Ink jet recording apparatus and ink ejection control method

Abstract

Disclosed are an ink jet recording apparatus and method to achieve good balance between the amount of ink supplied and the amount of ink ejected. An ink jet head of the recording apparatus has an ink reservoir chamber having a predetermined capacity for receiving ink from an ink source. The ink reservoir chamber has a nozzle for ejecting ink, and a piezoelectric element. The piezoelectric element is deformable by changing a drive voltage applied thereto, so as to change the capacity of the chamber. A control unit controls the drive voltage applied to the piezoelectric element from the drive voltage generator so that the capacity of the ink reservoir chamber is increased to a first value in a supplying stage, and then reduced to a second value in an ejecting stage, in each ink ejection cycle. Furthermore, the control unit changes the displacement of the piezoelectric element by changing the waveform of the drive voltage. Therefore, in a relatively later part of the ejection stage, the chamber capacity is maintained at a third value between the first and second values, and then reduced to the second value, thus allowing the supplying of ink for the next cycle to be quickly and reliably performed.