Abstract: An optical scanning apparatus includes first and second light sources, a rotatable polygonal mirror, a motor, first and second mirrors, first and second lenses, and a casing. Within a mounting range, a top wall of an accommodating portion is provided with at least one projection projecting toward an opening of the accommodating portion. The projection extends from a first side wall to a second side wall of the accommodating portion. The top wall includes a recess formed opposite from the projection, and is free from a portion projecting toward the opening over a range from the first side wall to the second side wall, other than the projection in the mounting range. A free end portion of the projection is in a position remoter from the opening than a reflecting surface of the rotatable polygonal mirror is with respect to a rotational axis direction of the motor.

Abstract: An image reading apparatus for reading an image of an original includes an illumination portion for illuminating the original with light, a reflection member including a reflecting surface for reflecting the light from the original; a converting portion for photoelectrically converting the light reflected by the reflection member, and a casing for accommodating the reflection member. The casing is provided with an opening which is open to an outside of the casing. A surface of the reflecting member opposite from the reflecting surface and a portion defining the opening are bonded to each other with an adhesive.

Abstract: A LIDAR system includes a LIDAR unit. The LIDAR unit includes a housing defining a cavity. The LIDAR unit further include a plurality of emitters disposed on a circuit board within the cavity. Each of the emitters emits a laser beam along a transmit path. The LIDAR system further includes a first optic rotatable about a first axis at a first rotational speed and a second optic rotatable about a second axis at a second rotational speed that is faster than the first rotational speed. The first optic is positioned relative to the LIDAR unit such that a plurality of laser beams exiting the LIDAR unit pass through the first optic. The second optic is positioned relative to the first optic such that each of a plurality of refracted laser beams exiting the prism disk reflect off of the second optic.

Abstract: A rotatable polygon mirror including a plurality of reflecting surfaces includes first and second surfaces connecting to the reflecting surfaces provided on opposite ends, first and second protrusion portions with an annular shape, provided on the first and second surfaces and protruding inversely to each other in the rotational axis direction, about a rotational axis of the rotatable polygon mirror. A height of a top surface portion of the first protrusion portion from the first surface is higher than that of a top surface portion of the second protrusion portion from the second surface with respect to the rotational axis direction. In a case that the rotatable polygon mirrors are stacked in the rotational axis direction, a wall of an inner peripheral side of the first protrusion portion and a wall of an outer peripheral side of the second protrusion portion are engaged with each other.

Abstract: An optical scanning apparatus includes first and second light sources, a rotatable polygonal mirror, a motor, first and second mirrors, first and second lenses, and a casing. Within a mounting range, a top wall of an accommodating portion is provided with at least one projection projecting toward an opening of the accommodating portion. The projection extends from a first side wall to a second side wall of the accommodating portion. The top wall includes a recess formed opposite from the projection, and is free from a portion projecting toward the opening over a range from the first side wall to the second side wall, other than the projection in the mounting range. A free end portion of the projection is in a position remoter from the opening than a reflecting surface of the rotatable polygonal mirror is with respect to a rotational axis direction of the motor.

Abstract: A polygonal mirror includes reflecting surfaces, a molded member including a first surface and a second surface, a contact portion, and gate marks. Each of said first surface and said second surface has a polygonal shape. The contact portion and the gate marks are formed at non-overlapping positions with a line segment connecting a vertex of the polygonal shape with a rotation center. The gate marks and the reflecting surfaces are the same in number. A perpendicular bisector of a line segment connecting centers of the gate marks adjacent to each other with respect to a rotational direction of the polygonal mirror is formed at a position passing through an associated vertex of the polygonal shape and the rotation center.

Abstract: An image reading apparatus for reading an image of an original includes an illumination portion for illuminating the original with light, a reflection member including a reflecting surface for reflecting the light from the original; a converting portion for photoelectrically converting the light reflected by the reflection member, and a casing for accommodating the reflection member. The casing is provided with an opening which is open to an outside of the casing. A surface of the reflecting member opposite from the reflecting surface and a portion defining the opening are bonded to each other with an adhesive.

Abstract: A LIDAR system includes a laser source configured to output a first beam and a polygon scanner. The polygon scanner includes a plurality of facets. Each facet of the plurality of facets is configured to transmit a second beam responsive to the first beam. The plurality of facets include a first facet having a first field of view over which the first facet transmits the second beam and a second facet having a second field of view over which the second facet transmits the second beam. The first field of view is greater than the second field of view.

Abstract: An image reading unit includes an illumination portion, a reading portion, a casing, and a reflection member including a reflecting surface. The casing is provided with an opening. The reflection member is held outside of the opening of the casing so that at least a part of the reflecting surface is exposed to the inside of the casing through the opening.

Abstract: Disclosed herein are a number of example embodiments that employ controllable delays between successive ladar pulses in order to discriminate between “own” ladar pulse reflections and “interfering” ladar pulses reflections by a receiver. Example embodiments include designs where a sparse delay sum circuit is used at the receiver and where a funnel filter is used at the receiver. Also, disclosed are techniques for selecting codes to use for the controllable delays as well as techniques for identifying and tracking interfering ladar pulses and their corresponding delay codes. The use of a ladar system with pulse deconfliction is also disclosed as part of an optical data communication system.

Abstract: A LIDAR system includes a laser source configured to output a first beam and a polygon scanner. The polygon scanner includes a plurality of facets. Each facet of the plurality of facets is configured to transmit a second beam responsive to the first beam. The plurality of facets include a first facet having a first field of view over which the first facet transmits the second beam and a second facet having a second field of view over which the second facet transmits the second beam. The first field of view is greater than the second field of view.

Abstract: The present disclosure provides a display system that may comprise a retro-reflective screen configured to reflect incident light along a direction that is opposite to the direction of propagation of the incident light, and a projector that may project light characterizing an image or video to the retro-reflective screen. An array of optical elements or an individual optical element may be positioned between the retro-reflective screen and the projector. The array of optical elements or individual optical element may direct the light from the projector to the retro-reflective screen in a manner such that the image or video is viewable by a user at an observation angle of at least about 2 degrees.

Abstract: Spectral beam combining systems including a multi-element transform optic. In certain examples the multi-element transform optic includes a first cylindrical optical element having positive optical power in a first axis, a second optical element having negative optical power in the first axis, and a third toroidal optical element having positive optical power in the first axis and either positive or negative optical power in a second axis that is orthogonal to the first axis. The first and third optical elements are positioned on opposite sides of the second optical element and equidistant from the second optical element. The multi-element transform optic has an optical path length extending between a front focal plane and a back focal plane that is shorter than an effective focal length of the multi-element transform optic.

Abstract: An image forming apparatus including an optical scanning device that scans an object to be scanned with a beam in a main scanning direction includes a first rotation fulcrum unit and a second rotation fulcrum unit that are respectively provided in the optical scanning device on one side and on the other side in an orthogonal direction orthogonal to the main scanning direction. The first rotation fulcrum unit is provided outside a scanning area of the beam in the main scanning direction. The optical scanning device is provided rotatably around a virtual rotation axial line connecting the first rotation fulcrum unit and the second rotation fulcrum unit.

Abstract: In a distance measuring apparatus, a housing is made of a first material that is non-transmissive of an electromagnetic wave, and includes an inner chamber, and a window portion made of a second material that is transmissive of the electromagnetic wave and reflection wave. The housing includes a partitioning wall made of a third material that is non-transmissive of the electromagnetic wave. The partitioning wall is configured to partition the inner chamber of the housing into a first container chamber and a second container chamber. In the first container chamber, a transceiver is installed. The first container chamber communicates with the window portion. In the second container chamber, the processing unit is installed.

Abstract: A lidar system includes a light source configured to produce a beam of light, a scanner configured to scan a field of regard of the lidar system, and a receiver configured to detect light from the beam of light scattered by a remote target. The scanner includes a polygon mirror having a block with a first wall, a second wall, and several reflective surfaces angularly offset from one another along a periphery of the block, the polygon mirror configured to rotate about a scan-mirror rotation axis to scan the beam of light across the field of regard. The scanner further includes a bracket adjacent to the polygon mirror, where at least one of the polygon mirror or the bracket includes a noise-reducing feature configured to reduce acoustic noise produced when pressure waves generated by the polygon mirror during rotation are incident on one or more components of the scanner.

Abstract: An image forming apparatus including an optical scanning device that scans an object to be scanned with a beam in a main scanning direction includes a first rotation fulcrum unit and a second rotation fulcrum unit that are respectively provided in the optical scanning device on one side and on the other side in an orthogonal direction orthogonal to the main scanning direction. The first rotation fulcrum unit is provided outside a scanning area of the beam in the main scanning direction. The optical scanning device is provided rotatably around a virtual rotation axial line connecting the first rotation fulcrum unit and the second rotation fulcrum unit.

Abstract: A polygon mirror includes a substrate having a plurality of side surfaces, a first base surface connecting to the plurality of side surfaces, and a second base surface connecting to the plurality of side surfaces, the first base surface and the second base surface facing away from each other. Each side surface has a first region, and a second region adjoining the first region and extending between the first region and at least one edge of the side surface. The substrate is made of plastic, and a reflection coating is formed on the first region and the second region. A surface roughness of the second region of the substrate is greater than a surface roughness of the first region of the substrate. A method for manufacturing such a polygon mirror and an optical reflecting mirror are also provided.

Abstract: A display device that includes an attachment part mountable on a head of a user, a control device to control the attachment part, and a transmission cable to connect the attachment part with the control device, further includes an imager; a first converter configured to convert a digital signal from the imager into an analog signal; a second converter configured to convert the analog signal into a video signal; a laser light generator configured to generate a laser light modulated depending on the video signal; an optical scanner configured to scan the laser light; and an optical projection system configured to project the scanned laser light to form an image. The imager, the first converter, the optical scanner, and the optical projection system are placed in the attachment part. The second converter and the laser light generator are placed in the control device. The analog signal and the laser light are transmitted via the transmission cable.

Abstract: An image forming apparatus includes a laser device, a sensor, and a control unit. The laser device emits laser light which is reference for image forming. The sensor detects the laser light emitted from the laser device. The control unit changes an output direction of the laser light emitted from the laser device if the laser light is not detected by the sensor.

Abstract: An optical lens for laser marking includes a first lens (L1), a second lens (L2), and a third lens (L3), which are successively coaxially arranged along a transmission direction of incident light, wherein the first lens (L1) and the second lens (L2) are meniscus lenses, and the third lens (L3) is a biconvex lens; wherein the first lens (L1) has a first surface (S1) and a second surface (S2), the second lens (L2) has a third surface (S3) and a fourth surface (S4), the third lens (L3) has a fifth surface (S5) and a sixth surface (S6); the first surface (S1) to the sixth surface (S6) are successively arranged along the transmission direction of the incident light; wherein radii of curvature of the first surface to the sixth surface are ?47±5% mm, ?, ?218±5% mm, ?81±5% mm, 778±5% mm, and ?142±5% mm, respectively; wherein central thicknesses of the first lens, the second lens, and the third lens are 4±5% mm, 15±5% mm, and 18±5% mm, respectively.

Abstract: An image forming apparatus, including: a deflection unit configured to deflect light beams emitted from light emitting points with a mirror face to form scanning lines in a second direction orthogonal to a first direction in which a photosensitive drum is rotated; a correction unit configured to correct an optical face tangle error of the mirror based on a deviation amount from a distance between the deflection unit and the photosensitive member; a calculation unit configured to calculate a positional deviation amount of the emitting points in the first direction; a transformation unit configured to transform a pixel position of an input image based on the positional deviation amount so that an interval between the scanning lines is a predetermined interval; and a filtering unit configured to obtain a pixel value of an output image based on the transformed pixel position of the input image.

Abstract: A polygon mirror made of plastic is provided. The polygon mirror has a plurality of reflecting surfaces, a first surface intersecting the plurality of reflecting surfaces at a first side, a second surface intersecting the plurality of reflecting surfaces at a second side opposite to the first side, with a through hole provided to extend through the first surface and the second surface at a center of the polygon mirror. The polygon mirror includes a plurality of gate marks of injection molding. When viewed from an extending direction of the through hole, the gate marks are located on straight lines passing through the center and vertices of the first surface, and are rotationally symmetric with respect to the center.

Abstract: A surface scattering reflector antenna includes a plurality of adjustable scattering elements and is configured to produce a reflected beam pattern according to the configuration of the adjustable scattering elements.

Abstract: Disclosed is an optical deflector which includes: a polygonal mirror, a drive motor, a cover member, and a temperature detection unit. The cover member includes: a first cover portion defining a first space in which the polygonal mirror is installed, wherein the first cover portion is formed with a first opening opened in opposed relation to an outer peripheral surface of the polygonal mirror; a second cover portion defining a second space which is communicated with the first space and in which the drive motor is installed, wherein the second cover portion is formed with a second opening opened in opposed relation to a motor body of the drive motor; and a third cover portion defining a third space which is communicated with the second space. The temperature detection unit is mounted to the third cover portion so as to close the third space.

Abstract: Disclosed is an optical deflector including a polygonal mirror and a drive motor each mounted on a substrate, a cover member covering the polygonal mirror and the drive motor, and an electronic component. The cover member includes: a first cover portion defining a first space in which the polygonal mirror is installed, wherein the first cover portion is formed with a first opening opened in opposed relation to an outer peripheral surface of the polygonal mirror; and a second cover portion defining a second space which is communicated with the first space and in which the drive motor is installed, wherein the second cover portion is formed with a second opening opened in opposed relation to a motor body of the drive motor. When viewed in the first direction, the electronic component is disposed such that it falls within an open region of the second opening.

Abstract: A mirror for EUV radiation comprises a total reflection surface, which has a first EUV-radiation-reflecting region and at least one second EUV-radiation-reflecting region, wherein the EUV-radiation-reflecting regions are structurally delimited from one another, wherein the first region comprises at least one first partial reflection surface which is surrounded along a circumference in each case by the at least one second region, and wherein the at least one second EUV-radiation-reflecting region comprises at least one second partial reflection surface which is embodied in a path-connected fashion and which is embodied in a continuous fashion.

Abstract: The disclosure relates to a measuring apparatus, in particular a handheld measuring apparatus, for measuring a target object in a multidimensional manner, wherein the distance to individual object points of the target object is sequentially measured, in particular using a phase-measuring system, which apparatus has at least: a transmitting device for emitting optical measuring radiation towards the target object; a receiving device having a detection area for detecting optical measuring radiation returning from the target object; a scanning system for deflecting the optical measuring radiation, and an evaluation device for determining measured distance values. The detection area of the receiving device has a plurality of pixels, wherein each pixel has at least one SPAD, and wherein each of the plurality of pixels is connected to the evaluation device. The disclosure also relates to a measuring device having such a measuring apparatus.

Abstract: Various beam selectors for selectively placing one of at least two beams of light along the same output path are disclosed. In one aspect, a beam selector receives at least two substantially parallel beams of light. The beam selector includes a plate with an aperture so that when one of the at least two beams is selected for transmission, the beam selector directs only the selected beam along an output path through the aperture. The plate can also serve to block transmission of unselected beams. The output path through the aperture is the same for each of the at least two beams when each beam is selected. Beam selectors can be incorporated into fluorescence microscopy instruments to selectively place particular excitation beams along the same path through the microscope objective lens and into a specimen to excite fluorescence of fluorescent probes attached to a particular component of the specimen.

Abstract: The invention relates to reflective optical elements for a dynamic deflection of a laser beam and to a manufacturing method for these reflective elements. It is the object of the invention to provide reflective optical elements for a dynamic deflection of laser beams which can be manufactured less expensively and which are flexible in their geometrical design so that they achieve improved properties in dynamic operation. In the reflective optical element in accordance with the invention, a surface of a base body and a plate-shaped reflective element are connected to one another in a planar manner and with material continuity by means of a solder connection.

Abstract: An optical scanning apparatus includes an optical box having a top surface that is constituted by a single lid. A first surface of the top surface is disposed closer to a rotary polygon mirror than a second surface and is disposed closer to a bottom surface of the optical box than an edge portion of a light deflector positioned farthest from the bottom surface. A third surface of a convex portion of the top surface is positioned farther from the bottom surface than the first surface. A lower edge portion of the convex portion is disposed outside a circumscribed circle of the rotary polygon mirror.

Abstract: A scan unit for an imaging device having a movable mirror and one or more light sources. A light beam generated by each light source is directed towards the movable mirror, movement of the mirror causing each light beam that is reflected by the mirror to follow a distinct scan pattern. An optical assembly is associated with each reflected light beam to form an optical path for each reflected light beam from the mirror. A housing in which the movable mirror, the one or more light sources and the optical assembly are secured has at least a portion made from electrically conductive material for shielding an interior of the housing from electromagnetic fields external to the housing. A light drive circuitry card is disposed in the interior of the housing and communicatively coupled to the one or more light sources for driving the one or more light sources.

Abstract: An optical scanning device includes a light source portion, a deflector, a first focus lens, a second focus lens, a first mirror group, and a second mirror group. The first mirror group includes: a first reflection mirror on which a first light beam having transmitted through a first focus lens is incident, the first reflection mirror reflecting the first light beam in a second direction away from a first scanned surface; and a second reflection mirror that reflects the reflected first light beam toward the first scanned surface. The second mirror group includes: a third reflection mirror on which a second light beam having transmitted through a second focus lens is incident, the third reflection mirror reflecting the second light beam in the first direction of approaching the second scanned surface; and a fourth reflection mirror that reflects the reflected second light beam toward the second scanned surface.

Abstract: A method of scanning a light beam is disclosed. The method comprises scanning the light beam along a first axis and scanning the light beam along a second axis, such that a functional dependence of the scanning along the first axis is substantially a step-wave, and a functional dependence of the scanning along the second axis is other than a step-wave.

Abstract: The light source body of an optical scanner includes a main frame and a disc portion. The main frame is formed into a cylindrical columnar shape so as to irradiate the light beams from a front end thereof. The disc portion protrudes radially outward from a rear end side of the main frame. A side plate of the housing have a through-hole. The side plate includes a support member installed on the outer surface. The support member has an arc surface formed to extend along a edge portion of the through-hole. A pressing member is configured to press the disc portion of the light source body against the arc surface of the support member in such a state that the front end of the main frame is inserted into the through-hole and that an end surface of the disc portion makes contact with the side plate of the housing.

Abstract: An information processing apparatus for frequency domain optical coherence tomography comprises an image scanning unit that receives measurement data from an optical coherence tomography device, while moving a measurement point to the next adjacent point at each measurement time by controlling the optical coherence tomography device, and generates depth information based on the measurement data to produce a raw tomographic image. The apparatus includes a noise reduction unit that reduces noise from the raw tomographic image to produce a result tomographic image. The noise reduction unit reduces the noise from the raw tomographic image by subtracting the depth information generated by the image scanning unit at each measurement time from the depth information generated at another measurement time adjacent to said each measurement time.

Abstract: A light scanner includes: a base part; a shaft part that swingably supports the base part around a first axis; an optical unit including a light transmission part that is supported by the base part and has light transmissivity, and a first light reflection reduction part that is provided on the light transmission part and reduces light reflection, wherein light enters the first light reflection reduction part.

Abstract: An optical scanning device for scanning a photoreceptor surface with beams includes a light source that emits multiple beams in one direction, a deflector for deflecting the beams, a detector for detecting light intensities of the beams, and a switch for switching travel routes of the beams between a first route leading from the light source to the deflector and a second route leading from the light source to the detector.

Abstract: A polygonal rotating mirror, a light scanning unit employing the polygonal rotating mirror, and an electrophotographic image forming apparatus are shown. The polygonal rotating mirror is employed in the light scanning unit for scanning a light beam and includes a plurality of reflective surfaces enclosing outer side surfaces thereof. One of the plurality of reflective surfaces is a reference surface, a region of the reference surface where a light beam for a synchronization signal is to be incident is formed as a non-reflective region, and regions of the remaining reflective surfaces of the plurality of reflective surfaces where a light beam for a synchronization signal is to be incident, are formed as reflective regions.

Abstract: Disclosed are a 3D laser scanning system and a method of obtaining a 3D image by using the system that detect, with a linear array type photo detector, a reflected light reflected from a target after rotation-emitting a line-shaped pulsed laser light through 360 degrees and obtain a 3D image through point cloud data obtained by measuring a distance to the target.

Abstract: A polygon mirror assembly, a light scanning unit employing the polygon mirror assembly, and an image forming apparatus. The polygon mirror assembly includes a polygon mirror formed of a plastic material and having a plurality of reflection surfaces; and a motor unit to support and rotate the polygon mirror, where the polygon mirror is coupled to the motor unit by using an adhesive material.

Abstract: Systems and methods for providing laser texturing of solid substrates are disclosed. The texturing may be used to provide grayscale images obtainable from substrates, which may include steel, aluminum, glass, and silicon. In some embodiments, images may be obtainable from the substrate by modifying the reflective, diffractive, and/or absorptive features of the substrate or the substrate surface by forming random, periodic, and/or semi-periodic micro-structure features on the substrate (or substrate surface) by an ultrafast laser pulse train. The ultrafast pulse train may be modulated in order to vary, for example, optical exposure time, pulse train intensity, laser polarization, laser wavelength, or a combination of the aforementioned. The ultrafast pulse train and the substrate may be scanned with respect to each other to provide different optical energies to different regions of the substrate (or substrate surface).

Abstract: An optical scanning apparatus and an image forming apparatus including the optical scanning apparatus, the optical scanning apparatus includes a dust-proof shutter having an opening portion. The opening portion has a side-surface opening portion and a top-surface opening portion. The side-surface opening portion is formed in a side surface of the dust-proof shutter. A cleaning member used for cleaning a dust-proof glass is inserted through the side-surface opening portion. The top-surface opening portion guides a moving direction of the cleaning member inserted through the side-surface opening portion, to a direction along a longitudinal direction of the dust-proof glass. When the dust-proof shutter is located at a first position, a light beam passed through the dust-proof glass passes through the top-surface opening portion.

Abstract: An optical scanning device is disclosed. The optical scanning device comprises an overfilled optical system in which an incoming light beam, formed wider than a width in a rotation direction of a rotating multifaceted mirror's reflective surface, is caused to be incident on the reflective surface and a scanning object's scanning surface is scanned by an outgoing beam reflected by the reflective surface. The incoming beam is incident on the rotating multifaceted mirror's reflective surface, having an angle with respect to a virtual vertical surface that is vertical to the scanning surface and the outgoing beam's scanning direction. A light amount distribution for positions on the scanning surface in the scanning direction is corrected based on a slope of a straight line that expresses a ratio of light amount changes for positions on the scanning surface in the scanning direction when scanning the scanning surface using the outgoing beam.

Abstract: The image reading apparatus includes a light transmissive member, a first light source causing a first light to enter the light transmissive member from a first side face of side faces thereof, a second light source illuminating a document laid on an upper face of the light transmissive member with a second light, an image sensor photoelectrically converting an optical image, and an imaging optical system forming on image sensor the object image with light exiting from the light transmissive member. The first light source is disposed such that the first light emitted therefrom and entering the light transmissive member from the first side face satisfies a total reflection condition at the upper and lower faces of the light transmissive member.

Abstract: In a scanning optical apparatus, an illumination optical system has a diffractive power ?dM and a refractive power ?nM in a main scanning direction, and a ratio ?nM/?dM in the main scanning direction for a focal length fi in a range of 10-22 mm satisfies: g2(fi)??nM/?dM?g1(fi), where A(Z)=(1.897×107)Z2+6744Z+0.5255, B(Z)=(2.964×107)Z2+5645Z+0.6494, C(Z)=(3.270×107)Z2+3589Z+0.5250, D(Z)=(5.016×107)Z2+4571Z+0.8139, g1(fi)=fi{D(Z)?B(Z)}/12?5D(Z)/6+11B(Z)/6, g2(fi)=fi{C(Z)?D(Z)}/12?5C(Z)/6+11A(Z)/6.

Abstract: An optical scanning device includes a vertical-cavity surface-emitting laser light source that emits laser beams perpendicular to a top surface thereof; a first optical system that couples the beams from the light source; a deflecting unit that deflects the beams; a second optical system that guides the beams from the first optical system to the deflecting unit; a third optical system that focuses the beams deflected by the deflecting unit into an optical spot on a scanned surface; and a light-quantity adjusting element disposed between the light source and the deflecting unit and having a substrate formed of a first and second surfaces. The first surface of the light-quantity adjusting element is coated with neutral density coating and the second surface is coated with antireflection coating so that reflectance of the second surface is made smaller than reflectance of the first surface.

Abstract: A polygon mirror assembly, a light scanning unit employing the polygon mirror assembly, and an image forming apparatus. The polygon mirror assembly includes a polygon mirror formed of a plastic material and having a plurality of reflection surfaces; and a motor unit to support and rotate the polygon mirror, where the polygon mirror is coupled to the motor unit by using an adhesive material.

Abstract: The present disclosure is directed to an illumination system. The illumination system may include a base member rotatable about a rotation axis and a plurality of mirrors disposed on an outer surface of the base member along a perimeter of the base member. The mirrors may be oriented at a predetermined angle. The illumination system also includes at least two illumination sources. Each of the mirrors of the first plurality of mirrors is configured to receive radiation from the first illumination source at a first portion of each mirror at a first time. The mirror is configured to reflect the radiation to an optical path. Each of the mirrors is further configured to receive radiation from the second illumination source at a second portion of the mirror at a second time. The mirrors reflect the radiation from the second illumination source to the common optical path.

Abstract: A scanning optical apparatus includes: a light source; a light deflector configured to deflect the light beam from the light source in a main scanning direction; an incident optical system disposed between the light source and the light deflector and configured to render the light beam from the light source nearly parallel in the main scanning direction and to converge the light beam in a sub-scanning direction to bring the light beam to a focus in proximity to the light deflector; and a scanning lens configured to focus the light beam deflected by the light deflector onto a target surface to form spot-like images. The incident optical system includes one or more lenses which provide at least one refracting surface and at least one diffraction surface, and ?nS/?ds<0 is satisfied, where ?nS is a refractive power in the sub-scanning direction and ?dS is a diffraction power in the sub-scanning direction.