| 摘要 |
PURPOSE:To realize an effective recording and reproducing system to a still picture requiring a high picture quality while improving the S/N of a low saturation part by emphasizing the low saturation part of a chrominance signal and applying phase modulation to a sub-carrier with the emphasized chrominance signal. CONSTITUTION:An output (756kHz corresponding to 48fH horizontal scanning frequencies) of an oscillator 1 is converted into three kinds of carriers by a phase shifter 2. A chrominance signal ER-Y(t) whose low saturation part is emphasized at a gamma circuit 40a is applied to a balanced modulator 3, a balanced modulating wave with -Asinomegact(carrier) applied from a phase shifter 2 is formed at the modulator 3. A chrominance carrier signal CR(t) is formed once by adding Acosomegact to this balanced modulating wave, the result is inputted to an inverting circuit 4, where + or -CR(t) is formed by controlling the phase inversion with a rectangular wave of 1/2fH. On the other hand, the other chrominance signal EB-Y(t) whose low saturation part is emphasized by a gamma circuit 40b and Acosomegact are inputted to a balanced modulator 5, and a chrominance carrier signal CB(t) is formed similarly. The signals CB(t) and + or -CR(t) are multiplexed by a synthesis circuit 6 and a recording chrominance signal C(t) is obtained.
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