JPH1184208A - Camera provided with zoom lens - Google Patents

Abstract

PROBLEM TO BE SOLVED: To facilitate assembly and repair by supporting a 1st lens group holding frame which holds a 1st lens group by the use of a 2nd lens group holding frame which holds a 2nd lens group and providing a helicoid for advancing/retreating by threading on the 2nd lens group holding frame. SOLUTION: Relating to the 2nd lens group holding frame 4; the 2nd lens group LF2 , in the front group lens of a zoom lens is held on its inner periphery, and is pressed from the rear by a lens holding plate 5 consisting of a thin plate being a 2nd lens group holding member. Then, a male helicoid 4a is provided by threading on the outer periphery of the frame 4, and is screwed with the female helicoid 2c of a cam barrel 2. The 1st lens group holding frame 6 holding the 1st lens group LF1 in the front group lens is arranged in front of the frame 4, and is fixed on the frame 4 in a state that a shutter blade 7 used also as a diaphragm is put between the frames 4 and 6. Therefore, the blade 7 and the frame 6 are attached/detached in a state that the frame 4 is still attached to a zoom lens barrel.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a camera with a zoom lens provided with a two-group zoom lens.

[0002]

2. Description of the Related Art Conventionally, many cameras with a zoom lens having a two-group zoom lens are commercially available. As a zoom lens, a front lens having a positive refractive power and a zoom lens having a negative refractive power are provided. A so-called telephoto type, which includes a rear group lens, is generally used. In this configuration, zooming is performed while changing the distance between groups between the front group lens and the rear group lens.

[0003] In most zoom lenses of cameras, a shutter blade also serving as an aperture is disposed between a front group lens and a rear group lens. By using such a telephoto type zoom lens, the overall length of the lens is shorter than the length of the focal length, and this has contributed to miniaturization of the camera.

In addition, a zoom lens having a structure in which the distance between the front lens group and the rear lens group is reduced, the front lens group is separated into a first lens group and a second lens group, and shutter blades are disposed therebetween. Cameras are also commercially available, but also in this case, the distance between the first lens group and the second lens group is constant,
At the time of zooming, the distance between the groups between the front lens group and the rear lens group is changed as described above. This zoom lens has the advantage that the distance between the shutter blade position and the front lens, which is the lens closest to the subject, is short, so that the diameter of the front lens is also small, and a short and thin lens barrel can be realized. . In addition, since the error sensitivity of the lens becomes large in order to shorten the distance between the front lens group and the rear lens group, it is not suitable for the long focal length lens, but is suitable for the short focal length lens. It is very suitable for a camera using an APS film that requires only a short time.

There are many cameras having a lens cover in front of the photographing lens. Conventionally, in addition to the lens cover, a lens cover base for pivotally supporting the rotating lens cover, and opening and closing the lens cover by rotating. At least a lens covering or the like is provided. These are arranged in the order of the lens cover ring, the lens cover, and the lens cover base from the photographing lens side.

Further, the lens barrel holding the zoom lens by electric power is moved out of the retracted position most retracted to the film side through a non-photographing area in which photographing is not performed, to a photographing area in which photographing is performed. 2. Description of the Related Art There is known a camera with a zoom lens which is divided into a plurality of small areas and a lens barrel stops at an initial position of a predetermined small area by a zooming operation.

In such a conventional camera, a signal for determining the initial position of the small area in the photographing area is output at regular intervals, and a zoom position switch for outputting the same signal in the non-imaging area is also provided. A collapsible switch for turning on or off at a predetermined position in the photographing area and a power switch for starting position control of the lens barrel have been provided. When the lens barrel is in the retracted position,
When the power switch is turned on, the lens barrel is extended, and after the collapsing switch is turned on in the non-photographing area, the number of pulse signals generated by the zoom position switch is counted, and the lens barrel has the widest angle. Stopped at the initial position at the focal length. On the other hand, when the lens barrel is in the shooting area,
When the power switch is turned off, after detecting the pulse signal generated by the zoom position switch, it is detected that the retract switch is turned off, and the lens barrel is operated to be retracted to the retract position.

[0008]

However, although the camera having a zoom lens as in the latter prior art has the above-mentioned advantages, it has the following various problems.

First, a second lens group holding frame for holding a second lens group with shutter blades interposed is mounted on a first lens group holding frame for holding the first lens group. An actuator or the like for operating a shutter blade also serving as an aperture is disposed behind the second lens group holding frame. For this reason, when replacing the actuator etc. during repair,
If both the first lens group holding frame and the second lens group holding frame were not removed, they could not be replaced, which was very troublesome.

Usually, the front lens holding frame for holding the front lens moves straight in the optical axis direction by a helicoid.
The rear group lens holding frame for holding the rear group lens moves straight in the optical axis direction by the groove cam. Then, zooming is performed while changing the lens interval. Accordingly, in order to cause only the straight movement without rotating the front lens holding frame and the rear lens holding frame, and to maintain the predetermined lens accuracy, the linear movement guide member for guiding the front lens holding frame straight is provided. It is necessary to engage the rear group lens holding frame with the front group lens holding frame. However, in this conventional camera, a helicoid is provided in the first lens group holding frame, the second lens group holding frame is mounted on the first lens group holding frame, and an actuator or the like for operating the diaphragm is provided in the second lens group holding frame. Therefore, the first lens group holding frame and the rear lens group frame could not have a sufficient length to engage with each other. As a result, the optical axis of the rear group lens is easily inclined with respect to the optical axis of the front group lens,
This was affecting lens performance.

Further, in the rear lens group holding frame moved in the optical axis direction by the groove cam, a small gap is inevitably formed between the groove cam and the cam pin. In general, a tension spring or a compression spring is applied between the front group lens holding frame and the rear group lens holding frame to absorb the cam pin so that the cam pin abuts on one side wall of the cam groove. In a camera, a spring cannot be applied because an actuator or the like is in the way, and there is no other way but to rely on the precision of the groove cam and the cam pin.

In view of such a problem, a camera with a zoom lens which includes a front lens group and a rear lens group in order from the subject side and has a zoom lens in which shutter blades are arranged in the front lens group is used for assembling or repairing. SUMMARY OF THE INVENTION It is a first object of the present invention to provide a camera with a zoom lens which facilitates the above operation and further ensures the lens performance.

Further, since the conventional lens cover unit is disposed in the order of the lens cover and the lens cover in order from the photographing lens side, the lens cover is disposed from the front lens of the photographing lens by the thickness of the lens cover ring. In view of the light rays that are arranged at a distance and obliquely incident on the front lens, the aperture must be large, resulting in an increase in the size of the lens cover itself and an increase in the size of the lens barrel. Also, the thickness as a lens cover unit,
The lens cover, the lens cover, and the lens cover base were required to have a certain thickness in a three-layer configuration.

In view of such a problem, it is a second object of the present invention to provide a camera having a lens cover unit having a small outer diameter, a thin lens barrel, and a small thickness.

As described above, in the related art, both the retractable switch and the zoom position switch are detected after the operation of the power switch, and the lens barrel is moved. However, the retractable switch is not used due to design reasons or manufacturing variations. And the position where the pulse signal is generated by the zoom position switch may overlap. For example, when assembled so that a pulse signal by the first zoom position switch is generated on the retracted position side from the switch position of the retracted switch, when the power switch is turned on at the retracted position, the signal of the first zoom position switch is output. There is a problem that the lens barrel should be stopped at the initial position at the wide-angle end in the shooting area, and stopped at the second wide-angle position in the shooting area. When the power switch is turned off in the shooting area, After the signal from the zoom position switch is generated, the retract switch is not switched, so that the operation is different from the predetermined sequence, resulting in an operation error.

In view of this problem, even if the switching position of the retractable switch and the position where the pulse signal is generated by the zoom position switch overlap due to design reasons or manufacturing variations, there is no problem in the forward and backward movement of the lens barrel. A third object of the present invention is to propose a camera with a zoom lens.

[0017]

A first object of the present invention is to provide a camera with a zoom lens which holds a zoom lens composed of a front group lens and a rear group lens in order from the subject side. In order, the first lens group,
The first lens group holding frame, which includes a shutter blade and a second lens group and holds the first lens group,
The problem is solved by a camera with a zoom lens that is supported by a second lens group holding frame that holds the lens group, and a helicoid for advance and retreat is screwed into the second lens group holding frame.

The second problem is that, in front of the taking lens,
In order from the photographing lens side, a lens cover that opens and closes by rotating, a lens cover base that pivotally supports the lens cover, a lens cover ring that opens and closes the lens cover by rotating, and performing the exterior The problem is solved by a camera with a zoom lens in which a makeup frame for holding a lens covering is arranged.

The third problem is that the lens barrel holding the zoom lens is electrically moved from the retracted position most retracted to the film side to the photographing area through which the photographing is performed through the non-photographing area where photographing is not performed. In a camera with a zoom lens, the focal length of which is divided in advance into a plurality of small regions, and the lens barrel stops at a predetermined initial position of the small region by a zooming operation, the initial position of the small region is determined in the photographing region. A zoom position switch that outputs a signal for determination at regular intervals, and also outputs the signal in a non-photographing area, a retractable switch that switches on or off at a predetermined position in the non-photographing area, When a power switch for starting position control of the lens barrel is provided, and the power switch is turned on at the retracted position, When only the zoom position switch is detected and the lens barrel is advanced to the initial position of the first small area in the photographing area, and when the power switch is turned off in the photographing area, only the retractable switch is detected. Then, the problem is solved by a camera with a zoom lens provided with control means for retracting the lens barrel to the retracted position.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First, a zoom lens barrel of a camera according to the present invention will be described with reference to FIGS. FIG. 1 is a vertical cross-sectional view of the zoom lens barrel. The upper half of the optical axis shows a state when a short focus is set, and the lower half of the optical axis shows a state when a long focus is set. It is painted.
FIG. 2 is an exploded perspective view showing the zoom lens barrel.

In both figures, reference numeral 1 denotes a fixed body, which carries all members described below and is fixed to a camera body (not shown). The fixed body 1 has a female helicoid 1 on the inner circumference.
a is screwed, and two guide grooves (not shown) for a rectilinear guide described later are provided substantially symmetrically with respect to the optical axis O and parallel to the optical axis O. Reference numeral 2 denotes a cam cylinder, on the outer periphery of which a male helicoid 2a screwed with the female helicoid 1a and a large gear 2b are integrally formed, and on the inner periphery, a female helicoid 2a.
c and a cam groove 2d are formed. Also, the large gear 2b
Is smaller than the root diameter of the male helicoid 2a, so that it does not come into contact with the peak of the female helicoid 1a of the fixed barrel 1. 3 is a female helicoid of the cam cylinder 2
It is a decorative frame for covering c and the like.

Reference numeral 4 denotes a second lens group holding frame, and the second lens group L _{F2 in} the front lens group of the zoom lens is provided on the inner periphery thereof.
, And the second lens group L _F2 is pressed by a lens holding plate 5 made of a thin plate, which is called a second lens group holding member in the claims from the rear. A male helicoid 4 a is screwed around the outer periphery, and the male helicoid 4 a is screwed with the female helicoid 2 c of the cam cylinder 2.

The front outer periphery 4 of the second lens group holding frame 4
“c” is exposed to the external appearance as it is and is one of the exterior members.

In front of the second lens group holding frame 4, a first lens group holding frame 6 for holding the first lens group L _F1 in the front lens group is disposed, and the first lens group holding frame 6 is a stop. It is fixed to the second lens group holding frame 4 with the shared shutter blade 7 interposed therebetween. Further, circuits and actuators for driving the shutter blades 7 are respectively provided at positions of the front portion 8 of the first lens group holding frame 6.

Reference numeral 11 denotes a rear lens group holding frame for holding the rear lens group L _R , and convex portions 11 a provided in three places on the outer periphery of the rear lens group holding frame 11 and parallel to the optical axis, and a second lens group. Recesses 4b parallel to the optical axis provided at three places on the inner rear side of the holding frame 4 are engaged. Therefore, the rear lens group holding frame 11 is held by the second lens group holding frame 4 while maintaining the same optical axis, and the rear lens group holding frame 11 slides with respect to the second lens group holding frame 4 in the optical axis direction. It can move, but cannot rotate about the optical axis. Also, three cam pins 12 are provided upright on the convex portion 11a of the rear lens holding frame 11, and are engaged with a cam groove 2d provided together with the female helicoid 2c on the inner periphery of the cam cylinder 2. .

A rectilinear guide plate 13 bent in an L-shape by a metal plate is rotatably attached to the rear portion 2e of the cam cylinder 2 about an optical axis O by a member (not shown).
The rectilinear guide plate 13 includes two rectilinear guide portions 13 parallel to the optical axis O.
a, the rectilinear guide portion 13a passes outside the outer circumference of the rear lens group holding frame 11 and engages with the long groove and the through hole provided on the inner circumference of the second lens group holding frame 4. On the other hand, the rectilinear guide plate 13 has two protrusions 13b orthogonal to the optical axis O, and engages with two long guide grooves, not shown, provided on the fixed body 1 and parallel to the optical axis O. doing.

Accordingly, when the cam barrel 2 advances and retreats while rotating, the straight guide plate 13 is prevented from rotating by the projection 13b, and performs only the straight movement together with the cam barrel 2. For this reason,
The rotation of the second lens group holding frame 4 is prevented by the rectilinear guide portion 13a, and only the rectilinear movement is performed. Also, since the rear lens holding frame 11 is slidably engaged with the second lens group holding frame 4 only in a direction parallel to the optical axis, the rear lens holding frame 11 also only moves straight.

As described above, the shutter driving member is the second
Since a sufficient space is provided in front of the lens group holding frame 4 and behind the second lens group holding frame, a relationship between the concave portion 4b of the second lens group holding frame 4 and the convex portion 11a of the rear group holding frame 11 is provided. The combined length can be sufficiently set, and the optical axis of the first lens unit L _{F1, that} is, the optical axis of the front lens unit and the rear lens unit L surely match.

In addition, a play in a direction parallel to the optical axis is generated between the cam pin 12 erected on the rear lens holding frame 11 and the cam groove 2d of the cam barrel 2 due to processing accuracy. In order to absorb this play, the projection 5a provided on the outer periphery three locations of the lens holding plate 5 for holding the second lens group L _F2, similarly between the projection 11b provided in the rear group lens holding frame 11 The tension spring 14 is attached. As a result, the cam pin 13 is in the cam groove 2d.
Inside the cam groove 2d, and is in contact with only the front side surface of the cam groove 2d, so that the play of the cam groove 2d becomes irrelevant.

As described above, the shutter driving member is the second
Since it is located in front of the lens group holding frame 4, the tension spring 14 can be attached in this manner.

The rear lens holding frame 11 is opposite to the above.
It is also possible to provide a cam groove and a cam pin on the cam cylinder 2.

Next, the lens cover will be described with reference to FIG. 3 in addition to FIGS.

[0033] In FIGS. 1 and 2, the members constituting the lens cover is in front of the first lens group L _F1, in order from the first lens group L _F1 side, a lens cover 2 consisting of two members
1. A lens cover base 23 that holds a support shaft 22 that rotatably supports the lens cover 21 through a shaft hole 21a, and a lens cover ring that is rotated by a member described below to open the closed lens cover 21. 24. A decorative frame 2 which is an exterior member obtained by covering these members and drawing a thin plate.
5 are arranged.

Further, by inserting the lens cover ring 24 into a groove provided circumferentially in the lens cover base 23, positioning around the optical axis O is performed, and with respect to the thickness direction of the lens cover ring 24, The positioning is performed by the bottom surface of the groove of the lens cover base 23 and the decorative frame 25.

In FIG. 2, an operating pin 24a is provided at the rear of the lens cover ring 24, and passes through the elongated hole 23a of the lens cover base 23.
1b. A spring (not shown) is applied to the lens cover ring 21 to urge the lens cover ring 24 clockwise. Therefore, when the lens cover 24 is not driven by a member to be described later, the lens cover 21 rotates clockwise about the shaft hole 21a to be in a closed state.

Next, an opening and closing mechanism of the lens cover will be described with reference to FIGS. FIG. 3 is a plan view of the lens cover driving mechanism. FIG. 3A is a view in which the lens cover is closed, and FIG. 3B is a view in which the lens cover is open.

In both figures, reference numeral 31 denotes a lens cover operating member, which is not shown in the figure.
And is slidable in the left-right direction, and is urged in the negative direction by a tension spring 32.

Reference numeral 33 denotes a third lens cover driving member.
Similarly, it is mounted on the camera body or the fixed body 1 and is slidable in the left-right direction, urged in one direction by a tension spring 34, and bent into an L-shape first end 33.
At a, the lens cover operating member 31 is engaged. Reference numeral 35 denotes a second lens cover driving member which engages with a long groove (not shown) parallel to the optical axis provided on the inner periphery of the second lens group holding frame 4 and is slidable in the optical axis direction. When the cover is closed, the rear end 35a is in contact with the L-shaped second end 33b of the third lens cover driving member 33 as shown in FIG. Reference numeral 36 denotes a first lens cover driving member, which is formed in a crank shape and is urged counterclockwise by a torsion coil spring 38 around a support shaft 37 provided on the first lens group holding frame 6, and is provided at one end. The provided forked portion 36a is engaged with an engaging pin 35b provided upright on the second lens cover driving member 35, and the side surface of the other end portion 36b is an engaging portion 24b bent rearward of the lens cover ring 24.
And can be engaged with the side surface of the vehicle.

Only when the first lens group holding frame 6 is fixed to the second lens group holding frame 4, the forked portion 36a of the first lens cover driving member 36 and the second lens cover driving member 3
5 is engaged with the engagement pin 35b.

In the above configuration, when the zoom lens barrel is retracted, the state is as shown in FIG. 3A, and the other end 36 of the first lens cover driving member 36 is provided.
The side surface of b is farther from the side surface of the engaging portion 24b of the lens cover 24. Therefore, as described above, the lens cover ring 24 is rotated clockwise to close the lens cover 21.

In this state, when the lens cover operating member 31 is slid leftward as shown in FIG. 3B against the tension spring 32, the third lens cover driving member 33 is also moved by the first end 33a. It slides leftward against the tension spring 34. Then, the second lens cover driving member 33
End 33b and rear end 3 of second lens cover drive member 35
The contact with 5a is released. As a result, the second lens cover driving member 35 slides rearward by the urging force of the torsion coil spring 38. Then, the second end 33 b of the third lens cover driving member 33 comes into contact with the notch 35 c of the second lens cover driving member 35.

In this state, the right side of the second end 33b of the third lens cover driving member 33 comes into contact with the left side of the rear end 35a of the second lens cover driving member 35.
The third lens cover driving member 33 cannot return to the right due to the urging force of the tension spring 34. However, only the lens cover operating member 31 can be independently returned to the original position by the tension spring 32.

In this state, the first lens cover driving member 36 rotates counterclockwise, but the biasing force of the torsion coil spring 38 causes the lens cover ring 24 to rotate clockwise. This is because it is stronger than the urging force. As a result, the side surface of the other end portion 36b of the first lens cover driving member 36 is engaged with the engagement portion 24b of the lens cover ring 24.
Is pressed to rotate the lens cover ring 24 counterclockwise in FIG. Therefore, the lens cover 21 rotates counterclockwise about the shaft hole 21a by the counterclockwise rotation of the operating pin 24a of the lens cover ring 24, and the lens cover 21 is opened.

As described above, the lens cover operating member 3
When the switch 1 is operated, a switch (not shown) is turned on, and the zoom lens barrel is extended to a wide-angle position. When the zoom switch (not shown) is further operated, the zoom lens is extended to a more telephoto state. At this time, although the second lens cover driving member 35 is located at a position farther from the third lens cover driving member 33, even if the second lens cover driving member 35 is urged rearward by the torsion coil spring 38, it is provided on the second lens group holding frame 4. The stopper does not move backward beyond the specified position due to the stopper not being used.
Further, the lens cover 21 maintains the open state. As a result, the right side surface of the second end 33b of the first lens cover driving member 33 and the rear end 35 of the second lens cover driving member 35
Since the contact of the third lens cover driving member 33 with the left side surface is released, the third lens cover driving member 33 returns rightward by the urging force of the tension spring 34.

The operation of the zoom lens barrel having the above configuration will be described below.

When the lens cover operating member 31 is operated as described above, a switch (not shown) is turned on, and the lens barrel drive motor 41 shown in FIG. 4 is driven to rotate. FIG. 4 is a perspective view of a lens barrel drive motor for driving the small gear 15 shown in FIG. 2, a reduction gear, and the like as viewed from the other side of FIG. When the lens barrel drive motor 41 rotates, the rotation of the pinion 43 attached to the motor shaft 42 reduces the speed of the reduction gears 44, 45, 4.
Transmitted through the gears 6 and 48 to the gear 49 which is long in the optical axis direction,
The small gear 15 rotatably mounted on the rectilinear guide plate 13 is rotated.

A propeller 51 having a plurality of blades is attached to the motor shaft 42, and a photo interrupter 52
Outputs a pulse signal. A propeller 53 having one blade is attached to a gear shaft 47 of the reduction gear 46, and a pulse signal is output by a photo interrupter 54. The operation of these pulse signals will be described later.

Since the small gear 15 meshes with the large gear 2b of the cam cylinder 2, the cam cylinder 2 is extended from the fixed barrel 1 while rotating in accordance with the lead of the male helicoid 2a. When the cam cylinder 2 rotates, the rotation is transmitted to the male helicoid 4a of the second lens group holding frame 4 by the female helicoid 2c, but the rotation of the second lens group holding frame 4 is prevented by the rectilinear guide plate 13. Therefore, it is fed straight out according to the lead of the male helicoid 4a.

The second lens unit L _F2 includes a second lens unit holding frame 4
The first lens group L _F1 is held by the first lens group holding frame 6, and the first lens group holding frame 6 is held by the second lens group holding frame 4 with the shutter blade 7 interposed therebetween.
Because it is secured to, the first lens group L _F1 is the front lens group and the second lens unit L _F2 while keeping constant the distance between the lenses, it will be that fed in accordance with the lead of the two helicoid.

On the other hand, the rotation of the cam groove 2 d of the cam cylinder 2 moves the cam pin 12 in the optical axis direction, and the rear lens group holding frame 11 is prevented from rotating by the second lens group holding frame 4. The group lens holding frame 11 is fed straight forward according to the shape of the cam in the cam groove 2d. Therefore, the rear lens group _LR is straightly extended according to the lead of the male helicoid 2a of the cam cylinder 2 and the shape of the cam.

Next, zooming and focusing in the present zoom lens barrel will be described. This zoom lens barrel is a so-called step zoom system in which the space between the wide-angle end and the telephoto end is divided into a predetermined number of steps, that is, steps, and the zooming and focusing can be performed by the same mechanism. Thus, a zoom lens barrel having a simple configuration can be realized.

Explaining with reference to the step zoom diagram of FIG. 5, the horizontal axis indicates a change in the focal length, and is divided into six steps from the wide-angle end W to the telephoto end T. The vertical axis indicates the amount of movement of the front lens group and the rear lens group of the zoom lens in the optical axis direction. As described above, the front group lens moves linearly because it moves only by the helicoid, but the rear group lens moves by the cam, so that an arbitrary movement diagram can be provided. For example, when focusing is performed from the state of infinity あ る, which is the initial position at the wide angle end W, the lens is moved to the state at the close distance N. Explanation This state corresponds to the closest distance N of the initial position at the focal length M ₁ of the wide angle to the second, when performing focusing in focal length M ₁ of the wide-angle to the second, from the state of the closest distance N infinity ∞ The lens is moved to the state of. The second state at infinity 広 at the wide-angle focal length M ₁ corresponds to the third position at infinity 初期 at the initial position at the wide-angle focal length M ₂ . As described above, in the step zoom method, since focusing is performed while performing zooming, that is, while changing the focal length, zooming and focusing can be performed by the same mechanism.

The configuration of this step zoom will be described in more detail with reference to FIGS. 4, 6 and 7. FIG. 6 is a timing chart of the lens barrel movement from the retracted position to the shooting area,
FIG. 7 is a block diagram of control means for controlling the advance / retreat of the lens barrel.

In FIG. 6, the retracted position on the horizontal axis is the position where the lens barrel is most retracted to the film side, and the non-photographing area is the area where the lens barrel is extended from the retracted position but cannot be photographed. The photographing region is a region in which the focal length can be changed in six steps (small region in claims) between the wide-angle end W, which is the widest angle, and the telephoto end T, which is the most telephoto, as described above. The zoom position switch on the vertical axis corresponds to the propeller 53 and the photo interrupter 5 shown in FIG.
4, a pulse signal (referred to as LDP2) for determining the initial position of each step in the photographing area is output at regular intervals, but as shown in FIG.
Rotates, the pulse signal LDP is output even in the non-photographing area.
2 occurs. Although not shown, the retractable switch is a switch that is switched from on to off in a non-photographing area with movement of the lens barrel.

When the power switch for starting the position control of the lens barrel is turned on when the lens barrel is in the retracted position, after the control circuit shown in FIG. At this time, the number of pulse signals LDP2 of the zoom switch is counted irrespective of ON / OFF of the retracting switch, and the third pulse signal LDP2 is output in FIG. Then, the lens barrel stops. This position is the initial position of the wide-angle end W which is the first step in the photographing area. If the zoom switch is operated in this state, the focal length becomes M _{1 to} T
Then, an arbitrary focal length can be selected. When focusing is performed, distance information from the distance measuring circuit and FIG.
The lens barrel is stopped at a predetermined position by comparing the number of continuous pulse signals (referred to as LDP1) having a fine pitch outputted by the propeller 51 and the photo interrupter 52 shown in FIG.

When the power switch is turned off while the lens barrel is in the photographing area, the lens barrel is retracted after detecting the OFF state of the retractable switch regardless of the pulse signal LDP2 of the zoom position switch. When the number of predetermined pulse signals LDP1 is counted after the switch is turned on, it is determined that the lens barrel has retracted to the retracted position, and the lens barrel drive motor 41 is stopped.

As described above, the control circuit shown in FIG. 7 includes the power switch, the zoom switch, the distance information from the distance measuring circuit,
The lens barrel drive motor M is controlled by the pulse signals LDP1 and LDP2 and the retracting switch switching signal.

[0058]

According to the camera with the zoom lens of the first aspect, the shutter blades and the first lens group are held while the second lens group holding frame holding the second lens group is mounted on the zoom lens barrel. Since the first lens group holding frame can be attached and detached, work efficiency at the time of assembly and repair is improved.

According to the camera with the zoom lens of the second aspect, since the shutter driving member is held by the first lens group holding frame, it can be easily attached and detached, and the working efficiency at the time of assembly and repair is improved.

According to the camera with the zoom lens of the third aspect, since a part of the second lens group holding frame is exposed to the outside, a special exterior component is not required, and the size of the lens barrel can be reduced.

According to the camera with the zoom lens of the fourth aspect, the shutter driving member is located in front of the second lens group holding frame 4 and a sufficient space is provided behind the second lens group holding frame. Can take a sufficient length, and the optical axes of the front group lens and the rear group lens are surely matched, and the lens performance is improved.

According to the camera with the zoom lens of the fifth and sixth aspects, the rear group lens holding frame is urged by the urging member engaged with the second lens group holding member. The cam groove can be easily processed, and the lens performance can be improved.

According to the camera with the zoom lens according to the seventh and eighth aspects, the lens cover can be opened and closed by a simple driving member.

According to the camera with the zoom lens of the ninth aspect, since the lens cover is disposed immediately before the front lens,
Considering the light beam obliquely incident on the front lens, it is sufficient to open the lens with the minimum size.As a result, the size of the lens cover itself is reduced, and the outer diameter of the lens barrel is formed to the minimum thickness. Can be.

According to the camera with the zoom lens of the tenth aspect, since the lens cover ring is arranged in the circular groove provided in the lens cover base, a thin lens cover unit can be realized.

According to the camera with the zoom lens of the present invention, different switches are detected when the lens barrel is advanced from the retracted position to the photographing area and when the lens barrel is retracted from the photographing area to the retracted position. Therefore, there is no problem even if the positions of the switches vary, and the degree of freedom in designing the positions of the switches is increased, and the productivity is improved.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a zoom lens barrel.

FIG. 2 is an exploded perspective view showing a zoom lens barrel.

FIG. 3 is a plan view of a lens cover driving mechanism.

FIG. 4 is a perspective view of a lens barrel drive motor and the like.

FIG. 5 is a step zoom diagram.

FIG. 6 is a timing chart of lens barrel movement.

FIG. 7 is a block diagram of control means for controlling the advance / retreat of the lens barrel.

[Explanation of symbols]

L _F1 first lens group L _F2 second lens group L _R rear group lens 1 fixed body 2 cam barrel 4 second lens group holding frame 5 lens holding plate 6 first lens group holding frame 7 shutter blade 11 rear group lens holding frame DESCRIPTION OF SYMBOLS 13 Straight guide plate 14 Extension spring 21 Lens cover 23 Lens cover base 24 Lens covering 25 Decorative frame 33 Third lens cover driving member 35 Second lens cover driving member 36 First lens cover driving member 51, 53 Propeller 52, 54 Photo Interrupter

Claims (11)

[Claims] 1. A camera with a zoom lens holding a zoom lens composed of a front lens group and a rear lens group in order from the subject side, wherein the front lens group includes a first lens group, a shutter blade, and a A first lens group holding frame that holds the first lens group, is supported by a second lens group holding frame that holds the second lens group, and the second lens group holding frame A camera with a zoom lens, characterized by a helicoid for screwing in and out. 2. The camera with a zoom lens according to claim 1, wherein the first lens group holding frame holds a shutter blade driving member that opens and closes a shutter blade. 3. The camera with a zoom lens according to claim 1, wherein a part of the second lens group holding frame is exposed to the outside. 4. The second lens group holding frame according to claim 1, wherein a guide portion for guiding the rear lens group holding frame for holding the rear lens group in the optical axis direction is provided on the second lens group holding frame. A camera with a zoom lens according to claim 1. 5. The camera with a zoom lens according to claim 1, wherein the rear lens holding frame has a cam pin or a cam groove and is driven by a cam. 6. A second lens group holding member for holding the second lens group from the film surface side after inserting the second lens group into the second lens group holding frame, and holding the second lens group. The camera with a zoom lens according to any one of claims 1 to 5, wherein the rear group lens holding frame is urged in an optical axis direction by an urging member fixed to one end of the member. 7. A first driving member that has a lens cover disposed on the subject side of the first lens group holding frame and rotates about a part of the first lens group holding frame as a fulcrum, and that holds the second lens group. The zoom lens according to any one of claims 1 to 6, wherein the lens cover is opened and closed by a second driving member slidable in an optical axis direction by a guide portion provided on a frame. camera. 8. The first drive member and the second drive member are engaged by mounting the first lens group holding frame on the second lens group holding frame. A camera with a zoom lens as described in 1. 9. A lens cover that opens and closes by rotating in front of the photographing lens from the photographing lens side, a lens cover base that pivotally supports the lens cover, and opens and closes the lens cover by rotating. A camera with a zoom lens, wherein a lens covering to be provided and a decorative frame for holding the lens covering are provided. 10. The camera with a zoom lens according to claim 9, wherein the lens cover ring is arranged in a circular groove provided in the lens cover base. 11. A lens barrel holding an electrically driven zoom lens is extended from a retracted position where it is most retracted to the film side to a photographing area where photographing is performed through a non-photographing area where photographing is not performed. In a camera with a zoom lens that is divided into a plurality of small areas and the lens barrel stops at a predetermined initial position of the small area by a zooming operation, a signal for determining an initial position of the small area in the shooting area And a zoom position switch that outputs the signal even in a non-photographing area, a retractable switch that switches on or off at a predetermined position in the non-photographing area, and a position control of the lens barrel. When the power switch is turned on at the retracted position, the zoom When only the position switch is detected, the lens barrel is advanced to the initial position of the first small area in the imaging area, and when the power switch is turned off in the imaging area, only the retractable switch is detected. A camera with a zoom lens, further comprising control means for retracting the lens barrel to the retracted position.