JP2001235670A - Lens device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lens device which is easily assembled and whose forming driving accuracy is improved by forming it so that one end of a straight advance hole is made to communicate with a cam hole. SOLUTION: A second lens straight advance hole 23 and a moving barrel can hole 24 are formed on the peripheral surface of a fixed barrel 16, and one end of a second lens straight advance hole 23 is formed so as to communicate with the moving barrel can hole 24. Thus, a second lens cam pin 29 engaged with the second lens straight advance hole 23 is easily fitted in the second lens straight advance hole 23 by using the moving barrel can hole 24. Thus, the assembly of the lens device is facilitated. Also, the second lens straight advance hole 23 holds the second lens cam pin 29 engaged by forming the width of the second lens straight advance hole 23 so as to be smaller than the size of the second lens cam pin 29, so that backlash is eliminated and driving accuracy at the time of driving a lens is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lens device,
In particular, the present invention relates to a lens device used in a retractable camera having a zoom function.

[0002]

2. Description of the Related Art A cam mechanism is known as a means for moving a lens barrel along an optical axis. The cam mechanism includes, for example, three cam pins provided on an outer peripheral surface of a lens barrel, the cam pins being engaged with three rectilinear holes formed in the fixed barrel, and three cam grooves formed in the rotary barrel. It is constituted by engaging. Alternatively, 3 on the outer peripheral surface of the lens barrel
A cam pin is provided, and the cam pin is engaged with three cam holes formed in the fixed cylinder, and is engaged with three rectilinear grooves formed in the rotating cylinder.
In the cam mechanism configured as described above, the rotation of the rotary barrel causes the lens barrel to move by a displacement along the optical axis of the cam groove or the cam hole.

[0003] By the way, some cam mechanisms are constructed so that one lens barrel can move a plurality of lens barrels. In this case, the peripheral surface of the fixed barrel has
Cam holes or rectilinear holes are formed by the number of lens barrels to be moved. Conventionally, when a cam hole and a rectilinear hole are formed in one fixed cylinder, they are provided independently so as not to cross each other. For this reason, when assembling the lens device, first, the lens barrel is arranged in a fixed barrel, and then a cam pin is inserted into a rectilinear hole to fix the lens barrel to the outer peripheral surface of the lens barrel.

[0004]

However, in the case of the conventional method of inserting a cam pin into a rectilinear hole and attaching the cam pin to the lens barrel, an asobi is required between the rectilinear hole and the cam pin, and after the asobi is assembled, There is a disadvantage that backlash occurs when the lens is driven, which lowers the driving accuracy.

[0005] In addition, since the method is a method of inserting and inserting a cam pin into the straight hole, assembly is troublesome and there is a disadvantage that productivity is poor.

The present invention has been made in view of such circumstances, and has as its object to provide a lens device which can be easily assembled and can improve driving accuracy.

[0007]

In order to achieve the above object, the present invention provides a lens apparatus having a cam hole having an open end and a rectilinear hole formed on the peripheral surface of a cylindrical body. By forming one end of the rectilinear hole into the cam hole and forming the width of the rectilinear hole smaller than the diameter of a cam pin engaged with the rectilinear hole, the both ends of the rectilinear hole are formed. A lens device is provided, wherein the cam pin is sandwiched between edges.

In order to achieve the above object, according to the present invention, a guide groove is formed on a peripheral surface of the cylindrical body along a peripheral edge of the cam hole, and a guide portion engaging with the guide groove is provided on the cam. 2. The lens device according to claim 1, wherein a width of the guide portion is formed to be larger than a width of the rectilinear hole at a communicating position between the rectilinear hole and the cam hole. I do.

According to the present invention, by forming one end of the rectilinear hole in communication with the cam hole, the cam pin to be engaged with the rectilinear hole can be fitted into the rectilinear hole using the cam hole. This facilitates the assembly of the lens device.

Also, by forming the width of the rectilinear hole smaller than the diameter of the cam pin, the rectilinear hole can sandwich the engaged cam pin, thereby eliminating backlash and improving the driving accuracy when driving the lens. Is improved.

Further, by forming the guide portion on the cam pin engaging with the cam hole, the cam pin engaging with the cam hole is prevented from entering the rectilinear hole.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a lens device according to the present invention will be described below in detail with reference to the accompanying drawings.

FIG. 1 is a perspective view showing an external configuration of an electronic still camera to which a lens device according to the present invention is applied.

As shown in FIG. 1, a camera body 1 of this electronic still camera is formed in a rectangular box shape, and a lens device 2, a finder window 3, a strobe light control sensor 4, a self A timer lamp 5, a strobe light emission window 6, and the like are provided. A finder eyepiece 7, a liquid crystal display panel (not shown), operation keys, and the like are provided on a back surface thereof, and a release switch 8, a power switch 9, and the like are provided on an upper surface thereof. This electronic still camera is of a so-called collapsible type, and the lens barrel is extended from the camera body 1 only when the lens device 2 is used.

FIG. 2 is an exploded perspective view of a lens device 2 applied to the electronic still camera 1 described above. Also, FIG.
FIG. 5 is a side sectional view of a lens device 2 applied to the electronic still camera 1 described above. FIG. 3 shows a state in which the lens device 2 is in the retracted position, and FIG.
5 and FIG. 5 show a state where the lens device 2 is in the tele position and a state where the lens device 2 is in the wide position, respectively.

As shown in FIGS. 2 to 5, the lens apparatus 2 includes a first lens 11, a second lens 12, a first lens barrel 13, a second lens barrel 14, a moving barrel 15, and a fixed barrel 16 (cylinder). Body) and a rotary cylinder 17.

The rotary cylinder 17 has a gear portion 18 formed on its outer peripheral surface. The gear section 18 includes a zoom motor 19
Is transmitted. When the drive of the zoom motor 19 is transmitted to the gear portion 18, the rotating cylinder 17 is rotated while being in contact with the outer periphery of the fixed cylinder 16.

Here, the lens device 2 includes
Is "storage rotation range" from "initial position" to "intermediate position"
3, the state is changed from the retracted position shown in FIG. 3 to the telescopic position shown in FIG. 4, and the rotating cylinder 17 is moved from the "intermediate position" to the "end position". By rotating in the "rotational range", the state is changed from the tele position shown in FIG. 4 to the wide position shown in FIG.

The inner peripheral surface of the rotary cylinder 17 has a second
Second movement for moving the lens barrel 14 along the optical axis 20
A lens cam groove 21 and a moving cylinder rectilinear groove 22 for guiding the moving cylinder 15 along the optical axis 20 are formed. The second lens cam groove 21 and the moving cylinder rectilinear groove 22
Are formed at three divided positions around the optical axis.

The fixed barrel 16 has a second lens barrel 14 on its peripheral surface for guiding the second lens barrel 14 linearly along the optical axis 20.
The lens straight advance hole 23 (straight advance hole) and the movable cylinder 15 are
A cam hole 24 (cam hole) for a moving cylinder for moving along 0 is formed. This second lens straight advance hole 23
The moving cylinder cam hole 24 is formed at three divided positions around the optical axis.

The movable barrel 15 is provided with a movable barrel cam pin 25 on its outer peripheral surface. This moving cylinder cam pin 2
Numeral 5 is provided at three divided positions around the optical axis, and is engaged with a movable cylinder cam hole 24 formed in the fixed cylinder 16 and a movable cylinder straight groove 22 formed in the rotary cylinder 17, respectively. ing.

The inner peripheral surface of the movable cylinder 15 has a first
A first for moving the lens barrel 13 along the optical axis 20
A lens cam groove 26 is formed. The first lens cam groove 26 is formed at three divided positions around the optical axis.

The first lens barrel 13 holds the first lens 11 at its front end. A pair of rectilinear guide grooves 27 are formed on the inner peripheral surface of the first lens barrel 13 along the optical axis 20 at predetermined intervals.

A first lens cam pin 28 is provided on the outer peripheral surface of the first lens barrel 13. The first lens cam pins 28 are provided at three divided positions around the optical axis, and are formed on the inner peripheral surface of the movable barrel 15.
It is engaged with the lens cam groove 26.

The second lens barrel 14 is provided with a second lens cam pin 29 on its outer peripheral surface. The second lens cam pins 29 are provided at three divided positions around the optical axis. The second lens cam grooves 21 formed in the rotary barrel 17 and the second lens cam grooves 21 formed in the fixed barrel 16 are provided. It is engaged with the rectilinear hole 23.

A spring is mounted between the rear end of the second lens barrel 14 and the rear end of the fixed barrel 16. The spring 37 is provided at three divided positions around the optical axis, and urges the second lens barrel 14 toward the image plane.

A pair of arms 38 are integrally formed at a front end of the second lens barrel 14 at a predetermined interval. The arm 38 has a narrow width extending from the front end of the second lens barrel 14 toward the subject, and a straight guide projection 30 is integrally formed on the outer periphery of the front end. The rectilinear guide protrusion 30 is engaged with a rectilinear guide groove 27 formed on the inner peripheral surface of the first lens barrel 13.
The two wall surfaces 30a, 30b are in contact with both wall surfaces 27a, 27b of the straight guide groove 27. First lens barrel 13
Is guided linearly in the optical axis direction with respect to the second lens barrel 14 in a state where its rotation is stopped by the linear guide projection 30 and the linear guide groove 27.

The second lens barrel 14 is made of an elastically deformable material such as plastic, and each arm 38 is formed with its front end extending radially outward. I have. For this reason, the straight guide projection 30
Is engaged with the linear guide groove 27, the linear guide protrusion 30
Is pressed against the bottom 27c of the linear guide groove 27. As a result, the first lens barrel 13 is
The lens barrels 14 are supported so as not to be inclined with respect to each other.

The straight guide projection 30 has a hemispherical tip surface 30c in order to reduce the resistance during sliding. That is, the cross section in the optical axis direction and the cross section in the direction perpendicular to the optical axis are each formed in an arc shape. Thereby, the first lens barrel 13 and the second lens barrel 1
4, and the rotational load of the rotary cylinder 17 is reduced.

The second lens 12 is held by a second lens frame 33 movably provided along the optical axis 20 in the second lens barrel 14 as shown in FIGS. The second lens frame 33 is movably provided in the second lens barrel 14 along the optical axis 20 by the feed screw 31 and the guide rod 32. A focus motor 34 is connected to the feed screw 31. By driving the focus motor 34, the second lens 12 moves in the optical axis direction according to the lead of the feed screw 31.

The movement of the second lens 12 is caused by the second movement.
The process is performed between the “origin position” closest to the image plane 10 a with respect to the lens barrel 14 and a position farther from the origin position toward the subject. At the time of zooming, the second lens 12 is located at the “origin position”.

FIG. 7 is a developed view showing the structure of the first lens cam groove 26 provided on the inner peripheral surface of the movable barrel 15.

The first lens cam groove 28 is engaged with a first lens cam pin 28 provided in the first lens barrel 13. The first lens cam groove 26 includes a first lens storage preparation guide section 42, a first lens movement prevention section 43, and a first lens variable power guide section 44.

The first lens housing preparation guide section 42 is a range in which the first lens cam pin 28 slides when the rotary cylinder 17 rotates in the rotation range from the “initial position” to the “rotation position A”. . The first lens storage preparation guide section 42 includes a “retreat position” in which the first lens barrel 13 is retracted toward the image plane with respect to the movable barrel 15 and a “storage preparation position” slightly projecting toward the subject. To move between. When the lens device 2 is in the retracted position, the first lens barrel 13 is located at the "retreat position".

The first lens movement preventing section 43 is provided with the rotating cylinder 17.
Is the range in which the first lens cam pin 28 slides when rotated in the rotation range from the “rotational position A” to the “intermediate position”. The first lens movement prevention unit 43
The first lens barrel 13 is formed along the direction around the optical axis of the movable barrel 15 so that the first lens barrel 13 does not move in the optical axis direction from the “storage preparation position” while allowing the rotation of the movable barrel 15. As a result, the first lens barrel 13 is maintained at the "storage preparation position" until the lens device 2 changes from the retracted position to the telephoto position.

The first lens variable power guide section 44 is
Is the "magnification rotation range" from the "middle position" to the "end position"
This is the range in which the first lens cam pin 28 slides when rotated. The first lens variable power guide section 44 is shaped to move the first lens barrel 13 along the optical axis 20 in order to change the focal length.

It is to be noted that the first lens storage preparation guide section 42 is not always necessary, and the first lens storage preparation guide section 42 is omitted, and the entire rotation range of the movable barrel 15 corresponding to the "storage rotation range" of the rotary barrel 17 is prevented from moving by the first lens. The unit 43 may be used.

FIG. 8 shows a cam hole 24 (cam hole) for the moving cylinder and a rectilinear hole 23 for the second lens formed on the peripheral surface of the fixed cylinder 16.
It is a development view showing the configuration with (straight hole).

First, the configuration of the moving cylinder cam hole 24 will be described. A cam pin 25 for the moving cylinder provided on the outer peripheral surface of the moving cylinder 15 is engaged with the cam hole 24 for the moving cylinder. The movable cylinder cam hole 24 includes a movable cylinder storage guide section 40 and a movable cylinder movement prevention section 41.

The movable cylinder storage guide section 40 is a range in which the movable cylinder cam pin 25 slides when the rotary cylinder 17 rotates in the “storage rotation range” from the “initial position” to the “intermediate position”. The movable cylinder storage guide section 40 has an optical axis between a “retreat position” in which the movable cylinder 15 is retracted toward the image forming surface 10a with respect to the fixed cylinder 16 and a “projection position” extended to the subject side. Move along 20. When the lens device 2 is in the retracted position, the movable barrel 15 is located at the "retreat position".

The movable cylinder movement preventing portion 41 is a range in which the movable cylinder cam pin 25 slides when the rotating cylinder 17 rotates in the “magnification rotation range” from the “intermediate position” to the “end position”. . The movable cylinder movement preventing portion 41 is formed along the direction around the optical axis 20 so as to prevent the movable cylinder 15 from moving in the optical axis direction while allowing the movable cylinder 15 to rotate around the optical axis. ing. Thus, the moving barrel 15 is maintained at the “projected position” while the lens apparatus 2 is zoomed between the tele position and the wide position.

Next, the structure of the second lens straight advance hole 23 will be described. A second lens cam pin 2 provided on the outer peripheral surface of the second lens barrel 14 is provided in the second lens straight advance hole 23.
The nine rectilinear hole engaging portions 54 are engaged. The second lens rectilinear hole 23 is formed along the optical axis 20, and the front end thereof is communicated with the moving cylinder movement preventing portion 41 of the moving cylinder cam hole 24.

The fixed cylinder 16 in which the second lens straight-moving hole 23 is formed is made of an elastically deformable material such as plastic. When the second lens rectilinear hole 23 and the movable cylinder cam hole 24 are formed so as to communicate with each other with respect to the fixed cylinder 16 formed of the elastically deformable material as described above, the second lens rectilinear The hole 23 is formed so as to be able to expand and contract in the width direction.

The width A of the second lens rectilinear hole 23 formed so as to be freely expandable and contractible in the width direction is changed to the width B of the rectilinear hole engaging portion 54 of the second lens cam pin 29.
If it is formed slightly smaller than (see FIG. 11), the second lens rectilinear hole 23 is engaged with the engaged second lens cam pin 2.
Nine straight-running hole engaging portions 54 are sandwiched from both sides by the edge portions. Thereby, the engaged second lens cam pin 2
As shown in FIG. 9, there is no play between the rectilinear hole engaging portion 54 and the second lens rectilinear hole 23, and the second lens barrel 14 can be guided linearly with high accuracy.

On the other hand, as described above, the second lens rectilinear
Is formed so as to communicate with the moving cylinder cam hole 24, the cam hole engaging portion 25 </ b> A of the moving cylinder cam pin 25 engaged with the moving cylinder cam hole 24 slides through the moving cylinder movement preventing portion 41. Second
There is a risk of entering the lens rectilinear hole 23 or getting caught in the communicating portion.

Therefore, the cam pin 25 for the movable cylinder is formed as follows to prevent the moving pin cam pin 25 from getting into or catching in the second lens rectilinear hole 23.

FIGS. 9 and 10 are a plan view and a side view, respectively, showing the configuration of the cam pin 25 for the movable barrel. As shown in the figure, the cam pin 25 for the movable cylinder is
A, a guide groove engaging portion 25B and a rectilinear groove engaging portion 25C.

The cam hole engaging portion 25A is formed in a columnar shape, and engages with the moving tube cam hole 24 provided in the fixed tube 16.

The guide groove engaging portion 25B is
It is integrally formed on the top of 5A, and is formed in a trapezoidal plate shape. The guide groove engaging portion 25B is engaged with a guide groove 49 formed on the outer peripheral surface of the fixed cylinder 16. The guide groove 49 is formed along the edge of the movable cylinder cam hole 24. The guide groove engagement portion 25B is engaged with the guide groove 49, so that the movable cylinder cam pin 25 is connected to the second lens. It is prevented from entering or being caught in the rectilinear operation hole 23. That is, since the width C of the guide groove engaging portion 25B in the direction around the optical axis is formed to be larger than the width A of the second lens rectilinear hole 23, the guide groove engaging portion 25B is obstructed. Accordingly, the moving cylinder cam pin 25 is prevented from entering or being caught in the second lens rectilinear hole 23.

The guide groove engaging portion 25B is formed such that its width D in the optical axis direction is larger than the width E of the cam hole 24 for the movable cylinder. Thereby, the cam pin 25 for the moving cylinder
From the cam hole 24 for the movable cylinder is prevented.

The rectilinear groove engaging portion 25C is
5B is integrally formed on the upper surface, and is formed in an elongated circular plate shape. The rectilinear groove engaging portion 25C is
7 and engages with the moving cylinder straight groove 22. In addition,
The operation of the rectilinear groove engaging portion 25C formed in an elongated circular shape will be described later.

FIG. 11 is a front view showing the structure of the second lens cam pin 29 provided in the second lens barrel 14.
As shown in the drawing, the second lens cam pin 29 includes a rectilinear hole engaging portion 54 and a cam groove engaging portion 55.

The rectilinear hole engaging portion 54 is formed in a cylindrical shape, and the second lens rectilinear hole 23 formed in the fixed cylinder 16 is formed.
Engages.

On the other hand, the cam groove engaging portion 55 is
5a and a variable-power engagement portion 55b, which are engaged with the second lens cam groove 21 formed on the inner peripheral surface of the rotary cylinder 17.

The housing engaging portion 55a is integrally formed coaxially with the top of the rectilinear hole engaging portion 54, and has a truncated conical cross section. The housing engagement portion 55a engages with the second lens housing guide portion 58 of the second lens cam groove 21. Note that the bottom surface of the storage engagement portion 55a is formed to have a diameter larger than the outer diameter of the second lens rectilinear hole 23, and the rectilinear hole engagement portion 54 engages with the second lens rectilinear hole 23. , Comes into contact with the outer peripheral surface of the fixed cylinder 16. Thus, the second lens cam pin 29 is prevented from coming out of the second lens straight advance hole 23.

On the other hand, the variable magnification engaging portion 55b is
5a are integrally formed on the top coaxially,
It is formed in a truncated conical cross section with a smaller diameter than 5a. The variable-magnification engaging portion 55b is provided in the second lens cam groove 21 in the second direction.
Lens power varying guide 56 and second lens direction changing guide 57
And engage.

FIG. 12 is an exploded view showing the configuration of the second lens cam groove 21 and the moving cylinder rectilinear groove 22 formed on the inner peripheral surface of the rotary cylinder 17.

First, the configuration of the second lens cam groove 21 will be described. A second lens cam pin 29 provided on the second lens barrel 14 is engaged with the second lens cam groove 21. The second lens cam groove 21 includes a second lens variable power guide section 56 (second groove section) for moving the second lens 12 along the optical axis 20 to change the focal length, and a second lens 12 The second lens direction changing guide portion 57 (second groove portion) for changing the moving direction and the second lens 12 are moved to the "storage position C".
And a second lens storage guide portion 58 (first groove portion) for moving the lens to a predetermined position.

The second lens variable power guide section 56 rotates the rotary cylinder 17 toward the "end position" in the "variable rotation range" from the "intermediate position" to the "end position". It is a linear locus that guides the two-lens cylinder 14 so as to retreat toward the image plane 10a.

The second lens direction change guide 57 is provided in the rotation range from the “rotational position B” to the “intermediate position”.
When the is rotated toward the “intermediate position”, the moving direction of the second lens barrel 14 changes, that is, the second lens barrel 14 that has moved toward the subject side changes direction. It is a curved trajectory that is guided so as to retreat toward the image forming surface 10a.

When the rotary barrel 17 is rotated toward the “rotational position B” in the rotation range from the “initial position” to the “rotational position B”, the second lens barrel Reference numeral 14 denotes a linear trajectory that guides the robot to extend toward the subject.

As described above, the second lens variable power guide 56 and the second lens direction change guide 57 are provided with the second lens
The variable power engagement portion 55b of the lens cam pin 29 is engaged, and the storage engagement portion 55a is engaged with the second lens storage guide portion 58.

For this reason, the second lens variable power guiding section 56
As shown in FIG. 13, first tapered surfaces 56a
And the second tapered surface 56b are formed, and only the variable-magnification engaging portion 55b is formed so as to contact the second tapered surface 56b (the storage engaging portion 55a is
It does not come into contact with the tapered surface 56a. ).

More specifically, the second lens variable power guide unit 5
6, the second taper surface 56b has the same inclination angle as the outer peripheral surface of the variable power engaging portion 55b, and the width F at the lower end thereof is equal to the width of the bottom of the variable power engaging portion 55b. G
It is formed with the same width as. On the other hand, the first taper surface 56a has the same inclination angle as the outer peripheral surface of the storage engagement portion 55a, but the width H of the lower end portion is larger than the width I of the bottom portion of the storage engagement portion 55a. It is formed with a large width. Therefore, the second lens variable power guide unit 5
6, the cam groove engaging portion 55 is provided with a variable-magnification engaging portion 55b at the tip.
Only the second tapered surface 56b is in contact with the second tapered surface 56b (the storage engagement portion 55
a and the first tapered surface 56a are not in contact with each other because a gap is formed between them. ).

The second lens direction changing guide 57 has the same configuration as the second lens variable power guide 56. That is, the first tapered surface and the second tapered surface are formed on both wall surfaces, and the cam groove engaging portion 55 is configured such that only the variable-magnification engaging portion 55b on the distal end side is the second lens direction changing guide portion 57. It comes into contact with both wall surfaces (because a gap is formed between the storage engagement portion 55a and both wall surfaces of the second lens direction change guide portion 57, they do not come into contact with each other).

On the other hand, the second lens housing and guiding portion 58 is
As shown in FIG. 4, the both wall surfaces 58a are formed with a taper, and the cam groove engaging portion 55 has only the housing engaging portion 55a.
It is formed so that it may contact both wall surfaces 58a (it does not contact both wall surfaces 58a of the variable-magnification engagement portion 55b).

More specifically, the second lens storage guide unit 5
8, the two wall surfaces 58a have inclination angles of the cam groove engaging portions 55.
Are formed at the same inclination angle as the peripheral surface of the storage engagement portion 55a, and the width J of the opening is formed to be the same width as the width I of the bottom of the storage engagement portion 55a. Therefore, in the second lens storage guide portion 58, only the storage engagement portion 55a on the base end side of the cam groove engagement portion 55 abuts on both wall surfaces 58a of the second lens storage guide portion 58 (variable magnification). A predetermined gap is formed between the joint portion 55b and the two wall surfaces 58a of the second lens housing guide portion 58, so that they do not abut each other.)

According to the second lens cam groove 21 configured as described above, when the rotary cylinder 17 is rotated from the “initial position” to the “rotation position B”, the cam groove of the second lens cam pin 29 is formed. The engagement part 55 is provided with a second lens storage guide part 58.
To move the second lens barrel 14 toward the subject. At this time, the cam groove engaging portion 55 is
5a comes into contact with and slides on both wall surfaces 58a of the second lens storage guide portion 58 (the variable-magnification engagement portion 55b does not come into contact).

When the rotary cylinder 17 is rotated from the “rotational position B” to the “intermediate position”, the cam groove engaging portion 55 of the second lens cam pin 29 causes the second lens direction changing guide 57 to move. By sliding, the moving direction of the second lens barrel 14 is changed. That is, the second lens barrel 14 is moved from the subject side toward the image plane 10a. At this time, the cam groove engaging portion 55 slides with its variable-magnification engaging portion 55b abutting against both wall surfaces of the second lens direction changing guide portion 57 (the housing engaging portion 55a does not abut). .

When the rotary cylinder 17 is further rotated from the “intermediate position” to the “end position”, the cam groove engaging portion 55 of the second lens cam pin 29 slides the second lens variable power guide portion 56. Then, the second lens barrel 14 is moved in a direction in which the second lens barrel 14 is retracted toward the imaging surface 10a. At this time, the cam groove engaging portion 55 slides when its variable-magnification engaging portion 55b abuts on the second tapered surface 56b of the second lens variable-magnification guide portion 56 (the storage engaging portion 55a abuts). Zu.).

As described above, the sliding of the cam groove engaging portion 55 of the second lens cam pin 29 between the second lens variable power guiding portion 56 and the second lens housing guiding portion 58 of the second lens cam groove 21 is performed. By changing the surface, abrasion of the cam pins can be effectively suppressed.

Since the second lens variable power guide 56 needs to operate the second lens barrel 14 accurately at the time of photographing, it is required to have high precision in its manufacture. On the other hand, since the second lens storage guide section 58 does not affect the photographing, the second lens storage guide section 58 is not required to be as accurate as the second lens variable magnification guide section 56. Therefore, the second lens variable power guide 56 is manufactured with high accuracy, and the second lens housing guide 58 is made rough, so that accuracy control is facilitated, productivity is improved, and manufacturing cost is reduced. Can be achieved.

In the second lens direction changing guide 57, the movement trajectory of the second lens cam pin 29 is curved toward the object side. At this time, as shown in FIG. The radius of curvature _Rb of the movement locus (the movement locus that passes through the image forming surface side of the movement locus) is smaller than that of the storage engagement portion 55a because the portion 55b has a smaller diameter than the storage engagement portion 55a. larger than the radius of curvature R _a of the movement locus of the (moving track most through the imaging surface side of the moving track). As described above, the second lens barrel 14 can be smoothly turned by engaging the variable power engaging portion 55b having a large radius of curvature and sliding.

Next, the structure of the moving cylinder straight advance groove 22 will be described. The rectilinear groove engaging portion 25C of the moving cylinder cam pin 25 is engaged with the moving cylinder rectilinear groove 22. As shown in FIG. 12, the moving cylinder rectilinear groove 22 is formed along the optical axis 20 and intersects with the second lens variable power guide portion 56 of the second lens cam groove 21.

As shown in FIG. 15, the depth K of the rectilinear groove 22 for the movable cylinder is smaller than the depth L of the cam groove 21 for the second lens. Thus, the cam groove engaging portion 55 of the second lens cam pin 29 that slides on the second lens variable power guide portion 56 of the second lens cam groove 21 is prevented from entering the moving cylinder straight advance groove 22. You.

On the other hand, as described above, the moving cylinder straight groove 2
2 of the moving cylinder cam pin 25 engaging with the linear groove engaging portion 25
C is formed in an elongated circular plate shape. The length M of the rectilinear groove engaging portion 25C is formed to be longer than the length N of the intersection between the moving cylinder rectilinear groove 22 and the second lens cam groove 21. This prevents the rectilinear groove engaging portion 25C of the moving cylinder cam pin 25 that slides in the moving cylinder rectilinear groove 22 from entering the second lens cam groove 21 or being caught in the intersection.

The operation of the lens apparatus 2 according to the present embodiment having the above-described structure is as follows.

First, when the rotary barrel 17 is rotated, the movable barrel 15, the first lens barrel 13, and the second lens barrel 1
4 will be described.

When the lens device 2 is in the retracted position, as shown in FIG. 3, the moving barrel 15 and the first lens barrel 13
Each is accommodated in the fixed cylinder 16.

By driving the zoom motor 19, the rotary cylinder 17
Is rotated from the “initial position” to the “end position”, the rotation of the rotary barrel 17 is transmitted to the movable barrel cam pin 25 via the movable barrel straight advance groove 22. Thereby, the movable barrel 15 rotates in conjunction with the rotating barrel 17.

The movable cylinder 15 has a movable cylinder cam pin 25 provided on the outer peripheral portion thereof, and a movable cylinder straight groove 22 formed in the rotary cylinder 17 and a movable cylinder cam pin 25 formed in the fixed cylinder 16. Since it is engaged with the cam hole 24, when it rotates,
It moves in the optical axis direction while rotating with respect to the fixed barrel 16.

On the other hand, in the first lens barrel 13, the first lens cam pins 28 provided on the outer peripheral portion thereof are engaged with the first lens cam grooves 26 formed in the movable barrel 15. The linear guide groove 27 formed on the peripheral surface is
When the movable barrel 15 rotates, the movable barrel 1 is engaged with the linear guide protrusion 30 formed on the lens barrel 14.
6 moves straight along the optical axis 20.

The second lens barrel 14 has a second lens cam pin 29 provided on an outer peripheral portion thereof, and a second lens cam groove 21 formed on an inner peripheral surface of the rotary barrel 17 and a fixed barrel 16. When the rotary barrel 17 rotates, it moves linearly along the optical axis 20 in conjunction with the rotation of the rotary barrel 17.

Next, the first lens barrel 13, the second lens barrel 14, and the moving barrel 1 when the rotating barrel 17 is rotated.
The movement locus such as 5 will be described.

FIG. 16 is an explanatory diagram showing the movement trajectories of the first lens barrel 13, the second lens barrel 14, the movable barrel 15, and the like.

[0086] In the figure, the thick line (E) indicates the first line.
The movement trajectory of the lens barrel 13 is shown.
The movement locus of the second lens barrel 14 is shown. Further, a thin line (G) represents a movement locus of the first lens barrel 13 with respect to the moving barrel 15, and a thin line (J) represents a movement locus of the moving barrel 15.

As shown in the figure, when the lens device 2 is in the retracted position, the movable barrel 15 is located at the "retreat position K". Further, the second lens barrel 14 is located at the “storage position C” closest to the image plane, and the first lens barrel 13 is
The first lens barrel 13 is located at the “retreat position H” with respect to the moving barrel 15 (the first barrel 13 is located at the “retracted position D”) which is close to the lens barrel 14.

First, when the rotary barrel 17 rotates from the “initial position” to the “intermediate position”, the first lens barrel 13
And the movement locus of the moving cylinder 15 will be described.

During the rotation of the rotary barrel 17 from the “initial position” to the “rotational position A”, the first lens barrel 13 has the first lens cam pin 28 provided on the outer periphery thereof and the first lens cam groove. Slide the first lens storage preparation guide section 42 of FIG. As a result, the first lens barrel 13 moves with respect to the movable barrel 15 in the “retreat position H” of the movement trajectory represented by the thin line (G).
To the "storage preparation position I".

While the rotary barrel 17 rotates from the “rotational position A” to the “intermediate position”, the first lens barrel 13 is provided with a first lens cam pin 28 provided on the outer peripheral portion thereof. The first lens movement preventing portion 43 of the cam groove 26 slides. As a result, the first lens barrel 13 is moved
Is prevented from moving in the optical axis direction. Accordingly, since the first lens barrel 13 does not move in the optical axis direction with respect to the movable barrel 15 during this time, the first lens barrel 13 moves to the “storage preparation position I” of the movement locus indicated by the thin line (G) with respect to the movable barrel 15. Will be maintained.

On the other hand, while the rotating barrel 17 rotates from the “initial position” to the “intermediate position”, the moving barrel cam pin 25 provided on the outer peripheral portion thereof
4 slides the movable cylinder storage guide section 40. Thereby, the moving cylinder 15 is extended from the “retreat position K” to the “projection position L” in the movement locus represented by the thin line (J).

Here, the first lens barrel 13 is supported by a movable barrel 15. Therefore, while the rotating barrel 17 rotates from the “initial position” to the “intermediate position”, the first lens barrel 13 moves the moving barrel 15 and the moving barrel 15.
Move along the optical axis 20 by the amount of the extension of the first lens barrel 13 with respect to. That is, the first lens barrel 13 moves the rotating barrel 17 from the “initial position” to the “rotating position A”.
Is rotated from the “storage position D” to the “position M” in the movement locus represented by the bold line (E).
When 7 rotates from “rotational position A” to “intermediate position”,
The movement trajectory represented by the bold line (E) is moved from the “position M” to the “position O”.

Next, when the rotary barrel 17 rotates from the “initial position” to the “intermediate position”, the second lens barrel 14
Will be described.

During the rotation of the rotary barrel 17 from the “initial position” to the “rotational position B”, the second lens barrel 14 is provided with the second lens cam pin 29 provided on the outer peripheral portion thereof. Then, the second lens storage guide portion 58 of FIG.
At this time, the second lens cam pin 29 is configured such that the storage engagement portion 55 a of the cam groove engagement portion 55 is in the second lens storage guide portion 58.
And slide. Thereby, the second lens barrel 14
Represents the “evacuation position C” of the movement locus represented by the thick line (F).
To "position P".

During the rotation of the rotary barrel 17 from the “rotational position B” to the “intermediate position”, the second lens barrel 14 has the second lens cam pin 29 provided on the outer peripheral portion thereof. Second lens direction changing guide portion 57 of cam groove 21
Slide.

At this time, the second lens cam pin 2
9, when the rotary cylinder 17 rotates to the “rotation position B”, the engagement of the storage engagement portion 55a is released, and the variable power engagement portion 55b
Are engaged with the second lens direction changing guide 57. The variable-magnification engaging portion 55b slides on the second lens direction changing guide portion 57, so that the second lens barrel 1
4 is fed from the “position P” of the movement trajectory represented by the thick line (F) to the “position N”.

Incidentally, since the variable-magnification engaging portion 55b of the second lens cam pin 29 which engages with the second lens direction changing guide portion 57 is formed to have a smaller diameter than the housing engaging portion 55a. The radius of curvature of the moving trajectory (the radius of curvature of the moving trajectory that passes through the image forming surface side of the moving trajectory) is the radius of curvature of the moving trajectory of the storage engagement portion 55a (the moving trajectory that passes through the image forming surface side of the moving trajectory). Radius of curvature).
Thus, the variable power engaging portion 55b having a large radius of curvature is
Since the second lens barrel 14 slides by engaging with the lens direction changing portion 57, the direction can be changed smoothly. In addition, the rotational load of the rotary cylinder 17 can be reduced.

As described above, the rotating cylinder 17 is in the "middle position".
As shown in FIG. 4, the lens device 2 is in the telephoto position. In this state, the moving cylinder 15 is located at the “projecting position L”. Then, the first lens barrel 13
Is located at “position O”, and the second lens barrel 14 is positioned at “position N”.
Located in.

After the lens device 2 is in the telephoto position, the rotary cylinder 17 is rotated in the "variable rotation range".

While the rotating barrel 17 is rotating in the “magnification rotation range”, the moving barrel cam pin 25 provided on the outer periphery of the movable barrel 15 is moved by the movable barrel cam hole 24 into the movable barrel movement blocking part 41. Slide. For this reason, the movable barrel 15 is
Is prevented from moving in the optical axis direction. Accordingly, the moving cylinder 15 does not move in the optical axis direction during this time, and is maintained at the “projecting position L” of the moving trajectory represented by the thin line (J).

The first lens barrel 13 has a first lens barrel cam pin 28 provided on an outer peripheral portion thereof while the rotary barrel 17 rotates in the “magnification rotation range”.
The first lens variable power guide 44 is slid. For this reason, the first lens barrel 13 moves the optical axis 20 with respect to the movable barrel 15 by an amount corresponding to the displacement of the first lens variable power guide 44 in the optical axis direction.
Move along.

Further, while the rotary barrel 17 rotates in the "magnification rotation range", the second lens cam pin 29 provided on the outer periphery of the second lens barrel 14 engages with the second lens cam groove 21.
The second lens variable power guide 56 is slid. For this reason, the second lens barrel 14 is moved according to the displacement of the second lens variable power guide 56 in the optical axis direction. At this time, the second lens cam pin 29 slides with the variable power engaging portion 55b of the cam groove engaging portion 55 engaging with the second lens variable power guiding portion 56.

At the time of zooming, the first lens barrel 13 and the second lens barrel 14 are moved along the optical axis 20 so that their distances are different.

During this time, the second lens barrel 14 is pushed by the spring 37 in the optical axis direction, so that the second lens cam pin 29
The play between the second lens cam groove 21 and the second lens cam groove 21 is absorbed, and
The inclination with respect to the fixed cylinder 16 is also corrected. On the other hand, since the bottom surface of the rectilinear guide groove 27 is pressed in the radial direction by the rectilinear guide protrusion 30, the optical axis of the first lens 11 is changed to the optical axis of the second lens 12 during zooming. Tilt to the contrary is suppressed as much as possible. Also, at this time, since the biasing in the radial direction by the straight guide projection 30 is only one regardless of the moving position of the second lens barrel 14, the first lens barrel 1 is always
3 and the second lens barrel 14 can be moved smoothly. In addition, the straight guide projection 30 has a distal end surface 30.
Since c is formed in a spherical shape, it can be brought into contact with the bottom of the straight guide groove 27 at a point, and the resistance during sliding can be reduced as much as possible.

The operation of the lens device 2 according to the present embodiment is as described above. By the way, in the lens device 2 of the present embodiment, the second lens rectilinear hole 2
3 is formed so as to communicate with the moving cylinder cam hole 24. In this manner, the second lens rectilinear hole 23 is moved to the movable cylinder cam hole 24.
The lens device 2 is easy to assemble.

That is, when assembling the lens device 2,
The second lens barrel 14 engages the second lens cam pin 29 provided on the outer peripheral surface thereof with the second lens rectilinear hole 23 formed in the fixed barrel 16. At this time, the lens according to the present embodiment is used. By forming the second lens rectilinear hole 23 so as to communicate with the movable cylinder cam hole 24 as in the device 2, the second lens cam pin 29 is formed by using the movable cylinder cam hole 24.
It can be engaged with the rectilinear hole 23 for the lens.

More specifically, as shown in FIG. 8, one end of the movable cylinder cam hole 24 communicates with the front end of the fixed cylinder 16 via a notch 60 (open end). Therefore, the second lens cam pin 29 is connected to the second lens straight hole 2.
3, the first lens cam pin 29 is fitted into the movable cylinder cam hole 24 through the cutout 60, and the second lens straight hole 23 is inserted through the movable cylinder cam hole 24.
Can be led to. Thereby, as in the conventional case, the second
After the lens barrel 14 is housed and disposed in the fixed barrel 16, the second lens cam pin 29 is inserted into the second lens straight advance hole 23 formed in the fixed barrel 16 and fixed to the second lens barrel 14. The assembly can be performed by a simple operation of fitting the second lens cam pin 29 from the cutout portion 60 without performing the operation.

In the lens device 2 of the present embodiment,
The fixed barrel 16 is formed of an elastically deformable material such as plastic, and the width A of the second lens
The width is slightly smaller than the width B of the rectilinear hole engaging portion 54 of the lens cam pin 29. As a result, the second lens cam pin 29 engaged with the second lens rectilinear hole 23 has its rectilinear hole engaging portion 54 sandwiched from both sides by the edge of the second lens rectilinear hole 23, and the second lens cam pin 29 Asobi between the straight running holes 23 is eliminated. This eliminates backlash when driving the lens, and allows the second lens barrel 14 to be operated with high accuracy.

On the other hand, as described above, the second lens rectilinear
Is formed in communication with the moving cylinder cam hole 24, the moving cylinder cam pin 25 engaged with the moving cylinder cam hole 24
There is a possibility that the lens may enter the lens rectilinear hole 23 or be caught by the communicating portion, but as in the present embodiment,
By forming the cam hole engaging portion 25 </ b> A on the moving cylinder cam pin 25, it is possible to prevent the moving cylinder cam pin 25 from entering the second lens straight-moving hole 23 or being caught.

In the present embodiment, the zoom lens has a two-group configuration. However, the present invention is not limited to this, and a three or more-group configuration may be employed.

The present invention can be applied not only to a zoom lens camera but also to a bifocal camera that switches between a telephoto position, a wide position, and a retracted position, for example.
The present invention can be applied not only to an electronic still camera but also to a silver halide camera.

[0112]

As described above, according to the present invention,
By forming one end of the rectilinear hole to communicate with the cam hole,
A cam pin to be engaged with the rectilinear hole can be fitted into the rectilinear hole using the cam hole. This facilitates the assembly of the lens device. Further, by forming the width of the rectilinear hole smaller than the diameter of the cam pin, the rectilinear hole can sandwich the engaged cam pin, thereby eliminating backlash and improving the driving accuracy when driving the lens. . Further, by forming the guide portion on the cam pin engaging with the cam hole, the cam pin engaging with the cam hole is prevented from entering the straight advance hole.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an external configuration of an electronic still camera.

FIG. 2 is an exploded perspective view of the lens device.

FIG. 3 is a sectional view showing the lens device in a retracted position.

FIG. 4 is a sectional view showing the lens device in a telephoto position;

FIG. 5 is a sectional view showing the lens device in a wide position.

FIG. 6 is a cross-sectional view of the first lens barrel and the second lens barrel cut in a direction orthogonal to the optical axis.

FIG. 7 is a developed view showing a configuration of a first lens cam groove provided in the movable barrel.

FIG. 8 is a developed view showing a configuration of a movable cylinder cam hole and a second lens straight-moving hole provided in a fixed cylinder.

FIG. 9 is a plan view showing the configuration of a moving cylinder cam pin.

FIG. 10 is a side view showing a configuration of a cam pin for the moving cylinder.

FIG. 11 is a front view showing a configuration of a second lens cam pin.

FIG. 12 is an exploded view showing the configuration of a second lens cam groove and a moving cylinder rectilinear groove formed on the inner peripheral surface of the rotary cylinder.

FIG. 13 is a sectional view showing an engagement state between a second lens cam groove and a second lens cam pin.

FIG. 14 is a sectional view showing an engagement state between a second lens cam groove and a second lens cam pin.

FIG. 15 is a cross-sectional view showing a configuration of an intersection of a second lens cam groove and a moving cylinder straight groove.

FIG. 16 is an explanatory diagram showing the movement trajectories of the first lens barrel, the second lens barrel, the moving barrel, and the like.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Electronic still camera, 2 ... Lens device, 10a ... Image forming surface, 11 ... 1st lens, 12 ... 2nd lens, 13 ... 1st
Lens barrel, 14 ... second lens barrel, 15 ... moving barrel, 16 ...
Fixed cylinder, 17: rotating cylinder, 19: zoom motor, 20: optical axis, 21: cam groove for second lens, 22: rectilinear groove for moving cylinder, 23: rectilinear hole for second lens, 24: cam for moving cylinder Hole, 25: cam pin for moving cylinder, 25A: cam hole engaging portion,
25B: guide groove engaging portion, 25C: straight groove engaging portion, 26
... First lens cam groove, 27: straight guide groove, 28: first lens cam pin, 29: second lens cam pin, 3
0: linear guide projection, 33: second lens frame, 34: focus motor, 37: spring, 38: arm, 40: movable cylinder storage guide section, 41: movable cylinder movement prevention section, 42: first lens storage preparation guide Part, 43... First lens movement prevention part, 4
4 First lens variable power guide, 49 Guide groove, 54 Straight hole engaging part, 55 Cam groove engaging part, 55a Storage engaging part, 55b Variable power engaging part, 56 Second Lens zoom guide, 56a: first tapered surface, 56b: second tapered surface, 5
8: second lens storage guide, 58a: tapered surface, 60:
Notch

[Procedure amendment]

[Submission date] March 8, 2000 (200.3.8)

[Procedure amendment 1]

[Document name to be amended] Drawing

[Correction target item name] All figures

[Correction method] Change

[Correction contents]

FIG.

FIG. 2

FIG. 3

FIG. 4

FIG. 5

FIG. 9

FIG. 6

FIG. 7

FIG. 10

FIG. 13

FIG. 8

FIG. 11

FIG.

FIG. 14

FIG.

FIG. 16

Continuation of the front page (72) Inventor Masaaki Orimoto 3-11-46 Izumi, Asaka-shi, Saitama F-term in Fujisha Shin Film Co., Ltd. (Reference) 2H044 BD08 BD09 BD10 BD15 EA03 EA08

Claims (2)

[Claims] 1. A lens device in which a cam hole having an open end and a rectilinear hole are formed on a peripheral surface of a cylindrical body, wherein the cylindrical body is formed of an elastically deformable material, and one end of the rectilinear hole is formed by the cam. A lens device that communicates with the hole and that has a width smaller than a diameter of a cam pin that engages with the rectilinear hole so that the cam pin is sandwiched between both edges of the rectilinear hole. . 2. A guide groove is formed on a peripheral surface of the cylindrical body along a peripheral edge of the cam hole, and a guide portion engaging with the guide groove is provided on a cam pin engaging with the cam hole. 2. The lens device according to claim 1, wherein a width of the portion is formed to be larger than a width of the rectilinear hole at a communication position between the rectilinear hole and the cam hole.