JPH01237607A - Zoom lens driver - Google Patents

Abstract

PURPOSE:To enable easy tracking adjustment at an intermediate focus position by turning a cam around a specific point. CONSTITUTION:An interlock pin 8d of an interlock lever 8 is pressed to a cam face 30a as a moving lens barrel advances and retreats. The pin held pressed to the cam face moves while tracing said face. The intersected point of the normals of the contact QW of the pin 8d and the cam face 30a while the pin exists in the shortest focal length position and the contact QT while the pin is in the longest focal length position is designated as O. Arc-shaped holes 31a, 31b around the intersected point O are formed to a cam plate 30 and since guide pins 32a, 32b are inserted therein, the displacement of the cam plate 30 is the turning motion around the point O. The shape of the cam curve traced by the interlock pin 8d changes when the cam plate 30 turns. The intermediate focus is eventually varied and the adjustment of the intermediate focus is executed. Since the adjustment of only the intermediate focus by the simple operation is thereby enabled, the tracking adjustment operation in a short period of time is possible.

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention is for initial adjustment of the drive cam of a zoom lens, and after adjusting the short focal length side and the long focal length side, tracking at an intermediate focal position is performed. The present invention relates to a zoom lens driving device that allows adjustment.

[Conventional technology]

2. Description of the Related Art There are zoom lenses that can take photographs by continuously changing the focal length by appropriately moving a lens group. 2. Description of the Related Art In recent years, so-called compact cameras have become popular so that photos can be easily taken, and compact cameras with zoom lenses have been developed, which are equipped with zoom lenses.

Conventional zoom lenses of this type are composed of a fixed lens barrel and a movable barrel. For example, in a two-group zoom, the front group lens is fixed to the movable lens barrel, and the rear group lens is supported by the same movable lens barrel. There is a known mechanism in which when a movable lens barrel is displaced relative to a fixed lens barrel, the movable lens barrel moves back and forth in the optical axis direction. Furthermore, there are also types in which the movable lens barrel is moved forward and backward in the optical axis direction while rotating relative to the fixed lens barrel, and types in which the movable lens barrel is moved back and forth in the optical axis direction by sliding within the fixed lens barrel.

In order to continuously change the focal length without shifting the focus on the film plane, it is necessary to move the front group lens and the rear group lens while maintaining a predetermined optical relationship. For this reason, the amount of movement of the front group lens and the amount of movement of the rear group lens are different. In order to create this difference in the amount of movement, a cam device is used that controls the amount of movement of the rear group lens by bringing a pin installed in the mount of the rear group lens into contact with a cam provided on a fixed lens barrel or a movable lens barrel. It is used.

In the lens manufacturing process, errors with respect to design values occur, so when the lens is attached to a camera body, tracking adjustment must be made for the front and rear group lenses so that the lens is focused on the film plane. This tracking adjustment is performed while changing the contact position between the pin and the cam. In other words, tracking adjustment is performed so that the film plane is in focus at the shortest focal length position (hereinafter referred to as the "W position"), and after this adjustment, the lens group is moved to the longest focal length position (hereinafter referred to as the "T position"). Move and adjust tracking. This adjustment process is then repeated several times to bring the focus to the film surface.

[Problem that the invention seeks to solve]

As mentioned above, tracking adjustment is performed by performing adjustment work at the W position and the T position, but with a zoom lens, the front group lens and rear group lens maintain a predetermined optical relationship even at an intermediate position between the W position and the T position. must be maintained. If the cam and pin at the W and T positions are in the designed abutment position, the pin will trace the designed cam surface even at the intermediate position, but the tracking adjustment will cause the W and T positions to change as designed. Since it deviates from the contact position, the focus also deviates at the intermediate position. If the focus at the medium-fine position is not within the tolerance, change the W position and T position again.
Start over from the tracking adjustment with the position, and adjust the W position and T position.
It must be ensured that each focal point at the position and intermediate position is within tolerance.

Such tracking adjustment work is extremely troublesome and requires a considerable amount of time, which impairs work efficiency.

Therefore, an object of the present invention is to minimize the out-of-focus by changing only the intermediate position without changing the W and T positions as much as possible after the tracking adjustment of the W and T positions is completed. It is an object of the present invention to provide a zoom lens driving device which allows easy tracking adjustment at an intermediate focal position.

[Means for solving problems]

In order to achieve the above object, a zoom lens driving device according to the present invention includes a movable lens barrel provided with a fixed lens that moves forward and backward in the optical axis direction, and a movable lens interlocked with the movable lens barrel that drives the fixed lens by a cam device. In a zoom lens that continuously changes the focal length by moving forward and backward in a predetermined relationship, the cam device is composed of a driven member provided on the movable lens and a cam at a fixed position, The cam is characterized by being able to rotate around the intersection of the normal lines of the contact point when the photographing lens is at the shortest focus position and the contact point when the photographic lens is at the longest focus position. It is said that

[For production]

If the focus at the intermediate position is not within the allowable value when the focus adjustment at the W and T positions is completed, the cam is rotated appropriately.

The center of rotation of the cam at this time is the intersection of the normal lines at the points of contact between the driven member and the cam at the W and T positions.
When the rotation angle is small, the contact point can be changed with almost no effect on the short focus and long focus. The cam surface after rotation of the cam and the cam surface before rotation are slightly different. For example, if the front focus was at an intermediate position before rotation, the focal point can be moved rearward. Then, when the focal points at the W position, the T position, and the intermediate position fall within tolerance values, the cam is fixed.

〔Example〕

DESCRIPTION OF THE PREFERRED EMBODIMENTS A zoom lens driving device according to the present invention will be specifically described below based on illustrated embodiments.

First, the structure of the lens drive section of a compact camera equipped with a zoom lens equipped with this drive device will be explained based on FIG.

This zoom lens has a front lens group 1 as a fixed lens.
This is a two-group zoom consisting of the rear lens group 2 and the rear lens group 2 as a moving lens. The front group lens 1 is housed in the shutter unit 3,
This shutter unit 3 is fixed to the front part of the movable lens barrel 4 with three setscrews 3a. In addition, this set screw 3
The inclination of the front group lens 1 in the optical axis direction can be adjusted by interposing spring washers 3b between two of the set screws 3a.

Furthermore, the mechanism for moving the front group lens 1 in the optical axis direction for initial focus adjustment is constructed in the same manner as a conventionally known mechanism. For example, a protrusion protruding in the optical axis direction is provided on the lens mount of the front group lens 1, and an adjustment ring having an uneven cam surface formed on a surface perpendicular to the optical axis is arranged such that the cam surface is always in contact with the protrusion. This is a mechanism for moving the front group lens 1 in the optical axis direction by rotating this adjustment ring.

The movable lens barrel 4 has a substantially rectangular parallelepiped frame-like member with a mounting plate 4a for fixing the shutter unit 3 thereon. A guide hole 4b is provided at the rear of the upper surface of the movable lens barrel 4 by forming a substantially rectangular through hole parallel to the optical axis.
b, by inserting the protrusion 5a formed at the upper end of the lens mount 5 of the rear group lens 2 into the rear group lens 2.
is arranged at the rear of the movable lens barrel 4.

A guide portion 5b is provided by forming a through hole in a direction parallel to the optical axis at the lower side end portion of the lens mount 5, and a bushing 5c is fitted into this guide portion 5b. A rear group guide piece 6a is inserted into this bushing 5c, and the tip end of the rear group guide piece 6a on the side of the movable lens barrel 4 is supported by a support provided inside the movable lens barrel 4. A presser plate 6b is brought into contact with the rear end of the rear group guide bar 6a, and the presser plate 6b is fixed to the movable lens barrel 4 with a set screw 6c. A push spring 6d is wound between the lens mount 5 of the rear group guide rod 6a and the support part in the movable lens barrel 4, and the lens mount 5 transfers its restoring force to the guide hole 4b and the rear group. It is biased so that it is guided by the guide bar 6a and moves rearward.

A suitable recess is formed in the lower surface of the lens mount 5, the eccentric pin 7a of the focus adjustment pin 7 and the flange 7b are fitted into this recess, and the holding plate 7c is fixed to the lens mount 5 with a set screw 7d. By doing so, the focus adjustment pin 7 is fixed to the lens mount 5.

A circular fulcrum pin 7e is formed on the focus adjustment pin 7 fixed to the lens mount 5, and the fulcrum pin 7e is passed through the through hole 7f of the presser plate 7c to connect the interlocking lever 8.
Loosely insert it into the interlocking hole 8a.

The interlocking lever 8 has a substantially triangular shape, and the interlocking hole 8a is formed at the tip of the negative corner. A through hole 8b is formed in the other corner, and a support screw 8c passing through the through hole 8b is tightened to the lower surface of the movable lens barrel 4, and the interlocking lever 8 is centered around the support screw 8c with respect to the movable lens barrel 4. It is installed so that it can be rotated freely. Further, at the tip of the remaining corner of the interlocking lever 8, an interlocking pin 8d protrudes in a direction opposite to the movable lens barrel 4.
is provided as a driven member of the cam device.

A cam portion 9 is provided at the rear side of the movable lens barrel 4 by forming a through hole.

Further, a main guide portion 4c having a through hole formed in the optical axis direction is provided at the side end portion of the upper surface of the movable lens barrel 4, and a bushing 4d is fitted into this main guide portion 4c. A cam plate 10 having a cam surface 10a is fixed to the side of the main guide portion 4c. Note that this cam plate 10 may be made in common with the main guide section 4c, and the cam surface 10a may be formed on the side surface of the main guide section 4c. At the lower part of the side surface of the movable lens barrel 4 opposite to the side surface on which the cam portion 9 is provided, there is provided a sub-guide portion 4e whose tip portion is cut out into a substantially U-shape, as shown by a broken line.

As mentioned above, the front group lens 1, the rear group lens 2. Move the movable lens barrel 4 equipped with the interlocking lever 8 etc. to the camera body A (fifth
(Illustrated) is housed in a fixed frame 11 fixed to At this time,
The main guide bar 4f is inserted into the main guide part 4c, and the support part 11a located above the rear end of the fixed frame 11 supports the rear end of the main guide bar 4f.

Further, the sub-guide bar 4g is inserted into the notch at the tip of the sub-guide part 4e, and its rear end is supported by the support part 11b provided on the inner side surface of the fixed frame 11. And the fixed frame 11
A frame-shaped lid 12 is secured to the front peripheral edge of the housing by tightening with a set screw 12a.

The interlocking pin 8 of the interlocking lever 8 is provided on the lower surface of the fixed frame 11.
A cam plate 3 formed with a cam surface 30a against which the side surface d abuts.
0 is set. In addition, this cam plate 30 and the interlocking pin 8d
The relationship will be explained in detail later.

Further, a worm 14 having a rotation axis in the vertical direction is disposed on the side surface of the fixed frame 11. The rotation axis of this worm 14 is made to protrude above the upper surface of the fixed frame 11, and a drive gear is attached to this protrusion. 15 is fitted. On the upper surface of the fixed frame 11, a gear train 16 including an appropriate number of gears such as a gear 16a and having an appropriate reduction ratio is arranged, and the rotation of a motor (not shown) is transmitted to the drive gear 15 via this gear train 16. . A worm wheel 17 pivotally supported on the side surface of the fixed frame 11 meshes with the worm 14, and a transmission gear 18 is provided coaxially with the worm wheel 17. These worm wheels 1
7 and the transmission gear 18 are mutually rotatable, and by applying an appropriate frictional force between their sides, when the load applied to these gears exceeds a predetermined value, one of the gears stops. However, the other gear is set to idle.

The transmission gear 18 includes an intermediate gear 1 pivotally supported on the fixed frame 11.
9 are in mesh with each other, and a gear for driving an encoder 20 and a fan-shaped gear 21 are in mesh with this intermediate gear 19.

The rotating shaft 21a of the sector-shaped gear 21 passes through a through hole 11c formed on the side surface of the fixed frame 11, and the tip of the rotating shaft 21a is connected to a notch 4 formed at the rear lower end of the movable lens barrel 4.
h and is located inside the movable mirror W44 housed in the fixed frame 11. Then, the base end of the input lever 22 is fixed to the tip of the rotation shaft 21a with a set screw 22a,
This input lever 22 and the fan-shaped gear 21 are designed to rotate in synchronization. A drive pin 22b is provided at the free end of the culver 22 to project toward the fan-shaped gear 21. It is an insert.

The upper surface of the fixed frame 11, and the movable lens barrel 4 accommodated therein.
A through hole lid having a shape corresponding to the cam surface 10a is formed in a portion located substantially above the cam plate IO.

Further, an interlocking plate 23 is provided on the upper surface of the fixed frame 11, and a set screw 2
3a, it is rotatably supported approximately at the center. A downwardly directed engagement pin 23b is protruded from one end of the interlocking plate 23, and this engagement pin 23b passes through the through hole lid and comes into contact with the cam surface 10a of the cam plate 10. . An upwardly directed input pin 23c is protruded from the other end of the interlocking plate 23, and this input pin 23c is interlocked with a magnification change mechanism (not shown) of the finder. Note that the interlocking plate 23 may be pivoted on the camera body A or the finder case.

Next, details of the relationship between the interlocking pin 8d of the interlocking lever and the cam plate 30 will be explained based on FIGS. 1 and 2.

As will be explained in the operation described later, in FIG. 1, the position of the interlocking lever 8 indicated by a solid line is when the photographic lens is in the W position, and the position indicated by a two-dot chain line is when it is in the T position. . As the movable lens barrel 4 moves forward and backward, the interlocking pin 8d is displaced while tracing the cam surface 30a while remaining in contact with the cam surface 30a. In design, the contact point between the interlocking pin 8d and the cam surface 30a when it is in the W position is Q=, and the contact point when it is in the T position is QT, and these contact points Qw, Q? Let the intersection of the normal lines at be ○.

Two arcuate holes 31a and 31b are formed along an arc around the intersection ◯ on the peripheral edge of the cam plate 30, at positions where the center angles are approximately right angles. On the other hand, two guide pins 32a and 32b are provided protruding from the inner surface of the fixed frame 11, and these guide pins 32a and 32b are inserted into the arcuate hole 31a.

31b. Further, on the periphery of the cam plate 30, there is a long hole 30b whose longitudinal direction is approximately in the direction toward the above-mentioned intersection ○.
A female thread 30c is formed at a position appropriately spaced from the cam surface 30a.

A stepped hole 32c whose diameter is reduced on the inside is formed on the bottom surface of the fixed frame 11 at a portion facing the elongated hole 30b, and a stepped hole 32c whose diameter is reduced on the inside is also formed at a portion facing the female screw 30c.
A through hole 32d having a diameter appropriately larger than the diameter of 0c is formed. Furthermore, a seat portion 33a is provided on the outer surface of the fixed frame 11.
A locking pin 33 having a diameter is provided in a protruding manner. Then, as shown in FIG. 2, the stepped hole 32c is opened from the outside of the fixed frame 11.
Then, insert the cam plate adjustment pin 34 having an eccentric pin 34b protruding from a position offset from the center of the flange portion 34a.

The outer diameter of the flange portion 34a of the cam plate adjustment pin 34 is approximately equal to the inner diameter of the large diameter portion of the stepped hole 32c, and the flange portion 34a is rotatable within the large diameter portion.
A part of it protrudes from the outer surface of the fixed frame 11. Further, the eccentric pin 34b projects inside the fixed frame 11 and is inserted into the elongated hole 30b of the cam plate 30. A groove 34c is formed on the lower surface of the flange 34a to receive the tip of a screwdriver or the like.

Further, a leaf spring 35 is fixed to the outer surface of the fixed frame 11 with a set screw 36, but this set screw 36
The through hole 35a formed approximately in the center of 5 and the through hole 32
d and is screwed into the female screw 30c of the cam plate 30.

One end of the leaf spring 35 is formed with a locking hole 35b into which the locking pin 33 protruding from the outer surface of the fixed frame 11 is inserted, and the other end is formed with a locking hole 35b into which the locking pin 33 protruding from the outer surface of the fixed frame 11 is inserted. A working hole 35c having a smaller diameter than the outer diameter of the flange portion 34a is formed at a position where the flange portion 34a faces.

The operation of the zoom lens driving device according to the present invention constructed as described above will be explained together with the movement operations of the front group lens 1 and the rear group lens 2.

When the motor (not shown) rotates, the drive gear 15 rotates via the gear train 16, and the worm 14 rotates.

When the worm 14 rotates, the worm wheel 17 meshed with the worm 14 rotates, and the frictional force between the worm wheel 17 and the worm wheel 17 causes the transmission gear 18 to rotate. This transmission gear 1
8 is transmitted to the fan-shaped gear 21 via the intermediate gear 19, and the fan-shaped gear 21 rotates in the direction of arrow P in FIG. 4 about the rotation axis 2La. Note that the rotation of the motor when rotating the fan-shaped gear 21 in this direction is assumed to be forward rotation.

When the sector gear 21 rotates, the input lever 22 coaxially with the sector gear 21 swings in the same direction in synchronization. Therefore, the drive pin 22b of the input lever 22 rotates in the same direction as the sector gear 21 around the rotation shaft 21a. This rotation of the drive pin 22b pushes the cam portion 9, and the drive pin 22b moves from the upper end of the cam portion 9 to the lower end. Therefore, the movable lens barrel 4, which forms the cam part 9, is guided by the main guide part 4c and the auxiliary guide part 4g, and moves forward with respect to the fixed frame 11.
That is, it moves toward the subject. A shutter unit 3 including a front lens group 1 is fixed to the front part of the movable lens barrel 4, and the front lens group 1 also moves forward.

When the movable lens barrel 4 moves forward, the interlocking lever 8 that is pivotally supported by the movable lens barrel 4 also moves in the same way. The interlocking pin 8d of the interlocking lever 8 is connected to the cam surface 30 of the cam plate 30 provided on the fixed frame 11.
a, when the interlocking lever 8 moves forward with respect to the fixed frame 11, the interlocking lever 8 is guided by the cam surface 30a and rotates counterclockwise in FIG. 5 about the support screw 8C. do. On the other hand, since the lens mount 5 of the rear group lens 2 is linked to the interlocking lever 8 via the focus adjustment pin 7, the lens mount 5 is moved against the restoring force of the push spring 6d by rotation of the interlocking lever 8. It moves forward with respect to the movable lens barrel 4. Therefore, the rear group lens 2 moves forward with respect to the movable lens barrel 4, narrowing the distance from the front group lens 1, and changing the focal length continuously. Moving lens barrel 4
When the lens moves to the frontmost position, the front group lens 1 and the rear group lens 2 are positioned at the frontmost position, the rear group lens 2 is closest to the front group lens 1, and the focal length becomes the longest. Further, the drive pin 22b is located at the lower end of the cam portion 9, and the tip of the movable lens barrel 4 is in a position protruding from the fixed frame 11. Note that in order to ensure the optical positional relationship between the front group lens 1 and the rear group lens 2 when zooming, the cam surface 30a is
It is only necessary to design the cam curve so that it has a predetermined cam curve.

To move the movable mirror w44 backward from the state where the drive pin 22b is located at the lower end of the cam portion 9 and the movable lens barrel 4 is located at the frontmost position, a motor (not shown) may be rotated in the reverse direction. Since the sector gear 21 rotates in the opposite direction of arrow P in FIG. 4 due to the reverse rotation of the motor, the drive pin 22b also rotates in the same direction. Therefore, contrary to the above, the movable lens barrel 4 is attached to the fixed frame 11.
Retreat while being accommodated.

A push spring 6 is used to keep the lens mount 5 always moving backwards.
d, and the interlocking lever 8 receives a force to rotate clockwise in FIG.
It is in contact with 0a. Therefore, the interlocking pin 8d is guided by the cam surface 30a and rotates clockwise in FIG. 5 about the support screw 8c. Therefore, the fulcrum pin 7e also rotates in the same direction, and the lens mount 5 retreats with respect to the movable lens barrel 4.

As a result, the rear group lens 2 moves backward, and in cooperation with the retreat of the front group lens 1 accompanied by the movable lens barrel 4, the focal length is continuously changed to the shortest distance.

When initially adjusting the focal length, the fulcrum pin 7e of the focus adjustment pin 7 is rotated with the rear lens group 2 at a temporarily determined position relative to the interlocking lever 8.

As a result, the eccentric pin 7a moves the lens mount 5 in the optical axis direction, so that the focus can be adjusted by moving the rear group lens 2 in the optical axis direction. After the focus has been appropriately adjusted in this manner, the set screw 7d is tightened to press the presser plate 7c against the focus adjustment pin 7 and fix it.

Once the position of the rear group lens 2 has been determined as described above and the tracking adjustment at the W and T positions of the photographing lens has been completed, it is confirmed whether the focal point at the intermediate position is within a tolerance value. If it is within the range, the tracking adjustment work ends at that point.

If the intermediate focus is not within the tolerance, the groove 3 of the cam plate adjustment pin 34 is removed from the working hole 35c of the leaf spring 35.
Insert the tip of a screwdriver or the like into 4c to rotate the cam plate adjustment pin 34. This causes the eccentric pin 34b to
, the cam plate 30, in which the eccentric pin 34b is inserted into the elongated hole 30b, is displaced.

The cam plate 30 has an arcuate hole 3 formed around the intersection 0.
1a and 31b, and guide pins 32a and 31b are formed thereon.
32b is inserted, the above displacement of the cam plate 30 is a rotational movement about the intersection O. Note that when the cam plate 30 rotates, the set screw 36 moves within the through hole 32d.

When the cam plate 30 rotates, the shape of the cam curve traced by the interlocking pin 8d changes, so the intermediate focal point differs before and after the cam plate 30 is rotated.

By utilizing this difference, the intermediate focus can be adjusted.

The center of rotation of the cam plate 30 when performing this tracking adjustment is the intersection point O of the normal lines of the contact point Qw and the contact points Q and r, so when the cam plate 30 is slightly rotated, it is at the W position. The focal point at the T position hardly changes, so the rotation of the cam plate 30 can be adjusted by changing only the intermediate focal point. In addition, when adjusting the tracking of short focus and long focus, the contact point between the interlocking pin 8d and the cam surface 30a is the designed contact point QwtQ? Although they do not necessarily match, they do not deviate significantly, so even when the cam plate 30 is rotated, the focal point at each position is well within the allowable value.

In particular, as shown in FIG. 3, the cam surface 30a is arranged so as to cross the optical axis 20th position of the rear group lens when it is at the angle θ1 and the T position @
Angle θ between the straight line connecting V and the interlocking pin 8d and the optical axis X
It is preferable to make the values equal to each other, because when the cam plate 30 is rotated, the deviation of the intermediate focal point will be distributed between the front and back and will be kept within the allowable value.

After tracking adjustment has been performed in this manner, tighten the set screw 36. Since the seat portion 33a of the locking pin 33 and the head of the flange portion 34a of the cam plate adjustment pin 34 abut on both ends of the leaf spring 35, a gap is created between the leaf spring 35 and the fixed frame 11. Therefore, when the set screw 36 is tightened,
As shown in FIG. 2, the central portion of the leaf spring 35 is bent to accumulate restoring force. Therefore, the cam plate 30 is fixed in close contact with the fixed frame 11.

In this embodiment, a telephoto type zoom lens in which the front group lens 1 and rear group lens 2 move forward to create a long focal point has been described, but this is also a retrofocus type zoom lens in which each lens group moves backward to create a long focal point. I don't mind.

〔Effect of the invention〕

As explained above, according to the zoom lens driving device according to the present invention, the cam is rotated about the intersection of the normal lines at the respective contact points of the driven member and the cam at the short focus position and the long focus position. Therefore, even if the cam is rotated after adjusting the short and long focal points, if the rotation angle is small, the short and long focal points will hardly change. In addition, since the cam curve changes as the cam rotates, the focal point at the intermediate position between the short focus position and the long focus position can be changed either forward or backward. That is, after adjusting the short focus and long focus, only the intermediate focus can be adjusted with a simple operation, which has the effect of improving work efficiency and making it possible to perform tracking adjustment work in a short time.

Moreover, since the number of parts is small and the structure is simple, the camera does not need to be made large or its weight increases, and this does not hinder the reduction in size and weight of the camera.

[Brief explanation of the drawing]

The drawing shows an embodiment in which the drive device according to the present invention is used in a compact camera with a zoom lens. 1st
The figure is an exploded perspective view of the main parts of the drive device, Figure 2 is a sectional view taken along the line ■-■ in Figure 1, and Figure 3 is a plan view showing the location of the cam in relation to the optical axis. be. FIG. 4 is an exploded perspective view of a zoom lens equipped with a drive device, and FIG. 5 is a partial cross-sectional view taken along a horizontal line with a movable lens barrel housed in a fixed frame. 1... Front group lens (fixed lens) 2... Rear group lens (movable lens) 4... Movable lens barrel 5... Lens mount 8
...Interlocking lever 8a...Interlocking hole 8b...
Through hole 8c...Support screw 8d...Interlocking pin (driven member) 11...Fixed frame 3o...Cam plate 30a
...Cam 30b...Long hole 30c...
Female thread 31a, 31b...Circular hole 32a
, 32b...Guide pin 32c...Stepped hole 32d
...Through hole 33...Lock pin 33a...
・Seat portion 34...Cam plate adjustment pin 34a
...Flange part 34b...Eccentric pin 35...
・Plate spring 35a...Through hole 35b...Latching hole 35c...Working hole 36...Set screw A...Camera body ○...Intersection Qw, QT・
...Contact patent applicant Fuji Photo Kohki Co., Ltd. Figure 1 Figure 2 7J13

Claims (1)

[Claims] A movable lens barrel provided with a fixed lens moves forward and backward in the optical axis direction, and a movable lens linked to the movable lens barrel moves forward and backward in a predetermined relationship with the fixed lens by a cam device, thereby adjusting the focal length. In a zoom lens that changes continuously, the cam device is composed of a driven member provided on the moving lens and a cam at a fixed position, and the point of contact between the driven member and the cam is such that the photographing lens is at the shortest focus position. A zoom lens driving device characterized in that the cam is rotatable around the intersection of normal lines at the contact point when the lens is at the maximum focus position and the contact point when the contact point is at the longest focal position.