An image forming apparatus comprising:
- an apparatus body;
- a photosensitive member;
- an exposing portion including:
- a plurality of light emitting elements arranged adjacent to the photosensitive member and aligned in a longitudinal direction of the photosensitive member, the light emitting elements being configured to emit light;
- and
- a lens array having a plurality of lenses configured to focus light emitted from the light emitting elements on a surface of the photosensitive member, the exposing portion being configured to expose the surface of the photosensitive member to form an electrostatic latent image;
- a developing apparatus configured to be detachably attached to the apparatus body, the developing apparatus being arranged adjacent to the exposing portion with respect to a width direction intersecting the longitudinal direction in a state attached to the apparatus body, and being configured to develop the electrostatic latent image on the photosensitive member into a toner image;
- a supporting portion configured to support the developing apparatus in an insertable and extractable manner along the longitudinal direction when attaching and detaching the developing apparatus to and from the apparatus body, the supporting portion including:
- a main body portion;
- and
- first and second rails that are disposed along the longitudinal direction on a surface facing the developing apparatus of the main body portion, the first rail being closer to the exposing portion in the width direction than the second rail is;
- a duct disposed on the developing apparatus and configured to allow air to flow in an inserting direction of the developing apparatus from an upstream side of the developing apparatus into a space surrounded by the developing apparatus, the main body portion, the first rail, and the second rail, in a state where the developing apparatus is attached to the apparatus body;
- a first sealing member configured to seal a space between a first surface of the duct and a second surface of the main body portion in a state where the developing apparatus is attached to the apparatus body, the first surface being located on a main body portion side of the duct, the second surface being located further upstream of an upstream end of the first rail and an upstream end of the second rail in the inserting direction;
- and
- a second sealing member disposed downstream of the first sealing member in the inserting direction and configured to seal a space between the first surface and the upstream end in the inserting direction of the first rail in the state where the developing apparatus is attached to the apparatus body.