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:
Apr. 19, 2005
Filed:
Apr. 17, 2002
Hiroyuki Handa, Hirakata, JP;
Takuya Ishii, Suita, JP;
Yasufumi Nakajima, Hirakata, JP;
Yasuhiko Bito, Minamikawachi-gun, JP;
Shinji Kasamatsu, Katano, JP;
Yoshiaki Nitta, Hirakata, JP;
Hiroyuki Handa, Hirakata, JP;
Takuya Ishii, Suita, JP;
Yasufumi Nakajima, Hirakata, JP;
Yasuhiko Bito, Minamikawachi-gun, JP;
Shinji Kasamatsu, Katano, JP;
Yoshiaki Nitta, Hirakata, JP;
Matsushita Electric Industrial Co., Ltd., Osaka, JP;
Abstract
The present invention provides a battery-driven electronic device for which a long time use of the battery can be achieved and mobile communications equipment such as a portable telephone. Even if the time at which the output voltage of a batterybecomes below the supply voltage required by a loadincluding a power amplifier for wireless communications comes earlier than a conventional lithium ion battery because of its discharge characteristics that the battery voltage change ratio is 0.25 or more, a step-up and -down converteroperates as follows. When the output voltage of the battery is higher than the supply voltage required by the load, the voltage is set to a predetermined supply voltage by the step-down operation mode. When the output voltage of the battery is decreased and becomes lower than the supply voltage required by the load, the voltage is set to a predetermined supply voltage by the step-up operation mode. Thus, even for a battery employing a new material having a high energy density, a long term use of the battery can be achieved.