JP2014098878A - Lens barrel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lens barrel which allows a ring-like unit member, and therefore the entire lens barrel, to be made compact, offers high mechanical strength and a simple structure, is easy to assemble, and features superior internal space efficiency.SOLUTION: A lens barrel includes; a linear guide ring having linear guide grooves extending parallel to an optical axis; a movable ring block which has linear guide keys that engage with the linear guide grooves of the linear guide ring and is linearly guided to move in an optical axis direction with respect to the linear guide ring; and a ring-like unit member which is held by a front end section or rear end section of the movable ring block. The movable ring block and the ring-like unit member both have protruded engagement sections which extend outward in a radial direction and engage with each other to couple the movable ring block and the ring-like unit member and which also engage with the linear guide grooves of the linear guide ring.

Description

  The present invention relates to a lens barrel in which a moving ring block and an annular unit member are coupled, and a combined body of the moving ring block and the annular unit member is linearly guided in the optical axis direction with respect to a linear guide ring.

  As this type of lens barrel, in Patent Document 1, a third group lens unit (moving ring block) and a shutter device (annular unit member) are coupled, and a combined body of the third group lens unit and the shutter device is fixed to a fixed frame ( A linearly guided guide in the direction of the optical axis is described. The bottom surface (end surface) of the shutter device and the third group lens unit are each provided with an engaging portion and an engaging hole, and the third group lens unit and the shutter device are engaged by engaging the engaging portion with the engaging hole. Combined. The fixed frame and the third group lens unit are respectively provided with a straight guide groove and a straight guide key. By engaging the straight guide key with the straight guide groove, the combination of the third group lens unit and the shutter device is fixed to the fixed frame. Is guided straight in the direction of the optical axis.

JP 2009-31532 A

  However, in the lens barrel described in Patent Document 1, since the engaging portion is disposed on the outer diameter side of the bottom surface (end surface) of the shutter device, the arrangement space of the opening portion of the shutter device must be sacrificed to some extent. . For this reason, when it is necessary to increase the diameter of the opening of the shutter device in correspondence with the large-diameter lens, there is no space for disposing the engaging portion on the outer diameter side of the bottom of the shutter device. It must be configured to have a larger diameter than the fixed frame, and the configuration of Patent Document 1 cannot be employed. In other words, in order to employ the configuration of Patent Document 1, it is essential to configure the shutter device itself to have a large diameter so as to sufficiently secure an arrangement space for the opening portion on the inner diameter side and the engagement portion on the outer diameter side. Therefore, the overall size of the lens barrel cannot be avoided.

  The lens barrel described in Patent Document 1 has a mechanism (an engaging portion and an engaging hole) for coupling the third group lens unit and the shutter device, and a combined body of the third group lens unit and the shutter device as a fixed frame. On the other hand, the mechanism (straight guide groove and straight guide key) for linearly guiding in the optical axis direction exists as separate mechanisms, so the strength is low, the structure is complicated, and assembly is difficult. Space efficiency will also deteriorate.

  The present invention has been completed on the basis of the above awareness of the problem, and the diameter of the annular unit member and thus the entire lens barrel can be reduced, the strength is high, the structure is simple, the assembly is easy, and the space efficiency inside the lens barrel is excellent. The objective is to obtain a lens barrel.

  The lens barrel of the present invention has a rectilinear guide ring having a rectilinear guide groove parallel to the optical axis, and a rectilinear guide key that engages with the rectilinear guide groove of the rectilinear guide ring, and light is applied to the rectilinear guide ring. In a lens barrel including a moving ring block that is guided linearly in an axial direction and an annular unit member that is held at one end of the moving ring block, the moving ring block and the annular unit member are It has a projecting engaging part radially outward to engage and couple both, and the projecting engaging part engages with a rectilinear guide groove of the rectilinear guide ring. Yes.

  The projecting engaging portion of the annular unit member includes an engaging projection projecting radially outward of the annular unit member, and the projecting engaging portion of the moving ring block is radially outward of the moving ring block. It is preferable to comprise an engaging piece that protrudes and engages with the engaging protrusion.

  The moving ring block and the annular unit member have substantially the same diameter, and projecting engagement portions are formed by projecting outward in the radial direction, and the linear guide ring includes the moving ring block and the annular unit member. It is preferable to have a fitting cylindrical part that fits, and the linear guide groove is formed in the fitting cylindrical part.

  In the assembled state of the rectilinear guide ring, the moving ring block, and the annular unit member, it is practical to match the circumferential positions of the rectilinear guide groove, the rectilinear guide key, and the protruding engagement portion.

  A plurality of sets of the rectilinear guide groove, the rectilinear guide key, and the projecting engagement portion may be formed in the circumferential direction.

  The annular unit member can be constituted by a shutter unit or a polarizing filter unit.

  According to the lens barrel of the present invention, it is possible to reduce the diameter of the annular unit member, and thus the entire barrel, to obtain a lens barrel having high strength, simple structure, easy assembly, and excellent space efficiency inside the barrel. .

It is sectional drawing in the imaging state (zoom area) of the lens barrel by this invention. It is sectional drawing in the accommodation (collapse) state of the lens-barrel by this invention. It is a disassembled perspective view which shows the state before the assembly | attachment of a rectilinear guide ring, 2 group lens moving ring (moving ring block), and a shutter unit (annular unit member). It is a perspective view which shows the state which couple | bonded the 2 group lens moving ring (moving ring block) and the shutter unit (annular unit member). It is a perspective view showing an assembled state in which a combined body of a second group lens moving ring (moving ring block) and a shutter unit (annular unit member) is linearly guided in the optical axis direction with respect to the linear guide ring. It is the front view which looked at the assembly | attachment body of FIG. 5 from the front.

  1 to 6 show an embodiment of a retractable zoom lens barrel (lens barrel) ZL according to the present invention. As shown in FIGS. 1 and 2, the imaging optical system of the zoom lens barrel ZL includes, in order from the object (subject) side, a first lens group LG1, a shutter S, a second lens group LG2, a third lens group LG3, A low-pass filter 25 and an image sensor 26 are provided. The imaging optical system of the zoom lens barrel ZL has a polarization filter 43 that can be inserted and removed on the optical path in front of the second lens group LG2. In the following description, the optical axis direction means a direction parallel to the optical axis O of the photographing optical system, the front means front in the optical axis direction (subject side), and the rear means rear in the optical axis direction (image). Surface side). In the radial direction centered on the optical axis O, the side closer to the optical axis O is the inner diameter side, and the side farther from the optical axis O is the outer diameter side.

  The zoom lens barrel ZL has a cylindrical housing 22 as a fixing member, and the image sensor holder 21 is fixed to the rear portion of the housing 22. The low-pass filter 25 and the image sensor 26 are unitized and fixed to the rear surface portion of the image sensor holder 21.

  The third lens group LG3 is a focus lens group in the zoom lens barrel ZL and is held by the third group lens frame 51. The third group lens frame 51 is supported so as to be linearly movable in the optical axis direction via a guide shaft (not shown), and can be moved in the front-rear direction by a driving force of an AF motor (not shown). .

  In addition to the support driving means for the third group lens frame 51, a zooming group (cam ring) block that is driven and controlled by a lens barrel drive motor (not shown) is supported inside the housing 22. The variable power group (cam ring) block includes a cam ring 11, a feeding cylinder 12, a straight guide ring 13, and a second group lens block 80.

  The cam ring 11 constitutes an external appearance cylinder of the zoom lens barrel ZL together with the feeding cylinder 12, and a guide protrusion (not shown) that is slidably fitted into a cam ring guide groove 22 a formed on the inner peripheral surface of the housing 22. Z). The cam ring 11 is rotated by receiving a rotational driving force from a lens barrel drive motor (not shown), and moves in the optical axis direction while rotating by the guide of the cam ring guide groove 22a. The rectilinear guide ring 13 is supported in the housing 22. The rectilinear guide ring 13 is guided through a rectilinear guide groove formed on the inner surface of the housing 22 so as to be able to move linearly in the optical axis direction. The rectilinear guide ring 13 can rotate relative to the cam ring 11 and moves together in the optical axis direction. Is bound to.

  The second group lens block 80 includes a second group lens moving ring (moving ring block) 8, a polarizing filter unit 40 and a shutter unit (annular unit member) 81 supported on the front part thereof. The polarizing filter unit 40 can insert and remove the polarizing filter 43 on the optical path passing through the optical axis O, and rotate the inserted polarizing filter 43 around the optical axis O by the rotational driving force of the filter driving motor 180. is there. The polarizing filter unit 40 has an engaging portion (not shown), and the shutter unit 81 has an engaging portion 81b (FIGS. 3 and 4). By engaging these engaging portions with each other, the polarizing filter unit 40 (polarizing filter 43) is supported by the shutter unit 81, and both are integrated. The shutter unit 81 has a shutter S that can be opened and closed inside, and the shutter S is driven to open and close by a shutter actuator 82. The second lens group LG2 is held by a holding frame portion 8c formed in the cylindrical portion 8a of the second group lens moving ring 8.

  As shown in FIGS. 3 to 6, the second group lens moving ring 8 has three rectilinear guide keys 8b projecting in the outer diameter direction from the vicinity of the rear end of the cylindrical portion 8a in the circumferential direction thereof. The linear guide ring 13 has a fitting cylindrical portion 13a into which the cylindrical portion 8a of the second group lens moving ring 8 is fitted, and the circumferential direction of the fitting cylindrical portion 13a is parallel to the optical axis. Three straight guide grooves 13b that are long holes are formed. By aligning the circumferential positions of the three rectilinear guide keys 8b and the three rectilinear guide grooves 13b so as to be slidable, the second group lens moving ring 8 moves straight in the optical axis direction with respect to the rectilinear guide ring 13. Guided.

  A second group cam follower 8d is fixed on each of the three linear guide keys 8b of the second group lens moving ring 8 (FIGS. 3 to 6). The second group cam follower 8d is slidably engaged with a second group control cam groove CG2 formed on the inner peripheral surface of the cam ring 11. Since the second group lens moving ring 8 (second group lens block 80) is guided linearly in the optical axis direction via the straight guide ring 13, when the cam ring 11 rotates, the second group cam follower 8d becomes the second group control cam groove. Under the guidance of CG2, the second group lens moving ring 8 (second group lens block 80) moves along a predetermined locus in the optical axis direction.

  A first lens group LG1 is held in the feeding cylinder 12. The feeding cylinder 12 is slidably engaged with a rectilinear guide groove (not shown) formed in the rectilinear guide ring 13 by a rectilinear guide key (not shown) provided on the inner surface side, so that the optical axis direction You are guided straight ahead. A first group cam follower 12a is provided on the outer peripheral surface near the rear end of the feeding cylinder 12, and the first group cam follower 12a slides on a first group control cam groove CG1 formed on the inner peripheral surface of the cam ring 11. Engagement possible. Since the feeding cylinder 12 is linearly guided in the optical axis direction via the linear guide ring 13, when the cam ring 11 rotates, the first group cam follower 12a receives the guidance of the first group control cam groove CG1, and the feeding cylinder 12 Moves along a predetermined locus in the optical axis direction.

  The zoom lens barrel ZL having the above structure operates as follows. When the lens barrel drive motor (not shown) is driven in the lens barrel feeding direction in the photographing state shown in FIG. 1 (wide end of the zoom range), the cam ring is moved relative to the housing 22 according to the locus of the cam ring guide groove 22a. 11 is fed forward in the optical axis direction. The feeding cylinder 12 that supports the first lens group LG1 and the second group lens block 80 that supports the second lens group LG2 are guided by the cam grooves CG1 and CG2 in accordance with the rotation of the cam ring 11, respectively. Move relative to.

  When the lens barrel drive motor (not shown) is driven in the lens barrel storage direction from the photographing state shown in FIG. 1, the cam ring 11 that receives the guidance of the cam ring guide groove 22a rotates and moves backward in the optical axis direction. Is done. The feeding cylinder 12 and the second group lens block 80 (second group lens moving ring 8) move rearward in the optical axis direction together with the cam ring 11 with a predetermined relative movement along the locus of the cam grooves CG1 and CG2 on the cam ring 11. To do. When the lens barrel storage state shown in FIG. 2 is reached, the driving of the lens barrel drive motor (not shown) in the lens barrel storage direction is stopped. Further, the position of the third group lens frame 51 that holds the third lens group LG3 is also controlled by an AF motor (not shown) so as to be in the retracted position shown in FIG.

  In the present embodiment, a second group lens moving ring (moving ring block) 8 and a shutter unit (annular unit member) 81 are coupled, and a combined body of the second group lens moving ring 8 and the shutter unit 81 is connected to the linear guide ring 13. The present invention is applied to a zoom lens barrel ZL that guides straight in the optical axis direction. The details will be described below with reference to FIGS.

  The second group lens moving ring 8 and the shutter unit 81 are annular members having substantially the same diameter. The shutter unit 81 has three engaging protrusions (protruding engaging portions) 81a that protrude radially outward in the circumferential direction. The second group lens moving ring 8 has three engagement pieces (projection engagement portions) 8e that protrude radially outward in the circumferential direction. The rectilinear guide key 8b and the engaging piece 8e of the second group lens moving ring 8 are formed so that their circumferential positions coincide. When the three engaging projections 81a of the shutter unit 81 and the three engaging pieces 8e of the second group lens moving ring 8 are engaged, the second group lens moving ring 8 and the shutter unit 81 are coupled. In this coupled state, the circumferential position of the rectilinear guide key 8b of the second group lens moving ring 8 and the periphery of the shutter unit 81 and the projecting engagement portion (engagement projection 81a and engaging piece 8e) of the second group lens moving ring 8 are set. The direction position matches.

  When the combined body of the second group lens moving ring 8 and the shutter unit 81 is assembled to the straight guide ring 13, the straight guide key 8b of the second group lens moving ring 8 and the projecting engagement portion of the shutter unit 81 and the second group lens moving ring 8 ( The circumferential position of the engaging projection 81a and the engaging piece 8e) and the circumferential position of the rectilinear guide groove 13b of the rectilinear guide ring 13 are made to coincide with each other in the fitting cylindrical portion 13a of the rectilinear guide ring 13 in the second group. The combined body of the lens moving ring 8 and the shutter unit 81 is fitted. Then, both the rectilinear guide key 8b and the shutter unit 81 of the second group lens moving ring 8 and the projecting engagement portions (engagement projections 81a and engaging pieces 8e) of the second group lens moving ring 8 are simultaneously Engage with the straight guide groove 13b.

  As described above, in this embodiment, the linear guide ring 13 having the linear guide groove 13b parallel to the optical axis and the linear guide key 8b that engages with the linear guide groove 13b of the linear guide ring 13 are provided. 13, a second group lens moving ring 8 (moving ring block) guided straight in the optical axis direction, and a shutter unit 81 (annular unit member) held at one end of the second group lens moving ring 8 ), The second lens group moving ring 8 and the shutter unit 81 are engaged with each other and engaged with each other in the radially outward projecting engaging portion (engaging with the engaging piece 8e). The protrusions 81 a) each have a protrusion engaging portion (the engaging piece 8 e and the engaging protrusion 81 a) engages with the rectilinear guide groove 13 b of the rectilinear guide ring 13.

  According to this configuration, the engagement protrusion 81a of the shutter unit 81 protrudes radially outward and does not sacrifice the space where the opening of the shutter unit 81 can be arranged. Even if the diameter of the opening of the unit 81 is increased, a problem in layout does not occur. In addition, the projecting engagement portion (engagement piece 8e and engagement protrusion 81a) of the second group lens moving ring 8 and the shutter unit 81, along with the straight guide key 8b of the second group lens moving ring 8, is linearly guided by the straight guide ring 13. Since it engages with the groove 13b, the diameter of the entire lens barrel can be reduced. Further, the linear guide groove 13b of the linear guide ring 13 functions to guide the linear guide key 8b of the second group lens moving ring 8, and the projecting engagement portion (engagement piece 8e) of the second group lens movable ring 8 and the shutter unit 81. And the function of releasing the engaging projection 81a), the strength is high, the structure is simple, the assembly is easy, and the space efficiency inside the lens barrel can be improved.

  Here, as a comparative example, the circumference of the rectilinear guide key 8b of the second group lens moving ring 8, and the projecting engaging portion (engaging piece 8e and engaging projection 81a) of the second group lens moving ring 8 and the shutter unit 81 are shown. The groove for guiding the rectilinear guide key 8b of the second group lens moving ring 8 in the circumferential direction of the rectilinear guide ring 13 (fitting cylindrical portion 13a), the second group lens moving ring 8 and the shutter are shifted in phase direction. A case is assumed in which a protruding engagement portion (engagement piece 8e and engagement protrusion 81a) of the unit 81 is separately formed as a groove portion. In this comparative object example, a number of grooves are formed in the circumferential direction of the rectilinear guide ring 13 (fitting cylindrical portion 13a) rather than the lens barrel ZL of the present embodiment. The fitting cylindrical portion 13a) as a result, the strength of the entire lens barrel is lowered, the structure is complicated and the assembly becomes difficult, and the space efficiency inside the barrel is also deteriorated.

  In the above embodiment, the case where the shutter unit 81 (annular unit member) is held at the front end portion of the second group lens moving ring 8 (moving ring block) has been described as an example. It is also possible to hold the shutter unit 81 in the part.

  In the above-described embodiment, the case where the engagement protrusion 81a is formed on the shutter unit 81 and the engagement piece 8e is formed on the second group lens moving ring 8 has been described as the protrusion engagement portion. Conversely, it is also possible to form an engaging protrusion on the second group lens moving ring 8 and to form an engaging piece on the shutter unit 81.

  In the above embodiment, the case where the shutter unit 81 is used as the annular unit member has been described as an example. However, it is also possible to use the polarizing filter unit 40 as the annular unit member.

  In the above embodiment, the rectilinear guide groove 13 b of the rectilinear guide ring 13, the rectilinear guide key 8 b of the second group lens moving ring 8, and the projecting engagement portion (engagement projection 81 a and the shutter unit 81 and the second group lens moving ring 8). The case where three sets of the engagement pieces 8e) are arranged in the circumferential direction has been described as an example. However, the present invention is not limited to this, and it is possible to provide two or more of these sets. Further, these sets may be provided at equal intervals or unequal intervals in the circumferential direction. What is important is that the circumferential positions of these sets match.

ZL Retractable zoom lens barrel (lens barrel)
LG1 First lens group LG2 Second lens group LG3 Third lens group S Shutter CG1 First group control cam groove CG2 Second group control cam groove 8 Second group lens moving ring (moving ring block)
8a Cylindrical part 8b Straight guide key 8c Holding frame part 8d Cam follower 8e for 2 groups Engagement piece (protruding engagement part)
DESCRIPTION OF SYMBOLS 11 Cam ring 12 Feeding cylinder 12a Group 1 cam follower 13 Straight guide ring 13a Fitting cylindrical part 13b Straight guide groove 21 Image sensor holder 22 Housing 22a Cam ring guide groove 25 Low pass filter 26 Image sensor 40 Polarizing filter unit 43 Polarizing filter 51 Third group lens frame 80 Second group lens block 81 Shutter unit (annular unit member)
81a Engagement protrusion (projection engagement part)
81b Engagement part 82 Shutter actuator 180 Filter drive motor

Claims (7)

A rectilinear guide ring having a rectilinear guide groove parallel to the optical axis;
A moving ring block having a rectilinear guide key that engages with a rectilinear guide groove of the rectilinear guide ring, and being guided in a straight line in the optical axis direction with respect to the rectilinear guide ring;
An annular unit member held at either end of the moving ring block;
In a lens barrel comprising:
The movable ring block and the annular unit member each have a radially outwardly engaging engagement portion that engages and couples each other, and the protruding engagement portion is formed by the linear guide ring. Engaging a straight guide groove,
A lens barrel characterized by The lens barrel according to claim 1,
The projecting engaging portion of the annular unit member includes an engaging projection projecting radially outward of the annular unit member, and the projecting engaging portion of the moving ring block is radially outward of the moving ring block. A lens barrel comprising an engaging piece that protrudes and engages with the engaging protrusion. The lens barrel according to claim 1 or 2,
The movable ring block and the annular unit member have substantially the same diameter, and the protruding engagement portions are formed to protrude outward in the radial direction,
The linear guide ring has a fitting cylindrical part in which the movable ring block and the annular unit member are fitted, and the linear guide groove is formed in the fitting cylindrical part. The lens barrel according to any one of claims 1 to 3,
The lens barrel in which the rectilinear guide groove, the rectilinear guide key, and the projecting engagement portion are aligned in the circumferential direction in the assembled state of the rectilinear guide ring, the movable ring block, and the annular unit member. The lens barrel according to claim 4, wherein
The lens barrel in which a plurality of sets of the rectilinear guide groove, the rectilinear guide key, and the protrusion engaging portion are formed in the circumferential direction. The lens barrel according to any one of claims 1 to 5,
The annular unit member is a lens barrel made of a shutter unit. The lens barrel according to any one of claims 1 to 5,
The annular unit member is a lens barrel made of a polarizing filter unit.

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