JP7006313B2 - Inkjet recording device - Google Patents

Description

The present invention relates to an inkjet recording device.

Conventionally, there is an inkjet recording device that records an image or the like by ejecting ink from a nozzle provided in the ink ejection unit and landing it at a desired position on a recording medium conveyed by the conveying unit. As one of the inkjet recording devices, a plurality of ink ejection units for ejecting inks of different colors are provided at different positions in the transport direction of the recording medium, and each ink ejection unit is appropriate for the conveyed recording medium. There are some that can record a color image by ejecting ink at various timings.

In such an inkjet recording device, in addition to the ink ejection unit that ejects inks of yellow, magenta, cyan, and black, which are process colors (basic colors), a special color ink having a hue different from that of yellow, magenta, and cyan is ejected. A technique for improving the color reproducibility of a recorded image is known by further providing an ink ejection unit to record an image in which at least one of yellow, magenta, and cyan and the spot color are mixed. (For example, Patent Document 1). Here, in order to mix a plurality of colors, it is necessary to land the inks of the colors to be mixed within a predetermined neighborhood range on the recording medium.

Japanese Unexamined Patent Publication No. 2005-88207

However, in the above-mentioned inkjet recording apparatus, as the recording medium is conveyed, the position of the recording medium may be displaced in the width direction orthogonal to the conveying direction (for example, the recording medium may be skewed). be. Here, the relative displacement amount in the width direction of the recording medium between two points different in the transport direction tends to increase as the distance between the two points increases.

When such a misalignment occurs in the recording medium, the landing position of the ink in the width direction on the recording medium also deviates, so that the desired color mixing is not achieved between the inks ejected from the plurality of ink ejection portions. , Leads to the occurrence of color shift in the recorded image. In particular, in an inkjet recording device using special color ink, the larger the number of colors of the ink used, that is, the larger the number of ink ejection portions, the larger the arrangement range of the plurality of ink ejection portions in the transport direction. Therefore, there is a problem that the landing position shift in the width direction of the ink tends to be large between the ink ejection portions having a large arrangement interval in the transport direction, and the color shift due to the landing position shift tends to be remarkable.

An object of the present invention is to provide an inkjet recording apparatus capable of suppressing color shift in a recorded image.

In order to achieve the above object, the invention of the inkjet recording apparatus according to claim 1 is
At least one of yellow, magenta, and cyan and the spot color were mixed using a basic color ink consisting of yellow, magenta, cyan, and black, and a spot color ink having a hue different from that of yellow, magenta, and cyan. An inkjet recording device capable of recording an image including a portion on a recording medium.
A transport unit that transports recording media and
For the recording medium transported by the transport unit, inks of one color different from each other among the basic colors, the first spot color, and the second spot color having a hue different from that of the first spot color are applied. Multiple ink ejection parts to eject, and
Equipped with
The first spot color and the second spot color belong to different hue ranges among the three hue ranges divided by the positions of the hues corresponding to yellow, magenta, and cyan in the color wheel.
Each of the plurality of ink ejection portions is provided at a position different from each other in the transport direction of the recording medium by the transport section.
The first ink ejection unit that ejects the ink of the first special color among the plurality of ink ejection portions is an ink that ejects yellow, magenta, and cyan inks among the plurality of ink ejection portions in the transport direction. It is located outside the discharge range, and is located outside the discharge range.
Of the plurality of ink ejection portions, the second ink ejection portion that ejects the ink of the second spot color is arranged on the side opposite to the first ink ejection portion side of the arrangement range in the transport direction. There is.

The invention according to claim 2 is the inkjet recording apparatus according to claim 1.
The first spot color belongs to the hue range in which both ends are hues corresponding to yellow and magenta.
The second spot color belongs to the hue range in which both ends correspond to magenta and cyan.

The invention according to claim 3 is the inkjet recording apparatus according to claim 2.
The first feature is orange and the second feature is blue.

The invention according to claim 4 is the inkjet recording apparatus according to claim 2.
The first feature is red and the second feature is violet.

The invention according to claim 5 is the inkjet recording apparatus according to any one of claims 1 to 4.
Among yellow, magenta, and cyan, the ink ejection unit that ejects ink having a hue different from the hue at both ends of the hue range to which the first spot color belongs is the first in the arrangement range in the transport direction. It is provided at the position farthest from the ink ejection part of 1.
Among yellow, magenta, and cyan, the ink ejection unit that ejects ink having a hue different from the hue at both ends of the hue range to which the second spot color belongs is the first in the arrangement range in the transport direction. It is provided at the position farthest from the ink ejection portion of 2.

The invention according to claim 6 is the inkjet recording apparatus according to any one of claims 2 to 4.
The ink ejection portion for ejecting cyan ink is provided at a position farthest from the first ink ejection portion in the transport direction in the arrangement range.
The ink ejection portion for ejecting yellow ink is provided at a position farthest from the second ink ejection portion in the transport direction in the arrangement range.

The invention according to claim 7 is the inkjet recording apparatus according to any one of claims 1 to 6.
The plurality of ink ejection units include a third ink ejection unit that ejects ink of the first spot color and a third spot color having a hue different from that of the second spot color.
The third spot color belongs to the hue range to which a predetermined spot color, which is one of the first spot color and the second spot color, belongs.
The third ink ejection unit is provided at a position adjacent to the ink ejection unit that ejects ink of the predetermined special color in the transport direction.

The invention according to claim 8 is the inkjet recording apparatus according to any one of claims 1 to 7.
The recording medium is cloth.

According to the present invention, there is an effect that color shift in a recorded image can be suppressed.

It is a figure which shows the schematic structure of the inkjet recording apparatus. It is a schematic diagram which shows the structure of a head unit. It is a block diagram which shows the main functional composition of an inkjet recording apparatus. It is a figure which shows the arrangement order of a head unit. It is a figure which shows the position in the color wheel of the color of ink. It is a figure which shows another example of the arrangement order of a head unit. It is a figure which shows the position in the hue circle of the color of ink in the modification 1. FIG. It is a figure which shows the arrangement order of the head unit in the modification 1. FIG. It is a figure which shows the arrangement order of the head unit in the modification 2.

Hereinafter, embodiments of the inkjet recording apparatus of the present invention will be described with reference to the drawings.

FIG. 1 is a diagram showing a schematic configuration of an inkjet recording apparatus 1 according to an embodiment of the present invention.
The inkjet recording device 1 includes a transport unit 10, a recording unit 20, a control unit 30, and the like.

The transport unit 10 includes a drive roller 11, a driven roller 12, a transport belt 13 (convey member), a transport motor 14, a rotary encoder 15, a pressing roller 16, a peeling roller 17, and the like.
The drive roller 11 rotates about the axis of rotation by the drive of the transfer motor 14. The transport belt 13 is a ring-shaped belt whose inside is supported by a drive roller 11 and a driven roller 12 (hereinafter, collectively referred to as a transport roller), and rotates orbits as the drive roller 11 rotates. The driven roller 12 rotates about a rotation axis parallel to the rotation axis of the drive roller 11 as the conveyor belt 13 orbits moves. As the transport belt 13, a material that flexibly bends at the contact surface with the transport roller and reliably supports the recording medium M is used. For example, a resin belt such as rubber, a steel belt, or the like is used. be able to. Since the transport belt 13 has a material and / or a configuration in which the recording medium M is adsorbed, the recording medium M can be more stably mounted on the transport belt 13.

The conveyor motor 14 rotates the drive roller 11 at a rotation speed according to a control signal from the control unit 30. The transport motor 14 can also rotate the drive roller 11 in the direction opposite to the normal transport direction. The transport unit 10 transports the recording medium M by rotating the transport belt 13 at a speed corresponding to the rotation speed of the drive roller 11 in a state where the recording medium M is placed on the transport surface of the transport belt 13. A transport operation for transporting in the moving direction (transporting direction) of 13 is performed.
The recording medium M may be conveyed intermittently, for example, by suspending the ink ejection unit 10 for a period of time. The transport operation by the transport unit 10 shall include an operation of suspending the transport as described above.

In this embodiment, a cloth is used as the recording medium M. The recording medium M is unwound (unwound) from the roll (recording medium unwinding portion) around which the recording medium M is wound, and is supplied onto the transport belt 13. The transport unit 10 of the present embodiment is configured to be capable of transporting a recording medium M having a width of about 2 m in the width direction orthogonal to the transport direction and a length of about 4000 m in the entire roll. The recording medium M having a width smaller than 2 m in the width direction may be conveyed by the conveying unit 10. Further, the transport unit 10 may be configured to be capable of transporting the recording medium M having a width in the width direction larger than 2 m, and the transport unit 10 may be configured to be capable of transporting the recording medium M having a width in the width direction smaller than 2 m. It may have been done.
The recording medium M is not limited to the above-mentioned cloth, and various media such as paper and sheet-shaped resin capable of fixing the ejected ink to the surface can be used. Further, instead of the long recording medium M unwound from the roll, a short recording medium M such as a sheet of paper may be used.

The rotary encoder 15 outputs a pulse signal (detection signal) to the control unit 30 and the head control unit 24 (FIG. 3) each time the drive roller 11 rotates by a predetermined angle. The configuration of the rotary encoder 15 is not particularly limited, but for example, a chord wheel provided with a plurality of slits arranged on a predetermined circumference and rotating together with the drive roller 11 and the slits of the chord wheel are irradiated with light. The light emitting unit and the light receiving unit for detecting the light emitted from the light emitting unit and passing through the slit are provided, and the pulse signal based on the light detection result by the light receiving unit is output to the control unit 30 and the head control unit 24. be able to. Here, the pulse signal is output, for example, at the rising and falling timings of each of the two squares (A phase and B phase) having the same period as the light receiving period of the light passing through the slit and different in phase by 90 degrees. Can be done. In such a configuration, the rotation direction of the drive roller 11 can be detected by the phases of the A phase and the B phase.

The pressing roller 16 presses the recording medium M supplied to the transport surface of the transport belt 13 against the transport surface to remove floating from the transport surface such as wrinkles.
The peeling roller 17 pulls the recording medium M transported in a state of being adsorbed on the transport belt 13 with a predetermined pressure, thereby peeling the recording medium M from the transport surface and sending it to a post-processing device (not shown). In the present embodiment, as the post-processing device, a drying device that dries the recording medium M on which the image is recorded, a device that steams the recording medium M to improve color development and fix the ink, a stain or non-stick ink, and the like. A cleaning device for washing off the ink, a cutting device for cutting the recording medium M at a predetermined position, and the like are provided.

The recording unit 20 includes six head units 21 (ink ejection units). Each head unit 21 has a plurality of recording elements that each perform an ink ejection operation for ejecting ink based on image data, and the plurality of recording elements perform the ink ejection operation to be conveyed by the conveying unit 10. An image recording operation for recording an image on the recording medium M is performed. Each of the six head units 21 ejects inks of different colors from each other. Specifically, each head unit 21 has one of the six colors of yellow (Y), magenta (M), cyan (C), black (K), orange (O), and blue (B), which are different from each other. Is discharged.

Of these six colors, four colors consist of three primary colors (Y, M, and C) used for color expression by subtractive color mixing, and black (K), which is difficult to actually obtain by superimposing the three primary colors. Is called a process color (basic color), and is a combination of basic colors used for recording an image by various image forming devices such as an inkjet recording device.
Further, O and B are colors having different hues from Y, M and C among the process colors, and are called spot colors. In the present embodiment, the spot color is used to express a color different from the process color by mixing with at least one of Y, M and C among the process colors.
As described above, in the inkjet recording apparatus 1 of the present embodiment, by using the process color ink and the O (first spot color) and B (second spot color) inks, the process colors can be mixed. In addition to the colors to be obtained, it is possible to express a color obtained by mixing at least one of Y, M and C with O or B.
Here, the color mixing in the image formation by the inkjet recording apparatus 1 is the observation of the recording medium M (from a normal microscopic viewpoint) by landing inks of different colors within a predetermined neighborhood range on the recording medium M. It is expressed to the person by using the effect that the different colors appear to be a mixture of the different colors. Therefore, it is not always necessary to eject the ink so that the inks in the liquid state are united on the recording medium M, and the inks of different colors landed at close positions (or at least partially overlapping positions) are separate from each other. Ink may be ejected in a mode of solidifying at the timing of (that is, in a mode of not coalescing in a liquid state).

Further, in the present embodiment, a reactive dye ink preferably used for a recording medium M such as a natural fiber such as cotton or linen is used. The reactive dye ink can be covalently bonded to the molecules of the recording medium by steaming (heating and humidifying) after being ejected to the recording medium M, and the recording medium M can be colored in a stable state.

The six head units 21 are arranged at positions different from each other in the transport direction of the recording medium M at predetermined intervals. In such a configuration, each head unit 21 forms an image corresponding to the color of the ink ejected from the recording element, and the inkjet recording device 1 records images of Y, M, C, K, O, and B as a recording medium. A color image to be recorded is recorded by superimposing and recording on the same area on M.
The arrangement order of the six head units 21 will be described in detail later.

FIG. 2 is a schematic diagram showing the configuration of the head unit 21. FIG. 2 shows a plan view of the entire head unit 21 as viewed from the side of the transport belt 13 facing the transport surface.
The head unit 21 includes 54 recording heads 22 each provided with a plurality of recording elements for ejecting ink. In each recording head 22, recording elements are arranged so as to be continuous over a width of about 72 mm in the width direction. The recording element provided in the recording head 22 has a pressure chamber for storing ink, a piezoelectric element provided on the wall surface of the pressure chamber, and a nozzle 23, respectively. When a drive signal for deforming the piezoelectric element is input to this recording element, the pressure chamber is deformed due to the deformation of the piezoelectric element, the pressure in the pressure chamber changes, and ink is ejected from the nozzle 23 communicating with the pressure chamber. .. FIG. 2 shows the position of the ink ejection port of the nozzle 23 in the recording element. The arrangement direction of the recording elements in each recording head 22 is not limited to the width direction orthogonal to the transport direction, and may be a direction intersecting the transport direction at an angle other than a right angle.

In the head unit 21, the head module 22M is composed of two recording heads 22 arranged adjacent to each other in the transport direction in such a positional relationship that the nozzles 23 of the recording elements are alternately arranged in the width direction. Further, in the head unit 21, the 27 head modules 22M have a positional relationship in which the range in which ink can be ejected from the nozzle 23 is continuously connected over the image recording width (about 2 m) in the width direction. The line heads are arranged in a houndstooth pattern so that the arrangement ranges in the width direction partially overlap each other. The head unit 21 is used with a fixed position when recording an image, and ink is sequentially ejected at predetermined intervals to positions different in the transport direction according to the transport of the recording medium M, thereby forming an image in a single pass method. To record. The number of head modules 22M (hence, the number of recording heads 22) can be appropriately changed according to the length of the recording medium M in the width direction and the like.

FIG. 3 is a block diagram showing a main functional configuration of the inkjet recording device 1.
The inkjet recording device 1 includes a transfer drive unit 101 and a rotary encoder 15 provided in the transfer unit 10, a head control unit 24 and a head drive unit 221 provided in the head unit 21, a control unit 30, and an image processing unit 41. The operation display unit 42, the input / output interface 43, the bus 44, and the like are provided.

The transfer drive unit 101 supplies a drive signal to the transfer motor 14 based on the control signal supplied from the control unit 30 to rotate the drive roller 11 at a predetermined rotation speed, whereby the transfer belt 13 is moved at a predetermined movement speed. Move with.

The head control unit 24 outputs various control signals and image data to the head drive unit 221 at an appropriate timing according to the count number of the control signal from the control unit 30 and the pulse signal input from the rotary encoder 15. do.
The head drive unit 221 supplies a drive signal for deforming the piezoelectric element to the recording element of the recording head 22 according to the control signal and image data input from the head control unit 24, and from the opening of each nozzle 23. Discharge ink.

The control unit 30 includes a CPU 31 (Central Processing Unit), a RAM 32 (Random Access Memory), a ROM 33 (Read Only Memory), and a storage unit 34.

The CPU 31 reads out various control programs and setting data stored in the ROM 33 and stores them in the RAM 32, and executes the program to perform various arithmetic processes. Further, the CPU 31 comprehensively controls the overall operation of the inkjet recording device 1.

The RAM 32 provides a working memory space to the CPU 31 and stores temporary data. The RAM 32 may include a non-volatile memory.

The ROM 33 stores various control programs, setting data, and the like executed by the CPU 31. Instead of the ROM 33, a rewritable non-volatile memory such as an EEPROM (Electrically Erasable Programmable Read Only Memory) or a flash memory may be used.

The storage unit 34 stores a print job (image recording command) input from the external device 2 via the input / output interface 43 and image data related to the print job. As the storage unit 34, for example, an HDD (Hard Disk Drive) may be used, or a DRAM (Dynamic Random Access Memory) or the like may be used in combination.

Under the control of the control unit 30, the image processing unit 41 performs predetermined image processing on the image data stored in the storage unit 34, and stores the image data after the image processing in the storage unit 34. The image processing performed by the image processing unit 41 includes rasterization processing for converting PDL (Page Description Language) data input from the external device 2 and stored in the storage unit 34 into raster format image data, and R, G, and B colors. There are color conversion processing for converting image data of components into image data of each color component of C, M, Y, K, O, B, halftone processing for image data, and the like. The image data of C, M, Y, K, O, and B generated in this way is supplied to the head unit 21 corresponding to the ink color among the six head units 21, and is supplied to the control unit 30 and the head control unit 24. The ink ejection operation is performed based on the supplied image data under the control of.
The image processing unit 41 may not be provided, and the control unit 30 may perform the above-mentioned various image processing. Further, the various image processing may be performed by the external device 2 provided outside the inkjet recording device 1, and the processed image data may be stored in the storage unit 34.

The operation display unit 42 includes a display device such as a liquid crystal display or an organic EL display, and an input device such as an operation key and a touch panel arranged on the screen of the display device. The operation display unit 42 displays various information on the display device, converts the user's input operation to the input device into an operation signal, and outputs it to the control unit 30.

The input / output interface 43 mediates the transmission / reception of data between the external device 2 and the control unit 30. The input / output interface 43 is composed of, for example, various serial interfaces, various parallel interfaces, or a combination thereof.

The bus 44 is a path for transmitting and receiving signals between the control unit 30 and other configurations.

The external device 2 is, for example, a personal computer, and supplies print jobs, image data, and the like to the control unit 30 via the input / output interface 43.

The components of the inkjet recording device 1 are not limited to the above, and other components may be provided as needed. For example, a sensor (abnormality detection unit) may be provided on the upstream side of the head unit 21 in the transport direction to detect mounting abnormalities such as floating of the recording medium M and foreign matter adhering to the recording medium M.

Next, the arrangement order of the six head units 21 will be described.
FIG. 4 is a diagram showing the arrangement order of the head units 21 in the present embodiment. In this figure, the arrangement positions of the six head units 21 in the transport direction (P1 to P6 are sequentially referred to from the upstream side in the transport direction) and the colors of the ink ejected by the head units 21 arranged at the respective arrangement positions P1 to P6. The relationship with is shown. As shown in FIG. 4, in the present embodiment, the head units 21 for ejecting inks of O, Y, M, K, C, and B are arranged in this order from the upstream side in the transport direction.
By arranging the head units 21 in such an order, it is possible to suppress the occurrence of color shift in the recorded image. The reason will be explained below.

In the inkjet recording apparatus 1, if the inks of different colors ejected from the separate head units 21 are not landed at the desired positions, the different colors are not properly mixed and the colors in the recorded image are not properly mixed. It leads to the occurrence of deviation.
Specifically, in the inkjet recording apparatus 1 of the present embodiment, when the transport belt 13 is meandering, a positional shift in the width direction of the recording medium M occurs between different positions in the transport direction (that is, recording). The medium M is skewed), and the landing positions of the inks ejected from the separate head units 21 in the width direction are relatively displaced, and the above-mentioned color shift occurs. The meandering of the transport belt 13 occurs because the contact range of the transport belt 13 in the transport roller shifts in the width direction due to an imbalance in the distribution of the force received by the transport belt 13 from the transport roller in the width direction. ..
When the recording medium M is skewed due to meandering of the transport belt 13, the amount of misalignment in the width direction of the recording medium M tends to increase as the distance between the two points in the transport direction is large. .. Therefore, among the six head units 21, the ink ejected from each of the head units 21 having a larger arrangement interval in the transport direction is more likely to have a landing position in the width direction, which is likely to lead to color shift in the recorded image.

On the other hand, the six colors of ink used in the inkjet recording apparatus 1 also have color combinations that are used without mixing each other, and even if the ink landing positions are misaligned between the colors of these combinations, recording is performed. It does not lead to color shift in the image. What kind of colors are used without being mixed can be explained based on the relative relationship of hues in the color wheel.

FIG. 5 is a diagram showing positions in the color wheel of the colors of the inks ejected from the six head units 21.
Here, the hue circle is formed by arranging hues, which are one of the three elements of color, in an annular shape in an order in which they are continuously changed and perceived. In the color wheel of FIG. 5, Y, R (red), M, B, C, and G (green) are arranged clockwise at intervals of 60 degrees in this order. In the following, in the hue circle, the three ranges divided by the positions of the hues corresponding to Y, M, and C are referred to as hue ranges A1 to A3. Of these, the hue range A1 is a range divided by the positions of the hues corresponding to Y and M, the hue range A2 is a range divided by the positions of the hues corresponding to M and C, and the hue range A3 is. , C and Y are the ranges divided by the position of the hue corresponding to.

Of the spot colors used in the inkjet recording apparatus 1 of the present embodiment, O belongs to the hue range A1 and B belongs to the hue range A2 different from O.
In the reactive dye ink used in the present embodiment, it is easy to prepare an ink having an orange hue in the hue range A1 due to the color of the dye that can be used for the reactive dye ink, and the hue range A2. Ink with a blue hue is easy to prepare. Therefore, in this embodiment, O and B are used as two features.
Here, orange used as a spot color is, for example, a color whose hue is in the range of 7.5R to 7.5YR in the Munsell hue circle. Further, blue used as a spot color is, for example, a color whose hue is in the range of 7.5B to 7.5PB in the Munsell hue circle.

In the recording of an image by the inkjet recording apparatus 1, a spot color belonging to a certain hue range in the hue circle is a process color corresponding to the hues at both ends of the hue range to which the spot color belongs (hereinafter, referred to as "nearby process color" for convenience). While it is used by mixing colors with, usually, it is not mixed with a process color having a hue different from the hues at both ends of the hue range to which the spot color belongs (hereinafter, referred to as "opposite process color" for convenience). Use. This is because when the spot color and the opposite process color are mixed, the color becomes close to an achromatic color, which does not contribute to the improvement of the color reproducibility of the recorded image by the color mixing.
Specifically, among the spot colors of the present embodiment, O is used by being mixed with Y and M, which are neighboring process colors for O, while being used without being mixed with C, which is the opposite process color. Similarly, B is used mixed with M and C, which are neighboring process colors for B, but not mixed with Y, which is the opposite process color.

Further, in the recording of an image by the inkjet recording apparatus 1, spot colors belonging to different hue ranges are also used without being mixed. This is for the same reason that spot colors and opposite process colors are not mixed. Therefore, the two characteristics of this embodiment, O and B, are used without being mixed with each other.

In the color conversion process by the image processing unit 41 described above, each image data of C, M, Y, K, O, and B is generated so that the above-mentioned condition relating to the possibility of color mixing is satisfied. Specifically, in each of the image data of O and C that are not mixed with each other, the pixels corresponding to the ink ejection (on-pixel) are in a positional relationship so that the inks of O and C are not ejected in the recognized neighborhood range. ) Is placed. Similarly, in the combination of the image data of B and Y, O and B, the on-pixels are arranged in the same positional relationship.

As shown in FIG. 4, in the inkjet recording apparatus 1 of the present embodiment, the head unit 21 that discharges two spot colors (O and B) that are not used by mixing colors with each other has both ends (P1, P6) in the transport direction. ) Is placed. That is, the head unit 21O (first ink ejection unit) that ejects the ink of O among the two characteristics has the arrangement range of the head units 21Y, 21M, and 21C that eject the inks of Y, M, and C in the transport direction. The head unit 21B (second ink ejection unit) that is arranged outside the head unit 21B (second ink ejection unit) that ejects the ink of B out of the two features is the head unit 21O side of the arrangement range of the head units 21Y, 21M, and 21C in the transport direction. It is located on the other side.
As a result, the O and B inks that are not mixed are ejected from the head units 21 at the upstream end and the downstream end in the transport direction, where the ink landing position shift in the width direction becomes large. Even if the ink ejected from the head unit 21 shifts in the landing position in the width direction due to the meandering of the belt 13, it does not lead to the color shift in the recorded image.
Further, as a result of such an arrangement, the head units 21Y, 21M, and 21C that eject inks of Y, M, and C that are frequently mixed can be arranged so as to be close to each other (P2, P3, P5). ). Therefore, it is possible to reduce the landing position shift in the width direction for the process color inks that are mixed with each other, and it is possible to suppress the color shift in the recorded image.

Further, the head unit 21C that ejects the ink of C, which is the opposite process color for O of the two spot colors, is located from the position (P1) of the head unit 21O in the transport direction in the arrangement range of the head units 21Y, 21M and 21C. It is provided at the farthest position (P5).
Further, the head unit 21Y that ejects the ink of Y, which is the opposite process color for B among the two spot colors, is located from the position (P6) of the head unit 21B in the transport direction in the arrangement range of the head units 21Y, 21M and 21C. It is provided at the farthest position (P2).
As a result, inks of spot colors and opposite process colors that are not mixed are ejected from the head unit 21 having a large positional relationship in the transport direction. Therefore, the meandering of the transport belt 13 causes these heads. Even if the landing position shift of the ink ejected from the unit 21 in the width direction occurs, it does not lead to the color shift in the recorded image.
Further, as a result of such an arrangement, the head unit 21 that ejects the special color ink and the head unit 21 that ejects the ink of the neighboring process color to be mixed with the special color can be relatively close to each other. Specifically, the head units 21O, 21Y, and 21M that eject the inks of O, Y, and M that are mixed with each other can be placed close to each other (P1 to P3), and B, which is used by mixing the colors with each other. The arrangement positions of the head units 21B, 21C, and 21M for ejecting the inks of C and M can be brought close to each other (P3, P5, P6). Therefore, it is possible to reduce the landing position shift in the width direction for the spot color and process color inks that are mixed with each other, and it is possible to suppress the color shift in the recorded image.

As shown in FIG. 6, the arrangement order of the six head units 21 may be reversed from that in FIG. Even with such an arrangement order, the same color shift suppressing effect as in FIG. 4 can be obtained.

(Modification 1)
Next, a modification 1 of the above embodiment will be described. In this modification, the spot color used is different from that of the above embodiment. Hereinafter, the differences from the above-described embodiment will be described.
In this modification, a disperse dye ink in which the dye is dispersed in the ink is used. Disperse dye inks are preferably used for chemical dyes such as polyester and acetate.
Further, in this modification, red (R) and violet (V) are used as special colors.

FIG. 7 is a diagram showing positions in the color wheel of the colors of ink ejected from the six head units 21 of this modification. As shown in this figure, among the features used in this modification, R belongs to the same hue range A1 as O in the above embodiment, and V belongs to the same hue range A2 as B in the above embodiment. belong to. Therefore, for the same reason as in the above embodiment, R among the special colors of this modification is used in a mixed color with Y and M, but is used without being mixed with C. Further, V is used by being mixed with M and C, while it is used without being mixed with Y. Further, the special colors of R and V are used without being mixed.

In the disperse dye ink, it is easy to prepare an ink having a red hue in the hue range A1 due to the color of the dye that can be used in the disperse dye ink, and a violet hue is produced in the hue range A2. It is easy to prepare the ink of the color you have. Therefore, in this embodiment, R and V are selected as the two features.
Here, red used as a spot color is, for example, a color whose hue is in the range of 7.5RP to 7.5R in the Munsell hue circle. The violet used as a spot color is, for example, a color whose hue is in the range of 7.5PB to 7.5P in the Munsell hue circle.

FIG. 8 is a diagram showing the arrangement order of the head units 21 in this modification.
In this modification, as shown in FIG. 8A, the head units 21 for ejecting inks of R, Y, M, K, C, and V are arranged in this order from the upstream side in the transport direction.
In the arrangement order of FIG. 8A, O in the arrangement order of FIG. 4 of the above embodiment is replaced with R belonging to the same hue range A1 as O, and B is replaced with V belonging to the same hue range A2 as B. Corresponds to the replaced one. With such an arrangement order, the head units 21 that eject R and V, R and C, and Y and V inks that do not mix with each other can be arranged at positions separated from each other in the transport direction. Therefore, even if the landing position of the inks of these combinations shifts due to the meandering of the transport belt 13, it does not lead to the color shift in the recorded image.
As shown in FIG. 8B, the arrangement order of the six head units 21 may be reversed from that in FIG. 8A.

(Modification 2)
Next, a modification 2 of the above embodiment will be described. In this modification, three special color inks, O, R and B, are used. Therefore, the recording unit 20 is configured to have seven head units 21 in which the head unit 21R for ejecting R ink is added to the six head units 21 of the above embodiment. Hereinafter, the differences from the above-described embodiment will be described.

FIG. 9 is a diagram showing the arrangement order of the head units 21 in this modification.
As shown in this figure, in this modification, the head units 21 for ejecting inks of R, O, Y, M, K, C, and B are arranged in this order from the upstream side in the transport direction. Of the three spot colors of this modification, O and R belong to the same hue range A1, and therefore may be used in a mixed color. Therefore, the head unit 21O and the head unit 21R for ejecting the inks of O and R are arranged at positions close to each other, that is, at positions adjacent to each other in the transport direction as shown in FIG.
The positions of the head unit 21O and the head unit 21R may be interchanged in FIG. Further, the arrangement order of the seven head units 21 may be reversed from that in FIG.

In the above, an example of using inks of three special colors of O, R, and B has been described, but the embodiment of this modification is not limited to this, and two or more of the three or more spot colors have the same hue. Any aspect belonging to the range is included in this modification. In any of these embodiments, it is desirable that the head units 21 for ejecting special color inks belonging to the same hue range are provided in a positional relationship adjacent to each other. For example, when the spot colors O, B, and V are used, the head unit 21B and the head unit 21V that eject the inks of B and V may be arranged at positions adjacent to each other.

As described above, the inkjet recording apparatus 1 according to the present embodiment contains a process color (basic color) ink composed of Y, M, C and K and a special color ink having a hue different from that of Y, M and C. An ink-ink recording apparatus 1 capable of recording an image including a portion in which at least one color of Y, M, and C is mixed with a spot color on a recording medium M, and a transport unit 10 for transporting the recording medium M. For the recording medium M transported by the transport unit 10, inks of one color different from each other among the process colors O (first spot color) and B (second spot color) having a hue different from O are respectively. A plurality of head units 21 for discharging are provided, and each spot color of O and B is in a different hue range from the three hue ranges divided by the positions of the hues corresponding to Y, M, and C in the hue circle. Each of the plurality of head units 21 is provided at different positions with respect to the transport direction of the recording medium M by the transport unit 10, and the head unit 21O (first ink) that ejects the ink of O among the plurality of head units 21 The ejection unit) is arranged outside the arrangement range of the head unit 21 that ejects the inks of Y, M, and C among the plurality of head units 21 in the transport direction, and the ink of B among the plurality of head units 21. The head unit 21B (second ink ejection unit) for ejecting ink is arranged on the side opposite to the head unit 21O side in the above arrangement range in the transport direction.

The two spot colors (O and B) in such a configuration have hues in a relationship that sandwiches at least one process color in the color wheel. The two spot colors having such a hue relationship contribute to the improvement of the color reproducibility of the recorded image by mixing the color with the process colors at both ends of the hue range to which the spot color belongs. On the other hand, even if the two spot colors are directly mixed, the effect of improving the color reproducibility is not reinforced, so that these spot colors are usually used without being mixed.
In the above configuration, the head unit 21O and the head unit 21B for ejecting such special color inks are arranged at positions sandwiching the process color head units 21Y, 21M and 21C. In this arrangement, since the distance between the head unit 21O and the head unit 21B is large, the positional deviation of the recording medium M in the width direction due to meandering of the transport belt 13 or the like tends to be large between the positions of the head units 21. .. However, since inks that do not mix colors with each other are ejected from the head unit 21O and the head unit 21B, even if the landing position of the ink in the width direction is relatively displaced due to the positional deviation of the recording medium M, the recorded image is recorded. It is possible to prevent it from leading to color shift in.
Further, in the conventional arrangement in which the head units 21 of the two special colors are collectively arranged on one side of the arrangement range of the head units 21C, 21M and 21Y of the process color, the head units 21 of the two special colors are placed between the one special color and C, M and Y. Since the head units 21 are arranged in a positional relationship in which the other spot color is sandwiched, there is a problem that the distance between the head unit 21 of the one spot color and the head units 21 of C, M, and Y becomes large. On the other hand, by arranging the head units 21O and 21B having two special colors on both sides of the arrangement range of the head units 21Y, 21M and 21C as in the above configuration, the head units 21 of C, M and Y are arranged for each special color. The interval between and can be reduced. Therefore, it is possible to reduce the deviation of the landing position in the width direction for the special color ink and the process color ink that are mixed with each other, and it is possible to suppress the color deviation in the recorded image.
Further, as a result of arranging the head unit 21O and the head unit 21B as in the above configuration, the relative distance between the head units 21Y, 21M, and 21C that eject the ink of the process color can be reduced, so that the colors are mixed with each other. , M and C inks can reduce the deviation of the landing position in the width direction, and can suppress the color deviation in the recorded image.

Further, as the first spot color, a color belonging to the hue range A1 whose both ends correspond to Y and M is used, and as the second spot color, the color belongs to the hue range A2 whose both ends correspond to the hues M and C. When a color is used, a special color reactive dye ink or disperse dye ink having the above-mentioned characteristics can be easily prepared.

When the first spot color is O and the second spot color is B, a spot color reactive dye ink having the above characteristics can be easily prepared.

When the first spot color is R and the second spot color is V, a spot color disperse dye ink having the above characteristics can be easily prepared.

Further, among Y, M and C, the head unit 21 for ejecting ink having a hue different from the hue at both ends of the hue range to which the first spot color belongs (opposite process color) is the head units 21Y, 21M and 21C. Of the arrangement range of Y, M and C, the hues at both ends of the hue range to which the second spot color belongs among Y, M and C are provided at the position farthest from the head unit 21 corresponding to the first ink ejection portion in the transport direction. The head unit 21 that ejects ink having a hue different from that of the head unit 21Y, 21M, and 21C is the most from the head unit 21 corresponding to the second ink ejection portion in the transport direction in the arrangement range of the head units 21Y, 21M, and 21C. It is installed in a distant position. Specifically, the head unit 21C for ejecting the ink of C is provided at a position farthest from the head unit 21O in the transport direction in the arrangement range of the head units 21Y, 21M and 21C, and ejects the ink of Y. The head unit 21Y is provided at a position farthest from the head unit 21B in the transport direction in the arrangement range of the head units 21Y, 21M and 21C.
Since the spot color and the opposite process color for the spot color do not reinforce the above-mentioned effect of improving color reproducibility even if they are mixed, they are usually used without being mixed with each other.
According to the above configuration, since the distance between the pair of head units 21 that eject the spot color and the ink of the opposite process color is large, the recording medium M due to the meandering of the transport belt 13 between the positions of the head units 21 is large. The positional deviation in the width direction of the is likely to be large. However, since the spot color and the opposite process color inks that are not mixed are ejected from each of these head units 21, they are relative to the landing position of the ink in the width direction due to the misalignment of the recording medium M. Even if the deviation occurs, it can be prevented from leading to the color deviation in the recorded image.
Further, as a result of arranging the pair of head units 21 for ejecting the special color and the ink of the opposite process color as described above, the head unit 21 for ejecting the special color ink and the ink of the neighboring process color to be mixed with the special color are obtained. The head unit 21 for discharging can be relatively close to each other. Therefore, it is possible to reduce the landing position shift in the width direction for the spot color and process color inks that are mixed with each other, and it is possible to suppress the color shift in the recorded image.

Further, in the inkjet recording apparatus 1 according to the second modification, the plurality of head units 21 use ink of a third spot color (R) having a hue different from that of the first spot color (O) and the second spot color (B). It has a head unit 21R for discharging, the third spot color belongs to the hue range to which a predetermined spot color which is one of the first spot color and the second spot color belongs, and the head unit 21R has the above-mentioned predetermined spot color in the transport direction. It is provided at a position adjacent to the head unit 21 for ejecting the special color ink of. According to such a configuration, it is possible to further improve the color reproducibility of the recorded image by using more spot colors while suppressing the color shift in the recorded image.

Further, when the recording medium M of the cloth is used, it is effective to mix the process color and the spot color for improving the color reproducibility. However, by applying the above configuration, the color shift is suppressed. Therefore, a desired color reproducibility improving effect can be obtained.

The present invention is not limited to the above embodiment and each modification, and various modifications can be made.
For example, the spot color is not limited to that shown in the above embodiment and each modification, and any other other color that has a different hue from Y, M, and C and is used by being mixed with at least one of Y, M, and C. A color may be used as a spot color. For example, a color (green or the like) belonging to the hue range A3 in FIG. 5 may be used.
When three spot colors belonging to different hue ranges are used, the arrangement order of the two spot colors is determined as described in the above embodiment, and the other one color is the two spot colors. It can be placed adjacent to either one.

Further, the position of the head unit 21K for ejecting K (black) ink is not limited to the position shown in the above embodiment and each modification. For example, in FIGS. 4, 6, 8, and 9, the positions of the head unit 21K and the head unit 21M may be interchanged with each other. Further, the position of the head unit 21K may be changed in the arrangement order within a range that does not affect the coloring by the inks of other colors, and may be, for example, the position of either end in the transport direction. This is because the ink of the head unit 21K (black) remains achromatic even when mixed with ink of another color, and even if there is a relative deviation in the landing position with the ink of another color. This is because it does not lead to color shift in the recorded image.

Further, the color wheel is not limited to that of the above embodiment (Y, R, M, B, C, G are arranged at intervals of 60 degrees), and Y, R such as a Mansell color wheel and a PCCS color wheel. , M, B, C, G may use other types of hue circles in which the hues corresponding to, M, B, C, and G are arranged in this order.

Further, in the above-described embodiment and each modification, the example in which the recording medium M is transported by the transport unit 10 provided with the transport belt 13 has been described, but the purpose is not limited to this, and the transport unit 10 is, for example, transporting. A transport drum may be used as a member, and the recording medium M may be held and transported on the outer peripheral surface of the rotating transport drum. Even when such a transport drum is used, misalignment in the width direction of the recording medium M may occur. Therefore, by applying the present invention, color misalignment due to misalignment of the recording medium M can be suppressed. can do.

Although some embodiments of the present invention have been described, the scope of the invention is not limited to the embodiments described above, but includes the scope of the invention described in the claims and the equivalent scope thereof. ..

1 Inkjet recording device 2 External device 10 Conveyor unit 11 Drive roller 12 Driven roller 13 Conveyance belt 14 Conveyance motor 15 Rotary encoder 16 Pressing roller 17 Roller 20 Recording unit 21 Head unit 22 Recording head 22M Head module 23 Nozzle 24 Head control unit 30 Control Part 31 CPU
32 RAM
33 ROM
34 Storage unit 41 Image processing unit 42 Operation display unit 43 Input / output interface 44 Bus A1 to A3 Hue range M Recording medium

Claims (8)

At least one of yellow, magenta, and cyan and the spot color were mixed using a basic color ink consisting of yellow, magenta, cyan, and black, and a spot color ink having a hue different from that of yellow, magenta, and cyan. An inkjet recording device capable of recording an image including a portion on a recording medium.
A transport unit that transports recording media and
For the recording medium transported by the transport unit, inks of one color different from each other among the basic colors, the first spot color, and the second spot color having a hue different from that of the first spot color are applied. Multiple ink ejection parts to eject, and
Equipped with
The first spot color and the second spot color belong to different hue ranges among the three hue ranges divided by the positions of the hues corresponding to yellow, magenta, and cyan in the color wheel.
Each of the plurality of ink ejection portions is provided at a position different from each other in the transport direction of the recording medium by the transport section.
The first ink ejection unit that ejects the ink of the first special color among the plurality of ink ejection portions is an ink that ejects yellow, magenta, and cyan inks among the plurality of ink ejection portions in the transport direction. It is located outside the discharge range, and is located outside the discharge range.
Of the plurality of ink ejection portions, the second ink ejection portion that ejects the ink of the second spot color is arranged on the side opposite to the first ink ejection portion side of the arrangement range in the transport direction. Inkjet recording device. The first spot color belongs to the hue range in which both ends are hues corresponding to yellow and magenta.
The inkjet recording apparatus according to claim 1, wherein the second spot color belongs to the hue range in which both ends correspond to magenta and cyan. The inkjet recording apparatus according to claim 2, wherein the first spot color is orange and the second spot color is blue. The inkjet recording apparatus according to claim 2, wherein the first feature is red and the second feature is violet. Among yellow, magenta, and cyan, the ink ejection unit that ejects ink having a hue different from the hue at both ends of the hue range to which the first spot color belongs is the first in the arrangement range in the transport direction. It is provided at the position farthest from the ink ejection part of 1.
Among yellow, magenta, and cyan, the ink ejection unit that ejects ink having a hue different from the hue at both ends of the hue range to which the second spot color belongs is the first in the arrangement range in the transport direction. The inkjet recording apparatus according to any one of claims 1 to 4, which is provided at a position farthest from the ink ejection portion of 2. The ink ejection portion for ejecting cyan ink is provided at a position farthest from the first ink ejection portion in the transport direction in the arrangement range.
The aspect according to any one of claims 2 to 4, wherein the ink ejection portion for ejecting yellow ink is provided at a position farthest from the second ink ejection portion in the transport direction in the arrangement range. Inkjet recording device. The plurality of ink ejection units include a third ink ejection unit that ejects ink of the first spot color and a third spot color having a hue different from that of the second spot color.
The third spot color belongs to the hue range to which a predetermined spot color, which is one of the first spot color and the second spot color, belongs.
The inkjet recording according to any one of claims 1 to 6, wherein the third ink ejection unit is provided at a position adjacent to the ink ejection unit that ejects ink of the predetermined spot color in the transport direction. Device. The inkjet recording apparatus according to any one of claims 1 to 7, wherein the recording medium is a cloth.

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