JP4796864B2 - Shading device - Google Patents

Description

  The present invention relates to a light shielding device such as a hood and a hood applicable to optical devices such as binoculars, monoculars, a finder of a video camera, and a camera.

  An eyepiece of an optical device, for example, binoculars, is held by an eyepiece lens barrel, and an eyepiece as a light shielding device may be provided on the outer peripheral surface of the eyepiece lens barrel. The aim is slidable parallel to the optical axis for the purpose of matching the position of the pupil of the observer with the eye point of the optical observation device and shielding unnecessary light.

  For example, when a binocular is used by a naked eye observer, the eyepiece is pulled out to the eyepiece side, while when used by an observer wearing eyeglasses, the eyepiece is stored on the objective side, so that the observer wears the eyeglasses. In both cases, the position of the observer's pupil and the eye point of the binoculars are made to coincide with each other regardless of whether the eye is naked.

  For example, as described in Patent Document 1, the eyepiece is provided with a spiral groove extending in a spiral shape on the inner peripheral surface of the eyepiece ring, while a screw that engages the spiral groove is provided on the eyepiece lens barrel. When the screw moves along the groove, the screw is slid in parallel with the optical axis while rotating in the circumferential direction.

For example, as described in Patent Documents 2 and 3, the eyepiece lens barrel is provided with a groove parallel to the optical axis, while the eye ring is provided with a protrusion, and the protrusion moves along the groove. Thus, the aiming device is slid linearly in parallel with the optical axis.
JP 2003-005092 A JP-A-8-194169 Japanese Utility Model Publication No. 8-000892

  In the above-mentioned aim, it is known that the eye stop is click-stopped at a predetermined position in order to make the position of the eye point and the pupil of the observer wearing the naked eye or glasses. However, in the purpose described in the above-mentioned document, there is a problem that when click-stopping, a spring, a ball or the like is used, and the number of parts increases.

  Further, in the purpose of the above-mentioned document, the aiming ring is slid and moved in parallel with the optical axis by either one of the rotational movement and the linear movement. Then, there is a problem that it is not easy to use. For example, a linear movement configuration is difficult in terms of operability because it is difficult to stop at an intermediate position in the movement range. In addition, with the rotational movement configuration that rotates the eyepiece, stopping at the intermediate position is easy, but the structure is complicated and it is difficult to reduce the size.

  Furthermore, the hood provided at the tip of the camera lens barrel is also required to be moved or removed when not in use to shorten the overall length of the camera lens. is there.

  Accordingly, the present invention has been made in view of these problems, and an object thereof is to provide a light shielding device that has a small number of parts and can be moved by any of the rotational movement and linear movement methods. .

  The light-shielding device according to the present invention accommodates an optical member, a lens barrel provided with two or more protrusions on the outer peripheral surface thereof, and a concentrically provided on the outer peripheral side of the lens barrel, and each protrusion is engaged 2 The guide groove is formed on the inner peripheral surface, and includes a light-shielding ring having a light-shielding member for shielding a part of light incident on the optical member, and each protrusion moves along each guide groove, In the light shielding device, the light shielding ring is movable relative to the lens barrel, and a recessed portion further recessed from the guide groove is provided in each guide groove. When the projection is engaged with the guide groove, the light shielding ring is pressed by the projection from the radially inner side to the outer side, and the portion between the projections of the light shielding ring is deformed so as to bend radially inward. When the portion is close to the lens barrel, the protrusion is prevented from being detached from the guide groove. On the other hand, when the protrusion is engaged in the recessed portion, the pressing force from the protrusion to the light shielding ring is weakened by a predetermined amount, and the light shielding ring is click-stopped. The optical member in the present invention is, for example, a lens.

  With the above configuration, in the light-shielding device according to the present invention, when the projections are to be detached from the guide groove, the portion between the projections of the light-shielding ring comes into contact with the lens barrel and tightens the lens barrel. To prevent it. Therefore, in the present invention, the extending direction of each guide groove can be set as appropriate, and for example, it can be a linear groove extending linearly parallel to the optical axis. It is also possible to form a spiral groove that extends in a spiral manner in an oblique direction with respect to the optical axis. Further, it is possible to form a circumferential groove extending in the circumferential direction of the light shielding ring. Moreover, it is also possible to comprise a straight groove and a spiral groove branched from the straight groove and extending in an oblique direction.

  In the present invention, the light shielding member is, for example, an eyepiece for an optical device such as binoculars, or a lens hood provided at the tip of a photographing lens barrel of a camera.

  The first distance from the optical axis of the lens to the tip of the protrusion is preferably larger than the second distance from the optical axis to the tip of the recess and the third distance from the optical axis to the tip of the guide groove. More preferably, the second distance is greater than the third distance.

  It is preferable that the inner peripheral surface of the recessed portion, the inner peripheral surface of the guide groove, and the outer peripheral surface of the protrusion are curved surfaces. As described above, when the inner peripheral surface and the outer peripheral surface are formed as curved surfaces, the protrusion can smoothly move in the guide groove.

  The inner peripheral surface of the recessed portion, the inner peripheral surface of the guide groove, and the outer peripheral surface of the protrusion are each formed of, for example, a curved curved surface. And it is preferable that the curvature radius of the outer peripheral surface of a protrusion is smaller than the curvature radius of the inner peripheral surface of a guide groove. When the radius of curvature is set in this way, only one point of the tip of the protrusion comes into contact with the groove tip of the guide groove, so that the protrusion engages with the guide groove, so that the protrusion moves more smoothly in the guide groove. Can do.

  Moreover, it is preferable that the curvature radius of the outer peripheral surface of a protrusion is larger than the curvature radius of the inner peripheral surface of a recessed part. When the radius of curvature is set in this way, when the protrusion is engaged with the recessed portion, the tip end portion of the protrusion cannot contact the inner peripheral surface of the recessed portion, but the side peripheral surface of the protrusion is the inner periphery of the recessed portion. It abuts on the side surface of the surface by line contact. Therefore, since the protrusion is stably supported by the recessed portion, the click stop can be reliably performed.

  For example, the outer peripheral surface of the protrusion is formed of a convex spherical surface, the inner peripheral surface of the recessed portion is formed of a concave spherical surface, and the inner peripheral surface of the guide groove has an arc shape with a circumferential angle of 10 ° to 180 °.

  The guide groove should preferably include a tapered groove for introducing the protrusion from one opening of the light shielding ring into the recessed portion, and the distance from the tip of the tapered groove to the optical axis of the lens is, for example, recessed from the opening side. It becomes gradually smaller toward the part.

  The light-shielding device according to the present invention is a light-shielding device mounted on a cylinder having two or more protrusions provided on the outer peripheral surface, and is provided concentrically on the outer peripheral side of the cylinder, and the protrusions are engaged with each other. Two or more guide grooves are formed on the inner peripheral surface, provided with a light-shielding ring having a light-shielding member for shielding a part of light incident on the cylinder, and each projection moves along each guide groove, thereby shielding the light. The ring is movable relative to the cylinder, and each guide groove is provided with a recessed portion further recessed from the guide groove. When the protrusion is engaged with the guide groove, the light shielding ring is When pressed from the inside in the radial direction to the outside, the portion between the projections of the light shielding ring is deformed so as to bend inward in the radial direction, and the portion between the projections comes close to the cylinder, so that the projection is detached from the guide groove. As well as protrusions in the recesses When brought together, the pressing force to the light shielding ring is weakened from the projection, characterized in that the shielding ring is brought into click-stop.

  In the light-shielding device according to the present invention, when the projections are to be detached from the slide groove, the portion between the projections of the light-shielding ring comes into contact with the lens barrel and tightens the lens barrel, thereby preventing the light-shielding ring from being detached from the lens barrel. . Therefore, the direction in which the slide groove extends can be selected as appropriate, and for example, a contact device that can slide the light-shielding ring can be provided by any method of rotational movement and linear movement.

  Hereinafter, embodiments according to the present invention will be described with reference to the drawings. 1 and 2 are perspective views of binoculars to which the light shielding device of this embodiment is applied. As shown in FIGS. 1 and 2, the binoculars 10 are a pair of bilaterally symmetric lenses in which the optical axes of the pair of eyepieces 12 are decentered by a predetermined amount with respect to the optical axes of the pair of objective optical systems 11. Consists of a telephoto optical system. A prism (not shown) is provided between each objective optical system 11 and the eyepiece 12, and the optical axis of each objective optical system 11 is decentered by these prisms. The eyepiece unit 12 is provided with an eye contact device 20 as a light shielding device, and the eye contact device 20 can slide relatively parallel to the optical axis in the eyepiece portion 12.

  FIG. 3 shows a cross-sectional view of one eyepiece 12. The eyepiece unit 12 includes a first eyepiece lens group 21 provided on the eyepiece side and a second eyepiece lens group 22 provided on the objective side. The first and second lens groups 21 and 22 are held by first and second lens frames 23 and 24, respectively. In FIG. 3, for the sake of simplicity, the first and second eyepiece lens groups 21 and 22 are shown as a single optical member.

  First and second eyepiece lens barrels 25 and 26 are provided on the outer peripheral sides of the first and second lens frames 23 and 24, respectively. The first eyepiece lens barrel 25 is provided with screw portions 30 and 31 on the inner peripheral surface of the end portion on the eyepiece side and the outer peripheral surface of the end portion on the objective side. Similarly, a screw portion 32 is also provided on the inner peripheral surface of the second eyepiece lens barrel 26 on the eyepiece side, and the screw portion 32 is a screw provided on the objective side of the first eyepiece lens barrel 25. The first and second eyepiece lens barrels 25 and 26 are connected to each other by being screwed into the portion 31. Further, when the screw portions 31 and 32 are screwed together, the locking portion 33 provided on the second lens frame 24 is sandwiched between the first and second eyepiece lens barrels 25 and 26, thereby The second lens frame 24 is fixed to the first and second eyepiece lens barrels 25 and 26.

  The first lens frame 23 is provided with a screw portion 35 on the outer peripheral surface thereof, and this screw portion 35 is screwed to a screw portion 30 provided on the eyepiece side of the first eyepiece lens barrel 25, thereby The first lens frame 23 is fixed to the first eyepiece lens barrel 25.

  The eye contact device 20 in this embodiment includes the first eyepiece lens barrel 25 and an eye contact ring (light-shielding ring) 36 described above. The first eyepiece lens barrel 25 and the eye ring 36 are provided concentrically around the optical axis X of the first and second eyepiece lens groups 21 and 22, and the eye ring 36 is the first eyepiece lens. The lens barrel 25 is provided by being inserted into the outer peripheral surface. A fitting rubber portion 37 made of an elastic member such as rubber is further fitted on the outer circumferential surface of the fitting ring 36. A part of the eye ring 36 has a function as a light shielding member for shielding unnecessary light out of the light incident on the first eyepiece lens group together with the eye rubber part 37. Note that the first eyepiece lens barrel 25 and the eye ring 36 are made of, for example, a synthetic resin, and the eye ring 36 can be elastically deformed.

  FIG. 4 is an exploded perspective view of the aiming device according to the present embodiment. As shown in FIG. 4, the first eyepiece lens barrel 25 is provided with three projections 40, while the guide ring 36 is provided with three guide grooves 41 on the inner peripheral surface thereof. The projections 40 are respectively engaged, whereby the eye ring 36 is inserted into the first eyepiece lens barrel 25 so as to be slidable in the optical axis X direction.

  Each guide groove 41 is provided with a plurality of recessed portions 45 </ b> A to 45 </ b> D that are further recessed from the guide groove 41. When the protrusion 40 is engaged with any one of the recessed portions 45A to 45D, the eye ring 35 is click-stopped.

  The guide groove 41 extends in parallel with the optical axis X, and has a linear groove 42 whose one end is connected to the eyepiece side opening 41A, and a spiral branching from the linear groove 42 at a substantially central portion of the linear groove 42. It consists of a slide groove 43. The spiral slide groove 43 extends spirally in an oblique direction with respect to the optical axis X from the one opening 41A toward the other opening 41B.

  Recessed portions 45A and 45B that are further recessed from the straight groove 42 are provided at the branch position with respect to the spiral slide groove 43 and the end portion on the objective side in the straight groove 42, respectively. Also in the spiral slide groove 43, recessed portions 45C and 45D are provided at approximately the center position and the tip position in the extending direction, respectively. The recessed portions 45B and 45D are provided on the same circumference in the eye ring 36. The straight groove 42 includes an introduction groove 42A extending from the end on the opening 41A side to the recessed portion 45A, and a slide groove 42B extending from the recessed portion 45A to the other end.

  The guide grooves 41 are arranged at equal intervals in the circumferential direction of the eye ring 36, and the guide grooves 41 have the same configuration. The protrusions 40 are also arranged at equal intervals in the circumferential direction. Accordingly, the protrusion 40 is introduced from the opening 41A into the linear slide groove 42B or the spiral slide groove 43 (hereinafter, the linear slide groove 42B and the spiral slide groove 43 are collectively referred to as “slide grooves 42B and 43”) through the introduction groove 42A. Then, each projection 40 is engaged with the same position of each slide groove 42B, 43 in the circumferential direction. That is, when one protrusion 40 is engaged with a predetermined position of the slide grooves 42B and 43, the other two protrusions 40 are also engaged with predetermined predetermined positions of the slide grooves 42B and 43. When one protrusion 40 is engaged with the recess 45A, the other two protrusions 40 are also engaged with the recess 45A.

  Each protrusion 40 introduced into the linear slide groove 42B is displaced along the linear slide groove 42B, so that the eye ring 36 slides in the direction of the optical axis X relative to the first eyepiece lens barrel 25. It is movable. Further, as each projection 40 is displaced along the spiral slide groove 43, the eye ring 36 rotates around the first eyepiece lens barrel 25 relative to the first eyepiece lens barrel 25. While being slidable in the optical axis X direction.

  FIG. 5 is a longitudinal sectional view schematically showing the protrusion 40 and the guide groove 41. In FIG. 5, the left side in the drawing from the recessed portion 45 </ b> A schematically displays the vertical cross-sectional views of the spiral slide groove 43 and the linear slide groove 42 </ b> B. FIG. 6 shows a cross-sectional view along the line VV in FIG. 5 and 6, the guide groove 41 is indicated by a solid line, and the protrusion 40 is indicated by a one-dot broken line. A dotted line and a two-dot chain line indicate a virtual line.

  The introduction groove 42A includes a parallel groove 42C extending in parallel with the optical axis X from the opening 41A, and a tapered groove 42D connected to the parallel groove 42C and extending in the optical axis X direction while being inclined toward the inner diameter side. The transverse shape of the inner peripheral surface of the parallel groove 42C is an arc shape having a radius of curvature R1, and the central angle of the arc is 90 ° or more and 180 ° or less. The optical axis distance from the optical axis X of the groove tip portion of the parallel groove 42C is the distance φ0. Further, the optical axis distance of the tip portion of the projection 40 described later is φ1 (<φ0). In the following description, the optical axis distance refers to the distance from the optical axis X unless otherwise specified.

  The tapered groove 42D has an arc shape in which the cross-sectional shape of the inner peripheral surface thereof has a curvature radius R1, and the central angle of the arc is not less than 10 ° and not more than 180 °. When operating with human fingers as in the present embodiment, it is desirable that the angle is 30 ° or more and 45 ° or less. The optical axis distance of the groove front end portion becomes smaller as it approaches the recessed portion 45A, and the optical axis distance of the groove front end portion becomes a distance φ4 (φ4 <φ1) immediately before the connection portion with the recessed portion 45A.

  As described above, the linear slide groove 42B is connected to the taper groove 42D in the direction of the optical axis X on the objective side, and the spiral slide groove 43 is connected to the right side in FIG. As shown in FIG. 6, the linear slide groove 42 </ b> B and the spiral slide groove 43 have an inner circumferential surface having an arc shape with a curvature radius R <b> 1 (that is, the same curvature radius as that of the introduction groove 42 </ b> A). The central angle is 90 ° or more and 180 ° or less. The optical axis distance of the groove tip is a distance φ3 (third distance) as shown in FIG. 5, and the distance φ3 is smaller than the distance φ1 and larger than the distance φ4.

  The recessed portion 45A is further recessed from the slide grooves 42B and 43, and has an inner peripheral surface made of a concave spherical surface having a radius of curvature R2 (R2 <R1) and an arc angle of a central angle smaller than 180 °. The optical axis distance of the tip of the recessed portion 45A is the distance φ2, and the distance φ2 (second distance) is larger than the distances φ4 and φ3 and smaller than the distance φ1.

  The projection 40 provided on the eye ring 36 has a convex spherical surface with an outer peripheral surface having a central angle of arc smaller than 180 °, and the radius of curvature R3 of the outer peripheral surface is smaller than the radius of curvature R1 and larger than the radius of curvature R2. (R2 <R3 <R1). Further, the tip of the protrusion 40 is separated from the optical axis X by the optical axis distance φ1. The center of curvature of the protrusion 40 is the same as the center of curvature of the recessed portion 45A, and the centers of curvature of the slide grooves 42B and 43 are closer to the optical axis X than the center of curvature of the protrusion 40.

  Next, the effect | action in this embodiment is demonstrated using FIGS. First, an operation when the eye ring 36 is inserted into the first eyepiece lens barrel 25 will be described. When the eye ring 36 is inserted into the first eyepiece lens barrel 25, in the present embodiment, as described above, the protrusion 40 extends from the end of the parallel groove 42C on the opening 41A side to the linear slide groove 42B. The inner concave portion 45A is introduced. Here, the introduction groove 42A has a radius of curvature R1 larger than the curvature radius R3 of the protrusion 40, and the optical axis distance φ0 of the groove tip of the parallel groove 42C is slightly larger than the optical axis distance φ1 of the tip of the protrusion 40. Since it is large, the protrusion 40 is introduced into the parallel groove 42C without resistance. Next, in the tapered groove 42D, the optical axis distance is gradually reduced. Therefore, the protrusion 40 is pushed by a certain amount of pressing force, so that the first eyepiece lens barrel 25 is moved from the inner peripheral side to the radially outer side. While being expanded and elastically deformed, it passes through the tapered groove 42D and is moved to the recessed portion 45A, whereby the eye ring 36 is inserted into the first eyepiece lens barrel 25. The portion of the taper groove 42D adjacent to the recessed portion 45A has the optical axis distance of the groove tip portion shorter than the optical axis distance of the recessed portion 45A, so that the eye ring 36 is inserted into the first eyepiece lens barrel 25. Thereafter, the protrusion 40 is prevented from coming out of the introduction groove 42A. Further, since the optical axis distance φ2 of the tip of the recessed portion 45A is shorter than the optical axis distance φ1 of the tip of the protrusion 40, the protrusion 40 is recessed 45A by the elastic force in the radial direction by the first eyepiece lens barrel 25. Is pressed.

  Next, an operation when the protrusion 40 moves in the slide grooves 42B and 43 will be described. When the projection 40 is engaged with the slide grooves 42B and 43, the tip 40 of the projection 40 comes into contact with the groove tip portion B1 of the slide grooves 42B and 43, but the other outer peripheral surface of the projection 40 is the slide groove 42B. , 43 does not contact. That is, when the protrusion 40 engages with the slide grooves 42B and 43, only one point at the tip thereof contacts the slide grooves 42B and 43. This is because the curvature radius R3 of the protrusion 40 is smaller than the curvature radius R1 of the slide grooves 42B and 43.

  On the other hand, when the protrusion 40 is engaged with the recess 45A, the tip T of the protrusion 40 does not contact the tip of the recess 45A, but the outer peripheral surface S1 of the protrusion 40 is in contact with the inner peripheral surface S2 of the recess 45A. Abut. That is, when the protrusion 40 is engaged with the recessed portion 45A, the outer peripheral surface S1 of the protrusion 40 comes into contact with the slide grooves 42B and 43 by line contact. This is because the radius of curvature R3 of the protrusion 40 is larger than the radius of curvature R2 of the recessed portion 45A.

  In this way, when the projection 40 engages with the slide grooves 42B and 43, the slide groove 42B and 43 come into contact with the slide grooves 42B and 43 only at one point (the tip portion of the projection 40). 42B and 43 can be moved. On the other hand, when the protrusion 40 is engaged with the recess 45A, the inner peripheral surface S2 of the recess 45A is in contact with the outer peripheral surface S1 of the protrusion 40 by line contact, so the protrusion 40 is in contact with the recess 45A. Stable support.

  Further, the protrusion 40 has an optical axis distance φ1 at the tip thereof larger than an optical axis distance φ2 at the tip of the recessed portion 45A and an optical axis distance φ3 at the tips of the slide grooves 42B and 43. Therefore, when the protrusion 40 engages with the recessed portion 45A and the slide grooves 42B and 43, the eye ring 36 is pressed in the radial direction with a constant force. The pressing force of the protrusion 40 is greater when the protrusion 40 is engaged with the slide grooves 42B and 43 than when the protrusion 40 is engaged with the recessed portion 45A. This is because the optical axis distance φ2 at the front end of the recessed portion 45A is larger than the optical axis distance φ3 at the groove front ends of the slide grooves 42B and 43. Accordingly, an appropriate operational feeling when the user operates the eye ring 36 is given, and the position of the eye ring 36 is sensibly recognized.

  Further, the radius of curvature R1 inside the tapered groove 42D is larger than the radius of curvature R3 of the protrusion 40. Therefore, when the protrusion 40 is engaged with the tapered groove 42D, the protrusion 40 is in contact with the tapered groove 42D only at one point (the tip portion of the protrusion 40), similarly to when the protrusion 40 is engaged with the slide grooves 42B and 43. Even if a large force is not applied, the taper groove 42D can be moved.

  FIG. 7 is a schematic plan view of the first eyepiece lens barrel 25 and the eye ring 36 when the three protrusions 40 are engaged with the slide grooves 42B and 43 at the same position. The action when the protrusion 40 engages with the slide grooves 42B and 43 will be described in more detail with reference to FIG.

  As shown in FIG. 7, when each protrusion 40 engages with the slide grooves 42B and 43 and a pressing force F1 is applied to the eye ring 36 radially outward, the eye ring 36 is elastically deformed. The pressed parts P1 are bent so as to swell outward in the radial direction. When each part P1 of the eye ring 36 is bent outward, the part P2 of the eye ring 36 located between the parts P1 is bent radially inward. When each portion P2 is bent inward, the inner peripheral surface of the portion P2 comes close to the outer peripheral surface of the first eyepiece lens barrel 25.

  On the other hand, when the projection 40 is to be detached from the slide grooves 42B and 43 (that is, when the projection 40 is moved to the inner peripheral surface of the eye ring 36 without the guide groove 41), the projection 40 has a pressing force larger than the pressing force F1. The pressure is applied to the target ring 36. This is because the tip of the protrusion 40 tends to move to the portion of the eye ring 36 having a shorter optical axis distance. In this case, due to the large pressing force applied to the eye ring 36, the portion P2 of the eye ring 36 is further bent radially inward, and the inner peripheral surface of the part P2 of the eye ring 36 is the first eyepiece lens barrel. 25, the first eyepiece lens barrel 25 is fastened by the eye ring 36.

  That is, when the projection 40 is to be detached from the slide grooves 42B and 43, the first eyepiece lens barrel 25 is tightened by the eye ring 36 and the projection 40 cannot move, so that the projection 40 is detached from the slide grooves 42B and 43. Is prevented.

  Even when each of the protrusions 40 is engaged with the recessed portion 45A, the same phenomenon occurs because each protrusion 40 presses the eye ring 36. However, when the protrusion 40 is engaged with the recess 45A, the pressing force with which the protrusion 40 presses the eye ring 36 is smaller than when the protrusion 40 is engaged with the slide grooves 42B and 43. The amount of deflection is also reduced.

  Therefore, when the projection 40 is engaged with the recessed portion 45A, the pressing force from each portion P2 of the eye ring 36 to the first eyepiece lens barrel 25 is greater than when the projection 40 is engaged with the slide grooves 42B and 43. F2 becomes relatively small. Further, as described above, the protrusion 40 is stably supported by the inner peripheral surface S2 of the recessed portion 45A in the recessed portion 45A (see FIG. 6). That is, when the projection 40 is moved from the recessed portion 45A to the slide grooves 42B and 43, a larger force is required than when the projection 40 is moved in the slide grooves 42B and 43. As a result, the protrusion 40 is clicked by the recessed portion 45 </ b> A and clicked.

  Similarly, when the protrusion 40 engages with a part of the tapered groove 42D (that is, a part close to the recessed part 45A and the optical axis distance is smaller than the distance φ1), the eye ring 36 is pressed by the protrusion 40. Then, the portion between the projections 40 of the eye ring 36 is deformed so as to bend radially inward, and the portion between the projections 40 comes close to the first eyepiece lens barrel 25, so that the projection 40 is detached from the tapered groove. This is prevented (see FIG. 7).

  As described above, the protrusion 40 can freely move in the slide grooves 42B and 43 and the tapered groove 42D by the action of a relatively small force, whereas the protrusion 40 can be moved in the grooves 42B and 43. , 42D becomes unmovable due to tightening of the eye ring 36. Therefore, the protrusion 40 can smoothly move in the slide grooves 42B and 43 and the taper groove 42D, and separation from the grooves 42B, 43 and 42D is effectively prevented.

  That is, in the present embodiment, the protrusion 40 moves reliably along the slide grooves 42B and 43, and therefore, when adjusting the position of the eye contact device 20, an unnecessary large force is applied to the eye contact ring 36. However, the protrusion 40 does not ride on the outside of the groove. Therefore, in the present embodiment, the aiming device 20 can be reliably moved. Moreover, since it can move reliably along the taper groove 42 </ b> D, the eye ring 36 can be reliably inserted into the first eyepiece lens barrel 25.

  Further, the protrusion 40 can be freely moved with a small force in both the slide groove 42B extending parallel to the optical axis and the slide groove 43 extending spirally. Accordingly, the eye ring 36 of the present embodiment can move in the optical axis direction even when the protrusion 40 moves in either the circumferential direction or the optical axis direction.

  In the above description, only the concave portion 45A has been described as the concave portion, but the other concave portions 45B, 45C, and 45D have the same configuration.

  Although not particularly limited, for example, the optical axis distance φ0 of the tip of the parallel groove is 10.1 mm, the optical axis distance φ1 of the tip of the protrusion 40 is 10.0 mm, and the curvature radius R3 of the outer peripheral surface is 1.1 mm, the optical axis distance φ3 of the tip portions of the slide grooves 42B and 43 is 9.8 mm, the radius of curvature R1 of the inner peripheral surface thereof is 1 mm, and the optical axis distance φ2 of the tip portion of the recessed portion is 9 mm. .9 mm, and the radius of curvature R2 of its inner peripheral surface is 0.9 mm.

  Next, a second embodiment of the present invention will be described with reference to FIGS. The second embodiment is an example when the light-shielding device according to the present invention is applied to a lens hood provided at the tip of a lens barrel of a photographing lens.

  The light-shielding device according to the present embodiment is a lens hood that is attached to the front end of a photographing lens of a camera, and includes a lens barrel 125 for holding the photographing lens and a light-shielding ring 136 that includes the lens hood. The lens barrel 125 and the light shielding ring 136 are provided concentrically around the optical axis X of a photographing lens (not shown) held by the lens barrel 125, and the light shielding ring 136 is an outer peripheral surface of the lens barrel 125. It is provided by being inserted into. The lens barrel 125 and the light shielding ring 136 are made of, for example, synthetic resin, and the light shielding ring 136 can be elastically deformed.

  The lens barrel 125 is connected to the barrel main body 125a, the tip end side of the barrel main body 125a, and has a first barrel tip 125b having a smaller diameter than the barrel main body 125a, and a first barrel tip 125b. And a second lens barrel tip 125c having a smaller diameter than the first lens barrel tip 125b. The light shielding ring 136 includes an annular mounting portion 136a for mounting on the lens barrel 125, and a lens hood 136b connected to the distal end side of the mounting portion 136a. The lens hood 136b is a light shielding member for shielding a part of light incident on the photographing lens.

  Three protrusions 140 are provided on the outer peripheral surface of the second lens barrel tip 125c, and three guide grooves 141 are provided on the inner peripheral surface of the attachment portion 136a. Each protrusion 40 is provided in each guide groove 141. The light shielding ring 136 is attached to the lens barrel 125 by engaging with each other.

  The guide groove 141 extends in parallel with the optical axis X of the photographing lens, and has one end connected to the parallel groove 142 connected to the opening 141A on the rear side, and the other end of the parallel groove 142. And a circumferential groove 143 extending in the circumferential direction of 136a. A concave portion 145 that is further recessed from the circumferential groove 143 is provided at the tip of the circumferential groove 143.

  As in the first embodiment, the guide grooves 141 have the same configuration and are arranged at equal intervals in the circumferential direction of the light shielding ring 136, and the protrusions 140 are also arranged at equal intervals in the circumferential direction. For example, when one protrusion 140 is engaged with the recess 145, the other two protrusions 140 are also engaged with the recess 145.

  FIG. 10 is a schematic cross-sectional view for illustrating the configuration of the guide groove of the second embodiment. Although the circumferential groove 143 originally extends in the circumferential direction of the mounting portion 136a, it is schematically shown in FIG. 10 so as to extend in the optical axis direction.

  As shown in FIG. 10, the protrusion 140 has the same configuration as the protrusion 40 of the first embodiment, the optical axis distance from the tip portion to the optical axis X is φ1, and the outer peripheral surface has a central angle. It has a convex spherical surface whose arc degree is smaller than 180 °, and the radius of curvature of its outer peripheral surface is R3.

  The parallel groove 142 is a groove extending from the opening 141A in parallel with the optical axis X, and has the same configuration as the parallel groove 42C of the first embodiment. That is, the optical axis distance from the groove tip to the optical axis X is φ0 (> φ1), and the cross-sectional shape of the inner peripheral surface thereof is an arc shape with a radius of curvature R1, and the central angle of the arc is 10 °. It is 180 ° or less and preferably 30 ° or more and 45 ° or less.

  The circumferential groove 143 is a tapered groove, and has the same configuration as the tapered groove 42D of the first embodiment. That is, the cross-sectional shape of the inner peripheral surface of the circumferential groove 143 is an arc shape with a radius of curvature R1, and the central angle of the arc is 10 ° to 180 °, preferably 30 ° to 45 °. The optical axis distance of the groove tip portion of the circumferential groove 143 becomes smaller as it approaches the recessed portion 145, and immediately before the connecting portion with the recessed portion 145, the optical axis distance of the groove tip portion is the distance φ4 (φ4 <φ1). )

  The recessed portion 145 has the same configuration as each recessed portion of the first embodiment, and has an inner peripheral surface made of a concave spherical surface having a radius of curvature R2 (R2 <R1) and an arc angle of a central angle smaller than 180 °. . The optical axis distance φ2 at the tip of the recessed portion 145 is larger than the distance φ4 and smaller than the distances φ0 and φ1. In addition, the curvature radius R3 of the outer peripheral surface of the protrusion 140 is smaller than the curvature radius R1 and larger than the curvature radius R2 (R2 <R3 <R1).

  In the configuration as described above, the protrusion 140 is engaged with the recess 145 through the parallel groove 142 and the circumferential groove 143. Here, as in the first embodiment, when the projection 140 passes through the circumferential groove 143, the projection 140 contacts the circumferential groove 143 at only one point (the tip portion of the projection 140). Even if it does not act, it can move in the circumferential groove 143. On the other hand, when the protrusion 40 engages with the recessed portion 145, the inner peripheral surface of the recessed portion 145 contacts the protrusion 140 by line contact, so that the protrusion 40 is stably supported by the recessed portion 45A.

  Further, as in the first embodiment, when the protrusion 140 engages with the circumferential groove 143, the protrusion 140 presses the mounting portion 136a radially outward and elastically deforms, whereby the mounting portion 136a is radially inward. Bend. When the mounting portion 136a is bent inward, the portion between the guide grooves 141 on the inner peripheral surface of the mounting portion 136a is close to the outer peripheral surface of the second barrel tip 125c, and is the same as in the first embodiment. Thus, the protrusion 140 is prevented from being detached from the circumferential groove 143 (see FIG. 7).

  Further, when the protrusion 140 engages in the recessed portion 145, the pressing force from the protrusion 140 to the mounting portion 136a is weakened, and the protrusion 140 contacts the inner peripheral surface of the recessed portion 145 by line contact as described above. Therefore, as in the first embodiment, the light-shielding ring 136 is click-stopped by the lens barrel 125.

  Further, since the optical axis distance φ4 immediately before the connection portion of the circumferential groove 143 with the concave portion 145 is smaller than the optical axis distance φ2 of the tip portion of the concave portion 145, the force that is applied in the normal use state is applied to the light shielding ring 136. Even if acted, the protrusion 140 does not move from the recessed portion 145 to the circumferential groove 143.

  As described above, also in the second embodiment, when the projection 140 is engaged in the recessed portion 145, the light shielding ring 136 is click-stopped by the lens barrel 125, so that the light shielding ring 136 is stabilized to the lens barrel 125. Can be attached. Further, the protrusion 140 moves smoothly in the circumferential groove 136 and is prevented from being detached from the circumferential groove 136, so that the light shielding ring 136 can be securely attached to the lens barrel 125.

  In this embodiment, since the slide grooves 42B and 43 are not provided as in the first embodiment, the protrusion 140 engages with the recessed portion 145, and the light shielding ring 136 is inserted into the lens barrel 125. Thereafter, the light-shielding ring 136 cannot slide relative to the lens barrel 125. However, also in the second embodiment, a slide groove may be provided in the same manner as in the first embodiment, and the slide movement may be performed even after the light shielding ring 136 is fitted. In this case, for example, the protruding state of the lens hood 136b can be adjusted in accordance with the lens magnification of the photographing lens.

It is the perspective view which looked at the binoculars with which the aiming apparatus of this embodiment is applied from the front side. It is the perspective view which looked at the binoculars with which the aiming apparatus of this embodiment is applied from the back side. It is sectional drawing of an eyepiece part. It is a disassembled perspective view of an eyepiece apparatus. It is a longitudinal cross-sectional view which shows a protrusion and a guide groove typically. It is a cross-sectional view on the VV line in FIG. It is a typical top view when the 1st eyepiece lens barrel is inserted by the eye ring. It is a disassembled perspective view of the light-shielding device which concerns on 2nd Embodiment. It is sectional drawing of the light shielding ring which concerns on 2nd Embodiment. It is typical sectional drawing for showing the structure of the guide groove of 2nd Embodiment.

Explanation of symbols

20 Aiming device (shading device)
25 First eyepiece lens barrel (lens barrel)
36 Eye ring 40, 140 Protrusion 41, 141 Guide groove 42 Linear groove 42A Introducing groove 42B Linear slide groove 42C, 142 Parallel groove 42D Taper groove 43 Spiral slide groove 45A, 45B, 45C, 45D, 145 Recessed portion 125 Lens barrel 136 Shading ring 143 Circumferential groove (tapered groove)
φ1 First distance φ2 Second distance φ3 Third distance R1 Curvature radius of guide groove R2 Curvature radius of recess R3 Curvature radius of protrusion

Claims (10)

A lens barrel that houses the optical member and has two or more protrusions on its outer peripheral surface;
Two or more guide grooves provided concentrically on the outer peripheral side of the lens barrel and engaged with each of the protrusions are formed on the inner peripheral surface to block part of the light incident on the optical member. A light shielding ring having a light shielding member,
When the projections move along the guide grooves, the light-shielding ring can move relative to the lens barrel, and the guide grooves are further radially outward from the guide grooves. There is a recessed part recessed in
When the protrusion is engaged with the guide groove, the light shielding ring is pressed by the protrusion from the radially inner side to the outer side, and the portion between the protrusions of the light shielding ring is deformed to be bent radially inward, While the portion between the protrusions is close to the lens barrel, the protrusion is prevented from detaching from the guide groove,
When the projection is engaged in the recessed portion, a pressing force from the projection to the light shielding ring is weakened, and the light shielding ring is click-stopped. The first distance from the central axis of the barrel to the distal end of the projection, the third second distance from said central axis to a tip portion of the recessed portion, and from the central axis to the distal end of the guide groove The light-shielding device according to claim 1, wherein the light-shielding device is larger than the distance.   The light-shielding device according to claim 2, wherein the second distance is larger than the third distance.   The light shielding device according to claim 1, wherein an inner peripheral surface of the recessed portion, an inner peripheral surface of the guide groove, and an outer peripheral surface of the protrusion are formed of curved surfaces.   The inner peripheral surface of the recessed portion, the inner peripheral surface of the guide groove, and the outer peripheral surface of the protrusion are each composed of a curved curved surface, and the radius of curvature of the outer peripheral surface of the protrusion is the radius of curvature of the inner peripheral surface of the recessed portion. The light shielding device according to claim 4, wherein the light shielding device is larger and smaller than a radius of curvature of an inner peripheral surface of the guide groove.   The outer peripheral surface of the protrusion is formed of a convex spherical surface, the inner peripheral surface of the recessed portion is formed of a concave spherical surface, and the inner peripheral surface of the guide groove has an arc shape with a circumferential angle of 10 ° to 180 °. The light-shielding device according to claim 5. Before SL Each guide groove, at least, straight grooves parallel to extend linearly to the central axis of the lens barrel, the circumferential grooves extending in a circumferential direction of the shielding ring, or spirally oblique direction with respect to the central axis The light shielding device according to claim 1, further comprising a spiral groove extending.   The light shielding device according to claim 7, wherein each guide groove includes the linear groove and the spiral groove connected to the linear groove. Before SL guide groove, said projection and includes a tapered groove for introducing the one opening of the light shielding ring in the recess, the distance from the tip of the tapered groove to the center axis of the barrel the opening The light-shielding device according to claim 1, wherein the light-shielding device gradually decreases from the side toward the recessed portion. A light-shielding device mounted on a cylinder having two or more protrusions on an outer peripheral surface,
A light shielding member that is provided concentrically on the outer peripheral side of the cylinder and has two or more guide grooves formed on the inner peripheral surface with which the protrusions are engaged, and shields part of light incident on the cylinder. A shading ring having
When the projections move along the guide grooves, the light-shielding ring can move relative to the cylinder, and the guide grooves are further radially outward from the guide grooves. While a recessed recess is provided,
When the protrusion is engaged with the guide groove, the light shielding ring is pressed by the protrusion from the radially inner side to the outer side, and the portion between the protrusions of the light shielding ring is deformed so as to bend radially inward. The portion between the protrusions is close to the cylinder, thereby preventing the protrusions from separating from the guide grooves,
When the projection is engaged in the recessed portion, a pressing force from the projection to the light shielding ring is weakened, and the light shielding ring is click-stopped.

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