| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a ruler allowing a user to draw a circle by an easy operation without making a paper dirt by using a compass together, and always safely usable.SOLUTION: A ruler has a function of arbitrarily setting an interval between a compass needle and a writing instrument core. The ruler 100 includes: a ruler body 110 having a graduation part 111 provided along at least one long side, a compass needle insertion hole 115 provided on a position corresponding to the original point of the graduation part 111, and a guide structure 112 provided along the graduation part 111; and a movable plate 120 as a movable plate movable along the guide structure 112, having a pointer 124 pointing any part of the graduation part 111 in order to read its own position along the graduation part 111 when moving along the guide structure 112, and a compass writing instrument core insertion hole 123 provided on a position corresponding to a part pointed by the pointer 124.</p> |
