JP2018149755A - Image forming apparatus, ink discharge method, and liquid discharge apparatus - Google Patents

Abstract

An object of the present invention is to enable interlocking operation between control units that control each inkjet head. Kind Code: A1 An image forming apparatus is provided with one or a plurality of heads having nozzle arrays, and forms an image on a recording medium by ejecting inks of different colors from the respective nozzle arrays onto the recording medium. a data sorting unit that extracts color data corresponding to nozzle rows for each print area corresponding to the scanning position of each head from the entire image data related to the entire image formed in the data sorting unit; a plurality of first processing units for inputting data corresponding to each color and executing image processing in each; and one or a plurality of head controllers that respectively control the ink discharge of the corresponding heads according to the corresponding data. [Selection drawing] Fig. 4

Description

  The present invention relates to an image forming apparatus, an ink discharge method for the image forming apparatus, and a liquid discharge apparatus.

  Unlike inkjet printers for home and office use, industrial inkjet printers are equipped with a plurality of inkjet heads in order to increase the speed and increase the number of colors. The number of ink-jet heads to be mounted on an industrial ink-jet printer varies depending on the application and model.

  When installing multiple inkjet heads, using multiple inkjet heads with a common design and combining them to create a single unit reduces development man-hours and costs compared to designing each head individually. Can do.

  A technique is known in which each of the plurality of inkjet heads has a control unit, and each of these head control units controls the ejection of ink from each inkjet head.

  In the case of a configuration having a plurality of head control units, it is necessary for the head control units to operate in conjunction with each other in order to obtain a printed material as expected. And costs tend to increase. If the head control units perform different operations, it is necessary to design each head control unit individually. Therefore, development man-hours and costs are increased accordingly.

  In order to support a plurality of inkjet heads, a technique is disclosed in which one print control device is a master-side controller and another print control device is a slave-side controller (for example, cited document 1). This document discloses a technique in which the master-side controller transmits a command to the carriage system and the transport-system mechanical controller when the command received from the slave-side controller and its own command are complete.

  Although Cited Document 1 refers to a host controller, it does not refer to a head control unit that directly controls an inkjet head.

  An object of the present invention is to enable an interlocking operation between control units that control each inkjet head, and to reduce development man-hours and costs.

  In order to solve the above problems, according to one embodiment of the present invention, one or a plurality of heads including nozzle rows are provided, and inks of different colors are ejected from the nozzle rows to the recording medium, whereby an image is recorded on the recording medium. A color data corresponding to the nozzle row for each print area corresponding to the scanning position of each head, from the entire image data relating to the entire image formed on the recording medium. And a plurality of first processing units for inputting the data corresponding to each of the color data extracted by the data distribution unit and executing image processing in each of the data distribution units, According to the data corresponding to itself among the data after execution of the image processing in the first processing unit, the ink ejection control of the head corresponding to each is controlled. The has one or more head control unit that executes in each.

  According to the present invention, development man-hours and development costs can be suppressed in a configuration having a plurality of control units.

1 is a diagram illustrating a configuration example of an image forming apparatus according to an embodiment. It is a figure which shows the structural example of the inkjet head of this embodiment. It is a figure which illustrates the functional block of 1 head structure of this embodiment. It is a figure which illustrates the functional block of 3 head structure of this embodiment. It is a figure which shows the flowchart of the image process of this embodiment, and shows the example of a process sharing for every function part. It is a figure explaining the data distribution of this embodiment. It is a figure shown about the hardware mounting example by 1 head structure of this embodiment. It is a figure shown about the hardware mounting example by 3 head structure of this embodiment. It is a figure shown about the internal structural example of FPGA of this embodiment.

  In the present embodiment, an image forming apparatus that forms an image of print data transmitted from a host PC (Personal Computer) on a recording medium will be described. The image forming apparatus according to the embodiment is an ink jet printer having one or a plurality of ink jet heads. The image forming apparatus forms an image of print data transmitted from the host PC on the sheet by directly spraying ink onto the sheet from the inkjet head. In the inkjet head, a row of nozzles is formed for each color to be ejected. This row is referred to as a nozzle row.

  The “recording medium” on which an image is formed in the present embodiment is generally a sheet-like member such as paper. Therefore, the description will be made assuming that the image is formed on the sheet. However, in the present embodiment, the image formation target is not limited to this. For example, in addition to general plain paper, in addition to coated paper and label paper, overhead projector sheets, films, flexible thin plates, and the like are targeted. Accordingly, the recording medium is not limited as long as it is capable of adhering with liquid ink, and includes at least temporarily adhering ink, including adhering and fixing, adhering and penetrating. Specific examples include recording media such as paper, recording paper, recording paper, film, and cloth, electronic substrates, electronic parts such as piezoelectric elements (piezoelectric members), powder layers (powder layers), organ models, and examinations. A medium such as a cell. In addition, unless it specifically limits, what consists of all the materials to which a liquid adheres is included, For example, paper, thread | yarn, a fiber, a cloth, leather, a metal, a plastic is included as the material.

  The image forming apparatus according to the embodiment processes the print data transmitted from the host PC in three steps, and forms a processed image on the sheet. As a first step, the image forming apparatus according to the embodiment performs overall data processing on the entire image data formed on one sheet. Next, as a second step, the image forming apparatus performs a data distribution process that distributes the entire image data into data for each inkjet head and for each nozzle row. Then, as a third step, nozzle row data processing is performed in which each data distributed for each inkjet head and for each nozzle row is processed, and each data is individually subjected to image processing in parallel. The image forming apparatus forms an image by ejecting ink of each color from one or a plurality of inkjet heads based on the data after performing each of these processes.

  When there are a plurality of ink jet heads, the image forming apparatus according to the present embodiment has a configuration in which a plurality of head control units are provided so as to be in a one-to-one correspondence with the ink jet heads. When there are a plurality of head controllers, one head controller is set as a master, and the other head controllers are set as slaves. The head control unit set as the master controls the ejection of the inkjet head that is controlled by itself, and outputs a signal for measuring the ejection timing to the other head control unit set as the slave. The head control unit set as a slave inputs a signal generated by the master and performs ejection control on the inkjet head according to the input timing.

  Hereinafter, an image forming apparatus and an ink discharge method according to an embodiment of the present invention will be described in detail with reference to the drawings. First, the configuration of the image forming apparatus according to the present embodiment will be described with reference to FIG.

  The image forming apparatus 1 includes a main control unit 10, an image processing unit 20, a display operation unit 30, an image forming unit 40, and a network I / F 50 (I / F: Interface), which are connected via a bus 70. ing.

  The main control unit 10 includes a CPU (Central Processing Unit) 11, a RAM (Random Access Memory) 12, a ROM (Read Only Memory) 13, and an HDD (Hard Disk Drive) 14, and includes the internal hardware of the image forming apparatus 1. Control all over. The CPU 11 is an arithmetic processing device and controls the operation of the entire image forming apparatus 1. The RAM 12 is a volatile storage medium that can read and write data at high speed, and is used as a work area when the CPU 11 processes information. The ROM 13 is a read-only nonvolatile storage medium, and stores programs such as firmware. The HDD 14 is a non-volatile storage medium that can read and write data, and stores an OS (Operating System), various control programs, application programs, and the like.

  The image processing unit 20 performs image processing on the print data so as to obtain data suitable for the output of the inkjet head as a pre-stage for forming an image on the sheet. The image processing unit 20 performs the overall data processing and data distribution processing described above. The main control unit 10 may execute part or all of the processing performed by the image processing unit 20.

  The display operation unit 30 is a user interface that accepts input of parameters such as the number of copies and a density value from the user during a copy process and displays an operation state and a processing result. The display operation unit 30 includes an LCD (Liquid Crystal Display) 31 and an operation unit 32. The LCD 31 is a visual user interface for the user to check the state of the image forming apparatus 1. The operation unit 32 is a user interface for inputting information to the image forming apparatus 1 such as a physical key or a touch panel.

  The image forming unit 40 forms print data transmitted from a host PC (Personal Computer) 2 and an image read by a scanner on a sheet by discharging ink. The image forming unit 40 performs the nozzle row data processing described above. The detailed configuration of the image forming unit 40 will be described later.

  The network I / F 50 includes an interface board for transmitting / receiving data to / from an external device such as the host PC 2. In the example of FIG. 1, the network I / F 50 receives print data from the host PC 2 and returns a status and a processing result to the host PC 2.

  FIG. 2 is a diagram illustrating the configuration of the inkjet head according to the present embodiment. FIG. 2A illustrates the configuration when there is one ink jet head, and FIG. 2B illustrates the case where there are three ink jet heads that are configured as one unit. Yes.

  The head 41A shown in FIG. 2A has four nozzle rows. In each nozzle row, 320 dots, that is, 320 nozzles are arranged at regular intervals. In this embodiment, a unique identification number is assigned in advance for each nozzle row. In the example of FIG. 2A, cyan (C) is used for the first nozzle row, magenta (M) is used for the second nozzle row, yellow (Y) is used for the third nozzle row, and black (K) is used for the fourth nozzle row. Each color ink is assigned.

  FIG. 2B shows a configuration including three inkjet heads 41A, 41B, and 41C. The heads 41A, 41B, and 41C have the same internal configuration as the head 41A shown in FIG.

  As shown in FIG. 2B, the heads 41A, 41B, and 41C are arranged in the case where one of the end portions in the sub-scanning direction in each nozzle row is the first end portion and the other is the second end portion. The positional relationship is such that the ends of the nozzle rows overlap each other. That is, the head 41A and the head 41B are arranged so that the second end of the nozzle row included in the head 41A and the first end of the nozzle row included in the head 41B overlap each other in the sub-scanning direction. Has been. Further, the second end portion of the nozzle row included in the head 41B and the first end portion of the nozzle row included in the head 41C are in a positional relationship such that they overlap each other in the sub-scanning direction. That is, in the case of the three-head configuration, the heads 41A, 41B, and 41C are arranged in the main direction while maintaining the positional relationship such that the first end and the second end of each nozzle row overlap each other in the sub-scanning direction. In adjacent positions. By arranging the heads 41A, 41B, and 41C in this way, it is possible to increase the printable area in one main scan, and it is possible to improve productivity.

  In the following description, the configuration of one head and the configuration of three heads will be mentioned, but the number of heads and the positional relationship between the heads are merely examples, and various configurations can be considered.

  3 and 4 are functional block diagrams showing the main part of the present embodiment. FIG. 3 shows a configuration example in the case of one head, and FIG. 4 shows a configuration example in the case of three heads.

  The overall data processing unit 21 is a functional unit included in the image processing unit 20 shown in FIG. 1, and is common to both the 1-head configuration and the 3-head configuration. The overall data processing unit 21 performs an image format conversion process and a color tone conversion process on the print data received from the host PC 2. These processes are performed on the entire image formed on one sheet.

  The data distribution unit 22 is a functional unit included in the image processing unit 20 illustrated in FIG. The data distribution unit 22 distributes the image data processed by the overall data processing unit 21 into data in units of heads and nozzles as shown in FIG. In the case of the single head configuration shown in FIG. 2A, the entire image data is converted into four output data of the first nozzle array to the fourth nozzle array, in other words, cyan (C), magenta (M), and yellow (Y). , Black (K) color separation data is created. In the case of the three-head configuration shown in FIG. 2B, the data distribution unit 22 divides the entire image data into data for each head and for each nozzle row, that is, 3 heads × 4 rows = 12 data. As described above, the data distribution unit 22 has different data division methods for the 1-head configuration and the 3-head configuration.

  The nozzle array data processing unit 43A illustrated in FIG. 3 is a functional unit included in the image forming unit 40, and acquires data for each head and nozzle array distributed by the data distribution unit 22. The nozzle array data processing unit 43A performs image processing in parallel for each obtained data. In FIG. 3, the nozzle row data processing unit 43A includes a first nozzle row data processing unit 401A, a second nozzle row data processing unit 402A, a third nozzle row data processing unit 403A, and a fourth nozzle row data processing unit 404A. It has four processing units. The first to fourth nozzle array data processing units in the present embodiment are, for example, first processing units.

  The first nozzle row data processing unit 401A inputs and processes data for ejection by the first nozzle row, that is, cyan (C) data among the data sorted by the data sorting unit 22. The second nozzle row data processing unit 402A inputs and processes data for ejection by the second nozzle row, that is, magenta (M) data among the data sorted by the data sorting unit 22. Similarly, the third nozzle row data processing unit 403A and the fourth nozzle row data processing unit 404A input yellow (Y) and black (K) data, respectively, for processing. In this way, the nozzle row data processing unit 43A calculates data for ejection from each nozzle row of the head 41A in parallel without interfering with each other.

  The head control unit 42A applies a voltage to the pressure chamber wall forming each nozzle of the head 41A according to the calculation result of the nozzle row data processing unit 43A. As a result, the pressure chamber wall is deformed and ink is ejected from each nozzle.

  In the case of the three-head configuration shown in FIG. 4, the image forming apparatus 1 includes nozzle array data processing units 43A, 43B, and 43C corresponding to the heads 41A, 41B, and 41C, respectively. The internal configuration of the nozzle row data processing units 43A, 43B, and 43C is the same as that of the nozzle row data processing unit 43A shown in FIG. 3, and each has first to fourth nozzle row data processing units. The reference numerals of the first to fourth nozzle array data processing units are as shown in FIG. Further, the image forming apparatus 1 includes head control units 42A, 42B, and 42C corresponding to the heads 41A, 41B, and 41C, respectively.

  As shown in FIG. 4, when there are a plurality of inkjet heads, one head controller is a master, and the others are slaves. In this embodiment, the head controller 42A is a master, and the other head controllers 42B and 42C are slaves. The head control unit 42A, which is the master, controls the head 41A and outputs a control signal for measuring the timing for controlling each head to the slave side. The slave head controllers 42B and 42C receive a control signal generated by the master head controller 42A, and perform voltage control on the heads 41B and 41C according to this signal.

  Next, the data processing operation of this embodiment will be described with reference to the flowchart of FIG. As described above, in the present embodiment, the entire data processing, data distribution processing, and nozzle row data processing are performed roughly.

(Whole data processing)
The overall data processing unit 21 of the image processing unit 20 performs printer drawing processing (S51). The printer drawing process is a process for generating a bitmap image, which is raster data, from a page description language (PDL), which is a page description language. The overall data processing unit 21 generates a bitmap image of each color of red (R), green (G), and blue (B).

  The overall data processing unit 21 performs color conversion processing (S52). The color conversion process is a process of converting RGB data of a bitmap image into a color space that matches the ink. In this processing, a color space is converted from RGB data using a prescribed calculation formula. In the present embodiment, the image data is converted into a CMYK color space of cyan (C), magenta (M), yellow (Y), and black (K). In addition to this, depending on the printing mode and device, for example, ink such as CMYKW with white (W) added may be used.

  Next, the overall data processing unit 21 performs gradation processing (S53). In the gradation processing, error diffusion processing or dither processing is used to convert multi-value (8 bits: 256 gradations) data into gradations that the heads 41A to 41C can handle. In the present embodiment, the color reduction conversion is performed to 4 gradations or 2 gradations, but the present invention is not limited to this.

(Data distribution process)
The data distribution unit 22 of the image processing unit 20 performs noise color plate assignment processing (S54). This process will be described with reference to FIG. As shown in FIG. 6A, in the case of the three-head configuration, since the scanning position of each head is determined, the printing area of each head is also determined. In the example of FIG. 6A, the head 41A ejects ink with the printing area A as the scanning target, and the head 41B ejects ink with the printing area B below the printing area A as the scanning object. The head 41C discharges ink with the printing area C below the printing area B as a scanning target. As described above, the heads 41A to 41C have different scanning positions, and eject ink to a printing area corresponding to each scanning position.

  Therefore, an arbitrary pixel in the entire image can be derived from which head data the arbitrary pixel is obtained by knowing the coordinate value of the pixel. The first to fourth nozzle rows also correspond to cyan (C), magenta (M), yellow (Y), and black (K) colors. From this, it is possible to derive from the coordinate value and color of this arbitrary pixel which data is output from which nozzle row of which head for any pixel in the whole image. The table in FIG. 6B summarizes this. The data distribution unit 22 acquires the target pixel from the entire image data, and prints for each of the print areas A to C, cyan (C), magenta (M), yellow (Y), according to the coordinate value and color of the pixel. Data is distributed for each black (K) color. And the data distribution part 22 memorize | stores each data for every head and every nozzle row in a storage area. The data distribution unit 22 stores, for example, data for discharging cyan (C) in the printing area A in the head 41A and the storage area for the first nozzle array. The data distribution unit 22 stores data for ejecting magenta (M) in the printing area A in the head 41A and the storage area for the second nozzle array. The data distribution unit 22 also stores data for ejecting black (K) in the print area C in the head 41C and the storage area for the fourth nozzle array. The same applies to other print areas and colors. As described above, the data distribution unit 22 divides the image data for each area scanned by each head and for each color of the nozzle row, and stores the data in a storage area corresponding to these.

(Nozzle row data processing)
Next, nozzle row data processing will be described. The nozzle row data processing is processing for interpolating mainly the difference between image data and the physical position of the nozzle. In the following description regarding the flowchart of FIG. 5, the nozzle row data processing unit 43A is described, but the same applies to the other nozzle row data processing units 43B and 43C.

  The nozzle array data processing unit 43A of the image forming unit 40 performs sub-scanning interlace processing (S55). Generally, the resolution of a printed document does not match the nozzle resolution that depends on the nozzle spacing. When the nozzle resolution is 150 dpi, for example, and a 600 dpi original is printed at this nozzle resolution, the sheet is moved in the sub-scanning direction in units of 600 dpi, and 4 dots are discharged within 150 dpi in the sub-scanning direction. Thereby, in the sub-scanning direction, it is possible to perform printing at a resolution equivalent to 600 dpi with a nozzle resolution of 150 dpi. When printing a 600 dpi document with a nozzle resolution of 150 dpi, it is necessary to extract data every four lines and input it to the nozzles. This extraction process is called sub-scanning interlace.

  The nozzle array data processing unit 43A performs main scanning thinning processing (S56). The nozzle array data processing unit 43A needs to print the same main scanning line four times, for example, when a document having a resolution of 600 dpi is printed with a nozzle having a resolution of 150 dpi in the main scanning direction. That is, the image forming unit 40 performs printing corresponding to 150 dpi in one scan, and performs printing at a resolution of 600 dpi by performing this four times.

  Further, during printing, an operation for extracting only pixels that eject ink during the scanning, that is, a main scanning thinning process is performed. For example, in the case of a two-pass operation in which the main scanning direction is divided into two prints, the nozzle array data processing unit 43A extracts even-numbered pixels in the 2N-th head scan, and performs the 2N + 1-th head scan. In this case, odd pixels are extracted. Further, in the case of a 4-pass operation in which the main scanning direction is divided into four printings, the nozzle array data processing unit 43A extracts a multiple of 4 pixels during the 4N-th head scanning, and the 4N + 1-th head. In this scanning, a multiple of 4 and the first pixel are extracted. Similarly, in the case of 4N + 2 head scanning, the nozzle array data processing unit 43A extracts a multiple of 4 + second pixel, and in the case of 4N + 3th head scanning, extracts multiple of 4 + third pixel.

  The nozzle row data processing unit 43A performs banding reduction processing (S57). Due to a positional shift that occurs when the head is assembled at the time of manufacturing and a shift in the accuracy of sheet conveyance and feeding, unevenness of the seam between head scans, that is, unevenness of the seam in the sub-scanning direction occurs. In order to obtain a suitable printed matter, it is necessary to make this unevenness inconspicuous. In the present embodiment, several rows of nozzles are overlapped and assembled between the heads, and the nozzle row data processing unit 43A randomly selects which scan to print for the overlapping portion. This process is a banding reduction process.

  The nozzle row data processing unit 43A performs multi-pass interpolation processing (S58). The multi-pass interpolation process is a process for ejecting ink in place of other nozzles when ink clogging occurs in the nozzles of the head.

  The nozzle row data processing unit 43A performs a rotation process (S59). In order to efficiently access the data, the data order in the storage area is rearranged (rotated) in accordance with the order of data supply to the head 41A.

  Next, an implementation example of the present embodiment will be described while exemplifying specific hardware. FIG. 7 is a diagram illustrating a specific mounting example in the case of a one-head configuration, and FIG. 8 is a diagram illustrating a specific mounting example in the case of a three-head configuration. First, the case of one head configuration will be described with reference to FIG. 7, and the difference from the three head configuration will be described with reference to FIG.

  An SoC (System on a Chip) 701 is an integrated circuit specialized for image processing, and has an image processing function mounted on one chip. The SoC 701 includes, for example, a CPU which is an arithmetic processing unit and an I / F connected to a SoC-DDR (Double-Data-Rate) memory 702. The SoC 701 may have a USB-I / F or a Gigabit-Ethernet-I / F for connecting to the host PC 2 and transmitting / receiving data. The SoC 701 corresponds to the image processing unit 20 described above, and executes each process performed by the overall data processing unit 21 and the data distribution unit 22.

  The SoC-DDR memory 702 is a storage unit that has a working storage area for the CPU in the SoC 701 and is used as a buffer for print data.

  The FPGA (field-programmable gate array) 711A is a programmable integrated circuit designed to realize each function of the nozzle array data processing unit 43A and the head control unit 42A. The FPGA-DDR memory 713A is used as a data buffer of the FPGA 711A. The encoder sensor 712A is a sensor for detecting the scanning direction and the amount of movement of the head 41A.

  The host PC 2 transmits the created PDL data to the SoC 701 via USB or Gigabit-Ethernet. This PDL data is stored in the SoC-DDR memory 702 connected to the SoC 701. The SoC 701 performs the entire data processing (S51 to S53) described with reference to FIG. 5 on the PDL data. The SoC 701 stores the data after the gradation processing in Step S53 in the SoC-DDR memory 702.

  Next, the SoC 701 divides the data after gradation processing stored in the SoC-DDR memory 702 into data for each nozzle row according to the color, and stores these nozzle row data in the storage area of the SoC-DDR memory 702, respectively. . Since the example of FIG. 7 has a single head configuration, the data is divided only by the nozzle rows. The case of a multiple head configuration will be described later.

  The SoC 701 notifies the FPGA 711A of information such as the address and data size of the SoC-DDR memory 702 in which the nozzle row data is stored via PCIe (PCI Express).

  Based on the notified information, the FPGA 711A accesses the SoC-DDR memory 702 via PCIe, reads the corresponding nozzle row data, and performs nozzle row data processing. The FPGA-DDR memory 713A is used as a buffer for nozzle row data processing. Further, the FPGA-DDR memory 713A stores data after processing performed by the FPGA 711A.

  The FPGA 711A generates data output timing based on the output from the encoder sensor 712A, inputs the processed nozzle array data from the FPGA-DDR memory 713A, and controls the ink ejection of each nozzle of the head 41A.

  FIG. 8 is a diagram for explaining a mounting example in the case of three heads. In the case of 3 heads, the configuration includes PCIe-Switch 801 to increase the number of connection ports. Further, the FPGAs 711A, 711B, and 711C are connected to the SoC 701 via the PCIe-Switch 801. The FPGAs 711A, 711B, and 711C are devices having the same function, but the FPGA 711A is a master setting, and the FPGAs 711B and 711C are a slave setting.

  The function of the data distribution unit 22 in the SoC 701 differs between the case of 1 head and the case of 3 heads. In the case of a three-head configuration, the SoC 701 extracts data for each head and nozzle row in accordance with the print area and color, and stores the data in the SoC-DDR memory 702.

  The SoC 701 notifies the FPGAs 711A, 711B, and 711C of information such as the address and data size of the SoC-DDR memory 702 in which each nozzle row data is stored via PCIe. Based on the information notified from the SoC 701, the FPGAs 711A, 711B, and 711C each access the SoC-DDR memory 702 via PCIe, read the corresponding nozzle row data, and perform nozzle row data processing.

  The PFGA 711A serving as a master generates data output timing based on the output of the encoder sensor 712A, and outputs a data output timing control signal to the FPGAs 711B and 711C serving as slaves. The FPGA 711A controls the head 41A at the generated timing, and the FPGAs 711B and 711C control the heads 41B and 41C based on the data output timing control signal input from the FPGA 711A.

  FIG. 9 is a diagram for explaining the internal configuration details of the FPGA 711A. The configuration shown in FIG. 9 is the same for the FPGAs 711B and 711C.

  The PCIe-Endpoint 901 is an I / O device for connecting to the outside via PICe. The PCIe-Endpoint 901 is connected to the SoC 701 in the example of FIG. 7, and is connected to the PCIe-Switch 801 in the example of FIG. The PCIe-Endpoint 901 sends an interrupt notification to the SoC 701 via PCIe in accordance with the interrupt request from the interrupt control unit 904. The PCIe-Endpoint 901 outputs the set register value of the FPGA 711 </ b> A to the register control unit 905 via PCIe.

  The DDR memory controller 902 controls the FPGA-DDR memory 713A. The RDMAC 425 of the head control unit 42A is the main body and accesses the FPGA-DDR memory 713A.

  The interconnect 903 arbitrates access requests from the RDMAC 412 and the RDMAC 425, and distributes and outputs access to the PCIe side and access to the FPGA-DDR memory 713A.

  The interrupt control unit 904 makes an interrupt request to the PCIe side based on the interrupt factor from the internal module of the FPGA 711A. The register control unit 905 distributes the register value of the FPGA 711A set via PCIe to each module.

  The nozzle row data processing unit 43A includes four processing units: a first nozzle row data processing unit 401A, a second nozzle row data processing unit 402A, a third nozzle row data processing unit 403A, and a fourth nozzle row data processing unit 404A. . These processing units respectively process the data ejected from each nozzle row associated with each color. The first nozzle array data processing unit 401A processes cyan (C) data ejected from the first nozzle array, and the second nozzle array data processing unit 402A processes magenta (M) data ejected from the second nozzle array. Process. The third nozzle array data processing unit 403A processes yellow (Y) data ejected from the third nozzle array, and the fourth nozzle array data processing unit 404A processes black (K) data ejected from the fourth nozzle array. Process.

  The first nozzle row data processing unit 401A is implemented by each hardware of a nozzle row data processing core 411, an RDMAC (Read Direct Memory Access Controller) 412, and a WDMAC (Write Direct Memory Access Controller) 413. Similarly, the second nozzle row data processing unit 402A, the third nozzle row data processing unit 403A, and the fourth nozzle row data processing unit 404A are implemented by the nozzle row data processing core 411, the RDMAC 412, and the WDMAC 413.

  The RDMAC 412 accesses the SoC-DDR memory 702 via the PCIe-Endpoint 901 and the PCIe, reads data distributed for each nozzle row, and outputs the data to the nozzle row data processing core 411. The WDMAC 413 writes the nozzle row data processed by the nozzle row data processing core 411 to the FPGA-DDR memory 713A. The nozzle row data processing core 411 performs nozzle row data processing, that is, each processing of S55 to S59 shown in FIG. At this time, the nozzle array data processing core 411 inputs the target data via the RDMAC 412 and outputs the calculation result to the FPGA-DDR memory 713A via the WDMAC 413.

  The head control unit 42A includes an RDAMC 425 and a buffer 424 corresponding to each of the four nozzle rows. The RDMAC 425 reads the data of the calculation result performed by the nozzle array data processing core 411 from the FPGA-DDR memory 713A, and outputs it to the buffer 424. Each of the buffers 424 includes two storage areas that can store data of one nozzle row. The RDMAC 425 accesses the FPGA-DDR memory 713A and outputs data to the other storage area of the buffer 424 while the output of the head 41A is being performed with the nozzle array data stored in one storage area of the buffer 424. input. By repeating this operation alternately between the two storage areas, data can be continuously output from the FPGA-DDR memory 713A toward the head 41A.

  The head control unit 42A further includes a data output control unit 421, a selector 422, and a data output timing generation unit 423. The data output control unit 421 controls ink ejection of the head 41A in accordance with the data output timing signal after selection output from the selector 422. The data output timing generation unit 423 measures the timing of data output based on the signal output from the encoder sensor 712A, and generates an internal data output timing control signal and an external data output timing control signal. The data output timing generation unit 423 outputs an internal data output timing control signal to the selector 422, and outputs an external data output timing control signal to the FPGA 711B and the FPGA 711C.

  The selector 422 switches between an external data output timing control signal input from the outside and an internally generated data output timing control signal in accordance with a master / slave setting signal (1: master setting, 0: slave setting). In the case of the master setting, the data output control unit 421 performs data output according to the internal data output timing control signal generated by the data output timing generation unit 423. The external data output timing control signal from the master is input to the selector 422 on the slave side. In the slave setting, the external data output timing control signal is selected by the selector 422, and the data output control unit 421 performs data output according to the external data output timing control signal. In the case of slave setting, the data output timing generation unit 423 is not used because there is no input from the encoder sensor.

  In the above embodiment, the printing operation for accepting a request from the host PC and forming an image on the sheet has been mainly described. In addition to this, the present embodiment is a mode in which an image is formed on a sheet, such as a copying operation or a FAX reception function for reading an original with a scanner incorporated in the image forming apparatus 1 and forming an image on the sheet with the original data. Can be applied.

  As described above, the head control units 42A to 42C and the nozzle array data processing units 43A to 43C are implemented by an FPGA which is a programmable integrated circuit. Therefore, the number of nozzle row data processing units and head control units can be easily increased or decreased according to the increase or decrease of the number of inkjet heads. That is, it can be easily adapted to a model having a large number of heads and a model having a small number of heads. Further, the operations of the nozzle array data processing units are not different from each other in operation, although there are differences in parameters such as from which address in the storage area data is input. Similarly, each of the head controllers has a difference in setting of the master / slave, but there is no difference in operation. Therefore, by manufacturing each functional unit of the nozzle array data processing unit and the head control unit one by one, it is also easy to develop a plurality of the functional units by lateral development. That is, development man-hours and costs can be suppressed.

  In the present embodiment, the description has been made specifically for the image forming apparatus, but the present invention can also be applied to a 3D printing apparatus that manufactures an object by ejecting, for example, a resinous liquid other than ink. Such a 3D printing apparatus inputs data of the entire image to form a stereoscopic image, and manufactures a stereoscopic image using a resinous liquid based on the overall image data.

  3 and 4 has been described as the image forming apparatus 1 in the present embodiment, it may be a 3D printing apparatus. Moreover, you may provide the structure shown in FIG. 3, FIG. 4 as a liquid discharge apparatus. Furthermore, when the configuration of FIGS. 3 and 4 is a liquid ejection apparatus, the liquid ejection apparatus may be incorporated in an image forming apparatus or a 3D printing apparatus. When the configuration of FIGS. 3 and 4 is a liquid ejection device, the operation and mounting described with reference to each drawing are also possible. Further, in the present embodiment, different color inks are ejected from each nozzle row, but the mode is not limited to this, and each of the nozzle rows is arranged according to the properties of the liquid to be ejected, such as viscosity and concentration. The nozzle rows may be divided.

  Image processing is an aspect of data conversion processing that converts original data into other data.

  In the present embodiment, data for controlling ejection by each inkjet head and each nozzle row is extracted from the entire image data, and image processing is performed for each data. That is, in the interlocking operation between the inkjet heads, it is possible to specialize in output timing control without considering image processing. Thereby, the interlocking operation can be simplified.

  As described above, according to the aspect of the present embodiment, the interlocking operation between the head control units that control each inkjet head can be simplified, and in the configuration having a plurality of control units, the development man-hours and development costs can be suppressed. it can.

1: Image forming apparatus, 2: Host PC, 10: Main control unit 11: CPU, 12: RAM, 13: ROM
14: HDD, 20: Image processing unit, 21: Overall data processing unit 22, 22: Data distribution unit, 30: Display operation unit, 31: LCD
32: operation unit, 40: image forming unit, 41A, 41B, 41C: heads 42A, 42B, 42C: head control unit,
43A, 43B, 43C: Nozzle array data processing unit 50: Network I / F, 70: Bus,
401A: first nozzle row data processing unit, 402A: second nozzle row data processing unit 403A: third nozzle row data processing unit, 404A: fourth nozzle row data processing unit 411: nozzle row data processing core, 412: RDMAC
413: WDMAC, 421: Data output control unit, 422: Selector,
423: data output timing generation unit, 424: buffer,
425: RDMAC, 702: SoC-DDR memory,
711A, 711B, 711C: FPGA, 712A: Encoder sensor 713A: FPGA-DDR memory, 902: DDR memory controller 903: interconnect, 904: interrupt control unit,
905: Register control unit

Japanese Patent No. 5651958

Claims (16)

An image forming apparatus that includes one or a plurality of heads each including a nozzle row, and forms an image on the recording medium by ejecting different color inks from the nozzle rows to the recording medium.
A data distribution unit for extracting color data corresponding to the nozzle row for each print region corresponding to the scanning position of each head from the entire image data relating to the entire image formed on the recording medium;
A plurality of first processing units that input data corresponding to the self among the color data extracted by the data distribution unit and execute image processing in each of the data,
One or a plurality of head control units that respectively execute ink ejection control of the corresponding heads according to data corresponding to self among the data after execution of the image processing in the first processing unit. Have
Image forming apparatus. The image forming apparatus according to claim 1.
Each of the head and the head control unit is plural,
Any one of the head control units controls the ink ejection of the head corresponding to the head control unit, and outputs a signal defining the control timing to the other head control unit,
The other head control unit inputs the signal and controls ink ejection of the head corresponding to the head according to the signal.
Image forming apparatus. The image forming apparatus according to claim 1, wherein
And an overall data processing unit that performs image processing on the entire image data formed on the recording medium.
The data distribution unit performs the extraction on the entire image data processed by the entire data processing unit.
Image forming apparatus. The image forming apparatus according to claim 3.
The overall data processing unit executes any or all of printer drawing processing, color conversion processing, and gradation processing as the image processing.
Image forming apparatus. The image forming apparatus according to any one of claims 1 to 4, wherein:
The first processing unit executes, as the image processing, any or all of sub-scanning interlace processing, main-scanning thinning-out processing, banding reduction processing, multi-pass interpolation processing, and rotation processing.
Image forming apparatus. The image forming apparatus according to any one of claims 1 to 5,
The first processing unit and the head control unit are implemented by one or a plurality of integrated circuits that can be increased or decreased according to the number of the heads.
Image forming apparatus. An ink ejection method for an image forming apparatus, which includes one or more heads each including a nozzle row, and forms an image on the recording medium by ejecting different colors of ink from the nozzle rows to the recording medium.
The image forming apparatus includes a plurality of first processing units and one or a plurality of head control units,
From the entire image data relating to the entire image formed on the recording medium, color data corresponding to the nozzle row is extracted for each print region corresponding to the scanning position of each head,
Each of the plurality of first processing units inputs data corresponding to itself among the extracted color data, and executes image processing in each of the data,
One or a plurality of the head control units respectively perform ink ejection control of the head corresponding to the self in accordance with data corresponding to the self after the execution of the image processing in the first processing unit. To
Ink ejection method. The ink discharge method according to claim 7.
The head and the head controller are each a plurality,
Any one of the head control units controls the ink ejection of the head corresponding to the head control unit, and outputs a signal defining the control timing to the other head control unit,
The other head control unit inputs the signal, and controls ink ejection of the head corresponding to itself according to the signal.
Ink ejection method. In the ink ejection method according to claim 7 or 8,
Further, image processing is performed on the entire image data formed on the recording medium.
The extraction is performed on the entire image data after the image processing is performed.
Ink ejection method. The ink ejection method according to claim 9, wherein
The image processing before the extraction is any or all of printer drawing processing, color conversion processing, gradation processing,
Ink ejection method. The ink ejection method according to any one of claims 7 to 10,
The image processing executed by each of the first processing units is any or all of sub-scanning interlace processing, main scanning thinning processing, banding reduction processing, multi-pass interpolation processing, and rotation processing.
Ink ejection method. The ink ejection method according to any one of claims 7 to 11,
The first processing unit and the head control unit are implemented by one or a plurality of integrated circuits that can be increased or decreased according to the number of the heads.
Ink ejection method. A liquid ejection apparatus that includes one or a plurality of heads each including a nozzle row and ejects liquids having different physical properties from each nozzle row,
A data distribution unit for extracting data corresponding to the nozzle row for each region corresponding to the scanning position of each head from the entire image data relating to the entire formed image;
Among the data extracted by the data distribution unit, a plurality of first processing units that input data corresponding to the data and execute data conversion processing in each of the data,
One or a plurality of head controllers that respectively perform liquid ejection control of the heads corresponding to the data corresponding to the data among the data after execution of the data conversion process in the first processor; Having
Liquid ejection device. The liquid ejection apparatus according to claim 13, wherein
Each of the head and the head control unit is plural,
Any one of the head control units controls the liquid ejection of the head corresponding to the head control unit, and outputs a signal defining the control timing to the other head control unit,
The other head control unit inputs the signal, and controls the liquid ejection of the head corresponding to itself according to the signal.
Liquid ejection device. The liquid ejection apparatus according to claim 13 or 14,
Furthermore, it has an overall data processing unit that performs data conversion processing on the overall image data relating to the entire image to be formed,
The data distribution unit performs the extraction on the whole image data after the whole data processing unit has processed.
Liquid ejection device. The liquid ejection device according to any one of claims 13 to 15,
The first processing unit and the head control unit are implemented by one or a plurality of integrated circuits that can be increased or decreased according to the number of the heads.
Liquid ejection device.