Photography – With exposure objective focusing means – focusing aid – or... – Lens resetting
Reexamination Certificate
2000-12-19
2002-02-19
Perkey, W. B. (Department: 2851)
Photography
With exposure objective focusing means, focusing aid, or...
Lens resetting
C396S131000, C396S280000
Reexamination Certificate
active
06349173
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a camera with a lens barrel mechanism which is driven by a motor only in one rotational direction, wherein rotational power of the motor in the other direction is used for driving another mechanism.
2. Background Arts
An instant camera takes a photograph on a sheet of instant film by exposing the instant film to an optical image of a subject formed through a taking lens. After the exposure, a film feed out mechanism is driven to feed out the exposed instant film. The film feed out mechanism is constituted of a claw mechanism and a pair of developing rollers, and is driven by a motor. The claw mechanism rakes the exposed instant film out of a film pack loaded in the instant camera and feeds it toward the developing rollers. Then, the developing rollers nip and feed out the instant film through a film exit of the instant camera. While the instant film is squeezing through the developing rollers, a pod containing a developing solution is broken and the developing solution is spread over the exposed instant film. Thereby, a latent picture photographed on the instant film is developed to be a visible positive picture.
Because the sheet size of the instant film is relatively large, the instant camera must have a sufficiently large room for loading the instant film, so it is difficult to make the instant camera compact in comparison with 35 mm cameras and APS cameras using IX 240 type film. In order to improve the portability of the instant camera, JPA 4-194829 discloses a collapsible instant camera wherein a lens board having a taking lens therein is mounted to a camera body through bellows so that the board may be folded onto a front wall of the camera body or protruded from the front wall. Because the collapsible instant camera is complicated in construction and needs a large number of parts, the production cost is high and the collapsible instant camera comes to be expensive.
It is desirable to introduce such a lens barrel in the instant camera that has been used in conventional compact cameras and is movable between a stowed position and at least a protruded position, but there are many problems to solve in practice. It is necessary to provide a second motor for driving the lens barrel besides the motor for the film feed out mechanism, since the movable lens barrel is driven by a motor in one direction to protrude or in a second or opposite direction to retract. In addition, where the taking lens is focused through a focusing mechanism that is driven by a different motor from that used for protrusion and retraction of the lens barrel, the instant camera must mount at least three motors. This is disadvantageous in view of compactness and cost.
To reduce the number of motors, JPZ 1869801 discloses a teaching to use rotational power of a motor in one direction for moving a lens barrel between a wide-angle position and a telephoto position, and rotational power in the other or opposite direction for driving another mechanism, e.g. a film advancing mechanism or a shutter charging mechanism. Also, JPA 9-236854 discloses a teaching to drive a film advancing, winding and rewinding mechanism by rotating a motor in one direction and drive another mechanism by rotating the motor in the other direction.
However, these prior arts just propose the teaching, and do not disclose any concrete solution for the achievement. For instance, there is no teaching how to move the lens barrel in opposite directions by rotating the motor in one direction, or how to focus the taking lens. Moreover, the torque necessary for driving one mechanism is usually different from that for another mechanism. When using the rotational power of the same motor for different mechanisms, the difference in the torque must be taken into consideration. Otherwise, the mechanism cannot operate stably and would rise a certain noise.
Meanwhile, many of instant cameras and inexpensive cameras use a taking lens with a relatively short focal length and a relatively small lens aperture, so that the taking lens covers a wider subject distance range within the depth of field. In those instant cameras or inexpensive cameras, the whole subject distance to cover is often divided into several zones, e.g. near, middle and far distance zones, and the taking lens is designed to be set to one of several focusing positions determined for the respective subject distance zones. It is well-known in the art to provide a manually operated zone focusing device instead of or in addition to an automatic focusing device. The zone focusing device allows the photographer to designate one of predetermined subject distance zones so as to focus the taking lens on the designated subject distance zone.
In the conventional zone focusing device, an operation member, such as a switching lever or dial, is connected to a focusing ring of the taking lens through an interconnection mechanism to switch over the focusing position by rotating the focusing ring through the operation member. So the operation member has been located in proximity to the taking lens to improve the space efficiency and simplify the interconnection mechanism. However, the conventional location of the operation member of the zone focusing device is not handy for the photographer, and also limit the layout of other camera elements.
SUMMARY OF THE INVENTION
In view of the foregoing, an object of the present invention is to provide a camera, wherein a lens barrel of a taking lens can move back and forth along an optical axis by rotating a motor in one direction.
A further object of the present invention is to provide a camera, wherein rotational power of a motor in one direction is used for focusing as well as for moving a lens barrel back and forth.
Another object of the present invention is to provide a camera which uses rotational power of a motor in one direction for driving a lens barrel mechanism, and rotational power of the motor in the other direction for driving another mechanism, while considering differences in necessary torque between these mechanisms.
Still another object of the present invention is to provide a camera with a manually operated zone focusing device wherein an operation member of the zone focusing device may be located in an appropriate position without lowering the space efficiency of the camera.
According to the present invention, a camera is comprised of a barrel driving assembly immovable in the direction of an optical axis of the taking lens and including a drive ring, the drive ring being rotated about the optical axis in one direction when a rotational power of a motor in a first direction is transmitted to the drive ring; a movable barrel assembly holding a taking lens therein, and movable back and forth along the optical axis of the taking lens relative to the camera body; and a cam mechanism interconnecting the barrel driving assembly and the movable barrel assembly such that the movable barrel assembly makes at least one stroke of reciprocative movement along the optical axis while the drive ring makes one revolution in the one rotational direction.
According to this configuration, it is possible to use a rotational power of the motor in a second direction for driving a second mechanism, such as a film feed out mechanism for an instant film unit or a film advancing mechanism for a roll film. Therefore, it is unnecessary to provide a separate motor for the second mechanism.
By interconnecting the drive ring with the motor through a clutch mechanism that is switched over according to rotational direction of the motor, the rotational power of the motor in the first direction is transmitted to the drive ring, and a rotational power of the motor in the second direction to the second mechanism.
According to a preferred embodiment, a motor drive device of the camera supplies a different amount of electric power per unit time to the motor for rotating the motor in the first direction from that supplied for rotating the motor in the second direction, in accordance with differences
Aosaki Ko
Izaki Toshihiko
Kanai Masaharu
Nakamori Masao
Naruse Mutsumi
Fuji Photo Film Co. , Ltd.
Perkey W. B.
Young & Thompson
LandOfFree
Camera with motor-driven lens barrel does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Camera with motor-driven lens barrel, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Camera with motor-driven lens barrel will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2977839