. . "Like the first embodiment, encoding transmissions/receptions are performed by using an encoding set including two modulation codes A and B and a reverse encodingset including two modulation codes -B and -A. As shown in FIG. 12, (i) to (iii), and FIG. 13, (i) to (iii), the first to third encoding transmissions/receptions are performed on the Nth scan line." . .