Patent ID: 8991820
Filing Date: 2015-03-31
Classification: B65H

Abstract:
1. A paper conveying apparatus comprising: a sound signal generator, provided with a sound detector near a conveyance path of a paper, for generating a sound signal corresponding to a sound generated by the paper during conveyance of the paper; a frequency signal generator for generating a frequency signal by converting the sound signal to frequency; and a sound jam detector for determining whether a jam has occurred, based on a sum of differences of values of frequency components of the frequency signal and values of adjoining frequency components which respectively adjoin the frequency components, or based on a difference of a maximum value of the frequency signal and a minimum value of the frequency signal, or based on a difference of a value of the frequency signal at a predetermined frequency and an average value of the frequency signal or a difference of a value of the frequency signal at a predetermined frequency and a minimum value of the frequency signal, or based on a ratio of a first average value of the frequency signal at a first frequency band and a second average value of the frequency signal at a second frequency band which has a minimum frequency the same as a minimum frequency of the first frequency band and which has a maximum frequency higher than a maximum frequency of the first frequency band, or based on a ratio of a third average value of the frequency signal at a third frequency band and a fourth average value of the frequency signal at a fourth frequency band higher than the third frequency band.