JP2000206590A - Finder lens driving mechanism for camera - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a finder lens driving mechanism having a small-sized cam plate so as to miniaturize a camera more by driving a finder lens by rotating a cam plate by centering the center of curvature of the cam plate eccentric to the optical axis of a fixed lens barrel. SOLUTION: The cam plate surface radius RB of the cam plate 21 is set as a radius having a eccentric position lowered from the zooming lens axis 5 of the fixed lens barrel 4 at whose center of curvature a zoom lens lens barrel is assembled by an eccentric quantity B as the center of curvature, and the finder lens is driven by rotating the cam plate 21 by centering at the center of curvature. Then, the moving feasible range of the cam plate 21 is set as a range R2 which is larger than a conventional range, so that the angle of a cam groove in which the finder lens is moved against the moving direction of the cam plate 21 is set smaller. Thus, the finder lens is smoothly moved, and the cam plate of the finder lens is miniaturized so as to miniaturize the camera more.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a finder lens driving mechanism of a camera with a built-in zoom lens for moving a finder lens in accordance with a movement of a zoom lens barrel.

[0002]

2. Description of the Related Art In general, when a zoom lens is incorporated in a compact camera of a lens shutter system, the finder must naturally be a zoom finder in which the field of view of the finder changes in conjunction with a change in the photographing magnification of the zoom lens. . As the optical system, a finder optical system having a relatively simple lens configuration, for example, as shown in FIG. 1A is used.

In FIG. 1A, the zoom finder optical system includes finder lenses 11, 12, 13, and 14.
Is formed as a real image on the incident surface 161 of the prism 16 by bending the field image by 90 ° by the mirror 15, and the formed real image is viewed through the eyepiece 17. Then, the finder lenses 11, 1
Reference numeral 4 denotes a fixed lens, which is a zoom finder in which the magnification of a finder image changes by changing the position in the optical axis direction while changing the distance between the finder lenses 12 and 13.

In order to change the position in the optical axis direction while changing the distance between the finder lenses 12 and 13,
A cam plate 21 is used as shown in FIG. The cam plate 21 has a cam groove 2 for changing the position in the optical axis direction while changing the distance between the finder lenses 12 and 13.
11 and 212 are provided. Viewfinder lens 1
The projections of the finder lens 12 enter the cam grooves 211, the projections of the finder lens 13 enter the cam grooves 212, and the cam plate 21 moves in the left and right directions indicated by arrows. Viewfinder lens 1
The cam grooves 211 and 212 move in the right and left directions shown by the arrows in the figure, respectively, and change their positions in the optical axis direction while changing the distance between the finder lenses 12 and 13.

Here, first, a conventional example according to the first invention will be described with reference to FIG.

Although the cam plate 21 is shown in a plan view in FIG. 1B, the zoom lens barrel is provided with a zoom lens barrel as shown in FIG. The cam plate 21 is configured to be accommodated in a space along the cylindrical portion on the upper surface of the fixed lens barrel 4 incorporated therein, and the cam plate 21 is slidably moved on the lens barrel sliding surface on the fixed lens barrel 4 by a driving source. Has become.

Next, a conventional example according to the second invention will be described with reference to FIG. 3. FIG. 3 (a) is a sectional view of a lens barrel and a finder in which the zoom lens is omitted below the optical axis when the zoom lens is wide-angle. (B) is a plan view of the cam plate and its periphery, (c)
FIG. 4 is a cross-sectional view of the lens barrel and the finder above the optical axis of the zoom lens when the zoom lens is telephoto, and FIG. 4D is another cross-sectional view when the zoom lens is wide-angle.

In FIG. 3, the cam barrel 4C1 of the lens barrel is rotatable about the optical axis 5 of the zoom lens, and the cam barrel 4C1 helicoidally fitted to the fixed lens barrel 4 is
The lens barrel 4C2, which is extended with respect to the fixed lens barrel 4 by the rotation of C1 and is also helicoidally fitted to the cam barrel 4C1.
3C can be extended to the cam barrel 4C1, and the telephoto state shown in FIG. 3C can be obtained. If the cam cylinder 4C1 is reversed, the wide angle state shown in FIG. 3A can be obtained.

A pin 45, which is a projection mounted on a ring 46, which is rotatably mounted on the cam cylinder 4C1 and which does not rotate even when the cam cylinder 4C1 rotates, but moves only straight.
Move along a straight groove 44 parallel to the optical axis 5 of the zoom lens provided on the fixed lens barrel 4 and move rightward in the figure as shown by the extension of the zoom lens. Then, as shown in FIG. 3C, when the zoom lens is at the telephoto position, the pin 45 has advanced to the right end of the straight groove 44. At this time, the tips of the fixed lens barrel 4 and the cam plate 21 of the camera are covered with the projection 181 of the finder cover 18.

Next, a conventional example according to the third invention is shown in FIG.
As will be described with reference to (b), the cam plate 21 is guided by a guide ridge 43 for guiding the cam plate 21 so that the zoom lens optical axis 5
The guide is driven in the vertical direction with respect to the arrow. That is, the cam plate 21 is inserted into a linear cam plate drive groove 214 indicated by a dotted line provided on the back surface of the cam plate 21 and the cam cylinder 4C1.
The pin 45 which moves linearly by the rotational movement of
The cam plate 21 is driven in the vertical direction indicated by the arrow.

[0011]

First, the problems relating to the first invention will be described.

1 and 2, when the finder lenses 12, 13 are driven by the cam plate 21 to constitute a zoom finder as described above, the finder lenses 12, 13 are smooth, light, and easily. Preferably, it is driven. If the finder lenses 12 and 13 are not driven smoothly and lightly, the finder image will not be smoothly enlarged / reduced, but will be a jerky enlarged / reduced image.

As described above, the direction of the arrow of the cam plate 21 (FIG. 1)
Since the pins of the finder lenses 12, 13 in the cam grooves 211, 212 are moved in the direction perpendicular to the direction of the arrow (in the direction of the optical axis of the finder lenses 12, 13) by the movement shown in FIG. As the groove direction of the groove is as parallel to the cam plate moving direction as possible, in other words, as the angle between the cam groove direction and the cam plate moving direction is smaller,
The finder lens can move smoothly and with a small force.

However, in order to move the finder lens by a predetermined distance, it is necessary to increase the moving distance of the cam plate as the angle between the direction of the cam groove and the moving direction of the cam plate decreases. That is, it is desired that the movable range R1 of the cam plate can be increased.

On the other hand, a notch 41 is provided on the inner surface of the fixed barrel 4 as a guide groove for moving the zoom lens straight along the optical axis 5 of the zoom lens. The protrusion outside the outer periphery of the body 4 prevents the movable range R1 of the cam plate 21 from increasing. Of course, if the dimension of the cam plate surface radius RA is increased and the radius is set so as to go over the notch 41, the movable range R1 of the cam plate 21 can be increased.
Naturally, the height of the lens barrel is increased by the size obtained by increasing the dimension of the cam plate surface radius RA, so that the height of the camera is also increased and the camera is enlarged.

The first aspect of the present invention has been made to solve the above problems. That is, it is an object of the present invention to provide a finder lens driving mechanism for driving a finder lens smoothly, lightly, and easily without increasing the size of a camera.

Next, the problem relating to the second invention will be described.

In FIG. 3, the tip of the cam plate 21 driven by the pin 45 when the zoom lens is in the telephoto state is covered with the projection 181 of the finder cover 18 as described above. Of course, the zoom finder at that time is a telephoto finder, and the field light L of the telephoto finder
Neither 2 nor the field of view light L1 of the finder at the time of wide angle is removed. However, when trying to reduce the height of the camera by slightly lowering the finder optical system, as shown in FIG. 3D, the height of the camera (in this case, the height of the camera is shifted from the zoom lens optical axis 5 to the finder cover). H4 is the height up to the uppermost surface of 18).
Although it is smaller than the height H3 of the camera shown in (a) and (c), the field light L1 of the finder at the time of wide angle is shaded by the projection 181 of the finder cover 18.

The second invention has been made to solve the above-mentioned problems. That is, it is an object of the present invention to provide a finder lens driving mechanism that can be a small-sized camera without a zoom finder being shaken.

Next, the problem relating to the third invention will be described.

In a camera having a built-in photographing lens of a zoom lens, the zoom ratio of the zoom lens is increasing year by year. As the zoom ratio of the taking lens increases, the zoom ratio of the zoom finder naturally also increases. As the zoom ratio of the zoom finder increases, the size of the cam plate for moving the finder lens constituting the zoom finder in conjunction with the zoom ratio of the photographing lens increases. That is, the movement of the zoom lens of the photographing lens having a large zoom ratio inevitably increases, the movement of the finder lens of the zoom finder associated therewith also increases, and the cam plate for moving the finder lens also increases accordingly. .

Therefore, it is necessary to reduce the size of the camera without increasing the size of the cam plate in order to prevent the size of the camera from increasing and to reduce the size of the camera.

The third invention has been made to solve the above-mentioned problems. That is, it is an object of the present invention to provide a finder lens driving mechanism having a small cam plate without increasing the size of the camera plate of the finder lens in order to prevent the camera from becoming large and to reduce the size of the camera.

[0024]

The object of the present invention is achieved by adopting the following constitution.

That is, according to the structure of the first invention, the zoom lens barrel incorporated in the fixed lens barrel of the camera moves.
In a finder lens driving mechanism for a camera for moving a finder lens, a cam plate for moving the finder lens has an R surface, and the center of curvature of the R surface is an optical axis of a fixed lens barrel in which the zoom lens barrel is incorporated. A finder lens driving mechanism for a camera, wherein the finder lens is moved by rotating the cam plate about the center of curvature of the eccentric R surface.

Further, according to the second aspect of the present invention, the zoom lens barrel incorporated in the fixed lens barrel of the camera moves.
In a finder lens driving mechanism of a camera for moving a finder lens, the camera is guided to a cam plate driving groove provided on a cam plate for moving the finder lens and to a rectilinear groove parallel to an optical axis of a zoom lens provided on the fixed lens barrel. By engaging a projection provided on the zoom lens barrel, and moving the projection along a straight groove parallel to the optical axis of the zoom lens,
The cam plate is driven in a direction substantially perpendicular to the optical axis of the zoom lens, and the projection is detached from the cam plate at a telephoto end of the cam plate driving groove.

Further, according to the third aspect of the present invention, the zoom lens barrel incorporated in the fixed lens barrel of the camera moves.
In a finder lens driving mechanism of a camera that moves a finder lens, a cam plate that moves the finder lens moves a projection provided on the zoom lens barrel to move the cam plate in the optical axis direction of the zoom lens barrel. A finder lens driving mechanism for a camera, wherein a guide for moving in a direction other than a right angle and a cam plate driving groove are provided.

[0028]

Next, an embodiment of the first invention will be described in detail with reference to FIGS.

FIG. 4 is a front view of a fixed lens barrel for explaining the present embodiment. FIG. 5 is an exploded perspective view of a finder section around a fixed lens barrel for explaining the present embodiment.

4 and 5, the radius RB of the cam plate surface of the cam plate 21 is reduced by the amount of eccentricity B at the center of curvature with respect to the zoom lens optical axis 5 of the fixed lens barrel 4 in which the zoom lens barrel is incorporated. The eccentric position is defined as a radius having a center of curvature, and the cam plate 21 is rotated about the center of curvature to drive the finder lenses 12 and 13. By doing so, the cam plate 21 avoids the notch 41 as shown in the figure, and the movable range extends to the position where the cam plate 21 hits the main body wall as shown in the figure. The range R1 can be increased from the range R1 to the movable range R2 of the present embodiment.

That is, the movable range of the cam plate 21 is defined as R1
To R2, the angle between the cam grooves 211 and 212 for moving the finder lenses 12 and 13 and the moving direction of the illustrated arrow of the cam plate 21 can be made gentler. 13 can be moved smoothly, lightly and easily.

Here, the cam plate 21 and the finder lens 1
The movement and driving of the motors 2 and 13 will be further described.

In FIG. 5, a lens barrel gear base plate 42 is mounted on the side surface of the fixed lens barrel 4, and a motor 30 having a gear 31 mounted thereon is installed on the lens barrel gear base plate 42. Are gears 32, 33, 34, 35, 3
6, 37 are sequentially meshed with each other to form a gear train. The last gear 37 meshes with a zoom lens gear (not shown) to perform a zoom operation of a zoom lens barrel (not shown) incorporated in the fixed lens barrel 4. or,
A gear 341 that meshes with the cam plate gear 213 of the cam plate 21 is attached to the tip of the shaft of the gear 34 in the middle.

On the other hand, in the cam groove 211 of the cam plate 21, the lens pin 121 of the finder lens 12 is fitted.
The lens pin 131 of the finder lens 13 is inserted into the finder lens, and the cam plate 21 is rotated and slidably moved left and right along a lens barrel sliding surface 401 having the same radius as the cam plate 21 above the fixed lens barrel 4. Lenses 12 and 13 have cam grooves 211 and
By means of 12, it is possible to move in a direction perpendicular to the right and left rotational sliding movement.

Therefore, by driving the motor 30, the zoom operation of the zoom lens is performed, and at the same time, the cam plate 21 is rotated and slid right and left by the gear 341 to drive the finder lenses 12 and 13, thereby driving the zoom finder. The zoom operation will be performed.

The above is the description of the cam plate 21 and the finder lens 1.
The description of the movement and drive of the zoom lens 2 and 13 will be described. By decentering the cam plate 21 for moving and driving the finder lenses 12 and 13 as described above, the zoom lens light of the fixed lens barrel 4 is adjusted. The height H2 from the shaft 5 to the upper surface of the cam plate 21 is the same as the height H1 from the optical axis 5 of the zoom lens of the fixed lens barrel 4 to the upper surface of the cam plate 21 shown in FIG. Therefore, the height of the camera does not change.

That is, the finder lens can be moved smoothly, lightly and easily without changing the height of the camera and without increasing the size of the camera. And
In the description of the invention, the number of finder lenses that move is described as two, but the number of finder lenses is not necessarily limited to two and may be any number.

Further, by using the above-described finder lens driving mechanism for a zoom finder lens when a zoom lens having a higher zoom ratio is used, a zoom finder having a higher zoom ratio can be easily obtained. Is possible. The cam plate 21 may be driven by a pin drive described in the second and third aspects of the present invention, in addition to the gear drive described above.

Next, an embodiment of the second invention will be described in detail with reference to FIG.

FIG. 6 is a diagram for explaining the present embodiment.
(A) is a sectional view of a lens barrel and a finder in which a portion below a zoom lens optical axis is omitted when the zoom lens is wide-angle, (b) is a plan view of a cam plate and its periphery when the zoom lens is telephoto,
(C) is a sectional view of the lens barrel and the finder above the optical axis of the zoom lens when the zoom lens is telephoto.

In FIG. 6, a portion indicated by a dotted line provided on the back surface of the cam plate 21 is a cam plate driving groove 214, and the telephoto end thereof is open. That is, as in the case of the conventional example described with reference to FIG. 3, the zoom operation from the wide angle to the telephoto is performed by the user so as to be rotatably attached to the cam barrel 4C1 of the lens barrel around the zoom lens optical axis 5, and The pin 45, which is a projection that is implanted in the ring 46 that does not rotate itself but moves only in a straight line even when the 4C1 rotates and that slides in the cam plate driving groove 214 of the cam plate 21, is provided on the fixed lens barrel 4. It moves along the straight groove 44 parallel to the optical axis 5 of the zoom lens in the right direction of the arrow shown in the figure according to the operation of extending the zoom lens. As shown in the figure, when the zoom lens is in telephoto mode, the pin 4
5 moves to the right end of the straight groove 44. That is, FIG.
In (b), the cam plate 21 is fully driven in a direction perpendicular to the optical axis direction movement of the zoom lens barrel in the upward direction of the arrow in the figure, and the pin 45 comes out of the telephoto side end of the cam plate drive groove 214 and the cam plate. 21 and move to the illustrated position.

In other words, the zoom lens barrel according to the present embodiment has a first position where the pin 45 is separated from the cam plate 21 at the telephoto end of the cam plate drive groove 214 at the non-telephoto position. The zoom lens has a second position further extended from the first position to a telephoto position, and the finder lens is at a telephoto position at the first position of the zoom lens barrel.

As described above, when the zoom lens barrel is in the first position, that is, when the pin 45 is at the telephoto end which is the end of the cam plate driving groove 214, the zoom lens barrel has not reached the telephoto position. The field of view of the viewfinder shows the field of view at telephoto. Further, when the pin 45 separates from the cam plate drive groove 214 and the zoom lens barrel moves to the end, the zoom lens barrel is located at the telephoto position, that is, the second position. When the zoom lens barrel is located at the telephoto position, the pin 45 is separated from the cam plate drive groove 214 at the telephoto end, which is the end of the cam plate drive groove 214, and the cam plate is Because it is not moving, it maintains the telephoto view when it leaves.

In this embodiment, the pins 4
5 is located under the protrusion 181 of the finder cover 18, but the right side of the cam plate 21 has a narrow width which is not below the protrusion 181 of the finder cover 18.
Is not under the projecting portion 181 of the finder cover 18, and the projecting portion 181 is
Can be lowered to a position shown in the drawing, which does not hinder the movement of the object. That is, the height of the camera (the height of the camera in this case is the height from the optical axis 5 of the zoom lens to the top surface of the finder cover 18 as described in the conventional example) H4 is the height of the camera described in the conventional example. Although it is lower than the height H3, the protrusion 181 of the finder cover 18 is formed.
In the case of (2), the zoom lens does not emit the field light L1 at the time of wide angle, and the cam plate 21 is further reduced, so that the camera can be reduced in size accordingly.

In the present invention, the cam plate 21 is used for a zoom finder lens when a zoom lens having a larger zoom ratio, for example, a zoom ratio of about 2 times, such as 3 times or 4 times, is used as a photographing lens. Since it is not necessary to increase the ratio as much as the ratio increases, the effect applied to a camera with a high zoom ratio is more effective in preventing the camera from becoming larger.

The relationship between the position of the zoom lens barrel and the field of view of the finder in the present embodiment is, as described above, at the first position where the zoom lens barrel has not yet reached the telephoto position. The field of view of the finder already shows the telephoto field, and is not exactly the same as the focal length of the lens barrel. However, the difference is small, and even if the photographer stops the zoom lens barrel at this first position, checks the shooting area in the viewfinder view, and shoots the subject, the viewfinder view is taken. The difference from the area is negligible.

Further, even in the case of a zoom camera, a zoom camera in which a zoom lens is stopped in a stepwise manner, that is, a zoom lens in which the zoom lens is stopped in a plurality of predetermined steps so that photographing can be performed only at a focal length at the stopped position. By adopting the above configuration in the camera, it is possible to perform shooting without making the photographer recognize the above-mentioned problem.

That is, when a part of the plurality of stop positions is set, the stop is not made at the first position, but before and after the stop position (for example, the non-telephoto position having a shorter focal length than the first position and the first position).
If the camera is set to stop at a telephoto position where the focal length is longer than the position (1) and the photographing is performed, and the focal length of the zoom lens and the field of view of the finder at that time are adjusted at the front and rear positions, the first The zoom lens barrel does not stop at the position, and the focal length of the zoom lens and the viewfinder's field of view at the stop position before and after that position match, so there is a slight difference between the viewfinder's field of view and the imaged area. A small-sized camera can be achieved without the above-mentioned problem of occurrence of the problem.

In FIG. 6B, the cam plate drive groove 2
The telephoto side end of 14 is a cam groove with a groove end 214E having a widening. By adopting such a shape, when zooming the zoom lens from the telephoto side to the wide angle side,
The pin 45 can be easily inserted into the cam plate drive groove 214 by sliding engagement. Also, this cam plate 21
In the illustrated position where is telephoto, a click spring 216 attached to the camera body to maintain the state is used.
The V groove 215 of the cam plate 21 is locked as shown. Accordingly, by doing so, the cam plate 21 is always positioned at this position during telephoto, so that the pin 45 easily enters the cam plate drive groove 214,
If the pin 45 enters the cam plate drive groove 214, the cam plate 2
1 moves in the downward direction of the arrow with the leftward movement of the pin 45, the V groove 215 of the cam plate 21 is released from the click spring 216, and the cam plate 21 moves the lens of the zoom finder to the wide angle side. Become.

Next, an embodiment of the third invention will be described in detail with reference to FIG.

FIGS. 7A and 7B are views of a cam plate for explaining the present embodiment. FIG. 7A is a plan view of a conventional cam plate as a comparative example for explaining the present invention, and FIG. FIG. 9C is a plan view of a cam plate to be described, and FIG. 10C is a plan view of the cam plate to explain another embodiment.

In FIG. 7B, the cam plate 21N1 is provided in the cam barrel of the lens barrel described with reference to FIG. 6 (not shown in FIG. 7). The projections 45 of the lens barrel that move in a direction parallel to the axis are the same as those shown in FIG. 6). The movement of the pins 45 described in FIG. 6 causes the cam plate 21N1 to move the zoom lens barrel. It is driven in the direction of the arrow shown in the figure by the guide ridge 43N and the straight cam plate drive groove 214N for guiding the movement in a direction other than the direction perpendicular to the optical axis direction.

Since the cam plate 21N1 is driven by the cam plate drive groove 214N, the occupied area including the movement occupied by the cam plate 21N1 is smaller than the occupied area including the movement occupied by the conventional cam plate 21. Yes. That is, the cam plate 21 of the conventional example is rectangular, but the cam plate 21N1 of the present embodiment is rhomboid. And the cam plate 21N1
Moves at an angle θ with respect to the conventional cam plate 21. Accordingly, the finder lens moved by the cam grooves 211N and 212N has a movement obtained by adding the movement due to the inclination angle θ. Therefore, the cam plate 21N1 is
The smaller the area is, the smaller the occupied area including the movement is. Therefore, other components and members can be arranged by the reduced size, and the camera can be downsized accordingly.

FIG. 7C shows that a cam plate gear 213N is provided at the end of the cam plate 21N2 instead of the cam plate driving groove 214N, and the cam plate 21N2 is driven by a gear 341 driven by a power source (not shown). Things. Note that it is also possible to drive with the gear 341 described with reference to FIG.

[0055]

According to the first aspect of the present invention, the zoom finder lens can be smoothly moved without increasing the size of the camera.
A finder lens drive mechanism that is light and easily driven has been provided. Further, by using the finder lens driving mechanism of the present invention for a zoom finder lens when a zoom lens having a larger zoom ratio is used, a zoom finder having a higher zoom ratio can be easily obtained. It has become possible.

Further, according to the second aspect of the present invention, a finder lens driving mechanism that can be used as a compact camera without a zoom finder being provided is provided. Further, the present invention can be easily applied to a zoom finder lens when a zoom lens having a larger zoom ratio is used.

According to the third aspect of the present invention, the cam plate of the finder lens is prevented from becoming large in order to increase the zoom ratio of the zoom lens, and the cam plate of the finder lens is reduced in order to further reduce the size of the camera. Finder lens driving mechanism to be provided.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of a zoom finder optical system and a cam plate.

FIG. 2 is a front view of a fixed lens barrel of the conventional camera according to the first invention.

FIG. 3 is a sectional view mainly showing a lens barrel and a finder of a conventional camera according to the second and third inventions.

FIG. 4 is a front view of a fixed lens barrel for describing an embodiment according to the first invention.

FIG. 5 is an exploded perspective view of the periphery of a fixed lens barrel and a finder section for explaining the embodiment according to the first invention.

FIG. 6 is a sectional view of a lens barrel, a finder, and a plan view of a cam plate for explaining an embodiment according to the second invention.

FIG. 7 is a plan view of a cam plate for explaining an embodiment according to a third invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Finder lens drive mechanism 11, 12, 13, 14 Finder lens 21, 21, N1, 21N2 Cam plate 211, 212 Cam groove 213, 213N Cam plate gear 214, 214N Cam plate drive groove 4 Fixed lens barrel 401 Lens barrel sliding surface 4C1 Cam cylinder 43, 43N Guide jetty 44 Straight running groove 45 Pin 5 Zoom lens optical axis B Eccentricity H1, H2, H3, H4 Height L1 Viewing light at wide angle R1, R2 Movable range RA, RB Cam plate surface radius

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G02B 7/04 E

Claims (5)

[Claims] 1. A finder lens driving mechanism for moving a finder lens with a movement of a zoom lens barrel incorporated in a fixed lens barrel of a camera, wherein a cam plate for moving the finder lens has an R surface. The center of curvature of the R surface is decentered with respect to the optical axis of the fixed lens barrel in which the zoom lens barrel is incorporated, and the cam plate is rotated about the center of curvature of the decentered R surface. A finder lens driving mechanism for a camera, wherein the finder lens is moved by moving the finder lens. 2. A cam plate provided on a cam plate for moving said finder lens in a finder lens driving mechanism of a camera for moving a finder lens with movement of a zoom lens barrel incorporated in a fixed lens barrel of the camera. A projection provided on the zoom lens barrel guided by a rectilinear groove parallel to the optical axis of the zoom lens provided on the fixed lens barrel is engaged with the drive groove, and the projection moves straight in a direction parallel to the optical axis of the zoom lens. A finder lens for a camera, wherein the cam plate is driven in a direction substantially perpendicular to the optical axis of the zoom lens by moving along the groove, and the projection is separated from the cam plate at a telephoto end of the cam plate driving groove. Drive mechanism. 3. The zoom lens barrel is located at a non-telephoto position, and the projection is separated from the cam plate at a telephoto end of the cam plate driving groove, and further from the first position. 3. The zoom lens system according to claim 2, further comprising a second position extended to a telephoto position, wherein the finder lens is at a telephoto position at a first position of the zoom lens barrel.
6. The finder lens driving mechanism of the camera according to 4. 4. The cam groove according to claim 2, wherein the cam groove where the projection separates from the cam plate at the telephoto end of the cam plate driving groove is a widened cam groove. Camera viewfinder lens drive mechanism. 5. A finder lens driving mechanism of a camera for moving a finder lens in accordance with a movement of a zoom lens barrel incorporated in a fixed lens barrel of the camera, wherein a cam plate for moving the finder lens includes a zoom lens. A finder lens drive for a camera, wherein a guide and a cam plate drive groove are provided for moving the cam plate in a direction that is not perpendicular to the optical axis direction movement of the zoom lens barrel by moving a projection provided on the lens barrel. mechanism.