Image forming apparatus having development apparatus including sheet member which is disposed below position on developer bearing member where developer bearing member is closest to image bearing member

An image forming apparatus comprising:

• an image bearing member on which an electrostatic latent image is formed;
• an exposure apparatus configured to expose the image bearing member to light to form the electrostatic latent image on the image bearing member;
• a development apparatus including a development container, a developer bearing member, a magnet, and a regulation blade,
• wherein the development container is configured to accommodate a developer including a toner and a carrier,
• wherein the developer bearing member is rotatable and configured to bear and convey the developer to develop the electrostatic latent image formed on the image bearing member,
• wherein the magnet is non-rotatably and fixedly disposed in the developer bearing member and configured to generate a magnetic field to allow the developer bearing member to bear the developer, and
• wherein the regulation blade is disposed below a position on the developer bearing member where the developer bearing member is closest to the image bearing member, so as to face the developer bearing member in non-contact with the developer bearing member, and is configured to regulate an amount of the developer born by the developer bearing member;
• a sheet member disposed below the position on the developer bearing member where the developer bearing member is closest to the image bearing member and in contact with the image bearing member, wherein the sheet member is configured to cover at least a part of a space partitioned by the regulation blade, the developer bearing member, and the image bearing member;
• a drive unit configured to rotatably drive the developer bearing member;
• and
• a controller configured to control the drive unit to rotatably drive the developer bearing member in a first direction during image forming,
• wherein, during non-image forming, the controller executes a control mode for controlling the drive unit to rotatably drive the developer bearing member in a second direction opposite to the first direction, and then rotatably drive the developer bearing member in the first direction, and
• wherein a part of the sheet member above a horizontal line passing through a tip of the regulation blade exists at a position in contact with a magnetic brush on the developer bearing member by the magnet in a case where the drive unit rotatably drives the developer bearing member in the second direction in the control mode, and at a position in non-contact with the magnetic brush on the developer bearing member by the magnet in a case where the drive unit rotatably drives the developer bearing member in the first direction during image forming.