We have been developing a pulse-driven Josephson voltage standard in order to establish a quantized AC voltage standard at AIST. As the first step toward this goal, we have performed an experiment of operating an overdamped Josephson junction array by current pulse trains generated by triggering a photo detector located in a cryostat with an optical comb. Quantized voltage steps have been verified at a multiple of 10µV, which agrees with the repetition rate of the pulse laser and the number of Josephson junctions in the array.