Photography – Camera detail – Detachable or removable film holder unit
Reexamination Certificate
1999-09-22
2001-08-28
Mathews, Alan A. (Department: 2851)
Photography
Camera detail
Detachable or removable film holder unit
C396S392000, C396S413000, C396S513000, C396S516000
Reexamination Certificate
active
06280103
ABSTRACT:
BACKGROUND OF THE INVENTION
This invention relates to a camera that has a parking mechanism for ensuring that the visual exposure indicator (VEI) of an Advanced Photo System (APS) film cassette is in the “parked” or “x” position when the film cassette is removed from the camera and exposed to light.
Advanced Photo System film cassettes, as shown in
FIG. 1
, have a visual exposure indicator disposed in the bottom of the cassette. The visual exposure indicator includes an icon and the plastic covering over the bottom of the film cassette. This visual exposure indicator has four positions, a circle, a half circle, an “x” and a rectangle, as shown in FIG.
1
. Each of the shapes, the circle, half circle, “x” and rectangle are defined as an opening in the plastic covering disposed in the bottom of the cassette. The icon is disposed inside of the cassette and moves relative to the openings, so that it can be seen through one of the openings. When visible through one of the openings, the icon is visible as the defined shape of the respective opening.
The status of the film in the film cassette is indicated by the position of the icon relative to the openings. If the icon is visible through the circle, it indicates that the film has not been exposed and the film cassette is ready for use. When visible through the half circle, the icon indicates that the film has been thrust from the cassette or partially exposed. The “x” indicates the exposed or “parked position” in which the film has been rewound into the cassette. Finally, the rectangle indicates that the film has been processed or developed. The VEI of the cassette is beneficial because the status of the film can be quickly obtained by examining the VEI. Therefore, it is important to ensure that the VEI always indicates the proper status of the film. For example, if the VEI was in the wrong position, it may be mistakenly understood that the film has not been completely exposed when it has.
The icon of the VEI operates with the spindle of the film cassette. By rotating the spindle, the VEI is moved to the various positions. In order to move the icon to the “x” position, the trailing edge of the film must be rewound into the cassette after the light lock door of the cassette has been closed. Potentially, the VEI could remain in the half circle position when the trailing edge of the film enters the cassette and the light lock door is closed. The spindle must be rotated a further distance after the closing of the light lock door to ensure that the VEI moves to the “x” position.
Motorized APS cameras typically ensure the spindle is rotated this further distance by detecting the film is fully inside of the cassette
14
or the closing of the light lock door and then rotating the spindle a predetermined rotational distance that corresponds to the VEI moving to the “x” position. Detection can be done with a film sensor that detects movement of the trailing edge of the film into the film cassette. Alternately, a mechanism that operates with the light lock door and senses the movement of the light lock door to the closed position can be used. Since the camera is motorized, circuitry can be used to ensure the motor rotates the spindle this predetermined rotational distance after the light lock door is closed.
In order to reduce the cost of APS cameras, its desirable to develop manual APS cameras. These cameras are termed “manual” because they would not have a motor for moving the film. Rather, they would have a mechanism, such as a thumb wheel or a crank, that can be manipulated by a camera user to manually move the film within the camera. Since such a camera does not have a motor, the camera user must rotate the spindle after the closing of the light lock door to ensure that the VEI moves to the “x” or parked position. Potentially, the camera user could drive the trailing edge of the film into the film cassette
14
and close the light lock door and stop further movement of the film. At this point, the VEI may still be in the half circle position. Further, the camera user could then remove the cassette from the camera. A later inspection of the film cassette would incorrectly indicate that the film has not all be exposed. Thus, there is a need for the camera user to know when the VEI has moved to the parked position.
This invention relates to a camera that has a mechanism for ensuring that the VEI of an APS film cassette is in the proper position after the film has been exposed and rewound into the film cassette. This invention also relates to such a mechanism that can be employed with a manual APS camera.
SUMMARY OF THE INVENTION
The camera of this invention preferably includes a parking mechanism for ensuring that the visual exposure indicator of an APS film cassette moves to the parked position after all the film has been rewound into the film cassette. The camera may further include a film cassette compartment into which an APS film cassette may be light sealed, a film path and a film spool. The film preferably moves along the film path between the film cassette compartment and the film spool after each exposure and when the film is rewound into the film cassette. The camera may also include a film advancing mechanism which is manipulated by a camera user to move the film along the film path. When the film cassette is inserted into the film cassette compartment, the film advancing mechanism is coupled to a spindle of the film cassette in order to move the film into and out of the film cassette.
The film advancing mechanism preferably includes a rotatable wheel and a wheel gear. The rotatable wheel may be manipulated by a camera user to manually move film along the film path. Preferably, the wheel gear is coupled to the rotatable wheel, so that the wheel gear rotates with the wheel. The rotatable wheel gear preferably has a cam slot disposed in a wall and an inner periphery along which an entrance of the cam slot is disposed. The cam slot preferably extends around the wall a sufficient distance to ensure that the visual exposure indicator moves to the park position after all the film has been rewound in the film cassette. A pocket may be disposed at the end of the cam slot. The rotatable wheel gear has an interior wall that defines a cavity inside of the wall.
The parking mechanism may include a parking lever that is rotatably mounted to the camera. The parking lever preferably has a parking pin extending from the lever that rests within the cavity defined by the advance wheel gear. When the advance wheel gear is being rotated to move film within the camera, the parking pin preferably remains stationary within the cavity. After the film has been exposed and as the trailing edge of the film is being rewound into the film cassette, the parking lever is preferably rotated so that the parking pin moves towards the cam slot and enters the cam slot. Further rotation of the advance wheel, will move the advance wheel gear and the cam slot relative to the parking pin. Prior to the pocket of the cam slot contacting the parking pin, all of the film is rewound into the film cassette. Further rotation of the advance wheel gear moves the pocket of the cam slot to contact the parking pin. At this point, further rotation of the advance wheel gear and therefore, the advance wheel is prevented by the parking pin. This indicates to the camera user that the visual exposure indicator has moved due to the rotation of the advance wheel gear to the parked position and that the film cassette is ready to be removed from the camera. The parking mechanism provides this indication because the wheel is rotated sufficiently after the trailing edge of the film has entered the film cassette to ensure that the visual exposure indicator has moved to the park position.
The parking mechanism may further include a parking spring that is mounted to the camera and the parking lever. The parking spring biases the parking lever to rotate, so that the parking pin rotates toward the interior wall of the wheel. In addition, the camera may further include a film sensor disposed wit
Bittner Wilfried
Chung Franco Yik Kai
Zawodny Arthur
Concord Camera Corp.
Mathews Alan A.
Woodcock Washburn Kurtz Mackiewicz & Norris LLP
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