| 摘要 |
PURPOSE:To improve the responsiveness of a recording signal and quality of a picture by providing a positioning member at the tip of a base block whereto a needle electrode is fixed to regulate an interval between the needle electrode and a recording paper sheet, by specifying the resistance value of the tip of the positioning member and by impressing reference potential on this tip. CONSTITUTION:The needle electrode 2 is fixed to the side of the base block 19 formed of an insulator. Ink formed of magnetic fluid is supplied to the tip of the needle electrode 2 by a supply passage (magnet) 3, forming a rise at the tip. The positioning member 21 is provided fixedly at the tip of the base block 19 and the recording paper sheet 6 is made to contact with the tip part 21b of the member, whereby the distance of the sheet 6 from the needle electrode 2 is regulated. Moreover, the specific resistance of the tip part 21b of the positioning member 21 is made smaller than the specific surface resistance and specific volume resistance of the paper sheet 6, while the reference potential to the needle electrode 2 and a gate electrode 1 is impressed on the tip part 21b. |
