National weather radio reception by synthesizing only center frequency

• US 5,144,440 A
• Filed: 08/06/1990
• Issued: 09/01/1992
• Est. Priority Date: 08/06/1990
• Status: Expired due to Term

• Current Assignee: Thomson Consumer Electronics Incorporated (Vantiva SA)
• Original Assignee: Thomson Consumer Electronics Incorporated (Vantiva SA)
• Inventors: Wignot, Leroy S., Nortrup, Kevin E.
• Primary Examiner(s): Groody, James J.
• Assistant Examiner(s): HSIA, SHERRIE Y
• Application Number:
  US07/561,586
• Time in Patent Office: 757 Days
• Field of Search: 358/191.1, 358/189, 358/193.1, 358/188, 358/196, 358/198, 358/197, 358/195.1, 455/168, 455/188, 455/190, 455/191, 455/197, 455/179, 455/184, 455/314, 455/315, 455/339, 455/189, 455/180, 455/176, 333/175, 333/167, 333/184, 333/185
• US Class Current: 348/729
• CPC Class Codes: H04B 1/16 Circuits
• CPC Class Codes: H04N 5/44 Receiver circuitry for the reception of television signals according to analogue transmission standards H04N5/14 takes precedence

Abstract

A television receiver includes a single tuner for tuning both television channels and broadcast FM stations. The tuner is operated at a fixed gain setting in FM reception mode. The tuner serves as the first conversion stage of a double conversion FM receiver, wherein the mixer of an FM radio integrated circuit serves as the second conversion stage. The arrangement operates at a specific and non-arbitrary first IF frequency. The FM receiver is also capable of automatically receiving National Weather Service broadcasts on that one of NWS'"'"'s seven allocated frequencies which is operating in a listener'"'"'s area. The receiver provides an on-screen display of the currently tuned FM channel number.

Claims

1. A television receiver, comprising:

tuner means for operating in a first mode for receiving television RF signals, said tuner means selecting a particular television RF signal from a plurality of television RF signals in response to a control signal;

said tuner means also operating in a second mode as a first frequency conversion stage for a double conversion broadcast FM radio signal receiver, for receiving broadcast FM radio RF signals and FM broadcast signals of the National Weather Service, said tuner means selecting one of a particular broadcast FM radio RF signal from a plurality of broadcast FM radio RF signals and a broadcast FM signal of said National Weather Service in response to said control signal, and for converting said selected FM RF signal to a first intermediate frequency;

a second frequency conversion stage of said double conversion broadcast FM radio signal receiver, said second frequency conversion stage receiving said selected FM radio signal at said first intermediate frequency and converting said selected FM radio signal at said first intermediate frequency to a second intermediate frequency;

means for demodulating audio signals from said selected FM radio signal at said second intermediate frequency;

said double conversion FM signal receiver also being tuned by a control means substantially to the center of the band of frequencies of the National Weather Service, said FM signal receiver automatically receiving signals broadcast on any one of the frequencies of said band of National Weather Service frequencies; and

said control means generating said control signal for causing said tuner means to select one of said particular television RF signal, said particular broadcast FM radio RF signal, and said signals of said National Weather Service band of frequencies.

2. The television receiver of claim 1, wherein said second intermediate frequency is 10.7 MHz.

3. The television receiver of claim 2, wherein said second frequency conversion stage is an element of an FM radio receiver integrated circuit.

4. The television receiver of claim 1, wherein said band of National Weather Service frequencies includes the frequencies 162.400 MHz and 162.550 MHz.

5. The television receiver of claim 4, wherein said tuner means is tuned, in said second mode of operation, to said center of said National Weather Service band of frequencies, said center being approximately 162.475 MHz, said tuning of said tuner means to said center being sufficient to automatically receive broadcasts at each of said frequencies in said band.

6. An FM weather radio for receiving broadcasts of the National Weather Service in a band of reserved FM frequencies, comprising:

tuner means operating as a first frequency conversion stage for a double conversion broadcast FM radio signal receiver, for converting signals of said reserved FM band to a first intermediate frequency;

a second frequency conversion stage of said double conversion broadcast FM radio signal receiver, said second frequency conversion stage receiving said signals at said first intermediate frequency and converting said signals to a second intermediate frequency; and

means for demodulating audio signals from said signals at said second intermediate frequency;

said double conversion FM signal receiver being tuned substantially to the center of the band of frequencies of the National Weather Service, said FM signal receiver automatically receiving signals broadcast on any one of the frequencies of said band of National Weather Service frequencies.

7. The FM weather radio of claim 6, wherein said tuner means is tuned to said center of said National Weather Service band of frequencies, said center being approximately 162.475 MHz, said tuning of said tuner means to said center being sufficient to automatically receive broadcasts at each of said frequencies in said band.