Patent ID: 7596344

Claim:
An image forming apparatus, comprising: an image bearing member; and a charging unit configured to charge said image bearing member in a non-contact arrangement, said charging unit comprising a charging roller; wherein said charging roller and said image bearing member are provided so as to satisfy relations, 20 μm≦ G min ( C, E 1 , E 2), G max ( C, E 1 , E 2)≦80 μm, and G max− G min≦40 μm, where, representing by C, E 1 and E 2 several locations on an image forming region of said image bearing member such as a middle and respective ends, respectively, (i) Gmax (C), Gmax (E 1 ) and Gmax (E 2 ) are maxima of the charging gap at the respective locations in a change with a rotation of said image bearing member; (ii) Gmin (C), Gmin (E 1 ) and Gmin (E 2 ) are minima of the charging gap similarly at the respective locations; (iii) Gmax is a maximum among Gmax (C), Gmax (E 1 ) and Gmax (E 2 ); and (iv) Gmin is a minimum among Gmin (C), Gmin (E 1 ) and Gmin (E 2 ).