JP4968003B2 - Image reading device - Google Patents

Description

The present invention relates to an image reading equipment sheet through method of generating image data of an image of the document conveyed by the automatic document feeder is read via a reading unit.

  Conventionally, in an image reading apparatus such as a scanner, there has been proposed a method for removing foreign matter (paper dust or the like) adhering to a conveying means (for example, a conveying belt or a conveying roller) that conveys a document.

  According to the method described in Patent Document 1, a cleaning sheet coated with a weak adhesive material on a substrate is transported on a paper transport path, and paper dust and dust on the paper transport path are formed on the cleaning sheet by adhesive force. Adhere to. The cleaning sheet describes attribute information, and the attribute information is read by the reading unit. Based on the read attribute information, the pressing force with which the cleaning target members on the cleaning sheet conveyance path and the cleaning sheet are pressed against each other is controlled.

  Patent Document 2 proposes a cleaning method for a transport roller that transports a document. Here, the sheet conveying rollers are configured as a pair of upper and lower sheets, and the cleaning sheet passes between the pair of sheet conveying rollers and is conveyed. The force for holding the cleaning sheet by the pair of sheet conveyance rollers is configured to be changed between the sheet conveyance and the cleaning operation.

Further, according to the method described in Patent Document 3, the dirt attached to the document transport belt is removed by rubbing the cleaning sheet and the document transport belt.
Japanese Patent Laid-Open No. 7-114314 JP-A-5-238580 JP-A-6-040586

  However, in the method according to Patent Document 1, it is necessary to provide attribute information on the cleaning sheet, and a mechanism for changing the pressing force between the cleaning target member and the cleaning sheet is also required, so that the cost can be reduced. Can not.

  Further, as a further problem, in an automatic document feeder (ADF) provided in an image reading apparatus such as a scanner, foreign matter (paper dust or the like) from the original adheres to the glass plate of the image reading unit, thereby producing an output image. Streaks (muscle noise) may occur. It is a big problem to suppress the generation of the streak noise.

  However, Patent Documents 1 to 3 propose a cleaning method for the conveyance belt and the conveyance roller, but do not propose a method for removing foreign matter attached to a glass plate as an image reading unit.

  In addition, foreign matter on the glass plate may be detected by a CCD (charge coupled device) or the like, and a message indicating the presence of foreign matter may be displayed on the operation panel. In this case, a user visually cleans the liquid crystal display on the operation panel and manually cleans the glass plate, but this method is very laborious.

  The present invention has been made in view of such problems, and an object of the present invention is to remove foreign matter adhering to the surface of a reading unit without incurring costs.

An image reading apparatus according to an aspect of the present invention is a sheet-through type image reading apparatus that generates an image data by reading an image of a document conveyed by an automatic document feeder via a reading unit, and the automatic document The feeding device is provided with an upstream front roller and a downstream rear roller sandwiching the reading unit, and a discriminating means for discriminating whether a document is conveyed or a cleaning sheet is conveyed, and When it is determined by the determining means that the document is conveyed by the automatic document feeder before reaching the front roller, the conveyance speed of the front roller is set to be equal to or less than the conveyance speed of the rear roller. so as not to contact with a document on the reading unit, also arrives to the front roller that the cleaning sheet is conveyed by the automatic document feeder Sometimes it is discriminated by said discriminating means before, the cleaning sheet by deflecting toward the front roller The cleaning sheet was faster than the conveying speed of the rear roller the conveying speed of the surface of the reading portion in so that be conveyed in a state in contact with the reading unit, the switching control means for switching the paper passing state of the document or the cleaning sheet is provided.

  According to the present invention, it is possible to remove foreign matter adhering to the surface of the reading unit without incurring costs.

  FIG. 1 is a plan view showing an internal configuration of the image reading apparatus 1 according to the present embodiment, and FIG. 2 is a block diagram showing a configuration of a main control system in the image reading apparatus 1.

  As shown in FIG. 1, an image reading apparatus 1 according to the present embodiment is a sheet-through system that reads a document while the document is being conveyed, and is mainly referred to as a scanner unit 2 and an automatic document feeder (hereinafter referred to as “ADF”). ) 3.

  The scanner unit 2 includes a CCD (Charge-Coupled Device) 11 as image reading means, mirrors 12a, 12b, 12c, a reading unit 13, and the like.

  The ADF 3 includes a document tray 20, a roller-feeding unit 21, a reading conveyance unit 22 that reads a document fed from the feeding unit 21, and passes above the reading unit 13. A first conveyance path switching unit 23, a second conveyance path switching unit 24, and a third conveyance path switching unit 25 that switch conveyance paths, a discharge guide unit 26 that guides a document to a discharge roller, which will be described later, and a discharge that is described later. A discharge roller 27 for discharging to the tray, a discharge tray 28 for storing the discharged document, and a reversing table 29 are included. The reading and conveying unit 22 will be described in detail later.

  The CCD 11 receives reflected light from the document passing above the reading unit 13 by the reading conveyance unit 22 via the mirrors 12a, 12b, and 12c, and generates image data based on the received reflected light.

  In the ADF 3, the following processing is performed. In the following, a case where images on both sides of a document are read will be described.

  The documents placed on the document tray 20 are conveyed along the path K1. That is, the original is first conveyed to the reading conveyance unit 22 by the paper supply unit 21. By passing through the reading conveyance unit 22, the image of the original is read by the reading unit 13. The read original is sent to the reversing table 29 via the first transport path switching unit 23 and the second transport path switching unit 24. In addition, the 1st conveyance path switching part 23 and the 2nd conveyance path switching part 24 are rotated beforehand by the predetermined position. By such a method, the image of one surface (for example, the front surface) of the document is read by the CCD 11.

  Next, a case where an image on the other side (for example, the back side) of the original is read will be described. As described above, the document sent to the reversing table 29 is conveyed in the ADF 3 along the path K2. In other words, the document is conveyed again to the reading conveyance unit 22 via the first conveyance path switching unit 23 and the second conveyance path switching unit 24. In this case, the second transport path switching unit 24 maintains the same position as when the path K1 is formed, and the first transport path switching unit 23 is rotated upward in the drawing. The original conveyed again to the reading conveyance unit 22 is sent to a predetermined position after an image is read by the reading conveyance unit 22. Note that the third transport path switching unit 25 is previously rotated to a predetermined position.

  Subsequently, the document sent to a predetermined position in the ADF 3 is discharged along the path K3. That is, the document is discharged to the discharge tray 28 by the discharge roller 27 through the third conveyance path switching unit 25 and the discharge guide unit 26. In this case, the third transport path switching unit 25 is rotated upward in the drawing. By such a method, the image on the other side of the document is read by the CCD 11.

  As shown in FIG. 2, the scanner unit 2 includes a scanner CPU (central processing unit) 31, a first motor driving unit 32 including an integrated circuit, a scanner unit motor 33, an image processing unit 34, a memory 35, and a touch panel type. And an operation panel 36 including a liquid crystal display, a numeric keypad, and the like. The operation panel 36 includes a selection key for the user to select a normal process for reading an image of a document or a cleaning process for cleaning a reading unit described later.

  The ADF 3 includes an ADF CPU 41, second to eighth motor driving units 42 to 48 including an integrated circuit, a paper feeding unit motor 49 for operating the paper feeding unit 21, a pre-reading motor 50 for operating a pre-reading roller described below, and a below-described motor. A post-reading motor 51 that operates the post-reading roller, a discharge unit motor 52 that operates the discharge roller 27, a conveyance guide rotation motor 53 that operates a conveyance guide described later, a step sheet moving motor 54 that operates a step sheet described later, and It further includes a reading unit moving motor 55 that operates a reading unit described later. The scanner CPU 31 and the ADF CPU 41 communicate with each other.

  In the scanner unit 2, the first motor drive unit 32 rotates the scanner unit motor 33 under the control of the scanner CPU 31. The scanner motor 33 is for scanning the mirror 12a shown in FIG. 1 when reading a document by the fixed table reading method.

  The image processing unit 34 performs various image processing and compression processing on the image data obtained by the CCD 11, stores the processed image data in the memory 35, and stores the image data in the memory 35 if necessary. Read from. In addition, the image processing unit 34 displays various screens on the liquid crystal display of the operation panel 36. Furthermore, the user can give various commands to the scanner CPU 31 by operating the operation panel 36.

  In the ADF 3, the second to eighth motor driving units 42 to 48 are controlled by the ADF CPU 41 so that the paper feeding unit motor 49, the pre-reading motor 50, the post-reading motor 51, the discharging unit motor 52, the conveyance guide rotating motor 53, and the steps. The sheet moving motor 54 and the reading unit moving motor 55 are rotationally driven.

  Next, a detailed configuration of the image processing unit 34 in FIG. 2 will be described with reference to the drawings. FIG. 3 is a block diagram illustrating an example of a functional configuration of the image processing unit 34.

  As shown in FIG. 3, the image processing unit 34 includes an A / D (analog / digital) conversion unit 61, a shading correction unit 62, a lightness / color difference separation unit 63, a foreign matter detection unit 64, an image adjustment unit 65, and a color space conversion unit. 66, a compression / decompression unit 67, and the like.

  First, the A / D converter 61 converts R, G, and B color image signals from the CCD 11 into R, G, and B color image data (hereinafter referred to as 256-gradation density data) as 8-bit digital data (256-gradation density data). , Referred to as “image data D1”).

  The shading correction unit 62 performs a shading correction for correcting so-called scanner unevenness (sensitivity variation of each pixel of the CCD 11 and uneven light distribution, etc.) on the obtained image data D1.

  The lightness / color difference separating unit 63 converts the image data D1 after shading correction into data (for example, 256 gradation digital data) indicating Y (lightness), Cr (red difference), and Cb (blue difference) by matrix calculation or the like. Convert. That is, the image data D1 is separated into lightness information and color difference information.

  Further, the foreign matter detection unit 64 determines whether or not foreign matter (for example, paper dust) exists in the reading unit described later based on the image data D1 after shading correction, and when the foreign matter exists in the reading unit. In addition, a message indicating that there is a foreign object is displayed on the liquid crystal display of the operation panel 36.

  The image adjustment unit 65 performs a filtering process on the brightness information data, and adjusts sharpness (smoothness) or smoothness (smoothing) of a document image. The image adjustment unit 65 adjusts hue, saturation, density, and the like by multiplying the Cr and Cb values by coefficients.

  The color space conversion unit 66 calculates an RGB color space value based on the Y, Cr, and Cb values of the pixel of interest adjusted by the image adjustment unit 65, and calculates this value in the CIE-Lab color space. Convert to value.

  The compression / decompression unit 67 compresses the image data D1 obtained by the color space conversion unit 66 in a predetermined format, and stores the compressed image data D1 in the memory 35. The compression / decompression unit 67 reads the image data D1 stored in the memory 35 and decompresses (decompresses) the image data D1.

  Next, the configuration and operation of the reading conveyance unit 22 and the reading unit 13 will be described in detail with reference to the drawings.

  4 is a diagram illustrating the configuration and operation of the reading conveyance unit 22 and the reading unit 13 when conveying an original, and FIG. 5 is a diagram illustrating the configuration and operation of the reading conveyance unit 22 and the reading unit 13 when conveying a cleaning sheet. It is.

  As shown in FIGS. 4A and 5A, the reading conveyance unit 22 includes a pre-reading roller 71, a post-reading roller 72, a conveyance guide 73, a step sheet 74, a guide base 75, a guide plate 76, and a conveyance. It consists of a confirmation sensor 77 and the like. The reading unit 13 is made of, for example, a glass plate.

  The pre-reading roller 71 and the post-reading roller 72 are arranged above the reading unit 13 and are configured by a pair of rollers each including a driving roller and a free roller (non-driving roller) having a smaller diameter than the driving roller. A document G or a cleaning sheet CS is sandwiched between the driving roller and the free roller, and is conveyed toward the right side of the drawing by the rotation of the driving roller and the free roller.

  The diameter of the drive roller is 20 mm, for example. The cleaning sheet CS is coated with, for example, a weak adhesive material and has a thickness of 0.1 to 0.2 mm. The distance between the driving roller of the pre-reading roller 71 and the driving roller of the post-reading roller 72 is, for example, 100 mm. Further, the thickness of the step sheet 74 is 0.4 mm, for example.

  The conveyance guide 73 is rotatably provided in the vicinity of the pre-reading roller 71 so as to support the original G or the cleaning sheet CS after being conveyed by the pre-reading roller 71.

  The step sheet 74 is made of stainless steel or the like, and is slidably provided on the reading unit 13 so as to adjust the non-contact of the original G to the reading unit 13 and the contact of the cleaning sheet CS to the reading unit 13. ing. In this case, the surface of the step sheet 74 on the reading unit 13 side is coated with a resin material having lubricity such as Teflon (registered trademark). The step sheet 74 may be provided so as to be movable without being brought into contact with the reading unit 13.

  The guide table 75 is provided on the reading unit 13 in the vicinity of the post-reading roller 72 so as to support the original G or the cleaning sheet CS before being conveyed by the post-reading roller 72.

  The guide plate 76 is made of a sheet metal made of stainless steel or the like, and is arranged above the conveyance path of the document G or the cleaning sheet CS, and guides the document G or the cleaning sheet CS. The distance between the guide plate 76 and the original G at the reading position PY near the center of the guide plate 76 is about 1.2 mm.

  The conveyance confirmation sensor 77 is disposed in the vicinity of the pre-reading roller 71 and detects whether the document G or the cleaning sheet CS has reached the position immediately before the pre-reading roller 71. That is, the conveyance confirmation sensor 77 confirms whether the document G or the cleaning sheet CS is conveyed by the pre-reading roller 71.

  In the present embodiment, when the document G is conveyed, the document G is prevented from contacting the reading unit 13. That is, as shown in FIG. 4A, the conveyance guide 73 is rotated to a position (reading position) where the original G can be supported so that the portion of the original G that has passed the pre-reading roller 71 is not greatly inclined. 74 moves to the vicinity of the center of the reading unit 13 (a position away from the reading position PY, for example, 6 mm: avoidance position). By such a method, the original G is prevented from coming into contact with the reading unit 13. Note that the distance between the reading unit 13 and the original G at the reading position PY near the center of the reading unit 13 is about 1 mm.

  On the other hand, when the cleaning sheet CS is conveyed, the cleaning sheet CS is brought into contact with the reading unit 13. That is, as shown in FIG. 5A, the conveyance guide 73 can support the cleaning sheet CS such that the portion of the cleaning sheet CS that has passed the pre-reading roller 71 is inclined more than in the case of the document G described above. Rotated to (cleaning position), the step sheet 74 moves to a position (retracted position) separated from the vicinity of the center of the reading unit 13. By such a method, the cleaning sheet CS moves while being in contact with the surface of the reading unit 13, and the foreign matter existing on the reading unit 13 can be attached to the cleaning sheet CS and removed.

  Here, the control of the pre-reading motor 50 that drives the pre-reading roller 71 and the post-reading motor 51 that drives the post-reading roller 72 will be described separately for the case of conveying the original G and the case of conveying the cleaning sheet CS. .

  First, a control example when the original G is conveyed will be described. As shown in FIG. 4B, when the document G is detected by the conveyance confirmation sensor 77, the pre-reading motor 50 and the post-reading motor 51 both start rotating at time t1. The rotation speed v1 of the motor 50 before reading is equal to or lower than the rotation speed v2 of the motor 51 after reading. In this case, since the conveyance amount (conveyance length) of the original G per unit time by the pre-reading roller 71 is equal to or less than the conveyance amount of the original G per unit time by the post-reading roller 72, the original G is greatly bent. Is prevented.

  By adopting such a control method (hereinafter referred to as “non-loop control”), the original G can be conveyed without being brought into contact with the reading unit 13 without causing a large deflection of the original G.

  Even when the conveyance guide 73 is rotated to the cleaning position and the step sheet 74 is moved to the retracted position as in the case of conveying the cleaning sheet CS, the original G is read by the reading unit 13 by adopting the above control method. It is conveyed without touching.

  Next, an example of control when the cleaning sheet CS is conveyed will be described. As shown in FIG. 5B, when the cleaning sheet CS is detected by the conveyance confirmation sensor 77, both the pre-reading motor 50 and the post-reading motor 51 start to rotate at time t1, but the rotation of the pre-reading motor 50 rotates. The speed v3 is larger than the rotational speed v2 of the post-reading motor 51. In this case, since the conveyance amount of the cleaning sheet CS per unit time by the pre-reading roller 71 is larger than the conveyance amount of the cleaning sheet CS per unit time by the post-reading roller 72, the cleaning sheet CS is greatly bent. .

  Further, another example of the control in the case of conveying the cleaning sheet CS will be described. As shown in FIG. 5C, the rotational speed v1 of the pre-reading motor 50 and the rotational speed v2 of the post-reading motor 51 are equal, but when the cleaning sheet CS is detected by the conveyance confirmation sensor 77, the pre-reading motor 50 While the rotation starts at time t1, the post-reading motor 51 starts to rotate at time t2 delayed from time t1. That is, in the time (T1 + T2) from the time t1 until the time t2 elapses, the post-reading roller 72 does not rotate and maintains the stopped state.

  In this case, the leading edge of the cleaning sheet CS reaches the post-reading roller 72 when the time T1 has elapsed. Thereafter, until the time T2 elapses from this point, the post-reading roller 72 maintains the stopped state, and starts rotating at the time t2 when the time T2 elapses. As a result, the cleaning sheet CS is greatly bent.

  By adopting these control methods (hereinafter referred to as “loop control”), the cleaning sheet CS can be largely bent, and the cleaning sheet CS can be brought into contact with the reading unit 13 and conveyed. .

  Even when the conveyance guide 73 is rotated to the reading position and the step sheet 74 is moved to the avoidance position as in the case of conveying the original G, the thickness of the step sheet 74 is very thin, for example, 0.4 mm. Therefore, by adopting the above control method, the cleaning sheet CS is conveyed while being in contact with the reading unit 13.

  Next, initial processing, normal processing, and cleaning processing by the image reading apparatus 1 according to the present embodiment will be described with reference to the drawings. The initial process is a process performed before the normal process and the cleaning process, and the normal process is a process for reading an image of the original G.

  6 is a flowchart showing main processing of the image reading apparatus 1, FIG. 7 is a flowchart showing initial processing of the image reading apparatus 1, FIG. 8 is a flowchart showing normal processing and cleaning processing of the image reading apparatus 1, and FIGS. 12 is a flowchart showing loop control in the cleaning process, and FIG. 13 is a diagram for explaining a range in which the loop control is performed in the cleaning sheet CS.

  As shown in FIG. 6, initial processing is performed (# 1), and normal processing or cleaning processing is performed (# 2).

  As shown in FIG. 7, the following processing is performed as initial processing. First, foreign object detection processing is performed (# 11). Specifically, the reading unit moving motor 55 moves the reading unit 13 in a predetermined direction within a predetermined range. The CCD 11 receives reflected light from the reading unit 13 and generates image data.

  If the image data obtained by the CCD 11 is equivalent to a foreign object (Yes in # 12), the operation panel 36 displays a message indicating that there is a foreign object on the liquid crystal display (# 13). After the process of # 13 and when no foreign matter exists (No in # 12), the normal process or the cleaning process (# 2) is performed.

  As shown in FIG. 8, the following processing is performed as normal processing or cleaning processing. First, it is determined whether the normal process or the cleaning process is selected by the user operating the selection key on the operation panel 36 (# 21). The user sets the document G on the document tray 20 when normal processing is desired, and sets the cleaning sheet CS on the document tray 20 when cleaning processing is desired.

  When the cleaning process is selected by the user (Yes in # 21), loop control is performed (# 22). On the other hand, when the cleaning process is not selected by the user, that is, when the normal process is selected (No in # 21), non-loop control is performed (# 23).

  9 to 12, four examples will be described as loop control.

  As shown in FIG. 9, first, the third motor driving unit 43 and the fourth motor driving unit 44 wait for the conveyance confirmation sensor 77 to detect the cleaning sheet CS, and then the pre-reading motor 50 and the post-reading motor respectively. By rotationally driving 51, the pre-reading roller 71 and the post-reading roller 72 are simultaneously rotationally driven at the same rotational speed (# 31). Then, the conveyance of the cleaning sheet CS is started.

  Subsequently, the ADFCPU 41 determines whether or not the pre-reading roller 71 has made one rotation based on the output result of an encoder (not shown), that is, whether or not the cleaning sheet CS has been conveyed a distance corresponding to the circumference of the pre-reading roller 71. Is discriminated (# 32). If the cleaning sheet CS has not been conveyed a distance corresponding to the circumference of the pre-reading roller 71, the conveyance is continued (No in # 32).

  On the other hand, when the cleaning sheet CS has been transported a distance corresponding to the circumference of the pre-reading roller 71 (Yes in # 32), the post-reading motor 51 is rotationally driven at a lower rotational speed than the pre-reading motor 50 (# 33). ).

  As another example, as shown in FIG. 10, first, the third motor driving unit 43 rotates and drives the pre-reading motor 50 after waiting for the conveyance confirmation sensor 77 to detect the cleaning sheet CS. The pre-reading roller 71 is rotationally driven (# 41). Then, after a predetermined time (time T1 + T2: FIG. 5) has elapsed, the fourth motor drive unit 44 rotates the post-reading motor 51 by rotating the post-reading motor 51 (# 42).

  As another example, as shown in FIG. 11, first, after the cleaning confirmation CS 77 is detected by the conveyance confirmation sensor 77, the sixth motor driving unit 46 drives the conveyance guide motor 53 to rotate. The conveyance guide 73 is rotated to the cleaning position (# 51). The third motor driving unit 43 and the fourth motor driving unit 44 rotate the pre-reading motor 50 and the post-reading motor 51, respectively, so that the pre-reading roller 71 and the post-reading roller 72 rotate simultaneously at the same rotational speed. Drive (# 52).

  In this case, since the conveyance guide 73 is at the cleaning position, the cleaning sheet CS is sent in a state of being bent downward and contacts the reading unit 13. Thereafter, the leading edge of the cleaning sheet CS reaches the post-reading roller 72, and the cleaning sheet CS is conveyed in a bent state. In this case, the cleaning sheet CS contacts the reading unit 13, but the shape and arrangement of the step sheet 74 may be considered so as not to be hindered by the step sheet 74.

  Furthermore, as another example, as shown in FIG. 12, the seventh motor driving unit 47 first drives the step sheet moving motor 54 to rotate after the conveyance confirmation sensor 77 detects the cleaning sheet CS. As a result, the step sheet 74 is moved to the retracted position (# 61). The third motor driving unit 43 and the fourth motor driving unit 44 rotate the pre-reading motor 50 and the post-reading motor 51, respectively, so that the pre-reading roller 71 and the post-reading roller 72 rotate simultaneously at the same rotational speed. Drive (# 62).

  Also in this case, since the step sheet 74 is in the retracted position, the cleaning sheet CS is sent in a state of being bent downward and contacts the reading unit 13. Thereafter, the leading edge of the cleaning sheet CS reaches the post-reading roller 72, and the cleaning sheet CS is conveyed in a bent state. In this case, the cleaning sheet CS contacts the reading unit 13, but the shape and arrangement of the conveyance guide 73 may be taken into consideration so as not to be hindered by the conveyance guide 73.

  The cleaning sheet CS is conveyed in contact with the reading unit 13 by these loop controls.

  Here, as described with reference to FIG. 9, the pre-reading roller 71 and the post-reading roller 72 are simultaneously rotated at the same rotational speed, and the cleaning sheet CS is conveyed by a distance corresponding to the circumference of the pre-reading roller 71. The reason for adopting (hereinafter referred to as “foreign matter contamination prevention method”) will be described.

  In many cases, foreign substances are attached to the paper feeding unit 21 when the original G is fed. As a result, as shown in FIG. 13, the range HA that is not subject to loop control, that is, the range HA from the front end (right end of the drawing) of the cleaning sheet CS to the distance RI corresponding to the circumference of the paper feed unit 21, Foreign matter may adhere when feeding paper. In view of this, the range HA in the cleaning sheet CS is not used for removing foreign matter in the reading unit 13, but the range excluding the range HA is used for removing foreign matter in the reading unit 13. As a result, the reading unit 13 is prevented from being contaminated by foreign matters during feeding that adhere to the range HA of the cleaning sheet CS. It should be noted that such a foreign matter contamination prevention method can also be applied to each loop control of FIGS.

(Effect in this embodiment)
In the present embodiment, when performing the cleaning process, the cleaning sheet CS is conveyed in a state of being in contact with the reading unit 13, whereby foreign matters on the reading unit 13 can be sufficiently removed. Further, when normal processing is performed, the document G is transported without being in contact with the reading unit 13, thereby preventing foreign matter present on the document G from adhering to the reading unit 13.

  In the present embodiment, the original G can be conveyed without being brought into contact with the reading unit 13 mainly by the control of the pre-reading roller 71 and the post-reading roller 72, or the cleaning sheet CS is in contact with the reading unit 13. Since it can be transported, there is no cost.

  In addition, the configuration of the entire image reading apparatus 1 or each unit, the processing content, the processing order, and the like can be appropriately changed in accordance with the spirit of the present invention. In this case, the above-described unique and exceptional effects can be obtained. Is done.

1 is a plan view illustrating an internal configuration of an image reading apparatus according to an embodiment. 2 is a block diagram illustrating a configuration of a main control system in the image reading apparatus. FIG. It is a block diagram which shows the example of a functional structure of an image process part. FIG. 5 is a diagram illustrating a configuration and operation of a reading conveyance unit when conveying a document. It is a figure which shows the structure and operation | movement of a reading conveyance part in the case of conveying a cleaning sheet. It is a flowchart which shows the main processes of an image reading apparatus. 3 is a flowchart showing an initial process of the image reading apparatus. 6 is a flowchart illustrating normal processing and cleaning processing of the image reading apparatus. It is a flowchart which shows the loop control in a cleaning process. It is a flowchart which shows the loop control in a cleaning process. It is a flowchart which shows the loop control in a cleaning process. It is a flowchart which shows the loop control in a cleaning process. It is a figure for demonstrating the range which performs loop control in a cleaning sheet.

Explanation of symbols

1 Image reading device 2 Scanner unit 3 ADF (automatic document feeder)
11 CCD (reading means)
13 Reading unit 21 Paper feeding unit (paper feeding roller)
41 ADFCPU (switching control means)
71 Pre-reading roller (front roller)
72 Roller after scanning (rear roller)
73 Conveyance guide 74 Step sheet (step member)
CS Cleaning sheet G Original

Claims (5)

A sheet-through type image reading device that reads an image of a document conveyed by an automatic document feeder through a reading unit to generate image data,
The automatic document feeder is provided with an upstream front roller and a downstream rear roller across the reading unit,
A discriminating means for discriminating whether a document is conveyed or a cleaning sheet is conveyed; and
When it is determined by the determining means that the document is conveyed by the automatic document feeder before reaching the front roller, the conveyance speed of the front roller is set to be equal to or less than the conveyance speed of the rear roller. so as not to contact with the document on the reading unit by and said when the cleaning sheet by the automatic document feeder is discriminated by the discriminating means before to be conveyed to reach the front roller, the front the conveying speed of the rollers faster than the transport speed of the rear roller by deflecting toward the cleaning sheet on the surface of the reading portion as you conveyed in a state in contact the cleaning sheet to the reading section There is no switching control means for switching the sheet passing state of the document or the cleaning sheet. ,
An image reading apparatus. A sheet-through type image reading device that reads an image of a document conveyed by an automatic document feeder through a reading unit to generate image data,
The automatic document feeder is provided with an upstream front roller and a downstream rear roller across the reading unit,
A discriminating means for discriminating whether a document is conveyed or a cleaning sheet is conveyed; and
When it is determined by the determining means that the document is conveyed by the automatic document feeder before reaching the front roller, the conveyance speed of the front roller is set to be equal to or less than the conveyance speed of the rear roller. When it is determined by the determining means that the document is not brought into contact with the reading unit and the cleaning sheet is conveyed by the automatic document feeder before reaching the front roller, the cleaning sheet is It is carried in a state where the cleaning sheet is brought into contact with the reading portion by deflecting the by Ri the cleaning sheet to the rear roller at which point the roller is stopped for a predetermined time towards the surface of the reading portion as that was switched to paper passing state of the document or the cleaning sheet Thus it provided the switching control means,
An image reading apparatus. A sheet-through type image reading device that reads an image of a document conveyed by an automatic document feeder through a reading unit to generate image data,
The automatic document feeder is provided with an upstream front roller and a downstream rear roller across the reading unit,
Determination means for determining whether the cleaning sheet document is conveyed is conveyed, and, pivotally disposed et Re read-position and possible transport switched between a cleaning position in the vicinity of the downstream side of the front roller A switching control means including a guide is provided,
The switching control means includes
When the discriminating means determines that the document is conveyed by the automatic document feeder before reaching the front roller, the document is brought into contact with the reading unit by switching the conveyance guide to the reading position. The cleaning sheet is switched to the cleaning position by switching the transport guide to the cleaning position when the determination means determines that the cleaning sheet is transported by the automatic document feeder until the front roller reaches the front roller. Switching the paper feeding state of the document or the cleaning sheet so that the cleaning sheet is conveyed in a state of being in contact with the reading unit by being bent toward the surface of the reading unit.
An image reading apparatus. A sheet-through type image reading device that reads an image of a document conveyed by an automatic document feeder through a reading unit to generate image data,
The automatic document feeder is provided with an upstream front roller and a downstream rear roller across the reading unit,
A discriminating means for discriminating whether a document is conveyed or a cleaning sheet is conveyed; and
And movably disposed et Re avoided position and switching control means which includes the step member can be switched between the retracted position are provided along the surface of the reading portion on the upstream side of the reading position,
The switching control means includes
When the determination means determines that the document is conveyed by the automatic document feeder before reaching the front roller, the document is brought into contact with the reading unit by switching the step member to the avoidance position. The cleaning sheet is switched to the retracted position by switching the step member to the retracted position when it is determined by the determining means that the cleaning sheet is conveyed by the automatic document feeder before reaching the front roller. Switching the paper feeding state of the document or the cleaning sheet so that the cleaning sheet is conveyed in a state of being in contact with the reading unit by being bent toward the surface of the reading unit.
An image reading apparatus. The front roller and the rear roller are arranged in a direction in which the document or the cleaning sheet can be bent toward the surface of the reading unit,
The image reading apparatus according to claim 1.

Images