JP7140265B2 - lens barrel - Google Patents

Description

The present invention relates to a lens barrel.

The lens barrel must be prevented from rattling.

JP-A-7-120651

A lens barrel according to a first aspect includes a first member having a first projection, a second member having a second projection, and arranged radially outside or inside the first member, and a third member having a groove that engages with the first protrusion and the second protrusion; and an elastic member disposed between the first member and the second member along the optical axis direction. and the second member is supported by the elastic member so as to be movable in the optical axis direction with respect to the first member, and the distance between the center of the first projection and the center of the second projection is variable. According to the elastic member, the first projection contacts one side surface of the groove and the other side surface of the groove, and the second projection contacts the other side surface of the groove.

It is a sectional view showing lens barrel 1 of a 1st embodiment, and shows the state where an upper part and a lower part differ in focal length. FIG. 2 is an enlarged perspective view showing the cylinder configuration of the dotted line portion in FIG. 1, showing a fixed cylinder 14 and a straight cylinder 15; It is a cross-sectional view showing the inner circumference of the rotating cylinder 13, and also shows the bearing 14b, the bearing 16b, and the spring 17. FIG. FIG. 6 is a partial cross-sectional view showing a lens barrel 201 of a second embodiment; 4 is an exploded view of a rotating barrel 213; FIG. FIG. 3 is a perspective view showing a rectilinear barrel 215 and a backlash-removing structure 200 of a lens barrel 201; Fig. 2 is an exploded perspective view of the backlash-removing structure 200 viewed from the inner diameter side; FIG. 3 is a partial view of a connecting tube 224 and a rotating tube 213 indicated by a dotted line arranged outside the connecting tube 224 and viewed from the outside in the radial direction. FIG. 10 is a diagram showing a cam groove 213a' of a comparative form; It is a partial perspective view of the lens barrel 301 of 3rd Embodiment, and shows the state except the outer cylinder 350. FIG. FIG. 11 is a cross-sectional view taken along line AA of FIG. 10, showing a state in which an outer cylinder 350 is arranged on the outer circumference of the inner cylinder 310 shown in FIG. 10; 11. It is the BB sectional view of FIG. 10 which shifted|deviated from the AA sectional view of FIG. 11 in the circumferential direction. It is a partial perspective view of the lens barrel 401 of 4th Embodiment, and shows the state except the outer cylinder 450. FIG. 14 is a cross-sectional view taken along line CC of FIG. 13, showing a state in which an outer cylinder 450 is arranged on the outer circumference of the inner cylinder 410 shown in FIG. 13. FIG.

(First embodiment)
Hereinafter, the lens barrel 1 of the first embodiment will be described with reference to the drawings. FIG. 1 is a cross-sectional view showing the lens barrel 1 of the first embodiment, and shows a state in which the upper portion and the lower portion in FIG. 1 have different focal lengths.
The lens barrel 1 is an interchangeable lens barrel 1 that has a lens side mount portion 11 on the right side in the drawing and can be attached to and detached from a body side mount portion (not shown) provided on the camera body 2 . However, it is not limited to this, and a lens barrel integrated with the camera body 2 may be used.
Hereinafter, the left side of the drawing along the optical axis OA is called the object side, and the right side of the drawing is called the image side.

The lens barrel 1 includes a focus ring 12 from the outer peripheral side, a rotary barrel 13 arranged on the inner peripheral side of the focus ring 12 on the subject side, and rotating integrally with the focus ring 12, and the rotary barrel 13 arranged on the inner peripheral side of the rotary barrel 13. a fixed barrel 14 extending further toward the image side than the rotary barrel 13;

In this embodiment, the lens barrel 1 is a two-group single-focus lens, and includes a first-group lens L1 and a second-group lens L2. However, it is not limited to a single focus lens with a two-group configuration. For example, it may be a zoom lens, or may be composed of more groups.
The 1-group lens L1 includes a 1-1 group lens L11, a 2-1 group lens L12, a 3-1 group lens L13, a 4-1 group lens L14, and a 5-1 group lens L15. , a 6-1st group lens L16, and a 7-1st group lens L17.
The outer periphery of the 1-1 group lens L11 is held by the 1-1 group lens holding frame 21, the outer periphery of the 2-1 group lens L12 is held by the 2-1 group lens holding frame 22, and the 3-1 group The outer circumference of the lens L13 is held by the 3-1st group lens holding frame 23, the outer circumference of the 4-1st group lens L14 is held by the 4-1st group lens holding frame 24, and the outer circumference of the 5-1st group lens L15 is held by the 4-1st group lens holding frame 24. The 6-1st group lens L16 is held by the 5-1st group lens holding frame 25, the outer periphery of the 6-1st group lens L16 is held by the 6-1st group lens holding frame 26, and the 7th-1st group lens L17 is held by the 7-1st group lens. It is held by the lens holding frame 27 .

The 3rd-1st group lens holding frame 23, the 4th-1st group lens holding frame 24, and the 5th-1st group lens holding frame 25 are fixed to a second rectilinear movement cylinder 32 arranged on the outer periphery thereof. ing. The second rectilinear movement barrel 32 is screwed to the rectilinear barrel 15 .
Therefore, when the rectilinear movement barrel 15 advances straight, the second rectilinear movement barrel 32 advances straight, whereby the 3rd-1st group lens holding frame 23, the 4th-1st group lens holding frame 24, and the 5-1st group lens holding frame The frame 25 advances straight, so the third-first group lens L13, the fourth-first group lens L14, and the fifth-first group lens L15 advance straight.

The 1st-1st group lens holding frame 21 and the 2nd-1st group lens holding frame 22 are fixed to a first rectilinear movement cylinder 31 arranged on the outer periphery thereof. The first rectilinear movement barrel 31 is screwed to the end of the second rectilinear movement barrel 32 on the object side.
Therefore, when the rectilinear movement barrel 15 moves straight, the first rectilinear movement barrel 31 moves rectilinearly together with the second rectilinear movement barrel 32, whereby the 1st-1st group lens holding frame 21 and the 2nd-1st group lens holding frame 22 move. It goes straight, so the 1-1 group lens L11 and the 2-1 group lens L12 go straight.

The 6-1st group lens holding frame 26 and the 7th-1st group lens holding frame 27 are fixed to the rectilinear barrel 15 . Therefore, when the rectilinear barrel 15 advances straight, the 6-1st group lens holding frame 26 and the 7-1st group lens holding frame 27 advance straightly. and go straight.
In other words, the straight movement of the straight movement barrel 15 causes the entire first group lens L1 to move straight.

The second group lens L2 is held by a second group lens holding frame 28, and the second group lens holding frame 28 is fixed to the fixed barrel 14 on the image side.

FIG. 2 is an enlarged perspective view showing the cylinder construction of the dotted line portion in FIG.
(Fixed barrel 14)
As shown in FIG. 1, the fixed barrel 14 is a cylindrical member having a large diameter on the object side and a small diameter on the image side. Note that the shape of the fixed cylinder 14 is not limited to this, and may be a shape having substantially the same diameter on the object side and the image side. As shown in FIG. 2, approximately rectangular recesses 14a are formed in the circumferential direction of the fixed barrel 14 on the object side at three equal locations in the circumferential direction.

(Bearing 14b)
A bearing 14b is attached to a portion adjacent to the concave portion 14a in the circumferential direction at the object-side end of the fixed barrel 14 so as to protrude outward. In other words, the recess 14a and the bearing 14b are attached so that at least a part of them overlap in the circumferential direction. The bearings 14b are attached at three locations corresponding to the recesses 14a provided at three locations in the circumferential direction. In addition, the positions at which the recessed portion 14a and the bearing 14b are provided are not limited to three even positions in the circumferential direction. It may be two or less, or four or more. Also, they may be arranged unevenly.

(First annular member 16)
A first annular member 16 having substantially the same diameter as the fixed barrel 14 is arranged on the object side of the fixed barrel 14 .
Approximately rectangular convex portions 16a extending toward the fixed barrel 14 side (image side) are provided at three locations in the circumferential direction of the circumferential end face of the first annular member 16 on the fixed barrel 14 side (image side). there is
The concave portion 14a of the fixed barrel 14 and the convex portion 16a of the first annular member 16 have substantially the same shape, and the first annular member 16 is mounted on the subject side of the fixed barrel 14 so that the convex portion 16a is fitted in the concave portion 14a. are placed.

(Spring 17)
Two holes 16c extending toward the subject are provided in the end face of the convex portion 16a on the fixed barrel 14 side (image side). A spring 17 is inserted in each of the holes 16c.
The spring 17 is a compression spring that is longer than the depth of the hole 16c. The other end of the protrudes from the hole 16c and contacts the side surface of the concave portion 14a of the fixed barrel 14 facing the subject.

(Bearing 16b)
Bearings 16b are attached to the projections 16a of the first annular member 16 so as to protrude outward.

(Rotating cylinder 13)
FIG. 3 is a cross-sectional view showing the inner circumference of the rotary cylinder 13, and also shows the bearing 14b, the bearing 16b and the spring 17. As shown in FIG. A circumferential groove 13a is formed on the image side of the inner circumference of the rotating barrel 13 so as to extend along the circumference centered on the optical axis OA. As shown, the outer diameter of bearing 14b and the outer diameter of bearing 16b are approximately equal to or less than the width of circumferential groove 13a.
A spiral helicoid groove 13b centered on the optical axis OA is formed in the inner circumference of the rotating barrel 13 on the object side of the circumferential groove 13a.

In FIG. 3, dotted lines indicate a portion of the fixed cylinder 14 where the concave portion 14a is provided and a portion of the first annular member 16 where the convex portion 16a is provided.

(Structure for removing looseness in circumferential groove 13a)
As described above, the first annular member 16 is arranged on the subject side of the fixed barrel 14, and is arranged so that the convex portion 16a of the first annular member 16 fits into the concave portion 14a of the fixed barrel 14. As shown in FIG. Therefore, the bearing 14b and the bearing 16b are arranged so that at least a part thereof overlaps in the circumferential direction around the optical axis. This facilitates engagement with the same groove (circumferential groove 13a). The rotating barrel 13 is arranged on the outer peripheral side of the fixed barrel 14 and the first annular member 16 . The bearing 14 b of the fixed cylinder 14 and the bearing 16 b of the first annular member 16 are arranged in the circumferential groove 13 a of the rotary cylinder 13 .
At this time, the spring 17 is arranged between the side surface of the concave portion 14a of the fixed barrel 14 facing the object side and the bottom surface of the hole 16c of the first annular member 16 facing the image side. A spring 17 biases the first annular member 16 away from the fixed barrel 14 .

Then, the bearing 16b fixed to the first annular member 16 is pressed in the direction indicated by the arrow F1 in FIG. On the other hand, the bearing 14b of the fixed cylinder 14 is pressed in the direction indicated by the arrow F2 in FIG. 3, and contacts the image-side side surface of the circumferential groove 13a.
For this reason, the rotating barrel 13 is pressed by bearings 16b on the subject side surface of a circumferential groove 13a provided on the inner periphery thereof, and by bearings 14b on the image side surface thereof. Therefore, the rotating barrel 13 and the fixed barrel 14 are held without backlash. The bearing 14b may be in contact with both the image-side side surface and the subject-side side surface of the circumferential groove 13a. As a result, the bearing 14b can move without backlash in the circumferential groove 13a as a main bearing for movement. Alternatively, the bearing 16b may contact the subject-side side surface of the circumferential groove 13a and not the image-side side surface. As a result, the bearing 16b can move in the circumferential groove 13a as a bearing for removing looseness without excessive restraint. Each lens can be moved in the optical axis direction by moving the bearing 14b along the image-side side surface of the circumferential groove 13a.
The term "backlash" refers to relative movement between members caused by manufacturing errors, clearances intentionally provided at the time of mechanical design and required for assembly, and the like. Also, "removing backlash" means removing this relative movement.

That is, by providing the first annular member 16 separately from the fixed barrel 14 and biasing the fixed barrel 14 and the first annular member 16, the play of the rotary barrel 13 with respect to the fixed barrel 14 can be eliminated.

At this time, the rotary barrel 13 rotates with respect to the fixed barrel 14 and the first annular member 16, but both sides of the circumferential groove 13a provided on the inner circumference of the rotary barrel 13 are pressed by the bearings 14b. and the bearing 16b, the rotation of the rotary cylinder 13 is not hindered.

In the embodiment, three backlash-removing structures for pressing both side surfaces of the circumferential groove 13a with the bearings 14b and 16b are provided in the circumferential direction. can be
Further, in the embodiment, the bearing 14b and the bearing 16b are provided as a looseness removing structure, but the structure is not limited to bearings, and a pin or the like protruding to the outer peripheral side may be used. In the case of the pin, in the case of removing backlash between cylindrical members that rotate relative to each other, the outer surface may be smooth and slippery.

(Straight cylinder 15)
As shown in FIG. 1, the rectilinear barrel 15 has a large diameter on the subject side and a small diameter on the image side, similar to the fixed barrel 14, and has a helicoid screw 15c on the outer periphery of the straight barrel 15. A threaded portion 15C is provided. The shape of the rectilinear barrel 15 is not limited to this, and may be a shape having substantially the same diameter on the object side and the image side.
The helicoid screw 15c is screwed into the helicoid groove 13b of the rotary barrel 13 shown in FIG. 3, and when the rotary barrel 13 rotates, the helicoid screw 15c moves along the helicoid groove 13b. As a result, the rectilinear barrel 15 linearly moves (advances and retreats) in the optical axis OA direction with respect to the fixed barrel 14 and the rotary barrel 13 that rotates with respect to the fixed barrel 14 but does not move in the optical axis direction.

The upper part of FIG. 1 and FIG. 2 show a state in which the amount of protrusion of the rectilinear barrel 15 with respect to the fixed barrel 14 is the smallest, and only the threaded portion 15C of the rectilinear barrel 15 protrudes from the first annular member 16 and the fixed barrel 14 .
The lower part of FIG. 1 shows a state in which the amount of protrusion of the rectilinear barrel 15 with respect to the fixed barrel 14 is the largest. Approximately half of the large-diameter portion of the rectilinear barrel 15 protrudes toward the subject from the first annular member 16 and the fixed barrel 14 . However, the tip of the rectilinear barrel 15 does not protrude from the tip of the rotary barrel 13, and the engagement between the helicoid groove 13b of the rotary barrel 13 and the helicoid screw 15c of the rectilinear barrel 15 is maintained.

As shown in FIG. 2, approximately rectangular recesses 15a are provided at three positions in the circumferential direction of the object-side circular end surface of the rectilinear barrel 15 toward the image side.
(Bearing 15b)
A bearing 15b is attached to a portion of the rectilinear cylinder 15 adjacent in the circumferential direction to the portion provided with the recess 15a so as to protrude outward. In other words, the recess 15a and the bearing 15b are provided so as to overlap at least partially in the circumferential direction. The bearings 15b are attached at three locations in the circumferential direction, similar to the recesses 15a. The positions at which the recesses 15a and the bearings 15b are provided are not limited to three positions in the circumferential direction, and may be two positions or less, or four positions or more.

(Second annular member 18)
A second annular member 18 having substantially the same diameter as the rectilinear barrel 15 is arranged on the object side of the rectilinear barrel 15 .
Approximately rectangular projections 18a extending toward the rectilinear barrel 15 (image side) are provided at three locations in the circumferential direction of the circumferential end face of the second annular member 18 on the rectilinear barrel 15 side (image side). there is
The concave portion 15a of the rectilinear barrel 15 and the convex portion 18a of the second annular member 18 have substantially the same shape, and the second annular member 18 is arranged on the object side of the rectilinear barrel 15 so that the convex portion 18a is fitted in the concave portion 15a. It is

(Spring 18d)
Two holes 18c extending toward the subject are formed in the end face of the convex portion 18a on the side of the rectilinear barrel 15 (image side). A spring 18d is inserted into each hole 18c.
The spring 18d is a compression spring that is longer than the depth of the hole 18c. The other end protrudes from the hole 18c and abuts on the side surface of the recess 15a of the rectilinear barrel 15 facing the subject.

(Bearing 18b)
Bearings 18b are attached to the protrusions 18a of the second annular member 18 so as to protrude outward.

In FIG. 3, dotted lines indicate a portion of the rectilinear cylinder 15 where the concave portion 15a is provided and a portion of the second annular member 18 where the convex portion 18a is provided. As shown, the outer diameter of bearing 18b and the outer diameter of bearing 15b are approximately equal to or smaller than the width of helicoid groove 13b.

(Structure for removing looseness in helicoid groove 13b)
As described above, the second annular member 18 is arranged on the object side of the rectilinear barrel 15 , and arranged so that the convex portion 18 a of the second annular member 18 fits into the concave portion 15 a of the rectilinear barrel 15 . Therefore, the bearing 15b and the bearing 18b are arranged so that at least a part thereof overlaps in the circumferential direction around the optical axis. This facilitates engagement with the same groove (helicoid groove 13b). The rotary barrel 13 is arranged on the outer peripheral side of the rectilinear barrel 15 and the second annular member 18 . The bearing 15b of the rectilinear cylinder 15 and the bearing 18b of the second annular member 18 are arranged in the helicoid groove 13b of the rotary cylinder 13. As shown in FIG.
At this time, the spring 18d is arranged between the side surface of the concave portion 15a of the rectilinear barrel 15 facing the object side and the bottom surface of the hole 18c of the second annular member 18 facing the image side. The spring 18 d urges the second annular member 18 away from the rectilinear cylinder 15 .

Then, the bearing 18b fixed to the second annular member 18 is pressed in the direction indicated by the arrow F3 in FIG. On the other hand, the bearing 15b of the rectilinear cylinder 15 is pressed in the direction indicated by the arrow F4 and comes into contact with the side surface of the helicoid groove 13b on the image side.
For this reason, the rotating barrel 13 has a helicoid groove 13b provided in the inner periphery thereof, in which the subject-side side surface is pressed by the bearing 18b, and the image-side side surface is pressed by the bearing 15b. It is held without backlash. Note that the bearing 15b may contact both the side surface of the helicoid groove 13b on the image side and the side surface on the subject side. As a result, the bearing 15b can move without backlash in the helicoid groove 13b as a main bearing for movement. Alternatively, the bearing 18b may contact the object-side side surface of the helicoid groove 13b and not contact the image-side side surface of the helicoid groove 13b. As a result, the bearing 18b can move in the helicoid groove 13b as a bearing for removing looseness without excessive restraint. As the bearing 15b moves along the image-side side surface of the helicoid groove 13b, each lens moves in the optical axis direction.

In other words, a second annular member 18 is provided separately from the straight-moving barrel 15, and by urging the straight-moving barrel 15 and the second annular member 18, the looseness of the rotating barrel 13 with respect to the straight-moving barrel 15 or the straight-moving barrel with respect to the rotating barrel 13 is prevented. 15 backlashes can be removed.

At this time, the rotary barrel 13 rotates with respect to the rectilinear barrel 15 and the second annular member 18, but the bearings 18b and 18b hold down both side surfaces of the helicoid groove 13b provided on the inner circumference of the rotary barrel 13. 15b, the rotation of the rotary cylinder 13 is not hindered.

In the embodiment, the backlash-removing structure for pressing both side surfaces of the helicoid groove 13b by the bearings 15b and 18b is provided at three locations in the circumferential direction, but the number of locations is not limited, and for example, it may be provided at six locations. good.
Moreover, in the embodiment, the bearing 15b and the bearing 18b are provided as a backlash removing structure, and the structure is not limited to the bearing, and a pin or the like protruding to the outer peripheral side may be used. In the case of the pin, it is preferable that the outer surface of the pin is smooth and slippery in order to remove looseness between the cylindrical members that rotate relative to each other.

Also, the shape of the side surface of the helicoid groove 13b of the rotating barrel 13 may be different between the object side and the image side. As a result, the second annular member 18 can be prevented from tilting with respect to the rectilinear cylinder 15 . Also, the torque can be adjusted.

In the case of the helicoid groove 13b, the relative distance between the two bearings 15b and 18b in the direction of the optical axis OA may change. At this time, a relatively strong spring may be used so that the spring can be biased even if the relative distance increases.

Furthermore, in the case of a cylinder that directly holds the lens, the lens may be prevented from falling down by urging it with a particularly strong spring.
In the present embodiment, it is a single-focal lens with a two-group structure, and the backlash removal between the two cylinders that rotate relative to each other when the lens is driven during focusing has been described. The structure of the present embodiment can be used to remove looseness between two cylindrical members that rotate relative to each other, and the mechanical structure is not limited to the above-described embodiment.
In the embodiment, an example in which the rotating barrel 13 having the circumferential groove 13a or the helicoid groove 13b is arranged on the outer peripheral side relative to the fixed barrel 14, the rectilinear barrel 15, the first annular member 16, and the second annular member 18 will be described. However, it is not limited to this. The rotating cylinder 13 may be arranged on the inner peripheral side.

(Second embodiment)
Next, the lens barrel 201 of the second embodiment will be described with reference to the drawings.
FIG. 4 is a partial cross-sectional view showing the lens barrel 201 of the second embodiment. Like the lens barrel 1 of the first embodiment, the lens barrel 201 also has a lens side mount portion (not shown), and a body side mount portion (not shown) provided on the camera body (not shown). ) is an interchangeable lens barrel 201 that can be attached to and detached from. Note that a camera in which the body and the lens barrel are integrated may be used.

The lens barrel 201 of the second embodiment is a zoom lens, and includes at least a first lens group M1, a second lens group M2, and a third lens group M3. In the second embodiment, the second group lens M2 is the focus lens.

The outer periphery of the 1st group lens M1 is held by the 1st group lens holding frame 221, the outer periphery of the 2nd group lens M2 is held by the 2nd group lens holding frame 222, and the outer periphery of the 3rd group lens M3 is held by the 3rd group lens holding frame 223. ing.
The 1st group lens holding frame 221 and the 3rd group lens holding frame 223 are connected by a connecting cylinder 224 . A drive shaft 225 extends between the first group lens holding frame 221 and the third group lens holding frame 223 of the coupling barrel 224 . The second group lens holding frame 222 is held by a drive shaft 225, and is movable in the coupling barrel 224 in the optical axis OA direction by a drive section (not shown).

A rectilinear tube 215 is arranged on the outer periphery of the connecting tube 224 on the object side. The rectilinear cylinder 215 and the connecting cylinder 224 rectilinearly move together. A rotary cylinder 213 is arranged on the outer circumference of the rectilinear cylinder 215 .

(Rotating cylinder 213)
FIG. 5 is a developed view of the rotary barrel 213. As shown in FIG. A cam groove 213a is provided on the inner surface of the rotating cylinder 213 . The cam groove 213a is engaged with a bearing (main bearing) 215b and a bearing 250b that protrude outward from the rectilinear cylinder 215, as will be described later. The bearings 215b and 250b are arranged so that at least a portion of them overlap in the circumferential direction about the optical axis. This facilitates engagement with the same groove (cam groove 213a).
When the rotating barrel 213 rotates, the bearing 215b moves along the cam groove 213a, so that the rectilinear barrel 215 rectilinearly advances in the direction of the optical axis OA.
When the rectilinear advance barrel 215 advances straight, the 1st group lens holding frame 221, the 3rd group lens holding frame 223, and the 2nd group lens holding frame 222 held between them advance straightly together with the connecting barrel 224, that is, the 1st group lens M1. , the second group lens M2 and the third group lens M3 move in the optical axis direction. Further, the second lens group M2 is driven by a driving unit (not shown) in the optical axis direction with respect to the first lens group M1 and the third lens group M3, thereby adjusting the focus position.

FIG. 6 is a perspective view showing the rectilinear barrel 215 and the backlash removing structure 200 of the lens barrel 201. As shown in FIG. FIG. 7 is an exploded perspective view of the looseness removing structure 200 viewed from the inner diameter side.

(Straight cylinder 215)
As shown in FIG. 6, the rectilinear barrel 215 has grooves 215a extending along the optical axis OA at three even positions in the circumferential direction. The rectilinear cylinder 215 is provided with a bearing 215b protruding outward at a position slightly displaced in the circumferential direction from a position on the same straight line as the groove 215a.

(biasing force transmission member 250)
A biasing force transmission member 250 is arranged between the portion of the rectilinear cylinder 215 where the groove portion 215 a is provided and the rotary cylinder 213 . The biasing force transmission member 250 is a plate member extending in the optical axis OA direction, and has an opening 250a extending in the optical axis direction at its center. Long holes 251 and 252 are provided on both longitudinal sides of the biasing force transmission member 250 across the opening 250a. One of the long holes 251 and 252 in the longitudinal direction is circular. The object-side end of the opening 250 a of the biasing force transmission member 250 is bent radially inward to form a spring hook 255 . A bearing 250b projecting outward is attached to the image side of the biasing force transmission member 250. As shown in FIG.

A pin 253 is inserted through the elongated hole 251 and fixed to the rectilinear cylinder 215 . A pin 254 is inserted through the elongated hole 252 , and the pin 254 is fixed to the rectilinear cylinder 215 through a spring plate member 256 arranged between the biasing force transmission member 250 and the rectilinear cylinder 215 . .
The spring hooking plate member 256 is fixed to the rectilinear cylinder 215 .
A spring 260 is hooked between the spring hooking plate member 256 and the spring hooking portion 255 provided on the biasing force transmission member 250 . Spring 260 is a tension spring.
One end of the spring 260 is hooked on the spring hook plate member 256, and the other end of the spring 260 is hooked on the spring hook portion 255, so that the spring hook portion 255, that is, the biasing force transmission member 250 is shown in FIGS. Force in the direction of the arrow. As a result, the biasing force transmission member 250 is pulled toward the image side.

FIG. 8 is a partial view of the rectilinear cylinder 215 and the rotating cylinder 213 shown by the dotted line arranged outside the rectilinear cylinder 215 as seen from the radially outer peripheral side. A bearing 250 b and a bearing 215 b are arranged inside the cam groove 213 a on the inner surface of the rotary cylinder 213 .
When the biasing force transmission member 250 is pushed toward the image side as indicated by the arrow in the drawing, the bearing 250b fixed to the biasing force transmission member 250 is also pushed toward the image side, and the bearing 250b is pushed toward the image side of the cam groove 213a. and press the sides thereof.

On the other hand, a bearing 215b fixed to the rectilinear barrel 215 is in contact with the subject side surface of the cam groove 213a. As a result, both side surfaces of the cam groove 213a are pressed by the bearings 250b and 215b, respectively, so that play between the rotary barrel 213 and the rectilinear barrel 215, which is linearly moved by the rotation of the rotary barrel 213, is prevented. .

In this embodiment, the bearing 215b is a main bearing that drives the rectilinear cylinder 215 by rotating the rotary cylinder 213, and the bearing 250b fixed to the biasing force transmission member 250 is a bearing for removing backlash. Then, when the rotary barrel 213 rotates, the position of the main bearing 215b changes according to the zoom position and focus position.

FIG. 9 is a view showing a cam groove 213a' provided in a rotating cylinder 213' in a comparative embodiment. In the comparative form, the width of the cam groove 213a' is constant.
When the width of the cam groove 213a' is constant, if the position of the main bearing 215b changes depending on the zoom position or focus position, the relative positional relationship in the optical axis direction between the main bearing 215b and the looseness removing bearing 250b changes. .
For example, at position P1 in FIG. 9, the distance in the optical axis OA direction between the main bearing 215b and the backlash-removing bearing 250b is d1, but at position P2 in FIG. The distance in the optical axis OA direction between the bearing 250b is almost zero.

Then, when the positional relationship between the main bearing 215b and the backlash-removing bearing 250b changes depending on the zoom position and the focus position, the extension amount of the spring 260 also changes. Therefore, the force with which the looseness removing bearing 250b is pressed against the cam groove 213a changes. As a result, the user's sense of torque (operational feeling) changes, and the user may feel uncomfortable.

However, in the embodiment, the shape of the side surface of the cam groove 213a is made different between the object side (front side) and the image side (rear side), and as shown in FIG. Also, the positional relationship (for example, the distance d2 in the direction of the optical axis OA) between the main bearing 215b and the looseness removing bearing 250b is kept unchanged. Therefore, the amount of change in the force with which the backlash-removing bearing 250b is pressed against the cam groove 213a is small. Therefore, the user's sense of torque does not change, and the user can operate without feeling discomfort. In this case, the moving locus of the rectilinear barrel 215 with respect to the rotating barrel 213 is determined by the subject-side side surface of the cam groove 213a that is in contact with the main bearing 215b.

Further, generally, the torque is small in a region where the inclination angle of the cam groove 213a with respect to the circumferential direction is large, and the torque is large in a region where the inclination angle is small. Therefore, the shape of the cam surface contacting the backlash-removing bearing may be adjusted so that the spring force is strong in the area where the inclination angle of the cam groove 213a is large and the spring force is weak in the area where the inclination angle is small.

In the present embodiment, the main bearing 215b is in contact with the subject-side side surface of the cam groove 213a, and the backlash-removing bearing 250b is in contact with the image-side side surface of the cam groove 213a, but the present invention is not limited to this. For example, the main bearing may be brought into contact with both side surfaces of the cam groove, and the backlash bearing may be brought into contact with one side surface. As a result, since the main bearing can move while contacting both sides of the cam groove, the movement of the cylinder (lens) can be made more accurate, and since the backlash-removing bearing is in contact with one side, excessive restraint can be avoided. You can move it smoothly.

In addition, although a tension spring is used in the embodiment, a compression spring may be used.
In the embodiment, an example in which the rotating barrel 213 is arranged on the outer peripheral side of the rectilinear barrel 215 has been described, but the present invention is not limited to this. The rotating barrel 213 may be arranged on the inner peripheral side of the rectilinear barrel 215 .

(Third embodiment)
Next, the lens barrel 301 of the third embodiment will be described with reference to FIGS. 10-12. Like the lens barrel 1 of the first embodiment, the lens barrel 301 also has a lens side mount portion (not shown), and a body side mount portion (not shown) provided on the camera body (not shown). ) is an interchangeable lens barrel 301 that can be attached to and detached from. Note that a camera in which the body and the lens barrel are integrated may be used. The lens barrel 301 includes an inner barrel 310 and an outer barrel 350 that do not rotate relative to each other but move linearly.

FIG. 10 is a partial perspective view of the lens barrel 301 of the third embodiment, showing a state where the outer cylinder 350 is removed. FIG. 11 is a cross-sectional view taken along the line AA of FIG. 10, showing a state in which the outer cylinder 350 is arranged on the outer circumference of the inner cylinder 310 shown in FIG. 12 is a cross-sectional view along BB in FIG. 10, which is displaced in the circumferential direction from the cross-sectional view along AA in FIG.

(Inner cylinder 310)
Concave portions 311 extending in the optical axis direction are provided at three even circumferential locations on the outer periphery of the inner cylinder 310 . Wide width portions 311a having a wide circumferential width are provided at both ends of the concave portion 311 in the longitudinal direction. The number of positions where the concave portions 311 are provided may be two or less, or may be four or more. Also, it may be uneven.

(rectangular parallelepiped member 313)
Inside the portion (central portion) other than the wide portion 311a of the recess 311, two elongated rectangular parallelepiped members 313 are arranged along the longitudinal direction. A hole 313 a extending into the inside of the rectangular parallelepiped member 313 is provided in the side surface of one end of the rectangular parallelepiped member 313 in the longitudinal direction. A recess 313b is provided on the side surface of the rectangular parallelepiped member 313 at the other end in the longitudinal direction.
The two rectangular parallelepiped members 313 are linearly arranged in the recess 311 so that the surfaces provided with the respective holes 313a face each other.
One spring 315 is arranged through the hole 313 a of one rectangular parallelepiped member 313 and the hole 313 a of the other rectangular parallelepiped member 313 . The spring 315 is a compression spring, and both ends of the spring 315 are in contact with the bottoms of the holes 313a of the respective rectangular parallelepiped members 313, urging the two rectangular parallelepiped members 313 away from each other.
In addition, although the shape of the rectangular parallelepiped member 313 is described as a rectangular parallelepiped as an example, the shape is not limited to the rectangular parallelepiped. For example, it may be in the shape of a cylinder or a polygonal prism.

(Roller 320)
Rollers 320 are arranged on wide portions 311 a provided on both ends of the recess 311 in the longitudinal direction. The roller 320 is disc-shaped, and a shaft member 321 is inserted through the center of the roller 320 . A portion of the roller 320 is held within the recess 313 b of the rectangular parallelepiped member 313 .
In the wide portion 311a of the concave portion 311, slopes 312a are formed on both end surfaces in the optical axis direction on both sides in the circumferential direction sandwiching the portion where the roller 320 is arranged, as shown in FIG. The shaft member 321 of the roller 320 abuts against the slope 312a, and the position of the roller 320 in the radial direction is determined by this contact position.

(Outer cylinder 350)
The inner surface of the outer cylinder 350 is also formed with recesses 350a extending in the optical axis direction at three even locations in the circumferential direction.
The upper end of the roller 320 arranged in the recess 311 of the inner cylinder 310 is in contact with the inner surface of the recess 350 a of the outer cylinder 350 .
When the two rectangular parallelepiped members 313 are biased away from each other by the springs 315, the rollers 320 at both ends rotate and move away from each other, and the shaft members 321 climb the slopes 312a. Then, the position of the roller 320 moves from the inner cylinder 310 to the outer cylinder 350 side. That is, the two rectangular parallelepiped members 313 are urged in the optical axis direction by the springs 315, so that the rollers 320 come into contact with the concave portions 350a of the outer cylinder 350, and the radial play between the inner cylinder 310 and the outer cylinder 350 is eliminated. be able to.
The sets of two rollers 320 arranged at both ends in the optical axis direction are arranged at three even positions in the circumferential direction. When the spring force of the spring 315 and the inclination of the slope 312a are uniform at three locations in the circumferential direction, the outer cylinder 350 is evenly pressed outward at three locations in the circumferential direction, and the space between the outer cylinder 350 and the inner cylinder 310 is evenly pushed. radial play can be removed. It should be noted that the spring force of the spring 315 and the inclination of the slope 312a may be varied at three points in the circumferential direction.
In addition, although the example in which the inner cylinder 310 has the recessed part 311 and the outer cylinder 350 has the recessed part 350a was demonstrated in embodiment, it does not restrict to this. The recess 311 may be formed in the outer cylinder 350 and the recess 350 a may be formed in the inner cylinder 310 . As a result, the roller 320 rolls on the inclined surface 312a formed on the outer cylinder 350 toward the inner diameter side and comes into contact with the concave portion 350a of the inner cylinder 310 to eliminate backlash.

(Fourth embodiment)
Next, the lens barrel 401 of the fourth embodiment will be described with reference to FIGS. 13 and 14. FIG. Like the lens barrel 1 of the first embodiment, the lens barrel 401 also has a lens side mount portion (not shown), and a body side mount portion (not shown) provided on the camera body (not shown). ) is an interchangeable lens barrel 401 that can be attached to and detached from. Note that a camera in which the body and the lens barrel are integrated may be used. The lens barrel 401 includes an inner barrel 410 and an outer barrel 450 which do not rotate relative to each other but move linearly.
FIG. 13 is a partial perspective view of the lens barrel 401 of the fourth embodiment, showing a state where the outer cylinder 450 is removed. FIG. 14 is a cross-sectional view taken along line CC of FIG. 13, showing a state in which the outer cylinder 450 is arranged on the outer circumference of the inner cylinder 410 shown in FIG.

(Inner cylinder 410)
Concave portions 411 extending in the optical axis direction are provided at three even circumferential locations on the outer periphery of the inner cylinder 410 . Note that the number of recesses 411 may be two or less, or may be four or more. Also, they may be arranged unevenly. Conical portions 411 a are provided at both ends of the recess 411 in the longitudinal direction.

(Hexagonal prism member 413)
Two elongated hexagonal columnar members 413 are arranged along the longitudinal direction in a portion (central portion) of the concave portion 411 other than the conical portion 411a. A hole 413 a extending into the inside of the hexagonal columnar member 413 is provided in the side surface of one end of the hexagonal columnar member 413 in the longitudinal direction. The two hexagonal prism members 413 are linearly arranged in the recess 411 so that the surfaces provided with the respective holes 413a face each other. One spring 415 is arranged through the hole 413 a of one hexagonal column member 413 and the hole 413 a of the other hexagonal column member 413 . The spring 415 is a compression spring, and both ends of the spring 415 are in contact with the bottoms of the holes 413a of the respective hexagonal prism members 413, urging the two hexagonal prism members 413 away from each other. In addition, although the shape of the hexagonal prism member 413 is described as a hexagonal prism as an example, the shape is not limited to this. For example, it may be a cylinder or other polygonal cylinder.

(ball 420)
Balls 420 are arranged in conical portions 411 a provided on both longitudinal end sides of the concave portion 411 . The ball 420 is in contact with the surface of the hexagonal prism member 413 opposite to the side where the hole 413a is provided.
Also, the ball 420 is in contact with the slopes of the conical portions 411 a provided on both end sides of the recess 411 . The radial position of the ball 420 is determined by the contact position between the ball 420 and the slope of the conical portion 411a.

(Outer cylinder 450)
The inner surface of the outer cylinder 450 is also formed with recesses 450a extending in the optical axis direction at three even locations in the circumferential direction. The upper end of the ball 420 arranged in the recess 411 of the inner cylinder 410 is in contact with the inner surface of the recess 450 a of the outer cylinder 450 .
When the two hexagonal prism members 413 are biased away from each other by the springs 415, the balls 420 at both ends are rotationally moved away from each other and climb the slope of the conical portion 411a. Then, the position of the ball 420 moves from the inner cylinder 410 side to the outer cylinder 450 . In other words, when the two hexagonal prism members 413 are urged in the optical axis direction by the spring 415, the ball 420 climbs up the slope of the conical portion 411a and comes into contact with the concave portion 450a of the outer cylinder 450. It is possible to remove the play in the radial direction.
The sets of two balls 420 arranged at both ends in the optical axis direction are arranged at three even positions in the circumferential direction. When the spring force of the spring 415 and the inclination of the slope of the conical portion 411a are uniform at three locations in the circumferential direction, the outer cylinder 350 is evenly pressed outward at the three locations in the circumferential direction. It is possible to remove radial play between The spring force of the spring 415 and the inclination of the conical portion 411a may be varied at three points in the circumferential direction.
In addition, although the example in which the inner cylinder 410 has the recessed part 411 and the outer cylinder 450 has the recessed part 450a was demonstrated in embodiment, it does not restrict to this. The recess 411 may be formed in the outer cylinder 450 and the recess 450 a may be formed in the inner cylinder 410 . As a result, the ball 420 rolls toward the inner diameter side on the slope of the conical portion 411a formed in the outer cylinder 450 and comes into contact with the recessed portion 450a of the inner cylinder 410 to eliminate backlash.

Note that any combination may be used without being limited to the embodiments described above.

1: Lens barrel, 13: Rotating barrel, 13a: Circumferential groove, 13b: Helicoid groove, 14: Fixed barrel, 14a: Concave portion, 14b: Bearing, 15: Linear barrel, 15C: Threaded portion, 15a: Concave portion, 15b : bearing 15c: helicoid screw 16: first annular member 16a: convex portion 16b: bearing 16c: hole 17: spring 18: second annular member 18a: convex portion 18b: bearing 18c: Hole 18d: Spring 200: Structural portion 201: Lens barrel 213: Rotating barrel 213a: Cam groove 215: Linear barrel 215a: Groove 215b: Bearing 224: Connecting barrel 225: Drive shaft 250: biasing force transmission member, 250a: opening, 250b: bearing, 251: elongated hole, 252: elongated hole, 253: pin, 254: pin, 255: spring hook, 256: plate member, 260: spring, 301 : lens barrel 310: inner cylinder 311: concave portion 312a: slope 313: cuboid member 313a: hole 315: spring 320: roller 321: shaft member 350: outer cylinder 350a: concave portion 401 : Lens barrel 410: Inner cylinder 411: Concave portion 411a: Conical portion 413: Hexagonal prism member 413a: Hole 415: Spring 420: Ball 450: Outer cylinder 450a: Concave portion

Claims (11)

a first member having a first protrusion;
a second member having a second protrusion;
a third member disposed on one of the radially outer side or the inner side of the first member and having a groove that engages with the first protrusion and the second protrusion;
an elastic member arranged along the optical axis direction between the first member and the second member;
The second member is supported by the elastic member so as to be movable in the optical axis direction with respect to the first member, and the distance between the center of the first protrusion and the center of the second protrusion is variable,
The elastic member causes the first protrusion to contact one side surface of the groove and the other side surface of the groove, and the second protrusion to contact the other side surface of the groove. 2. The lens barrel according to claim 1 , wherein the second member is movable relative to the first member in the optical axis direction and does not move in the rotational direction. 3. The lens barrel according to claim 1, wherein the groove has a shape different from that of the one side surface and that of the other side surface. equipped with a lens,
4. The lens barrel according to claim 3 , wherein the lens moves in the optical axis direction as the first protrusion moves along the one side surface of the groove. 5. The lens barrel according to any one of claims 1 to 4 , wherein the third member and the first and second members are relatively rotatable about an optical axis. The lens barrel according to any one of claims 1 to 5 , wherein the first member is a fixed barrel or a rectilinear barrel movable in the optical axis direction. The lens according to any one of claims 1 to 6 , wherein the first protrusion and the second protrusion are arranged so as to at least partially overlap in a circumferential direction around the optical axis. lens barrel. The lens barrel according to any one of Claims 1 to 7 , wherein the first projection and the second projection have bearings. The lens barrel according to any one of Claims 1 to 8 , wherein the groove is any one of a circumferential groove, a helicoid groove, and a cam groove. 10. The lens barrel according to claim 9 , wherein the groove is provided so that the interval in the optical axis direction between the first protrusion and the second protrusion is constant. The lens barrel according to any one of Claims 1 to 10 , wherein the second member is an annular member arranged at an end of the first member in the optical axis direction.

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