Time Adjustment Device, Timekeeping Device with a Time Adjustment Device, and a Time Adjustment Method

• US 20090016167A1
• Filed: 06/03/2008
• Published: 01/15/2009
• Est. Priority Date: 07/09/2007
• Status: Abandoned Application

• Current Assignee: Seiko Epson Corporation (Seiko Group)
• Original Assignee: Seiko Epson Corporation (Seiko Group)
• Inventors: Matsuzaki, Jun
• Application Number:
  US12/132,374
• Publication Number:
  US 20090016167A1
• Time in Patent Office: Days
• US Class Current: 368/10
• CPC Class Codes: G01S 19/235 Calibration of receiver components
• CPC Class Codes: G04R 20/06 Decoding time data; Circuits therefor

Abstract

A time adjustment device has a reception unit that receives satellite signals transmitted from a positioning information satellite; a satellite signal processing unit that processes the satellite signal received by the reception unit and acquires at least satellite time information; a timekeeping unit that keeps time internally; and a time information adjustment unit that adjusts the internal time based on the satellite time information; wherein the reception unit and the satellite signal processing unit operate alternatively.

Claims

1. A time adjustment device comprising:

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

a satellite signal processing unit that processes the satellite signal received by the reception unit and acquires at least satellite time information;

a timekeeping unit that keeps time internally; and

a time information adjustment unit that adjusts the internal time based on the satellite time information;

wherein the reception unit and the satellite signal processing unit operate alternatively.

2. The time adjustment device described in claim 1, wherein:

the reception unit comprises a frequency processing unit that frequency converts the received satellite signal; and

a demodulation unit that demodulates the satellite signal after frequency conversion by the frequency processing unit; and

the frequency processing unit, the demodulation unit, and the satellite signal processing unit operate alternatively.

3. The time adjustment device described in claim 1, further comprising:

a satellite signal storage unit that stores the satellite signal received by the reception unit.

4. The time adjustment device described in claim 1, further comprising:

a counter unit that acquires reception unit operating time information, which is operation-related time for the reception unit, and/or satellite signal processing time information, which is operation-related time for the satellite signal processing unit;

wherein the time information adjustment unit adjusts the internally kept time based on adjustment timing information, which is calculated from the reception unit operating time information and/or satellite signal processing time information.

5. The time adjustment device described in claim 1, wherein:

the satellite signal contains propagation delay time information, which is the time required for the satellite signal of the positioning information satellite to arrive.

6. The time adjustment device described in claim 4, wherein:

the reception unit operating time information contains satellite signal reception time information, which is the time that the reception unit receives the satellite signal of the positioning information satellite; and

the satellite signal reception time information is the shortest time required to acquire the satellite time information and adjustment timing information.

7. The time adjustment device described in claim 4, wherein:

the counter unit operates based on a high precision oscillator.

8. The time adjustment device described in claim 1, wherein:

the satellite signal contains subframe number information;

the time adjustment device further comprises a subframe number acquisition unit that acquires target subframe number information including the week number value of the GPS time and/or UTC (universal time, coordinated) parameter information from the subframe number information; and

the target subframe of the satellite signal is acquired based on the target subframe number information.

9. The time adjustment device described in claim 1, wherein:

the satellite signal contains satellite number information, Doppler frequency information, and C/A code phase information for the positioning information satellite; and

the time adjustment device further comprises a captured satellite information storage unit that stores the received satellite number information, Doppler frequency information, and C/A code phase information for the positioning information satellite.

10. The time adjustment device described in claim 6, wherein:

the satellite signal reception time is from the length of the C/A code to the length of one message bit.

11. The time adjustment device described in claim 1, wherein:

the satellite signal is received a plurality of times from the same positioning information satellite; and

the time adjustment device further comprises a match detection unit that determines if there is a match between the plural satellite time values acquired from the plural received signals.

12. The time adjustment device described in claim 1, wherein:

the satellite signals are acquired from a plurality of positioning information satellites; and

the time adjustment device further comprises a different-satellite match detection unit that determines if there is a match between the plural time values acquired from the plural positioning information satellites.

13. A timepiece with a time adjustment device, comprising:

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

a satellite signal processing unit that processes the satellite signal received by the reception unit and acquires at least satellite time information;

a timekeeping unit that keeps time internally; and

a time information adjustment unit that adjusts the internal time based on the satellite time information;

wherein the reception unit and the satellite signal processing unit operate alternatively.

14. A time adjustment method comprising:

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

a satellite signal processing unit that processes the satellite signal received by the reception unit and acquires at least satellite time information;

a timekeeping unit that keeps time internally; and

a time information adjustment unit that adjusts the internal time based on the satellite time information;

wherein the reception unit and the satellite signal processing unit operate alternatively; and

the satellite signal processing unit operates on the satellite signal after the satellite signal is received by the reception unit.