JP3401232B2 - Lens barrel - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lens barrel, and more particularly to a lens barrel having a guide member for moving a frame member in the optical axis direction of the lens.

[0002]

2. Description of the Related Art In recent years, cameras with zoom lenses have tended to be miniaturized and have high precision, and various types of advancing and retracting mechanisms for zooming, focusing, etc. of lens barrels in these cameras have been proposed. ing. In particular, as one of the advancing / retreating mechanisms in the case of a small camera, there is a structure having a movable lens holding frame, and the lens holding frame is guided straight by a straight rod which is a rod-shaped guide member.

For example, as disclosed in Japanese Patent Laid-Open No. 64-11212, a support shaft (rod) is fixed to a lens holding frame that is moved by a helicoid screw, and another lens holding frame can be moved on this support shaft. I try to support it.

Further, as disclosed in JP-A-57-150807, a rod as a guide member generally provided in the lens barrel is fixedly arranged inside the lens barrel or inside the lens barrel. It is movably arranged.

[0005]

However, when the frame member moves on the rod fixed to the fixed frame or the like, the rod must be lengthened and provided, and it is necessary to secure a space particularly in design. It will be inconvenient. Further, even if two moving frames are moved by using a helicoid screw or the like, there is a limitation in the way of moving them, and the same inconvenience occurs. For example, when a helicoid is used, its moving frame can only move linearly, or the overlapping portions on the optical axis cannot be moved.

A lens barrel having a structure in which a rod is fixed inside the lens barrel as disclosed in JP-A-57-150807 described above naturally has a length (size) of the rod. Will depend on the length of. Further, even if the rod fixed to the moving frame can move together with the moving frame, the length of the lens barrel must be equal to or longer than the length of the rod, and in any case, the size of the lens barrel can be reduced. It was blocking.

Therefore, an object of the present invention is to eliminate the above-mentioned drawbacks of the prior art, and to use a guide member (guide rod) skillfully to freely move the frame member with a simple structure. To provide a lens barrel that can.

[0008]

In order to achieve the above-mentioned object, the first lens barrel of the present invention is a lens barrel having a photographic lens which can be shortened, and is provided in the lens barrel. is, having a movable frame having a rod member as linear guide member, the can <br/> and the lens barrel is shortened, the outer peripheral surface of the rod member from the outside rear surface of the photographing lens characterized that you have protruded.

The second lens barrel of the present invention is a lens barrel having a taking lens that can be moved to the stored state, and a moving frame provided in the lens barrel and having a rod member as a linear guide member. the a, when the photographing lens is shifted in the storage state, the outer peripheral surface of the rod member <br/> is characterized that you have to protrude to the outside from the outside rear surface of the photographing lens.

A third lens barrel of the present invention is characterized in that, in the first or second lens barrel, the photographing lens is a zoom lens.

Further, a fourth lens barrel of the present invention is characterized in that, in the first or second lens barrel, the moving frame is a lens holding frame for holding a lens.

Further, a fifth lens barrel of the present invention is characterized in that, in the first or second lens barrel, the lens barrel is mounted on a mirror box having a reflection mirror.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the examples shown in the drawings. 1, FIG. 2 and FIG. 3 are an exploded perspective view and a longitudinal sectional view in a collapsed state of a lens barrel showing an embodiment of the present invention, respectively.

This zoom lens barrel enables zooming, focusing and collapsing operations. The main structure of this zoom lens barrel is a fixed frame 1
A fixed lens frame 2 fixed to the fixed frame 1, a focus ring 3, an inner zoom ring 4, an outer zoom ring 5, a first group frame 6 which is a focusing lens group frame, and a focusing lens. A first moving frame 7 that holds a second group lens that is a lens group frame, a second moving frame 8 that is a lens group frame other than a focusing lens and that holds a third group lens, and a fourth group Another moving frame 9 for holding the lens, a fifth group lens holding frame 10, and first, second, third, and third members respectively held directly or indirectly by the respective frames.
The fourth and fifth lens groups 20, 21, 22, 23 and 24 (see FIG. 3), the focus drive unit 11 , the zoom drive unit 12, the aperture unit 13 and the zoom encoder section are included. In addition, each lens group 20
˜24 are not shown in FIGS. 1 and 2, but are shown in the sectional view of FIG. 3, respectively.

The fixed frame 1 is fixed to a mirror box 16 of the camera body via spacers 14 and 15. The spacers 14 and 15 adjust the distance between the fixed frame 1 and the mirror frame 17 mounted on the mirror box 16 for holding the movable reflection mirror 19 as shown in FIG. Further, the fixed frame 1 has a hole 1a for supporting the fifth group lens frame 10 in the center thereof, and a fitting portion 1d for fitting the fixed lens frame 2 integrally with the mounting flange portion.
Further, it has a cylindrical portion 1e for rotatably supporting the inner zoom ring 4 around the optical axis O, and the sliding pin 1g for restricting the movement of the inner zoom ring 4 in the optical axis direction is fixed by the screw 1f. It is fixed on the cylindrical portion 1e.

Further, the fixed frame 1 is provided with a fitting hole portion 1b and a fitting elongated hole 1c for slidably supporting the second group main rod 7e and the second group sub rod 7f in the optical axis direction. . Further, the focus drive unit 11 is attached to an attachment surface 1h provided by cutting out a part of the cylindrical portion 1e. The zooming drive unit 12 is also attached to the fixed frame 1 in the same manner. Furthermore, aperture unit 1
The charge lever 25 for operating 3 is also pivotally attached to the fixed frame 1 through its shaft hole 25a.

The fixed lens frame 2 has a cylindrical shape and is fixed to the fitting portion 1d of the fixed frame 1 with its inner peripheral portion 2a fitted. The first group frame 6 is provided along the optical axis O in the cylindrical portion.
And the guide linear grooves 2b and 2c of the first moving frame 7, and
The focus ring 3 along the circumferential direction of the inner circumference of the fixed frame 1 side
2g has a bottomed inner peripheral groove for axial position regulation of the contact point 1 along the peripheral direction of the cylindrical portion opposite to the fixed frame side.
3 are provided with elongated holes 2d for axial position regulation. As shown in the development view of FIG. 15, the straight groove 2c has a groove portion 2h in the zoom region having a width equal to the outer diameter of the roller 7j to be fitted, and a width larger than the outer diameter. It should be formed from the groove portion 2i in the collapsed region. The groove 2i is a portion used when the lens barrel is collapsed.

The focus ring 3 has a ring shape, the outer periphery of which is fitted to the inner periphery 2a of the fixed lens frame 2, and the inner periphery of which is engaged with the output gear 11a of the focus drive unit 11 . A tooth gear 3e is provided. Further, the sliding pin 3b is attached to the pin fixing portion on the outer peripheral portion.
Are fixed by screws 3a. The sliding pin 3b is slidably fitted in the inner circumferential groove 2g of the fixed lens frame 2 and prohibits the movement of the main focus ring 3 in the optical axis O direction. Further, a sliding pin 3d for moving the zoom ring 5 in the optical axis direction is fixed to a pin fixing portion 3g on the protrusion that is loosely fitted to the inner circumference of the outer zoom ring 5 with a screw 3c. The sliding pin 3d is slidably fitted in the focus cam groove 5b of the zoom ring 5.

The inner zoom ring 4 is a cylindrical member, the inner peripheral portion of which is rotatably fitted to the cylindrical portion 1e of the fixed frame 1, and the inner peripheral groove 4d provided on the inner peripheral portion thereof. The sliding pin 1g of the fixed frame 1 is fitted in the lock frame 4, and the movement of the main zoom ring 4 in the optical axis direction is prohibited. The zoom drive unit 1 driven based on the zoom control signal is provided on the inner peripheral portion.
An internal gear 4c with which the two output gears 12a mesh is provided.

Further, the zoom ring 4 has a second moving frame 8 for holding the third and fourth lens groups, and cam grooves 4a, 4 serving as a first cam means for zooming driving another moving frame 9.
b is provided. Then, sliding pins 8j and 9f fixed to the second moving frame 8 and another moving frame 9 are fitted into the cam grooves 4a and 4b, and the cam shape is shown in the development view of FIG. As shown, the cam groove portions 4g in the collapsible region corresponding to the collapsible state of the lens frame having no displacement in the optical axis direction,
4h and cam grooves 4i and 4j in the zoom area having a zoom displacement in the optical axis direction. A roller 4f, which is a connecting member fitted in the straight-moving groove 5a of the outer zoom ring 5, is rotatably supported by a pin 4e on the outer peripheral portion thereof.

The outer zoom ring 5 is a cylindrical member, and its outer peripheral portion and inner peripheral portion are fitted into the fixed lens frame 2 and the first group frame 6 so as to be rotatable or slidable, respectively. Then, the straight groove 5a is provided along the optical axis O,
The inner zoom ring 4 is rotationally driven in accordance with the zoom amount via a roller 4f fitted in the groove.
Further, since the main zoom ring 5 is provided with the focus cam groove 5b corresponding to the focusing extension amount and the sliding pin 3d of the focus ring 3 is fitted therein, the main zoom ring 5 moves straight in the optical axis direction by the focusing amount. Can be moved.

Further, the zoom ring 5 is provided with cam grooves 5c and 5d which are second cam means. Then, in the cam grooves 5c and 5d, the first and second group rollers 6b and 7j supported by the first group frame 6 and the first moving frame 7 are provided.
Is inserted. Therefore, the first group frame 6 and the first moving frame 7 are displaced in the optical axis O direction according to the turning of the main zoom ring 5 due to zooming or the axial movement due to focusing. In addition, the cam grooves 5c, 5
d is for moving the cam portions 5i and 5h in the zoom area which give driving positions during focusing and zooming, and the first group frame 6 or the first moving frame 7 to the retracted position when the camera is not used, that is, It is formed of cam portions 5j and 5g in the collapsed region for retracting to the camera body side. The groove width of the cam portion 5g is the width of the roller 7 to be inserted.
It is formed to be larger than the outer diameter dimension of j so that interference between the lens groups does not occur during the retraction (see FIG. 15).

The zoom ring 5 is provided with a stepped square hole 5f for guiding a contact piece base 13 for a zoom encoder, which will be described later, at a position corresponding to the elongated hole 2d of the fixed lens frame 2. There is.

The first group frame 6 is one to which the first group lens holding frame 6c is screwed and has a cylindrical shape. The outer peripheral portion is slidably fitted into the outer zoom ring 5. The first group roller 6b is rotatably attached to the corresponding portion 6f of the cam groove 5c on the outer peripheral portion by a pin 6a. The first group roller 6b has the cam groove 5
c and the straight groove 2b of the fixed lens frame 2 are also fitted.
Therefore, the first group frame 6 is guided by the rectilinear groove 2 in the optical axis O direction, and is moved in accordance with the rotation or the rectilinear movement of the zoom ring 5. A concave portion 6e that forms a thin portion is provided on the inner circumference of the first group frame 6 along the axial direction. The concave portion 6e serves as a relief portion for the second group driving plate 7h described later.

The first group lens 20 is held by the first group lens holding frame 6c, the lens interval is adjusted by the spacer 6d, and is supported by the first group frame 6.

The first moving frame 7 holds the second group lens frame 7a to which the second group lens 21 is attached. Then, as shown in FIG. 4, in order to fix and support the rod, which is a rod-shaped guide member, two U-shaped notches 7b are provided on the outer shape portion so as to face the optical axis of the lens frame. There is. The surface formed by the two sides 7c of the notch is formed by molding or machining so as to be parallel to the optical axis of the lens frame. The second group main rod 7 which is a rod-shaped guide member is provided in the cutout portion 7b.
e or one end of the second group sub rod 7f is inserted, and the rod 7e, 7f is fixed by pressure contact with the inclined surface of the fixing piece 7 through the screw 7g using the dogleg shaped fixing piece 7. Since each rod is pressed by the inclined surface of the fixed piece 7, the rods 7e and 7f respectively have the cutout portion 7b.
The two sides 7c are brought into contact with each other, and as a result, they are mounted parallel to the optical axis of the lens frame.

The mounted rods 7e and 7f
The other ends of the fitting frame 1 are the fitting hole 1b of the fixed frame 1 and the fitting long hole 1
It is slidably inserted into c. Therefore, the second group lens 21
The first moving frame 7 to which is attached can be slid forward and backward along the optical axis O without rotating. A second moving frame 8 of another lens holding frame is slidably supported and guided by the rods 7e and 7f.

A second group drive plate 7h for driving the first moving frame 7 in the axial direction and extending in the optical axis direction is fixed by screws. And this drive plate 7h
A roller 7j is rotatably attached to the tip of the roller via a pin 7i. Further, the roller 7j is fitted into the cam groove 5c of the outer zoom ring 5 and the rectilinear groove 2c of the fixed lens frame 2 as described above. Therefore, as the outer zoom ring 5 rotates and moves in the axial direction, the first moving frame 7 moves in the optical axis O direction via the drive plate 7h, and the second group lens 21 also moves in the same manner. To be The drive plate 7h
Due to the arrangement, the concave portion 6e provided in the first group frame 6
It is located in the space part of.

The second moving frame 8 holds the third lens group 22, and the second group main rod 7e is fixed to the first moving frame 7 in a pair position with respect to the optical axis. And it is slidably supported by the sub rod 7f in the optical axis direction. That is, the rod 7e is fitted into the cutout portion 8c of the second moving frame 8, while the sub rod 7f is fitted into the moving frame via the sleeve 8a into which the sub rod 7f fits as shown in the mounting state diagram of FIG. Support 8. The sleeve 8a is fixed to the moving frame 8 with an adhesive H, but the outer diameter of the sleeve itself has a dimension such that it is loosely fitted in the mounting hole 8b of the moving frame 8.

In order to perform the above-mentioned bonding, first, the convex fitting portion 7k of the first moving frame 7 which is formed concentrically with the optical axis, respectively.
And the concave fitting portion 8d of the second moving frame 8 are fitted to each other. At that time, the rod 7e is inserted into the notch 8c and the rod 8e.
The sleeve 8a is fitted in the f and is inserted into the mounting hole 8b. Then, the adhesive H is caused to flow into the gap between the sleeve 8a and the hole 8b for adhesion. In this way, the second moving frame 8 and the third group lens 22 are correctly mounted concentrically with respect to the center of the optical axis and do not rotate but are parallel to the optical axis direction.
Moreover, it is possible to slide back and forth without backlash. It is assumed that a compression spring 18 for removing play in both frames is inserted in the rod 7f between the second moving frame 8 and the first moving frame 7.

Further, the second moving frame 8 is provided with two third group rods 8h and a sub rod 8k for slidably supporting another moving frame 9 described later in the optical axis O direction. ing. The sub rod 8k is planted and fixed to the second moving frame 8 in a state parallel to the optical axis O. The hole 8r to be planted
Has been drilled with high precision such as hole diameter and parallelism by machining or molding. Then, the rod 8k is pressed into the hole 8r to be planted. The sub rod 8k and the rod 8
It is assumed that h is disposed so as to substantially face the optical axis O (see FIG. 6). On the other hand, the rod 8h is supported by the second moving frame 8 and the arm 8e provided on the frame as shown in FIG. 5, and the mounting holes 8g and 8f are loosely fitted to the rod 8h. The fixing is done by gluing. Prior to the bonding, the sleeve 9c loosely fitted to the other moving frame 9 is bonded and fixed.

That is, the sleeve 9c which is loosely fitted in the through hole 9b provided in the sliding arm portion 9a of the movable frame 9 is inserted, and the sleeve is slid with respect to the optical axis of the frame 9 by using a mechanical jig. Hold so that the inner diameters of 9c are parallel. Adhesive H in that state
The sleeve 9c is fixed to the hole 9b by. And
The rod 8h is fitted into the sleeve 9c and penetrates it, and is further inserted into the holes 8f and 8g which are the loose fitting holes of the arm 8e. The rod 8h has an E-shaped retaining ring 8m attached to the end thereof for preventing the positional displacement before the bonding.

Subsequently, the convex fitting portion 9g of the other moving frame 9 provided concentrically with the optical axis is replaced with the concave fitting portion 8p of the second moving frame 8 provided concentrically with the optical axis. To fit
At the same time, the sub rod 8k is fitted into the notch 9d of the moving frame 9. In this way, the optical axes of the moving frames 8 and 9 are made to coincide with each other, and further the direction of the rod 8h is made to coincide with each other,
The rod 8h and the holes 8g and 8f of the moving frame 8 are adhered and fixed by the adhesive H. The third and fourth group lenses 22, 23 held by the movable frames 8, 9 are concentrically attached to the optical axis O and can be moved in parallel.

On the pin mounting portion 8s of the second moving frame 8, a sliding pin 8j fitted in a cam groove 4a provided on the inner zoom ring 4 is fixed by a screw 8i, so that the zoom ring 4 Of the moving frame 8 causes the optical axis O to move.
You can move back and forth in the direction.

A diaphragm unit 13 is mounted on the surface of the second moving frame 8 on the object side. Then, by the charge lever 25 pivotally attached to the fixed frame 1,
A diaphragm operation of the diaphragm unit 13 is performed via the charged lever 13a. Since the charged lever 13a is a member long in the optical axis direction, even if the moving frame 8 moves in the optical axis direction, the engagement with the charge lever 25 does not come off. Further, since the diaphragm unit 13 has a photo interrupter and an electromagnet device for adjusting the diaphragm, it must be electrically connected to the camera side. Therefore, this unit 13 is provided with a flexible substrate 13b for diaphragm connection.

The other moving frame 9 holds the fourth group lens 23, and as described above, the second moving frame 8 is held.
The two rods 8h and 8k are slidably supported in the optical axis direction. The rod 8h is supported via the sleeve 9c. A sliding pin 9f fitted in a cam groove 4b provided on the inner zoom ring 4 is fixed to the sliding arm portion 9a of the other moving frame 9 with a screw 9e. By the rotation, the moving frame 9 is moved back and forth in the optical axis O direction.

The fifth-group lens holding frame 10 holds the fifth-group lens 24. To mount the fifth-group lens holding frame 10, first, the outer periphery 10a of the fifth-group lens holding frame 10 is fitted into the fitting hole 1a of the fixed frame, so that the lens light Align the optical axis O with the axis. The fixing portion 10b of the holding frame 10 is attached to the fixing frame 1 with screws or the like for positioning in the optical axis direction.

The zoom encoder section detects the rotation angle of the outer zoom ring 5 or the inner zoom ring 4 about the optical axis, and as shown in FIG.
The contact piece 13d fixed to the contact piece base 13 and sliding on the conduction pattern of the encoder board 14, and the encoder board 1
4 and a metal plate 14a for protecting the substrate 14. The contact piece base 13 has protrusions 13c on both sides,
Both side surfaces have edge projections 13a having a slight height in the direction of the contact piece 13d. Then, the outer zoom ring 5 is inserted into the stepped square hole 5f portion having the step portion 5k, and the back surface of the edge 13b of the contact piece base 13 is brought into contact with the step portion 5k of the square hole 5f to be mounted. The square hole 5f has such a size that the fitting surface 5e of the zoom ring 5 in the rotation direction fits with the edge portion 13b of the contact piece base 13 without a gap, and the axial length is the contact piece. It is set to be larger than the width of the edge protrusion 13a of the base 13 plus the maximum movement amount of the zoom ring 5 in the axial direction.

The elongated hole 2d of the fixed lens frame 2 is located above the square hole 5f, and the width of the elongated hole 2d in the rotational direction is relative to the movement of the contact piece base 13 in the circumferential direction. The width of the outer zoom ring 5 is allowed to rotate, and the width of the fitting width portion 2e in the axial direction is a fitting dimension with which the edge projection 13a of the contact piece base 13 or both side surfaces can slide. To do. Therefore, the contact piece base 13 can move over the elongated hole 2d in accordance with the rotation angle of the contact piece base 13 in the entire axial movement of the outer zoom ring 5. Since the contact piece 13d slides on the encoder board 14 arranged along the elongated hole 2d and moves in the rotation direction, the rotation angle of zooming of the zoom ring 5 can be detected. In the encoder part, the contact piece base 13 has the protrusion 13c and the elongated hole 2d.
Since it is pressed down by the edge of the width portion 2e, the contact piece base 13 has a structure that does not easily come off from the square hole 5f.

The focus drive unit 11 will be described with reference to FIGS. FIG. 8 shows the above unit 1
1 is a perspective view of the outer appearance of FIG. 1 , and FIG. 9 is a perspective view seen from the back side thereof. Further, FIG. 10 is a view showing a YY cross section of FIG. The unit 11 constitutes a unit case 20, a focus driving motor 21, a motor output gear 21b that is an output gear fixed to the motor output shaft 21a, and a reduction gear train, and the gear 21b. Gear, sun gear, planetary gear, unit output gear 11a, unit case stop plate 31, drive unit rotation detector, and flexible printed circuit board 11s for electrical connection to the motor 20 and PI 23. It is configured. The unit 11 is mounted on the mounting surface 1h at a portion where the cylindrical portion 1e of the fixed frame 1 is cut out, as described above.
It is assumed that the motor 21, the reduction gear train, the case 20, the case stop plate 31, and the like are arranged along the curvature of the cylindrical portion 1e (see FIG. 11).

The rotation detecting section comprises a slit plate 22 and a PI 23 which is a photo interrupter. Then, the PI 23 is fixed to the unit case 20 with a screw through a slide plate 23a having lubricity. And
The slit plate 22 that gives an input signal to the PI 23 by its rotation is a gear 2 that meshes with the motor output gear 21b.
It is formed integrally with 2a and is rotatably fitted in the shaft portion 20a of the case 20. Then, the slide plate 23 acts as a retainer in the axial direction of the gear 22a.

In the power transmission path by the reduction gear train between the motor output gear 21b and the unit output gear 11a, first, the motor output rotation is via the gear 22a meshing with the gear 21b and the gear 2 having the sun gear portion 24b.
4 is transmitted. Then, the rotation of the sun gear portion 24b is transmitted to the three planetary gears 25 meshing with it. The planetary gear 25 is rotatably supported by a shaft portion provided integrally with a support body of the sun gear 28 so that the planetary gear 25 is prevented from coming off in the axial direction. Then, it meshes with an internal gear 20d provided on the inner wall of the case 20. Therefore, the planetary gear 25 rotates and revolves by the rotation of the sun gear portion 24b, and the sun gear 28 rotates by the rotation. Hereinafter, the rotation is transmitted to the planetary gear 26 that meshes with the sun gear 28 and the sun gear 29 that is rotated by the gear, and further to the planetary gear 27 that meshes with the sun gear 29 and the gear 30 that is rotated by the gear. Further, the gear 30 meshes with the unit output gear 11a, which is the final stage, and the rotational output decelerated by the output gear 11a is obtained.

The gear 24, the gear 30, and the output gear 11a are pivotally supported by shaft portions 20b, 20c, 20d formed integrally with the unit case 20, respectively. Further, for the sun gears 28 and 29, the three planetary gears 26 of the respective three planetary gears 26 are used without using a supporting shaft portion.
Alternatively, it is held at the axial center position by the engagement of 27. Also,
Axial direction is held and rotated by abutting each end face. The gears 30 and 11a are case 2
A unit case stopper plate 31 for positioning and holding the inside of 0 is attached. The case stopper plate 31 is attached to the case by engaging the two locking claws 31b with the seat portion of the mounting hole 20e of the case 20 using elasticity.

As shown in FIGS. 2 and 10, the unit 11 is attached to the lens barrel by bringing the case stopper plate 31 side into contact with the mounting surface 1h of the fixed frame 1 and fixing its positioning dowel 31a. The main unit 11 is inserted into the hole of the frame 1 and screwed to the mounting screw portion 20e to fix the main unit 11 to the lens barrel. Then, the internal gear 3e of the focus ring 3, which is a driven member rotatably supported by the fixed frame 1, and the unit output gear 11a are engaged with each other to bring the unit into a focus drivable state. The output shaft 21a to which the motor output gear 21b of the motor 21 is fixed extends in the M direction parallel to the optical axis direction, and the transmission path of the series of reduction gear trains meshing with the gear 21b is the above-mentioned. It is transmitted in the N direction opposite to the M direction. Then, the rotational output is taken out from the unit output gear 11a located on the mounting surface side.

As shown in FIGS. 8 and 9, the printed circuit board 11s for electrical connection has guide pieces 20g, 2 in which the board portion 11s connected to the PI 23 is integrated with the case 20.
It is hung on 0h and 20i. The substrate 11
The L-shaped portion 11t at the tip of s is for preventing the guide piece 20i from coming off (see FIG. 8).

FIG. 12 is a sectional view taken along line XX of FIG.
It shows a vertical cross section of the mounted state of the unit 11 ,
On the inner diameter side of the curvature of the unit case 20 facing the optical path side, there is a light shielding surface 20f having a triangular groove cross section with a small pitch to shield unnecessary light outside the light flux L. Also, printed circuit board 1
It is assumed that 1 s is bent into an S shape and guided to the rear surface side of the fixed frame 1.

The zooming, focusing, and collapsing operations of the zoom lens barrel of the present embodiment having the above structure will be described. In the following description, the rotation direction is designated by the rotation direction viewed from the subject side.
FIG. 3 shows a state in which the lens barrel is collapsed, in which the first group frame 6 and the first moving frame 7 are collapsed, and the second group main rod 7e is projected to the rear of the fixed frame. Has become. First, the zooming operation from this state to the long focus side will be described.

FIG. 13 shows the extended position from the wide end to the tele end of each lens group, and the first group up to the extended position by the zoom drive unit 12 based on a zoom instruction from a system controller (not shown). ~ Move the fourth lens group. That is, the inner zoom ring 4 is rotated clockwise through the output gear 12a of the drive unit 12. Along with the rotation, the sliding pins 8j and 9f move into the cam groove 4.
Among the a and 4b, the grooves 4g and 4h in the retracted area are located in the grooves 4i and 4j in the zoom area (see FIG. 14). Then, the second moving frame 8 to which the pins are fixed and the other moving frame 9 move, and the third and fourth lens groups 22,
23 is extended to each zoom position. On the other hand, the outer zoom ring 5 also rotates in the same direction via the roller 4f supported by the inner zoom ring 4. Due to the rotation, the rollers 6b and 7j are moved from the groove portions 5j and 5g in the retracted area to the groove portions 5i and 5h in the zoom area of the cam grooves 5c and 5d (FIG. 15).
(See (A)). At the same time, since the rollers 6b and 7j are also fitted in the straight-moving grooves 2b and 2c of the fixed lens frame 2, the rollers 6b and 7j can be moved straight toward the object. It should be noted that, in the straight-moving groove 2c, the straight-moving groove 2i in the zoom region is changed from the groove 2i in the retractable region.
shift to h. Further, since the sliding pin 3d, which is not moved during zoom driving, is fitted into the focus cam groove 5b of the outer zoom ring 5, the outer zoom ring 5 itself moves by the action of this cam toward the object side. Just move. Therefore, the movement amount of the first group frame 6 or the first moving frame 7 to which the rollers 6b and 7j are directly or indirectly fixed by zooming is driven by the cam grooves 5c and 5d of the outer zoom ring 5. The movement amount is the sum of the movement amount and the focus correction amount driven by the focus cam groove 5b. In the above description of the zoom movement amount, the case of zoom drive to the long focus side is shown, but the zoom drive to the short focus side can be performed by driving the inner zoom ring counterclockwise. This operation is the reverse operation of the above zoom drive.

In detecting the zoom state associated with the above zoom drive, the rotation of the outer zoom ring 5 is detected by the zoom encoder section. The operation will be described with reference to FIGS. Contact piece 1 in which the conductive pattern on the attached encoder board 14 is supported by the contact piece base 13.
3d is brought into sliding contact to take out a coded signal relating to the zoom position. As described above, the contact piece base 13 is inserted into the square hole 5f of the outer zoom ring 5 only in a circumferentially fitted state, and further in the axial direction into the width portion 2e of the elongated hole 2d of the fixed lens frame 2. Since they are fitted, the contact piece 13d slides on the conduction pattern as the zoom ring 5 rotates. The zoom ring 5 also moves in the axial direction. In that case,
Since the hole width of the square hole 5f in the axial direction is larger than that of the contact piece base 13, the edge projection 13a of the contact piece base 13 has the fixed lens frame 2
Guided by the width portion 2e of the elongated hole 2d, the contact piece 13d slides on the encoder substrate 14 to output a zoom position detection signal.

Next, regarding the focusing operation, the operation in the case of focusing from a state corresponding to the ∞ distance (infinity distance) of the subject to a predetermined subject distance will be described. The focus drive unit 11 is driven based on the focus instruction from the system controller, and the focus ring 3 is rotated counterclockwise via the unit output gear 11a. With the rotation, the focus cam groove 5b of the outer zoom ring 5 is moved to the sliding pin 3d of the focus ring 3.
Slides, the zoom ring 5 moves toward the subject.
In this case, since the inner zoom ring 4 is stationary, the outer zoom ring 5 moves straight. And the rollers 6b and 7j
Move the first group frame 6 or the first moving frame 7 via
First group lens 20 and second group lens 2 which are focusing lens groups
1 is extended toward the subject. The focusing operation from a short distance to a long distance of the object is performed by driving the focus ring 3 in the opposite direction.

Next, referring to FIGS. 2 and 15 , the operation of retracting the lens frame at the end of photographing in the zoom lens barrel of this embodiment will be described.
It will be explained by (A) and (B). First, the focus drive unit 11 is driven to rotate the focus ring 3 clockwise to retract the first and second lens groups to the infinity in-focus position toward the camera body.

Subsequently, the zoom drive unit 12 is driven to rotate the inner zoom ring 4 counterclockwise, but the rotation angle thereof is further rotated counterclockwise from the phase in the zooming short focus state. Rotate to the phase. as a result,
The sliding pins 8j and 9f fitted in the cam grooves 4a and 4b of the inner zoom ring 4 are located in the cam grooves 4g and 4h, which are the retractable regions.

At the same time, the outer zoom ring 5 also rotates by the same rotation angle as the zoom ring 4. Then, as shown in FIG. 15B, the rollers 6b and 7j are connected to the cam groove 5 of the zoom ring 5.
It is located in the cam grooves 5g, 5j in the collapsing regions of c, 5d. Therefore, the first group frame 6 and the first moving frame 7 are retracted to the retracted position retracted further toward the camera body than the position corresponding to the ∞ distance. As described above, when the first group frame 6 retracts to the retracted position, the first moving frame 7 must move to a position outside the normal zoom range, and the first group lens holding frame 6c and the first group lens Interference with 20 or clogging occurs. Therefore, the rectilinear groove 2i and the cam groove 5g in the collapsible region are formed into a loosely fitting shape with respect to the roller 7j fitted therein, so that the above interference is avoided and the collapsing can be surely performed.

Next, a modified example of the fixing structure of the main rod 7e and the sub rod 7f for supporting the frame on the first moving frame 7 will be described with reference to FIGS. In this modification, the U-shaped notch shape for fixing the rods 7e, 7f is different from that of the above-described embodiment.

In FIG. 16, a rod 57 having good straightness is provided.
The cutout portion 57b for holding e and 57f is arranged on the outer peripheral portion of the first moving frame 57 so as to substantially face the optical axis of the moving frame. The cutout portion 57b is formed by the rod 57.
Side contact surface 57 parallel to the optical axis with which e and 57f contact
c and bottom contact surfaces 57k and 57m. The cylindrical outer diameter surfaces 57k and 57m, which are the bottom contact surfaces, utilize the cylindrical portion provided on the moving frame 7. And the cylindrical outer diameter surface 5
7k and 57m are concentric with the optical axis and have the same outer diameter. The portion between the bottom contact surfaces 57k and 57m is a surface 57n recessed from the contact surface.

Then, each rod is fixed by the rod 57.
Insert e and 57f into the above notch,
The inclined surfaces of the tip of 7d are connected to rods 57e and 57f, respectively.
It is located on the upper side and is fixed by pressing with a screw 57g. Since the portion between the bottom contact surfaces 57k, 57m is recessed as described above, the rods 57e, 57f more reliably contact the side contact surfaces 57c, bottom contact surfaces 57k, 57m. Be touched. Therefore, according to this modification, the rod supporting the lens moving frame can be fixed with high accuracy in parallel to the optical axis of the frame.

As another modified example of the fixing structure of the rods 7e and 7f, it is possible to propose one using a V-shaped notch groove for the U-shaped notch fixing groove of the above-mentioned embodiment. Is. In this modification, the V-shaped cutout groove is provided on the outer periphery of the lens moving frame so as to substantially face the optical axis, and the cutout groove is also parallel to the optical axis. Then, the rods 7e and 7f are brought into contact with and attached to the cutout grooves, and fixed to the holding frame by a flat plate-shaped fixing plate. The rod fixed in this way is also supported in parallel with the optical axis with high precision, but the V-shaped notch is easy to obtain the precision of parallelism in machining or molding, so the rod is fixed with higher precision. Is possible.

As described above, in the zoom lens barrel of this embodiment, the zoom ring is divided into two frames, an inner frame and an outer frame.
By rotating or driving the outer zoom rings 4 and 5 straight, the zooming operation, that is, the focal length is changed. Further, the outer zoom ring 5 is driven straight forward to move only the focusing lens group forward and backward to perform the focusing operation. According to this embodiment, since the inner and outer zoom rings 4 and 5 are arranged so as to overlap each other, the total length of the lens barrel can be further shortened.

The main rod 7e and the sub rod 7f, which are rod-shaped guide members for sliding the first moving frame 7 in the zoom lens barrel of this embodiment, are fixed to the moving frame 7 by fixing them. The U-shaped cutout portion 7b having two contact surfaces parallel to the optical axis is pressed and fixed. If the notch is formed with high precision by machining or molding the contact surface, the rod can be more accurately fixed to and supported by the moving frame as compared with the conventional method such as press fitting. Further, since the above structure fixes the rod to the outer peripheral portion of the frame, it can be applied to a small lens frame.

Further, the second moving frame 8 in the present embodiment.
The sleeve 8a into which the sliding support rod 7f is fitted is fixed by adhesion. That is, the first moving frame 7
In order to align the optical axes of both the moving frame 8 and the moving frame 8, the sleeve 8a loosely fitted in the moving frame 8 is held while the concentric fitting portions are fitted in the respective optical axes. The sleeve 7a is slidably fitted into the rod 7f which is fixedly supported by 7, and the loosely fitted sleeve 8a is fixed to the moving frame 8 by adhesion in this state. Therefore, it is possible to maintain the positional accuracy of each member at the time of bonding, and in particular, it is possible to assemble with higher positional accuracy between the holding frames without increasing the component accuracy of each member itself. .

Further, to the third group lens holding frame 8 which is the second moving holding frame of the rod 8h which is the guide member of the moving frame 9 which holds the fourth group lens in the zoom lens barrel of the present embodiment. Is fixed by gluing. That is, in order to make the optical axes of both frames coincide with each other, the fitting portions that are concentric with the respective optical axes are held, and the rod 8h fitted into the moving frame 9 is loosely fitted into the moving frame 8. It is inserted and the rod 8h is adhered to the moving frame 8 in this state.

Since the sleeve 8a is fixed in this manner, the positional accuracy of each member at the time of bonding can be maintained, and in particular, the holding accuracy can be improved without increasing the fitting accuracy of each member. It becomes possible to assemble the positional accuracy between the frames.

In order to store the focus drive unit 11 of the zoom lens barrel of this embodiment efficiently, the focus drive unit 11 is arranged in a part of the donut-shaped space in the barrel, and its outer shape is the cylindrical portion of the lens frame. A corresponding predetermined curvature is given, and the motor and the reduction gear train are arranged according to the curvature.
Further, the output shaft center of the motor and the shaft center of the reduction gear train are connected to the optical axis O.
It is arranged so that it is parallel to. Then, for the convenience of driving the focus ring 3, the output gear 2 of the motor
1b and a unit output gear 11a for extracting the rotational output of the drive unit are located on the motor mounting side, which is the side on which the internal gear 3e of the focus ring 3 of the driven portion is located. Therefore, the extension direction of the motor output shaft to which the motor output gear 21b is fixed is opposite to that of the driven part side, and the extension of the shaft part of the reduction gear train to which the unit output gear 11a is attached is located in front thereof. By making the direction opposite to the extending direction described above, a more efficient drive system path can be obtained. Main drive unit configured in this way
Reference numeral 11 makes it possible to efficiently use the storage space of the lens barrel, and there is no need to unnecessarily increase the diameter of the lens barrel.

[0064]

As described above, according to the present invention, the rod member as the guide member is provided on the moving frame (lens holding frame), and the rod expands and contracts as it moves. Since it is configured, the difference in the expansion and contraction direction when stretched and when it is contracted is great, giving more freedom in designing the lens frame and exhibiting a special effect that it can be stored compactly when not shooting. To do.

[Brief description of drawings]

FIG. 1 is an exploded perspective view of a zoom lens barrel showing an embodiment of the present invention,

FIG. 2 is an exploded perspective view of a zoom lens barrel showing an embodiment of the present invention,

FIG. 3 is a vertical cross-sectional view of the lens barrel of the zoom lens barrel of FIGS. 1 and 2 in a retracted state,

FIG. 4 is a view on arrow A of FIG.

FIG. 5 is a diagram showing a rod fixed state of each lens holding frame of the zoom lens barrel of FIGS. 1 and 2;

6 is a sectional view taken along the line BB in FIG. 1,

7 is a development view of a zoom encoder section of the zoom lens barrel of FIG. 2,

8 is a perspective view of a focus drive unit mounted on the zoom lens barrel of FIG. 1,

9 is a perspective view of a focus drive unit mounted on the zoom lens barrel of FIG. 1;

10 is a sectional view taken along the line YY in FIG.

11 is a diagram showing a state in which the focus driving unit of the zoom lens barrel of FIG. 1 is mounted on a fixed frame;

12 is a sectional view taken along line XX in FIG.

FIG. 13 is a diagram showing the extended position of each lens group in zoom drive of the zoom lens barrel in FIG. 3;

14 is a development view of a cam groove of an inner zoom ring of the zoom lens barrel of FIG. 2,

FIG. 15 (A) is a view of the zoom lens barrel of FIG.
FIG. 2B is a development view of the outer zoom ring when zooming, FIG. 2B is a development view of the inner zoom ring of the zoom lens barrel shown in FIG.

16 is a vertical cross-sectional view showing a rod fixing state of a first moving frame of a modified example of the rod fixing structure of the first moving frame of the zoom lens barrel of FIGS. 1 and 2;

FIG. 17 is a perspective view showing a rod fixed state of the first moving frame of the modified example of FIG. 16;

[Explanation of symbols]

7 ... First moving frame (lens holding frame, frame member) 7f, 7e ......... Guide member 8 ... Second moving frame (lens holding frame, frame member) 8h, 8k ... Guide member 9: Another moving frame (another holding frame)

─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A 64-11212 (JP, A) Actual Opening 2-35109 (JP, U) Actual Opening 62-99021 (JP, U) Actual Opening 60- 13511 (JP, U) (58) Fields surveyed (Int.Cl. ⁷ , DB name) G02B ^7/ 04-7/10 G03B 17/04

Claims (5)

(57) [Claims] 1. A lens barrel having a photographic lens that can be shortened, wherein the lens barrel has a moving frame that is provided in the lens barrel and has a rod member as a linear guide member, and the lens barrel is shortened. when the lens barrel outer peripheral surface of the rod member is characterized that you have to <br/> protrudes to the outside from the outside rear surface of the photographing lens. 2. A lens barrel having a taking lens which can be moved to a housed state, the lens barrel having a moving frame provided in the lens barrel and having a rod member as a linear guide member, and the taking lens being put in a housed state. migrated to when the lens barrel outer peripheral surface of the rod member is characterized that you have to protrude to the outside from the outside rear surface of the photographing lens. Wherein said taking lens, a lens barrel according to claim 1 or 2, characterized in that a zoom lens. Wherein said moving frame, the lens barrel according to claim 1 or 2, wherein the lens is a holding frame of a lens for holding. 5. The lens barrel is attached to a mirror box having a reflection mirror.
Alternatively, the lens barrel described in 2.