DEVICE AND METHOD FOR DETECTING PHASE WITHOUT INSTANTANEOUS BREAKING AND DEVICE FOR CHANGING-OVER PHASE WITHOUT INSTANTANEOUS BREAKING

摘要

PROBLEM TO BE SOLVED: To save power consumption, to reduce a cost and to attain miniaturization by detecting a phase without instantaneous breaking without using a memory. ;SOLUTION: Phase difference detecting windows 30 and 31 are generated by a zero-system window generating circuit A200 and a one-system window generating circuit B201 on the basis of frame pulses 20 and 21 which are transmitted from multi-frame head detecting circuits 100 and 101. The windows are delayed for the portion of movement which is set by the phases of the frame pulses 20 and 21 transmitted from the multi-frame head position detecting circuits 100 and 101 so as to be generated. In a reference phase detecting circuit 300, a position where the windows are superimposed is detected and the position is outputted as the phase without instantaneous breaking 50 by the use of the zero-system window 30 and the one-system window 31 which are generated on the basis of setting. Then, a window comparing circuit which inputs the zero-system window 30 and the one-system window 31 so as to execute comparison detects the superimposition and non-superimposition of the windows.;COPYRIGHT: (C)1997,JPO