JP3328036B2 - Mirror frame moving mechanism - 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 frame moving mechanism, and more particularly to a lens frame moving mechanism using a cam ring.

[0002]

2. Description of the Related Art As a type of a conventional zoom lens for a video camera or the like, a multi-lens structure as shown in FIG. It is. In the configuration of the zoom lens shown in FIG. 12, the first lens group 102 and the third lens group 104 are fixedly held by the lens frame 100, and the second lens group holding frame 10 holds the second lens group 103 as a zoom lens.
8 and a fourth group lens holding frame 109 holding a fourth group lens 105 which is a focus lens and also corrects focal point movement during a zoom operation, are guided by guide shafts 112 and 113 supported by mirror frames 100 and 101, respectively. It is held movably in the axial direction. An optical filter 106 and a CCD 107 are provided behind the fourth group lens 105.

In FIG. 12, a portion D shows a driving mechanism of the second group lens holding frame 108. The second group lens holding frame 108 is driven by a feed screw 111 which is driven to rotate via a gear train. It is driven forward and backward.

The zoom lens shown in FIG. 12 has a small number of movable parts and has a simple structure. In addition, since the structure supports the movable lens holding frame that is moved by the guide shaft, small and highly accurate support is possible.

However, in recent years, there has been a growing demand for a zoom lens for a video camera to have a higher magnification and a wider angle of view. However, if the zoom lens of FIG. However, the outer shape of the lens barrel becomes considerably large. Then, this is against the trend of miniaturization of the video camera itself.

Therefore, a zoom lens for a video camera targeting a specification of a high magnification and a wide angle of view has a structure different from that of FIG. 12 and a movable lens holding frame for zooming. Efforts have been made to provide a small lens barrel with a high magnification and a wide angle of view using a type in which the number of lenses is increased. In particular, making the first group lens a movable holding frame for the zoom lens of FIG. 12 greatly contributes to size reduction.

[0007]

However, when trying to realize a lens barrel in which the first lens group of the zoom lens shown in FIG. 12 is movable as described above, the first lens group is exposed to the external appearance of the video camera. There is a possibility of receiving external force,
It is necessary to ensure a predetermined strength. Even if the support structure of the first group frame in FIG. 12 employs a shaft suspension structure using a guide shaft, the strength is insufficient.

Therefore, as the drive structure of the first group frame, a conventional helicoid structure using a helicoid screw, or a groove cam provided on a cam ring via three drive pins fixed to a movable holding frame is used. It is conceivable to adopt a so-called three suspension structure or the like that drives the movable holding frame forward and backward. As shown in FIG. 13, for example, the helicoid screw driving structure includes a helicoid frame 210 having a male screw 210a provided on an outer periphery thereof, and a female screw 211a screwed to the male screw 210a. And a drive system including a drive motor 212 and a gear train 213. When the holding frame is rotated by the driving system via a driven gear 211b disposed on the outer periphery of the lens holding frame 211, the holding frame 2
11 moves relatively to the helicoid frame 210.

When the above-described conventional helicoid drive structure or three-suspension structure is used as a drive mechanism for a zoom lens, it is advantageous in terms of strength, but on the other hand, the support accuracy of the lens, that is, eccentricity with respect to the ideal optical axis. And the accuracy of inclination is inferior to that of the shaft suspension structure. For example, in the case of a three suspension structure, three cam followers of the lens holding frame are fitted and held in three cam grooves provided in the cam ring, and in that state,
The lens holding frame is urged in the optical axis direction. In this case, the inclination of the lens holding frame with respect to the optical axis during the movement depends on the difference in the positions of the three cam grooves of the cam ring. Therefore, it is necessary to manufacture the cam groove of the cam ring with a considerably high precision. With the accuracy of the normal cam groove, the inclination of the holding frame with respect to the optical axis is good, and the fluctuation of the inclination is small. We couldn't get less. In particular, when the diameter of the lens holding frame is reduced due to miniaturization, the influence of the accuracy of the cam groove on the inclination is large.

In order to meet the demand for cost reduction and weight reduction as a lens barrel of a video camera or the like, a helicoid screw member, a cam ring member, a movable lens holding frame member, etc.
It is desirable to mold, but in this case, it becomes more difficult to secure the lens support accuracy. On the other hand, in a lens of a video camera or the like, the lens support accuracy required for securing the optical performance is becoming increasingly severe in the trend of miniaturization and high performance. In addition, since the frame swing at the time of driving due to the play in the lens support structure leads to the problem of image swing and image jump at the time of zooming, it is strongly demanded to improve the lens support accuracy and to reduce the play amount. .

As described above, in a lens of a video camera or the like targeting a high magnification and a wide angle of view, when a helicoid screw structure and a three-suspension structure are adopted as a support mechanism of a movable lens holding frame, the holding frame is used. However, there is a problem in that it is difficult to ensure the support accuracy of the above, and the optical performance deteriorates.

Further, in order to realize a compact lens with a high magnification and a wide angle of view while achieving a high magnification and a wide angle of view, a lens type in which the number of movable holding frames for zooming is increased, as shown in FIG. It is difficult to apply the feed screw mechanism, and the structure of the zoom driving unit is complicated, and there is a problem that the capacity of the lens barrel with respect to the lens increases.

Therefore, assuming that a lens frame mechanism to which a cam ring is applied is used as the lens frame mechanism for performing the zoom drive, the number of movable lens holding frames for zooming is increased as described above to achieve a high magnification and a wide angle of view. However, due to the complexity of the mechanism, it has been difficult to accurately position the cam ring within a limited space.

The problems associated with increasing the magnification and widening the angle of view of the lens are not limited to the above-described video camera, but also have the same problem with a lens barrel for a still camera.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problem, and it is an object of the present invention to provide a lens-frame moving mechanism which can easily ensure lens support accuracy and can make the lens-frame compact. With the goal.

[0016]

According to the present invention, there is provided a lens frame moving mechanism for holding a lens, and interlocking with the movement of a cam ring to form a cylindrical lens.
Can be moved relative to the other frame in the optical axis direction of the above lens
A cylindrical lens holding frame such, the optical axis direction provided on at least one of the opposing surfaces of the other frame and the lens holding frame
A plurality of parallel linear protrusions or a plurality of point-like protrusions
A reference guide section and a section, and the other frame and the lens holding frame, which includes a biasing member that gives a biasing force in order to abut through the reference guide unit, the lens holding frame Moves without play along the reference guide.

[0017]

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIGS. 1 to 4 are exploded perspective views of a lens barrel to which a lens barrel moving mechanism according to a first embodiment of the present invention is applied. 5 and 6 are longitudinal sectional views of the lens barrel. 5 and 6, the upper half is a cross-sectional view in a zoom wide state, and the lower half is a cross-sectional view in a zoom telephoto state.

The lens barrel of this embodiment is a zoom lens barrel having a four-group configuration. For zooming, the cam ring 3 is rotated by using a stepper (stepping motor) as a drive source, and each lens group holding frame is moved. Move forward and backward. Focusing is performed by a CCD holder 1 for holding a CCD as an image pickup device.
4 itself is driven by an electromagnetic actuator to move forward and backward.

As shown in the above-mentioned perspective view, cross-sectional view, etc., the lens barrel of the present embodiment mainly includes an outer fixed frame 1 which is fixed to the camera body via respective fixed frames described later, and 1 and 2. A so-called “3”, which holds the group lens 41 and is driven forward and backward by the cam groove 3a of the cam ring 3 via the three cam followers 22a.
One group frame 2 which is one of the lens holding frames having the main suspension structure
And cam grooves 3a, 3b, 3 for driving each holding frame.
It has a rotatable cam ring 3 provided with c and 3d, a wave washer 4 for urging the cam ring, and an inner fixed frame 5 fixed to the outer fixed frame 1.

The lens barrel further holds guide shafts 7, 8 for supporting the respective lens frames other than the first group frame 2 and the CCD holder 14 so as to be able to advance and retreat, and a second group lens 42.
A second group frame 9 which is a movable lens holding frame supported by 8
A third group frame 10 which is a movable lens holding frame that holds the third group lens 43 and is supported by the guide shafts 7 and 8;
A fourth group frame 11 which holds the fourth group lens 44 and is movable back and forth supported by the guide shafts 7 and 8;
A yoke 12 constituting an electromagnetic actuator for D drive;
It holds the guide shafts 7, 8 and the rear fixed frame 13 supporting the yoke 12, the CCD 55 of the image sensor and the LPF 54 of the optical low-pass filter, and is supported by the guide shafts 7, 8 and further drives itself back and forth. A CCD holder 14 around which a drive coil 14b constituting an electromagnetic actuator is wound, the LPF 54, the CCD 55, and a rear cover 15 for regulating the axial directions of the guide shafts 7 and 8.
A drive unit for rotating the cam ring and using the stepper 51 as a drive source.

The outer fixed frame 1, the inner fixed frame 5, and the rear fixed frame 1
Reference numeral 3 denotes a state in which the components described below are incorporated, and they are integrally fixed by screws via the respective mounting holes 1a, 5a, and 13a. The relative positioning of the frames 1 and 13 in the rotational direction during the fixing is performed by fitting the positioning pins 1b and 13b into the positioning holes 5b of the inner fixed frame 5.

The first group frame 2 is inserted into the outer fixed frame 1 so as to be able to advance and retreat in a state where the rotation is restricted.
The rotation is restricted by a roller 23 supported by the pins 22 of the first group frame 2 in the linear guide grooves 1j disposed on the inner peripheral portion of the outer fixed frame 1.
Is inserted and regulated. Instead of the roller 23, a boss provided so as to be coaxial with the pin 22 may be used. The first group frame 2 is moved forward and backward during zooming by rotating a cam ring 3 described later.

On the inner peripheral portion of the outer fixed frame 1, convex portions 1d and 1e serving as linear reference guide portions downward in the forward and backward directions are provided.
However, linear convex portions 1f and 1g are provided above. Further, a leaf spring 21 as an urging member is screwed to the mounting portion 1h in the upper opening 1i in the center.

When the first group frame 2 is inserted into the outer fixed frame 1, the first group frame 2 is formed with the convex portions 1 d, 1 e, 1 of the outer fixed frame 1.
Even if there is a fitting play required for f or 1g in terms of mechanism or component accuracy, the first group frame 2 is urged downward by the leaf spring 21 as shown in the sectional view of FIG. , The outer periphery of which comes into contact with the protrusions 1d and 1e without fail. During zooming operation, this state is maintained and the first group frame 2
Moves forward and backward, and this contact state is always maintained in a normal photographing state.

The first plate frame 21 is provided on the first group frame 2.
When an external force greater than the urging force is applied, the outer periphery of the first group frame 2 only moves relatively slightly until it comes into contact with the protrusions 1f and 1g. In addition, by making the inner peripheral contact portion of the outer fixed frame 1 partially convex as described above, the outer periphery of the cam ring 2 is stably contacted, and the contact resistance is further reduced.

The cam ring 3 is rotatably fitted to the inner peripheral portion of the first group frame 2, and the inner fixed frame 5 is further fitted to the inner peripheral portion of the cam ring 3. However, a corrugated washer 4 is inserted into the outer periphery of the inner fixed frame 5, and the corrugated washer 4 connects the flange 3 h of the cam ring 3 to the flange 1 c of the outer fixed frame 1.
Press so as to contact Due to this pressing force, the above 1
The group frame 2 is positioned with respect to the outer fixed frame 1 and the inner fixed frame 5 in the optical axis direction. In addition, the washer 4 is
The groove 4a provided on the inner periphery thereof is inserted in a state of being fitted into the projection 5e of the inner fixed frame 5, and its rotation is regulated.

A portion of the outer periphery of the flange portion of the cam ring 3 is partially cut out, and a gear portion 3i is provided. The gear portion 3i is meshed with a drive gear 34a of a drive unit described later. The section drives the cam ring 3 from the wide position to the tele position.

The wide position corresponds to the position where the closing leaf portion 3j provided on the flange portion is disposed on its rotation locus.
It is detected by an I (photo interrupter) 53. Positioning of each zooming position is performed based on the wide position. The protruding stopper 3k provided on the flange portion of the cam ring 3 is inserted into a stopper groove 1k having both ends provided on the flange portion 1c of the outer fixed frame 1, and is provided on the cam ring 3. It acts as a rotation stopper at the wide end or the tele end. FIG. 7 is a longitudinal sectional view of a main part around the stopper 3k and the groove 1k of the cam ring 3 and the outer fixed frame 1.

There are three cam grooves 3a for the first group frame provided on the outer peripheral portion of the cam ring 3, and the cam followers 22a of the first group frame 2 are slidably fitted into each of them. The first group frame 2
The rotation of the cam ring 3 is restricted, and when the cam ring 3 rotates, it moves forward and backward in the optical axis O direction.

In this case, if there is a margin in the strength against the external force, one of the three cam followers and the cam grooves, particularly the reference guide portions 1d and 1e having a good balance of the force with the urging force of the leaf spring 21. Intermediate cam follower 3a '
(See FIG. 8) and only the corresponding cam groove is operated during the normal zoom operation, and the other two positions are set in the escaped state in the fitted state, and serve as auxiliary roles or are eliminated. It is also possible to get rid of it.

FIG. 8 is a sectional view of the outer fixed frame 1, the first group frame 2, and the cam ring 3 around the cam follower 22a as viewed from the CCD side.

Further, cam grooves 3b, 3c, 3d for the second, third, and fourth group frames are provided in the inner peripheral portion of the cam ring 3, and the second, third, and fourth group frames 9, 10, 11 are provided respectively. The cam followers 9c, 10c, and 11c fixed to the slidably fit. When the cam ring 3 rotates, the holding frame moves forward and backward in the optical axis O direction.

The drive section uses a stepper 51 as a drive source. The rotation of the pinion 31 as an output gear thereof is 2
The power is transmitted from the step gear 32 to the drive gears 34 b and 34 a, and further transmitted to the gear portion 3 i of the cam ring 3. In order to engage the drive gear 34a with the gear portion 3i of the cam ring 3, an escape groove 1m is provided in the flange portion 1c of the outer fixed frame 1.

The drive gears 34b and 34a are integrated via a gear shaft 35. And the shaft 35 is
It is slidably and rotatably inserted into and supported by the elongated hole of the gear box 37. The direction of the slot is two-stage gear 32
The meshing position of the small gear and the drive gear 34b and the cam ring 3
The meshing position between the gear portion 3i and the driving gear 34b is set to a direction that bisects the meshing position. Further, a torsion spring 36 is wound around the gear shaft 35, and urges the shaft 35 in the elongated hole direction. Therefore, the meshing gap between the small gear of the two-stage gear 32 and the driving gear 34b and the meshing gap between the gear portion 3i of the cam ring 3 and the driving gear 34b are simultaneously closed, so that there is no mesh play.

The pinion 31, which is the output gear of the stepper 51, meshes with the shield plate gear 37, and the rotation state of the shield plate gear 37 is detected by the shield plate 36a formed integrally with the gear 37. Is detected by PI52. Then, the step out of the stepper 51 during the zooming drive is detected based on the rotation state of the shield plate gear 37.

The inner fixed frame 5 is provided with supporting holes 5f and 5g for supporting the ends of the guide shafts 7 and 8, into which the ends of the guide shafts 7 and 8 on the subject side are inserted, and the diameter of the guide shafts 7 and 8 is set. It regulates the direction and the axial direction to the subject side. A substantially intermediate portion between the guide shafts 7 and 8 is provided with shaft holes 13 f and 1 of the rear fixing frame 13.
3g, the radial direction is supported by being regulated, and the CCD side end is limited only to the axial position toward the CCD side by the bottomed holes 15f, 15g of the rear cover 15 fixed to the rear portion of the rear fixing frame 13. Is going.

It should be noted that the shaft holes 13f and 1
3g means that the shaft hole 13g is located forward in the optical axis direction.
This is because the front end of g is located forward of the forked portion 14f.

Further, the guide shafts 7 and 8 are
The third group frame 10 and the fourth group frame 11 are slidably supported. That is,
The guide shaft 7 has a bifurcated portion 9f of the second group frame 9, a third group frame 10, 4
The shaft holes 10f, 11f of the group frame 11 are fitted, and the guide shaft 8
The shaft hole 9g of the second group frame 9 and the two forked portions 10g and 11g of the third group frame 10 and the fourth group frame 11 are fitted into the holes. Then, the frames 9, 1
0 and 11 are supported in a state of being housed inside the inner fixed frame 5.

The cam followers 9c, 1 fixed to the second, third, fourth group frames 9, 10, 11 as described above.
0c and 11c penetrate through the inner fixed frame 5 and are slidably fitted into the cam grooves 3b, 3c and 3d of the cam ring 3. The followers 9c, 10c and 11c escape, and the guide shafts 7 and 8 are displaced. The inner fixed frame 5 is provided with openings 5c and 5d along the optical axis O in order to escape the shaft holes and bifurcations of the second, third, fourth and fourth group frames 9, 10, and 11. 9 and 10 show cross sections of the lens barrel viewed from the CCD side around the fitting portions of the second group frame 9 and the third group frame 10, respectively.

One end of a play removing spring 26 is hung on the projection 9 d of the second group frame 9, and the other end of the spring is hung on a projection 5 h inside the inner fixed frame 5. 2 by the urging force
The looseness of the cam follower of the group frame 9 with the cam groove 3b of the cam ring 3 is removed. In addition, the above third and fourth group frame 1
The backlash springs 27 are hung on the projections 10d and 11d of the 0, 11 groups, respectively.
Cam groove 3c, 3d of cam ring 3 for one cam follower
The play of fitting is performed.

The yoke 1 is located on the subject side of the rear fixed frame 13.
2 is fixed to the mounting holes 13c and 13d through the mounting 12a. The yoke 12 is formed of a magnetic material,
A substantially rectangular yoke inner peripheral portion 12b;
Four magnets 16 are mounted on the upper, lower, left, and right sides of the surface facing the outside. The four magnets 16 are mounted parallel to each other along the optical axis.

FIG. 11 is a sectional view showing the relative arrangement and positional relationship between the yoke 12 and the second, third, fourth group frames 9, 10, and 11 as viewed from the CCD side. As shown in this figure, the guide shafts 7, 8 for supporting the second, third, fourth group frames 9, 10, 11 are arranged in a diagonal direction of the yoke 12 and closer to the inner periphery of the yoke. . In this way, the distance between the centers of the guide shafts 7 and 8 is made as small as possible, while the structure is such that the electromagnetic driving force can be obtained to the maximum, thereby achieving the miniaturization of the entire lens barrel.

The rear side of the rear fixed frame 13, that is, the CCD
CCD mounted with LPF 54 and CCD 55 from the side
The holder 14 is inserted, and the two forks 1
It is mounted to be able to advance and retreat through the shaft hole 4g and the shaft hole 14g. The C
A rectangular parallelepiped LPF 5 at the center of the CD holder 14
4 around the outer periphery of the mounting portion, the drive coil 14b
Are wound along the optical axis.

In the assembled state, the drive coil 14b is inserted through a central opening 13h of the rear fixed frame 13 and inserted into a portion surrounded by the inner peripheral portion 12b of the yoke 12 and the magnet 16. Therefore, the drive coil 14b
The CCD holder 14 is controlled by controlling the current flowing through the CCD holder 14.
Can be driven forward and backward. The CCD holder 1
The position 4 is detected by a position sensor (not shown), and the in-focus position of the CCD holder 14 is determined based on the signal.

Next, the driving operation of the lens barrel configured as described above will be described. First, when a power switch (not shown) is turned on, the stepper 51 is driven, and the cam ring 3 rotates to the wide end position which is the reset position, and the first, second, third and fourth group frames 2, 9, 10 are rotated. , 11 to the wide end position. When performing zooming from this state, the stepper 51 is driven, the cam ring 3 is rotated, and the first, second, third, fourth group frames 2, 9, 10, and 11 are moved to the zooming positions.

The CCD holder 1 is controlled by controlling the current of the drive coil 14b of the electromagnetic actuator.
The upper CCD 55 is moved to the zoom tracking position corresponding to the zooming position, and the zooming is completed. When performing focusing, the CCD holder 14 is driven forward and backward by an electromagnetic actuator, and the CCD 55 is moved.
Is moved to the in-focus position.

During the above-mentioned zooming operation or shooting,
Since the outer circumference of the first group frame 2 receives the side pressure by the leaf spring 21 and is pressed downward, the outer circumference of the first group frame 2 is in contact with the protruding portions 1d and 1e extending relatively long along the optical axis direction. The first group lens 41 held by the first group frame 2 does not always have its center optical axis shifted or tilted with respect to the barrel optical axis O. It should be noted that, even when the outer diameter of the first group frame 2 is reduced due to the miniaturization, the effective extension distance of the convex portions 1d and 1e can be secured to a predetermined length. Can be avoided.

At the same time, since the flange 3h of the cam ring 3 is urged by the wave washer 4 and is in contact with the flange 1c of the outer fixed frame 1, the position of the cam ring 3 in the optical axis direction is constant. Is held. Furthermore, the frames 2, 9, 4 and 9, 9
Since positions 0 and 11 are also urged by the backlash removing spring 26 or 27, they are accurately positioned at each zoom position.

As described above, according to the lens barrel of this embodiment, first, when the front end of the first group frame 2 is extended outside during zooming, the first group frame 2 is moved even if an external force acts. Since it has a cylindrical shape and has a strength advantage in spite of being a three-row suspension structure, there is little deformation. In addition, since the first to fourth group frames 2, 9, 10, 11 are movable frames, high magnification,
A wide angle of view can be achieved.

Further, during the zooming operation or during photographing, the first group lens 41 receives a lateral pressure in a predetermined direction, so that the occurrence of tilting with respect to the optical axis O of the lens barrel or displacement of the reciprocating position is extremely small.
The fluctuation of the image and the deterioration of the quality of the photographing screen caused by them are completely eliminated. As in the case of the zoom lens barrel according to the present embodiment, the zoom lens barrel has a large number of groups, and has a configuration in which a lens holding frame is interposed between the cam ring and the outer fixed frame 1. It is not necessary to provide an optical axis direction stopper portion corresponding to the front end surface of the cam ring 3 on the fixed frame, which makes the entire length of the lens barrel longer, so that it can be made compact. Further, even if the lens holding frame is formed of plastic, it is possible to provide a lens barrel that can sufficiently withstand external force from outside and sufficiently secure lens support accuracy.

In the present embodiment, the guide shafts 7, 8 are arranged at short distances in the diagonal direction of the yoke 12 due to the shape of the yoke 12 for the electromagnetic actuator, so that the distance between the centers is made as small as possible. Then, 2, 3, 4 group frame 9,
The spans of the support portions 10 and 11 are shortened. Therefore, the lens barrel can be made compact.
In this embodiment, the stopper 3k is brought into contact with the end of the groove 1k on the flange portion 1c of the outer fixed frame 1 at the wide position and the tele position of the cam ring 3, so that a small occupied space is provided. The stopper structure is housed in the housing.

In this embodiment, the convex portions 1d and 1e serving as linear reference guide portions are provided on the inner peripheral portion of the outer fixed frame 1. The convex portions are driven by the first group frame. It may be provided on the two sides. Further, the linear reference guide portion may be formed by a point-like convex portion.

[0054]

As described above, the lens barrel moving mechanism of the present invention
Since the lens group holding frame was pressed in the lateral direction to prevent the optical axis from tilting and changing, it was applied to, for example, a zoom lens barrel having a high magnification, a wide angle of view, and a large number of lens group frames. Also, it is possible to reduce the occurrence of image shaking or blurring of the screen during zoom operation or shooting. Also,
A biasing means in the optical axis direction is provided to abut the fixed frame and the flange provided on the cam ring, and the cam ring is positioned in the optical axis direction, so that the lens frame is made compact. be able to.

[Brief description of the drawings]

FIG. 1 is a part of an exploded perspective view of a lens barrel to which a lens barrel moving mechanism according to an embodiment of the present invention is applied.

FIG. 2 is a part of an exploded perspective view of the lens barrel shown in FIG. 1;

FIG. 3 is a part of an exploded perspective view of the lens barrel shown in FIG. 1;

FIG. 4 is a part of an exploded perspective view of the lens barrel shown in FIG. 1;

FIG. 5 is a longitudinal sectional view along the optical axis of the lens barrel of FIG. 1;

FIG. 6 is a longitudinal sectional view along the optical axis of the lens barrel of FIG. 1;

FIG. 7 is a sectional view of a main part of a rotation stopper mechanism of a cam ring of the lens barrel of FIG. 1;

FIG. 8 is a sectional view of a surface orthogonal to the optical axis of the outer fixed frame, the first group frame, and the cam ring of the lens barrel of FIG. 1;

FIG. 9 is a sectional view of a plane orthogonal to the optical axis of the inner fixed frame and the second group frame of the lens barrel of FIG. 1;

FIG. 10 is a sectional view of a plane orthogonal to the optical axis of the inner fixed frame and the third group frame of the lens barrel of FIG. 1;

FIG. 11 is a cross-sectional view of a plane orthogonal to the optical axis showing the arrangement of the yoke and the guide shaft of the lens barrel in FIG. 1;

FIG. 12 is a longitudinal sectional view of a zoom lens barrel to which a conventional shaft suspension structure is applied.

FIG. 13 is an exploded perspective view of a main part of a zoom lens barrel to which a conventional helicoid structure is applied.

[Explanation of symbols]

1... Outer fixed frame (fixed frame) 1d, 1e... Convex (reference guide) 2... 1 group frame (lens holding frame) 3... …… Cam ring 3h ………… Flange part provided on cam ring 3i ………… Gear provided on notch of cam ring 3k ……………………… Stopper part 4 …………… Wave washer (biasing member) 21 ………………………… plate spring (biasing member)

Continuation of front page (56) References JP-A-62-47609 (JP, A) JP-A-6-148495 (JP, A) JP-A-3-130708 (JP, A) JP-A-57-179808 (JP) , A) JP-A-63-287833 (JP, A) JP-A-5-297258 (JP, A) JP-A-4-305606 (JP, A) Fully open Showa 55-169503 (JP, U) Really open show 60-92216 (JP, U) Japanese Utility Model Application Showa 61-198913 (JP, U) Japanese Utility Model Application Hei 7-14411 (JP, U) Japanese Utility Model Application Showa 61-112315 (JP, U) (58) Field surveyed (Int. Cl. ⁷ , DB name) G02B ⁷ /02-7/105

Claims (1)

(57) [Claims] A cylindrical lens holding frame which holds a lens and is movable relative to another cylindrical frame in the optical axis direction of said lens in conjunction with the movement of a cam ring. If, the other frame and the lens holding frame at least one parallel multiple in the optical axis direction provided in a linear convex surface facing
Parts, or, a reference guide unit having a plurality of dot-shaped convex portions, and the other frame and the lens holding frame, a biasing member that gives a biasing force in order to abut through the reference guide unit A mirror frame moving mechanism, comprising: