| 摘要 |
PURPOSE:To obtain a lock detection apparatus which can detect a synchronous lock state surely even when a slight phase deviation is generated by the rotation irregularity of a motor or the like by a method wherein, when a phase-difference polar signal is not changed so as to exceed a preset prescribed value, a command pulse and a feedback pulse are judged to have been locked. CONSTITUTION:In a pulse-lock detection circuit 3, a PLL-lock state is judged on the basis of a phase-difference pulse Pd from a PLL control part 122. In addition, in an analog-lock detection circuit 4, the PLL-lock state is judged on the basis of a phase-difference polar signal S21 which has integrated a phase- difference polar pulse Pepsilon from the PLL control part 122. When the PLL-lock state is detected in either the pulse-lock detection circuit 3 or the analog-lock detection circuit 4, a command pulse CK and a feedback pulse FG are regarded as the PLL-lock state. |
