JPH08240757A - Lens fixing device - Google Patents

Abstract

PURPOSE: To at high accuracy perform the fixing of plural sheets of lenses even with flat sheet member as sheet member to be interposed in between to be assembled and fixed in an fixing device in which lenses being >=2 sheets to be assembled and fixed simultaneously in the lens barrel while being butted each other. CONSTITUTION: In a lens fixing device in which lenses L1, L2 being >=2 sheets are assembled and fixed simultaneously while being butted each other, a sheet member 1 to be interposed in between lenses to be assembled and fixed has notched parts 30 being >=1 notch in an outside diameter and the diameter 31 of the inner sides of the notches is made to be the side outer than the butting diameter of lenses to be butted each other.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lens fixing device and an optical apparatus for assembling and fixing two or more lenses at the same time by abutting lens surfaces against each other.

[0002]

2. Description of the Related Art Conventionally, when a plurality of lenses are assembled and fixed in a lens barrel, it is difficult to fix the lenses one by one if the air gap between adjacent lenses is small. for that reason,
As shown in FIG. 6, a lens fixing method is known in which two or more lenses 101 and 102 are attached to a lens barrel 104 at the same time by abutting lens surfaces on the outside of the effective diameter of the lens (hereinafter , Such a fixing method is called marginal contact).

When assembling and fixing the lens to the lens barrel 104 with this marginal contact, to block harmful light coming from outside the effective diameter, reduce friction at the time of abutting, alleviate stress concentration, etc. A sheet member (hereinafter referred to as marginal washer) 103 as shown in FIG. 7 is interposed between the lenses 101 and 102 in contact with each other. In addition,
In FIG. 6, 105 is a filter frame, 106 is a focus key, 107 is an AF driving actuator, 1
08 is a manual ring.

[0004]

However, in the above-described conventional example, the marginal washer 103 has a problem with a sheet formed by a plane (manufactured by punching out vinyl chloride etc.) when the lens 102 on the receiving side has a large curvature. You can fix the lens without. However, the receiving lens 102
When the curvature of the lens is small, or when the diameter difference between the abutting diameter and the outer diameter is large due to the constraint of the lens barrel as shown in FIG. 7, the marginal washer 103 does not deform along the spherical surface of the lens 102, and the lens There is a problem that it is difficult to insert the marginal washer because wrinkles or breakage may occur in the vicinity of the butting diameter 109.

When the marginal washer is inserted and the lens is caulked and fixed, the elasticity of the marginal washer causes the lens 101 on the abutting side to rise and the lens cannot be properly fixed.

In order to solve this problem, the planar marginal washer must be drawn into a shape close to the spherical surface of the lens 102 as shown in FIG. 8, which increases the number of processing steps and increases the cost. There was another problem that it ended up.

The object of the invention according to claim 1 of the present application is to perform a drawing process even when the curvature of the lens on the receiving side is small, or when the diameter difference between the abutting diameter and the outer diameter is large due to the restriction of the lens barrel. That is, the lens can be mounted and fixed with the flat sheet member as it is without adding.

An object of the invention according to claim 2 of the present application is to provide a masking effect to the opening for cutting harmful light.

An object of the invention according to claim 3 of the present application is to further enhance the effect of removing flare and ghost when cutting harmful light.

An object of the invention according to claim 4 of the present application is to facilitate the positioning by allowing the sheet member to be uniquely arranged.

An object of the invention according to claim 5 of the present application is to make the fixing of the lens of the optical device highly accurate.

[0012]

In order to achieve the above object, in the invention according to claim 1 of the present application, two or more lenses are simultaneously assembled and fixed in a lens barrel by abutting lens surfaces with each other. In the lens fixing device, the sheet member interposed between the assembled and fixed lenses has one or more notches on the outer diameter, and the inner diameter of the notch is larger than the abutting diameter of the lenses. By setting the outer side, it is possible to prevent the sheet member from wrinkling and to weaken the force generated in the direction of expanding the lens interval.

In the invention according to claim 2 of the present application, harmful light can be cut and flare and ghost can be removed by making the opening diameter of the sheet member substantially equal to the effective diameter of the lens barrel.

In the invention according to claim 3 of the present application, the opening of the sheet member is rectangular, or a combination of the rectangle and the circle is formed into a rotationally asymmetric shape with respect to the optical axis, so that the light enters the area other than the screen range. It can cut harmful light and remove flare and ghost.

In the invention according to claim 4 of the present application, since the sheet member is provided with the rotation positioning means, the opening can be uniquely arranged so as to have a shape substantially similar to the screen, and the sheet can be easily assembled. .

According to the invention described in claim 5 of the present application, by applying the lens fixing device according to claim 1, the lens can be assembled and fixed in an optical device with high accuracy.

[0017]

【Example】

First embodiment. Hereinafter, the present invention will be described in detail based on embodiments shown in the drawings. FIG. 1 is a longitudinal sectional view of a monofocal lens barrel for a single-lens reflex camera showing a first embodiment to which a lens fixing device according to the present invention is applied, and FIG. 2 is an enlarged detailed view of a portion A of FIG. . 1 and 2, L1 is a concave lens,
L2 represents a convex lens, and L3 to L5 represent lens groups, respectively. The first lens group of L1 and L2 is a fixed group, and L3 to L5.
Is a focusing lens group that moves to the object side as a whole when the focus is adjusted from infinity to the closest distance.

1 is a marginal washer as a sheet member sandwiched between the first lens groups L1 and L2 by marginal contact, 2 is a first lens barrel for fixing the first lens groups L1 and L2, and 3 is a filter frame. In addition, a screw portion 3a is provided at the tip so that a filter can be attached, and a bayonet 3b is provided at the outside so that a hood (not shown) can be attached.

Reference numeral 5 represents an AF driving actuator, and rotation of the focus key 4 about the optical axis is represented as an output of the actuator 5. Reference numeral 7 is a manual ring having a structure in which the focus key 4 can also be rotated. The actuator 5 is, for example, Japanese Patent Application Laid-Open No. 2-25.
Since it is known as disclosed in Japanese Patent No. 3214, detailed description of its structure is omitted.

Reference numeral 6 denotes a focus screw fixed to the rear lens barrel 18, which rotates the rear lens barrel 18 via the focus key 4 by the rotational force of the actuator 5. Lens groups L4 and L5 are fixed to the rear group lens barrel 18.

Reference numeral 8 is a guide tube fitted to the outer side of the rear group lens barrel 18, and three circumferentially formed cam grooves are equally formed in its circumferential direction.
The roller 1 fixed to the rear lens barrel 18 in the cam groove 8a
1 is fitted. 16 is a lens holding the second lens group L3
It is a group barrel. Therefore, with the actuator 5 or the manual ring 7, the focus key 4 and the focus screw 6
When the rear lens barrel 18 is rotated via the
8 moves the cam groove 8a in the optical axis direction by the roller 11,
With this movement, the second group lens barrel 16 also integrally moves in the same direction. Reference numeral 17 denotes an electromagnetic diaphragm fixed to the rear lens barrel 18.

Reference numeral 12 denotes a fixed cylinder provided with a distance window 9, through which the distance scale 10 inside can be seen. Reference numeral 13 denotes a mounting board on which a microcomputer and electric elements for controlling the driving of the lens and communicating with the camera body 23 are mounted. Reference numeral 14 is a mount for bayonet coupling with the camera body 23, 15 is a back cover, and 20 is a contact block. The contact block 20 comes into contact with the electrical contacts of the camera body 23. Is electrically connected to.

FIG. 3 is a front view of a single unit of the above-mentioned marginal washer 1 as seen from the optical axis direction. As can be seen from comparison with the conventional example shown in FIG. 7, a plurality of notches 30 are provided. 6 in the example). The inside diameter 31 of the notch 30 is outside the abutting diameter 34, and the lens does not fall. Diameter 32 other than notch
Fits with the positioning diameter 21 of the first group lens barrel 2 so that the marginal washer 1 is not displaced.

The opening 33 of this marginal washer 1
Is substantially the same as the effective diameter of the first group lens L2, so that it is possible to cut off the reflection of harmful light that tends to occur in the vicinity of the abutting diameter 34. Further, since light rays do not enter the outside of the abutting portion, the provision of the cutout 30 does not cause any harm.

When this marginal washer 1 is assembled between the first lens group L1 and the second lens group L2, as shown by the solid line in FIG.
The shape is along the lens in the vicinity of the abutting diameter 34 of the lens, but the outside thereof fits into the positioning diameter 21 and enters. At this time, since the notch 30 is provided, no force is applied in the direction to widen the lens interval even when the notch 30 is incorporated as shown by the dotted line. Further, since the notch 30 absorbs the slack, wrinkles do not occur. Therefore, FIG.
It is also possible to make the shape substantially along the spherical surface as in the above, depending on the curvature of the spherical surface.

Second embodiment. FIG. 5 is a front view of the marginal washer showing the second embodiment. The outer shape of this marginal washer is provided with a plurality of notches 40 as in the first embodiment shown in FIG. 3, where 41 is the inside diameter of the notches 40 and 42 is the diameter other than the notches. The opening 43 is formed by combining a rectangle and a circle, and has a rotationally asymmetric shape with respect to the optical axis. This shape is substantially similar to the screen and positively removes harmful light. Further, both side portions 45 of the notch 40 are adapted to enter into two convex portions (not shown) provided on the first-group barrel 2 so that positioning can be easily performed.

The above-described embodiments can be applied to fixing of lenses in optical equipment such as video lenses other than lenses for single-lens reflex cameras and lenses for projectors.

[0028]

As described above, according to the first aspect of the present invention, the sheet member interposed between the lenses to be assembled and fixed has one or more notches on the outer diameter, and the notches are provided. Since the inner diameter of the sheet is configured to be outside the abutting diameter of the lenses, the sheet member can be used even when the lens curvature on the receiving side is small or when the diameter difference between the abutting diameter and the outer diameter is large due to the constraint of the lens barrel. Wrinkles can be prevented, and the force generated in the direction of expanding the lens interval can be weakened.
As a result, the degree of freedom in design is increased and the drawing process can be abolished, which can contribute to cost reduction.

According to the second aspect of the invention, since the opening diameter of the sheet member is made substantially equal to the effective diameter of the lens barrel, there is an effect that harmful light can be cut and flare and ghost can be removed. .

According to the third aspect of the present invention, since the opening of the sheet member is formed in a rectangular shape or a combination of a rectangle and a circle to have a rotationally asymmetric shape with respect to the optical axis, harmful light entering outside the screen range can be prevented. It has the effect of cutting and removing flare and ghosting.

According to the invention as set forth in claim 4, since the rotational positioning means is provided on the sheet member, it is possible to arrange the opening uniquely so that the opening is substantially similar to the screen, and it is possible to easily assemble. is there.

According to the invention described in claim 5, since the lens fixing device according to claim 1 is applied, there is an effect that the lens can be incorporated and fixed in an optical device with high accuracy.

[Brief description of drawings]

FIG. 1 is a sectional view of a lens barrel showing a first embodiment of the present invention.

FIG. 2 is an enlarged detailed view of part A of FIG.

FIG. 3 is a front view of the marginal washer in the first embodiment as viewed from the optical axis direction.

FIG. 4 is a perspective view of the marginal washer.

FIG. 5 is a front view of the marginal washer showing the second embodiment of the present invention as seen from the optical axis direction.

FIG. 6 is a sectional view of a lens barrel to which a conventional lens fixing device is applied.

FIG. 7 is a front view of a marginal washer used in a conventional device.

FIG. 8 is a perspective view of a marginal washer that has been drawn.

[Explanation of symbols]

 L1, L2 lens 1 marginal washer (sheet member) 2 first group lens barrel (lens barrel) 30, 40 notch 31, 41 inner diameter of notch 33, 43 opening 34 abutting diameter

Claims (5)

[Claims] 1. In a lens fixing device in which two or more lenses are simultaneously assembled and fixed in a lens barrel by abutting lens surfaces to each other, a sheet member interposed between the assembled and fixed lenses has an outer diameter. A lens fixing device having one or more notches, wherein the inside diameter of the notches is outside the abutting diameter of the lenses. 2. The lens fixing device according to claim 1, wherein the opening diameter of the sheet member is substantially equal to the effective diameter of the lens barrel. 3. The lens fixing device according to claim 1, wherein the opening of the sheet member has a rotationally asymmetric shape with respect to an optical axis formed by a rectangle or a combination of a rectangle and a circle. . 4. The lens fixing device according to claim 3, wherein the sheet member has a rotational positioning means. 5. An optical apparatus, wherein the lens fixing device according to claim 1 is applied and the lens is assembled and fixed in a lens barrel.