Abstract: A multi-beam optical scanning device is disclosed that includes a light source emitting a bundle of rays, a first optical system coupling the rays into diverging rays, a second optical system condensing the diverging rays into linear rays extending in the main scanning direction, a light deflector deflecting the linear rays, and a third optical system condensing the deflected rays onto a scanning surface. The second and third optical systems include resin imaging elements. At least one resin imaging element of the second optical system has a negative power in a sub scanning direction and a surface configuration that is arranged to effectively compensate for a change in field curvature caused by a temperature change in a support member of the first optical system or the resin imaging element of the third optical system. The second optical system as a whole has a positive power in the main scanning direction.

Abstract: An optical scanner includes a light source, an optical coupler, an optical line image unit, a deflector, and an optical scanning unit. The optical scanning unit includes scanning lenses that guide the beams to a surface to be scanned. A surface on the deflector side of the scanning lens closest to a deflection reflecting surface has a negative power in a vertical scanning direction, and is a special toric surface in which a radius of curvature in a vertical scanning changes from an optical axis of the lens surface toward a periphery of the horizontal scanning direction. An F number of the beams toward the surface to be scanned of the scanning lens in the vertical scanning direction is larger in a peripheral part than in a central part in an effective scanning width.

Abstract: A scanning optical system deflects a light flux emitted by a light source by an optical deflector, and focuses the light flux on a surface to be scanned through a scanning lens. The scanning optical system includes a kink producing unit that produces a kink in the scanning lens.

Abstract: An optical scanning apparatus includes a light source that emits a light beam, optical systems through which the light beam travels including one that forms a line image, a polygon mirror that rotates and deflects the light beam with a deflective reflection surface, and a scanning optical system that converges the light beam to scan a target surface with a light beam spot. The optical system closer to the light source than the polygon mirror is configured so as to correct a change in an image-forming position of the light beam spot caused by deformation of the deflective reflection surface originating from the rotation of the polygon mirror.

Abstract: An optical scanning apparatus includes a light source that emits a light beam, optical systems through which the light beam travels including one that forms a line image, a polygon mirror that rotates and deflects the light beam with a deflective reflection surface, and a scanning optical system that converges the light beam to scan a target surface with a light beam spot. The optical system closer to the light source than the polygon mirror is configured so as to correct a change in an image-forming position of the light beam spot caused by deformation of the deflective reflection surface originating from the rotation of the polygon mirror.

Abstract: An optical scanner includes a light source, an optical coupler, an optical line image unit, a deflector, and an optical scanning unit. The optical scanning unit includes scanning lenses that guide the beams to a surface to be scanned. A surface on the deflector side of the scanning lens closest to a deflection reflecting surface has a negative power in a vertical scanning direction, and is a special toric surface in which a radius of curvature in a vertical scanning changes from an optical axis of the lens surface toward a periphery of the horizontal scanning direction. An F number of the beams toward the surface to be scanned of the scanning lens in the vertical scanning direction is larger in a peripheral part than in a central part in an effective scanning width.

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 scanning device, including a resin lens having a power that is an inverse power of scanning lens placed before a deflector. A bundle of rays emitted from a plurality of light sources is coupled into a desired state by coupling lens, after which the bundle of rays is incident on the resin lens. The surface of incidence of the resin lens has a spherical surface with a negative power, and the exit surface of this resin lens has a cylindircal surface with a negative power only in the sub scanning direction. The bundle of rays passes through the resin lens and enters a glass toroidal lens. A light deflector deflects the bundle of rays from the toroidal lens. The deflected bundle of rays is incident on a third optical system that condenses the deflected bundle of rays onto a surface to be scanned.

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: 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.

Abstract: An optical scanner which performs optical scanning of a surface to be scanned by deflecting a luminous flux having a wavelength ? from a light source by means of an optical deflector, and condensing the deflected flux toward the surface to be scanned through a scanning image forming optical system, thereby forming an optical spot on the surface to be scanned. The scanning image forming optical system has at least one lens, and when the focal length f? in the main scanning direction at a surface accuracy ?i is defined as follows: f?={2.

Abstract: A scanning and imaging optical system that condenses beams of light deflected by an optical deflector toward a surface to be scanned to form a light spot for optical scanning on the surface includes plurality of scanning lenses. Among the scanning lenses, at least two of the scanning lenses are resin lenses that are formed by plastic molding, and where a position coordinate in a horizontal scanning direction or in a vertical scanning direction is X, refractive index distribution in a cross-section with respect to the position coordinate X is ?n(X), the refractive index distribution in a cross-section in the horizontal scanning direction that includes an optical axis or in the vertical scanning direction of the resin lenses, signs of the refractive index distribution ?n(X) at least in the vertical scanning direction are not identical for all of the resin lenses.

Abstract: Scanning optics of the present invention effectively reduces the variation of the curvature of field in the main and subscanning directions ascribable to varying environment, which includes temperature and humidity. This, coupled with the fact that the scanning optics desirably corrects wavefront aberration, reduces the variation of a beam spot diameter and implements a desirable beam spot with a small diameter. A scanning device with such optics can effect desirable optical scanning with a stable, small-diameter beam spot and allows an image forming apparatus to form attractive images.

Abstract: In an optical scanning device, a resin lens having a power that is an inverse (negative) power of a scanning lens is implemented in an optical system placed before a deflector so that a change in beam pitch caused by environmental temperature change can be prevented even when a resin lens is used as the scanning lens. To realize optical scanning using this device, a bundle of rays emitted from a plurality of light sources is coupled into a desired state by a coupling lens, after which the bundle of rays is incident on a resin lens. The surface of incidence of this resin lens has a spherical surface configuration with a negative power, and the exit surface of this resin lens has a cylindrical surface configuration with a negative power only in the sub scanning direction. Then, the bundle of rays passes through a resin lens that has a negative power only in the sub scanning direction and then enters a glass toroidal lens.

Abstract: An optical system includes three optical systems. The first has a coupling lens. The second includes a lens having a positive power in a vertical scanning direction and forms the light flux into a line image extending in the horizontal scanning direction on a deflector. The third includes a first lens having a positive power in the horizontal scanning direction, and a second lens having a positive power in the vertical scanning direction. Lateral magnification in the horizontal scanning direction is set larger than that in the vertical scanning direction. Temperature near the first lens is maintained higher than that near the second lens.

Abstract: An optical scanner has a deflector, a coupling lens, a cylindrical lens, a plate through which light to and from the deflector pass, and an optical system which condenses the light deflected on a surface to be scanned. Bundles of light beams incident on the deflector have an angle between the bundles in a rotating plane of the deflector, and expressions 0.6<(?1max??)/(?2+?)<1.4, and 0.6<(?1min??)/(?2+?)<1.4, are satisfied, where ?1max and ?1min are maximum and minimum average angles of incidence on the deflecting surface, ?2 is a half-view angle, and ? is an angle of inclination of the plate in the rotating plane with respect to a main scanning direction.

Abstract: An optical scanner includes a light source, an optical coupler, an optical line image unit, a deflector, and an optical scanning unit. The optical scanning unit includes scanning lenses that guide the beams to a surface to be scanned. A surface on the deflector side of the scanning lens closest to a deflection reflecting surface has a negative power in a vertical scanning direction, and is a special toric surface in which a radius of curvature in a vertical scanning changes from an optical axis of the lens surface toward a periphery of the horizontal scanning direction. An F number of the beams toward the surface to be scanned of the scanning lens in the vertical scanning direction is larger in a peripheral part than in a central part in an effective scanning width.

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.