Noise reduction apparatus in an FM stereo tuner
First Claim
1. A noise reduction apparatus in an FM stereo tuner comprising:
- a circuit for generating a stereo sum signal and a first stereo differential signal;
a noise eliminating circuit for dividing said stereo sum signal and said first stereo differential signal, in accordance with a plurality of frequency bands, into a plurality of divisional differential signals and a plurality of divisional sum signals, for eliminating a low-level divisional stereo differential signal in each of said plurality of frequency bands so as to output a second differential signal representing those first differential signals not eliminated, and for outputting a composite signal representing the second stereo differential signal and only those divisional stereo sum signals in the same divisional band as said eliminated divisional stereo differential signals; and
a circuit for reproducing a stereo signal from said composite signal and said stereo sum signal.
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Accused Products
Abstract
A noise reduction apparatus in an FM stereo tuner including a circuit for generating a stereo sum signal and a stereo differential signal; a noise eliminating circuit for dividing, in accordance with several frequency bands, the stereo differential signal into several divisional signals and for outputting, in accordance with signals levels corresponding to the frequency bands, a composite signal of divisional stereo differential signals respectively corresponding to the signal levels; and a circuit for reproducing a stereo signal from the composite signal and the stereo sum signal. In another embodiment, the noise reduction apparatus includes a circuit for generating a stereo sum signal and a first stereo differential signal; a noise eliminating circuit for dividing the stereo sum signal and the first stereo differential signal into several division differential signals and several divisional sum signals, for eliminating a low-level divisional stereo differential signal in each of the frequency bands to generate a second stereo differential signal, and for outputting a composite signal representing the second stereo differential signal and those divisional stereo sum signals in the same divisional band as the eliminated divisional stereo differential signals; and a circuit for reproducing a stereo signal from the composite signal and the stereo sum signal.
39 Citations
9 Claims
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1. A noise reduction apparatus in an FM stereo tuner comprising:
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a circuit for generating a stereo sum signal and a first stereo differential signal; a noise eliminating circuit for dividing said stereo sum signal and said first stereo differential signal, in accordance with a plurality of frequency bands, into a plurality of divisional differential signals and a plurality of divisional sum signals, for eliminating a low-level divisional stereo differential signal in each of said plurality of frequency bands so as to output a second differential signal representing those first differential signals not eliminated, and for outputting a composite signal representing the second stereo differential signal and only those divisional stereo sum signals in the same divisional band as said eliminated divisional stereo differential signals; and a circuit for reproducing a stereo signal from said composite signal and said stereo sum signal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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Specification