PURPOSE: To continuously plot an arc track with different types of line segments so that joints of the track precisely correspond with each other by displaying coordinate values, track width, etc., plotting a continuously surrounding curve according to instructions read out of storage parts and thereby forming the arc track on a photosensitive material.
CONSTITUTION: An arc mode is selected through the operation of a console panel, and coordinates of an arbitrary start point A, end point B and passing point C on an arc R1 inner than a desired arc track are input to a CPU. Simultaneously, a track width W is input to the CPU. Based on the coordinate values of the points A, B and C, coordinate values of the curvature midpoint P1 of the inner arc R1 are calculated and stored. Consecutively, arc angles θ1 and θ2 and the curvature radium r1 of the inner arc R1 are calculated on the basis of data on coordinates of a line segment connecting the start and end points A and B and the curvature midpoint P1, and then the curvature radium r2 of an arc R2 outer than the arc track is calculated and stored. Moreover, coordinate values of the curvature midpoint P2 of a semicircular arc R3 joining the inner and outer arcs R1 and R2 are calculated and stored. Ultimately, the continuous arc track is displayed on a display part based on each parameter of the arc track.
KAWACHI HIROMI
MIYAMAE KAZUYA
SUZUKI KAORU
