Image forming apparatus having grid electrode with opening and non-opening portions

An image forming apparatus comprising:

• a rotatable photosensitive member;
• a corona charger including a discharging wire and a plate-like grid electrode and being configured to charge a surface of said photosensitive member at a charging position;
• and
• an exposure device configured to expose the surface of said photosensitive member charged by said corona charger at an exposure position, which is at a downstream side of said corona charger in a rotational direction of said photosensitive member at the charging position, to form an electrostatic image,
• wherein said grid electrode includes a first portion having a plurality of openings and a second portion provided adjacent to said first portion with respect to the rotational direction, said second portion including a downstream side peripheral portion not provided with an opening in a charging region in a longitudinal direction of said corona charger, and
• wherein in a cross-section orthogonal to the longitudinal direction and including the charging region, the downstream side peripheral portion extends from a downstream end portion of said plate-like grid electrode at least to a position crossing with a straight line A passing through the exposure position and said discharging wire.