To prevent a PD flexible print board from peeling from a main surface of an OPU circuit board.
A means for preventing the PD flexible print board 72 from peeling from the OPU circuit board 71 fixes the PD flexible print board 72 at least at three points on the main surface of the OPU circuit board 71. On the OPU circuit board 71, a reinforcing central land 713 for practically fixing the PD flexible print board 72 at the central part and a pair of reinforcing both-end lands for fixing the PD flexible print board 72 at the both ends of a plurality of wiring terminals. On the PD flexible print board 72, a central circular hole 723 set at the position corresponding to the reinforcing central land 713 and a pair of both-end connecting parts set on the positions corresponding to the pair of the reinforcing both-end lands are formed. The reinforcing central land 713 and the central circular hole 723, and the pair of the reinforcing both-end lands and the pair of the both-end connecting parts are fixed by soldering respectively.
OKUYAMA YOSHIHIRO
Shuichi Fukuda
Takashi Sasaki