PURPOSE: To prevent the flying of the pen at the time of the high speed operation of the pen by providing a mechanism, wherein a frictional force is yielded by the upward movement of the pen which is attached to a pen holder, between the pen holder and a slider.

CONSTITUTION: Even though the pen 18 receives the upward rising force at the time of the high speed running, since a sliding part 16a at the tip of a plate spring 16 is compressed to the side surface of a supporting tool 14a, a force which prevents it is acted by the static frictional force between both parts. Said frictional force is not applied when the pen 18 is running normally, and the friction between the tip of the pen 18 and paper is not increased.