Abstract: A scanning optical system includes converges, with a single lens, a divergent luminous flux, which is deflected in a main scanning direction by an optical deflector, on a surface of a scan target. The lens has two surfaces in a biconvex shape in both the main scanning direction and a sub-scanning direction, and at least one of the surfaces is a toric surface in which a line that connects, on a cross section in the main scanning direction, centers of curvature in a cross section in the sub-scanning direction is nonlinear, and change of the curvature of the toric surface in the cross section in the sub-scanning direction along the main scanning direction is asymmetric with an optical axis of the lens. The surfaces are anamorphic surfaces.

Abstract: A communications device is provided which receives data frames in FIR communications mode even if the device has failed to normally receive a connect frame in SIR communications mode. A communications device according to the invention includes an incoming frame processing section for receiving an SNRM frame and UI frames in different frame formats. The SNRM frame contains a setting for a connection for data communications. The UI frames contain data. The communications device also includes a reception processing section and connect command notification sections. The reception processing section renders a light reception section stand by for reception of the UI frames in FIR communications mode. The connect command notification sections generate a connect command for output to an upper layer. The connect command enables establishing of the same connection when a data frame is received from another communications device as when a connect frame was received from the other communications device.

Abstract: An optical scanning device includes a first optical element that converts a cross-section shape of a light beam from a semiconductor laser to a desired shape; a second optical element that guides the light beam output from the first optical element to an optical deflector that deflects the light beam; and a third optical element that gathers the light beam deflected by the optical deflector onto a surface to be scanned to form a light spot thereby optically scanning the surface. At least one of the first optical element, the second optical element, and the third optical element includes a resin-made lens, at least one of the resin-made lenses has a power diffracting surface, and a surface shape of at least one of power diffracting surfaces is formed so that a power of a diffracting portion and a power of a refractive portion are cancelled out.

Abstract: An optical scanning apparatus includes a semiconductor laser and a first optical element that are fixed on a single continuous member. A second optical element, which is a diffraction optical element, has a diffracting surface in which an elliptical groove is formed and which includes a diffracting portion power such that a change in the beam waist position in a main scan direction and a sub-scan direction due to temperature variation in the optical scanning apparatus becomes substantially zero. The member on which the semiconductor laser and the first optical element are fixed has a linear coefficient of expansion such that the ellipticity of the elliptical groove increases.

Abstract: An optical scanning device includes a first optical element that converts a cross-section shape of a light beam from a semiconductor laser to a desired shape; a second optical element that guides the light beam output from the first optical element to an optical deflector that deflects the light beam; and a third optical element that gathers the light beam deflected by the optical deflector onto a surface to be scanned to form a light spot thereby optically scanning the surface. At least one of the first optical element, the second optical element, and the third optical element includes a resin-made lens, at least one of the resin-made lenses has a power diffracting surface, and a surface shape of at least one of power diffracting surfaces is formed so that a power of a diffracting portion and a power of a refractive portion are cancelled out.

Abstract: An optical scanning device includes a first optical element that converts a cross-section shape of a light beam from a semiconductor laser to a desired shape; a second optical element that guides the light beam output from the first optical element to an optical deflector that deflects the light beam; and a third optical element that gathers the light beam deflected by the optical deflector onto a surface to be scanned to form a light spot thereby optically scanning the surface. At least one of the first optical element, the second optical element, and the third optical element includes a resin-made lens, at least one of the resin-made lenses has a power diffracting surface, and a surface shape of at least one of power diffracting surfaces is formed so that a power of a diffracting portion and a power of a refractive portion are cancelled out.

Abstract: A coupling lens arranged on an optical path of an optical beam from a VCSEL, which has a refraction plane and a diffraction plane that respectively change a power according to a temperature change and suppresses a beam-waist position change in a main-scanning direction and a sub-scanning directions on the scanning surface caused by the temperature change, by a wavelength change of the optical beam caused by power changes of the refraction plane and the diffraction plane and the temperature change. A deflecting unit deflects the optical beam that passed through the coupling lens. A scanning optical system condenses a deflected optical beam on the scanning surface.

Abstract: An optical scanner has light source units spaced from each other along a first direction and having optical axes parallel to each other. Positions from which the light beams are emitted are spaced from each other by a predetermined distance at least along a predetermined direction. The optical scanner also includes a deflection unit that deflects the light beams together and scans the light beams along a second direction perpendicular to the first direction. The optical scanner also has imaging units that form an image with each of the light beams on a surface and a housing unit that holds the light source units, the deflection units, and the imaging units.

Abstract: A first optical system guides a light beam from a light source to an optical deflector, and a second optical system converges the light beam deflected by the optical deflector on a surface to be scanned. The first optical system includes at least one resin lens having a diffractive surface. The second optical system includes at least one resin optical element. A beam diameter depth in a main scanning direction, Wm, that can have a maximum intensity of 1/e2, satisfies conditions ?m1+?m2+?m3??d1×(f2/f1)2<Wm/40??(1) ?d1>0 and ?m2<0.

Abstract: An optical axis of at least one surface of a resin-made diffracting lens is shifted in a main scanning direction with respect to an incident beam. A synchronous detection can cancel a problem of a misalignment in the main scanning direction due to a temperature variation. A light reflected from a second surface of the resin-made diffractive lens condenses on a position that is displaced in an optical axis direction from an optical beam outgoing point of a semiconductor laser, and thereby the light reflected again from the semiconductor laser does not form an image on a scanned surface and an impact on the image becomes low.

Abstract: A diffractive-optical element that is transparent includes a diffraction surface that is formed by a step. A width of the step is set substantially equal to a common multiple of ?i/{n(?i)?1} for two or more wavelengths, where ?i (i=1, 2, . . . ) is a wavelength and n(?i) is a refractive index with respect to the wavelength ?i.

Abstract: A coupling lens arranged on an optical path of an optical beam from a VCSEL, which has a refraction plane and a diffraction plane that respectively change a power according to a temperature change and suppresses a beam-waist position change in a main-scanning direction and a sub-scanning directions on the scanning surface caused by the temperature change, by a wavelength change of the optical beam caused by power changes of the refraction plane and the diffraction plane and the temperature change. A deflecting unit deflects the optical beam that passed through the coupling lens. A scanning optical system condenses a deflected optical beam on the scanning surface.

Abstract: A synchronous detector detects timing of scanning by an optical scanner in an image forming apparatus. The optical scanner has a light source that emits a light beam, a deflecting unit that deflects the light beam, a scanning optical element that focuses the light beam deflected by the deflecting unit onto a surface to be scanned. The synchronous detector includes a photoreceiver, and a synchronous optical element that focus the light beam deflected by the deflecting unit onto the photoreceiver. The synchronous optical element satisfies a relationship fm<fd, where fm is a composite focal length of the scanning optical element in a main scanning direction, and fd is a composite focal length of the synchronous optical element in the main scanning direction.

Abstract: An optical scanning device includes a light source having light emitting points for emitting light beams, a coupling optical element that couples the light beams, a deflecting unit that deflects and scans the light beams, and a scanning optical system that focus the light beams to form an image. The optical scanning device satisfies the following condition: F tan(?/2)+A<D/0.7 where A is the maximum distance between the light emitting points and an optical axis of the coupling optical element, ? is a divergence angle (full-width half-maximum) of the light beams, F is a focal length of the coupling optical element, and D is an effective radius of the coupling optical element.

Abstract: A multi-beam scanning device is disclosed that is able to realize a stable and small beam spot and realize stable scanning line intervals between plural light beams. The multi-beam optical scanning device includes a first optical system which has a first lens for coupling the light beams from the light sources, and a second lens which is an anamorphic element having power at least in a sub scanning direction and for guiding the light beams from the first lens to the deflection unit; and a second optical system. At least the second lens includes a diffracting surface having power.

Abstract: An optical scanning device includes a first optical system for guiding light beams emitted from a plurality of light emitting units to an optical deflector, and a second optical system for focusing the light beams to optically scan a surface to be scanned. At least one of the first optical system and the second optical system includes a resin lens having a diffractive surface. The diffractive surface includes a diffractive portion and a refractive portion. A power of the diffractive portion and a power of the refractive portion cancel each other.

Abstract: A scanning optical system condensing a beam deflected by an optical deflector so as to form a beam spot on a surface to be scanned, comprises two lenses. A lens on the side of optical deflector has a negative refracting power in sub-scanning direction. A lens on the side of surface to be scanned has a positive refracting power in the sub-scanning direction. At least one lens surface of the lens surfaces of the two lenses is such that a shape in a sub-scanning section thereof is a non-arc shape.

Abstract: An optical scanning device includes a first optical element that converts a cross-section shape of a light beam from a semiconductor laser to a desired shape; a second optical element that guides the light beam output from the first optical element to an optical deflector that deflects the light beam; and a third optical element that gathers the light beam deflected by the optical deflector onto a surface to be scanned to form a light spot thereby optically scanning the surface. At least one of the first optical element, the second optical element, and the third optical element includes a resin-made lens, at least one of the resin-made lenses has a power diffracting surface, and a surface shape of at least one of power diffracting surfaces is formed so that a power of a diffracting portion and a power of a refractive portion are cancelled out.

Abstract: A multi-beam scanning device is disclosed that is able to realize a stable and small beam spot and realize stable scanning line intervals between plural light beams. The multi-beam optical scanning device includes a first optical system which has a first lens for coupling the light beams from the light sources, and a second lens which is an anamorphic element having power at least in a sub scanning direction and for guiding the light beams from the first lens to the deflection unit; and a second optical system. At least the second lens includes a diffracting surface having power.

Abstract: A multi-beam optical scanner, in which a lateral magnification ? in a composite system of an optical system between the light source for a multi-beam and the scanned surface satisfies the condition: 2<??8.5, and a plurality of light spots on the scanned surface execute optical scanning of the scanning lines adjacent to each other.