JP4988494B2 - Image reading apparatus and image forming apparatus - Google Patents

Description

  The present invention relates to an image reading apparatus that optically reads a document image and an image forming apparatus to which the image reading apparatus is applied.

  In an image forming apparatus such as a copying machine, generally, a scanner that optically reads a document image on an apparatus main body that performs an image forming operation, and an automatic document conveying device that automatically conveys a document to a document reading position of the scanner, Is equipped. The scanner includes a first contact glass that serves as a document reading area when the document is placed by hand, a second contact glass that serves as a document reading area when the document is automatically conveyed, a moving frame equipped with a light source, and a CCD. And the like. The moving frame is moved through the first or second contact glass while being moved for document reading scanning in the hand placement mode and stopped at a preset reading reference position in the automatic conveyance mode. Irradiate the original with light. Reflected light from the document is guided to the image sensor through a reflecting mirror and a lens arranged in the moving frame and the scanner housing.

In the automatic conveyance mode, it is desirable to prevent the document from being lifted or shaken as much as possible when the document is read. For this reason, the automatic document feeder is provided with a guide member and a roller member at a position corresponding to the upper side of the second contact glass. Further, Patent Document 1 discloses providing a gap adjusting means for adjusting a gap between the roller member and the second contact glass so as to cope with a difference in document thickness.
JP 2003-207856 A

  Usually, the automatic document feeder is rotatably attached to the scanner housing. Therefore, there may be a positional shift between the two due to an attachment error or the like. When a document is read in the automatic conveyance mode in a state where such a positional deviation exists, the document is irradiated with light at a position different from the original reading reference position, and the image becomes thin or fog occurs. Or blurring of the image may occur. The reading failure caused by such a positional shift cannot be handled by the gap adjusting means of Patent Document 1.

  Depending on the nature of the document, for example, a document with a high glossiness and a document with a low or no glossiness have different light reflection characteristics. Therefore, when the moving frame is stopped at one fixed position and light is irradiated and reflected light is received, high-quality image reading cannot be performed for both documents having different glossiness levels. There was a thing.

  The present invention has been made in view of the above points, and can cope with an attachment error between the automatic document feeder and the scanner housing, and can also be used for a plurality of types of documents having different properties such as glossiness. An object of the present invention is to provide an image reading apparatus capable of reading a high-quality image corresponding to automatic conveyance, and an image forming apparatus to which the image reading apparatus is applied.

An image reading apparatus according to one aspect of the present invention includes an automatic document conveying unit that automatically conveys a document to a predetermined document reading region, an imaging unit that receives an optical image of the document, and a moving frame that includes a light source. An optical system that irradiates the original with light at a reading reference position determined in the original reading area and guides the reflected light to the imaging means as the optical image , and contains the imaging means and the optical system And a housing in which the automatic document feeder is disposed on the upper surface, a position setting unit that changes the reading reference position by moving the moving frame, and a first document having a specific property. first reading mode or the second mode selection means for accepting a selection of either the second read mode corresponding to the document, the optimal reading reference position for the first document having a different nature from the first document The first reference position information and the second reference position information that is the optimum reading reference position for the second document are acquired in a state where the automatic document transport means is assembled on the upper surface of the housing. The storage unit that stores these in advance, and the storage unit when the mode selection unit accepts the selection, and when the selection is the first reading mode, the first reference position, the second reference position when a said second reading mode, to change the read reference position, and control means for controlling the position setting means, you comprising: a.

According to this configuration, even during automatic reading of a document, unlike the conventional case, the reading reference position is not fixed and can be changed to a reading reference position according to the nature of the document. Optical document reading corresponding to the document type can be performed. In addition, since the information of the first reference position and the second reference position is acquired in a state where the automatic document conveying means is assembled on the upper surface of the casing , the information is set in consideration of an attachment error of the automatic document conveying means. And can be prevented from being affected by the mounting error or the like.

Further, the optical system includes a moving frame equipped with a light source, said position setting means, by moving the movable frame, since changing the reading reference position, normally provided for the document manually placed reading The reading reference position can be set at the first reference position or the second reference position without adding a new mechanism by using the moving frame.

In the above configuration, the first document is a document that has a high gloss, the second document is not to want to be a document having a low gloss. According to this configuration, since the reading reference position can be set at an appropriate position according to the glossiness of the document, high-quality image reading can be performed regardless of the difference in glossiness.

An image forming apparatus according to another aspect of the present invention is an apparatus for performing an image forming operation for forming an image corresponding to the document image on a sheet based on the above-described image reading device and light reception data output from the imaging unit. you; and a body.

  According to the image reading apparatus or the image forming apparatus of the present invention, it is possible to set a reading reference position corresponding to a document type and perform optical document reading, so that a high-quality image can be obtained regardless of differences in document properties. Reading can be performed. Therefore, image formation faithful to the original image can be performed.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a schematic cross-sectional view showing an overall configuration of an image forming apparatus 1 according to an embodiment of the present invention. The image forming apparatus 1 includes an apparatus main body MB that performs an image forming operation, an image reading device RD placed on the upper surface of the apparatus main body MB, a post-processing device FD arranged on the left side surface of the apparatus main body MB, and an image reading device. And an operation panel OP attached to the device RD.

  The apparatus main body MB transfers and fixes a toner image formed on the basis of the image information of the original D read by the image reading apparatus RD onto the paper P, and discharges the toner image. The image forming unit 12, the fixing unit 13, the paper transport path 14, the paper discharge unit 15, the control circuit board 16 (control unit), and the like are housed.

  The paper feeding unit 11 is disposed below the main body 10 and supplies paper P on which an image is formed to the image forming unit 12. The paper feed unit 11 includes a plurality of paper feed cassettes 111 that store a large number of papers P in a stacked state, and paper feed rollers 112 that send out the papers P from the respective paper feed cassettes 111. The paper feeding unit 11 may include a manual paper feeding unit in which a user manually feeds paper.

  The image forming unit 12 generates a toner image and transfers the toner image onto the paper P. The photosensitive drum 121, the charging device 122, the exposure device 123, the developing device 124, a cleaning device and a transfer roller (not shown). 125 is included.

  The photosensitive drum 121 is provided so as to be able to rotate clockwise around an axis, and an electrostatic latent image and a toner image are formed on the peripheral surface while rotating. The charging device 122 applies a uniform charge to the peripheral surface of the photosensitive drum 121. The exposure device 123 forms an electrostatic latent image by irradiating the peripheral surface of the photosensitive drum 121 on which this uniform charge is formed with light rays based on the image information of the document image read by the image reading device RD. . The developing device 124 supplies toner to the electrostatic latent image formed on the peripheral surface of the photosensitive drum 121 to form a toner image. The cleaning device removes residual toner remaining on the circumferential surface of the photosensitive drum 121 after the transfer processing of the toner image onto the paper P and cleans it. The transfer roller 125 abuts on the photosensitive drum 121 to form a nip portion, and generates a bias voltage so that the toner image is transferred onto the paper P passing through the nip portion.

  The fixing unit 13 performs a fixing process for fixing the toner image transferred to the paper P to the paper P. The fixing unit 13 includes, for example, a fixing roller 131 having a heating element therein, and a pressure roller 132 whose peripheral surface is in contact with the peripheral surface of the fixing roller 131.

  The paper transport path 14 transports the paper P from the paper supply unit 11 through the image forming unit 12 and the fixing unit 13 toward the paper discharge unit 15 or the post-processing device FD. A pair of registration rollers 141 that stops and conveys the paper P in accordance with the timing of image formation by the image forming unit 12 and a first paper discharge roller pair that discharges the paper P toward the paper discharge unit 15 are provided on the paper conveyance path 14. 142 and a second paper discharge roller 143 pair for sending the paper P toward the post-processing device FD through a paper discharge port 144 provided on the left side surface of the main body 10. The paper discharge unit 15 is a part that receives the paper P after image formation. Here, a so-called in-body discharge type paper discharge unit is illustrated.

  The control circuit board 16 is a board on which a microprocessor (MPU) for electrically controlling the operation of each unit of the image forming apparatus 1 and various electronic components are mounted. The function of the control circuit board 16 will be described in detail later with reference to FIG. 4 as a control unit 60 in which the MPU and the like are shown in functional configuration.

  Referring also to FIG. 2, the image reading apparatus RD includes a scanner 20 disposed immediately above the apparatus main body MB, and an automatic document feeder (hereinafter referred to as ADF) 30 disposed on the upper surface of the scanner 20. The ADF 30 is rotatably attached to the housing of the scanner 20 on one side thereof. 1 and 2 show a state in which the ADF 30 is closed, but when the document is placed by hand, the ADF 30 is opened upward with the pivot support point as a fulcrum.

  The scanner 20 optically reads an image of the document D. The scanner 20 has a housing structure, and has a first contact glass 21 serving as a document reading region when the document is manually placed on the upper surface thereof, and a document reading region when the document D is automatically conveyed by the ADF 30. The second contact glass 22 is fitted.

  Inside the housing of the scanner 20, there are a light source 23, a first reflecting mirror 24, a second reflecting mirror 25, a third reflecting mirror 26, a condensing lens 27 (hereinafter referred to as an optical system), an image sensor 28 (imaging means), a first A first moving frame 291 and a second moving frame 292 are stored.

  The light source 23 irradiates the original placed on the first contact glass 21 or the original D passing through the second contact glass 22 with light for optical reading. The first to third reflection mirrors 24 to 26 and the condensing lens 27 are optical systems that form reflected light from the document D on the light receiving surface of the image sensor 28 as a light image of the document D. The image sensor 28 is a two-dimensional imaging sensor such as a CCD (charge coupled device) or an RGB line sensor, for example, and photoelectrically converts the optical image of the document D and outputs an analog electrical signal. The analog electric signal is converted into a digital electric signal, subjected to predetermined image processing, and then input to the control circuit board 16 as digital image data for image formation.

  The first moving frame 291 and the second moving frame 292 move inside the housing of the scanner 20 at different moving speeds while being linked to each other by driving of a not-shown moving frame driving unit (position setting means) composed of a stepping motor or the like. To do. The light source 23 and the first reflecting mirror 24 are mounted on the first moving frame 291, and the second reflecting mirror 25 and the third reflecting mirror 26 are mounted on the second moving frame 292. Here, the first moving frame 291 moves at twice the speed of the second moving frame 292. Therefore, both the moving frames 291 and 292 are located at the positions (home positions) indicated by solid lines in FIG. 2 or moved to arbitrary positions indicated by two-dot chain lines in FIG. The optical path length to 28 is kept constant.

  The ADF 30 automatically conveys the document D to the document reading area (second contact glass 22) of the scanner 20, and includes a document discharge table 31, a document feed table 32, a feed roller 33, a registration switch 34, and a registration roller pair. 35, a timing switch 36, a separation roller 37, a discharge roller pair 38, and a document pressing member 39.

  The document discharge table 31 is a table on which the document D after the reading process is discharged, and the document feed table 32 is a table on which the document D to be read is placed. The paper feed roller 33 and the separation roller 37 are in contact with each other to form a pair, and the original D is conveyed toward the second contact glass 22 while the originals D on the original feed table 32 are being turned one by one. The registration switch 34 and the registration roller pair 35 serve to regulate the front end of the document by regulating the oblique feeding of the document D before the document D is conveyed to the document reading position. The timing switch 36 detects the leading edge and trailing edge timing of the document D being conveyed. The paper discharge roller pair 38 discharges the document D after the reading process to the document discharge table 31.

  The document pressing member 39 is disposed to face the second contact glass 22 with a predetermined gap, and is a pressing member for allowing the document D to pass through the second contact glass 22 without being lifted or shaken. Here, a flat plate-like document pressing member 39 is illustrated, but a platen roller may be used instead. Note that a reading reference position of the document D (a position to which light from the light source 23 is irradiated) is set at a predetermined position in a region where the document pressing member 39 and the second contact glass 22 face each other. As will be described in detail later, this embodiment is characterized in that this reading reference position is variable depending on the nature of the document D, specifically the presence or absence of gloss.

  In the automatic reading mode in which the document D placed on the document feed table 32 is read, the first moving frame 291 and the second moving frame 292 on which the light source 23 is mounted are the home positions below the second contact glass 22. It is made immobile. The home position can be slightly shifted in accordance with the adjustment of the reading reference position described later. At the home position, the light source 23 irradiates the document D conveyed one by one by the ADF 30 from the back surface of the second contact glass 22. The reflected light is guided to the image sensor 28 as a light image of the document D through the first to third reflecting mirrors 24 to 26 and the condenser lens 27.

  On the other hand, in the manual reading mode in which an original placed by the user on the first contact glass 21 is read, the first moving frame 291 receives a driving force from the moving frame driving unit while irradiating the original with light, Move at a constant speed in the direction. The second moving frame 292 also moves to the right at a speed that is half that of the first moving frame 291. The reflected light from the document is similarly guided to the image sensor 28. After such a reading operation, the first moving frame 291 and the second moving frame 292 are moved leftward at a constant speed and returned to the home position.

  Returning to FIG. 1, the post-processing device FD includes a carry-in port 41 that receives paper P to be post-processed, a paper transport unit 42, a post-processing intermediate tray 43, a paper carry-out port 44, a stack tray 45, and the like. The paper transport unit 42 transports the paper to an appropriate place according to the type of post-processing. The intermediate tray 43 is a processing tray in which stapling processing such as edge binding and saddle stitching is performed. The stack tray 45 is configured to be movable up and down in the direction of the arrow in accordance with the number of sheets stacked from the paper exit 44. In addition, a punched portion of a punch hole (not shown) is provided.

  The operation panel OP is used by the user to input operation instruction information for the image forming apparatus 1. The operation panel OP includes a start key 51, a numeric keypad 52, a liquid crystal touch panel, and the like. The display unit 53 receives operation input and displays a status. And a mode selection switch 54 (mode selection means).

  In the automatic document reading using the ADF 30, the mode selection switch 54 is a first reading mode corresponding to at least a first document having a specific property, or a second document corresponding to a second document having a property different from that of the first document. One of the two reading modes is accepted. For example, the mode selection switch 54 accepts selection between a glossy (high gloss) thick original and a non-gloss (low gloss) plain original.

  The light reflection characteristics are different between a document having a high gloss level and a document having a low or no gloss level. Also, the thickness of the document may affect the light reflection characteristics. Therefore, in automatic document reading, when the first moving frame 291 on which the light source 23 is mounted is stopped at one fixed reading reference position and light irradiation and reflected light are received, the glossiness In some cases, high-quality image reading cannot be performed with respect to both originals having different values. Further, the ADF 30 is pivotably attached to the housing of the scanner 20, but a positional shift may occur between them due to an attachment error or the like. In this case, if the reading reference position is fixed, reading variations among apparatuses occur.

  In view of the above, in the present embodiment, optimum reading reference position information is acquired in advance according to the original properties such as glossiness of the original and stored in the image forming apparatus 1, and is selected by the mode selection switch 54. The reading reference position, that is, the position of the first moving frame 291 is finely adjusted according to the document type. The reading reference position information can be acquired, for example, after the ADF 30 is assembled in the production line of the image forming apparatus 1. Thereby, the problem of attachment error and mechanical error between the ADF 30 and the scanner 20 can be solved.

FIG. 3 is a schematic diagram of a main part of the image reading apparatus RD for explaining a method for obtaining the reading reference position information. For example, prepare a blank first and second manuscript with the following chromaticity, glossiness, and basis weight indicated by the L ^* a ^* b ^* color system recommended by the International Commission on Illumination (CIE) To do.
(1) First document: thick paper glossy Chromaticity = L ^* : 95, a ^* : 0, b ^* : 0, glossiness = about 40, basis weight = 120 g / m ²
(2) Second manuscript: plain paper no gloss Chromaticity = L ^* : 95, a ^* : 0, b ^* : 0, glossiness = 10 or less, basis weight = 80 g / m ²

  By passing the first document and the second document through the ADF 30, the first moving frame 291 (the irradiation position of the reading light L by the light source 23) is moved a plurality of times at a predetermined pitch, and the respective output values are compared. The reference position (reading reference position) of the first moving frame 291 in each document is specified.

  Specifically, it is set so that image data 100 ms after the timing switch 36 detects the leading edge of the document is recorded in the measurement memory. Then, the light source 23 (first moving frame 291) is set so that the reading reference position is the position “A0” in FIG. 3, that is, a position near one end of the document reading area. Thereafter, the first original is passed through the ADF 30 to irradiate the reading light L, and image data at the reading reference position A0 is acquired. Further, at the reading reference positions A1, A2, A3,... Set to the left of the reading reference position A0, for example, at a pitch of 0.5 mm, the first document is similarly passed through the ADF 30 to obtain image data. To do. The plurality of image data obtained in this way are compared, and for example, the reading reference position where the closest white data is acquired with 8-bit (256 gradations) data is specified as the reading reference position for the first document.

  Next, similarly, the second original is passed through the ADF 30, and the image data at the reading reference positions A0, A1, A2, A3,. Then, the obtained plurality of image data are compared, and the reading reference position where the data closest to white is acquired is specified as the reading reference position for the second document. If necessary, the same processing is performed for other document types, and reading reference position information is acquired.

  FIG. 4 is a block diagram showing an electrical configuration of the image forming apparatus 1. Here, the control circuit board 16 is functionally shown as the control unit 60. In addition, the sheet feeding unit 11, the image forming unit 12, the fixing unit 13, and the sheet conveyance path 14 provided in the apparatus main body MB of FIG.

  The control unit 60 (control unit) includes an image formation control unit 61, a reading control unit 62, and a reading reference position storage unit 63. Further, the scanner 20 is provided with a moving frame driving unit 201 (position setting means) including a stepping motor or the like that drives the first moving frame 291 and the second moving frame 292.

  The image formation control unit 61 controls each unit of the apparatus main body MB constituting the image forming unit 100 to form an image corresponding to the image of the document D on the paper P based on the light reception data output from the image sensor 28. . When a post-processing instruction is given, the image formation control unit 61 controls the operation of the post-processing device FD to execute predetermined post-processing.

  The reading control unit 62 controls the document reading operation by the scanner 20 and the ADF 30. As one of its specific functions, the reading control unit 62 gives a driving pulse to the moving frame driving unit 201 and performs movement control of the first moving frame 291 and the second moving frame 292. In the present embodiment, in automatic document reading using the ADF 30, when the reading mode corresponding to the document type is set by the mode selection switch 54 of the operation panel OP, the reading reference position is set for the document type. The reading control unit 62 controls the moving frame driving unit 201 so that the first moving frame 291 and the second moving frame 292 are positioned at the positions.

  The reading reference position storage unit 63 stores the reading reference position information acquired by the technique shown in FIG. 3 in association with the document type. FIG. 5 is a table format showing an example of the reading reference position information table 70 stored in the reading reference position storage unit 63. Here, the reading reference positions A0, A1, A2, A3,... Are determined for each document type such as “no plain paper gloss”, “thick paper gloss”, “no thick paper gloss”, and “plain paper color”. An example is shown. When an instruction for selecting a document type is given by the mode selection switch 54, the reading control unit 62 refers to the reading reference position information table 70 and controls signals S0, S1, and S2 set in advance according to the document type. , S3... Are given to the moving frame driving unit 201.

  Next, the operation of the image forming apparatus 1 configured as described above will be described based on the flowchart shown in FIG. In a standby state for image formation such as a copy operation, the reading control unit 62 positions the first moving frame 291 and the second moving frame 292 at the default position (home position) (step S1). When it is already at the home position, no action is taken.

  Next, the reading control unit 62 determines whether or not the document D is placed on the document feed table 32 of the ADF 30 (step S2). When the ADF 30 is not fed and the ADF 30 is opened to place the original by hand (NO in step S2), the conventional manual reading mode is executed. On the other hand, when the document sensor or the like detects that the document D is placed on the document feed table 32 (YES in step S2), the reading control unit 62 selects the reading mode from the mode selection switch 54 on the operation panel OP. It is confirmed whether a selection instruction (for example, selection of glossy or not) is given (step S3).

  When an instruction to select a reading mode is given (YES in step S3), the reading control unit 62 refers to the reading reference position information table 70 of the reading reference position storage unit 63 and the first moving frame 291 and the second moving frame 291. It is determined whether or not the movement frame 292 needs to be moved (step S4). If the reading reference position of the set reading mode is different from the current position (reading reference position) of the first moving frame 291 and the second moving frame 292 (YES in step S4), the moving frame driving unit 201 is moved. By operating, the first moving frame 291 and the second moving frame 292 are moved to a predetermined reading reference position (step S5). Note that if the reading mode selection instruction is not given (NO in step S3), and if the movement of the first moving frame 291 and the second moving frame 292 is unnecessary (NO in step S4), steps S4 to S4 are performed. Step S5 is skipped.

  In this state, the reading control unit 62 waits for a document reading instruction operation from the operation panel OP (step S6). If the reading instruction operation is not given (NO in step S6), the process returns to step S3 and is repeated. On the other hand, when a reading instruction operation is given (YES in step S6), the reading control unit 62 operates the ADF 30 and the scanner 20 to execute image reading of the document D (step S7). At this time, since the reading reference position is adjusted according to the reading mode given by the mode selection switch 54, high-quality image reading can be performed.

  Thereafter, the image formation control unit 61 operates the image forming unit 100 based on the read image data to form an image on the paper P (step S8). Further, when a post-processing instruction is given (YES in step S9), the image formation control unit 61 operates the post-processing device FD to execute post-processing as instructed (step S10).

  As described above, according to the image reading apparatus RD or the image forming apparatus 1 according to the present embodiment, for example, a reading reference position is set corresponding to a document type such as the presence or absence of gloss, and optical document reading is performed. Therefore, it is possible to prevent fogging and blurring and to perform high-quality image reading without being affected by flare light regardless of the difference in the properties of the document. Therefore, image formation faithful to the original image can be performed.

  The image forming apparatus 1 according to the embodiment of the present invention has been described above, but the present invention is not limited to this, and for example, the following embodiment can be taken.

[1] In the above embodiment, the image forming apparatus 1 that performs the monochrome copying operation of the document D is illustrated as an example of the image forming apparatus. Needless to say, the present invention can also be applied to other image forming apparatuses such as a color copying machine, a facsimile machine, or a complex machine thereof.

[2] In the above embodiment, an example in which the reading mode (reading reference position) is set according to the presence or absence of gloss exclusively. However, the present invention is not limited to this, and the reading reference position may be adjusted according to the thickness, translucency, color, stiffness, paper material, recycled paper, and the like.

[3] In the above embodiment, the mode selection switch 54 for selecting the reading mode is provided on the operation panel OP. However, the mode selection is performed by a personal computer connected to the image forming apparatus 1 so as to be able to perform data communication, You may make it carry out with a portable terminal machine.

[4] In the above embodiment, the first contact glass 21 that becomes a document reading area when the document is placed by hand, and the second contact glass 22 that becomes a document reading area when the document D is automatically conveyed by the ADF 30. An example of a scanner 20 provided with However, the present invention can also be applied to a scanner device that does not have a manual reading unit. In the above-described embodiment, an example in which the reading reference position is adjusted by moving the first moving frame 291 and the second moving frame 292 has been described. However, the present invention is not limited to this. The reading reference position may be adjusted by a method for adjusting the reading.

1 is a schematic cross-sectional view illustrating an overall configuration of an image forming apparatus according to an embodiment of the present invention. FIG. 2 is an enlarged view of an image reading apparatus provided in the image forming apparatus of FIG. 1. It is a principal part schematic diagram of the image reading apparatus for demonstrating the acquisition method of reading reference position information. 2 is a block diagram illustrating an electrical configuration of the image forming apparatus. FIG. It is a figure of a table format which shows an example of a reading reference position information table. 3 is a flowchart illustrating an operation of the image forming apparatus.

DESCRIPTION OF SYMBOLS 1 Image forming apparatus MB Apparatus main body RD Image reading apparatus FD Post-processing apparatus OP Operation panel 10 Main body body 12, 100 Image forming part 16 Control circuit board (control means)
20 Scanner 201 Moving frame drive unit (position setting means)
21 First contact glass 22 Second contact glass (document reading area)
23 Light source 28 Image sensor (imaging means)
291, 292 First moving frame, second moving frame 30 Automatic document feeder (ADF: automatic document feeder)
54 Mode selection switch (mode selection means)
60 Control part (control means)
61 Image formation control unit 62 Reading control unit 63 Reading reference position storage unit

Claims (3)

Automatic document conveying means for automatically conveying a document to a predetermined document reading area;
Imaging means for receiving an optical image of the original;
An optical system that includes a moving frame mounted with a light source, irradiates the original with light at a reading reference position determined in the original reading area, and guides the reflected light to the imaging means as the optical image;
A housing that houses the imaging means and the optical system, and on which the automatic document feeder is disposed;
Position setting means for changing the reading reference position by moving the moving frame ;
Mode selection means for receiving selection of either a first reading mode corresponding to a first document having a specific property or a second reading mode corresponding to a second document having a property different from that of the first document;
Information on the first reference position, which is the optimum reading reference position for the first document, and information on the second reference position, which is the optimum reading reference position for the second document, are displayed on the upper surface of the housing. A storage unit that is acquired in a state in which the automatic document feeder is assembled and stores these in advance;
When the mode selection unit accepts the selection, the storage unit is referred to. When the selection is in the first reading mode, the mode is selected. Control means for controlling the position setting means to change the reading reference position to a second reference position ;
An image reading apparatus comprising:   2. The image reading apparatus according to claim 1, wherein the first document is a document having a high glossiness, and the second document is a document having a low glossiness. The image reading apparatus according to claim 1 or 2 ,
An apparatus main body that performs an image forming operation for forming an image corresponding to the document image on a sheet based on light reception data output from the imaging unit;
An image forming apparatus comprising:

Images