JP2016177228A - Optical apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical apparatus capable of preventing degradation of optical performance.SOLUTION: A lens barrel 1 includes: a plurality of optical elements 2; a movable ring 3 that holds the plurality of optical elements 2; a linear guide cylinder 7 which has a straight groove 7a for guiding a linear movement of the movable ring 3; and a cam cylinder 5 that has a cam groove 6 for regulating the movement of the movable ring. The movable ring moves in a light axial direction according to the rotation of the cam cylinder or the linear guide cylinder. The movable ring includes: a cam follower 4 that engages with the straight groove and the cam groove; and a projection 8 capable of coming into contact with the cam groove.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a lens barrel, a lens-integrated imaging device, and an optical apparatus such as an imaging system having an imaging device to which the lens barrel and the lens barrel can be attached.

  In a lens barrel having a moving ring that holds the optical element movably through the cam groove and the cam follower, the cam groove and the cam follower are disconnected from each other when impact is applied, the cam groove dents, or the moving ring falls Degradation of the optical performance due to.

  Therefore, Patent Document 1 discloses a cam having a plurality of cam grooves each corresponding to each cam pin, having a moving ring in which metal cam pins and resin cam pins are alternately arranged in the circumferential direction, and cam loci having the same shape. A lens barrel having a ring is proposed. When the lens barrel receives an impact in a direction parallel to the optical axis, the resin cam pin disperses the impact force received by the metal cam pin, so that the cam groove can be prevented to some extent. Patent Document 2 proposes a lens device in which a cam follower that engages with a cam groove of a cam cylinder and a cam follower that engages with a spiral groove of a fixed cylinder are provided on an outer peripheral portion of a moving ring. When the lens barrel receives an impact parallel to the optical axis, the impact force is distributed to the contact point between the cam groove surface and the cam follower, and the contact point between the spiral groove surface and the cam follower, thereby preventing cam groove dents to some extent. can do.

JP 2009-258295 A JP 2014-153618 A

  In the lens barrel of Patent Document 1, when the impact force is increased, there is a possibility that a dent is generated in the cam groove. In Patent Document 2, since the positional accuracy of the spiral groove is lower than that of the rectilinear groove, the positional accuracy of the moving ring and thus the optical performance may be deteriorated.

  An object of the present invention is to provide an optical apparatus capable of suppressing dents and breakage of a cam groove and suppressing a decrease in optical performance.

  An optical element of the present invention includes an optical element, a moving ring that holds the optical element, a rectilinear guide tube having a rectilinear groove that guides the rectilinear movement of the moving ring, and a cam groove that defines the movement of the moving ring. An optical device in which the moving ring moves in the optical axis direction as the cam tube or the rectilinear guide tube rotates, and the moving ring includes the rectilinear groove or the cam groove. A cam follower that engages with at least one of the cam follower and a protrusion that is disposed on the at least one and reduces deformation of the cam follower or the at least one of the cam follower.

  ADVANTAGE OF THE INVENTION According to this invention, the optical apparatus which can suppress the dent and damage of a cam groove, and can suppress the fall of optical performance can be provided.

It is a fragmentary sectional view of the lens barrel of the present invention. Example 1 FIG. 2 is a development view of a straight advance groove, a cam groove, and a cam follower shown in FIG. 1. Example 1 It is a fragmentary sectional view of the lens barrel of the present invention. (Example 2) FIG. 4 is a development view of a straight advance groove, a cam groove, and a cam follower shown in FIG. 3. (Example 2)

  Embodiments of the present invention will be described below with reference to the accompanying drawings.

  FIG. 1 is a partial cross-sectional view of the lens barrel 1 of the first embodiment. In the figure, the left side is the subject side, and the right side is the imaging surface side. The lens barrel 1 is an optical device that houses a photographing optical system for forming a subject image, and O is an optical axis of the photographing optical system. The lens barrel 1 is detachably attached to a camera body (not shown). The camera body is an image pickup apparatus body that includes an image sensor that photoelectrically converts a subject image and includes a single-lens reflex camera, a non-flex single-lens reflex camera (mirrorless camera), and the like. The lens barrel 1 and the camera body constitute an imaging system.

  The lens barrel 1 includes an optical element 2, a moving ring 3, a cam follower 4, a cam cylinder 5, and a rectilinear guide cylinder 7, and the moving ring 3 moves in the optical axis direction of the photographing optical system as the cam cylinder 5 rotates. .

  The optical element 2 constitutes an optical system. The optical element 2 includes a focus lens group that moves in the optical axis direction to adjust the focus and a zoom lens group that moves in the optical axis direction to change the focal length. In this embodiment, the optical element 2 is a focus lens group. The optical element 2 is held directly on the moving ring 3.

  The moving ring 3 is a molded product made of a synthetic resin and is a substantially cylindrical member. Cam followers 4 are arranged on the moving ring 3 at intervals of 120 degrees. The cam follower 4 is a bearing formed of a stainless material.

  The cam cylinder 5 and the rectilinear guide cylinder 7 are substantially cylindrical members formed by cutting a metal such as aluminum or magnesium. Cam grooves 6 and cam groove surfaces 6a and 6b penetrating the cylindrical wall thickness are arranged on the cylindrical side surface portion of the cam cylinder 5 at intervals of 120 degrees. The cam groove 6 defines the movement of the moving ring 3. On the cylindrical side surface portion of the rectilinear guide tube 7, rectilinear grooves 7a parallel to the optical axis O are arranged at intervals of 120 degrees. The rectilinear groove 7 a guides the rectilinear movement of the moving ring 3.

  Since the cam follower 4 is disposed at the intersection of the rectilinear groove 7a and the cam groove 6, the cam follower 4 can be reduced in size, and it is difficult to apply force to the moving ring 3 in the circumferential direction or the oblique direction. For this reason, deformation and inclination hardly occur, and the positional accuracy of the optical element 2 is improved.

  A focus ring (not shown) and the cam cylinder 5 are connected, and the cam cylinder 5 rotates when the focus ring is rotated around the optical axis of the optical system. Further, due to the cooperative action of the cam cylinder 5 and the rectilinear guide cylinder 7, the moving ring 3 including the optical element 2 moves in the optical axis direction, and the focus adjustment can be performed.

  FIG. 2 is a development view of the rectilinear groove 7 a, the cam groove 6, the cam follower 4, and the protrusion 8 in the lens barrel 1. In addition, the up-down direction in the drawing indicates a direction parallel to the optical axis.

  A protrusion 8 is integrally formed on the moving ring 3, and the protrusion 8 is disposed in the cam groove 6. The protrusion 8 reduces deformation of at least one of the cam follower 4 and the cam groove 6 or the rectilinear groove 7a. A protrusion 8 and a cam follower 4 are disposed in the cam groove 6. The protrusion 8 has surfaces (planar portions) 8 a and 8 b facing the cam groove surfaces 6 a and 6 b that are sliding surfaces of the cam groove 6. The protrusion 8 is separated from the sliding surface of the cam groove 6 in a normal state (although it can contact the cam groove surfaces 6a and 6b) (in a state where the cam follower mounting portion of the cam follower 4 or the moving ring 3 is not deformed). .

  When the protrusion 8 is disposed adjacent to the cam follower 4, when either one of the cam follower mounting portion of the moving ring 3 or the cam follower 4 is deformed, the cam groove surface 6 a or the cam groove surface 6 b is brought into contact with the cam groove surface 6 b almost simultaneously with the deformation. It becomes easy and the load on the cam can be reduced. For this reason, in this embodiment, the protrusion 8 is disposed near the cam follower 4.

  Since the protrusion 8 is preferably less deformed when subjected to an impact, the thickness of the protrusion 8 in the direction perpendicular to the optical axis O in the cross section perpendicular to the optical axis O is half the thickness of the cam cylinder 5. As described above, the width in the circumferential direction is desirably half or more of the diameter of the cam follower 4. If each becomes less than half, the effect of the protrusion 8 is reduced, and there is a possibility that a dent is generated at the contact point B between the cam groove surface 6 a and the cam follower 4. Therefore, it is desirable that the thickness of the protrusion 8 in the direction perpendicular to the optical axis O is not less than half of the thickness of the cam cylinder, and the thickness in the circumferential direction is not less than half of the diameter of the cam follower 4.

  Next, the effect of preventing dents in the cam groove of the lens barrel 1 of this embodiment will be described. When the lens barrel 1 is dropped from the subject side in the direction A substantially parallel to the optical axis O, and the lens barrel 1 collides with the floor surface or the like and stops moving, the contact point B between the cam groove surface 6a and the cam follower 4 An impact force F1 is generated.

  At this time, the cam follower mounting portion or the cam follower 4 of the moving ring 3 which is a resin member is deformed. As a result, the surface 8a of the protrusion 8 that is separated in the normal state contacts the cam groove surface 6a, and the contact surface C is created. Since the impact force F2 is generated at the contact surface C and the impact force F1 can be reduced, the cam groove surface 6a and the cam follower 4 can be prevented from being deformed.

  Even if the moving ring 3 becomes heavy, it is possible to prevent dents in the cam groove without increasing the cam groove as in Patent Document 1 against an impact in the optical axis direction. In addition, since the present embodiment does not use a spiral groove as in Patent Document 2, it is possible to prevent a decrease in optical performance associated with the spiral groove during focus and zoom operations. In addition, even if it falls from the imaging surface side, the same effect is acquired by the relationship between the cam groove surface 6b, the cam follower 4, and the surface 8b of the protrusion 8.

  In this embodiment, the protrusion 8 is formed on the left side of the cam follower 4, but it may be formed on the right side or both sides of the cam follower 4, and the protrusion 8 may be a separate part. In this embodiment, the mechanism in which the moving ring moves in the optical axis direction along with the rotation of the cam cylinder has been described. However, the linear guide cylinder rotates and the moving ring moves in the optical axis direction along the cam groove of the cam cylinder. It is good also as a mechanism. In this embodiment, the lens barrel 1 has been described. However, the present invention can also be applied to an imaging apparatus (optical apparatus) in which the camera body and the lens barrel are integrated.

  FIG. 3 is a partial cross-sectional view of the lens barrel 11 of the second embodiment. As in FIG. 1, the left side is the subject side, the right side is the imaging surface side, and O is the optical axis. Hereinafter, the description will focus on the differences of the present embodiment from the first embodiment. The lens barrel 11 includes an optical element 22, a moving ring 33, a cam follower 44, a cam cylinder 55, a rectilinear guide cylinder 77, and a fixed cylinder 99, and the moving ring 33 moves in the optical axis direction as the cam cylinder 55 rotates. .

  A plurality of cam followers 44 are attached to the moving ring 33, and the cam followers 44 are engaged with the cam grooves 66 of the cam cylinder 55 and the rectilinear grooves 77 a of the rectilinear guide cylinder 77. A fixed cylinder 99 is provided on the outer periphery of the rectilinear guide cylinder 77 and is connected to the rectilinear guide cylinder 77. A spring (biasing means) 10 is provided between the moving ring 33 and the fixed cylinder 99, thereby urging the moving ring 33 toward the subject.

  A focus ring (not shown) and the cam cylinder 55 are connected, and the cam cylinder 55 rotates when the focus ring is rotated around the optical axis. By the cooperative action of the cam cylinder 55 and the rectilinear guide cylinder 77 and the bias of the spring 10, the moving ring 33 including the optical element 22 stably moves in the optical axis direction while sliding on the cam groove surface 66 a of the cam groove 66. Move and adjust the focus.

  4 is a development view of the rectilinear groove 77a, the cam groove 66, the cam follower 44, and the protrusion 88 in the lens barrel 11. As shown in FIG. In addition, the up-down direction in the drawing indicates a direction parallel to the optical axis.

  A protrusion 88 is integrally formed on the moving ring 33 and is disposed in the cam groove 66. The protrusion 88 reduces deformation of at least one of the cam follower 44 and the cam groove 66 or the rectilinear groove 77a. A protrusion 88 and a cam follower 44 are disposed in the cam groove 66. The protrusion 88 has a surface 88 a that faces the cam groove surface 66 a that is one sliding surface of the cam groove 66. The protrusion 88 is spaced from the sliding surface of the cam groove 66 in a normal state (although it can contact the cam groove surface 66a) (in a state where the cam follower 4 or the cam follower mounting portion of the moving ring 3 is not deformed).

When the protrusion 88 is disposed adjacent to the cam follower 44, when any one of the cam follower mounting portion of the moving ring 33 or the cam follower 44 is deformed, the cam 88 is easily brought into contact with the cam groove surface 66a almost simultaneously with the deformation. Can reduce the load.
For this reason, in this embodiment, the protrusion 88 is disposed near the cam follower 44.

  Since the projection 88 is preferably less deformed when subjected to an impact, the thickness of the projection 88 in the direction perpendicular to the optical axis O in the cross section perpendicular to the optical axis O is half the thickness of the cam cylinder 55. As described above, the width in the circumferential direction is desirably half or more of the diameter of the cam follower 4. If the ratio is less than half, the effect of the protrusion 88 is reduced, and there is a possibility that a dent is generated at the contact point BB between the cam groove surface 66a and the cam follower 44. Therefore, it is desirable that the thickness of the projection 88 in the direction perpendicular to the optical axis O is at least half of the thickness of the cam barrel, and the thickness in the circumferential direction is at least half of the diameter of the cam follower 44.

  Next, the effect of preventing dents in the cam groove of the lens barrel 11 of this embodiment will be described. When the lens barrel 11 is dropped from the subject side in the direction AA substantially parallel to the optical axis O, and the lens barrel 11 collides with the floor surface or the like and stops moving, the contact point BB between the cam groove surface 66a and the cam follower 44 An impact force FF1 is generated.

  At this time, either the cam follower mounting portion or the cam follower 44 of the moving ring 33 which is a resin member is deformed. As a result, the surface 88a of the protrusion 88 that is separated in the normal state contacts the cam groove surface 66a, and a contact surface CC is formed. Since the impact force FF2 is generated on the contact surface CC and the impact force FF1 can be reduced, deformation of the cam groove surface 66a and the cam follower 44 can be prevented.

  Even if the moving ring 3 becomes heavy, it is possible to suppress dents or breakage of the cam groove without increasing the cam groove as in Patent Document 1 against an impact in the optical axis direction. In addition, since the present embodiment does not use a spiral groove as in Patent Document 2, it is possible to prevent a decrease in optical performance associated with the spiral groove during focus and zoom operations.

  Note that the projection 88 may not come into contact with the cam groove surface 66b when dropped from the imaging surface side. However, the cam follower 44 slides when the moving ring 33 is urged by the spring 10 to the cam groove surface 66a. There is no problem because the groove surface 66a.

  In this embodiment, the protrusion 88 is formed on the left side of the cam follower 44, but it may be formed on the right side or both sides of the cam follower 44, and the protrusion 88 may be a separate part. In this embodiment, the mechanism in which the moving ring moves in the optical axis direction along with the rotation of the cam cylinder has been described. However, the linear guide cylinder rotates and the moving ring moves in the optical axis direction along the cam groove of the cam cylinder. It is good also as a mechanism. In the present embodiment, the lens barrel 1 has been described, but the present invention can also be applied to an imaging apparatus in which the camera body and the lens barrel are integrated.

  Examples 1 and 2 describe the effect when dropped from a direction substantially parallel to the optical axis. However, if the user accidentally drops the lens barrel while transporting the lens barrel, and the camera follower drops from a direction substantially perpendicular to the optical axis O, the cam follower comes into contact with the straight groove surface and an impact force is generated at the contact point. Become. In that case, as in the case of dropping from a direction substantially parallel to the optical axis O, the protrusions come into contact with the straight groove surface simultaneously with the cam follower, and the load on the contact point can be reduced, and the straight groove surface and the cam follower Deformation can be prevented.

  As described above, when the structure of the present invention is used, even when the moving ring becomes heavy, the cam groove is prevented from being dented or damaged against an impact such as dropping, and the optical performance is not used because the spiral groove is not used. Can be prevented. In the moving ring, the cam follower may be engaged with at least one of the rectilinear groove or the cam groove, and the protrusion may be disposed on at least one of the above.

  The preferred embodiments of the present invention have been described above, but the present invention is not limited to these embodiments, and various modifications and changes can be made within the scope of the gist.

  The optical apparatus of the present invention can be applied to the use of a lens barrel, a lens-integrated imaging device, and an imaging system having a lens barrel and an imaging device to which the lens barrel can be attached.

2, 22 ... optical element, 3, 33 ... moving ring, 4, 44 ... cam follower, 5, 55 ... cam cylinder, 6, 66 ... cam groove, 6a, 6b, 66a, 66b ... cam groove surface, 7, 77 ... Straight guide tube, 7a, 77a ... Straight groove, 8, 88 ... Projection

Claims (12)

An optical element; a moving ring that holds the optical element; a rectilinear guide cylinder having a rectilinear groove that guides the rectilinear movement of the moving ring; and a cam cylinder having a cam groove that regulates the movement of the moving ring. An optical device in which the moving ring moves in the optical axis direction as the cam cylinder or the rectilinear guide cylinder rotates.
The moving ring includes a cam follower that engages with at least one of the rectilinear groove or the cam groove, and a protrusion that is disposed on the at least one and reduces deformation of the cam follower or the at least one. Optical equipment.   The optical apparatus according to claim 1, wherein the protrusion is disposed adjacent to the cam follower.   The optical apparatus according to claim 1, wherein the cam follower is disposed at a crossing portion of the rectilinear groove and the cam groove.   The optical apparatus according to claim 1, wherein the protrusion has a surface facing the cam groove or the rectilinear groove.   The protrusion is spaced apart from the sliding surface of the cam groove and the rectilinear groove when the cam follower or the cam follower mounting portion of the moving ring is not deformed. The optical apparatus according to any one of the above.   6. The optical apparatus according to claim 5, wherein when the cam follower or a mounting portion of the cam follower of the moving ring is deformed, the protrusion can contact the at least one sliding surface.   The thickness in the direction perpendicular to the optical axis of the protrusion in a cross section perpendicular to the optical axis is not less than half of the thickness of the cam cylinder. The optical instrument described.   8. The optical apparatus according to claim 1, wherein in a cross section perpendicular to the optical axis, the circumferential width of the protrusion is at least half of the diameter of the cam follower. The protrusion can contact one sliding surface of two opposed sliding surfaces in the rectilinear groove or the cam groove,
The optical apparatus according to claim 1, further comprising a biasing unit that biases the cam follower toward the one sliding surface.   The optical apparatus according to claim 1, wherein the optical apparatus is a lens barrel that can be attached to an imaging apparatus.   The optical apparatus according to claim 1, wherein the optical apparatus is an imaging device. A lens barrel having the optical element, the linear guide cylinder, the cam cylinder and the moving ring;
An imaging device to which the lens barrel can be attached;
The optical apparatus according to claim 1, comprising: