Back to results
US 4,727,580 AGranted
Radio receiver
AssigneeAlpine Electronics, Inc.
InventorTsuneo Sakai
Life of this patent
Estimating the term…
Abstract
A radio receiver most suitable for use in a car includes a pulse count demodulating circuit and a second demodulating circuit other than a pulse count detecting circuit so that a demodulation signal from selected one of the demodulating circuits is supplied according to the level of a detection signal supplied from a received electric field intensity detecting circuit.
Claims4
A radio receiver for receiving a radio signal comprising:
- means receiving and converting said radio signal into an IF signal;
- a first demodulating circuit which is a pulse count demodulating circuit and a second demodulating circuit other than a pulse count demodulating circuit, both demodulating circuits being responsive to said IF signal;
- a detecting circuit for generating a field strength signal related to the received electric field intensity of said radio signal;
- and
- a switching circuit selectively outputting a demodulation signal from said first demodulating circuit and a demodulation signal from said second demodulating circuit in response to said field strength signal.
2 more elements
A radio receiver for receiving a radio signal comprising:
- means receiving and converting said radio signal into an IF signal;
- a first demodulating circuit which is a pulse count demodulating circuit and a second demodulating circuit other than a pulse count demodulation circuit, both demodulating circuits being responsive to said IF signal;
- a detecting circuit for generating a field strength signal related to the received electric field intensity of said radio signal;
- a switching circuit selectively supplying a demodulation signal from said first demodulating circuit and a demodulation signal from said second demodulating circuit in response to said field strength signal;
- a noise elimination circuit for removing noises contained in one of said demodulating signals supplied from said switching circuit;
- and
- a noise elimination circuit controller responsive to the received electric field intensity to change the degree of the noise eliminating operation of said noise elimination circuit.
4 more elements
A radio receiver for receiving a radio signal comprising:
- means receiving and converting said radio signal into an IF signal;
- a first demodulating circuit which is a pulse count demodulating circuit and a second demodulating circuit other than a pulse count demodulating circuit, both demodulating circuits being responsive to said IF signal;
- a detecting circuit for generating a field strength signal related to the received electric field intensity of said radio signal;
- a switching circuit selectively supplying a demodulation signal from said first demodulating circuit or a demodulation signal from said second demodulating circuit in response to said field strength signal;
- a stereo demodulation circuit receiving a stereo demodulation signal which is one of said demodulation signals supplied from said switching circuit, to reproduce an L-channel signal and an R-channel signal from said stereo demodulation signal;
- a separation circuit responsive to said field strength signal to control the degree of channel separation of said stereo demodulation circuit;
- a high-cut circuit responsive to said field strength signal to attenuate high band components of said L-channel signal and R-channel signal supplied from said stereo demodulation circuit;
- and
- a separation/high-cut controller interrupting or minimizing operations of said high-cut circuit and separation circuit when said stereo demodulation signal supplied from said switching circuit is said demodulation signal from said first demodulating circuit.
6 more elements
Dependencies are inferred from the claim text.