JP5444664B2 - Printing method and apparatus - Google Patents

Description

  The present invention relates to a printing apparatus and a printing method for printing an image using a special gloss ink having a special gloss and a plurality of types of color inks.

  In recent years, not only high-quality color printing using color inks but also various printing methods that provide metallic luster by using metallic inks in combination with color inks have been proposed (for example, Patent Document 1).

JP 2006-50347 A JP 2006-50339 A

  In this patent publication, color conversion is performed to a so-called CMYK of a color ink type used in the former in a print area using only color ink and a so-called spot color area in which a print area using color ink is superimposed on a print area using metallic ink. In the latter case, the metallic ink is treated in the same way as the color ink and converted to CMYK and another five colors, or the metallic ink is converted into a specific color conversion mode of CMYK using tag information or the like. ing. After performing such color conversion, printing with color ink is performed after printing with metallic ink, thereby obtaining a special color region in which a printing region with color ink is superimposed on a printing region with metallic ink. When the printed image is observed from the side of the printed surface, the color ink print area overlaps the metallic ink print area in the special color area, so that the color ink color is observed with a metallic feeling in the special color area. Will be.

  By the way, in the above-described special color area, the metallic ink is expressed by the printing area by the metallic ink being the lower layer side of the printing area by the color ink. Therefore, the current situation is that it cannot be determined that printing by ink ejection in a special color area using metallic ink in the same way as color image printing by color mixing of ejected color inks will necessarily contribute to the appearance of metallic feeling. .

  In light of the above-described problems, the present invention provides a new printing method that contributes to securing a texture such as a metallic feeling in a printed image using a combination of a unique ink such as a metallic ink and a plurality of types of color inks. Objective.

In order to achieve at least a part of the above object, the present invention adopts the following configuration.
A printing apparatus that prints an image using a special gloss ink having a special gloss and a plurality of types of color inks,
Special gloss printing means for discharging the special gloss ink and performing special gloss printing;
Color printing means for performing color printing by discharging the plurality of types of color ink for each color; and
A data classifying unit that classifies image data to be printed into data of a special gloss area that is an area to which the special gloss ink is allocated and data of a color single area to which only color ink is allocated;
A first color conversion for color-converting the image data in the divided special gloss area in color conversion so as to reproduce the color of the image data to be printed using the plurality of types of color inks; and the color alone The second color conversion for color-converting the image data in the area is executed for each of the divided areas so that the amount of color ink used when reproducing the same color represented by the image data is reduced by the first color conversion. A color converter to
The color printing unit and the special gloss printing unit are controlled to print the image data through ejection of the color ink obtained by the color conversion and the special gloss ink for each of the divided areas. Printing control means for performing
The color conversion unit performs color conversion with reference to different color conversion tables for the first color conversion and the second color conversion, and the color conversion table for the first color conversion includes the special glossy ink and the dark color. The second color conversion table has the property of performing color conversion to light color ink in addition to the dark color system. In addition, the following configuration can also be adopted.

[Application 1: Printing device]
A printing apparatus that prints an image using a special gloss ink having a special gloss and a plurality of types of color inks,
Special gloss printing means for discharging the special gloss ink and performing special gloss printing;
Color printing means for performing color printing by discharging the plurality of types of color ink for each color; and
A data classifying unit that classifies image data to be printed into data of a special gloss area that is an area to which the special gloss ink is allocated and data of a color single area to which only color ink is allocated;
A first color conversion for color-converting the image data in the divided special gloss area in color conversion so as to reproduce the color of the image data to be printed using the plurality of types of color inks; and the color alone The second color conversion for color-converting the image data in the area is executed for each of the divided areas so that the amount of color ink used when reproducing the same color represented by the image data is reduced by the first color conversion. A color converter to
The color printing unit and the special gloss printing unit are controlled to print the image data through ejection of the color ink obtained by the color conversion and the special gloss ink for each of the divided areas. And a printing control means for performing the above.

  The special glossy ink exhibiting special gloss referred to in the present application is an ink exhibiting special gloss on the surface of the print medium that has undergone printing, and can be a texture-expressing ink containing a pigment that exhibits a predetermined texture. A metallic ink, which is an example of such a special gloss ink, contains a metallic pigment that develops a metallic feeling after fixing on the surface of a printing medium. In addition to this, a special glossy ink is a pearly luster ink containing a pigment that expresses a pearly luster after fixing on the medium surface, for example, a pigment in which a plurality of thin film layers having a pearl color like natural pearls are stacked, Also included are lamainques and plain inks containing pigments with minute irregularities so as to cause irregular reflection after fixing on the medium surface and express a so-called lame or plain feeling. The metallic ink, which is one of the special glossy inks referred to in the present application, is an ink having a metallic gloss, and the metallic gloss is expressed by a metal pigment contained in the metallic ink. As such a metallic ink, an oil-based ink composition containing a metal pigment, an organic solvent, and a resin can be used. In order to effectively produce a metallic luster, the above-mentioned metal pigment is preferably a tabular grain, and the major axis on the plane of the tabular grain is X, the minor axis is Y, and the thickness is In the case of Z, the 50% average particle diameter R50 of the equivalent circle diameter obtained from the area of the XY plane of the tabular grains is 0.5 to 3 μm, and the condition of R50 / Z> 5 is satisfied. preferable. Such a metal pigment can be formed of, for example, aluminum or an aluminum alloy, or can be formed by crushing a metal vapor-deposited film. The concentration of the metal pigment contained in the metallic ink can be, for example, 0.1 to 10.0% by weight. Of course, the metallic ink is not limited to such a composition, and any other composition can be appropriately employed as long as the metallic gloss is generated.

  In addition, the special glossy ink can be an ink in which the optical characteristics of the ink printed on the surface of the medium have a reflection angle dependency, and the metallic feeling of the metallic ink which is an example of these special glossy inks From a viewpoint, it is as follows. Since the metallic sensation is a sensation of looking at the reflected light, various indexes indicating the metallic sensation have been proposed that have reflection angle dependency in optical characteristics. Therefore, it is possible to define a metallic ink that expresses a metallic feeling with this index. For example, a known metallic feeling index value In1 represented by the following formula (1) may be used. This metallic sensation index value In1 measures the brightness of reflected light at three different locations defined in the formula (1) when the measured object (metallic sensation printed matter) is irradiated from an angle of -45 degrees. It can be determined from the relationship of brightness obtained at three locations. Therefore, the metallic ink can be defined by the metallic index value In1 in the same manner as the metallic pigment for expressing the metallic feeling.

  In addition, the metallic feeling index value In2 represented by the following expression (2) using the lightness at three locations for defining the metallic feeling index value In1, and the metallic feeling index value represented by the following expression (3): In3 or the like may be used as an index of metallic feeling.

  Since any index value expressed by the above formula is determined as a numerical value depending on the reflection angle, the special gloss ink can be defined by these index values.

  In the printing apparatus configured as described above using the special gloss ink such as the metallic ink, the image data to be printed is classified. The printing area performed by the printing apparatus configured as described above is a special glossy area to which special gloss ink is assigned and a color single area to which only color ink is assigned. The former special gloss area is a discharge of special gloss ink by a special gloss printing means. This is a printing region in which color printing that has undergone discharge of a plurality of types of color inks by color printing means is superimposed on a region where special gloss printing is performed. On the other hand, the latter color single area is an area other than the special gloss area, and is a print area on which color color printing is performed only by discharging a plurality of types of color inks by the color printing means. Therefore, when printing on a print medium, the image data to be printed is divided into special glossy area data and color single area data.

  After such data segmentation, different color conversion is performed for each segmented area. That is, when performing color conversion so that the colors represented by the image data to be printed are reproduced using the plurality of types of color inks, first color conversion is performed on the image data in the divided special gloss region, and the color alone The image data in the region is subjected to the second color conversion, and in this first color conversion, the amount of color ink used when reproducing the same color represented by the image data is made smaller than that in the second color conversion. After such color conversion, the color data obtained by the first and second color conversion for each of the divided areas and the special gloss ink are controlled to be discharged from the discharge head of the print head, and the image data Print. As a result, in the special gloss region, the special gloss such as the texture obtained by the special gloss printing on the lower layer side can be ensured by the amount of color ink used in the color printing printed over the special gloss printing. In other words, according to the printing apparatus having the above-described configuration, the amount of color ink with a small amount of color developed with the special gloss such as the texture after securing the special gloss such as the texture obtained through the printing of the special gloss ink. A new printing technique can be provided.

  The printing apparatus described above can be configured as follows. For example, color conversion is performed by referring to different color conversion tables for the first color conversion and the second color conversion, and the color conversion table for the first color conversion is changed to the special glossy ink and the dark color conversion table. The second color conversion table may have a property of performing color conversion to a light color ink instead of the dark color system. In this way, only the dark color ink is used in the first color conversion in the color conversion table itself, so that the amount of ink can be reduced, and color printing can be performed over the special gloss printing in the special gloss area. . As described above, the first color conversion using the color conversion table uses only dark-colored color ink, which is slightly disadvantageous for graininess when viewed with only the color ink, but it is an obstacle to color printing overlaid on the special glossy area. There is no.

  In the color conversion table of the first color conversion, the usage amount of the special glossy ink can be set to the same value at all color conversion grid points. In this way, during special gloss printing in the special gloss area, the discharge amount of the special gloss ink from the special gloss ink discharge head becomes the same, so the load of color conversion processing can be reduced.

  Then, the special gloss printing means is used as the special gloss ink, a texture expression ink containing a pigment that expresses a predetermined texture, or an ink whose optical properties of the ink printed on the medium surface have a reflection angle dependency, Alternatively, a metallic ink containing a pigment that develops a metallic feeling can be ejected. In this way, it is possible to easily provide a color printed matter having a predetermined texture, reflection angle-dependent optical characteristics, or metallic feeling.

[Application 2: Printing method]
A printing method for printing an image using a special gloss printing using a special gloss ink having a special gloss and a color coloring printing using a plurality of types of color inks,
The image data to be printed is divided into special gloss area data to which the special gloss ink is allocated and color single area data to which only the color ink is allocated,
A first color conversion for color-converting the image data in the divided special gloss area in color conversion so as to reproduce the color of the image data to be printed using the plurality of types of color inks; and the color alone The second color conversion for color-converting the image data in the area is executed for each of the divided areas so that the amount of color ink used when reproducing the same color represented by the image data is reduced by the first color conversion. And
The gist is to print the image data through ejection of the color ink of the color obtained by the color conversion and the special gloss ink for each of the divided areas.

  The above-described effects can also be achieved by the printing method having the above configuration.

Hereinafter, embodiments of the present invention will be described in the following order based on examples.
A. Summary of embodiment:
B. Device configuration:
C. Printing process:

A. Summary of embodiment:
FIG. 1 is a schematic configuration diagram of a printing system 10 as an embodiment of the present invention. As shown in the figure, a printing system 10 according to the present embodiment includes a computer 100 as a printing control apparatus, a printer 200 that actually prints an image under the control of the computer 100, and the like. The printing system 10 functions as a printing device in a broad sense as a whole.

  The printer 200 of this embodiment includes, as color inks, cyan ink, magenta ink, and yellow ink, which are dark color inks, light cyan ink, and light magenta ink, which are light color inks, in addition to these. A black ink is provided, and a metallic ink exhibiting a metallic luster due to the metal pigment contained therein is further provided. In this embodiment, the term “color ink” means that black ink is included, and black ink is also treated as a dark color system.

  As the metallic ink, an oil-based ink composition containing a metal pigment, an organic solvent, and a resin was used in this example. About the metal pigment to contain, what was prescribed | regulated as follows is contained. For example, when a tabular grain metal pigment is used and the major axis on the plane of the tabular grain is X, the minor axis is Y, and the thickness is Z, the tabular grain is obtained from the area of the XY plane of the tabular grain. A 50% average particle diameter R50 of the equivalent circle diameter was 0.5 to 3 μm and a condition satisfying the condition of R50 / Z> 5 was employed. In this case, it is possible to use a metal pigment formed of aluminum or an aluminum alloy, or a metal pigment formed by crushing a metal vapor deposition film. In this example, a metal pigment formed from aluminum was employed. The concentration of the metal pigment contained in the metallic ink can also be set to 0.1 to 10.0% by weight, for example, and in this example, 1.5% by weight was used. The color ink is an existing color ink containing a pigment as an organic coloring material that develops the above-described colors.

  A predetermined operating system is installed in the computer 100, and the application program 20 operates under this operating system. A video driver 22 and a printer driver 24 are incorporated in the operating system. The application program 20 inputs image data ORG from the digital camera 120 through the peripheral device interface 108, for example. Then, the application program 20 displays an image represented by the image data ORG on the display 114 via the video driver 22. The application program 20 outputs the image data ORG to the printer 200 via the printer driver 24. Image data ORG input from the digital camera 120 by the application program 20 is data composed of three color components of red (R), green (G), and blue (B).

  The application program 20 according to the present exemplary embodiment includes an area composed of R, G, and B color components (hereinafter referred to as “color coloring area”) and an area printed with metallic ink for an arbitrary area in the image data ORG. (Hereinafter referred to as “metallic area”) can be designated. A part of the metallic area and the color development area are overlapped, and in the overlapped area, a color image is formed on the metallic luster exhibited by the metallic pigment of the metallic ink as a background color. That is, the region where the metallic region and the color development region are superposed in this way is the special gloss region as described in the present application. When the metallic area is designated in this way, the area is designated in advance using tag information or the like attached to the image data. For example, the application program 20 is programmed to set a printing area having a specific graphic shape as the metallic area. Alternatively, the application program 20 can be programmed so that a print area in a specific color is a metallic area.

  Inside the printer driver 24, a color conversion module 42, a halftone module 44, and a print control module 46 are provided.

  In the color conversion module 42, the printer 200 converts the color components R, G, and B of the color development area in the image data ORG in accordance with one of the different color conversion tables LUT / N and LUT / M, which will be described later. The color components that can be expressed are converted into cyan (C), magenta (M), yellow (Y), light cyan (lc), light magenta (lm), and black (K) and metallic (S).

  The halftone module 44 performs a halftone process in which the gradation of the image data color-converted by the color conversion module 42 is represented by dot distribution. In this embodiment, a known systematic dither method is used as the halftone process. As the halftone process, an error diffusion method, a density pattern method, and other halftone techniques can be used in addition to the systematic dither method.

  The print control module 46 rearranges the arrangement of the halftone-processed image data in the order to be transferred to the printer 200, and outputs it as print data to the printer 200. In this case, the well-known microweave method was used. The print control module 46 controls the printer 200 by outputting various commands such as a print start command and a print end command to the printer 200.

  In this embodiment, the print control module 46 includes a metallic dot forming module 47 and a color printing module 48. The metallic dot forming module 47 forms metallic dots of a predetermined size in the metallic area designated by the application program 20. The color printing module 48 forms dots with the color inks of the above-described colors on the halftone-processed image, that is, the image in the color development region.

B. Device configuration:
FIG. 2 is a configuration diagram of a computer 100 as a print control apparatus. The computer 100 is a well-known computer configured by connecting a ROM 104, a RAM 106, and the like with a bus 116 around a CPU 102.

  The computer 100 includes a disk controller 109 for reading data such as the flexible disk 124 and the compact disk 126, a peripheral device interface 108 for exchanging data with peripheral devices, and a video interface 112 for driving the display 114. It is connected. A printer 200 and a hard disk 118 are connected to the peripheral device interface 108. Further, if the digital camera 120 or the color scanner 122 is connected to the peripheral device interface 108, it is possible to perform image processing on an image captured by the digital camera 120 or the color scanner 122. If the network interface card 110 is installed, the computer 100 can be connected to the communication line 300 to obtain data stored in the storage device 310 connected to the communication line. When the computer 100 obtains image data to be printed, the printer driver 24 controls the printer 200 to print the image data.

  Next, the configuration of the printer 200 will be described. FIG. 3 is a block diagram illustrating a schematic configuration of the printer 200. As shown in FIG. 3, the printer 200 is mounted on the carriage 240, a mechanism for transporting the print medium P by the paper feed motor 235, a mechanism for reciprocating the carriage 240 in the axial direction of the platen 236 by the carriage motor 230. And a control circuit 260 that controls the exchange of signals with the paper feed motor 235, the carriage motor 230, the print head 241, and the operation panel 256. Has been.

  The mechanism for reciprocating the carriage 240 in the axial direction of the platen 236 is an endless drive belt between the carriage motor 230 and a slide shaft 233 that is installed in parallel with the platen 236 axis and slidably holds the carriage 240. A pulley 232 that stretches 231, a position detection sensor 234 that detects the origin position of the carriage 240, and the like.

  In the carriage 240, in addition to cyan ink (C), magenta ink (M), yellow ink (Y), and black ink (K) as dark color ink, light cyan as light color ink. A color ink cartridge 243 containing ink (lc) and light magenta ink (lm) is mounted. The carriage 240 is mounted with a metallic ink cartridge 242 that contains metallic ink (S1). A total of seven types of ink ejection heads 244 to 250 corresponding to these colors are formed on the print head 241 below the carriage 240. When these ink cartridges 242 and 243 are mounted on the carriage 240 from above, ink can be supplied from the cartridges to the respective ink ejection heads 244 to 250.

  Here, the print head 241 will be described. FIG. 4 is an explanatory view schematically showing the nozzle arrangement of the ink discharge heads constituting the print head 241. As shown in the drawing, in this embodiment, ink for each color of cyan ink (C), light cyan ink (lc), magenta ink (M), light magenta ink (lm), yellow ink (Y), and black ink (K). Discharge heads 244 to 249 and an ink discharge head 250 for metallic ink (S) are provided. Each ink discharge head includes 10 nozzles arranged on the lower surface of the print head 241 in the sub-scanning direction. Each nozzle is arranged at an interval of 2 dots in the sub-scanning direction. In the drawing, since the lower part indicates the sub-scanning direction, the printing medium P passes through the nozzle shown at the lowermost part during printing. In the drawing, the black-filled nozzles indicate that the metallic ink is discharged from the ink discharge head 250, and the hatched nozzles indicate color inks of the corresponding colors in the ink discharge heads 244 to 249. Indicates that the nozzle is ejected.

  As shown in FIG. 4, in this embodiment, for the ink ejection head 250 of metallic ink, among the 10 nozzles, 5 nozzles that first pass through the print medium P are used during actual printing, The remaining five are not used. In addition, regarding the ink ejection heads 244 to 249 forming the nozzle row of color ink (C, lc, M, lm, Y, K), out of the ten nozzles, the five that pass through the print medium P first. No nozzles are used, and the remaining five are used. Hereinafter, as necessary, nozzles that eject metallic ink are referred to as metallic nozzle groups, and nozzles that eject color ink are referred to as color nozzle groups.

  Piezo elements are incorporated in each nozzle shown in FIG. As is well known, a piezo element is an element that transforms electro-mechanical energy at an extremely high speed because its crystal structure is distorted by application of a voltage. In the present embodiment, by applying a predetermined voltage signal (drive signal) to the piezo element, one side wall of the ink passage in the nozzle is deformed, thereby ejecting an ink droplet from the nozzle. In this embodiment, ink is ejected using a piezo element as described above. However, a method of ejecting ink by generating bubbles in the nozzle may be employed.

  The control circuit 260 of the printer 200 shown in FIG. 3 includes a CPU, a ROM, a RAM, a PIF (peripheral device interface), and the like connected to each other via a bus. The operation of the carriage motor 230 and the paper feed motor 235 is performed. By controlling, the main scanning operation and the sub scanning operation of the carriage 240 are controlled. When print data output from the computer 100 is received via the PIF, a drive signal corresponding to the print data is supplied to the ink ejection heads 244 to 250 in accordance with the movement of the carriage 240 in the main scanning or sub scanning. Thus, these heads can be driven.

  The printer 200 having the above-described hardware configuration drives the carriage motor 230 to reciprocate the ink discharge heads 244 to 250 for each color in the main scanning direction with respect to the print medium P, and a paper feed motor. By driving 235, the print medium P is moved in the sub-scanning direction. The control circuit 260 performs printing by driving the nozzles at an appropriate timing based on the print data in accordance with the movement of the carriage 240 reciprocally (main scanning) or the movement of paper feeding of the printing medium (sub scanning). Ink dots of appropriate colors are formed at appropriate positions on the medium P. In this way, the printer 200 can print a color image on the print medium P and form a color print image area superimposed on the metallic area as will be described later.

  The printer 200 of the present embodiment is described as a so-called inkjet printer that forms ink dots by ejecting ink droplets toward the print medium P. However, the printer that forms dots using any method It does not matter. For example, the present invention can be suitably applied to printers and line printers that form dots by adhering toner powder of each color onto a print medium using static electricity instead of ejecting ink droplets. Is possible.

C. Printing process:
FIG. 5 is a flowchart of the printing process in this embodiment. In this embodiment, the computer 100 discriminates a metallic area using metallic ink, and performs a process for printing with color ink without using the metallic ink for areas other than the metallic area.

  When the printing process is started, the computer 100 first inputs RGB format image data (step S100). When the image data is input, the computer 100 determines a metallic area defined by the application program 20 (step S102). In this determination processing, the computer 100 determines, for example, a graphic area having a specific shape as a metallic area in accordance with a program defined by the application program 20. In addition, the application program 20 can also determine an area printed in a predetermined color as a metallic area including its shape. For example, in the case of a print image including the sun and stars, the sun and stars in the image can be distinguished through image analysis such as shape and color, and the distinction region can be determined as a metallic region. Alternatively, it can be determined as a metallic region by using tag information attached to image data.

  After determining the metallic area, the computer 100 performs color conversion as follows according to the determination result in step S102 in color conversion using the color conversion module 42. By comparing the metallic area determined in step S102 with the position of the pixel that is currently printed (printing target pixel), the current printing target pixel is either a metallic area or a non-metallic area (that is, color ink). Is determined (step S110). If it is determined that the current pixel to be printed is a non-metallic area (color coloring area), the computer 100 uses the CMYKlclm format in which light color ink is added to dark color ink from RGB print image data. The print image data in the format input in step S100 is collated with the existing color conversion table LUT / N for color conversion into the image data of the image (step S112), and the input RGB format image data is converted into the CMYKlclm format. (Step S114).

  On the other hand, if it is determined in step S110 that the current pixel to be printed is a metallic area, the computer 100 converts the color from RGB print image data to CMYKS format image data obtained by adding metallic ink to dark ink. The print image data in the format input in step S100 is checked against the color conversion table LUT / M for conversion (step S116), and the input RGB format image data is converted into CMYKS format image data (step S116). S118).

  Here, the difference between the color conversion table LUT / N used for color conversion of image data belonging to the non-metallic area (color single color development area) and the color conversion table LUT / M used for color conversion of image data belonging to the metallic area will be described. To do. FIG. 6 is an explanatory diagram for explaining the nature of the color conversion table.

  As shown in FIG. 6A, in the existing color conversion table LUT / N used for color conversion of image data belonging to a non-metallic area (color single color development area), as shown in FIG. Corresponding to the gradation, the usage amount is determined while using the dark color ink and the light color ink together. For this reason, input image data in RGB format belonging to the non-metallic area (color coloring area) is reproduced by adding dark color ink (lclm) to dark color ink (CMYK) by collation with the color conversion table LUT / N. Color converted to color. On the other hand, as shown in FIG. 6B, in the color conversion table LUT / M used for the color conversion of the image data belonging to the metallic area, the dark ink is corresponding to the gradation of the input image data in the RGB format. As shown in FIG. 6C, the usage amount of metallic ink is uniformly determined at each color conversion grid point in the color conversion table LUT. For this reason, the input image data in the RGB format belonging to the metallic area is color-converted to a printer reproduction color by dark color ink (CMYK) by collation with the color conversion table LUT / M, and the metallic ink (S). The ink is discharged with the same ink amount.

  Further, the color conversion table LUT / N and the color conversion table LUT / M described above indicate that when the input image data in the RGB format is the same color, the ink amount when the color is converted into a printer reproduction color is metallic. The color conversion table LUT / M that uses ink together is reduced. This point will be described later.

  When the converted image data is obtained in this way, the computer 100 performs halftone processing using the halftone module 44 (step S120) and generates data that can be transferred to the printer 200. When the halftone process is completed, the computer 100 controls the printer 200 through the microweave method performed by the print control module 46, and prints the image data after the halftone process (step S122).

  By the printing process of the present embodiment described above, the printing system 10 in the printing area determined to be the metallic area in step S110, the ink having the metallic nozzle group that first passes through the printing medium as described in FIG. First, the metallic ink is ejected from the nozzles of the nozzle group of the ejection head 250 with the same amount of ink as described above. Thereby, the metallic region is first printed and formed on the surface of the print medium. In addition, in this printed metallic area, the dark color ink is converted into data gradation from the nozzles of the color nozzle group of the ink ejection head corresponding to the dark color ink that has been color-converted using the color conversion table LUT / M. Dispense in an appropriate amount. As a result, the color development region is printed and formed so as to overlap the printed metallic region.

  On the other hand, in the non-metallic area (color-only color development area), the printing system 10 uses the color nozzles of the ink ejection head corresponding to the dark color ink and the light color ink that are color-converted using the color conversion table LUT / N. Dark color ink and light color ink are ejected from the nozzles of the group in amounts corresponding to the data gradation. As a result, a color development region using dark and light color inks is printed and formed.

  For this reason, when the printing result portion obtained by the printing system 10 of the present embodiment is observed from the ink printing surface side, the amount of color ink printed on the metallic region is reduced in the metallic region. It can be ensured that the metallic feeling obtained in the metallic region on the lower layer side is not impaired. This means that according to the printing system 10 of this embodiment, color development with a metallic feeling can be achieved with a small amount of color ink.

  Here, an example will be described in which color development with a metallic feeling can be achieved with a small amount of color ink as described above. FIG. 7 is an explanatory diagram showing the relationship between the dark / light ink composition and the metallic feeling index value In2 when magenta solid printing is performed in the non-metallic region and the metallic region, and FIG. 8 is a cyan solid coating. It is explanatory drawing which shows the relationship between the ink composition of dark color type and light color type, and metallic feeling index value In2 at the time of implementing printing in a non-metallic area | region and a metallic area | region.

  As shown in the figure, in the non-metallic area (color coloring area), when magenta or cyan solid printing is performed without using metallic ink, the color is changed between printing with dark ink and printing with light ink. There was no color difference that could be recognized as different. As described above, the metallic ink is first ejected in a uniform amount (30% in this example) and the metallic area is printed in advance, and then the same dark and light color system as that of the non-metallic area (color single color development area) is formed. Printed with ink. As a result, although the dark color ink is used in a smaller amount than the light color ink, the color color region is printed and formed by discharging the dark color ink over the printed metallic region. The metallic feeling index value In2 was improved. From this, it can be said that color development with a metallic feeling can be achieved with a small amount of color ink as described above. In addition, it can be said that color development with a metallic feeling can be achieved with a small amount of color ink by using dark ink.

  Next, gold printing was similarly examined. FIG. 9 is an explanatory diagram showing a state in which the golden range is defined in the L * a * b * color space when printing in a non-metallic region is performed, and FIG. 10 is defined in the color space of FIG. It is explanatory drawing which shows the relationship between the ink composition of dark color type | system | group and a light color type | system | group at the time of implementing gold printing in a metallic area | region, and a metallic feeling index value In2.

  As shown in FIG. 10, the ink type and the amount of ink used for the dark color ink and the light color ink that can be printed in gold as defined in FIG. 9 are determined, and each of the plurality of dark color inks and the light color inks is determined. The metallic area was printed in gold. In this case, in both printed matter (patch 1 and patch 2) using dark and light color inks, not only in the non-metallic area but also in the metallic area, the color could not be recognized. Nevertheless, as in the case of FIGS. 7 to 8, it was confirmed that color development (gold color development) having a metallic feeling can be achieved with a small amount of color ink by using dark ink. .

  The above results can also be obtained by using a color conversion table LUT / M in which the amount of metallic ink used is the same at the grid points at the time of color conversion as shown in FIG. 6C. That is, since it is sufficient to make the metallic ink discharge amount the same, the load of the conversion process is reduced.

  In addition, the printing system 10 of the present embodiment can achieve color development with a metallic feeling with a small amount of color ink by a so-called inkjet printing method widely used as a printing method.

  As mentioned above, although the Example of this invention was described, this invention is not restricted to above-described embodiment, In the range which does not deviate from the summary, it is possible to implement in various aspects. For example, in the above-described embodiment, printing using metallic ink is performed in the printing system 10 including the computer 100 and the printer 200. In contrast, the printer 200 itself may input image data from a digital camera or various memory cards and perform printing with metallic ink. That is, the CPU in the control circuit 260 of the printer 200 may perform printing using metallic ink by executing processing equivalent to the printing processing in each of the embodiments described above.

  In addition, the metallic glossy ink has been described as an example of the special glossy ink. However, a pigment that expresses a pearly luster after being fixed on the medium surface, for example, a pigment in which a plurality of thin pearly layers such as natural pearls are stacked. In place of metallic ink, pearlescent ink containing lacquer, or lamaque or plain ink containing pigments with minute irregularities to cause irregular reflection after fixing on the medium surface to express so-called lame or plain texture It can also be used.

1 is a schematic configuration diagram of a printing system 10 as an embodiment of the present invention. 1 is a configuration diagram of a computer 100 as a print control apparatus. 2 is a block diagram illustrating a schematic configuration of a printer 200. FIG. FIG. 4 is an explanatory diagram schematically showing the nozzle arrangement of an ink ejection head constituting the print head 241. 6 is a flowchart of print processing in the embodiment. It is explanatory drawing for demonstrating the property of a color conversion table. FIG. 5 is an explanatory diagram illustrating a relationship between a dark color / light color ink composition and a metallic feeling index value In2 when magenta solid printing is performed in a non-metallic region and a metallic region. FIG. 6 is an explanatory diagram illustrating a relationship between a dark color / light color ink composition and a metallic feeling index value In2 when cyan solid color printing is performed in a non-metallic region and a metallic region. It is explanatory drawing which shows a mode that the range of gold | metal | money at the time of performing printing in gold | metal | money in a non-metallic area | region was prescribed | regulated in L * a * b * color space. FIG. 10 is an explanatory diagram illustrating a relationship between a dark color / light color ink composition and a metallic feeling index value In2 when printing in gold color defined in the color space of FIG. 9 is performed in a metallic region.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Printing system 20 ... Application program 22 ... Video driver 24 ... Printer driver 42 ... Color conversion module 44 ... Halftone module 46 ... Print control module 47 ... Metallic dot formation module 48 ... Color printing module 100 ... Computer 102 ... CPU
DESCRIPTION OF SYMBOLS 108 ... Peripheral device interface 109 ... Disk controller 110 ... Network interface card 112 ... Video interface 114 ... Display 116 ... Bus 118 ... Hard disk 120 ... Digital camera 122 ... Color scanner 124 ... Flexible disk 126 ... Compact disk 200 ... Printer 230 ... Carriage motor 231 ... Drive belt 232 ... Pulley 233 ... Slide shaft 234 ... Position detection sensor 235 ... Motor 236 ... Platen 240 ... Carriage 241 ... Print head 242 ... Metallic ink cartridge 243 ... Color ink cartridge 244 to 250 ... Ink ejection head 256 ... Operation panel 260 ... Control circuit 300 ... Communication line 310 ... Storage device LUT / N to LUT / M: Color conversion table P: Print medium

Claims (8)

A printing apparatus that prints an image using a special gloss ink having a special gloss and a plurality of types of color inks,
Special gloss printing means for discharging the special gloss ink and performing special gloss printing;
Color printing means for performing color printing by discharging the plurality of types of color ink for each color; and
A data classifying unit that classifies image data to be printed into data of a special gloss area that is an area to which the special gloss ink is allocated and data of a color single area to which only color ink is allocated;
A first color conversion for color-converting the image data in the divided special gloss area in color conversion so as to reproduce the color of the image data to be printed using the plurality of types of color inks; and the color alone The second color conversion for color-converting the image data in the area is executed for each of the divided areas so that the amount of color ink used when reproducing the same color represented by the image data is reduced by the first color conversion. A color converter to
The color printing unit and the special gloss printing unit are controlled to print the image data through ejection of the color ink obtained by the color conversion and the special gloss ink for each of the divided areas. Bei example and a print control means for performing,
The color conversion unit performs color conversion with reference to different color conversion tables for the first color conversion and the second color conversion, and the color conversion table for the first color conversion includes the special glossy ink and the dark color. A printing apparatus having a property of performing color conversion to a color ink, and wherein the second color conversion table has a property of performing color conversion to a light color ink in addition to the dark color system . 2. The printing apparatus according to claim 1 , wherein the color conversion table of the first color conversion includes all of the usage amount of the special glossy ink as the same value at a color conversion grid point. The special glossy printing means, said a special glossy ink, printing apparatus according to claim 1 or billed to claim 2 ejects texture expression ink containing a pigment to express a given texture. The special light Sawa printing means, said a special glossy ink, printing apparatus according to claim 1 or billed to claim 2 ejects ink optical properties of the ink printed on the medium surface has a reflection angle dependence. A printing method for printing an image using a special gloss printing using a special gloss ink having a special gloss and a color coloring printing using a plurality of types of color inks,
The image data to be printed, the data of the special glossy region is a region for allocating a special glossy ink, as Category Kesuru step (1) to the data of the color only region where only the color inks are allocated,
A first color conversion for color-converting the image data in the divided special gloss area in color conversion so as to reproduce the color of the image data to be printed using the plurality of types of color inks; and the color alone The second color conversion for color-converting the image data in the area is executed for each of the divided areas so that the amount of color ink used when reproducing the same color represented by the image data is reduced by the first color conversion. Step (2) to perform,
A step (3) of printing the image data through ejection of the color ink of the color obtained by the color conversion and the special gloss ink for each of the divided areas ;
In the step (2),
Color conversion is performed by referring to different color conversion tables for the first color conversion and the second color conversion, and the color conversion table for the first color conversion is applied to the special gloss ink and the dark color ink. The second color conversion table is a property that performs color conversion to a light color color ink in addition to the dark color type.
Printing method. The printing method according to claim 5, wherein the special glossy ink is a textured ink containing a pigment that exhibits a predetermined texture. The printing method according to claim 5, wherein the special glossy ink is an ink in which an optical characteristic of ink printed on a medium surface has a reflection angle dependency. The special glossy ink, the claim 6 or a metallic ink containing a pigment expressing feeling metallic printing method according to claim 7.

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