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

Abstract: A misregistration correcting device includes an image forming unit, a sensor, a reading unit, and a determining unit. The image forming unit form a set of misregistration correcting patterns that includes a reference pattern. The sensors start detecting the set when a predetermined time has elapsed after start of image formation for the first set. The reading unit reads positional information of the set upon detection of the set. The determining unit determines timing to start detecting subsequent sets of misregistration correcting patterns based on positional information of the reference pattern in the first set.

Abstract: The calibration of an imaging system is adjusted for geometric distortion of an image formed by a group of imaging channels on a media supported on a media support. The media support includes a plurality of individually spaced reference features disposed on a surface of the media support and a change in an expected position of at least one of the reference features is determined. Activation timing of the channels is adjusted in accordance with such changes. The imaging channels can be supported on a movable carriage and movement of the carriage can be adjusted in accordance with such changes.

Abstract: An optical writing device that forms an electrostatic latent image on a photoreceptor. The device includes a pixel-information acquiring unit, a line-pixel-information storage unit that stores the acquired pixel information corresponding to a plurality of lines for each main scanning line, a light source device that exposes the photoreceptor with a period corresponding to an N-fold sub-scanning direction resolution of the pixel information, a positional-shift-information storage unit that stores a positional shift information, a sub-line counting unit that counts a sub-line period, a reading-line selecting unit that performs N times of selection that determines which main scanning line is selected as the line from which the pixel information is read out, on the basis of a calculated value from the counted value of the sub-line period and the positional shift information, and a pixel-information reading unit.

Abstract: First patterns for setting a first adjustment value and second patterns for setting a second adjustment value are formed on a transfer belt running at a first process speed. By this, an image shift adjustment value in a sub-scanning direction is made common to the first process speed and a second process speed. Image shift adjustment values in a main scanning direction are set for the first process speed and the second process speed, respectively.

Abstract: An image forming apparatus comprises: an exposure unit configured to irradiate each of a plurality of photosensitive members with a light beam, a light amount control unit configured to control a light amount of the light beam, a plurality of developing units configured to develop electrostatic latent images, formed on the plurality of photosensitive members by exposure with the light beams, and a transfer unit configured to transfer toner images formed on the plurality of photosensitive members onto an image carrier; a pattern forming unit configured to control the image forming unit to form, a misalignment detection pattern for detecting a relative misalignment between the toner images transferred onto the image carrier; a pattern reading unit configured to read the misalignment detection pattern; and a correction unit configured to correct the relative misalignment between the toner images based on the reading result obtained by the pattern reading unit.

Abstract: A method for compensating misalignment errors associated with a laser beam in an electrophotographic (EP) device is disclosed. A first value and a second value of a time-of-flight of the laser beam are determined. The second value of the time-of-flight is associated with a current value of SOS time and EOS time of the laser beam. The second value of the time-of-flight of the laser beam is compared with the first value of the time-of-flight. A duty cycle of a fuser of the EP device is monitored. An average value of the duty cycle of the fuser for a predetermined time period is determined. One or more alignment conditions of the laser beam are adjusted based on at least one of the comparisons of the second value and the first value of the time-of-flight of the laser beam, and the determined average value of the duty cycle of the fuser.

Abstract: A determining unit determines whether a difference between a temperature value and a temperature detected by a temperature detecting unit is equal to or larger than a first value. A pattern forming unit, when the determining unit determines that the difference is equal to or larger than the first value, forms a pattern for measurement including sub-patterns of a plurality of colors on a transfer medium. A calculating unit calculates a misregistration-amount for each sub-pattern based on a detected position of the sub-pattern and a predetermined position of the sub-pattern. A correcting unit corrects a position on which the sub-pattern is to be formed based on the misregistration-amount. An image forming unit forms an image for each color factoring in corrected position for each color.

Abstract: In an image forming apparatus, an image forming portion forms an image on a rotator. A first designating portion determines a first estimated phase point based on a base time point, and designate, as a designated parameter, a correction parameter corresponding to said first estimated phase point based on change characteristics information stored in a storage portion. A correcting portion corrects an image forming position on the rotator based on the designated parameter. A changing portion changes a value of the designated parameter into an adjusted value intermediate between the designated parameter and a reference parameter that is a correction parameter designated based on the time when the detecting portion detects the detecting phase point.

Abstract: The invention aims to provide an image forming apparatus digitally correcting curve and inclination of a laser beam. To this end, provided is an image forming apparatus that corrects a position shift of a scan line in a sub-scanning direction.

Abstract: An image forming apparatus generates a color image on a transfer belt by superimposing toner images of respective colors generated by image forming units, and transfers the color image onto a transfer medium. The image forming apparatus includes a correction pattern forming unit configured to form a correction pattern for correcting color misalignment on the transfer belt, a detection sensor configured to detect the correction pattern formed on the transfer belt by the correction pattern forming unit, and a correction control unit configured to control a width of the correction pattern in response to an output of the detection sensor produced by detecting the correction pattern.

Abstract: In a color marking assembly, a series or plurality of ROS-imaging station units are aligned above an endless image transfer belt. Since there are a plurality of units, image alignment between the several station units is important. To accomplish this, skewing of each of the stations is necessary. The present invention involves a fixed ROS unit and a movable or skewable imaging station. This imaging station is movable on at least three spheres, one sphere below the imaging station and on its inboard side, the other spheres are located on a track below the imaging station and on its outboard side. This arrangement reduces vibration of these stations while at the same time providing an easily skewable xerographic imaging station.

Abstract: An image forming apparatus includes a plurality of image forming units that form toner images in different color; an image carrier which carries the toner image of each color; a determination unit that determines, in relation to a size of image data instructed to print, whether or not a first area where a misregistration correcting image is formed at an end portion in a width direction of the image carrier is secured; a first control unit that controls the image forming unit; and a detection sensor that detects the misregistration correcting image formed on the image carrier by controlling of the first control unit; wherein the misregistration of the toner image formed by each image forming unit is corrected on a basis of a value detected by the detection sensor.

Abstract: An image forming apparatus includes first and second image bearing members on which toner images are to be formed, a conveying member, and a conveying member position index detecting device for detecting a conveying member position index provided on the conveying member. The apparatus also includes an image bearing member position index detecting device for detecting image bearing member position indices provided on the second image bearing member, an adjusting device for adjusting a rotational speed of the second image bearing member, and a controller for controlling the adjusting device so as to adjust a position of an image bearing member position index correspondingly to the conveying member position index, on the basis of detection results of the conveying member position index detecting device and the image bearing member position index detecting device.

Abstract: A color image forming apparatus including: an image forming section which forms an image based on image information on an image carrier provided in the image forming section; a detection section which detects a print mark for color misalignment correction formed on the image carrier by the image forming section, and outputs print mark detection information; and a control section for executing color misalignment correction control based on the print mark detection information outputted from the detection section, wherein, the control section obtains a trend of a color misalignment amount of the print mark by statistically processing data of the result of the print mark detection, calculates an execution timing of color misalignment correction base on the obtained trend, and executes the color misalignment correction at the calculated execution timing.

Abstract: An image forming apparatus includes an image forming unit that forms multicolor toner images superposed on a transfer belt. A sensor is disposed in an image formation region and detects a pattern on the transfer belt. A controller determines, when image data is received, whether or not a region of a toner image based on the image data will be superposed on a region of the pattern. The controller controls the image forming unit to form the toner image based on the image data and the pattern simultaneously on the transfer belt when the controller determines that the region of the toner image based on the image data will not be superposed on the region of the pattern.

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

Abstract: An image forming apparatus includes a transport part which includes a transport belt to transport a printing medium, an image forming part which transfers a toner to form a color image, and a controller which controls the image forming part to form a test image for color registration of the image forming part on the transport belt while an image is formed for a plurality of printing media. Thus, both a test image and a plurality of printed media are formed during a single printing process.

Abstract: An image forming method exposes image bearing members by simultaneously reflecting light beams from light sources, corresponding to different colors, by different reflection surfaces of a polygon mirror which has reflection surfaces and is rotated in one direction, transforms electrostatic latent images formed on each of the image bearing members into toner images for correction, transfers the toner images on each of the image bearing members in an overlapping manner onto a transfer body that is transported in a transport direction, and calibrates overlapping positions of the toner images based on an optical detection of the toner images on the transfer body. The toner images are arranged at positions on the transfer body such that the toner images of different colors have no overlap therebetween even if the toner images shift in a direction perpendicular to the transport direction due to a color registration error.

Abstract: An image forming method exposes image bearing members by simultaneously reflecting light beams corresponding to different colors by different reflection surfaces of a polygon mirror, transforms electrostatic latent images formed on the image bearing members into toner images for correction, transfers the toner images in an overlapping manner onto a transfer body, and calibrates overlapping positions of the toner images based on an optical detection of the toner images. The toner images are arranged at positions on the transfer body such that the toner images of different colors have no overlap therebetween, even if the toner images shift in a direction perpendicular to the transport direction due to a color registration error.

Abstract: An image forming apparatus includes a photoconductor drum, a first printer head that forms a first pattern on the photoconductor drum and has a first end part, a second printer head that forms second and third patterns on the photoconductor drum and has a second end part that overlaps the first end part in a main scanning direction, a detection sensor that detects the densities of first and second test patterns formed at an area of the photoconductor drum at which the first and second end parts overlap, the first test pattern being formed by combining the first and second patterns, the second test pattern being formed by combining the first and third patterns, and a determination part that determines a deviation direction between the first and second printer heads by comparing the densities detected by the detection sensor.

Abstract: When an instruction reception section receives an image forming instruction from an operator, a detector detects an toner image forming unit which performs an image forming operation in connection with the operator's instruction. A mode determining section determines which one of an image formation preceding mode or a sheet conveyance preceding mode is set for the toner image forming unit detected by the detector, and a drive controller controls drivings of the sheet conveying section and the image forming section according to the determined mode.

Abstract: An image forming apparatus that includes a plurality of image bearing members, a plurality of drive sources each including a drive gear, a plurality of driven gears, a visible image forming unit, an endless traveling member, a transfer unit, an image detection unit, and a controller. The controller controls rotation of the plurality of image bearing members according to a velocity fluctuation pattern of each surface of the image bearing members based on a detection time interval between predetermined visible detection images formed on the surface of the image bearing member and transferred therefrom to the endless traveling member detected by the image detection unit. Each of the plurality of driven gears includes a gear portion and an engaging portion integrated therewith. The gear portion includes a geared circumference and the engaging portion engages the image bearing member.

Abstract: An image forming apparatus forms a latent image on a photoconductor by irradiating light beams from a plurality of light sources onto the photoconductor. A detection unit detects a time difference between timings of start writing on the photoconductor by the light beams in a main scanning direction. A calculation unit calculates a shift of each of the light beams in a sub-scanning direction based on the time difference detected by the detection unit and a rotation speed of the photoconductor. A correction unit corrects irradiated positions on the photoconductor by the light beams in the sub-scanning direction based on the shift calculated by the calculation unit.

Abstract: A deviation amount detecting device for use in an electrophotographic color image forming device is configured to detect whether a deviation for each of toner images of different colors on a transporting member takes place, based on position information which is stored as a result of reading of a first set of deviation detecting patterns by a pattern reading unit.

Abstract: An image forming apparatus is capable of more accurately detecting the relationship between an actual amount of color deviation and an estimated amount of color deviation. The image forming apparatus forms a color deviation detection mark at timing when the estimated amount of deviation reaches a threshold value. The timing is different from the timing when it is determined that it is necessary to perform normal calibration. The image forming apparatus determines the relationship between the actual amount of deviation of an image forming position from a reference and the estimated amount of deviation to set an estimating unit for estimating the amount of deviation.

Abstract: An optical scanning device 65 is adapted to bring a deflector mirror plane 651 into independent pivotal motions about a first axis and a second axis perpendicular to each other. A mirror driver section including a first axis driver and a second axis driver is so controlled as to bring the deflector mirror plane 651 into pivotal motion about the first axis thereby deflecting a light beam L for scanning along a main scan direction. On the other hand, the deflector mirror plane 651 is pivotally moved about the second axis thereby to adjust the scanned beam L for its position on a photosensitive member 2 with respect to a subscan direction. Thus, even if the scanned beam is deviated from a reference scan position with respect to the subscan direction due to component tolerances or assembly errors, such a deviation can be corrected.

Abstract: A transfer belt driving control method and transfer belt driving control apparatus for color registration correction. The color registration correction method and apparatus performs the color registration correction by setting a pattern forming section, in which patterns for the color registration correction are able to be formed, and a non-pattern forming section, in which the patterns are not able to be formed, on a transfer belt in which the patterns are formed, performing the color registration correction by driving the transfer belt at a first speed in the pattern forming section, and driving the transfer belt at a second speed, which is faster than the first speed, in the non-pattern forming section.

Abstract: An image forming method includes forming toner images on first and second image bearing members; transferring a first toner image on the first image bearing member and a second toner image on the second image bearing member, in mutually superposed manner, onto a recording material; heating the first and second toner image thereby fixing the same to the recording material; detecting alignment marks on the first and second image bearing members in the course of a continuous job for continuously forming images; controlling relative positions of the first toner image and the second toner image, based on a result of detection of the alignment marks; and increasing a frequency of execution of the relative position control in the continuous job, as the recording material to be subjected to image formation in the continuous job has a smaller width in a direction perpendicular to a transport direction of the recording material.

Abstract: Apparatus and methods for adjusting a skew angle of an LED array in the second of dual/tandem print engine systems to compensate for shrinkage of the printable medium exiting the first print engine. Features and aspects hereof provide for manually and/or automatically measuring the shrinkage of the printable medium as it exits the first print engine and for automatically and/or manually adjusting the skew angle of the mounting of the LED array in the second print engine. The image data applied through the LED to the corresponding photoconductor of the second print engine is similarly skewed to match the skew angle of the LED array. Thus a substantially normal bitmap image is applied through the skewed LED to the photoconductor of the second print engine shrunk in the width dimension. Visual artifacts and anomalies from the mathematical approximations and rounding are visually imperceptible at sufficiently high resolutions.

Abstract: An image forming apparatus is provided with a light scanning device that directs laser beams emitted from a plurality of laser light sources on to a plurality of photoconductive members via focusing device which includes optical elements and a deflecting device that deflects the beams in a main scanning direction; an image forming device which forms visible images of different colors from images written onto the photoconductive members by the light scanning device; and an intermediate transfer member or a recording sheet transport member capable of carrying the visible images formed on the photoconductive members. When in detection mode, a control device controls the correction of color registration errors between each color forms patterns on an intermediate belt by an image forming device, detects the patterns by a color registration error detection sensor, and stores the color registration error correction values obtained from the detection output of the sensor in a memory device.

Abstract: An image forming apparatus includes an image forming unit configured to form a toner image on an image bearing member, an endless belt configured to transfer and carry the toner image thereon, a transfer unit configured to transfer the toner image carried by the endless belt onto a recording sheet, a sensing unit configured to sense the toner image transferred onto the endless belt, a blocking unit mounted between the sensing unit and the endless belt and configured to block the sensing unit, a contact and separation unit configured to cause the transfer unit to reciprocally contact and separate from the endless belt. With this configuration, the blocking unit and the contact and separation unit are configured to be driven by an identical drive source.

Abstract: If a velocity calculated by a velocity calculating unit deviates from a normal range, a target velocity is used as a feedback amount, an actuation amount corresponding to a deviation Ve=0 between the feedback amount Vf=Vt and the target velocity Vt is calculated, and a driving power corresponding to this actuation amount is supplied to a motor. A conveyor belt can be driven stably without causing irregularity in a speed of the conveyor belt.

Abstract: An image forming apparatus and image forming method capable of achieving both high-speed printing of less-than-full-color images and high quality printing of multicolor images. The apparatus includes a color shift pattern output unit, a correction amount acquisition unit, and a correction unit to correct at least one or more positions of an image in a sub-scanning direction on a recording medium when a first transfer member transfers an unfixed image and a second transfer member transfers an unfixed image.

Abstract: A color image forming apparatus in which a positional displacement detection image and a light quantity adjustment image are formed within a one-rotation length of an image bearing member (intermediate transfer belt). A light-emission quantity when detecting density is determined on the basis of a detection result of a light quantity adjustment image formed within the one-rotation length using light-emission quantity that is provided when light is emitted to the positional displacement detection image. This allows, for example, image density control to be performed quickly while precision of the image density control is maintained.

Abstract: An image processing apparatus that enables to embed a secure pattern code in an output image with an inexpensive configuration. An image reader has a color reference plate and reads image data of an original. An image forming apparatus forms an image on an image carrier based on the image data of the original. A laser controller irradiates the color reference plate with laser light. An image sensor controller reads a pattern image generated by irradiating the color reference plate with the laser light. The image forming apparatus adds data concerning the pattern image read by the image sensor controller to the image data of the original read by the image reader and forms an image based on the image data of the original to which the data concerning the pattern image is added.

Abstract: In an image forming apparatus for forming a color image by superposing component color images, a control device obtains position data representing a forming position of each of plural registration mark images for the component color images with respect to a positional reference value arbitrarily determined, divides the position data into each of a unit reference range representing a range in which one mark image is formed, converts the position data divided for each unit reference range into those based on respective reference values representing the front edge of the unit reference ranges, extracts the position data representing ranges common to the mutually overlapping ranges each of which is represented by a couple of position data corresponding to the rising and falling edges of a passage timing pulse as read position data of the mark image of the component color, and calculates the amounts of positional deviations of the component color images from one another on the basis of the position data extracted.

Abstract: In an image forming apparatus that forms a color image by transferring toner images for respective colors formed on plural rotary photoreceptor drums onto a sheet through an intermediate transfer member, when a controller judges that magnification deviation is generated in a main-scanning direction in superposition of the toner images for respective colors, the controller forms a first color registration deviation detecting mark for detecting at least an amount of deviation in the main scanning direction on the intermediate transfer member, and when the controller judges that the magnification deviation is not generated in the main-scanning direction in the superposition of toner images for respective colors, the controller forms a second color registration deviation detecting mark for detecting only an amount of deviation in a sub scanning direction perpendicular to the main-scanning direction on the intermediate transfer member.

Abstract: An image forming apparatus including a patch detection sensor for detecting an intermediate transfer belt and image information of toner images transferred onto the intermediate transfer belt, a distance measurement sensor for detecting the distance between a light emitting portion of the patch detection sensor and the surface of the intermediate transfer belt facing the patch detection sensor, and a control unit for correcting the image information detected by the patch detection sensor based on the distance information detected by the distance measurement sensor and controlling image forming conditions so as to correct at least one of density and color misregistration of toner images based on the corrected image information.

Abstract: An image forming apparatus, includes: a latent image carrier that moves in a first direction; an exposure head that includes a light emitting element and an imaging optical system row which is arranged in the first direction and which is made up of imaging optical systems which are arranged in a second direction different from the first direction and image light emitted from the light emitting element on the latent image carrier; a developing unit that develops a latent image formed on the latent image carrier by the exposure head; and two detectors that detect an image obtained by developing a latent image by the developing unit, the latent image being formed using the same imaging optical system row.

Abstract: An image forming apparatus including a plurality of detachable image forming devices each configured to form a color image, an image carrying device configured to carry the color images sequentially overlaid into a single color image, an exchange detecting device configured to detect an exchange operation of the plurality of detachable image forming devices, a test pattern reading device configured to read a predetermined test pattern formed by the plurality of detachable image forming devices on the image carrying device, and a controller configured to instruct the plurality of detachable image forming devices to form the predetermined test pattern on the image carrying device when the exchange detecting device detects the exchange operation, and to perform a color image position adjustment based on readings of the predetermined test pattern by the test pattern reading device.

Abstract: An image forming apparatus is provided. A second photoconductor is disposed at a downstream side of a first photoconductor in a moving direction of a medium. First and second exposure units form first and second electrostatic latent images on the first and second photoconductors line by line at first and second exposure timing intervals in first and second exposure enabling time periods based on successive lines of first and second image data, respectively. A correction unit corrects at least one of the first and second exposure timing intervals. A change unit changes the second exposure enabling time period so as to suppress a difference between the number of the successive lines of the first image data and the number of the successive lines of the second image data.

Abstract: A high-quality image forming apparatus that is capable of accurately adjusting the size and position of an image during image formation on a second surface of a transfer material, even when there has been expansion/contraction of the transfer material due to thermal fixing after image formation on a first surface thereof, to thereby avoid image displacement during two-sided image formation and multiple image formation.

Abstract: An image-forming device includes a conveying unit and a pattern data generating unit. The conveying unit conveys a target in a conveying direction, the target having a target light reflectance. The pattern data generating unit generates pattern data indicating a pattern in which a plurality of marks is arranged in the conveying direction. The plurality of marks includes a first mark having a first color and a first light reflectance and a plurality of second marks having a plurality of second colors and a plurality of second light reflectance. The plurality of second colors is equal to or different from one another. The plurality of second light reflectance is equal to or different from one another. A first difference between the target light reflectance and the first light reflectance is greater than a second difference between the target light reflectance and any of the plurality of second light reflectance.

Abstract: An image forming apparatus includes an image forming unit that forms multicolor toner images superposed on a transfer belt. A sensor is disposed in an image formation region and detects a pattern on the transfer belt. A controller determines, when image data is received, whether or not a region of a toner image based on the image data will be superposed on a region of the pattern. The controller controls the image forming unit to form the toner image based on the image data and the pattern simultaneously on the transfer belt when the controller determines that the region of the toner image based on the image data will not be superposed on the region of the pattern.

Abstract: This invention enables an image forming apparatus to perform highly precise misregistration detection without causing increased downtime or increased cost. For this, the image forming apparatus according to the invention comprises a detection unit for detecting a misregistration detection pattern formed on an endless belt. The employed misregistration detection pattern includes a first pattern array formed with a misregistration detection color or a reference position color, and a second pattern array formed with a misregistration detection color or a reference position color. The misregistration detection pattern is configured in a way that the first pattern and the second pattern have different shapes, and that the color order of the first patterns in the first pattern array and the color order of the second patterns in the second pattern array are different.

Abstract: A system for adjusting selected operating parameters of an image forming device to improve color registration based on selected environmental conditions includes a first image forming station to print a first registration mark on a substrate, a second image forming station to at least partially erase the first registration mark to form a registration pattern in a reverse transfer process of the color registration, and a control mechanism to adjust voltage biases of charge and developer rolls of the second image forming station based on wet-bulb temperature values determined from measured dry-bulb temperature and relative humidity values and stored in a lookup table so as to maintain a predetermined potential difference between charged and uncharged areas of a PC drum of the second image forming station that avoids Paschen breakdown and the development of toner at charged areas of the PC drum during the reverse transfer process of the color registration.

Abstract: In a method for automatically identifying a conveyor belt in a printer as being one of a plurality of belt types, the conveyor belt is moved along a circulatory path. A start and an end of a longitudinal marking on the moving conveyor belt are detected. A distance of travel of the moving conveyor belt between the detecting of the start and the end is sensed to provide a sensed marking length. The sensed marking length is allocated to a nearest of a plurality of nominal marking lengths. Each nominal marking length is associated with a respective one of said belt types. The belt type is associated with or defined by a set of one or more printer control parameters.

Abstract: Systems and methods are provided for correcting color registration errors in a printing device comprising a plurality of print engines driven by a single pixel frequency clock. In some embodiments, the print engines can include a reference print engine and one or more non-reference print engines. An adjusted resolution may be computed for color data sent to each non-reference engine to offset color registration errors attributable to the non-reference engine. The adjusted resolution is computed using calibration information for the non-reference print engines relative to the reference engine, and resolution information for color data processed by the first reference engine. The resolution of color data processed by each non-reference print engine is adjusted according to the computed adjusted resolution for the non-reference engine and sent to the print engines for printing.

Abstract: An image forming apparatus, includes: an exposure head that includes a plurality of imaging optical systems which are arranged in a first direction and a plurality of light emitting elements which emit lights to be imaged by the imaging optical systems; a latent image carrier that moves in a second direction orthogonal to or substantially orthogonal to the first direction and carries a latent image formed by the exposure head; a developer that develops the latent image; and a detector that detects an image developed by the developer, wherein the image detected by the detector has a width in the first direction wider than that of an image formed by one imaging optical system.