JP2014115333A - Lens barrel, optical device, and image capturing device - Google Patents

Abstract

A cylindrical member constituting a lens barrel and a light shielding member are stably coupled and fixed.
A lens barrel 2 includes a second cam barrel 42 and a rectilinear barrel 43 that engages with the cam barrel and is movable in the optical axis direction. The light shielding plate 44 formed of a resin material is engaged with the rectilinear cylinder 43 and has a flat surface portion 44c extending in the outer diameter direction, and mainly enters through the gap between the cover cylinder 41 and the first group cylinder 51. Shield the light. A concave portion 42 f is formed at the end of the second cam cylinder 42 on the image plane side. The engaging portion 44b of the light shielding plate 44 is held in contact with the recess 42f. The position of the light shielding plate 44 in the optical axis direction is regulated by an elastically deformable locking portion 43 f formed on the rectilinear cylinder 43.
[Selection] FIG.

Description

  The present invention relates to a light blocking structure for a lens barrel.

2. Description of the Related Art Conventionally, various zoom lens barrels have been proposed that extend from an image pickup apparatus body during shooting and retract into the image pickup apparatus body when stored. A lens barrel having a retracting mechanism is configured to advance and retract in the optical axis direction by combining a plurality of rectilinear cylinders and a rotating cylinder. By storing each cylinder within the thickness of the imaging apparatus main body when not in use, the taking lens unit is protected and easy to carry.
In the multistage retractable lens barrel, many proposals have been made for shielding external light entering from a gap between the tubes. Patent Document 1 discloses a structure in which a light shielding member (light shielding sheet) fixed on an inner peripheral surface of a cylindrical member is elastically deformed to fill a gap between the cylinders and shield light. A double-sided tape or the like is used to fix the sheet-shaped light shielding member to the cylindrical member.

  As a structure for attaching the light shielding member to the cylindrical member to shield external light, there are a configuration in which a metal plate member is attached to the cylindrical member, and a configuration in which a resin light shielding member is attached to the cylindrical member. When a metal plate or a resin member is attached to the cylindrical member, a method using a double-sided tape is difficult to stably fix, so a holding shape portion for attachment is required. In the configuration disclosed in Patent Document 2, in a lens barrel having an internal rectilinear configuration in which a cam cylinder is sandwiched between a rectilinear plate and a rectilinear cylinder, a metal plate member is coupled to the rectilinear cylinder by a claw portion and fixed. Yes. The cylindrical member and the metal plate are fixed by engaging a claw-shaped protrusion provided on the inner wall of the straight cylinder with the metal plate. Since the metal plate is rigid and elastically deformable, the metal plate can be stably fixed by being connected to the claw portion of the inner wall of the cylindrical member using elasticity.

JP-A-8-286087 JP 2010-39286 A

The method of attaching the metal plate-like member to the cylindrical member disclosed in Patent Document 2 has a problem when applied to fixing the cylindrical member and the resin-made plate-like member. That is, since the resin member has a lower rigidity than the metal member and easily deforms, it is difficult to stably fix the member to the cylindrical member.
An object of the present invention is to stably couple and fix a cylindrical member and a light shielding member constituting a lens barrel.

  In order to solve the above problems, an apparatus according to the present invention includes a cylindrical member, a rectilinear member that engages with the cylindrical member and moves in the optical axis direction, and a light shield for preventing light from reaching the image sensor. A lens barrel including a member, wherein the light blocking member that engages with the rectilinear member is formed in the optical axis direction by the plane member extending in a direction orthogonal to the optical axis direction and the cylindrical member It has an engaging part which contacts a crevice.

  According to the present invention, the light shielding member can be stably fixed to the cylindrical member.

FIG. 14 is a cross-sectional view of a lens barrel illustrating the state of an imaging device in order to describe an embodiment of the present invention in conjunction with FIGS. It is sectional drawing at the time of imaging | photography of the lens barrel which concerns on embodiment of this invention. It is sectional drawing at the time of retraction of the lens-barrel which concerns on embodiment of this invention. 1 is an exploded perspective view of a lens barrel according to an embodiment of the present invention. 1 is a perspective view of an imaging apparatus according to an embodiment of the present invention. It is a disassembled perspective view of a fixed cylinder unit. It is a disassembled perspective view of a 1st cam cylinder unit. It is a disassembled perspective view of a 2nd cam cylinder unit. It is a disassembled perspective view of a 1st cam cylinder unit and a 2nd cam cylinder unit. It is a perspective view of a 2nd cam cylinder. It is a perspective view of a 1st group cylinder unit. It is a perspective view of a light shielding member. It is sectional drawing which shows the principal part of the lens barrel at the time of imaging | photography.

Hereinafter, a digital camera as an imaging apparatus including a lens barrel according to an embodiment of the present invention will be described with reference to FIGS. This lens barrel can be applied to an optical unit such as an interchangeable lens, an optical apparatus, and an imaging apparatus.
1 to 4 show a configuration example of an imaging apparatus (digital camera) including a lens barrel according to the present embodiment, and FIG. 5 is a perspective view of the imaging apparatus (digital camera) to which the lens barrel is applied. A digital camera 1 as an imaging apparatus includes a retractable lens barrel 2 having a three-stage configuration as a lens barrel, and the entire length of the lens barrel can be changed in the optical axis direction during shooting and when retracted. Hereinafter, the subject side in the optical axis direction is defined as the front, the imaging element side in the optical axis direction is defined as the rear, and the side closer to the optical axis of the photographing lens (the direction toward the optical axis in the direction orthogonal to the optical axis) is defined as the inner side. According to this definition, the positional relationship of each part of the imaging apparatus (digital camera 1) including the lens barrel according to the present embodiment will be described.

1 to 3 are sectional views of the lens barrel 2. FIG. 1 shows a wide (wide angle) state of the lens barrel 2, FIG. 2 shows a tele (telephoto) state of the lens barrel 2, and FIG. 3 shows a retracted state of the lens barrel 2. FIG. 4 is an exploded perspective view of the lens barrel 2 and shows each component when viewed from the front.
The lens barrel 2 is a collapsible lens barrel having a three-stage structure, and includes four photographing lens groups. The first group lens 11 is held by the first group cylinder 51. The second group lens 12 is held by a second group holder 72. The third group lens 13 is held by a third group holder 73. A shutter unit 73S is provided in the third group holder 73. The fourth group lens 14 is held by a fourth group holder 74 and is movable in the optical axis direction by the power of an AF (auto focus) motor unit 75 (see FIG. 4). Hereinafter, the configuration of each stage of the lens barrel 2 will be described in detail.

  FIG. 6 is an exploded perspective view of the fixed cylinder unit 20, and the fixed cylinder unit 20 includes a fixed cylinder 21 and a sensor holder 22. The fixed cylinder 21 has a rectilinear groove 21a and a cam groove 21b on the inner peripheral surface. The sensor holder 22 holds the image sensor 15, the motor 81, and the gear box 82. The motor 81 is a zoom drive source, and the output shaft of the motor 81 is connected to the gear box 82. The gear box 82 houses a plurality of gears that transmit power from the motor 81. In the gear box 82, the gear in the gear box 82 meshes with the output gear 83 in a state where the fixed cylinder 21 and the sensor holder 22 are coupled, and transmits power to the first cam cylinder 31 described later. Further, the sensor holder 22 includes an AF motor unit 75 that drives the fourth group holder 74.

FIG. 7 is an exploded perspective view of the first cam barrel unit 30 as the first stage of the lens barrel when viewed from the front. The first cam cylinder unit 30 includes a first cam cylinder 31, a rectilinear plate 32, a decorative ring 33, and a light shielding sheet 34.
The first cam cylinder 31 has a groove 31a and a rectilinear groove 31d formed on the inner peripheral surface. The groove 31a is a recess cut out along the direction around the optical axis at the inner peripheral surface near the rear end. The rectilinear groove 31d is formed on the inner peripheral surface of the first cam cylinder 31 along a direction parallel to the optical axis. A gear 31 b and a cam pin 31 c are provided on the outer peripheral surface of the first cam cylinder 31. The gear 31b meshes with the output gear 83 (see FIG. 6) to transmit power from the motor 81, and the first cam cylinder 31 rotates around the optical axis. The cam pin 31 c engages with a cam groove 21 b formed on the inner peripheral surface of the fixed cylinder 21. The first cam cylinder unit 30 moves in the optical axis direction along the cam groove 21b. A cam groove 31 e is formed on the inner peripheral surface of the first cam cylinder 31. The intersecting portion 31f is a portion where the rectilinear groove 31d and the cam groove 31e intersect. The front edge portion 31j of the first cam cylinder 31 is formed thinner than the other portions. On the outer peripheral surface of the front edge portion 31j, an engaging surface portion 31g protruding outward and a convex surface portion 31h provided so as to increase the thickness of the thin portion on the inner bottom surface of the cam groove 31e are formed.

The rectilinear plate 32 is a ring-shaped plate member, and includes a flange 32f and a plurality of rectilinear keys 32c and 32d provided perpendicular to the flange. The flange 32 f has engaging portions 32 a at three locations around the optical axis, and engages with the groove portion 31 a of the first cam cylinder 31. That is, the rectilinear plate 32 can move in the optical axis direction integrally with the first cam cylinder 31. Furthermore, a plurality of hole portions 32b are formed in the flange 32f, and a plurality of protrusion portions 32e facing outward from the outer peripheral edge portion are formed. The rectilinear plate 32 is guided linearly by engaging the projecting portion 32e and the rectilinear groove 21a of the fixed cylinder 21. The rectilinear key 32c of the rectilinear plate 32 is engaged with a rectilinear engaging portion 43g of a rectilinear cylinder 43 described later, and the rectilinear key 32d is engaged with a rectilinear engaging portion 41b of a cover cylinder 41 described later. As a result, the rectilinear cylinder 43 and the cover cylinder 41 are guided in a straight line.
A decorative ring 33 and a light shielding sheet 34 are attached to the front surface portion of the first cam cylinder 31. The decorative ring 33 is held by the first cam cylinder 31 by being fitted to the engagement surface portion 31 g of the first cam cylinder 31. The light shielding sheet 34 is sandwiched between the decorative ring 33 and the first cam cylinder 31, and is disposed inside the front rib 31 k of the first cam cylinder 31.

  FIG. 8 is an exploded perspective view of the second cam barrel unit 40 in the second stage of the lens barrel when viewed from the front. The second cam cylinder unit 40 includes a cover cylinder 41, a second cam cylinder 42, a rectilinear cylinder 43, a light shielding plate 44, and a decorative cap 45. FIG. 9 is an exploded perspective view when the first cam cylinder unit 30 and the second cam cylinder unit 40 are viewed from the rear. FIG. 10 is a perspective view when the second cam cylinder 42 is viewed from the rear.

  The cover cylinder 41 has a cam pin 41a on the outer peripheral surface of the rear end portion, and has a rectilinear engagement portion 41b (see FIG. 9) on the inner surface side. The cam pin 41 a engages with the cam groove 31 e of the first cam cylinder 31. The rectilinear engagement portion 41 b engages with the rectilinear key 32 d of the rectilinear plate 32. Three convex portions 41c protrude from the rib 41d formed in the circumferential direction at the rear end portion of the cover cylinder 41 in a direction approaching the optical axis, and the convex portions 41c are formed on the outer surface of the second cam cylinder 42. Engages with the groove 42e. As a result, the cover cylinder 41 moves integrally with the second cam cylinder 42 in the optical axis direction. Further, the cover cylinder 41 includes a decorative cap 45 at the front end thereof.

  The second cam cylinder 42 is a cylinder member having a cam groove 42a and a rotation transmission protrusion 42b on the outer surface. The cam groove 42 a engages with the cam pin 51 a of the first group cylinder 51. The engagement of the cam groove 42a and the cam pin 51a causes the first group cylinder 51 to advance and retreat along the locus of the cam groove 42a. The rotation transmission protrusion 42b is formed in a portion protruding outward from the rear end portion of the second cam cylinder 42. The rotation transmission protrusion 42 b is engaged with the rectilinear groove 31 d of the first cam cylinder 31. The second cam cylinder 42 rotates together with the first cam cylinder 31 by the engagement between the rotation transmission protrusion 42b and the rectilinear groove 31d. Cam grooves 42 c and 42 d are formed on the inner surface side of the second cam cylinder 42. The cam groove 42c engages with a cam pin 72a (see FIG. 4) of the second group holder 72. The engagement of the cam groove 42c and the cam pin 72a causes the second group lens 12 to advance and retract along the locus of the cam groove 42c. The cam groove 42 d engages with a cam pin 73 a (see FIG. 4) provided on the base plate of the third group holder 73. Due to the engagement of the cam groove 42d and the cam pin 73a, the third lens group 13 advances and retreats along the locus of the cam groove 42d.

  The rectilinear cylinder 43 serving as a rectilinear member has a rectilinear guide groove 43 a that guides the second group holder 72 in a straight manner and a rectilinear guide groove 43 b that guides the third group holder 73 in a straight line. The rectilinear cylinder 43 has a flange 43c at the front end, and has a rectilinear key part 43d for performing rectilinear guide of the first group cylinder 51 on the outer periphery of the flange 43c. A plurality of protrusions 43e are provided on the outer peripheral surface near the rear end of the rectilinear cylinder 43, and each of the protrusions 43e engages with the rear end face of the recess 42f (see FIG. 10) of the second cam cylinder 42. Further, a plurality of locking portions 43f are formed in a portion near the rear end of the straight cylinder 43, and each locking portion 43f has a locking claw at the rear end. The rectilinear cylinder 43 is held by the flange 43c and the protrusion 43e with respect to the second cam cylinder 42, and moves in the optical axis direction integrally with the second cam cylinder 42.

  The light shielding plate 44 is an annular light shielding member, and has a plurality of engaging portions 44 a with the rectilinear cylinder 43. These engaging portions 44 a are formed at predetermined angular intervals on the inner peripheral portion of the light shielding plate 44, and engage with the locking portions 43 f of the rectilinear cylinder 43, respectively. The light shielding plate 44 is held by the rectilinear cylinder 43 by engaging the engaging portion 44a and the locking portion 43f. The detailed shape of the light shielding plate 44 is shown in FIG. In addition to the four engaging portions 44a, the light shielding plate 44 has a rib-like engaging portion 44b protruding forward from the inner peripheral portion. The outer peripheral portion has a flat portion (flat light shielding surface portion) 44c extending in a direction orthogonal to the optical axis direction and a plurality of holes 44d through which the straight key 32d of the straight plate 32 passes.

  FIG. 11 is a perspective view showing details of the first group cylinder unit 50. The first group cylinder unit 50 includes a first group cylinder 51, a barrier blade 52 (see FIG. 4), and a first group cover 53. A plurality of portions projecting rearward are provided on the inner peripheral surface of the first group cylinder 51 and have cam pins 51 a that engage with the cam grooves 42 a of the second cam cylinder 42. Further, the rectilinear guide groove 51 b formed along the direction parallel to the optical axis engages with the rectilinear key portion 43 d of the rectilinear cylinder 43 to perform rectilinear guide of the first group cylinder 51. The first group cylinder unit 50 advances and retreats along the locus of the cam groove 42a in a state where the linear guide groove 51b and the linear key portion 43d are engaged. The barrier blade 52 is configured to open an opening when the imaging apparatus (digital camera 1) is in use and close the opening when the imaging apparatus is retracted. The barrier blade 52 may be configured to open the opening in the use state of the imaging apparatus (digital camera 1), increase the size of the opening, and reduce the size of the opening without completely closing the opening. .

  In the imaging apparatus configured as described above, the light shielding plate 44 is engaged with and held by the rectilinear cylinder 43. The light shielding plate 44 prevents light entering from the gap between the cover cylinder 41 and the first group cylinder 51 from reaching the image sensor 15 by the flat surface portion 44c.

FIG. 13 is a cross-sectional view showing the main part of the lens barrel at the time of photographing, and shows a state in which the light shielding plate 44 is incorporated in the lens barrel.
The second cam cylinder 42 has cam grooves 42c and 42d on the inner side, and has a recess 42f at a position where these cam grooves are not arranged at the inner rear end (portion on the image surface side). . The engaging portion 44b from which the light shielding plate 44 protrudes enters the concave portion 42f, and comes into contact with the concave portion 42f. In this way, the concave portion 42f is provided at one end of the second cam cylinder 42, and the thickness of the engaging portion 44b is increased by using the space to increase the inner peripheral portion of the light shielding plate 44, thereby increasing the rigidity of the light shielding plate 44. Can be increased. In the holding structure of the light shielding plate 44 with respect to the rectilinear cylinder 43, the engaging portion 43f of the rectilinear cylinder 43 is used, and the engaging portion 43f can be elastically deformed in a direction perpendicular to the optical axis. Therefore, when the light shielding plate 44 is assembled to the rectilinear cylinder 43, the light shielding plate 44 can be easily assembled by attaching it in the optical axis direction from the rear. After the assembly, the claw portion of the locking portion 43f formed on the rectilinear cylinder 43 restricts the position of the light shielding plate 44 in the optical axis direction with respect to the rectilinear cylinder 43 and is stably held.

The first group cylinder 51 (first linear cylinder) is inserted into the second cam cylinder 42 and the cover cylinder 41 (second linear cylinder) disposed outside from the front in the optical axis direction. It is. According to such a structure, the convex part 41c is engaged with the groove part 42e in the process of incorporating the cover cylinder 41 into the second cam cylinder 42 from the front. Thereafter, a step of incorporating the first group cylinder 51 from the front with respect to the second cam cylinder 42 and engaging the cam groove 42a with the cam pin 51a is performed. Therefore, assembly becomes easy.
Further, in the present embodiment, the light shielding plate 44 is made of a resin material, and has a higher degree of freedom in designing the shape than a metal light shielding member, so that a stable holding structure can be realized relatively easily.
As mentioned above, although preferable embodiment of this invention was described, this invention is not limited to these embodiment, A various deformation | transformation and change are possible within the range of the summary. For example, although the digital camera has been described as the imaging apparatus according to the present embodiment, the imaging apparatus may be an optical device such as binoculars or a telescope, a digital video camera, or a camera-equipped mobile phone.

1. Digital camera (imaging device)
2 ... Lens barrel 41 ... Cover cylinder (second rectilinear cylinder)
42 ... 2nd cam cylinder (cylinder member)
42d ··· Cam groove 42f ··· Recessed portion 43 ··· Linear tube (straight member)
43f... Locking portion 44...

Claims (8)

A lens barrel that includes a cylindrical member, a linear member that engages with the cylindrical member and moves in the direction of the optical axis, and a light shielding member for preventing light from reaching the imaging device,
The light shielding member that engages with the rectilinear member has a flat portion that extends in a direction orthogonal to the optical axis direction, and an engaging portion that abuts against a recess formed in the optical axis direction by the cylindrical member. Characteristic lens barrel.   2. The lens according to claim 1, wherein the cylindrical member has a cam groove on an inner peripheral surface, and the concave portion is provided at an end on the image surface side where the cam groove is not formed. A lens barrel.   3. The lens barrel according to claim 1, wherein a position of the light shielding member in an optical axis direction is restricted by an elastically deformable engaging portion formed on the rectilinear member. A first rectilinear cylinder disposed outside the cylinder member;
A second rectilinear cylinder disposed outside the first rectilinear cylinder,
4. The lens barrel according to claim 1, wherein the first rectilinear tube is inserted from the subject side along the optical axis direction and engages with the tube member. 5.   5. The lens barrel according to claim 1, wherein the engaging portion of the light shielding member has a thickness in the optical axis direction larger than that of the planar portion.   The lens barrel according to claim 1, wherein the light shielding member is formed of a resin material.   An optical apparatus comprising the lens barrel according to any one of claims 1 to 6.   An imaging apparatus comprising the lens barrel according to claim 1.

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