| 摘要 |
PURPOSE:To prevent an ink from needlessly flying even when a needle comes off the region of a recording paper, by a construction wherein an electrode opposed to a needle provided in a printing head is provided with a contact surface brought into contact with a recording paper and stepped parts which are spaced from the needle. CONSTITUTION:An ink in a slit 31 between magnetic poles 30 forms an ink film 32, and the needle 24 is protruded to the side of the recording paper 12. In this case, a tip part 34 of the needle 34 does not make contact with the paper 12, but sincean electric field is applied by a power source part 54, the ink adhered to the tip part 34 of the needle 24 approaching the electrode 47 is caused to fly toward the electrode 47 under the electric field, and forms a dot on the surface of the paper 12. The paper 12 is disposed over the entire part of the contact surface 47a of the electrode 47, and when the needle 24 comes off the region of the paper 12, it is opposed to the stepped part 47b of the electrode 47b, where the electric field strength between the needle 24 and the part 47b is extremely low, so that there is no possibility of spark discharge or needless flying of the ink. |
