| 摘要 |
PURPOSE:To prevent the injection abnormality of ink which generates dot omission, and to enhance reliability, by providing a dissolved air degassing chamber having an ink sump equipped with a heater between an ink jet head and an ink supply tank. CONSTITUTION:The ink flowing in a dissolved air degassing chamber 2 from an ink supply tank 5 is heated by a heater 3. Since the dissolution ratio of air in the ink is reduced by raising the temp. of the ink, excessive air becomes air bubbles which are, in turn, discharged to the open air from the air discharge port provided to the upper part of the chamber 2. Then, the temp. of the ink supplied to an ink jet head 1 is gradually lowered to obtain the ink reduced in dissolved air as a result. Therefore the generation of air bubbles due to cavitation is prevented in an ink jet chamber and the extremely small air bubbles among ones involved from the leading end part of a nozzle are naturally removed and the injection abnormality of the ink which causes dot omission is prevented and reliability can be enhanced. |
