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: A colorimetric chart, for measuring a color reproduction characteristic of an image forming apparatus, includes: a patch column that is arranged in a sub-scanning direction representing a conveying direction in which the image forming apparatus conveys the colorimetric chart and that is used in detecting periodic color fluctuation attributed to the image forming apparatus, wherein the patch column includes patches that are arranged in different phases on the same patch column.

Abstract: An image forming apparatus which reduces downtime by starting image density detection without waiting for identification of the same position on a rotary member. A detection unit detects a surface condition of a rotary member on which a toner image on a photosensitive drum is transferred. An identifying unit matches first data detected by the detection unit on a reference point on the surface of the rotary member and second data detected by the detection unit after obtainment of the first data to identify the reference point. A control unit controls image density based on a detection result obtained by the detection unit on a base of the rotary member corresponding to a range where a measurement image is formed and an obtained detection result on the measurement image by referring to the reference point identified as a reference.

Abstract: An image forming apparatus that can reduce the time period for rotation of an intermediate transfer unit required before toner patches are formed, and measurement of toner patch densities while continuing the rotation. A toner image formed on a photosensitive drum is transferred to a surface of the intermediate transfer unit. A toner image for detection is formed on the intermediate transfer unit, and image forming conditions are corrected based on the amount of toner obtained by reading the toner image for detection. Two density sensors read the surface of the intermediate transfer unit. Outputs from the two density sensors are stored as a first profile and a second profile, respectively. A toner density of the toner image for detection is calculated based on the first and second profiles, and image forming conditions are corrected based on the toner density.

Abstract: An image forming apparatus capable of performing accurate gradation correction in a range of density where measurement by a toner density detection unit is- impossible. A printer unit forms a gradation pattern on an image bearing member. A density detection sensor detects density of the gradation pattern. A first correction value for correcting gradation of the image data is calculated based on density of the gradation pattern, detected by the density detection sensor, and a second correction value for correcting gradation of the image data is calculated based on the estimated condition of toner with which a toner image is formed on the image bearing member. An output gamma correction unit corrects density in a low density range of the toner image based on the first correction value, and corrects density in a high density range of the toner image based on the second correction value.

Abstract: Certain embodiments provide an image forming apparatus including a photoconductor, a latent image forming portion, an image processing portion, a developer, a transferred body, a sensor that detects an image density of a toner image by the amount of toner attached to a surface and has a sensor characteristic in which a sensor output substantially monotonously decreases according to an increase in the amount of toner, a nonlinear amplifier that has a nonlinear amplification characteristic having one or more inflection points, and enlarges and corrects a value read by the sensor in a range where the sensor output monotonously decreases with respect to the amount of toner by amplification, and an image quality control portion that controls a forming condition of an electrostatic latent image using a correction value of a variation amount of the value at a side where the amount of toner is large in the range.

Abstract: An image forming apparatus, which is capable of bringing an output density close to a target density even if a charge amount of toner particles changes, includes an image forming unit having an image carrier and a developing unit, a storage unit storing a saturation charge amount of toner particles, and a control unit. The control unit forms a patch image using the image forming unit, measures the density of the patch image to obtain a first potential that is a contrast potential corresponding to a target density, estimates the charge amount of the toner particles in the developing unit to obtain a first charge amount, obtains a second potential from the first potential, the first charge amount and the saturation charge amount, and sets the second potential as the contrast potential.

Abstract: An image forming apparatus including a control section which detects an offset of a recording sheet being conveyed, the offset being in a main scanning direction perpendicular to a conveyance direction of the recording sheet; performs an offset regulation control which adjusts a main scanning direction image area signal in accordance with the offset; and forms a patch at a non-transfer area on an image carrier, wherein the control section performs a first control based on the offset of the recording sheet for the offset regulation control while a sub scanning direction image area signal is active for image forming on the recording sheet, and performs a second control for the offset regulation control while the image area signal in the sub scanning direction is inactive.

Abstract: Methods for operating a toner printer are provided. In one method a toner image is printed according to first printing instructions. An amount of toner in a target area of the toner image is determined and second printing instructions are generated causing the toner printer to print at least one subsequent toner image based upon the determined amount of first toner.

Abstract: Methods for determining an amount of toner in a target area are provided. In one method, the target area is illuminated with a first light from a first illumination position that is on a first side of a plane that is normal to the target area so that any toner particles in the target area direct a reflected portion of the first light to the first side and a light is sensed at a surface at a sensing position on the first side of the plane to which toner particles at the target area direct the reflected portion of the first light and a sensed light signal is generated that is indicative of the sensed light.

Abstract: Toner printers are provided. In one printer a toner image is printed according to first printing instructions. An amount of toner in a target area of the toner image is determined and second printing instructions are generated causing the toner printer to print at least one subsequent toner image based upon the determined amount of first toner.

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 including an image carrying member, a detecting section, and a linear-speed deriving section. The image carrying member carries a toner image. The detecting section detects passages of a mark, provided on the image carrying member, at a plurality of predetermined detection positions. The linear-speed deriving section determines a linear speed of the image carrying member from times at which the detecting section detects the passage of the mark.

Abstract: In a reflective optical sensor in an image forming apparatus, an output from each N number of light-receiving elements (N?3), obtained when M number of light-emitting elements (M?3) included in a light-emitting unit emit detecting light, is separated into an amount of specularly reflected light and an amount of diffusely reflected light. The toner density of a pattern, which is formed on a supporting member in the image forming apparatus, is calculated based on a sum of the amounts of specularly reflected light and a sum of the amounts of diffusely reflected light.

Abstract: An image forming apparatus includes a preliminary toner image forming unit, a detecting unit, an adjusting unit, an obtaining unit, an activation grasping unit, a determining unit, and a preparation unit. The preliminary toner image forming unit causes an inactive image forming unit to form a preliminary toner image and causes the preliminary toner image to be transferred onto a transfer body. The detecting unit detects the preliminary toner image. The adjusting unit adjusts quality of a toner image. The obtaining unit obtains information regarding an image to be output. The activation grasping unit grasps an estimated activation timing. The determining unit determines whether a time period until the estimated activation timing has become equal to an image quality adjustment period. The preparation unit causes the preliminary toner image forming unit to transfer the preliminary toner image and causes the adjusting unit to adjust the quality of the toner image.

Abstract: A method, system, and computer program product for estimating exposure modulation in an image printing system is disclosed. The method includes determining a banding profile for an image printing system by a processor; determining an adjusted exposure modulation profile based on the banding profile using a least squares estimation by the processor; and printing an output based on the adjusted exposure profile.

Abstract: An image forming apparatus includes a transport member, image forming units (used as pattern forming unit), a pattern detector, and an image misalignment detector. The image forming units form correction-use patterns for each color on the transport member. The pattern detector directs a light beam onto the transport member having the correction-use patterns and detect reflected light reflecting from the transport member. The image misalignment detector detects image misalignment of the correction-use patterns. The pattern forming unit forms a reference color pattern and a first color pattern. The pattern detector uses an irradiation light having a first wavelength matched to a spectral sensitivity peak of the first color pattern to detect an intensity of reflected light reflected from the transport member. The image misalignment detector computes an image misalignment value between the reference and first color patterns based on the intensity of reflected light reflected from the transport member.

Abstract: An image forming apparatus having an image carrier; an electrostatic latent image forming device that forms an electrostatic latent image on the image carrier; a development device having a housing section that stores toner therein, a stirring device for stirring the toner inside the housing section, and a toner, carrier that develops the electrostatic latent image into a toner image by imparting the toner to the image carrier; a voltage applying device that applies a development bias voltage between the image carrier and the toner carrier; a control device that makes the electrostatic latent image forming device and the development device form a test toner image on the image carrier; and a sensing device that senses a toner adhering amount of the test toner image.

Abstract: According to an embodiment, provided is an image forming apparatus that forms an image on a moving body using toner. The image forming apparatus includes a pattern creating device that creates a first pattern for toner density detection and a second pattern for positional deviation detection on the moving body, the first pattern and second pattern being disposed to be arrayed in a main-scanning direction; a reflecting optical sensor including an emitting system that includes at least three light-emitting elements of which positions at least in the second direction are different and a light-receiving system that includes at least three light-receiving elements that receive light beams that are emitted from the emitting system and reflected from the first pattern and second pattern; and a processing device that obtains toner density information and positional deviation information simultaneously based on an output signal of the light-receiving system.

Abstract: An image forming apparatus includes a rotatable image carrier that carries a toner image having a length corresponding to at least a circumferential length of the carrier; an image density detector that detects a density of the image; a potential detector that detects, over at least the circumferential length, a surface potential of the carrier before toner adheres thereto; a first image forming device that adjusts the density with a first factor, and forms an image based on a first condition of the first factor; a second image forming device that adjusts the density with a second factor, and forms an image based on a second condition of the second factor; a first determining device that determines the first condition based on uneven density; and a second determining device that determines the second condition based on uneven density and a potential distribution of the surface potential.

Abstract: An image forming apparatus is disclosed, including a light source; a drum; an optical scanning apparatus; and an endless belt. The image forming apparatus further includes a pattern forming unit which forms, on the endless belt along a conveying direction of the endless belt, a density fluctuation detecting pattern having a period; a density sensor which detects the density fluctuating detecting pattern and outputs a density signal including information on density fluctuations in the conveying direction of the endless belt; and a period detecting sensor which detects the period included in the density fluctuations.

Abstract: An image forming apparatus includes an image carrier; a developer carrier configured to adhere toner onto the image carrier; an image density detector to detect a density of an image on the image carrier formed by the developer carrier adhering the toner on the image carrier; a rotary member to form an image pattern of which density is detected by the image density detector; and a rotational position detector to detect a rotational position of the rotary member. In the image forming apparatus, the image pattern is generated based on the rotational position detected by the rotational position detector and the rotary member that the rotational position detector detects the rotational position thereof is either the image carrier or the developer carrier.

Abstract: An image forming apparatus includes a controller configured to control a toner-image forming device to form a toner patch; and a detector configured to detect the toner patch on the image carrier. During a non-printing period, the controller causes a toner-image forming device to form toner patches, causes the detector to detect densities of the toner patches, and adjusts an image-forming condition of the toner-image forming device based on detected densities. During a printing period, the controller causes the toner-image forming device to form an output image in an image area and form fewer toner patches in a non-image area, causes the detector to detect densities of the fewer toner patches, and adjusts the image-forming condition of the toner-image forming device based on detected densities. The fewer toner patches are selected from and fewer than the plurality of toner patches formed during the non-printing period.

Abstract: In an electrophotographic image forming apparatus employing a contact development system, contact of a development roller against a photosensitive drum is started while forming an electrostatic latent image of a detection pattern for detection in each individual apparatus, and a developed toner image is detected at a predetermined position. At this time, a time from the time when contact of the development roller was started until the time when the toner image was detected is measured, and a delay time from a time when contact operation of the development roller was started until a time of actual contact is calculated by subtracting the time needed until the developed toner image reaches the detection position. The time when contact of the development roller is started is delayed by this time. The same sort of control is also performed for the separation time.

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: In an image forming apparatus, an image forming contrast potential for obtaining the maximum density is set by reading a specific pattern transferred and formed on a sheet. A photosensor detects the density of a specific pattern formed on an image carrier at the image forming contrast potential, and the detection result is stored. A correction amount for the image forming contrast potential is calculated on the basis of the relationship between the stored detected density, and the density, detected by the optical sensor, of the specific pattern formed on the image carrier at a predetermined timing. The image forming contrast potential is adjusted by the correction amount.

Abstract: An image forming apparatus for forming an image on a recording material, includes: a cartridge, detachably mountable to a main assembly of the image forming apparatus, including a memory and an image forming process member actable on an image bearing member in an image forming process; and an image density measuring portion, provided in the main assembly, for measuring a density of a developer image formed by the image forming process. The memory stores information for discriminating a state of the image forming process member on the basis of the density, measured by the image density measuring portion, of the developer image formed under an image forming condition different from that during normal image formation.

Abstract: An electrostatic transfer control method that avoids undesired retransfer effects. A printing device develops and transfers several control patches. The patches are transferred at different electrostatic set points and a control strategy is utilized involving one or more density sensors to measure the transferred toner patches whereby the obtained density information can be used to compute the optimal value of electrostatic transfer bias. Print operators can adjust the bias value based on preferences for predetermined standards.

Abstract: To restrict a period velocity change of a photoconductor that is an immediate cause of a color registration error, a gap change of a color registration error detection pattern caused by a linear velocity change of the photoconductor is acquired and a linear velocity change of the photoconductor is reduced based on a relationship between the gap change and a velocity of a motor, whereby a reduced color registration error is accomplished.

Abstract: A method for color measurement of printing materials produced in printing machines includes a first color measurement instrument in the printing machine measuring the color of printing materials, a second color measurement instrument outside the printing machine measuring the color of printing materials produced in the printing machine and a computer communicating with the instruments, storing nominal color values and regulating color in inking units of printing units with the first instrument based on deviations from the stored nominal color values, determined on the printing materials in the printing machine. Printing materials produced by the printing machine are recorded by the second instrument. The second instrument records deviations from an original based on the color measured values determined on printing materials.

Abstract: An image forming apparatus includes a toner carrier, a toner image forming unit, and a toner concentration sensor. The toner carrier includes a transparent film. The toner image forming unit forms a toner image onto the toner carrier. The toner concentration sensor senses the concentration of toner on the toner carrier. The toner concentration sensor includes first and second light emitting elements and a light receiving element. The light emitting elements each radiate light directly or indirectly to the toner carrier. The light receiving element receives reflecting light originating from the light emitting elements. The first light emitting element radiates light having a wavelength of a predetermined reflectance resulting from direct radiation to the toner carrier. The second light emitting element radiates light having a wavelength that causes a lower reflectance resulting from direct radiation to the toner carrier than a reflectance resulting from radiation to the toner.

Abstract: An image forming apparatus includes a recording medium transport belt which is suspended by a plurality of roller members. An image is secondarily transferred from a first image carrier through an intermediate transfer body to a recording medium. An image is directly transferred from a second image carrier to the recording medium. The image forming apparatus further includes a pattern image sensing unit which senses a pattern image transferred from the first image carrier and the second image carrier finally to the recording medium transport belt. Each of a distance from a secondary transfer position to a sensing position and a distance from a direct transfer position to the sensing position in a recording medium transport belt rotation direction is a natural number times a circumferential length of a roller member causing a speed change in the recording medium transport belt among the plurality of roller members.

Abstract: A method for compensation of banding in a marking platform includes: initiating a calibration stage; marking a test pattern over multiple intervals of a lowest fundamental frequency among marking modules; obtaining image data for the test pattern from a sensor; obtaining 1× signals from sensors associated with the marking modules; and processing the image data in relation to the 1× signals to form banding profiles for multiple marking modules. Alternatively, the method may include: processing image data in relation to 1× signals to form banding profiles for multiple marking modules; determining amplitudes in multiple banding profiles exceeds a threshold to identify dominant banding profiles; and processing dominant banding profiles to form dominant banding signatures.

Abstract: The image forming apparatus includes: an image forming unit forming an image on a medium by using an image forming portion; a mode setting unit setting an image forming mode of plural image forming modes, the plural image forming modes setting, at a time of forming the image, different image forming conditions for the image forming portion included in the image forming unit; an adjusting unit performing adjustment of an image forming condition in the image forming mode; and a measuring unit individually measuring, for each of the image forming modes, a progress state after the adjustment of the image forming condition is performed by the adjusting unit in the image forming mode. The adjusting unit performs the adjustment of the image forming condition when the progress state in the image forming mode exceeds a certain value in the image forming mode.

Abstract: An image forming apparatus may include an image carrier for carrying a toner image and a correcting toner image, a detection sensor for detecting density information of the correcting toner image; and a controller for causing the image forming unit to correct an image forming condition based on the density information detected by the detection unit to execute a stabilization control. The image forming unit may form a plurality of correcting toner images different in density over plural non-image areas. The controller may determine which mode is set between a processing speed priority mode and an image quality priority mode. The image forming unit may continuously form correcting toner images on the image carrier in a different manner depending on the mode. The detection sensor may detect density information of the correcting toner images. The image forming unit may finish a processing operation in the stabilization control under execution.

Abstract: A high-density area of a low-reflectance patch image is accurately detected. There is an image forming apparatus that detects the density of a patch image by radiating light from a laser oscillator 701 and receiving reflected light reflected off the patch image using a line sensor 704. The density of a black patch image 720 having a low reflectance is detected from the difference between the position at which reflected light from a yellow patch image 710 is received and the position at which reflected light from a superimposed toner image that is transferred in such a manner that the yellow patch image 730 is superimposed on the top of the black patch image 720 is received.

Abstract: A controller includes a pattern forming unit that forms patterns multiple times on a first image holding member which is driven such that a surface thereof is circulated, a first detection unit that optically detects the patterns formed on the first image holding member by the pattern forming unit, a second detection unit that optically detects the patterns transferred from the first image holding member to a recording medium which is transported in a set transport direction, and an adjustment unit that adjusts a length in the transport direction of an image transferred to the recording medium on the basis of a time interval when the patterns are detected by the first detection unit and a time interval when the patterns are detected by the second detection unit.

Abstract: An image forming apparatus that can reduce the time required for adjustment operations when a first adjustment operation that requires speed change and a second adjustment operation that does not require speed change overlap. When a first adjustment operation that can be performed at a first speed is to be performed during operation at a second speed lower than the first speed, the image formation speed is changed from the second speed to the first speed. When a second adjustment operation that can be performed at a plurality of image formation speeds is to be performed during operation at the second speed, the second adjustment operation is performed while maintaining the second speed. When both the first adjustment operation and the second adjustment operation are to be performed during operation at the second speed, the image formation speed is changed from the second speed to the first speed.

Abstract: A method is provided of determining the cause of artifacts in images produced by an electrophotographic (EP) printer. A reference image is printed and artifacts in it are detected. After printing normal images, a test image is printed and artifacts in it are detected. If a detected artifact in the test image does not correspond to a detected artifact in the reference image, a characteristic frequency spectrum of the artifact in the test image is determined. Run-out on rotatable imaging components is measured, and a characteristic frequency spectrum of each is determined. The test image spectrum is compared to each component spectrum to identify which component is causing the artifact.

Abstract: An image forming apparatus includes a two-component developing devices for each of a plurality of photoreceptors and a motor for the developing device. A transmission can assume a coupled state where the transmission transmits driving force of the motor to the developing device and a separated state where the transmission does not transmit the driving force of the motor to the developing device. A toner agitating mechanism stirs toner inside the developing device. A permeability sensor detects permeability inside the developing device and outputs a signal according to a ratio of the toner to the carrier. A coupling judging section judges that the coupling state exists when a variation of a signal value outputted by the permeability sensor equals or exceeds a predetermined value and judges that the separated state exists when the variation of the signal value outputted by the permeability sensor is lower than the predetermined value.

Abstract: An image forming apparatus for controlling power supply is provided. An image forming apparatus includes at least one cover unit to be mounted in the image forming apparatus, at least one replaceable unit to participate in an image forming operation of the image forming apparatus, a sensing unit to sense whether the at least one cover unit is opened or closed, and a main board unit to cut off the power supply to the at least one replaceable unit for a predetermined period of time when the at least one cover unit is opened or closed. Accordingly, stable operation is enabled.

Abstract: An image forming apparatus including: an output image forming section for forming an image and a pattern on a supporting medium under a prescribed condition; an output section for transferring the formed image on a recording sheet; a correction section for performing reading of the formed pattern and correcting the condition based on a result of the reading; and a correction control section for controlling operations of the output image forming section, the output section, and the correction section, wherein the correction control section identifies whether or not an area where the image is to be formed and an area where the pattern is to be formed overlap each other, and when the areas are identified that they do not overlap each other, the correction control section controls the output image forming section to simultaneously form the image and the pattern in parallel on the supporting medium.

Abstract: A length L of the test pattern string is determined so as to satisfy a condition L?{P?(Q1+Q2)}×V, where a time Q is a total time of a time Q1 for which the test pattern string is transferred from an exposure position of the test pattern string to a sensor and a time Q2 from when the test pattern is detected by the sensor until a color misregistration correction value calculated on the basis of a result of detecting is reflected in image formation; a time P is a time from a timing of starting to write the test pattern string to a timing of starting to write an image in which the correction value should be reflected; and a driving speed of a second image carrier is V.

Abstract: Patch detection ATR control is executed each time image formation of a predetermined number of sheets is performed, and a replenishment quantity of a replenishment developer to be supplied from a hopper (31) is corrected so that a toner charge amount of a developer included in a developing device (4) becomes closer to a target toner charge amount. Further, Dmax control is executed each time a predetermined number of times of control for correcting the replenishment quantity of the replenishment developer are performed, and a development contrast used for the image formation is set so that a developed toner image attains a maximum density of an output image. A control portion (110) changes the target toner charge amount based on a density of a patch formed in accordance with the Dmax control.

Abstract: An image forming apparatus includes plural toner adhered amount detectors that detect an amount of toner particles adhered to the toner image on the image bearer and an image density controller to form a gradation pattern by sequentially arranging plural toner patches in the sub-scanning direction on the image bearer from the least toner adhered amount patch. These toner patches bear a different amount of toner particles from each other. The plural toner patches are detected by the plural toner adhered amount detectors, and the image density controller adjusts an image formation condition for the image formation device based on detection values thereof. These toner adhered amount detectors are symmetrically aligned in a main scanning direction above the image bearer. The image density controller forms the plural toner patches being staggered at different positions on the image bearer, facing these toner adhered amount detectors, respectively.

Abstract: An image forming apparatus includes an imaging unit configured to form pattern images in areas corresponding to positions at which toners including a specific color toner of a specific color are provided; a reading unit configured to read the formed pattern images; a color information detection unit configured to analyze color information of the read pattern images and detect the color information of the specific color toner; a position determination unit configured to determine the position at which the specific color toner is provided from a position at which the pattern image of the specific color is formed in the read pattern images; and a recording unit configured to record the detected color information of the specific color toner and the position at which the specific color toner is provided.

Abstract: In a method or system for processing a measurement signal to detect a property of a toner mark, the toner mark is generated with aid of an image generation device. The toner mark is detected with aid of a measurement unit in that sample values determined by the measurement unit at sample points in time are output as the measurement signal for detecting the property of the toner mark. A function is determined to describe at least one part of a signal curve of the measurement signal on a basis of at least one part of the output sample values. At least one extreme value of the function is determined.

Abstract: An image forming apparatus includes a charging unit, an image carrier, an exposing unit, a developing unit, a transfer belt on which the transfer material is placed, a fixing unit that fixes the toner image transferred onto the transfer material, a cleaning unit that cleans up toner attached to the fixing unit, and a control unit that controls printing of the image on the transfer material. The control unit causes the exposing unit to expose a latent image of a first image having an image-area ratio equal to or larger than a predetermined ratio, causes the developing unit to form a toner image of the latent image and to transfer the toner image to the transfer material, and causes the fixing unit to fix the toner image transferred by the transfer belt to the transfer material.

Abstract: An apparatus includes an image formation unit including a photosensitive drum and a motor for driving the image formation unit. The apparatus acquires a frequency generator signal, which is phase information output from the motor as the motor rotates. In addition, the apparatus corrects unevenness of the density that may occur due to the rotation of the motor according to the acquired phase information.

Abstract: A belt device includes an endless belt including at least a base layer and a coat layer, the coat layer formed on the base layer and configuring an upper most surface of the belt; a driving member that rotates the belt and that is provided at one end of the belt to bias an inner circumferential surface of the belt; and a driven member that rotates the belt and that is provided at other end of the belt to bias the inner circumferential surface of the belt. Wherein the base layer has a mirror specularity of 20-60.