JP4847384B2 - Image reading apparatus, image reading apparatus control method, and image reading apparatus control program - Google Patents

Description

  The present invention relates to an image reading apparatus that reads an image of a document conveyed on a conveyance path, a control method for the image reading apparatus, and a control program for the image reading apparatus.

  In the image reading apparatus, an image sensor that reads an image line by line by repeating scanning in the main scanning direction is fixedly arranged, and the document is conveyed on the contact glass and moved in the sub scanning direction with respect to the image sensor. There is a document conveyance type that reads an image.

  In a document conveyance type image reading apparatus, if there is dust, dirt or scratches on the document reading position on the contact glass, noise such as black streaks may occur in the read image, and a good image may not be acquired.

  In addition, it is ideal that the brightness of the illumination light corresponding to each pixel and the sensitivity of the light receiving element of the image sensor are constant, but in reality, the unevenness of the light quantity of the illumination light, distortion of the optical system, and the sensitivity of the light receiving element. Variations occur in the density of each pixel read due to the variation.

  Therefore, prior to starting the document image reading, the white reference plate is read to obtain shading correction data that is a collection of white level data for each pixel constituting one line of the image.

  By correcting the image data obtained by reading the document on a pixel basis with the acquired shading correction data as a reference, it is possible to read a good document image that is not affected by unevenness of illumination light or the like.

  However, if acquisition of shading correction data for performing such shading correction is performed in a state where the reading position on the contact glass has dust, dirt, or scratches, the original is read and the shading correction is performed on the read image. Noise such as white stripes may occur, and a good image may not be acquired.

On the other hand, as a technique for dealing with black streaks generated in the read original image, it is determined that black streaks occur when black pixels continuously exist in the sub-scanning direction at the same pixel position in the main scanning direction of the read image data. Those that issue warnings have been proposed (see Patent Document 1 and Patent Document 2).
JP-A-6-303428 JP-A-10-233875

  However, in Patent Document 1 and Patent Document 2 described above, when black pixels continuously exist in the sub-scanning direction at the same pixel position in the main scanning direction of the read image data, a black streak is determined and a warning is issued. It is not intended to prevent the occurrence of read image defects such as black streaks.

  Therefore, the present invention provides an image reading apparatus capable of reading a high-quality image even when dirt or dust adheres to the image reading position of the document in the image reading unit, or controls the image reading apparatus. It is an object to provide a method and a control program for an image reading apparatus.

To achieve the above object, an image reading apparatus of the present invention, a document passing detection sensor for detecting the document that will be conveyed along the conveying path, the image reading of the document based on the document passing detection sensor of the detection result An image reading sensor to be started, an image reading sensor moving unit that moves the image reading sensor along the conveyance path, and a dust detection unit that detects dust existing at a reading position where the image reading sensor can read an image. And storage means for temporarily storing the image data acquired based on the output of the image reading sensor, and reading means for reading the image data from the storage means , wherein the dust detection means is in a position where it does not detect dust. When the image reading sensor moving unit moves the image reading sensor so as to move the reading position, the reading position is moved according to the amount of movement of the reading position. Means and changes the read position of the image data stored in the storage means.

Method for controlling the image reading apparatus of the present invention, a document passing detection sensor for detecting the document that will be conveyed along the conveying path, the image reading image reading of the document is started on the basis of the document passing detection sensor of the detection result A sensor, an image reading sensor moving means for moving the image reading sensor along the conveyance path, a dust detecting means for detecting dust existing in a reading device where the image reading sensor can read an image, and the image reading upon controlling storage means for temporarily storing the image data acquired based on the output of the sensor, an image reading device provided with reading means for reading out image data from said storing means, said dust detecting means detects dust A step of moving the image reading sensor by the image reading sensor moving means so as to move the reading position to a position where the reading is not performed, and movement of the reading position Depending on, the reading unit is characterized by having the steps of: changing the read position of the image data stored in the storage means.

A control program of the image reading apparatus of the present invention, a document passing detection sensor for detecting the document that will be conveyed along the conveying path, the image reading image reading of the document is started on the basis of the document passing detection sensor of the detection result A sensor, an image reading sensor moving means for moving the image reading sensor along the conveyance path, a dust detecting means for detecting dust existing at a reading position where the image reading sensor can read an image, and the image reading The image reading apparatus is controlled from a computer connected to an image reading apparatus having a storage means for temporarily storing image data acquired based on the output of the sensor and a reading means for reading the image data from the storage means. per the, the dust detection means to move the reading position to a position that does not detect the dust, the image reading sensor moving means said image And moving the reading sensor, in accordance with the movement amount of the reading position, the reading means and characterized in that to execute a step of changing the read position of the image data stored in said storage means, to said computer To do.

  According to the present invention, a high-quality image can be read even if dirt, dust, or the like is attached to or scratched at the image reading position of the document in the image reading unit.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a perspective view showing a state in which an image reading apparatus according to a first embodiment of the present invention is connected to a host computer, and FIG. 2 is a schematic sectional view of the image reading apparatus according to the first embodiment of the present invention. is there.

  As shown in FIG. 1, the image reading apparatus 1 according to the present embodiment is connected to a host computer 2 via a SCSI (Small Computer System Interface) cable 3. The image reading device 1 reads an image of a document and transfers the read image data to the host computer 2 via the SCSI cable 3. The host computer 2 stores the image data transferred from the image reading device 1.

  As shown in FIG. 2, the image reading apparatus 1 includes a document table 201 on which documents 210 are stacked, a document detection sensor (not shown) that detects whether or not the document 210 is on the document table 201, a separation feed roller pair 202, A pair of conveyance rollers 203 to 206, an image reading unit 207, a scanner substrate 208, a pickup roller 209, a reference plate 211, and a document passage detection sensor 212 are provided.

  A contact glass 213 is disposed between the image reading unit 207 and the document conveyance path. The contact glass 213 may be fixed to the image reading unit 207, or may be provided independently of the image reading unit 207.

  A reference plate 211 is installed at a position opposite to the contact glass 213 across the conveyance path, and shading correction data is acquired by reading the reference plate 211 by the image reading unit 207 before conveying the document 210. Process.

  One surface of the reference plate 211 is a white portion that is substantially white (including chromatic white), and the other surface is a black portion that is substantially black (including chromatic black). The background color of the document can be switched when the image reading unit 207 reads the image of the document by the rotation operation. In addition, the reference | standard board 211 may provide a white part and a black part in the same surface instead of rotation, and may be translated along a conveyance path. Further, instead of the reference plate, a rotating member having a white region and a black region in the circumferential direction may be used.

  The pickup roller 209 and each of the roller pairs 202 to 206 convey the original 210, and when the original 210 passes the original passage detection sensor 212, the image reading unit 207 starts reading the image of the original 210.

  FIG. 3 is a block diagram for explaining a control system of the image reading apparatus 1 shown in FIG.

  As shown in FIG. 3, the image reading apparatus 1 includes a CPU 250 that controls the operation of the entire apparatus, a ROM 254 that stores a control program executed by the CPU 250, a RAM 253 that functions as a work memory, and a SCSI interface (I / F). ) 255.

  The CPU 250, ROM 254, RAM 253, and SCSI interface (I / F) 255 are connected to each other via a system bus 256. An image reading sensor 251 incorporated in the image reading unit 207 is connected to the system bus 256 via an image processing unit (not shown), and an image reading sensor moving unit 252 is connected.

  Image data read by the image reading sensor 251 and subjected to processing such as A / D conversion by an image processing unit (not shown) is sent to the system bus 256 and stored in the RAM 253, and at a predetermined timing, the SCSI interface (I / F ) 255 and the SCSI cable 3 to the host computer 2. The CPU 250 controls the operation of the image reading sensor moving unit 252 that moves the image reading sensor 251 via the system bus 256.

  FIG. 4 is a block diagram for explaining the internal configuration of the host computer 2.

  As shown in FIG. 4, the host computer 2 includes a CPU 301, a memory 303, and a hard disk 305. In addition, the host computer 2 includes a keyboard 302 and a display 304.

  The CPU 301 transmits and receives data to and from the image reading apparatus 1 via the SCSI interface 307 and the SCSI cable 3. The memory 303 stores control programs and image data temporarily. The hard disk 305 stores image data of a document read by the image reading unit 207 of the image reading apparatus 1. The keyboard 302 is used for performing an input operation by the user. The user uses the keyboard 302 to set document reading conditions and the like. On the display 304, an image of the document read by the image reading unit 207 of the image reading apparatus 1 is displayed.

  Next, an image reading operation of the image reading apparatus 1 will be described with reference to FIGS.

  As shown in FIG. 5, the image reading sensor 251 is in units of 0.1 mm by a stepping motor (not shown) that drives the image reading sensor moving unit 252 along the conveyance direction of the original 210 inside the contact glass 213. It is possible to move up to 10 mm.

  Before the original 210 is conveyed, the black reference surface of the reference plate 211 is opposed to the image reading sensor 251, and the black reference surface of the reference plate 211 is read by the image reading sensor 251. Subsequently, the reference plate 211 is rotated to face the white reference surface, and the white reference surface of the reference plate 211 is read by the image reading sensor 251.

  When the image reading sensor 251 reads the black reference surface and the white reference surface, the image reading sensor 251 reads the image up to a position where no abnormal value appears in the both reading results, that is, a position where there is no dust or scratch on the contact glass 213. It is moved by the sensor moving unit 252.

  As described above, it is preferable that both the black reference surface and the white reference surface are read by the image reading sensor 251 to detect dust or the like, but dust or the like is detected using one of the black reference surface and the white reference surface. If it can be detected, dust may be detected by reading one of the reference surfaces. For example, the black reference surface may be read when the dust is mainly white dust such as paper dust, and the white reference surface may be read when the dust is mainly black dirt.

  Shading correction data is acquired from the read data of the white reference plane at this time. Note that in order to perform more strict image correction processing, black level correction data may be acquired from black reference surface read data to perform black level correction. A determination method for finding a position free of dust and scratches on the contact glass 213 will be described later with reference to FIG.

  Next, when the original 210 is conveyed by the conveying rollers 202 and 203 and the original 210 passes the image reading start sensor 212, the image reading sensor 251 starts reading the image of the original. Then, shading correction is performed and temporarily stored in the RAM 253 (see FIG. 3).

  FIG. 6 is a diagram illustrating read image data temporarily stored in the RAM 253.

  An image 510 is illustrated as image data read by the image reading sensor 251 at the position “a” in FIG.

  An image 511 illustrates image data read by the image reading sensor 251 at the position “b” in FIG. 5.

  An image 512 shows the image data read by the image reading sensor 251 at the position “c” in FIG.

  The image data read by the image reading sensor 251 in the respective positions “a”, “b”, and “c” in FIG. 5 and stored in the RAM 253 has upper and lower margins (the portions represented by black in FIG. 6). However, the moving amount of the reading position (equal to the moving amount of the image reading sensor in this embodiment) can be found from the position information when the image reading sensor 251 reads.

  From this amount of movement, the document edge position of the image data temporarily stored in the RAM 253 is calculated, and the CPU 250 reads out the image data in the RAM 253 using the calculated document edge position as a starting point, and the SCSI interface (I / F). The data is transmitted to the host computer 2 via 255.

  Next, a method for calculating the document edge position and the number of bytes of image data will be described.

  First, the BPP value is obtained according to the image mode set by the user. BPP (bits per pixel) is the number of bits per pixel, and is 1 for black and white, 8 for gray, and 24 for color, for example.

  The calculation of the position (memory address) as the starting point for reading image data will be described.

  The amount of movement of the image reading sensor 251 with respect to the reference position (mm) × reading resolution (dpi) /25.4=A. Therefore, it is only necessary to start reading from the Ath line without reading from the 0th line to the A-1st line. It is assumed that the reading resolution is the same in the main scanning direction and the sub-scanning direction. If a fraction is left, it is rounded down to an integer.

  In order to calculate the memory address at which reading starts at this time, first, the number of bytes B per line is calculated. The number of read pixels per line of the reading sensor at the set reading resolution × BPP / 8 = B, and the number of bytes B per line of the read image data is obtained. If a fraction is given, round it up to an integer.

  Next, the memory top address is B × A line = C, the 0th byte to the (C-1) th byte are ignored, and reading is started from the Cth byte.

  Next, the number of lines to be read is calculated.

  Document length (mm) × reading resolution (dpi) /25.4=D, and it can be seen that it is sufficient to read data for D lines. If a fraction is left, it is rounded down to an integer.

  After obtaining the above conditions, calculate the number of bytes to be read.

  B × D = E bytes, and the total number of bytes of image data to be read is E bytes. Therefore, the data to be read from the RAM 253 is a total of E bytes starting from the C byte, and these are read and transmitted to the host computer 2 using the SCSI interface (I / F) 255.

  From the above calculation formula, when the read image data is 600 dpi, 8-bit gray, the reading position of the image reading sensor 251 is, for example, a position 2 mm from the document detection sensor 212, and the resolution at which reading is started is 600 dpi. Since 2 / 25.4 × 600≈47 lines (fractions are rounded down), the 0th line to the 46th line are blank portions, and the leading edge of the image data of the document is stored from the 47th line.

  When the number of read pixels when the image reading sensor 251 scans one line is 5500 pixels at a resolution of 600 dpi, 5500 × 8/8 = 5500 is the number of bytes of one line of the image, and the 47 × 5500 = 258500th byte, Start reading.

  When the length of the original is 300 mm, the length of the image data is 300 / 25.4 × 600≈7086 lines (rounded down) when the resolution is 600 dpi, and the output data is 5500 × 7086 = 38973000 bytes and the SCSI interface is read out. (I / F) 255 is used for transmission to the host computer 2.

  On the other hand, when the number of read pixels when the image reading sensor 251 scans one line is 2750 pixels at a resolution of 300 dpi, the position (memory address) at which reading is started is determined accordingly.

  As described above, the image of FIG. 7 is output in any case of FIG. 6 by adjusting the reading position according to the sensor position.

  FIG. 8 is a flowchart for explaining the process of moving the image reading sensor 251 to a position where there is no dust or scratch on the contact glass 213 by the image reading sensor moving unit 252. Each process in FIG. 8 is executed by the CPU 250 after the control program stored in the ROM 254 is loaded into the RAM 253.

  First, the image reading sensor 251 is returned to the initial position by the image reading sensor moving unit 252 (step S1002). Next, the reference plate 211 is rotated so that the surface facing the image reading sensor 251 is the black surface (step S1003).

  The image reading sensor 251 reads the black reference surface of the opposing reference plate 211 (step S1004). The image data representing the brightness of each pixel for one line obtained by reading the reference plate 211 is compared with a predetermined black threshold value (step S1005), and if there is a pixel whose brightness is higher than the predetermined black threshold value, Then, it is determined that the contact glass 213 has dust or scratches (step S1006), and the process proceeds to step S1007. The image data for one line at this time is as shown in FIG.

  In step S1007, the image reading sensor 251 is moved from the current reading position by the image reading sensor moving unit 252 within the movable range of the reference plate 211 (1007), and the process returns to step S1003.

  On the other hand, the image data representing the brightness of each pixel for one line obtained by reading the reference plate 211 is compared with a predetermined black threshold (step S1005), and all the pixels whose brightness is lower than the predetermined black threshold in step S1006. (If the output can be determined that there is no dust shown in FIG. 14), the process proceeds to step S1008, where the reference plate 211 is rotated so that the surface facing the image reading sensor 251 is the white surface.

  In step S <b> 1009, the image reading sensor 251 reads the white reference surface of the opposing reference plate 211. When the brightness level is compared with a predetermined white threshold for each pixel constituting the image data for one line obtained by reading the reference plate 211 (step S1010), and there is a pixel whose brightness is lower than the predetermined white threshold In (NO in step S1011), it is determined that the contact glass 213 has dust or scratches, and the process proceeds to step S1007. The image data for one line at this time is as shown in FIG.

  When the image data for one line obtained by reading the reference plate 211 becomes the output shown in FIG. 12 in step S1011, the process proceeds to step S1012, and finally for each pixel for one line obtained by reading the white reference plane. Image data obtained by reading the white reference plane at a reading position where all of the image data representing brightness is higher than the predetermined threshold is acquired as shading correction data.

  At this time, the reading position of the image reading sensor 251 moved by the image reading sensor moving unit 252 is set as an image reading position (step S1013).

  FIG. 9 is a flowchart for explaining processing for transmitting image data of a document read by the image reading sensor 251 to the host computer 2. Each process in FIG. 9 is executed by the CPU 250 after the control program stored in the ROM 254 is loaded into the RAM 253.

  First, the document 210 on the document table 201 is conveyed by the pickup roller 209 and each of the roller pairs 202 to 206 (step S2001), and the time when the leading edge of the document passes the document passage detection sensor 212 is used as a reference (step S2002). In 251, reading of an image of a document is started.

  The image data of the document read by the image reading sensor 251 is temporarily stored in the RAM 253 (step S2003), and the document trailing edge is the image reading unit 207 with reference to the time when the document trailing edge has passed the document passage detection sensor 212. Is estimated (step S2004), and the image reading sensor 251 finishes reading the image of the document at this estimated time.

  Since the image data stored in the RAM 253 has upper and lower margins, the original in the image data stored in the RAM 253 is based on the reading position of the image reading sensor 251 moved by the image reading sensor moving unit 252 by the method described above. The storage position of the part is calculated (step S2005), and the image data stored in the RAM 253 is read with the position where the original part of the image data is stored as the head address.

  Then, the image data read from the RAM 253 is transmitted to the host computer 2 via the SCSI interface (I / F) 255 and the SCSI cable 3 (step S2007).

  As described above, in the present embodiment, when shading correction is performed based on the shading correction data obtained by reading the white reference surface of the reference plate 211, dirt, dust, or the like adheres to the line at the image reading position. Even in this case, the position of the image reading sensor 251 can be moved to obtain good shading correction data, and image defects such as white stripes can be prevented from occurring in the read document image. The shading correction data may be acquired every time one or more originals are read. In this case, dust detection may be performed again.

  Further, even if there is dust, dirt or scratches on the reading line when reading an image of a document, the position of the image reading sensor 251 is moved to change the memory reading position of the image data. It is possible to read a good image without noise and with the margins before and after the image cut off.

  Next, an image reading apparatus according to a second embodiment of the present invention will be described with reference to FIGS. In addition, the same code | symbol is attached | subjected to a figure and the part which overlaps with the said 1st Embodiment, and the description is abbreviate | omitted.

  As shown in FIG. 10, the image reading device teeth of the present embodiment are connected to a system bus 256, which is a compression processing unit 700 that compresses image data.

  FIG. 11 is a flowchart for explaining processing for transmitting image data of a document read by the image reading sensor 251 to the host computer 2. Each process in FIG. 11 is executed by the CPU 250 after the control program stored in the ROM 254 is loaded into the RAM 253. Further, Step S2001 to Step S2006 in FIG. 11 are the same as the processing described in FIG. 9 in the first embodiment, and thus the description thereof is omitted.

  In step S3001, the compression processing unit 700 performs compression processing such as JPEG on the image data read from the RAM 253, and in step S3002, the compressed image data is converted to the host computer 2 via the SCSI interface (I / F) 255 and the SCSI cable 3. Send to.

  As described above, in the image reading apparatus having the compression processing unit 700, the image data is stored in the RAM 253 before the compression process is performed, and the image data stored in the storage position of the document portion of the image data is read from the RAM 253. After compression. The compression process may be performed by the CPU 250 by a control program.

  In the present embodiment, since the output data transfer time for one original can be reduced by adding a compression function, the number of originals that can be scanned in a certain time can be increased. Other configurations and operational effects are the same as those of the first embodiment.

  In addition, this invention is not limited to what was illustrated to the said embodiment, In the range which does not deviate from the summary of this invention, it can change suitably.

  The object of the present invention is achieved by executing the following processing. That is, a storage medium that records a program code of software that realizes the functions of the above-described embodiments is supplied to a system or apparatus, and a computer (or CPU, MPU, etc.) of the system or apparatus is stored in the storage medium. This is the process of reading the code.

  In this case, the program code itself read from the storage medium realizes the functions of the above-described embodiments, and the program code and the storage medium storing the program code constitute the present invention.

  Moreover, the following can be used as a storage medium for supplying the program code. For example, floppy (registered trademark) disk, hard disk, magneto-optical disk, CD-ROM, CD-R, CD-RW, DVD-ROM, DVD-RAM, DVD-RW, DVD + RW, magnetic tape, nonvolatile memory card, ROM or the like. Alternatively, the program code may be downloaded via a network.

  Further, the present invention includes a case where the function of the above-described embodiment is realized by executing the program code read by the computer. In addition, an OS (operating system) running on the computer performs part or all of the actual processing based on an instruction of the program code, and the functions of the above-described embodiments are realized by the processing. Is also included.

  Furthermore, a case where the functions of the above-described embodiment are realized by the following processing is also included in the present invention. That is, the program code read from the storage medium is written in a memory provided in a function expansion board inserted into the computer or a function expansion unit connected to the computer. Thereafter, based on the instruction of the program code, the CPU or the like provided in the function expansion board or function expansion unit performs part or all of the actual processing.

1 is a perspective view showing a state in which an image reading apparatus according to a first embodiment of the present invention is connected to a host computer. It is a schematic sectional drawing of an image reading apparatus. It is a block diagram for demonstrating the control system of an image reading apparatus. It is a block diagram for demonstrating the internal structure of a host computer. It is explanatory drawing for demonstrating the image reading operation | movement of an image reading apparatus. It is a figure which shows the read image data temporarily stored in RAM. It is a figure which shows the example of an output image. FIG. 10 is a flowchart for explaining processing for moving the image reading sensor to a position free of dust and scratches on the contact glass by the image reading sensor moving unit. FIG. 6 is a flowchart for explaining processing for transmitting image data of a document read by an image reading sensor to a host computer. It is a block diagram for demonstrating the control system of the image reading apparatus which is the 2nd Embodiment of this invention. FIG. 6 is a flowchart for explaining processing for transmitting image data of a document read by an image reading sensor to a host computer. It is a graph which shows the white output data of a normal range. It is a graph which shows white output data when there exists dust and dirt. It is a graph which shows the black output data of a normal range. It is a graph which shows black output data when there exists dust and dirt.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Image reading apparatus 2 Host computer 3 SCSI cable 201 Document stand 202 Separation feeding roller pair 203 Conveying roller pair 204 Conveying roller pair 205 Conveying roller pair 206 Conveying roller pair 207 Image reading unit 208 Scanner substrate 209 Pickup roller 210 Document 211 Reference plate (Reference material)
212 Document passage detection sensor 213 Contact glass 250 CPU (dust detection means, reading means, setting means)
251 Image reading sensor 252 Image reading sensor moving unit (image reading sensor moving means)
253 RAM (storage means)
254 ROM
255 SCSI interface 256 System bus 301 Host computer CPU
302 Keyboard 303 Host computer memory 304 Display 305 Hard disk 307 SCSI interface 700 Compression processing unit (compression means)

Claims (8)

A document passing detection sensor for detecting the document that will be conveyed along the conveying path,
An image reading sensor for starting image reading of a document based on a detection result of the document passage detection sensor ;
Image reading sensor moving means for moving the image reading sensor along the conveyance path ;
Dust detection means for detecting dust present at a reading position where the image reading sensor can read an image;
Storage means for temporarily storing image data acquired based on the output of the image reading sensor;
Reading means for reading image data from the storage means ,
When the image reading sensor moving means moves the image reading sensor so that the dust detecting means moves the reading position to a position where dust is not detected, the reading means is determined according to the amount of movement of the reading position. And changing the reading position of the image data stored in the storage means.   The dust detection means is configured to detect dust at the reading position based on an output signal that the image reading sensor reads and outputs a reference member installed at a position facing the image reading sensor across the conveyance path. The image reading apparatus according to claim 1, wherein:   The reference member has a substantially white white reference surface and a substantially black black reference surface, and the dust detection means outputs an output signal when the image reading sensor reads the white reference surface, and the image reading sensor. 3. The image reading apparatus according to claim 2, wherein dust at the reading position is detected based on at least one of output signals when reading the black reference surface. The reference member has a substantially white white reference surface and a substantially black black reference surface, and the dust detection means outputs an output signal when the image reading sensor reads the white reference surface, and the image reading sensor. The image reading apparatus according to claim 2, wherein dust is detected at the reading position based on an output signal when reading the black reference plane . 2. A setting unit for setting a reading resolution is provided, and a reading position for reading image data from the storage unit is changed in accordance with a moving amount of the reading position and the set reading resolution. The image reading apparatus according to any one of? The image reading apparatus according to claim 1, further comprising a compression unit that compresses image data read from the storage unit . A document passing detection sensor for detecting the document that will be conveyed along the conveying path, and an image reading sensor which image reading of the document is started on the basis of the document passing detection sensor of the detection result, the conveyance path of the image reading sensor an image reading sensor moving unit that moves along the dust detection means for the image reading sensor detects dust present in possible reading location to read an image, the image data obtained on the basis of the output of the image reading sensor When controlling an image reading apparatus comprising a storage means for temporarily storing and a reading means for reading out image data from the storage means ,
The image reading sensor moving means moving the image reading sensor so that the dust detecting means moves the reading position to a position where no dust is detected;
And a step of changing the reading position of the image data stored in the storage means in accordance with the amount of movement of the reading position. A document passing detection sensor for detecting the document that will be conveyed along the conveying path, and an image reading sensor which image reading of the document is started on the basis of the document passing detection sensor of the detection result, the conveyance path of the image reading sensor an image reading sensor moving unit that moves along the dust detection means for the image reading sensor detects dust present in readable reading position an image, the image data obtained on the basis of the output of the image reading sensor In controlling the image reading apparatus from a computer connected to an image reading apparatus provided with a storage means for temporarily storing and a reading means for reading out image data from the storage means ,
The image reading sensor moving means moving the image reading sensor so that the dust detecting means moves the reading position to a position where no dust is detected;
Depending on the amount of movement of the reading position, the reading unit is an image reading apparatus control program, characterized in that to execute a step of changing the read position of the image data stored in the storage unit to the computer.

Images