JP2018156178A - Image processing apparatus, image processing method, and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To distinguish a streak caused by an abnormality of a printer from a chart printed by a printer, and to appropriately detect a streak caused by an abnormality of the printer. , Provides image processing methods and programs. An image processing device is an image processing device having an image forming unit and a scanner that reads an image line by line, and the image is read by the scanner, detected from the acquired image data, and is detected in a first direction of the image. Using the feature amount, the acquisition means for acquiring the feature amount of the streak-shaped image extending in the direction along the line, and the direction in which the paper is installed in the scanner installation portion in order to read the paper on which the chart image is formed by the image forming portion by the scanner. It has a determination means for determining the image, and a detection means for detecting a streak-like image from the image data obtained by scanning the chart image formed on the paper placed in the direction for each line by a scanner. [Selection diagram] Fig. 3

Description

  The present invention relates to an image forming apparatus, a control method for the image forming apparatus, and a program.

  When the image forming apparatus is used for a long time without maintenance such as replacement of parts, the developing device, the photosensitive member, the cleaning member, etc. are deteriorated, and the printed image has a direction perpendicular to the front edge of the paper conveyance direction at the time of printing ( Abnormalities such as streaks extending in the first direction may occur.

  Abnormalities such as streaks that occur in an image printed due to such deterioration are difficult to automatically detect using a sensor or the like. Therefore, in many cases, after receiving an indication from the user, the service person goes to the user and deals with the image forming apparatus in which an abnormality has occurred. However, streaks and other abnormalities are difficult to express in words. For example, even if you say "Streak has occurred on the printed image", if you do not know detailed information such as the color of the generated streak and the direction, position, and width in which the streak appears on the image, the service person will identify the cause Can not do it. Therefore, when the user indicates that “a streak has occurred on the printed image”, the service person needs to go to the user and check the state of the generated streak.

  The service person predicts the failure location that causes the streak and identifies the related member, returns to the service base once, obtains the member, visits the user again, and replaces the member. It was. Such an exchange not only costs the serviceman to move, but also makes the image forming apparatus unusable until the correspondence is completed. Therefore, downtime occurs in the image forming apparatus, and the productivity of the user is greatly reduced.

  Therefore, in Patent Document 1, the chart output by the printer is scanned, the scanned image is divided, threshold processing is performed on this divided area, and the presence or absence of streaks (white spots) is determined, so that the printer breaks down. A technique for diagnosing whether or not there is disclosed.

JP2011-137895A

  When the chart is scanned with an ADF (Auto Document Feeder), streaky images may be generated in the image data obtained by scanning the chart due to dirt on the glass surface of the reading unit of the scanner. . Therefore, when a streak caused by a stain on the scanner reading unit occurs when analyzing a streak caused by a printer failure, a streak caused by a printer failure and a streak caused by the stain on the scanner reading unit, etc. I can't distinguish. Therefore, there is a possibility that the printer failure diagnosis performed based on the image data obtained by scanning the chart cannot be appropriately performed.

In order to solve the above problems, the present image processing apparatus is an image processing apparatus having an image forming unit that forms an image and a scanner that reads an image line by line, and is obtained by reading an image line by line by the scanner. An acquisition unit that acquires a feature amount of a streak-like image that is detected from image data and extends in a direction along a first direction of the image; and a sheet on which a chart image is formed by the image forming unit is read by the scanner Determining means for determining the direction in which the paper is to be installed in the installation section of the scanner using the feature amount of the streak-like image acquired by the acquiring means; and paper set in the direction determined by the determining means The chart image formed on the chart image is read for each line by the scanner, and the streak-like image in the chart image is read from the read image data. And detection means for output,
It is characterized by having.

  According to the present invention, it is possible to analyze a streak (printer streak) caused by a printer failure without being affected by a streak (scan streak) caused by dirt or the like on the reading unit of the scanner. Furthermore, by specifying the scan method only when a scan streak that affects the printer streak analysis has occurred, it is possible to prevent usability degradation during printer streak analysis.

1 is a configuration diagram of a system of an image processing apparatus. It is the figure which showed the flow of the image processing. It is the figure which showed the flow of the image diagnostic process. It is the figure which showed the chart for a streak detection, and the example of the generated streak. It is the figure which showed the example which instruct | indicates the scanning method. It is the figure which showed the flow of the process which detects a scanning stripe. It is a figure showing a flow of processing which detects a printer stripe. It is the figure which showed the example of the area which detects a scanning stripe, and the calculated line signal value. It is a figure showing an example of an area for detecting a printer line and a calculated line signal value. It is the figure which showed the flow of the process which estimates a failure component. It is the figure which showed the example of the scanning stripe detection result. It is the figure which showed the block diagram of the image processing apparatus.

Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.
In this embodiment, a detection result of a streak generated by scanning at the time of image diagnosis is acquired, and a streak resulting from a printer failure is detected using the result.
FIG. 12 is a diagram showing a schematic configuration of a full-color MFP (Multi Function Printer) which is an example of an image forming apparatus according to an embodiment of the present invention. Note that the image forming apparatus according to the embodiment may be a monochrome MFP.

  In FIG. 12, reference numeral 101 denotes a full-color MFP which is an example of an image forming apparatus, and reference numeral 115 denotes a printer which functions as a printing unit in this embodiment. The printer 115 is provided with an image forming unit 1 that forms an image on a sheet, and a scanner 119 is provided on the upper surface of the printer 115. Further, a cassette feeding device 70 for feeding sheets to the image forming unit 1 is disposed below the printer 115.

  The image forming unit 1 includes four sets of process units 3 (Y, M) that respectively form yellow (Y), magenta (M), cyan (C), and black (K) toner images on a transfer belt 2 that is an ITB belt. , C, K). The process unit 3 is arranged in series in the order of Y, M, C, and K from the upstream side of the transfer belt 2 in the conveyance direction, and includes a developing device 4 that stores toner of each color and a photoconductor 5 that is an image carrier. Each has a similar structure.

  In the vicinity of the photoconductor 5 included in the process unit 3, a roller charger 6 that applies a uniform potential to the photoconductor 5 is disposed, and the surface of the photoconductor 5 is perpendicular to the moving direction of the photoconductor 5. It is attached so as to face.

  Below the process unit 3, a laser scanner 7 that performs image exposure on the photosensitive member 5 is disposed. The laser scanner 7 includes a polygon mirror 7a that deflects and scans a laser-emitted beam, and a first imaging lens 7b that spot-forms laser light on a drum. The laser scanner 7 includes a folding mirror 7c that reflects the laser light transmitted through the first imaging lens 7b in a predetermined direction, and includes an optical case that supports and fixes each optical element.

  A primary transfer roller 8 is disposed at a position facing the photoconductor 5 and sandwiching the transfer belt 2 therebetween. When the image forming unit 1 forms an image, the above-described laser scanner 7 exposes the image data of Y, M, C, K, and each color on the photoconductor 5 and also the photoconductor 5 by the developing unit 4. A toner image is developed on top. The toner image formed on the photoreceptor 5 is transferred to the transfer belt 2 by applying a voltage to the primary transfer roller 8. Note that the transfer residual toner remaining on the photoreceptor 5 after the toner image transfer is removed by a cleaning device 9 that collects the toner with a blade. Further, the photoconductor 5 is rotated clockwise in front view of FIG. 12 by power from a driving source (not shown) or by following the transfer belt 2.

  The transfer belt 2 is stretched by a transfer driving roller 11, a tension roller 12, and a driven roller 13. The transfer belt 2 is circulated in the direction of the arrow (counterclockwise) by the transfer driving roller 11, and the toner images formed on the respective photoreceptors 5 are sequentially superimposed and transferred.

  Further, the MFP 101 includes a control unit (control unit) 75 that controls the entire MFP 101 as shown in FIG. The control unit 75 includes a CPU circuit unit having a CPU, RAM, ROM, etc. (not shown). The CPU performs basic control of the entire MFP 101, and the ROM stores a control program for controlling the MFP 101 as a whole, for example, a control program for controlling the scanner 119, a control program for controlling the image forming unit 1, and the like. Yes. The RAM temporarily stores control data and is used as a work area for arithmetic processing associated with control.

  On the other hand, the cassette feeding device 70 has a sheet feeding cassette 15 and conveys the sheets S held in the sheet feeding cassette 15 one by one to the conveying path R by the conveying roller 15A. The direction in which the sheet is conveyed to the conveyance path R is the paper conveyance direction during printing. The sheets S held on the multi-feed tray 16 are conveyed one by one to the conveyance path R by the conveyance rollers 16A. The sheet S conveyed from the cassette feeding device 70 or the multi-feed tray 16 to the conveyance path R is temporarily stopped by a registration roller 17 disposed on the downstream side of the conveyance path R in the conveyance direction. The registration roller 17 starts to rotate in synchronization with the operation of the color image formed on the transfer belt 2 after the sheet S is temporarily stopped. As a result, the sheet S reaches the secondary transfer portion T, and the color image is secondarily transferred by the positive transfer bias applied to the secondary transfer roller 19.

  After the color image is secondarily transferred on the sheet S, the sheet S is conveyed from the secondary transfer portion T to the fixing device 20, and the color image is fixed by being heated and pressed by the fixing device 20. Here, when the image forming operation at the time of the secondary transfer is set to single-sided printing, after being fixed by the fixing device 20, the paper is discharged onto a paper discharge tray 22 by a paper discharge roller 21. In the case where the image forming operation at the time of the secondary transfer is duplex printing, the sheet S is fixed to one surface by the fixing device 20 and then the sheet S is transferred to the reversing unit 23 by the paper discharge roller 21. Be transported. The sheet S conveyed to the reversing unit 23 is turned upside down by the double-sided path 25, and the color image is again transferred to the other side by the secondary transfer roller 19. Thereafter, when the color image transferred to the other surface is fixed by the fixing device 20, the color image is discharged onto the paper discharge tray 22 by the paper discharge roller 21. Note that the transfer residual toner remaining on the transfer belt 2 after the secondary transfer onto the sheet S is removed by the cleaning device 10.

  In the scanner 119, the ADF 100 is provided in a state in which the ADF 100 can be opened and closed in the vertical direction. The ADF 100 has a paper feed tray 26 serving as a document placement unit on the upper side, and a paper feed roller 27, a separation conveyance roller 28, and a separation pad 29 are sequentially arranged in the vicinity of the paper feed tray 26. Further, on the transport path for transporting the installed document from the paper feed tray 26, a transport roller pair 30 and an upstream lead roller pair 31 are arranged in the same order, and a platen glass 58 is provided downstream in the transport direction. A surface reading unit 32 (hereinafter also referred to as a platen 32) is arranged.

  A front surface reading roller 33 made of a white roller is disposed above the platen 32 as viewed from the front, and an image reading unit 35 is disposed below the platen 32. The image reading unit 35 includes a lamp 36 that irradiates light on the surface of the document, a reflective shade 37, and a mirror 39. The reflected light from the document is guided to the lens unit 43 via the mirror 39 and the mirrors 41 and 42 of the mirror unit 40, and is imaged on the light receiving portion of the line sensor 18 by the lens unit 43 and subjected to photoelectric conversion. As a result, the document image is read. The line sensor 18 used for reading an image includes an image sensor such as a CCD (Charge Coupled Device) or a CMOS (Commentary Metal Oxide Semiconductor). In the MFP shown in FIG. 12, the line sensor is fixed, but the line sensor 18 is integrated with the image reading unit 35, and the line sensor 18 and the image reading unit 35 are movable in the direction perpendicular to the reading line. It may be there.

  A back surface reading roller 45, which is a white roller, a downstream read roller pair 46, and a paper discharge roller pair 47 are sequentially arranged downstream in the transport direction of the platen 32 in the transport path from the paper feed tray 26. Further, between the back surface reading roller 45 and the downstream read roller pair 46, a back surface reading unit 50 having a reading unit 49 serving as a reading position of the back surface of the document is disposed.

  The back side reading unit 50 includes a lamp 51 that irradiates light to the back side of the document, mirrors 52, 53, 55, a lens unit 56, and an image sensor 60. The reflected light from the document is guided to the lens unit 56 via the mirrors 52, 53, and 55, and is imaged and photoelectrically converted by the lens unit 56 on the light receiving portion of the image sensor 60. As a result, the document image is read.

  The scanner 119 has a fixed reading mode in which a document set on a platen glass 57 (hereinafter also referred to as a platen glass 57) of the printer 115 is read by moving the image reading unit 35. In addition, there is a flow reading mode in which the original set on the paper feed tray 26 is fed in the direction of the platen 32 of the printer 115 and conveyed while the image reading unit 35 is stopped at a predetermined position. In the fixed reading mode, the platen glass 57 functions as a setting unit for setting the original in the flow reading mode.

  In the flow reading mode, the scanner 119 conveys the original placed on the paper feed tray 26 toward the platen 32 and the reading unit 49. At this time, the documents on the sheet feeding tray 26 are sequentially fed from the uppermost document by the sheet feeding roller 27, and are separated and conveyed one by one by the separation conveying roller 28 and the separation pad 29. The separated and transported document is transported by the transport roller pair 30 and the upstream read roller pair 31 to the platen 32 which is the reading position on the surface thereof.

  The document conveyed to the platen 32 is subjected to skew feeding and leading edge registration by causing the leading edge to abut against the nip portion of the upstream lead roller pair 31 to form a loop. Thereafter, the original is conveyed to the reading unit 49 which is the reading position on the back surface, and is then discharged onto the discharge tray 59 by the downstream read roller pair 46 and the discharge roller pair 47.

In the case of the fixed reading mode for reading the image of the document placed on the platen glass 57, the document is read while moving the image reading unit 35 from the document set reference (not shown) to the right in FIG. . A white reference member 61 serving as a white reference for reading the document by the scanner 119 is provided on the platen glass 57 at the abutting portion of the document when reading in the flow reading mode.
Hereinafter, the flow reading mode is referred to as scanning using ADF (Auto Document Feeder), and the fixed reading mode is referred to as pressure plate scanning.

  FIG. 1 is a configuration diagram of a system in this embodiment. The MFP 101 using four color toners of C, M, Y, and K is connected to other network compatible devices via the network 123. The PC 124 is connected to the MFP 101 via the network 123. A printer driver 125 in the PC 124 transmits print data to the MFP 101.

  The MFP 101 will be described in detail. The network I / F 122 exchanges print data and the like with other network compatible devices such as the PC 124 via the network 123. The controller 102 includes a CPU 103, a renderer 112, and an image processing unit 114. The interpreter 104 of the CPU 103 interprets the PDL (page description language) portion of the received print data and generates intermediate language data 105.

  Then, a CMS (Color Management System) 106 and a CMS 109 perform color conversion of the intermediate language data 105 using profile information described later, and generate intermediate language data (after CMS) 111.

  The CMS 106 performs color conversion using the source profile 107 and the destination profile 108 to generate intermediate language data (after CMS) 111.

  The source profile 107 converts a device-dependent color space such as RGB or CMYK into a device-independent color space such as L * a * b * (hereinafter referred to as Lab) or XYZ defined by the CIE (International Lighting Commission). It is a profile for. XYZ is a device-independent color space like Lab, and expresses colors with three types of stimulus values. The destination profile 108 is a profile for converting a device-independent color space into a CMYK color space depending on a device such as the printer 115.

  On the other hand, the CMS 109 performs color conversion of the intermediate language data 105 using the device link profile 110 to generate intermediate language data (after CMS) 111. The device link profile 110 is a profile for directly converting a device-dependent color space such as RGB or CMYK into a CMYK color space depending on a device such as the printer 115.

  Whether the CMS 106 or the CMS 109 is used is determined by a setting made by the user in the printer driver 125.

  In this embodiment, the CMS 106 and the CMS 109 are divided according to the types of the source profile 107, the destination profile 108, and the device link profile 110. However, a single CMS may handle a plurality of types of profiles. The type of profile is not limited to the example given in this embodiment, and any type of profile can be used as long as it generates intermediate language data (after CMS) 111 converted into a device-dependent CMYK color space such as the printer 115. It may be a profile.

  The renderer 112 generates a raster image 113 from the generated intermediate language data (after CMS) 111.

  The image processing unit 114 performs image processing on the raster image 113 and the image read by the scanner 119. Details of the image processing unit 114 will be described later with reference to FIG.

  A printer 115 connected to the controller 102 is a printer that forms an image on paper using C, M, Y, and K toners. The printer 115 is controlled by the CPU 127 and has a paper feeding unit 116 that feeds paper and a paper discharge unit 117 that discharges paper on which output data is formed.

  The display device 118 displays a screen for displaying an instruction to the user and a screen for notifying the user of the state of the MFP 101 in an image diagnosis process described later. The display device 118 displays not only image diagnostic processing but also a screen for displaying an instruction to the user when setting functions of the MFP 101 such as copying and scanning, and a screen for notifying the user of the state of the MFP 101.

  The scanner 119 is a scanner including the ADF 100. The scanner 119 irradiates a bundle or a single original image with a light source, and forms an original reflection image on a line sensor composed of a solid-state image pickup device such as a CCD sensor or a CMOS sensor with a lens. A line parallel to the line sensor is used as a reading line, and a raster-like image reading signal is obtained as image data for each line.

  The input device 120 is an interface for receiving input from the user. Some of the input devices are touch panels and are integrated with the display device 118.

  The storage device 121 stores data processed by the controller 102, data received by the controller 102, and the like.

The image diagnosis unit 126 prints a chart image for detecting an abnormal image when the user gives an instruction to perform image diagnosis processing, and uses the raster image 113 obtained by scanning the printed chart image to detect streak / failure component estimation. The image diagnosis process is performed by executing. Details of the processing will be described later.

  Server 128 is connected to MFP 101 via network 130 and network 123. FIG. 2 shows a case where the server 128 and the MFP 101 are installed in a remote environment such as when the MFP 101 and the server 128 are installed in different buildings and are connected via a plurality of networks. The server 128 and the MFP 101 may be connected via a plurality of networks as shown in FIG. 2 or may be connected via a single network. In this embodiment, only the MFP 101 is connected to the server 128. However, the server 128 may be connected to a plurality of MFPs and the server 128 may manage the information. The diagnostic result display unit 129 receives information such as the estimation result of the faulty part from the image diagnostic unit 126, displays the estimation result of the faulty part and the code corresponding to the fault, and notifies the service person or the like.

  Next, the flow of processing performed by the image processing unit 114 will be described with reference to FIG. FIG. 2 shows a flow of image processing performed on a raster image 113 obtained from an image input from the PC 124 or the like or an image read by the scanner 119. The processing of FIG. 2 is realized by executing an ASIC (Application Specific Integrated Circuit) (not shown) in the image processing unit 114.

  In step S 201, it is determined whether the image data received by the image processing unit 114 is scan data read by the scanner 119 or a raster image 113 sent from the printer driver 125.

  When the image data received by the image processing unit 114 is not scan data, the received image data is a raster image 113 that is bitmap-developed by the renderer 112. The developed raster image 113 is assumed to be the CMYK image 210 after being converted into CMYK depending on the printer device by the CMS, and the image processing unit 114 performs the subsequent processing.

  If the image data received by the image processing unit 114 is scan data, scan line detection processing is performed on the RGB image 202 in step S214, and the scan line detection result 215 is stored. A scanning streak is a streak-like image generated on an image during scanning. Details of the scan streak detection process and the detection result of this detection process will be described later. When the scanner 119 reads the front and back surfaces of the paper at the same time, the scanning unit detection results are individually stored because the reading units are different.

  Next, using the scan line detection result 215, a process for correcting the scan line is performed in step S216. The streak is corrected by interpolating with the surrounding pixels using the position / width information of the streak. This process will be described later.

  In step S203, color conversion processing is performed to generate a common RGB image 204. The common RGB image 204 is defined in an RGB color space that does not depend on a device. With this color conversion process, it is possible to convert scan data into data in a device-independent color space such as Lab by calculation.

  On the other hand, character determination processing is performed in step S205 to generate character determination data 206. Here, the character determination data 206 is generated by detecting the edge of the image.

  In step S207, the common RGB image 204 is filtered using the character determination data 206. Using the character determination data 206, different filter processing is performed for the character portion and other portions. In step S208, background removal processing is performed to remove ground color components.

  In step S209, color conversion processing is performed to generate a CMYK image 210. In step S211, the gradation characteristics of each single color of C, M, Y, and K are corrected using the 1D-LUT. The 1D-LUT is a one-dimensional LUT (Look Up Table) that is data for correcting the colors of C, M, Y, and K output from the printer.

  Finally, in step S212, the image processing unit 114 performs image forming processing such as screen processing and error diffusion processing to create a CMYK image (binary) 213.

  The scan stripe detection process S214 will be described in detail with reference to FIG.

  The processing flow of FIG. 6 is realized by executing an ASIC (Application Specific Integrated Circuit) (not shown) in the image processing unit 114.

  First, in step S <b> 601, an area at a specified position is cut out from the RGB image 202 obtained by scanning using the cut-out position information 602, and cut-out image data 603 is acquired. Here, the cut-out image data is rectangular data having a certain length or more in the direction perpendicular to the transport direction on the paper transported during reading by the ADF.

  Thus, in order to detect a scan line, a blank paper portion (portion where no image is formed) at the end of the RGB image 202 is cut out.

  In step S604, one line of image data is acquired from the cut-out image data 603. In step S605, gray scale conversion is performed using the monochrome conversion coefficient 606. A scan streak may be a colored streak, but is converted to a gray scale in order to use the same detection method as a black streak. A plurality of types of monochrome conversion coefficients 606 may be prepared. In that case, the gray scale conversion is executed by the number of monochrome conversion coefficients 606 for which the following processing from step S707 is prepared.

  In step S607, an average value of one line is calculated to calculate a line signal value 608. Details will be described later with reference to FIG.

In step S609, it is determined whether or not all lines have been processed. If it is determined that processing has not been performed, the process returns to step S604 to acquire one line of image data and repeat the processing. If it is determined that all the lines have been processed, scan streak detection processing is performed using the scan streak detection threshold 611 in step S610, and a scan streak detection result 215 is acquired.
The scan line detection result 215 includes information indicating the position and width of the detected line. Details will be described with reference to FIG.

  The cutout image data 603 and the line signal value 608 will be described with reference to FIG. FIG. 8A shows an example of the cut-out image data 603. This is data obtained by cutting out a blank paper portion 801 in which no image is formed in the RGB image 202, and a streak 802 indicates a scan streak. Scan streaks are caused by dust or dirt on the platen glass 58 of the scanner, the surface reading unit 32, or the like. When the ADF is used, the position of the unit including the solid-state image sensor is fixed, and the image data is acquired by transporting the paper. Therefore, if there is dust that causes streaks on the glass on the unit, the transport direction 803 is taken. Streaks occur.

  The line signal value 608 is calculated by calculating the average value for one line along the conveyance direction 803 for each position in the direction 804 perpendicular to the conveyance direction.

  FIG. 8B shows an example of the line signal value 608. A blank signal portion where a streak does not occur during scanning has a high line signal value 805, and a portion 802 where a streak occurs during scanning has a low line signal value 805.

  A threshold 806 is an example of the scan streak detection threshold 611. A line whose line signal value 805 is lower than the scan streak detection threshold 802 is detected as a streak.

  The CPU 103 calculates the continuity of the streaks from the detected scan streak detection result 612, and when the lines in which the streaks are continuously detected are continuous, these lines are collectively detected as one streak. Then, the width, position, brightness value, and the like are calculated for each detected streak and stored in the storage device 121 as the feature amount of the streak generated at the time of scanning.

  Note that the scan streak detection method is not limited to the above method, and the scan streak may be detected using a known method.

  The scan line detection result 215 will be described with reference to FIG. Scan stripe detection result 1101 indicates that five stripes have been found. Information on the position (for example, the starting point on the front side of the platen glass and indicating the distance therefrom) and the width is stored for each detected stripe. In this embodiment, position and width information is used, but any information obtained from the RGB image 202 such as a streak luminance value may be used.

  Next, the image diagnosis processing of this embodiment will be described with reference to FIG. The image diagnosis process is a process that is executed when an instruction is given by the user when the user recognizes that an abnormal image has occurred. In addition, this image diagnosis process is controlled by the image diagnosis unit 126. Of the following processing flow, the processing from step S301 to step S316 is implemented by the CPU 103 in the controller 102, and the acquired data is stored in the storage device 121. In addition, an instruction to the user is notified via the display device 118, and an instruction from the user is accepted via the input device 120.

  First, in step S301, the image data 302 is output by the printer 115 to obtain a chart image 303. At that time, the paper setting 304 at the time of printing is stored in the storage device 121. Here, the image data 302 is chart data for image diagnosis stored in the storage device 121. The raster image 113 processed by the image processing unit 114 and printed by the printer 115 and scanned using the scanner 119 is the scanned image data 308. FIG. 4C shows an image obtained by printing the chart image data 302 for image diagnosis (an original image in which no streak is generated). The diagnostic chart image 401 is a chart image for detecting streaks generated in an image formed by C, M, Y, and K toners at a time. An area 402 formed using C toner, an area 403 formed using M toner, an area 404 formed using Y toner, and an area 405 formed using K toner are included. Each of these areas is composed of an image having a uniform density.

  In step S315, the scan line detection result 215 is acquired.

  In step S316, the scan streak indicated by the scan streak detection result acquired in S315 is affected by the printer streak detection using the scan streak detection result 215, the paper setting 304 at the time of printing, and the printer streak detection influence determination threshold 317. Judge. A printer streak is a streak-like image generated due to an abnormality in the printer 115. If there are two types of scan streak detection results 215, one on the front side and one on the back side, determination processing is performed for each. Details of the determination process will be described later.

  Next, in step S318, it is determined whether there is a scan streak affecting the printer streak detection. If there is no scan streak, the scan is executed in step S307.

  If it is determined that there is a scan streak that affects printer streak detection, the user scans the diagnostic chart image 303 used in the image diagnostic process for the user by using the paper setting 304 for printing stored in step S305. Instruct the setting. Then, it is confirmed whether or not the diagnostic chart image 303 is set with the setting designated in step S306. The setting designated here is a setting so that the direction in which the printer stripe to be detected extends and the paper transport direction by the ADF are not the same direction. For example, if it is desired to detect streaks extending in the paper transport direction during printing with the A4 setting during printing, the ADF scan paper setting is set to A4R. Details of this will be described later.

  If it is determined that the paper is not set with the specified setting, the instruction in step S305 is repeated. You may display the screen for notifying a user that it is not according to the setting.

  If it is determined that the paper is set with the designated setting, scanning is executed with the ADF of the scanner 119 in step S307, and the scanned image data 308 is acquired. The scanned image data 308 will be described later.

  In step S309, a process for detecting a printer stripe using the scan stripe detection result 215 is executed to obtain a printer stripe feature quantity 310.

  In step S311, the printer line feature quantity 310 and the fault component estimation information 312 are used to estimate the fault component that causes the printer stripe, and the fault component estimation result 313 is output. Details of the printer stripe detection process S309 and the faulty part estimation process S311 will be described later.

  Finally, in step S314, the diagnostic imaging result is notified using the failure part estimation result 313. The diagnosis result display unit 129 of the server 128 connected via the network 123 and the display device 118 display a code corresponding to a part that may be broken. When the user notifies the service person of the diagnosis result or the code or the like, the service person can determine whether there is a failure and take measures in advance without going to the site.

The scanned image data 308 will be described in detail with reference to FIG. FIG. 4A shows an example of printing / scanning chart image data 302 for detecting streaks of the printer shown in FIG. This is an example when it is determined in step S318 that there is a scan streak that affects the streak detection of the printer. A streak 406 is a thin streak generated in all regions formed of C, M, Y, and K toners. A streak 407 is a wide and thin streak generated only in an area formed of C toner. A streak 408 is a dark streak generated only in an area formed of C toner. A streak 409 is a dark streak generated only in an area formed with M toner. A direction 410 indicates a paper conveyance direction during printing. Lines 406 to 409 are all printer lines extending in the direction along the sheet conveyance direction during printing.
A chart image 401 is a chart image for detecting streaks extending in a direction along a direction in which a sheet on which an image is printed is conveyed when printing is performed by a printer. In addition, when detecting a printer stripe generated in a direction different from the direction along the paper conveyance direction at the time of printing (for example, a direction perpendicular to the conveyance direction), data obtained by rotating the areas 402 to 405 in the vertical direction is used. It is necessary to use it.

  These printer stripes are generated due to factors such as clogging of the developing unit in the printer 115, damage to the drum, and toner adhering to the shutter of the exposure apparatus. Since this is a problem that occurs at a specific position on the main scan of the printer, streaks occur in the direction along the paper transport direction.

  Here, if a scan streak has occurred, if the conveyance direction when the diagnostic chart image is scanned by the ADF is the same direction 410 as the paper conveyance direction when the diagnostic chart is printed by the printer, the printer line 406 Scan streaks occur in the same direction as .about.409. Therefore, it becomes difficult to distinguish streaks caused by these different factors.

  Therefore, the conveyance direction when the diagnostic chart image is scanned by the ADF is set to a direction (direction 411) different from the direction 410 in which the printer stripe to be detected extends.

  Thus, the direction in which the printer stripe generated when the diagnostic chart image is printed is changed in the image and the direction in which the scan stripe generated when the printed diagnostic chart image is scanned are changed in the image. It becomes possible.

  A streak 412 is a scan streak generated in a direction 410 along the ADF transport direction 411.

  When the paper size is A4, 410 is the transport direction of the printer when setting to use A4 paper at the time of printing, and 411 is the transport direction of ADF when A4R is set at the time of scanning.

  The process for determining the influence on the detection of the printer stripe S316 will be described in detail.

  The streak position of the scan streak detection result 215 and the print area of the chart image obtained from the paper setting 304 at the time of printing are compared, and if it is within the streak position print area based on the scan streak detection result 215, the streak affecting the printer streak detection is detected. Judge that there is.

  Also, the line width of the scan line detection result 215 is compared with the printer line detection influence determination threshold value 317, and if there is a line whose scan line width of the scan line detection result 215 is equal to or larger than the threshold, the line that affects the printer line detection is detected. Judge that there is. The printer stripe detection influence determination threshold value 317 indicates the width of the stripe that can be visually determined. If the threshold value is less than that (when the width cannot be determined visually), it is determined that the stripe is not generated by the printer.

  An example is shown in FIG. FIG. 4B shows an example of printing / scanning a chart image for detecting a streak of the printer. This is an example of a case where it is determined in step S318 that there is no scan streak that affects printer streak detection. Since the chart image 401 is a chart image similar to the chart image 413, detailed description thereof is omitted. Lines 417 and 418 are scan lines, and are generated in a direction along the ADF paper conveyance direction 415. A scan streak occurs at any position on the main scan 414 of the scanner 119.

  Since the streak 417 is generated in the blank area 416 outside the chart image print area 419, it is determined that it does not affect the detection of the printer streak. The print area 419 can be calculated from margin information associated with the print paper setting 304. When the paper size is shorter than the main scanning of the scanner, the area outside the paper size is also treated as an area outside the print area 419.

  The streak 418 is a streak generated in the print area 419, but is a fine streak that is less than the printer streak detection influence determination threshold 317, and is thus determined not to affect the printer streak detection.

  The sheet setting instruction S305 at the time of scanning will be described with reference to FIG. 5A, 5B, and 5C show examples of UI displayed on the display device 118. FIG. The UI 501 is a screen when it is determined in step S318 that there is no scan streak. In this case, the detection of printer stripes is not affected regardless of the direction in which scanning is performed. Therefore, the user is not instructed about the scanning method (the direction in which the paper is set in the scanner), but is instructed only to point the printing surface upward so that an appropriate reading surface can be read. The user can press the read start button 502 regardless of which direction the diagnostic chart image is placed.

  A UI 503 is a screen when it is determined in S318 that there is a scan streak. In this case, it is necessary to instruct paper setting (paper setting direction) at the time of scanning. Here, since printing is performed at A4 in the example of FIG. 4, an instruction is given to install paper at A4R. If it is determined that the sheet on which the diagnostic chart image is printed is not set as instructed, the scan is not executed. In this case, the reading start button 504 may be disabled by graying out. If the instruction is in accordance with the instruction, the scan may be executed, and the read start button 504 can be executed without being grayed out. Note that even if the setting is not in accordance with the instruction, the UI may be such that the reading start button 504 is not grayed out and a rescan is requested by notifying that the instruction has not been instructed after the button is pressed.

  A UI 505 is another example of a screen when it is determined in S318 that there is a scan streak only on the surface. Since scanning stripes do not occur if scanning is performed on the back side, scanning on the back side is instructed. After executing the reading start button 506, it is determined in step S306 whether or not reading is performed on the back side.

  The printer stripe detection process will be described with reference to FIG.

  In step S <b> 701, cutout processing is performed on an area where a printer stripe is detected using the scan image data 308 and cutout position information 702, and cutout image data 703 is acquired. Here, the cut-out image data 703 is uniform data composed of C, M, Y, and K colors for detecting printer streaks, and 402 to 405 are areas for detecting streaks in the example of FIG.

  In step S704, one line of image data is acquired from the cut-out image data 603. In step S705, gray scale conversion is performed using the monochrome conversion coefficient 706. In order to detect streaks in the same process for the areas 402 to 405 configured by CMY and the K area 406, gray scale conversion is performed.

  In step S707, an average value is calculated for a specific pixel using the scanner feature value 310, and a line signal value 708 is calculated. Here, using the position information of the scan line detection result 215, the average value is calculated from the pixel values excluding the pixel at that position. Details will be described later with reference to FIG.

  In step S709, it is determined whether or not all lines have been processed. If it is determined that processing has not been performed, image data for one line is acquired and the process is repeated. If it is determined that all lines have been processed, printer streak detection processing is performed using the printer streak detection threshold 711 in step S710, and a printer streak detection result 712 is acquired. In step S713, the printer line feature quantity 310 is output using the printer line detection result 712. Here, the printer line feature amount 310 is information in which the position, width, brightness value, and the like are stored for each line of the printer.

  Finally, in step S714, it is determined whether or not all areas have been processed. If it is determined that processing has not been performed, data in areas that have not been processed is cut out in step S701, and the process is repeated.

  The cutout image data 703 and the line signal value 708 will be described with reference to FIG. FIG. 9A shows an example of the cut-out image data 703. The area 402 in FIG. 4 is cut out, and a streak 412 is a scan streak caused by an abnormality of the scanner. Reference numerals 901 and 902 denote pixel positions where there are no scan lines in the direction 410. In step S707, the average value is calculated using 901 and 902.

  FIG. 9B shows an example of the line signal value 708. The line signal value 903 is obtained by calculating the line signal value from FIG. The line signal value 903 is data obtained by acquiring data line by line in a direction 411 that is a direction perpendicular to the conveyance direction 410 of the printer, and calculating an average value of a portion where there is no scan line in one line. The luminance value is higher in the portion with the white stripe than the luminance value in the portion without the stripe, and the luminance value is lower in the portion with the black stripe.

A threshold 904 and a threshold 905 are examples of the printer stripe detection threshold 711. Threshold processing is performed on all the values of the line signal value 903, and a line-like image composed of pixels having luminance that is larger than the threshold 904 or lower than the threshold 905 is detected as a streak.
In step S713, the continuity of the streaks is calculated from the detected streak information, and the continuous streaks are calculated as one streak. Then, the width, position, and luminance value are calculated for each streak and stored as a feature amount.

  By excluding the influence of the scan line 412 in this way, it is possible to detect a printer line in the same manner as when there is no scan line, and it is possible to prevent a decrease in accuracy due to the scan line.

  The failure part estimation process will be described with reference to FIG. First, in step S1001, the printer stripe feature 310 is read, and the stripe detection result is analyzed. With reference to the width, position, and darkness of the streaks detected in each area, it is determined whether or not the same streaks occur in a plurality of areas.

  In step S1002, it is determined whether or not the same streak has occurred in all color plates. If the same streak has occurred, a faulty part is estimated from the printer streak feature quantity 310 and the faulty part estimation information 312 in step S1003. The failure part estimation information 312 stores the part of the printer 115 in association with the feature quantity at the time of failure. In step S1003, the failure part is estimated with reference to parts that do not depend on colors such as fixing and transfer drum. , And output as a faulty part estimation result 313.

  If it is determined in step S1002 that the same streak is not generated, a faulty part is estimated for each color from the printer streak feature quantity 310 and faulty part estimation information 312 in step S1004. A failure part is estimated from the failure part estimation information 312 by referring to a color-dependent part such as a developing unit, and is output as a failure part estimation result 313.

  In this embodiment, the scan streak detection result 215 is acquired at the time of executing the scan. However, for example, the streak detection process may be executed by automatically reading the reference plate (white plate) when the ADF unit is opened or closed.

  In addition, this embodiment is premised on scanning using ADF, but when there is a scanning stripe that affects printer stripe detection, scanning using a pressure plate may be instructed without using ADF.

  In the case of pressure plate scanning, the unit itself including the solid-state imaging device moves to acquire image data, so that the possibility of a scan streak is lower than image data obtained by scanning using ADF. .

  According to this embodiment, it is possible to analyze the streak caused by the printer without being affected by the streak caused by the scanner. Furthermore, it is possible to prevent a decrease in usability by designating a scan method only when a scan streak occurs.

(Other examples)
The present invention is also realized by executing the following processing. That is, software (program) for realizing the functions of the above-described embodiments is supplied to a system or apparatus via a network or various storage media, and a computer (or CPU, MPU, etc.) of the system or apparatus reads the program. It is a process to be executed.

Claims (10)

An image processing apparatus having an image forming unit that forms an image and a scanner that reads the image line by line,
An acquisition means for acquiring a feature amount of a streak-like image that is detected from image data acquired by reading an image line by line with the scanner and extends in a direction along a first direction of the image;
A direction in which the paper is set in the scanner setting unit for reading the paper on which the chart image is formed by the image forming unit by the scanner is determined using the feature amount of the streak-like image acquired by the acquisition unit. A decision means to
Detection means for reading a chart image formed on a sheet placed in a direction determined by the determination means for each line by the scanner, and detecting a streak-like image in the chart image from the read image data;
An image processing apparatus comprising:   The image processing apparatus according to claim 1, wherein the cause of abnormality in the image processing apparatus is analyzed using the streak-like image detected by the detection unit.   The image processing apparatus according to claim 1, further comprising a notification unit that notifies a user of an installation direction of a sheet read by the scanner so that the sheet is installed in the direction determined by the determination unit.   The image processing apparatus according to claim 1, wherein the feature amount of the streak image is a position and a width of a streak image detected from an image read by the scanner.   The determination means includes a chart formed by the image forming unit when the position of the streak-like image detected from the image data read by the scanner is a print area of a chart image formed by the image forming unit. The image processing apparatus according to claim 1, wherein a direction in which the sheet on which the chart image is formed is set is determined so that the image is read line by line in the direction along the first direction.   The determination unit is configured such that when the width of the streak image detected from the image data read by the reading unit is equal to or larger than a threshold value, the chart image formed by the image forming unit extends along the first direction. The image processing apparatus according to claim 1, wherein a direction in which the sheet on which the chart image is formed is set is determined so that the line is read in each direction.   The image processing apparatus according to claim 1, wherein the acquisition unit acquires information of the streak image by reading a reading position of the scanner in advance.   The determining means determines how to set the sheet on which the chart image is formed by the scanner so that a conveyance direction when the scanner reads an image is different from the first direction. The image processing apparatus according to claim 1, which is characterized. An image processing method in an image processing apparatus having an image forming unit that forms an image and a scanner that reads the image line by line,
An acquisition step of acquiring a feature amount of a streak-like image that is detected from image data acquired by reading the image line by line with the scanner and extends in a direction along a first direction of the image;
The direction in which the paper is installed in the scanner installation unit in order to read the paper on which the chart image is formed by the image forming unit using the scanner, using the feature amount of the streak-like image acquired in the acquisition step. A decision step to decide;
A detection step of reading the chart image formed on the paper set in the direction determined in the determination step for each line by the scanner, and detecting a streak-like image in the chart image from the read image data;
An image processing method comprising:   A program for causing a computer to execute the image processing method according to claim 9.

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