Abstract: A double speed intermittent film pull down for a movie projector (100) comprises a sprocket (122), which advances the film (114) a frame at a time. A star wheel (140) is mounted on a common shaft (132) with the sprocket (122). A cam (134) turns the sprocket (122) every other rotation of the cam (134). A shutter (106) is mounted on a common shaft (132) with the cam (134) and interrupts light to the frame of the film (114). The common shaft (132) for the cam (134) and shutter (106) turns at approximately twice the speed of the common shaft (132) for the star wheel (140) and sprocket (122).

Abstract: A telecine scanner, with which the horizontal picture steadiness errors are reduced by the film guidance in the area of the film gate 5, includes a first guiding element 11 supporting one of the longitudinal edges of the film 4 at at least two points in the film gate 5 in the area of the radiation path 6. In addition, two guiding elements 12 are provided, which are spaced substantially centrically apart from the first guiding element 11 and engage the other longitudinal edge of the film 4.

Abstract: An intermittent drive mechanism for film is disclosed. A driven wheel having sprocket teeth for engagement in perforations in film is coupled by face teeth with the driving wheel and supported for turning about a common axis provided by a supporting shaft. The driving wheel is oscillated by an arm also supported on the common shaft. The teeth on both the driving and driven wheels have a saw-tooth shape and mesh to turn the ratchet wheel when the driving wheel is turned in one direction by the arm, and cooperate to move the driving wheel axially to an idle position when the driving wheel is turned in the other direction by the arm. Also disclosed is a bi-directional drive in which a driving wheel having face teeth on both lateral faces is provided and which is movable axially to bring one or the other sets of face teeth into operative engagement with axially spaced driven wheels having similar face teeth.

Abstract: A film drive for a motion-picture camera or projector has a film drive wheel which is rotatable about a first axis and has a plurality of angularly equi-spaced and radially extending teeth. A function cam rotatable about a second axis spaced from and perpendicular to the film axis has a generally helical peripheral formation which engages with the teeth of the wheel. This helical formation includes an intermittent-drive section having a holding portion constituting almost a complete turn of the formation of zero degree pitch and a switching portion at each end of the holding portion of predetermined pitch greater than zero degrees, and a constant-drive section of constant pitch greater than zero degrees and axially offset from the intermittent-drive section.