Process cartridge capable of suppressing filming and image forming apparatus with same

A process cartridge attachable to a body of an image forming apparatus, the process cartridge comprising:

• a rotatable latent image bearer;
• a rotatable electric charging member to electrically charge the surface of latent image bearer uniformly, the electric charging member contacting the surface of the latent image bearer to form an electric charging nip therebetween;
• and
• a cleaning unit to remove residual toner remaining on the latent image bearer after the toner image is transferred onto a transfer medium in the transfer process,
• wherein the latent image bearer, the electric charging device, and the cleaning unit are a single unit
• wherein a difference between the width of the electric charging nip in a direction of rotation at longitudinal ends of the latent image bearer and that at a longitudinal center thereof is larger than an amount of deformation of the latent image bearer generated during rotation at the longitudinal center thereof.

An image forming apparatus comprising:

• rotatable means for bearing a latent image on a surface thereof;
• electric charging means for electrically charging the surface of the latent image bearing means uniformly, the electric charging means forming an electric charging nip between the latent image bearing means and the electric charging means by rotatably contacting the surface of the latent image bearing means;
• means for writing and forming an electrostatic latent image on the surface of the latent image bearing means uniformly charged by the electric charging means;
• means for applying toner to and developing the electrostatic latent image borne on the latent image bearing means;
• means for transferring a toner image rendered visible by the toner adhering to the latent image bearing means onto a transfer medium in a transfer process;
• means for removing residual toner remaining on the latent image bearing means after the toner image is transferred onto the transfer medium in the transfer process;
• and
• means for removing foreign substances adhering to the surface of the electric charging means,
• wherein a difference between the width of the electric charging nip in a direction of rotation at longitudinal ends of the latent image bearing means and that at a longitudinal center thereof is larger than an amount of deformation of the latent image bearing means generated at a longitudinal center thereof, and
• wherein a difference between the width of the electric charging nip in the direction of rotation at the longitudinal ends of the latent image bearing means and that at the longitudinal center thereof is larger than an amount of deformation of the latent image bearing means generated during rotation at the longitudinal center thereof.