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US 6,888,355 B2Granted
Electronic apparatus having battery power source and control method for the electronic apparatus
AssigneeSeiko Epson Corporation
InventorsKoji Kitazawa, Hajime Kurihara, Motomu Hayakawa, Tsukasa Kosuda, Katsuyuki Honda
Life of this patent
Estimating the term…
Abstract
A voltage and internal resistance of a battery are measured in advance as its capacity decreases. In a flash memory of a device powered by the battery, voltages necessary to drive a motor, an EL display, and a bezel input unit are stored. By comparing the voltage of the battery with a resistor connected as a dummy load and the voltage read from the flash memory, it can be determined whether it is possible to drive the motor, the EL display, or the bezel input unit.
Claims33
An electronic apparatus comprising:
- a power supply that supplies power;
- a driven unit that is driven by the power from the power supply;
- a dummy load that discharges the power supply;
- a switch that connects or disconnects the dummy load to or from the power supply;
- a storage unit that stores a group of first voltage values and second voltage values, each of the first voltage values being associated with a respective one of the second voltage values, the first voltage values being voltage values of the power supply when no load, including the dummy load, is connected to the power supply, the second voltage values being voltage values of the power supply when no load other than the dummy load is connected to the power supply and an internal resistance of the power supply is at a highest allowable value, the highest allowable value of the internal resistance being the highest internal resistance of the power supply that can drive the driven unit when no load other than the dummy load is connected to the power supply;
- a voltage measurement unit that measures voltage of the power supply;
- a comparison unit that compares a third voltage value and a fourth voltage value, the third voltage value, measured by the voltage measurement unit, when the dummy load is connected to the power supply and when the driven unit is also connected to the power supply, the fourth voltage value being an extracted one of the second voltage values stored in the storage unit, the extracted one of the second voltage values corresponding to one of the first voltage values that is equal to a fifth voltage value which is measured by the voltage measurement unit when the dummy load is not connected to the power supply and when the driven unit is connected to the power supply;
- and
- a determination unit that determines whether the driven unit can be driven based on the comparison result, and, when it is possible to drive the driven unit, drives the driven unit.
6 more elements
A control method of an electronic apparatus:
- the electronic apparatus comprising;
- a power supply that supplies power;
- a driven unit that is driven by the power from the power supply;
- a dummy load that discharge the power supply;
- a switch that connects or disconnects the dummy load to or from the power supply;
- and
- a storage unit that stores a group of first voltage values and second voltage values, each of the first voltage values being associated with a respective one of the second voltage values1, the first voltage values being voltage values of the power supply when no load, including the dummy load, is connected to the power supply, the second voltage values being voltage values of the power supply when no load other than the dummy load is connected to the power supply and an internal resistance of the power supply is at a highest allowable value, the highest allowable value of the internal resistance being the highest internal resistance of the power supply that can drive the driven unit when no load other than the dummy load is connected to the power supply;
- a voltage measurement unit that measures voltage of the power supply;
- the control method comprising the steps of:
- comparing a third voltage value and a fourth voltage value, the third voltage value, measured by the voltage measurement unit when the dummy load is connected to the power supply and when the driven unit is also connected to the power supply, the fourth voltage value being an extracted one of the second voltage values stored in the storage unit, the extracted one of the second voltage values corresponding to one of the first voltage values that is equal to a fifth voltage value which is measured by the voltage measurement unit when the dummy load is not connected to the power supply and when the driven unit is connected to the power supply;
- determining whether the driven unit can be driven based on the comparison result;
- and
- driving the driven unit when it is determined that driving the driven unit is possible.
10 more elements
Dependencies are inferred from the claim text.