Abstract: An optical scanning apparatus scans a target surface with a light beam along a main scanning direction. The apparatus includes a light source, an optical deflector which includes a rotating multi-faceted mirror, each surface of the multi-faceted mirror acting as a reflecting surface to deflect the light beam from the light source, and a scanning optical system configured to guide the light beam deflected by the optical deflector to the target surface. An angle which is formed between the light beam toward the reflecting surface of the optical deflector and the corresponding reflecting surface and which includes a reflected light reflected from the corresponding reflecting surface is always obtuse.

Abstract: An image forming apparatus includes a temperature sensor detecting an operating ambient temperature of the polygon motor, and a controller controlling the polygon motor and the paper feed mechanism. If the temperature detected by the temperature sensor is equal to or greater than a preset temperature, the controller controls, before operation for giving a command to start image formation is performed, the polygon motor to rotate; increases, in response to the operation, a rotational speed of the polygon motor up to a rated speed; and controls the paper feed mechanism to start conveying a sheet of paper at a time when a period of time variable depending on the detected temperature has elapsed, the period of time being preset to be shorter as the detected temperature increases, in expectation of a time required for the rotational speed of the polygon motor to reach the rated speed.

Abstract: An image forming apparatus includes a polygon mirror configured to scan a photosensitive element with a writing beam; a developing unit configured to develop a latent image formed by the writing beam on the photosensitive element to form a visualized image corresponding to image data; a transfer unit configured to transfer the visualized image onto an image recording medium; a conveying unit configured to convey the image recording medium to a transfer position; and a writing control unit configured to control a rotation speed of the polygon mirror and a writing clock frequency of the writing beam so that a sub-scanning direction scale factor of the visualized image transferred onto the image recording medium having the second thickness is matched to a sub-scanning direction scale factor of the visualized image transferred onto the image recording medium having the first thickness.

Abstract: In a light beam emission apparatus, the height of an elastic member configured to fill a clearance between a laser element and a laser holder is longer than the distance from a start position of press fitting of the laser element to a surface of the laser holder with which the elastic member comes into contact.

Abstract: An image reading apparatus includes a LED that emits white light, a light guiding body, and a photoelectric conversion element. The light guiding body is disposed along the main scanning direction. The light guiding body includes an incident surface, a plurality of groove portions, an emission surface, and a scattering portion. The incident surface is formed on one end in a longitudinal direction, faces the light emitting surface of the LED that emits white light, and receives incident light that is emitted from the light emitting surface. The plurality of groove portions is formed on the incident surface and is formed concentrically to the center of the incident surface. The emission surface is formed along the main scanning direction. The scattering portion scatters light and includes a plurality of prisms. The scattering portion is opposed to the light emitting surface and is disposed along the main scanning direction.

Abstract: An optical writer includes a housing, a light source, a deflector, and a plurality of optical elements. The housing includes a plurality of surfaces, one of which includes a substantially flat portion having an opening formed therein and a curved portion curved in the shape of an arc of a circle in cross-section. The light source is enclosed within the housing and projects light through the opening and onto a target. The deflector is enclosed within the housing and deflects the light projected from the light source in a main scanning direction. The plurality of optical elements is enclosed within the housing and directs the light deflected by the deflector onto the target.

Abstract: Provided is a color image forming apparatus which has photosensitive members and a light irradiation unit irradiating at least one of the photosensitive members, the color image forming apparatus including: a laser driving unit causing the light irradiation unit to emit light of a light amount at a first emission level for printing when exposing an image portion and to emit light of a light amount at a second emission level for weak emission when exposing a non-image portion; an acquiring unit acquiring information of remaining lifetime of each of the photosensitive members; a first light intensity adjusting unit adjusting a first drive current to emit light at the first emission level; and a second light intensity adjusting unit adjusting a second drive current to emit light at the second emission level, the second light intensity adjusting unit changing the second drive current in accordance with the information.

Abstract: An optical writer includes a light source, an optical part, a housing, and an elastically deformable retainer. The light source projects light against a target. The optical part is disposed on a light path between the light source and the target. The housing houses the light source and the optical part. The elastically deformable retainer is detachably fixed to the housing and includes a plurality of contact portions on an inner surface of the retainer to hold the optical part. The retainer elastically deforms to separate at least one of the contact portions from other contact portions to hold the optical part by the plurality of contact portions.

Abstract: Compensation is performed for nonuniformity in a printer. The printer has a photoreceptor and a print head with a plurality of different light sources, each light source capable of producing a plurality of different levels of light. A plurality of stored gain control signals for each light source are related to the light output of that light source. Print job data includes screened pixel levels and a halftone screen specification. The stored gain control signals are adjusted based on the halftone screen specification. The screened pixel levels are modified using the adjusted gain control signals to provide engine pixel levels. Those levels are provided to corresponding light sources to expose the photoreceptor in respective pixel areas with light corresponding to the compensated pixel levels.

Abstract: A light-emitting chip includes plural light-emitting thyristors having a first anode terminal, a first cathode terminal, and a first gate terminal, plural setting thyristors having a second anode terminal, a second cathode terminal, and a second gate terminal and setting the absolute value of a threshold voltage of each light-emitting thyristor to be smaller than that in an OFF state, plural transmission thyristors having a third anode terminal, a third cathode terminal, and a third gate terminal and setting the absolute value of a threshold voltage of each setting thyristor to be smaller than that in an OFF state, plural first connecting resistors connecting the first gate terminals and the second gate terminals, plural second connecting resistors connecting the second gate terminals and the third gate terminals, and plural third connecting resistors connecting the first gate terminals to a power supply line supplied with a source potential.

Abstract: An image forming apparatus can include exposure units having light emitting elements, a forming unit which has a photoreceptor exposed by the exposure unit and forms an image on a body to be transferred, an acquisition unit for acquiring a tilt angle error between an approximated line of a first pattern formed by the forming unit based on exposure of one exposure unit and an approximated line of a second pattern formed by the forming unit based on exposure of another exposure unit, and an adjustment unit for adjusting at least one of a light emitting time lag of the light emitting elements and an angular error of the exposure units between the one exposure unit and the other exposure unit to restrain the tilt angle error.

Abstract: A light-emitting thyristor includes a substrate, a first semiconductor multi-layered mirror of a first conductivity type that is formed on the substrate, a gate layer that is formed on the first semiconductor multi-layered mirror by stacking a plurality of semiconductor light-emitting layers having different peak values of an emission wavelength, and a second semiconductor multi-layered mirror of a second conductivity type that is formed on the gate layer.

Abstract: An image of a color misregistration detection pattern is formed, and the amount of color misregistration is detected by reading of the pattern image. The amount of color misregistration detected by a detecting unit and the delay time from the time when image data is requested to the time when the image data is output are stored. The color misregistration is corrected based on the stored delay time and amount of color misregistration.

Abstract: A scanning optical apparatus includes: two light source units; a deflecting unit for deflecting two light beams for scanning; and two imaging optical systems disposed corresponding to the two light beams, in which: the two imaging optical systems form images of the two light beams on photosensitive members of different hues; the two imaging optical systems are disposed to be opposed with respect to the deflecting unit in a sub-scanning cross section; and a reflectance of a first reflecting optical element disposed in an optical path between the photosensitive member and the deflection surface passed by a light beam corresponding to an image of a hue having low brightness is lower than a reflectance of a second reflecting optical element disposed in an optical path between the photosensitive member and the deflection surface passed by a light beam corresponding to an image of a hue having high brightness.

Abstract: An optical writing device performs writing on an exposure region of a light writing display medium. The optical writing device includes an accommodation section, a light irradiation member, a voltage application member, a medium conveyance member and control means. The control means performs control for: applying voltage with the voltage application member to a first medium; the light irradiation member irradiating the light bearing image information and moving a first distance in the first direction over the first medium; the voltage application member applying voltage to a second medium; the light irradiation member irradiating the light for image erasure onto the second medium and moving a second distance in the second direction over the second medium; and, simultaneously the movement of the light irradiation member in the second direction, the medium conveyance member conveying the first medium.

Abstract: A light beam scanning device capable of suppressing lowering of accuracy of light amount control when scanning a photosensitive member using light beams. A semiconductor laser has light emitting elements for emitting respective light beams. A polygon mirror deflects the light beams such that each light beam scans a photosensitive member in a predetermined direction. A photodiode sensor is disposed where the light beams enter. A CPU controls the light amount of each light beam based on an output from the sensor. The first and second light emitting elements are arranged such that respective light beams therefrom are adjacent to each other in the direction and there is time during which both the light beams enter the sensor. The CPU executes the control for the first and second light emitting element, at receptive different cycles of scanning of the light beams.

Abstract: According to one embodiment, an optical scanning device includes a mirror with one end portion fixed as a fulcrum which includes at least a first, a second and a third surface along the longitudinal direction and reflects a scanning beam, a first support portion to support the first surface at the other end portion of the mirror, a second support portion to support the second surface of the mirror, whose position conforms to a position of the first support portion in the longitudinal direction of the mirror, a drive portion to drive the second support portion to be moved, and a third support portion to support the mirror by pressing the third surface of the mirror which is supported by the first support portion and the second support portion.

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: A light emission control device images an electrostatic latent image on a photosensitive element by a plurality of light emitting elements corresponding to a line in a second direction perpendicular to a first direction which is a rotational direction the photosensitive element. The light emission control device includes: a detecting unit that detects a rotational position of the photosensitive element, in the first direction, corresponding to a line in the second direction; an acquiring unit that acquires a distance between the light emitting elements and the rotational position of the photosensitive element in the first direction detected by the detecting unit; and a control unit that controls light emission by the light emitting elements according to the distance acquired by the acquiring unit and corrects a fluctuation in a density of a visible image converted from the electrostatic latent image.

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

Abstract: An optical writing device forms an electrostatic latent image on a photosensitive element by a connected light source controlled by a light source control circuit that includes: a pixel data output unit; a pixel data correcting unit that corrects a skew between main scanning line of electrostatic latent image and photosensitive element and a local deviation of the electrostatic latent image on the main scanning line, and outputs pixel data; a pattern generating unit that outputs pixel data for forming a predetermined pattern in an electrostatic latent image; a first light source control unit for causing a first light source, that needs correction of the local deviation, to emit light; a second light source control unit for causing a second light source, that does not need correction of the local deviation, to emit light; and a switch that switches between a first transmission status and a second transmission status.

Abstract: A light source control circuit of an optical writing device, admitting connection of light sources and forming an electrostatic latent image on a photosensitive element by controlling a connected light source, includes: a skew correction unit that corrects a skew of a main scanning line of an electrostatic latent image formed by the light source relative to the photosensitive element; a pattern generating unit that outputs image data for forming a predetermined pattern in an electrostatic latent image; a local deviation correction unit that corrects a local deviation of an electrostatic latent image formed by the light source on the main scanning line by acquiring image data processed to form the pattern and by performing a predetermined process; a light source control unit that causes the light source to emit light based on image data in which the local deviation has been corrected; and a setting value input unit.

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 exposure device includes light emitting elements, a driving circuit, an image-signal connector, a power connector, and an adjustment-control-signal connector. The light emitting elements emit light which an exposure target member is exposed to. The driving circuit performs one of first and second drive operations. The image-signal connector has terminals connected to core wires of an image-signal cable, and relays, to the driving circuit, image signals transmitted through the image-signal cable. In the image-signal cable, the core wires are arranged at a first pitch. The power connector has terminals arranged at a pitch wider than the first pitch, and relays, to the driving circuit, power transmitted through power cables. The adjustment-control-signal connector has terminals arranged at a pitch wider than the first pitch, and relays, to the driving circuit, light-amount adjustment control signals transmitted through adjustment-control-signal cables.

Abstract: A method of registering a print between print stages in a printing system is provided. The method comprises: printing a first part of a digital image on a substrate with a first print engine, wherein the first part of the digital image includes a plurality of reference features; scanning image content on the substrate as it is readied for the second print engine; determining the actual positions of the reference features; using the actual positions of the reference features to determine desired adjustments for the second part of the digital image; applying electronic registration according to the desired adjustments to modify image content of the second print to be aligned with content already on the substrate; and printing a second part of the digital image on the substrate.

Abstract: A drive device for outputting a drive signal for driving a plurality of light emitting elements time-divisionally, the drive device includes a plurality of input terminals receiving input of a drive control signal for the light emitting elements, and a plurality of output terminals connected to the light emitting elements, for outputting the drive signal based on the drive control signal input into the input terminals, in which the input terminals and the output terminals are arranged substantially in a line.

Abstract: An image forming apparatus which forms an image by forming an electrostatic latent image on a photosensitive member with a laser beam, developing the electrostatic latent image with a developer to obtain a developer image, and transferring the developer image to a sheet, the image forming apparatus including: a light source which outputs the laser beam for exposing the photosensitive member; a PLL circuit which generates a multiplied clock that is obtained by multiplying a reference clock; a pulse-width modulating circuit which outputs a pulse-width-modulated signal based on image data and the multiplied clock in order to drive the light source; and a CPU which obtains image data to be input to the pulse-width modulating circuit and, when it is unnecessary to output the pulse-width-modulated signal based on the obtained image data, controls the PLL circuit so as not to generate the multiplied clock.

Abstract: An image forming apparatus including: a light scanning portion that lights a plurality of beams, and scans a surface to be scanned of an image carrier to form an electrostatic latent image; a detection portion that detects at least one lighted beam; an abnormality detection portion that transmits data to the light scanning portion via a transmission-line, causes the light scanning portion to light a beam, and detects abnormality of the transmission-line based on the detected beam; and a setting portion that sets a number of beams to be lighted in the case of the formation of the electrostatic latent image so that an amount of light of the detected beam in the case of abnormality detection of the transmission-line is equal to or more than a minimum amount of light of the detected beam in the case of the formation of the electrostatic latent image.

Abstract: An image forming apparatus having: a light source for emitting a beam; a deflector for deflecting the beam; a light receiving element for receiving the beam and generating a detection signal; a converter for converting electric potentials of the detection signal into data values and generating time data associated with the data values; and a first calculator for calculating a position of center of the beam from the data values and the time data.

Abstract: An embodiment of the image processing apparatus for controlling the lighting of a line head that is driven with binary data and performs exposure with subline lighting to thereby form images, includes: a subline generating unit that generates a plurality of sublines from a same image data; an inclination correcting unit that exposes the generated sublines so as to generate correction image data used to correct an inclination of an exposure position; a gradation control unit that controls the lighting of sublines based on the correction image data generated by the inclination correcting unit to express gradation; and a light intensity correction unit that corrects and controls the light intensity based on the correction image data generated by the inclination correcting unit, wherein an output of the gradation control unit and an output of the light intensity correction unit are input into the line head in parallel.

Abstract: An optical writing device is provided with a pixel information acquiring unit that acquires multilevel pixel information in which one pixel is expressed in multilevel scales, a line pixel information storing unit that stores the multilevel pixel information for each main scanning line, a light emission control unit that optically exposes the photosensitive element by controlling the binary light source on the basis of the multilevel pixel information. The photosensitive element is exposed to the binary light source with a period corresponding to N-fold in a sub scanning direction resolution of the multilevel pixel information, wherein N is a positive integer, so that the N times exposures corresponds to an exposure for one pixel in the original resolution. The switch on/off statuses of the binary light source are controlled in the N times exposures for each pixel, on the basis of lighting rate information for converting the multilevel scales into a lighting rate in the N times exposures.

Abstract: A rotational polygon mirror includes a plurality of reflection surfaces that rotate with respect to a rotation axis, wherein each of the reflection surfaces has a convex shape and a cross-sectional profile perpendicular to the rotation axis having at least two inflection points.

Abstract: In an optical scanning device, a beam outputted from a light source is deflected by an optical deflector, and an object to be scanned (for example, a photosensitive drum) is scanned by the deflected beam. The optical scanning device is provided with a light source that outputs a beam, an aperture provided with an opening that shapes the beam outputted from the light source, a reducing optical portion that reduces the beam shaped by the aperture, and a collimator, which is arranged within an interval from the light source to the reducing optical portion, and makes the beam parallel. The reducing optical portion outputs the incoming beam as a parallel beam. The aperture and the reducing optical portion are arranged within an interval from the light source to the optical deflector.

Abstract: A semiconductor device, a print head comprising the semiconductor device and an image forming apparatus comprising the print head are supplied which are able to reduce cost through miniaturizing element size and minishing chip area. The semiconductor device comprises a plurality of light emitting elements; and a shift register circuit that has output terminals respectively corresponding to the plurality of light emitting elements and stores emitting-light instruction data of the light emitting elements, wherein each light emitting element has a first electrode and a second electrode to that lightening electricity of the light emitting element flows, and a third electrode for controlling the light emitting element whether to emit light, the output terminals of the shift register circuit are respectively connected with the third electrodes of the corresponding light emitting element.

Abstract: An optical device includes: a light source including a plurality of light emitting spots that output laser beams, respectively; a separating unit that separates each of the laser beams output from the plurality of light emitting spots into a monitor beam and a scanning beam; a light-quantity measuring unit that measures a light quantity of the monitor beam; a storage unit in which respective drive currents with which the plurality of light emitting spots of the light source output a prescribed light quantity of laser beams are stored in advance; a light-source control unit that drives the light source with the drive currents stored in the storage unit and causes the plurality of light emitting spots to output the laser beams; and a determining unit that determines whether the light source operates properly on the basis of the light quantity measured by the light-quantity measuring unit.

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: An exposure device configured to perform exposure using a plurality of light beams and capable of stabilizing image density without increasing circuit size. The exposure device has a first light source for emitting a first light beam and a second light source for emitting a second light beam. The exposure device exposes a photosensitive drum such that areas exposed to the respective first and second light beams at least partially overlap each other. A first drive current having a predetermined value and a second drive current are supplied to the respective first and second light sources. A photodiode detects the intensities of the respective first and second light beams or the sum of the intensities. The second drive current is controlled based on a detection result from the photodiode such that the sum of the intensities becomes equal to a target intensity.

Abstract: An image forming apparatus that forms a color image includes: a sensor that detects a density of an image formed on the transfer body; a density adjusting unit that forms a density test pattern on a transfer body and that adjusts process parameters such that a density of the density test pattern on the transfer body falls within a predetermined range of a reference density; and a gradation adjusting unit that forms a gradation test pattern on the transfer body and updates the gradation correction data such that a density for every gradation of the gradation test pattern on the transfer body falls within a predetermined range of a reference gradation density acquired and stored beforehand. The gradation adjusting unit updates the gradation correction data subsequently after the density adjusting unit adjusts the density of the density test pattern.

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

Abstract: The present invention provides a support structure, which includes: a housing configured to store an optical element; a support unit configured to support the housing; a positioning element configured to position the housing with respect to the support unit; an vibration-proof element configured to proof transmission of vibration from the support unit to the housing; and an extension portion extending from the housing toward the support unit. The support unit includes a first surface configured to define an opening into which the extension portion is inserted. The positioning element supports and positions the extension portion in the opening so that the extension portion is apart from the first surface. The vibration-proof element is disposed between the first surface and the extension portion.

Abstract: An optical scanning device includes a third f? lens, an adjusting bar, a pressing portion, a columnar member, and a movement restraining section. The adjusting bar is disposed parallel with a longitudinal direction of the third f? lens and has projections which are capable of pressing against the third f? lens at plural points in the longitudinal direction of the third f? lens. The pressing portion and the columnar member press the adjusting bar against the third f? lens. The movement restraining section is configured to set the pressing portion and the columnar member in a first state in which the pressing portion and the columnar member are movable in a direction parallel with the longitudinal direction of the third f? lens or in a second state in which the pressing portion and the columnar member are restrained from moving.

Abstract: The optical scanning device performs a first control operation that when the scanning speed of a deflector is stabilized, a light source is turned on, and when a detection signal is received from a photodetector, the light source is turned off while starting counting the scanning period in the main scanning direction from zero; a second control operation that when the count reaches a first value, the light source is turned on, and when a detection signal is received, the light source is turned off while starting counting the scanning period; and a third control operation that when the count reaches a second value, the light source is turned on, and when a detection signal is received, the light source is turned off while starting counting the scanning period, followed by repetition of the third control until scanning is completed.

Abstract: An optical scanner includes a third f-theta lens, an eccentric cam, an attaching portion, a first supporting member, a second supporting member and a spring. A distance between a face opposed to the first side-face of the third f-theta lens in the first supporting member and a face opposed to the second side-face of the third f-theta lens in the second supporting member is set to be longer than a distance of the third f-theta lens in its lateral direction. The spring is disposed opposed to the first side-face or the second side-face, and presses the third f-theta lens so that the third f-theta lens is in contact with the eccentric cam and either of the first supporting member and the second supporting member.

Abstract: An image of a color misregistration detection pattern is formed, and the amount of color misregistration is detected by reading of the pattern image. The amount of color misregistration detected by a detecting unit and the delay time from the time when image data is requested to the time when the image data is output are stored. The color misregistration is corrected based on the stored delay time and amount of color misregistration.

Abstract: According to one embodiment, an optical head includes a light emitting substrate emitting light and a heat sink including a contact section in contact with an area different from a light emitting area of the light emitting substrate and a deformable section separated from the light emitting substrate and deformed according to thermal expansion of the light emitting substrate.

Abstract: According to one embodiment, an optical head includes a light emitting substrate emitting light and allow light of specific wavelength to pass; a mounting base to which the light emitting substrate is fixed and which includes a groove formed in an area overlapping the light emitting substrate; an adhesive filled in the groove of the mounting base and cured by receiving the light having the specific wavelength; and a lens condensing the light emitted from the light emitting substrate.

Abstract: An optical writer includes a scanning part causing a light beam from a light source to perform scanning on a photosensitive body; an image information obtaining part obtaining image information of an image; a dithering information obtaining part obtaining dithering information of the image; a pixel clock generating part generating a pixel clock signal; and a light emission control part to control the light source based on the image information in accordance with the pixel clock signal. The pixel clock generating part modulates the clock frequency of the pixel clock signal in accordance with phase shift information for correcting a change in the speed of the scanning on main scanning lines on the photosensitive body, and determines the timing of modulating the clock frequency based on the dithering information on a main scanning line basis so that the timing of modulating the clock frequency differs between the main scanning lines.

Abstract: An optical device is provided with an optical unit for forming an optical path of a laser beam, and a housing defining an internal space for accommodating the optical unit. The housing includes a partition for dividing the internal space into a first space and a second space. The optical unit includes a sensor arranged in the first space to detect the laser beam in the second space, a mirror arranged in the second space to define a direction of the optical path, a drive source arranged in the second space to operate the mirror to adjust the direction of the optical path, a power line for supplying power to the drive source, and a signal line for transmitting an output signal of the sensor. The signal line extends in the first space and the power line extends in the second space.

Abstract: An image forming apparatus includes a light source that emits light beams for scanning a photoconductive element and for image forming of image data, a storage unit that stores a correction amount of a turn-on time of the light source associated with a preset turn-on pattern of the light beams, an acquiring unit that compares a pattern of the image data with the turn-on pattern, so as to acquire the correction amount corresponding to the pattern of the image data which is associated with the turn-on pattern, from the storage unit; and a light source controller that controls turn-on of the light source by a turn-on time corrected with acquired correction amount.

Abstract: With an electrophotographic image forming apparatus which forms an image by using a plurality of light emitting elements, since a photodiode (PD) is disposed in the vicinity of the plurality of light emitting elements and, therefore, the PD also receives a laser beam emitted only by a bias current during the APC period, setting a bias current based on a result of light amount detection by the PD does not result in a bias current setting with sufficient accuracy. To solve this issue, an electrophotographic image forming apparatus forms an electrostatic latent image pattern on a photosensitive drum, and controls the value of the bias current set for a first light emitting element based on the potential of the electrostatic latent image pattern detected by a potential sensor so that the value of the bias current for the first light emitting element comes close to a minimum value of the drive current supplied to the first light emitting element to form the electrostatic latent image.