| 摘要 |
PURPOSE:To ensure that a thermal ink jet head with high functional reliability can be obtained at low cost by providing a temperature sensor on a thermal ink jet head or in its neighborhood, then monitoring a detection output from the temperature sensor and detecting an ink supply state. CONSTITUTION:A temperature sensor 3 and an ink heater 4 are provided between the rear of a thermal ink jet head 1 and a heat sink 2, and the temperature sensor 3 is mounted in a recessed part 8 provided on the heat sink 2. A control device 6 controls the supply of power to a heater 4 based on a detection output from the temperature sensor 3 to keep an ink temperature at almost the same level. If an ink pipe is clogged or an ink supply is suspended in the ink jet head, the temperature of the head rises beyond the normal level. |
