Timekeeping device and satellite signal reception method for a timekeeping device

• US 8,437,226 B2
• Filed: 01/09/2012
• Issued: 05/07/2013
• Est. Priority Date: 12/19/2007
• Status: Expired due to Fees

• Current Assignee: Seiko Epson Corporation (Seiko Group)
• Original Assignee: Seiko Epson Corporation (Seiko Group)
• Inventors: Matsuzaki, Jun
• Primary Examiner(s): Miska, Vit W
• Application Number:
  US13/346,140
• Publication Number:
  US 20120170425A1
• Time in Patent Office: 484 Days
• Field of Search: 368/10, 368/14, 368/47, 342/357.4, 342/357.65, 342/357.67, 342/357.72, 342/357.74
• US Class Current: 368/47
• CPC Class Codes: G01S 19/14 specially adapted for specific applications
• CPC Class Codes: G01S 19/24 Acquisition or tracking or demodulation of signals transmitted by the system synchronisation aspects of direct sequence spread spectrum modulation H04B1/7073
• CPC Class Codes: G01S 19/34 Power consumption
• CPC Class Codes: G04R 20/04 Tuning or receiving; Circuits therefor

Abstract

A timekeeping device has a reception unit that receives a satellite signal transmitted from a positioning information satellite, a time information generating unit that generates time information based on the received satellite signal, a time display unit that displays the time information, and a reception control unit that controls the reception unit. The reception control unit includes a signal condition detection unit that detects a signal condition of the received satellite signal, and a reception setting unit that sets the reception unit to a single satellite mode or a multi-satellite mode based on the detected signal condition.

Claims

1. A timekeeping device, comprising:

a reception unit that receives a satellite signal transmitted from a positioning information satellite;

a time information generating unit that generates time information based on the received satellite signal;

a time display unit that displays the time information; and

a reception control unit that controls the reception unit;

wherein the reception control unit includes

a signal condition detection unit that detects a signal condition of the received satellite signal, and

a reception setting unit that sets the reception unit to a single satellite mode or a multi-satellite mode based on the detected signal condition.

2. The timekeeping device described in claim 1, wherein the reception setting unit sets the reception unit to the signal satellite mode at a start of a reception process.

3. The timekeeping device described in claim 2, wherein the reception setting unit switches to the multi-satellite mode when a signal strength of the received satellite signal is less than a predetermined threshold.

4. The timekeeping device described in claim 2, wherein the reception setting unit switches to the multi-satellite mode when the time information cannot be generated within a time duration.

5. The timekeeping device described in claim 4, wherein the reception setting unit sets the time duration based on a signal strength of the received satellite signal.

6. The timekeeping device as described in claim 1, wherein the reception unit receives a plurality of satellite signals in the multi-satellite mode, and the reception control unit stops a reception process when the time information generating unit generates the time information based on at least one received satellite signal.

7. The timekeeping device as described in claim 1, further comprising:

an internal time information generating unit that generates internal time information; and

a time information adjusting unit that adjusts the internal time information based on the time information.