To realize an electronic chart display information device with a simple circuit wherein a highly precise chart image and a radar image can be quickly synthesized in specified priority.
A chart image plane 420 for storing a chart image, a radar image plane 430 for storing a radar image, a master plane 421 for storing a logical value in every picture element showing that either of the chart image and the radar image is shown by priority and an image composition circuit 450+460 for selectively outputting either one of a picture element value from the chart plane read in response to a display object picture element and another picture element value from the radar image plane as the value of the display object picture element in response to the logical value from the master plane are equipped.
KOYAMA TAKENOBU
BABA FUJIO
MISHIMA HIROAKI
