| 摘要 |
PURPOSE:To protect a head from troubles in an ejection ON signal generating circuit or a transmission system, a malfunction of a nozzle or the like, by providing a waveform shaping circuit at a stage immediately preceding a recording head. CONSTITUTION:Signals except an ENABLE signal are inputted directly from a buffer 103 to a BJ head 105, whereas the ENABLE signal is inputted to the head 105 after being accurately shaped to have a predetermined pulse duration (e.g., 10musec) by a waveform shaping circuit 104. The ENABLE signal is a signal for determining the period of time for which heaters are actually turned ON. Therefore, the ENABLE signal is turned ON while both output signals from shift registers 106a-106d and output signals from latches 107a-107d are ON, for a period of time for energization of the heaters, whereby heater drivers 109a-109d are turned ON, and the heaters are energized, thereby ejecting an ink. If the ON time TON of the ENABLE signal is maintained at an accurate value, breakage of the heaters or failure in ejection would be caused. |
