HORIZONTAL SYNCHRONIZATION FOR DIGITAL TELEVISION RECEIVER

摘要

A HORIZONTAL SYNCHRONIZING SYSTEM, COMPRISING: A SOURCE OF A HORIZONTAL SYNCHRONIZING SIGNAL; A SOURCE OF FIRST AND SECOND HIGHER FREQUENCY HORIZONTAL DRIVE SIGNALS; A PHASE DETECTOR (14) FOR GENERATING A FIRST CONTROL VOLTAGE RESPONSIVE TO THE HORIZONTAL SYNCHRONIZING SIGNAL (1 FF1 INPUT) AND THE FIRST HORIZONTAL DRIVE SIGNAL; A SOURCE OF A SECOND CONTROL SIGNAL (25); AND, A SWITCH FOR SELECTIVELY SUPPLYING THE FIRST CONTROL SIGNAL (17) TO THE SOURCE OF THE DRIVE SIGNALS FOR A PHASE-LOCKED MODE OF OPERATION AT THE FIRST HIGHER FREQUENCY AND SUPPLYING THE SECOND CONTROL SIGNAL TO THE SOURCE OF THE DRIVE SIGNALS FOR A PHASEEUNLOCKED MODE OF OPERATION AT THE SECOND HIGHER FREQUENCY.