Patent ID: 6062454
Filing Date: 2000-05-16
Classification: B25C,B27F,B42C,B65H,G03G

Abstract:
A sheet binding apparatus for effecting a stapling operation in which a needle is pressed into a sheet stack by moving a head by operation of a motor, comprising:first timing output means for outputting a signal at a timing of a needle pressing operation;second timing output means for outputting a signal at a timing other than the timing of the needle pressing operation;electrical load measuring means for measuring an electrical load value on the motor when the head moves, in response to the signals from said first and second timing output means;base value setting means for setting an electrical load base value on which a judgement of the presence and absence of the needle is based; andjudging means for calculating a difference value between electrical load values measured by the electrical load measuring means in response to signals from said first and second timing output means and for comparing the difference value with the value set by said base value setting means to judge the presence and absence of the needle.