JP2015182237A - Ink jet recording method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ink jet recording method by which image quality degradation is prevented and an image of appropriate image quality can be recorded.SOLUTION: In an ink jet recording method, an ink jet head is used that includes: a first nozzle array in which a plurality of first nozzles for emitting ink are arranged in a first direction at a first interval corresponding to a nozzle density of 100 npi or higher; and a second nozzle array in which a plurality of second nozzles for emitting ink are arranged in the first direction at the first interval. The first nozzle array and the second nozzle array are adjacent to each other in a second direction orthogonal to the first direction at a second interval not shorter than the first interval. The ink jet recording method is for recording an image on a recording medium by emitting ink droplets by using the ink jet head. In the method, emission of ink from the first nozzle array is controlled on the basis of a third interval between the emission face of the ink jet head and the recording side of the recording medium.

Description

  The present invention relates to an ink jet recording method.

  Technologies related to inkjet have been proposed. For example, Patent Document 1 discloses an ink jet recording apparatus. In this ink jet recording apparatus, a plurality of types of ink are classified into at least two ink groups, and inks belonging to different ink groups are alternately arranged in adjacent nozzle rows in the recording head. Patent Document 2 discloses an ink jet recording apparatus. In this ink jet recording apparatus, the head of the printing unit has a nozzle row in which a plurality of nozzles are arranged in a straight line over a length corresponding to the entire width of the recording paper in a direction substantially orthogonal to the feeding direction of the recording paper. Nozzles are arranged at a nozzle density of 300 (300 npi) or more per inch. The applicant has proposed a technique relating to an ink jet recording method in Patent Document 3.

JP 2011-46061 A JP 2005-313626 A JP 2012-87504 A

  The ink jet recording apparatus can record an image on a recording medium with high quality. Therefore, the ink jet recording apparatus is used not only for home use but also in the industrial field. When the inventor increases the nozzle density with an inkjet head and narrows the interval between adjacent nozzles, when the ink is continuously ejected from each nozzle and an image is recorded, the landing position of the ejected ink deviates from the target position. As a result, it has been recognized that the image quality may deteriorate. The inventor has recognized that the higher the drive frequency and the shorter the ink ejection interval, the lower the image quality. Furthermore, the inventor has recognized that the image quality decreases as the distance between the ejection surface on which the nozzle is formed by the inkjet head and the recording surface of the recording medium increases. For example, when a recording medium having a variation in thickness or a protrusion on the recording surface is targeted, the interval between the ejection surface and the recording surface is increased in order to prevent contact between the ejection surface and the recording medium. For example, when the recording medium is a fluffy fabric, the interval between the ejection surface and the recording surface may be set to several mm to 10 mm or more.

  An object of the present invention is to provide an ink jet recording method capable of suppressing a decrease in image quality and recording an image having a suitable image quality.

  According to an aspect of the present invention, a first nozzle row that is aligned in a first direction at a first interval in which a nozzle density of a plurality of first nozzles that eject ink is 100 npi (nozzles per inch) or more, and ejects ink. A plurality of second nozzles includes a second nozzle row aligned in the first direction at the first interval, and the first nozzle row and the second nozzle row are a second interval greater than or equal to the first interval. An inkjet recording method for recording an image on a recording medium by ejecting ink droplets using an inkjet head provided adjacent to a second direction orthogonal to the first direction, wherein the inkjet head And an ink jet recording method for controlling ink ejection from the first nozzle row based on a third interval between the ejection surface of the recording medium and the recording surface of the recording medium.

  According to this, it is possible to suppress the landing position deviation of the ejected ink. Along with this, it is possible to land the ink on the target position with high accuracy. As a result of examining the above-described problems, the inventor has reached the following idea. That is, an air flow wall corresponding to this nozzle row may be formed by the ink ejected simultaneously or at the same timing from each nozzle forming a predetermined one nozzle row. A plurality of walls of the airflow are formed corresponding to each of the plurality of nozzle rows. Furthermore, for example, a vortex may be generated in a region partitioned by an air flow wall of each nozzle row by a predetermined operation during image recording. The ejected ink is considered to be affected by the vortex generated in the vicinity of the nozzle that ejected the ink during the flight. The influence of the vortex generated between the walls of the airflow is more easily received as the ink droplet amount is smaller, and the affected ink is caused to flow in different directions and land at a position shifted from the target position. In this regard, by controlling the ejection of ink from the first nozzle row based on the third distance between the ejection surface of the inkjet head and the recording surface of the recording medium, the formation of air current walls and the generation of eddy currents are prevented. It is possible to suppress the ink, and the ejected ink can be smoothly ejected.

  In this ink jet recording method, the third interval may be 3 mm or more. According to this, it is possible to record an image on the recording surface while preventing the recording medium from coming into contact with the ejection surface.

  In this ink jet recording method, the volume of the ejected ink droplet may be 45 picoliters (pl) or more. According to this, when the volume of the ink droplet is such, it is possible to obtain an image having a more suitable image quality. The upper limit of the volume of the ink droplet is set to about 220 picoliters (pl) in consideration of the image quality required for the recorded image.

  ADVANTAGE OF THE INVENTION According to this invention, the inkjet recording method which can suppress the fall of image quality and can record the image of suitable image quality can be obtained.

1 is a perspective view illustrating a schematic configuration of an ink jet recording apparatus. It is the figure which looked at the inkjet head from the discharge surface side in which the nozzle was formed. It is a figure which shows the pattern of the use nozzle in each nozzle density. 3 is a photograph showing image quality criteria.

  Embodiments for carrying out the present invention will be described with reference to the drawings. The present invention is not limited to the configurations described below, and various configurations can be employed in the same technical idea. For example, some of the configurations shown below may be omitted or replaced with other configurations. Other configurations may be included.

<Inkjet recording apparatus>
The ink jet recording apparatus 10 will be described with reference to FIGS. 1 and 2. In the inkjet recording apparatus 10, the recording medium 14 is conveyed and an image is recorded on the recording surface 15 of the recording medium 14. In the ink jet recording apparatus 10, images are recorded on various recording media 14. Examples of the recording medium 14 include fabrics and building materials. In the present embodiment, a case where the recording medium 14 is a long fabric will be described as an example. The ink colors used for image recording are four colors, black, magenta, yellow, and cyan. The ink color may be a color other than these. The number of ink colors may be 3 colors or less or 5 colors or more. The halftone dot pattern attached to the portion of the recording medium 14 illustrated on the downstream side in the transport direction in FIG. 1 corresponds to the image recorded on the recording medium 14.

  As shown in FIG. 1, the ink jet recording apparatus 10 includes a transport unit 20, a recording unit 30, a moving unit 40, and main tanks 50K, 50M, 50Y, and 50C. The transport unit 20 transports the recording medium 14 placed on the transport surface 21 along the longitudinal direction of the recording medium 14. That is, the transport unit 20 including the transport surface 21 has a side surface as a mounting unit including a mounting surface on which the recording medium 14 on which an image is recorded is placed.

  In the present embodiment, the direction in which the recording medium 14 is transported by the transport unit 20 is referred to as “transport direction”. The transport direction is a direction along the longitudinal direction of the recording medium 14 and is a direction orthogonal to the short direction of the recording medium 14. The short direction of the recording medium 14 is the width direction of the recording medium 14 and coincides with the direction (main scanning direction) in which the recording unit 30 is reciprocated by the moving unit 40 as described later. In the present embodiment, the transport direction and the opposite direction are referred to as “longitudinal direction” in accordance with the longitudinal direction of the recording medium 14. The conveyance direction and the opposite direction may be referred to as “sub-scanning direction” with respect to the main scanning direction described above. The direction orthogonal to each of the transport direction and the opposite direction is referred to as the “short direction” according to the short direction of the recording medium 14.

  The recording unit 30 includes inkjet heads 31K, 31M, 31Y, 31C and a carriage 34. The inkjet head 31K is an inkjet head that ejects black ink and records an image with the black ink. A plurality of nozzles 32 for discharging black ink are formed in the inkjet head 31K (see FIG. 2). The inkjet head 31M is an inkjet head that discharges magenta ink and records an image with the magenta ink. A plurality of nozzles 32 that eject magenta ink are formed in the inkjet head 31M (see FIG. 2).

  The inkjet head 31Y is an inkjet head that discharges yellow ink and records an image with the yellow ink. A plurality of nozzles 32 for discharging yellow ink are formed on the inkjet head 31Y (see FIG. 2). The ink jet head 31C is an ink jet head that discharges cyan ink and records an image with the cyan ink. A plurality of nozzles 32 that discharge cyan ink are formed in the inkjet head 31C (see FIG. 2). The inkjet heads 31K, 31M, 31Y, and 31C have the same configuration. The inkjet heads 31K, 31M, 31Y, and 31C may be formed by arranging a plurality of head units in the longitudinal direction, or in the longitudinal direction and the lateral direction.

  In each of the inkjet heads 31K, 31M, 31Y, and 31C, the plurality of nozzles 32 are classified into a plurality of first nozzles 321 and a plurality of second nozzles 322 (see FIG. 2). The first nozzle 321 and the second nozzle 322 are nozzles having the same diameter. In each of the inkjet heads 31K, 31M, 31Y, and 31C, the plurality of first nozzles 321 and the plurality of second nozzles 322 are arranged in a staggered manner. The plurality of first nozzles 321 are aligned in the first direction at a first interval W1 with a nozzle density of 100 npi or more to form a first nozzle row LA. The plurality of second nozzles 322 are aligned in the first direction at the first interval W1 to form the second nozzle row LB. In the ink jet recording apparatus 10 that records an image by reciprocating the recording unit 30 in the lateral direction, the “first direction” is the longitudinal direction.

  In this embodiment, in each of the inkjet heads 31K, 31M, 31Y, and 31C, the plurality of nozzles 32 are classified into a first nozzle 321 and a second nozzle 322, and each of the inkjet heads 31K, 31M, 31Y, and 31C is A configuration in which two nozzle rows are formed will be described as an example. The nozzle rows respectively formed on the inkjet heads 31K, 31M, 31Y, and 31C may be classified into three or more by dividing the plurality of nozzles 32 into three or more. In the present embodiment, the “nozzle 32” does not distinguish between the first nozzle 321 and the second nozzle 322, or is a collective term for these. In FIG. 2, in each of the inkjet heads 31K, 31M, 31Y, and 31C, the number and arrangement of the plurality of nozzles 32 (the first nozzle 321 and the second nozzle 322) are illustrated in a simplified manner. In FIG. 2, the plurality of first nozzles 321 and the plurality of second nozzles 322 are not illustrated with a nozzle density of 100 npi or more as described above.

  In each of the inkjet heads 31K, 31M, 31Y, and 31C, the first nozzle array LA and the second nozzle array LB are provided adjacent to each other in the second direction at the second interval W2. When the plurality of first nozzles 321 and the plurality of second nozzles 322 are arranged in a staggered manner, the first nozzle row LA and the second nozzle row LB are in a positional relationship shifted by a predetermined amount in the first direction. The second direction is a direction orthogonal to the first direction. In the ink jet recording apparatus 10 that records an image by reciprocating the recording unit 30 in the short direction, the “first direction” is the longitudinal direction as described above. Therefore, the “second direction” is the short direction. In the following description, the first direction is the longitudinal direction and the second direction is the short direction.

  The first interval W1 is the distance between the centers of the nozzles 32 adjacent in the longitudinal direction, and the second interval W2 is the distance between the centers of the first nozzle row LA and the second nozzle row LB adjacent in the short direction. When the nozzle density is 100 npi, the first interval W1 is 0.254 mm (first interval W1 = 1 (inch) × 25.4 (mm) / 100). The second interval W2 is an interval equal to or greater than the first interval W1. Therefore, the second interval W2 is set to a range equal to or greater than the first interval W1 “0.254 mm” when the nozzle density is 100 npi. The second interval W2 is set in consideration of the influence of an airflow wall described later in addition to the number of nozzle rows. The state shown in FIG. 2 is a state where “second interval W2 = first interval W1”.

  Inkjet heads 31K, 31M, 31Y, and 31C are mounted on the carriage 34 in a state where they are positioned at predetermined positions. As shown in FIG. 1, the inkjet heads 31 </ b> K, 31 </ b> M, 31 </ b> Y, and 31 </ b> C are mounted on the carriage 34 while being adjacent to each other in the lateral direction. The arrangement order of the inkjet heads 31K, 31M, 31Y, and 31C may be different from that shown in FIG. These arrangement orders are appropriately determined in consideration of various conditions.

  The recording unit 30 is provided above the conveyance surface 21 of the conveyance unit 20. At this time, the third gap G3 (see FIG. 1) between the ejection surfaces 33 of the inkjet heads 31K, 31M, 31Y, and 31C and the recording surface 15 of the recording medium 14 is, for example, wider than 2 mm, specifically, 3 mm or more. Set to The third interval G3 is appropriately set in consideration of the variation in the thickness of the recording medium 14 and / or the state of the recording surface 15 (fluffing or the like). For example, in the case where a fabric having fuzz on the recording surface 15 becomes the recording medium 14, the third gap G3 may be 10 mm. However, the third gap G3 is about 20 mm at the maximum. The ejection surface 33 is each surface of the inkjet heads 31K, 31M, 31Y, 31C on which the nozzles 32 are formed. The ejection surfaces 33 of the inkjet heads 31K, 31M, 31Y, and 31C are included in the same virtual plane (horizontal plane). The recording medium 14 conveyed by the conveyance unit 20 passes through the recording unit 30 with the recording surface 15 facing the ejection surface 33 with a third gap G3.

  The moving unit 40 reciprocates the recording unit 30 in the short direction. As shown in FIG. 1, the moving unit 40 includes two pulleys 41 and 42 and a timing belt 43. The two pulleys 41 and 42 are provided on both sides in the lateral direction with respect to the transport unit 20. For example, a motor (not shown) is connected to the pulley 41, and the pulley 42 is rotatably supported. The pulley 41 rotates as the motor rotates. The timing belt 43 is stretched over pulleys 41 and 42 in a state where tension is applied. The recording unit 30 is attached to the timing belt 43 via a support unit 46 fixed to the carriage 34.

  When the inkjet recording apparatus 10 records an image, the motor connected to the pulley 41 reciprocally rotates clockwise and counterclockwise. As the motor rotates, the pulley 41 rotates back and forth on both the left and right sides (for the rotation direction of the pulley 41, see “arc-shaped arrow” shown inside the pulley 41 in FIG. 1). When the pulley 41 rotates counterclockwise by rotating the motor in a predetermined direction, the timing belt 43 also rotates counterclockwise. The pulley 42 rotates following the timing belt 43 that rotates counterclockwise. Accordingly, the recording unit 30 moves from the second side in the short direction to the first side. When the recording unit 30 reaches the first moving end in the short direction, the rotation direction of the motor is reversed and the pulley 41 rotates to the right. When the pulley 41 rotates to the right, the timing belt 43 also rotates to the right. The pulley 42 rotates following the timing belt 43 that rotates clockwise. Accordingly, the recording unit 30 moves from the first side in the lateral direction to the second side. When the recording unit 30 reaches the moving end on the second side in the short direction, the rotation direction of the motor is reversed again, and the pulley 41 rotates left again. The reciprocating movement of the recording unit 30 in the short direction by the moving unit 40 is repeated until the image recording is completed.

  The main tank 50K is a tank that stores black ink. The black ink flows out of the main tank 50K, flows through the supply tube 51K, and is supplied to the inkjet head 31K. The main tank 50M is a tank that stores magenta ink. The magenta ink flows out from the main tank 50M, flows through the supply tube 51M, and is supplied to the inkjet head 31M. The main tank 50Y is a tank that stores yellow ink. The yellow ink flows out of the main tank 50Y, flows through the supply tube 51Y, and is supplied to the inkjet head 31Y. The main tank 50C is a tank that stores cyan ink. The cyan ink flows out of the main tank 50C, flows through the supply tube 51C, and is supplied to the inkjet head 31C.

  In FIG. 1, the supply tubes 51K, 51M, 51Y, and 51C are simplified. The supply tubes 51K, 51M, 51Y, and 51C are provided in a state that can accommodate the reciprocating movement of the recording unit 30 in the short direction.

  In the inkjet recording apparatus 10, when an image is recorded on the recording medium 14 by reciprocating the recording unit 30 in the short direction, the recording medium 14 is conveyed in the conveying direction by the conveying unit 20. The conveyance of the recording medium 14 by the conveyance unit 20 is performed intermittently according to the movement of the recording unit 30 in the short direction. The inks of the respective colors are ejected toward the recording medium 14 from the nozzles 32 respectively formed on the inkjet heads 31K, 31M, 31Y, and 31C at a predetermined timing when the recording unit 30 moves in the short direction. The inks of the respective colors ejected from the nozzles 32 of the inkjet heads 31K, 31M, 31Y, 31C land on the recording surface 15 of the recording medium 14. An image is recorded on the recording surface 15 of the recording medium 14 by the landed ink of each color.

<Example>
An experiment was conducted to confirm the effectiveness of the ink jet recording method of the present embodiment. Hereinafter, the experimental method and the experimental result will be described with reference to FIGS. 3 to 4 and Tables 1 to 4.

<Experiment method>
In this experiment, similar to the above-described ink jet recording apparatus 10, an ink jet recording apparatus of a type in which an image is recorded by reciprocating a recording unit including an ink jet head was used. In the experiment, one color ink was ejected from one inkjet head, and a solid image of the one color was recorded on the recording surface of the recording medium. Coated paper was used as the recording medium. The conditions for inkjet recording were the following conditions (1) to (5).

(1) Distance between discharge surface and recording surface (third distance G3): 2, 3, 5, 10 mm
(2) Ink drop amount: 45, 90 pl / drop (3) Nozzle density of ink jet head (first interval W1): 100 npi
(4) Drive frequency: 1, 2, 3, 5, 10, 20 kHz
(5) Nozzle diameter: 50 μm
Regarding condition (3), in this experiment, an inkjet head having a nozzle density (first interval W1) of 100 npi and an interval between adjacent nozzle rows (second interval W2) of 100 npi was used.
Each nozzle density 100, 50, 33.3, and 25 npi in the table to be described later represents an interval between nozzles that actually eject ink in the same nozzle row.
The nozzle density of 100 npi in the table means a state in which ink is ejected from all nozzles in one nozzle row (see FIG. 3A), and the interval between nozzles that actually eject ink is 0. The nozzle density in the table is 50 npi. Ink is ejected from every other nozzle in one nozzle row, and the number of nozzles used is thinned out compared to the nozzle density of 100 npi in the table (FIG. 3 (b )), And the interval between nozzles that actually eject ink is 0.508 mm.
The nozzle density in the table is 33.3 npi. Ink is ejected from every two nozzles in one nozzle row, and the number of nozzles to be used is further reduced compared to the nozzle density of 50 npi in the table (FIG. 3C). The interval between nozzles that actually eject ink is 0.762 mm.
The nozzle density of 25 npi in the table means that ink is ejected from every three nozzles in one nozzle row, and the number of nozzles to be used is further reduced compared to the nozzle density of 33.3 npi in the table (FIG. 3D). The interval between nozzles that actually eject ink is 1.016 mm.
In the ink jet head used in the experiment, a plurality of nozzle rows (4 rows in FIG. 3) are formed. In the case of nozzle density 50, 33.3, 25 in the table, the other nozzle rows are used. Ink is ejected from the nozzles in a similar pattern, and the total amount of ink ejected is the same as when the nozzle density is 100 npi.

  The image quality of the recorded image was classified into three levels: good (judgment result: ◯), slightly bad (judgment result: Δ), and bad (judgment result: x). When a printed pattern was not recognized in the recorded image, the determination result was “good (◯)” (see “image quality: good” in FIG. 4). If the recorded image has a slight wind pattern, the determination result is “slightly bad (Δ)” (see “image quality: slightly bad” in FIG. 4). When a wind pattern is clearly recognized in the recorded image, the determination result is “defective (×)” (see “image quality: defective” in FIG. 4).

<Experimental result 1>
Table 1 shows an experimental result 1 when the interval between the ejection surface and the recording surface (refer to “third interval G3” in FIG. 1 is referred to as “third interval G3” as described above) is 2 mm. When the third gap G3 was 2 mm, no printed pattern was observed in the recorded image and the image quality was good regardless of the nozzle density, the appropriate amount of ink, and the drive frequency.

<Experimental result 2>
Table 2 shows the experimental result 2 when the third gap G3 is 3 mm. When the third gap G3 was 3 mm, a wind pattern was confirmed at each nozzle density of 100 npi, 50 npi, and 33.3 npi, and a decrease in image quality was observed. In the case of 100 npi, when the driving frequency was 2 kHz or higher, the image quality was lowered to “bad”. This was the same for both ink drops of 45 pl and 90 pl.

  At 50 npi, when the ink droplet amount was 45 pl and the driving frequency was 3 kHz or higher, or when the ink droplet amount was 90 pl and the driving frequency was 10 kHz or higher, the image quality was lowered to “slightly poor”. At 33.3 npi, when the ink droplet amount was 45 pl and the driving frequency was 10 kHz or more, the image quality was lowered to “slightly poor”.

On the other hand, when the nozzle density was 25 npi, no printed pattern was observed in the recorded image regardless of the ink droplet amount and the driving frequency, and the image quality was good.

<Experimental result 3>
Table 3 shows the experimental result 3 when the third gap G3 is 5 mm. When the third gap G3 was 5 mm, a wind pattern was confirmed at each nozzle density of 100 npi, 50 npi, and 33.3 npi, and a decrease in image quality was observed. At 100 npi, when the drive frequency was 2 kHz or higher, the image quality was reduced to “bad”. This was the same for both ink drops of 45 pl and 90 pl.

  At 50 npi, when the ink droplet amount was 45 pl and the driving frequency was 2 kHz or higher, or when the ink droplet amount was 90 pl and the driving frequency was 3 kHz or higher, the image quality was lowered to “bad”. When the ink droplet amount was 90 pl and the drive frequency was 2 kHz, the image quality was lowered to “slightly poor”.

  At 33.3 npi, when the ink droplet amount was 45 pl and the driving frequency was 3 kHz and 5 kHz, the image quality was lowered to “slightly poor”, and when it was 10 kHz or higher, it was lowered to “bad”. When the ink droplet amount was 90 pl and the drive frequency was 10 kHz or more, the image quality was lowered to “slightly poor”.

On the other hand, when the nozzle density was 25 npi, no printed pattern was observed in the recorded image regardless of the ink droplet amount and the driving frequency, and the image quality was good.

<Experimental result 4>
Table 4 shows the experimental results 4 when the third gap G3 is 10 mm. When the third gap G3 was 10 mm, a wind pattern was confirmed at each nozzle density of 100 npi, 50 npi, and 33.3 npi, and a decrease in image quality was observed. At 100 npi, when the drive frequency was 2 kHz or higher, the image quality was reduced to “bad”. This was the same for both ink drops of 45 pl and 90 pl.

  At 50 npi, when the ink droplet amount was 45 pl and the driving frequency was 2 kHz or higher, or when the ink droplet amount was 90 pl and the driving frequency was 3 kHz or higher, the image quality was lowered to “bad”. When the ink droplet amount was 90 pl and the drive frequency was 2 kHz, the image quality was lowered to “slightly poor”.

  At 33.3 npi, when the ink droplet amount was 45 pl and the driving frequency was 2 kHz, the image quality was lowered to “slightly poor”, and when it was 3 kHz or more, it was lowered to “bad”. When the ink droplet amount was 90 pl and the drive frequency was 3 kHz or more, the image quality was lowered to “bad”.

On the other hand, when the nozzle density was 25 npi, no printed pattern was observed in the recorded image regardless of the ink droplet amount and the driving frequency, and the image quality was good.

<Discussion>
Wind ripples are thought to be caused by airflow walls. The wall of the air flow is formed corresponding to each nozzle row by ink ejected simultaneously or at the same timing from each nozzle forming a predetermined one nozzle row. When there are a plurality of nozzle rows, a plurality of air flow walls are formed corresponding to each of the plurality of nozzle rows. Further, for example, a predetermined operation during image recording, such as conveyance of the recording medium and / or reciprocating movement of the recording unit, generates vortex in the region partitioned by the air flow walls of each nozzle row. The ejected ink is affected by, for example, the vortex generated near the nozzle that ejected the ink. As is clear from the above results, wind ripples are more likely to occur as the nozzle density is increased, the drive frequency is increased, and the third interval G3 is increased. When the third gap G3 was set to 3 mm or more, deterioration in image quality was recognized depending on conditions (see Tables 2 to 4). However, when the interval between the nozzles used is sufficiently large (for example, the nozzle density is set to 25 npi), good image quality is realized even when the third interval G3 is set to 3 mm or more.

<Modification>
This embodiment can also be performed as follows. Some configurations of the modifications shown below can be appropriately combined and employed. Effects similar to those described above can also be obtained by an ink jet recording apparatus employing the following configuration. Hereinafter, points different from the above will be described, and description of similar points will be omitted as appropriate.

  (1) In the above, the case where the inkjet recording apparatus 10 is a recording apparatus of a type that records the image by reciprocating the recording unit 30 in the short direction has been described as an example (see FIG. 1). The ink jet recording apparatus 10 may be a line type recording apparatus. In a line-type recording apparatus, nozzles that eject ink of each color are arranged in the short direction. Further, in the line type recording apparatus, the moving unit 40 and the support unit 46 are omitted. The conveyance of the recording medium 14 by the conveyance unit 20 is continuously performed.

  (2) In the above description, the inkjet recording apparatus 10 that records the image by transporting the recording medium 14 in the transport direction by the transport unit 20 and passing the recording unit 30 in the middle of transport has been described as an example (see FIG. 1). The movement of the recording medium and the recording unit in the longitudinal direction may be performed relatively. For example, it is assumed that the recording medium is a strip having a predetermined length. The ink jet recording apparatus includes a table-like placement unit, and the recording medium is placed on the upper surface (placement surface) of the table-like placement unit. The ink jet recording apparatus includes a moving unit corresponding to the moving unit 40 described above and another moving unit that moves the recording unit in the longitudinal direction. The other moving unit moves the recording unit intermittently in the longitudinal direction in accordance with the reciprocating movement of the recording unit. Another moving unit may move the recording unit in the longitudinal direction by moving the moving unit corresponding to the moving unit 40 to which the recording unit is attached in the longitudinal direction.

DESCRIPTION OF SYMBOLS 10 Inkjet recording device 14 Recording medium 15 Recording surface 20 Conveyance part 21 Conveyance surface 30 Recording part 31K, 31M, 31Y, 31C Inkjet head 32 Nozzle 33 Discharge surface 34 Carriage 40 Moving part 41, 42 Pulley 43 Timing belt 46 Support part 50K, 50M, 50Y, 50C Main tank 51K, 51M, 51Y, 51C Supply tube 321 First nozzle 322 Second nozzle G3 Third interval LA First nozzle row LB Second nozzle row W1 First interval W2 Second interval W4 Width

Claims (3)

The first nozzle row aligned in the first direction at a first interval where the nozzle density of the plurality of first nozzles that eject ink is 100 npi or more, and the plurality of second nozzles that eject ink at the first interval A second nozzle array aligned in a first direction, wherein the first nozzle array and the second nozzle array are in a second direction perpendicular to the first direction at a second interval greater than or equal to the first interval. An ink jet recording method for recording an image on a recording medium by ejecting ink droplets using an ink jet head provided adjacent to each other,
An ink jet recording method comprising: controlling ejection of ink from the first nozzle row based on a third interval between a discharge surface of the ink jet head and a recording surface of the recording medium.   The inkjet recording method according to claim 1, wherein the third interval is 3 mm or more.   The ink jet recording method according to claim 1 or 2, wherein the volume of the ejected ink droplet is 45 picoliters or more.