Abstract: An optical scanning device includes a vertical cavity surface emitting laser, a driving unit that controls modulation driving, a coupling optical system that couples a beam, an aperture that is configured to define a beam spot diameter, a deflecting unit that deflects a laser beam incoming, and a scanning optical system that guides the laser beam, wherein the driving unit controls so as to satisfy conditions 1 and 2 below: condition 1: P1>P100, condition 2: Wm<Ws, where P1 is an amount of light at a time after a period T1 corresponding to a minimum pixel unit has elapsed since beginning of light emission, P100 is an amount of light at a time after a time period of 100×T1 has elapsed since the beginning of light emission, Wm is a static beam spot diameter in a main-scanning direction, and Ws is a static beam spot diameter in a sub-scanning direction.

Abstract: An optical beam scanning device includes a polygon mirror 80 in which tilt angles with respect to a rotation axis of the polygon mirror 80 of respective plural reflecting surfaces are set to angles corresponding to photoconductive members associated with the respective reflecting surfaces, a post-deflection optical system A1 that guides light beams reflected and deflected by the respective plural reflecting surfaces in the polygon mirror 80 to the photoconductive surfaces of the photoconductive members corresponding to the respective reflecting surfaces, and a pre-deflection optical system 7a that shapes the light from the light source to be a light beam of a predetermined sectional shape and guides the light beam to the polygon mirror 80, the pre-deflection optical system 7a guiding the light from the light source to the polygon mirror 80 through an optical path that passes, in the main scanning direction, on an optical axis of the post-deflection optical system A1 and passes, in the sub-scanning direction,

Abstract: An optical scanner forms an electrostatic latent image on a photosensitive member by scanning the photosensitive member with a light beam. The optical scanner includes: an incident optical system which at least comprises: a light beam emission device configured to emit a light beam; and a cylindrical lens configured to condense the light beam emitted from the light beam emission device, and a scanning optical system which at least comprises: a light deflecting device configured to reflect the light beam having passed through the cylindrical lens to deflect the light beam in a main scanning direction for scanning the photosensitive member; and a scanning lens configured to focus the light beam deflected by the light deflecting device on the photosensitive member to form an electrostatic latent image thereon. The incident optical system and the scanning optical system are divided by a light shielding wall.

Abstract: An image forming apparatus includes a plurality of image carriers and an optical writing device including light sources that emit light beams of different wavelengths, a deflector that deflects the light beams emitted from the light sources and synthesized on an identical axis in a sub-scanning direction, a first beam separator, a second beam separator, a first imaging device, and a second imaging device. The first beam separator and the second beam separator are located between the first imaging device and the second imaging device and transmit or reflect the light beams according to travel directions or wavelengths thereof. One of the targets is scanned with the light beam transmitted through the second beam separator. Another target is scanned with the light beam reflected by the second and first beam separators. The first and second imaging devices narrow the beams in the main scanning direction and the sub-scanning direction, respectively.

Abstract: An optical scanning device includes a light source, a deflector, and an image-forming optical system. The deflector includes a deflecting surface for deflecting light beams in a main scanning direction. The image-forming optical system includes two relay lenses having a positive power in the main scanning direction. The relay lenses cause main light beams of light beams emitted from the light source to cross near the deflecting surface in the main scanning direction.

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 image forming apparatus, includes: a latent image carrier whose surface includes an effective image region spanning across a predetermined width in a main scanning direction and is driven in a sub scanning direction approximately orthogonal to the main scanning direction; a latent image former which has a light source and a deflection mirror oscillating, and deflects a light beam from the light source using the deflection mirror so as to scan the effective image region with the deflected light beam; and a scanning mode controller which switches selectively between a single-side scanning mode and a double-side scanning mode, the single-side scanning mode being a mode in which the light beam is scanned only in a first direction included in the main scanning direction, the double-side scanning mode being a mode in which the light beam is scanned in both the first direction and a second direction opposite to the first direction, wherein a condition to form latent images on the latent image carrier in the singl

Abstract: Positioning displacement characteristics of each of scanning beams are obtained in advance. The positioning displacement characteristics is indicative of a relation between temperature and a displacement amount by which each of the scanning beams is displaced in a sub-scanning direction. A displacement control is performed based on the positioning displacement characteristics by shifting the positioning displacement characteristics in a direction opposite to that of a trend of the positioning displacement characteristics within a pixel pitch.

Abstract: The apparatus is adapted to deflect a light beam from a laser light source for each of the color components by means of a deflection mirror surface which oscillates, thereby making the light beam reciprocally scan in a main scanning direction. In this apparatus, however, only a light beam SL which scans in a first direction (+X) of the main scanning direction is irradiated in an effective image region on a photosensitive member, so as to form a latent image thereon. The resultant latent image is developed to form a toner image. Since image formation is performed using only the light beam SL which scans in the first direction (+X), the images may be formed at the consistent density irrespective of the image types. Furthermore, the scanning directions of the light beams SL for all the color components are uniformly defined to be the first direction (+X), so that the toner images of the respective colors may maintain the consistent density.

Abstract: A disclosed vertical cavity surface emitting laser device emits light orthogonally in relation to a substrate and includes a resonator structure including an active layer; and semiconductor multilayer reflectors disposed in such a manner as to sandwich the resonator structure between them and including a confinement structure which confines an injected current and transverse modes of oscillation light at the same time. The confinement structure has an oxidized region which surrounds a current passage region. The oxidized region is formed by oxidizing a part of a selective oxidation layer which includes aluminum and includes at least an oxide. The selective oxidation layer is at least 25 nm in thickness. The semiconductor multilayer reflectors include an optical confinement reducing section which reduces optical confinement in a transverse direction. The optical confinement reducing section is disposed on the substrate side in relation to the resonator structure.

Abstract: A disclosed optical path switching device includes a polarization bistable VCSEL that emits a beam having a rising polarization plane, a laser light source configured to emit a beam having a polarization plane orthogonal to the rising polarization plane, and an optical path switching unit configured to switch an optical path of the beam emitted from the polarization bistable VCSEL by switching the angle of the rising polarization plane of the beam emitted from the polarization bistable VCSEL. The beam emitted from the polarization bistable VCSEL is incident on an entrance window of the optical path switching unit, and the beam emitted from the laser light source is incident on an exit window of the polarization bistable VCSEL.

Abstract: A first beam separation device is arranged either to allow the light beams to enter and pass or to reflect the light beams in accordance with a direction of entrance of the light beams. A second beam separation device is provided either to allow or to reflect the light beams having passed through the first beam separation device in accordance a wavelength thereof. The light beam passing through the second beam separation device scans one of plural scan objectives and the light beam reflected by the second beam separation device is further reflected by the first beam separation device and then scans the other one of the plural scan objectives. A first imaging device is provided to correct a f-theta (f?) performance and a curvature of an imaging plane to enable the light beams to scan the plural scan objectives at a constant speed. The first imaging device is integral with the first beam separation device.

Abstract: An optical scanning device includes four light sources, a pre-deflector optical system, a polygon mirror, an optical scanning system, etc. The optical scanning system includes deflector-side scanning lenses made of glass, imaging-surface-side scanning lenses made of resin, polarized light splitters, and reflecting mirrors. The deflector-side scanning lenses, the imaging-surface-side scanning lenses, the polarized light splitters, and the reflecting mirrors are arranged in this order on an optical path of light going from the polygon mirror toward drum-shaped photosensitive elements.

Abstract: An optical scanning apparatus includes light source units; a deflecting unit, incident optical systems provided so as to correspond to the light source units, and at least one synchronous detection optical system that controls a timing at which the light beams form images on the surfaces to be scanned. The synchronous detection optical system includes a synchronous detection element, at least one optical path changing unit, and at least one synchronous detection optical element. The synchronous detection element is attached to a circuit substrate of the light source unit arranged to oppose the light source unit that emits a light beam used for synchronous detection, with the deflecting unit therebetween. The synchronous detection optical element and the synchronous detection element are arranged to oppose each other with respect to a line perpendicular to lines connecting a deflection axis of the deflecting unit and optical axes of the imaging optical systems.

Abstract: An image forming apparatus having improved arrangement of photosensitive members and configuration of a light scanning device to enable size reduction is described. The image forming apparatus includes a plurality of photosensitive members, a light scanning device to irradiate light beams to the plurality of photosensitive members, so as to form electrostatic latent images on the photosensitive members, a plurality of developers to supply a developing agent to the photosensitive members, so as to form visible images on the photosensitive members, and a transfer drum disposed in contact with the photosensitive members and used to transfer the visible images such that the visible images overlap one another. Scanning lines, which are formed on the plurality of photosensitive members, respectively, by the light scanning device, are arranged in at least two different planes.

Abstract: The present invention uses a pattern that enables image quality maintaining control to be performed at a resolution lower than that used for a normal image forming process. Thus, during an initial operation upon power-on, the image quality maintaining control is performed at the resolution lower than that used for the normal image forming process.

Abstract: An optical scanning device in which an optical deflector scanningly deflects a light beam emitted from a light source and in which an imaging optical system images the scanningly deflected light beam onto a scan surface. The imaging optical system includes a transmission type imaging optical element and a reflection type optical element, which are disposed in this order from the optical deflector. The reflection type optical element reflects the scanningly deflected light beam in an off-normal light path towards the scan surface. To avoid interference with the off-normal path, a contour central line of the transmission type imaging optical element is positioned at one side of a principal ray of the light beam incident on the transmission type imaging optical element, which side is remote from the off-normal light path reflected by the reflection type optical element.

Abstract: An image forming apparatus is configured, in performing changing of a rotation speed of a scanner motor and forming of an image density adjustment patch in the same page interval, to change the rotation speed of the scanner motor before forming the image density adjustment patch.

Abstract: In a bi-directionally scanning electrophotographic (EP) device, methods and apparatus include storing alignment information. In one aspect, pre-characterization parameters of the EP device are stored in memory, such as NVRAM, resistant to the removal of power. In another, actual parameters of the EP device are learned during calibration and stored in the same memory. A controller has local or remote access to the memory and makes comparisons of the pre-characterized and learned parameters to implement corrections. Especially, scan alignment corrections are implemented to alter future scanning of scan lines of latent images on a photoconductor whereby the scan lines are formed in alternating directions. Certain contemplated parameters include, but are not limited to, a scan detect to print distance from a sensor to the start of imaging, temperature, pressure, a scanning mechanism drive signal parameter, such as pulse width, or sensor delay information.

Abstract: Methods and apparatus include improving print quality of a bi-directionally scanning electrophotographic (EP) device, such as a laser printer or copy machine, according to temperature. A moving galvanometer or oscillator reflects a laser beam to create forward and reverse scan lines of a latent image. During use, the actual ambient temperature is obtained and used make corrections to improve print quality, such as by producing the latent image with a signal altered from an image data input signal to help ensure proper alignment of the forward and reverse scan lines.

Abstract: An image-forming device includes: a housing; an endless belt; a plurality of process units; and a plurality of scanner units. Each scanner unit and each process unit are inclined obliquely to a vertical direction. At least a part of each process unit is inserted into and removed from the housing in an obliquely inclined direction.

Abstract: An imaging lens assembly includes a mount which comprises a mount adhering portion on which a light curable adhesive is applied, an imaging lens which comprises a lens portion, and a supporting portion to extend from the lens portion, and a holder coupled to the mount adhering portion by the light curable adhesive, and to support the supporting portion.

Abstract: Methods and apparatus include improving print quality of a bi-directionally scanning electrophotographic (EP) device, such as a laser printer or copy machine, according to ambient pressure in which operated. A moving galvanometer or oscillator reflects a laser beam to create scan lines of a latent image in opposite directions. A damping of the motion occurs per air density implicated by temperature and pressure, where the pressure changes occurring especially from altitude changes. During use, a drive signal, such as a pulse train, moves the galvanometer or oscillator at or near its resonant frequency. Based on a parameter of the drive signal, such as pulse width, the ambient pressure can be made known. In general, a high-pressure environment requires a relatively longer pulse width to resonate the galvanometer or oscillator in comparison to a shorter pulse width for a low-pressure environment. Corrections to print quality stem from the determined ambient pressure.

Abstract: An optical scanner includes a light source, a polygon mirror, an optical member, a casing, and an exit hole cover. The light source emits a light beam. The polygon mirror rotates and deflects the light beam to be scanned in a scanning direction. The optical member focuses the light beam deflected by the polygon mirror onto a scanning target. The casing houses the polygon mirror and the optical member and includes a first wall portion having a wall inner surface opposing the polygon mirror and the optical member and a wall outer surface opposing the scanning target. The first wall portion is formed with an exit hole through which the light beam is irradiated toward the scanning target. The exit hole cover is formed of a light transmissible member and is disposed on the wall outer surface to cover the exit hole.

Abstract: An image-forming device has cylindrical image-carrying members, and an optical scanning unit. The cylindrical image-carrying members are in a main casing for rotating about respective rotational axes which are parallel to one another and juxtaposed in a single direction. The optical scanning unit is in the main casing and has laser generators, a rotatable polygon mirror, mirrors, and lenses. The laser generators have a one-to-one relationship to the image-carrying members to emit laser beams. The rotatable polygon mirror deflects the respective laser beams to scan the respective image-carrying members. The mirrors have a one-to-one relationship to the image-carrying members to guide the respective laser beams along respective optical paths to the respective image-carrying members. The lenses have a one-to-one relationship to the plurality of image-carrying members provided in the respective optical paths and between the respective mirrors and the respective image-carrying members.

Abstract: A disclosed optical scanning device includes: a light source unit having plural luminous sources; a light source driving unit modulating each luminous source in accordance with pixel information; an oscillating mirror supported on a twist beam as a rotation shaft, the oscillating mirror collectively deflecting light beams from the luminous sources and performing reciprocating scanning on a surface to be scanned; an imaging optical system imaging the light beams from the luminous sources on the surface to be scanned; an oscillating mirror driving unit setting a scanning frequency f in accordance with a resonance frequency of the oscillating mirror; and a pitch adjustment unit adjusting beam spot intervals p in a sub-scanning direction in accordance with the scanning frequency f of the oscillating mirror that has been set.

Abstract: In an optical scanning device including a vertical cavity surface emitting laser (VCSEL), an optical scanning device controls so as to satisfy P1<P100 and Wm>Ws, where P1 is light intensity obtained when a period of time corresponding to a minimum pixel unit (referred to as “T1”) has elapsed after start of illumination; P100 is light intensity obtained when a period of time 100 T1 has elapsed after the start of illumination; Wm is the static beam spot diameter in the main-scanning direction; and Ws is the static beam spot diameter in the sub-scanning direction.

Abstract: An optical beam scanning device includes a polygon mirror 80 in which tilt angles with respect to a rotation axis of the polygon mirror 80 of respective plural reflecting surfaces are set to angles corresponding to photoconductive members associated with the respective reflecting surfaces, a post-deflection optical system A1 that guides light beams reflected and deflected by the respective plural reflecting surfaces in the polygon mirror 80 to the photoconductive surfaces of the photoconductive members corresponding to the respective reflecting surfaces, and a pre-deflection optical system 7a that shapes the light from the light source to be a light beam of a predetermined sectional shape and guides the light beam to the polygon mirror 80, the pre-deflection optical system 7a guiding the light from the light source to the polygon mirror 80 through an optical path that passes, in the main scanning direction, on an optical axis of the post-deflection optical system A1 and passes, in the sub-scanning direction,

Abstract: A deflector includes a vibrating mirror supported by a torsion beam provided as a rotational axis and reciprocally scanning a beam from a light emitting source; and a rotational part configured to give a rotational torque to the vibrating mirror for making oscillation. The rotational part generates the rotational torque along one side separated from the rotational axis by length R in a direction perpendicular to the rotational axis. The vibration mirror has relationships of R<r,D>d,and D?d·(r/R)^2 where width in a direction perpendicular to the rotational axis of a mirror part that is a part of the vibrating mirror is 2r; width in a direction parallel with the rotational axis of the mirror part is d; and width of the separated one side causing generation of the rotational torque is D.

Abstract: An image forming apparatus includes an electrostatic latent image carrier, and an optical writing device including at least one light source, at least one aperture, at least one light shield, a light deflector, an image forming lens, and a housing. The aperture adjusts a light beam generated by the light source into a reference shape. The light shield shields an optical path formed between the light source and the aperture by the light beam. The light deflector deflects the light beam to scan in a main scanning direction. The image forming lens focuses the deflected light beam to scan on the surface of the electrostatic latent image carrier to form an electrostatic latent image on the surface of the electrostatic latent image carrier. The housing contains the light source, the light deflector, and the image forming lens. The housing is integrally molded with the aperture and the light shield.

Abstract: An image forming apparatus provided with an optical beam scanning apparatus according to the invention includes a semiconductor laser device, a pre-deflection optical system, a polygon mirror, and a post-deflection optical system, wherein at least one imaging lens for imaging the luminous flux is provided in the post-deflection optical system includes; at least one projection on a vertical surface to a sub-scanning direction axis is provided in the imaging lens; and at least one positioning member having an engaging groove into which the projection is interfitted and which is engaged in a concave-convex shape is provided in the housing unit of the optical beam scanning apparatus. In accordance with an image forming apparatus according to the invention, in a scanning optical system using an imaging lens or an imaging mirror, influences against optical characteristics following an environmental fluctuation or a change with time can be reduced.

Abstract: A scanning optical apparatus includes a light source, a deflecting element for deflecting a beam of light emitted from the light source, an optical device for causing the beam of light emitted from the light source to be imaged into a linear shape long in the main scanning direction on the deflecting surface of the deflecting element. The optical device is comprised of a first optical element and a second optical element, and a third optical element for causing the beam of light deflected by the deflecting element to be imaged into a spot-like shape on a surface to be scanned. The third optical element includes a single lens, the opposite lens surfaces of which both include a toric surface of an aspherical surface shape in the main scanning plane, the curvatures of the opposite lens surfaces in the sub scanning plane being continuously varied from the on-axis toward the off-axis in the effective portion of the lens.

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 optical writing device includes a dichroic mirror and a deflection beam splitter. The dichroic mirror causes a light beam to pass therethrough or reflect depending on the wavelengths of the light beam. The deflection beam splitter causes a light beam to pass therethrough or reflect depending on a direction from which the light beam is received.

Abstract: An optical beam scanning apparatus according to the present invention includes: a light source; a pre-deflection optical system; a light deflecting device; a post-deflection optical system configured to include at least one or plural second optical elements, which act on light beams of all color components, and plural third optical elements, which respectively act on the light beam of each of the color components, and focus the light beams scanned by the light deflecting device on the scanning object; and a position adjusting mechanism configured to adjust the positions of the third optical elements according to incident directions of the light beams made incident on the third optical elements. Consequently, according to the present invention, it is possible to suitably adjust optical elements included in a post-deflection optical system in which individual focusing lenses are provided for respective color components.

Abstract: To provide an image forming apparatus suppressing color slippage without using a mirror with high flatness, when a reflective surface of the mirror used in an optical system of, for example, yellow is formed in a completely flat surface, and a curvature R of the reflective surface of the mirror used in the optical system of magenta is +75 m, a deviation of a scanning position exceeds 100 ?m at maximum, resulting in accentuating the color slippage. Meanwhile, when the mirror of yellow is replaced with the mirror having the curvature R of +300 m, the slippage can be suppressed to 100 ?m or less. Therefore, each mirror is selected, so that the curvature of each mirror becomes all positive or all negative. Thus, the deviation of the scanning position is in the same direction of laser beams L of each color, and the slippage can be prevented.

Abstract: A technique is provided which enables proper correction of optical characteristics in accordance with change in ambient temperature. An optical beam scanning device capable of causing a luminous flux from a light source to scan a photoconductive surface of each of plural photoconductors in a main scanning direction, includes: a polygon mirror 80 which reflects and deflects an incident luminous flux by plural reflection surfaces arrayed in a direction of rotation, and thereby causes the incident luminous flux to scan in the main scanning direction; and a post-deflection optical system A which includes plural optical devices and which guides the luminous flux reflected and deflected by each of the plural reflection surfaces in the polygon mirror 80, to a photoconductive surface of a photoconductor to which the luminous flux should be guided.

Abstract: An image forming apparatus that previously rotates a polygonal mirror drive motor before starting a job and forms a latent image by using an optical scanning unit including the polygonal mirror drive motor is provided. The image forming apparatus includes a control unit configured to perform control such that, in the determination of the presence or absence of each of color toners before a previous rotation is started, if it is determined that any one of the color toners is absent, only the polygonal mirror drive motor corresponding to a black toner is previously rotated.

Abstract: An optical scanning apparatus includes a light source, a light source driving unit that turns on the light source according to image information, a deflector that deflects and scans a light beam emitted from the light source according to sinusoidal vibration, and a scanning/imaging optical system that guides the light beam from the deflector to a scanned surface. The scanning/imaging optical system satisfies two conditions, i.e., (1) provided that the deflector moves in such a manner that an angular velocity is constant, linearity is made larger at a most peripheral image height than at a central image height within a range of an effective writing width, and (2) when a deflection angle of the deflector has a sinusoidal characteristic, the linearity is made smaller at the most peripheral image height than at the central image height within the range of the effective writing width.

Abstract: In an image forming apparatus including plural exposure units each deflecting a light beam from a light source by means of an oscillation mirror in resonant oscillations and scanning the deflected light beam on a latent image carrier thereby forming a latent image on the latent image carrier, every one of the exposure units assuredly attains an adequate amplitude of the oscillation mirror for ensuring the formation of images of high quality. More specifically, a CPU 101 retrieves resonant frequencies of individual deflectors previously stored in a memory. The CPU 101 calculates an average value of these resonant frequencies and applies a drive command to mirror drivers 1022 of the exposure units 6Y, 6M, 6C, 6K such as to drive all the deflectors into oscillations at the average value. Alternatively, a resonant-frequency adjusting section 653 makes adjustment to match the resonant frequencies of the individual deflectors substantially with a drive frequency.

Abstract: An optical scanning device and method are provided for marking an optically sensitive layer. The device can include an optical source capable of emitting a beam. At least one pivot can be configured to enable the beam to travel through a beam output arc. In addition, a mirror surface can be oriented toward the optically sensitive layer. The mirror surface can be configured to reflect the beam within the defined beam output arc onto a plurality of locations of the optically sensitive layer.

Abstract: An electrophotographic printer includes an exposure unit having a MEMS scanner operable to scan a beam of light across a photoconductor. The MEMS scanner includes a mirror having an aspect ratio similar to the shape of the facets of a conventional rotating polygon scanner. In a preferred embodiment, the scan mirror has a length of about 750 microns in a dimension parallel to its axis of rotation and a length of about 8 millimeters in a dimension perpendicular to its axis of rotation. The MEMS scanner is operable to scan at a frequency of about 5 KHz and an angular displacement of about 20 degrees zero-to-peak mechanical scan angle.

Abstract: In a scanning optical device which deflection-scans a plurality of fluxes of light by one rotary polygon mirror to form a multi-color image by irradiating beams on a plurality of photosensitive drums, respective, the fluxes of light being incident on the rotary polygon mirror have different angles with respect to a reference plane defined by a normal line of a reflecting surface of the rotary polygon mirror and a rotating direction of the rotary polygon mirror, and a flux of light deflection-scanned at the largest angle between the flux of light and the reference plane is irradiated on a photosensitive drum on which a color image having the highest brightness is formed. With this configuration, a scanning optical device in which a defective image caused by an optical facet angle error can be improved without improving the precision of parts and an image forming apparatus including the scanning optical device are provided.

Abstract: An image forming apparatus, includes: a latent image carrier whose surface includes an effective image region spanning across a predetermined width in a main scanning direction and is driven in a sub scanning direction approximately orthogonal to the main scanning direction; a latent image former which has a light source and a deflection mirror oscillating, and deflects a light beam from the light source using the deflection mirror so as to scan the effective image region with the deflected light beam; and a scanning mode controller which switches selectively between a single-side scanning mode and a double-side scanning mode, the single-side scanning mode being a mode in which the light beam is scanned only in a first direction included in the main scanning direction, the double-side scanning mode being a mode in which the light beam is scanned in both the first direction and a second direction opposite to the first direction, wherein a condition to form latent images on the latent image carrier in the singl

Abstract: An optical deflector of the present invention includes a movable mirror and torsion bars supporting the mirror and formed integrally with the mirror. The mirror reciprocatingly vibrates to reflect a light beam to thereby deflect it. The mirror is curved in the form of an arch in a section including at least the torsion bars. The mirror deforms little during vibration even if it is thin. Small power can cause such a thin mirror to vibrate with a large amplitude.

Abstract: A common photodetecting unit detects a plurality of beams scanned by a plurality of polyhedral reflection mirrors provided in a multiple stages with a common rotation axis, and generates a synchronization detection signal based on detected beams. The reflection mirrors make a predetermined angle ?1 in a direction of rotation of the reflection mirrors. When time between two consecutive synchronization detection signals on a time line generated by the common photodetecting unit is ti, where i is a positive integer equal to or smaller than number of split beams, at least one of ti is different from others.

Abstract: A deflector deflects a light beam emitted from a light source including a plurality of light-emitting units. A scanning optical system focuses the light beam deflected by the deflector on a scanning target surface. A monitoring photoreceiver receives a part of a light beam deflected by the deflector and directed toward an area within a scanning area outside an image area. A detecting unit individually detects emission powers of at least two light-emitting units based on an output signal of the monitoring photoreceiver in a single sweep of scanning.

Abstract: A pre-deflector optical system includes an isolator arranged on an optical path of a light beam from a light source. The isolator has a first surface with different light transmittances depending on a polarization state of an incident light beam on a first side close to the light source and a second surface imparting an optical phase difference of a ¼ wavelength to the incident light beam on a second side. A deflector deflects the light beam passed through the pre-deflector optical system. A rotation mechanism rotates the isolator around its optical axis. A holding member holds the light source and the isolator in a predetermined positional relationship.

Abstract: A lithographic scanning apparatus includes a light projection device for seamlessly and uniformly projecting a scanning light onto a light exposing area. The light projecting device further includes an array of micromirrors having a predefined distribution pattern of reflectance variations for reflecting an incident light onto the light exposing area to seamlessly and uniformly scanning a reflecting light over the light exposing area. In one of a lithographic scanning apparatus, the micromirrors of the micromirror array are coated with a reflective coating of different reflectance to provide the predefined distribution pattern of reflectance variations. In another lithographic scanning apparatus, the micromirrors of the micromirror array are coated with stripes of reduced reflectance whereby each micromirror may have predefined total reflectance to provide the predefined distribution pattern of reflectance variations.

Abstract: A scan-beam detection signal Hsync provided by horizontal synchronous sensors 60A, 60B is inputted to a drive signal controlling section 10Y as a drive period signal related to a drive period of a deflective mirror. The drive signal controlling section 10Y controls a drive signal Sd such as to establish a predetermined relationship between a phase of a reference signal Sr and a phase of the horizontal synchronous signal Hsync, whereby a deflector 65 is allowed to operate in synchronism with the reference signal Sr. Therefore, a latent-image forming position with respect to a sub-scan direction Y is adjusted by way of the phase adjustment between the reference signal Sr and the horizontal synchronous signal Hsync, so that a linear latent image is prevented from deviating with respect to the sub-scan direction Y.