| 摘要 |
<p>PURPOSE: To set a reference to a video frame by providing a microprocessor for operating responding to a phase-locked clock signal to the synchronizing signal component of a synthesized video signal. CONSTITUTION: By energizing a device, the microprocessor 30 is energized by the clock signal pulled out from a phase locked loop, and integer number pieces of one cycle commands are executed for one television horizontal line period. If a signal line period of white-and-black or other than standard different in duration comes in, the phase locked loop 20 adjusts a clock frequency to keep executing the integer number pieces of commands at each interval of line period, however, this command is executed in a certain phase relation to the start point of each random line at first. At this time, the microprocessor samples the synthesized synchronizing signal and executes a clock skip method to synchronize the phase of a command cycle with the video signal, so that a reference of each horizontal line is set. Thus, the microprocessor 30 counts the pulse of a horizontal frequency, and any specified line or the linear part of the video signal is recognized.</p> |
