JP4078705B2 - Camera with optical unit - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a camera having an optical unit in which a photographing optical system and an optical viewfinder are combined. In particular, the present invention relates to a technique for saving the entire space by arranging a lens driving mechanism of a photographing optical system in combination with a photographing optical system and an optical finder.
[0002]
[Prior art]
Conventionally, Japanese Patent Laid-Open No. 9-163196 discloses an example of an internal layout of an electronic camera. FIG. 6 is a diagram for explaining the internal layout.
In FIG. 6, a photographing optical system 81 is arranged on the left side from the front of the electronic camera 80. An image sensor 82 is disposed on the optical axis of the photographing optical system 81. A battery 83 is disposed at the back of the photographing optical system 81 in the longitudinal direction.
[0003]
In addition, a long optical viewfinder 84 is disposed adjacent to the photographing optical system 81 and the battery 83.
A flash unit 85 is disposed on the right side of the objective side lens of the optical viewfinder 84. Behind the flash unit 85, a printer 86 and a DC / DC converter 87 are arranged in a substantially line. A printer roll paper 88 and a printer motor 89 are arranged in a space surrounded by a U shape by the flash unit 85, the printer 86 and the DC / DC converter 87.
With the above layout configuration without waste, the entire electronic camera 80 can be reduced in size, and the portability and operability of the electronic camera 80 can be further improved.
[0004]
[Problems to be solved by the invention]
Incidentally, when an autofocus function or a power zoom function is added to the above-described photographing optical system 81, a focus control motor, a zoom drive motor, or the like needs to be newly provided. In this case, there arises a problem that the outer shape of the electronic camera is increased by the amount of installation space for the motor group.
[0005]
In addition, when these motor groups are arranged near the photographing optical system 81, it is difficult to arrange the photographing optical system 81 and the optical finder 84 close to each other. As a result, the distance between the optical axes of the photographing optical system 81 and the optical finder 84 is increased, and the parallax of the optical finder 84 is increased.
Accordingly, in order to solve these problems, it is an object of the present invention to provide a camera in which a motor and the like are arranged in an optical unit composed of a photographing optical system and an optical viewfinder in a space efficient manner.
[0006]
Further, in the invention according to claim 1, in addition to the purposes described above, the guide axis of the photographing optical system in said optical unit arranged well space efficient, and be kept low rattling when the lens is driven An object is to provide a possible camera.
Furthermore, an object of the present invention is to provide a camera in which an interlocking mechanism between a photographing optical system and an optical finder is provided in the optical unit in a space efficient manner in addition to the above-described object.
According to a second aspect of the present invention, in addition to the object of the first aspect, a camera capable of spatially efficiently arranging a lens position detection sensor in the optical unit and increasing the detection accuracy of the lens position. The purpose is to provide.
[0007]
In the invention described in 請 Motomeko 3, in addition to the purpose of claim 1, in order to improve the focusing accuracy, and to provide a optimized a camera performance balance of the photographing optical system drive means .
The invention according to claim 4, in addition to the purpose of claim 1, in order to improve the zoom performance, and an object thereof is to provide a optimized the camera performance balance driving means of the photographic optical system.
[0008]
[Means for Solving the Problems]
(Claim 1)
The invention according to claim 1 is composed of at least a first lens group and a second lens group, an imaging optical system that forms an object image, and an imaging unit that images the object image via the imaging optical system; First driving means for driving the first lens group back and forth, second driving means for driving the second lens group back and forth, an optical viewfinder for forming a field image , first driving means and second driving means The zoom control means for changing the zoom amount of the photographing optical system, the focus control means for changing the focal position of the photographing optical system by controlling the first drive means, and the driving force of the second drive means, A cam interlocking mechanism that transmits to the optical viewfinder side through the movement of the second lens group and zooms the lens of the optical viewfinder, and the photographing optical system and the optical viewfinder are arranged side by side, and the direction intersects with the arrangement Two spaces formed in The first driving means and the second driving means are arranged, respectively, and the first lens group and the second lens are disposed in an intermediate space surrounded by the photographing optical system, the finder optical system, the first driving means, and the second driving means. A guide shaft shared by the group is arranged , and the cam is linked between the optical viewfinder and the first driving means and the second driving means so as to extend along the driving direction of the first lens group and the second lens group. In addition to the arrangement of the mechanism, the photographing optical system, the second driving means, and the optical viewfinder are arranged radially adjacent to each other with the cam interlocking mechanism interposed therebetween .
[0009]
In general, since the photographing optical system has a round shape such as a cylindrical shape, when the photographing optical system and the optical viewfinder are arranged, two empty spaces are formed 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 optical unit can be reduced in size.
In addition , 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.
[0011]
In general, an empty space is generated in an intermediate portion surrounded by the photographing optical system, the optical finder, the first driving means, and the second driving means. By arranging a long guide shaft so as to be partially inserted into the intermediate space, the optical unit can be miniaturized.
Further, by arranging the guide shaft in the intermediate space in this way, the guide shaft and the first driving means are arranged close to each other. Therefore, the distance between the “force application position 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, deflection deformation, dynamic friction force, and the like generated in the first lens group are reduced, and rattling and the like associated with the sliding movement of the first lens group can be suppressed to a low level. For the same reason, rattling and the like associated with the slide movement can be kept small for the second lens group.
In such a configuration, the driving force of the second driving means is transmitted to the optical viewfinder side via the second lens group. Therefore, it is not necessary to separately provide a detour path for transmitting the driving force from the second driving means to the optical viewfinder, and the optical unit can be reduced in size.
Further, as described above, the photographing optical system, the optical finder, and the second driving unit are arranged in close proximity to each other radially. Therefore, the driving force of the second driving means can be transmitted to the photographing optical system and the optical viewfinder with low loss.
Furthermore, since the second lens group and the optical viewfinder are connected by an interlocking mechanism, it is possible to absorb the natural vibration on the second lens group side to some extent on the optical viewfinder side. Accordingly, the zoom movement of the second lens group can be further smoothed.
In particular, in such a configuration, since the guide shaft is disposed in the intermediate portion between the photographing optical system and the optical viewfinder, the driving force that transmits the interlocking mechanism passes near the guide shaft. At this time, the “extra force other than sliding the second lens group” is once absorbed by the guide shaft, so that the driving force can be efficiently transmitted to the optical viewfinder side.
[0012]
(Claim 2 )
According to a second aspect of the present invention, in the camera having the optical unit according to the first aspect, the first sensor for detecting the lens position of the first lens group and the lens position of the second lens group are detected. The first sensor (or the second sensor) is disposed in a space formed along the lens optical axis direction from the position of the first driving means, and from the position of the second driving means. A second sensor (or the first sensor) is disposed in a space formed along the lens optical axis direction.
[0013]
Usually, the first driving means and the second driving means are shorter in total length than the photographing optical system and the optical viewfinder. Therefore, an empty space is generated from the position of these driving means along the lens optical axis. By disposing the first sensor and the second sensor in this empty space, the optical unit can be reduced in size.
In particular, in the configuration according to claim 1, in proximity to the guide shaft of the intermediate portion, the first and second sensors are arranged. In this case, the first sensor and the second sensor detect the lens position near the guide shaft. Therefore, the detection value of the lens position is unlikely to include errors such as lens group deflection, and the detection accuracy of the first sensor and the second sensor can be further increased.
[0017]
(Claim 3 )
According to a third aspect of the present invention, in the camera having the optical unit according to the first or second aspect , the first drive means has a finer control resolution than the second drive means.
With such a configuration, it is possible to finely position the first lens group via the first driving means. Therefore, the focusing accuracy of the photographic optical system can be further improved.
[0018]
(Claim 4 )
According to a fourth aspect of the invention, in a camera having an optical unit according to claims 1 or one of claims 3, second drive means, is a high thrust and a long stroke than the first driving means It is characterized by that.
In such a configuration, a high thrust can be obtained from the second driving means, so that the second lens group can be moved at a high speed. Therefore, the zoom speed of the photographing optical system can be increased.
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]
DETAILED DESCRIPTION OF THE INVENTION
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, the electronic camera includes a camera body 1 provided with a liquid crystal monitor and the like, and a rotating unit 2 that is rotatably attached to the camera body 1. An optical unit 3 is disposed inside the rotating unit 2.
[0020]
FIG. 2 is an explanatory diagram showing an AA ′ transverse section of the optical unit 3 shown in FIG.
In FIG. 2, the optical unit 3 is schematically constituted by an arrangement of a photographing optical system 10 and an optical viewfinder 30. In the photographing optical system 10, a first lens group 11, a second lens group 12, and a third lens 13 are arranged in order from the objective side.
The zoom magnification (focal length) of the photographing optical system 10 is changed by mainly moving the second lens group 12 and slightly moving the first lens group 11 for correction.
[0021]
Further, the focus adjustment of the photographing optical system 10 is performed by driving the first lens group 11 back and forth as a single unit.
The 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 image sensor 14 are integrally held by a CCD holder 14b.
[0022]
A guide shaft 21 is disposed in the gap between the photographing optical system 10 and the optical viewfinder 30. A rotation stop shaft 22 is disposed in the gap between the casing 3 a 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 first lens group 11 is held around the lens by the first lens chamber 11a. The holding part 11z protrudes from both sides of the first lens chamber 11a. These gripping portions 11z grip the guide shaft 21 and the rotation stop shaft 22, respectively, so that the first lens group 11 is positioned at the center of the photographing optical path.
[0023]
The second lens group 12 is held around by the second lens chamber 12a. Grasping portions 12z protrude from both sides of the second lens chamber 12a. These gripping portions 12z grip 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.
A shutter unit 12b is disposed immediately before the second lens group 12. The shutter unit 12 b is fixed to the second lens chamber 12 a and moves back and forth together with the second lens group 12.
[0024]
Further, the follower pin 12c protrudes from the grip portion 12z of the second lens chamber 12a. This follower pin 12 c 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 follower pins 31c and 32c on the optical finder 30 side are fitted in the remaining two cam grooves of the cam plate 23, respectively. The follower pin 31 c is projected from the first finder lens 31 of the optical finder 30. Further, the follower pin 32 c protrudes from the second finder lens 32 of the optical finder 30.
[0025]
By 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 the field image formed by the optical finder 30 and guides it to the eyepiece window.
[0026]
FIG. 3 is an explanatory diagram showing a BB ′ longitudinal section shown in FIG. 2.
FIG. 4 is an explanatory view showing a longitudinal cross-section CC ′ shown in FIG. 2.
As shown in FIGS. 3 and 4, the first motor 15 and the second motor 18 are arranged in spaces formed in directions intersecting with the arrangement of the photographing optical system 10 and the optical viewfinder 30, respectively. A guide shaft 21 is disposed in an intermediate space surrounded by the photographing optical system 10, the optical viewfinder 30, the first motor 15, and the second motor 18.
[0027]
FIG. 5 is an explanatory view showing a DD ′ longitudinal section shown in FIG. 2.
As shown in FIG. 5, the grip portion 11 z of the first lens chamber 11 a is formed in a U shape and grips the guide shaft 21 at two locations. A screw receiving portion 11d protrudes from the rear side of the grip portion 11z. A screw 15a of the first motor 15 is brought into contact with the screw receiving portion 11d. On the other hand, one end of the spring 17 is fixed to the front side of the grip portion 11z, and an urging force is applied to pull back the first lens chamber 11a.
[0028]
In addition, a photo interrupter 16 is disposed in a front space along the photographing optical axis from the position of the first motor 15. A slit 11e protruding from the gripping portion 11z passes between the photo interrupters 16. The photo interrupter 16 is a position sensor for detecting the origin position of the first lens group 11.
The sliding mechanism of the first lens group 11 described above is
(1) Stroke length: 7mm
(2) Thrust ... 50gf
(3) Control resolution: 1.5 μm
Set to
[0029]
On the other hand, the grip portion 12z of the second lens chamber 12a is formed in an inverted U shape and grips the guide shaft 21 at two locations. The frame 18b is connected to the grip portion 12z via a connecting portion 12d. The top 18b moves back and forth by the rotation of the ball screw 18a of the second motor 18 in two forward and reverse directions.
A photo interrupter 19 is disposed in a front space along the photographing optical axis from the position of the second motor 18. A slit 12e projecting from the grip portion 12z passes between the photo interrupters 19. The photo interrupter 19 is a position sensor for detecting the origin position of the second lens group 12.
[0030]
The slide mechanism of the second lens group 12 described above is
(1) Stroke length: 20mm
(2) Thrust ··· 200gf
(3) Control resolution: 10 μm
Set to
[0031]
(Effects of this embodiment)
With the above-described configuration, in the present embodiment, the first motor 15 and the second motor 18 are respectively disposed in two empty spaces that intersect with the arrangement of the photographing optical system 10 and the optical viewfinder 30. Therefore, the first motor 15 and the second motor 18 can be arranged in a space efficient manner, and the optical unit 3 can be downsized.
[0032]
In the present embodiment, the guide shaft 21 is disposed in an intermediate space surrounded by the photographing optical system 10, the optical viewfinder 30, the first motor 15, and the second motor 18. Therefore, it is possible to arrange the guide shaft 21 in a space efficient manner and reduce the size of the optical unit 3.
Furthermore, with 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. Therefore, the influence of the reaction force generated between them is reduced, and the deflection, dynamic friction force, and the like generated in the first lens chamber 11a can be suppressed to a low level. Accordingly, the first lens group 11 can be smoothly slid.
[0033]
In addition, due to the central arrangement of the guide shaft 21 described above, the “action point of the force of the second motor 18” and the “guide shaft 21” are close to each other. Therefore, the influence of the reaction force generated between them can be reduced, and the deflection and dynamic friction force generated in the second lens chamber 12a can be kept small. Therefore, the second lens group 12 can be smoothly slid.
[0034]
Further, in the present embodiment, the photo interrupter 16 and the photo interrupter 19 are arranged in the front space of the first motor 15 and the second motor 18, respectively. Therefore, the photo interrupters 16 and 19 can be arranged in a space efficient manner, and the optical unit 3 can be downsized.
In particular, the arrangement of the photo interrupters 16 and 19 enables the photo interrupters 16 and 19 and the guide shaft 21 to be arranged close to each other. Therefore, at the position of the photo interrupters 16 and 19, it becomes difficult to be affected by the deflection of the lens group, and the detection accuracy of the photo interrupters 16 and 19 can be improved.
[0035]
In the present embodiment, the driving force of the second motor 18 is transmitted to the optical viewfinder 30 side via the follower pin 12c of the second lens chamber 12a. Therefore, it is not necessary to separately provide a detour path for transmitting the driving force to the optical viewfinder 30, and the optical unit 3 can be reduced in size.
Further, the second motor 18, the second lens chamber 12 a, and the optical viewfinder 30 are arranged radially around the guide shaft 21. Therefore, the driving force of the second motor 18 can be stably transmitted to the second lens group 12 and the optical viewfinder 30 with low loss.
[0036]
Further, in the present embodiment, the control resolution on the first motor 15 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.
In the present embodiment, the thrust on the second motor 18 side is set larger than the thrust on the first motor 15 side. Accordingly, the zoom movement of the second lens group 12 can be speeded up, and the zoom movement of the photographing optical system 10 can be completed in a short time.
[0037]
Further, in the present embodiment, the stroke on the second motor 18 side is set longer than the stroke on the first motor 15 side. Therefore, the moving distance of the second lens group 12 is increased, and the zoom magnification of the photographing optical system 10 can be further increased.
In the above-described embodiment, the image sensor 14 is arranged to configure the electronic camera, but the present invention is not limited to this configuration. For example, a silver salt camera may be configured by arranging a film feeding mechanism or the like as an imaging unit.
In the above-described embodiment, the photographing optical system 10 having a three-group lens configuration has been described. However, the present invention is not limited to this configuration. In general, the present invention can be applied to any imaging optical system having a lens configuration of N groups (N ≧ 2).
[0038]
【The invention's effect】
(Claim 1)
According to the first aspect of the present invention, the photographing optical system and the optical viewfinder are arranged side by side, and the first driving means and the second driving means are respectively arranged in two spaces formed in directions intersecting with the arrangement. . Therefore, the first driving means and the second driving means can be arranged in a space efficient manner, and the optical unit can be downsized.
In addition, 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 is not separated, and the parallax of the optical finder can be suppressed to be small. .
[0039]
In the first aspect of the present invention, the guide shaft is disposed in an intermediate space that is surrounded by the photographing optical system, the finder optical system, the first driving means, and the second driving means. Therefore, the guide shaft can be arranged in a space efficient manner, and the optical unit can be downsized.
[0040]
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 friction force to be low and to suppress the rattling associated with the sliding movement of the first lens group.
Furthermore, since the distance between the guide shaft and the second driving means is short, it is possible to suppress deflection and dynamic frictional force, and to suppress rattling associated with the sliding movement of the second lens group.
According to the first aspect of the present invention, the driving force of the second driving means is transmitted to the optical viewfinder side via the second lens group. Therefore, it is not necessary to separately provide a detour path for transmitting the driving force to the optical finder, and the optical unit can be reduced in size.
In addition, since the photographing optical system, the optical finder, and the second driving means are arranged close to each other in the radial direction, 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.
[0041]
(Claim 2 )
In the second aspect of the invention, the first sensor and the second sensor are arranged in an empty space generated along the lens optical axes of the first driving means and the second driving means. Therefore, the first sensor and the second sensor can be arranged in a space efficient manner, and the optical unit can be downsized.
In particular, in the configuration as in claim 1 , the guide shaft is disposed near the first sensor and the second sensor. Therefore, the position of the first sensor and the second sensor is not easily affected by the deflection of the lens group outer frame, and the detection accuracy of the lens position can be further improved.
[0043]
(Claim 3 )
In the third aspect of the invention, since the first driving unit can finely position the first lens group, it is possible to improve the focusing accuracy of the photographing optical system.
[0044]
(Claim 4 )
In the fourth aspect of the invention, since the second lens group moves at a high speed due to the high thrust from the second driving means, the zoom speed of the photographing optical system can be increased.
Further, since the second driving unit 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 ′ shown in FIG. 1;
FIG. 3 is an explanatory view showing a BB ′ longitudinal section shown in FIG. 2;
FIG. 4 is an explanatory diagram showing a CC ′ vertical cross section shown in FIG. 2;
FIG. 5 is an explanatory view showing a DD ′ longitudinal section shown in FIG. 2;
6 is a diagram showing an internal layout of a conventional electronic camera 80. FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Camera body 2 Rotating part 3 Optical unit 10 Image pick-up optical system 11 1st lens group 11a 1st lens chamber 11d Screw receiving part 11e Slit 12 2nd lens group 12a 2nd lens chamber 12b Shutter unit 12c Follower pin 12d Connecting part 13 1st 3 lens 14 imaging device 14a filter 15 first motor 15a screw 16 photo interrupter 18 second motor 18a ball screw 18b top 19 photo interrupter 21 guide shaft 22 rotation stop shaft 23 cam plate 30 optical viewfinder 31 first viewfinder lens 31c follower pin 32 first 2 finder lens 32c follower pin 33 prism 80 electronic camera 81 photographing optical system 82 image sensor 83 battery 84 optical finder 85 flash unit 86 printer 87 DC / DC converter 88 printing Motor for use roll paper 89 printer

Claims (4)

A photographic optical system that includes at least a first lens group and a second lens group, forms a subject image, an imaging unit that captures a subject image via the photographic optical system, and the first lens group in the front-rear direction. Controlling a first driving means for driving, a second driving means for driving the second lens group back and forth, an optical viewfinder for forming a field image , the first driving means and the second driving means; The zoom control means for changing the zoom amount of the photographing optical system, the focus control means for controlling the first driving means to change the focal position of the photographing optical system, and the driving force of the second driving means, A cam interlocking mechanism that transmits to the optical finder side through the movement of the second lens group and zooms the lens of the optical finder, and the photographing optical system and the optical finder are arranged side by side, Intersect The first driving means and the second driving means are respectively disposed in two spaces formed in the direction, and the photographing optical system, the finder optical system, the first driving means, and the second driving means are provided. A guide shaft shared by the first lens group and the second lens group is disposed in the enclosed intermediate space, and the first driving means and the second driving means are disposed between the optical viewfinder and the first driving means and the second driving means. The cam interlocking mechanism is disposed so as to extend along the driving direction of one lens group and the second lens group, and the photographing optical system, the second driving means, and the optical finder include the cam interlocking mechanism. A camera having an optical unit, wherein the cameras are arranged close together in a radial pattern . The camera having the optical unit according to claim 1, further comprising: a first sensor for detecting a lens position of the first lens group; and a second sensor for detecting a lens position of the second lens group. Then, the first sensor (or the second sensor) is arranged in a space formed along the lens optical axis direction from the position of the first driving means, and the lens optical axis direction from the position of the second driving means. A camera having an optical unit, wherein the second sensor (or the first sensor) is arranged in a space formed along the line. 3. A camera having an optical unit according to claim 1 , wherein the first drive means has a finer control resolution than the second drive means. A camera having an optical unit according to claims 1 to any one of claims 3, an optical unit and the second driving means, wherein said a high thrust and a long stroke than the first driving means Having a camera.

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