| 摘要 |
An a-d converter(21) digitizes the baseband video, which is fed to a formatter(27) that removes sync. signals comprising the video, and formats it into 4-bit code blocks. Alternate output pulses are produced with discretely variable time durations, corresp. to the particular code blocks fed to the modulators. These output pulses are fed to a combiner(39) to produce an output for the laser intensity modulator (17). The combiner also controls the timing of the 'mark' and 'space' modulators by enabling one immediately after the other's output pulse has ended. The modulate beam from the laser(13) is directed onto the disc(11).
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