An exposure head configured to expose a photoreceptor includes a substrate having a plurality of light emitting portions, a lens array having a plurality of lenses that condense light emitted from the light emitting portions onto the photoreceptor, and a holder that holds the substrate and the lens array. The holder has an opposing surface including an opening into which the lens array is inserted and facing the photoreceptor in an optical axis direction of the lens. The opposing surface has a contacting surface on which a cleaning rod cleaning a light exit surface of the lens array abuts. The holder includes a sealing agent that seals a gap between a side wall of the lens array and an edge of the opening along a longitudinal direction of the holder, and a groove formed in the opposing surface between the opening and the contacting surface. The sealing agent is applied between the groove and the side wall.

A printing head and a method for applying a correction for mounting deviation of light-emitting chips are provided. The printing head includes a plurality of light-emitting chips. Each light-emitting chip includes a plurality of primary light-emitting elements that are continuously arranged. At least one of two adjacent light-emitting chips further includes at least one spare light-emitting element continuously and linearly arranged after the primary light-emitting elements. If the two adjacent light-emitting chips are both at a target mounting position, first N light-emitting units of one of the two light-emitting chips respectively face to first N light-emitting units of the other one of the two light-emitting chips, where N≥1. Each two of the light-emitting units facing to each other form a group. One of the two light-emitting units in each of the groups is set to a light emission disabled state.

An image forming apparatus, having a housing with an opening, an openable/closable cover, a hinge supporting the openable/closable cover pivotably, LED units including LED heads, a first enhancing member, a second enhancing member, and a link member, is provided. The LED units are supported by the openable/closable cover. The first enhancing member, the second enhancing member, and the link member are attached to an inner surface of the openable/closable cover. The first enhancing member and the second enhancing member are located on one side and the other side, respectively, of the openable/closable cover in a first direction being parallel to a pivot axis of the hinge and extend in a second direction. The link member links the first enhancing member and the second enhancing member at a position farther from the hinge than one of the LED units located closest to the hinge in the second direction.

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.

According to an embodiment, a print head includes one or more light emitting element arrays, a light emission control circuit, and one or more drive circuit arrays. The light emitting element arrays include a plurality of light emitting elements arrayed continuously along a main scanning direction. The light emission control circuit outputs drive signals of different phases in units of a light emitting element group configured by a predetermined number of continuous light emitting elements included in the light emitting elements. The drive circuit arrays include a plurality of drive circuits, the drive circuits cause the light emitting elements to emit light individually based on the drive signals.

A light-emitting device includes a first connection wire and a second connection wire each connecting a first power supply wire and a second power supply wire, a second lead wire between the first connection wire and the second connection wire, and first lead wires including a first lead wire located opposite to the second lead wire from relative to the first connection wire. The first lead wires are parallel to one another and include first connection pads as first connections at ends connected to first signal wires. The second lead wire includes a second connection pad as a second connection at an end connected to a second signal wire. A distance between the second connection pad and a first connection pad of the first connection pads adjacent to the second connection pad is greater than a distance between adjacent ones of the first connection pads.

An image forming apparatus includes: a rotatable image carrier on an outer circumferential surface of which an image is to be formed and that is movable in a rotation axis direction between an image forming position and a maintenance position; a light-emitting unit including a base member extending in the rotation axis direction of the image carrier, and plural light-emitting devices provided on the base member and configured to apply light to the outer circumferential surface of the image carrier, the light-emitting unit being configured to move together with the image carrier in the rotation axis direction; and a supporting unit configured to move together with the image carrier in the rotation axis direction and to support the light-emitting unit when the image carrier and the light-emitting unit are at the maintenance position and the light-emitting unit is disabled from being positioned with respect to the image carrier.

An exposure device includes: at least one light emitter that includes a substrate and a light-emitting device disposed on the substrate; and a position adjuster that includes a contact member having an outer periphery in contact with the substrate, a support member that rotatably supports the contact member, and at least one mover that is in contact with the support member to move the support member in a light emission direction of the light emitter.

An image forming apparatus includes a first image forming unit including a rotatable first image carrier and a first light-emitting unit, the first light-emitting unit including a first base member and plural first light-emitting devices, the first base member extending in an axial direction of the first image carrier, the plural first light-emitting devices being provided on the first base member and being configured to apply light to an outer circumferential surface of the first image carrier; and a second image forming unit including a rotatable second image carrier and a second light-emitting unit, the second light-emitting unit including a second base member and plural second light-emitting devices, the second base member extending in an axial direction of the second image carrier, the plural second light-emitting devices being provided on the second base member and being configured to apply light to an outer circumferential surface of the second image carrier. A direction of detaching and attaching of the first light-emitting unit from and to the first image forming unit and a direction of detaching and attaching of the second light-emitting unit from and to the second image forming unit are different from each other.

A light emitting device includes: a member having a first surface facing in one direction and a second surface facing an opposite side to the first surface; a light emitter that is disposed at the first surface, generates heat due to light emission, and has a lower stiffness than the member; and a heater that is disposed at the second surface of the member, and heats the member from the second surface.