Abstract: A multi-beam laser exposure unit of the present invention includes a light beam deflector for deflecting a light beam in a predetermined direction, a plurality of laser devices, a pre-optical system, including a glass lens and a plastic lens, for converting a cross sectional shape of a light beam emitted from the respective laser devices to a predetermined shape, and a post-deflection optical system, including two lenses for image-forming each light beam deflected by the deflector to be scanned on a predetermined image surface at a uniform speed. The power of the two lenses of the post-deflection optical system is defined to be positive in a direction parallel to a rotational axis of reflective surfaces of the deflector. Also, at least one lens surface of these lenses is formed not to include a rotational symmetrical surface.

Abstract: A device for adjusting the position of a deflecting mirror included in an image forming apparatus, particularly one including a plurality of photoconductive elements, is disclosed. The device includes eccentric cams rotatable to adjust the position of the deflecting mirror.

Abstract: An item of office equipment, such as a facsimile machines, is provided having image analysis and laser printing capabilities with a shared mechanical image scanning apparatus. Embodiments include a single assembly with an analysis head and a laser emitting source disposed facing each other, a revolving mirror interposed between them, and first and second returning mirrors disposed symmetrically with respect to a line along which the analyzing head and the laser emitting source are disposed, such that the revolving mirror is located substantially at a point constituting an operational centre of symmetry of the single assembly. This symmetrical design allows the single analysis/printing assembly to be structurally simple and compact, enables the number of photosensors and LEDs necessary for image analysis to be reduced to as few as one of each, and eliminates the need for analog shift registers, thus decreasing the cost, size and complexity of the device.

Abstract: A multi-beam scanning optical apparatus of the present invention which is a multi-beam scanning apparatus which forms an image on a scanned surface via a plurality of laser beams, the laser scanning device has, a light source emitting a plurality of laser beams, a modulation device capable of switching the respective modulation frequencies of the laser beams, a deflection device deflecting the laser beams, capable of switching the scanning cycle of the laser beams, an axially symmetric optical system changing the distance among the laser beams on the scanned surface relative to a direction perpendicular to both an optical axis of the laser beams and a scanning direction by inserting itself into the optical path of the laser beams and a moving device inserting said axially symmetric optical system into the optical path.

Abstract: A system and method of providing a periodic trajectory scan path for a laser beam across a photoconductive surface in a laser printer. A preferred embodiment of the periodic trajectory for a system with a two-axis deflector includes a multiple-frequency omega wave trajectory for providing a substantially rectangular grid of available dot locations for selective laser beam pulsing. As such, a plurality of generally linear rows of dots are completed in a single scan pass of the laser beam across the surface. The periodic trajectory is provided by deflecting the laser beam with an optical beam deflector, such as an electro-optic deflector, placed between the laser and the rotating polygon scanning mirror. A preferred embodiment of the beam deflector includes a folded optical path.

Abstract: A system and method of deflecting a laser beam in a laser printer for providing enhanced resolution and reduced banding effects. Specifically, to enhance resolution, the laser beam is borrowed (deflected) from a white space area adjacent an image to double resolution at the edges of the image. Similarly, banding is reduced by deflecting the beam to compensate for drum rotational and translational errors. The beam is deflected using an electro-optic modulator placed between the laser diode and the scanning mirror. Encoders detect drum rotational errors and motion between the optics unit and the drum to provide a closed loop feedback system for reducing banding.

Abstract: Disclosed is a scanning apparatus having a cascade scanning optical system.

Abstract: A laser drawing apparatus is provided that splits a laser light into a plurality of drawing beams aligned in a common plane. The aligned drawing beams are reflected and deflected through a deflecting mirror to scan a drawing surface. The beams reflected off the mirror are converged through a scanning optical system onto the drawing surface in such a manner that the height of the drawing beams on the drawing surface is in proportion to the deflection angle and a strict relationship exists between the various incident and reflecting angles as well as the focal length of the scanning optical system and pitch of the drawing beams.

Abstract: A laser beam scanning unit (53) adapted for scanning laser beams on a surface of a charged image bearing member (5) is provided. The laser beam scanning apparatus (53) comprises a semiconductor laser array (21) having a plurality of light emitting portions (21a) and a rotating polygon mirror (3) adapted for deflecting laser beams emitted from the light emitting portions to the image bearing member (5). The light emitting portions (21a) are disposed two-dimensionally on a surface of the semiconductor laser array. The lighting and the amount of light of the light emitting portions (21a) are discretely controlled by a control unit (60).

Abstract: A cascade scanning optical system which includes a plurality of laser scanning optical systems each emitting a laser beam to scan a surface of a member, and a beam splitter positioned in an optical path between the plurality of laser scanning optical systems and the member such that a first laser beam which has passed through the beam splitter and a second laser beam which has been reflected by the beam splitter proceed to the surface on a common line thereon in respective ranges of the common line. Each of the plurality of laser scanning optical systems is desinged as a telecentric system.

Abstract: An optical scanner includes an optical deflector having a plurality of reflecting surfaces to deflect laser beams emitted from light sources, an f .theta. lens to through which the laser beams pass for correcting fluctuation of laser beams caused by the plural uneven reflecting surfaces of the optical deflector, a first mirror provided at a first side to the optical axis of the f .theta. lens to reflect laser beams passed through the f .theta. lens, and a second mirror provided at a second side opposite to the first side to the optical axis of the f .theta. lens to reflect the laser beams reflected by the first mirror and lead the laser beams to photosensitive drums arranged at the second side. Further, the optical scanner includes a fixing member provided at the first side to hold the f .theta. lens and a presser blade spring provided at a position closer to the optical axis of the f .theta. lens than the second mirror at the second side to press the f .theta. lens against the fixing member.

Abstract: A two-beam detection method causes two beams to differ in light intensity and converging the two beams to enter a common photosensitive element, a photoreception surface of the photosensitive element being configured such that the two beams differ in time required to pass the photoreception surface, processes an output from the photosensitive element using a plurality of threshold levels so as to obtain rectangular signals, one of the rectangular signals obtained using one of the plurality of threshold levels being designated as a detection signal for one of the two beams, and performs a predetermined calculation on the rectangular signals so as to obtain a detection signal for the other of the two beams.

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

Abstract: A system for scanning or tracking, which includes a polygon rotatable about a rotational axis. The system further includes a fixed radiation source directing radiation at the polygon along a path whose extension would intersect the rotational axis of the polygon. The intersection of the extended path with the rotational axis of the polygon constitutes an original imaginary intersection point. The system includes a first scanned region onto which the radiation is projected, the projection being characterized in that radiation emanating from the radiation source is reflected from the polygon and is made to propagate, prior to impinging on the first scanned region, along a path which includes at least one additional path segment with the additional path segment passing through or directed at an additional intersection point, the additional intersection point being a real or imaginary image of the original intersection point.

Abstract: A scanner is here disclosed in which the structure of an f.theta. lens can be simplified to decrease the cost of the scanner and facilitate the installation operation. In order to maintain the f.theta. properties, it is necessary to carry out control by prolonging a time interval of the radiation of light beams in the vicinity of the center of main scanning, and by shortening the time interval in the vicinity of the end portion of the main scanning so that the image formation spots of the light beams may be arranged at equal intervals. Thus, in the vicinity of the center of the main scanning, in order to prolong the time interval of the radiation, there are arranged, for example, standard radiation patterns in which the radiation is carried out once every 8 clocks, and a radiation pattern in which the radiation is done once every 9 clocks.

Abstract: An exposure device of an electrophotographic apparatus which includes a rotary polyhedral mirror for scanning a plurality of laser beams on a photosensitive body, a beam interval adjusting member for adjusting an interval between the laser beams, a rotating mechanism for rotating the beam interval adjusting member, and an optical path position deciding device disposed on the side of the rotary polyhedral mirror in a laser beam advancing direction at the time of adjustment of the laser beam interval, the beam interval adjusting member being rotated so that the optical paths of the laser beams are decided by the optical path position deciding device. The optical path position deciding device may include a plate-like member with boresights or a CCD sensor and a CRT display.

Abstract: In order to improve an apparatus for generating an image in an image plane that is visible, in particular, for a human eye, comprising a radiation source which generates an image via an optical projection means by building up at least one row of image spots during an image build-up cycle by illuminating individual, adjacently located image spots and periodically repeating the image build-up cycle, so that it is possible to generate images as simply and, therefore, also as inexpensively as possible, it is suggested that a row of light sources comprising a plurality of semiconductor emitters be provided for the illumination of the image spots of the row of image spots, that the optical projection means associate each exit spot for the radiation of each semiconductor emitter with at least one of the image spots and that the optical projection means simultaneously image the exit spots of all the semiconductor emitters of the row of light sources onto the image spots associated therewith.

Abstract: A scanning optical device includes a light source, a polygon mirror having a plurality of reflecting surfaces for deflecting a light flux emitted from the light source to form a scanning beam spot on an image surface, an identifying device that identifies which reflecting surface is currently scanning the light flux, a memory that stores data corresponding to shape errors of the reflecting surfaces, a correcting member that corrects a position of the beam spot, and a controller that controls the correcting member in accordance with an output of the identifying device and with data read from the memory. The correcting member is controlled to compensate for deviations of the beam spot due to tilt errors of the reflecting surfaces and may also be controlled to compensate for deviations of the beam spot due to an unevenness of the movement of the image surface.

Abstract: A laser drawing apparatus is provided including a splitting means for splitting laser light emitted from a laser source into at least two groups of drawing beams, the beams of each group being aligned in a common plane; a scanning means for scanning a drawing surface with said at least two groups of drawing beams in a main scanning direction; a first adjusting means for rotating the common plane, in which one of the at least two bundles of drawing beams are aligned, about an axis extending parallel to the drawing beams; a second adjusting means for moving at least one of the at least two groups of drawing beams in said main scanning direction of the scanning means; and, a third adjusting means for moving at least one of the at least two groups of drawing beams in a sub-scanning direction perpendicular to the main scanning direction.

Abstract: A laser drawing apparatus is provided including, a first beam splitting element for splitting laser light emitted from a laser source into a plurality of beams, a second beam splitting element for splitting the beams split by the first beam splitting element into a plurality of groups of drawing beams, optical modulators which provide separate ON/OFF drawing data to the respective split drawing beams split by the second splitting element, a beam combining element for combining the split drawing beams to which the ON/OFF drawing data has been provided, and a beam scanning element for scanning a drawing surface on which an image is to be formed with the combined drawing beams.

Abstract: A semiconductor laser array emits a plurality of laser beams. A polygon mirror deflects the plurality of laser beams together. A prism type reflector separates the deflected laser beams to different directions that are generally along an arrangement direction of a plurality of photoreceptors. The separated laser beams are input to the respective photoreceptors through mirrors and cylindrical lenses.

Abstract: The present invention provides an image forming apparatus, which can provide a color image having no color shift with low manufacturing cost, and an optical exposer unit applied to the image forming apparatus. Thereby, the image forming apparatus comprises a finite focus lens for providing a predetermined optical characteristic to the laser beam sent from a plurality of light sources, a cylinder lens, a laser synthesizing mirror unit for synthesizing the laser beams passed through the lenses into one flux of beams, a deflector for deflecting the synthesized beam, first and second image forming lenses for shaping aberration characteristics provided on the image-formed position of the deflected beam, and one or three mirrors for emitting the beam passed through the respective image forming lenses at a predetermined position, thereby a color image having no color shift can be provided.

Abstract: In the improved image exposing apparatus, light beams of different wavelengths in narrow bands that issue from a plurality of light sources are admitted into a light deflector at different angles and substantially the same main scanning line defined on a light-sensitive material is scanned sequentially at predetermined time intervals by the reflected and deflected light beams. The apparatus is so designed that only one light beam will be admitted into a start synchronizing sensor when start synchronization is to be effected.

Abstract: This invention has as its object to provide an image forming apparatus which can provide a color image free from any color misregistration with low cost, and a light scanning unit suitable for the apparatus. The apparatus includes a finite lens and a cylinder lens for giving predetermined characteristics to light beams emitted by a plurality of light sources, a laser synthesis mirror unit for synthesizing laser beams passing through the lenses, a deflection unit for deflecting the synthesized light beams, first and second image-forming lenses for adjusting the aberration characteristics, at the imaging position, of the deflected light beam, one or three mirrors for outputting the light beam passing through the image-forming lenses at predetermined positions, and can provide a color image free from any color misregistration.

Abstract: An image writing apparatus has improved performance of image reproduction based on a multi-beam scanning optical system, in which the number of laser beams n and the spacing of scanning lines p meet the condition: 1/(n.multidot.p).gtoreq.4 line pairs per millimeter. The optical system is further designed such that the number of deflection planes q of the deflector, a natural number m, where the period of repetitive patterns of image in the slow scan direction is equal to p multiplied by m, and the least common multiple E of m and n, or the least common multiple G of m, n and q meet the condition:1/(E.multidot.p).gtoreq.4 or 1/(G.multidot.p).gtoreq.4 line pairs per millimeter.

Abstract: A laser engraving head (6) for use in preparing a medium for a printing process includes a deflector (AOM). The deflector, which may be an acousto-optic modulator, deflects the laser beam which is focused by a lens (L) onto the surface of the medium. The lens (L) may be arranged telecentrically with respect to the deflected laser beams so that the exit pupil (P) defined by the range of deflected beams is located at the back focal plane of the means for focusing. A number of interchangeable beam expanders (20) may be provided mounted within the head and moveable so that one of the expanders is brought into the path of the beam to provide a desired cell size. Control circuits for the head may modify the control signal applied to the deflector compensate for variations as a function of deflection angle in the cell size produced on the medium.

Abstract: An output scanner for recording an image on a radiation sensitive medium comprises an at least part cylindrical support which carries the medium in use, the medium facing radially inwardly. A scanning unit is positioned radially inwardly of the support and has a generator for generating a plurality of modulated radiation beams, the beams being modulated with respective image information, and a reflector for reflecting the two beams onto the medium at respective, different positions. Optics focus the beams onto the medium. Motors cause relative rotation and traverse movement between the scanning unit and the support about and along the axis of the support respectively.

Abstract: An exposure method which has a step of offsetting a first scanning line bend by scanning means with a second scanning line bend by an image forming lens, and/or a step of correcting angles of optical axis of a plurality of light beams in accordance with the amount of a deviation in a subscanning direction due to a difference of the angles of incidence, so that a distance between scanning lines on a photosensitive body due to the plurality of light beams is corrected.An image forming apparatus which has an image forming lens for producing a second scanning line bend is so as to offset a first scanning line bend by scanning means, and/or correcting means for correcting angles of optical axis of a plurality of light beams in accordance with the amount of a deviation in a subscanning direction due to a difference of the angles of incidence, so that a distance between scanning lines on a photosensitive body due to the plurality of light beams is corrected.

Abstract: An optical scanning system which converges light flux on a photoconductive member by an optical scanning lens after the light flux from a light source is coupled by a coupling lens (a condensing lens) and reflected by a polygonal mirror. The optical scanning system includes an area light emission source, the area light emission source and the photoconductive member being provided with geometrically-optically conjugate relations.

Abstract: In a raster output scanning system (ROS) of a xerographic printing device, a plurality of input optical channels direct at least one of a plurality of light beams onto separate facets of a deflector, which may be a rotating polygon mirror. The deflector deflects the light beams onto disparate optical paths. An optical system located on the disparate optical paths directs at least one of the light beams onto each of first, second, third and fourth image receiving locations. The image receiving locations may comprise a plurality of photoreceptors.

Abstract: A printing apparatus includes an imaging system which focuses a plurality of different color LED sources on a photosensitive recording medium without use of any refractive optics. The imaging system comprises two concave mirrors having reflective surfaces, each of which is a conic section, and a baffle located between the mirrors. Each of the mirrors includes an aperture and the baffle is located between the apertures of the mirrors. A printing method utilizing the apparatus includes reflection of light generated by the LED sources between the mirrors following a series of zigzag turns, convergence of the light through an aperture in one of the mirrors, and formation of an image on a photosensitive recording medium without passing through refracting optics, wherein the baffle blocks light from propagating directly towards an imaging surface without reflecting in the imaging system.

Abstract: A real-time calibration instrument on a processless writing device reads a pattern of marks produced by the device and adjusts writing parameters in real time through feed back mechanisms to modify the characteristics of the marks and their pattern. The calibration instrument includes a photoelectronic camera defining an optical axis perpendicular to the recording medium, and the marks are illuminated coaxially along the same axis to capture an image of the marks without distortion. According to other features, the recording medium is rotated on a drum relative to the recording head and the illumination is provided by a stroboscopic source synchronized with rotation of the drum.

Abstract: A method and apparatus for recording on an optically-sensitive medium by providing a plurality of light sources each emitting a source beam of light of different wavelengths falling within the sensitivity range of the optically-sensitive medium; combining, by wavelength multiplexing, the plurality of source beams into a combined beam; and directing the combined beam onto the optically-sensitive medium.

Abstract: A raster scanning optical system and method emits a first light beam and a second light beam onto a light receiving member. A scanning device has at least one facet for reflecting the first and the second light beams to the light receiving member. A light transmissive plate is located in a path of the first light beam between the first light emitting device and the scanning device. The light transmissive plate adjusts the sagittal direction and the tangential direction of the first light beam by a desired amount so that the first and second light beams are reflected from positions of the scanning device that are closer to each other and parallel in both the sagittal and tangential meridian.

Abstract: An image forming apparatus including an image bearing member, a charging unit, a laser beam scanning apparatus and a developing unit. The laser beam scanning apparatus includes a semiconductor laser array for emitting laser beams, a collimator lens for collimating the beams, a rotating polygon mirror for deflecting the beams collimated by the lens, and an aperture stop between the laser array and the mirror. The following relations between the aforementioned elements of the apparatus are satisfied: ##EQU1## where f is a focal length of the collimator lens; s is a distance between a focal point on a mirror side of the collimator lens and the aperture stop; t is a distance between one of the light emitting portions that is spaced farthest, relative to others of the light emitting portions, from the optical axis; D is a diameter of the aperture stop, and d is a diameter of each of the laser beams collimated by the collimator lens.

Abstract: An image recording apparatus and method use an acoustooptic element as a shutter element and as a device to scan two different beams. The beams are diffracted by modulating the acoustooptic frequency of the acoustooptic element to form band-shaped spot rows on a moving image recording medium. The spot rows include a first beam row and a second beam row that are incident on the image recording medium at different times. The positions of the adjacent beam spots of the first beam row are adjusted relative to the positions of the adjacent beam spots of the second beam row.

Abstract: An apparatus for exposing photosensitive materials includes a plurality of light sources for generating beams having different wavelengths, a polygon mirror for scanning and exposing the beams toward a color photosensitive material, and one or more f.theta. lenses disposed on an optical path between the photosensitive material and the polygon mirror. The polygon mirror and the f.theta. lenses are arranged, with respect to the beam from a light source having an intermediate wavelength among the light sources, such that reflection points corresponding to both ends of beam scanning on reflection surfaces of the polygon mirror pass through an identical point on an optical axis of the f.theta. lenses, and light beams at the both ends of beam scanning have line symmetry with respect to the optical axis of the f.theta. lenses.

Abstract: In an apparatus for exposing a set of discrete locations on a photosensitive surface, such as an electrophotographic printer, a scanner transmits a light beam along a scan path onto the photosensitive surface. An optical element, interposed in the scan path between the photosensitive surface and the scanner, defines a plurality of apertures therein where no more than one aperture is disposed at any location along a linear dimension of the optical element parallel to the scan direction. The light beam transmitted through each aperture exposes a discrete location on the photosensitive surface.

Abstract: The present invention is a novel raster output scanner (ROS) configuration that employs modulated laser diodes as the light source. Each laser diode is coupled to a dedicated driver that modulates the light beam according to digital video signal data. The present invention employs a single-channel acoustic-optic cell that deflects the multiple beams to maintain proper facet tracking. A single transducer is coupled to the single-channel acoustic-optic cell that generates the necessary acoustic wave to maintain proper tracking.

Abstract: Images or other information is recorded by a thermal recording apparatus on a thermosensitive recording medium which has a support coated with a coloring agent, a color developer, and light-absorbing dyes, and produces color whose density depends on thermal energy that is applied to the thermosensitive recording medium. The thermal recording apparatus has a plurality of laser beam generators for generating respective laser beams, and an optical scanning system for scanning the thermosensitive recording medium with the laser beams at respective different positions thereon. One of the laser beam generators produces a laser beam to scan the thermosensitive recording medium earlier than the laser beams generated by the other laser beam generators, and the laser beam has a thermal energy which is high enough to enable the thermosensitive recording medium to produce the color. The laser beam generators apply the respective laser beams at different incident angles to the optical scanning system.

Abstract: A laser beam of a constant intensity is generated by a semiconductor laser and applied to a thermosensitive recording medium. The density of a colored recorded area of the thermosensitive recording medium is detected by a densitometer, and shading correcting data for making the density of the colored recorded area constant based on the detected density are stored in a shading data memory. A controller reads the stored shading correcting data and controls the intensity of the laser beam generated by the semiconductor laser based on the shading correcting data for thereby compensating for variations in the level of an image signal due, for example, to intensity irregularities of the laser beam applied to the thermosensitive recording medium and irregularities of the speed at which the thermosensitive recording medium is scanned with the laser beam.

Abstract: Laser marking systems (60, 80, 160, 250) having increased part throughput are obtained by disposing diffractive optics (70, 70A, 94, 170, 252) across a primary laser beam. Preferred diffractive optics for high power marking lasers are defined in optical materials with discrete surface levels.

Abstract: A system for eliminating differential scan line bow from raster output scanners aligns at least the chief exit ray of each scanning light beam with the system axis. By aligning the chief exit rays to be essentially parallel to the system axis, the overall bow is reduced, and the bow of different scan lines is essentially identical. Thus, bowed scan lines from different stations in a multi-station printer, or from different passes in a multi-pass printer are generally identical and aligned.

Abstract: The present invention is a thin film coating that may be applied to various optical elements and a method for controlling the size of the imaging spot from multiwavelength sources in an optical path. A selective optical element made in accordance with the principles of the present invention comprises an optical surface. Upon the surface, thin film coatings are deposited that define zones of transmission, each zone transmits a desired wavelength band. Beyond this zone, the surface is effectively opaque to a specified wavelength band. The zones for each wavelength are individually calculated to give an effective aperture for each wavelength such that the spot size for all wavelengths meet user specifications.

Abstract: A laser printing system includes plurality of N channel where each channels includes a laser diode forming a laser light beam which is shaped by a beam shaper to correct for divergence differences between the lasers of the N channels. The plurality of N output laser light beams from the plurality of N beam shapers are circular in cross-section, and are combined at a stop aperture in a stop plane with a predetermined angular separation. Various techniques are disclosed for combining the plurality of N output laser light beams. An optical system relays the combined plurality of N angularly separated output laser light beams at the stop plane to a light sensitive print medium to form a spot for each laser light beam. The spots are then scanned across the print medium to print a desired image.

Abstract: An optical head and printing system for printing an image on a light sensitive print medium includes polarized beam splitting means, and a first and a second group of lasers. The polarized beam splitting means passes light beams with a first polarization propagating from a first surface to a second opposing surface thereof, and reflects light beams with a second orthogonal polarization propagating from a third surface to the second surface thereof. The first group of lasers are disposed in a first plane adjacent the first surface of the polarized beam splitting means for transmitting a first group of diverging laser light beams which are polarized with the first polarization. The second group of lasers are disposed in a second plane adjacent the third surface of the polarized beam splitting means for transmitting a second group of diverging laser light beams which are polarized with the second polarization.

Abstract: In an optical output device in which a beam of light is generated, focused to a spot, and scanned across an image plane to form a scan line, scan line curvature caused by offset between at least one light source and an optical axis of the device is corrected. The invention may be embodied in an apparatus that includes a light source capable of emitting the beam of light at a selected one of at least two selectable wavelengths and a deflecting element such as a prism that refracts the beam of light by an amount that depends on the wavelength of the beam.

Abstract: A monolithic array of surface emitting lasers is used in a printer engine to illuminate a photosensitive surface.

Abstract: An electro-optic imager, used for exposing photosensitive media imagewise, wherein an array, e.g. two or more linear arrays, of light sources are imaged onto a rotating drum, to produce images in bands. Apertures are used to shape the beam energies. The use of two or more linear arrays with interlaced imaging allows aperture shapes to be used which precisely control the region of overlapping exposures. With properly shaped apertures, scanning artifacts (e.g. aliasing) can be nearly eliminated.