JP2014228730A - Lens barrel and optical device using the same - Google Patents

Abstract

A lens barrel that can easily and accurately adjust the optical axis of a lens, and that can stably maintain the position of the lens even when an impact or the like is applied, and has good disassembly, and a lens barrel using the same Provide optical equipment. In a lens barrel, a holding cylinder that holds a lens, a contact ring that contacts the lens, a press ring that is screwed to the holding cylinder and presses the lens across the contact ring; A rotating sliding portion that causes sliding between the pressing ring and the contact ring. [Selection] Figure 1

Description

  The present invention relates to a lens barrel having a structure for adjusting the optical axis of a lens and an optical apparatus using the same.

  Conventionally, when holding a lens as an optical element in a lens barrel, adjustment (coaxial adjustment) was performed to align the optical axis with other lenses in order to ensure optical performance. It was difficult to do. On the other hand, in patent document 1, the taper surface provided in the lens as an optical element is hold | maintained with the taper surface of the receiving surface of a lens-barrel, or the taper surface of a holding ring, and the optical element with respect to a lens-barrel Coaxial adjustment and alignment are performed.

  Further, in Patent Document 2, the lens contact surface of the presser ring is lubricated to reduce friction so that the lens can easily slide with respect to the presser ring, and the position of the lens is automatically adjusted by tightening the presser ring. Try to keep it in the center. In addition, a plurality of screws penetrating from several directions on the outer peripheral side of the lens barrel are extended or retracted, and the lens that is in contact with the screw is moved slightly to adjust the coaxial position, or the lens is adjusted using an adjustment tool. There was a method of fixing the position by adhesion after the position adjustment.

JP 2010-134378 A JP 02-146008 A

  However, in the configuration of Patent Document 1, when the presser ring is screwed in order to maintain the optical axis position of the lens, after the presser ring comes into contact with the lens, rotational friction is applied between the presser ring and the lens, and the lens center. May prevent the lens from moving to the center position of the lens barrel. If the screwing of the presser ring stops due to friction in such a state, there is a problem that the optical axis of the lens cannot be adjusted.

  Even in the configuration of Patent Document 2, even if the contact surface between the lens and the presser ring is lubricated, a certain amount of friction still remains. Therefore, when the lens is finally tightened, the lens is adjusted to an accurate coaxial position. There are cases where the optical axis of the lens cannot be adjusted because the lens is fixed without being able to be centered.

  In addition, in the method of adjusting the position of the lens with a plurality of screws from the outer peripheral direction of the lens barrel, the adjustment work is complicated, or a means for confirming the target position to be adjusted is required, so that there is a problem that the tool cost is increased. . Furthermore, since stress is applied to the lens from the outer periphery by screw urging, the lens surface may be distorted, or the lens may be destroyed due to stress concentration due to screw contact when a drop impact is applied in this state. was there.

  In addition, the method of fixing the position by bonding after adjusting the position of the lens using an adjustment tool still requires a tool cost for adjusting the position, and if it needs to be disassembled for correction, it is fixed. It is necessary to remove the adhesive material, and the work is difficult.

  An object of the present invention is to make it possible to easily and accurately adjust the optical axis of a lens, and to maintain a lens position stably even when an impact or the like is applied. The object is to provide an optical apparatus using the same.

  In order to achieve the above object, a lens barrel according to the present invention includes a holding cylinder that holds a lens, a contact ring that contacts the lens, and a screw that engages with the holding cylinder, with the contact ring interposed therebetween. A presser ring for pressing the lens, and a rotary sliding portion that causes sliding between the presser ring and the contact ring with respect to the rotation of the presser ring.

  According to the present invention, it is possible to easily and accurately adjust the optical axis of a lens, and furthermore, it is possible to stably maintain the position of the lens even when an impact or the like is applied, and to provide a lens barrel having a good dismantling property. An optical apparatus using this can be provided.

1 is a cross-sectional view of a lens barrel according to a first embodiment of the present invention. 1 is an exploded perspective view of a lens barrel according to a first embodiment of the present invention. It is a partial expanded sectional view of the lens barrel which concerns on the 2nd Embodiment of this invention. It is a partial expanded sectional view of the lens barrel which concerns on the 3rd Embodiment of this invention. It is a disassembled perspective view of the lens barrel which concerns on the 3rd Embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

<< First Embodiment >>
(Optical equipment)
An optical system including a lens held by a lens barrel according to the present invention is, for example, a photographing optical system or a projection optical system. It is suitable for an optical device such as a projector using a projection optical system.

(Lens barrel)
1 and 2, G1, G2, and G3 are lenses as optical elements, respectively, and G2 and G3 are bonded together to integrate the lenses. Reference numeral 4 denotes a lens barrel as a holding cylinder for holding each lens, and reference numeral 6 denotes a first contact ring that contacts the lens G1. Reference numeral 5 denotes a first presser ring that holds the first contact ring 6, and the first presser ring 5 is screwed into the lens barrel 4 with a screw 5 b. Further, the first contact ring 6 rotates when the rotation restricting projection 6 b is engaged with the first contact ring rotation restricting groove 4 a provided in the lens barrel 4. This is restrained (regulated).

  Here, as a rotary sliding portion that causes rotational sliding, the first contact ring 6 is provided with a first conical surface 6a, and the first presser ring 5 is provided with a second conical surface 5a. . Then, the conical surface 6a of the first contact ring 6 and the conical surface 5a of the first presser ring 5 come into contact with each other, so that the respective centers of the first presser ring 5 and the first contact ring 6 are in contact. The axis position will be matched.

  Reference numeral 8 denotes a second contact ring that contacts the optical element G2, 7 denotes a second presser ring that holds the second contact ring, and the second presser ring 7 is attached to the lens barrel 4 with a screw 7b. Are screwed together. Further, the second contact ring 8 is rotated by the rotation restricting projection 8 b engaging with the second contact ring rotation restricting groove 4 b provided in the lens barrel 4. It is restrained (regulated).

  Here, as a rotational sliding portion that causes rotational sliding, the second contact ring 8 is provided with a conical surface 8 a and the second presser ring 7 is provided with a conical surface 7 a. Then, the conical surface 8a of the second contact ring 8 and the conical surface 7a of the second presser ring 7 come into contact with each other, so that the respective centers of the second presser ring 7 and the second contact ring 8 The axis position will be matched.

  In addition, annular sheet materials 10 and 11 are disposed between the optical element barrel-attached portion of the lens barrel 4 and the optical elements G1 and G3.

  Here, as shown in FIG. 2, the cone of the first contact ring 6 and the first presser ring 5 is larger than the tangential angle α2 at the position where the first contact ring 6 and the optical element G1 are in contact. The tangent angle α1 of the surface is an acute angle. That is, α1 <α2, and the accuracy with which the first presser ring 5 aligns the first contact ring 6 is higher than the accuracy with which the first contact ring 6 aligns the optical element G1. ing.

  The above description is only for the lens G1, but the same applies to the lenses G2 and G3, and the second contact ring 8 and the second contact ring 8 are more than the tangential angle formed by the second contact ring 8 that contacts the lens G2. The tangential angle formed by the second presser ring 7 is an acute angle.

(Assembly procedure)
Next, the assembly procedure will be described with reference to FIGS. First, the G3 sheet 11 and the lenses G2 and G3 bonded to each other are inserted into the lens barrel 4. Next, the second contact ring is moved to a position where it comes into contact with the lens G2 while aligning the rotation restricting projection 8b with the two contact ring rotation restricting portions 4b provided in the circumferential direction of the lens barrel 4. 8 is inserted. Further, the second presser ring 7 is screwed into the lens barrel 4 until the conical surface 7 a of the second presser ring 7 contacts the conical surface 8 a of the second contact ring 8.

  At this time, the rotation restricting protrusion 8b is engaged with the contact ring rotation restricting groove 4b of the lens barrel 4 so that the second abutment ring 8 is brought into contact with the lens G2 in a state where it cannot rotate. ing. Then, while the second presser ring 7 screwed by the screw 7b is rotated and fed, the conical surfaces 7a and 8a of the second presser ring 7 and the second contact ring 8 come into contact with each other, and the second presser ring 7 Rotational sliding occurs between the conical surfaces of the presser ring 7 and the second contact ring 8. On the other hand, since the rotation of the second contact ring 8 is restricted by the rotation restricting projection 8b as the rotation restricting member and the contact ring rotation restricting groove 4b, the second contact ring 8 is not between the second contact ring 8 and the lens G2. Rotational sliding does not occur.

  As the conical surfaces 7a and 8a come into contact with each other, the rotation axes of the second presser ring 7 and the second contact ring 8 coincide with each other. Further, between the second contact ring 8 and the lenses G2 and G3, the inclined surfaces contact each other, so that the optical axes of the lenses G2 and G3 and the rotation axis (center axis) of the second contact ring 8 are obtained. Will match. When the rotation of the second presser ring 7 stops, the rotation axis (center axis) of the lens barrel 4 and the rotation axis (center axis) of the second presser ring 7 due to the alignment of the screws. Are matched, the lenses G2, G3, the second contact ring 8, and the second presser ring 7 are fixed.

  Further, the G1 sheet 10 and the lens G1 are inserted into the lens barrel 4. The first abutment ring 6 is inserted to the position where it abuts on the lens G1, while aligning the rotation restricting projection 6b with the two abutment ring rotation restricting portions 4b provided on the lens barrel 4. Further, the first presser ring 5 is screwed into the lens barrel 4 until the conical surface 5 a of the first presser ring 5 contacts the conical surface 6 a of the first contact ring 6.

  At this time, the rotation restricting projection 6b is engaged with the contact ring rotation restricting groove 4b of the lens barrel 4, and the first contact ring 6 is brought into contact with the lens G1 in a state where it cannot rotate. ing. Then, while the first presser ring 5 screwed with the screw 5b is rotated and fed out, the conical surfaces 5a and 6a of the first presser ring 5 and the first contact ring 6 come into contact with each other, and the first presser ring 5 Rotational sliding occurs between the presser ring 5 and the conical surface of the first contact ring 6. On the other hand, since the rotation of the first contact ring 6 is restricted by the rotation restricting projection 6b as the rotation restricting member and the contact ring rotation restricting groove 4b, the first contact ring 6 is not between the first contact ring 6 and the lens G1. Rotational sliding does not occur.

  As the conical surfaces 5a and 6a come into contact with each other, the rotation axes of the first presser ring 5 and the first contact ring 6 coincide with each other. Further, between the first contact ring 6 and the lens G1, the inclined surfaces are in contact with each other, so that the optical axis of the lens G1 and the rotation axis (center axis) of the first contact ring 6 coincide. Go. When the rotation of the first presser ring 5 stops, the rotation axis (center axis) of the lens barrel 4 and the rotation axis (center axis) of the first presser ring 5 due to the alignment of the screws. And the lens G1, the first contact ring 6, and the first presser ring 5 are fixed.

  As described above, the first presser ring 5 and the second presser ring 7 are screw-centered with respect to the lens barrel 4, so that the first presser ring 6 and the second presser ring 8 are respectively interposed. Thus, the optical elements G1, G2, and G3 are accurately aligned with the center of the rotation axis (center axis) of the lens barrel 4.

<< Second Embodiment >>
In the first embodiment, the rotation of the lens barrel 4 is restricted by the first contact ring 6 and the second contact ring 8 so as not to cause rotational sliding between the lens and the contact ring. The configuration in which the rotation restricting protrusions 6b and 8b are provided and engaged with the contact ring rotation restricting groove 4b of the lens barrel 4 is used. In this embodiment, instead of using a rotation restricting member such as the contact ring rotation restricting groove 4b and the rotation restricting protrusions 6b and 8b, the difference between the sliding frictional force in the rotation and sliding is provided, so that the lens and the contact ring are separated. This method uses a method of suppressing rotational sliding.

  That is, the sliding frictional force in the rotational sliding generated between the pressing member and the contact member is set smaller than the sliding frictional force in the rotational sliding generated between the lens and the contact member. Thereby, in this embodiment, the contact ring rotation restricting groove 4b and the rotation restricting protrusions 6b and 8b can be eliminated. The other points are the same as those in the first embodiment, and a description of the same items as those in the first embodiment is omitted.

  3 which shows this embodiment, the same code | symbol as FIG. 1 shows the same member. In FIG. 3, the tangent angle α1 (acute angle) at which the conical surface 6a of the contact ring 6 and the conical surface 5a of the presser ring 5 are in contact is set smaller than the tangential angle α2 (acute angle) at which the lens G1 and the contact ring 6 are in contact. Yes. Thereby, the precision of the alignment property by the screw 5b can be improved. Note that the above description relates to the lens G1, but the same applies to the other lenses G2 and G3.

<< Third Embodiment >>
Next, a third embodiment of the present invention will be described with reference to FIGS. In this embodiment, instead of the rotating sliding portion using the conical surfaces 5a and 6a in the first embodiment, a rotating sliding portion provided with a planetary rotating member between the pressing member and the abutting member is used. is there. In this embodiment, the contact ring rotation restricting groove 4b and the rotation restricting protrusions 6b and 8b in the first embodiment can be eliminated. The other points are the same as those in the first embodiment, and a description of the same items as those in the first embodiment is omitted.

  Hereinafter, only the alignment of the lens G1 and the lens barrel 4 will be described, but the present invention can be applied to other lenses, and the alignment of necessary lenses in the lens barrel 4 can be performed. First, the G1 sheet and the optical element G1 are inserted into the lens barrel 4. Further, the first abutment ring 23 is inserted to a position where it abuts on the lens G 1, and the ball retainer 22 is arranged on the first abutment ring 23. The ball retainer 22 is provided with a plurality of ball holding holes 22a in the circumferential direction (for example, approximately three at equal angles), and the rolling balls 21 are arranged in the ball holding holes 22, respectively. A plurality of rolling balls 22 are integrally held at the center of the optical axis in the circumferential direction on a V-groove 23a which is a groove provided in the first contact ring 23.

  Next, the first presser ring 20 is screwed into the lens barrel 4, and the V-shaped groove 20 a provided in the first presser ring 20 is arranged in a V-groove shape of the first contact ring 23. The moving ball 21 is retracted until it comes into contact. The first presser ring 20 and the first contact ring 23 are configured in a state in which rolling balls are sandwiched between the V grooves 20a and 23a.

  Compared to the sliding friction force between the first contact ring 23 and the lens G1, the sliding friction force in the rotational sliding between the first contact ring 23 and the first presser ring 20 is overwhelming. small. For this reason, even if the first presser ring 20 is retracted while being rotated, there is no rotational sliding between the lens G1 and the first contact ring 23. In addition, since the rolling ball 21 is received by the V groove 20a of the first presser ring 20 and the V groove 23a of the first contact ring 23, the first presser ring 20 and the first contact ring 23 have an accuracy. The center axis of rotation agrees well.

  As described above, when the first presser ring 20 is screw-centered with respect to the lens barrel 4, the lens G <b> 1 is accurately centered around the rotation axis via the first contact ring 23.

(Modification)
As mentioned above, although embodiment of this invention was described, this invention is not limited to this, A various deformation | transformation is possible within the range of identity.

(Modification 1)
In the second embodiment described above, the conical surface 6a of the contact ring 6 and the conical surface 5a of the presser ring 5 are used without using the contact ring rotation restricting groove 4b and the rotation restricting projections 6b and 8b in the first embodiment. Reduced the tangent angle that touches. However, the method of suppressing the rotational sliding between the lens G1 and the contact ring 6 is not limited to this. When the conical surface 5a of the first presser ring 5 and the conical surface 6a of the first contact ring 6 slide, the sliding surfaces 5a and 6a are lubricated or a lubricant is applied. A method may be used.

(Modification 2)
In the third embodiment described above, the planetary rotating member between the presser ring and the abutment ring is a rolling ball. However, the planetary rotary member maintains the receiving shape of the presser ring and the abutment ring at the center of the optical axis. It can be made into a shape that can be a roller or gear, and the effect remains the same. Further, in the third embodiment, the rolling balls are held at the angular phase at equal intervals by the ball retainer, but an all-round ball race may be used without using the ball retainer.

(Modification 3)
In addition, it is also possible to combine suitably embodiment mentioned above and a modification within the scope of the present invention.

4 .. Lens barrel, 5.

Claims (12)

A holding cylinder for holding the lens;
A contact ring that contacts the lens;
A presser ring that is screwed into the holding cylinder and holds the lens across the contact ring;
A rotating sliding portion that causes sliding between the press ring and the contact ring;
A lens barrel comprising:   The lens barrel according to claim 1, further comprising a rotation restricting member that restricts rotation between the contact ring and the lens.   2. The lens barrel according to claim 1, wherein a sliding frictional force in the rotary sliding portion is set smaller than a sliding frictional force in the rotational sliding between the contact ring and the lens.   The contact ring is provided with a first conical surface, and the presser ring is provided with a second conical surface, and the rotating sliding portion is configured by contact between the first conical surface and the second conical surface. The lens barrel according to any one of claims 1 to 3, wherein the lens barrel is provided.   4. The lens barrel according to claim 3, wherein an acute angle of a tangential angle at which the presser ring and the contact ring are in contact is set smaller than an acute angle of a tangential angle at which the lens and the contact ring are in contact.   The lens barrel according to claim 3, wherein a lubrication process or a lubricant is applied to a sliding surface between the presser ring and the abutment ring in the rotary sliding portion.   The lens barrel according to claim 3, wherein a planetary rotating member that contacts the presser ring and the contact ring is provided between the presser ring and the contact ring.   The lens barrel according to claim 7, wherein each of the presser ring and the contact ring is provided with a groove portion for holding the planetary rotating member.   9. The lens barrel according to claim 7, wherein a plurality of the planetary rotating members are provided in a circumferential direction around the optical axis of the lens.   The lens barrel according to claim 9, further comprising a retainer that integrally holds the plurality of planetary rotating members.   The lens barrel according to any one of claims 7 to 10, wherein the planetary rotating member is a rolling ball. An optical apparatus comprising a lens and the lens barrel according to any one of claims 1 to 11.