| 摘要 |
PURPOSE: An apparatus for triggering a video signal is provided to apply trigger pulses to a high-speed data acquisition system or data acquisition board which have no trigger function, and to display signals generated from each electronic apparatus for analysis. CONSTITUTION: An apparatus comprises a multiplexing block(10), a separation block(12), a logic portion(14), a main counter(20), a sub counter(18) and a generation block(16). The multiplexing block(10) selects one input of video signals from many input terminals. The separation block(12) separates various synchronization signals from a composite video signal. The logic portion(14) generates timing signals for controlling counters(20, 18) according to the synchronization signals from the separation block(12). The main counter(20) divides a horizontal period by clock pulses, so that a trigger pulse are generated during special time. The sub counter(18) counts the horizontal period, selects a special line, and generates a trigger pulse according to condition. The generation block(16) generates various pulses according to information of the sub counter(18) and logic portion(14). |
