Abstract: An image forming apparatus includes a member having a certain function, a learned model, and an estimation unit. The learned model is obtained by learning of a self-organizing map model having an input layer and an output layer. The estimation unit gives multidimensional input data related to the member to the input layer, and estimates a state of the member on the basis of one of a plurality of nodes of the output layer.

Abstract: An image forming apparatus includes a black image carrier that holds toner images of black, a yellow image carrier that holds toner images of yellow, a magenta image carrier that holds toner images of magenta, a cyan image carrier that holds toner images of cyan, at least one spot-color image carrier, and multiple collecting units. The at least one spot-color image carrier holds toner images of a spot color other than black, yellow, magenta, and cyan. Each of the collecting units collects waste toner. The collecting units include a first collecting unit that collects waste toner removed from the black image carrier, and waste toner removed from the spot-color image carrier.

Abstract: An image forming apparatus includes a detection unit that optically detects a density of a reference toner image for density measurement formed on an image carrier. Either a first detection method for detecting the density of the reference toner image by receiving specularly reflected light reflected by the image carrier and the reference toner image for density measurement formed on the image carrier or a second detection method for detecting the density of the reference toner image by receiving diffusely reflected light from the image carrier and the reference toner image, is selected in accordance with color information of a toner, the color information being stored beforehand in a storage unit, and the density of the reference toner image is optically detected.

Abstract: A detecting device, which is included in an image forming apparatus, includes a detector configured to optically detect at least one of a position of a sheet, a position of an image formed on the sheet, and the image formed on the sheet, and a rotary body disposed at a position opposed to the detector and having a shaft, the rotary body being rotatable about the shaft in a sheet conveying direction of the sheet. The sheet is conveyed to space between the detector and the rotary body. The rotary body has a reference plane on an outer circumferential surface, a line formed on the reference plane and extending in a width direction perpendicular to the sheet conveying direction. The detector detects the line on the reference plane while the rotary body is rotating when the sheet does not intervene between the detector and the rotary body.

Abstract: There is provided a configuration in which a foreign object is less likely to drop onto a detection surface of a sensor when a protection member moves. The protection member is disposed above the sensor movably between a first position and a second position, and has a detection hole formed to expose a detection surface of the sensor at the first position. The protection member covers the detection surface in a part, in which the detection hole is not formed, at the second position. A protruding wall portion is provided at least at an upstream edge of the detection hole, with respect to a direction in which the protection member moves from the second position to the first position, so as to protrude upward from a top surface of the protection member.

Abstract: An image forming apparatus capable of controlling density of an output image with high accuracy regardless of variation of internal temperature. A controller controls an image forming unit to form a measurement image, controls a light receiving unit to receive reflected light from the measurement image, controls a conversion unit to convert an output value of the light receiving unit, and controls an image formation condition based on a value that is obtained by converting the output value. An adjustment unit controls the light receiving unit to receive reflected light from an image bearing member, and adjusts the emission light amount of an emission unit based on the reflected light from the image bearing member. A selection unit selects a conversion condition from among conversion conditions based on a reference temperature that is detected when the adjustment unit adjusts the emission light amount and a current temperature.

Abstract: The image-forming apparatus includes multiple developing units that form images using multiple color developers, an image carrier that, in color displacement detection, carries the developers transferred thereon at mutually different image-carrying positions, an optical sensor that projects a light to the image carrier and receives a reflected light from the image carrier, and an acquirer that acquires, in response to output from the optical sensor, passage times at which the developers on the image carrier respectively pass a detection position. The optical sensor receives a diffusively reflected light from a non-transferred area of the image carrier on which the developers are not transferred. The acquirer acquires the passage times of all the developers, in response to changes in the output from the optical sensor at an output level higher than that corresponding to a diffusively reflected light from the developers on the image carrier.

Abstract: An image forming apparatus includes an image bearing member, an optical sensor including a light emitting portion, a light receiving portion and a cover member, a cleaning member, and a supporting member movable between a proximity position where the optical sensor opposes the image bearing member with a predetermined distance and a spaced position where the optical sensor is spaced from the image bearing member by a distance more than the predetermined distance to form a cleaning space between the optical sensor and the image bearing member. When the supporting member is in the proximity position, the cleaning member is in a retracted position retracted from an opposing space between the optical sensor and the image bearing member. When the supporting member is in the spaced position, the cleaning member is in a cleaning position for cleaning the cover member with the cleaning member.

Abstract: A toner density sensor includes: a light emitting element configured to radiate light; a light receiving element configured to receive the light emitted from the light emitting element and reflected from a detection object; a substrate whereon the light emitting element and the light receiving element are surface mounted; a case covering the light emitting element and the light receiving element; an optical path configured parallel to the substrate for light generated from the light emitting element; a groove provided in the substrate from the end part of the substrate in the direction light travels from the light emitting element to between the light emitting element and the light receiving element, the groove recessed from the mounting surface in the thickness direction of the substrate; and an insert provided to the case and configured for insertion into the groove.

Abstract: A non-transitory computer-readable storage medium may store computer-readable instructions for a communication apparatus, wherein the computer-readable instructions, when executed by a processor of the communication apparatus, cause the communication apparatus to perform: obtaining first and second radio field intensities from the first external apparatus; calculating a first value indicating a ratio of the first and the second radio field intensities; obtaining third and fourth radio field intensities from the second external apparatus after receiving the third predetermined signal; calculating a second value indicating a ratio of the third and fourth radio field intensities; specifying a relationship between first and second distances by using the first and second values, the first distance being a distance between the communication apparatus and the first external apparatus, and the second distance being a distance between the communication apparatus and the second external apparatus; and outputting target

Abstract: An image forming apparatus includes an image bearer, a detector, an image bearer support, and a fulcrum. The image bearer bears an image on a surface thereof. The detector detects a condition of the image bearer. The image bearer support supports the image bearer and includes a stopper to regulate movement of the detector. The fulcrum pivotally supports the image bearer and the detector.

Abstract: An image forming apparatus 100 includes an intermediate transfer belt 21, a reading section 25, and an intermediate transfer unit 2 having a supplementary roller 26. The intermediate transfer belt 21 is passed over a drive roller 22 and an idle roller 23, and moves along a predetermined circulating path. The reading section 25 reads a concentration of a toner image from a surface of the intermediate transfer belt 21. The supplementary roller 26 is in contact with a rear face of the intermediate transfer belt 21 in such a manner that a gap between a reading face of the reading section 25 and the surface of the intermediate transfer belt 21 is kept constant. The supplementary roller 26 is disposed on a downstream side of the reading section 25 in a horizontal direction by a predetermined distance S.

Abstract: An image forming apparatus includes a plurality of image forming stations, each including a developing device, a toner container containing a colored or special toner, and a replaceable supply-toner conduit extending from the toner container to the developing device; and a toner type identifier to identify a type of toner used in the supply-toner conduit of each of the plurality of image forming stations.

Abstract: Representative configurations of a cleaning apparatus, a process cartridge and an image forming apparatus according to the present invention includes: a cleaning blade which abuts on a photosensitive drum which bears a toner image, and which removes toner which remains on the photosensitive drum; compression springs which are compressed to pressurize the cleaning blade against the photosensitive drum; and spring attaching portions which regulate phases of compression springs such that positions of the compression springs in a circumferential direction are at predetermined phase positions when the compression springs are attached.

Abstract: A moving device assembly includes a moving device and a shield. The moving device is movable between a first position and a second position, to move a detector including a detection surface relative to an opposing member disposed opposite the detector. The shield shields the detection surface of the detector. As the moving device is at the first position, the detector is at a proximal position at which the detector is near the opposing member, and as the moving device is at the second position, the detector is at a shield position at which the detector is separated from the opposing member and the detection surface of the detector is shielded by the shield.

Abstract: An image forming apparatus includes an image forming unit, which forms a test pattern for density control on the image carrier; and first and second light receiving elements, which receive reflected light irradiated by a light emitting element. A spot diameter of a reflected light received by the first light receiving element is smaller than a spot diameter of a reflected light received by the second light receiving element, and a number of sampling of the test pattern in line with a movement direction of a surface of the image carrier by the first light receiving element is greater than that of the test pattern in line with the moving direction by the second light receiving element.

Abstract: An image forming apparatus includes a photoconductor, an optical scanner, a development device, a movable density sensor, a density sensor driver, and a processor. The optical scanner includes a light source to emit light, and irradiates a surface of the photoconductor in a main scanning direction with the light to form a latent image on the surface of the photoconductor. The development device develops the latent image into a toner image. The density sensor detects unevenness in density of the toner image in the main scanning direction. The density sensor driver moves the density sensor in the main scanning direction. The processor corrects a driving signal for the light source according to image data to reduce the unevenness in density in the main scanning direction, according to positional data of the density sensor in the main scanning direction and an output value of the density sensor.

Abstract: An image forming apparatus performs density correction. An image forming section forms a density detection image on a belt. A light source irradiates the image with light. A light receiving section receives light reflected from the image and outputs a plurality of intensity signals of the received light. An intensity obtaining section drives the belt and the light source, thereby illuminating the image a first number of times at intervals of a first distance as the belt runs, and the light receiving section receives the light reflected from the image, the first number of times being determined by at least the first distance and a second distance in which the first distance lies. A selecting section selects a second number of levels of light intensity from the plurality of intensity signals. A density correcting section performs print density correction using the second number of levels of light intensity.

Abstract: An optical sensor configured to irradiate an object area with light and receive reflected light, amplify a voltage in accordance with the reflected light by an amplifier circuit and a resulting voltage, the optical sensor comprising a recording medium recorded with information indicating a noise component calculated, based on characteristics of an input voltage and an output voltage of the amplifier circuit.

Abstract: When a recording agent amount limiting process is carried out, a color reproduction range is narrowed, and therefore gradation properties of dark areas are deteriorated and information originally held by an image is sometimes undesirably lost. By obtaining (401) a colorant amount for each target pixel of input color image data, calculating (402) a colorant amount of a peripheral area of the target pixel, and correcting (400) a density range of the input color image data based on the colorant amount of the target pixel and the colorant amount of the peripheral area of the target pixel, amounts of recording agent are limited and reductions in image quality are prevented.

Abstract: An optical sensor is disclosed. The optical sensor includes an irradiating system which irradiates a linearly polarized light; a first photodetecting system including a first photodetector which is arranged on an optical path of a light which is specularly reflected from a subject; a second photodetecting system including an optical element which is arranged on an optical path of a light which is diffuse reflected from the subject within an incident face in the subject and which separates a linearly polarized component in a second polarizing direction which is orthogonal to a first polarizing direction and a second photodetector which receives a light separated by the optical element, wherein an angle of taking in the light in the first photodetector and an angle of taking in the light in the second photodetector are mutually different.

Abstract: Techniques related to color analysis are disclosed herein. In an example, substrate locations on a printed pattern are selected based on a set of measurements related to substrate-height. Further, color of the printed pattern is determined at the selected locations.

Abstract: A positioning device to position a first member relative to a second member includes two convex parts disposed on a side of the first member and apart from each other; and positioning portions disposed on a side of the second member so as to contact the convex parts, each of which is disposed apart from each other and opposed to the two convex parts. The positioning portions includes two planar portions disposed substantially perpendicularly relative to a direction to allow the first member to approach the second member; and a slanted portion disposed in the vicinity of one of the two planar portions and angled with respect to a direction to allow the first member to approach the second member. The second member is an endless belt, on which an image pattern for detection is formed, and the first member is a sensor to detect the image pattern formed on the endless belt.

Abstract: A reflective optical sensor includes at least three light-emitting elements; a lighting optical system that guides light emitted from the light-emitting elements to a toner pattern; and at least three light-receiving elements that receive the beams of light reflected by the toner pattern. The lighting optical system has a lateral magnification m that satisfies m?P/S, where S is the size of the light-emitting elements and P is the arrangement pitch of the light-emitting elements.

Abstract: A toner density is calculated from outputs of light-receiving elements based on a difference between a reflection property of a supporting member and a reflection property of a toner pattern. Light-emitting elements aligned in one direction that is inclined to a sub-direction emit a detection light in such a manner that a distance between adjacent spots falling on the supporting member in a second direction is equal to or smaller than a width of the toner pattern in the second direction. The light-receiving elements receive a reflected light reflected from the supporting member and/or the toner pattern. The light-receiving elements are aligned, opposed to the supporting member, in a one direction corresponding to the light-emitting elements.

Abstract: A reflection sensor includes the following elements. A light emitting unit emits light to an area of an image forming apparatus where first detection images of plural colors used for detecting amounts of their misregistration are formed. A first light restricting member/configuration restricts light emitted from the light emitting unit. A light receiver is disposed in an optical path of regular reflection light, and receives reflected light and outputs a signal representing an amount of received light. A second light restricting member/configuration is disposed in the optical path of the regular reflection light and restricts light to be received by the light receiver. The value obtained by dividing a diameter of the first light restricting member/configuration by that of the second light restricting member/configuration ranges from substantially 0.5 to 1.9, and the diameters of the first and second light restricting members/configurations are each 1.5 mm or smaller.

Abstract: An information processing apparatus includes: a total amount control unit that applies a total amount controlling process to perform correction such that a sum of density values of all pixels composing the color plane data and clear plane data becomes not larger than a certain value; a clear toner plane generating unit that generates clear toner plane data based on gloss control plane data, the clear plane data and the color plane data; a difference calculating unit that calculates a difference between the density value of a pixel of the clear toner plane data and the density value of the pixel of the clear toner plane data to which the total amount controlling process is applied, for each pixel; and a display unit that displays an inconsistent region composed of a pixel in which the difference is not smaller than a predetermined threshold.

Abstract: The circuit substrate includes at least two lands formed on a substrate, wherein one electrode is to be mounted on the at least two lands, an electronic part having electrodes, one of the electrodes is soldered on the at least two lands with solders whose amounts are adjusted by a metal mask having at least two opening parts, positions of the at least two opening parts corresponding to the at least two lands when the solders are applied and melted, areas of the at least two opening parts being different with each other, wherein a height of one of the solders is different from a height of the other of the solders according to the difference of the areas of the at least two opening parts of the metal mask, whereby the electronic part is mounted on the circuit substrate in an inclined state.

Abstract: A toner density sensor comprising: a light emitting element that emits light; a light receiving element that receives reflected light emitted from the light emitting part and reflected at a detection target; a light path for passage of emitted and reflected light formed along the front surface of a printed substrate on which the light emitting element and the light receiving element are surface-mounted; and a diaphragm unit that is formed at and partially narrows this light path, wherein the diaphragm unit is divided into two portions, a diaphragm unit upper-portion and a diaphragm unit lower-portion, and these are disposed in an upper case covering the front surface of the printed substrate and in a lower case covering the rear surface of the printed substrate. In the printed substrate, a through hole is formed for protrusion of the diaphragm unit lower portion from the rear surface to the front surface.

Abstract: In an embodiment, a diffuse reflection output conversion method is executed in an apparatus detecting a plurality of gradation patterns. The apparatus includes a light emitter and light receiver, and detects specular reflection and diffuse reflection simultaneously. A region before specular reflection saturation is a region where the specular reflection component decreases and saturates at minimum level. A diffuse reflection detector is calibrated by: obtaining a diffuse reflection output resulting from an amount of attached powder at a border between the region before specular reflection saturation and the region after specular reflection saturation; calculating a ratio between the diffuse reflection output and a reference diffuse reflection output calculated in advance as a calibration coefficient; and multiplying a diffuse reflection output obtained from the gradation patterns by the calibration coefficient calculated at the calculating.

Abstract: An image forming apparatus includes an image carrier, an image forming means for forming a patch image on the image carrier, a light emitting means, a plurality of light receiving means adjacently arranged so as to receive light reflected from the patch image when light is irradiated by the light emitting means onto the patch image which moves with movement of the image carrier and each including one or more light receiving elements, and an output means for outputting an output signal that depends on a difference between a received light quantity of a first light receiving means and a received light quantity of a second light receiving means that are respectively odd-numbered and even-numbered in the arrangement order of the light receiving means.

Abstract: An image forming apparatus is provided. The image forming apparatus includes a sensing unit configured to check a transfer belt, which serves to transfer a visible image to a printing medium, the image forming apparatus capable of reducing contamination of sensors since a lighting window of a sensor provided in the sensing unit is open and closed by a shutter and a shutter driving device.

Abstract: An image forming apparatus including a main body provided with an opening, a cover to open and close the opening, a plurality of development units developing electrostatic latent images into visible images through developers, a transfer device including an intermediate transfer belt receiving the developers from the plurality of development units and transferring the developers to printing media, and a sensor unit provided with light windows located at first positions opposite the intermediate transfer belt when the opening is closed by the cover, and located at second positions exposed to the opening when the opening is opened by the cover. Thereby, a user may clean the light windows through the opening.

Abstract: A photosensor includes a light emitting element to emit light to a target object, a light receiving element to receive the light emitted from the light emitting element and reflected by the target object, and a circuit board on which the light emitting element and the light receiving element are mounted, including at least one protrusion thereon. The light emitting element and the light receiving element each have a terminal. The at least one protrusion is configured to support one of the light emitting element and the light receiving element in a contact manner in a state that the terminal is electrically connected to the circuit board.

Abstract: An optical sensor attached to an apparatus includes a substrate and a light emitting element mounted on a first surface of the substrate. The light emitting element emits a light to a detection object in parallel to the substrate. A light receiving element is mounted on the first surface of the substrate. The light receiving element receives a regular reflection light reflected by the detection object. The said first surface serves as a positioning reference for positioning the optical sensor on an optical sensor mounting member provided in the apparatus.

Abstract: An image forming apparatus includes an image forming unit configured to form a patch image on an image carrier; a light receiving unit configured to receive light reflected by the patch image irradiated with light by a light emitting unit, and including one or more light receiving elements; and a setting unit configured to set the number of the light receiving elements in the light receiving unit. The setting unit is further configured to set the number of light receiving elements for when receiving reflected light from a first patch image formed by the image forming unit and the number of light receiving elements for when receiving reflected light from a second patch image formed by the image forming unit that differs from the first patch image to different numbers.

Abstract: An image forming apparatus 100 includes an intermediate transfer belt 21, a reading section 25, and an intermediate transfer unit 2 having a supplementary roller 26. The intermediate transfer belt 21 is passed over a drive roller 22 and an idle roller 23, and moves along a predetermined circulating path. The reading section 25 reads a concentration of a toner image from a surface of the intermediate transfer belt 21. The supplementary roller 26 is in contact with a rear face of the intermediate transfer belt 21 in such a manner that a gap between a reading face of the reading section 25 and the surface of the intermediate transfer belt 21 is kept constant. The supplementary roller 26 is disposed on a downstream side of the reading section 25 in a horizontal direction by a predetermined distance S.

Abstract: Toner sensor modules are provided. In one aspect, a toner sensor module has a first light source emitting a first light, a first light sensor that generates a sensed light signal that is indicative of a sensed light, and a frame. The frame positions the light source to illuminate a target area from a first side a plane that is normal to the target area so that illuminated portions of any toner particles at the target area direct a reflected a portion of the first light into the first side and positioning the first light sensor on the first side of the plane to which toner particles at the target area direct the reflected portion of the first light.

Abstract: In the image processing device, the color conversion part converts the input value to an output value by using a color profile. The correction part corrects the output value to a corrected value by using a correction table. The update part updates the correction table based on a density patch. The first and second amount is an estimated amount of the color material to be consumed when corrected image data corrected by either using the updated correction table or using an initial correction table, respectively, is printed. When the amount determining part determines that the first amount is greater than the second amount, the modifying part modifies the color profile such that the output value in the modified color profile specifies a less amount of color material than an amount of color material specified by the output value in the unmodified color profile.

Abstract: An image forming apparatus includes an image bearing member, a toner image forming unit, a sensor, and a control unit. The toner image forming unit is configured to form a toner image on the image bearing member. The sensor includes a light-emitting unit for emitting light, a light-receiving unit for receiving reflected light, an electrical circuit board in which the light-emitting unit is attached, and a frame supporting the electrical circuit board with the electrical circuit board bonded with three supporting portions. The sensor is configured to detect the toner image formed on the image bearing member. The control unit is configured to control a toner image forming condition of the toner image forming unit according to an output of the sensor.

Abstract: An image forming apparatus, comprising: an image formation unit configured to form an image on a sheet; a sensor unit having a light-emitting device and a light-receiving device; a frame to which the sensor unit is attached; at least one projection provided on one of the sensor unit and the frame, the at least one projection being formed to have a contacting part which projects to contact an other of the sensor unit and the frame; and at least one engagement part provided on one of the sensor unit and the frame, the at least one engagement part being formed to engage with at least one catching part provided on an other of the sensor unit and the frame and to press the at least one projection in a direction of increasing a contact surface pressure of the contacting part by causing elastic deformation.

Abstract: A detection device detecting a state of a toner image, an image forming apparatus including a detection device and method of detection are provided. The detection device includes a detector having a light window where light passes through and detecting a state of a toner image formed on an image bearing member via the light window, and a cleaner removing a pollutant attached to a surface of the light window. The cleaner includes an adsorption unit formed of a conductive material and reciprocating while being in contact with the surface of the light window and a voltage applying unit applying a voltage for adsorbing the pollutant to the adsorption unit.

Abstract: A detection device includes an irradiation unit that irradiates a medium with first irradiation light, a first optical system that has a first incident surface and changes the first irradiation light into second irradiation light, a second optical system that has a second incident surface and changes the first irradiation light into third irradiation light, and a light receiving unit that is provided in a traveling direction of reflection light of the second irradiation light and the third irradiation light, which are specularly reflected by the medium, and receives the reflection light of the second irradiation light and the third irradiation light, which are specularly reflected by the medium, so as to detect a positional deviation amount of an image formed on the medium and detect a density deviation amount of the image formed on the medium.

Abstract: An optical sensor, which can be included in an image forming apparatus, includes a detecting portion disposed facing a detection target and configured to detect the detection target by emitting light to the detection target, a dust-proofing member having a surface disposed facing the detection target and configured to cover the detecting portion, a vibration member configured to vibrate the surface of the dust-proofing member, and a collecting member configured to collect dust in the vicinity of the dust-proofing member. On the surface of the dust-proofing member facing the detection target, at least a portion that intersects a pathway of light emitted from the detection portion is formed as a thru-beam part by a material through which the light transmits.

Abstract: A toner density is calculated from outputs of light-receiving elements based on a difference between a reflection property of a supporting member and a reflection property of a toner pattern. Light-emitting elements aligned in one direction that is inclined to a sub-direction emit a detection light in such a manner that a distance between adjacent spots falling on the supporting member in a second direction is equal to or smaller than a width of the toner pattern in the second direction. The light-receiving elements receive a reflected light reflected from the supporting member and/or the toner pattern. The light-receiving elements are aligned, opposed to the supporting member, in a one direction corresponding to the light-emitting elements.

Abstract: Provided is a detecting apparatus including an illumination optical system for emitting an image bearing member with a light beam emitted from a light source unit, an imaging optical system including an imaging optical element for imaging an image on the surface of the image bearing member, a light receiving unit for detecting the image on the image bearing member which has been imaged by the imaging optical system, and a calculation unit for detecting image information on the image on the image bearing member from a detection signal received from the light receiving unit. In the detecting apparatus, at least one optical plane of the imaging optical element is configured to refract an imaging system principal ray after passing therethrough in a direction of farther becoming apart from the light source unit than the imaging system principal ray before passing through the optical plane.

Abstract: A positioning device to position a first member relative to a second member includes two convex parts disposed on a side of the first member and apart from each other; and positioning portions disposed on a side of the second member so as to contact the convex parts, each of which is disposed apart from each other and opposed to the two convex parts. The positioning portions includes two planar portions disposed substantially perpendicularly relative to a direction to allow the first member to approach the second member; and a slanted portion disposed in the vicinity of one of the two planar portions and angled with respect to a direction to allow the first member to approach the second member. The second member is an endless belt, on which an image pattern for detection is formed, and the first member is a sensor to detect the image pattern formed on the endless belt.

Abstract: A moving device assembly includes a moving device and a shield. The moving device is movable between a first position and a second position, to move a detector including a detection surface relative to an opposing member disposed opposite the detector. The shield shields the detection surface of the detector. As the moving device is at the first position, the detector is at a proximal position at which the detector is near the opposing member, and as the moving device is at the second position, the detector is at a shield position at which the detector is separated from the opposing member and the detection surface of the detector is shielded by the shield.

Abstract: An image forming apparatus includes a sensor member having first and second ends opposite to each other in a longitudinal direction of the sensor member and supported by support structures consisting of the first and second ends, and first and second support portions supporting the first and second ends; a first support structure including a first protruding portion fitted on a first recess portion supporting the first protruding portion; and a second support structure including a second protruding portion fitted on a second recess portion supporting the second protruding portion. The second protruding portion has first and second cylinder portions extending in a longitudinal direction of the second protruding portion. The second recess portion has an insertion portion allowing the second protruding portion to be inserted, a pass portion allowing the first cylinder portion to pass therethrough, and a positioning portion fitted on the second cylinder portion.

Abstract: An image forming apparatus capable of ensuring a sufficient difference between amounts of light reflected from a base such as a transfer material and from a toner pattern in the detection of the toner pattern for registration correction control by a reflective optical sensor. The image forming apparatus includes a pattern generator for generating a toner pattern, a pattern detection sensor for detecting the toner pattern formed on the intermediate transfer belt, a pattern density decider for determining the density of the toner pattern that makes the amount of light received by the sensor in detection of the toner pattern equal to or less than a predetermined value.