JPWO2020170585A1 - Aperture mechanism and optical equipment - Google Patents

Abstract

It is possible to reduce the number of members, improve assembly accuracy, improve rotational stability of members, improve the efficiency of assembly work, improve optical performance, and realize cost reduction, miniaturization, and thinning. Aperture mechanism and optical equipment are provided. A diaphragm blade having a first member 28 having a cam groove 31, a second member 25 having a hole 25a, a first protrusion 27a engaging with the hole 25a, and a second protrusion 27b engaging with the cam groove 31. 27, a holding member 26 that rotatably holds at least one of the first member 28 or the second member 25, and between the one and the holding member 26, the other of the first member 28 or the second member 25. And the diaphragm blade 27 are arranged.

Description

The present invention relates to a diaphragm mechanism and an optical device including the diaphragm mechanism.

Conventionally, a lens barrel of a digital single-lens reflex camera or the like is provided with an aperture mechanism for changing the open aperture / aperture aperture (see, for example, Patent Document 1).

Lens barrels are required to be smaller, thinner, and have improved optical performance.

Japanese Unexamined Patent Publication No. 04-128727

The throttle mechanism of one aspect of the present disclosure includes a first member having a cam groove, a second member having a hole, a first protrusion that engages with the hole, and a second protrusion that engages with the cam groove. A diaphragm blade having a The other of the diaphragm blades and the diaphragm blades are arranged.

The optical device of one aspect of the present disclosure is configured to include the aperture mechanism of one aspect described above.

It is sectional drawing which shows the camera (imaging apparatus), a lens barrel, and an aperture mechanism which concerns on one Embodiment. It is an enlarged view of the S part of FIG. 1, and is the cross-sectional view which shows the diaphragm mechanism which concerns on one Embodiment. It is an exploded perspective view of the diaphragm mechanism which concerns on one Embodiment. It is a perspective view which shows the diaphragm mechanism which concerns on one Embodiment, and is the figure which shows the Wide state which advanced relative to the 3rd moving cylinder. It is a front view seen from the subject side which shows the diaphragm mechanism which concerns on one Embodiment, and is the figure which shows the state before the cam member is rotatably attached to the holding member by the attachment part. It is a front view seen from the subject side which shows the diaphragm mechanism which concerns on one Embodiment, and is the figure which shows the state in the process of rotatably attaching a cam member to a holding member by an attachment part. It is a front view seen from the subject side which shows the diaphragm mechanism which concerns on one Embodiment, and is the figure which shows the state which the cam member is rotatably attached to the holding member by the attachment part. It is a figure which shows the drawing mechanism which concerns on one Embodiment, and is the figure which shows the 1st spring member and the follower pin (eccentric pin) for drawing. It is a perspective view which shows the diaphragm mechanism which concerns on one Embodiment, and is the figure which shows the Tele state which retracted relative to the 3rd moving cylinder. It is a side view which shows the diaphragm mechanism which concerns on one Embodiment, and is the figure which shows the Wide state which advanced relative to the 3rd moving cylinder. It is a side view which shows the diaphragm mechanism which concerns on one Embodiment, and is the figure which shows the Tele state which retracted relative to the 3rd moving cylinder. It is a figure which shows the follower pin (eccentric pin) and the cam groove for the diaphragm of the diaphragm mechanism which concerns on one Embodiment, and is the figure which shows the Wide state which advanced relative to the 3rd moving cylinder. It is a figure which shows the follower pin (eccentric pin) and the cam groove for the diaphragm of the diaphragm mechanism which concerns on one Embodiment, and is the figure which shows the Tele state which retracted relative to the 3rd moving cylinder. It is a side view which shows the diaphragm mechanism which concerns on one Embodiment, and is the figure which shows the Wide state which advanced relative to the 3rd moving cylinder. It is a side view which shows the diaphragm mechanism which concerns on one Embodiment, and is the figure which shows the Tele state which retracted relative to the 3rd moving cylinder.

Hereinafter, the diaphragm mechanism and the optical device according to the embodiment will be described with reference to FIGS. 1 to 15.

Here, in the present embodiment, it is assumed that the diaphragm mechanism is provided in the lens barrel (optical device) of an imaging device (optical device) such as a digital single-lens reflex camera, but the diaphragm mechanism is interchangeable. It may be provided in a non-interchangeable lens barrel, and may be further provided in another imaging device (optical device) such as a digital still camera or a digital video camera.

As shown in FIG. 1, the camera A, which is the image pickup apparatus of the present embodiment, includes a camera body 100 and a lens barrel 1 that can be attached to and detached from the camera body 100.

The camera body 100 contains, for example, an image pickup element such as a CCD that captures a subject image via the lens barrel 1, an AF circuit for performing a focus operation, a camera CPU that controls the operation of the camera A, and various data. It is equipped with a microprocessor having a memory for storing.

The lens barrel 1 of the present embodiment is provided on the image plane side / imaging side on the rear side of the axial direction O1 along the optical axis direction, and has a substantially annular mount portion 2 for connecting to the camera body 100 and a mount portion. A first fixed cylinder (fixed ring, guide ring) 3 provided coaxially with the rear end connected to 2 and a second fixed cylinder (fixed ring, fixed ring) provided coaxially with the first fixed cylinder 3. The guide ring) 4 and the zoom operation ring 5 which is coaxially arranged on the outer side in the radial direction of the second fixed cylinder 4 and rotatably provided around the axis O1 at a predetermined angle (zoom rotation angle), and the second fixed It is provided with a focus operation ring 6 which is coaxially arranged on the outer side in the radial direction of the cylinder 4 and is rotatably provided around the axis O1 at a predetermined angle (focus rotation angle).

Further, the lens barrel 1 of the present embodiment is coaxially arranged on the outer side of the first fixed cylinder 3 in the radial direction, and has a first cam cylinder 7 that rotates in conjunction with the zoom operation ring 5 and a first fixed cylinder 3. The second cam cylinder 8 is coaxially arranged inside in the radial direction of the above and rotates in conjunction with the zoom operation ring 5, and is coaxially arranged between the second fixed cylinder 4 and the first cam cylinder 7 and has an axis O1. A first moving cylinder 9 provided so as to be able to move forward and backward in the direction, and a second moving cylinder 10 arranged coaxially inside the first cam cylinder 7 in the radial direction and provided so as to be movable forward and backward in the axis O1 direction. A third moving cylinder 11 coaxially arranged inside the second moving cylinder 10 and the first fixed cylinder 3 so as to be movable back and forth in the axis O1 direction, and inside the first fixed cylinder 3 in the radial direction. It is provided with a fourth moving cylinder 12 which is arranged coaxially and is provided so as to be able to move forward and backward in the direction of the axis O1.

Further, the lens barrel 1 of the present embodiment has the first lens group L1, the second lens group L2, the third lens group L3, the fourth lens group L4, and the fifth lens in order from the subject side on the front side in the axis O1 direction. It has six lens groups, a group L5 and a sixth lens group L6.

The first lens group L1 includes a lens and a first lens holding frame (lens chamber) 15 for holding the lens, and a first moving cylinder provided by inserting a follower into a cam groove of the first cam cylinder 7. The first lens holding frame 15 is fixedly arranged in 9.

The second lens group L2 includes a lens and a second lens holding frame (lens chamber) 16 for holding the lens, and a second moving cylinder provided by inserting a follower into a cam groove of the first cam cylinder 7. The second lens holding frame 16 is fixedly arranged on the 10.

The third lens group L3 includes a lens and a third lens holding frame (lens chamber) 17 for holding the lens, and the third moving cylinder 11 supports the third lens holding frame 17 so as to be able to advance and retreat in the axis O1 direction. Is arranged.

The fourth lens group L4 includes a lens and a fourth lens holding frame (lens chamber) 18 for holding the lens, and is arranged so that the fourth lens holding frame 18 is supported by the third moving cylinder 11.

The fifth lens group L5 is a focus lens group, includes a lens and a fifth lens holding frame (lens chamber) 19 for holding the lens, and the fifth lens holding frame 19 is placed in the fourth moving cylinder 12 in the axis O1 direction. It is arranged so that it can move forward and backward.

The sixth lens group L6 includes a lens and a sixth lens holding frame (lens chamber) 20 for holding the lens, and the sixth lens holding frame 20 is fixed to the second cam cylinder 8 and arranged.

Then, in the lens barrel 1 of the present embodiment, when the zoom operation ring 5 rotates in the forward and reverse directions, the first cam cylinder 7 and the second cam cylinder 8 rotate in the forward and reverse directions, and the first to sixth lens groups L1 to L6 Are relatively moved back and forth in the direction of the axis O1 along the optical axis direction and are zoomed.

Here, the third lens group L3 is provided with an aperture mechanism (aperture unit) B.

As shown in FIGS. 1, 2, and 3, the drawing mechanism B of the present embodiment rotatably supports a substantially annular rotating member 25, which is a so-called hachinos, and the rotating member 25 around the axis O1. The holding member 26, the plurality of throttle blades 27 that follow the forward / reverse rotation of the rotating member 25, and the so-called arrow wheel, for driving the plurality of throttle blades 27 in the forward / reverse rotation around the axis O1 of the rotating member 25. A cam member 28 and a throttle drive motor 29 such as a stepping motor for rotating the rotating member 25 forward and reverse around the axis O1 are provided.

The holding member 26 is formed, for example, in a substantially annular shape, is arranged coaxially on the inner diameter side of the third moving cylinder 11, and has an axis O1 relative to the third moving cylinder 11 by a drawing cam mechanism described later. It is supported and arranged so that it can move forward and backward in the direction. At this time, the holding member 26 is integrally attached to the third lens holding frame 17 by screwing, etc., and is arranged together with the third lens holding frame 17 on the inner diameter side of the third moving cylinder 11 to be supported so as to be able to move forward and backward. ing.

The rotating member 25 is provided with a plurality of blade fitting holes 25a at predetermined intervals in the circumferential direction of the center of the axis O1, and is formed in a substantially disk shape. The rotating member 25 is coaxially arranged on the inner diameter side of the holding member 26, and is rotatably supported by the holding member 26 around the axis O1.

The diaphragm blade 27 has, for example, a substantially triangular shape in a plan view, and is formed with a rotating shaft convex portion 27a projecting from one surface on one surface side and a follower convex portion 27b projecting from the other surface on the other surface side. .. The diaphragm blade 27 is rotatably arranged around the convex portion 27a of the rotating shaft by fitting the convex portion 27a of the rotating shaft into the blade fitting hole 25a of the rotating member 25.

The cam member 28 is formed in a substantially disk shape, and is arranged coaxially with the holding member 26 and the rotating member 25 on the inner diameter side of the holding member 26. In the cam member 28, the follower convex portion 27b of the diaphragm blade 27 is inserted and arranged on one surface, the follower convex portion 27b is guided along with the forward and reverse rotation of the rotating member 25, and the plurality of diaphragm blades 27 are each centered on the rotating member 25. A plurality of cam grooves 31 are provided to move the opening / closing / opening / closing movement with respect to the opening 30 of the hole.

In the diaphragm mechanism B of the present embodiment, for example, nine diaphragm blades 27 are evenly arranged in the circumferential direction around the center of the axis O1 of the rotating member 25 and the cam member 28, and the rotating member 25 is aligned with the axis by the diaphragm drive motor 29. Nine diaphragm blades 27 are provided so as to rotate forward and reverse around O1 and open and close with respect to the opening 30 of the central hole of the rotating member 25. Thereby, the open diameter / aperture diameter of the opening 30 can be adjusted according to the amount of rotation of the rotating member 25. For example, when an instruction to change the aperture value is received from the camera body 100, the aperture drive motor 29 rotates the rotating member 25 and changes the size of the opening formed by the nine aperture blades 27.

On the other hand, the diaphragm mechanism B of the present embodiment includes a mounting portion 32 for mounting the holding member 26 and the cam member 28, as shown in FIGS. 2, 3, and 4. The holding member 26 and the cam member 28 can be attached (attached / detached) by the attachment portion 32 by relatively rotating around the shaft O1 line. For example, the cam member 28 is attached to the holding member 26 by rotating it around the axis O1. Further, the holding member 26 and the cam member 28 sandwich the rotating member 25 and the plurality of diaphragm blades 27 for positioning.

As the mounting portion 32, for example, a bayonet mechanism can be applied.

The mounting portion 32 of the bayonet mechanism is, for example, a bayonet claw 32a and a claw receiving surface extending in the circumferential direction with a predetermined interval in the circumferential direction of the center of the axis O1 on the outer peripheral edge side of each of the holding member 26 and the cam member 28. 32b is provided.

Then, as shown in FIGS. 4, 5, 6, and 7, the cam member 28 is arranged so as to overlap the holding member 26 so that the axes O1 of each other are coaxially arranged, and the cam member 28 is held. The claw receiving surface 32b of the cam member 28 is inserted between the adjacent bayonet claws 32a of the member 26, and the holding member 26 and the cam member 28 are relatively rotated around the axis O1. When rotated in this way, the bayonet claw 32a and the claw receiving surface 32b of the holding member 26 and the cam member 28 are overlapped and engaged with each other, and the cam member 28 can be detachably attached to the holding member 26. As a result, the plurality of diaphragm blades 27 and the rotating member 25 arranged between the holding member 26 can be sandwiched between the cam member 28 and the holding member 26 for positioning and holding. At this time, the cam member 28 in which the bayonet claw 32a and the claw receiving surface 32b overlap and engage with the holding member 26 is rotatably attached to the holding member 26 around the axis O1.

Here, in the present embodiment, as shown in FIGS. 5, 6 and 7, each cam groove 31 provided on one surface side of the cam member 28 is a follower convex portion when the cam member 28 is attached to the holding member 26. It is formed to include a first section 31a in which the 27b moves and a second section 31b in which the follower convex portion 27b moves during shooting. In other words, in each cam groove 31, the follower convex portion 27b of the diaphragm blade 27 is inserted and arranged when the claw receiving surface 32b of the cam member 28 is inserted between the adjacent bayonet claws 32a of the holding member 26, and the cam member 28 is inserted. Is provided relative to the holding member 26, and a guide groove (first section 31a) is provided to guide the follower convex portion 27b to the cam groove (second section 31b) used at the time of photographing.

Further, the cam member 28 of the present embodiment penetrates the first section (induction groove) 31a of the cam groove 31 from one surface to the other surface of the cam member 28, and holds the claw receiving surface 32b of the cam member 28 of the holding member 26. When inserting between the adjacent bayonet claws 32a, the follower convex portion 27b of the aperture blade 27 faces from the other surface side of the cam member 28, and the follower convex portion 27b of the plurality of aperture blades 27 faces each of the plurality of cam grooves 31. A confirmation hole 33 is provided in the first section 31a for suitable insertion and placement.

By providing the first section 31a of the cam groove 31 and the confirmation hole 33, the holding member 26 and the cam member 28 are relatively rotated around the axis O1 to assemble the holding member 26 and the cam member 28, and the follower. By arranging the convex portion 27b in the cam groove 31, it becomes possible to preferably arrange the plurality of diaphragm blades 27.

In the present embodiment, the mounting portion 32 is a bayonet mechanism, but the mounting portion 31 is not necessarily limited to the bayonet mechanism as long as the holding member 26 and the cam member 28 can be mounted in a rotatable state. May be good.

Further, in the throttle mechanism B of the present embodiment, not only the cam member 28 but also the rotating member 25 is rotatably attached to the holding member 26 by the same bayonet mechanism (mounting portion 32) as described above.
That is, in the throttle mechanism B of the present embodiment, the rotating member 25 is rotatably attached to the holding member 26 by the bayonet mechanism, the diaphragm blade 27 is attached to the rotating member 25, and the cam member 28 is rotated to the holding member 26 by the bayonet mechanism. Install as possible. Further, the motor 29 is attached to the holding member 26 at an appropriate stage, connected to the rotating member 25, and assembled. Then, the aperture mechanism B assembled in this way is attached to the third lens holding frame 17, and the aperture mechanism B is assembled to the third moving cylinder 11 together with the third lens holding frame 17, and the installation on the third moving cylinder 11 is completed. do.

As described above, the mounting portion 32 can directly mount the holding member 26 and the cam member 28 in a state where the cam member 28 can rotate with respect to the holding member 26. Therefore, it is not necessary to use another member for attaching the cam member 28 to the holding member 26 in a rotatable state, so that the number of parts can be reduced, the cost can be reduced, and the thickness in the optical axis direction can be reduced. Further, since the holding member 26 and the cam member 28 are directly attached, fluttering in the optical axis direction can be suppressed.

As shown in FIGS. 2, 4, 7, and 8, the drawing mechanism B of the present embodiment has one end connected to the holding member 26 and the other end connected to the cam member 28 to connect the first spring member 35. Is installed.

The first spring member 35 is provided so as to generate an urging force (elastic force) along the optical axis (O1) direction and an urging force along the rotation direction about the optical axis (O1). In the present embodiment, the first spring member 35 is arranged so as to urge the cam member 28 in one direction around the axis O1 and to urge the cam member 28 toward the bayonet claw 32a of the holding member 26. .. Further, in the present embodiment, a plurality of (three in the present embodiment) first spring members 35 are evenly arranged at equal intervals in the circumferential direction of the center of the axis O1.

One end of the first spring member 35 is connected to the third lens holding frame 17 to which the holding member 26 is screwed and integrally attached, and one end of the first spring member 35 is indirectly connected to the holding member 26. You may. In other words, the holding member 26 and the third lens holding frame 17 may be composed of one member instead of a separate member. In that case, the third lens holding frame 17 and the cam member 28 are formed by the first spring member 35. You just have to urge. That is, the third lens holding frame 17 and the holding member 26 of the present embodiment may serve as a holding member.

Next, with respect to the diaphragm mechanism B (holding member 26, rotating member 25, diaphragm blade 27, cam member 28, diaphragm drive motor 29) of the present embodiment, FIGS. 4 and 9, FIGS. 10 and 11, and FIG. This will be described with reference to FIG. 13 and the like.
As shown in FIG. 4, the third moving cylinder 11 has a cam follower 11a, and the cam follower 11a is engaged with a cam groove and a straight groove (not shown). As a result, the third moving cylinder 11 moves straight in the optical axis direction as the zoom operating ring 5 rotates. Further, the third lens holding frame 17 has a cam follower 17a, and the cam follower 17a is engaged with a cam groove and a straight groove (not shown). As a result, as the zoom operation ring 5 rotates, it moves straight in the optical axis direction together with the aperture mechanism B. Further, since the cam follower 11a and the cam follower 17a are engaged with different cam grooves, the movement trajectories of the third moving cylinder 11, the third lens holding frame 17, and the aperture mechanism B are different. That is, the third moving cylinder 11, the third lens holding frame 17, and the aperture mechanism B move relatively in the optical axis direction.
Further, as the diaphragm mechanism B moves with respect to the third moving cylinder 11 in the optical axis direction, the cam member 28 is rotated with respect to the third moving cylinder 11 by the diaphragm cam mechanism 40.

That is, in the diaphragm mechanism B of the present embodiment, the rotary member 25 rotates forward and reverse around the axis O1 by the diaphragm drive motor 29, and the diaphragm blades 27 move to adjust the open diameter / diaphragm diameter of the opening 30. In addition to this, when the zoom operation ring 5 is rotated, the third moving cylinder 11 and the aperture mechanism B move forward and backward in the axis O1 direction, respectively, and when the aperture mechanism B moves relative to the third moving cylinder 11. In addition, the cam member 28 is rotated relative to the third moving cylinder 11 by the diaphragm cam mechanism 40. As a result, the cam member 28 rotates to move the diaphragm blade 27, and the open diameter / diaphragm diameter of the opening 30 changes.

Specifically, as shown in FIGS. 3, 5 to 8, 4 and 9, FIG. 10 and FIG. 11, and FIGS. 12 and 13, the aperture cam mechanism 40 is radially from the outer circumference of the cam member 28. The diaphragm follower pin 41 protruding outward and the diaphragm cam groove (cam surface) 42 projecting on the inner surface of the third moving cylinder 11 are provided.

The follower pin 41 for drawing may be composed of an eccentric pin. For example, a follower main body 41a made of plastic and having a substantially cylindrical and circular outer peripheral surface and a follower main body 41a are screwed to a cam member 28. It is provided with a screw (fixed shaft portion) 41b for fixing the screw. Further, the follower pin 41 for drawing is fixed by screwing at an eccentric position deviated in the radial direction from the central axis of the follower main body 41a. Then, the follower pin 41 for drawing is inserted into the drawing cam groove 42 of the third moving cylinder 11 so that the outer peripheral surface of the follower main body 41a comes into contact with the cam surface (trajectory surface) 42a of the drawing cam groove 42. It is arranged.

Then, in the drawing mechanism B of the present embodiment, the first spring member 35 urges the follower pin 41 for drawing in the circumferential direction so as to be pressed against the cam surface 42a of the cam groove 42. Further, since the cam surface 42a of the cam groove 42 is arranged and formed so as to be inclined so that the follower pin 41 for aperture is urged in the optical axis direction (axis O1 direction), the follower pin 41 is from the cam surface 42a. It is pressed in the optical axis direction by the reaction force. That is, the urging force of the first spring member 35 in the optical axis direction and the reaction force of the cam groove 42 from the cam surface act in the same direction. As a result, the cam member 28 is pressed in the optical axis direction so that the cam member 28 rotates stably.

Further, in the third moving cylinder 11, a part of the diaphragm cam groove 42 is cut out on one end side of the third moving cylinder 11, and the diaphragm mechanism B advances relatively to one end side of the third moving cylinder 11. A notch (opening for adjusting the eccentric pin) 43 is provided to expose the follower pin 41 for aperture in the state. By providing the notch 43, the follower main body 41a of the diaphragm follower pin (eccentric pin) 41 exposed by the notch 43 can be rotated around the screw 41b of the eccentric shaft, whereby the follower main body can be rotated. The position of the outer peripheral surface of the portion 41a can be adjusted so as to be in contact with the cam surface 42a of the drawing cam groove 42, and the mounting position of the cam member 28 can be finely adjusted.

Further, in the aperture mechanism B of the present embodiment, as shown in FIGS. 4, 9, 10 and 11, the third moving cylinder 11 and the third lens holding frame 17 are connected to each other, and the third moving cylinder is connected. A second spring member 45 for urging the 11 and the holding member 26 is provided. A plurality of second spring members 45 are arranged along the optical axis direction and at equal intervals in the circumferential direction of the axis O1 center of the third moving cylinder 11 and the third lens holding frame 17 (three in the present embodiment). ) It is provided. As a result, the outer peripheral surface of the follower main body 41a can be pressed against the cam surface 42a of the throttle cam groove 42, and rattling and fluttering can be suppressed.

The aperture mechanism B (and the optical device (lens barrel 1, camera A)) of the present embodiment having the above configuration is provided with a mounting portion 32 for rotatably attaching the holding member 26 and the cam member 28. In addition to the conventional diaphragm mechanism, that is, the holding member 26, the rotating member 25, the diaphragm blade 27, and the cam member 28, another member is provided, the holding member and the other member are fixed, and the holding member and the other member are fixed. Compared with the conventional diaphragm mechanism that positions and holds the cam member, the diaphragm blade, and the rotating member by sandwiching the cam member, the diaphragm blade, and the rotary member, other members can be eliminated and the number of parts can be reduced. Since the number of parts is reduced, the thickness in the optical axis direction is reduced and the cost is reduced.

Further, the cam member 28 is rotatably attached to the holding member 26 by the mounting portion 32, and the rotating member 25 and the plurality of diaphragm blades 27 are positioned and held so as to be sandwiched between the holding member 26 and the cam member 28. Can be done. Further, the rotating member 25 is also directly attached to the holding member 26 by, for example, a bayonet structure. Therefore, the holding member 26 and the cam member 28 are directly attached as compared with the conventional diaphragm mechanism in which the cam member, the diaphragm blade, and the rotating member are sandwiched and held between the holding member and the other member. Therefore, rattling does not easily occur in each member, and each member can be assembled with high accuracy. This makes it possible to effectively improve the rotational stability of the rotating member 25 and the cam member 28, and by extension, the stability of the appearance / opening / closing movement of the plurality of diaphragm blades 27. Optical performance is also improved.

Further, in the throttle mechanism B of the present embodiment, the cam groove 31 of the cam member 28 is the first section (induction groove) in which the follower convex portion 27b of the diaphragm blade 27 moves when the cam member 28 is attached to the holding member 26. It is formed with 31a and a second section 31b in which the follower convex portion 27b moves during photographing.
As a result, the holding member 26 and the cam member 28 are assembled by rotating them relative to the axis O1, and at the same time, the follower convex portion 27b of the diaphragm blade 27 is surely and preferably the second section of the cam groove 31 through the first section 31a. It can be inserted and placed in 31b.

The throttle mechanism B of the present embodiment includes a first spring member 35 that urges the cam member 28 in one direction around the axis O1 and urges the cam member 28 toward the bayonet claw 32a of the holding member 26. There is.
Since the first spring member 35 can be urged in the circumferential direction and the optical axis direction, it is possible to accurately control the rotation of the cam member 28 and the opening / closing movement of the plurality of diaphragm blades 27. Further, the holding member 26, the cam member 28, the rotating member 25, and the plurality of diaphragm blades 27 can be positioned and assembled with high accuracy while suppressing rattling.

In the diaphragm mechanism B of the present embodiment, the diaphragm cam that rotates the cam member 28 with respect to the third moving cylinder 11 as the diaphragm mechanism B moves in the optical axis direction with respect to the third moving cylinder 11. The mechanism 40 is provided. Further, the diaphragm follower pin (pin) 41 of the diaphragm cam mechanism 40 is an eccentric pin.
As a result, the holding member 26, the rotating member 25, the cam member 28, and the plurality of diaphragm blades 27 are assembled, arranged at a predetermined position inside the third moving cylinder 11, and then eccentric screw (fixed shaft portion) 41b. By simply rotating the follower main body 41a around, the circular outer peripheral surface of the follower main body 41a can be reliably brought into contact with the cam surface 42a of the throttle cam groove 42 of the third moving cylinder 11. Therefore, by using the follower pin 41 for the diaphragm as an eccentric pin, the assembly error can be absorbed and adjusted, and the diaphragm mechanism B and the third moving cylinder 11 can be easily and suitably assembled. ..

Further, in the aperture mechanism B of the present embodiment, the third moving cylinder 11 is formed to include a follower pin 41 for drawing to be exposed to the outside of the third moving cylinder 11 (an eccentric pin adjusting opening) 43. There is.
As a result, the diaphragm mechanism B can be arranged so that the diaphragm follower pin 41 is exposed from the notch 43 during the assembly work of the diaphragm mechanism B and the third moving cylinder 11, and the follower pin 41 can be arranged from the outside through the notch 43. By simply rotating the follower body 41a, the outer peripheral surface of the follower main body 41a can be easily brought into contact with the cam surface 42a of the throttle cam groove 42 of the third moving cylinder 11. That is, by rotating the diaphragm follower pin 41 of the eccentric pin, the contact position with the cam surface 42a can be changed, the angular position of the cam member 28 is adjusted, and the opening diameter of the diaphragm blade 27 is adjusted. Becomes possible. Therefore, it becomes possible to more easily and preferably perform the assembly work of the diaphragm mechanism B and the third moving cylinder 11.

Further, the first spring member 35 is provided by urging the cam member 28 in one direction around the axis O1 and urging the cam member 28 toward the bayonet claw 32a side of the holding member 26. The urging force of the member 35 makes it possible to preferably bring the outer peripheral surface of the follower main body 41a into contact with the cam surface 42a of the throttle cam groove 42 of the third moving cylinder 11. Thereby, the rotational stability of the cam member 28 can be further improved.

In the aperture mechanism B of the present embodiment, the third moving cylinder 11 and the third lens holding frame 17 are connected, and the third moving cylinder 11 and the third lens holding frame 17 are urged in the direction along the axis O1. A second spring member 45 is provided.
As a result, the outer peripheral surface of the follower main body 41a can be pressed against the cam surface 42a of the diaphragm cam groove 42a, and the holding member 26, the cam member 28, the diaphragm blade 27, the rotating member 25, and the third moving cylinder 11 can be pressed against each other. It is possible to assemble with higher accuracy so that each member does not rattle. Further, it is possible to further improve the rotational stability of the cam member 28.

In the diaphragm mechanism B of the present embodiment, a confirmation hole for visually recognizing the follower convex portion 27b of the diaphragm blade 27 which penetrates from one surface of the cam member 28 to the other surface and is inserted and arranged in the first section 31a of the cam groove 31. 33 is provided.
As a result, when the holding member 26 and the cam member 28 are assembled by relatively rotating, it is confirmed that the follower convex portions 27b of the plurality of diaphragm blades 27 are surely inserted and arranged in the first section 31a of the cam groove 31. It can be confirmed in the hole 33. Therefore, the holding member 26 and the cam member 28 can be assembled by relatively rotating the holding member 26 and the cam member 28 in a state where the follower convex portions 27b of the plurality of diaphragm blades 27 are surely inserted and arranged in the first section 31a, and the diaphragm mechanism B can be easily assembled. Moreover, it becomes possible to assemble with high accuracy.

Further, in the drawing mechanism B of the present embodiment, as shown in FIGS. 4, 14 and 15, a straight groove 46 is provided in the third moving cylinder 11 which is a straight cylinder, and the holding member 26 (or the holding member 26) is provided. A straight convex portion 47 may be provided on the integrated third lens holding frame 17), and the straight groove 46 and the straight convex portion 47 may be engaged with each other.
With this configuration, the accuracy of the angular position of the third moving cylinder 11 and the holding member 26 (throttle mechanism B) can be improved, and as a result, the follower pin 41 for drawing the eccentric pin and the cam groove 42 for drawing can be improved. It is possible to improve the positional accuracy of the cam surface 42a.

Further, in the lens barrel 1 of the present embodiment and the optical device of the camera (imaging device) A, by providing the aperture mechanism B of the present embodiment, it is possible to obtain the action and effect of the above-mentioned aperture mechanism B. Become.
Further, in the embodiment, an example in which the third lens holding frame 17 and the holding member 26 are composed of separate members has been described, but the present invention is not limited to this. For example, the third lens holding frame 17 and the holding member 26 may be one member integrally formed. In that case, the member may or may not hold the lens.
Further, in the embodiment, an example has been described in which the cam member 28, the diaphragm blade 27, the rotating member 25, and the holding member 26 are arranged in this order from the subject side, and the rotating member 25 is rotated by the diaphragm drive motor 29. Not limited to. For example, the rotating member 25, the diaphragm blade 27, the cam member 28, and the holding member 26 may be arranged in this order from the subject side. In this case, even if the cam member 28 is rotated by the diaphragm drive motor 29, or the rotating member 25 has a follower pin 41 for diaphragm, and the size of the opening of the diaphragm blade 27 is changed. good.

Therefore, according to the diaphragm mechanism B and the optical device of the present embodiment, the number of member points of the diaphragm mechanism B is reduced, the assembly accuracy is improved, the rotational stability of the cam member 28 is improved, and the efficiency of the assembly work is improved. It is possible to improve performance, reduce costs, reduce size, and reduce thickness.

Although one embodiment of the diaphragm mechanism and the optical device has been described above, the present invention is not limited to the above-mentioned one embodiment, and can be appropriately changed as long as the purpose is not deviated, and any combination may be used.

1 Lens lens barrel 5 Zoom operation ring 11 3rd moving cylinder 17 3rd lens holding frame 25 Rotating member 25a Blade fitting hole 26 Holding member 27 Aperture blade 27a Rotating shaft convex part 27b Follower convex part 28 Cam member 29 Aperture drive motor 30 Opening 31 Cam groove 31a 1st section 31b 2nd section 32 Mounting part 32a Bayonet claw 32b Claw receiving surface 33 Confirmation hole 35 1st spring member 40 Squeezing cam mechanism 41 Squeezing follower pin 41a Follower body 41b Screw (fixed) Shaft)
42 Aperture cam groove 42a Cam surface (track surface)
43 Notch (opening for eccentric pin adjustment)
45 Second spring member 46 Straight groove 47 Straight convex part 100 Camera body A Camera (optical equipment)
B Aperture mechanism O1 Axis line (optical axis OA)

Claims (11)

The first member having a cam groove and
The second member with a hole and
A diaphragm blade having a first protrusion that engages with the hole and a second protrusion that engages with the cam groove.
A holding member that rotatably holds at least one of the first member or the second member is provided.
A diaphragm mechanism in which the first member or the other of the second member and the diaphragm blades are arranged between the one and the holding member. The cam groove has a first section in which the first protrusion moves when the first member is attached to the holding member, and a second section in which the first protrusion moves during photographing. Aperture mechanism described in. The drawing mechanism according to claim 1 or 2, further comprising a first elastic member connecting the holding member and the first member. The drawing mechanism according to claim 3, wherein the first elastic member generates an elastic force along the optical axis direction and an elastic force along the rotation direction about the optical axis. The first member has a pin
A tubular member having a cam surface that comes into contact with the pin is provided.
The throttle mechanism according to claim 3 or 4, wherein the pin and the cam surface are brought into contact with each other by the first elastic member. The throttle mechanism according to claim 5, further comprising a second elastic member that connects the tubular member and the holding member. The pin is an eccentric pin
The throttle mechanism according to claim 5 and 6, wherein the tubular member has a notch for adjusting the eccentric pin. According to claim 5, when the operation ring rotates, the position where the pin comes into contact with the cam surface changes, so that the first member rotates and the size of the opening formed by the plurality of diaphragm blades changes. The aperture mechanism according to any one of claims 7. A drive unit for driving the second member is provided.
Any of claims 1 to 8, wherein when the driving unit rotates the second member, the size of the opening formed by the plurality of diaphragm blades changes through the hole and the second protrusion. The aperture mechanism according to item 1. A motor provided on the holding member and rotating the second member is provided.
The diaphragm mechanism according to any one of claims 1 to 9, wherein the size of the opening formed by the plurality of diaphragm blades is changed by rotating the second member by the motor. An optical device comprising the diaphragm mechanism according to any one of claims 1 to 10.

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