A holding member 505 includes a first side wall portion 505a and a second side wall portion 505b, and a part of a surface 803b of a substrate 502 on a side opposite from a mounting surface 803 and a holding member 505 are fixed to each other by an adhesive. In the first side wall portion 505a, an inserting hole 801 opposing a corner portion 502 as of the substrate 502 in a widthwise direction of the substrate 502, and also, in the second side wall portion 505b, an inserting hole 801 opposing a corner portion 502bs of the substrate 502.

An exposure device includes an optical system member that forms an image of light from a light emitting element array having multiple light emitting elements arranged, an optical system support part that supports the optical system member, and a restraining member that restrains the optical system member to the optical system support part. The optical system support part has sliding parts, which are able to slide relative to the restraining member, formed on a light emitting element side face and an image forming side face in positions opposing the both end parts or the vicinity of both end parts in a longitudinal direction of the optical system support part, and in the both end parts or in the vicinity of the both end parts in the longitudinal direction, the restraining member is formed between the sliding parts and the optical system member, fixed to the optical system member, and slidable in the longitudinal direction relative to the optical system support part.

An optical writing control device controls emission or lighting of a light source onto a photoconductor surface in a latent image forming process and a discharge process, by either setting a light emission time longer in the discharge process or setting a resolution in a sub-scanning direction lower in the discharge process, compared to the latent image forming process.

A light-emitting apparatus includes: first and second array-shaped light emitters arranged in substantially parallel with each other to have a overlapping portion where a part of an area where the first array-shaped light emitter is capable of forming an image and a part of an area where the second array-shaped light emitter is capable of forming an image are overlapped with each other; a division unit that divides, based on a pixel pattern of bit map data including multiple pixel data, the bit map data into a first partial bit map data and a second partial bit map data; and a controller that allocates the first and second partial bit map data to the first and second array-shaped light emitters, respectively, and controls the first and second array-shaped light emitters based on the first and second partial bit map data.

An exposure device capable of precisely focusing light on a scanned surface to accomplish a good image quality is provided. The exposure device includes a substrate on which a plurality of light sources are arranged along a main-scanning direction, a lens array including a plurality of lenses configured to focus light emitted by the plurality of light sources on a scanned surface, and a housing configured to support the substrate and the lens array such that a certain spacing is maintained between the plurality of light sources and the plurality of lenses. At least a portion of the substrate is spaced apart from the housing along a sub-scanning direction.

A light emitting device includes a first light-emitting-element row that includes light emitting elements arranged in a row in a main scanning direction and a second light-emitting-element row that includes light emitting elements arranged in a row in the main scanning direction and that is positioned in such a manner that at least a portion of the second light-emitting-element row overlaps the first light-emitting-element row in a sub scanning direction. The first and second light-emitting-element rows are each formed by arranging light-emitting-element array chips in each of which the light emitting elements are arranged in a row in the main scanning direction. In each of the light-emitting-element array chips, a pitch of the light emitting elements arranged in a row is changed from a first pitch to a second pitch, which is different from the first pitch, in a central region of the row of the light emitting elements.

A light emitting device includes: a first light-emitting-element row that includes light emitting elements arranged in a row in a main scanning direction; a second light-emitting-element row that includes light emitting elements arranged in a row in the main scanning direction and that is positioned in such a manner that at least a portion of the second light-emitting-element row overlaps the first light-emitting-element row in a subscanning direction; and a light-emission control unit that switches a light-emitting-element row caused to emit light between the first light-emitting-element row and the second light-emitting-element row at a switching point that is set at a position in an overlapping portion in which the first light-emitting-element row and the second light-emitting-element row overlap each other. The light-emission control unit sequentially turns on the light emitting elements in the overlapping portion in the order in which the light emitting elements are arranged and sets a direction in which the light emitting elements are sequentially turned on in the first light-emitting-element row and a direction in which the light emitting elements are sequentially turned on in the second light-emitting-element row to be the same as each other.

A light emitting element device includes: a light emitting thyristor having a layered structure including a first semiconductor layer of a first conductivity type, a second semiconductor layer of a second conductivity type different from the first conductivity type, a third semiconductor layer of the first conductivity type, and a fourth semiconductor layer of the second conductivity type that are layered in this order; and a gate electrode for supplying gate current to the light emitting thyristor. The light emitting thyristor includes an etching stop layer disposed on a surface of the third semiconductor layer or included in the third semiconductor layer, the etching stop layer being a semiconductor layer having an etching rate lower than an etching rate of a semiconductor layer adjacent to the etching stop layer.

A light emitting apparatus includes: plural first light emitting units arranged at intervals along a predetermined first direction; plural second emitting units arranged at intervals along the first direction, maned at positions deviating tram the first light emitting units in a second direction intersecting the first direction, and arranged at positions deviating from the first light emitting units in the first direction, first wirings electrically connected to each of the first light emitting units by a semiconductor layer; and second wirings electrically connected to each of the second light emitting units, and disposed with an insulating layer interposed between the second light emitting units and the second wirings in a third direction that intersects the first direction and the second direction.

A method for manufacturing a laminated substrate includes removing a portion not covered with a resist layer from a laminated substrate with an etchant to form a wiring, the laminated substrate including: a base layer including a mesa portion having a trapezoidal cross section, the mesa portion having a first inclined surface extending downward and outward from a top surface and a second inclined surface having an eaves-shaped portion protruding outward from the top surface; a wiring layer formed on an upper surface of the base layer; and the resist layer formed on an upper surface of the wiring layer and having a shape corresponding to a shape of the wiring, and the wiring is arranged at a position where the wiring covers a whole of the eaves-shaped portion of the second inclined surface.