JP2000356731A - Bellows-like member and lens barrel provided therewith - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make a bellows-like light shielding and dustproofing rubber arranged in order to prevent a light beam and a foreign matter such as, sand and dust from entering the inside of a lens barrel hardly have sand, dust and the like stuck and properly elongated and contracted. SOLUTION: A photographing lens unit 10 consists of a lens holding frame 12 which moves forward and backward in an optical axis direction and holds a photographing lens 11. A lens barrel frame 28 is constituted so that the unit 10 is supported and the frame 12 is covered by the lens 11 and provided with an aperture part 28b for the lens 11. Then, the bellows-like light shielding and dustproofing rubber 30 is elongated and contracted by following up the forward and backward movement of the frame 12 so as to surround an interval between the frames 12 and 28. Besides, the back end of the rubber 30 is held at the flange part 12d of the frame 12 and the front end thereof is held at the flange part 28a of the frame 28 by a pressing plate 31 by piercing through the aperture part 28b of the frame 28. Then, Teflon(R) based coating processing is executed at the surface of the rubber 30 in order to prevent rubber from being stuck to it.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light-shielding / dust-proof member made of an elastic bellows-like member and a lens barrel provided with the light-shielding / dust-proof member.

[0002]

2. Description of the Related Art Heretofore, a light-shielding / dustproof member for preventing light and small foreign substances such as sand and dust from entering a lens barrel has been disclosed in Japanese Patent Application No. 9-241707 filed by the present applicant. I have. The configuration of the light-blocking / dustproof member described in Japanese Patent Application No. 9-241707 is made of elastic bellows-like rubber, holds a photographing lens, and moves back and forth in the optical axis direction. Is disposed between the lens holding frame and a flange portion of the lens barrel covering the lens holding frame, surrounds a gap between the lens holding frame and the lens barrel frame, and expands and contracts following the lens holding frame moving back and forth in the optical axis direction. It is supposed to.

[0003]

However, in the structure of the prior art described above, since the light-shielding / dustproof member is made of rubber, small foreign matters such as sand and dust entering from outside adhere to the light-shielding / dustproof member. It is not easy to remove small foreign matters such as sand and dust attached. Also,
Due to the attachment of small foreign matters such as sand and dust, the compressive load of the light-shielding / dustproof member rapidly increases, and the operation of the lens holding frame is hindered. Furthermore, as the hardness of the rubber is reduced to reduce the compression load of the light-shielding / dustproof member, the adhesiveness of the rubber increases, and not only small foreign matters such as sand and dust easily adhere, but also the light-shielding / dustproofness. If the members are brought into close contact with each other in a compressed state, even if the lens holding frame moves, the light-shielding / dust-proof member will remain in a tight contact state, and the light-shielding / dust-proof member will not be able to return to itself due to its repulsive force. A gap is generated between the dust-proof member and the lens holding frame or between the light-shielding / dust-proof member and the lens barrel frame, and there is a problem in that light and small foreign matters such as sand and dust enter.

The present invention has been made in consideration of the above-mentioned problems of the prior art, and prevents the light-shielding / dust-proof member from sticking, thereby preventing the adhesion of small foreign substances such as sand and dirt, and preventing small foreign substances such as sand and dirt from adhering. It is a first object of the present invention to provide a light-shielding / dust-proof member that can be easily and reliably removed and that can self-recover by utilizing a repulsive force when the light-shielding / dust-proof member is compressed. Further, the present invention prevents an increase in the compressive load of the light-shielding / dustproof member due to the attachment of small foreign matter such as sand or dust, does not hinder the operation of the lens holding frame, and also prevents the lens holding frame from moving into the lens barrel. It is a second object of the present invention to provide a lens barrel that can reliably prevent light and small foreign substances such as sand and dust. Further, the present invention is capable of self-returning by the repulsive force of the light-shielding / dustproof member even when the light-shielding / dustproof member is brought into close contact with the compressed state, thereby reliably preventing light rays entering the lens barrel. It is a third object to provide a lens barrel capable of performing the following.

[0005]

In order to achieve the above-mentioned object, the present invention provides a light-shielding / dustproof member by coating the surface of a bellows-like member. It is arranged between the movable lens support member and its supporting member.

[0006]

DETAILED DESCRIPTION OF THE INVENTION The present invention according to the first aspect of the present invention prevents small foreign substances such as sand and dust from adhering by coating a surface of an elastic bellows-like member. According to the second aspect of the present invention, since the bellows-like member is a light-shielding / dustproof member made of an elastic member, the surface has no stickiness, so that adhesion of small foreign matters such as sand and dust is prevented, and the bellows-like member is adhered in a compressed state. Even if it does, the self-returning is performed by the repulsive force of the light shielding / dustproof member. According to the third aspect of the present invention, since the coating material of the coating process is a Teflon-based or fluorine-based material, the surface of the bellows-like member is free from sticking.
Prevents adhesion of foreign matter such as sand and dust.

According to a fourth aspect of the present invention, there is provided a lens group comprising a photographing lens and a lens holding member for holding the photographing lens, the lens group being movable back and forth in the optical axis direction, and an opening for the photographing lens. A support member having a bellows-shaped member positioned between the lens holding member and the support member, surrounding a gap between the lens holding member and the support member, and expanding and contracting following the longitudinal movement of the lens group; By coating the surface of the bellows-like member with the lens barrel provided with, it is possible to prevent a sudden change in the compressive load of the bellows-like member due to the attachment of small foreign matter such as sand or dust, and hold the lens. There is no hindrance to the member extending operation, and the member expands and contracts following the lens holding member, so that the gap between the lens holding member and the support member can be reliably surrounded.
According to the present invention, the bellows-like member is a light-shielding / dustproof member made of an elastic member, thereby preventing a sudden change in the compressive load of the light-shielding / dustproof member due to adhesion of a small foreign substance such as sand or dust. It does not interfere with the extension operation of the lens holding member, and also self-returns by the repulsive force when the light shielding / dustproof member is compressed, and expands and contracts following the lens holding member. The gap between the holding member and the support member can be reliably surrounded, thereby preventing light rays and small foreign substances such as sand and dust entering the lens barrel.

According to a sixth aspect of the present invention, there is provided a first lens group including a first photographic lens, a first lens holding member for holding the first photographic lens, a second photographic lens, and a second photographic lens. A second lens holding member for holding the taking lens;
A lens group, a first support member that supports the first lens group to be able to move back and forth in the optical axis direction, a second support member that supports the second lens group to be able to move back and forth in the optical axis direction, The first lens group is located between the first support member and the second support member, and surrounds a gap between the first support member and the second support member.
In a lens barrel having a bellows-like member that expands and contracts following a change in the distance between the lens groups, the surface of the bellows-like member is coated, so that the bellows-like member self-returns by a repulsive force when compressed. Since the first lens group and the second lens group extend following the change in the distance between the first lens group and the second lens group, the gap between the first lens group and the second lens group can be reliably surrounded, and the lens enters the lens barrel. Light rays are reliably prevented. According to a seventh aspect of the present invention, the bellows-like member is made of an elastic member.
Since the light-shielding / dust-proof member is a dust-proof member, the light-shielding / dust-proof member is self-recovered by a repulsive force when it is compressed, and extends following a change in the distance between the first lens group and the second lens group. Can reliably surround the gap between the lens and the second lens group,
Light rays entering the lens barrel are reliably prevented. According to the present invention as set forth in claim 8, since the coating material of the coating process of the bellows-like member is a Teflon-based or fluorine-based material, the surface of the bellows-like member is free from sticking, so that foreign matter such as sand and dust can be prevented from adhering. Prevent surely.

[0009]

1 to 6 show a first embodiment of the present invention.
It will be described based on. FIG. 1 is an exploded perspective view of a shutter / focus unit disposed in the lens barrel of the present embodiment, FIG. 2 is an exploded perspective view of a lens barrel provided with a light-shielding / dustproof rubber, and FIG. Fig. 4 is a vertical sectional view.
FIG. 3 is a longitudinal sectional view of the lens barrel in a state where dustproof rubber is compressed. First, referring to FIG.
Will be described. Reference numeral 2 denotes a shutter unit, which includes a shutter base plate 3 having a photographing opening 3a formed therein, a shutter blade 4 disposed behind the shutter base plate 3, and a holding plate 5 for holding the shutter blade 4 on the shutter base plate 3. ,
An actuator 6 for driving shutter blades is provided in front of the shutter base plate 3.

Reference numeral 7 denotes a focus gear, which is a motor 1 described later.
7 is transmitted to a feed screw 15 described later. The focus gear 7 is rotatably fitted and supported on a gear shaft 3b formed on the shutter base plate 3, and is supported by a focus base plate 8 described later. 8 is a focus ground plate, 2
It is fixed to the shutter base plate 3 by a book screw 9.
Reference numeral 10 denotes a photographing lens unit (lens group) which is movable in the optical axis direction, and includes a photographing lens 11 and a lens holding frame (lens holding member) 12 for holding the photographing lens 11.
And a hollow cylindrical fitting metal 13 fixed to the arm 12a formed on a part of the outer periphery of the lens holding frame 12 by press fitting, and a pulse plate 14 fixed by bonding.

Reference numeral 15 denotes a feed screw, which is disposed in parallel with the photographing optical axis and moves the photographing lens unit 10 back and forth in the optical axis direction. A gear 15a and a male screw 15b are formed, and a shaft is provided at each end. 15c and 15d are formed. The gear 15a meshes with the focus gear 7, the male screw 15b meshes with a female screw 16a formed on a nut 16 described later, and the shaft 15c passes through a hole 8a formed on the focus ground plate 8. The shaft 15d is formed in the hole 3c formed in the shutter base plate 3, and the hole 12b formed in the arm 12a of the lens holding frame 12.
19b formed in the supporting base plate 19 to be described later
By being fitted to each other, the camera unit is rotatably supported and the photographing lens unit 10 is supported by the shutter unit 2. Numeral 16 denotes a nut, which is incorporated in a notch 12c formed in an arm 12a of the lens holding frame 12, and a female screw 1 formed in the notch 12c.
The engagement of the male screw 6a with the male screw 15b of the feed screw 15 causes the photographic lens unit 10 to move back and forth in the optical axis direction along the lead of the male screw 15b of the feed screw 15.

Reference numeral 17 denotes a cylindrical motor, which is a drive source for moving the photographing lens unit 10 back and forth in the optical axis direction. A pinion gear 17a incorporated at the tip of the drive unit meshes with the focus gear 7. The motor 17 is disposed parallel to the photographing optical axis, and its rear portion is provided in a hole 8b formed in the focus base plate 8, and its front portion is provided in a hole 19c formed in a support base plate 19 described later. The fitting is supported by the shutter unit 2. Reference numerals 18 and 21 are guide shafts arranged in parallel with the photographing optical axis and supporting the photographing lens unit 10 in the optical axis direction. The guide shaft 18 is supported by fitting a rear portion thereof into a hole 8c formed in the focus base plate 8 and a front portion thereof into a hole (not shown) formed in the support base plate 19, respectively. The lens holding frame 12 is slidably fitted with a U-shaped notch (not shown) formed at a position facing the arm 12a. On the other hand, the guide shaft 21 has a rear portion formed in a hole 8d formed in the focus base plate 8 and a front portion formed in an adjustment plate 24 to be described later through a hole 19d formed in the support base plate 19. Each of the holes 24a is supported by being fitted thereto, and is slidably fitted with the fitting metal 13 fixed to the lens holding frame 12.

A supporting base plate 19 supports the photographing lens unit 10, the feed screw 15, the motor 17, and the guide shaft 18, and is connected to the shutter base plate 3 and the focus base plate 8 by three screws 20. Fixed. A lens spring 22 penetrates the hole 19d of the support base plate 19, is disposed between the arm portion 12a of the lens holding frame 12 and an adjustment plate 24 described later, and urges the photographing lens unit 10 backward. ing.

Reference numeral 23 denotes a tilt adjusting plate which adjusts the tilt of the taking lens unit 10 with respect to the center of the optical axis, and is fixed to the support base plate 19 by screws 25 via washers 24. Reference numeral 26 denotes an eccentric shaft for operating the tilt adjustment plate 23. The eccentric shaft 26 has a hole 19 formed in the support base plate 19.
e and a hole 23b formed in the tilt adjustment plate 23 so as to be rotatable, and is held by the support base plate 19 by the tilt adjustment plate 23. The shutter / focus unit 1 having the above configuration is covered by being fixed to a flange portion 28a formed on a lens barrel frame (supporting member) 28 with three screws 29 as shown in FIG. Flange 2 of the lens barrel frame 28
8a, an opening 28b set to be larger than the outer diameter of the light-shielding / dustproof rubber 30 described later, three camshafts 28c at the outer peripheral rear end, and two straight keys 28d at the inner peripheral surface. But,
Each is formed.

Numeral 30 denotes an elastic bellows-like rubber (elastic member).
Light-shielding / dust-proof rubber (light-shielding / dust-proof member) composed of
In order to prevent the rubber from sticking to the surface, it has been coated with Teflon or fluorine,
It is located between the lens holding frame 12 and the lens barrel frame 28 and surrounds a gap between the two frames to prevent light and small foreign substances such as sand and dust from entering the lens barrel. The shading
The dustproof rubber 30 penetrates through the opening 28b of the lens barrel frame 28,
The rear end side of the lens holding frame 12 is held by a flange portion 12d formed on the lens holding frame 12, and the front end side thereof is held by a pressing plate 31 described later, and moves forward and backward in the optical axis direction within the lens barrel frame 28. Follow and expand and contract. Reference numeral 31 denotes a holding plate, which is disposed in front of the flange portion 28a of the lens barrel frame 28, holds the light-shielding / dustproof rubber 30, and has an opening 31a smaller than the outer diameter of the light-shielding / dustproof rubber 30. ing.

Reference numeral 32 denotes a barrier drive ring,
8 is disposed in front of the flange portion 28a,
The lens barrel is rotatably fitted and supported around the optical axis of the photographing lens, and transmits the collapsing operation of the lens barrel to a barrier device 34 described later to open and close the two barrier blades 36.
A barrier drive ring spring 33 is disposed above and below the barrier drive ring 32 and urges a barrier blade 36 of a barrier device 34 described later in the opening direction. Shaft 28e formed in
The other end is hooked on a hook 32a formed on the barrier drive ring 32, respectively. Numeral 34 denotes a barrier device, which is disposed in front of the barrier drive ring 32 and is fixed to the lens barrel frame 28.
5, at least two barrier blades 36 for opening and closing the opening 35a formed in the nozzle 5, a barrier spring (not shown) for urging the barrier blades 36 in the opening direction, and a fixing plate for fixing the barrier blades 36 to the barrier base plate 35 37.

The focus driving of the present embodiment having the above configuration will be described. When the photographing lens unit 10 is extended from the state shown in FIG. 3, when the motor 17 is energized, the pinion gear 17a is rotated by the motor 17. The rotational force of the pinion gear 17a is transmitted to the gear 15a of the feed screw 15 via the focus gear 7 to rotate the feed screw 15, and the photographing lens unit 10 moves along the lead of the male screw 15b of the feed screw 15 via the nut 16. While the lens spring 22 and the light-shielding / dustproof rubber 30 are charged, the lens spring 22 moves in the optical axis direction as shown in FIG.

On the other hand, when the photographing lens unit 10 is retracted from the state shown in FIG. 4, by driving the reverse of the above-mentioned extending operation, the photographing lens unit 10 leads the male screw 15 b of the feed screw 15 through the nut 16. along,
As shown in FIG. 3, the lens barrel 28 moves in the optical axis direction in the lens barrel frame 28.
At this time, the light-shielding / dust-proof rubber 30 self-recovers using the repulsive force when charged, and extends following the photographic lens unit 10. According to the present embodiment, the light-shielding / dustproof rubber 30
By performing the coating treatment on the surface, the surface of the light-shielding / dustproof rubber 30 is not sticky, so that it is possible to prevent small foreign substances such as sand and dust entering from the outside from adhering. Further, since small foreign matters such as sand and dirt can be easily and reliably removed, it is possible to prevent a sudden change in the compression load of the light-shielding / dustproof rubber 30 due to the adhesion of small foreign substances such as sand and dirt. In addition, there is no problem in the operation of extending the lens holding frame 12. Further, the light-shielding / dustproof rubber 30 can be self-recovered by a repulsive force when the rubber 30 is compressed, and the light-shielding / dustproof rubber 30 adhered to the lens holding frame 1
2 can be reliably extended by following the retraction operation, so that the gap between the lens holding frame 12 and the lens barrel frame 28 can be reliably surrounded, and external light rays and sand that enter the lens barrel. Small foreign substances such as dust can be reliably prevented.

FIGS. 5 and 6 show examples of the use of a zoom lens barrel in which the light-shielding / dustproof rubber 30 having the above-described configuration is incorporated.
The same parts as those in the above-described embodiment are denoted by the same reference numerals, and description thereof will be omitted. In the figure, reference numeral 40 denotes a fixed cylinder, which is fixed to the camera body 48 by a screw 47, and has a helicoid screw 40a, two rectilinear grooves 40b, and a hole 40c extending in the optical axis direction formed on the inner periphery thereof. Reference numeral 41 denotes a first rotary cylinder, which is rotatably supported on the outer periphery of a first rectilinear cylinder 42 described later, and a helicoid screw 41a formed at the outer rear end of the first rotary cylinder meshes with a helicoid screw 40a of the fixed cylinder 40. Due to this engagement, the fixed cylinder 40 is supported by the fixed cylinder 40 and moves back and forth in the optical axis direction while rotating along the lead of the helicoid screw 40a of the fixed cylinder 40. A gear portion 41c is formed on the helicoid screw 41a of the first rotary cylinder 41, and two rectilinear grooves 41b are formed on an inner peripheral portion thereof.

Reference numeral 42 denotes a first rectilinear cylinder, and the first rotary cylinder 41
, And moves back and forth in the optical axis direction integrally with the first rotary cylinder 41. At this time, in the first rectilinear cylinder 42, two convex portions 42b formed on the flange portion 42a at the rear end thereof are slidably fitted in the two rectilinear grooves 40b of the fixed cylinder 40. , And moves back and forth in the optical axis direction using the two rectilinear grooves 40b as guides. Further, three cam grooves 42c and two rectilinear grooves 42d are formed on the inner peripheral surface of the first rectilinear cylinder 42, and two cam grooves 42c having the same lead angle as the three cam grooves 42c are formed. Are formed. A second rotary cylinder 43 is rotatably supported on the outer periphery of a second rectilinear cylinder 45 described later, and three cam shafts 43a formed on the rear end of the outer periphery thereof have three camshafts 43a of the first rectilinear cylinder 42. The three camshafts 43a are slidably fitted in the cam grooves 42c, are supported by the first rectilinear barrel 42 by fitting the three camshafts 43a, and extend along the cam grooves 42c of the first rectilinear barrel 42. Move back and forth in the optical axis direction while rotating. Further, three cam grooves 43b and 43c are formed on the inner periphery of the second rotary cylinder 43, respectively.

Reference numeral 44 denotes a transmission shaft for transmitting the rotational force of the first rotary cylinder 41 to the second rotary cylinder 43, which is attached to the rear end of the second rotary cylinder 43, and The first rotary cylinder 4 penetrates through the two cam holes 42 e of the rectilinear cylinder 42.
One of the two rectilinear grooves 41b is slidably fitted. 4
Reference numeral 5 denotes a second rectilinear cylinder, which is supported on the inner peripheral side of the second rotary cylinder 43, and moves back and forth in the optical axis direction integrally with the second rotary cylinder 43. At this time, in the second rectilinear cylinder 45, two convex portions 45b extending in the outer peripheral direction formed on the flange portion 45a at the rear end thereof are slidable in the two rectilinear grooves 42d of the first rectilinear cylinder 42. Because of the engagement, the second rectilinear barrel 45 moves back and forth in the optical axis direction with the two rectilinear grooves 42d of the first rectilinear barrel 42 serving as guides. The second rectilinear barrel 45 has three rectilinear holes 45c penetrating therethrough, and two rectilinear grooves 45d formed on the outer periphery.

Reference numeral 46 denotes a second lens holding frame, which includes three camshafts 46 formed at the distal end of a convex portion 46a projecting from the outer peripheral portion.
b penetrates through the three rectilinear holes 45c of the second rectilinear cylinder 45 and is slidably fitted into the three cam grooves 43b of the second rotary cylinder 43. By the fitting of the three cam shafts 46b, the second lens holding frame 46 is supported by the second rotary cylinder 43, and is moved back and forth in the optical axis direction along the cam grooves 43b of the second rotary cylinder 43. Move. At this time, since the three cam shafts 46b of the second lens holding frame 46 are slidably fitted in the three rectilinear holes 45c of the second rectilinear barrel 45,
The rectilinear cylinder 45 is moved back and forth in the optical axis direction using the three rectilinear holes 45c as guides.

The lens barrel frame 28 has three cam shafts 28c formed at the rear end thereof slidably fitted in the three cam grooves 43c of the second rotary cylinder 43. By this fitting, the lens barrel frame 28, the shutter / focus unit 1 and the photographing lens unit 10 supported by the lens barrel frame 28 are supported by the second rotary barrel 43, and the second rotary barrel 43 It moves back and forth in the optical axis direction along the cam groove 43c. At this time, since the two rectilinear keys 28d formed on the inner peripheral portion of the lens barrel frame 28 are slidably fitted in the two rectilinear grooves 45d of the second rectilinear cylinder 45, 2 straight barrel 4
5 is moved back and forth in the optical axis direction with the straight groove 45d as a guide. Reference numeral 49 denotes a drive unit, which includes a motor 51 having a gear 51a fixed to a gear base plate 50 and gears 52a to 52
f is rotatably fitted to and supported by a gear base plate 50, and is held by a pressing plate (not shown).
Through the hole 40c, and the gear portion 41 of the first rotary cylinder 41
It is engaged with c.

The operation of the zoom lens barrel having the above configuration will be described. When a zoom switch (not shown) provided on the camera body 48 is switched between the wide direction and the tele direction, the motor 51 rotates, and the rotational force of the gear 51a is changed to the gear 5a.
The power is transmitted to the gear portion 41c of the first rotary cylinder 41 via 2a to 52f. The first rotating cylinder 41 to which the rotational force has been transmitted is the first rotating cylinder 41.
While rotating around the outer circumference of the rectilinear barrel 42, it moves back and forth in the optical axis direction along the lead of the helicoid screw 40 a of the fixed barrel 40. At this time, the first rectilinear tube 42 moves back and forth while moving straight in the optical axis direction with the rectilinear groove 40b of the fixed tube 40 as a guide.

The torque of the first rotary cylinder 41 is transmitted to the second rotary cylinder 43 via two transmission shafts 44. The second rotary cylinder 43 to which the rotational force has been transmitted rotates around the outer periphery of the second rectilinear cylinder 45, and the three cam grooves 42c of the first rectilinear cylinder 42
Along the optical axis. At this time, the second rectilinear barrel 45 moves back and forth while traveling straight in the optical axis direction using the two rectilinear grooves 42d of the first rectilinear barrel 42 as a guide. At this time, the second rectilinear barrel 45 moves back and forth while traveling straight in the optical axis direction using the rectilinear grooves 42d of the first rectilinear barrel 42 as a guide. Also,
As the second rotary cylinder 43 rotates, the second lens holding frame 46 is further supported along the three cam grooves 43b of the second rotary cylinder 43, and further supported by the lens barrel frame 28 and the lens barrel frame 28. The shutter / focus unit 1 and the photographing lens unit 10 move back and forth in the optical axis direction along the cam groove 43c of the second rotary cylinder 43. At this time, the second lens holding frame 46 and the lens barrel frame 28 move back and forth in the optical axis direction using the three rectilinear holes 45c of the second rectilinear cylinder 45 as guides.

FIGS. 7 to 9 show a second embodiment of the present invention. FIG. 7 is a vertical sectional view of the zoom lens barrel of the present embodiment in the telephoto state, FIG. 8 is a vertical sectional view of the zoom lens barrel in the retracted state, and FIG. 8 is an enlarged sectional view of the light-shielding / dustproof rubber in the retracted state. The configuration of the camera body 48 is described in the first section above.
This is the same as FIG. 6 of the embodiment. In the figure, reference numeral 60 denotes a fixed cylinder, which is fixed to the camera body 48 shown in FIG.
A helicoid screw 60a and two rectilinear grooves 60
b and a penetrating cam hole 60c having the same lead angle as the helicoid screw 60a. Reference numeral 61 denotes a first rotary cylinder, which is rotatably supported on the outer circumference of the fixed cylinder 60, and has a helicoid screw 61a formed on the outer circumference thereof, and meshes with the gear 52f of the drive section 49 of the camera body 48 in FIG. On its inner peripheral part, two rectilinear grooves 61b are formed.

Reference numeral 62 denotes a second rotary cylinder which is rotatably supported on the outer periphery of a first rectilinear cylinder 64 which will be described later, and a helicoid screw 62a formed at the rear end of the outer periphery thereof is combined with a helicoid screw 60a of the fixed cylinder 60. Are engaged. By this engagement, the three second rotating cylinders 62 are supported by the fixed cylinder 60, and move back and forth in the optical axis direction while rotating along the leads of the helicoid screw 60a of the fixed cylinder 60. The inner peripheral portion of the second rotary cylinder 62 has three cam grooves 62 each.
b, 62c and 62d are formed.

Reference numeral 63 denotes a transmission shaft for transmitting the rotational force of the first rotary cylinder 61 to the second rotary cylinder 62. The transmission shaft 63 is attached to the rear end of the second rotary cylinder 62. 6
0, and penetrates through the two cam holes 60c, and is slidably fitted into the two rectilinear grooves 61b of the first rotary cylinder 61. Reference numeral 64 denotes a first rectilinear cylinder, which is disposed and supported on the inner peripheral side of the second rotary cylinder 62, and moves back and forth in the optical axis direction integrally with the second rotary cylinder 62. At this time, the first rectilinear cylinder 64 has two convex portions 64b extending in the outer peripheral direction formed on the flange portion 64a at the rear end thereof slidably fitted into the two rectilinear grooves 60b of the fixed cylinder 60. Therefore, the first straight barrel 64 is fixed to the fixed barrel 6.
It moves back and forth in the optical axis direction using the two straight grooves 60b as the guides. The first rectilinear barrel 64 has three rectilinear holes 64c penetrating therethrough.

Reference numeral 65 denotes a fourth lens group, which includes a fourth photographing lens 66 and a fourth lens holding frame 67 for holding the fourth photographing lens 66. The fourth lens group 65 has a flange portion 67a of the fourth lens holding frame 67. Three camshafts 67b formed at the tip end penetrate through the three rectilinear holes 64c of the first rectilinear barrel 64, and slidably fit in the three cam grooves 62b of the second rotary cylinder 62. are doing. By the fitting of the three camshafts 67b, the fourth lens group 65 is supported by the second rotary cylinder 62, and is moved back and forth in the optical axis direction along the cam grooves 62b of the second rotary cylinder 62. Move. At this time, since the three cam shafts 67b of the fourth lens holding frame 67 are slidably fitted in the three rectilinear holes 64c of the first rectilinear cylinder 64, the first rectilinear cylinder 6
The four rectilinear holes 64c are used as guides to move back and forth in the optical axis direction.

Reference numeral 68 denotes a shutter / focus unit (second support member) which includes a shutter base plate 69, a shutter drive unit (not shown), a focus drive unit 70, and a third lens group 71 described later. A cam shaft 69b formed at the end of the flange portion 69a penetrates the three rectilinear holes 64c of the second rectilinear cylinder 64, and slidably fits into the three cam grooves 62c of the second rotary cylinder 62. are doing. By fitting the cam shaft 69b, the shutter / focus unit 68, the third lens group 71, and the second lens group 74
Is supported by the second rotary cylinder 62 and moves forward and backward in the optical axis direction along three cam grooves of the second rotary cylinder 62. At this time, the three cam shafts 69b of the shutter base plate 69 are slidably fitted with the three rectilinear holes 64c of the first rectilinear barrel 64. The first rectilinear barrel 64 moves forward and backward in the optical axis direction with the rectilinear hole 64c serving as a guide.

Reference numeral 71 denotes a third lens group, which includes a third photographing lens 72 and a third lens holding frame 73 for holding the third photographing lens 72. Forward and backward in the optical axis direction. A second lens group 74 includes a second photographing lens 75 and a second lens holding frame 76 for holding the second photographing lens 75, and is fixed in front of the shutter / focus unit 68. It moves forward and backward in the optical axis direction integrally with the focus unit 68.

Reference numeral 77 denotes a lens barrel frame (first support member). Three cam shafts 78 attached to three convex portions 77a formed on the rear end of the outer periphery of the lens barrel frame 77 It penetrates through the three rectilinear holes 64c and is slidably fitted in the three cam grooves 62d of the second rotary cylinder 62. The fitting of the cam shaft 78 causes the lens barrel frame 77 and a first lens group 7 described later.
9 is supported by the second rotary cylinder 62 and moves back and forth in the optical axis direction along a cam groove 62d of the second rotary cylinder 62. At this time, since the three convex portions 77a of the lens barrel frame 77 are slidably fitted with the three rectilinear holes 64c of the first rectilinear cylinder 64, the rectilinear holes of the first rectilinear cylinder 64 are provided. It moves back and forth in the optical axis direction using 64c as a guide. Reference numeral 78 denotes a first lens group, which includes a first photographing lens 79 and a first lens holding frame 80 for holding the first photographing lens 79, and the lens barrel frame 77.
And moves forward and backward in the optical axis direction integrally with the lens barrel frame 77.

Reference numeral 81 denotes an elastic bellows-like rubber (elastic member).
Light-shielding / dust-proof rubber (light-shielding / dust-proof member) composed of
In order to prevent the rubber from sticking to the surface, it has been coated with Teflon or fluorine,
The second lens group 74 and the first lens group 78 expand and contract in accordance with a change in the interval. The light-shielding / dust-proof rubber 81 is provided between the second lens group 74 and the lens barrel frame 77.
Between the second lens group 74 and the first lens group 78, and penetrates into the gap between the second lens group 74 and the lens barrel frame 77. Light passing through the first photographing lens 79 is prevented.

The operation of the zoom lens barrel having the above configuration will be described. When the main switch (not shown) provided on the camera body 48 is turned off from the state shown in FIG. 7, the motor 51 shown in FIG.
The torque of the gear 51a is transmitted to the gear portion 61a of the first rotating cylinder 61 via the gears 52a to 52f. The first rotating cylinder 61 to which the rotational force has been transmitted rotates around the outer periphery of the fixed cylinder 60.
The torque of the first rotary cylinder 61 is transmitted to the second rotary cylinder 62 via two transmission shafts 63. The second rotary cylinder 62 to which the rotational force has been transmitted is rotated in the optical axis direction along the lead of the helicoid screw 60 a of the fixed cylinder 60 while rotating around the outer periphery of the first rectilinear cylinder 64. At this time, the first straight barrel 64 is fixed to the fixed barrel 6.
With the straight groove 60b of 0 as a guide, the light beam moves straight in the optical axis direction.

At this time, the rotation of the second rotary cylinder 62 causes
The fourth lens group 65 extends along the three cam grooves 62b, and the shutter / focus unit 68, the third lens group 71 and the second lens group 74 extend along the cam groove 62c.
The lens barrel frame 77 and the first lens group 78 are provided with a cam groove 62d.
Along the direction of the optical axis, and the retracted state shown in FIG. 8 is obtained. At this time, the fourth lens group 65, the shutter / focus unit 68, the third lens group 71 and the second
Lens group 74, lens barrel frame 77, and first lens group 78
Moves linearly in the optical axis direction using the three rectilinear holes 64c of the second rectilinear barrel 64 as guides. In addition, light shielding and dustproof rubber 8
1 is charged by the movement of the barrel frame 77 until it comes into close contact as shown in FIGS.

The camera body 48 is moved from the state shown in FIG.
When a main switch (not shown) provided on the camera is turned on, each drive unit performs an operation opposite to that described above to be in a wide state, and when a zoom switch (not shown) provided on the camera body 48 is switched to the tele direction, As shown in FIG. At this time, the light-shielding / dustproof rubber 81 follows the lens barrel frame 77 and expands by using the repulsive force when charged.

As described above, according to this embodiment,
By performing the coating treatment on the surface of the light-shielding / dustproof rubber 81, the surface of the light-shielding / dustproof rubber 81 is no longer adhered, and the light-shielding / dustproof rubber 81 can be self-recovered by a repulsive force when compressed. The light-shielding / dust-proof rubber 81 can be reliably extended following the change in the distance between the first lens group 78 and the second lens group 74, and the light rays that enter the lens barrel can be reliably prevented. it can.

[0038]

As described above, according to the first aspect of the present invention, since the surface of the stretchable bellows-like member is coated, small foreign matters such as sand and dust are prevented from adhering. According to the second aspect of the present invention, since the bellows-like member is a light-shielding / dustproof member made of an elastic member, the surface has no stickiness, so that adhesion of small foreign matters such as sand and dust is prevented, and the bellows-like member is adhered in a compressed state. Even if it does, the self-returning is performed by the repulsive force of the light shielding / dustproof member. According to the third aspect of the present invention, since the coating material of the coating process of the bellows-like member is a Teflon-based or fluorine-based material, the surface of the bellows-like member is free from sticking, so that foreign matter such as sand and dust can be prevented from adhering. Prevent surely.

According to a fourth aspect of the present invention, there is provided a lens group comprising a photographing lens and a lens holding member for holding the photographing lens, the lens group being movable back and forth in an optical axis direction, and an opening for the lens group for supporting the lens group. And a bellows-shaped member which is located between the lens holding member and the support member, surrounds a gap between the lens holding member and the support member, and expands and contracts in accordance with the longitudinal movement of the lens group. By coating the surface of the bellows-like member with a lens, a sharp change in the compression load of the bellows-like member due to adhesion of small foreign matter such as sand or dust can be prevented. The extension of the holding member does not interfere with the extension operation of the holding member, and expands and contracts following the lens holding member, so that the gap between the lens holding member and the support member can be reliably surrounded.
According to the present invention, the bellows-like member is a light-shielding / dustproof member made of an elastic member, thereby preventing a sudden change in the compressive load of the light-shielding / dustproof member due to adhesion of a small foreign substance such as sand or dust. It does not interfere with the extension operation of the lens holding member, and also self-returns by the repulsive force when the light shielding / dustproof member is compressed, and expands and contracts following the lens holding member. The gap between the holding member and the support member can be reliably surrounded, thereby preventing light rays and small foreign substances such as sand and dust entering the lens barrel.

According to a sixth aspect of the present invention, there is provided a first lens group including a first photographic lens, a first lens holding member for holding the first photographic lens, a second photographic lens, and a second photographic lens. A second lens holding member for holding the taking lens;
A lens group, a first support member that supports the first lens group to be able to move back and forth in the optical axis direction, a second support member that supports the second lens group to be able to move back and forth in the optical axis direction, The first lens group is located between the first support member and the second support member, and surrounds a gap between the first support member and the second support member.
In a lens barrel having a bellows-like member that expands and contracts following a change in the distance between the lens groups, the surface of the bellows-like member is coated, so that the bellows-like member self-returns by a repulsive force when compressed. Since the first lens group and the second lens group extend following the change in the distance between the first lens group and the second lens group, the gap between the first lens group and the second lens group can be reliably surrounded, and the lens enters the lens barrel. Light rays are reliably prevented. According to a seventh aspect of the present invention, the bellows-like member is made of an elastic member.
Since the light-shielding / dust-proof member is a dust-proof member, the light-shielding / dust-proof member is self-recovered by a repulsive force when it is compressed, and extends following a change in the distance between the first lens group and the second lens group. Can reliably surround the gap between the lens and the second lens group,
Light rays entering the lens barrel are reliably prevented. According to the present invention as set forth in claim 8, since the coating material of the coating process of the bellows-like member is a Teflon-based or fluorine-based material, the surface of the bellows-like member is not sticky, so that foreign matter such as sand and dust can be prevented from adhering. Prevent surely.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view of a shutter / focus unit disposed in a lens barrel according to an embodiment of the present invention.

FIG. 2 is an exploded perspective view of a lens barrel in which a light-shielding / dustproof rubber is arranged.

FIG. 3 is a longitudinal sectional view of the lens barrel in a state where the lens holding frame stands by at a position where the lens holding frame is most retracted.

FIG. 4 is a longitudinal sectional view of the lens barrel in a state where the lens holding frame is extended.

FIG. 5 is a vertical sectional view of a zoom lens barrel in which a light-shielding / dustproof rubber is incorporated as an example of use of the lens barrel.

6 is a front view of a main part of a camera incorporating the zoom lens barrel of FIG. 6;

FIG. 7 is a longitudinal sectional view of a zoom lens barrel according to a second embodiment of the present invention in a telephoto state.

FIG. 8 is also a longitudinal sectional view of the retracted state.

FIG. 9 is an enlarged sectional view of the light-shielding / dustproof rubber in the collapsed state.

[Explanation of symbols]

1. Shutter focus unit, 10. Photographic lens unit (lens group), 11. Photographic lens, 12
..Lens holding frame (lens holding member), 12d..flange part, 17.motor, 19..support base plate, 19a.
· Opening, 28 ··· Barrel frame (supporting member), 28a ··· Flange, 28b ··· Opening, 30, 81 · · · Shading and dustproof rubber (shading and dustproof member), 31 · · · Holding plate, 31a・
Opening, 68, shutter focus unit (second support member), 74 second lens group, 75 second photographing lens, 76 second lens holding frame, 77 lens barrel Frame (first support member), 78 first lens group, 7
9 First lens, 80 First lens holding frame.

Claims (8)

[Claims] 1. A bellows-like member wherein a surface of a stretchable bellows-like member is coated. 2. The bellows-like member is made of an elastic member.
The bellows-like member according to claim 1, wherein the bellows-like member is a dustproof member. 3. The bellows-like member according to claim 1, wherein the coating material for the coating treatment is a Teflon-based material or a fluorine-based material. 4. A lens group comprising a photographing lens and a lens holding member for holding the photographing lens, the lens group being movable back and forth in the optical axis direction; a supporting member supporting the lens group and having an opening for the photographing lens; A lens barrel including a bellows-shaped member positioned between the lens holding member and the support member, surrounding a gap between the lens holding member and the support member, and expanding and contracting following the forward and backward movement of the lens group; 2. The lens barrel according to claim 1, wherein the surface of the bellows-like member is coated. 5. The light-shielding member according to claim 1, wherein the bellows-like member is an elastic member.
The lens barrel according to claim 4, wherein the lens barrel is a dustproof member. 6. A first lens group including a first photographic lens and a first lens holding member that holds the first photographic lens, and a second lens that holds the second photographic lens and the second photographic lens. A second lens group comprising a lens holding member, a first support member for supporting the first lens group so as to be able to move back and forth in the optical axis direction, and a second support for supporting the second lens group so as to be able to move back and forth in the optical axis direction The first lens group and the second lens are located between the first support member and the second support member, and are located between the first support member and the second support member. What is claimed is: 1. A lens barrel comprising a bellows-shaped member which expands and contracts according to a change in distance between groups, wherein a surface of said bellows-shaped member is coated. 7. The bellows-like member is made of an elastic member.
The lens barrel according to claim 6, wherein the lens barrel is a dustproof member. 8. The lens barrel according to claim 4, wherein the coating material for coating the bellows-shaped member is a Teflon-based or fluorine-based coating material.