JP3762652B2 - Zoom lens barrel feeding structure - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a feeding structure of a multistage zoom lens barrel having a barrier.
[0002]
[Prior art and its problems]
In recent years, zoom lenses of cameras have been desired to have a higher magnification as well as a smaller size. Therefore, the lens barrel is multistaged. When the lens barrel is multistaged, a helicoid feeding structure or a cam feeding structure is used as a structure for connecting the relatively moving lens barrels. The cam feeding structure is known to have a high degree of freedom in setting the amount of feeding with respect to the rotation angle of the lens barrel and a high degree of freedom in the feeding method, but it is known that it is difficult to ensure the rigidity of the lens barrel and to shield the light. On the other hand, it is known that the helicoid feeding structure has a fixed feeding amount with respect to the rotation angle of the lens barrel, but it is easy to ensure the rigidity of the lens barrel and to shield the light. Therefore, a helicoid feed structure is suitable for the multistage lens barrel. In order to open and close the barrier provided at the tip of the lens barrel, relative movement between the tip barrel to which the barrier is attached and the next-stage barrel is used.
However, when the number of stages of the lens barrels increases, the relative movement amount of each lens barrel decreases, and it becomes difficult to secure a barrier opening / closing stroke. In particular, in the case of a so-called wide zoom lens, since the total length of the optical system at the wide end is short, the amount of extension from the shortest storage position to the wide end other than the entire length of the lens barrel and the optical system is reduced. If a helicoid structure is used to solve this problem, the size of each lead is approximated and the amount of feeding is nearly equal in order to effectively utilize the length of the feeding lens barrel. Therefore, the stroke necessary for opening and closing the barrier cannot be secured.
[0003]
In order to solve this problem, the stroke can be secured if only the most advanced lens barrel is provided with a cam feeding structure and the other lens barrels are fed at a slight rotation angle so that they do not extend much. However, in this case, the lead for feeding the state-of-the-art lens barrel in the barrier open / close region becomes extremely large, and the resistance when the lens barrel is retracted in the storing direction becomes too large, resulting in insufficient strength. Produce. Further, when the state-of-the-art lens barrel alone is extended largely, there also arises a problem that the flexible printed circuit board connecting the shutter block mounted on the state-of-the-art lens barrel and the circuit board in the body is stretched.
[0004]
As another solution, the other lens barrels connected to the state-of-the-art lens barrel can be extended with a cam extension structure so that the feeding amount is reduced even if the lens barrel rotates, or it does not extend even if it rotates. If the section is provided, the stroke for opening and closing the barrier can be secured while the rotation angle is secured from the storage to the wide end. However, it is difficult for such a cam structure to ensure the rigidity of the lens barrel. In addition, if an idle section that does not extend even if it rotates due to the helicoid payout structure is provided, the position in the optical axis direction must be regulated in the idle section even if the idle section is not extended, and machining of this idle section is difficult. It was.
[0005]
OBJECT OF THE INVENTION
It is an object of the present invention to obtain a zoom lens barrel that can increase the rigidity of a multistage zoom lens barrel and can secure a sufficient stroke for barrier opening / closing drive.
[0006]
SUMMARY OF THE INVENTION
The present invention that achieves this object is a zoom lens barrel having a multistage feeding barrel, and each mirror from a barrel connected to a fixed portion of a camera body to a barrel to which a state-of-the-art barrel is connected. At least one of the cylinders is connected by a helicoid feed structure, the most advanced lens barrel and the rear lens barrel are connected by a cam feed structure, and the helicoid feed that connects the rear lens barrel and another lens barrel. the structure comprises a helicoid slip sections not fed be rotated between the up photographable shortest extended position from the retracted position of the zoom lens barrel, a helicoid feeding structure having the helicoid slip section has at one barrel A female helicoid formed and a male helicoid formed on the other lens barrel, and permitting the male helicoid to rotate in the circumferential direction when the one lens barrel and the other lens barrel are in the storage position. To form a helicoid slip section to the female helicoid, the circumferential groove formed along both the thrust surface facing the optical axis direction front-rear direction in the helicoid slip section, the longitudinal movement of the optical axis direction by the both thrust surface It is characterized by being regulated .
The present invention is particularly useful for a helicoid feeding structure provided with a helicoid ring formed by injection molding of a synthetic resin using a mold.
The invention according to claim 3 has a pair of lens barrels connected by a helicoid payout structure, the helicoid payout structure having a helicoid idling section that does not pay out even if rotated, and a helicoid payout having the helicoid idling section The structure includes a female helicoid formed on one lens barrel and a male helicoid formed on the other lens barrel, and the circumferential direction of the male helicoid when the one lens barrel and the other lens barrel are in a specific position. A helicoid idling section that allows rotation is formed in the female helicoid, and circumferential grooves are formed along both thrust surfaces facing from the front-rear direction of the optical axis in the helicoid idling section of the female helicoid . It is characterized by restricting back and forth movement in the optical axis direction .
[0007]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings. In this embodiment, the present invention is applied to a retractable four-stage zoom lens barrel.
[0008]
This zoom lens barrel is a collapsible four-stage barrel as shown in FIGS. 1 to 5, and a fixed barrel 12 fixed to the camera body and a relative support along the optical axis supported by the fixed barrel 12. As the four-stage paying lens barrels that move forward and backward, a first appearance cylinder 17, a second appearance cylinder 23, a third appearance cylinder (cam ring) 30, and a fourth appearance cylinder (lens support cylinder) 31 are provided.
In this zoom lens barrel, the first external lens barrel 17 with respect to the fixed external lens 12, the second external tube 23 with respect to the first external lens tube 17, and the third external tube with respect to the second external tube 23. 30 are respectively connected by a helicoid payout structure. The fourth appearance cylinder 31 is connected to the third appearance cylinder 30 by a cam structure. In the present embodiment, the first appearance cylinder 17 and the second appearance cylinder 23 are formed separately from the helicoid ring having the helicoid, and the zoom lens barrel is further extended from the tele end position where the zoom lens barrel is normally extended most. The first appearance cylinder 17 and the second appearance cylinder 23 are detachably formed at (disassembly / assembly position). The lens barriers 92 and 93 attached to the distal end portion of the fourth external cylinder 31 are the storage positions and the shortest payout positions (in the present embodiment, wide end positions) of the fourth external cylinder 31 and the third external cylinder 30 that can be photographed. Is driven to open and close by relative movement in the optical axis direction.
Furthermore, the zoom lens barrel of the present embodiment has a helicoid feeding structure that moves the second appearance cylinder 23 and the third appearance cylinder 30, and the second appearance cylinder 23 and the third appearance cylinder 30 between the storage position and the wide position. Is provided with an idling section that allows rotation but does not move in the optical axis direction. In other words, in the present embodiment, the second appearance cylinder 23 and the third appearance cylinder 30 have the idle rotation section that rotates at the same speed but does not move relative to the optical axis in the extended state from the housed state. In this idling section, the first appearance cylinder 17 rotates and moves in the optical axis direction, and the fourth appearance cylinder 31 does not rotate but moves in the optical axis direction relative to the third appearance cylinder 30, so that the fourth appearance cylinder The barriers 92 and 93 are driven to open and close by the relative movement of the cylinder 31 and the third appearance cylinder 30 in the optical axis direction.
[0009]
A more detailed overall structure of the zoom lens barrel will be described first with reference to FIGS. FIG. 1 is an exploded perspective view showing the main part of the zoom lens barrel. In this specification, the subject side is referred to as the front, and the camera body (film) side is referred to as the rear.
[0010]
The fixed cylinder 12 fixed to the camera body 11 has a female helicoid 12a formed on the inner peripheral surface thereof. A male helicoid 14a formed on the outer periphery of the first helicoid ring 14 is screwed into the female helicoid 12a. On the other hand, a pinion 16 that is rotationally driven by a zooming motor 15 is located outside the fixed cylinder 12. A part of the male helicoid 14 a is cut out on the pinion 16, and the male helicoids 14 a on both sides of the cut-out part are removed. A gear 14b formed on the outer periphery of the first helicoid ring 14 is meshed with each other. A first external cylinder 17 is coupled to the front portion of the first helicoid ring 14.
[0011]
The first helicoid ring 14 and the first outer cylinder 17 are rotated together by engagement of a coupling part 141 formed at the front end of the first helicoid ring 14 and a coupling part 171 formed at the rear end of the first outer cylinder 17. Combined to move. A first rectilinear guide ring 18 that supports relative rotation with the first appearance cylinder 17 and moves together in the optical axis direction (cannot move relative to the optical axis direction) is supported in the first appearance cylinder 17. Has been. The first linear guide ring 18, by linear guide projections 18a is engaged with the linear guide groove 12b of the fixed cylinder 12, to be only linear movement in the optical axis direction (forward and backward) without rotating with respect to the fixed barrel 12 It is supported .
[0012]
The first external cylinder 17 is formed with two circumferential grooves 172 extending in the circumferential direction on the inner circumferential surface, separated by a predetermined length in the optical axis direction, and the outer circumference of the first rectilinear guide ring 18 in each circumferential groove 172. A key 181 protruding from the surface is fitted. Accordingly, the first external cylinder 17 is restrained by the key 181 and the circumferential groove 172 and rotates relative to the first rectilinear guide ring 18, but is restricted so as to advance and retreat together in the optical axis direction. ing.
Accordingly, when the zooming motor 15 rotates, the first helicoid ring 14 rotates via the reduction gear train 15a, the pinion 16 and the gear 14b, and the first helicoid ring 14, the first external cylinder 17 and the first straight guide ring. 18 coupled bodies advance and retreat in the optical axis direction. At that time, the first helicoid ring 14 and the first outer cylinder 17 advance and retreat in the optical axis direction while rotating according to the leads of the female helicoid 12a and the male helicoid 14a, and the first straight guide ring 18 does not rotate and the first helicoid ring 14 is not rotated. And it advances and retreats in the optical axis direction together with the first appearance cylinder 17.
In addition, the coupling portion 141 and the coupling portion 171, the key 181 and the circumferential groove 172, the first helicoid ring 14 and the first appearance cylinder 17, the first appearance cylinder 17 and the first rectilinear guide ring 18 have a predetermined relative rotation. It is formed so that it can be engaged and disengaged by moving in the optical axis direction when it is at a corner (assembly / disassembly position).
As a step in which the moving position of the first rectilinear guide ring 18 relative to the fixed cylinder 12 in the optical axis direction is a stepwise zoom step, a brush 19 and a code plate 20 fixed to the first rectilinear guide ring 18 and the fixed cylinder 12 respectively. Detected by. A decorative ring 174 is fixed to the distal end portion of the first appearance cylinder 17.
[0013]
A female helicoid 18b is formed on the inner periphery of the first linear guide ring 18, and a male helicoid 21a formed on the outer periphery of the second helicoid ring 21 is screwed into the female helicoid 18b. The second helicoid ring 21 includes a pair of guide pieces 21b on its outer periphery, and each guide piece 21b is formed on the inner periphery of the first external cylinder 17 through a piece escape groove 18c formed in the first rectilinear guide ring 18. The frame guide groove 17a (FIGS. 6 and 8) is engaged. The top relief groove 18c is a through-hole having the same inclination as the female helicoid 18b, and the top guide groove 17a is a linear groove parallel to the optical axis O of the zoom lens system. The guide piece 21b is formed in a cylindrical shape with a circular cross section at the portion that passes through the piece escape groove 18c, but the tip portion that fits into the piece guide groove 17a has a rectangular cross section that is long in the direction in which the piece guide groove 17a extends. It is shaped like a straight key.
[0014]
A second appearance cylinder 23 is coupled to the front portion of the second helicoid ring 21. Similar to the first helicoid ring 14 and the first appearance cylinder 17, the second helicoid ring 21 and the second appearance cylinder 23 include a coupling portion (concave portion) 211 formed at the front end portion of the second helicoid ring 21 and a second appearance cylinder. 23 are coupled so as to rotate and advance / retreat integrally by engagement of a coupling portion (convex portion) 231 formed at the rear end portion of 23. Like the coupling portions 141 and 171, these coupling portions 211 and 231 are formed so as to be engageable and disengageable when the second helicoid ring 21 and the second external cylinder 23 are at a specific relative rotation angle (assembly / disassembly position). ing.
[0015]
A second rectilinear guide ring 25 that supports relative rotation with the second appearance cylinder 23 and moves together in the optical axis direction (cannot move relative to the optical axis direction) is supported in the second appearance cylinder 23. Has been. The second rectilinear guide ring 25 can be moved only in a relative rectilinear direction in the optical axis direction with respect to the first rectilinear guide ring 18 by engaging the rectilinear guide protrusion 25a with the rectilinear guide groove 18d of the first rectilinear guide ring 18. It is supported by.
[0016]
In the second external cylinder 23, two circumferential grooves 232 extending in the circumferential direction on the inner circumferential surface are formed apart from each other by a predetermined length in the optical axis direction, and the outer circumference of the second rectilinear guide ring 25 is formed in each circumferential groove 232. A key 251 protruding from the surface is fitted. Therefore, the second outer cylinder 23 is restrained by the key 251 and the circumferential groove 232 and rotates relative to the second rectilinear guide ring 25, but is restricted so as to advance and retreat together in the optical axis direction. ing.
[0017]
Therefore, when the zooming motor 15 rotates, the first helicoid ring 14 and the first external cylinder 17 move forward and backward while rotating through the reduction gear train 15a and the pinion 16, and the first rectilinear guide ring 18 does not rotate and the optical axis. Since it advances and retreats in the direction, the combined body of the second helicoid ring 21, the second appearance cylinder 23 and the second straight guide ring 25 advances and retreats in the optical axis direction. At this time, the second helicoid ring 21 and the second appearance cylinder 23 are brought together with the first appearance cylinder 17 with respect to the first appearance cylinder 17 by the engagement relationship between the guide piece 21b, the piece escape groove 18c and the piece guide groove 17a. The second rectilinear guide ring 25 has a rectilinear guide protrusion 25a and a rectilinear guide groove 18d. The second rectilinear guide ring 25 advances and retreats relative to the first appearance cylinder 17 in accordance with the leads of the male helicoid 21a and the female helicoid 18b. It moves forward and backward together with the second helicoid ring 21 and the second appearance cylinder 23 without being restricted by the engagement with the second helicoid ring 21.
In addition, the coupling portion 211 and the coupling portion 231, the key 251 and the circumferential groove 232, the second helicoid ring 21 and the second appearance cylinder 23, and the second appearance cylinder 23 and the second rectilinear guide ring 25 have a predetermined relative rotation. It is formed so that it can be engaged and disengaged by moving in the optical axis direction when it is at a corner (assembly / disassembly position).
[0018]
Similar to the first rectilinear guide ring 18, a female helicoid 25 b is formed on the inner peripheral surface of the second rectilinear guide ring 25, and the rear end portion outer periphery of the third appearance cylinder (cam ring) 30 is formed on the female helicoid 25 b. The male helicoid 30a formed in the above is screwed. The third outer cylinder 30 also serves as a third helicoid ring, and has a pair of guide pieces 30b on the outer periphery of the rear end thereof. Each guide piece 30b penetrates a piece relief groove 25c formed in the second straight guide ring 25. Then, it engages with a frame guide groove 23a formed on the inner periphery of the second appearance cylinder 23 (FIGS. 8 and 14). The guide piece 30b is formed in a cylindrical shape with a circular cross section at a portion that passes through the piece escape groove 25c, but a portion that fits into the piece guide groove 23a is formed in a rectangular shape that is long in the direction in which the piece guide groove 23a extends. Has been.
The top relief groove 25c is a through hole having the same inclination as the female helicoid 25b, and the top guide groove 23a is a linear groove parallel to the optical axis O.
[0019]
A third rectilinear guide ring 33 that supports relative rotation with the third appearance cylinder 30 and moves together in the optical axis direction (cannot move relative to the optical axis direction) is supported in the third appearance cylinder 30. Has been. The third rectilinear guide ring 33 is formed with a plurality of rectilinear guide protrusions 33a on the outer periphery, and each rectilinear guide protrusion 33a engages with the rectilinear guide groove 25d on the inner periphery of the second rectilinear guide ring 25, so that the optical axis direction Only straight movement is possible.
[0020]
Therefore, when the zooming motor 15 rotates, the first helicoid ring 14 and the first appearance cylinder 17 move forward and backward in the optical axis direction while rotating, and the first straight guide ring 18 does not rotate and the first helicoid ring 14 and the first outer ring 17 rotate. The second helicoid ring 21 and the second outer cylinder 23 move forward and backward relative to the first outer cylinder 17 at the same rotational speed while moving forward and backward in the optical axis direction together with the outer cylinder 17. Since the second rectilinear guide ring 25 does not rotate and advances and retreats together with the second helicoid ring 21 and the second appearance cylinder 23, the third appearance cylinder 30 and the third rectilinear guide ring 33 have the guide piece 30b and the piece escapement. Due to the coupling relationship between the groove 25c and the frame guide groove 23a, the second outer cylinder 2 rotates together at the same rotational speed as the second outer cylinder 23 and follows the lead of the male helicoid 30a and the female helicoid 25b. The third rectilinear guide ring 33 is restricted by the engagement of the rectilinear guide protrusion 33a and the rectilinear guide groove 25d and does not rotate with the third appearance cylinder 30 in the optical axis direction. Move forward and backward. In addition, as for the 3rd external appearance cylinder 30, the front part is exposed from the 2nd external appearance cylinder 23 rather than the part in which the helicoid 30a was provided, and comprises the external appearance of a lens barrel.
[0021]
Also in the third appearance cylinder 30, a fourth appearance cylinder (lens support cylinder) 31 having a first variable magnification lens group (first sub group S1, second sub group S2) L1, in order from the front, The rear lens group frame 32 to which the 2 zoom lens unit L2 is fixed is located, and the fourth outer cylinder 31 and the rear lens group frame 32 are guided in a straight line in the optical axis direction by the third straight guide ring 33. . Specifically, as shown in FIGS. 9 and 10, the three partial cylindrical arm portions 33 b constituting the third rectilinear guide ring 33 have optical axes O on the front and back surfaces (outer peripheral surface and inner peripheral surface). The linear guide grooves 33c and 33d are formed in parallel with each other, and linear guide protrusions (not shown) provided on the inner periphery of the fourth external cylinder 31 are slidably fitted in the linear guide grooves 33c. A rectilinear guide protrusion 32a provided on the outer periphery of the rear lens group frame 32 is slidably fitted in the guide groove 33d.
[0022]
A bottomed cam groove 35 and a bottomed cam groove 36 for the fourth appearance cylinder 31 and the rear lens group frame 32 are formed on the inner peripheral surface of the third appearance cylinder 30. FIG. 12 shows the developed shape of the bottomed cam grooves 35 and 36. Three sets of the bottomed cam groove 35 and the bottomed cam groove 36 are formed at equiangular intervals in the circumferential direction. The bottomed cam groove 35 and the bottomed cam groove 35 are provided on the fourth outer cylinder 31 and the rear lens group frame 32. Follower protrusions 31a and 32b that fit into the bottom cam groove 36 are formed to protrude in the radial direction.
Therefore, the fourth appearance cylinder 31 and the rear group lens frame 32 are arranged in the optical axis direction while the zooming motor 15 rotates and the third appearance cylinder 30 rotates together with the first appearance cylinder 17 and the second appearance cylinder 23. When the third rectilinear guide ring 33 does not rotate and moves forward and backward in the optical axis direction together with the third external appearance cylinder 30, the rectilinear guide protrusion (not shown) and the rectilinear guide groove 33c engage with each other. Without rotating, the follower protrusions 31a and 32b and the bottomed cam grooves 35 and 36 are moved forward and backward in the optical axis direction with a predetermined locus with respect to the third appearance cylinder 30. The fourth external cylinder 31 projects from the third external cylinder 30 in front of the rear end portion on which the follower protrusion 31a is protruded and is exposed to the outside to constitute the external appearance of the lens barrel.
[0023]
In the zoom lens barrel, the first rectilinear guide ring 18, the second rectilinear guide ring 25, the third rectilinear guide ring 33, and the fourth appearance cylinder 31 do not rotate relative to the fixed cylinder 12 in the optical axis direction. It is the structure which advances / retreats linearly (straight).
[0024]
In FIG. 12, each of the bottomed cam groove 35 and the bottomed cam groove 36 is a normal use region from the tele end position (T end) to the storage position (storage). The follower protrusion 31a and the follower protrusion 32b are guided between the position (T end) and the wide end position (W end). The bottomed cam groove 36 has an intermediate discontinuous position 36a between the tele end position (T end) and the wide end position (W end). The first variable power lens unit L1 in the fourth outer cylinder 31 guided by the bottomed cam groove 35 is positioned between the first sub group S1 and the second sub group S2 in the middle of the tele end position and the wide end position. And a switching function for moving the first variable magnification lens unit L1. When the first variable magnification lens unit L1 is switched, the second variable magnification lens unit L2 passes through the intermediate discontinuous position 36a of the bottomed cam groove 36. The section of the intermediate discontinuous position 36a is controlled so as not to be used for photographing as an actual zooming area (the third appearance cylinder 30 is not stopped).
The bottomed cam grooves 35 and 36 have a region extending from the tele end position to the disassembly / assembly position. That is, the zoom lens barrel is assembled and disassembled while being rotated to the disassembly / assembly position.
[0025]
"Shutter block"
A shutter block 40 is provided in the fourth appearance cylinder 31. A front sub group frame 45 and a rear sub group frame 46 are fitted in the shutter block 40. The first sub group S1 is fixed to the front sub group frame 45, and the second sub group S2 is fixed to the rear sub group frame 46. The front sub-group frame 45 (first sub-group S1) and the rear sub-group frame 46 (second sub-group S2) are optically moved between the wide end and the tele end by a focusing cam mechanism driven by a forward / reverse drive motor 53. The relative position in the axial direction is switched between two positions, a wide approach position and a tele approach position. In each position, the forward / reverse drive motor 53 further advances and retracts in the optical axis direction via the focusing cam mechanism and is used for focusing.
Further, in the shutter block 40, a lens shutter device having a shutter sector 60 and an aperture mechanism having an aperture sector 62 are provided behind the second sub group S2. In this zoom lens barrel, the shutter sector 60 is a blade that has both a variable aperture function for determining an arbitrary aperture value and a shutter function, and the opening amount (aperture value) of the shutter sector 60 according to the exposure value at the time of shutter release. Value) and opening time (shutter speed) are electrically controlled via the control circuit 81. On the other hand, the aperture sector 62 is provided to restrict the maximum value of the photographing aperture diameter particularly at the wide side photographing distance, and the opening amount is mechanically changed according to the extended state of the entire zoom lens barrel. That is, the size of the aperture is regulated so that the periphery of the zoom lens system is not used for shooting at the wide shooting distance.
[0026]
The aperture drive ring 63 for opening and closing the aperture sector 62 has a driven projection 63b on its outer periphery, and the driven projection 63b is formed on the inner periphery of the partial cylindrical arm portion 33b of the third rectilinear guide ring 33. 71 is engaged (FIG. 10). During zooming, the third rectilinear guide ring 33 and the shutter block 40 (aperture driving ring 63) move relative to each other in the optical axis direction. Then, the driven projection 63b is moved in the circumferential direction according to the aperture control cam groove 71, the aperture drive ring 63 rotates, and the opening degree of the aperture sector 62 changes.
As shown in FIG. 11, the aperture control cam groove 71 includes a linear restriction part 71 a parallel to the optical axis O, an inclination restriction part 71 b inclined with respect to the optical axis O, and a front end part of the third rectilinear guide ring 33. The straight-line restricting portion 71a and the inclination restricting portion 71b have such a width that the driven projection 63b can be fitted with almost no play.
[0027]
The electrical components of the shutter block 40 and the control circuit 81 (FIG. 13) in the camera body are connected by a shutter block FPC (flexible printed circuit board) 80. The shutter block FPC 80 changes the folding position in accordance with the change in the relative position of the shutter block 40 and the control circuit 81 due to the operation of extending and retracting the zoom lens barrel, and avoids interference with other lens barrel components. It is folded back in a letter shape and stored between the external cylinders (see FIG. 2).
In the shutter block FPC 80 of the present embodiment, the folded portions 801 and 802 folded in a hairpin shape have a gap between the first appearance cylinder 17 and the first rectilinear guide ring 18 and the second appearance cylinder from the rear to the front. 23 and the second rectilinear guide ring 25 are inserted into the gap from the rear to the front, and the folded portion 802 extending from the second appearance cylinder 23 and the second rectilinear guide ring 25 straddles the third appearance cylinder 30 in the fourth direction. It enters the external cylinder 31 and is connected to the shutter block 40.
[0028]
"Operation of the entire zoom lens barrel"
When the zoom lens barrel having the above configuration is driven to rotate the pinion 16 via the zooming motor 15,
The first helicoid ring 14 and the first appearance cylinder 17 advance and retreat while rotating, and the first linear guide ring 18 does not rotate and advances and retreats in the optical axis direction together with the first helicoid ring 14 and the first appearance cylinder 17.
The second helicoid ring 21 and the second appearance cylinder 23 are relatively moved forward and backward in the optical axis direction while rotating at the same rotational speed with respect to the first appearance cylinder 17, and the second straight guide ring 25 does not rotate and the second helicoid is rotated. Advancing and retracting in the optical axis direction together with the ring 21 and the second appearance cylinder 23,
The third appearance cylinder 30 moves relative to the optical axis direction while rotating at the same rotational speed with respect to the second appearance cylinder 23, and the third rectilinear guide ring 33 does not rotate, and the third appearance cylinder 30 does not rotate. Move forward and backward in the axial direction,
Since the fourth appearance cylinder 31 does not rotate and relatively advances and retreats in the optical axis direction (the third appearance cylinder 30 rotates relative to the fourth appearance cylinder 31),
Eventually, the fourth appearance cylinder 31 (first variable magnification lens unit L1) and the rear group lens frame 32 (second variable magnification lens group L2), which are guided straight in the optical axis direction within the third appearance cylinder 30, However, it moves relatively in the optical axis direction along a predetermined locus following the bottomed cam groove 35 and the bottomed cam groove 36.
[0029]
For example, in the lens barrel retracted state (collapsed state) of FIG. 2, the zoom lens barrel is substantially entirely stored in the camera body 11, and the zooming motor 15 is driven in the lens barrel feeding direction from the lens barrel retracted state. Then, the zoom lens barrel is extended to the wide end photographing position in FIG. The zoom lens barrel can be further extended from the wide end photographing position to the tele end photographing position in FIG. 4 by further driving the zooming motor 15 in the lens barrel feeding direction.
Then, when the zooming lens barrel is further driven in the lens barrel feeding direction at the telephoto end photographing position, the zoom lens barrel is extended to the disassembly / assembly position of the first appearance cylinder 17 and the second appearance cylinder 23 shown in FIG. Can be put out. FIG. 6 shows a state in which the first and second external cylinders 17 and 23 are removed at this disassembly / assembly position.
[0030]
When the zooming motor 15 is driven in the storage direction opposite to the feeding direction, the zoom lens barrel can be changed from the disassembled / assembled state and the tele end state to the wide end state and further to the storage (collapsed) state. The actual zooming is controlled stepwise so that focusing and exposure are performed by dividing the wide end to the tele end into a plurality of focal length steps and stopping the zooming motor 15 at each focal length step. At this time, since the region corresponding to the contact / separation switching between the first sub group S1 and the second sub group S2 is not used for photographing, the third appearance cylinder 30 (zooming motor 15) is stopped without dividing the step. I won't let you.
[0031]
In FIG. 14, the relationship between the second appearance cylinder 23, the second helicoid ring 21, the second linear guide ring 25, and the guide piece 30b in the storage position is shown as a development view viewed from the outside. In this storage position, a retaining key 251 formed circumferentially on the outer circumferential surface of the second rectilinear guide ring 25 engages with an inner circumferential groove 232 formed circumferentially on the inner circumferential surface of the second appearance cylinder 23. Thus, the second external cylinder 23 and the second helicoid ring 21 are regulated so as to be relatively rotatable and to move together in the optical axis direction. There are two retaining keys 251 at positions that are substantially spaced in the diameter direction on the same circumference, and two at positions that are spaced apart by a predetermined length in the optical axis direction and at positions that are spaced substantially in the diameter direction on the same circumference. It consists of a total of four. Further, the guide piece 30b is in the idling section 25c1 of the piece escape groove 25c.
[0032]
An idling section 25c1 of the top escape groove 25c is an idling section for idling the third appearance cylinder 30. That is, when the guide piece 30b enters the idling section 25c1, the guide piece 30b moves along the idling section 25c1 even if the third outer cylinder 30 rotates with respect to the second straight guide ring 25. There is no relative movement in the optical axis direction. The idling section 25c1 is provided in a section between the zoom lens barrel storage position and the wide end position.
[0033]
When the zooming motor 15 is rotated in the feeding direction from this stowed position and the telescopic end position is reached, the relationship between the second external cylinder 23, the second helicoid ring 21, the second linear guide ring 25 and the guide piece 30b is as follows. FIG. 15 is an exploded view similar to FIG. In the second outer cylinder 23 and the second linear guide ring 25 at the tele end position, a part of each retaining key 251 exits from the circumferential groove 232 and enters a cut 233, but a part of each retaining key 251 is provided. Is in the circumferential groove 232 so that the second external cylinder 23 does not move (does not come out) in the optical axis direction with respect to the second linear guide ring 25, that is, it rotates relative to the optical axis direction. Are engaged to advance and retreat together.
[0034]
The relationship between the second external cylinder 23, the second helicoid ring 21, the second linear guide ring 25, and the guide piece 30b that has reached the disassembly / assembly position by further rotating the zooming motor 15 in the extending direction from the tele end state is shown in FIG. 16 is developed in the same manner as FIG. In this disassembly / assembly position, each retaining key 251 exits from the circumferential groove 232 and enters the cut 233. Therefore, at this disassembly / assembly position, the second external cylinder 23 can be moved in the optical axis direction with respect to the second linear guide ring 25. That is, the second external cylinder 23 can be removed (FIG. 17) and attached (FIG. 16).
[0035]
When the first and second external cylinders 17 and 23 are pulled out at this disassembly / assembly position, the guide pieces 21b and 30b are exposed (FIG. 6), and when the guide pieces 21b and 30b are further removed (FIG. 7), the third external appearance is obtained. The helicoid is formed so that the cylinder 30, the second helicoid ring 21, and the first helicoid ring 14 can be further rotated in the feeding direction and removed. That is, the zoom lens barrel can be disassembled at the disassembly / assembly position.
The zoom lens barrel is assembled to the camera body, and in a completed state where photography is possible, the rotation of the zooming motor 15 is controlled so that it is not extended from the tele end position toward the disassembly / assembly position direction. When a special command is input for repair or the like, the zooming motor 15 rotates beyond the tele end position to the disassembly / assembly position.
[0036]
In the present embodiment, similarly to the second appearance cylinder 23 and the second rectilinear guide ring 25, the first appearance cylinder 17 and the first rectilinear guide 18 also have the circumferential groove 172, the inner circumferential groove cut 173, and the retaining key 181. In addition, the first external cylinder 17 can be disassembled / assembled with respect to the first rectilinear guide 18 at the disassembly / assembly position.
[0037]
"Lens barrier"
A lens barrier mechanism that opens and closes the lens barrel opening in front of the first variable magnification lens unit L1 is further provided at the tip of the fourth appearance tube 31. The lens barrier mechanism includes a decorative plate 90 fixed to the front portion of the fourth appearance cylinder 31, a barrier drive ring 91 supported on the front wall portion 31b of the fourth appearance cylinder 31 so as to be rotatable about the optical axis O, Between the barrier driving ring 91 and the decorative plate 90, a pair of outer barriers 92 and a pair of inner barriers 93 pivotally supported are provided. The decorative plate 90 is provided with a projection (not shown) that rotatably supports the outer barrier 92 and the inner barrier 93. The outer barrier 92 and the inner barrier 93 rotate around the projection and interlock with each other. The opening of the decorative board 90 is opened and closed. Each barrier 92, 93 is constantly urged in the closing direction by a barrier urging spring 94.
[0038]
The barrier drive ring 91 has barrier engaging projections 91a provided at two locations in the diameter direction, and a driven arm portion 91b extending rearward in the optical axis direction. The barrier engaging protrusion 91 a engages with the outer barrier 92 or the inner barrier 93 and transmits the rotation of the barrier driving ring 91 to the barriers 92 and 93. On the other hand, the driven arm portion 91 b is inserted into the fourth appearance cylinder 31 through a through hole (not shown) formed in the front wall portion 31 b of the front inner peripheral surface of the fourth appearance cylinder 31 . An inclined guide surface 33e is formed at the tip of the partial cylindrical arm portion 33b of the third rectilinear guide ring 33 so as to be slidable in contact with the driven arm portion 91b .
[0039]
The barrier drive ring 91 is urged to rotate by a drive ring urging spring 95 in a direction to open the barriers 92 and 93. The driving ring biasing spring 95 has a stronger biasing force than the barrier biasing spring 94, and the driving ring biasing spring 95 is in a free state in which the barrier driving ring 91 can be rotated by the biasing force of the driving ring biasing spring 95. The urging force is transmitted to the barriers 92 and 93 via the barrier driving ring 91 and the barrier engaging projection 91a, and the barriers 92 and 93 are held in the open position against the urging force of the barrier urging spring 94. In the photographing state between the wide end in FIG. 3 and the tele end in FIG. 4, the driven arm portion 91b and the inclined guide surface 33e are not in contact with each other, the barrier drive ring 91 is in a free state, and the barriers 92 and 93 are It is held in the open position.
[0040]
In the process of moving the zoom lens barrel from the wide end position of FIGS. 3 and 32 to the storage position of FIGS. 2 and 31, the inclined guide surface (barrier drive surface) 33e (FIG. 9) of the third rectilinear guide ring 33 is moved. The barrier drive ring 91 comes into contact with the driven arm portion 91b of the barrier drive ring 91 to start sliding contact, and the barrier drive ring 91 is in a direction against the drive ring biasing spring 95 according to the shape of the inclined guide surface 33e, that is, the barriers 92, 93. It is forcibly rotated in a direction that allows rotation in the closing direction. Then, each barrier 92 and 93 released from the restriction by the barrier drive ring 91 is rotated to the closed position by the urging force of the barrier urging spring 94 and is held in the closed position.
[0041]
In the process in which the zoom lens barrel moves from the wide end position to the retracted position, the second appearance cylinder 23 rotates with respect to the third appearance cylinder 30, and the first appearance cylinder 17 rotates with respect to the second appearance cylinder 23. However, it has an idle section that does not move relative to the optical axis. In other words, before the zoom lens barrel as a whole reaches the storage position, in the present embodiment, the second external cylinder 23 emits light to the first external cylinder 17 before the fourth external cylinder 31 reaches the storage position for the third external cylinder 30. It reaches the axial storage position, enters the idling section, the second external cylinder 23 starts to move backward together with the first external cylinder 17, and then the third external cylinder 30 is in the optical axis direction with respect to the second external cylinder 23. The third external cylinder 30, the second external cylinder 23, and the first external cylinder 17 retreat to the storage position while rotating together, reaching the storage position and entering the idling section. Accordingly, the second appearance cylinder 23 and the third appearance cylinder 30 are almost simultaneously with or after the inclined guide surface 33e of the third rectilinear guide ring 33 comes into contact with the driven arm portion 91b of the barrier drive ring 91 to start sliding contact. By the relative movement of the fourth appearance cylinder 31 and the third appearance cylinder 30, that is, the third rectilinear guide ring 33, which enter the idling section in this order and move backward by the relative rotation of the third rectilinear guide ring 33 with respect to the fourth appearance cylinder 31. The barrier drive ring 91 is rotationally driven in the barrier closing direction.
[0042]
In the process in which the zoom lens barrel is extended from the retracted position to the wide end position, the first, second, and third appearance cylinders 17, 23, and 30 are extended in the optical axis direction while rotating together. Since the external appearance tube 23 and the third external appearance tube 30 are located in the idling section, the external appearance tube 23 and the third external appearance tube 30 are rotated in the wide end direction while rotating together with the first external appearance tube 17, and the fourth external appearance tube 31 does not rotate. Is extended toward the wide end. In this idling section, the inclined guide surface 33e of the third rectilinear guide ring 33 moves in a direction away from the driven arm portion 91b, so that the barrier drive ring 91 rotates in the barrier opening direction by the biasing force of the drive ring biasing spring 95. The barriers 92 and 93 are rotated to the open position by the biasing force of the drive ring biasing spring 95. Before reaching the wide end, the inclined guide surface 33e is separated from the driven arm portion 91b, and the barriers 92 and 93 are completely moved to the open position.
[0043]
Further, in the extension process from the storage position of the zoom lens barrel to the wide end position, first, the idling section of the third appearance cylinder 30 is completed, so that the relative extension of the third appearance cylinder 30 with respect to the second appearance cylinder 23 starts. Then, since the idling section of the second appearance cylinder 23 ends, the relative feeding of the second appearance cylinder 23 with respect to the first appearance cylinder 17 also starts.
[0044]
As described above, the barriers 92 and 93 are opened and closed with a stroke that depends on the relative movement in the optical axis direction between the fourth appearance cylinder 31 and the third appearance cylinder 30 between the storage position and the wide end position. There is also a configuration in which one or both of the 30 and the second appearance cylinder 23 are not provided with an idling section. However, if the stroke for opening and closing the barriers 92 and 93 is configured to be short, the driving torque becomes large, so a longer stroke is desirable. However, if the stroke is configured to be long, the rotation angle of the third external cylinder 30 required for opening and closing the barrier is preferred. Increases, and the protrusion amount of the fourth external cylinder 31 with respect to the camera body increases too much, which exceeds the lens extension amount necessary from the storage position to the wide end position.
Although the idling section can be provided only in the helicoid feeding structure of the third appearance cylinder 30, in this case, the stroke with respect to the lens barrel rotation angle required for the lens feeding from the storage position to the wide end position becomes small. It is necessary to increase the rotation angle. That is, the relative movement distance of the fourth appearance cylinder 31 in the optical axis direction with respect to the third appearance cylinder 30 becomes long, and this portion is stretched unless the play of the portion straddling the third appearance cylinder 30 of the shutter block FPC 80 is increased. (Figs. 2 and 3).
Therefore, in the embodiment of the present invention, a helicoid idling section is provided in the second appearance cylinder 23 and the third appearance cylinder 30 to increase the rotation angle from the storage position to the wide end position, and the cam of the fourth appearance cylinder 31 is extended. Even if the lead is small, the relative movement distance in the optical axis direction of the fourth external cylinder 31 relative to the third external cylinder 30 can be increased.
[0045]
The configuration of the helicoid idling section will be described with reference to FIGS. 18A is a perspective view showing the second rectilinear guide ring 25 in a longitudinal section, FIG. 18B is a perspective view showing the first rectilinear guide ring 18 in a longitudinal section, and FIG. 19 is a second rectilinear guide ring 25. 20 to 22 are developed views showing the relationship between the second rectilinear guide ring 25 and the third appearance cylinder (cam / helicoid ring) 30, FIG. 23 is a developed view of the first rectilinear guide ring 18, and FIG. FIG. 26 to FIG. 26 are development views showing the relationship between the first straight guide ring 18 and the second helicoid ring 21 . 27A, 27B , and 27C, the relationship between the female helicoid 18b of the first rectilinear guide ring 18, the helicoid idling section 18b1, and the male helicoid 21a of the second helicoid ring 21 is shown expanded. .
[0046]
The female helicoid 25b on the inner peripheral surface of the second rectilinear guide ring 25 is a wide (wide in the circumferential direction) helicoid idling section 25b1 near the rear end (camera body side) of the second rectilinear guide ring 25 ( (See FIG. 19). The length in the optical axis direction of the helicoid idling section 25b1 and the length in the optical axis direction of the male helicoid 30a of the third appearance cylinder 30 are substantially matched. That is, when the male helicoid 30a enters the helicoid idling section 25b1, the restraint by the flank surfaces of the male and female helicoids 30a and 25b is released, and the second rectilinear guide ring 25 and the third appearance cylinder 30 move in the optical axis direction. Is restricted, and it becomes a coupled state in which relative rotation is possible. In frame escape groove 25c, slip sections 25c1 to permit rotation in this helicoid slip sections 25 b1 is formed.
[0047]
When the zoom lens barrel is in the retracted position, the male helicoid 30a that is helicoid-coupled to the female helicoid 25b is guided into the helicoid idle section 25b1, and the guide piece 30b that fits into the top relief groove 25c is within the idle section 25c1. It has been induced (FIG. 20). When the zoom lens barrel is extended from the retracted position in the wide end direction, the third external appearance cylinder 30, the male helicoid 30a, and the guide piece 30b are relative to the second rectilinear guide ring 25 in the wide direction (right direction in the drawing). Move on. Since the male helicoid 30a is constrained by the helicoid idling section 25b1, the third outer cylinder 30 only rotates relative to the second rectilinear guide ring 25 and reaches the idling section boundary position (FIG. 21). At the idle section boundary position, the flank surface of the male helicoid 30a is in contact with the flank surface of the female helicoid 25b.
[0048]
When the zoom lens barrel is extended further from the idling boundary position toward the wide position, the third outer appearance cylinder 30 is restrained by the female helicoid 25b in the third outer appearance cylinder 30 because the male helicoid 30a is restrained by the female helicoid 25b. While rotating according to the lead of 25b, it relatively moves forward (moves upward in the figure) and reaches the wide end position (FIG. 22).
[0049]
In the present embodiment, the third external cylinder 30 is a male helicoid 30a and the second rectilinear guide ring 25 is a female helicoid 25b, but the relationship between the male and female helicoids may be reversed.
[0050]
Similarly to the second rectilinear guide ring 25 and the third appearance cylinder 30, the first rectilinear guide ring 18, the second appearance cylinder 23, and the second helicoid ring 21 also have an idling section. The female helicoid 18b on the inner peripheral surface of the first rectilinear guide ring 18 is a helicoid idling section 18b1 that is wide (wide in the circumferential direction) near the rear end (camera body side) of the first rectilinear guide ring 18 ( FIG. 23). The length in the optical axis direction of the helicoid idling section 18b1 and the length in the optical axis direction of the male helicoid 21a of the second helicoid ring 21 are substantially matched. That is, when the male helicoid 21a enters the helicoid idling section 18b1, the restraint by the flank surfaces of the male and female helicoids 21a and 18b is released, and the first rectilinear guide ring 18 and the helicoid ring 21 (and the second external cylinder 23) Is in a coupled state in which relative movement is possible while movement in the optical axis direction is restricted. An idle section 18c1 without a lead corresponding to the helicoid idle section 18b1 is also formed in the top relief groove 18c.
[0051]
When the zoom lens barrel is in the retracted position, the male helicoid 21a that is helicoidally coupled to the female helicoid 18b is guided into the helicoid idle section 18b1, and the guide piece 21b that fits into the top relief groove 18c is within the idle section 18c1. It has been induced (FIG. 24, FIG. 27 (A)). When the zoom lens barrel is extended in the wide end direction from this storage position, the male helicoid 21a and the guide piece 21b, that is, the helicoid ring 21 and the second outer cylinder 23 are in the wide direction (see FIG. In the right direction). At the time of this relative movement, the male helicoid 21a enters the helicoid idling section 18b1 and the guide piece 21b enters the idling section 18c1, so that the second appearance cylinder 23 and the second helicoid ring 21 are in relation to the first rectilinear guide ring 18. Thus, only relative rotation is performed to reach the idle section boundary position (FIGS. 25 and 27B). At the idling section boundary position, the flank surface of the male helicoid 21a is in contact with the flank surface of the female helicoid 18b.
[0052]
When the zoom lens barrel is further extended from the idling boundary position in the wide position direction, the second outer cylinder 23 and the second helicoid ring 21 are restrained by the male helicoid 21a and the female helicoid 18b with respect to the first rectilinear guide ring 18. Therefore, it moves forward (moves upward in the figure) while rotating according to the leads of the male and female helicoids 21a, 18b and the top relief groove 18c, and reaches the wide end position (FIGS. 26 and 27C).
[0053]
In this embodiment, since it is not sufficient to open and close the barrier simply by rotating the second appearance cylinder 23, the third appearance cylinder 30 is also provided with an idling section. The idling amount of the third appearance cylinder 30 is set for the purpose of suppressing the feeding amount and adjusting the balance of feeding.
Further, in this embodiment, the rotation angle of the helicoid idling section 18b1 for idling the second appearance cylinder 23 and the helicoid ring 21 is set larger than the rotation angle of the helicoid idling section 25b1 for idling the third appearance cylinder 30. is there. When the third appearance cylinder 30 and the second appearance cylinder 23 are simultaneously switched from the idling section to the helicoid section, the load increases rapidly, so that this rapid increase in load can be mitigated.
[0054]
As described above, in this embodiment, the lens barrier is opened and closed by the idle movement of the third appearance cylinder 30 and the second appearance cylinder 23 and the relative movement of the fourth appearance cylinder 31 in the optical axis direction. As described above, in this zoom lens barrel, the fourth appearance cylinder 31 moves between the storage position and the wide end position, and the third appearance cylinder 30 and the second appearance cylinder 23 are between the storage position and the wide end position. Since the barrier drive ring 91 is driven to the barrier closed position and the barrier open position by the two actions of the rotation angle that idles in the idle section, the short stroke of the fourth appearance cylinder 31 can be compensated.
[0055]
In FIG. 28A, the first rectilinear guide ring 18 shown in an enlarged manner near the helicoid idling section 18b1 of the female helicoid 18b of the first rectilinear guide ring 18 is usually formed by injection molding of synthetic resin. If a die for this purpose is machined with an electrode for electric discharge machining , for example , the corner of the helicoid idling section 18b1 is rounded so-called cutter R (FIG. 28B). When such a cutter R is attached to the corner of the helicoid idling section 18b1, the circumferential lengths of the thrust surfaces 18b2 and 18b2 of the helicoid idling section 18b1 are shortened and the contact area with the male helicoid 21a is also reduced. The thrust direction regulating force of the male helicoid 21a by the thrust surface 18b2 is weak and unstable.
Therefore, in this embodiment, circumferential grooves 18e are formed along the front and rear thrust surfaces 18b2 separated in the optical axis direction of the helicoid idling section 18b1, and the cutter R is deleted by the circumferential grooves 18e (FIG. 28 (C )). The width of the circumferential groove 18e (the width in the optical axis direction) is set to a width at which the cutter R can be deleted, that is, approximately the radius of the cutter R.
[0056]
In this embodiment, a circumferential groove 25e similar to the circumferential groove 18e of the first linear guide ring 18 is formed along the front and rear thrust receiving surfaces of the helicoid idling section 25b1 of the second rectilinear guide ring 25. ing.
[0057]
When the male helicoid 21a enters the female helicoid 18 from the helicoid idling section 18b1, if the second helicoid ring 21 and the first linear guide ring 18 are off-axis or tilted, the end surface of the male helicoid 21a In some cases, the female helicoid 18 cannot be brought into contact with the thrust surface 18b2. Therefore, in the embodiment of the present invention, fitting portions (convex portions) 18f and 25f are formed to project in the circumferential direction on the inner peripheral surface in the vicinity of the rear end portions of the first rectilinear guide ring 18 and the second rectilinear guide ring 25. (FIGS. 18A and 18B). The fitting portions 18f and 25f are fitted with no gap in a state in which the second helicoid ring 21 and the third outer cylinder 30 that have been retracted to the storage position are slidable (FIG. 29). And the 2nd helicoid ring 21 and the 3rd external appearance cylinder 30 rotate the idle rotation area, slidingly contacting the fitting parts 18f and 25f, respectively.
[0058]
Thus, since the positions of the male helicoids 21a and 30a in the diameter direction are regulated by the fitting portions 18f and 25f, the male helicoids 21a and 30a are smoothly and reliably transferred from the helicoid idling sections 18b1 and 25b1 to the female helicoids 18b and 25b. You can enter. Then, by the helicoid action, the second helicoid ring 21 and the third appearance cylinder 30 can be advanced and retracted while rotating from the wide end position (FIG. 30) to the tele end position.
[0059]
In the present embodiment, the fitting portions 18f and 25f protrude from the outer peripheral surfaces of the first linear guide ring 18 and the second linear guide ring 25, but the bottom surfaces of the helicoid idle regions 18b1 and 25b1 are gradually raised. It may be configured to eliminate play.
[0060]
【The invention's effect】
As is apparent from the above description, the present invention relates to a zoom lens barrel having a multistage feeding barrel having a helicoid feeding structure, in which the lens barrel rotates between the storage position of the zoom lens barrel and the shortest feeding position where photographing is possible. A helicoid idling section that does not extend even though the helicoid idling section area is composed of a female helicoid formed in one lens barrel and a male helicoid formed in the other lens barrel, and the one lens barrel and the other mirror A helicoid idling section allowing the male helicoid to rotate in the circumferential direction when the cylinder is in the retracted position is formed in the female helicoid, and the helicoid idling section is rotated along both thrust surfaces facing from the front-rear direction in the optical axis direction. forming a groove, since the controls backward and forward movement of the optical axis direction by the both thrust surface, light in a helicoid slip sections and spatial inversion interval The lens barrel part that obtained by regulating the direction position can be formed inexpensively and with high accuracy.
[Brief description of the drawings]
FIG. 1 is an exploded perspective view of components showing an embodiment of a zoom lens barrel to which the present invention is applied.
FIG. 2 is an upper half sectional view of the zoom lens barrel in a stored state.
FIG. 3 is an upper half sectional view of the zoom lens barrel in a wide-end shooting state.
FIG. 4 is an upper half cross-sectional view of the zoom lens barrel in a tele end photographing state.
FIG. 5 is a perspective view showing a state in which the zoom lens barrel is extended.
6 is a perspective view of the zoom lens barrel in a state in which a part of the lens barrel appearance member is removed from FIG. 5. FIG. 7 is a perspective view of the zoom lens barrel in a further disassembled state than FIG. FIG. 8 is a single perspective view of a first appearance cylinder and a second appearance cylinder.
FIG. 9 is a single perspective view of a third rectilinear guide ring.
FIG. 10 is an exploded perspective view showing a relationship between a third linear guide ring and a shutter block.
FIG. 11 is a development view of the third rectilinear guide ring showing the throttle control cam groove of the third rectilinear guide ring.
FIG. 12 is a development view of the inner surface of the cam ring, showing an example of the cam groove shape of the cam ring.
13 is a block diagram showing a control system of a zoom lens barrel whose entire structure is shown in FIGS. 2 to 4. FIG.
FIG. 14 is a development view showing the relationship among the second appearance cylinder, the second helicoid ring, the second linear guide ring, and the guide piece at the storage position of the zoom lens barrel.
FIG. 15 is a development view showing a relationship among a second appearance cylinder, a second helicoid ring, a second linear guide ring, and a guide piece at a tele end position of the zoom lens barrel.
FIG. 16 is a development view showing a relationship among a second appearance cylinder, a second helicoid ring, a second straight guide ring, and a guide piece at the disassembly / assembly position of the zoom lens barrel.
FIG. 17 is a development view showing the relationship between the second appearance cylinder, the second helicoid ring, the second linear guide ring, and the guide piece at the disassembly / assembly position of the zoom lens barrel with the second appearance cylinder removed. .
18A is a perspective view showing the second rectilinear guide ring 25 of the zoom lens barrel in a longitudinal direction, and FIG. 18B is a longitudinal view of the third rectilinear guide ring 18 of the zoom lens barrel. It is a perspective view.
FIG. 19 is a development view showing a second rectilinear guide ring of the zoom lens barrel.
20 is a development view showing the relationship between the female helicoid of the second rectilinear guide ring 25 and the male helicoid of the third appearance cylinder 30 in the retracted state of the zoom lens barrel. FIG.
FIG. 21 is a development view showing the relationship between the female helicoid of the second rectilinear guide ring 25 and the male helicoid of the third appearance cylinder 30 when the zoom lens barrel is extended to the idling section boundary position.
FIG. 22 is a development view showing the relationship between the female helicoid of the second rectilinear guide ring and the male helicoid of the third appearance cylinder when the zoom lens barrel is extended to the wide end position.
FIG. 23 is a development view showing a first straight guide ring of the zoom lens barrel.
FIG. 24 is a development view showing the relationship between the first rectilinear guide ring, the second appearance cylinder 23, and the second helicoid ring when the zoom lens barrel is in the retracted state.
FIG. 25 is a developed view showing the relationship between the first rectilinear guide ring, the second appearance cylinder 23, and the second helicoid ring when the zoom lens barrel is at the idling section boundary position.
FIG. 26 is a development view showing the relationship between the first rectilinear guide ring, the second appearance cylinder 23 and the second helicoid ring when the zoom lens barrel is extended to the wide end position.
FIG. 27 is a developed view showing the relationship between the female helicoid of the first straight guide ring, the helicoid idling section, and the male helicoid of the second helicoid ring of the zoom lens barrel, in which (A) is in the retracted state; (B) is an idle section boundary position, and (C) is a view showing a state when it is at the wide end position.
28A is a diagram schematically showing the shape of a female helicoid and a helicoid idling section of the first straight guide ring, FIG. 28B is a diagram for explaining a problem that occurs during mold production, and FIG. It is a figure which shows embodiment of this invention which solves this problem.
FIG. 29 is an upper half section of the storage state of the embodiment in which a convex portion extending in the circumferential direction is formed on the inner peripheral surface in the vicinity of the rear end portion of the first straight guide ring and the second straight guide ring of the zoom lens barrel; FIG.
FIG. 30 is a top view of a wide end photographing state of the embodiment in which a convex portion extending in the circumferential direction is formed on the inner peripheral surface in the vicinity of the rear end portion of the first straight guide ring and the second straight guide ring of the zoom lens barrel; FIG.
FIG. 31 is an enlarged top cross-sectional view of the vicinity of the shutter block in a state where the lens barrier is closed in the zoom lens barrel.
32 is a cross-sectional top view similar to FIG. 31 but showing a state in which the lens barrier is opened in the zoom lens barrel. FIG.
[Explanation of symbols]
L1 First variable lens group L2 Second variable lens group O Optical axis S1 First subgroup S2 Second subgroup 11 Camera body 12 Fixed cylinder 12a Female helicoid 12b Straight guide groove 14 First helicoid ring 14a Male helicoid 14b Gear 141 Coupling portion 15 Zooming motor 16 Pinion 17 First appearance cylinder 17a Top guide groove 171 Coupling portion 172 Inner circumferential groove 173 Inner circumferential groove cut 18 First rectilinear guide ring 18a Rectilinear guide projection 18b Female helicoid 18b1 Helicoid idling section 18b2 Thrust Surface 18c Frame relief groove 18d Straight guide groove 18e Circumferential groove 181 Retaining key 19 Brush 20 Code plate 20
21 second helicoid ring 21a male helicoid 21b guide piece 211 coupling portion 23 second appearance cylinder 23a top guide groove 231 coupling portion 232 inner circumferential groove 233 inner circumferential groove cut 25 second rectilinear guide ring 25a rectilinear guide projection 25b female helicoid 25b1 Helicoid idling section 25c Top relief groove 25d Straight guide groove 25e Circumferential groove 25f Fitting portion 30 Third appearance cylinder (cam ring)
30a Male helicoid 30b Guide frame 31 Fourth appearance cylinder (lens support cylinder)
31a follower projection 31b front wall portion 32 rear group lens frame 32a rectilinear guide projection 32b follower projection 33 third rectilinear guide ring 33a rectilinear guide projection 33b partial cylindrical arm portion 33c 33d rectilinear guide groove 33e inclined guide surface 35 36 bottomed cam groove 36a Intermediate discontinuous position 40 Shutter block 80 FPC (flexible printed circuit board) for shutter block
80A annular FPC
80B FPC
81 Control circuit 81A Focal length information 81B Subject distance information 81C Subject brightness information 91 Barrier drive ring 91a Barrier engagement protrusion 91b Driven arm portion 92 Outer barrier 93 Inner barrier 94 Barrier biasing spring 95 Driving ring biasing spring

Claims (3)

A zoom lens barrel having a multistage feeding barrel,
At least any one of the lens barrels from the lens barrel connected to the fixed portion of the camera body to the lens barrel to which the most advanced lens barrel is connected is connected by a helicoid feeding structure, Connect the lens barrel at the rear stage with the cam feeding structure,
The helicoid payout structure that connects the rear lens barrel and another lens barrel includes a helicoid idling section that does not extend even if it rotates between the storage position of the zoom lens barrel and the shortest payable shooting position,
The helicoid payout structure having the helicoid idling section includes a female helicoid formed in one lens barrel and a male helicoid formed in the other lens barrel, and the one lens barrel and the other lens barrel are in the storage position state. A helicoid idling section that allows circumferential rotation of the male helicoid at a certain time is formed in the female helicoid, and in the helicoid idling section, a circumferential groove is formed along both thrust surfaces facing from the front-rear direction in the optical axis direction , 3. A zoom lens barrel feeding structure characterized in that forward and backward movement in the optical axis direction is restricted by the two thrust surfaces . 2. The zoom lens barrel feeding structure according to claim 1, wherein the helicoid feeding structure having the helicoid idling section and the circumferential groove is a helicoid ring formed by injection molding of a synthetic resin by a mold. The helicoid payout structure has a pair of lens barrels connected by a helicoid payout structure, and the helicoid payout structure has a helicoid idling section that does not pay out even if rotated.
The helicoid payout structure having the helicoid idling section includes a female helicoid formed in one lens barrel and a male helicoid formed in the other lens barrel, and the one lens barrel and the other lens barrel are in a specific position. Sometimes, a helicoid idling section that allows circumferential rotation of the male helicoid is formed in the female helicoid, and in the helicoid idling section of the female helicoid, circumferential grooves are formed along both thrust surfaces facing from the front-rear direction in the optical axis direction. A zoom lens barrel feeding structure, characterized in that the zoom lens barrel is formed and restricted from moving back and forth in the optical axis direction by the two thrust surfaces .

Images