Abstract: An optical scanning apparatus for scanning a target surface using a plurality of light beams simultaneously along a first direction of the target surface. The apparatus has a light source having a plurality of light emitting elements; an optical deflector to deflect the plurality of light beams coming from the light source; and a scanning optical system to guide the plurality of light beams deflected by the optical deflector to the target surface. The scanning optical system includes a lens, disposed after the optical deflector, having the strongest power in a second direction perpendicular to the first direction. A plurality of scan lines, corresponding to the plurality of light beams deflected by the optical deflector, intersect or contact each other at an optical face of the lens.

Abstract: An image forming apparatus includes an apparatus main body, a plurality of optical scanning devices, first temperature detectors for detecting the temperatures of the optical scanning devices, a second temperature detector for detecting the temperature of the apparatus main body, a first condition judger, a second condition judger and a temperature adjuster. The temperature adjuster performs a total motor drive process for driving the motors of all the optical scanning devices if a predetermined first condition is satisfied and a predetermined second condition is satisfied. On the other hand, the temperature adjuster drives the motor of the one optical scanning device and does not drive the motors of all the optical scanning devices excluding the one optical scanning device if the first condition is satisfied, but the second condition is not satisfied.

Abstract: In a light source device including an aperture member that regulates a light beam, |(Pap1?Pap2)/Pap2|<|(P1?P2)/P2| is satisfied where P2 is a light intensity of the light beam entering the aperture member at a time t2 when 2 microseconds have passed since current was applied to the laser, P1 is a light intensity of the light beam entering the aperture member at a time t1 when 40 nanoseconds have passed since a light intensity of the light beam entering the aperture member reached 0.1 time the light intensity P2, Pap2 is a light intensity of the light beam output from the aperture member at the time t2, and Pap1 is a light intensity of the light beam output from the aperture member at a time t1? when 40 nanoseconds have passed since a light intensity of the light beam output from the aperture member reached 0.1 time the light intensity Pap2.

Abstract: An optical scanning device including: a light source part that is provided in a resin-molded casing and emits a laser beam; a deflector that is arranged in the casing and deflects and scans the laser beam, the deflector including, a rotary polygon mirror that reflects the laser beam, a driving source that rotates the rotary polygon mirror, and a substrate member; and the casing including, a fixed wall that extends in a direction perpendicular to a mirror surface of the rotary polygon mirror, a first fixing part that is provided to the fixed wall and fixes the light source part, a second fixing part that is provided to the fixed wall and fixes the substrate member, and a reinforcing part that is provided to the fixed wall and extends toward the emission direction so as to continuously connect the first fixing part and the second fixing part.

Abstract: A housing includes a base portion for installation of an optical beam emission unit, a light guiding unit, and a deflection unit, and a cover portion that includes an indented heat emission channel that transmits heat in an inner portion of the housing to a fluid.

Abstract: An optical scanning unit includes a light source including a plurality of light-emitting elements; a light detector to detect a light beam emitted from the light source; a light-flux splitter, angled to the optical axis of the light beam emitted from the light source, having an aperture, a portion of reduced thickness susceptible to warping, a concave face of the warped light-flux splitter as a reflecting face, and a convex face of the warped light-flux splitter opposite the concave face as a non-reflecting face; and a light-flux splitter pressing unit to press the light-flux splitter onto a light-flux splitter holding member without blocking the aperture. Light beam passed the aperture is used as a write-use light flux. The reflecting face reflects a light flux other than the write-use light flux as a monitor-use light flux. The light-flux splitter pressing unit presses a portion of maximum convexity of the non-reflecting face.

Abstract: A scanning optical device that scans a photoreceptor with laser light includes a light source, a light outputting section, and a projection. The laser light from the light source is output through the light outputting section so that the photoreceptor is irradiated with the laser light. The projection projects through a partition wall toward the photoreceptor. The light outputting section is disposed in a position separated from the photoreceptor by the partition wall. The projection contains a polygon motor that rotates a polygon mirror to reflect the laser light.

Abstract: According to one embodiment, an optical scanning device includes plural light sources, a polygon mirror, a first lens, a first reflection mirror, and a second lens. The polygon mirror deflects lights emitted from the plural light sources in a predetermined direction. The first lens allows the lights emitted from the plural light sources and deflected by the polygon mirror to pass. The first reflection mirror reflects the lights passed through the first lens in a direction different from the deflecting direction of the polygon mirror. The second lens receives incidence of the lights reflected by the first reflection mirror from a direction different from an incident direction of the first lens and allows, with one lens, the lights emitted from the plural light sources to pass.

Abstract: An optical scanning apparatus includes a light source, rotational polygonal mirror, correction data calculating unit, modification computing unit, and adjustment unit. The adjustment unit adjusts drive current supplied to the light source using the correction data calculated by the correction data calculating unit when a first of a plurality of modes is selected or using the correction data calculated by the modification computing unit when a second of the plurality of modes is selected.

Abstract: A polygonal mirror, a light scanning unit using the polygonal mirror, and an image forming apparatus. The polygonal mirror is formed of a plastic and includes a plurality of reflection surfaces that are formed in an outer portion of the polygonal mirror and rotate around a rotational axis, and an internal mirror surface that defines a hole, wherein a ratio of an internal diameter d to an outer diameter D satisfies 0.1?d/D?0.3.

Abstract: An optical scanning apparatus has first and second light sources, a deflection scanning device, and first and second scanning optical systems that guide the first and second laser beams deflected for scanning by the deflection scanning device. The first and second scanning optical systems include scanning lenses and a polarization beam splitter arranged in a downstream side of an optical path of the scanning lens, the first scanning optical system including a half-wave plate arranged in the downstream side of the optical path of the scanning lens and in an upstream side of an optical path of the polarization beam splitter, the first laser beam and the second laser beam having different phases by 180 degrees from each other before being incident on the first and second scanning optical systems.

Abstract: According to one embodiment, if it is designated by operation of a control panel that a printed halftone image for test is defective, a number of revolutions of a polygon mirror is finely adjusted by a predetermined rate and a frequency of a serial data signal is finely adjusted by the rate.

Abstract: A housing (30) includes a base portion (30a) for installation of an optical beam emission unit (31), a light guiding unit (35a-39a, 35b-39b), and a deflection unit (32, 33), and a cover portion (30b, 30c) that includes an indented heat emission channel (30b1, 30c1) that transmits heat in an inner portion of the housing (30) to a fluid.

Abstract: A plurality of light sources, a light deflector, and a single scan lens. The light deflector deflects a plurality of light beams emitted from the light sources by a same face for scanning a plurality of to-be-scanned portions simultaneously. The single scan lens receives the light beams from the light deflector and focuses the light beams onto each of the plurality of to-be-scanned portions to scan the to-be-scanned portions simultaneously. The single scan lens is used in common for the light beams, and has one incidence plane and a plurality of exit planes in a sub-scanning direction separately prepared in the sub-scanning direction for each of the to-be-scanned portions. The incidence plane has a refractive power of the lens in the sub-scanning direction decreasing toward peripheral portions in the main scanning direction. The exit planes have positive refractive power in the main and sub-scanning directions.

Abstract: An optical scanning unit includes a rotatable multi-faceted mirror having a plurality of faces reflecting light flux emitted from a light source to scan a scanning area in a main scanning direction. A width of the light flux striking the rotatable multi-faceted mirror is smaller than a length of a face of the rotatable multi-faceted mirror. The entire of light flux striking the rotatable multi-faceted mirror is reflected at a first face when the light flux reflected by the rotatable multi-faceted mirror is directed to the center portion of the scanning area. A part of the light flux striking the rotatable multi-faceted mirror is reflected at the first face while the remaining of the light flux is reflected at a second face when the light flux reflected by the rotatable multi-faceted mirror is directed to a least one of the two end portions of the scanning area.

Abstract: In an image-reader, the first counter is configured to count a first count value based on a first clock. The second counter is configured to count a second count value based on a second clock. The first reading unit is configured to read a first surface of a document sheet based on the first count value. The second reading unit is configured to read a second surface of the document sheet based on the second count value. The second surface is opposite surface of the first surface. When the first count value reaches a prescribed first value, both the first counter value and the second count value are reset.

Abstract: An image forming apparatus includes a correction control unit and a correction amount adjusting unit. The correction control unit performs a phase correction process of changing a drive frequency of a driver for driving and rotating a rotating polygon mirror having a rotational phase difference judged not to coincide by a predetermined correction amount and driving the driver for a period corresponding to a specified clock number by a drive clock signal of the changed drive frequency if a rotational phase difference of another rotating polygon mirror does not coincide with a reference rotational phase difference. The correction amount adjusting unit reduces the predetermined correction amount by a predetermined specified amount and causes the correction control unit to perform the phase correction process again if the rotational phase difference does not coincide with a reference rotational phase difference after the phase correction process is performed.

Abstract: An optical scanner includes a light source including light emitters, an aperture member collimating light beams from the light source, a deflector deflecting the light beams passing through the aperture member, and a scanning optical system condensing the deflected light beams onto a scanned surface to optically scan the surface in a main-scanning direction. The scanning optical system includes a resin scanning system having at least one resin scanning lens. At least one folding mirror/sheet glass is disposed between a scanning lens nearest to the deflector in the resin scanning system and the scanned surface. At least one scanning lens in the resin scanning system has an uneven birefringence distribution with respect to a sub-scanning direction. An optical conjugate image of the aperture member is formed between a lens surface nearest to the deflector in the resin scanning system and a lens surface nearest to the scanned surface with respect to the sub-scanning direction.

Abstract: An image forming apparatus includes: a light source that emits a light beam; a photosensitive member; a brushless motor including a stator where a plurality of coils are placed and a rotor where a plurality of magnets are placed; a rotary polygon mirror, which is rotated by the brushless motor, and which periodically deflects the light beam emitted from the light source to sequentially form scanning lines on the photosensitive member; an energization switching unit that turns on and off energizations of the coils; a voltage detecting unit that outputs a detection signal based on induced voltages that are generated in the coils by rotation of the rotor; and a control unit that controls turning on/off of the energizations by the energization switching unit based on the detection signal.

Abstract: An image forming apparatus includes: a light source; a photosensitive member; a brushless motor including a stator and a rotor; a rotary polygon mirror rotated by the brushless motor; an energization switching unit that turns on/off energizations of the coils; a voltage detecting unit that outputs a detection signal based on induced voltages generated in coils of the stator by rotation of the rotor; and a motor controlling unit that controls the turning on/off of the energizations by the energization switching unit based on the detection signal. In a non-image forming period after one image forming operation, the motor controlling unit performs a low-speed process where the motor controlling unit maintains a rotation speed of the brushless motor at a speed, which is lower than a speed in the image forming operation, and at which the induced voltages are detectable by the voltage detecting unit.

Abstract: An exposure device includes a mirror to reflect light used for exposure of an object, a holder to hold the mirror, an adhesive that bonds the mirror to the holder and elastically deforms, and an adjusting tool that pushes the mirror to change a direction of the mirror.

Abstract: An optical scanning apparatus includes a housing, light source, deflector, imaging lens, reflective mirrors, a synchronization detector and synchronization detection mirror. The housing has a plate to partition the housing. The deflector deflects a light beam emitted from the light source. The imaging lens converts the deflected light beam into a constant speed scanning light beam. The reflective mirrors reflect the constant speed scanning light beam to a photoreceptor. The synchronization detector detects timing for starting scanning of the photoreceptor. The synchronization detection mirror reflects the light beam to the synchronization detector. At least one of the reflective mirrors is disposed midway in a synchronization detection light path extending from the deflector to the synchronization detection mirror. The light beam reflected by the synchronization detection mirror is reflected again by at least one of the reflective mirrors, such that the light beam is guided to the synchronization detector.

Abstract: The present invention is an optical scanning apparatus that is positioned and fixed to a metal frame of an image forming apparatus, in which a rotating polygon mirror being a deflection means and a drive motor rotationally driving the rotating polygon mirror are accommodated inside a housing made of resin. In the present invention, a bearing of the drive motor and a positioning member provided upright to the metal frame are inserted into and fitted with each other from opposite directions in a positioning boss formed in the housing, and the bearing is in contact with the positioning member.

Abstract: The present invention provides an optical scanning device that can suppress irregularity of the rotation of a polygon mirror and an image forming apparatus that is disposed with this optical scanning device. The optical scanning device includes: a rotating polygon mirror that rotates and deflects light that has been emitted from a light source; and a plate member that covers one surface of surfaces intersecting an axial direction of a rotating shaft of the rotating polygon mirror, wherein a projecting portion that projects in the axial direction of the rotating shaft away from the rotating polygon mirror is disposed in the plate member.

Abstract: A light scanning apparatus including: a light source to emit a laser beam; a light source driving unit to turn on and off the light source according to image data and a pixel clock; a rotary polygon mirror to deflect the light beam; a motor to rotationally drive the rotary polygon mirror; and a control unit to control a rotary speed of the motor to generate an acceleration control signal for accelerating the rotary speed and a deceleration control signal for decelerating the rotary speed, wherein for the acceleration control signal, the driving unit corrects the frequency of the pixel clock to be higher than the frequency, which is before the acceleration control, and for the deceleration control signal, the driving unit corrects the frequency of the pixel clock to be lower than the frequency, which is before the deceleration control.

Abstract: An optical scanner used for an image-forming device to form a color image includes a plurality of photosensitive drums for superimposing a developer image formed on each of the plurality of photosensitive drums. The optical scanner includes a casing, a plurality of light sources, a deflector, an optical system, and a storage device. The plurality of light sources is provided in a one-to-one correspondence with the plurality of photosensitive drums. Each of the plurality of light source emits a laser beam. The deflector is provided in the casing for deflecting the laser beam. The optical system is provided in the casing for guiding the deflected laser beam to a corresponding one of the plurality of photosensitive drums to make the laser beam scan the corresponding one of the plurality of photosensitive drums. The storage device stores a characteristic related to the laser beam scanning the corresponding one of the photosensitive drums.

Abstract: An optical scanner, which scans at least one scanned face by a light beam, includes a light source having a plurality of light emitting points, an optical system before a light deflector configured to form a plurality of light beams from the light source, a light deflector configured to deflect the light beams via the optical system before a light deflector and scan the deflected light beams, and a scanning optical system configured to focus on the scanned face the light beams deflected and scanned by a deflection face of the light deflector, the optical system before a light deflector including a first optical element having a negative power at least in a deflecting and scanning vertical direction, a second optical element having a power only in a deflecting and scanning direction and a third optical element having a power only in the deflecting and scanning vertical direction.

Abstract: An image forming apparatus including; an exposure section provided with, a light emitting element, a polygon mirror to receive light beams from the light emitting element, and to expose an image carrier using light beam via the polygon mirror based on image data; an image processing section to adjust image magnification by image processing of the image data; and, a control section configured to select at least either of a first magnification adjustment to change a rotation speed of the polygon mirror and a second magnification adjustment to carry out image processing of the image data by the image processing section, based on comparison results between a paper interval time during recording paper conveyance in image formation and the first magnification adjustment time required to stabilize polygon mirror rotation in the first magnification adjustment, when adjusting image magnification with respect to recording paper.

Abstract: An optical scanning apparatus includes a housing, light deflector, first optical system and reinforcement member. The housing includes a peripheral wall and a partitioning portion to divide an inner side of the peripheral wall into first and second portion. The partitioning portion includes a first hole to cause the first portion to communicate with the second portion to form an optical path. The light deflector mounted in the first portion has a rotatable polygon mirror to perform deflection scanning of scanning light beams emitted from light sources and a drive unit to drive the rotatable polygon mirror to rotate. The first optical system mounted at least in the first portion causes the scanning light beams reflected from the rotatable polygon mirror to return towards the first hole. The reinforcement member mounted on a surface facing at least the second portion on the partitioning portion reinforces the housing.

Abstract: A 2-D scanning system uses a fast-rotating raster-polygon as a single scanning component to produce straight scan lines over a 2-D image surface. An approach angle of incident light beams to the raster-polygon is selected to minimize pin-cushion distortion of scan lines introduced by polygon scanning on the image surface, and a tilt angle of the rotational axis of the raster-polygon is selected to position said polygon-scanning distortion symmetrically on the image surface. In addition, scan optics are configured to generate a predetermined amount of barrel distortion of scan lines on the image surface to compensate for pin-cushion distortion introduced by polygon scanning.

Abstract: An image forming apparatus includes a scanner motor and a rotary polygonal mirror which is driven by the scanner motor to rotate, and reflects a modulated beam emitted from a light source by a plurality of reflection surfaces. The image forming apparatus includes a rotation and carrier unit which, while rotating, carries an image formed on the basis of a laser beam reflected by the rotary polygonal mirror, a speed detection unit which detects a rotation speed of the rotation and carrier unit. The image forming apparatus includes a tracking characteristic detection unit which detects a tracking delay of the scanner motor from a target rotation speed and a control unit which controls, on the basis of the rotation speed detected by the speed detection unit and a tracking characteristic detected by the tracking characteristic detection unit, a rotation speed of the scanner motor that drives the rotary polygonal mirror.

Abstract: An scanning optical apparatus of present invention converts plural light beams emitted from corresponding light source units by a light beam conversion unit, deflectively scans by a deflection unit, focuses by an imaging optical unit onto corresponding scanned surfaces. At least two of light source units are arranged along a direction perpendicular to the direction in which the light beams are emitted. The light beam conversion unit includes plural light beam conversion elements that reflect the light beams emitted in the same direction from the light source units to deflect the light beams in the same direction. Each of the light beam conversion elements has at least one reflecting surface having a power and at least one diffracting surface having a power, and has different powers with respect to the main scanning direction and with respect to the sub scanning direction.

Abstract: An image forming apparatus including a black developer with increased capacity. The image forming apparatus includes optical scanners, where the optical scanners have the same focusing distance from the light source to the photo conductor, and the light reflecting unit of one of the optical scanners is arranged at a position different from the light reflecting unit of another optical scanner, such that intervals between the developers vary. Accordingly, although developers of the same type are used, the capacity of the black developer, which is most frequently used, may be easily increased by arranging the relative positions of the developers.

Abstract: A scanning optical device that scans a photoreceptor with laser light includes a light source, a light outputting section, and a projection. The laser light from the light source is output through the light outputting section so that the photoreceptor is irradiated with the laser light. The projection projects through a partition wall toward the photoreceptor. The light outputting section is disposed in a position separated from the photoreceptor by the partition wall. The projection contains a polygon motor that rotates a polygon mirror to reflect the laser light.

Abstract: An optical scanning apparatus, including an incident system that allows a beam from the light source to enter to deflector; and an imaging system that images the beam deflected by the deflector on a scanning surface, in which the incident system includes a first and second systems, the first system includes first and second elements each having a positive power with rotational symmetry, the light source is positioned at a shorter distance from the front focus position of the first element, the first element is formed integrally as a unit, powers of the second element and the first system, magnifications within main and sub-scanning sections of entire system, and focus movement within the main and sub-scanning sections on the scanning surface when the second element is moved in the optical axis direction are appropriately set.

Abstract: An optical scanning device includes a first optical a light source that has a plurality of luminous points; a first optical system that shapes a plurality of beams of light; a rotary polygon mirror an optical scanning system that causes the beams of light deflected to form images on a surface to be scanned, wherein ? is assumed to be half of an angle formed between the optical axis of the first optical system and the optical axis of the optical scanning system within the deflecting/scanning surface, ? is assumed to be a distance between an intersection dc and an intersection hh, wherein ? is set to be zero or a negative value, given that ? is defined positive when the intersection dc is present on the optical-scanning side of the intersection hh.

Abstract: An image forming apparatus includes a light source, a polygon mirror, and a plurality of photosensitive elements. The polygon mirror has a plurality of reflection surfaces that reflect a light beam at different angles. The light beams deflected by the reflection surfaces travel along different optical paths and impinge on different photosensitive elements. A light-beam control unit controls emission of the light beam from the light source depending on a distance between the deflecting unit and the photosensitive elements thereby performing an f? correction of the light beam.

Abstract: An image forming apparatus includes: a light source that emits a light beam; a photosensitive member; a driving motor; a rotary polygon mirror, which is rotated by the driving motor, and which periodically deflects the light beam emitted from the light source to sequentially form scanning lines on the photosensitive member; a position detecting unit, which detects a rotational position of the driving motor, and which outputs a detection signal; a sensor, which receives the light beam deflected by the rotary polygon mirror, and which outputs a light receiving signal; a detecting unit, which receives the detection signal and the light receiving signal, and which detects a rotation direction of the driving motor based on a timing pattern of a detection of the rotational position of the driving motor and a reception of the light beam by the sensor.

Abstract: A disclosed light source apparatus includes a light source including multiple light emitting devices; an optical element configured to transmit light emitted from the light source; a tube configured to hold the optical element; and a tube holder configured to fix the tube by holding an end of the tube close to the light source or by holding the end of the tube on the light emission side away from the light source. A positional displacement preventing member is provided at the other end of the tube on a light emission side away from the light source in such a manner as to be slidable on the tube in the direction of an optical axis and prevent positional displacement of the tube in all directions perpendicular to the optical axis.

Abstract: An image forming apparatus includes: a plurality of optical systems, each of which includes a light-beam generating unit that generates a light beam, a rotary polygon mirror that deflects the light beam so as to scan a image carrier, and a light-beam detecting unit that detects the light beam deflected for scanning at a predetermined position on a scanning path by rotationally driving the rotary polygon mirror; a time-difference measuring unit that measures a time difference between light-beam detecting signals; a generation-timing determining unit that determines time of generation timing for generating a start signal that designates a start of an image writing operation so that the generation timing does not overlap another timing when each of the light-beam detecting signals is output from the corresponding time-difference measuring unit; and a start-signal generating unit that generates the start signal based on the time for the generation timing.

Abstract: Systems and methods for reducing the degradation of image quality due to banding in an image processing system by detection of both integrated intensity and peak intensity of a laser beam reflected from the polygon mirror facet(s) of a motor polygon assembly. A banding detector is adapted to enable measurement of peak intensity and integrated intensity of the laser beam(s) reflected from the polygon mirror facet(s). Polygon facet induced banding can be determined from the measurements and can be used for sorting/manufacturing raster output scanners and/or compensating for the induced banding.

Abstract: A scanning optical device includes a deflector for scanningly deflecting a plurality of light beams from a plurality of light sources, and an imaging optical system for imaging the light beams upon a plurality of scan surfaces to be scanned, wherein at least one piece of reflecting element is provided at each of a plurality of light paths extending from the deflector toward the scan surfaces.

Abstract: An optical scanning apparatus effectively blocks undesirable-light generated in opposed scanning units, and forms high-quality image with simple configuration. The apparatus includes two scanning units disposed with a polygon mirror therebetween, each scanning unit including: an incident optical system guiding a beam from a light source to the polygon mirror; and an imaging optical system including an imaging optical element to cause the deflected beam form an image on a scanning surface. One of the scanning units includes a member to block an undesirable light reflected on optical surfaces of the imaging optical element of the other scanning unit and traveling toward the scanning surface of said one scanning unit. rp<L?A/2 is satisfied, where rp denotes circumcircle radius of polygon mirror; L denotes distance from rotational center of polygon mirror to the blocking member of said one scanning unit, and A denotes length of polygon mirror drive circuit substrate.

Abstract: An exposure unit which exposes photoconductive drums having rotary axes thereof arranged parallel to each other on a single plane by light beams, includes one or more polygon mirrors each having a plurality of reflection surfaces, where the one or more polygon mirrors rotate about a common rotary axis. Each light beam is deflected by the one or more polygon mirrors and scans the surface of a corresponding photoconductive drum. The common rotary axis is separated from the rotary axes of the photoconductive drums by identical distances along respective normals which are perpendicular to both the common rotary axis and the rotary axes of the photoconductive drums.

Abstract: An optical scanning device includes an input optical system having an input optical element, for projecting a light beam from a light source device onto a deflecting surface of an optical deflector, and an imaging optical system having an imaging optical element, for imaging the light beam scanningly deflected by the deflecting surface of the optical deflector, on a surface to be scanned, wherein the light beam is obliquely incident on the deflecting surface in a sub-scan section, wherein the imaging optical element has at least one optical surface which is decentered in the sub-scan section, wherein the input optical element has at least one optical surface having an asymmetric and aspherical surface shape, wherein the input optical element has a thickness dm1 in the sub-scan section and at a position where a first marginal light ray of the light beam passing through the input optical system, which first marginal light ray is closer to an optical reference axis than the principal ray of that light beam is, p

Abstract: An optical scanning device includes an optical housing in which a polygon mirror that is rotated by a motor is accommodated and an air inlet that includes a filter. An airflow guiding member is arranged at a position opposite to a surface of the polygon mirror on the air inlet side. An air inducing path is provided, which includes a first flowing path and a second flowing path. The first flowing path includes a first end linked to the air inlet and a second end arranged close to a mirror surface of the polygon mirror. The second flowing path is formed with a surface of the airflow guiding member on an opposite side of the air inlet and a top surface of the polygon mirror.

Abstract: A scanning optical device including a plurality of light source devices 1a-1d, a light beam converting system 3 for converting the light focus state of the plurality of light beams emitted from light emitting members of the light source devices, a deflecting member 5 for scanningly deflecting the light beam from the light beam converting system, and imaging optical members 6a-6d for imaging the light beam from the deflecting member upon scan surfaces 8a-8d corresponding to the light beams, respectively, wherein the light beam converting system is comprised of a plurality of optical elements 3a-3d formed integrally and each converting the light focus state of associated one of the light beams from the light source devices, and wherein the light source devices are fixed to a holding member 12 while the positions with respect to the associated optical elements are adjusted.

Abstract: An image forming apparatus performs multi-color image formation using a plurality of scanning type optical devices which deflect and scan an optical beam using a rotating polygonal mirror. The image forming apparatus includes, for example, a detecting unit that detects a phase of rotating speed unevenness of rotating polygonal mirrors respectively provided in the plurality of scanning type optical devices, and an adjusting unit that adjusts, based on a phase of rotating speed unevenness detected for each rotating polygonal mirror, the rotating speed of each rotating polygonal mirror to reduce the phase differences between the phases.

Abstract: An optical scanning apparatus includes a light source configured to emit a light beam, a rotational polygonal mirror configured to deflect and scan the light beam emitted from the light source, a drive unit configured to drive the rotational polygonal mirror to rotate, an optical member configured to guide the light beam with the scanning rotational polygonal mirror to a member to be scanned, a storage member configured to accommodate the rotational polygonal mirror and the optical member therewithin, and a wall configured to partition a space inside the storage member into a first space in which the rotational polygonal mirror is installed and a second space in which the optical member is installed, wherein the wall has an opening through which air can pass, and the opening is configured to pass the light beam reflected by the scanning rotational polygonal mirror, and the wall has a vent which is different from the opening and configured to send at least a part of the air that has passed through the opening,

Abstract: In an optical scanning device, when pixel density is taken to be n, number of the light beams is taken to be b, and number of the deflection surfaces of a deflecting unit is taken to be p, a spatial frequency S denoted by S=1/(1/(25.4/n×b×p) is within a range of a spatial frequency characteristic for a visual perception system of a high relative luminous efficiency. When spacing between ends in a sub-scanning direction of a scanning line formed by one scan by the deflection unit is taken to be L1, and spacing between all progressive scanning lines at the surface to be scanned is taken to be L2, then L1>(k?1)×L2 is satisfied, where k is a total number of light emitting points of a light source.