JP2014045391A - Image reading device, and image forming apparatus - Google Patents

Abstract

An object of the present invention is to eliminate an unnecessary image from an image of a document in which an unnecessary image such as a shadow of a binding portion is easily formed, such as a book.
Scales 101 and 102 for positioning a document are provided on a contact glass 35 used when reading a book document. The scale 101 in the front-rear direction includes a white reference plate 105 on the side facing the contact glass 35. The value of the image data corrected by the data read from the white reference plate 105 is determined by the density of the white reference plate 105. Therefore, when the white reference plate 105 is partially contaminated, the reflectance is low. Since the image data of the portion corresponding to the dirty portion becomes whitish on the contrary, the white reference plate 105 originally needs to have a uniform density. Therefore, the movable reference plate 110 is provided in addition to the white reference plate 105. The movable density reference plate 110 is disposed between the white reference plate 105 and the light source 37. By using this, a part of the white reference plate 105 is made to have a different density and the image corresponding to the position is made white.
[Selection] Figure 6

Description

  The present invention relates to an image reading apparatus capable of reading a spread original document such as a book, and an image forming apparatus including the image reading apparatus.

  When an image is acquired on the platen with a double-page spread document such as a book, the spread document is separated from the platen at the binding portion, so the light from the light source for illuminating the document surface is sufficient. The image does not reach the surface and the image to be acquired becomes dark. For this reason, image information is acquired even though there is no information to be acquired as an image in the binding portion of the spread original, and if that image is developed, the toner is consumed wastefully. In addition, if a double-page spread document is pressed with a strong force in order to make the binding portion inconspicuous, the image may be distorted due to the deformation of the glass on the document table.

  In the invention disclosed in Patent Document 1, pre-scan is performed to grasp the document density and the image density is corrected. In this case, a pre-scan operation is necessary and workability is poor. In the invention disclosed in Patent Document 2, the pre-scanned image is displayed on the image display unit to set the outer frame deletion. The binding part cannot be erased, but it can also be applied to erase the binding part. However, pre-scanning is necessary, workability is poor, and a display unit capable of displaying an image is required, which increases the size of the apparatus. Furthermore, in the invention disclosed in Patent Document 3, only one half of a spread original can be copied at a time.

  Conventionally, an apparatus having an image editing function for a read image can be erased by designating a position to be erased, but the work of designating the position has been troublesome. For example, when the position to be erased is input numerically from the operation panel, it is necessary to measure the position.

  In addition, although there is an apparatus having a mode for automatically erasing the central portion of the paper size, there are many cases where the document does not necessarily match the paper size, and there is a problem that the erasing position is shifted.

  Therefore, when a spread document such as a book having a binding portion is a document, it is very troublesome to obtain a copy by erasing an image such as a shadow of the binding portion, and a solution has been desired.

  The present invention has been made in view of the above problems, and eliminates unnecessary images from an image of a document in which an unnecessary image such as a shadow is easily formed like a binding portion in a double-page spread document such as a book. It is an object of the present invention to reduce wasteful toner consumption and to obtain an image that is easy to see without forcibly pressing the document.

  The image reading and mounting according to the present invention includes a transparent document table, a light source that irradiates light on the document placed on the document table through the document table, a white reference plate that corrects illuminance unevenness of light emitted from the light source, The original scale indicating the set position of the original placed on the original table, and the original by receiving light reflected from the original placed on the original table and the white reference plate by the light emitted from the light source. And an image sensor that scans the white reference plate, and an image output unit that outputs image data of the scanned document, a movable density reference plate having a reflectance different from that of the white reference plate, and a position of the movable density reference plate And a moving means for moving the movable density reference plate along the longitudinal direction of the document scale.

  According to the present invention, it is possible to easily specify a part where an image is to be erased or a part which is desired to be whitish while a spread document such as a book is actually placed on a document table, and a pre-scan operation is not required. This eliminates the need for complicated processing and procedures.

1 is a schematic configuration diagram illustrating an example of a copying machine as an image forming apparatus that is an object of the present invention. The figure which shows the state which set the book manuscript in the spread on the contact glass which is the manuscript table The figure which shows sectional drawing of the principal part of Embodiment 1 of this invention. Exploded view showing a cross-sectional view of the main part of the present embodiment Perspective view of movable density reference plate Plan view showing the contact glass and components attached to it, as seen from above The top view which shows the state which has arrange | positioned the movable density reference plate outside the reading area The figure which shows the operation | movement of the shading correction | amendment of Embodiment 1. The top view which shows Embodiment 2 of this invention The top view which shows the state which has arrange | positioned the movable density reference plate outside the reading area The figure which shows the operation | movement of the shading correction of Embodiment 2. The perspective view which shows the movable concentration reference | standard board of Embodiment 2 of this invention. The figure which shows the operation | movement of the shading correction of Embodiment 3. The figure which shows the white reference | standard data acquisition area of Embodiment 4 of this invention The figure which shows the other example of the white reference | standard data acquisition area of Embodiment 4 of this invention. FIG. 10 is a flowchart showing an operation of shading correction according to the fourth embodiment. The figure which shows the white reference | standard data acquisition area of Embodiment 5 of this invention. The figure which shows the other example of the white reference | standard data acquisition area of Embodiment 4 of this invention. FIG. 10 is a flowchart showing an operation of shading correction according to the fourth embodiment.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
The present embodiment will be described by taking an example of an image forming apparatus such as a copying machine, a printer, a facsimile, and a multifunction machine of these, but the present invention is not limited to the illustrated embodiment.

<Embodiment 1>
In FIG. 1, a copying machine 11 as an image forming apparatus fixes an image forming means 12 for forming a toner image on a recording medium and a toner image on the recording medium formed by the image forming means 12 to the recording medium. A fixing device 13, a recording medium conveying device 14 for feeding a recording medium to the image forming means 12, a first apparatus main body 15 accommodating the image forming means 12, the fixing device 13 and the recording medium conveying device 14, and a document. An image reading unit 16 that reads an image, a second apparatus main body 17 that accommodates the image reading unit 16, and an automatic document feeder (hereinafter simply referred to as ADF) 18 having a pressure plate function as an opening / closing member that transports a document. Although not shown, the ADF 18 is mounted on the second device main body 17 so as to be openable and closable via a hinge mechanism.

  The ADF 18 is provided between a document placing table 20 on which a document bundle can be placed, a contact position that contacts the upper surface of the document bundle placed on the document placing table 20 and feeds the document bundle, and a separation position that is separated from the document bundle. A pickup roller 21 that is moved by the pickup roller 21, a sheet feeding belt 22 that separates documents one by one from a bundle of documents sent out by the pickup roller 21, and conveys them toward a slit glass 36 that is a reading position. A document conveying means 25 comprising 24 and a document discharging means 29 comprising a conveying roller pair 27 and a paper discharge roller pair 28 for discharging the document, which has been read at the reading position, to the document discharging table 26 are provided.

  The paper discharge roller pair 28 includes a drive roller 28a, a driven roller 28b and a driven roller 28c that are in sliding contact with the drive roller 28a, and a switching claw 30 is provided in the vicinity of the paper discharge roller pair 28. The switching claw 30 moves between the first switching position and the second switching position. When the switching claw 30 is switched to the first switching position, the driving claw 30 is driven by the driving roller 28a and the driven roller 28b. The document is discharged to the document discharge table 26.

  When the switching claw 30 is switched to the second switching position, the document is conveyed to the switchback path 31 by the driving roller 28a and the driven roller 28c. The switchback passage 31 is provided with a pair of switchback rollers 32 that can freely rotate in the forward and reverse directions. The document conveyed to the switchback passage 31 is conveyed rightward in FIG. When the switchback roller pair 32 is driven in reverse, the switchback roller pair 32 is transported to the transport roller pair 24 via the re-transport path. For this reason, the document is reversed and conveyed to the reading position.

  As is known per se, the image reading means 16 includes a second device main body 17 that houses the optical system 34, and a contact glass 35 and a slit glass 36 that are fixedly arranged on the upper portion of the second device main body 17. ing.

  In the image reading unit 16, a document including a closed document or a book is placed on the contact glass 35, and the document can be read by pressing the document with the ADF 18. A document automatically conveyed by the ADF 18 is read at the reading position of the slit glass 36. That is, the optical system 34 as an image reading unit includes a first traveling body 39 having a light source 37 and a first mirror 38, a second traveling body 42 having a second mirror 40 and a third mirror 41, and an imaging lens. 43 and a CCD image sensor 44, and the first traveling body 39 and the second traveling body 42 move rightward from the position shown in FIG. Is reflected on the first mirror 38, the second mirror 40, and the third mirror 41 in this order, and then enters the CCD image sensor 44 through the imaging lens 43. In this way, the original image is formed on the CCD image sensor 44, whereby the original image is read.

  When the original is read by the ADF 18, the original traveling in the above-described procedure is read with the first traveling body 39 and the second traveling body 42 fixed to the position shown on the right side in FIG.

  The image forming means 12 includes a first image carrier 45Y, a second image carrier 45C, a third image carrier 45M, and a fourth image carrier 45BK made of a drum-shaped photoconductor. An intermediate transfer belt 46 composed of an endless belt wound around a plurality of support rollers is disposed opposite to the four image carriers 45Y to 45BK.

  The first to fourth image carriers 45Y to 45BK are respectively rotated in the clockwise direction in FIG. 1, and the intermediate transfer belt 46 is rotated in the direction of arrow A in FIG. At this time, the first image carrier 45Y is charged to a predetermined polarity by the charging roller 47.

  The optical writing unit 48 emits a laser beam L that is light-modulated based on the image signal corresponding to the reading result of the original, and the laser is applied to the charging surface of the first image carrier 45Y. By irradiating the beam L, an electrostatic latent image is formed on the first image carrier 45Y, and this electrostatic latent image is visualized as a yellow toner image by the developing device 49.

  When a transfer voltage is applied to the primary transfer roller 50, the toner image formed on the first image carrier 45Y is primarily transferred onto the intermediate transfer belt 46 that rotates in the direction of arrow A in FIG. .

  The transfer residual toner adhering to the first image carrier 45Y after the toner image transfer is removed by the cleaning device 52. In the copying machine 11 of the present embodiment, the first image carrier 45Y, the charging roller 47 disposed around the first image carrier 45Y, the developing device 49, and the cleaning device 52 constitute an integral process cartridge. Yes.

  The developing device 49 has a developing container 53 containing powdered toner, and the electrostatic latent image is visualized by the toner. Further, when the toner amount in the developing container 53 decreases, the toner is supplied to the developing container 53 from the toner bottle 54Y.

  On the other hand, the cleaning device 52 includes a cleaning container 55 that receives the toner removed from the first image carrier 45Y. The toner in the cleaning container 55 is transported to a waste toner container (not shown) by the toner transport device. Is done. Thus, toner is stored in the developing container 53, the toner bottle 54Y, the cleaning container 55, and the waste toner container.

  In the same manner as described above, a cyan toner image, a magenta toner image, and a black toner image are formed on the second image carrier 45C, the third image carrier 45M, and the fourth image carrier 45BK, respectively. Are primarily transferred onto the intermediate transfer belt 46, to which the yellow toner image has been transferred, one after another.

  When the toner amount in the developing container of the developing device for forming the toner image on the second image carrier 45C, the third image carrier 45M, and the fourth image carrier 45BK decreases, the toner bottles 54C, 54M, From 54BK, toner is supplied to each developer container.

  In this manner, the superimposed toner image transferred onto the intermediate transfer belt 46 is secondarily transferred onto the recording medium by the action of the secondary transfer roller 56, and the transfer residual toner attached on the intermediate transfer belt 46 after the transfer. Is removed by the belt cleaning device 52. The cleaning container 55 of the cleaning device 52 also stores toner, and the toner is conveyed to a waste toner container (not shown).

  The recording medium conveyance device 14 is disposed below the intermediate transfer belt 46. The recording medium conveyance device 14 includes a recording medium made of transfer paper, a resin sheet, or the like, or a paper feed cassette 57 that accommodates the bundle S1 and an uppermost cassette. The uppermost recording medium S is provided in a direction indicated by an arrow B in FIG. 1. The uppermost recording medium S includes a paper feed roller 58 that contacts the upper recording medium S and a registration roller pair 59. The sent recording medium S is fed between the intermediate transfer belt 46 and the secondary transfer roller 56 disposed opposite to the intermediate transfer belt 46 at a predetermined timing by the rotation of the registration roller pair 59.

  When the recording medium S passes between the intermediate transfer belt 46 and the secondary transfer roller 56, a transfer voltage is applied to the secondary transfer roller 56, so that the superimposed toner image on the intermediate transfer belt 46 is recorded on the recording medium. Secondary transfer. In this way, a toner image is formed on the recording medium by the image forming means 12.

  The recording medium on which the toner image is formed passes through the fixing device 13, and at this time, the toner image on the recording medium formed by the image forming means 12 is fixed on the recording medium. The recording medium S on which the image is fixed by the fixing device 13 is discharged onto the recording medium discharge stand 61 by the discharge roller pair 60. The recording medium discharge table 61 is formed between the first apparatus main body 15 that stores the image forming means 12 and the second apparatus main body 17 that stores the image reading means 16. In the present embodiment, The in-body discharge type copying machine 11 is configured such that a space between the first apparatus main body 15 and the second apparatus main body 17 on the downstream side in the discharge direction of the recording medium S by the discharge roller pair 60 is opened.

  A switching lever 62 is provided on the upstream side of the paper discharge roller pair 42, and this switching lever 62 is used for the reverse path when copying on the back surface of the recording medium S when copying on the front surface of the recording medium is completed. It can be switched to the 63 side.

  That is, when the trailing edge of the recording medium S is sandwiched between the paper discharge roller pair 60, the paper discharge roller pair 60 is driven to rotate in the reverse direction, and the switching lever 62 is switched to a position communicating with the reverse passage 63. It is conveyed toward the reversing passage 63. A reversing roller pair 64 is provided in the reversing path 63, and the recording medium conveyed through the reversing path 63 by the reversing roller pair 64 is conveyed to the secondary transfer roller 56 side.

  On the other hand, a reflective guide plate 65 is provided on the slit glass 36, and this reflective guide plate 65 constitutes a white reference when reading a document and reflects light from the light source 37.

  A guide member 71 is provided between the contact glass 35 and the slit glass 36, and the guide member 71 scoops up the document that has passed through the slit glass 36 and guides it toward the conveyance roller pair 27. ing.

  FIG. 2 shows a state in which the book document 80 is set on the contact glass 35 in a double-page spread. Since there is a binding portion 81 of the book original 80, light from the light source does not reach sufficiently, and it can be seen that there is a portion X that becomes a shadow and the image becomes black.

  3 to 8 show details of the configuration of the present embodiment. 3 and 4 are sectional views of the main part of this embodiment, and FIG. 4 is an exploded view of the constituent elements. FIG. 5 is a perspective view of the movable density reference plate, and FIG. 6 is a plan view showing the contact glass 35 and the components attached thereto as viewed from above. As shown in the figure, a contact glass 35 used for reading a book document is provided with scales 101 and 102 for document alignment in the front-rear direction and the left-right direction of the apparatus. A symbol Ar in FIG. 6 indicates an image reading area on the contact glass 35.

  The scale 101 in the front-rear direction includes a white reference plate 105 on the side facing the contact glass 35. The white reference plate 105105 is a member having a uniform density equivalent to the white portion of the document, and corrects density unevenness generated by the light source, the light receiving element, and the optical element. This is a technique widely used in image reading apparatuses. In this embodiment, as shown in FIGS. 3 and 12, the white reference plate 105 is bonded to the scale 101, and the scale 101 is bonded to the contact glass 35.

  Since the value of the image data corrected by the data read from the white reference plate 105 is determined by the density of the white reference plate 105, for example, dirt is partially attached to the white reference plate 105 and the reflectance is low. If so, the image data of the portion corresponding to the dirty portion becomes whitish. Therefore, the white reference plate 105 originally needs to have a uniform density, but it is difficult to always keep the white reference plate 105 at a uniform density in an apparatus actually used. In view of this, the present embodiment realizes a function of making parts of the white reference plate 105 have different densities and whitening an image corresponding to the position.

  Therefore, in this embodiment, in addition to the white reference plate 105, a movable density reference plate 110 having a density (for example, whiteness) different from that of the white reference plate 105 is provided. The movable density reference plate 110 is disposed between the white reference plate 105 and the light source 37, but can be disposed at an arbitrary position along the longitudinal direction of the white reference plate 105. The surface of the movable density reference plate 110 facing the light source 37 has a lower reflectance than the white reference plate 105. In other words, it is blackish.

  When such a movable density reference plate 110 is arranged in the image reading range and image reading is performed, image data becomes whitish at a position corresponding to the movable density reference plate 110. When the book document 80 having the binding portion 81 as shown in FIG. 2 is read, if the movable density reference plate 110 is set at the position of the binding portion 81, the portion corresponding to the binding portion 81 of the read image becomes whitish. The shadow of the portion 81 becomes thinner, and unnecessary toner consumption is suppressed.

  As shown in FIG. 4, the movable density reference plate 110 includes a protrusion 110 </ b> B, and can move while being guided by a guide shape portion 120 </ b> A provided on the document guide 120. Further, as shown in FIG. 7, in the case of a normal document having no binding portion, the movable density reference plate 110 does not affect image reading if it is arranged outside the reading area Ar.

  Note that the longitudinal direction of the scale 101 for document alignment, the longitudinal direction of the white reference plate 105, and the moving direction of the movable density reference plate 110 are all sub-scanned for scanning the document placed on the contact glass 35 which is the document table. A document having a larger size can be accommodated by following the direction (the direction orthogonal to the arrow shown as the moving direction (also the main scanning direction) of the movable density reference plate 110 in FIG. 6).

Next, shading correction will be briefly described with reference to FIG.
During the reading operation, image data in the white reference data acquisition region of the white reference plate 105 pasted on the scale 101 is captured prior to image reading. If the data is only one line and the dust is attached to the line, the white reference data is greatly affected. Therefore, the white reference data is usually determined by averaging the data of a plurality of lines. As shown in the figure, when the movable density reference plate 110 is in the white reference data acquisition region, the white reference data of the portion corresponding to the movable density reference plate 110 has a different value from the other regions. The example of FIG. 8 shows a case where the movable density reference plate 110 has an intermediate density (gray). In this case, for example, when a document having the same density as that of the movable density reference plate 110 is read, the image corresponding to the movable density reference plate 110 is white because it is the same as the white reference data. Become. In this way, by setting the movable density reference plate 110 to a state in which the density is higher (the reflectance is lower) than that of the white reference plate 105, it is possible to make the read image data whitish in the corresponding area. .

<Embodiment 2>
A second embodiment is shown in FIGS. FIG. 11 is a diagram showing shading correction in the sub-scanning direction.
In the present embodiment, the movable density reference plate 110 is movable along the horizontal scale 102 of the apparatus. Further, a sub-scanning white reference plate 106 is provided on the side facing the contact glass 35 of the scale 102 in the left-right direction. In the first embodiment, the white reference plate 105 is for correcting unevenness in the direction along the light source 37 (main scanning direction). However, the sub-scanning white reference plate 106 of the present embodiment is moving the light source 37. This is for correcting the temporal light quantity fluctuation. This is called sub-scanning shading and aims to prevent fluctuations in image density during the reading operation when the temporal light quantity fluctuation of the light source 37 is large. This method is often used when a fluorescent lamp or a cold cathode tube is used as the light source.

  Usually, the readable width in the main scanning direction is determined by a sensor such as a CCD used for reading. In order to increase the width, it is necessary to use a sensor having a large number of pixels, which increases the cost. Therefore, it is common to increase the scanning distance in the sub-scanning direction to increase the image reading area. Therefore, the reading area in the sub-scanning direction is usually larger than the main scanning direction. Therefore, when reading a large-size document, the direction in which the size is large coincides with the sub-scanning direction. In the present embodiment, the movable density reference plate 110 can be set in the sub-scanning direction, and if the spread direction of the original document coincides with the sub-scanning direction, the binding portion of the larger original document can be thinned.

  If the movable density reference plate 110 is a normal document having no binding portion, it may affect image reading if it is arranged outside the reading area Ar as shown in FIG. There is no.

<Embodiment 3>
A third embodiment is shown in FIGS.
In the present embodiment, the movable density reference plate 110 has a shape in which the width is continuously different from the direction perpendicular to the movable direction (specifically, a triangular planar shape and the reading area Ar has a peak direction).

FIG. 13 shows the white reference correction operation in this embodiment.
When the average data of the white reference data acquisition region is taken, the white reference data becomes darker at the center of the movable density reference plate 110 as shown in the center of FIG. When an intermediate density original is read, the middle part of the movable density reference plate 110 becomes whitish as shown in the right diagram of FIG. Normally, in the case of an original document with a binding portion, the center of the binding portion is darkest, and gradually becomes whitish as the distance from the center increases. By using the movable density reference plate 110 as in the present embodiment, the binding portion of the original document can be erased more naturally. That is, since the width of the main scanning direction of the original scanning which is orthogonal to the moving direction of the movable density reference plate 110 on the contact glass 35 which is the original table is continuously different, the binding portion 81 of the book original 80 is changed. Can be erased with natural density changes.

<Embodiment 4>
A fourth embodiment is shown in FIGS.
In the present embodiment, the effect range of the movable density reference plate 110 can be changed by changing the white reference data acquisition region. In the example of FIG. 14, the range in which the white reference data becomes dark is narrow, and in the example of FIG. 15, it is wider. The binding portion 81 of the book document 80 takes into consideration the fact that the shadowing range differs depending on the thickness of the book and the binding method.

The operation of this embodiment is shown in FIG.
In the present embodiment, before performing image reading, the operator selects, for example, whether to widen or narrow the binding portion erase width from the operation portion (step S1). Depending on the operator's selection, the white reference data acquisition region is set as the white reference acquisition region 1 in FIG. 14 or the white reference acquisition region 2 in FIG. 15 (steps S2 and S3), and the white reference plate 105 is read. After the white reference data is created (step S4), image reading is performed (step S5).

  That is, in the present embodiment, a computer provided in the image forming apparatus is used as an erasure width selection unit for selecting an erasure width of acquired image data, and a white reference for obtaining image data of the white reference plate 105 according to an operator's selection. Since the data acquisition area can be set, it is possible to cope with the case where the width of the shadowed portion of the binding portion 81 differs depending on the type of the book document 80.

<Embodiment 5>
A fifth embodiment is shown in FIGS.
In the present embodiment, the binding part erasing function is switched ON and OFF by changing the white reference data acquisition area. That is, in FIG. 17, the image density at the position corresponding to the movable density reference plate 110 becomes whitish, but does not change in FIG.

The operation of this embodiment is shown in FIG.
In this embodiment, before performing image reading, the operator selects whether or not to delete the binding portion from the operation portion, for example (step S1). According to the operator's selection, the white reference data acquisition area is determined as the white reference acquisition area 1 in FIG. 17 or the white reference acquisition area 3 in FIG. 18 (steps S2 and S3), and the white reference plate 105 is read. After the white reference data is created (step S4), image reading is performed (step S5). When the binding portion 81 of the book document 80 is to be erased or made whitish, the position to be processed can be easily designated, and there is no need for complicated image processing.

  That is, in this embodiment, since the white reference data acquisition area for obtaining the image data of the white reference plate 105 can be set according to the operator's selection, the shadow of the binding portion can be set with the movable density reference plate 110 set. Settings that do not erase can be easily done.

  The present invention is not limited to the embodiments described above, and many variations are possible by those having ordinary knowledge in the art within the technical idea of the present invention.

11: Copier 12: Image forming means 13: Fixing device 14: Recording medium conveying device 15: First apparatus main body 16: Image reading means 17: Second apparatus main body 20: Document placing table 21: Pickup roller 22: Feeding Paper belt 23: Reverse roller 25: Document conveying means 26: Document discharge table 28a: Drive rollers 28b, 28c: Driven roller 29: Document discharge means 30: Switching claw 31: Switchback passage 34: Optical system 35: Contact glass 36: slit glass 37: light source 38: first mirror 39: first traveling body 40: second mirror 41: third mirror 42: second traveling body 43: imaging lens 44: CCD image sensor 45: image carrier 46 : Intermediate transfer belt 47: Charging roller 48: Optical writing unit 49: Developing device 50: Primary transfer roller 52: Cleanin Device 53: Development container 54: Toner bottle 55: Cleaning container 56: Secondary transfer roller 57: Paper feed cassette 58: Paper feed roller 61: Recording medium discharge table 62: Switching lever 63: Reversing path 65: Reflection guide plate 71 : Guide member 80: book originals 101 and 102: scale 105: white reference plate 106: sub-scanning white reference plate 110: movable density reference plate 110B: projection 120: original guide 120A: guide shape portion Ar: reading area L: laser Beam S: Recording medium

JP 2010-28390 A JP 2009-273030 A JP 2010-68387 A

Claims (6)

A transparent platen,
A light source for irradiating light on the document placed on the document table through the document table;
A white reference plate for correcting illuminance unevenness of irradiation light of the light source;
A document scale indicating a set position of the document placed on the document table;
An image sensor that scans the original and the white reference plate by receiving light reflected from the original placed on the original table and the white reference plate with the light emitted from the light source;
Image output means for outputting image data of the scanned document,
A movable density reference plate having a reflectance different from that of the white reference plate, and an indicator that indicates the position of the movable density reference plate are integrated, and a moving unit that moves the movable density reference plate along the longitudinal direction of the document scale. The
An image reading apparatus comprising: The image reading apparatus according to claim 1.
The longitudinal direction of the original scale, the longitudinal direction of the white reference plate, and the moving direction of the movable density reference plate are all along the sub-scanning direction of the scan of the original placed on the original table. Image reading device. The image reading apparatus according to claim 1 or 2,
The image reading apparatus according to claim 1, wherein the movable density reference plate has a shape in which the width of the original in the main scanning direction of the original, which is orthogonal to the moving direction on the original table, is continuously different. The image reading apparatus according to claim 3.
An erasing width selecting means for selecting an erasing width of the image acquired by the image sensor;
An image reading apparatus characterized in that a white reference data acquisition region for obtaining image data of the white reference plate can be set in accordance with an operator's selection. In the image reading and mounting according to any one of claims 1 to 3,
A partial erasure selection means that allows an operator to select whether or not to erase a part of the image acquired by the image sensor;
An image reading apparatus characterized in that a white reference data acquisition region for obtaining image data of the white reference plate can be set in accordance with an operator's selection. An image forming apparatus using the image reading attachment according to claim 1.