Radio watch

• US 7,719,928 B2
• Filed: 06/08/2006
• Issued: 05/18/2010
• Est. Priority Date: 06/08/2006
• Status: Expired due to Fees

• Current Assignee: Seiko Epson Corporation (Seiko Group)
• Original Assignee: Seiko Epson Corporation (Seiko Group)
• Inventors: Meltzer, David, Blum, Gregory
• Primary Examiner(s): Miska; Vit W
• Application Number:
  US11/423,101
• Publication Number:
  US 20070286028A1
• Time in Patent Office: 1,440 Days
• Field of Search: 368/46, 368/47
• US Class Current: 368/47
• CPC Class Codes: G04R 20/10 Tuning or receiving; Circuits therefor

Abstract

Apparatuses, circuits, and methods for receiving at least one radio signal in a radio controlled timing apparatus using a single timing source. The present invention advantageously eliminates the need to provide an additional timing source to receive at least one radio signal, and therefore reduces the material cost and eliminates many engineering challenges.

Claims

1. A multi-region, radio controlled timing apparatus for receiving, and responding to, a different broadcast time-code signal in each of multiple regions, each of said different broadcast time-code signals being transmitted at a different carrier-transmission frequency, said multi-region, radio controlled timing apparatus comprising:

a local reference oscillating signal source for generating a local reference timing signal at a first frequency;

a real-time signal generator responsive to said local reference timing signal, said real-time signal generator producing a local-time-tracking signal from said local reference timing signal;

a frequency synthesizer responsive to said local reference timing signal and having a frequency-select input, said frequency synthesizer converting said local reference timing signal into a local-carrier signal having a frequency determined in accordance with said frequency-select input;

a radio receiver coupled to said frequency synthesizer, said radio receiver receiving any of said different broadcast time-code signals and demodulating the received broadcast time-code signal by use of said local-carrier signal to recover a master-time signal; and

a timing mechanism coupled to said real-time signal generator and to said radio receiver, said timing mechanism tracking the passage of time as determined from said local-time-tracking signal and adjusting its currently tracked time in accordance with said master-time signal;

wherein said frequency synthesizer includes a phase locked loop (PLL) and a frequency-select control logic circuit;

said PLL having a phase and/or frequency detector and a voltage controlled oscillator (VCO), said phase and/or frequency detector having a signal-in input node responsive to said local reference timing signal and a feedback input node, said VCO producing an oscillating output in response to said phase and/or frequency detector, said oscillating output being coupled to said feedback input node;

said frequency-select control logic circuit having an input for receiving said frequency-select input, and at least a first frequency-change output for adjusting a frequency of a signal at one of said signal-in input node and said feedback input node;

wherein said frequency-select control logic circuit further has a second frequency-change output, said frequency synthesizer further having;

a first adjustable frequency divider coupling said local reference timing signal to said signal-in input node, a first frequency divisor value of said first adjustable frequency divider being set by said first frequency-change output; and

an second adjustable frequency divider coupling said oscillating output to said feedback input node, a second frequency divisor value of said second adjustable frequency divider being set by said second frequency-change output;

wherein said first and second frequency divisor values are chosen by said frequency-select control logic circuit to assign said local-carrier signal said target frequency.

2. The multi-region, radio controlled timing apparatus of claim 1, wherein said frequency synthesizer further includes third adjustable frequency divider coupled to receive said oscillating output and to produce said local-carrier signal, said frequency-select control logic circuit having a third frequency-change output, a third frequency divisor value of said third adjustable frequency divider being set by said second frequency-change output, wherein said local-carrier signal is assigned said target frequency further in response to said third frequency divisor value.

3. The circuit of claim 1, wherein said radio controlled timing apparatus is a timepiece.

4. The circuit of claim 3, wherein said timepiece is a watch.

5. The circuit of claim 3, wherein said timepiece is a clock.

6. The circuit of claim 3, wherein said timepiece has a time display including movable time hands.

7. The circuit of claim 3, wherein said time code signal is a data signal.