Image forming apparatus, image forming system, image forming method, and program

Abstract

To provide an image formation apparatus, an image formation system, an image formation method and a program that can eliminate the deviation of an impact position of ink due to the variation in the mounting of multiple carriages installed side-by-side in the sub-scanning direction.SOLUTION: An image formation apparatus having a plurality of carriages mounted with a liquid discharge head includes: an acquisition unit which acquires divided printing data in a case where a data portion in the size expanded in the direction corresponding to the conveyance direction from a data portion in printing data corresponding to the length of nozzle arrays arranged side by side in the conveyance direction is divided as the divided printing data; a specification unit which specifies the data portion of the length of the nozzle array deviating by pixels corresponding to the deviation from a target position of an installation position of the carriage as the data portion of the printing object in the divided printing data; a discharge control unit that performs discharge control of the liquid discharge head using the data portion of the printing object; and a movement control unit that controls movement of the carriage on the basis of the data portion of the printing object.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to an image forming apparatus, an image forming system, an image forming method, and a program. [Background Art]

[0002] A printed image formed by an inkjet printer, which is an image forming apparatus, is composed of a large number of dot rows formed by ejecting ink from nozzle rows. For this reason, if the dot formation position, which is the landing position of ink on a print medium, is deviated from a predetermined target position, a clear printed image cannot be drawn on a recording medium such as paper. In particular, in the case of an inkjet printer in which a plurality of carriages each mounted with a liquid ejection head are arranged in the sub-scanning direction, if each carriage is not accurately arranged at a designed position, the formation positions of dot rows between the carriages will not be aligned. When one printed image is formed using all these carriages, a clear printed image cannot be obtained. Therefore, when installing such carriages in an inkjet printer, it is necessary to adjust and attach the carriages to the designed positions while paying close attention. However, even when a jig or the like is used, although the mounting accuracy can be kept within a certain range, the variation in accuracy cannot be reduced to zero.

[0003] On the other hand, when adjusting the dot formation position in the sub-scanning direction in a conventional inkjet printer, the adjustment of the dot formation position can be achieved by adjusting the conveying distance of the recording medium. However, in the case of an inkjet printer that performs printing with a configuration in which a plurality of carriages are arranged side by side in the sub-scanning direction, since the conveyance mechanism is the same, the method of adjusting the conveying distance of the recording medium reflects the adjustment result on the dot formation positions resulting from ink ejection from all carriages. Therefore, the dot formation position resulting from ink ejection from a carriage that does not require adjustment is also affected by the adjustment, resulting in deviation of the landing position. For this reason, there is a problem that the adjustment of the dot formation position by adjusting the conveying distance of the recording medium cannot be performed.

[0004] In order to provide an image forming apparatus and a white correction method that can easily suppress reading unevenness in the scanning direction, a configuration is disclosed in which an image sensor is attached to a media-width inkjet head unit, and the voltage applied to the liquid ejection head is adjusted based on the imaging results from the image sensor (see, for example, Patent Document 1). [Overview of the project] [Problems that the invention aims to solve]

[0005] However, in the technology described in Patent Document 1, in an inkjet printer that performs printing in a serial manner by arranging multiple independently driven carriages in the sub-scanning direction, if a misalignment of the ink landing position occurs in the sub-scanning direction, adjusting the voltage applied to the liquid ejection head allows for adjustment in the main scanning direction, which is the carriage scanning direction, but not in the sub-scanning direction, which is the transport direction of the recording medium. Therefore, there is a problem in that the misalignment of the ink landing position in the sub-scanning direction cannot be eliminated.

[0006] The present invention has been made in view of the above, and aims to provide an image forming apparatus, an image forming system, an image forming method, and a program that can eliminate the misalignment of ink placement caused by variations in the mounting of multiple carriages arranged in a sub-scanning direction. [Means for solving the problem]

[0007] To solve the above-mentioned problems and achieve the objective, the present invention provides a serial image forming apparatus comprising a plurality of carriages, each equipped with one or more liquid ejection heads, comprising: an acquisition unit that acquires divided print data when the print data is divided into divided print data, the data portion of which is extended in the direction corresponding to the transport direction from the data portion of the print data corresponding to the length of the nozzle row in the transport direction of the recording medium in the liquid ejection head; an identification unit that identifies the data portion of the nozzle row in the divided print data acquired by the acquisition unit, which is shifted by a pixel amount corresponding to the deviation of the carriage's installation position from the target position in the transport direction, as the data portion of the print target to be used for ejecting ink from the liquid ejection head; an ejection control unit that controls the ejection of ink from the liquid ejection head to the recording medium using the data portion of the print target identified by the identification unit; and a movement control unit that controls the movement of the carriage in the main scanning direction based on the data portion of the print target identified by the identification unit. [Effects of the Invention]

[0008] According to the present invention, it is possible to eliminate the misalignment of ink placement caused by variations in the mounting of multiple carriages arranged in a sub-scanning direction. [Brief explanation of the drawing]

[0009] [Figure 1] Figure 1 is a diagram showing an example of the main components of the image forming apparatus of the image forming system according to the embodiment. [Figure 2] Figure 2 shows an example of the hardware configuration of an image forming apparatus according to an embodiment. [Figure 3] Figure 3 shows an example of the hardware configuration of a PC according to this embodiment. [Figure 4] Figure 4 shows an example of the configuration of a functional block in the image forming system according to the embodiment. [Figure 5]Figure 5 illustrates the operation when there is no misalignment in the ink landing position in the sub-scanning direction of the liquid ejection head. [Figure 6] Figure 6 illustrates the operation when there is a discrepancy in the ink landing position in the sub-scanning direction of the liquid ejection head. [Figure 7] Figure 7 is a flowchart showing an example of the overall operation flow of the image forming system according to the embodiment. [Modes for carrying out the invention]

[0010] Embodiments of the image forming apparatus, image forming system, image forming method, and program according to the present invention will be described in detail below with reference to the drawings. Furthermore, the present invention is not limited by the following embodiments, and the components in the following embodiments include those that are easily conceivable by those skilled in the art, substantially identical, and so-called equivalents. Moreover, various omissions, substitutions, modifications, and combinations of components can be made without departing from the spirit of the following embodiments.

[0011] Furthermore, computer software refers to programs related to the operation of a computer, and other information used for computer processing that is similar to a program (hereinafter, computer software is referred to as "software"). Application software is a general term for software used to perform specific tasks, within the classification of software. On the other hand, an operating system (OS) is software that controls the computer and enables application software and other programs to utilize computer resources. The operating system performs basic management and control of the computer, such as input / output control, management of hardware such as memory and hard disks, and process management. Application software operates by utilizing the functions provided by the operating system. A program is a set of instructions for a computer, combined to produce a specific result. Furthermore, something similar to a program refers to something that is not a direct instruction to the computer and therefore cannot be called a program, but has similar properties to a program in that it defines the processing of the computer. For example, a data structure (the logical structure of data, represented by the interrelationships between data elements) falls under the category of something similar to a program.

[0012] (Key components of the image forming apparatus in an image forming system) Figure 1 is a diagram showing an example of the main components of the image forming apparatus of the image forming system according to this embodiment. The main components of the image forming system 1 according to this embodiment will be described with reference to Figure 1.

[0013] As shown in Figure 1, the image forming system 1 includes an image forming apparatus 10 and a PC (Personal Computer) 20.

[0014] The image forming apparatus 10 is a serial-type image forming apparatus equipped with multiple carriages, and ink is ejected by liquid ejection heads provided on each carriage to form an image on a recording medium such as paper. As shown in Figure 1, the image forming apparatus 10 includes carriage 15U and carriage 15D.

[0015] The carriage 15U is a component that changes the landing position of the ink ejected from the liquid ejection head 16U by reciprocating in the main scanning direction indicated by arrow A1, which is perpendicular to arrow B, which indicates the transport direction (sub-scanning direction) of the recording medium P. The carriage 15U is equipped with one or more liquid ejection heads 16U. The carriage 15U is installed upstream of the carriage 15D in the sub-scanning direction.

[0016] As will be described later, the liquid ejection head 16U has a nozzle row formed in which multiple nozzles from which ink is ejected are arranged in the sub-scanning direction.

[0017] The carriage 15D is a component that changes the landing position of the ink ejected from the liquid ejection head 16D by reciprocating in the main scanning direction indicated by arrow A2, which is perpendicular to arrow B, which indicates the transport direction (sub-scanning direction) of the recording medium P. The carriage 15D is equipped with one or more liquid ejection heads 16D. The carriage 15D is installed upstream of the carriage 15D in the sub-scanning direction.

[0018] Furthermore, the type of ink ejected by the liquid ejection head 16U of carriage 15U and the type of ink ejected by the liquid ejection head 16D of carriage 15D may be different. For example, carriage 15U may form an image using inks such as C (cyan), M (magenta), Y (yellow), and K (black), while carriage 15D may form an image using special color inks such as white ink, metallic colors, and fluorescent colors. Alternatively, one of the liquid ejection heads 16U and 16D may eject achromatic ink and the other ejects chromatic ink.

[0019] Furthermore, although the image forming system 1 shown in Figure 1 is assumed to have two carriages, carriage 15U and carriage 15D, it is not limited to this and may have three or more carriages.

[0020] PC20 is an information processing apparatus that transmits print data to be printed to the image forming apparatus 10. In the present embodiment, PC20 divides the print data into data respectively corresponding to the liquid discharge head 16U of the carriage 15U and the liquid discharge head 16D of the carriage 15D, and then transmits the divided data to the image forming apparatus 10. Here, the data obtained by dividing the print data by the image forming apparatus 10 may be referred to as "divided print data".

[0021] Note that PC20 is not limited to being a personal computer as the information processing apparatus that transmits print data to the image forming apparatus 10, and may be an information processing apparatus such as a smartphone, a tablet terminal, or a workstation.

[0022] (Hardware Configuration of Image Forming Apparatus) Figure 2 is a diagram illustrating an example of the hardware configuration of the image forming apparatus according to the embodiment. The hardware configuration of the image forming apparatus 10 according to the embodiment will be described with reference to Figure 2.

[0023] As shown in Figure 2, the image forming apparatus 10 includes a control unit 100, an operation panel 120, a sensor 130, a head driver 140U, a head driver 140D, a main scanning motor 17U, a main scanning motor 17D, a sub-scanning motor 150, and a conveyance roller 160.

[0024] The control unit 100 includes a CPU (Central Processing Unit) 101, a ROM (Read Only Memory) 102, a RAM (Random Access Memory) 103, an NVRAM (Non-Volatile RAM) 104, an ASIC (Application Specific Integrated Circuit) 105, a print control unit 106U, a print control unit 106D, a main scanning motor driving unit 107U, a main scanning motor driving unit 107D, an I / O 108, a communication I / F 109, and a sub-scanning motor driving unit 110.

[0025] The CPU 101 is an arithmetic unit that controls the entire image forming apparatus 10. The ROM 102 is a non-volatile memory device that stores fixed data such as programs executed by the CPU 101. The RAM 103 is a volatile memory device that serves as the work area for arithmetic processing by the CPU 101. The RAM 103 also temporarily stores image data and other data.

[0026] The NVRAM 104 is a non-volatile memory device that retains data and programs even when the power supply to the image forming apparatus 10 is cut off.

[0027] ASIC105 is an integrated circuit that processes various signal processing and sorting operations on image data, as well as input / output signals for controlling the entire image forming apparatus 10.

[0028] The print control unit 106U is a control circuit that controls the ejection operation of the liquid ejection head 16U via the head driver 140U according to the control of the CPU 101. The print control unit 106U transfers data for driving the liquid ejection head 16U to the head driver 140U. For example, the print control unit 106U transfers image data as serial data and outputs the transfer clock, latch signal, control signal, etc. required for the transfer of image data to the head driver 140U. Based on the image data corresponding to one line of the liquid ejection head 16U input serially, the head driver 140U selectively supplies drive pulses that constitute the drive waveform received from the print control unit 106U to the pressure generating means of the liquid ejection head 16U, thereby driving the liquid ejection head 16U and ejecting ink. The image data is based on the divided print data divided by the PC 20 described above, but the details will be described later.

[0029] The print control unit 106D is a control circuit that controls the ejection operation of the liquid ejection head 16D via the head driver 140D according to the control of the CPU 101. The print control unit 106D transfers data for driving the liquid ejection head 16D to the head driver 140D. For example, the print control unit 106D transfers image data as serial data and outputs the transfer clock, latch signal, control signal, etc. required for the transfer of image data to the head driver 140D. Based on the image data corresponding to one line of the liquid ejection head 16D input serially, the head driver 140D selectively supplies drive pulses that constitute the drive waveform received from the print control unit 106D to the pressure generating means of the liquid ejection head 16U, thereby driving the liquid ejection head 16U to eject ink. The image data is based on the divided print data divided by the PC 20 described above, but the details will be described later.

[0030] The main scanning motor drive unit 107U is a drive circuit that controls the operation of the main scanning motor 17U according to the control of the CPU 101. The main scanning motor 17U is a motor device that moves the carriage 15U in the main scanning direction according to the control of the main scanning motor drive unit 107U.

[0031] The main scanning motor drive unit 107D is a drive circuit that controls the operation of the main scanning motor 17D according to the control of the CPU 101. The main scanning motor 17D is a motor device that moves the carriage 15D in the main scanning direction according to the control of the main scanning motor drive unit 107D.

[0032] I / O 108 is an interface circuit for acquiring information from the sensor 130 and extracting information used for controlling each part of the image forming apparatus 10. The sensor 130 is, for example, an optical sensor for reading a printed image formed on the recording medium P, and a temperature sensor for detecting the temperature of a heater during printing.

[0033] The communication interface 109 is an interface circuit that transmits and receives data and signals to and from the PC 20. Specifically, the communication interface 109 transmits and receives data and signals from the PC 20 via cable or network. When the communication interface 109 communicates with the PC 20 via a network, it should, for example, comply with TCP (Transmission Control Protocol) / IP (Internet Protocol). The print data (split print data) stored in the receive buffer of the communication interface 109 is analyzed by the CPU 101, image processing and data rearrangement processing are performed by the ASIC 105, and the data is then transferred as ejection data to the head driver 140U and head driver 140D by the print control unit 106U and print control unit 106D, respectively.

[0034] The sub-scanning motor drive unit 110 is a drive circuit that controls the operation of the sub-scanning motor 150 according to the control of the CPU 101. The sub-scanning motor 150 is a motor device that rotates the transport roller 160 to transport the recording medium P in the sub-scanning direction according to the control of the sub-scanning motor drive unit 110. The transport roller 160 is a roller member that rotates due to the rotational drive of the sub-scanning motor 150 and transports the recording medium P along the transport path in the sub-scanning direction.

[0035] The control panel 120 is a device such as a touch panel for inputting and outputting various types of information.

[0036] Note that the hardware configuration of the image forming apparatus 10 shown in Figure 2 is an example, and it is not necessary to include all of the components shown in Figure 2, or other components may be included.

[0037] (PC hardware configuration) Figure 3 is a diagram showing an example of the hardware configuration of a PC according to this embodiment. The hardware configuration of PC20 according to this embodiment will be described with reference to Figure 3.

[0038] As shown in Figure 3, the PC20 includes a CPU201, ROM202, RAM203, auxiliary storage device205, media drive207, display208, network I / F209, keyboard211, mouse212, and DVD (Digital Versatile Disc) drive214.

[0039] The CPU201 is the arithmetic unit that controls the overall operation of the PC20. The ROM202 is a non-volatile memory device that stores programs for the PC20. The RAM203 is a volatile memory device used as the work area for the CPU201.

[0040] The auxiliary storage device 205 is a storage device such as an HDD (Hard Disk Drive) or SSD (Solid State Drive) that stores various data such as print data and programs.

[0041] The media drive 207 is a device that controls the reading and writing of data to a recording medium 206, such as flash memory, according to the control of the CPU 201.

[0042] The display 208 is a display device composed of liquid crystal or organic EL (Electro-Luminescence) or the like, which displays various information such as cursors, menus, windows, characters, or images.

[0043] The network interface 209 is an interface for communicating data with the image forming apparatus 10 using a network. The network interface 209 is, for example, a NIC (Network Interface Card) that supports Ethernet (registered trademark) and is capable of communication compliant with TCP / IP, etc.

[0044] The keyboard 211 is an input device for selecting characters, numbers, various instructions, and moving the cursor. The mouse 212 is an input device for selecting and executing various instructions, selecting the object to be processed, and moving the cursor.

[0045] The DVD drive 214 is a device that controls the reading and writing of data to DVD 213, such as DVD-ROM or DVD-R (Digital Versatile Disk Recordable), which are examples of removable storage media.

[0046] The CPU 201, ROM 202, RAM 203, auxiliary storage device 205, media drive 207, display 208, network interface 209, keyboard 211, mouse 212, and DVD drive 214 are all connected to each other via a bus 210, including an address bus and a data bus.

[0047] Note that the hardware configuration of PC20 shown in Figure 3 is an example, and it is not necessary to include all of the components shown in Figure 3, or other components may be included.

[0048] (Configuration and operation of functional blocks in the image forming system) Figure 4 shows an example of the configuration of a functional block in the image forming system according to this embodiment. Figure 5 is a diagram illustrating the operation when there is no misalignment in the ink landing position in the sub-scanning direction of the liquid ejection head. Figure 6 is a diagram illustrating the operation when there is a misalignment in the ink landing position in the sub-scanning direction of the liquid ejection head. The configuration of the functional block of the image forming system 1 according to this embodiment will be described with reference to Figures 4 to 6.

[0049] As shown in Figure 4, the PC20 includes a communication unit 601, a splitting unit 602, and a print data transmission unit 603.

[0050] The communication unit 601 is a functional unit that performs data communication with the image forming apparatus 10. The communication unit 601 is implemented by the network interface 209 shown in Figure 3.

[0051] The splitting unit 602 is a functional unit that divides the print data to be printed into multiple split print data sets. The splitting unit 602 divides the print data into split print data sets to be assigned to the respective nozzle rows of the liquid discharge head 16U of carriage 15U and the liquid discharge head 16D of carriage 15D.

[0052] Here, using the liquid ejection head 16D as an example, the nozzle configuration of the liquid ejection head 16D and the divided printing data assigned to the liquid ejection head 16D will be explained with reference to Figure 5. The liquid ejection head 16D is assumed to have 100 nozzles, such as nozzles N1 to N100, as shown in Figure 5(a). In Figure 5, the direction from bottom to top is defined as the sub-scanning direction. Nozzles N1 to N100 are formed in a line along the sub-scanning direction, as shown in Figure 5(a). In the example shown in Figure 5(a), nozzles N1 to N100 are arranged in a zigzag pattern along the sub-scanning direction, but this is not the only way; for example, they may be arranged in a straight line along the sub-scanning direction.

[0053] Furthermore, Figure 5(b) shows a part of the pixel configuration of the print data. In Figure 5(b), for convenience, each pixel row in the direction corresponding to the main scanning direction in the print data is numbered. The print target portion PP shown in Figure 5(b) represents the data portion consisting of 100 pixel rows (pixel rows numbered "101" to "200") of the print data used for the ink ejection operation of the liquid ejection head 16D during scanning in the main scanning direction of a certain carriage 15D. That is, the liquid ejection head 16D ejects ink using the data portion of the pixel row numbered "101" at nozzle N1, the data portion of the pixel row numbered "102" at nozzle N2, ..., and the data portion of the pixel row numbered "200" at nozzle N100. Then, in the next scan of carriage 15U, the liquid ejection head 16D ejects ink using the data portion of pixel row number "201" at nozzle N1, the data portion of pixel row number "202" at nozzle N2, ..., and the data portion of pixel row number "300" at nozzle N100. The liquid ejection head 16D repeats this operation until an image is formed for the entire print data. The operation of the liquid ejection head 16U located upstream in the sub-scanning direction is the same as the operation of the liquid ejection head 16D described above.

[0054] Note that the pixel configuration of the print data shown in Figure 5(b) is just one example, and other pixel configurations are also possible. Also, although the number of nozzles shown in Figure 5(a) is 100, it is not limited to this.

[0055] As a result, the liquid ejection head 16D of carriage 15D, which is positioned downstream in the sub-scanning direction, and the liquid ejection head 16U of carriage 15U, which is positioned upstream, cause the ink to land at the same position in the sub-scanning direction, thereby forming a clean print image on the recording medium P as intended. In other words, ideally, the division unit 602 should divide the print data into data portions corresponding to 100 pixel rows, as shown in the print target portion PP in Figure 5(b), to create divided print data. However, in an image forming apparatus equipped with multiple carriages (carriages 15U, 15D), such as the image forming apparatus 10 according to this embodiment, if each carriage is not precisely positioned in the design location, there will be a lack of alignment in the formation positions of the dot rows between the carriages, and a clean print image cannot be obtained when a single print image is formed using all of these carriages. For example, if the carriage 15D is mounted downstream in the sub-scanning direction, shifted by three nozzles of the liquid ejection head 16D from the target position, as shown in Figure 5, when the liquid ejection head 16D ejects ink using the data portion corresponding to the pixel sequences numbered "101" to "200" in the print data, a print image shifted by three pixels downstream will be formed on the recording medium P. In this case, the print image formed by the liquid ejection head 16D will overlap with the print image formed by the liquid ejection head 16U, shifted by three pixels, resulting in an unsatisfactory print image.

[0056] Therefore, in this embodiment, the deviation of the carriage 15D's installation position in the sub-scanning direction from the target position is known in advance, and the liquid ejection head 16D performs ink ejection using the data portion of the divided print data that takes this deviation into account. For example, consider the case where the carriage 15D equipped with the liquid ejection head 16D shown in Figure 6(a) is installed shifted by three nozzles of the liquid ejection head 16D downstream in the sub-scanning direction, as described above. In this case, the liquid ejection head 16D ejects ink using the print target portion PP shown in Figure 6(b), which is shifted by three pixels downstream in the sub-scanning direction compared to the print target portion PP in Figure 5(b). That is, the liquid ejection head 16D ejects ink using the data portion of the pixel row number "98" at nozzle N1, the data portion of the pixel row number "99" at nozzle N2, ..., and the data portion of the pixel row number "197" at nozzle N100. Then, in the next scan of carriage 15U, the liquid ejection head 16D ejects ink using the data portion of pixel row number "198" at nozzle N1, the data portion of pixel row number "199" at nozzle N2, ..., and the data portion of pixel row number "297" at nozzle N100. The liquid ejection head 16D repeats this operation until an image is formed for the entire print data.

[0057] In this way, by using the liquid ejection head 16D to eject ink using a data portion in the print data that has been shifted by the number of pixels corresponding to the misalignment in the installation position of the carriage 15D in the sub-scanning direction, the ink landing positions in the sub-scanning direction can be aligned between the liquid ejection head 16D of the carriage 15D and the liquid ejection head 16U of the carriage 15U, and a clean print image as intended can be formed on the recording medium P.

[0058] However, as described above, even if the splitting unit 602 splits the print data and assigns the print target portion PP (data portion corresponding to the pixel sequence numbers "101" to "200") as split print data to the ink ejection of the liquid ejection head 16D, as shown in Figure 5(b), the split print data does not include the data portion of the pixel sequence numbers "98" to "100". Therefore, ink ejection from the print target portion PP shown in Figure 6(b) is not possible. In this embodiment, when splitting the print data, the splitting unit 602 identifies a data portion shifted by a pixel amount corresponding to the sub-scanning direction shift of the carriage 15D's installation position on the image forming apparatus 10 side, and splits the print data into split print data such that there is redundancy on both sides of the direction corresponding to the sub-scanning direction, so that ink ejection is possible using the identified data portion. In other words, the splitting unit 602 does not split the print data into data portions corresponding to the length of the nozzle row of the liquid ejection head 16D (a data portion consisting of 100 pixel rows in the example of Figure 5), but rather splits the print data into data portions that are extended by a predetermined number of pixels on both sides in the direction corresponding to the sub-scanning direction. For example, if the maximum deviation of the installation position of the carriage 15D in the sub-scanning direction is assumed to be 5 nozzles (5 pixels), then in the examples shown in Figures 5 and 6, the splitting unit 602 does not split the print data into data portions corresponding to pixel rows numbered "101" to "200", data portions corresponding to pixel rows numbered "201" to "300", etc., but rather splits the print data into data portions that are extended by a predetermined number of pixels on both sides in the direction corresponding to the sub-scanning direction, such as data portions corresponding to pixel rows numbered "96" to "205", data portions corresponding to pixel rows numbered "196" to "305", etc. As a result, when the image forming apparatus 10 receives data portions corresponding to pixel sequences numbered "96" to "205" as one of the divided print data, and the carriage 15D is mounted shifted by the width of three nozzles of the liquid ejection head 16D downstream in the sub-scanning direction, as described above, the apparatus can identify data portions corresponding to pixel sequences numbered "98" to "197" from the divided print data and assign them to the liquid ejection head 16D.

[0059] Furthermore, the offset of the carriage 15D's installation position in the sub-scanning direction may be considered as an offset relative to a specific reference position, or as an offset relative to the carriage 15U's installation position. In addition, the division process of the print data by the division unit 602 to accommodate the offset of the carriage 15D's installation position in the sub-scanning direction, and the operation to identify the data portion of the divided print data to be assigned to the liquid ejection head 16D, can also be applied to the carriage 15U and the liquid ejection head 16U.

[0060] Returning to Figure 4, we continue the explanation.

[0061] The print data transmission unit 603 is a functional unit that transmits the divided print data, which has been divided by the division unit 602, to the image forming apparatus 10 via the communication unit 601.

[0062] The division unit 602 and the print data transmission unit 603 described above are implemented, for example, by a program executed by the CPU 201 shown in Figure 3. Note that some or all of these functional units may be implemented not by a software program, but by hardware circuits (integrated circuits) such as FPGAs (Field-Programmable Gate Arrays) or ASICs.

[0063] Note that the functional units of the PC20 shown in Figure 4 are conceptual representations of their functions and are not limited to this configuration. For example, multiple functional units shown as independent functional units in the PC20 in Figure 4 may be configured as a single functional unit. Alternatively, the functions of a single functional unit in the PC20 shown in Figure 4 may be divided into multiple functions and configured as multiple functional units.

[0064] As shown in Figure 4, the image forming apparatus 10 includes a communication unit 501, a print data acquisition unit 502 (acquisition unit), a specification unit 503, an ejection control unit 504, a movement control unit 505, and a storage unit 506.

[0065] The communication unit 501 is a functional unit that performs data communication with the PC 20. The communication unit 501 is implemented by the communication I / F 109 shown in Figure 2.

[0066] The memory unit 506 is a functional unit that pre-stores information indicating the displacement of the installation positions of carriages 15U and carriage 15D in the sub-scanning direction. Here, the extent of the displacement of the installation positions of carriages 15U and carriage 15D in the sub-scanning direction can be obtained, for example, by printing a chart for checking the displacement in advance and checking it, or the image forming apparatus 10 may be equipped with a reading device that reads the printed chart, and the extent of the displacement can be automatically obtained based on the reading data read by the reading device. The obtained information indicating the displacement of the installation positions of carriages 15U and carriage 15D in the sub-scanning direction is then stored in the memory unit 506. Furthermore, when considering the deviation of the installation position of carriage 15D in the sub-scanning direction relative to the installation position of carriage 15U in the sub-scanning direction, it is sufficient to store only the information indicating the deviation of carriage 15D in the storage unit 506. Similarly, when considering the deviation of the installation position of carriage 15U in the sub-scanning direction relative to the installation position of carriage 15D in the sub-scanning direction, it is sufficient to store only the information indicating the deviation of carriage 15U in the storage unit 506. The storage unit 506 is implemented by the RAM 103 or NVRAM 104 shown in Figure 2.

[0067] The print data acquisition unit 502 is a functional unit that acquires split print data from the PC 20 via the communication unit 501.

[0068] The identification unit 503 is a functional unit that reads information from the storage unit 506 indicating the offset of the installation position of carriages 15U and carriage 15D in the sub-scanning direction, and identifies a data portion from each segmented print data acquired by the print data acquisition unit 502 that has been shifted by the pixel amount corresponding to the offset indicated by the information. This provides the data portion used for ink ejection by the liquid ejection head 16U of carriage 15U and the data portion used for ink ejection by the liquid ejection head 16D of carriage 15D.

[0069] The ejection control unit 504 is a functional unit that controls the ejection of ink by the liquid ejection head 16U using the data portion corresponding to the liquid ejection head 16U identified by the identification unit 503, and controls the ejection of ink by the liquid ejection head 16D using the data portion corresponding to the liquid ejection head 16D identified by the identification unit 503. In this case, the ejection control unit 504 controls the ejection of ink by the liquid ejection head 16U via the printing control unit 106U, and controls the ejection of ink by the liquid ejection head 16D via the printing control unit 106D.

[0070] The movement control unit 505 is a functional unit that controls the movement of carriages 15U and carriage 15D in the main scanning direction in response to the discharge control of liquid discharge heads 16U and 16D by the discharge control unit 504. The movement control unit 505 also controls the movement of carriages 15U and carriage 15D in the main scanning direction based on the data portion identified by the identification unit 503. In this case, the movement control unit 505 controls the movement of carriage 15U in the main scanning direction via the main scanning motor drive unit 107U, and controls the movement of carriage 15D in the main scanning direction via the main scanning motor drive unit 107D.

[0071] The aforementioned print data acquisition unit 502, identification unit 503, ejection control unit 504, and movement control unit 505 are implemented, for example, by a program executed by the CPU 101 shown in Figure 2. Note that some or all of these functional units may be implemented not by a software program, but by hardware circuits (integrated circuits) such as FPGAs or ASICs.

[0072] It should be noted that the functional units of the image forming apparatus 10 shown in Figure 4 are conceptual representations of their functions and are not limited to this configuration. For example, the multiple functional units shown as independent functional units in the image forming apparatus 10 in Figure 4 may be configured as a single functional unit. Alternatively, the functions of a single functional unit in the image forming apparatus 10 shown in Figure 4 may be divided into multiple functions and configured as multiple functional units.

[0073] Furthermore, some of the functional functions of the image forming apparatus 10 may be implemented on the PC 20 side, and some of the functional functions of the PC 20 may be implemented on the image forming apparatus 10 side. For example, the operation of dividing print data by the dividing unit 602 of the PC 20 may be performed on the image forming apparatus 10. Also, for example, the operation of identifying data portions of divided print data by the identification unit 503 of the image forming apparatus 10 may be performed on the PC 20.

[0074] (Overall operation flow of the image forming system) Figure 7 is a flowchart showing an example of the overall operation flow of the image forming system according to this embodiment. The overall operation flow of the image forming system 1 according to this embodiment will be explained with reference to Figure 7.

[0075] <Step S11> The division unit 602 of PC20 divides the print data into divided print data to be assigned to the respective nozzle rows of the liquid ejection head 16U of carriage 15U and the liquid ejection head 16D of carriage 15D. In this case, when dividing the print data, the division unit 602 identifies a data portion shifted by a pixel amount corresponding to the sub-scanning direction displacement of the installation positions of carriage 15U and carriage 15D on the image forming apparatus 10 side, and divides the print data into divided print data such that the range has redundancy on both sides in the direction corresponding to the sub-scanning direction so that ink can be ejected using the identified data portion. That is, the division unit 602 divides the print data into divided print data portions that are the size of the data portion corresponding to the length of the nozzle rows of liquid ejection head 16U and liquid ejection head 16D extended by a predetermined pixel amount on both sides in the direction corresponding to the sub-scanning direction. Then, the process proceeds to step S12.

[0076] <Step S12> The print data transmission unit 603 of PC20 transmits the divided print data, which has been divided by the division unit 602, to the image forming apparatus 10 via the communication unit 601. Then, the process proceeds to step S13.

[0077] <Step S13> The print data acquisition unit 502 of the image forming apparatus 10 acquires the divided print data from the PC 20 via the communication unit 501. Then, the process proceeds to step S14.

[0078] <Step S14> The identification unit 503 of the image forming apparatus 10 reads information from the storage unit 506 indicating the offset of the installation position of carriages 15U and carriage 15D in the sub-scanning direction, and identifies the data portion shifted by the pixel amount corresponding to the offset indicated by the information from each segmented print data acquired by the print data acquisition unit 502 as the data portion to be printed and used for ink ejection by the liquid ejection heads 16U and 16D. This provides the data portion used for ink ejection by the liquid ejection head 16U of carriage 15U and the data portion used for ink ejection by the liquid ejection head 16D of carriage 15D. Then, the process proceeds to step S15.

[0079] <Step S15> The ejection control unit 504 of the image forming apparatus 10 controls the ejection of ink by the liquid ejection head 16U using the data portion corresponding to the liquid ejection head 16U identified by the identification unit 503, and controls the ejection of ink by the liquid ejection head 16D using the data portion corresponding to the liquid ejection head 16D identified by the identification unit 503, and performs printing to the recording medium P. At this time, the movement control unit 505 of the image forming apparatus 10 controls the movement of the carriage 15U and carriage 15D in the main scanning direction in accordance with the ejection control of the liquid ejection heads 16U and 16D by the ejection control unit 504.

[0080] After the print data is divided in step S11, steps S12 to S15 are repeated until the printing process for the entire print data is completed.

[0081] As described above, the image forming apparatus 10 according to this embodiment is a serial image forming apparatus equipped with a plurality of carriages each equipped with one or more liquid ejection heads. The print data acquisition unit 502 acquires the divided print data when the print data is divided into divided print data, which is an expanded data portion in the direction corresponding to the transport direction from the data portion of the print data corresponding to the length of the nozzle row in the transport direction of the recording medium P in the liquid ejection head 16D (16U). The identification unit 503 uses the divided print data acquired by the print data acquisition unit 502 to determine the transport The data portion of the nozzle row length, shifted by a pixel amount corresponding to the deviation of the carriage 15D(15U) installation position from the target position in the direction, is identified as the data portion of the print target to be used for ink ejection by the liquid ejection head 16D(16U). The ejection control unit 504 controls the ejection of ink from the liquid ejection head 16D(16U) to the recording medium P using the data portion of the print target identified by the identification unit 503. The movement control unit 505 controls the movement of the carriage 15D(15U) in the main scanning direction based on the data portion of the print target identified by the identification unit 503. More specifically, the print data acquisition unit 502 acquires the divided print data when the print data is divided into divided print data, which is a data portion of a predetermined size extended by a predetermined pixel amount on both sides in the direction corresponding to the transport direction from the data portion of the print data corresponding to the length of the nozzle row. This eliminates the misalignment of ink placement caused by variations in the mounting of multiple carriages (e.g., carriages 15U, 15D) that are arranged in the sub-scanning direction (transport direction).

[0082] In the above-described embodiment, if at least one of the functions of the image forming apparatus 10 and PC20 is realized by program execution, the program is provided pre-installed in ROM or the like. Furthermore, in the above-described embodiment, the program executed by the image forming apparatus 10 and PC20 may be provided as an installable or executable file recorded on a computer-readable recording medium such as a CD-ROM (Compact Disc Read Only Memory), flexible disk (FD), CD-R (Compact Disk-Recordable), or DVD (Digital Versatile Disc). Also, in the above-described embodiment, the program executed by the image forming apparatus 10 and PC20 may be stored on a computer connected to a network such as the Internet and provided by downloading it via the network. Furthermore, in the above-described embodiment, the program executed by the image forming apparatus 10 and PC20 may be provided or distributed via a network such as the Internet. Also, in the above-described embodiment, the program executed by the image forming apparatus 10 and PC20 has a module configuration including at least one of the above-described functional units, and in actual hardware, the CPU reads the program from the above-described storage device and executes it, thereby loading and generating the above-described functional units on the main memory.

[0083] The embodiments of the present invention are as follows. <1> A serial image forming apparatus comprising multiple carriages, each equipped with one or more liquid discharge heads, An acquisition unit that acquires divided print data when the data portion of the print data corresponding to the length of the nozzle row aligned in the transport direction of the recording medium in the liquid discharge head is expanded in the direction corresponding to the transport direction, and the data portion is divided from the print data into divided print data, A selection unit identifies the data portion of the nozzle row length obtained by shifting the length of the carriage in the transport direction by a pixel amount corresponding to the deviation of the carriage's installation position from the target position, in the divided print data acquired by the acquisition unit, as the data portion of the print target to be used for ink ejection by the liquid ejection head. A discharge control unit that controls the ejection of ink from the liquid ejection head to the recording medium using the data portion of the print target identified by the specified unit, A movement control unit controls the movement of the carriage in the main scanning direction based on the data portion to be printed identified by the identification unit, This is an image forming apparatus equipped with the following features. <2> The acquisition unit acquires the divided print data when the print data is divided into divided print data, which is a data portion of a predetermined size that is extended by a predetermined number of pixels on both sides in the direction corresponding to the transport direction from the data portion of the print data corresponding to the length of the nozzle row. <1> This is the image forming apparatus described in [reference]. <3> The system further includes a storage unit that stores information indicating the deviation of the carriage's installation position from the target position in the transport direction, The identifying unit reads the information indicating the misalignment from the storage unit, and identifies the data portion of the nozzle row length obtained by shifting the data from the divided print data by the pixel amount corresponding to the misalignment indicated by the information indicating the misalignment as the data portion to be printed. <1> or <2> This is the image forming apparatus described in [reference]. <4> The plurality of carriages include carriages equipped with liquid ejection heads for ejecting achromatic ink, and carriages equipped with liquid ejection heads for ejecting chromatic ink. <1> ~ <3> The image forming apparatus is one of the items described in any one of the above. <5> An image forming system including a serial image forming apparatus having multiple carriages, each equipped with one or more liquid discharge heads, A splitting unit that splits the print data into split print data, wherein the data portion of the print data corresponding to the length of the nozzle row aligned in the transport direction of the recording medium in the liquid discharge head is expanded in the direction corresponding to the transport direction, and the data portion is expanded in the direction corresponding to the transport direction. An acquisition unit that acquires the divided print data divided by the division unit, A selection unit identifies the data portion of the nozzle row length obtained by shifting the length of the carriage in the transport direction by a pixel amount corresponding to the deviation of the carriage's installation position from the target position, in the divided print data acquired by the acquisition unit, as the data portion of the print target to be used for ink ejection by the liquid ejection head. A discharge control unit that controls the ejection of ink from the liquid ejection head to the recording medium using the data portion of the print target identified by the specified unit, A movement control unit controls the movement of the carriage in the main scanning direction based on the data portion to be printed identified by the identification unit, This is an image forming system that includes [the following components]. <6> The information processing device further includes the division section, The image forming apparatus comprises the acquisition unit, the identification unit, the ejection control unit, and the movement control unit. <5> This is the image forming system described in [reference]. <7> An image forming method for a serial image forming apparatus equipped with multiple carriages, each of which is fitted with one or more liquid discharge heads, An acquisition step to acquire divided print data when the data portion of the print data corresponding to the length of the nozzle row aligned in the transport direction of the recording medium in the liquid discharge head is expanded in the direction corresponding to the transport direction, and the data portion is divided from the print data into divided print data, A selection step in which, in the acquired segmented print data, the data portion of the nozzle row length shifted by a pixel amount corresponding to the deviation of the carriage installation position from the target position in the transport direction is identified as the data portion of the print target to be used for ink ejection by the liquid ejection head, A dispensing control step in which the ink dispensing of the liquid dispensing head to the recording medium is controlled using the identified data portion to be printed, A movement control step that controls the movement of the carriage in the main scanning direction based on the identified data portion to be printed, This is an image forming method that has [a certain characteristic]. <8> A computer that controls a serial-type image forming apparatus equipped with multiple carriages, each having one or more liquid discharge heads, An acquisition step to acquire divided print data when the data portion of the print data corresponding to the length of the nozzle row aligned in the transport direction of the recording medium in the liquid discharge head is expanded in the direction corresponding to the transport direction, and the data portion is divided from the print data into divided print data, A selection step in which, in the acquired segmented print data, the data portion of the nozzle row length shifted by a pixel amount corresponding to the deviation of the carriage installation position from the target position in the transport direction is identified as the data portion of the print target to be used for ink ejection by the liquid ejection head, A dispensing control step in which the ink dispensing of the liquid dispensing head to the recording medium is controlled using the identified data portion to be printed, A movement control step that controls the movement of the carriage in the main scanning direction based on the identified data portion to be printed, This is a program to execute [the command / action]. [Explanation of symbols]

[0084] 1. Image forming system 10 Image forming apparatus 15D, 15U Carriage 16D, 16U liquid dispensing head 17D, 17U Main scanning motor 20 PC 100 Control Unit 101 CPU 102 ROM 103 RAM 104 NVRAM 105 ASIC 106D, 106U Print Control Unit 107D, 107U Main scanning motor drive unit 108 I / O 109 Communication I / F 110 Sub-scanning motor drive unit 120 Control Panel 130 sensors 140D, 140U head drivers 150 Sub-scanning motor 160 Conveyor Rollers 201 CPU 202 ROM 203 RAM 205 Auxiliary storage device 206 Recording media 207 Media Drive 208 displays 209 Network I / F 210 Bus 211 keyboard 212 mice 213 DVD 214 DVD drive 501 Communications Department 502 Print Data Acquisition Unit 503 Specific section 504 Discharge Control Unit 505 Mobile Control Unit 506 Storage section 601 Communications Department 602 Split part 603 Print Data Transmission Unit A1, A2, B (arrow) N1~N100 Nozzles P recording medium PP printing target area [Prior art documents] [Patent Documents]

[0085] [Patent Document 1] Japanese Patent Publication No. 2020-069670

Claims

1. A serial image forming apparatus comprising multiple carriages, each equipped with one or more liquid discharge heads, An acquisition unit that acquires divided print data when the data portion of the print data corresponding to the length of the nozzle row aligned in the transport direction of the recording medium in the liquid discharge head is expanded in the direction corresponding to the transport direction, and the data portion is divided from the print data into divided print data, A selection unit identifies the data portion of the nozzle row length obtained by shifting the length of the carriage in the transport direction by a pixel amount corresponding to the deviation of the carriage's installation position from the target position, in the divided print data acquired by the acquisition unit, as the data portion of the print target to be used for ink ejection by the liquid ejection head. A discharge control unit that controls the ejection of ink from the liquid ejection head to the recording medium using the data portion of the print target identified by the specified unit, A movement control unit controls the movement of the carriage in the main scanning direction based on the data portion to be printed identified by the identification unit, An image forming apparatus equipped with [a specific feature].

2. The image forming apparatus according to claim 1, wherein the acquisition unit acquires divided print data when the print data is divided into divided print data, the data portion of which is extended by a predetermined number of pixels on both sides in the direction corresponding to the transport direction from the data portion of the print data corresponding to the length of the nozzle row.

3. The system further includes a storage unit that stores information indicating the deviation of the carriage's installation position from the target position in the transport direction, The image forming apparatus according to claim 1, wherein the identifying unit reads the information indicating the misalignment from the storage unit, and identifies the data portion of the nozzle row length obtained by shifting the divided print data by the amount of pixels corresponding to the misalignment indicated by the information indicating the misalignment as the data portion to be printed.

4. The image forming apparatus according to claim 1, wherein the plurality of carriages include a carriage equipped with a liquid ejection head for ejecting achromatic ink, and a carriage equipped with a liquid ejection head for ejecting chromatic ink.

5. An image forming system including a serial type image forming apparatus having a plurality of carriages each equipped with one or more liquid discharge heads, A splitting unit that splits the print data into split print data, wherein the data portion of the print data corresponding to the length of the nozzle row aligned in the transport direction of the recording medium in the liquid discharge head is expanded in the direction corresponding to the transport direction, and the data portion is expanded in the direction corresponding to the transport direction. An acquisition unit that acquires the divided print data divided by the division unit, A selection unit identifies the data portion of the nozzle row length obtained by shifting the length of the carriage in the transport direction by a pixel amount corresponding to the deviation of the carriage's installation position from the target position, in the divided print data acquired by the acquisition unit, as the data portion of the print target to be used for ink ejection by the liquid ejection head. A discharge control unit that controls the ejection of ink from the liquid ejection head to the recording medium using the data portion of the print target identified by the specified unit, A movement control unit controls the movement of the carriage in the main scanning direction based on the data portion to be printed identified by the identification unit, An image forming system including [specific components].

6. The information processing device further includes the division section, The image forming apparatus comprises the acquisition unit, the identification unit, the discharge control unit, and the movement control unit, as described in claim 5.

7. An image forming method for a serial image forming apparatus equipped with multiple carriages, each of which is fitted with one or more liquid discharge heads, An acquisition step to acquire divided print data when the data portion of the print data corresponding to the length of the nozzle row aligned in the transport direction of the recording medium in the liquid discharge head is expanded in the direction corresponding to the transport direction, and the data portion is divided from the print data into divided print data, A selection step in which, in the acquired segmented print data, the data portion of the nozzle row length shifted by a pixel amount corresponding to the deviation of the carriage installation position from the target position in the transport direction is identified as the data portion of the print target to be used for ink ejection by the liquid ejection head, A dispensing control step in which the ink dispensing of the liquid dispensing head to the recording medium is controlled using the identified data portion to be printed, A movement control step that controls the movement of the carriage in the main scanning direction based on the identified data portion to be printed, An image forming method having the following characteristics.

8. A computer that controls a serial-type image forming apparatus equipped with multiple carriages, each of which is fitted with one or more liquid discharge heads, An acquisition step to acquire divided print data when the data portion of the print data corresponding to the length of the nozzle row aligned in the transport direction of the recording medium in the liquid discharge head is expanded in the direction corresponding to the transport direction, and the data portion is divided from the print data into divided print data, A selection step in which, in the acquired segmented print data, the data portion of the nozzle row length shifted by a pixel amount corresponding to the deviation of the carriage installation position from the target position in the transport direction is identified as the data portion of the print target to be used for ink ejection by the liquid ejection head, A dispensing control step in which the ink dispensing of the liquid dispensing head to the recording medium is controlled using the identified data portion to be printed, A movement control step that controls the movement of the carriage in the main scanning direction based on the identified data portion to be printed, A program to execute.

Images