JP6569418B2 - Inkjet recording apparatus and inkjet recording method - Google Patents

Description

  The present invention relates to an ink jet recording apparatus and an ink jet recording method.

  2. Description of the Related Art Conventionally, there is an ink jet recording apparatus that records an image by ejecting ink from a recording element of a recording head to a recording medium while relatively moving a recording head provided with a plurality of recording elements for ejecting ink and the recording medium. Various types of ejected ink have been developed. Among them, there is a property of phase change between solid and liquid, and it solidifies quickly after landing on the recording medium and is fixed on the recording medium. There are phase change inks to make.

  In recent years, in an inkjet recording apparatus, a plurality of recording heads are arranged in different positions in the width direction orthogonal to the direction of relative movement in order to meet the demands for improving the recording speed and increasing the definition of recorded images. A technique is used in which an image is recorded by forming a head unit (recording means) and ejecting ink from recording elements provided in a plurality of recording heads of the long head unit. As this long head unit, one in which a plurality of recording heads are arranged in a staggered pattern so as to overlap the other recording heads in the width direction at the end portions thereof is known.

  In an ink jet recording apparatus including such a long head unit, an operation related to ejection or non-ejection of ink by a recording element of each recording head within the overlapping range in which two recording heads are overlapped in the width direction, That is, a technique is known in which the output operation is performed in a complementary manner to suppress the occurrence of density discontinuity at the joints of a plurality of recording heads. For example, Patent Document 1 defines an operation rate that is a rate at which an output operation is performed by a recording element of one recording head for each position in the width direction in the overlapping range of two recording heads, and the frequency according to the operation rate. Techniques for performing complementary output operations are disclosed. Here, in Patent Document 1, at the position in the width direction where the operation rate is set to ½, the output operation is alternately performed once by the recording elements of each of the pair of recording heads.

JP2012-131110A

  However, the gloss state of the phase change ink changes according to the surface shape of the ink solidified on the recording medium. Normally, when liquid ink lands on an adjacent position on a recording medium, different liquid droplets are connected to form an integral liquid, but when a plurality of recording heads are arranged in a staggered pattern, the recording head In the overlapping portion, ink is ejected from different recording heads to adjacent positions on the recording medium at different timings according to the relative moving speed, so that the ink is first solidified and is less likely to cause liquid drift. Accordingly, there is a problem that even if the image is similar, the surface shape is different from that in the case where ink droplets are ejected from the same recording head, and the difference in gloss tends to occur.

  An object of the present invention is to provide an ink jet recording apparatus and an ink jet recording method capable of suppressing uneven glossiness in an image recorded by a long recording means having a plurality of recording heads.

In order to achieve the above object, the invention of the ink jet recording apparatus according to claim 1 comprises:
Recording means for ejecting ink that changes in phase from a liquid to a solid by being cooled on the recording medium from a plurality of recording elements each provided in a plurality of recording heads in a liquid state ;
Moving means for relatively moving a recording medium and the plurality of recording heads;
Each of the plurality of recording elements provided in the plurality of recording heads of the recording unit causes ink to be ejected to the recording medium that relatively moves in a predetermined movement direction according to the pixel value of image data. Or recording control means for performing recording control for performing an output operation without causing ink to be ejected corresponding to one line of the image data ;
With
The plurality of recording elements are provided at predetermined intervals in the width direction orthogonal to the one moving direction in each of the plurality of recording heads,
Each of the plurality of recording heads overlaps with the other recording head in the width direction in a range near a predetermined end, and is disposed at a different position with respect to the one recording head and the one movement direction,
In the recording control, the recording control unit is configured to perform upstream recording in the one movement direction of the pair of overlapping recording heads with respect to the same position in the one movement direction of the recording medium. After performing the output operation by the recording element of the head, a time difference corresponding to the distance in the one moving direction between the downstream recording head and the upstream recording head of the pair of recording heads is provided. Causing the recording element of the downstream recording head to perform the output operation;
The ink ejected from the recording element of the upstream recording head and landed at one position in the one moving direction on the recording medium is transferred from the recording element of the downstream recording head to the recording medium. Phase change to solid before ink is ejected and landed at the one position,
The recording control means includes
In each position in the width direction in the end portion vicinity range, it performs the recording control to either of the respective belonging recording elements in the recording head prior Symbol a pair perform the output operation,
Prior Kitan portion near range, at each position in the width direction, more complementarily the output operation to the recording element of the pair of recording heads for different positions on the one movement direction of the recording medium Determine the setting range in the width direction to be performed,
In the above setting range, the continuous in a plurality of the recording control performed continuously in response to a plurality of lines of the image data, by a predetermined number of operations of two or more of the same of the recording elements, respectively at each position in the width direction Thus, the output operation is performed.

According to a second aspect of the present invention, in the ink jet recording apparatus according to the first aspect,
The recording control means has an operation rate, which is a ratio at which the output operation is performed by a recording element of one recording head of the pair of recording heads, from an end portion in the vicinity of the end portion of the one recording head. The recording element that performs the output operation is selected so as to monotonously increase in the vicinity of the end as the distance increases.

The invention according to claim 3 is the ink jet recording apparatus according to claim 2,
The recording control means determines the operating rate for each position in the width direction within the range near the end, and selects whether to cause each of the recording elements to perform the output operation according to the operating rate. It is a feature.

According to a fourth aspect of the present invention, in the ink jet recording apparatus according to the second aspect,
The recording control means determines the operation rate for each of a plurality of ranges obtained by dividing the set range in the width direction, and performs the output operation according to the operation rate for each of the plurality of ranges. The selection is made every predetermined number of times of the recording control.

The invention according to claim 5 is the ink jet recording apparatus according to claim 2,
The recording control means is arranged in the width direction at a position where the output operation is performed by the recording element of one of the pair of recording heads within the vicinity of the end portion for each predetermined number of recording controls. The recording element for performing the output operation is selected so that the interval becomes closer to the end of the one recording head.

The invention according to claim 6 is the ink jet recording apparatus according to any one of claims 1 to 3,
The predetermined number of operations is determined to be different from each other at positions adjacent in the width direction within the set range.

The invention according to claim 7 is the ink jet recording apparatus according to any one of claims 1 to 3,
The recording control means is characterized in that the timing for switching the recording element for performing the output operation at each position adjacent in the width direction within the set range is different from each other.

The invention according to claim 8 is the ink jet recording apparatus according to any one of claims 1 to 7, wherein
The predetermined number of operations is determined according to the number of the recording elements provided in the setting range in each of the pair of recording heads.

In order to achieve the above object, an ink jet recording method according to claim 9
Recording means for ejecting ink that changes in phase from a liquid to a solid by being cooled on the recording medium from a plurality of recording elements respectively provided on a plurality of recording heads, and the recording medium And a moving means for relatively moving the plurality of recording heads, and an ink jet recording method using an ink jet recording apparatus,
Each of the plurality of recording elements provided in the plurality of recording heads of the recording unit causes ink to be ejected to the recording medium that relatively moves in a predetermined movement direction according to the pixel value of image data. Or a recording step of performing recording control for performing an output operation without ejecting ink corresponding to one line of the image data ,
The plurality of recording elements of the inkjet recording apparatus are provided at predetermined intervals in the width direction orthogonal to the one movement direction in the plurality of recording heads, respectively.
Each of the plurality of recording heads of the ink jet recording apparatus overlaps with the other recording head in the width direction in a range near a predetermined end, and is different from the one recording head with respect to the one moving direction. Placed in
In the recording step, in the recording control, the upstream recording head in the one moving direction of the pair of overlapping recording heads with respect to the same position in the one moving direction of the recording medium. After performing the output operation by the recording element, the time difference corresponding to the distance in the one moving direction between the downstream recording head and the upstream recording head of the pair of recording heads is provided. Causing the recording element of the downstream recording head to perform the output operation;
The ink ejected from the recording element of the upstream recording head and landed at one position in the one moving direction on the recording medium is transferred from the recording element of the downstream recording head to the recording medium. Phase change to solid before ink is ejected and landed at the one position,
In the recording step,
In each position in the width direction in the end portion vicinity range, it performs the recording control to either of the respective belonging recording elements in the recording head prior Symbol a pair perform the output operation,
Prior Kitan portion near range, at each position in the width direction, more complementarily the output operation to the recording element of the pair of recording heads for different positions on the one movement direction of the recording medium Determine the setting range in the width direction to be performed,
In the above setting range, the continuous in a plurality of the recording control performed continuously in response to a plurality of lines of the image data, by a predetermined number of operations of two or more of the same of the recording elements, respectively at each position in the width direction Thus, the output operation is performed.

  According to the present invention, there is an effect that uneven gloss in an image recorded by a long recording unit having a plurality of recording heads can be suppressed.

1 is a diagram illustrating a schematic configuration of an ink jet recording apparatus according to an embodiment of the present invention. It is a schematic diagram which shows the structure of a head unit. It is a block diagram which shows the main function structures of an inkjet recording device. It is a figure which shows the example of the complementary output operation | movement and operation rate in an overlapping range. It is a figure explaining the difference in the coagulation | solidification aspect of the ink according to the discharge position of an ink. It is a flowchart which shows the control procedure of an image recording process. It is a figure which shows the example of complementary output operation | movement in the overlapping range in a modification 1, and an operation rate. 10 is a diagram illustrating an example of complementary output operation in an overlapping range in Modification 2. FIG.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments according to an ink jet recording apparatus and an ink jet recording method of the present invention will be described below with reference to the drawings.

FIG. 1 is a diagram showing a schematic configuration of an ink jet recording apparatus 1 according to an embodiment of the present invention.
The ink jet recording apparatus 1 includes a paper feeding unit 10, an image recording unit 20, a paper discharge unit 30, and a control unit 40 (FIG. 3). Under the control of the control unit 40, the inkjet recording apparatus 1 conveys the recording medium P stored in the paper feeding unit 10 to the image recording unit 20, and the image recording unit 20 records an image on the recording medium P. The recorded recording medium P is conveyed to the paper discharge unit 30.
As the recording medium P, in addition to paper such as plain paper or coated paper, various media capable of solidifying the ink ejected on the surface, such as a cloth or a sheet-like resin, can be used.

  The paper supply unit 10 includes a paper supply tray 11 that stores the recording medium P, and a medium supply unit 12 that conveys and supplies the recording medium P from the paper supply tray 11 to the image recording unit 20. The medium supply unit 12 includes a ring-shaped belt whose inner side is supported by two rollers, and conveys the recording medium P by rotating the roller while the recording medium P is placed on the belt.

  The image recording unit 20 includes a transport drum 21 (moving unit), a delivery unit 22, a heating unit 23, a head unit 24 (recording unit), a fixing unit 25, a delivery unit 26, and the like.

The conveyance drum 21 is recorded by rotating around a rotation axis extending in a direction (X direction) perpendicular to the drawing of FIG. 1 while holding the recording medium P on a conveyance surface which is a cylindrical outer peripheral surface. The medium P is transported in the transport direction (Y direction) along the transport surface. The transport drum 21 includes a claw portion and a suction portion (not shown) for holding the recording medium P on the transport surface. The end of the recording medium P is pressed by the claw portion, and the recording medium P is held on the transport surface by being sucked to the transport surface by the intake portion.
The transport drum 21 is connected to a transport drum motor (not shown) for rotating the transport drum 21 and rotates by an angle proportional to the rotation amount of the transport drum motor.

  The delivery unit 22 delivers the recording medium P conveyed by the medium supply unit 12 of the paper supply unit 10 to the conveyance drum 21. The delivery unit 22 is provided at a position between the medium supply unit 12 and the conveyance drum 21 of the paper supply unit 10, and holds one end of the recording medium P conveyed from the medium supply unit 12 by the swing arm unit 221. Then, it is delivered to the transport drum 21 through the delivery drum 222.

  The heating unit 23 is provided between the arrangement position of the transfer drum 222 and the arrangement position of the head unit 24, and the recording medium P conveyed by the conveyance drum 21 has a temperature within a predetermined temperature range. Heat P. The heating unit 23 includes, for example, an infrared heater, and energizes the infrared heater based on a control signal supplied from the CPU 41 (FIG. 3) to cause the heater to generate heat.

  The head unit 24 records an image by ejecting ink onto the recording medium P at an appropriate timing according to the rotation of the transport drum 21 on which the recording medium P is held based on the image data. The head unit 24 is disposed with a predetermined distance between the ink discharge surface and the transport drum 21. In the ink jet recording apparatus 1 of the present embodiment, four head units 24 respectively corresponding to four color inks of yellow (Y), magenta (M), cyan (C), and black (K) are transported in the recording medium P. They are arranged so as to be arranged at predetermined intervals in the order of Y, M, C, and K colors from the upstream side.

FIG. 2 is a schematic diagram showing the configuration of the head unit 24. In this figure, the position of the nozzles of the recording element 243 provided in the recording head 242 is schematically shown in a plan view of the head unit 24 as viewed from the side facing the conveyance surface of the conveyance drum 21.
Each head unit 24 includes four recording heads 242 in which a plurality of recording elements 243 are arranged in a direction intersecting the transport direction of the recording medium P (in this embodiment, a direction orthogonal to the transport direction, that is, the X direction).
The four recording heads 242 included in the head unit 24 overlap with the other recording head 242 in the X direction within a predetermined vicinity range (end vicinity range) from the end of the recording head 242, and the other The recording elements 243 of the first and third recording heads 242 are arranged on the same line along the X direction. In the range in the vicinity of the ends of the pair of recording heads 242 arranged overlapping in the X direction, the arrangement range in the X direction of the recording elements 243 belonging to the pair of recording heads 242 overlaps in the overlapping range R. The pair of recording heads 242 are arranged in a positional relationship in which the positions of the recording elements 243 of the recording heads 242 in the overlapping range R coincide with each other in the X direction. In the overlapping range R, ink is complementarily discharged by the recording elements 243 of the pair of recording heads 242. The ink ejection in the overlapping range R will be described in detail later. Hereinafter, the range excluding the overlapping range R in the arrangement range of the recording elements 243 in the recording head 242 is also referred to as a non-overlapping range.

The arrangement range in the X direction of the recording element 243 included in the head unit 24 covers the width in the X direction of an area in which an image can be recorded in the recording medium P conveyed by the conveyance drum 21. Is used with its position fixed relative to the rotation axis of the transport drum 21 during image recording. That is, the inkjet recording apparatus 1 is a single-pass inkjet recording apparatus. The recording elements 243 in the head unit 24 are arranged at 1200 dpi (dot per inch) in the X direction, for example.
Note that the recording head 242 may include two or more rows (nozzle rows) of recording elements 243. For example, a configuration in which two rows of recording elements 243 arranged in the X direction are provided, and these two rows of recording elements 243 are arranged so as to be shifted from each other by a half of the arrangement interval of the recording elements 243 in the X direction. It may be. Further, the number of recording heads 242 included in the head unit 24 may be three or less, or five or more.

The head unit 24 also includes a recording head drive unit 241 (FIG. 3) that drives the recording head 242. The recording head drive unit 241 includes a drive circuit that supplies a voltage signal having a drive waveform corresponding to image data to each print head 242 and a drive control circuit that supplies image data to the drive circuit at an appropriate timing. .
Each of the recording elements 243 included in the recording head 242 includes a pressure chamber for storing ink, a piezoelectric element provided on a wall surface of the pressure chamber, and a nozzle. A drive waveform voltage signal for deforming the piezoelectric element is output from the drive circuit of the recording head drive unit 241, and the recording element 243 is configured to apply the voltage signal to the piezoelectric element. When a voltage signal having a drive waveform is applied to the piezoelectric element, the pressure chamber is deformed in accordance with the voltage signal and the pressure in the pressure chamber is changed. In response to the change in pressure, ink is ejected from the nozzle communicating with the pressure chamber. Discharged. When the pixel value of the image data is a value corresponding to non-ejection of ink, the recording element 243 is supplied with a voltage signal having a driving waveform such that ink is not ejected from the nozzle. That is, the recording element 243 performs an output operation in which an amount of ink corresponding to the pixel value of the image data is ejected from the nozzle or not according to the voltage signal of the drive waveform.

As ink ejected from the nozzles of the recording element 243, ink that changes in phase between a solid and a liquid is used. In the present embodiment, an ink is used that changes in phase between a gel state and a sol state depending on temperature and is cured by irradiation with energy rays such as ultraviolet rays. Here, the gel is contained in a solid and the sol is contained in a liquid.
In this embodiment, ink that is gel-like at room temperature and becomes sol-like when heated is used. The head unit 24 includes an ink heating unit 244 (FIG. 3) (ink heating unit) that heats ink stored in the head unit 24, and the ink heating unit 244 operates under the control of the CPU 41 (FIG. 3). Then, the ink is heated to a temperature that becomes a sol. The recording head 242 discharges ink that has been heated to form a sol. When this sol-like ink is ejected onto the recording medium P, the ink droplets land on the recording medium P, and then naturally cool, so that the ink quickly becomes a gel and the volume of the recording medium hardly shrinks. It solidifies on P. Here, solidifying on the recording medium P means that at least a part of the ink that has landed on the recording medium P is in a state in which the shape of the ink droplet is maintained to some extent before the ink penetrates the recording medium P, that is, the recording medium P It means solidifying in a state having a surface shape different from the surface shape. The surface of the ink solidified in this state scatters incident light according to the surface shape.

  The fixing unit 25 has a light emitting unit arranged over the width of the transport drum 21 in the X direction, and irradiates the recording medium P placed on the transport drum 21 with energy rays such as ultraviolet rays from the light emitting unit. Then, the ink discharged on the recording medium P is cured and fixed. The light emitting unit of the fixing unit 25 is arranged to face the conveyance drum 21 on the downstream side in the conveyance direction with respect to the arrangement position of the head unit 24 in the conveyance direction.

  The delivery unit 26 includes a belt loop 262 having an annular belt supported on the inside by two rollers, and a cylindrical transfer drum 261 that transfers the recording medium P from the transport drum 21 to the belt loop 262. The recording medium P transferred from the transfer drum 21 onto the belt loop 262 by the transfer drum 261 is transferred by the belt loop 262 and sent to the paper discharge unit 30.

  The paper discharge unit 30 includes a plate-shaped paper discharge tray 31 on which the recording medium P sent out from the image recording unit 20 by the delivery unit 26 is placed.

FIG. 3 is a block diagram showing the main functional configuration of the inkjet recording apparatus 1.
The inkjet recording apparatus 1 includes a control unit 40 having a CPU 41 (Central Processing Unit) (recording control means), a RAM 42 (Random Access Memory), a ROM 43 (Read Only Memory), and a storage unit 44, a heating unit 23, and a head unit 24. A recording head driving unit 241 for driving the recording head 242, an ink heating unit 244, a fixing unit 25, a transport driving unit 51, an input / output interface 52, a bus 53, and the like.

  The CPU 41 reads various control programs and setting data stored in the ROM 43, stores them in the RAM 42, executes the programs, and performs various arithmetic processes. Thus, the CPU 41 controls the overall operation of the inkjet recording apparatus 1. For example, the CPU 41 operates each unit of the image recording unit 20 based on the image data stored in the storage unit 44 to record an image on the recording medium P.

  The RAM 42 provides a working memory space to the CPU 41 and stores temporary data. The RAM 42 may include a nonvolatile memory.

  The ROM 43 stores various control programs executed by the CPU 41, setting data, and the like. This setting data includes mask pattern data described later. The mask pattern data may be stored in the storage unit 44. In place of the ROM 43, a rewritable nonvolatile memory such as an EEPROM (Electrically Erasable Programmable Read Only Memory) or a flash memory may be used.

  The storage unit 44 stores a print job (image recording command) input from the external device 2 via the input / output interface 52 and image data related to the print job. As the storage unit 44, for example, an HDD (Hard Disk Drive) is used, and a DRAM (Dynamic Random Access Memory) or the like may be used in combination.

  The recording head drive unit 241 causes the recording head 242 to eject ink based on the control signal and image data supplied from the CPU 41. Specifically, when a control signal including image data is supplied from the CPU 41, the drive control circuit of the recording head drive unit 241 causes the drive circuit to apply any of the drive waveforms of a plurality of patterns to the piezoelectric element of the recording element 243 of the recording head 242. A voltage signal having a driving waveform is output.

  The ink heating unit 244 has a heating wire, and heats the ink by energizing the heating wire based on a control signal supplied from the CPU 41 to generate heat.

  The transport driving unit 51 supplies a drive signal to the transport drum motor of the transport drum 21 based on a control signal supplied from the CPU 41 to rotate the transport drum 21 at a predetermined speed and timing. Further, the transport driving unit 51 supplies a drive signal to a motor for operating the medium supply unit 12, the delivery unit 22, and the delivery unit 26 based on a control signal supplied from the CPU 41, so that the recording medium P is transported. Supply to the drum 21 and discharge from the transport drum 21 are performed.

  The input / output interface 52 is means for transmitting and receiving data to and from the external device 2 and is configured by, for example, one of various serial interfaces, various parallel interfaces, or a combination thereof.

  The bus 53 is a path for transmitting and receiving signals between the control unit 40 and other components.

  The external device 2 is, for example, a personal computer, and supplies a print job, image data, and the like to the control unit 40 via the input / output interface 52.

Next, the output operation by the recording element 243 in the overlapping range R in the inkjet recording apparatus 1 of the present embodiment will be described.
In the inkjet recording apparatus 1 of the present embodiment, in the overlapping range R, the above-described output operation is performed complementarily by the recording elements 243 belonging to each of the pair of recording heads 242 having the recording elements 243 in the overlapping range R.
Hereinafter, the recording head 242 on the downstream side in the transport direction with a slow timing of performing the output operation on the same position in the transport direction on the recording medium P out of the pair of recording heads 242 is also referred to as a downstream recording head. The upstream recording head 242 is also referred to as an upstream recording head.

FIG. 4 is a diagram illustrating an example of complementary output operation and operation rate in the overlapping range R.
In the upper part of FIG. 4, one downstream recording head 242D and two upstream recording heads 242Ua and 242Ub (hereinafter collectively upstream) in which the downstream recording head 242D and the recording element 243 partially overlap with each other in the X direction are arranged. And a plan view of the recording medium P from which ink is ejected by these recording heads 242 as viewed from the side facing the conveying surface of the conveying drum 21 is shown. In this plan view, the position of the nozzle of the recording element 243 of the upstream recording head 242U is schematically shown by a circle with dots, and the position of the nozzle of the recording element 243 of the downstream recording head 242D is a white circle. Is shown schematically. Further, in this plan view, in the recording medium P, the upstream recording head among the positions where the output operation can be performed by the recording elements 243 of the upstream recording head 242U and the downstream recording head 242D (ink dischargeable position). A position where an output operation is performed by the recording element 243 of 242U is indicated by a circle with dots, and a position where an output operation is performed by the recording element 243 of the downstream recording head 242D is indicated by a white circle.

  As shown in the upper part of FIG. 4, in the present embodiment, in the overlapping range R (setting range), among the recording elements 243 of the upstream recording head 242U and the downstream recording head 242D, the recording element pairs whose positions in the X direction match. Each of the recording elements 243p of 243p continuously performs an output operation at a predetermined number of times of two or more at a plurality of ink dischargeable positions adjacent in the Y direction, and the continuous output operation is performed by the recording elements of the recording element pair 243p. 243 are determined alternately.

The graph at the bottom of FIG. 4 shows the operation rate, which is the rate at which the output operation is performed by the recording elements 243 of the upstream recording head 242U and the downstream recording head 242D at each position in the X direction. In this graph, the operating rate (upstream operating rate) related to the upstream recording head 242U is indicated by a broken line, and the operating rate (downstream operating rate) related to the downstream recording head 242D is indicated by a solid line.
In the present embodiment, the downstream operation rate in the overlapping range R is determined so as to increase monotonously with an increase in the distance from the end of the downstream recording head 242D that is close to the overlapping range R. Further, the upstream operation rate is determined so that the sum with the downstream operation rate is 1 at each position in the X direction. Accordingly, the upstream operation rate is determined so as to monotonously decrease in accordance with the increase in the distance from the end portion side of the downstream recording head 242D in the overlapping range R.

Each recording element 243 of each recording element pair 243p performs an output operation at a frequency according to the operation rate at the position in the X direction of the recording element pair 243p.
That is, as shown in the upper part of FIG. 4, in the overlapping range R, in the recording element pair 243p provided at the end position of the downstream recording head 242D, the upstream operation rate is 0.8 (downstream side). The output operation is performed at eight continuous ink dischargeable positions in the Y direction by the recording elements 243 of the upstream recording head 242U so that the operation rate becomes 0.2), and by the recording elements 243 of the downstream recording head 242D. An output operation is performed at two consecutive ink dischargeable positions in the Y direction. Further, as the distance from the end of the downstream recording head 242D increases, the number of continuous output operations by the recording element 243 of the upstream recording head 242U decreases, and the output operation by the recording element 243 of the downstream recording head 242D continues. The number increases. In the overlapping range R, in the recording element pair 243p provided at the end portion opposite to the end portion side of the downstream recording head 242D, the upstream operation rate is 0.2 (the downstream operation rate is 0. 0). 8), the recording element 243 of the upstream recording head 242U performs an output operation at two continuous ink dischargeable positions in the Y direction, and eight recording elements in the Y direction are performed by the recording element 243 of the downstream recording head 242D. An output operation is performed at successive ink dischargeable positions.

Here, the position in the Y direction at which the recording element 243 that performs the output operation switches, that is, the timing at which the recording element 243 that performs the output operation switches, differs between the recording element pairs 243p adjacent in the X direction.
Further, the continuous number of output operations by the recording elements 243 can be determined according to the number of recording elements 243 provided in the overlapping range R in one recording head 242. For example, as the number of recording elements 243 provided in the overlapping range R increases, the lower limit value of the continuous number of output operations by each recording element 243 may be increased.
In FIG. 4, the continuous number of output operations of the recording element 243 is equal between the two recording element pairs 243p adjacent in the X direction, but the continuous number is different between the two adjacent recording element pairs 243p. More preferably. Further, the continuous number of output operations of the recording elements 243 provided in the overlapping range R may be all different values.

In order to perform such complementary ink ejection, in the inkjet recording apparatus 1, the upstream recording head 242U and the downstream recording head are applied to the portion corresponding to the overlapping range R in the image data related to the image to be recorded. By applying predetermined mask pattern data having a mask pattern corresponding to the operation rate of the 242D printing element 243, mask image data in which part of the pixel data is changed to pixel data corresponding to non-ejection of ink is obtained. Generated. Then, by supplying mask image data to the upstream recording head 242U and the downstream recording head 242D, a complementary output operation as shown in FIG.
Here, generation of mask image data and supply to the recording head 242 are performed for each line (pixel row) of image data. Further, the control for performing the output operation by the recording element 243 for each line constitutes the recording control, and the inkjet recording apparatus 1 performs the recording control for the number of times corresponding to the number of lines of the pixel data.

  Next, a solidification mode of the ink ejected on the recording medium P by the inkjet recording apparatus 1 and a gloss of the recorded image according to the solidification mode of the ink will be described.

  In the ink jet recording apparatus 1 of the present embodiment, upstream recording is performed after ink is ejected from the upstream recording head 242U to the same position in the Y direction of the recording medium P that is transported in the Y direction by the transport drum 21. Ink is ejected from the downstream recording head 242D with a time difference corresponding to the distance in the Y direction between the head 242U and the downstream recording head 242D. Further, since the ink that has landed on the recording medium P solidifies quickly, in the area corresponding to the overlapping range R in the recording medium P, the ink discharged from the upstream recording head 242U solidifies and then the downstream recording head 242D. The ink discharged from the ink is discharged and solidified. For this reason, the ink ejected from the upstream recording head 242U and the downstream recording head 242D is not connected and mixed before solidifying.

  Also, the ink droplets that have landed at the ink dischargeable position on the recording medium P shown in the upper part of FIG. 4 spread over a wider range than the circle indicating the ink dischargeable position. In the following, the diameter of a circle indicating the range in which the landed ink droplet spreads is also referred to as the dot diameter. In the present embodiment, the dot diameter of one ink droplet is about twice the arrangement interval of the circles indicating the ink dischargeable positions in FIG. Therefore, after the ink ejected by the upstream recording head 242U has solidified, the ink ejected by the downstream recording head 242D becomes the adjacent ink ejectable position in the ink ejectable positions in FIG. When landed on the ink dischargeable position, these ink droplets coagulate in a state where they are connected to each other.

FIG. 5 is a diagram for explaining the difference in the coagulation mode of the ink according to the ink ejection position.
FIG. 5A is a diagram for explaining a coagulation mode of ink landed on every other ink dischargeable position p1, p3 in the Y direction.
As shown in the upper part of FIG. 5A, the two ink droplets ejected to the ink ejectable positions p1 and p3 spread over a range indicated by a broken-line circle. As a result, the two ink droplets are connected to form ink Ia, which solidifies in a state where the ink spreads in a range indicated by dots in the middle part of FIG. The ink Ia thus solidified is solidified in a state of spreading in the Y direction, as shown in the lower cross-sectional view of FIG. 5A (cross-sectional view taken along line AA in the middle of FIG. 5A). As a result, the thickness at each position of the ink Ia becomes a substantially uniform and small value, and the surface becomes relatively flat, and the scattering range of the reflected light of the light incident on the surface of the ink Ia becomes narrow. As a result, the gloss in the recorded image is increased in the area where the ink Ia is solidified.

FIG. 5B is a diagram for explaining a solidification mode of ink landed on the ink dischargeable positions p1 and p2 adjacent in the Y direction.
As shown in the upper part of FIG. 5B, the two ink droplets ejected to the ink ejectable positions p1 and p2, respectively, spread in the range indicated by the dashed circle. As a result, the two ink droplets are connected to form ink Ib, which solidifies in a state of being distributed in the range indicated by dots in the middle part of FIG. This range is narrower than the range in which the ink Ia shown in the middle part of FIG. Therefore, the ink Ib solidified in such a narrow range is separated from the ink Ia as shown in the lower cross-sectional view of FIG. 5B (the cross-sectional view taken along line BB in the middle of FIG. 5B). Compared to the surface of the recording medium P, the surface of the recording medium P is raised higher, and thus the diffusion range of the reflected light of the light incident on the surface of the ink Ib is increased. As a result, in the region where the ink Ib is solidified, the gloss in the recorded image is smaller than in the region where the ink Ia is solidified.

  In the present embodiment, as shown in FIG. 4, since the ink ejected by the recording element 243 of the downstream recording head 242D in the overlapping range R is ejected to the ink ejectable position continuous in the Y direction, FIG. It solidifies in the state shown in (b). In the non-overlapping range other than the overlapping range R, ink is ejected by the recording elements of one recording head 242 at all ink ejectable positions in the Y direction, so that the ink ejected on the recording medium P is the same. Then, it solidifies in the state as shown in FIG. As a result, since the output operation is continuously performed by the recording elements 243 in the overlapping range, gloss between the overlapping range R and the non-overlapping range is less likely to occur, and thus uneven gloss in the recorded image is suppressed.

  Next, a control procedure by the CPU 41 for image recording processing executed by the inkjet recording apparatus 1 will be described.

FIG. 6 is a flowchart showing the control procedure of the image recording process.
This image recording process is executed when, for example, a print job and image data are input from the external device 2 to the control unit 40 via the input / output interface 52.

  When the image recording process is started, the CPU 41 applies each recording head 242 to one line of pixel data composed of pixels corresponding to the recording elements 243 of the four recording heads 242 of the head unit 24 in the image data. By applying mask pattern data reflecting the operation rate determined in the overlapping range R, line pixel data (mask image data) composed of pixel data supplied to each recording head 242 of the head unit 24 is generated (step). S1).

  The CPU 41 causes the head unit 24 to eject ink based on the line pixel data generated in step S1, and records a portion corresponding to one line in the image (step S2: recording step). That is, the CPU 41 outputs a control signal to the transport driving unit 51 and rotates the transport drum 21 by the transport driving unit 51 to transport the recording medium P. Then, the CPU 41 supplies a control signal including line image data to the recording head driving unit 241, and outputs a voltage signal having a driving waveform by the recording head driving unit 241 at an appropriate timing according to the rotation of the transport drum 21. As a result, the ink is ejected from the recording element 243 of the head unit 24 onto the recording medium P conveyed by the conveying drum 21 so that a part of the image is recorded on the recording medium P.

  The CPU 41 determines whether or not recording has been completed for all portions of the image to be recorded (step S3). When it is determined that there is an unrecorded part (“No” in step S3), the CPU 41 shifts the process to step S1, and the line processed in step S1 performed last in the image data. The process is executed for the next line.

When it is determined that the recording has been completed for all the parts of the image to be recorded (“Yes” in step S3), the CPU 41 conveys the recording medium P to the paper discharge unit 30 (step S4).
When the process of step S4 ends, the CPU 41 ends the image recording process.
The image recording process is a process related to one head unit 24, and the CPU 41 performs the image recording process in parallel with respect to each of the four head units 24 corresponding to Y, M, C, and K. And run.

  As described above, the ink jet recording apparatus 1 according to the present embodiment ejects ink that changes in phase between solid and liquid to the recording medium P from the recording elements 243 provided in each of the plurality of recording heads 242. The CPU 41 is provided with a plurality of recording elements provided in the plurality of recording heads 242 of the head unit 24. The CPU 41 includes a head unit 24 that performs the relative movement of the recording medium P and the plurality of recording heads 242, and a CPU 41. Each of 243 performs recording control for causing the recording medium P to move relatively in the Y direction to perform an output operation in which ink is ejected or ink is not ejected according to the pixel value of the image data (recording control means). The recording elements 243 are provided at predetermined intervals in the X direction orthogonal to the Y direction in the plurality of recording heads 242, respectively. Each of the heads 242 overlaps with the other recording head 242 in the X direction in a predetermined end vicinity range, and is disposed at a different position in the Y direction with respect to the one recording head 242. At each position in the X direction within the vicinity range, recording control is performed to cause any one of the recording elements 243 belonging to the pair of overlapping recording heads 242 to perform an output operation (recording control unit), and the recording control is performed. Then, an overlapping range R (setting range) in which an output operation is performed by both of the recording elements 243 of the pair of recording heads 242 at each position in the X direction in the vicinity of the end portion is determined. At each position in the direction, the same recording element 243 causes the output operation to be performed continuously two or more times. As a result, an output operation is performed at a position adjacent to the Y direction by each recording element 243 in an area corresponding to the overlapping range R on the recording medium P, and the discharged ink is connected to each other before spreading over a wide range. It becomes easy to solidify in a raised state. Since the positional relationship and coagulation mode of the ejected ink are the same as those in the non-overlapping range, it is difficult to vary the degree of scattering of incident light between the regions corresponding to the overlapping range R and the non-overlapping range. And the occurrence of uneven gloss in the recorded image can be suppressed. Further, when each recording element 243 arranged in the overlapping range R performs an output operation at a position adjacent to the Y direction, when the recording head 242 is displaced in the Y direction, the upstream recording head 242U and Due to the fact that the recording elements 243 of the downstream recording head 242D are less likely to overlap or separate the ink ejected to adjacent ink ejection positions in the Y direction. The occurrence of uneven density and periodic gloss fluctuations can be suppressed.

  Further, the CPU 41 has an operation rate, which is a ratio at which an output operation is performed by the recording element 243 of one recording head 242 of the pair of recording heads 242, from the end portion in the vicinity of the end portion of the one recording head 242. The recording element 243 that performs the output operation is selected so as to monotonously increase in the vicinity of the end as the distance increases. Thereby, since the amount of change in the operation rate by the recording element 243 of each recording head 242 can be reduced between portions corresponding to the overlapping range R and the non-overlapping range in the recorded image, the overlapping range R and the non-overlapping It is possible to suppress uneven density between portions corresponding to the ranges.

  Further, the CPU 41 determines the frequency with which each recording element performs an output operation according to the operation rate for each position in the X direction within the edge vicinity range, and determines whether or not to cause each recording element 243 to perform an output operation according to the frequency. Is selected (recording control means). Accordingly, complementary output operations can be performed at each position in the X direction where the recording element 243 is disposed.

  In addition, the predetermined number of operations is determined to be different from each other at positions adjacent to each other in the X direction within the overlapping range R. As a result, the boundary positions of the ink ejected by the upstream recording head 242U and the downstream recording head 242D are dispersed in the Y direction, so that the upstream recording head 242U and the downstream recording head 242D are displaced in the Y direction. Gloss unevenness and density unevenness due to variations in ink discharge amount and discharge direction can be made inconspicuous.

  In addition, the CPU 41 changes the timing for switching the recording element 243 that performs the output operation at each of the positions adjacent to each other in the X direction within the overlapping range R (recording control unit). As a result, the boundary positions of the ink ejected by the upstream recording head 242U and the downstream recording head 242D are dispersed in the Y direction, so that the upstream recording head 242U and the downstream recording head 242D are displaced in the Y direction. Gloss unevenness and density unevenness due to variations in ink discharge amount and discharge direction can be made inconspicuous.

  The predetermined number of operations is determined according to the number of recording elements 243 provided in the overlapping range R in each of the pair of recording heads 242 in the overlapping range R. Thereby, according to the number of recording elements 243 in the overlapping range R, it is possible to record an image by setting an appropriate predetermined number that suppresses the occurrence of uneven gloss in the recorded image.

  In addition, in the ink jet recording method by the ink jet recording apparatus 1 according to the present embodiment, ink that changes in phase between a solid and a liquid is applied to the recording medium P from a plurality of recording elements 243 provided in each of a plurality of recording heads 242. An ink jet recording method using an ink jet recording apparatus 1 that includes an ejecting head unit 24 and a transport drum 21 that relatively moves a recording medium P and a plurality of recording heads 242, and includes a plurality of recording heads 242 of the head unit 24. Each of the plurality of recording elements 243 provided performs recording control for causing the recording medium P relatively moving in the Y direction to perform an output operation in which ink is ejected or ink is not ejected according to the pixel value of the image data. A plurality of recording elements 243 of the inkjet recording apparatus 1 including a recording step, Each of the plurality of recording heads 242 overlaps with the other recording head 242 in the X direction in the vicinity of a predetermined end portion, and is provided at a predetermined interval in the X direction orthogonal to the Y direction. Further, the recording elements are arranged at different positions in the Y direction with respect to the one recording head 242, and in the recording step, the recording elements respectively belonging to the pair of recording heads 242 arranged in duplicate in each position in the X direction within the range near the end. In this recording control, both the recording elements 243 of the pair of recording heads 242 perform the output operation at each position in the X direction within the vicinity of the end portion. An overlapping range R (set range) is defined, and within the overlapping range R, two or more predetermined operations are continuously output by the same recording element 243 at each position in the X direction. To perform the operation. As a result, the degree of scattering of incident light is less likely to vary between regions corresponding to the overlapping range R and the non-overlapping range on the recording medium P, so that the occurrence of uneven gloss in the recorded image can be suppressed. . In addition, it is possible to suppress the occurrence of density unevenness and periodic gloss fluctuation caused by the positional deviation of the recording head 242 in the Y direction.

(Modification 1)
Subsequently, Modification 1 of the above embodiment will be described. The first modification is different from the above-described embodiment in that a recording element 243 that complementarily performs an output operation within the overlapping range R is determined for each predetermined number of output operations according to the operation rate. Hereinafter, differences from the above embodiment will be described.

FIG. 7 is a diagram illustrating an example of complementary output operation and operation rate in the overlapping range R in the first modification.
As shown in FIG. 7, in the first modification, each position in the X direction in the ink discharge area DA1 including five ink dischargeable positions in the Y direction among the areas corresponding to the overlapping range R on the recording medium P. The recording element 243 that performs the output operation is fixed. Further, the operation rate is determined for each of the ranges r1 to r3 obtained by dividing the overlapping range R in the X direction. In the ink ejection area DA1, recording elements 243 that perform an output operation in each of the ranges r1 to r3 are determined according to the operation rates set in the respective ranges r1 to r3. For example, in the range r1, the downstream printing rate is set to 1/4 and the upstream printing rate is set to 3/4. Therefore, one of the four printing element pairs 243p provided in the range r1 is one printing element pair 243p. In FIG. 3, an output operation is performed by the recording element 243 of the downstream recording head 242D, and an output operation is performed by the recording element 243 of the downstream recording head 242D in the three recording element pairs 243p.
The recording element 243 that performs the output operation is selected every five output operations (that is, every time the target ink discharge area DA1 for performing the output operation is switched).
Here, the continuous number of output operations by the recording elements 243 (that is, the size of the ink ejection area DA1 in the Y direction) is determined according to the number of recording elements 243 provided in the overlapping range R in one recording head 242. Can do. For example, as the number of recording elements 243 provided in the overlapping range R increases, the number of continuous output operations by each recording element 243 may be increased.

  As described above, in the inkjet recording apparatus 1 according to the first modification, the recording element 243 that causes the output operation to be performed in each of the plurality of ranges obtained by dividing the overlapping range R in the X direction according to the operation rate according to each of the plurality of ranges. Is determined for each predetermined number of times of recording control (recording control means). Accordingly, complementary ejection can be performed while suppressing uneven gloss by a simple method of selecting the recording element 243 that performs the output operation at each position in the X direction.

(Modification 2)
Then, the modification 2 of the said embodiment is demonstrated. The second modification is different from the first modification in the selection rule of the recording element 243 that performs the output operation. Hereinafter, differences from the first modification will be described.

FIG. 8 is a diagram illustrating an example of a complementary output operation in the overlapping range R in the second modification.
As shown in FIG. 8, in Modification 2, each position in the X direction in the ink discharge area DA2 including five ink dischargeable positions in the Y direction among the areas corresponding to the overlapping range R on the recording medium P. The recording element 243 that performs the output operation is fixed. Here, in the recording element 243 that performs the output operation, the interval in the X direction of the position where the output operation is performed by the recording element 243 of the downstream recording head 242D in the overlapping range R is close to the end side of the downstream recording head 242D. It is determined to be larger.
Note that the recording element 243 that performs the output operation is closer to the end portion side of the upstream recording head 242U in the overlap range R as the distance in the X direction of the position where the output operation is performed by the recording element 243 of the upstream recording head 242U is closer. It may be determined to be larger.

  As described above, in the ink jet recording apparatus 1 according to the second modification, the CPU 41 outputs the recording element 243 of one of the pair of recording heads 242 within the overlapping range R for each predetermined number of recording controls. The recording element 243 that performs the output operation is selected such that the interval in the X direction of the position where the operation is performed becomes larger as it is closer to the end of the one recording head 242 (recording control means). Accordingly, complementary ejection can be performed while suppressing uneven gloss by a simple method of selecting the recording element 243 that performs the output operation at each position in the X direction.

Note that the present invention is not limited to the above-described embodiments and modifications, and various modifications can be made.
For example, in the above-described embodiment and each modification, the description has been given using an example in which the positions of the recording elements 243 in the overlapping range R of the pair of recording heads 242 having the recording elements 243 in the overlapping range R coincide with each other. The X-direction positions of the recording elements 243 of the pair of recording heads 242 in the overlapping range R may be shifted. In this case, complementary ink ejection may be performed by the recording element 243 corresponding to the position in the X direction among the recording elements 243 of the pair of recording heads 242.

  In the above embodiment and each modification, the mask pattern data is applied to the image data for one line by the CPU 41, and the recording head driving unit 241 drives the recording element 243 according to the mask image data obtained sequentially. Although an example in which a waveform voltage signal is supplied has been described, the present invention is not limited to this. For example, the control unit 40 repeatedly executes the operation of applying the mask pattern data to a part of the image data with respect to the entire image data to generate mask image data corresponding to the entire image data and stores it in the storage unit 44. It may be a mode of memorizing. Alternatively, the external device 2 may generate mask image data and supply the mask image data to the control unit 40 via the input / output interface 52.

  Further, in the above embodiment and each modification, the entire range in the X direction of the overlapping range R is set as a connection range, and an output operation is continuously performed over a predetermined number of recording controls by each recording element 243 in the connection range. However, the present invention is not limited to this. For example, in the overlapping range R, the downstream printing rate is set to 0 at a part on the end side of the downstream recording head 242D, and the output operation is performed only by the recording elements 243 of the upstream recording head 242U. The range may be the connection range. Further, in the overlapping range R, the downstream printing rate is set to 1 at a part on the opposite side to the end side of the downstream recording head 242D, and the output operation is performed only by the downstream recording head 242D. The range may be the connection range. Further, in the overlapping range R, the downstream printing rate is set to 0 in a part on the end side of the downstream recording head 242D, the downstream printing rate is set to 1 in a part on the opposite side to the end side, and the overlapping range R The remaining range may be the connection range.

  In the embodiment and the modification described above, the example in which the operating rate related to each recording head 242 increases or decreases monotonously in the X direction in the overlapping range R has been described. However, the operating rate is constant in the overlapping range R. Or may be set so as to change in a manner other than monotonous increase and monotonic decrease.

  Further, in the above-described embodiment and each modified example, the example using the ink that changes in a gel state or a sol state depending on the temperature has been described. However, the present invention is not limited to this, and the recording is performed after landing on the recording medium P. Various inks that solidify on the medium P can be used.

  Further, in the above-described embodiment and each modified example, the example in which the ink is cured by being irradiated with light such as ultraviolet rays from the fixing unit 25 and is fixed on the recording medium P has been described. Absent. For example, an ink having a thermosetting property may be used, and the ink may be heated and cured by irradiating infrared rays (heat rays) as energy rays from the fixing unit 25 and fixed on the recording medium P. good.

  In the above-described embodiment and each modification, the conveyance drum 21 has been described as an example of the moving unit. However, the present invention is not limited to this. The moving means has, for example, a belt that is supported by two rollers and moves with respect to the rollers by circling around the two rollers according to the rotation of the rollers, and a recording medium is provided on the conveying surface of the belt. P may be placed.

  Further, in the above-described embodiment and each modification, the inkjet recording apparatus 1 that records an image with a line head in which the recording elements 243 are arranged over the recording range of the image in the X direction on the recording medium P has been described as an example. However, the present invention may be applied to an ink jet recording apparatus that records an image while scanning the recording head. In this case, the moving means is constituted by a mechanism for scanning the recording head.

  Although several embodiments of the present invention have been described, the scope of the present invention is not limited to the above-described embodiments, and includes the scope of the invention described in the claims and equivalents thereof. .

DESCRIPTION OF SYMBOLS 1 Inkjet recording apparatus 2 External apparatus 10 Paper feed part 11 Paper feed tray 12 Medium supply part 20 Image recording part 21 Conveying drum 22 Delivery unit 23 Heating part 24 Head unit 241 Recording head drive part 242 Recording head 242D Downstream recording head 242U, 242Ua, 242Ub Upstream recording head 243 Recording element 243p Recording element pair 244 Ink heating unit 25 Fixing unit 26 Delivery unit 30 Paper discharge unit 31 Paper discharge tray 40 Control unit 41 CPU
42 RAM
43 ROM
44 Storage 51 Transport Drive 52 Input / Output Interface 53 Buses Ia, Ib Ink P Recording Medium R Overlap Range

Claims (9)

Recording means for ejecting ink that changes in phase from a liquid to a solid by being cooled on the recording medium from a plurality of recording elements each provided in a plurality of recording heads in a liquid state ;
Moving means for relatively moving a recording medium and the plurality of recording heads;
Each of the plurality of recording elements provided in the plurality of recording heads of the recording unit causes ink to be ejected to the recording medium that relatively moves in a predetermined movement direction according to the pixel value of image data. Or recording control means for performing recording control for performing an output operation without causing ink to be ejected corresponding to one line of the image data ;
With
The plurality of recording elements are provided at predetermined intervals in the width direction orthogonal to the one moving direction in each of the plurality of recording heads,
Each of the plurality of recording heads overlaps with the other recording head in the width direction in a range near a predetermined end, and is disposed at a different position with respect to the one recording head and the one movement direction,
In the recording control, the recording control unit is configured to perform upstream recording in the one movement direction of the pair of overlapping recording heads with respect to the same position in the one movement direction of the recording medium. After performing the output operation by the recording element of the head, a time difference corresponding to the distance in the one moving direction between the downstream recording head and the upstream recording head of the pair of recording heads is provided. Causing the recording element of the downstream recording head to perform the output operation;
The ink ejected from the recording element of the upstream recording head and landed at one position in the one moving direction on the recording medium is transferred from the recording element of the downstream recording head to the recording medium. Phase change to solid before ink is ejected and landed at the one position,
The recording control means includes
In each position in the width direction in the end portion vicinity range, it performs the recording control to either of the respective belonging recording elements in the recording head prior Symbol a pair perform the output operation,
Prior Kitan unit neighborhood range, at each position in the width direction, more complementarily the output operation to the recording element of the pair of recording heads for different positions on the one movement direction of the recording medium Determine the setting range in the width direction to be performed,
In the above setting range, the continuous in a plurality of the recording control performed continuously in response to a plurality of lines of the image data, by a predetermined number of operations of two or more of the same of the recording elements, respectively at each position in the width direction And performing the output operation.   The recording control means has an operation rate, which is a ratio at which the output operation is performed by a recording element of one recording head of the pair of recording heads, from an end portion in the vicinity of the end portion of the one recording head. 2. The ink jet recording apparatus according to claim 1, wherein a recording element that performs the output operation is selected so as to monotonously increase in the vicinity of the end as the distance increases. The recording control means determines the operating rate for each position in the width direction within the range near the end, and selects whether to cause each of the recording elements to perform the output operation according to the operating rate. The ink jet recording apparatus according to claim 2, wherein:   The recording control means determines the operation rate for each of a plurality of ranges obtained by dividing the set range in the width direction, and performs the output operation according to the operation rate for each of the plurality of ranges. The inkjet recording apparatus according to claim 2, wherein the selection is made for each predetermined number of times of the recording control.   The recording control means is arranged in the width direction at a position where the output operation is performed by the recording element of one of the pair of recording heads within the vicinity of the end portion for each predetermined number of recording controls. 3. The ink jet recording apparatus according to claim 2, wherein the recording element that performs the output operation is selected so that the interval becomes closer to the end of the one recording head.   The inkjet recording apparatus according to any one of claims 1 to 3, wherein the predetermined number of operations is determined to be different from each other at positions adjacent in the width direction within the set range.   4. The recording control unit according to claim 1, wherein the recording control unit changes the timing for switching the recording element that performs the output operation at each of the positions adjacent in the width direction within the setting range. The ink jet recording apparatus according to one item.   8. The predetermined number of operations is determined according to the number of the recording elements provided in the setting range in each of the pair of recording heads. Inkjet recording device. Recording means for ejecting ink that changes in phase from a liquid to a solid by being cooled on the recording medium from a plurality of recording elements respectively provided on a plurality of recording heads, and the recording medium And a moving means for relatively moving the plurality of recording heads, and an ink jet recording method using an ink jet recording apparatus,
Each of the plurality of recording elements provided in the plurality of recording heads of the recording unit causes ink to be ejected to the recording medium that relatively moves in a predetermined movement direction according to the pixel value of image data. Or a recording step of performing recording control for performing an output operation without ejecting ink corresponding to one line of the image data ,
The plurality of recording elements of the inkjet recording apparatus are provided at predetermined intervals in the width direction orthogonal to the one movement direction in the plurality of recording heads, respectively.
Each of the plurality of recording heads of the ink jet recording apparatus overlaps with the other recording head in the width direction in a range near a predetermined end, and is different from the one recording head with respect to the one moving direction. Placed in
In the recording step, in the recording control, the upstream recording head in the one moving direction of the pair of overlapping recording heads with respect to the same position in the one moving direction of the recording medium. After performing the output operation by the recording element, the time difference corresponding to the distance in the one moving direction between the downstream recording head and the upstream recording head of the pair of recording heads is provided. Causing the recording element of the downstream recording head to perform the output operation;
The ink ejected from the recording element of the upstream recording head and landed at one position in the one moving direction on the recording medium is transferred from the recording element of the downstream recording head to the recording medium. Phase change to solid before ink is ejected and landed at the one position,
In the recording step,
In each position in the width direction in the end portion vicinity range, it performs the recording control to either of the respective belonging recording elements in the recording head prior Symbol a pair perform the output operation,
Prior Kitan portion near range, at each position in the width direction, more complementarily the output operation to the recording element of the pair of recording heads for different positions on the one movement direction of the recording medium Determine the setting range in the width direction to be performed,
In the above setting range, the continuous in a plurality of the recording control performed continuously in response to a plurality of lines of the image data, by a predetermined number of operations of two or more of the same of the recording elements, respectively at each position in the width direction And performing the output operation.

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