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US 7,582,849 B2Granted
Thermal head, driving method and thermal head drive circuit
AssigneeFujitsu Component Limited
InventorsSumio Watanabe, Fumio Sakurai, Yukihiro Mori, Norio Endo, Shuko Yamaji, Tomoyuki Yokoyama
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Abstract
A thermal head driving method of driving thermal heads is disclosed. The method includes a step of dividing the thermal heads into plural groups, providing for each of the groups a common potential terminal, a step of using a drive circuit to drive the thermal heads of one or more of the groups, and a step of applying an operating voltage to the common potential terminal of said one or more groups driven by the drive circuit.
Claims3
A control circuit that drives a thermal head with a common potential supplied via a power supply terminal, comprising:
- first and second current detection circuits that detect respective first and second currents supplied in respective first and second power supply lines to the power supply terminal;
- a control unit that detects a failure in the first and second power supply lines by detecting the current to be supplied to the power supply terminal while the thermal head is driven based on evaluation data;
- and
- first and second switching circuits that switch supply and suspension of supply of power to the respective first and second power supply lines, wherein:
- when a failure is detected in the first power supply line and not the second power supply line, the control unit controls the first switching circuit to suspend supply of power to the first power supply line and performs printing in a low-speed printing mode using a low-speed printing mode drive current supplied via the second power supply line to the power supply terminal.
2 more elements
Dependencies are inferred from the claim text.