A hybrid output driver includes a voltage mode main driver having an adjustable differential output voltage swing, and a current mode emphasis driver. The medical fluid nozzle 1 is a substantially cylindrical shape with a tip surface formed in a substantially planar shape. The heater element has a cross section with a lateral dimension at least triple that of the thickness of heater element. The image processing apparatus acquires projection parameters indicating the relationship between the image of the whiteboard and the real whiteboard from vertex positions of the quadrangle, and performs projection transformation of the image of the whiteboard. The block is securely retained within the recess.