JP3393028B2 - Support device for front lens group of 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 support device for a front lens group of a zoom lens.

[0002]

2. Description of the Related Art For example, a zoom lens having two lens groups, a front lens group and a rear lens group,
There are a type in which the front lens group is screwed to a shutter unit fixed to a moving lens barrel which is extended from the camera body and supported by the moving lens barrel, and a type in which the front lens group is directly fixed to the moving lens barrel. .

In such a two-group type zoom lens, it is necessary to make the optical axes of the front lens group and the rear lens group coincident with each other in order to improve the accuracy of the photographed image. A structure that can surely match is desired.

[0004]

An object of the present invention is to provide a supporting device for a front lens group of a zoom lens, which is capable of easily matching the optical axes of the front lens group and the rear lens group and ensuring the optical position accuracy of both based on the above-mentioned awareness. It is intended to be provided.

[0005]

SUMMARY OF THE INVENTION The present invention is a movement capable of moving back and forth in the optical axis direction.
Inside the lens barrel, the front lens group that holds the front lens group and the rear lens group
A zoom lens that supports the rear lens barrel that holds the lens.
Lens unit is fixed inside the movable lens barrel,
Rear group support tube for supporting the movable back and forth in the axial direction;
Separated in the optical axis direction between the inner peripheral surface and the inner peripheral surface of the rear group support cylinder.
Each has a circular center hole centered on the optical axis.
Front first inward flange and rear second inward flange; front
A first lens formed on each of a front end portion and a rear end portion of the group lens barrel;
A first fitting portion that fits into the inner flange and a second inner flange
A second fitting portion that fits into the circular center hole of the socket; and a first fitting portion
A fixing mechanism for fixing the first portion and the first inner flange;
Fitting relationship between the first fitting portion and the first inner flange and the second fitting
The front group lens barrel moves due to the fitting relationship between the first part and the second flange.
It is characterized in that a coaxial relationship between the lens barrel and the rear lens group barrel is secured .

Fixing mechanism for the first fitting portion and the first inward flange
On the side of the first inward flange, separated from the inside in the circumferential direction.
A plurality of engaging claws formed by projecting in the radial direction are provided, and
On the side of the fitting part, the plurality of engaging claws are immovably engaged.
The mating engagement recesses and the engagement claws in the circumferential direction from the engagement recesses.
The circumferential groove portion that can be detached, and the engagement with the circumferential groove portion.
Provide a small-diameter insertion part that allows the jaws to be inserted and removed in the optical axis direction.
You can In addition, the first fitting part and the first inward flange
The front group lens is clamped and moved by the restoring force to the moving lens barrel.
The cylinder is pressed in the optical axis direction to engage the engagement claw and the engagement recess.
Provide an annular elastic member centered on the optical axis to maintain
Good. For example, set the circumferential groove that allows the engagement claw to pass through the optical axis.
It is formed as an annular groove that serves as the center, and the annular elastic
It is good to store members.

The annular elastic member is the first inner flange.
It also functions as a waterproofing means that liquid-tightly closes between the
Preferably.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described below based on the illustrated embodiments. In this embodiment, the present invention is applied to the lens shutter zoom lens camera shown in FIG. 19. First, the concept of this zoom lens camera will be described with reference to FIG. This camera is provided with a three-stage extension type zoom lens barrel 10 including a first extension lens barrel (lens support barrel) 20, a second extension lens barrel 19 and a third extension lens barrel 16. ing. The lens structure of the zoom lens barrel 10 includes a front lens group L1 and a rear lens group L1.
There are two groups of two.

The camera main body has a whole movement motor control means 60, a rear group movement motor control means 61, and a zoom operation means 6.
2, a shutter release means 63, a distance measuring device 64, a photometric device 65, and an AE motor control means 66 are provided.

When the zoom operating means 62 such as the zoom operating lever and the zoom operating button provided on the camera body is operated, the overall moving motor control means 60 operates the overall moving motor 25.
On the other hand, a movement command for moving the zoom lens including the front lens group L1 and the rear lens group L2 from the wide side to the tele side or a movement command for moving from the tele side to the wide side is given. The focal length is changed and set to an arbitrary focal length by the operation of the zoom operating means 62 by the photographer. The image magnification of the finder field of the zoom finder 67 provided in the camera is changed in association with the change of the focal length by the zoom operation means 62. Therefore, the photographer can know the change in the focal length due to the operation of the zoom operation means 62 by observing the change in the image magnification of the viewfinder field. The focal length set by the operation of the zoom operation means 62 is, for example, an LCD display panel (not shown).
It can be recognized by the numerical value displayed on.

The overall movement motor control means 60 is also driven by the rear group movement motor control means 61 when the shutter release means 63 is operated.
At the same time, the whole movement motor 25 is driven to focus the zoom lens on the subject. The shutter release means 63 is
It is composed of a release button, and when it is pressed one step, it gives a distance measurement command to the distance measurement device 64 and a photometry command to the photometry device 65, and when it is pressed two steps, the focus operation is performed and the AE motor control means 66 is operated. AF / AE shutter unit 2 via
The first shutter 27 is operated. The shutter 27 receives the photometric output from the photometric device 65 and receives the photometric output from the shutter blade 2
7a is opened for a predetermined time.

When operated, the zoom operating means 62 drives the whole moving motor 25 to move the front lens group L1 and the rear lens group L2 integrally. The rear lens group moving motor 30 may be operated via the rear lens group moving motor control means 61 at the same time as this movement, but an important point in this zoom lens camera is that the front lens group L1 and the rear lens group lens by the zoom operation means 62 are operated. It means that the movement of L2 is not performed in the conventional zooming concept in which the focal length is continuously changed without moving the focal position. That is, when the zoom operation means 62 is operated, only the whole movement motor 25 is operated to move the front lens group L.
1 and the rear lens group L2 are moved back and forth without changing the air gap between them, and both the overall movement motor 25 and the rear lens group movement motor 30 are operated to operate the front lens group L1 and the rear lens group L2. It is possible to move while changing the air gap between the two.

In the aspect, the subject at a specific distance cannot always be in focus. However, in the lens shutter type camera such as the present camera which does not observe the image by the photographing optical system, the subject is focused during the shutter release. There is no problem at all as it fits. Further, in the mode, while allowing the movement of the focal position, the front lens group L1 and the rear lens group L2 are moved, and both the overall movement motor 25 and the rear group movement motor 30 are operated at the time of shutter release to focus. .

After executing any one of the above control modes in accordance with the operation of the zoom operating means 62, the shutter release means 63 is operated in the focal length range of at least a part of the focal length set by the zoom operating means 62. Then, the whole moving motor 25 and the rear group moving motor 30
Both are operated to focus on the subject. The amount of movement of the front lens group L1 and the rear lens group L2 by the overall movement motor 25 and the rear group movement motor 30 at this time is not limited to the movement amount obtained from the subject distance information by the distance measuring device 64, and
It is determined in consideration of the movement amount obtained by the focal length information set by the zoom operation means 62. As described above, when the shutter release means 63 is operated, if the whole movement motor 25 and the rear group movement motor 30 are operated to perform the focusing operation, the degree of freedom in controlling the lens position is increased, and the control is performed. Will be easier.

Theoretically, when the zoom operating means 62 is operated, the whole moving motor 25 and the rear group moving motor 30 are operated.
When the shutter release means 63 is operated, only the field of view magnification and the focal length information of the zoom finder 67 are changed without operating any of the above. It is also possible to simultaneously operate the moving motor 25 and the rear lens group moving motor 30 to move the front lens group L1 and the rear lens group L2 to positions uniquely determined by the focal length information and the subject distance information.

Next, mainly using FIGS. 1, 2 and 5,
An embodiment in which the zoom lens barrel having the above concept is concretely described will be described. The schematic configuration and operation of the zoom lens barrel 10 will be described first. First, the first movable barrel 20,
The second movable lens barrel 19, the third movable lens barrel 16, and the fixed lens barrel block 12 are provided. The third movable lens barrel 16 is screwed into the tubular portion 12p of the fixed lens barrel block 12, and advances and retreats in the optical axis direction as it rotates. The third movable lens barrel 16 moves integrally in the optical axis direction, and has a rotation restricted linear guide barrel 1.
7 is provided inside, and the second movable lens barrel 19 is the linear guide barrel 1
It moves forward and backward in the optical axis direction while rotating with respect to 7. The rotation of the first movable lens barrel 20 is restricted, and the second movable lens barrel 19 is
It moves back and forth in the optical axis direction by rotating with respect to. The whole movement motor 25 is fixed to the fixed lens barrel block 12,
The shutter mount (rear group lens support member) 40 on which the E motor 29 and the rear group movement motor 30 are mounted is the first movable lens barrel 2
It is fixed at 0. The front lens group L1 is a lens having a positive power supported by a front lens group support cylinder (front lens group cylinder) 34, and the rear lens group L2 is a negative power supported by a rear lens group support cylinder 50. Is a lens having.

The fixed lens barrel block 12 fixed in front of the aperture plate 14 of the camera body has a cylindrical portion 12p.
A female helicoid 12a and a plurality of linear guide grooves 12b parallel to the optical axis O are provided on the inner peripheral surface of the. The straight guide groove 12b ', which is one of the plurality of straight guide grooves 12b, has a code plate 13 having a predetermined code pattern at the bottom thereof.
a is fixed. The code plate 13a is configured as a part of the flexible printed board 13 located outside the fixed lens barrel block 12. Aperture plate 14
Is an aperture 14a that determines the exposure area on the film.
Have.

On the cylindrical portion 12p of the fixed lens barrel block 12, there is formed a gear accommodating portion 12c which bulges radially outward and extends in the optical axis direction (see FIG. 15). A drive pinion 15 which is long in the optical axis direction is rotatably stored in the gear storage portion 12c. Both ends of the shaft 7 of the drive pinion 15 are rotatably supported by the support hole 4 provided in the fixed lens barrel block 12 and the support hole 31a provided in the gear support plate 31, respectively. The tooth surface of the drive pinion 15 protrudes inward from the inner peripheral surface of the tubular portion 12p of the fixed lens barrel block 12.

A third movable lens barrel 16 is screwed onto the inner circumference of the tubular portion 12p of the fixed lens barrel block 12. This third
The movable lens barrel 16 has a plurality of straight guide grooves 16c extending in the optical axis direction on the inner peripheral surface, and a male helicoid 16a meshing with the female helicoid 12a of the tubular portion 12p on the outer periphery of the rear end portion.
It has an outer peripheral gear 16b (see FIG. 13) which meshes with the drive pinion 15. The drive pinion 15 has the outer gear 1 in the entire movement range of the third movable lens barrel 16 in the optical axis direction.
6 has an axial length that meshes with 6.

On the inner circumference of the third movable lens barrel 16, a linear guide barrel 17 is supported so as to be movable integrally with the third movable lens barrel 16 in the optical axis direction and relatively rotatable around the optical axis. . The linear guide cylinder 17 has a rear end flange portion 17d provided on the outer periphery of the rear portion with a plurality of engagement protrusions 17c protruding outward in the radial direction,
A retaining flange portion 1 having a smaller diameter than the flange portion 17d, which is provided in front of the rear end flange portion 17d with a slight gap.
7e and. A circumferential groove 17g extending in the circumferential direction about the optical axis O is formed between the retaining flange portion 17e and the rear end flange portion 17d (FIG. 14).
reference). A plurality of cutout portions 17f are formed in the circumferential direction of the retaining flange portion 17e. Third movable lens barrel 16
Has a plurality of engagement protrusions 16d (see FIGS. 1 and 2) projecting radially inward on the inner circumference of the rear end portion.
Each of d is inserted from the corresponding cutout portion 17f and positioned in the circumferential groove 17g between the flange portions 17d and 17e, and is rotated by a predetermined amount with respect to the linear guide cylinder 17 to be coupled with the linear guide cylinder 17. There is. On the rear end surface of the straight guide tube 17,
An aperture plate 23 having an opening 23a having substantially the same shape as the aperture 14a is fixed. The engagement protrusion 17c is slidably engaged with the linear guide groove 12b parallel to the optical axis O of the cylindrical portion 12p, and its rotation is restricted. Engagement protrusion 1
The engaging plate 17c ', which is one of the 7c, has a cord plate 13
A contact terminal 9 for generating a signal corresponding to the focal length during zooming by being in sliding contact with a is fixed.

The straight guide tube 17 also has an inner peripheral surface,
A plurality of straight guide grooves 17a parallel to the optical axis O and a plurality of lead grooves 17b penetrating the peripheral wall of the straight guide cylinder 17 and inclined with respect to the circumferential direction and the optical axis direction are formed.

A second movable lens barrel 19 is fitted on the inner circumference of the linear guide barrel 17. The second movable lens barrel 19 has a plurality of lead grooves 19 on the inner peripheral surface thereof, the lead grooves 19 having an inclination opposite to that of the lead grooves 17b.
c has a plurality of follower protrusions 19a having a trapezoidal cross-section, and a follower pin 18 located on the follower protrusions 19a. The follower pin 18 includes a ring member 18a and a center fixing screw 18b that supports the ring member 18a on the follower protrusion 19a. The follower protrusion 19a is
Slidably fitted in the lead groove 17b of the straight guide cylinder 17,
The follower pin 18 is the linear guide groove 1 of the third movable lens barrel 16.
6c is slidably fitted. Therefore, when the third movable lens barrel 16 rotates, the second movable lens barrel 19 rotates and moves straight in the optical axis direction.

The first movable lens barrel 20 is fitted on the inner circumference of the second movable lens barrel 19. The first movable lens barrel 20 engages a plurality of follower pins 24 provided on the outer periphery of the rear end portion with the corresponding inner peripheral lead grooves 19c, and the linear guide member 22.
Directed by. This linear guide member 22 is
As shown in FIGS. 9 and 10, an annular portion 22a and a pair of guide leg portions 22b extending from the annular portion 22a in the optical axis direction.
And a plurality of engaging projections 28 that are slidably engaged with the rectilinear guide groove 17a and project outward in the radial direction of the annular portion 22a, and the inner peripheral surface of the first movable lens barrel 20 and the AF The pair of guide leg portions 22b are inserted in a pair of linear guide portions 40c formed between the / AE shutter units 21 so as to be linearly guided.

The annular portion 22a of the linear guide member 22 is
The second movable lens barrel 19 is coupled to the rear end of the second movable lens barrel 19 so as to be movable in the optical axis direction and rotatable relative to the optical axis. The straight guide member 22 has a rear end flange portion 22d provided with a plurality of engagement protrusions 28 projecting radially outward on the outer periphery of the rear portion.
And a retaining flange portion 22c having a diameter smaller than that of the flange portion 22d, which is provided in front of the rear end flange portion 22d with a slight gap. A circumferential groove 22f extending circumferentially around the optical axis O is formed between the retaining flange portion 22c and the rear end flange portion 22d. The retaining flange 22c includes a plurality of notches 22 in the circumferential direction.
e (see FIG. 9). The second movable lens barrel 19 has a plurality of engagement projections 19 that project radially inward on the inner circumference of the rear end portion.
b (FIG. 1), each of the engaging protrusions 19b is inserted from the corresponding notch 22e to insert both flanges 22c, 2
It is located in the circumferential groove 22f between the 2d and the linear guide member 22.
On the other hand, the linear guide member 22 is connected by rotating a predetermined amount. With the above configuration, the first movable lens barrel 20 is
When the second movable lens barrel 19 rotates in the forward and reverse directions, the second movable lens barrel 19 moves straight forward and backward with respect to the second movable lens barrel 19 while its rotation is restricted.

A barrier device 35 having barriers 48a and 48b is attached to the front end of the first movable lens barrel 20,
The AF / AE shutter unit 2 provided with a shutter 27 including three shutter blades 27a (FIG. 8) on the inner peripheral surface.
1 (FIGS. 3 and 4) are fitted and fixed. This AF / A
The E shutter unit 21 has a plurality of fixing holes 40a formed at equal angular intervals on the outer peripheral portion of the shutter mount 40. The plurality of follower pins 24 are connected to the AF / AE
It also serves as a fixing means for the shutter unit 21, and a pin hole 20 a formed in the first movable lens barrel 20 and the fixing hole 40.
The follower pin 24 is fitted and fixed to a, and the shutter unit 21 is fixed to the first movable lens barrel 20 (see FIG. 12). Reference numeral 41 is a decorative plate fixed to the front end of the first movable lens barrel 20.

The AF / AE shutter unit 21 includes a shutter mount 4 as shown in FIGS. 3, 4 and 8.
0, a shutter blade support ring 46 fixed to the rear portion of the shutter mount 40, and a rear lens group support barrel 50 movably supported with respect to the shutter mount 40. The shutter mount 40 supports the front lens group support cylinder 34, the AE motor 29, and the rear lens group moving motor 30. This shutter mount 40 is used for the first movable lens barrel 2
A flange-shaped annular portion 40f facing inward of 0 and three leg portions 40 extending rearward from the annular portion 40f.
and a shutter mounting cylinder having a substantially cylindrical shape. Two of the gaps between the three leg portions 40b are configured as the pair of straight guide portions 40c for slidably engaging the pair of guide leg portions 22b of the straight guide member 22 and guiding the movement. There is.

The shutter mount 40 further has an AE gear train 45 that transmits the rotation of the AE motor 29 to the shutter 27.
And the rotation of the rear group movement motor 30 to the screw shaft 4
Lens drive gear train 42 to be transmitted to the photoconductor 3, and photointerrupters 56 and 57 connected to the flexible printed circuit board 6.
And rotating plates 58, 5 having a large number of slits in the circumferential direction.
9 and 9 are supported. The photo interrupter 57 and the rotary plate 59 constitute an encoder for the rear group moving motor that detects the rotation of the rear group moving motor 30, and the photo interrupter 56 and the rotary plate 58 constitute the AE motor 29.
The encoder for the AE motor that detects the rotation of the is configured. The position of the rear lens group L2 with respect to the front lens group L1 in the optical axis direction is detected based on the detection result of the rear group movement motor encoder, and the aperture diameter of the aperture of the shutter 27 is detected based on the detection result of the AE motor encoder. To be done.

The shutter 2 is provided between the shutter mount 40 and the shutter blade support ring 46 fixed to the mount 40.
7, a support member 47 that pivotally supports the three shutter blades 27a of the shutter 27, and an annular drive member 49 that applies rotational force to the shutter blades 27a. The annular drive member 49 is provided with three operation protrusions 49a that engage with the three shutter blades 27a at equal angular intervals. The shutter blade support ring 46 is provided on the front wall portion with the photographing opening 4
6a and three support holes 46b provided at equal angular intervals around the photographing opening 46a, and the straight guide portion 4 is provided on the outer peripheral portion.
It has a bending restriction surface 46c exposed from 0c and slidably supporting the inner peripheral surfaces of the pair of guide leg portions 22b (see FIGS. 17 and 18).

The support member 47 located in front of the shutter blade support ring 46 includes a photographing opening 47a facing the photographing opening 46a, and three shaft portions 47b facing the three supporting holes 46b (see FIG. 8). Only shown). Each of the three shutter blades 27a has, at one end, a shaft hole 27b through which the shaft portion 47b is inserted, and at the other end, a shielding portion that shields the photographing openings 46a and 47a,
Between the one end and the other end, there is an elongated hole 27c through which the operation protrusion 49a is inserted. The support member 47 includes shafts 47b that respectively support the shutter blades 27a.
The shutter blade support ring 46 is fixed to the corresponding shutter hole support ring 46 in a state of being fitted into the corresponding support hole 46b.

The annular drive member 49 has a gear train 4 on its outer peripheral portion.
It has a gear portion 49b that receives rotation from 5. Further, the support member 47 has three circular arc grooves 47c along the circumferential direction at positions close to the three shaft portions 47b. The three operation protrusions 49a of the annular drive member 49 penetrate the three arcuate grooves 47c to form the elongated holes 27 of each shutter blade 27a.
c is engaged. The shutter blade support ring 46 is inserted from the rear side of the shutter mount 40 while supporting the annular drive member 49, the support member 47 and the shutter 27, and is screwed to the shutter mount 40.

Behind the shutter blade support ring 46, a slide shaft (guide rod) 5 is attached to the shutter mount 40.
A rear lens group support cylinder 50 is disposed so as to be movably supported via the lenses 1 and 52. Slide shafts 51, 52
The rear end portions of the above are respectively fitted to shaft support bosses 50b and 50c which are provided to project on the outer peripheral surface of the rear lens group support cylinder 50. The shutter mount 40 and the rear lens group support cylinder 50 are
The coil springs 3 fitted to the slide shaft 51 are urged to move away from each other, thereby eliminating play between the two. Further, the gear train 42
The drive gear 42a included in the drive gear 42a is sandwiched between the support ring portion 53a formed on the pressing member 53 and the shutter mount 40, and its movement in the axial direction is restricted. A female screw is formed on the inner circumference of the drive gear 42a. There is. A male screw 43b of the screw shaft 43 is screwed into the female screw, and the drive gear 42a and the screw shaft 43 form a feed screw mechanism. The rear end portion of the screw shaft 43 is fitted to a shaft support boss 50a protruding from the outer peripheral surface of the rear lens group support cylinder 50. Therefore, when the rear group moving motor 30 is rotationally driven to rotate the drive gear 42a in either forward or reverse directions, the screw shaft 43 advances or retracts with respect to the drive gear 42a, and the rear group lens support cylinder 50, that is, the rear group lens support. The rear lens group L2 supported by the barrel 50 moves with respect to the front lens group L1.

Pressing members 53 and 55 for pressing the motors 29 and 30 supported by the shutter mount 40 are screwed to the front of the shutter mount 40. Motors 29 and 30 and photo interrupters 56 and 57 are connected to the flexible printed circuit board 6 whose one end is fixed to the shutter mount 40. In a state where the first to third movable lens barrels 20, 19, 16 and the AF / AE shutter unit 21 are assembled, the aperture plate 23 is fixed to the rear end surface of the linear guide barrel 17, and the barrel of the fixed lens barrel block 12 is fixed. An annular retaining member 3 is provided at the front end of the groove 12p.
3 is fitted.

In this embodiment, the rear lens group L2 is set to the AF
/ AE shutter unit 21 as one of the constituent members, and the unit 21 includes an AE motor 29 and a rear group movement motor 30.
It is equipped with. According to this configuration, there is an advantage that the supporting structure and the driving structure of the front lens group L1 and the rear lens group L2 can be simplified, but the rear lens group L2 can be replaced by the shutter mount 40, the annular driving member 49, the supporting member 47, Shutter 2
The present zoom lens can be realized even when the AF / AE shutter unit 21 including the shutter blade pressing ring 46 and the like 7 is provided as a separate member and is supported by a support member different from the unit.

In the present zoom lens barrel 10, the front lens group support tube 34 supporting the front lens group L1 is firstly provided for the purpose of realizing waterproofness of the zoom lens, rationalization of the shutter unit structure, effective use of space, and the like. The rear lens group L2 is fixed to the movable lens barrel 20 by a bayonet method, and the rear lens group L2 is configured to be hung on the main body side of the AF / AE shutter unit 21, and is disposed between the front lens group support cylinder 34 and the first movable lens barrel 20. In addition, an O-ring, which is a biasing means and a waterproofing means, is interposed.
In such a structure, in order to secure the optical position accuracy of the front lens group L1 with respect to the rear lens group L2, in the present zoom lens barrel 10, only between the front lens group support barrel 34 and the first movable lens barrel 20. Not this front lens group support tube 34
And a shutter mounting base 40 on which the shutter 27 having the AE function is mounted.

Below, the front lens group L1 and the rear lens group L2
A front lens group supporting device for easily obtaining the positional accuracy with respect to will be described. As shown in FIG. 1, the first movable lens barrel (moving lens barrel) 20 is formed on the inner peripheral side of the front portion, and is integrally formed with the lens barrel 20.
A substantially circular center hole 20e (FIG. 7,
It has an inner flange (first inner flange) 20b having a structure shown in FIG. The center hole 20e regulates radial movement of the front portion of the fitted front lens group support barrel 34, and determines the position of the front lens group L1 with respect to the first movable lens barrel 20 mainly in the radial direction. Three engaging claws 20c are formed on the inner peripheral edge of the inner flange 20b at equal angular intervals. The engaging claws 20c are the front lens group support cylinder 3
After being inserted into the circumferential groove portion (circumferential groove portion) 34g from the notch 4 (small diameter insertion portion) 34f (see FIG. 6), the front lens group supporting cylinder 34 is rotated by a predetermined amount with respect to the first movable lens barrel 20. By doing so, it engages with the engaging hook portion (engagement concave portion) 34h. Center hole 2 at the inner peripheral edge of the inner flange 20b
An annular portion 20d for sandwiching an O-ring (annular elastic member) 81 with the outer flange 34j of the front lens group supporting cylinder 34 is formed in the front portion of 0e.

The follower pin 2 is provided on the inner surface of the first movable lens barrel 20.
AF / AE shutter unit 2 fixed via 4
1 is one of the members that make up the shutter mount ( rear group support)
The holding cylinder ) 40 has an annular portion (second inner flange) 40f,
It has a substantially circular center hole 40d into which the rear part of the front lens group support cylinder 34 is fitted. The center hole 40d restricts the radial movement of the rear portion of the fitted front lens group support barrel 34,
The optical position of the front lens group L1 with respect to the rear lens group L2 supported by both the first movable lens barrel 20 and the shutter mount 40 is determined mainly in the radial direction.

The front lens group support barrel 34 is fitted in the center hole 20e of the first movable lens barrel 20 in the front thereof.
An annular fitting portion (first fitting portion) 34 having a diameter slightly smaller than 0e
have e. The front lens group support tube 34 is also fitted to the center hole 40d of the shutter mount 40 behind the front lens group support tube 34,
An annular fitting portion (second fitting portion) 34a having a diameter slightly smaller than the center hole 40d is provided, and between the fitting portions 34e and 34a, the diameter of the AE motor 29 or the like is smaller than the fitting portion 34e. It has an insertion portion 34c that is inserted inward. At the rear end of the front lens group support tube 34, the front lens group L fitted inward is attached.
An inner flange 34b is formed so as to abut the rear surface of the first. The fitting portion 34a is the inner surface 29a of the AE motor 29.
In order to fit the center hole 40d located on the inner peripheral side,
It has a smaller diameter than the insertion portion 34c. The front lens group support cylinder 34 has an annular groove portion 34g into which the O-ring 81 is fitted, and an outer flange 34j having a diameter larger than that of the fitting portion 34e in this order on the front side of the fitting portion 34e. Further, the fitting portion 34e is formed with notches 34f that engage with the three engaging claws 20c at equal angular intervals, and engaging hook portions 34h that are respectively adjacent to the three notches 34f. . The O-ring 81 urges the outer flange 34j to move forward from the inner flange 20b in the direction of the optical axis to maintain the engagement state between the engagement hook portion 34h and the engagement claw 20c, and The watertightness between the first movable lens barrel 20 and the front lens group support barrel 34 is maintained to make them waterproof.

The front lens group support cylinder 34 also includes a fitting portion 34.
e, an internal thread portion 34i is provided on the inner peripheral side of the outer flange 34g and the like. A male screw portion 80a of a lens holding ring 80 for fixing the front lens group L1 fitted to the front lens group supporting cylinder 34 to the front lens group supporting cylinder 34 is screwed into the female screw portion 34i. The lens pressing ring 80 has an annular contact surface 80b that comes into contact with the peripheral portion of the front surface of the front lens group L1 in substantially surface contact. A waterproof coating material is applied to the annular contact surface 80b to improve the waterproof performance between the front lens group support cylinder 34 and the front lens group L1.

In the present zoom lens barrel 10 having the front lens group supporting device having such a structure, the assembling work of the front lens group L1 and the like can be carried out as follows. First, on the shutter mount 40 on which the annular drive member 49, the support member 47, the shutter 27, the shutter blade pressing ring 46, etc. are mounted,
The rear group lens support cylinder 50, which fixes the rear group lens L2 so as to have a predetermined positional relationship with the center hole 40d, is supported by A
The F / AE shutter unit 21 is assembled. And
This AF / AE shutter unit 21 is attached to the first movable lens barrel 2
The follower pin 24 that is inserted inward from the pin 0 and is inserted into the fixing hole 40a provided in the shutter mount 40 from the pin hole 20a.
Is fitted and fixed, and the shutter mount 40 is fixed to the first movable lens barrel 20 so as to have a predetermined positional relationship with respect to the movable lens barrel 20. The follower pin 24 is, for example, an adhesive,
It can be fixed by means such as screwing.

Thereafter, the front lens group L1 is fitted inside the front lens group support cylinder 34, and the lens retaining ring 80 is screwed into the female screw portion 34i to fix the lens L1. The O-ring 81 is fitted into the annular groove 34g of the support cylinder 34. The front lens group supporting cylinder 34 in this state is inserted from the rear side thereof into the center hole 20e, and the fitting portion 3 having the smallest diameter is inserted.
4a is moved toward the center hole 40d. Then, when the rear fitting portion 34a enters the center hole 40d, the notch 34f engages with the corresponding engaging claw 20c, and the front fitting portion 34e fits into the center hole 20e.

In this state, the front lens group support cylinder 34
Is rotated in the clockwise direction in FIG. 6 while holding the front end portion and pushing it toward the inner flange 20b. And 3
If the front lens group support cylinder 34 is released at the time when the engaging hooks 34h at the respective positions are engaged with the three engagement claws 20c, the O-ring 81 elastically contacting the annular portion 20d will light the front lens group support cylinder 34. Push back on the axis. Therefore, the fitting portion 34e
The engaging hook portion 3 in a state in which is fitted in the central hole 20e.
4h strongly engages with the engaging claw 20c. As a result, the front lens group support barrel 34 is accurately positioned in a predetermined positional relationship with respect to the first movable lens barrel 20 and the shutter mount 40, and the front lens group L2 is supported by the shutter mount 40 with respect to the rear lens group L2. Since the position of L1 particularly in the radial direction is easily determined, the optical axes of the front group lens L1 and the rear group lens L2 are aligned. As described above, according to the supporting device for the front group lens, the optical axes of the front group lens L1 and the rear group lens L2 can be easily aligned with each other, and the optical position accuracy of both can be secured.

The present zoom lens camera operates as follows. FIG. 1, in which the zoom lens barrel 10 is most retracted.
When the power switch (not shown) is turned on in the lens housed state shown in FIGS. 2 and 17, the whole movement motor 25 is driven to rotate a little in the forward direction. Then, this rotation is transmitted to the drive pinion 15 via the gear train 26 supported by the support portion 32 formed on the fixed lens barrel block 12, and the third movable lens barrel 16 is rotated in the payout direction. Second
The movable lens barrel 19 and the first movable lens barrel 20 are the third movable lens barrel 16 and
At the same time, it is slightly extended in the optical axis direction, and the camera is ready for shooting with the zoom lens positioned at the wide end.

When the zoom operation means 62 is operated to the tele side in this photographing possible state, the whole movement motor 25 is rotationally driven in the positive direction via the whole movement motor control means 60, and the driving pinion 15 and the outer peripheral gear 16b are used. The third movable lens barrel 16 is rotated in the feeding direction. Therefore,
The third moving lens barrel 16 is extended from the cylindrical portion 12p of the fixed lens barrel block 12 due to the relationship between the female helicoid 12a and the male helicoid 16a, and at the same time, the linear guide tube 17 is provided with the engaging projection 17c and the linear guide groove 12b. Due to the relationship, the third movable lens barrel 16 and the third movable lens barrel 16 advance to the front side of the optical axis without rotating with respect to the fixed lens barrel block 12. At this time, the second movable lens barrel 19 causes the follower pin 18 to engage with the lead groove 17b and the rectilinear guide groove 16c at the same time.
While moving in the same direction as the movable lens barrel 16, it moves forward of the optical axis with respect to the movable lens barrel 16. Also, the first movable lens barrel 20 is
Since the follower pin 24 is guided straight by the straight guide member 22 and the follower pin 24 is moved and guided by the lead groove 19c, the follower pin 24 does not rotate with respect to the fixed barrel block 12,
From the second movable lens barrel 19 to the AF / AE shutter unit 21
Along with the optical axis.

Since the rear lens group moving motor 30 is not driven while the zoom lens barrel 10 is driven in this way, the front lens group L1 and the rear lens group L2 are integrally integrated with each other while keeping a constant distance from each other. In the direction (see FIG. 16). The focal length set by the zoom operation means 62 is displayed by the display means (not shown).

When the release button is pushed one step (half depressed) at an arbitrary focal length set by the zoom operating means 62, a distance measuring command is given to the distance measuring device 64 and a light measuring command is given to the light measuring device 65. , Distance measurement and photometry are started. After that, when the release button is pressed twice (fully pressed), both the total movement motor 25 and the rear group movement motor 30 are moved by the zoom operation means 62 and the movement amount obtained by the object distance information from the distance measuring device 64. The front lens group L1 and the rear lens group L2 are moved by a movement amount determined in consideration of the movement amount obtained by the set focal length information to set the focal length and focus on the subject, and the AE motor AE motor 29 via control means 66
However, the annular driving member 49 is rotationally driven according to the subject brightness information from the photometric device 65, and the shutter 27 is driven so as to satisfy a predetermined exposure. After completion of the shutter release, both the whole movement motor 25 and the rear group movement motor 30 are immediately driven to return the front group lens L1 and the rear group lens L2 to the state before the shutter release.

When the zoom operating means 62 is operated to the wide side, the whole moving motor 25 is rotationally driven in the reverse direction, and
The movable lens barrel 16 is rotated in the retracting direction and retracted into the fixed lens barrel block 12 together with the linear guide barrel 17. At the same time, the second movable lens barrel 19 is retracted with respect to the movable movable lens barrel 16 while rotating in the same direction as the third movable lens barrel 16.
The movable lens barrel 20 has a position A relative to the rotating second movable lens barrel 19.
It is pulled in together with the F / AE shutter unit 21.
Even during this feeding drive, the rear group movement motor 30 is not driven, as in the feeding drive described above. When the power switch is turned off, the zoom lens barrel 10 is retracted to the lens storage position shown in FIGS. 1 and 2 by the entire moving motor 25 that is rotationally driven based on the power switch.

[0047]

As is apparent from the above description , the present invention
According to this, it is possible to provide a supporting device for a front lens group of a zoom lens, in which the optical axes of the front lens group and the rear lens group can be easily aligned with each other and optical position accuracy can be ensured.

According to the invention of claims 2 to 4,
While waterproofing the space between the movable lens barrel and the front lens barrel,
And the front lens barrel can be fixed easily and securely
It

[0049]

[Brief description of drawings]

FIG. 1 is an upper half sectional view showing a lens housed state of a zoom lens barrel to which the present invention has been applied.

FIG. 2 is an upper half cross-sectional view showing the lens housing state of the zoom lens barrel in partially different cross sections.

FIG. 3 is a perspective view showing an AF / AE shutter unit of the zoom lens barrel.

FIG. 4 is a perspective view showing a state of the same AF / AE shutter unit different from that in FIG.

5 is an exploded perspective view showing the entire zoom lens barrel shown in FIG. 1. FIG.

FIG. 6 is an enlarged perspective view showing a front lens group support barrel of the zoom lens barrel.

FIG. 7 is a perspective view showing a main part of the zoom lens barrel.

FIG. 8 is an exploded perspective view showing main members of an AF / AE shutter unit of the zoom lens barrel.

FIG. 9 is a perspective view showing a main part of a straight-ahead guide mechanism of the zoom lens barrel.

FIG. 10 is a perspective view showing a state of a main part of the straight-movement guide structure different from that in FIG. 9;

FIG. 11 is a perspective view showing a main part of the zoom lens barrel in the present embodiment.

FIG. 12 is a perspective view showing a state where the AF / AE shutter unit of the zoom lens barrel is assembled to the first moving barrel.

FIG. 13 is a perspective external view showing a third movable lens barrel of the zoom lens barrel.

FIG. 14 is a perspective external view showing a straight guide tube of the zoom lens barrel.

FIG. 15 is a front view showing a fixed lens barrel block of the zoom lens barrel.

FIG. 16 is an upper half sectional view showing a maximum extended state of the zoom lens barrel.

FIG. 17 is an upper half cross-sectional view showing a main part of the zoom lens barrel in a lens housed state.

FIG. 18 is an upper half sectional view showing a main part of the zoom lens barrel in the maximum extended state.

FIG. 19 is a block diagram showing a control system for controlling the operation of the zoom lens barrel.

[Explanation of symbols]

10 zoom lens barrel 20 first movable barrel ( moving barrel ) 20b inner flange (first inner flange) 20d annular pressure contact portion 20e center hole (circular center hole) 21 AF / AE shutter unit 25 overall movement motor 29 AE motor 30 Rear group movement motor 34 Front group lens support cylinder (front group lens cylinder) 34a Fitting part (second fitting part) 34e Fitting part (first fitting part) 34c Insertion part 34g Annular groove part (circumference) Directional groove) 34j Outer flange 40 Shutter mount ( rear group support cylinder ) 40d Center hole (circular center hole) 40f Annular part (second inner flange) 51 52 Slide shaft (guide rod) 61 Rear group movement motor control means 62 zoom operating means (zooming switch) 81 O-ring (annular elastic member) L1 front lens group L2 rear lens group O optical axis

Continuation of front page (56) Reference JP-A-5-11310 (JP, A) JP-A-6-289271 (JP, A) JP-A-7-27963 (JP, A) JP-A-4-157408 (JP , A) Actual Kai 3-110426 (JP, U) Actual Kai 60-76311 (JP, U) Actual Kai 5-4116 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB) Name) G02B 7/02-7/105

Claims (9)

(57) [Claims] 1. A movable lens barrel that can move back and forth in the optical axis direction,
Holds the front lens group that holds the front lens group and the rear lens group.
For the zoom lens that supports the rear lens barrel that you have
Is fixed in the movable lens barrel and moves the rear lens barrel back and forth in the optical axis direction.
A rear group support tube that movably supports; an optical axis direction on the inner peripheral surface of the movable lens barrel and the inner peripheral surface of the rear group support tube.
Separated circular centers centered on the optical axis
A first inward flange on the front and a second inward flange on the rear with holes
Lunge; formed on the front end and the rear end of the front lens barrel, respectively
The first fitting portion fitted to the first inner flange, and the second fitting portion
A second fitting portion that fits in the circular center hole of the inner flange; and
A fixing mechanism for fixing the first fitting portion and the first inner flange; and a fitting relationship between the first fitting portion and the first inner flange and a second fitting.
The front group lens barrel moves due to the fitting relationship between the first part and the second flange.
Make sure that the coaxial relationship between the lens barrel and the rear lens barrel is ensured.
Supporting device for the front lens group of the characteristic zoom lens. 2. The support device according to claim 1, wherein:
The fixing mechanism is arranged on the first inward flange so as to be spaced in the circumferential direction and project in the inner diameter direction.
A plurality of engaging claws formed by being extended; and formed on the first fitting portion
, The plurality of engaging claws are immovably engaged with each other.
Engagement recess and engagement claw can be detached from the engagement recess in the circumferential direction
And the engaging claws to the circumferential groove portion.
A small-diameter insertion part that can be inserted and removed in the direction of the optical axis; and is sandwiched between the first fitting part and the first inner flange.
It is held and the front lens group barrel is moved against the moving barrel by the restoring force.
Press in the optical axis direction to maintain the engagement between the engaging claw and the engaging recess.
A supporting device for a front lens group of a zoom lens, which has an annular elastic member having an optical axis as a center . 3. The support device according to claim 2, wherein:
The circumferential groove part has an optical axis formed on the outer peripheral surface of the first fitting part.
An annular groove serving as a core, and the annular elastic member is provided in the annular groove.
Support device for the front lens group of the zoom lens housed . 4.請Motomeko 2 or 3 supporting device smell according
And the annular elastic member includes a first inner flange and a first inner flange.
A support device for a front lens group of a zoom lens, which doubles as a waterproof means for liquid-tightly closing a space between fitting parts . 5. The support device according to claim 1, wherein the rear group lens is supported by a guide rod projecting rearward from the rear group support cylinder , and the rear group support is provided.
A supporting device for a front lens group of a zoom lens, in which a rear lens group driving motor for moving the rear lens group to and from the rear lens group supporting cylinder is provided on the holding cylinder . 6. The method according to any one of claims 1 to 5.
In the supporting device of FIG.
Supporting device for the front lens group of the zoom lens whose mechanism is fixed . 7. The supporting device according to claim 1, wherein the entire movable lens barrel is moved in the optical axis direction.
A support device for the front lens group of a zoom lens , which has an entire movement motor for moving the camera body . 8. The method according to any one of claims 1 to 7.
In this support device, the movable lens barrel is used for zooming and
A support device for the front lens group of the zoom lens that is moved along the optical axis when the shutter is released . 9. The support device according to claim 8, wherein the rear group
When the shutter is released, the lens barrel does not
A support device for the front lens group of a zoom lens that is moved in the axial direction .