PURPOSE: To enhance speeds in processing for an exposure data processing circuit by controlling a virtual and a physical area based on the first external control data D1, thereby controlling a data processing device, and a data transfer and a digital control device based on the second external control data D2.

CONSTITUTION: A virtual and a physical area conversion circuit 16 are controlled based on the first external control data D1 so that the output of write area designation data SWD which indicates the data designation of auxiliary deflection processing data SMD from the housed data of main deflection exposure data MDout is thereby controlled by the circuit 16. In the second place, a data work processing circuit 13 and a data transfer digital control circuit are controlled based on the second external control data D2 so that deflection work data SMD is processed while being synchronized with write control data. Successively, when read-out a write and a read-out control circuit 11 and 14 are controlled via a control circuit 18, data housed in a main deflection data memory circuit 12 and data housed in an auxiliary deflection data memory circuit 15 can be read out as the hardware does. Thus, speeds in processing for the exposure data processing circuit can be enhanced.