Patent ID: 6069667
Filing Date: 2000-05-30
Classification: H04N

Abstract:
A synchronizing signal detection device comprising:(a) pattern check means for checking a signal pattern of a synchronizing (Sync) signal included in television signals transmitted in digital mode with a predetermined reference pattern, and outputting a check result as an output signal,(b) agreement detection count means for receiving the output from said pattern check means, counting a value of agreement cases where the reference pattern agrees with the pattern of Sync signal, and outputting information of counted values as an output signal,(c) disagreement detection count means for receiving the output signal from said pattern check means, counting a value of disagreement cases where the reference pattern disagrees with the pattern of Sync signal, and outputting information of counted values as an output signal,(d) Sync detection determination means for determining a detection of said Sync signal based on the output signals from said agreement detection count means and said disagreement detection count means, and outputting information whether the Sync signal is detected or not,(e) Sync count means for counting a value of symbols which correspond to cycles of said Sync signal in response to the output signals from said Sync detection determination means and from said pattern check means, outputting a timing signal when the counted value reaches to a predetermined value,wherein, said Sync signal detection device further comprises Sync detection initialization means having such functions as:receiving a switch-over signal at an input terminal, said switch-over signal indicating that an input signal to be received is switched,coupling an output terminal to said agreement detection count means with said disagreement detection count means,resetting forcibly the counted value of said agreement detection count means when said switch-over signal is given, andsetting forcibly the counted value of said disagreement detection count means at a predetermined value.