An exposure device according to an embodiment includes: a substrate in which light-emitting elements are mounted; an optical system which converges light emitted from the light-emitting elements; a holding member includes a holding member body which holds the substrate and the optical system, and a cut fringe projected from the holding member body; and a support member provided at a predetermined position in the holding member between the substrate and the optical system. The support member is formed of a cured agent attached to a shear surface of the cut fringe of the holding member, and the support member includes a contact surface with which the substrate is in contact.

An exposure apparatus comprises an exposure head, a memory and at least one processor. The exposure head includes light-emitting elements, and a rod lens array. A photosensitive body is rotationally driven. The light-emitting elements are arranged in a direction intersecting a direction of rotation of the photosensitive body. The rod lens array forms an image of light on the photosensitive body. The light is outputted from any of the light-emitting elements based on image data, passes through the rod lens array and reaches the photosensitive body. The memory stores correction data for correcting a streak image. The at least one processor corrects the image data based on the correction data read out from the memory.

A print head includes: current-driven non-single crystal light emitting elements arranged in a line; thin film transistors that are provided in one-to-one correspondence with the light emitting elements and each supplies a driving current to a corresponding one of the light emitting elements; a detector that detects, when one of the light emitting elements corresponding to one of the thin film transistors emits light, an output voltage of the one of the thin film transistors; and a hardware processor that determines a control voltage to be applied to each of the thin film transistors when next light is emitted according to the output voltage of the one of the thin film transistors detected by the detector and a driving current to be supplied by each of the thin film transistors to cause each of the light emitting elements to emit light with a target light amount.

Provided is an organic light-emitting device capable of outputting light with high efficiency and high luminance. The organic light-emitting device includes an anode, a cathode, an emission layer placed between the anode and the cathode, and an organic compound layer placed between the anode and the emission layer, in which the organic compound layer contains the following compound A and compound B: [Compound A] an organic compound free of a nitrogen atom and a metal atom, the compound having SP.sup.2 carbon atoms and SP.sup.3 carbon atoms, and having a ratio of the number of the SP.sup.3 carbon atoms to the number of the SP.sup.2 carbon atoms of 40% or more; and [Compound B] a compound having a tertiary amine structure.

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

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 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.

This disclosure provides an organic electroluminescence device having an anode, a cathode, and an organic compound layer which is disposed between the anode and the cathode and has a light-emitting layer and an organic functional layer, in which the organic functional layer contains an organic compound represented by the following general formula (1) or (2) and a transition metal having a work function of 4.4 eV or more,

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An optical writing device adopting a low cost and simple structure can obtain temperatures of light emitting elements. The device comprises a plurality of light emitting elements arranged linearly in a main scanning direction. The amount of light emitting of the light emitting elements changes by self-generated heat. The light emitting elements are divided into a plurality of groups. Each of the groups includes a prescribed number of light emitting elements. The device comprises a control unit for calculating the amount of heat generation of the light emitting elements for each of groups from clock time t0 to clock time t0+t. The control unit calculates the temperature for each of the groups at the clock time t0+t, based on the amount of heat generation from the clock time t0 to the clock time t0+t and the temperature at the clock time t0.

An optical writing device performing optical writing onto a photoreceptor, including: a light-emitting unit including a plurality of light-emitting elements that form a plurality of element rows spaced from one another in a sub scanning direction, each of the light-emitting elements having a main scanning direction position differing from a main scanning direction position of any other one of the light-emitting elements; a plurality of signal output units, one for each element row, each outputting a light amount signal for each light-emitting element in a corresponding element row, each light amount signal indicating an amount of light to be emitted by a corresponding light-emitting element; and a plurality of drive units, one for each light-emitting element, each, when receiving a light amount signal for a corresponding light-emitting element, supplying a drive current in accordance with the light amount signal to the corresponding light-emitting element.