JP2000098206A - Lens frame - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lens frame by which the miniaturization and the reduction of weight of a camera or the like are made possible. SOLUTION: This lens frame is constituted of a third group frame 23 which is a thin frame member and whose rigidity is insufficient by itself, lenses 43a and 43b stuck and fixed to a frame and guide shafts 24 and 25. The lenses 43a and 43b are respectively centered and fitted in lens aperture parts 23a and 23b, and are stuck and fixed at the third group frame 23. Also, the guide shafts 24 and 25 are inserted into shaft holes 23c and 23d, and are stuck and fixed by centering with the lens. The lenses 43a and 43b are stuck and fixed, so that the third group frame 23 is provided with sufficient rigidity.

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 frame comprising a lens and a frame member for holding the lens.

[0002]

2. Description of the Related Art Conventionally, Japanese Utility Model Laid-Open Publication No. 59-68306 and Japanese Utility Model Laid-Open Publication No.
The structure disclosed in the above publication has a structure in which a lens frame for holding a lens has sufficient rigidity even without a lens.

On the other hand, in recent years, there has been an increasing need for compact optical devices such as cameras, and the size of lens barrels has been inevitably reduced in order to meet the demand.

[0004]

In the lens frame disclosed in each of the above publications, since the lens frame itself has high rigidity, it is natural that the thickness of the portion of the lens frame holding the lens is held. It is formed thick. Therefore, the lens frame needs to have an occupied space for the thickness of the lens frame, which hinders downsizing or weight reduction of the camera.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems, and has as its object to provide a lens barrel capable of reducing the size or weight of a camera or the like.

[0006]

According to a first aspect of the present invention, there is provided a lens frame including a thin frame member having insufficient rigidity by itself and a lens fitted to the frame member. The required rigidity can be obtained by fixing the frame member and the lens to each other.

A lens barrel according to a second aspect of the present invention is a lens and a thin member which is insufficient in rigidity by itself.
A frame member having a bonding gap for fitting and bonding with the lens is provided, and required rigidity can be obtained by bonding and fixing the frame member and the lens.

According to a third aspect of the present invention, there is provided a lens frame including a thin frame member having insufficient rigidity by itself and a lens fitted to the frame member. The required rigidity is obtained by bonding and fixing.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a longitudinal sectional view of a lens barrel 50 in which a lens barrel according to an embodiment of the present invention is incorporated, in a photographable state, in which an upper half is in a wide state and a lower half is in a tele state. Is shown. Note that the lens barrel 50 is
It is a lens barrel that can be retracted, and all the movable lens frames are moved from the state shown in FIG.

The lens barrel 50 includes a collapsible drive system for driving the collapsible position from the collapsible position to the photographing preparation position, ie, a retractable drive area, a lens group drive system for extending the lens group frame, and a lens group drive system. And a lens group frame portion for holding.

The retractable drive system is mainly fixedly supported by the camera body 51 and advances and retreats between a fixed frame 1 having a helicoid drive gear (not shown) and a drive ring 3 and a retracted position and a photographing preparation position. A rotating frame 2 that rotates between a wide position and a telephoto position at a shooting preparation position, a helicoid ring 4 that is rotatably supported by a moving frame 5 described below, and a position between the retracted position and the photographable position together with the rotating frame 2. A moving frame 5 that moves straight along the optical axis O.

The above-mentioned lens group driving system is mainly inserted into the moving frame 5 and driven to move forward and backward. The cam frame M11 rotates together with the rotary frame 2, and rotates together with the cam frame M11. A cam frame F12 to be driven, a key ring 13 for guiding the lens group in a straight line, and a cam frame M11
The movable flare stop 15 moves straight.

The above-mentioned lens group frame portion is built in the cam frame M11 and the cam frame F12, and is constituted by each lens group holding frame that moves linearly. That is, the first group frame 21 that is driven forward and backward through the cam frame F12 and holds the first lens group 41, and the second group frame 22 that is linearly guided through the key ring 13 and driven forward and backward by the cam frame M11. , Cam frame F
A movable follower 28 that is driven forward and backward through the movable lens 12, a third lens group frame 23 that is driven forward and backward through the movable follower 28 and holds a third lens group 43,
And a focusing frame 29 which is a lens frame that is linearly driven along the optical axis O by a focusing drive system (not shown).

FIG. 2 is an exploded perspective view of the second group frame 22, the third group frame 23, and the movable follower 28. In the second group frame 22,
Three cam followers 32 and 33 are provided on the outer peripheral portion, and three protrusions 22b are provided at the distal end thereof. On the inner circumference,
Straight guide hole 22 into which the straight key of key ring 13 fits
c, a shaft hole 22d along the optical axis O direction, a notch 22e
And a guide shaft 27 fixedly supported along the optical axis O direction.
And an opening 22a in which the shutter 44 is mounted.

The movable follower 28 is a member for regulating the advance / retreat position of the third group frame 23. The movable follower 28 includes a shaft hole 28a into which the guide shaft 27 of the second group frame 22 is slidably fitted, and a cam follower 28b.
And a locking claw 28 c for locking the third group frame 23.

The third group frame 23 is a member that is slidably supported in the straight traveling direction by the second group frame 22. The third group frame 23 includes guide shafts 24 and 25 and two lenses 43a and 43b (see FIG. 3) is attached.

The structure of the third group frame 23 will be described in more detail. FIG. 3 is a longitudinal sectional view of the third group frame 23.
FIG. 4 is a view taken in the direction of the arrow A in FIG. The third group frame 23 is a frame member having a small thickness around the lens opening and not having sufficient rigidity itself. And the lens 43a
A lens opening 23a into which is fitted (precision fitting) without any gap,
A lens opening 23b into which the lens 43b is inserted (with loose fit) with a gap, and shaft holes 23c, 23d into which the guide shafts 24, 25 are inserted (with loose fit) with a gap.
23g between the movable follower and the locking claw 28c
(See FIG. 2).

When each lens is fixed to the third group frame 23, first, as shown in an exploded perspective view of FIG. 5, a lens 43a is fitted into the opening 23a without any gap, and is fixed by bonding. Subsequently, as shown in the exploded perspective view of FIG.
The third group frame 23 to which a is fixed is inverted, and is mounted on a centering jig (not shown).

Then, the lens 43b is inserted into the opening 23b with a gap, and the position is adjusted within the range of the gap so that the optical center of the lens 43b matches the optical center of the lens 43a. In the centered state, an ultraviolet-curable adhesive is injected into the gap and fixed by adhesion. The third group frame 23 in the lens fixed state has a sufficient rigidity to be used as a lens frame member.

Next, when the guide shafts 24 and 25 are fixed to the third group frame 23, they are bonded and fixed using a centering jig 61 as shown in an exploded perspective view of the jig mounted state of the third group frame in FIG. I do.
That is, the guide shafts 24 and 25 are inserted into the shaft holes 61c and 61d of the centering jig 61 without any gap. The third group frame 23 to which the lenses 43a and 43b are fixed is mounted on the centering jig 61 with the lens 43a side facing the jig side.
At this time, the frame outer peripheral portion 23f holding the lens 43a is inserted into the reference hole 61a of the jig 61 without any gap, and the frame outer peripheral end face is brought into contact with the jig axial direction reference surface 61b. At the same time, the guide shafts 24 and 25 are inserted in the shaft holes 23c and 23d of the third group frame in a state where there are gaps, respectively.

When the jig is mounted, the lenses 43a, 43a,
The guide shafts 24 and 25 are held with a predetermined accuracy with respect to the optical core 43b. In this state, an ultraviolet curable adhesive is injected from the injection hole 23e in the shaft hole of the third group frame 23, and is fixed. The guide shafts 24, 25 are provided with cutouts 24a, 25a at the bonded portions for preventing displacement.

In the lens barrel 50 configured as described above, the rotating frame 2, the moving frame 5, and the lens frame supported by them are rotated by the rotation of the helicoid ring 4 supported by the moving frame 5. It is fed out from the retracted position to the shooting position. Further, the drive ring 3 and the rotating frame 2 are connected with each other when the camera reaches the photographing position.

In the photographing state, the rotary frame 2 is rotationally driven by the drive ring 3 to rotate the cam frame M11 and the cam frame F1.
2, the first group frame 21, the second group frame 2, which is each lens frame.
The second and third group frames 23 are driven forward and backward to respective zoom positions.

In the above-described lens barrel 50 incorporating the lens barrel of the present embodiment, the third group frame 23 has a small thickness around the lens opening, and has sufficient rigidity itself. There is no frame member. For example, the wall portion of the frame member is very thin, and when the frame member itself is held in a hand before bonding and fixing the lens, the wall member is easily deformed with a visibly small force. In another example, in the case of a frame member having a guide shaft as in the present invention, the optical axis of the optical element to be incorporated and the central axis of the guide shaft unless the adhesive is fixed by a jig (tool). Are non-parallel.

However, the lenses 43a and 43b have sufficient rigidity to be incorporated in the lens barrel as the third group frame 23 by adhesively fixing them. Therefore, the external shape of the third group frame 23 can be reduced to a small size, and a remarkable effect is produced in making the lens barrel or the camera compact and lightweight. In addition, there is an effect that the degree of freedom is increased with respect to the arrangement of other members around the third group frame 23.

[0026]

As described above, according to the lens barrel of the present invention, a frame member exhibiting rigidity that can be used for the first time is applied by fixing the lens. And the size and weight of a camera or a lens barrel to which the present lens barrel is applied can be realized.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a lens barrel incorporating a lens barrel according to an embodiment of the present invention, in which an upper half shows a shooting preparation state and a wide state, and a lower half shows a telephoto state. .

FIG. 2 is an exploded perspective view around a third lens group frame, which is the lens barrel of the embodiment.

FIG. 3 is a vertical sectional view of a third group frame shown in FIG. 2;

FIG. 4 is a view taken in the direction of the arrow A in FIG. 3;

FIG. 5 is an exploded perspective view showing a state where the lens is fixedly bonded to the third group frame in FIG. 2;

FIG. 6 is an exploded perspective view in a state where another lens is adhered and fixed to the third group frame in FIG. 2;

FIG. 7 is an exploded perspective view in a jig mounted state when the guide shaft is bonded and fixed to the third group frame in FIG. 2;

[Explanation of symbols]

 23 3 group frame (frame member) 43a, 43b lens

Claims (3)

[Claims] 1. A simple frame member having insufficient rigidity by itself and a lens fitted to the frame member, and required rigidity is obtained by fixing the frame member and the lens to each other. A lens frame. 2. A lens comprising: a lens; and a frame member, which is a thin member having insufficient rigidity by itself and having a bonding gap for fitting and bonding to the lens. A lens barrel characterized in that required rigidity is obtained by bonding and fixing a lens. 3. A frame member having insufficient rigidity by itself and a lens fitted to the frame member, and the required rigidity is obtained by bonding and fixing the frame member and the lens. A lens frame characterized in that it can be used.