DEFLECTION REFERENCE ADJUSTMENT FOR VARIABLE TRACK PITCH MEDIA

摘要

APPARATUS AND METHOD FOR GENERATING AN ANALOG WAVEFORM (232, 234, 236), SUCH AS A DEFLECTION SIGNAL (182) USED TO DEFLECT A WRITE BEAM (152) DURING THE WRITING OF DATA TO A ROTATABLE MEDIUM (102) HAVING A VARIABLE TRACK PITCH (TP). IN ACCORDANCE WITH VARIOUS EMBODIMENTS, A FIRST DIGITAL TO ANALOG CONVERTER (DAC) (212) IS CONFIGURED TO OUTPUT A DEFLECTION SIGNAL (218) HAVING AN ANALOG VOLTAGE LEVEL CORRESPONDING TO A MAGNITUDE OF A FIRST MULTI-BIT DIGITAL INPUT VALUE (214) APPLIED TO THE FIRST DAC. A SECOND DAC (220,222) IS CONFIGURED TO SUPPLY A RAIL VOLTAGE TO THE FIRST DAC HAVING AN ANALOG VOLTAGE LEVEL CORRESPONDING TO A MAGNITUDE OF A SECOND MULTI-BIT DIGITAL INPUT VALUE (224,228) APPLIED TO THE SECOND DAC. THE DEFLECTION SIGNAL IS USED TO DEFLECT A WRITE BEAM (152) SUPPLIED BY A WRITE BEAM GENERATOR (151).