JP2000019371A - Lens holding device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To surely hold a lens and to enable it to be removed even after it is held by using a lens pressing ring made of resin. SOLUTION: This lens holding device is constituted so that the lens 1 is held between the lens holding part 21 of a lens barrel 2 and the lens pressing ring 3 by engaging the lens 1 with the holding part 21 and inserting the ring 3 in the lens barrel 2. The ring 3 is made of a black resin material and provided with an elastic part 33 which can be elastically displaced in a radial direction. Besides, the ring 3 is provided with a fixing means 41 fixing the ring 3 through the elastic part 33 at a lens holding position in the lens barrel 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a lens holding device for holding a lens in a lens barrel.

[0002]

2. Description of the Related Art Conventionally, a lens incorporated in a lens barrel is positioned by an inner wall constituting the lens barrel in a radial direction of the lens barrel. It is necessary to use another means in the direction orthogonal to the radial direction of the lens barrel.

For example, as described in Japanese Patent Application Laid-Open No. 56-92511, there is a means for directly fixing a lens in a lens barrel with an adhesive.

In this case, in addition to the problem that the adhesive is poured between the lens barrel and the outer peripheral edge of the lens, there is a problem that the lens cannot be easily removed after the bonding. There is a point.

Further, as described in Japanese Patent Application Laid-Open No. 62-125308, a screw member penetrating from the outside to the inside of the lens barrel is screwed into the lens barrel and protrudes inside the lens barrel. There is a means for fixing the lens at the tip of the screw member.

In the case of this means, it is necessary to secure a portion for screwing the screw member into the lens barrel, so that there is a problem that miniaturization of the lens barrel is limited.

Further, as described in Japanese Patent Application Laid-Open No. 62-234112, a lens holding portion and a lens holding ring holding portion are formed in a lens barrel, and a lens and a lens holding member are provided in the lens barrel. There is a means for fixing the lens in a state of being sandwiched between the lens holding portion and the lens holding ring by incorporating the rings in order and fixing the lens holding ring to the lens holding ring holding portion with an adhesive.

In this case, Japanese Patent Application Laid-Open No. 56-925 is disclosed.
As compared with the means described in Japanese Patent Application Laid-Open No. 11-127, and Japanese Patent Application Laid-Open No. 62-125308, the operation of applying the adhesive is easier than the operation of pouring the adhesive between the lens and the lens barrel. Since it is not necessary to secure a portion for screwing the members, the lens barrel can be downsized.

[0009]

However, in the means disclosed in Japanese Patent Application Laid-Open No. Sho 62-234112, the distance between the lens holding portion and the lens holding ring is determined by the position where the lens holding ring holding portion is formed. Unless the lens holding ring holding portion is formed at an accurate position, there is a problem that rattling occurs between the lens holding portion and the lens holding ring. Further, there is a problem that the lens cannot be easily removed after bonding, as in the means described in JP-A-56-92511.

Further, the lens press ring is formed of a metal plate having a plurality of pointed portions protruding from the periphery of the lens press ring, and the lens press ring is inserted into the lens barrel. When the pointed portion elastically bites into the inner peripheral surface of the lens barrel and locks while holding the lens in contact with the lens, the problem described above was solved. The holding ring must be made of a metal plate that can bite into the lens barrel. If the surface is not painted black, the external light reflected by the lens holding ring leaks into the lens barrel. In addition, there is also a problem that the cost of materials and the like is high because of the metal plate.

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and a lens using a resin lens holding ring which can save the trouble of performing black coating by using a black resin material. Can be securely held, and the lens can be removed even after holding the lens.
It is an object of the present invention to provide a lens holding device capable of reducing the restriction on downsizing of a lens barrel.

[0012]

According to a first aspect of the present invention, there is provided a lens holding apparatus comprising: a lens barrel having a lens holding portion for holding a lens inside; and an elastic portion capable of being elastically displaced in a radial direction. A lens holding ring made of resin which is inserted into the lens barrel and holds the lens between the lens holding portion, and the lens holding ring is fixed at the lens holding position in the lens barrel via the elastic portion. And fixing means.

When the lens holding ring is inserted into the lens barrel, a fixing means is provided at a position for holding the lens in the lens barrel via an elastic portion which can be elastically displaced in the radial direction of the lens holding ring. Since the lens is fixed to the lens barrel, the lens in the lens barrel can be securely held, and the lens can be removed even after the lens is held, thereby reducing the limitation on downsizing of the lens barrel. In addition, since the lens holding ring can be formed from a resin material, it is necessary to make the lens holding ring black, for example, in order to prevent light leakage. However, the use of a black resin material makes it possible to save the trouble of performing black coating.

According to a second aspect of the present invention, there is provided the lens holding device according to the first aspect, wherein the lens pressing ring is formed along the circumferential direction on the inner diameter side of the elastic portion so that the elastic portion has a radial elasticity. It has a hole that allows displacement.

Since a hole is formed along the circumferential direction on the inner diameter side of the elastic portion of the lens holding ring, the hole allows the elastic displacement of the elastic portion in the radial direction.

According to a third aspect of the present invention, there is provided the lens holding device according to the first or second aspect, wherein the fixing means includes an engaging portion projecting from an elastic portion of the lens pressing ring in an outer diameter direction, and It has an engagement hole of the lens barrel with which the engagement portion is engaged.

The fixing means has an engaging portion projecting from the elastic portion of the lens holding ring in the outer diameter direction, and an engaging hole of the lens barrel with which the engaging portion is engaged. Therefore, the attachment / detachment of the engagement portion and the engagement hole due to the elastic displacement of the elastic portion in the radial direction allows the lens press ring to be securely fixed in the lens barrel and easily removed.

According to a fourth aspect of the present invention, there is provided the lens holding device according to the first or second aspect, wherein the fixing means projects from the inside of the lens barrel and engages with the elastic portion of the lens pressing ring. It has a part.

Since the fixing means has a projection projecting from the inside of the lens barrel and engaging with the elastic portion of the lens pressing ring, the elastic portion is elastically displaced in the radial direction of the elastic portion. By attaching and detaching the projection and the projection, the lens holding ring can be securely fixed in the lens barrel and can be easily removed.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the lens holding device of the present invention will be described below with reference to the drawings.

FIGS. 1 to 4 show a first embodiment. FIG. 1 is a sectional view of a lens holding device, FIG. 2 is a sectional view showing an enlarged part of the lens holding device, and FIG. FIG. 4 is a plan view, and FIG. 4 is a cross-sectional view of the lens holding ring.

In the following description, the upper side in each figure is the incident direction of the light beam from the subject, this direction (upper side) is the front side, and the opposite direction (lower side) is the rear side.

In FIG. 1, reference numeral 1 denotes a lens, 2 denotes a lens barrel in which the lens 1 is incorporated, and 3 denotes a lens holder for fixing and holding the lens 1 incorporated in the lens barrel 2 in the lens barrel 2. It is a ring.

The lens 1 has a lens portion 11 in a central region and a flange portion 12 formed around the lens portion. The flange portion 12 has an outer peripheral surface 12a parallel to the optical axis, a front surface 12b perpendicular to the optical axis and parallel to each other, and a rear surface 12c.

The lens barrel 2 is formed in a cylindrical shape with a resin material such as polycarbonate. A lens holding portion (lens fitting portion) 21 for fittingly holding the flange portion 12 of the lens 1 from the rear surface 12c side on the inner peripheral surface of the lens barrel 2, and is fitted to the lens holding portion 21. Lens holding ring 3 for fixing and holding lens 1 in lens holding portion 21
And a lens holding ring holding portion 22 for holding the lens.

Lens holding part 21 and lens holding ring holding part 22
Is formed of two front and rear steps formed with the step surface facing forward, the rear step is a lens holding part 21, and the front step is a lens holding ring holding part 22. .

The lens holding portion 21 has a step surface 21a and a side wall surface 21b which is a step between the lens holding ring holding portion 22, and the step surface 21a and the side wall surface 21b form the flange portion 12 of the lens 1. The lens 1 is configured to be positioned in the optical axis and in a direction perpendicular to the optical axis by fittingly holding the lens from the rear side and the periphery.

That is, the step surface 21a is formed on the rear surface of the flange portion 12.
The lens 1 is positioned in the optical axis direction by abutting the lens 1 at the rear side in the optical axis direction by contacting the lens 12c, and the lens 1 is orthogonal to the optical axis by the side wall surface 21b abutting on the outer peripheral surface 12a of the flange portion 12. It is configured to perform direction positioning.

The inner diameter of the side wall surface 21b is adjusted in the direction perpendicular to the optical axis of the lens 1 so that the flange 12
Are set to a diameter that can be fitted without play. Since the light beam transmitted through the lens 1 passes through the hole on the optical axis side of the step surface 21a, the width of the step surface 21a is set so that vignetting of the light beam does not occur. The width of the side wall surface 21b in the direction along the optical axis,
That is, the step width between the lens holding portion 21 and the lens holding ring holding portion 22 is formed to be smaller than the thickness of the flange portion 12, and the lens 1 is fitted to the lens holding portion 21.
The front surface 12b of the lens holding ring 22 is set to protrude forward from the step surface 22a of the lens holding ring holding portion 22.

The lens holding ring holding portion 22 has a stepped surface 22a and a side wall surface 22b. By holding the periphery of the lens holding ring 3 by the side wall surface 22b in a fitting manner, the lens holding ring 3 is moved along the optical axis. It is configured to be positioned and held in a direction orthogonal to. Engaging holes 22c are formed in the side wall surface 22b at regular intervals at a plurality of locations on the circumference to be engaged with an engaging portion of the lens press ring 3 described below.

Next, the lens holding ring 3 will be described with reference to FIGS.

The lens pressing ring 3 is a radially wide annular plate having a hole 31 at the center, and is formed of, for example, a black resin material such as polycarbonate.

The outer diameter (3r1) of the lens retaining ring 3 and the side wall surface
The inner diameter of 22b is a diameter that allows the lens holding ring 3 to be incorporated into the side wall surface 22b without any gap.

The hole 31 of the lens holding ring 3 is formed to be larger than the outer diameter of the lens part 11 but smaller than the outer diameter of the flange part 12. Therefore, the lens portion 11 is
, But the front surface 12b of the flange portion 12 is configured to abut the lens pressing ring 3.

The lens holding ring 3 has a plurality of holes 32 having a long shape extending in the circumferential direction at equal intervals. In the present embodiment, three holes 32 having a central angle of 60 ° with respect to the center of the lens holding ring 3 are formed at equal intervals.

By forming the hole 32 in the lens holding ring 3, an outer portion of the lens holding ring 3 in which the hole 32 is formed is formed as an elastic portion 33. That is, the formation of the hole 32 allows the elastic portion 33 to be elastically deformed toward the hole 32 by the elasticity of the resin material forming the lens holding ring 3.

Outside the elastic portion 33, a lens holding ring holding portion is provided.
An engagement portion 34 that engages with an engagement hole 22c formed in the nozzle 22 is formed. The front surface 34f and the rear surface of this engagement portion 34
34r is formed as an inclined surface in which the front surface 34f is inclined rearward, and the rear surface 34r is inclined forward. In this embodiment, the surface 34f is inclined rearward at an inclination of 35 °, and the surface 34r is inclined forwardly at an inclination of 45 °.

The lens is formed by an engaging portion 34 protruding from the elastic portion 33 of the lens pressing ring 3 in the outer diameter direction and an engaging hole 22c of the lens barrel 2 with which the engaging portion 34 is engaged. A fixing means 41 for fixing the press ring 3 at the lens holding position in the lens barrel 2 via the elastic portion 33 is configured.

At the inner edge of the hole 31, there is formed a contested portion 31a which contests the upper half of the inner peripheral edge inward. The contested portion 31a is formed in a rectangular shape such that the peripheral portion of the lens portion 11 enters the lower portion thereof, and the inner peripheral diameter of the hole portion 31 increases from the rear side toward the front side on the upper surface side. It is formed on an inclined surface so as to open.

Next, the operation of the present embodiment will be described.

First, the incorporation of the lens 1 into the lens barrel 2 will be described.

The lens 1 is dropped into the lens barrel 2 from the front opening of the lens barrel 2 with the flange 12 facing backward, and the flange 12 of the lens 1 is
Fit into 21. By fitting the flange portion 12 to the lens holding portion 21, positioning in the optical axis direction and the radial direction is performed.

Next, the incorporation of the lens holding ring 3 into the lens barrel 2 will be described.

The outer diameter (3r 2) of the lens holding ring 3 including the engaging portion 34 is set to the side wall surface 22 b of the lens holding ring holding portion 22.
Is larger than the inner diameter of
Interference with the front edge of the lens 22 prevents its insertion into the lens holding ring holding portion 22.

The elastic portion 33 in which the engaging portion 34 is formed can elastically bend toward the inner diameter side, so that the lens pressing ring 3 holds the lens pressing ring against the elastic force of the elastic portion 33. Part 22
Forcibly pushed into the lens barrel 2, it can be put into the lens barrel 2.

Since the rear surface 34r of the engaging portion 34 is inclined forward, the engaging portion 34 is guided by the surface 34r with respect to the front edge of the lens holding ring holding portion 22. It is elastically deformed smoothly to the inner diameter side.

The lens pressing ring 3 is inserted further rearward while resisting the pressing force of the elastic portion 33 against the side wall surface 22b of the engaging portion 34, and the position where the lens pressing ring 3 abuts on the flange portion 12 is reached. Complete the insertion with.

Here, the engagement hole 22 of the lens holding ring holding portion 22
c indicates that when the lens holding ring 3 is inserted until it comes into contact with the flange portion 12, the front edge 22 c 1 of the engagement hole 22 c is engaged with the engagement portion.
Engagement hole 22 so as to abut on the front surface 34f of
The position and size of c are set.

By forming the engagement hole 22c in this manner,
When the lens holding ring 3 is inserted to a position where it comes into contact with the flange portion 12, the engaging portion 34 enters the engaging hole 22c,
22c1 will abut surface 34f.

That is, since the front surface 34f of the engaging portion 34 is inclined rearward, the engaging portion 34 is formed at the edge 22 of the engaging hole 22c.
The elastic force of the elastic portion 33 is applied to the rear of the c1 to engage the engaging hole 22c.

Therefore, the lens holding ring 3 is
Is fixedly held in the lens barrel 2 in a state where is pressed backward.

The width of the side wall surface 21b in the direction along the optical axis is formed smaller than the thickness of the flange portion 12 of the lens 1. Since the front surface 12b of the flange portion 12 projects forward from the step surface 22a of the lens holding ring holding portion 22, the flange portion 12 is sandwiched between the step surface 21a and the lens holding ring 3.

The outer diameter (3r1) of the lens holding ring 3
Has a diameter that can be incorporated into the side wall surface 22b without play, so that the lens holding ring 3 is held in the lens holding ring holding portion 22 without being eccentric with respect to the optical axis.

Incidentally, the peripheral portion of the lens 1 is
Of the outside light can be prevented.

As described above, when the lens holding ring 3 is inserted into the lens barrel 2, the fixing means 41 elastically expands the lens holding ring 3 in the radial direction at the position for holding the lens 1 in the lens barrel 2. Since the lens 1 is fixed to the lens barrel 2 via the displaceable elastic portion 33, the lens 1 in the lens barrel 2 can be securely held, and the lens 1 can be removed even after the lens 1 is held. It is also possible to reduce the limitation on downsizing of the lens barrel 2. Moreover, since the lens holding ring 3 can be formed from a resin material, the use of a black resin material can save the trouble of performing black coating.

Further, since the hole 32 is formed along the circumferential direction on the inner diameter side of the elastic portion 33 of the lens press ring 3, the elastic displacement of the elastic portion 33 in the radial direction can be permitted by the hole 32.

The fixing means 41 includes an engaging portion 34 projecting from the elastic portion 33 of the lens pressing ring 3 in the outer diameter direction, and an engaging portion of the lens barrel 2 to which the engaging portion 34 is engaged. Since the hole 22c is provided, the lens retaining ring 3 can be securely fixed in the lens barrel 2 by engaging and disengaging the engaging portion 34 and the engaging hole 22c by elastic displacement of the elastic portion 33 in the radial direction. It can be easily removed together with.

Next, FIG. 5 shows a second embodiment, and FIG. 5 is a sectional view of a lens holding device.

In the first embodiment, the fixing means 41 for fixing the lens press ring 3 and the lens press ring holding section 22 is an engaging section.
As shown in FIG. 5, the projection 51 is formed from the side wall surface 22b of the lens barrel 2 and engages with the elastic portion 33 of the lens holding ring 3 as shown in FIG. With this configuration, the same operation and effect as those of the first embodiment can be obtained.

That is, the upper inclined surface 51a of the projection 51 performs the function of the surface 34r of the engaging portion 34, and the lower inclined surface 51b performs the function of the surface 34f of the engaging portion 34. Become.

In each of the above embodiments, the elastic portion
The elastic force of 33 depends on the angles of the surfaces 34f and 34r of the engaging portion 34 or the angles of the inclined surfaces 51a and 51b of the projection 51, and the hole of the lens holding ring 3.
Since it is relatively determined by the size of the lens 32, the material of the lens holding ring 3, and the like, the angles of the surfaces 34f and 34r of the engagement portion 34 or the protrusion 51
The angles of the inclined surfaces 51a and 51b are also relatively determined.

[0062]

According to the lens holding device of the present invention, when the lens holding ring is inserted into the lens barrel, the diameter of the lens holding ring is set by the fixing means at the position for holding the lens in the lens barrel. Since the lens is fixed to the lens barrel via an elastic portion that can be elastically displaced in the direction, the lens in the lens barrel can be securely held, and the lens can be detached even after holding the lens. The restriction on downsizing of the lens barrel can also be reduced. In addition, since the lens holding ring can be formed with a resin material, it is necessary to make the lens holding ring black, for example, to prevent light leakage. However, using a black resin material can save the trouble of performing black coating. .

According to the lens holding device of the second aspect,
In addition to the effect of the lens holding device according to the first aspect, since a hole is formed along the circumferential direction on the inner diameter side of the elastic portion of the lens holding ring, the hole allows the elastic displacement of the elastic portion in the radial direction. it can.

According to the lens holding device of the third aspect,
In addition to the effects of the lens holding device according to claim 1 or 2, the fixing means includes an engaging portion projecting from the elastic portion of the lens pressing ring in an outer radial direction, and a lens to which the engaging portion is engaged. With the engagement hole of the lens barrel, the engagement between the engagement portion and the engagement hole by the elastic displacement of the elastic portion in the radial direction allows the lens holding ring to be securely fixed in the lens barrel. Can be easily removed.

According to the lens holding device of the fourth aspect,
In addition to the effects of the lens holding device according to claim 1 or 2, the fixing means has a projection projecting from the inside of the lens barrel and engaging with the elastic portion of the lens holding ring. By attaching and detaching the elastic portion and the projection by elastic displacement of the portion in the radial direction, the lens holding ring can be securely fixed in the lens barrel and can be easily removed.

[Brief description of the drawings]

FIG. 1 is a sectional view of a lens holding device according to a first embodiment of the present invention.

FIG. 2 is an enlarged sectional view of a part of the lens holding device.

FIG. 3 is a plan view of the same lens press ring.

FIG. 4 is a cross-sectional view of the lens press ring according to the first embodiment.

FIG. 5 is a cross-sectional view of a lens holding device according to a second embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Lens 2 Lens barrel 3 Lens press ring 21 Lens holding part 22c Engagement hole 32 Hole 33 Elastic part 34 Engagement part 41 Fixing means 51 Projection

Claims (4)

[Claims] 1. A lens barrel having a lens holding portion for holding a lens inside, and an elastic portion capable of being elastically displaced in a radial direction, and being inserted into the lens barrel and between the lens holding portion. A lens holding ring made of a resin for holding the lens with the lens, and fixing means for fixing the lens holding ring at the lens holding position in the lens barrel via the elastic portion. Holding device. 2. A lens holding ring having a hole formed on the inner diameter side of the elastic portion along the circumferential direction to allow elastic displacement of the elastic portion in the radial direction. 2. The lens holding device according to 1. 3. The fixing means has an engaging portion projecting from the elastic portion of the lens press ring in the outer diameter direction, and an engaging hole of the lens barrel with which the engaging portion is engaged. The lens holding device according to claim 1 or 2, wherein: 4. The lens holding device according to claim 1, wherein the fixing means has a projection projecting from the inside of the lens barrel and engaging with an elastic portion of the lens holding ring. apparatus.