Abstract: An image forming apparatus includes an image carrier, a transfer unit, and a control unit. The image carrier has a surface to bear a toner image thereon. The transfer unit has a transfer member to transfer the toner image onto a recording sheet conveyed in a conveyance direction for trailing-end borderless image formation and duplex image formation. The transfer unit is configured to form the toner image on the recording sheet without forming a margin at a trailing end of the recording sheet in the conveyance sheet in the trailing-end borderless image formation. The transfer unit is configured to form the toner image on front and back faces of the recording sheet in the duplex image formation. When a width of the toner image formed in a borderless image area of the recording sheet in the trailing-end borderless image formation is smaller in a direction perpendicular to the conveyance direction than a threshold value, the control unit permits the duplex image formation.

Abstract: An image forming apparatus includes a power source to output a voltage having an alternating waveform to transfer a toner image from an image bearing member to a recording medium. A time-averaged value (Vave) of the voltage has a polarity in a transfer direction, in which the toner image is transferred from the image bearing member to the recording medium, and an absolute value of the time-averaged value is greater than a midpoint value (Voff) of the voltage intermediate between a maximum value and a minimum value of the voltage. As a roughness of the recording medium increases, a duty ratio (Duty) expressed by A/(A+B) is reduced, where A is an area of the waveform of the voltage in a return direction opposite the transfer direction relative to the midpoint value in one cycle and B is an area in the transfer direction relative to the midpoint value.

Abstract: In a method for printing a recording medium, an object type of image elements to be printed is determined for a corresponding print page using digital data. In generation of a bitmap for generation of a latent image for a first print process or a second print process, dependent on the object type image points are adapted in a direction of at least one main axis corresponding to an expected shrinkage. The recording medium is printed with a first toner image in a first print process. The first toner image is fixed on the recording medium in the fixing device where the recording medium shrinks along said at least one main axis. In the second print process, a second toner image is applied on the same recording medium in the direction of the main axis in a form compressed relative to that of the first print process.

Abstract: A transient document management system can include a transient document identifier placement module for placing a transient document identifier on a transient physical document, a transient document information retrieval module for extracting information from the transient physical document, and a transient document processing module for performing data processing based on the information extracted from the transient physical document.

Abstract: A fixing device includes a fixing belt; a pressing rotary body disposed outside a loop formed by the fixing belt; a nip formation pad disposed inside the loop formed by the fixing belt and pressed against the pressing rotary body via the fixing belt to form a fixing nip between the pressing rotary body and the fixing belt through which a recording medium bearing a toner image is conveyed. The nip formation pad includes a protrusion disposed downstream from the fixing nip in a conveyance direction of the recording medium and protruding toward the pressing rotary body without contacting the pressing rotary body. The fixing device further includes a pressing rotary body mover to contact and move the pressing rotary body bidirectionally in the conveyance direction of the recording medium to move the fixing nip toward and away from the protrusion.

Abstract: The image forming apparatus includes a photosensitive drum, developer bearing members to develop a latent image formed on the photosensitive drum into a toner image while bearing developer, a secondary transfer roller to transfer the toner image to a sheet, an operation apparatus to which smoothness of the sheet having the toner image transferred, and a CPU which controls to decrease fog elimination potential difference between non-image portion potential of the photosensitive drum and direct current component potential of bias applied to developer bearing members in a case that smoothness inputted to the operation apparatus is information that the smoothness of the sheet having the toner image formed is equal to or higher than a predetermined smoothness as compared to a case of being lower than the predetermined smoothness.

Abstract: An image forming apparatus includes (i) a feeding portion; (ii) an image forming portion; (iii) a fixing portion, wherein the fixing portion includes: (iii-i) a rotatable member; (iii-ii) an exciting coil configured to cause the rotatable member to generate heat by electromagnetic induction heating; (iii-iii) a magnetic flux suppressing member configured to suppress a part of magnetic flux acting from the exciting coil to the rotatable member; and (iii-iv) a motor for moving the magnetic flux suppressing member depending on a width size of the sheet; and (iv) a controller configured to variably control a feeding interval of the sheet by the feeding portion so that a number of times of movement per unit time of the magnetic flux suppressing member is not more than a predetermined value when image formation of a plurality of sheets different in width size is continuously effected.

Abstract: If the elapsed time since a sheet was stored in a sheet storage unit is less than or equal to a threshold value, control is performed such that the sheet is heated by a fixing unit before an image is transferred to the sheet, and if the elapsed time since the sheet was stored in the sheet storage unit exceeds the threshold value, control is performed such that processing for heating the sheet with the fixing unit before the image is transferred to the sheet is not performed.

Abstract: An image heating apparatus includes: a rotatable heating member for heating a toner image formed on a recording material by using a toner containing a parting agent; an exciting coil for causing the rotatable heating member to generate heat by electromagnetic induction heating; a magnetic flux suppressing member for suppressing a part of magnetic flux acting from the exciting coil onto the rotatable heating member; a moving mechanism for moving the magnetic flux suppressing member depending on a width size of the recording material; a motor for operating the moving mechanism; and an executing portion capable of selectively executing an operation in a first mode in which a first current is supplied to the motor and an operation in a second mode in which a second current larger than the first current is supplied to the motor.

Abstract: An image forming apparatus for detecting surface conditions of a recording sheet on which an image is formed, includes a light source configured to emit a first light beam and a second light beam, an image capture device configured to capture a first image of a surface of the recording sheet illuminated with the first light beam and a second image of the surface of the recording sheet illuminated with the second light beam. A first straight line including a ray in a center of the first light beam and a second straight line including a ray in a center of the second light beam intersect with each other, when each straight line is projected onto the surface of the recording sheet, and a detection device configured to detect information about the unevenness on the surface of the recording sheet based on the first image and the second image.

Abstract: An image forming apparatus includes an intermediary transfer member having an elastic layer; a toner image forming portion for forming a toner image for an image to be carried on the intermediary transfer member; a transfer member, which presses the intermediary transfer member, for transferring the toner image for the image from the intermediary transfer member onto a recording material; a pressing mechanism capable of changing pressure applied from the transfer member to the intermediary transfer member; and a controller for controlling the toner image forming portion so that a length of the toner image for the image on the intermediary transfer member with respect to a rotational direction of the intermediary transfer member is decreased with an increase of the pressure.

Abstract: An image formation device includes a receiving section, a formation section, a fixing section, a switching section, and a controller. The receiving section receives image formation data including image data, and sheet data which includes designations of a sheet and a corresponding fixing pressure. The formation section forms a toner image on the sheet. The fixing section fixes the toner image on the sheet. The switching section switches the fixing pressure between a first or second fixing pressure. When the fixing pressure is switched to the second fixing pressure and the fixing pressure designated by the sheet data is the first fixing pressure, the controller performs a mandatory image formation that includes a low-speed control that conveys the sheet at a speed lower than that for the first fixing pressure, and/or a toner suppression control that performs image formation with a smaller amount of toner than in normal.

Abstract: A control apparatus configured to control an image forming system, in forming a transparent image so as to cover color images fixed on a sheet, applies a transparent toner on an area on which an image can be formed and which is other than an area that a user desires to increase the glossiness thereof.

Abstract: A fixing device for fixing a toner image on a recording medium includes a fixing roller to rotate in a predetermined direction of rotation, a pressing roller to rotate and contact an outer circumferential surface of the fixing roller to form a nip between the pressing roller and the fixing roller through which the recording medium bearing the toner image passes to fix the toner image by heat and pressure, a pressing lever to hold both lateral end portions of the pressing roller, and a cam disposed on a camshaft, to rotate the pressing lever to change the position of the pressing roller. Rotation of the cam in a first, pressing direction enables the pressing roller to pressingly contact the fixing roller. Rotation of the cam in a second direction opposite the pressing direction enables the pressing roller to separate from the fixing roller.

Abstract: In an image forming apparatus that separates a thin recording material by pushing up a transfer belt, if a position where a thick recording material separates from the transfer belt is far from a leading end of a recording-material guide, conveyability of the separated thick recording material after separation becomes stable. A stretching member is provided downstream of a push-up means and upstream of the recording-material guide in a recording-material conveying direction, and the stretching member separates a thick recording material from the transfer belt.

Abstract: An image forming apparatus includes a toner image forming device that forms a toner image by using at least one of a plurality of toners that include a color toner and a first transparent toner; an intermediate transfer body to which the toner image is transferred; a second transfer unit that transfers the toner image to a recording medium; and a controller that acquires characteristic information that represents a characteristic of in-plane resistance variation of a currently-used recording medium before the toner image forming device forms the toner image, and if the characteristic information indicates that the in-plane resistance variation of the currently-used recording medium is larger than a predetermined value, controls the toner image forming device so that the toner image forming device forms a transparent toner image in such a way that a color toner image is superimposed on the transparent toner image on the intermediate transfer body.

Abstract: An image forming apparatus includes a rotatable image bearing member for bearing a toner image; a transfer member constituting a transfer portion for transferring the toner image formed on the image bearing member onto a recording material; a voltage source for applying, to the transfer member, a voltage in the form of superimposed DC voltage and AC voltage; a controller for controlling the voltage source such that a duty ratio of the AC voltage is changed in accordance with a kind of the recording material; and an executing portion for executing an operation in an image forming mode in which the toner image is transferred from the image bearing member onto the recording material with the duty ratio controlled by the controller.

Abstract: A recording material detection apparatus having a detecting device configured to detect a surface state of a recording material on the basis of reflected light from a surface of the recording material includes a reference surface to be irradiated with light from a light source, the detecting device includes a light-shielding portion configured to control conditions for detecting information relating to the surface state of the recording material on the basis of the reflected surface from the reference surface, and cover a portion of the reference panel other than the reference surface so as to prevent the light from the light source from being reflected from the portion of the reference panel other than the reference surface and being received by the light-receiving unit.

Abstract: An approach is provided for pairing a fuser assembly with a media size and for electronically labeling the fuser assembly for use with the media size. The approach involves causing, at least in part, a fuser assembly having a memory to be tagged with an identifier related to a corresponding media size, the identifier being stored in the memory. The approach also involves determining a media size associated with a print job to be run by a printing system. The approach further involves determining the identifier of an installed fuser assembly. The approach additionally involves causing, at least in part, a comparison between the determined media size associated with the print job and the identifier of the installed fuser assembly to determine if a conflict exists.

Abstract: An approach is provided for selectively loading a cleaning web useful in printing based on various media attributes of a media that is to be processed by a fuser unit. The approach involves determining one or more media attributes associated with a media to be processed by a fuser unit, the fuser unit comprising one or more heat rolls. The approach also involves determining at least one of the one or more media attributes meets a predetermined criteria. The approach further involves causing, at least in part, a cleaning web to contact at least one of the one or more heat rolls based, at least in part, on the determination that one or more media attributes meets the predetermined criteria.

Abstract: There is provided an image forming apparatus including: a forming unit that forms a toner image according to image information for an image to be formed on a sheet; a fixing unit that fixes the toner image formed on the sheet; a switching unit that switches a fixing pressure of the fixing unit by an operation; a stopping unit that, when the fixing pressure is switched to fix at a second fixing pressure lower than a predefined first fixing pressure, stops conveying a final sheet before the final sheet is fed after being fixed; and an instructing unit that, when the stopping unit stops conveying the final sheet, instructs switching to the first fixing pressure.

Abstract: A recording medium imaging apparatus includes an irradiation unit configured to irradiate a recording medium with light, an imaging unit configured to capture reflected light which is irradiated by the irradiation unit and reflected by the recording medium as a surface image, and a reference plate which includes a background that reflects light irradiated by the irradiation unit, and a mark that has a different reflectance ratio to the background, wherein the imaging unit captures reflected light reflected by the reference plate as a surface image and includes a control unit that determines a type of the recording medium based on the surface image of the reference plate and the surface image of the recording medium.

Abstract: This invention allows completely cutting power supply to a circuit that has become dysfunctional because of blowout of a fuse. To accomplish this, a circuit includes a fuse connected to one supply line of an AC power supply, a switching unit connected to the other supply line of the AC power supply, a detection unit configured to detect blowout of the fuse, and a control unit configured to turn off the switching unit when the detection unit detects blowout of the fuse.

Abstract: An image forming apparatus according to an embodiment includes a charging device that charges an electric charge to an image carrier, a developing device supplying the image carrier with a developer, and a transfer device that transfers a toner image formed on the image carrier by a developing device onto a recording medium. The apparatus further includes a control unit, discriminates between a first mode of forming an image on a first recording medium of a first thickness and a second mode of forming an image on a second recording medium thinner than the first recording medium to control a developing contrast electric potential, and controls a magnitude of the developing contrast electric potential in the second mode so as to be lower than the first mode.

Abstract: An image forming apparatus includes a fixing device that is attachable to and detachable from an apparatus body and fixes a developer image onto a recording medium; a setting unit that is provided in the fixing device and in which a size of a recording medium to be used in the fixing device is set; an acquiring unit that is provided in the apparatus body and acquires size information of a recording medium onto which the developer image is to be fixed; a determining unit that compares the size of the recording medium set in the setting unit with the size of the recording medium acquired by the acquiring unit so as to determine whether or not a fixing process is performable by the fixing device; and a notifying unit that at least provides notification of a negative determination result obtained by the determining unit.

Abstract: An image heating apparatus includes: (i) an endless belt; (ii) a driving member; (iii) a heater including: (iii-i) a substrate; (iii-ii) a resistor; (iii-iii) a first electroconductive portion electrically connected to the resistor in a widthwise end side; and (iii-iv) a second electroconductive portion electrically connected to the resistor in another widthwise end side; and (iv) a selector for selecting one of first and second electric energy supply paths. The first electric energy supply path is electrically connected to a region of the first electroconductive portion at a longitudinal central portion of the resistor and to a region of the second electroconductive portion in at the longitudinal central portion. The second electric energy supply path is electrically connected to a region of the first electroconductive portion at a longitudinal end portion of the resistor and to a region of the second electroconductive portion at another longitudinal end portion.

Abstract: An image forming apparatus includes: an image carrier; a toner image forming unit that forms a toner image on the image carrier; a transfer unit that transfers the toner image on the image carrier to a transfer target having ridges and valleys on a surface thereof; an adjusting unit that adjusts a ratio of A/B, where A is a transfer ratio [%] from the image carrier to a valley portion of the transfer target while B is a transfer ratio [%] from the image carrier to a ridge portion of the transfer target, based on an adjustment input by a user; and a control unit that controls a transfer condition of the transfer unit based on the ratio of A/B adjusted by the adjusting unit.

Abstract: An image forming apparatus includes: a transfer belt that is stretched on a plurality of support rollers including a backup roller in a loop-like manner and has an outer surface for carrying thereon a toner image; a transfer roller that is brought into pressurized contact with the backup roller across the transfer belt and forms a transfer nip with the transfer belt; a restriction member that is placed upstream of a transfer nip in a sheet conveying direction so as to be switchable between a first state in which the restriction member is brought closer to an inner surface of the transfer belt and a second state in which a distance of the restriction member from the inner surface of the transfer belt is larger than that in the first state; and a control section that switches a state of the restriction member.

Abstract: An inverse mask image generating printer and printer module are provided. In one aspect, an inverse mask image generating module has an input adapted to receive the image data for an image to be printed said image data having color data for a first set of colors used in a first color model; an inverse mask image processor generating an inverse mask image using color data for one of the first set of colors; and an output providing the inverse mask image for use by a print engine. The inverse mask image is generated based upon the color data for a selected one of the first set of colors so that the inverse mask image can be generated without first determining color separation toner images that define amounts of color toner to be applied to form the elements of the image.

Abstract: An image forming apparatus includes a transfer bias output device and an information receiving device. The transfer bias output device outputs a transfer bias including a superimposed bias composed of an AC bias superimposed on a DC bias to form a transfer electric field in a transfer nip between an image bearing member bearing a toner image and a nip forming member, to transfer the toner image onto a recording medium in the transfer nip. A controller operatively connected to the information receiving device and the transfer bias output device causes the transfer bias output device to change a target output of a peak-to-peak voltage of the AC bias based on information received by the information receiving device that affects transfer of the toner image and to reduce a target output of the DC bias as the target output value of the peak-to-peak voltage of the AC bias increases.

Abstract: An image inspecting apparatus includes a first light illuminating unit irradiating a measured object on which an image is formed with light from an inclined direction; a second light illuminating unit irradiating the measured object with light from a different direction; an imaging unit receiving reflected light of the light with which the measured object is irradiated by the first light illuminating unit and the second light illuminating unit; a first and a second reference plate having a mirror surface and a diffuse surface, respectively; and an image inspecting unit inspecting a gloss distribution of the image based on the amount of light received by the imaging unit and a correcting coefficient.

Abstract: A fixing device includes a metal thermal conductor provided inside a loop formed by a fixing rotary body to heat the fixing rotary body; a heater provided inside the metal thermal conductor to heat the metal thermal conductor; a pad support provided inside the metal thermal conductor; and a reflector provided between the heater and the pad support to reflect heat emitted by the heater thereto toward an inner circumferential surface of the metal thermal conductor. The reflector includes a center reflection portion provided at a center of the reflector in a longitudinal direction thereof and a plurality of end reflection portions provided at respective lateral ends of the reflector. A plurality of reflector moving assemblies is connected to the plurality of end reflection portions of the reflector, respectively, to tilt the plurality of end reflection portions toward the center reflection portion.

Abstract: An information processor includes a storage unit storing a first coefficient in correspondence with a characteristic of a sheet of paper, a first acquisition unit acquiring a first signal based on the water content of a first sheet of paper not having an image formed thereon, a second acquisition unit acquiring a second signal based on the water content of the first sheet of paper having an image formed thereon and being heated for fixing, a determination unit determining the characteristic of the first sheet of paper, a first calculation unit calculating a variation in water content of the first sheet of paper using the difference between the first signal and the second signal and the first coefficient stored in correspondence with the determined characteristic, and a second calculation unit calculating an expansion and contraction ratio of the first sheet of paper using the variation in water content.

Abstract: An image forming apparatus has a sheet size detecting unit with first and second arms each moved by contact with a moving sheet, the arms disposed at differing locations in a direction orthogonal to sheet movement. An actuator which acts on the sensor is not moved when only one arm is moved by sheet contact, but is moved when both arms are moved by sheet contact so that the sensor output level when only one arm is moved is the same as when neither arm is moved, and the output level of the sensor when both of arms have moved differs from when neither arm moves. The first and second arms have first and second regulating portions, respectively, for regulating actuator movement, and the actuator is moved only when both regulating portions are moved from contact of both arms with the moving sheet.

Abstract: An effective image area can be properly corrected in accordance with the quantity of light from an irradiation unit by selecting, as the effective image area, pixels having light quantities more than or equal to a threshold value that allows accurate acquisition of a surface image of a recording medium, on the basis of a light quantity distribution of the light from the irradiation unit. This reduces the influence of mounting accuracy of the irradiation unit, and allows the recording medium to be identified accurately.

Abstract: A fixing device includes a separator presser that presses against a plurality of separators to separate the plurality of separators from a fixing rotary body that contacts an opposed rotary body to form a fixing nip therebetween through which a recording medium bearing a toner image passes. A single driver is connected to the separator presser to separate the separator presser from the plurality of separators. An entering recording medium detector is disposed upstream from the fixing nip in a conveyance direction of the recording medium to detect the recording medium. A controller is connected to the driver to control the driver based on a detection signal sent from the entering recording medium detector to change a contact time period for which the plurality of separators contacts the fixing rotary body.

Abstract: An image forming apparatus includes a sheet-type determining unit that determines a sheet type of a recording sheet; a sheet-characteristic measuring unit that measures a sheet characteristic of the recording sheet; an image processing unit that performs an image processing on image data of an image for adjusting a consumption amount of color material that is used for forming the image on the recording sheet based on the sheet type and the sheet characteristic; and an image forming unit that forms the image of the image data processed by the image processing unit on the recording sheet.

Abstract: A transfer and fixing device as means for heating a recording medium prior to transfer and fixing, without risk of fire, superior in energy efficiency, and able to stably heat irrespective of the thickness of the recording medium; and an imaging forming apparatus comprising such a transfer and fixing device comprising: a transfer and fixing member by which an image is transferred; a pressurizing member that forms a nip by pressure contact with the transfer and fixing member and pressurizes and fixes the image on the recording medium that passes through the aforementioned nip; a radiant heat source that is arranged on the upstream side of the nip in the direction of transport of the recording medium; and a thermoconductive member that is heated by the radiant heat source and heats the recording medium when in contact, wherein a radiant heat region is provided, between the nip and the thermoconductive member, where the recording medium is heated by radiant heat from the radiant heat source.

Abstract: An image forming apparatus that reduces a time period during which no image is formed due to a margin in leading end portion, by calculating the margin in leading end portion from position information of an image and moving forward output timing of a /TOP signal according to the margin in leading end portion.

Abstract: An image forming system including an image forming device forming on a recording sheet a first chromatic toner image, and a second chromatic toner image having an outermost layer of transparent toner, wherein the transparent toner has lower glass transition temperature than the chromatic toners; a fixing device having a fixing member contacting the recording sheet to heat the toner images to temperature not lower than the glass transition temperature of the chromatic toners so that the toner images are fixed; and a glossing device having a glossing member contacting the recording sheet to heat the toner images to temperature not lower than the glass transition temperature of the transparent toner and lower than the glass transition temperatures of the chromatic toners so that only the transparent toner achieves a rubber state and to cool the heated first and second toner images so that the transparent toner is solidified.

Abstract: According to embodiments, an image forming apparatus has a sensor that scans a sheet to detect an identifier on the sheet, which indicates the presence, and orientation, of a form on the sheet, a memory that holds a reference pattern of the identifier, a control section that is configured to compare the identifier detected by the sensor and the reference pattern and determine the orientation of the form, and an image forming unit that form an image on the sheet. The image forming unit is configured to form the image so that the orientation of the image conforms to the orientation of the form.

Abstract: A method and system for printing image documents using a variety of toners where some toners using a multi-development station having two or more development stations. These toners are co-printed prior to fixing, on the receiver by the multi-development station.

Abstract: An image forming apparatus includes an image forming portion for forming a toner image of color toner and transparent toner on a recording material; a heating device for heating the toner image formed on the recording material; an execution portion for executing a mode in which the transparent toner is partly placed in an image formable region of the recording material; and a control portion for controlling, on the basis of an amount of the color toner to be placed in an adjacent region adjacent to a region in which the transparent toner is to be placed, the amount of the transparent toner so that the amount of the transparent toner to be partly placed on the recording material when glossiness in the adjacent region is high is larger than that when the glossiness in the adjacent region is low.

Abstract: An rotation angle of a crank arm is calculated on the basis of a period of time in which a recording material is detected or a period of time in which the recording material is not detected and an end position of the recording material is calculated from the calculated rotation angle, so that detection of the end position of the recording material can be started regardless of a stop position of a sensor and the end position of the recording material can be accurately detected without using a dedicated drive source or member to reciprocate the sensor.

Abstract: Dot patterns formed by two different half-tone processes of the plurality of tone processes for each color of CMYK and formed with/without the presence and absence of transparent toner overlap are created and test patches obtained by collecting the dot patterns are printed. The printed test patches are read to generate image data, and tone correction arithmetic is performed on the basis of the image data. Concentration in the case of the presence of transparent toner in a different half-tone process is predicted based on the dot patterns with the transparent toner overlap in the test patches and concentration in the case of the absence of transparent toner in a different half-tone process is predicted based on the dot patterns without the transparent toner overlap in the test patches. The tone correction arithmetic is performed based on the predicted values.

Abstract: An image forming apparatus includes control device for selectively executing a first mode in which the non-transparent toner image is formed, then the transparent toner image is formed on the sheet not yet heated, then the sheet is subjected to the heating or a second mode in which the non-transparent toner image is formed, then the transparent toner image is formed on the sheet subjected to the heating, then the sheet is subjected to the heating; and storing device for storing selection information compared with information of amount of the non-transparent toner image, wherein the selection information indicates which mode provides larger difference in glossiness of the image fixed by the fixing device between when the transparent toner image of a predetermined amount is overlaid on the non-transparent toner image of a amount to be formed on the sheet and when the transparent toner image is not overlaid.

Abstract: In the case of a standard sized sheet, a first controller sets a linear velocity D of an image bearing member at a first velocity and sets a linear velocity S of a toner bearing member so that S/D, which is a ratio of the linear velocity S to the linear velocity D, has a first value and a second controller sets the thickness of the toner layer carried on the toner bearing member at a first layer thickness. In the case of a long sheet, the first controller sets the linear velocity D at a second velocity slower than the first velocity and sets the linear velocity S so that the S/D has a second value larger than the first value and the second controller sets the thickness of the toner layer at a second layer thickness smaller than the first layer thickness.

Abstract: An effective image area can be properly corrected in accordance with the quantity of light from an irradiation unit by selecting, as the effective image area, pixels having light quantities more than or equal to a threshold value that allows accurate acquisition of a surface image of a recording medium, on the basis of a light quantity distribution of the light from the irradiation unit. This reduces the influence of mounting accuracy of the irradiation unit, and allows the recording medium to be identified accurately.

Abstract: An image forming apparatus includes a plurality of toner-image forming units that receive image data and form electrostatic latent images on image bearing members in accordance with the image data, and form toner images of respective colors by developing the electrostatic latent images, an intermediate transfer member onto which the toner images are transferred, a transfer unit that transfers the toner images of the respective colors onto the intermediate transfer member, a controller that performs transfer control for changing a transfer pressure applied when the transfer unit transfers the toner images onto the intermediate transfer member, and a misregistration detector that detects a difference of a transfer position of each of the toner images of the respective colors on the intermediate transfer member when the transfer control is performed by the controller.

Abstract: An optical sensor includes an irradiation system emitting linearly polarized light of a first polarization direction toward a surface of an object from an incident direction inclined with respect to a normal to the surface; a first light detection system including a first light detector placed on a light path of light emitted from the irradiation system and specularly reflected by the object; and a second light detection system including a separation optical element placed on a light path of light diffusely reflected by the object, on a plane of incidence of the object, and extracting a linearly polarized light component of the first polarization direction included in the light diffusely reflected by the object, a second light detector receiving the linearly polarized light component of the first polarization direction extracted by the separation optical element and a third light detector receiving the light diffusely reflected by the object.