Abstract: A scanning optical apparatus includes incident optical system for causing at least one light beam emitted from a light source to be incident on a deflection device and image formation optical system including at least one refractive optical element and at least one diffraction optical element for imaging said at least one light beam reflected and deflected by the deflection device on a surface to be scanned. The diffraction optical element has at least one of an incident surface having a convex shape in a sub-scanning cross-section facing the deflection device and an exit surface having a convex shape in the sub-scanning cross-section facing the surface to be scanned.

Abstract: To obtain an optical element capable of obtaining uniform antireflection characteristics over the whole optical surface having a finite curvature of the optical element, a plurality of convex optical pieces having an antireflection function are provided on a surface having the finite curvature of the optical element independently along a normal direction of the surface having the finite curvature of the optical element.

Abstract: The present invention provides an optical scanning apparatus capable of satisfactorily correcting a field curvature caused by spherical aberration in an incidence optical system, and an image forming apparatus using the same. A light beam emitted from light source means is guided to an optical deflector for deflecting the light beam through a first optical system having a collimating operation, and a second optical system including a surface having a beam expanding operation and an aspherical operation for compensating for aberration in order. When the light beam deflected by the optical deflector is guided to a surface to be scanned through a third optical system, the light beam emitted from the light source means is converted into a nearly collimated light beam through the first and second optical systems within a main scanning cross section and is made incident on a deflecting surface of the optical deflector to make its width wider than that of the deflecting surface thereof in a main scanning direction.

Abstract: The optical element has a microstructure lattice formed on at least one optical surface. In the optical element, the microstructure lattice is formed from an arrangement for adjusting a change in an amount of light transmitted which is caused as an incidence angle of a light beam changes from a central portion to a peripheral portion.

Abstract: Provided is a scanning optical system in which the influence of structural birefringence resulting from a relationship between the arrangement direction of a fine grating structure and polarization planes is reduced to obtain a preferable optical performance, and an image forming apparatus using the scanning optical system. In the scanning optical system, a light flux emitted from a light source unit is deflected by a deflection unit. The light flux deflected by the deflection unit is guided onto a surface to be scanned by a scanning optical unit having a fine structural grating on at least one optical surface. The surface to be scanned is scanned with the light flux. The fine structural grating has a triangular grating in which triangular grating parts are arranged in one dimensional direction.

Abstract: To obtain an optical element that can reduce Fresnel (surface) reflection on a lens surface to be a cause of flare or ghost, and a scanning optical system having the same.

Abstract: By setting the direction of arrangement of a fine structure grating, it is possible to reduce influence of the structural birefringence of a fine structure grating provided on an optical surface in a scanning optical system to provide a scanning optical system having good optical properties that is not depend on the polarization state of an incident light flux and to provide an image forming apparatus using the same. In the scanning optical system, a light flux emitted from a laser light source 1 is deflected by deflecting device and the light flux having been deflected by the deflecting device is imaged by scanning optical unit 6 onto a surface 7 to be scanned so as to scan the surface to be scanned. The scanning optical unit has at least one optical surface that has a fine structure grating 8 having a grating pitch smaller than the wavelength of the light flux emitted from said laser light source.

Abstract: An object of the present invention is to provide a scanning optical system capable of reducing the number of its components and its size with a simple construction, and an image forming apparatus using the scanning optical system. In a specific scanning optical system, a plurality of light beams emitted from a plurality of light source units are deflected and scanned by a plurality of different deflecting facets of a common optical deflecting unit, and a plurality of scanned surfaces are scanned with the light beams deflected and scanned by the different deflecting facets, respectively.

Abstract: A scanning optical apparatus includes incident optical system for causing at least one light beam emitted from a light source to be incident on a deflection device and image formation optical system including at least one refractive optical element and at least one diffraction optical element for imaging said at least one light beam reflected and deflected by the deflection device on a surface to be scanned. The diffraction optical element has at least one of an incident surface having a convex shape in a sub-scanning cross-section facing the deflection device and an exit surface having a convex shape in the sub-scanning cross-section facing the surface to be scanned.

Abstract: Provided is a scanning optical system in which the influence of structural birefringence resulting from a relationship between the arrangement direction of a fine grating structure and polarization planes is reduced to obtain a preferable optical performance, and an image forming apparatus using the scanning optical system. In the scanning optical system, a light flux emitted from a light source unit is deflected by a deflection unit. The light flux deflected by the deflection unit is guided onto a surface to be scanned by a scanning optical unit having a fine structural grating on at least one optical surface. The surface to be scanned is scanned with the light flux. The fine structural grating has a triangular grating in which triangular grating parts are arranged in one dimensional direction.

Abstract: A scanning optical apparatus includes incident optical system for causing at least one light beam emitted from a light source to be incident on a deflection device and image formation optical system including at least one refractive optical element and at least one diffraction optical element for imaging said at least one light beam reflected and deflected by the deflection device on a surface to be scanned. The diffraction optical element has at least one of an incident surface having a convex shape in a sub-scanning cross-section facing the deflection device and an exit surface having a convex shape in the sub-scanning cross-section facing the surface to be scanned.

Abstract: A scanning optical apparatus which includes incident optical system for causing at least one light beam emitted by light source onto a deflector, and image forming optical system, having at least one diffraction surface, for imaging the at least one light beam reflected and deflected by the deflector on a surface to be scanned. The apparatus further includes limiting member, inserted in the optical path between the diffraction surface of the image forming optical system and the surface to be scanned, for limiting unnecessary diffraction light of another order with respect to diffraction light of an order used to form a spot on the surface to be scanned from among the diffraction light diffracted by the diffraction surface.

Abstract: By setting the direction of arrangement of a fine structure grating, it is possible to reduce influence of the structural birefringence of a fine structure grating provided on an optical surface in a scanning optical system to provide a scanning optical system having good optical properties that is not depend on the polarization state of an incident light flux and to provide an image forming apparatus using the same. In the scanning optical system, a light flux emitted from a laser light source 1 is deflected by deflecting means and the light flux having been deflected by the deflecting means is imaged by scanning optical means 6 onto a surface 7 to be scanned so as to scan the surface to be scanned. The scanning optical means has at least one optical surface that has a fine structure grating 8 having a grating pitch smaller than the wavelength of the light flux emitted from said laser light source.

Abstract: The optical element has a microstructure lattice formed on at least one optical surface. In the optical element, the microstructure lattice is formed from an arrangement for adjusting a change in an amount of light transmitted which is caused as an incidence angle of a light beam changes from a central portion to a peripheral portion.

Abstract: In an image reading apparatus, an original placed on an original glass table is illuminated by a light source, and a light beam corresponding to image information of an original surface illuminated with the light source is focused on a sensor by an imaging optical system. The sensor for reading image information is so disposed as not to be perpendicular to an optical axis of the imaging optical system. In an apparatus, &thgr;i≧sin−1(NAi) is satisfied, where &thgr;i is the tilt angle of the sensor with respect to the optical axis of the imaging optical system, and NAi is the numerical aperture of the imaging optical system on a sensor side.

Abstract: At least one beam emitted from a light source is deflected by a deflector, and the beam deflected by the deflector is imaged on a surface to be scanned by imaging optical system having a diffracting surface on at least one surface thereof. Of diffracted lights diffracted by the diffracting surface when the surface to be scanned is scanned by the beam, relative to diffracted light of an order used to form a spot on the surface to be scanned, the expanse of the stray light of one of unnecessary diffracted lights of the other orders undergoing surface-reflection by a refracting surface of the imaging optical system upon incidence on the surface to be scanned is designed to be wider in the sub-scanning direction than in the main scanning direction.

Abstract: A multi-beam scanning optical system includes a light source having a plurality of light-emission points, an incident optical system for guiding a plurality of light beams emitted from the light source to a deflector, a scanning optical system for forming the plurality of light beams reflected/deflected by the deflector into images on a scanned surface, and a synchronization detection device in which a part of the plurality of light beams from the deflector are reflected at a predetermined angle in a sub-scanning cross-section by using a mirror to be scanned on a surface of a slit member and to be guided to a surface of a synchronization detection element via the slit member, and a timing at a scanning start position on the scanned surface is controlled by using a signal from the synchronization detection element. The slit member is positioned such that a plurality of light beams scanned on a surface of a slit opening are substantially vertically scanned on the slit opening.

Abstract: A scanning optical apparatus includes incident optical system for causing at least one light beam emitted from a light source to be incident on a deflection device and image formation optical system including at least one refractive optical element and at least one diffraction optical element for imaging said at least one light beam reflected and deflected by the deflection device on a surface to be scanned. The diffraction optical element has at least one of an incident surface having a convex shape in a sub-scanning cross-section facing the deflection device and an exit surface having a convex shape in the sub-scanning cross-section facing the surface to be scanned.

Abstract: A scanning optical apparatus which includes incident optical system for causing at least one light beam emitted by light source onto a deflector, and image forming optical system, having at least one diffraction surface, for imaging the at least one light beam reflected and deflected by the deflector on a surface to be scanned. The apparatus further includes limiting member, inserted in the optical path between the diffraction surface of the image forming optical system and the surface to be scanned, for limiting unnecessary diffraction light of another order with respect to diffraction light of an order used to form a spot on the surface to be scanned from among the diffraction light diffracted by the diffraction surface.

Abstract: A scanning optical device includes a light source having a plurality of light emitting points, a deflector for deflecting a plurality of light beams emitted from the light source, and an optical system for guiding the plurality of light beams emitted from the light source onto a surface to be scanned. In the scanning optical device, a predetermined condition is satisfied among a light emitting interval between the plurality of light emitting points, a tilt angle of the plurality of light emitting points, juxtaposed in the main scanning direction, and inclined in the sub scanning direction about the optical axis as the center, the beam interval of the plurality of light beams on the surface to be scanned, and imaging magnifications of the optical system in the main and sub scanning directions.