TRACING METHOD AND APPARATUS

摘要

In a tracing method in which tracing is performed by moving a plurality of tracing heads, each including a spatial optical modulation device and an optics system, in a predetermined direction relative to a tracing surface, changes in the relative positional relationship of the tracing heads arising from changes in the environmental temperature are minimized. A plurality of spatial optical modulation devices 34a, 34b are provided in a single tracing head 30, and the light modulated by the plurality of spatial optical modulation devices 34a, 34b is focused on a tracing surface 12a using common optics systems 36, 37 and 38 to reduce the number of the heads 30.