| 摘要 |
<p>PURPOSE:To make an electrostatic charging member surely abut on a body to be electrostatically charged even in the case of applying a low pressing force, to stably and uniformly charge the body to be electrostatically charged and to obtain an image of high image quality having an excellent reproduction of a halftone image etc., without the occurrence of the melt-sticking of toner even in a contact electrostatic charging system. CONSTITUTION:The glass transfer temperature Tg of non-magnetic toner in one-component developer is 57 deg. to 67 deg., a mean number molecular weight Mn is 3700 to 5900, and an electrostatic charging roller 2 is constituted of a lower layer part 2b formed around a core bar 2a and on which a voltage is impressed through the core bar 2a and an upper layer part 2c formed around the lower layer part 2b and constituted of a high resistance, and the hardness of the electrostatic charging roller 2 is ASKER-C and <=60 deg.. Thus, the electrostatic charging roller 2 can surely abut on the photosensitive drum 1 as the body to be electrostatically charged even by the low pressing force, so that the photosensitive drum 1 is uniformly electrostatically charged, and then, the image of high image quality having the excellent reproduction of the halftone image can be obtained without the occurrence of the melt-sticking of the toner.</p> |
