Electronic apparatus

• US 8,692,518 B2
• Filed: 07/24/2007
• Issued: 04/08/2014
• Est. Priority Date: 07/27/2006
• Status: Expired due to Fees

• Current Assignee: Citizen Watch Co Limited (Citizen Electronics Company Limited)
• Original Assignee: Citizen Holdings Co., Ltd. (Citizen Electronics Company Limited)
• Inventors: Uchida, Takayuki, Satoh, Kohichi, Namekawa, Masaaki
• Primary Examiner(s): Baldridge, Benjamin M
• Application Number:
  US12/375,192
• Publication Number:
  US 20100072974A1
• Time in Patent Office: 2,450 Days
• Field of Search: 324/133, 320/133
• US Class Current: 320/133
• CPC Class Codes: G01R 31/3835 involving only voltage measurements
• CPC Class Codes: G04C 10/02 the power supply being a radioactive or photovoltaic source
• CPC Class Codes: G04C 10/04 with means for indicating the condition of the power supply in general G01R31/36
• CPC Class Codes: G04G 19/00 Electric power supply circuits specially adapted for use in electronic time-pieces
• CPC Class Codes: G04G 19/08 Arrangements for preventing voltage drop due to overloading the power supply

Abstract

The invention provides a compact and highly reliable electronic apparatus that can be driven by a small-capacity battery, and that can achieve high-speed continuous driving of a load by quickly judging the recovery state of the battery after driving the load. More particularly, the invention provides an electronic apparatus includes a power supply, a load, a load driver for driving the load by the power supply, a power supply state detecter for outputting power supply recovery information by measuring physical quantity of the power supply at predetermined intervals of time after the driving of the load is stopped, and a controller for instructing the load driver to drive the load, based on the power supply recovery information supplied from the power supply state detecter.

Claims

1. An electronic apparatus comprising:

a power supply having a battery;

a load;

a load driver that drives said load by said battery;

a power supply state detector that outputs power supply recovery information, wherein said power supply recovery information is obtained by repeatedly sampling a measured voltage value of said battery at predetermined intervals of time beginning at a start time, measured after a time said driving of said load is stopped, said sampling being performed under the condition that said battery has not recovered after the driving of said load is stopped; and

a controller that instructs said load driver to drive said load, based on said power supply recovery information supplied from said power supply state detector,

wherein said controller controls said power supply state detector so as to select said predetermined intervals of time, each of which is different in duration, or selects a starting time for sampling the measured voltage of said battery from a plurality of starting times after said driving of said load is stopped.

2. The electronic apparatus according to claim 1, wherein said controller controls said power supply state detector to select said predetermined interval of time or selects said starting time on the basis of a recovery condition of said power supply, which is obtained under the condition that the driving of said load is stopped.

3. The electronic apparatus according to claim 2, further comprising a memory for storing the recovery condition under the condition that the driving of said load is stopped at a past time or the start timing for sampling which is obtained under the condition that the driving of said load is stopped, and

wherein said controller selects said predetermined interval of time or said starting time on the basis of said stored recovery condition.

4. The electronic apparatus according to claim 3, wherein when said power supply state detector does not output said power supply recovery information even though the sampling of the measured voltage of said battery has been performed a predetermined number of times, or when it is determined that said battery has not recovered sufficiently to be able to drive said load even though a predetermined time has elapsed from the start of the sampling of the measured voltage of said battery, said controller causes said electronic apparatus to enter a power recovery mode in which priority is given to making said battery recover.

5. The electronic apparatus according to claim 4,

wherein said memory further stores past detection conditions including said predetermined intervals of time, said reference value, said predetermined number of sampling, or said predetermined elapsed time, and

wherein said controller varies, based on said previous sampling conditions stored in said memory, one or more of said predetermined intervals of time, said reference value, and said predetermined number of samplings.

6. The electronic apparatus according to claim 3, wherein:

said load is a first load and said electronic apparatus has a second load different from said first load,

said power supply state detector outputs said power supply recovery information intended for said first load and said second load,

said controller instructs said load driver to drive said second load, based on said power supply recovery information obtained by driving said first load,

said controller controls said power supply state detector so as to select said predetermined interval of time from a plurality of intervals of time, each of which is different in duration, or selects a starting time for repeatedly sampling the measured voltage value of said battery from a plurality of starting times, on the basis of the power supply recovery information, which is obtained by the driving of said first load when the sampling of the measured voltage value of said battery is performed after the driving of said second load is stopped.

7. The electronic apparatus according to claim 1, wherein said recovery condition is recovery time.

8. The electronic apparatus according to claim 1, wherein said controller selects said predetermined interval of time or said starting time on the basis of a driving condition of said load, which is obtained under the condition that the driving of said load is stopped.

9. The electronic apparatus according to claim 8, wherein said driving condition comprises forward direction driving and backward direction driving.

10. The electronic apparatus according to claim 1, wherein said controller selects said predetermined interval of time or said starting time on the basis of a battery charging condition, an ambient temperature, or a battery capacity.

11. The electronic apparatus according to claim 1, wherein said controller varies the frequency for performing said power supply state detection on the basis of the recovery state of said power supply, which is obtained under the condition that the driving of said load is stopped.

12. The electronic apparatus according to claim 1, wherein

said power supply state detector compares the voltage of said battery with a reference value at said predetermined interval of time and, when the voltage of said battery exceeds said reference value, outputs said power supply recovery information comprising a determination that said battery has recovered sufficiently to be able to drive said load, whereupon

said load driver resumes the driving of said load in accordance with a drive instruction supplied from said controller.

13. The electronic apparatus according to claim 1, wherein said predetermined interval of time is shorter than a recovery time that said battery requires to recover sufficiently to be able to drive said load.

14. The electronic apparatus according to claim 1, wherein said load is one of a motor, a vibrator, an audio device, an illumination device, a display device, a communication device, an imaging device, or a sensor.