When color TV became available, it had to be backward-compatible with B/W systems, so the color burst information was added on top of the existing luminance signal, as shown in Figure 3.

• 当彩色电视出现后，它必须保证与黑白电视的后向兼容，因此彩色脉冲信息被添加到已有的亮度信号顶部，如图3所示。