JP4668149B2 - Retractable camera lens barrel - Google Patents

Description

  The present invention relates to a retractable camera lens barrel provided with a zoom lens.

  Zooming is performed by changing the relative distance between the first lens group and the second lens group by the first motor, and the third lens group is held by the second motor arranged facing the lens barrel. A lens barrel for a camera in which the lens frame is moved to adjust the focus. When the camera is not used, the first motor accommodates all the lens groups in a fixed cylinder and is retracted. A lens barrel for a camera that is in a state is described in Patent Document 1 below. Further, the first motor performs zooming by changing the relative distance between the first lens group and the second lens group, and the second motor attached to the cylindrical member to which the first lens group is attached, A lens barrel for a camera in which a lens frame holding a first lens group is moved with respect to the tube member to perform focus adjustment. When the camera is not used, A lens barrel for a camera in which the lens group is accommodated in a fixed cylinder so as to be in a retracted state is described in Patent Document 2 below.

  In each of the camera lens barrels described in Patent Documents 1 and 2, a plurality of cam grooves having the same shape into which the follower pin of the rotating cylinder is inserted are formed inside the fixed cylinder. In addition, a plurality of cam grooves of a plurality of types for inserting the follower pins of the holding members of the lens groups are formed inside the rotating cylinder arranged inside the fixed cylinder, and the rotating cylinder is When rotated by the first motor, it is guided in the cam groove of the fixed cylinder and is also moved in the optical axis direction, and the holding member of each lens group is moved in the optical axis direction by each type of cam groove having a different shape. The relative positional relationship of all the lens groups in the optical axis direction is changed. As described above, according to the present invention, not only the rotating cylinder is rotated when each lens group is extended from the retracted state, retracted to the retracted state, or zooming is performed, but the cam groove of the fixed cylinder is also provided. Retractable camera lens barrels that are guided in the direction of the optical axis and are moved relative to the optical axis direction by cam grooves having different shapes. It is.

JP 2003-57705 A JP 2006-30291 A

  In the case of the lens barrel for a camera described in Patent Documents 1 and 2, the cam groove formed in the fixed cylinder or the rotating cylinder is formed as a so-called through groove drilled from the inner peripheral surface to the outer peripheral surface. Rather, it is formed as a so-called bottomed groove that only goes around the inner peripheral surface side of each cylindrical member. However, these cylinder members have recently been made of synthetic resin. Therefore, when these cam grooves are formed as bottomed grooves, it is extremely difficult in terms of molding to make the contact surface with the follower pin 90 ° with respect to the optical axis. Therefore, as shown in Patent Documents 1 and 2, normally, the contact surface with the follower pin is usually formed as an inclined surface of about 60 degrees with respect to the optical axis. Accordingly, the tip of the follower pin inserted into the cam groove is also formed to be a tapered surface having substantially the same angle.

  By the way, when an impact is applied to the camera by dropping or the like, a large force may be applied to each member holding the lens group in the optical axis direction. In particular, when the camera is carried in the shooting standby state in which the lens group is extended, the tip of the cylindrical member to which the first lens group is attached may hit another object. In that case, a large force is applied to the cylindrical member in the optical axis direction. Therefore, when a large force in the optical axis direction is applied to the member holding the lens group in this way, the member is bent and cam action is applied to the contact portion between the follower pin and the cam groove of the rotating cylinder. May occur and the follower pin may come off the cam groove. In addition, as described in Patent Document 2, in the case of a configuration in which the first lens group is also moved during focus adjustment, the first lens group is disposed in the cylindrical member to which the first lens group is attached. When the lens frame holding the lens is pushed toward the back of the lens barrel, it may come off from the guide pin.

  The present invention has been made to solve such problems, and an object of the present invention is to insert a plurality of follower pins provided on a member or the like holding each lens group. In a collapsible camera lens barrel having a kind of cam groove and having a cylindrical member that changes its relative position by rotation on the optical axis and movement in the optical axis direction An object of the present invention is to provide a collapsible camera lens barrel configured so that the follower pin does not come off the cam groove even when a large force in the optical axis direction is applied to the barrel by impact.

In order to achieve the above object, a retractable camera lens barrel of the present invention includes a first tube having a plurality of cam grooves of the same shape and fixed to a subject side of a main body member, A plurality of types of second cylinders arranged inside the one cylinder and guided in the cam groove of the first cylinder when moved by the driving means and moved in the optical axis direction to enter and exit the first cylinder; A third cylinder having a plurality of cam grooves each of which is arranged inside the second cylinder and forming at least one type of cam groove as a through groove among the plurality of types of cam grooves; the has a plurality of Foroapin inserted to a predetermined type of cam grooves are formed as through grooves in the third cylinder with holding the top first lens group disposed on the object side first When the three cylinders are rotated by the rotation of the second cylinder, the cam A fourth cylinder that is guided in the direction of the optical axis and disposed inside the third cylinder to hold the lens group, and a predetermined type of cam groove of the third cylinder is provided on the outer periphery. the relative position between the lens group including a plurality of said first lens group is moved by being guided by the cam groove in the optical axis direction when the has a Foroapin third cylinder is rotated inserted into And at least one moving member that performs zooming by changing.

In the retractable camera lens barrel described above, in the first cylinder, the main body member holds a focus adjustment drive unit and a focus adjustment lens group. A focus adjustment lens frame that is moved in the optical axis direction, and the moving member disposed on the subject side of the focus adjustment lens frame is a lens holding member that holds the lens group The lens group held by the lens holding member is photographed by driving means of the shutter device when the third tube is accommodated in the first tube. When retracted out of the optical path and disposed at the radial position of the focus adjustment lens frame, the accommodation space in the optical axis direction when retracted is advantageous.

In addition, a fifth cylinder is disposed inside the third cylinder and outside the fourth cylinder, and the fifth cylinder is inserted into a predetermined type of cam groove of the third cylinder in the outer peripheral portion. has a plurality of Foroapin that, when the third cylindrical is rotated, the third cylinder is guided in the cam groove with a smaller stroke than the fourth cylinder is moved in the optical axis direction When entering and exiting, it becomes a very advantageous configuration as a retractable camera lens barrel having a high magnification zoom ratio. Furthermore, it has a plurality of types of key grooves formed in a straight line parallel to the optical axis and is arranged inside the third cylinder, and the first cylinder is rotated only in the optical axis direction by the rotation of the third cylinder. A sixth cylinder that moves together with the three cylinders, and the fourth cylinder, the fifth cylinder, and the moving member are arranged inside the sixth cylinder, and when the third cylinder rotates, It may be guided by both each predetermined type of cam groove formed in the third cylinder and each key groove formed in the sixth cylinder and individually moved only in the optical axis direction. .

  In the retractable camera lens barrel described above, the fourth tube is screwed into a focus adjusting driving means and a lens frame holding the first lens group, and is rotated by the driving means. And a plurality of guide pins for guiding the lens frame to move in the optical axis direction when the lead screw rotates, and at least one of the guide pins includes the moving member. If a stopper member for preventing the lens frame from being detached is attached to the tip of the lens frame, even if a force is applied to the lens frame from the subject side, it may come off the guide pin. There is no.

  The present invention is also moved in the optical axis direction when rotated by a driving means such as a motor, and the members holding the respective lens groups are moved on the optical axis by a plurality of types of cam grooves. In the collapsible lens barrel provided with the cylindrical member in which the distance between the lens groups is changed, at least one type of cam groove provided in the cylindrical member is a through groove. It is possible to make the contact surface with the follower pin inserted into the surface 90 degrees with respect to the optical axis, even if a strong force in the optical axis direction acts on the member provided with the follower pin due to impact or the like. The follower pin will not be detached from the cam groove.

  The embodiment of the present invention will be described with reference to two illustrated examples. The retractable camera lens barrel according to the present invention can be used for both a camera using a silver salt film and a digital camera. However, all of the embodiments are applied to a digital camera. It is configured as a thing.

  This embodiment will be described with reference to FIGS. 1 to 8. FIG. 1 is a cross-sectional view showing a retracted state (camera is not used). FIG. 2 is a cross-sectional view of FIG. FIG. 2 is a view of the cam cylinder shown in FIG. 2 as viewed from the inside, and FIG. 2B is a view of the key cylinder shown in FIG. 1 as viewed from the inside. 3 is a plan view showing the member attached to the second moving member in the retracted state of FIG. 1 as viewed from the imaging apparatus side, and FIG. 4 is a drawing mechanism in the state of FIG. It is the top view which showed the holding member of the 3rd lens group clearly. 5 is a cross-sectional view showing a state in which the first to third lens groups are extended from the position of FIG. 1 to the wide-angle end photographing position, and FIG. 6 shows the state of FIG. It is the top view shown similarly. Further, FIG. 7 is a cross-sectional view showing the telephoto end photographing position of the first to third lens groups, and FIG. 8 shows that the diaphragm blade is predetermined from the maximum aperture opening control position shown in FIGS. It is the top view which showed the state act | operated to the aperture opening control position of this.

  1, FIG. 5, and FIG. 7 are not shown by cutting the exact same part, but are cut at different parts for convenience in order to facilitate understanding of the overall configuration with a small number of drawings. Or only a part of the configuration is shown in cross-sections at different locations. 3, 6, and 8 are illustrated with a cover plate 27 (to be described later) removed in order to facilitate understanding of the configuration of the blade chamber.

  First, the configuration of this embodiment will be described. A body member 1 shown in FIGS. 1, 5, and 7 is a member that is directly attached to a camera body, and an imaging device 2 is attached to a substantially central portion thereof. As is well known, the image pickup apparatus 2 includes a solid-state image pickup device such as a CCD. Usually, a filter plate such as a low-pass filter or a transparent cover plate is disposed on the subject side. As shown in FIG. 5, the motor mounting plate 3 is mounted with a reciprocating motor 4 and is mounted on the subject side surface of the main body member 1 with screws 5. A lead screw 6 is attached to the output shaft 4 a of the motor 4. The lens frame 8 holding the fourth lens group 7 for focus adjustment has the female screw of the nut member 9 attached thereto screwed into the male screw of the lead screw 6, and the motor 4 is rotated. If it does so, it will guide by the guide pin 1a standingly arranged by the to-be-photographed object side of the main body member 1, and will move the 4th lens group 7 to an optical axis direction. The motor 4 does not have to be completely accommodated in the lens barrel as in the present embodiment. For example, as described in Patent Document 1, only a part of the motor 4 may be accommodated. It may be installed outside the lens barrel.

  A fixed cylinder 10 made of synthetic resin is integrally attached to the surface of the body member 1 on the subject side by means not shown. As shown in FIG. 5, a shaft 11 is attached to the outside of the fixed cylinder 10 between the main body member 1 and the fixed cylinder 10, and there is a camera main body side (not shown). A gear 12 that is reciprocally rotated by a motor is attached. The gear 12 has a portion of the teeth formed on the outer periphery thereof inserted into the inside through a long hole of the fixed cylinder 10 formed in parallel with the optical axis. In addition, although the entire shape is not clearly shown, as is well known, on the inner peripheral surface of the fixed cylinder 10, a rotating cylinder 13 described later moves in the optical axis direction while rotating at angular positions at equal intervals. In order to make this possible, three cam grooves 10a having the same shape are formed as bottomed grooves. As can be seen from the cross-sectional shape of the cam groove 10a shown in FIG. 1, the surface of the rotating cylinder 13 that will be in contact with a follower pin 13b described later is 90 degrees with respect to the optical axis for reasons of molding. It cannot be formed on the surface, and is formed as an inclined surface of about 60 degrees. In addition, on the inner peripheral surface of the fixed cylinder 10, a key cylinder 15, which will be described later, can move linearly in the direction of the optical axis along with an integral movement of a rotating cylinder 13 and a cam cylinder 14 which will be described later. For this purpose, three key grooves 10b parallel to the optical axis are formed at angular positions that do not interfere with the cam grooves 10a, one of which is shown in FIG.

  A synthetic resin rotating cylinder 13 is arranged inside the fixed cylinder 10, and a synthetic resin cam cylinder 14 is arranged inside the fixed cylinder 10. The rotary cylinder 13 and the cam cylinder 14 are manufactured as separate members, but operate integrally after assembly. Therefore, first, as shown in FIG. 5, the rotating cylinder 13 of the present embodiment has a spur partial gear 13 a at the end on the imaging device 2 side over a predetermined angular range. Is engaged with the gear 12. Further, three follower pins 13 b are provided at angular positions at equal intervals on the outer peripheral surface of the rotating cylinder 13, and they are respectively fitted in the cam grooves 10 a provided in the fixed cylinder 10. Therefore, when the motor (not shown) reciprocates, the rotating cylinder 13 is reciprocated along with it, and is guided by the cam groove 10a of the fixed cylinder 10 so as to reciprocate in the optical axis direction. .

Next, the cam cylinder 14 integrated with the rotary cylinder 13 will be described. FIG. 2A is a diagram of the cam cylinder 14 as viewed from the inside, with the left side being the subject side and the right side being the imaging device 2 side. Although the shape of the surface in contact with the rotating cylinder 13 is not shown in detail in FIG. 2A, three inclined surfaces for connecting to a hole (not shown) formed inside the rotating cylinder 13 are shown. A protrusion 14a is shown. Then, this cam tube 14, the imaging device 2, the three hook portion 14b having flexibility, are formed at equal intervals in the angular position, one of them in cross-section in FIG. 7 It is shown. The cam cylinder 14 is formed with three types of cam grooves 14c, 14d, 14e, and 14f having different cam shapes, at three equal angular positions. Among them, the cam groove 14d is a through groove drilled from the inner peripheral surface to the outer peripheral surface, and the remaining three types of cam grooves 14c, 14e, and 14f are similar to the cam groove 10a of the fixed cylinder 10 described above. It is a bottomed groove that does not penetrate.

  The rotating cylinder 13 and the cam cylinder 14 are conventionally configured as one rotating cylinder. However, when configured as one rotating cylinder in this way, the shape of the cam grooves 14c, 14d, 14e, and 14f is the same as the cam groove 10a of the fixed cylinder 10 and the follower pin inserted into them. The contact surface must be formed so as to be an inclined surface of about 60 degrees with respect to the optical axis. However, in this embodiment, for the reasons described later, at least the shape of the cam groove 14d is to be formed so that the contact surface with the follower pin inserted therein is 90 degrees with respect to the optical axis. Therefore, at the part processing stage, the rotating cylinder 13 and the cam cylinder 14 are manufactured as two parts so as to meet such requirements, and both are integrated at the assembly stage.

  Note that the cam grooves 14c, 14e, and 14f are preferably formed as through-grooves in the same manner as the cam groove 14d. However, in this embodiment, as can be seen from FIG. 2 (a), the four cam grooves 14c, 14d, 14e, and 14f are formed so as to be close to each other. If it does, predetermined intensity | strength will no longer be obtained in the boundary part of cam grooves. Therefore, in this embodiment, only the cam groove 14d is a through groove. However, when the cam cylinder 14 is made of metal, all the cam grooves can be formed as a through groove. Even in the case of resin, two or more cam grooves may be used as through grooves depending on the form of cam grooves.

  A key cylinder 15 is disposed inside the cam cylinder 14 and is configured to move linearly in the optical axis direction when the cam cylinder 14 rotates together with the rotary cylinder 13. FIG. 2B is a view of the key cylinder 15 unfolded and viewed from the inside, with the left side being the subject side and the right side being the imaging device 2 side. An annular groove 15a is formed on the surface of the key cylinder 15 on the cam cylinder 14 side, and as shown in FIG. 7, the tip of the hook portion 14b formed on the cam cylinder 14 is formed there. Is included. The key cylinder 15 is formed with three keys 15b at equally spaced angular positions, and these are fitted in the key groove 10b of the fixed cylinder 10, as shown in FIG. For this reason, when the rotary cylinder 13 and the cam cylinder 14 are rotated in the optical axis direction by the cam groove 10a of the fixed cylinder 10, the key cylinder 15 is guided by the key groove 10b of the fixed cylinder 10 so that the optical axis It will be moved linearly only in the direction. In the key cylinder 15, four types of key grooves 15c, 15d, 15e, and 15f formed in parallel with the optical axis are formed through three at equal angular positions.

  An auxiliary cylinder 16 is disposed inside the key cylinder 15, and a rectilinear cylinder 17 is disposed inside the auxiliary cylinder 16. First, the auxiliary cylinder 16 will be described. As can be seen from FIG. 1, the auxiliary cylinder 16 is configured to enter and be stored between the key cylinder 15 and the rectilinear cylinder 17 by entering a thin portion formed inside the key cylinder 15. Further, three follower pins 16a are provided on the outer peripheral surface of the auxiliary cylinder 16 at equally spaced angular positions, and they pass through the key groove 15c of the key cylinder 15 so that their tips are connected to the cam cylinder. 14 with a bottomed cam groove 14c. Therefore, when the auxiliary cylinder 16 moves in the optical axis direction by the cam groove 10a of the fixed cylinder 10 while the rotating cylinder 13 and the cam cylinder 14 rotate, the follower pin 16a is guided to the cam groove 14c of the cam cylinder 14. However, since it is also guided by the key groove 15c of the key cylinder 15, it is moved linearly only in the optical axis direction. The amount of movement differs from the amount of movement of the rotating cylinder 13 and the cam cylinder 14 in the optical axis direction depending on the shape of the cam groove 14c.

  Next, the straight cylinder 17 will be described. Three follower pins 17 a are provided on the outer periphery of the rectilinear cylinder 17 at equally spaced angular positions. These follower pins 17 a penetrate the key groove 15 d of the key cylinder 15 and the cam groove 14 d penetrates the tip of the cam cylinder 14. Is fitted. For this reason, when the rotary cylinder 13 and the cam cylinder 14 rotate, the follower pin 17a is guided by the cam groove 14d and moves, but the linear cylinder 17 is also guided by the key groove 15d of the key cylinder 15. Therefore, it can be moved linearly only in the optical axis direction. The amount of movement differs from the amount of movement of the rotating cylinder 13 and the cam cylinder 14 in the optical axis direction depending on the shape of the cam groove 14d. In addition, a front plate 18 having a photographing optical path opening 18 a formed at a substantially central portion is attached to the subject side of the linearly-moving cylinder 17. , 21 are disposed, but the barrier mechanism is not directly related to the present invention, and therefore, a specific configuration is not illustrated and description thereof is omitted. A lens frame 23 holding the first lens group 22 is attached to the rectilinear cylinder 17 so as to be movable in the optical axis direction.

  Inside the key cylinder 15, a first moving member 24 and a second moving member 25 are arranged in order from the subject side. First, the first moving member 24 will be described. Three follower pins 24a (see FIG. 1) are provided at angular positions at equal intervals on the outer peripheral portion of the first moving member 24. These follower pins penetrate the key groove 15e of the key cylinder 15 and have their tips at the ends. The cam cylinder 14 is fitted in the bottomed cam groove 14e. Therefore, the first moving member 24 moves as the follower pin 24a is guided by the cam groove 14e when the rotating cylinder 13 and the cam cylinder 14 rotate, but is also guided by the key groove 15e of the key cylinder 15. Therefore, it can be moved linearly only in the direction of the optical axis. The amount of movement differs from the amount of movement of the rotating cylinder 13 and the cam cylinder 14 in the optical axis direction depending on the shape of the cam groove 14e. The first moving member 24 has a second lens group 26 attached to the lens holding portion 24b. Although only one is shown in FIG. 1, in order to prevent the upright portions of the three follower pins 24 a of the first moving member 24 from colliding with the straight cylinder 17, it is parallel to the optical axis. Three slot-shaped relief portions 17b formed in the above are formed.

  Next, the second moving member 25 will be described. Three follower pins 25a (see FIGS. 5 and 7) are provided on the outer peripheral portion of the second moving member 25 at equally spaced angular positions, and they pass through the key groove 15f of the key cylinder 15, The tip is fitted into the bottomed cam groove 14 f of the cam cylinder 14. For this reason, when the rotary cylinder 13 and the cam cylinder 14 rotate, the follower pin 25a is guided by the cam groove 14f to move the second moving member 25, but is also guided by the key groove 15f of the key cylinder 15. Therefore, it can be moved linearly only in the direction of the optical axis. The amount of movement differs from the amount of movement of the rotating cylinder 13 and the cam cylinder 14 in the optical axis direction depending on the shape of the cam groove 14f. A number of members are attached to the second moving member 25. The attachment configuration thereof will be described below mainly with reference to FIGS. Although only one is shown in FIGS. 5 and 7, the rectilinear cylinder 17 has a second portion similar to the escape portion with respect to the standing portion of the follower pin 24 a of the first moving member 24. In order to avoid collision with the upright portions of the three follower pins 25a of the moving member 25, three slot-shaped relief portions 17c parallel to the optical axis are formed.

  As shown in FIG. 1, a cover plate 27 is attached to the second moving member 25, and a blade chamber is configured between the two. In the blade chamber, a drive ring 28, three diaphragm blades 29, and two shutter blades 30 and 31, which will be described later, are arranged. In FIGS. Only the ring 28 is shown, and the three diaphragm blades 29 and the two shutter blades 30 and 31 are not shown. FIG. 3 is a plan view showing the second moving member 25 and the members attached thereto with the cover plate 27 removed, as viewed from the imaging device 2 side of FIG. FIG. 4 is a plan view showing only a diaphragm mechanism and a holding member of a third lens group in the state of FIG.

  As shown in FIG. 3, the second moving member 25 is provided with the three follower pins 25a described above on the outer peripheral portion thereof, and a circular opening portion 25b for the photographing optical path at the center portion thereof. have. However, the cover plate 27 (not shown) is also provided with a photographing optical path opening 27a having a diameter smaller than that of the opening 25b, as shown by a two-dot chain line. 27 is restricted by the opening 27a. 5 and 7, the cover plate 27 is provided with a stopper pin 27b on the image pickup apparatus 2 side. In FIG. 3, the stopper pin 27b is positioned at two positions. It is indicated by a dotted line.

  In the blade chamber formed between the second moving member 25 and the cover plate 27, in order from the second moving member 25 side, a drive ring 28, three diaphragm blades 29, two shutter blades 30, 31 is arranged. First, the drive ring 28 arranged so as to be rotatable about the optical axis has three through cam grooves 28a at equal angular positions, and has a pushing portion 28b and a predetermined portion on the outer peripheral portion. And a tooth portion 28c formed over the angular range. Each of the three diaphragm blades 29 has a blade shaft 29a and an engagement pin 29b on the second moving member 25 side, and the blade shaft 29a is a hole formed in the second moving member 25. The engaging pin 29b is inserted into the cam groove 28a of the drive ring 28. In FIGS. 3, 6 and 8, only one diaphragm blade is indicated by a reference numeral. is there. Further, the two shutter blades 30 and 31 are rotatably attached to two shafts 25c and 25d provided upright on the second moving member 25.

  The second moving member 25 includes, for example, a known step motor 32 as described in JP-A-2005-284102 and a known current control type as described in JP-A-2005-287159. The motor 33 is attached. Among them, the step motor 32 is for reciprocatingly rotating the drive ring 28, and the two yokes 32 c and 32 d around which the coils 32 a and 32 b are wound are attached to the subject side surface of the second moving member 25. The rotor 32f integrated with the output gear 32e is disposed on the blade chamber side. The output gear 32 f is meshed with a speed-reducing two-stage gear 34 meshed with the tooth portion 28 c of the drive ring 28. The current control type motor 33 includes a yoke 33b around which a coil 33a is wound and a rotor 33c. The motor 33 is attached to the subject side surface of the second moving member 25, and is integrated with the rotor 33c. The output pin 33d is inserted into the blade chamber and is fitted into both of the long holes formed in the shutter blades 30 and 31, as is well known.

  A shaft 25e is erected on the surface of the second moving member 25 on the imaging device 2 side and outside the blade chamber. The lens holding member 35 is secured to the shaft 25e by a screw 36 so as to be rotatable on the surface closer to the imaging device 2 than the cover plate 27. Further, the lens holding member 35 has a lens holding portion 35a, a pushed pin 35b provided on the subject side surface closer to the lens holding portion 35a, and a contact portion 35c provided at the tip. The third lens group 37 is attached to the lens holding portion 35a. The lens holding member 35 is biased so as to rotate counterclockwise in FIG. 3 by a spring 38 hung between the lens holding member 35 and the second moving member 25. 5 and 7, the illustration of the spring 38 is omitted.

  Next, the operation of this embodiment will be described. 1 and 3 show the camera not in use, and the first to fourth lens groups 22, 26, 37, and 7 are all fixed cylinders 10 as shown in FIG. It is housed inside and is in a so-called retracted state. At this time, as shown in FIG. 3, the two shutter blades 30 and 31 are rotated in opposite directions by the motor 33, and the opening 27a of the cover plate 27 restricting the exposure opening. Is fully open. The drive ring 28 is rotated to the extreme counterclockwise position by the step motor 32. Therefore, the three diaphragm blades 29 are rotated counterclockwise about the blade shaft 29a to fully open the opening 27a, and the lens holding member 35 is driven by its driven pin 35b. Pushed by the pushing portion 28b of the ring 28 and rotated clockwise against the biasing force of the spring 38, the third lens group 37 is retracted in the direction crossing the optical axis and at the same time. As can be seen from FIG. 1, the third lens group 7 is placed at the radial position. Therefore, in this embodiment, the accommodation dimension in the optical axis direction in the retracted state is extremely small.

  In order to change from such a retracted state to a state where photographing is possible, the power switch of the camera is turned on. As a result, a motor (not shown) is rotated, so that the rotary cylinder 13 and the cam cylinder 14 are rotated via the gear 12 shown in FIG. At this time, the rotary cylinder 13 and the cam cylinder 14 are moved not only to the rotation but also to the subject side, but the key cylinder 15, the auxiliary cylinder 16, the rectilinear cylinder 17, the first moving member 24, and the second moving member 25 are Since the key 15b of the key cylinder 15 is guided in the key groove 10b of the fixed cylinder 10, the key 15b is moved straight to the subject side without rotating. At this time, the rotating cylinder 13, the cam cylinder 14, and the key cylinder 15 move to the subject side at the same speed, but the auxiliary cylinder 16, the rectilinear cylinder 17, the first moving member 24, and the second moving member 25 are respectively Due to the shape of the cam grooves 14 c to 14 f of the cam cylinder 14, the cam cylinder 14 is moved faster than the rotary cylinder 13, cam cylinder 14, and key cylinder 15 as a whole.

  Further, when the second moving member 25 is moved toward the subject side and the third lens group 37 is moved closer to the subject side than the fourth lens group 7, a pulse is supplied to the step motor 32, and in FIG. Since the child 32 f is rotated clockwise, the drive ring 28 is rotated clockwise via the two-stage gear 34. In this way, when the drive ring 28 rotates in the clockwise direction, the pushing portion 28b tends to move away from the pushed pin 35b of the lens holding member 35, so that the lens holding member 35 follows this, The spring 38 rotates counterclockwise by the biasing force of the spring 38. Then, the rotation of the lens holding member 35 is stopped by the contact portion 35c at the tip contacting the stopper pin 27b of the cover plate 27, and the third lens group 37 is disposed on the optical axis. become.

On the other hand, the engagement pins 29b of the three diaphragm blades 29 are inserted into the three cam grooves 28a of the drive ring 28. The shape of these cam grooves 28a is such that the third lens group 37 is in the imaging optical path. The three aperture blades 29 are not rotated at all until the movement to is completed, or until they are retracted from the imaging optical path, because they are formed in an arc shape centered on the optical axis. Then, after the lens holding member 35 stops, the drive ring 28 is stopped at a slightly rotated position. FIG. 6 shows the state at that time, and the position in this state is the initial position for the drive ring 28.

  In this way, when the first to third lens groups 22, 26, and 37 are moved to the subject side, the motor 4 is also rotated and the fourth lens group 7 is connected via the lead screw 6. The lens frame 8 is also moved to the subject side. Then, the state in which all the lens groups are extended and stopped from the retracted state shown in FIG. 1 is the state shown in FIG. 5, and in this embodiment, this state is the standby for photographing at the wide angle end. State. In the process of changing from the state shown in FIG. 1 to the state shown in FIG. 5, the barrier plates 20 and 21 are operated via a mechanism (not shown) to open the opening 18a.

  Thus, in the state where all the lens groups are extended from the retracted state, most of the outer peripheral surface of the rotating cylinder 13 is exposed. If the rotating cylinder 13 and the cam cylinder 14 of this embodiment are configured as a single member as in the prior art, a cam groove corresponding to the cam groove 14d of this embodiment is formed as a through groove in the member. In this case, the cam groove is exposed in the state shown in FIG. Therefore, in the case of this embodiment, in order to form a through groove such as the cam groove 14d, such a conventional member is constituted by two members of the rotary cylinder 13 and the cam cylinder 14. ing.

  When performing zooming during shooting, the rotary cylinder 13 is rotated forward and backward by a motor (not shown) while looking through the zoom finder linked with the shooting lens, and the cam groove 14d formed in the cam cylinder 14 , 14e, 14f, the relative positional relationship between the first to third lens groups 22, 26, 37 is changed. In the focus adjustment, the lens 4 is moved to a predetermined position via the lead screw 6 by rotating the motor 4 forward and backward. FIG. 7 shows the photographing position at the telephoto end of each lens group controlled as described above.

  By the way, in this embodiment, in addition to the fourth lens group for focus adjustment, the zoom lens is composed of three groups in order to increase the zoom ratio. Compared to this case, since the first lens group 22 is largely extended toward the subject side, the length of the rectilinear cylinder 17 in the optical axis direction is longer as a whole. However, in such a case, when zooming or retracting, the end of the rectilinear cylinder 17 on the side of the image pickup device 2 is positioned so that the follower pin 24a of the first moving member 24 is raised or the second movement is performed. It will interfere with the standing part of the follower pin 25a of the member 25. Therefore, as described above, each of the rectilinear cylinders 17 has three slot-shaped reliefs so as not to interfere with the standing portions and to allow the standing portions to enter from the imaging device 2 side. Portions 17b and 17c are formed. However, in such a case, when the state shown in FIG. 7 is obtained, a part of the slot-like relief portions (see the relief portion 17c at the upper right end portion of the straight advance cylinder 17 in FIG. It will be exposed to the subject side rather than the end on the side. Therefore, in the case of the present embodiment, the auxiliary cylinder 16 is provided so as to cover the exposed slot-shaped escape portions 17b and 17c, thereby preventing light leakage to the inside. .

  Thus, after the zooming is performed, when the release button of the camera is pressed, the size of the aperture opening is first determined by the photometry circuit. In the case of the maximum aperture opening, shooting starts immediately, but in the case of shooting with a diaphragm aperture smaller than the opening 27a, a predetermined pulse signal is given to the step motor 32, so that the rotor 32f 6, the drive ring 28 is rotated clockwise from the initial position via the two-stage gear 34. Therefore, the three diaphragm blades 29 are simultaneously rotated clockwise by pushing their engagement pins 29b against the cam groove 28a of the drive ring 28, and stop at a predetermined aperture opening forming position. FIG. 8 shows a state in which the predetermined aperture is set as described above.

  As described above, when a predetermined aperture is set, shooting is started by discharging the charge accumulated in the solid-state image sensor of the imaging device 2 until then, but a predetermined exposure time has elapsed. Then, a positive current is supplied to the coil 33a of the motor 33, and the rotor 33c is rotated counterclockwise in FIG. Therefore, the shutter blades 30 and 31 are rotated in opposite directions by the output pin 33d to close the aperture opening. When the imaging information is transferred to the image storage device in the closed state, a current is supplied to the coil 33a in the opposite direction to the previous one. For this reason, the rotor 33c rotates clockwise, and the shutter blades 30 and 31 are opened by the output pin 33d to return to the state shown in FIG. On the other hand, the coils 32a and 32b of the step motor 32 are also given a pulse signal that rotates the rotor 32f in the opposite direction. Therefore, the rotor 32f rotates the drive ring 28 counterclockwise via the two-stage gear 34 and returns to the initial position shown in FIG. 6 to prepare for the next shooting.

  By the way, if a camera equipped with such a lens barrel is dropped while being carried or dropped from a desktop, a large impact is applied to the components of the lens barrel in the optical axis direction. is there. In particular, when carrying in the state shown in FIGS. 5 and 7, the straight cylinder 17 or the front plate 18 may hit another object. In such a case, a strong force may be applied to the imaging device 2 side with respect to the rectilinear cylinder 17. However, in the case of the present embodiment, the cam groove 14d is formed as a through groove and is configured to be in line contact with the follower pin 17a at a plane of 90 degrees with respect to the optical axis. The cam action does not occur between the contact surface and the follower pin 17a, and the follower pin 17a is not detached from the cam groove 14d. In the present embodiment, only the cam groove 14d that is most easily removed from the follower pin is used as a through groove. However, the other cam grooves 14c, 14e, and 14f are used as through grooves to follower pins 16a, 24a, and 25a. As described above, it is also possible to prevent from falling off.

  In this way, if shooting is no longer continued after shooting, the camera's power switch is turned off, but even in that case, the delay circuit is working and it remains on for a predetermined time. Is continued, and each motor can rotate. Therefore, first, when the motor 4 rotates, the lens frame 8 is moved straight to the imaging device 2 side via the lead screw 6 and stopped in a state where the fourth lens group 7 is brought close to the front surface of the imaging device 2. . On the other hand, a step motor 32 that rotates the drive ring 28 and a motor (not shown) that rotates the rotary cylinder 13 are also rotated. At this time, since the rotor 32f of the step motor 32 is rotated counterclockwise in FIG. 6, the drive ring 28 is also rotated counterclockwise from the initial position via the two-stage gear 34. The diaphragm blades 29 are not rotated for the reasons described above. However, since the pushing portion 28 b pushes the pushed pin 35 b by this rotation, the lens holding member 35 is rotated clockwise against the biasing force of the spring 38, and the third lens group 37. Is moved in a direction crossing the optical axis and retracted to the state shown in FIG.

  When a motor (not shown) arranged outside the lens barrel rotates the gear 12, the integrated rotary cylinder 13 and cam cylinder 14 are guided in the cam groove 10a of the fixed cylinder 10, The key cylinder 15 is not rotated, but is guided to the key groove 10b of the fixed cylinder 10 and is moved straight to the imaging apparatus 2 side while being rotated. Further, the auxiliary cylinder 16, the rectilinear cylinder 17, the first moving member 24, and the second moving member 25 are provided with cam grooves 14c, 14d, 14e, 14f of the cam cylinder 14 and key grooves 15c, 15d, 15e, 15f of the key cylinder 15. Are guided straight to the image pickup apparatus 2 side. In this way, the first to third lens groups 22, 26, and 37 are retracted into the fixed cylinder 10, but in parallel with this, a barrier device (not shown) is also activated, and the barrier plates 20, 21. Covers the opening 18 a on the front surface of the first lens group 22. When a sensor (not shown) detects that the retracted state shown in FIG. 1 has been reached, the rotation of the motor outside the lens barrel (not shown) is stopped.

  Although this embodiment is a lens barrel for a digital camera, when it is used in a camera using a silver salt film, an opening is provided at the position of the imaging device 2 as is well known. It is attached to the camera body so that the opening is arranged on the front surface of the film. In this case, unlike the case of the present embodiment, before shooting, the shutter blades 30 and 31 close the opening 27a and are continuously opened and closed during shooting. Will be. In this embodiment, two shutter blades 30 and 31 are provided. However, the size of the blades may be slightly increased so that only one of them is provided. This is substantially the same in the case of Example 2 described below even though a specific shutter configuration is not shown.

  Further, in this embodiment, a key cylinder 15 is provided, which is an auxiliary cylinder 16, a rectilinear cylinder 17, and a first movement when the integrated rotary cylinder 13 and cam cylinder 14 are rotated. This is to prevent the member 24 and the second moving member 25 from rotating. In particular, since the two motors 32 and 33 are attached to the second moving member, it is not preferable that the second moving member rotates due to the connection of the power source. However, even if the second moving member rotates, the key cylinder 15 is not necessarily required when the rotation angle is small or when a suitable connection method with the power source is taken. In addition, as described above, in this embodiment, zooming is performed using three lens groups. However, the present invention is configured to perform zooming using two lens groups as described in Patent Document 1. Also applies.

  The present embodiment is a collapsible lens barrel in which the first lens group also serves as a focus adjustment lens as described in Patent Document 2, and is configured to be used in a digital camera. Is. The drawings used in the description of the present embodiment mainly show the lead screw mechanism for adjusting the focus in an easy-to-understand manner. FIG. 9 shows the first lens group that is moved during the focus adjustment. FIG. 3 is a cross-sectional view showing a state in which the motor runs away toward one end of the lead screw. 10 is an enlarged cross-sectional view of a part of FIG. 9, and FIG. 11 is a plan view of the straight cylinder shown in FIG. 9 viewed from the imaging device side. FIG. 12 is an enlarged plan view showing a part of FIG. 11. Further, FIG. 13 is a plan view showing a normal state when viewed in the same manner as FIG. 12, and FIG. 14 is a cross-sectional view showing a state in which the first lens group runs away in the other end direction of the lead screw. is there.

  First, the configuration of the present embodiment will be described. The configuration that is substantially the same as that of the first embodiment will be briefly described. The main body member 41 is attached with an imaging device 42 by an appropriate means. The main body member 41 is provided with an operation portion of a lens barrier device, and a flexible printed wiring board connected to a step motor, a shutter device, a sensor, etc., which will be described later, disposed in the lens barrel. Although slits for forming the slits are formed, their illustration is omitted.

  A fixed cylinder 43 is integrally attached to the subject-side surface of the main body member 41. Three cam grooves 43a are formed on the inner peripheral surface of the fixed cylinder 43 as bottomed grooves so that the rotary cylinder 44 can move in the optical axis direction while rotating at angular positions at equal intervals. However, in FIGS. 9 and 14, only one of the cross-sectional shapes is shown. In addition, two key grooves parallel to the optical axis are provided on the inner peripheral surface of the fixed cylinder 43 so that the first key cylinder 45 can move linearly in the direction of the optical axis as the rotary cylinder 44 moves. 43b is formed so as not to interfere with the cam groove 43a, but only one of them is shown in FIGS. Further, the fixed cylinder 43 is formed with two projecting portions 43c and 43d projecting in the radial direction, and a shaft 41a erected on the main body member 41 is inserted into a hole provided in the projecting portions 43c and 43d. Yes. A gear 46 is rotatably attached to the shaft 41 a, and a part of the gear 46 faces the inside of the fixed cylinder 43. The gear 46 is rotated via a reduction gear by a step motor (not shown) attached to the camera body side.

  The rotating cylinder 44 arranged inside the fixed cylinder 43 has a partial gear 44a formed in a predetermined angle range at an end portion on the main body member 41 side. Meshing. In addition, three follower pins 44 b are provided on the outer peripheral surface of the rotating cylinder 44 at equally spaced angular positions, and these are fitted in the cam grooves 43 a provided in the fixed cylinder 43. 9 and 14, only one of the follower pins 44b is shown. Therefore, when the rotating cylinder 44 is rotated via the gear 46 by a step motor (not shown), it is guided in the cam groove 43a and moved in the optical axis direction. Further, three key grooves 44c are formed at equal angular positions on the inner peripheral surface of the rotating cylinder 44, but only one of them is shown in FIGS. It is.

  The first key cylinder 45 disposed inside the rotary cylinder 44 is configured to move linearly in the optical axis direction when the rotary cylinder 44 rotates. That is, a plurality of flexible hook portions 45 a are formed at predetermined angular positions at the subject-side end of the first key cylinder 45, and these are formed on the inner periphery of the rotating cylinder 44. It is fitted in an annular groove. The first key cylinder 45 is formed with two keys 45b on the imaging device 42 side, and these are fitted in the two key grooves 43b of the fixed cylinder 43. In FIG. 14, only one of them is shown. With this configuration, the first key cylinder 45 is guided by the key groove 43b of the fixed cylinder 43 and moved only in the optical axis direction when the rotary cylinder 44 moves in the optical axis direction by the cam groove 43a while being rotated by the gear 46. It will be moved linearly. Further, in the first key cylinder 45, three cam grooves 45c are formed as through grooves at equal angular positions, and two key grooves 45d are formed on the inner peripheral surface. 14 each shows only one of them.

  A second key cylinder 47 is arranged inside the first key cylinder 45, and a third key cylinder 48 is arranged inside the first key cylinder 45 at a predetermined interval. 47 and 48 are integrated by means not shown at the time of assembly. In the second key cylinder 47, three cam grooves 47a are formed as through-grooves at equally spaced angular positions, and two key grooves 47b are formed on the inner peripheral surface. Each shows only one of them. The third key cylinder 48 is formed with two keys 48a, three key grooves 48b penetrating therethrough, and a plurality of hook portions 48c. In FIG. 9 and FIG. One groove 48b and two hook portions 48c are shown. Of these, the key 48 a is fitted in the key groove 45 d of the first key cylinder 45. Therefore, the second key cylinder 47 and the third key cylinder 48 can be moved in the optical axis direction with respect to the first key cylinder 45.

  A cam cylinder 49 and a rectilinear cylinder 50 are arranged between the second key cylinder 47 and the third key cylinder 48. Among them, on the outer peripheral surface of the cam cylinder 49 arranged on the third key cylinder 48 side, three follower pins 49a are provided at equally spaced angular positions. FIG. 9 and FIG. Only one is shown. The follower pin 49 a passes through the cam groove 47 a of the second key cylinder 47 and the cam groove 45 c of the first key cylinder 45, and the tip is fitted in the key groove 44 c of the rotary cylinder 44. Further, the hook portion 48 c of the third key cylinder 48 is engaged with the end surface of the cam cylinder 49 on the subject side. For this reason, the cam cylinder 49 rotates together with the rotary cylinder 44, but moves together with the two key cylinders 47 and 48 in the optical axis direction separately from the rotary cylinder 44. The cam cylinder 49 is formed with three cam grooves 49b as through-grooves at equally spaced angular positions, and three cam grooves 49c are formed as bottomed grooves at equally spaced angular positions on the inner peripheral surface. However, in FIGS. 9 and 14, only one of them is shown.

  Between the second key cylinder 47 and the third key cylinder 48, the rectilinear cylinder 50 disposed on the second key cylinder 47 side has two keys 50a on the outer peripheral surface, and three on the inner peripheral surface. Although one follower pin 50b is provided, one is shown in each of FIGS. 9 and 14, and the illustration is omitted in FIG. The key 50 a is fitted in the key groove 47 b of the second key cylinder 47, and the follower pin 50 b is fitted in the cam groove 49 b of the cam cylinder 49. Therefore, when the cam cylinder 49 rotates, the linear cylinder 50 is guided in the key groove 47b of the second key cylinder 47 and moves linearly in the optical axis direction. Further, the straight cylinder 50 has a wall portion 50c formed with an opening for a photographing optical path on the subject side, and various members are attached thereto. The configuration will be described later. Three follower pins 51a provided at equal intervals on the outer peripheral surface of the moving member 51 are fitted in the three cam grooves 49c of the cam cylinder 49 described above, and these follower pins 51a are connected to the third key. Since the cam groove 49c is fitted through the key groove 48b of the cylinder 48, when the cam cylinder 49 rotates, the moving member 51 is guided by the key groove 48b and linearly moves only in the optical axis direction. It is like that.

  A shutter device and a second lens group are attached to the moving member 51. First, an outline of a shutter device not shown is described. Driving means such as a motor that reciprocally rotates the shutter blades and the diaphragm blades is attached to the surface of the moving member 51 on the subject side. Further, a cover plate 52 is attached to the moving member 51 on the imaging device 42 side at a predetermined interval, and shutter blades and diaphragm blades (not shown) are arranged therebetween. Therefore, it can be said that the moving member 51 is a shutter base plate from the viewpoint of a shutter device. However, the shutter device may be configured as a unit and the unit may be attached to the moving member 51 without being configured in this way. Next, the second lens group 53 is attached to the lens frame 54, and the lens frame 54 is attached to the moving member 51. The moving member 51 is provided with a hole 51b for inserting a flexible printed wiring board (not shown) connected to a step motor described later. A hole for inserting a flexible printed wiring board connected to the driving means and a flexible printed wiring board connected to a sensor described later is also formed.

  Next, the members assembled in the straight cylinder 50 will be described in order. First, a front plate 55 having an opening for a photographing optical path is attached to the subject side of the wall portion 50c with a predetermined interval, and the figure is provided between the wall portion 50c and the front plate 55. A barrier plate not shown is arranged. Further, a motor mounting plate 56 is attached to the wall 50c on the imaging device 42 side by means not shown, and a step is provided on the imaging device 42 side of the motor mounting plate 56. A motor 57 is attached, and a support plate 58 is attached to the stepping motor 57 on the imaging device 42 side. A flexible printed wiring board (not shown) connected to the step motor 57 is inserted into the hole 51b formed in the moving member 51 and a slit (not shown) provided in the main body member 41, and the camera Connected to the power supply in the body. Further, a gear 59 attached to the output shaft of the step motor 57 is disposed between the wall 50c and the motor attachment plate 56.

As shown in an enlarged view in FIG. 10, the metal lead screw 60 has a male screw portion 60 a, and a shaft portion 60 b at one end is formed in a hole formed in the wall portion 50 c of the straight cylinder 50. The shaft 60c at the other end is fitted into a hole formed in the support plate 58 so as to be rotatable. A gear 61 is mounted between the male screw portion 60a and the shaft portion 60b. The gear 61 is disposed between the wall portion 50c and the motor mounting plate 56, and the motor mounting plate 56 is connected to the gear 60. by the arc suppressing 61, the shaft portion 60b of the lead screw 60 is prevented escape from the pores of the wall portion 50c. Further, a contact member 62 is attached between the male screw portion 60a and the shaft portion 60c. As shown in FIG. 12, the contact member 62 has a radial direction of the lead screw 60. An abutting portion 62a that protrudes to is provided. The lead screw 60 is rotated by the gear 59 via a gear 63 that is rotatably attached to a shaft 50d provided on the wall 50c.

  As shown in FIG. 11, the lens frame 65 to which the first lens group 64 is attached has individual holes formed on the two guide pins 66 and 67 attached to the wall portion 50 c of the rectilinear cylinder 50. It is fitted. As shown in FIG. 14, a spring 68 is loosely fitted to one guide pin 66, and the lens frame 65 is urged toward the image pickup device 42 to serve two functions. ing. The first role is a backlashing role for stabilizing the screwing relationship between the male threaded portion 60a of the lead screw 60 and the female threaded portion of the nut member 69 described later, and the second role is the lens frame 65. Even if the female screw part runs away and the screwing of the male screw part 60a of the lead screw 60 is disengaged, the lead screw 60 is reversely rotated to enable screwing again. It will be understood in the description of operation described later. Further, as shown in FIG. 9, the other guide pin 67 has a screw hole formed in the front end surface, and a screw 70 is screwed into the screw pin 70 to prevent the lens frame 65 from coming off. is doing.

  The attachment portion 65a of the lens frame 65 to which the first lens group 64 is attached is configured to be able to slide in the optical axis direction within the cylinder member 71 attached to the wall portion 50c of the rectilinear cylinder 50. As is well known, a synthetic resin nut member 69 is attached to the lens frame 65 so as to be detachable but cannot be rotated, and the female screw portion is connected to the male screw portion 60 a of the lead screw 60. Screwed together. Accordingly, the lens frame 65 can be moved in the optical axis direction when the lead screw 60 rotates. Further, the lens frame 65 is provided with a cam portion 65b having a slope formed so as to protrude toward the support plate 58 side, that is, the imaging device 42 side, in the vicinity of the attaching portion of the nut member 69.

  The lens frame 65 is formed with a plate-shaped light shielding portion 65 c in the vicinity of the fitting position with the guide pin 66. On the other hand, a sensor 72 is attached to the wall portion 50c of the rectilinear cylinder 50 at the tip of a base portion formed toward the imaging device 42 side. The sensor 72 is a so-called photo interrupter having a light emitting part on one side and a light receiving part on the other side with a slit in between, and the light shielding part 65c of the lens frame 65 enters the slit. The light from the light emitting unit that has entered the light receiving unit is blocked. A flexible printed wiring board (not shown) connected to the sensor 72 is inserted into a hole (not shown) formed in the moving member 51 and a slit (not shown) provided in the main body member 41. Connected to the power supply in the camera body.

  A shaft member 73 is attached to the support plate 58, and a plate-like stop member 74 is rotatably attached thereto. The stop member 74 is attached to the subject side of the support plate 58, and as shown in FIG. 12, has a long hole 74a, a bent portion 74b, and a cam follower portion 74c, and the long hole 74a. Is fitted to the shaft portion 60c of the lead screw 60 so that the bent portion 74b can be brought into the operating locus of the abutting portion 62a of the abutting member 62, and the cam follower portion 74c is adapted to the cam portion 65b of the lens frame 65. To be able to contact. The stop member 74 is urged by a spring 75 so as to rotate counterclockwise in FIG. 12. The spring 75 is wound around the shaft member 73 and has one end hooked on the support plate 58. The other end is hung on the stop member 74.

  Next, the operation of this embodiment will be described. In this embodiment, in a retractable lens barrel having a zoom function, the first lens group arranged closest to the subject is moved for focus adjustment. When the camera is not in use, the rotary cylinder 44, the three key cylinders 45, 47, and 48, the cam cylinder 49, and the rectilinear cylinder 50 shown in FIG. It is rarely accommodated in the fixed cylinder 43 and is in a so-called retracted state. In the retracted state, two barrier plates (not shown) disposed between the wall portion 50 c of the rectilinear cylinder 50 and the front plate 55 cover the front surface of the first lens group 64.

  When the camera is turned on in such a retracted state, a step motor (not shown) rotates to rotate the gear 46. Therefore, the rotating cylinder 44 is also moved to the subject side while rotating with the cam cylinder 49, but the first key cylinder 45, the second key cylinder 47, the third key cylinder 48, the moving member 51, and the rectilinear cylinder 50. Is moved straight to the subject side without rotating, and the first lens group 64 and the second lens group 53 are extended. At this time, the rotary cylinder 44, the three key cylinders 45, 47, and 48, and the cam cylinder 49 move toward the subject side at the same speed, but the moving member 51 and the rectilinear cylinder 50 are faster than them and further advance straight. The cylinder 50 moves faster than the moving member 51. Further, in the process of this extension operation, the two barrier plates perform an opening operation and retreat from the front surface of the first lens group 64.

  In this way, the state in which the feeding operation is finished is the initial state (shooting standby state) shown in FIG. 9, and in this embodiment, in this initial state, the shooting lens (first lens group) 64, the second lens group 53) is ready for photographing at the wide-angle end. However, FIGS. 9 to 12 show a state in which the lens frame 65 to which the first lens group 64 for focus adjustment is attached runs away in the one end direction of the lead screw 60, that is, toward the imaging device 42 side. In the normal state, the initial position of the lens frame 65 is slightly left (subject side) from the position shown in FIG. Therefore, in the following, first, the case where the lens frame 65 operates normally will be described, and then the case where the abnormal operation is performed will be described.

  If the photographer does not wish to take pictures in this state after entering the initial state (shooting standby state) as described above, look into a zoom finder (not shown) that is operated in conjunction with the taking lens. However, the relative position relationship between the first lens group 64 and the second lens group 53 is changed by moving the rectilinear cylinder 50 and the moving member 51 simultaneously in the optical axis direction by rotating a step motor (not shown) forward and backward. Change the angle of view and select the desired angle of view. Then, after the desired angle of view is determined, when the release button is pressed, first, the focus adjustment is automatically performed, and then the imaging device 42 performs imaging.

  First, focus adjustment will be described. In order to adjust the focus, by rotating the step motor 57, only the lens frame 65 is moved from the initial position, and the relative position between the first lens group 64 and the second lens group 53 is changed. That is, when the step motor 57 rotates, the rotation is transmitted from the gear 59 to the gear 61 via the gear 63 and the lead screw 60 is rotated. Therefore, the lens frame 65 to which the nut member 69 is attached is connected to the lead screw 60. It is moved along the optical axis in a direction corresponding to the rotational direction of 60 and stopped at the in-focus position.

  In this way, when the focus adjustment is completed, photographing by the imaging device 42 is performed. As is well known, in the case of this type of digital camera, the operation of the shutter blades is performed in one of two sequences. One of them is equipped with an optical viewfinder, and the shutter blade is closed when the exposure opening is in the initial state of the shutter. When shooting, the shutter blade is first fully opened and then shooting is started. It is called a normally closed type. The other is a normally open type in which the shutter blades are in the initial state of the shutter when the exposure opening is fully open, and shooting is started immediately from that state. In the above-described first embodiment, the description has been given of the normally open type, which is relatively widely adopted among them. Therefore, the present embodiment will be described in the case of a normally closed type.

  When the release button is pressed, a shutter blade (not shown) is opened by the driving means to open the exposure opening. For this reason, the solid-state imaging device of the imaging device 42 is exposed to the subject light that has passed through the first lens group 64 and the second lens group 53 from the time when the opening starts, and charges are accumulated. When the shutter blades are fully opened and the operation of the diaphragm blades that are operated as necessary is completed, the charges accumulated in the solid-state image sensor are released so that the charges for photographing are accumulated. Be started. Thereafter, when a predetermined time elapses, the shutter blade is closed by a signal from the exposure time control circuit. As soon as the shutter blades are closed, the imaging information is transferred from the solid-state imaging device to the image storage device. Thereafter, the step motor 57 is rotated to return the lens frame 65 to the initial position, but the rotation is stopped when the light shielding portion 65c of the lens frame 65 blocks the optical path of the sensor 72, and the next shooting standby is performed. It becomes a state.

  By the way, even in the case of the camera equipped with the lens barrel of the present embodiment, if it is dropped while being carried or dropped from a desktop or the like, a large impact in the optical axis direction on the components of the lens barrel. May be added. In particular, when carrying the lens group with the lens group extended from the retracted state, the front plate 55 attached to the rectilinear cylinder 50 may hit another object. In such a case, a strong force is applied to the rectilinear cylinder 50 toward the imaging device 42 side. However, in this embodiment, the cam groove 49b of the cam barrel 49 is formed as a through groove, and is configured to be in line contact with the follower pin 50b at a plane of 90 degrees with respect to the optical axis. The cam action does not occur between the contact surface of the cam groove 49b and the follower pin 50b, and the follower pin 50b is not detached from the cam groove 49b.

  In addition, the front plate 55 attached to the rectilinear cylinder 50 is not hit against other objects or pushed by other objects, and only the lens frame 65 together with the first lens group 64 is located on the imaging device 42 side. It may be pushed hard. When pushed in such a manner, the lens frame 65 may be slightly inclined and may come off from at least one of the guide pins 66 and 67. This is because it is often difficult to lengthen both of the guide pins 66 and 67 in consideration of the accommodation space in the retracted state, and play is provided in the mounting portion of the nut member 69. This is because. In the case of the present embodiment, as can be seen from FIG. 11, the guide pin 67 is located farther from the lead screw 60 than the guide pin 66. Moreover, as can be seen by comparing FIG. 9 and FIG. 14, the guide pin 67 is shorter than the guide pin 66. Therefore, in the case of the present embodiment, the lens frame 65 is easily detached from the guide pin 67. However, in the case of the present embodiment, since the screw 70 is screwed to the tip of the guide pin 67 to prevent it from coming off, there is no possibility that it will come off.

  In this way, when shooting is repeated and there is no longer any intention to shoot, the camera power switch is turned off, but even in such a case, the delay circuit is working and only for a predetermined time. The ON state continues, and a step motor (not shown) can be rotated. Therefore, when the power switch is turned off, the gear 46 is rotated by the rotation of the step motor, the rotating cylinder 44 and the cam cylinder 49 are moved to the imaging device 42 side while rotating, and the other cylinder members 45, 47, 48 and 50 are moved straight to the imaging device 42 side, and a barrier plate (not shown) is closed. Then, the rotation of the step motor stops when a sensor (not shown) detects the retracted position of the rotating cylinder 44.

  Next, a case will be described in which the lens frame 65 runs away from the normal operating range during focus adjustment. As described above, FIGS. 9 to 12 show states when the lens frame 65 runs away to the imaging device 42 side. Therefore, in the initial state where the lens frame 65 is extended from the retracted state, the initial position of the lens frame 65 is a position slightly to the left of the position shown in FIG. 10, and the cam portion 65b is the cam follower portion of the stop member 74. No contact with 74c. In the normal initial state, FIG. 13 is a plan view seen from the right side of FIG. 10, as in FIG.

  In the state of FIG. 13, the stop member 74 is rotated counterclockwise by the biasing force of the spring 75, and the left end edge of the long hole 74 a abuts on the shaft portion 60 c of the lead screw 60. It has been stopped. At this time, the bent portion 74 b of the stop member 74 is retracted out of the operating locus of the contact portion 62 a of the contact member 62. When focus adjustment is performed, the lens frame 65 is moved from the initial position to the subject side by the rotation of the lead screw 60, but the cam portion 65 b is merely moved away from the stop member 74. Therefore, the lens frame 65 is moved to the in-focus position without any trouble, and photographing is performed as described above. When the photographing is completed, the lens frame 65 is moved to the imaging device 42 side, and as described above, the sensor 72 is stopped at the initial position by detecting the light shielding portion 65c. Therefore, the state is the same as the state of FIG.

  However, when the lens frame 65 returns from the in-focus position to the initial position as described above, the lens frame 65 may run out of control (overrun) without stopping at the initial position. The cause is mainly due to poor connection of the connector at the time of assembly adjustment. For example, the mounting position of the sensor 72 may be shifted.

  In this embodiment, when such a runaway occurs, in FIG. 13, the cam portion 65 b of the lens frame 65 pushes the cam follower portion 74 c of the stop member 74, so that the stop member 74 resists the biasing force of the spring 75. Then, by rotating clockwise, the right end edge of the long hole 74a of the stop member 74 is brought into contact with the shaft portion 60c of the lead screw 60, whereby the bent portion 74b is moved in the operating locus of the contact portion 62a of the contact member 62. Located within. Immediately thereafter, the contact portion 62a of the contact member 62 that has rotated in the clockwise direction in FIG. 13 contacts the bent portion 74b, whereby the rotation of the lead screw 60 is stopped.

  9 to 12 show the stopped state. In this embodiment, the rotation of the lead screw 60 is stopped after the stop member 74 is pushed by the cam portion 65b and starts rotating. Since it is performed within one rotation of the lead screw 60, the lens frame 65 is within the range of one pitch of the male screw portion 60a of the lead screw 60, that is, one of the female screw portions of the nut member 69. This means that it has moved only within the pitch range. Therefore, also from this, it is not necessary to lengthen the length of the lead screw 60.

  Incidentally, as described above, the runaway of the lens frame 65 may occur not only when moving from the in-focus position to the initial position but also when moving from the initial position to the in-focus position. Therefore, even in such a case, if the above-described runaway countermeasure configuration is employed, the configuration is extremely excellent from the viewpoint that the length of the lead screw 60 does not need to be increased. However, in the case of the present embodiment, since it is not necessary to do so, a well-known configuration is adopted as a runaway countermeasure configuration when moving from the initial position to the in-focus position.

  That is, when the lens frame 65 starts to move from the initial position, does not stop at the in-focus position, and runs out of control beyond the predetermined focus adjustment range, the female thread portion of the nut member 69 becomes the lead screw. The 60 male threaded portions 60a are removed. The deviated state is shown in FIG. However, at this time, the lens frame 65 is urged toward the imaging device 42 by the spring 68, and the urging force is maximized. Therefore, in FIG. 14, the left end of the male screw portion 60 a of the lead screw 60 and the right end of the female screw portion of the nut member 69 are kept in contact with each other, and only the lead screw 60 is idle. Therefore, when the predetermined repair is completed and the lead screw 60 is reversed, the female screw portion of the nut member 69 is screwed into the male screw portion 60a of the lead screw 60 with the help of the urging force of the spring 68. The lens frame 65 can be returned to the initial position. In view of the state shown in FIG. 14, the above-described configuration for preventing runaway toward the image pickup device 42 is more advantageous than the configuration for preventing runaway in reducing the length of the lead screw 60. Can be understood.

FIG. 3 is a cross-sectional view in the retracted state (the camera is not used) according to the first embodiment. 2A is a view of the cam cylinder shown in FIG. 1 developed from the inside, and FIG. 2B is a view of the key cylinder shown in FIG. 1 developed from the inside. FIG. FIG. 3 is a plan view showing a member attached to a second moving member as viewed from the imaging apparatus side in the retracted state of FIG. 1. FIG. 4 is a plan view showing an aperture mechanism and a holding member for a third lens group in an easy-to-understand manner in the state of FIG. 3. It is sectional drawing which showed the state from which the 1st-3rd lens group was extended to the wide angle end imaging position from the position of FIG. FIG. 6 is a plan view showing the state of FIG. 5 in the same manner as in FIG. 3. FIG. 6 is a cross-sectional view of Example 1 illustrating a telephoto end photographing position of the first to third lens groups. FIG. 7 is a plan view showing a state in which the aperture blade is operated from the maximum aperture opening control position shown in FIGS. 4 and 6 to a predetermined aperture opening control position. FIG. 10 is a cross-sectional view of Example 2 showing a state where the first lens group for focus adjustment has runaway in the direction of one end of the lead screw. It is sectional drawing which expanded and showed a part of FIG. It is the top view which looked at the inside of the straight cylinder shown by FIG. 9 from the imaging device side. It is the top view which expanded and showed a part of FIG. It is the top view which showed the normal state seeing like FIG. It is sectional drawing of Example 2 which shows the state which the 1st lens group run away to the other end direction of the lead screw.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,41 Main body member 1a, 66, 67 Guide pin 2,42 Imaging device 3,56 Motor mounting plate 4,33 Motor 4a Output shaft 5,36,70 Screw 6,60 Lead screw 7 Fourth lens group 8,23, 54, 65 Lens frame 9, 69 Nut member 10, 43 Fixed cylinder 10a, 14c, 14d, 14e, 14f, 28a, 43a, 45c, 47a, 49b, 49c Cam groove 10b, 15c, 15d, 15e, 15f, 43b, 44c, 45d, 47b, 48b Keyway 11, 25c, 25d, 25e, 41a, 50d Shaft 12, 46, 59, 61, 63 Gear 13, 44 Rotating cylinder 13a, 44a Partial gear 13b, 16a, 17a, 24a, 25a , 44b, 49a, 50b, 51a Follower pin 14, 49 Cam cylinder 14a Projection 14b, 45a, 4 c Hook part 15 Key cylinder 15a Groove 15b, 45b, 48a, 50a Key 16 Auxiliary cylinder 17, 50 Linear cylinder 17b, 17c Escape part 18, 55 Front plate 18a, 25b, 27a Open part 19, 27, 52 Cover plate 20, 21 Barrier plate 22, 64 1st lens group 24 1st moving member 24b, 35a Lens holding part 25 2nd moving member 26, 53 2nd lens group 27b Stopper pin 28 Drive ring 28b Pushing part 28c Tooth part 29 Diaphragm blade 29a Blade shaft 29b Engagement pin 30, 31 Shutter blade 32, 57 Step motor 32a, 32b, 33a Coil 32c, 32d, 33b Yoke 32e Output gear 32f, 33c Rotor 33d Output pin 34 Two-stage gear 35 Lens holding member 35b Pressed Moving pin 35c, 62a Contact part 37 Third lens 38, 68, 75 Spring 43c, 43d Overhanging portion 45 First key cylinder 47 Second key cylinder 48 Third key cylinder 50c Wall portion 51 Moving member 51b Hole 58 Support plate 60a Male thread portion 60b, 60c Shaft portion 62 Contact member 65a Mounting part 65b Cam part 65c Light-shielding part 71 Cylindrical member 72 Sensor 73 Shaft member 74 Stop member 74a Long hole 74b Bending part 74c Cam follower part

Claims (5)

A first cylinder having a plurality of cam grooves of the same shape and fixed to the subject side of the main body member; and a first cylinder disposed inside the first cylinder and rotated by driving means. A second cylinder guided in the cam groove and moved in the optical axis direction to enter and exit from the first cylinder; and a plurality of cam grooves of a plurality of types, each of which is disposed inside the second cylinder. And a third cylinder in which at least one of the plurality of types of cam grooves is formed as a through groove, and the third cylinder holding the first lens group disposed closest to the subject side. Having a plurality of follower pins inserted into a predetermined type of cam groove formed as a through groove, and being guided by the cam groove when the third cylinder is rotated by the rotation of the second cylinder. On the inside of the third cylinder and the fourth cylinder moved in the optical axis direction The when the third barrel predetermined type plurality of the third tubular has a Foroapin inserted into the cam groove of the is rotated in the outer peripheral portion with holding the lens unit is location A collapsible body comprising: at least one moving member that is guided by a cam groove and is moved in the optical axis direction to perform zooming by changing a relative position between the lens groups including the first lens group. Lens barrel for camera. In the first cylinder, the main body member includes a focus adjustment drive unit, and a focus adjustment lens frame that holds a focus adjustment lens group and is moved in the optical axis direction by the drive unit. The moving member disposed on the subject side of the focus adjustment lens frame is rotatably attached to a lens holding member that holds the lens group, and a shutter device is attached to the moving member. The lens group held by the holding member is retracted out of the photographing optical path by the driving unit of the shutter device when the third cylinder is accommodated in the first cylinder, and the diameter of the lens frame for focus adjustment 2. The retractable camera lens barrel according to claim 1, wherein the lens barrel is disposed in a directional position. A fifth cylinder is disposed inside the third cylinder and outside the fourth cylinder, and the fifth cylinder is inserted into a predetermined type of cam groove of the third cylinder on the outer periphery. It has the Foroapin, when the third cylindrical is rotated, is guided to the cam grooves and out of the third cylinder with a smaller stroke than the fourth cylinder is moved in the optical axis direction The retractable camera lens barrel according to claim 1 or 2, characterized in that it is configured as described above. The third cylinder has a plurality of types of key grooves formed linearly in parallel with the optical axis and is arranged inside the third cylinder, and the third cylinder is rotated only in the optical axis direction by the rotation of the third cylinder. And the fourth cylinder, the fifth cylinder, and the moving member are disposed inside the sixth cylinder, and the third cylinder rotates when the third cylinder rotates. It is guided by both the predetermined types of cam grooves formed in the three cylinders and the respective key grooves formed in the sixth cylinder, and is individually moved only in the optical axis direction. A retractable camera lens barrel according to any one of claims 1 to 3.   The fourth cylinder has a focus adjusting drive means, a lead screw screwed into a lens frame holding the first lens group and rotated by the drive means, and when the lead screw rotates, A plurality of guide pins for guiding the lens frame so as to move in the optical axis direction, and at least one of the guide pins is a stopper for preventing the lens frame from coming off at the tip of the moving member. 2. A retractable camera lens barrel according to claim 1, wherein a member is attached.

Images