Focusing optics can include optical elements disposed and bonded in a linear arrangement (linear array) in at least two rows. A transparent bonding agent can secure alignment of the at least two rows of the optical elements. Scattering elements can also be disposed in the transparent polymer to cause light diffusion. Diffused or un-diffused light from a semiconductor laser array can then be caused to pass through the optical element and illuminate a target substrate such as an imaging member in a printing system.

There is provided an exposure head including: a holder; a substrate on which a plurality of light-emitting elements is mounted along a rotational axis direction of the image bearing member, a lens array including a plurality of lenses configured to transmit light emitted from the plurality of light-emitting elements and condense the light on the image bearing member; and an adhesive fixing the substrate and the lens array to the holder in a state in which the plurality of light-emitting elements and the lenses face each other and in a state in which the substrate and the holder are separated from each other. The substrate includes a first facing portion facing the holder with a first gap therebetween in a lateral direction of the substrate, and a second facing portion facing the holder with a second gap therebetween which is larger than the first gap in the lateral direction, and the adhesive fixes the substrate and the holder via the second facing portion.

Provided is an exposure device having an extended shape in an axial direction to expose a photoreceptor, the exposure device including a substrate including a plurality of light emitting elements that emit light for exposing the photoreceptor arranged along the axial direction; a lens array for condensing light emitted from a light emitting element on the photoreceptor; a holder for holding the substrate and the lens array; a first contact electrically connected to the light emitting element for input of a signal for controlling emission of light; and a second contact positioned away from the first contact in a longitudinal direction of the substrate, the second contacted electrically connected to the light emitting element and for input of a signal for controlling emission of light emitting element.

An exposure head includes a substrate assembly including a first light emitting chip, a second light emitting chip, and a substrate on which the first light emitting chip and the second light emitting chip are mounted, a lens array, a retaining member, and a first adhesion portion. In a state where an area on the substrate where the end portion of the second light emitting chip and the end portion of the first light emitting chip overlap when viewed in the sub-scanning direction is referred to as a first area, and where an area of the lens array superposed with the first area when viewed in an optical axis direction of the lens array is referred to as a second area, the first adhesion portion is configured to adhere both end portions of the lens array in the sub-scanning direction to the retaining member in the second area.

A light emitting device includes a plurality of light emitting elements arranged on a main surface of a substrate in M columns and N rows (M and N are integers of one or more), and a plurality of pixel drive circuits arranged in M columns and N rows and configured to drive a corresponding light emitting element among the plurality of light emitting elements. The N rows and M columns extend in a first and second directions, respectively. A first array pitch of a first light emitting element and a second light emitting element adjacent to each other in the first direction parallel to the N rows among the plurality of light emitting elements is different from a second array pitch of a first pixel drive circuit and a second pixel drive circuit adjacent to each other in the first direction among the plurality of pixel drive circuits.

An exposure head includes a substrate on which light sources are mounted, and a condensing optical system. A memory stores a profile indicating correction gains for exposure amounts. A sensor detects a temperature. A processor acquires a correction gain that corresponds to a position of a light source that reached an exposure timing, corrects, for each of the light sources, an exposure amount of the light source with the correction gain corresponding to the position of the light source, and adjusts, for each of the light sources, a reference position of the corresponding correction gain in the profile in accordance with the temperature detected by the sensor.

A print head includes a light-emitting element panel, a lens array, and a fixing member. A rib is provided on a surface (rear surface) of the fixing member constituted by a resin material. A plurality of light-emitting elements are provided on the light-emitting element panel such that none of light-emitting points overlaps rib regions, or at least two ribs are provided so as to intersect each other on the surface (rear surface) of the fixing member. The plurality of light-emitting elements are provided on the light-emitting element panel such that none of the light-emitting points overlaps an intersection region.

In order to provide a polygon mirror which can reduce a light amount difference among respective image heights on a scanned surface with suppressing an increase in size in a light scanning apparatus, the polygon mirror according to the present invention includes a plurality of rectangular reflecting surfaces in which the following condition is satisfied:
0.02<|1B/A|<0.10 where A represents a reflectivity at a center of the reflecting surface with respect to a light flux which is incident at a predetermined incident angle, and B represents the reflectivity at a predetermined point between the center and an end in the longitudinal direction of the reflecting surface with respect to the light flux which is incident at the predetermined incident angle.

An imaging device includes: M rotatable photosensitive drums, at least one display chip, at least one projection lens, and at least one beam deflection system. The light-receiving region of each photosensitive drum includes multiple light-receiving sub-regions. Each display chip includes at least two light-emitting regions arranged in a first direction. At least one projection lens is in one-to-one correspondence with the at least one display chip. Each projection lens is configured to form an image for a corresponding display chip. The at least one beam deflection system is in one-to-one correspondence with the at least one display chip. The beam deflection system is configured to deflect an image, which is formed by light from each light-emitting region in the display chip through a corresponding projection lens, to a corresponding light-receiving sub-region.

An image forming apparatus includes: a panel member opposing a photoreceptor drum and having plural light-emitting elements; a lens focusing light emitted from the light-emitting elements onto the photoreceptor drum; and a holding member holding the lens. The holding member and the lens adhere to each other in a first adhesive region located at a center in a longitudinal direction (width direction) and a second adhesive region located at an end in the longitudinal direction. A shrinkage rate differs between the first adhesive region and the second adhesive region.