Abstract: An image reading unit includes an image reading section that reads an image of a document in a one-dimensional direction by one-dimensionally aligned imaging elements, a light source that irradiates an image reading region by the image reading section with light, and a rotation head that holds the image reading section and the light source in a manner that the image reading section and the light source are rotatable relative to the document about a rotation axis which is parallel to an alignment direction of the imaging elements.

Abstract: An image reading apparatus comprises a moving unit on which a reading unit is mounted and which slides on a guide, and a driving unit mounted on the moving unit and includes a pinion gear meshing with a rack which extends in a scanning direction and is disposed between the pinion gear and the guide. A slide contact portion between the guide and the moving unit includes a first slide contact portion on the rack side and a second slide contact portion. The first slide contact portion includes a first surface being inclined so as to displace the moving unit toward the rack. The second slide contact portion includes a second surface preventing the moving unit from being displaced toward the rack.

Abstract: A first feeder contacts a first surface of a first sheet held in a first tray and feeds the first sheet toward a recording unit. A second feeder contacts a first surface of a second sheet held in a second tray and feeds the second sheet toward the recording unit. An inner member is disposed above a standing plate. An outer member comprises an upstream portion opposing the standing plate, and a downstream portion opposing the inner member. The inner member guides the first surface of the first sheet and the first surface of the second sheet. The standing plate guides the first surface of the second sheet. The upstream portion of the outer member guides a second surface of the second sheet, and the downstream portion guides a second surface of the first sheet and the second surface of the second sheet. The standing plate moves relative to the outer member.

Abstract: An image reader is provided, which includes a housing, a document table, a reading unit disposed between the housing and the document table and configured to read an image of a document sheet on the document table, and a carriage configured to hold the reading unit and move along a moving direction, the carriage including a protruding portion formed to protrude toward the reading unit, on a bottom surface of the carriage that faces a lower surface of the reading unit.

Abstract: An image reader is provided, which includes a housing including a base, and a reading unit including a holder, the base including a bottom wall, a first guide disposed at a first-side portion of the bottom wall in a first direction, and a second guide disposed at a second-side portion of the bottom wall in the first direction, and the reading unit further including a third guide disposed at a first-side portion of the holder in the first direction, the third guide configured to come into sliding contact with the first guide when the reading unit moves, and a fourth guide disposed at a second-side portion of the holder in the first direction, the fourth guide configured to come into sliding contact with the second guide when the reading unit moves.

Abstract: A recording apparatus includes a recording processing unit that crosses a supporting stage; and a Y axis movement unit that causes the recording processing unit to move. The Y axis movement unit includes a guide rail of a reference side and a guide rail of a following side that support the recording processing unit to be free sliding; a first rail attachment base, which is fixed to the supporting stage, and to which the guide rail of the reference side is attached; and a second rail attachment base, which is fixed to the supporting stage, and to which the guide rail of the following side is attached. The first rail attachment base includes an attachment reference portion, and the load that the first rail attachment base receives from the recording processing unit is greater than that received by the second rail attachment base.

Abstract: An image forming apparatus includes an automatic document feeder to feed an original document downstream, a frame, an image reader to read the original document fed by the automatic document feeder, and an image reader mounting unit to hold the image reader thereon. The frame pivotally supports the image reader mounting unit. A parallelism adjusting unit is provided to adjust parallelism of the image reader mounting unit. The parallelism adjusting unit is disposed on a side opposite a pivoting center for the image reader mounting unit at a prescribed interval therefrom. The pivoting center is located near a reading reference point in the image reader, at which the image reader starts reading the original document in main and sub-scanning directions.

Abstract: An image reading apparatus comprises a reading unit including a movable sensor, a first reading mechanism which moves the reading unit to read an original placed on a platen, a second reading mechanism which conveys the original relative to the reading unit to read the original, a common driving source which drives the first reading mechanism and the second reading mechanism, a transfer unit which transfers a driving force from the driving source to the first reading mechanism and the second reading mechanism, and a switching unit which switches rotation used to drive the second reading mechanism to one of forward rotation and reverse rotation with respect to rotation of the driving source in one direction, the switching unit operating as the reading unit moves.

Abstract: An image reading unit configured to rotate and read a front and a back of a document may deviate from an original reading position due to aged deterioration or an external physical impact and become incapable of reading an image accurately. An image processing apparatus rotates an image reading unit including a sensor in units of predetermined angles to read a white reference member, acquires luminance information about the white reference member at the respective predetermined angles of rotation, determines an angle at which the luminance information is greater than other pieces of the luminance information among a plurality of pieces of the acquired luminance information at the respective predetermined angles, and rotates the image reading unit based on the determined angle to correct a reference position of the image reading unit.

Abstract: An image reading apparatus includes a reading unit, a conveyance unit, a carriage, a motor, a motor gear, a conveyance gear, a carriage gear, a switching gear, and a control device. The conveyance unit is configured to convey a document from a document tray. The switching gear is configured to be placed in either one of a first position where the motor gear is communicated with the conveyance gear and a second position where the motor gear is communicated with the carriage gear. The control device is configured to: control the motor to rotate the motor gear in a first direction to have the switching gear free from the conveyance gear in response to a determination that the document jam has occurred; and control the motor to rotate the motor gear in a second direction to have the switching gear communicate with the conveyance gear.

Abstract: An image reading device has a light source section that includes light sources of a plurality of colors and that emits light in one color during a period for reading one line and switches the color of the light source lit cyclically from one line to the next, an image sensor that reads one color per line, a data generation section that generates image data of the light source color which is the color of the light source lit during reading, a memory that stores a plurality of lines' worth of the image data, and a remaining color component generation section that determines the pixel value of a color component other than the light source color based on the pixel values of pixels around a pixel of interest.

Abstract: A scanner for scanning an object having a circumferential surface, the scanner comprising a housing with a glass pane defining an internal area containing camera assembly configured to scan the circumferential surface of the object, and a carriage assembly to rotatably move the object across the glass pane of the scanner in synchronous motion with the movement of the camera assembly.

Abstract: Contamination of a reading window is detected between documents by a contamination detection section when a plurality of sheets of documents are transferred and a transferred document is read through a reading window, transfer of the document is stopped by a stopping section based on the detection result, and a corresponding purport is displayed on a display section.

Abstract: An image scanning device has a sheet conveying roller conveying a sheet when a conveyed sheet scanning function is activated, a guide member defining a sheet feed path, a first gear transmitting a driving force to the sheet conveying roller, a first supporting shaft extending in a direction parallel with a width direction of the sheet feed path and supporting the first gear, a second gear engaging with the first gear, a second supporting shaft extending in a direction perpendicular to the first supporting shaft and supporting the second gear, a holder unit holding the second supporting shaft, the holder unit arranged at one end of the sheet feed path in the width direction, a reinforce member made of metal and extending in the width direction, first and second fixing units fixing longitudinal ends of the reinforce member to the holder unit and the guide member, respectively.

Abstract: A reading unit includes a carriage extending in a first direction, and an image sensor configured to be supported by the carriage, and having a case extending in the first direction and a plurality of light receiving elements contained in the case and arranged in the first direction. The carriage has a reference surface, a pair of supporting portions provided at two end sides in the first direction, and one end edge positioned on one side, with respect to the reference surface, in a second direction orthogonal to the first direction and parallel to the reference surface, and the case has a pair of supported portions provided to correspond to the pair of supporting portions and configured to be supported swingably by the corresponding supporting portions. The case is configured to swing about a first axis between a first position and a second position.

Abstract: A document scanner comprises a first image sensor unit (32) and a second image sensor unit (30) and a scanning mechanism (70, 72, 76, 80) for causing relative movement between a document and the units so that the units scan the document in a scanning direction. The first unit (32) is situated ahead of the second unit (30) in the scanning direction and partially overlaps the second unit.

Abstract: An image processing apparatus, comprising a main body and a movable unit configured to be swingable about a first axis located on a rear side and to move between a first placement position and a first separated position, wherein the main body comprises: side frames; an image processing unit; and a body cover comprising side covers and an upper opening, and wherein: each of the side frames has a flat surface part having a height in a first state on a front side; and each of the side covers has a first part having a height in the first state on the front side, a second part in a second state higher than the first state on a rear side near the first axis, and a third part formed to connect the first part with the second part while changing the height thereof.

Abstract: An optical unit of an image reading device has the center of gravity in a position toward a first sub scanning direction, relative to the middle point of the optical unit in terms of sub scanning directions. An engagement part is provided in a position toward a first main scanning direction relative to a sliding part. A plurality of pairs of pinching parts include a first pair provided in a position toward the first sub scanning direction and a second pair provided in a position toward a second sub scanning direction. Of the two pinching parts in the second pair, the pinching part provided in a position toward the first main scanning direction is biased by a first biasing member toward a rail part side, and the pinching part provided in a position toward a second main scanning direction is not biased by the first biasing member.

Abstract: An image reading apparatus includes an image scanning unit that is provided with a holding portion holding a flexible flat cable. The holding portion is protruded toward an upstream side in a sub scanning direction, and provided with a second wall part. The flexible flat cable that is extended from a connector is brought into contact with the second wall part. As for the flexible flat cable, a downward movement is regulated by a lower holding portion and an upward movement is regulated by an upper holding portion. Accordingly, the flexible flat cable does not rise.

Abstract: A photoelectric conversion element includes: a plurality of light receiving elements that are arranged in a main-scanning direction, are arranged in a sub-scanning direction according to colors of light to be received, and accumulates electric charge due to light exposure; and a plurality of AD conversion units that convert analog signals that indicate quantities of electric charge accumulated in the light receiving elements into digital signals are provide for each of groups each consisting of a predetermined number of pixels corresponding to the light receiving elements arranged in the sub-scanning direction. The AD conversion units convert the analog signals into the digital signals in an order in which the light receiving elements in the group are exposed to light. The light receiving elements constitute a correction unit that performs correction so as to reduce a difference relating to the timings in the sub-scanning direction.

Abstract: An image forming apparatus has a printing section and a document reading section. The printing section prints on paper while transporting it. The document reading section includes a document transport portion which automatically transports, sheet by sheet, a document placed thereon. The document reading section generates image data by reading the document. The document reading section is operable in an ordinary reading mode in which it reads the document at a previously determined ordinary speed and in a quiet reading mode in which it reads the document at a quiet speed lower than the ordinary speed. The document reading section reads the document in the quiet reading mode when the printing section is not printing and in the ordinary reading mode when the printing section is printing.

Abstract: A method of reproducing an original document with a reproduction machine to produce a copied document, comprising the steps of: providing a marking member which contains a marking onto the reproduction machine; opening a cover unit of the reproduction machine; placing the original document on a glass surface of a glass unit of the reproduction machine; closing the cover unit so that the glass surface is covered by the cover unit; and pressing a start button of the reproduction machine to start a scanning process such that the marking and the original document are scanned together in the scanning process and are appeared in the copied document. The marking member is provided on the cover unit or the glass unit so as to make sure that the marking is well-positioned and copied in the copied document.

Abstract: An image reading apparatus that includes an image reading portion, a tray, a first regulation member movable in a width direction on the tray, a second regulation member movable in association with the first regulation member, a first rotating portion and a second rotating portion that are each capable of being rotated by a sheet on the tray, and a sensor portion configured to generate a signal based on rotations of the first and second rotating portions. The first rotating portion is located between the first regulation member and the second regulation member that regulate both edges of a sheet having a minimum width, and the second rotating portion is located between the other edge of a sheet having a smaller width and the first regulation member, when sheets having different widths are supported on the tray with each having one edge aligned with the first regulation member.

Abstract: There is a problem in that, when a handle section is provided in a recording device, the handle section protrudes from a casing and the size of the recording apparatus is increased. A recording apparatus is provided with a recording head which records on paper and a discharge tray which is provided to be able to slide with regard to a casing and holds the paper which is recorded upon using the recording head and discharged, where the discharge tray has a through section which is formed on the downstream side in a discharge direction and a handle section which is formed at an edge section more to the downstream side in the discharge direction than the through section, the handle section is accommodated inside of the casing in a state where the discharge tray is accommodated in the casing, the through section and the handle section are positioned outside of the casing in a state where the discharge tray is drawn out from the casing, and the discharge tray is supported in a state of hanging down from the casing.

Abstract: An image reading device includes a conveyor unit that conveys a document along a conveying path for ADF-type image scanning including a curved path. The conveyor unit includes a conveyor roller that reverses a conveying direction of the document in the curved path. The device further includes a first contact surface that comes into contact with a first side of the document when the document is conveyed, a second contact surface that comes into contact with a second side of the document when the document is conveyed, a first reading unit that reads an image on the first side of the document, and a second reading unit disposed above the second contact surface and reading an image on the second side of the document. A part of the conveyor roller is disposed lower than the first and second contact surfaces in an up down direction of the image reading device.

Abstract: A light collecting member includes a lens to make incident light be collected on a light receiving member, a lens barrel to house the lens, an end portion into which a light enters of the lens barrel being arranged near the light receiving member and a fence member to cover the end portion into which a light enters of the lens barrel and the light receiving member, the fence member having an exhaust port formed in a manner extending in a vertical direction.

Abstract: An image reading apparatus includes a stacking unit on which a document to be fed is stacked, a sensor configured to output a signal indicating that the document has been stacked on the stacking unit, a discharging unit to which the document is to be discharged, wherein the discharging unit includes a lamp, and a control unit configured to turn on the lamp in response to the signal indicating that the document has been stacked on the stacking unit output from the sensor.

Abstract: Since a light emitting surface in a cross section perpendicular to the longitudinal direction of a light guide is formed to have a smaller width than a reflecting surface, light of an LED, which is incident from an end surface of the light guide and is scattered throughout the entirety of the longitudinal direction in the reflecting surface, is condensed toward the light emitting surface, and is then emitted in the form of a band toward a document from the light emitting surface. Therefore, it is possible to provide a CIS module including an illumination unit having a new configuration capable of illuminating a portion where the document and an optical axis of the lens array included in the lens unit intersect, in the form of a band with high efficiency using the illumination unit.

Abstract: A document reading device includes: a document reading device main body; and an opening/closing body with one end supported rotatably with respect to the document reading device main body while another end openably/closably provided, the other end of the opening/closing body being provided with a handgrip having a depression sloped toward inside of the opening/closing body in accordance with approach of the opening/closing body to the document reading device main body in a closed status with respect to the document reading device main body.

Abstract: An image scanning device includes a bottom wall, a surrounding wall extending upwardly from the bottom wall, a frame connected to the surrounding wall and having a first side plate, and a transparent panel fixed to the frame and having a lateral side supported by an upper part of the first side plate. A contact image sensor module is disposed on the bottom wall transverse to the first side plate, and includes a housing having a first short side wall spaced apart from the first side plate by a first distance less than or equal to 2 mm, and a plurality of sensors, one of which that is closest to the first short side wall is spaced apart from an outer surface of the first short side wall by a second distance less than or equal to 2.5 mm.

Abstract: A recording apparatus includes a recording unit that performs a recording operation on a medium, a discharge unit that discharges the medium that has undergone the recording operation by the recording unit, a medium receiving tray that receives the medium discharged from the discharge unit, the medium receiving tray being shiftable between a first state in which the medium receiving tray is drawn out in a medium discharge direction and a second state in which the medium receiving tray is retracted in a direction opposite to the medium discharge direction, and a blocking mechanism configured to be engaged with the trailing edge of the medium while the medium receiving tray is shifted from the first state to the second state, and to restrict the medium from being drawn inside.

Abstract: An optical scanning apparatus, including: a light source unit; a deflection unit; an incident optical system; and an imaging optical system, wherein at least one optical surface of a plurality of imaging lenses included in an imaging optical system has a non-circular shape in a sub-scanning section perpendicular to a main scanning direction, and a non-circular amount of the non-circular shape changes along the main scanning direction, and wherein the followings are satisfied: ds(Y=0)<0; and ds(Y=Ymax)>0, where ds(Y=0) and ds(Y=Ymax) respectively represent a paraxial field curvature at a center position in a sub-scanning direction perpendicular to the main scanning direction and a paraxial field curvature in the sub-scanning direction at a maximum image height in an effective scanning range of the surface to be scanned by the beam from the light source unit in the main scanning direction, among field curvatures at a center position in the effective scanning range.

Abstract: An image scanner includes a stationary original plate on which a stationary original is placed and a moving original plate, over which a moving original is conveyed, aligned with the stationary original plate in a sub-scanning direction and tilted relative to the stationary original plate by a given angle. A reader is movable in the sub-scanning direction between a stationary original reading span disposed opposite the stationary original via the stationary original plate to read an image on the stationary original and a moving original reading position disposed opposite the moving original via the moving original plate to read an image on the moving original. The reader pressingly contacts the stationary original plate and the moving original plate as the reader moves in the sub-scanning direction.

Abstract: An image capture system including a platen for receiving a media sheet bearing an image to be captured; an illumination system for illuminating the media sheet; a mirror disposed in optical communication with the platen, for reflecting light from the illumination system reflected from the media sheet; and an optical sensor for receiving the light reflected by the mirror. The interrelationship between the platen, mirror and optical sensor is such that a location of a top edge of the mirror's primary reflection projected onto the platen is lower than a location of a bottom edge of the image's secondary reflection projected onto the platen. In this way, the image captured by the optical sensor is free of secondary reflections.

Abstract: A scanner is disclosed. The scanner has a platen with at least one edge of the platen uncovered.

Abstract: An image reading apparatus according to the invention includes a transparent member on which an original document is placed, a reading unit arranged below the transparent member, the reading unit being movable reciprocally in a reading direction of the original document, a spacer member arranged at the reading unit for maintaining a prescribed interval between the transparent member and the reading unit by contacting to the transparent member, and an electrostatic removing member arranged at a position close to the spacer member when the reading unit is positioned at a prescribed position.

Abstract: An image reading apparatus according to one aspect of the present disclosure includes a document sheet table, a first carriage, a photoelectric converting portion, and a position detecting portion. First carriage has lighting portion. Position detecting portion detects initial position in reciprocating of first carriage. Lighting portion includes: light guide member on which the light from light source is incident, and which guides incident light in primary scanning direction and applies the light to document sheet table; and heat dissipating member that dissipates heat generated in light source. Position detecting portion includes: light emitter that emits light; light receiver that receives light emitted from light emitter; and detection member that moves in secondary scanning direction along with reciprocating of first carriage, in order to detect initial position of first carriage.

Abstract: A sheet feeding device includes a sheet supporting portion, a sheet feeding portion, and a movable regulating portion. The sheet feeding portion feeds a sheet bundle uppermost sheet. The movable regulating portion is disposed downstream of the sheet bundle in a sheet feeding direction such that the movable regulating portion is tiltable between a regulation position and a regulation release position. While the movable regulating portion regulates the sheet bundle movement in the regulation position, the sheet feeding portion forms a loop in the uppermost sheet between the sheet feeding portion and the movable regulating portion, the movable regulating portion is moved to the regulation release position after loop formation to remove the formed loop, and the movable regulating portion is returned to the regulation position after loop removal such that the movable regulating portion raises the uppermost sheet leading end to separate the uppermost sheet from other sheets.

Abstract: A document reading device includes a reading table, an openable member, a detection member, an open and close movement member, a reading member, a reading movement member, and a controller. The reading table, which allows a document to be placed thereon, is covered or uncovered by closing or opening the openable member. The open and close movement member is moved as the openable member is opened or closed. The open and close movement member positioned at the detection position is detected by the detection member. The reading member reads the document on the reading table while being moved by a drive force controlled by the controller. The reading movement member is moved as the reading member is moved. The reading movement member positioned at the detection position is detected by the detection member.

Abstract: An image reading apparatus includes an original document platform, a reflection carriage, a wire, a pulley, a slide member, a projecting section and a guide section. The reflection carriage includes a mirror for reflecting light, and is moved in a first direction along a sub-scanning direction with respect to the original document. The wire is wound around a pulley. The slide member is installed on the reflection carriage, rotatably supports the pulley, and slidably moves in the first direction with respect to the reflection carriage. The projecting section is provided to project in a second direction that intersects with the first direction, on one of the reflection carriage and the slide member. The guide section is provided to extend in the first direction on the other of the reflection carriage and the slide member. The projecting section abuts against the guide section.

Abstract: There is provided an image reading device comprising: a image capturing unit that captures a manuscript; a predetermined image pattern displayed in a region that is captured by the image capturing unit and provides a background of the manuscript; and a region determination unit that determines an image region corresponding to the manuscript, based on an image element corresponding to the image pattern and another image element corresponding to a shadow of the manuscript in an image captured by the image capturing unit.

Abstract: An image reading apparatus includes: a contact glass provided at an upper surface of a main body of the apparatus to set a manuscript thereon, an image sensor being positioned below the contact glass and having a reading surface on contact glass side for reading an image from the manuscript on the contact glass, a carriage supporting the image sensor accommodated in a sensor container formed to have a recess open to the contact glass side, a rail member slidably supporting the carriage, and a biasing member biasing the image sensor to the contact glass side via a biased portion adjacent to the reading surface of the image sensor. An upper end of the biasing member is positioned below the contact glass and above the lower surface of the image sensor.

Abstract: A sheet scanner comprises a sheet inlet on a front side, a scanned sheet outlet on a rear side, and a deflector to direct scanned sheets from the outlet towards the front side of the scanner, over the top cover thereof, and further comprises a stopper on the top cover, at the front side of the scanner and above the sheet inlet, to temporarily restrain the leading edge of a scanned sheet such that the sheet advances and folds over itself and beyond the stopper, the leading edge being released from the stopper when the sheet folded over itself and beyond the stopper pulls it downwards.

Abstract: In an image reading device, a scanning unit moves relative to the main unit between a base position and a moved position. A conveyance unit moves relative to the scanning unit between a base position and a moved position at which the cover closes the platen, and is formed with a first and second openings. The cover member moves between a base position at which the cover member covers a second opening and a moved position. The first and second detectors detect a state of the scanning unit, the conveyance unit, and the cover member. The conveyance unit conveys the document along one of a first and second conveying paths that is used to convey the document and is determined based on the state of the first and second detectors.

Abstract: Provided is a light guide, in which: at least one of a reflecting part or a light exit part has a light condensing action in a direction intersecting a predetermined direction; the at least one of the reflecting part or the light exit part includes diffusing parts arranged in the predetermined direction; the diffusing parts include: a first curved surface having a first degree of diffusion in the predetermined direction for a sparse region of light sources; and a second curved surface having a second degree of diffusion, which is lower than the first degree of diffusion, in the predetermined direction for a dense region of the light sources; and each of the first curved surface and the second curved surface has a shape corresponding to a part of a cylinder extending in a direction orthogonal to the predetermined direction in which the light sources are arrayed.

Abstract: An image forming apparatus includes: a housing accommodating an image forming unit and includes a side wall and an opening to feed the sheet from an outside to the image forming unit; a feeding tray moving between a holding position and an accommodation position; a guide provided at the feeding tray, the guide being configured to abut against the sheet which is held on the feeding tray from a rear end side of the sheet in a feeding direction along with the sheet is fed to the image forming unit and define a holding position of the sheet when the feeding tray is arranged at the holding position and the sheet is placed on the feeding tray; and a recess part formed on the sidewall of the housing and configured to accommodate the guide therein when the feeding tray is arranged at the accommodation position.

Abstract: There is provided a method for properly placing a document on a reference position of a document positioning plate. The method for controlling an image reading apparatus for reading a document placed on a document positioning plate includes acquiring an image of an image-readable region including the document positioning plate; detecting a document to be read in a vicinity of a reference position for reading the document which is placed on the document positioning plate, and controlling a display unit to display an image of a first region of the document positioning plate in a case where the document is not detected, and controlling the display unit to display an image of a second region in the vicinity of the reference position in a magnification that is greater than a magnification for displaying the image of the first region in a case where the document is detected.

Abstract: A scanner device including: a scanning path on which a scanning member for scanning an image from a document is disposed; a supply path on which a document is supplied to the scanning path; a discharge path on which a document is discharged after scanning of the document on the scanning path has been completed; and a re-supply path that extended to the supply path from a intersection where the scanning path and the discharge path cross so that a document fed along the discharge path in a direction opposite to a document-feeding direction is re-supplied to the supply path after scanning of one side of the document has been completed, wherein one-side guide portions of the supply path, the discharge path, and the re-supply path are integrally formed.

Abstract: An image scanner includes a stationary original plate on which a stationary original is placed and a moving original plate, over which a moving original is conveyed, aligned with the stationary original plate in a sub-scanning direction and tilted relative to the stationary original plate by a given angle. A reader is movable in the sub-scanning direction between a stationary original reading span disposed opposite the stationary original via the stationary original plate to read an image on the stationary original and a moving original reading position disposed opposite the moving original via the moving original plate to read an image on the moving original. The reader pressingly contacts the stationary original plate and the moving original plate as the reader moves in the sub-scanning direction.

Abstract: A document size detector sets an amount of light to be emitted from a light source for document size detection in accordance with the amount of disturbance light detected by the CCD, switches on the light source so as to make the light source emit the set amount of light, and detects the size of a document placed on a platen. Therefore, erroneous detection of a document size is prevented and glare that a user is subjected to when the size of a document placed on the platen is detected is reduced.