Patent ID: 6094542
Filing Date: 2000-07-25
Classification: G03B,G11B

Abstract:
A film feeding device which, when a film cartridge including a partially exposed film is loaded, detects an unexposed frame while feeding the film, said device comprising:film feeding means for feeding the film from the film cartridge, said film having magnetic recording portions each adjacent to a corresponding photographing frame in a longitudinal direction thereof and non-magnetic recording portions defined between the magnetic recording portions;readout means having a magnetic head, for reading out data that is magnetically recorded on the film and outputting a reproduction signal;position detecting means for detecting perforations of the film and determining whether the magnetic head is positioned on a magnetic recording portion or a non-magnetic recording portion;setting means for setting a threshold value based on the reproduction signal output from the readout means when the position detecting means determines that the magnetic head is positioned on the non-magnetic recording portion;frame determining means for comparing the reproduction signal output from the readout means with the threshold value when the position detecting means determines that the magnetic head is positioned on the magnetic recording portion and thereby determining whether a frame is exposed or unexposed; andnoise detecting means for detecting a noise in the reproduction signal output from the readout means when the position detecting means determines that the magnetic head is positioned on the non-magnetic recording portion.