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Automatic Film Threading Camera

IP.com Disclosure Number: IPCOM000081410D
Original Publication Date: 1974-May-01
Included in the Prior Art Database: 2005-Feb-28
Document File: 4 page(s) / 119K

Publishing Venue

IBM

Related People

Galatha, MJ: AUTHOR

Abstract

This arrangement provides automatic film threading into a camera from a film cassette where no free end of the film web is available.

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This is the abbreviated version, containing approximately 53% of the total text.

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Automatic Film Threading Camera

This arrangement provides automatic film threading into a camera from a film cassette where no free end of the film web is available.

The camera box houses a lens, automatic iilm threading mechanism, and the film transporting components. The lens is positioned in a mount that can be retracted from the film. When the lens mount is in the closed position, the film is registered against the rear surface of the mount by a spring loaded pressure plate.

The components that transport the film are mounted on a retractable plate. Two vacuum columns provide the film tension around a capstan and buffer the film supply and take-up loads from the capstan. The capstan and the film gate are located between the two vacuum columns. The capstan is located on the take-up side of the film gate and draws film through it. The geometry of the film gate, capstan, and vacuum columns results in 180 Degrees wrap of the film around the capstan. The wrap, the normal force from the film tension, and the coefficient of friction between the film and capstan surface provide a friction force that allows the capstan to positively control the film during acceleration and deceleration.

Film is drawn into the camera box from the supply side of the cassette and taken out of the camera box into the take-up side of the cassette, under the control of film sensors in the vacuum columns.

Servomotors, one each driving the cassette supply and take-up spindles, control the amount of film delivered to the supply and takeup vacuum columns. The position of the film loop is sensed in each column by a sense unit whose output controls the servomotors.

Referring to Figs. 1A and 1B, there are shown schematically the relations of the parts in an unloaded state, in which the film transport mounted on plate 3 and lens mount 5 are in a retracted position, and a load column plate 7 is flush against the front opening in the stationary load column.

What has been formed is a rectangular column, open only at the top. A column door 9, covering the column rails 11 and 13 and attached to the retractable transport plate 3, has been retracted into an opening in the rear side of stationary load column 15, to a position where the front surface of column door 9 is in the same plane as the rear inside surface of stationary load column 15. The lens mount has been retracted to a position where the aperture plate surface is in the same plane as the left inside surface of stationary load column 15. As column door 9 was retracted, spring-urged load column plate 7 moved to fill the rectangular opening in the front side of stationary load column 15.

A film cassette, not shown, is loaded onto the cassette drive spindles, not shown. A rectangular opening in the bottom of the cassette mates with the opening at the top of column 15. Film...