JPH11258663A - Camera with optical unit - Google Patents

Abstract

(57) Abstract: An object of the present invention is to provide a camera having an optical unit in which a photographing optical system and an optical finder are combined, and to arrange a motor in the optical unit with high space efficiency. SOLUTION: An image pickup optical system which is constituted at least by a first lens group and a second lens group and forms an object image, an image pickup means which picks up an object image via the image pickup optical system,
It has a first driving means for driving the lens group back and forth, a second driving means for driving the second lens group back and forth, and an optical finder for forming a visual field image, wherein the photographing optical system and the optical finder are arranged side by side. Then, the first driving means and the second driving means are respectively arranged in two spaces formed in a direction intersecting the arrangement.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a camera having an optical unit in which a photographing optical system and an optical finder are combined. In particular, the present invention relates to a technique for saving the entire space by arranging a lens driving mechanism of an imaging optical system in combination with an imaging optical system and an optical finder.

[0002]

2. Description of the Related Art Conventionally, Japanese Patent Application Laid-Open No. 9-163196 discloses an example of an internal layout of an electronic camera. FIG. 6 is a diagram for explaining this internal layout. In FIG. 6, a photographing optical system 81 is arranged on the left side when viewed from the front of the electronic camera 80. An image sensor 82 is arranged on the optical axis of the photographing optical system 81. A battery 83 is arranged behind the photographing optical system 81 in the longitudinal direction.

Further, a photographing optical system 81 and a battery 83
, An elongated optical finder 84 is arranged. A flash unit 85 is disposed on the right side of the objective side lens of the optical finder 84. Behind the flash unit 85, a printer 86 and a DC / DC converter 87 are arranged substantially in a line. A roll paper 88 for a printer and a motor 89 for a printer are arranged in a space surrounded in a U-shape by the flash unit 85, the printer 86, and the DC / DC converter 87. With such a lean layout configuration, the overall size of the electronic camera 80 can be reduced, and the portability and operability of the electronic camera 80 can be further improved.

[0004]

When an autofocus function or a power zoom function is added to the above-described photographing optical system 81, it is necessary to newly provide a motor for focus control, a motor for zoom drive, and the like. Occurs. In this case, there is a problem that the outer shape of the electronic camera becomes larger by the newly provided space for installing the motor group.

[0005] These motor groups are connected to a photographing optical system 81.
When it is arranged near the camera, it becomes difficult to arrange the photographing optical system 81 and the optical finder 84 close to each other. As a result, there arises a problem that the distance between the optical axes of the photographing optical system 81 and the optical finder 84 increases, and the parallax of the optical finder 84 increases. In order to solve these problems, an object of the present invention is to provide a camera in which a motor and the like are arranged in an optical unit including a photographing optical system and an optical finder with high space efficiency.

According to a second aspect of the present invention, in addition to the object of the first aspect, the guide shaft of the photographing optical system is arranged in the optical unit with good space efficiency, and rattling when driving the lens is reduced. It is an object to provide a camera that can be suppressed. According to the third aspect of the present invention, in addition to the object of the first aspect, there is provided a camera capable of arranging a lens position detection sensor in the optical unit with high space efficiency and improving the lens position detection accuracy. The purpose is to provide.

According to a fourth aspect of the present invention, in addition to the object of the first aspect, it is an object of the present invention to provide a camera in which an interlocking mechanism between a photographing optical system and an optical finder is provided in the optical unit with high space efficiency. And According to a fifth aspect of the present invention, in addition to the object of the first aspect, it is an object of the present invention to provide a camera in which the performance balance of a driving unit of a photographing optical system is optimized in order to improve focusing accuracy. According to a sixth aspect of the present invention, in addition to the object of the first aspect, it is an object of the present invention to provide a camera in which the performance balance of a driving unit of a photographing optical system is optimized in order to improve zoom performance.

[0008]

According to a first aspect of the present invention, there is provided a photographing optical system which includes at least a first lens group and a second lens group and forms a subject image, and a photographing optical system. Imaging means for imaging a subject image via an optical system;
It has a first driving means for driving the lens group back and forth, a second driving means for driving the second lens group back and forth, and an optical finder for forming a visual field image, wherein the photographing optical system and the optical finder are arranged side by side. The first drive means and the second drive means are respectively arranged in two spaces formed in a direction intersecting the arrangement.

In general, since the photographing optical system has a round shape such as a cylindrical shape, when the photographing optical system and the optical finder are arranged, two empty spaces are generated along the roundness of the photographing optical system. By arranging the first driving means and the second driving means in these two empty spaces, the size of the optical unit can be reduced. Further, with the above configuration, the photographing optical system and the optical finder can be arranged close to each other, so that the parallax of the optical finder can be suppressed to be small.

According to a second aspect of the present invention, in a camera having the optical unit according to the first aspect,
A guide shaft shared by the first lens unit and the second lens unit is arranged in an intermediate space surrounded by the photographing optical system, the finder optical system, the first driving unit, and the second driving unit. I do.

In general, an intermediate portion surrounded by a photographing optical system, an optical finder, first driving means and second driving means includes:
Free space is created. By arranging a long guide shaft so as to be partially inserted into the intermediate space, it is possible to reduce the size of the optical unit. Further, by disposing the guide shaft in the intermediate space in this way, the guide shaft and the first drive unit are arranged close to each other. For this reason, the distance between the "position where the force is applied by the first driving means" and the "guide shaft" is shortened, and the influence of the reaction force acting between them is reduced. As a result, bending deformation, dynamic frictional force, and the like generated in the first lens group are reduced, and it is possible to reduce rattling and the like accompanying the sliding movement of the first lens group. For the same reason, it is also possible to reduce rattling or the like associated with the sliding movement of the second lens group.

According to a third aspect of the present invention, in a camera having the optical unit according to the first or second aspect, a first sensor for detecting a lens position of the first lens group is provided. And a second sensor for detecting the lens position of the second lens group. The first sensor (or the second sensor) is provided in a space formed along the lens optical axis direction from the position of the first driving means. Placed in a space formed along the optical axis direction of the lens from the position of the second driving means,
A second sensor (or a first sensor) is provided.

Usually, the first driving means and the second driving means have a shorter overall length than the photographing optical system and the optical finder. Therefore, an empty space is created along the optical axis of the lens from the position of these driving means. By arranging the first sensor and the second sensor in this empty space, the size of the optical unit can be reduced. In particular, in the configuration as in claim 2, the first sensor and the second sensor are arranged near the guide shaft in the intermediate portion. In this case, the first sensor and the second sensor detect the lens position near the guide axis. Therefore, the detection value of the lens position is unlikely to include an error such as the deflection of the lens group, and the detection accuracy of the first sensor and the second sensor can be further increased.

According to a fourth aspect of the present invention, there is provided a camera having the optical unit according to any one of the first to third aspects, wherein the first driving means and the second driving means are provided. A zoom control unit that controls the zoom amount of the photographing optical system, a focus control unit that controls the first drive unit to change the focal position of the photographing optical system, and a driving force of the second drive unit. An interlocking mechanism for transmitting the light to the optical finder through the movement of the second lens group and zooming the lens of the optical finder is provided.

In such a configuration, the driving force of the second driving means is transmitted to the optical finder through the second lens group. Therefore, there is no need to separately provide a detour path for transmitting the driving force from the second driving means to the optical finder, and the optical unit can be reduced in size. Further, as described above, the three components of the photographing optical system, the optical finder, and the second driving unit are radially arranged close to each other. Therefore, it is possible to transmit the driving force of the second driving means to the photographing optical system and the optical finder with low loss.

Furthermore, since the second lens group and the optical finder are connected by an interlocking mechanism, it is possible for the optical finder to absorb natural vibrations and the like of the second lens group to some extent. Therefore, the zoom movement of the second lens group can be further smoothed. In particular, claim 2
In the configuration described above, since the guide shaft is disposed at an intermediate portion between the photographing optical system and the optical finder, the driving force transmitted to the interlocking mechanism passes near the guide shaft. At this time, the “excessive force other than sliding the second lens group” is temporarily absorbed by the guide shaft, so that the driving force can be efficiently transmitted to the optical finder side.

According to a fifth aspect of the present invention, in a camera having the optical unit according to the fourth aspect,
The first driving means has a finer control resolution than the second driving means. With such a configuration, it is possible to finely position the first lens group via the first driving unit. Therefore, the focusing accuracy of the photographing optical system can be further improved.

According to a sixth aspect of the present invention, in the camera having the optical unit according to the fourth or fifth aspect, the second driving means has a higher thrust and a longer length than the first driving means. It is a stroke. In such a configuration, since a high thrust can be obtained from the second driving unit, the second lens group can be moved at a high speed. Therefore, it is possible to increase the zoom speed of the photographing optical system. Further, since the second driving means moves the second lens group with a long stroke, it is possible to increase the zoom magnification of the photographing optical system.

[0019]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram illustrating an appearance of an electronic camera according to the present embodiment. In FIG. 1, an electronic camera is a camera body 1 provided with a liquid crystal monitor and the like.
And a rotating unit 2 rotatably attached to the camera body 1. An optical unit 3 is disposed inside the rotating unit 2.

FIG. 2 is a sectional view of the optical unit 3 shown in FIG.
It is explanatory drawing which shows the -A 'cross section. In FIG. 2, the optical unit 3 is schematically constituted by an arrangement of a photographing optical system 10 and an optical finder 30. This photographing optical system 10 includes:
The first lens group 11 and the second lens group 12 are arranged in order from the objective side.
And a third lens 13. By mainly moving the second lens group 12 and slightly moving the first lens group 11 for correction, the zoom magnification (focal length) of the photographing optical system 10 changes.

By driving the first lens group 11 back and forth by itself, the focus of the photographing optical system 10 is adjusted. An image sensor 14 is disposed behind the third lens 13 via an infrared cut filter 14a.
The third lens 13, the filter 14a, and the imaging device 14 are integrally held by a CCD holder 14b.

The photographing optical system 10 and the optical finder 30
The guide shaft 21 is arranged in the gap between the guide shaft 21 and the guide shaft 21. A rotation stop shaft 22 is disposed in a gap between the casing 3a of the optical unit 3 and the photographing optical system 10. Both ends of the guide shaft 21 and the rotation stop shaft 22 are fixed by the casing 3a and the CCD holder 14b, respectively.
On the other hand, the above-described first lens group 11 includes the first lens chamber 11
The lens periphery is held by a. This first lens chamber 1
The grips 11z protrude from both sides of 1a. The first lens group 11 is positioned at the center of the photographing optical path by the gripping portions 11z gripping the guide shaft 21 and the rotation stopping shaft 22, respectively.

The periphery of the second lens group 12 is held by a second lens chamber 12a. A grip portion 12z protrudes from both sides of the second lens chamber 12a. The gripping portion 12z grips the guide shaft 21 and the rotation stop shaft 22, whereby the second lens group 12 is positioned at the center of the photographing optical path. Immediately before the second lens group 12, a shutter unit 12b is arranged. This shutter unit 1
2b is fixed to the second lens chamber 12a and moves back and forth with the second lens group 12.

Further, the gripper 12 of the second lens chamber 12a
The follower pin 12c protrudes from z. The follower pin 12c is fitted into the cam groove of the cam plate 23.
The cam plate 23 moves as the follower pin 12c moves back and forth. The remaining two cam grooves of the cam plate 23 have follower pins 31c and 32 on the optical finder 30 side.
c is fitted respectively. This follower pin 31c
Are projected from the first finder lens 31 of the optical finder 30. In addition, the follower pin 32 c protrudes from the second finder lens 32 of the optical finder 30.

With such a cam plate 23, the first finder lens 31 and the second finder lens 32 are zoomed in conjunction with the zoom movement of the second lens group 12. A prism 33 is disposed behind the second finder lens 32. The prism 33 erects a field image formed by the optical viewfinder 30 and guides it to the eyepiece window.

FIG. 3 is an explanatory view showing a vertical section taken along line BB 'shown in FIG. FIG. 4 is an explanatory view showing a vertical section taken along line CC ′ shown in FIG. As shown in FIGS. 3 and 4, with respect to the arrangement of the photographing optical system 10 and the optical finder 30,
The first motor 15
And the second motor 18 are respectively arranged. A guide shaft 21 is disposed in an intermediate space surrounded by the photographing optical system 10, the optical finder 30, the first motor 15, and the second motor 18.

FIG. 5 is an explanatory view showing a vertical section taken along the line DD 'shown in FIG. As shown in FIG. 5, the first lens chamber 11
The gripper 11z of a is formed in a U-shape, and grips the guide shaft 21 at two places. A screw receiving portion 11d is protruded behind the grip portion 11z. The screw 15a of the first motor 15 is in contact with the screw receiving portion 11d. On the other hand, one end of a spring 17 is fixed to the front side of the grip portion 11z, and an urging force for pulling the first lens chamber 11a backward is applied.

A photo-interrupter 16 is arranged in a space in front of the first motor 15 along the optical axis of the photographing optical system. Between the photointerrupters 16, the gripper 1
The slit 11e projecting at 1z passes. The photo interrupter 16 is a position sensor for detecting the origin position of the first lens group 11. The slide mechanism of the first lens group 11 is set to (1) stroke length 7 mm (2) thrust 50 gf (3) control resolution 1.5 μm.

On the other hand, the holding portion 12z of the second lens chamber 12a
Are formed in an inverted U-shape, and grip the guide shaft 21 at two places. The top 18b is connected to the grip 12z via a connection 12d. The top 18b is the second motor 1
The ball screw 18a moves forward and backward by rotating the ball screw 18a in the forward and reverse directions. In addition, a photo interrupter 19 is disposed in a front space from the position of the second motor 18 along the photographing optical axis. The space between the photo interrupters 19 is
The slit 12e projecting at z passes through. The photo interrupter 19 is a position sensor for detecting the origin position of the second lens group 12.

The slide mechanism of the second lens group 12 has the following settings: (1) stroke length: 20 mm (2) thrust: 200 gf (3) control resolution: 10 μm .

(Effects of this Embodiment) According to the above-described configuration, in this embodiment, the first empty space intersecting with the arrangement of the photographing optical system 10 and the optical finder 30 is
The motor 15 and the second motor 18 are arranged respectively. Therefore, the first motor 15 and the second motor 18 can be arranged with good space efficiency, and the optical unit 3 can be reduced in size.

In this embodiment, the photographing optical system 10, the optical finder 30, the first motor 15, and the second motor 18
The guide shaft 21 is arranged in an intermediate space surrounded by the above.
Therefore, it is possible to arrange the guide shaft 21 with good space efficiency and to reduce the size of the optical unit 3. Further, by such a central arrangement of the guide shaft 21, the "point of action of the force of the first motor 15" and the "guide shaft 21" are close to each other.
As a result, the influence of the reaction force generated between them is reduced, and the first
Deflection, dynamic frictional force, and the like generated in the lens chamber 11a can be reduced. Therefore, the first lens group 11 can be slid smoothly.

Further, by the center arrangement of the guide shaft 21 described above, "the point of action of the force of the second motor 18" and "the guide shaft 2"
1 ”is close. Therefore, the influence of the reaction force generated between them is reduced, and the bending, dynamic frictional force, and the like generated in the second lens chamber 12a can be reduced. Therefore,
The second lens group 12 can be slid smoothly.

Further, in the present embodiment, the first motor 15
The photointerrupter 16 and the photointerrupter 19 are arranged in a space in front of the second motor 18. Therefore, the photointerrupters 16 and 19 can be arranged with good space efficiency, and the optical unit 3 can be reduced in size. In particular, such an arrangement of the photointerrupters 16 and 19 allows the photointerrupters 16 and 1
9 and the guide shaft 21 can be arranged close to each other. For this reason, the positions of the photointerrupters 16 and 19 are less likely to be affected by bending of the lens group and the like, and the detection accuracy of the photointerrupters 16 and 19 can be improved.

In the present embodiment, the driving force of the second motor 18 is transmitted to the optical finder 30 via the follower pin 12c of the second lens chamber 12a. Therefore, there is no need to separately provide a detour path for transmitting the driving force to the optical finder 30, and the optical unit 3 can be reduced in size. The three components of the second motor 18, the second lens chamber 12 a, and the optical finder 30 are arranged radially around the guide shaft 21. Therefore, the second
The driving force of the motor 18 can be stably transmitted to the second lens group 12 and the optical finder 30 with low loss.

Further, in the present embodiment, the first motor 15
The control resolution on the side is set smaller than the control resolution on the second motor 18 side. Therefore, the focusing position of the photographing optical system 10 can be finely positioned, and the focusing accuracy of the photographing optical system 10 can be further improved.
Further, in the present embodiment, the thrust on the second motor 18 side is set to be larger than the thrust on the first motor 15 side. Therefore, the zoom movement of the second lens group 12 can be accelerated, and the zoom movement of the imaging optical system 10 can be completed in a short time.

Further, in the present embodiment, the second motor 18
Is set longer than the stroke on the first motor 15 side. Therefore, the moving distance of the second lens group 12 becomes longer, and the zoom magnification of the photographing optical system 10 can be further increased. In the above-described embodiment, the electronic camera is configured by arranging the imaging element 14, but the present invention is not limited to this configuration. For example, a silver halide camera may be configured by arranging a film feeding mechanism or the like as an imaging unit. Further, in the above-described embodiment, the photographing optical system 10 including the three lens units has been described, but the present invention is not limited to this configuration. In general, the present invention can be applied to an imaging optical system having an N-group (N ≧ 2) lens configuration.

[0038]

According to the first aspect of the present invention, the photographing optical system and the optical finder are arranged side by side, and two spaces formed in a direction intersecting with the arrangement are provided.
The first driving means and the second driving means are respectively arranged. Therefore, the first driving unit and the second driving unit can be arranged with good space efficiency, and the size of the optical unit can be reduced. Further, since the photographing optical system and the optical finder can be arranged close to each other, the distance between the optical axes of the photographing optical system and the optical finder does not increase, and the parallax of the optical finder can be reduced. .

(Claim 2) In the invention according to claim 2,
A guide shaft is arranged in an intermediate space generated by being surrounded by the photographing optical system, the finder optical system, the first driving unit, and the second driving unit. For this reason, the guide shaft can be arranged with good space efficiency, and the optical unit can be reduced in size.

Further, since the distance between the guide shaft and the first driving means is short, it is possible to suppress the deflection and the dynamic frictional force and to suppress the rattling accompanying the sliding movement of the first lens unit. Further, since the distance between the guide shaft and the second driving means is short, it is possible to suppress the deflection and the kinetic frictional force and to suppress the rattling accompanying the sliding movement of the second lens group.

(Claim 3) In the invention according to claim 3,
The first sensor and the second sensor are arranged in an empty space generated along the optical axis of the first driving unit and the second driving unit. Therefore, the first sensor and the second sensor can be arranged with good space efficiency, and the optical unit can be reduced in size. In particular, in the configuration as in claim 2, the guide shaft is arranged near the first sensor and the second sensor. Therefore, the positions of the first sensor and the second sensor are hardly affected by the deflection of the outer frame of the lens group, and the detection accuracy of the lens position can be further improved.

(Claim 4) In the invention according to claim 4,
The driving force of the second driving means is transmitted to the optical finder through the second lens group. Therefore, there is no need to separately provide a detour path for transmitting the driving force to the optical finder, and the optical unit can be reduced in size. Further, since the photographing optical system, the optical finder and the second driving means are arranged radially close to each other, the driving force of the second driving means is transmitted to the second lens group and the optical finder with low loss. It is also possible to do.

(Claim 5) In the invention according to claim 5,
Since the first drive unit can finely position the first lens group, the focusing accuracy of the photographing optical system can be improved.

(Claim 6) In the invention according to claim 6,
Since the second lens group moves at a high speed due to the high thrust from the second driving means, it is possible to increase the zoom speed of the photographing optical system. Further, since the second drive means can move the second lens group with a long stroke, it is possible to increase the zoom magnification of the photographing optical system.

[Brief description of the drawings]

FIG. 1 is a perspective view illustrating an appearance of an electronic camera according to an embodiment.

FIG. 2 is an explanatory diagram showing a cross section taken along line AA ′ in FIG. 1;

FIG. 3 is an explanatory diagram showing a BB ′ vertical cross section shown in FIG. 2;

FIG. 4 is an explanatory view showing a vertical section taken along line CC ′ shown in FIG. 2;

FIG. 5 is an explanatory diagram showing a DD ′ vertical cross section shown in FIG. 2;

FIG. 6 is a diagram showing an internal layout of a conventional electronic camera 80.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Camera body 2 Rotating part 3 Optical unit 10 Imaging optical system 11 1st lens group 11a 1st lens room 11d Screw receiving part 11e Slit 12 2nd lens group 12a 2nd lens room 12b Shutter unit 12c Follower pin 12d Connecting part 13th 3 lens 14 imaging element 14a filter 15 first motor 15a screw 16 photo interrupter 18 second motor 18a ball screw 18b frame 19 photo interrupter 21 guide shaft 22 rotation stop shaft 23 cam plate 30 optical finder 31 first finder lens 31c follower pin 32 first 2 finder lens 32 c follower pin 33 prism 80 electronic camera 81 shooting optical system 82 imaging device 83 battery 84 optical finder 85 flash unit 86 printer 87 DC / DC converter 88 Printer roll paper 89 Printer motor

Claims (6)

[Claims] An imaging optical system configured to form a subject image, comprising: a first lens group and a second lens group; an imaging unit configured to capture an object image via the imaging optical system; A first driving unit for driving the lens group back and forth; a second driving unit for driving the second lens group back and forth; and an optical finder for forming a field image, wherein the photographing optical system and the optical finder Wherein the first driving means and the second driving means are respectively arranged in two spaces formed in a direction intersecting the arrangement. 2. The camera having the optical unit according to claim 1, wherein an intermediate space surrounded by the photographing optical system, the finder optical system, the first driving unit, and the second driving unit includes:
A camera having an optical unit, wherein a guide shaft shared by the first lens group and the second lens group is arranged. 3. The camera having the optical unit according to claim 1, wherein a first sensor for detecting a lens position of the first lens group, and a lens position of the second lens group are detected. A first sensor (or the second sensor) is arranged in a space formed along the optical axis direction of the lens from the position of the first drive means, and a second sensor for performing the second drive. A camera having an optical unit, wherein the second sensor (or the first sensor) is arranged in a space formed from the position of the means along the lens optical axis direction. 4. A camera having the optical unit according to claim 1, wherein the first driving unit and the second driving unit are controlled to zoom the photographing optical system. Zoom control means for varying the amount; focus control means for controlling the first drive means to vary the focal position of the photographing optical system; and driving force of the second drive means for the second lens group. A camera having an optical unit, comprising: an interlocking mechanism that transmits the movement of the lens to the optical finder through movement and zooms a lens of the optical finder. 5. The camera having an optical unit according to claim 4, wherein the first driving unit has a finer control resolution than the second driving unit. 6. A camera having the optical unit according to claim 4 or 5, wherein the second driving means has a higher thrust and a longer stroke than the first driving means. With a camera.