| 摘要 |
PURPOSE:To erect a toner chain even between magnetic poles of a magnetic roller and to prevent occurrence of development stripes by magnetizing a recording electrode needle opposing to the electrode at timing changed by rotation of the magnetic roller of a magnetic toner developing device. CONSTITUTION:A wire is wound in the longitudinal direction of a recording electrode 1 to form a coil 71. By flowing current to the coil, the recording electrode needle (nickel wire) 2 is magnetized. When change in magnetic flux is measured at the position of the recording electrode needle 2 while the magnetic roller 5 is in rotation, the state in which a magnetic pole (S pole or N pole) arrives at the position of the recording electrode needle 2 becomes the apex (position that shows the maximum values of plus and minus) of the waveform, and conversely, in the state where the changing part of the magnetic pole arrives, its magnetic flux becomes 0. Accordingly, by setting timing of current applied to the coil to magnetize the recording electrode needle to the changing part of the magnetic pole, the toner chain can be erected upright even between magnetic poles, and occurrence of development fringes can be prevented. |
