JP2021184512A - Image forming apparatus - Google Patents

Abstract

To specify the cause of an abnormality even if the cause of the abnormality has been difficult to be specified before.SOLUTION: An image forming apparatus 1 comprises: an image forming unit 125 that forms, on a recording material, an image based on image original data to be input; and an abnormality detection unit 209 that detects an abnormality in the image, and the image forming apparatus has: a control unit 123 that causes the image forming unit to form a predetermined image pattern corresponding to the abnormality detected by the abnormality detection unit; a pattern reading unit 201 that reads the image pattern; and a cause specification unit 209 that specifies the cause of the abnormality based on pattern read data obtained through the reading performed by the pattern reading unit.SELECTED DRAWING: Figure 2

Description

The present invention relates to an image forming apparatus.

Conventionally, an image forming apparatus including an image forming unit for forming an image based on input image source data on a recording material and an abnormality detecting unit for detecting an abnormality on the image is known.

For example, in Patent Document 1, an image of a printed matter (a recording material on which an image is formed based on input image source data) formed by an image forming unit is read, and quality inspection (abnormality detection) of the image is performed. The image forming apparatus is disclosed. This image forming apparatus stores information on defects (abnormalities) detected in the quality inspection (defect page, position on the page, number of defects, defect level, etc.) and displays it on the operation panel.

However, with the conventional image forming apparatus, even if the abnormality generated on the image can be detected, it is difficult to identify the cause of the abnormality.

In order to solve the above-mentioned problems, the present invention includes an image forming unit that forms an image based on input image source data on a recording material, and an abnormality detecting unit that detects an abnormality on the image. An image forming apparatus, a control unit for forming a predetermined image pattern corresponding to an abnormality detected by the abnormality detecting unit on the image forming unit, a pattern reading unit for reading the image pattern, and a pattern reading unit. It is characterized by having a cause specifying unit for identifying the cause of the abnormality based on the pattern reading data read by.

According to the present invention, it is possible to identify the cause of an abnormality even if it is an abnormality for which it has been difficult to identify the cause in the past.

The schematic diagram which shows an example of the image formation system of an embodiment. Block diagram showing an example of the configuration of the image formation system The schematic diagram which shows an example of the reading part of the printed matter inspection apparatus which constitutes the image formation system. The figure which shows an example of the defect information of an embodiment. The figure which shows an example of the detailed information of an embodiment. (A) to (d) are explanatory views showing image defects (abnormalities) that may occur on a printed matter on which a printed image is formed. The flowchart which shows an example of the processing procedure of defect detection (abnormality detection) performed by the printed matter inspection apparatus. (A) is an explanatory diagram showing a procedure for determining whether or not there is defect information satisfying the condition that the defect level is equal to or higher than a predetermined level threshold value. (B) is an explanatory diagram showing a procedure for determining whether or not there is defect information satisfying the condition that the number of defects is equal to or greater than a predetermined number threshold value. The flowchart which shows an example of the processing procedure of the cause diagnosis performed by the printed matter inspection apparatus. An explanatory diagram showing an example of a diagnostic image pattern for diagnosing the cause of white streaks extending in the recording material transport direction. Explanatory drawing which shows an example of the image pattern for diagnosis in which the defect (abnormality) of a white streak occurred. (A) and (b) are explanatory views showing an example of the method of notifying the user of the result of the cause diagnosis of the defect (abnormality) which occurred on the printed matter.

Hereinafter, an embodiment of the image forming apparatus according to the present invention will be described.
FIG. 1 is a schematic diagram showing an example of the image forming apparatus of the present embodiment.
The image forming apparatus of this embodiment is an image forming system 1 composed of a printing apparatus 100, a printed matter inspection apparatus 200, and a stacker 300. Of course, a single device may be configured in which the printing device 100, the printed matter inspection device 200, and the stacker 300 are incorporated in a single device.

The printing apparatus 100 includes an operation panel 101 as a notification unit, photoconductor drums 103Y, 103M, 103C, 103K, a transfer belt 105, a secondary transfer roller 107, a paper feed unit 109, a transfer roller pair 111, and the like. A fixing roller 113 and an inversion path 115 are provided.

The operation panel 101 functions as an operation unit and a display unit for inputting various operations to the image forming system 1 and displaying various screens.

In each of the photoconductor drums 103Y, 103M, 103C, and 103K, a toner image is formed by performing an image forming process (charging step, exposure step, developing step, transfer step, and cleaning step), and the formed toner image is formed. Transfer to the transfer belt 105. In this embodiment, a yellow toner image is formed on the photoconductor drum 103Y, a magenta toner image is formed on the photoconductor drum 103M, a cyan toner image is formed on the photoconductor drum 103C, and the cyan toner image is formed on the photoconductor drum 103K. It is assumed that a black toner image is formed, but the present invention is not limited to this.

The transfer belt 105 transfers a toner image (full-color toner image) superimposed and transferred from the photoconductor drums 103Y, 103M, 103C, and 103K to the secondary transfer position of the secondary transfer roller 107. In the present embodiment, the yellow toner image is first transferred to the transfer belt 105, and then the magenta toner image, the cyan toner image, and the black toner image are sequentially superimposed and transferred, but the present invention is limited to this. It is not something that will be done.

The paper feed unit 109 accommodates a plurality of recording papers as recording materials in an overlapping manner, and feeds the recording papers.

The transport roller pair 111 transports the recording paper fed by the paper feed unit 109 on the transport path a in the direction of the arrow s.

The secondary transfer roller 107 collectively transfers the full-color toner image conveyed by the transfer belt 105 onto the recording paper conveyed by the transfer roller pair 111 at the secondary transfer position.

The fixing roller 113 fixes the full-color toner image on the recording paper by heating and pressurizing the recording paper on which the full-color toner image is transferred.

In the case of single-sided printing, the printing device 100 discharges the printed matter, which is the recording paper on which the full-color toner image is fixed, to the printed matter inspection device 200. On the other hand, in the case of double-sided printing, the printing apparatus 100 sends the recording paper on which the full-color toner image is fixed to the inversion path 115.

The inversion path 115 reverses the front and back surfaces of the recording paper by switching back the sent recording paper, and conveys the paper in the direction of arrow t. The recording paper conveyed by the inversion pass 115 is retransmitted by the transfer roller pair 111, the full-color toner image is transferred to the surface opposite to the previous one by the secondary transfer roller 107, and the full-color toner image is fixed by the fixing roller 113 as printed matter. , The paper is discharged to the printed matter inspection device 200.

The printed matter inspection device 200 includes reading units 201A and 201B. The reading unit 201A electronically reads one side of the printed matter discharged from the printing device 100, and the reading unit 201B electronically reads the other side of the printed matter discharged from the printing device 100. The reading units 201A and 201B can be realized by, for example, a line scanner or the like. Then, the printed matter inspection device 200 discharges the read printed matter to the stacker 300.

The stacker 300 includes a tray 301. The stacker 300 stacks the printed matter discharged by the printed matter inspection device 200 on the tray 301.

FIG. 2 is a block diagram showing an example of the configuration of the image forming system 1 of the present embodiment.
As shown in FIG. 2, the printing apparatus 100 includes a RIP (Raster Image Processor) unit 121, a printing control unit 123 as a control unit, and a printing unit 125 as an image forming unit. The printed matter inspection device 200 includes a reading unit 201 that functions as a pattern reading unit and an image reading unit, an acquisition unit 203, a master image generation unit 205, a buffer 207, an abnormality detection unit, and an inspection unit 209 as a cause identification unit. , A storage unit 211 is provided. In this embodiment, it is assumed that the printing device 100 and the printed matter inspection device 200 are connected by a local interface such as USB (Universal Serial Bus) or PCIe (Peripheral Component Interconnect Express). The connection form between the printing device 100 and the printed matter inspection device 200 is not limited to this, and may be connected by, for example, a network such as a LAN (Local Area Network).

The RIP unit 121 receives print data as image source data from an external device such as a host device, and generates an original image (which is the basis of printing) of a printed matter generation source from the received print data. Specifically, the RIP unit 121 RIP-processes the print data and generates a RIP image (bitmap image) as the original image.

In the present embodiment, the print data is configured to include data described in a page description language (PDL) such as PostScript (registered trademark), image data in TIFF (Tagged Image File Format) format, and the like. However, it is not limited to this. Further, in the present embodiment, the original image is CMYK RIP image data, and each pixel of each C (Cyan), M (Magnenta), Y (Yellow), and K (black: Black) RIP image data is 2 bits. It is assumed that the value is 1200 dpi, but the data is not limited to this.

The print control unit 123 transmits the print job information specified from the data described in the page description language and the RIP image generated by the RIP unit 121 to the printed matter inspection device 200, and also transmits the RIP image to the print unit 125. do. Further, the print control unit 123 uses the defect information transmitted (feedback) from the printed matter inspection device 200 to specify, for example, the output destination of the printed matter that has not passed the quality inspection for the stacker 300 and the quality. Marking of printed matter that has not passed the inspection is performed, and replacement printing is instructed to the printing unit 125.

The RIP unit 121 and the print control unit 123 may be realized by software, for example, by causing a processing device such as a CPU (Central Processing Unit) to execute a program, or may be realized by software, such as an IC (Integrated Circuit) or an ASIC (Integrated Circuit). It may be realized by hardware such as Application Specific Integrated Circuit), or it may be realized by using software and hardware together.

The printing unit 125 executes a printing processing process such as an image forming process, prints a printed image based on the RIP image on recording paper, and produces a printed matter. In the present embodiment, the printing unit 125 is realized by the photoconductor drums 103Y, 103M, 103C, 103K, the transfer belt 105, the secondary transfer roller 107, the fixing roller 113, and the like, but is not limited thereto. As described above, in the present embodiment, the image is printed by the electrophotographic method, but the present invention is not limited to this, and the image may be printed by the inkjet method.

The reading unit 201 reads the printed matter generated by the printing unit 125 to generate image reading data. Specifically, as shown in FIG. 3, the reading unit 201 captures the printed matter P illuminated by the illuminating unit 201a by the imaging unit 201b, so that the printed matter P on which the printed image based on the RIP image is printed can be obtained from the printed matter P. The printed image is electronically read to generate image reading data. In the present embodiment, the reading unit 201 is composed of two reading units 201A and 201B. Further, in the present embodiment, the image reading data is RGB image data, and each pixel of each of the image data of R, G, and B is 8 bits and 200 dpi, but the present invention is not limited to this. ..

The acquisition unit 203 acquires the data of the original image of the generation source of the printed matter generated by the print unit 125 and the information of the print job. Specifically, the acquisition unit 203 acquires RIP image data of each of C, M, Y, and K from the print control unit 123 of the printing apparatus 100.

The master image generation unit 205 generates master image data based on the data of the original image acquired by the acquisition unit 203. Specifically, the master image generation unit 205 performs various image processing such as multi-value conversion processing, smoothing processing, resolution conversion processing, and color conversion processing on the data of the original image acquired by the acquisition unit 203. , Generate master image data. The master image data is RGB image data, and each pixel of each of the image data of R, G, and B is assumed to be 8 bits of 200 dpi, but the master image data is not limited to this.

The acquisition unit 203 and the master image generation unit 205 may be realized by, for example, a processing device such as a CPU, that is, software, or hardware such as an IC or ASIC. Alternatively, it may be realized by using software and hardware together.

The buffer 207 stores the master image data generated by the master image generation unit 205. Then, when the image reading data is generated by the reading unit 201, the buffer 207 outputs the master image data used for the inspection to the inspection unit 209. The buffer 207 can be realized by, for example, a DRAM (Dynamic Random Access Memory) or the like.

The inspection unit 209 compares the image reading data generated by the reading unit 201 with the master image data generated by the master image generation unit 205, and inspects the quality of the printed matter generated by the printing apparatus 100 (abnormality detection). I do.

Specifically, the inspection unit 209 compares the image reading data generated by the reading unit 201 with the master image data output from the buffer 207 on a pixel-by-pixel basis, and calculates the difference value of the pixel values of 8 bits for each RGB color for each pixel. Calculate to. Then, the inspection unit 209 performs a quality inspection (abnormality detection) of the printed matter generated by the printing apparatus 100 based on the magnitude relationship between the difference value for each pixel and the threshold value for quality inspection, and obtains the inspection result. Using the print job information acquired by the unit 203, defect information (abnormality information) related to defects (abnormalities) in the printed matter is generated and stored in the storage unit 211. The storage unit 211 can be realized by, for example, an HDD (Hard Disk Drive) or an SSD (Solid State Drive).

The inspection unit 209 may, for example, have a processing device such as a CPU execute a program, that is, may be realized by software, may be realized by hardware such as an IC or ASIC, or may be realized by software and hardware. It may be realized by using hardware together.

FIG. 4 is a diagram showing an example of defect information of the present embodiment.
In the example shown in FIG. 4, defect information for one print job is shown. In addition, the print job of FIG. 4 is instructed to perform printing based on the original image a plurality of times and to produce a plurality of copies of the same printed matter. The defect information is information associated with a part, a page, front and back, paper size, paper thickness, number of defects, defect level, scanned image (image scanned data), thumbnail image, and detailed information. In the example shown in FIG. 4, the description of the scanned image (image scanned data), the thumbnail image, and the value of the detailed information is omitted.

The sections, pages, and front and back indicate which page of the printed matter the scanned image (image reading data) is the front or back of the printed matter. The number of defects indicates the number of defects detected from the image reading data. The defect level indicates the level of defects in the entire defects detected from the image reading data, and is used as a criterion for quality inspection.

The scanned image is the image scanned data used for the quality inspection of the inspection unit 209, and is the image scanned data generated by the scanning unit 201. The thumbnail image is image data obtained by reducing the resolution of the image reading data. In the present embodiment, the thumbnail image is an image in which the image reading data of 200 dpi is reduced to 25 dpi, but the thumbnail image is not limited to this.

The detailed information is information about the details of each defect detected from the image reading data. FIG. 5 is a diagram showing an example of detailed information of the present embodiment. In the example shown in FIG. 5, the detailed information is information in which the part, the page, the front and back, the defect number, the defect type, the main scanning direction position coordinates, the sub-scanning direction position coordinates, the defect density, and the defect size are associated with each other. There is.

The defect number is a number for identifying each detected defect (abnormality). The defect type is the type of defect indicated by the defect number. Specifically, the types of defects (abnormalities) include, for example, spots generated on the background of printed matter, background stains generated on the background of printed matter, main scanning direction and sub-scanning direction (recording material transport direction). Examples include streaks that extend to.

The main scanning direction position coordinates are the position coordinates in the main scanning direction of the defect indicated by the defect number. The sub-scanning direction position coordinates are the position coordinates of the defect indicated by the defect number in the sub-scanning direction. That is, the main scanning direction position coordinates and the sub-scanning direction position coordinates indicate the positions of defects on the image reading data. The defect density is the density of the defect indicated by the defect number. The size of the defect is the size of the defect indicated by the defect number.

6 (a) to 6 (d) are explanatory views showing defects (abnormalities) of an image that may occur on a printed matter on which a printed image G is formed.
FIG. 6A is a diagram showing an example of a printed matter P in which medium-sized spots E1, small spots E2, and ground stains E3 are generated, and FIG. 6B is an example of a printed matter P in which large spots E4 are generated. 6 (c) is a diagram showing an example of a printed matter P in which a white streak E5 extending in the recording material transport direction is generated, and FIG. 6 (d) is different from FIG. 6 (b). It is a figure which shows an example of the printed matter P which generated the large pot E6 at the position.

FIG. 7 is a flowchart showing an example of a processing procedure for defect detection (abnormality detection) performed by the printed matter inspection device 200 of the present embodiment.
The acquisition unit 203 acquires the image data of the original image of the generation source of the printed matter generated by the print unit 125 and the information of the print job (S101). When the user inputs an inspection start instruction from the operation panel 101 to the printed matter inspection device 200 (S102), first, the master image generation unit 205 generates master image data based on the data of the original image acquired by the acquisition unit 203. (S103).

On the other hand, the reading unit 201 reads the printed matter generated by the printing unit 125 to generate image reading data (S104). Then, the inspection unit 209 compares the image reading data generated by the reading unit 201 with the master image generated by the master image generation unit 205, inspects the quality of the printed matter generated by the printing apparatus 100, and inspects the quality of the printed matter, which is defective. Generate information (step S109).

Then, the processes of steps S103 to S105 are repeated until the quality of all pages of the printed matter is inspected (No in S106), and the quality of all pages of the printed matter is inspected (abnormality detection) (Yes in S106). Stores the generated defect information in the storage unit 211 (S107).

In the flowchart shown in FIG. 7, an example in which the processes of steps S103 to S105 are performed for each page has been described, but the processes of steps S103 to S105 may be performed for all pages at once. Further, the processing order of steps S103 and S104 may be exchanged.

After storing the defect information for all pages of the printed matter in the storage unit 211, the inspection unit 209 then refers to the defect information stored in the storage unit 221 and the defect level is as shown in FIG. 8A. It is determined whether or not there is defect information satisfying the condition that it is equal to or higher than a predetermined level threshold value (S108). When there is defect information whose defect level is equal to or higher than a predetermined level threshold value (Yes in S108), a cause diagnosis for identifying the cause of occurrence of the type of defect (abnormality) in the defect information is executed (S110).

Further, the inspection unit 209 refers to the defect information stored in the storage unit 221 and, as shown in FIG. 8B, is there any defect information satisfying the condition that the number of defects is equal to or more than a predetermined number threshold value? Judge whether or not (S109). When there is defect information in which the number of defects is equal to or greater than a predetermined number threshold value (Yes in S109), a cause diagnosis for identifying the cause of occurrence of the type of defect (abnormality) in the defect information is executed (S110).

In the flowchart shown in FIG. 7, an example in which the processing of steps S108 to S110 is performed after the defect information for all pages of the printed matter is stored in the storage unit 211 has been described, but the quality inspection of each page of the printed matter is completed. The defect information may be stored in the storage unit 211 each time, and the processes of steps S108 to S110 may be performed. In this case, the cause of the defect (abnormality) generated on the printed matter formed during the continuous image forming operation can be diagnosed during the continuous image forming operation. The processing order of steps S108 and S109 may be exchanged.

FIG. 9 is a flowchart showing an example of a process procedure for cause diagnosis performed by the printed matter inspection device 200 of the present embodiment.
When the cause diagnosis is to be executed in the above-mentioned defect detection (abnormality detection), the inspection unit 209 first acquires the type of the defect (abnormality) to be identified as the cause (S201). Then, an instruction for forming a predetermined diagnostic image pattern corresponding to the acquired defect to the printing unit 125 is transmitted to the printing control unit 123 of the printing apparatus 100, and the diagnostic image pattern is created (S202). .. The image data of each diagnostic image pattern for each type of defect is stored in, for example, the storage unit 211, and the inspection unit 209 reads out the image data of the diagnostic image pattern corresponding to the acquired defect from the storage unit 211. It is transmitted to the print control unit 123.

The diagnostic image pattern thus created is output to the printed matter inspection device 200 as a printed matter, for example, and is read by the reading unit 201 (S203). Although an example of reading a diagnostic image pattern by using a reading unit 201 that reads a printed image on a printed matter will be described here, the diagnostic image pattern may be read by a reading unit different from the reading unit 201. .. For example, another reading unit may be arranged at a position facing the transfer belt 105 to read the diagnostic image pattern on the transfer belt 105. In this case, since it is not necessary to transfer the diagnostic image pattern onto the recording paper, it is possible to eliminate waste of the recording paper.

The pattern reading data generated by reading the diagnostic image pattern by the reading unit 201 is sent to the inspection unit 209. The inspection unit 209 compares the pattern reading data with the image data of the diagnostic image pattern to detect defects (abnormalities) occurring on the diagnostic image pattern (step S204). Then, the inspection unit 209 executes a process of identifying the cause of the defect from the detection result of the defect (S205).

In the present embodiment, in this process, the color in which the defect is generated is specified (which photoconductor drum 103Y, 103M, 103C, 103K the defect is generated in, etc.), and the member or device in which the defect is generated is specified (in this process). At least one of the photoconductor drum, transfer belt, charging process, exposure process, developing process, transfer process, etc.) and the position where the defect is generated (main scanning direction position, sub-scanning direction position, etc.) is specified.

FIG. 10 is an explanatory diagram showing an example of a diagnostic image pattern for diagnosing the cause of the white streaks E5 extending in the recording material transport direction shown in FIG. 6 (c).
The diagnostic image pattern illustrated in FIG. 10 has two output methods, analog output and digital output, on each photoconductor drum 103Y, 103M, 103C, 103K, and has a high image density and a low image extending in the main scanning direction, respectively. Two strip patterns of density are arranged side by side in the sub-scanning direction (recording material transport direction), and these are transferred from each photoconductor drum 103Y, 103M, 103C, 103K so as not to overlap on the transfer belt and created on the recording paper. It was done.

By creating an independent diagnostic image pattern for each color as in the present embodiment, it is possible to identify on which color the photoconductor drums 103Y, 103M, 103C, 103K the defect (abnormality) occurs. Can be done.

Further, by using a band-shaped pattern extending over the main scanning direction as the diagnostic image pattern as in the present embodiment, it is possible to specify at which position in the main scanning direction the defect (abnormality) occurs.

Further, in the present embodiment, the diagnostic image pattern is output by two output methods, analog output and digital output. The analog output here is an output method for creating an image pattern without performing an exposure process. For example, two band patterns having a high image density and a low image density are created by adjusting a charging bias and a development bias. do. On the other hand, the digital output is an output method for forming an image pattern by forming a latent image pattern by an exposure process in the same manner as a normal image forming process. By creating a diagnostic image pattern using these two types of output methods, it is possible to identify whether or not the cause of the defect (abnormality) is in the exposure process.

Further, by using two diagnostic image patterns of high image density and low image density as in the present embodiment, it is possible to specify whether the cause of the defect (abnormality) is in the developing process or the charging process. be able to.

Table 1 below is a table showing the relationship between the diagnostic image pattern in which the defect (abnormality) of the white streaks extending in the recording material transport direction has occurred among the created diagnostic image patterns and the cause of the white streaks. be.

In the present embodiment, as shown in Table 1, when a defect of white streaks occurs in a diagnostic image pattern having high image density in analog output and digital output, it is caused by the development process in the photoconductor drum of the color. To specify. Further, when a defect of white streaks occurs in a diagnostic image pattern having a low image density in analog output and digital output, it is identified that the cause is the charging process in the photoconductor drum of the color. If a white streak defect occurs in the low image density diagnostic image pattern at the digital output and no white streak defect occurs in the low image density diagnostic image pattern at the analog output, the color is exposed to light. Identify the cause in the exposure process on the body drum.

FIG. 11 is an explanatory diagram showing an example of a diagnostic image pattern in which a defect (abnormality) of a white streak has occurred in the present embodiment.
As shown in FIG. 11A, when a white streak defect (abnormality) is detected on the low density image pattern of K in the digital output, the cause of the white streak defect (abnormality) generated on the printed matter is It can be specified that it exists in the exposure process of K. Further, as shown in FIG. 11B, when a white streak defect (abnormality) is detected on the high-density image pattern of K in the analog output and the digital output, the white streak defect (abnormality) generated on the printed matter is detected. ) Can be identified as existing in the developing process of K.

It should be noted that each image pattern for each type of defect may be any one suitable for identifying the cause of the corresponding defect. In particular, for each defect, the color that caused the defect is specified (which photoconductor drum 103Y, 103M, 103C, 103K the defect occurred on, etc.), and the member or device that caused the defect is specified ( Easily identify at least one of the photoconductor drum, transfer belt, charging process, exposure process, developing process, transfer process, etc.) and the location where the defect occurred (main scanning direction position, sub-scanning direction position, etc.). It is preferable that the image pattern is to be used.

After identifying the cause of the defect (abnormality) that has occurred on the printed matter in the above manner, the diagnosis result (cause of the identified defect) is notified to the user or the maintenance company (the process is performed). S206). As a method of notifying the user, for example, as shown in FIG. 12A, information indicating the diagnosis result is displayed on the operation panel 101, or as shown in FIG. 12B, the diagnosis result is shown. Information is displayed on the display of a user terminal (smartphone, etc.) via a communication network. By immediately notifying the user of the result of the cause diagnosis in this way, it is possible to provide an image forming apparatus having excellent usability.

The above description is an example, and the effect peculiar to each of the following aspects is exhibited.
[First aspect]
The first aspect is an image forming unit (for example, a printing unit 125) that forms an image (for example, a printed image) based on input image source data (for example, print data) on a recording material (for example, a recording paper), and the image. An image forming apparatus (for example, an image forming system 1) provided with an abnormality detecting unit (for example, an inspection unit 209) for detecting the above abnormality, and a predetermined image pattern corresponding to the abnormality detected by the abnormality detecting unit. The abnormality is based on a control unit (for example, a print control unit 123) for forming the image in the image forming unit, a pattern reading unit (for example, reading unit 201) for reading the image pattern, and pattern reading data read by the pattern reading unit. It is characterized by having a cause specifying unit (for example, an inspection unit 209) for specifying the cause of the above.
In this embodiment, a predetermined image pattern corresponding to the abnormality detected by the abnormality detection unit is formed in the image forming unit, and the cause identification unit is abnormal based on the pattern reading data read by the pattern reading unit. Identify the cause of. Since the content of the image pattern does not depend on the input image source data, it can be suitable for identifying the cause of the abnormality.
For example, when a streak (abnormality) extending in the recording material transport direction occurs on a color image formed by an electrophotographic method based on input image source data, the streak on the image causes the streak. , It may not be possible to identify which color the image forming part is caused by. Even in this case, if the image pattern does not depend on the input image source data, for example, by creating an independent image pattern for each color, the cause of the streak is caused by the image forming portion of which color. It is possible to identify whether it is. Further, from the streaks on the image based on the input image source data, it is difficult to identify whether the cause of the streaks exists in, for example, the charging process or the developing process. In this case as well, if the image pattern does not depend on the input image source data, for example, by creating an image pattern having a different image density, whether the cause of the streak exists in the charging process or the developing process. Can be identified.
Therefore, according to this aspect, even if the abnormality cannot be identified on the image based on the input image source data, the cause of the abnormality can be identified.

[Second aspect]
In the second aspect, in the first aspect, the image reading unit (for example, reading unit 201) for reading the image is provided, and the abnormality detecting unit includes the image source data of the image and the image reading data read by the image reading unit. It is characterized in that an abnormality on the image is detected based on the above.
According to this, it is possible to detect an abnormality on an image by a simple method.

[Third aspect]
The third aspect has a storage unit 211 that cumulatively stores the abnormality detection data (for example, defect information) detected by the abnormality detection unit in the first or second aspect, and the control unit is stored in the storage unit. When the stored abnormality detection data satisfies a predetermined condition, the image forming unit is formed with the image pattern for the abnormality corresponding to the predetermined condition.
According to this, the cause of the continuously occurring abnormality can be appropriately identified.

[Fourth aspect]
A fourth aspect is characterized in that, in any one of the first to third aspects, the control unit causes the image forming unit to form the image pattern while continuing the continuous image forming operation.
According to this, the cause of the abnormality can be identified even while the continuous image forming operation is continued, and the cause of the abnormality can be notified to the user or the maintenance company more quickly.

[Fifth aspect]
The fifth aspect is characterized in that, in any one of the first to fourth aspects, the notification unit (for example, the operation panel 101) for notifying the abnormality information including the cause specified by the cause identification unit is provided.
According to this, the cause of the abnormality can be notified to the user or the maintenance company.

[Sixth aspect]
In the sixth aspect, in any one of the first to fifth aspects, the image forming unit uses image materials (for example, toners) of a plurality of colors different from each other on the recording material based on the input image source data. The image pattern is characterized by including a plurality of independent image patterns for each color.
According to this aspect, when an abnormality occurs on a color image formed by image materials of a plurality of colors based on input image source data, which color image material is the cause of the abnormality? Can be done.

[7th aspect]
A seventh aspect is characterized in that, in any one of the first to sixth aspects, the image forming unit forms an image by an electrophotographic method.
According to this aspect, in the electrophotographic method in which it is difficult to identify the cause of the abnormality, the cause of the abnormality can be specified.

[8th aspect]
An eighth aspect is characterized in that, in the seventh aspect, the image pattern includes a plurality of image patterns having different image densities.
From the abnormality on the image based on the input image source data, it is often difficult to identify whether the cause of the abnormality is, for example, in the charging process or in the developing process. Even in this case, according to this aspect, by creating a plurality of image patterns having different image densities, as described above, whether the cause of the abnormality exists in the charging process or the developing process. Can be specified.

[9th aspect]
A ninth aspect is characterized in that, in the seventh or eighth aspect, the image pattern includes an image pattern formed by performing an exposure step and an image pattern formed without performing an exposure step. It is something to do.
From the abnormality on the image based on the input image source data, it is often difficult to identify whether or not the cause of the abnormality exists in the exposure process. Even in this case, according to this aspect, by creating the image pattern formed by performing the exposure step and the image pattern formed by performing the exposure step, as described above, the image pattern is formed. It is possible to identify whether or not the cause of the abnormality exists in the exposure process.

[10th aspect]
A tenth aspect is characterized in that, in any one of the first to ninth aspects, the abnormality includes an abnormality in which a streak extending in the recording material transport direction is generated.
According to this, it is possible to identify the cause of the streak extending in the recording material transport direction in which it is difficult to identify the cause of the abnormality.

1: Image forming system 100: Printing device 101: Operation panel 103: Photoreceptor drum 105: Transfer belt 107: Secondary transfer roller 109: Paper feed section 111: Transfer roller pair 113: Fixing roller 115: Inversion path 121: RIP section 123: Print control unit 125: Printing unit 200: Printed matter inspection device 201: Reading unit 201a: Lighting unit 201b: Imaging unit 203: Acquisition unit 205: Master image generation unit 207: Buffer 209: Inspection unit 211: Storage unit 221: Storage Part 300: Stacker 301: Tray

Japanese Unexamined Patent Publication No. 2016-55525

Claims (10)

An image forming unit that forms an image based on the input image source data on the recording material,
An image forming apparatus including an abnormality detecting unit for detecting an abnormality on an image.
A control unit that causes the image forming unit to form a predetermined image pattern corresponding to the abnormality detected by the abnormality detecting unit.
A pattern reading unit that reads the image pattern,
An image forming apparatus comprising a cause specifying unit for identifying the cause of the abnormality based on the pattern reading data read by the pattern reading unit. In the image forming apparatus according to claim 1,
It has an image reading unit that reads the image, and has an image reading unit.
The abnormality detecting unit is an image forming apparatus characterized in that it detects an abnormality on the image based on the image source data of the image and the image reading data read by the image reading unit. In the image forming apparatus according to claim 1 or 2.
It has a storage unit that cumulatively stores the abnormality detection data detected by the abnormality detection unit.
The control unit is an image forming apparatus, characterized in that, when the abnormality detection data stored in the storage unit satisfies a predetermined condition, the image forming unit forms the image pattern for the abnormality corresponding to the predetermined condition. .. The image forming apparatus according to any one of claims 1 to 3.
The control unit is an image forming apparatus characterized in that the image pattern is formed on the image forming unit while continuing the continuous image forming operation. The image forming apparatus according to any one of claims 1 to 4.
An image forming apparatus comprising a notification unit for notifying abnormal information including a cause specified by the cause identification unit. The image forming apparatus according to any one of claims 1 to 5.
The image forming unit forms an image on a recording material using image materials of a plurality of colors different from each other based on the input image source data.
The image forming apparatus is characterized in that the image pattern includes a plurality of independent image patterns for each of the colors. The image forming apparatus according to any one of claims 1 to 6.
The image forming unit is an image forming apparatus characterized in that an image is formed by an electrophotographic method. In the image forming apparatus according to claim 7,
The image forming apparatus is characterized in that the image pattern includes a plurality of image patterns having different image densities. In the image forming apparatus according to claim 7 or 8.
The image forming apparatus is characterized in that the image pattern includes an image pattern formed by performing an exposure step and an image pattern formed without performing an exposure step. The image forming apparatus according to any one of claims 1 to 9.
The image forming apparatus is characterized in that the abnormality includes an abnormality in which a streak extending in the recording material transport direction is generated.

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