JPH0784168A - Lens barrel - Google Patents

Abstract

PURPOSE:To prevent a light beam out of a photographing luminous flux from an aperture part from passing and to prevent flare or ghost from being caused on the result of photographing by providing a light shielding member covering the aperture part interlocked with the moving action of a member retreated from the aperture part in a lens barrel where two members relatively moving in an optical axis direction are electrically connected through a flexible wiring board. CONSTITUTION:A light shielding member 22 which can be turned centering around a shaft 21a is attached at a position for opening/closing the aperture part 2c formed at the flange part 2b of a fixed barrel 2 on a 2nd lens frame 21. A torsion coil 23 energizing the member 22 in a direction where the aperture part 2c is covered and a direction where the folded part 10a of the wiring board 10 is retreated from the aperture part 2c is attached to the shaft 21a. In a state where the 1st folded part 10a is retreated from the aperture part 2c interlocked with the movement of the wiring board 10 in an optical axis direction, the member 22 covers the aperture part 2c so as to prevent the light beam out of the photographing luminous flux from passing.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lens barrel for electrically connecting two members relatively moving in the optical axis direction with a flexible wiring board.

[0002]

2. Description of the Related Art FIGS. 5 and 6 are cross-sectional views of a main part showing the structure of a conventional lens barrel. FIG. 5 shows a first state diagram in a zooming operation, and FIG. 6 shows a second state diagram. ing. In the figure, 1 is a claw portion 1 for connecting to a camera body (not shown).
A mount 2 having a is a fixed cylinder as a first member having a cylindrical shape connected to the mount 1, and has a guide groove 2a parallel to the optical axis and a flange portion 2b on the inner wall surface.
have. Reference numeral 3 is a cam barrel that is rotatably fitted to the fixed barrel 2 and has a cam groove 3a.

Reference numeral 4 denotes a first lens frame which holds the lens group L1 and the electric diaphragm device 5, and rollers 6 which engage with the guide groove 2a of the fixed barrel 2 and the cam groove 3a of the cam barrel 3 respectively. It is provided on the outer diameter portion. A second lens frame 7 holds the lens unit L2 and is attached to the flange portion 2b of the fixed barrel 2.

Reference numeral 8 denotes a contact member that serves as an electrical contact with the camera body, and is attached to the mount 1 and connected to an annular disk-shaped circuit board 9 on which electric parts are mounted and which forms an electric circuit. . Reference numeral 10 denotes a flexible wiring board, one end of which is connected to the connector 11 on the circuit board 9 and the other end of which is connected to the terminal of the electric diaphragm device 5 held by the first lens frame 4. . The intermediate portion is 18 at each of the first folded portion 10a and the second folded portion 10b.
It is folded back at 0 ° and is wired through the opening 2c provided in the flange portion 2b of the fixed barrel 2.

In this case, the second portion facing the opening 2c
The flange portion 7a of the lens frame 7 is omitted. 12
Is a holding plate whose one end is attached to the first lens frame 4 and extends in the optical axis direction along the wiring board 10, and the other end is fixed by sandwiching the first folded portion 10a of the wiring board 10. There is. Reference numeral 13 is a back cover which is fixed to the mount and has a cylindrical portion extending in the optical axis direction.

In the above structure, the first lens frame 4, the lens unit L1, the electric diaphragm device 5, and the holding plate 12 are restricted to be movable only in the optical axis direction by the relationship between the roller 6 and the guide groove 2a of the fixed barrel 2. Therefore, when the cam barrel 3 is rotated around the optical axis by a zooming unit (not shown), the cam barrel 3 is moved between the first state shown in FIG. 5 and the second state shown in FIG. 6 along the locus of the cam groove 3a. To move continuously.

At this time, the wiring board 10 has the first folded portion 1
0a penetrates through the opening 2c of the fixed barrel 2 and moves back and forth to move in the same direction as the first lens frame 4, and the second folded portion 10b moves in the same direction by half the amount of the first lens frame 4. ,
It absorbs a relative position change between the electric diaphragm device 5 and the circuit board 9, and sends a drive signal to the electric diaphragm device 5 based on a signal from the camera body sent through the contact member 8 in any state. Is able to.

[0008]

However, in the above-mentioned conventional example, in the second state shown in FIG. 6, the first folded-back portion 10a of the wiring board 10 has the opening 2c of the fixed barrel 2.
Since it is in a more retracted state, the light rays outside the photographing light flux pass through the opening 2c and are reflected by the inner surface of the fixed barrel 2 and reach the photographing surface, resulting in ghost and flare in the photographing result. However, there was a problem that it had a negative impact.

An object of the present invention is to obtain a lens barrel that solves the above problems.

[0010]

According to the present invention, the second member is held so as to be movable in the optical axis direction relative to the first member.
Lens barrel having a member and a flexible wiring board that has at least one folded-back portion that absorbs a change in relative position between the first member and the second member and electrically connects the two members to each other. In the third member, the first member or the third member held integrally with the first member or relatively movable in the optical axis direction.
By providing an opening provided on at least one of the members for advancing and retracting the folded-back portion and a light-shielding member for covering the opening in conjunction with a moving operation of retracting the folded-back portion from the opening, It prevents light rays outside the shooting light beam from passing through the aperture, and moves relative to the shooting result without adverse optical effects such as flare and ghost.
It is possible to provide a lens barrel in which members are electrically connected.

[0011]

【Example】

Example 1. Embodiments of the present invention will be described below with reference to the drawings. 1 and 2 are cross-sectional views of a main part of a first embodiment of the present invention. The same parts as those of the conventional example shown in FIGS. 5 and 6 are designated by the same reference numerals and duplicate description will be omitted.

Reference numeral 21 denotes a second lens frame as a third member which holds the lens unit L2 and is attached to the flange portion 2b of the fixed barrel 2. The second lens frame 21 is provided with a light blocking member 22 which is rotatable about a shaft 21a at a position where the opening 2c formed in the flange 2b of the fixed barrel 2 is opened and closed. Further, the shaft 21a is provided with the light shielding member 22 in a direction to cover the opening 2c and in the wiring board 1.
A torsion coil spring 23 that biases the 0-folded portion 10a in the direction of retracting from the opening 2c is attached.

The light shielding member 22 and the torsion coil spring 23
In the state in which is assembled to the second lens frame 21, the light shielding member 22 is configured to be in contact with a stopper portion 21b integrally provided in the second lens frame 21,
After assembling in this state, it is fixed to the flange portion 2b of the fixed barrel 2 from the rear of the lens.

In the above-described structure, in the first state shown in FIG. 1, the light shielding member 22 holds the first coiled portion 10a of the wiring board 10 by the holding plate 11 which is fixed to the torsion coil spring 23. In the second state shown in FIG. 2, the light shielding member 22 is twisted by the torsion coil spring 23 against the biasing force and is rotated to a position retracted from the opening 2c.
The position where it comes into contact with the stopper portion 21b by the urging force of
That is, it is biased to a position that covers the opening 2c.

That is, in the first embodiment, the first wiring board 10
In a state in which the first folded-back portion 10a is retracted from the opening 2c in conjunction with the position of the folded-back portion 10a in the optical axis direction, the light shielding member 22 covers the opening 2c and prevents passage of light rays outside the photographing light flux. .

Example 2. 3 and 4 are cross-sectional views of the essential parts showing the configuration of a second embodiment of the present invention. Like the first embodiment, the same parts as those of the conventional example shown in FIGS. And repeated description is omitted.

Reference numeral 31 is a flexible light-shielding member which is provided with a folded-back portion 31a of 180 ° and whose both ends are attached to the second lens frame 7 and the holding plate 11, respectively. With this configuration, when the first lens frame 4 moves in the optical axis direction from the first state shown in FIG. 3 to the second state shown in FIG. 4, the folding portion 31a moves in the first direction in conjunction with the movement. Lens frame 4
Of the light shielding member 31
Together with the holding plate 11 penetrates through the opening 2c provided in the fixed barrel 2 and extends toward the front of the lens to prevent light rays outside the photographing light flux from entering and passing through the opening 2c.

Although the second lens frame 7 is fixed in each of the first and second embodiments, it does not have to be fixed in particular, and it does not substantially change even if it is movably held.

[0019]

As described above, according to the present invention,
At least one folded portion that electrically connects the first member and the second member and absorbs a change in the relative position of the first member and the second member is integrated with the first member or in the optical axis direction. Since a light-shielding member that covers the opening is provided in conjunction with the moving operation of retracting from the opening provided in at least one of the third members held movably relative to It is possible to obtain a lens barrel in which two members that move relative to each other are electrically connected to each other by preventing passage of light rays outside the light flux, and without adversely affecting the photographing result optically such as flare and ghost.

[Brief description of drawings]

FIG. 1 is a sectional view of an essential part of a lens barrel in a first state showing a first embodiment of the present invention.

FIG. 2 is a sectional view of the second state essential part of the first embodiment.

FIG. 3 is a cross-sectional view of an essential part of a lens barrel in a second state showing Embodiment 2 of the present invention.

FIG. 4 is a cross-sectional view of an essential part of a second state of the second embodiment.

FIG. 5 is a cross-sectional view of a main part of a conventional lens barrel in a first state.

FIG. 6 is a sectional view of an essential part showing the second state thereof.

[Explanation of symbols]

 2 Fixed Tube (First Member) 4 First Lens Frame (Second Member) 10 Wiring Board 12 Holding Plate 21 Second Lens Frame (Third Member) 22 Light-Shielding Member 23 Torsional Coil Spring (Biasing Member) 31 Light-shielding member

Claims (3)

[Claims] 1. A second member held so as to be movable in the optical axis direction relative to the first member, the first member and the second member.
A lens barrel having a flexible wiring board that has at least one folded-back portion that absorbs a change in relative position of the member and electrically connects both members to each other. An opening for advancing and retracting the folding portion provided on at least one of the third members held integrally with the member or relatively movable in the optical axis direction, and a moving operation for retracting the folding portion from the opening. A lens barrel comprising: a light-shielding member that covers the opening in cooperation with the lens barrel. 2. The lens barrel according to claim 1, wherein the light shielding member is biased by a biasing member in a direction to cover the opening. 3. The light shielding member is a flexible member arranged so as to absorb a relative position change in the optical axis direction with respect to the first member or the third member. The lens barrel according to claim 1.