1. Field of the Invention
The present invention relates to a retractable lens camera.
2. Description of the Related Art
With lens-non-detachable cameras, various types of retractable lens cameras are known which have a function of retracting a lens barrel within the camera body thereof, thereby reducing the size thereof in the non-photographing state (see Japanese Laid-open Patent Publication No. H9-203842).
The aforementioned cameras have a configuration which allows the lens groups to move within the lens barrel along the optical axis, thereby retracting the lens barrel within the camera body. Such a camera has a limitation in which the thickness thereof cannot be smaller than the sum of the total thickness of the lenses and the clearances in the lens-barrel retracted state.
According to the 1st aspect of the invention, a retractable lens camera comprises: a lens barrel; three or more lens groups provided in the lens barrel; a retracting unit that retracts the lens barrel and the lens groups into a camera body; and a displacing unit that displaces at least two lens groups to an escaping space out of an optical axis.
According to the 2nd aspect of the invention, in the retractable lens camera according to the 1st aspect, it is preferred that the displacing unit displaces the at least two lens groups to the escaping space in an identical direction.
According to the 3rd aspect of the invention, in the retractable lens camera according to the 1st or 2nd aspect, it is preferred that the retracting unit moves the at least two lens groups in the escaping space toward a rear of the camera.
According to the 4th aspect of the invention, in the retractable lens camera according to any one of the 1st through 3rd aspects, it is preferred that the escaping space is formed by disposing a photographing optical system, which includes the three or more lens groups, with an eccentric design in the lens barrel.
According to the 5th aspect of the invention, in the retractable lens camera according to any one of the 1st through 4th aspects, it is preferred that the at least two lens groups are disposed in a direction of an optical axis within the escaping space.
According to the 6th aspect of the invention, in the retractable lens camera according to any one of the 1st through 5th aspects, it is preferred that the lens barrel comprises a turn cylinder; and the retracting unit retracts the lens barrel and the lens groups into the camera body in association with turning of the turn cylinder.
According to the 7th aspect of the invention, in the retractable lens camera according to the 6th aspect, it is preferred that the retracting unit includes: a holding member provided to a shaft relatively stationary as to turning of the turn cylinder so as to be swung around the shaft, with an end thereof across the shaft holding a lens group of the at least two lens groups, and with the other end having a protrusion; and a guide groove which is formed on an inner face of the turn cylinder for engagement with the protrusion, and which allows the protrusion to move by turning of the turn cylinder, thereby displacing the lens group held by the holding member from the optical axis to the escaping space.
According to the 8th aspect of the invention, in the retractable lens camera according to any one of the 1st through 7th aspects, it is preferred that the at least two lens groups includes a zoom lens group and a focus lens group.
According to the 9th aspect of the invention, in the retractable lens camera according to the 8th aspect, it is preferred that: the focus lens group includes a rack which contacts and is engaged with a focus driving lead screw; and the displacing unit swings the focus lens group to release the rack from being engaged with the focus driving lead screw and displace the focus lens group to the escaping space.
The retracting unit and the displacing unit can replaced with retracting means and displacing means respectively.
Description will be made below regarding the embodiment of the present invention with reference to the drawings.
In
The lens barrel 2 includes a fixed cylinder 21 fixed to the base 3, a cam cylinder 22, a linear-action cylinder 23, and a first-group cylinder 24, each of which is mounted so as to allow movement thereof as to the fixed cylinder 21 along the optical axis. The fixed cylinder 21 is fixed on the base 3 with unshown screws. A helicoidal internal thread 210 is formed on the inner face of the fixed cylinder 21 for being screwed to a helicoidal external thread 220 formed on the outer face of the cam cylinder 22. Upon turning the cam cylinder 22 as to the fixed cylinder 21 by actions of an unshown motor, the cam cylinder 22 is moved along the optical axis within the fixed cylinder 21.
The linear-action cylinder 23 is mounted so as to be inserted into the cam cylinder 22, and is turnably connected to the cam cylinder 22 at the rear end 230 thereof. Note that an unshown protrusion is formed at the rear end 230 of the linear-action cylinder 23 to protrude along the diameter direction. The protrusion is engaged with a straight groove (not shown) formed on the inner face of the fixed cylinder 21. This engagement allows the action of the liner-action cylinder 23 as follows. That is to say, upon turning the cam cylinder 22, the linear-action cylinder 23 is moved straight along with the cam cylinder 22 integrally along the optical axis without rotation of the linear-action cylinder 23.
The linear-action cylinder 23 includes second-group lenses 25 and third-group lenses 26 therewithin. The third-group lenses 26 are held by a holding frame 28 fixed to the linear-action cylinder 23, which allows the third-group lenses to integrally move along with the linear-action cylinder 23 along the optical axis. Furthermore, a shutter unit 29 is fixed to the holding frame 28. A holding frame 27 for holding the second-group lenses 25 is mounted to a guide shaft 231 provided to the linear-action cylinder 23 so as to allow sliding thereof along the optical direction. Furthermore, the holding frame 27 is mounted so as to allow swinging motion thereof with the guide shaft 231 as an axis.
A torsion compression spring 232 provided to the guide shaft 231 presses the holding frame 27 in the forward direction of the camera (in the left direction in the drawing) by compression force. At the same time, the torsion force of the torsion compression spring 232 presses an engaging portion 270 formed on the holding frame 27 to contact with a guide shaft 233. Furthermore, a follower pin 271 is formed on the outer face of the holding frame 27. The tip of the follower pin 271 is engaged with a cam groove 221 formed on the inner face of the cam cylinder 22. With such a configuration, upon turning the cam cylinder 22, the holding frame 27 is moved along the optical axis within the cam cylinder 22.
The first-group cylinder 24 holding the first-group lenses 30 is mounted so as to be inserted into the cam cylinder 22. Furthermore, a follower pin 240 formed on the outer face of the first-group cylinder 24 is engaged with a cam groove 222 formed on the inner face of the cam cylinder 22. Furthermore, a protrusion 241 formed on the inner face of the first-group cylinder 24 is engaged with a guide groove 234 formed on the linear-action cylinder 23. With such a configuration, upon turning the cam cylinder 22, the first-group cylinder 24 is moved within the cam cylinder 22 along the optical axis. Reference numeral 31 denotes a fourth-group lens held by a holding frame 32. The holding frame 32 is slidably mounted to a guide shaft 33 provided on the base 3. Furthermore, the holding frame 32 is mounted so as to allow swinging motion thereof with the guide shaft 33 as an axis.
A torsion compression spring 330 provided to the guide shaft 33 presses the holding frame 32 in the forward direction of the camera (in the left direction in the drawing) by compression force. At the same time, the torsion force thereof presses a rack 320 formed on the holding frame 32 to contact with a lead screw 321.
At the time of switching from the wide-angle state shown in
In any photographing state between the wide-angle state shown in
Next, description will be made regarding the configuration of the second-group lens system, the configuration of the fourth-group lens system, and the displacing action.
[Regarding the Actions of the Second-Group Lens System]
In the drawing, represented by the solid line is the holding frame 27 positioned in the photographing state as shown in either
In the wide-angle state shown in
Upon turning the cam cylinder 22 as represented by the arrows R1, R2, and R3, in that order, as shown in
Upon further turning the cam cylinder 22 after the turn R1, the follower pin 271 tilts within the cam groove 221 as shown in
As a result, as shown in
With such a configuration as well, the follower pin 271 is pressed into contact with the inner face of the cam cylinder 22 by actions of the torsion compression spring 232, thereby preventing the holding frame 27 from turning as to the linear-action cylinder 23. Accordingly, such a configuration allows the same path of the follower pin 271 as that shown in
[Regarding the Actions of the Fourth-Group Lens System]
With such a configuration, the cam 235 and the linear-action cylinder 23 are moved integrally. Note that a slope 235a and a pressing face 235b are formed at the tip of the cam 235. In the state shown in
Then, upon the cam 235 further moving backward as shown in
Upon cam 235 further moving backward, the holding frame 32 is moved upward to the position of the pressing face 235b. In this state, the camera completely enters the lens-barrel retracted state as shown in
In the embodiment, the second-group lenses 25 and the fourth-group lens 31 are displaced or moved out in the same direction perpendicular to the optical axis of the lens barrel 2, and displaced or moved out into the same escaping space. By this means, the size of the lens barrel and the size of the retractable lens camera in the diameter direction of lens are reduced.
With the present embodiment as described above, the optical axis J of the photographing optical system is designed to be positioned downward from the center axis J2 of the lens barrel 2 so as to form the escaping space S above the optical axis J as shown in
However, the present invention is not restricted to such an arrangement, rather, an arrangement may be made in which the second-group lenses 25 and the fourth-group lens 31 are swung somewhat less such that the second-group lenses 25 and the fourth-group lens 31, thus displaced, overlap with the first-group lenses 30 and the third-group lenses 26 in the lens-barrel retracted state. Even with such a configuration, the camera has the advantage of reducing the thickness thereof in the lens-barrel retracted state since the lens group is somewhat shifted from the optical axis. Furthermore, an arrangement may be made in which the lens-barrel center axis J2 matches the optical axis J, and the swinging of the second-group lenses 25 and the fourth-group lens 31 is designed according to such a layout.
With the present embodiment described above, the second-group lenses 25 and the fourth-group lens 31 are turned in the same direction so as to be disposed in a line in the thickness direction. Also, an arrangement may be made in which the second-group lenses 25 and the fourth-group lens 31 are turned in opposite directions with the optical axis J as the center. With such a configuration, the second-group lenses 25 and the fourth-group lens 31 are not disposed serially in the thickness direction, but can be disposed opposite one to another across the optical axis at generally the same position in the optical-axis direction, in the lens-barrel retracted state. Such a configuration allows more reduction of the overall thickness of the camera in the lens-barrel retracted state. While description has been made regarding an arrangement in which two of the four lens groups are displaced away from the optical axis, an arrangement may be made in which three of the four lens groups are displaced away. Furthermore, the present invention is not restricted to an arrangement including the four lens groups, rather, the present invention may be applied to an arrangement including three, five, or more lens groups.
The above described embodiments are examples, and various modifications can be made without departing from the spirit and scope of the invention.
Number | Date | Country | Kind |
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2004-255696 | Sep 2004 | JP | national |
This application is a continuation of U.S. application Ser. No. 11/216,472, filed Sep. 1, 2005, and now abandoned, which further claims the benefit of priority of Japanese Patent Application No. Japanese Patent Application No. 2004-255696 filed Sep. 2, 2004, the contents of which are incorporated herein by reference.
Number | Name | Date | Kind |
---|---|---|---|
4451129 | Ikari et al. | May 1984 | A |
4597657 | Wakabayashi et al. | Jul 1986 | A |
4669848 | Wakabayashi et al. | Jun 1987 | A |
4841323 | Yamada et al. | Jun 1989 | A |
4857947 | Wakabayashi et al. | Aug 1989 | A |
4887107 | Nakamura et al. | Dec 1989 | A |
5099263 | Matsumoto et al. | Mar 1992 | A |
6978088 | Nomura | Dec 2005 | B2 |
6978089 | Nomura et al. | Dec 2005 | B2 |
7035019 | Sakamoto | Apr 2006 | B2 |
7301577 | Sakamoto | Nov 2007 | B2 |
7317487 | Omiya et al. | Jan 2008 | B2 |
7632024 | Huang | Dec 2009 | B2 |
20030156832 | Nomura et al. | Aug 2003 | A1 |
20040228626 | Endo et al. | Nov 2004 | A1 |
20050036777 | Nomura et al. | Feb 2005 | A1 |
20050185297 | Omiya et al. | Aug 2005 | A1 |
Number | Date | Country |
---|---|---|
63-034524 | Feb 1988 | JP |
08-211483 | Aug 1996 | JP |
08-234089 | Sep 1996 | JP |
09-203842 | Aug 1997 | JP |
2001-344381 | Dec 2001 | JP |
2003-149723 | May 2003 | JP |
2003-315861 | Nov 2003 | JP |
2004-118022 | Apr 2004 | JP |
2005-284247 | Oct 2005 | JP |
Number | Date | Country | |
---|---|---|---|
20080310035 A1 | Dec 2008 | US |
Number | Date | Country | |
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Parent | 11216472 | Sep 2005 | US |
Child | 12222450 | US |