PURPOSE: To obtain a sharp picture by arranging a reading optical system on a board on which a picture is drawn and scanning this optical system.

CONSTITUTION: A case 3 is hung onto a board 1 such as blackboard by rollers 5a, 5b. The inside of the case 3 is provided with a reading optical system consisting of lamps 6a, 6b for exposure and a solid-state image pickup element 8. In lighting the lamps 6a, 6b and driving a driving motor 16, the case 3 and the reading optical system of the case 3 are subscanned on the board 1. A picture on the board 1 is projected to the element 8 during the subscanning. The main scanning of the element 8 is performed by a driving circuit.