Image forming apparatus

An image forming apparatus comprising:

• a plurality of image carrier members each configured to carry a latent image;
• a plurality of electrostatic chargers each configured to charge the image carrier member uniformly;
• a plurality of developing devices each configured to develop the latent image formed on the image carrier member by toner and collecting the toner on the image carrier member;
• an intermediate transfer member having a non-electroconductive material on which a developed image is transferred by one of the image carrier members and then another developed image is transferred over the developed image by another image carrier member;
• a plurality of transfer rollers each provided so as to oppose the image carrier member with the intermediary of the intermediate transfer member;
• a first roller provided on the upstream side in the direction of travel of the intermediate transfer member;
• and
• a second roller provided on the downstream side in the direction of travel of the intermediate transfer member,
• wherein the intermediate transfer member satisfies conditions of σ50>2.0×1010 (Ω/□), ρ500·d>1.0×104 (Ω·m2), and ρ50/(Dst/V)<4.0×1011 (Ω·m/sec) where Dst is a distance (m) between the adjacent image carrier members, V is a traveling velocity (m/sec) of the intermediate transfer member, d is a thickness (m) of the intermediate transfer member, σ50 is a surface resistivity measured with an applied voltage of 50V, ρ500 is a volume resistivity measured with an applied voltage of 500V, and ρ50 is a volume resistivity measured with an applied voltage of 50V.

An image forming apparatus comprising:

• a plurality of image carrier members each configured to carry a latent image;
• a plurality of electrostatic chargers each configured to charge the image carrier member uniformly by applying DC bias;
• a plurality of developing devices each configured to develop the latent image formed to the image carrier member by toner;
• a plurality of cleaners each configured to remove the toner remaining on the carrier member;
• an intermediate transfer member having a non-electroconductive material on which a developed image is transferred by one of the image carrier members and then another developed image is transferred over the developed image by another image carrier member;
• a plurality of transfer rollers each provided so as to oppose the image carrier member with the intermediary of the intermediate transfer member;
• a roller provided on the upstream side in the direction of travel of the intermediate transfer member;
• and
• a second roller provided on the downstream side in the direction of travel of the intermediate transfer member,
• wherein the intermediate transfer member satisfies conditions of σ50>2.0×1010 (Ω/□), ρ500·d>3.0×103 (Ω·m2), and ρ50/(Dst/V)<4.0×1011 (Ω·m/sec) where Dst is a distance (m) between the adjacent image carrier members, V is a traveling velocity (m/sec) of the intermediate transfer member, d is a thickness (m) of the intermediate transfer member, σ50 is a surface resistivity measured with an applied voltage of 50V, ρ500 is a volume resistivity measured with an applied voltage of 500V, and ρ50 is a volume resistivity measured with an applied voltage of 50V.