Document Type and Number:
Japanese Patent JPS50151148
Kind Code:
A
Abstract:
A film cartridge loaded with a roll of motion picture film having a magnetic stripe on one surface of the film is subject to shaking or impacts during handling of the cartridge which results in displacement of some convolutions of the film in a direction parallel to the axis of the film roll, especially when the film has first clocksprung in a radial direction. When this occurs, friction between the displaced convolution and the adjacent convolutions of the film effectively prevents return of the stepped convolution to its original position. Subsequently, when film is to be pulled from the supply roll during operation of a camera in which the cartridge is positioned, the stepped convolutions can contact a wall of the cartridge defining the supply chamber in the cartridge and produce a frictional force that opposes normal unwinding of the film. This can result in improperly exposed film. In order to avoid the undesirable results from stepped film, the film supply chamber is expanded in a direction parallel to the axis of the roll when the cartridge is inserted into the camera and the cartridge chamber cover or door is closed. This expansion is effected by a member that is pivoted against a wall of the supply chamber by an actuator which may be located on a camera door.
Application Number:
JP5244975A
Publication Date:
December 04, 1975
Filing Date:
April 30, 1975
Export Citation:
International Classes:
G03B31/00; G03B17/26; (IPC1-7): G03B31/02