论文部分内容阅读
在电视信号处理系统和电视信号测量仪器中,除了要分离出行、场同步信号作为时间基准外,往往还需要分离出帧同步信号,譬如在选行示波器中,用它作为行计数器的基准等。电视复合同步信号波形如图1所示。就场同步信号本身而言,奇偶场的情况是一样的。但是在奇数场的场消隐期间,第一个均衡脉冲和最后一个均衡脉冲分别与相邻的一个行同步脉冲间隔半个行频,而在偶数场的场消隐期间,第一个均衡脉冲及最后一个均衡脉冲分别与相邻的一个行同步脉冲相差一个行周期。两者不同的原因是由于奇数场的场同步信号起始沿与行同步的起始沿在时间上是一致的。由于一场等于312.5行,所以偶数场的场同步起始沿就落在两行的中间了。由此可见,只要从复合同步信号中精
In television signal processing systems and television signal measuring instruments, in addition to separation of travel, field synchronization signal as a time reference, often also need to separate the frame synchronization signal, such as in the election line oscilloscope, use it as a line counter benchmark. TV composite synchronization signal waveform shown in Figure 1. In terms of the field sync signal itself, the same is true for the odd and even fields. However, during the vertical blanking interval of the odd field, the first and last equalizing pulses are each separated by half a horizontal line frequency from the adjacent one of the horizontal synchronizing pulses, whereas during the vertical blanking interval of the even field, the first equalizing pulse And the last equalizing pulse is respectively separated by one line period from the adjacent one line synchronizing pulse. The reason for the difference between them is that the starting edge of the field sync signal in the odd field coincides with the start edge of the line sync in time. Since one field is equal to 312.5 lines, field start edges of even fields fall in the middle of two lines. This shows that as long as the signal from the complex synchronization