JPH087314B2 - Camera with zoom lens - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a camera with a zoom lens equipped with a zoom lens capable of continuously changing a focal length by obtaining power from a motor.

[Conventional technology]

2. Description of the Related Art There is a zoom lens capable of taking a photograph by continuously changing the focal length by appropriately moving the lens group. In recent years, so-called compact cameras have become widespread so that a photograph can be taken easily, and a compact camera with a zoom lens in which a zoom lens is attached has been developed.

The conventional driving mechanism for this type of zoom lens is a double lens barrel in which the outer lens barrel is fitted to the inner lens barrel, one lens barrel is fixed to the camera body, and the other lens is rotatable around the optical axis. By rotating the other lens barrel, the lens group is moved in the optical axis direction.

That is, a linear groove along the optical axis is formed on either the inner lens barrel or the outer lens barrel, and a spiral cam groove corresponding to the number of lens groups is formed on the other lens barrel, and each lens group is formed. The pins planted in the mount are inserted into both the straight groove and the respective cam grooves. Then, when one of the lens barrels is rotated, the pin is guided in both the linear groove and the cam groove, so that the linear groove moves the moving direction and the cam groove restricts the moving distance to move the lens group. . The movement of this lens group changes the focal length.

The lens barrel is rotated by the power of a motor or manually, and this rotation advances and retracts in the optical axis direction. Moreover, even if an attempt is made to move the lens barrel forward and backward without rotating the lens barrel, it does not move forward or backward due to the structure in which the pin for guiding the lens group is loosely inserted in the linear groove and the cam groove. .

[Problems to be solved by the invention]

However, when the lens barrel is protruding, the lens barrel may be damaged or deformed when the camera is inadvertently dropped or struck and external force is applied to the lens barrel from the outside. There is. Therefore, the deformed portion or the damaged portion becomes an obstacle, and the lens barrel cannot be retracted, and thereafter, it becomes impossible to perform photographing at the position where the lens barrel is retracted. Further, when an external force is applied in the optical axis direction to pull out the lens barrel, the cam groove is deformed, and an appropriate zooming operation cannot be performed.

Therefore, when a force is applied to the lens barrel in the optical axis direction, it is desirable to prevent the lens barrel from moving back and forth to prevent damage and deformation of the lens barrel and internal parts.

By the way, since a compact camera is provided with an automatic exposure and auto-focus mechanism, the focal length at the time of shooting must be detected in a camera equipped with a zoom lens. Therefore, it is necessary to detect the position of the lens barrel at the time of shooting with an encoder or the like. Further, it is necessary to change the magnification of the viewfinder so that the subject can be visually recognized at a magnification corresponding to the focal length of the photographing lens.

Therefore, even when the lens barrel moves due to an external force, the encoder and the finder need to be displaced according to the movement.

Therefore, this invention is always driven by a motor,
An object of the present invention is to provide a camera with a zoom lens provided with a lens barrel that can be moved in the optical axis direction by an external force when it is carelessly applied.

[Means for solving problems]

In order to achieve the above-mentioned object, a camera with a zoom lens according to the present invention is a camera with a zoom lens in which a lens barrel holding a photographing lens is moved forward and backward in the optical axis direction by rotation of a motor to continuously change a focal length. In the power transmission path from the motor to the lens barrel, a one-way transmission element that allows transmission of power from the motor to the lens barrel and is a large load for transmission of power from the lens barrel to the motor is provided. A power transmission element for transmitting power via frictional force is provided in a power transmission path from the one-way transmission element to the lens barrel to allow the lens barrel to move back and forth in the optical axis direction by an external force. The viewfinder interlocking member that displaces as the lens barrel advances and retracts, and the viewfinder zooming mechanism interlocks with the encoder interlocking member that displaces as the lens barrel advances and retracts. It is characterized.

[Work]

When the motor rotates, the lens barrel moves in the optical axis direction to change the focal length. The magnification of the finder changes in conjunction with the advance / retreat of the lens barrel, the position of the lens barrel is detected by the encoder, and the exposure is performed according to the focal length.

When an external force is intentionally or carelessly applied to the lens barrel, the external force causes the lens barrel to move in the optical axis direction, and the finder and the encoder operate in conjunction with this movement. The external force applied to the lens barrel tries to be transmitted from the lens barrel to the motor through the power transmission path, but since the one-way transmission element is provided in this power transmission path, the one-way transmission element is provided. Becomes a load against the external force, and slippage occurs between the power transmission elements via the frictional force.

Therefore, in either case, when the lens barrel is moved by the motor or when the lens barrel is moved by an external force, normal photographing can be performed.

〔Example〕

Hereinafter, a camera with a zoom lens according to the present invention will be specifically described based on the illustrated embodiments.

FIG. 1 shows the structure of a lens driving unit of a compact camera equipped with a zoom lens in which a lens group moves.

This zoom lens is a two-group zoom including a front group lens 1 and a rear group lens 2. The front lens group 1 is housed in a shutter unit 3, and the shutter unit 3 is fixed to the front part of the movable lens barrel 4 by three setscrews 3a. In addition,
Of the setscrews 3a, two setscrews 3a have spring washers.
The inclination of the front lens group 1 in the optical axis direction can be adjusted by interposing 3b.

The movable lens barrel 4 has a shape in which a mounting plate 4a for fixing the shutter unit 3 is formed on a substantially rectangular frame member. A guide hole 4b is formed in the rear of the upper surface of the movable lens barrel 4 in a substantially rectangular shape in parallel with the optical axis to provide a guide hole 4b.
Then, the rear group lens 2 is arranged at the rear portion of the movable lens barrel 4 by inserting the protrusion 5a formed on the upper end portion of the lens mount 5 of the rear group lens 2.

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 bush 5c is fitted to the guide portion 5b. The rear group guide rod 6a is inserted through the bush 5c, and the tip of the rear group guide rod 6a on the side of the movable lens barrel 4 is supported by a support portion provided in the movable lens barrel 4. A pressing plate 6b is brought into contact with the rear end of the rear group guide rod 6a, and the pressing plate 6b is fixed to the movable lens barrel 4 by a set screw 6c. A pushing spring 6d is wound between the lens mount 5 of the rear group guide rod 6a and the above-mentioned supporting portion in the movable lens barrel 4, and the restoring force of the pushing spring 6d is adjusted by the lens mount 5 to the guide hole 4b and the rear group. It is urged to move backward by being guided by the guide rod 6a.

Form an appropriate depression on the lower surface of the lens mount 5,
The eccentric pin 7a of the focus adjustment pin 7 and the flange are in this recess.
7b and the pressing plate 7c is fixed to the lens mount 5 with a set screw 7d to fix the focus adjustment pin 7 to the lens mount 5. A circular fulcrum pin 7e is formed on the focus adjusting pin 7 fixed to the lens mount 5, and the fulcrum pin 7e is passed through the through hole portion 7f of the pressing plate 7c to form the interlocking hole 8a of the interlocking lever 8. Insert loosely.

The interlocking lever 8 is substantially L-shaped, and the interlocking hole 8a is formed at the tip of one arm portion thereof. A through hole 8b is formed in the substantially L-shaped bent portion, and a supporting screw 8c penetrating the through hole 8b.
Is fastened to the lower surface of the movable lens barrel 4, and the interlocking lever 8 is provided on the movable lens barrel 4 so as to be rotatable around the support screw 8c. In addition, at the tip of the other arm of the interlocking lever 8,
Interlocking pin projecting in the direction opposite to the movable lens barrel 4
8d is provided.

A through hole is formed in the rear side surface of the movable lens barrel 4 to form a cam portion 9
Is provided.

Further, a main guide portion 4c having a through hole formed in the optical axis direction is provided at a side end portion of the upper surface of the movable lens barrel 4, and a bush 4d is fitted into the main guide portion 4c. A cam plate 10 having a cam surface 10a is fixed near the side of the main guide portion 4c. In addition,
The cam plate 10 may be common to the main guide portion 4c, and the cam surface 10a may be formed on the side surface of the main guide portion 4c. As shown by a broken line, a sub-guide portion 4e having a U-shaped tip is cut out 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.

As described above, the movable lens barrel 4 on which the front lens group 1, the rear lens group 2, the interlocking lever 8 and the like are mounted is housed in the fixed frame 11 fixed to the camera body A (shown in FIG. 7). At this time,
The main guide rod 4f is inserted into the main guide portion 4c, and the rear end portion of the main guide rod 4f is supported by the support portion 11a above the rear end portion of the fixed frame 11. Further, the auxiliary guide bar 4g is inserted into the notch at the tip of the auxiliary guide portion 4e, and the rear end portion is supported by the support portion 11b provided on the inner side surface of the fixed frame 11. Then, the frame-shaped lid body 12 is fastened and fixed to the front peripheral edge of the fixed frame 11 with the set screw 12a.

As shown in FIGS. 1 and 7, a cam hole 13 having a cam surface 13a is provided on the lower surface of the fixed frame 11, and the side surface of the interlocking pin 8d of the interlocking lever 8 contacts the cam surface 13a. .

Further, a worm 14 having a rotation axis in the vertical direction is arranged on the side surface of the fixed frame 11, and the rotation axis of the worm 14 is projected above the upper surface of the fixed frame 11, and the drive gear is attached to this projection. I am wearing 15. On the upper surface of the fixed frame 11, a gear train 16 having an appropriate reduction ratio, which is composed of an appropriate number of gears such as a gear 16a, 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 combination of the worm 14 and the worm wheel 17 constitutes a one-way transmission element. This worm wheel
A transmission gear 18 is provided coaxially with 17. The worm wheel 17 and the transmission gear 18 are rotatable relative to each other, and by applying an appropriate frictional force between these side surfaces, when the load applied to these gears exceeds a predetermined magnitude,
One gear is stopped and the other gear is idle.

2 to 4 show details of the power transmission system in the meantime.

FIG. 3 is a front cross-sectional view with a part cut away. As shown in FIG. 3, the transmission gear 18 is integrally formed with a boss portion 18a extending long to the right. A bearing 36 is provided at the end of the boss portion 18a, and the bearing 36 is attached to a bracket 37 fixed to the fixed frame 11. Further, a journal portion 18b is formed on the opposite side of the transmission gear 18 from the boss portion 18a, and the journal portion 18b is formed.
Is loosely inserted in the bearing portion provided on the fixed frame 11, and the transmission gear 18
Is rotatable with respect to the fixed frame 11.

The worm wheel 17 is loosely fitted to the boss portion 18a of the transmission gear 18 so that the worm wheel 17 and the transmission gear 18 can rotate relative to each other, and the worm wheel 17 slides axially with respect to the transmission gear 18. Be free to move. The end surface of the boss portion 17a of the worm wheel 17 faces the bearing 36, and the push spring 38 is wound around the boss portion 17a. The restoring force of the push spring 38 causes the worm wheel 17 to continuously transmit the gear.
Side of worm wheel 17 and bearing 36 so that it presses against 18
It is urged between and.

As shown in FIG. 4, ridges 39 are radially formed on the respective surfaces of the worm wheel 17 and the transmission gear 18 which are opposed to each other, and both sides of the ridges 39 are inclined surfaces 39a and 39b. The inclined surface 39a is a gentle slope and the inclined surface 39b is a steep surface. The gentle slope 39a of the worm wheel 17 and the gentle slope 39a of the transmission gear 18 face each other, and the worm wheel 17 and the transmission gear 1
The eight steep slopes 39b face each other.

Further, the worm 14 and the worm wheel 17 are configured such that the rotation of the motor (not shown) is transmitted from the worm 14 to the worm wheel 17 and the worm wheel 17 is rotated by appropriately adjusting the number of threads and the lead angle. The worm wheel 14 acts as a load to prevent the worm wheel 17 from rotating when trying to rotate.

An intermediate gear 19 as an encoder interlocking member axially supported by the fixed frame 11 meshes with the transmission gear 18, and a gear 20a for driving the encoder 20 and a sector gear 21 are engaged with the intermediate gear 19.
And are in mesh.

As shown in FIG. 1, the rotary shaft 21a of the fan-shaped gear 21 penetrates through a through hole 11c formed in the side surface of the fixed frame 11, and the tip end of the rotary shaft 21a is located behind the movable lens barrel 4. The movable lens barrel 4 housed in the fixed frame 11 through the notch 4h formed at the lower end.
Located inside. Then, the base end portion of the input lever 22 is fixed to the tip end portion of the rotating shaft 21a by the set screw 22a,
The input lever 22 and the fan gear 21 are rotated in synchronization with each other. At the free end of this input lever 22 is a fan gear
A drive pin 22b is provided so as to be oriented in the direction of 21, and the drive pin 22b is loosely inserted in the cam portion 9 formed on the side surface of the movable lens barrel 4.

The movable lens barrel 4 which is the upper surface of the fixed frame 11 and is accommodated in the fixed frame 11.
The portion of the cam plate 10 located substantially above the cam plate 10 has a cam surface
A through hole 11d having a shape corresponding to 10a is formed. In addition, an interlocking plate as a finder interlocking member is provided on the upper surface of the fixed frame 11.
The set 23 is rotatably supported by a set screw 23a at substantially the center thereof. An engaging pin 23b directed downward is projected from one end of the interlocking plate 23, and a restoring force of a spring is urged so that the engaging pin 23b penetrates the through hole 11d and the cam plate 10b. Is always in contact with the cam surface 10a. An input pin 23c directed upward is provided at the other end of the interlocking plate 23 so as to project upward, and the input pin 23c is interlocked with a variable magnification mechanism (not shown) of the finder 40.

As shown in FIGS. 5 and 6, the finder 40 is disposed above the camera body A and substantially above the fixed frame 11. An objective lens 41 composed of a convex lens 41a and a concave lens 41b is provided in front of the finder 40, and a reflecting mirror 42, a field frame 43, and an eyepiece lens 44 are provided behind the concave lens 41b. FIG. 5 shows a state at the time of standard photographing, in which the movable lens barrel 4 is retracted, and the concave lens 41b of the objective lens 41 is used.
Is in front and is close to the convex lens 41a. 6 shows a state at the time of telephoto shooting, in which the movable lens barrel 4 moves forward, the rear lens group 2 moves forward with respect to the movable lens barrel 4 and approaches the front lens group 1, and the concave lens 41b retracts. Convex lens 4
It is located almost in the middle between 1a and the reflecting mirror 42. When the shooting lens continuously changes the focal length from the standard position to the telephoto position, the concave lens 41
As shown in FIG. 5, b gradually retreats away from the position close to the convex lens 41a, leaving a state as shown in FIG.
This kind of zooming operation is performed with the input pin 23c and concave lens 4
This is accomplished by a mechanism for converting the rotational movement of the interlocking plate 23 into the linear movement of the concave lens 41b by interposing a link mechanism with the 1b or by using a pinion rack or the like. The interlocking plate 23 may be pivotally supported on the camera body A or the case of the finder 40.

The operation of the camera with a zoom lens according to the present invention configured as described above will be described below.

When a motor (not shown) rotates, the drive gear 15 rotates via the gear train 16 and the worm 14 rotates. Warm 14
When the worm rotates, the worm wheel 17 meshed with the worm rotates, and the frictional force between the worm wheel 17 and the worm wheel 17 causes the transmission gear 18 to rotate. The rotation of the transmission gear 18 is the rotation of the intermediate gear 19
It is transmitted to the fan-shaped gear 21 via the rotary shaft 21a, and the fan-shaped gear 21 rotates about the rotation shaft 21a in the arrow P direction in FIG. In addition,
The rotation of the motor when the fan gear 21 is rotated in this direction is defined as forward rotation.

When the fan-shaped gear 21 rotates, the input lever 22 that is coaxial with the fan-shaped gear 21 synchronously swings in the same direction. Therefore, the drive pin 22b of the input lever 22 turns in the same direction as the fan gear 21 about the turning shaft 21a. The cam portion 9 is pushed by the turning of the drive pin 22b, and the drive pin 22b moves from the upper end portion to the lower end portion of the cam portion 9. Therefore, the movable lens barrel 4 forming the cam portion 9 is guided by the main guide rod 4f and the sub guide rod 4g to move forward with respect to the fixed frame 11, that is, toward the subject side. A shutter unit 3 including the 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 mirror movement 4 advances, the interlocking lever 8 pivotally supported by the movable mirror movement 4 also moves. Since the interlocking pin 8d of the interlocking lever 8 is in contact with the cam surface 13a of the cam hole 13 formed in the fixed frame 11, when the interlocking lever 8 moves forward with respect to the fixed frame 11, the interlocking lever 8 moves to the cam surface 13a. It is guided to rotate counterclockwise in FIG. 7 about the support screw 8c. On the other hand, since the lens mount 5 of the rear group lens 2 is connected to the interlocking lever 8 via the focus adjustment pin 7,
The rotation of the interlocking lever 8 moves the lens mount 5 forward with respect to the movable lens barrel 4 against the restoring force of the push spring 6d.
Therefore, the rear lens group 2 moves forward with respect to the movable lens barrel 4, and the interval between the rear lens group 2 and the front lens group 1 is narrowed, so that the focal length is continuously changed. When the movable lens barrel 4 moves to the forefront, the front lens group 1 and the rear lens group 2 are located at the forefront, the rear lens group 2 comes closest to the front lens group 1, and the focal length becomes the longest. . Also, drive pin 22b
Is located at the lower end of the cam portion 9, and the tip of the movable lens barrel 4 is located at a position protruding from the fixed frame 11. In order to secure the optical positional relationship when the front lens group 1 and the rear lens group 2 perform zooming, the cam curve of the cam surface 13a may be designed to have a predetermined cam curve.

In order to retract the movable lens barrel 4 from the state in which the drive pin 22b is located at the lower end 9c of the cam portion 9 and the movable lens barrel 4 is located at the forefront, a motor (not shown) may be rotated in reverse. . Since the fan gear 21 rotates in the direction indicated by the arrow P in FIG. 1 by 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 retracts while being accommodated in the fixed frame 11.

The lens mount 5 is a push spring so that it always moves backward.
Since the interlocking lever 8 receives the restoring force of 6d and the clockwise rotation in FIG. 7 via the focus adjusting pin 7, the interlocking pin 8d receives the force of the cam surface 13a.
Is in contact with Therefore, the interlocking pin 8d becomes the cam surface 13a.
7 and is rotated clockwise around the support screw 8c in FIG. Therefore, the fulcrum pin 7e also turns in the same direction, and the lens mount 5 retracts with respect to the movable lens barrel 4.
As a result, the rear lens group 2 retreats, and in cooperation with the retreat of the front lens group 1 accompanying the movable lens barrel 4, the focal length is continuously changed to the shortest distance.

The rotation of the intermediate gear 19 for moving the movable lens barrel 4 back and forth is
Since it is also transmitted to the gear 20a of the encoder 20, the encoder 20 operates according to the movement of the movable lens barrel 4. Moving lens barrel 4
Since the encoder 20 also stops when is stopped, the position instructed becomes the stop position of the movable lens barrel 4, and the exposure at the time of shooting is controlled based on this instructed value.

As the movable lens barrel 4 advances and retracts as described above, the interlocking plate 23 in which the engagement pin 23b is in contact with the cam surface 10a of the cam plate 10 rotates. The direction of rotation of the interlocking plate 23 is opposite when the movable lens barrel 4 moves forward and when it moves backward. The rotation of the interlocking plate 23 is transmitted to the concave lens 41b via a zooming mechanism (not shown) composed of a link or the like, and as described above, this moves backward when the movable lens barrel 4 moves forward, and when it moves backward, it moves forward. To do. By moving the concave lens 41b back and forth, the magnification of the finder 40 is continuously changed according to the focal length of the photographing lens.

Then, with the movable lens barrel 4 protruding from the fixed frame 11,
When an external force is inadvertently applied to the lens barrel by dropping or hitting the camera carelessly, the moving lens barrel 4 is retracted by this external force and the sector gear 21 is rotated in the direction of arrow P in FIG. Move. This rotation of the sector gear 21 rotates the intermediate gear 19, and this rotation is transmitted to the transmission gear 18. On the other hand, the worm wheel 17, which is engaged with the transmission gear 18 by the inclined surfaces 39a and 39b, is meshed with the worm 14, which is a load, so the worm wheel 17 does not rotate. Therefore, the force applied to the worm wheel 17 by the rotation of the transmission gear 18 resists the restoring force of the push spring 38 and thus the worm wheel 17.
17 slides to the right in FIG. By this sliding, the engagement between the worm wheel 17 and the inclined surfaces 39a, 39b of the transmission gear 18 is released. When the ridge 39 of the worm wheel 17 gets over the ridge 39 of the transmission gear 18, the restoring force of the push spring 38 causes the worm wheel 17 to slide leftward in FIG. Engage. In this way, the inclined surfaces 39a, 39b
Repeatedly engaged and disengaged, and the transmission gear 18 became the worm wheel 17
To idle against. Therefore, the retraction of the movable lens barrel 4 is allowed by the external force. When the worm wheel 17 slides, since the tooth traces of the worm 14 and the worm wheel 17 are twisted, they are guided by the tooth traces and rotate slightly.

Further, even when the moving lens barrel 4 which is retracting is inadvertently pulled out, the rotation of the sector gear 21 due to the forward movement of the moving lens barrel 4 is transmitted to the transmission gear 18 and rotates, but the worm wheel 17 Since it does not rotate, the transmission gear 18 idles and the forward movement of the movable lens barrel 4 is allowed.

When the movable lens barrel 4 is advanced or retracted by the rotation of a motor (not shown), the movable lens barrel 4 is stopped when the movable lens barrel 4 is positioned at the forward end or the backward end, or when the forward or backward movement of the movable lens barrel 4 is obstructed. Therefore, when the transmission gear 18 does not rotate, the worm wheel 17 idles with respect to the stopped transmission gear 18 even if the motor continues to rotate, and does not damage other power transmission elements or the like.

In this embodiment, the worm wheel 17 and the transmission gear 18
Although the mountain portion 39 is formed on the surface facing each other, the surfaces are made flat, a material having an appropriate friction coefficient is used, the contact area is made appropriate, and the elastic coefficient of the pressing spring 38 is made appropriate. Worm wheel 17 and transmission gear 18
The rotation may be transmitted to and from.

On the other hand, the gear 20a of the encoder 20 also rotates due to the rotation of the intermediate gear 19 due to the external force. The rotation of the gear 20a causes the encoder 20 to operate, and the instruction of the encoder 20 after the operation at this time is that the movable lens barrel 4 moved by an external force.
Will be the stop position.

Further, since the interlocking plate 23 rotates even when the movable lens barrel 4 moves back and forth due to an external force, the concave lens 41 of the finder 40
b moves back and forth. Moreover, as in the case of driving the movable lens barrel 4 by the motor, the concave lens 41b is stopped at a position having a magnification corresponding to the focal length at the stop position of the movable lens barrel 4, and thereafter the movable lens barrel 4 is normally operated by the motor. No trouble occurs when driving.

When the movable lens barrel 4 moves back and forth, the cam plate 10 and the interlocking plate 23
A reaction force is generated by the engagement with. Due to this reaction force, the movable lens barrel 4 tends to tilt from the optical axis in an attempt to rotate about the main guide portion 4c, but since the cam surface 10a is near the main guide portion 4c, the reaction force has almost no influence. Without moving, the movable lens barrel 4 moves back and forth. Such a self-lock can be reliably prevented by forming the cam surface 10a on the side surface of the main guide portion 4c, and the movable lens barrel 4 can be moved back and forth more smoothly.

〔The invention's effect〕

As described above, according to the camera with a zoom lens according to the present invention, since the lens barrel is movable in the optical axis direction by an external force, the lens barrel moves when the camera is dropped or hit. Since the external force is absorbed, it is possible to prevent the lens barrel from being damaged or deformed or the internal parts from being damaged.

Further, since the zooming operation of the finder and the operation of the encoder are linked to the forward / backward movement of the lens barrel, even when the lens barrel is moved by an external force, as in the case of driving the lens barrel by the motor,
The magnification of the finder changes and the subject can be visually recognized at a magnification corresponding to the focal length, and the encoder detects the position of the lens barrel and indicates the focal length at that position to control exposure and the like. Therefore, there is an effect that the safety of the operation of the lens barrel and other parts of the camera is improved.

[Brief description of drawings]

FIG. 1 is an exploded perspective view of an embodiment of the zoom lens of the camera with a zoom lens according to the present invention. FIG. 2 is a side view showing a main part of a power transmission system for driving the lens barrel. FIG. 3 is a front sectional view in which the same is partly cut. FIG. 4 is a partially omitted perspective view of one transmission element constituting the power transmission system. 5 and 6 are side sectional views of a compact camera with a zoom lens, FIG. 5 shows a standard photographing state, and FIG. 6 shows a telephoto photographing state. Seventh
The figure is a partial cross-sectional view taken along a horizontal line in a state where the movable mirror is housed in a fixed frame. 1 ... Front group lens, 2 ... Rear group lens 3 ... Shutter unit, 4 ... Moving lens barrel 9 ... Cam part, 10 ... Cam plate 10a ... Cam surface, 11 ... Fixed frame 15 ... Drive gear, 14 ... worm gear 17 ... worm wheel, 18 ... transmission gear 19 ... intermediate gear (encoder interlocking member) 20 ... encoder, 21 ... fan-shaped gear 22 ... input lever 23 ... interlocking plate (finder Interlocking member) 23b …… engagement pin, 23c …… input pin 40 …… finder, 41 …… objective lens 41b …… concave lens, 41a …… convex lens A …… camera body

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kazuhiko Onda 1-324 Uetakecho, Omiya-shi, Saitama Fuji Photo Optical Co., Ltd. (72) Inventor Kiyotaka Kobayashi 2-26-30 Nishiazabu, Minato-ku, Tokyo Fuji (56) References JP-A-58-198030 (JP, A) JP-A-61-63827 (JP, A) Actual development 61-101733 (JP, U) Actual public Sho-45-13923 (JP, Y1)

Claims (1)

[Claims] 1. A camera with a zoom lens for continuously changing a focal length by advancing and retracting a lens barrel holding a photographing lens by rotation of a motor in a power transmission path from the motor to the lens barrel. A unidirectional transmission element that allows the transmission of power from the motor to the lens barrel and is a large load for the transmission of power from the lens barrel to the motor, and the power transmission from the unidirectional transmission element to the lens barrel By providing a power transmission element that transmits power via frictional force in the path,
It allows the lens barrel to move back and forth in the optical axis direction by an external force, and the viewfinder interlocking member that is displaced in conjunction with the movement of the lens barrel is linked with the zooming mechanism of the finder to displace it in conjunction with the movement of the lens barrel. A camera with a zoom lens, characterized in that an encoder is interlocked with the encoder interlocking member.