JP4652894B2 - Inkjet recording method, inkjet recording apparatus, and program - Google Patents

Description

  The present invention uses a recording head in which a plurality of nozzle arrays are formed, and records images on various recording media by ejecting ink droplets from the nozzles of these nozzle arrays while moving the recording head. The present invention relates to an inkjet recording method, an inkjet recording apparatus, and a program.

  The present invention is applicable to all devices that use recording media such as paper, cloth, leather, nonwoven fabric, OHP paper, and metal. Specific examples of applicable equipment include office equipment such as printers, copiers, and facsimile machines, and industrial production equipment.

  At present, OA devices such as personal computers and word processors are widely used, and various recording devices and recording methods have been developed to record information input by these devices on various recording media. Particularly in OA equipment, video information to be processed tends to be colored as the information processing capability is improved, and colorization is progressing even in a recording apparatus that outputs processing information. There are various recording devices that can record color images depending on the cost and function, etc., and they can be recorded according to the type of image to be recorded and the purpose of use, etc., from an inexpensive one having a relatively simple function. There are a variety of functions that can select speed and image quality.

  Inkjet recording apparatuses are widely used in printers, copiers, facsimiles, and the like because they can reduce noise, reduce running costs, and can be easily downsized, and make it easy to colorize recorded images. Generally, a color ink jet recording apparatus records a color image using three color inks of cyan, magenta, and yellow, or four color inks obtained by adding black to these inks. Further, in a conventional ink jet recording apparatus, in order to record a high color image without ink bleeding, a special paper having an ink absorbing layer is generally used as a recording medium. At present, inks that are suitable for recording on “plain paper” used in large quantities in printers, copiers, and the like have been put into practical use by improving inks.

  In addition, in a so-called serial scan type ink jet recording apparatus, an ink jet recording head provided with nozzle groups corresponding to each ink color used for recording as a recording means for performing color recording using a plurality of colors of ink Is used. The recording head can discharge ink from the discharge ports constituting the nozzles. The serial scan type inkjet recording apparatus has an operation of ejecting ink from its ejection port while moving the recording head in the main scanning direction, and an operation of transporting the recording medium in the sub-scanning direction intersecting the main scanning direction. By alternately repeating the above, images are sequentially recorded on the recording medium. Therefore, as the recording head, a so-called side-by-side recording head is used in which nozzle groups (used nozzle groups) corresponding to each ink color used for recording are sequentially arranged side by side along the main scanning direction. This side-by-side print head can eject ink droplets from the nozzle groups onto the same raster in the same print scan.

  In order to realize high resolution recording in order to record a higher quality image in the ink jet recording apparatus using the side-by-side recording head, a high-density recording head having an increased integration density of recording elements of the recording head including the nozzle is used. It is effective to use. Recently, a high-density recording head using a semiconductor process has appeared, and a high-density recording head having a nozzle row of 600 dpi (about 42.3 μm) has been manufactured.

  Further, in order to arrange the nozzles with higher density, the nozzle row corresponding to one ink color is divided into a plurality of parallel nozzle rows, and the nozzle positions in these nozzle rows are offset by a predetermined amount in the sub-scanning direction. Recording heads were also manufactured. For example, when the nozzle arrangement density in one nozzle row is 600 dpi, two nozzle rows are arranged in parallel, and the nozzle positions in the two nozzle rows are 1200 dpi (about 21.2 μm) in the sub-scanning direction. It can be used as a high-density recording head of 1200 dpi by shifting only by the distance.

  Further, as another method for performing higher image quality recording, it is possible to reduce the size of ink droplets for recording an image. In order to reduce the size of the droplets, it is effective to reduce the size of the recording element of the recording head including the nozzles and use a recording head capable of discharging small droplets of ink. Recently, a recording head having an ink discharge amount of 4 to 5 pl has appeared, and a recording head advantageous for high-definition recording has been manufactured.

  As described above, by ejecting small droplets of ink ejected from nozzles arranged at high density, it becomes possible to record a higher quality image.

  However, when using a side-by-side recording head, in a plurality of nozzle rows arranged in the main scanning direction, there is a possibility that the ejection of ink from each nozzle affects each other. That is, since the ink droplets ejected from the nozzles draw the surrounding air, the recording head moves at high speed in the main scanning direction simultaneously with the ejection of a large number of ink droplets, thereby generating an air flow (airflow). There is a risk of adversely affecting ink ejection.

  Here, the generation mechanism of such airflow will be specifically described. First, the generation of airflow according to the operation of the recording head will be described with reference to FIG.

  FIG. 1 is a top view of the discharge port forming surface of the recording head H, and the discharge ports forming the nozzles N are formed on the discharge port forming surface. L1 and L2 are nozzle rows (nozzle rows), and ink is ejected from each nozzle N in a direction perpendicular to the paper surface of FIG. The recording head H performs recording by ejecting ink from the nozzles N of the nozzle rows L1 and L2 while moving in the main scanning direction indicated by the arrow X in FIG. At that time, the ink droplets ejected vertically below the nozzles N of the nozzle row L1 draw in the surrounding air, creating a “gas wall” that moves in the direction of the arrow X. When the “gas wall” moves in the direction of the arrow X, air wraps around behind the “gas wall”, which becomes an airflow in the direction of arrow A in FIG. As a result of the airflow flowing in front of the nozzle row L2, the ink droplets ejected from the nozzles N of the nozzle row L2 are adversely affected, and there is a possibility that a deviation occurs in the ejection direction.

  FIG. 2 is a view of the recording head H as viewed from the side, and shows the flow of air behind the “gas wall”. By ejecting ink droplets from the nozzles N in the nozzle rows L1 and L2 in the direction of the arrow B, an air flow can be generated from above to below, and the direction of the flow is in the vicinity of the recording medium W as indicated by the arrow A. May change backwards.

  FIG. 3 is a diagram of the recording head H viewed from the front in the main scanning direction, and focuses on the nozzle row L2. In FIG. 3, the ink droplets ejected from the nozzles (end nozzles) located at the end of the nozzle row L2 are ejected in the nozzle row L2 as they approach the recording medium W due to the influence of the airflow in the direction of arrow A. There is a risk of bending inside. When such bending occurs, the ink droplets ejected from the end nozzles land on the recording medium W at positions shifted from the original landing position to the inside of the nozzle row L2, and the ink droplets are ejected. Similar to the case where the direction is shifted or the ink droplets are not ejected, it is recognized as a bad image. This is because both the airflow flowing behind the “gas wall” explained in FIG. 1 and the airflow caused by the ink ejection explained in FIG. 2 influence the ejection of the ink droplets ejected from the end nozzles. This is because the direction is bent.

  As described above, in the conventional recording apparatus using the side-by-side recording heads, there is a possibility that an image defect may be caused by the air flow accompanying the ejection of ink droplets.

  Japanese Patent Application Laid-Open No. 2004-151867 discusses the amount of ink applied in consideration of the relationship between the number of scans (number of passes) and the adverse effect of airflow in a multi-pass printing method in which a predetermined print area is completed by a plurality of scans of the print head. A method of controlling is described. That is, the amount of ink applied is controlled according to the number of passes in order to avoid the adverse effects of airflow.

European Patent Application No. 1405724

  By the way, as a means for responding to the recent demand for higher recording speed, a method of improving the driving frequency of the recording head, that is, increasing the moving speed of the recording head in the main scanning direction can be considered. In that case, the influence of the airflow as described above also changes according to the moving speed of the recording head. For example, even when recording is performed with the same number of passes, if the moving speed of the recording head is different, the degree of influence of the air flow on the ejected ink droplets also varies greatly. Of course, the influence of the airflow increases when the recording head moves at high speed, and the landing accuracy of the ink on the recording medium is deteriorated, and there is a possibility that the image quality is lowered.

  SUMMARY OF THE INVENTION An object of the present invention is to provide an ink jet recording method capable of recording a high-quality image regardless of the moving speed of the recording head by generating recording data so as not to cause an airflow effect accompanying ink ejection. An inkjet recording apparatus and a program are provided.

The ink jet recording method of the present invention has the same color as the first nozzle row in which the nozzles capable of ejecting the first ink droplet are arranged in a predetermined direction and the first ink droplet, and has a larger amount than the first ink droplet. While moving a recording head having at least a second nozzle row in which nozzles capable of ejecting second ink droplets are arranged in the predetermined direction in a direction crossing the predetermined direction, the first An ink jet recording method for recording an image on a recording medium by ejecting the first and second ink droplets from first and second nozzle arrays, wherein the recording head is moved at a first moving speed. A first recording mode for recording an image on the recording medium, and a second recording mode for recording the image on the recording medium by moving the recording head at a second movement speed higher than the first movement speed. of A designation step for designating one recording mode from a plurality of recording modes including a recording mode, and input image data in accordance with the recording mode designated in the designation step. A conversion step of converting the recording data corresponding to each of the first recording mode and the conversion step in the second recording mode per unit area of the recording medium than in the first recording mode. The number of ejections of the second ink droplets can be ejected per unit area of the recording medium in both the first and second recording modes so that the maximum number of ink droplets ejected is reduced. as the relative becomes maximum unit region first ink droplet is not ejected in, characterized by converting the recording data corresponding to each of the first and second nozzle rows To.

The inkjet recording apparatus of the present invention has the same color as the first nozzle row in which the nozzles capable of discharging the first ink droplet are arranged in a predetermined direction and the first ink droplet, and has a larger amount than the first ink droplet. While moving a recording head having at least a second nozzle row in which nozzles capable of ejecting second ink droplets are arranged in the predetermined direction in a direction crossing the predetermined direction, the first An ink jet recording apparatus that records an image on a recording medium by ejecting the first and second ink droplets from the first and second nozzle arrays, wherein the recording head is moved at a first moving speed. A first recording mode for recording an image on the recording medium, and a second recording mode for recording the image on the recording medium by moving the recording head at a second movement speed higher than the first movement speed. of A designation unit for designating one of the plurality of recording modes including the recording mode, and input image data in accordance with the recording mode designated by the designation unit. Conversion means for converting the recording data corresponding to each of the first recording mode and the conversion means in the second recording mode rather than the first recording mode. The number of ejections of the second ink droplets can be ejected per unit area of the recording medium in both the first and second recording modes so that the maximum number of ink droplets ejected is reduced. as the relative becomes maximum unit region first ink droplet is not ejected in, characterized by converting the recording data corresponding to each of the first and second nozzle rows To.

According to the program of the present invention, the first nozzle row in which nozzles capable of ejecting the first ink droplet are arranged in a predetermined direction and the second ink having the same color as the first ink droplet and having a larger amount than the first ink droplet. The first and second nozzle rows while moving a recording head having at least a second nozzle row in which nozzles capable of ejecting ink droplets are arranged in the predetermined direction in a direction intersecting the predetermined direction A program for causing a computer to execute processing for generating recording data for ejecting the first and second ink droplets from the recording medium and recording an image on a recording medium. A first recording mode for recording the image on the recording medium by moving the recording head at a moving speed of the recording medium, and a movement of the recording head at a second moving speed that is faster than the first moving speed. Images on the recording medium A designation step for designating one recording mode from a plurality of recording modes including a second recording mode for recording, and input image data according to the recording mode designated by the designation means. A conversion step of converting into the recording data corresponding to each of the second nozzle arrays, wherein the conversion step is a unit area of the recording medium in the second recording mode rather than in the first recording mode. The number of the first ink droplets per unit area of the recording medium so that the maximum number of the first ink droplets discharged is reduced, and in both the first and second recording modes. as the first ink droplet is not ejected against becomes maximum unit region in can eject the ejection speed, variable on the recording data corresponding to each of the first and second nozzle rows Characterized in that it.

  According to the present invention, the input image data corresponds to each of the plurality of nozzle rows so that the ejection amount per unit area of the ink droplets ejected from the plurality of nozzle rows varies according to the moving speed of the recording head. By converting the recording data into the recording data, the recording data can be generated so that the influence of the air flow accompanying the ink ejection does not occur. As a result, a high-quality image can be recorded regardless of the moving speed of the recording head.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. This example is an application example as a serial printer type inkjet recording apparatus having a plurality of recording heads.

(Configuration of recording device)
FIG. 4 is a schematic perspective view of a main part of an ink jet recording apparatus to which the present invention is applicable.

  In FIG. 4, a plurality (four) of head cartridges 1A, 1B, 1C, 1D are mounted on the carriage 2 in a replaceable manner. Each of the cartridges 1A to 1D includes a recording head capable of ejecting ink, an ink tank unit that supplies ink to the recording head, and a connector that receives a signal for driving the recording head. In the following description, the entire or arbitrary one of the head cartridges 1A to 1D is also referred to as a recording head 1.

  The head cartridges 1A to 1D are for recording using different colors of ink, and for example, cyan (C), magenta (M), yellow (Y), black ( Bk) and the like are stored. Each of the head cartridges 1A to 1D is mounted on the carriage 2 in a replaceable manner. The carriage 2 has a connector holder (electrical connection portion) for transmitting a drive signal and the like to each recording head via a connector on the cartridge 1A to 1D side. ) Is provided.

  The carriage 2 is guided by a guide shaft 3 installed in the apparatus main body so as to be movable in the main scanning direction indicated by an arrow X. The carriage 2 is driven by a main scanning motor 4 via a motor pulley 5, a driven pulley 6, and a timing belt 7, and its position and movement are controlled. A recording medium 8 such as paper or a plastic thin plate is conveyed (paper fed) through a position (recording unit) facing the discharge port surface of the recording head 1 by the rotation of the two sets of conveying rollers 9, 10 and 11, 12. The The ejection port surface of the recording head 1 is a surface on which ejection ports constituting nozzles are formed, and the recording head 1 can eject ink droplets from the ejection port. The back surface of the recording medium 8 is supported by a platen (not shown) so as to form a flat recording surface in the recording unit. The ejection port surface of the recording head 1 in each cartridge mounted on the carriage 2 protrudes downward from the carriage 2 and faces the recording surface of the recording medium 8 between the two sets of transport rollers 9, 10 and 11, 12. To do.

  The recording head 1 of this example is an ink jet recording head that discharges ink using thermal energy, and includes an electrothermal transducer (heater) for generating thermal energy. That is, film boiling occurs in the ink in the nozzles by the thermal energy generated from the electrothermal converter, and ink droplets are ejected from the ejection ports using the pressure change caused by the growth and contraction of the bubbles at that time. The ink ejection method in the recording head 1 is not specified at all. For example, a method of ejecting ink using a piezo element or the like may be used.

  FIG. 5 is a schematic perspective view of the main part of the ink ejection unit 13 in the recording head 1 of this example. In FIG. 5, a plurality of discharge ports 22 are formed at a predetermined pitch on the discharge port surface 21 facing the recording medium 8 with a predetermined gap (about 0.5 to 2 [mm]). . The common liquid chamber 23 to which the ink is supplied and each discharge port 22 are communicated with each other through each flow path 24, and an electrothermal converter (such as a heating resistor) 25 for generating ink discharge energy is provided in each flow path 24. It is arranged along the wall surface. The recording head 1 is mounted on the carriage 2 so that the ejection ports 22 are arranged in a row in a direction that intersects the scanning direction (arrow X direction) of the carriage 2. By driving (energizing) the electrothermal transducer 25 based on the image signal or the ejection signal, the ink in the flow path 24 corresponding to the electrothermal conversion body 25 is film-boiled, and the pressure generated at that time is used from the ejection port 22. Ink droplets can be ejected.

(Configuration of recording system)
FIG. 6 is a block diagram showing a hardware configuration of a recording system that is an example to which the present invention is applied. The system according to the present embodiment generally includes a host device 1000 that performs generation of recording data and UI (user interface) setting for the generation, and an inkjet that forms an image on a recording medium based on the recording data. And a recording apparatus 2000.

  A host device (host computer) 1000 includes a CPU 1001, a ROM 1002, a RAM 1003, a system bus 1004, I / O controllers (CRTC, HDC, FDC, etc.) 1005 for various input / output devices, an external interface (I / F) 1006, External storage devices (HDD / FDD) 1007 such as a hard disk drive (HDD) and floppy (registered trademark) disk drive (FDD), real-time clock (RTC) 1008, CRT 1009, and input devices such as a keyboard and mouse (KeyBoard / Mouse) 1010 and the like.

  The CPU 1001 operates based on an application program, a communication program, a printer driver, an operating system (OS), etc. read into the RAM 1003 from the external storage device 1007 or the like. When the power is turned on, the system functions as a system by booting with the ROM 1002 and loading the OS from the external storage device 1007 or the like into the RAM 1003 and then loading application programs and driver software in the same manner. The external I / F 1006 sequentially transmits the recording data spooled in the RAM 1003 or the external storage device 1007 (HDD) to the recording device 2000. The input device 1010 takes instruction data from the user into the host computer via the I / O controller 1005. The RTC 1008 is for measuring the system time, and acquires and sets time information via the I / O controller 1005. A CRT 1009 is a display device and is controlled by the CRTC in the I / O controller 1005. These blocks of the CRT 1009 and the input device 1010 constitute a user interface.

  FIG. 7 is a block diagram of a control system in the inkjet recording apparatus 2000 of FIG.

  In FIG. 7, a controller 100 is a main control unit. For example, a CPU 101 in the form of a microcomputer, a ROM 103 storing programs, required tables and other fixed data, a RAM 105 provided with an area for expanding recording data, a work area, and the like. And a recording control unit 1010 shown in FIG. Recording data, other commands, status signals, and the like are transmitted and received between the above-described host apparatus 1000 and the controller 100 via an interface (I / F) (not shown).

  The operation unit 120 is a switch group that receives an instruction input from an operator, and includes a power switch 122, a switch 124 for instructing start of printing, a recovery switch 126 for instructing start of suction recovery, and the like. The head driver 140 is a driver that drives an electrothermal converter (hereinafter also referred to as “ejection heater”) 25 of the recording head 1 in accordance with recording data or the like. The head driver 140 includes a shift register that aligns print data corresponding to the position of the discharge heater 25, a latch circuit that latches print data at an appropriate timing, and a logic circuit element that operates the discharge heater 25 in synchronization with a drive timing signal. In addition, a timing setting unit for appropriately setting the drive timing (ejection timing) in order to match the ink dot formation position is provided.

  In this example, a sub heater 142 is provided in the recording head 1. The sub-heater 142 performs temperature adjustment for stabilizing the ink ejection characteristics in the recording head 1. For example, the sub-heater 142 is formed on the substrate of the recording head 1 simultaneously with the ejection heater 25, or the main body or the recording head. It can be configured to be attached to the head cartridge.

  The motor driver 150 is a driver that drives the main scanning motor 4 for moving the carriage 2 in the main scanning direction. The motor driver 160 is a driver that drives a sub-scanning motor 162 for transporting the recording medium 8 in the sub-scanning direction.

  FIG. 8 is a functional block diagram showing a recording system as an example of an application target of the present invention along the flow of recording data. As described above, the recording apparatus 2000 of the present embodiment performs recording using four colors of ink of cyan, magenta, yellow, and black.

  Examples of programs that operate on the operating system of the host apparatus 1000 include applications and printer drivers. The application J0001 executes a process for creating recording data to be recorded by the recording apparatus 2000. The recorded data or the data before the editing or the like can be taken into the host device 1000 in the form of a personal computer (PC) via various media. The PC-type host apparatus 1000 of this example can capture, for example, JPEG image data captured by a digital camera via a CF card. In addition, for example, TIFF format image data read by a scanner or image data stored in a CD-ROM can be captured. Furthermore, data on the WEB can be taken in via the Internet. These captured data are displayed on the monitor of the host apparatus 1000, and edited, processed, etc. via the application J0001, for example, sRGB standard recording data R, G, B are created. In response to a recording instruction, this recording data is passed to the printer driver.

  The printer driver of the present embodiment includes processing units for pre-processing J0002, post-processing J0003, γ correction J0004, halftoning J0005, and print data creation J0006. The pre-stage process J0002 is a process for mapping a color gamut.

  The pre-stage process J0002 of the present embodiment converts 8-bit image data R, G, and B into data R, G, and B in the color gamut of the printing apparatus 2000 by using a three-dimensional LUT and an interpolation operation together. The three-dimensional LUT is a look-up table that contains the relationship of mapping the color gamut reproduced by the image data R, G, B of the sRGB standard into the color gamut reproduced by the recording apparatus 2000 of the printing system.

  The post-stage process J0003 is a process for obtaining the separation data for each ink that reproduces the color represented by this data based on the data R, G, and B on which the color gamut is mapped by the pre-stage process J0002. In this example, separation data for each dot size, that is, separation data Y, M, C, K, SC, and SM is obtained for each ink color of yellow, magenta, cyan, and black, and for cyan and magenta ink colors. Y, M, C, and K are separation data for large dots formed by yellow, magenta, cyan, and black ink, as will be described later, and SC and SM are cyan and magenta, as will be described later. This is the decomposition data for small dots formed by the ink. In the latter stage processing J0003 of the present embodiment, the three-dimensional LUT and the interpolation calculation are used together as in the former stage processing J0002.

  The γ correction J0004 performs gradation value conversion for each of the ink color and the separation data for each dot size obtained by the post-processing J0003. Specifically, by using a one-dimensional LUT corresponding to the gradation characteristics of each color ink used in the recording apparatus 2000, the decomposed data corresponding to the ink color and the dot size is linearly related to the gradation characteristics of the recording apparatus 2000. Convert to match.

  Halftoning J0005 quantizes each of 8-bit color separation data Y, M, C, K, SC, and SM and converts the data into 2-bit data. In this embodiment, 8-bit data is converted into 2-bit data using an error diffusion method. This 2-bit data is index data for indicating an arrangement pattern in a dot arrangement patterning process of the printing apparatus 2000 described later. The recording information creation process J0006 creates recording information by adding recording control information to the recording data containing the 2-bit index data.

  Note that the processing of the application and printer driver described above is performed by the CPU 1001 (see FIG. 6) according to these programs. The program is read from the external storage device 1007 such as the ROM 1002 or the hard disk and used, and the RAM 1003 is used as a work area when executing processing according to the program.

  The recording apparatus 2000 performs a dot arrangement patterning process J0007 and a mask data conversion process J0008 regarding data processing. The dot arrangement patterning process J0007 performs dot arrangement according to a dot arrangement pattern corresponding to 2-bit index data (tone value information) that is recording data for each pixel corresponding to an actual recording image. In this manner, by assigning a dot arrangement pattern corresponding to the gradation value of each pixel to each pixel represented by 2-bit data, dot on / off, that is, dot for each of a plurality of areas in the pixel. Whether or not to form is defined, ejection data of “1” or “0” is arranged for each area in one pixel.

  The 1-bit ejection data obtained in this way is subjected to a mask process by a mask data conversion process J0008. That is, ejection data for each recording scan of the recording head 1 is generated. In multi-pass printing in which a print image of a predetermined area is completed by a plurality of scans of the print head 1, ejection data for each scan is generated by a process using a mask corresponding to each scan. The ejection data Y, M, C, K, SC, and SM for each scan are sent to the head drive circuit (head driver) 140 at an appropriate timing, and the recording head 1 is driven based on the ejection data. Ink is ejected.

  Note that the above-described dot arrangement patterning process J0007 and mask data conversion process J0008 in the printing apparatus 2000 are performed using a dedicated hardware circuit under the control of the CPU 101 (see FIG. 7) that constitutes the control unit of the printing apparatus 2000. Executed. These processes may be executed by the CPU 101 according to a program, or may be executed by, for example, a printer driver in the host device 100 in the form of a personal computer (PC). In applying the present invention, it is apparent from the following description that these processing modes are not limited.

  Further, in this specification, “pixel” is a minimum unit that can express gradation, and image processing of multi-bit multi-bit data (processing such as the above-described pre-processing, post-processing, γ correction, halftoning, etc.) This is the smallest unit that is subject to In the halftoning process, one pixel corresponds to a pattern composed of m × n (for example, 2 × 2) cells, and each cell in one pixel is defined as an “area”. This “area” is a minimum unit in which dot on / off is defined. In this connection, the “image data” referred to in the above-described pre-stage processing, post-stage processing, and γ correction represents a set of pixels to be processed, and each pixel has an 8-bit gradation value in this embodiment. Is the data. Further, the “pixel data” referred to in the above halftoning represents the pixel data itself to be processed, and in the halftoning of the present embodiment, there are two pieces of pixel data containing the above 8-bit gradation value. It is converted into pixel data (index data) containing bit gradation values.

(Airflow control)
FIGS. 9, 10, 11 (a) and 11 (b) are diagrams for explaining a method of airflow control according to the moving speed of the recording head 1. Here, an example of so-called four-pass printing in which an image to be recorded in a predetermined area on a recording medium is completed by four scans of the recording head 1 will be described.

  FIG. 9 is an explanatory diagram of the recording head used in this example, in which nozzle arrays for ejecting cyan (C), magenta (M), yellow (Y), and black (K) inks are formed. As the nozzle rows for cyan ink ejection, nozzle rows C1 and C2 for forming large dots and nozzle rows C3 and C4 for forming small dots are formed so that they are symmetrical in the main scanning direction. It is arranged. The nozzle rows C1 and C3 are adjacent to each other across the common liquid chamber, and the nozzle rows C2 and C4 are adjacent to each other across the common liquid chamber. Similarly, nozzle rows M1 and M2 for forming large dots and nozzle rows M3 and M4 for forming small dots are formed as nozzle rows for discharging magenta ink. In addition, nozzle rows Y1 and Y2 for forming large dots are formed as nozzle rows for discharging yellow ink, and nozzle rows K1 and K2 for forming large dots are similarly formed as nozzle rows for discharging black ink. Yes.

  When such a recording head is used, a color image can be recorded by performing bidirectional recording in the main scanning direction indicated by an arrow X (X1, X2). Hereinafter, the arrow X1 is also referred to as the forward direction, and the arrow X2 is also referred to as the return direction. In such bidirectional recording, for example, nozzle rows C1, C3, M1, M3, K1, K2, Y1, and Y2 are used during forward printing, and nozzle rows C2, C4, M2, M4, K1, K2, and so on during backward printing. By using Y1 and Y2, it is possible to match the order of ink ejection at the time of recording.

  In this example, recording is performed using all nozzle rows during forward recording and backward recording. Thereby, the recording speed can be increased. In that case, the recording data is almost equal to a pair of nozzle rows (a pair of nozzles for forming a large dot or a pair of nozzles for forming a small dot) that eject ink droplets of substantially the same amount of the same color. Allocation (sprinkling process) is performed so that the recording data is not biased to one of the pair of nozzle rows. By using the pair of nozzle rows evenly in this way, it is possible to evenly distribute portions with different ink ejection orders, thereby suppressing the occurrence of color unevenness and applying to the discharge heaters in the respective nozzles. The burden can be distributed. For example, the recording data for forming large dots for ejecting a relatively large amount of cyan ink is developed so as to be distributed evenly to the nozzle rows C1 and C2, and the recording data for forming small dots for ejecting a relatively small amount of cyan ink is: The nozzle rows C3 and C4 are spread out evenly.

  In this example, a nozzle row that forms large dots is a first nozzle row L1, and a nozzle row that forms small dots is a second nozzle row L2. The smaller the distance between the nozzle rows, the greater the influence of the airflow between the nozzles, and the greater the influence of the airflow between the nozzle rows arranged so as to sandwich the common liquid chamber. Further, the influence of the airflow becomes large for the nozzle row having a small ink discharge amount, that is, the nozzle row for discharging a small ink droplet having a small kinetic energy. Furthermore, the higher the moving speed of the recording head, the greater the influence of the airflow.

  In this example, as shown in FIG. 10, when the moving speed of the recording head is different in four-pass printing, the air flow control for suppressing the influence of the air flow between the first nozzle row L1 and the second nozzle row L2. Lines 1401, 1402, 1403 were obtained experimentally.

  In FIG. 10, the vertical and horizontal axes represent the number of dots formed per pixel. Also, as shown in FIG. 9, one large dot forming nozzle is positioned on the same raster (R0 to R15), and similarly, the nozzle is positioned on the same raster (R0 to R15). There is one small dot forming nozzle for each ink color. Therefore, for example, the large dots formed in one pixel by the nozzle row C1 are the largest two dots on the even raster as shown in FIG. 11A, and the small dots formed in one pixel by the nozzle row C3. As shown in FIG. 11B, the maximum number of dots is 2 dots on the odd raster. Therefore, regarding the nozzle row for cyan ink ejection, the horizontal axis in FIG. 10 is the total number of dots formed in one pixel (maximum number 4) by the nozzle rows C1 and C2 as the first nozzle row L1, and FIG. The vertical axis represents the total number of dots formed in one pixel (maximum number 4) by the nozzle rows C3 and C4 as the second nozzle row L2. The recording data for forming large dots is equally distributed to the nozzle rows C1 and C2, and the recording data for forming small dots is equally distributed to the nozzle rows C3 and C4.

  The airflow control lines 1401, 1402, and 1403 represent the ratio between the number of dots formed by the first nozzle row and the number of dots formed by the second nozzle row in one pixel.

  First, based on the airflow control line 1401, the number of dots per pixel formed by the first nozzle row and the second nozzle row will be considered. The upper area of the airflow control line 1401 is an NG area in which it is difficult to record a high-quality image because the influence of the airflow accompanying ink ejection is large. On the other hand, the region where the total number of dots formed by the first nozzle row and the second nozzle row is small, that is, the region below the air flow control line 1401, is less affected by the air flow accompanying ink ejection, and records high-quality images. This is an OK region that is possible. When recording control is performed, recording must be performed based on recording data such that the number of dots formed by the first and second nozzle rows is within the OK region.

  The three air flow control lines 1401, 1402, and 1403 are air flow control lines when the moving speed of the recording head is different in the 4-pass printing. When the moving speed of the recording head is 35 [inch / second], recording data that forms dots in the OK region of the airflow control line 1401 is generated, and an image is recorded based on the recording data. When the moving speed of the recording head is 25 [inch / second], recording data that forms dots in the OK region of the airflow control line 1402 is generated, and an image is recorded based on the recording data. When the moving speed of the recording head is 12.5 [inches / second], recording data that forms dots in the OK region of the airflow control line 1403 is generated, and an image is recorded based on the recording data. . The slower the moving speed of the recording head, the smaller the influence of the air current. Therefore, the slower the moving speed, the higher the air flow control line and the wider the OK region. In this way, recording data is generated so as to form dots in the OK area corresponding to the moving speed of the recording head, and an image is recorded based on the recording data. Therefore, it is possible to realize the recording control without the influence of the airflow regardless of the moving speed of the recording head.

  FIG. 12 is an explanatory diagram of a configuration example of recording data for forming large dots and recording data for forming small dots, and these data are in a 2-bit data format independent of each other. When the recording data for forming large dots is level 1, one large dot is formed per pixel. Similarly, when the recording data for forming small dots is level 1, one small dot is formed per pixel. The In this case, the former level 1 recording data is evenly distributed to a pair of large nozzle forming nozzle arrays (for example, nozzle arrays C1 and C2 in the case of cyan ink), and the latter level 1 recording data. The print data is evenly distributed to a pair of nozzle rows for forming small dots (nozzle rows C3 and C4 in the case of cyan ink).

  FIG. 13 is a block diagram for explaining such a recording data distribution process.

  In the recording control unit 1010 of the inkjet recording apparatus 2000, the reception buffer 1011 receives recording data quantized to 2 bits from the host apparatus 1000, and the dot arrangement pattern storage unit 1012 stores the dot arrangement pattern. The dot arrangement pattern allocation module 1013 executes the dot arrangement patterning process of FIG. 8 described above, and uses the dot arrangement pattern stored in the storage unit 1012 to record the dot arrangement pattern in the recording data in the reception buffer 1011. Is assigned. A development buffer (print buffer) 1014 develops print data according to the dot arrangement pattern assigned by the module 1013. The module 1013 is a software module stored in the ROM 103 (see FIG. 7) and executed by the CPU 101 (see FIG. 7). The reception buffer 1011, the storage unit 1012, and the expansion buffer 1014 are prepared in a predetermined address area of the DRAM.

  In the storage unit 1002, dot arrangement patterns are stored with numbers assigned in advance. As shown in FIG. 12, the dot arrangement pattern is a dot arrangement pattern that can be obtained by recording data (quantized data of levels 0 to 3) for each dot having a different size. Then, a pattern selected from them is developed into a development buffer 1004, and dots are formed according to the developed pattern. In FIG. 13, large cyan is a pattern for forming large dots with cyan ink, small cyan is a pattern for forming small dots with cyan ink, large magenta is a pattern for forming large dots with magenta ink, and small magenta is small with magenta ink. A pattern for forming dots, a large yellow pattern for forming large dots with yellow ink, and a large black pattern for forming large dots with black ink.

  FIG. 14 is a flowchart for explaining data expansion processing by the dot arrangement pattern allocation module 1003.

  First, recording data (2-bit quantized data) transferred from the host apparatus 1000 is received, and the recording data is stored in the reception buffer 1001 (step S1). Then, the recording data for one pixel is read out from the stored recording data (step S2), the dot arrangement pattern corresponding to the level (0 to 3) of the recording data is selected, and the pattern is developed in the development buffer 1005. (Step S3). If there are two dot arrangement patterns for the same level of recording data, one of them is selected and developed. In that case, two dot arrangement patterns of the same level are assigned alternately. In the case of this example, when forming small dots of cyan ink with level 1 print data, two patterns as shown in FIG. 12 are alternately assigned and the print data is evenly distributed to the nozzle rows C3 and C4. Then, it is determined whether or not the expansion to the expansion buffer 1004 has been completed for all the pixels of the recording data stored in the reception buffer 1001 (step S4). If it has not been completed, the process returns to step S2 and is completed. If so, the data expansion process is terminated.

(Generation of recorded data)
FIGS. 15A, 15B and 16C and FIGS. 16A, 16B and 16C show a nozzle array for forming large dots and a nozzle array for forming small dots as shown in FIG. FIG. 6 is a specific explanatory diagram of a method for generating recording data corresponding to the above.

  In the present embodiment, for each gradation level of the recorded image, recording data that is within the OK region of the airflow control line is generated while maintaining gradation. In this example, each nozzle is finally obtained through a series of data processing including data conversion processing in the subsequent stage processing J0003 (see FIG. 8) as shown in FIGS. 15 (a), 15 (b), and 15 (c). Record data corresponding to the column is generated. As described above, the post-stage processing J0003 receives 8-bit luminance data (post-stage processing input data) for R, G, and B, and outputs 8-bit color separation data C, M, Y, K, SC, SM. Convert to (post-processing output data).

  FIGS. 15A, 15B, and 15C are representatively described with respect to generation methods for C data for forming large dots using cyan ink and SC data for forming small dots using cyan ink. FIG. These large and small dots formed by cyan ink are formed using nozzle rows adjacent to each other (nozzle rows C1 (L1) and C3 (L2) in FIG. 9 or C2 (L1) and C4 (L2)). The In FIGS. 15A, 15B, and 15C, for convenience of explanation, G and B data are fixed to (255) among 8-bit data of R, G, and B. Therefore, the post-processing input data (R, G, B) with respect to the horizontal axes of these drawings, that is, R, G, B, represents the change in R data (hue change) when the G and B data are (255). Show. In short, the horizontal axis shows the range from white (255, 255, 255) to the maximum density of cyan (0, 255, 255). On the other hand, the vertical axis in these figures indicates the value of 8-bit post-processing output data (C, SC). Further, the method of data conversion by the post-processing J0003 differs depending on the moving speed of the recording head. In the case of this example, when the moving speed of the recording head is 35 [inch / second], 25 [inch / second], and 12.5 [inch / second], FIGS. Data conversion is performed as in (c).

  FIG. 15A is an explanatory diagram of the subsequent processing that is performed when the recording mode in which the moving speed of the recording head is 35 [inch / second] is designated. As shown in FIG. 15A, when the post-process input data is in the range of (255, 255, 255) to (160, 255, 255), only the SC data is formed so that the image is formed with only small cyan dots. Is output. At this time, SC data is output so that the number of small cyan dots formed gradually increases. When the post-processing input data becomes (160, 255, 255), the output value of the SC data becomes the maximum (about 128). The number of small dots formed at the maximum output value (128) is “2” as shown in FIG. 16A. This “2” is located below the air flow control line 1401 in FIG. Yes. Therefore, the airflow problem does not occur.

  Next, in FIG. 15A, when the post-process input data is in the range of about (160, 255, 255) to (44, 255, 255), image formation is performed with large cyan dots and small cyan dots. Output both C data and SC data. At that time, the C data and the SC data are output so that the number of small cyan dots is gradually decreased and the number of large cyan dots is gradually increased. Specifically, when the post-processing input data becomes (92, 255, 255), the output values of C data and SC data are both about 64, and the number of dot formations at that time is both “1”. (See FIG. 16A). Furthermore, when the post-processing input data becomes (44, 255, 255), the output value of SC data becomes 0 and the output value of C data becomes about 100. The number of dots formed at that time is “0” for small dots and “1.7” for large dots (see FIG. 16A). The case where the number of large dots and the number of small dots are both “1”, or the number of small dots is “0” and the number of large dots is “1.7” is shown in FIG. It is located below the airflow control line 1401. Therefore, the airflow problem does not occur.

  Finally, in FIG. 15A, when the post-processing input data is in the range of (44, 255, 255) to (0, 255, 255), image formation is performed using only large cyan dots. Output only C data. At this time, C data is output so that the number of large cyan dots formed gradually increases. When the post-processing input data becomes (0, 255, 255), the output value of the C data becomes the maximum (about 128). The number of large dots formed at this maximum output value (128) is “2” as shown in FIG. 16A, but this “2” is located below the air flow control line 1401 in FIG. Yes. Therefore, the airflow problem does not occur.

  In this way, in the case of FIG. 15A where the moving speed of the recording head is the fastest, the influence of the air flow is relatively large, and thus the restrictions on the number of large dots and small dots formed are severe. Specifically, the recording corresponding to the large dot nozzle row and the small dot nozzle row is such that the number of large dots and small dots formed falls within the narrow OK region below the print control line 1401 in FIG. Data is being generated. By doing so, the influence of the airflow when the moving speed of the recording head is the fastest is suppressed.

  On the other hand, FIG. 15C is an explanatory diagram of the subsequent processing that is performed when the recording mode of 12.5 [inches / second] in which the moving speed of the recording head is the lowest is designated. As shown in FIG. 15C, the range of post-processing input data in which the formation of small dots is allowed is wider than that in FIG. That is, since the gradation range in which small dots can be used is widened, it is advantageous for reducing the graininess of the highlight portion. Further, in FIG. 15C, the maximum number of small dots and the maximum number of large dots are increased as compared to FIG.

  Further, in FIG. 15C, the maximum total number of large and small dots when the small dots and the large dots are mixed in the unit area is increased as compared with FIG. The greater the influence of airflow, the higher the need to restrict the number of mixed large and small dots. However, the influence of the airflow is smaller in FIG. 15C than in the case of FIG. The restrictions are small, and as a result, the maximum number of mixed large dots and small dots can be increased. As the allowable range of the maximum number of large dots and small dots mixed is wider, a relatively large amount of small dots can be designed at the beginning of large dots, so that the granularity of large dots in the halftone region can be reduced. Also, streaks in the transport direction due to ink droplet ejection deviation are likely to occur from the halftone area to the high density area. However, if the maximum number of large dots and small dots mixed is increased, the number of nozzles involved in recording in this density range can be increased, so that the influence of the above-mentioned deviation can be reduced. In the case of FIG. 15C, the large dot nozzle row and the small dot nozzle row so that the number of large dots and small dots formed falls within the OK region located below the recording control line 1403 in FIG. Recording data corresponding to is generated.

  Specifically, in FIG. 15C, when the post-stage processing input data is in the range of (255, 255, 255) to (160, 255, 255), the output value of the SC data is gradually increased. Let When the post-stage processing input data becomes (160, 255, 255), the output value of the SC data becomes the maximum (about 256). The number of small dots formed at the maximum output value (256) is “4” as shown in FIG. 16C, but this “4” is located below the air flow control line 1403 in FIG. Yes. Therefore, the airflow problem does not occur.

  Next, in FIG. 15C, when the post-stage processing input data is in the range of (160, 255, 255) to (116, 255, 255), the output value of the SC data is kept at the maximum (about 256). , C data is gradually increased. When the post-processing input data becomes (116, 255, 255), as shown in FIG. 16C, the number of small dots formed is “4” and the number of large dots formed is “1”. Since the combination of the number of dots is located below the airflow control line 1403 in FIG. 10, no airflow problem occurs.

  Finally, in FIG. 15C, when the post-stage processing input data is within the range of (116, 255, 255) to (0, 255, 255), the output value of the SC data is gradually decreased, The output value of C data is gradually increased. When the post-processing input data becomes (64, 255, 255), the output values of SC data and C data are both (about 128). At this time, the number of small dots and the number of large dots are both “2” (see FIG. 16C). Since the combination of the number of dots is located below the airflow control line 1403 in FIG. 10, no airflow problem occurs. Further, when the post-stage processing input data becomes (0, 255, 255), the output value of the C data becomes the maximum (about 255). The number of large dots formed at this maximum output value (255) is “4” as shown in FIG. 16C, but this “4” is located below the air flow control line 1403 in FIG. Yes. Therefore, the airflow problem does not occur.

  In this way, in the case of FIG. 15C where the moving speed of the recording head is the slowest, since the influence of the airflow is relatively small, the restrictions on the number of large dots and small dots formed are relatively loose compared to FIG. is doing. Specifically, printing corresponding to the large dot nozzle row and the small dot nozzle row so that the number of large dots and small dots formed is within a large OK region below the print control line 1403 in FIG. Data is being generated. By doing so, the influence of the airflow when the moving speed of the recording head is slow is suppressed.

  When the moving speed of the recording head is 25 [inch / second], as shown in FIG. 15B, the range of the post-processing input data in which the formation of small dots is allowed is wider than that in FIG. This is narrower than that shown in FIG. Therefore, the total number of large and small dots when a small dot and a large dot are mixed in the unit area is larger than that in FIG. 15A, but smaller than that in FIG. 15C. In the case of FIG. 15B, the large dot nozzle row and the small dot nozzle so that the number of large dots and small dots formed is within the OK region located below the recording control line 1402 in FIG. Record data corresponding to the column is generated.

  After generating recording data by a series of data conversion processes including such post-processing J0003, as described above, an image is recorded on the recording medium by ejecting ink from the recording head based on the recording data. .

  FIGS. 16A, 16B, and 16C are based on cyan ink based on print data generated by a series of data conversion processes including the processes of FIGS. 15A, 15B, and 15C. It is explanatory drawing at the time of forming a large dot and a small dot on a to-be-recorded medium.

  The horizontal axis in these figures is the post-stage process input data (R, G, B) in the post-stage process J0003, similarly to the horizontal axes in FIGS. 15 (a), (b), and (c). The left vertical axis represents the number of large dots and small dots formed per unit recording area on the recording medium, and the right vertical axis represents the total amount of cyan ink applied to the unit recording area [pl (picoliters). )], That is, the total amount of cyan ink for forming large dots and small dots.

  The numbers of large dots and small dots formed per unit recording area change in accordance with the moving speed of the recording head. The post-processing output data (C data, SC) shown in FIGS. 15A, 15B, and 15C. As a result, the total amount of cyan ink applied changes linearly with respect to the post-processing input data.

  What is common to FIGS. 15A, 15B, and 15C is that the post-processing input data is in a low concentration region (for example, a range of (255, 255, 255) to (200, 255, 255)). Sometimes, the image is recorded with only small dots in consideration of the graininess of the highlight portion in the recorded image. The number of small dots formed is gradually increased as the post-processing input data increases to increase the recording density. When the post-processing input data is greater than or equal to the halftone level region, it is more efficient to form large dots in order to obtain the required recording density. If an image is recorded using only small dots, the landing accuracy will deteriorate when small ink droplets for forming small dots land on the recording medium, depending on the number of passes in the multi-pass recording method. As a result, the density unevenness may occur in the recorded image. Therefore, in the halftone level region, an image is formed by mixing small dots and large dots. In such a halftone level area to the maximum density area, in order to suppress the influence of the airflow described above, the recording ratio of the nozzle array for forming large dots and the nozzle array for forming small dots is changed to provide large dots. More than small dots.

  In the present embodiment, recording data is generated as described above in consideration of the influence of airflow, the landing accuracy of small ink droplets, and the granularity of a recorded image when large dots are formed. In this way, a good image can be recorded by generating the recording data in consideration of the influence of the airflow that varies depending on the moving speed of the recording head. In this embodiment, the pre-process J1003 performs RGB processing so as to control the ejection amount of ink per pixel (per unit area) ejected from nozzle rows adjacent to each other according to the moving speed of the recording head. Are converted into C, M, Y, K, SC, SM recording data. For example, by providing a table for associating input / output data as shown in FIGS. 15A, 15B, and 15C for each moving speed of the recording head, such a table is used in the pre-stage processing J1003. Data conversion as described above can be performed.

  As described above, print data is generated in order to control the number of dots formed per unit area (per pixel in the above example) formed by a plurality of adjacent nozzle rows in accordance with the moving speed of the print head. Thereby, the influence of the airflow by mutual ink discharge can be suppressed. The influence of the airflow between adjacent nozzle rows changes according to the moving speed of the recording head. Therefore, by generating print data according to the moving speed and controlling the ejection amount of ink ejected from these nozzle rows, optimal control is performed for printing using a plurality of nozzle rows, and high image quality is achieved. Images can be recorded. Controlling the amount of ink ejected from nozzle rows adjacent to each other also controls the ratio of the amount of ink ejected from those nozzle rows.

  In the above-described embodiment, the case of 4-pass printing has been described. However, the number of print passes of the present invention is not limited to “4”. The number of recording passes (N) of the present invention may be an integer, and can be applied to various numbers of passes such as 1 pass, 2 passes, and 8 passes.

  In the above-described embodiment, the form capable of recording large and small dots of the same color has been described. However, the present invention is not limited to such a form. For example, the present invention can be applied to a form in which only a single dot can be recorded for the same color. In this case, it is sufficient to have at least two nozzle rows for ejecting the same color ink, and to generate print data corresponding to the moving speed of the print head for these nozzle rows. Further, the present invention can be applied to a form using inks of similar colors (for example, light cyan ink and dark cyan ink). In this case, the relationship between the large dot and the small dot described above is applied to the dark dot and the light dot, and print data corresponding to the moving speed of the print head is generated for the dark ink nozzle row and the light ink nozzle row. .

(Other embodiments)
By generating the recording data in consideration of the facing distance (inter-paper distance) between the ejection port surface of the recording head and the recording medium, the ink ejection amount (ink droplets) from the adjacent nozzle rows is consequently generated. Can be controlled). When the inter-paper distance is increased, the flying distance of the ink droplet is increased, the flying speed of the ink droplet is decreased, and the kinetic energy is decreased, so that it is easily affected by the air flow. Therefore, print data is generated so as to suppress the influence of the airflow more strongly as the inter-paper distance increases, and as a result, the ink discharge amount from the adjacent nozzle rows is controlled. For example, consider a case where the head moving speed is 12.5 [inches / second]. In this case, as the inter-paper distance increases, the OK area of the airflow control line 1403 in FIG. 10 is narrowed, and data processing is performed so that large dots and small dots are formed in the narrow OK area.

  In addition, when nozzle rows that eject different inks are adjacent, such as nozzle rows C3 and M1 in FIG. 9, print data is generated so as to suppress the influence of airflow on these nozzle rows C3 and M1. As a result, the amount of ink discharged from the nozzle rows C3 and M1 can also be controlled. In such a case, the print data is controlled so that the ink discharge amount is controlled and the influence is avoided by taking into consideration the large influence of the air flow on the nozzle row located on the rear side in the movement direction of the print head with small ink droplets. Can be generated.

  In the case of forward printing in which the printing head moves in the direction of the arrow X1 in FIG. 9, for example, when printing data is generated so as to control the ejection amount as described above for the nozzle rows C2 and C4, the nozzles Considering the presence of the row M2, print data may be generated so as to limit the amount of ink from the nozzle row C4 adjacent to the row M2. Thus, regardless of the type of ink to be ejected, it is possible to generate print data so as to control the ejection amount for suppressing the influence of the airflow on the nozzle rows adjacent to each other. In other words, for the nozzle rows adjacent to each other, the print data is generated so as to control the ink discharge amount per unit area (corresponding to the number of ink droplet discharges), thereby suppressing the influence of the airflow. .

  In addition, not only when the size of the ink droplets ejected from each nozzle row is different, but also when the droplet size is the same, the same effect can be obtained by generating recording data in consideration of the influence of airflow. It is possible to obtain.

  Further, according to the present invention, when a plurality of recording modes having different recording head moving speeds are specified and an image is recorded, ejection is performed from a plurality of nozzle arrays per unit area according to the specified recording mode. It suffices as long as it can generate recording data with different ink ejection amounts. That is, it is only necessary to generate print data that can avoid the influence of the airflow by image processing corresponding to a plurality of print modes in which the moving speed of the print head is different. The recording data can be generated by converting input image data indicating a predetermined luminance level.

(Other)
In the present invention, a software program that realizes the functions of the above-described embodiments is directly or remotely supplied to a system or apparatus, and the computer of the system or apparatus reads and executes the supplied program code. Including the case where it is also achieved by In that case, as long as it has the function of a program, the form does not need to be a program.

  Accordingly, since the functions of the present invention are implemented by computer, the program code installed in the computer also implements the present invention. That is, the claims of the present invention include the computer program itself for realizing the functional processing of the present invention.

  In this case, the program may be in any form as long as it has a program function, such as an object code, a program executed by an interpreter, or script data supplied to the OS.

  As a storage medium for supplying the program, for example, flexible disk, hard disk, optical disk, magneto-optical disk, MO, CD-ROM, CD-R, CD-RW, magnetic tape, nonvolatile memory card, ROM, DVD (DVD-ROM, DVD-R).

  As another program supply method, a client computer browser is used to connect to an Internet homepage, and the computer program itself of the present invention or a compressed file including an automatic installation function is downloaded from the homepage to a storage medium such as a hard disk. Can also be supplied. It can also be realized by dividing the program code constituting the program of the present invention into a plurality of files and downloading each file from a different homepage. That is, a WWW server that allows a plurality of users to download a program file for realizing the functional processing of the present invention on a computer is also included in the scope of the present invention.

  In addition, the program of the present invention is encrypted, stored in a storage medium such as a CD-ROM, distributed to users, and key information for decryption is downloaded from a homepage via the Internet to users who have cleared predetermined conditions. It is also possible to execute the encrypted program by using the key information and install the program on a computer.

  In addition to the functions of the above-described embodiments being realized by the computer executing the read program, the OS running on the computer based on the instruction of the program is a part of the actual processing. Alternatively, the functions of the above-described embodiment can be realized by performing all of them and performing the processing.

  Furthermore, after the program read from the storage medium is written to a memory provided in a function expansion board inserted into the computer or a function expansion unit connected to the computer, the function expansion board or The CPU or the like provided in the function expansion unit performs part or all of the actual processing, and the functions of the above-described embodiments are realized by the processing.

FIG. 6 is a view of a recording head as viewed from the top in order to explain the generation of an air flow accompanying ink ejection. FIG. 4 is a diagram of a recording head viewed from the side in order to explain the generation of an air flow accompanying ink ejection. FIG. 4 is a diagram of a recording head viewed from a traveling direction in order to explain the generation of an air flow accompanying ink ejection. 1 is a partially cutaway perspective view of an inkjet recording apparatus to which the present invention can be applied. FIG. 5 is a schematic perspective view of an ink discharge portion of a recording head used in the ink jet recording apparatus of FIG. 4. It is a schematic block diagram of the recording system containing the inkjet recording device of FIG. FIG. 5 is a block configuration diagram of a control system of the ink jet recording apparatus of FIG. 4. It is a block block diagram of the image processing system in the recording system of FIG. FIG. 5 is an explanatory diagram of a nozzle configuration of a recording head used in the ink jet recording apparatus of FIG. 4. It is explanatory drawing of the airflow control line experimentally obtained in the recording system of FIG. (A) is explanatory drawing of the dot pattern formed by the large nozzle row of the recording head of FIG. 9, (b) is explanatory drawing of the dot pattern formed by the small nozzle row of the recording head of FIG. It is explanatory drawing of the format of the recording data in the recording system of FIG. It is a block block diagram of the recording control part in FIG. It is a flowchart for demonstrating the data expansion | deployment process of the arrangement pattern allocation module in FIG. 8A is an explanatory diagram of an example of recording data converted by the subsequent processing of FIG. 8 when the moving speed of the recording head is 35 [inch / second], and FIG. 8C is an explanatory diagram of an example of the recording data converted by the latter stage processing in FIG. 8, and FIG. 8C is the latter stage in FIG. 8 when the moving speed of the recording head is 12.5 [inch / second]. It is explanatory drawing of an example of the recording data converted by a process. 15A is an explanatory diagram of the relationship between the recording data in FIG. 15A and the ink ejection amount, and FIG. 15B is an explanatory diagram of the relationship between the recording data in FIG. 15B and the ink ejection amount. FIG. 15C is an explanatory diagram of the relationship between the recording data in FIG. 15C and the ink ejection amount.

Explanation of symbols

1 Head cartridge (recording head)
2 Carriage 8 Recording medium 1000 Host device 2000 Recording device J0001 Application J0002 Pre-processing J0003 Post-processing J0004 γ correction J0005 Halftoning J0006 Creation of recording information J0007 Dot arrangement patterning processing J0008 Mask data conversion processing

Claims (5)

A first nozzle row in which nozzles capable of ejecting first ink droplets are arranged in a predetermined direction and a second ink droplet having the same color as the first ink droplet and having a larger amount than the first ink droplet can be ejected. From the first and second nozzle arrays based on the recording data, a recording head having at least a second nozzle array in which the nozzles are arranged in the predetermined direction is moved in a direction crossing the predetermined direction. An inkjet recording method for recording an image on a recording medium by ejecting the first and second ink droplets,
A first recording mode in which the recording head is moved at a first moving speed to record an image on the recording medium; and the recording head is moved at a second moving speed that is faster than the first moving speed. A designation step for designating one recording mode from among a plurality of recording modes including a second recording mode for recording an image on the recording medium.
A conversion step of converting input image data into the recording data corresponding to each of the first and second nozzle rows in accordance with the recording mode specified in the specifying step,
In the converting step, the first recording mode is configured such that the maximum number of ejections of the first ink droplets per unit area of the recording medium is smaller in the second recording mode than in the first recording mode. In both of the second recording mode and the second recording mode, the first ink droplets are ejected from a unit region where the number of ejected second ink droplets is the largest in the number of ejectable per unit region of the recording medium. as not ejected, the ink jet recording method characterized by converting the recording data corresponding to each of the first and second nozzle rows.   In the conversion step, the second recording mode is configured to reduce the maximum number of ejections of the second ink droplets per unit area in the second recording mode and the first recording mode per unit area. 2. The print data corresponding to each of the first and second nozzle arrays is converted so that the maximum number of mixed ejections of the ink droplets and the second ink droplets is reduced. Inkjet recording method.   In the conversion step, when the first recording mode is designated, the number of ejections of the first ink droplets is gradually increased to the maximum in the first density range, and the density is higher than that in the first density range. In the second density range, the number of ejections of the first ink droplets is kept maximum while the number of ejections of the second ink droplets is gradually increased so that the density is higher than that in the second density range. Each of the first and second nozzle arrays using a table that gradually increases the number of ejections of the second ink droplets while gradually decreasing the number of ejections of the first ink droplets in a density range of 3. The inkjet recording method according to claim 1, wherein the recording data is converted into the recording data corresponding to the data. A first nozzle row in which nozzles capable of ejecting first ink droplets are arranged in a predetermined direction and a second ink droplet having the same color as the first ink droplet and having a larger amount than the first ink droplet can be ejected. From the first and second nozzle arrays based on the recording data, a recording head having at least a second nozzle array in which the nozzles are arranged in the predetermined direction is moved in a direction crossing the predetermined direction. An inkjet recording apparatus that records an image on a recording medium by ejecting the first and second ink droplets,
A first recording mode in which the recording head is moved at a first moving speed to record an image on the recording medium; and the recording head is moved at a second moving speed that is faster than the first moving speed. Designation means for designating one recording mode from a plurality of recording modes including a second recording mode for recording an image on the recording medium.
Conversion means for converting input image data into the recording data corresponding to each of the first and second nozzle rows in accordance with the recording mode designated by the designation means;
The converting means is configured so that the maximum number of ejections of the first ink droplets per unit area of the recording medium is smaller in the second recording mode than in the first recording mode. In both of the second recording mode and the second recording mode, the first ink droplets are ejected from a unit region where the number of ejected second ink droplets is the largest in the number of ejectable per unit region of the recording medium. An inkjet recording apparatus, wherein the recording data is converted into the recording data corresponding to each of the first and second nozzle arrays so as not to be ejected. A first nozzle row in which nozzles capable of ejecting first ink droplets are arranged in a predetermined direction and a second ink droplet having the same color as the first ink droplet and having a larger amount than the first ink droplet can be ejected. The first and second nozzle rows from the first and second nozzle rows are moved while moving a recording head including at least a second nozzle row in which different nozzles are arranged in the predetermined direction. A program for causing a computer to execute processing for generating recording data for discharging an ink droplet of 2 to record an image on a recording medium,
The process is
A first recording mode in which the recording head is moved at a first moving speed to record an image on the recording medium; and the recording head is moved at a second moving speed that is faster than the first moving speed. A designation step for designating one recording mode from among a plurality of recording modes including a second recording mode for recording an image on the recording medium.
A conversion step of converting input image data into the recording data corresponding to the first and second nozzle rows in accordance with the recording mode specified by the specifying means,
In the converting step, the first recording mode is configured such that the maximum number of ejections of the first ink droplets per unit area of the recording medium is smaller in the second recording mode than in the first recording mode. In both of the second recording mode and the second recording mode, the first ink droplets are ejected from a unit region where the number of ejected second ink droplets is the largest in the number of ejectable per unit region of the recording medium. A program for converting into the recording data corresponding to each of the first and second nozzle arrays so as not to be ejected.

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