JP2002341225A - Lens barrel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lens barrel which has enhanced working property at an assembly time and surely moves a movable frame by a simple structure. SOLUTION: This lens barrel has rods 7f and 8h arranged inside a lens barrel, third group and fourth group lens holding frames 8 and 9 relatively moved to the rods 7f and 8h and sleeves 8a and 9c fixed at the third group and fourth group lens holding frames 8 and 9 with adhesive and having outer peripheral grooves 8t and 9h provided at a part exposed by the third group and fourth group lens holding frames 8 and 9.

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 moving frame member.

[0002]

2. Description of the Related Art Conventionally, many proposals have been made regarding a mechanism for moving a lens frame of a lens barrel. For example, in a lens barrel disclosed in Japanese Patent Application Laid-Open No. 4-52628, a moving frame guided and moved by a rod member within the lens barrel is provided with a sleeve so as to fit around the rod member and slide. Has a structure in which the sleeve is loosely fitted to the moving frame and the sleeve is fixed to the moving frame with an adhesive after adjusting the optical axis with the other frame members.

[0003]

However, in the lens barrel disclosed in the above-mentioned Japanese Patent Application Laid-Open No. 4-52628, the adhesive flows to the rod member when the sleeve is bonded to the moving frame. Therefore, inconvenience may occur in sliding between the rod member and the sleeve.

An object of the present invention is to provide a lens barrel which has a simple structure, improves workability at the time of assembling, and ensures movement of a moving frame.

[0005]

The lens barrel according to the first aspect of the present invention includes a rod member disposed in the barrel, a frame member that moves relative to the rod member, and an adhesive attached to the frame member. And a sleeve member having an outer peripheral groove provided in a portion exposed from the frame member.

The lens barrel according to the second aspect of the present invention
In the lens barrel according to the first aspect, the sleeve member is provided with a gap so as to be loosely fitted to the frame member, and is fixed by filling the gap with an adhesive. And

Further, the lens barrel according to the third aspect of the present invention
In the lens barrel according to the first or second aspect of the present invention, the sleeve member is a tubular member, and has the outer peripheral groove at both ends.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below based on the illustrated embodiment. FIGS. 1, 2 and 3 are an exploded perspective view and a longitudinal sectional view of a zoom lens barrel in a collapsed state, respectively, showing an embodiment of the present invention. This zoom lens barrel enables zooming, focusing and collapsing operations. The main components of the zoom lens barrel include a fixed frame 1, a fixed lens frame 2 fixed to the fixed frame 1, a focus ring 3, an inner zoom ring 4 as a first frame, and a second frame. A certain outer zoom ring 5, a first group frame 6 which is a focusing lens group frame, a second group lens holding frame 7 which is also a focusing lens group frame, and a second group lens which is a lens group frame other than the focusing lens. The third and fourth lens holding frames 8 and 9, the fifth lens holding frame 10, and the first, second, third, fourth and fifth lens 20 held directly or indirectly by the frames, respectively.
21, 22, 23, and 24 (see FIG. 3), a focus drive unit 11, a zoom drive unit 12, an aperture unit 13, and a zoom encoder unit. The lens groups 20 to 24 are not shown in FIGS. 1 and 2, but are shown in the cross-sectional view of FIG.

The fixed frame 1 is fixed to a mirror box 16 of the camera body via spacers 14 and 15.
As shown in FIG. 5, the distance between the mirror frame 17 holding the movable reflection mirror 19 and the fixed frame 1 is adjusted by the spacers 14 and 15 as shown in FIG. The fixed frame 1 has a hole 1a for supporting the fifth group lens frame 10 at the center thereof, and a fitting portion 1d for fitting the fixed lens frame 2 integrally with the mounting flange portion. Furthermore, a cylindrical portion 1e for supporting the inner zoom ring 4 so as to be rotatable around the optical axis O is provided, and a slide pin 1g is screwed by a screw 1f to restrict the movement of the inner zoom ring 4 in the optical axis direction. It is fixed on the cylindrical portion 1e.

The fixed frame 1 is provided with a fitting hole 1b and a fitting elongated hole 1c for supporting the second group main rod 7e and the second group sub rod 7f so as to be slidable in the optical axis direction. . Further, the focus drive unit 11 is mounted on a mounting 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. Further, the aperture unit 1
3 is also pivotally mounted on the fixed frame 1 via the 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 along the optical axis O
And the guide rectilinear grooves 2b and 2c of the second group lens holding frame 7,
A bottomed inner circumferential groove 2g for regulating the axial position of the focus ring 3 is also formed along the circumferential direction of the inner circumference on the fixed frame 1 side, and similarly in the circumferential direction of the cylindrical portion opposite to the fixed frame side. An elongated hole 2d for regulating the axial position of the contact stand 13 is provided along each of them. As shown in the developed view of FIG. 15, the rectilinear 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 therein, and a width larger than the outer diameter. It is assumed that it is formed from the collapsible region groove 2i. 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 with 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. A sliding pin 3b is provided on the pin fixing portion of the outer peripheral portion.
Is fixed by the screw 3a. The slide pin 3b is slidably fitted in the inner peripheral groove 2g of the fixed lens frame 2, and prohibits the movement of the focus ring 3 in the optical axis O direction. Further, a slide pin 3d for moving the zoom ring 5 in the optical axis direction is fixed to a pin fixing portion 3g on the protrusion which is loosely fitted on the inner periphery of the outer zoom ring 5 by 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 in the inner peripheral portion. The sliding pin 1g of the fixed frame 1 is fitted in the zoom ring 4, and the movement of the zoom ring 4 in the optical axis direction is prohibited. The inner peripheral portion includes the zoom drive unit 1 driven based on a zoom control signal.
An internal gear 4c with which the second output gear 12a meshes is provided.

The zoom ring 4 is provided with cam grooves 4a and 4b as first cam means for driving the third and fourth lens holding frames 8 and 9 for zooming. Slide pins 8j and 9f fixed to the third and fourth lens holding frames 8 and 9 are fitted into these cam grooves 4a and 4b, and the cam shape is shown in a developed view of FIG. So that
They are formed by cam grooves 4g and 4h in the retracted area corresponding to the lens barrel retracted state having no displacement in the optical axis direction, 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 into the rectilinear groove 5a of the outer zoom ring 5, is rotatably supported by a pin 4e on the outer peripheral portion.

The outer zoom ring 5 is a cylindrical member, and its outer and inner peripheral portions are rotatably or slidably fitted into the fixed lens frame 2 and the first group frame 6, respectively. Then, a straight groove 5a is provided along the optical axis O,
The inner zoom ring 4 performs a rotational drive corresponding to the zoom amount via a roller 4f fitted in the groove.
Further, the main zoom ring 5 is provided with a focus cam groove 5b corresponding to the amount of focusing and the sliding pin 3d of the focus ring 3 is fitted.
Is moved straight in the optical axis direction by the focusing amount.

Further, the zoom ring 5 is provided with cam grooves 5c and 5d as second cam means. The first and second group rollers 6 supported by the first group frame 6 and the second group lens holding frame 7 are provided in the cam grooves 5c and 5d.
b, 7j are fitted. Therefore, the first group frame 6 and the second group lens holding frame 7 are displaced in the direction of the optical axis O in accordance with the rotation of the zoom ring 5 by zooming or the axial movement by focusing. The cam grooves 5c and 5d are provided in the cam portions 5i and 5 in the zoom region for providing the driving positions during focusing and zooming, respectively.
h and cam portions 5j and 5g in the retracted area for moving the first group frame 6 or the second lens holding frame 7 to the retracted position when the camera is not used, that is, for retracting into the camera body.
And formed from. The groove width of the cam portion 5g is formed to be larger than the outer diameter of the roller 7j to be inserted, so that interference between the lens groups does not occur during the retraction (see FIG. 15).

The present zoom ring 5 is provided with a stepped square hole 5f for guiding a contact piece 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. I have.

The first group frame 6 is 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. A first group roller 6b is rotatably attached to a corresponding portion 6f of the cam groove 5c on the outer peripheral portion by a pin 6a. The first group roller 6b is connected to the cam groove 5
c and the rectilinear groove 2b of the fixed lens frame 2.
Accordingly, the first group frame 6 is moved in accordance with the rotation or the straight movement of the zoom ring 5 while being guided straight in the direction of the optical axis O by the straight groove 2. In addition, a concave portion 6e that forms a thin portion along the axial direction is provided on the inner periphery of the first group frame 6. The recess 6e serves as a relief for a second group drive plate 7h to be 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 the first group lens 20 is supported by the first group frame 6. The second group lens holding frame 7 holds the second group lens frame 7a to which the second group lens 21 is attached. Then, as shown in FIG. 4, two U-shaped notches 7 are formed in the outer portion to fix and support the rod, which is a rod-shaped guide member.
b is provided facing the optical axis of the lens frame. 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. One end of a second-group main rod 7e or a second-group sub-rod 7f, which is a rod-shaped guide member, is inserted into the notch 7b, and the U-shaped fixing piece 7 is used to fix the fixing piece 7 via a screw 7g. The rods 7e and 7f are pressed against each other and fixed by the inclined surface. Then, since each rod is pressed by the slope of the fixing piece 7, the rod 7
e and 7f are respectively in contact with the two sides 7c of the cutout portion 7b, and as a result, they are mounted in parallel with the optical axis of the lens frame.

Then, the rods 7e, 7f mounted are mounted.
The other ends are the fitting hole 1b and the fitting long hole 1 of the fixed frame 1.
c to be slidably inserted. Therefore, the second group lens 21
The second group lens holding frame 7, on which is mounted, can slide forward and backward along the optical axis O without rotating. Further, a third lens holding frame 8 of another lens holding frame slidably supported and guided by the rods is inserted into an intermediate portion between the rods 7e and 7f.

A second group drive plate 7h for driving in the axial direction and extending in the optical axis direction is fixed to the main holding frame 7 via screws. A roller 7j is rotatably attached to the tip of the driving plate 7h via a pin 7i. 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, with the rotation and the axial movement of the outer zoom ring 5, the second zooming is performed via the driving plate 7h.
The group lens holding frame 7 moves in the direction of the optical axis O, and the second group lens 21 is similarly moved. The driving plate 7h
The concave portion 6e provided in the first group frame 6 due to its arrangement
It is located in the space part of.

The third lens group holding frame 8 is provided with the third lens group 2.
A second group main rod 7e fixed at a position opposite to the optical axis on the second group lens frame 7
And the sub-rod 7f is slidably supported in the optical axis direction. That is, the rod 7e is fitted into the notch 8c of the third lens group holding frame 8, while the sub rod 7f is
As shown in the mounting state diagram of FIG. 5, the holding frame 8 is supported via a sleeve 8a into which it is fitted. The sleeve 8a is fixed to the holding frame 8 with an adhesive H,
The outer diameter of the sleeve itself has such a size as to be loosely fitted in the mounting hole 8b of the holding frame 8.

FIG. 18 shows a state in which a sleeve 8a to be loosely fitted to the above-mentioned third lens group holding frame 8 is adhered and fixed. Sleeve 9 loosely fitted to group lens holding frame 9
FIG. 4 is a partially enlarged view showing a state where c is bonded and fixed, and this figure is drawn in an example to be described later, but will be used for description in common use.

The sleeve 8a is a tubular member. The sub-rod 7f can be fitted into the inner diameter of the sleeve 8a, and an outer peripheral groove 8t is formed in the outer periphery near both ends in the axial direction.

In order to perform the above-mentioned bonding, first, the convex fitting portion 7k of the second lens group holding frame 7 and the concave fitting portion 8d of the third lens group holding frame 8, which are formed concentrically with the optical axis, respectively. At this time, the rod 7e is inserted into the notch 8c, and the rod 7f is inserted into the mounting hole 8b with the sleeve 8a fitted. At this time, the sleeve 8a
Is located at a position where the outer peripheral groove 8t is exposed from the mounting hole 8b of the third group lens holding frame 8. Then, the adhesive H is passed through the inside of the mounting hole 8b from the outer periphery thereof and from the mouth of the adhesive filling hole 8u formed in the third lens holding frame 8.
Is injected into the gap between the sleeve 8a and the hole 8b to perform the bonding. During the adhesive filling operation, the adhesive H overflows from the mounting hole 8b. However, since the adhesive H is once accumulated in the outer peripheral groove 8t, the adhesive H is applied from both ends of the sleeve 8a at a stretch. H does not flow out to the rod 7f, and a reliable operation can be performed while checking the filling state.

The sleeve 8a is integrally fixed to the third lens group holding frame 8 by the above-described adhesive filling operation. In this manner, the third lens group holding frame 8 and the third lens group 22 are mounted concentrically with the optical axis center correctly, and can slide forward / backward without rotation without being rotated and parallel to the optical axis direction. State. Note that the third
It is assumed that a compression spring 18 for removing play of both frames is inserted into a rod 7f between the group lens holding frame 8 and the second group lens holding frame 7.

The third group lens holding frame 8 has two third group rods 8h and a sub rod 8k for supporting a fourth group lens holding frame 9 described later slidably in the optical axis O direction.
Is installed. The sub rod 8k is implanted and fixed to the third lens group holding frame 8 in a state parallel to the optical axis O.
The implanted hole 8r is drilled with high precision such as hole diameter and parallelism by machining or molding. Then, the rod 8k is press-fitted into the hole 8r and implanted. The sub-rod 8k and the rod 8h are disposed so as to be substantially opposed to the optical axis O (see FIG. 6). On the other hand, the rod 8h is supported by the third lens group holding frame 8 and the arm 8e provided on the third group lens holding frame 8 as shown in FIG. 5, but the mounting holes 8g and 8f are in a state of loosely fitting with the rod 8h. The fixing is performed by bonding. Prior to the bonding,
A sleeve 9c that is loosely fitted to the fourth group lens holding frame 9 is adhesively fixed.

That is, a sleeve 9c, which is loosely fitted in a through hole 9b provided in a sliding arm portion 9a of the holding frame 9, is inserted into the sleeve 9 with respect to the optical axis of the frame 9 using a mechanical jig. 9c is held in parallel. In that state, adhesive H
Thereby, the sleeve 9c is fixed to the hole 9b.

In this bonding operation, the sleeve 9c
Is located at a position where the outer peripheral groove 9h is exposed from the through hole 9b of the fourth group lens holding frame 9. The adhesive H is injected into the through hole 9b from the outer periphery of the adhesive filling hole 9i formed in the fourth group lens holding frame 9 by penetrating the through hole 9b from the outer periphery, thereby bonding the gap between the sleeve 9c and the hole 9b. The agent H is allowed to flow in for bonding. During the adhesive filling operation, the adhesive H overflows from the through hole 9b, but since the adhesive H is once accumulated in the outer peripheral groove 9h, the adhesive H is bonded from both ends of the sleeve 9c at once. The agent H does not flow out to the rod 8h, and a reliable operation can be performed while checking the filling state. By the above-described adhesive filling operation, the sleeve 9 is attached to the fourth group lens holding frame 9.
c is in a state of being integrally fixed.

Then, the rod 8h is inserted into the sleeve 9c and penetrates the same, and further, the hole 8 is a loose fitting hole of the arm 8e.
f and hole 8g. Note that an E-shaped retaining ring 8m for preventing displacement before bonding is attached to the end of the rod 8h.

Subsequently, the convex fitting portion 9g of the fourth group lens holding frame 9 provided concentrically with the optical axis is replaced with the concave fitting of the second group lens holding frame 8 similarly provided concentrically with the optical axis. Joint 8p
And at the same time, the sub-rod 8k is
Into the notch 9d. In this manner, the optical axes of the holding frames 8 and 9 are made to coincide with each other, and further, the direction of the rod 8h is made to coincide, and the rod 8h and the holes 8g and 8f of the holding frame 8 are adhered and fixed by the adhesive H. The holding frame 8,
The third and fourth lens units 22 and 23 held at the optical axis O
And can be moved in parallel.

The pin mounting portion 8 of the third group lens holding frame 8
A sliding pin 8j fitted into a cam groove 4a provided on the inner zoom ring 4 is fixed to the inner zoom ring 4 by a screw 8i. Therefore, the rotation of the zoom ring 4 causes the holding frame 8 to move in the optical axis O direction. Is moved forward and backward.

An aperture unit 13 is mounted on the subject-side surface of the third lens group holding frame 8. The charge lever 25 pivotally attached to the fixed frame 1
Thus, the aperture operation of the aperture unit 13 is performed via the charged lever 13a. The charged lever 1
3a is a member which is long in the optical axis direction, so that the engagement with the charge lever 25 does not come off even if the holding frame 8 moves in the optical axis direction. Since the aperture unit 13 has a built-in photo interrupter and an electromagnet device for adjusting the aperture, it must be electrically connected to the camera. Therefore, this unit 13 includes the flexible board 1
3b is provided.

The fourth lens group holding frame 9 holds the fourth lens group 23, and is moved in the optical axis direction by the two rods 8h and 8k of the third lens group holding frame 8 as described above. It is slidably supported. The rod 8h is supported via a sleeve 9c. A sliding pin 9f fitted into a cam groove 4b provided on the inner zoom ring 4 is provided on a sliding arm 9a of the fourth group lens holding frame 9 with a screw 9.
e, the holding frame 9 is moved forward and backward in the optical axis O direction by the rotation of the zoom ring 4.

The fifth lens group holding frame 10 holds the fifth lens group 24, and is mounted by first fitting its outer periphery 10a into the fitting hole 1a of the fixed frame. The axis and the optical axis O are matched. Then, the fixing portion 10b of the holding frame 10 is attached to the fixing frame 1 by 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 around the optical axis. As shown in FIG.
A contact piece 13d fixed to the contact piece base 13 and sliding on the conductive pattern of the encoder board 14;
4 and a metal plate 14a for protecting the substrate 14. The contact base 13 has protrusions 13c on both side surfaces,
Edge projections 13a with a slight height in the direction of the contact piece 13d are provided on both side surfaces. Then, it is inserted into the stepped square hole 5f of the outer zoom ring 5 having the stepped portion 5k. The back surface of the edge 13b of the contact piece 13 is attached to the stepped portion 5k of the square hole 5f. The square hole 5f has such a size that the fitting surface 5e in the rotating direction of the zoom ring 5 fits into the edge 13b of the contact piece base 13 without a gap, and the length in the axial direction is the contact piece. It is larger than the width of the edge projection 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 positioned above the square hole 5f, and the width of the elongated hole 2d in the rotation direction is limited with respect to the circumferential movement of the contact piece base 13. The width in the axial direction, which is the fitting width portion 2e, is set to a width that allows the outer zoom ring 5 to be rotationally driven. I do. Therefore, the segment table 13 can move on the elongated hole 2d in accordance with the rotation angle of the contact piece table 13 in the entire axial movement range of the outer zoom ring 5. Since the contact piece 13d slides on the encoder board 14 disposed along the elongated hole 2d and moves in the rotational direction, the rotation angle of zooming of the zoom ring 5 can be detected. In the encoder section, the projection 13c has a long hole 2d.
Is held down by the edge of the width portion 2e, so that the contact piece base 13 is hardly detached from the square hole 5f.

The focus drive unit 11 will be described with reference to FIGS. FIG.
FIG. 9 is a perspective view seen from the back side. FIG. 10 is a diagram showing a YY cross section of FIG. The unit 11 includes a unit case 20, a focus driving motor 21, and a motor output gear 2 which is an output gear fixed to a motor output shaft 21a.
1b, a reduction gear train, a gear meshing with the gear 21b, a sun gear, a planetary gear, a unit output gear 11a, a unit case stopper plate 31, a drive unit rotation detector, and And the flexible printed circuit board 11s for electrical connection to the motor 20 and the PI 23. As described above, since the unit 11 is attached to the attachment surface 1h of the portion where the cylindrical portion 1e of the fixed frame 1 is cut off as described above,
It is assumed that the motor 21, the reduction gear train, the case 20, the case stopper plate 31, and the like are disposed along the curvature of the cylindrical portion 1e (see FIG. 11).

The rotation detecting section comprises a slit plate 22 and a photo interrupter PI23. The PI 23 is fixed to the unit case 20 by screws via a lubricating slide plate 23a. And
The slit plate 22, which gives an input signal to the PI 23 by its rotation, is provided with a gear 2 meshing with the motor output gear 21b.
2a, and is rotatably fitted to the shaft portion 20a of the case 20. Then, the slide plate 23 acts as an axial stopper for the gear 22a.

The power transmission path by the reduction gear train between the motor output gear 21b and the unit output gear 11a is as follows. First, the motor output rotation is performed by the gear 2 having the sun gear portion 24b via the gear 22a meshing with the gear 21b.
4 is transmitted. Then, the rotation of the sun gear portion 24b is transmitted to three planetary gears 25 meshing with the sun gear portion 24b. The planetary gear 25 is axially supported by a shaft portion integrally provided on a support of the sun gear 28 with an axial stopper provided. And, it meshes with an internal gear 20 d provided on the inner wall of the case 20. Therefore, the planet gear 25 rotates and revolves by 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 meshing with the sun gear 28 and the sun gear 29 rotated by the gear, and further to the planetary gear 27 meshing with the sun gear 29 and the gear 30 rotated by the gear. Further, the gear 30 meshes with the unit output gear 11a, which is the last stage, and a rotational output reduced from the output gear 11a is obtained.

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

The attachment of the unit 11 to the lens barrel is shown in FIGS.
As shown at 0, the case stopper plate 31 is brought into contact with the mounting surface 1h of the fixed frame 1 and the positioning dowels 31a are inserted into the corresponding holes of the fixed frame 1 and screws are screwed into the mounting screw portions 20e. This unit 11 is fixed 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, is brought into mesh with the unit output gear 11a, and the focus drive is enabled.
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 as described above. It is transmitted in the N direction opposite to the M direction. Then, the rotation 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 electric connection has guide pieces 20g, 20g in which the board section 11s connected to the PI 23 is integral with the case 20.
h, 20i. The substrate 11s
The L-shaped portion 11t at the tip of the is used to prevent the guide piece 20i from coming off (see FIG. 8).

FIG. 12 is a sectional view taken along line XX of FIG.
FIG. 3 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, a light-shielding surface 20f having a triangular groove cross section with a small pitch is provided to shield unnecessary light outside the light beam L. Also, the printed circuit board 1
1s is bent in an S-shape and guided to the rear side of the fixed frame 1.

The zooming, focusing and collapsing operations of the zoom lens barrel constructed as described above according to the present embodiment will be described. In the following description, the direction of rotation is indicated by the direction of rotation viewed from the subject side.
FIG. 3 shows the lens barrel collapsed state of the lens barrel, in which the first group frame 6 and the second group lens holding frame 7 are collapsed, and the second group main rod 7e is projected behind the fixed frame. It has become. First, the zooming operation from this state to the long focal length side will be described.

FIG. 13 shows the extended position between the wide end and the telephoto end of each lens unit. The first group is moved 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. With the rotation, the sliding pins 8j and 9f are
Among the grooves 4a and 4b, the grooves 4g and 4h in the collapsed area are located in the grooves 4i and 4j in the zoom area (see FIG. 14). Then, the third and fourth lens groups 8 and 9 to which the pins are fixed move, and the third and fourth lens groups 22 and 23 move.
Is fed 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 grooves 5j and 5g in the collapsed area to the grooves 5i and 5h in the zoom area among the cam grooves 5c and 5d (FIG. 15).
(A)). At the same time, since the rollers 6b and 7j are also fitted in the rectilinear grooves 2b and 2c of the fixed lens frame 2, the rollers 6b and 7j move straight in the direction of the subject. The straight groove 2c
At the time, the groove 2i in the collapsed area moves to the straight groove 2h in the zoom area.

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 is moved in the direction toward the object by the action of this cam. Move by the focus correction amount. Therefore, the amount of movement of the first group frame 6 or the second group lens holding frame 7 to which the rollers 6b and 7j are directly or indirectly fixed by zooming is limited to the outer zoom ring 5.
Is moved by the sum of the movement amount driven by the cam grooves 5c and 5d and the focus correction amount driven by the focus cam groove 5b. Although the description of the zoom movement amount has been described in the case of the zoom drive to the long focal length side, the zoom drive to the short focal length side can be performed by driving the inner zoom ring in a counterclockwise direction. Is an operation in the direction opposite to the above-described zoom drive.

The rotation of the outer zoom ring 5 is detected by the zoom encoder unit in the detection of the zoom state accompanying the above-mentioned zoom drive. The operation thereof will be described with reference to FIGS. 1, 2 and 7. The conductive pattern on the encoder board 14 attached to the frame 2 is brought into sliding contact with the contact piece 13d supported by the contact piece base 13 to extract a coded signal relating to the zoom position. And, the contact piece table 13
Is inserted into the square hole 5f of the outer zoom ring 5 in the circumferential direction only in the fitted state as described above, and is further fitted in the axial direction with the width portion 2e of the elongated hole 2d of the fixed lens frame 2. With the rotation of the zoom ring 5, the contact piece 13d slides on the conduction pattern.
The zoom ring 5 also moves in the axial direction,
In this case, since the hole width in the axial direction of the square hole 5f is larger than the contact piece base 13, the contact piece base 13 has its edge protrusion 13a guided to the width portion 2e of the long hole 2d of the fixed lens frame 2. Contact piece 13
d can slide on the encoder board 14 to output a zoom position detection signal.

Next, the focusing operation will be described for the case where focusing is performed from a state corresponding to the ∞ distance (infinity distance) of the subject to a predetermined subject distance. The focus drive unit 11 is driven based on a focusing 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, so that the zoom ring 5 moves to the subject side.
In this case, since the inner zoom ring 4 is in a stationary state, the outer zoom ring 5 moves straight. And the rollers 6b, 7j
The first group frame 6 or the second group lens holding frame 7 is moved through, and the first group lens 20 and the second group lens 21 which are the focusing lens groups are extended toward the subject. Note that the focusing operation from a short distance to a long distance of the subject is performed by driving the focus ring 3 in a direction opposite to the above.

Next, the retracting operation of the lens barrel of the zoom lens barrel according to the present embodiment at the end of photographing will be described with reference to FIGS.
15 (A) and 15 (B). First,
The focus drive unit 11 is driven, and the focus ring 3 is rotated clockwise, so that the first and second lens groups are retracted toward the camera body to the infinity in-focus position.

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

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 positioned in the cam grooves 5g and 5j in the collapsed areas of the cam grooves 5c and 5d of the zoom ring 5. Accordingly, the first group frame 6 and the second group lens holding frame 7 are retracted from the position corresponding to the ∞ distance to the retracted position further retracted toward the camera body. If the first group frame 6 is retracted to the retracted position as described above, the second group lens holding frame 7 must be moved to a position outside the normal zoom range, unless the first group lens holding frame 6c or the first group. Interference with the lens 20 or the like or clogging occurs. Therefore, the rectilinear groove 2i and the cam groove 5g in the collapsed area are loosely fitted to the roller 7j fitted therein, so that the above-described interference is avoided and the collapse is performed reliably.

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

In FIG. 16, a rod 57 having a good straightness is shown.
The notch 57b for holding e and 57f is disposed on the outer peripheral portion of the second lens group holding frame 57 so as to be substantially opposed to the optical axis of the holding frame. The notch 57b has a side contact surface 57c and bottom contact surfaces 57k, 57m parallel to the optical axis with which the rods 57e, 57f contact. The cylindrical outer diameter surfaces 57k and 57m serving as the bottom contact surfaces are held by the holding frame 7.
Utilize the cylindrical part provided in the. The cylindrical outer diameter surfaces 57k 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 that is recessed from the contact surface.

Then, each rod is fixed by the rod 57.
e, 57f are inserted into the notches, and two fixing pieces 57
The inclined surfaces at the distal end of d are positioned on the rods 57e and 57f, respectively, and fixed by pressing with screws 57g. Since the portion between the bottom contact surfaces 57k and 57m is concave as described above, the rods 57e and 57f more reliably contact the side contact surfaces 57c and the bottom contact surfaces 57k and 57m. Can be touched. Therefore, according to this modification, the rod supporting the lens holding 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 also possible to propose a structure using a V-shaped notch groove instead of the U-shaped notch fixing groove of the above-described embodiment. It is. In this modification, the V-shaped cutout groove is provided on the outer periphery of the lens holding frame so as to be substantially opposed to the optical axis, and the cutout groove is also in a state parallel to the optical axis. Then, the rods 7e and 7f are attached to the notched grooves and fixed to the holding frame with a flat fixing plate. The rod fixed in this manner is also supported in parallel with the optical axis with high accuracy, but the V-shaped notch can be easily machined or formed so that the degree of parallelism can be easily obtained, so that a more accurate fixing is possible. Becomes possible.

FIG. 19 shows a state in which the sleeve 8a which is loosely fitted to the above-described third lens group holding frame 8 is bonded and fixed, and a sleeve 9c which is loosely fitted to the fourth lens group holding frame 9 is bonded and fixed. FIG. 19 is a partially enlarged view showing a modified example of the embodiment with respect to FIG. 18 is different from FIG. 18 in that the outer peripheral grooves 8T, 9H formed near both ends of the sleeves 8A, 9C are extended in the axial direction to be longer, and some of the mounting holes 8b, 9 are provided.
b. Thereby, the lengths of the sleeves 8A and 9C in the optical axis direction can be shortened and the space can be reduced, and the outer peripheral groove 9H can be formed similarly to the above-described embodiment.
While confirming the flow state of the adhesive H to the substrate, reliable work can be performed without any problem.

As described above, in the zoom lens barrel according to the present embodiment, the zoom ring is divided into the first and second inner and outer frames, and the outer and outer zoom rings 4 and 5 are rotated or moved straight. By driving, a zooming operation, that is, a 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 a focusing operation. According to the present embodiment, since the inner and outer zoom rings 4 and 5 are disposed so as to overlap with each other, the total length of the lens barrel can be further reduced.

In the zoom lens barrel according to the present embodiment, the main rod 7e and the sub rod 7f, which are rod-shaped guide members for sliding the second lens group holding frame 7, are fixed.
The rod is pressed and fixed to a U-shaped notch 7b provided on the holding frame 7 and having two contact surfaces parallel to the optical axis. If the notched portion is formed with high precision by, in particular, machining or molding the contact surface, the rod can be fixedly supported on the holding frame more accurately than a 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.

The sleeve 8a in which the rod 7f for sliding support of the third lens group holding frame 8 in the present embodiment is fixed is bonded. That is, in order to make the optical axes of both the second group lens holding frame 7 and the holding frame 8 coincide with each other, the two lens groups are held in a state where the concentric fitting portions are fitted to the optical axes, respectively. The fitted sleeve 8a is slidably fitted into the rod 7f fixedly supported by the holding frame 7, and in this state, the loosely fitted sleeve 8a is fixed to the holding frame 8 by bonding. Therefore, it is possible to maintain the positional accuracy of each member at the time of performing the bonding, and in particular, it is possible to assemble a higher positional accuracy between the holding frames without increasing the component accuracy or the like of each member itself. . Also, during the adhesive filling operation, the adhesive H overflows from the mounting hole 8b, but since the adhesive H once accumulates in the outer peripheral groove 8t, the adhesive H rushes from both ends of the sleeve 8a. The adhesive H does not flow out to the rod 7f, and a reliable operation can be performed while checking the filling state.

Further, the rod 8h, which is a guide member of the fourth lens group holding frame 9 in the zoom lens barrel of the present embodiment, is fixed to the third lens group holding frame 8 by bonding. That is, to keep the optical axes of both frames coincident with each other, a state where the concentric fitting portions are fitted to the optical axes is held,
Further, the rod 8h fitted in the holding frame 9 is loosely inserted into the holding frame 8, and the rod 8h is bonded to the holding frame 8 in this state.

Since the sleeve 9c is fixed in this manner, the positional accuracy of each member at the time of bonding can be maintained. In particular, a higher holding accuracy can be achieved without increasing the fitting accuracy of each member. It is possible to assemble the positional accuracy between the frames. Also, during the adhesive filling operation, the adhesive H overflows from the through hole 9b. However, since the adhesive H is once accumulated in the outer peripheral groove 9h, the adhesive H is rushed from both ends of the sleeve 9c. The adhesive H does not flow out to the rod 8h, and a reliable operation can be performed while checking the filling state.

The focus drive unit 11 of the zoom lens barrel according to the present embodiment is disposed in a part of a donut-shaped space in the lens barrel in order to efficiently store the lens, and its outer shape is changed to the cylindrical part of the lens barrel. A corresponding predetermined curvature is given, and the motor and the reduction gear train are arranged according to the curvature.
Further, the output axis of the motor and the axis of the reduction gear train are aligned with the optical axis O.
It is arranged so as to be parallel to. Then, in order to drive the focus ring 3 conveniently, the output gear 2 of the motor is used.
1b and a unit output gear 11a for taking out the rotational output of the drive unit are located on the motor mounting side where the internal gear 3e of the focus ring 3 of the driven portion is located. Accordingly, the direction of extension of the motor output shaft to which the motor output gear 21b is fixed is opposite to the direction of the driven portion, and the extension of the shaft portion of the reduction gear train to which the unit output gear 11a is mounted in front thereof. By setting the direction to be opposite to the extending direction, a more efficient drive system path can be obtained. The drive unit 11 configured as described above enables the storage space for the lens barrel to be efficiently used, and does not require an unnecessary increase in the diameter of the lens barrel.

[0064]

According to the present invention, it is possible to provide a lens barrel which has a simple structure, improves workability at the time of assembling, and ensures movement of the moving frame.

[Brief description of the drawings]

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

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

FIG. 3 is a longitudinal sectional view of the lens barrel shown in FIGS. 1 and 2 in a lens barrel collapsed state.

FIG. 4 is a view taken in the direction of arrow A as viewed from the direction of arrow A shown in FIG. 1;

FIG. 5 is a diagram showing a rod fixed state of each lens holding frame of the lens barrel in FIG. 1;

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

FIG. 7 is a development view of a zoom encoder unit of the lens barrel in FIG. 2;

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

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

FIG. 10 is a sectional view taken along line YY in FIG. 8;

FIG. 11 is a view showing a state where the lens barrel in FIGS. 1 and 2 is mounted on a fixed frame of a focus drive unit.

FIG. 12 is a sectional view taken along line XX in FIG. 11;

FIG. 13 is a view showing the extended position of each lens group in the zoom drive of the lens barrel in FIG. 1;

FIG. 14 is a development view of a cam groove of an inner zoom ring of the lens barrel in FIG. 1;

15A is a developed view of the inner and outer zoom rings of the lens barrel in FIGS. 1 and 2 during a zoom operation, and FIG.
FIG. 3 is a development view of the inner and outer zoom rings of the lens barrel in FIGS. 1 and 2 when the lens barrel is collapsed.

FIG. 16 shows a second example of the lens barrel in FIGS. 1 and 2;
FIG. 11 is a longitudinal sectional view showing a rod fixing state of a second lens group holding frame according to a modification of the rod fixing structure of the group lens holding frame.

FIG. 17 is a perspective view showing the rod-fixed state of the second group lens holding frame according to the modified example of FIG. 16;

FIG. 18 is a partially enlarged view showing a state in which a sleeve 8a that is loosely fitted to the third lens group holding frame 8 is adhered and fixed in FIG. 5 of the embodiment of the present invention.

FIG. 19 shows a state in which a sleeve 8a which is loosely fitted to the third lens group holding frame 8 is adhered and fixed, and the fourth lens group holding frame 9
FIG. 19 is a partially enlarged view showing a modification of the embodiment shown in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Fixed frame 4 ... Inside zoom ring 5 ... Outside zoom ring 6 ... First group frame 7 ... Second group lens holding frame 8 ... Third group lens holding frame 9 ... Fourth group lens holding Frame 7f, 8h Rod 8a, 9c Sleeve 8b, 9b Mounting hole (through hole) 8t, 9h Peripheral groove 8u, 9i Adhesive filling hole H Adhesive

Claims (3)

[Claims] 1. A lens barrel, wherein: a rod member disposed in the lens barrel; a frame member moving relatively to the rod member; and a frame member fixed to the frame member with an adhesive and exposed from the frame member. And a sleeve member having an outer peripheral groove provided in a portion of the lens barrel. 2. The apparatus according to claim 1, wherein the sleeve member is provided with a gap so as to be loosely fitted to the frame member, and is fixed by filling the gap with an adhesive.
The lens barrel according to item 1. 3. The sleeve member is a tubular member,
3. The lens barrel according to claim 1, wherein the outer peripheral groove is provided at both ends.