JP5013719B2 - LENS DEVICE AND IMAGING DEVICE - Google Patents

Description

  The present invention relates to a lens device having a telescopic structure by a cam and an imaging device including the same.

  Some lens devices of this type have a fixed cylinder and a moving cam ring that is driven in the optical axis direction by a cam portion formed on the inner periphery of the fixed cylinder. In such a lens apparatus, even when an external force is applied from the front in the optical axis direction (object side), measures are often taken so that the engagement between the fixed cylinder and the movable cam ring is not released.

  For example, Patent Document 1 discloses a lens device in which a protrusion is provided on the outer periphery of a movable cam ring and a protrusion that can contact the protrusion of the movable cam ring is provided on the inner periphery of a fixed cylinder. Yes. When an external force such as an impact acts on the moving cam ring from the front, the projections come into contact with each other to absorb the external force, and the moving cam ring is prevented from coming off from the cam portion of the fixed cylinder.

In Patent Document 2, a moving cylinder that moves in the optical axis direction is constituted by a cylinder main body for holding a lens and a support plate that supports a cam follower, and a hinge groove is provided in the vicinity of the cam follower in the support plate. A lens apparatus is disclosed. In this lens device, when an external force is applied to the movable cylinder from the front, the support plate is bent at the hinge groove portion by the force by which the cam follower is tilted to make it difficult for the cam follower to come off the cam.
JP 2001-324663 A (paragraph 0031, FIG. 10, etc.) JP 2004-125971 A (paragraphs 0015 to 0016, FIG. 3 etc.)

  However, in the lens device disclosed in Patent Document 1, the protruding portion of the fixed cylinder is provided further on the object side than the most object side portion of the cam portion in the fixed cylinder. For this reason, in addition to the length in the optical axis direction for forming the cam portion, the fixed tube needs to have the length in the optical axis direction for forming the projection portion. It gets bigger. Further, since the protrusion of the fixed cylinder protrudes from the inner peripheral surface of the fixed cylinder and the protrusion of the movable cam ring protrudes from the outer peripheral surface of the movable cam ring, the outer peripheral surface of the fixed cylinder and the movable cam ring A large gap is formed between the surface and the outer diameter of the lens device.

  Furthermore, Patent Document 2 has a problem that if the impact force is large, the hinge groove portion of the support plate exceeds the bending limit, and the hinge groove portion is easily damaged.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a lens device capable of avoiding disengagement of the cam engagement when receiving an external force without causing an increase in size or strength, and an imaging device including the lens device. One of them.

A lens device according to an aspect of the present invention is engaged with a cam portion and a first tube having a first contact surface facing an object side in a region closer to the image side than the cam portion, and the cam portion. A lens in which a cam follower and a second cylinder having a second abutting surface that can abut against the first abutting surface from the object side move relatively in the optical axis direction by relative rotation around the optical axis. In the apparatus, the second contact surface includes a plurality of surfaces having different positions in the optical axis direction according to relative rotation positions of the first tube and the second tube, The clearance between the first surface having the optical axis direction position in the first position and the first contact surface is at the second position different from the first surface in the optical axis direction position. It is different from the clearance between the surface and the first contact surface .

  Note that an imaging device including the lens device also constitutes another aspect of the present invention.

  According to the present invention, the cam follower provided in the second cylinder member is detached from the cam part provided in the first cylinder member when receiving an external force without causing an increase in size or strength. It can be surely prevented.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 15 shows the appearance of a digital still camera as an image pickup apparatus including the lens barrel (lens apparatus) that is Embodiment 1 of the present invention.

  In FIG. 15, reference numeral 100 denotes a camera, and 101 denotes a camera body. Reference numeral 102 denotes a main switch of the camera, which is a switch for switching power on and off. Reference numeral 103 denotes a photographing switch, which is a switch that performs photographing preparation operations such as photometry and distance measurement (AF) by a half-press operation, and performs image photographing and recording by a full-press operation.

  Reference numeral 104 denotes a flash light emitting unit, 105 denotes a finder objective window, and 106 denotes a photometric light receiving window. Reference numeral 110 denotes a three-stage retractable lens barrel. The lens barrel 110 is retracted into the camera body 101 when the main switch 102 is in an off state, and protrudes from the camera body 101 when the main switch 102 is turned on to be in a wide state.

  Reference numeral 107 denotes a zoom lever. By rotating this zoom lever, the lens barrel 110 can be zoomed. The lens barrel 110 performs zooming by moving the positions of a plurality of lenses disposed inside while changing the overall length between the wide end and the tele end.

  Although not shown in FIG. 12, an imaging element such as a CCD sensor or a CMOS sensor that photoelectrically converts a subject image formed by the photographing optical system in the lens barrel 110 is mounted in the camera body 101. .

  Next, a specific configuration of the lens barrel described above will be described with reference to FIGS. 1 to 6, 8, and 10 to 14, the arrow direction is the object side, and the opposite direction is the image side. 7 and 9 are views seen from the image side. The object side means the object side in the camera. The image side means the image sensor side in the camera.

  First, the configuration of the first lens barrel unit that constitutes the most object-side portion of the lens barrel and the lens barrier mounted on the first lens barrel unit will be described with reference to FIGS. 1 and 2. Reference numeral 1 denotes a first lens barrel (second cylinder member), which supports the first lens unit 5 and the lens barrier. The first lens barrel 1 is arranged on the outer periphery of a first cam cylinder 21 (first cylinder member: see FIGS. 4 and 5), which will be described later, and moves in the optical axis direction on the object side with respect to the first cam cylinder 21. To do.

  As shown in FIG. 2, a stepped cam 1a facing the image side is formed at the image side end of the first barrel 1. The stepped cam 1a has a plurality of planar portions (second contact surfaces) whose positions in the optical axis direction change stepwise corresponding to the locus (see FIG. 5) of the cam groove 21a formed in the first cam cylinder 21. ) 1i. In other words, these flat portions 1i are in the optical axis direction of the first lens barrel 1 and the first cam barrel 21 according to the zoom position determined by the rotational position of the first cam barrel 21 with respect to the first lens barrel 1. It is formed at a position corresponding to the positional relationship.

  Among these plane portions 1i, one plane portion corresponding to the zoom position has three cam followers 2 fixed to the first barrel 1 when the first barrel 1 receives an external force from the object side. Before coming out of the cam groove 21 a formed in the one cam cylinder 21, it comes into contact with the object side surface (first contact surface) of the shock absorbing projection 21 e formed in the first cam cylinder 21.

  The most image-side surface among the plurality of flat portions 1 i is formed as a surface protruding from the peripheral wall portion of the first lens barrel 1 toward the image side. Further, the surface other than the most image-side surface among the plurality of flat surface portions 1i is the back of the concave portion 1h formed in the inner peripheral side portion (hereinafter simply referred to as the inner peripheral portion) of the peripheral wall portion of the first barrel 1. It is formed as a side (object side) surface. Further, when the first cam cylinder 21 rotates in a non-photographing area between the retracted position and the wide end in an area adjacent to the stepped cam 1a in the inner circumferential portion of the first lens barrel 1 in the circumferential direction. A recess 1h ′ into which a protrusion 21e provided on the first cam cylinder 21 enters is formed. The plurality of flat portions 1 i are all surfaces formed within the radial thickness of the peripheral wall portion of the first lens barrel 1.

  As shown in FIG. 2, the three cam followers 2 are press-fitted and fixed to the first lens barrel 1 at equal intervals in the circumferential direction so that the tapered portions protrude from the inner peripheral surface of the first lens barrel 1. The tapered portion of the cam follower 2 is engaged with the cam groove 21a of the first cam cylinder 21 with almost no play. Thereby, the first lens barrel 1 is supported by the first cam barrel 21. As the first cam barrel 21 rotates, the first barrel 1 moves in the optical axis direction along the lead of the cam groove 21a in the first cam barrel 21.

  At this time, the opposite side of the cam follower 2 from the tapered portion is a rotation preventing portion 2 a that protrudes from the outer peripheral surface of the first lens barrel 1. Since the rotation preventing portion 2a is engaged with a rectilinear groove 22a of a first rectilinear barrel 22 (see FIG. 4) described later, the first barrel 1 moves in the optical axis direction without rotating.

  A sub-follower 3 is provided closer to the object side than the cam follower 2. Similar to the cam follower 2, the three sub followers 3 are arranged at equal intervals in the circumferential direction so that the tapered portions protrude from the inner peripheral surface of the first lens barrel 1, and are fixed to the first lens barrel 1 by press-fitting. . The tapered portion of the sub-follower 3 is engaged with the cam groove 21b of the first cam cylinder 21 with a predetermined play. Thus, when the first lens barrel 1 receives an external force from the object side, the cam follower 2 is pressed against the cam groove 21a of the first cam cylinder 21 so that the cam groove 21a is not damaged.

  The first lens unit 5 is a lens unit disposed on the most object side in the photographing optical system, and is housed and bonded in a first lens housing chamber 1c in which an opening 1b in the first lens barrel 1 is formed. Yes. The first lens unit 5 moves integrally with the first lens barrel 1 in the optical axis direction.

  A barrier driving member 6 is rotatably attached to the image side portion of the inner peripheral portion of the first barrel 1 by bayonet coupling. The barrier driving member 6 also moves integrally with the first lens barrel 1 in the optical axis direction. When the lens barrel is retracted from the wide end position toward the retracted position, two protrusions 6a formed on the barrier driving member 6 so as to extend toward the image side are driving end faces 21g of the first cam cylinder 21. And follow the rotation of the first cam cylinder 21 and rotate integrally therewith. Due to the rotation of the barrier driving member 6, the barrier blades 9 and 10 disposed at positions facing the barrier driving member 6 enter the opening 13 a of the barrier cover 13 and cover the front surface of the first lens unit 5. The barrier is closed. The barrier blades 9 and 10 are rotatably supported by support shafts 1f and 1g formed on the object-side surface of the first lens barrel 1, respectively.

  One ends of open springs 7 and 8 are hung on the fixed shafts 1d and 1e formed on the first lens barrel 1, respectively. The other ends of these open springs 7 and 8 are respectively hooked on fixed shafts 6b and 6c formed on the barrier drive member 6. The opening springs 7 and 8 urge the barrier driving member 6 and the barrier blades 9 and 10 in the opening direction. During the barrier closing operation, the opening springs 7 and 8 are charged.

  Further, when the lens barrel projects from the retracted position to the wide end position, the protrusion 6a of the barrier driving member 6 that is in contact with the driving end surface 21g of the first cam cylinder 21 becomes free, and the barrier driving member 6 It is rotated by the biasing force of the open springs 7 and 8 that have been charged. By this rotation, the barrier blades 9 and 10 perform a barrier opening operation that rotates so as to retreat out of the opening 13 a of the barrier cover 13.

  Reference numeral 13 denotes a barrier cover, and an opening 13a is formed at the center thereof. The barrier cover 13 supports the barrier blades 9 and 10 from the object side with respect to the first lens barrel 1. The barrier cover 13 is fixed to the first lens barrel 1 by bayonet coupling.

  Reference numeral 14 denotes a cap, which is fixed to the barrier cover 13 by adhesion.

  Reference numerals 11 and 12 denote closing springs, one end of which is hooked on hooks 6d and 6e formed on the barrier driving member 6, and the other end is hooked on hooks 9a and 10a formed on the barrier blades 9 and 10, respectively. The closing springs 11 and 12 urge the barrier blades 9 and 10 in the closing direction.

  Next, a support structure of the exposure mechanism 16 as the second lens barrel unit will be described with reference to FIG. The second lens unit 15 is a lens unit disposed on the image side of the first lens unit 16 and is supported by the exposure mechanism 16. For this reason, the second lens unit 15 moves in the optical axis direction integrally with the exposure mechanism 16.

  On the outer periphery of the exposure mechanism 16, two cam followers 16 a having a tapered portion and a moving cam follower 17 in which the tapered portion is urged toward the outer side in the lens barrel radial direction by a compression spring 18 are provided at equal intervals in the circumferential direction. ing. These cam followers 16a and 17 pass through three rectilinear grooves 19a formed in a second rectilinear cylinder 19 described later and engage with three cam grooves 20a formed in a second cam cylinder 20 described later. . Thereby, the exposure mechanism 16 is supported by the second cam cylinder. When the second cam cylinder 20 rotates around the optical axis, the exposure mechanism 16 moves in the optical axis direction along the lead of the cam groove 20a. At this time, the cam follower 16a and the moving cam follower 17 of the exposure mechanism 16 are prevented from rotating by the rectilinear groove 19a formed in the second rectilinear cylinder 19, and thus move in the optical axis direction without rotating.

  Three cam followers 19d having tapered portions are press-fitted and fixed at equal intervals in the circumferential direction at the outer peripheral portion at the image side end of the second rectilinear cylinder 19. The cam followers 19 d engage with the cam grooves 21 c of the first cam cylinder 21, so that the second rectilinear cylinder 19 is supported by the first cam cylinder 21. When the first cam cylinder 21 rotates, the second rectilinear cylinder 19 moves in the optical axis direction along the lead of the cam groove 21c of the first cam cylinder 21.

  At this time, since the two rectilinear grooves 19e formed in the second rectilinear cylinder 19 are engaged with rectilinear keys 28a formed in a rectilinear plate 28 (see FIG. 13) described later, the second rectilinear cylinder 19 is In the state where the rotation around the optical axis is prevented, the optical axis moves.

  The second cam cylinder 20 is sandwiched between a flange 19b formed on the outer periphery of the second rectilinear cylinder 19 and the three support claws 19c so as to be around the optical axis with respect to the second rectilinear cylinder 19. It is rotatably supported. Three drive keys 20 b formed on the outer periphery of the second cam cylinder 20 engage with a rectilinear groove 21 d formed on the first cam cylinder 21. Thereby, rotation of the 1st cam cylinder 21 is transmitted to the 2nd cam cylinder 20, and these rotate integrally.

  Next, a support structure for the first lens barrel unit and the second lens barrel unit will be described with reference to FIGS. FIGS. 12A, 12B, and 12C show cross sections of the first barrel 1 and the first cam barrel 21 in the retracted state, the wide end position, and the tele end position, respectively.

  The first cam barrel 21 supports the first lens barrel 1 that holds the first lens unit 5 and the exposure mechanism 16 that holds the second lens unit 15, and the rotational force of the first cam barrel 21 is applied to the second cam barrel. 20. The first cam cylinder 21 is incorporated in the first rectilinear cylinder 22 as follows.

  First, as shown in FIGS. 6 and 7, the impact absorbing projection 21 e of the first cam cylinder 21 is passed through the notch 22 c formed in the flange portion 22 b of the first rectilinear cylinder 22. Then, the first cam cylinder 21 is slightly rotated. Next, as shown in FIGS. 8 and 10, the support protrusion 21 f of the first cam cylinder 21 is passed through the notch 22 c of the first rectilinear cylinder 22. Then, the support protrusion 21 f of the first cam cylinder 21 is brought into contact with the flange 22 b of the first rectilinear cylinder 22. Thus, the first cam cylinder 21 is rotatably incorporated inside the first rectilinear cylinder 22 and moves in the optical axis direction integrally with the first rectilinear cylinder 22.

  On the outer peripheral surface of the first cam cylinder 21, a drive key 21h formed on the image side with respect to the support protrusion 21f engages with a rectilinear groove 25a of the rotary cylinder 25 described later. As a result, the rotation of the rotating cylinder 25 is transmitted to the first cam cylinder 21 and rotates around the optical axis integrally with the rotating cylinder 25.

  The first cam barrel 21 supports the first lens barrel 1 and the exposure mechanism 16 and transmits the rotational force of the first cam barrel 21 to the second cam barrel 20. On the outer peripheral surface of the first cam cylinder 21, as shown in FIG. 6, there are three cam grooves 21a in which the imaging region from the wide position to the tele position is a non-linear cam and the non-imaging region is a linear cam. Is formed. Further, on the outer peripheral surface, a cam groove 21b having the same cam locus as the cam groove 21a is formed on the object side of the cam groove 21a. As described above, the cam follower 2 is engaged with the cam groove 21a with almost no backlash, and the sub follower 3 is engaged with the cam groove 21b with a predetermined backlash.

  Further, shock absorbing projections 21e are provided at a phase different from that of the support projections 21f in a region closer to the image side than the shooting region of the cam groove 21a on the outer peripheral surface of the first cam cylinder 21 (shown by hatching in FIG. 5). . As described above, when the first lens barrel 1 receives external force from the object side, the first lens barrel before the cam follower 2 fixed to the first lens barrel 1 is disengaged from the cam groove 21a of the first cam barrel 21. One flat surface portion 1i abuts on the object-side surface of the shock absorbing projection 21e.

  The shock absorbing protrusion 21e prevents the cam engagement from being disengaged at a zoom position (in this embodiment, the wide end) where the cam follower 2 is disengaged from the cam groove 21a when the first lens barrel 1 receives an external force. It is provided at a position where it is most effectively prevented. Specifically, as shown in FIGS. 11 and 12B, when the first lens barrel 1 is rotated to the wide end position where the lens barrel extends the longest, the impact absorbing projection 21e and the sub follower 3 The position is set so that the cam follower 2 is disposed therebetween. In other words, at the wide end position, the sub follower 3, the cam follower 2, and the shock absorbing projection 21e are arranged in the optical axis direction.

  As for the position in the optical axis direction, the shock absorbing projection 21e protrudes from the concave portion 1h of the first lens barrel 1 to the image side at the wide end position. Then, a slight clearance L1 is provided on the image side end surface of the portion of the first lens barrel 1 that holds the cam follower 2 and the sub follower 3 (the image side surface of the flat surface portion 1i, hereinafter referred to as the first flat surface portion). An impact absorbing projection 21e is disposed at the opposing position.

  In this state, when an external force acts on the first lens barrel 1 from the object side, the first flat surface portion 1i of the first lens barrel 1 comes into contact with the object-side end surface of the shock absorbing projection 21e from the object side. In other zoom positions and non-photographing areas, as shown in FIGS. 12C and 12A, the shock absorbing projections 21e are inward of the recesses 1h and 1h ′ formed on the inner periphery of the first lens barrel 1. Therefore, the increase in the outer diameter of the first lens barrel 1 due to the provision of the shock absorbing protrusion 21e is avoided.

  As can be seen from a comparison between FIGS. 12B and 12C, the clearance L1 between the shock absorbing projection 21e and the flat portion 1i of the first lens barrel 1 is larger at the wide end position than at the other zoom positions. It is set small. This prevents the cam from being disengaged due to a reliable external force at the wide end position, and also prevents interference between the flat surface portion 1i and the shock absorbing projection 21e during zooming between zoom positions other than the wide end position. Zoom operation is performed. In the retracted state shown in FIG. 12A, since the entire lens barrel is accommodated in the camera body, the strength against external force is not as high as that at the time of photographing. For this reason, the clearance L1 between the innermost surface of the recess 1h ′ and the shock absorbing projection 21e is larger than the clearance L1 at each zoom position.

  A hooking amount (contact amount) L2 between the shock absorbing projection 21e and the flat surface portion 1i of the first barrel 1 in the lens barrel radial direction is the same as a hooking amount L3 between the cam follower 2 and the cam groove 21a of the first cam barrel 21. Or larger. Thus, when the first lens barrel 1 receives an external force, more than half of the external force is borne by the contact between the impact absorbing projection 21e and the flat surface portion 1i, and the cam follower 2 and the cam groove 21a of the first cam barrel 21 are loaded. The external force that acts on and is reduced.

  A cam groove 21c and a rectilinear groove 21d are formed in the inner peripheral portion of the first cam cylinder 21. The exposure mechanism 16 is stably supported by engaging the cam follower 19d of the second rectilinear cylinder 19 with almost no play in the cam groove 21c. Further, the drive key 20b of the second cam cylinder 20 is engaged with the rectilinear groove 21d, whereby the second cam cylinder 20 and the first cam cylinder 21 can rotate integrally.

  The first rectilinear cylinder 22 supports the first cam cylinder 21 so as to be rotatable around the optical axis, and prevents the first lens barrel 1 from rotating and performs a rectilinear guide. Three cam followers 23 are press-fitted and fixed to the first rectilinear cylinder 22 so that the tapered portion protrudes from the outer peripheral surface of the first rectilinear cylinder 22. These cam followers 23 are engaged with cam grooves 25b formed in a rotary cylinder 25 described later. For this reason, when the rotary cylinder 25 rotates, the first rectilinear cylinder 22 moves in the optical axis direction along the lead of the cam groove 25 b formed in the rotary cylinder 25. At this time, a rectilinear key 28b of a rectilinear plate 28 to be described later is inserted into the rotation prevention hole 22d formed in the first rectilinear cylinder 22. For this reason, the first rectilinear cylinder 22 moves in the optical axis direction while being prevented from rotating.

  The cap 24 is bonded to the tip of the first rectilinear cylinder 22 to prevent the first rectilinear cylinder 22 from being deformed.

  A cap ring 27 is fixed to the tip of the rotary cylinder 25. The rotary cylinder 25 is supported by the fixed cylinder 30 so as to be rotatable around the optical axis. Three rectilinear grooves 25 a and three cam grooves 25 b are formed on the inner peripheral surface of the rotary cylinder 25. In addition, three cam followers 26 are press-fitted and fixed to the rotary cylinder 25 so that the tapered portion protrudes from the outer peripheral surface of the rotary cylinder 25. When the cam follower 26 is engaged with a cam groove 30 a formed in the fixed cylinder 30, the rotary cylinder 25 is supported by the fixed cylinder 30.

  A drive shaft 25c is formed on the object side of the rotary cylinder 25 with respect to the cam follower 26. The drive shaft 25 c passes through a cam groove 30 b formed in the fixed cylinder 30 and engages with a rectilinear groove 29 a of a drive cylinder 29 that is rotatably disposed on the outer periphery of the fixed cylinder 30. Due to the engagement between the drive shaft 25 c and the rectilinear groove 29 a, the rotational force of the drive cylinder 29 is transmitted to the rotary cylinder 25. The rotating cylinder 25 to which the rotational force is transmitted moves in the optical axis direction along the lead of the cam groove 30a of the fixed cylinder 30 while rotating.

  The rectilinear plate 28 moves integrally with the rotary cylinder 25 in the optical axis direction. The rectilinear plate 28 is formed with two rectilinear keys 28a and two rectilinear keys 28b extending to the object side. The rectilinear key 28 a is slidably engaged with the rectilinear groove 19 e of the second rectilinear cylinder 19. Thereby, the rotation of the second rectilinear cylinder 19 is prevented. Further, the rectilinear key 28b is inserted into the rotation preventing hole 22d of the first rectilinear cylinder 22 as described above. Thereby, the rotation of the first rectilinear cylinder 22 is prevented.

  In addition, three protrusions 28 d protruding in the radial direction are formed on the outer periphery of the flange portion 28 b of the rectilinear plate 28. The protrusions 28d engage with the rectilinear grooves c formed in the fixed cylinder 30 to prevent the rectilinear plate 28 from rotating.

  The drive cylinder 29 is supported by the outer peripheral surface of the fixed cylinder 30 so as to be rotatable around the optical axis. A gear portion 29b formed on the outer periphery of the drive cylinder 29 meshes with a reduction gear 34 shown in FIG.

  The fixed cylinder 30 is a base member that constitutes the main body of the lens barrel, and is fixed to the support base plate 31 by screws 36 shown in FIG.

  The support base plate 31 is coupled and fixed to the camera chassis. The support base plate 31 supports the fixed cylinder 30, the motor 32, and the reduction gear 34. The motor 32 is fixed to the support base plate 31 by screws 33, and the reduction gear 34 is held by the support base plate 31 and the cover 35.

  The rotational force of the motor 32 is transmitted to the reduction gear 34 via a gear 32 a fixed to the tip of the motor 32, and further transmitted to the drive cylinder 29 via the reduction gear 34. The cover 35 holds the drive cylinder 29, the fixed cylinder 30 and the reduction gear 34 together with the support base plate 31.

  As described above, in the present embodiment, the shock absorbing protrusion 21e is provided in a part of the image side of the cam groove 21a on the outer peripheral surface of the first cam barrel 21, and the first lens barrel 1 has a shock absorbing portion. A plurality of flat portions 1i (stepped cams 1a) that can come into contact with the protrusion 21e from the object side are provided. Thereby, when the first lens barrel 1 receives an external force from the object side, any one of the flat portions 1i of the first lens barrel 1 comes into contact with the impact absorbing protrusion 21e of the first cam barrel 21 to absorb the external force. be able to. Therefore, it is possible to reliably prevent the cam follower 2 fixed to the first lens barrel 1 from being disengaged from the cam groove 21a of the first cam tube 21.

  Further, in a zoom position other than the wide end position where the first lens barrel 1 moves closest to the object side with respect to the first cam barrel 21, and in a non-photographing region, the shock absorbing protrusion 21e of the first cam barrel 21 is the first mirror. It enters into the recesses 1h and 1h 'formed in the inner periphery of the cylinder 1. Furthermore, in the first lens barrel 1, the plurality of flat surface portions 1 i (stepped cams 1 a) are formed within the thickness of the peripheral wall portion of the first lens barrel 1. Therefore, the inner peripheral surface of the first lens barrel 1 can be brought close to the outer peripheral surface of the first cam tube 21, and an increase in the outer diameter of the first lens barrel 1 due to the provision of the shock absorbing protrusion 21e is avoided. it can.

  Furthermore, since the hooking amount L2 between the shock absorbing projection 21e and the flat surface portion 1i of the first barrel 1 is equal to or larger than the hooking amount L3 between the cam follower 2 and the cam groove 21a of the first cam barrel 21, the first barrel 1 Can reduce the burden on the cam follower 2 and the cam groove 21a when receiving external force.

  In addition, the structure demonstrated in the present Example is only an example of embodiment of this invention, and this invention is not necessarily limited to this. That is, the embodiment of the present invention may be anything as long as the content described in the claims is satisfied. For example, in the above-described embodiment, the case where the first cylindrical member rotates with respect to the second cylindrical member has been described. However, in the present invention, the second cylindrical member rotates with respect to the first cylindrical member. It can also be applied to. Moreover, although the said Example demonstrated the case where the 1st cylinder member was arrange | positioned inside the 2nd cylinder member, when the 2nd cylinder member is arrange | positioned inside the 1st cylinder member Also, the present invention can be applied.

1 is an exploded perspective view showing a configuration of a first lens barrel unit of a lens barrel that is an embodiment of the present invention. FIG. The perspective view of the 1st lens-barrel in an Example. The disassembled perspective view which shows the structure of the 2nd lens-barrel unit (exposure mechanism) in an Example. The disassembled perspective view which shows the support structure of the 1st lens barrel unit and 2nd lens barrel unit in an Example. The perspective view which shows the 1st cam cylinder in an Example. FIG. 3 is an exploded perspective view for explaining a method of incorporating the first cam cylinder into the first rectilinear cylinder in the embodiment. The rear view which shows the state in the middle of the assembly | attachment to the 1st rectilinear advance cylinder of the 1st cam cylinder in an Example. FIG. 3 is an exploded perspective view for explaining a method of incorporating the first cam cylinder into the first rectilinear cylinder in the embodiment. The rear view which shows the assembly completion state to the 1st rectilinear advance cylinder of the 1st cam cylinder in an Example. Sectional drawing which shows the state in which the 1st cam cylinder in the Example was supported by the 1st rectilinear advance cylinder. The side view which shows the relationship between the impact-absorbing protrusion of the 1st cam cylinder and the stepped cam of a 1st lens barrel in the wide end position in an Example. FIG. 4 is a cross-sectional view showing the relationship between the impact-absorbing protrusion of the cam barrel and the stepped cam of the first barrel in the embodiment, where (a) is in the retracted state, (b) is in the wide end position, and (c) is in the tele end position. Show. The disassembled perspective view which shows from the fixed cylinder in an Example to the 1st lens-barrel unit. The disassembled perspective view which shows the lens-barrel and drive system in an Example. 1 is an external view of a camera including a lens barrel of an embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 1st lens tube 1a Stepped cam 1h, 1h 'Concave part 1i Plane part 2 Cam follower 3 Sub follower 5 1st lens unit 15 2nd lens unit 21 1st cam cylinder 21a, 21b, 21c Cam groove 21e Shock absorption protrusion 21f Support protrusion 22 First straight cylinder L1 Clearance L2, L3 Engagement amount

Claims (7)

A first cylinder having a cam portion and a first contact surface facing the object side in a region closer to the image side than the cam portion, a cam follower engaged with the cam portion, and the first contact surface A second cylinder having a second contact surface that can be contacted from the object side, and a relative movement in the optical axis direction by relative rotation around the optical axis,
The second contact surface is constituted by a plurality of surfaces having different positions in the optical axis direction according to the relative rotational positions of the first tube and the second tube,
The clearance between the first surface of the plurality of surfaces in the optical axis direction position at the first position and the first contact surface is different from the first surface in the optical axis direction position. clearance between different features and, Relais lens device between the second surface at a position between said first abutment surface. The first contact surface is an object-side end surface of a first protrusion formed so as to protrude in a radial direction on a peripheral wall surface of the first cylinder ,
Said second abutment surface, the lens device according to claim 1, characterized in that said second surface facing the radial thickness image side formed in the peripheral wall of the cylinder. The first cylinder is disposed inside the second cylinder ;
The lens device according to claim 2 , wherein a concave portion for forming a space in which the first protrusion moves is formed in an inner peripheral side portion of the peripheral wall portion of the second cylinder . In the radial direction of the first cylinder and the second cylinder , the amount of contact between the first contact surface and the second contact surface is equal to or greater than the amount of engagement between the cam portion and the cam follower. lens apparatus according to any one of claims 1 to 3, characterized in that. The lens according to any one of claims 1 to 4, wherein a clearance when the second cylinder is in a wide end position is smaller than a clearance when the second cylinder is in a retracted state. apparatus. The clearance when the second cylinder is in the wide end position is smaller than the clearance when the second cylinder is in the tele end position, and the clearance when the second cylinder is in the tele end position is The lens apparatus according to claim 5, wherein the second cylinder is smaller than a clearance in a retracted state.   An imaging apparatus comprising the lens device according to claim 1.