发明名称 |
Television receiver including a circuit arrangement for demodulating an NTSC-coded color signal |
摘要 |
A color television signal receiver includes a circuit arrangement for demodulating an NTSC-encoded chrominance signal available as a sequence of digital values. An oscillator circuit (33), which has an accumulator (16) and a waveform converter (31) produces two sine-shaped reference signals which are applied to a demodulator circuit (2). The accumulator (16) includes a register (18) and a (first) modulo-adder (17). A phase comparator circuit (12) controlling the phase of the reference signal receives at least one demodulated signal during the occurrence of the color synchronizing signal. The sawtooth-shaped accumulator output signal is added in a second adder (26, 38) during a first switching position of a change-over switch (23, 34) to an adjustable value and is thereafter applied to the waveform converter (31). In the second switching position of the change-over switch (23, 34), which only occurs during the occurrence of the color synchronizing signal, the accumulator output signal is applied unchanged to the waveform converter (31).
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申请公布号 |
US4710802(A) |
申请公布日期 |
1987.12.01 |
申请号 |
US19860836034 |
申请日期 |
1986.03.04 |
申请人 |
U.S. PHILIPS CORPORATION |
发明人 |
WARMUTH, OTTO L.;JOHANNDEITER, MARTIN H.;RAVEN, JOHANNES G. |
分类号 |
H04N9/45;H04N9/44;H04N9/64;H04N9/66;H04N11/14;(IPC1-7):H04N9/66 |
主分类号 |
H04N9/45 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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