Abstract: An optical scanning unit includes a light source that emits a light beam, a light deflector that deflects the light beam from the light source, and a scanning optical system that focuses the light beam deflected by the light deflector on a scanning surface. The light beam from the light source is at an angle in a secondary scanning direction with respect to a normal to a reflecting surface of the light deflector. At least one surface of the scanning optical system does not have a curvature in the secondary scanning direction, being tilted and decentered in the secondary scanning direction.

Abstract: An optical scan device having an optical deflector reflecting a light beam from a light beam source so as to deflect the light beam and having a surface to be scanned on which information is written such that the light beam deflected by the deflector scans the surface is disclosed. Optical detectors are arranged at least in two locations, a start side of writing and an end side of writing, which locations are outside an effective writing area. A measuring part measures a scan time required by the light beam deflected by the optical deflector to scan a range between the optical detectors. A correcting part corrects each dot position of image data in the effective writing area to an arbitrary position based on a variation amount of the measured scan time.

Abstract: An optical scanning unit includes a light source that emits a light beam, a light deflector that deflects the light beam from the light source, and a scanning optical system that focuses the light beam deflected by the light deflector on a scanning surface. The light beam from the light source is at an angle in a secondary scanning direction with respect to a normal to a reflecting surface of the light deflector. At least one surface of the scanning optical system does not have a curvature in the secondary scanning direction, being tilted and decentered in the secondary scanning direction.

Abstract: A scanning optical system condensing a beam deflected by an optical deflector so as to form a beam spot on a surface to be scanned, comprises two lenses. A lens on the side of optical deflector has a negative refracting power in sub-scanning direction. A lens on the side of surface to be scanned has a positive refracting power in the sub-scanning direction. At least one lens surface of the lens surfaces of the two lenses is such that a shape in a sub-scanning section thereof is a non-arc shape.

Abstract: An optical scanning unit includes an optical deflector, a plurality of scanning optical systems, and a pixel-clock generating unit. A photodetector is arranged in at least two locations on a writing-start side and a writing-end side outside the writing area. The optical scanning unit measures a scanning time, and corrects respective dot positions of image data in the writing area to arbitrary positions based on an amount of fluctuation of the scanning time measured.

Abstract: An optical scanner includes a light source modulated based on image data, an optical deflection and scanning part deflecting a light beam emitted from the light source, and a scanning and imaging optical system condensing the deflected light beam toward a scanning surface so as to form a light spot optically scanning the scanning surface. The effective scanning region of the scanning surface is divided into a plurality of regions according to a scanning line curving characteristic. Suitable image data for optically scanning the divided regions are selected from image data of a plurality of image lines every time the light spot optically scans the effective scanning region, so that the image data of each of the image lines is written with scanning line curving being corrected.

Abstract: An optical scanner is capable of effectively correcting a difference with respect to the sub-scanning direction between the positions of optical spots for scanning photoconductor drums of a tandem type color image forming apparatus. The optical scanner includes an optical axis adjusting part. The optical axis adjusting part uses a deflecting mirror or a wedge-shaped prism to deflect the optical axis of an optical beam with respect to the sub-scanning direction. As a result, it is possible to accurately correct a resist difference among individual image forming stations and form a high-quality color image without any color displacement.

Abstract: An optical scanning characteristic control method is applied to an optical scanning system in which a beam is deflected, and the deflected beam is converged and directed toward a scanning surface, so that optical scanning of the scanning surface is performed by an optical spot formed thereon by the deflected beam. The method comprising the steps of a) disposing a beam deflection control device on the light path of the beam before it is incident on the scanning surface; and b) controlling a beam deflection amount of the beam deflecting device provide to an incident beam so as to control a scanning characteristic of the optical scanning.

Abstract: An optical scanner includes a light source modulated based on image data, an optical deflection and scanning part deflecting a light beam emitted from the light source, and a scanning and imaging optical system condensing the deflected light beam toward a scanning surface so as to form a light spot optically scanning the scanning surface. The effective scanning region of the scanning surface is divided into a plurality of regions according to a scanning line curving characteristic. Suitable image data for optically scanning the divided regions are selected from image data of a plurality of image lines every time the light spot optically scans the effective scanning region, so that the image data of each of the image lines is written with scanning line curving being corrected.

Abstract: An optical scanner scans a surface of each of a plurality of latent image carriers by a corresponding light beam. The optical scanner includes a optical deflection unit that deflects and reflects light beams, the optical deflection unit having two or more surfaces that deflect and reflect the light beams in different directions, a lens that takes-in the light beams reflected from the optical deflection unit and divides the light beams into number of light beams equal to number of the image carrier, and an optical system corresponding to each image carrier, the optical system that guides the light beam output from the lens onto a surface of a corresponding one of the image carriers.

Abstract: An optical scanning lens is used in a scanning and image forming optical system which gathers a light flux deflected by a light deflector in the vicinity of a surface to be scanned. The lens is formed by plastic molding of polyolefin resin, and the following condition is satisfied: 0<|?n(x)?min[?n(x)]|<34×10?5, where ?n(x) denotes a refractive-index distribution existing inside the lens, in a range which the light flux passes through, in the lens, and min[?n(x)] denotes the minimum value of the ?n(x).

Abstract: An optical element can effectively correct misalignment of focused positions of optical spots and an optical spot pitch deviation with respect to image heights due to a refractive index distribution therein. The optical element includes a lens, which serves as an optical system in an optical scanner, is shaped in such a profile that misalignment of a focused position of the optical spot due to the refractive index distribution is corrected for image heights.

Abstract: A scanning image formation optical system for use in an optical scanner for scanning a surface for one or more scanning lines. The optical scanner scans the surface by causing one or more coupled luminous fluxes from a light source to be incident on a deflecting reflective surface of a rotating optical deflector, which rotates around a rotary axis of the optical deflector and is parallel to the deflecting reflective surface. The luminous fluxes are deflected diagonally relative to a surface perpendicular to the rotary axis of the optical deflector, and the deflected luminous fluxes are converged toward the surface by the scanning image formation optical system so as to form an optical spot on the scanned surface. The scanning image forming optical system includes two or more special tilt surfaces, each formed such that a tilt amount of a sub-scanning cross-sectional configuration changes in a main scanning direction.

Abstract: An optical scanning characteristic control method is applied to an optical scanning system in which a beam is deflected, and the deflected beam is converged and directed toward a scanning surface, so that optical scanning of the scanning surface is performed by an optical spot formed thereon by the deflected beam. The method comprising the steps of a) disposing a beam deflection control device on the light path of the beam before it is incident on the scanning surface; and b) controlling a beam deflection amount of the beam deflecting device provide to an incident beam so as to control a scanning characteristic of the optical scanning.

Abstract: An optical scanning apparatus is provided, in which the optical scanning apparatus includes: a light source emitting an optical beam; an optical deflection unit deflecting the optical beam emitted from the light source; a scanning optical arrangement scanning a scanned surface by the optical beam in a main scanning direction; and an optical beam detection unit detecting the optical beam moving in the main scanning direction. The optical beam detection unit includes a first photodetector and a second photodetector, and the first photodetector including a first part and a second part that are electrically connected, wherein a first gap is formed between an edge of the first part and a first edge of the second photodetector, a second gap is formed between an edge of the second part and a second edge of the second photodetector, and the first gap and the second gap are not parallel to each other.

Abstract: An optical element can effectively correct misalignment of focused positions of optical spots and an optical spot pitch deviation with respect to image heights due to a refractive index distribution therein. The optical element includes a lens, which serves as an optical system in an optical scanner, is shaped in such a profile that misalignment of a focused position of the optical spot due to the refractive index distribution is corrected for image heights.

Abstract: An optical element can effectively correct misalignment of focused positions of optical spots and an optical spot pitch deviation with respect to image heights due to a refractive index distribution therein. The optical element includes a lens, which serves as an optical system in an optical scanner, is shaped in such a profile that misalignment of a focused position of the optical spot due to the refractive index distribution is corrected for image heights.

Abstract: In an optical scanning device and image forming apparatus according to the present invention, a light source emits a light beam, and a scanning optical unit deflects the light beam from the light source and focuses the deflected light beam to form a light spot on a scanned surface, the scanned surface being scanned by the light beam from the scanning optical unit. A temperature detection unit detects a temperature of the scanning optical unit and its neighboring locations. A temperature compensation unit adjusts a focal-point position of the light beam on the scanned surface in accordance with a change in the temperature detected by the temperature detection unit, the temperature compensation unit adjusting the focal-point position of the light beam by directly varying a focusing effect of a corrector lens on the light beam from the light source by a controlled amount of movement of the corrector lens along its optical axis that corresponds to the temperature change.

Abstract: An optical scanning device condenses a beam deflected by a light deflector, by a scanning and imaging lens toward a surface to be scanned to form a beam spot thereon, and scans the surface to be scanned by the beam spot. At least one lens of the scanning and imaging lens is configured so that a lens body thereof is held by a holding frame, wherein a rib surface at an end in a longitudinal direction of the holding frame is inclined so that a ghost light generated as a result of the deflected beam being reflected by the end in the longitudinal direction of the holding frame is changed in light path in a sub-scan direction.

Abstract: A multi-beam optical scanning apparatus includes a semiconductor laser array slanted relative to a sub-scanning direction and emitting a plurality of optical beams; a coupling lens converting a shape of each optical beam emitted from the semiconductor laser array; and an aperture with an opening having a size of Am×As, arranged after the coupling lens in a direction in which the optical beam progresses, where Am is a dimension of the opening in a main scanning direction and As is a dimension of the opening in the sub-scanning direction. When a length in the main scanning direction of a contour line defined by 1/e2 strength of a maximum strength of an optical beam at the position of the aperture is Lm, and a length in the sub-scanning direction of the contour line defined by 1/e2 strength of the maximum strength of the optical beam at the position of the aperture is Ls, the following conditional expressions are satisfied: Am<Lm, and??(1) Ls/Lm×0.3<As/Am<Ls/Lm×1.7.