JPH0514273Y2 - - Google Patents

Description

[Detailed Description of the Invention] "Technical Field" The present invention relates to a drip-proof lens barrel used in a camera lens.

"Prior Art and its Problems" In recent years, various lens-shutter cameras with drip-proof and waterproof structures have been proposed and are commercially available. The most difficult part to waterproof in a camera is the lens barrel, which moves during focus adjustment and focal length conversion such as zooming. The lens barrel section includes a fixed lens barrel and a movable lens barrel movably housed within the fixed lens barrel. Therefore, it is necessary to waterproof the space between the fixed lens barrel and the movable lens barrel.

The conventional waterproof structure of the rotation shaft or thrust shaft is
As shown in FIG. 4, a circumferential groove 82 is formed in the end face of the flange portion 81 of the outer fixed lens barrel 80, and an O-ring 83 made of an elastic sealing material is inserted between the groove 82 and the movable lens barrel 84. A pressing member 85 that is press-fitted and attached to the fixed lens barrel 80 holds the O-ring 83 so that it does not move in the optical axis direction. The O-ring 83 connects the end face of the flange portion 81 and the movable lens barrel 8.
It was common to have a structure in which the tube elastically came into close contact with the outer surface of the tube from the radial direction (in the vertical direction in the figure) and was waterproof.

However, in general, the movable lens barrel 84 is restrained by the fixed intermediate lens barrel 40 so that the optical axis does not deviate. The fixed intermediate lens barrel 40 is connected to the main body 19.
and is aligned with the aperture 19a (see FIG. 1). On the other hand, the front cover 11, which is integrally formed with the outer cylinder 12 and the movable lens barrel 84, is also fixed to the main body 19 with screws or the like.
Therefore, since the outer tube 12 and the movable lens barrel 84 are positioned and fixed completely separately with respect to the main body, their relative positions may slightly shift due to variations in the individual parts. As a result, the pressure force between the O-ring 83 and the movable lens barrel 84 becomes uneven, resulting in insufficient waterproofing, and there is a risk that force will be applied to the movable lens barrel 89 to disturb the optical axis. Therefore, there is a problem in that the cost increases due to precision machining, and the optical axis tends to become deviated due to aging and wear of the O-ring 83.

Therefore, in conventional drip-proof cameras, the photographic lens is housed in a waterproof case (lens barrel) that is integrated with the camera body.
The photographic lens was moved within this waterproof case when adjusting the focus or changing the focal length of the lens.

However, in this conventional waterproof structure, the waterproof case must be formed to a length that can accommodate the photographic lens at its longest length. As a result, cameras with lenses that move long distances along the optical axis or cameras with zoom lenses become larger and heavier.
This will cause inconvenience for cell phones and photography.

"Purpose of the invention" The present invention was made based on the above-mentioned problem awareness, and aims to provide a drip-proof lens barrel that is compact and lightweight and can be applied to lenses with a long movement distance in the optical axis direction and zoom lenses. With the goal.

``Summary of the invention'' The invention consists of a fixed lens barrel fixed to a camera body, and a lens fitted into the fixed lens barrel so as to be movable in the direction of the optical axis or rotatable around the optical axis for zooming or In a lens barrel including a movable lens barrel that moves or rotates according to a focus adjustment operation, the fixed lens barrel is provided with a flange portion extending toward the movable lens barrel, and the flange portion is formed between the fixed lens barrel and the movable lens barrel. A retainer ring is provided on the outer periphery of the movable lens barrel, and the retainer ring includes an annular circumferential seal member that is in watertight contact with the outer circumferential surface of the movable lens barrel from the radial direction, and a retainer ring that is attached to the flange portion from the optical axis direction. It is characterized by holding an annular end face sealing member in watertight contact with.

``Embodiments of the invention'' The invention will be described below based on illustrated embodiments.
The camera to which the present invention is applied is a lens shutter type camera equipped with a zoom lens, as shown in FIG. 2.

This camera is provided with a light emitting and receiving window 20 for a range finder, a viewfinder window 21 and a light emitting window 22 for a strobe from the left at the upper front of a body 10, and below the light emitting and receiving window 20, a zoom lens 23 is provided. ing.

This zoom lens 23 consists of a front group lens L1 and a rear group lens L2, and these lenses L1,
The focal length changes as L2 moves toward and away from the lens relatively. The front group lens L1 is held within a movable lens barrel 30, and the rear group lens L2 is held in a fixed intermediate lens barrel 40 via a lens frame 41.

The outermost shell of the zoom lens 23 consists of a cylindrical outer tube (fixed lens barrel) 12 that is integrally formed with the front cover 11 of the body 10, and a movable lens barrel 30 is installed inside this outer tube 12 in the optical axis direction. It is stored and can be moved freely. The fixed intermediate barrel 40 has a rear end fixed to the body 10 and extends between the outer barrel 12 and the movable barrel 30. A cam ring 50 that rotates but does not move in the optical axis direction is fitted around the outer periphery of the fixed intermediate lens barrel 40.

A sector gear 51 is fixed to the outer periphery of the rear end of the cam ring 50, and a pinion 61 of a zoom motor 60 meshes with the sector gear 51 via a gear train. Therefore, this cam ring 50 is rotationally driven by the zoom motor 60.

A cam follower pin 32 and a guide pin 33 are implanted on the outer surface of the rear end of the movable lens barrel 30 . The cam follower pin 32 is connected to the fixed intermediate lens barrel 40.
It passes through a guide groove 44 bored parallel to the optical axis and is fitted into a cam groove 52 bored in a cam ring 50 . The guide pin 33 is fitted into a guide groove 45 bored in the fixed intermediate lens barrel 40 in parallel to the guide groove 44 . Therefore, the movable lens barrel 30 is guided forward and backward along the guide grooves 44 and 45 in parallel to the optical axis, and is rotated by the rotation of the cam ring 50 to move the cam groove 5.
It moves forward and backward while being constrained by the outline of 2. Further, a waterproof glass 34 is fixed to the tip of the movable lens barrel 30 in a watertight manner to seal the tip opening.

The lens frame 41 has a cam follower pin 42 and a pin 43 that extend radially around the outer periphery. The upper cam follower pin 42 is connected to the fixed intermediate lens barrel 40.
The lower guide pin 43 passes through the guide groove 44 and fits into the cam groove 53 bored in the cam ring 50.
is fitted into the guide groove 45. Therefore, the lens frame 41 is guided along the guide grooves 44 and 45 so as to be able to move forward and backward in the optical axis direction, and the cam ring 50
As a result of the rotation, the cam groove 53 is restrained by the contour of the cam groove 53 and moved forward and backward.

A flange portion 13 bent toward the movable lens barrel 30 is formed at the tip of the outer tube 12 . A retainer ring 35 is fitted onto the outer periphery of the movable lens barrel 30 inside the camera body 10 behind the flange portion 13 . Circumferential grooves are cut in the surface of the retainer ring 35 that faces the outer peripheral surface of the movable lens barrel 30 and the surface that faces the flange portion 13, and within these circumferential grooves, an O-ring 36 made of an elastic sealing material,
37 is inserted into the groove in a watertight manner. One O-ring 36 is in water-tight contact with the outer peripheral surface of the movable lens barrel 30, and the other O-ring 37 is in water-tight contact with the flange portion 13.

An internal thread 14 is cut on the inner circumferential surface of the outer cylinder 12 at the rear of the retainer ring 35, and an annular retaining screw 15 is screwed into the internal thread 14. This retaining screw 15 attaches the retainer ring 35 to the flange portion 13.
O-ring 37 and flange part 13
Complete the seal.

Reference numeral 16 denotes a back cover, which is pressed against the front cover 11 via a seal member 17 to keep the body 10 watertight. 18 is an intake/exhaust filter valve, which is connected to the movable lens barrel 3;
Air is taken in and discharged when the robot moves forward and backward to eliminate changes in air pressure inside the body 10. Furthermore, this suction/exhaust filter valve 1
8 is equipped with a filter that allows air to pass through but not water droplets.

Next, the zooming operation of the zoom lens 23 will be explained. When the zoom motor 60 rotates due to a zooming operation, the cam ring 50 rotates via 61 and 51, and the movable lens barrel 30 and lens frame 41 are moved relative to each other in the optical axis direction by the cam action of the cam grooves 53 and 54. It moves forward and backward while moving towards and away from the target, and the focal length changes. When zooming the zoom lens 23, the O-ring 36 is attached to the movable lens barrel 30.
However, the O-ring 37 remains in close contact with the flange portion 13 and does not come into sliding contact with it.

As described above, in this embodiment, waterproofing between the outer cylinder 12 and the movable lens barrel 30 is achieved by the O-rings 36 and 37 that are movable in the radial direction, and the retainer ring 35 is attached to the flange 13 (outer cylinder 12). On the other hand, since it is movable in the diametrical direction, misalignment between the movable lens barrel 30 and the outer barrel 12 does not affect waterproofing. Moreover, in this embodiment, no harmful force that would cause the optical axis to go awry acts between the movable lens barrel 30, the guide member that guides it in parallel, and the outer tube 12, so the optical axis will not go awry. do not have.

Note that if the outer peripheral surface of the movable lens barrel 30 is treated with Teflon, etc., the sliding friction will be reduced and the movable lens barrel 30 will be
The forward and backward movement becomes smoother, and the water repellency improves, increasing waterproof ability.

Next, another embodiment of the present invention will be described with reference to FIG. The embodiment shown in FIG. 3 has a structure in which the retainer ring 35 in the first embodiment is directly screwed into the fixed intermediate lens barrel 40. This retainer ring 70 has an internal thread 71 formed therein, and two O-rings 72 and 73 are fitted therein. The inner thread 71 of the retainer ring 70 is screwed into the outer thread 46 of the fixed intermediate lens barrel 40, and the retainer ring 70 is pressed against the flange portion 13 from the thrust direction.

In this embodiment, an example in which the present invention is applied to a movable lens barrel that only moves in a straight line has been described, but the present invention can also be applied to a movable lens barrel that rotates.

"Effect of the invention" As is clear from the above explanation, the present invention enables the movable lens barrel to be slightly moved in the direction perpendicular to the optical axis, and the annular circumferential seal member and the annular end seal member, which are waterproof members, are fixed. There is no need to increase the processing accuracy of the lens barrel, movable lens barrel, etc. beyond that of conventional lens barrels. Furthermore, it is possible to improve waterproofness, reduce costs, and make lenses and zoom lens barrels that move long distances in the optical axis direction waterproof without increasing their size.

Furthermore, since the annular circumferential seal member that contacts the outer circumferential surface of the movable lens barrel in a watertight manner from the radial direction and the annular end seal member that contacts the flange part in a watertight manner from the optical axis direction can be deformed separately, both members can be deformed separately. The deformation of one of the movable lens barrels does not affect the other, and it is possible to stabilize the pressing force on both the outer circumferential surface of the movable lens barrel and the flange portion.

[Brief explanation of the drawing]

Fig. 1 is a vertical sectional view showing the main parts of a lens shutter type camera equipped with a zoom lens barrel to which the present invention is applied, Fig. 2 is a perspective view showing the external appearance of the camera, and Fig. 3 is a FIG. 4 is a vertical cross-sectional view showing the main parts of another embodiment of the present invention, and FIG. 4 is a vertical cross-sectional view showing the main parts of a conventional waterproof mechanism. 10...Body, 12...Outer cylinder, 13...Flange portion, 14...Inner screw, 15...Press screw, 3
0...Movable lens barrel, 32...Cam follower pin, 3
3... Guide pin, 35... Retainer ring, 3
6, 37... O-ring (annular circumferential seal member, annular end seal member), 40... Fixed intermediate lens barrel, 4
1...Lens frame, 42...Cam follower pin, 4
3... Guide pin, 44, 45... Guide groove, 5
0...Cam ring, 52, 53...Cam groove, 60
...Zoom motor, 70...Annular waterproof member, 7
2, 73...O ring (annular circumferential seal member, annular end seal member).

Claims (1)

[Claims for Utility Model Registration] A fixed lens barrel fixed to the camera body; In the lens barrel equipped with a lens barrel that can be moved or rotated by an adjustment operation, a flange portion extending toward the movable lens barrel is formed on the fixed lens barrel, and a flange portion is formed between the fixed lens barrel and the movable lens barrel. , a retainer ring fitted to the outer periphery of the movable lens barrel, and an annular circumferential seal member in watertight contact with the outer circumferential surface of the movable lens barrel from the radial direction;
A drip-proof and waterproof lens barrel characterized by holding an annular end face sealing member that is in watertight contact with the flange portion from the optical axis direction.