A digital contour-corrector for a high-definition TV camera

NHK's high-definition TV system uses 1125 scanning lines, and is of high picture-quality. The output signal from the HDTV camera has a bandwidth of more than 30 MHz. Whether by analog or digital techniques, it is not easy to deal with such a wide band as this. In analog hardware, and ultrasonic delay-line is used for the 1H delay-line and it has such disadvantages as fluctuation in the delay-time, ghost images caused by spurious radiation and multiple reflections, and waveform distortion. Therefore, when using an analog wideband ultrasonic delay-line, it is very difficult to get a stable signal without distortion. But with digital techniques, an ideal delay-line is feasible, and a stable, accurate contour signal can be obtained.