Abstract: Apparatus for adjusting the focus of an imaging apparatus is disclosed. The imaging apparatus includes a lens assembly which is attached to focus adjustment apparatus. The focus adjustment apparatus includes a pair of parallel flat springs attached at one end to a member supporting the lens assembly and an adjusting mechanism operative to cause the attached lens assembly to be moved so that the lens assembly moves in small increments while remaining perpendicular to the image being scanned.

Abstract: An optical scanner assembly for exposing an image on a scanned surface. The optical scanner assembly includes a laser mechanism for producing a laser beam representative of the image to be exposed on the scanned surface. The laser beam defines an optical path between the laser mechanism and the scanned surface. A laser beam shaping system is positioned along the optical path for focusing and shaping the laser beam onto the scanned surface. A scanning and directing system is provided for directing the laser beam to the scanned surface and scanning the laser beam across the scanned surface in an image-wise pattern. A unibody attenuation mechanism is positioned along the optical path for power attenuation of the laser beam, wherein the unibody variable density power attenuation mechanism is a linear density wedge.

Abstract: The multi-beam optical unit of the invention limits the number of reflection times by half mirrors to one time or below when a plurality of beams are combined into one and guided to a polygon mirror, so that an influence upon an image due to a positioning error of the half mirrors can be minimized. Besides, power of emitted beams can be made uniform by using the half mirrors having transmissivity and reflectance satisfying predetermined conditions regardless of the number of times that the beams penetrate the half mirrors. Thus, the service lives of a plurality of beam emitting sources can be made uniform, and maintainability can be improved.

Abstract: A multi-beam exposer unit 1 includes ##EQU1## half mirror 11 for synthesizing ##EQU2## light to M groups of light beams, M sets of optical members 12, having positive power with a large absolute value as compared with a case of a main scanning direction, for further converging the beam in a sub-scanning direction, a synthesizing reflection mirror 13 for reflecting M groups of beams to be substantially overlaid on each other in a first direction, a polygon mirror unit 5 for deflecting M groups of beams, and a dust prevention glass 14 inclined to a direction opposite to a direction where the half mirror is inclined, thereby reducing influence of coma aberration exerted on M groups of beams by the half mirror.

Abstract: In a scanning optical system in which image-surface curvature in the traverse direction is corrected properly without degrading imaging performance in the scanning direction and in which the transverse magnification is approximately uniform irrespective of the deflection angle, the influence of form errors in the imaging lens upon the image is substantially suppressed so as not to degrade the quality of the image. The scanning optical system is provided with a aspherical lens having a refractive power only in the traverse direction and having a TSL shape whose curvature radius increases as the distance in the scanning direction from the center of the lens (the position in which the curvature radius in the traverse direction is smallest) increases. The aspherical lens is disposed in such a way that the line of symmetry that passes through its center is parallel to and at a distance from the optical axis of a first lens unit on the upstream side of a scanning path in the scanning direction.

Abstract: Energy distribution at a section of a laser beam is leveled by causing the laser beam, emitted by a continuous wave Q-switch pulse from a laser oscillator having an acousto-optic Q-switch element, to pass through a mask having a mask pattern. The laser beam having passed the mask is reflected by a pair of reflection mirrors provided on a pair of galvanometers. The reflected laser beam passes through an objective lens and is focused on a processing object. A desired character or sign is marked on the processing object through a scanning with the laser beam focused on the processing object by driving a pair of galvanometers.

Abstract: A focusing apparatus (10) for maintaining a first beam in focus at an imaging plane comprising a first reflective surface (14) which redirects the first beam from a first direction to a second direction wherein the second direction is oriented approximately 90.degree. from the first direction; a second reflective surface (24) which redirects the first beam from the second direction to a third direction wherein the third direction is oriented approximately 90.degree. from the second direction; a third reflective surface (26) which redirects the first beam from the third direction to a fourth direction wherein the fourth direction is oriented approximately 90.degree. from the third direction; a fourth reflective surface (32) which redirects the first beam from the fourth direction to a in a fifth direction wherein the fifth direction is oriented approximately 90.degree.

Abstract: A grating modulator array (40) is comprised of a plurality of modulator sites (41). Each modulator site (41) is comprised of a plurality of first poled regions (50) and a plurality of second poled regions (51) alternating with said first poled regions. A first electrode (48a) is attached to a first end of each of the modulator sites and a second electrode (48b) is attached to a second end of each of the modulator sites and each of the electrode pairs establishes a field in the poled regions of the modulator sites which causes a phase shift in polarized light incident on the modulator.

Abstract: A dual resolution printer for printing images on an associated print medium includes: a light source providing a light beam and a focusing lens focusing the light beam and creating a converging light beam having at least one beam waist of at least one wavelength at a first beam waist location. The printer also includes an optical unit movable in and out of the converging light beam and having a corresponding first and second position, respectively. This optical unit, in the second position, reimages the beam waist of the converging light beam created by the focusing lens to a different size second beam waist, at a location substantially the same as the first beam waist location.

Abstract: A multi-beam scanning apparatus includes a light source unit for emitting a plurality of beams, a beam deflector for deflecting the plurality of beams from the light source unit, and a common scanning image-forming optic for converging the plurality of deflected beams so as to form a plurality of beam spots for simultaneously scanning a scanned surface, a plurality of scan lines respectively described by the plurality of beam spots being isolated from each other in a sub-scanning direction, wherein the plurality of scan lines are bowed in the same direction.

Abstract: A scanning optical apparatus includes a light source, deflector for deflecting a light beam emitted from the light source, and optical device for directing the light beam emitted from the light source onto a surface to be scanned. The optical device includes a diffracting optical element. An aberration fluctuation in a sub-scanning direction resulting from environmental fluctuation of the scanning optical apparatus is corrected by the characteristic of the optical device.

Abstract: A multi-focusing laser beam recorder and a multi-focusing method includes first and second light sources for generating a Kr laser beam for recording light and an He--Ne laser beam for focusing. A fixed optical system modulates the Kr laser beam for recording light and divides the beam into a main beam and a sub beam on each of different paths. An optical divider divides the main beam or the sub beam incident through a shutter of the fixed optical system and the He--Ne laser beam incident from the second light source. A focus servo focuses either the main beam or the sub beam from the optical divider and the He--Ne laser beam on a predetermined area of the glass substrate. First, second and third position sensor controllers control the focus servo to focus the He--Ne laser beam on the glass substrate in response to the pit width of the glass substrate by sensing the laser beam for focusing reflected upon the glass substrate.

Abstract: A color printer for imaging on an image plane includes: (a) a plurality of light sources, each of the light sources being adapted to provide a spatially coherent, composite beam of light, each of the composite beams including a plurality of spectral components; (b) a single beam shaping optics accepting the composite beams, the beam shaping optics having optical elements adapted to shape said composite beams by a different amount in a scan direction and a cross scan direction, so as to form for each of the composite beams (i) a first beam waist in the cross scan direction of the composite beam and (ii) a second waist in the scan section of the composite beam, the first and second beam waists being spaced from one another; (c) a deflector adapted to move said plurality of composite beams across the image plane, the deflector being located closer to the first beam waists than to the second beam waists; and (d) scan optics located between the deflector and the image plane, the scan optics being adapted to (i) ge

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 tandem type multi-color image forming apparatus capable of outputting a multi-color image can improve output speed of a monochrome or limited color image output. The image forming apparatus includes a single laser beam source, a plurality of image forming units, and a single polygon body. The polygon body is provided with the plurality of reflector surfaces respectively corresponded to the plurality of image forming units. The apparatus also includes an optical path selecting optical system movable into optical paths of the laser beam reflected from the rotary polygon body for deflecting the laser beam reflected from the rotary polygon body toward selected limited number of image forming units and a control portion for varying operation speed of the selected limited number of image forming units.

Abstract: A method and apparatus for delivering laser energy to an object, by: energizing at least one laser energy source having a plurality of at least two spaced, active segments to emit a laser beam from each segment, and to thereby output from the laser energy source a plurality of separate laser beams along respective optical axes initially spaced from each other according to the spacing of the active segments, which beams tend to diverge and thereby to overlap as they progress along their respective optical axes; and at a near-field region of the at least one laser energy source or a region optically conjugative with the near-field region, where the beams are still separated and spaced from each other, laterally displacing the optical axis of at least one of the beams with respect to that of the other before delivering the plurality of beams to the object.

Abstract: An image forming machine includes an exposure unit and a pressure development unit for forming an image on a microcapsule coated sheet. The exposure unit includes a plurality of light emitting elements, a substrate having reflective recesses formed in the surface thereof, the plurality of light emitting elements being disposed in the recesses, and a mask having openings formed opposite the plurality of light emitting elements. The reflective recess prevents light from the light emitting element from exiting through the pinhole other than the pinhole opposed to that light emitting element, thus improving the efficiency of utilization of exposure light. A partition may be provided between the light emitting elements.

Abstract: An imaging processor for receiving a medium for processing, the processor comprises a print head for providing and for directing a writing laser beam. A laser source also disposed in the image processor for creating a focusing laser beam for ultimately permitting adjustment of the writing laser beam. An imaging receptacle receives the medium and is exposed to both the writing and focusing laser beams, and the writing laser beam is periodically directed from the medium, to the imaging receptacle and back to the medium. A laser-absorbent coating is coated onto the imaging drum for absorbing the focusing laser beam that is received by the imaging receptacle for substantially eliminating transient oscillations in the writing laser beam.

Abstract: A printer system for producing color prints includes: (a) three light sources, each generating a light beam of different wavelengths; (b) three modulators, each of the modulators modulating intensity of each of the light beams by image data, to provide three modulated light beams; (c) a beam combiner combining the three modulated light beams into a single light beam; (d) a single set of beam shaping optics shaping this single light beam into a shaped light beam having different vergences and waist locations in the page and line directions, the vergences and the waist locations being substantially the same in each of the three wavelengths; (e) a light deflector deflecting the shaped light beam to provide a deflected beam, and performing a scanning function; (f) an f-.theta. lens focusing the deflected light beam onto an associated image surface.

Abstract: An optical scanning device for deflecting a plurality of light beams is disclosed. The device includes a plurality of deflection means for deflecting each of the plurality of light beams. The means are formed in a thin film waveguide, and distributes a refractive index of the waveguide by an electro-optic effect according to input signals to cause diffraction due to the distributed refractive index, thereby deflecting a plurality of light beams.

Abstract: An LED head for illuminating a surface of a photoconductive body includes an LED circuit board, lens assembly (SLA), SLA holder, base, and engagement member. The LED circuit board has LED arrays mounted thereon. The lens assembly has an optical axis and focuses light emitted from the LED arrays on the surface of the photoconductive body. The SLA holder has two opposing walls to hold the lens assembly therebetween. One of the opposing walls has a first reference surface with which the optical axis of the lens assembly is in a predetermined positional relation and urges the lens assembly against the other of the opposing walls. The base houses the LED circuit board and the SLA holder therein. The base has a second reference surface such that the optical axis is placed in position with respect to the LED arrays when the second reference surface is in intimate contact with the first reference surface.

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: In an image forming apparatus, an image is formed pixel by pixel for each image data on a photoreceptor, wherein each pixel has a maximum recording width. A plurality of light emitting elements are aligned in an array form and each light emitting element is mounted with a setting width, wherein each light emitting element has a mount-shaped light amount distribution curve in which light amount data spread to both sides of a peak corresponding to the maximum light amount. Each pixel is divided into plural small pixels. Each small pixel is provided with a light emitting element so that an image is formed in the maximum recording width of each pixel by plural neighboring light emitting elements in accordance with image data of each pixel, wherein the image forming width at the light amount of 50% of the maximum light amount of each light emitting element is wider than the setting width of the light emitting element and is narrower than the maximum recording width of each pixel.

Abstract: An image forming device wherein a Gaussian laser beam is scanned imagewise on a photosensitive recording medium by an image forming optical system including an optical filter having such a laser beam filtering pattern that the optical transmittance is a minimum value M of 40-60% at the center thereof and gradually increases from the center in the radially outward direction in a Gaussian distribution mode. The filter has a filtering radius R.sub.f which is a distance between the center and a point on the filter providing a transmittance equal to 100-(100-M)/e.sup.2 % and which is not smaller than 0.9 R.sub.b but not greater than 1.1 R.sub.b where R.sub.b is a beam radius of the Gaussian laser beam.

Abstract: A bouncing ball scanner is described which is a ball driven in a reciprocal motion for reflecting image-bearing light onto a photosensitive medium. The image-bearing light can be dictated by a computer, in which case the photosensitive medium may be film for a printed output, or the image-bearing light may be reflected from a subject having an image imprinted thereon, and the photosensitive medium may be a charge coupled device where the image is being read into a computer. The bouncing ball scanner comprises a ball being driven in a reciprocal motion by electromagnetic forces acting thereon. The motion of the bouncing ball is substantially linear in each direction so as to allow ease of calculation of ball position thereby ease of knowledge of pixel position on the photosensitive medium.

Abstract: A scanning optical apparatus includes a light source device, a first optical element for converting a beam emitted from the light source device to a converging light beam, a deflecting element for deflecting the beam emitted from the light source device, a second optical element for focusing the beam emerging from the first optical element in a linear shape longitudinal in a main scanning direction on a deflective face of the deflecting element, and a third optical element for focusing the beam deflected by the deflecting element in a spot shape on a scanned surface.

Abstract: An image-wise exposure apparatus comprises a light source for producing recording light, to which a photosensitive material is to be exposed, and a spatial modulation device provided with a plurality of picture elements located in the form of a two-dimensional array. The spatial modulation device raster-scans the picture elements and thereby carries out spatial modulation of the recording light. A picture element shifting device changes the optical relationship between the spatial modulation device and the photosensitive material. A controller sets all of the picture elements of the spatial modulation device to a totally closed condition for a single frame period and drives the picture element shifting device while all of the picture elements of the spatial modulation device are being in the totally closed condition. Effects of a picture element shifting operation are thereby obtained sufficiently, and image-wise exposure is carried out quickly.

Abstract: A laser beam scanning apparatus and method for providing controllable print density. The laser beam scanning apparatus includes a modulator for modulating a light beam, a rotating polygon mirror for deflectively scanning a light beam which is passed through the modulator, at least one lens unit having at least one lens which is movable to a position on the optical axis and a position completely off the optical axis, and a controller for switching the modulating clock frequency of the modulator and the rotating speed of the polygon mirror together with selective shifting of the at least one lens unit or lens thereof to a position on the optical axis or completely off the optical axis whereby the method effects control of the apparatus for controlling print density.

Abstract: An optical scanning device includes a light source having a plurality of light-emitting portions, a deflector for deflecting a plurality of light beams emitted by the light source, optical elements for guiding the plurality of light beams emitted by the light source toward the deflector and an imaging element for guiding the plurality of light beams deflected by the deflector onto a surface to be scanned. A polarization limiting element is inserted in an optical path between the light source and the deflector so as to limit directions of polarization of the plurality of light beams.

Abstract: An image recording apparatus has an array light source having a plurality of light-emitting elements arrayed in a predetermined density; a photosensitive member exposed to light beams emitted from the plural light-emitting elements so that images are recorded by fixing a traveling path of the light beams from the plural light-emitting elements to the photosensitive member and by moving the photosensitive member relative to the array light source; a beam-converging unit which intercrosses a bundle of the light beams emitted from the light-emitting elements onto a beam-conversion point; and an focusing unit disposed between the beam-converging unit and the photosensitive member, which images the light beams emitted from the plural of light-emitting elements and intercrossed by the beam-converging unit onto the photosensitive member.

Abstract: The present invention allows output of image data without change when input image data and image data to be outputted have different resolutions and also allows reduction in a processing time and improvement in operating efficiency by providing an image recording apparatus. Some of lenses which form a telecentric lens system (optical system) are provided such that positions thereof in a direction along an optical axis can be varied by drive of a pulse motor 10. Due to the movement of these lenses, an imaging spot diameter on a photosensitive material is varied. The spot diameter is varied based on a resolution of the input image data. When the resolution of the input image data is lower than a previously set resolution, with the volume of the image data being left unchanged and the imaging spot diameter being increased, the previously set resolution is varied and recorded.

Abstract: A color printer uses multiple linear arrays of surface emitting lasers of differing wavelengths and polarization states to simultaneously expose widely separated positions on the same or different photoreceptors. Each array is imaged by the same optical system to the photoreceptor. The multiple linear arrays can be closely spaced in a monolithic structure.

Abstract: A printing apparatus having a fixed focal point for a recording medium to which the printing apparatus writes, the apparatus comprises a rotor; an intensity-modulated light source adapted to emit a light beam along an optical path; a platform having three variably positioned ball feet to which platform the light source is fixed for maintaining the positional relationship of the light source in relation to the focal point; a plate having three grooves attached to the printing apparatus which cooperatively receives the ball feet; and a housing that receives the plate and platform and cooperatively attaches to the rotatable rotor to move the light source for scanning the light beam along the recording medium, for permitting removal and replacement of the light source in a precise fashion.

Abstract: There is disclosed a printing system in which an array of VCSELs as a light bar print head directly sends an array of light beams onto a photoreceptor without using an imaging optical element. In this invention VCSELs are selected to have a slowly diverging light beams. A photoreceptor is placed at a certain distance from the VCSELs where the light beam has a width equal to a desired spot corresponding to a given printing resolution.

Abstract: A color spatial light modulator has red, green, and blue micromirror arrays juxtaposed in parallel. Each micromirror array has a number of micromirrors each formed with a filter for reflecting specific color light. As data "1" is written to a memory cell of an SRAM, the micromirror tilts by +.theta. and enters a valid reflection state in which spot light is utilized. As data "0" is written, the micromirror tilts by -.theta. and enters an invalid reflection state in which spot light is not utilized. A data write control circuit converts image data into mirror drive data and writes it to SRAM. Three-color parallel line light beams generated by the three-color micromirror arrays are projected by a projector lent onto color paper. A three-color image is printed line sequentially on the color paper.

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: Through an imaging lens, respective luminous fluxes from a semiconductor laser array light source comprising a plurality of semiconductor laser devices arranged in a row form images on a photosensitive surface, thereby effecting light dot formation (light scanning) on a surface to be scanned without using mechanical light-scanning means such as polygon mirror. The laser printer apparatus comprises a semiconductor laser array light source (1) composed of a number of semiconductor laser devices (light-emitting devices; 1a) arranged in a row, and an imaging lens (3) for forming images of the luminous fluxes from the respective light-emitting devices (1a) in a row on a photosensitive surface (2). The semiconductor laser array light source (1) comprises not less than 700 pieces of minute semiconductor laser devices (1a) arranged in a row and is adapted to modulate laser beams from the respective devices (1a) independently of each other.

Abstract: Apparatus and methods for exposing multilayered thermal imaging media to eliminate "cloud" or "woodgrain" artifacts by proper optimization of the exposing radiation angle of incidence. The exposure angle of incidence is large enough so that all rays with high reflectance loss are paired with equally many with low reflectance loss to increase printing efficiency.

Abstract: In order to improve the resolution of a LED printing head by a comparatively simple method, optical shutters (28) are provided between two rows of rod lens arrays (26) and LED arrays (18) correspondingly to the rod lens arrays (26). The central optical axes of rod lenses (24) in the rod lens arrays (26) are inclined by an angle of inclination 0 in the opposite directions with respect to the direction of perpendicular lines passing the centers of the light-emitting surfaces of LED's (14), and signal light sent out from the LED's (14) is condensed on a photosensitive surface (20) alternately via predetermined rod lens arrays (26) so that one line is formed on the photosensitive surface (20).

Abstract: A multi-beam optical head includes a plurality of light sources for emitting a plurality of light beams. An optical system for irradiating the light beams onto the recording surface of a recording medium is included and receives the light beams reflected from the recording medium. The optical system includes a reflecting mirror for directing the light beams emitted from the light sources toward the recording medium; a photodetector for detecting the light beams received by the optical system and for generating electric signals based on the detected light beams; and rotational controller for controlling the reflecting mirror to rotate around an axis which is perpendicular to the recording surface by an amount determined based on the electric signals. The reflecting mirror positions the light beams on tracks on the recording surface of the recording medium. The tracks are tracks on which information is recorded from which the information is reproduced.

Abstract: An apparatus for correcting positional deviation of the light source emitting light beams in an image recording apparatus is disclosed which corrects change of the image size (dimensions of the image) on the photosensitive member due to positional deviations of beam spots on the photosensitive member on account of physical distortions caused by external vibration, temperature change, and the like. Changes in the diameter of detective light beams are measured by photodetecting portions 5.sub.R and 5.sub.L and piezoelectric devices 6a and 6b are driven based on the results of the detection, whereby the semiconductor laser array 1 is moved so that the multiplication b/a for the image size may be kept constant.

Abstract: A microlens for a multiple emitter laser diode consists of narrow slices cut out from molded aspheric lenses. Each slice is mounted in front of one emitter and the slice position is adjusted in the cross-emitter direction to have all emitter images aligned in a straight line, thus compensating for any lack of straightness in the multiple emitter diode.

Abstract: An image-setter and a scanning method are disclosed. The image setter includes at least two scanning surfaces, a media conveying system for conveying at least two light sensitive media to respective ones of the scanning surfaces, and an optical system for scanning substantially simultaneously the at least two light sensitive media on said respective scanning surfaces. The scanning method includes the steps of providing at least two scanning surfaces, conveying at least two light sensitive media to respective ones of said scanning surfaces, and employing an optical system for scanning substantially simultaneously the at least two light sensitive media on said respective scanning surfaces.

Abstract: An optical apparatus for correcting deviations from straightness of an array of laser emitters in generally aligned positions along an array direction includes a corrector for aligning the light beam paths in a cross-array direction. A lenslet array shaping optics is provided to direct the light of individual emitters to individual associated regions of the corrector.

Abstract: An image forming apparatus having an exposure optical system provided with an exposure light source in which light-emitting elements are arranged on a base plate to be line-shaped and with a lens array of a distributed refractive index type that converges a beam emitted from the exposure light source on the surface of a photoreceptor and conducts imagewise exposure. The apparatus is configured to satisfy the expression: ##EQU1## In the expression, .DELTA.T1 represents a variation width (K) of the temperature in the vicinity of light-emitting elements, R represents a radius of the photoreceptor mentioned above, Ri represents a length (.mu.m) of each member constituting the exposure optical system in the radial direction of the photoreceptor, .alpha. represents a coefficient of linear thermal expansion (.degree.C..sup.-1) of a transparent base that forms the photoreceptor, .alpha.i represents a coefficient of linear thermal expansion (.degree.C..sup.

Abstract: A projection exposure apparatus includes a projection optical system for projecting a pattern of a first object onto a second object; a laser source; an optical integrator for forming a secondary light source from the laser source; and a condenser optical system for imaging the secondary light source behind the first object at positions different in a direction of an optical axis with respect to two different directions to illuminate the first object therewith.

Abstract: An optical image forming device includes a scanning lens for scanning, in a main scanning direction, eight drawing beams on an image plane. A monitoring beam is scanned repeatedly and simultaneously with the drawing beams in a predetermined scanning range. The eight drawing beams are scanned such that drawing beams adjacent each other in a sub-scanning direction pass a same position in the scanning range on the image plane at a different time. The monitoring beam is scanned prior to scanning of the drawing beam. A scale clock generator is provided for generating scale clock signals identifying positions of the monitoring beam in the scanning range. A modulator modulates the eight drawing beams such that modulations for each of the drawing beams at a same position in the scanning range are synchronized with a timing of a same scale clock signal obtained by the scale clock generator.

Abstract: Light emitted from an array of light-emitting elements in an electrophotographic printer is transmitted through a birefringent plate that deflects light polarized in a first plane but does not deflect light polarized in a second plane perpendicular to the first plane, and through a polarization switching device that is controlled by an electrical signal so as to selectably transmit light polarized in either the first plane or the second plane. The transmitted light illuminates a photosensitive medium. Each light-emitting element can illuminate two dots on the photosensitive medium, depending on the state of the polarization switching device, thereby doubling the dot resolution.

Abstract: Disclosed is a multi-beam image forming system, which has a light emitting unit including a plurality of light sources emitting a plurality of beams, and a table carrying a photosensitive film on which an image is formed with the plurality of beams. A sensor is provided on the table, and light amount of each of the light sources is detected by moving the table and the light source relative to each other. Further, based on the detected light amount of each of the light sources, compensation values are determined. The compensation values are used when the light sources are driven so that the light amount on the photosensitive film accurately corresponds to an image data.

Abstract: An optical scanning apparatus includes a semiconductor laser, a polygonal mirror as a deflector for scanning a light beam from the laser, a photosensitive drum for forming an electrostatic latent image, a converging lens for converging the light beam from the laser onto the photosensitive drum, and a reflection mirror located between the deflector and the photosensitive drum. The reflection mirror is adapted to reflect the light beam so that a light beam reflected by the reflection mirror is used to read a source document placed at a position that is the conjugate of the position of the photosensitive drum surface with respect to the converging device. Inside the casing of the semiconductor laser are a beam splitter for light path separation and a photosensor. The apparatus has an image reader section and a laser printer section, which share a common optical system, thus providing a compact design and cost reduction and also equalizes the accuracy of image reading and printing.