Abstract: A first group optical system having a positive refracting power, a second group optical system having a negative refracting power, and a third group optical system having a positive refracting power are sequentially arranged from an object side toward an image side. At least the first group optical system and the third group optical system move so that a distance between the first group optical system and the second group optical system becomes minimum at short focal-length side, and a distance between the second group optical system and the third group optical system becomes minimum at long focal-length side. The third group optical system includes a triplet lens formed with a negative lens, a positive lens, and a negative lens.

Abstract: A first group optical system having a positive refracting power, a second group optical system having a negative refracting power, and a third group optical system having a positive refracting power are sequentially arranged from an object side toward an image side. At least the first group optical system and the third group optical system move so that a distance between the first group optical system and the second group optical system becomes minimum at short focal-length side, and a distance between the second group optical system and the third group optical system becomes minimum at long focal-length side. The third group optical system includes a triplet lens formed with a negative lens, a positive lens, and a negative lens.

Abstract: An optical scanner includes at least a pair of optical scanning systems and a light deflector used in common between the optical scanning systems, each optical scanning system having a scan lens for guiding the beam deflected from the light deflector onto the associated scanned plane. One of the optical scanning systems has a first reference reflecting position on the light deflector, and the other optical scanning system has a second reference reflecting position on the light deflector. The first and second reference reflecting positions are asymmetric with respect to the reference plane of the optical scanner. The scan lenses of said pair of optical scanning systems are arranged to be symmetric with respect to a line passing through the rotational center of the light deflector and extending in parallel to the scanned planes.

Abstract: A first group optical system having a positive refracting power, a second group optical system having a negative refracting power, and a third group optical system having a positive refracting power are sequentially arranged from an object side toward an image side. At least the first group optical system and the third group optical system move so that a distance between the first group optical system and the second group optical system becomes minimum at short focal-length side, and a distance between the second group optical system and the third group optical system becomes minimum at long focal-length side. The third group optical system includes a triplet lens formed with a negative lens, a positive lens, and a negative lens.

Abstract: An optical scanning apparatus includes light sources, an aperture having, and coupling lenses. Numbers of the light sources and the coupling lenses are equal to each other and the apparatus satisfies an inequality 12.7<(D×?0×m0×dpi)/(2×NA)<38.1 and an equation ?0=(?+???)/(n?1), wherein D represents a width of the slit of the aperture, ?0 represents a beam open angle, mo represents a total lateral magnification ratio, dpi represents a number of dots per inch, NA represents a numerical aperture, ?+ represents a positive open angle, ?? represents a negative open angle, and n represents the number. Further, an image forming apparatus using this optical scanning apparatus and an image forming method are provided.

Abstract: An optical scanning device for scanning plural surfaces including a plurality of laser light units each configured to emit a laser beam, a deflecting device configured to deflect the laser beams from the plurality laser light units to sweep a plurality of predetermined planes, respectively, and a scanning image forming optical unit configured to project the laser beams deflected by the deflecting device on the plural surfaces, respectively, to scan the plural surfaces with the laser beams. The scanning image forming optical unit includes a plurality of optical detecting devices configured to detect the laser beams and a first plurality of reflecting devices positioned to reflect at least two laser beams of the laser beams toward one of the plurality of optical detecting devices.

Abstract: An optical scanning apparatus includes light sources, an aperture having, and coupling lenses. Numbers of the light sources and the coupling lenses are equal to each other and the apparatus satisfies an inequality 12.7 <(D×?0×m0×xdpi)/(2×NA) <38.1 and an equation ?0=(?+???)/(n?1), wherein D represents a width of the slit of the aperture, ?0represents a beam open angle, mo represents a total lateral magnification ratio, dpi represents a number of dots per inch, NA represents a numerical aperture, ?+ represents a positive open angle, ?? represents a negative open angle, and n represents the number. Further, an image forming apparatus using this optical scanning apparatus and an image forming method are provided.

Abstract: A first group optical system having a positive refracting power, a second group optical system having a negative refracting power, and a third group optical system having a positive refracting power are sequentially arranged from an object side toward an image side. At least the first group optical system and the third group optical system move so that a distance between the first group optical system and the second group optical system becomes minimum at short focal-length side, and a distance between the second group optical system and the third group optical system becomes minimum at long focal-length side. The third group optical system includes a triplet lens formed with a negative lens, a positive lens, and a negative lens.

Abstract: Providing a fixing structure for parts of optical element by which fixing of parts of optical element with high accuracy can be achieved after positional adjustment in axes with an arrangement the positional adjustment in axes of parts of optical element is easily achieved before the fixing of the parts of optical element. The fixing structure comprises lens 3 having an edge surface which is a side surface surrounding a light beam passing surface; an intermediate holding member 5 having a first attaching surface 5a which is facing to the side surface and having a second attaching surface 5b which has a different angle from said first attaching surface 5a; and a housing 2 having an attaching surface 2c which is facing to the second attaching surface 5b; the housing 2 and the lens 3 which has been adjusted the positional relation to the housing 2 are adhered and fixed through the intermediate holding member 5.

Abstract: An optical scanner includes at least a pair of optical scanning systems and a light deflector used in common between the optical scanning systems, each optical scanning system having a scan lens for guiding the beam deflected from the light deflector onto the associated scanned plane. One of the optical scanning systems has a first reference reflecting position on the light deflector, and the other optical scanning system has a second reference reflecting position on the light deflector. The first and second reference reflecting positions are asymmetric with respect to the reference plane of the optical scanner. The scan lenses of said pair of optical scanning systems are arranged to be symmetric with respect to a line passing through the rotational center of the light deflector and extending in parallel to the scanned planes.

Abstract: An optical scanning apparatus includes light sources, an aperture having, and coupling lenses. Numbers of the light sources and the coupling lenses are equal to each other and the apparatus satisfies an inequality 12.7 <(Dx&bgr;oxmoxdpi)/(2xNA) <38.1 and an equation &bgr;o=(&bgr;+−&bgr;)/(n-1), wherein D represents a width of the slit of the aperture, &bgr;orepresents a beam open angle, mo represents a total lateral magnification ratio, dpi represents a number of dots per inch, NA represents a numerical aperture, &bgr;+represents a positive open angle, &bgr; represents a negative open angle, and n represents the number. Further, an image forming apparatus using this optical scanning apparatus and an image forming method are provided.

Abstract: A method for communication making a processing by means of one of the information units or a combination of the information units when it is instructed from a user terminal to display contents and procedure of a communication or to totalize contents of the communication, or when it is instructed from a manager terminal of a field of the communication to provide a function of the communication corresponding to an object or stage of the communication, the processing corresponding to the instruction.

Abstract: An optical scanning device for scanning plural surfaces including a plurality of laser light units each configured to emit a laser beam, a deflecting device configured to deflect the laser beams from the plurality laser light units to sweep a plurality of predetermined planes, respectively, and a scanning image forming optical unit configured to project the laser beams deflected by the deflecting device on the plural surfaces, respectively, to scan the plural surfaces with the laser beams. The scanning image forming optical unit includes a plurality of optical detecting devices configured to detect the laser beams and a first plurality of reflecting devices positioned to reflect at least two laser beams of the laser beams toward one of the plurality of optical detecting devices.

Abstract: Providing a fining structure for parts of optical element by which fiing of parts of optical element with high accuracy can be achieved aer positional adjustment in axes with an arrangement the positional adjustment in axes of parts of optical element is easily achieved before the fixingg of the pars of optical element. The fing structure comprises lens 3 having an edge surface which is a side surface surrounding a light beam passing surface; an intermediate holding member 5 having a first attaching surface 5a which is facing to the side surface and having a second attaching surface 5b which has a different angle from said first attaching surface 5a; and a housing 2 having an attaching surface 2c which is faciag to the second attaching surface 5b; the housing 2 and the lens 3 which has been adjusted the positional relation to the housing 2 are adhered and hfxed through the intermediate holding member 5.

Abstract: A coupling lens couples a beam emitted from a light source. A light deflector deflects the beam from the coupling lens at a uniform angular velocity. A line-image imaging optical system is disposed between the coupling lens and light deflector, and causes the beam to image a line image long along main scanning directions on or in the vicinity of a deflection reflective surface of the light deflector. A scanning and imaging optical system causes the beam deflected by the light deflector to image a beam spot on a medium to be scanned. In an optical housing, the light source, coupling lens, light deflector, line-image imaging optical system and scanning and imaging optical system are disposed, and contained. A plurality of holding and fixing datums are provided for holding and fixing a light-source part including the light source and coupling lens is provided in at least one of the light-source part and optical housing.

Abstract: A scanning image forming lens in an optical scanning apparatus for optically scanning a surface to be scanned at a constant velocity by deflecting a luminous flux formed as a linear image in a direction corresponding to a main scanning direction by an optical deflector having a deflecting reflective plane in the vicinity of the linear image so as to collect the deflected luminous flux on the surface to be scanned as a light spot with a scanning image forming lens, includes two lenses. The first lens provided at the optical deflector side is a positive meniscus lens with a concave surface facing toward the optical deflector side and has a co-axial aspherical shape at both sides.

Abstract: A real image type zoom finder optical system is constructed by an objective optical system, an erect orthoscopic optical system and an eyepiece optical system sequentially arranged from an object side. The objective optical system is composed of first to fourth lens groups each constructed by a single lens. The erect orthoscopic image optical system is composed of two erect prisms. The eyepiece optical system is composed of one lens group. A front face of the second lens group is constructed by an aspherical surface such that the first, second, third and fourth lens groups respectively have positive, negative, positive and positive refracting powers. A real image formed by the objective optical system is focused and formed within the erect orthoscopic image optical system. A zooming operation is performed by moving the second lens group from the object side to an eyepiece side on an optical axis of the finder optical system.

Abstract: A real image type zoom finder has a Porro prism for an erecting image arranged between an objective lens system and an eyepiece system, and a reflecting mirror or a movable prism constituting a portion of the Porro prism. The reflecting mirror or the movable prism is moved in a direction of an optical axis of the lens systems in accordance with distance information about a photographed object from a focal length detector, and/or information about the focal length of a zoom lens from a zoom focal length detector, thereby correcting parallax. The reflecting mirror may be composed of two overlapped mirrors constructed by a first mirror as a semi-transparent mirror arranged on the side of an objective lens and a second mirror composed of a total reflection mirror. In this case, the second mirror can be moved in the direction of the optical axis of the lens systems by a moving amount according to information about the focal length of the zoom lens.

Abstract: A finder of a real image type has an objective lens unit having positive refracting power; a first condenser lens unit arranged in the vicinity of a focal face of the objective lens unit on an image side thereof and having positive refracting power; a relay lens unit arranged on an image side of the first condenser lens and inverting an object image provided by the objective lens and the first condenser lens rightward and leftward, and upward and downward; a second condenser lens unit having positive refracting power and arranged in the vicinity of a focal face provided on an image side of the relay lens unit by a combination system of the objective lens unit, the first condenser lens unit and the relay lens unit; and an eyepiece unit arranged on an image side of the second condenser lens unit to observe an image formed by a combination system from the objective lens unit to the second condenser lens unit. The relay lens unit is constructed by one positive lens and two negative lenses. A focal length f.sub.