JP2006276204A - Lens hood - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lens hood which prevents an AF driving part from being applied with load when being attached/detached to/from a lens barrel and ensures an MF operation. <P>SOLUTION: The lens hood 1 is disposed on the objective-side end of the lens barrel 100, and detachably attached to a lens hood attaching part 130 rotated around an optical axis I relative to a lens barrel part 110 in conjunction with a focusing lens group. The lens hood 1 includes a rotation force transmitting section 21, which engages with the recess or projection 131 of the lens hood attaching part 130 and transmits rotation force, applied to the lens hood 1 around the optical axis I, to the lens hood attaching part 130. The rotation force transmitting part 21 is attached to the lens hood attaching part 130 by being approximately translated. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a lens hood provided at an objective end of a photographing lens barrel of a camera.

  In some camera lens barrels, the lens group disposed closest to the object side rotates around its optical axis during focusing. Such a photographing lens barrel is held by the user on the outer peripheral surface of a holding cylinder holding a lens group (hereinafter referred to as “objective lens group”) provided on the most object side during manual focus (MF). An MF operation ring (focus ring) that is an operation unit for rotating the cylinder is provided. Usually, such an MF operation ring is provided with uneven portions such as knurling or serration in order to improve operability.

On the other hand, a lens hood is attached to the distal end portion on the objective side of the photographing lens barrel in order to prevent external light from entering from outside the photographing angle of view and impairing the image quality of the captured image.
2. Description of the Related Art Conventionally, a lens barrel having an objective lens group as described above is known in which a lens hood is attached to the tip of a holding cylinder of the objective lens group by bayonet coupling.
However, such a lens barrel rotates when it acts on the holding cylinder when the lens hood is attached or detached while the holding cylinder of the objective lens group is connected to a driving unit such as an actuator for autofocus (AF). Due to the force, a load is applied to the AF drive unit such as a motor, a gear, and a screw.

Conventionally, a lens hood attached to such a lens barrel has a claw portion whose tip is pressed against a smooth portion of the outer peripheral surface of the holding tube of the objective lens group by a spring and can be retracted at the time of attachment / detachment. (For example, patent document 1) is known.
Such a lens hood can be mounted by inserting the lens barrel along the optical axis direction with the claw part retracted, so that no rotational force acts on the holding cylinder of the objective lens group at the time of attachment / detachment. The AF drive unit can be protected from the load.

However, since the lens barrel having the MF operation ring in the holding cylinder of the objective lens group is difficult to directly operate the MF operation ring when the lens hood is mounted, the focus is adjusted by rotating the lens hood during MF. Will do.
In the above-described conventional lens hood, only the frictional force between the claw portion and the holding cylinder restrains the rotation of the objective lens group around the optical axis with respect to the holding cylinder, and the rotational force exceeding this frictional force is applied. In some cases, slip occurs between the claw portion and the holding cylinder, and there is a possibility that the lens hood rotates with respect to the holding cylinder and accurate MF operation cannot be performed.
JP-A-5-323421

  An object of the present invention is to provide a lens hood capable of preventing an AF driving unit from being loaded when being attached to and detached from a lens barrel and performing MF operation with certainty.

  The present invention solves the above problems by the following means. In addition, in order to make an understanding easy, although the code | symbol corresponding to the Example of this invention is attached | subjected and demonstrated, it is not limited to this.

According to the first aspect of the present invention, a lens hood is provided at the objective end of the lens barrel (100) and rotates about the optical axis (I) relative to the lens barrel (110) in conjunction with the focusing lens group. In the lens hood (1) detachably mounted on the mounting portion (130), the lens hood (1) engages with a concave portion or a convex portion (131) formed on the lens hood mounting portion (130). A rotational force transmission part (21) for transmitting the applied rotational force around the optical axis (I) to the lens hood attachment part (130) is provided, and the rotational force transmission part (21) is provided in the lens hood attachment part (130). The lens hood (1) is mounted while being substantially translated in the optical axis (I) direction.
According to a second aspect of the present invention, in the lens hood (1) according to the first aspect, the optical hood (I) is locked to a locking target portion (132) formed in the lens hood mounting portion (130). A fixed position that restricts relative movement between the lens hood mounting portion (130) and the lens hood (1) in the direction, and a retracted position that releases the locking of the locking target portion and allows the relative movement. It is a lens hood (1) provided with the movable latching | locking part (40) which moves between.

  According to a third aspect of the present invention, a lens hood is provided at the objective end of the lens barrel (100) and rotates about the optical axis (I) with respect to the lens barrel (110) in conjunction with the focusing lens group. In the lens hood (1) detachably mounted on the mounting portion (130), the lens hood (1) engages with a concave portion or a convex portion (131) formed on the lens hood mounting portion (130). A rotational force transmitting portion (21) for transmitting the applied rotational force around the optical axis (I) to the lens hood mounting portion (130), and an engagement target portion (132) formed on the lens hood mounting portion (130). ) And a fixed position that restricts relative movement between the lens hood mounting portion (130) and the lens hood (1) in the optical axis (I) direction, and the locking target portion (132). Unlocked and said relative A lens hood (1), characterized in that it comprises movable locking portion to move between a retracted position for allowing the movement and (40).

According to a fourth aspect of the present invention, in the lens hood (1) according to any one of the first to third aspects, the rotational force transmitting portion (21) extends in the optical axis (I) direction. The lens hood (1) is characterized by comprising at least one of a protrusion and a groove formed to engage with the concave portion or convex portion (132) of the lens hood mounting portion (130).
According to a fifth aspect of the present invention, in the lens hood (1) according to any one of the first to fourth aspects, the rotational force transmitting portion (21) is a manual focus of the lens barrel (100). A lens hood (1) characterized by engaging with at least a part of a concave portion or a convex portion (131) formed in an operating portion (130) for performing adjustment.
A sixth aspect of the present invention is the lens hood (1) according to any one of the second to fifth aspects, wherein the movable locking portion (40) is connected to the rotational force transmitting portion (21). The lens hood (1) is characterized by being spaced apart in the direction of the optical axis (I).

According to the present invention, the following effects can be obtained.
(1) Since the lens hood includes a rotational force transmitting portion that engages with a concave portion or a convex portion formed in the lens hood mounting portion, an angle around the optical axis of the lens hood with respect to the lens hood mounting portion is caused by slip or the like. There is no deviation, and the rotational force around the optical axis applied by the user to the lens hood during the MF operation can be reliably transmitted to the focusing lens group side, and the reliability of the MF operation is ensured.
(2) Since the rotational force transmission part is attached to the lens hood attachment part while being moved substantially parallel to the optical axis direction, it prevents the rotational force around the optical axis from being applied to the lens hood attachment part during the attachment / detachment. In addition, the AF driving unit can be protected from an excessive load.
(3) Since the movement of the lens hood in the optical axis direction with respect to the lens hood mounting part is restricted or a movable locking part for releasing this restriction is provided, the lens hood is dropped from the lens hood mounting part in the optical axis direction. Can be prevented.
(4) Since the rotational force transmitting portion is engaged with the concave portion or the convex portion formed in the manual focus adjustment (MF) operation portion in the lens hood mounting portion, the concave and convex portions are formed on the lens barrel. There is no need to provide a separate engagement portion, and the degree of freedom in design and appearance quality of the lens barrel can be improved and operability during MF operation can be ensured.

  An object of the present invention is to form a lens barrel on the inner peripheral surface portion of a lens hood, which prevents a load from being applied to an AF driving unit when the lens barrel is attached to or detached from the lens barrel and provides a MF operation with certainty. The protrusion extending in the optical axis direction is realized by inserting and engaging with a knurled groove formed in the focus ring of the lens barrel and extending in the optical axis direction.

Hereinafter, the present invention will be described in more detail with reference to the drawings and the like.
FIG. 1 is a side view of an embodiment of a lens hood to which the present invention is applied, mounted on a lens barrel and viewed from a direction orthogonal to the optical axis, partially showing a cross section. FIG. 2 is an enlarged view of part II in FIG. 3 is a cross-sectional view taken along the line III-III in FIG. FIG. 4 is an enlarged view of a portion IV in FIG. 5 is a cross-sectional view taken along the line VV in FIG.

A lens barrel 100 to which the lens hood 1 is attached includes a lens barrel portion 110, a movable barrel 120, and a focus ring 130.
The lens barrel 110 is a cylindrical member that houses a plurality of lenses arranged in the optical axis I direction, and is fixed to a body (not shown) to which the lens barrel 100 is attached.
The movable cylinder 120 is housed on the inner diameter side of the lens barrel 110, is formed substantially concentrically with respect to the optical axis I, and changes the subject distance (shooting distance) of the lens barrel 100 by movement in the optical axis I direction. It accommodates a focusing lens group.

When the lens barrel 100 is focused by autofocus (AF), the movable barrel 120 is rotated around the optical axis I by an AF driving unit (not shown) and moved in the optical axis I direction.
Further, in a state where a clutch mechanism (not shown) provided between the movable cylinder 120 and the AF driving unit is disconnected, the movable cylinder 120 is rotated around the optical axis I by operating a focus ring 130 which will be described later. ) Focusing.

The focus ring (lens hood mounting portion) 130 is an annular member fixed to the end of the movable cylinder 120 on the objective side in the optical axis I direction and formed substantially concentrically with the optical axis I. It is arrange | positioned in the position protruded from the edge part of the objective side.
The focus ring 130 includes a knurled groove 131, a groove part 132, and a step part 133.

  The knurled groove 131 is formed by denting the outer peripheral surface of the focus ring 130 and extends in the direction of the optical axis I. As shown in FIG. 3, the knurled groove 131 is substantially equal over the entire circumference in the circumferential direction of the focus ring 130. Multiple arrays are arranged at intervals. Further, as illustrated in FIG. 2, the knurled groove 131 is formed in a region on the image side in the optical axis I direction of the focus ring 130. The knurled groove 131 is provided in order to improve operability and design when a user (not shown) operates the focus ring 130. In this embodiment, the ridge portion of the lens hood 1 described later is provided. 21 has a function of transmitting a rotational force around the optical axis I from the lens hood 1 to the focus ring 130. This point will be described in detail later.

The groove portion 132 is formed by denting the outer peripheral surface of the focus ring 130 and extends along the circumferential direction, and is for locking a locking claw 40 of the lens hood 1 described later. As shown in FIG. 2, the groove 132 is provided in a region on the objective side in the optical axis I direction of the focus ring 130, and is spaced from the knurled groove 131 described above in the optical axis I direction.
The outer diameter of the focus ring 130 is smaller in the region where the groove 132 is provided than in the region where the knurled groove 131 is provided, and a step where the outer diameter of the focus ring 130 changes in a stepped manner in the middle. A portion 133 is provided.

The lens hood 1 includes a cylindrical member 10, a rear cover 20, a detachable button 30, an engaging claw 40, and a spring 50.
As shown in FIG. 2, the tubular member 10 includes a cylindrical portion 10 a, a flange portion 10 b, and a light shielding portion 10 c.
The cylindrical portion 10a is formed in a substantially cylindrical shape, and a focus ring 130 is inserted on the inner diameter side thereof.
The flange portion 10b is formed in a ring plate shape so as to protrude from the end portion of the cylindrical portion 10a on the objective side in the optical axis I direction toward the outer diameter side.
The light shielding portion 10c is a cylindrical member that is formed by tapering a conical surface of a truncated cone having the optical axis I as a central axis, and shields unnecessary light from outside the angle of view. The end portion is connected to the outer peripheral edge of the flange portion 10b, the end portion on the larger diameter side is disposed on the objective side in the optical axis I direction with respect to the flange portion 10b, and an opening for taking in image light is provided.
The cylindrical portion 10a, the flange portion 10b, and the light shielding portion 10c are integrally formed by, for example, injection molding a resin material.

  The rear cover 20 is an annular member that is connected to the image side in the optical axis I direction of the cylindrical member 10 and in which a focus ring 130 is inserted on the inner diameter side thereof, with respect to the flange portion 10 b of the cylindrical member 10. Thus, they are opposed to each other in the direction of the optical axis I with an interval, and a space portion in which the engaging claw 40 and the spring 50 are accommodated is formed within this interval.

Further, as shown in FIGS. 2 and 4, the rear cover 20 is provided with a ridge (rotational force transmitting portion) 21 that protrudes from an inner peripheral surface facing the outer peripheral surface of the focus ring 130. .
The protrusion 21 is inserted into the knurled groove 131 of the focus ring 130 in a state where the lens hood 1 is mounted on the lens barrel 100, and is engaged with this to rotate around the optical axis I of the lens hood 1 with respect to the focus ring 130. Is formed to extend in the direction of the optical axis I.
Plural ridges 21 are provided, and these are inserted into different knurl grooves 131, but the ridges 21 do not have to be provided for all knurl grooves 131, and the user operates the lens hood 1 to perform MF operation. When performing the above, the number is set in consideration of reliably transmitting the rotational force applied to the lens hood 1 to the focus ring 130.
For example, as shown in FIGS. 3 and 4, in the case of the present embodiment, three protrusions 21 are provided in four regions provided around the optical axis I, for example, by approximately 90 ° apart. It has been.

  The detachable button 30 is an operation unit that is provided on the outer peripheral surface portion of the light shielding portion 10 c of the cylindrical member 10 and is operated when the lens hood 1 is attached to or removed from the lens barrel 100. For example, a pair of the detachable buttons 30 are provided substantially symmetrically with respect to the optical axis I, and are pressed to the side closer to the optical axis I during attachment and removal.

When the lens hood 1 is mounted on the lens barrel 100, the claw portion (movable locking portion) 40 is inserted into the groove 132 of the focus ring 130 so that the lens hood 1 is attached to the lens barrel 100. Is prevented from falling off in the direction of the optical axis I.
As shown in FIG. 5, the claw portion 40 is a small piece having a flat portion in a direction substantially orthogonal to the optical axis I, and an end portion of the claw portion 40 has an opening 11 formed in the cylindrical portion 10 a of the cylindrical member 10. The lens hood 1 is fixed in the direction of the optical axis I with respect to the focus ring 130, and moves in a direction away from the optical axis I with respect to the fixed state. The focus ring 130 is supported so as to be movable between a retracted position allowing movement in the optical axis I direction.
The claw portions 40 are provided at positions on both sides of the detachable button 30 around the optical axis I (circumferential direction).

As shown in FIG. 5, the spring 50 is provided between a pair of engaging claws 40 arranged with the same attaching / detaching button 30 interposed therebetween, and abuts against the attaching / detaching button 30 at an intermediate portion thereof. The spring 50 is formed of a wire material made of an elastic material such as spring steel, for example, and both ends thereof are inserted into the pair of engaging claws 40 and fixed, and an intermediate portion thereof is bent to be cylindrical member 10. The portion formed by protruding to the outer diameter side of the detachable button 30 is arranged in a state of being in pressure contact with the inner surface side of the detachable button 30.
In addition, the spring 50 abuts on the tip of the protrusion 12 formed by protruding from the outer peripheral surface of the cylindrical portion 10a of the cylindrical member 10 in the range between the detachable button 30 and each engaging claw 40. Is supported so as to be rotatable.

The interlocking of the above-described detachable button 30, engaging claw 40, and spring 50 will be described below.
In a state where the lens hood 1 is attached to the lens barrel 100, the spring 50 urges the engaging claw 40 in the direction approaching the optical axis I (fixed position side) by the elastic force, and the detachable button 30 is moved. It is in a state of being urged away from the optical axis I. Note that the force of the spring 50 at this time is set such that the engagement claw 40 does not cause damage or deformation to the focus ring 130 and the engagement claw 40 does not come off the groove 132 of the focus ring 130.
When the user presses the detachable button 30 in a direction approaching the optical axis I, the portion of the spring 50 between the detachable button 30 and each engaging claw 40 rotates with the tip end portion of the projection 12 as a fulcrum and engages. The claw 40 moves in a direction away from the optical axis I.
Further, when the user releases the detachable button 30 again, the detachable button 30 and the engaging claw 40 are automatically returned to their original positions by the elastic force of the spring 50.

Next, the usage method of the lens hood 1 of a present Example is demonstrated.
<Lens hood installation>
In a state where the detachable button 30 is pressed to the optical axis I side, the lens hood 1 is translated (straightly moved) along the direction of the optical axis I with respect to the lens barrel 100 and moved toward the inner diameter side of the cylindrical portion 10 a of the cylindrical member 10. A focus ring 130 is inserted. At this time, the plurality of protrusions 21 of the rear cover 20 are inserted into the knurled grooves 131 of the corresponding focus rings 130 respectively.
Then, after the lens hood 1 reaches a predetermined mounting position with respect to the lens barrel 100 in the optical axis I direction, the detachable button 30 is released. As a result, the end of the engaging claw 40 is inserted into the groove 132 of the focus ring 130, and the lens hood 1 is fixed in the optical axis I direction with respect to the focus ring 130.
<MF operation>
An AF / MF switching operation unit (not shown) provided in a body (not shown) or the lens barrel part 110 of the lens barrel 100 is operated to release the connection between the AF driving unit (not shown) and the movable cylinder 120.
In this state, the movable tube 120 is rotated around the optical axis I by holding the light shielding portion 10c of the cylindrical member 10 of the lens hood 1 and rotating the lens hood 1 around the optical axis I with respect to the lens barrel 110. In conjunction with this, a focusing lens group (not shown) accommodated in the movable cylinder 120 is moved in the direction of the optical axis I to perform focusing.
<Removing the lens hood>
The engaging claw 40 is extracted from the groove 132 of the focus ring 130 by pulling the lens hood 1 toward the objective side in the optical axis I direction with respect to the lens barrel 110 while pressing the detachable button 30 toward the optical axis I. The lens hood 1 is removed from the lens barrel 100.

As described above, according to this embodiment, the following effects can be obtained.
(1) The ridge 21 formed on the inner peripheral surface of the rear cover 20 of the lens hood 1 and extending in the direction of the optical axis I is engaged with the knurled groove 131 formed on the outer peripheral surface of the focus ring 130. Thus, the rotational force around the optical axis I applied to the lens hood 1 during the MF operation is reliably transmitted to the lens barrel 100 side, and the reliability of the MF operation can be ensured.
(2) The protrusion 21 of the lens hood 1 is inserted into the knurled groove 131 of the focus ring 130 by moving the lens hood 1 in the direction of the optical axis I with respect to the lens barrel 100. Excessive torque around the optical axis I is not input to the focus ring 130 during attachment / detachment, and the mechanism in the lens barrel 100 such as the AF drive unit can be protected.
(3) Since the engagement claw 40 moves between a fixed position where a part of the focus ring 130 is inserted into the groove 132 and a release position extracted from the groove 132, the lens hood 1 is provided with a lens mirror. It is possible to prevent the tube 100 from falling off in the optical axis direction. Further, the engaging claw 40 moves from the fixed position to the released position by pressing the attaching / detaching button 30, and automatically returns to the fixing position by releasing the attaching / detaching button 30, so that the attaching / detaching operation is easy. is there.
(4) Since the protrusion 21 of the lens hood 1 is engaged with a knurled groove 131 provided to improve the design and operability of the focus ring 130, the protrusion 21 is engaged with the lens barrel 100 side. Therefore, there is no need to provide other concave portions or convex portions, and the design freedom and appearance quality of the lens barrel 100 can be improved and operability during MF operation can be ensured.

(Modification)
The present invention is not limited to the embodiments described above, and various modifications and changes can be made, and these are also within the equivalent scope of the present invention.
(1) The shape and configuration of the rotational force transmitting portion on the lens hood side, the movable locking portion, the concave or convex portion on the lens barrel side, and the locking target portion are not limited to the above-described embodiments, and may be changed as appropriate. Can do.
(2) In the embodiment, the rotational force transmitting portion and the movable locking portion are provided independently. For example, the movable locking portion is provided with a function of preventing an angle shift around the optical axis with respect to the lens hood mounting portion. It is good also as a structure where a latching | locking part serves as a rotational force transmission part.

It is the side view seen from the direction which mounts the example of the lens hood to which the present invention is applied to the lens barrel, and is orthogonal to the optical axis. It is the II section enlarged view of FIG. FIG. 3 is a cross-sectional view taken along the line III-III in FIG. 1. It is the IV section enlarged view of FIG. It is a VV section arrow sectional view of Drawing 1.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Lens hood 10 Cylinder member 12 Protrusion 20 Rear cover 21 Projection 30 Detachable button 40 Engagement claw 50 Spring 100 Lens barrel 130 Focus ring 131 Knurled groove 132 Groove part

Claims (6)

In the lens hood that is provided at the objective end of the lens barrel and is detachably mounted on the lens hood mounting portion that rotates about the optical axis relative to the lens barrel portion in conjunction with the focusing lens group,
A rotational force transmitting portion that engages with a concave portion or a convex portion formed in the lens hood mounting portion and transmits a rotational force around the optical axis applied to the lens hood to the lens hood mounting portion;
The lens hood according to claim 1, wherein the rotational force transmitting portion is attached to the lens hood attaching portion while being moved substantially parallel to the optical axis direction. The lens hood according to claim 1,
A locking position that is locked to a locking target portion formed on the lens hood mounting portion and restricts relative movement between the lens hood mounting portion and the lens hood in the optical axis direction, and the locking target portion. A lens hood comprising: a movable locking portion that is unlocked and moves between the retreat position that allows the relative movement. In the lens hood that is provided at the objective end of the lens barrel and is detachably mounted on the lens hood mounting portion that rotates about the optical axis relative to the lens barrel portion in conjunction with the focusing lens group,
A rotational force transmitting portion that engages with a concave portion or a convex portion formed in the lens hood mounting portion and transmits a rotational force around the optical axis applied to the lens hood to the lens hood mounting portion;
A locking position that is locked to a locking target portion formed on the lens hood mounting portion and restricts relative movement between the lens hood mounting portion and the lens hood in the optical axis direction, and the locking target portion. A lens hood, comprising: a movable locking portion that is unlocked and moves between a retraction position that allows the relative movement. In the lens hood according to any one of claims 1 to 3,
The rotational force transmitting portion is formed to extend in the optical axis direction, and includes at least one of a ridge portion and a groove portion that engages with the concave portion or the convex portion of the lens hood mounting portion. hood. In the lens hood according to any one of claims 1 to 4,
The lens hood characterized in that the rotational force transmitting portion engages with at least a part of a concave portion or a convex portion formed in an operation portion that performs manual focus adjustment of the lens barrel. The lens hood according to any one of claims 2 to 5,
The lens hood according to claim 1, wherein the movable locking portion is disposed apart from the rotational force transmitting portion in the optical axis direction.

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