PURPOSE: To decide the unstable state of pencil lead accurately and easily by measuring the position of the specified point of a pencil-lead displacement mechanism at the location of a pen holder immediately before the position of knock.
CONSTITUTION: A pencil pen 1 is elevated up to a position immediately before knocking by a pen holder 225, and the location of the specified point of a pencil- lead displacement mechanism 13 at that time is measured by a position sensor 4 while using the location of a base 221 as a reference, thus deciding the unstable state of pencil lead 15. Accordingly, slipping-off from a lead chuck member 12 of the pencil lead 15 can be detected, thus accurately determining the unstable state of the pencil lead 15 easily.
KIMURA SHOICHI
SUGIMOTO TAKASHI
