Abstract: An aperture shapes a beam from a light source, a light deflector deflects the beam, and a scanning imaging optical system condenses the deflected beam toward a surface to be scanned so as to form a beam spot on the surface to be scanned. A wavelength &lgr; of the beam emitted by the light source satisfies: 350 (nm)≦&lgr;≦600 (nm), and, a desired diameter &phgr; of the beam spot and the wavelength &lgr; satisfy: 0.5 (mm)≦&phgr;2/&lgr;≦6 (mm).

Abstract: A multi-beam scanning device includes a plurality of light sources which emit multiple beams. A plurality of coupling lenses couple the multiple beams from the light sources. A converging lens device converts the coupled beams into converging beams, the converging beams being elongated in a direction corresponding to a main scanning direction and converging only in a direction corresponding to a sub-scanning direction, at least two of the converging beams forming a difference angle therebetween. A rotary deflector has a reflection surface rotated about a fixed rotation axis. The reflection surface deflects the converging beams while the reflection surface is rotated. A scanning lens device scans an image surface in the main scanning direction at a substantially uniform velocity by focusing each deflected beam into a beam spot on the image surface.

Abstract: A multi-beam scanning apparatus performs image scanning by emitting multiple beams from a plurality of light sources, which beams are deflected by a common deflector at equiangular velocity. The beams are then condensed by a common scanning image forming lens so as to form optical spots on a scanning surface. As a result, the plurality of lines are simultaneously scanned by the beams on the scanning surface at a substantially constant velocity. Characteristics of the light sources, such as the wavelength thereof, and other factors such as writing density and desired writing width of a writing line, are arranged to eliminate differences in a written vertical line in a sub scanning direction caused by a magnification difference, regardless of the cause of such differences. In addition, the modulation frequency of the plurality of light sources is made different from each other so that writing widths of the dots written by the plurality of light sources become the same.

Abstract: A zoom lens of high magnification has first, second and third zoom groups which are sequentially arranged from an object side toward an image side and respectively have a positive focal length, a positive focal length and a negative focal length. The entire first to third zoom groups are moved onto the object side by zooming from a wide angle end for arranging the first and second zoom groups in proximity to each other to a telescopic end for arranging the second and third zoom groups in proximity to each other while a distance between the second and third zoom groups is reduced. The zoom lens is constructed by six lens groups composed of six lenses in which each of the zoom groups is constructed by one positive lens and one negative lens. A focal length f.sub.1 of the first zoom group, a combined focal length f.sub.T of the entire lens system at the telescopic end, a focal length f.sub.2 of the second zoom group and a combined focal length f.sub.

Abstract: A wide-angle lens system includes a first, second, third and fourth lens components which are arranged in this order in a direction from an object side to an image surface side along an optical axis. A stop is provided between the second lens component and the third lens component. The first lens component comprises a double-concave lens, the first lens component having a first refracting power .phi.1 which is negative. The second lens component comprises a positive lens and a negative lens which are arranged in this order in the direction, the second lens component having a second refracting power .phi.2 which is positive. The third lens component comprises a negative lens, a positive lens and a negative lens which are arranged in this order in the direction, the third lens component having a third refracting power .phi.3 which is positive. The fourth lens component comprises a negative lens, the fourth lens component having a fourth refracting power .phi.4 which is negative.

Abstract: A first zoom lens group, a second zoom lens group, a third zoom lens group and a fourth zoom lens group are arranged on an optical axis in that order from an object side. The first zoom lens group has a negative lens and a positive lens arranged in that order from the object side, the first zoom lens group as a whole acting as a zoom lens group having a positive focal length. The second zoom lens group has a negative lens and a positive lens arranged from the object side in that order, the second zoom lens group as a whole acting as a zoom lens group having a negative focal length. The third zoom lens group has a double concave lens and a double convex lens arranged in that order from the object side, the third zoom lens group as a whole acting as a zoom lens group having a positive focal length, the third zoom lens group being provided with a diaphragm.

Abstract: A developer recycling system is provided for replenishing a fresh developer to a developing device of an image forming apparatus and collecting it after use. A developer cartridge applicable to the system is also provided. When the fresh developer is replenished from the cartridge to the developing device, a developer existing in the developing device overflows in an amount corresponding to the replenished developer. The developer overflown the developing device is recirculated to the cartridge and reused.

Abstract: A hybridoma producing a monoclonal antibody specific for free N-acetylneuraminic acid or beta glycoconjugates thereof, is herein disclosed. The hybridoma can be generated by fusing (i) B cells of lymphocytes obtained by immunizing an animal with an N-acetylneuraminic acid or a beta-glycoconjugate thereof, and (ii) myeloma cells.

Abstract: This invention relates to a wide angle lens system having small telephoto ratio. The strong curvature of a negative lens group arranged on the image side, which is the characteristic of the lens system of this type, is eased by composing the negative lens group as a doublet. This structure maintains the spacing between the front lens group and the rear lens group to be small.The negative lens group on the image side comprises two negative meniscus lenses, which have surfaces having stronger curvature facing each other.

Abstract: Provided is a zoom lens including four lens groups having refracting powers of negative, positive, negative and positive, respectively, arranged in the mentioned order from the objective side of the zoom lens, wherein, upon zooming from a short forcal length to a long forcal length, a first lens group moves at first toward the image side and then is reversed to move toward the objective side, while second, third and fourth lens groups all monotonously move toward the objective side.

Abstract: This invention relates to a macro-focus zoom lens in which five lens groups of a refractive power arrangement of negative, positive, negative, positive and positive are allowed to have a macro-focusing function. As zooming performs from a tele to a wide angle, a second lens group and a fourth lens group is moved as a variator towards an image, a first lens group is moved as a compensater, and a third lens group and a fifth lens group are fixed. When the second group and fourth group are moved from the wide angle end to the object side, macro-focusing becomes possible to make. This involves less variation in aberration as compared with macro-focusing by other methods and a lens mount is also simple in construction.

Abstract: A wide angle zoom lens contains, in order from an object side, a first group having a negative focal length, a second group having a positive focal length and a third group having a negative focal length as well as a fourth and a fifth group each of which have a positive focal length. When the lens is moved to effect zooming from the side having a short focal length to a side having a long focal length either the first group is first moved toward the final image plane on an optical axis in a first movement phase and then moved toward the object in a second phase of movement or the first group is moved toward the image with each of the movements being executed in a non-linear fashion to correct variation of a focal length.

Abstract: A telephoto zoom lens comprises a first, a second, a third and a fourth group which are sequentially disposed beginning from an object side. The first group is a focusing lens group and remains stationary during a zooming operation, but is movable during a focusing operation and as a whole has a positive refractive power. The second group is a variator lens group and generally has a negative refractive power. The second group moves along the optical axis during a zooming operation, and is principally used for converting the focal length. The third group is a compensator lens group which generally has a positive refractive power and which moves along the optical axis during a zooming operation to maintain an image plane at a given location as it varies with a movement of the second group. The fourth group is a relay lens system which remains stationary during a focusing or a zooming operation.

Abstract: An anamorphic f.theta. lens system, with respect to a sweeping surface, has a pupil position positioned to coincide with a reflective surface of a rotating polyhedric mirror. Parallel incident light at an angle .theta. with respect to an optical axis is converges on a scanning surface at a position separated from the optical axis by a distance proportional to .theta.. In the divergent direction of the reflected light from the reflection surface, there is a conjugate relationship between the reflection surface and the scanning surface, where the reflection surface is an object surface, and the scanning surface is an image surface.

Abstract: A bar lens array is mounted between an original document and a photoconductive member in such a manner that the ends of the bar lenses are equally spaced from the document and photoconductive member regardless of manufacturing differences in the length of the bar lenses of the array. Reference marks may be provided at the center of the bar lens array and at a point halfway between the document and photoconductive member which are aligned with each other. The bar lens array may be mounted in a sleeve which compensates for the length of the bar lenses. In this embodiment, a stopper is provided at a fixed distance from one of the document or photoconductive member. The distance C from one end of the bar lens array to a point on the sleeve adapted to align with the stopper is C=(D-L)/2-K where D is the distance between the document and the photoconductive member, L is the length of the bar lens array and K is the distance from the stopper to the one of the document or photoconductive member.

Abstract: A microfiche on which a large number of characters are formed in an alternating arrangement is movable behind a mask in such a manner that at each position of the microfiche relative to the mask a desired group of characters is displayed through respective apertures in the mask. Lenses are disposed behind the apertures to project images of the characters therethrough onto a viewing screen. A reflection support member is disposed behind the microfiche and is formed with a stepped surface on which are disposed a plurality of concave reflectors, one reflector behind each lens. A lamp radiates light onto the reflectors, from which the light is reflected and focussed into the respective lenses, thereby illuminating the characters on the microfiche from behind. The radii of curvature and light receiving frontal areas of the reflectors differ in accordance with the distances of the reflectors from the lamp and the respective lenses.

Abstract: A rectangular array of rod lenses is arranged between an original document and a photoconductive member, and the document and photoconductive member move relative to the rod lens array at the same speed. The document is illuminated for three sequential color separation exposures so that three color images are formed on the surface of the photoconductive member by the rod lens array. Due to the construction of the means for illuminating the document, the brightness of the illumination is different for the three color separation exposures. This is compensated for by varying the number of rod lenses for the three color separation exposures and thereby the cross sectional area of the rod lens array which constitutes an exposure aperture so that the effective brightness of illumination is the same for the three color separation exposures.

Abstract: A bar lens array is mounted between an original document and a photoconductive member in such a manner that the ends of the bar lenses are equally spaced from the document and photoconductive member regardless of manufacturing differences in the length of the bar lenses of the array. Reference marks may be provided at the center of the bar lens array and at a point halfway between the document and photoconductive member which are aligned with each other. The bar lens array may be mounted in a sleeve which compensates for the length of the bar lenses. In this embodiment, a stopper is provided at a fixed distance from one of the document or photoconductive member. The distance C from one end of the bar lens array to a point on the sleeve adapted to align with the stopper is C = (D-L)/2 - K where D is the distance between the document and the photoconductive member, L is the length of the bar lens array and K is the distance from the stopper to the one of the document or photoconductive member.

Abstract: A plastic casing in which bar lenses are imbedded is formed with longitudinal grooves in the sides thereof. The bifurcations of a bifurcated pull rod are guidingly slidable in the grooves. A frame is connected to the pull rod for movement therewith and has portions facing the end faces of the bar lenses to which is fixed a cleaning material such as cloth. Movement of the pull rod, frame and cleaning material results in the cleaning material moving over the faces of the bar lenses to clean the same.