An exposure head includes a plurality of light emitting element array chips each having light emitting portions and a wire bonding pad. The plurality of light emitting element array chips are arranged in a staggered manner in a longitudinal direction of a printed-circuit board. One end portion of a first light emitting element array chip overlaps one end portion of a second light emitting element array chip when viewed in a width direction. Another end portion of the second light emitting element array chip overlaps one end portion of a third light emitting element array chip when viewed in the width direction. An adhesive for fixing the second light emitting element array chip to the printed-circuit board is applied in an area between the one end portion of the first light emitting element array chip and the one end portion of the third light emitting element array chip.

In a configuration in which a metal holder is supported by a resin member, the metal holder cannot be grounded, so that electricity may be discharged from the charged holder to a substrate held by the holder. The holder is provided with a pin to determine a position of the holder with respect to a photosensitive member. A conductive member that is made of metal and is grounded, is brought into contact with the pin to thereby enable the holder to be grounded through the pin.

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.

An optical writing device includes: an image carrier; an exposer that exposes a curved surface of the image carrier; and a control circuit that controls the exposer, wherein the exposer includes a plurality of light-emitting element groups having different positional relationships from one another with the image carrier, and has a configuration that is adjusted in accordance with at least one of an angle at which light reaching the curved surface of the image carrier from each light-emitting element group enters the image carrier, and a distance of each light-emitting element group from the image carrier.

An image forming apparatus includes: a photoconductor that rotates about a first axis; an exposure portion that includes a substrate that includes a plurality of light emitting portions for exposing a surface of the photoconductor, and a support portion for supporting the substrate, and that moves between an exposure position where the photoconductor is exposed and a retracted position where the photoconductor is retracted from the exposure position; and a rotational member that has a second axis along the first axis, and that moves the exposure portion between the retracted position and the exposure position by rotation about the second axis.

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.

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 organic compound represented by formula [1]:

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where R.sub.1 to R.sub.14 are each independently selected from the group consisting of a hydrogen atom and substituents, wherein at least one of R.sub.1 to R.sub.4 and R.sub.8 to R.sub.11 is an amino group or an amino group-containing group, and X is oxygen, sulfur, selenium, tellurium, or a CR.sub.15R.sub.16 group, wherein R.sub.15 and R.sub.16 are each independently selected from the group consisting of a hydrogen atom and substituents.

An exposure head includes a plurality of light emitting element array chips each having light emitting portions and a wire bonding pad. The plurality of light emitting element array chips are arranged in a staggered manner in a longitudinal direction of a printed-circuit board. One end portion of a first light emitting element array chip overlaps one end portion of a second light emitting element array chip when viewed in a width direction. Another end portion of the second light emitting element array chip overlaps one end portion of a third light emitting element array chip when viewed in the width direction. An adhesive for fixing the second light emitting element array chip to the printed-circuit board is applied in an area between the one end portion of the first light emitting element array chip and the one end portion of the third light emitting element array chip.

A cleaning member that is used in an image forming apparatus and that is inserted from outside the image forming apparatus, the apparatus including a holding body that holds a substrate on which light emitting elements that expose a photosensitive drum are aligned and that holds lenses, the cleaning member including a rod-shaped rhabdoid formed of resin, a cleaning portion provided in the rhabdoid to clean a light emission surface of each lens, the cleaning portion moving together with the rhabdoid inserted in the image forming apparatus and opposing the light emission surface in an optical axis direction of the lens, and a magnet provided on the rhabdoid, the magnet emitting magnetic force that generates force drawing the holding body thereto so that the cleaning portion continues to contact the light emission surface.