Film transport device

Details Film transport device Film transport device

1990-10-26

1992-06-16

Hayes, Monroe H.

Optics: motion pictures

With loop forming

352157, 352 14, G03B 156

Patent

active

051219824

DESCRIPTION:

BRIEF SUMMARY
The invention relates to a film transport device.
DE-A1-31 27 778 teaches a device for transporting and guiding a film in a film projector, said device having supply and takeup plates mounted on fixed positions on both sides of the film gate, with one drivable sprocket associated with each plate. The two sprockets, a loop forming device, and a film pressure skid are mounted on a movable carriage, said carriage being displaceable on tracks integral with the system, parallel to the optical axis of the lens of the film projector between a freely accessible supply and rewind position and a projection position.
At the beginning of the projection mode, the film pressure skid is displaced against a film contact rail comprising the film gate, with the loop forming device automatically forming a loop at this time between the takeup sprocket and the film contact rail and between the film contact rail and the supply sprocket. In this known device, however, it is necessary to incorporate an intermediate stop to switch from the supply and rewind positions to the projection position.
DE-C2-30 27 882 teaches a film transport device for a motion picture camera, said device having two separate sprockets for supplying the unexposed film and for winding up the exposed film on a film takeup reel. Coupling devices are provided between the drive system for the separate sprockets and the sprockets to influence the rotation of the sprockets. Because of the continuous film transport by the sprockets and the intermittent film transport in the vicinity of the film gate, film loops must be provided before and after the film gate, said loops being formed by a relative twisting of one film transport sprocket relative to the other film transport sprocket.
However, in film projectors, in contrast to motion picture cameras, it is necessary for loop formation to be completed quickly to ensure a short time interval until the film projectors are fully ready to operate. To locate certain frames in the film, it is necessary in many applications in medicine, sports reporting, and the like to insert films into the film projector, project film sequences, and remove the films from the projector once more. In known projectors, this procedure is cumbersome and extremely time-consuming.
The goal of the invention is to provide a film transport device which ensures that only a brief time interval elapses until the projector is fully ready to operate and permits simple and rapid startup, and insertion and removal of a film as well as creating the precondition for being able to remove even partially unreeled film reels from the projector.
The solution according to the invention provides a film transport device which permits simple and comfortable operation of the projector during startup and during insertion as well as removal of the film. To insert the film it is merely necessary to place the film reel on an empty winding plate, feed the film into the wide open film channel, and attach the end of the film to the opposite empty core by turning it several times. At the press of a button, all other steps, including closing the film channel and forming the loop, take place automatically in one to two seconds to achieve complete operational readiness. To remove the film when the film reels are partially unwound, the film channel is opened again at the press of a button and the film can simply be removed without any danger of damaging the film.
Advantageous improvements of the invention will be described in greater detail below together with the description of the preferred embodiment of the invention, with reference to the figures.
FIG. 1 is a schematic perspective view of the film channel, with the individual drive elements;
FIGS. 2 to 4 show a top view of the film projector in various phases of film loop formation; and
FIG. 5 is a simplified block diagram of the automatic delivery system and control circuit.
The schematic perspective view shown in FIG. 1 of the important drive elements of the film projector according to the invention shows film transport d

REFERENCES:
patent: 1973477 (1934-09-01), Fritts
patent: 3119300 (1964-01-01), Barocela
patent: 3490837 (1970-01-01), Pierez et al.
patent: 3642357 (1972-02-01), Meyer
patent: 3702726 (1972-11-01), Takeichi et al.
patent: 3734602 (1973-05-01), Deck
patent: 4037949 (1977-07-01), Pasturczak et al.
patent: 4146313 (1979-03-01), Feltz et al.
patent: 4150886 (1979-04-01), Merkel et al.
patent: 4697896 (1987-10-01), Fox

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