A light emitting device in which light emitting elements are arranged on a surface of a substrate is provided. Each of the light emitting elements comprises a light emitting layer, a reflective layer arranged between the light emitting layer and the surface, a first electrode arranged between the reflective layer and the light emitting layer, an optical distance adjustment layer arranged between the reflective layer and the first electrode, an insulating layer covering a peripheral portion of the first electrode and arranged, between two light emitting elements adjacent to each other, between the optical distance adjustment layer and the light emitting layer, and a conductive plug extending from the insulating layer to pass through the optical distance adjustment layer and reach a height of an upper surface of the reflective layer while being in electrical contact with the first electrode.

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: a photoconductor; a charging portion that charges a surface of the photoconductor; an exposure portion including a substrate including a plurality of light emitting portions for exposing the photoconductor; a developing portion that develops a latent image formed on the surface of the photoconductor with toner; a fan that generates an airflow for cooling the exposure portion; and a duct that communicates with the fan and communicates with the support portion, the duct guiding the airflow generated by the fan to the substrate; in which a part of the duct is formed by a charging support portion that supports the charging portion, a developing support portion that supports the development, and a duct portion, and a space between the duct portion and the charging support portion and a space between the duct portion and the developing support portion are sealed by a sealing member.

An image forming device according to an embodiment includes a photosensitive drum and a light-emitting unit with a plurality of light-emitting elements which form an electrostatic latent image on the photosensitive drum. A processor controls a storage unit to store a cumulative light emission time of each light-emitting element. The processor further controls the storage unit to store an adjustment time which is shorter than a longest cumulative light emission time of the light-emitting elements. When a predetermined condition is satisfied, the processor controls at least one of the light-emitting elements that has a cumulative light emission time which is shorter than the adjustment time to emit light until the cumulative light emission time thereof equals the adjustment time.

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.

According to one embodiment, there is provided a print head including a transparent substrate, light-emitting elements, a lens, and a member. The transparent substrate includes a first surface and a second surface. The light-emitting elements are on the first surface of the transparent substrate. The lens condenses the irradiation light from the light-emitting elements that is transmitted through the first surface and the second surface, onto an object. The member is a member for preventing a part of reflected light of the irradiation light from being incident again on the incident surface of the lens.

An optical print head including light emitting elements, drivers, setters, a detector, and a generator. The detector is for detecting a noise component superimposed on a luminance signal, on transmission circuitry for transmitting the luminance signal from a setter to a driver, in a state in which the setter is outputting the luminance signal. The generator, for each light emitting element due to emit light in a line subsequent to a line for which the detector detected the noise component, generates and causes a setter corresponding to the light emitting element to output an adjusted luminance signal such that the light emitting element emits a light emission amount according to image data in a state in which the noise component detected by the detector is to superimposed on the adjusted luminance signal.

An exposure head includes a light emitting board group, a first lens array, and a second lens array. The light emitting board group disposes a plurality of light emitting boards each including a plurality of light emitting elements disposed side by side in a second direction intersecting with the first direction. The plurality of light emitting boards are disposed along the second direction and alternately in the first direction. The light emitting board group includes a first light emitting board group and a second light emitting board group. The first lens array condenses light emitted from the plurality of light emitting elements disposed on the first light emitting board group onto the surface of the image bearing member. The second lens array condenses light emitted from the plurality of light emitting elements disposed on the second light emitting board group onto the surface of the image bearing member.

An image forming apparatus includes: a photoconductor; a charging portion that charges a surface of the photoconductor; an exposure portion including a substrate including a plurality of light emitting portions for exposing the photoconductor; a developing portion that develops a latent image formed on the surface of the photoconductor with toner; a fan that generates an airflow for cooling the exposure portion; and a duct that communicates with the fan and communicates with the support portion, the duct guiding the airflow generated by the fan to the substrate; in which a part of the duct is formed by a charging support portion that supports the charging portion, a developing support portion that supports the development, and a duct portion, and a space between the duct portion and the charging support portion and a space between the duct portion and the developing support portion are sealed by a sealing member.

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.