| 摘要 |
PURPOSE:To maintain an ink injection pressure at constant value at all times and obtain a stabilized and high-quality printed image by a method wherein an ink pressure in an ink jet head is detected and the ink injection pressure is controlled in accordance with a detecting signal. CONSTITUTION:An ink pressure in an ink jet head 5 is detected by a pressure detecting means 13 and is compared with a set pressure value in a control circuit 14. When the detected pressure is out of a range of the set pressure, an exciting current applied to an electromagnetic powder clutch is varied. At that time, a connecting torque of the clutch is varied and an upper limit of pressing of a piston 22 is varied, therefore, even through there is a portion such as a filter 4 or the like in which pressure loss is varied with the lapse of time between a pump 1 and the ink jet head 5, the ink injection pressure may be kept in constant, thereby, printing of stabilized images may be effected. |
