Abstract: An optical device includes a rectangular parallelepiped prism including a reflection-transmission surface for reflecting and transmitting light fluxes, a seating surface provided so that a bottom surface of the prism is fixed by an adhesive, and a groove portion provided in a part of the periphery of the seating surface. When the prism is fixed to the seating surface by the adhesive, the groove portion is configured to be capable of receiving the adhesive protruded from between the bottom surface of the prism and the seating surface when the prism is pressed against a first positioning member for determining a position of the prism so that a first side face of the prism is along a predetermined straight line and against a second positioning member for restricting a second side face orthogonal to the first side face of the prism from moving in the direction of the straight line.

Abstract: An image display apparatus includes: a laser light source configured to emit laser light in accordance with an image; an optical deflector configured to deflect the laser light emitted by the laser light source; a to-be-scanned member configured to make an image diverge at a predetermined angle of divergence, the image being drawn with the laser light deflected by the optical deflector; and a housing forming a curved housing space for housing the to-be-scanned member. The housing houses the to-be-scanned member in the housing space to let the to-be-scanned member curve with a predetermined curvature.

Abstract: An optical scanner includes a light source including a plurality of light emitting elements, a polygon mirror which deflects light from the light source for scanning a surface of a subject, an optical element arranged between the light source and the polygon mirror, having optical power in a sub scanning direction, a synchronous detector which detects the light deflected by the polygon mirror for synchronous detection and generates a signal for controlling a timing at which the scanning of the surface is started, and a fixing element which secures one end of the optical element. The light emitting elements of the light source are aligned with a certain tilt angle relative to the sub scanning direction. Light from one of the light emitting elements disposed closest to the fixing element in a main scanning direction is used for synchronous detection.

Abstract: An optical device includes a rectangular parallelepiped prism including a reflection-transmission surface for reflecting and transmitting light fluxes, a seating surface provided so that a bottom surface of the prism is fixed by an adhesive, and a groove portion provided in a part of the periphery of the seating surface. When the prism is fixed to the seating surface by the adhesive, the groove portion is configured to be capable of receiving the adhesive protruded from between the bottom surface of the prism and the seating surface when the prism is pressed against a first positioning member for determining a position of the prism so that a first side face of the prism is along a predetermined straight line and against a second positioning member for restricting a second side face orthogonal to the first side face of the prism from moving in the direction of the straight line.

Abstract: An optical scanner includes a light source including a plurality of light emitting elements, a polygon mirror which deflects light from the light source for scanning a surface of a subject, an optical element arranged between the light source and the polygon mirror, having optical power in a sub scanning direction, a synchronous detector which detects the light deflected by the polygon mirror for synchronous detection and generates a signal for controlling a timing at which the scanning of the surface is started, and a fixing element which secures one end of the optical element. The light emitting elements of the light source are aligned with a certain tilt angle relative to the sub scanning direction. Light from one of the light emitting elements disposed closest to the fixing element in a main scanning direction is used for synchronous detection.

Abstract: An optical scanner includes a light source including a plurality of light emitting elements, a polygon mirror which deflects light from the light source for scanning a surface of a subject, an optical element arranged between the light source and the polygon mirror, having optical power in a sub scanning direction, a synchronous detector which detects the light deflected by the polygon mirror for synchronous detection and generates a signal for controlling a timing at which the scanning of the surface is started, and a fixing element which secures one end of the optical element. The light emitting elements of the light source are aligned with a certain tilt angle relative to the sub scanning direction. Light from one of the light emitting elements disposed closest to the fixing element in a main scanning direction is used for synchronous detection.

Abstract: In a light beam scanning device, a plurality of light sources, which irradiates a plurality of light beams in a first direction and is retained by a holder, are disposed at distance from one another in a second direction orthogonal to the first direction. The plurality of light beams are incident, via a coupling optical system, to deflecting and reflecting surfaces of a deflector from a direction that is tilted with respect to a plane orthogonal to the rotational shaft of the deflector. The holder is supported by a housing of the light beam scanning device at a plurality of different positions in a third direction extending from the light source to the coupling optical system.

Abstract: A straight tube LED lamp includes a substrate on which semiconductor light-emitting elements are mounted in longitudinal direction, a long metal chassis with a semi-circular cross section, to mount the substrate in a chord portion of the semi-circle, a resin sheet interposed between the chassis and the substrate, a translucent element contacting the chassis to form a circle, made from a resin or glass through which light beams from semiconductor light-emitting elements are transmitted, cap elements to cover both ends of the chassis and the translucent element and connectable to a lamp fitting, and a power supply board on which an electronic component for AC-DC conversion to supply current to the semiconductor light-emitting elements is mounted, contained in the chassis. The resin sheet is made from different materials at least at an overlapping portion and a non-overlapping portion of the power supply board and the substrate in longitudinal direction.

Abstract: An optical scanner includes a light source including a plurality of light emitting elements, a polygon mirror which deflects light from the light source for scanning a surface of a subject, an optical element arranged between the light source and the polygon mirror, having optical power in a sub scanning direction, a synchronous detector which detects the light deflected by the polygon mirror for synchronous detection and generates a signal for controlling a timing at which the scanning of the surface is started, and a fixing element which secures one end of the optical element. The light emitting elements of the light source are aligned with a certain tilt angle relative to the sub scanning direction. Light from one of the light emitting elements disposed closest to the fixing element in a main scanning direction is used for synchronous detection.

Abstract: An optical writer includes a housing, a light source, a deflector, and a plurality of optical elements. The housing includes a plurality of surfaces, one of which includes a substantially flat portion having an opening formed therein and a curved portion curved in the shape of an arc of a circle in cross-section. The light source is enclosed within the housing and projects light through the opening and onto a target. The deflector is enclosed within the housing and deflects the light projected from the light source in a main scanning direction. The plurality of optical elements is enclosed within the housing and directs the light deflected by the deflector onto the target.

Abstract: An optical writing unit includes in a housing a light source projecting a light beam, a deflector to deflect the light beam projected from the light source, a focusing lens, and a lens adjusting device. The focusing lens is long in a main scanning direction and focuses the light beam onto a scan target. The lens adjusting device rotates the focusing lens about a substantially center portion thereof as a rotation fulcrum on a plane perpendicular to an optical path of the light beam so as to adjust the position of the light beam illuminating the scan target. The focusing lens has an asymmetric cross-section relative to a center line of the focusing lens in a direction of the optical path in a sub-scanning plane perpendicular to the main scanning direction, and the center of gravity of the focusing lens is offset from the center line toward the rotation fulcrum.

Abstract: A straight tube LED lamp includes a substrate on which semiconductor light-emitting elements are mounted in longitudinal direction, a long metal chassis with a semi-circular cross section, to mount the substrate in a chord portion of the semi-circle, a resin sheet interposed between the chassis and the substrate, a translucent element contacting the chassis to form a circle, made from a resin or glass through which light beams from semiconductor light-emitting elements are transmitted, cap elements to cover both ends of the chassis and the translucent element and connectable to a lamp fitting, and a power supply board on which an electronic component for AC-DC conversion to supply current to the semiconductor light-emitting elements is mounted, contained in the chassis. The resin sheet is made from different materials at least at an overlapping portion and a non-overlapping portion of the power supply board and the substrate in longitudinal direction.

Abstract: The image forming apparatus includes a chassis; plural image bearing members; plural optical scanning devices having the same configuration and located on respective installation positions of the chassis after installed thereon to scan the image bearing members with light beams; and plural incompatibility imparting mechanisms. The incompatibility imparting mechanisms are located on the corresponding optical scanning devices, and have the same configuration and the same initial state before the plural optical scanning devices are installed on the chassis, but achieve incompatible states after the optical scanning devices are installed. When the optical scanning devices in the incompatible states are detached from the chassis and then attached again thereto, the incompatibility imparting mechanisms prevent the corresponding optical scanning devices from being set to positions other than the respective installation positions.

Abstract: An optical writing unit includes in a housing a light source projecting a light beam, a deflector to deflect the light beam projected from the light source, a focusing lens, and a lens adjusting device. The focusing lens is long in a main scanning direction and focuses the light beam onto a scan target. The lens adjusting device rotates the focusing lens about a substantially center portion thereof as a rotation fulcrum on a plane perpendicular to an optical path of the light beam so as to adjust the position of the light beam illuminating the scan target. The focusing lens has an asymmetric cross-section relative to a center line of the focusing lens in a direction of the optical path in a sub-scanning plane perpendicular to the main scanning direction, and the center of gravity of the focusing lens is offset from the center line toward the rotation fulcrum.

Abstract: In a light beam scanning device, a plurality of light sources, which irradiates a plurality of light beams in a first direction and is retained by a holder, are disposed at distance from one another in a second direction orthogonal to the first direction. The plurality of light beams are incident, via a coupling optical system, to deflecting and reflecting surfaces of a deflector from a direction that is tilted with respect to a plane orthogonal to the rotational shaft of the deflector. The holder is supported by a housing of the light beam scanning device at a plurality of different positions in a third direction extending from the light source to the coupling optical system.

Abstract: An optical writer includes a housing, a light source, a deflector, and a plurality of optical elements. The housing includes a plurality of surfaces, one of which includes a substantially flat portion having an opening formed therein and a curved portion curved in the shape of an arc of a circle in cross-section. The light source is enclosed within the housing and projects light through the opening and onto a target. The deflector is enclosed within the housing and deflects the light projected from the light source in a main scanning direction. The plurality of optical elements is enclosed within the housing and directs the light deflected by the deflector onto the target.

Abstract: The image forming apparatus includes a chassis; plural image bearing members; plural optical scanning devices having the same configuration and located on respective installation positions of the chassis after installed thereon to scan the image bearing members with light beams; and plural incompatibility imparting mechanisms. The incompatibility imparting mechanisms are located on the corresponding optical scanning devices, and have the same configuration and the same initial state before the plural optical scanning devices are installed on the chassis, but achieve incompatible states after the optical scanning devices are installed. When the optical scanning devices in the incompatible states are detached from the chassis and then attached again thereto, the incompatibility imparting mechanisms prevent the corresponding optical scanning devices from being set to positions other than the respective installation positions.

Abstract: An image forming apparatus includes a plurality of image carriers and an optical writing device including light sources that emit light beams of different wavelengths, a deflector that deflects the light beams emitted from the light sources and synthesized on an identical axis in a sub-scanning direction, a first beam separator, a second beam separator, a first imaging device, and a second imaging device. The first beam separator and the second beam separator are located between the first imaging device and the second imaging device and transmit or reflect the light beams according to travel directions or wavelengths thereof. One of the targets is scanned with the light beam transmitted through the second beam separator. Another target is scanned with the light beam reflected by the second and first beam separators. The first and second imaging devices narrow the beams in the main scanning direction and the sub-scanning direction, respectively.

Abstract: An image forming apparatus is provided with a light scanning device that directs laser beams emitted from a plurality of laser light sources on to a plurality of photoconductive members via focusing device which includes optical elements and a deflecting device that deflects the beams in a main scanning direction; an image forming device which forms visible images of different colors from images written onto the photoconductive members by the light scanning device; and an intermediate transfer member or a recording sheet transport member capable of carrying the visible images formed on the photoconductive members. When in detection mode, a control device controls the correction of color registration errors between each color forms patterns on an intermediate belt by an image forming device, detects the patterns by a color registration error detection sensor, and stores the color registration error correction values obtained from the detection output of the sensor in a memory device.

Abstract: An optical writing device that writes electrostatic latent images on an image carrier by irradiating and scanning the image carrier with an optical beam includes an optical element, a support housing configured to support members constituting the optical writing device, a pair of optical-element holding members opposing each other in a principal scanning direction and arranged in the support housing, and a displacing member configured to displace at least one of the pair of optical-element holding members relatively to the support housing on a plane perpendicular to the principal scanning direction. The optical-element holding member is made of a material having a coefficient of linear expansion smaller than that of the support housing.