Abstract: A light source emitting a light flux; a coupling optical system couples the light flux from the light source to a subsequent optical system by transforming it into a parallel light flux, an approximately convergent light flux or an approximately divergent light flux; a light deflector reflects the light flux from the coupling optical system with a deflection reflective surface, and deflects it; a scanning and imaging optical system condenses the deflected light flux from the light deflector onto a surface to be scanned as a beam spot; and a correcting optical system is provided for self correcting shift of focal position of the beam spot on the surface to be scanned occurring due to environmental change or the like.

Abstract: A light source emitting a light flux; a coupling optical system couples the light flux from the light source to a subsequent optical system by transforming it into a parallel light flux, an approximately convergent light flux or an approximately divergent light flux; a light deflector reflects the light flux from the coupling optical system with a deflection reflective surface, and deflects it; a scanning and imaging optical system condenses the deflected light flux from the light deflector onto a surface to be scanned as a beam spot; and a correcting optical system is provided for self correcting shift of focal position of the beam spot on the surface to be scanned occurring due to environmental change or the like.

Abstract: A light source emitting a light flux; a coupling optical system couples the light flux from the light source to a subsequent optical system by transforming it into a parallel light flux, an approximately convergent light flux or an approximately divergent light flux; a light deflector reflects the light flux from the coupling optical system with a deflection reflective surface, and deflects it; a scanning and imaging optical system condenses the deflected light flux from the light deflector onto a surface to be scanned as a beam spot; and a correcting optical system is provided for self correcting shift of focal position of the beam spot on the surface to be scanned occurring due to environmental change or the like.

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<|&Dgr;n(x)−min[&Dgr;n(x)]|<34×10−5, where &Dgr;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[&Dgr;n(x)] denotes the minimum value of the &Dgr;n(x).

Abstract: A multi-beam scanning method for scanning a scanning surface with a plurality of beams which are formed into a plurality of beam spots separated from each other in a sub scanning direction includes providing n number of semiconductor laser array units, each of the n number of semiconductor laser array units having m number of light emitting points, where n is not equal to 1 and m is not equal to 1, coupling light beams emitted from the light emitting points of the semiconductor laser arrays, synthesizing the coupled beams with a beam synthesizing device to obtain m×n number of beams and deflecting the m×n number of beams at substantially the same time such that the deflected beams are impinged on the scanning surface.

Abstract: A scanning and imaging lens condensing a light flux deflected by a deflector onto a surface to be scanned as a beam spot, has a plurality of lenses. A shape in main scanning cross section of each of both surfaces of a lens on a side of deflector has a convex shape, and a shape in main scanning cross section of at least one surface of the lens on the side of deflector is a non-arc shape. A shape in main scanning cross section of a first surface of a lens on a side of surface to be scanned has a convex shape, and a shape in main scanning cross section of at least one surface of the lens on the side of surface to be scanned is a non-arc shape. The scanning and imaging lens has at least two special toroidal surfaces in each of which a curvature in sub-scanning cross section varies in main scanning direction.

Abstract: An optical scanner which performs optical scanning of a surface to be scanned by deflecting a luminous flux having a wavelength &lgr; 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&sgr; in the main scanning direction at a surface accuracy &sgr;i is defined as follows: f&sgr;={2.

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<|&Dgr;n(x)−min[&Dgr;n(x)]|<34×10−5, where &Dgr;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[&Dgr;n(x)] denotes the minimum value of the &Dgr;n(x).

Abstract: An optical scanning device deflects one or a plurality of light flux(es) originating from a light source by an optical deflecting unit, gathers the deflected light flux(es) to cause it(them) to form a beam spot(s) on a surface to be scanned by a scanning and image-forming optical system, and, thus, performs optical scanning of the surface to be scanned. The scanning and image-forming optical system includes one or a plurality of optical component(s) including a lens. At least one surface of the lens included in the scanning and image-forming optical system is a sub-non-arc surface having an arc or non-arc shape in a main scanning plane, and a non-arc shape in a sub-scanning plane. The sub-non-arc surface is formed in a lens in which a diameter of a light flux passing through the scanning and image-forming optical system is largest in the sub-scanning plane’.

Abstract: An optical scanning apparatus is constructed to detect one or more defective or damaged light emitting devices of a light source unit and forms images having substantially the same quality as that of the images formed when all of a plurality of light emitting devices of a light source of the apparatus are functioning normally even when any one of the plurality of light emitting devices are damaged or broken, without decreasing the image forming performance of the apparatus. The optical scanning apparatus detects one or more damaged or broken light emitting devices and then compensates for the light omitted due to the damaged or broken light emitting devices using the normally functioning light emitting devices without decreasing the image forming speed or quality of the optical scanning apparatus.

Abstract: A multi-beam scanning method for scanning a scanning surface with a plurality of beams which are formed into a plurality of beam spots separated from each other in a sub scanning direction includes providing n number of semiconductor laser array units, each of the n number of semiconductor laser array units having m number of light emitting points, where n is not equal to 1 and m is not equal to 1, coupling light beams emitted from the light emitting points of the semiconductor laser arrays, synthesizing the coupled beams with a beam synthesizing device to obtain m×n number of beams and deflecting the m×n number of beams at substantially the same time such that the deflected beams are impinged on the scanning surface.

Abstract: An optical scanning apparatus includes a light source for outputting light, a first lens system arranged to receive the light output from the light source and to transmit a light flux therefrom, an optical deflector arranged to receive the light flux from the first lens system and having a deflecting reflective plane to deflect the light flux from a surface therefrom and a second lens system arranged to receive the light flux deflected from the optical deflector and to condense the deflected luminous flux into an optical beam spot on a surface to be scanned so as to form images having image heights, the luminous flux condensed by the second lens system into the optical beam spot including an optical beam waist.

Abstract: A scanning and image forming lens system in an optical scanning apparatus optical scans a surface to be scanned by deflecting a luminous flux emitted from a light source in a direction corresponding to a main scanning direction via an optical deflector at equiangular velocity. The scanning image forming lens system transmits the luminous flux deflected by the optical deflector so as to condense the luminous flux into an optical beam spot on the surface to be scanned and to scan the surface to be scanned with the optical beam spot. The scanning image forming lens system includes one or more image forming optical elements including at least one lens. At least one lens surface of the at least one lens of the scanning image forming lens system has a non-arc shape in a sub scanning cross section.

Abstract: A scanning and image forming lens system in an optical scanning apparatus optical scans a surface to be scanned by deflecting a luminous flux emitted from a light source in a direction corresponding to a main scanning direction via an optical deflector at equiangular velocity. The scanning image forming lens system transmits the luminous flux deflected by the optical deflector so as to condense the luminous flux into an optical beam spot on the surface to be scanned and to scan the surface to be scanned with the optical beam spot. The scanning image forming lens system includes one or more image forming optical elements including at least one lens. At least one lens surface of the at least one lens of the scanning image forming lens system has a non-arc shape in a sub scanning cross section.

Abstract: An optical scanning apparatus includes a light source for outputting light, a first lens system arranged to receive the light output from the light source and to transmit a light flux therefrom, an optical deflector arranged to receive the light flux from the first lens system and having a deflecting reflective plane to deflect the light flux from a surface therefrom and a second lens system arranged to receive the light flux deflected from the optical deflector and to condense the deflected luminous flux into an optical beam spot on a surface to be scanned so as to form images having image heights, the luminous flux condensed by the second lens system into the optical beam spot including an optical beam waist.

Abstract: A scanning and image forming lens system in an optical scanning apparatus optical scans a surface to be scanned by deflecting a luminous flux emitted from a light source in a direction corresponding to a main scanning direction via an optical deflector at equiangular velocity. The scanning image forming lens system transmits the luminous flux deflected by the optical deflector so as to condense the luminous flux into an optical beam spot on the surface to be scanned and to scan the surface to be scanned with the optical beam spot. The scanning image forming lens system includes one or more image forming optical elements including at least one lens. At least one lens surface of the at least one lens of the scanning image forming lens system has a non-arc shape in a sub scanning cross section.

Abstract: A scanning and image forming lens system in an optical scanning apparatus optical scans a surface to be scanned by deflecting a luminous flux emitted from a light source in a direction corresponding to a main scanning direction via an optical deflector at equiangular velocity. The scanning image forming lens system transmits the luminous flux deflected by the optical deflector so as to condense the luminous flux into an optical beam spot on the surface to be scanned and to scan the surface to be scanned with the optical beam spot. The scanning image forming lens system includes one or more image forming optical elements including at least one lens. At least one lens surface of the at least one lens of the scanning image forming lens system has a non-arc shape in a sub scanning cross section.

Abstract: An optical scanning apparatus includes a light source for outputting light, a first lens system arranged to receive the light output from the light source and to transmit a light flux therefrom, an optical deflector arranged to receive the light flux from the first lens system and having a deflecting reflective plane to deflect the light flux from a surface therefrom and a second lens system arranged to receive the light flux deflected from the optical deflector and to condense the deflected luminous flux into an optical beam spot on a surface to be scanned so as to form images having image heights, the luminous flux condensed by the second lens system into the optical beam spot including an optical beam waist.

Abstract: A multi-beam scanning apparatus comprises a light source unit for emitting a plurality of beams, a beam deflector for deflecting the plurality of beams from the light source unit, and a common scanning image-forming optic for converging the plurality of deflected beams so as to form a plurality of beam spots for simultaneously scanning a scanned surface, a plurality of scan lines respectively described by the plurality of beam spots being isolated from each other in a sub-scanning direction, wherein the plurality of scan lines are bowed in the same direction.

Abstract: An optical scanning apparatus is constructed such that a light beam from a light source is formed into a linear image extending in a main scanning direction and is caused to be deflected at a constant velocity by virtue of a light deflecting system having a deflective reflecting surface which is located in a vicinity of an image formation position of the linear image. The deflected light beam is allowed to transmit through a scanning image formation lens so as to be converged into a beam spot on a surface to be scanned, thus causing the beam spot to scan the surface to be scanned at a constant speed.