An image forming apparatus includes: an exposure head including a first light emitting chip, a second light emitting chip, a first lens fixed to a housing at a position facing the first light emitting chip, and configured to form an image of light emitted from a plurality of light emitting portions included in the first light emitting chip on a photoreceptor, and a second lens provided separately from the first lens, fixed to the housing at a position facing the second light emitting chip, and configured to form an image of light emitted from a plurality of light emitting portions included in the second light emitting chip on the photoreceptor; and a controller capable of controlling application of a voltage to each of a plurality of electrodes of the first light emitting chip and a plurality of electrodes of the second light emitting chip so as to form one pixel.

An image forming apparatus includes an apparatus cover, first and second exposure units, and an orientation setting mechanism. The apparatus cover opens or closes by pivoting about a rotation fulcrum with respect to an apparatus body. The first exposure unit is disposed at a first position, on an inner surface, spaced apart from the rotation fulcrum. The second exposure unit is disposed at a second position, on the inner surface, closer than the first position to the rotation fulcrum. The orientation setting mechanism sets an orientation of the first exposure unit to a first direction approaching the apparatus body in a closed state. The orientation setting mechanism sets it to a second direction further away than the first direction from the rotation fulcrum and sets the orientation of the second exposure unit to a third direction between the first and second directions when the opening angle is a first angle.

An image formation apparatus according to an embodiment may include: an image formation unit; an apparatus main body including therein the image formation unit; a cover rotatable about a first rotation axis to open and close the apparatus main body; an exposure unit including an exposure head; and a holding member fixed to an inner surface of the cover and holds the exposure unit. The holding member includes a first support portion at a side of the holding member closer to the first rotation axis and a second support portion at a side of the holding member farther from the first rotation axis. The first support portion supports the exposure unit to be rotatable, about a second rotation axis parallel to the first rotation axis, and the second support portion supports the exposure unit to be swingable in directions closer to and away from the inner surface of the cover.

An exposure apparatus includes: a substrate that extends in a longitudinal direction intersecting with a gravity direction and has light emitting elements emitting light toward a gravity direction; a housing that extends in the longitudinal direction, to which the substrate is attached; a support section that supports both end side portions of the housing in the longitudinal direction against gravity; and a structure section having a weight that is attached to an intermediate portion of the housing in the longitudinal direction and supported by the support section in the gravity direction.

An image forming apparatus includes a photoconductor, a light emitting substrate, and imaging optical systems, wherein an optical axis of the imaging optical systems are parallel, imaging magnifications of the imaging optical systems are substantially equal for the light emitting point groups, the imaging optical systems includes a first lens array, a second lens array, and apertures, central points of the light emitting point group exist in a first plane, central points of the imaging lenses exist in a second plane, central points of the apertures exist in a third plane, central points of the imaging lenses exist in a fourth plane, the first plane forms a non-zero predetermined angle with respect to a plane perpendicular to an optical axis direction, and the angle formed with respect to the plane perpendicular to the optical axis direction is greater in the order of the first, second, third, and the fourth plane.

A printing apparatus is provided. The apparatus comprises a light-emitting element, a light-receiving element including a first terminal and a second terminal, a reference current generator supplying a reference current, a comparator comparing a monitor current with the reference current, the light-receiving element supplying the monitor current to the second terminal in accordance with a light emission amount, a driver driving the light-emitting element based on an output of the comparator, and a reference voltage controller. The comparator includes a first input terminal connected to the second terminal and a second input terminal. The reference voltage controller supplies a reference voltage selected from at least two voltage values to the second input terminal, and to control the voltage of the second terminal to be a voltage according to the reference voltage.

An exposure apparatus includes: a substrate that, extends in a longitudinal direction intersecting with a gravity direction and has light emitting elements emitting light, toward a gravity direction; a housing that extends in the longitudinal direction, to which the substrate is attached; a support section that supports both end side portions of the housing in the longitudinal direction against gravity; and a structure section having a weight that is attached to an intermediate portion of the housing in the longitudinal direction and supported by the support section in the gravity direction.

An image formation apparatus according to an embodiment may include: an image formation unit; an apparatus main body including therein the image formation unit; a cover rotatable about a first rotation axis to open and close the apparatus main body; an exposure unit including an exposure head; and a holding member fixed to an inner surface of the cover and holds the exposure unit. The holding member includes a first support portion at a side of the holding member closer to the first rotation axis and a second support portion at a side of the holding member farther from the first rotation axis. The first support portion supports the exposure unit to be rotatable, about a second rotation axis parallel to the first rotation axis, and the second support portion supports the exposure unit to be swingable in directions closer to and away from the inner surface of the cover.

An image forming apparatus includes an apparatus cover, first and second exposure units, and an orientation setting mechanism. The apparatus cover opens or closes by pivoting about a rotation fulcrum with respect to an apparatus body. The first exposure unit is disposed at a first position, on an inner surface, spaced apart from the rotation fulcrum. The second exposure unit is disposed at a second position, on the inner surface, closer than the first position to the rotation fulcrum. The orientation setting mechanism sets an orientation of the first exposure unit to a first direction approaching the apparatus body in a closed state. The orientation setting mechanism sets it to a second direction further away than the first direction from the rotation fulcrum and sets the orientation of the second exposure unit to a third direction between the first and second directions when the opening angle is a first angle.

An exposure device according to an embodiment may include: a holding member provided with a reference surface; an optical system being in contact with the reference surface and slidable in a first direction parallel to the reference surface; and a board including a light emitting element and being fixed to the holding member such that the optical system is sandwiched between the reference surface and the board.