JPH0511159A - Lens fitting structure of optical equipment - Google Patents

Abstract

PURPOSE:To obtain high strength by shaping positioning members for a secondary image forming lens and a holding member so that an adhesive is easy to flow and making the positioning parts serve as adhesion parts. CONSTITUTION:A holder 15 and the secondary image forming lens 12 are positioned by adhering positioning pins 12A and 12B projecting from the secondary image forming lens in positioning holes 15a and 15b of the holder. Namely, the positioning holes 15a and 15b position the positioning pins 12A and 12B in directions A-A' and B-B' respectively; and flow grooves Ca and Cb, and Da and Db for the adhesive are provided in directions other than the positioning directions and positioning in those grooves is performed. Thus, the flow grooves Ca and Cb, and Da and Db for the adhesive are formed at the peripheries of the positioning holes 15a and 15b, so the adhesive stays there and the adhesive strength of the two positioning parts can be improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lens mounting structure for an optical device such as a camera, and more particularly to a mounting structure for a secondary imaging lens in a focus detecting device for a camera.

[0002]

2. Description of the Related Art Conventionally, a focus detection device of a secondary image shift type has a problem that a distance measurement error occurs due to a position shift of a re-imaging lens. For example, if the secondary imaging lens is slightly tilted, the focus surface is tilted, so the distance measurement result will naturally differ depending on where in the distance measurement field the subject exists. .. Further, when the secondary imaging lens is aligned, the axes of the sensor and the secondary imaging light are deviated, and the same phenomenon occurs.

Therefore, the holding accuracy of the secondary imaging lens is important.

In the prior art, the positions of the secondary imaging lens and the holding member for maintaining the holding accuracy were determined by the positioning pins and fixed by adhesion. For the adhesive part, the positioning part is used as the adhesive part.

[0005]

However, in the conventional example, since there is no gap for the adhesive to flow into the positioning portion, the bonding strength is weak, the position of the secondary imaging lens moves, the position accuracy is poor, and correct focus detection is not possible. There is a problem that you cannot do it.

FIG. 8 is a view of a mounting surface of a secondary imaging lens of a holder which is a conventional example.

In the figure, 16 is a holder, 16a is a positioning hole having a shape in which the entire circumference of the inner surface is positioned, 16b is a positioning hole for positioning with the secondary imaging lens 12 having a shape that positions in one direction. Is.

In the conventional example, since the positioning hole 16b is positioned in one direction, there is a gap in the direction perpendicular to the positioning direction, which serves as an adhesive flow groove. Since the positioning is performed, there is no gap, the penetration of the adhesive is poor, the adhesive strength is weak, and the secondary imaging lens may move.

SUMMARY OF THE INVENTION An object of the present invention is to solve the problems in the conventional mounting structure and to provide an improved lens mounting structure capable of firmly mounting a lens.

[0010]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems. The positioning portion between the secondary imaging lens and the holding member is shaped so that the adhesive can flow into it, and the positioning portion also includes the bonding portion. The present invention also provides a focus detection device that holds the secondary imaging lens with high adhesive strength.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below based on the illustrated embodiments.

FIG. 4 is a view showing the schematic arrangement of a focus detection apparatus according to an embodiment of the present invention.

In the figure, 7 is a visual field mask having a cross opening. 8 is an infrared cut filter, 9 is a feed lens, 11 is a diaphragm having apertures 11a to 11d, 1
Reference numeral 2 denotes a secondary imaging lens having four lenses 12a to 12d corresponding to the respective openings 11a to 11d of the diaphragm 11, and 13 photoelectrically converts a secondary image of an object formed by the secondary imaging lenses 12a to 12d. Is a light receiving sensor for.

FIG. 5 is a diagram showing a concrete structure of a focus detection unit in which the focus detection optical system as shown in FIG. 4 is compactly housed.

In the figure, 7 is a field mask, 8 is an infrared cut filter, 9 is a field lens, 10 is a total reflection mirror,
Reference numeral 11 is a diaphragm, 12 is a secondary imaging lens, 13 is a light receiving sensor, and 14 is a plate for shielding light and dust. These components are held by the holder 15, which
Is fixed to a camera body (not shown).

FIG. 3 is a cross-sectional view of the coupling portion between the secondary imaging lens 12 and the holder 15.

In the figure, 12A and 12B are positioning pins for positioning and adhering to the holder.

FIG. 1 is a view of the mounting surface of the secondary imaging lens of the holder.

In the figure, 15a and 15b are positioning holes for positioning and adhering to a secondary imaging lens having a flow groove for the adhesive.

The holder 15 and the secondary imaging lens 12 are positioned by the positioning pins 12A, 1 protruding from the secondary imaging lens.
2B and the positioning holes 15a and 15b of the holder are bonded to perform positioning and bonding.

FIG. 8 is a view of the mounting surface of the secondary imaging lens of the conventional holder.

In the figure, 16 is a holder, 16a is a positioning hole having a shape in which the entire circumference of the inner surface is positioned, 16b is a positioning hole for positioning with the secondary imaging lens 12 having a shape that positions in one direction. Is.

In the conventional example, since the positioning hole 16b is positioned in one direction, there is a gap in the direction perpendicular to the positioning direction, and it functions as a flow groove for the adhesive. Since the positioning is performed, there is no gap, the penetration of the adhesive is poor, and the shape is not suitable for bonding.

FIG. 2 is an enlarged view of the positioning pin and the positioning hole.

In the figure, the positioning holes 15a and 15b are A-
Positioning pin 12 in one direction of each of A'and BB '
Since A and 12B are positioned and adhesive flow grooves Ca, Cb, Ca and Cd are provided in the other direction of the positioning direction, positioning can be performed and high adhesive strength can be provided.

FIGS. 6A to 6C show another embodiment of the positioning hole of the holder.

The holder 17 shown in FIG. 6 (a) has a positioning hole 17a having adhesive flow grooves Ea and Eb and a positioning hole 17b having adhesive flow grooves Fa and Fb. ..

The holder 18 of FIG. 6B has a positioning hole 18a having adhesive flow grooves Ga and Gb and a positioning hole 18b having adhesive flow grooves Ha and Hb. ..

The holder 19 shown in FIG. 6C has a positioning hole 19a having adhesive flow grooves Ia and Ib and a positioning hole 19b having adhesive flow grooves Ja and Jb. ..

FIG. 7 is a sectional view showing a case where the focus detecting apparatus having the optical system according to the above-mentioned embodiment is incorporated in a single lens reflex camera.

In the figure, 20 is a camera body, 21 is a lens barrel that holds a taking lens 22 movably in its optical axis direction, and 23 is a movable half mirror that separates object light into a focus detection system and a finder observation system. , 24 is a penta prism 25
Further, a focus glass forming a finder observation system together with the eyepiece lens 26, and a movable mirror 27 for guiding light to the focus detection unit 28.

Next, the operation of the focus detection device having the above configuration will be described.

First, the light emitted from the object is incident on the taking lens 22 and forms an aerial image on the planned image forming surface. Behind this, a visual field mask 7 is arranged, and the light passing through the cross opening of the visual field mask 7 enters the infrared cut filter 8 where the infrared component is removed. The field lens 9 placed next to the infrared cut filter 8
It is for projecting the diaphragm 11 onto the exit pupil of a photographing lens (not shown), and has a function of bending the light incident on the field mask opening outside the optical axis in the direction of the diaphragm 11. The light fluxes that have passed through the four openings 11a to 11d of the diaphragm 11 enter the respective lenses 12a to 12d of the secondary imaging lens 12 and the respective line sensors 13a to 13d on the light receiving sensor 13.
To form a secondary image of the object.

The relative distances of these secondary images change with defocusing of a taking lens (not shown), and the defocusing amount can be known from this displacement amount.

[0035]

As described above, according to the present invention, in the bonding between the secondary imaging lens and the holding member, the positioning portion is provided with the groove into which the adhesive flows, so that the bonding strength between the two positioning portions is increased. It is possible to improve the position and prevent the secondary imaging lens from being displaced.

[Brief description of drawings]

FIG. 1 is a front view of a first embodiment of a lens mounting structure according to the present invention.

FIG. 2 is an enlarged view showing a positioning pin, a positioning hole, and an adhesive flow groove in the structure shown in FIG.

FIG. 3 is a cross-sectional view of the adhesive between the lens and the holding member in the structure shown in FIGS. 1 and 2.

FIG. 4 is an exploded perspective view of a main part of a focus detection device to which the lens mounting structure shown in FIGS. 1 to 3 is applied.

5 is an exploded perspective view of the entire focus detection device shown in FIG.

6A to 6C are front views of a lens mounting structure according to another embodiment of the present invention.

FIG. 7 is a schematic diagram showing an optical system of a camera equipped with the focus detection device shown in FIGS.

FIG. 8 is a front view showing a lens mounting structure of a conventional focus detection device.

[Explanation of symbols]

7 ... Field mask 8 ... Infrared cut filter 9 ... Field lens 10 ... Total reflection mirror 11 ... Aperture 11a-11d ... Aperture 12 ... Secondary imaging lens 13 ... Light receiving sensor 15-19 ... Holder 15a, 15b, 16, 16b , 17a, 17b, 18
a, 18b, 19a, 19b ... Positioning hole 12A, 12B ... Positioning pin

Claims (1)

Claim: What is claimed is: 1. A lens mounting structure for an optical device, wherein a lens is positioned with respect to a holding member by a positioning hole and is fixed to the holding member by an adhesive. It is characterized in that an adhesive flow groove into which an adhesive enters is provided around the positioning hole for positioning the lens on the holding member. Lens mounting structure for optical equipment.