GENERATION FOR ORTHOGONAL SEEK SIGNAL FROM DISCONTINUOUS TIMEWISE TRACKING ERROR SIGNAL AND DISCONTINUOUS TIMEWISE RF DATA SIGNAL IN OPTICAL STORAGE DEVICE

PROBLEM TO BE SOLVED: To generate orthogonal signals from a discontinuous timewise TES signal and a discontinuous timewise RF baseband signal by detecting pulses being in the discontinuous timewise TES signal expressing the position of a light beam with respect to the center line of a track and the discontinuous timewise RF baseband signal and counting the number of tracks in which the light beam traverses in its seeking operation. SOLUTION: A discontinuous timewise TES signal 114 is selected by a MUX 100. On the other hand, a discontinuous timewise RF baseband signal 112 is extracted by an envelope detector 110. The discontinuous timewise TES signal 114 and the RF baseband signal 112 are synchronized by a synchronizer 118 according to a current seek speed and an operation mode and they pass through LPFs 116A, 116B and a track traversing frequency is extracted. Then, these signals are respectively converted into binary square-wave signals TEX 128 and REX 130 by a TEX detector 132 and a REX detector 134 to form orthogonal seek signals.