Recording apparatus and recording method

Abstract

The present application provides a recording device and a recording method, in order to inhibit the color inversion unevenness and have the improvement margin. The recording device has a longitudinal arrangement type recording head, in the case of performing multiple main scans to the tape area of the medium through the forward scan of the recording head, the sub-scan and the return scan of the recording head to record the image, the following first recording control is performed: the second nozzle group corresponding to the first color among the multiple colored liquid with the lowest ejection ratio for recording the image is set as the first range with the range of the first nozzle adjacent in the second direction in the first nozzle group, the second nozzle group corresponding to the color other than the first color among the multiple colors is set as the second range with the range of the first nozzle adjacent in the second direction in the first nozzle group, the ejection ratio of the colorless liquid in the first range for recording the image is higher than the ejection ratio of the colorless liquid in any second range for recording the image.

Description

Technical Field

[0001] This invention relates to a recording device and a recording method. Background Technology

[0002] A printing apparatus and method are disclosed that use a longitudinally arranged printhead with a row of colored ink nozzles and a row of monochrome ink nozzles, wherein the colored ink nozzles are a group of nozzles with multiple colors of colored ink arranged in a row in the sub-scanning direction (see Patent Document 1).

[0003] According to document 1, the printing data of black ink, equivalent to one band in width of a nozzle group of one colored ink, is divided and printed separately in three alternating scans in the main scanning direction (outgoing, returning, outgoing, returning...) at a ratio of 25%:50%:25%. This divided printing data of black ink is then distributed to the respective ranges of the monochrome ink nozzle columns corresponding to the nozzle groups of cyan, magenta, and yellow. Therefore, not only is the printing order of colored and black ink reversed in adjacent band units, but the total amount of black ink is also approximately consistent in the outgoing and returning scans. This reduces the uneven color reversal caused by the different printing orders of the various colored inks.

[0004] Patent Document 1: Japanese Patent Application Publication No. 2014-195902

[0005] When recording with a vertically arranged head as described above, there is room for further improvement in suppressing uneven color reversal. Summary of the Invention

[0006] The recording device includes: a recording head having multiple nozzle groups, the nozzle groups being arranged in a first direction with multiple nozzles capable of ejecting liquid onto a medium; a transport unit for transporting the medium; and a control unit for controlling the movement of the recording head and the ejection of liquid by the recording head. The recording head, as the multiple nozzle groups, includes: a first nozzle group having multiple first nozzles ejecting a colorless liquid; and a multiple second nozzle group having multiple second nozzles ejecting colored liquids. The multiple second nozzle groups eject mutually different colored liquids. The multiple second nozzle groups are arranged along the first direction, and the first and second nozzle groups are arranged along a second direction intersecting the first direction. The control unit controls the main scan (i.e., the forward scan) by which the recording head ejects liquid along the forward movement of the recording head along the second direction, and the relative movement of the recording head and the medium in the first direction. When recording an image by performing multiple main scans on the band area of ​​the medium during the secondary scan and the main scan (i.e., the retrace scan) as the recording head moves back along the second direction, the following first recording control is performed: when the range of the first nozzles adjacent to the first nozzles in the second direction of the first nozzle group corresponding to the first colored liquid with the lowest ejection ratio for recording the image among the plurality of colored liquids is set as the first range, and the range of the first nozzles adjacent to the first nozzles in the second direction of the first nozzle group is set as the second range for the second nozzle group corresponding to the second colored liquid other than the first colored liquid among the plurality of colored liquids, the ejection ratio of the achromatic liquid used for recording the image in the first range is higher than the ejection ratio of the achromatic liquid used for recording the image in any of the second ranges of the second range.

[0007] A recording method for a recording device, the recording device comprising: a recording head having a plurality of nozzle groups, the nozzle groups being arranged in a first direction with a plurality of nozzles capable of ejecting liquid to a medium; and a conveying unit for conveying the medium, the recording head comprising, as the plurality of nozzle groups, a first nozzle group having a plurality of first nozzles ejecting a colorless liquid; and a plurality of second nozzle groups having a plurality of second nozzles ejecting colored liquids, the plurality of second nozzle groups ejecting mutually different colored liquids, the plurality of second nozzle groups being arranged along the first direction, and the first nozzle groups and the second nozzle groups being arranged along a second direction intersecting the first direction, the recording method comprising a recording step of controlling the movement of the recording head and recording the ejection of liquid by the recording head, wherein, in the recording step, a main scan, i.e., a forward scan, is performed by causing the recording head to eject liquid as the recording head moves forward along the second direction, the recording head... When recording an image by performing multiple main scans on a band area of ​​the medium, including a sub-scan (relative movement of the recording head in the first direction) and a main scan (back scan) (liquid ejection of the recording head as it moves back along the second direction), the ejection ratio of the achromatic liquid used for recording the image is higher than the ejection ratio of the achromatic liquid used for recording the image in any of the second ranges of the second region. This is achieved by performing a sub-scan (relative movement of the recording head in the first direction) and a back scan (liquid ejection of the recording head as it moves back along the second direction). Attached Figure Description

[0008] Figure 1 This is a block diagram that simply illustrates the device configuration of this embodiment.

[0009] Figure 2 It is a diagram that simply shows the relationship between the medium and the recording head from a viewpoint above.

[0010] Figure 3 This is a flowchart illustrating the record control process.

[0011] Figure 4A , Figure 4B These are figures illustrating an example of recording an image onto a medium via a first recording control.

[0012] Figure 5A , Figure 5B These are figures illustrating an example of recording an image onto a medium via a first recording control.

[0013] Figure 6 This is a flowchart illustrating the record control process involved in the variant example.

[0014] Figure 7 This is a diagram used to illustrate an example of recording an image to a medium via a second recording control.

[0015] Explanation of reference numerals in the attached figures

[0016] 10…Recording device; 11…Control unit; 12…Program; 12a…Recording mode determination unit; 12b…Recording data generation unit; 12c…Allocation decision unit; 12d…Recording control unit; 13…Display unit; 14…Operation receiving unit; 15…Storage unit; 16…Communication IF; 17…Transport unit; 18…Carriage; 19…Recording head; 20…Nozzle; 21…Non-colored nozzle group; 21K1, 21K2, 21K3…Nozzle range; 22…Colored nozzle group; 22C, 22M, 22Y…Nozzle group; 30…Media; BD, BD1, BD2, BD3, BD4…Band area; IM1, IM2, IM3, IM4, IM5…Image. Detailed Implementation

[0017] Hereinafter, embodiments of the present invention will be described with reference to the figures. It should be noted that the figures are merely illustrative of these embodiments. As the figures are illustrative, there may be inaccuracies in ratios, shapes, or shades, mismatches, or omissions.

[0018] 1. Brief description of the device's structure:

[0019] Figure 1 The configuration of the recording device 10 according to this embodiment is briefly shown. The recording method of this embodiment is performed by the recording device 10.

[0020] The recording device 10 includes a control unit 11, a display unit 13, an operation receiving unit 14, a storage unit 15, a communication interface 16, a transport unit 17, a carriage 18, and a recording head 19. IF is an abbreviation for interface. The control unit 11 is configured to include one or more ICs such as a CPU 11a, ROM 11b, and RAM 11c that function as a processor, as well as other non-volatile memories.

[0021] In the control unit 11, the processor, i.e., the CPU 11a, uses RAM 11c and other memory as working areas to execute the operation processing according to the program 12 stored in ROM 11b, other memory, etc., thereby realizing various functions such as the recording mode determination unit 12a, the recording data generation unit 12b, the allocation determination unit 12c, and the recording control unit 12d. The processor is not limited to a single CPU; it can also be configured to perform processing through multiple CPUs, ASICs, or other hardware circuits, or it can be configured to perform processing in cooperation between the CPU and hardware circuits.

[0022] Display unit 13 is a unit for displaying visual information, and may be composed of, for example, a liquid crystal display (LCD) or an organic EL display. Display unit 13 may also include a display and a driving circuit for driving the display. Operation receiving unit 14 is a unit for receiving user input, and may be implemented, for example, via physical buttons, a touch panel, a mouse, or a keyboard. Alternatively, a touch panel may be implemented as a function of display unit 13. Display unit 13 and operation receiving unit 14 may also be included together as an operation panel of recording device 10. Display unit 13 and operation receiving unit 14 may be part of the recording device 10, or they may be peripheral devices external to the recording device 10.

[0023] Storage unit 15 is, for example, a storage unit based on hard disk drive, solid-state drive, or other memory. Alternatively, a portion of the memory included in control unit 11 may be incorporated as storage unit 15. Storage unit 15 may also be incorporated as part of control unit 11.

[0024] Communication IF16 is a collective term for one or more IFs used by the recording device 10 to perform wired or wireless communication with external devices based on a communication protocol that includes known communication standards. External devices include, for example, communication devices such as personal computers, servers, smartphones, and tablet terminals.

[0025] The conveying unit 17 is a unit used to convey the medium 30 along a predetermined conveying direction under the control of the control unit 11. The conveying unit 17 may include, for example, a roller that rotates to convey the medium 30, and a motor that serves as a power source for rotation. Alternatively, the conveying unit 17 may also be a mechanism that carries the medium 30 on a belt or tray that is operated by a motor to convey the medium 30. The medium 30 may be, for example, paper, but it can be any medium that can be used for liquid-based recording, and may also be a raw material other than paper, such as film or fabric.

[0026] The carriage 18 is a moving unit that moves back and forth along a predetermined main scanning direction under the control of the control unit 11 and powered by a carriage motor (not shown). The main scanning direction intersects the transport direction. The carriage 18 is equipped with a recording head 19.

[0027] The recording head 19 is a unit that records data by ejecting liquid onto the medium 30 using an inkjet method under the control of the control unit 11. The liquid mainly refers to ink, but the recording head 19 can also eject liquids other than ink.

[0028] The recording device 10 can be implemented as a single printer, or it can be implemented as a system with multiple devices that are communicatively connected. For example, the recording device 10 can be a system that includes an information processing device that acts as a control unit 11, and a printer that includes a transport unit 17, a carriage 18, and a recording head 19, and performs recording under the control of the information processing device. In this case, the information processing device can be used as a recording control device, an image processing device, or the like.

[0029] 2. Description of the record head:

[0030] Figure 2 The relationship between the medium 30 and the recording head 19 is simplified from a top viewpoint. The recording head 19, mounted on the carriage 18, can move forward or backward along the main scanning direction D2 together with the carriage 18. In other words, the movement of the carriage 18 and the movement of the recording head 19 are synonymous. Alternatively, the carriage 18 and the recording head 19 can be collectively understood as the recording head 19 without distinction. For convenience, the movement of the carriage 18 from the negative side to the positive side of the main scanning direction D2 is referred to as "forward movement," and the movement of the carriage 18 from the positive side to the negative side of the main scanning direction D2 is referred to as "return movement."

[0031] The recording head 19 has multiple nozzles 20 for ejecting liquids such as ink. Figure 2 The white circles shown represent individual nozzles 20. The droplets ejected from the nozzles 20 are called dots. The recording head 19 has a nozzle group for each type of liquid. For example, the recording head 19 can eject inks of various colors such as cyan (C), magenta (M), yellow (Y), and black (K). The recording head 19 can also be referred to as a liquid ejection head, printing head, inkjet head, etc.

[0032] like Figure 2 As shown, the nozzle group is broadly divided into a non-colorful nozzle group 21 and a colored nozzle group 22. The colored nozzle group 22 is constructed by arranging multiple nozzle groups 22C, 22M, and 22Y corresponding to different colored liquids along the transport direction D1. At the point where this colored nozzle group 22 is located, the recording head 19 can be considered one of the longitudinally arranged heads. The nozzle group corresponding to a single color of ink is constructed by arranging multiple nozzles 20 along the transport direction D1 with a constant or approximately constant nozzle spacing. The transport direction D1 is orthogonal or approximately orthogonal to the main scanning direction D2. Figure 2In the example, the transport direction D1 is equivalent to the "first direction", and the main scanning direction D2 is equivalent to the "second direction".

[0033] The colorless nozzle group 21 is a nozzle group that includes multiple nozzles 20 that eject K ink, equivalent to the "first nozzle group". Each nozzle 20 constituting the colorless nozzle group 21 is equivalent to the "first nozzle". In addition to K ink, the colorless liquid that the recording head 19 can eject may also include, for example, gray ink, light black ink, etc.

[0034] Nozzle group 22C is a nozzle group comprising multiple nozzles 20 that eject C ink. Similarly, nozzle group 22M is a nozzle group comprising multiple nozzles 20 that eject M ink, and nozzle group 22Y is a nozzle group comprising multiple nozzles 20 that eject Y ink. Within the colored nozzle group 22, nozzle groups 22C, 22M, and 22Y are respectively equivalent to "second nozzle groups," and each nozzle 20 constituting nozzle group 22C, 22M, and 22Y is equivalent to a "second nozzle." It should be noted that the colored liquid ejected by the recording head 19 is not limited to the three colors CMY; it can also be two colors, or even four or more colors.

[0035] according to Figure 2 The direction in which the nozzles 20 constituting the shared nozzle group are arranged (hereinafter referred to as the nozzle arrangement direction) is parallel to the first direction, i.e., the conveying direction D1. However, as part of the configuration of the recording head 19, the nozzle arrangement direction may also intersect at an angle relative to the first direction. Even if the nozzle arrangement direction intersects at an angle relative to the first direction, if the nozzle spacing between the nozzles 20 in the first direction is constant or approximately constant, it is considered that multiple nozzles 20 are arranged in the first direction. Figure 2 In the nozzle group, nozzle groups 21, 22C, 22M, and 22Y are each a nozzle column of nozzle 20 arranged in a straight line. Of course, nozzle groups 21, 22C, 22M, and 22Y can also be composed of multiple nozzle columns.

[0036] The transport section 17 transports the medium 30 from upstream to downstream in the transport direction D1. The upstream and downstream of the transport direction D1 are also simply referred to as upstream and downstream. The non-color nozzle group 21 and the color nozzle group 22 of the recording head 19 are arranged along the main scanning direction D2 and are in the same position in the transport direction D1. Furthermore, it can be understood that the non-color nozzle group 21 and the color nozzle group 22 have the same length in the transport direction D1, and the nozzle groups 22C, 22M, and 22Y within the color nozzle group 22 have the same length in the transport direction D1.

[0037] The length of each nozzle group 22C, 22M, and 22Y along the conveying direction D1 is also referred to as the "belt width". Figure 2In the accompanying drawing, reference numeral 21K1 indicates the range of nozzles 20 in the colorless nozzle group 21 that are adjacent to nozzle group 22C in the main scanning direction D2. The range of a portion of nozzles 20 within a nozzle group is simply referred to as the range, or simply the nozzle range. Similarly, reference numeral 21K2 indicates the range of nozzles 20 in the colorless nozzle group 21 that are adjacent to nozzle group 22M in the main scanning direction D2, and reference numeral 21K3 indicates the range of nozzles 20 in the colorless nozzle group 21 that are adjacent to nozzle group 22Y in the main scanning direction D2. The adjacent range in the main scanning direction D2 means a shared range in the transport direction D1. Therefore, the nozzle ranges 21K1, 21K2, and 21K3 within the colorless nozzle group 21 also have lengths in the transport direction D1 equivalent to the belt width.

[0038] The control unit 11 causes the recording head 19 to spray liquid onto the medium 30 based on the recording data representing the image. As is known, each nozzle 20 in the recording head 19 is provided with a drive element, and the application of drive signals to the drive elements of each nozzle 20 is controlled according to the recording data, so that the image represented by the recording data is recorded onto the medium 30 at the point of ejection or the point of non-ejection of each nozzle 20.

[0039] The liquid ejection by the recording head 19 accompanying the movement of the carriage 18 along the main scan direction D2 is called a "main scan" or "pass". The main scan based on the outward movement of the carriage 18 is called a "forward scan", and the main scan based on the return movement of the carriage 18 is called a "return scan". Recording performed during both the outward and return scans is called bidirectional recording. Furthermore, the relative movement of the recording head 19 and the medium 30 in the first direction is called a "sub-scan". Figure 2 In this configuration, the medium 30 is conveyed to the conveying direction D1 via the conveying unit 17 to perform sub-scanning.

[0040] The control unit 11 records the image represented by the recorded data onto the medium 30 through this forward scan, sub-scan, and return scan. The so-called paper feed, which is a sub-scan between main scans, is a transport of a distance equivalent to the width of the tape. According to... Figure 2 The control unit 11 can complete CMYK ink recording by performing three main scans on a region of one band width in the medium 30, namely the "band area," and feeding paper between these main scans. Figure 2 In the image, a single band region (BD) is shown, enclosed by a double-dotted line. However, recording each band region in three master scans is one example; alternatively, it could be set up as a single colored record with two master scans, resulting in a total of six master scans to record the band region.

[0041] 3. Record control processing:

[0042] Figure 3 The flowchart illustrates the recording control process executed by the control unit 11 according to procedure 12. The flowchart represents the recording method involved in this embodiment.

[0043] In step S100, the recording data generation unit 12b of the control unit 11 acquires image data representing an image of the recording object. The recording data generation unit 12b may acquire, for example, image data stored in a storage location such as the storage unit 15 or a memory inside or outside the recording device 10, image data specified by the user's operation receiving unit 14. Alternatively, the recording data generation unit 12b may receive and acquire image data transmitted from an external device via the communication IF 16.

[0044] In step S110, the recording data generation unit 12b performs various processing on the image data acquired in step S100, such as resolution conversion processing, color conversion processing, and halftone processing, as needed, thereby generating recording data for use in image recording by the recording head 19. For example, through color conversion processing, the value of each pixel constituting the image data is converted to a gray value representing the amount of ink used by the recording head 19 in each CMYK ink. The color system used for the image data is not particularly limited; for example, any RGB image data in which each pixel has a gray value of red (R), gray (G), and blue (B) is acceptable. The recording data generation unit 12b refers to a lookup table that specifies the conversion relationship between RGB and CMYK and converts each gray value of the RGB of each pixel of the image data to each gray value of CMYK. The gray values ​​are represented using, for example, 256 gray levels from 0 to 255.

[0045] The recording data generation unit 12b uses halftone processing, such as dithering or error diffusion, to convert the grayscale values ​​of the CMYK image data (which has undergone color conversion for each pixel) to values ​​representing dots or no dots for each CMYK ink. A dot means the dot is ejected, and no dot means the dot is not ejected. As a result, recording data with dots or no dots is generated for each pixel, specifying the individual CMYK ink values ​​for each pixel.

[0046] In step S120, the allocation decision unit 12c determines the "first colored liquid" with the lowest ejection ratio among the multiple colored liquids used for image recording, based on the recording data generated in step S110. The ejection ratio refers to the amount of liquid ejected per fixed area, also known as the recording rate or duty cycle. The allocation decision unit 12c determines the first colored liquid for each band image. A band image refers to an image of a size recorded in one band region within an image representing one page of the recorded data. Since the size of the band image is known, the allocation decision unit 12c only needs to divide the image represented by the recorded data into multiple band images and determine the first colored liquid for each band image.

[0047] The method for determining the first colored element associated with a single tape image is explained. The allocation determination unit 12c calculates the ratio of the number of pixels with a specified dot to the number of pixels constituting the tape image for each CMY, and sets these ratios as the ejection ratio of each colored element in the tape image. For example, if ink C is a dot in half of the pixels constituting the tape image, then the ejection ratio of C for that tape image is 50%. The allocation determination unit 12c determines the color with the lowest ejection ratio calculated in this way within the CMY as the first colored element of the tape image.

[0048] The emission ratio of each colored element in the tape image can also be calculated based on the recorded data before halftone processing. Specifically, the allocation determination unit 12c can set the emission ratio of a single colored element as the ratio of the sum of the gray values ​​of each pixel of the tape image to the value obtained by multiplying the number of pixels constituting the tape image by the maximum gray value 255, and calculate the emission ratio for each colored element in the same way. In this way, the first colored element is determined for each tape image, but as long as multiple adjacent tape images in the image represented by the recorded data have the same hue, the first colored element determined for each of these multiple tape images also becomes the same color.

[0049] In step S130, the allocation determination unit 12c determines, based on the first colored ink, the range within the colorless nozzle group 21 that is the allocation destination for each CMYK plate of the recording data generated in step S110, which is a plate with dots or no dots (hereinafter referred to as K recording data) that defines the K ink for each pixel. The determination based on step S130 is also performed for each tape image. Specifically, the allocation determination unit 12c determines the allocation destination of the K recording data of the tape image as the range of nozzles 20 in the colorless nozzle group 21 that are adjacent to the second nozzle group corresponding to the first colored ink of the tape image in the main scanning direction D2. The range within the colorless nozzle group 21 determined in step S130 is also referred to as the "first range". Furthermore, the range outside the first range within the colorless nozzle group 21 is equivalent to the "second range".

[0050] For example, let the first color of an image be Y. According to... Figure 2 In the non-colored nozzle group 21, the area adjacent to the second nozzle group 22Y used for ejecting Y ink is nozzle range 21K3. Therefore, the destination for the K recording data of the image is determined to be nozzle range 21K3, which corresponds to the first range, while nozzle ranges 21K1 and 21K2 correspond to the second range. Similarly, if the first colored element of an image is M, the destination for the K recording data of that image is determined to be nozzle range 21K2 adjacent to nozzle group 22M, while other nozzle ranges 21K1 and 21K3 become the second range.

[0051] Needless to say, regardless of which image is included, the destination for allocating the C ink (C recording data) for each pixel in the CMYK plates that constitute the recorded data, whether the C ink has dots or no dots, is nozzle group 22C. Similarly, the destination for allocating the M ink (M recording data) for each pixel, whether the M ink has dots or no dots, is nozzle group 22M, and the destination for allocating the Y ink (Y recording data) for each pixel, whether the Y ink has dots or no dots, is nozzle group 22Y.

[0052] In step S140, the recording control unit 12d performs output processing of the recorded data. That is, the recording control unit 12d controls the transport unit 17 to transport the medium 30 as needed, and forwards each C, M, Y, K recording data with an image to each nozzle 20 according to the allocation decision described above. As a result, for example, during the sequential execution of each process such as outgoing scan, paper feed, return scan, paper feed, outgoing scan, etc., each color dot is ejected from each nozzle 20 to the medium 30 according to the recording data, and the image represented by the recorded data is sequentially recorded to the medium 30 on an image-by-image basis.

[0053] This step S140, and steps S120 and S130 for executing step S140, are equivalent to a "recording process" in which the movement of the recording head 19 and the ejection of liquid by the recording head 19 are controlled to perform recording. Furthermore, the recording process of steps S120 to S140 is also referred to as "first recording control." That is, the control unit 11 performs the following first recording control: the ejection ratio of achromatic liquid used for recording an image in a first range is higher than the ejection ratio of achromatic liquid in any second range used for recording an image. According to the description so far, in the first recording control, the control unit 11 limits the first nozzle that ejects achromatic liquid for recording an image to a first range.

[0054] 4. Explanation of specific examples:

[0055] Figure 4A This diagram illustrates the process of recording image IM1 onto medium 30 via a first recording control and based on recording data, and shows a portion of the recording head 19 and medium 30. Figure 4A China, Belgium Figure 2 Compared to the previous version, the recording header 19 has been simplified. Figure 4AIn the diagram, the slide 18 or nozzle 20 is omitted. In the uncolored nozzle group 21 of the recording head 19, the rectangle marked with reference numeral K1 indicates nozzle range 21K1; similarly, the rectangle marked with reference numeral K2 indicates nozzle range 21K2; and the rectangle marked with reference numeral K3 indicates nozzle range 21K3. Additionally, in the colored nozzle group 22 of the recording head 19, the rectangle marked with reference numeral C indicates nozzle group 22C; the rectangle marked with reference numeral M indicates nozzle group 22M; and the rectangle marked with reference numeral Y indicates nozzle group 22Y.

[0056] Additionally, the numbers 1 to 6, marked in parentheses next to reference numeral 19, indicate which main scan number it represents. Figure 4A The diagram shows the recording head 19 in various scenarios during the first to sixth main scans. Furthermore, the hollow arrow near reference numeral 19 indicates the direction of the main scan, according to... Figure 4A The 1st, 3rd, and 5th odd-numbered main scans are outgoing scans, while the 2nd, 4th, and 6th even-numbered main scans are return scans. Figure 4A In the process, each time the main scan is repeated, it appears that the recording head 19 is moving upstream in the transport direction D1, but in reality, the medium 30 is transported downstream by the paper feed between the main scans in a width-scale manner, thus changing the positional relationship between the recording head 19 and the medium 30 in the transport direction D1.

[0057] exist Figure 4A The image shows four strip regions BD1, BD2, BD3, and BD4 arranged along the transport direction D1 in medium 30. Image IM1 is a uniform, patternless image among the multiple strip images, and the ejection ratios of the CMYK inks specified in the recorded data are C=50%, M=40%, Y=0%, and K=30%. Simply put, image IM1 is a dark blue-toned image. When recording this image IM1, in step S120, for each strip image, the Y with the lowest ejection ratio among the CMY is determined as the first colored element, and in step S130, for each strip image, the nozzle range 21K3 adjacent to nozzle group 22Y is determined as the destination for the K recorded data, i.e., the first range. Figure 4A In the recording head 19, the portion that becomes the destination for the recording data is marked in gray. It should be noted that the gray-marked objects within the recording head 19 are excluded from the case where the ejection ratio is 0%, which is the color of no pixels. This is essentially the same as not allocating recording data to the recording head 19.

[0058] According to this Figure 4AThe result of step S140 is that the band region BD1 of the medium 30 is recorded by the ejection of C ink from the nozzle group 22C as the first main scan, the ejection of M ink from the nozzle group 22M as the second main scan, and the ejection of K ink based on the nozzle range 21K3 as the third main scan. Similarly, the band region BD2 of the medium 30 is recorded by the ejection of C ink from the nozzle group 22C as the second main scan, the ejection of M ink from the nozzle group 22M as the third main scan, and the ejection of K ink based on the nozzle range 21K3 as the fourth main scan. That is, in Figure 4A In this example, only the nozzles 20 of nozzle range 21K3 in the non-color nozzle group 21 eject the K ink corresponding to the K recording data. Therefore, in any band region BD1, BD2, BD3, BD4, the ejection order of each color ink to the medium 30 is C, M, K. Consequently, there will be no color reversal or unevenness between band regions due to the different ejection order of each color ink, resulting in a high-quality recording result without unevenness.

[0059] Figure 4B This is a diagram illustrating the situation of recording image IM2 to medium 30 through a first recording control and based on recording data, and shows a portion of the recording head 19 and medium 30. Figure 4B The following Figure 5A , 5B , Figure 7 The viewing method and Figure 4A Same. Therefore, regarding Figure 4B , Figure 5A , Figure 5B as well as Figure 7 Appropriate application Figure 4A Explanation.

[0060] Image IM2 is a uniform, patternless image among multiple image bands. The ejection ratios of the CMYK inks specified in the recorded data are C=40%, M=0%, Y=50%, and K=30%. Simply put, image IM2 is a dark green image. When recording image IM2, in step S120, for each image band, the M with the lowest ejection ratio among the CMY inks is determined as the first colored ink. In step S130, for each image band, the nozzle range 21K2 adjacent to nozzle group 22M is determined as the destination for the recorded data, i.e., the first range.

[0061] According to this Figure 4BThe result of step S140 is that the band region BD1 of the medium 30 is recorded by the ejection of C ink from the nozzle group 22C as the first main scan, the ejection of K ink based on the nozzle range 21K2 as the second main scan, and the ejection of Y ink from the nozzle group 22Y as the third main scan. Similarly, the band region BD2 of the medium 30 is recorded by the ejection of C ink from the nozzle group 22C as the second main scan, the ejection of K ink based on the nozzle range 21K2 as the third main scan, and the ejection of Y ink from the nozzle group 22Y as the fourth main scan. That is, in Figure 4B In the example, only the nozzles 20 in nozzle range 21K2 of the non-colored nozzle group 21 eject K ink corresponding to the K recording data. Therefore, in any band region BD1, BD2, BD3, BD4, the ejection order of each color ink to the medium 30 is C, K, Y. Consequently, there will be no color reversal or unevenness between band regions due to different ejection orders of the different colors of ink, and a high-quality recording result without unevenness can be obtained.

[0062] Figure 5A This diagram illustrates the process of recording image IM3 onto medium 30 via first recording control and based on recording data, and shows a portion of recording head 19 and medium 30. Image IM3 is a uniform, patternless image among multiple strip images, and the CMYK ink ejection ratios specified in the recording data are C=0%, M=50%, Y=40%, and K=30%. Simply put, image IM2 is a dark red image. When recording image IM3, in step S120, for each strip image, the C with the lowest ejection ratio among the CMY is determined as the first colored element, and in step S130, for each strip image, the nozzle range 21K1 adjacent to nozzle group 22C is determined as the destination for K recording data allocation, i.e., the first range.

[0063] According to this Figure 5A The result of step S140 is that the band region BD1 of the medium 30 is recorded by the ejection of K ink based on the nozzle range 21K1 of the forward scan as the first main scan, the ejection of M ink by the nozzle group 22M of the return scan as the second main scan, and the ejection of Y ink by the nozzle group 22Y of the forward scan as the third main scan. Similarly, the band region BD2 of the medium 30 is recorded by the ejection of K ink based on the nozzle range 21K1 of the return scan as the second main scan, the ejection of M ink by the nozzle group 22M of the forward scan as the third main scan, and the ejection of Y ink by the nozzle group 22Y of the return scan as the fourth main scan. That is, in Figure 5A In the example, only the nozzles 20 within nozzle range 21K1 of the non-colored nozzle group 21 eject K ink corresponding to the K recording data. Therefore, in any band region BD1, BD2, BD3, BD4, the ejection order of each color ink onto the medium 30 is K, M, Y. Consequently, there is no color reversal or unevenness between band regions due to different ejection orders of the different colors, resulting in a high-quality recording result without unevenness.

[0064] Figure 5B This diagram illustrates the process of recording image IM4 onto medium 30 via first recording control and based on recording data, and shows a portion of recording head 19 and medium 30. Image IM4 is a uniform, patternless image among multiple tape images, and the CMYK ink ejection ratios specified in the recording data are C=35%, M=35%, Y=25%, and K=20%. Simply put, image IM4 is a dark grayscale image. When recording image IM4, in step S120, for each tape image, Y, with the lowest ejection ratio among the CMY, is determined as the first colored element, and in step S130, for each tape image, the nozzle range 21K3 adjacent to nozzle group 22Y is determined as the destination for K recording data allocation, i.e., the first range.

[0065] According to this Figure 5B As a result of step S140, the band region BD1 of the medium 30 is recorded by the ejection of C ink from the nozzle group 22C, which is the forward scan of the first main scan; the ejection of M ink from the nozzle group 22M, which is the return scan of the second main scan; the ejection of Y ink from the nozzle group 22Y, which is the forward scan of the third main scan; and the ejection of K ink based on the nozzle range 21K3 of the same third main scan. On the other hand, the band region BD2 of the medium 30 is recorded by the ejection of C ink from the nozzle group 22C, which is the return scan of the second main scan; the ejection of M ink from the nozzle group 22M, which is the forward scan of the third main scan; the ejection of K ink based on the nozzle range 21K3 of the return scan of the fourth main scan; and the ejection of Y ink from the nozzle group 22Y, which is the same fourth main scan.

[0066] exist Figure 5BIn the example, only the nozzles 20 in nozzle range 21K3 of the non-colored nozzle group 21 eject K ink corresponding to the K recorded data. The ejection order of each color ink in band regions BD1 and BD3 recorded by forward scan, retrace scan, and forward scan is C, M, Y, K; the ejection order of each color ink in band regions BD2 and BD4 recorded by retrace scan, forward scan, and retrace scan is C, M, K, Y. That is, in the odd-numbered band region and the even-numbered band region, the ejection order of Y ink and K ink is reversed.

[0067] Therefore, in Figure 5B In the example, it is difficult to completely eliminate the color inversion unevenness that occurs between the odd-numbered and even-numbered band regions. However, in image IM4, Y ink is the first colored ink with the lowest ejection proportion among the colored inks, and its impact on the hue of the recorded result is smaller than that of other colored inks. Therefore, even if the ejection order of the first colored ink and K is reversed between the band regions, the degree of visually identifiable inversion unevenness can be reduced compared to the case where the ejection order of other colored inks and K is reversed between the band regions. It should be noted that in Figure 5B Or as will be discussed later Figure 7 In the meantime, it is easy to judge that there may be color inversion unevenness between the band areas of medium 30, but in reality, such obvious unevenness will not occur.

[0068] 5. Summary:

[0069] Thus, according to this embodiment, the recording device 10 includes: a recording head 19 having a plurality of nozzle groups having a plurality of nozzles 20 arranged in a first direction capable of ejecting liquid to a medium 30; a transport unit 17 for transporting the medium 30; and a control unit 11 for controlling the movement of the recording head 19 and the ejection of liquid by the recording head 19. The recording head 19, as a plurality of nozzle groups, includes: a first nozzle group having a plurality of first nozzles ejecting colorless liquid; and a plurality of second nozzle groups having a plurality of second nozzles ejecting colored liquid, wherein the plurality of second nozzle groups eject mutually different colored liquids, the plurality of second nozzle groups being arranged along the first direction, and the first nozzle groups and second nozzle groups being arranged along a second direction intersecting the first direction. The control unit 11 records an image by performing multiple main scans on the band area of ​​the medium 30, namely, a main scan (outgoing scan) in which the recording head 19 ejects liquid as it moves forward along the second direction, a sub-scan (relative scan) in which the recording head 19 moves relative to the medium 30 in the first direction, and a return scan (back scan) in which the recording head 19 ejects liquid as it moves back along the second direction. In this case, the control unit 11 performs the following first recording control: when, for a second nozzle group corresponding to the first colored liquid with the lowest ejection ratio for recording an image among a plurality of colored liquids, the range of the first nozzles adjacent to the first nozzles in the second direction in the first nozzle group is defined as the first range, and for a second nozzle group corresponding to a colored liquid other than the first colored liquid among a plurality of colored liquids, the range of the first nozzles adjacent to the first nozzles in the second direction in the first nozzle group is defined as the second range, the ejection ratio of the achromatic liquid used for recording the image in the first range is higher than the ejection ratio of the achromatic liquid in any second range used for recording the image.

[0070] According to the first recording control, the ejection ratio of the achromatic liquid in a first range used for recording the image is higher than the ejection ratio of the achromatic liquid in any second range used for recording the image. Therefore, it is possible to suppress color inversion unevenness between band regions.

[0071] Furthermore, according to this embodiment, the control unit 11 limits the first nozzle that sprays colorless liquid for recording images to a first range in the first recording control. That is, the spraying ratio of colorless liquid in the second range is set to 0.

[0072] Based on this configuration, the ink ejection sequence easily becomes uniform across all zones, thus suppressing or eliminating color inversion unevenness between zones. Furthermore, the ejection of achromatic liquid is performed only within the first zone, allowing for the completion of achromatic liquid ejection for one zone in a single main scan. Consequently, image quality degradation caused by offsets in the liquid droplet position during the outgoing and returning scans, or paper feed errors, can be avoided in the zone, particularly preventing degradation of text or lines recorded using large amounts of K ink.

[0073] It should be noted that, based on the comparison results of the colored emission ratios, there may be multiple colored areas with the lowest emission ratios. For example, if, regarding a certain band of image, the emission ratios of C and M are the same and the lowest, the allocation determination unit 12c only needs to conveniently determine either C or M as the first colored area for that band of image in step S120 and proceed to step S130. However, when there are consecutive bands of the same hue in the image, if, for a certain band area, one of the colored areas with the same and lowest emission ratio is determined as the first colored area, it is preferable to determine the same colored area as the first colored area in other band areas as well.

[0074] According to this embodiment, as an example, the colored nozzle group 21 is composed of second nozzle groups corresponding to an odd number of colored elements, each with three or more colors. Figure 2 The colored liquid is CMY ink in three colors. In addition, the colored liquid sprayed by the colored nozzle assembly 21 can be, for example, five colors obtained by adding light cyan ink and light magenta ink to CMY ink.

[0075] So far, the explanation has mainly focused on the case where the first nozzle that sprays colorless liquid for recording images is limited to a first range in the first recording control. However, the control unit 11 may also not prohibit the spraying of colorless liquid from the first nozzle in a second range. That is, in step S130, the allocation determination unit 12c can determine the allocation destination of the K recording data as the first range corresponding to the first colored position and the second range corresponding to the colored positions other than the first colored position.

[0076] For example, let Y be the first colored element of a certain band image. In this case, for the band image, the nozzle range 21K3 adjacent to the nozzle group 22Y in the colorless nozzle group 21 is the first range, and the nozzle ranges 21K1 and 21K2 are the second ranges. Therefore, the allocation decision unit 12c decides to allocate a predetermined proportion of pixels in the K-recorded data of the band image to the nozzle range 21K3, which is the first range, and to allocate the remaining pixels in the K-recorded data other than the predetermined proportion of pixels to the nozzle ranges 21K1 and / or 21K2, which are the second ranges, and proceeds to step S140. The predetermined proportion referred to here means a proportion that is at least more than half, but for the sake of the spirit of this embodiment, it can be considered as a proportion that is not 100% but is close to 100% to some extent. For example, 90% of the pixels in the K-recorded data with the image are allocated to the nozzle range 21K3 as the first range, and the remaining 10% of the pixels are allocated to either the nozzle range 21K1 or the nozzle range 21K2 as the second range, or half of each is allocated to the nozzle range 21K1 and the nozzle range 21K2.

[0077] This embodiment is not limited to a device or system, and discloses inventions of various types, such as methods executed by a device or system and programs 12 that cause a processor to execute methods.

[0078] For example, a recording method of a recording device 10, the recording device 10 having: a recording head 19 having a plurality of nozzles 20 arranged in a first direction for spraying liquid onto a medium 30; and a conveying unit 17 for conveying the medium 30, the recording method of the recording device 10 having the following recording steps: the recording head 19 as a plurality of nozzles having: a first nozzle group having a plurality of first nozzles for spraying colorless liquid; and a plurality of second nozzle groups having a plurality of second nozzles for spraying colored liquid, the plurality of second nozzle groups spraying different colored liquids from each other, the plurality of second nozzle groups being arranged along the first direction, the first nozzle groups and the second nozzle groups being arranged along a second direction intersecting the first direction, and recording being performed by controlling the movement of the recording head 19 and the spraying of liquid by the recording head 19. In the recording process, an image is recorded by performing multiple main scans on the strip area of ​​the medium 30, namely, a forward scan (where the recording head 19 ejects liquid as it moves forward in the second direction), a sub-scan (where the recording head 19 moves relative to the medium 30 in the first direction), and a return scan (where the recording head 19 ejects liquid as it moves back in the second direction). In this case, when the range of the first nozzles adjacent to the first nozzles in the second direction in the first nozzle group is defined as the first range for the second group of colored liquids corresponding to the first colored liquid with the lowest ejection ratio for recording the image, and the range of the first nozzles adjacent to the first nozzles in the second direction in the first nozzle group is defined as the second range for the second group of colored liquids corresponding to colored liquids other than the first colored liquid, the ejection ratio of the achromatic liquid used for recording the image in the first range is higher than the ejection ratio of the achromatic liquid used for recording the image in any second range.

[0079] 6. Variation example:

[0080] This section describes the variations included in this embodiment. Combinations of these variations are also included in this embodiment.

[0081] First variation:

[0082] In an image, when the proportions of multiple colored ejections are almost identical, the effect of suppressing color inversion unevenness remains almost unchanged regardless of whether the allocation destination of the K-recorded data is set to the first range or conversely, the second range. That is, when the difference in the proportions of colored ejections is small, performing the first recording control is not very meaningful. In view of this situation, as a first variation, the control unit 11 may perform the first recording control when the difference in the proportions of multiple colored liquids related to image recording exceeds a predetermined threshold, and when the difference is below the threshold, perform the following "second recording control": In the ejection of the colorless liquid used for recording the image, the range constituting the first nozzle group, adjacent to the multiple second nozzle groups in the second direction, is used on the upstream side of the sub-scanning direction in which the medium 30 is displaced relative to the recording head 19 by the sub-scan. Figure 2 In the configuration, the transport direction D1 is the sub-scanning direction of the displacement of the medium 30 relative to the recording head 19.

[0083] Figure 6 The flowchart illustrates a variation of the record control processing performed by control unit 11 according to procedure 12. Regarding... Figure 6 Appropriately omitting and Figure 3 The flowchart is a common description. In step S115 after step S110, the recording mode determination unit 12a determines whether to execute the first recording control or the second recording control. If the first recording control should be executed, the process proceeds from the "yes" determination to step S120. On the other hand, if the second recording control should be executed, the process proceeds from the "no" determination to step S135. As described above, steps S120, S130, and the subsequent step S140 constitute the first recording control. On the other hand, steps S135 and the subsequent step S140 correspond to the second recording control.

[0084] The first recording control can also be referred to as the first recording mode, and the second recording control as the second recording mode. Therefore, it can be said that the recording mode determination unit 12a determines and selects the recording mode to be executed in step S115. In step S115, the recording mode determination unit 12a determines, based on the recorded data, whether the difference in the spray ratios of multiple colored liquids exceeds a predetermined threshold. Specifically, it determines whether the difference in the spray ratios of the colored liquid with the highest spray ratio and the colored liquid with the lowest spray ratio among the multiple colored liquids exceeds a threshold. If this difference exceeds the threshold, it is determined that the first recording control should be executed, and the process proceeds to step S120. On the other hand, if the difference is below the threshold, it is determined that the second recording control should be executed, and the process proceeds to step S135.

[0085] The threshold setting used in step S115 can vary. For example, it could be set to threshold = 9%, with the CMYK emission ratios in the image being C = 40%, M = 35%, Y = 40%, and K = 20%. In this case, the difference of 5% between the emission ratio of C or Y (40%) and the emission ratio of M (35%) is below the threshold, therefore a "no" determination is made in step S115, and the second recording control is performed. According to the description so far, the determination in step S115 is also performed per image band. That is, recording is performed per image band using either the first recording control or the second recording control. However, the determination result in step S115 is the same for regions with the same hue in the image, therefore the first recording control or the second recording control can be performed in the same manner.

[0086] In step S135, the allocation determination unit 12c determines the range within the colorless nozzle group 21, which is set as the allocation destination for the K-recorded data, as the range upstream of the sub-scanning direction among the multiple nozzle ranges 21K1, 21K2, and 21K3 of the colorless nozzle group 21, that is, according to... Figure 2 The example is nozzle range 21K1. Hereinafter, nozzle range 21K1 will also be referred to as the "upstream range".

[0087] Figure 7 This diagram illustrates the process of recording image IM5 onto medium 30 via second recording control and based on recording data, and shows a portion of recording head 19 and medium 30. Image IM5 is a uniform, patternless image among multiple tape images, with the CMYK ink ejection ratios specified in the recording data being C=40%, M=35%, Y=40%, and K=20%. The difference in the ejection ratios of the colored inks in this image IM5 is small, therefore, in step S115, "No," i.e., second recording control, is selected regarding each tape image. Therefore, when recording image IM5, in step S135, the nozzle range 21K1, which is the upstream range, is determined as the destination for the K recording data allocation for each tape image.

[0088] According to this Figure 7As a result of step S140 following step S135, the band region BD1 of the medium 30 is recorded by ejection of C ink from the nozzle group 22C (as the forward scan of the first main scan), K ink from the nozzle range 21K1 of the same first main scan, M ink from the nozzle group 22M (as the return scan of the second main scan), and Y ink from the nozzle group 22Y (as the forward scan of the third main scan). On the other hand, the band region BD2 of the medium 30 is recorded by ejection of K ink from the nozzle range 21K1 (as the return scan of the second main scan), C ink from the nozzle group 22C of the same second main scan, M ink from the nozzle group 22M (as the forward scan of the third main scan), and Y ink from the nozzle group 22Y (as the return scan of the fourth main scan).

[0089] exist Figure 7 In the example, only nozzles 20 within nozzle range 21K1 eject K ink corresponding to the K recorded data. The ejection order of each color ink in band regions BD1 and BD3 recorded by forward scan, retrace scan, and forward scan is C, K, M, Y; the ejection order of each color ink in band regions BD2 and BD4 recorded by retrace scan, forward scan, and retrace scan is K, C, M, Y. That is, in the odd-numbered and even-numbered band regions, the ejection order of C ink is reversed compared to K ink. Therefore, it is difficult to completely eliminate the... Figure 7 The uneven color reversal that occurs between the odd-numbered and even-numbered band regions is generated.

[0090] However, according to the second recording control, by setting the destination of the K-recording data allocation to the upstream range, a different advantage arises compared to the first recording control. Specifically, by setting the destination of the K-recording data allocation to the upstream range, K ink can be ejected from each band area in the fastest possible sequence. This minimizes the penetration of achromatic ink caused by overlapping with colored ink during ejection, and stabilizes the achromatic ink in each band area. In particular, it prevents the degradation of the quality of text and lines recorded using large amounts of achromatic ink. Thus, according to the first variation, if the effect of the first recording control is easily obtained, the first recording control can be executed; if the effect of the first recording control is difficult to obtain, the second recording control can be executed to enjoy its effect.

[0091] The first variation is further explained.

[0092] Even if the difference in the ejection ratios of multiple colored liquids is below a threshold, if the ejection ratio of the colored liquid with the lowest ejection ratio is 0%, the recording mode determination unit 12a can exceptionally determine in step S115 that the first recording control should be executed and proceed to step S120. For example, in an image, there is a case where the ejection ratios of CMYK are C=7%, M=5%, Y=0%, and K=30%. In this case, the difference between the ejection ratio of C (7%) and the ejection ratio of Y (0%) is 7% below the threshold. However, if K recording data is allocated in the nozzle range 21K3 adjacent to the nozzle group 22Y corresponding to Y, the ink ejection order in each zone is C, M, K, thus reliably achieving the effect of the first recording control.

[0093] Second variation:

[0094] When the recording medium 30 is of a type where the liquid is easily permeable, color inversion unevenness is easily noticeable; conversely, when the liquid is of a type where it is difficult to permeate, color inversion unevenness is not very noticeable. Therefore, as a second variation, the control unit 11 may perform first recording control when the type of the medium 30 is a type where the liquid is more easily permeable than a predetermined reference, and perform second recording control when the type of the medium 30 is a type where the liquid is less permeable than the reference: in the ejection of the colorless liquid used for recording the image, the range upstream of the sub-scanning direction in which the medium 30 is displaced relative to the recording head 19 by the sub-scanning is used in a plurality of ranges that constitute the first nozzle group and are adjacent to the plurality of second nozzle groups in the second direction.

[0095] The second variation is also based on... Figure 6 The flowchart is used to illustrate this.

[0096] In step S115, the recording mode determination unit 12a determines which of the first recording control and the second recording control should be executed. If the first recording control should be executed, the process proceeds from the "yes" determination to step S120; if the second recording control should be executed, the process proceeds from the "no" determination to step S135. The first recording control and the second recording control are as already explained.

[0097] In the second variation, the recording mode determination unit 12a determines in step S115 whether the medium 30, which is the object of transport by the transport unit 17, belongs to the "first category," which is more easily permeated by liquids compared to a predetermined standard, or to the "second category," which is less easily permeated by liquids compared to the predetermined standard. Since the groups of media 30 corresponding to the first category and the groups of media 30 corresponding to the second category are predetermined, the recording mode determination unit 12a only needs to obtain the category of the medium 30, which is the object of transport by the transport unit 17, and determine whether the obtained category belongs to the first or second category. The method of obtaining the category of the medium 30 is not particularly limited. The recording mode determination unit 12a may obtain the category of the medium 30, for example, through input from the user via the operation receiving unit 14, or based on the detection signal of a media sensor (not shown) installed on the tray storing the medium 30 before transport and the transport path of the transport unit 17 to the medium 30.

[0098] If the media 30 is classified as a first category, the recording mode determination unit 12a determines that first recording control should be executed, and the process proceeds to step S120. On the other hand, if the media 30 is classified as a second category, it determines that second recording control should be executed, and the process proceeds to step S135. Thus, according to the second variation, if the effect of first recording control is easily obtained, first recording control can be executed; if the effect of first recording control is difficult to obtain, second recording control can be executed to enjoy the effect of second recording control.

[0099] The first modified example can also be combined with the second modified example. For example, if the type of medium 30 is the first type and the difference in the spray ratio of multiple colored liquids based on the recorded data exceeds a predetermined threshold, the recording mode determination unit 12a determines "yes" in step S115; if the type of medium 30 is the second type or the difference in the spray ratio of multiple colored liquids is below the threshold, it determines "no" in step S115.

[0100] Third variation:

[0101] In addition to reciprocating along the main scanning direction D2, the carriage 18 can also perform reciprocating movement along a sub-scanning direction that intersects the main scanning direction D2. The sub-scanning direction is the first direction. Up to now, the sub-scanning between main scans involves the transport unit 17 feeding the medium 30 downstream. However, it is also possible to perform the sub-scanning by moving the carriage 18 upstream in the transport direction D1 by a distance equal to the width of the tape between main scans. That is, it can also be configured such that the carriage 18 moves two-dimensionally in a plane parallel to the surface of the stationary medium 30 to complete the recording of multiple tape areas. After the transport unit 17 has performed the transport of multiple tape areas, the carriage 18 returns to its original position, and after the transport unit 17 has performed the transport of multiple tape areas, the recording of multiple tape areas is performed again by starting the two-dimensional movement of the carriage 18.

[0102] Furthermore, in a configuration where the carriage 18 performs recording of multiple band regions by moving the stationary medium 30 in two dimensions along the main scanning direction and the sub-scanning direction, the transport direction of the medium 30 by the transport unit 17 may not be as described above. Figure 2 Instead of the direction D1 shown, it is an orientation parallel to the main scanning direction D2.

Claims

1. A recording device, characterized in that, have: A recording head having multiple nozzle groups, wherein the nozzle groups are configured in a first direction with multiple nozzles capable of ejecting liquid into a medium; The conveying unit conveys the medium; and The control unit controls the movement of the recording head and the ejection of liquid by the recording head. The recording head, as a plurality of the nozzle groups, has: The first nozzle group is configured with multiple first nozzles that eject a colorless liquid; and Multiple second nozzle groups are configured with multiple second nozzles that spray colored liquids, and the multiple second nozzle groups spray different colored liquids from each other. Multiple second nozzle groups are arranged along the first direction. The first nozzle group and the second nozzle group are configured along a second direction that intersects the first direction. The control unit When recording an image by performing multiple main scans on the band area of ​​the medium, namely, a forward scan (where the recording head ejects liquid as it moves forward along the second direction), a sub-scan (where the recording head moves relative to the medium in the first direction), and a return scan (where the recording head ejects liquid as it moves back along the second direction), the following first recording control is performed: When the range of the first nozzles adjacent in the second direction in the first nozzle group is defined as the first range for the second nozzle group corresponding to the first colored liquid with the lowest ejection ratio for recording the image among the plurality of colored liquids, and the range of the first nozzles adjacent in the second direction in the first nozzle group is defined as the second range for the second nozzle group corresponding to the second nozzle group corresponding to the colored liquid other than the first colored liquid among the plurality of colored liquids, the range of the first nozzles adjacent in the second direction in the first nozzle group is defined as the second range. The ejection ratio of the colorless liquid used for recording the image in the first range is higher than the ejection ratio of the colorless liquid used for recording the image in any of the second ranges.

2. The recording device according to claim 1, characterized in that, The control unit The first recording control is performed if the difference in the ejection ratios of multiple colored liquids associated with the recording of the image exceeds a predetermined threshold. If the difference is below the threshold, the following second recording control is performed: The ejection of the colorless liquid used to record the image utilizes a range of the medium, which is located upstream of the sub-scan direction relative to the recording head displacement, in one of a plurality of ranges that constitute the first nozzle group and are adjacent to a plurality of second nozzle groups in the second direction.

3. The recording device according to claim 1 or claim 2, characterized in that, The control unit The first recording control is performed when the category of the medium is one that is more permeable to liquids compared to a specified reference. If the type of medium is one that is less permeable to liquids compared to the reference, the following second recording control is performed: The ejection of the colorless liquid used to record the image utilizes a range of the medium, which is located upstream of the sub-scan direction relative to the recording head displacement, in one of a plurality of ranges that constitute the first nozzle group and are adjacent to a plurality of second nozzle groups in the second direction.

4. The recording device according to claim 1, characterized in that, In the first recording control, the control unit limits the first nozzle that sprays the colorless liquid for recording the image to the first range.

5. A recording method of a recording device, characterized in that, The recording device includes: a recording head having a plurality of nozzle groups, the nozzle groups being arranged in a first direction with a plurality of nozzles capable of ejecting liquid into a medium; and a conveying unit for conveying the medium. The recording head, as a plurality of the nozzle groups, has: The first nozzle group is configured with multiple first nozzles that eject a colorless liquid; and Multiple second nozzle groups are configured with multiple second nozzles that spray colored liquids, and the multiple second nozzle groups spray different colored liquids from each other. Multiple second nozzle groups are arranged along the first direction. The first nozzle group and the second nozzle group are configured along a second direction that intersects the first direction. The recording method includes a recording step of controlling the movement of the recording head and recording the liquid ejected by the recording head. In the recording process, In the case of recording an image by performing multiple main scans on the band area of ​​the medium, namely, a primary scan (outgoing scan) in which the recording head ejects liquid as it moves forward along the second direction, a secondary scan (relative scan) in which the recording head moves relative to the medium in the first direction, and a retrace scan (return scan) in which the recording head ejects liquid as it moves back along the second direction, the main scan is performed on the band area of ​​the medium. When the range of the first nozzles adjacent in the second direction in the first nozzle group is defined as the first range for the second nozzle group corresponding to the first colored liquid with the lowest ejection ratio for recording the image among the plurality of colored liquids, and the range of the first nozzles adjacent in the second direction in the first nozzle group is defined as the second range for the second nozzle group corresponding to the second nozzle group corresponding to the colored liquid other than the first colored liquid among the plurality of colored liquids, the range of the first nozzles adjacent in the second direction in the first nozzle group is defined as the second range. The ejection ratio of the colorless liquid used for recording the image in the first range is higher than the ejection ratio of the colorless liquid used for recording the image in any of the second ranges.

Images