Mitsubishi Denki Kabushiki Kaisha

Miyoichi Watanabe

Tomonori Ohashi

Toshihiro Gai

Shinobu Ueda

In a YC separating filter, a first horizontal chrominance extraction filter extracts frequency components corresponding to components of a color subcarrier in a horizontal direction to produce a first chrominance signal, a vertical chrominance extraction filter extracts frequency components corresponding to components of a color subcarrier in a vertical direction to produce a second chrominance signal, a horizontal and vertical chrominance extraction filter extracts frequency components corresponding to components of a color subcarrier in horizontal and vertical directions to produce a third chrominance signal, a first selector selects one of the first, second and third chrominance signals, a second horizontal chrominance extraction filter having a narrower bandwidth than the first horizontal chrominance extraction filter is provided to receive the selected chrominance signal, and a second selector selects the output of the second horizontal chrominance extraction filter when the first selector selects either the first or third chrominance signal, and selects the output of the first selector when the first selector selects the second chrominance signal.

Luminance/chrominance separating filter

In an amplifier circuit, there are provided a preamplifier, a first differential-input amplifier and a second differential-input amplifier. An AC negative feedback path is formed between the output terminal of the preamplifier and the inverting input terminal thereof. The inverting input terminal is connected to a ground via a RC series circuit. An input signal containing a DC voltage component is supplied via the junction of the RC series circuit to the inverting input terminal. A voltage appearing at this junction is applied to both the first and second differential-input amplifiers as a reference voltage.

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Nagaokakyo, Japan

Miyoichi Watanabe