JP4438353B2 - Print quality inspection apparatus and method - Google Patents

Description

  The present invention relates to a print quality inspection apparatus that inspects the print quality of a printing apparatus that further prints information on a preprinted sheet on which preprint information has been printed in advance. Specifically, the preprint information is not stored in advance. The present invention also relates to a print quality inspection apparatus and method having an image inspection processing function capable of inspecting print quality.

  Printed materials handled by the printer for core business include printed materials such as contracts, invoices, and transaction statements. Since these printed materials basically print a predetermined image such as a contract content on a printed material (sheet) on which a predetermined image such as a frame or a ruled line has been printed in advance, dirt or white at the time of printing or white It is more important than other prints to prevent defective prints such as missing.

  Against this background, various printed matter inspection apparatuses for preventing defective printed matter from being produced have been proposed.

  The inspection of printed matter in a normal printing apparatus is performed by reading an image of a printed sheet and comparing it with printing source data.

  On the other hand, the above-mentioned contracts, invoices, transaction statements, etc. are printed on sheets on which ruled lines, frame lines, standard documents, etc. are printed in advance, so that different data is printed for each sheet. When the image of the sheet is read, the pre-printed ruled lines, frame lines, fixed form documents, etc. and the newly printed image of the contractor, billing party, etc. are read together, and the printing source data (newly The print quality cannot be inspected by simple comparison with the information to be printed).

As a known technique for solving such inconvenience, in the printed matter inspection apparatus disclosed in Patent Document 1 below, pre-printed ruled lines, frame lines, fixed form documents, etc. are pre-printed on an image obtained by reading a printed sheet. By performing the masking process with the image data (masking format information) of the print pattern, only the image newly printed on the sheet is extracted, and the extracted result is compared with the printing source data (inspection reference image). The quality of printing is inspected.
JP-A-11-78183

  However, in the above-described conventional apparatus, it is indispensable to input preprint information (masking format information) for masking processing in advance, and this requires time and effort.

  In particular, in the case of a printing apparatus that selectively uses a plurality of types of preprinted sheets, it is necessary to input or switch masking format information each time the type of preprinted sheet set in the printing apparatus is changed. There is a problem that the user operation for the print quality inspection becomes extremely complicated.

  The present invention solves the above-mentioned problems and forces the user to perform complicated operations such as storing preprint information in advance according to the preprint sheet and inputting preprint information every time the type of the preprint sheet is changed. It is another object of the present invention to provide a print quality inspection apparatus and method that can perform a print quality inspection of a printed image on a preprint sheet.

  In order to achieve the above object, the invention described in claim 1 is a print quality inspection apparatus for inspecting the print quality of a printing apparatus that further prints image data on a preprinted sheet on which preprint information has been printed in advance. An image reading unit that reads an image of the preprinted sheet after the image data is printed by the apparatus, and an image data of the nth page to be printed after reading the image of the preprinted sheet after the nth page is printed by the image reading unit ( The difference information of the n-1) th page image data is compared with the difference information of the nth page read image data by the image reading means and the (n-1) th page read image data, and based on the comparison result. And image inspection processing means for outputting the print quality judgment result of the nth page or the (n-1) th page with respect to the preprinted sheet.

  According to a second aspect of the present invention, in the first aspect of the present invention, the pre-printed sheet is attached to a printing apparatus including at least one paper feed tray that is a paper feed source, and the pre-printed tray is attached to the advance tray. Sheet set detection means for detecting that a print sheet has been set, determination means for determining whether or not a sheet has been set in the paper feed tray at the start of printing, and sheet setting in the paper feed tray In this case, the print quality determination is not performed after reading the image of the preprinted sheet after printing the first page by the image reading unit, and the print quality determination is performed after reading the image of the preprinted sheet after printing the second page. And a control means for controlling accordingly.

  According to a third aspect of the present invention, in the first aspect of the present invention, the plurality of the plurality of preprinted sheets are attached to a printing apparatus including at least one paper feed tray, and the plurality of the plurality of preprinted sheets are fed based on a print instruction. A paper source recognition unit for recognizing which of the paper feed trays is a paper source, a determination unit for determining whether the paper source is different from the paper source at the end of the previous printing at the start of printing, If the paper supply source is different from the paper supply source at the end of the previous printing, the image reading unit does not perform the print quality determination after the image of the preprinted sheet is printed after the first page is printed. Control means for controlling the print quality to be determined after reading the image of the print sheet, and for each of the plurality of paper feed sources, the print quality of the preprinted sheet fed from the paper feed source is inspected. It is characterized by that.

  According to a fourth aspect of the present invention, in the third aspect of the present invention, a sheet set detecting means for detecting that the preprinted sheet is set on the paper feed tray, and a preprinted sheet to be printed at the start of printing. Determining means for determining whether or not sheet setting has been performed on the sheet feeding tray of the sheet feeding source; and when the sheet setting is performed on the sheet feeding tray of the sheet feeding source, After the first page of the preprinted sheet is read by the image reading means, the print quality determination is not performed, and control is performed so that the print quality is determined after the second page of the preprinted sheet is read. It is characterized by.

  According to a fifth aspect of the present invention, there is provided a plurality of paper feed trays in which preprinted sheets on which preprint information has been printed in advance are set, and image data is further added to the preprinted sheets fed from the respective paper feed trays. In the print quality inspection apparatus for inspecting the print quality of the printing apparatus that prints the sheet, the printing apparatus recognizes which of the plurality of sheet feeding trays is the sheet feeding source at the start of printing, and the printing apparatus An image reading unit that reads an image of a preprinted sheet after printing the image data, and an object to be printed after the image of the preprinted sheet is printed after the nth page is printed by the image reading unit. A plurality of first difference information generating means for generating difference information between the nth page image data and the (n−1) th page image data, and the image reading means Page n A plurality of second difference information generating means for generating difference information between the captured image data and the read image data of the (n-1) th page, the difference information generated by the first difference information generating means, and the second Image inspection processing means for comparing difference information generated by the difference information generating means and outputting a print quality determination result of the nth page or (n-1) th page with respect to the pre-printed sheet based on the comparison result When printing on a preprinted sheet fed from the paper feed source recognized by the recognition means, the difference information is respectively obtained by the first difference information generation means and the second difference information generation means corresponding to the paper feed source. And control means for controlling the image inspection processing means to output the print quality judgment result based on the comparison result of the difference information, and for each of a plurality of paper feed sources, a paper feed from the paper feed source is provided. And performing inspection of the print quality for preprinted sheets to be.

  According to a sixth aspect of the present invention, in the fifth aspect of the present invention, the sheet set detecting means for detecting that the pre-printed sheet is set on the paper feed tray, and the paper source at the start of printing. Determining means for determining whether or not a sheet has been set in the sheet feeding tray, and the control means is configured to determine whether the sheet is set in the sheet feeding tray of the sheet feeding source by the image reading unit. The print quality determination is not performed after reading the image of the preprinted sheet after printing the page, and control is performed to perform the print quality determination after reading the image of the preprinted sheet after printing the second page.

  According to a seventh aspect of the present invention, there is provided a print quality inspection apparatus for inspecting the print quality of a printing apparatus that further prints image data on both sides of a preprinted sheet having preprint information printed on both sides thereof. Recognizing means for recognizing whether the image is for front side printing or for back side printing, and after the front side printing image data is printed on the front side and after the back side printing image data is printed on the back side, pre-printing after the printing Image reading means for reading images on the front and back surfaces of the sheet respectively, and after reading the image of the pre-printed sheet after the n-th surface printing by the image reading means, the n-th surface printing image data and (n-1) sheets The difference information of the image data for eye surface printing, the difference information between the nth surface read image data and the (n−1) th surface read image data by the image reading means are generated and compared. Both after the image reading of the preprinted sheet after the nth backside printing by the image reading means, the difference information between the nth backside printing image data and the (n−1) th backside printing image data, and the image Difference information between the nth backside scanned image data and the (n−1) th backside scanned image data by the reading unit is generated and compared, and based on each comparison result, And image inspection processing means for outputting print quality determination results for the front and back surfaces.

  According to an eighth aspect of the present invention, in the above-mentioned seventh aspect of the present invention, the preprinted sheet is attached to a printing apparatus including at least one paper feed tray that is a paper feed source, and the pre-printed sheet is attached to the advance tray. Sheet set detection means for detecting that a print sheet has been set, determination means for determining whether or not a sheet has been set in the paper feed tray at the start of printing, and sheet setting in the paper feed tray In this case, the image reading unit does not perform the print quality determination after reading the image of the preprinted sheet after the first surface printing by the image reading unit and after reading the image of the preprinted sheet after the first backside printing. Control means for controlling to perform the print quality judgment after reading the image of the preprinted sheet after the second front surface printing and after reading the image of the preprinted sheet after the second back surface printing. Characterized by including the.

  The invention according to claim 9 is a print quality inspection method for inspecting the print quality of a printing apparatus that further prints image data on a preprinted sheet on which preprint information has been printed in advance, after the image data is printed by the printing apparatus. An image reading step for reading an image of the preprinted sheet; after reading the image of the preprinted sheet after printing the nth page in the image reading step; and image data of the nth page to be printed and the (n-1) th page The difference information of the image data is compared with the difference information between the read image data of the nth page and the read image data of the (n−1) th page by the image reading unit, and based on the comparison result, and an image inspection processing step for outputting a print quality determination result of the nth page or the (n−1) th page.

  According to a tenth aspect of the present invention, there is provided a plurality of paper feed trays on which preprinted sheets preprinted with preprint information are set, and image data is further added to the preprinted sheets fed from the respective paper feed trays. In the print quality inspection method for inspecting the print quality of the printing apparatus that prints the sheet, the printing source recognition step for recognizing which of the plurality of sheet feeding trays is the sheet feeding source at the start of printing, and the printing apparatus An image reading step of reading an image of a preprinted sheet after printing the image data, and an object to be printed after reading the image of the preprinted sheet after printing the nth page by the image reading step A first difference information generation step for generating difference information between the image data of the nth page and the image data of the (n−1) th page, and the image reading step. A second difference information generation step for generating difference information between the read image data of the nth page and the read image data of the (n−1) th page, and difference information generated by the first difference information generation step. Image inspection that compares the difference information generated by the second difference information generation step and outputs a print quality determination result of the nth page or the (n−1) th page with respect to the preprinted sheet based on the comparison result A first difference information generation step and a second difference information generation corresponding to the paper source when printing is performed on a preprinted sheet fed from the paper source recognized in the recognition step. By performing the image inspection processing step after generating the difference information in each step, for each of a plurality of paper feed sources, a preprinted sheet fed from the paper feed source is provided. And performing inspection of the print quality.

  The invention according to claim 11 is a print quality inspection method for inspecting the print quality of a printing apparatus that further prints image data on both sides of a preprinted sheet having preprint information printed on both sides thereof. A recognition step for recognizing whether the image is for front side printing or for back side printing, and after the front side printing image data is printed on the front side and after the back side printing image data is printed on the back side, pre-printing after the printing An image reading step for reading the images on the front and back surfaces of the sheet, and after reading the image of the pre-printed sheet after the n-th surface printing in the image reading step, the image data for n-th surface printing and (n-1) sheets The difference information of the image data for eye surface printing, the difference information of the nth surface read image data by the image reading means and the (n−1) th surface read image data are generated. And the difference information between the nth backside image data and the (n-1) th backside image data after reading the image of the preprinted sheet after the nth side backside printing in the image reading step. And the difference information between the nth backside scanned image data and the (n−1) th backside scanned image data generated by the image reading means, and compares the generated difference information based on the comparison results. And an image inspection processing step for outputting print quality determination results for the front and back surfaces of the preprinted sheet.

  According to the present invention, the difference information between the image data to be printed and the image data of the previous page, the read image information input from the image reading means for reading the image of the preprinted sheet after printing, and the previous page of the read image information. Since the difference information of the read image information is compared and the print quality determination result for the pre-printed sheet is output based on the comparison result, the pre-print information pre-printed on the pre-printed sheet is masked as before. As a pre-print sheet, even if the pre-print sheet type is changed, there is no need to re-enter pre-print information, and the print quality can be inspected without any extra work for the user. .

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

  FIG. 1 is a diagram illustrating a conceptual configuration of a print processing system according to the first embodiment.

  The print processing system 100 according to this embodiment includes a printing apparatus and a print quality inspection apparatus attached to the printing apparatus.

  In FIG. 1, the printing apparatus includes a print instruction unit 11, a print information transmission unit 12, a paper feed tray 13, a sheet conveyance path 14, a printing unit 15, a discharge tray 16, and a defective print sheet discharge tray 17.

  In this printing apparatus, a preprint sheet (preprint sheet) on which preprint information (preprint information) has been printed in advance is set on the paper feed tray 13. The preprint sheet is, for example, a contract, an invoice, a transaction statement, or the like, and ruled lines, frame lines, fixed documents, and the like are preprinted in each pattern as preprint information.

  If necessary, different types of preprint sheets on which the above-described preprint information of various patterns are printed can be selectively set on the paper feed tray 13 for printing.

  In this printing apparatus, after a desired type of preprint sheet is set in the paper feed tray 13, printing is started by designating image data to be printed, the number of sheets, and the like from the print instruction unit 11 and giving a print start instruction. Is done.

  When the print start instruction is issued, preprinted sheets (indicated by P in the drawing) are fed out one by one from the paper feed tray 13 and sequentially conveyed to the printing unit 15 through the sheet conveyance path (carry-in path) 14. .

  On the other hand, in response to the print start instruction, the instructed print target image data (original data) is sequentially sent from the print information transmission unit 12 to the printing unit 15 page by page.

  The printing unit 15 sequentially prints the image data of each page received from the print information transmission unit 12 on each preprinted sheet sequentially conveyed from the paper feed tray 13.

  Each preprinted sheet on which the image data is printed by the printing unit 15 is then discharged to the discharge tray 16 through the sheet conveyance path (discharge path) 14.

  FIG. 2 is a conceptual diagram showing a printing operation in the printing apparatus of this embodiment. In the example of FIG. 2, the first, second, third,... Preprinted sheets are sequentially sent from the paper feed tray 13 to the printing unit 15. The image data “X” of the first page, the image data “Y” of the second page, the image data “Z” of the third page,... Are sequentially printed and then discharged.

  The print quality inspection apparatus (see FIG. 1) attached to the printing apparatus that performs the printing operation includes a print quality inspection apparatus main body section 20, an image reading section 27, a sheet set detection section 28, and a discharge tray switching section 29. Composed.

  In this printed matter inspection apparatus, the image data (print target original data) of each page is printed on the inspection apparatus main body unit 20 as the image data is printed on the preprint sheet in order of each page by the printing unit 15. The information is sequentially input from the information transmission unit 12.

  Further, the image reading unit 27 reads an image of each preprinted sheet after the image data of each page is printed by the printing unit 15 and sequentially inputs the read image data to the inspection apparatus main body unit 20.

  The inspection apparatus main body 20 is printed on a preprint sheet by a printing apparatus using the image data for each page input from the print information transmission unit 12 and the read image data of each page input from the image reading unit 27. The image inspection process for determining the print quality of the information (preprint information + image data) is performed.

  In this image inspection process, when it is determined that the print quality on the preprinted sheet is abnormal, the discharge tray switching unit 29 switches the discharge path so that the defective print sheet is replaced with the defective print sheet discharge tray 17. To discharge.

  FIG. 3 is a block diagram showing a functional configuration of the print quality inspection apparatus according to the first embodiment.

  The print quality inspection apparatus according to this embodiment includes components of the inspection apparatus main body 20 in addition to the image reading unit 27, the sheet set detection unit 28, and the discharge tray switching unit 29 shown in FIG.

  As components of the inspection apparatus main body 20, image data to be sequentially input as print targets from the print information transmission unit 12 is fetched in units of pages, and the image data of the previous page is stored until the next page of image data is fetched 1 The pre-page print image storage unit 210 and the read image data from the image reading unit 27 are sequentially fetched, and the read image data of the previous page is stored until the read image data of the next page is fetched. The difference between the storage unit 21 having a storage capacity of at least two pages and the image data newly fetched from the print information transmission unit 12 and the previous page image data stored in the previous page print image storage unit 210 The first difference image generation unit 22 that generates an image, the read image data newly acquired from the image reading unit 27, and the read image data of the previous page stored in the previous page read image storage unit 211. The difference image information generated by the second difference image generation unit 23 and the difference image generation unit 210 that generates the difference image information and the difference image information generated by the difference image generation unit 211, and the comparison result An image inspection processing unit 24 that outputs a print quality determination result for the preprint sheet, a display unit 25 that displays various information such as the print quality determination result, and a control unit 26 that controls the entire apparatus are provided.

  Consider the image inspection processing operation at the timing when the image data of the nth page is printed by the printing apparatus in the print quality inspection apparatus having such a configuration.

  In this case, the image data of the nth page is supplied to the printing unit 15 and printed on the nth preprint sheet, while being input to the difference image generation unit 22 of the inspection apparatus main body unit 20.

  At this time, the image data for the (n−1) th page is stored in the one-page pre-printed image storage unit 210. As a result, the difference image generation unit 22 generates a difference image between the image data on the nth page and the image on the (n−1) th page, and sends the difference image to the image inspection processing unit 24.

  On the other hand, the image data of the nth page is printed on the nth preprint sheet supplied from the paper feed tray 13 in the printing unit 15, and after the printing, the image reading unit 27 prints the image data on the preprint sheet. It is read together with preprint information printed in advance.

  The read image data in the image reading unit 27, that is, the read image data of the preprinted sheet after the completion of the n-th printing is input to the difference image generation unit 23 of the inspection apparatus main body unit 20.

  At this time, the read image data of the (n-1) th page is stored in the previous page read image storage unit 211.

  Thereby, the difference image generation unit 23 generates a difference image between the read image data of the nth page and the read image data of the (n−1) th page, and sends it to the image inspection processing unit 24.

  The image inspection processing unit 24 compares the difference image output output from the difference image generation unit 22 with the difference image output output from the difference image generation unit 23, and based on the comparison result, the nth page or ( n-1) A print quality judgment result indicating whether the print quality on the preprinted sheet of the eye is normal or abnormal is output.

  In this process, the difference image output of the difference image generation unit 22 and the difference image output of the difference image generation unit 23 are compared with the image data of the nth page to be printed and the previous page [(n-1 ) Page image data difference information, difference information between the n page read image data in the image reading unit 27 and the difference information of the read image data of the previous page [(n-1) page]. It is nothing but a comparison.

  Here, paying attention to the image to be read by the image reading unit 27, since the preprint information is the same for the difference between the nth page and the (n-1) th page, the difference image of the preprint information. Disappears and only the difference image between the nth page and the (n−1) th page of the image data further printed with respect to the preprint information should remain.

  Therefore, in the case of normal printing, the difference image output of the difference image generation unit 22 and the difference image output of the difference image generation unit 23, that is, the difference information between the image data of the nth page and the image data of the previous page , The difference information between the read image data of the nth page and the read image data of the previous page is the same.

  In other words, when the difference image output of the difference image generation unit 22 and the difference image output of the difference image generation unit 23 do not match, it can be determined that the print quality is abnormal. As a situation where such a determination result (print quality abnormality determination) is obtained, for example, when the image data of the nth page or the (n-1) th image is printed, dust or the like adheres to the printing unit 15, and these are The situation read by the image reading unit 27 can be considered.

  In order to make the above-described image inspection processing easier to understand, a specific example will be given and described in more detail.

  FIG. 4 is a conceptual diagram showing an image processing operation of each part of the print quality inspection apparatus at the timing of printing image data on the second preprint sheet during the printing operation of the flow shown in FIG.

  At the printing timing, the image data “Y” of the second page is supplied to the printing unit 15 and is input to the difference image generation unit 22 of the inspection apparatus main body unit 20. At this time, the image data “X” of the first page is stored in the one-page previous print image storage unit 210.

  As a result, the difference image generation unit 22 generates a difference image between the image data “Y” of the second page and the image data “X” of the previous page (first page) and sends it to the image inspection processing unit 24. To do.

  On the other hand, the image data “Y” of the second page is printed on the second preprint sheet in the printing unit 15, and after the printing, the preprint information printed on the preprint sheet by the image reading unit 27. (In this example, a rectangular frame) is read.

  The read image (“Y” + rectangular frame) of the preprinted sheet after the second sheet printing in the image reading unit 27 is input to the difference image generation unit 23 of the inspection apparatus main body unit 20.

  At this time, the read image data (“X” + rectangular frame) of the previous page, that is, the first page is stored in the previous page read image storage unit 211.

  As a result, the difference image generation unit 23 makes a difference between the read image data of the second page (“Y” + rectangular frame) and the read image data of the previous page (first page) (“X” + rectangular frame). An image is generated and sent to the image inspection processing unit 24.

  The image inspection processing unit 24 compares the difference image output of the difference image generation unit 22 with the difference image output of the difference image generation unit 23, and if these difference image outputs match, the second page or the first page A determination result that the print quality on the eye preprint sheet is normal is output. If the two differential image outputs do not match, a determination result that the print quality is abnormal is output.

  In the example shown in FIG. 4, at the time of printing the first page and at the time of printing the second page, for example, dust (an image indicated by a graphic in the figure) adheres to the preprint sheet in the printing unit 15, and the difference image generation unit 22 shows that the difference image output of 22 and the difference image output of the difference image generation unit 23 do not match, and a determination result indicating that the print quality of the first page or the second page is abnormal is output. ing.

  The determination result indicating the print quality abnormality in the image inspection processing unit 24 is input to the control unit 26. Based on the determination result, the control unit 26 controls the switching of the discharge tray switching unit 29 so as to be a discharge path as indicated by a dotted line in FIG. 1, for example, and the printed matter for the first and second pages (after printing is completed). The pre-printed sheet is discharged to the defective printing sheet discharge tray 17.

  In addition, the control unit 26 displays on the display unit 25 that the print quality of the first page and the second page is abnormal, notifies the user, and controls to stop the printing operation.

  In the configuration of the print quality inspection apparatus according to this embodiment (see FIG. 3), a plurality of print jobs by a single print job are used unless an operation for resetting a preprint sheet is performed on the paper feed tray 13 of the printing apparatus. When the image data of the first page of the next print job is input after the printing of one sheet is completed, the image data of the last page of the previous print job stored in the one-page previous print image storage unit 210 is set to 1. While taking the difference from the image data of the first page of the new print job as the image data before the page, the read image data by the image reading unit 27 for the preprinted sheet after printing the image data of the first page is used. On the other hand, by taking the difference between the read image data of the last page of the previous print job stored in the previous page read image storage unit 211 as the read image data of the previous page, the above-described image detection is performed. Processing can continue.

  However, after another type of preprint sheet is set on the paper feed tray 13 of the printing apparatus, for example, the image reading unit 27 after printing the first page of image data on the set preprint sheet. Since the preprint information (such as a frame line) in the read image data is different from the preprint information in the read image stored in the one page previous read image storage unit 211 at that time, the one page previous read image is stored. The read image data stored in the unit 211 cannot be handled as read image data one page before the newly input read image data of the first page.

  As a countermeasure against this point, in the present embodiment, at the time of image inspection processing immediately after another type of preprint sheet is set on the paper feed tray 13, the image data of the first page to be newly input and one page before that Difference information with the image data of the first page, generation of a difference between the newly input read image of the first page and the read image of the previous page, and determination of print quality are not performed, and image data and read for the second and subsequent pages From the image data, difference generation from each corresponding data of the previous page and print quality determination are performed.

  In this control, the control unit 26 recognizes from the detection output of the sheet set detection unit 28 that another type of preprint sheet has been set in the paper feed tray 13. That is, it is detected that the paper feed tray 13 has been attached / detached by assuming that another type of preprint sheet has been set.

  When a sheet set (reset) in the paper feed tray 13 is detected based on the detection output of the sheet set detection unit 28, the control unit 26 starts the printing by the first print job thereafter, and the reset pre-set. After the first page of image data is printed on the print sheet and read by the image reading unit 27, the image data of the first page is simply stored in the one-page pre-printed image storage unit 210 and the first page Based on the comparison result between the difference image output of the difference image generation unit 22 and the difference image output of the difference image generation unit 23 in the image inspection processing unit 24. Control is performed so that the print quality judgment is not performed.

  Next, the control unit 26 reads the preprint sheet on which the image data of the second page is printed by the image reading unit 27, and then calculates a difference image between the image data of the second page and the image data of the second page as a difference image generation unit The difference image generation unit 23 generates a difference image between the read image data of the second page and the read image data of the second page, and compares both the difference images. Based on the comparison result, preprinting is performed. The image inspection processing unit 24 is controlled to output the print quality determination result of the first page or the second page for the sheet, and thereafter, the same process is controlled from the third page.

  The processing operation of the print quality inspection apparatus according to the first embodiment described above will be described with reference to the flowchart shown in FIG.

  In the print quality inspection apparatus according to this embodiment, when the control unit 26 recognizes that printing has been started based on the print instruction from the print instruction unit 11 (step S501), the control unit 26 receives the print information from the print information transmission unit 12 based on the print instruction. The image data of the first page to be sent is taken into the difference image generation unit 22 (step S502), and the image of the preprint sheet on which the image data of the first page is printed by the printing unit 15 is read by the image reading unit 27. Then, the read image data of the first page is taken into the difference image generation unit 23 (step S503).

  Next, the control unit 26 refers to the detection output of the sheet set detection unit 28 to check whether or not the sheet has been set on the paper feed tray 13 before the start of printing this time (step S504), and the sheet is set. If not (NO in step S504), the print image inspection process is started.

  In this print image inspection process (step S 505), the difference image generation unit 22 stores the first page image data captured this time and the one-page previous print image storage unit 210 by the method described with reference to FIG. The difference information with the previous image data of the previous page (in this case, the image data of the last page at the time of the previous printing) is generated and sent to the image inspection processing unit 24, while the difference image generation unit 23 takes in this time Difference information between the read image data of the first page and the read image data of the previous page stored in the previous page of read image storage unit 210 (in this case, the read image data of the last page at the previous printing) Is transmitted to the image inspection processing unit 24.

  Then, the image inspection processing unit 24 compares the difference image output of the difference image generation unit 22 with the difference image output of the difference image generation unit 23, and prints the first page on the preprint sheet based on the comparison result. Outputs the judgment result of whether or not the quality is abnormal.

  When the print image inspection process for the first page is completed, the control unit 26 stores the image data for the first page in the one-page previous print image storage unit 210 and the read image data for the first page one page before. Control is performed so as to store in the read image storage unit 211 (step S506).

  Next, the control unit 26 checks whether or not the printing of the print job instructed for printing this time has been completed (step S507). If the printing has not been completed (NO in step S507), the image data of the next page is captured. (Step S502), and reading image data of the same page is fetched (Step S503), and after passing through Step 504, the print image inspection processing in Step S505, and the image data and the read image of the page in Step S506 The process of storing the data in the one-page-before-printed image storage unit 210 and the one-page-before-read image storage unit 211 is continued until the end of printing (YES in step S507).

  On the other hand, if it is determined in step S504 that the sheet has been set in the paper feed tray 13 after the start of printing (YES in step S504), the control unit 26 determines that the pre-printed sheet that has been reset. After the first page of image data is printed and read by the image reading unit 27, the first page of image data is stored in the one-page pre-printed image storage unit 210 and the first page of read image data Is stored in the one-page previous read image storage unit 211, and the image inspection processing unit 24 determines the print quality based on the comparison result between the difference image output of the difference image generation unit 22 and the difference image output of the difference image generation unit 23. Is controlled not to be performed (step S511).

  Thereafter, the control unit 26 resets the held sheet set state based on the detection output of the sheet set detection unit 28 (step S512), and proceeds to the processing after step S507.

  As described above, in the first embodiment, after the image reading unit 27 reads the image of the preprinted sheet after printing the nth page, the image data of the nth page to be printed and the image data of the (n-1) th page. And the difference information between the read image data of the nth page by the image reading unit 27 and the read image data of the (n-1) th page, and based on the comparison result, (N-1) It is determined whether or not the printing result of the page is normal.

  According to such a configuration, the print quality inspection can be performed without storing the preprint information preprinted on the preprint sheet as masking format information in the conventional manner. Therefore, even if the type of the preprint sheet is changed, an operation such as re-inputting the masking format information becomes unnecessary, and the user's trouble can be reduced.

  FIG. 6 is a diagram showing a conceptual configuration of a print processing system according to the second embodiment.

  In FIG. 6, parts having the same functions as those of the parts of the system according to the first embodiment (see FIG. 1) are denoted by the same reference numerals.

  In the print processing system 100A of this embodiment, the printing apparatus includes a plurality of paper feed trays 13a, 13b, and 13c.

  In these paper feed trays 13a, 13b, and 13c, for example, preprint sheets (contracts, invoices, transaction statements, etc.) on which different preprint information is printed (different types) are set.

  On the other hand, the printed matter inspection apparatus attached to the printing apparatus has a plurality of sheet set detection units 28a, 28b for detecting the sheet sets of the paper feed trays 13a, 13b, 13c, respectively, in the printed matter inspection apparatus in the first embodiment. , 28c are provided.

  In the printing apparatus in the system of this embodiment, a printing operation is started by giving a printing start instruction designating image data to be printed, the number of sheets, a printing paper type, and the like from the printing instruction unit 11.

  When the print start instruction is given, a paper feed tray, for example, 13a in which a preprint sheet corresponding to the paper type is set from the designated paper type is recognized as a paper source, and the paper of the paper source is supplied. While the preprint sheets (indicated by P in the figure) are fed out and conveyed one by one from the tray 13a, the instructed image data to be printed is sequentially sent from the print information transmitting unit 12 to the printing unit 15 page by page. In the same manner as described in the first embodiment, the image data of each page is sequentially printed on the preprint sheet of each page and discharged to the discharge tray 16.

  After the printing is finished, in the next print job, when a print start instruction is given, by specifying another paper type and print target data, a preprint sheet corresponding to the paper type is set. The preprint sheets can be fed in order from 13b, and the same printing operation can be performed.

  FIG. 7 is a conceptual diagram showing a printing operation in the printing apparatus of this embodiment. In the example of FIG. 7, according to the first print job, the first, second, third,... Preprint sheets (preprint information = one rectangular ruled line frame) are sequentially supplied from the paper feed tray 1 (13a). The image data is sent to the printing unit 15, and in the printing unit 15, the first page image data “X”, the second page image data “Y”, and the third page image data “Z” “,... Are printed sequentially, and then, in the next print job, the first, second, third,... Preprint sheets (preprint information = two rectangular ruled lines) from the paper feed tray 2 (13b). Frame) are sequentially sent to the printing unit 15, and the printing unit 15 applies the image data “xx” for the first page, the image data “yy” for the second page, and the third page to the preprint sheet of each page. The image data “zz”,... Are sequentially printed and discharged.

  For reference, FIG. 8 shows an external configuration of a print processing system 100A according to this embodiment.

  In FIG. 8, a solid line (curved line) with an arrow indicates that, for example, image data is printed from the start of conveyance of the preprinted sheet set on the paper feed tray 13b, and the discharge tray 16 (in this example, 16a, 16a, 16b is provided), and the route to the discharge is shown. The preprint sheets set in the other paper feed trays 13a, 13c, and 13d are also fed out one by one from the paper feed trays 13a, 13c, and 13d through a feed path (not shown), and then the same path is used. Image data can be printed while being conveyed.

  The configuration of the print quality inspection apparatus according to this embodiment can be realized by, for example, a configuration equivalent to that according to the first embodiment shown in FIG. However, in the print quality inspection apparatus according to this embodiment, as the sheet set detection unit, sheet set detection units 28a, 28b, and 28c corresponding to the sheet feeding cassettes 13a, 13b, and 13c are provided.

  Hereinafter, the image inspection process in the print quality inspection apparatus of the second embodiment will be described with reference to the flowchart shown in FIG. 9 with reference to FIG.

  In the print quality inspection apparatus of this embodiment, the control unit 26 confirms that printing has been started by a print instruction from the print instruction unit 11 (designation of image data to be printed, number of prints, print paper type, etc.). When it is recognized (step S901), first, the paper source (paper feed tray in which a preprint sheet corresponding to the paper type is set) is recognized from the paper type specified by the print instruction (step S902). Hold.

  Subsequently, the control unit 26 takes in the image data of the first page sent from the print information transmission unit 12 to the difference image generation unit 22 based on the print instruction (image data to be printed, number of prints) (step S903). Then, the image reading unit 27 reads the image of the preprint sheet on which the image data of the first page is printed by the printing unit 15, and the read image data of the first page is taken into the difference image generation unit 23 (step S904).

  Next, the control unit 26 refers to the information on the paper feed source held at the previous printing to determine whether the paper feed source related to the current printing is the same as the paper feed source at the end of the previous printing. A check is made (step S905).

  If the current paper supply source is the same as the previous paper supply source (YES in step S905), the control unit 26 then refers to the detection outputs of the sheet set detection units 28a, 28b, and 28c to determine the current paper supply source. It is checked whether or not a sheet is set at the paper source (any one of the paper feed trays 13a, 13b, and 13c) before the start of printing (step S906). If no sheet is set (step S906 NO), the print image is displayed. Start the inspection process.

  In the print image inspection process (step S907), the difference image generation unit 22 stores the first page image data captured this time and the one-page previous print image storage unit 210 by the method described with reference to FIG. On the other hand, a difference image with the previous image data of the previous page (in this case, the image data of the last page at the time of previous printing) is generated and sent to the image inspection processing unit 24, while the difference image generation unit 23 captures this time. The difference image between the read image data of the first page and the read image data of the previous page stored in the read image storage unit 210 of the previous page (in this case, the read image data of the last page at the previous printing). Is transmitted to the image inspection processing unit 24.

  Then, the image inspection processing unit 24 compares the difference image output of the difference image generation unit 22 with the difference image output of the difference image generation unit 23, and prints the first page on the preprint sheet based on the comparison result. Outputs the judgment result of whether or not the quality is abnormal.

  When the print image inspection process for the first page is completed, the control unit 26 stores the image data for the first page in the one-page previous print image storage unit 210 and the read image data for the first page one page before. Control is performed so as to store in the read image storage unit 211 (step S908).

  Next, the control unit 26 checks whether or not printing of the print job instructed for printing this time has been completed (step S909). If the printing has not been completed (NO in step S909), the image data for the next page is captured. (Step S903) and the reading image data of the same page are fetched (Step S904), and after passing through Steps S905 and S906, the print image inspection processing in Step S907 and the image data of the page in Step S908 The process of storing the read image data in the one-page-before-printed image storage unit 210 and the one-page-before-read image storage unit 211 is continued until the end of printing (YES in step S909).

  On the other hand, if the current paper source is different from the previous paper source in step S905 after printing is started (NO in step S905), the control unit 26 prints the image data of the first page and the image reading unit 27 After reading, the image data of the first page is stored in the one-page pre-printed image storage unit 210, and the read image data of the first page is stored in the one-page pre-read image storage unit 211 (step S911).

  In accordance with this, the control unit 26 performs the print quality determination on the image inspection processing unit 24 based on the comparison result between the difference image output of the difference image generation unit 22 and the difference image output of the difference image generation unit 23. Then, the process proceeds to step S909 and subsequent steps.

  As a result, when there are remaining print pages and the printing has not been completed (NO in step S909), the process from step S903 onward is continued, so that a preprint sheet from a paper source different from the previous time is processed. Also in the printing operation, for the image data and the read image data on and after the second page, the normal image inspection process can be continued through the processes in steps S907 and S908.

  Also, after starting printing, the paper source is not changed from the previous time (NO in step S905), but if it is determined in step S906 that a sheet is set at the current paper source (YES in step S906), control is performed. The unit 26 prints the image data of the first page on the reset preprint sheet and reads the image data by the image reading unit 27, and then stores the image data of the first page as the one-page pre-printed image storage unit 210. And the read image data of the first page is stored in the previous read image storage unit 211, and the image inspection processing unit 24 outputs the difference image output from the difference image generation unit 22 and the difference image generation unit 23. Control is performed so that the print quality determination based on the comparison result with the difference image output is not performed (step S921).

  Thereafter, the control unit 26 resets the held sheet set state based on the detection output of the sheet set detection unit 28 (step S922), and proceeds to the processing after step S909.

  As a result, when there are remaining print pages and printing has not been completed (NO in step S909), the processing after step S903 is continued, so that the same paper source as the previous time and the paper source Even when printing on the preprinted sheet reset in the above, the image data and the read image data for the second and subsequent pages can continue normal image inspection processing through the processing of step S907 and step S908.

  As described above, the print quality inspection apparatus according to the second embodiment is attached to a printing apparatus including a plurality of paper feed trays 13a, 13b, and 13c, and based on a print instruction from the print instruction unit 11, the paper feed tray 13a, It recognizes which of 13b and 13c is the paper feed source, determines whether the paper feed source is different from the paper feed source at the end of the previous printing, and the paper feed source at the end of the previous printing. When the image reading unit 27 reads the image of the preprinted sheet after printing the first page by the image reading unit 27, the printing result determination is not performed, and the printing result is determined after reading the image of the preprinted sheet after printing the second page. I try to control it.

  According to such a configuration, even in a situation where the feeding of preprinted sheets (different types) from a plurality of paper feeding sources (paper feeding trays 13a, 13b, 13c) is selectively switched, these paper feeding sources. Can be grouped, and the print quality can be inspected for each pre-printed sheet fed from each paper source.

  In addition, in this embodiment, sheet set detectors 28a, 28b, and 28c for detecting that a preprint sheet has been set are provided for each of the plurality of paper feed trays 13a, 13b, and 13c. From the detection outputs of the set detection units 28a, 28b, and 28c, it is determined whether or not a sheet is set on the paper source tray. If the sheet is set on the paper source tray, After the image of the first page is read by the image reading unit 27, the print result determination is not performed by the image inspection processing unit 24, and the print result determination is performed after the image of the second page is read.

  As a result, the paper feed source is the same as that at the time of the previous printing, but even when the sheet is set before the current printing, it is possible to determine the print quality as usual for the print image data for the second and subsequent pages.

  Note that the print quality inspection apparatus according to the second embodiment is configured to include only one set of the one-page pre-printed image storage unit 210 and the one-page pre-read image storage unit 211 as in the first embodiment. It is good also as a structure provided with two or more sets corresponding to a paper feed tray.

  FIG. 10 is a block diagram showing the functional configuration of the print quality inspection apparatus according to the third embodiment.

  As in the second embodiment, the print quality inspection apparatus according to this embodiment is attached to a printing apparatus that further prints image data on a preprint sheet selectively fed from a plurality of paper feed trays. The printing quality of the printing apparatus is inspected, and corresponds to a plurality of paper feed trays 1, 2,..., One-page pre-printed image storage unit 210a, one-page pre-read image storage unit 211a, and one page, respectively. A plurality of sets of a pre-print image storage unit 210b and a one-page pre-read image storage unit 211b are provided.

  In accordance with this, the difference image generation units 22a and 23a, the one-page pre-print image storage unit 210b, and the one-page pre-read image corresponding to the one-page pre-print image storage unit 210a and the one-page pre-read image storage unit 211a, respectively. .. Corresponding to the storage unit 211b, and these are connected to the image inspection processing unit 24.

  Other components in the print quality inspection apparatus are given the same reference numerals to perform the same functions as those in the other embodiments.

  In the print quality inspection apparatus of this embodiment, as in the second embodiment, the control unit 26 is based on a print instruction from the print instruction unit 11, and any of the paper feed trays 1, 2,. Recognize.

  Thereafter, in the image inspection process, the image data input from the print information transmission unit 12 is distributed to the one-page previous print image storage unit (any one of 210a, 210b,...) Corresponding to the recognized paper source, The read image data read by the image reading unit 27 is also distributed to the one-page previous read image storage unit (any one of 211a, 211b,...) Corresponding to the paper supply source.

  Thereby, for example, in the printing operation of the nth page when the paper supply source is the paper feed tray 1, after the image reading unit 27 reads the image of the nth page, the difference image generation unit 22a performs the print information transmission unit. Difference information between the image data of the nth page input from the image data 12 and the image data of the (n−1) th page stored in the one-page previous print image storage unit 210a is generated, while the difference image generation unit 23a. Then, difference information between the read image data of the nth page input from the image reading unit 27 and the read image data of the (n−1) th page stored in the previous page read image storage unit 211a is generated. .

  Then, the image inspection processing unit 24 compares the difference image output of the difference image generation unit 22a with the difference image output of the difference image generation unit 23a, and based on the comparison result, a preprint fed from the sheet supply source. The print quality judgment result of the nth page or the (n-1) th page in printing on the sheet is output.

  Similarly, when the paper feed source is other than the paper feed tray 1, similarly, the one-page previous print image storage unit corresponding to the paper feed source (210b when the paper feed source is the paper feed tray 2) and the difference corresponding thereto After the image generation unit (22b), the one-page previous read image storage unit (211b) and the corresponding difference image generation unit (23b), the image inspection processing unit 24 supplies the paper from the paper source. A print quality determination process in printing on the preprinted sheet is performed.

  Thus, in the third embodiment, after the image of the n-th printed sheet is read by the image reading unit 27, the difference between the n-th page image data to be printed and the (n-1) -th page image data. A plurality of first difference information generation units (22a, 22b,...) That generate information and difference information between the read image data of the nth page and the read image data of the (n−1) th page by the image reading unit 27. A plurality of second difference information generation units (23a, 23b,...) To be generated are respectively provided corresponding to the paper feed trays, and moreover, common to these first and second difference information generation units. The image inspection processing unit 24 is arranged.

  According to this configuration, for example, the control unit 26 recognizes a paper feed source (paper feed tray) based on a print instruction from the print command unit 11 and performs a printing operation on a preprint sheet fed from the paper feed source. Difference information is generated by the first difference information generation unit and the second difference information generation unit corresponding to the paper supply source, and the image inspection processing unit 24 outputs a print quality determination result based on the comparison result of the difference information. As in the second embodiment, it is possible to divide the paper feed sources into groups, and to inspect the print quality of the preprinted sheets fed from each paper feed source. Become.

  In this embodiment as well, it is determined whether or not a sheet has been set on the sheet feed tray of the sheet feed source based on the detection output of the sheet set detection units 28a, 28b, and 28c, and the sheet feed of the sheet feed source is determined. When the sheet is set on the tray, after the first page image is read by the image reading unit 27, the print result determination is not performed by the image inspection processing unit 24, and the above print result is obtained after the second page image is read. You may control to perform determination.

  FIG. 11 is a diagram illustrating a conceptual configuration of a print processing system according to the fourth embodiment.

  In FIG. 11, the same reference numerals are given to the portions that perform the same functions as the respective portions of the system according to each of the above embodiments.

  In the print processing system 100B of this embodiment, the printing apparatus includes a print instruction unit 11, a print information transmission unit 12, a paper feed tray 13, a sheet conveyance path 14, a printing unit 15, a discharge tray 16, a defective print sheet discharge tray 17, The sheet reversing unit 18 is configured.

  In this printing apparatus, a preprint sheet (double-sided preprint sheet) in which different preprint information is preprinted on the front and back is set on the paper feed tray 13.

  In this printing apparatus, double-sided printing is started by giving a print start instruction designating double-sided printing, image data to be printed, the number of sheets, and the like from the print instruction unit 11.

  When the print start instruction is given, the designated image data to be printed is sequentially sent from the print information transmission unit 12 to the printing unit 15 one page at a time, while the preprint sheet (P Are fed out one by one and sequentially conveyed to the printing unit 15 through the sheet conveyance path (carry-in path) 14.

  In the printing unit 15, first, the surface printing image data for the first sheet is printed on the surface of the first preprint sheet.

  The preprinted sheet after the front surface printing is reversed (reversed) by the sheet reversing unit 18 and is carried into the printing unit 15 again, and the printing unit 15 prints the back surface for the first sheet on the back surface of the preprinted sheet. The image data is printed.

  The preprinted sheet printed on both sides is then discharged to a discharge tray 16 through a sheet conveyance path (discharge path) 14.

  Similarly, the front side image data and the back side image data are printed on both sides of the second and subsequent preprinted sheets, and are discharged to the discharge tray 16.

  FIG. 12 is a conceptual diagram showing a printing operation in the printing apparatus of this embodiment. In the example of FIG. 12, the first, second,... Preprinted sheets (preprint information: front surface = one rectangular ruled line frame, back surface = two rectangular ruled line frames) from the paper feed tray 13 in order. In the printing unit 15, the front-side printing image data “X” for the first sheet is provided on the front surface of the first pre-printed sheet, and the back-side printing image for the first sheet is provided on the back surface thereof. The data “xx” is printed and discharged, and then the surface print image data “Y” for the second sheet is printed on the front surface of the second preprint sheet, and the back surface for the second sheet is printed on the back surface thereof. It is shown that the printing image data “yy” is printed and discharged, and the preprint sheets from the third sheet are similarly printed on both sides and discharged.

  As described above, the print quality inspection apparatus (see FIG. 11) of the present embodiment attached to the printing apparatus that further prints information on both sides of the preprint sheet on which the different preprint information is pre-printed on the front and back sides is used. The apparatus main body 20B, the image reading unit 27, the sheet set detection unit 28, and the discharge tray switching unit 29 are provided.

  In the inspection apparatus main body 20B, as the image data for front side printing and back side printing for each number of sheets are printed on both sides of the preprinted sheet by the printing unit 15, the image data for front side printing for the number of sheets, Image data for back side printing is sequentially input from the print information transmission unit 12.

  In addition, the image reading unit 27 is configured so that the printing unit 15 prints the front-side printing image data on the front surface and the back-side printing image data on the back surface of each preprinted sheet. Then, the front and back images of the preprinted sheet after printing are read, and the front side read image data and the back side read image data obtained by the reading are sequentially input to the inspection apparatus main body 20B.

  The inspection apparatus main body 20B receives each number of front side printing image data and back side printing image data input from the print information transmission unit 12, and each number of front side reading image data and back side reading input from the image reading unit 27. Using the image data, an image inspection process is performed in which the print quality of information (preprint information + image data) printed on both sides of the preprint sheet by the printing apparatus is distinguished for each of the front and back surfaces.

  In the image inspection process, when the determination result that the print quality on the front surface or the back surface of the preprint sheet is abnormal is obtained, the discharge tray switching unit 29 switches the discharge path, thereby printing the defective print sheet. The sheet is discharged to the sheet discharge tray 17.

  Further, the sheet set detection unit 28 detects that a sheet has been set on the paper feed tray 13 and inputs the detection result to the inspection apparatus main body 20B.

  FIG. 13 is a block diagram illustrating a functional configuration of a print quality inspection apparatus according to the fourth embodiment.

  The print quality inspection apparatus according to this embodiment includes components of the inspection apparatus main body 20B in addition to the image reading unit 27, the sheet set detection unit 28, and the discharge tray switching unit 29 shown in FIG.

  As the constituent elements of the inspection apparatus main body 20B, first, the image data for surface printing of each number input as a print target from the print information transmission unit 12 is sequentially fetched, and until after the image data for surface printing of the next number is fetched. The read image data at the time of front side reading is sequentially fetched from the front side print image storage unit 212a for storing the front side print image data and the image reading unit 27, and after the front side read image data of the next page is taken in. The first-side front-read image storage unit 213a for storing the front-side front-side read image data and the back-side print image data input as the print target from the print information transmission unit 12 are sequentially fetched, and the next back-side print image The pre-sheet printing image storage unit 212b that stores the image data for the back printing of the previous sheet until the data is captured, and the scanned image data at the time of the back scanning are sequentially captured from the image scanning unit 27. Inclusive, a storage unit 21 including the next sheet of the back side scanned until after capture of the image data before one its back side scanned before one for storing image data read image storage section 213b.

  In addition, the inspection apparatus main body 20B includes the front surface printing image data newly acquired from the print information transmission unit 12 and the previous front surface printing image data stored in the previous printing image storage unit 212a. The difference image generation unit 22a that generates the difference image, the surface read image data newly acquired from the image reading unit 27, and the difference image between the previous surface read image data stored in the previous image read image storage unit 213a. Difference image generation unit 22b to generate, difference image between back side print image data newly fetched from print information transmission unit 12 and previous back side print image data stored in front side print image storage unit 212b The difference image generation unit 22b for generating the back side read image data newly acquired from the image reading unit 27, and the back side read image of the previous page stored in the previous page read image storage unit 213b A difference image generation unit 23b that generates a difference image of data, the difference image generated by the difference image generation unit 22a is compared with the difference image generated by the difference image generation unit 23a, and based on the comparison result, a preprint sheet The print quality inspection result for the surface of the image is output and the difference image generated by the difference image generation unit 22b is compared with the difference image generated by the difference image generation unit 23b. Based on the comparison result, the preprint sheet And an image inspection processing unit 24 that outputs a print quality inspection result on the back surface of the image.

  In addition, the inspection apparatus main body 20B includes a display unit 25 and a control unit 26. The control unit 25 performs display control such as displaying the fact on the display unit 25 according to the print quality abnormality determination in the image inspection processing unit 24, switching control of the discharge tray switching unit 29 based on the print quality abnormality determination, and printing. Control of the entire apparatus, including data distribution control that determines whether the image data to be input is for front side printing or back side printing, and distributes the front side printing image data and back side printing image data to the respective processing units I do.

  The image inspection process in the print quality inspection apparatus according to the fourth embodiment will be described below with reference to the flowchart shown in FIG.

  In the print quality inspection apparatus of this embodiment, the control unit 26 recognizes that printing has started according to a print instruction from the print instruction unit 11 (designation of double-sided printing, image data to be printed, number of prints, etc.). Then (step S1401), it is recognized whether the image data for printing sent from the print information transmitting unit 12 is for front side printing or back side printing (step S1402).

  When it is recognized that the image data is for front side printing (step S1402 for front side), the front side printing image data (for first page) is used as a front side print image difference processing unit. 22a (step S1403), the image reading unit 27 reads an image of the surface of the preprint sheet on which the first surface printing image data is printed by the printing unit 15, and the first surface reading image is read. The data is taken into the difference image generation unit 23a which is a table read image difference processing unit (step S1404).

  Next, the control unit 26 refers to the detection output of the sheet set detection unit 28 to check whether or not the sheet has been set on the paper feed tray 13 before starting the printing (step S1405), and the sheet has been set. If not (NO in step S1405), the print image inspection process is started.

  In the print image inspection process (step S1406), the difference image generation unit 22a stores the first-side front-side print image data captured this time and the one-sheet-before print stored in the one-sheet-previous print image storage unit 212a. Difference information with the image data for front surface printing (in this case, image data for front surface printing of the last page at the time of previous printing) is generated and sent to the image inspection processing unit 24, while the difference image generation unit 23a captures this time. The first surface read image data for the first sheet and the front surface read image data for the previous sheet stored in the previous sheet read image storage unit 213a (in this case, the surface read image data of the last page at the time of the previous printing) Is generated and sent to the image inspection processing unit 24.

  At this time, the image inspection processing unit 24 has been instructed by the control unit 26 that the image data for front side printing is being processed, and based on the instruction, the difference image output of the difference image generation unit 22a and the difference image generation The difference image output of the unit 23a is compared, and based on the comparison result, a determination result as to whether or not the surface print quality on the first preprint sheet is abnormal is output.

  When the first front surface print image inspection process is completed, the control unit 26 stores the first front surface print image data in the first front print image storage unit 212a and the first front surface read image. Control is performed so that the data is stored in the immediately preceding read image storage unit 213a (step S1407).

  Next, the control unit 26 checks whether or not the printing instructed this time is finished (step S1408). If the printing is not finished (NO in step S1408), the image data to be input next is fetched and the image is inputted. It recognizes whether the data is image data for front side printing or image data for back side printing.

  If it is recognized that the image data is for back side printing (back side in step S1402), the back side print image difference processing unit is used as the back side print image difference processing unit. 22b (step S1411), and the image reading unit 27 reads the image on the back side of the preprint sheet on which the first back side printing image data is printed by the printing unit 15, and the back side read image of the first sheet The data is taken into the difference image generation unit 23b which is a back side read image difference processing unit (step S1412).

  Next, the control unit 26 refers to the detection output of the sheet set detection unit 28 to check whether or not the sheet has been set on the paper feed tray 13 before starting the printing (step S1405), and the sheet has been set. If not (NO in step S1405), the print image inspection process is started.

  In this print image inspection process (step S1406), the difference image generation unit 22b stores the first back print image data captured this time and the previous one stored in the previous print image storage unit 212b. Difference information with the image data for back side printing (in this case, the image data for back side printing of the last page at the time of the previous printing) is generated and sent to the image inspection processing unit 24, while the difference image generating unit 23b takes in this time. The first back side scanned image data and the previous back side scanned image data stored in the previous scanned image storage unit 213b (in this case, the back side scanned image data of the last page at the time of previous printing) Difference information is generated and sent to the image inspection processing unit 24.

  At this time, the image inspection processing unit 24 has been instructed by the control unit 26 that the back side printing image data is being processed, and based on the instruction, the difference image output of the difference image generation unit 22b and the difference image generation The difference image output of the unit 23b is compared, and based on the comparison result, a determination result as to whether or not the print quality of the back surface on the first preprint sheet is abnormal is output.

  Thereafter, it is checked whether or not the current printing has been completed (step S1408). Until the printing is completed (YES in step S1408), the processes in steps S1402 to S1407, S1411, and S1412 are repeatedly performed, thereby performing the duplex printing. Execute the print quality judgment process for the front and back sides.

  When the duplex printing operation is started, if it is determined in step S1405 that a sheet is set in the sheet feeding tray 13 that is a sheet feeding source (YES in step S1405), the control unit 26 determines that the preset sheet is reset. After the first front surface printing image data is printed on the print sheet and read by the image reading unit 27, the first front surface printing image data is stored in the previous front printed image storage unit 212a. First surface read image data is stored in the previous read image storage unit 213a, and in the image inspection processing unit 24, the difference image output of the difference image generation unit 22a and the difference image output of the difference image generation unit 23a Control is performed so that the print quality determination based on the comparison result is not performed (step S1421).

  Next, the control unit 26 checks whether or not the first (first sheet) double-sided printing has been completed (step S1422). If double-sided printing has not been completed (step S1422 NO), the control unit 26 passes through steps S1408 and S1402. Proceed to the second side printing.

  During the first back side printing operation, if it is determined in step S1405 that a sheet is set on the paper feed tray 13 (YES in step S1405), the control unit 26 has already printed the front side printing image data on the front side. The first back side printing image data is printed on the pre-printed sheet and read by the image reading unit 27, and then the first back side printing image data is stored in the pre-sheet printing image storage unit 212b. And the first back side read image data is stored in the previous one read image storage unit 213b. In the image inspection processing unit 24, the difference image output of the difference image generation unit 22b and the difference image generation unit 23b are stored. Control is performed so that the print quality determination based on the comparison result with the difference image output is not performed (step S1421).

  Thereafter, the control unit 26 recognizes that the first double-sided printing has been completed (YES in step S1422), resets the held sheet set state based on the detection output of the sheet set detection unit 28 (step S1423), and then proceeds to step Through S1408 and S1402, the second and subsequent duplex printing is executed.

  By the processing in step 1421 described above, when double-sided printing is started after the preprint sheet is reset on the paper feed tray 13, normal double-sided printing image inspection processing may be continued for the second and subsequent double-sided printing. it can.

  Note that, according to the series of double-sided printing operations shown in FIG. 14, in the processing of step S1406 at the time of double-sided printing on the nth preprinted sheet, the nth surface preprinted preprinted sheet by the image reading unit 27 Difference between the n-th surface printing image data input from the print information transmitting unit 12 and the (n−1) -th sheet front printing image data stored in the previous printing image storage unit 212a. The nth surface read image data generated by the difference image generation unit 22a and input from the image reading unit 27 and the (n-1) th surface stored in the previous read image storage unit 213a. Difference information of the read image data is generated by the difference image generation unit 23 a and is input to the image inspection processing unit 24.

  Then, in the image inspection processing unit 24, based on the difference image output of the difference image generation unit 22a and the difference image output of the difference image generation unit 23a, the print quality on the surface of the nth preprint sheet is normal. Is output.

  Similarly, in the process of step S1406, after the image reading unit 27 reads the image of the nth backside pre-printed preprinted sheet, the nth backside printing image data input from the print information transmitting unit 12 and the previous one are printed. A difference image generation unit 22b generates a difference image of the (n-1) th sheet back surface printing image data stored in the print image storage unit 212b and inputs from the image reading unit 27. Difference information between the data and the (n−1) th back-side read image data stored in the previous-read image storage unit 213b is generated by the difference image generation unit 23b and input to the image inspection processing unit 24, respectively. The

  Then, the image inspection processing unit 24 determines whether the print quality for the back surface of the nth preprint sheet is normal based on the difference image output of the difference image generation unit 22b and the difference image output of the difference image generation unit 23b. Is output.

  As described above, according to the fourth embodiment, after the image reading unit 27 reads the image of the nth surface-printed preprinted sheet, the image data for nth surface printing and the (n−1) th sheet surface are read. The difference information of the image data for printing, the difference information between the nth surface read image data by the image reading unit 27 and the (n−1) th surface read image data are generated and compared, and the image reading unit 27. After reading the image of the pre-printed sheet after the back side printing of the nth sheet by 27, the difference information between the image data for nth sheet backside printing and the image data for (n-1) th sheet backside printing, and n sheets by the image reading unit 27 The difference between the back side scanned image data of the eye and the (n-1) th back side scanned image data is generated and compared, and the print quality for the front and back sides of the preprinted sheet is determined based on the comparison results. Judgment was made Than is.

  According to this configuration, it is attached to a printing apparatus that further prints image data on both sides of a preprint sheet having preprint information printed on the front and back sides, and another inspection object is determined whether the inspection object by the printing apparatus is the front surface or the back surface. In addition, the print quality can be inspected for each group, and the user's trouble such as storing masking format information in advance as in the prior art can be eliminated.

  The present invention is not limited to the embodiments described above and shown in the drawings, and can be implemented by being appropriately modified within the scope not changing the gist thereof.

  For example, in each of the above-described embodiments, the one-page previous print image storage unit, the one-page previous read image storage unit, and the difference image generation unit have different print data (original data) and read image data, respectively. Although it is set as the structure of a set, it is good also as a common 1 set of structure.

  Further, in the fourth embodiment, the case where there is one paper feed tray for setting the double-side preprinted print sheet has been described. However, a plurality of paper feed trays are provided, and each paper feed tray is fed from there. You may comprise so that the printing quality determination of the surface of a double-sided preprinted sheet and the back surface may be performed.

  The present invention can be applied to a printing apparatus such as a basic business printer that further prints information on a preprinted sheet on which preprinted information has been printed in advance, and includes difference information between image data to be printed and image data of the previous page. Based on the comparison result between the read image information inputted from the image reading means for reading the image of the preprinted sheet after printing and the difference information of the read image information of the previous page, the print quality judgment result for the preprinted sheet is output. By doing so, it is possible to inspect the print quality without storing the preprint information in advance.

1 is a diagram illustrating a conceptual configuration of a print processing system according to a first embodiment. FIG. 3 is a conceptual diagram illustrating a printing operation in the printing apparatus according to the first embodiment. FIG. 2 is a block diagram showing a functional configuration of a print quality inspection apparatus according to the first embodiment. FIG. 3 is a conceptual diagram showing specific image processing operations of each part of the print quality inspection apparatus according to the first embodiment. 6 is a flowchart showing processing operations of the print quality inspection apparatus according to the first embodiment. The figure which shows the conceptual structure of the printing processing system concerning a 2nd Example. FIG. 9 is a conceptual diagram illustrating a printing operation in a printing apparatus according to a second embodiment. The figure which shows the external appearance structure of the printing processing system of a 2nd Example. 9 is a flowchart showing a processing operation of the print quality inspection apparatus according to the second embodiment. FIG. 9 is a block diagram showing a functional configuration of a print quality inspection apparatus according to a third embodiment. The figure which shows the conceptual structure of the print processing system concerning a 4th Example. FIG. 10 is a conceptual diagram illustrating a printing operation in a printing apparatus according to a fourth embodiment. The block diagram which shows the function structure of the printing quality inspection apparatus concerning a 4th Example. 10 is a flowchart showing processing operations of a print quality inspection apparatus according to a fourth embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 11 ... Print instruction | indication part, 12 ... Print information transmission part, 13, 13a, 13b, 13c ... Paper feed tray, 14 ... Sheet conveyance path, 15 ... Printing part, 16 ... Discharge tray, 17 ... Print defective sheet discharge tray, 18 ... Sheet reversing section 20, 20B... Print quality inspection apparatus main body section 21... Storage section 210, 210a, 210b... One page previous print image storage section 211, 211a, 211b. , 212b... One-sheet previous print image storage unit, 213a, 213b... One-sheet previous read image storage unit, 22, 22a, 22b, 23, 23a, 23b... Differential image generation unit, 24. , 26 ... control unit, 27 ... image reading unit, 28, 28a, 28b, 28c ... sheet set detection unit, 29 ... discharge tray switching unit, 100, 100A, 100B ... print processing system

Claims (11)

In a print quality inspection apparatus that inspects the print quality of a printing apparatus that further prints image data on a preprinted sheet on which preprint information has been printed in advance,
Image reading means for reading an image of a preprinted sheet after the image data is printed by the printing apparatus;
After reading the image of the preprinted sheet after printing the nth page by the image reading means, the difference information between the image data of the nth page to be printed and the image data of the (n-1) th page, and n by the image reading means The difference information between the read image data of the page and the read image data of the (n−1) th page is compared, and based on the comparison result, the nth page or the (n−1) th page is printed on the preprinted sheet. A print quality inspection apparatus comprising: an image inspection processing unit that outputs a quality determination result. Attached to a printing apparatus having at least one paper feed tray that is a paper feed source of the preprinted sheet,
Sheet set detection means for detecting that the pre-printed sheet is set in the paper feed tray;
A discriminating means for discriminating whether or not a sheet is set in the paper feed tray at the start of printing;
When the sheet is set in the paper feed tray, the image quality is not judged after the image of the preprinted sheet after printing the first page by the image reading unit, and the preprinted sheet after printing the second page is printed. The print quality inspection apparatus according to claim 1, further comprising: a control unit that controls to perform the print quality determination after the image is read. Attached to a printing apparatus having at least one paper feed tray that is a paper feed source of the preprinted sheet,
A paper source recognition unit for recognizing which of the plurality of paper trays is a paper source based on a print instruction;
Determining means for determining whether or not the paper source is different from the paper source at the end of the previous printing at the start of printing;
If the paper supply source is different from the paper supply source at the end of the previous printing, the image reading unit does not perform the print quality determination after the image of the preprinted sheet is printed after the first page is printed. And a control means for controlling to perform the print quality determination after reading the image of the print sheet, and for each of a plurality of paper feed sources, the print quality of the preprinted sheet fed from the paper feed source is inspected. The print quality inspection apparatus according to claim 1. Sheet set detection means for detecting that the pre-printed sheet is set in the paper feed tray;
A discriminating means for discriminating whether or not a sheet has been set in the paper feed tray of the pre-printed sheet feed source to be printed at the start of printing;
The control means does not perform the print quality determination after reading the image of the preprinted sheet after printing the first page by the image reading means when the sheet is set in the paper supply tray as the paper supply source. The print quality inspection apparatus according to claim 3, wherein control is performed so as to perform the print quality determination after reading an image of a preprinted sheet after printing a page. Printing quality of a printing apparatus having a plurality of paper feed trays on which preprinted sheets on which preprinted information has been printed are set, and further printing image data on the preprinted sheets fed from the respective paper feed trays In the print quality inspection device that inspects
Paper source recognition means for recognizing which of the plurality of paper trays is a paper source when printing is started;
Image reading means for reading an image of a preprinted sheet after the image data is printed by the printing apparatus;
An image data of the nth page to be printed and the image data of the (n−1) th page after the image reading of the preprinted sheet after the nth page printing by the image reading unit is provided corresponding to the paper feed tray. A plurality of first difference information generating means for generating the difference information;
A plurality of second difference information generation means provided corresponding to the paper feed tray and for generating difference information between the read image data of the nth page and the read image data of the (n−1) th page by the image reading means. When,
The difference information generated by the first difference information generation unit is compared with the difference information generated by the second difference information generation unit, and the nth page or (n -1) image inspection processing means for outputting the print quality judgment result of the page;
When printing on a pre-printed sheet fed from a paper source recognized by the recognition unit, difference information is generated by the first difference information generating unit and the second difference information generating unit corresponding to the paper source. Control means for controlling the image inspection processing means to output the print quality judgment result based on the comparison result of the difference information, and a plurality of paper feed sources are fed from the paper feed source. A print quality inspection apparatus for inspecting print quality of a preprinted sheet. Sheet set detection means for detecting that the pre-printed sheet is set in the paper feed tray;
A discriminating means for discriminating whether or not a sheet has been set in the paper feed tray of the paper feed source at the start of printing;
The control means does not perform the print quality determination after reading the image of the preprinted sheet after printing the first page by the image reading means when the sheet is set in the paper supply tray as the paper supply source. The print quality inspection apparatus according to claim 5, wherein control is performed so as to perform the print quality determination after reading an image of a preprinted sheet after printing a page. In a print quality inspection device that inspects the print quality of a printing device that further prints image data on both sides of a preprinted sheet with preprinted information printed on both sides,
Recognizing means for recognizing whether the image data input as a printing target is for front side printing or back side printing;
Image reading means for reading the images of the front and back surfaces of the post-printing preprinted sheet after the front surface printing image data is printed on the front surface and after the back surface printing image data is printed on the back surface, respectively.
After reading the image of the pre-printed sheet after the n-th surface printing by the image reading means, difference information between the n-th surface printing image data and the (n-1) -th surface printing image data, and the image reading means And the difference information between the n-th surface-read image data and the (n-1) -th surface-read image data is generated and compared, and the pre-printed sheet after the back-side printing of the n-th surface by the image reading means is performed. After the image reading, the difference information between the nth backside printing image data and the (n-1) th backside printing image data, the nth backside reading image data by the image reading means, and the (n-1) th sheet. Image inspection processing means for generating and comparing difference information of the back side read image data of the eyes, and outputting print quality determination results for the front and back surfaces of the preprinted sheet based on the comparison results, respectively. Features to do Print quality inspection device. Attached to a printing apparatus having at least one paper feed tray that is a paper feed source of the preprinted sheet,
Sheet set detection means for detecting that the pre-printed sheet is set in the paper feed tray;
A discriminating means for discriminating whether or not a sheet is set in the paper feed tray at the start of printing;
When the sheet is set in the sheet feeding tray, the printing is performed after the image reading unit reads the image of the preprinted sheet after the first front surface printing and after the image reading of the preprinted sheet after the first back surface printing. No quality determination is performed, and control is performed so as to perform the print quality determination after reading the image of the preprinted sheet after the second front surface printing by the image reading unit and after reading the image of the preprinted sheet after the second back surface printing. The print quality inspection apparatus according to claim 7, further comprising: In a print quality inspection method for inspecting the print quality of a printing apparatus that further prints image data on a preprinted sheet on which preprint information has been printed in advance,
An image reading step of reading an image of a preprinted sheet after the image data is printed by the printing apparatus;
After reading the image of the preprinted sheet after printing the nth page in the image reading step, the difference information between the image data of the nth page to be printed and the image data of the (n-1) th page, and the image reading means The difference information between the read image data of the nth page and the read image data of the (n−1) th page is compared, and based on the comparison result, the nth page or the (n−1) th page of the preprinted sheet is compared. An image inspection processing step for outputting a print quality judgment result. Printing quality of a printing apparatus having a plurality of paper feed trays on which preprinted sheets on which preprinted information has been printed are set, and further printing image data on the preprinted sheets fed from the respective paper feed trays In the print quality inspection method for inspecting
A paper source recognition step for recognizing which of the plurality of paper trays is a paper source when printing is started;
An image reading step of reading an image of a preprinted sheet after the image data is printed by the printing apparatus;
N-page image data and (n-1) -page image data to be printed after reading the image of the pre-printed sheet after printing the n-th page in the image reading step. A first difference information generation step for generating the difference information of
A second difference information generation step which is performed corresponding to the paper feed tray and generates difference information between the read image data of the nth page and the read image data of the (n−1) th page by the image reading step;
The difference information generated by the first difference information generation step is compared with the difference information generated by the second difference information generation step, and the nth page or (n -1) an image inspection processing step for outputting a print quality judgment result for the page;
When printing on a preprinted sheet fed from the paper feed source recognized in the recognition step, difference information is generated by the first difference information generation step and the second difference information generation step corresponding to the paper feed source, respectively. A print quality inspection method for performing a print quality inspection on a pre-printed sheet fed from the paper feed source for each of a plurality of paper feed sources by performing the image inspection processing step after the caulking . In a print quality inspection method for inspecting the print quality of a printing apparatus that further prints image data on both sides of a preprinted sheet with preprinted information printed on both sides,
A recognition step for recognizing whether the image data to be input for printing is for front side printing or back side printing;
An image reading step for reading the front and back images of the pre-printed pre-printed sheet after the front surface printing image data is printed on the front surface and after the back surface printing image data is printed on the back surface, respectively.
After image reading of the pre-printed sheet after n-th surface printing in the image reading step, difference information between n-th surface printing image data and (n−1) -th surface printing image data, and the image reading means The difference information between the n-th surface read image data and the (n−1) -th surface read image data is generated and compared, and the pre-printed sheet after the back printing of the n-th surface in the image reading step is performed. After the image reading, the difference information between the nth backside printing image data and the (n-1) th backside printing image data, the nth backside reading image data by the image reading means, and the (n-1) th sheet. Image inspection processing step for generating and comparing difference information of the back side read image data of the eye, and outputting print quality determination results for the front and back sides of the preprinted sheet, respectively, based on the comparison results A print quality inspection method characterized by the above.

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