Inkjet printing apparatus, inkjet printing method, and program

Abstract

This invention provides an inkjet printing apparatus, an inkjet printing method, and a program that enable both color measurement and efficient printing. [Solution] The inkjet printing apparatus of the present invention comprises a printing unit for producing printed materials, a first discharge unit for discharging printed materials, and an inline colorimeter for performing color measurement on printed materials that are stopped in the first discharge unit.

Description

Technical Field

[0001] The present invention relates to an inkjet printing apparatus, an inkjet printing method, and a program.

Background Art

[0002] When color measurement is performed on an inkjet printed matter, it is necessary to wait until the ink dries and the color value becomes stable. For example, in the technique described in Patent Document 1, in a printing apparatus provided with a color measuring machine installed in-line on the conveyance path of the printed matter, color measurement is performed after waiting for the elapse of the drying time.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in a printing apparatus in which a color measuring machine is installed on the conveyance path of the printed matter, while waiting for the color value to become stable for color measurement, operations such as the next printing job and maintenance may not be performed, resulting in low printing efficiency.

[0005] The present invention has been made in view of the above situation. The problem to be solved by the present invention is to provide an inkjet printing apparatus, an inkjet printing method, and a program that enable both color measurement and efficient printing.

Means for Solving the Problems

[0006] The above problems according to the present invention are solved by the following means.

[0007] 1. A printing unit that produces a printed matter, A first placement unit on which the printed matter is placed, The system includes an inline colorimeter that performs color measurement on a printed material that has been placed on the first mounting unit after a color measurement waiting time has elapsed for the color of the printed material to stabilize. Inkjet printing device.

[0008] 2. A second mounting section on which the printed material is placed, Furthermore, The inkjet printing apparatus described in paragraph 1.

[0009] 3. The first mounting unit has a tray on which the printed material is placed. The inkjet printing apparatus described in paragraph 1.

[0010] 4. The second mounting section has a tray on which the printed material is placed. The inkjet printing apparatus described in paragraph 2.

[0011] 5. The inline colorimeter performs color measurement on the printed material in a stationary state, which is placed on the first mounting unit. The inkjet printing apparatus described in paragraph 1.

[0012] 6. The inline colorimeter performs color measurement on a portion of the printed material that is placed on the first mounting unit while in a stationary state. The inkjet printing apparatus described in paragraph 1.

[0013] 7. The inline colorimeter is, After performing color measurement on a portion of the stopped printed material, the stopped printed material is transported in the paper transport direction. The inkjet printing apparatus described in item 6.

[0014] 8. The inline colorimeter performs color measurement while scanning in a direction perpendicular to the paper transport direction. The inkjet printing apparatus described in paragraph 1.

[0015] 9. The printed material to be measured is placed on the first mounting section. The inkjet printing apparatus according to claim 1.

[0016] 10. A printed matter that is not an object of colorimetry is placed on the second placement unit. The inkjet printing apparatus according to claim 2.

[0017] 11. Further comprising an output unit that outputs information regarding the color of the printed matter. The inkjet printing apparatus according to claim 1.

[0018] 12. The output unit outputs information regarding fluctuations in the color of the printed matter. The inkjet printing apparatus according to claim 11.

[0019] 13. The colorimetry standby time is adjusted according to at least one of the paper type and paper thickness of the printed matter. The inkjet printing apparatus according to claim 1.

[0020] 14. The colorimetry standby time is adjusted according to at least one of the type of ink, image density, and ink amount in the printed matter. The inkjet printing apparatus according to claim 1.

[0021] 15. The colorimetry standby time is adjusted according to at least one of the paper surface temperature during printing of the printed matter, the temperature of the first placement unit, and the humidity of the first placement unit. The inkjet printing apparatus according to claim 1.

[0022] 16. When performing a normal job that is not an object of colorimetry during execution of a colorimetry job for creating a printed matter to be subjected to colorimetry, when the color variation of the printed matter exceeds the allowable value, the normal job is temporarily stopped, and information regarding the printed matter produced between the colorimetry job and the temporary stop is notified. The inkjet printing apparatus according to claim 12.

[0023] 17. The printing process in which printed materials are produced, The process includes a color measurement step in which color measurement is performed on a printed material that has been placed on a first mounting section after a color measurement waiting time has elapsed for the color of the printed material to stabilize. Inkjet printing method.

[0024] 18. A program for causing the computer in an inkjet recording apparatus, which comprises a printing unit for producing printed material, a first placement unit on which the printed material is placed, an inline colorimeter, and a computer, to function as a control unit, The control unit causes the inline colorimeter to perform color measurement on the printed material that has been placed on the first placement unit, after the color measurement waiting time for the printed material's color to stabilize has elapsed. program. [Effects of the Invention]

[0025] According to the present invention, an inkjet printing apparatus, an inkjet printing method, and a program can be provided that enable both color measurement and efficient printing. [Brief explanation of the drawing]

[0026] [Figure 1] This is a schematic diagram of one embodiment of an inkjet printing apparatus. [Figure 2] This is a block diagram showing the functional configuration of one embodiment of an inkjet printing apparatus. [Figure 3] This is a flowchart illustrating an example of the colorimetric process. [Figure 4] This is a flowchart illustrating an example of the colorimetric process. [Modes for carrying out the invention]

[0027] The following description illustrates one or more embodiments of the present invention with reference to the drawings. The effects and features of the embodiments of the present invention will be understood from the following detailed description and drawings. The following detailed description and drawings are provided for illustrative purposes only and do not limit the scope of the present invention.

[0028] Figure 1 is a schematic diagram of one embodiment of the inkjet printing apparatus 1. Figure 2 is a block diagram showing the functional configuration of one embodiment of the inkjet printing apparatus 1. The inkjet printing apparatus 1 of the present invention comprises a printing unit 5, a first discharge unit 8, and an inline colorimeter 9. As shown in Figure 1, the inkjet printing apparatus 1 may also comprise a control unit 2, a paper feeding unit 3, a transport unit 4, an image scanning unit 6, and a second discharge unit 12. In addition, as shown in Figure 2, the inkjet printing apparatus 1 may also comprise a cleaning unit 7, a temperature and humidity measuring unit 10, a color measurement information notification unit 11, a storage unit 13, and a bus 14.

[0029] The paper feeding unit 3 stores the recording medium M. The paper feeding unit 3 has, for example, a tray. Various media capable of fixing ink that has landed on a sheet-like main surface can be used as the recording medium M. Examples of recording medium M include paper, cloth, sheet-like resin, etc. Examples of paper include plain paper, coated paper, etc. Sheet paper is preferred for the recording medium M.

[0030] As shown in Figure 1, the transport unit 4 includes, for example, a feeder board 41, a first transfer drum 42, a transport drum 43, a second transfer drum 44, and an unloading unit 45.

[0031] The feeder board 41 transports the recording medium M from the paper feeding unit 3 to the first transfer drum 42. The first transfer drum 42 holds one end of the recording medium M transported by the feeder board 41, picks it up, and transfers it to the transport drum 43.

[0032] The transport drum 43 is cylindrical. The side surface of the transport drum 43 serves as a transport surface that attracts and holds the recording medium M. With the recording medium M held on the transport surface, the transport drum 43 rotates in one direction around its central axis as the axis of rotation. As a result, the transport drum 43 transports the recording medium M, which is attracted and held on the transport surface, along the transport surface.

[0033] The printing unit 5 has, for example, one or more head units 51. The printing unit 5 performs a printing process to produce a printed material P using an inkjet method. Each head unit 51 has one or more inkjet heads. The head unit 51 has an ink ejection surface at a position facing the transport surface of the transport drum 43. The head unit 51 ejects ink onto the recording medium M held in the transport drum 43 at an appropriate timing corresponding to the rotation of the transport drum 43 to form an image and produce a printed material P. In the inkjet printing apparatus 1 illustrated in Figure 1, four head units 51 are arranged at predetermined intervals from the upstream side in the rotational direction of the transport drum 43. The four head units 51 correspond to, for example, four colors of ink: yellow, magenta, cyan, and black.

[0034] In the printing section 5, regular jobs, color measurement jobs, etc., are performed. A regular job is a printing job that produces a normal printed material P that is not subject to color measurement. A color measurement job is a printing job that produces a printed material P that is subject to color measurement. The image formed in a color measurement job may be a color chart, or it may be the same image as the image formed in a regular job. If the purpose of color measurement is image quality adjustment, the image formed in a color measurement job may be, for example, a color chart. If the purpose of color measurement is quality confirmation, the image formed in a color measurement job may be, for example, the same image as the image formed in a regular job.

[0035] The image scanning unit 6 irradiates light onto the printed material P from a light source and reads the reflected image. The image scanning unit 6 is composed of, for example, an inline sensor in which multiple detection elements are arranged along a direction (width direction) perpendicular to the transport direction of the recording medium M. The image data read by the image scanning unit 6 is sent to, for example, the control unit 2.

[0036] The cleaning unit 7 performs maintenance by cleaning the head unit 51. The cleaning unit 7 is installed adjacent to the transport drum 43, for example, in the direction in which the rotation axis of the transport drum 43 extends. In this case, the cleaning unit 7 cleans the head unit 51 as it moves from a position opposite the transport drum 43. Examples of cleaning include wiping to remove ink adhering to the ink ejection surface and purging to eject ink from the ink flow path.

[0037] The second transfer drum 44 holds one end of the printed material P that has been transported by the transport drum 43, picks it up, and hands it over to the discharge unit 45.

[0038] The discharge section 45 is the discharge path for the printed material P, and it discharges the printed material P to discharge sections such as the first discharge section 8 and the second discharge section 12. The discharge section 45 is composed of, for example, a belt, rollers, etc. If there are multiple discharge sections, for example, if the inkjet printing device 1 has a second discharge section 12 in addition to the first discharge section 8, the discharge path in the discharge section 45 may branch along the way as shown in Figure 1.

[0039] The printed material P is discharged into the first discharge unit 8. The first discharge unit 8 has, for example, a tray. The inline colorimeter 9 is located, for example, above the first discharge unit 8. The inline colorimeter 9 performs a color measurement process. Specifically, the inline colorimeter 9 performs color measurement on the printed material P, which is in a stopped state in the first discharge unit 8, based on control by the control unit 2. Color measurement is the measurement of color information, for example, the measurement of color values ​​such as L*a*b* values. As the inline colorimeter 9, for example, a spectrophotometer that spectrally measures the color by spectroscopy of reflected light from the printed material P can be used.

[0040] In conventional printing apparatuses where the colorimeter is installed on the transport path of the printed material, it was sometimes impossible to perform the next print job, maintenance, or other tasks while waiting for the color values ​​to stabilize for color measurement, resulting in low printing efficiency. In contrast, in the inkjet printing apparatus 1 of the present invention, color measurement is performed in the first discharge unit 8. As a result, in the inkjet printing apparatus 1 of the present invention, it is easy to perform the next print job, maintenance, or other tasks while waiting for color measurement and / or even while color measurement is being performed. Therefore, the inkjet printing apparatus 1 of the present invention makes it possible to achieve both color measurement and efficient printing. Furthermore, because the colorimeter is an in-line colorimeter 9 equipped in the inkjet printing apparatus 1, rather than a colorimeter installed outside the inkjet printing apparatus 1, it is easier to control the printing process and the color measurement process. In addition, performing color measurement on a stationary printed material P results in higher accuracy of color measurement compared to when color measurement is performed on a moving printed material P.

[0041] The "color measurement of a stationary printed material P" according to the present invention also includes color measurement by repeatedly measuring the color of a part of the stationary printed material P and moving the printed material P. For example, first, the inline colorimeter 9 scans in a direction perpendicular to the transport direction of the printed material P and performs color measurement on the first row of the stationary printed material P. The row of the printed material P at this time is, for example, the range that the inline colorimeter 9 can measure in a single scan. Once the color measurement of the first row of the printed material P is completed, the printed material P moves one row within the first discharge unit 8. Next, the inline colorimeter 9 scans again in a direction perpendicular to the transport direction of the printed material P and performs color measurement on the second row adjacent to the first row of the stationary printed material P. Once the color measurement of the second row of the printed material P is completed, the printed material P moves one row again within the first discharge unit 8. Thus, the color measurement according to the present invention does not need to be performed in a single step on a stationary printed material P, but may be performed while the printed material P is repeatedly stopped and moved.

[0042] The color value of the printed material P discharged to the first discharge unit 8 is due to reasons such as the ink not yet being dry. Therefore, it may not stabilize immediately. For this reason, color measurement is performed when the printed material P reaches the first discharge unit 8. The measurement may be performed after a predetermined waiting time has elapsed following discharge.

[0043] The color measurement waiting time may be adjusted according to at least one of the paper type and paper thickness of the printed material P. The color measurement waiting time may also be adjusted according to at least one of the ink type, image density, and ink amount of the printed material P. The ink amount may be the total ink amount of the printed material P, or the maximum ink amount per unit area of ​​the printed material P. The color measurement waiting time may also be adjusted according to at least one of the paper surface temperature of the printed material P during printing, the temperature of the first discharge unit 8, and the humidity of the first discharge unit 8. The adjustment of the color measurement waiting time may be performed by the user or based on control by the control unit 2.

[0044] The temperature and humidity measuring unit 10 is located near the first discharge unit 8 and measures the temperature and / or humidity of the first discharge unit 8. The temperature and / or humidity of the first discharge unit 8 measured by the temperature and humidity measuring unit 10 is used, for example, to adjust the color measurement waiting time.

[0045] The color measurement information notification unit 11 notifies the system of the color measurement information obtained by the inline colorimeter 9, for example, by displaying it on a screen. The color measurement information notified by the color measurement information notification unit 11 is, for example, information such as whether or not the variation in the color value of the printed material P exceeds an acceptable value.

[0046] Printed material P is discharged to the second discharge unit 12. The second discharge unit 12 is a discharge unit provided separately from the first discharge unit 8. The second discharge unit 12 has, for example, a tray. If the inkjet printing apparatus 1 is further equipped with a second discharge unit 12 in addition to the first discharge unit 8, for example, only printed material P that is subject to color measurement is discharged to the first discharge unit 8, and ordinary printed material P that is not subject to color measurement is discharged to the second discharge unit 12.

[0047] The control unit 2 controls the operation of other functional components according to print image data, print settings, etc. The control unit 2 is a computer and includes, for example, a CPU (Central Processing Unit), RAM (Random Access Memory), and ROM (Read Only Memory). The CPU executes various control programs to drive and control the inkjet printer 1 and performs various calculations. The RAM provides the CPU with a working memory space and stores temporary data. The RAM may also include non-volatile memory. The ROM stores various control programs executed by the CPU, setting data, etc. Instead of ROM, rewritable non-volatile memory such as flash memory may be used.

[0048] The memory unit 13 stores programs executed by the CPU, various configuration data, etc. For example, an HDD (Hard Disk Drive) may be used as the memory unit 13, and DRAM (Dynamic Random Access Memory) may be used in combination.

[0049] Bus 14 is a path for sending and receiving signals between the control unit 2 and other functional configurations. Each functional configuration may operate based on control signals sent from the control unit 2 and a separate processor.

[0050] Next, using Figures 3 and 4, an example of the color measurement process flow in the inkjet printing apparatus 1 of the present invention will be explained.

[0051] Figure 3 is a flowchart in an embodiment in which, when a regular job is scheduled after a color measurement job, it is determined whether or not to perform the regular job during the color measurement waiting period and / or during the color measurement, depending on the purpose of the color measurement.

[0052] (Step S11) In step S11, the printing unit 5 performs a color measurement job. As described above, the image formed on the printed material P in the color measurement job is, for example, a color chart if the purpose of the color measurement is image quality adjustment, and the same image as the image formed in a normal job if the purpose of the color measurement is quality confirmation.

[0053] (Step S12) After the color measurement job is performed in step S11, the flow proceeds to step S12. In step S12, the control unit 2 determines whether or not a regular job is reserved.

[0054] (Step S13) If it is determined in step S12 that a regular job is already booked, the flow proceeds to step S13. In step S13, the control unit 2 determines whether the purpose of the color measurement is for image quality adjustment.

[0055] (Step S14) If it is not determined in step S13 that the purpose of the color measurement is for image quality adjustment, the flow proceeds to step S14. In step S14, the control unit 2 determines whether or not the purpose of the color measurement is for quality confirmation.

[0056] (Step S15) If it is determined in step S14 that the purpose of color measurement is for quality confirmation, the flow proceeds to step S15. In step S15, the inline colorimeter 9 performs color measurement standby and color measurement, while the printing unit 5 performs a normal job in parallel with this color measurement standby and color measurement. In other words, in step S15, a normal job is performed during color measurement standby and / or color measurement. The printed material P produced by the normal job may be one or more.

[0057] When multiple printed materials P are produced in a normal job, these materials P may be produced sequentially. If the color measurement results show that the variation in color values ​​exceeds an acceptable limit, the printing unit 5 may temporarily suspend the normal job under the control of the control unit 2. The variation in color values ​​refers to, for example, the difference between the set value and the measured value of the color value. At this time, the color measurement information notification unit 11 may, under the control of the control unit 2, notify that printed materials P produced between the color measurement job and the temporary suspension of the normal job are papers that do not meet print quality standards. This makes it easy to identify printed materials P that are highly likely to have color value variations exceeding an acceptable limit, even while a normal job is running during color measurement waiting and / or color measurement.

[0058] (Step S16) If it is not determined in step S12 that a regular job is scheduled, if it is determined in step S13 that the purpose of color measurement is for image quality adjustment, or if it is not determined in step S14 that the purpose of color measurement is for quality confirmation, the flow proceeds to step S16. In step S16, the inline colorimeter 9 performs color measurement standby and color measurement, but no regular jobs are performed by the printing unit 5 in parallel with this color measurement standby and color measurement. In other words, no regular jobs are performed in step S16 while color measurement standby and / or color measurement is being performed.

[0059] The color measurement process ends when color measurement is performed in step S15 or step S16. After the color measurement process ends, a normal job may be performed, and the color measurement process may be performed again as needed after or during the normal job.

[0060] The inkjet printing apparatus 1 of the above embodiment can perform normal jobs while waiting for color measurement and / or even while color measurement is being performed, thereby enabling both color measurement and efficient printing.

[0061] Figure 4 is a flowchart of an embodiment in which periodic maintenance is performed while waiting for color measurement and / or during color measurement, if the time until periodic maintenance that does not affect the color values ​​of printed material P is below a threshold.

[0062] (Step S21) In step S21, a color measurement job is performed by the printing unit 5 to create a printed material P to be measured, similar to step S11.

[0063] (Step S22) After the color measurement job is performed in step S21, the flow proceeds to step S22. In step S22, the control unit 2 determines whether the time until the scheduled maintenance is below a threshold. The interval and threshold for scheduled maintenance are, for example, predetermined values ​​set by the user.

[0064] (Step S23) If it is determined in step S22 that the time until the scheduled maintenance is less than the threshold, the flow proceeds to step S23. In step S23, the control unit 2 determines whether or not the scheduled maintenance will affect the color value. Scheduled maintenance that does not affect the color value includes, for example, wiping to remove ink adhering to the ink ejection surface, purging to eject ink from the ink flow path, and adjusting the transport unit 4.

[0065] (Step S24) If it is determined in step S23 that the scheduled maintenance will not affect the color values, the flow proceeds to step S24. In step S24, the inline colorimeter 9 performs color measurement standby and color measurement, while the scheduled maintenance is performed in parallel with this color measurement standby and color measurement. In other words, in step S24, the scheduled maintenance is performed during color measurement standby and / or color measurement.

[0066] (Step S25) If it is determined in step S22 that the time until the scheduled maintenance is not below the threshold, or if it is determined in step S23 that the scheduled maintenance will not affect the color values, the flow proceeds to step S25. In step S25, the inline colorimeter 9 performs color measurement standby and color measurement, but scheduled maintenance is not performed in parallel with this color measurement standby and color measurement. In other words, in step S25, scheduled maintenance is not performed during color measurement standby and / or color measurement.

[0067] The color measurement process ends when color measurement is performed in step S24 or step S25. After the color measurement process ends, a normal job may be performed, and the color measurement process may be performed again as needed after or during the normal job.

[0068] The inkjet printing apparatus 1 of the above embodiment can be maintained while waiting for color measurement and / or even while color measurement is being performed, thereby enabling both color measurement and efficient printing.

[0069] The inkjet printing method of the present invention comprises a printing step in which a printed material P is produced, and a color measurement step in which color measurement is performed on the printed material P, which is in a stopped state at the first discharge unit 8 where the printed material P is discharged.

[0070] The program of the present invention is a program that causes the computer in the inkjet printing apparatus 1 described above to function as a control unit 2. The computer, functioning as a control unit 2 through this program, controls the inkjet printing apparatus 1 as described above.

[0071] The above description and drawings are for illustrative purposes only regarding embodiments of the present invention and are not intended to limit the scope of the invention. The scope of the invention should be interpreted as described in the claims. [Explanation of Symbols]

[0072] 1. Inkjet printing device 2 Control Unit 3 Paper feed section 4. Conveying section 41 Feeder board 42. First handover drum 43 Conveyor Drum 44. Second handover drum 45 Loading section 5 Printing Department 51 Head Unit 6. Image scanning unit 7. Cleaning Department 8 1st discharge section 9. Inline colorimeter 10 Temperature and humidity measuring section 11 Colorimetric information notification section 12 Second discharge section 13 Storage section 14 bus M recording medium P Printed matter

Claims

1. The printing department, which produces printed materials, A first mounting section on which the printed material is placed, The system includes an inline colorimeter that performs color measurement on a printed material that has been placed on the first mounting unit after a color measurement waiting time has elapsed for the color of the printed material to stabilize. Inkjet printing device.

2. A second mounting section on which the aforementioned printed material is placed, The inkjet printing apparatus according to claim 1, further comprising:

3. The inkjet printing apparatus according to claim 1, wherein the first mounting section has a tray on which the printed material is mounted.

4. The inkjet printing apparatus according to claim 2, wherein the second mounting section has a tray on which the printed material is placed.

5. The inkjet printing apparatus according to claim 1, wherein the inline colorimeter performs color measurement on the stopped printed material placed on the first mounting section.

6. The inkjet printing apparatus according to claim 1, wherein the inline colorimeter performs color measurement on a portion of the printed material that is placed on the first mounting section and is in a stationary state.

7. The aforementioned inline colorimeter is The inkjet printing apparatus according to claim 6, wherein after performing color measurement on a portion of the stopped printed material, the stopped printed material is transported in the paper transport direction.

8. The inkjet printing apparatus according to claim 1, wherein the inline colorimeter performs color measurement while scanning in a direction perpendicular to the paper transport direction.

9. The inkjet printing apparatus according to claim 1, wherein the printed material to be measured is placed on the first placement section.

10. The inkjet printing apparatus according to claim 2, wherein a printed material that is not subject to color measurement is placed on the second placement section.

11. The system further comprises an output unit that outputs information regarding the color of the printed material, The inkjet printing apparatus according to claim 1.

12. The inkjet printing apparatus according to claim 11, wherein the output unit outputs information relating to color variations of the printed material.

13. The color measurement waiting time is adjusted according to at least one of the paper type and paper thickness in the printed material. The inkjet printing apparatus according to claim 1.

14. The color measurement waiting time is adjusted according to at least one of the ink type, image density, and ink amount in the printed material. The inkjet printing apparatus according to claim 1.

15. The color measurement waiting time is adjusted according to at least one of the following: the paper surface temperature of the printed material during printing, the temperature of the first mounting unit, and the humidity of the first mounting unit. The inkjet printing apparatus according to claim 1.

16. When a color measurement job is running to create printed materials that will be measured for color, and a regular job that does not require color measurement is being executed at the same time, If the color variation of the printed material exceeds an acceptable limit, the normal job is temporarily suspended, and information regarding the printed material produced between the color measurement job and the suspension is notified. The inkjet printing apparatus according to claim 12.

17. The printing process in which printed materials are produced, The process includes a color measurement step in which a color measurement is performed on a printed material that has been placed on a first mounting section after a color measurement waiting time has elapsed for the color of the printed material to stabilize. Inkjet printing method.

18. A program for causing the computer in an inkjet recording apparatus, which comprises a printing unit for producing printed materials, a first placement unit on which the printed materials are placed, an inline colorimeter, and a computer, to function as a control unit, The control unit causes the inline colorimeter to perform color measurement on the printed material that has been placed on the first placement unit, after the color measurement waiting time for the printed material's color to stabilize has elapsed. program.

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