JP2017026809A - Lens-barrel and camera - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lens-barrel and a camera which are resistant to drop impact.SOLUTION: A lens-barrel 1 includes: a first barrel 24 having a first protrusion 32 and a second protrusion 30 extending in a radial direction; a first cam groove 42, which holds a lens L1 directly or indirectly and is engaged with the first protrusion 32; a second cam groove 43 capable of containing the second protrusion 30; and a second barrel 40, which is driven in the direction of the optical axis of the lense L1 via the first protrusion 32 by rotation around the optical axis, the second protrusion 30 being located outside the second cam groove 43 when the first protrusion 32 is at one end of the first cam groove 42.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a lens barrel and a camera.

  Conventionally, when a lens barrel drops from the tip and collides with the ground or the like, the impact portion may deform the contact portion of the cam groove with the cam pin, resulting in a poor zoom operation. In order to solve this problem, there is a lens barrel in which two cam grooves are provided such that cam pins that move inside draw the same locus (see Patent Document 1).

JP 2003-43331 A

The present invention provides a lens barrel, a first cylinder provided with a first protrusion and a second protrusion extending in the radial direction, and a first cam that holds the lens directly or indirectly and engages the first protrusion. A groove and a second cam groove in which the second protrusion can be positioned are provided, and driven in the optical axis direction through the first protrusion by rotation about the optical axis of the lens. And the second projection is located outside the second cam groove when the first projection is located at one end of the first cam groove.
In addition, the camera of the present invention is configured to include the lens barrel.

It is a schematic side view of the lens barrel of this embodiment, and shows a wide state. It is a schematic side view of the lens barrel of this embodiment, and shows a middle state between a wide state and a tele state. It is a side view which shows the schematic structure of the lens barrel of this embodiment, and shows a tele state. FIG. 4 is a development view of a wide state of the first lens moving cylinder and the front fixed cylinder. The development view of the middle state of the 1st lens moving cylinder and the front fixed cylinder is shown. The development view of the tele state of the first lens moving cylinder and the front fixed cylinder is shown. It is an enlarged view around the 2nd pin in the state of a middle and the state of tele. It is an enlarged view of the part A in FIG. Fixing ring is an exploded perspective view of the middle solid Teitsutsu and the rear fixed cylinder.

  Hereinafter, embodiments will be described with reference to the drawings. FIG. 1 is a schematic side view of the lens barrel 1 of the present embodiment, showing a wide (wide angle) state. FIG. 2 is a schematic side view of the lens barrel 1 of the present embodiment, showing a middle state between a wide state and a tele (telephoto) state. FIG. 3 is a side view showing a schematic configuration of the lens barrel 1 of the present embodiment, and shows a tele state.

  The lens barrel 1 of the present embodiment is an interchangeable lens barrel 1 that can be attached to and detached from a camera body 2 indicated by a dotted line in FIG. The lens barrel 1 of the present embodiment is a lens barrel that can be attached to and detached from the camera body, but is not limited thereto, and may be a lens barrel that is integral with the camera body.

The lens barrel 1 includes a first lens group L1, a second lens group L2, a third lens group L3, and a fourth lens group L4 that are arranged in order from the subject side.
Further, the lens barrel 1 includes a lens-side mount portion 11, a rear fixed tube 27, an intermediate fixed tube 26, a front fixed tube 24, a first cam tube 22, a second cam tube 23, a first lens moving tube 40, a first lens tube 1. The moving frame 51, the second moving frame 52, the third moving frame 53, the fourth moving frame 54, the focus ring 61, the zoom operation ring 20, and the zoom interlocking key 21 are provided.
However, the configuration of the lens barrel 1 is not limited to this, and the number of fixed barrels, cam barrels, moving frames, and the arrangement described below may be different from the present embodiment.

The lens side mount portion 11 is a bayonet lens side mount portion that can be attached to and detached from a lens side mount portion (not shown) of the camera body 2. However, the attachment / detachment structure of the lens barrel 1 and the camera body 2 is not limited to the bayonet lens side mount.
The camera body 2 is provided with an image pickup device (not shown), and a subject image formed by the lens groups L1 to L4 of the lens barrel 1 is formed on the image pickup surface of the image pickup device.

The rear fixed cylinder 27 is fixed to the lens side mount portion 11, the middle fixed cylinder 26 is fixed to the rear fixed cylinder 27, and the front fixed cylinder 24 is fixed to the middle fixed cylinder 26.
A fixing method among the rear fixed cylinder 27, the middle fixed cylinder 26, and the front fixed cylinder 24 will be described later.

The first cam cylinder 22 is rotatably disposed on the inner diameter side of the front fixed cylinder 24. The engagement relationship between the first cam cylinder 22, the front fixed cylinder 24, and the first lens moving cylinder 40 will also be described later.
The second cam cylinder 23 is rotatably disposed on the outer diameter side of the rear fixed cylinder 27.

  The first lens moving cylinder 40 is disposed on the outer diameter side of the front end of the front fixed cylinder 24 so as to be movable in the direction of the optical axis OA.

  The first moving frame 51 is held at the tip of the first lens moving cylinder 40. The second moving frame 52 is disposed on the inner diameter side of the first cam cylinder 22 so as to be movable in the direction of the optical axis OA. The third moving frame 53 is disposed on the inner diameter side of the rear fixed cylinder 27 and is driven by the rotation of the second cam cylinder 23. The fourth moving frame 54 is disposed on the inner diameter side of the rear fixed cylinder 27 so as to be movable in the direction of the optical axis OA.

The focus ring 61 is rotatably attached to the outer diameter side of the front fixed cylinder 24 and is connected to the second moving frame 52 by a connection key (not shown) so that the rotation operation is transmitted.
When the focus ring 61 is rotated, the first cam cylinder 22 is rotated. A focusing operation is performed by this rotation.

The zoom operation ring 20 is disposed on the outer diameter side of the second cam cylinder 23.
The zoom interlocking key 21 is attached to the zoom operation ring 20 and engages the first cam cylinder 22 and the second cam cylinder 23.

When the zoom operation ring 20 is manually rotated, the second cam cylinder 23 is rotated via the zoom interlocking key 21, and the first cam cylinder 22 is rotated accordingly.
By this rotation, the first lens moving barrel 40, the first moving frame 51, the second moving frame 52, the third moving frame 53, and the fourth moving frame 54 move straight in the direction of the optical axis OA, and a zooming operation is performed.

  As shown in FIG. 1, the first lens group extends most in the wide state, extends most in the middle state as shown in FIG. 2, and extends more in the tele state than in the middle state as shown in FIG. It becomes a state that is carried in rather than a wide state.

FIG. 4 is a development view of the first lens moving cylinder 40 and the front fixed cylinder 24 in a wide state. FIG. 5 shows a developed view of the middle state of the first lens moving cylinder 40 and the front fixed cylinder 24. FIG. 6 is a development view of the telephoto state of the first lens moving cylinder 40 and the front fixed cylinder 24.
4 to 6, an inner rectilinear groove 41, a first inner cam groove 42, a second inner cam groove 43, and a first group rectilinear pin 31 installed in a first lens moving cylinder 40 to be described later in each state. The positional relationship between the first group cam pin 32 and the second pin 30 is also shown.

  The front fixed cylinder 24 is provided with a circumferential groove 25 and a first group rectilinear pin 31 provided so as to extend in the circumferential direction around the optical axis OA. The circumferential groove 25 and the first group rectilinear pins 31 are provided equally three in the circumferential direction.

  The first lens moving barrel 40 is provided with three inner straight grooves 41, first inner cam grooves 42, and second inner cam grooves 43 equally in the circumferential direction.

  The inner rectilinear groove 41 extends in a direction along the optical axis OA, and the movement of the first lens moving barrel 40 in the circumferential direction is restricted by inserting the first group rectilinear pin 31 attached to the front fixed barrel 24. ing.

  The first inner cam groove 42 is a cam groove whose inclination (pressure angle) θ with respect to the circumferential direction around the optical axis OA varies depending on the position, and the first group cam pin 32 attached to the first cam cylinder 22 is inserted therein.

The first group cam pin 32 attached to the first cam cylinder 22 transmits the rotation of the first cam cylinder 22 to the first lens moving cylinder 40, and the second pin 30 restricts the movement in the optical axis OA direction.
The first cam cylinder 22 is provided with a cam groove (not shown) for driving the second lens unit L2.

  The second inner cam groove 43 is provided on the camera body side (imaging surface side) of the first inner cam groove 42 in the direction of the optical axis OA, and the locus of movement of the second pin that moves inside is the first inner cam groove. It is formed so as to be the same as the trajectory of movement of the first group cam pin 32 moving in the 42. That is, the second inner cam groove 43 and the first inner cam groove 42 are provided so as to be parallel to each other at a constant interval, and have the same curve.

The difference between the second inner cam groove 43 and the first inner cam groove 42 is that the length is different, and the second inner cam groove 43 is shorter than the first inner cam groove 42.
That is, as compared with the first inner cam groove 42, the second inner cam groove 43 is cut halfway along the optical axis OA direction camera body side (imaging surface side). The second inner cam groove 43 passes through the end surface 40a of the first lens moving barrel 40 on the optical axis OA camera body side (imaging surface side).
Thus, since the second inner cam groove 43 is shorter than the first inner cam groove 42, the second pin 30 is located outside the second inner cam groove 43 when the lens barrel 1 is in the wide state. That is, when the lens barrel 1 is operated from the middle state to the wide state, the second pin 30 passes through the end surface 40a from the inside of the second inner cam groove 43, and the second inner cam groove 43 has a camera. It moves to the outside on the body side (imaging surface side).

On the other hand, the second pin 30 is located in the second inner cam groove 43 in the middle state of FIG. 2 and the tele state of FIG.
FIG. 7 is an enlarged view around the second pin 30 in the middle state and the tele state. The second pin 30, the first cam barrel 22, the front fixed barrel 24, and the first lens moving barrel 40 are shown. It shows.
As illustrated, the second pin 30 includes a fixed portion 30d, a first portion 30a extending from the fixed portion 30d, a second portion 30b, and a small diameter portion 30c provided therebetween. The diameter decreases in the order of the first portion 30a, the second portion 30b, and the small diameter portion 30c.

A fixing portion 30 d of the second pin 30 is fixed to the first cam cylinder 22.
The first portion 30 a of the second pin 30 is engaged with a circumferential groove 25 provided in the front fixed cylinder 24, thereby restricting movement of the first cam cylinder 22 in the optical axis direction.
The outer diameter side of the small diameter portion 30 c of the second pin 30 and the second portion 30 b protrude from the circumferential groove 25.

  As described above, the first group cam pin 32 attached to the first cam cylinder 22 is inserted into the first inner cam groove 42 of the first lens moving cylinder 40. When the first cam barrel 22 rotates, the rotation is transmitted to the first lens moving barrel 40 by the first group cam pin 32, and the first lens moving barrel 40 moves along the first inner cam groove 42 in the direction of the optical axis OA. To do.

  As shown in FIG. 1, at the wide end, the first group cam pin 32 is located in the first inner cam groove 42. However. The second pin 30 is not located in the second inner cam groove 43. That is, the second pin 30 is located outside the second inner cam groove 43.

  When the first lens moving cylinder 40 is moved from the wide end to the tele side by zooming, the second portion 30b of the second pin 30 enters the second inner cam groove 43 as shown in FIGS.

When the second portion 30b of the second pin 30 is in the second inner cam groove 43, the second pin 30 is aligned with the optical axis OA of the second portion 30b of the second pin 30, as shown in FIG. The center 43b in the direction is attached to the first cam cylinder 22 so as to be offset from the center 43a in the direction along the optical axis OA of the second inner cam groove 43 toward the subject.
Therefore, when the second portion 30b of the second pin 30 is in the second inner cam groove 43, the camera body side is closer to the distance d between the subject-side end surface 43c of the second inner cam groove 43 and the second portion 30b. (Image pickup surface side) The distance D between the end surface 43d and the second portion 30b is wide.

  Next, a method of fixing the middle fixed cylinder 26 and the rear fixed cylinder 27 in the present embodiment will be described. FIG. 8 is an enlarged view of a portion A in FIG. FIG. 9 is an exploded perspective view of the fixing ring 100, the middle fixing cylinder 26 and the rear fixing cylinder 27.

The front end side of the rear fixed cylinder 27 has an enlarged inner diameter portion 27c having an inner diameter larger than that of other portions. Since the enlarged inner diameter portion 27c and other portions have different diameters, a side surface 27b facing the subject is formed at the boundary.
Further, a rear fixing portion screw portion is provided on the inner surface of the enlarged inner diameter portion 27c.
The middle fixed cylinder 26 is an annular member, and the outermost diameter 26 a is smaller than the inner diameter of the enlarged inner diameter portion 27 c of the rear fixed cylinder 27.

The lens barrel 1 of this embodiment includes a fixing ring 100 that connects the rear fixed cylinder 27 and the middle fixed cylinder 26.
The fixing ring 100 has an annular shape, and includes a cylindrical portion 101, a flange portion 102 that extends radially outward from an object-side end of the cylindrical portion 101, and an inwardly extending portion 103 that extends radially inward of the cylindrical portion 101. With.
A fixing ring screw portion 104 is provided on the outer diameter side of the cylindrical portion 101. The fixing ring screw part 104 is screwed to the rear fixing cylinder screw part 27a.

  A slope 105 is provided in a portion of the inward extending portion 103 that continues from the cylindrical portion 101. That is, the inner diameter gradually decreases from the cylindrical portion 101 to the inward extending portion 103.

  The middle fixed cylinder 26 is inserted from the enlarged inner diameter portion 27 c side of the rear fixed cylinder 27. Then, the cylindrical part 101 of the fixing ring 100 is screwed between the middle fixed cylinder 26 and the enlarged inner diameter part 27c of the rear fixed cylinder 27, and the rear fixed cylinder screw part 27a and the fixed ring screw part 104 are screwed together.

As the rotation of the fixing ring 100 proceeds, the inclined surface 105 of the fixing ring 100 presses the outer end of the middle fixed cylinder 26 on the subject side. The camera body side (imaging surface side) end surface of the middle fixed tube 26 is pressed against the side surface 27 b of the rear fixed tube 27.
Further, since the portion where the fixing ring 100 presses the middle fixed cylinder 26 is the slope 105, the middle fixed cylinder 26 is also pressed in the direction toward the optical axis OA (the direction toward the center), and the middle fixed cylinder 26 has the optical axis. Positioned in the direction toward OA.

(Effect of this embodiment)
(1) According to the present embodiment, the front fixed cylinder 24 provided with the first group cam pin 32 and the second pin 30 extending radially outward and the first group lens group L1 are indirectly held to hold the first group cam pin 32. Are engaged with each other, and a second inner cam groove 43 through which the second pin 30 moves is provided, and the first group cam pin 32 is rotated by the rotation of the front fixed cylinder 24 around the optical axis OA. A first lens moving cylinder 40 that is driven in the direction of the optical axis OA, and the second inner cam groove 43 is shorter than the first inner cam groove 42, and the first group cam pin 32 is the first inner cam groove 42. The second pin 30 is positioned outside the second inner cam groove 43 when positioned at the camera body side (imaging surface side) end.

  When an impact force F is applied from the front end, such as when the lens barrel 1 falls and collides with the ground, the impact force F is transmitted from the front end of the lens barrel 1 to the first lens moving barrel 40, and the first group Join the cam pin 32.

  Here, when the first group cam pin 32 is located in a region where the pressure angle θ of the first inner cam groove 42 (inclination with respect to the circumferential direction around the optical axis OA) is small as shown in FIGS. An impact force F in the optical axis OA direction is applied to the cam pin 32.

  However, in the present embodiment, the impact force F is applied by the first group cam pin 32 positioned in the first inner cam groove 42 and the second portion 30b of the second pin 30 positioned in the second inner cam groove 43. Can receive.

  Accordingly, it is possible to suppress damage due to a drop impact on the zoom driving portion such as the first group cam pin 32 that performs zooming driving, and to minimize optical performance deterioration due to zoom operation feeling and lens group eccentricity.

  Further, the second inner cam groove 43 provided in the first lens moving cylinder 40 is shorter than the first inner cam groove 42. Therefore, even if the structure has two cam grooves, the first lens moving barrel 40 can be shortened compared to the case where the second inner cam groove 43 and the first inner cam groove 42 have the same length. Therefore, the enlargement of the lens barrel 1 can be suppressed.

(2) According to the present embodiment, as shown in FIG. 4, the portion of the first inner cam groove 42 where the first group cam pin 32 is located when the second pin 30 is located outside the second inner cam groove 43. The pressure angle θ (that is, the inclination angle with respect to the circumferential direction around the optical axis OA) is larger than other portions of the first inner cam groove 42.

When the pressure angle θ is large, unlike the case shown in FIGS. 5 and 6 described above, the impact force F received from the tip can be absorbed by the retraction of the first lens moving barrel 40.
Therefore, since the damage to the first group cam pin 32 is small, there is a low possibility that the first group cam pin 32 and the like will be deformed without providing the shock absorbing structure by the second pin 30 at the wide end.

Therefore, in the present embodiment, the second inner cam groove 43 has a minimum necessary length, and the second inner cam groove 43 is not provided at the wide end where the impact force becomes small.
Since it is not necessary to provide the second inner cam groove 43 to the wide end, the length of the first lens moving cylinder 40 can be shortened, and a function necessary for shock absorption can be ensured and an increase in size of the product can be suppressed.

(3) According to the present embodiment, as shown in FIG. 7, the center 43 b in the direction along the optical axis OA of the second pin 30 in the second inner cam groove 43 is the optical axis of the second inner cam groove 43. It is offset to the subject side with respect to the center 43a in the direction along OA.

  That is, even if the impact force F shown in FIG. 7 is applied to the second pin 30 and the second pin 30 is bent, the bending direction is the camera body side where the gap D is wide. For this reason, when the 2nd part 30b of the 2nd pin 30 moves in the 2nd inner cam groove 43, possibility that it will collide with the side wall 43d of the 2nd inner cam groove 43 is low, and it may cause trouble in driving. Is low.

(4) Further, according to the present embodiment, the front fixed cylinder 24 provided with the circumferential groove 25 extending in the circumferential direction around the optical axis OA is provided, and the second pin 30 penetrates the circumferential groove 25 and is second. The second pin 30 is located inside the circumferential groove 25 even when the second pin 30 is located outside the second inner cam groove 43 by engaging with the inner cam groove 43.
Accordingly, since the second pin 30 is always located in the circumferential groove 25, the movement of the first cam cylinder 22 in the direction of the optical axis OA can be reliably restricted.

(5) The second pin 30 includes a first portion that engages with the circumferential groove 25 of the front fixed cylinder 24, a second portion that is disposed in the second inner cam groove 43, a first portion, and a second portion. And a small-diameter portion having a smaller diameter than the first portion and the second portion.

  According to the present embodiment, when the impact force F is applied to the second portion 30b, the second pin 30 receives the force F at the first portion 30a. Since the first portion 30a is supported by the side wall of the circumferential groove 25 of the front fixed cylinder 24, the second pin 30 can be prevented from falling from the root.

Moreover, when the side wall of the 2nd inner cam groove 43 collides with the 2nd part 30b and the 2nd part 30b is distorted, there exists a possibility that the small diameter part 30c may deform | transform in the direction which expands a diameter by the distortion.
Even in this case, since the small-diameter portion 30c has a smaller diameter than the second portion 30b and the first portion 30a, the second pin 30 becomes the first inner cam of the first lens moving barrel 40 due to the deformation of the small-diameter portion 30c. The possibility of not entering the groove 42 is low.

(6) The present embodiment includes a fixing ring 100 that connects the rear fixed cylinder 27 and the middle fixed cylinder 26.
For example, as a comparative form, when the middle fixed cylinder 26 and the rear fixed cylinder 27 are stopped with a screw or the like extending in a direction along the optical axis OA, it is necessary to use a screwdriver that is parallel to the optical axis OA. .
In this case, a space for turning the driver is required, but in the case of the lens barrel 1, it is difficult to secure a space along the optical axis OA.
Further, when the middle fixed cylinder 26 and the rear fixed cylinder 27 are stopped with a screw or the like extending in the direction (radial direction) toward the optical axis OA, the head of the screw protrudes to the outer diameter side, so the diameter of the lens barrel 1 is enlarged. Is done.

However, according to the present embodiment, the fixing ring 100 is used to fix the middle fixed cylinder 26 and the rear fixed cylinder 27, and it is not necessary to use a tool such as a screwdriver.
Further, since no screw is used, the screw head does not jump out in the radial direction.
Further, the positioning in the direction along the optical axis OA and the direction toward the optical axis OA can be performed by one fixing ring 100.

  L1: first lens group, L2: second lens group, L3: third lens group, L4: fourth lens group, OA: optical axis, 1: lens barrel, 2: camera body, 11: lens side mount section , 20: zoom operation ring, 21: zoom interlocking key, 22: first cam cylinder, 23: second cam cylinder, 24: front fixed cylinder, 25: circumferential groove, 26: middle fixed cylinder, 26a: outermost diameter , 27: rear fixed cylinder, 27a: rear fixed cylinder screw part, 27b: side surface, 27c: enlarged inner diameter part, 30: second pin, 30a: first part, 30b: second part, 30c: small diameter part, 30d: Fixed portion, 31: 1 group straight advance pin, 32: 1 group cam pin, 40: first lens moving barrel, 40a: end face, 41: inner straight advance groove, 42: first inner cam groove, 43: second inner cam groove, 43c: subject side end surface, 43d: imaging surface side end surface, 51: first moving frame 52: Second moving frame, 53: Third moving frame, 54: Fourth moving frame, 61: Focus ring, 100: Fixed ring, 101: Cylindrical part, 102: Gutter part, 103: Inward extension part, 104: Fixed Ring screw part, 105: Slope

Claims (10)

A first tube provided with a first protrusion and a second protrusion extending in a radial direction;
A first cam groove that holds the lens directly or indirectly and engages the first protrusion, and a second cam groove in which the second protrusion can be positioned inside are provided, and the light of the lens A second cylinder driven in the optical axis direction through the first protrusion by rotation about an axis,
When the first protrusion is located at one end of the first cam groove, the second protrusion is located outside the second cam groove;
A lens barrel characterized by The lens barrel according to claim 1,
A length of the second cam groove is shorter than a length of the first cam groove;
A lens barrel characterized by The lens barrel according to claim 1 or 2,
When the first protrusion is located at the other end of the first cam groove, the second protrusion is located inside the second cam groove;
A lens barrel characterized by The lens barrel according to any one of claims 1 to 3,
When the second protrusion is positioned outside the second cam groove, the portion of the first cam groove where the first protrusion is positioned has the optical axis more than the other portion of the first cam groove. The inclination with respect to the circumferential direction as the center is large,
A lens barrel characterized by The lens barrel according to any one of claims 1 to 4,
The center of the second protrusion in the second cam groove is at a position offset to the subject side with respect to the center of the second cam groove in the optical axis direction;
A lens barrel characterized by The lens barrel according to any one of claims 1 to 5,
A third cylinder provided with a circumferential groove extending in the circumferential direction around the optical axis, the second protrusion being located inside the circumferential groove;
When the second protrusion is located outside the second cam groove, the second protrusion is located inside the circumferential groove.
A lens barrel characterized by The lens barrel according to claim 6, wherein
The third cylinder is provided between the first cylinder and the second cylinder, and the second protrusion penetrates the circumferential groove;
A lens barrel characterized by The lens barrel according to claim 6 or 7,
The second protrusion is located between the first portion located in the circumferential groove of the third cylinder, the second portion located in the second cam groove, and the first portion and the second portion. And having a small diameter portion smaller in diameter than the first portion and the second portion,
A lens barrel characterized by The lens barrel according to any one of claims 1 to 8,
The second cylinder is provided on an outer peripheral side of the first cylinder, and the first protrusion and the second protrusion extend outward in the radial direction;
A lens barrel characterized by   A camera provided with the lens barrel of any one of Claims 1-9.

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