While scanning two laser beams that are separated by a prescribed distance d in the scanning direction, one of the beams is first irradiated onto a BD sensor at a timing t11. The spindle is formed from conventional steel rod stock and is machined to produce an upper end of reduced diameter. The exhaust muffler is attached to the two cross members via rubber supports. The write driver inputs write data and outputs a corresponding writing current to a write head to store information onto a magnetic disk. The combined applique elements can then be attached to the desired base material in a usual manner. Finally, decode the data frame by using an adaptive Viterbi algorithm on an extended trellis diagram.