JP2004170492A - Lens hood - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve operability at the time of housing and pulling out a lens hood and to ensure holding ability at respective lock positions at the time of housing and pulling out. <P>SOLUTION: The lens hood 20 incorporated in a lens barrel 10 is constituted of a hood main body 21 and a hood operation ring 22 capable of sliding on the main body 21. By moving the ring 22 leftward, a lock ball 25 attached to be displaced in a radial direction on the main body 21 is released from restriction by the inner peripheral surface 22a of the ring 22 and housed in a lock releasing groove 22c, and the lock of the main body 21 is released and the main body is integrally moved leftward. After the ball 25 is engaged with a 1st lock groove 14 at a leftward end, the ring 22 is moved leftward further so as to restrict the ball 25 in a lock state. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a lens hood attached to a distal end of a lens barrel in order to block harmful light rays from outside the angle of view of a camera lens, and more particularly to a lens hood which is previously irremovably incorporated into a lens barrel.
[0002]
[Prior art]
This type of built-in type lens hood has no risk of loss or forgetting to carry it, which is likely to occur with the commonly used detachable lens hood, and it is not bulky and requires no time for mounting and dismounting. It is widely used in single-focal lenses, especially large-diameter single-focal telephoto lenses.
In such a conventional built-in lens hood, generally, a friction member that acts as a sliding resistance is interposed between the lens hood and the lens barrel, and is pulled out or pushed in the optical axis direction against the frictional force. It is held at each position as a light shielding position at the time of photographing or a storage position at the time of non-use.
However, according to such a configuration, if the frictional force between the lens barrel and the lens hood is too weak, the lens hood may inadvertently protrude from the lens barrel due to an impact or its own weight during carrying, and may come into contact with other objects. There is a possibility that the hood effect may be reduced due to damage or being pushed during the continuation of shooting, and there is a problem that operability is impaired if the frictional force is too strong.
[0003]
In order to solve such a problem, three locking projections each having a semicircular cross section are integrally formed on the front inner peripheral surface and the rear inner peripheral surface on the lens hood side, and these locking projections are formed on the lens hood. There is disclosed a lens hood that can be firmly held in a storage position or a use position by engaging a locking ring protruding from an outer peripheral surface on the distal end side of a lens barrel (for example, see Patent Document 1).
[0004]
[Patent Document 1]
Japanese Patent Application Laid-Open No. 2001-221939
[Problems to be solved by the invention]
However, in such a conventional lens hood, when the lens hood is repeatedly slid over the lens barrel, the locking projection formed on the inner peripheral surface is worn and the locking force is weakened, and the lens hood is held. If the lens barrel is lifted by the user, the lens hood may be pulled out against the locking force with the lens barrel due to the weight of the lens barrel or an impact at the time of lifting.
In addition, the locking projection formed at the tip of the inner peripheral surface of the lens hood slides on the locking ring protruding at the tip of the outer peripheral surface of the lens barrel, and a bright portion having extremely high reflectance is generated on the surface. When a strong light ray such as the sun or an artificial light source is reflected, it is irregularly reflected on the inner surface of the lens hood or the inner surface of the lens barrel, causing ghosts and flares, and the aesthetic appearance is impaired.
The present invention has been made in view of the above points, and improves operability at the time of storage and withdrawal, ensures retention at each locking position, and greatly increases durability over time. It is intended to provide a lens hood to obtain.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, the present invention is a lens hood that is slidably mounted in the optical axis direction on a front outer peripheral surface of a lens barrel and is lockable at each sliding end. A hood operating member slidably mounted on the hood main body in a predetermined range optical axis direction, and by moving the hood operating member, the hood main body can be locked or released to the lens barrel. The lens hood is provided.
A lens hood slidably mounted in the optical axis direction on the front outer peripheral surface of the lens barrel and lockable at each sliding end, wherein the lens hood is provided on the front outer peripheral surface of the lens barrel in the optical axis direction. A hood main body having a lock member slidably mounted on the lens barrel and capable of engaging with a lock groove formed in the lens barrel, and slidably mounted in the optical axis direction in a predetermined range on the rear outer peripheral surface of the hood main body. A lens hood having an inner peripheral surface capable of restraining the lock member in the lock groove, and a lock release groove provided in the inner peripheral surface including a hood operating member capable of releasing the lock member from the lock groove. Also provide.
[0007]
In the above-mentioned lens hood, it is further preferable that a friction member for providing a sliding resistance and a cushioning member for reducing an impact at the time of abutment are interposed between the lens barrel and the hood main body. Further, in such a lens hood, it is preferable that a click means for regulating the relative movement in the optical axis direction is provided between the hood main body and the hood operation member. Further, in the lens hood having such a configuration, it is more preferable that the lock member has a spherical shape, and the lock groove and the lock release groove have a trapezoidal cross section.
With the lens hood according to the present invention configured as described above, the lens hood is securely locked to the lens barrel in the retracted state and the pulled-out state, and there is no risk of accidentally unlocking the lens hood. By slightly driving in the direction, the lock can be released with one touch, and the operability is extremely good.
[0008]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be specifically described with reference to the drawings.
FIG. 1 is a sectional view of a lens hood retracted state showing an embodiment of the present invention together with a lens barrel, and FIG. 2 is a sectional view of the lens hood pulled out state. In FIGS. 1 and 2, parts that are not necessarily on the same plane are also shown in the same cross section in order to reduce the number of drawings and to make it easier to understand the positional relationship of related members. The internal configuration of the lens barrel has no direct relation to the gist of the present invention, and is not shown.
The lens barrel 10 having the optical axis A is provided integrally with a first locking portion 11 formed of a ridge on the entire periphery of a front end portion (left end portion in FIG. 1) and a rear end portion (right end portion in FIG. 1). Is provided integrally with a lens mount 18 that can be attached to and detached from a mount section of a camera body (not shown). Further, a second locking portion 12 is provided on the outer peripheral portion of the lens barrel 10 having a stepped portion having a slightly smaller diameter in the front half, and a first trapezoidal section is provided on the outer peripheral surface of the small-diameter portion 13 of the lens barrel. The lock groove 14 and the second lock groove 15 are respectively recessed.
[0009]
On the other hand, a substantially cylindrical hood main body 21 forming a light shielding portion of the lens hood 20 is slidably mounted in the direction of the optical axis A on the outer peripheral portion of the lens barrel small diameter portion 13 of the lens barrel 10. A hood operating ring 22, which is a hood operating member capable of locking and releasing the hood main body 21 to the outer peripheral surface of the lens barrel 10, is slidably mounted on the rear outer peripheral surface of the lens 21 in the direction of the optical axis A in a predetermined range.
The hood main body 21 has a hood small-diameter portion 21a having a slightly smaller inner and outer peripheral surface formed at the rear as shown in an enlarged detail in FIG. A friction ring 23 is slidably mounted on the small-diameter portion 13 of the lens barrel. At both front and rear ends on the inner peripheral side of the hood small diameter portion 21a, buffer rings 24, 24 made of a resin material or the like are fixedly provided as buffer members, and when the hood main body 21 advances and retreats, the first and the first of the lens barrel 10 are moved. Damage and impact noise caused by impact when the second engagement portions 11 and 12 come into contact with each other are reduced.
[0010]
Further, a through hole 21b is formed in the hood small diameter portion 21a at a position facing the first and second lock grooves 14 and 15 of the lens barrel 10 at the forward end and the backward end of the hood main body 21. In a state where the lock ball 25 constituting the lock member 21 is freely rollable and radially displaceable, and the lock ball 25 is engaged with the first and second lock grooves 14 and 15, the top of the lock ball 25 is The outer peripheral surface of the hood small-diameter portion 21a is substantially flush with the outer peripheral surface. Although one through hole 21b and one lock ball 25 may be provided, it is preferable to provide a plurality of (eg, three) holes at substantially equal intervals on the same circumference.
Further, click grooves 21c, 21d, and 21e formed of three circumferential grooves are formed at substantially the same interval in the rear half of the outer peripheral surface of the hood small-diameter portion 21a, and are formed on a cross section different from the cross section including the through hole 21b. A guide shaft 26 (see FIG. 1) for guiding a hood operation ring 22 described later in the optical axis A direction is implanted.
[0011]
On the other hand, as shown in FIGS. 1 and 2, a hood operation ring 22 which is a hood operation member slidably mounted on the outer peripheral surface of the hood small diameter portion 21a slides on the outer peripheral surface of the hood small diameter portion 21a of the hood main body 21. The inner peripheral surface 22a in contact with, the elongated hole 22b in which the guide shaft 26 on the hood body 21 side is loosely fitted to regulate the movement amount in the optical axis A direction, and the lock ball 25 is the first and second of the lens barrel 10. A lock release groove 22c having a trapezoidal cross section capable of storing the lock ball 25 in a state of being detached from the lock grooves 14 and 15 and slidingly contacting the hood small diameter portion 21a (see FIG. 7).
The hood operation ring 22 has a stepped transparent surface facing the click grooves 21e and 21c of the hood body 21 at the retracted position and the advanced position, as shown in FIGS. A hole 22d is formed, and a click ball 27 is inserted into the small-diameter portion side so as to be able to roll and displace freely, and is pressed in the inner diameter direction by a click spring 28 composed of a leaf spring mounted on the large-diameter portion side. The click ball 27 engages with the middle click groove 21d in accordance with the movement of the hood operation ring 22 in the optical axis direction. A non-slip ring 22e made of rubber or resin is attached to an outer peripheral portion of the hood operation ring 22 to improve operability.
[0012]
Next, the operation of the embodiment configured as described above will be described. In the retracted state of the lens hood 20 shown in FIGS. 1, 3 and 4, the buffer ring 24 provided at the rear end of the hood main body 21 comes into contact with the second locking portion 12 of the lens barrel 10 and then retracts. Is locked. The lock ball 25 provided on the hood main body 21 is engaged with the second lock groove 15 of the lens barrel 10, and the outside thereof is sealed with the inner peripheral surface 22 a of the hood operation ring 22. Locked non-slidably to the lens barrel. In this state, as shown in FIG. 1, the guide shaft 26 of the hood main body 21 contacts the tip end of the long hole 22 b of the hood operation ring 22 and is located at the rearmost portion of the hood main body 21. The click ball 27 is engaged with the rear click groove 21e.
[0013]
When the hood operation ring 22 is moved forward (to the left in the figure) against the urging force of the click spring 28 from this state, the click ball 27 engages with the central click groove 21d of the hood body 21 and locks. The ball 25 faces the lock release groove 22c of the hood operation ring 22. When the hood operating ring 22 is further advanced, the hood main body 21 integrated by the click force advances integrally, and the side wall surface of the through hole 21b of the hood main body 21 presses the lock ball 25 to the left. As a result, the lock ball 25 is pressed outward by the tapered surface of the second lock groove 15 having a trapezoidal cross section, is housed in the lock release groove 22c of the hood operation ring 22, and the lock of the hood body 21 is released. It can freely slide in the direction of the axis A (see FIG. 7). The buffer ring 24 on the front end side of the hood main body 21 abuts on the first locking portion 11 of the lens barrel 10, and the forward movement of the hood main body 21 is locked.
[0014]
In this state, the lock ball 25 on the side of the hood main body 21 is located at a position facing the first lock groove 14 of the lens barrel 10. Even after the forward movement of the hood body 21 is locked, the hood operation ring 22 further moves forward against the click force with the hood body 21, and the right end of the long hole 22 b (see FIG. 2) is located on the hood body 21 side. When the click ball 27 comes into contact with the guide shaft 26 and engages with the click groove 21c on the hood main body 21 side, its advance is stopped, and the state shown in FIGS. 5 and 6 is obtained. In the last step, when the hood operation ring 22 moves to the left, the tapered portion of the lock release groove 22c having a trapezoidal cross section presses the lock ball 25 inward to engage with the first lock groove 14, and then the hood The inner peripheral surface 22a of the operation ring 22 restricts the outward movement of the lock ball 25 and locks the hood main body 21 to the hood use position. When the lens hood 20 is stored from this state, the hood operation ring 22 may be retracted along the optical axis A direction.
[0015]
In the above embodiment, the case of a cylindrical lens hood in which the hood body can be freely rotated around the optical axis of the lens barrel has been described. FIG. 9 shows a flower-shaped hood in which the light shielding efficiency is further enhanced. 9 is a side view showing a part of another embodiment in a case where it is desired to restrict the angular position at the time of use, and FIG. 10 is a transverse sectional view taken along line XX of FIG.
In this embodiment, a pair of guide shafts 16, 16 are implanted at positions that are vertically (or left and right) when mounted on a camera body (not shown) on the outer peripheral surface on the distal end side of the lens barrel 10, and the distal end portion is A guide groove 31a, 31a parallel to the optical axis A is provided on an inner surface of the hood main body 31 formed in a petal shape and facing the guide shafts 16, 16, and a hood operation ring 32 is provided at a cylindrical rear end of the hood main body 31. The lens hood 30 is provided so as to be slidable in a predetermined range in the direction of the optical axis A. Other configurations and operations are the same as those of the previous embodiment. According to this embodiment, a flower-shaped lens hood having a very high shielding efficiency can be incorporated into the lens barrel with a simple configuration. FIG. 9 shows only one of the guide shaft 16 and the guide groove 31a.
[0016]
As described above, since the lens hood according to the present invention is securely locked to the lens barrel when the lens hood is used when the lens hood is in the retracted state and when the lens hood is not in the retracted state, the lens hood or lens is held by holding the hood body when the lens hood is stored Even if the camera with the lens barrel is lifted, there is no danger that the lock will be released due to the weight of the lens barrel or the camera with the lens barrel. And the light shielding effect is not reduced. In addition, to change from the storage state or the drawer state to the use state or the non-use state, it is sufficient to move the hood operation member in the same direction, and at that time, there is an appropriate click interval, so that locking and unlocking can be performed. The feeling transmitted to the fingertip makes the operation feel good, and the lock is not inadvertently released. Further, since no friction member is used for locking the lens hood, the lens hood can be used for a long period of time, and there is no shining part due to abrasion on the inner surface of the hood, and there is no possibility of harmful internal reflection.
In the above embodiment, as the locking means for locking the hood main body to the lens barrel, the lock ball is provided on the hood main body side, and the lock groove is provided on the lens barrel side. In addition, the hood operating member may have a sliding switch shape instead of a ring shape, and the click means provided between the hood main body and the hood operating member may be provided with either the click ball or the click groove.
[0017]
【The invention's effect】
As described above, according to the present invention, the following effects can be obtained.
According to the lens hood according to the first aspect, the lens hood is composed of the hood main body and the hood operation member, and the lock can be easily released by one touch by moving the hood operation member back and forth. Is very good.
According to the lens hood of the second aspect, the lock member on the hood main body side is housed in the lock release groove of the hood operation member from the state in which the lock member on the lens body side can be restrained by the movement of the hood operation member in the optical axis direction. The release state can be switched to a possible release state, and the locking and unlocking of the hood body to and from the lens barrel can be reliably performed. In addition, even if the lens barrel or the camera on which the lens barrel is mounted is lifted by holding the hood body when the lens hood is stored, there is no danger that the hood body will be unlocked by its own weight, and carelessly when pulling out the lens hood. There is no risk of being pushed in even if it touches the hood body. Furthermore, since a sliding member is not used as a member for locking the lens hood to the lens barrel, even when used for a long period of time, the locking force does not decrease due to abrasion and the durability can be greatly improved. There is no danger of internal reflection due to this.
[0018]
According to the lens hood of the third aspect, since the friction member is interposed between the lens barrel and the hood main body, the lens barrel can be turned up and down or strongly operated with the hood main body unlocked. In this case, the lens hood does not move suddenly.
According to the lens hood of the fourth aspect, since the cushioning member is interposed between the lens barrel and the hood main body, even if the hood main body and the lens barrel may suddenly come into contact with each other. There is no danger of significant damage or impact noise.
According to the lens hood of the fifth aspect, since the click means is provided between the hood main body and the hood operation member, even when the hood main body is in the locked state, even if the hood operation member is accidentally touched, carelessness is provided. The lock is not unlocked and the lock and unlocked state can be recognized by touch when the hood body is stored or pulled out, so that the operational feeling is further improved.
[0019]
According to the lens hood of the sixth aspect, since the lock member is spherical, when the lock member transitions from the lock groove to the lock release groove, smooth transition by rolling is possible.
According to the lens hood according to the seventh aspect, since the lock groove has a trapezoidal cross section, a component force that pushes up the lock member by the side taper portion of the lock groove is generated due to the movement of the hood body in the optical axis direction, and the lock groove generates a component force. It can be easily removed.
According to the lens hood of the eighth aspect, since the lock release groove has a trapezoidal cross section, a component force for pushing the lock member into the lock groove by the side taper portion of the lock release groove at the moving end of the hood operating member in the optical axis direction. Is generated, and the lock member can be easily engaged with the lock groove.
[Brief description of the drawings]
FIG. 1 is a sectional view of a lens hood stored state showing an embodiment of the present invention together with a lens barrel.
FIG. 2 is a cross-sectional view of the lens hood pulled out.
FIG. 3 is a cross-sectional view of the lens hood retracted state showing a main part of the lens hood.
FIG. 4 is a cross-sectional view of the lens hood stored in a different angle position from FIG.
FIG. 5 is a cross-sectional view of the lens hood pulled out, showing a main part thereof in an enlarged manner.
FIG. 6 is a cross-sectional view of the lens hood in a different angle position from FIG.
FIG. 7 is a cross-sectional view showing a state where the lens hood is moved, showing a main part thereof in an enlarged manner.
FIG. 8 is a cross-sectional view of a different angle position from FIG. 7 showing a state when the lens hood is moved, showing a main part thereof in an enlarged manner.
FIG. 9 is a side view showing a cross section of a part of a stored state of a lens hood showing another embodiment of the present invention together with a lens barrel.
FIG. 10 is a sectional view taken along the line XX in FIG. 9;
[Explanation of symbols]
10: Lens barrel 11: First locking portion 12: Second locking portion 14: First locking groove 15: Second locking groove 18: Lens mount 20, 30: Lens hood 21, 31: Hood Main body 22, 32: Hood operation ring 22a: Inner peripheral surface 23: Friction ring 24: Buffer ring 25: Lock ball 26: Guide shaft 27: Click ball 28: Click spring

Claims (8)

A lens hood that is slidably mounted in the optical axis direction on a front outer peripheral surface of the lens barrel and is lockable at each sliding end,
A hood main body, and a hood operating member slidably mounted on the hood main body in a predetermined range in the optical axis direction. By moving the hood operating member, the hood main body is locked or released to the lens barrel. A lens hood characterized in that it can be used. A lens hood that is slidably mounted in the optical axis direction on a front outer peripheral surface of the lens barrel and is lockable at each sliding end,
A hood main body having a lock member mounted on the front outer peripheral surface of the lens barrel so as to be slidable in the optical axis direction and capable of engaging with a lock groove formed in the lens barrel; and a rear outer peripheral surface of the hood main body Is mounted slidably in the direction of the optical axis, the inner peripheral surface of which is capable of restraining the lock member in the lock groove, and the unlocking groove provided in the inner peripheral surface is configured to lock the lock member with the lock groove. A lens hood comprising a hood operating member which can be released from the lens hood. 3. The lens hood according to claim 1, wherein a friction member for providing sliding resistance is interposed between the lens barrel and the hood body. The lens hood according to any one of claims 1 to 3, wherein a buffer member is provided between the lens barrel and the hood body to reduce an impact when the two are in contact with each other. The lens hood according to any one of claims 1 to 4, wherein a click means for restricting the relative movement in the optical axis direction is provided between the hood main body and the hood operation member. The lens hood according to claim 2, wherein the lock member is spherical. 7. The lens hood according to claim 2, wherein the lock groove has a trapezoidal cross section. The lens hood according to claim 2, wherein the lock release groove has a trapezoidal cross section.

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