This application is based upon and claims the benefit of priority from prior Japanese Patent Application No. 2006-015613, filed on Jan. 24, 2006, the entire contents of which are incorporated herein by reference.
1. Field of the Invention
The present invention relates to the arrangement and structure of a camera incorporating a lens frame therein.
2. Description of the Related Art
There has been a recent demand for smaller devices with shooting capability such as a camera. For example, a camera disclosed in Japanese Patent Application Laid-Open No. 2005-257784 employs a reflecting optical system for bending the optical axis of an incident light flux as a photographing optical system in a lens frame to make the device thinner. Then, in order to prevent adverse effects of the external loads placed on the lens frame, lens frame holding means is employed to hold the lens frame between two surfaces substantially parallel with each other.
Further, Japanese Patent Application Laid-Open No. 2002-341401 discloses a barrier device for a lens frame, which integrates a barrier opening/closing mechanism with the lens frame having a reflecting member for reflecting and bending an incident light flux.
The camera of the present invention includes a lens frame in which an optical system including a reflecting optical member is housed, a lens frame mounting part arranged on one side of the lens frame, a fixing member in which the lens frame is mounted through the lens frame mounting part in a direct or indirect manner, and one or more drive sources for driving movable portions of the camera. In the camera of the present invention, at least one of the drive sources is arranged on the side of the lens frame mounting part with respect to an optical axis plane formed by optical axes before and after reflected by the reflecting optical member.
An exemplary structure of the camera of the present invention is as follows: A camera comprises a lens frame having a reflecting optical member for reflecting light from a subject incoming along a first optical axis toward a second optical axis intersecting the first optical axis, a fixing member mounting the lens frame therein, a lens frame mounting part arranged on one side of the lens frame with respect to an optical axis plane defined by the first optical axis and the second optical axis, and a plurality of drive sources arranged in the lens frame to drive movable portions in the lens frame, wherein at least one of the plurality of drive sources is arranged on the side of the lens frame mounting part with respect to the optical axis plane.
Another exemplary structure of the camera of the present invention is as follows: A camera comprises a lens frame having a reflecting optical member for reflecting light from a subject incoming along a first optical axis toward a second optical axis intersecting the first optical axis, a fixing member having an opening for guiding the subject light to the lens frame along the first optical axis and mounting the lens frame therein, a lens barrier mounted in the fixing member in such a manner to be movable between a position to open the opening and a position to shut the opening, a lens frame mounting part arranged on one side of the lens frame with respect to an optical axis plane defined by the first optical axis and the second optical axis, a drive source arranged in the lens frame to drive a movable lens in the lens frame, and a drive member arranged in the lens frame to drive the lens barrier, wherein the drive member is arranged on the side of the lens frame mounting part with respect to the optical axis plane.
These and other features, aspects, and advantages of the apparatus and methods of the present invention will become better understood with regard to the following description, appended claims, and accompanying drawings where:
Preferred embodiments of the invention are described below with reference to the accompanying drawings.
In the following description, the right-and-left direction of the camera is expressed as an X direction, the up-and-down direction orthogonal to the X direction (a direction parallel to an optical axis O2 orthogonal to an optical axis O1 to be described later) is expressed as a Y direction, and the front-and-rear direction orthogonal to the X and Y directions is expressed as a Z direction. The Z direction is a direction parallel to the optical axis O1 (that is, the thickness direction of the camera). Further, the subject side of the camera in the Z direction is expressed as a front side, while the photographer side is expressed as a rear side (or backside). The right and left in the X direction are defined when viewed from the backside of the camera. Further, a plane containing both the optical axis O1 and the optical axis O2 in common is expressed as an optical axis plane. The optical axis plane is a plane parallel to a YZ plane.
As shown in
As shown in
The lens frame unit 4 is supported through the lens frame body 17 by lens frame mounting parts 410 and 420 arranged at two points on the left side of the optical axis plane inside the front cover 2. The lens frame mounting parts 410 and 420 are located at the two points, one being above the shutter actuator 37 and the other being below the focus actuator 35/focus unit 36, to support the lens frame unit 4 in such a manner that the lens frame unit 4 can minutely displace in the Z direction in order to absorb impact forces. Thus, the lens frame mounting parts 410 and 420 are arranged on one side of the lens frame unit 4 with respect to the optical axis plane while being separated from each other in the direction of the optical axis O2.
The reflecting optical system unit 31 is assembled in the frame 13 for the reflecting optical system and arranged behind a shooting window part 12 provided as an opening 2a (
As shown in
As shown in
As shown in
The focus actuator 35, arranged under the shutter actuator 37, is an actuator for driving the fourth group frame 24 holding the fourth group lens 25 through the focus unit 36 to advance or retract to perform focusing.
The focus unit 36 is a mechanical part to drive the fourth group frame 24 to advance or retract to perform focusing, and consists of a guide shaft, a threaded lead shaft, etc. arranged along the Y direction in the vicinity of the focus actuator 35.
The zoom actuator 33, arranged in a right end portion of the lens frame body 17 in such a manner to project from the lens frame body 17, is an actuator for driving the second and third frames 18 and 22 through the zoom unit 34 to advance or retract to perform zooming and further driving the barrier connecting part 38 to rotate.
The zoom unit 34 is a mechanical part to drive the second and third frames 18 and 22 to perform zooming, and consists of a guide shaft, a rotation drive shaft, a zoom cam, etc. arranged along the Y direction in the vicinity of the zoom actuator 33.
As shown in
As shown in
In each of the mounting/supporting portions 17a and 17e of the lens frame body 17, a hole section is formed in the Z direction. The hole section is made up of a fitting hole 17c into which each of the fixed pins 41 and 42 fits tightly without leaving any gap therebetween, rubber insert holes 17b provided at both the front and rear of the hole section in a shaft direction (Z direction), a tapered portions 17d provided between the rubber insert holes 17b and the fitting hole 17c, respectively. The fitting hole 17c is formed to be extended from the inner periphery of the hole section so that the width of the fitting hole portion will be reduced through the tapered portion 17d in the shaft direction. Note that the portion of the fitting hole 17c to come in contact with each of the fixed pins 41 and 42 can be formed into a shape having a microarc-like cross section so that each of the fixed pins 41 and 42 will be fitted in linear contact with the fitting portion of the fitting hole 17c.
Each of the rubber bushes 43 and 44 has an outside diameter portion to be deformed and inserted (press-fitted) into the rubber insert hole 17b and an inclined portion that comes into contact with the tapered portion 17d.
One end of each of the fixed pins 41 and 42 is formed into a spheroidal or chamfered edge, with a flange 41c or 42c and a pin portion 41a or 42a formed at the other end.
In the front cover 2, as shown in
When the lens frame unit 4 is mounted in the front cover 2 through the lens frame mounting parts, the rubber bushes 43, 44 and 45, 46 are mounted into the rubber insert holes 17b of the lens frame body 17, for example, as shown in
The lens frame unit 4 in which the fixed pins 41 and 42 and the rubber bushes are mounted is then set into a lens frame mounting portion of the front cover 2 as shown in
After mounting of the fixed pins 41 and 42, the fixed pins 41 and 42 are held down by presser plates 51 and 52 made of a metal plate, respectively. Then, presser plates 53 and 54 made of a metal plate, respectively, are attached to the front cover 2 from the backside of the lens frame body 17. To be more specific, the presser plates 51 and 52 are positioned by positioning pins 2e, 2f, and 2h on the front cover 2 side, and under this condition, screws are inserted into insert holes 51a and 52a and tightened into screw holes 2d and 2g on the lens frame body 17 side. At this time, pin holes 51d and 52d of the presser plates 51 and 52 are inserted on the rear end pin portions 41a and 42a of the fixed pins 41 and 42, respectively, to hold down the flanges 41c and 42c forward, pressing the front and rear projecting portions of the rubber bushes 43, 44 and 45, 46 to deform by a predetermined amount. Thus, the rearward movement of the lens frame unit 4 in a position separated from the lens frame mounting parts is restricted by the presser plates 53 and 54. In this condition, the lens frame unit 4 is being urged rearward with respect to the front cover 2 by means of a cushioning material 55 to be described later.
On the other hand, the presser plates 53 and 54 are positioned by positioning pin 2k, 2j and 2n, 2p on the front cover 2 side, and under this condition, screws are inserted into insert holes 53a and 54a and tightened into screw holes 2i and 2m on the front cover 2 to fix the presser plates 53 and 54, respectively.
In the above-mentioned mounted condition, the mounting/supporting portions 17a and 17e of the lens frame body 17 are sandwiched between the front cover 2 on the front side and the flanges 41c and 42c pressed by the presser plates 51 and 52 on the rear side in the Z direction through the interposition of the front and rear projecting portions of the rubber bushes 43, 44 and 45, 46.
The presser plates 53 and 54 are held on the backside of the lens frame body 17. Therefore, when an impact is applied to the lens frame body 17 to make the lens frame body 17 displace or tilt relative to the impact force, the displacement is restricted by the presser plates 53 and 54. On the other hand, the front side of the lens frame body 17 is kept separated a predetermined distance from the front cover 2 except the portions of the rubber bushes 44 and 46, and the low cushioning material 55 (
When an impact force having a Z directional component is exerted on the camera 1 to which the above-mentioned lens frame mounting parts are applied, the lens frame body 17 displaces with respect to the front cover 2 by a minute amount due to elastic deformation of the rubber bushes 43, 44 and 45, 46, thereby absorbing the impact force. As for components in the X direction (specifically, the direction orthogonal to the optical axis plane containing the optical axis O1 and the optical axis O2) or in the Y direction (specifically, the direction parallel to the optical axis O2), since the lens frame body 17 is supported and restricted not to move by the fixed pins 41 and 42, the position of the lens frame unit 4 on the XY plane is held. In addition, as for rotation components around the X or Y axis and the Z axis, and further around axes tilted with respect to the respective axes, the thickness of the rubber bushes 43, 44 and 45, 46 in the radial direction vary respectively, thereby absorbing the impact force due to the rotation. As mentioned above, since the fitting length of the fixed pins 41, 42 and the respective fitting hole portions 17c is set short, the movement of the lens frame unit 4 in the rotation direction is also allowed, so that impact resistance can be increased.
If a slight clearance is formed between the fixed pins 41, 42 and the respective fitting hole portions 17c, the movement of the lens frame unit 4 in the X and Y directions is also allowed, so that impact resistance can further be increased.
As shown in
The following describes the barrier connecting part 38 and the barrier driving transmission unit 71 for driving the opening and closing of the lens barrier 77 with reference to FIGS. 7 to 12. The barrier connecting part 38 is driven through a gear by the rotation drive shaft of the zoom unit 34 to drive the driving transmission unit 71 to open or close the lens barrier 77.
As shown in
The lower cam 62 has a lower cam portion consisting of an inclined cam surface 62c1 and a flat cam surface 62c2, including a shaft end portion 62a on the top, and a gear portion 62b on the bottom.
The upper cam 63 has an upper cam portion consisting of an inclined cam surface 63b1 and a flat cam surface 63b2.
The lower cam 62 and the upper cam 63 are combined, and an E type retaining ring 64 is fitted onto the shaft end portion 62a to integrate them as a unit, thus forming a cam groove (cylindrical cam) consisting of an inclined cam groove and a flat cam groove. Then, the integrated unit of the lower cam 62 and the upper cam 63 is mounted on the right upper face (on the left upper face in
As shown in
The driving side transmission member 73 has a cam follower portion 73a projecting from its outer circumference and an engaging protrusion portion 73b projecting forward.
The driven side transmission member 75 has a shaft portion 75a extending rearward, an engaging protrusion portion 75b projecting rearward, and a noncircular barrier engaging portion 75c provided at its front tip.
The driving side transmission member 73 and the driven side transmission member 75 are fitted in the shaft portion 75a so that they can rotate relative to each other. Further, as shown in
Under the above-mentioned combined condition, the rear end of the shaft portion 75a of the driven side transmission member 75 is inserted into a shaft hole 72a of the mounting plate 72, and the O ring 76 is inserted on the front end side and inserted into a shaft hole 2s of the front cover 2. Then, the mounting plate 72 is positioned by inserting a positioning hole 72b and a notch 72c onto a pin 2r and a positioning pin (not shown) of the front cover 2, respectively. Under this condition, screws are inserted into an insert hole 72d and an insert notch 72e, and tightened into a screw hole 2q and a screw hole (not shown, respectively, to fix the mounting plate 72 (
Then, as shown in
The barrier engaging portion 75c of the driven side transmission member 75 is inserted into a hole portion 77a of the lens barrier 77 to integrate the driven side transmission member 75 and the lens barrier 77 as an unit, so that the lens barrier 77 can be driven to rotate through the driven side transmission member 75.
Note that the shaft hole 2s of the front cover 2 is sealed by the O ring 76 mounted on the driven side transmission member 75 to make it watertight, that is, be resistant to moisture from the outside of the front cover 2. Further, when a force greater than a predetermined value is exerted on the driving side transmission member 73 in either of the directions from the lens barrier 77 side, or when a further rotation driving force is exerted on the driving side transmission member 73 in such a condition that the lens barrier 77 is in contact with a stopper, the torsion spring 74 is overcharged to rotate the driven side transmission member 75 and the driving side transmission member 73 relative to each other by an overcharged amount.
To be more specific, when the camera becomes power-on state, the upper and lower cams 63 and 62 rotate to θ3 via the rotation angles θ1 and θ2 to open the lens barrier. Therefore, the cam follower portion 73a moves from the barrier closed position BCL on the inclined cam surfaces 62c1 and 63b1 to reach the barrier open position BOP on the flat cam surfaces 62c2 and 63b2 via a barrier quasi-closed position BCL′ and a barrier quasi-open position BOP′. As a result, the lens barrier 77 reaches the open position completely out of the shooting window 12 as shown in
The barrier quasi-closed position is located slightly close to the barrier open position shown in
After that, when the upper and lower cams 63 and 62 further rotate from the rotation angle θ4 corresponding to a zoom wide-angle end (wide-angle photographable limit) to the rotation angle θ5 corresponding to a zoom telephoto end, the cam follower portion 73a continues to move on the flat cam surfaces 62c1 and 63b2, while the lens barrier 77 remains at the open position.
The following describes the states of the camera 1 when an impact force is exerted on the camera 1 in the Z direction in each of the barrier open and closed conditions. First, if an impact force is exerted in the Z direction in the power-off state, the lens frame body 17 moves slightly in the Z direction. Along with the movement, the upper and lower cams 63 and 62 move in the Z direction (back and forth) relative to the cam follower portion 73a of the driving side transmission member 73. When they move forward, if the moving amount corresponds, for example, to rotation angle θ-1 shown in
Thus, even if the lens frame unit 4 displaces by the application of impact or the like in the barrier closed condition, the lens barrier 77 remains covering the shooting window 12. This prevents trouble such as damage to the shooting window 12.
When the upper and lower cams 63 and 62 are at a position of rotation angle θ1, θ2, or θ3, even if the impact is exerted on the camera 1, the lens barrier 77 just moves to a corresponding position according to the relative movement of the upper and lower cams 63, 62 and the driving side transmission member 73. When the upper and lower cams 63 and 62 are at a position of rotation angle θ1, θ2, or θ3, it means that the lens barrier 77 is moving to open or close the shooting window 12. Therefore, there is no functional problem if a slight variation in movement occurs while the lens barrier 77 is moving.
Further, when the upper and lower cams 63 and 62 are at a position from the rotation angle θ4 to θ5, even if the impact is exerted on the camera 1, the cam follower portion 73a just moves on the flat cam portion of the upper and lower cams 63 and 62 without the movement of the lens barrier 77. When the upper and lower cams 63 and 62 are at a position from the rotation angle θ4 to θ5, it means that the camera is ready to shoot. Therefore, if the lens barrier 77 covers the shooting window 12 in this condition, it can interfere with shooting. In contrast, since the embodiment keeps the lens barrier 77 opening the shooting window 12, such a problem never arises.
As discussed above, when the camera 1 receives an impact force in the Z direction so that the lens frame unit 4 will move in the Z direction to absorb the impact, even if the relative position of the barrier connecting part 38 and the barrier driving transmission unit 71 slightly shifts, each of the mechanical parts is not involved in any problem as mentioned above, thereby causing no problem in opening or closing the lens barrier.
According to the camera 1 of the embodiment, the lens frame mounting parts are arranged in upper and lower positions on the left side of the camera, where the heavy components, such as the shutter actuator 37 and the focus actuator 35/focus unit 36 resides, by means of the lens frame unit 4. The lens frame unit 4 is supported movably in the Z direction through the rubber bushes. Therefore, the impact exerted on the camera 1 can be absorbed efficiently. Further, an inertia moment around an axis connecting the upper and lower lens frame mounting parts caused in the camera 1 by the impact force component in the Z direction is relatively small, and this can reduce the influence of the impact on the lens frame unit 4.
Further, when the position of the lens frame unit 4 shifts in the Z direction, although the relative position of the barrier connecting part 38 and the barrier driving transmission unit 71 also slightly shifts, the overcharge of the torsion spring 74 or the cam shape of the barrier connecting part 38 prevents the connecting mechanism or the driving transmission part from bad effects, and hence no trouble occurs in the movement of the lens barrier 77.
The lens frame mounting parts restrict the movement of the lens frame unit 4 in the X direction orthogonal to the optical axis plane. Therefore, the electric components arranged on the right side of the lens frame unit 4 of the front cover 2 can be housed very close to the lens frame unit 4, and this is effective in reducing the size of the camera.
Further, since the lens frame mounting parts are arranged on one side of the lens frame unit with respect to the optical axis plane, the freedom of movement to absorb the impact applied to the lens frame unit 4 can be increased, thereby improving impact resistance. In addition, the number of lens frame mounting parts can be reduced to two, and hence the unit can be made smaller.
Referring next to
A camera 1A of the embodiment is different from the camera of the first embodiment in the arrangement of component units housed inside the lens frame unit. Since the structure of the embodiment other than the arrangement is the same as that of the camera of the first embodiment, the following describes only the different point.
In the embodiment, a lens frame unit 4A is also mounted in the inner surface of the front cover 2 at upper and lower positions on the left side of the optical axis plane through the lens frame mounting parts arranged at two upper and lower points. Then, the shutter actuator 37 and the focus actuator 35/focus unit 36 are arranged in a lens frame unit 4A at upper and lower positions on the left side of the optical axis plane. The lens frame mounting parts position the lens frame unit 4A in the X and Y directions and support it to be minutely displaceable only in the Z direction in order to absorb impact forces.
Then, as shown in
In the embodiment, it is assumed that the structure of the lens frame mounting parts is the same as that of the first embodiment.
In the camera 1A of the embodiment, since the heavy barrier connecting part 38 and zoom actuator 33/zoom unit 34 are arranged in the vicinity of the lens frame mounting parts, the inertia moment around the axis connecting the upper and lower lens frame mounting parts caused in the camera 1A by the application of an impact force in the Z direction is made smaller, and this can reduce the influence of the impact on the lens frame unit 4A.
Based on each of the aforementioned embodiments of the present invention, the following structures can be proposed:
(1) A camera comprising:
a lens frame having a reflecting optical member for reflecting light from a subject incoming along a first optical axis toward a second optical axis intersecting the first optical axis;
a fixing member having an opening for guiding the subject light to the lens frame along the first optical axis and mounting the lens frame therein;
a lens barrier mounted in the fixing member in such a manner to be movable between a position to open the opening and a position to shut the opening;
a lens frame mounting part arranged on one side of the lens frame with respect to an optical axis plane defined by the first optical axis and the second optical axis;
a drive source arranged in the lens frame to drive a movable lens in the lens frame; and
a drive member arranged in the lens frame to drive the lens barrier,
wherein the lens frame is mounted in the fixing member through an elastic member arranged in the lens frame mounting part so that the lens frame will be restricted not to move in both a direction orthogonal to the optical axis plane with respect to the fixing member and a direction parallel to the second optical axis while being allowed to move in a direction parallel to the first optical axis in such a condition that the lens frame is mounted in the fixing member through the lens frame mounting part.
(2) The camera according to (1) wherein the drive member has a cam for driving the lens barrier, and the cam has a flat cam portion to make the lens barrier not to displace even if the lens frame moves with respect to the fixing member in the direction parallel to the first optical axis.
This invention is not limited to each of the aforementioned embodiments, and various modifications can be possible without departing from the scope of the invention in its practical phase. Further, each of the aforementioned embodiments includes various aspects of inventions, so that various inventions can be extracted from appropriate combinations of a plurality of elements disclosed in the appended claims.
The camera of the present invention can be used not only as a camera capable of holding a small lens frame having high impact resistance, but also as a camera which makes it easy to mechanically connect the lens frame with other mechanisms.
While there has been shown and described what are considered to be preferred embodiments of the invention, it will, of course, be understood that various modifications and changes in form or detail could readily be made without departing from the spirit of the invention. It is therefore intended that the invention not be limited to the exact forms described and illustrated, but constructed to cover all modifications that may fall within the scope of the appended claims.
Number | Date | Country | Kind |
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2006-015613 | Jan 2006 | JP | national |