion 78 prevents a reduction in the rigidity of the lens inner cylinder 70 due to the opening of the guide opening 75, similarly to the end bridge portion 77 described above.

  According to the third embodiment, the guide opening 75 formed in the lens inner cylinder 70 is open to the back side of the lens inner cylinder 70. For this reason, the moving range of the slide block 41 (the moving range of the third group barrel 40) can be increased. That is, the third embodiment with respect to the movable distance X1 on the wide angle side shown in FIG. 3 in the first embodiment and the movable distance X2 on the wide angle side shown in FIG. 6 in the second embodiment. In the embodiment, as shown in FIG. 8, it is possible to set the movable distance X3 to the wide angle side to be large (X1 <X2 <X3).

  In addition, a decrease in the rigidity of the lens inner cylinder 70 due to the opening of the guide opening 75 on the back side is prevented by the end bridge portion 77 and the center bridge portion 78.

The present embodiment described above has the following common effects.
(1) The relatively moving lens inner cylinder 30 and the third group barrel 40 are guided by the same guide member 50. For this reason, compared with the structure which each provides the structure which guides the movement of the lens inner cylinder 30 and the 3rd group lens barrel 40, the site | part which requires an accuracy can be decreased greatly. Thereby, it becomes easy to keep the inclination and position of the lens within the allowable range in the design.
(2) Moreover, not only can the structure be simplified, but the outer diameter of the imaging lens 20 can be reduced and the structure can be made highly rigid. That is, it is possible to provide a nested guide bar type imaging lens 20 that has a simple configuration but has high accuracy, small size, and high rigidity.
(3) Since the slide block 41 is fixed to the outer peripheral surface of the third group lens barrel 40 by the screw 45, and the slide block 42 is fixed to the outer peripheral surface of the third group lens barrel 40 by the screw 46, the third The slide blocks 41 and 42 can be easily assembled to the group barrel 40.
(Deformation)

The present invention is not limited to the above-described embodiment, and various modifications and changes as described below are possible, and these are also within the scope of the present invention.
(1) In the above embodiment, the configuration in which the guide bar 52 of the guide member 50 is disposed on the outer peripheral side of the lens inner cylinder 30 is exemplified. However, the guide bar 52 may be disposed on the inner peripheral side of the lens inner cylinder 30. FIG. 11 is a cross-sectional view of the lens inner cylinder 30 in the direction of the optical axis OA in a configuration example in which the guide bar 52 is disposed on the inner peripheral side of the lens inner cylinder 80. In addition, the same code | symbol as 1st Embodiment is attached | subjected to each part in FIG.
In this configuration, an opening (a guide opening 35 or the like) from which a member for guiding the movement of the third group barrel 40 (the bearings 41F and 41R in the first embodiment) protrudes is formed in the lens inner cylinder 80. There is no need. For this reason, the lens inner cylinder 80 can be configured to be small and highly rigid.
(2) Further, in each of the above embodiments, the guide bar 52 is slidably fitted into the through holes of the slide bearing portions 31F, 31R, 61F, 61R, 71F, 71R and the bearings 41F, 41R, and the lens inner cylinder The configuration in which 30, 60, 70 and the slide block 41 (third group lens barrel 40) move along the guide bar 52 has been described. However, the structure that moves while being guided by the guide bar 52 is not necessarily a hole. For example, FIGS. 12A and 12B are the same as FIGS. 4A and 4B in the first embodiment. As shown in the corresponding figure, V-shaped bearing grooves 31VR and 41VF may be used. Alternatively, it may be U-shaped. In FIG. 12, the reference numerals of the parts other than the bearing grooves 31VR and 41VF are the same as those in FIG.
(3) In the above embodiment, the lens inner cylinders 30, 60, and 70 that hold the second lens group L2 and the fourth lens group L4, and the third group barrel 40 that holds the third lens group L3 are provided. The zoom lens in which the focal distance is changed by relatively moving has been described as an example. However, the present invention may be applied to a configuration in which a focusing lens for focus adjustment is moved.
(4) The embodiment and the modified embodiment can be used in appropriate combination, but detailed description thereof is omitted. Further, the present invention is not limited to the embodiment described above.

It is the schematic of a camera provided with the imaging lens as an embodiment of a lens barrel concerning the present invention. It is a top view of the lens inner cylinder concerning 1st Embodiment. It is AA sectional drawing of FIG. (A) is BB sectional drawing of FIG. 3, (b) is CC sectional drawing of FIG. It is a top view of the lens inner cylinder which concerns on 2nd Embodiment. It is DD sectional drawing of FIG. It is EE sectional drawing of FIG. It is a top view of the lens inner cylinder which concerns on 3rd Embodiment. (A) is a figure which shows the state which has the 3rd group lens barrel 40 in the telephoto side, (b) is a figure which shows the state which the 3rd group lens barrel 40 moved to the wide angle side. It is FF sectional drawing of FIG. (A) is GG sectional drawing of FIG. 8, (b) is HH sectional drawing of FIG. It is sectional drawing corresponding to FIG. 3 in 1st Embodiment which shows the example of a change of the arrangement structure by a guide bar. It is sectional drawing corresponding to FIG. 4 in 1st Embodiment which shows the example of a change of the guidance structure by a guide bar.

Explanation of symbols

  1: camera, 10: camera body, 20: imaging lens, 30: lens inner cylinder 30, 31F, 31R: slide bearing portion, 35, 36: guide opening, 40: third lens barrel, 41F, 41R: bearing 42B: bearing, 52: guide bar, 60: lens inner cylinder, 61F, 61R: slide bearing section, 65: guide opening section, 70: lens inner cylinder, 71F, 71R: slide bearing section, 75: guide opening section, 77: End bridge portion, 78: Center bridge portion, L2: Second lens group, L3: Third lens group, L4: Fourth lens group

Claims (7)

A first holding unit that has a first engaging portion that engages with the guide shaft, and holds the first optical system and a second optical system different from the first optical system so as to be integrally movable along the guide shaft. Members,
A second engaging portion that engages with the guide shaft, and a third optical system disposed between the first optical system and the second optical system is independent of the first and second optical systems; A second holding member that is movably held,
A lens barrel comprising: The lens barrel according to claim 1,
The first holding member has a third engagement portion that engages with the guide shaft at a distance from the first engagement portion,
The second holding member has a fourth engagement portion that engages with the guide shaft at a distance from the second engagement portion,
The lens barrel, wherein the first engaging portion and the third engaging portion and the second engaging portion and the fourth engaging portion are alternately engaged with the guide shaft. The lens barrel according to claim 1 or 2,
The guide shaft is disposed on the side opposite to the second holding member with respect to the first holding member,
The lens barrel, wherein the second engaging portion engages with the guide shaft through a notch provided in the first holding member. The lens barrel according to claim 3,
The lens barrel characterized in that the second engaging portion is separable from the second holding member. The lens barrel according to claim 3 or 4, wherein
The lens barrel according to claim 1, wherein the first holding member includes a reinforcing member at a position of the notch that does not interfere with the second engaging portion. The lens barrel according to claim 1 or 2,
The lens barrel, wherein the guide shaft is disposed on the same side as the second holding member with respect to the first holding member.   An imaging apparatus comprising the lens barrel according to claim 1.

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