An image forming apparatus includes a housing having an opening, a cover movable between an open position and a closed position, a first photoconductive drum and a second photoconductive drum, a first exposing head having a first boss and rotatably coupled to the cover, a second exposing head having a second boss and rotatably coupled to the cover, and a cam rotatably coupled to each of the first exposing head and the second exposing head. The cam is configured to rotate each of the first exposing head and the second exposing head. The cam includes (i) a first elongated hole into which the first boss fits and extending a direction intersecting a movement direction in which the cam moves and (ii) a second elongated hole into which the second boss fits and extending in a direction intersecting the movement direction of the cam.

A light-emitting device includes: a first light- emitting unit that extends in one direction and has a first emission surface located along the one direction, the first emission surface emitting light; a second light-emitting unit that is located in the one direction with respect to the first light-emitting unit, that extends in the one direction, and that has a second emission surface located along the one direction, the second emission surface emitting light; a first cleaning unit that is capable of moving in the one direction and an opposite direction that is opposite to the one direction to clean the first emission surface; a second cleaning unit that is capable of moving in the one direction and the opposite direction to clean the second emission surface; and a transmission unit that extends from the first cleaning unit and the second cleaning unit in the one direction and that transmits a moving force for moving the first cleaning unit and the second cleaning unit to the first cleaning unit and the second cleaning unit.

A light emitting device 401 includes a silicon substrate and a light emitting region including a lower electrode, a light emitting layer, and an upper electrode, and an exposure head is provided with a printed board on which light emitting devices 401 are arranged in a staggered form and a circuit portion 602 for controlling, on the basis of image data, a voltage of each of electrodes included in the lower electrode so that the light emitting device layer emits light and is for forming an image with a resolution corresponding to an arrangement interval of the lower electrode with respect to a crossing direction, and the circuit portion 602 is disposed together with the light emitting region on the silicon substrate. Costs on wire bonding and an area of a wiring board can be suppressed.

A light emitting device 401 includes a silicon substrate and a light emitting region including a lower electrode, a light emitting layer, and an upper electrode, and an exposure head is provided with a printed board on which light emitting devices 401 are arranged in a staggered form and a circuit portion 602 for controlling, on the basis of image data, a voltage of each of electrodes included in the lower electrode so that the light emitting device layer emits light and is for forming an image with a resolution corresponding to an arrangement interval of the lower electrode with respect to a crossing direction, and the circuit portion 602 is disposed together with the light emitting region on the silicon substrate. Costs on wire bonding and an area of a wiring board can be suppressed.

A light emitting device includes a first light-emitting-element row that includes light emitting elements arranged in a row in a main scanning direction and a second light-emitting-element row that includes light emitting elements arranged in a row in the main scanning direction and that is positioned in such a manner that at least a portion of the second light-emitting-element row overlaps the first light-emitting-element row in a sub scanning direction. The first and second light-emitting-element rows are each formed by arranging light-emitting-element array chips in each of which the light emitting elements are arranged in a row in the main scanning direction. In each of the light-emitting-element array chips, a pitch of the light emitting elements arranged in a row is changed from a first pitch to a second pitch, which is different from the first pitch, in a central region of the row of the light emitting elements.

A focus adjustment mechanism for adjusting a focus position of a printhead includes a rotatable pin that is rotatable around a pin axis. The rotatable pin includes a cam section located having a surface whose radial distance from the pin axis varies around its perimeter, and a gripping feature. An adjustment plate includes a gripping feature and is adapted to fit over and engage with the gripping feature of the rotatable pin such that the adjustment plate rotates together with the rotatable pin. A fastener fastens the adjustment plate to a support structure when the adjustment plate is positioned in a desired orientation. The printhead includes a frame feature which is pulled firmly against the cam section of the rotatable pin such that as the rotatable pin is rotated the frame feature rides on the surface of the cam section thereby adjusting the focus position of the printhead.

An exposure head includes a light emitter, a plurality of switches, a transmission line, and a plurality of delay circuits. In the light emitter, a plurality of light emitting elements are arranged in a first direction. The switches are provided respectively corresponding to the light emitting elements. The switches are configured to perform switching such that, when a drive signal is input, a drive current flows through a light emitting element corresponding to the drive signal. The transmission line is configured to supply a drive signal to the switches. The delay circuits are provided respectively corresponding to the switches. The delay circuits are configured to delay the drive signal that is supplied to the switches through the transmission line in order from a first end side to a second end side of the light emitting elements arranged in the first direction.

A light emitting device includes: a base plate extending in a first direction; a plurality of light emitting units arranged over a front surface of the base plate while being shifted from each other in the first direction, and each including a support body extending in the first direction and a plurality of light sources supported on the support body while being arranged in the first direction; a flow path disposed on a side of the base plate opposite to a side facing the light emitting units to feed air therethrough in the first direction; and a wire electrically connected to at least one of the plurality of the light emitting units, and disposed inside the flow path.

A light emitting device includes a light emitting unit in which a resin housing extending in one direction holds a light emitting element emitting light in a light emitting direction intersecting the one direction, a suppressing member that extends in the one direction and suppresses deformation of the housing caused by heat, the suppressing member having a linear expansion coefficient different from a linear expansion coefficient of the housing, and a fixing portion that fixes the housing and the suppressing member to each other at a position overlapping, in the light emitting direction, a neutral axis of the housing or the light emitting unit or a neutral axis of the suppressing member in the light emitting direction, at plural places separated away from each other in the one direction or in a state of extending in the one direction.

A cleaning rod includes a rod-like member, a slidable portion which is provided on a free end side of the rod-like member with respect to a direction in which the cleaning rod is inserted and which is slidable on a light emergent surface of a lens of an image forming apparatus, and a restricting portion configured to restrict movement of the slidable portion in a direction away from the light emergent surface with respect to an optical axis direction by contacting the holder at each of free ends of opposing wall portions of a holder of the image forming apparatus from a side opposite from a side where a photosensitive member of the image forming apparatus is provided with respect to the optical axis direction in a state in which the slidable portion contacts the light emergent surface.