JP2017163453A - Image reading device and image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To acquire black reference data at an appropriate timing.SOLUTION: An image forming apparatus 100 comprises: an image reading unit 2; a white reference acquisition part 55; a black reference acquisition part 56; and an acquisition instruction part 54. The image reading unit 2 reads an image of a document. The white reference acquisition part 55 acquires white reference data DW in an inter-sheet time TV. The black reference acquisition part 56 acquires black reference data in the inter-sheet time TV. The acquisition instruction part 54 instructs the white reference acquisition part 55 to acquire the white reference data DW on the basis of the inter-sheet time TV. The acquisition instruction part 54 instructs the black reference acquisition part 56 to acquire the black reference data DK on the basis of the inter-sheet time TV. The inter-sheet time TV indicates a time from when the time point at which the rear end in a conveyance direction of the document passes through a reading position 211a to when the leading end in the conveyance direction of a subsequent document passes through the reading position 211a.SELECTED DRAWING: Figure 3

Description

  The present invention relates to an image reading apparatus and an image forming apparatus.

  In general, an image reading apparatus that reads an image formed on a document is known. Various techniques for acquiring white reference data and black reference data in an image reading apparatus are known.

  Patent Document 1 describes an image reading apparatus that acquires white reference data and black reference data. The image reading apparatus includes an image reading unit, a white reference plate, a paper dust removing plate, a white reference data acquisition unit, and a black reference data acquisition unit. The paper dust removing plate has a black surface. The image reading unit generates a document image. The white reference data acquisition unit acquires white reference data, and the black reference data acquisition unit acquires black reference data. Specifically, the image reading unit reads an image of the white reference plate irradiated with light, and the white reference data acquisition unit acquires white reference data based on the read image. In addition, the image reading unit reads an image of the black surface irradiated with light, and the black reference data acquisition unit acquires black reference data based on the read image. Therefore, the shading correction of the document image can be performed based on the white reference data and the black reference data. Therefore, the image quality of the original image can be improved.

JP 2013-110453 A

  However, since the image reading apparatus described in Patent Document 1 acquires the white reference data and the black reference data before reading the document image, the image quality of the document may be deteriorated. For example, when reading a document continuously, the temperature of the image reading unit rises, so that the white reference data and the black reference data change. Therefore, if the original image acquired after the temperature rises is subjected to shading correction with the white reference data and the black reference data acquired before the original image is read, the image quality of the original image may be lowered.

  SUMMARY An advantage of some aspects of the invention is that it provides an image reading apparatus and an image forming apparatus that can acquire white reference data and black reference data at an appropriate timing.

  The image reading apparatus of the present invention includes an image reading unit, a white reference acquisition unit, a black reference acquisition unit, and an acquisition instruction unit. The image reading unit reads an image of a document. The white reference acquisition unit acquires white reference data at document intervals. The black reference acquisition unit acquires black reference data at the document interval. The acquisition instructing unit instructs the white reference acquiring unit to acquire the white reference data based on the document interval. The acquisition instruction unit instructs the black reference acquisition unit to acquire the black reference data based on the document interval. The document interval indicates an interval from the time when the trailing edge of the document in the conveying direction passes the image reading position to the time when the leading edge of the succeeding document in the conveying direction passes the image reading position. The image reading position indicates the position of the document when the image reading unit reads the image of the document.

  The image forming apparatus of the present invention includes an image forming unit and the image reading device. The image forming unit forms an image on a recording medium.

  According to the image reading apparatus and the image forming apparatus of the present invention, white reference data and black reference data can be acquired at an appropriate timing.

1 is a diagram illustrating a configuration of an image forming apparatus according to an embodiment of the present invention. FIG. 3 is a diagram illustrating a configuration of an image reading unit and a document transport unit. It is a figure which shows the structure of a control part. It is a flowchart which shows operation | movement of a control part. It is a flowchart which shows the operation | movement in the reference | standard acquisition process of a control part.

  Embodiments of the present invention will be described below with reference to the drawings (FIGS. 1 to 5). In the drawings, the same or corresponding parts are denoted by the same reference numerals and description thereof is not repeated.

  First, an image forming apparatus 100 according to the present embodiment will be described with reference to FIG. The image forming apparatus 100 is a multifunction machine. The image forming apparatus 100 includes an image forming unit 1, an image reading unit 2, and a document conveying unit 3.

  The image forming unit 1 forms an image on a sheet P that is an example of a recording medium. The image reading unit 2 reads an image formed on the front surface and the back surface of the document R. Further, the image reading unit 2 includes a control unit 5. The document transport unit 3 supplies the document R to the image reading unit 2 and reads an image formed on the back surface of the document R. The control unit 5 controls the operation of the image forming apparatus 100.

  The image forming unit 1 also includes a paper feed cassette 11, a transport roller pair 12, an image forming unit 13, a fixing device 14, a discharge roller pair 15, and a discharge tray 16. The paper P fed out from the paper feed cassette 11 is transported to the image forming unit 13 by the transport roller pair 12.

  The image forming unit 13 forms an image on the paper P. The paper P on which the image is formed is conveyed to the fixing device 14. The fixing device 14 fixes the image formed on the paper P onto the paper P. The paper P on which the image is fixed is discharged to the discharge tray 16 by the discharge roller pair 15.

  Next, the image reading unit 2 and the document transport unit 3 will be described with reference to FIG. As shown in FIG. 2, the image reading unit 2 includes a contact glass 210, a scanning unit 22, and a rail member 23. The scanning unit 22 includes a first image reading unit 221 and a carriage 222. The first image reading unit 221 is a CIS (Contact Image Sensor) unit that includes an LED (Light Emitting Diode), a contact glass, an imaging lens, and an image sensor, and these members are integrated. The carriage 222 is formed integrally with the first image reading unit 221. The rail member 23 extends in the sub-scanning direction and supports the carriage 222 so as to be movable. The contact glass 210 includes a document placement glass 212 and a document automatic reading glass 211.

  There are two types of image reading methods of the document R by the image reading unit 2, that is, a flat bed reading mode and an ADF (Auto Document Feeder) reading mode. In the flat bed reading mode, the image of the document R placed on the document placement glass 212 is read. In the ADF reading mode, the original R is conveyed by the original conveying unit 3, and when the original R passes the reading position 211a, an image on the surface of the original R is read. In the following description, a case where the image reading unit 2 reads an image of the document R placed on the document tray 31 in the ADF reading mode will be described.

  Specifically, in the ADF reading mode, when the document R passes the reading position 211a, the first image reading unit 221 continuously reads an image on the surface of the document R and generates image data.

  The document transport unit 3 includes a document tray 31, a pickup roller 32, a paper feed unit 33, a transport roller pair 34, a registration roller pair 341, a second image reading unit 351, a white reference roller 352, a transport roller pair 35, a reading guide 36, A conveyance roller pair 37, a discharge roller pair 38, and a document discharge tray 39 are provided. The document transport unit 3 constitutes an ADF.

  A plurality of documents R (see FIG. 1) are placed on the document tray 31. The pickup roller 32 feeds the uppermost document R out of the plurality of documents R one by one toward the sheet feeding unit 33. The pickup roller 32 starts feeding the next document R after a predetermined paper interval time TV (document spacing) has elapsed since the trailing edge of the document R has been fed. The paper feed unit 33 includes a driven roller 331, a drive roller 332, a tension adjustment roller 333, a paper feed belt 334, and a separation roller 335.

  The second image reading unit 351 is a CIS unit including an LED, a contact glass, an imaging lens, and an image sensor 351a, and these members are integrated. The second image reading unit 351 reads an image on the back side of the document R.

  The image reading unit 2 and the document conveying unit 3 correspond to an “image reading device”. The inter-paper time TV corresponds to an example of “original space”. The inter-paper time TV indicates the time from the time when the trailing edge of the document R in the transport direction passes through the reading position 211a to the time when the leading edge of the subsequent document R in the transport direction passes through the reading position 211a. The reading position 211a corresponds to an example of “original reading position”.

  Next, the configuration of the control unit 5 according to the present embodiment will be described with reference to FIG. The control unit 5 includes a processor such as a CPU (Central Processing Unit) and a memory such as a semiconductor memory. A control program is stored in the memory. The processor functions as various functional units by executing the control program. As a result, the various functional units of the processor control the operation of the image forming apparatus 100. As illustrated in FIG. 3, the control unit 5 includes a control determination unit 51, a frequency determination unit 52, a time determination unit 53, an acquisition instruction unit 54, a white reference acquisition unit 55, and a black reference acquisition unit 56.

  The control determination unit 51 determines whether or not to perform correction control in the inter-sheet time TV. The correction control includes control for changing a condition for the image reading unit 2 to acquire an image when the image acquired by the image reading unit 2 has an abnormality including dirt. Specifically, the correction control changes the position (the position in the Y direction in FIG. 2) at which the image reading unit 2 acquires an image when dirt is adhered to the automatic document reading glass 211.

  The number determination unit 52 determines whether or not the control determination unit 51 has determined NS for a predetermined number of times to perform correction control. The predetermined number NS is, for example, three times.

  The time determination unit 53 determines whether or not the paper interval time TV is less than the predetermined time TS. The predetermined time TS indicates a time during which the white reference data DW and the black reference data DK can be acquired. Specifically, the predetermined time TS is equal to or greater than the sum of the time required for the white reference acquisition unit 55 to acquire the white reference data DW and the time required for the black reference acquisition unit 56 to acquire the black reference data DK. Determined. The predetermined time TS is, for example, 500 msec. The time required for the white reference acquisition unit 55 to acquire the white reference data DW is, for example, 250 msec, and the time required for the black reference acquisition unit 56 to acquire the black reference data DK is, for example, 250 msec.

  The acquisition instruction unit 54 instructs the white reference acquisition unit 55 to acquire the white reference data DW when the time determination unit 53 determines that the paper interval time TV is less than the predetermined time TS, or The black reference acquisition unit 56 is instructed to acquire the black reference data DK. Specifically, when the time determination unit 53 determines that the paper interval time TV is less than the predetermined time TS, the acquisition instruction unit 54 sends the white reference data DW to the white reference acquisition unit 55. An instruction and an instruction to the black reference acquisition unit 56 for acquiring the black reference data DK are alternately output.

  The acquisition instruction unit 54 instructs the white reference acquisition unit 55 to acquire the white reference data DW when the time determination unit 53 determines that the paper interval time TV is not less than the predetermined time TS. The black reference acquisition unit 56 is instructed to acquire the black reference data DK.

  The white reference acquisition unit 55 acquires white reference data DW. Specifically, the white reference acquisition unit 55 acquires the white reference data DW by acquiring light amount data input to the image sensor of the first image reading unit 221 with the LED turned on. The white reference data DW is used for shading correction of the document image.

  The black reference acquisition unit 56 acquires black reference data DK. Specifically, the black reference acquisition unit 56 acquires the black reference data DK by acquiring light amount data input to the image sensor of the first image reading unit 221 with the LED turned off. The black reference data DK is used for shading correction of the document image.

  Next, the operation of the control unit 5 will be described with reference to FIG. As shown in FIG. 4, first, in step S101, the document transport unit 3 starts feeding. Next, in step S103, the control determination unit 51 determines whether or not to perform correction control during the inter-sheet time TV. If it is determined that correction control is to be performed during the paper interval TV (YES in step S103), the process proceeds to step S109. If it is determined that correction control is not performed during the inter-paper time TV (NO in step S103), the process proceeds to step S105. In step S105, the “reference acquisition process” is executed. The “reference acquisition process” is a process in which the white reference acquisition unit 55 acquires the white reference data DW and the black reference acquisition unit 56 acquires the black reference data DK in accordance with an instruction from the acquisition instruction unit 54. When the “reference acquisition process” ends, the process proceeds to step S107. In step S107, the number determination unit 52 initializes the value of the counter N to zero (zero), and the process proceeds to step S111. The counter N counts the number of times that the correction control is continuously performed.

  If YES in step S103, the number determination unit 52 increments the value of the counter N by 1 in step S109. In addition, the acquisition instruction unit 54 instructs the white reference acquisition unit 55 not to acquire the white reference data DW and also instructs the black reference acquisition unit 56 not to acquire the black reference data DK. Then, the process proceeds to step S111. Next, in step S111, the number determination unit 52 determines whether or not the value of the counter N is equal to or greater than the predetermined number NS.

  If it is determined that the predetermined number of times is not greater than NS (NO in step S111), the process proceeds to step S121. If it is determined that the number is equal to or greater than the predetermined number NS (YES in step S111), the process proceeds to step S113. In step S113, the acquisition instruction unit 54 instructs the document transport unit 3 to stop transporting the document R. Then, the document conveying unit 3 stops conveying the document R. Next, in step S115, the acquisition instruction unit 54 instructs the white reference acquisition unit 55 to acquire the white reference data DW and also instructs the black reference acquisition unit 56 to acquire the black reference data DK. The white reference acquisition unit 55 acquires the white reference data DW, and the black reference acquisition unit 56 acquires the black reference data DK. Next, in step S117, the document transport unit 3 is instructed to start transporting the document R. Then, the document transport unit 3 starts transporting the document R. Next, in step S119, the number determination unit 52 initializes the value of the counter N to zero (zero), and the process proceeds to step S121.

  If NO in step S111, or if the process of step S119 ends, in step S121, the control unit 5 determines whether or not to continue the conveyance of the document R. Specifically, the control unit 5 determines that the conveyance of the document R is continued when the document R remains on the document tray 31. On the other hand, when the document R does not remain on the document tray 31, the control unit 5 determines that the conveyance of the document R is not continued. If it is determined that the conveyance of the document R is to be continued (YES in step S121), the process returns to step S103. If it is determined not to continue transporting the document R (NO in step S121), the process ends.

  As described in step S103 and step S109, when the control determination unit 51 determines that correction control is to be performed, the acquisition instruction unit 54 performs the following processing. That is, the acquisition instruction unit 54 instructs the white reference acquisition unit 55 not to acquire the white reference data DW, and also instructs the black reference acquisition unit 56 not to acquire the black reference data DK.

  As described in steps S111 to S115, when the control determination unit 51 determines to perform correction control a predetermined number of times NS continuously, the acquisition instruction unit 54 performs the following processing. That is, the document transport unit 3 is instructed to stop transporting the document R, the white reference acquisition unit 55 is instructed to acquire the white reference data DW, and the black reference acquisition is performed to acquire the black reference data DK. The unit 56 is instructed.

  Next, the “reference acquisition process” will be described with reference to FIG. The “reference acquisition process” is executed in step S105 of FIG. As shown in FIG. 5, first, in step S201, the time determination unit 53 determines whether or not the paper interval time TV is less than the predetermined time TS. If it is determined that the paper interval time TV is less than the predetermined time TS (YES in step S201), the process proceeds to step S207. If it is determined that the inter-paper time TV is not less than the predetermined time TS (NO in step S201), the process proceeds to step S203. In step S203, the acquisition instruction unit 54 instructs the black reference acquisition unit 56 to acquire the black reference data DK. Then, the black reference acquisition unit 56 acquires the black reference data DK, and the process proceeds to step S205. Next, in step S205, the acquisition instruction unit 54 instructs the white reference acquisition unit 55 to acquire the white reference data DW. Then, the white reference acquisition unit 55 acquires the white reference data DW, and the process proceeds to step S111 in FIG.

  If YES in step S201 of FIG. 5, in step S207, the acquisition instruction unit 54 determines whether or not the read number NR of the document R indicates an odd number. If it is determined that the read number NR indicates an odd number (YES in step S207), the process proceeds to step S211. If it is determined that the read number NR does not indicate an odd number (NO in step S207), the process proceeds to step S209. In step S209, the acquisition instruction unit 54 instructs the white reference acquisition unit 55 to acquire the white reference data DW. Then, the white reference acquisition unit 55 acquires the white reference data DW, and the process proceeds to step S111 in FIG.

  If YES in step S207 of FIG. 5, in step S211, the acquisition instruction unit 54 instructs the black reference acquisition unit 56 to acquire the black reference data DK. Then, the black reference acquisition unit 56 acquires the black reference data DK, and the process proceeds to step S111 in FIG.

  As described above with reference to FIGS. 1 to 5, the acquisition instruction unit 54 instructs the white reference acquisition unit 55 to acquire the white reference data DW based on the paper interval time TV, and sets the paper interval time. The black reference acquisition unit 56 is instructed to acquire the black reference data DK based on the TV. Therefore, for example, when the paper interval time TV is long, the white reference data DW and the black reference data DK can be acquired. On the other hand, when the paper interval time TV is short, the white reference data DW or the black reference data DK can be acquired. Therefore, the white reference data DW and the black reference data DK can be acquired at an appropriate timing.

  The inter-paper time TV indicates the time from the time when the trailing edge of the document R in the transport direction passes through the reading position 211a to the time when the leading edge of the subsequent document R in the transport direction passes through the reading position 211a. Therefore, the acquisition instruction unit 54 can accurately determine whether or not both the white reference data DW and the black reference data DK can be acquired.

  Further, when the time determination unit 53 determines that the paper interval time TV is less than the predetermined time TS, the acquisition instruction unit 54 instructs the white reference acquisition unit 55 to acquire the white reference data DW, Alternatively, the black reference acquisition unit 56 is instructed to acquire the black reference data DK. Therefore, the white reference data DW or the black reference data DK can be acquired. On the other hand, when the time determination unit 53 determines that the inter-paper time TV is not less than the predetermined time TS, the white reference acquisition unit 55 is instructed to acquire the white reference data DW and the black reference data DK is acquired. The black reference acquisition unit 56 is instructed to do so. Therefore, the white reference data DW and the black reference data DK can be acquired. Therefore, the white reference data DW and the black reference data DK can be acquired at a more appropriate timing.

  In addition, the predetermined time TS is set to be equal to or more than the sum of the time required for the white reference acquisition unit 55 to acquire the white reference data DW and the time required for the black reference acquisition unit 56 to acquire the black reference data DK. It is done. Accordingly, it is possible to appropriately determine whether to acquire the white reference data DW or the black reference data DK, or to acquire the white reference data DW and the black reference data DK.

  When the time determination unit 53 determines that the paper interval time TV is less than the predetermined time TS, the acquisition instruction unit 54 instructs the white reference acquisition unit 55 to acquire the white reference data DW; An instruction to the black reference acquisition unit 56 for acquiring the black reference data DK is alternately output. Therefore, the white reference data DW and the black reference data DK can be obtained alternately. Therefore, the white reference data DW and the black reference data DK can be acquired at a more appropriate timing.

  Further, when the control determination unit 51 determines that correction control is performed in the inter-paper time TV, the acquisition instruction unit 54 instructs the white reference acquisition unit 55 not to acquire the white reference data DW, and the black reference. The black reference acquisition unit 56 is instructed not to acquire the data DK. When correction control is performed during the inter-paper time TV, the time for acquiring the white reference data DW or the black reference data DK is insufficient. Therefore, the white reference data DW and the black reference data DK can be acquired at a more appropriate timing.

  In addition, when the number determination unit 52 determines that the correction control is to be performed NS for a predetermined number of times, the acquisition instruction unit 54 performs the following processing. That is, the acquisition instruction unit 54 instructs the document conveyance unit 3 to stop the conveyance of the document R, instructs the white reference acquisition unit 55 to acquire the white reference data DW, and acquires the black reference data DK. The black reference acquisition unit 56 is instructed to do so. Therefore, the white reference data DW and the black reference data DK can be acquired. Therefore, the white reference data DW and the black reference data DK can be acquired at a more appropriate timing. Further, it is possible to suppress the deterioration of the quality of the document image.

  The embodiments of the present invention have been described above with reference to the drawings. However, the present invention is not limited to the above-described embodiment, and can be implemented in various modes without departing from the gist thereof (for example, (1) to (5) shown below). For ease of understanding, the drawings schematically show each component as a main component, and the thickness, length, number, etc. of each component shown in the drawings are different from the actual for convenience of drawing. There is a case. Moreover, the shape, dimension, etc. of each component shown by said embodiment are an example, Comprising: It does not specifically limit, A various change is possible in the range which does not deviate substantially from the structure of this invention.

  (1) The form in which “document interval” indicates time has been described with reference to FIG. 2, but is not limited thereto. The “document interval” may indicate the distance. More specifically, the “document interval” is determined from the time when the trailing edge of the document R in the transport direction passes the reading position 211a to the time when the leading edge of the subsequent document R in the transport direction passes the reading position 211a. The form which shows a conveyance distance may be sufficient.

  (2) The mode in which the white reference data DW and the black reference data DK are alternately obtained when the paper interval time TV is less than the predetermined time TS has been described with reference to FIGS. It is not limited to. Any form may be used as long as the white reference data DW or the black reference data DK is acquired. For example, every time the black reference data DK is acquired twice, the white reference data DW may be acquired once.

  (3) The embodiment in which the predetermined number NS is a fixed number (for example, three times) has been described with reference to FIGS. 3 to 5, but is not limited thereto. For example, the NS may be determined a predetermined number of times based on the resolution of the read image. Specifically, since the required image quality is higher as the resolution of the read image is higher, it is preferable to reduce NS a predetermined number of times.

  (4) With reference to FIG. 3 to FIG. 5, the correction control is control for changing the condition for the image reading unit 2 to acquire an image when the image acquired by the image reading unit 2 has an abnormality including dirt. Although the form has been described, the present invention is not limited to this. The correction control may be control performed in the inter-paper time TV.

  (5) Although the control part 5 demonstrated the form which acquires the white reference data DW and the black reference data DK of the image reading unit 2 with reference to FIGS. 2-5, it is not limited to this. The controller 5 may acquire the white reference data and the black reference data of the second image reading unit 351. In this case, the paper interval time TV is a position where the leading edge in the transport direction of the subsequent document R faces the image sensor 351a from the time when the trailing edge in the transport direction of the document R passes the position facing the image sensor 351a. Indicates the time to pass.

  The present invention can be used for an image reading apparatus and an image forming apparatus.

DESCRIPTION OF SYMBOLS 100 Image forming apparatus 1 Image forming unit 13 Image forming part 2 Image reading unit (a part of image reading apparatus)
210 Contact glass 211a Reading position (original reading position)
22 Scanning Unit 221 First Image Reading Unit (Image Reading Unit)
3 Document transport unit (document transport unit, part of image reader)
31 Document tray 351 Second image reading unit 351a Image sensor 5 Control unit 51 Control determination unit 52 Count determination unit 53 Time determination unit 54 Acquisition instruction unit 55 White reference acquisition unit 56 Black reference acquisition unit DW White reference data DK Black reference data TV Paper interval (document interval)

Claims (8)

An image reading unit for reading an image of a document;
A white reference acquisition unit that acquires white reference data at document intervals;
A black reference acquisition unit for acquiring black reference data in the document interval;
An acquisition instruction unit that instructs the white reference acquisition unit to acquire the white reference data based on the document interval;
The acquisition instruction unit instructs the black reference acquisition unit to acquire the black reference data based on the document interval,
The document interval indicates an interval from the time when the trailing edge of the document in the conveyance direction passes through the image reading position to the time when the leading edge of the subsequent document in the conveyance direction passes through the image reading position,
The image reading device, wherein the image reading position indicates a position of the original when the image reading unit reads an image of the original.   2. The document interval is a time period from a time point when a trailing end of the document in the transport direction passes through the image reading position to a time point when a leading end of the subsequent document in the transport direction passes through the image reading position. The image reading apparatus described in 1. A time determination unit for determining whether the document interval is less than a predetermined time;
The acquisition instruction unit
When the time determination unit determines that the document interval is less than the predetermined time, the white reference acquisition unit is instructed to acquire the white reference data, or the black reference data is acquired. Instruct the black reference acquisition unit to
When the time determination unit determines that the document interval is not less than the predetermined time, the white reference acquisition unit is instructed to acquire the white reference data, and the black reference data is acquired. The image reading apparatus according to claim 2, wherein an instruction is given to the black reference acquisition unit.   The predetermined time is determined to be equal to or more than a sum of a time required for the white reference acquisition unit to acquire the white reference data and a time required for the black reference acquisition unit to acquire the black reference data. Item 4. The image reading apparatus according to Item 3.   When the time determination unit determines that the document interval is less than the predetermined time, the acquisition instruction unit includes an instruction to the white reference acquisition unit to acquire the white reference data, and the black reference The image reading apparatus according to claim 3 or 4, wherein an instruction to the black reference acquisition unit to acquire data is alternately output. A control determination unit for determining whether to perform correction control in the document interval;
When the control determination unit determines that the correction control is performed, the acquisition instruction unit instructs the white reference acquisition unit not to acquire the white reference data and does not acquire the black reference data. To the black reference acquisition unit,
6. The correction control according to claim 1, wherein the correction control includes control for changing a condition for the image reading unit to acquire an image when the image acquired by the image reading unit includes an abnormality including dirt. 2. An image reading apparatus according to item 1. A document transport section for transporting the document;
A frequency determination unit that determines whether or not the control determination unit continuously determines a predetermined number of times to perform the correction control;
When the number determination unit determines that the predetermined number of times has been continuously determined, the acquisition instruction unit instructs the document conveyance unit to stop conveyance of the document, and acquires the white reference data. The image reading apparatus according to claim 6, wherein the black reference acquisition unit is instructed to acquire the black reference data at the same time. An image forming unit for forming an image on a recording medium;
An image forming apparatus comprising: the image reading apparatus according to claim 1.

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