Electronic timepiece

• US 8,432,771 B2
• Filed: 08/09/2010
• Issued: 04/30/2013
• Est. Priority Date: 08/18/2009
• Status: Active Grant

• Current Assignee: Seiko Epson Corporation (Seiko Group)
• Original Assignee: Seiko Epson Corporation (Seiko Group)
• Inventors: Matsuzaki, Jun
• Primary Examiner(s): LEON MUNOZ, EDWIN A
• Application Number:
  US12/852,669
• Publication Number:
  US 20110044137A1
• Time in Patent Office: 995 Days
• Field of Search: 368/46, 368/47, 368/10, 368/14, 342/357.06, 342/357.15, 375/354
• US Class Current: 368/47
• CPC Class Codes: G01S 19/14 specially adapted for specific applications
• CPC Class Codes: G04G 21/02 Detectors of external physical values, e.g. temperature
• CPC Class Codes: G04R 20/04 Tuning or receiving; Circuits therefor

Abstract

An electronic timepiece has a reception unit that executes a search process to search for satellite signals that can be captured from among satellite signals transmitted from a plurality of positioning information satellites, and from among the satellite signals captured by the search process receives a satellite signal with signal strength greater than or equal to a specific signal reception threshold value; an information acquisition unit that acquires specific information including at least time information based on a satellite signal received by the reception unit; and a display that displays acquired information. A threshold value changing unit lowers the signal reception threshold value according to a search count, which is the number of times the search process has been applied to the satellite signals of all positioning information satellites.

Claims

1. An electronic timepiece comprising:

a reception unit that executes a search process to search for satellite signals that can be captured from among satellite signals transmitted from a plurality of positioning information satellites, and from among the satellite signals captured by the search process receives a satellite signal with signal strength greater than or equal to a specific signal reception threshold value;

an information acquisition unit that acquires specific information including at least time information based on a satellite signal received by the reception unit;

a display that displays acquired information;

a threshold value changing unit that lowers the signal reception threshold value according to a search count, which is the number of times the search process has been applied to the satellite signals of all positioning information satellites;

a reception environment detection unit that detects the reception environment of the satellite signal; and

an initial threshold value setting unit that sets the initial value of the signal reception threshold value according to the reception environment detected by the reception environment detection unit.

2. The electronic timepiece described in claim 1, wherein:

the reception unit stops the reception operation when the signal reception threshold value is set to a specific minimum by the threshold value changing unit, and the satellite signal cannot be captured within the specific search count after the signal reception threshold value is set to the minimum.

3. The electronic timepiece described in claim 1, further comprising:

a solar cell that receives light and produces electric power; and

wherein the reception environment detection unit detects the reception environment based on power output from the solar cell.

4. The electronic timepiece described in claim 1, wherein:

the reception environment detection unit is a vibration detection unit that detects vibration of the electronic timepiece, and detects the reception environment based on the amount of vibration detected.

5. The electronic timepiece described in claim 1, further comprising:

a mode changing unit that changes to a timekeeping mode for acquiring the time information using the information acquisition unit, or a positioning mode that acquires the positioning information contained in the satellite signal using the information acquisition unit and calculates the position of the electronic timepiece;

wherein

when the positioning mode is selected by the mode changing unit,

the initial threshold value setting unit sets the initial value of the signal reception threshold value according to the reception environment detected by the reception environment detection unit to a specific first signal reception threshold value for positioning, or to a second signal reception threshold value for positioning that is lower than the first signal reception threshold value for positioning; and

when the timekeeping mode is selected by the mode changing unit,

the initial threshold value setting unit sets the initial signal reception threshold value to a signal reception threshold value for timekeeping that is lower than the first signal reception threshold value for positioning.

6. The electronic timepiece described in claim 1, further comprising:

a mode changing unit that changes to a timekeeping mode for acquiring the time information using the information acquisition unit, or a positioning mode that acquires the positioning information contained in the satellite signal using the information acquisition unit and calculates the position of the electronic timepiece;

wherein

when the positioning mode is selected by the mode changing unit,

the initial threshold value setting unit sets the initial value of the signal reception threshold value according to the reception environment detected by the reception environment detection unit to a specific first signal reception threshold value for positioning, or to a second signal reception threshold value for positioning that is lower than the first signal reception threshold value for positioning, and

the threshold value changing unit lowers the signal reception threshold value according to the search count from the initial signal reception threshold value set by the initial threshold value setting unit; and

when the timekeeping mode is selected by the mode changing unit,

the initial threshold value setting unit sets a fixed threshold value for timekeeping that is lower than the first signal reception threshold value for positioning as the initial signal reception threshold value, and

the threshold value changing unit does not lower the fixed threshold value for timekeeping.