The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 09, 2001
Filed:
Aug. 09, 1999
Citizen Watch Co., Ltd., Tokyo, JP;
Abstract
In an electronic timepiece, in which electric power generated by a solar cell (,) is accumulated in an accumulator device (,) and a time keeping means (,) is driven with the accumulated electric power, an electrically on-off controllable switch (,) is provided in a circuit for charging the accumulator device (,) by the solar cell (,), a voltage comparison means (,) intermittently brings the switch (,) into the off-state at predetermined intervals and compares the generated voltage (Vs) by the solar cell and the accumulated voltage (Vb) in the accumulator device (,), and keeps the switch (,) in the off-state as it is when Vs≦Vb and brings the switch (,) into the on-state when Vs>Vb in accordance with the comparison result. Thereby, a reverse flow of an electric current from the accumulator device (,) can be prevented and a voltage drop on charging is eliminated, resulting in enhancement in charging efficiency.