| 摘要 |
<p>PURPOSE:To prevent paper from becoming contaminated by providing a sensor consisting of a freely rotating detection lever and a sensor section which detects the rotary displacement of the lever on a pen holder and setting a rotating center shaft almost in parallel with an X direction. CONSTITUTION:A detection lever 36 is pivoted 38 on the main unit of a photosensor in freely rotatable manner. If the end of paper is detected, the photosensor determines whether a pen head 30 is present at a home position, unless a writing tool is held by a pen holder 32. If the result is 'YES', the detection lever 36 is allowed to descend over a specified distance, and the lower end of the lever 36 is placed on the upper surface of a platen 20 in a groove 42 to move the pen head 30 in a +Y direction. Then a controller determines whether the pen head 30 has moved beyond the lateral size of the paper 46. The lower end of the detection lever moves in the +Y direction along the groove 42, and if it hits the edge of the paper, the lever 36 rotates clockwise around a shaft 38, hence the edge is detected by the sensor.</p> |
