JP4917074B2 - Lens support structure - Google Patents

Description

  The present invention relates to a lens support structure, and more particularly to a lens support structure that removably supports a lens holding frame on an outer frame without using an adhesive.

In a lens barrel, a lens holding frame that supports a lens is generally fixed to an outer frame (for example, a frame that moves with zooming).
JP 2005-300859 A

  As such a lens support structure, a fixing structure using a squeeze ring (annular screw member) has been used in the past. However, squeeze ring is difficult to adopt for a small lens barrel.

  In recent lens barrels, in order to reduce the size, the lens holding frame is fixed to the outer frame with an adhesive. Although the adhesive structure is advantageous for miniaturization, for example, a defect is found in the lens by optical inspection after assembly, and it is difficult to remove from the outer frame when replacing the lens. The entire outer frame must be replaced, or adhesive powder may remain and cause a subsequent optical failure.

  An object of the present invention is to provide a lens support structure that removably supports a lens holding frame on an outer frame without using an adhesive, based on the above problem awareness.

  The lens support structure of the present invention includes a lens holding frame that holds a lens; an outer frame that supports the lens holding frame; and an annular shape for fixing the lens holding frame in a positioning state in which the lens holding frame is pressed against the optical axis orthogonal reference plane of the outer frame. A plurality of tapered protrusions that are positioned on an arc around the center of the optical axis and are fitted to each other in the above-described positioning state, on one and the other of the lens holding frame and the outer frame. A tapered hole is formed, and the one and the other of the annular spring member and the outer frame are aligned at their specific relative rotational positions so that they can move relatively close to each other in the optical axis direction. A lens holding frame is formed when an insertion notch and a retaining projection are formed so as to prevent the member from being removed, and the annular spring member is rotated relative to the outer frame at the approach position and rotated to the fixed position. The A plurality of spring arms to be pressed against the optical axis orthogonal reference surface of the side frame are provided, and one of the lens holding frame and the annular spring member is opposed to the urging force of the spring arm at a fixed position of the annular spring member, When a rotational force is applied to the lens holding frame with respect to the outer frame to disengage the taper protrusion and the taper hole, the annular spring member is rotated together to align the positions of the insertion notch and the retaining protrusion. It is characterized in that a separation engagement portion is provided.

  Specifically, the detachment engagement portion is constituted by, for example, a detachment protrusion formed on the lens holding frame and a detachment wall provided on the annular spring member to which the detachment protrusion engages at the fixed position of the annular spring member. can do. The spring arm of the annular spring member is practically composed of a cantilever spring portion extending in the circumferential direction. At this time, the separation wall of the annular spring member is adjacent to the free end of the cantilever spring portion. Can be provided.

  In another embodiment, the disengagement engaging portion includes a disengagement groove formed in the lens holding frame and a disengagement protrusion provided on the annular spring member that engages with the disengagement groove at the fixed position of the annular spring member. It can also be configured.

  According to the present invention, the lens holding frame is pressed against the optical axis orthogonal reference surface of the outer frame to fit the tapered protrusion and the tapered hole, and in this state, the annular spring member, the insertion notch portion and the retaining protrusion portion of the outer frame are fitted. When the annular spring member is pressed against the lens holding frame and rotated, the lens holding frame can be fixed to the outer frame by the biasing force of the spring arm. On the other hand, when removing the lens holding frame, the lens holding frame is rotated, and the annular spring member is moved in the direction in which the positions of the insertion notch and the retaining protrusion match with each other by the engaging part of the lens holding frame and the annular spring member. By rotating together, the engagement of the taper projection and the taper hole of the lens holding frame and the outer frame can be released, and the annular spring member can be removed from the outer frame. For this reason, even if it is necessary to change the lens of the lens holding frame after assembly, the outer frame can be reused. Conversely, only the outer frame can be exchanged.

  The lens support structure of this embodiment is composed of three members, a lens holding frame 10, an outer frame 20, and an annular spring member (plate spring member) 30 as clearly shown in FIGS. 1 and 4. The lens holding frame 10 made of a synthetic resin material molding has an annular shape (cylindrical shape) as a whole, and holds (fixes) the lens 12 to the central cylindrical portion 11. The lens 12 may be either glass or synthetic resin, and the fixing means for the central cylindrical portion 11 may be any means such as adhesion or heat caulking. The lens holding frame 10 is integrally formed with a plurality of radially projecting portions 13 (four in the illustrated example at intervals of 90 °, particularly see FIG. 2) located on the outer periphery of the central cylindrical portion 11. One surface of the front and back surfaces of the radial protrusion 13 forms an annular reference surface 14 that is orthogonal to the optical axis. A plurality of tapered tapered protrusions 15 are formed on the optical axis orthogonal reference plane 14 so as to be positioned on the same circumference and project in a direction parallel to the optical axis.

  The outer frame 20 made of a synthetic resin material has a ring shape (cylindrical shape) larger in diameter than the lens holding frame 10 as a whole. The outer frame 20 is, for example, a zoom lens barrel zooming frame (a frame that supports a lens group that changes its focal length by moving back and forth in the optical axis direction) as a position of the entire lens barrel. As shown in FIGS. 1 and 4, the outer frame 20 is formed with an annular optical axis orthogonal reference surface 21 with which the optical axis orthogonal reference surface 14 of the lens holding frame 10 abuts. Four tapered holes 22 corresponding to the four tapered tapered protrusions 15 of the lens holding frame 10 are formed on the reference surface 21.

  The lens holding frame 10 and the outer frame 20 are positioned in the radial direction at the fitting portion between them, and are positioned in the thrust direction by the contact engagement between the optical axis orthogonal reference surface 14 and the optical axis orthogonal reference surface 21, and are tapered. Due to the fitting relationship between the tapered protrusion 15 and the tapered hole 22, positioning in the rotational direction is performed.

  The annular spring member 30 supports (fixes) the lens holding frame 10 and the outer frame 20 with the optical axis orthogonal reference surface 14 and the optical axis orthogonal reference surface 21 being in close contact with each other. A plurality of insertion notches 31 are formed on the peripheral edge of the annular spring member 30 formed of a disc-shaped leaf spring as a whole. The insertion cutout 31 may be a hole in addition to the groove shape shown in the figure. On the other hand, four retaining projections 23 are formed on the outer frame 20 so as to correspond to the insertion cutouts 31. The annular spring member 30 can move closer to the optical axis orthogonal reference plane 21 side when the positions of the insertion notch 31 and the retaining projection 23 are matched. After the approaching movement, relative rotation can be performed on the back surface of the retaining projection 23, and when the relative rotation is performed, the front surface of the annular spring member 30 (left side in FIG. 1) and the back surface of the retaining projection portion 23 (on the right side). ) Are engaged, and the retaining is achieved.

  The annular spring member 30 has a plurality of arc grooves 32 and radial grooves (in the illustrated example, four at 90 ° intervals, see FIG. 1 and FIG. 3), which are positioned radially inward of the insertion notch 31. A detachable wall 33 is formed, and the arc groove 32 and the radial groove 33 form a cantilever spring arm 34 extending in the circumferential direction. The cantilever spring arm 34 extending in the circumferential direction is provided with a bend toward the optical axis orthogonal reference plane 21 (lens holding frame 10) as shown at the left end (A) in FIG. A circular arc portion 16 corresponding to the spring arm 34 is formed on the radially projecting portion 13 of the frame 10, and a separation projection 17 projecting toward the spring arm 34 is formed on the tip portion. The separation protrusion 17 can be engaged with a wall surface of the radial groove (detachment wall) 33 (a wall surface opposite to the spring arm 34). A guide protrusion 18 formed on the radial protrusion 13 of the lens holding frame 10 and a guide protrusion 24 formed on the outer frame 20 are fitted into the arc groove 32 of the annular spring member 30, and the guide protrusion 24 is annular with respect to the outer frame 20. The rotation range of the spring member 30 is regulated.

  The tapered taper projection 15 of the lens holding frame 10 and the taper hole 22 of the outer frame 20 are tapered so that the lens holding frame 10 and the outer frame 20 are in close contact with each other when they are fitted together and closely attached by the annular spring member 30. When a relative rotational force is applied, the tapered tapered protrusion 15 is set out from the tapered hole 22 so that the optical axis orthogonal reference surface 14 and the optical axis orthogonal reference surface 21 are separated from each other.

  The lens support structure having the above configuration is used as follows. When the lens holding frame 10 is coupled to the outer frame 20, the tapered taper protrusion 15 of the lens holding frame 10 is fitted into the tapered hole 22 of the outer frame 20. In this state, the position of the retaining projection 23 of the outer frame 20 and the position of the insertion notch 31 of the annular spring member 30 are matched, the annular spring member 30 is pushed in, and the spring arm 34 is brought into contact with the release projection 17 to be elastically deformed. (FIG. 5B). At this time, the guide protrusion 18 of the lens holding frame 10 and the guide protrusion 24 of the outer frame 20 enter the arc groove 32 of the annular spring member 30. When the annular spring member 30 is rotated relative to the lens holding frame 10 in this state, the annular spring member 30 enters the back surface of the retaining projection 23 and is prevented from coming off, and the spring arm 34 is relative to the separation projection 17. Then, the separation protrusion 17 enters the radial groove 33 (FIG. 5C). This state is a stable state, the tapered tapered protrusion 15 of the lens holding frame 10 is fitted into the tapered hole 22 of the outer frame 20, and the optical axis orthogonal reference surface 14 of the lens holding frame 10 is the optical axis orthogonal reference of the outer frame 20. The lens holding frame 10 and the outer frame 20 are fixed in close contact with the surface 21. That is, the annular spring member 30 pushes the lens holding frame 10 in the thrust direction, and the taper protrusion 15 and the tapered hole 22 are engaged by the force, and the rotation of the lens holding frame 10 with respect to the outer frame 20 is suppressed. Then, the rotation of the lens holding frame 10 is suppressed, and thus the rotation of the annular spring member 30 is suppressed. The annular spring member 30 is prevented from rotating by the separation protrusion 17 entering between the tip of the spring arm 34 and the wall portion of the radial groove 33, and the lens holding frame 10 can be easily detached in a normal use environment. Absent. There is no need to use an auxiliary material called an adhesive.

  When it is necessary to remove the lens holding frame 10 from the outer frame 20, the lens holding frame 10 (and the annular spring member 30) is placed in a direction (fixed) in which the position of the insertion notch 31 matches the retaining projection 23 of the outer frame 20. It is rotated in the release direction (arrow X direction in FIG. 5C). In this rotation operation, the rotation auxiliary hole 19 (FIGS. 1 and 3) of the lens holding frame 10 can be used. When the lens holding frame 10 is rotated in the unlocking direction, the detachment protrusion 17 of the lens holding frame 10 is engaged with the radial groove (detachment wall) 33 of the annular spring member 30, so that the annular spring member 30 is joined together. Rotate in the same direction. As described above, the taper of the tapered tapered protrusion 15 and the taper hole 22 opens the taper between the optical axis orthogonal reference surface 14 and the optical axis orthogonal reference surface 21 when the lens holding frame 10 is turned. Since the tapered tapered protrusion 15 is set so as to be detached from the hole 22, the spring arm 34 is pushed by the arc portion 16 and elastically deformed, and the positions of the insertion notch 31 and the retaining protrusion 23 are matched ( FIG. 5 (D) to (E)). When the positions of the insertion notch 31 and the retaining protrusion 23 match, the annular spring member 30 can be removed from the outer frame 20 and the lens holding frame 10 can be removed from the outer frame 20.

  FIG. 6 shows another embodiment of the present invention. In this embodiment, a separation groove 17G is formed instead of the separation protrusion 17 of the lens holding frame 10 of the first embodiment, and a separation protrusion 34P that engages with the separation groove 17G is formed at the tip of the spring arm 34. It is an embodiment.

  The relationship between the tapered protrusion 15 of the lens holding frame 10 and the tapered hole 22 of the outer frame 20 in the above embodiment can be reversed. Similarly, the relationship between the retaining projection 23 of the outer frame 20 and the insertion notch 31 of the annular spring member 30 can be reversed.

It is a perspective view of a disassembled state of a lens holding frame, an outer frame, and an annular spring member, showing an embodiment of a lens support structure according to the present invention. It is the perspective view which looked at the lens holding frame in FIG. 1 from the opposite direction. It is a front view of the assembly state (lens support state) of the lens support structure. It is sectional drawing of the assembly state (lens support state) of the lens support structure. It is a development view in the circumferential direction showing the assembly procedure and disassembly procedure of the lens support structure. FIG. 6 is a development view corresponding to FIG. 5 showing another embodiment of the lens support structure according to the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Lens holding frame 11 Center cylindrical part 12 Lens 13 Radial direction protrusion part 14 Optical axis orthogonal reference surface 15 Tapered taper-shaped protrusion 16 Arc part 17 Separation protrusion 17G Removal groove 18 Outer frame 21 Optical axis orthogonal reference surface 22 Taper Hole 23 Detachment protrusion 24 Guide protrusion 30 Annular spring member 31 Insertion notch 32 Arc groove 33 Radial groove (detachment wall)
34 Spring arm 34P Separation protrusion

Claims (4)

A lens holding frame for holding the lens;
An outer frame that supports the lens holding frame; and an annular spring member for fixing the lens holding frame in a positioning state in which the lens holding frame is pressed against the optical axis orthogonal reference surface of the outer frame;
With
A plurality of tapered protrusions and tapered holes, which are formed on one and the other of the lens holding frame and the outer frame, respectively, positioned on a circular arc at the center of the optical axis and fitted together in the positioning state;
The positions of the annular spring member and the outer frame coincide with each other at a specific relative rotational position so that the annular spring member and the outer frame can move relatively close to each other in the optical axis direction. Insertion notches and retaining protrusions formed in
When the annular spring member is relatively rotated at the approach position with respect to the outer frame and rotated to the fixed position, the lens holding frame is pressed against the optical axis orthogonal reference plane of the outer frame. A spring arm; and at the fixed position of the annular spring member, when the engagement of the taper protrusion and the taper hole is disengaged by applying a rotational force against the outer frame to the lens holding frame against the biasing force of the spring arm, A plurality of disengagement engaging portions provided on one and the other of the lens holding frame and the annular spring member to rotate the annular spring member together so as to match the positions of the insertion notch and the retaining projection;
A lens support structure comprising: 2. The lens support structure according to claim 1, wherein the separation engagement portion is provided on a separation protrusion formed on the lens holding frame and the annular spring member engaged with the separation protrusion at the fixed position of the annular spring member. Lens support structure that is a separation wall. 3. The lens support structure according to claim 2, wherein the spring arm of the annular spring member comprises a cantilever spring portion extending in the circumferential direction, and a separation wall of the annular spring member is adjacent to a free end portion of the cantilever spring portion. A lens support structure provided. 2. The lens support structure according to claim 1, wherein the separation engagement portion is provided on the annular spring member that engages with the separation groove formed in the lens holding frame and the separation groove at the fixed position of the annular spring member. Lens support structure that is a detached protrusion.

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