Digital Processing Amplifier and Color Encoder

Yoshizumi Eto, Kazuyuki Matsui, Shizuka Ishibashi, Hiroyuki Terui

Digital television equipment is expected to provide higher stability and accuracy than conventional analog equipment. A new method for digitizing a processing amplifier and color encoder is proposed and developed experimentally. In color television systems, stability and accuracy are required mainly for the low-frequency component of the television signal on which color fidelity depends. With this new method, only low-frequency components of preamplifier output signals are digitized, processed, encoded and converted by an digital-to-analog converter into an NTSC signal. High-frequency components of the preamplifier output signals are mixed by an analog method and converted to the high-frequency component of a luminance signal. This signal is added directly to the digitally encoded signal to obtain a full NTSC signal. All necessary circuits including A/D and D/A converters have been experimentally implemented and provide almost the same picture quality as a PCM-encoded composite NTSC signal.

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Published
1978-01
Content type
Original Research
DOI
10.5594/J17456