JP2020034803A - Lens barrel - Google Patents

Abstract

To provide a lens which can be fixed at an arbitrary position in a non-step manner without bonding or providing different shapes on locking parts, and which is capable of solving the conventional problems that the adjustment position was fixed by bonding or the like after adjusting the lens rotation angle position relative to the holding barrel resulting in a problem in dismantling.SOLUTION: A tightening ring and a holding barrel are screwed together with each other, and an inclined part on the inner circumference of the tightening ring gradually presses an inclined part of the holding barrel; thereby a locking claw of the holding barrel is elastically deformed and urges a first lens to the abutting part in the optical axis direction to fix it.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a lens barrel having a lens that adjusts a rotational position so that the influence of an optical axis shift on other optical elements is reduced.

  Ideally, the lens is ideally completely rotationally symmetrical with respect to the optical axis, but in reality there is slight inclination or eccentricity of the optical axis due to manufacturing errors, etc., which are manufactured by molding. In the case of a lens, the inclination or eccentricity of the optical axis described above due to a manufacturing error often increases. When manufactured by a polishing process, the outer shape is cut in the centering process, so the eccentricity is reduced, so the axis deviation is relatively small, but when manufactured by molding, the accuracy of the mold itself, symmetry and upper mold, This is because the deviation of the optical axis is determined by the accuracy of the mechanical holding position of the lower mold.

  Furthermore, in the case of an aspherical lens, since the convergence position of the light beam passing through the center of the lens and the light beam passing through the periphery is controlled by changing the surface shape, the relative position with other optical elements becomes sensitive and the optical axis shifts The effect is even greater.

  Furthermore, when both surfaces are aspherical lenses, aberration correction is performed with high precision, and the influence of the optical axis shift on the final optical performance becomes even greater.

  Therefore, conventionally, in a lens barrel having a lens manufactured by molding, after adjusting the position of the optical axis with other optical elements, the adjustment position of the molded lens is fixed by bonding or welding. There was generally a lens barrel.

  Patent Literature 1 discloses a technique of adjusting the optical axis of each lens unit so as to minimize aberration, and then temporarily fixing the lens unit with a UV-curable adhesive, and permanently fixing the lens unit.

  Further, in Patent Document 2, the rotational position is adjusted by providing a convex or concave engaging portion for restricting rotation with respect to a lens barrel in a part of a molded lens, and the adjusted lens is held down by a holding ring. It is made to prevent entrainment by tightening.

JP-A-2002-62463 JP 2011-48123 A

  However, in the method of fixing the position after lens adjustment using an adhesive as disclosed in Patent Document 1, when it is necessary to disassemble the lens afterwards, it is not easy to disassemble itself, and it is difficult to reuse parts. Become.

  Next, in Patent Document 2, it is necessary to provide a part of the molded lens with an irregular shape of a convex or concave part serving as an engaging part, and the optical influence due to internal distortion during molding due to the irregular shape is required. I am concerned.

  Further, since the rotation holding position by the engagement portion is determined in a stepwise manner, there is a problem that even if there is an optimum position in the middle, the rotation holding position cannot be selected.

  Furthermore, even if the above-mentioned problems are encountered, it is possible to provide a locking shape when manufactured by molding, but it is difficult to provide a locking shape when manufactured by a polishing process. .

  It has been described that in the case of a lens manufactured by a polishing process, the optical axis deviation is relatively small. However, if the sensitivity of the optical system is high, there is a possibility that the deviation cannot be ignored.

  Therefore, an object of the present invention is to provide a lens for adjusting the rotational position with respect to the holding lens barrel without bonding or the like, and without providing a deformed shape such as a locking portion, and further, the adjusting position is not stepwise but stepless. An object of the present invention is to provide a lens barrel that can be fixed at an arbitrary position.

  In order to achieve the above object, according to the present invention, there is provided a lens barrel having at least one lens as an optical element, wherein the lens barrel includes a lens as an optical element and the lens. And a fastening ring attached to the holding barrel. The holding barrel includes a fitting portion for holding an outer shape of a lens, and an optical element including the lens in an optical axis direction. An abutting portion, and an engaging portion abutting on a curvature surface of the lens opposite to the abutting portion, wherein the engaging portion is connected by an elastic portion having a degree of freedom in an optical axis direction and a radial direction. The lens barrel is divided into multiple parts while changing the angular phase around the optical axis while being held, so that the locking part that abuts on the curvature surface of the lens holds the lens in contact with the lens barrel Part.

  In the present invention of claim 2, the fastening ring is screwed into the holding barrel so that the inner peripheral portion of the fastening ring presses the outer portion of the locking portion elastically connected to the holding barrel. 2. The lens barrel according to claim 1, wherein the locking ring presses the curvature surface of the lens by being elastically deformed in the inner circumferential direction and urges the lens surface in the optical axis direction. By screwing into the holding barrel, the locking portion urges the lens toward the contact portion in the optical axis direction and fixes the rotational phase position.

  Further, in the invention according to claim 3, the tightening ring has an inclined surface on an inner periphery, and biases the lens in an optical axis direction from an outer peripheral direction by pressing an outer peripheral portion of the holding barrel. With the lens barrel according to claim 1 or 2, the tightening of the tightening ring causes the elastic portion to fix the rotational phase position while urging the internal lens toward the contact portion in the optical axis direction. It was done.

  According to a fourth aspect of the present invention, the tightening ring has a wall that directly urges the elastic locking portion of the holding barrel in the optical axis direction while being screwed into the holding barrel. By adopting the lens barrel described in Items 1, 2, and 3, it is possible to secure a large urging force in the optical axis direction even when a lens having a large mass is held.

  According to the fifth aspect of the present invention, the holding barrel and the tightening ring are connected by screwing with a screw. The holding force of the lens on the holding barrel can be adjusted by adjusting the tightening torque of the ring.

  Further, in the present invention according to claim 6, the lens is an aspherical lens, and the lens barrel according to claims 1, 2, 3, 4, and 5 has an effect of an optical axis shift. Even when a lens manufactured by manufacturing a large mold is used, it is possible to hold the lens after adjusting the rotational phase position.

  Furthermore, in the present invention according to claim 7, the lens is a lens barrel according to any one of claims 1, 2, 3, 4, 5, and 6, wherein both surfaces are aspherical lenses. Even after using a lens manufactured by a mold production which is greatly affected by the axis deviation, it is possible to hold the lens after adjusting the rotational phase position.

  ADVANTAGE OF THE INVENTION According to the lens barrel which concerns on this invention, after performing an optical axis rotation phase position adjustment with respect to a holding | maintenance barrel, the position after adjustment can be fixed without relying on adhesion etc., and the effect that disassembly is also easy. is there.

Sectional view of a lens barrel embodying the present invention Exploded perspective view of a lens barrel embodying the present invention. 1 is a partially exploded perspective view of a lens barrel embodying the present invention. FIG. 2 is a partial cross-sectional view showing a state in which the first group unit embodying the present invention is being assembled. 1 is a perspective view of a first unit embodying the present invention. Partial sectional view at each sectional phase position indicated in FIG. Partial enlarged sectional view of a first group unit showing another embodiment.

  Hereinafter, a preferred embodiment of the present invention will be described with reference to the drawings, but the description will be limited to only the vicinity of the portion where the present invention is implemented in the lens barrel, and will not reach the details of other parts of the lens barrel.

  FIG. 1 is a sectional view of a lens barrel embodying the present invention, and FIG. 2 is an exploded perspective view of the lens barrel embodying the present invention. FIG. 3 is a partially exploded perspective view of a lens barrel embodying the present invention, and FIG. 4 is a partial cross-sectional view showing a state in which the first group unit embodying the present invention is being assembled.

  FIG. 5 is a perspective view of the first unit embodying the present invention with the first group tightening ring removed, and FIG. 6 is a partial sectional view at each sectional phase position shown in FIG.

  FIG. 7 is a partially enlarged cross-sectional view of a locking portion of the first lens barrel showing another embodiment.

  1 and 2, reference numeral 1 denotes a mount connected to a camera (not shown), reference numeral 3 denotes a fixed cylinder, and reference numeral 2 denotes a mount ring for adjusting the distance between the mount 1 and the fixed cylinder 3 by cutting and adjusting the thickness. Reference numeral 4 denotes a control board that is held by the fixed cylinder and controls the operation. Further, the control board 4 is provided with a contact block 4a for connecting to an electric contact on the camera side.

  Further, a guide tube 6 is connected to the fixed tube 3 and provided with a guide groove for guiding the moving group in a straight line. A guide tube 7 is held rotatably at a fixed position about the optical axis with respect to the guide tube 6, and rotates the light to move the moving group. This is a cam ring having a cam for moving in the axial direction. The cam ring 7 is incorporated from the front side with respect to the guide cylinder 6, and is engaged with the zoom ring 5 held by the fixed cylinder 3 so as to be rotatable at a fixed position around the optical axis by a zoom key 8.

  A first moving group 11, a second moving group 12, and a third moving group 13 whose positions in the optical axis direction are determined by engaging a cam follower at the intersection of the guide groove and the cam of the cam ring 7 in the guide cylinder 6. , The fourth moving group 14 and the fifth moving group 15 are held.

  The group unit 110 of the first moving group 11 will be described later in detail.

  The second moving group 12 is also a focus group for focus adjustment, and a second group unit 12d is held by a second group moving ring 12c and a focus cam ring 12b. Further, a sub-aperture A unit 12a for cutting unnecessary off-axis light is held in the second group moving ring 12c, and the aperture varies depending on the position of the second moving group in the optical axis direction.

  The fourth movable group 14 holds an electromagnetic diaphragm unit 14a, and is electrically connected to the control board 4 by a flexible printed wiring board 14b. More specifically, a flexible printed wiring board 14b electrically connects the drive motor on the electromagnetic aperture unit 14a, the photointerrupter for detecting the open state of the aperture blades of the aperture, and the control board 4 to each other.

  Further, a sub-aperture B unit 14c for determining Fno is held on the imaging direction side of the fourth movable group 14, and similarly to the sub-aperture A unit 12, the aperture varies depending on the position of the fourth movable group 14 in the optical axis direction. I do.

  The moving groups from the second moving group to the fifth moving group 15 are arranged on the inner diameter of the guide cylinder 6, while the first moving group 11 is arranged on the outer diameter side of the cam ring 7. The guide groove is held at the intersection of the cam groove of the cam ring 7.

  Further, the bayonet claw 16a of the deformation receiving member 16 is held on the object direction side of the guide cylinder 6 by engaging with the bayonet groove 6a of the guide cylinder. Be integrated. The deformation receiving member 16 is provided with a through hole 16a, and the leg 11c of the first group moving ring 11b of the first moving group 11 penetrates through the through hole 16a to engage with the guide cylinder 6 and the cam ring 7. I have. Further, a tape-shaped buffer member 17 made of an elastic material is arranged on the outer peripheral side of the deformation receiving member 16.

  Further, a relay ring 18 is rotatably held at a fixed position at the end of the guide cylinder 6 in the object direction, and the focus is adjusted by rotating the focus cam ring 12b via a connection key A19 and a connection key B20 attached to the relay ring 18. Therefore, the second moving group 12 moves in the optical axis direction. Since the connection key A is attached through one of the through holes 16A of the deformation receiving member 16, the operation range of the relay ring 18 is restricted, and the relay ring 18 rotates in a fixed position.

  An exterior unit 9 composed of a focus unit 9a and a front unit 9c is fixed to another phase portion where the guide cylinder 6 is connected to the fixed cylinder 3 at the rear end in the imaging direction, and a filter screw is attached to the front unit 9c. And a hood attachment section are provided.

  A gap A22 is provided between the inner diameter of the exterior unit 9 and the outer diameter of the deformation receiving member 16 so that the elastic buffer member 17 is slightly compressed and then brought into contact.

  Further, a focus ring 10 for manually operating the focus adjustment is held in the exterior unit 9 so as to be rotatable at a fixed position, and the rotational force can be transmitted to the focus unit 9a.

  Although not described in detail, the focus unit 9a is an annular vibration wave motor, and receives and drives a control signal and power from the control board 4. In addition to the electric drive by the electric control, the focus ring 10 is manually operated to engage with the connection key A19 held on the relay ring 18 via the focus key 9b, and further, the rotational force is applied from the connection key B20 to the focus cam. It is possible to transmit to the ring 12b.

  Next, the configuration of the first group unit 110 that holds the optical elements of the first moving group 11 will be described.

  FIG. 3 is an exploded perspective view of the first-group unit 110. The first-group lens barrel 113 includes a first lens 111 and a second lens 112, which are optical elements whose both optical surfaces are aspherically molded by a mold. It is held by the first group tightening ring 114. The first group lens barrel 113 and the first group tightening ring 114 are coupled by screwing, and a washer 115 for adjusting the distance between the lenses is inserted between the first lens 111 and the second lens 112.

  As will be described later, the first lens 111 and the second lens 112 abut on the first group lens barrel 113 with the washer 115 interposed therebetween in the optical axis direction, and are fixed by the locking portion 113b of the first group lens barrel 113 and the first group tightening ring 114. The first group unit 110 is held.

  The first group lens barrel 113 manufactured by resin molding has a fitting holding portion 113a for holding the outer diameter fitting portion 111a of the first lens 111, and a distal end with both ends of the elastic portion 113c extending in the circumferential direction. Are alternately and equally arranged at three locations.

  Although the locking portion 113b abuts on the front curvature surface of the first lens 111, since it is disposed at the tip of the elastic portion 113c, the degree of freedom due to elastic deformation not only in the radial direction from the optical axis center but also in the optical axis direction. have.

  Further, an inclined portion 113 d is provided on the outer diameter side of the locking portion 113 b of the first lens barrel 113, and an inclined surface 114 a is similarly provided on the inner periphery of the first group tightening ring 114. The first-group tightening ring 114 is screwed into the first-group barrel 113 with a screw, whereby the inner peripheral inclined surface 114a gradually presses the inclined portion 113c of the first-group barrel 113, and the locking portion 113b of the first lens 111 Press the front curvature surface. The first-group tightening ring 114 is screwed by a screw and thus rotates by assembling, but does not directly contact the first lens 111, so that the first-group lens 111 is fixed without giving friction in the rotational direction to the first-group lens 111. It is possible.

  FIG. 4 shows a state in which the first lens 111 after the second lens 112 and the washer 115 are inserted is being inserted into the first lens barrel 113, and shows a cross section at the position of the locking portion 113b.

  In FIG. 4, (4A) shows a state before the first lens 111 is inserted into the first lens barrel 113, and the locking portion 113b of the first lens barrel 113 is the outer diameter fitting portion 111a of the first lens 111. The smaller diameter state is the initial state.

  Next, (4B) shows a state in which the first lens 111 is being inserted into the first lens barrel 111. The outer diameter fitting portion 111a of the first lens 111 has a locking portion 113b which is elastically integrally connected. It is inserted while pushing up.

  Further, (4C) shows a state in which the first lens 111 is in contact with the first lens barrel via the washer 115 and the second lens 112, and the locking portion 113b is an outer diameter fitting portion of the first lens 111. The position returns so as to get over the position 111a and maintain the curvature surface of the first lens 111. In this state, since the locking portion 113b of the first lens barrel does not sufficiently fix the first lens 111, it is possible to rotate around the optical axis with respect to the first lens barrel.

  Here, the outer diameter fitting portion 111a of the first lens 111 is held by the fitting holding portion 113a of the first lens barrel 113. After the first lens 111 is inserted, the most optically eccentric with respect to other optical elements. Adjust the rotational position to reduce the effect. Means for confirming the influence of optical eccentricity include a method of optically evaluating a transmitted point image, but this is not specified here.

  After the rotation of the first lens group 111 is adjusted, the first group tightening ring 114 is screwed into the first lens barrel 113 as described above, and the first lens 111 and the second lens 112 are sufficiently fixed. As described above, the first-group tightening ring 114 does not directly contact the first lens 111, so that the first-group lens 111 can be fixed while maintaining the rotation adjustment value without applying friction to the first-group lens 111 in the rotational direction. .

  FIG. 5 is a perspective view of a state before the first group tightening ring 114 is attached from the first group unit 110, and (6A), (6B), and (6C) show cross-sectional positions at respective angular phases.

  FIG. 6 is a partial cross-sectional view corresponding to the cross-sectional positions (6A), (6B), and (6C) of FIG. 5, and shows a cross-sectional view in a state where the first-group press ring 114 is attached to the first-group barrel 113. Has become. (6B) shows a locking section 113b including an inclined section 113d, and (6A) shows a cross section of a part of an elastic section 113c having the locking section 113b and the inclined section 113d at both ends. (6C) is a cross section of the fitting holding portion 113a holding the outer diameter fitting portion 111a of the first lens 111.

  Next, the operation of each component will be described.

  FIG. 2 is a cross-sectional view of a lens barrel embodying the present invention in a WIDE state. By operating the zoom ring 5 and rotating the cam ring 7 via the zoom key 8, each of the second to fifth moving groups 15 moves from the imaging side to the object side. The first moving group 11 performs a so-called U-turn operation in which the first moving group 11 moves in the image-side direction and then moves in the object-side direction.

  At this time, as the sub-aperture A unit 12a held by the second movable group 12 moves from the zoom WIDE state to the TELE state, the state in which the diaphragm blades are closed to some extent is changed to the open state. That is, the WIDE side functions to block unnecessary off-axis light and cut off flare.

  Further, as with the sub-aperture A unit 12a, the sub-aperture B unit 14b held by the fourth movable group 14 also changes from the zoom WIDE state to the TELE state, in which the aperture blades are changed from a partially closed state to an open state. This function determines the open aperture at each focal length position of the zoom operation.

  The focus adjustment operation is as described above, but the focus key 9b is engaged with the connection key A19 and rotated via the connection key B20 by manual operation by operating the focus ring 10 in addition to electric drive by electric control. The force is transmitted to the focus cam ring 12b. The rotation of the focus cam ring 12b causes the second group unit 12d, which is integrally held by the second group moving ring 12c, to move back and forth to perform focus adjustment.

  As described above, according to the configuration of the present invention, the first lens 111, which is a double-sided aspheric lens manufactured by molding with respect to another optical element, is adjusted to an optimal position and the first group press ring 114 is tightened. This makes it possible to hold the adjustment position without bonding.

  In the present embodiment, the first lens 111 and the second lens 112 are held by the first lens barrel 113 via the washer 115. However, the first lens 111 directly contacts the first lens barrel 113. The effect is the same in the form of holding. Further, a plurality of lens groups may be provided.

  Further, in this embodiment, the first lens 111 is a double-sided aspherical lens manufactured by molding, but this is a single-sided aspherical lens, and further a normal spherical lens which is not a double-sided, single-sided aspherical lens. It is also possible to obtain the effect of using the present invention.

  Furthermore, even if it is a normal lens whose optical surface is manufactured by a polishing process that is not a lens manufactured by molding and whose outer diameter fitting part is centered by a cutting process, even if it is slightly, it will be out of alignment with the optical axis of the optical surface. As long as the axial displacement of the diameter fitting portion exists, the effect of the present invention can be obtained.

  In the present embodiment, the elastic portion of the first lens barrel is formed integrally with the elastic portion on the premise that the first lens barrel is formed of resin. However, this may be configured as a separate part. It is sufficient that the elastic portion is deformed by the attachment of the press ring, and the rotational position of the lens can be held by tightening.

  FIG. 7 is a partially enlarged sectional view of a first group unit according to a second embodiment of the present invention.

  The first-group barrel 123 has the same configuration as that of the first embodiment, except that the locking portion 123b of the first-group barrel 123 and the wall 124a of the first-group tightening ring 124 are in contact with each other.

  The locking portion 123b in contact with the curvature surface of the first lens 111 is further screwed into the first group tightening ring 124, so that the wall portion 124a directly presses the outer shape of the locking portion 113b, and both The group lens is fixed by being urged in the optical axis direction. Although the first group tightening ring 114 is screwed while rotating, the rotational position is not transmitted to the first lens 111 whose rotation has been adjusted in the same manner as in the first embodiment, so that the adjustment position does not move.

  Further, in this embodiment, the first-group press ring is screwed to the first-group lens barrel with a screw. However, this can be performed by a bayonet connection, or by fixing with a screw from the optical axis direction or the outer peripheral direction. Good. The object of the present invention has been attained if the elastic portion of the first lens barrel is gradually deformed at the stage of inserting the first lens group holding ring so that the lens can be tightened.

1 mount, 2 mount ring, 3 fixed cylinder, 4 control board,
4a contact block, 5 zoom ring, 6,26 guide tube,
6a bayonet groove, 7,27 cam ring, 8 zoom key,
9,29 exterior unit, 9a focus unit, 9b focus key,
9c front unit, 10 focus ring, 11 first moving group,
11b 1st group moving ring, legs 11c, 12 2nd moving group,
12a sub-aperture A unit, 12b focus cam ring,
12c second group moving ring, 12d second group unit, 13 third moving group,
14 fourth moving group, 14a electromagnetic diaphragm unit,
14b flexible printed wiring board, 14c sub-aperture B unit,
15 fifth moving group, 16, 36 deformation receiving member, 16a bayonet claw,
16b through hole, 17 cushioning member, 18, 38 relay ring,
19 connection key A, 20 connection key B, 21 fixing screw, 22, 42 gap A,
23, 43 gap B, 110, 120 1 group unit, 111 first lens,
111a outer diameter fitting portion, 112 second lens, 113, 123 first lens barrel,
113a fitting holding part, 113b, 123b locking part, 113c elastic part,
113d inclined portion, 114 1st group holding ring, 114a inclined surface, 114b wall portion 115 washer

Claims (7)

  A lens barrel having at least one lens that is an optical element, wherein the lens barrel is a lens that is an optical element, a holding barrel that holds the lens, and a fastening that is attached to the holding barrel. A ring is formed, the holding barrel is a fitting portion for holding an outer shape of a lens, a contact portion with which an optical element including the lens is in contact with the optical axis direction, and a lens opposite to the contact portion. Has an engaging portion that abuts on the curvature surface, and the engaging portion is divided into a plurality by changing an angular phase around the optical axis while being connected by an elastic portion having a degree of freedom in an optical axis direction and a radial direction. A lens barrel characterized by being   When the tightening ring is screwed into the holding barrel, the inner peripheral portion of the tightening ring presses the outer portion of the locking portion elastically connected to the holding barrel, and is elastically deformed in the inner circumferential direction. The lens barrel according to claim 1, wherein the locking portion presses the curvature surface of the lens to urge the lens surface in the optical axis direction.   The said tightening ring has an inclined surface in an inner periphery, and urges | biases the said lens from an outer peripheral direction to an optical axis direction by pressing the outer peripheral part of the holding lens barrel. Lens barrel.   4. The tightening ring according to claim 1, wherein the tightening ring has a wall portion that directly presses a locking portion connected by an elastic portion in an optical axis direction while being screwed into the holding barrel. The lens barrel according to claim 1.   The lens barrel according to any one of claims 1, 2, and 4, wherein the holding barrel and the tightening ring are coupled by screwing.   The lens barrel according to any one of claims 1, 2, 3, 4, and 5, wherein the lens is an aspheric lens.   The lens barrel according to any one of claims 1, 2, 3, 4, 5, and 6, wherein the lens is an aspherical lens on both surfaces.