| 摘要 |
<p>Holder for a stack of sheets, which sheets (2), in successive cycles, can be fed from the holder (40) from the bottom of the stack, and returned to the top of the stack or, in the last cycle, discharged to a tray (46). The holder (40) comprises a separating means (15, 49) which can be engaged between sheets (2) of the stack for separating returned sheets from the other sheets of the stack. A detection system (12, 13; 41) is provided for detecting that sheets have been placed in the holder (40) (for starting a first cycle) and for detecting that all the sheets have been returned to the holder (40) (for starting a next cycle).
<??>The detection system (12, 13; 41) comprises a light source (12) and a light-sensitive detector (13) installed at the bottom of the stack. When by the feeding of sheets the separating means (15, 49) reaches the bottom of the stack, the separating means (15, 49) intercepts the light from the light source (12), which results in a reaction of the detector (13), which reaction is similar to the reaction of the detector (13) with an empty holder, but which reaction differs from the reaction of the detector (13) when a sheet intercepts the light. </p> |
