公开(公告)号：US3872497A

公开(公告)日：1975-03-18

申请号：US35103673

申请日：1973-04-13

Applicant: RCA CORP

Inventor： AMERY JOHN GORDON ,  JORGENSON ROBERT WARREN

IPC: H04N9/64 ,  H04N9/78 ,  H04N9/85 ,  H04N9/12

CPC classification number: H04N9/85 ,  H04N9/646 ,  H04N9/78

Abstract: Circuits are disclosed for processing color encoded video signals, encoded per a format wherein a chrominance signal in the form of a modulated subcarrier is buried in spectrum ''''troughs'''' in the midband of a wider band luminance signal, an illustrative use of the encoding format being in video disc recording. The processing circuits serve, in use with composite signals developed during video disc playback, to convert an input composite signal of buried subcarrier format to an output composite signal of NTSC format. Comb filtering is employed to separate buried subcarrier chrominance signal from midband luminance signal components. A heterodyning step preceding comb filtering is performed in a manner substantially precluding ''''jitter'''' of played back signals from disturbing accuracy of comb filter separating action, enabling use of a single 1H delay line form for the comb filter and enabling use of a relatively inexpensive, narrowband structure for the single delay line. The comb filter output provides a chrominance signal in a band suitable for output composite signal use. The output chrominance signal is also used in a subtractive process to effect comb filtering of the luminance signal to remove therefrom midband chrominance signals.

Abstract translation: 公开了用于处理彩色编码视频信号的电路，按照格式编码，其中调制副载波形式的色度信号被掩埋在较宽频带亮度信号的中间频带的频谱“波谷”中，编码格式的说明性使用 在视频光盘录制。 处理电路与视频盘播放期间开发的复合信号一起使用，将埋入的子载波格式的输入复合信号转换为NTSC格式的输出复合信号。 采用梳状滤波将掩埋的副载波色度信号与中频带亮度信号分量进行分离。 以梳状滤波器分离动作的干扰精度基本排除回放信号的“抖动”的方式进行梳状滤波前的外差步骤，使得能够使用单个1H延迟线形式用于梳状滤波器，并且能够使用相对便宜的， 单一延迟线的窄带结构。 梳状滤波器输出在适合于输出复合信号使用的频带中提供色度信号。 输出色度信号也用于减法处理以对亮度信号进行梳状滤波以从中间带色度信号中去除。