DIGITAL MAGNETIC RECORDER AND REPRODUCER OF TELEVISION SIGNAL

摘要

PURPOSE:To obtain a digital magnetic recorder and reproducer of a television signal with less deterioration in picture quality by sampling a television signal with a frequency which is lower than the double value of a frequency band and Hadamard-transforming the sampled television signal. CONSTITUTION:A color television signal inputted into an input terminal 501 is sampled by an AD converter 502 at a frequency of 4fsc (color subcarrier), and then, re-sampled at a sub-sampler 503 at another frequency of 2fsc. The re- sampled output is sent out to a transmission line 506 through a Hadamard transformer 504 and quantizer 505. Then the output is returned to the original 8-bit input value string by means of a reverse quantizer 507 and Hadamard reverse transformer 508. The output of the Hadamard reverse transformer 508 is supplied to an adder 512 through a field memory 509 and digital filter composed of a BPF510 and LPF511, and a supplemental composite signal is obtained. When the supplemental composite signal and a transmitted signal are passed after switching them with the frequency of 2fsc, it is apparently observed that the sample point of the frequency of the 4fsc is transmitted.