发明名称 Method of automatically detecting the locations of the frame lines of a reversal film and apparatus for carrying out the method
摘要 A method of automatically detecting the locations of the frame lines of a reversal film as it is supplied to a processing station, such as a cutting and mounting station, a notching station or the like, so that the frame lines can be used as reference marks for the positioning of the film in the processing station wherein the film is moved past optoelectronic scanner in steps which amount to only a fractional part of the normal width of a frame line. The scanner generates an analog voltage which represents the accumulated light transmission of the film in a scanned area, which extends at right angles to the direction of travel of the film substantially across the picture area of the film and has a width which is only a fractional part of a normal width of a frame line. The extreme value of the voltage obtained during a scanning of at least one normal frame length and corresponding to the lowest light transmission is evaluated as a representation of the light transmission of the scanned film at a frame line. This evaluation is so improved that a confusion between frame lines and framelinelike picture elements will be reliably precluded. The analog voltage is digitalized and the digital data obtained for each step of travel are stored for an interval of time which corresponds to the travel over a plurality of frame lengths. The stored digital data are compared over time with each other and those digital data which represent the extreme voltage value are regarded as being associated with a frame line if the number of such data which occur in an uninterrupted sequence corresponds to a frame line width, with a predetermined tolerance allowance, and are regarded as being associated with an unexposed frame area if a larger number of such data occur in an uninterrupted sequence.
申请公布号 US4673815(A) 申请公布日期 1987.06.16
申请号 US19850777924 申请日期 1985.09.19
申请人 GEIMUPLAST PETER MUNDT GMBH & CO. KG 发明人 FRUTH, RUPERT;STEMMER, GOTTFRIED;POHL, CLAUS
分类号 G03D15/00;G03B27/62;G03D15/10;(IPC1-7):G01N21/86;G03B1/00 主分类号 G03D15/00
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