JPH0933794A - Lens barrel - Google Patents

Abstract

(57) Abstract: To increase the strength of a fixed barrel of a lens barrel that moves a lens manually and by a motor. A fixed barrel is driven by driving a focus motor.
The second drive shaft 80 arranged on the inner peripheral side of the lens barrel rotates, and the rotation of the second drive shaft 80 rotates the cam barrel 20 to rotate the lens L.
4 moves in the optical axis direction. A second gear 85 is attached to the second drive shaft 80. A notch 18 is formed in the fixed barrel 10 existing between the manual focus operation ring 35 and the second gear 85, and through the notch 18,
Segment gear 3 formed on the inner peripheral surface of the operating ring 35
6 and the second gear 85 are engaged. Since the notch 18 of the fixed cylinder 10 only needs to be cut out only at the position where the second gear 85 is located, the size thereof can be reduced,
The strength of the fixed barrel 10 can be increased.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lens barrel for moving a lens in the optical axis direction manually and by a motor.

[0002]

2. Description of the Related Art As a conventional lens barrel, for example, there is one shown in FIG. This lens barrel includes a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, a fifth lens L5, and a sixth lens L6.
And the fixed barrel 10 in which these lenses are arranged on the inner peripheral side.
a and a fourth lens retaining ring 25 for retaining the fourth lens L4
A cam barrel 20 rotatably arranged on the inner circumference side of the fixed barrel 10a around the optical axis, and a manual focus operation ring 35a rotatably arranged on the outer circumference side of the cam barrel 20 around the optical axis. , A first drive shaft 70 that is rotated by the drive of a focus motor in the camera body, a first gear 75 provided at the end of the first drive shaft 70 on the subject side, and a first drive shaft 70 that is disposed on the subject side of the first drive shaft. Second drive shaft 80, and second drive shaft 80
Second gear 85 attached to the camera body side end of the second gear 85 engaged with the first gear 75, and a third gear 85 attached to the subject side end of the second drive shaft 80 for rotating the cam barrel 20 around the optical axis. And a gear 87.

The first lens L1, excluding the fourth lens L4,
The second lens L2, the third lens L3, the fifth lens L5, and the sixth lens L6 are fixed to the inner peripheral side of the fixed barrel 10a. Fourth lens retaining ring 25 for retaining the fourth lens L4
Are arranged on the inner peripheral side of the fixed barrel 10a so as to be movable in the optical axis direction. On the outer circumference of the fourth lens holding ring 25, a straight guide pin 32 and a cam pin 31 are provided so as to project.

The cam barrel 20 is connected to the manual focus operating ring 35a and the connecting pin 36 so that the cam barrel 20 can rotate around the optical axis as the manual focus operating ring 35a rotates.
a. A segment gear 24 that extends in the direction around the optical axis and engages with the third gear 87 is formed on the camera body side on the inner peripheral side of the cam barrel 20, and the optical axis is centered on the subject side of the segment gear 24. The cam groove 21 is formed in a spiral shape.

The fixed barrel 10a extends in a direction parallel to the optical axis, and the straight groove 12 into which the tip end of the straight guide pin 32 is slidably fitted, and the cam pin 31 also extends in the direction parallel to the optical axis. And an escape hole 11 through which is inserted. The tip of the cam pin 31 protruding from the fourth lens holding ring 25 is inserted into the cam barrel 20 via the escape hole 11 of the fixed barrel 10a.
It is slidably fitted in the cam groove 21.

In this lens barrel, in the manual focus mode, the photographer rotates the manual focus operating ring 35a around the optical axis. This operation ring 3
With the rotation of 5a, the operating ring 35a and the connecting pin 36
The cam barrel 20 connected by a also rotates around the optical axis.
When the cam barrel 20 rotates around the optical axis, the cam pin 31 fitted in the cam groove 21 of the cam barrel 20 moves in the optical axis direction, and the fourth lens retaining ring 25 and the fourth lens L4 move in the optical axis direction. Move to.

In the auto focus mode, the focus motor in the camera body is driven to drive the first
The drive shaft 70, the second drive shaft 80, and the third gear 87 attached to the second drive shaft 80 rotate, and the cam barrel 20 engaged with the third gear 87 rotates about the optical axis. As a result, as in the manual focus mode, the fourth
The lens holding ring 25 and the fourth lens L4 move in the optical axis direction.

[0008]

However, in such a conventional technique, for example, when the manual focus operating ring 35a rotates 180 ° about the optical axis, the operating ring 35a and the cam barrel 20 are connected. Since the connecting pin 36a to be rotated is also 180 degrees about the optical axis, the fixed cylinder 10a existing between the operation ring 35a and the cam cylinder 20 is
Connecting pin 36 with 180 ° spread around the optical axis
It is necessary to form a notch 18a through which a is inserted. For this reason, the conventional technique has a problem that the strength of the fixed cylinder is reduced.

The present invention has been made by paying attention to such a conventional problem, and in the lens barrel for moving the lens in the optical axis direction manually and by the motor, the strength of the fixed barrel can be increased. An object is to provide a lens barrel.

[0010]

[Means for Solving the Problems] A lens barrel for achieving the above-mentioned object has a cylindrical shape with an optical axis as a center, and has a notch penetrating from its inner peripheral surface to its outer peripheral surface. A fixed barrel, a drive shaft disposed on the inner peripheral side of the fixed barrel and rotated by the drive of the motor, and a inner peripheral side of the fixed barrel, and rotating the drive shaft to move the lens in the optical axis direction. A lens moving mechanism for moving, an operating ring rotatably arranged around the optical axis at a position on the outer peripheral side of the fixed barrel and covering the notch, and a part of the notch of the fixed barrel. It comes into contact with the inner peripheral surface of the operation ring, and rotates with the rotation of the operation ring around an axis separated by a certain distance from the optical axis,
And a power transmission member that rotates the drive shaft.

Here, in the lens barrel, the power transmission member is a gear attached to the drive shaft, and a gear engaging with the gear is formed on an inner peripheral surface of the operation ring. It may be In this case, one or more gears may be interposed between the gear attached to the drive shaft and the gear formed on the inner peripheral surface of the operation ring.

In the lens barrel, a part of the power transmission member faces the notch of the fixed barrel and contacts the inner peripheral surface of the operating ring, and as the operating ring rotates, A first roller that rotates about an axis that is away from the optical axis by a certain distance, a second roller that rotates by contacting the outer peripheral surface of the first roller, and a second roller that shares the rotation axis of the second roller
It may have a first gear that rotates by the rotation of the roller and a second gear that is attached to the drive shaft and that engages with the first gear.

In the above lens barrel, the lens moving mechanism for moving the lens in the optical axis direction by the rotation of the drive shaft is attached to the drive shaft in one embodiment of the present invention. The third gear 87, the cam barrel 20 that rotates around the optical axis by the rotation of the third gear, the lens holding ring 25 that holds the lens, and the lens holding ring 25 that projects from the lens holding ring 25 and that rotates when the cam barrel 20 rotates. It is configured to have a cam pin 31 and a linear guide pin 32 that move in the optical axis direction.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A lens barrel as a first embodiment according to the present invention will be described below with reference to FIGS. 1 and 2. The lens barrel as one embodiment includes a first lens L1, a second lens L2, a third lens L3, and a fourth lens L3.
A lens L4, a fifth lens L5, a sixth lens L6,
A fixed barrel 10 in which these lenses are arranged on the inner peripheral side,
A fourth lens retaining ring 25 that holds the fourth lens L4, a cam barrel 20 that is rotatably arranged around the optical axis on the inner peripheral side of the fixed barrel 10, and an outer peripheral side of the cam barrel 20 around the optical axis. A manual focus operation ring 35 rotatably arranged,
A cover cylinder 50 that covers the outer periphery of the fixed cylinder 10 on the camera body side.
A mount ring 55 fixed to the camera body side of the fixed barrel 10, a diaphragm mechanism 60 for changing the aperture diameter, and a first drive shaft 70 arranged in the fixed barrel 10 and rotated by driving a focus motor in the camera body. A first gear 75 provided at the subject side end of the first drive shaft 70, a second drive shaft 80 disposed on the subject side of the first drive shaft 70, and a second drive shaft 8
No. 0, which is attached to the end of the camera body on the side of the camera body and engages with the first gear 75, and the second drive shaft 80, which is attached to the end of the subject on the object side to rotate the cam barrel 20 around the optical axis. The third gear 87 and the main plate 40 that rotatably supports the first drive shaft 70 and the second drive shaft 80 are provided.

The fixed barrel 10 has a cylindrical front large-diameter cylindrical portion 13 centered on the optical axis, a front small-diameter cylindrical portion 14 formed on the inner peripheral side of the front large-diameter cylindrical portion 13, and a front large-diameter cylindrical portion. A rear small-diameter cylindrical portion 16 formed on the camera body side of the portion 13, a rear large-diameter cylindrical portion 17 formed on the camera main body side of the rear small-diameter cylindrical portion 16, and a portion perpendicular to the optical axis. It has a coupling part 15 which has a surface and couples the front large-diameter cylindrical part 13 and the rear small-diameter cylindrical part 16. The front large-diameter cylindrical portion 13 and the front small-diameter cylindrical portion 14 are joined together at their subject-side portions.

The respective lenses are, from the subject side to the camera body side, a first lens L1, a second lens L2, and a third lens L.
3, 4th lens L4, 5th lens L5, 6th lens L6
Are arranged in this order. The first lens L1, the second lens L2, the third lens L3, the fifth lens L5, and the sixth lens L6, excluding the fourth lens L4, are fixed to the inner peripheral side of the front small-diameter cylindrical portion 14 of the fixed cylinder 10. There is. The fourth lens retaining ring 25 that retains the fourth lens L4 is disposed on the inner peripheral side of the front small-diameter tubular portion 14 of the fixed barrel 10 so as to be movable in the optical axis direction.
The straight guide pin 3 is provided on the outer periphery of the fourth lens retaining ring 25.
2 and the cam pin 31 are projected.

The cam barrel 20 is arranged on the inner peripheral side of the front large-diameter cylindrical portion 13 of the fixed barrel 10 and on the outer peripheral side of the front small-diameter cylindrical portion 14 so as to be rotatable around the optical axis. On the inner peripheral surface of the cam barrel 20, a peripheral groove 23 extending in the optical axis rotation direction is formed on the subject side, and on the camera body side, a segment gear extending in the optical axis rotation direction and engaging with the third gear 87. 24 is formed,
A cam groove 21 formed in a spiral shape around the optical axis is formed between the circumferential groove 23 and the segment gear 24.

The front small-diameter cylindrical portion 14 of the fixed barrel 10 extends in the direction parallel to the optical axis, and the straight-moving groove 12 into which the tip end of the straight-moving guide pin 32 is slidably fitted is also parallel to the optical axis. And an escape hole 11 extending in the direction and through which the cam pin 31 is inserted. On the outer peripheral side of the front small-diameter cylindrical portion 14, an optical axis direction movement restricting pin 33 is provided so that its tip end slidably fits into the peripheral groove 23 of the cam cylinder 20. The tip of the cam pin 31 protruding from the fourth lens retaining ring 25 is
It is slidably fitted into the cam groove 21 of the cam barrel 20 through the escape hole 11 of the front small diameter tubular portion 14. The straight guide pin 32 is slidably fitted in the straight groove 12 of the front small-diameter cylindrical portion 14.

As shown in FIGS. 1 and 2, a notch 18 penetrating from the inner peripheral side to the outer peripheral side is formed on the camera body side of the front large-diameter cylindrical portion 13 of the fixed barrel 10. The manual focus operating ring 35 is provided on the front large-diameter cylindrical portion 1 of the fixed barrel 10.
It is rotatably arranged around the optical axis at a position on the outer peripheral side of 3 and covering the notch 18 of the front large-diameter cylindrical portion 13.
A segment gear 36 that engages with the second gear 85 is formed on the inner peripheral surface of the manual focus operation ring 35.

A base plate 40 is fixed to the camera body side of the coupling portion 15 of the fixed barrel 10 with screws 44 (shown in FIG. 2). A mount ring 55 is fixed by a screw 58 to the camera body side of the rear large-diameter cylindrical portion 17 of the fixed barrel 10. A first drive shaft 70 is arranged on the outer peripheral side of the rear small-diameter cylindrical portion 16 in parallel with the optical axis. A shaft-supported portion 71 supported by the base plate 40 is formed at an end of the first drive shaft 70 on the object side, and a first gear 75 is attached slightly to the camera body side. At the end of the first drive shaft 70 on the camera body side, a coupling portion 72 that penetrates the mount ring 55 and is connected to the drive shaft that is connected to the focus motor in the camera body is formed.

A second drive shaft 80 is arranged between the inner peripheral side of the front large-diameter cylindrical portion 13 of the fixed cylinder 10 and the front small-diameter cylindrical portion 14 in parallel with the optical axis. The end portion of the second drive shaft 80 on the camera body side penetrates the coupling portion 15 of the fixed barrel 10 and the base plate 40. A segment formed on the inner peripheral surface of the manual focus operation ring 35 at the end of the second drive shaft 80 on the camera body side, a part of which faces the notch 18 of the front large-diameter cylindrical portion 13 of the fixed barrel 10. A second gear 85 that engages with the gear 36 and the first gear 75 is attached. The subject side end of the second drive shaft 80 is rotatably supported by the fixed barrel 10 via a bush 88. A third gear 87 that engages with the segment gear 24 of the cam barrel 20 is attached to the side of the camera body that is slightly above the bush 88 of the second drive shaft 80.

The diaphragm mechanism 60 includes a diaphragm operating ring 61 arranged on the outer periphery of the rear large-diameter cylindrical portion 17 of the fixed barrel 10 so as to be rotatable about the optical axis, and the rotation of the diaphragm operating ring 61 rotates around the optical axis. A first rotating plate 62 that rotates around the optical axis, a second rotating plate 64 that rotates around the optical axis, a rotation amount changing plate 63 that changes the amount of rotation of the second rotating plate 64 with respect to the amount of rotation of the first rotating plate 62, A plurality of diaphragm blades 65, 65, ... Arranged in an annular shape around the optical axis along the second rotary plate 64, one end 67c extending to the mount ring 55, and the other end 67b engaging the second rotary plate 64. , And an automatic diaphragm interlocking lever 67 rotatable about an axis 67a perpendicular to the optical axis.

The plurality of diaphragm blades 65, 65, ..., The second rotary plate 64, the rotation amount changing plate 63, and the first rotary plate 62 are arranged in this order from the subject side in the camera body side of the connecting portion 15 of the fixed barrel 10. Is attached to. In addition, this diaphragm mechanism 60
Since this is a well-known mechanism and is not directly related to the content of the invention, a description of its detailed configuration and operation of each component will be omitted.

Next, the operation of the above lens barrel will be described. When the manual focus operation ring 35 is rotated around the optical axis in the manual focus mode,
Through the notch 18 of the front large-diameter cylindrical portion 13 of the fixed cylinder 10,
The second gear 85 engaged with the segment gear 36 formed on the inner peripheral surface of the operation ring 35 rotates. When the second gear 85 rotates, the second drive shaft 80 to which the second gear 85 is attached and the third gear 87 attached to the second drive shaft 80 also rotate and engage with the third gear 87. The rotating cam barrel 20 rotates around the optical axis. Cam barrel 20
Is rotated about the optical axis, the cam pin 31 fitted into the cam groove 21 formed in a spiral shape around the optical axis, and the fourth cam pin 31 protruding from the cam pin 31.
The lens holding ring 25 tries to move in the optical axis direction while rotating around the optical axis. However, the fourth lens holding ring 2
Since the linear guide pin 32 protruding from the optical axis 5 is fitted in the linear groove 12 of the fixed barrel 10 extending in the direction parallel to the optical axis, the fourth lens retaining ring 25 is provided around the optical axis. It moves in the optical axis direction without rotating. As a result, the fourth lens L4 held by the fourth lens holding ring 25 also moves in the optical axis direction.

In the auto focus mode, the focus motor in the camera body drives to drive the first drive shaft 7
0 and the first gear 7 attached to the first drive shaft 70
When 5 rotates, the second gear engaged with the first gear 75
The gear 85, the second drive shaft 80 to which the second gear 85 is attached, and the third gear 87 attached to the second drive shaft 80 rotate. As a result, the cam barrel 20 engaged with the third gear 87 rotates around the optical axis, and the fourth lens L4 moves in the optical axis direction as in the manual focus mode.

By the way, in the embodiment of the present invention, when the manual focusing operation ring 35 is rotated to rotate the cam barrel 20 around the optical axis, the cam barrel 20 is not directly rotated by the operating ring 35, but the autofocus is performed. At this time, the cam cylinder 20 is indirectly rotated by rotating the second gear 85, which is a component for rotating the cam cylinder 20 around the optical axis. Therefore, the manual focus operation ring 35
And the second gear 85 that is directly rotated by the operating ring 35.
In the front large-diameter cylindrical portion 13 of the fixed cylinder 10 arranged between and, it suffices to cut out only where the second gear 85 exists. Therefore, the size of the notch 18 of the front large-diameter cylindrical portion 13 of the fixed barrel 10 can be reduced, and the strength of the fixed barrel 10 can be increased.

In the above embodiment, the second gear 85 is directly rotated by the manual focus operating ring 35. However, due to the arrangement of the second gear 85 or the manual focus operating ring 35 and the cam barrel 20. One or more gears may be interposed between the segment gear 36 of the manual focus operation ring 35 and the second gear 85 in order to adjust the rotation ratio. Further, in the above embodiment, the second gear 85 is rotated by the manual focus operation ring 35. However, for example, when the third gear 87 is located on the outer peripheral side of the cam barrel 20, the third gear 87 is rotated. May be rotated directly by the manual focus operation ring 35.

Further, in the above-described first embodiment, the segment gear 3 is provided on the inner peripheral surface of the manual focus operation ring 35.
6 is formed, the present invention can be implemented without forming the segment gear 36. Hereinafter, this embodiment will be described as a second embodiment with reference to FIG.

As shown in FIG. 3, the inner peripheral surface of the manual focus operating ring 35c in the second embodiment is smooth and has no gears. A part of the lens barrel in this embodiment faces the notch 18 of the fixed barrel 10 and comes into contact with the smooth inner peripheral surface of the manual focus operation ring 35c, and is fixed from the optical axis as the operation ring 35c rotates. An operation ring power transmission first roller 90 that rotates about a shaft 91 that is separated by a distance, an operation ring power transmission second roller 92 that rotates by contacting the outer peripheral surface of the first roller 90, and this second roller. It has an operating ring power transmission gear (first gear in claim 3) 94 that shares the rotation shaft 93 of 92, engages with the second gear 85, and rotates by the rotation of the second roller 92.

In the manual focus mode, the rotation of the manual focus operation ring 35c rotates the first roller 90, and this rotation causes the second roller 92 and the operation ring power transmission gear 94 to rotate. By the rotation of the operation ring power transmission gear 94, the second gear 85 rotates, and the cam barrel 20 rotates around the optical axis as in the first embodiment.

As described above, even if the segment gear is not formed on the inner peripheral surface of the manual focus operation ring 35c,
By using the roller 90 in contact with the inner peripheral surface of the operation ring 35c, the same effect as that of the first embodiment can be obtained.

In each of the above embodiments, the present invention is applied to the case where the lens is moved during autofocus and manual focus.
The present invention is not limited to this, and it goes without saying that the present invention may be applied when the zoom lens is manually moved and when the zoom lens is moved by the motor. In the above embodiment, the motor for moving the lens is provided in the camera body, but the motor may be provided in the lens barrel.

[0033]

According to the present invention, the operation ring that is directly rotated is not the cam barrel that rotates about the optical axis, but
Since it is a power transmission member that rotates about an axis that is separated from the optical axis by a certain distance, it is sufficient to cut out only the portion where the power transmission member is present in the fixed cylinder that exists between the operation ring and the power transmission member. Therefore, the notch formed in the fixed barrel can be reduced, and the strength of the fixed barrel can be increased.

[Brief description of drawings]

FIG. 1 is a sectional view of a lens barrel as a first embodiment according to the present invention.

FIG. 2 is a sectional view taken along line II-II in FIG.

FIG. 3 is a sectional view of an essential part of a lens barrel as a second embodiment according to the present invention.

FIG. 4 is a sectional view of a conventional lens barrel.

[Explanation of symbols]

10 ... Fixed tube, 12 ... Straight groove, 13 ... Large-diameter cylindrical portion on front side, 1
4 ... Front small-diameter tubular portion, 15 ... Coupling portion, 16 ... Rear small-diameter tubular portion, 17 ... Rear large-diameter tubular portion, 18 ... Notch, 20 ... Cam barrel, 21 ... Cam groove, 24 ... Segment of cam barrel Gears, 2
5 ... 4th lens holding ring, 31 ... Cam pin, 32 ... Straight guide pin, 35, 35a, 35c ... Manual focus operating ring, 36 ... Segment gear of manual focus operating ring, 50 ... Cover cylinder, 55 ... Mount ring, 60 ... throttle mechanism, 70 ... first drive shaft, 75 ... first gear, 80 ... second drive shaft, 85 ... second gear, 87 ... third gear, 90 ... operating ring power transmission first roller, 92 ... operation Ring power transmission second roller, 94 ... Operation ring power transmission gear.

Claims (3)

[Claims] 1. A lens barrel for moving a lens in the direction of an optical axis manually and by a motor, which has a cylindrical shape centered on the optical axis, and has a notch penetrating from its inner peripheral surface to its outer peripheral surface. A fixed barrel, a drive shaft arranged on the inner peripheral side of the fixed barrel and rotated by the drive of the motor, and a drive shaft arranged on the inner peripheral side of the fixed barrel, and the lens is rotated along the optical axis by rotation of the drive shaft. A lens moving mechanism for moving in a direction, and at a position on the outer peripheral side of the fixed cylinder that can cover the notch,
An operation ring rotatably arranged around an optical axis, a part of which faces the notch of the fixed cylinder and comes into contact with the inner peripheral surface of the operation ring, and rotates with the rotation of the operation ring. And a power transmission member for rotating the drive shaft, the lens barrel. 2. The lens barrel according to claim 1, wherein the power transmission member is a gear attached to the drive shaft, and a gear engaging with the gear is provided on an inner peripheral surface of the operation ring. A lens barrel characterized by being formed. 3. The lens barrel according to claim 1, wherein a part of the power transmission member faces the notch of the fixed barrel and comes into contact with an inner peripheral surface of the operating ring, thereby rotating the operating ring. Accordingly, the first roller that rotates about an axis that is separated from the optical axis by a certain distance, the second roller that rotates by contacting the outer peripheral surface of the first roller, and the rotation axis of the second roller are shared. ,
A lens barrel comprising: a first gear that is rotated by rotation of the second roller; and a second gear that is attached to the drive shaft and that engages with the first gear.