JP2003337270A - Lens holding frame - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lens holding frame to be injection-molded easy in the mold machining of a lens holding part and good in concentricity and accuracy of parallelism. <P>SOLUTION: Fitting inner peripheral surfaces 9 and 11 on which the outside diameters of a plurality of lenses are fit and annular receiving surfaces 10 and 12 on which the rear end faces of a plurality of lenses abut are provided on the annular inner periphery of the lens holding frame 1. A cut surface parallel with an optical axis O and a cut surface orthogonal to the optical axis O for forming a thin part are provided at trisected positions on the annular outer periphery of the frame 1. A plurality of lenses whose shrinkage amount in terms of the molding is small are supported by the fitting inner peripheral surface and the annular receiving surface at a part corresponding to the thin part projecting with respect to other parts. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the structure of a lens holding frame.

[0002]

2. Description of the Related Art In general, synthetic resin parts produced by molding are subject to sink marks and deformation depending on the position of the gate and the shape of the parts. For parts that require precision, such as the lens holding frame that holds the lens, slight sink marks and deformations are also problems. Therefore, as a proposal for improving the accuracy of the lens fitting portion of the synthetic resin lens holding frame, Japanese Patent Laid-Open No. 61-23
Japanese Patent Application Laid-Open No. 6513 and Japanese Patent Application Laid-Open No. 62-2219 discloses a product having a lens fitting convex portion or a lens abutting convex portion provided on an outer peripheral fitting portion of a lens or a contact surface in an optical axis direction. According to the above, the dimension of the convex portion is modified to improve the lens holding accuracy.

Further, in the lens holding frame applied to the lens barrel disclosed in Japanese Patent Laid-Open No. 62-156607, flanges are arranged at equal angular intervals around the lens holding portion of the front first lens. Since the sink marks are formed on the inner periphery of the first lens, the portions contacting the outer periphery of the first lens are arranged at equal angular intervals, and a protrusion for applying the first lens in the optical ring direction is further provided. . On the other hand, regarding the second lens on the rear side, a fitting convex portion is provided on the outer circumference fitting portion, and further,
It adopts a structure in which a contact projection is provided on the contact part in the direction of the halo. Coaxiality and parallelism are secured by modifying the convex portion.

FIG. 13 is an exploded perspective view of the lens barrel, FIG. 14 is a longitudinal sectional view of the lens barrel, and a front view of a lens holding frame alone of the lens barrel of FIG. .

The lens barrel 70 is a lens holding frame 31.
And the first lens 32 held by the lens holding frame 31
And a second lens 33, and the lens holding frame 3
1 is provided with three divided flange portions 38a, b, c having screw insertion holes 38d, e, f on the front surface, and holding portions for the first lens 32 and the second lens 33 on the inner peripheral portion. There is.

The holding portion of the first lens 32 is provided with a fitting inner peripheral surface portion 34 and convex portions 35a, 35b, 35c for applying in the optical axis direction. The fitting inner peripheral surface portion 34 has a sink mark at a portion where the flange portions 38a, 38b, and 38c are located outside, and three portions other than the sink mark serve as a lens holding portion that contacts the lens. . Further, in the holding portion of the second lens 33, the lens outer peripheral fitting convex portions 36 are provided at three locations on the inner peripheral surface.
a, b, c and the convex portions 37a, b, c for applying in the optical axis direction
Is provided.

The lens barrel 70 has a structure in which the first lens 32 and the second lens 33 are fitted in, held in contact with and held by the holding portion of the lens holding frame 31, respectively.

Further, the one disclosed in Japanese Patent Laid-Open No. 9-61689 is one in which the lens holding frame is made uniform in thickness to suppress the deformation of the lens holding frame and improve the lens holding accuracy.

[0009]

However, in the lens holding frame disclosed in Japanese Patent Laid-Open No. 61-236513, Japanese Patent Laid-Open No. 62-2219 and Japanese Patent Laid-Open No. 62-156607 described above, In order to provide the lens fitting convex portion and the lens abutting convex portion, it is necessary to form a groove corresponding to the convex portion using a milling machine or a polishing machine in the molding die. Considering the accuracy of mounting the mold on the processing machine, 20
Since a processing error of about μm may occur, it is difficult to suppress the coaxiality of the plurality of lenses to 20 μm or less. It also takes time to modify the mold according to the quality of the molding. Further, even if thick-walled portions such as flanges are provided at equal intervals, it is not always the case that only the portions are recessed and the lenses abut at the equally-spaced portions.

Even when the lens holding frame has a uniform thickness like the lens barrel disclosed in Japanese Patent Laid-Open No. 9-61689, deformation may occur due to a gate or a slight dimensional deviation. When the portion has an oval shape, there is no backlash in the minor axis direction, and there is backlash in the major axis direction, which may hinder lens holding.

An object of the present invention is to provide a lens holding frame which is easy to mold the lens holding portion in the injection-molded lens holding frame and has good lens holding coaxiality and parallelism accuracy. is there.

[0012]

A lens holding frame according to claim 1 of the present invention is an injection-molded lens holding frame having an annular portion for holding a lens, the lens holding frame being provided on an outer peripheral surface of the annular portion. It has a plurality of thin portions and an inner peripheral surface provided in the annular portion for holding the lens, and the rattling of the lens is suppressed by the sink or deformation in the molding of the plurality of thin portions, and the concentricity is reduced. The parallelism accuracy can be improved.

A lens holding frame according to claim 2 of the present invention is
In the lens holding frame according to claim 1, in order to hold a plurality of the lenses, the lens holding frame has the inner peripheral surface and the plurality of thin portions for each of the plurality of lenses.

The lens holding frame according to claim 3 of the present invention is
In the lens holding frame according to claim 1 or 2, with respect to one of the lenses, the thin portions are located at equal intervals in the circumferential direction of the outer peripheral surface of the annular portion.

The lens holding frame according to claim 4 of the present invention is
In the lens holding frame according to claim 1 or 2, the thin portion is provided in at least three places in the annular portion.

A lens holding frame according to claim 5 of the present invention is
In a lens holding frame injection-molded to hold the lens, in order to receive the lens in the optical axis direction, a ring-shaped receiving surface orthogonal to the optical axis, or a ridge line around the optical axis. , The annular receiving surface,
Alternatively, the wall thickness between the outer peripheral surface and the annular receiving surface, or the outer peripheral surface as an outer shape orthogonal to the optical axis with a predetermined wall thickness separated from the peripheral edge line, or between the peripheral ridge lines is reduced. A plurality of thin portions, the lens, in the optical axis direction, a part of the annular receiving surface inside the thin portion, or a part of the circumferential ridge line inside the thin portion. Can be received.

A lens holding frame according to claim 6 of the present invention is
In a lens holding frame made of synthetic resin for holding and holding a plurality of lenses in predetermined positions, three or more and six or less thin-walled portions per lens are provided outside the fitting diameter of the lens at substantially equal angular intervals. The lenses are provided at substantially the same angular position.

The lens holding frame according to claim 7 of the present invention is
In the lens holding frame according to the sixth aspect, the same or a half number of thick portions as the thin portions are provided at substantially equal angular positions with respect to the respective lenses at approximately equal angular intervals.

The lens holding frame according to claim 8 of the present invention is
In a lens holding frame made of a synthetic resin that holds a plurality of lenses fixed at predetermined positions, three or more and six or less points per lens are arranged at substantially equal angular intervals on the back side of the contact surface in the optical axis direction of the lenses. The thin portions are provided at substantially the same angular position around the optical axis of each lens.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an exploded perspective view of a lens barrel to which the lens holding frame of the first embodiment of the present invention is applied,
FIG. 2 is a vertical sectional view of the lens barrel. FIG. 3 is a perspective view of the lens holding frame, and FIG. 4 is a view seen from the back side of the lens holding frame. FIG. 5 is a diagram showing an enlarged locus of the dimensional difference with respect to the nominal dimensional shape (true circle) of the lens holding inner peripheral surface of the molded product of the lens holding frame in FIG. In addition,
In the description of the lens barrel, the subject side is the front and the image forming side is the rear. The optical axis of the lens is the optical axis O.

As shown in FIG. 1 etc., the lens barrel 50 of the present embodiment includes a lens holding frame 1, a first lens 2 held on the front side of the lens holding frame 1, and a rear side of the lens holding frame 1. And a second lens 3 held by.

The lens holding frame 1 is an injection-molded member made of synthetic resin and has a substantially rotationally symmetrical shape about the optical axis O. As shown in FIGS. 3 and 4, the lens holding frame 1 has a fitting inner peripheral surface 9 which is an inner peripheral surface centered on the optical axis O into which the outer diameter portion of the first lens 2 is fitted on the inner peripheral surface of the annular portion. And an annular receiving surface 10 orthogonal to the optical axis O with which the rear end surface of the first lens 2 abuts, and an inner peripheral surface of the optical axis O center into which the outer diameter portion of the second lens 3 fits. An annular receiving surface 12 that has an inner peripheral surface 11 and a front side ridgeline 12a and is orthogonal to the optical axis O.
And flange portions 13a, 13b, 13c are provided on the outer circumference of the front end face. In addition, on the front side circumferential ridge line 12a,
The rear end surface of the second lens 3 contacts and is positioned.

Further, on the outer circumference of the annular portion of the lens holding frame 1,
Cut surfaces 5a, 5b, 5c parallel to the optical axis O and cut surfaces 6a, 6b, 6c orthogonal to the optical axis O are provided at three positions on the outer circumference in order to form a thin portion at three positions on the outer circumference. Cut surfaces 7a, 7b, 7c parallel to the optical axis O and cut surfaces 8a, 8b, 8c orthogonal to the optical axis O are provided at three positions on the outer circumference between the rear outer peripheral portions 1b. The cut surfaces 5a, 6a, 7a and 8a are arranged at the same angular position around the optical axis O. Similarly, the other cut surfaces 5b, 6b and 7
b and 8b, and the cut surfaces 5c, 6c, 7c and 8c are also arranged at the same angular position around the optical axis O, respectively.

The front outer peripheral portion 1a is provided with cam follower fitting holes 14a, 14b, 14c, and the cam followers 4a, 4 for driving the lens barrel 50 forward and backward.
b and 4c are fixed.

The thick portion between the cut surfaces 5a, 5b, 5c and the cut surfaces 6a, 6b, 6c and the fitting inner peripheral surface 9 and the annular receiving surface 10 is a relatively thin thin portion. To form. Similarly, the wall thickness between the cut surfaces 7a, 7b, 7c and the cut surfaces 8a, 8b, 8c and the fitting inner peripheral surface 11 and the annular receiving surface 12 should also be relatively thin. Form.

In the injection molding die of the lens holding frame 1, the fitting inner peripheral surfaces 9 and 11 and the annular receiving surfaces 10 and 1 are used.
The mold portion for molding 2 is composed of a cylindrical surface having no groove centered on the optical axis O and an end surface which is a flat surface having no groove orthogonal to the optical axis O.

When the lens holding frame 1 having the above-described shape is injection molded, the inner peripheral surface locus 9 of the fitting inner peripheral surfaces 9 and 11 thereof.
a and 11a are true circular loci 9b and 11 having nominal dimensions and shapes.
In contrast to b, a slight uneven locus is obtained as shown in the enlarged view of FIG. 5 due to the influence of deformation due to the difference in solidification time during molding and the difference in shrinkage amount.

That is, 3 of the fitting inner peripheral surface 9 on the inner side of the cut surfaces 5a, 5b, 5c, which are thin portions having a small shrinkage amount.
The points are slightly convex portions (3 points) toward the inner diameter side.

Similarly, 3 of the fitting inner peripheral surface 11 on the inner side of the cut surfaces 7a, 7b, 7c, which are thin portions having a small shrinkage amount.
The points are slightly convex portions (3 points) toward the inner diameter side.

On the other hand, the receiving surface loci of the annular receiving surfaces 10 and 12 similarly form a slight uneven portion due to the influence of deformation due to the difference in solidification time during molding and the difference in shrinkage amount.

That is, the cut surfaces 6a, 6b, 6c and the cut surfaces 8a, 8 forming the thin portion having a small shrinkage amount.
b, 8c each of the annular receiving surfaces 10, 12 on the front side portion
Places are slightly convex toward the optical axis O direction (3 places each)
To form.

Incidentally, three convex portions on the fitting inner peripheral surface 9 and three convex portions on the fitting inner peripheral surface 11, and further,
The three convex portions of the annular receiving surface 10 and the three convex portions of the annular receiving surface 12 are formed at substantially the same angular position around the optical axis O direction. Also, the annular receiving surface 1
The circumferential ridgeline 12a also forms a similar convex ridge locus following the convex portion 2 of FIG.

In the lens barrel 50 of the present embodiment having the above-described structure, when the first lens 2 and the second lens 3 are assembled to the lens holding frame 1, the outer circumferences of the first, second lenses 2 and 3 are , The fitting inner peripheral surfaces 9 and 11 respectively come into contact with the molding convex portions located at the substantially three-divided positions, and are fitted into the fitting inner peripheral surfaces 9 and 11 without backlash. Further, the optical axis O of the first lens 2 is
The rear side in the direction is held in contact with the convex portion on the molding at the substantially three-divided position of the annular receiving surface 10 without backlash. Similarly, the rear surface side of the second lens 3 in the direction of the optical axis O is held in contact with the convex portion on the molding at the substantially three-divided position of the inner circumferential ridgeline 12a of the annular receiving surface 12 without backlash. . The first and second lenses 2 and 3 are adhesively fixed to the lens holding frame 1 under the holding state.

According to the lens barrel 50 of this embodiment described above, the outer peripheral surface and the rear end surface of the plurality of lenses 2 and 3 are fitted to the inner peripheral surface, the annular receiving surface, or the uneven thickness on the circumferential ridge line. The protrusions are held by the three convex portions at 120 ° intervals, but the deviation of the positions of the three convex portions due to the molding is extremely small. Therefore, the plurality of lenses 2 and 3 come into contact with these convex portions and are supported accurately in a stable state without backlash. Further, since the thin-walled portions of the plurality of lenses 2 and 3 are arranged at the same angular position in the circumferential direction, the sink mark and the deformation at the time of molding have an approximate shape, and the parallelism between the receiving surfaces 10 and 12 is improved.

The lens holding frame 1 has a shape that is substantially rotationally symmetric. As a result, the convex portion, which actually contacts the outer peripheral surface of the lens, is positioned without being biased to the substantially equally divided portion as described above, and it is possible to prevent the backlash from increasing in only one direction. . In addition, the first lens 2 and the second
Since the uneven thickness portion of the fitting inner peripheral surface portion which is the fitting portion of the two lenses of the lens 3 is arranged at the same angular position in the circumferential direction, the deformation due to the molding becomes an approximate shape, and the first and second lenses 2, 3
The misalignment between the lenses in the lens group becomes small.

If the deformation due to molding does not occur completely rotationally symmetrically, even if the misalignment between the lenses in the first and second lenses 2 and 3 becomes small, it will be slightly from the center of the design designation. There is a possibility of deviation. However, in general, eccentricity between groups often has less effect on performance than eccentricity within a group, and when it has a large effect on performance, an adjustment mechanism is generally provided, so A slight deviation from the center does not matter.

Further, there may be a case where the fitting diameter of the fitting inner peripheral surface, which is the design name, and the performance of the molded product are slightly different due to the deformation in molding, but the first and second lenses 2 and 3 are made of glass lenses. In this case, it is easy to adjust the centering diameter on the lens side to match. In addition, if the lenses 2 and 3 are molded products and it is difficult to change the outer diameter,
It is necessary to correct and mold the mold part having the fitting diameter on the fitting inner peripheral surface of the lens holding frame 1. However, the modification of the mold can be performed by lathe processing, and the adjustment can be performed accurately. However, since the correction process of the mold can be performed only in the direction of reducing the fitting diameter of the fitting inner peripheral surface, when it is difficult to change the outer diameter of the lens as described above, the deformation of the lens holding frame 1 is performed. Considering this, it is necessary to make the fitting diameter of the fitting inner peripheral surface slightly larger.

Further, in the lens barrel 50 of this embodiment,
The flange portions 13a, 13 are provided on the outer circumference of the front surface of the lens holding frame 1.
b and 13c are provided for the purpose of narrowing the gap between the lens holding frames to prevent light leakage. Although this portion does not become thin in the radial direction, it does not affect the effects of the present invention because it is away from the fitting portion of the lens.

Next, the lens barrel of the second embodiment of the present invention will be described with reference to FIGS.

FIG. 6 is an exploded perspective view of a lens barrel to which the lens holding frame according to the second embodiment of the present invention is applied.
FIG. 12 is a cross-sectional view showing the BB cross section of FIG. 11 of the lens barrel. FIG. 8 is a cross-sectional view showing the CC cross section of FIG. 11 of the lens barrel. FIG. 9 is a perspective view of the lens holding frame as viewed from the back side. FIG. 10 is a view of the lens holding frame as seen from the front side, and FIG. 11 is a view of the lens barrel as seen from the back side. FIG. 12 is a diagram showing an enlarged locus of a dimensional difference with respect to a perfect circular locus of the nominal dimension shape of the lens holding inner peripheral surface of the molded product of the lens holding frame of FIG.

As shown in FIG. 6 and the like, the lens barrel 60 of this embodiment includes a lens holding frame 15, a first lens 16 held on the front side of the lens holding frame 15, and a lens holding frame 15.
It has a second lens 17 held on the rear side and a sleeve 29 into which a rod (not shown) for guiding the lens holding frame 15 forward and backward is slidably fitted.

The lens holding frame 15 is an injection-molded member made of synthetic resin, and is a member having a substantially vertical and horizontal symmetrical shape about the optical axis O. This lens holding frame 1 is shown in FIGS.
As shown in 0 and 11, the first lens 1
The outer diameter portion of 6 is fitted, and the fitting inner peripheral surface 21, which is the inner peripheral surface of the center of the optical axis O, comes into contact with the rear surface portion of the first lens 16, and the optical axis O
A ring-shaped receiving surface 22 that is orthogonal to and the outer diameter portion of the second lens 17 are fitted, and a fitting inner peripheral surface 23 that is an inner peripheral surface of the optical axis O center.
And an annular receiving surface 24 that is in contact with the rear surface portion of the second lens 17 and is orthogonal to the optical axis O. Strictly speaking,
The rear surface portions of the first and second lenses 16 and 17 come into contact with the circumferential ridge lines on the front inner circumferences of the annular receiving surfaces 22 and 24, and the optical axes of the lenses 16 and 17 are positioned. .

On the outer periphery of the annular portion of the lens holding frame 15, a fork-shaped notch guide portion 1 into which a rod is fitted at the upper and lower positions.
8 and the sleeve fixing portion 19 into which the sleeve 29 is fitted and adhesively fixed, and the optical axis O at an outer peripheral four-divided position that is divided into four equal parts around the optical axis O as an outer surface for forming a thin portion. The four parallel front concave concave portions 25a, 25b,
25c, 25d and rear arcuate concave surface portions 27a, 27b, 27 at four divided positions at the same angular position as the front concave surface portions.
c, 27d, and cut surfaces 26a, 26b, 26c, 26d orthogonal to the optical axis O at the rear positions of the front concave surface portions,
Cut surfaces 28a, 28b, 28c and 28d orthogonal to the optical axis O are provided at the rear positions of the respective rear concave surface portions. A cam follower 20 is formed outside the sleeve fixing portion 19.

As shown in FIG. 7, on the inner diameter side of the notch guide portion 18, in addition to the thick portion 18a necessary for the guide portion 18, a padding is provided to correspond to the thick portion 19a of the sleeve fixing portion 19. The part 18b is further provided.

The front arcuate concave surface portions 25a, 25b, 2
5c, 25d and cut surfaces 26a, 26b, 26c,
The thick portion between 26d and the fitting inner peripheral surface 21 and the annular receiving surface 22 forms a thin portion having a relatively small thickness. Similarly, the rearward arcuate concave surface portions 27a, 27b, 27c,
27d and cut surfaces 28a, 28b, 28c, 28d
And a thick portion between the fitting inner peripheral surface 23 and the annular receiving surface 24 forms a thin portion having a relatively small thickness.

In the injection mold of the lens holding frame 15, the fitting inner peripheral surfaces 21 and 23 and the annular receiving surface 2 are used.
The mold portion for molding 2, 24 is composed of a cylindrical surface having no groove at the center of the optical axis O and an end surface which is a plane having no groove orthogonal to the optical axis O.

When the lens holding frame 15 having the above-mentioned shape is injection-molded, the inner peripheral surface loci 21a and 23a of the fitting inner peripheral surfaces 21 and 23 are the same as those at the time of molding with respect to the nominal size circular loci 21b and 23b. Due to the difference in the amount of deformation or contraction, the locus becomes a slight unevenness as shown in the enlarged view of FIG.

That is, before forming the thin portion having a small shrinkage amount, the fitting inner peripheral surface 21 of the inner portion of the rearward arcuate concave surface portion,
Each of the four points 23 is a slight convex portion (four points) toward the inner diameter side.

Similarly, the annular receiving surface 2 of the inner portion such as the cut surfaces 26a and 28a forming the thin portion having a small shrinkage amount.
Four points 2 and 24 are slightly convex portions (four points) toward the front side in the optical axis O direction.

It should be noted that 3 on the annular receiving surfaces 21 and 23.
The respective convex portions at the portions and the respective convex portions at the three positions of the annular receiving surfaces 22 and 24 are formed at substantially the same angular position around the optical axis O direction. Further, following the convex portions of the annular receiving surfaces 22 and 24, the respective circumferential ridge lines have the same slight optical axis O.
Form a convex ridge locus in the direction.

In the lens barrel 60 of the present embodiment having the above-mentioned structure, the first lens 1 is attached to the lens holding frame 15.
6, and when assembling the second lens 17, the outer circumferences of the first and second lenses 16 and 17 are fitted to the fitting inner peripheral surfaces 21 and 2.
Each of No. 3 and No. 3 abuts on the above-mentioned molding convex portion located at approximately four equal positions and is held without play. Further, the rear surfaces of the first and second lenses 16 and 17 in the optical axis O direction are held in contact with the convex portions on the molding which are located at approximately four equal positions of the circumferential ridgelines of the annular receiving surfaces 22 and 24. It The first and second lenses 16 and 17 hold the lens holding frame 15 under the holding state.
It is fixed by adhesion.

According to the lens barrel 60 of the present embodiment described above, the outer peripheral surfaces and the rear end surfaces of the plurality of lenses 16 and 17 are fitted to each other as in the case of the lens barrel 50 of the first embodiment. It is fitted and abutted and held in four convex portions in the inner circumferential direction and the optical axis direction at 90-degree intervals that are formed along the circumference of the inner circumferential surface or the annular receiving surface and are formed by uneven thickness. Therefore, the deviation of the holding position is extremely small, and the plurality of lenses 16 and 17 can be accurately supported in a stable state without rattling.

Also, when the position of the convex portion of the fitting inner peripheral surface or the annular receiving surface is corrected by a die, it can be corrected by lathe processing, and can be corrected easily with high accuracy.

Like the lens holding frame 15 of this embodiment, the guide portion 18 and the sleeve fixing portion 19 are vertically arranged for functional reasons.
When the thick-walled portions are required, these thick-walled portions are in symmetrical positions, and therefore, even if the thin-walled portions are provided at three places like the lens holding frame 1 of the first embodiment, the thick-walled portions have a rotationally symmetrical shape. I can't. In such a case, the lens holding frame structure of this embodiment can be applied.

That is, the lens holding frame 15 of the present embodiment.
Then, as described above, four thin portions are provided. That is, on the outside of the fitting portion (fitting inner peripheral portion) of the first lens 16, there are thin-walled portions formed by the arcuate concave surface portions 25a to 25d at 90-degree intervals between the guide portion 18 and the thick-walled portion of the sleeve fixing portion 19. It is provided so as to be sandwiched between. Further, the arcuate concave surface portion 2 arranged at the same angle as the arcuate concave surface portions 25a to 25d on the outer side of the fitting portion (fitting inner peripheral portion, receiving surface) of the second lens 17.
A thin portion formed by 7a to 27d is provided. Ideally, it is desirable to provide four thick-walled parts as well, but as described above, the lens holding frame supported by the guide shaft often has a driving mechanism such as a motor or electric parts arranged around it. However, it is not always possible to provide the thick portion. Therefore, in the lens holding frame 15 of the present embodiment, only the upper and lower cutout guide portions 18 and the sleeve fixing portion 19 are thick portions. Due to the uneven thickness, the cooling time and the like change, and slight deformation and sink marks occur on the fitting inner peripheral surfaces 21 and 23.

FIG. 12 is an enlarged view of the locus of the fitting diameter (fitting inner peripheral surface) of the molded lens holding frame, and shows the locus of the fitting inner peripheral surface 21 on the first lens 16 side. 21a,
The fitting inner peripheral surface 23 of the second lens 17 is shown by a locus 23a. The trajectories 21b and 23b are true circular trajectories of the nominal size and shape. Corresponding to 4 thin parts and 2 upper and 2 thick parts, the shape is almost symmetrical. As a result, the portion actually hitting the lens is divided into approximately four parts, and the play does not increase in one direction. Also,
Two fitting inner peripheral portions 21 of the first and second lenses 16 and 17,
Since the eccentricity with respect to 23 is arranged at the same angular position, the deformation of sink marks and the like causes the fitting inner peripheral portion 2 of the first and second lenses 16 and 17 to be deformed.
An approximate shape is formed between Nos. 1 and 23, and the misalignment between the lenses in the group can be suppressed to be small. Note that other items such as the receiving of the lens in the optical axis direction and the influence of deformation are the same as in the case of the first embodiment.

In the lens holding frames 1 and 15 of the above-described first and second embodiments, the thin portions are three or four, but more thin portions may be arranged.
However, if too much, it becomes unstable where the lens is applied, so 6 or less is desirable. In addition, it is preferable that the number of thick portions is equal to or half that of the thin portions, because desired deformation cannot be obtained even if the thick portions are too large or too small. If the change in wall thickness is rapid, the deformation may become too large, so it is better that the change in wall thickness is gentle.

Further, in the embodiment of the present invention, the deformation of the molded product is made into a desired shape depending on the shape, but the deformation may occur depending on the position and the number of gates other than the above shape. Therefore, in order to prevent the effect of the present invention from being hindered by the gate, it is desirable that the number of gates is a multiple of the number of thin portions or a divisor other than 1 and arranged at substantially equal angular intervals. However, the number and arrangement of the above gates are not essential conditions for the present invention.

[0059]

As described above, according to the present invention, even if the mold for the portion that determines the position of the lens is processed only by a lathe having high processing accuracy, the deformation due to molding becomes functionally desirable. The coaxiality and parallelism of a plurality of lenses can be maintained with high accuracy. And, an appropriate number is provided outside the fitting inner peripheral surface of the lens, or an uneven thickness portion is provided at an appropriate position, and an appropriate number or an appropriate position is provided on the back side of the receiving surface in the optical axis direction of the lens. By providing the uneven thickness portion in the lens holding frame, it is possible to obtain a lens holding frame which is in a sink or deformed state at the time of molding so as to reduce the rattling of the lens and improve the coaxiality and the parallelism.

[Brief description of drawings]

FIG. 1 is an exploded perspective view of a lens barrel to which a lens holding frame according to a first embodiment of the present invention is applied.

FIG. 2 is a vertical cross-sectional view of the lens barrel of FIG.

3 is a perspective view of the lens holding frame applied to the lens barrel of FIG. 1. FIG.

FIG. 4 is a view of the lens holding frame of FIG. 3 seen from the back side.

5 is a diagram showing an enlarged locus of a dimensional difference with respect to a nominal dimensional shape (true circular locus) of the lens holding inner peripheral surface of the molded product of the lens holding frame of FIG. 3;

FIG. 6 is an exploded perspective view of a lens barrel to which a lens holding frame according to a second embodiment of the present invention is applied.

7 is a diagram showing a cross section of the lens barrel of FIG. 6 as taken along the line BB in FIG.

8 is a view showing a cross section of the lens frame of FIG. 6 taken along the line CC in FIG.

9 is a perspective view of the lens holding frame of FIG. 6 as viewed from the back side.

10 is a view of the lens holding frame of FIG. 6 seen from the front side.

11 is a view of the lens barrel of FIG. 6 as viewed from the back side.

12 is a diagram showing an enlarged locus of a dimensional difference with respect to a nominal dimension circular locus (true circle) of the lens holding inner peripheral surface of the molded product of the lens holding frame in FIG. 6;

FIG. 13 is an exploded perspective view of a conventional lens barrel.

14 is a vertical cross-sectional view of the lens barrel of FIG.

15 is a front view of a lens holding frame applied to the lens barrel of FIG.

[Explanation of symbols]

1, 15 ... Lens holding frames 5a, 5b, 5c, 6a, 6b, 6c, 7a, 7b, 7
c ... Cut surface (outer surface, thin portion) 9, 11, 12, 23 ... Fitting inner peripheral surface (inner peripheral surface provided in annular portion) 10, 12, 22, 24 ... Annular receiving surface 12a ... Circulation Ridges 25a, 25b, 25c, 25d ... Front arcuate concave surface portion (outer surface, thin portion) 26a, 26b, 26c, 26d, 28a, 28b, 2
8c, 28d ... Cut surface (outer surface, thin portion) 27a, 27b, 27c, 27d ... Rear arc-shaped concave surface portion (outer surface, thin portion)

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[Procedure amendment]

[Submission date] June 5, 2002 (2002.6.5)

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] 0003

[Correction method] Change

[Correction content]

Further, in the lens holding frame applied to the lens barrel disclosed in Japanese Patent Laid-Open No. 62-156607, flanges are arranged at equal angular intervals around the lens holding portion of the front first lens. Since the sink marks are formed on the inner circumference of the first lens, the parts contacting the outer circumference of the first lens should be equiangularly spaced, and further, a projection for applying the first lens in the optical axis direction should be provided. There is. On the other hand, regarding the second lens on the rear side, a fitting convex portion is provided on the outer circumference fitting portion, and further,
It employs a structure in which a contact projection is provided on the contact part in the optical axis direction. Coaxiality and parallelism are secured by modifying the convex portion.

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0034

[Correction method] Change

[Correction content]

According to the lens barrel 50 of this embodiment described above, the outer peripheral surface and the rear end surface of the plurality of lenses 2 and 3 are fitted to the inner peripheral surface, the annular receiving surface, or the uneven thickness on the circumferential ridge line. It is held by the convex portion of the three locations 120 degrees apart occurring, deviation of the position of the convex portion of the three by the molding, it quite small
Ku made. Therefore, the plurality of lenses 2 and 3 come into contact with these convex portions and are supported accurately in a stable state without backlash. Further, since the thin-walled portions of the plurality of lenses 2 and 3 are arranged at the same angular position in the circumferential direction, the sink mark and the deformation at the time of molding have an approximate shape, and the parallelism between the receiving surfaces 10 and 12 is improved.

[Procedure 3]

[Document name to be amended] Statement

[Correction target item name] 0050

[Correction method] Change

[Correction content]

It should be noted that 4 on the annular receiving surfaces 21 and 23.
The respective convex portions of the four positions of the convex portion and the annular receiving surface 22, 24 of the places, are formed at substantially the same angular position about the optical axis O direction. Further, following the convex portions of the annular receiving surfaces 22 and 24, the respective circumferential ridge lines have the same slight optical axis O.
Form a convex ridge locus in the direction.

Claims (8)

[Claims] 1. An injection-molded lens holding frame having an annular portion for holding a lens, comprising: a plurality of thin-walled portions provided on an outer peripheral surface of the annular portion; and the annular portion for holding the lens. An inner peripheral surface is provided, and the lens is positioned by the inner peripheral surface portion inside the plurality of thin portions. 2. The lens holding frame according to claim 1, wherein in order to hold a plurality of the lenses, the inner peripheral surface and the plurality of thin portions are provided for each of the plurality of lenses. 3. The lens according to claim 1, wherein the thin portions are located at equal intervals in the circumferential direction of the outer peripheral surface of the annular portion with respect to one of the lenses. Lens holding frame. 4. The lens holding frame according to claim 1, wherein the thin portion is provided in at least three places on the annular portion. 5. A lens holding frame injection-molded for holding a lens, wherein the lens is received in the direction of the optical axis thereof, and therefore, the ring-shaped receiving surface orthogonal to the optical axis or the optical axis is centered. And a circular ridge line, or the annular receiving surface, or an external surface as an external shape orthogonal to the optical axis with a predetermined thickness separated from the circular ridge line, the external surface and the annular receiving surface, Or a plurality of thin-walled portions having a reduced wall thickness between the circumferential ridges, and the lens is a part of the annular receiving surface inside the thin-walled portion in the optical axis direction, or A lens holding frame which can be received by a part of the circumferential ridgeline inside the thin portion. 6. A synthetic resin lens holding frame for fixing and holding a plurality of lenses in predetermined positions, wherein the number of the lenses is 3 or more and 6 or less per lens at substantially equal angular intervals outside the fitting diameter of the lenses. A lens holding frame, characterized in that the thin-walled portions are provided at substantially the same angular position of each lens. 7. A thin-walled portion having the same number or a half number of thick-walled portions is provided at substantially equal angular positions with respect to the respective lenses at substantially equal angular intervals.
The lens holding frame described. 8. A lens holding frame made of synthetic resin for holding and holding a plurality of lenses in predetermined positions, wherein three positions are provided for each lens on the back side of the contact surface of the lens in the optical axis direction at substantially equal angular intervals. A lens holding frame, characterized in that at least six thin portions are provided at substantially the same angular position around the optical axis of each lens.