Patent ID: 6115105
Filing Date: 2000-09-05
Classification: G03B

Abstract:
A microfilm search device for searching a desired frame from a microfilm by detecting the presence of frames from a density change in the running direction of the microfilm, comprising:a) an encoder for outputting a sampling signal for a predetermined feeding amount of the microfilm;b) a pair of optical fibers whose end faces are opposed to each other while the microfilm is placed between the end faces within a frame travel width;c) a light source for guiding light to one of said optical fibers;d) a photosensor for detecting a quantity of light incident on the other optical fiber to output a density signal;e) a binarizing section for binarizing the density signal into a white or black signal in synchronization with said sampling signal, the white signal representing a film transparent portion and the black signal representing a film non-transparent portion;f) a determination section for detecting a frame dimension or a dimension between frames based on the binarized density signal and comparing the dimension with a set value to determine the presence of frames and output a determination signal; andg) a searching section for searching for the desired frame based on said determination signal;wherein, when the frame dimension or the dimension between frames is detected from the length of a portion where the white signals are continuously obtained, said set value is set longer than an actual frame dimension or an actual dimension between frames; andwherein, when the frame dimension or the dimension between frames is detected from the length of a portion where the black signals are continuously obtained, said set value is set shorter than the actual frame dimension or the actual dimension between frames.