Patent ID: 6903798

Claim:
A pattern writing apparatus for writing a pattern by applying light to a photosensitive material, comprising: a light irradiating part for applying modulated light to each of irradiation regions of an irradiation region group which are arranged at equal pitches in two directions perpendicular to each other on a photosensitive material; a scanning mechanism for scanning said irradiation region group over a photosensitive material in a scanning direction which is tilted relative to a direction of arrangement of said irradiation region group, and causing a plurality of irradiation regions to move relative to writing regions of a writing region group, respectively, said writing regions being fixedly arranged in said scanning direction and a direction perpendicular to said scanning direction at equal writing pitches on said photosensitive material; and a controller controlling an amount of light applied to each of said writing regions on a photosensitive material by exercising individual ON/OFF control of light irradiation of said irradiation region group in synchronization with scanning of said irradiation region group, wherein a center-to-center distance along said direction perpendicular to said scanning direction between adjacent irradiation regions arranged in a direction extending approximately along said scanning direction out of said two directions in which said irradiation regions are arranged is equal to said writing pitch, a center-to-center distance along said scanning direction between said adjacent irradiation regions is equal to “a times” said writing pitch (a is an integer equal to or larger than 2), said controller exercises ON/OFF control of said light irradiation once during relative movement of said irradiation region group by a distance equal to “n times” said writing pitch (n is an integer equal to or larger than 2), and (a 2 +1) and n are relatively prime.