Rechargeable electronic apparatus

• US 6,060,862 A
• Filed: 11/24/1998
• Issued: 05/09/2000
• Est. Priority Date: 08/21/1996
• Status: Expired due to Fees

• Current Assignee: Citizen Holdings Co., Ltd.
• Original Assignee: Citizen Watch Co Limited (Citizen Electronics Company Limited)
• Inventors: Fujita, Kenji, Igarashi, Kiyotaka, Sase, Masahiro
• Primary Examiner(s): Wong, Peter S.
• Assistant Examiner(s): Luk, Lawrence
• Application Number:
  US09/051,646
• Time in Patent Office: 532 Days
• Field of Search: 320/132, 320/130, 320/149, 320/148, 320/128
• US Class Current: 320/132
• 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: H02J 7/0031 using battery or load disconnect circuits H02J9/002 takes precedence
• CPC Class Codes: H02J 7/00714 in response to battery charging or discharging current

Abstract

A electrical-generating type of electronic apparatus, such as a rechargeable electronic watch capable of allowing the user to easily verify the detection of the charge capacity of the battery is provided, this being a rechargeable electronic apparatus 100 having an electrical generation means 3, an electrical storage means 7, a reverse-flow prevention means 5 that prevents reverse flow of charging current to the electrical storage means 7, and a time display means 6 which has the electrical storage means 7, which is charged by the electrical generation means 3, as a power source, this apparatus further being provided with a charging condition detection means 30, which detect the charging condition of the electrical storage means 7, a charging cutoff means 9 which is provided in a charging path between the electrical generation means 3 and the electrical storage means 7, and a charging condition notification means 6 that makes notification of the charging condition of the electrical storage means 7, based on a detection signal from the charging condition detection means 30, the charging condition detection means 30 causing the charging cutoff means to operate during the detection of the charging condition of the electrical storage means 7, so as to cut off the charging.

Claims

1. A rechargeable electronic apparatus comprising:

an electrical generation means;

an electrical storage means which stores electromotive power from said electrical generation means;

a reverse-flow prevention means which prevents reverse flow of a charging current to said electrical storage means;

an information display means which displays information;

a charging condition detection means which detects a charging condition of said electrical storage means;

a charging cutoff means which is provided in a charging path between said electrical generation means and said electrical storage means; and

a charging condition notification means which makes notification of said charging condition based on a detection signal from said charging condition detection means,

wherein during detection by said charging condition detection means of said charging condition of said electrical storage means, said charging cutoff means is caused to operate, thereby cutting off said charging.

2. A rechargeable electronic apparatus according to claim 1, wherein said charging condition is judged based on either a charging voltage value or a charging current value.

3. A rechargeable electronic apparatus according to either claim 1 or claim 2, wherein said charging condition detection means is provided with a charging condition measurement means that either measures a charging voltage of said electrical storage means or detects a charging current to said electrical storage means, a memory means that stores a plurality of steps of set reference values of voltage or current, a comparison means that performs comparison between a voltage value or a current value of said electrical storage means which is measured by said charge condition measurement means and either one of said reference values that are stored in said memory means, and an output means that outputs a result of said comparison.

4. A rechargeable electronic apparatus according to either claim 1 or claim 2, wherein said charging cutoff means comprises a function that, in response to the point in time at which the detection of said charging condition of the electrical storage means is performed, cuts off said charging path between said electrical generation means and said electrical storage means.

5. A rechargeable electronic apparatus according to claim 4, wherein said charging cutoff means, in a case in which a voltage value of said electrical storage means corresponds to a prescribed voltage value, cuts off said charging path between said electrical generation means and said electrical storage means, and wherein a residual capacity of said electrical storage means is measured.

6. A rechargeable electronic apparatus according to either claim 1 or claim 2, wherein said charging condition detection means includes a function that detects a full-charge condition of said electrical storage means.

7. A rechargeable electronic apparatus according to claim 6, further comprising a full-charge detection means which detects whether the charging condition of said electrical storage means is the full-charge condition.

8. A rechargeable electronic apparatus according to claim 7, wherein said full-charge detection means comprises a voltage measurement section that measures an output voltage of said electrical storage means and that outputs a voltage measurement data, and a voltage drop detection section that, based on at least two voltage measurement data from said voltage measurement means, if a voltage drop value at a prescribed time is within an arbitrary reference voltage value, detects this as said full-charge condition, and outputs a full-charge detection signal.

9. A rechargeable electronic apparatus according to claim 8, further comprising a measurement start detection means which, when the voltage of said electrical storage means is detected as being at least a prescribed voltage, based on said voltage measurement data from a voltage measurement section that is part of said charging condition measurement means, outputs a full-charge measurement start signal for the purpose of controlling the start of a full-charge measurement operation, and wherein, based on said full-charge measurement start signal from said measurement start detection means, said voltage drop detection section outputs a control signal that starts a detection operation.

10. A rechargeable electronic apparatus according to claim 9, wherein said charging condition detection means is provided with an electromotive force measurement means that measures an electromotive force from said electrical generation means, and wherein, based on a measured value of said electromotive force measurement means, a prescribed voltage value which is to be compared with a voltage value of said electrical storage means in said measurement start detection means is switched.

11. A rechargeable electronic apparatus according to claim 9, wherein said apparatus further comprises an electromotive force measurement means that measures an electromotive force from said electrical generation means, and wherein, based on a measured value of said electromotive force measurement means, said reference voltage value to be compared with a voltage drop value in said voltage drop detection section is switched.