JP7423219B2 - Inkjet recording device and recording method - Google Patents

Description

The present invention relates to a recording apparatus and a recording method that form images by ejecting ink.

Currently, inkjet recording devices capable of forming metallic color images are known. In this type of inkjet recording apparatus, a metallic color image is formed by applying glitter ink that exhibits metallic luster when applied to a recording medium, and then applying normal color ink on top of the glitter ink.

However, when a metallic color image is formed by ejecting glitter ink, the formed image may not have sufficient gloss. This is because the glitter ink used in inkjet recording devices contains components other than metal particles, such as a resin component to disperse the metal particles and a solvent component to stabilize the ink. ing.

Furthermore, in order to obtain an image with good gloss, it is necessary that the moving distance of free electrons be close to the wavelength of light. Therefore, it has been thought that it is desirable for the metal particles contained in the glitter ink to have a larger shape. This is because when the metal particles are small, gaps may be formed between the metal particles or light may be scattered, which is a factor that reduces the glossiness of the metallic color image.

On the other hand, Patent Document 1 proposes maintaining the glossiness of an image by concentrating dots recorded with metallic ink and suppressing overlapping of metallic ink and color ink.

JP2009-233877A

However, the technique disclosed in Patent Document 1 does not take into consideration that the glossiness may be reduced by the glitter ink itself. For example, when an image with a high dot recording rate (high duty image), such as a solid image, is recorded using glitter ink, the resin and solvent components contained in the glitter ink will be deposited on the top surface of the metal particles. It tends to remain and cannot increase the gloss of the image. Furthermore, when an image with a low recording density is recorded using glitter ink, the metal particles of the glitter ink may not be sufficiently fused to each other, and sufficient gloss may not be obtained.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a recording apparatus and a recording method capable of obtaining images with good gloss using glitter ink.

The present invention provides a recording device having a recording means capable of applying glitter ink to each of a plurality of unit areas set on a recording medium, the recording unit comprising a recording unit capable of applying glitter ink to each of a plurality of unit areas set on a recording medium. The recording control means controls the recording means to change the amount of the glitter ink applied to each of the recording unit areas according to the number of connections, and the recording control means controls the number of connections of the recording unit areas. The amount of the glitter ink applied to the recording unit area when is a predetermined number of connections is greater than or equal to the amount of the glitter ink applied to the recording unit area whose number of connections is greater than the predetermined number of connections. It is characterized by controlling the recording means.

The present invention also provides a recording method for forming a glitter image by applying glitter ink on a recording medium, wherein the number of connected recording unit areas to which the glitter ink is applied is a predetermined number of connections. The amount of the glitter ink applied to the recording unit area at a certain time is set to be equal to or greater than the amount of the glitter ink applied to the recording unit areas whose number of connections is greater than the predetermined number of connections.

According to the present invention, it is possible to obtain an image with good gloss using glitter ink.

FIG. 1 is a perspective view of an inkjet recording apparatus in first to third embodiments. FIG. 2 is a block diagram showing the configuration of a control system of an inkjet recording apparatus. FIG. 2 is a schematic diagram of an ejection port forming substrate mounted on a recording head. FIG. 3 is a schematic diagram showing an ejection port array provided in a recording head. FIG. 3 is a diagram showing an optical system for measuring the glossiness of an image. FIG. 3 is a diagram showing the relationship between the number of connected pixels in which dots of glitter ink are recorded, the amount of overlapping dots, and glossiness in the first embodiment. FIG. 3 is a cross-sectional view showing a state in which a solid image is formed on a recording medium using glitter ink. FIG. 2 is a cross-sectional view showing a state in which glitter ink is applied to one pixel on a recording medium. 3 is a flowchart showing a method for forming recording data in the first embodiment. FIG. 3 is a diagram showing an index pattern in the first embodiment. FIG. 3 is a diagram illustrating a method of recording an image using multiple passes in the first embodiment. FIG. 3 is a diagram showing a recording process in the first embodiment. FIG. 3 is a diagram showing a mask used in the first embodiment. FIG. 3 is a diagram showing overlapping dots in the first embodiment. FIG. 3 is a diagram showing the relationship between glossiness and implantation amount. FIG. 7 is a diagram showing a method of counting the number of connected dots in the second embodiment. FIG. 7 is a diagram illustrating a method of recording an image using multiple passes in a second embodiment. 12 is a flowchart illustrating a method of forming recording data in a third embodiment. FIG. 7 is a diagram illustrating a method of recording an image using multiple passes in a third embodiment. It is a figure showing the whole structure of an inkjet recording device in a 4th embodiment. FIG. 7 is a diagram illustrating the configuration of a print head provided in a fifth embodiment.

[First embodiment]
Hereinafter, a first embodiment of the present invention will be described in detail with reference to the drawings.

(Configuration of inkjet recording device)
FIG. 1 is a perspective view showing the configuration of an inkjet recording apparatus (hereinafter simply referred to as a recording apparatus) 100 of this embodiment. Note that, in FIG. 1, the recording apparatus 100 is shown with the top cover removed in order to explain the internal mechanism thereof. As shown in FIG. 1, in the recording apparatus 100, a recording medium 104 on which an image is to be recorded is conveyed in a conveyance direction (sub-scanning direction) shown by an arrow F. The recording medium 104 is transported by a transport means operated by a sub-scanning motor 205 (see FIG. 2).

Further, in the recording apparatus 100, a guide shaft 103 is arranged so as to extend in a main scanning direction (S direction) that intersects with a sub-scanning direction F of the recording medium 104. In this embodiment, the main scanning direction (S direction) is determined to be perpendicular to the sub scanning direction (F direction). A carriage 101 carrying a recording head 40 (see FIG. 3) is supported by a guide shaft 103 and is driven by a main scanning motor 204 (see FIG. 2) to move forward and backward in the direction of arrow S (main scanning direction). (scan back and forth). The print head 40 mounted on the carriage 101 ejects ink onto a print medium according to print data while moving in the main scanning direction together with the carriage 101, thereby performing printing on the print medium 104.

When a recording operation command is input from an externally connected host computer, the recording medium 104 is fed by the recording head 40 to a position where recording is possible. Thereafter, the print head 40 performs main scanning while ejecting ink in accordance with the print signal. When one main scan is completed, the recording medium is conveyed by a predetermined amount. By repeating this main scanning and the conveyance operation (sub-scanning) of the recording medium, an image to be recorded on the recording medium 104 is completed. Note that in the recording apparatus 100 of this embodiment, recording is performed on the recording medium 104 by ejecting ink both when the recording head 40 moves along the forward path and when it moves along the backward path. A bidirectional recording method is adopted.

FIG. 2 is a block diagram showing the configuration of the control system of the recording apparatus 100. A host computer 206 is connected to the recording device 100. The host computer 206 transmits information regarding the recording operation of the recording apparatus 100. Information transmitted from the host computer 206 is temporarily stored and accumulated by the reception buffer 207 of the recording device 100.

The recording apparatus 100 is provided with a system controller 201 that controls the entire apparatus. The system controller 201 processes image data received by the reception buffer 207 and controls the operation of each part of the recording apparatus. The system controller 201 includes a CPU that functions as a means for performing processing such as various calculations, acquisition, and control described below, a ROM that stores control programs and masks that will be described later, and a RAM that is used as a work area during CPU processing. etc. are provided.

The recording apparatus 100 is also provided with a main scanning motor 204 for driving the carriage 101 and a sub-scanning motor 205 for driving the recording medium conveyance mechanism. The system controller 201 controls driving of the main scanning motor 204 via the main scanning motor driver 202 and also controls the sub-scanning motor 205 via the sub-scanning motor driver 203.

The recording device 100 includes a frame memory 208 for developing recording data for forming an image. The frame memory 208 is provided corresponding to each of the plurality of types of ink used in the printing apparatus 100. In this embodiment, in addition to color inks of black (K), cyan (C), magenta (M), and yellow (Y), glitter ink (LU ) is used. Therefore, five frame memories 208K, 208C, 208M, and 208Y are provided according to these inks.

Furthermore, the recording device 100 is provided with a buffer 209 for temporarily storing recording data. A buffer 209 is provided for each type of ink. Here, buffers 209K, 209C, 209M, 209Y, and 209LU are provided.

A recording control unit 210 provided in the recording apparatus 100 controls the operation of the recording head 40 via a recording head driver 211 in response to commands from the system controller 201. For example, the recording control unit 210 controls the recording speed of the recording head 40 and the number and position of ejected ink droplets. In this way, in the recording apparatus of this embodiment, the system controller 201 and the recording control section 210 constitute a recording control means that controls recording of images on a recording medium.

In the above configuration, image data supplied from the host computer 206 is transferred to the reception buffer 207 and temporarily stored therein, and expanded into the frame memory 208 for each color by the system controller 201. Next, the developed image data is read out by the system controller 201 and subjected to predetermined image processing, and then developed into the buffer 209 for each color. The recording control unit 210 controls the operation of the recording head 40 based on the image data in each buffer.

(head configuration)
FIG. 3 is a schematic diagram of the configuration of the ejection port forming substrate 30 constituting the recording head 40, viewed from the ejection port side. A plurality of ejection ports 301 for ejecting ink are arranged on the ejection port forming substrate 30 along the sub-scanning direction (S direction). In this embodiment, 1536 ejection ports 301 (ejection ports No. 0 to No. 1535) are arranged at a density of 1200 per inch (1200 dpi) along the sub-scanning direction. One ejection port array is formed by these 1536 ejection ports. Note that in FIG. 3, the ejection ports 30 are arranged in a staggered manner in order to facilitate the arrangement of the ejection ports 301 in the sub-scanning direction.

(head configuration)
FIG. 4 is a plan view showing the recording head 40 viewed from above. The recording head 40 in this embodiment has a configuration in which five ejection port forming substrates 30 shown in FIG. 3 are arranged in parallel. The five ejection port forming substrates 30 respectively correspond to the five colors of ink used in the recording apparatus. That is, the ejection port row 401K corresponds to black ink, the ejection port row 401C corresponds to cyan ink, the ejection port row 401M corresponds to magenta ink, the ejection port row 401Y corresponds to yellow ink, and the ejection port row 401LU corresponds to glitter ink. are doing.

In this embodiment, when printing a color image, some of the ejection ports of each of the ejection port arrays 401K, 401C, 401M, and 401Y that eject color ink are used. Specifically, among the 1536 ejection ports provided in each ejection port row, 768 ejection ports (ejection ports No. 0 to No. 767) located on the downstream side in the sub-scanning direction F are used. .

In addition, when forming a glitter image using glitter ink, the upstream ejection ports (No. 767 to No. 1535) in the sub-scanning direction F in the ejection port array 401LU that ejects the glitter ink (discharge port) is used. Therefore, the glitter ink is applied to the recording medium 104 first, and then the color inks (black, cyan, magenta, yellow) are applied. The amount of ink (ink droplets) ejected from each ejection port is 4 ng.

By ejecting ink droplets from the ejection ports while scanning the recording head 40 configured as described above in the main scanning direction (S direction), a recording density of 2400 dpi in the main scanning direction and 1200 dpi in the sub scanning direction is achieved. A dot is recorded. Therefore, if one dot is recorded in a 1200 dpi square area on the recording medium 104 at 100% duty, printing up to 200% duty is possible. In this embodiment, color ink is printed at a maximum duty of 200%, and glitter ink is printed at a maximum duty of 100%.

In the following description, an area on the recording medium to which only one drop of glitter ink ejected from the ejection opening of the recording head 40 is applied will be referred to as a unit area, and this area will also be referred to as a pixel. Further, among all unit areas (pixels) set on a recording medium, a unit area where dots are recorded by applying ink droplets is called a recording unit area, and is also called a recording pixel.

(Composition of ink)
Here, the composition and purification method of each ink applied to this embodiment will be explained. Hereinafter, "parts" and "%" are based on mass unless otherwise specified.

<Yellow ink>
(1) Preparation of dispersion 10 parts of the pigment shown below, 30 parts of anionic polymer, and 60 parts of pure water are mixed.
- Pigment: [C. I. Pigment Yellow 74 (Product name: Hansa Brilliant Yellow 5GX (manufactured by Clariant)
・Anionic polymer P-1: [styrene/butyl acrylate/acrylic acid copolymer (copolymerization ratio (weight ratio) = 30/40/30), acid value 202, weight average molecular weight 6500, solid content 10% Aqueous solution, neutralizing agent: potassium hydroxide]
Next, the above materials are placed in a batch type vertical sand mill (manufactured by Imex Corporation), filled with 150 parts of zirconia beads having a diameter of 0.3 mm, and subjected to a dispersion treatment for 12 hours while cooling with water. Furthermore, this dispersion liquid is centrifuged to remove coarse particles. As a final preparation, a pigment dispersion I having a solid content of about 12.5% and a weight average particle size of 120 nm is obtained. Using the obtained pigment dispersion, an ink is prepared as follows.

(2) Preparation of ink Mix the following ingredients, stir thoroughly to dissolve and disperse, and then filter under pressure using a microfilter with a pore size of 1.0 μm (manufactured by Fujifilm Corporation) to prepare ink 1. .
- Pigment dispersion obtained above: 40 parts - Glycene: 9 parts - Acetylene glycol ethylene oxide adduct (trade name: Acetylenol EH): 1 part - 1,2-hexanediol: 3 parts - Polyethylene glycol (molecular weight 1000) ): 4 parts/Wednesday: remaining part

<Magenta ink>
(1) Preparation of dispersion Using benzyl acrylate and methacrylic acid as raw materials, an AB type block polymer with an acid value of 300 and a number average molecular weight of 2500 is prepared by a conventional method, neutralized with an aqueous potassium hydroxide solution, and diluted with ion-exchanged water. to prepare a homogeneous 50% by mass aqueous polymer solution. Further, 100 g of this polymer aqueous solution, C.I. I. 100 g of Pigment Red 122 and 300 g of ion-exchanged water are mixed and mechanically stirred for 0.5 hour. This mixture is then processed by passing it five times into an interaction chamber under a liquid pressure of approximately 70 MPa using a microfluidizer. Furthermore, the dispersion liquid obtained above is centrifuged (processing at 12,000 rpm for 20 minutes) to remove non-dispersed substances including coarse particles, resulting in a magenta dispersion liquid. The resulting magenta dispersion had a pigment concentration of 10% by mass and a dispersant concentration of 5% by mass.

(2) Preparation of ink The above magenta dispersion liquid is used to prepare the ink. The following ingredients were added to this to make a predetermined concentration, and after thoroughly mixing and stirring these ingredients, the mixture was filtered under pressure using a microfilter with a pore size of 2.5 μm (manufactured by Fuji Film Corporation) to obtain a pigment concentration of 4 mass. %, and an ink with a dispersant concentration of 2% by mass is prepared.
・Above magenta dispersion: 40 parts ・Glycerin: 10 parts ・Diethylene glycol: 10 parts ・Acetylene glycol EO adduct: 0.5 part ・Water: remainder

<Cyan ink>
(1) Preparation of dispersion Using benzyl acrylate and methacrylic acid as raw materials, an AB type block polymer with an acid value of 250 and a number average molecular weight of 3,000 is prepared by a conventional method, and this is neutralized with an aqueous potassium hydroxide solution and ion-exchanged water is used. to prepare a homogeneous 50% by mass aqueous polymer solution. In addition, 180 g of the above polymer solution, C.I. I. 100 g of Pigment Blue 15:3 and 220 g of ion exchange water are mixed and mechanically stirred for 0.5 hour. The mixture is then processed using a microfluidizer by passing it five times into an interaction chamber under a liquid pressure of about 70 MPa. Furthermore, the dispersion obtained above is centrifuged (12,000 rpm, 20 minutes) to remove non-dispersed materials including coarse particles, thereby obtaining a cyan dispersion. The resulting cyan dispersion had a pigment concentration of 10% by mass and a dispersant concentration of 10% by mass.

(2) Preparation of ink The above cyan dispersion liquid is used to prepare the ink. The following ingredients were added to this to make a predetermined concentration, and after thoroughly mixing and stirring these ingredients, pressure filtration was performed using a microfilter with a pore size of 2.5 μm (manufactured by Fuji Film Corporation) to obtain a pigment concentration of 2% by mass. , an ink with a dispersant concentration of 2% by mass is prepared.
・Above cyan dispersion: 20 parts ・Glycerin: 10 parts ・Diethylene glycol: 10 parts ・Acetylene glycol EO adduct: 0.5 part ・Water: remainder

<Black ink>
(1) Preparation of dispersion 100 g of the polymer solution used in Yellow Ink 1, 100 g of carbon black, and 300 g of ion-exchanged water are mixed and mechanically stirred for 0.5 hour. This mixture is then processed by passing it five times into an interaction chamber under a liquid pressure of about 70 MPa using a microfluidizer. Furthermore, the dispersion obtained above is centrifuged (12,000 rpm, 20 minutes) to remove non-dispersed materials including coarse particles, thereby obtaining a black dispersion. The resulting black dispersion had a pigment concentration of 10% by mass and a dispersant concentration of 6% by mass.

(2) Preparation of ink The above black dispersion liquid is used to prepare the ink. The following components were added to the black dispersion liquid to achieve a predetermined concentration, and after thoroughly mixing and stirring these components, the mixture was filtered under pressure using a microfilter (manufactured by Fujifilm) with a pore size of 2.5 μm to obtain a pigment concentration of 5% by mass. , an ink with a dispersant concentration of 3% by mass is prepared.
・Above black dispersion: 50 parts ・Glycerin: 10 parts ・Triethylene glycol: 10 parts ・Acetylene glycol EO adduct: 0.5 part ・Water: remainder

<Glitter ink>
In this embodiment, commercially available silver nanoparticle ink NBSIJ-MU01 (manufactured by Mitsubishi Paper Mills Co., Ltd.) was used as the glitter ink.

(Measurement method of glossiness)
In this embodiment, the glossiness of the image formed by the glitter ink is improved by optimizing the overlapping amount of dots in each recording pixel according to the number of connected recording pixels for which dots are formed by the glitter ink. It is characterized by increasing A measuring device and a measuring method for measuring the glossiness of an image formed on the recording medium 104 will be described below.

FIG. 5 is a diagram showing a measuring device 500 for measuring the glossiness of an image recorded on a recording medium. The illumination unit 501 illuminates the surface of the recording medium 54. The lighting unit 501 may be a halogen bulb, a xenon lamp, an ultra-high pressure mercury lamp, a deuterium lamp, an LED, or a combination of any of these.

The light detection unit 502 detects specularly reflected light from the surface of the recording medium 503. As a detector included in the photodetecting section 502, a single light receiving surface type photodiode, a phototube, a photomultiplier tube, a multi-element light receiving surface type Si photodiode array, a CCD, etc. can be used. The photodetector 502 also includes a spectroscopic section such as a diffraction grating or a prism. Further, the light detection unit 502 is located at a position tilted at the same angle to the opposite side to the illumination unit 501 with respect to the normal direction of the recording medium 503 (in this embodiment, the incident angle is 45°, so the reflection angle is 45°). position) at the specular reflection position. The illumination unit 501 and the light detection unit 502 may each include an optical (lens, etc.) system. In this embodiment, a slit is provided to limit the light that enters the photodetector 502, and measurement is performed by allowing only the light flux reflected from a 1 mm diameter area on the recording medium 503 to enter the photodetector 502. . Further, it is desirable that the recording medium 503 be kept flat during measurement. For this reason, the measuring device is provided with means for fixing the recording medium 503, such as suction using an air pump or electrostatic adsorption.

A light detection unit 504 detects light from the illumination unit 501. The light detection unit 502 has the same configuration as the light detection unit 502, and particularly measures the spectral intensity of the illumination unit 501 in order to calculate the glossiness. The spectral intensity of the illumination unit 501 may be measured by using a white plate such as a perfect diffuse reflector or a mirror surface such as a blackboard glass, and measuring the spectral intensity of specularly reflected light by the light detection unit 52. Alternatively, the illumination light may be separated by a beam split or the like and measured by a light detection section different from the light detection section 52. In the present invention, the spectral reflection intensity is calculated by setting the spectral reflection intensity using blackboard glass to 1.

Next, a method of calculating glossiness from the measured reflected light of the recording medium will be explained.
Let the spectral intensity of the reflected light from the recording medium 503 measured by the photodetector 502 be Rx (λ), and from the spectral intensity Rx (λ), the tristimulus value Xx of the specularly reflected light is determined by the following formula (1). , Yx, and Zx are calculated.

However, in the above equation (1), since the optical system of FIG. 5 measures specularly reflected light, the range of measured values is close to the range of measured values of the light source. In other words, it is similar to a measurement system that directly measures light from a light source.

Therefore, unlike the calculation of the tristimulus values of the object color by normal reflection, the spectral intensity of specularly reflected light is regarded as the relative spectral distribution of the light source, and the method for calculating the tristimulus values of the light source color is followed. Note that x (λ), y (λ), and z (λ) in equation (1) are JIS Z 8782 color matching functions. Further, in this embodiment, normalization by multiplication by a proportionality constant is not performed, but normalization such as multiplication by K in equation (2) below may be performed.

From the spectral intensity S(λ) of the illumination measured by the light detection unit 504, the tristimulus values Xs, Ys, and Zs of the illumination are calculated by the following equation (3). Equation (3) is based on a method for calculating the tristimulus values of the light source color, and is a conversion formula for calculating the tristimulus values Xs, Ys, and Zs from the spectral data of the illumination.

In equation (3), x￣(λ), y￣(λ), and z￣(λ) are JIS Z 8782 color matching functions. Further, k in equation (3) is a proportionality constant, and is determined so that the value of Ys of the tristimulus value coincides with the photometric amount.

Next, the tristimulus values Xx, Yx, Zx of the reflection of the recording medium 503 to be evaluated detected by the light detection unit 502 and the tristimulus values Xs, Ys, Zs of the illumination detected by the light detection unit 504 are get. Then, from these tristimulus values Xx, Yx, Zx and tristimulus values Xs, Ys, Zs, the reflected light of the recording medium 503 is calculated based on equations (1) to (4) specified in the JIS Z 8729 standard. Calculate the L*a*b* value in the CIE-Lab color space.

Formulas (1) to (4) specified in the JIS Z 8729 standard are shown, for example, in JIS Handbook Color (January 31, 2001, published by the Japanese Standards Association). However, the tristimulus values (Xx, Yx, Zx) of the specularly reflected light of the recording medium 503 are used for the values of X, Y, and Z in equations (1) to (4) of JIS Z 8729. Furthermore, the tristimulus values (Xs, Ys, Zs) of the light source are used for the values of Xn, Yn, and Zn. That is, the values of L*, a*, and b* are calculated by the following equation (4).

L* derived from the above calculation is defined as glossiness.

(About the relationship between the amount of overlapping glitter ink and glossiness)
This embodiment includes a process of recording a plurality of dots of glitter ink in a superimposed manner on a recording pixel. The present embodiment is characterized in that the overlapping amount of glitter ink dots in each recording pixel is changed depending on the number of connected recording unit areas (recording pixels) in which one dot is recorded with glitter ink. do. In other words, the amount of overlapping glitter ink is changed depending on the area of the area where dots formed by the glitter ink ejected onto the recording medium are connected to each other. More specifically, the smaller the number of connected recording pixels and the smaller the area in which dots of glitter ink are connected, the more dots are recorded in an overlapping manner. On the other hand, in areas where the number of connected recording pixels is large and the area where glitter ink dots are connected is large, the glitter ink is not superimposed or the dots are thinned out so as to reduce the number of overlaps.

FIG. 6 is a diagram showing the relationship between the number of connected pixels recorded with glitter ink, the overlapping amount of glitter ink, and glossiness. Item 601 in FIG. 6A indicates the number of connected recording pixels on the recording medium. For example, "2x2" shown in item 601 indicates that four recording pixels on the recording medium are adjacent, and "4x4" indicates that 16 recording pixels are adjacent. There is. Note that "1×1" indicates a single recording pixel to which glitter ink is applied and a dot is formed.

Furthermore, the black area shown in item 602 in FIG. 6A represents the area corresponding to the number of connections shown in item 601. All pixels corresponding to the black area are composed of recording pixels on which dots are to be recorded. As shown in the figure, the larger the number of connected recording pixels, the larger the area of the black area. Therefore, the area of the black area is maximum in a solid image.

When the glitter ink is used to form a metallic pattern such as glitter or pearl, it is possible to change the metallic texture by changing the number of connected recording pixels. Therefore, it is necessary to change the number of connected recording pixels depending on the desired texture. Item 603 in FIG. 6A is a numerical value indicating the number of times (overlap amount) that dots are recorded in an overlapping manner in the same recording pixel.

The numerical value shown in item 604 in FIG. 6A indicates the degree of gloss obtained when dots are printed 1 to 6 times overlapping each recording pixel for each number of connected recording pixels. Note that here, the measurement was performed in a state where the glitter ink was formed in a uniformly connected pattern, such as a metallic pattern.

FIG. 6(b) shows, as an example, the arrangement of dots in the area indicated by 605 in item 604 of FIG. 6(a), that is, the area where the number of connections is 3×3 and the amount of overlap is 4. As shown in FIG. 6B, in an area 606 made up of nine recording pixels, four dots 607 are formed overlapping each recording pixel. One square shown in FIG. 6A indicates a pixel having a length of 1/1200 inch in length and width, that is, a pixel of 1200 dpi.

Among the glossiness values shown in item 604 in FIG. 6(a), the value that maximizes the glossiness is written in bold. As shown in the figure, high gloss can be obtained by increasing the amount of overlap when the number of connections is small, and by decreasing the number of overlaps when the number of connections is large. This is presumed to be based on the following principle.

FIGS. 7A and 7B are cross-sectional views showing a state in which a solid image (100% duty image) is formed on a recording medium 700 using glitter ink. Figure (a) shows the case where one dot is formed in each pixel (overlap amount 1), and Figure (b) shows the case where four dots are recorded in each pixel (overlap amount 4). are shown respectively. Further, FIG. 7(c) is an enlarged view of FIG. 7(a), and FIG. 7(d) is an enlarged view of FIG. 7(b).

The dot diameter of a dot formed on a recording medium by an ink droplet of approximately 4 ng is approximately 35 μm, which is sufficiently larger than the vertical width and horizontal width (1/1200 inch) of one pixel. Therefore, as shown in FIG. 7A, even when printing is performed with an overlapping amount of 1, the dots overlap to some extent if the duty is 100%. Therefore, in the state shown in FIG. 7(a), metallic luster is sufficiently developed. The glitter ink used in this embodiment is an ink containing silver nanoparticles. When this glitter ink is applied to the surface of a recording medium 700 made of a porous material such as paper, the moisture contained in the glitter ink disappears from the surface of the recording medium 700, causing the silver nanoparticles 702 to bond with each other. Closely fused. This produces metallic luster. At this time, it is presumed that the dispersion polymer and residual solvent 703 used to disperse the silver nanoparticles 702 enter the recording medium 700 together with moisture.

On the other hand, in the area where four dots of glitter ink overlap, enough glitter ink remains on the surface of the recording medium, but in this case too, the silver nanoparticles are closely fused together and form a thicker layer. do. As the layer of silver nanoparticles 702 becomes thicker, the closeness of the silver nanoparticles increases, and the silver nanoparticles are more strongly fused. As a result, the dispersed polymer and residual solvent 703 remain on the silver nanoparticle layer. The dispersed polymer and residual solvent 703 are organic substances and do not have the same level of gloss as metallic luster, so the dispersed polymer and residual solvent remaining on the surface reduce the gloss of the formed image.

FIGS. 8A and 8B are cross-sectional views showing a state in which a dot is formed in one pixel on the recording medium 700 using glitter ink. Figure (a) shows a state in which one dot is formed on only one recording pixel, and figure (b) shows a state in which multiple dots (four dots in the figure) are formed overlapping only in one pixel. It shows. Further, FIG. 8(c) is an enlarged view of FIG. 8(a), and FIG. 8(d) is an enlarged view of FIG. 8(b).

As shown in FIGS. 8(a) and 8(b), when independent dots that are not connected to other dots are formed in the surface direction of the recording medium 800, the glitter ink dots have overlap with the surrounding dots. do not have. Therefore, as shown in FIG. 8(a), when only dots with an overlapping amount of 1 are formed, the particle density of the silver nanoparticles 802 is low, and the particles are sufficiently fused with each other as shown in FIG. 8(c). I don't wear it. The silver nanoparticles used in this embodiment have a particle diameter of several tens of nanometers, which is sufficiently short compared to the length of visible light. Therefore, free electrons do not move sufficiently, making it impossible to achieve strong reflection.

On the other hand, as shown in FIG. 8(b), when four dots are superimposed on independent dots, a sufficient amount of silver nanoparticles 802 are concentrated in one pixel, as shown in FIG. 8(b). , silver nanoparticles are sufficiently bonded to each other, and free electrons can sufficiently move. This results in strong reflection, that is, high metallic luster. Note that in this case, it is assumed that the dispersed polymer and the solvent 803 permeate into the recording medium 800 via the periphery of the dots.

Through the above mechanism, high metallic luster is achieved by reducing the amount of overlapping dots in each recording pixel when there are many connected recording pixels, and increasing the amount of overlapping dots when the number of connected recording pixels is small. It becomes possible to do so. In addition, when the connected state of recorded pixels is 2 pixels vertically and 2 pixels horizontally, even if the amount of overlapping dots for each pixel is 1 dot, compared with independent dots as shown in FIG. As a result, dots of adjacent pixels overlap with each other. Therefore, the amount of overlap required to form dots with optimal metallic luster is smaller than when forming individual dots.

Based on the characteristics of the glitter ink as described above, in this embodiment, an image having excellent glossiness is obtained by performing a recording operation in the following manner. In this embodiment, a mask described below is used to perform mask processing on print data to control the overlapping amount of dots in each pixel. In the above explanation, the size of one pixel is 1200 dpi both vertically and horizontally, but in the following explanation, it is assumed that color ink is printed at a density of 1200 dpi vertically and 2400 dpi horizontally. conduct. As a result, color ink can be recorded at a maximum duty of 200%, and by increasing the amount of color ink applied, it is possible to realize high-density image recording. Regarding the glitter ink, recording is performed at a density of 1200 dpi vertically and 1200 dpi horizontally. That is, in this example, glitter ink is not applied at an output resolution higher than 1200 dpi. However, in controlling the amount of overlapping described below, image data is processed in units of 1200 dpi vertically and 2400 dpi horizontally for both color ink and glitter ink.

(Image processing)
Next, image processing performed in the first embodiment will be described with reference to the flowchart of FIG. 9. In addition, in FIG. 9, "S" attached to the number of each processing step means a step.

In this embodiment, image data corresponding to images (C, M, Y, K images) formed using four color inks (K, C, M, Y) are each 8 bits (0 to 255). Prepare the data. Furthermore, 8-bit image data is prepared as image data corresponding to an image formed using glitter ink.

FIG. 9A is a flowchart showing a procedure for processing K, C, M, and Y image data. In FIG. 9(a), when K, C, M, and Y image data 901 is input, 4-bit data 902 representing 9 values is generated for each pixel according to multi-value quantization processing (S1) such as a dither pattern. generated. This 4-bit data 902 is called index data, and index expansion processing (S2) is performed based on this index data. In the index expansion process, binarized recording data is generated according to the rules shown in FIG. 10(a).

In FIG. 10A, the binary numbers on the left side indicate index data, and the pattern on the right side indicates a dot arrangement pattern (hereinafter also referred to as index pattern) corresponding to the index data. In the figure showing the pattern on the right side of FIG. 10A, the area surrounded by the solid line indicates an area of 600 dpi vertically and 600 dpi horizontally. Also, eight areas (rectangular areas surrounded by broken lines) defined within the area of 600 dpi vertically and 600 dpi horizontally indicate areas of 2400 dpi horizontally and 1200 dpi vertically, and these areas are used for handling recording data. The above pixel (hereinafter referred to as a unit pixel).

Recording data representing an image formed with color ink is generated based on index data shown in FIG. 10(a). For example, in the case of "0001", recording data is generated that forms a dot in one unit pixel at the upper left of eight unit pixels defined in an area of 600 dpi vertically and 600 dpi horizontally. Furthermore, when the index data is "0010", recording data is generated that forms dots in one unit pixel at the upper left and one unit pixel at the lower right among the eight unit pixels. By using such index data, it becomes possible to compress output image data. For example, if the presence or absence of a dot is included as information for all pixels of 2400 dpi horizontally and 1200 dpi vertically, 8 bits of data will be required, but since index data only handles 4 bits of data, data compression becomes possible. .

On the other hand, FIG. 9(b) is a flowchart showing a procedure for processing image data (glitter image data) representing an image (glitter image) formed with glitter ink. As shown in FIG. 9(b), the glitter image data is also processed in substantially the same procedure as the K, C, M, and Y images. That is, the 8-bit glitter image data 906 is quantized by multi-value processing (S11) to become 2-bit index data 908 representing four values. The glitter ink is applied to each of four pixels defined in an area of 600 dpi vertically and 600 dpi horizontally. In other words, the index data 908 is 2-bit data corresponding to a 600 dpi area. Based on this index data 908, index expansion processing is performed in S12. In the index development process S12, binarized recording data 908 is generated according to the rules shown in FIG. 10(b). Also in FIG. 10(b), the binary numbers on the left side indicate index data, and the right side indicates the arrangement of dots corresponding to the index data.

As shown in FIG. 10(b), when the index data is, for example, "01", one unit in the upper left of eight unit pixels defined in an area of 600 dpi vertically and 600 dpi horizontally Recording data for forming dots on pixels is generated. In addition, when the index data is "10", among the eight unit pixels, the leftmost unit pixel among the four unit pixels located at the bottom, and the third unit pixel from the left at the bottom Recording data for forming a dot at the unit pixel located at is generated.

(Recording operation)
In this embodiment, printing is performed using a so-called multi-pass printing method in which main scanning of the printing head 40 is performed multiple times on the same area on the printing medium. In this embodiment, 16-pass printing is performed in which the printing head 40 performs main scanning 16 times on the same area on the printing medium. The multi-pass recording method will be briefly explained below.

In the multi-pass printing method, the image data that can be printed by the print head in one main scan is thinned out according to a mask pattern prepared in advance, and the image is completed in stages by multiple main scans.

FIG. 11(a) is a schematic diagram for explaining the multi-pass printing method. Here, in order to simplify the explanation, a multi-pass printing method will be described as an example in which an ejection port array 110 having 32 ejection ports is used and an image is completed by eight scans (eight passes).

In the case of the 8-pass multi-pass printing method, the ejection port array 110 is divided into eight areas (area 1 to area 8). Each region is composed of four ejection ports. Further, 1101a to 1101h indicate mask patterns used for areas 1 to 8 of the print head, respectively. Each of the mask patterns 1101a to 1101h consists of 4 vertical pixels that define recording permissible pixels (pixels shown in black) that allow recording of dots and non-recording permissible pixels (pixels shown in white) that do not allow recording of dots. , has an area of 4 pixels horizontally (4×4 pixels (16 pixels in total)). By overlapping these mask patterns 1101a to 1101h, the recording permissible pixels are complemented.

When actually recording, a logical product operation is performed between the binary image data corresponding to each ejection port, that is, the recording data representing whether or not a dot is recorded, and the mask pattern, and the result is Based on this, an ink ejection operation is performed at each ejection port. In order to simplify the explanation, a mask pattern having a 4 x 4 pixel area is shown here, but the actual mask pattern can be used both vertically (in the sub-scanning direction), horizontally (in the main scanning direction), and further. Those with large areas are used. Note that in the following description, the main scan performed while ejecting ink by the print head will be referred to as print scan.

1102a to 1102h show how images are completed on the recording medium by repeating recording scans. In each printing scan, areas 1 to 8 of the ejection port array 110 print only to pixels for which printing is permitted by the mask patterns 1101a to 1101h. The recording medium is conveyed in the sub-scanning direction by a corresponding length. With this configuration, an image to be printed on a unit scan area of the print medium (an area on the print medium corresponding to the width of each area of the ejection port array) is completed by eight print scans of the print head.

In this manner, in multi-pass printing, a plurality of different areas in the ejection port array complete an image by sequentially scanning each unit scanning area of the printing medium. Therefore, variations in the ejection characteristics of each ejection port in the ejection port array and variations in the conveyance accuracy of the recording medium are dispersed, and density unevenness and streaks can be reduced.

FIG. 11B is a diagram showing a state in which so-called overlapping recording is performed, in which a plurality of dots are recorded in the same pixel in an overlapping manner by multiple recording scans. In this case as well, as in FIG. 10A, the recording operation is performed based on the recording data obtained by the AND operation of the recording data and the mask pattern. However, in the case of overlapping recording, ink droplets are ejected from ejection ports belonging to different areas to the same pixel during multiple scans, and dots are recorded in an overlapping manner. For example, ink droplets are applied to the pixel 1103 in four print scans out of a total of eight print scans, and four dots are printed in an overlapping manner. Further, at the position of the pixel 1104, ink droplets are applied to the same pixel in three print scans out of a total of eight print scans, and three dots are printed in an overlapping manner. FIG. 10C shows the number of dots recorded in each pixel in a 4×4 pixel (total 16 pixels) area on the recording medium by eight recording scans.

In the actual recording scan, the recorded image is determined by the logical sum of the CMYK image data 905 and the glitter image data 910 obtained by the process shown in the flowchart of FIG. 9, and the mask. That is, when the recording data of FIG. 10(b) exists at the position 1103, overlapping recording is performed four times.

FIG. 12 is a diagram showing how an image is printed by the multi-pass printing method using the print head 40 shown in FIGS. 3 and 4. In FIG. In the example shown in FIG. 12, the ejection port array of the print head 40 scans the same location on the print medium 16 times. However, the image to be printed with the glitter ink is printed by eight printing scans using only the area 403 in the ejection port array. Further, an image to be printed with color ink is printed by eight printing scans using the ejection port area 402. In this way, the ejection port array of the print head performs 8 print scans with printing and 8 main scans without print with respect to the same scanning area, so here, this multi-pass print is called the 16 pass record. Note that in this specification, scanning by the print head means that the print head moves in a direction that intersects with the conveyance direction of the print medium (in this embodiment, a direction perpendicular to it (main scanning direction)). It does not matter whether ink is ejected from the print head or not. On the other hand, the above-mentioned printing scan means that the printing head moves in the main scanning direction while ejecting ink, and is distinguished from simple scanning.

FIG. 12(a) shows a state in which the first printing scan is performed on an area 1201a corresponding to the array width of 96 ejection ports by the upstream ejection port array 403 that ejects glitter ink. There is. When the first printing scan is completed, the printing medium 104 is conveyed in the sub-scanning direction by a distance corresponding to the array width of the 96 ejection ports, and then the main scanning of the printing head 40 is performed again. By repeating this conveyance (sub-scanning) of the recording medium and the main scanning of the recording head 40, images are recorded in stages.

FIG. 12(b) shows a state where the ninth recording scan has been performed. From the first print scan to the ninth print scan shown in FIG. 12A, eight print scans are performed on the print area 1201a of the print medium 104 by the upstream ejection port array 403. Through these eight recording scans, a glitter image to be recorded in the recording area 1201a is completed. Then, from the ninth recording scan shown in FIG. 10(b), recording of a color image is started by the downstream ejection port array 402, and a color image is formed on the layer of the glitter ink image that has already been formed. be done. A color image is completed by eight recording scans from the 9th to the 16th. As described above, a metallic color image is formed by the glitter ink and the color ink that overlaps thereon.

FIGS. 13A to 13C are diagrams showing the ejection opening array of the print head 40 and the mask pattern of the mask, which are applied to 16-pass printing in this embodiment. In FIG. 13, an ejection port array 1910 is an ejection port array that ejects glitter ink. Furthermore, the ejection port array 1920 is an ejection port array that ejects color ink. In this embodiment, four ejection port arrays 1920 are arranged corresponding to each of four color inks (black ink, cyan ink, magenta ink, and yellow ink).

Each of the ejection port arrays 1910 and 1920 provided in the recording head 40 is divided into 16 regions R1 to R16 in the sub-scanning direction (F direction), and each region has 96 ejection ports e. is located. When recording with glitter ink, recording is performed by ejecting the glitter ink from the ejection ports e in the ejection area 1911 consisting of regions R1 to R8. Furthermore, when recording is performed using color ink, the color ink is discharged from the discharge ports e in the discharge region 1921 consisting of regions R9 to R16 to perform recording.

Further, when recording a glitter image, a mask 1903 shown in FIG. 13(c) is used, and when recording a color image, a mask 1904 shown in FIG. 13(d) is used. Each of the masks 1903 and 1904 is arranged in a complementary manner so that dots can be recorded in all pixels by eight recording scans. It has a mask pattern in which squares are arranged. Here, mask patterns 1904a to 1904h of the mask 1904 correspond to regions R9 to R16 of an ejection port array 1920 that ejects color ink, and mask patterns 1903a to 1903h of the mask 1903 correspond to an ejection port array that ejects glitter ink. 1910, corresponding to regions R1 to R8, respectively. The masks 1903 and 1904 control the order in which ink is applied to each pixel on the recording medium and the amount of overlapping.

In this embodiment, in the printing operation using color ink, ink dots of the same color are not printed in an overlapping manner for each pixel. On the other hand, when recording is performed using glitter ink, as described in the example of FIGS. 11(b) and 11(c), dots may be recorded in an overlapping manner for the same pixel. For this reason, the mask 1903 used for glitter ink includes one in which recording pixels (black squares) are arranged at overlapping positions. Note that the masks 1903 and 1904 shown in FIGS. 13(b) and 13(c) show mask patterns of 4 pixels vertically and 4 pixels horizontally (4×4 pixels), but in this embodiment, the mask patterns are simply A mask is used in which a 4×4 pixel mask pattern is repeated vertically and horizontally.

(Relationship between ink application amount and overlapping amount)
As described above, in this embodiment, the index pattern shown in FIG. 10(b) is used as the index pattern for determining the arrangement of dots based on the index data. Although FIG. 10(b) shows an index pattern corresponding to an area of 2 pixels vertically and 4 pixels horizontally, here, the index pattern shown in FIG. 10(b) is simply shown in the vertical and horizontal directions. Let me repeat this.

14(a) to (c) show recording operations performed using recording data generated by the index pattern shown in FIG. 10(b) and mask patterns shown in FIGS. 13(b) and (c). FIG. 4 is a diagram showing the arrangement and overlapping amount of glitter ink dots formed in each pixel.

When recording with a duty of 25%, the index data becomes "01". Further, as the index pattern, one in which a dot is formed at one pixel in the area (600 dpi vertically x 600 dpi horizontally) surrounded by the solid line in FIG. 10(b) is used. That is, among the four index patterns shown in FIG. 10(b), the index pattern with the lowest gradation is used.

The index pattern shown in FIG. 10(b) and the mask pattern shown in FIG. 13(c) are synchronized, and the dot formation position of the index pattern with the lowest gradation (position 1001 in FIG. 10) is This corresponds to the position of pixel 1905 in mask 1903 shown in FIG. 13(c). Therefore, dots are printed four times in an overlapping manner on the pixel 1905 through eight printing scans.

FIG. 14(a) is a diagram showing the state of dot recording when recording is performed at 25% duty. When recording is performed at 25% duty, dots are recorded at isolated positions in the surface direction of the recording medium. In this case, the number of connected recording pixels on which dots are recorded is 1×1 as shown in FIG. 6(a), and dots are recorded four times overlappingly on the same recording pixel. Thereby, as shown in FIG. 6(a), a preferable glossiness can be obtained.

Further, when recording is performed at 50% duty, the index data becomes "10" (see FIG. 6(b)), and recording data of an index pattern corresponding to this is generated. By performing eight printing scans according to the combination of this print data and mask pattern 1905, the actual dot printing state becomes as shown in FIG. 14(b). In this case, three dots are recorded in an overlapping manner for each recording pixel. In the case of the dot arrangement shown in FIG. 14(b), the amount of overlap between adjacent dots in the surface direction of the recording medium is smaller than that in the case where the number of connected recording pixels is 2×2 as shown in FIG. 6(a). It will be slightly less. However, even with the dot arrangement shown in FIG. 14(b), it was confirmed that preferable glossiness could be obtained by recording three dots in each recording pixel in an overlapping manner. Therefore, when printing at 50% duty, the mask pattern is set so that dots are printed three times overlapping each other.

Further, when recording is performed at 100% duty, the index data is "11", and dots are arranged according to the combination of the index pattern and mask pattern corresponding to this. As a result, the actual arrangement of dots becomes as shown in FIG. 14(c). As shown in the figure, at 100% duty, adjacent dots are connected to each other in the surface direction of the recording medium, so dots are not recorded overlapping each other. This makes it possible to obtain good reflection intensity. That is, in a state where the dots are connected to each other as shown in FIG. 14(c), the metal particles are connected to each other, so that free electrons can sufficiently move. Furthermore, since dots are not recorded in an overlapping manner, the amount of dispersed polymer and solvent remaining on the upper surface of the metal particles can be suppressed. Therefore, good reflection intensity can be obtained.

(Comparison between this embodiment and conventional technology)
FIG. 15 is a diagram showing the relationship between the recording rate (duty) of glitter ink and gloss when recording a glitter image on a recording medium. The horizontal axis represents the recording rate of glitter ink, and the vertical axis indicates the glossiness. Further, in FIG. 15, the solid line indicates a recording example according to this embodiment, and the broken line indicates a recording example according to the conventional technique. In the conventional technology, a plurality of dots are not recorded in a superimposed manner on one recording pixel, but one dot is recorded on each recording pixel. On the other hand, in this embodiment, printing is performed by changing the overlapping amount of dots according to the duty as described above.

In both the present embodiment and the prior art, the glossiness of an area recorded with a low duty is lower than the glossiness of an area recorded with a high duty (for example, 100% duty). This is because there are areas where glitter ink is not applied in areas recorded at low duty. However, in this embodiment, dots are formed overlappingly in areas (recorded pixels) that are recorded at low duty, so compared to the conventional technology in which only one dot is formed in one recording pixel, A recorded pixel in which dots are recorded in an overlapping manner exhibits a strong reflection intensity. Therefore, the glitter image formed according to this embodiment has a higher degree of gloss than the glitter image formed by the conventional technique.

In this embodiment, the color ink is applied up to a duty of 200%, whereas the glitter ink is applied only up to a duty of 100%. This is because when recording is performed at 100% duty, the surface of the recording medium is covered with metal particles, and if more is added than this, the dispersed polymer and solvent tend to remain on the surface, and the gloss level decreases. It's for a reason.

Furthermore, in this embodiment, the amount of overlapping dots is changed to 4, 3, and 1 to correspond to the index data values ("01", "10", and "11"). This overlapping amount is a value experimentally set to give the highest gloss. Therefore, depending on the composition of the ink, the recording medium, etc., the value of the overlapping amount may be changed.

[Second embodiment]
Next, a second embodiment of the present invention will be described. In the first embodiment described above, an example was shown in which the amount of overlapping dots is determined using the mask shown in FIG. 13 for the index pattern corresponding to the index data. On the other hand, in the second embodiment, the amount of overlap of dots for each recording pixel is determined based on the arrangement of recording pixels in which actual glitter ink dots are to be recorded.

In this embodiment as well, similarly to the first embodiment, print data of an image to be printed using glitter ink is generated by the process shown in FIG. The generated recording data is stored in the buffer 209LU in FIG. 2. Note that here, the recording resolution using the glitter ink is 1200 dpi in both the vertical and horizontal directions. That is, the size of the recording unit area (pixel) is set to 1200 dpi. In this embodiment, the number of connections of each recording pixel is determined based on the number of consecutive recording pixels in the vertical direction and the number of consecutive recording pixels in the horizontal direction based on the recording data of the image to be recorded from now on, which is stored in the buffer 209LU. The amount of overlap of dots is determined based on the number of connections. A specific method will be explained below.

FIG. 16 is a diagram showing a part of an image to be recorded with glitter ink. One square shown in FIG. 16 indicates pixels of 1200 dpi vertically and horizontally, black pixels represent pixels where dots are recorded (recorded pixels), and white squares represent pixels where dots are not recorded. (non-recorded pixels).

In the example shown in FIG. 16(a), scanning is started from the print data corresponding to pixel 1601, and the scanned print data is either data that prints dots (dot data) or data that does not form dots (non-dot data). ). If it is determined that the data is dot data, the number of consecutive recording pixels is obtained by counting the number of consecutive dot data. For example, in the area indicated by 1602, two recording pixels are consecutive in the horizontal direction. Therefore, the print data corresponding to two pixels in the horizontal direction of the area 1502 is two consecutive dot data. By counting these two consecutive dot data, the number of consecutive recording pixels in the horizontal direction of the area 1502 is determined to be two. Subsequently, the recorded data is also scanned in the vertical direction of the image, and the number of consecutive recorded pixels in the vertical direction is obtained. For example, in the above-mentioned area 1502, there are two consecutive recording pixels in the vertical direction. Therefore, two pieces of dot data corresponding to a recording pixel are consecutive in the vertical direction, and by counting these consecutive dot data, the number of consecutive recording pixels in the vertical direction of the area 1502 is determined to be two.

Based on the number of consecutive recording pixels in the horizontal direction (horizontal consecutive number) and the number of consecutive recording pixels in the vertical direction (vertical consecutive number) obtained in this way, the number of connected recording pixels is determined as follows. Calculate as follows.
Number of connections = number of horizontal rows x 0.5 + number of vertical rows x 0.5 (Formula 5)

The reason for multiplying by 0.5 is to offset the fact that the number of connections finally obtained is doubled by the number of vertical connections and the number of horizontal connections. In FIG. 16(b), the numerical value written in the area where dots are to be recorded indicates the number of connections determined by the calculation of Equation 5 based only on the number of consecutive recording pixels in the horizontal direction. Further, FIG. 16(c) shows the number of connections calculated by the calculation of Equation 5 based on the number of horizontal continuations and the number of vertical continuations.

Next, the amount of overlapping dots in each pixel is determined based on the number of connections obtained as described above. Table 1 is a diagram showing the relationship between the number of connections and the amount of overlap. According to Table 1, a preferable overlap amount is set according to each number of connections.

Through the above processing, the amount of overlapping dots is determined for each recording pixel.

(Recording operation)
In the second embodiment, 12-pass printing is performed. Color ink uses 1024 ejection ports that are compatible with 8-pass printing, and each glitter ink uses 512 ejection ports that are compatible with 4-pass printing. The recording operation in this embodiment will be described below based on FIG. 17.

FIG. 17A is a diagram showing a state in which the first printing scan has been completed by the ejection port array that ejects glitter ink. In this embodiment, a printing operation is performed on print data of an image to be printed using glitter ink according to a pre-obtained overlap amount without using the mask shown in FIG.

FIG. 17(a) shows a state in which the first recording scan has been completed. In this first printing scan, dots are printed on all printing pixels existing within the area 1701a.

FIG. 17(b) is a diagram showing a state in which the second recording scan is completed. In the second printing scan, only pixels in which the overlapping amount of glitter ink dots is 2 or more are printed in the area 1701a. Printing on this area 1701a is performed using area 403 in ejection port array 401LU. Furthermore, in the third printing scan, dots are printed only on the printing pixels where three or more dots overlap, and in the fourth printing scan, dots are printed only on the printing pixels where four dots are overlapped. By performing the recording operation as described above, it becomes possible to record a glittering image with the amount of overlapping dots recorded in Table 1. Thereafter, 8-pass printing is performed using areas 402 in the ejection port arrays 401K, 401C, 401M, and 401Y that eject color ink.

As described above, in the second embodiment as well, dots are formed with an overlapping amount depending on the number of connected recording pixels, so as in the first embodiment, glitter images and metallic color images with good glossiness are formed. can be formed.

[Third embodiment]
Next, a third embodiment of the present invention will be described. In this embodiment, an example will be shown in which dots of glitter ink are recorded in a predetermined pattern for each tone of an image to be formed. When glitter ink is used for decoration, the size of the area formed by the glitter ink (the number of connected recording pixels) is often predetermined. For example, in a pearl-like image with fine metal decoration, the number of connected pixels for recording dots (recording pixels) is set to a small value, and in a lame or metallic-like image with large metal decoration, the number of connected recording pixels is set to a small value. is set to a large value. Furthermore, the type and amount of color ink applied over the glitter ink are often fixed. In this embodiment, when the number of connected recording pixels for recording dots using glitter ink is fixed in advance for each tone (pattern) of the image to be formed, dots are printed in an overlapping amount determined for each pattern. Make a record.

Table 2 shows an example of a recording pattern of glitter ink that is selected in advance by the user.

As shown in Table 2, in this embodiment, pearl pattern 1, pearl pattern 2, glitter pattern 1, glitter pattern 2, and glitter pattern 3 are listed as patterns recorded with glitter ink. For each pattern, a preferable number of connected recording pixels in which dots formed using glitter ink are recorded, and a preferable amount of overlapping of dots corresponding to the number of connections are predetermined. Furthermore, depending on the overlapping amount of glitter ink dots, the number of ejection ports used to eject the glitter ink (the length of the ejection port row) and the number of ejection ports used to eject color ink (the length of the ejection port row) are determined. The length of the column is determined. In other words, when the amount of overlapping dots of glitter ink is large, the number of ejection ports used to eject the glitter ink increases, and the number of ejection ports used to eject color ink is set to decrease. ing.

For example, when recording an image of pearl pattern 1, the number of connected recording pixels is set to 1×1, and the overlapping amount of glitter ink dots is set to 4. Furthermore, it is also specified that four recording scans with glitter ink are performed using 512 ejection ports 402, and eight recording scans with color ink are performed using 1024 ejection ports.

Further, when recording an image of pearl pattern 2, the number of connected recording pixels for recording glitter ink dots is set to 2×2, and the overlapping amount of glitter ink dots is set to 4. In this case, it is specified that 417 ejection ports are used for three printing scans with glitter ink, and 1112 ejection ports are used for printing with color ink. FIG. 18 is a flowchart showing a method of creating data for recording an image using predetermined glitter ink as described above.

When the user selects a pattern to be formed, data 1807 for recording a metallic color image and data 1808 for recording a glitter image are read out according to the selected pattern (S31). Here, the data 1808 includes binary glitter image data (recording data) 1809 for recording a glitter image determined according to the selected pattern, and predetermined glitter ink dots. Data representing the amount of overlap is included. Further, data 1807 is binary color image data for a metallic color image for recording dots of color ink on dots of a glitter image. This color image data is defined by binary image data 1809 of glitter ink.

On the other hand, generation of binary print data for printing a color image is performed as follows. First, as in FIG. 9A, multi-value quantization processing (S21) and index development processing (S22) are executed to generate C, M, Y, and K binary color image data. Next, the binary image data generated in S22 and the binary color image data 1807 defined in the glittering image data 1808 described above are subjected to a logical sum calculation process (S23). As a result, binary image data (recorded data) 1805 corresponding to a color image is generated. A metallic color image is recorded based on the recording data 1805 corresponding to the color image recorded with the color ink generated as described above and the recording data corresponding to the glittering image recorded with the glittering ink. be exposed.

(Recording method)
FIG. 19 is a diagram showing a recording operation performed when pearl pattern 2 is selected as an example of the pattern shown in Table 2. In this embodiment as well, dots are recorded without performing mask processing on the image data of the glitter ink, as in the second embodiment described above. However, in this embodiment, dots are repeatedly recorded on all pixels to be recorded with glitter ink according to a predetermined amount of overlap.

FIG. 19A shows a state in which printing with glitter ink has been completed in the area 1901a by the first printing scan, and immediately before the second printing scan starts. In this state, among the pixels in the area 1901a, one dot of the glitter ink is recorded for every recording pixel in which a dot of the glitter ink is to be recorded. After that, in the area 1901a, dots of glitter ink are printed in an overlapping manner in each of the second printing scan and the third printing scan. FIG. 19(b) shows a state where the third recording scan has been completed. At this stage, three dots of glitter ink are recorded in each recording pixel in the area 1901a in an overlapping manner. Then, application of color ink is started in the next printing scan.

As described above, in this embodiment, color ink is applied after three dots of glittering ink are printed in an overlapping manner by three printing scans. As a result, the pearl pattern 2 defined in Table 2 is recorded. By performing the recording operation in accordance with the contents defined in Table 2 in this manner, it is possible to record a highly glossy image as in the first embodiment and the second embodiment.

In this embodiment, an example is shown in which the number of recording scans is the same as the overlapping amount of glitter ink dots. That is, in the case of printing three dots in an overlapping manner, an example has been shown in which printing scans are performed three times. However, by using a mask as shown in FIG. 11, it is also possible to print dots with an overlapping amount that is different from the number of printing scans. For example, it is also possible to perform printing in which three dots are overlapped by four or more printing scans.

[Fourth embodiment]
In the first to third embodiments, an example was shown in which dots of glitter ink are printed in an overlapping manner by repeating main scanning and sub-scanning. However, if the recording apparatus has the configuration as shown in FIG. 20, it is possible to record dots of glitter ink in an overlapping manner even with only sub-scanning, and it is possible to record an image with good glossiness as in the above embodiment. can be formed.

FIG. 20 is a perspective view showing a so-called full-line type printing apparatus 2000 that performs printing using a printing head 2002 having a length corresponding to the entire width of a printing medium. In this embodiment, the printing apparatus 2000 performs a printing operation using glitter ink and color ink.

The printing apparatus 2000 has five types of print heads 2002LU, 2002C, 2002M, 2002Y, and 2002K as print heads 2002 that print on a print medium 2001 in the sub-scanning direction (F direction), which is the conveyance direction of the print medium. They are arranged side by side. These recording heads 2002LU, 2002C, 2002M, 2002Y, and 2002K are capable of ejecting glitter ink, cyan ink, magenta ink, yellow ink, and black ink, respectively. In each print head, a plurality of ejection port arrays each consisting of a plurality of ejection ports arranged over the entire width of the print area are arranged in a plurality of rows along the sub-scanning direction, which is the conveyance direction of the print medium. The recording head 2002 having the above configuration is held at a fixed position during recording operation.

Further, the printing apparatus 2000 in this embodiment is provided with a conveyance belt 2003 as a conveyance means for conveying the recording medium in the sub-scanning direction (F direction). The conveyor belt 2003 is constituted by an endless belt that circulates. The recording medium 2001 supplied from the paper feed guide 2004 is continuously transported toward the paper discharge guide 2005 by the movement of the transport belt 2003. The print head 2002 prints an image on the transported print medium by ejecting ink droplets from its ejection ports.

In this embodiment, each print head has eight ejection port arrays. Therefore, while the print medium passes through each print head once by the conveyor belt 2003, it is possible to perform printing equivalent to eight print scans in a serial type printing apparatus. Therefore, during one transport operation of the print medium 2001, a maximum of eight dots can be printed overlappingly on the same pixel using the eight ejection port arrays provided in the print head 2002LU. Therefore, similarly to the first to third embodiments described above, images with excellent gloss can be recorded at high speed.

Furthermore, even in a full-line printing apparatus having a printing head with one row of ejection ports for each ink, if printing is performed while moving the printing medium 2001 forward and backward, It is possible to record dots of glitter ink in an overlapping manner.

[Fifth embodiment]
Next, a fifth embodiment of the present invention will be described with reference to FIG. 21. FIG. 21 is a schematic diagram showing the arrangement of the ejection ports 2103 in the print head 2100 used in the printing apparatus of this embodiment. In the recording head 2100, ejection ports 2103 for glittering ink are two-dimensionally arranged. In the figure, the area indicated by the broken line indicates the recording medium 2101. As shown, the ejection ports 2103 are arranged in an area covering the entire area of the print medium 2101, and printing with glitter ink is completed without relative movement between the print medium 2101 and the print head 2100. At this time, if there are locations (pixels) with low connectivity in the image, ink is applied multiple times from the ejection port 2103 that is responsible for recording to that location, thereby recording multiple dots in an overlapping manner. can do.

As described above, in this embodiment, an image is printed while the print head 2102 in which the ejection ports 2103 are arranged two-dimensionally and the print medium 2101 are each held in a fixed position. Therefore, deviations in the relative positions of the print head 2102 and the print medium 2101 are unlikely to occur, making it possible to realize high-definition printing. Therefore, the recording apparatus of this embodiment is effective when high-definition recording is required.

For example, when forming a circuit on a recording medium, it is necessary to maintain the relative position of the recording medium 2101 and the recording head 2100 with high accuracy in the horizontal and vertical directions. In particular, it is necessary to make the distance between the recording medium 2101 and the recording head 2100 as close as possible. According to this embodiment, printing can be performed without performing printing scanning, so it is possible to shorten the distance between the printing head 2100 and the printing medium 2101. Therefore, the required high-definition recording can be performed. Additionally, when it is necessary to bond metal particles together in circuit recording, etc., it is possible to record dots in overlapping locations (pixels) with low connectivity, resulting in excellent accuracy and reliability. It is possible to achieve accurate records.

[Other embodiments]
Furthermore, in the embodiments described above, when recording dots of glitter ink in an overlapping manner, an example was shown in which glitter ink is applied multiple times to the same pixel. However, when dots of glitter ink are overlapped, glitter ink may be applied not to the same pixel but to a plurality of pixels that are closest to each other. For example, if the horizontal resolution (horizontal resolution) is increased to 4800 dpi, even if ink is applied to adjacent pixels, it is possible to obtain approximately the same dot overlap as when ink is applied to the same pixel multiple times, and as described above. Good gloss can be obtained similarly to the embodiment.

104 Recording medium 40, 2002, 2100 Recording head (recording means)
100, 200, 2000 Recording device 201 System controller 210 Recording control unit

Claims (16)

A recording device having a recording means capable of applying glitter ink to each of a plurality of unit areas set on a recording medium,
The amount of the glitter ink applied to each of the recording unit areas is changed according to the number of connected recording unit areas, which are unit areas to which the glitter ink is to be applied, among the plurality of unit areas. comprising a recording control means for controlling the recording means,
The recording control means is configured to apply an amount of the glitter ink to the recording unit area when the number of connected recording unit areas is a predetermined number of connections to the recording unit areas whose number of connections is greater than the predetermined number of connections. A recording apparatus characterized in that the recording means is controlled so that the applied amount of the glitter ink is greater than or equal to the amount applied. The recording control means controls the amount of ink applied by the recording means so that the glossiness of the glitter image formed by the glitter ink applied to the recording unit area is maximized. The recording device according to claim 1. The recording means is constituted by a recording head in which a plurality of ejection ports capable of ejecting glitter ink are arranged in a recording unit area set on the recording medium,
The recording control means is configured to record a number of connections in which the number of times the glitter ink is ejected to the recording unit area is greater than the predetermined number of connections when the number of connections of the recording unit area is a predetermined number of connections. 3. The recording apparatus according to claim 1, wherein the recording head is controlled so that the number of times the glitter ink is ejected to a unit area is greater than or equal to the number of times the glitter ink is ejected to a unit area. The recording control means performs a recording scan for ejecting the glitter ink a plurality of times on the same area on the recording medium while moving the recording means in a predetermined main scanning direction. 3. The recording apparatus according to claim 1, wherein the glitter ink is ejected to existing recording unit areas at a number of recording scans corresponding to the number of connected recording unit areas. The recording control means includes recording data indicating whether or not to cause the glitter ink to be ejected from the ejection ports to each of a plurality of unit areas set on the recording medium, and a record data indicating whether or not the glitter ink is to be ejected from the ejection ports to each of a plurality of unit areas set on the recording medium; 4. The method of claim 3, wherein the ejection of the glitter ink to the recording unit area is controlled in each of a plurality of recording scans based on a logical product with a mask pattern that defines ejection ports that permit the discharge of the glitter ink. Recording device as described. The mask pattern is a recording unit whose number of connections is greater than the predetermined number of connections, when the number of connections of the recording unit areas is a predetermined number of connections, and the number of times the glitter ink is ejected to the recording unit area is greater than the predetermined number of connections. 6. The recording apparatus according to claim 5, wherein the number of times the glitter ink is ejected to the area is determined to be greater than or equal to the number of times the glitter ink is ejected to the area. The recording control means includes:
By scanning recording data indicating whether or not to apply the glitter ink to each of a plurality of unit areas defined on the recording medium, recording unit areas adjacent to each of the recording unit areas are determined. an acquisition means for acquiring the number of connections with
determining means for determining the number of times ink is applied to each of the recording unit areas based on the number of consecutive unit areas acquired by the acquisition means;
7. The recording apparatus according to claim 1, wherein glitter ink is applied to each of the recording unit areas according to the number of times determined by the determining means. The acquisition means acquires a first consecutive number of recording unit areas by scanning recording data corresponding to the plurality of unit areas arranged along a first direction of the recording medium, and A second consecutive number of unit areas is obtained by scanning recorded data corresponding to the plurality of unit areas arranged along a second direction of the medium, and the first consecutive number and the second 8. The recording apparatus according to claim 7, wherein the number of connections for each unit area is set based on the number of consecutive units. The recording control means performs the recording scan on the unit area a number of times in accordance with information indicating the position of the recording unit area and the number of connections of the unit area determined in advance on the recording medium. The recording device according to claim 4, characterized in that: Further comprising a conveying means for conveying the recording medium,
The recording means is constituted by a recording head having an ejection opening array in which a plurality of ejection openings for ejecting glitter ink are arranged along the conveying direction of the recording medium,
The recording control means divides the ejection port array into a plurality of ejection areas, and transports the conveying means for each length corresponding to the ejection area, and divides the ejection port array into different ejection areas for the same area of the recording medium. 10. A glittering image is recorded in the same unit area by ejecting glittering ink while scanning a plurality of times along a direction intersecting the conveying direction. The recording device according to any one of the items. Further comprising a conveyance means for conveying the recording medium,
The recording means is constituted by a recording head in which a plurality of ejection port rows each including a plurality of ejection ports arranged along a direction perpendicular to the transport direction of the recording medium are arranged along the transport direction,
The recording control means may cause the plurality of ejection port arrays to eject glitter ink onto the recording medium while causing the conveyance means to continuously convey the recording medium in the conveyance direction. The recording device according to any one of items 1, 2, 3, 5, and 6. Further comprising a conveying means for conveying the recording medium,
The recording means includes an ejection port array in which a plurality of ejection ports for ejecting glitter ink over a length greater than or equal to the length of the recording medium in a direction perpendicular to the transport direction are arranged in a direction intersecting the transport direction. consisting of at least one recording head,
The recording control means causes a plurality of glitter inks to be superimposed on the unit area by ejecting the glitter ink from the ejection port array while moving the recording medium forward and backward along the transport direction. The recording device according to any one of claims 1, 2, 3 , 5, and 6, characterized in that the recording device is capable of imparting the information by using the recording device. The recording means has a plurality of ejection ports arranged two-dimensionally so as to cover the entire area of the recording medium, and the recording device has a plurality of ejection ports arranged two-dimensionally so as to cover the entire area of the recording medium, and the recording device has a plurality of ejection ports arranged in a two-dimensional manner so as to cover the entire area of the recording medium. 7. The recording apparatus according to claim 1 , wherein a glittering image is recorded on the recording medium by ejecting the glittering ink. The recording means is capable of ejecting color ink to each of a plurality of unit areas set on the recording medium,
13. The recording control means, after applying the glitter ink onto the recording medium, applies the color ink onto the recording medium to which the glitter ink has been applied. The recording device according to any one of the items. 15. The recording apparatus according to claim 1, wherein the glitter ink is an ink containing metal particles. A recording method for forming a glittering image by applying glittering ink onto a recording medium, the method comprising:
When the number of connected recording unit areas to which the glitter ink is applied is a predetermined number of connections, the amount of the glitter ink to be applied to the recording unit area is set to a recording unit area whose number of connections is larger than the predetermined number of connections. A recording method characterized in that the amount of the glitter ink applied to the surface is equal to or greater than the amount of the glitter ink applied to the surface.

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