| 摘要 |
APPARATUS FOR DETECTING THE PASSAGE OF MULTIPLE SUPERPOSED SHEETS ALONG A FEED PATH A linear variable differential transformer (42) produces an output voltage which varies linearly with movement of the axis of a movable axis roller (14) relative to the axis of a fixed axis roller (12) brought about by the passage of a sheet between the rollers. Circuits (154, 189) store a reference voltage representative of a minimum value of said output voltage during one revolution of the fixed axis roller, and subtracting circuits (162, 172) subtract the reference voltage from said output voltage when a single or multiple sheet is passing between the rollers so as to produce a difference value representative of the thickness of this sheet. A processor (178) samples the difference value a plurality of times during one revolution of the fixed axis roller, and provides an indication that a multiple sheet has passed between the rollers if at least a predetermined number of consecutive samples of said difference value exceed a predetermined value. |
