Image forming apparatus

An image forming apparatus comprising:

• a photoreceptor;
• a charger configured to charge a specified electric potential on a surface of the photoreceptor;
• an optical scanning device configured to emit a light beam to expose the surface of the photoreceptor charged by the charger to form an electrostatic latent image on the surface of the photoreceptor;
• a developing device configured to develop the electrostatic latent image formed by the optical scanning device to form a toner image on the surface of the photoreceptor;
• a transfer member configured to transfer the toner image formed by the developing device to a sheet and for feeding the sheet;
• a fixing device configured to apply heat and pressure to the sheet fed from the transfer member to fix the toner image on the sheet;
• and
• a control unit configured to control an exposure amount from the optical scanning device, wherein:
• for formation of an image having a pattern with a spatial frequency within a range from 0.1 c/mm to 3.0 c/mm, the control unit is configured to carry out exposure amount control such that an exposure amount on an edge portion of the pattern becomes higher than an exposure amount on a non-edge portion of the pattern by a first exposure amount so that after the exposure, an electric potential at the edge portion of the pattern will be different from an electric potential Vi at the non-edge portion of the pattern by a first voltage V1 and such that an exposure amount on an edge-surrounding portion of a non-image area adjoined to the edge portion of the pattern becomes higher than an exposure amount on portions of the non-image area other than the edge-surrounding portion by a second exposure amount so that after the exposure, an electric potential at the edge-surrounding portion of the non-image area will be different from an electric potential Vo at the other portions of the non-image area by a second voltage V2 that is larger than the first voltage V1.