JP5789491B2 - Image reading apparatus and image forming apparatus - Google Patents

Description

  The present invention relates to an image reading apparatus and an image forming apparatus including the image reading apparatus, and more particularly to a technique for correcting shading of an image read from a document.

  2. Description of the Related Art Conventionally, an image reading apparatus reads an image of an original by irradiating light on the original with a light source such as a fluorescent lamp or an LED, and photoelectrically converting reflected light from the original with a photoelectric conversion element and outputting it. It is configured. Further, in such an image reading apparatus, shading correction is performed in order to correct the uneven light distribution by the light source and the sensitivity difference between the photoelectric conversion elements.

  Specifically, as described in Patent Document 1 below, for example, the white reference level value (white reference data) used for shading correction is obtained by photoelectrically converting the reflected light of the white reference plate by turning on the light source. Generated by reading with the element. On the other hand, the value of the black reference level (black reference data) used for shading correction is generated by the reading result by the photoelectric conversion element when the light source is turned off.

JP 2001-51364 A

  However, when reading an image of a document with the light source turned on, for example, there are gaps between a plurality of light guide members provided to guide reflected light from the document to each photoelectric element. As a result, not only the reflected light from the document but also light different from the reflected light may enter each photoelectric element.

  In such a case, when the black reference data used for shading correction is generated by the reading result of the photoelectric conversion element when the light source is turned off using the technique described in Patent Document 1, the photoelectric conversion element The output when the black document is read with the light source turned on and the output when the light source is turned off are greatly different, and there is a possibility that the shading correction cannot be performed with high accuracy.

  Therefore, the present invention has been made in view of such circumstances, and an object thereof is to provide an image reading apparatus and an image forming apparatus capable of performing shading correction with high accuracy.

An image reading apparatus according to the present invention includes a document transport unit that feeds and transports a document one by one, a contact glass on which the document is placed, a light source that irradiates light to the document, and light that is irradiated from the light source. An image reading unit for reading an image to be read, a plate-shaped white reference member attached on the contact glass, and a plate-like member having two surfaces attached on the contact glass, The adhering matter removing member is provided so that the surface comes into contact with the reading surface of the original document being conveyed by the original conveying portion to remove the adhering matter on the original document, and the second surface opposite to the first surface is black. A white reference data acquisition unit that causes the image reading unit to read an image of the white reference member irradiated with light from the light source as a reading target, and acquires the read image as white reference data; A black reference data acquisition unit for causing the image reading unit to read an image of the second surface of the deposit removing member irradiated with light from the light source as a reading target, and acquiring the read image as black reference data; A reading control unit that executes a first reading process that causes the image reading unit to read an image of a document that is being conveyed by the document conveying unit as a reading target, and acquires the read image as document data; and the white reference A shading correction unit that performs shading correction on the document data using data and the black reference data, and the light source extends in the main scanning direction, and two light guides each provided with a light emitting element; Provided outside each of the two light guides, the light emitted from each of the light guides is directed toward the contact glass toward the side between the two light guides. Two light guide white covers, wherein the image reading unit photoelectrically converts received light into a light receiving unit elongated in the main scanning direction, and the light receiving unit reflects light reflected by the reading target. A plurality of light guide members connected by side plates so as to extend in the main scanning direction, and further, the predetermined number of light guide members adjacent to each other. A connecting portion that connects the plurality of predetermined number of light guide members so as to extend in the main scanning direction between the two light guides by bonding a side plate of the optical member using a transparent resin. Configured .

When light is emitted from the light source to the document, for example, not only the reflected light from the document but also light different from the reflected light due to the presence of a connecting part in the light guide path of the image reading unit. It is considered that the image of the document may be read in consideration of this brightness.

However, even in such a case, the black reference data acquisition unit irradiates the second surface of the deposit removal member with light from the light source and actually reflects the reflected light from the second surface, that is, the surface. The black reference data is acquired by receiving light incident from a connecting portion or the like that is different from the reflected light from the light. For this reason, the shading correction | amendment part can perform a shading correction | amendment accurately using the black reference data based on the reflected light actually reflected.

  Also, the adhering material removing member provided so that the first surface comes into contact with the reading surface of the original document being conveyed by the original conveying section and removes the adhering material on the original document is also used as an original document for obtaining black reference data. Yes. For this reason, when performing shading correction, it is possible to omit a space for separately providing an original for obtaining black reference data in the image reading apparatus, or manually placing an additional original for obtaining black reference data manually. It is possible to avoid troubles such as placement.

  Further, the reading control unit causes the image reading unit to read an image of a document by one line in the main scanning direction while moving the light source and the image reading unit in the sub-scanning direction, and acquires the document data. A second reading process can be further executed, and the deposit removing member and the white reference member are read by the reading control unit from a position where reading of an image of a document is started by the second reading process. The reading control unit causes the black reference data acquisition unit to acquire the black reference data before reading the image of the document by the second reading process. At the same time, it is preferable that the white reference data acquisition unit acquire the white reference data before the image of the original is read by the second reading process.

  According to this configuration, when the second reading process is executed, the image of the original is read after the black reference data and the white reference data are acquired without returning the moving direction of the light source and the image reading unit to the opposite side, and shading is efficiently performed. Correction can be performed.

  The image forming apparatus according to the present invention preferably includes the image reading device and an image forming unit that forms an image using data read by the image reading unit.

  According to the present invention, it is possible to provide an image reading apparatus and an image forming apparatus that can perform shading correction with high accuracy.

1 is a schematic cross-sectional view showing a multifunction machine as an example of an image forming apparatus according to the present invention. 1 is a schematic sectional view showing an example of an image reading apparatus according to the present invention. The perspective view which shows an example of the deposit | attachment removal member and white reference | standard member which concern on this invention. The enlarged view which shows an example of the light source and image reading part which concern on this invention. 1 is a block diagram illustrating an example of an electrical configuration of a multifunction machine. 6 is a flowchart illustrating an example of a document reading operation performed by a reading control unit or the like. The expanded sectional view which shows an example of the connection part of an image reading part. (A) is explanatory drawing which shows an example of the image output from CCD when the light source was turned off, (b) is an example of the image which read the 2nd surface of the deposit | attachment removal member with the light source turned on. Explanatory drawing which shows, (c) is an enlarged view of the part read in the connection part vicinity of the image reading part in (b).

  Hereinafter, a multifunction peripheral as an example of an image forming apparatus according to the present invention will be described with reference to the drawings. As shown in FIG. 1, the multifunction device 1 has a plurality of functions such as a copy, a printer, and a scanner, and includes a main body 2 and a stack tray 3 disposed on the left side of the main body 2. , An operation unit 36 for a user to input various operation commands, a document feeder (document transport unit) 5 disposed above the main body 2, and an upper portion of the main body 2. And an image reading device 4.

  The main body 2 includes a plurality of paper feed cassettes 23, a paper feed roller 24 that feeds recording paper from the paper feed cassette 23 one by one and transports it to the image forming section 25, and a recording paper transported from the paper feed cassette 23. And an image forming unit 25 for forming an image.

  The image forming unit 25 forms a toner image on the photosensitive drum 26 and an optical unit 27 that outputs a laser beam or the like based on an image signal acquired by the image reading device 4 described later to expose the photosensitive drum 26. A developing unit 28, a transfer unit 29 for transferring the toner image on the photosensitive drum 26 to the recording paper, a conveyance roller 30 and a roller 31 for heating the recording paper to which the toner image has been transferred and fixing the toner image on the recording paper. And a pair of conveyance rollers 34 and 35 that are provided in the sheet conveyance path in the image forming unit 25 and convey the recording sheet to the stack tray 3 or the discharge tray 33.

  When forming images on both sides of the recording paper, the image forming unit 25 forms an image on one side of the recording paper, and then the recording paper is nipped between the conveyance roller 30 and the roller 31 on the discharge tray 33 side. State. In this state, the conveyance roller 30 is reversed to switch back the recording paper, and the recording paper is sent to the paper conveyance path and conveyed again to the upstream area of the image forming unit 25, and the image forming unit 25 forms an image on the other surface. After that, the recording paper is discharged to the stack tray 3 or the discharge tray 33.

  The operation unit 36 displays a start key 361 for a user to input a print execution instruction, a numeric keypad 362 for inputting the number of copies to be printed, operation guide information for various copying operations, and the like. A display unit 363 including a liquid crystal display having a touch panel function, a reset key 364 for resetting setting contents set on the display unit 363, and a stop key 365 for stopping a printing (image forming) operation being executed. A function switching key 366 for switching between a copy function, a printer function, a scanner function, and a facsimile function.

  As shown in FIG. 2, the document feeder 5 includes a document tray 51, a paper feed roller 52, a transport drum 53, a paper discharge roller 54, and a paper discharge tray 55, and an ADF (Auto Document Feeder). Is configured.

  The document tray 51 is a place where the document is placed. The documents placed on the document tray 51 are taken one by one by the paper feed roller 52 and conveyed to the conveyance drum 53. The document that has passed through the transport drum 53 is discharged to a discharge tray 55 by a discharge roller 54.

  The image reading device 4 optically acquires an image to be read and outputs an image signal. As shown in FIG. 2, the image reading device 4 includes a contact glass 410, a paper dust removing plate (attached matter removing member) 413, a white reference plate (white reference member) 414, light sources 42a and 42b, a carriage 47, and an imaging lens. (Light guide unit in image reading unit) 48 and CCD (Charge Coupled Device, light receiving unit in image reading unit) 49 are provided. The light sources 42 a and 42 b, the imaging lens 48, and the CCD 49 are supported by a carriage 47.

  The contact glass 410 includes a wide document placement glass 412 and a long and narrow document automatic reading glass 411 positioned on the left side of the document placement glass 412 and constitutes a surface on which a document is placed.

  As shown in FIG. 3, the paper dust removing plate 413 is a plate-like member extending in the front-rear direction of the image reading device 4 (the X direction in FIG. 3 and the direction perpendicular to the paper surface in FIG. 2), and automatically reads the original. It is attached on the glass 411 for use. The first surface, which is the surface of the paper dust removing plate 413 on the side of the document feeding device 5 (the upper surface in FIG. 2) is the reading surface of the document conveyed by the document feeding device 5 (the lower surface in FIG. 2). The attachment on the reading surface of the document is removed. Further, the surface opposite to the first surface of the paper dust removing plate 413 (the lower surface in FIG. 2) is black.

  As shown in FIG. 3, the white reference plate 414 is a plate-like member that extends in the front-rear direction of the image reading device 4 (the X direction in FIG. 3 and the direction perpendicular to the paper surface of FIG. 2). Mounted on glass 412. The lower surface of the white reference plate 414 is white.

  As shown in FIG. 4, the light sources 42a and 42b are configured to extend in the front-rear direction of the image reading device 4 (the X direction in FIG. 4 and the direction perpendicular to the paper surface of FIG. 2). For example, a white fluorescent lamp such as a white LED is provided. In other words, the light sources 42 a and 42 b make the light emitted from the white fluorescent lamp into a linear shape extending in the front-rear direction (hereinafter, the main scanning direction) of the image reading device 4, and the main light of the document placed on the contact glass 410. Irradiate one line in the scanning direction.

  As shown in FIG. 4, a plurality of imaging lenses 48 are provided so as to extend in the main scanning direction (X direction in FIG. 4). A plurality of light receiving surfaces of the CCD 49 are provided so as to face each imaging lens 48 at a position below each imaging lens 48 (see FIG. 2).

  In addition, a reading unit RU is configured by a predetermined number of imaging lenses 48 and CCDs 49 connected in the main scanning direction. A plurality of reading units RU are connected by a connecting portion C to constitute a line sensor (image reading portion) having a length corresponding to one line in the main scanning direction. That is, the reflected light received by the plurality of light receiving surfaces of the CCD 49 is photoelectrically converted as an image signal indicating the brightness of each pixel of a plurality of pixels constituting an image for one line in the main scanning direction to be read. , Respectively.

  Note that the configuration of the imaging lens 48 and the CCD 49 is not limited to this. For example, a single reading unit RU having a length corresponding to one line in the main scanning direction, including the imaging lenses 48 corresponding to the number of pixels constituting the image corresponding to one line in the main scanning direction and the light receiving surface of the CCD 49 is provided. The line sensor may be configured only by the one reading unit RU.

  A document image reading method by the image reading device 4 having the above-described configuration includes a flatbed reading mode (second reading process) for reading a document placed on the document placement glass 412, and a document by the document feeding device 5. There are two methods of ADF reading mode (first reading processing) for reading the original when the original passes over the automatic original reading glass 411.

  In the flat bed reading mode, the original placed on the original placement glass 412 is irradiated by the light sources 42 a and 42 b, and the reflected light from the original enters the imaging lens 48. The light incident on the imaging lens 48 is imaged by photoelectric conversion on the light receiving surface of the CCD 49 and output as an image signal. When reading for one line is completed, the carriage 47 is moved in a direction perpendicular to the main scanning direction (sub-scanning direction, Y direction in FIGS. 2 to 4), and the next line is read.

  On the other hand, in the ADF reading mode, when the original conveyed by the original feeder 5 passes through the gap between the automatic original reading glass 411 and the reading guide 59, the automatic original reading glass 411 is emitted by the light sources 42a and 42b. The document is irradiated with light through the. The reflected light from the original enters the imaging lens 48, and the light incident on the imaging lens 48 is imaged by photoelectric conversion on the light receiving surface of the CCD 49 and output as an image signal. When the reading for one line is completed, the document is conveyed by the document feeder 5 and the next line is read.

  Next, the electrical configuration of the multifunction machine 1 will be described with reference to FIG. The multifunction device 1 includes a control unit 10 that controls operation of each unit of the multifunction device 1. The control unit 10 includes a microcomputer including a CPU and a memory such as a ROM and a RAM, for example, and controls the operation of each unit by executing various control programs stored in the memory by the CPU. .

  The control unit 10 is connected to the image forming unit 25, the operation unit 36, the document feeding device 5, and the image reading device 4 so as to communicate with each other.

  For example, the control unit 10 controls the image reading operation by causing the CPU to execute a control program that functions as the reading control unit 11, the white reference data acquisition unit 12, the black reference data acquisition unit 13, and the shading correction unit 14. I do.

  The reading control unit 11 performs control for reading an image of a document placed on the contact glass 410 in the flat bed reading mode and the ADF reading mode. Specifically, in the flatbed reading mode, the reading control unit 11 outputs a driving signal to a motor (not shown) and moves the carriage 47, and outputs a driving signal to the light sources 42a and 42b to place a document. Light is applied to the document placed on the glass 412. Then, the CCD 49 causes the reflected light incident on the light receiving surface via the imaging lens 48 to be photoelectrically converted to output an image signal indicating an image read from the document. Then, the image signal is digitally converted and acquired as document data.

  On the other hand, in the ADF reading mode, the reading control unit 11 drives the document feeding device 5 to convey the documents placed on the document tray 51 one by one, and outputs drive signals to the light sources 42a and 42b. Light is applied to the document passing over the automatic reading glass 411. Then, the CCD 49 causes the reflected light incident on the light receiving surface via the imaging lens 48 to be photoelectrically converted to output an image signal indicating an image read from the document. Then, the image signal is digitally converted and acquired as document data.

  The white reference data acquisition unit 12 outputs a drive signal to a motor (not shown) to move the carriage 47 to the lower part of the white reference plate 414, and then outputs a drive signal to the light sources 42a and 42b. Light is irradiated on the lower white surface. Then, the CCD 49 causes the reflected light incident on the light receiving surface via the imaging lens 48 to be photoelectrically converted to output an image signal indicating an image obtained by reading the white surface below the white reference plate 414. . Then, the image signal is digitally converted and acquired as white reference data.

  The black reference data acquisition unit 13 outputs a drive signal to a motor (not shown) to move the carriage 47 to the lower part of the paper dust removal plate 413, and then outputs a drive signal to the light sources 42a and 42b. Light is applied to the lower black surface of 413. The CCD 49 photoelectrically converts the reflected light incident on the light receiving surface via the imaging lens 48 to output an image signal indicating an image obtained by reading the lower black surface of the paper dust removing plate 413. Let Then, the image signal is digitally converted and obtained as black reference data.

  The shading correction unit 14 uses the white reference data acquired by the white reference data acquisition unit 12 and the black reference data acquired by the black reference data acquisition unit 13 to perform shading correction on the document data acquired by the reading control unit 11. To do.

  Specifically, the shading correction unit 14 calculates the difference value between the brightness value indicated by the document data acquired by the reading control unit 11 and the brightness value indicated by the black reference data, and the brightness indicated by the white reference data. The data obtained by dividing by the difference value between the brightness value and the brightness value indicated by the black reference data and multiplying this by the brightness upper limit value is used as the shading-corrected document data.

  Hereinafter, the flow of a document reading operation by the reading control unit 11, the white reference data acquisition unit 12, the black reference data acquisition unit 13, and the shading correction unit 14 will be described with reference to FIG.

  When an original is placed on the original tray 51 or the original placement glass 412 by the user and an operation for reading the original is started based on, for example, a copy function execution instruction input from the operation unit 36, the black reference The data acquisition unit 13 moves the carriage 47 to the lower part of the paper dust removing plate 413 (S1), and then causes the light sources 42a and 42b to emit light toward the black surface below the paper dust removing plate 413. Then, the CCD 49 is caused to output an image signal indicating an image obtained by reading the lower black surface of the paper dust removing plate 413, and the image signal is digitally converted to obtain black reference data (S2).

  Then, after moving the carriage 47 to the lower part of the white reference plate 414 (S3), the white reference data acquisition unit 12 irradiates the light sources 42a and 42b with light toward the white surface below the white reference plate 414. Then, the image signal indicating the image obtained by reading the lower white surface of the white reference plate 414 is output to the CCD 49, and the image signal is digitally converted to obtain white reference data (S4).

  For example, when an instruction to read a document in the ADF reading mode is given by a copy function execution instruction or the like input from the operation unit 36 (S5; ADF reading mode), the reading control unit 11 47 is moved in the reverse direction and moved to the lower part of the automatic document reading glass 411 (S6), then the document feeder 5 is driven to automatically read the document placed on the document tray 51. It is conveyed on the glass for glass 411 (S7).

  On the other hand, when it is instructed to read the document in the flood bed reading mode (S5; flood bed reading mode), the reading control unit 11 keeps the moving direction of the carriage 47 as it is and moves more than the white reference plate 414. The carriage 47 is moved to the lower part of the predetermined reading start position on the document placement glass 412 provided at the previous position (S8).

  When step S7 and step S8 are completed, the reading control unit 11 drives the light sources 42a and 42b, photoelectrically converts the reflected light from the document by the CCD 49, and outputs an image signal to thereby output one line in the main scanning direction. Document data obtained by reading an image of the document is acquired (S9). Then, the shading correction unit 14 uses the black reference data and the white reference data acquired in steps S2 and S4 to read the document data obtained by reading the image of the document for one line in the main scanning direction acquired in step S9. Is corrected for shading (S10).

  When reading of all lines is not completed (S11; NO), and when reading of the document is instructed in the ADF reading mode (S12; ADF reading mode), the reading control unit 11 After the original is further conveyed by one line to the original feeder 5 (S13), the process returns to step S9 to read the next line.

  On the other hand, when reading of all lines has not been completed (S11; NO), and when it is instructed to read a document in the flood bed reading mode (S12; flood bed reading mode), the reading control unit 11 After moving the carriage 47 one line ahead (S14), the process returns to step S9 to read the next line. When reading of all lines is completed (S11; YES), the reading control unit 11 ends the reading operation of the document.

  That is, an example of the image reading apparatus according to the present invention includes the image reading apparatus 4 and the control unit 10.

  For example, as shown in FIG. 4, the connecting unit C in the case where a plurality of reading units RU are connected by the connecting unit C to form a line sensor having a length corresponding to one line in the main scanning direction. FIG. 7 shows an example of a cross-sectional view.

  As shown in FIG. 7, the light sources 42 a and 42 b, for example, extend in the main scanning direction (perpendicular to the paper surface of FIG. 7) and are provided with a light emitting element at a time, and are emitted from the light guide. And a light guide white cover provided to reflect the reflected light toward the contact glass 410. Further, a black resin provided for adhering adjacent imaging lenses 48 and shielding light from between the lenses and a transparent resin for adhering a side plate at one end of the reading unit RU are used. A plurality of reading units RU are connected.

  In such a configuration, when light is emitted from the light sources 42a and 42b to the original on the contact glass 410, the light is emitted from the light guide not only by the reflected light from the original but also by the optical path indicated by the broken line in FIG. It is considered that the reflected light from the light guide and the light guide white cover is incident on the light receiving surface of the CCD 49, and the image of the document may be read in consideration of this brightness.

  In such a case, when the black reference data is obtained by digitally converting the image signal output from the CCD 49 without emitting light from the light sources 42a and 42b as in the prior art, the black reference data is, for example, As shown in FIG. 8A, a black image is shown throughout the main scanning direction.

  On the other hand, according to the configuration of the above embodiment, the black reference data acquisition unit 13 irradiates the black surface below the paper dust removing plate 413 with light from the light sources 42a and 42b, and reflects the reflected light from the surface, The black reference data is acquired by receiving the light emitted from the light guide and the reflected light from the white cover of the light guide that is incident on the optical path indicated by the broken line in FIG. That is, the black reference data includes, for example, light emitted from the light guide and the light guide at the position in the main scanning direction where the connecting portion C exists, as shown in FIGS. An image having streaks brighter than the original black and showing the influence of the reflected light from the white cover will be shown.

  For this reason, according to the configuration of the above embodiment, since the black reference data is acquired based on the reflected light actually reflected from the black document, the shading correction unit 14 actually includes the connecting unit C. Shading so as to cancel the bright streak image when the original image is read at the main scanning direction position, considering that the lighter color than the original color is black at the main scanning direction position other than the connecting portion C. Correction can be performed. On the other hand, as shown in FIG. 8A, when shading correction is performed using black reference data indicating a black image over the entire main scanning direction, the bright streaks shown in FIG. Cannot be canceled. Thus, according to the configuration of the above embodiment, shading correction can be performed with high accuracy.

  Further, the paper dust removing plate 413 is provided so that the upper surface comes into contact with the reading surface of the document being conveyed by the document feeder 5 and the adhered surface of the document is removed. It is also used as a document for acquiring reference data. For this reason, when performing shading correction, it is possible to omit a space for separately providing an original for acquiring black reference data in the image reading device 4, or to manually prepare an original for acquiring black reference data. It is possible to avoid troubles such as placing on the document placing glass 412.

  Further, the paper dust removing plate 413 and the white reference plate 414 are in a direction opposite to the direction in which the carriage 47 is moved by the reading control unit 11 from the position where reading of the image of the document is started in the flood bed reading mode. Has been placed.

  Therefore, the reading control unit 11 causes the black reference data acquisition unit 13 to acquire the black reference data without returning the moving direction of the carriage 47 to the opposite side before reading the image of the document in the flood bed reading mode. The white reference data acquisition unit 12 can acquire white reference data, and shading correction can be performed efficiently.

  However, the position where the white reference plate 414 is arranged is not limited to this. For example, the white reference plate 414 may be arranged at the end of the document placement glass 412 where the carriage 47 is moved by the reading control unit 11. Good.

  In the above embodiment, the example in which the image reading apparatus according to the present invention is applied to the multifunction machine 1 has been described. However, the present invention is not limited to this. An image reading apparatus according to the present invention includes a color printer for forming a color image, a scanner, a facsimile machine, and the like including an image forming unit that forms an image using data read by an image reading unit in the image reading device. You may apply to an image forming apparatus.

  In the above embodiment, the configurations and settings shown in FIGS. 1 to 6 are merely examples, and the present invention is not limited to the embodiment.

1 MFP (image forming device)
DESCRIPTION OF SYMBOLS 10 Control part 11 Reading control part 12 White reference data acquisition part 13 Black reference data acquisition part 14 Shading correction | amendment part 25 Image formation part 36 Operation part 4 Image reading apparatus 410 Contact glass 411 Automatic document reading glass 412 Original placement glass 413 Paper dust removal board (attachment removal member)
414 White reference plate (white reference member)
42a Light source 42b Light source 47 Carriage 48 Imaging lens (light guide portion in image reading portion)
49 CCD (light receiving unit in the image reading unit)
5 Document feeder (document feeder)

Claims (3)

A document transport section for feeding and transporting documents one by one;
A contact glass on which the document is placed;
A light source for illuminating the document;
An image reading unit that reads an image to be read that is irradiated with light from the light source;
A plate-like white reference member mounted on the contact glass;
A plate-like member having two surfaces mounted on the contact glass, wherein the first surface comes into contact with the reading surface of the document being conveyed by the document conveying section and removes the adhered matter on the document. A deposit removing member provided, wherein the second surface opposite to the first surface is black;
A white reference data acquisition unit that causes the image reading unit to read an image of the white reference member irradiated with light from the light source as a reading target, and acquires the read image as white reference data;
A black reference data acquisition unit for causing the image reading unit to read an image of the second surface of the deposit removing member irradiated with light from the light source as a reading target, and acquiring the read image as black reference data; ,
A reading control unit for executing a first reading process for causing the image reading unit to read an image of a document being conveyed by the document conveying unit as a reading target, and acquiring the read image as document data;
A shading correction unit that performs shading correction on the document data using the white reference data and the black reference data;
Equipped with a,
The light source is
Two light guides extending in the main scanning direction and provided with a light emitting element at one end;
Two light guide white covers that are respectively provided on the outer sides of the two light guides and reflect light emitted from the light guides toward the contact glass toward the space between the two light guides; ,
With
The image reading unit
A light receiving section that is long in the main scanning direction for photoelectrically converting the received light; and a light guide section that guides the light reflected by the reading target to the light receiving section, and the light guide section includes the main scanning direction. A plurality of light guide members connected to each other by using side plates so as to extend to each other, and by adhering the side plates of the predetermined number of light guide members adjacent to each other using a transparent resin. An image reading apparatus comprising a connecting portion that connects a predetermined number of light guide members so as to extend in the main scanning direction between the two light guides . The reading control unit
While the light source and the image reading unit are moved in the sub-scanning direction, the image reading unit can further execute a second reading process of reading the image of the document for each line in the main scanning direction and acquiring the document data. And
The adhering matter removing member and the white reference member are in a direction opposite to a direction in which the image reading unit is moved by the reading control unit from a position where reading of an image of a document is started by the second reading process. Placed in
The reading control unit causes the black reference data acquisition unit to acquire the black reference data before reading the image of the document by the second reading process, and before reading the image of the document by the second reading process. The image reading apparatus according to claim 1, wherein the white reference data acquisition unit acquires the white reference data. The image reading apparatus according to claim 1 or 2,
An image forming unit that forms an image using data read by the image reading unit;
An image forming apparatus comprising: