JP5842499B2 - Image reading apparatus, image forming apparatus, and image reading program - Google Patents

Description

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

  Conventionally, the image processing unit generates shading data from the reference data based on the reflected light from the back plate acquired by the image reading unit, and the first control unit is included in the white reference data acquired by the image reading unit from the shading data. Threshold value data for determining whether or not each pixel value includes dirt, and compares the threshold data with the white reference data to determine whether or not each pixel value includes dirt. There has been proposed an image reading apparatus that outputs a warning message from a speaker when a certain number of stains is detected and the number of warnings that has been set in advance is detected (see, for example, Patent Document 1).

JP 2006-253964 A

  The present invention eliminates the inconvenience that even if the reading surface and the reference plate of the reading unit are cleaned, it is continuously informed that at least one of the reading surface and the reference plate of the reading unit is contaminated. An object is to provide an apparatus, an image forming apparatus, and an image reading program.

  In order to achieve the above object, an image reading apparatus according to the present invention is fixedly arranged facing a reading position, reads a document conveyed to the reading position, and a reference plate arranged at the reading position, and reads it. Based on reading means for outputting information, reading information output by reading the reference plate with the reading means, and reference information acquired in advance, the reading surface of the reading means and at least one of the reference plate are soiled A calculation means for calculating a detection value for detecting whether or not there is a detection value, and a detection value calculated by the calculation means is not less than a first threshold value for determining whether or not the dirt exists, and A determination unit that determines whether the detection value is a value within a range that is greater than the first threshold value and less than or equal to a second threshold value for determining whether or not the detection value is abnormal; The value is determined to be within the range. If the, it is configured to include a and informing means for informing that at least one dirt of the reading surface and the reference plate of the reading means is present.

  The determination means further determines whether or not the detection value is a value exceeding the second threshold, and when the determination means determines that the detection value is a value exceeding the second threshold In addition, the control unit may be configured to control so that an initialization process for eliminating the abnormality of the detected value is executed.

  In addition, when the determination unit determines that the detection value exceeds the second threshold, the control unit calculates the detection value by the calculation unit until the initialization process is executed. And it can control so that the determination by the said determination means is not performed.

  In addition, when it is recognized that at least one of the reading surface of the reading unit and the reference plate has been cleaned, the calculation of the detection value by the calculation unit and the determination by the determination unit can be performed. .

  In addition, after the original is read by the reading unit, the detection value can be calculated by the calculation unit and the determination can be performed by the determination unit.

  The reading unit may be a reading unit for back side reading used when performing double-sided reading of the document.

  In addition, after the reading unit performs the back side reading in the double-sided reading of the document, the detection value can be calculated by the calculation unit and the determination by the determination unit can be performed.

  The control unit may execute the initialization process before executing double-sided reading of the document.

  In addition, the notification unit can notify an abnormality when the determination unit determines that the detected value is a value exceeding the second threshold value.

  An image forming apparatus according to the present invention includes the above-described image reading device and an image forming unit that forms an image on a recording medium based on reading information output by reading a document by the reading unit. can do.

The image reading program of the present invention reads a document that is fixedly arranged facing the reading position, conveyed to the reading position, and a reference plate arranged at the reading position, and outputs reading information. Based on the read information output by reading the reference plate with the reading means and the reference information acquired in advance, it is detected whether at least one of the reading surface of the reading means and the reference plate is contaminated. A calculation means for calculating a detection value for performing the detection, whether the detection value calculated by the calculation means is equal to or greater than a first threshold value for determining whether the dirt is present and whether the detection value is abnormal. said first whether the value of the threshold is greater than the second threshold value or less in the range, and the detection value determining means for determining whether or not a value exceeding the second threshold for determining, said determination By means of If the value is determined to be within this range, that at least one dirt of the reading surface and the reference plate of the reading means is present, the notification control means for notifying the notification means, And a control means for controlling the initialization process for eliminating the abnormality of the detection value when the determination means determines that the detection value exceeds the second threshold value. It is a program to make it function.

According to the first, ninth, and tenth aspects of the present invention, at least one of the reading surface and the reference plate of the reading unit is cleaned even if the reading surface and the reference plate of the reading unit are cleaned, as compared with the case where this configuration is not provided. It is possible to eliminate the annoyance of being informed of the presence of dirt on the screen.

Further , according to the first, ninth and tenth aspects of the invention, an effect is obtained that the abnormality can be quickly eliminated as compared with the case where the present configuration is not provided.

According to the second aspect of the present invention, as compared with the case where the present configuration is not provided, there is an effect that it is possible to reduce useless processing in which the detected value continues to exceed the second threshold value.

According to the invention of claim 3 , it is possible to immediately detect whether or not dirt such as paper dust has been removed by cleaning the reading surface of the reading means and the reference plate, as compared with the case without this configuration. The effect of being able to be obtained is obtained.

According to the invention of claim 4 , whether dirt such as paper dust adheres to at least one of the reading surface of the reading unit and the reference plate immediately after use of the reading unit as compared with the case without this configuration. The effect of being able to detect whether or not is obtained.

According to the invention of claim 5, in the image reading apparatus that performs double-sided reading of the original, the present invention is applied to the reading means for back side reading that is particularly easily affected by dirt such as paper dust. Even if the reference plate is cleaned, it is possible to eliminate the annoyance that it is continuously informed that dirt is present on at least one of the reading surface of the reading unit and the reference plate.

According to the invention of claim 6 , when dirt such as paper dust adheres to at least one of the reading surface of the reading unit and the reference plate by executing double-sided reading, compared with the case without this configuration, The effect is that the presence can be detected immediately.

According to the seventh aspect of the invention, there is an effect that the double-sided reading can be executed in a state where the abnormality is eliminated.

According to the eighth aspect of the invention, an effect is obtained that the presence or absence of abnormality can be quickly grasped as compared with the case where the present configuration is not provided.

1 is a diagram illustrating an overall configuration of an image reading apparatus according to a first embodiment. It is a figure which shows the hardware constitutions of an image reading apparatus. It is a figure which shows the detail of a back surface image reading control part. It is a figure which shows the curve corresponding to reference | standard data, and the curve corresponding to read data. 3 is a flowchart showing the contents of an image reading processing routine in the image reading apparatus according to the first embodiment. It is an external view which shows the outline of the image forming apparatus which concerns on 2nd Embodiment.

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

  First, the overall configuration of the image reading apparatus 10 according to the first embodiment will be described with reference to FIG.

  As shown in FIG. 1, the image reading apparatus 10 includes a document conveying unit 12 (DADF: Dual Auto Document Feeder) including a back image reading unit 28 and a front image reading unit 14.

  The document transport unit 12 includes a document table 20 on which a document 18 on which an image is recorded is placed, a take-out roll 22 that takes out the documents 18 placed on the document table 20 one by one, and a transport provided with a plurality of transport roll pairs 26. A path 24, a back image reading unit 28, a reference plate 46 disposed opposite to the back image reading unit 28, and a paper discharge unit 30 that discharges a document that has been read.

  The back image reading unit 28 includes a light source 28B including a plurality of light emitting elements arranged along the main scanning direction for irradiating illumination light to the document 18 and the reference plate 46, the document 18 illuminated by the light source 28B, and This is a fixed contact type image sensor configured to include a line sensor 28A that divides the reference plate 46 into a plurality of pixels and performs photometry and outputs read data corresponding to the pixel values measured for each pixel. The reference plate 46 is a reference plate read by the line sensor 28A at the time of shading correction or paper dust detection to be described later. For example, a white resin plate or a metal plate painted in white can be used.

  An opening / closing door 51 </ b> A is provided at a position corresponding to the back image reading unit 28 of the cover that covers the entire document conveying unit 12. The user can open the open / close door 51 </ b> A to clean the back surface image reading unit 28. An opening / closing sensor 51B for detecting opening / closing of the opening / closing door 51A is provided in the vicinity of the opening / closing door 51A.

  On the other hand, the surface image reading unit 14 includes a transparent platen glass 32 on which an original 18 can be placed, and the surface reading position is located on the upper surface of the platen glass 32. Below the platen glass 32 at the surface reading position, a light source 34 that irradiates illumination light toward the surface of the document 18, a first reflection mirror 36 that receives reflected light reflected on the surface of the document 18, and a first reflection mirror A second reflecting mirror 38 for bending the traveling direction of the reflected light received at 36 by 90 °, and a third reflecting mirror 40 for further bending the traveling direction of the reflected light received by the second reflecting mirror 38 by 90 °. ing. The surface image reading unit 14 includes a lens 42 and a photoelectric conversion unit 44 including a plurality of pixels. The surface image reading unit 14 converts the reflected light reflected by the third reflecting mirror 40 into the lens. The surface of the original 18 is read by forming an image on the photoelectric conversion unit 44 by 42.

  According to the image reading apparatus 10 of the first embodiment configured as described above, the documents 18 placed on the document table 20 are taken out one by one by the take-out roll 22 and sent to the conveyance path 24. The document 18 sent to the conveyance path 24 is conveyed to the surface reading position by the surface image reading unit 14 by the conveyance roller pair 26, and the surface is read by the surface image reading unit 14. Thereafter, the document 18 is conveyed to the back image reading unit 28 installed on the downstream side in the conveyance direction from the front surface reading position, and the back surface is read by the back image reading unit 28 and then discharged to the paper discharge unit 30. The

  Note that the image reading apparatus 10 according to the first embodiment uses a fluorescent lamp as the light source 34, but is not limited to this, and a plurality of LEDs (which are arranged along a direction intersecting the conveyance direction of the document 18 ( Other light sources such as a light emitting diode may be applied.

  In the image reading apparatus 10 according to the first embodiment, a CCD line sensor composed of a plurality of CCDs (Charge Coupled Devices) is applied as the photoelectric conversion unit 44. However, the present invention is not limited to this, and a CMOS (Complementary Metal) is used. -Oxide Semiconductor) A solid-state imaging device such as an image sensor may be applied.

  In the image reading apparatus 10 according to the first embodiment, the light source 34, the first reflection mirror 36, the second reflection mirror 38, and the third reflection mirror 40 are movable in the direction of arrow A in FIG. Yes. As a result, when the document conveying unit 12 is opened above the surface image reading unit 14 and the document 18 is placed on the upper surface of the platen glass 32, the illumination light is emitted from the light source 34 toward the document 18, and the arrow By moving the light source 34, the first reflecting mirror 36, the second reflecting mirror 38, and the third reflecting mirror 40 in the A direction, it is possible to read the image recorded on the document 18.

  Next, the hardware configuration of the image reading apparatus 10 will be described with reference to FIG. The image reading apparatus 10 mainly includes a controller 50, an image reading control unit 52, a DADF control unit 54, a back image reading control unit 56, and a UI (User Interface) 60.

  Among these, the controller 50 controls the entire image reading apparatus 10. Further, the controller 50 receives read data from each of the image reading control unit 52 and the back surface image reading control unit 56. Further, the controller 50 receives a signal indicating a user instruction or the like input from the UI 60.

  The image reading control unit 52 controls the entire image reading process in the image reading apparatus 10, and specifically, the DADF control unit 54, the back image reading control unit 56, the front surface image reading unit 14, and the scanning control unit 72. And the lighting control unit 76 and the like are controlled. Further, the image reading control unit 52 can access a front surface ROM (Read Only Memory) 68 and a front surface NVM (Non Volatile Memory) 70. The front surface ROM 68 and the front surface NVM 70 store various programs for reading the surface of the original, various information used at that time, and the like.

  Note that the scanning control unit 72 performs control related to scanning when reading a document, and also controls the motor 74. This motor 74 is a motor that integrally moves the light source 34 and various mirrors described in FIG. The illumination control unit 76 controls the light source 34.

  The DADF control unit 54 controls DADF, and receives information from each roller control unit 64 and each sensor 62 that controls each motor 66 for rotating the take-out roll 22 and the transport roll pair 26 described above. To do. Examples of each sensor 62 include a sensor that detects whether or not the document conveying unit 12 is opened above the surface image reading unit 14, and the above-described open / close sensor 51B.

  The back image reading control unit 56 controls the back image reading unit 28. The back image reading control unit 56 can access a back surface ROM 82, a back surface RAM (Random Access Memory) 84, a back surface NVM 86, and a back surface EEPROM (Electrically Erasable and Programmable Read Only Memory) 88.

  The back ROM 82 and the back NVM 86 store a program for operating the back image reading control unit 56, various information used at that time, and the like. The back surface RAM 84 is a memory used when the back surface image reading control unit 56 operates. The back surface EEPROM 88 stores reference data obtained by photometric measurement of a reference plate (a dedicated clean white reference plate different from the reference plate 46) that is not contaminated by the line sensor 28A that is not contaminated. Here, “dirt” includes all dirt assumed to adhere to the line sensor 28A and the reference plate 46, such as paper powder and toner powder. Here, a case where reference data obtained from a clean white reference plate is used will be described. However, the reference data is compared with read data output by reading the reference plate 46 in the processing described later, and the line sensor 28A. Any data may be used as long as it can determine whether at least one of the reference plate 46 is contaminated.

  Further, as shown in FIG. 3, the back surface image reading control unit 56 executes paper dust detection processing for detecting whether or not dirt such as paper dust exists on the reading surface of the line sensor 28 </ b> A and the reference plate 46. The detection value calculation unit 96 and the determination unit 98 can be represented by a configuration. More specifically, the detection value calculation unit 96 acquires read data output by reading the reference plate 46 by the back surface image reading unit 28. Further, the reference data stored in the back surface EEPROM 88 is acquired. By comparing these read data and reference data, a detection value D for detecting whether or not dirt such as paper dust exists on the reading surface of the line sensor 28A and the reference plate 46 is calculated.

  The detection value D is a value indicating how much the read data obtained by reading the reference plate 46 is deviated from the reference data. Here, the detected value D will be described with an example. FIG. 4 shows a curve Q corresponding to the reference data and a curve R corresponding to the read data obtained by reading the reference plate 46. In the figure, the horizontal axis indicates the position of the pixel in the main scanning direction, and the vertical axis indicates the pixel value (or the value obtained by multiplying the pixel value of the read data and the reference data by a predetermined coefficient). In the read data, two pixel values affected by dirt such as paper dust are shown. In each of the reference data (curve Q) and the read data (curve R), the values of the pixel values having the same pixel position in the main scanning direction are α and β, respectively, and the ratio β / α is the detection value D.

  When the read data is not affected by dirt such as paper dust, the curve Q and the curve R are almost similar, and the detection value D is within a predetermined range. On the other hand, when the read data is affected by dirt such as paper dust, the detection value D is likely to be outside the predetermined range. Specifically, when the read data is not affected by dirt such as paper dust, the detection value D is distributed in the vicinity of a certain value (for example, 1.0). When affected by dirt, the detection value D is highly likely to be significantly different from 1.0. Thus, the presence or absence of dirt such as paper dust can be determined using the detection value D.

  A specific calculation method when the detection value D is β / α described above will be described. For example, the pixel information (pixel value) for each pixel of the read data acquired from the back surface image reading unit 28 is stored in the line memory. Further, the reference data acquired from the back surface EEPROM 88 is developed for each pixel in the reference data development area. Each of the read data and reference data for each pixel is multiplied by a predetermined coefficient. The predetermined coefficient is a coefficient such that the value of β / α is 1.0 when the read data is not affected by dirt such as paper dust. Then, the ratio between the read data after multiplication by the coefficient and the reference data is calculated as a detection value D.

  The calculation method of the detection value D is not limited to the above method, and the difference between the read data and the reference data, the ratio or difference between the average of the read data and the average of the reference data, the standard deviation of the read data and the reference data You may calculate by ratio or a difference with a standard deviation.

  The determination unit 98 outputs a detection result of paper dust detection by comparing the detection value D calculated by the detection value calculation unit 96 with the threshold value Dth1 and the threshold value Dth2. The threshold value Dth1 is a threshold value for determining whether or not dirt such as paper dust exists on at least one of the reading surface of the line sensor 28A and the reference plate 46. The threshold value Dth2 is a threshold value for determining whether or not the detection value D calculated by the detection value calculation unit 96 is an abnormal value due to an abnormality such as a device failure or poor contact. The detection value D at the time of abnormality takes a large value that is clearly different from the threshold value Dth1. Therefore, a threshold value Dth1 for detecting normal dirt such as paper dust, and a threshold value Dth2 that is a threshold value for determining that the detection value D exceeds the threshold value Dth1 due to an abnormality and is larger than the threshold value Dth1. And are set in advance. That is, if the detection value D is less than the threshold value Dth1, it indicates that there is no dirt and no abnormality has occurred. Further, if the detection value D is a value within the range of the threshold value Dth1 or more and the threshold value Dth2 or less, it indicates that a stain such as normal paper dust is detected. Further, if the detection value D exceeds the threshold value Dth2, it indicates that an abnormality such as a device failure or contact failure has occurred.

  Next, the operation of the image reading apparatus 10 according to the first embodiment will be described. When the power of the image reading apparatus 10 is turned on, the controller 50 executes an image reading processing routine shown in FIG.

  In step 100, initialization processing is executed. The initialization process is, for example, an auto offset control (AOC) process, an auto gain control (AGC) process, a shading (SHD) correction data collection process, or the like.

  In the AOC process, an offset adjustment value (AO) for adjusting variations in dark outputs of the photoelectric conversion unit 44 and the line sensor 28A based on the outputs of the photoelectric conversion unit 44 and the line sensor 28A when the white reference plate is read. Value) is calculated, and the calculated AO value is set in a predetermined register. In the AGC processing, gain adjustment values (AG values) for adjusting the output levels of the photoelectric conversion unit 44 and the line sensor 28A based on the outputs of the photoelectric conversion unit 44 and the line sensor 28A when the white reference plate is read. And the calculated AG value is set in a predetermined register. In the SHD correction data collection processing, auto gain control and auto offset control are performed on the outputs of the photoelectric conversion unit 44 and the line sensor 28A when the white reference plate is read, and the photoelectric conversion is performed based on the A / D converted digital image data. The shading (SHD) correction value for one line for correcting the non-uniform pixel sensitivity and the non-uniform light amount distribution of the conversion unit 44 and the line sensor 28A is calculated, and the calculated SHD correction value is stored in a predetermined storage area. To do.

  Next, in step 102, information detected by the open / close sensor 51B is acquired, and it is determined whether or not the open / close door 51A at the position corresponding to the back image reading unit 28 is closed. If it is determined that the open / close door 51 </ b> A is closed, it is considered that the user has cleaned the back surface image reading unit 28, and the process proceeds to step 104. If closing of the opening / closing door 51A is not detected, the process proceeds to step 116.

  In step 104, it is determined whether or not the initialization process has been completed. If the initialization process incomplete flag is set in the processing described later, a negative determination is made and the routine proceeds to step 116. If the initialization process incomplete flag is not set, an affirmative determination is made and step 106 is performed. Migrate to

  In step 106, paper dust detection processing is executed. Specifically, the read data output by reading the reference plate 46 by the back surface image reading unit 28 and the reference data stored in the back surface EEPROM 88 are acquired. Then, by comparing these read data with the reference data, a detection value D for detecting whether or not dirt such as paper dust is present on the reading surface of the line sensor 28A and the reference plate 46 is calculated.

  Next, in step 108, it is determined whether or not the detection value D calculated in step 106 is smaller than a threshold value Dth1. In the case of D <Dth1, it can be determined that there is no dirt such as paper dust and no abnormality has occurred, so the routine proceeds to step 116 as it is. On the other hand, when D ≧ Dth1, the process proceeds to step 110, and it is determined whether or not the detection value D is equal to or less than the threshold value Dth2. When D ≦ Dth2, that is, when the detection value D is not less than the threshold value Dth1 and not more than the threshold value Dth2, it is determined that at least one of the line sensor 28A and the reference plate 46 has dirt such as paper dust, The process proceeds to step 112. In step 112, it is notified that dirt such as paper dust has been detected. For example, a message that prompts the user to clean the back side image reading unit 28 is displayed on the UI 60 because dirt such as paper dust is detected. On the other hand, if D> Dth2, the process proceeds to step 114, and a flag indicating that the initialization process is not completed is set. That the detection value D exceeds the threshold value Dth2 indicates that there is a possibility that an apparatus failure or contact failure has occurred. In order to eliminate such an abnormality, the initial value is set in a later step. This is a process for executing the digitization process.

  Next, in step 116, it is determined whether or not there is a job to be executed by determining whether or not a job start signal for instructing to start reading a document image (job) is received. If there is a job to be executed, the process proceeds to step 118; otherwise, the process returns to step 102.

  In step 118, it is determined whether the job indicated by the job start signal received in step 116 is a single-side job for reading one side (front side) of a document or a double-side job for reading both sides of a document. In the case of a single-sided job, the process proceeds to step 120 and the single-sided job is executed. Specifically, the document is conveyed to the surface reading position by the surface image reading unit 14, the surface is read by the surface image reading unit 14, and the automatic offset control based on the set AO value is set for the read data. The automatic gain control based on the AG value and the shading correction based on the stored SHD correction value are performed. Data obtained by performing each of these processes is output as read data. Then, the original is discharged to the paper discharge unit 30. When the one-sided job is completed, the process returns to step 102.

  On the other hand, when it is determined that the job indicated by the job start signal received in step 118 is a double-sided job, the process proceeds to step 122 to determine whether or not the initialization process has been completed. If the initialization process incomplete flag is not set, an affirmative determination is made and the routine proceeds to step 126. On the other hand, when the initialization process incomplete flag is set, it indicates that the detection value D calculated in the above step 106 exceeds the threshold value Dth2, and there is an abnormality such as a device failure or contact failure. Since there is a possibility that the error has occurred, the process proceeds to step 124, and initialization processing is executed to eliminate these abnormalities. When the initialization process is completed, the initialization process incomplete flag is deleted, and the process proceeds to step 126.

  In step 126, a duplex job is executed. Specifically, the document is transported to the surface reading position by the surface image reading unit 14, the surface is read by the surface image reading unit 14, and each of auto offset control, auto gain control, and shading correction is performed on the read data. The read data of the processed surface is output. Then, the original is conveyed to a back side reading position by the back side image reading unit 28, the back side is read by the back side image reading unit 28, and the back side read data obtained by performing each of the above-described processes is output for the read data. Then, the original is discharged to the paper discharge unit 30.

  Next, in step 128, the paper dust detection process is executed in the same manner as in step 106, and the detection value D is calculated. Next, in step 130, it is determined whether or not the detection value D calculated in step 128 is smaller than the threshold value Dth1, and if D <Dth1, the process returns to step 102 as it is. On the other hand, when D ≧ Dth1, the routine proceeds to step 132, where it is determined whether or not the detected value D is equal to or less than the threshold value Dth2. In the case of D ≦ Dth2, the process proceeds to step 134 to notify that dirt such as paper dust has been detected, and then returns to step 102. On the other hand, if D> Dth2, the process proceeds to step 136, a flag indicating that the initialization process is not completed is set, and the process returns to step 102.

  If it is determined in step 116 that the job start instruction signal has not been received even after a predetermined time has elapsed, the process may be shifted to power-off or energy-saving mode.

  Further, in steps 114 and 136 described above, a message indicating that an abnormality such as a device failure or contact failure has occurred may be displayed on the UI 60 based on the detected value D exceeding the threshold value Dth2. .

  Further, in step 102 described above, the case where the back surface image reading unit 28 is considered to have been cleaned by closing the open / close door 51A has been described. However, the button that is selected and pressed by the user when the back surface image reading unit 28 has been cleaned. May be displayed on the UI 60, and when this button is selected, it may be determined that the back side image reading unit 28 has been cleaned. In addition, when a mechanism for automatically cleaning the back surface image reading unit 28 is provided, it may be determined that the back surface image reading unit 28 has been cleaned by receiving a cleaning end signal by this mechanism.

  The processing flow of each flowchart described above is an example, and the processing order may be changed, new steps may be added, or unnecessary steps may be deleted without departing from the scope of the present invention. it can.

  Next, a second embodiment will be described. The second embodiment is an image forming apparatus 11 that includes the image reading apparatus 10 of the first embodiment.

  As shown in FIG. 6, the image forming apparatus 11 according to the second embodiment includes an image reading device 10, an image forming unit 80, a sheet feeding unit 82, and a printed matter discharging unit 84. ing. The configuration of the image reading device 10 is the same as the configuration of the image reading device 10 of the first embodiment.

  The image forming unit 80 prints a document image on paper by an electrophotographic method, and each color (Y: yellow, M: magenta, C: cyan, K: black) on the endless intermediate transfer belt and the intermediate transfer belt. And an electrostatic latent image is formed on the photosensitive drum by exposing the photosensitive drum (described later) of the image forming unit with a laser beam modulated based on the image information. And an optical part.

  The image forming unit includes a photosensitive drum, a charger that uniformly charges the surface of the photosensitive drum, and a toner image obtained by developing an electrostatic latent image formed on the surface of the photosensitive drum by an optical unit with toner of each color. And a transfer roller for pressing the intermediate transfer belt against the photosensitive drum. The intermediate transfer belt is driven by a driving roller connected to a motor.

  The image forming unit 80 also transfers a toner image formed on the intermediate transfer belt to a sheet fed from the sheet feeding unit 82, and fixes the toner image transferred to the sheet on the sheet. A fixing unit and a discharge roller that discharges the paper that has passed through the fixing unit to the printed material discharge unit 84 are provided.

  The sheet feeding unit 82 includes a plurality of sheet cassettes that respectively store sheets having different orientations, sizes, and quality, and a plurality of rollers that take out the sheets from each sheet cassette and convey them to the transfer unit of the image forming unit 80. With.

  According to the image forming apparatus 11 of the second embodiment configured as described above, the sheet feeding unit 58 is used in the image forming unit 80 based on the read data output by reading the document with the image reading device 10. An image is formed on the paper fed from the printer.

  In the second embodiment, an image forming apparatus employing an electrophotographic image forming unit has been described. However, the present invention can also be applied to an inkjet image forming apparatus.

DESCRIPTION OF SYMBOLS 10 Image reading apparatus 11 Image forming apparatus 14 Front surface image reading part 28 Back surface image reading part 28A Line sensor 28B Light source 46 Reference plate 50 Controller 51A Opening / closing door 51B Opening / closing sensor 52 Image reading control part 56 Back surface image reading control part 80 Image forming part 96 Detection value calculation unit 98 determination unit

Claims (10)

A reading unit that is fixedly arranged facing the reading position, reads a document conveyed to the reading position, and a reference plate arranged at the reading position, and outputs reading information;
Based on the read information output by reading the reference plate with the reading means and the reference information acquired in advance, it is detected whether or not there is dirt on at least one of the reading surface of the reading means and the reference plate. Calculating means for calculating a detection value for performing,
A detection value calculated by the calculation means is not less than a first threshold value for determining whether or not the dirt is present, and is greater than the first threshold value for determining whether the detection value is abnormal. Determination means for determining whether or not the value is within a range of two threshold values or less and whether or not the detected value is a value exceeding the second threshold value ;
Informing means for informing that at least one of the reading surface of the reading means and the reference plate is contaminated when the determination means determines that the detected value is a value within the range;
Control means for performing control so that initialization processing for eliminating the abnormality of the detection value is executed when the determination means determines that the detection value is a value exceeding the second threshold;
An image reading apparatus. The control unit calculates the detection value by the calculation unit until the initialization process is executed when the determination unit determines that the detection value exceeds the second threshold value, and the image reading apparatus according to claim 1, wherein the control so as not to perform determination by the determination means. When at least one of the cleaning of the reading surface and the reference plate of the reading means has been recognized to have been carried out, the calculation of the detection value by said calculating means, and wherein a determination by the determination means according to claim 1 or claim 2, wherein Image reading apparatus. After reading the original by the reading means, the calculation of the detection value by said calculating means, and an image reading apparatus according to any one of claims 1 to 3 for determination by the determination means. It said reading means includes an image reading apparatus according to any one of claims 1 to 4 is a rear reading of the reading means used in performing the double-sided reading of the document. 6. The image reading apparatus according to claim 5 , wherein after the reading unit performs back side reading in double-sided reading of the document, the calculation value is calculated by the calculation unit, and the determination by the determination unit is performed. Wherein, before executing the read both surfaces of the document, the image reading apparatus according to claim 5 or claim 6, wherein performing the initialization process. The notification means, wherein when the detection value is determined to be a value exceeding the second threshold value by the determination means, an image of any one of claims 1 to 7 for notifying the abnormal reading device . An image reading apparatus according to any one of claims 1 to 8 ,
An image forming unit that forms an image on a recording medium based on read information output by reading a document by the reading unit;
An image forming apparatus including: Computer
A reading unit that is fixedly arranged facing the reading position, reads a document conveyed to the reading position, and a reference plate arranged at the reading position, and reads the reference plate by a reading unit that outputs reading information, and outputs the reading Calculation means for calculating a detection value for detecting whether or not dirt exists on at least one of the reading surface of the reading means and the reference plate based on the information and reference information acquired in advance;
A detection value calculated by the calculation means is not less than a first threshold value for determining whether or not the dirt is present, and is greater than the first threshold value for determining whether the detection value is abnormal. Determining means for determining whether or not the value is within a range of two thresholds or less and whether or not the detected value is a value exceeding the second threshold ;
By the determination unit, when said detection value is determined to be within this range, that at least one dirt of the reading surface and the reference plate of the reading means is present, to notification by the notification means Notification control means for controlling , and
Function as control means for controlling the initialization process for eliminating the abnormality of the detection value to be executed when the determination means determines that the detection value exceeds the second threshold value An image reading program for causing