| 摘要 |
<P>PROBLEM TO BE SOLVED: To enhance not only the kind discrimination precision of a sheet "such as pulp paper or the like but also discrimination precision in the case of many kinds. <P>SOLUTION: The kind discrimination device of the sheet comprises a light emitting element LED; a photodetector PTr which traverses a sheet passing gap to detect the light projected by the LED; the load resistor 55 connected to the PTr to output an electric signal Vpd of which the level corresponds to the light detecting level of the PTr; quantity-of light adjusting means 43 and 131 for adjusting the emission of the LED during the absence of the sheet so that the Vpd becomes a target value Vm to stop the adjustment during the during the absence of the sheet; VPd range setting means 56 and 57/53a and 58; and encoding means 44, 45 and 131 for holding Vpd to a first range when Vpd is switch threshold value Vt2 or above in the case of the presence of the sheet in the first range of low Vpd level and switching Vpd to a second range of high Vpd level when Vpd is below Vt2 to convert the Vpd level to the data (kind section No.) corresponding to the kind of the sheet. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
