To reduce interconnections and miniaturize a circuit board.

A stroboscopic board, which is built in a lens-bearing film unit, is provided with a boosting transformer. Bobbins 58 of the boosting transformer, respectively have circuit patterns 59 on surface thereof. The circuit patterns 59 are connected to each of terminals a-d and f of the bobbins 58 with such a pattern form that individual electronic parts 46, 71 and 72 are electrically connected between the terminals a-d and f.