Patent ID: 7508161
Filing Date: 2009-03-24
Classification: B41J,G06F,H02J

Abstract:
1. A system in which a first electronic device with at least a battery as a primary power source and a second electronic device with an AC power source as a primary power source are interconnected via a communication path including a power supply line, the first electronic device operating as a master which controls a slave via the communication path in a master-slave relation and the second electronic device operating as the slave in the master-slave relation, wherein said first electronic device comprises: detection means for detecting residual power of said battery; request means for, in accordance with a result of detection by said detection means, issuing a request to said second electronic device, so as to receive power supply from said second electronic device; switch means for switching over said first electronic device from the master to the slave in accordance with the result of detection by said detection means; charging means for receiving the power supply from said second electronic device via said power supply line and charging said battery when said first electronic device is switched over from the master to the slave by said switch means; and returning means for returning the first electronic device to the master after completion of charging by said charging means, and wherein said second electronic device comprises power supply means for, in accordance with the request by said request means, supplying electric power from said AC power source to said first electronic device via said power supply line, the request corresponding with the second electronic device switching over from the slave to the master.