Abstract: An electrophotographic image forming apparatus has a controller configured to store a rotation amount of a motor since the tray is attached to a main body of the image forming apparatus as a stored rotation amount, and move, in response to receipt of a print instruction, a pressing plate by driving the motor in the first mode when a remaining rotation amount is equal to or larger than a particular threshold rotation amount, the remaining rotation amount being a difference between a target rotation amount which is a rotation amount necessary to move the pressing plate from a position when the tray is attached to the main body to the conveying position, and the stored rotation amount, or in the second mode when the remaining rotation amount is less than the particular threshold rotation amount.

Abstract: A sheet-edge detecting device includes first and second detecting units and a determining unit. The detecting units are disposed at an edge of a sheet having feed holes in a direction crossing a transporting direction of the sheet, and are separated from each other in the transporting direction so as not to be positioned in one or more feed holes simultaneously. In the direction crossing the transporting direction, the detecting units are separated from each so as not to be positioned in a feed hole and outside the edge simultaneously, one of the detecting units is at a position corresponding to an allowable displacement of the edge, and the other detecting unit is at the same position as the one of the detecting units or closer to the edge than the one of the detecting units is. The determining unit determines the position of the edge of the sheet.

Abstract: A printer device has a two-sided printing function and a circulatory transporting path for transporting a printing medium. The printer device is configured such that after creating a set of print data for a first recording surface to be printed with two-sided printing, the printer device adds a set of dummy print data for a second recording surface corresponding to a back side of the first recording surface to the set of print data for the first recording surface.

Abstract: A document feeding device has: a document placement stand on which documents of different sizes can be placed; a conveying section separating, one-by-one, documents of a document stack placed on the document placement stand, and conveying a separated document to a discharging section; a first document width sensing unit sensing a maximum document width of the document stack placed on the document placement stand; a second document width sensing unit sensing a document width of a document separated from the document placement stand by the conveying section; and a controller that, in a case in which a mixed size document mode that permits conveying of documents of different sizes is not set, causes the conveying section to restartably interrupt conveying of the document when the maximum document width sensed by the first document width sensing unit and the document width sensed by the second document width sensing unit differ.

Abstract: In a ticket printer, an end of a paper sensor has an optic emitter and receiver arranged one after the other in the paper advancement direction and operationally connected together via a signal guide. The emitter and the receiver are arranged on one side of the path of the paper whereas the signal guide is arranged on the opposite side.

Abstract: An image forming apparatus includes an image forming unit forming an image on a recording sheet; a transport unit transporting the recording sheet; a support surface supporting the recording sheet; a rotating member having an outer peripheral surface pressed against the support surface and rotationally following the recording sheet when the recording sheet passes through between the support surface and the outer peripheral surface; an ascertaining unit ascertaining a length of the recording sheet on the basis of an amount of rotation of the rotating member; and a restricting unit restricting a movement of the rotating member that moves toward the support surface after the recording sheet passes through between the support surface and the outer peripheral surface, the restricting unit preventing the outer peripheral surface, which comes into contact with the recording sheet, and the support surface from coming into contact with each other.

Abstract: A recording medium placement device includes a placement unit in which a recording medium is placed; a guide member provided along an edge of the recording medium and movable in a first direction orthogonal to the edge, the edge being at a first position; a distance detection unit that detects a distance between the guide member and the edge; a drive unit that moves the guide member in the first direction until the distance detection unit detects that the guide member contacts the recording medium; a gap length calculation unit that calculates a length of a gap between the recording medium and the guide member when a movement of the guide member is stopped using a detection output from the distance detection unit; and an adjustment unit that moves the guide member to the edge at the first position based on the length of the gap.

Abstract: The printing apparatus for printing at least an address on an envelope that is set to a paper tray includes an envelope size detection portion for scanning an address print side of an envelope set to the paper tray to detect a size of the envelope based on a read image of the address print side; a print position setting portion for setting a print position of an address corresponding to the read size of the envelope; and a data synthesis processing portion for synthesizing the read image of the address print side and an image of the address at a position set by the print position setting portion and previews the synthesized address print image of the envelope on a display device.

Abstract: A paper position sensor for a ticket printer is disclosed. The ticket printer includes a blank ticket tray and a paper guide consisting of an upper and lower guide, which lower guide contains a position sensor wheel that rotates as a result of the frictional contact with the blank ticket, as the ticket passes over the sensor wheel on its way through the guides. The wheel contains an embedded magnetic element such that as the wheel turns, which magnetically provides rotational position information to an adjacently-mounted sensor chip, which is able to determine, magnetically, the position of the wheel. The sensor chip provides data to the printer control as to the position of the ticket through the printer, and thus the printer control is now able to determine the precise position of the ticket in the printer.

Abstract: A sheet sensing module and a duplex scanning apparatus having the sheet sensing module are provided. The sheet sensing module includes a first sensing arm, a second sensing arm, and an electronic sensor. The first sensing arm is partially exposed to a sheet feeding channel of the duplex scanning apparatus. The second sensing arm is partially exposed to an inverting channel of the duplex scanning apparatus. When a document is transferred through the sheet feeding channel to trigger said first sensing arm or the document is transferred through the inverting channel to trigger the second sensing arm, the electronic sensor generates a sensing signal.

Abstract: An image forming apparatus includes a cassette chamber, a paper feed cassette, a sheet size sensor, a lift-up sensor, and an arithmetic control unit. The paper feed cassette can be mounted in the cassette chamber, and lifts up a recording sheet placed in the paper feed cassette upon being mounted in the cassette chamber. The arithmetic control unit is configured to decide that the paper feed cassette is mounted when the lift-up sensor detects that the recording sheet is lifted up, despite the sheet size sensor having detected that the paper feed cassette is not mounted.

Abstract: An image reading apparatus to convey a sheet to be scanned to an image reader unit is provided. the image reading apparatus includes a sheet tray, in which the sheet to be scanned is stored, a separator, which frictionally picks up the sheet from the sheet tray and conveys the picked-up sheet toward an entry side of the image reader unit, through which the sheet enters a position above the image reader unit, to have a first side of the sheet scanned by the image reader unit, and a resisting force applier, which applies convey-resisting force to the sheet, of which first side has been scanned, being returned to the entry side of the image reader unit to have a second side of the sheet with the convey resistance scanned by the image reader unit.

Abstract: An automatic document feeder includes a document stack unit; a conveying unit configured to separate a document from the documents stacked on the document stack unit and convey the document to a scanning position through a conveying path; document detecting units configured to detect the document; an upstream document detecting unit configured to detect the document, the upstream document detecting unit being arranged in the conveying path at an uppermost stream in a document conveying direction with respect to the document detecting units; and a determining unit configured to determine a passage of a trailing end of the document at positions of the document detecting units and the upstream document detecting unit and determine a presence of a hole on the document, based on the detection results. A detection range of the upstream document detecting unit is set to be wider than detection ranges of the document detecting units.

Abstract: A mechanism for scanning and capturing digital images using document layer detection. Upon detecting a document placed on a scanning surface of a scanning device, the illustrative embodiments identify one or more layers within the document. The illustrative embodiments then scan the one or more layers within the document on a layer by layer basis.

Abstract: An image reader includes a path switching part, located at a branch point that switches between a double-sided path and a single-sided path. The double-sided path defines a conveyance route that passes through a reading position from the branch point to enter a conveyance path that causes a document to make a U-turn, and then again passes through the reading position to be discharged to a paper discharge tray. The single-sided path defines a conveyance route that, without passing through the reading position, merges into the conveyance path from the branch point. Along the double-sided path, document detecting sensors provide detection results so that a collision determination part determines a possibility of a collision between documents, and if such a possibility is determined, the path switching part switches the double-sided path to the single-sided path to prevent the documents from colliding head-on with each other in the vicinity of the reading position.

Abstract: An image reader and document conveying method shorten times necessary for a discharge process that discharges a document in being conveyed and for an idle feeding process of a document that is left on a paper feed tray. If during double-sided reading, a stop key is operated to issue an instruction to cancel reading, a conveyance controller outputs a path specifying signal to select a single-sided path, and thereby a conveyance route is switched from a double-sided path to the single-sided path. For this reason, the discharge process that discharges a document being conveyed at the time of the reading cancellation to a paper discharge tray, and the idle feeding process that discharges a document left on a paper feed tray to the paper discharge tray are performed with use of the single-sided path that is shorter than the double-sided path, and therefore the times necessary for the discharge and idle feeding processes can be shortened.

Abstract: An image reading apparatus including a reading unit that reads a document as an object to be read in a main scanning direction; a conveyance unit that conveys one of the reading unit and the object to be read as an object to be conveyed in a sub-scanning direction; a detecting unit that detects a position of the object to be conveyed; a control unit that controls conveyance of the object to be conveyed, based on the position of the object to be conveyed and a preset target position trajectory; a specifying unit that specifies, based on the target position trajectory, the position of the object to be conveyed at a time when a period of invalidation or interruption of reading operation by the reading unit is started. The reading operation is invalidated or interrupted when a predetermined interruption condition is satisfied.

Abstract: A CPU checks a detecting state of a document set sensor at a point when the trailing end of a document sheet is assumed to pass through a separating position at which the document sheet is separated by a separation roller, based on a document length determined based on a detecting output from an abutting sensor. If the document set sensor does not detect a document sheet, the CPU determines that the next document sheet is not present. If the document set sensor detects a document sheet, the CPU checks a detecting state of the document presence detecting sensor. If the document presence detecting sensor detects a document sheet, the CPU determines that the next document sheet is present.

Abstract: An image reading apparatus includes a feeder, a first reading unit, a first memory which stores image data of the surface of the document read by the first reading unit, a second reading unit located at an upstream side of the first reading position, a second memory which stores image data of the document read by the second reading unit and a controller configured to control the feeder, the first reading unit and the second reading unit. The controller controls to execute pre-scanning the document by the second reading unit over a predetermined range shorter than a separation distance between the first reading position and the second reading position in a transporting direction from a leading edge of the document when the document reaches the second reading position. The controller further controls to execute storing obtained pre-scanned image data into the second memory and measuring the size of the document based on the pre-scanned image data stored in the second memory.

Abstract: A sheet conveyance device includes a loading section, a first conveyance member a separation section, a first sheet length detector to detect whether the sheet is longer than a predetermined length slightly longer than a specific sheet size in the sheet conveyance direction, a trailing-edge detector disposed downstream from the separation section, a leading-edge detector disposed downstream from the trailing-edge detector a distance smaller than the specific sheet size and from the first conveyance member a distance longer than the specific sheet size, and a controller. When the sheet is equal to or greater than the predetermined length, the controller starts sheet feeding when the trailing-edge detector detects the trailing edge of the sheet, and when the sheet is smaller than that, the controller starts sheet feeding when either the leading-edge detector detects the leading edge of the sheet or the trailing-edge detector detects the trailing edge thereof.

Abstract: There is described an image forming apparatus, which makes it possible to prevent a final print product from getting its appearance worse due to such a drawback that a reference mark still remains on the final print product. The apparatus includes: a setting section to make the display section display a setting screen for inputting setting information therefrom, the setting information being in regard to a post-processing use page including a reference mark to be used for post processing; an image processing section to create image data representing a second image of the post-processing use page, based on the setting information inputted from the setting screen; and a print processing section to print the first images of the pages included in the document and the second image of the post-processing use page onto first paper sheets and a second paper sheet being separate from the first paper sheets, respectively.

Abstract: There is provided a data processing device that includes an obtaining unit that obtains a first image data set, a second image data set generated by reading an image formed using the first image data set, and a property data set indicating the properties of a recording medium on which the image is to be reproduced. The data processing device also includes a specifying unit that determines a threshold for a density difference between the first image data set and the second image data set, wherein the threshold depends on the property data set. The specifying unit also determines an error area where the density difference between images expressed by the first and second image data sets is equal to or greater than the threshold.

Abstract: A sheet feeder for transporting a sheet unreeled from a roll includes a feed roller to unreel the sheet from the roll, a registration roller to transport the sheet unreeled by the feed roller to the image forming unit, a pressure roller pressing against the registration roller, forming a registration nip together with the registration roller, a movable sheet guide to guide the sheet to the registration roller, disposed between the feed roller and the registration roller in a sheet conveyance path, a support member to movably support the movable sheet guide relative to an apparatus body in which the sheet feeder is disposed, and a bias member to bias the sheet guide toward the sheet. The movable sheet guide wraps more of the sheet around the registration roller as a degree of tension of the sheet increases by moving against a bias force exerted by the bias member.

Abstract: An automatic sheet feeder includes a sheet setting unit to set a sheet to be fed by a sheet feeding member, an openably closable cover rotatably disposed over an upper portion of the sheet setting unit, a sheet detector rotatably supported on the cover to detect whether or not a sheet is set on the sheet setting unit and including a detection member, a rotary shaft about which the detection member rotates, and a sensor to detect the setting of the sheet according to a movement of the detection member, and a rotating member to cause the detection member to rotate in a direction such that an angle between a line extending in a longitudinal direction of the detection member and a surface of the sheet set on the sheet setting unit decreases as the cover rotates from an open position to a closed position.

Abstract: In a method for reading a document set on a document positioning plate to output image data, an edge area of an image of an entire reading area is extracted to form a first rectangle area including the extracted edge area. If a position of an apex of the first rectangle area farthest from a reading reference position and a size of the first rectangle area satisfy predetermined conditions, image data corresponding to a second rectangle area including the first rectangle area and the reading reference position are output.

Abstract: A disclosed image scanning device includes a document table; a document pressing unit configured to press a document placed on the document table; a scanning unit including a light source for illuminating the document and configured to optically scan the document; a photoelectric conversion element; an open/close detection unit configured to detect opening and closing of the document pressing unit; and a control unit configured to turn on the light source of the scanning unit and thereby to cause the photoelectric conversion element to detect a size of the document if the closing of the document pressing unit is detected by the open/close detection unit or if a scanning start signal is detected. The control unit is configured to turn on the light source after a lighting delay period from a time when the closing of the document pressing unit is detected. The lighting delay period is changeable.

Abstract: A sheet size detecting apparatus having a first arm moved by a moving sheet contacting therewith, a second arm moved by the moving sheet contacting therewith, the second arm being disposed at a location differing from that of the first arm in a direction orthogonal to the movement direction of the sheet, and a sensor, wherein the output level of the sensor when only one of the first arm and the second arm has been moved is the same as the output level thereof when neither of the first arm and the second arm is moved, and the output level of the sensor when both of the first arm and the second arm have been moved differs from the output level thereof when neither of the first arm and the second arm is not moved. Thereby, the cost can be suppressed and yet, the wrong detection of the sheet size can be prevented.

Abstract: A system for processing documents having fastening devices includes a document transport system and a fastening device detecting station connected to the transport system that is adapted to detect a fastening device securing together pages of a document. The fastening device removing station is adapted to remove a fastening device securing together pages of a document. A scanning station is adapted to scan the pages of a document. A page flipping station is adapted to flip and position pages of a document to be scanned. A systems controller controls the transport system and the stations based on information provided by the fastening device detecting station for a document to be scanned, to cause such document to be processed by the fastening device removing before scanning of the document or by the page flipping station during scanning of the document to be scanned.

Abstract: An image scanning apparatus according to the invention includes: a scanning unit configured to scan each of plural images from plural originals that are inputted; a rotation designating unit configured to designate rotation of the plural images that are scanned, so that an orientation of the plural images that are scanned coincides with a desired image orientation; a first image rotating unit configured to rotate the image that is scanned, in accordance with the designated rotation of the image; an orientation determining unit configured to determine whether the image orientation rotated by the first image rotating unit coincides with the desired image orientation or not; and a second image rotating unit configured to, for an image determined as not coinciding by the orientation determining unit, further rotate the orientation of the image so that the orientation coincides with the desired image orientation.

Abstract: In one implementation, a method scans a media to provide a first image and a second image. The method further subtracts the first image from the second image.

Abstract: An image scanning apparatus comprises a platen surface which is provided at an upper part of a main body of the image scanning apparatus so that an original sheet to be scanned is placed thereon; and an original sheet support portion which is provided to support an original sheet having a larger size than the platen surface. The original sheet support portion is provided to protrude laterally from the main body in a position under the platen surface to be able to support an end portion of a protruding portion of the original sheet protruding outside from the platen surface.

Abstract: The printing apparatus of the present invention comprises a scanner unit for reading an image in an original; an instruction unit for receiving an instruction from a user and instructing operation of reading the image with the scanner unit; and a printer unit for printing the image that has been read on a medium. In the printing apparatus of the present invention, each reading operation with the scanner unit is started by receiving an instruction from the user with the instruction unit when the reading operation is to be performed with the scanner unit for a plurality of number of times and a plurality of the images that have been read are to be printed in their respective predetermined positions on the medium. The printing apparatus makes it possible to perform N-up printing of a new procedure that is different from conventional N-up printing.

Abstract: In a method for reading a document set on a document positioning plate to output image data, an edge area of an image of an entire reading area is extracted to form a first rectangle area including the extracted edge area. If a position of an apex of the first rectangle area farthest from a reading reference position and a size of the first rectangle area satisfy predetermined conditions, image data corresponding to a second rectangle area including the first rectangle area and the reading reference position are output.

Abstract: A double side image scanner includes a case having a medium guide track with a reference loading line, a main frame mounted inside the case, a first roll feed including a first feed roller mounted on a front side of the guide track and a first idle roller disposed above the first feed roller for cooperating with the first feed roller to load the medium, a second roll feed including a second feed roller mounted on a rear side of the guide track and a second idle roller disposed above the second feed roller for cooperating with the second feed roller to load the medium, a drive device for rotating the first feed roller and the second feed roller, first and second image sensors for scanning opposite surfaces of the medium to acquire image data, and a tracking device for biasing the medium toward the reference loading line.

Abstract: An image reading apparatus having a color line sensor and a monochromatic line sensor starts to read on the basis of the color reading start position when reading the image of a document in color and starts to read on the basis of the monochromatic reading start position when reading the image of a document in monochrome.

Abstract: A document feeder for transporting a document to a predetermined reading position at which image reading is performed by an image reading portion, including: a document transport portion for transporting the document to a reading standby position upstream of the reading position; and a control portion for controlling the document transport portion so that the document is made to stop at the reading standby position if the image reading portion is not in an image readable state by the time the document arrives at the reading standby position.

Abstract: Correction patterns are formed on a conveyor belt that conveys a transfer paper. The correction patterns are include positional-deviation correction patterns arranged at both sides of the conveyer belt and density correction patterns (patches) formed in the central region of the conveyer belt in the main scanning direction.

Abstract: A document feeder includes: a document tray on which documents to be scanned are placed; a discharge tray onto which a scanned document is discharged; and a conveyance unit that conveys a document from the document tray to the discharge tray such that the document is caused to pass through an image-scanning position, the conveyance unit having: a first conveyance roll that supplies a document to the image-scanning position; a second conveyance roll that conveys a document that has passed the image-scanning position further downstream; a third conveyance roll that discharges a scanned document to the discharge tray; a driving force transmission mechanism that causes the first conveyance roll, the second conveyance roll, and the third conveyance roll to rotate relative to each other; and a document feeding operation member provided at a rotational shaft of the third conveyance roll, that is manually operated to rotate the rotational shaft.

Abstract: A document feeder includes a bidirectional feed path having both ends connected to predetermined positions of the bidirectional feed path, respectively. A document is fed from a downstream side of the image reading position to an upstream side with leading end and trailing end being reversed. The driving force is not transmitted when the rotation of the rotating member of the driving source is switched from one direction to the other, while the driving force is transmitted when an actuator is operated based on the driving system being rotated in the other direction. The actuator is actuated when the driving system is rotated in the other direction and the document is drawn in the bidirectional feed path. If the rotated amount of the driving source during the actuation of the actuator is less than a predetermined value, the actuator is actuated by a predetermined period.

Abstract: The method or system for controlling a printing or copying system for processing single sheets, a first single sheet and at least a second single sheet immediately following the first single sheet is processed with aid of n processing units. A required minimum distance between the first and the second single sheet is determined for each processing unit. A delay distance is determined for the first and at least for each of the n?1 following processing units. A difference between the minimum distance of a processing unit and a sum of the delay distances of the preceding processing units is formed. A smallest possible distance with which the second single sheet is fed to the first processing unit after the first single sheet is determined by a highest value of the determined minimum distance of the first processing unit and the determined differences.

Abstract: An image reading apparatus including: first reading sensor to read an image of an original document at a first position; a second reading sensor at second position downstream; a circulating transport path; a first switchback provided between the first and second positions; a second switchback provided between the second and first positions; a first gate at a branching point of the first switchback; a second gate at a branching point of the second switchback; a sheet exit; a third gate provided at a branching point of the sheet exit; and a controller, which controls such that: the original document is transported through two switchbacks, both face images are read by the two reading sensors; and in another mode, the original document is transported through one of the two switchback sections, and both face images are read by one of the two reading sensors.

Abstract: An auto document feeder which loads and feeds a document to a read position provided on a read surface of a reader, the auto document feeder including a conveying device having an upstream roller placed upstream of the read position and a downstream roller placed downstream of the read position, the conveying device conveying the loaded document through the read position, a stabilizing roller provided upstream of the read position and opposing to the read surface, the stabilizing roller stabilizing movement of the document conveyed by the conveying device, and a guide member provided downstream of the read position and opposing to the read surface, the guide member guiding the document conveyed by the conveying device, wherein the following relationship is established the thickness of the document<a gap between the read surface and the stabilizing roller<a gap between the read surface and the guide member.

Abstract: A sheet size detecting apparatus having a first arm moved by a moving sheet contacting therewith, a second arm moved by the moving sheet contacting therewith, the second arm being disposed at a location differing from that of the first arm in a direction orthogonal to the movement direction of the sheet, and a sensor, wherein the output level of the sensor when only one of the first arm and the second arm has been moved is the same as the output level thereof when neither of the first arm and the second arm is moved, and the output level of the sensor when both of the first arm and the second arm have been moved differs from the output level thereof when neither of the first arm and the second arm is not moved. Thereby, the cost can be suppressed and yet, the wrong detection of the sheet size can be prevented.

Abstract: An opening detector detects a state of a platen whether the platen is “opened” at a level equal to or above a set opening degree or “closed” at a level less than the set opening degree. A reading controller starts lighting of an illumination lamp in response to a change of the state of the platen from the “opened” to the “closed”. A rising detector detects a rising of light intensity of the illumination lamp. A size detector reads an image signal of an imaging element after the rising detector detects a rising of the light intensity, determines presence of a document in a main scanning direction, and decides a document size in the main scanning direction.

Abstract: An image reading apparatus comprises a conveyance rotating body for conveying an original document, an image reading sensor for reading an image of the original document being conveyed by the conveyance rotating body, and a plate-like member for pressing the original document being conveyed by the conveyance rotating body against an image reading surface of the image reading sensor, wherein the plate-like member is curved such that the central part thereof as viewed in the direction orthogonal to the conveying direction of the original document first comes in contact with the image reading sensor.

Abstract: A scan method includes providing a scanner, including an image sensor, a reference pattern and a transmission mechanism. The image sensor scans the reference pattern to generate reference data. The transmission mechanism transmits at least one recording media between the reference pattern and the image sensor. Finally, the image sensor generates scan data, and the scanner compares the scan data with the reference data to obtain a transmission condition thereof.

Abstract: A document feeder includes a feed tray, a catch tray, a carrying path extending from the feed tray to the catch tray via a scanning position, a reversal path diverging from a point on the carrying path downstream relative to the scanning position and connecting to a point on the carrying path upstream relative to the scanning position, a switchback mechanism conveying a sheet back to front from the reversal path toward the scanning point, an ejection mode switching mechanism having a flap provided upstream relative to the catch tray movably relative to an ejection roller, the ejection mode switching mechanism switching an ejection mode by moving the flap between a first mode to eject the sheets on already-ejected sheets and a second mode to insert the sheets under already-ejected sheets. The flap forms part of the reversal path in the first mode.

Abstract: A sheet conveying device of an aspect of the invention includes: a conveying path that allows a sheet to be conveyed and includes a first guide face and a second guide face opposing and apart from each other at a predetermined interval; a sheet conveying unit disposed on the conveying path; and a first detecting unit and a second detecting unit arranged opposing each other across the conveying path. Each of the first and second detecting unit includes: an arm member rotatably supported to take a posture where the arm member projected from the guide face to the conveying path and a posture where the arm member is retracted from the conveying path by rotating toward the guide face; and a first sensor that outputs a signal depending on the posture of the arm member.

Abstract: An image reading apparatus includes a first reading part which reads a first side of a document, a second reading part located on a document discharge path which reads a second side of the document with an image sensor, a path narrowing member positioned across from the image sensor on the document discharge path; and an adjusting unit, wherein the adjusting unit adjustably moves the path narrowing member closer to and farther away from the image sensor in order to correspondingly move the document closer to and farther away from the image sensor. The image reading apparatus is capable of increasing reading speed when a one-side reading of a document is performed as well as minimizing any damage done to data produced by the reading when a double-side reading of a document is performed.

Abstract: The present invention comprises a light volume detection means for detecting the light volume according to the deviation amount at a sheet transfer position in the width direction of a sheet end to be transferred, the light volume detection mean being constituted by a light emitting element and a light receiving element having a light receiving surface of a prescribed length in the width direction of the sheet, and at least either said light receiving element or the light emitting element can be moved to a position in the sheet width direction according to the size of the sheet placed on the feed tray. Therefore, even if the size of the sheet transferred by the transfer means is different, the light volume detection means is able to detect the light volume at an adequate position according to the size of the sheet, the detection accuracy of the position deviation amount is enhanced with respect to the sheet different in size, and the accurate deviation amount can be detected.