A process unit includes a rotatable image bearer, an optical writing head to expose the image bearer within an maximum exposure range in an axial direction of the image bearer, a developer bearer, spacers disposed in axial end portions of the image bearer to determine a position of the optical writing head relative to the image bearer and slidingly contact the image bearer, a cleaner disposed downstream from the developer bearer in an image bearer rotation direction, and a remover to slidingly contact the axial end portion of the image bearer to remove a substance adhering thereto. In the axial direction, inner ends of the spacers are positioned inside a toner layer range of the developer bearer extending beyond a largest sheet width. The remover is disposed downstream from the cleaner and crossing a line extending from the inner end of the spacer perpendicularly to the axial direction.

An image forming apparatus includes: a main body having an opening; a photoconductor unit including a photoconductor and removably mountable to the main body through the opening by moving the photoconductor unit in a first direction; an exposure member; and a moving mechanism configured to move the exposure member closer to and further from the photoconductor. The moving mechanism includes: a fixed shaft having an axial line thereof fixed relative to the main body; a first arm including one end portion thereof which is supported rotatably around the axial line of the fixed shaft; a movable shaft having an axial line thereof which is movable relative to the main body; and a second arm including: one end portion supporting the exposure member; and another end portion connected to the first arm via the movable shaft, and the second arm being swingable around the axial line of the movable shaft.

Disclosed is an image forming apparatus including: a photosensitive member unit having a photosensitive member; an exposure head configured to expose the photosensitive member, the exposure head being of an elongated shape in first directions; a developing unit having a developer bearing member; a support member configured to engage with either the photosensitive member unit or the developing unit and to guide the photosensitive member unit or the developing unit along the first directions; and a restricting portion configured to restrict a movement in the first directions of a movable member movably guided in the first directions by the support member.

An image formation apparatus according to an embodiment may include: an exposure unit configured, when a cover member is opened from a closed position to an open position, to move from a first position to a second position with respect to the cover member; and a lock mechanism. When the cover member is in the open position, the exposure unit is movable between the second position and a third position in which the angle of the exposure unit relative to the cover member is different from that in the second position. The lock mechanism locks a position of the exposure unit when the exposure unit is in the third position. The lock mechanism releases the lock of the position of the exposure unit, when the cover member is moved from the open position to the closed position in the state where the exposure unit is in the third position.

An optical scanning device includes a housing, a transmissive member, a linear member, a drive portion, a guide rail, a cleaning holder, a cleaning member, a detection portion, and a control portion. The detection portion includes a light emitter that emits light in a juxtaposition direction of the transmissive member and a light receiver that receives the light emitted from the light emitter. The cleaning holder includes a light blocking portion that is located, when the cleaning holder reaches one end part of a movement path thereof, between the light emitter and the light receiver so as to block the light emitted from the light emitter, with a gap formed between the light blocking portion and the housing. The housing includes a light leakage prevention portion formed between the light emitter and the light receiver.

An image forming apparatus includes: a rotatable photoconductor; an exposure portion including a substrate on which a plurality of chips each including a plurality of light emitting portions that emit light for exposing the photoconductor is mounted, and a support portion configured to support the substrate; a fan configured to generate an airflow for cooling the exposure portion; and a duct configured to communicate with the fan and to communicate with the support portion to guide the airflow generated by the fan to the substrate.

A scanning optical device includes a polygon mirror to deflect and scan a luminous flux emitted from a light source, an imaging lens and an optical box. The imaging lens is long in a scanning direction of the polygon mirror. The optical box is provided with the polygon mirror and the imaging lens. The optical box includes two positioning portions to position one end and the other end of the imaging lens in the scanning direction. In a position adjacent to one positioning portion of the two positioning portions in the scanning direction and on a side of the other positioning portion, an inclined surface is provided. The inclined surface extends in a direction from the one positioning portion toward the other positioning portion and inclines so as to lower in height as it goes to the other positioning portion from the one positioning portion.

A light-emitting device includes a base that is composed of a metal block that extends in a first direction, multiple light-emitting portions unaligned in the first direction and facing a front surface of the base, the multiple light-emitting portions including multiple light sources that extend in the first direction and that are supported by a support that extends in the first direction, and a handle that is formed below the front surface of the base and that is to be held by an operator with the base placed on a flat surface.

An image forming apparatus includes: a rotatable photoconductor; an exposure portion including a substrate on which a plurality of chips each including a plurality of light emitting portions that emit light for exposing the photoconductor is mounted, and a support portion configured to support the substrate; a fan configured to generate an airflow for cooling the exposure portion; and a duct configured to communicate with the fan and to communicate with the support portion to guide the airflow generated by the fan to the substrate.

A cover closes a first opening of a main box portion. A second opening is formed in a unit housing of an optical scanning unit to externally expose a connector mounted on an electronic board. The unit housing has a protruding inner frame portion and a wiring portion. The protruding inner frame portion protrudes from an outer surface of the unit housing and surrounds the second opening. The cover includes a protruding outer frame portion that protrudes from an inner surface of the cover and surrounds the protruding inner frame portion. A top portion of the protruding inner frame portion is formed along an inner-side portion of the protruding outer frame portion on an inner surface of the cover. A top portion of the protruding outer frame portion is formed along an outer-side portion of the protruding inner frame portion on the outer surface of the unit housing.