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:
Feb. 09, 1999
Filed:
Oct. 01, 1997
Tsutomu Nishikawa, Chigasaki, JP;
Isao Hayashi, Yokohama, JP;
Canon Kabushiki Kaisha, Tokyo, JP;
Abstract
When charging current is switched, the output voltage from the solar cell, namely an input voltage to a charging apparatus, changes, and controlling the input voltage to the charging apparatus does not operate correctly. Furthermore, when charging current decreases in response to a drop of the output voltage from the solar cell, a fully-charged state of the secondary cell is erroneously detected. Still further, when the charging operation is completed in accordance with a timer after charging the secondary cell by a small charging current, the secondary cell is not fully charged. To correct these problems, the input voltage Vin is compared to a voltage value V1, and, if a state in which Vin is higher than V1 (Vin>V1) is moved to a state in which Vin is equal or lower than the V1 (Vin.ltoreq.V1), a charge mode which supplies small charging current starts, thereafter, the charging current is increased for a short period of time at a predetermined time interval, and then, on the basis of a comparison result between Vin and V1 at this time, the subsequent charge mode is controlled. The charged amount of the secondary cell is obtained by measuring the charging current, and the fully-charged state of the secondary battery is determined on the basis of the obtained charged amount.