Image forming apparatus

Abstract

The invention provides an image forming apparatus. In the image forming apparatus, even if a white paper page is included, the order of the page can be checked. An image forming apparatus (1) is provided with: a page information generation unit (13) that assigns page information to image data received by a data input unit (21); a page information storage unit (24) that stores page information; a front page information storage unit (25) that stores front page information, which is page information of a front page, on each of the front surface and the back surface; a conveyance control unit (30) that determines the insertion of a white paper page during printing; a page information comparison unit (27) that checks the order of the pages on the front surface and the back surface on the basis of the difference between the page information and the front page information; and a page information addition unit (26) that, when a white paper page is inserted into the back surface of the double-sided printing in the printing case, adds the addition value to the front page information by referring to an addition table (121) that holds the addition value corresponding to the back surface of the double-sided printing in the printing case.

Description

Technical Field

[0001] The present invention relates to an image forming apparatus. Background Art

[0002] Conventionally, there has been a technique for detecting a disorder in the page order or a missing page of a printed page in an image forming apparatus. For example, a printing apparatus has been proposed in which page numbers are attached as header information to a plurality of bitmap data loaded by an image loading unit, the page numbers read from the header information are compared with the pages to be printed next, and if they do not match, printing is stopped (see, for example, Patent Document 1).

[0003] Prior Art Documents Patent Documents Patent Document 1: Japanese Unexamined Patent Application Publication No. 2005-014364 Summary of the Invention Problems to be Solved by the Invention However, when printing a blank sheet (i.e., when no printing is performed), an image data generation unit that sends image data loaded in a printable form by a data loading unit to a head drive control unit that drives a print head does not generate page information, or even if page information is generated, it is not transmitted to the image data generation unit, and thus the sequentiality of the next page cannot be normally determined.

[0004] Here, there are the following two types of printing of blank sheets. One is the final page in double-sided printing of an odd-page task and the blank sheet inserted on the image forming apparatus side when inserting a lining sheet (hereinafter, referred to as a printed blank sheet). The other is a blank sheet actually included in a printed document or the like and inserted according to a user's instruction (hereinafter, referred to as a user blank sheet).

[0005] Since the printed blank sheet does not include data in the task, image data loading processing is not performed, and page information is not generated. On the other hand, since the user blank sheet includes data in the task, image data loading processing is performed, and page information is also generated. However, such generated page information is not transmitted to the image data generation unit in the case of a blank sheet page, just like the image data of the blank sheet page.

[0006] Therefore, for example, in the case where the fourth page becomes a printed blank sheet in a three-page multiple double-sided printing task, since the page on which page information is generated on the back after the back of the first sheet (the second page) becomes the back of the third sheet (the fifth page), the sequentiality of the pages cannot be checked.

[0007] In addition, in the case of a user blank sheet, since image data loading processing is performed, page information is generated, but this page information is not transmitted to the image data generation unit, and thus, similarly, the sequentiality of the pages cannot be checked.

[0008] An object of the present invention is to provide an image forming apparatus capable of checking the page order even when white paper pages are included.

[0009] Means for Solving the Problem In one aspect, an image forming apparatus includes: a data input unit that receives image data; a data loading unit that loads the image data received by the data input unit into a printable form; a page information generation unit that assigns page information to the image data received by the data input unit; a page information storage unit that stores the page information; a previous page information storage unit that stores, in each of the front and back sides, previous page information that is the page information of the previous page; a conveyance control unit that determines the insertion of white paper pages in the case of printing; a page information comparison unit that checks the page order based on the difference between the page information and the previous page information in each of the front and back sides; and a page information addition unit that, when the white paper pages in the case of printing are inserted on the back side of double-sided printing, refers to an addition table that holds an addition value corresponding to the back side of double-sided printing in the case of printing, and adds the addition value to the previous page information.

[0010] Advantageous Effects of the Invention According to the above aspect, the page order can be checked even when white paper pages are included. Description of the Drawings

[0011] Figure 1 is a functional block diagram for explaining an image forming apparatus according to an embodiment.

[0012] Figure 2 is a front view showing the internal configuration of an image forming apparatus according to an embodiment.

[0013] Figure 3 is a block diagram showing the control configuration of an image forming apparatus according to an embodiment.

[0014] Figure 4 is a diagram showing an example of an addition table in an embodiment.

[0015] Figure 5 in (a), Figure 5 in (b) are diagrams for explaining the printing order of the front and back sides for each paper size in an embodiment.

[0016] Figures 6a - 6d is a diagram for explaining an example of adding page numbers in an embodiment.

[0017] Description of Reference Numerals 1: Image forming apparatus; 10: Controller; 11: Data input unit; 12: Data loading unit; 13: Page information generation unit; 20: Image data generation unit; 21: Image receiving unit; 22: Image processing unit; 23: Image sending unit; 24: Page information storage unit; 25: Previous page information storage unit; 26: Page information addition unit; 27: Page information comparison unit; 30: Conveying control unit; 40: Head drive control unit; 50: Print head; 60: Paper feeding unit; 61: External paper feeding unit; 61a: Paper feeding tray; 61b: Paper feeding roller; 61c: Sheet separator; 62: First paper feeding unit; 63: Second paper feeding unit; 64: Third paper feeding unit; 62a, 63a, 64a: Paper feeding tray; 62b, 63b, 64b: Paper feeding roller; 70: Conveying unit; 71: Conveying roller; 72: Path switching unit; 73: Return roller; 74: Return path; 80: Printing and conveying unit; 81: Pulley; 82: Belt; 83: Suction fan; 90: Paper discharging unit; 91: Paper discharging tray; 92: Paper discharging roller; 110: Control unit; 120: Storage unit; 121: Addition table; 130: Interface unit; P: Paper; T: Conveying direction. Detailed implementation mode

[0018] Hereinafter, an image forming apparatus according to an embodiment of the present invention will be described with reference to the accompanying drawings.

[0019] Figure 1 It is a functional block diagram for explaining the image forming apparatus 1 according to an embodiment.

[0020] As Figure 1 shown, the image forming apparatus 1 includes a controller 10, an image data generation unit 20, a conveying control unit 30, a head drive control unit 40, and a print head 50.

[0021] The controller 10 has a data input unit 11, a data loading unit 12, and a page information generation unit 13.

[0022] The data input unit 11 receives image data (compressed image data) from an external device such as a user terminal, a print control device, or a scanner, for example. For example, the data input unit 11 can obtain image data from an external device via the interface unit 130 described later.

[0023] The data loading unit 12 loads the image data received by the data input unit 11 into a printable form (for example, bitmap form).

[0024] The page information generation unit 13 assigns page information to the image data received by the data input unit 11. This page information is, for example, a value (page number) that increments by 1. It should be noted that hereinafter, the page information will be described as a page number that increments by 1. However, as long as the page information addition unit 26 and the page information comparison unit 27 described later can recognize the order of the page information, the page information can also be symbols such as English letters, or the increment value can be a number other than 1.

[0025] The image data generation unit 20 includes an image reception unit 21, an image processing unit 22, an image transmission unit 23, a page information storage unit 24, a previous page information storage unit 25, a page information addition unit 26, and a page information comparison unit 27.

[0026] The image reception unit 21 receives from the controller 10 the data in which page information has been assigned to the image data loaded through the data loading unit 12 by the page information generation unit 13. The image reception unit 21 transmits the loaded image data in the received data to the image processing unit 22 and stores the page information in the page information storage unit 24.

[0027] The image processing unit 22 performs known image processing such as image adjustment on the image data transmitted from the image reception unit 21.

[0028] The image transmission unit 23 transmits the image data that has undergone image processing by the image processing unit 22 to the head drive control unit 40.

[0029] The page information storage unit 24 stores the page information transmitted from the image reception unit 21.

[0030] The previous page information storage unit 25 stores, in each of the front and back sides, the previous page information that is the page information of the previous page. The previous page information storage unit 25 preferably obtains, for example, information on whether the previous page (target page) is the front side or the back side from the conveyance control unit 30. It should be noted that the page information storage unit 24 and the previous page information storage unit 25 may also be a single storage unit. In this case, the storage unit stores the page information and the previous page information in an identifiable manner.

[0031] The page information addition unit 26 refers to the addition table 121 showing the addition values for the single-sided printing case and the double-sided printing case in each of the white paper in the printing case and the white paper in the user case. Figure 4 Moreover, the page information addition unit 26 reads out the previous page information from the previous page information storage unit 25, adds it to the addition value, and writes the result back to the previous page information storage unit 25.

[0032] The page information comparison unit 27 checks the sequentiality of pages based on the difference between the page information and the previous page information for each of the front and back sides. The page information comparison unit 27 preferably notifies the conveyance control unit 30 etc. and stops printing when it determines that there is an error in the sequence. Note that as long as the page information comparison unit 27 can recognize the printing sequence of the front and back sides, the comparison target of the page information on the front side can be the page information on the back side printed previously, and the comparison target of the page information on the back side can also be the page information on the front side printed previously.

[0033] However, in the case of duplex printing, since the number of sheets that can be conveyed simultaneously varies depending on the paper size, there is a difference in the time point from when printing starts on the front side until printing starts on the back side. For example, as shown in (a) in Figure 5 where the paper size is relatively large, printing is performed in the order of the front side of the first sheet (page 1), the front side of the second sheet (page 3), the back side of the first sheet (page 2), the front side of the third sheet (page 5), the back side of the second sheet (page 4), the front side of the fourth sheet (page 7), the back side of the third sheet (page 6), the front side of the fifth sheet (page 9), the back side of the fourth sheet (page 8). In this case, the printing of the back side of the first sheet (page 2) is performed after the printing of the front side of the first sheet (page 1) and the front side of the second sheet (page 3).

[0034] On the other hand, as shown in (b) in Figure 5 where the paper size is relatively small, printing is performed in the order of the front side of the first sheet (page 1), the front side of the second sheet (page 3), the front side of the third sheet (page 5), the front side of the fourth sheet (page 7), the back side of the first sheet (page 2), the front side of the fifth sheet (page 9), the back side of the second sheet (page 4). In this case, the printing of the back side of the first sheet (page 2) is performed after the printing of the front sides of the first to fourth sheets (pages 1, 3, 5, 7).

[0035] Therefore, the page information comparison unit 27 receives the information of the front and back sides from the conveyance control unit 30 for each of the front and back sides, compares the page information among the front sides for the front side, and compares the page information among the back sides for the back side to determine the sequentiality. As shown in (a) in Figure 5 and (b) in Figure 5 , in the case of duplex printing, since the difference in the page information among the front sides and among the back sides should be 2 regardless of the printing time point of the back side, if the difference is 3 or more, the page information comparison unit 27 can determine that it is an error. Note that in the case of single-sided printing, since the difference should be 1, if the difference is 2 or more, the page information comparison unit 27 can determine that it is an error.

[0036] The conveyance control unit 30 obtains information such as single-sided printing or double-sided printing, paper size, and whether the image data loaded by the data loading unit 12 is a blank page (blank page in the user's case) from the controller 10. In addition, the conveyance control unit 30 determines the insertion of a blank page according to the printing situation, such as the last page of double-sided printing of an odd-numbered page task or when inserting a pre-set interleaving paper. In addition, the conveyance control unit 30 performs Figure 2 The control of the transport unit 70 described below is shown.

[0037] The head driving control unit 40 controls the print head 50 based on the image data received from the image transmission unit 23. The head driving control unit 40 has one or more processors functioning as a calculation processing device, similar to the control unit 110 described later.

[0038] The print head 50 is, for example, a line-type inkjet head having one or more head modules including a plurality of nozzles for discharging ink. Figure 2 The ink is discharged onto the paper P shown. Thus, the print head 50 prints on the paper P. It should be noted that the printing method of the print head 50 is not limited to the inkjet method, and any printing method can be adopted.

[0039] Figure 2 is a front view showing the internal structure of the image forming apparatus 1, Figure 3 : is a block diagram showing a control structure of the image forming apparatus 1 .

[0040] like Figure 2 As shown, the image forming apparatus 1 further includes a paper feeding unit 60 , a conveying unit 70 , a printing and conveying unit 80 , and a paper discharging unit 90 .

[0041] It should be noted that the paper P in this embodiment is an example of a medium, and the medium may be a sheet-shaped medium made of a material other than paper, a medium with a folded portion such as an envelope, etc. Therefore, in this specification, paper supply is an example of supply, and paper discharge is an example of discharge. Therefore, paper supply can be replaced by supply, paper discharge can be replaced by discharge, and paper can be replaced by medium. It should be noted that in Figure 2 In the figure, the external paper supply unit 61 and the conveying path of the paper P from the first to third internal paper supply units 62, 63, 64 to the paper discharge unit 90 are indicated by solid lines, and the return path 74 for double-sided printing is indicated by dotted lines.

[0042] The paper supply unit 60 includes an external paper supply unit 61 and first to third internal paper supply units 62 to 64. The external paper supply unit 61 includes a paper supply tray 61a, a paper supply roller 61b, and a paper separating plate 61c. The external paper supply unit 61 is configured to be exposed to the outside of the device housing and supply the paper P into the device housing.

[0043] In the paper supply tray 61a, the paper P before printing is loaded. The paper supply roller 61b is arranged in two in the conveying direction T of the paper P, for example, and extracts and conveys the uppermost paper P among the multiple papers P loaded in the paper supply tray 61a. The paper separating plate 61c sandwiches the paper P between itself and the paper supply roller 61b to separate the papers one by one.

[0044] The first internal paper supply unit 62, the second internal paper supply unit 63, and the third internal paper supply unit 64 are arranged in order from top to bottom inside the device housing. The first internal paper supply unit 62, the second internal paper supply unit 63, and the third internal paper supply unit 64 respectively include paper supply trays 62a, 63a, 64a for loading the paper P before printing, and paper supply rollers 62b, 63b, 64b for extracting and conveying the uppermost paper P among the multiple papers P loaded in the paper supply trays 62a, 63a, 64a.

[0045] The conveying unit 70 includes multiple conveying rollers 71, a path switching unit 72, a reversing roller 73, and a reversing path 74. These conveying rollers 71, path switching unit 72, reversing roller 73, and reversing path 74 are used to circulate the paper P in duplex printing so that the paper P can be re-supplied to the print head 50 for conveying.

[0046] The conveying rollers 71 are arranged in pairs in the conveying path of the paper P to sandwich the paper P and convey the paper P.

[0047] The path switching unit 72 switches the conveying path of the paper P that has been printed by the print head 50 to a path leading to the paper discharge unit 90 and the reversing path 74. The path switching unit 72 is a baffle, for example. The reversing roller 73 reverses and conveys the paper P in the reversing path 74 to turn the front and back of the paper P over.

[0048] The printing and conveying unit 80 is configured to face the print head 50 and convey the paper P. The printing and conveying unit 80 includes multiple pulleys 81, a belt 82 mounted on these pulleys 81, and an attracting fan 83 that attracts air through multiple holes provided in the belt 82 to adsorb the paper P to the belt 82. As the printing and conveying unit 80, it can be a printing and conveying unit having conveying members other than the belt 82 such as rollers, or a printing and conveying unit that does not adsorb the paper P. It should be noted that the printing and conveying unit 80 can be regarded as a part of the conveying unit 70 that conveys the paper P together with the conveying rollers 71, etc.

[0049] The paper discharging unit 90 includes a paper discharge tray 91 and a paper discharge roller 92. The paper discharging unit 90 is an example of a discharge unit, and is configured to be exposed to the outside of the device housing, and discharge the paper P to the outside of the device housing.

[0050] In the paper discharge tray 91, the printed paper P is loaded. The paper discharge roller 92 is arranged, for example, in a pair of upper and lower ones, and conveys the paper P toward the paper discharge tray 91.

[0051] Figure 3 The control unit 110 shown has one or more processors (such as a CPU: Central Processing Unit, central processing unit) that function as arithmetic processing devices. This processor executes a predetermined program, for example, by reading from the storage unit 120 or a storage medium (non-temporary computer-readable recording medium) that is detachable from the image forming apparatus 1, and functions as Figure 1 the controller 10, the image data generation unit 20, the conveyance control unit 30, etc. shown. In this way, the image forming apparatus 1 (the control unit 110 and the storage unit 120) functions as a computer that executes a program. It should be noted that it is preferable to respectively configure one or more processors corresponding to the controller 10, the image data generation unit 20, and the conveyance control unit 30, but it is also possible to configure a processor that combines multiple ones of the controller 10, the image data generation unit 20, and the conveyance control unit 30.

[0052] The storage unit 120 includes, for example, a ROM (Read Only Memory, read-only semiconductor memory) that pre-records a predetermined control program, a RAM (Random Access Memory, random access semiconductor memory) that can be written and read at any time and is used as a working storage area as needed when the processor executes various control programs, and one or more other memories. The storage unit 120 functions as the page information storage unit 24 and the front page information storage unit 25 together with the control unit 110.

[0053] The interface unit 130 exchanges various information with external devices such as user terminals, print control devices, and scanners. For example, the interface unit 130 receives a print job including image data from a user terminal, a print control device, etc.

[0054] Next, a description will be given with reference to Figures 6a - 6d an example of adding page numbers.

[0055] First, in Figure 6aIn the case of single-sided printing and a blank sheet of paper in the printing scenario, in the blank sheet of paper in the printing scenario, there is no need for the loading process based on the data loading unit 12, and no page number is assigned based on the page information generation unit 13. Therefore, when the third sheet of paper is a blank page (illustrated by a dotted line), the fourth sheet of paper corresponds to the third page. For the fourth sheet of paper, the difference between the page number 3 assigned by the page information generation unit 13 and held by the page information storage unit 24 and the page number 2 (the second sheet of paper) held by the previous page information storage unit 25 is 1. Then, since the page information comparison unit 27 can determine that it is an error if the difference is 2 or more in the case of single-sided printing, in the case of a difference of 1, it is determined that the page sequence is normal. Therefore, in the case of single-sided printing and a blank sheet of paper in the printing scenario, the page information addition unit 26 may not add to the added value either.

[0056] Next, in Figure 6b In the case of single-sided printing and a blank sheet of paper in the user scenario, in the blank sheet of paper in the user scenario, the loading process based on the data loading unit 12 and the assignment of page numbers based on the page information generation unit 13 are performed. However, since it is a blank page, no data is sent from the controller 10 (data loading unit 12 and page information generation unit 13) to the image data generation unit 20 (image receiving unit 21). Therefore, when the third sheet of paper is a blank page, for the fourth sheet of paper, the difference between the page number 4 assigned by the page information generation unit 13 and held by the page information storage unit 24 and the page number 2 (the second sheet of paper) held by the previous page information storage unit 25 is 2. Then, since the page information comparison unit 27 can determine that it is an error if the difference is 2 or more in the case of single-sided printing, in the case of a difference of 2, it is determined that the page sequence is incorrect.

[0057] Therefore, for the third sheet of paper in the user scenario blank sheet of paper, the page information addition unit 26 refers to Figure 4 the addition table 121 shown, adds the “+1” corresponding to single-sided printing and the user scenario blank sheet of paper and the page number 2 held by the previous page information storage unit 25, and uses it as the page number 3. Thus, for the fourth sheet of paper, the difference between the page number 4 assigned by the page information generation unit 13 and held by the page information storage unit 24 and the page number 3 (the third sheet of paper) held by the previous page information storage unit 25 is 1. Therefore, the page information comparison unit 27 can determine that the page sequence is normal.

[0058] Next, an explanation will be given for Figure 6c and Figure 6d the double-sided printing shown. Here, an example where the front and back are printed alternately will be used for the explanation. As shown in (a) in the above Figure 5 and (b) in 5, the printing time point of the back changes according to the paper size. If the page sequence is checked for each of the front and back, the printing time point of the back has no effect.

[0059] Next, in Figure 6c the case where the backs of the second and fourth sheets in the duplex printing task with multiple copies of 3 pages are blank sheets in the printing situation, in the blank sheets in the printing situation, there is no need for the loading process based on the data loading unit 12, and no page number is assigned based on the page information generation unit 13. Therefore, after the page information generation unit 13 assigns page 3 to the front of the second sheet, it assigns page 4 to the front of the third sheet. Similarly, after the page information generation unit 13 assigns page 6 to the front of the fourth sheet, it assigns page 7 to the front of the fifth sheet. Then, for the backs of the first, third, and fifth sheets, the page information generation unit 13 assigns pages 2, 5, and 8. Since the page information comparison unit 27, as described above, in the case of duplex printing, in each of the front and back sides, if the difference is 3 or more, it can be determined as an error. Therefore, in the case of a difference of 3, it is determined that the page order is incorrect.

[0060] Thus, for the backs of the second and fourth sheets of the blank sheets in the printing situation, the page information addition unit 26 refers to Figure 4 the addition table 121 shown, and adds the “+1” corresponding to duplex printing and blank sheets in the printing situation to the page numbers 2 and 5 held by the previous page information storage unit 25, as page numbers 3 and 6. Thus, for the backs of the third and fifth sheets, the difference between the page numbers 5 and 8 assigned by the page information generation unit 13 and held by the page information storage unit 24 and the page numbers 3 and 6 (backs of the second and fourth sheets) held by the previous page information storage unit 25 is 2. Therefore, the page information comparison unit 27 can determine that the page order is normal.

[0061] Next, in Figure 6d the case where the backs of the second and fourth sheets in the duplex printing task with multiple copies of 4 pages are blank sheets in the user situation, as described above for the blank sheets in the user situation, the loading process based on the data loading unit 12 and the assignment of page numbers based on the page information generation unit 13 are performed. However, since they are blank pages, no data is sent from the controller 10 (data loading unit 12 and page information generation unit 13) to the image data generation unit 20 (image receiving unit 21). Therefore, in the case where the backs of the second and fourth sheets are blank pages, for the back pages of the third and fifth sheets, the difference between the page numbers 6 and 10 assigned by the information generation unit 13 and held by the page information storage unit 24 and the page numbers 2 and 6 (backs of the first and third sheets) held by the previous page information storage unit 25 is 4. Then, since the page information comparison unit 27, in the case of duplex printing, if the difference is 3 or more, it can be determined as an error. Therefore, in the case of a difference of 4, it is determined that the page order is incorrect.

[0062] Therefore, for the back sides of the second and fourth sheets of the user-case blank paper, the page information addition unit 26 refers to Figure 4 the addition table 121 shown in Figure 4 , adds the “+2” corresponding to double-sided printing and the user-case blank paper to the page numbers 2 and 6 held by the previous page information storage unit 25, and obtains page numbers 4 and 8. Thus, for the third and fifth sheets of paper, the difference between the page numbers 6 and 10 assigned by the page information generation unit 13 and held by the page information storage unit 24 and the page numbers 4 and 8 (the back sides of the second and fourth sheets of paper) held by the previous page information storage unit 25 is 2. Therefore, the page information comparison unit 27 can determine that the page order is normal.

[0063] It should be noted that in the above description, an example in which the page information addition unit 26 adds the addition value to the previous page information in each of the printing-case blank paper and the user-case blank paper has been described. However, it may also be that the page information addition unit 26 adds the addition value to the previous page information only in one of the printing-case blank paper and the user-case blank paper.

[0064] In the present embodiment described above, the image forming apparatus 1 includes: a data input unit 11 that receives image data; a data loading unit 12 that loads the image data received by the data input unit 11 into a printable form; a page information generation unit 13 that assigns page information to the image data received by the data input unit 11; a page information storage unit 24 that stores page information; a previous page information storage unit 25 that stores, in each of the front side and the back side, the previous page information that is the page information of the previous page; a conveyance control unit 30 that determines the insertion of blank pages in the printing case; a page information comparison unit 27 that checks the page order based on the difference between the page information and the previous page information in each of the front side and the back side; and a page information addition unit 26 that, as Figure 6c shown in Figure 6c , when a blank page in the printing case is inserted on the back side of double-sided printing, refers to the addition table 121 that holds the addition value corresponding to the back side of double-sided printing in the printing case, and adds the addition value to the previous page information.

[0065] Further, from the perspective of a page information comparison method for checking the page order by a computer, the page information comparison method includes the following: receiving image data; loading the received image data into a printable form; assigning page information to the received image data; storing the assigned page information; storing, in each of the front side and the back side, the previous page information that is the page information of the previous page; determining the insertion of blank pages in the printing case; checking the page order based on the difference between the page information and the previous page information in each of the front side and the back side; and as Figure 6c shown in Figure 6c , when a blank page in the printing case is inserted on the back side of double-sided printing, referring to the addition table 121 that holds the addition value corresponding to the back side of double-sided printing in the printing case, and adding the addition value to the previous page information.

[0066] In addition, from the perspective of the program, the program enables the computer to perform the following functions: a function of accepting image data; a function of loading the accepted image data into a printable form; a function of assigning page information to the accepted image data; a function of saving the assigned page information; a function of saving, in each of the front and back sides, the previous page information that is the page information of the previous page; a function of determining the insertion of blank pages in the case of printing; a function of checking the page sequence in each of the front and back sides based on the difference between the page information and the previous page information; as Figure 6c shown, in the case where a blank page in the printing case is inserted on the back side of double-sided printing, referring to the addition table 121 that holds the added value corresponding to the back side of double-sided printing in the printing case, a function of adding the added value to the previous page information.

[0067] However, in the case of the final page during double-sided printing of an odd-page task and when inserting a liner, in the printing-case blank paper inserted on the image forming apparatus side, there is no need for the loading process of the data loading unit 12, and no page number is assigned based on the page information generation unit 13. Therefore, as Figure 6c shown, on the back sides of the 1st, 3rd, and 5th sheets of paper, page numbers 2, 5, and 8 are assigned by the page information generation unit 13, and the difference between the page numbers of the previous pages on the back sides becomes 3. Since it exceeds 2 pages, it is determined as an error. In contrast, in the present embodiment, for the back sides of the 2nd and 4th sheets of paper in the printing-case blank paper, the page information addition unit 26 refers to Figure 4 the addition table 121 shown, and adds the “+1” corresponding to double-sided printing and being printing-case blank paper to the page numbers 2 and 5 held by the previous page information storage unit 25 as page numbers 3 and 6. As a result, for the back sides of the 3rd and 5th sheets of paper, the difference between the page numbers 5 and 8 assigned by the page information generation unit 13 and held by the page information storage unit 24 and the page numbers 3 and 6 (the back sides of the 2nd and 4th sheets of paper) held by the previous page information storage unit 25 becomes 2. Therefore, the page information comparison unit 27 can determine that the page sequence is normal. Therefore, according to the present embodiment, even when including blank pages in the printing case, the page sequence can be checked. Therefore, even for printed matter such as a printed matter sealed in an envelope by mail coating and difficult to visually confirm, abnormalities can be detected on the image forming apparatus 1 side, preventing the occurrence of misenclosure and the like.

[0068] In addition, in the present embodiment, the addition table 121 holds the added value corresponding to single-sided printing or double-sided printing in the user case. In the case where the image data received by the data input unit 11 is a blank page in the user case, the page information addition unit 26 refers to the addition table 121 and adds the added value to the previous page information.

[0069] In addition, in terms of the page information comparison method, the addition table 121 holds addition values corresponding to single-sided printing or double-sided printing in the user's situation. Adding the addition value to the previous page information includes: when the image data received by the data input unit 11 is a blank page in the user's situation, referring to the addition table 121 and adding the addition value to the previous page information.

[0070] In addition, from the perspective of the program, the addition table 121 holds addition values corresponding to single-sided printing or double-sided printing in the user's situation. The function of adding the addition value to the previous page information includes: when the image data received by the data input unit 11 is a blank page in the user's situation, referring to the addition table 121 and adding the addition value to the previous page information.

[0071] However, in fact, in the printed documents, etc., the user's situation blank pages inserted according to the user's instructions, along with the loading process based on the data loading unit 12, the page numbers are assigned by the page information generation unit 13, but the page numbers are not transmitted to the image data generation unit 20. Therefore, as Figure 6b shown, in single-sided printing, when the third sheet is a blank page, for the fourth sheet, the difference between the page number 4 assigned by the page information generation unit 13 and held by the page information storage unit 24 and the page number 2 (the second sheet) held by the previous page information storage unit 25 is 2, which is determined to be an error. In addition, as Figure 6d shown, in double-sided printing, when the backs of the second and fourth sheets are blank pages, for the backs of the third and fifth sheets, the differences between the page numbers 6, 10 assigned by the page information generation unit 13 and held by the page information storage unit 24 and the page numbers 2, 6 (the backs of the first and third sheets) held by the previous page information storage unit 25 are 4, which is determined to be an error. In contrast, in the present embodiment, the page information addition unit 26 refers to the Figure 4 addition table 121 shown, and adds the "+1" corresponding to single-sided printing and being a blank page in the user's situation, or the "+2" corresponding to double-sided printing and being a blank page in the user's situation to the page number held by the previous page information storage unit 25. Thus, the page information comparison unit 27 can determine that the page order is normal. Therefore, according to the present embodiment, even if there are blank pages in the user's situation, the page order can be checked. Therefore, even for printed materials such as those enclosed in envelopes by mail coating, which are difficult to visually confirm, abnormalities can be detected on the side of the image forming apparatus 1, preventing the occurrence of misenclosure, etc.

[0072] It should be noted that the present invention is not limited to the above embodiments themselves, and during the implementation stage, the constituent elements can be deformed and embodied without departing from the gist thereof. In addition, various inventions can be formed by appropriately combining a plurality of constituent elements disclosed in the above embodiments. For example, all the constituent elements shown in the embodiments can also be appropriately combined. It is natural that various deformations and applications can be made within the scope of not departing from the gist of the invention as described above. Hereinafter, the invention described in the original technical solution of this application is attached.

[0073] [Supplementary Note 1] An image forming apparatus, characterized in that the image forming apparatus includes: a data input unit that receives image data; a data loading unit that loads the image data received by the data input unit into a printable form; a page information generation unit that assigns page information to the image data received by the data input unit; a page information storage unit that stores the page information; a previous page information storage unit that stores, in each of the front and back sides, the previous page information that is the page information of the previous page; a conveyance control unit that determines the insertion of blank pages in the case of printing; a page information comparison unit that checks the page sequence in each of the front and back sides based on the difference between the page information and the previous page information; and a page information addition unit that, when the blank page in the case of printing is inserted on the back side of double-sided printing, refers to an addition table that holds an addition value corresponding to the back side of double-sided printing in the case of printing, and adds the addition value to the previous page information.

[0074] [Supplementary Note 2] Based on the image forming apparatus described in Supplementary Note 1, characterized in that the addition table also holds addition values corresponding to single-sided printing or double-sided printing in the user case, when the image data received by the data input unit is a blank page in the user case, the page information addition unit refers to the addition table and adds the addition value to the previous page information.

[0075] [Supplementary Note 3] An image forming apparatus, characterized in that the image forming apparatus includes: a data input unit that receives image data; a data loading unit that loads the image data received by the data input unit into a printable form; A page information generation unit that assigns page information to the image data received by the data input unit; A page information storage unit that stores the page information; A previous page information storage unit that stores, in each of the front and back sides, the previous page information that is the page information of the previous page; A page information comparison unit that checks the page sequentiality based on the difference between the page information and the previous page information in each of the front and back sides; and A page information addition unit that, when the image data received by the data input unit is a blank page in the case of a user, refers to an addition table that holds addition values corresponding to single-sided printing or double-sided printing in the case of the user, and adds the addition value to the previous page information.

Claims

1. An image forming apparatus, characterized in that, the image forming apparatus includes: a data input unit that receives image data; a data loading unit that loads the image data received by the data input unit into a printable form; a page information generating unit that assigns page information to the image data received by the data input unit; a page information storage unit that stores the page information; a previous page information storage unit that stores, in each of the front and back sides, previous page information that is the previous page information of the page information; a conveyance control unit that determines the insertion of blank sheets in the case of printing; a page information comparison unit that checks the page sequence in each of the front and back sides based on the difference between the page information and the previous page information; and a page information addition unit that, when the blank sheet in the case of printing is inserted on the back side of double-sided printing, refers to an addition table that holds an addition value corresponding to the back side of double-sided printing in the case of printing, and adds the addition value to the previous page information.

2. The image forming apparatus according to claim 1, characterized in that, the addition table also holds addition values corresponding to single-sided printing or double-sided printing in the user case, and when the image data received by the data input unit is a blank sheet in the user case, the page information addition unit refers to the addition table and adds the addition value to the previous page information.

3. An image forming apparatus, characterized in that, the image forming apparatus includes: a data input unit that receives image data; a data loading unit that loads the image data received by the data input unit into a printable form; a page information generating unit that assigns page information to the image data received by the data input unit; a page information storage unit that stores the page information; a previous page information storage unit that stores, in each of the front and back sides, previous page information that is the previous page information of the page information; a page information comparison unit that checks the page sequence in each of the front and back sides based on the difference between the page information and the previous page information; and a page information addition unit that, when the image data received by the data input unit is a blank sheet in the user case, refers to an addition table that holds addition values corresponding to single-sided printing or double-sided printing in the user case, and adds the addition value to the previous page information.

Images