Abstract: A scanning optical system using a short-wavelength light of 500 nm or less uses a reflecting mirror having a higher absolute reflectivity and having reduced wavelength and angle dependences. Divergent ray of light emitted from a semiconductor laser is converted into an approximately parallel light beam by a collimator lens and the diameter of the light flux is reduced by an aperture before travel to a polygon mirror. The light beam from the polygon mirror passes through scanning lenses to form a small spot at any point in the entire scanning area. The semiconductor laser is a gallium nitride semiconductor laser having an oscillation wavelength of 408 nm. The polygon mirror has such a characteristic that, if the complex refractive index N of a metallic film contributing to a reflection characteristic of the reflecting mirror is defined as N(?)=n(?)?ik(?), then k(?)>?{square root over ((?n(?)2+18n(?)?1))}{square root over ((?n(?)2+18n(?)?1))} is satisfied.

Abstract: At least one exemplary embodiment is directed to an optical scanning apparatus that employs a short wave light source to constantly maintain a spot having a tiny diameter, even when an environmental temperature change occurs, by employing a lens and/or a diffractive optical element.

Abstract: An optical scanning apparatus includes a light source unit, a deflecting unit for deflecting and scanning a light beam from the light source unit, and a scanning optical system for scanning the light beam deflected by the deflecting unit on a surface to be scanned. The scanning optical system includes a diffraction portion having an aspherical function in a sub-scanning direction.

Abstract: Disclosed is an optical scanning device which includes a light source device, a deflecting system for deflecting a light beam emitted from the light source device, and a scanning optical system for scanning a surface to be scanned, with the light beam deflected by the deflecting system, wherein the scanning optical system includes a scanning optical element disposed so that, with respect to a sub-scan direction, a principal ray of the deflected light beam passes a portion other than an optical axis, wherein the scanning optical element has a sagittal aspherical amount changing surface in which an aspherical amount of a sagittal changes along a main scan direction of the scanning optical element, and wherein, throughout the whole surface to be scanned, the position in the sub-scan direction upon which the deflected light beam impinges is made even.

Abstract: A scanning optical system using a short-wavelength light of 500 nm or less uses a reflecting mirror having a higher absolute reflectivity and having reduced wavelength and angle dependences. Divergent ray of light emitted from a semiconductor laser is converted into an approximately parallel light beam by a collimator lens and the diameter of the light flux is reduced by an aperture before travel to a polygon mirror. The light beam from the polygon mirror passes through scanning lenses to form a small spot at any point in the entire scanning area. The semiconductor laser is a gallium nitride semiconductor laser having an oscillation wavelength of 408 nm. The polygon mirror has such a characteristic that, if the complex refractive index N of a metallic film contributing to a reflection characteristic of the reflecting mirror is defined as N(?)=n(?)?ik(?), then k(?)>?{square root over ((?n(?)2+18n(?)?1))} is satisfied.

Abstract: At least one exemplary embodiment is related to an optical scanner, which includes at least one optical element that can separate ghost light from scanning light facilitating the blocking of the ghost light.

Abstract: Disclosed is an optical scanning device which includes a light source device, a deflecting system for deflecting a light beam emitted from the light source device, and a scanning optical system for scanning a surface to be scanned, with the light beam deflected by the deflecting system, wherein the scanning optical system includes a scanning optical element disposed so that, with respect to a sub-scan direction, a principal ray of the deflected light beam passes a portion other than an optical axis, wherein the scanning optical element has a sagittal aspherical amount changing surface in which an aspherical amount of a sagittal changes along a main scan direction of the scanning optical element, and wherein, throughout the whole surface to be scanned, the position in the sub-scan direction upon which the deflected light beam impinges is made even.

Abstract: This invention provides an optical scanning apparatus in which the degree of sensitivity of the bending of a scanning line on a surface to be scanned resulting from the disposition error of a scanning optical system is reduced, whereby good images can always be obtained, and an image forming apparatus using the same. The optical scanning apparatus has deflecting means for deflecting a beam emitted from light source means, and a scanning optical system having a plurality of scanning lenses for directing the beam onto the surface to be scanned, and a first scanning lens La is such that the shape thereof in a main scanning cross section is a meniscus shape having positive refractive power, and satisfies the condition that d1/fm<0.06, where fm is the focal length of the scanning optical system in the main scanning cross section, and d1 is the central thickness of the first scanning lens, and a second scanning lens is such that.

Abstract: An optical scanning apparatus in which streaks in an image or unevenness in density of an image caused by influences of dusts, scratches and toner etc on the surface of a reflecting member are unlikely to occur and excellent images can be always obtained and an image forming apparatus equipped with such an optical scanning apparatus are to be achieved. The apparatus comprises a first optical system for guiding a light beam emitted from light source unit to deflecting unit, the deflecting unit for reflecting and deflecting the light beam from the first optical system, a second optical system for guiding the light beam reflected and deflected by the deflecting unit onto a surface to be scanned through reflecting unit including n (n is an integer equal to or larger than 1) reflecting members.

Abstract: A color image reading apparatus has a 3-line sensor formed by setting a plurality of line sensors on a single substrate, an imaging lens for imaging an object, a diffraction grating which is inserted in the optical path between the imaging lens and 3-line sensor and color-separates a light beam coming from the object into a plurality of color light beams, and a first cylinder unit which is inserted in the optical path between the object and the imaging lens, and temporarily images the object in the sub-scanning direction in the optical path before the imaging lens.

Abstract: An image sensing device includes: a light source, a recording member on which an image is formed and conveyed in one direction, illumination system for causing a light beam emitted from the light source to obliquely illuminate the recording member and, imaging system for condensing specularly reflected light from the image on the recording member and causing the reflected light to travel to a surface of a photodetector, so that the image sensing device obtains positional information of the image on the recording member on the basis of a signal obtained by the photodetector. When the amount of displacement of the recording member in a vertical direction during conveyance of the recording member is d, an angle between the optical axis of the imaging system and a normal to the recording member is ? (degrees), and resolution of the image formed on the recording member is R (dpi), the components are set so that d·tan ?<(25.4/R)×1000 is satisfied.

Abstract: There is provided a diffraction grid which is easily produced without reducing a grid size. There is provided an optical scanning device having effects such as a chromatic aberration correction and a temperature compensation even when a short wavelength light source having a wavelength of 500 nm or less is used, and an image forming apparatus using the optical scanning device. In the optical scanning device having the diffraction grid, for which the short wavelength light source having a wavelength of 500 nm or less is used, a design order of the diffraction grid is set to a diffraction order equal to or larger than a second order to obtain a grid shape which is easily formed.

Abstract: An optical scanning device is provided, which includes: a light source unit for emitting at least one light flux having a wavelength equal to or smaller than 500 nm; a deflection unit for deflecting at least one of the light fluxes emitted from the light source unit; and a scanning optical system for imaging the light flux deflected by the deflection unit onto a surface to be scanned. In the optical scanning device, the scanning optical system includes at least two lenses including a glass lens and a plastic lens, each of which has an opposite sign of power, and chromatic aberration of magnification in a main scanning direction in the optical scanning device is corrected to be equal to or smaller than 40 ?m in the case where a difference of wavelengths in the light flux emitted from the light source unit is set to 5 nm.

Abstract: It is an object of this invention to provide a light scanning device capable of suppressing scanning line bending to a low level, which is caused by the arrangement error of a single-element lens serving as an imaging optical element, and an image forming apparatus using the device. In order to achieve the object, according to this invention, an imaging optical system is formed from a single-element lens, and the sectional shapes of the incident and exit surfaces in the main scanning direction are non-arcuated, and the power in the sub scanning direction substantially concentrates on the exit surface. The non-arcuated shape (curvature) of the exit surface in the main scanning direction is so determined as to make the magnification in the sub scanning direction uniform.

Abstract: A scanning optical system using a short-wavelength light of 500 nm or less uses a reflecting mirror having a higher absolute reflectivity and having reduced wavelength and angle dependences. Divergent ray of light emitted from a semiconductor laser is converted into an approximately parallel light beam by a collimator lens and the diameter of the light flux is reduced by an aperture before travel to a polygon mirror. The light beam from the polygon mirror passes through scanning lenses to form a small spot at any point in the entire scanning area. The semiconductor laser is a gallium nitride semiconductor laser having an oscillation wavelength of 408 nm. The polygon mirror has such a characteristic that, if the complex refractive index N of a metallic film contributing to a reflection characteristic of the reflecting mirror is defined as N(&lgr;)=n(&lgr;)−ik(&lgr;), then k(&lgr;)>{square root}{square root over ((−n(&lgr;)2+18n(&lgr;)−1))} is satisfied.

Abstract: Disclosed in an optical scanning apparatus which includes a deflecting unit comprised of a rotary polygon mirror for deflecting a light beam radiated from a light source unit, and a scanning optical system for guiding the light beam deflected by the deflecting unit to a surface to be scanned. In the optical scanning apparatus, individual elements are set such that a diameter of a circumscribed circle of the rotary polygon mirror, the number of deflecting facets of the rotary polygon mirror, an incident angle of the light beam on the deflecting facet at the time when the light beam scans a scanning center, a maximum swing angle of the deflecting facet at the time when an effective scanning range is scanned, and a magnification of the scanning optical system in a sub scanning section can satisfy a predetermined condition, thereby reducing an unevenness of pitches due to a deflecting-facet fall of the rotary polygon mirror, and readily achieving a highly precise and fine image.

Abstract: It is an object of this invention to provide a light scanning device capable of suppressing a scanning line bend to a low level, which is caused by the arrangement error of a single-element lens serving as an imaging optical element, and an image forming apparatus using the device. In order to achieve the object, according to this invention, an imaging optical system is formed from a single-element lens, and a sectional shape of an exit surface in the main scanning direction is an arcuated shape. The power in the sub scanning direction substantially concentrates on the exit surface having an arcuated sectional shape in the main scanning direction, and the arcuated shape (curvature) in the main scanning direction is so determined as to make the magnification in the sub scanning direction uniform.

Abstract: Disclosed is a scanning optical device and an image forming apparatus using the same, wherein the scanning optical device includes a scanning optical element provided by a single lens. In relation to a predetermined one of two optical surfaces of the single lens having a larger refractive power in a minor scan direction on an optical axis, the shape of optical surface of the single lens is determined so as to satisfy a relation 0.9≦øm/øp≦ømx/øpx=1.0≦1.1øm/øp where øp is a refractive power of the single lens in a minor scan direction on the optical axis, øm is a refractive power of the single lens in the minor scan direction at a most abaxial point, øpx is a refractive power at the predetermined optical surface of the single lens in the minor scan direction on the optical axis, and ømx is a refractive power at the predetermined optical surface of the single lens in the minor scan direction at a most abaxial point.

Abstract: A scanning optical system using a short-wavelength light of 500 nm or less uses a reflecting mirror having a higher absolute reflectivity and having reduced wavelength and angle dependences. Divergent ray of light emitted from a semiconductor laser is converted into an approximately parallel light beam by a collimator lens and the diameter of the light flux is reduced by an aperture before travel to a polygon mirror. The light beam from the polygon mirror passes through scanning lenses to form a small spot at any point in the entire scanning area. The semiconductor laser is a gallium nitride semiconductor laser having an oscillation wavelength of 408 nm. The polygon mirror has such a characteristic that, if the complex refractive index N of a metallic film contributing to a reflection characteristic of the reflecting mirror is defined as N(&lgr;)=n(&lgr;)−ik(&lgr;), then k(&lgr;)>{square root over ((−n(&lgr;)2+18n(&lgr;)−1))} is satisfied.

Abstract: This invention provides an optical scanning apparatus in which the degree of sensitivity of the bending of a scanning line on a surface to be scanned resulting from the disposition error of a scanning optical system is reduced, whereby good images can always be obtained, and an image forming apparatus using the same.