JP2016061659A - Printed matter inspection device, printed matter inspection system, and printed matter inspection method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a printed matter inspection device, a printed matter inspection system, and a printed matter inspection method with which it is possible to inspect the quality of printed matter correctly even when correspondence between the inspection image of printed matter and a master image breaks down when inspecting the quality of printed matter.SOLUTION: The printed matter inspection device comprises: a master image generation unit 203 for generating, for each original image of each page constituting printed matter, a first master image and a second master image on the basis of the original image; a read unit 207 for reading the printed matter and generating a first inspection image and a second inspection image for each page; a search unit 213 for searching, for each second inspection image, a plurality of second master images for the second master image that resembles the second inspection image; and an inspection unit 209 for comparing, for each first inspection image, the first inspection image and the first master image of the second master image that resembles the second inspection image of the first inspection image, and inspecting the quality of the printed matter.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a printed matter inspection apparatus, a printed matter inspection system, and a printed matter inspection method.

  In printing that requires high quality such as production printing, quality inspection for printed matter is required. For example, a printed material inspection system that inspects the quality of a printed material by comparing a master image generated from an original image from which the printed material is generated and an inspection image generated by electrically reading the printed material is known.

  In the printed material inspection system, when the printing device that prints the printed material and the printed material inspection device that inspects the printed material are different devices that are not connected by the paper conveyance path, the inspector manually prints the printed material printed by the printing device. It must be transported to the printed product inspection device and set in the scanner.

  Here, when the printed matter is composed of a plurality of pages, the inspector scans the printed matter in a predetermined page order so as not to break the correspondence between the inspection image and the master image in the printed matter inspection apparatus. The inspection image must be generated by reading the image with the setting.

  However, since the inspector has to manually transport and set the printed matter printed by the printing apparatus to the printed matter inspection apparatus, there is a possibility that an error in setting the printed matter, a page change, a page missing, etc. may occur. There is.

  In this case, since the printed material cannot be set in a predetermined page order, the inspection image is not generated in the predetermined page order, the correspondence with the master image is broken, and the quality of the printed material can be correctly inspected. Can not.

  Here, for example, in Japanese Patent Laid-Open No. 2004-228688, depending on the print mode, the printed matter is not printed in the order of pages. Therefore, by inputting the corresponding reference image in the page printing order, the correspondence between the read image of the printed matter and the reference image is shown. Techniques for keeping are disclosed.

  However, the technique disclosed in Patent Document 1 merely takes a correspondence between a read image of a printed matter and a reference image by inputting corresponding reference images in the order of printing of pages. Therefore, in the technique disclosed in Patent Document 1, when the printed material cannot be read in a predetermined page order, such as a change of pages after printing of the printed material, the correspondence between the read image of the printed material and the master image is maintained. And the quality of the printed matter cannot be correctly inspected.

  The present invention has been made in view of the above circumstances, and when inspecting the quality of a printed matter, the quality of the printed matter can be correctly inspected even if the correspondence between the inspection image of the printed matter and the master image is broken. An object of the present invention is to provide a printed matter inspection apparatus, a printed matter inspection system, and a printed matter inspection method.

  In order to solve the above-described problems and achieve the object, the printed matter inspection apparatus according to one aspect of the present invention provides a first master image and a corresponding one for each original image of each page constituting the printed matter. A master image generation unit that generates a second master image having a resolution lower than that of the first master image, and a second inspection having a resolution lower than that of the first inspection image and the first inspection image for each page by reading the printed matter. A reading unit that generates an inspection image; a search unit that searches for a second master image similar to the second inspection image from the plurality of second master images for each second inspection image; and the first For each inspection image, an inspection unit that compares the first inspection image with a first master image of a second master image similar to the second inspection image of the first inspection image, and inspects the quality of the printed matter; Is provided.

  According to the present invention, when the quality of a printed matter is inspected, the quality of the printed matter can be correctly inspected even if the correspondence between the read image of the printed matter and the master image is broken.

FIG. 1 is a schematic diagram illustrating an example of a printed matter inspection system according to the present embodiment. FIG. 2 is a block diagram illustrating an example of a configuration of the printing apparatus and the printed matter inspection apparatus according to the present embodiment. FIG. 3 is a diagram illustrating an example of order information according to the present embodiment. FIG. 4 is a diagram illustrating an example of an acquisition order according to this embodiment. FIG. 5 is a flowchart illustrating an example of a procedure flow of a master image generation process performed by the printed matter inspection apparatus according to the present embodiment. FIG. 6 is a flowchart illustrating an example of a procedure flow of an inspection image generation process performed by the printed matter inspection apparatus according to the present embodiment. FIG. 7 is a flowchart illustrating an example of a flow of inspection processing performed by the printed matter inspection apparatus according to the present embodiment. FIG. 8 is a flowchart illustrating an example of a flow of a page consistency determination process performed by the printed matter inspection apparatus according to the present embodiment. FIG. 9 is a flowchart illustrating an example of a flow of an acquisition order update process performed by the printed matter inspection apparatus according to the present embodiment. FIG. 10 is a block diagram illustrating an example of a hardware configuration of the printing apparatus and the printed matter inspection apparatus according to the present embodiment.

  Hereinafter, embodiments of a printed matter inspection apparatus, a printed matter inspection system, and a printed matter inspection method according to the present invention will be described in detail with reference to the accompanying drawings.

  FIG. 1 is a schematic diagram illustrating an example of a printed matter inspection system 1 according to the present embodiment. As shown in FIG. 1, the printed matter inspection system 1 includes a printing apparatus 100, a printed matter inspection apparatus 200, and a stacker 300.

  The printing apparatus 100 includes an operation panel 101, photosensitive drums 103Y, 103M, 103C, and 103K, a transfer belt 105, a secondary transfer roller 107, a paper feeding unit 109, a conveyance roller pair 111, and a fixing roller 113. , A reversing path 115 and a tray 117.

  The operation panel 101 is an operation display unit that performs various operation inputs to the printing apparatus 100 and displays various screens.

  Each of the photosensitive drums 103Y, 103M, 103C, and 103K forms a toner image by performing an image forming process (charging process, exposure process, developing process, transfer process, and cleaning process), and the formed toner image. Is transferred to the transfer belt 105. In this embodiment, a yellow toner image is formed on the photoreceptor drum 103Y, a magenta toner image is formed on the photoreceptor drum 103M, a cyan toner image is formed on the photoreceptor drum 103C, and the photoreceptor drum 103K is formed. Although a black toner image is formed, the present invention is not limited to this.

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

  The paper feeding unit 109 stores a plurality of recording papers, and feeds the recording papers.

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

  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 conveyance 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 pressing the recording paper on which the full color toner image is transferred.

  In the case of single-sided printing, the printing apparatus 100 discharges a printed matter, which is a recording sheet on which a full-color toner image is fixed, to the printed matter inspection apparatus 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 reverse path 115.

  The reverse path 115 reverses the front and back surfaces of the recording paper by switching back the fed recording paper and conveys it in the direction of the arrow t. The recording paper conveyed by the reverse path 115 is re-conveyed by the conveying roller pair 111, the full-color toner image is transferred to the surface opposite to the previous one by the secondary transfer roller 107, fixed by the fixing roller 113, and printed. The paper is discharged to the tray 117.

  The printed matter inspection apparatus 200 includes reading units 207A and 207B, a paper feed tray 230, and an operation panel 240.

  The operation panel 240 is an operation display unit that performs various operation inputs to the printed material inspection apparatus 200 and displays various screens.

  In the paper feed tray 230, when an inspector sets a printed matter generated by the printing apparatus 100 (a printed matter discharged to the tray 117) and an inspection start operation is performed from the operation panel 240, the printed matter is fed.

  The reading unit 207A electronically reads one surface of the printed material fed from the paper feed tray 230, and the reading unit 207B electronically reads the other surface of the printed material fed from the paper feed tray 230. The reading units 207A and 207B can be realized by, for example, a line scanner. Then, the printed matter inspection apparatus 200 discharges the printed matter that has been read to the stacker 300.

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

  FIG. 2 is a block diagram illustrating an example of the configuration of the printing apparatus 100 and the printed matter inspection apparatus 200 according to the present embodiment. As illustrated in FIG. 2, the printing apparatus 100 includes a RIP (Raster Image Processor) unit 121, a print control unit 123, and a printing unit 125. The printed matter inspection apparatus 200 includes an acquisition unit 201, a master image generation unit 203, a buffer 205, a reading unit 207, an inspection unit 209, a storage unit 211, and a search unit 213.

  In this embodiment, it is assumed that the printing apparatus 100 and the printed material inspection apparatus 200 are connected by a local interface such as USB (Universal Serial Bus) or PCIe (Peripheral Component Interconnect Express). The connection form between the apparatus 100 and the printed matter inspection apparatus 200 is not limited to this, and may be connected via a network such as a LAN (Local Area Network).

  The RIP unit 121 receives print data from an external device such as a host device (not shown), and generates an original image (a basis for printing) that is a generation source of each page constituting the printed matter from the received print data. Specifically, the RIP unit 121 performs RIP processing on the print data and generates an RIP image (bitmap image) as an original image.

  In the present embodiment, the print data includes data described in a page description language (PDL) such as PostScript (registered trademark), image data in a TIFF (Tagged Image File Format) format, and the like. However, the present invention is not limited to this. In the present embodiment, the original image is CMYK RIP image data, and each pixel of the RIP image data of C (Cyan), M (Magenta), Y (Yellow), and K (Black) is 2-bit 1200 dpi. It shall be, but 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 each original image generated by the RIP unit 121 to the printed matter inspection apparatus 200 and also transmits each original image to the printing unit 125. Send to. Further, the print control unit 123 uses the defect information transmitted (feedback) from the printed material inspection apparatus 200 to specify, for example, the discharge destination of the printed material that has not passed the quality inspection for the stacker 300 or the quality inspection. The printed material that does not pass is marked, or the printing unit 125 is instructed to perform replacement printing.

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

  The printing unit 125 executes a print processing process such as an image forming process, and prints a print image based on the original image on a recording sheet for each original image, thereby generating a printed material including a plurality of pages. That is, the printing unit 125 generates a printed material based on each original image.

  In this embodiment, the printing unit 125 is realized by the photosensitive drums 103Y, 103M, 103C, and 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 this embodiment, an image is printed by an electrophotographic method, but the present invention is not limited to this, and an image may be printed by an inkjet method.

  In the present embodiment, an example in which the printing apparatus 100 includes the RIP unit 121 will be described. However, the present invention is not limited thereto, and a device independent of the printing apparatus 100 such as a DFE (Digital Front End) may include the RIP unit 121. Also good. In this case, the RIP unit 121 may transmit the print job information and the original image to the printed matter inspection apparatus 200.

  The acquisition unit 201 acquires the original image and print job information of each page constituting the printed matter generated by the printing unit 125. Specifically, the acquisition unit 201 acquires C, M, Y, and K RIP images for each page from the printing apparatus 100 (print control unit 123).

  The master image generation unit 203 generates, for each original image of each page acquired by the acquisition unit 201, a first master image and a second master image having a lower resolution than the first master image based on the original image. .

  Specifically, the master image generation unit 203 performs multi-value conversion processing, smoothing processing, resolution conversion processing, and C, M, Y, and K RIP images of the same page acquired by the acquisition unit 201, and Various image processing such as color conversion processing is performed to generate a first master image and a second master image of the page.

  In the present embodiment, the first master image and the second master image are RGB image data, the first master image is an 8-bit 200 dpi pixel for each of the R, G, and B image data, In the master image, each pixel of R, G, and B image data is 8 bits and 25 dpi, but is not limited thereto.

  The acquisition unit 201 and the master image generation unit 203 may be realized by causing a processing device such as a CPU to execute a program, that is, by software, or by hardware such as an IC or an ASIC. However, software and hardware may be used in combination.

  The buffer 205 stores each first master image and each second master image generated by the master image generation unit 203. Note that the first master image and the second master image generated from the same original image are stored in the buffer 205 in association with each other. The buffer 205 can be realized by, for example, a dynamic random access memory (DRAM).

  The reading unit 207 reads the printed material generated by the printing unit 125 and generates a first inspection image and a second inspection image having a lower resolution than the first inspection image for each page constituting the printed material.

  Specifically, the reading unit 207 electronically reads the print image from the page of the printed material on which the print image based on the original image is printed, and generates a first inspection image and a second inspection image of the page. In the present embodiment, the reading unit 207 is realized by the reading units 207A and 207B.

  In the present embodiment, the first inspection image and the second inspection image are RGB image data, and the first inspection image is an 8-bit 200 dpi pixel in each of the R, G, and B image data. The inspection image is assumed that each pixel of R, G, and B image data is 8 bits and 25 dpi, but is not limited thereto.

  The inspection unit 209 compares the first inspection image generated by the reading unit 207 with the first master image generated by the master image generation unit 203, and inspects the quality of the printed matter generated by the printing apparatus 100.

  Specifically, the inspection unit 209 compares the first inspection image and the first master image in units of pixels, and calculates a difference value between the pixel values of each RGB color 8 bits for each pixel. The inspection unit 209 inspects the quality 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 for quality inspection, and transmits (feeds back) the printed matter to the printing apparatus 100.

  Here, in this embodiment, the inspection unit 209 is generated by the reading unit 207 in order to compare the first inspection image with the corresponding first master image (the first master image having the same original image as the generation source). The first inspection images are acquired in the order in which they are performed, the first master image is acquired from the buffer 205 in the acquisition order based on the generation order of the reading unit 207, and the first inspection image and the first master image are compared in the acquisition order. .

  The generation order of the reading unit 207 means the order determined by the page order and the front / back order set by the inspector at the start of the inspection, but may be changed in the inspection process. Further, the order generated by the reading unit 207 means the order actually generated by the reading unit 207.

  Hereinafter, the generation order and the acquisition order will be described. The generation order and the acquisition order are determined based on the order information stored in the storage unit 211. FIG. 3 is a diagram illustrating an example of order information according to the present embodiment. In the example illustrated in FIG. 3, the order information is a table in which items, setting contents, and setting values are associated with each other. The set value is a value set (selected) by the inspector from the values of the setting contents. The item “page rotation direction” is not related to the generation order and the acquisition order, and will be described later.

  When the item is “page order”, the setting content is “ascending order, descending order”, and the setting value is “ascending order”. When the item is “front / back order”, the setting contents are “front → back, back → front”, and the setting value is “front → back”.

  In this case, since the generation order of the first inspection image of the reading unit 207 is ascending order and front-back page order, the acquisition order of the first master image is also ascending order and front-back page order. That is, the generation order is determined according to the page order setting value and the front / back order setting value of the order information shown in FIG. 3, and the acquisition order is the same order as the generation order.

  FIG. 4 is a diagram illustrating an example of the acquisition order of the present embodiment, and illustrates a case where the number of pages of the printed material is 10. For example, when the generation order is ascending and front and back, the acquisition order is also ascending and front and back pages, so the acquisition order is P1, P2, P3,..., P10. Further, for example, when the generation order is descending and reverse side, the acquisition order is also descending and reverse page order, so the acquisition order is P9, P10, P7,..., P2.

  Accordingly, when the printed matter is set in the printed matter inspection apparatus 200 in the generation order and is read by the reading unit 207, the generation order of the reading unit 207 and the order generated by the reading unit 207 are the same order. The inspection unit 209 can acquire the first master image corresponding to the first inspection image, and can correctly inspect the quality of the printed matter.

  On the other hand, when the printed material is set in the printed material inspection apparatus 200 in an order different from the generation order and is read by the reading unit 207, the generation order of the reading unit 207 is different from the order generated by the reading unit 207. Therefore, the inspection unit 209 cannot acquire the first master image corresponding to the first inspection image, and cannot inspect the quality of the printed matter as it is.

  Therefore, the search unit 213 generates the master image generation unit 203 (stored in the buffer 205) when the compared first inspection image and the first master image are not similar as a result of the comparison by the inspection unit 209. A second master image similar to the second inspection image of the first inspection image is searched from among the plurality of second master images.

  The case where the first inspection image and the first master image are not similar includes a case where the difference value between the pixel values of the first inspection image and the first master image exceeds the first threshold. In addition, the second master image similar to the second inspection image includes a case where the difference value between the pixel values of the second inspection image and the second master image is less than the second threshold. The reason for using the second inspection image and the second master image for the search is to improve the search speed.

  Then, the inspection unit 209 obtains the first master image of the second master image searched by the search unit 213 from the buffer 205, and re-comparates the first inspection image with the first master image. Thereby, even if the correspondence between the first inspection image and the first master image is broken, the quality of the printed matter can be correctly inspected.

  When the inspection unit 209 recomparates the first inspection image, the inspection unit 209 acquires the first inspection image generated next to the first inspection image from the reading unit 207, and the first master recompared in the acquisition order. The next first master image of the image is obtained from the buffer 205 and compared, and the next inspection is performed.

  For example, the generation order is ascending order and front / back page order, and the first inspection image acquired third from the reading unit 207 is not similar to the first master image with the page number “P3”. As a result of the search, the second master image with the page number “P7” is searched (see FIG. 4). In this case, the inspection unit 209 updates the current acquisition position in the acquisition order from the page number “P3” to the page number “P7”, acquires the first master image with the page number “P7”, and acquires the first inspection image. Recompare. For the first inspection image acquired fourth from the reading unit 207, the first master image with the page number “P8” acquired next to the first master image with the page number “P7” is acquired and compared. .

  This is considered that there is a high possibility that the printed matter is set in the printed matter inspecting apparatus 200 in a state where the pages of the printed matter are switched and the seventh page to the tenth page are inserted between the second and third pages of the printed matter. Because it is.

  In addition, the inspection unit 209 has a predetermined number in which the page number of the first master image similar to the first inspection image generated first by the reading unit 207 is different from the page number of the first master image acquired first in the acquisition order. In this case, the acquisition order is updated to the order based on the predetermined number.

  This is because there is a high possibility that the page order of the printed matter is different from the page order and the front / back order determined by the acquisition order.

  For example, when the predetermined number indicates the first page, the inspection unit 209 updates the acquisition order in the ascending order of the page order and the front and back order in the order of front and back (see FIG. 4).

  For example, when the predetermined number indicates the last page, the inspection unit 209 updates the acquisition order in the descending order of the page order and the front / back order in the order of the front and back (see FIG. 4).

  Further, for example, when the predetermined number indicates the next page after the first page, the inspection unit 209 updates the acquisition order in ascending order of page order and front-back order in reverse order (see FIG. 4).

  Further, for example, when the predetermined number indicates the page before the last page, the inspection unit 209 updates the acquisition order in descending order of page order and front-back order in reverse order (see FIG. 4).

  In the present embodiment, assuming that the printed matter may be set in the printed matter inspection apparatus 200 in an order different from the generation order, when the first inspection image and the first master image are not similar, The example in which the search using the second inspection image and the second master image is performed has been described. However, the search using the second inspection image and the second master image is performed from the beginning, and the first inspection image, the first master image, You may make it take correspondence of.

  In this case, every time the second inspection image is generated by the reading unit 207, the search unit 213 selects from the plurality of second master images generated by the master image generation unit 203 (stored in the buffer 205). The inspection unit 209 searches for a second master image similar to the second inspection image, and each time the reading unit 207 generates the first inspection image, the inspection unit 209 similar to the second inspection image of the first inspection image. The first master image of the two master images may be acquired from the buffer 205, the first inspection image may be compared with the acquired first master image, and the quality of the printed material may be inspected.

  The inspection unit 209 and the search unit 213 may be realized by causing a processing device such as a CPU to execute a program, that is, by software, or by hardware such as an IC or an ASIC. The software and hardware may be used in combination. The storage unit 211 can be realized by, for example, an HDD (Hard Disk Drive) or an SSD (Solid State Drive).

  FIG. 5 is a flowchart illustrating an example of a procedure flow of a master image generation process performed by the printed matter inspection apparatus 200 according to the present embodiment.

  First, the master image generation unit 203 generates a first master image of an unprocessed page and stores it in the buffer 205 (step S0401), generates a second master image of the unprocessed page, and generates it in step S0401. The data is stored in the buffer 205 in association with the first master image (step S0402).

  Subsequently, the master image generation unit 203 repeats the processing in steps S0401 to S0402 until all pages are processed (No in step S0403). When all pages are processed (Yes in step S0403), the result is displayed on the operation panel 240. (Step S0404).

  FIG. 6 is a flowchart illustrating an example of the flow of the inspection image generation process performed by the printed matter inspection apparatus 200 according to the present embodiment.

  First, the reading unit 207 reads a printed page, generates a first inspection image, outputs the first inspection image to the inspection unit 209 (step S0501), generates a second inspection image, and outputs the second inspection image to the search unit 213 ( Step S0502). Note that the inspection unit 209 starts the inspection when the first inspection image is output.

  Subsequently, the reading unit 207 repeats the processes in steps S0501 to S0502 until all pages of the printed material are processed (No in step S0503). When all pages are processed (Yes in step S0503), the process ends.

  Note that the inspection image generation process may be executed by selecting a job to be inspected.

  FIG. 7 is a flowchart illustrating an example of a flow of inspection processing performed by the printed matter inspection apparatus 200 according to the present embodiment.

  First, when the first inspection image is generated by the reading unit 207, the inspection unit 209 acquires the first inspection image (step S0601) and follows the acquisition order based on the generation order of the reading unit 207. An image is acquired from the buffer 205 (step S0602).

  Subsequently, the inspection unit 209 performs a difference value calculation process of comparing the acquired first inspection image and the first master image in units of pixels and calculating a difference value of pixel values (step S0603).

  Here, the inspection unit 209 performs a difference value calculation process according to the “page rotation direction” of the order information illustrated in FIG. 3. Specifically, the “page rotation direction” of the order information shown in FIG. 3 is set to “0 degrees, 90 degrees, 180 degrees, 270 degrees” and the set value is “0 degrees”. The unit 209 calculates the difference value by comparing the first master image with the first inspection image in the orientation of 0 degrees, and thereafter, the first master image is in the orientation of 90 degrees, 180 degrees, and 270 degrees. The difference value is calculated by comparing with the inspection image, and the minimum difference value is adopted.

  Subsequently, the inspection unit 209 performs a defect determination process for determining a defect of the corresponding page of the printed material based on the magnitude relationship between the difference value for each pixel and the threshold value for quality inspection (first threshold value) (step S0604). .

  If the difference value for each pixel is equal to or smaller than the first threshold value as a result of the defect determination process (Yes in step S0605), the inspection unit 209 stores the result of the defect determination process (step S0606).

  On the other hand, as a result of the defect determination process, if the difference value for each pixel exceeds the first threshold value (No in step S0605), the inspection unit 209 and the search unit 213 perform a page consistency determination process (step S0608). The page consistency determination process will be described later.

  As a result of the page consistency determination process, if there is a first master image to be recompared (Yes in step S0609) and the first master image to be recompared is unprocessed (No in step S0610), the process proceeds to step S0602. Returning, the inspection unit 209 acquires the first master image to be recompared.

  If there is no first master image to be recompared (No in step S0609), or if the first master image to be recompared has been processed (Yes in step S0610), the generation source of the first inspection image Since the first master image generated from the original image does not exist, the inspection unit 209 stores defect determination impossibility as a result of the defect determination process (step S0606).

  Subsequently, the inspection unit 209 repeats the processes in steps S0601 to S0606 and S0608 to S0610 until all pages of the printed material are processed (No in step S0607). When all pages are processed (Yes in step S0607), the process ends. To do.

  FIG. 8 is a flowchart illustrating an example of a flow of a page consistency determination process performed by the printed matter inspection apparatus 200 according to the present embodiment.

  First, when the second inspection image is generated by the reading unit 207, the search unit 213 acquires the second inspection image (step S0701), and receives a search request from the inspection unit 209, the second master image is acquired. Obtained from the buffer 205 (step S0702). The order of obtaining the second master image may be any order.

  Subsequently, the search unit 213 performs similarity determination processing for comparing the acquired second inspection image and second master image in units of pixels (step S <b> 0703).

  Subsequently, as a result of the similarity determination process, if the similarity is equal to or greater than the second threshold (Yes in step S0704), the inspection unit 209 updates the acquisition position acquisition position (step S0705).

  For example, when the generation order is the ascending order and the front and back pages, and the first inspection image acquired third from the reading unit 207 is not similar to the first master image with the page number “P3”, the page number Assume that the similarity of the second master image of “P7” is equal to or greater than the second threshold. In this case, the inspection unit 209 updates the current acquisition position in the acquisition order from the page number “P3” to the page number “P7”.

  Subsequently, the inspection unit 209 performs an acquisition order update process (step S0706). The acquisition order update process will be described later.

  On the other hand, if the similarity is less than the second threshold as a result of the similarity determination process (No in step S0704), the inspection unit 209 determines that the second master image is in all orientations (for example, 0 degrees, 90 degrees, and 180 degrees). If it is not compared with the second inspection image at 270 degrees (No in step S0707), the second master image is rotated by 90 degrees (step S0710), the process returns to step S0703, and the similarity determination process is performed again.

  If the second master image is compared with the second inspection image in all directions (Yes in step S0707), the inspection unit 209 determines that there is an unprocessed second master image (Yes in step S0708). The unprocessed second master image is set as an acquisition target (step S0709), and the process returns to step S0702.

  If there is no unprocessed second master image (No in step S0708), the process ends.

  FIG. 9 is a flowchart illustrating an example of a flow of an acquisition order update process performed by the printed matter inspection apparatus 200 according to the present embodiment. In the example illustrated in FIG. 9, the acquisition order is assumed to be the descending order of the page order and the front / back order.

  First, if the first inspection image being processed is the first page (Yes in step S1001) and the current acquisition position in the acquisition order is the last page (Yes in step S1002), the inspection unit 209 determines that the inspection unit 209 The page order is changed to descending order (step S1003).

  If the current acquisition position in the acquisition order is the last -1 page (No in step S1002 and Yes in S1004), the inspection unit 209 changes the page order to descending order and the front / back order to reverse side (step S1005).

  If the current acquisition position in the acquisition order is two pages (No in step S1004, Yes in S1006), the inspection unit 209 changes the front / back order to front / back (step S1007).

  If the current acquisition position in the acquisition order is not even two pages (No in step S1006), the process ends.

  Also, when the first inspection image being processed is not the first page (No in step S1001), the processing ends.

  Note that the inspection unit 209 may change not only the acquisition order but also the page rotation direction.

  As described above, according to the present embodiment, an error in the orientation of setting a printed material, a page change, a page missing, and the like occur, and the correspondence between the first inspection image and the first master image is broken. Since the correspondence between the first inspection image and the first master image is reconstructed, the quality of the printed matter can be correctly inspected.

(Hardware configuration)
FIG. 10 is a block diagram illustrating an example of a hardware configuration of the printing apparatus 100 and the printed matter inspection apparatus 200 according to the present embodiment.

  As shown in FIG. 10, the printing apparatus 100 and the printed matter inspection apparatus 200 have a configuration in which a controller 910 and an engine unit (Engine) 960 are connected by a PCI bus. The controller 910 is a controller that controls the entire control of the printing apparatus 100 or the printed matter inspection apparatus 200, drawing, communication, and input from the operation display unit 920. The engine unit 960 is an engine that can be connected to a PCI bus. In the case of the printing apparatus 100, for example, a printer engine such as a black and white plotter, a one-drum color plotter, or a four-drum color plotter. A scanner engine such as a scanner. The engine unit 960 includes an image processing part such as error diffusion and gamma conversion in addition to the engine part.

  The controller 910 includes a CPU 911, a north bridge (NB) 913, a system memory (MEM-P) 912, a south bridge (SB) 914, a local memory (MEM-C) 917, and an ASIC (Application Specific Integrated Circuit). 916 and a hard disk drive (HDD) 918, and the North Bridge (NB) 913 and the ASIC 916 are connected by an AGP (Accelerated Graphics Port) bus 915. The MEM-P 912 further includes a ROM 912a and a RAM 912b.

  The CPU 911 performs overall control of the printing apparatus 100 or the printed matter inspection apparatus 200, has a chip set including the NB 913, the MEM-P 912, and the SB 914, and is connected to other devices via the chip set.

  The NB 913 is a bridge for connecting the CPU 911 to the MEM-P 912, SB 914, and the AGP bus 915, and includes a memory controller that controls reading and writing to the MEM-P 912, a PCI master, and an AGP target.

  The MEM-P 912 is a system memory used as a memory for storing programs and data, a memory for developing programs and data, a memory for drawing printers, and the like, and includes a ROM 912a and a RAM 912b. The ROM 912a is a read-only memory used as a memory for storing programs and data, and the RAM 912b is a writable and readable memory used as a program / data development memory, a printer drawing memory, and the like.

  The SB 914 is a bridge for connecting the NB 913 to a PCI device and a peripheral device. The SB 914 is connected to the NB 913 via a PCI bus, and a network interface (I / F) unit and the like are also connected to the PCI bus.

  The ASIC 916 is an IC (Integrated Circuit) for image processing having hardware elements for image processing, and has a role of a bridge for connecting the AGP bus 915, the PCI bus, the HDD 918, and the MEM-C 917, respectively. The ASIC 916 includes a PCI target and an AGP master, an arbiter (ARB) that forms the core of the ASIC 916, a memory controller that controls the MEM-C 917, and a plurality of DMACs (Direct Memory) that perform image data rotation by hardware logic and the like. Access Controller) and a PCI unit that performs data transfer between the engine unit 960 via the PCI bus. The ASIC 916 is connected to a USB 940 and an IEEE 1394 (the Institute of Electrical and Electronics Engineers 1394) interface (I / F) 950 via a PCI bus. The operation display unit 920 is directly connected to the ASIC 916.

  The MEM-C 917 is a local memory used as a copy image buffer and a code buffer, and the HDD 918 is a storage for storing image data, programs, font data, and forms.

  The AGP bus 915 is a bus interface for a graphics accelerator card proposed for speeding up graphics processing. The AGP bus 915 speeds up the graphics accelerator card by directly accessing the MEM-P 912 with high throughput. It is.

DESCRIPTION OF SYMBOLS 1 Printed product inspection system 100 Printing apparatus 101 Operation panel 103Y, 103M, 103C, 103K Photosensitive drum 105 Transfer belt 107 Secondary transfer roller 109 Paper feed part 111 Conveyance roller pair 113 Fixing roller 115 Reverse path 117 Tray 121 RIP part 123 Print control Section 125 Printing section 200 Printed matter inspection apparatus 201 Acquisition section 203 Master image generation section 205 Buffer 207, 207A, 207B Reading section 209 Inspection section 211 Storage section 213 Search section 230 Paper feed tray 240 Operation panel 300 Stacker 301 Tray 910 Controller 911 CPU
912 System memory 912a ROM
912b RAM
913 North Bridge 914 South Bridge 915 AGP Bus 916 ASIC
917 Local memory 918 Hard disk drive 920 Operation display unit 940 USB
950 IEEE1394 interface 960 engine part

JP 2013-171570 A

Claims (11)

A master image generation unit that generates a first master image and a second master image having a lower resolution than the first master image based on the original image for each original image of each page constituting the printed matter;
A reading unit that reads the printed matter and generates, for each page, a first inspection image and a second inspection image having a lower resolution than the first inspection image;
A search unit for searching for a second master image similar to the second inspection image from the plurality of second master images for each second inspection image;
For each of the first inspection images, the first inspection image is compared with a first master image of a second master image similar to the second inspection image of the first inspection image, and inspection for inspecting the quality of the printed matter And
A printed matter inspection apparatus comprising: The inspection unit acquires the first inspection image in the order generated by the reading unit, acquires the first master image in an acquisition order based on the generation order of the reading unit, and compares the acquired images.
When the compared first inspection image and the first master image are not similar, the search unit is similar to the second inspection image of the first inspection image from among the plurality of second master images. Search for the second master image to
The printed matter inspection apparatus according to claim 1, wherein the inspection unit acquires a first master image of the searched second master image, and re-compares the first inspection image with the first master image. The generation order is an order determined by the page order and the front / back order set by the inspector,
The printed matter inspection apparatus according to claim 2, wherein the acquisition order is the same order as the generation order.   When the inspection unit re-comparisons the first inspection image, the inspection unit acquires a first inspection image generated next to the first inspection image, and the first master image re-compared in the acquisition order. The printed matter inspection apparatus according to claim 2, wherein the next first master image is acquired and compared.   The inspection unit is configured such that a page number of a first master image similar to the first inspection image generated first by the reading unit is different from a page number of the first master image acquired first in the acquisition order. In this case, the printed matter inspection apparatus according to claim 2, wherein the acquisition order is updated to an order based on the predetermined number.   The printed matter inspection apparatus according to claim 5, wherein when the predetermined number indicates a first page, the inspection unit updates the acquisition order in ascending order of the page order and front-back order.   The printed matter inspection apparatus according to claim 5, wherein when the predetermined number indicates the last page, the inspection unit updates the acquisition order in descending order of page order and front-back order.   The printed matter inspection apparatus according to claim 5, wherein when the predetermined number indicates the next page of the first page, the inspection unit updates the acquisition order in ascending order of page order and front-back order in reverse order.   The printed matter inspection apparatus according to claim 5, wherein when the predetermined number indicates a page before the last page, the inspection unit updates the acquisition order in descending page order and front-back order in reverse order. Based on the original image of each page, a printing unit that generates printed matter;
For each original image of each page constituting the printed matter, a master image generating unit that generates a first master image and a second master image having a lower resolution than the first master image based on the original image;
A reading unit that reads the printed matter and generates, for each page, a first inspection image and a second inspection image having a lower resolution than the first inspection image;
A search unit for searching for a second master image similar to the second inspection image from the plurality of second master images for each second inspection image;
For each of the first inspection images, the first inspection image is compared with a first master image of a second master image similar to the second inspection image of the first inspection image, and inspection for inspecting the quality of the printed matter And
A printed matter inspection system comprising: A master image generation step for generating a first master image and a second master image having a resolution lower than that of the first master image based on the original image for each original image of each page constituting the printed matter;
A reading step of reading the printed matter and generating, for each page, a first inspection image and a second inspection image having a lower resolution than the first inspection image;
A search step of searching for a second master image similar to the second inspection image from the plurality of second master images for each second inspection image;
For each of the first inspection images, the first inspection image is compared with a first master image of a second master image similar to the second inspection image of the first inspection image, and inspection for inspecting the quality of the printed matter Steps,
A printed matter inspection method.

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