| 摘要 |
PURPOSE:To obtain a satisfactory image by a small-sized and inexpensive device with a bipolar magnetic field generating means by giving a specific cylinder outside diameter to a developer carrier. CONSTITUTION:Both poles 3a and 3b are placed on both sides of the center of a magnet roll 3 and the magnetic field range is maximally effectively used, and a sufficient quantity of the developer is stuck to a developing sleeve 2; but when the magnetic pole 3a is not placed in an aperture 4a of a vessel 4, the quantity of the developer stuck to the developing sleeve is too small to cause the variance of image or the like at the time of development. The diameter of the developing sleeve 2 is reduced to solve this problem and the developer is sufficiently carried to obtain an image of good quality though the bipolar magnet roll 3 is used, and especially, the image quality is excellent if the outside diameter of the developing sleeve is 5-25mm. Thus, a satisfactory image free from variance is obtained and this invention contributes to the miniaturization of the whole of the device. |
