Processing method and apparatus for exposed and developed film with position sensing

Abstract

An exposed and developed filmstrip has a longitudinally extending row of image areas and a row of perforations along each longitudinal margin. The image areas and perforations have no fixed positional relationship. The filmstrip is conveyed lengthwise from a scanning station to an operating station. A procedure involving the filmstrip is performed at the operating station when an image area is present at such station. To establish the arrival of an image area at the operating station, the filmstrip is photoelectrically scanned at the scanning station to locate the leading edge of the image area. The leading edge is conveyed from a preselected location, which may or may not be the scanning station, to the oeprating station along a path of fixed length. The length of the path is expressed in terms of the spacing between neighboring perforations of a row and the arrival of the leading edge at the operating station is established by counting perforations as the filmstrip travels. Fractions of the perforation spacing, which may arise if the leading edge is located between two perforations or if the path length is not an integral multiple of the perforation spacing, are measured by counting the steps performed by a stepping motor which drives the filmstrip or by counting the revolutions of rollers which engage the filmstrip.

Dependencies are inferred from the claim text.