A scanning control circuit generates a clock signal corresponding to an
expected scan timing of a resonant scanner. In one approach, the control
circuit uses a pair of direct digital synthesis (DDS) integrated
circuits. A first DDS chip provides a system clock that is synchronized
to the monitored period of the scanner. A second DDS chip generates a
frequency chirped signal that has a frequency profile corresponding to a
desired pixel clock timing. To control phase precisely, four
complementary clock signals are weighted and mixed at light source
drivers to produce relative phase shifts for different light sources.