A focus adjustment mechanism for adjusting a focus position of a printhead includes a rotatable pin that is rotatable around a pin axis. The rotatable pin includes a cam section located having a surface whose radial distance from the pin axis varies around its perimeter, and a gripping feature. An adjustment plate includes a gripping feature and is adapted to fit over and engage with the gripping feature of the rotatable pin such that the adjustment plate rotates together with the rotatable pin. A fastener fastens the adjustment plate to a support structure when the adjustment plate is positioned in a desired orientation. The printhead includes a frame feature which is pulled firmly against the cam section of the rotatable pin such that as the rotatable pin is rotated the frame feature rides on the surface of the cam section thereby adjusting the focus position of the printhead.

Provided is an organic electroluminescence element improved in emission efficiency. The organic electroluminescence element includes: a reflective electrode; a light exiting side electrode; an emission layer provided between the reflective electrode and the light exiting side electrode; and at least one low-refractive index layer provided between the reflective electrode and the emission layer, the low-refractive index layer having a refractive index lower than the refractive index of the emission layer. An optical path L.sub.1 between the maximum emission surface of the emission layer and the reflection surface of the reflective electrode, and an optical path L.sub.2 between the reflection interface on an emission layer side of the low-refractive index layer and the maximum emission surface of the emission layer satisfy specific expressions.

An optical scanning device includes a housing, a transmissive member, a wire-shaped member, a driving portion, a cleaning holder, a cleaning member, a stopper, and a control portion. The control portion is capable of executing a cleaning mode including at least one of a forward travel operation of controlling the wire-shaped member to travel in a first direction so that the cleaning holder moves along the transmissive member and a backward travel operation of, after executing the forward travel operation, controlling the wire-shaped member to travel in a second direction so that the cleaning holder moves in an opposite direction to a direction of the forward travel operation. The control portion executes a load releasing operation of controlling the cleaning holder to move by a prescribed amount in an opposite direction to the direction of the forward travel operation or the direction of the backward travel operation.

An image forming apparatus includes: at least one processor that is configured to generate second image data corresponding to each of a plurality of light emitting elements based on first image data, the second image data indicating whether to cause each of the plurality of light emitting elements to emit light, and based on correction information, change the first image data indicating that the light emitting elements are to emit light, to the second image data indicating that the light emitting elements are not to emit light, and the circuit unit configured to supply a current to each of the plurality of light emitting elements based on the second image data.

An optical scanning device includes a light transmitting member, a guide rail, a holding member, and a cleaning member. The light transmitting member extends in a main scanning direction and transmits a light beam. The guide rail extends in the main scanning direction and is arranged parallel to the light transmitting member. The holding member extends in a cross direction intersecting the main scanning direction and moves in the main scanning direction along the guide rail. The cleaning member is held by the holding member and cleans a light emitting surface of the light transmitting member by means of movement of the holding member in the main scanning direction.

An image forming apparatus includes an exposure unit that exposes a photoconductor; and an exposure support member that includes a support portion that detachably supports the exposure unit and is moved integrally with the exposure unit in a first direction orthogonal to an axial direction of the photoconductor, wherein the exposure unit includes a first engagement portion that is formed on an opposing portion facing the support portion of the exposure support member in the first direction so as to protrude toward the exposure support member and further formed to extend in the axial direction of the photoconductor orthogonal to a protruding direction, the exposure support member includes a second engagement portion that is formed on the support portion facing the exposure unit at a position corresponding to the first engagement portion and engages with the first engagement portion.

In an optical scanning device, an outer wall closest to a circumscribed circle of a rotating polygon mirror has a space in a position facing to a position of a reflection surface of the rotating polygon mirror in an axial direction of a rotating shaft. A part of a cover is provided in a position farther from the circumscribed circle than the outer wall so as to close the space, when the optical scanning device is viewed in a direction perpendicular to the axial direction of the rotating shaft.

A semiconductor light-emitting device includes a semiconductor stacked structure including a light-emitting layer, a metal electrode provided over the semiconductor stacked structure and having an opening for externally emitting a light emitted from the light-emitting layer, and a transparent electrode provided over the semiconductor stacked structure inside the opening and over the metal electrode.

An image forming apparatus includes a photosensitive drum to rotate as to an apparatus main body, a print head having a connector and a light emitting element, a movement mechanism to move the print head between an exposing position and a retracted position, a support part rotatable and to support the movement mechanism, a cable, and an abutting portion. The cable supplies drive signals for driving the light emitting element to the print head. The cable extends toward an opposite side of the connector and is bent toward one direction or another direction of the support part. The abutting portion is provided to the support part, and abuts the cable bent portion in a direction from the retracted position toward the exposing position to cause the cable to flex between a connected portion to the connector and the bent portion, when the print head is at the retracted position.

An image forming apparatus includes a photoconductor drum, a charging device, an exposure device, a development device, and an exposure position changing unit. The charging device is configured to charge the photoconductor drum. The exposure device is configured to irradiate the photoconductor drum and thereby form an electrostatic latent image on the photoconductor drum. The development device is configured to cause toner to adhere to the electrostatic latent image on the photoconductor drum in a two-component-development manner. The exposure position changing unit is configured to change, on the photoconductor drum, an exposure position of the exposure device to a position getting close to the development device from an exposure position for print image development when electric power cutoff is detected.