Printing system

Abstract

To provide a printing system that can reduce inconsistency between printed pages on a front face and a rear face, without printing an image additionally, while suppressing the system from being complicated in structure.SOLUTION: A print data generating part 11 generates print data for each page that are printed on papers respectively by a head unit 23 of an upstream-side printing device 3 and a head unit 43 of a downstream-side printing device 5, and applies time stamp information showing times at which the printing data have been generated, to the respective printing data. A comparing / determining part 58 calculates a time difference between a time shown by the time stamp information extracted by a time stamp extracting part 37 and a time shown by the time stamp information extracted by a time stamp extracting part 57, for respective papers on which the printing data are printed by the head units 23 and 43, so as to determine consistency between the page printed by the head unit 23 and the page printed by the head unit 43 on the basis of the calculated time difference.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a printing system. [Background technology]

[0002] 2. Description of the Related Art There is known a printing system that includes two printing devices, in which one printing device prints on the front side of a sheet of paper and then the other printing device prints on the back side of the sheet of paper, thereby performing double-sided printing.

[0003] In such a printing system, when the printing operation is stopped and a maintenance operation is performed, and then the printing operation is restarted, a mismatch between the front and back printed pages may occur.

[0004] Regarding such mismatches in printed pages, Patent Document 1 discloses a technology in which a first printer engine prints tandem check marks at check page intervals and a sensor provided in a second printer engine detects the tandem check marks to verify whether there is a mismatch in page correspondence between two printer engines. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2007-8143 A Summary of the Invention [Problem to be solved by the invention]

[0006] However, the technology of Patent Document 1 requires a sensor to detect the tandem check marks, which complicates the system configuration, and also requires additional printing of the tandem check marks, which are essentially unnecessary images.

[0007] The present invention has been made in consideration of the above, and aims to provide a printing system that can reduce inconsistencies in printed pages between the front and back sides while minimizing the complexity of the system configuration and without printing additional images. [Means for solving the problem]

[0008] In order to achieve the above-mentioned object, the printing system of the present invention is characterized in that it comprises a first printing unit that prints on paper, a second printing unit that prints on paper printed by the first printing unit, a print data generation unit that generates print data for each page that each of the first printing unit and the second printing unit prints on paper and adds generation time information indicating the time when the print data was generated to each print data, a first acquisition unit that acquires the generation time information of the print data when printing based on the print data by the first printing unit, a second acquisition unit that acquires the generation time information of the print data when printing based on the print data by the second printing unit, and a determination unit that calculates a time difference between the time indicated by the generation time information acquired by the first acquisition unit and the time indicated by the generation time information acquired by the second acquisition unit, for each piece of paper printed by the first printing unit and the second printing unit, and determines the consistency between the pages printed by the first printing unit and the pages printed by the second printing unit based on the calculated time difference. Effect of the Invention

[0009] According to the printing system of the present invention, it is possible to reduce inconsistencies in printed pages between the front and back sides while suppressing the complexity of the system configuration and without printing additional images. [Brief description of the drawings]

[0010] [Figure 1] 1 is a schematic configuration diagram of a printing system according to an embodiment. [Diagram 2] 2 is a block diagram showing configurations of a print control device, an upstream printing device, and a downstream printing device in the printing system shown in FIG. [Diagram 3] FIG. 4 is an explanatory diagram of print data. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. The same or equivalent parts and components are denoted by the same or equivalent reference numerals throughout the drawings.

[0012] Fig. 1 is a schematic diagram of a printing system according to an embodiment of the present invention, Fig. 2 is a block diagram showing the configurations of a print control device, an upstream printing device, and a downstream printing device of the printing system shown in Fig. 1.

[0013] As shown in FIG. 1, the printing system 1 according to this embodiment includes a paper feeder 2, an upstream printing device 3, an intermediate conveying device 4, a downstream printing device 5, a paper discharge device 6, and a print control device 7.

[0014] The paper feeder 2 feeds paper to the upstream printing device 3 .

[0015] The upstream printing device 3 prints on one side (front side) of the paper while transporting the paper fed from the paper feeder 2. The upstream printing device 3 will be described in detail later.

[0016] The intermediate conveying device 4 inverts the paper that has been printed on one side by the upstream printing device 3 and conveys it to the downstream printing device 5 .

[0017] The downstream printing device 5, while transporting the paper transported from the intermediate transport device 4, prints on a side (back side) of the paper that is different from the side (front side) printed by the upstream printing device 3. Details of the downstream printing device 5 will be described later.

[0018] The paper ejection device 6 ejects the printed paper.

[0019] The print control device 7 transmits print data to the upstream printing device and the downstream printing device. The print control device 7 is configured by a computer equipped with a CPU, ROM, RAM, a hard disk, etc.

[0020] 2, the print control device 7 includes a print data generating unit 11. The print data generating unit 11 is configured by a CPU executing a program stored in a hard disk or the like.

[0021] The print data generator 11 generates print data for each page to be printed on paper by the head unit 23 of the upstream printer 3 and the head unit 43 of the downstream printer 5, which will be described later, and adds timestamp information (corresponding to generation time information) indicating the time when the print data was generated to each print data. As a result, the print data includes the timestamp information and image information in a PDL (Page Description Language) format, as shown in FIG. 3.

[0022] The print data generation unit 11 adds the current time provided by the operating system (OS) in the print control device 7 to the print data as time stamp information. As the time stamp information, for example, 16-byte fixed job generation time related information such as 2022052215342411=2022-05-22 15:34:24:11 can be used.

[0023] Next, the upstream printing apparatus 3 and the downstream printing apparatus 5 will be described in detail.

[0024] As shown in FIG. 2, the upstream printing device 3 includes a control unit 21, an image processing unit 22, a head unit 23 (corresponding to a first printing unit), and an engine unit 24.

[0025] The control unit 21 includes a receiving section 31, an image developing section 32, a time stamp adding section 33, and a temporary storage memory 34. Each section of the control unit 21 can be realized in software or hardware form using a CPU, RAM, ROM, hard disk, etc.

[0026] The receiving unit 31 receives the print data sent by the print data generating unit 11, and separates the print data into image information and time stamp information.

[0027] The image development unit 32 develops the image information separated from the print data into bitmap image data.

[0028] The time stamp adding unit 33 adds the time stamp information separated from the print data to the bitmap image data generated by the image developing unit 32. Here, it is possible to add a small amount of additional information such as the time stamp information to the bitmap image data. The time stamp adding unit 33 adds the time stamp information to the bitmap image data in a form in which it is inserted into the remaining space in the header section of the bitmap image data surrounded by a specified data format.

[0029] Here, time stamp information has features such as no duplication and no return to the origin, compared to information such as page numbers, etc. Also, adding time stamp information to bitmap image data does not affect productivity.

[0030] The temporary storage memory 34 temporarily stores the bitmap image data to which the time stamp information has been added by the time stamp adding unit 33 .

[0031] The image processing unit 22 includes an image processing section 36 and a time stamp extraction section 37 (corresponding to a first acquisition section).

[0032] The image processing unit 36 ​​performs predetermined image processing on the bitmap image data.

[0033] The time stamp extraction unit 37 extracts time stamp information using a determined data format from the bitmap image data that has been image-processed by the image processing unit 36. Here, additional information such as the time stamp information can be processed together with the bitmap image data and extracted immediately before printing.

[0034] The head unit 23 has an inkjet head (not shown). The head unit 23 ejects ink from the inkjet head onto paper to perform printing, based on bitmap image data that has been image-processed by the image processor 36.

[0035] The engine unit 24 controls paper transport in the upstream printing device 3. The engine unit 24 also transmits the timestamp information extracted by the timestamp extraction unit 37 to an engine unit 44 of the downstream printing device 5 (described later). The transmission of the timestamp information from the engine unit 24 to the engine unit 44 can be performed, for example, by CAN (Controller Area Network) communication.

[0036] The downstream side printing device 5 includes a control unit 41, an image processing unit 42, a head unit 43 (corresponding to a second printing unit), and an engine unit 44.

[0037] The control unit 41 includes a receiving section 51, an image developing section 52, a time stamp adding section 53, and a temporary storage memory 54. Each section of the control unit 41 has the same configuration as each section of the control unit 21 of the upstream printing device 3 described above.

[0038] The image processing unit 42 includes an image processing unit 56, a time stamp extraction unit 57 (corresponding to a second acquisition unit), and a comparison and determination unit 58 (corresponding to a determination unit).

[0039] The image processing section 56 and the time stamp extraction section 57 have the same configurations as the image processing section 36 and the time stamp extraction section 37 of the image processing unit 22 of the upstream printing apparatus 3 described above, respectively.

[0040] Comparison and determination unit 58 calculates the time difference between the time indicated by the time stamp information extracted by time stamp extraction unit 37 and the time indicated by the time stamp information extracted by time stamp extraction unit 57 for each sheet of paper printed by head unit 23 of the upstream printing device 3 and head unit 43 of the downstream printing device 5, and determines the consistency between the page printed by head unit 23 and the page printed by head unit 43 based on the calculated time difference. If comparison and determination unit 58 determines that the page printed by head unit 23 and the page printed by head unit 43 on the same sheet of paper are inconsistent, it sends error information to engine unit 44.

[0041] The head unit 43 has the same configuration as the head unit 23 of the above-mentioned upstream printing device 3. The head unit 43 prints on the back side of the paper on which the head unit 23 has printed the front side.

[0042] The engine unit 44 controls paper transport in the downstream printing device 5. The engine unit 44 also receives timestamp information sent by the engine unit 24 of the upstream printing device 3, and outputs this to the comparison and determination unit 58. When the engine unit 44 receives error information from the comparison and determination unit 58, it stops paper transport in the downstream printing device 5 and sends error information to the engine unit 24 of the upstream printing device 3, causing the upstream printing device 3 to stop paper transport.

[0043] Next, the operation of the printing system 1 will be described.

[0044] The print data generation unit 11 of the print control device 7 generates print data for each page to be printed on paper by each of the upstream printing device 3 and the downstream printing device 5, and adds timestamp information indicating the time when the print data was generated to each print data. The print data generation unit 11 then transmits the print data to the upstream printing device 3 and the downstream printing device 5, which each will use for printing.

[0045] In the upstream printing device 3, the receiving unit 31 of the control unit 21 receives the print data transmitted by the print data generating unit 11. The receiving unit 31 separates the received print data into image information and time stamp information, outputs the image information to the image developing unit 32, and outputs the time stamp information to the time stamp adding unit 33.

[0046] The image development unit 32 develops the image information input from the receiving unit 31 into bitmap image data, and outputs this bitmap image data to the time stamp adding unit 33 .

[0047] The time stamp adding unit 33 adds the time stamp information input from the receiving unit 31 to the bitmap image data input from the image developing unit 32 .

[0048] The bitmap image data to which the time stamp information has been added by the time stamp adding section 33 is temporarily stored in a temporary storage memory 34 and then read out to an image processing section 36 of the image processing unit 22 .

[0049] The image processing unit 36 ​​performs a predetermined image processing on the bitmap image data, and outputs the bitmap image data after the image processing to the time stamp extraction unit 37 .

[0050] The time stamp extraction unit 37 extracts time stamp information from the bitmap image data input from the image processing unit 36. In this way, when performing printing based on print data, the time stamp extraction unit 37 obtains the time stamp information of the print data immediately before printing.

[0051] After extracting the time stamp information, the time stamp extraction unit 37 outputs the bitmap image data to the head unit 23. In addition, the time stamp extraction unit 37 outputs the extracted time stamp information to the engine unit 24.

[0052] The engine unit 24 transmits the time stamp information input from the time stamp extraction unit 37 to the engine unit 44 of the downstream printing device 5 .

[0053] In the downstream printing device 5, similarly to the upstream printing device 3, the time stamp adding section 53 in the control unit 41 adds time stamp information to the bitmap image data. After that, the time stamp extracting section 57 in the image processing unit 42 extracts the time stamp information from the bitmap image data.

[0054] After extracting the time stamp information, the time stamp extraction unit 57 outputs the bitmap image data to the head unit 43. In addition, the time stamp extraction unit 57 outputs the extracted time stamp information to the comparison and determination unit 58.

[0055] The engine unit 44 receives the time stamp information sent by the engine unit 24 of the upstream printing device 3 , and outputs it to the comparison and determination unit 58 .

[0056] The comparison and determination unit 58 receives the time stamp information extracted by the time stamp extraction units 37, 57 for each sheet printed by the upstream printing device 3 and the downstream printing device 5 immediately before printing.

[0057] The comparison and determination unit 58 calculates the time difference between the time indicated by the time stamp information extracted by the time stamp extraction unit 37 and the time indicated by the time stamp information extracted by the time stamp extraction unit 57 .

[0058] Next, the comparison and determination unit 58 determines the consistency between the page printed by the upstream printing device 3 and the page printed by the downstream printing device 5 based on the calculated time difference.

[0059] Specifically, the comparison and determination unit 58 determines whether the calculated time difference is less than a predetermined threshold value, which is a preset upper limit value allowed for the difference in generation time between the print data for printing on the front side and the print data for printing on the back side of the same paper.

[0060] If the comparison and determination unit 58 determines that the calculated time difference is less than the threshold value, it determines that the page printed by the upstream printing device 3 and the page printed by the downstream printing device 5 are consistent. In this case, the head units 23, 43 print the matching pages on the front and back of the paper, and the paper is discharged by the paper discharge device 6.

[0061] On the other hand, if it is determined that the calculated time difference is greater than the threshold value, the comparison and determination unit 58 determines that there is a mismatch between the page printed by the upstream printing device 3 and the page printed by the downstream printing device 5. In this case, the comparison and determination unit 58 sends error information to the engine unit 44.

[0062] When the engine unit 44 receives the error information from the comparison and determination unit 58, it stops the transport of paper in the downstream printing device 5 and sends the error information to the engine unit 24 of the upstream printing device 3, causing the upstream printing device 3 to stop transport of paper. This stops the printing operation of the printing system 1. As a result, if pages that do not match each other are being printed on the front and back sides of a sheet of paper, printing is stopped.

[0063] As described above, in printing system 1, comparison and determination unit 58 calculates the time difference between the time indicated by the time stamp information extracted by time stamp extraction unit 37 and the time indicated by the time stamp information extracted by time stamp extraction unit 57 for each sheet of paper printed by head units 23 and 43, and determines the consistency between the page printed by head unit 23 and the page printed by head unit 43 based on the calculated time difference. This makes it possible to stop printing if inconsistent pages are about to be printed on the front and back of a sheet of paper when, for example, printing operation is resumed after maintenance operation has been performed.

[0064] In addition, since the printing system 1 determines the consistency of the front and back printed pages using timestamp information, there is no need to print a mark to determine the consistency of the front and back printed pages, or a sensor to detect the mark.

[0065] Therefore, according to the printing system 1, it is possible to reduce inconsistencies in the printed pages between the front and back sides while suppressing the complexity of the system configuration and without printing additional images.

[0066] The present invention is not limited to the above-described embodiment, and the components can be modified and embodied in the implementation stage without departing from the gist of the invention. In addition, various inventions can be formed by appropriately combining the multiple components disclosed in the above-described embodiment. For example, some components may be deleted from all the components shown in the embodiment.

[0067] [Note] This application discloses the following inventions.

[0068] (Appendix 1) a first printing unit for printing on paper; a second printing unit that prints on the paper printed by the first printing unit; a print data generating unit that generates print data for each page to be printed on paper by each of the first printing unit and the second printing unit, and adds generation time information indicating the time when the print data was generated to each print data; a first acquisition unit that acquires generation time information of the print data when the first printing unit performs printing based on the print data; a second acquisition unit that acquires generation time information of the print data when the second printing unit performs printing based on the print data; a determination unit that calculates, for each sheet of paper printed by the first printing unit and the second printing unit, a time difference between a time indicated by the generated time information acquired by the first acquisition unit and a time indicated by the generated time information acquired by the second acquisition unit, and determines consistency between a page printed by the first printing unit and a page printed by the second printing unit based on the calculated time difference; A printing system comprising: [Explanation of symbols]

[0069] 1 Printing System 2 Paper feeder 3 Upstream printing device 4 Intermediate conveying device 5 Downstream printing device 6 Paper ejection device 7 Printing control device 11 Print data generation unit 21,41 Control unit 22,42 Image Processing Unit 23,43 Head unit 24,44 Engine section 31,51 Receiver 32,52 Image development section 33,53 Time stamp addition section 34,54 Temporary storage memory 36,56 Image processing unit 37,57 Timestamp extraction section 58 Comparison / judgment section

Claims

[Claim 1] a first printing unit for printing on paper; a second printing unit that prints on the paper printed by the first printing unit; a print data generating unit that generates print data for each page to be printed on paper by each of the first printing unit and the second printing unit, and adds generation time information indicating a time when the print data was generated to each print data; a first acquisition unit that acquires generation time information of the print data when the first printing unit performs printing based on the print data; a second acquisition unit that acquires generation time information of the print data when the second printing unit performs printing based on the print data; a determination unit that calculates, for each sheet of paper printed by the first printing unit and the second printing unit, a time difference between a time indicated by the generated time information acquired by the first acquisition unit and a time indicated by the generated time information acquired by the second acquisition unit, and determines consistency between a page printed by the first printing unit and a page printed by the second printing unit based on the calculated time difference; A printing system comprising:

Images