JP3123723B2 - Barrel light blocking structure of lens shutter camera with built-in zoom lens - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light shielding structure for blocking light from a lens barrel of a lens shutter camera with a built-in zoom lens.

[0002]

2. Description of the Related Art In a conventional zoom lens barrel, a cam barrel 2 is fitted on a fixed barrel 1 as shown in FIG.
The lens barrel block 5 having the pins 3 and 4 engaging with the key groove 1a and the cam groove 2a of the cam barrel 2 is fitted in the fixed barrel 1 so as to advance straight by the rotation of the cam barrel 2. The rubber 10 is fixed to the front cover 6 or a light-blocking member that is dropped into a gap between the front cover 6 and the fixed cylinder 1, for example, a light-blocking member in which a suede 8 is attached to the ring 7 or a rubber 10. Is applied so as to protrude in the inner diameter direction to prevent external light from entering from a gap a between the front cover 6 and the lens barrel block 5.

[0003]

When light is shielded using a highly elastic member such as the rubber 10 or the suede 8 as in the above-described conventional example, light can be shielded in a relatively small space. Alternatively, a light source such as a suede is crushed to shield the light, and the outer wall of the lens barrel block 5 slides on the light to drive the light.

An object of the present invention is to provide a light-shielding structure of a camera with a built-in zoom lens which is suitable for downsizing of a camera without using a light-shielding member such as rubber in view of the above-mentioned problems of the conventional example.

[0005]

Means for Solving the Problems In order to achieve the above-described object, a lens barrel light shielding structure of a lens shutter camera with a built-in zoom lens according to the present invention includes a fixed cylinder having at least three or more female helicoids in an inner diameter portion, a cam cylinder having male helicoid meshing with the female helicoid, the cam cylinder with rotatable holding and rotation of the cam cylinder engaged with the key groove cut into the said fixed tube relative to the fixed tube A lens barrel block that travels straight, a zoom motor that drives the cam barrel via a gear attached to the lens barrel block, an outer cylinder that is attached to the lens barrel block and covers the outside of the fixed barrel, It consists of a barrel cover provided outside, in any of the positions of the linear motion of the lens barrel block with the rotation of the cam barrel, the fixed barrel, the outer cylinder, three lens barrel cover
The fixed barrel, the outer barrel, and the lens barrel cover are overlapped with each other.
Forming a bar, and connecting the cam cylinder and the fixed cylinder with a helicoid
It is a combination .

[0006]

The light-blocking structure of the lens barrel having the above-described structure constitutes an intaglio structure by attaching an outer cylinder to a lens barrel block to cover a fixed cylinder, and providing a lens barrel cover attached to the main body outside the fixed cylinder . Helicoid coupling between the cam cylinder and fixed cylinder
As a result , a compact light shielding structure for preventing external light from entering from the lens barrel is obtained.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIGS. FIG. 1 is a sectional view of the telescopic state of the lens barrel, and FIG.
Is when the retractable lens barrel contains more lenses than in the wide state,
Each is shown. In the drawing, reference numeral 11 denotes a fixed cylinder, which is attached to the main body 12 and its attachment portion is sufficiently shielded from light. The inner diameter of the cylinder is provided with three or four female helicoid screws 11a and a key groove 11b parallel to the optical axis. ing. Reference numeral 13 denotes a cam cylinder, which is rotatable with respect to the base plate 15 by being sandwiched between the upper base plate 14 and the base plate 15, and having a male helicoid screw 13a provided on an outer peripheral portion thereof.
Female helicoid screw 11a. The base plate 15 is provided with a key 15 a that fits into the key groove 11 b of the fixed barrel 11.
Is designed to go straight in the optical axis direction. An inner gear 13b is formed on the inner diameter of the cam cylinder 13, and the inner gear 13b is operatively connected to a zoom motor 17 via a reduction gear 16, and the cam cylinder 13 is rotated by the rotation of the zoom motor 17. It is made to let.

On the other hand, on the upper base plate 14, a base plate 15 is screwed on one end surface and an AF base plate 18 is screwed on the other end surface, and a shutter unit (not shown) is provided between the base plate 15 and the AF base plate 18. Is stored. AF ground plane 18
An AF mechanism (not shown) including an AF motor and a first
The front group holder 20 that holds the group lens L1 is housed. 21 is a guide bar for holding the front group holder 20 movably in the optical axis direction. An outer cylinder 22 is provided outside the fixed cylinder 11 and always has an overlapping portion 22a with the fixed cylinder 11. Further, the outer cylinder 22 is connected to the upper ground plate 1 together with the AF ground plate 18.
The screw 4 is used to screw the cam cylinder 13 so that the cam cylinder 13 moves straight with respect to the fixed cylinder 11. A lens barrier 23 is provided between the outer cylinder 22 and the barrier cover 24. With this arrangement, the space used by the lens barrier mechanism is larger than the diameter of the fixed barrel 11 and can be stored more easily than the arrangement in the barrel block 5 shown in FIG. It is configured to be easily adaptable to a lens having a large L1 or a wide-angle lens. Also,
A lens barrel cover 25 fixed to the main body is provided outside the outer cylinder 22, and the lens barrel cover 25 has an overlapping portion 25 a with the outer cylinder 22 regardless of the position of the outer cylinder 22. Thus, the overlapping portion 22a of the outer cylinder 22 and the lens barrel cover 25
The light reaches the film F through a small gap between the fixed cylinder 11 and the cam cylinder 13 by making the gap between the overlap sections 22a and 25a sufficiently small. It is not possible, and light shielding is performed in a so-called inro form.

Next, regarding the zoom configuration, the cam barrel 13 is provided with three second group cams 13c at three locations.
The follower 26 a of the second holder 26 is pressed against the second group cam 13 c by the urging force of the spring 27 and is stopped from rotating with respect to the base plate 15 by the key 28. On the other hand, it moves straight in the optical axis direction. Accordingly, the rotation of the cam barrel 13 causes the first group lens L1 to advance straight by the lead of the female helicoid 11a of the fixed barrel 11, and the second group lens L2 moves to the first group lens L1 with respect to the first group lens L1. , The first group lens L1 and the second group lens L
2 moves forward while changing the interval, and constitutes a concave-convex type zoom lens. Reference numeral 29 denotes a shutter blade.

In this embodiment having the above-described structure, the fixed cylinder 11, the outer cylinder 22, and the lens barrel cover 25 form an intaglio-type light shielding mechanism, and further, light is blocked at the helicoid coupling portion between the fixed cylinder 11 and the cam cylinder 13. As a result, a light-shielding structure without a driving load is made possible, and power saving of a zoom built-in camera and use of a small capacity battery are made possible.

[0011]

According to the present invention, as described above, the lens barrel
In any position of the linear motion of the lock,
The fixed cylinder, outer cylinder and lens barrel cover should overlap each other
By forming a fixed barrel, outer barrel, and lens barrel cover on the
External light does not enter through the gap between the lens barrel cover and
The helicoid connection between the
To prevent external light from entering through the gap between the
Therefore, compact lens barrel light shielding with a light driving load can be performed, and further, the zoom lens barrel can be driven with a small current.

[Brief description of the drawings]

FIG. 1 is a sectional view of a lens barrel of a camera with a built-in zoom lens according to an embodiment of the present invention, showing a telephoto state.

FIG. 2 is a sectional view of the lens barrel in a collapsed state.

FIG. 3 is a schematic sectional view of a conventional zoom lens barrel.

[Explanation of symbols]

L1 ··· first lens group, L2 ··· second lens group, 11 ·
・ Fixed barrel, 12 ・ ・ Main body, 13 ・ ・ Cam barrel, 14 ・ ・ Top ground plate, 15 ・ ・ Base plate, 17 ・ ・ Zoom motor, 18 ・
・ AF base plate, 22 ・ ・ Outer cylinder, 25 ・ ・ Barrel cover, 29
..Shutter blades.

Claims (1)

(57) [Claims] 1. A fixed cylinder having at least three or more female helicoids on an inner diameter portion, a cam cylinder having a male helicoid engaged with the female helicoid, a cam cylinder rotatably held and cut into the fixed cylinder. driving the lens barrel block, the cam barrel via a gear mounted on the lens barrel block engaged with the obtained key groove straight with respect to the fixed barrel with the rotation of the mosquito <br/> beam tube a zoom motor for, attached to the lens barrel block consists an outer cylinder covering the outside of the fixed barrel, the barrel cover provided outside the outer cylinder, barrel due to rotation of the cam cylinder In any position of the block's linear motion
However, the fixed barrel, the outer barrel, and the lens barrel cover are
The fixed cylinder, the outer cylinder, and the lens barrel cover are overlapped with each other.
And forming the cam cylinder and the fixed cylinder with a helicoid coupling.
A lens barrel light blocking structure of a lens shutter camera with a built-in zoom lens.