JP7243275B2 - Liquid ejection device, irradiation control method in liquid ejection device, and irradiation control program - Google Patents

Description

The present invention relates to a liquid ejection apparatus, an irradiation control method in the liquid ejection apparatus, and an irradiation control program.

In an active energy ray-curable inkjet printer that forms an image by irradiating the ink after ejecting the ink that is cured by an active energy ray, clear ink is used to add gloss to the printed image. Overcoating active energy ray coating printing technology exists.

In such active energy ray coating technology, when an overcoat layer is formed on an image, the wetting and spreading of the overcoat layer (gloss layer) differs between the areas where the transparent ink is applied and the areas where the transparent ink is not applied. The gloss of the overcoat layer is not uniform.

Therefore, in Patent Document 1, in order to make the glossiness of the overcoat layer uniform, a matte layer of clear coat is applied to a specific area based on the inverted data of the colored ink, so that the overcoat layer is wetted. Techniques for uniform spreading have been proposed.

However, the technique of Patent Document 1 requires data in which the colored ink is reversed, which takes a lot of time for data processing, and requires two or more processes including the overcoat layer after the matte layer, which increases the processing process. increase and productivity declines.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a liquid ejecting apparatus capable of forming an overcoat layer with uniform glossiness without lowering productivity.

In order to solve the above problems, in one aspect of the present invention,
a head unit in which a plurality of nozzles for ejecting an active energy ray-curable liquid onto a recording medium are provided as a nozzle row in the sub-scanning direction;
an irradiation unit that is connected to the head unit and that irradiates light of an active energy ray that hardens the liquid on the recording medium by irradiating the liquid with light;
scanning movement for moving the head unit and the irradiation section relative to the recording medium in a scanning direction perpendicular to the sub-scanning direction; a moving unit that alternately performs a sub-scanning movement that moves in the scanning direction;
an irradiation control unit that controls lighting and extinguishing by dividing the sub-scanning direction of the irradiation unit;
During at least part of the scanning movement, the head unit and the irradiation unit discharge liquid onto the recording medium and irradiate the recording medium with light;
After the liquid is ejected onto the recording medium from the plurality of nozzles, the liquid applied onto the recording medium is irradiated with light by the rear end nozzles of the head unit and the irradiating section in the direction of travel in the sub-scanning direction. making the time until the start of irradiation longer than the time until the liquid applied onto the recording medium by the nozzle on the leading end side in the traveling direction is started to be irradiated with light ;
The head unit has a plurality of heads each provided with a plurality of nozzles for ejecting the liquid in the sub-scanning direction,
the tip-side nozzles are part of the nozzles on the tip side of the tip-side head in the traveling direction;
The nozzles on the trailing end side are the nozzles on the entire head on the trailing end side in the traveling direction and the nozzles on the remaining portion on the trailing end side of the head on the leading end side.
A liquid ejection device is provided.

According to one aspect, it is possible to form an overcoat layer with a uniform gloss without lowering productivity in a liquid ejecting apparatus.

1 is an overall perspective view of an inkjet recording apparatus according to a first embodiment of the present invention; FIG. FIG. 2 is a cross-sectional view of the carriage of FIG. 1; FIG. 3 is a rear view showing the arrangement of a head unit and an irradiation unit in the carriage of FIG. 2; FIG. 2 is an overall view of an inkjet recording apparatus according to a second embodiment of the invention; 1 is a block diagram of a hardware configuration in an example of an image forming apparatus according to the present invention; FIG. FIG. 3 is a functional block diagram of a control section related to image processing of the image forming apparatus according to the present invention; 4A and 4B are views for explaining the position of the head and the irradiation state of the irradiation unit in the carriage of FIG. 3; FIG. FIG. 4 is a schematic diagram for explaining the position of the scanning area of the head unit with respect to the print medium in the first embodiment; 9A and 9B are schematic diagrams for explaining the state of dots in each layer for each scan on the recording medium, corresponding to the position of the scanning area on the recording medium in FIG. 8, in the first embodiment; Explanatory drawing of several types of discharge patterns. 4 is an enlarged view of an irradiation state of an irradiation unit in the carriage of FIG. 3; FIG. 4 is a control flow of ejection/irradiation adjustment according to the first embodiment;

EMBODIMENT OF THE INVENTION Hereinafter, the form for implementing this invention is demonstrated with reference to drawings. In each drawing below, the same components are denoted by the same reference numerals, and redundant description may be omitted.

<First Embodiment>
First, the overall configuration of a plurality of embodiments of an image forming apparatus according to the present invention will be described.

FIG. 1 is a perspective view showing the overall configuration of an inkjet recording apparatus as an image forming apparatus according to the first embodiment of the invention.

This inkjet recording apparatus 10 includes a carriage 200 and a stage 11 on which a recording medium is placed. The carriage 200 is provided with a head unit 300, which is an inkjet type image forming unit having a plurality of liquid ejection heads provided with a plurality of nozzles, and ejects liquid from the nozzles of the recording head (recording head). to form an image. The nozzle is provided on the surface facing the stage 11 . In addition, in this embodiment, the liquid is an ink having ultraviolet curing properties as an example.

An irradiation unit 400, which is a light source for irradiating ultraviolet rays, is provided on the surface of the carriage 200 facing the stage 11. As shown in FIG. The irradiation unit 400 (an example of an irradiation section) irradiates light having a wavelength that cures the liquid ejected from the nozzle.

A guide rod 19 spans the left and right side plates 18a and 18b, and the guide rod 19 holds the carriage 200 so as to be movable in the X direction (main scanning direction).

The carriage 200, the guide rods 19, and the side plates 18a and 18b are integrally movable in the Y direction (sub-scanning direction) along the guide rails 29 provided below the stage 11. FIG. Further, the carriage 200 is held movably in the Z direction (vertical direction).

Note that in the configuration of FIG. 1, the stage 11 on which the recording medium is placed is fixed. In the ink jet recording apparatus as shown in FIG. 1, a main scanning operation in which ink is ejected from nozzles onto a recording medium while moving the recording head in the main scanning direction and a sub-scanning operation in which the recording head is moved in the sub-scanning direction are alternately performed. to form an image.

Therefore, in this embodiment, the carriage 200 and the guide rod 19 are moving parts in the main scanning direction (X direction, second direction), and the carriage 200 and the guide rails 29 are moving parts in the sub scanning direction (Y direction, first direction). ).

Next, details of the carriage (main scanning unit) 100 will be described with reference to FIGS. 2 and 3. FIG. A detailed cross-sectional view of the carriage 200 is shown in FIG. 2, and a rear view thereof is shown in FIG. A central head unit 300 provided on the carriage 200 ejects ink. The head unit 300 includes heads (colored heads) 301CM and 301YK that eject CMYK color inks, respectively.

Each head 301 has four nozzle row groups each having a plurality of nozzle holes for ejecting ink in the sub-scanning direction. The YK head 301 is filled with Y and K inks in two columns each. In addition, there is also provided 301S that ejects S ink, which is a special color ink that is a specific color (spot color) such as a specific color that is frequently used or a special color that cannot be created by mixing such as mixing YMCK.

The head unit 300 also includes 301CL1 and 301CL2 that eject clear ink (transparent ink) that forms a gloss coat layer. Note that, in this configuration, the upper right head in the head unit does not eject clear ink, but ejects, for example, a primer (Pr) as a base or a second special color. Each color head has three rows of heads in the sub-scanning direction, and two rows of heads eject clear ink.

Each head 301 is an example of a liquid ejection head that ejects ink when a drive signal is applied to the piezo, which causes the piezo to contract and pressure to change due to the contraction.

In order to maintain and recover the performance of the head 301, the carriage 200 moves to the maintenance unit 500 shown in FIG. 1, and the head is maintained. Although not shown, the carriage 200 is equipped with a pressure mechanism. A pressure mechanism ejects an arbitrary amount of ink from the head. Since ink may remain on the nozzle surface of the head 301 when discharged, the wiper 501 rises and moves in the sub-scanning direction to wipe off the ink adhered to the surface of the head 301 . do.
The carriage 200 is equipped with a height sensor 41 . A height sensor 41 measures the height of the recording medium 101 . Based on the measured value, the carriage 200 descends until the head-to-head gap between the head 301 and the recording medium 101 is 1 mm or an arbitrary set value.

In image formation, when the carriage 200 reciprocates (passes) over the recording medium 101 in the main scanning direction (X direction), ink is ejected from the head 301 of the head unit 300 to form an image. During the reciprocating motion of the carriage 200 , ink ejected from the head 301 onto the recording medium 101 is cured by UV light (ultraviolet), which is active energy rays emitted from the irradiation unit 400 .

Each time scanning is completed, the carriage 200 moves to a predetermined position in the sub-scanning direction, and an image is formed on the surface of the recording medium 101 .

To obtain a clear gloss coating, instead of irradiating immediately after ink is ejected, after applying clear ink to the required area, the ink is cured at a predetermined timing after the passage of a predetermined time to form a gloss coating layer. do. Adjust and set the time for smoothing the clear ink after the clear ink is applied (hereinafter referred to as leveling time). The setting of the leveling time from the application of clear ink to the irradiation of UV light will be described in detail with reference to FIGS. 7 to 12. FIG.
The coating described here may be, other than gloss coating, direct application of color ink or clear ink to the entire surface of the substrate, or application of clear ink after printing with color ink.

As shown in FIG. 3, the irradiation unit 400 is composed of an assembly of a plurality of LED-UV lamps using LEDs as light sources, and is provided with left and right irradiation units 400L and 400R, respectively. The lamp groups 401L and 401R are divided into irradiation blocks 401L1 to 401L9 and 401R1 to R9 each composed of independent lamps, and each irradiation block can independently control the output of the LED.

The lamp groups 401L and 401R are connected to the lamp moving mechanism 42. As shown in FIG. The lamp moving mechanism 42 is connected to a lamp fixing mechanism 43 fixed to the head unit 300 of the carriage 200 and a guide rail 444 . A lamp fixing pin 45 is connected to the lamp fixing mechanism 43 through the lamp moving mechanism 42 . By turning the lamp fixing pin 45 to release the fixing and pushing/pulling the lamp group 401 , the lamp group 401 can be moved in the sub-scanning direction along the guide rail 44 . When the lamp group 401 is moved to an arbitrary position, it is fixed by the lamp fixing pin 45, and printing can be performed at an arbitrary lamp position.

<Second embodiment>
FIG. 4 is an overall view (rear view) of an inkjet recording apparatus according to a second embodiment of the invention.

In this embodiment, a conveying belt 71, which is conveying means on which the recording medium 101 is placed, is movable. In the inkjet recording apparatus 1 of this embodiment, in the sub-scanning operation, the recording medium 101 is moved in the sub-scanning direction with respect to the carriage 20 having the head unit 30 and the irradiation units 40L and 40R.

In this embodiment, a conveying belt 71 and conveying rollers 72a and 72b for conveying the recording medium 101 are provided, and a suction support plate 72 for maintaining the conveying state is provided. Maintenance units 50a and 50b are provided on both sides of the conveying belt 71 in the scanning direction.

Therefore, in this embodiment, a main scanning operation in which ink is ejected from the nozzles of a plurality of heads 301 onto a print medium while moving the carriage 20 in the main scanning direction, and a sub-scanning operation in which the print medium 101 is moved in the sub-scanning direction. and are alternately repeated to form an image.

Therefore, in this embodiment, the carriage 20 and the guide rod 19 are moving parts in the main scanning direction (X direction, second direction), and the conveying belt 71, the suction support plate 72, and the conveying rollers 72a and 72b are moving parts in the sub-scanning direction. It functions as a moving part in the (Y direction, first direction).

<Hardware configuration example>
FIG. 5 is a block diagram showing an example of the overall hardware configuration of an image forming system including the inkjet recording apparatuses 10 and 1 of the first and second embodiments. In the system shown in FIG. 5, in the image forming system, as shown in FIG. 1 to FIG. 3 or FIG. An example is shown in which a device, PC2, is connected and the PC2 executes image processing. Note that the function related to the image processing executed by the PC 2 may be provided inside the image forming apparatus.

The PC 2 (computer) 2 is equipped with a printer driver. The printer driver converts the image data into print data. The print data converted by the printer driver is sent to the inkjet printing apparatus 10 . The print data includes command data for operating the transport unit 600 and the like, and pixel data relating to images. The pixel data consists of 2-bit data for each pixel, and is expressed in 4 gradations.

As shown in FIG. 7, the image forming apparatus 30 (inkjet recording apparatus 10, 1) of the present embodiment includes a controller unit 3, a detection group 4, a transport unit 600 as a transport unit, a carriage 200, and a head unit. 300, an irradiation unit 400, and a maintenance unit 500.

The controller unit 3 also includes a unit control circuit 31 , a memory 32 , a CPU (Central Processing Unit) 33 and an I/F 34 . The controller unit 3 controls each unit based on data received from the computer PC2 to form an image. The controller unit 3 is also a computer that controls each unit based on detection data from the detection group 4 and others.

The I/F 34 is an interface for connecting the image forming apparatus 30 (10, 1) with an external PC (Personal Computer) 2 . Any form of connection between the image forming apparatus 30 and the PC 2 may be employed, and examples thereof include a form of connection via a network and a form of direct connection between the two with a communication cable.

The detection group 4 includes, for example, various sensors provided in the inkjet recording apparatus 10(1) such as the height sensor 41 shown in FIGS.

The CPU 33 controls the operation of each unit of the inkjet recording apparatus 10 via the unit control circuit 31 using the memory 32 as a work area. Specifically, the CPU 33 controls the operation of each unit based on the recording data received from the PC 2 and the data detected by the detection group 4, and controls the liquid application surface 102 on the recording medium 101 (base material). form an image.

(function block)
Next, functional blocks of the present invention will be described. FIG. 6 is a functional block diagram relating to image processing in the image forming system according to the present invention.

The image processing device 12 includes a main control section 13 . The main control unit 13 is a computer including a CPU and the like, and controls the entire image processing apparatus 12 . The main control unit 13 may be configured by other than a general-purpose CPU, for example, the main control unit 13 may be configured by a circuit or the like.

Further, the image processing device 12 may be implemented by the PC 2 connected to the image forming device 30 as shown in FIG. 6, or may be provided inside the image forming device 30 .

The main control portion 13 includes a data reception portion 12A, a data creation portion 12B, and a data output portion 12C. A part or all of the data receiving unit 12A, the data creating unit 12B, and the data outputting unit 12C may be realized by executing a program on a processing device such as a CPU, that is, by software, or by an IC (Integrated Circuit) or the like, or may be realized using both software and hardware.

The data reception unit 12A receives image data. Image data is information such as the shape and color of an image to be formed. The data receiving unit 12A may acquire image data from an external device or may acquire image data from storage means provided in the image processing apparatus 12 via the communication unit.

The data creation unit 12B performs predetermined data processing such as mask processing on the image data received by the data reception unit 12A. In this embodiment, color ink image data and clear ink image data are created based on image data (for example, JPEG image data) and desired glossiness.

The data output section 12C outputs the image data created by the data creation section 12B to the image forming apparatus 30 .

The image forming apparatus 30 (10,1) includes a recording drive section 26, a print mode reception section 21, an irradiation section 22, drive sections 23 and 24, a recording control section 27, and an irradiation control section 28. .

The recording driving section 26 is a head driving section that drives droplet ejection of the head units 300K to 300W based on image data controlled by the recording control section 27 .

The irradiation unit 22 corresponds to the lamp groups 401R and 401L, which are light sources in the irradiation units 400R and 400L provided in the carriage 200, and each block is one or a plurality of lamps dividing the lamp groups 401R and 401L in the sub-scanning direction. is an irradiation drive unit that drives the ON/OFF of the .

The driving units 23 and 24 drive the moving units. The first driving unit 23 drives the X-direction movement (scanning movement) of the carriage 200 during scanning, and the second driving unit 24 drives the movement of the carriage 200 in the X direction. , drives the movement (sub-scanning movement) of the carriage 200 (first embodiment) or the recording medium 101 (second embodiment) in the sub-scanning direction during sub-scanning.

The recording control unit 27 receives print data from the image processing device 12 . The recording control unit 27 controls the recording driving unit 26 so that droplets corresponding to each pixel are ejected from the head 18 according to the received print data.

The recording control unit 27 also calculates, for example, the time from ink ejection to light irradiation, and calculates the glossiness of the image formed on the recording medium 101 from the ink ejection amount and the time from light irradiation. , calculations and the like for determining the ejection amounts of colored ink and clear ink for uniform glossiness.

The irradiation control unit 28 controls the irradiation unit 22 so as to set the irradiation timing and irradiation time for each block of the irradiation unit according to the instruction of the matte area (matte part) and the gloss area (glossy part).

Specifically, the recording control unit 27 includes a colored ink gradation setting unit 27A, a transparent ink ejection pattern selection unit 27B, a transparent ink gradation setting unit 27C, a print rate adjustment unit 27D, and a droplet size adjustment unit 27E. ing.

The colored ink gradation setting unit 27A sets a gradation mask for each head for image data to be formed in color so that both ends of the colored ink head in the sub-scanning direction become gradually lighter.

The transparent ink ejection pattern selection unit 27B selects which method among the transparent ink gradation setting unit 27C, the print ratio adjustment unit 27D, and the droplet size adjustment unit 27E is used to separately paint the matte area and the gloss area with transparent ink. do. The details of the separate coloring method will be described later with reference to FIG.

The transparent ink ejection pattern selection unit 27B, the transparent ink gradation setting unit 27C, the print rate adjustment unit 27D, and the droplet size adjustment unit 27E function as a liquid ejection amount adjustment unit 270 that adjusts the ejection amount of the transparent ink.

The irradiation control section 28 includes an irradiation region setting section 28A and an irradiation time setting section 28B.

The irradiation area setting unit 28A sets an irradiation target area in the irradiation unit 22 . The irradiation time setting unit 28B sets the irradiation start timing and irradiation time of the lamp in the irradiation unit 22 . Detailed control of the lamp groups (irradiation units) 401L and 401R will be described in detail with reference to FIG.

In this block diagram, an example in which the image forming apparatus has the function of adjusting the ejection of transparent ink and adjusting the irradiation unit has been described. may be provided in the data generation unit 12B.

Furthermore, in another information processing device (for example, a host device) connected to the PC 2, a program is set in advance and stored in a calculation file (for example, a CSV (Comma Separated Value) file or an Excel file) format, and the PC 2 By reading the program in , the clear ink ejection adjustment program may be executed.

<Example of irradiation and ejection pattern adjustment>
Next, adjustment of ejection and irradiation in the first embodiment will be described with reference to FIGS. 7 to 12. FIG. FIG. 7 is a diagram for explaining the position of the head and the irradiation state of the lamp group 401R in the head unit 300 of the carriage 200 of FIG. As shown in FIG. 7, the head unit 300 is provided with two heads 301CL1 and 301CL2 for ejecting UV curable clear ink in the sub-scanning direction.

As shown in FIG. 7, the four colored heads 301C1, M1, Y1, and K1 on the farthest tip side print in color, and clear coating is applied thereon by the clear heads 301CL1 and CL2.

In the same scanning movement operation, if the clear ink is ejected immediately after the colored ink is ejected, the colored ink and the color ink are mixed and the target image cannot be formed. Colored ink and clear ink are not ejected from the head of .

Note that the head on the front end and the head on the rear end, which will be described below, refer to the front end (front) and the rear end of a plurality of heads that eject clear ink in the advancing direction (moving direction) of the carriage in the sub-scanning direction. means (behind).

The irradiation unit 400 is configured by arranging a plurality of lamps each having an irradiation area divided in the sub-scanning direction, and the plurality of lamps can be individually controlled to be turned on and off. The lamp irradiates actinic energy rays that cure the liquid, which cures the ink.

In FIG. 7, the irradiation unit 400 shows a state during the ejection operation. The lamps 401R5-R8 are extinguished, and the lamps 401R1-R4 and 401R9 are lit. That is, the portion corresponding to the clear head 301CL2 on the rear end side is turned off, and at least a part of the portion corresponding to the clear head 301CL1 on the leading end side is turned on.

In this way, a part of the tip side of the tip side head 301CL1 is illuminated by the lighting units (401R3, R4) of the lamp, so that at least part of the ink ejected from the tip side head 301CL1 is Cures quickly to matte (results in matte areas).

Therefore, the head 301CL2 on the rear end side and part of the rear end side of the head 301CL1 on the front end side are located at the non-lighting portions (401R5, R6, R7, R8) of the lamp, and the ink ejected from the head on the rear end side is , the ink is not irradiated immediately after ejection, but is leveled and then irradiated at the lighting portion of the lamp to become gloss (to form a gloss area).

In this example, there are two clear heads for ejecting clear ink, and an area ejected from some nozzles on the tip side of the tip side head is set as a matte area. Although the area ejected from the remaining nozzles on the rear end side of the tip side head is set as the matte area, other settings may be used for assigning the area.

Here, if the entire sub-scanning area of one or more clear heads that eject clear ink is defined as "a plurality of nozzles," then the nozzles that eject clear ink that forms the matte area are referred to as "nozzles on the tip side" in the traveling direction. , the nozzle that ejects the clear ink that forms the gloss area can be considered as the “rear end nozzle”.

In the example of FIG. 7, the "nozzles on the front end side" correspond to a part of the nozzles on the front end side of the head on the front end side, and the "nozzles on the rear end side" correspond to the rear end side head and the rear end side of the front end side head. corresponded to the remaining nozzles of

Further, when the lengths of the head and the lamp in the sub-scanning direction can be made substantially equal, the "nozzles on the leading end side" correspond to the nozzles on the entire head on the leading end side, and the "nozzles on the trailing end side" correspond to the nozzles on the trailing end side. corresponds to the nozzles on the entire head of

Furthermore, it is also possible to set the number of clear heads for ejecting clear ink to three or more, or one. For example, when one clear head is used to set a matte area and a gloss area, the "nozzles on the front end side" correspond to some nozzles on the front end side in the traveling direction of one head, and the "rear end The "nozzles on the side" correspond to the remaining nozzles on the trailing end side in the traveling direction of one head.

<State of ink droplets>
Here, with reference to FIGS. 8 and 9, the ink landing area and the state of the landing droplets by a plurality of scans when the lighting unit is controlled to turn on and off as shown in FIG. 7 will be described.

FIG. 8 is a schematic diagram for explaining the position of the scanning area of the head unit with respect to the recording medium in the first embodiment. 9A and 9B are schematic diagrams for explaining the state of landed droplets on each layer for each scan on the recording medium, corresponding to the position of the scanning area on the recording medium in FIG. 8, in the first embodiment.

8A, 8B, 8C, and 8D, the position of the printing medium 101 is fixed, and the carriage 200 is moved in the sub-scanning direction by the line feed width. , 1st, 2nd, 3rd and 4th scans. FIG.

FIG. 8 illustrates a bi-directional print sequence in which an image is formed on a recording medium by alternately repeating an operation in which the carriage scans in the main scanning direction and an operation in which the carriage moves in the sub-scanning direction. The movement of the carriage in the sub-scanning direction during the reciprocating movement of the carriage in the main scanning direction is also referred to as the line feed width movement movement.

In this example, the line feed width in the sub-scanning direction=the width of the gloss area is shown.

In FIGS. 9(a), 9(b), 9(c) and 9(d), respectively, FIGS. 8(a), 8(b), 8(c) and 8(d) 2 is a schematic diagram showing states of dots (ink droplets) landed by the first, second, third, and fourth scans shown in FIG. 9 corresponds to a diagram viewed from the right side of FIG.

Here, as shown in FIGS. 9A to 9D, during printing, in the irradiation unit 400, the lamps 401R1, R2, R3, R4, R5, and R9 are always ON as shown in FIG. Lamps 401R6, R7 and R8 are always set to OFF.

As shown in FIGS. 8A and 9A, only colored ink droplets are ejected in the first scan. Colored ink droplets are then irradiated by the lamp on the tip side, and the colored ink droplets are cured.

As shown in FIGS. 8B and 9B, in the second scan, colored ink droplets are ejected and clear ink droplets are ejected from the clear head on the leading end side. Then, the colored ink droplets and the clear ink are irradiated by the lamp on the tip side, the colored ink droplets are cured, and the clear ink droplets become matte.

Here, in the area where the clear ink is ejected by the leading end head 301CL1, by irradiating the light in the same scanning as the ink application, the time from the ink droplet landing on the recording medium 101 (base material) to the UV irradiation is short. As a result, the droplets remain standing and harden with little leveling (unification or smoothing) between the droplets. It can be a matte area.

As shown in FIGS. 8C and 9C, in the third scan, colored ink droplets are ejected, and clear ink droplets are ejected from the clear heads CL1 and CL2 on the leading end side and the trailing end side. Then, the tip-side lamp irradiates the tip-side regions of the colored ink droplets and the clear ink droplets, curing the colored ink droplets and matting the clear ink droplets. The region of the clear ink droplets ejected by the head on the trailing end side is not irradiated with light in this same scanning and is not cured.

As shown in FIGS. 8D and 9D, in the fourth scan, colored ink droplets are ejected, and clear ink droplets are ejected from the clear heads CL1 and CL2 on the leading end side and the trailing end side. Then, the lamp on the tip side irradiates the colored ink droplets and part of the tip side of the clear ink droplets ejected from the head 301CL1 on the tip side with light to harden and form a mat. The clear ink droplets applied from the trailing head are not irradiated with light in this same scan and are not cured. Further, the last ejected clear ink droplet is irradiated with light from the lamp 401R9 on the rear end side.

As shown in FIGS. 9C and 9D, the clear ink droplets deposited on the recording medium by the head 301CL2 on the rear end side are not immediately irradiated with light by the lamp 401, After the passage of time for one scan, light is emitted from the corresponding block.

In the area where the clear ink is applied by the head on the rear end side, the time from the ink droplet landing on the recording medium (substrate) to the UV irradiation becomes longer, so the dot spreads and spreads, and leveling progresses. Dot height becomes lower. When UV light is irradiated in a state in which this leveling has progressed, the surface of the image becomes a gloss area that imparts a glossiness and a glossiness.

In addition, in FIG. 9D, the clear ink droplets of the third layer enter the gaps between the ink droplets of the uneven second layer matte region.

Also, for the clear ink droplets ejected from the head on the rear end side, which were not irradiated with light in the third scan in FIG. 9C, the UV Light is applied. Therefore, since the ink droplets in that area are left for at least one scan as the time before lamp irradiation, the droplets of the second layer are deposited in the concave portions of the uneven first layer cured in a standing state. By entering, the surface is further smoothed (leveled).

In the example of FIG. 9, during the printing operation, the clear ink is not ejected in the first scan on the rear end side where the printing operation starts, so the formation of the matte layer with the clear ink is realized in the second and subsequent scans. Also, at the start of the printing operation, the liquid is ejected from the trailing head for the first time in the third scan, and the area becomes a gloss area after the next scan (fourth scan) and thereafter.

The head unit has y heads in the sub-scanning direction, at least two of which are clear heads. Therefore, the (y−1)th clear ink head from the front end side is the front end side clear ink head, and the yth end side clear ink head is the rear end side clear ink head. Therefore, formation of a matte layer with clear ink ejected from the leading end head is realized after (y−1) times of scanning, and formation of a gloss layer with clear ink ejected from the trailing head is performed after (y+1) scans. ) is realized after the second scan.

In addition, as shown in FIGS. 9A to 9D, as the carriage moves in the advancing direction due to line feed, ink droplets are ejected toward the leading end side (right side in FIG. 9) in the advancing direction. As shown in FIG. 9D, the gloss area is formed on the rear end side of the ink droplet formation area, and is formed on the rearmost side (left side) of the area where the ink droplets have landed on the medium. Therefore, ink droplets are not superimposed on the gloss layer.

In this way, a plurality of heads for ejecting clear ink are provided in the sub-scanning direction, and the irradiation start timing is made different between the head on the leading end side and the trailing end side in the advancing direction of the carriage in the sub-scanning direction. After the scanning of , the gloss layer is formed on the mat layer for each line feed width, so the topmost layer on the trailing end side that is completed is always the gloss layer. Since the matte layer is always formed, the matte layer reduces the unevenness even in areas where the color layer is thin and has severe unevenness, so that the gloss layer can be cleanly wetted and spread easily. Therefore, an overcoat layer with uniform glossiness can be formed without creating special ejection data.

Note that FIG. 9 illustrates an example in which a gloss layer is formed by irradiating the ejection region (scanning region) of the trailing head in the previous scan with light in the next scan after the scan in which the clear ink was ejected. However, the gloss layer may be formed by irradiating light in a scan after the next scan in which the clear ink is ejected.

In that case, the irradiation area that protrudes to the rear end side from the area where the liquid is ejected by the ejection head is further moved to the rear end side, or the line feed amount is decreased to increase the number of scans. As a result, the clear ink ejection area of the trailing head is irradiated with light at least after the second scan, so the time until irradiation becomes longer, and the leveling of the gloss becomes more advanced.

Using the mechanism of FIG. 9, the head on the trailing end side in the sub-scanning direction is irradiated with light after one or a plurality of scans after ink ejection to make the surface glossy. Returning to FIG. 7, since the ink ejected from the nozzles corresponding to the extinguished portions of the lamps 401R6 to R8 is not cured immediately, the ink is leveled (smoothed) and then irradiated by the lamp 401R9 to complete the coating film.

In this way, in the present invention, by adjusting the illumination start timing (leveling time), the front end side is set to the matte region and the rear end side is set to the gloss region (overcoat layer). The need for additional ejection operations is eliminated, and the matte and gloss overcoat layers can be formed in a series of operations.

Furthermore, it is more preferable to adjust the adhesion amount of clear ink in the matte area and the gloss area in addition to adjusting the irradiation start timing.

As a premise, in the color image formed by the colored head that is ejected before the clear ink, banding is easily visible due to line feed errors. making it difficult.

When clear ink is ejected, different masks are used for the matte area and the gloss area. A gradation mask is used for the matte area, and a uniform mask is used for the gloss area.

More specifically, in the front head 301CL1 of the clear head, it is preferable to set the adjusted ejection pattern so that the application amount of the liquid at both ends in the sub-scanning direction is smaller than that at the center. Even in the matte area formed by the clear head, banding tends to be conspicuous due to line feed errors and the like, as in the case of color, so the print rate at the edges is low, as in the case of color.

On the other hand, the head 301CL2 on the rear end side of the clear head adjusts the discharge amount of the clear ink so as to discharge the liquid uniformly. Even in the gloss area, if ink droplets are ejected with a large dot interval as in gradation, it is difficult for ink droplets to coalesce and spread is poor. Therefore, gradation is not used. In addition, in the gloss area, the ink droplets spread and become smooth, so there is no banding due to feeding or the like, so there is no need for gradation.

More specifically, in FIG. 7, the colored heads 301C1, M1, Y1, and K1 and the clear head CL1, which is the tip side head in the clear ink ejection area, have a gradation-like application amount with a low application amount (printing ratio) at the ends. The clear head CL2 has a substantially uniform print rate.

Of R3 to R5 of the lamp 401 corresponding to the ejection area of the nozzles of the clear head CL1, which is the head on the tip side, R3 and R4 are lit and R5 is extinguished. The inks ejected from the nozzles corresponding to the portions R3 and R4 are irradiated immediately after being deposited, and therefore have a matte tone. In the matte area formed by the clear head CL1, similarly to the color area, banding becomes more noticeable due to line feed errors and the like, so the printing rate of the edges is low as in the case of the color area.

On the other hand, R5, 6, 7, and 8 of the lamp 401 corresponding to the ejection area of the nozzles of the clear head CL2, which is the head on the rear end side, are extinguished. Therefore, the ink ejected from the clear head CL2 is not cured immediately after adhering to the color coating film. Ink that is not cured sticks to each other and spreads and becomes smooth. In particular, where the amount of color ink adhered is small, unevenness becomes conspicuous due to the base material and the color ink, making it difficult for the ink of the ink coating of the clear head CL2 to wet and spread cleanly.

Further, since the mat formed by the clear head CL1 enters the irregularities and reduces the irregularities, the ink coating of the clear head CL2 on the upper layer spreads neatly. After that, it is cured by R9 of the lamp 401 to form a clean coating film. At that time, if the print rate of the clear head CL2 is low, it may become difficult for the droplets to merge with the adjacent droplets, making it difficult for the droplets to spread cleanly. It is preferable to make it easier to coalesce with the droplets.

Note that the adjusted ejection pattern applied to the head on the tip side is not limited to gradation, and other examples (thinning, droplet reduction) of reducing the application amount at both ends will be described with reference to FIG. 10 .

Further, when the total ink amount of the clear head CL2 on the trailing end side is larger than the ink amount of the clear head CL1 on the leading end side, smoothing is performed neatly. For example, the printing rate of clear ink for the head on the leading end side is set to 30% for the entire head, and the printing rate for the head on the trailing side is set to 90% for the entire head.

Therefore, in order to adjust the amount of ink, at least the adjustment pattern such as the gradation pattern on both ends is applied to the upper head in the clear head CL1 on the leading end side, which has the smaller amount of ink.

<Discharge pattern>
Next, the adjusted ejection pattern of the clear ink will be described with reference to FIG.

In FIG. 10, (a) is a bottom view of an example of an ejection head, and (b) to (e) are diagrams for explaining various kinds of ejection patterns. 10(b) to 10(e) show an example in which the length of each ejection pattern in the sub-scanning direction corresponds to the length of the nozzle row N of one head shown in FIG. 10(a). there is

As shown in FIG. 8, in order to separately paint the matte area and the gloss area by adjusting the ejection, in the matte area, as shown in FIGS. A variable adjustment discharge mask (discharge adjustment pattern mask) is used, and a uniform mask (uniform pattern mask) shown in FIG. 10E is used in the gloss area.

FIG. 10B shows a gradation mask as an example of the ejection adjustment mask. Gradation is a process in which the center of the image data of one head is darker overall, and the number of dots (printing ratio) ejected from the nozzles decreases toward the edges.

Here, the print rate indicates the ratio of pixels that are output by performing an ink ejection operation according to the value of the pixel data among the pixels related to the pixel data corresponding to the nozzles in each head of the head unit. value.

For example, when X droplets (X is an integer) can be ejected from a specific nozzle when the carriage 200 is scanned at a predetermined speed, and the nozzle executes the ejection operation at all positions, 100 %become. However, since there are cases where the ejection operation is not performed at all positions, the print rate (%) is the number of times the output data (driving data) for actually performing the ejection operation is applied, using X droplets as the parameter. do.

FIG. 10C shows an edge thinning mask as an example of an ejection adjustment mask. In this example, the print rate gradually decreases at a predetermined width E on both end sides in the sub-scanning direction of the head. That is, the number of dots is reduced while the size of the dots remains the same, resulting in a decrease in the amount of ink adhered per area.

Here, the gradation mask and the edge thinning mask have in common that dots are thinned out stepwise toward the edge in both end regions. However, in the gradation mask, the dots are gradually darkened in the center to compensate for thinning at both ends, while in the edge thinning mask, dots are adjusted for the center where thinning is not performed. The difference is that no processing is performed.

FIG. 10D shows a droplet size adjustment mask as an example of the ejection adjustment mask. In this example, the droplet size gradually decreases within a predetermined width E on both end sides of the head in the sub-scanning direction. That is, the size of one dot to which the ejected droplet adheres is reduced (smaller droplet) without changing the number of dots, so that the amount of ink adhered per area is reduced.

Here, when the droplet size, which is the ejection amount per droplet ejected from the nozzle, is adjusted, for example, one of the preset stepwise ejection amounts for large droplets, medium droplets, and small droplets is A drop size may be selected, or the drop size may be adjusted from the specified size by fine-tuning to the predetermined drop size.

<Positional movement of irradiation unit>
FIG. 11 is an enlarged view for explaining the positions of the lamps in the irradiation unit 400. FIG.

As a premise, the finer the element R of the lamp 401, the more targeted the control, but if it is made too small, the cost increases. Therefore, when using a commercially available lamp having a predetermined width, it is difficult to make the irradiation range exactly the same as the length of the head.

Therefore, if an attempt is made to make the entire area of the clear head CL2 on the rear end side into a gloss area, the matte portion of the clear head CL1 on the front end side has an approximate length.

However, since one matte area is used to form one head image, if the matte area has an incomplete length, the matte will be incomplete, resulting in banding.

Therefore, it is preferable that the range in which the clear head CL1 on the leading end side becomes matte is extremely short such as 1/4 or less, or extremely long such as 3/4 or more. If the matte area is extremely short, it will be a thin matte area and will not be noticeable. If the matte area is extremely long, the print rate of the non-matte area will be very low, the matte area will be almost complete, and the banding will not be visible. This is because it becomes difficult to stand out.

If there is a large amount of printing in the portions where the lamps 401R4 and R5 are lit and not lit, the matte area may expand more than expected due to the influence of leaked light, resulting in banding. It is preferable to set the border at a place with a low print rate so as not to be easily affected.

That is, the boundary between lighting and extinguishing of the plurality of lamps is defined as a range of a predetermined width E (see FIG. 10) at both ends in the sub-scanning direction of the clear head CL1 on the leading end side, which has a thinner print rate than the other portions. Set so that it is within

In FIGS. 7 and 11, one head on the rear end side for gloss and one head on the front end side for matte are set. By including at least the line feed width, the gloss area can be set to be a part of one trailing head, a range slightly longer than one trailing head, or a plurality of trailing heads. In this case, in one head, nozzles may be divided into blocks for a gloss area and a matte area.

For example, if the line feed width changes and the boundary setting of the head between the gloss area and the matte area changes, the position of the boundary between lighting and turning off must also change, but the switching position of the lamp is , the range of the matte area may not be 1/4 or less, or 3/4 or more.

In that case, in addition to ON/OFF switching control of the lamp, by adjusting the position of the region L of the irradiation unit 400 with respect to the region H of the nozzle row in the head unit 300 of the carriage 200, the switching position can be switched between turning on and off. may be adjusted to any desired position.

For example, when moving the irradiation unit 400R, the lamp fixing pin 45 is turned to release the fixation, and the lamp group 401 is pushed and pulled, thereby moving the lamp group 401 in the sub-scanning direction along the guide rail 44. It becomes possible. After the lamp group 401 has moved to an arbitrary position, it is fixed with the lamp fixing pin 45 to complete the movement.

Such movement of the lamp groups 401L and 401R of the irradiation unit 400 is manually performed after determining the line feed width and before printing. In addition, the configuration may be such that the illumination unit is automatically moved by control within the apparatus.

In one scanning movement, as shown in FIG. 9(d), in order to form a gloss area with a time lag with respect to the matte area, the areas that can be irradiated by the lamp groups 401L and 401R are recorded by a plurality of heads. It is preferable to set the position so that it is longer than the area where the clear ink is ejected onto the medium by at least the width of the line feed, on the trailing end side in the sub-scanning direction.

For example, if the gloss area is formed only by the rearmost ramp 401R9, the line feed width is set to B or less. If the line feed width is longer (wider) than B, the two ramps 401R8 and 401R9 on the trailing end side may be set as ramps forming the gloss area.

Further, in FIGS. 8 and 9, an example in which head width=line feed width and single scanning is performed so that the area of the head unit in the sub-scanning direction is provided by three scans has been described. The matte/gloss allocation setting can also be applied to a multi-pass print sequence.

If the print sequence is multipass, line feed is performed with a line feed width shorter than that of the head in the sub-scanning direction. For example, in the sub-scanning direction, when forming an image in the sub-scanning direction by scanning (scanning movement) 24 times with respect to the head unit, the area where colored ink is ejected is 1/3 of the head unit. The number of scans per area is eight (the number of line feeds is seven). In the example of 4-pass 1/2 interlacing, in which the number of printing divisions (passes) in the main scanning direction X is four and the number of printing divisions (interlace) in the sub-scanning direction Y is two, the number of scans (scanning number) is 8 times (n=8).

In this case, as shown in FIG. 9(b), the head on the leading end side starts ejecting clear ink only after the 9th scan (n+1), and as shown in FIG. Clear ink is started to be ejected from the head from the 17th (2n+1) scan onwards.

Further, as shown in FIG. 9D, irradiation of the area where the clear ink is ejected from the head on the rear end side is started from the 25th (3n+1) scan onwards.

<Discharge adjustment/irradiation adjustment flow>
Next, ejection adjustment/irradiation adjustment according to the first embodiment will be described with reference to FIG. FIG. 12 is a control flow of ejection/irradiation adjustment according to the first embodiment.

In S1, the print sequence and line feed width are set.

In S2, the widths of the matte area and the gloss area are set. Note that the width of the gloss area is set to be the same as or larger than the line feed width in S1 in the case of multi-pass. Alternatively, in the case of a single scan, the width of the gloss area is set to be the same as or larger than the area excluding the overlap area between scans.

In S3, the positions of the lamp groups 401L and 401R of the irradiation section are moved. Note that this step may be omitted if this step is unnecessary, such as when the line feed width is the same as in the previous scan.

In S3, the lamp groups 401L and 401R move in a single scanning movement so that the areas that can be irradiated by the lamp groups 401L and 401R follow in the sub-scanning direction from the areas where the clear ink is ejected from the plurality of heads onto the recording medium. The position is set so that it is at least as long as the width of the line feed on the end side.

In S4, an adjusted ejection pattern is selected in the tip side head. 10B to 10D, any one of gradation/thinning/droplet size adjustment is selected in which the amount of liquid applied at both ends in the sub-scanning direction is less than that at the center. Select and set for the distal head.

In S5, the lamp is turned on/off in accordance with the set control information in the irradiation unit along the length of the matte area/gloss area set in S2 in the sub-scanning direction. In the example of FIG. 7, lamps 401R1, R2, R3, R4, and R9 are lit, and lamps R5, R6, R7, and R8 are extinguished.

In S6, while moving in the main scanning direction, a gradation mask is applied to each head by a colored head that ejects color ink on the front end side of the region where the clear ink is ejected.

In S7, while moving in the main scanning direction, a clear head that ejects clear ink masks the set adjustment ejection pattern on the front end side, and ejects in a uniform pattern on the rear end side.

Here, for example, assuming that there are m rows of heads that eject colored ink in the sub-scanning direction, two rows of heads that eject clear ink, and the number of scans per head region is n, the print medium 101 is The clear ink is not ejected until the (m×n)-th scan (in FIG. 9A, the first scan because of m=1 and n=1) when scanning starts from the rearmost side.

Also, until the {(m+1)×n}th scan (the second scan in FIG. 9B) from the rear end side of the recording medium 101, clear ink is ejected only from the head on the front end side. Do not perform on the side head.

In S8, at the end of movement in the main scanning direction, a predetermined block of the lamp group 401 of the irradiation unit 400 irradiates light onto the region of the liquid applied onto the recording medium by the tip side head. In this way, the area of the liquid applied on the recording medium by the tip-side head is irradiated with light immediately after ejection, so that the area is cured and matted.

Note that S6 to S8 are executed within one scan in the main scanning direction (see FIG. 9C). Then, after the {(m+1)×n+1}th scan (the third scan in the example of FIG. 9C), irradiation is started on the area where the clear ink is ejected from the head on the rear end side, The formation of the gloss area starts after the {(m+2)n+1}th scan (the fourth scan in the example of FIG. 9D). In other words, the gloss area is irradiated from the n-th scan after the scan in which the clear ink is ejected from the head on the rear end side.

In S9, the carriage 200 is moved in the sub-scanning direction by the line feed width.

The above operation is repeated until printing stops in S10.

It should be noted that the colored heads 301K1, Y1, M1, C1, S1, etc., provided on the most distal side with respect to the position facing the end of the ejection area on the recording medium 101 defined based on the image data, are clear-colored. head 301CL1, CL2. Therefore, when the colored heads 301K1, Y1, M1, C1, and S1 reach the position facing the end of the ejection area on the recording medium 101, ejection is stopped in order from the nozzles located on the tip side. The clear heads 301CL1 and CL2 continue to eject clear ink so as to cover all areas where the colored ink droplets land on the recording medium 101 by the colored heads 301K1, Y1, M1, C1, and S1 even after the colored heads have finished ejecting. continue. Further, the clear ink droplets ejected from the trailing head 301CL2 are irradiated with light with a time difference so that the top layer of all ejection regions becomes a gloss region.

When the printing stops, the lamps 401R1, R2, R3, R4, and R9, which are the blocks that had been lit, are turned off in the lighting section.

With such control, the color and clear inks ejected by the heads on the front end side are smoothed out to form a matte area, and the inks ejected by the head on the rear end side are in a uniform leveling state, resulting in a beautiful gloss. A region can be obtained in a series of operations (high speed).

Therefore, since the matte layer and the overcoat layer are formed in one job without generating data for the matte layer, the productivity of the overcoat layer with even glossiness can be improved. That is, in the embodiment of the present invention, it is possible to form an overcoat layer with uniform glossiness while improving productivity.

In this flow, for simplification of explanation, the head on the front end side is set to be matte, and the head on the rear end side is set to be gloss. For example, as shown in FIG. , at least a portion of the front end side of the head on the front end side may be set to be matte, and the rear end side head and the rest of the rear end side of the head on the front end side may be set to be gloss.

In that case, in S8, a predetermined block of the lamp group 401 of the irradiation unit 400 irradiates light onto the region of the liquid applied onto the recording medium by the tip side head at the end of movement in the main scanning direction. In this way, at least a part of the tip side of the tip side head irradiates light to the area of the liquid applied on the recording medium immediately after the ejection, so that the liquid hardens and becomes matte.

Further, in S8, the area of the liquid applied onto the recording medium 101 by the rear end side head and the remaining portion of the rear end side of the front end side head is not irradiated in S8 immediately after S7, and after the line feed ( In S9), the area is left for a plurality of scans (n times) while leveling, and then illuminated by the lamp lighting portion R9 to become a gloss area.

In the above example, an example of landing two types of ink, colored ink droplets and clear ink droplets, has been described. , the above control of the overcoat layer can be implemented. In the case of the print mode that configures the primer layer, the control above the colored ink droplets is the same scanning for the clear ink droplets and the colored ink droplets of the head on the tip side, as in FIG. 9 above. Then, the clear ink droplets on the trailing head are irradiated with light in subsequent scans, thereby forming a desired matte area and gloss area.

In the flow of FIG. 12, the tip side head is described as the "tip side nozzle" and the rear side head is described as the "rear side nozzle". The "rear end side nozzles" may be "the rear end side head + the remaining nozzles in the front end side head".

Also, when setting the matte area and the gloss area using one clear head, the "nozzles on the front end side" are some of the nozzles on the front end side of one head, and the "nozzles on the rear end side". are the remaining nozzles on the rear end side of one head. In this case, in the clear head, it is preferable to separately paint the adjustment ejection pattern on the front end side and the rear end side, but a uniform ejection pattern may be set.

<Scanning position in the second embodiment>
7 to 12, in the sub-scanning operation in the first embodiment, the carriage 200 including the head unit 300 and the irradiation unit 400 is moved relative to the print medium. Although an example of control has been described, the above control can also be applied to the second embodiment shown in FIG.

In this embodiment, in illumination adjustment and ejection adjustment control in the sub-scanning direction, a matte area is formed in the head on the upstream side in the conveying direction of the print medium, and a gloss area is formed in the head on the downstream side in the conveying direction of the print medium 101. .

Therefore, in this embodiment, the "leading head" in S4, S7, and S8 in the flow of FIG. The head on the downstream side in the recording medium conveying direction". Further, instead of moving the carriage in the sub-scanning direction by the line feed in S9, the recording medium is moved in the sub-scanning direction by the line feed by the conveying belt. Other than that, it is almost the same as the first embodiment.

In the present embodiment as well, a plurality of heads for ejecting clear ink are provided in the recording medium transport direction, and the irradiation start timing is different between the head on the upstream side and the head on the downstream side in the transport direction. Thereafter, since the gloss layer is formed on the mat layer for each line feed width, the uppermost layer on the most downstream side is always the gloss layer.

With such control, even in the present embodiment, unevenness due to color is smoothed out in the upstream matte area of the clear area ejection area, and the downstream area is in a uniform leveling state, and a beautiful gloss can be obtained in a series of operations (high speed). . Therefore, since the matte layer and the overcoat layer are formed in one job without generating data for the matte layer, the productivity of the overcoat layer with even glossiness can be improved. That is, an overcoat layer having a uniform glossiness is formed while improving productivity.

In the above description, the head on the upstream side is referred to as the "nozzle on the upstream side" and the head on the downstream side is referred to as the "nozzle on the downstream side". Some nozzles upstream of the side head, the "downstream nozzles", may be the downstream head plus the rest of the nozzles downstream of the upstream head.

Further, when setting the matte area and the gloss area using one clear head, the "upstream nozzles" are some nozzles on the upstream side in one head, and the "downstream nozzles" are , the rest of the nozzles downstream in one head. In this case, in the clear head, it is preferable to separately paint the adjusted ejection pattern on the upstream side and the downstream side, but a uniform ejection pattern may be set for the head.

Although the preferred embodiments of the present invention have been described in detail above, the present invention is not limited to such specific embodiments, and within the scope of the embodiments of the present invention described in the claims, Various modifications and changes are possible.

For example, in the above embodiments, an inkjet recording apparatus equipped with a recording head according to the present invention has been described. can be applied.

In the present application, a "liquid ejection apparatus" is an apparatus that includes a liquid ejection head or a liquid ejection unit, drives the liquid ejection head, and ejects liquid.

The above-mentioned "substance to which a liquid can adhere" means a substance to which a liquid can adhere at least temporarily, such as a substance to which a liquid adheres and adheres, a substance which adheres and permeates, and the like. Specific examples include media such as recording media such as paper, recording paper, recording paper, film, and cloth, electronic components such as electronic substrates and piezoelectric elements, powder layers (powder layers), organ models, and test cells. Yes, and unless otherwise specified, includes anything that has liquid on it.

The material of the above-mentioned "thing to which a liquid can adhere" may be paper, thread, fiber, fabric, leather, metal, plastic, glass, wood, ceramics, etc., as long as the liquid can adhere even temporarily.

Also, the "liquid ejection head" is not limited to the pressure generating means to be used. For example, a piezoelectric actuator (which may use a laminated piezoelectric element), a thermal actuator using an electrothermal conversion element such as a heating resistor, or an electrostatic actuator consisting of a diaphragm and a counter electrode can be used.

Further, the terms used in the present application, such as image formation, recording, printing, printing, printing, modeling, etc., are synonymous.

10, 1, 30 Inkjet recording device (image forming device, liquid ejection device)
2 PC (computer)
3 Controller unit (computer)
19 guide rod (moving part)
22 irradiation unit (lamp group)
27 recording control unit 270 liquid discharge amount adjustment unit 28 irradiation control unit 200 carriage (main scanning unit)
101 recording medium (substrate)
20,200 carriage (main scanning unit)
30, 300 head unit 301 head 301CL1, 301CL2 clear head 301CL1 tip side head (upstream head, tip side nozzle, upstream nozzle)
301CL2 rear end head (downstream head, rear end nozzle, downstream nozzle)
40 (40L, 40R), 400 (400L, 400R) Irradiation units 401L, 401R Lamp group (irradiation unit)
401L1~L9, 401R1~R9 lamp (irradiation block, block)
29 guide rail (moving part)
600 transport unit 71 transport belt (moving unit)
72a, 72b transport rollers (moving part)

JP 2015-214133 A

Claims (13)

a head unit in which a plurality of nozzles for ejecting an active energy ray-curable liquid onto a recording medium are provided as a nozzle row in the sub-scanning direction;
an irradiation unit that is connected to the head unit and that irradiates light of an active energy ray that hardens the liquid on the recording medium by irradiating the liquid with light;
scanning movement for moving the head unit and the irradiation section relative to the recording medium in a scanning direction perpendicular to the sub-scanning direction; a moving unit that alternately performs a sub-scanning movement that moves in the scanning direction;
an irradiation control unit that controls lighting and extinguishing by dividing the sub-scanning direction of the irradiation unit;
During at least part of the scanning movement, the head unit and the irradiation unit discharge liquid onto the recording medium and irradiate the recording medium with light;
After the liquid is ejected onto the recording medium from the plurality of nozzles, the liquid applied onto the recording medium is irradiated with light by the rear end nozzles of the head unit and the irradiating section in the direction of travel in the sub-scanning direction. making the time until the start of irradiation longer than the time until the liquid applied onto the recording medium by the nozzle on the leading end side in the traveling direction is started to be irradiated with light ;
The head unit has a plurality of heads each provided with a plurality of nozzles for ejecting the liquid in the sub-scanning direction,
the tip-side nozzles are part of the nozzles on the tip side of the tip-side head in the traveling direction;
The nozzles on the trailing end side are the nozzles on the entire head on the trailing end side in the traveling direction and the nozzles on the remaining portion on the trailing end side of the head on the leading end side.
Liquid ejection device. A liquid ejection amount adjusting unit that adjusts the amount of liquid applied onto the recording medium by the head on the front end side so as to be smaller than the amount of liquid applied on the recording medium by the head on the rear end side. Item 1. The liquid ejecting apparatus according to item 1 . The liquid ejection amount adjusting section causes the head on the leading end side to eject the liquid so that the amount of the liquid applied to both ends in the sub-scanning direction is smaller than that of the central portion, and the head on the trailing end side ejects the liquid uniformly. 3. The liquid ejection device according to claim 2 , which ejects liquid. a head unit in which a plurality of nozzles for ejecting an active energy ray-curable liquid onto a recording medium are provided as a nozzle row in the sub-scanning direction;
an irradiation unit that is connected to the head unit and that irradiates light of an active energy ray that hardens the liquid on the recording medium by irradiating the liquid with light;
scanning movement for moving the head unit and the irradiation section relative to the recording medium in a scanning direction perpendicular to the sub-scanning direction; a moving unit that alternately performs a sub-scanning movement that moves in the scanning direction;
an irradiation control unit that controls lighting and extinguishing by dividing the sub-scanning direction of the irradiation unit;
During at least part of the scanning movement, the head unit and the irradiation unit discharge liquid onto the recording medium and irradiate the recording medium with light;
After the liquid is ejected onto the recording medium from the plurality of nozzles, the liquid applied onto the recording medium is irradiated with light by the rear end nozzles of the head unit and the irradiating section in the direction of travel in the sub-scanning direction. making the time until the start of irradiation longer than the time until the liquid applied onto the recording medium by the nozzle on the leading end side in the traveling direction is started to be irradiated with light ;
The head unit has a plurality of heads each provided with a plurality of nozzles for ejecting the liquid in the sub-scanning direction,
the nozzle on the tip side is a head on the tip side in the traveling direction;
the nozzle on the rear end side is a head on the rear end side in the traveling direction;
a liquid ejection amount adjusting unit that adjusts the amount of liquid applied onto the recording medium by the head on the front end side so as to be smaller than the amount of liquid applied on the recording medium by the head on the rear end side;
prepared,
The liquid ejection amount adjusting section causes the head on the leading end side to eject the liquid so that the amount of the liquid applied to both ends in the sub-scanning direction is smaller than that of the central portion, and the head on the trailing end side ejects the liquid uniformly. squirt liquid
Liquid ejection device. irradiating the liquid applied onto the recording medium by the tip-side nozzles with light within the same scanning movement for ejecting the liquid from the plurality of nozzles onto the recording medium;
Irradiation of light onto the liquid applied onto the recording medium by the nozzles on the rear end side is performed by one or more sub-scanning movements after the scanning movement for ejecting the liquid from the plurality of nozzles onto the recording medium. 5. A liquid ejection device according to any one of claims 1 to 4, performed in a later, separate scanning movement. The area that can be irradiated by the irradiation unit is set longer on the rear end side in the sub-scanning direction than the area in which liquid is ejected from the plurality of nozzles onto the recording medium in one scanning movement,
In the scanning movement, the irradiation area of the irradiation unit at a position corresponding to the nozzle on the front end side in the sub-scanning direction, and the nozzle located on the rear end side in the sub-scanning direction from the nozzle on the rear end side. The liquid ejecting apparatus according to claim 5 , wherein the irradiation area of the irradiation section is lit, and the irradiation area of the irradiation section at a position corresponding to the nozzle on the rear end side in the sub-scanning direction is turned off. 5. The liquid ejection amount adjustment unit adjusts the ejection amount of the liquid in the head on the front end side so as to form a gradation in which the application amount is gradually decreased toward both ends in the sub-scanning direction. 3. The liquid ejecting apparatus according to . 5. The liquid ejection amount adjusting section adjusts the ejection amount of the liquid so that the number of dots to be ejected is reduced by thinning out the predetermined areas of both ends in the sub-scanning direction. 3. The liquid ejecting apparatus according to . 5. The liquid ejection amount adjustment unit adjusts the ejection amount of the liquid so as to reduce the droplet size of dots ejected in predetermined regions of both ends in the sub-scanning direction in the head on the tip end side. 3. The liquid ejecting apparatus according to . In the case of forming an image by multi-pass scanning n times for each head area,
The irradiation of light onto the liquid applied onto the recording medium by the nozzles on the trailing end side is performed within the n-th scanning movement after the scanning movement for ejecting the liquid from the plurality of nozzles onto the recording medium. The liquid ejection device according to any one of claims 1 to 9 . a head unit in which a plurality of nozzles for ejecting an active energy ray-curable liquid onto a recording medium are provided as a nozzle row in the sub-scanning direction;
an irradiation unit that is connected to the head unit and that irradiates light of an active energy ray that hardens the liquid on the recording medium by irradiating the liquid with light;
scanning movement for moving the head unit and the irradiation section relative to the recording medium in a scanning direction perpendicular to the sub-scanning direction; a moving unit that alternately performs a sub-scanning movement that moves in the scanning direction;
an irradiation control unit that controls lighting and extinguishing by dividing the sub-scanning direction of the irradiation unit;
During at least part of the scanning movement, the head unit and the irradiation unit discharge liquid onto the recording medium and irradiate the recording medium with light;
The time from the ejection of the liquid onto the recording medium from the plurality of nozzles to the start of irradiating light onto the liquid applied onto the recording medium by the nozzles on the downstream side in the recording medium transport direction is defined as the transport of the recording medium. longer than the time to start irradiating the liquid applied onto the recording medium by the nozzle on the upstream side of the direction ,
The head unit has a plurality of heads each provided with a plurality of nozzles for ejecting the liquid in the sub-scanning direction,
the nozzles on the upstream side in the direction of conveyance of the recording medium are part of the nozzles on the upstream side of the head on the upstream side in the direction of conveyance of the recording medium;
The nozzles on the downstream side in the recording medium conveying direction are the nozzles on the entire head on the downstream side in the recording medium conveying direction and the remaining nozzles on the downstream side of the head on the upstream side.
Liquid ejection device. An irradiation control method in a liquid ejection device, comprising:
The liquid ejecting apparatus includes a head unit in which a plurality of nozzles for ejecting an active energy ray-curable liquid onto a recording medium are provided as a nozzle row in a sub-scanning direction; an irradiating unit that irradiates light of an active energy ray that cures the liquid on the recording medium by dividing the sub-scanning direction and switching between lighting and extinguishing; and the head unit and the irradiating unit scanning movement for moving the recording medium in a scanning direction orthogonal to the sub-scanning direction; and sub-scanning movement for moving the head unit and the irradiation section relative to the recording medium in the sub-scanning direction. and a moving part that alternately performs
After the liquid is ejected from the plurality of nozzles onto the recording medium, the liquid applied onto the recording medium is irradiated with light by the head unit and the nozzles on the leading end side of the irradiating section in the direction of travel in the sub-scanning direction. a step;
Liquid applied onto the recording medium by the nozzles on the trailing end in the traveling direction after a predetermined time has elapsed after the liquid is ejected from the plurality of nozzles onto the recording medium, at a slower rate than the irradiation of the light on the nozzles on the leading end. and a step of irradiating light on
The head unit has a plurality of heads each provided with a plurality of nozzles for ejecting the liquid in the sub-scanning direction. and the nozzles on the rear end side are the nozzles on the entire head on the rear end side in the traveling direction and the nozzles on the remaining part on the rear end side of the head on the front end side.
Irradiation control method in liquid ejection device. An irradiation control program for a liquid ejection device,
The liquid ejecting apparatus includes a head unit in which a plurality of nozzles for ejecting active energy ray-curable liquid onto a recording medium are provided as a nozzle row in a sub-scanning direction, and the head unit is connected to the head unit. an irradiating unit that irradiates light of an active energy ray that cures the liquid on the recording medium by dividing the sub-scanning direction and switching between lighting and extinguishing; and the head unit and the irradiating unit scanning movement for moving the recording medium in a scanning direction orthogonal to the sub-scanning direction; and sub-scanning movement for moving the head unit and the irradiation section relative to the recording medium in the sub-scanning direction. and a moving part that alternately performs
After the liquid is ejected from the plurality of nozzles onto the recording medium, the liquid applied onto the recording medium is irradiated with light by the head unit and the nozzles on the leading end side of the irradiating section in the direction of travel in the sub-scanning direction. processing;
Liquid applied onto the recording medium by the nozzles on the trailing end in the traveling direction after a predetermined time has elapsed after the liquid is ejected from the plurality of nozzles onto the recording medium, at a slower rate than the irradiation of the light on the nozzles on the leading end. A computer executes a process of irradiating light on the
The head unit has a plurality of heads each provided with a plurality of nozzles for ejecting the liquid in the sub-scanning direction. and the nozzles on the rear end side are the nozzles on the entire head on the rear end side in the traveling direction and the nozzles on the remaining part on the rear end side of the head on the front end side.
Irradiation control program in a liquid ejection device.

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