JP4804554B2 - Lens barrel - Google Patents

Description

  The present invention relates to a structure of a lens barrel having a rotating frame and a rectilinear guide frame that advances and retreats together with the rotating frame.

  A generally retractable lens barrel is housed in a camera body when housed, and protrudes from the camera body when photographing. In recent years, collapsible lens barrels generally have a structure that advances and retreats due to a zooming operation of an optical system during photographing.

  As described above, the structure of the lens barrel that advances and retreats includes a drive frame provided with a helicoid and a cam, and the drive frame and the drive frame are integrally displaced in the optical axis direction. A structure having a rectilinear guide frame having a rectilinear guide that rotates in the optical axis and extends in the optical axis direction is generally used. And while being engaged with the helicoid or cam provided in the said drive frame, the to-be-driven frame engaged with the rectilinear guide provided in the said rectilinear guide frame is made to advance / retreat to an optical axis direction.

  Further, the conventional lens barrel is also required to have a light shielding property so that unnecessary light flux does not enter the lens barrel in order to prevent flare and ghost. For this purpose, for example, it is common to prevent the unnecessary light flux from entering the lens barrel by adopting a configuration in which only one of the drive frame and the rectilinear frame is exposed to the outside of the lens barrel. Structure.

  The structure of the conventional lens barrel described above is proposed in, for example, Patent Documents 1 and 2.

  In recent years, there has been a demand for further miniaturization (thinning) of cameras. Therefore, the lens barrel is also required to have a smaller dimension in the thickness direction when retracted.

  As described above, in the conventional lens barrel, if only one of the drive frame and the rectilinear frame is exposed to the outside of the lens barrel, the light shielding property is excellent, but one frame member is used for the other frame. It is difficult to reduce the size because it is necessary to cover the member.

  An object of the present invention is to provide a lens barrel that has a simple configuration and can be further reduced in thickness in the retracted state in view of the above-described circumstances.

The lens barrel of the present invention includes a fixed frame that supports the imaging unit, a rotary frame that moves around the optical axis with respect to the fixed frame, and advances and retreats in the optical axis direction with respect to the fixed frame, and the rotary frame disposed in the inside, the rotary frame relative rotation about the optical axis with respect to, and a rectilinear guide frame to move forward and backward integrally displaced in the optical axis direction, can move forward and backward in the inside of the rectilinear guide frame Inserted into the front part, a barrier that can be opened and closed at the front part, a first group frame that holds the first lens group at the rear part, and a rear part that is inserted in such a manner that it can move forward and backward behind the first group frame inside the linear guide frame. The second group frame holding the second group lens, and in front of the second group frame inward of the rectilinear guide frame, forward in the optical axis direction by the first biasing spring with respect to the second group frame In a state of being urged to be movable relative to the second group frame. The forward and backward movement in the direction of the optical axis is performed between the shutter frame configured by covering the shutter blades with the shutter lid and the front of the linear guide frame and the first group frame in front of the shutter frame. A flare stop having an opening formed in the center, which is disposed so as to be in contact with the rear surface of the first group frame, and disposed between the shutter frame and the flare stop, and a part of the flare stop is disposed on the shutter frame. A flare stop biasing spring fixed to the other portion of the flare stop and biasing the flare stop toward the front in the optical axis direction.
When the first group frame is moved forward relative to the second group frame and the rear surface of the first group frame is disposed at a position where it does not contact the flare stop, the flare stop is It is biased toward the front in the optical axis direction by the flare stop biasing spring and is held in a state orthogonal to the optical axis at a position spaced apart from the shutter frame by a predetermined distance,
When the first group frame is moved rearward relative to the second group frame and reaches a settling state or a tele state, the flare stop resists the biasing force of the flare throttle biasing spring. The rear surface of the first group frame is pressed relatively rearward and is in close contact with the shutter frame with the flare stop biasing spring sandwiched therebetween.

  According to the present invention, it is possible to provide a lens barrel that has a simple configuration and can be further thinned in a retracted state.

It is a disassembled perspective view of the lens barrel of one Embodiment of this invention. FIG. 2 is an exploded perspective view of a shutter / second group unit of the lens barrel in FIG. 1. FIG. 3 is a perspective view of the shutter / second group unit of FIG. 2. FIG. 4 is an exploded perspective view of a third group / fourth group / imaging unit of the lens barrel in FIG. 1. It is a longitudinal cross-sectional view in the retracted state of the lens barrel of FIG. It is a longitudinal cross-sectional view in the wide state of the lens barrel of FIG. It is a longitudinal cross-sectional view in the tele state of the lens barrel of FIG. FIG. 2 is a development view of an outer peripheral portion of a rotating frame and a rectilinear guide frame in the lens barrel of FIG.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is an exploded perspective view of a lens barrel according to an embodiment of the present invention. FIG. 2 is an exploded perspective view of the shutter / second group unit of the lens barrel. FIG. 3 is a perspective view of the shutter / second group unit. FIG. 4 is an exploded perspective view of the third group / fourth group / imaging unit. 5, 6 and 7 are longitudinal sectional views of the lens barrel in the retracted state, wide state and tele state, respectively. FIG. 8 is a development view of the outer peripheral portion of the rotating frame of the lens barrel and the rectilinear guide frame.

  In the following description, the optical axis of the photographing lens of the present lens barrel is the optical axis O, the subject side in the direction along the optical axis O is the front, and the imaging side (imaging device side) is the rear. The rotation direction is indicated by the rotation direction viewed from the subject side.

  As shown in FIG. 1, the lens barrel 1 of the present embodiment includes a fixed frame 2 fixed to the camera body side, and a rotary frame 3 that is fitted to the inner periphery of the fixed frame 2 and supported so as to be able to rotate forward and backward. The rectilinear guide frame 4 that fits on the inner periphery of the rotary frame 3 and moves forward and backward together, the first group frame 5 that is inserted inward of the rectilinear guide frame 4 and moves forward and backward, and the inward of the rectilinear guide frame 4 The shutter / second group unit 31 that is inserted into and moved back and forth, the third group / fourth group / imaging unit 32 supported inside the rear side of the fixed frame 2, and the outer periphery of the fixed frame 2 are supported. Zoom drive unit 33.

  The fixed frame 2 is a cylindrical member, and is provided with a linearly moving groove 2b along the optical axis O direction, a cam groove 2a, and a gear chamber 2c in which the zoom gear 27 is accommodated in an inner peripheral portion. A zoom drive unit 33 having a zoom motor 25 and a gear box 26 is attached to the outer periphery.

  An output gear (not shown) of a gear train incorporated in the gear box 26 meshes with the zoom gear 27 and transmits the rotation of the zoom motor 25 to the zoom gear 27.

  The rotary frame 3 is a cylindrical frame member, and includes a plurality of first group frame cam grooves 3e, a plurality of second group frame cam grooves 3f on the inner peripheral portion, and a plurality of engagements in front of the inner peripheral portion. A protrusion 3c is provided. A gear portion 3a and a plurality of cam followers 3b having a predetermined circumferential range are provided at the rear end portion of the outer peripheral portion.

  The rectilinear guide frame 4 is a cylindrical frame member, and is provided with a plurality of guide projections 4a projecting outward on the rear end flange portion 4b, and penetrates the inner and outer peripheries along the optical axis O direction. A plurality of first group guide grooves 4e and a plurality of second group guide grooves 4f are provided.

  Furthermore, a plurality of cutouts 4c, which are insertion openings for engaging protrusions, are provided on a circumferential protrusion 4h formed along the circumferential direction on the outer periphery of the rectilinear guide frame 4. The circumferential protrusion 4h is also formed at a position where the first guide groove 4e and the second guide groove 4f are provided in the circumferential direction. And the circumferential guide groove 4d which is a circumferential groove connected to this notch 4c is provided. The circumferential guide groove 4d is formed between the circumferential protrusion 4h and the circumferential step 4i formed by being spaced apart from the circumferential protrusion 4h by a predetermined amount in the optical axis direction.

  The circumferential step portion 4i is formed with a predetermined amount of step from the outer periphery of the rectilinear guide frame 4, and is provided at a position avoiding the first group guide groove 4e and the second group guide groove 4f in the circumferential direction. Yes. The circumferential position of the notch 4c is a different position that does not overlap the first group guide groove 4e and the second group guide groove 4f as shown in FIG. The plurality of guide protrusions 4a engage with the rectilinear grooves 2b in a state where they are assembled to the fixed frame 2. Thereby, rotation of the rectilinear guide frame 4 around the optical axis with respect to the fixed frame 2 is restricted.

  The rectilinear guide frame 4 is inserted into the inner periphery of the rotating frame 3 from the rear side, the engaging protrusion 3c of the rotating frame 3 is inserted from the notch 4c, and is inserted into the circumferential guide groove 4d in a slidable state. Engage (bayonet structure). In this assembled state, the rectilinear guide frame 4 is supported so as not to move relative to the rotation frame 3 in the direction of the optical axis O and to be relatively rotatable, but the rotation is restricted with respect to the fixed frame 3. , Move forward and backward without rotating.

  The front end face parts 4g and 3g, which are the ends in the optical axis direction of the rectilinear guide frame 4 and the rotary frame 3, are on the same plane in the optical axis O direction, and the front end face part 4g of the rectilinear guide frame 4 is rotated. It is not covered by the frame 3 and is exposed.

  As shown in FIGS. 5, 6, and 7, the inner peripheral surface 3 d of the front end surface portion 3 g is formed by a circumferential protrusion 3 h provided on the front end portion of the rotating frame 3 over the entire circumference. The inner peripheral surface 3d is fitted to the outer periphery of the front end surface 4g of the rectilinear guide frame 4 without a gap, and the notch 4c of the rectilinear guide frame 4 has a circumferential protrusion on the rotary frame 3 at the front. It will be in the state covered with 3h. In addition, a circumferential step portion 4 i provided in the rectilinear guide frame 4 is provided behind the notch 4 c (position overlapped in the optical axis direction). Accordingly, it is possible to prevent external light from entering the guide grooves 4e and 4f from the notch 4c and to prevent entry to the imaging side. Furthermore, since the notch 4c and the guide grooves 4e and 4f are arranged at different positions in the circumferential direction, it is possible to prevent leaked external light from reaching the guide grooves 4e and 4f directly from the notch 4c. .

  At the position where the notch 4c is not provided, the circumferential ridge 3h of the rotating frame 3 and the circumferential ridge 4h of the rectilinear guide frame 4 are overlapped with each other, so that external light can effectively enter. Can be prevented.

  When the rotating frame 3 in which the linear guide frame 4 described above is inserted into the inner peripheral portion is inserted into the inner peripheral portion of the fixed frame 2, the gear portion 3 a of the rotating frame 3 meshes with the zoom gear 27. At the same time, the cam follower 3 b is fitted into the cam groove 2 a of the fixed frame 2. Accordingly, the rotation frame 3 is rotationally driven by the rotation of the zoom gear 27, and is extended from the retracted position stored in the fixed frame 2 in the direction of the optical axis O along the cam groove 2a while rotating. The cam groove 2a has a different cam lead angle at a portion corresponding to the position from the retracted position to the imageable position and a portion corresponding to the imageable position during the zooming operation. When the rotary frame 3 further rotates at the photographing enabled position, zooming driving is performed while displacing in the optical axis O direction along the corresponding cam lead during zooming operation. The rectilinear guide frame 4 moves forward and backward integrally with the rotary frame 3 in the optical axis O direction, but its rotation is restricted by the fixed frame 2 and moves in the optical axis O direction.

  The first group frame 5 is a cylindrical frame member, and includes a barrier 41 that can be opened and closed at the front part, a first group lens 42 disposed behind the first group lens 42, and a rectilinear key part 5a that projects from the rear outer peripheral part. Furthermore, a cam follower 48 is fixed to the upper part of the straight key part 5a.

  As shown in FIGS. 1 and 2, the shutter / second group unit 31 includes a shutter frame 7, a second group frame 6, and a flare stop 8, and is assembled as one unit.

  The shutter frame 7 has a guide groove 7d and a guide pin 7e, and a shutter actuator 29 is incorporated therein. Further, a shutter blade 47 that is driven to open and close by the actuator 29 is housed in a state covered with a shutter lid 46. The shutter frame 7 is provided with two contact surfaces 7f on the outer edge.

  A second group lens 43 is held in the second group frame 6, and a rectilinear key portion 6 a, a cam follower 6 b fixed on the key portion, and a claw portion 6 c protruding forward are arranged on the outer side. Furthermore, a guide projection 6d and a guide hole 6e along the optical axis O are arranged.

  In the shutter frame 7, the guide projection 6d and the guide hole 6e of the second group frame 6 are fitted in the guide groove 7d and the guide pin 7e, respectively, and the shutter frame 7 is biased forward by the biasing spring 10 in the optical axis O direction. The second group frame 6 is held so as to be relatively movable.

  When the shutter frame 7 is not pressed on the rear surface of the first group frame 5 (wide and tele states in FIGS. 6 and 7), the shutter frame 7 is separated forward from the second group frame 6 by the urging force of the urging spring 10. The position is determined by the claw portion 6c coming into contact with the contact surface 7f. In the retracted state, the shutter frame 7 is pressed by the rear surface of the first group frame 5 via the flare stop 8 and is in close contact with the second group frame 6 (FIG. 5).

  The flare stop 8 is a thin plate ring-shaped member, has a central opening 8a, and is disposed in front of the shutter frame 7 while being urged forward by the flare stop urging plate spring 9.

  The flare throttling biasing plate spring 9 is formed of an elastically deformable thin metal plate, and is connected to the arcuate mounting portion 9a via the mounting portion 9a and the connecting portion 9c. The annular biasing portion 9b is formed of an inclined surface. And have. Holding holes 9d are provided at both ends of the arcuate mounting portion 9a. The holding hole 9d is engaged with the locking projection 7c of the shutter frame 7, and fixedly supports the mounting portion 9a on the shutter frame 7 (FIG. 3).

  Since one end of the annular urging portion 9b is bonded and fixed to the adhesive portion 8b of the flare stop 8, the front surface of the flare stop 8 is in a released state (free state) where the rear surface of the first group frame 3 is not pressed. At some point, the flare stop 8 is held in a posture orthogonal to the optical axis at a position separated from the shutter frame 7 by a predetermined distance as shown in FIG. When the flare stop 8 is in the separated position, unnecessary light at the time of photographing is prevented from entering the second group lens 43 side. When the front surface of the flare stop 8 is pressed by the rear surface of the first group frame 3 (the retracted state in FIG. 5 and the tele state in FIG. 7), the annular urging portion 9b is elastically deformed to attach the annular shape. The flare stop 8 can be brought into close contact with the shutter lid 46 with the biasing portion 9b interposed therebetween.

  The first group frame 5 and the shutter / second group unit 31 are inserted from the rear side into the rotary frame 3 in which the rectilinear guide frame 4 is fitted on the inner periphery.

  Specifically, the first group frame 5 has the cam follower 48 inserted into the first group guide groove 4e of the rectilinear guide frame 4 and then the slidable key portion 5a is slidably fitted therein. The cam groove 3e is slidably fitted into the straight guide frame 4 and the rotary frame 3.

  Further, the shutter / second group unit 31 inserts the cam follower 6b of the second group frame 6 in the second group guide groove 4f of the straight guide frame 4, and then slidably inserts the straight key part 6a. The cam follower 6 b is slidably fitted into the cam groove 3 f of the rotary frame 3 and is incorporated into the rectilinear guide frame 4 and the rotary frame 3.

  When the rotary frame 3 is rotationally driven in the state where the first group frame 5 and the shutter / second group unit 31 are assembled, the first group frame 5 and the shutter / second group unit 31 are rotated together by the rectilinear guide frame 4. In a restricted state, the rotary frame 3 is moved from the retracted position to a position where it can be photographed as the rotary frame 3 moves, and is displaced along the cam grooves 3e and 3f provided in the rotary frame 3, respectively. Thereafter, at the time of zoom driving, it moves forward and backward to each zoom position.

  As shown in FIGS. 1 and 4, the third group / fourth group / imaging unit 32 includes a third group frame 11 that holds the third group lens 44 and a fourth group frame 12 that holds the fourth group lens 45. And an optical filter 21, a CCD 23 as an image sensor, a CCD fixing plate 24, a holder base plate 13, a focus motor 28, and a photosensor 51, and are assembled as one unit.

  The third group frame 11 has a guide hole 11a into which the guide shaft 15 is slidably fitted, a hole portion 11b through which the feed screw shaft 16 passes, and a guide projection portion 11d.

  The fourth group frame 12 has a U-shaped projecting portion, and a guide shaft that can slide through shaft holes 12a and 12b arranged in the projecting portion and shaft holes 13a and 13b on the holder base plate 13 side. 15 and a rotatable feed screw shaft 16 are supported. A focus motor 28 is incorporated. An output pinion 28a of the focus motor 28 meshes with a gear train 14 for rotationally driving the feed screw shaft 16. Further, two positioning pins 12d for positioning the holder base plate 13 and the CCD fixing plate 24 are disposed from the rear end portion on the image forming plane side of the fourth group frame 12, and the holder base plate 13 and the CCD fixing portion are fixed. Two screw holes (not shown) for fixing the plate 24 are provided. Each screw hole is formed in a boss-like projection.

  The holder base plate 13 is a thin plate-like member having an opening 12a through which the CCD 23 is inserted at the center, and is a metal press part in the present embodiment. Further, a positioning round hole 13d and a positioning long hole 13e through which the positioning pins 12d of the fourth group frame 12 are inserted are formed in the holder base plate. Furthermore, two notches 13h are formed in communication with the opening 13c and through which the screw hole bosses of the fourth group frame 12 are inserted. Further, a positioning round hole 13f and a positioning long hole 13g through which positioning pins provided in the fixed frame 2 are inserted are formed on the outer edge portion of the holder base plate 13, and for fixing to the fixing frame 2 with screws. A plurality of screw insertion holes 13i are formed.

  The CCD fixing plate 24 is a plate to which the CCD 23 is fixed, and is used for fixing to the fourth group frame 12 and the positioning round hole 24a through which the positioning pin 12d of the fourth group frame 12 is inserted and the positioning long hole 24b. A screw insertion hole 24c through which the screw 50 is inserted is provided.

  In such a configuration, the positioning pin 12d of the fourth group frame 12 is inserted into the positioning round hole 13d and positioning long hole 13e of the holder base plate 13, and the positioning round hole 24a and positioning long hole 24b of the CCD fixing plate 24. Thus, the CCD fixing plate 24 and the holder base plate 13 to which the CCD 23 is fixed are positioned with respect to the fourth group frame 12. In this state, the screw boss of the fourth group frame 12 extends to the CCD fixing plate 24 through the notch 13 h of the holder base plate 13. Then, these three members are fixed together by screws 50 in a state where the holder base plate 13 is sandwiched between the CCD fixing plate 24 and the fourth group frame 12.

  A shaft hole 12a of the third group frame 11 is fitted into the guide shaft 15, and an urging spring 18 is inserted. The third group frame 11 is urged forward by the urging spring 18. The third group frame 11 is supported in a state in which the guide projection 11d is slidably fitted into the guide groove 12c of the fourth group frame 12 at a position opposed to the guide shaft 15 and the rotation around the optical axis O is restricted. Has been. On the other hand, a nut 17 is screwed to the feed screw shaft 16. The nut 17 is restricted in rotation by engaging with a guide groove formed in the fourth group frame 12 extending in the optical axis direction. With this configuration, the third group frame 11 is in contact with the urging force of the urging spring 18. When the nut 17 is displaced in the optical axis O direction by rotating the feed screw shaft 16 in this state, the third group frame 11 is also moved integrally in the optical axis O direction.

  The fourth group frame 12 is positioned on the front surface of the holder base plate 13 in a state where the third group frame 12 is assembled, and is fixed by screws. When the feed screw shaft 16 is rotationally driven by the focus motor 28 in the assembled state, the third group frame 11 is driven back and forth (focusing drive) in the direction of the optical axis O via the nut 17. The movement position of the third group frame 11 is detected by detecting the protrusion 11c by the photosensor 51 supported by the fourth group frame 12.

  The holder base plate 13 to which the third group frame 11 and the fourth group frame 12 are attached is fixed to the back surface of the fixed frame 2 with screws.

  The CCD 23 fixed to the CCD fixing plate 24 is incorporated into the fourth group frame 12 through the opening 13c of the holder base plate 13 while being sealed from the periphery by the sealing frame member 22 together with the optical filter 21, and forms an image. Fixed in position.

  Thus, in the present embodiment, the holding unit (fourth group frame 12) that holds the imaging element and the optical member such as the CCD 23, the fourth group lens 45, and the optical filter 21, and the imaging element and the optical member are included. The fixing unit (holder base plate 13) for fixing the third group / fourth group / imaging unit 32, which is the imaging unit, to the fixed frame 2 is constituted by a separate member. Particularly in the present embodiment, since the holder base plate 13 is formed in a thin plate shape, the lens barrel 1 can be thinned.

  The advance / retreat operation of the lens barrel 1 of the present embodiment having the above-described configuration will be described with reference to FIGS.

  When the lens barrel 1 is in the retracted state, the third group frame 11 is retracted so as to be substantially in contact with the fourth group frame 12 by driving the focus motor 28 as shown in FIG. The rotating frame 3 is driven to rotate by the drive of the zoom motor 25 and is retracted together with the rectilinear guide frame 4 to the retracted position with a small gap in the optical axis O direction inside the fixed frame 2. In this state, the front end surfaces 3g and 4g of the rotary frame 3 and the rectilinear guide frame 4 form the same surface, and both are exposed to the front surface. This state is the same when the camera is extended to a position where it can be photographed.

  On the other hand, the first group frame 5 and the second group frame 6 are similarly retracted to the retracted position according to the rotation and retraction of the rotating frame 3. The flare stop 8 and the shutter frame 7 are pressed backward by the rear surface of the lens holding portion of the first group frame 5 at the retracted position, and the biasing spring 10 and the biasing plate spring 9 are bent. The flare stop 8 approaches the shutter lid 46, and the shutter frame 7 has also moved to a position in close contact with the second group frame 6. In this retracted state, there is almost no gap in the direction of the optical axis O from the first group frame 3 to the CCD 23.

  In this retracted state, the shutter blade 47 is in the open position and the shutter opening is opened. A part of the second group lens 43 that forms a part of the photographing optical system enters the shutter opening and the opening 8 a of the flare stop 8. Thereby, the space | interval of the optical axis direction of each member in a retracted state can be narrowed, and a thinner lens frame can be realized.

  When the zoom motor 25 is driven in order to change from the retracted state to the wide state where photographing is possible, the rotating frame 3 is driven to rotate to the wide position where photographing is possible in the direction of the optical axis O as shown in FIG. The rectilinear guide frame 4 is fed out integrally with the rotation frame 3 in a rotation restricted state. On the other hand, the first group frame 5 and the second group frame 6 are extended to the wide position in the rotation restricted state as the rotation frame 3 rotates and extends. The shutter frame 7 moves to the position restricted by the claw portion 6 c with respect to the second group frame 6. Since the front side of the flare diaphragm 8 is also separated from the rear surface of the first group frame 5, the flare diaphragm 8 is separated from the shutter lid 46 to the diaphragm position by the urging force of the urging plate spring 9.

  Further, when the zoom motor 25 is driven to make the tele state, the rotary frame 3 is driven only in the rotational direction, and the first group frame 5 and the second group frame 6 are connected to the cam grooves 3e, 6 as shown in FIG. Move to the tele position along 3f. At that time, since the second group frame 6 is drawn out so as to approach the first group frame 5, the flare stop 8 is substantially in close contact with the urging plate spring 9 on the shutter lid 46 side as the urging plate spring 9 is bent. It becomes a state. Since the shutter frame 7 is pressed by the urging spring 10 having a stronger urging force than the urging plate spring 9, the shutter frame 7 is fed out together with the second group frame 6 in a state where the urging plate spring 9 is bent. .

  Thus, by making the urging force of the spring urging the flare stop 8 smaller than the urging force of the spring urging the shutter frame 7, the shutter frame 7 when the lens barrel 1 is in a shootable state is used. The position in the optical axis direction with respect to the second group frame 6 can be kept stable.

  On the other hand, when the focus motor 28 is driven to perform focusing, the feed screw shaft 16 is driven to rotate, and the third group frame 11 is driven to a focusing position corresponding to the subject distance.

  According to the lens barrel of the present embodiment, the rotary frame 3 is in a state in which both the front end surfaces 3g and 4g are exposed without covering the linear guide frame 4 at the front end thereof. The thickness of the frame member for covering the lens becomes unnecessary, the length of the lens barrel in the retracted state in the direction of the optical axis O can be shortened, and the lens barrel can be downsized (thinned).

  Further, the notch 4c on the linear guide frame 4 side for inserting the engaging projection 3c of the rotating frame 3 is covered with the front end surface 3g of the rotating frame 3, so that the entry of external light from the notch 4c is prevented. The Since the circumferential positions of the notch 4c and the first and second group guide grooves 4e and 4f are shifted, external light leaking from the fitting gap through the notch 4c reaches the first and second group guide grooves 4e and 4f. It can suppress entering.

  Further, since the configuration in which the flare diaphragm 8 is attached to the shutter frame 7 via a thin plate-like biasing plate spring 9 is employed, the flare is not generated when the first group frame and the second group frame 6 are separated from each other. The diaphragm 8 is separated from the second group frame 6 by an appropriate distance to function as a flare diaphragm, and in the retracted state, the flare diaphragm 8 is brought into close contact with the shutter lid 46 to reduce the occupied dimension in the optical axis O direction around the flare diaphragm. be able to.

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

  The lens barrel of the present invention has a simple configuration and can be used as a lens barrel capable of further thinning in a retracted state.

2 ... fixed frame 3 ... rotating frame 4 ... rectilinear guide frame 4d ... circumferential guide groove (circumferential groove)
3c ... engaging protrusion 4c ... notch (insertion opening)
4e ... First group guide groove (straight forward guide through groove)
4f ... Second group guide groove (straight forward guide through groove)

JP-A-8-313788 JP 2004-252365 A

Claims (3)

A fixed frame that supports the imaging unit;
A rotating frame that advances and retreats in the optical axis direction with respect to the fixed frame by rotating around the optical axis with respect to the fixed frame;
A rectilinear guide frame that is arranged inside the rotating frame, rotates relative to the rotating frame around the optical axis, and moves forward and backward by being integrally displaced in the optical axis direction;
A first group frame that is inserted inwardly of the linear guide frame so as to be capable of moving forward and backward, and that can be opened and closed at the front part ;
A second group frame inserted so as to be able to move forward and backward behind the first group frame inside the linear guide frame and holding a second group lens ;
In front of the second group frame inward of the rectilinear guide frame, the first group spring is biased forward in the optical axis direction by the first biasing spring with respect to the second group frame. A shutter frame that is configured to be relatively movably held and covered with a shutter lid.
In the center of the rectilinear guide frame, disposed in front of the shutter frame and between the first group frame and in contact with the rear surface of the first group frame that moves forward and backward in the optical axis direction. A flare stop with an opening,
Arranged between the shutter frame and the flare stop, a part is fixed to the shutter frame and the other part is fixed to the flare stop, and the flare stop is biased forward in the optical axis direction. And a flare throttling biasing spring
Comprising
When the first group frame is moved forward relative to the second group frame and the rear surface of the first group frame is disposed at a position where it does not contact the flare stop, the flare stop is It is biased toward the front in the optical axis direction by the flare stop biasing spring and is held in a state orthogonal to the optical axis at a position spaced apart from the shutter frame by a predetermined distance,
When the first group frame is moved rearward relative to the second group frame and reaches a settling state or a tele state, the flare stop resists the biasing force of the flare throttle biasing spring. A lens barrel that is pressed relatively rearward by the rear surface of the first group frame and is in close contact with the shutter frame with the flare stop biasing spring interposed therebetween . The flare stop has a thin ring shape with an opening formed in the center, the first group frame is moved forward relative to the second group frame, and the rear surface of the first group frame is the flare. When the flare stop is disposed at a position not in contact with the stop, the flare stop is urged forward by the flare stop urging spring in the optical axis direction and at a position separated from the shutter frame by a predetermined distance. 2. The lens barrel according to claim 1, wherein the lens barrel is held in an orthogonal state, and unnecessary light is shielded at a peripheral portion of an opening of the flare stop . The flare stop urging spring includes an attachment portion fixed to the shutter frame and an elastically deformable leaf spring portion connected to the attachment portion, and one end portion of the leaf spring portion is The lens barrel according to claim 1, further comprising a leaf spring portion fixed to the flare stop, and biasing the flare stop toward the front in the optical axis direction .

Images