Photography – With film drive – Double exposure prevention
Reexamination Certificate
1999-09-22
2001-08-21
Perkey, W. B. (Department: 2851)
Photography
With film drive
Double exposure prevention
C396S413000
Reexamination Certificate
active
06278848
ABSTRACT:
BACKGROUND OF THE INVENTION
The camera of this invention preferably includes a rewind interlock that prevents accidental advancing of exposing film after it has been rewound into a film cassette. Preferably, the camera of this invention is a manual Advanced Photo System (APS) reusable camera. This application contains subject matter that is related to commonly assigned co-pending patent application Ser. No. 09/400,965 entitled “Camera With Combined Film Advance/Rewind Mechanism,” which is hereby incorporated by reference.
Cameras typically have a film cassette compartment for receiving a film cassette, a film spool and a film path. The film spool is generally rotatably mounted to the camera and disposed in a film spool compartment on a side of the camera opposite the side that the film cassette compartment is disposed. The film path is defined by the region between the film cassette compartment and the film spool compartment and typically includes the film exposing area. Once a film cassette is loaded into the camera, film is typically loaded by moving the film out of the film cassette, and along the film path, and then winding the film around the film spool. As exposures are taken, the film is then moved from the film spool and the film path back into the film cassette.
In order to load film around the film spool, motorized 35 mm. cameras typically have a motor that rotates the film spool to pull the film out of the film cassette, draw it across the film path and wind it around the film spool. Before loading the film, an exposed film leader extending from the 35 mm. film cassette has to be manually wrapped around the film spool. In order to rewind the film back into the film cassette after exposures are taken, the same motor or another motor rotates a spindle of the film cassette to pull the film back into the film cassette.
Relatively recently, Advanced Photo System (APS) film has been developed. An APS film cassette does not have an exposed film leader, but rather has a light lock door for light sealing the film within the cassette. APS film is thinner than conventional 35 mm. film and unlike 35 mm. can be thrust from a cassette. In fact, APS film must be thrust from the cassette in order to initially move the film out of the cassette because it does not have an exposed film leader. In order to load APS film, the light lock door of the film cassette is opened and the film is thrust from the cassette by rotating a spindle of the film cassette. In one type of APS camera the film is loaded around the film spool prior to exposing the film. This includes thrusting the film across a film exposure area and around a film spool. In order to complete the loading process, the film is wound around the film spool. After loading is complete the first frame to be exposed rests in the film exposing area and the other frames are wrapped around the film spool. After exposure of a frame, the exposed frame is moved into the film cassette and the next frame to be exposed is moved from the film spool to the film exposing area.
Other types of APS cameras do not “load” film as described above. Rather, in these other APS cameras the first frame of film is advanced from the cassette to the film exposing area. After exposure of this frame, the exposed frame is moved to the film spool and the next frame to be exposed is moved from the film cassette to the film exposing area. This process continues until all of the exposures have been taken. After which, the film is moved from the film spool across the film exposing area and back into the film cassette.
In motorized APS cameras, a motor may be used to rotate the spindle of the film cassette and thrust the APS film from the cassette. Once the APS film has begun winding around the film spool, the film spool may be rotated by the same motor or a separate motor to completely wind the film around the film spool.
It will be appreciated that since 35 mm. cameras do not thrust film and APS cameras need to thrust film out of the film cassette, mechanisms have to be developed to thrust APS film. Further, in manual type APS cameras, non-motorized mechanisms need to be developed to thrust APS film. This invention relates to an improved camera for thrusting APS film from and rewinding APS film into an APS film cassette that has a light lock door. This invention also relates to a camera that has an interlock that prevents a camera user from thrusting film from the film cassette, when film is to be rewound and rewinding film into the film cassette, when film is to be thrusted.
SUMMARY OF THE INVENTION
The camera of this invention is preferably a manual reusable APS camera. However, it need not be this type of camera and features of this invention may be employed with other types of cameras. The camera of this invention may have a combined advance/rewind mechanism for advancing or thrusting film out of a film cassette and for winding film back into the film cassette. Further, the camera of this invention preferably includes a film cassette compartment, a film path and a film spool. The film cassette compartment defines an area within the camera for receiving a film cassette. Preferably, the film cassette compartment may receive an APS film cassette. The film spool is rotatably mounted to the camera, so that film from the film cassette may be wound around the film spool. Disposed between the film cassette compartment and the film spool is the film path. The film path also defines an exposure area in which the film is exposed to create images on the film.
In one embodiment, after a film cassette is loaded into the camera, the leading edge of the film is moved from the film cassette along the film path and to the film spool, and the first frame of film is disposed within the film exposing area. After the first frame of film is exposed, that frame is advanced to the film spool and the next frame is advanced to the film exposing area. Operation of the camera continues in this fashion until all of the desired exposures are taken. After the film has been exposed and it is desired to remove the film cassette from the camera, the film is rewound into the film cassette by moving the film from the film spool along the film path and back into the film cassette.
The combined advance rewind mechanism is rotatably mounted to the camera and may be coupled to a spindle of the film cassette. When rotated in a first direction, the combined film advance/rewind mechanism thrusts film out of the film cassette by rotating the film cassette spindle. The combined advance/rewind mechanism may also rotate the film spool when it is rotated in the first direction to pull film around the film spool after the film has been thrusted to the film spool. In comparison, when the combined advance/rewind mechanism is rotated in a second direction, the film cassette spindle is rotated in a second direction to wind film into the cassette and around the spindle of the cassette. A gear train may also be included within the camera that couples the combined film advance/rewind mechanism to the spindle of the film cassette and to the film spool.
In order to load the film, the combined film advance/rewind mechanism is rotated in the first direction to rotate the spindle of the film cassette and to rotate the film spool. The rotation of the spindle causes the leading edge of the film to be thrust out of the film cassette and into the film path. As, the film enters the film path, the leading edge of the film crosses the film path and reaches the film spool, which is also rotating due to the rotation of the combined film advance/rewind mechanism. Rotation of the film spool pulls or winds the film around the film spool. Further rotation of the combined advance/rewind mechanism in the first direction winds the leading edge of the film onto the film spool. After each frame of film is exposed in the film exposing area, the film spool is rotated to pull the exposed frame of film around the film spool and to advance the next frame of film to be developed to the film exposing area. After the pictures have been taken with
Concord Camera Corp.
Perkey W. B.
Woodcock Washburn Kurtz Mackiewicz & Norris
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