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.

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 photosensitive member, light-emitting chips, and a controller integrated circuit (IC). Provided in each of the light-emitting chips are a plurality of light-emitting units that emit light for exposing the photosensitive member, a circuit unit that turns on and off the plurality of light-emitting units based on image data, and a storage unit that stores control data indicating a target amount of light of the plurality of light-emitting units. The light-emitting chips are arranged along a rotational axis direction of the photosensitive member. Each of the light-emitting chips is connected to the controller IC by a different one of a plurality of signal lines. In a case where the output control data is transmitted from the controller IC to each of the light-emitting chips via the different one of the plurality of signal lines, the transmitted control data is stored in the storage unit.

An image forming apparatus includes a light-emitting chip, a substrate on which a plurality of light emitting chips are mounted, a controller, and a switch. The light-emitting chip includes a light-emitting portion, which emits light exposing a photosensitive drum surface based on supply of a driving current to the light-emitting portion, and a driving portion that drives the light-emitting portion. The controller controls the driving portion by transmitting a signal to the light-emitting chip and outputs a digital signal corresponding to a target amount of light of the light-emitting portion to the light-emitting chip. Based on a control signal from the controller, the switch switches a connection state between the voltage source and the D/A converter to a first state where the voltage source supplies the reference voltage to the D/A converter, and a second state where an electrical connection between the voltage source and the D/A converter is disconnected.

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 exposure head for forming an image of a first resolution corresponding to an arrangement interval of a plurality of lower electrodes in a crossing direction or an image of a second resolution lower than the first resolution. A circuit portion includes an image data storage portion that is arranged on the substrate together with a plurality of lower electrodes and converts input image data into image data according to the resolution. By this, the same exposure head can be used for both high resolution images and low resolution images without degrading the image quality.

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 exposure head for forming an image of a first resolution corresponding to an arrangement interval of a plurality of lower electrodes in a crossing direction or an image of a second resolution lower than the first resolution. A circuit portion 602 includes an image data storage portion 804 which is arranged on the substrate together with a plurality of lower electrodes and converts input image data into image data according to the resolution. By this, the same exposure head can be used for both high resolution images and low resolution images without degrading the image quality.

A weak light releasing layer includes a plurality of weak light releasing sections separated from each other by overlapping with corresponding one of the plurality of light releasing sections and a second inspection portion that is positioned relatively to the plurality of weak light releasing sections and overlaps with a first inspection portion. There are a first region and a second region that differ depending on whether or not there is an overlap with the second inspection portion inside an outer shape of the first inspection portion. The first region is sandwiched between any pair of portions of the second region in any of a plurality of directions orthogonal to each other.