Abstract: The present disclosure provides a protection apparatus for a galvanometer laser system, including a system constituted by a galvanometer motor and a laser, wherein the apparatus further includes a protection device, the protection device including a monitoring element and a control element; wherein the monitoring element includes a current monitoring module configured to monitor an operating current of the system, a position monitoring module configured to monitor a swing position of the galvanometer motor, and a temperature monitoring module configured to monitor an operating temperature of the galvanometer motor; the control element includes a signal control module connected to a signal input terminal of the system, a laser switch module connected to the laser, and a galvanometer drive module connected to the galvanometer motor, a predetermined output signal being transmitted via the signal control module to the system; and based on various monitoring data of the monitoring element.

Abstract: An optical element driving mechanism is provided, including a fixed part, a movable part and a driving assembly. The fixed part has a main axis, includes an outer frame and a base. The outer frame has a top surface and a sidewall. The top surface intersects the main axis. The sidewall extends from the edge of the top surface along the main axis. The base includes a base plate intersecting the main axis and securely connected to the outer frame. The movable part moves relative to the fixed part, and connects to an optical element having an optical axis. The driving assembly drives the movable part to move relative to the fixed part. The main axis is not parallel to the optical axis.

Abstract: An image forming apparatus includes: a photosensitive member; a process member configured to act on the photosensitive member; and a light scanning apparatus configured to emit a light beam to the photosensitive member. The light scanning apparatus includes: a light source; a rotary polygon mirror; a first signal generating unit configured to receive the light beam deflected by the rotary polygon mirror to generate a first signal indicating a scan starting position; and a second signal generating unit configured to generate a second signal based on a rotation angle of the rotary polygon mirror. A lighting-up timing of the light source for generating the first signal is determined based on a number of the second signals after a voltage for image formation is applied and a relationship between the first signal and the second signal is obtained before the voltage is applied and after the rotary polygon mirror is rotated.

Abstract: A two-dimensional scanning projector causing a light beam to scan in a first direction and a second direction orthogonal to the first direction, comprising: a first deflector which deflects the light beam in the first direction; and a scanning optical system arranged between the first deflector and a scanned surface, wherein the first deflector is arranged such that a rotation axis of the first deflector is inclined, in a plane including an optical axis of the scanning optical system and the second direction, by a first angle with respect to the second direction, and the light beam is incident on the first deflector such that, in the plane including the optical axis and the second direction, a chief ray of the light beam entering a center of a projected image is obliquely incident on the first deflector to form a second angle with respect to the optical axis.

Abstract: Methods and systems for performing dynamic aperture holography are described. Examples include a method of recording multiple holograms in a photosensitive recording medium, where multiple signal beam angular apertures used to record the multiple holograms differ from each other. The multiple signal beam angular apertures can facilitate using a larger range of reference beam angular apertures. The multiple holograms are typically multiplexed, and examples of dynamic aperture holography enable packing the multiplexed holograms more densely in the recording medium. Some dynamic aperture holography systems include monocular objective lens architecture.

Abstract: A monocular holographic storage device or system to provide for compact recording and/or reading of data pages in a holographic storage medium. Also provided are methods for carrying out such data storage and/or data recovery using a monocular holographic storage device or system. Further provided are articles including holographic storage media for recording or for reading recorded data using such devices or systems.

Abstract: An image generation apparatus for generating an image includes a light source device; an optical deflection device to deflect laser beam from the light source device to a scanned face and a light detector; a light quantity adjustment device including a member disposable on a light path of the laser beam between the light source device and the optical deflection device; an emission light intensity adjustment unit to adjust emission light intensity of the light source device; and a controller to set a first adjustment target value of emission light intensity and an adjustment target value of light quantity when laser beam is deflected to the scanned face based on target luminance of the image, and a second adjustment target value of emission light intensity when laser beam is deflected to the light detector based on an adjustment target value of light quantity and detection sensitivity of the light detector.

Abstract: A printing apparatus sets, as time for performing pre-processing before performing print processing, first time if the printing rate calculated by the calculation unit is smaller than a predetermined value, and second time that is longer than the first time if the printing rate calculated by the calculation unit is larger than the predetermined value.

Abstract: An image forming apparatus including: a photosensitive member; a charging unit; a light scanning apparatus configured to emit a light beam to scan the photosensitive member to form a latent image; and a developing unit configure to develop the latent image. The light scanning apparatus includes a light source, a rotary polygon mirror, a light receiving unit, and a signal generating unit. An incident timing when the light beam deflected by the polygon mirror enters the light receiving unit after the photosensitive member is charged by the charging unit and after a voltage is applied to a toner carrying member by the developing unit is identified based on the number of second signals generated by the signal generating unit between the first signal and the first signal generated by the light receiving unit before the photosensitive member is charged and before the voltage is applied to the toner carrying member.

Abstract: In an optical information recording/reproducing device that radiates signal light and reference light to a recording medium, forms a hologram, and records information and emits the reference light to the hologram of the recording medium and reproduces information, a laser light source that generates the signal light and the reference light; a light angle control unit that controls an angle of the reference light incident on the recording medium; a light detecting unit that detects diffracted light when the reference light is radiated; a positioning unit that allocates an address to the recording medium and performs positioning of the recording medium for the address; a tilt measuring unit that measures a tilt of the recording medium; and a control unit that controls the incidence angle of the reference light, on the basis of a tilt measurement result in a recording mode, in a reproduction mode, are included.

Abstract: An optical writing device includes a light source, an optical deflector that deflects and scans light from the light source, a pre-deflector optical system that guides the light from the light source to the deflector, a post-deflector optical system that guides the scanned light to a target surface, a cover covering the deflector and including a first opening and a second opening provided at different positions, and a housing housing these optical elements. Light traveling from the light source to the deflector and the light scanned by the deflector are transmitted through the first opening but not through the second opening. During the rotation of the deflector, a forced inflow of air flowing from outside to inside the cover is generated in the first opening, and a discharged airflow flowing from inside to outside the cover is generated in the second opening.

Abstract: An actuator includes a frame, a driver portion having one end connected to an inside of the frame, a movable portion connected to another end of the driver portion, and an electrode provided at the movable portion. The driver portion vibrates the movable portion by being driven by a driving signal. The electrode receives a high-frequency signal higher than that of the driving signal. This actuator is driven at a high speed by a large deflection angle, and can prevent dust from adhering to the movable portion.

Abstract: A light beam emission apparatus separates, via a half mirror, apart of a laser beam emitted from a semiconductor laser towards a photosensitive member, guides the separated laser beam to an optical sensor to detect a light quantity, and controls the light quantity based on the detected result. The light beam emission apparatus includes a first light blocking member located between the semiconductor laser and the half mirror, and a second light blocking member located between the half mirror and the optical sensor.

Abstract: An optical scanning device includes a housing, a laser light source outputting a laser light, a polygon mirror arranged in an arrangement space and deflecting the laser light to scan a predetermined object with the laser light while rotating, a polygon motor rotating the polygon mirror, a control board arranged in the arrangement space and controlling the polygon motor, and a flow-control member arranged in the arrangement space and guiding an airflow generated by a rotation of the polygon mirror to an outside of the arrangement space to circulate the airflow within the housing.

Abstract: An optical scanning device includes a plurality of stations, each of which includes an light source, a deflector (polygon scan), a scanning optical element, and a housing. The light source emits a light beam to a plurality of surfaces to be scanned. The deflector deflects light beams emitted from the light source. The scanning optical element scans the surfaces to be scanned with light spots of the optical beams deflected by the deflector. The housing houses therein the light source, the deflector, and the scanning optical element. The scanning optical element is secured to the housing so that directions of scanning-line curves caused by temperature change match between the surfaces to be scanned.

Abstract: An optical scanning device has a light deflector deflecting a light beam from a light source, a synchronization detection sensor determining timing of starting scanning in main scanning direction based on timing of detecting the light beam scanned in main scanning direction by the light deflector, and a pre-sensor imaging optical system imaging the light beam reflected from the light deflector on the synchronization detection sensor. The pre-sensor imaging optical system moves the imaging position of the light beam on the synchronization detection sensor in a direction making the timing of detecting the light beam earlier or later according to whether variation in temperature causes the magnification of the scanning optical system in main scanning direction to increase or decrease respectively.

Abstract: An optical writing device includes a light source, an optical deflector that deflects and scans light from the light source, a pre-deflector optical system that guides the light from the light source to the deflector, a post-deflector optical system that guides the scanned light to a target surface, a cover covering the deflector and including a first opening and a second opening provided at different positions, and a housing housing these optical elements. Light traveling from the light source to the deflector and the light scanned by the deflector are transmitted through the first opening but not through the second opening. During the rotation of the deflector, a forced inflow of air flowing from outside to inside the cover is generated in the first opening, and a discharged airflow flowing from inside to outside the cover is generated in the second opening.

Abstract: The image forming apparatus includes a determination unit configured to determine whether or not a polygon mirror has converged to the number of rotations that allows image formation to be performed, and the determination unit is capable of detecting a first timing and a second timing and determines that the polygon mirror has converged to a number of rotations that allows the image formation to be performed based on an earlier one of the first timing and the second timing.

Abstract: An image forming apparatus includes an image forming unit which transfers an image obtained through exposure and development to paper, and a control unit which changes a rotation speed of a polygon mirror at an intermediate area on a carrier to change a reduction/magnification ratio of an image. The control unit changes the rotation speed in a stepwise manner in such a way as to allow a stable rotation of the polygon mirror in each step, and controls the image forming unit to form a corrected patch image in parallel with the stepwise change of the rotation speed. The corrected patch image is obtained through correction in accordance with the stepwise change of the rotation speed to be the same as the patch image formed when the rotation speed is not changed.

Abstract: The calculation unit calculates the time interval between the time at detecting the light beam reflected by the reflective surface of the rotatory polyhedron incident on the BD sensor by the light beam detecting unit and the time at detecting the light beam reflected by the reflective surface incident on the optical sensor in the light source by the return light beam detecting unit. The scan adjusting unit adjusts the luminescence time of the light source for scanning the light beam on the surface to be scanned based on the time interval calculated by the calculation unit.

Abstract: An optical scanning device includes: a light source unit; a light deflecting unit that deflects a light beam emitted from the light source unit; a scanning optical device that focuses the light beam deflected by the light deflecting unit on a scanned surface; and a light shielding member. The scanning optical device is provided in a direction in which a sound pressure level of a noise caused by rotation of a rotating polygon mirror included in the light deflecting unit is highest.

Abstract: Disclosed are methods, systems, and/or apparatus for the collective marking of a surface by two or more laser beams generated by a laser controller. A method includes receiving one or more input signals from a controller of the laser system. The method also includes adjusting a first mirror through a first galvanometer scanner, a second minor through a second galvanometer scanner, a third mirror through a third galvanometer scanner, and a fourth mirror through a fourth galvanometer scanner based on the one or more input signals. The method further includes steering, through the first mirror and the second mirror, a first laser beam generated by the controller and transmitted to a marking head through a beam delivery vessel; and steering, through the third mirror and the fourth minor, a second laser beam generated by the controller and transmitted to the marking head through another beam delivery vessel.

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: An optical scanning device includes a MEMS mirror, a driving unit for oscillating the MEMS mirror using a drive voltage which varies in a basic cycle, a light detection unit for receiving laser light deflected by the MEMS mirror and outputting a detection signal, a correction value calculation unit for calculating a correction voltage value used in correcting the drive voltage, a DC voltage generation unit for generating a DC voltage having a voltage value smaller than the correction voltage value, a DC voltage amplification unit for amplifying the DC voltage generated by the DC voltage generation unit to have a voltage value equal to the correction voltage value, and a waveform shaping unit for shaping the waveform of the amplified DC voltage so that the DC voltage varies in the basic cycle and outputting the shaped DC voltage as the drive voltage to the driving unit.

Abstract: An optical scanning device includes a polygon scanner that deflects and scans light beams, a body on which the polygon scanner directly mounted, and a heat dissipating unit that dissipates heat of the deflection scanning unit. The heat dissipating unit is located at a position on an outer surface of the body corresponding to the deflection scanning unit. The body is provided with a pair of wall portions on the outer surface. The wall portions face each other with the heat dissipating unit between them, and extend in a direction in which air blown by an air blowing unit flows to form an air-flow path.

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: Disclosed are a light scanning unit and an electrophotographic image forming apparatus including the light scanning unit. The light scanning unit may include a light source emitting a light beam, a beam deflector that deflects and scans the light beam emitted from the light source in a main scanning direction, a scanning optical system forming an image of a first portion of the light beam that is deflected and scanned by the beam deflector on a scanning surface and a beam detection sensor receiving a second portion of the light beam that is deflected and scanned by the beam deflector for generating a synchronization signal. The beam detection sensor may include a light receiving surface for receiving the second portion of the light beam, and at least two output terminals that are arranged outside an area of the light receiving surface within which the incident second portion of the light beam is confined.

Abstract: A laser light irradiating system which irradiates a laser light onto a thermally reversible recording medium which is pasted on a face on one side of an object to be conveyed to perform one of image erasing and image recording is disclosed. The laser light irradiating system includes a conveying unit; a detecting unit; a laser light emitting unit; and a control unit, wherein the control unit conveys the object to be conveyed to a specific position and, when the thermally reversible recording medium is not detected by the detecting unit, the laser light with a power level greater than or equal to a predetermined power level is prevented from being emitted from the laser light emitting unit.

Abstract: A laser rewriting apparatus positioned on one side or the other side of a conveyance path through which a to-be-conveyed object on which a thermoreversible recording medium is affixed is conveyed in a predetermined conveyance direction. The laser rewriting apparatus emits laser light to the thermoreversible recording medium and rewrites an image. The laser writing apparatus includes an image erasing apparatus that emits laser light to the thermoreversible recording medium and erases the image from the thermoreversible recording medium; and an image recording apparatus positioned on the predetermined conveyance direction downstream side of the image erasing apparatus and records a new image by emitting laser light to the thermoreversible recording medium. The image erasing apparatus and the image recording apparatus have the respective laser light emitting parts from which the laser light is emitted at ends on the same side with respect to the predetermined conveyance direction.

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 scanner includes: a light reflecting section having light reflectivity; a movable section which includes the light reflecting section and can be displaced; two link sections connected to positions of ends of the movable section, the positions facing each other; a supporting section supporting the link sections; and a displacement providing section turning the two link sections, wherein each link section includes a turnable drive section, and a shaft section connecting the movable section and the drive section and bending in a thickness direction of the movable section by turning of the drive section.

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: 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: Systems, apparatuses, and methods for pre-rendering image data for a plurality of scanning paths are described here. The method includes receiving image data including a plurality of scan lines for a top portion of an image page, pre-rendering the data for a first scanning path to generate a first data set, pre-rendering the data for a second scanning path to generate a second data set, determining an initial scanning direction, and selecting the first data set or the second data set responsive to said determining. Other embodiments may be described and claimed.

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: A method and a device for recording information within an information surface region in a data carrier, consisting of a carrier layer and a transparent plastic layer, by means of at least one laser beam of a point-like laser source wherein the laser beam is deflected via at least one deflection surface, in particular a mirrored surface before it impinges on the data carrier, wherein the at least one deflection surface is arranged in a region between the laser source and the data carrier and outside an intermediate region bounded by notional straight connection lines between the laser source and edge regions of the information surface region.

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 scanner includes a light source, a scan-deflecting portion including a resonance mirror to scan and deflect along a scan line, a plurality of light receiving sensors for synchronous detection provided on the scan line, a phase controller, an amplitude controller, and an offset controller. The phase controller obtains a difference between a true phase and a target phase, and generates a drive signal incorporating the difference between the true phase and the target phase. The amplitude controller incorporates the difference between a value equivalent of a true amplitude and a value equivalent of a target amplitude into the drive signal generated by the phase controller. The offset controller calculates an offset value by obtaining the difference between each of the time intervals, incorporates the difference between the offset value and a target offset value in the amplitude-controlled drive signal, and supply the drive signal to a driving device.

Abstract: An image forming apparatus includes a light beam output unit configured to output a light beam, a deflection unit for deflection scanning in a main scanning direction of a photosensitive member by reflecting the light beam from the light beam output unit, a timing information detection unit configured to detect timing information of the deflection scanning by the deflection unit, a calculation unit configured to calculate a correction amount of the main scanning direction for a next scan based on the timing information, a light beam modulation control unit configured to generate a light beam modulation signal based on image data and the correction amount, and a drive unit configured to drive the light beam output unit based on the light beam modulation signal.

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: An optical scanning system for a K station includes a resin scanning lens and three reflecting mirrors. Two reflectance ratios are calculated: one being the reflectance ratio of a luminous flux traveling toward the scanning start position of a drum-shaped photosensitive drum and the other being the reflectance ratio of a luminous flux traveling toward the scanning end position of the photosensitive drum. The magnitude relation between the two reflectance ratios is such that the reflecting mirror has an inverse magnitude relation to that of the other reflecting mirrors. Moreover, the difference is calculated between the largest value and the smallest value of the reflectance ratio, where the reflectance ratio depends on the angle of deviation of the polygon mirror. The reflecting mirror has the largest difference among the three reflecting mirrors.

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: Disclosed is an image forming apparatus capable of, and a method of, correcting a color registration error. The image forming apparatus corrects a color registration error by adjusting a scan start time of, and/or the distance in a sub-scanning direction between, multiple light beams that are scanned by a light scanning unit onto several photosensitive media.

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, 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 optical scanning apparatus includes an optical deflector that deflects a light beam at a substantially constant angular velocity and an optical system that condenses the deflected light beam onto a to-be-scanned surface thereby performing optical scanning of the to-be-scanned surface. The to-be-scanned surface is a surface of a latent image carrier having a charge generation layer that generates carriers and a charge transport layer. A driving unit drives the optical deflector at a scanning frequency at which exposure is attained in a state where the carriers generated at the charge generation layer of the latent image carrier substantially stay still.

Abstract: An image forming apparatus includes an optical scanning unit, a measurement unit, a first adjustment unit and a second adjustment unit. The optical scanning unit includes a plurality of light sources to emit laser beams, a single oscillating mirror deflector to deflect the laser beams used for scan processing in a main scanning direction, and a scan-focusing member to focus the deflected laser beams onto a plurality of photoconductors. The measurement unit measures a resonance frequency of the oscillating mirror deflector. The first adjustment unit adjusts a speed of the photoconductors in a sub-scanning direction. The second adjustment unit adjusts a magnification ratio of image data in the sub-scanning direction. The first adjustment unit and the second adjustment unit adjust the image magnification ratio of image data in the sub-scanning direction depending on the resonance frequency as measured by the measurement unit.

Abstract: An optical scanning device is configured in such a manner that, of four light beams for colors corresponding to cyan, magenta, yellow, and black, the number of folding mirrors disposed in the optical path of a light beam corresponding to an mage in yellow having the highest brightness and the lowest visibility is the greatest number, and further, the number of the folding mirrors disposed in the optical path of a light beam corresponding to an image in black having the lowest brightness and the highest visibility is the least number. It is thus possible to reduce unevenness in color in the color image resulting from the folding of light beams by the folding mirrors.

Abstract: Disclosed is an oscillator device that includes an oscillating system having a first oscillator, a second oscillator, a first torsion spring for connecting the first and second oscillators each other, and a second torsion spring being connected to the second oscillator and having a common torsional axis with the first torsion spring; a supporting system for supporting the oscillating system; a driving system for driving the oscillating system so that at least one of the first and second oscillators produces oscillation as can be expressed by an equation that contains a sum of a plurality of time functions; a signal producing system for producing an output signal corresponding to displacement of at least one of the first and second oscillators; and a drive control system for controlling the driving system on the basis of the output signal of the signal producing system so that at least one of amplitude and phase of the time function takes a predetermined value.