Photography – Single lens reflex camera – With mirror support or drive
Reexamination Certificate
1998-06-04
2001-01-16
Perkey, W. B. (Department: 2851)
Photography
Single lens reflex camera
With mirror support or drive
C396S391000, C396S402000, C396S443000
Reexamination Certificate
active
06174093
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a motor-driven single-lens reflex camera and to a motor-driven single-lens reflex camera for self-feeding film cartridge, in which a single motor drives both a mirror/shutter system and a film feeding system.
2. Description of the Related Art
In regard to a motor-driven single-lens reflex camera constituting a motor to control an up/down operation of mirror and to carry out a shutter charge by driving a mirror/shutter driving system, and another motor to feed (wind) and rewind a film by driving a film feeding system, although it is possible to increase the speed of feeding of the film after exposure (namely, the frame feed speed), it is still difficult to minimize the size of camera because a larger space is required to mount two motors thereon, which further results in higher cost. Accordingly, there has been suggested a single-motor type of single-lens reflex camera, which drives both the mirror/shutter driving system and the film feeding system by the single motor, so that the minimumizing of space and cost of the camera can be accomplished. There are such type of cameras in the related art, for example, in which a film is fed by a sprocket capable of feeding by a regular angle, or in which a film is fed by driving a spool (Japanese unexamined patent publication No.1-202731, duly published after examination under No.8-10313). However, the related art makes the single motor carry out a plurality of tasks, thus transmission systems thereof may become complicated.
The camera of the above-mentioned related art carries out an up/down operation of a mirror and a shutter charge by rotation of a motor in one direction (forward direction), and a feed and a rewind of film by rotation of the motor in the opposite direction (reverse direction). In this structure, during a release operation, the motor is initially stopped after an operation of the mirror/shutter system, then the film is fed by the reverse rotation of the motor. Therefore the frame feed speed (the speed of film feed per frame) becomes slower, hence the camera is not suitable for sequential photographing.
In addition, although the single-motor type of single-lens reflex camera may minimize the size and cost of the camera, there are limitations to the various operation modes and faster driving speed due to complicated switching of driving directions. For example, it is difficult to operate at multiple exposures, which is different from ordinary photographing operations.
There is a camera complying with a new photographic system called “Advanced Photo System” which uses a self-feeding film cartridge. Under such a new system, since there are novel operations during loading of the film such as “film thrust” (setting the first film-frame) or “rewind write, (rewriting of magnetic data), that are not performed in regard to the conventional camera using 35 mm-type of film, it is difficult to control these novel operations by a single-motor type of single-lens reflex camera of the related art.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a single-lens reflex camera which drives a mirror shutter driving system and a film feeding system by a single motor in a simple structure so that the size and cost of camera is minimumized.
It is another object of the present invention to provide a single-motor type of single-lens reflex camera which can perform multiple exposure in a simple structure.
It is still another object of the present invention to provide a single-motor type of single-lens reflex camera for self-feeding film cartridge which can rewrite the magnetic data in a simple structure.
To achieve the object mentioned above, according to the present invention, there is provided a motor-driven single-lens reflex camera, which controls and executes, through rotation of a single motor in a forward or a reverse direction, a mirror up operation, a mirror down operation and a shutter charge operation by a mirror/shutter driving system, and also a film winding operation and a film rewinding operation by a film feeding system, wherein the mirror up and the shutter charge release operations are executed through forward rotation of the motor, and the mirror down, the shutter charge and the film winding/rewinding operations are executed through reverse rotation of the motor. Thus the speedy film feeding after exposure can be made by switching from the mirror down and film charge operations to the film winding operation without stopping or reverse driving of the motor.
Further, the motor-driven single-lens reflex camera is provided with: a first clutch mechanism, including a latch lever movable between a clutch-engaged position and a clutch-disengagable position, which transmits the drive of the motor to the mirror/shutter driving system in a direction corresponding to rotation of the motor in the forward or reverse direction when the latch lever is at the clutch-engaged position, and which engages the motor either with the mirror/shutter driving system or with the film driving system via switching thereto according to the rotation of the motor in the forward or reverse direction when the latch lever is at the clutch-disengagable position; a second clutch mechanism, including a force lever movable between a winding position and a rewinding position, which engages the motor with a winding system when the force lever is at the winding position, and which switches the motor so as to be engaged with a rewinding system, in a state that the first clutch mechanism engages the motor with the film feeding system; a rotating cam, (a single-rotation cam) which is rotated when the first clutch mechanism engages the rotation of the motor with the mirror/shutter driving system, which maintains a mirror down position and a shutter charge state at a charge position, and which lifts a mirror and releases the shutter charge state at an exposure angular position which is different from the charge position; a force lever cam, provided in the rotating cam, which forcibly moves the force lever from the winding position to the rewinding position, when the rotating cam is at a rewinding angular position which is assigned at an angular position opposite to the exposure angular position with respect to the position of the charge position; and a latch lever moving means, which moves the latch lever to the clutch-engaged position when the rotating cam is at the exposure angular position, and which also moves the latch lever to the clutch-disengagable position when the rotating cam is either at the charge position or at the rewinding angular position.
Accordingly, in a release operation, an exposure is executed by driving the motor in the forward direction so that the rotating cam is rotated in the forward direction to be moved from the charge position to the exposure angular position, then the mirror down operation and the shutter charge operation are executed by driving the motor in the reverse direction so that the rotating cam is rotated in the reverse direction to be moved from the exposure angular position to the charge position, and the film winding operation is executed by driving the motor in the reverse direction.
Preferably, the latch lever moving means includes a spring member to apply force to the latch lever in order to set the latch lever at the clutch-engaged position; and a latch lever cam, provided in the rotating cam, which forcibly moves the latch lever from the clutch-engaged position to the clutch-disengagable position, when the rotating cam is either at the charge position or at the rewinding angular position. With this structure, since the movement of the latch lever depends on the position of the rotating cam, it is impossible, for example, to rotate in reverse from the charge position toward the rewinding angular position. Therefore, the camera according to the present invention may include an electromagnet to hold a shutter, wherein in a film rewinding operation, the electromagnet is initially actuated so as to prevent movement
Itabashi Tomoaki
Kitazawa Toshiyuki
Asahi Kogaku Kogyo Kabushiki Kaisha
Greenblum & Bernstein P.L.C.
Perkey W. B.
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