| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for controlling ink ejection which is capable of minimizing variation in ink ejection speed due to the number of gradations and positional deviation of a printing dot. SOLUTION: The ejection or non-ejection of ink is controlled in each pressure chamber (I) by selectively applying plural kinds of drive pulses to respective pressure chambers (I) which are arranged in parallel through partition walls 9 formed of a piezoelectric member, and ink droplets corresponding to the portion of the number of gradations of a printing data is ejected from the ink pressure chamber for ink ejection at each driving frequency. The driving frequency is defined as a maximum ink droplets ejection period corresponding to the portion of the maximum number of the gradation in the period for controlling the ejection of each single ink droplet. The ejection period corresponding to the portion of the number of gradations and the rest of non-ejection period are predetermined by the number of gradations in plural periods for controlling the ejection of each single ink droplet in the driving frequency. The ink is ejected in the ejection period and is not ejected in the non-ejection period from the ink pressure chamber for ink ejection at each driving frequency. |
