Remaining battery capacity determination method and apparatus

摘要

Method and apparatus for monitoring actual usage of a battery in an ink-jet printer are described. The apparatus partitions a battery-operated or battery-backed up ink-jet printer into its various current-consuming subsystems or modules including sheet advance motor, carriage motor, printhead, logic and sleep circuitry. Firmware within the printer's controller monitors actual usage of each of the modules as a representation of energy consumption thereby and indicates the remaining battery capacity over the life of the printer. Motor usage is monitored by measuring sheet advance mechanism feed motor and printhead carriage drive motor travel distances; printhead usage is monitored by counting ink-jet firings; logic and sleep circuitry usage also may be monitored by estimating. Remaining battery capacity is determined, and optionally indicated more accurately and at negligible cost.