Abstract: An optical element for diffracting a light beam includes a diffractive surface having a one-dimensional periodic structure. The periodic structure and transmissive diffraction efficiencies T?p(m) and T?s(m) of p- and s-polarized lights on the diffractive surface in relation to a diffraction order m satisfy the following conditions: 0.5?<P<1.5???(1) |{T?p(m)?T?s(m)}/{T?p(m)+T?s(m)}|<0.1,??(2) where P is a period of the periodic structure, and ? is a wavelength of the used light beam.

Abstract: An aperture has an aperture opening that transmits a predetermined portion of a light beam. A phase optical element changes a phase of a portion of a light beam. A scanning lens focuses the light beam into a beam spot on a scanning surface. The phase optical element has a function of increasing light intensity of a side-lobe of the scanning beam near the scanning surface. The aperture opening is set to satisfy 0.03?(SR?SA)/SR?0.20, where SR and SA are areas of a rectangle circumscribing the aperture opening and the aperture opening, respectively. The function of the phase optical element and the aperture expand a depth allowance of the beam spot.

Abstract: At least one of a coupling lens and a cylindrical lens has a diffraction lens surface having a ring-band structure with a height h between adjacent ring-bands. The diffraction lens surface has an area A having a shape similar to that of the ring-band structure with a height h?, where h?h?. The ring-band structure has a function of correcting a fluctuation in focal position of the scanning beam on the scanning surface, and the area A has a function of expanding a focal depth of a light spot on the scanning surface.

Abstract: A coupling optical system that includes a coupling lens, a linear-image forming lens, and an aperture couples light beams emitted from a light source to form a light flux. A deflector scans the light flux in a main scanning direction to form an image as a scanning line on a surface to be scanned through first and second scanning lenses. While an image is being formed on an image plane, the image plane is moved in a direction perpendicular to the main scanning direction. The linear-image forming lens has a diffractive optical surface capable of collecting light in a sub-scanning direction. The temperature dependence d?/dT of wavelength of the light source satisfies d?/dT<0.15.

Abstract: A compact optical scanning apparatus capable of desirably correcting an f characteristic, a field curvature, and other aberrations, and an image forming apparatus using the same, which includes an incident optical system (LA) for guiding a beam from a light source (1) to a deflector (4) and an imaging optical system (LB) for guiding the beam to a scanning surface (7), wherein a scanning field angle region where 1<3 and 2<3 are satisfied exists within effective scanning field angle region, where in a main scanning cross section and for a scanning field angle 1, 2 represents an angle between a principal ray of beam incident on an optical element included in the imaging optical system and located closest to the scanning surface and an optical axis of the imaging optical system and 3 an angle between a principal ray of a beam from the optical element and the optical axis.

Abstract: An optical scanning apparatus including a light source, deflection unit configured to deflect a light flux emitted by the light source, a first optical system configured to condense a divergent light flux emitted by the light source, a second optical system configured to focus the deflected light flux on a target scanning face, where the wavelength of the light flux is short, and the first and second optical systems include respective refractive optical elements.

Abstract: A curvature-adjustment device used for an optical scanner that includes an optical beam emission unit to emit an optical beam, a deflection unit to deflect the optical beam in a main scanning direction and a mirror to reflect the optical beam. The curvature-adjustment device corrects a curvature of a main scanning line on a surface of a scanning target, and includes a support unit to support the mirror at an end thereof by contacting a rear surface of the mirror, an edge-positioned adjustment unit to curve the mirror by exerting a first force, a center-positioned adjustment unit to curve the mirror reversely in a direction to which the edge-positioned adjustment unit curves the mirror by providing a second force perpendicular to the reflecting surface at a center of the mirror, and a fine adjustment unit to adjust the strength of the first force depending on the strength of the second force.

Abstract: Barcode scanning device (3) includes a rotatable polygon mirror (27) and a first fixed reflection mirror (33). The polygon mirror (27) comprises a first reflection surfaces (c), (e) and a second reflection surfaces (a), (b), (d), (f). The first reflection surfaces (c), (e) reflect laser light and thus emitting first scanning light in a range of ±20° with respect to an optical axis (29). The second reflection surfaces (a), (b), (d), (f) reflect laser light and thus emitting second scanning light in a range larger than ±20° with respect to an optical axis (29). The first fixed reflection mirror (33) reflects the first scanning light and second scanning light forming scanning patterns in an object readable area. These scanning patterns are composed of a plurality of second scanning lines each parallel with other and first scanning lines disposed between the second scanning lines.

Abstract: A light scanning apparatus including a semiconductor laser which emits a light beam having a wavelength equal to or less than 450 nm, an incidence optical system which makes the light beam, emitted from the semiconductor laser, incident on a deflector for scanning in deflection, an imaging optical system which images the light beam scanned in deflection by the deflector to a surface to be scanned, a light intensity detector which detects fluctuations in spectral transmittances of the incidence optical system and of the imaging optical system, which are caused as a concomitant of a fluctuation in wavelength of the light beam which is emitted from the semiconductor laser and passes through the incident optical system and the imaging optical system, and an automatic power controller which automatically controls a light emission output of the semiconductor laser on the basis of a detection value detected by the light intensity detector.

Abstract: An optical scanning device includes a light source device, a deflector, an input optical system for directing a light beam from the light source device onto the deflector, and an imaging optical system for imaging a light beam scanningly deflected by a deflecting surface of the deflector, upon a scan surface to be scanned, wherein, in a sub-scan section, a light beam directed from the input optical system toward the deflecting surface of the deflector is incident thereon at a finite angle with respect to a plane which is orthogonal to a rotational axis of the deflector, wherein the imaging optical system includes at least one molded imaging lens, and wherein a shape within a sagittal section of at least one lens surface, of lens surfaces of the at least one imaging lens, is non-arcuate, and a sagittal curvature in a light beam passage region has an extreme value.

Abstract: In an image forming apparatus according to the invention, an optical beam scanning apparatus of an overillumination scanning optical system includes a laser, a pre-deflection optical system, a polygon mirror, and a post-deflection optical system, wherein the post-deflection optical system includes at least one optical element configured by allowing a resin to flow into a molding die through a gate opening provided in advance to the molding die and then molding the resin into a prescribed shape; and in the optical element, a side corresponding to a side of the gate opening through which the resin flows is provided to a light incidence side where the luminous flux enters into the polygon mirror.

Abstract: A three-dimensional input apparatus includes a lens L1 for converting angular information about light rays from a object, a focusing element L3 for focusing the light rays from the object to the vicinities of an array R of photoelectric elements, and a lens L2 for performing conversion into a real image near the surface of the focusing element L3. The lens L2 is present between the lens L1 and focusing element L3. The array R records light as image signal sequentially. A driver portion drives the optical system and scans light ray information about the object.

Abstract: An optical scanning device which corrects rotation distortion around an optical axis of the light beam is provided while a housing is reduced in site and is arranged to be manufactured accurately. The optical scanning device includes a pre-deflection optical system that shapes a light beam emitted from a light source into a predetermined sectional shape, a polygon mirror that deflects an incident light beam with plural reflection surfaces arrayed in a rotating direction and scans the light beam on a scanning object, and a folding mirror that deflects the light beam, which is shaped by the pre-deflection optical system, with a reflection surface and guides the light beam to the reflection surfaces of the polygon mirror.