五、电视广播及其设备(二续) 5.同步信号发生器在实现电视过程中,首先必须使发送与接收端的扫描动作能保持一致,所以整个系统的扫描动作必须由同步信号严格地控制,这在“全电视信号”(见讲座二42页)一节中已有叙述.在一般简单的工业电视系统中,为了简化设备,降低成本,大都采用逐行扫描控制.只要在电视发送设备中(一般在摄象机中)直接利用自激式脉冲振荡电路来产生行扫描的触发脉冲,去控制 V. TV broadcasting and its equipment (2) 5. Synchronous signal generator in the realization of the television process, we must first send and receive the end of the scanning action can be consistent, so the entire system of scanning must be strictly controlled by the synchronization signal, This is described in the section titled “Full Television Signals” (see Lecture 2 on page 42). In simple industrial television systems, the progressive scan control is mostly used to simplify the equipment and to reduce the cost, (Usually in the camera) direct use of self-excited pulse oscillation circuit to generate line scan trigger pulse, to control