EP0459383A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Radio receiver
Assignee: Pioneer Corp
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Filing: 1991-05-28
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Granted: —
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Expires: 2011-05-28
Abstract
Abstract A radio receiver comprises a wide filter and a narrow filter, each of which is connected with the front end (2) and outputs an intermediate frequency signal. To the output of the filters (3a1,3a2) are connected a first and second detectors (3b1,3b2), respectively. A subtracter (3c) receives the outputs of the detectors and subtracts one from the other. A switch (3e) receives the output of the subtracter and directs the outputs of detectors in such a way that the switch is switched to a first position for directing the demodulated output from the first detector to a following circuit when the difference is below a reference level, and to a second position for directing the demodulated output from the second detector to the following circuit when the difference is above the reference level.
Inventors
- 👤 Toshihito C/O Pioneer Electronic Corp. Ichikawa
- 👤 Koichi C/O Pioneer Electronic Corp. Kasa
- 👤 Kiichiro c/o Pioneer Electronic Corp. Akiyama
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-30 14:35
CPC Classifications
H; H04; H04B; H04B1/00; H04B1/06; H04B1/10; H04B1/1027; H04B1/12; H04B2001/1054
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
131 words
A radio receiver comprising: a wide filter and a narrow filter for receiving an output of a front end and for outputting intermediate frequency signals; a first detector for receiving the intermediate frequency signal from said wide filter and a second detector for receiving the intermediate frequency signal from said narrow filter, said first and second detectors demodulating the intermediate frequency signals to output demodulated signals; a subtracter for outputting a difference between said demodulated signals; a switch switched to a first position for directing said demodulated output from said first detector to the following circuit when the difference is below the reference level, and switched to a second position for directing said demodulated output from said second detector to a following circuit when the difference is above a reference level.
Claim 2
Dependent Claim
23 words
A radio receiver according to Claim 1, wherein said receiver further includes a delay circuit inserted between said subtracter and said first detector.
Claim 3
Dependent Claim
49 words
A radio receiver according to Claim 1, wherein said receiver further includes a low-pass filter for receiving the output of said subtracter to output a filtered output signal and a comparator for comparing said filtered output signal with said reference level to output a signal for driving said switch.
Claim 4
Dependent Claim
57 words
A radio receiver according to Claim 3, wherein said switch is switched said first position in response to an external signal during a seek operation of the receiver, said switch being switched to said second position in response to the output of said comparator when the receiver is interfered by an adjacent station during the seek operation.
Claim 5
Dependent Claim
63 words
A radio receiver according to Claim 3, wherein said receiver further includes a signal-level detecting circuit placed between said first detector and said switch, said signal-level detecting circuit outputting a signal for controlling said switch to direct the output of said second detector to the following circuit when a field intensity signal of a frequency currently being received is below a predetermined level.
Claim 6
Dependent Claim
48 words
A radio receiver according to Claim 3, wherein said receiver further includes a controller inserted between said subtracter and said comparator, said controller receiving the output of said subtracter to detect pulse noise therein and supplying said comparator with said reference level in accordance with said pulse noise.
Claim 7
Dependent Claim
52 words
A radio receiver according to Claim 3, wherein said receiver further includes a muting circuit inserted between said switch and the following circuit, and a signal-level detecting circuit for outputting a signal for causing said muting circuit to attenuate a signal therethrough when said field intensity signal is below a predetermined level.
Claim 8
Dependent Claim
56 words
A radio receiver according to Claim 3, wherein said receiver further includes a signal-level detecting circuit placed between said first detector and said comparator, said signal-level detecting circuit supplying said comparator with said reference level in accordance with said field intensity, said signal holding said reference level when said switch is switched to said second position.
Claim 9
Dependent Claim
70 words
A radio receiver according to Claim 3, wherein said receiver further includes a signal-level detecting circuit placed between said first detector and said comparator, said signal-level detecting circuit supplying said comparator with said reference level in accordance with said field intensity, said receiver further includes a shaper for receiving the output of said comparator and outputting a delayed signal to said switch when pulse noise is in said reference level.
Claim 10
Dependent Claim
62 words
A radio receiver according to Claim 1, wherein said receiver further includes a trigger generator connected to said first detector for outputting a trigger signal when said field strength signal is below a predetermined level and a decoder for storing receiving frequency data therein and for outputting said data in response to said trigger signal so as to receive an alternative station.
References Cited (Backward Citations)
No citation records indexed.
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