JP2014095828A - Lens barrel and image capturing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a retractable lens barrel which comprises a bent-type photographic optical system formed by a plurality of lens groups L1, L2 and offers reduced thickness by employing a simple movement mechanism of the lens groups and a prism 32.SOLUTION: A lens barrel of the present invention is configured such that, when shifting from a shooting position to a retracted position, a first lens group L2 moves in a direction of a first optical axis A and in a direction of a second optical axis B while a prism 32 moves in the direction of the second optical axis B, by which the first lens group L2 and the prism 32 are accommodated in a cylindrical body 7, with a portion of the prism 32 overlapping with the first lens group L2 looking from the direction of the first optical axis A in the retracted position.

Description

  The present invention relates to a lens barrel mounted on an imaging apparatus such as a digital still camera or a digital video camera, and more particularly to a retractable lens barrel provided with a bent type imaging optical system composed of a plurality of lens groups.

  As a lens barrel mounted on an imaging apparatus such as a digital still camera or a digital video camera, a lens barrel provided with a bending type imaging optical system (hereinafter referred to as a “bending imaging optical system”) composed of a plurality of lens groups. It has been known. In the bent photographing optical system, since it is not necessary to arrange a plurality of lens groups on a straight line, the total length required in the optical axis direction of the optical system can be shortened, and thereby the imaging apparatus can be thinned.

  As an imaging apparatus that constitutes such a bending imaging optical system, for example, an imaging apparatus is disclosed in which a light beam transmitted through a lens group on the subject side is bent 90 degrees by a prism and guided to another lens group (patent). Reference 1). In this imaging device, the prism and the second lens group disposed closest to the object side of the prism are viewed from the incident direction, and are different directions inside the cylindrical member that holds the first lens group. And the first lens group is retracted. In the imaging apparatus of Patent Document 2, the reflecting member is rotated in contact with any one of the first lens group lens frame, the second lens group lens frame, the cam cylinder, and the intermediate cylinder, and the lens group on the object side from the reflecting member. Retract.

JP 2009-181102 A JP 2009-169243 A

  However, in the technique disclosed in Patent Document 1, the prism and the second lens group are rotated in different directions inside the cylindrical member that holds the first lens group when viewed from the incident optical axis direction. Therefore, the outer diameter of the lens barrel including the cylindrical member that holds the first lens group may be increased.

  However, in the technique disclosed in Patent Document 2, since the reflecting member is rotated and then disposed at the approximate center of the intermediate cylinder, the lens group or the lens group lens frame on the object side from the reflecting member is placed in the intermediate cylinder when retracted. There is no degree of freedom of arrangement inside the lens barrel, and the outer diameter of the lens barrel including the intermediate cylinder may be increased.

In order to achieve the above object, the present invention provides a first lens group disposed in a first optical axis direction and a light beam incident from the first optical axis direction in a direction different from the first optical axis. A lens barrel comprising: a prism that is bent in the second optical axis direction extending to the first optical axis; and a cylindrical body that moves in the first optical axis direction as the first lens group moves.
The first lens group moves in the second optical axis direction when transitioning from the photographing state to the retracted state, and the prism moves the second light when transitioning from the photographing state to the retracted state. The first lens group and the prism are housed in the cylindrical body in the retracted state by moving in a direction different from the first lens group in the axial direction.
As viewed from the first optical axis direction, a part of the prism is superimposed on the first lens group.

Further, the present invention provides a first lens group disposed in the first optical axis direction and a second light beam extending from the first optical axis direction in a direction orthogonal to the first optical axis. A lens barrel comprising: a prism that is bent in the optical axis direction; and a cylindrical body that moves in the first optical axis direction as the first lens group moves.
When the first lens group shifts from the photographing state to the retracted state, the first lens group moves in the second optical axis direction by rotating about the first optical axis,
When the prism transitions from the photographing state to the retracted state, the prism rotates with the third optical axis orthogonal to the first optical axis and the second optical axis as the second optical axis. The direction of movement is different from that of the first lens group.

  According to the present invention, it is possible to provide a lens barrel that can be reduced in diameter and thinned by using a bent photographing optical system.

FIG. 3 is a cross-sectional view of a lens barrel according to an embodiment of the present invention in a retracted state and a cross-sectional view in a photographing state. 1 is an assembled perspective view of a lens barrel according to an embodiment of the present invention. It is a disassembled perspective view of the 1st optical axis unit of the lens-barrel concerning the Example of this invention. It is a disassembled perspective view of the 2nd optical axis unit of the lens barrel concerning the Example of this invention. FIG. 2 is an assembled perspective view of a second group unit of a lens barrel according to an embodiment of the present invention. It is a disassembled perspective view of 2 group unit of the lens-barrel concerning the Example of this invention. It is an assembly perspective view of the 3 group unit of the lens barrel concerning the Example of this invention. It is a disassembled perspective view of the 3 group unit of the lens barrel concerning the Example of this invention. It is sectional drawing of the 3 group unit of the lens barrel concerning the Example of this invention. It is a rear view at the time of the imaging | photography state of the 2nd optical axis unit of the lens barrel concerning the Example of this invention. It is operation | movement explanatory drawing ((a) imaging | photography state-(e) retracted state) at the time of the retracted state of the 1st optical axis unit of the lens barrel concerning the Example of this invention. It is operation | movement explanatory drawing at the time of the retracted state of the 2 group unit of the lens barrel concerning the Example of this invention ((a) imaging | photography state-(c) retracted state). 1 is a perspective view of a fixed base plate of a lens barrel according to an embodiment of the present invention. It is operation | movement explanatory drawing at the time of the retracted state of the 3 group unit of the lens barrel concerning the Example of this invention ((a) imaging | photography state-(d) retracted state). It is a perspective view of the straight advance cylinder of the lens barrel concerning the Example of this invention. It is a side view of the 3 group unit of the lens barrel concerning the reference example of this invention. It is a side view of the 3 group unit of the lens barrel concerning the reference example of this invention. It is a front view of the 2nd optical axis unit of the lens barrel concerning the Example of this invention. It is sectional drawing of the positioning part of the 3rd group baseplate of the 3rd group unit concerning the Example of this invention. It is sectional drawing of the steadying part of the 3rd group baseplate of the 3rd group unit concerning the Example of this invention. It is sectional drawing at the time of the retracted state of the 1st optical axis unit of the lens-barrel concerning the Example of this invention. It is sectional drawing at the time of the imaging | photography state of the 1st optical axis unit of the lens barrel concerning the Example of this invention. FIG. 6 is an explanatory diagram of the entrance of a light beam in a lens barrel according to a reference example of the present invention. FIG. 6 is an explanatory diagram of the entrance of a light beam in a lens barrel according to a reference example of the present invention.

  DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a retractable lens barrel equipped with a bending type imaging optical system used in an imaging apparatus that is a digital still camera according to the present invention will be described below in detail with reference to the accompanying drawings.

  FIG. 1A is a cross-sectional view of the lens barrel according to the embodiment of the present invention in the retracted state (stored state), and FIG. 1B is a cross-sectional view of the lens barrel in the photographing state. 2 is an assembly perspective view of the lens barrel, FIG. 3 is an exploded perspective view of the first optical axis unit of the lens barrel, and FIG. 4 is an exploded perspective view of the second optical axis unit of the lens barrel. .

  FIG. 5 is an assembled perspective view of the second group unit of the lens barrel, and FIG. 6 is an exploded perspective view of the second group unit. 7 is an assembled perspective view of the third group unit of the lens barrel, FIG. 8 is an exploded perspective view of the third group unit, FIG. 9A is a cross-sectional view of the third group unit in the photographing state, and FIG. ) Is a cross-sectional view when the third group unit is in a photographing state, and FIG. 10 is a rear view when the second optical axis unit is in a photographing state.

  FIG. 11 is an operation explanatory view when the first optical axis unit is in the retracted state, FIG. 12 is an operation explanatory view when the second group unit is in the retracted state, and FIG. 13 is a perspective view of the fixed base plate of the lens barrel. FIG. 14 is a diagram for explaining the operation of the third group unit in the retracted state, and FIG. 15 is a perspective view of a straight barrel of the lens barrel.

  16A is a side view of the third group unit, FIG. 16B is a side view of the third group unit of the lens barrel according to the reference example of the present invention, and FIG. 17A is a side view of the third group unit. FIG. 17B is a side view of the third group unit of the lens barrel according to the reference example of the present invention. FIG. 18 is a front view of the second optical axis unit.

  FIG. 19A is a cross-sectional view of a positioning portion of a third group base plate as a support member of the third group unit, and FIG. 19B is a partially enlarged view of FIG. FIG. 20A is a cross-sectional view of the steady portion of the third group base plate of the third group unit, and FIG. 20B is a partially enlarged view of FIG. FIG. 21 is a sectional view of the first optical axis unit in the retracted state, and FIG. 22 is a sectional view of the first optical axis unit in the photographing state.

  FIG. 23 (a) is an explanatory diagram of the entrance of a light beam in a lens barrel according to a reference example of the present invention, and FIG. 23 (b) is a partially enlarged view of FIG. 23 (a). FIG. 24 (a) is an explanatory view of the entrance of a light beam in a lens barrel according to a reference example of the present invention, and FIG. 24 (b) is a partially enlarged view of FIG. 24 (a).

  First, the configuration of the lens barrel in the embodiment of the present invention will be described with reference to FIGS.

  In the embodiment of the present invention, the lens barrel includes, in order from the object side, the first lens unit L1, the second lens unit L2, the third lens unit L3b, the fourth lens unit L4a, L4b, L4c, and the fifth lens unit. This is a six-group photographic optical system composed of a lens group L5 and a sixth lens group L6. L3a is a prism that guides the first optical axis A to the second optical axis B orthogonal to the first optical axis A (which forms an angle of 90 °).

  Reference numeral 11 denotes a first group holding frame that holds the first lens group L 1, and is held by the first group cylinder 12. A set of three cam pins 12 a arranged below the outer peripheral surface of the first group cylinder 12 is engaged with a cam groove 8 a formed on the inner peripheral surface of the cam cylinder 8. Further, another set of three cam pins 12b is inserted into the cam groove 8b formed on the inner peripheral surface of the cam cylinder 8 with a slight clearance. Further, the first group cylinder 12 is formed with straight movement keys (not shown) at three locations on the inner circumferential surface, and is engaged with a straight movement groove 7 a formed on the outer circumferential surface of the straight movement cylinder 7.

  Reference numeral 21 denotes a second group holding frame that holds the second lens group L2, and is held by the second group base plate 22. Three cam pins 22 a arranged on the outer periphery of the second group base plate 22 are engaged with cam grooves 8 c formed on the inner peripheral surface of the cam cylinder 8. Further, the second group base plate 22 is formed with a rectilinear key 22b at the same position as the cam pin 22a (see FIG. 5), and is engaged with a rectilinear groove 7b formed in the rectilinear cylinder 7 (see FIG. 15).

  A groove 8 d formed below the inner peripheral surface of the cam cylinder 8 is engaged with a plurality of protrusions 7 c formed below the outer peripheral surface of the rectilinear cylinder 7. The cam cylinder 8 is rotatably supported by the rectilinear cylinder 7 and moves in the first optical axis direction integrally with the rectilinear cylinder 7. Further, the three cam pins 8 e arranged below the outer peripheral surface of the cam cylinder 8 are engaged with cam grooves 9 a formed on the inner peripheral surface of the fixed cylinder 9.

  The rectilinear cylinder 7 regulates the first group cylinder 12 and the second group base plate 22 in a straight line. The four rectilinear keys 7 d formed at the lower end of the outer peripheral surface of the rectilinear cylinder 7 are engaged with rectilinear grooves 9 b formed on the inner peripheral surface of the fixed cylinder 9.

  A gear portion (not shown) formed below the outer peripheral surface of the cam cylinder 8 is connected to a cam cylinder driving device constituted by a DC motor 15 and a plurality of gear parts 16.

  When the cam cylinder 8 is rotated by the output of the cam cylinder driving device, the cam cylinder 8 moves in the optical axis direction while rotating by the action of the cam pin 8e of the cam cylinder 8 and the cam groove 9a of the fixed cylinder 9.

  The first group cylinder 12 is rotated by the action of the cam pin 12a of the first group cylinder 12 and the cam groove 8a of the cam cylinder 8, and the action of the straight key (not shown) of the first group cylinder 12 and the straight groove 7a of the straight cylinder 7. Without moving in the direction of the optical axis.

  The second group base plate 22 does not rotate by the action of the cam pin 22a of the second group base plate 22 and the cam groove 8c of the cam cylinder 8 and the action of the straight key 22b of the second group base board 22 and the straight groove 7b of the straight cylinder 7. Move in the direction of the optical axis.

  A third group holding frame 31 holds the prism L3a and the third lens group L3b, and is supported by the third group base plate 32. The positioning part 32a and the steadying part 32b formed on the third group base plate 32 are engaged with the guide bars 13a and 13b arranged on the fixed base plate 10 and supported so as to be movable in the second optical axis B direction. Yes.

  The prism L3a bends the light beam incident from the first optical axis direction in the second optical axis direction extending in the direction orthogonal to the first optical axis.

  Reference numeral 42 denotes a fourth group base plate that holds the fourth lens group L4b. The positioning portion 42a and the steadying portion 42b formed on the fourth group base plate 42 are engaged with guide bars 13a and 13b arranged on the fixed base plate 10. Thus, it is supported so as to be movable in the second optical axis B direction. A rack (not shown) is disposed on the fourth group base plate 42 and is screwed into a screw of the stepping motor 45.

  When the rack (not shown) is driven by the output of the stepping motor 45, the fourth group base plate 42 is not rotated by the action of the positioning part 42a, the steadying part 42b, and the guide bars 13a and 13b. Move in direction B.

  Reference numeral 41 denotes an aperture / shutter which is fixed to the fourth group base plate 42 by screws (not shown).

  Reference numeral 43 denotes a fourth group holding frame that holds the fourth lens group L4c, and is held by the fourth group base plate.

  Reference numeral 5 denotes a fifth group holding frame for holding the fifth lens group L5. The positioning portion 5a and the steadying portion 5b formed on the fifth group holding frame 5 are arranged on guide bars 13a and 13b arranged on the fixed base plate 10. It is engaged and supported so as to be movable in the second optical axis B direction.

  The fifth group holding frame 5 is urged toward the subject side in the second optical axis B direction by the fifth group spring 51, and the contact portion 5 c of the fifth group holding frame 5 is fixed to the fixed base plate 10 in the photographing state. It is in contact with the contact portion 10a (see FIG. 10).

  Reference numeral 6 denotes a sixth group holding frame for holding the sixth lens group L6. The positioning portion 6a and the steadying portion 6b formed on the sixth group holding frame 6 are arranged on guide bars 13a and 13b disposed on the fixed base plate 10. It is engaged and supported so as to be movable in the second optical axis B direction.

  A rack 61 is disposed on the sixth group holding frame 6 and is screwed into a screw of the stepping motor 62. When the rack 61 is driven by the output of the stepping motor 62, the sixth group holding frame 6 is rotated in the second optical axis direction without rotating by the action of the positioning portion 6a, the steadying portion 6b, and the guide bars 13a and 13b. Move to.

  The image sensor S and the optical filter F are held on the fixed ground plane 10. The fixed cylinder 9 and the cover 14 are fixed to the fixed base plate 10 with screws.

  In the lens barrel of the present invention, the first group cylinder 12 and the second group base plate 22 are moved in the first optical axis A direction, and the diaphragm / shutter 41 and the fourth group base plate 42 are moved forward and backward in the second optical axis B direction to zoom. Operation is performed. Further, the sixth group holding frame 6 moves back and forth in the second optical axis B direction to perform the focusing operation. The third group holding frame 31 and the fifth group holding frame 5 are stopped at predetermined positions during both operations.

  Next, the configuration of the second group unit will be described with reference to FIGS.

  In the second group holding frame 21, a guide bar 24 is press-fitted into a positioning portion 21 a formed in the second group holding frame 21 as a first holding member, and rotates together with the guide bar 24. The guide bar 24 is fitted to the positioning portions 22c and 22d of the second group base plate 22 as a second holding member, and is rotatably supported by the second group base plate 22.

  Further, the second group holding frame 21 has a hook engaging portion (not shown) on which one end of a spring 23 for applying a torsional force is hung. The spring 23 is disposed on the outer periphery of the positioning portion 21 a of the second group holding frame 21, and the other end of the spring 23 is hooked on the locking portion 22 f of the second group base plate 22. The second group holding frame 21 is urged clockwise around the guide bar 24 as viewed from the subject side in the first optical axis A direction, and is formed on the second group holding frame 21 with respect to the second group base plate 22. The rotation stopper 21 b is in contact with a rotation stopper 22 e formed on the second group base plate 22.

  At this time, the center of the second lens unit L2 is a position (photographing position) that coincides with the first optical axis A. The second group holding frame 21 as the first holding member is also subjected to the action of the compressive force of the spring 23, and the positioning portion 21a of the second group holding frame 21 is 2 with respect to the second group base plate 22 as the second holding member. It is in the state contact | abutted to the positioning part 22c of the group ground plate 22. FIG. That is, the second group holding frame 21 is also positioned in the extending direction of the guide bar 24 (the first optical axis A direction).

  The second group base plate 22 as the second holding member moves in the first optical axis direction while holding the first holding member 21 holding the second lens group 2L using the cylindrical body 7 as a guide member.

  Next, the configuration of the third group unit will be described with reference to FIGS.

  In the third group holding frame 31, a guide bar 34 is press-fitted into a positioning portion 31 a formed in the third group holding frame 31, and rotates together with the guide bar 34. Further, the guide bar 34 is fitted to the positioning portions 32 c and 32 d of the third group base plate 32 and is rotatably supported by the third group base plate 32. In addition, the guide bar 34 is preferably disposed in the vicinity of the apex angle of the prism L3a on the image plane side in the first optical axis A direction because of its space efficiency.

  Further, the third group holding frame 31 has a hook engaging portion 31c on which one end of a spring 33 for applying a torsional force is hung. The spring 33 is disposed on the outer periphery of the guide bar 34, and the other end of the spring 33 is hung on the engaging portion 32 f of the third group base plate 32. The third group holding frame 31 is urged counterclockwise on the guide bar 34 in FIG. 9B, and a rotation stopping portion 31b formed on the third group holding frame 31 with respect to the third group base plate 32 is provided. The rotation stop portion 32e formed on the third group base plate 32 is in contact with the rotation stop portion 32e.

  At this time, the reflecting surface of the prism L3a is at a position (shooting position) that forms approximately 45 degrees with the first optical axis A and the second optical axis B. Further, the third group holding frame 31 is also subjected to the action of the compressive force of the spring 33, and the positioning portion 31 a of the third group holding frame 31 is in contact with the positioning portion 32 c of the third group base plate 32 with respect to the third group base plate 32. It has become. That is, the third group holding frame 31 is also positioned in the extending direction of the guide bar 34 (direction perpendicular to the first optical axis A and the second optical axis B).

  Reference numeral 35 denotes a third group cover that covers the reflecting surface of the prism L3a, and the two locking portions 35a formed on the third group cover 35 are locked to the locking portions 31d formed on the third group holding frame 31. Further, since the third group cover 35 approaches the third group base plate 32 in the retracted state, the third group cover 35 is formed of a thin resin, and is devised so that the resin thickness and rigidity of the third group base plate 32 can be secured. The third group cover 35 may be formed of a sheet metal member.

  The third group base plate 32 has a hook locking portion 32g, on which one end of a spring 36 for applying a tensile force is hung. The other end of the spring 36 is hooked on the hook engaging portion 10 b of the fixed ground plate 10, and the third group ground plate 32 is formed on the fixed ground plate 10 with a main positioning portion 32 h formed on the third ground plate 32 with respect to the fixed ground plate 10. The main positioning portion 10c is in contact (see FIG. 18). The sub-positioning portion 32 i formed on the third group base plate 32 is opposed to the sub-positioning portion 10 d formed on the fixed base plate 10 with a slight gap, and the third group base plate 32 is unlikely to fall over the fixed base plate 10. It is in a state. In this way, the third group base plate 32 is positioned in the extending direction of the guide bars 13a and 13b (second optical axis B direction).

  At this time, the spring 36 is hung at a predetermined angle with respect to the moving direction of the third group base plate 32. Since the third group base plate 32 is housed inside the cam cylinder 8 in the retracted state, the positioning portion 32a of the third group base plate 32 cannot have a long fitting length with respect to the guide bar 13a. For this reason, the variation in falling of the third group base plate 32 due to the backlash between the positioning portion 32a and the guide bar 13a increases. Therefore, the third group base plate 32 is also urged in the direction perpendicular to the moving direction of the third group base plate 32 to reduce the tilt variation of the third group base plate 32.

  Further, the closer the hook 36 is to the positioning portion 32 a of the third group base plate 32, the more difficult the third group base plate 32 hits the guide bar 13 a, so the hook locking portion 32 g of the third group base plate 32 is the hook engagement of the fixed base plate 10. It arrange | positions at the guide bar 34 side with respect to the stop part 10b.

  Next, with reference to FIGS. 1 and 4 and FIGS. 11 to 15, the operation of the lens barrel of the present invention in the retracted state will be described. FIG. 11 and FIG. 12 or FIG. 14 show the time during operation in FIG. 11 (a), FIG. 12 (a) or FIG. 14 (a), FIG. 11 (b), FIG. 11 (c) and FIG. 12 (b), FIG. 11 (d) and FIG. 14 (c), FIG. 11 (e) correspond to FIG. 12 (c) or FIG. 14 (d).

  In FIG. 1B, the stepping motor 62 is first driven to move the sixth group holding frame 6 toward the image plane. Next, the stepping motor 45 is driven, and the fourth group base plate 42 moves to the outside of the fixed cylinder 9 while pressing the fifth group holding frame 5 against the bias of the spring 51 during the movement.

  Then, after the diaphragm / shutter 41 fixed to the fourth group base plate 42 moves to the outside of the fixed cylinder 9, the cam cylinder 8 is rotated by the output of the cam cylinder driving device, and the first group cylinder 12, the second group base plate 22, and the straight advance cylinder. 7. The cam cylinder 8 is retracted. At this time, as shown in FIG. 11, the third group unit moves to the space generated by the movement of the second group unit, and is stored inside the cam cylinder 8. Hereinafter, the operation in the retracted state of the second group unit and the third group unit will be described in detail.

  In FIG. 14B, when the rectilinear cylinder 7 and the cam cylinder 8 are retracted, first, the protrusion 31e formed on the third group holding frame 31 comes into contact with the cam part 7e formed on the rectilinear cylinder 7, The third group holding frame 31 is driven to rotate about the guide bar 34. Since the protrusion 31e of the third group holding frame 31 is far from the guide bar 34, it is desirable that the protrusion 31e be formed around the apex angle (L3aE) of the prism L3a on the subject side in the first optical axis A direction (FIG. 9 ( a)).

  At this time, since the third group base plate 32 supporting the third group holding frame 31 is urged by the spring 36 in the second optical axis B direction (subject side), the protrusion 31e of the third group holding frame 31 moves straight. It also abuts on the abutment portion 7f adjacent to the cam portion 7e of the cylinder 7. When the protrusion 31e is rotated while being in contact with the contact part 7f, the distance between the positioning part 31a of the third group holding frame 31 and the protrusion 31e and the rotation angle of the third group holding frame 31 are 3 The group unit resists the pulling force of the spring 36 and also moves in translation in the direction of the optical axis B (image plane side).

The translational distance X in the translational direction of the third group unit is the distance L of the straight line 31A connecting the positioning portion 31a and the projection 31e of the third group holding frame 31, and the angle θ formed by the straight line 31A and the second optical axis B. From this, X = L × (COSθ ₂ −COSθ ₁ ). Θ _{1 and} θ ₂ are the angles θ before and after the rotation of the third group holding frame 31.

  In this embodiment, when shifting from the photographing state to the retracted state, the straight cylinder 7 as a cylinder has a cam portion 7e as a first contact portion and a contact portion 7f as a second contact portion. The holding member 31 is rotated and translated in contact with the protrusion 31e of the holding member.

  Thereafter, the tapered portion 7g as the third abutting portion abuts on the tapered portion 32j as the abutting portion of the ground plate member 32 as the supporting member, and translates the ground plate member 32 as the supporting member.

  In the rectilinear cylinder 7, after the tapered portion 7g as the third abutting portion comes into contact with the tapered portion 32j of the base plate member 32, only the cam portion 7e comes into contact with the protruding portion 31e of the holding member 31, and the protruding portion 31e. With the rotation restriction of the cam portion 7e, the holding member 31 does not rotate and the holding member 21 only performs translation.

  However, as a modification, even after the tapered portion 7g as the third contact portion contacts the tapered portion 32j as the contact portion of the base plate member 32 as the support member, the protrusion 31e of the holding member is the cam portion. The holding member 31 may continue to rotate by coming into contact with 7e and the contact portion 7f.

  At this time, the rotation stopping portion 31b, the hook locking portion 31c, and the protrusion 31e of the third group holding frame 31 are arranged on the same side of the side surface of the prism L3a. In FIG. 16A, the third group holding frame 31 receives a component force F1 parallel to the first optical axis A direction by the spring 33, and in the S1 direction centering on the hook locking portion 31c on which one end of the spring 33 is hooked. Fall down. As shown in FIG. 16 (b), the rotation stopping portion 31b of the third group holding frame 31 (the rotation stopping portion 32e of the third group base plate 32) and the hook locking portion 31c are arranged on opposite sides of the side surface of the prism L3a. The distance L between the rotation stop portion 31b and the hook locking portion 31c becomes longer.

  Therefore, the third group holding frame 31 is greatly affected by the fall due to the backlash between the positioning portions 32 c and 32 d of the third group base plate 32 and the guide bar 34. The same applies when the third group holding frame 31 receives a component force parallel to the second optical axis B direction by the spring 33.

  In FIG. 17A, the third group holding frame 31 receives a component force F1 parallel to the first optical axis A direction at the hook engaging portion 31c by the spring 33, and the projecting portion 31e is 1 receives a thrust F2 parallel to the optical axis A direction. As shown in FIG. 17B, when the hook engaging portion 31c and the protruding portion 31e of the third group holding frame 31 are arranged on opposite sides of the side surface of the prism L3a, the hook engaging portion 31c and the protruding portion are provided. The distance L to 31e becomes longer.

  For this reason, the moment M applied to the third group holding frame 31 is increased, and the third group holding frame 31 is easy to turn against the third group base plate 32. Therefore, the rotation stopping portion 31b, the hook locking portion 31c, and the protruding portion 31e of the third group holding frame 31 are arranged on the same side of the side surface of the prism L3a so that the third group holding frame 31 falls or the third group base plate 32 is disposed. Suppresses the resentment against

  Further, with the above configuration, the actuator 41a of the diaphragm / shutter 41 is made to enter the opposite side of the side surface of the prism L3a, thereby realizing space saving of the lens barrel (see FIG. 18). Further, the positioning portion 32 a of the third group base plate 32 is disposed near the protruding portion 31 e of the third group holding frame 31. Since the positioning portion 32a of the third group base plate 32 is fitted to the guide bar 13a in a wide range, the cam portion 7e of the rectilinear cylinder 7 comes into contact with the protruding portion 31e of the third group holding frame 31 in the optical axis A direction. Even when a load is applied, it is difficult for stress to concentrate on the guide bar 13a.

  In FIG. 12B, when the third group holding frame 31 is rotated, the cam portion 21e formed on the protruding portion 21d of the second group holding frame 21 is then the cam portion formed on the protruding portion 10e of the fixed base plate 10. 10f abuts. When the cam portion 21e is brought into contact with the cam portion 10f, a component force perpendicular to the direction of the optical axis A is generated according to the shape of each cam portion, and the second group holding frame 21 resists the torsional force of the spring 23 to Is driven to rotate counterclockwise around the center.

  When the second group holding frame 21 is fully rotated, the contact portion 21f adjacent to the cam portion 21e and parallel to the first optical axis A direction is adjacent to the cam portion 10f and parallel to the first optical axis direction. The second group holding frame 21 is restricted by the fixed base plate 10 in contact with the contact portion 10g. Thus, the load in the first optical axis A direction is not applied to the second group holding frame 21 after the rotation. For this reason, in the retracted state, no load is applied to the cam cylinder 8 engaged with the second group base plate 22 and the second group base plate 22 that support the second group holding frame 21, and the retractable load of the lens barrel is reduced.

  In FIG. 14 (c), when the second group holding frame 21 is fully rotated, the tapered portion 32 j formed on the third group base plate 32 contacts the tapered portion 7 g formed on the rectilinear cylinder 7. When the taper portion 32j is brought into contact with the taper portion 7g, a component force perpendicular to the first optical axis A direction is generated, and the third group base plate 32 resists the pulling force of the spring 36 in the second optical axis direction ( Translated to the image plane side). Thereafter, the protrusion 31e of the third group holding frame 31 is separated from the contact portion 7f of the rectilinear cylinder 7 and contacts only the cam portion 7e. Therefore, the third group holding frame 31 is only rotationally driven by the cam portion 7e (see FIG. 14D).

  Even if there is no taper portion 32j of the third group base plate 32 and taper portion 7g of the straight advance cylinder, the third group unit is formed by the projection 31e of the third group holding frame 31, the cam portion 7e of the straight advance cylinder 7, and the contact portion 7f. Can translate. However, in that case, in order to obtain a longer moving distance in the translational direction of the third group unit, it is necessary to increase the distance L of the straight line 31A connecting the positioning portion 31a and the protruding portion 31e of the third group holding frame 31. Therefore, the third group holding frame 31 becomes large, and it is difficult to reduce the size of the lens barrel. Therefore, the taper portion 32j of the third group base plate 32 and the taper portion 7g of the rectilinear cylinder 7 compensate for the movement distance in the translation direction, thereby realizing a reduction in the size of the lens barrel.

  In FIG. 19, the abutting portion 32 l formed on the third group base plate 32 faces the abutting portion 10 h formed on the fixed base plate 10 with a slight gap in the first optical axis A direction. Therefore, even if the tapered portion 7g of the straight cylinder 7 is brought into contact with the tapered portion 32j of the third group base plate 32 and a load is applied in the first optical axis A direction, the guide bar 13a in the vicinity of the tapered portion 32j does not receive the first light. The third group base plate 32 can be translated without moving over the guide bar 13a without being displaced in the direction of the axis A by a predetermined amount or more.

  In FIG. 14 (d), when the third group base plate 32 has completely translated, the abutting portion 32k of the third group base plate 32 adjacent to the tapered portion 32j and parallel to the first optical axis A direction, An abutting portion 7h parallel to the first optical axis A direction is abutted adjacent to the tapered portion 7g, and the third group base plate 32 is translationally restricted by the rectilinear cylinder 7. Thus, the third group base plate 32 is not subjected to a load in the first optical axis A direction after translation. Therefore, at the time of starting, the thrust in the first optical axis A direction applied to the rectilinear cylinder 7 is reduced, and the lens barrel is unlikely to start suddenly.

  When the third group base plate 32 is in the retracted state, the position of the contact portion 32k on the positioning portion 32a side is restricted by the contact portion 7h of the rectilinear cylinder 7, but the position of the steady stop portion 32b side is not restricted. Therefore, when the lens barrel receives an impact such as dropping, the steadying portion 32b of the third group base plate 32 vibrates around the contact portion 32k as shown in FIG. 20, and the contact portion 32k is caused by the vibration load. There is a possibility that the abutting portion 7h of the straight cylinder 7 that abuts on the surface may be damaged. Therefore, the position of the steady stop portion 32b is regulated in the second optical axis B direction by the steady stop portions 12d and 12e formed in the first group cylinder 12 to reduce the vibration of the steady stop portion 32b.

  The prism L3a as the bending optical element is restricted in movement by the holding member 12 that holds the first lens unit L1.

  Thus, the lens barrel retracting operation is completed. In the photographing state, the first group cylinder 12, the second group base plate 22, the rectilinear cylinder 7 as a cylinder, and the cam cylinder 8 are unwound first. Then, after the first group cylinder 12, the second group base plate 22, the rectilinear cylinder 7, and the cam cylinder 8 are extended to the predetermined positions, the fourth group base plate 42 moves to the predetermined position together with the fifth group holding frame 5, and then holds the sixth group. The frame 6 moves to a predetermined position.

  Next, with reference to FIG. 21, the state of the first optical axis unit of the present invention in the retracted state will be described.

  In FIG. 21, the prism L3a as the bending optical element rotates approximately 45 degrees with the guide bar 34, which is the third axis orthogonal to the first optical axis and the second optical axis, as the rotation axis with respect to the photographing state. Thus, the second lens unit L2 is arranged in parallel in the direction of the optical axis B. In addition, the prism L3a is moved toward the image plane due to the relationship between the positioning portion 31a of the third group holding frame 31 and the projection 31e, so that the image is formed on the second lens group L2 in the second optical axis B direction. It is arranged on the surface side. The apex angle L3aE of the prism L3a enters the small diameter portion L2D of the second lens group L2, and the prism L3a and the second lens group L2 overlap each other when viewed from the direction of the first optical axis A. (OL).

  With the above configuration, the diameter of the lens barrel is reduced by arranging the prism L3a and the second lens group L2 close to each other in the second optical axis B direction.

  The second lens unit L2 moves in the second optical axis direction when shifting from the shooting state to the retracted state, and the prism L3a moves in the second optical axis direction when shifting from the shooting state to the retracted state. By moving in a direction different from that of the first lens group, the second lens group 2L and the prism L3a are accommodated in the cylinder that is the rectilinear cylinder 7 in the retracted state.

  When the prism L3a as the bending optical element shifts from the photographing state to the retracted state, the prism L3a rotates by using the third axis (guide bar 34) orthogonal to the first optical axis and the second optical axis as the rotation axis. It moves in the direction opposite to the second lens group 2L in the second optical axis direction.

  In the second group base plate 22, an annular portion 22g is formed in the space between the exit surface of the prism L3a and the rectilinear cylinder 7. The second group base plate 22 is not enlarged in the outer diameter direction. The member rigidity is ensured.

  The second group holding frame 21 is formed with a light shielding portion 21h, and is located in a space between the second lens group L2 and the incident surface of the prism L3a. In FIG. 22, the light shielding part 21 h shields the gap C <b> 2 between the cylindrical part 21 g of the second group holding frame 21 and the second group base plate 22 in the photographing state. The gap C <b> 2 is a gap that is generated when the third lens unit L <b> 3 b and the third group holding frame 31 penetrate the second group base plate 22 in the direction of the optical axis A in the retracted state. If the light-shielding portion 21h is not formed on the second group holding frame 21, the light beam G1 passes through the gap C2 and reaches the imaging plane as shown in FIG. As a result, the image quality is adversely affected, such as ghosting.

  Therefore, the light shielding portion 21h is formed in the second group holding frame 21 to prevent the unnecessary light flux passing through the gap C2 from reaching the imaging surface. In addition, the light shielding part 21h formed on the second group holding frame 21 and the light shielding part 22h formed on the second group base plate 22 overlap each other when viewed from the first optical axis A direction (O2). The first optical axis A direction and the second optical axis B direction are opposed to each other with a slight gap.

  With the above configuration, the light beam G1 that has passed through the gap C2 does not easily pass between the light shielding part 21h and the light shielding part 22h. Further, the light shielding part 21h is positioned on the image plane side with respect to the light shielding part 22h in the first optical axis A direction, and the light shielding measure is realized without increasing the size of the second group unit in the first optical axis A direction. doing.

  A chamfered portion 31f is formed in the third group holding frame 31, and the first lens unit L1 enters the space generated by the stepped chamfered portion 31f when in the retracted state. The chamfered portion 31f is formed with a light shielding bundle that is parallel or perpendicular to the first optical axis A direction (see FIG. 7). If the light shielding bundle is not formed on the chamfered portion 31f, the chamfered portion 31f has a predetermined angle with respect to the entrance surface and the exit surface of the prism L3a, and thus the light beam G2 as shown in FIG. 24 is reflected on the chamfered portion 31f. To reach the image plane.

  In the retracted state, the lenses constituting the second lens group 2L disposed on the object side with respect to the second lens group 2L are stepped formed on a holding member that holds the prism L3a in the first optical axis direction. It is located in the chamfer.

  As a result, the image quality is adversely affected, such as ghosting. Therefore, a light shielding bundle parallel to or perpendicular to the incident surface and the exit surface of the prism L3a is formed on the chamfered portion 31f of the third group holding frame 31 to prevent unnecessary light fluxes from reaching the imaging surface. With the above configuration, a light shielding measure is realized while reducing the size of the lens barrel.

  As mentioned above, although the preferable Example of this invention was described, this invention is not limited to these Examples, A various deformation | transformation and change are possible within the range of the summary.

  For example, in the embodiment of the present invention, the configuration in which the third group unit is driven by the rectilinear cylinder 7 is illustrated. However, the present invention is not limited to this, and the present invention is also applied to a configuration in which the third group unit is driven by another cylindrical body. it can.

  Moreover, although the structure which position-controls the steadying part 32b of the 3rd group baseplate 32 in the optical axis B direction by the steadying parts 12d and 12e formed in the 1st group cylinder 12 was illustrated, it is not limited to this, 3 The present invention can also be applied to a configuration in which the position of the steadying portion 32b of the group base plate 32 is regulated by another cylindrical body.

  Further, the configuration in which the prism L3a is rotated by approximately 45 degrees in the retracted state is illustrated, but the present invention is not limited to this, and the present invention is not limited to this as long as the prism L3a is rotated with respect to the shooting state. Can be applied.

  In addition, the actuator 41a of the diaphragm / shutter 41 is inserted into the side of the prism L3a opposite to the side where the rotation stopper 31b, the hook stopper 31c, and the protrusion 31e of the third group holding frame 31 are disposed. However, the present invention is not limited to this, and a part of another member is allowed to enter the opposite side of the third group holding frame 31 on which the rotation stopping portion 31b, the hook locking portion 31c, and the protruding portion 31e are arranged. The present invention can also be applied to a configuration having the above configuration. Further, the present invention can also be applied to a configuration in which a part of another member is made to enter the same surface side where the rotation stopping portion 31b, the hook locking portion 31c, and the protruding portion 31e of the third group holding frame 31 are arranged.

  Further, the configuration in which the apex angle L3aE of the prism L3a has entered the small diameter portion L2D of the second lens unit L2 is illustrated, but the configuration is not limited thereto, and the apex angle L3aE of the prism L3a is configured by a plurality of lenses. The present invention can also be applied to a configuration that enters a small-diameter lens of the second lens unit L2.

  Moreover, although the structure in which the annular portion 22g of the second group base plate 22 is formed in the space between the exit surface of the prism L3a and the rectilinear cylinder 7 is illustrated, the present invention is not limited thereto, and the prism L3a and the rectilinear cylinder 7 The present invention can also be applied to a configuration in which a part of another member is formed in the space between.

  Further, the configuration in which the third lens group L3b and the third group holding frame 31 penetrate through the second group base plate 22 in the retracted state is illustrated, but the present invention is not limited to this, and other members include the second group base plate 22. However, the present invention can also be applied to a configuration penetrating through.

  In addition, the configuration in which the light shielding portion 21h of the second group holding frame 21 is located in the space between the second lens group L2 and the incident surface of the prism L3a is illustrated, but the present invention is not limited to this. The present invention can also be applied to a configuration in which a part of another member is located in a space between the lens group L2 and the incident surface of the prism L3a.

  In addition, the configuration in which the first lens unit L1 enters the space generated by the chamfered portion 31f when in the retracted state is illustrated, but the present invention is not limited to this, and the chamfered portion when the other member is in the retracted state. The present invention can also be applied to a configuration entering the space generated by 31f.

A 1st optical axis B 2nd optical axis G1 Unnecessary light beam G2 Unnecessary light beam L1 1st lens group L2 2nd lens group L2D 2nd lens group small diameter part L3a Prism L3aE Apex angle OL of 2nd lens Group and prism overlap range 7 Linear cylinder 7e Cam part 7g Tapered part 12 Group 1 cylinder 21 Group 2 holding frame 21h Light blocking part 22 Group 2 base plate 22g Ring part 31 Group 3 holding frame 31f Chamfered part

Claims (9)

A first lens group disposed in the first optical axis direction and a light beam incident from the first optical axis direction are bent in a second optical axis direction extending in a direction different from the first optical axis. A lens barrel comprising: a prism; and a cylindrical body that moves in the first optical axis direction as the first lens group moves.
The first lens group moves in the second optical axis direction when transitioning from the photographing state to the retracted state, and the prism moves the second light when transitioning from the photographing state to the retracted state. The first lens group and the prism are housed in the cylindrical body in the retracted state by moving in a direction different from the first lens group in the axial direction.
A lens barrel, wherein a part of the prism is superimposed on the first lens group when viewed from the first optical axis direction. A first lens group disposed in the first optical axis direction and a light beam incident from the first optical axis direction bent in a second optical axis direction extending in a direction orthogonal to the first optical axis A lens barrel comprising: a prism to be moved; and a cylindrical body that moves in the first optical axis direction as the first lens group moves.
When the first lens group shifts from the photographing state to the retracted state, the first lens group moves in the second optical axis direction by rotating about the first optical axis,
When the prism transitions from the photographing state to the retracted state, the prism rotates with the third optical axis orthogonal to the first optical axis and the second optical axis as the second optical axis. A lens barrel that moves in a direction different from that of the first lens group.   The lens barrel according to claim 1, wherein the first optical axis is orthogonal to the second optical axis.   4. In the retracted state, as viewed from the first optical axis direction, an apex angle of the prism is superimposed on a lens constituting the first lens group. The lens barrel according to one item.   In the retracted state, the lenses constituting the second lens group disposed on the object side with respect to the first lens group are steps formed on a holding member that holds the prism in the first optical axis direction. The lens barrel according to claim 1, wherein the lens barrel is located in a chamfered portion.   A first holding member that moves in the direction of the second optical axis by rotating about the first optical axis while holding the first lens group, and the cylindrical body as a guide member. 6. A second holding member that moves in the direction of the first optical axis while holding a first holding member that holds one lens group. 6. The lens barrel described in 1.   The lens barrel according to claim 6, wherein in the retracted state, the second holding member is disposed between the cylindrical body and the exit surface of the prism.   8. The lens barrel according to claim 6, wherein, in the retracted state, a protrusion of the first holding member is disposed between the incident surface of the prism and the first lens group. 9. .   An imaging apparatus comprising: the lens barrel according to claim 1; and an imaging element.

Images