Abstract: A laser beam source that emits a laser beam includes a reflecting unit that has a plurality of reflecting members and reflects the laser beam emitted from the laser beam source, a deflecting and scanning unit that deflects and scans with the laser beam reflected by the reflecting means, and an adjusting unit that moves at least part of the reflecting members, and adjusts the size of the laser beam entering the deflecting and scanning unit.

Abstract: An object of the present invention is to prevent deterioration of image quality caused by ghost light generated from components of a scanning optical apparatus. In the present invention, an image writing light flux is related with a position at which ghost light appears and the exposure amount of the ghost light and a ghost light exposure amount on a surface to be scanned is calculated on comparison with an actual image signal, and the light quantity or the pulse width of a light flux emitted from a light source is controlled based on the calculated ghost light exposure amount.

Abstract: The over-field type optical scanner includes a first imaging optical system disposed between a light source and a rotating polygon mirror for forming, on one surface of the rotating polygon mirror, a linear image with a width larger than a width along a main scanning direction of the one surface of the rotating polygon mirror; and a second imaging optical system composed of a curved mirror for focusing, on a scan surface, a light beam having been reflected by the rotating polygon mirror. The first imaging optical system includes a first conversion optical system for converting the light beam emitted from the light source into a divergent light beam with respect to the main scanning direction and into a convergent light beam with respect to the sub scanning direction; and a second conversion optical system having a refracting power in the main scanning direction.

Abstract: An optical scanner includes a light source that emits a light beam, a deflection unit that deflects the light beam, an optical unit that introduces the light beam to a target surface, a housing unit that stores these components, and a member that contacts the light source and/or the optical unit. The light source and/or the optical unit changes in attitude due to a temperature change while the optical scanner is operating. The member extends or contracts according to the temperature change so as to reduce the change of the attitude.

Abstract: The present invention has as its object to provide a compact optical scanning apparatus of high performance. So, in the present invention, an optical scanning apparatus comprised of two or more reflecting mirrors is of a construction in which the optical characteristics of the mirrors are made different from each other, and an unevenness in light quantity on a surface to be scanned is corrected.

Abstract: Disclosed is an optical scanning system and an image forming apparatus having the same, wherein, in one preferred form of the invention, the optical scanning system includes a light source device, a deflecting device for scanningly deflecting a light beam from the light source device, and an imaging optical system for imaging, upon a scan surface to be scanned, the light beam deflected by the deflecting device, wherein the imaging optical system consists of a single imaging optical element with a light exit surface having a concave shape with respect to a main-scan sectional plane, and wherein relations 0.5??m/?p?0.9 0<dp/kp?0.

Abstract: A motor drive device for driving of a plurality of motors in a proper manner, having a first motor, a second motor, and a current controller. The first motor is able to drive at up to a first maximum permissible current of A1. The second motor is able to drive at up to a second maximum permissible current of B1. The power supply supplies up to a maximum permissible supply current of D to the first and second motors. The current controller controls operations of the first and second motors. The maximum permissible supply current of D is set to be less than a sum of A1 and B1. The current controller controls a first current A2 to be supplied to the first motor and a second current B2 to be supplied to the second motor so that a sum of the first and second current A2 and B2 is less than D. The current controller controls the second current B2 to be less than the second maximum permissible current B1.

Abstract: An optical scanner includes a single deflector to optically scan a plurality of target surfaces to be scanned. The deflector has a common rotary axis for deflecting reflective surfaces and is shared by all the beams from a plurality of light sources. The optical scanner includes photodetectors arranged to receive the beams deflected at the deflector. The beams traveling toward the deflector have an open angle in a deflecting rotation plane. A scanning optical system for guiding the deflected beam to the corresponding target surface includes two or more scanning lenses. A scanning lens proximate to the target surface passes only the beams traveling toward the same target surface. Scanning lenses proximate to the target surfaces for guiding the beams to different target surfaces have optical actions different from each other.

Abstract: An optical scanning apparatus in which streaks in an image or unevenness in density of an image caused by influences of dusts, scratches and toner etc on the surface of a reflecting member are unlikely to occur and excellent images can be always obtained and an image forming apparatus equipped with such an optical scanning apparatus are to be achieved. The apparatus comprises a first optical system for guiding a light beam emitted from light source unit to deflecting unit, the deflecting unit for reflecting and deflecting the light beam from the first optical system, a second optical system for guiding the light beam reflected and deflected by the deflecting unit onto a surface to be scanned through reflecting unit including n (n is an integer equal to or larger than 1) reflecting members.

Abstract: A scanning optical apparatus having stable optical performance even if the characteristic of a vertical cavity surface emitting laser is fluctuated due to increase in drive current, and an image forming apparatus using the same are provided. The scanning optical apparatus comprises a converting optical system for converting a beam from the light source means having plural emission points into a beam of another state, deflecting means, and an imaging optical system for directing the deflected beam onto a scanning surface, and either pair of conditions is satisfied, 3?Fnos<Fnom?15 and d?s/dT<d?m/dT, or 3?Fnom<Fnos?15 and d?m/dT<d?s/dT, where Fnom and Fnos represent F numbers of the light source means side of the converting optical system in main and sub-scanning directions, ?m and ?s half value angles of far field pattern in the main and sub-scanning directions, and d?m/dT and d?s/dT the fluctuations of ?m and ?s due to temperature change.

Abstract: Scanning assemblies, printing devices, and related methods are described. In one embodiment, pole pieces are configured to be coupled with an input voltage source that can produce phase-shifted input voltages, the pole pieces defining at least first and second phases. A rotor is operably associated with the pole pieces for rotation. The pole pieces and the rotor are configured as an induction drive system in which a rotational force for rotating the rotor is produced through interaction of rotor-induced eddy currents from each of the first and second phases with respective magnetic fluxes of the other of the first and second phases.

Abstract: In an lens of a scanner unit, a first incidence surface of a first lens is formed as an aspherical surface rotationally symmetrical with respect to an optical axis while a first emergence surface is formed as a shape asymmetrical in a main scanning direction with respect to the optical axis and having a curvature asymmetrically variable in a sub scanning direction with respect to the optical axis. Each of second incidence surface and second emergence surface of a second lens is formed as a shape symmetrical in the main scanning direction with respect to the optical axis and having a curvature symmetrically variable in the sub scanning direction with respect to the optical axis. A mold for the lens can be produced easily when only the first emergence surface of the first lens can be formed as an asymmetrically variable shape.

Abstract: An optical scanner for an image forming apparatus of the present invention includes a polygonal mirror for steering a scanning beam incident thereto and an optical device located in the vicinity of the polygonal mirror. The polygonal mirror and optical device are supported by a housing. A heat radiation guide adjoins the polygonal mirror and is formed integrally with or separately from the housing. The heat radiation guide has a guide surface inclined relative to the axis of rotation of the polygonal mirror and intersecting a plane virtually formed by a scanning beam.

Abstract: Disclosed is an optical scanning system and an image forming apparatus using the same, which is designed to reduce the overall size of the system and to make uniform the light spot diameter in a sub-scan direction, inside an effective scan region, as well as to ensure high-speed production of high-quality images, wherein the optical scanning system includes a light source, a condensing optical system, a deflector and an imaging optical system having one or more optical elements, wherein, in at least one optical element of the optical elements, the curvature of the opposite surfaces thereof changes continuously, inside an effective region, from the optical axis toward the peripheral portion thereof so that the sign of the curvature is reversed at the middle, and wherein, when the curvature radius of the surface of that optical element facing the deflector side, at the optical axis and in the sub-scan sectional plane, is denoted by rl0 while the least quantity of an absolute value of the curvature radius of the

Abstract: A multi-beam optical scanning apparatus includes a light source in which a plurality of light emitting regions are located at an interval in a main scanning direction, an incident optical system for allowing light beams emitted from the light source to enter a deflector with a state in which a width of the light beams is wider than that of a deflection surface of the deflector in the main scanning direction, and an imaging optical system for imaging the light beams which are reflected and deflected on the deflector on a surface to be scanned. The incident optical system includes a condensing optical system for changing a state of the light beams emitted from the light source. A back focal position of the condensing optical system in the main scanning direction is located on the deflection surface or in its vicinity.

Abstract: A light scanning apparatus capable of printing with a high quality and an image forming apparatus using the same are obtained. The light scanning apparatus is provided with an incidence optical system for guiding a light beam emitted from a light source part to a deflection part; an imaging optical system provided with a diffracting surface having a power at least in a sub-scanning section that guides the light beam deflected by the deflection part on a surface to be scanned; and a surface inclination correction function, in which a principal ray of the light beam is always positioned outside of a main scanning section during scanning. In the light scanning apparatus, each element is set so as to satisfy each conditional expression.

Abstract: System and method for generating lines of data on a photosensitive medium for use with a display or a printing apparatus. The lines of data are generated by two or more modulated and parallel laser light beams onto a resonant pivoting torsional hinged mirror. The pivoting mirror sweeps the two modulated light beams back and forth across the photosensitive medium to provide bi-directional printing. Relative motion between the photosensitive medium and the plane of the sweeping light beam is provided by moving the photosensitive medium when used with a printing apparatus or by also orthogonally moving the sweeping plane of the light beams when used with a display device.

Abstract: An optical scanner includes a scanning unit having a reflecting surface that reflects a laser beam and scans the laser beam in a primary scanning direction, a laser beam radiation unit that radiates laser beams to the reflecting surface from directions at predetermined angles to a reference plane, which is orthogonal to the reflecting surface and extending along the primary scanning direction, and optical members provided on optical paths of the laser beams after reflections. The laser beam radiation unit radiates the laser beams, in such a manner that, an angle on a plane orthogonal to the reference plane between a first and second optical paths is larger than an angle between the first and third optical paths, the second and third optical paths being adjacent to one side and other side of the first optical path, respectively. The optical member on the second optical path is nearer the reflecting surface than the third optical path.

Abstract: An optical scanner includes a light source (1) that emits a light beam, a light deflector (6), an incident optical system (5) that allows the light beam to impinge on the light deflector such that the width of the light beam in the main scanning direction is larger than the width of each deflecting surface of the light deflector in the main scanning direction, and a focusing optical system (8) that guides the light beam deflected by the light deflector to a surface to be scanned. The incident optical system and the focusing optical system are constructed such that aberrations occurring in the two optical systems when a light beam impinges on the surface to be scanned at an off-axis image height are asymmetrical on both sides of the center of the light beam and the directions of the aberrations are opposite to each other.

Abstract: There is provided a multi-beam laser scanning device able to efficiently suppress and prevent density fluctuation and achieve higher image quality. The multi-beam laser scanning device comprises a light emitting source generating a plurality of laser beams, a rotating deflector that has a plurality of deflecting surfaces. On a scanning surface, an interval between a scanning line X generated by deflection of a first deflecting surface of the deflector and a scanning line Y generated by deflection of a second deflecting surface of the deflector and adjacent to the scanning ling X satisfies at least one of the following two equations: ?P?<0.8·Ps ?P?<0.6·Ws where ?P? represents the difference between a maximum interval and a minimum interval between the scanning line X and the scanning line Y, Ps represents an object value of two neighboring scanning lines, and Ws represents the size of a light spot in the sub-scan direction.

Abstract: Provided are compact, high-definition, optical scanning apparatus and multi-beam scanning apparatus capable of keeping the spot size uniform in the sub-scanning direction throughout the entire, effective scanning area on a surface to be scanned. An optical scanning apparatus has an entrance optical system 11 for guiding light emitted from a light source 1, to a deflector 5, and a scanning optical system 6 for focusing the light reflectively deflected by the deflector, on a surface to be scanned 7. In the optical scanning apparatus, the scanning optical system has a plurality of sagittal asymmetric change surfaces in which curvatures in the sagittal direction change on an asymmetric basis in the meridional direction with respect to the optical axis of the scanning optical system.

Abstract: An optical scanning apparatus includes an incidence optical system for causing a beam emitted from a light source to be incident on a deflector, and a scanning optical system for causing the beam reflected and deflected by the deflector to be imaged on a surface to be scanned. The scanning optical system has a first lens on the deflector side and a second lens on the surface to be scanned side. The first lens has positive power in the main scanning direction and has negative power in the sub scanning direction. The power of the first lens in the main scanning direction is greater than the power of the second lens in the main scanning direction, and the second lens has positive power in the sub scanning direction.

Abstract: An optical scanning device, including a resin lens having a power that is an inverse power of scanning lens placed before a deflector. A bundle of rays emitted from a plurality of light sources is coupled into a desired state by coupling lens, after which the bundle of rays is incident on the resin lens. The surface of incidence of the resin lens has a spherical surface with a negative power, and the exit surface of this resin lens has a cylindircal surface with a negative power only in the sub scanning direction. The bundle of rays passes through the resin lens and enters a glass toroidal lens. A light deflector deflects the bundle of rays from the toroidal lens. The deflected bundle of rays is incident on a third optical system that condenses the deflected bundle of rays onto a surface to be scanned.

Abstract: A first f? lens is arranged to form an inclination angle ?1 to a main scanning plane. A second f? lens is arranged to form an inclination angle ?2. In order to determine the inclination angles ?1 and ?2, curvature amounts of scanning lines generated on a scanned surface are measured when the f? lenses are independently inclined one at a time at a minute angle. Change rates K1 and K2 are obtained from the measured curvature amounts and the minute angles. The inclination angles ?1 and ?2 are determined such that |K1?1+K2?2| is no more than a certain value.

Abstract: An optical scanning device has an incident optical system that makes a light beam emitted from a light source unit enter to a deflection surface of an optical deflector in a state in which the light beam has a larger width than a width of the deflection surface in a main scanning direction, and an imaging optical system that images the light beam reflectively deflected by the optical deflector onto a surface to be scanned. In the device, a slit member that restricts a diameter of the light beam in a sub-scanning direction is provided within an optical path between the optical deflector and the surface to be scanned. A peak intensity of a spot of the light beam scanned on the surface to be scanned is made constant, or substantially constant across an entire effective scanning region.

Abstract: An optical scanning device directs a light beam emitted from a light source to a mirror of a mechanical deflector through a first optical system, deflects the light beam in a main scanning direction by causing the light beam to be reflected by a mirror surface of the mirror, the angle of the mirror surface changing due to rotation of the mirror, and directs the deflected light beam through a second optical system to a surface to be scanned moving in a sub-scanning direction, the light source, first optical system and mechanical deflector being contained in a housing. The mechanical deflector is held in the housing through a holding member, and, also, material of the housing is different in heat conductivity from the holding member.

Abstract: In an optical scanning apparatus, a light beam emitted from a light source is deflected and scanned by a light deflecting member, and then scanned and imaged with substantial speed uniformity onto a medium to be scanned by a scanning optical element. The apparatus is configured so that, when the angle formed by the light beam that is deflected and scanned and the optical axis of the scanning optical element is ?, the amount of positional deviation due to deviation from speed uniformity of the light beam on the medium to be scanned is ?(?), the spatial scan density on the medium to be scanned is P, and the maximum of an absolute value of the angle ? is ?o, an expression of |d?(?)/d?|?5.0×10/P?o holds.

Abstract: A multi-beam optical scanning apparatus includes a semiconductor laser array slanted relative to a sub-scanning direction and emitting a plurality of optical beams; a coupling lens converting a shape of each optical beam emitted from the semiconductor laser array; and an aperture with an opening having a size of Am×As, arranged after the coupling lens in a direction in which the optical beam progresses, where Am is a dimension of the opening in a main scanning direction and As is a dimension of the opening in the sub-scanning direction. When a length in the main scanning direction of a contour line defined by 1/e2 strength of a maximum strength of an optical beam at the position of the aperture is Lm, and a length in the sub-scanning direction of the contour line defined by 1/e2 strength of the maximum strength of the optical beam at the position of the aperture is Ls, the following conditional expressions are satisfied: Am<Lm, and??(1) Ls/Lm×0.3<As/Am<Ls/Lm×1.7.

Abstract: A light scanning unit of the present invention can reduce the degree of variation in the quantity of light on a photosensitive body by a scanning position and can reduce a difference in density of an image which occurs at image formation.

Abstract: This invention provides an optical scanning apparatus in which the degree of sensitivity of the bending of a scanning line on a surface to be scanned resulting from the disposition error of a scanning optical system is reduced, whereby good images can always be obtained, and an image forming apparatus using the same. The optical scanning apparatus has deflecting means for deflecting a beam emitted from light source means, and a scanning optical system having a plurality of scanning lenses for directing the beam onto the surface to be scanned, and a first scanning lens La is such that the shape thereof in a main scanning cross section is a meniscus shape having positive refractive power, and satisfies the condition that d1/fm<0.06, where fm is the focal length of the scanning optical system in the main scanning cross section, and d1 is the central thickness of the first scanning lens, and a second scanning lens is such that.

Abstract: Provided is an optical scanning apparatus for optically scanning a surface to be scanned, including: a light source unit that emits a beam modulated according to an image signal; a condenser lens for temporarily focusing the beam emitted from the light source unit into an image in a sub-scanning section in the vicinity of a deflection surface of a light deflector; and a scanning optical system for guiding the beam deflected by the light deflector onto the surface to be scanned, in which: in the sub-scanning section, the beam from the condenser lens is incident at an angle with a normal to the deflection surface; and an scanning optical element constituting the scanning optical system has an optical axis eccentric toward a deflection point side of the deflection surface with respect to a transmission position of a principle ray of the beam in a sub scanning direction.

Abstract: In an optical scanning apparatus having a light source, an incidence optical system for causing a beam emitted from the light source to be incident on a deflector, an imaging optical system for causing the beam reflected and deflected by the deflector to be imaged on a surface to be scanned, and a reflecting portion having a plurality of substantially plane reflecting mirrors disposed in an optical path between the deflector and the surface to be scanned, the reflecting portion includes a reflecting mirror of which the refractive power in a main scanning cross section is of an opposite sign. Provided are an optical scanning apparatus which does not involve structure and work for adjustment, and can obtain stable imaging performance by a simple method even if a plurality of mirrors are disposed, and an image forming apparatus using the same.

Abstract: A vibration mirror is reciprocatively vibrated by an electrostatic force to reflect an incident light beam.

Abstract: An optical scanning apparatus includes an incidence optical system for causing a beam emitted from a light source to be incident on a deflector, and a scanning optical system for causing the beam reflected and deflected by the deflector to be imaged on a surface to be scanned. The scanning optical system has a first lens on the deflector side and a second lens on the surface to be scanned side. The first lens has positive power in the main scanning direction and has negative power in the sub scanning direction. The power of the first lens in the main scanning direction is greater than the power of the second lens in the main scanning direction, and the second lens has positive power in the sub scanning direction.

Abstract: A light-heat conversion in a light-stimulated writing method and associated apparatus include an image recording body having an element, which absorbs an (electromagnetic wave) provided in a surface of a recording body, or in a recording layer formed on an uppermost layer of the recording body having a material exhibiting a thermal changeable character of wettabilty, or in a substrate or an intermediate layer of the recording body. After a liquid is disposed on the recording body by a liquid forming device, light-stimulated writing is carried out, resulting on an enhanced efficiency of light-heat conversion by a light absorbing element.

Abstract: A scanning optical system is configured to include a light source, an anamorphic optical element, a polygonal mirror, and an imaging optical system. The imaging optical system has a scanning lens including a first lens provided on a polygonal mirror side and a second lens provided on a surface side, and a compensation lens provided on the surface side with respect to the scanning lens, the compensation lens compensating for curvature of field. The scanning lens includes at least one convex surface that has a toric surface having a stronger power in the auxiliary scanning direction than in the main scanning direction. One surface of the compensation lens has an anamorphic aspherical surface, which is a surface whose radius of curvature in the auxiliary scanning direction at a point spaced from the optical axis thereof is determined independently from a cross-sectional shape thereof along the main scanning direction.

Abstract: A method and device for managing and controlling a scanning system that incorporates multiple oscillating scanners is provided by the present invention. In accordance with the preferred embodiment, a resonant frequency is determined for each of the scanners. A drive signal for driving the oscillating scanners is generated based upon the determined resonant frequencies. An amplitude adjustment circuit determines the difference between the drive signal frequency and the resonant frequency of each oscillating scanner and adjusts the amplitude of the drive signal provided to that particular oscillating scanner such that scan amplitude of each oscillating scanner is approximately equal. The offset from the resonant frequency is also used to calculate a phase adjustment for the drive signal to insure that the oscillating scanners are operating in tandem.

Abstract: A scanning optical system includes a light source, an anamorphic optical element, a polygonal mirror, and an imaging optical system that converges the beam(s) on a surface to be scanned. The imaging optical system has a scanning lens, and a compensation lens provided on the surface side for compensating for curvature of field. All the surfaces of the scanning lens are rotationally symmetrical, and the compensation lens has an aspherical surface. A cross section of the aspherical surface in the auxiliary scanning direction is asymmetrical with respect to the optical axis thereof, and a SAG amount defining the aspherical surface is expressed by a two-dimensional polynomial.

Abstract: In a light scanning optical system having a first optical system for causing a beam emitted from light source means to be incident on the deflecting surface of a light deflector at a predetermined angle in the sub-scanning cross-section, and a second optical system for imaging the beam reflected and deflected by the light deflector on a surface to be scanned and bringing the deflecting surface of the light deflector and the surface to be scanned into a substantially conjugate relation in the sub-scanning cross-section, when the maximum value and minimum value of the peak intensity in the effective scanning area of a spot imaged on the surface to be scanned by the second optical system are defined as EMAX and EMIN, respectively, to satisfy the condition that 0.8?EMIN/EMAX.

Abstract: Provided are compact, high-definition, optical scanning apparatus and multi-beam scanning apparatus capable of keeping the spot size uniform in the sub-scanning direction throughout the entire, effective scanning area on a surface to be scanned. An optical scanning apparatus has an entrance optical system 11 for guiding light emitted from a light source 1, to a deflector 5, and a scanning optical system 6 for focusing the light reflectively deflected by the deflector, on a surface to be scanned 7. In the optical scanning apparatus, the scanning optical system has a plurality of sagittal asymmetric change surfaces in which curvatures in the sagittal direction change on an asymmetric basis in the meridional direction with respect to the optical axis of the scanning optical system.

Abstract: A lens for optical scanning condenses luminous flux deflected by an optical deflector to a plane to be scanned in a scanning image forming optical system. The lens is made of a plastic material by molding. A reference axis of an N-th order approximating curve of refractive index distribution ?n(x) of the lens is away from a center of a passing area, through which the luminous flux passes in the lens, by equal to or more than 10% of the width of the passing area.

Abstract: Provided is a scanning optical system in which the influence of structural birefringence resulting from a relationship between the arrangement direction of a fine grating structure and polarization planes is reduced to obtain a preferable optical performance, and an image forming apparatus using the scanning optical system. In the scanning optical system, a light flux emitted from a light source unit is deflected by a deflection unit. The light flux deflected by the deflection unit is guided onto a surface to be scanned by a scanning optical unit having a fine structural grating on at least one optical surface. The surface to be scanned is scanned with the light flux. The fine structural grating has a triangular grating in which triangular grating parts are arranged in one dimensional direction.

Abstract: A laser unit, which provides markings on a surface of a continuous strip of metal, includes a laser for generating a beam of laser radiation. The laser unit further includes a lens arrangement for focusing the laser beam onto the surface of the strip, and a beam scanner that effects a controlled deflection of the laser beam in two mutually perpendicular directions. The beam scanner is arranged intermediate the laser and the lens arrangement. The laser unit is operable to provide laser engraved markings at exact locations on the surface when the strip intermittently is in an immobilized condition before being fed into a subsequent processing apparatus, which mechanically shapes the thus-marked strip into marked articles to be included in cans.

Abstract: An optical scanning lens which is used in a scanning and age forming optical system which gathers a light flux deflected by a light deflector in the vicinity of a surface to be scanned. The lens is formed by plastic molding of polyolefin resin, and the following condition is satisfied: 0<|?n(x)?min[?n(x)]|<34×10?5, where ?n(x) denotes a refractive-index distribution existing inside the lens, in a range which the light flux passes through, in the lens, and min[?n(x)] denotes the minimum value of the ?n(x).

Abstract: In bi-directional imaging, such as bi-directional printing, a galvanometric oscillator scans a light beam through a scan path across an imaging window. A controller enables transmission of video data to a modulator when the light beam is positioned for imaging on the imaging window. Video data is transmitted to the modulator when the light beam is traveling in a forward direction or a reverse direction across the imaging window, whereby a modulated light beam is capable of producing an image when traveling in the forward or reverse directions.

Abstract: A multi-beam scanning device includes a light source for emitting a plurality of laser beams, a polygon mirror for deflecting the laser beams so that the laser beams scan across an object surface in a main scanning direction, an f? lens disposed between the polygon mirror and the object surface, and a cylindrical lens that converges each laser beam in a vicinity of the polygon mirror in the auxiliary direction. A mirror is disposed between the light source and the cylindrical lens which deflects the laser beams in the auxiliary scanning direction. The mirror is rotatably supported by a mirror holder such that the traveling direction of the laser beams deflected by the mirror can be adjusted.

Abstract: A light scanning unit of the present invention can reduce the degree of variation in the quantity of light on a photosensitive body by a scanning position and can reduce a difference in density of an image which occurs at image formation.

Abstract: It is an object of this invention to provide a light scanning device capable of suppressing scanning line bending to a low level, which is caused by the arrangement error of a single-element lens serving as an imaging optical element, and an image forming apparatus using the device. In order to achieve the object, according to this invention, an imaging optical system is formed from a single-element lens, and the sectional shapes of the incident and exit surfaces in the main scanning direction are non-arcuated, and the power in the sub scanning direction substantially concentrates on the exit surface. The non-arcuated shape (curvature) of the exit surface in the main scanning direction is so determined as to make the magnification in the sub scanning direction uniform.

Abstract: An optical scanner for an image forming apparatus of the present invention includes a polygonal mirror for steering a scanning beam incident thereto and an optical device located in the vicinity of the polygonal mirror. The polygonal mirror and optical device are supported by a housing. A heat radiation guide adjoins the polygonal mirror and is formed integrally with or separately from the housing. The heat radiation guide has a guide surface inclined relative to the axis of rotation of the polygonal mirror and intersecting a plane virtually formed by a scanning beam.

Abstract: An optical scanning apparatus reduces shading and variations in light intensity and significantly increases light usage during an optical scanning process using a simple construction in which a laser beam from a light source is deflected by a light deflector having a reflective surface and is focused to a spot upon a scanning surface by a scanning lens to thereby perform optical scanning. The light source is arranged to produce a laser beam which includes both P-polarized light and S-polarized light. A direction of polarization of the light source is inclined in a plane perpendicular to the optical axis with respect to both the deflecting direction (the Y-axis direction) and a direction perpendicular to the deflecting direction (Z-axis direction).