| 摘要 |
PURPOSE:To prevent image fogging and degradation in resolution so that a sharp image is obtd. by setting the spacing between an image supporting means and developer carrying means at <=100mum, the frequency of an alternating magnetic field to be impressed at 700Hz-3.5kHz, the thickness of a developer layer at 8-80mum, and the average particle size of the developer at 8-16mum. CONSTITUTION:A developing roller 16 is disposed to face a photosensitive body 14 as an image support on which the electrostatic latent image is formed apart a 100mum spacing. The roller 16 and the photosensitive body 14 are respectively rotated in the directions of arrows A, B to form a developing region D. The toner T in a hopper 12 is supplied to this roller 16 and the alternating electric field of 700Hz-3.5kHz frequency is impressed between the roller 16 and the body 14 from an AC bias power supply 26. The thickness of the developer layer formed on the body 14 is set at 8-80mum and the average particle size of the toner T in the hopper 12 at 8-16mum. The fogging of the image formed on the body 14 and the degradation in the resolution thereof are prevented and the sharp image is obtd. |
