Abstract: An optical scanner comprises a light source for emitting a light beam, an optical deflector for deflecting the light beam and a scanning optical system for focusing the deflected light beam on a surface to be scanned. The scanning optical system has a diffracting section and a refracting section and may optionally have a reflector mirror or an optical filter. The illuminance distribution of the light beam is maintained to be substantially uniform on the surface to be scanned by offsetting the changes in the diffraction efficiency of the diffracting section, the transmittance of the refracting section, the reflectance of the reflector mirror and the transmittance of the optical mirror, due to the angle of view of the scanning optical system.

Abstract: An optical scanning apparatus includes a deflector for deflecting a beam emitted from a light source, and scanning optical system having at least one scanning lens for causing the beam deflected by the deflector means to be imaged on a surface to be scanned. At least one scanning lens constituting the scanning optical system has a plurality of positioning reference surfaces for effecting the positioning of the scanning lens in the direction of the optical axis thereof, and is disposed so that a straight line linking the points on two positioning reference surfaces together or a plane formed by the points on three or more positioning reference surfaces may be non-orthogonal to the optical axis. In a main scanning cross-section, the shape of the effective portion of the scanning lens is asymmetrical with respect to the optical axis.

Abstract: An optical scanning apparatus which is improved in color registration by reducing bow of a scan line which is formed on a photosensitive medium. A plate having a slit with a width appropriate for a spot size of a scan line and a length corresponding to a predetermined scanning length is interposed between the photosensitive medium and a spot forming apparatus. A light source emits a laser beam, a rotary polygonal mirror reflects light from the light source while being rotated, f-&thgr; lenses cause the light reflected from the rotary polygonal mirror to form a proper spot, and a reflecting mirror disposed on an optical path between the f-&thgr; lenses and the photosensitive medium directs the spot toward the photosensitive medium. The slit plate passes a portion of the spot to uniformly form the scan line.

Abstract: A bearing device is structured to include a stator portion which includes one of a shaft and a sleeve, a rotor portion which includes the other of the shaft and the sleeve which are structured to be capable of relative rotation therebetween, a first permanent magnet mounted on the rotor portion, and a second permanent magnet mounted at a position opposed to the first permanent magnet. The rotor portion is floated up relative to the stator portion by a magnetic force working between the first permanent magnet and the second permanent magnet. The first permanent magnet is mounted on the upper end portion of the rotor portion, the second permanent magnet is mounted on the upper end portion of the stator portion, and the first permanent magnet and the second permanent magnet are provided in opposed relationship with each other in a circumferential direction perpendicular to an axial direction of the bearing device.

Abstract: An optical scanning device deflects one or a plurality of light flux(es) originating from a light source by an optical deflecting unit, gathers the deflected light flux(es) to cause it(them) to form a beam spot(s) on a surface to be scanned by a scanning and image-forming optical system, and, thus, performs optical scanning of the surface to be scanned. The scanning and image-forming optical system includes one or a plurality of optical component(s) including a lens. At least one surface of the lens included in the scanning and image-forming optical system is a sub-non-arc surface having an arc or non-arc shape in a main scanning plane, and a non-arc shape in a sub-scanning plane. The sub-non-arc surface is formed in a lens in which a diameter of a light flux passing through the scanning and image-forming optical system is largest in the sub-scanning plane’.

Abstract: A scanning optical device to be used for an image forming apparatus such as a laser beam printer or a digital copying machine comprises a light source, an optical deflector, a first optical system for leading the light beam emitted from the light source to the optical deflector, and a second optical system for focussing the deflected light beam on a surface to be scanned, typically a photosensitive drum surface. The second optical system has a diffraction optical element and forms a light spot on the surface by selectively using the light beam of a predetermined order of diffraction. The sum of the light quantities of the light beams of the orders of diffraction on the positive side, relative to the predetermined order of diffraction, is smaller than that of the light beams of the orders of diffraction on the negative side, for the diffracted light beams located remotest from the optical axis or any of the light beams located within the scope of scanning.

Abstract: An optical scanning apparatus includes a light source for outputting light, a first lens system arranged to receive the light output from the light source and to transmit a light flux therefrom, an optical deflector arranged to receive the light flux from the first lens system and having a deflecting reflective plane to deflect the light flux from a surface therefrom and a second lens system arranged to receive the light flux deflected from the optical deflector and to condense the deflected luminous flux into an optical beam spot on a surface to be scanned so as to form images having image heights, the luminous flux condensed by the second lens system into the optical beam spot including an optical beam waist.

Abstract: A scanning and image forming lens system in an optical scanning apparatus optical scans a surface to be scanned by deflecting a luminous flux emitted from a light source in a direction corresponding to a main scanning direction via an optical deflector at equiangular velocity. The scanning image forming lens system transmits the luminous flux deflected by the optical deflector so as to condense the luminous flux into an optical beam spot on the surface to be scanned and to scan the surface to be scanned with the optical beam spot. The scanning image forming lens system includes one or more image forming optical elements including at least one lens. At least one lens surface of the at least one lens of the scanning image forming lens system has a non-arc shape in a sub scanning cross section.

Abstract: A scanning and image forming lens system in an optical scanning apparatus optical scans a surface to be scanned by deflecting a luminous flux emitted from a light source in a direction corresponding to a main scanning direction via an optical deflector at equiangular velocity. The scanning image forming lens system transmits the luminous flux deflected by the optical deflector so as to condense the luminous flux into an optical beam spot on the surface to be scanned and to scan the surface to be scanned with the optical beam spot. The scanning image forming lens system includes one or more image forming optical elements including at least one lens. At least one lens surface of the at least one lens of the scanning image forming lens system has a non-arc shape in a sub scanning cross section.

Abstract: A light scanning apparatus comprising: beam emitting means for emitting a light beam; a multi-facet rotary mirror having a plurality of reflective facets for reflecting the light beam emitted from the beam emitting means and rotatable for scanning the light beam reflected on the reflective facets over a scanning object; an incident optical system for shaping the light beam emitted from the beam emitting means to allow the light beam to have a greater width than a width of each of the reflective facets of the multi-facet rotary mirror as measured in a scanning direction for overfilled facet illumination and directing the light beam to the multi-facet rotary mirror; and an f&thgr; lens provided in a path of the light beam extending from the multi-facet rotary mirror to the scanning object; wherein the incident optical system comprises deflection means provided between the f&thgr; lens and the scanning object for deflecting the light beam emitted from the beam emitting means toward the multi-facet rotary mirror

Abstract: An optical scanning apparatus includes a light source for outputting light, a first lens system arranged to receive the light output from the light source and to transmit a light flux therefrom, an optical deflector arranged to receive the light flux from the first lens system and having a deflecting reflective plane to deflect the light flux from a surface therefrom and a second lens system arranged to receive the light flux deflected from the optical deflector and to condense the deflected luminous flux into an optical beam spot on a surface to be scanned so as to form images having image heights, the luminous flux condensed by the second lens system into the optical beam spot including an optical beam waist.

Abstract: A light scanner in which, when forming an image on a scan surface by a scanning optical device through a deflector using light from a light source device, the scanning optical device includes first and second f&thgr; lenses. The first f&thgr; lens is a meniscus positive lens whose concave surface faces the deflector within a main scanning cross-sectional plane. The second f&thgr; lens is a meniscus lens whose convex surface faces the deflector within the main scanning cross-sectional plane. The shape of the second f&thgr; lens is such that the curvature from the optical axis thereof to both ends of a lens effective portion changes from convex to concave. The second f&thgr; lens is such that it is disposed closer to the deflector at both ends of the lens effective portion than at an apex thereof on the optical axis of the second f&thgr; lens.

Abstract: An optical scanning lens used in a scanning and imaging optical system in which a beam deflected by a light deflector is condensed on or in the vicinity of a surface to be scanned. The optical scanning lens is formed through plastic mold, and a distribution of the refractive indexes &Dgr;n(x) inside of the optical scanning lens has a local maximum within a range through which the beam passes through the lens.

Abstract: A color laser printer includes a photoconductor section having photoconductive material configured to be exposed to receive a plurality of color toners in a selective manner representative of a color image to be printed. The printer further includes a scanning section having a plurality of lasers, preferably four lasers, each of the lasers being configured to generate pulsed beams of laser energy to be directed to the photoconductor section to selectively expose the photoconductive material. The scanning section also includes a single, rotating, polygonal-sided mirror having at least four reflective facets corresponding to selected sides of the polygon. The polygonal-sided mirror is positioned relative to the lasers and the photoconductor section such that the pulsed beams of laser energy from each of the lasers are reflected by the reflective facets of the polygonal-sided mirror to a predetermined lineal position on the photoconductive material.

Abstract: An optical scanning apparatus has an incident optical system for causing a light beam from a light source to be obliquely incident in a sub-scanning cross-section on a deflecting surface of an optical deflector, and an imaging optical system for forming, on a scanned surface, an image of the light beam deflected by the deflecting surface.

Abstract: A scanning and image forming lens system in an optical scanning apparatus optical scans a surface to be scanned by deflecting a luminous flux emitted from a light source in a direction corresponding to a main scanning direction via an optical deflector at equiangular velocity. The scanning image forming lens system transmits the luminous flux deflected by the optical deflector so as to condense the luminous flux into an optical beam spot on the surface to be scanned and to scan the surface to be scanned with the optical beam spot. The scanning image forming lens system includes one or more image forming optical elements including at least one lens. At least one lens surface of the at least one lens of the scanning image forming lens system has a non-arc shape in a sub scanning cross section.

Abstract: Two shorter focal length wobble correction optical elements reduce the height of a raster output scanning (ROS) system. The wobble correction optical elements can be two lenses or two mirrors.

Abstract: Scan line bow correction for raster output scanners, and systems that use raster output scanners. Scan line bow correction is performed in raster output scanners having a post-polygon optical system that includes an f-&thgr; lens system that has at least two multiple scan lenses by controllably tilting a second scan lens along the fast-scan axis. Beneficially, the tiltable scan lens is mounted on a mounting pad that includes a threaded hole. A threaded set screw screws into the threaded hole to provide an adjustable support. In practice the threaded hole-set screw should have a high number of threads per millimeter to provide fine bow correction adjustment.

Abstract: Even if light beams are caused to obliquely become incident on a light deflector, an optical scanner will be constructed of one F&thgr; lens without bending the center line of the lens. The optical scanner has a deflection part on which light beams are incident from a light source to incline their optical axes by a predetermined angle in a slow scan direction, and a scanning optical system for scanning an optical spot at a substantially constant velocity, and focusing incident light beams on a surface to be scanned. The scanning optical system is preferably constructed of a single lens, both sides of which are aspherical, this lens is caused to refract, on a first refractive surface, to reduce a change in an incident angle of the light beams in the slow scan direction, which change in response to an deflection angle, and is caused to refract, on a second refractive surface, such that the light beams after emission are emitted in a substantially coincided orientation in the slow scan direction.

Abstract: According to one aspect of the present invention a method for increasing intensity of a polarized multimode laser beam including the steps of: (i) changing polarization of a portion of a cross section of the multimode laser beam, so that the cross section of this multimode laser beam comprises a first portion with one polarization and a second portion with a polarization that is different from this one polarization; and (ii) at least partially superimposing the first portion of the cross section of the multimode laser beam onto the second portion of the cross section of the multimode laser beam, thereby forming a superimposed laser beam.

Abstract: A laser marking method and an apparatus thereof which realize stamp processing with a beautiful appearance and a high precision, without reducing the manufacturing efficiency. The laser marking method comprises a step of sequentially displaying divisional patterns each corresponding to one scanning line of a first deflector, a step of sequentially scanning the divisional patterns with a laser beam from a laser oscillator by the first deflector, and a step of moving a stamp position on a work surface for every one of scanning transmission beams respectively transmitted through the divisional patterns, in a direction perpendicular to a scanning direction, by a second deflector, thereby to synthesize and stamp the divisional patterns.

Abstract: A scanning optical system includes a light source, an optical deflector for deflecting a laser beam emitted from the light source, a first optical element for collimating the laser beam emitted from the light source into a parallel beam, a second optical element for focusing the parallel beam collimated by the first optical element to the optical deflector and making the parallel beam incident on the optical deflector, a third optical element for focusing the laser beam deflected by a deflection plane of the optical deflector onto a target irradiation surface. In a subscanning section of the scanning optical system, the following conditions are satisfied. An optical axis of the first optical element and an optical axis of the second optical element are parallelly decentered from each other. The second optical element and the third optical element are decentered from a central axis of the scanning optical system.

Abstract: A method and apparatus for printing images. The optical output from a spatial multimode laser, which is multimode in one direction and is single mode in the orthogonal direction, is scanned parallel to the multimode direction. More specifically, according to one aspect of the present invention the printing apparatus includes a multimode laser having an emitting aperture that provides a laser beam. A scanner scans the laser beam from this laser along a scan line such that a long dimension of said emitting aperture corresponds to the scan direction. An optical system focuses the laser beam to a spot having a long dimension and a short dimension, such that the long dimension of the spot is along the scan direction.

Abstract: An aperture and a field lens are positioned between the collimator and the rotating polygon mirror of a multiple reflection, multiple beam raster output scanner to eliminate differential scan line bow. The aperture and the field lens will be positioned where the multiple beams cross the optical axis of the raster output scanner optical system. The multiple beams are telecentric.

Abstract: A technique for marking pixels on workpieces by routing a scanned beam to different marking stations to mark individual pixels on the workpieces. A diffractive scan lens focuses the beam. A mark is formed on a workpiece by producing the mark and curing the mark. Angular position of a scanning mirror in a raster scanner is determined by moving a beam, reflected from the scanner, across rulings on an optical element during scanning. A print head for printing spots on a surface of a workpiece has a walled, internally pressurized chamber and structure for causing an inked web to conform to a contour of the chamber wall and to be pulled along the chamber wall. A print head has a compliant-walled, internally pressurized chamber. A print head has a chamber having a low-coefficient of friction coating. Two workpieces may be marked at two marking stations by two-directional scanning.

Abstract: Disclosed is a laser print head, suitable for use with a recording medium, comprising a print head base comprising a plurality of mounting surfaces, one or more optical radiation source removably affixed to a first base mounting surface, at least one collimating lens, at least one focusing lens affixed to a second base mounting surface, a pre-objective lens affixed to a third base mounting surface; an objective lens, and one or more optional mirror facets.

Abstract: A fast scan error measuring system of a raster output scanner (ROS) is provided in order to determine whether the laser beam position in the fast scan direction is within acceptable operational parameters. A detector, for example, a linescan or area array camera, is used to acquire multiple successive images from each facet of the ROS as the unit is operating. For each rotating facet the position of a beam spot (centroid) at the end of scan line is measured. A sufficient number of centroids are collected so that a Fourier transform of the centroids will produce an accurate spatial frequency spectrum measured in cycles per millimeter. This spectrum can be easily compared to the product's fast scan error specification limits.

Abstract: An optical element and a scanning optical apparatus using the same capable of correcting for image plane re-positioning caused by internal distortion of the optical element, particularly, refractive index distribution caused by forming the optical element by plastic molding. The optical element has an internal refractive index distribution such that the focal length calculated based on the curvature of the plane thereof, the refractive index of the material, and the thickness along the optical axis, is shorter than the focal length actually measured. The element may be used in the scanning optical apparatus, may be provided with planes of different curvatures in a generating line and a line perpendicular thereto, and may be longer in the generating line.

Abstract: A scanning optical system includes a light source, an optical deflector for deflecting a laser beam emitted from the light source, a first optical element for collimating the laser beam emitted from the light source into a parallel beam, a second optical element for focusing the parallel beam collimated by the first optical element to the optical deflector and making the parallel beam incident on the optical deflector, a third optical element for focusing the laser beam deflected by a deflection plane of the optical deflector onto a target irradiation surface. In a subscanning section of the scanning optical system, the following conditions are satisfied. An optical axis of the first optical element and an optical axis of the second optical element are parallelly decentered from each other. The second optical element and the third optical element are decentered from a central axis of the scanning optical system.

Abstract: An optical recording and data processing system for exposing an image on to a flexible, light sensitive medium, which includes a medium holder having an inner cylindrical wall portion against which is held said medium, and a light source having an approximately rectangular emitting aperture, with a short aperture axis and a long aperture axis, operative to emit a beam of light having a rectangular cross section with a long axis corresponding to the long aperture axis and a short axis corresponding to the short aperture axis. An optical modulator is aligned with the light source so as to intercept light from the beam of light and produce a spatial modulation pattern across the long axis of the beam of light. A pattern shifter for shifting the spatial modulation pattern across the length of the long axis at a constant rate is provided as is a pattern rotator for rotating the spatial modulation pattern at a rate equal to the rate of shifting of the spatial modulation pattern.

Abstract: An optical scanner assembly for exposing an image on a piece of photosensitive film positioned within an internal drum type exposure assembly. The optical scanner assembly is part of a laser imaging system suitable for use in a medical imaging system. The optical scanner assembly includes a laser mechanism for producing a laser beam representative of the image to be exposed on the photosensitive film. A first lens system is provided for shaping and focusing the laser beam in a first direction, including a long, flexible cylinder lens. A second lens system is provided for shaping and focusing the laser beam in a second direction, including a second cylinder lens oriented generally perpendicular to the long, flexible cylinder lens.

Abstract: A beam passing position controlling apparatus comprises a light source for emitting a beam, a mechanism for reflecting the beam toward an image carrier surface to scan the image carrier surface, a sensor for detecting a position where the beam passes on the image carrier surface, a circuit for calculating a correction amount from the position detected, a mechanism for correcting the passing position of the beam on the basis of the correction amount, and a circuit for controlling respective operations of the apparatus.

Abstract: A scanning optical apparatus includes a light source unit, a deflector for deflectively scanning a light beam from the light source unit, an optical box in which the deflector is accommodated and an optical system for focusing the light beam deflectively scanned by the deflector on a predetermined surface. The optical system is supported by the optical box and having upside-down prevention mechanism which interferes with a predetermined portion of the optical box to prevent upside-down mounting of the optical system.

Abstract: To provide an optical scanner for typical use with laser beam printers that is capable of effective correction of aberrational characteristics and which also produces a constant beam spot size, a semiconductor laser array 1 having a plurality of light-emitting portions issues a plurality of beams, which are reflected and deflected by reflecting surfaces of rotating polygonal mirror 5 and pass through imaging lens 6 to form a plurality of beam spots on the surface to be scanned 7. Both the entrance and exit surfaces of imaging lens 6 are such that the curvatures in the sub- and main scanning directions are independent of each other, with the curvature in the sub-scanning direction varying continuously in the main scanning direction over the effective area of imaging lens 6.

Abstract: By adding an acousto-optic deflector to an existing design of laser marker the laser marker's throughput is increased by a large factor, typically a factor of 5. Galvanometer driven mirrors, which in existing laser markers are used to trace out the strokes in characters are, in this invention, used only to scan smoothly along lines of characters. The acousto-optic deflector, being much faster than the galvanometers, is used to trace out the individual strokes in the characters. Marking rates of 1000 characters per second are achieved in the case of characters for which capital letters are 2 millimeters high and a 2 millimeter long stroke contains 13 laser-produced craters. This performance is achieved over fields as large as 300 millimeters square. The quality of marked characters is improved because the deleterious effects of mirror inertia on character quality, commonly seen when a laser marker is pushed for speed, are eliminated.

Abstract: A dynamic-pressure gas bearing structure includes a sleeve, a column-like shaft fitted to the sleeve, and a plurality of shallow grooves formed on the outer peripheral surface of the shaft and extending in the axial direction of the shaft. The shallow grooves are formed by grinding in which grains are aligned to the aforementioned axial direction. An optical deflection scanning apparatus is provided with such dynamic-pressure gas bearing structure.

Abstract: A laser beam printer of the present invention has a laser exposing unit including apochromatical plastic cylinder lenses being integrally formed by adhesion of plastic of the same material as a f.theta. lens or molding, having negative power in a sub-scanning direction, a substantially flat surface contacting air, and first and second f.theta. lenses in which surfaces other than a toric surface are displaced in the same direction in the sub-scanning direction and a toric surface is displaced in the direction opposite to the other surfaces in the sub-scanning direction and a different inclination is provided for each of the lenses. The plastic cylinder lens and the glass cylinder lens may be inversely arranged.

Abstract: An optical scanning system in which light emitted from a light source is deflected by a deflector and converged onto a surface to be scanned by an optical image forming system. The optical image forming system has a curvature of field in a sub-scanning direction to cancel a change in a beam spot diameter caused by a change in an F-number in the sub-scanning direction, depending on an image height in the main scanning direction. The invention is also addressed to a method for determining a curvature of field in the optical scanning system.

Abstract: An apparatus and method for controlling the modulation of an exposing beam of a rotating polygon type image forming apparatus using control marks formed on a rotating surface portion of a polygon member or a motor polygon assembly. The control marks are read by a reader during rotation of the polygon member, and the information read from the control marks is used to control the modulation of the exposing beam of the image forming apparatus to expose evenly spaced, uniformly sized, precisely oriented, geometrically straight scan lines of pixels on a photosensitive member. The control marks can include pixel clock information, intensity correction information, error correction information about individual facets of the polygon member, and motor speed control information.

Abstract: An optical scanning apparatus has a light source, a first optical system for converting luminous flux emitted from the light source to converged luminous flux, a deflector for deflecting the converged luminous flux emitted from the first optical system, and a second optical system for forming an image in a spot shape on the plane to be scanned from luminous flux deflected by the deflector. The second optical system comprises a single lens. Parameters R.sub.1, R.sub.2, Y.sub.max, S.sub.1, S.sub.2, and d of the single lens satisfy the following expressions, with R.sub.1 denoting the paraxial curvature radius of the lens surface facing the deflector in the single lens, R.sub.2 denoting the paraxial curvature radius of the lens surface facing the plane to be scanned in the single lens, Y.sub.max denoting the maximum effective diameter on the main scanning plane of the single lens, S.sub.

Abstract: The present invention provides an optical exposer unit having a large space for containing black toner, and a color image forming apparatus comprising the optical exposer unit. In an optical exposer unit, first and second laser beams, which are reflected on the respective reflection surfaces of a polygonal mirror unit and passed in a direction farther from a photosensitive drum than an optical axis of an optical system including first to third image-forming lenses, are reflected on second mirrors, and mutually crossed each other so as to be guided to the photosensitive drum corresponding to third mirrors. Thereby, a sufficient space is provided to the surroundings of a black image forming section. Therefore, the space for containing black toner can be largely ensured as compared with the space for containing the other color toner.

Abstract: A multi-beam optical system includes: a light beam generating part for generating a plurality of light beams using a plurality of light-emitting parts which are offset from each other in the sub-scanning direction and which are individually controllable; a coupling optical part for transmitting said plurality of light beams generated by said light beam generating part; an aperture part for defining said plurality of light beams, respectively; a beam combiner part for combining said plurality of light beams; a first image forming part for forming images of said plurality of light beams passing through said coupling optical part; a deflector part for deflecting said plurality of light beams output from said first image forming part, the images of said plurality of light beams being formed in a vicinity of said deflector part; and a second image forming part for forming images of said plurality of light beams deflected by said deflector part, wherein an exit pupil is in a conjugated arrangement with said second

Abstract: In an optical scanner, a deflected light beam is reflected on a reflective image forming element and is converged as a light spot on a scanned face through an elongated lens to perform an optical scanning operation at an equal speed. The reflective image forming element has a reflecting face with rotation symmetry and converges a reflected light beam onto the scanned face in a main scan-corresponding direction. The elongated lens has a barrel type toroidal face as an incident face and has a normal toroidal face as a light emitting face. The elongated lens sets the scanned face and the forming position of a linear image to a substantially conjugate relation in a cross scan-corresponding direction in cooperation with the reflective image forming element. A conjugate magnification m.sub.0 in the conjugate relation of the reflective image forming element and the elongated lens with respect to an image height 0 of the light spot satisfies the following condition:1>m.sub.0 >0.35.

Abstract: The present invention is to provide image forming apparatus comprising an optical exposer unit capable of forming a color image having no color shift. The optical exposer unit includes a plurality of mirrors reflecting laser beams reflected by a reflector and passed through first to third image-form lenses in predetermined order. At least one of the respective laser beams reflected by each of the respective mirrors toward a photosensitive drum is guided to the photosensitive drum through a transparent plate provided to form an angle of 90.degree.-0.3.degree. and/or 90.degree.+0.3.degree. with each of the laser beams.

Abstract: An optical scanning apparatus which includes a housing, an optical source which emits an optical beam, a deflector which deflects an optical beam from the optical source, a focusing lens which focuses the optical beam from the deflector, and plural mirrors which reflect the optical beam from the deflector. The plural mirrors include a first mirror which reflects the optical beam from the deflector, a third mirror which reflects the optical beam from the first mirror, and a second mirror which reflects the optical beam from the third mirror. The optical beam is focused upon a photoconductive element by the focusing lens through the plural mirrors on a scanning surface, and at least one of the first mirror and the third mirror is pivotally supported to be adjusted in a sub-scanning direction. Further, the second mirror is slidably supported to be adjusted in a direction normal to a reflecting surface of the second mirror.

Abstract: An optical scanning device having a scanning speed which can be used in a laser beam printer, a digital copier, a facsimile apparatus or the like, an optical scanning method using the optical scanning device, and an image forming apparatus using the optical scanning device are disclosed. The optical scanning device comprising: a light source for emitting a laser beam having a constant divergent angle; a thin film waveguide; means for coupling the laser beam to said thin film waveguide; and a comb-like electrode for exciting a surface acoustic wave of a high frequency sweep signal so that the laser beam is deflected to be output as parallel rays.

Abstract: An optical scanner for use in laser beam printers and the like which is particularly satisfactory in imaging characteristics. A light beam from a semiconductor laser passes through a collimator lens, an aperture diaphragm and a cylindrical lens. The beam is then deflected by a rotating lens mirror and subjected to the focusing action of an imaging lens so that it is focused to form a beam spot, which scans over a scan surface as the beam is deflected. The imaging lens has aspheric surfaces in the main-scanning cross section and is designed so that the rate of change in its curvature and other relevant parameters satisfy a predetermined equation so as to lie within a predetermined range.

Abstract: The improved beam scanning apparatus has an optical element that is driven to rotate by means of a drive means so as to be capable of continuous angular displacement with respect to the beam from a light source. The optical element deflects the incident beam so that it is focused to form image on the image plane. It is provided with an entrance face, a reflecting face and an exit face which have their shape specified in such a way as to achieve effective correction of aberration, provide higher resolution, and reduce the size and cost of the apparatus.

Abstract: An optical scanning apparatus has an F-.theta. function with one aspherical lens having a toric configuration that compensates for the vibration of a rotating polygon mirror. The optical scanning apparatus includes a laser diode as the source of light, a collimator lens, a compound prism, a rotating polygon mirror, and a scanning lens system. The compound prism is located between the rotating polygon mirror and the laser diode so that the laser diode and an optical axis form a right angle. The scanning lens is composed of one lens with magnification in mainscanning/subscanning directions. With such a construction, by providing an F-.theta. function and compensating for the vigration of the rotating polygon mirror, the number of lenses is mnimized, the manufacture and assembly/adjustment of the lens are simplified, and the number of manufacturing steps can be reduced.

Abstract: Fluorescent reference tracks for use in correcting for geometric and other distortions in an image scanning system comprising a rotatable cylindrical drum assembly and an optical subsystem disposed within a protective housing is disclosed. Fluorescent reference tracks illuminable by light outside the visible spectrum, such as ultraviolet (UV) light, are disposed on inner surfaces of inwardly directed film support shoulders of the drum assembly. Respective edges of film containing an image to be scanned are retained on the outer surfaces of the film support shoulders of the drum assembly. As the film is rotated by the drum assembly past a primary light source disposed adjacent one side of the drum, light from the primary light source is directed through the film and is focused by a lens assembly disposed internal to the drum assembly onto a sensor assembly disposed at an opposite side of the drum assembly, which scans the transilluminated film portion.