| 摘要 |
<p>PURPOSE: To provide a device and method used together with the indicating instrument. CONSTITUTION: On some kind of data input and sign confirmation device, writing to the surface 14 having lines 15 is done by using a pen 12. An optical sensor 11 detects a line being crossed and a pen output signal is led out, so that the inputted data or sign can be discriminated or recognized. Although a threshold value is used to discriminate a bottom part of the output signal when the line is crossed, the general level (corresponding to the intervals between lines) between the bottom part and peak part varies and it becomes difficult to fix the threshold value level with the direction of the pen. A peak detector is used which gives a threshold value level that varies owing to variation of the pen output caused by the direction of the pen, but does not vary greatly when the line on the surface is crossed at an ordinary write speed. Further, another threshold value which generates a signal indicating whether or not the pen is in contact with the surface is also used.</p> |
