JP2020008707A - Lens barrel - Google Patents

Abstract

To achieve a lens for adjusting a rotational position with respect to a holding lens barrel capable of fixing an adjustment position at an arbitrary position without a step in no step-wise manner without providing a different shape such as a locking section without performing adhesion in order to solve a problem in dismantling while the adjustment position used to be fixed by adhesion after adjusting the rotational angle position of the lens relative to the holding barrel.SOLUTION: By screwing one group depressing ring into one group barrel by a screw, the one group depressing ring gradually depresses an inclined portion of the one group barrel, and a tightening portion tightens and fixes an outer diameter fitting portion of a first lens.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. In Patent Document 2, the rotational position is adjusted by providing a convex or concave engaging portion for regulating the rotation with respect to the lens barrel on a part of the molded lens, and the adjusted lens is adjusted to the pressing ring. It is designed to prevent entrainment from tightening.

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

  However, in the method of fixing the position after lens adjustment with an adhesive as disclosed in Patent Literature 1, when it is necessary to disassemble thereafter, the disassembly itself is not easy, and it is difficult to reuse parts. .

  In Patent Literature 2, it is necessary to provide an irregular shape of a convex or concave portion serving as an engaging portion in a part of the molded lens, and there is a concern about optical effects due to internal distortion and the like during molding due to the irregular shape. You. 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, the present invention according to claim 1 includes a lens that is at least one or more optical elements, a holding barrel that holds the lens, and an optical axis rotation of the lens with respect to the holding barrel. After adjustment, a part of the holding lens barrel that holds the lens by attaching the presser ring is elastically deformed and has a tightening part that tightens the lens from the outer circumference, and the rotation angle phase position of the lens is fixed. With the lens barrel described above, the rotation adjustment position can be held without bonding.

  Further, according to the present invention, the inclined portion provided on the inner periphery of the holding ring presses the inclined portion provided on the outer periphery of the tightening portion of the holding lens barrel, so that the inner lens is formed from the outer peripheral direction. The lens barrel according to claim 1, wherein the lens barrel has an elastically deformable portion that can be tightened, so that the elastically deformable portion presses the internal lens by tightening the holding ring so as to maintain the rotational phase position. It was made.

  According to a third aspect of the present invention, in the lens barrel according to the first or second aspect, the holding barrel and the holding ring are coupled by screwing with a screw. By screwing the holding ring, the elastically deforming portion presses the internal lens to maintain the rotational phase position.

  According to a fourth aspect of the present invention, the molded lens is an aspherical lens, and the lens barrel according to the first, second, or third aspect has an aspherical surface which is largely affected by an optical axis shift. Even when a lens is used, the rotation phase position can be held after adjustment.

  According to a fifth aspect of the present invention, there is provided a lens barrel according to the first, second, third, or fourth aspect, wherein the molded lens is an aspherical lens on both sides. Even if a double-sided aspherical lens having a large influence is used, the holding after the rotation phase position adjustment can be performed.

  Further, in the present invention according to claim 6, the lens is manufactured by molding, and the lens barrel according to claims 1, 2, 3, 4, and 5 is also provided, so that the optical axis shift is also achieved. Thus, even after using a lens manufactured by die manufacturing, which is greatly affected by the above, the holding after the rotation phase position adjustment can be performed.

  According to the present invention, after adjusting the optical axis rotation phase position of the lens with respect to the holding lens barrel, the adjusted position can be fixed without relying on adhesion or the like, and there is an effect that disassembly is easy.

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. 1 is a perspective view of a first unit embodying the present invention. Partial sectional view at each sectional phase position indicated in FIG. FIG. 5A is a partial cross-sectional view showing a state during assembly. Perspective view of a first lens barrel showing another embodiment. Partial 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 perspective view of a lens unit embodying the present invention. FIG. 5 is a partial cross-sectional view at each cross-sectional phase position shown in FIG. 4, and FIG. 6 is a partial cross-sectional view of FIG.

  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, reference numeral 6 denotes a guide cylinder which is connected to the fixed cylinder 3 and has a guide groove for guiding the movable group in a straight line. 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, and FIG. 4 is a perspective view of the first-group unit. The first-group lens barrel 113 is an optical element in which both optical surfaces are molded into an aspheric surface by a mold. One lens 111 and the second lens 112 are held by a first group press ring 114. The first-group barrel 113 and the first-group press ring 114 are coupled by screwing. A washer 115 for adjusting the distance between the lenses is inserted between the first lens 111 and the second lens 112.
FIG. 4 is a perspective view of a state before the first group press ring 114 is attached from the first group unit 110, and (A), (B), and (C) show cross-sectional lines at respective angular phases.

  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 both ends of the elastically deformable elastic portion 113c in the circumferential direction. The tightening portions 113b arranged at the front end extending in the same direction are alternately and equally arranged at three places.

  Although 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, the influence of the most optical eccentricity on other optical elements after the first lens 111 is inserted. Adjust the rotational position to reduce the number. Means for confirming the influence of optical eccentricity include means for optically evaluating a transmitted point image, but this is not specified here.

  Further, an inclined portion 113d is provided on the outer diameter side of the elastic portion 113c of the first lens barrel 113, and an inclined portion 114a is similarly provided on the inner periphery of the first group presser ring 114.

  The first group holding ring 114 is screwed into the first group lens barrel 113 with a screw, whereby the inner peripheral inclined part 114a gradually presses the inclined part 113c of the first group lens barrel 113, and the tightening part 113b is moved outside the first lens 111. The diameter fitting part 111a is tightened. The first group press ring 114 presses the first lens 111 from the front, but since the tightening portion 113b fixes the rotation angle phase position, the first lens 111 can be fixed without changing the rotation adjustment position. is there.

  If the surface of the first lens 111 that comes into contact with the first group press ring 114 is subjected to a low friction treatment such as fluorine coating, the first lens press ring 114 is prevented from screwing around the first lens due to screwing. Stable fixing is possible. The same effect can be expected if a PTFE sheet is interposed or a lubricant is applied instead of the low friction treatment.

  FIG. 5 is a partial sectional view corresponding to the angular positions of the sectional lines (A), (B), and (C) of FIG. 4, in a state where the first group press ring 114 is attached to the first group barrel 113. It is a sectional view. (A) is an elastic portion 113c including an inclined portion 113d, (B) is a fastening portion 113b of the first lens barrel 113 holding the outer diameter fitting portion 111a of the first lens 111, and (C) is a first portion. 3 shows respective cross sections of a fitting holding portion 113a fitted to the outer diameter fitting portion 111a of the lens 111.

  Further, FIG. 6 shows a partial cross-sectional view during the assembling up to the state of FIG. FIG. 6A1 shows a state in which the first-group press ring 114 is screwed into the first-group lens barrel 113 into which the first lens 111 is inserted. In this state, the inclined portion 113d of the first-group lens barrel 113 is still in contact. The inclined portion 114a of the first group holding ring 114 is not in contact. Further, the first lens 111 and the lens holding portion 114b of the first group holding ring 114 are not in contact with each other. Therefore, in this state, the first lens 111 can rotate around the optical axis with respect to the first lens barrel.

  Next, FIG. 6A2 shows a state in which the first group lens barrel 113 and the first lens group holding ring 114 are further screwed together. The inclined part 114a of the first lens group holding ring 114 is different from the inclined part 113d of the first lens group barrel 113. After contact, the elastic portion 113c of the first lens barrel 113 is deformed inward. For this reason, the tightening portions 113b disposed at the circumferentially extending distal ends on both sides of the elastic portion 113c gradually tighten the outer diameter fitting portion 111a of the first lens 111. In this state, the first lens 111 and the lens holding portion 114b of the first group holding ring 114 have not yet come into contact with each other, but the first lens 111 has already been attached to the first group barrel 113 so as to be difficult to rotate around the optical axis. The power is rising.

  When the first group lens barrel 113 and the first group holding ring 114 are further screwed together, the state shown in FIG. 5A is finally obtained, and the first lens 111 is in contact with the lens holding portion 114b of the first group holding ring 114. . Since the outer diameter fitting portion 111a of the first lens 111 is tightened by the tightening portion 113b, the lens pressing portion 114b of the first group press ring 114 abuts on the first lens 111, and even if friction occurs here, the first lens pressing portion 114b is in the first position. The lens 111 is fixed while maintaining the rotational phase position.

  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 is a double-sided aspherical lens manufactured by molding, but this is a single-sided aspherical lens, and is 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.

  In addition, even if it is a normal lens whose optical surface is manufactured by a polishing process that is not a lens manufactured by die molding and whose outer diameter fitting portion 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. 6 is a perspective view of a first lens barrel according to a second embodiment of the present invention, and FIG. 7 is a partial sectional view of a portion corresponding to the section (A) of FIG.

  The first-group lens barrel 123 has the same configuration as that of the first embodiment, except that the inclined portion 113d in the first embodiment is a hemispherical projection 123d.

  When the first group holding ring 114 is screwed into the first group barrel 123 with a screw, the inclined portion 114a of the first group holding ring 114 gradually presses the projection 123d of the first group barrel 123, and the elastic portion 123c. The fastening portion 123b holds the first lens 111 while deforming.

  Further, in the present embodiment, the inclined portion 114b of the first-group press ring 114 presses the inclined portion 113d of the first-group barrel 113, but the elastic portion of the first-group barrel is deformed by attaching the first-group press ring. The type is not limited as long as the tightening portion can tighten the lens.

  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 cylinder, 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 1 group moving ring, 11c leg, 12 second moving group,
12a sub-aperture A unit, 12b focus cam ring, 12c two-group moving ring,
12d 2nd group unit, 13 3rd moving group, 14 4th moving group,
14a electromagnetic aperture 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 connecting key A, 20 connecting 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 1st lens barrel, 113a, 123a
113b, 123b fastening part, 113c, 123c elastic part,
113d inclined portion, 123a protrusion, 114 1 group press ring, 114a inclined portion,
114b lens holder, 115 washer

Claims (6)

At least one or more optical elements, a lens, a holding barrel that holds the lens, and a part of the holding barrel that holds the lens by attaching a pressing ring are elastically deformed to tighten the lens from the outer periphery. A lens barrel having a tightening portion and fixing a rotational angle phase position of a lens. An inclined portion provided on the inner periphery of the holding ring has an elastically deformable portion capable of clamping an inner lens from an outer peripheral direction by pressing an outer diameter portion of a clamping portion of the holding barrel. The lens barrel according to claim 1, wherein The lens barrel according to claim 1, wherein the holding barrel and the holding ring are coupled by screwing with a screw. The lens barrel according to claim 1, wherein the lens is an aspherical lens. The lens barrel according to claim 1, wherein the lens is an aspheric lens on both surfaces. The lens barrel according to claim 1, wherein the lens is manufactured by molding.