JP2002079695A - Method of color ink jet recording and method of determining rate of color ink - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a white fog in a region of a black ink recorded only by a black ink in the case where a reactive color ink and the black ink are superposed with each other on a region in a black image region adjacent to a color image region in order to eliminate bleeding at a boundary section between the color image region and the black image region. SOLUTION: The region in the black image region adjacent to the color ink recording region 1 is a PCBk(Process Color Bk) region where the reactive color ink 4 representing a relative reactive property to the black ink and the black ink are superposed with each other. The PCBk region is adjacent to the black ink recording region recorded only by the black ink. An ejection amount of the reactive color ink 4 on a region in the PCBk region at the side of the black ink recording region is reduced as the distance to the black ink recording region becomes smaller. As a result, it is possible to prevent bleeding of the ink in the black ink recording region at the side of the PCBk region advancing to the side of the PCBk region.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink-jet recording method for ejecting ink from a recording head for recording, and more particularly to a color ink-jet recording method for recording a color image with high clarity and high density. The present invention relates to a color ink jet recording method using color inks such as magenta (M), cyan (C), or green (G), red (R), and blue (B), and black (Bk) ink.

[0002]

2. Description of the Related Art In an ink jet recording method, as a means for discharging ink as fine droplets from a discharge port and recording characters, figures, etc., low noise, low running cost, and easy downsizing of the apparatus. And it is easy to colorize, and is used in printers, copiers, facsimile machines and the like.

[0003] In order to obtain a high-colored color image without ink bleeding by the conventional color ink jet recording method, it was necessary to use a special paper (coated paper) having an ink absorbing layer. As a result, a method has been put to practical use in which printing aptitude for "plain paper" such as commercially available medium-to-medium paper and general PPC paper, which are used in large quantities in printers and copiers. However,
The biggest issues when recording a color image on “plain paper” are balancing the prevention of ink bleeding between the colors of ink used and the quality of black recording, especially the quality of black character recording. It is to make it.

[0004] In recent years, in order to obtain a color image on a plain paper in which bleeding has been prevented by an ink jet recording method, a quick-drying ink having a high penetration rate to the plain paper has been developed.
Generally, the color ink jet recording method uses three color inks of cyan, magenta, and yellow, and further records a color image using four color inks including black. When the ink having good permeability as described above is used, the recorded image has a high quality without bleeding of the ink between the colors, but has a low density as a whole and also has a low density around the recording image area of each color. The ink has a small amount of feathering along the paper fibers and lacks sharpness.

[0005] Feathering is relatively inconspicuous in a color image area, but is conspicuous in a black image area and deteriorates recording quality. In particular, when the black image is a character, the character is unclear and lacks sharpness, and the quality is poor.

Therefore, in order to obtain high-quality black recording with little feathering and high density, it is necessary to use a black ink used for a black image that has a relatively low penetration rate into plain paper.

Therefore, an ink jet recording apparatus and a recording method using a color ink having a high penetration rate with respect to paper and using an ink having a low penetration rate as a black ink for forming a black image have been proposed. ing. However, in the case of using the ink having a high penetration speed and the ink having a low penetration speed, bleeding of the ink between different colors occurs at an adjacent boundary portion between the recording image areas of black and each color, which significantly reduces the image quality. Lower.

As described above, it is difficult to achieve both the prevention of ink bleeding between black and each color and the reduction of black feathering, and the improvement of color recording quality by achieving both is difficult. This was a problem for color recording.

Japanese Patent Application Laid-Open No. 3-146355 proposes a method of not recording an area along a boundary between black and color. However, this method has a disadvantage that the recorded data changes.

Further, as a measure for preventing border bleeding, in a black area along a border area between black and color, color ink is overprinted on black ink to form a black image, thereby forming a border area between black and color. There is a method of preventing bleeding at the surface. The black formed using the color ink in this manner is referred to as Process Color Bk (hereinafter abbreviated as PCBk) in this specification.

In the method of replacing the black area at the boundary with the color with PCBk, all the black data is converted to Y, M, C P
The simplest method is to substitute CBk data.
The PCBk composed of only Y, M, and C does not unduly seep at the boundary with the color because it is composed of ink having good permeability, but this PCBk is actually different from the Bk ink in hue. It is quite different in terms of that, it will be bordered at the border. So to adjust the color, B
By mixing k inks to some extent, hue shift is also reduced.

Japanese Patent Application Laid-Open No. 7-310037 describes a color ink jet recording method which makes it possible to eliminate "white haze" which is a cause of image deterioration at a boundary between a black image area and a color image area. Have been. FIG. 9 is a diagram for explaining the principle that white haze occurs at the boundary between the black image area and the color image area. When a slow-permeability ink and a fast-permeability ink are used, a new problem arises when the slow-permeability ink and the fast-permeability ink are adjacent to each other, as shown in FIG. A feeling image (this is referred to as “white haze” in this specification) is generated, and this has a considerable effect on the image quality.

This "white haze" is considered to be generated by the following mechanism.
This will be described with reference to FIG.

An ink having good permeability has a property of being hardly wetted by paper, and generally has a high surface tension. Ink with low permeability has the property of easily getting wet with paper,
Generally, a surfactant having a low surface tension, which is added with a surfactant and has improved wettability to paper, is used. As shown in FIG. 10A, when the area recorded with the ink having the surfactant added to improve the wettability and the area recorded with the ink containing no surfactant are adjacent to each other as shown in FIG. The interfacial tension at the adjacent interface is weakened by the agent, and the ink containing no surfactant has a high surface tension, so that the internal cohesive force acts to cause the ink to move into a spherical shape. As shown in FIG. 10), the surfactant also spreads to the area recorded with the ink containing no surfactant, and if it is fixed as it is, as a result, FIG.
It is considered that a region containing a small amount of dye is generated as shown in FIG.

In the recording method described in JP-A-7-310037, in order to eliminate “white haze” at the boundary between the black image area and the color image area, the ink has a surface tension of 40 dyn / cm or less. In this case, the bleeding rate of black ink with respect to plain paper is 2.5 or less, and the bleeding rate of color ink is 2.5 or more and 3.5 or less. Here, the ink bleed rate is a value obtained by dividing the diameter of a dot formed on a recording paper by the diameter of a discharged ink droplet. Specifically, the area of the dot is calculated by ejecting ink droplets onto bond paper (prober bond paper) to form dots, capturing the dots on the obtained recording paper with a CCD camera and performing image processing. Then, it is converted into a perfect circle, and the diameter of the perfect circle is calculated as the diameter A of the dot formed on the recording paper.
And On the other hand, the diameter B of the ejected ink droplet is determined from the relationship between the amount of the ink droplet and the diameter of the sphere (droplet amount = 4/3 · π · (B / 2) ³ ) assuming that the ink droplet is a sphere. The bleed rate (A / B) is calculated from these values.

[0016] Further, in the specifications of Japanese Patent No. 30000516 and Japanese Patent No. 3005166, recording for obtaining a sharp black image with little color mixture regardless of the proximity of different types of inks, for example, color ink and black ink. A method is described. In the recording method of Japanese Patent No. 3001655, the components of PCBk (printing ratio of each color) are controlled in accordance with the ratio of black ink and color ink contacting at the boundary. In the printing method of Japanese Patent No. 300166, the adjacent state of the black area and the color area is detected in a plurality of ranges under the detection conditions with the width of the detection area changed, and the components of PCBk (imprinting of each color) are detected in accordance with the detection result. Ratio).

Further, Japanese Patent No. 3049683 also describes a color ink jet recording method for eliminating ink bleeding between black and each color. In the recording method, the components of PCBk (the ejection ratio of each color) are controlled in accordance with the number of dots (frequency) of the color ink in a predetermined area.

As described above, in the conventional color ink jet recording method, the black area is used for the black area at the boundary between the color ink and the black ink. Thus, bleeding between the color ink and the black ink is suppressed. In addition, as in the recording method described in the above-mentioned Japanese Patent No. 3049683, P is changed according to the Duty of the color ink.
By controlling the components of CBk, black ink and PCB
The difference in color tone at k and the thickening of black characters are suppressed. Furthermore, by changing PCBk stepwise in the black image area, the difference in color tone between black ink and PCBk is suppressed.

Further, Japanese Patent Application Laid-Open No. 6-106841,
JP-A-11-334101, JP-A-11-343
No. 441, U.S. Pat. No. 5,428,383, U.S. Pat. No. 5,488,402, and U.S. Pat.
In each of the symbols, bleeding occurred at the boundary between the image recorded with black ink and the image recorded with color ink (bleed), and occurred at the boundary with the color ink in the black image area. A printing method using at least one reactive color ink exhibiting mutual reactivity with a black ink in order to suppress uneven white image disturbance (white haze) is described. In these documents, in particular, in order to prevent bleeding at the boundary between the image area formed by the black ink and the image area formed by the color ink that is non-reactive with the black ink, the reactive color ink is applied to the black ink image area. A recording method (underprinting method) for performing recording is disclosed.
As the reactive color ink exhibiting mutual reactivity with the black ink, specifically, a color ink obtained by adding a precipitant composed of at least one polyvalent metal salt composed of a polyvalent metal cation to the color ink is used. Have been. As a result, when the black ink and the reactive color ink are superimposed on the recording medium, the black ink reacts with the reactive color ink, thereby promoting the aggregation of the black ink and fixing the black ink on the recording medium. Be transformed into Therefore, by overlapping the black ink and the reactive color ink in an area adjacent to the color ink image area in the black image area, the boundary between the image printed with the black ink and the image printed with the color ink is obtained. Occurrence of bleeding at the portion and occurrence of white haze at the boundary with the color ink in the black image area are suppressed.

[0020]

However, as described above, the black ink and the reactive ink are overlapped in a region adjacent to the color ink image region in the black image region, so that the black image region and the color ink image region are overlapped. Bleeding at the boundary of the black image area and white haze in the area adjacent to the color ink image area in the black image area can be suppressed. If the black ink recording area is adjacent to the recorded black ink recording area, there is a problem that uneven image distortion (white haze) having a blurred white appearance may occur in the black ink recording area. This is because the permeability of the ink in the superimposed area of the black ink and the reactive color ink is higher than the permeability of the black ink only, and is adjacent to the superimposed area in the black ink recording area of only the black ink. It is considered that this is caused by the ink in the overlapped area being drawn into the overlapping area.

FIG. 11 is a diagram for explaining the occurrence of white haze in the black ink recording area adjacent to the overlapping area of the black ink and the reactive color ink. FIG.
1 (a) is a color image area on a recording medium, PCB
FIG. 11B is a diagram schematically illustrating the arrangement of the k region and the black ink region. FIG. 11B is a cross-sectional view of the recording medium in the region illustrated in FIG.

As shown in FIG. 11A, a color image area 4 in which a color image is recorded using color inks.
1 and a black ink recording area 45 where an image of only black ink is recorded, in order to suppress ink bleeding at the boundary between the black ink recording area 45 and the color ink recording area, A PCBk area 43 is provided. PCBk
In the region 43, a reactive color ink having mutual reactivity with the black ink is superimposed on the black ink. The black ink and the reactive color ink react in the PCBk area 43 to promote the aggregation of the black ink, and the color image area 41 and the P
The bleeding of the ink at the boundary of the CBk region 43 is suppressed.

In such a case, as shown in FIG. 11B, the color image area 41 and the PCBk area 43
Are penetrated into the recording medium by being driven by the color ink. Therefore, the respective inks of the color image area 41 and the PCBk area 43 penetrate deeper into the recording medium than the ink of the black ink recording area 45, and on the surface layer of the recording medium, the color image area 41 and the PCBk area A portion corresponding to each of 43 is a permeation region 46.

In the permeation area 46, water, a solvent, a surfactant and the like constituting the ink have permeated into the recording medium. As described above, the ink in the PCBk area 43 has a higher permeability than the black ink because the color ink is injected, and accordingly, the black ink in the black ink recording area 45 has a high permeability, That is, the penetration area 46
11B, it is easy to penetrate into the recording medium in the direction of arrow A in FIG. Here, the PC of the black ink recording area 45
When the black ink in the portion on the Bk region 43 side penetrates into the permeation region 46 side, the black ink in that portion in the black ink recording region 45 escapes, and the black ink recording region 45 as shown in FIG. White haze occurs. That is, the area on the PCBk area 43 side of the black ink recording area 45 becomes the white haze occurrence area 45a where white haze occurs.
As a result, the image is disturbed in the black image area, and the quality of the recorded image on the recording medium is deteriorated.

FIG. 12 is a diagram for explaining the change in the influence of the PCBk area and the change in bleed on the black ink recording area recorded only with black ink when the amount of color ink applied in the PCBk area is changed. FIG. In order to experimentally examine the occurrence of white haze and the occurrence of bleed when the proportion of the color ink in the PCBk area, that is, the composition of the ink in the PCBk area, was changed, the recorded image shown in FIG. Recording was performed on plain paper (NSK, NDK) as a recording medium. FIG.
In the recorded image shown in (a), seven rectangular image patterns are arranged in a line at a predetermined pitch. In each of the image patterns, a rectangular area at the center is a color image area 51, and an area around which the color ink is superimposed on the black ink is surrounded by a rectangular PCB.
A k region 53 is provided. The color image area 51 is P
It is surrounded by the CBk area 53, and the entire edge of the color image area 51 is adjacent to the PCBk area 53.
A black ink recording area 55 having a rectangular outer shape, which is recorded only with black ink, is provided around the PCBk area 53. The PCBk area 53 is surrounded by the black ink recording area 55, and the entire edge of the PCBk area 53 is adjacent to the black ink recording area 55.

FIG. 12B is a diagram showing the amount of color ink applied to each of the seven image patterns shown in FIG. FIG.
Numerals 1 to 7 on the horizontal axis shown in (b) indicate the order from the left of the seven image patterns shown in FIG. 12 (a). As shown in FIG. 12B, in the PCBk area 53 of the image pattern arranged on the leftmost side in FIG.
The larger the amount of the color ink applied, the larger the number of the ink droplets.

FIG. 13 shows the PCBk area 5 shown in FIG.
FIG. 3 is a diagram for describing a configuration of ink in No. 3; Each of FIG. 13A to FIG.
Four rows and four rows (4 ×
FIG. 4 is a diagram illustrating an example of a dot pattern of each ink at the dot matrix of 4). 13A illustrates a dot pattern of yellow ink, FIG. 13B illustrates a dot pattern of magenta ink, FIG. 13C illustrates a dot pattern of cyan ink, and FIG. Is a diagram showing a dot pattern of black ink.

For example, as shown in FIG.
For a dot matrix of × 4, two dots of the yellow ink 31 are ejected at positions separated from each other, and for a similar dot matrix, magenta dots are formed at positions separated from each other as shown in FIG. Four dots of ink 32 are shot. Then, as shown in FIG. 13C, eight dots of the cyan ink 33 are printed at positions that are not adjacent to each other in the vertical and horizontal directions for the same dot matrix, and the same dot matrix is formed. 13D, dots of the black ink 34 are printed on all the areas as shown in FIG. Thus, FIG.
13A to 13D, the dot patterns of the inks of the respective colors are superimposed to form the PCBk area 53.
Is formed in black. Actually, in each image pattern shown in FIG.
Was changed corresponding to the relationship described based on FIG. 12B.

FIG. 14 is a diagram showing the structure of ink in the color image area 51 shown in FIG. 12, and FIG.
FIG. 13 is a diagram illustrating a configuration of ink in a black ink recording area 55 illustrated in FIG. 12. As shown in FIG. 14, in the color image area 51, a magenta color image was formed by ejecting magenta ink 62 in all areas of the dot pattern. As shown in FIG. 15, in the black ink recording area 55,
A black image was formed by ejecting only the black ink 64 into all areas of the dot pattern.

In this case, as shown in FIG. 12A, in the first and second image patterns from the left, white haze does not occur in the black ink recording area 55, but the third, fourth, and fourth image patterns from the left. In each of the fifth, sixth, and seventh image patterns, the PC in the black ink recording area 55
White haze 57 occurs in an area adjacent to the Bk area 53. The area where the white haze 57 occurs is larger in the right image pattern.

In the first, second, third, fourth, and fifth image patterns from the left in FIG. 12A, a color image area 51 and a PCBk area 53 are provided.
Bleed (bleeding) 56 occurs at the boundary with
In the sixth and seventh image patterns from the left, no bleed 56 occurred at the boundary between the color image area 51 and the PCBk area 53. The area where the white haze 56 occurs becomes larger as the left image pattern is formed. Therefore, in each of the seven image patterns shown in FIG. 12A, at least one of white haze and bleed occurs.

In such an experiment, the color image area 5
1 and the black ink recording area 55, simply providing the PCBk area 53 with a uniform amount of color ink applied thereto,
The white haze of the black ink recording area 55 and the color image area 51
It was found that both bleeding at the boundary between the substrate and the PCBk region 53 could not be suppressed. The configuration of the PCBk area 53 is as follows: Black (black) = 255/25 as a ratio of each color in 256 dots (0 to 255) of 16 × 16.
5, color ink Cyan (cyan) = 8/255, Mag
When enta (magenta) = 4/255 and Yellow (yellow) = 2/255 or less, it was confirmed that white haze did not occur in the black ink recording area around the PCBk area.

It is an object of the present invention to reduce the occurrence of blur at the boundary between the color image area and the black image area and the white haze in the black image area adjacent to the color image area. When the black ink and the reactive color ink are overlapped in the area adjacent to the color image area in the area, the area where the black ink and the reactive color ink are overlapped is black ink recording where only the black ink is recorded. An object of the present invention is to provide a color ink jet recording method capable of suppressing occurrence of white haze in a black ink recording area due to being adjacent to an area.

Another object of the present invention is to determine a ratio of a reactive color ink in a region where a black ink and a reactive color ink are overlapped in order to realize the above-described color ink jet recording method. Is possible,
An object of the present invention is to provide a method for determining the ratio of color ink.

[0035]

In order to achieve the above-mentioned object, the present invention uses a color ink and a black ink having a different permeability from the color ink to a recording medium, and uses the color ink in accordance with recording data. When recording a desired color image on a recording medium, a color ink recording area recorded using the color ink on the recording medium and a black ink recording area recorded only with the black ink. In order to prevent bleeding at the boundary portion, at least one of the black image areas constituting the black image on the recording medium adjacent to the color ink recording area in at least one area showing mutual reactivity with the black ink. In a color inkjet recording method in which a reactive color ink is superimposed on the black ink, the black ink and the reactive color ink overlap on the recording medium. Of the areas to be combined, at least a portion on the black ink recording area side in an area in contact with the black ink recording area recorded only with the black ink, the ratio of the reactive color ink to the black ink, Corresponding to the distance to the black ink recording area, the value is decreased in the direction from the color ink recording area to the black ink recording area.

According to the above invention, in order to prevent bleeding at the boundary between the black ink recording area where only the black ink is recorded on the recording medium and the color ink recording area where the color ink is recorded using the color ink. In the region where the black ink and the reactive color ink are superimposed on the recording medium, the ratio of the reactive color ink to the black ink is determined at least in the region in contact with the black ink recording region on the black ink recording region side. The distance between the black ink recording area and the black ink recording area is reduced in the direction from the color ink recording area to the black ink recording area. The black ink is prevented from being drawn into the color ink recording area. As a result, the occurrence of white haze in the black ink recording area is suppressed, and as a result, the black image is prevented from being disturbed, and a high-quality black image can be recorded. In addition, at least one reactive color ink exhibiting mutual reactivity with the black ink is superimposed on the black ink in at least an area adjacent to the color ink recording area in a black image area forming a black image on the recording medium. Therefore, the occurrence of bleeding at the boundary between the image recorded with black ink and the image recorded with color ink is prevented. Furthermore, since the black ink and the reactive color ink are superimposed on a portion of the black image region on the side of the color ink recording region, the occurrence of white haze at that portion is suppressed. as a result,
Disturbance of the image at the boundary between the black image and the color image is prevented, and both the recording of a high-quality black image and the recording of a high-quality color image are realized.

Further, according to the present invention, when a desired color image is recorded on a recording medium in accordance with recording data using a color ink and a black ink having a different permeability from the recording medium. In order to prevent bleeding at the boundary between the color ink recording area recorded using the color ink and the black ink recording area recorded only with the black ink on the recording medium, A color in which at least one reactive color ink exhibiting mutual reactivity with the black ink is superimposed on the black ink in at least an area adjacent to the color ink recording area in a black image area forming a black image on a recording medium. In the ink jet recording method, the color ink is provided in an area where the black ink and the reactive color ink are overlapped on the recording medium. The proportion of the reactive color ink in the area in contact with the recording area, to relatively greater than the proportion of the reactive color ink in the area in contact with the black ink recording region.

According to the above-described invention, in order to prevent bleeding at the boundary between the black ink recording area where only the black ink is recorded on the recording medium and the color ink recording area where the color ink is recorded using the color ink. In the region where the black ink and the reactive color ink overlap on the recording medium, the ratio of the reactive color ink in the region in contact with the color ink recording region is determined by the ratio of the reactive color ink in the region in contact with the black ink recording region. By making it relatively larger than that, it is possible to suppress the black ink in the black ink recording area from being drawn into the color ink recording area due to the difference in permeability between the color ink and the black ink. As a result, the occurrence of white haze in the black ink recording area is suppressed, and as a result, the black image is prevented from being disturbed, and a high-quality black image can be recorded. In addition, at least one reactive color ink exhibiting mutual reactivity with the black ink is superimposed on the black ink in at least an area adjacent to the color ink recording area in a black image area forming a black image on the recording medium. Therefore, the occurrence of bleeding at the boundary between the image recorded with black ink and the image recorded with color ink is prevented. Furthermore, since the black ink and the reactive color ink are superimposed on a portion of the black image region on the side of the color ink recording region, the occurrence of white haze at that portion is suppressed. As a result, the image is prevented from being disturbed at the boundary between the black image and the color image, and both the printing of a high-quality black image and the printing of a high-quality color image are realized.

In the area where the black ink and the reactive color ink overlap on the recording medium,
It is preferable to change the ratio of the reactive color ink continuously or stepwise.

Further, according to the present invention, a desired color image is recorded on a recording medium in accordance with recording data by using a color ink and a black ink having different permeability to the recording medium. A color ink recording area recorded on the recording medium using the color ink;
An area adjacent to at least the color ink recording area in a black image area forming a black image on the recording medium, in order to prevent bleeding at a boundary with a black ink recording area recorded only with the black ink; In a color inkjet recording method in which at least one reactive color ink exhibiting mutual reactivity with the black ink is superimposed on the black ink, a first area adjacent to the color ink recording area in the black image area In superimposing the black ink and the reactive color ink, and,
In a second area of the black image area interposed between the first area and the black ink recording area, the ratio of the reactive color ink to the black ink is set to the first area.
The black ink and the reactive color ink are overlapped with each other to make the area smaller than the area.

In the above invention, the black ink is used to prevent bleeding at the boundary between the color ink recording area recorded using color ink on the recording medium and the black ink recording area recorded using only black ink. In the first area adjacent to the color ink recording area in the image area, the black ink and the reactive color ink are overlapped and sandwiched between the first area in the black image area and the black ink recording area. In the second area, the ratio of the reactive color ink to the black ink is smaller than that in the first area, and the black ink and the reactive color ink are overlapped. The permeability of the ink between the region and the region changes stepwise. As a result, occurrence of white haze in the first and second areas in the black image area and the black ink recording area is suppressed, and as a result, disturbance of the black image is prevented and a high-quality black image can be recorded. Becomes Also,
In a region adjacent to at least the color ink recording region in the black image region constituting a black image on the recording medium,
Since at least one reactive color ink that shows reactivity with the black ink is superimposed on the black ink, bleeding occurs at the boundary between the image recorded with the black ink and the image recorded with the color ink. Has been prevented. As a result, the image is prevented from being disturbed at the boundary between the black image and the color image, and both the printing of a high-quality black image and the printing of a high-quality color image are realized.

Further, the present invention uses a color ink and a black ink having different permeability to the recording medium, and uses the color ink to record a desired color image on the recording medium in accordance with the recording data. In the inkjet recording method, on a recording medium, in order to prevent bleeding at a boundary between a color ink recording area recorded using the color ink and a black ink recording area recorded only with the black ink, At least one reactive color ink exhibiting mutual reactivity with the black ink is superimposed on the black ink in at least an area adjacent to the color ink recording area in a black image area forming a black image on the recording medium. At the time of matching, the reactive color ink in the overlapping area of the black ink and the reactive color ink on the recording medium A method for determining a combination, a method of determining a ratio of a color ink, wherein a step of recording a recording image on a recording medium by changing a ratio of the reactive color ink in the overlapping area, and the recording image recorded Determining the image state of at least an area adjacent to the superimposition area in the black ink recording area recorded only with the black ink, and the reactive color ink in the superimposition area based on the determination result. Determining the distribution of the ratios.

Further, in the step of judging the image state of the area adjacent to the overlapping area in the black ink recording area, the density of the black ink in the adjacent area is visually determined, and the density of the black ink in the overlapping area is determined. In the step of determining the distribution of the ratio of the reactive color ink, a condition that the density of the black ink in the adjacent area exceeds a predetermined density is set in the area adjacent to the black ink recording area in the overlapping area. It is preferable to use image data to be recorded.

In the invention as described above, the recording image is recorded on the recording medium by changing the ratio of the reactive color ink in the overlapping area of the black ink and the reactive color ink on the recording medium, and the recording is performed. After determining the image state of at least the area adjacent to the superimposition area in the black ink recording area recorded only with black ink, the reactive color ink in the superimposition area is determined based on the determination result. By determining the distribution of the ratio, it is possible to obtain an optimum printing condition that can suppress the occurrence of white haze in the black ink printing area as described above. Therefore, it is possible to prevent the image from being disturbed at the boundary between the black image and the color image, and to obtain an optimum recording condition capable of realizing both high-quality black image recording and high-quality color image recording. be able to.

[0045]

Next, embodiments of the present invention will be described with reference to the drawings.

(First Embodiment) FIG. 1 is a perspective view and an exploded perspective view showing a head cartridge suitable for an ink jet recording apparatus to which the color ink jet recording method of the present invention is applied or applied. FIG. 2 is an exploded perspective view showing the configuration of the recording head shown in FIG. 1, and FIG. 3 is a perspective view showing the bottom side of the recording head. Hereinafter, each component will be described with reference to these drawings.

An ink jet recording apparatus to which the color ink jet recording method of the present embodiment is applied includes a recording head (ink jet recording head) H10 shown in FIG.
01 is mounted. The recording head H1001 is shown in FIG.
As can be seen from the perspective views of FIG. 1A and FIG. 1B, the recording head cartridge H1000 is a constituent element of the recording head cartridge H1000. The recording head cartridge H1000 is provided detachably on the recording head H1001 and the recording head H1001. Ink tank H1900 (H1901, H19
02, H1903, H1904). The recording head H1001 has an ink tank H1900.
(Recording liquid) supplied from the printer is discharged from the discharge port in accordance with the recording information.

This recording head cartridge H1000
Is fixedly supported by positioning means and electrical contacts of a carriage (not shown) mounted on the ink jet recording apparatus main body, and is detachable from the carriage. The ink tank H1901 is for black (black) ink, the ink tank H1902 is for cyan ink, the ink tank H1903 is for magenta ink, and the ink tank H1904 is for yellow ink. Thus, the ink tanks H1901, H1902,
Each of H1903 and H1904 is a recording head H10.
Since the ink tank is detachable with respect to the ink tank 01 and each ink tank is replaceable, the running cost of printing in the ink jet recording apparatus is reduced.

The recording head H1001 employs a bubble jet (registered trademark) system in which recording is performed using an electrothermal transducer (recording element) that generates thermal energy for causing film boiling in ink in response to an electric signal. Is a side shooter type recording head.

As shown in the exploded perspective view of FIG. 2, the recording head H1001 comprises a recording element unit H1002, an ink supply unit H1003, and a tank holder H2000. As shown in FIG. 2, the print head H1001 includes a print element unit H1002 and a screw H2.
400, coupled to the ink supply unit H1003,
Further, it is completed by coupling with the tank holder H2000. The completed drawing is shown in FIG. When coupling the recording element unit H1002 to the ink supply unit H1003, a joint seal member H2300 is used to connect the ink communication port of the recording element unit H1002 and the ink communication port of the ink supply unit H1003 so that ink does not leak. Are fixed with screws H2400 so as to press-fit each member.

The electric contact substrate H2200 of the recording element unit H1002 is connected to the ink supply unit H10.
03, the terminal positioning pins (two places) of the ink supply unit H1003 and the electric contact board H220
It is positioned and fixed by the 0 terminal positioning holes (2 places). As a fixing method, for example, the fixing is performed by caulking a terminal connecting pin provided in the ink supply unit H1003, but the fixing may be performed using other fixing means. Further, the coupling hole and the coupling portion of the ink supply unit H1003 with the tank holder are fitted and coupled to the tank holder H2000, thereby completing the recording head H1001.

As shown in FIGS. 2 and 3, the recording element unit H1002 has a discharge port array H1 for discharging black ink supplied from the ink tank H1901.
011, an ejection port array H1012 for ejecting the cyan ink supplied from the ink tank H1902, the ink tank H
An ejection port array H1013 for ejecting magenta ink supplied from 1903, and an ejection port array H1014 for ejecting yellow ink supplied from the ink tank H1904.
Is provided. Discharge port row H1011, H1012
H1013 and H1014 are arranged in that order in parallel with each other.

FIGS. 1A and 1B show the recording head H100 constituting the recording head cartridge H1000.
1 and ink tanks H1901, H1902, H190
FIG. 3 is a diagram for explaining mounting of H1904, and inks of corresponding colors are stored in the ink tanks H1901, H1902, H1903, and H1904 as described above. In each ink tank, an ink communication port for supplying the ink in the ink tank to the recording head H1001 is formed. For example, the ink tank 19
01H is attached to the print head H1001, the ink communication port of the ink tank H1901 is connected to the print head H1001.
1 is pressed against the filter provided at the joint,
Black ink in the ink tank H1901 is supplied from the ink communication port to each discharge port of the discharge port array H1011 via the ink flow path of the recording head H1001.

Then, the ink is supplied to the bubbling chamber having the electrothermal conversion element and the discharge port, and the ink is discharged toward the recording paper as the recording medium by the thermal energy given to the electrothermal conversion element.

The cyan, magenta, and yellow color inks stored in the respective ink tanks H1902 to H1904 have a penetrating speed into the recording paper so that the ink does not bleed at the boundary between colors when a color image is formed. The fastest one is used. On the other hand, the black ink stored in the ink tank H1901 is set in the above-described manner so that the black image has high density and high quality with little feathering.
A type of ink that has a relatively low permeation rate into recording paper as compared with the type of color ink is used.

In the color ink jet recording method according to the present embodiment, a reactive color ink having mutual reactivity with the black ink is used as at least one of the yellow, magenta and cyan color inks. Specifically, a reactive color ink to which a metal ion such as Mg ²⁺ was added was used so that the reactive color ink reacted with the black ink so as to promote the aggregation of the black ink. When a metal ion is added to the color ink, a precipitant composed of at least one polyvalent metal salt composed of a polyvalent metal cation may be added. Metal ions may be added to all of the yellow, magenta, and cyan color inks, and all of these color inks may be made reactive color inks.

In the black image area constituting the black image on the recording medium, at least in the area adjacent to the color ink recording area, the reactive color ink and the black ink are overlapped, and the inks are overlapped. Was reacted. This promotes aggregation of the black ink at the boundary between the black image area and the color ink recording area, and the black image area and the color image on the recording medium due to the difference in permeability between the color ink and the black ink to the recording medium. Bleeding of ink (bleed) at the boundary of the ink recording area is suppressed. As described above, an area where the black ink and the color ink are overlapped in the black image area forming the black image is hereinafter referred to as PCB
k (Process Color Bk) area.

The PCBk area may be adjacent to the black ink recording area recorded only with black ink, depending on the arrangement of the black image and the color image on the recording medium. When they are adjacent to each other, an image having a feeling of white blur (also referred to as “white haze” in this specification) may be generated in a portion of the black ink recording area adjacent to the PCBk area. As described above, in order to suppress “white haze” in a portion adjacent to the PCBk area in the black ink recording area, in the color inkjet recording method of the present embodiment, as described later, at least the black ink recording area side in the PCBk area is used. In the portion, the ratio of the reactive color ink to the black ink is gradually decreased from the substantially central portion of the PCBk area toward the black ink recording area. Alternatively, in the black ink recording area conventionally recorded only with black ink, the area adjacent to the PCBk area is changed to the reactive color ink at a smaller ratio than the reactive ink in the PCBk area. This is a new PCBk area where ink is superimposed.

FIG. 4 is a plan view for explaining the color ink jet recording method according to the first embodiment of the present invention. FIG. 4A shows an example of a reactive color ink ejection pattern in a boundary area between a PCBk area adjacent to a color ink recording area on a recording sheet and a black ink recording area near the PCBk area. FIG. In the PCBk area shown in FIG. 4, the dots of the reactive color ink are schematically shown in a circular shape in order to easily understand the amount of the reactive color ink applied to the black ink. In the present embodiment, plain paper (NSK, ND) is used as a recording paper as a recording medium for image recording.
K) was used.

As shown in FIG. 4A, a color ink recording area 1 recorded on recording paper using color inks
Is adjacent to a first PCBk (Process Color Bk) area 2a. The first PCBk area 2a is adjacent to the second PCBk area 2b. This first PCBk
Each of the region 2a and the second PCBk region 2b
This is a black image area formed using black ink and color ink. In the first PCBk area 2a and the second PCBk area 2b, although not shown in FIG. 4, almost all of those areas are printed with black ink. Reactive color ink 4 having mutual reactivity with the black ink is superimposed on the black ink in each of first PCBk region 2a and second PCBk region 2b. As the reactive color ink 4, specifically, in the color ink,
A material to which a precipitant comprising at least one polyvalent metal salt comprising a polyvalent metal cation is added is used.

When the black ink and the reactive color ink 4 are superimposed on the recording paper, the black ink reacts with the reactive color ink 4 to promote the aggregation of the black ink. Be fixed. As a result, bleeding occurs at the boundary between the image printed with black ink and the image printed with color ink, that is, the first PCB
The occurrence of bleeding at the boundary between the k region 2a and the color ink recording region 1 is prevented. Further, since the black ink and the reactive color ink 4 are superimposed on each other in the first PCBk area 2a, the white haze at the portion adjacent to the color ink in the black image area, that is, the first PCBk area 2a , The occurrence of white haze in the portion on the color ink recording area 1 side is suppressed. This is the first PCBk region 2
a, the magnitude of the difference in permeability between the ink superposed in the first PCBk area 2a and the color ink recording area 1 is determined by the superposition of the black ink and the reactive color ink 4. This is because it became smaller than the difference in permeability.

The second PCBk area 2b has a black ink recording area 3 which is an area recorded only with black ink.
a is adjacent. The second PCBk area 2b is a relatively narrow area with respect to the black ink recording area 3a, and the second PCBk area 2b is located between the first PCBk area 2a and the black ink recording area 3a.
The second PCBk region 2b is provided so as to sandwich the PCBk region 2b. This second PCBk area 2b
Then, the ratio of the reactive color ink 4 to the black ink,
Here, the ratio of the reactive color ink 4 itself is the first P
It gradually decreases as it approaches the boundary with the black ink recording area 3a from the boundary with the CBk area 2a. Therefore, among the areas where the black ink and the reactive color ink 4 are superimposed on the recording paper, the black ink recording area 3
In the area adjacent to the black ink recording area 3a in the area in contact with a, the ratio of the reactive color ink 4 to the black ink gradually decreases as the distance from the black ink recording area 3a decreases.

The second PCBk area 2b is the first PCBk area 2b.
Is provided between the PCBk area 2a and the black ink recording area 3a, so that the area in contact with the color ink recording area 1 in the entire PCBk area including the first PCBk area 2a and the second PCBk area 2b. Is relatively larger than the ratio of the reactive color ink 4 in the area in contact with the black ink recording area 3a. As a result, the occurrence of white haze in the portion of the black ink recording area 3a on the first PCBk area 2a side is suppressed. This is the first PCBk area 2a
The boundary between the black ink recording area 3a and the second P
In the CBk region 2b, the permeability of the ink in which the black ink and the reactive color ink 4 are superimposed gradually changes according to the ratio of the reactive color ink 4, and the permeability of the ink on the recording paper becomes extremely high. This is because there is no significant change in the area. This suppresses the black ink in the portion of the black ink recording area 3a on the second PCBk area 2b side from being drawn into the second PCBk area 2b.

Accordingly, the occurrence of bleeding at the boundary between the color ink recording area 1 and the first PCBk area 2a and the occurrence of white haze in the first PCBk area 2a are prevented, and the black ink is further prevented. The occurrence of white haze in the recording area 3a is suppressed. As a result, it is possible to prevent the image from being disturbed at the boundary between the black image and the color image, and to realize both the printing of the high-quality black image and the printing of the high-quality color image.

FIG. 4B is a plan view for explaining a modification of the color ink jet recording method of the present embodiment. As shown in FIG. 4B, in the PCBk area 2c adjacent to the color ink recording area 1, the ratio of the reactive color ink 4 to the black ink may be changed. In this modification, a black ink recording area 3b in which a black image is recorded using only black ink is adjacent to the PCBk area 2c. Then, the proportion of the reactive color ink 4 in the PCBk area 2c gradually decreases as approaching from the center of the PCBk area 2c to the black ink recording area 3b. Accordingly, in the portion of the PCB k area 2c where the black ink and the reactive color ink 4 are superimposed on the recording paper, the ratio of the reactive color ink 4 to the black ink in the black ink recording area 3b side is reduced. Area 3
It gradually decreases as the distance to b decreases. Thereby, the PCB in the black ink recording area 3b is
The black ink in the portion on the k-region 2c side is the PCB k-region 2c
To the black ink recording area 3
The occurrence of white haze at the portion on the PCBk region 2c side in b is suppressed.

As described above, in the black image area, the area adjacent to the color ink recording area is set as the PCBk area for recording by superposing the reactive color ink on the black ink, and only the black ink is set in the PCBk area. By gradually decreasing the ratio of the reactive color ink 4 in the area adjacent to the black ink recording area, the occurrence of bleeding at the boundary between the color ink recording area 1 and the PCBk area 2c, the PCBk area 2c and the black ink The occurrence of white haze in the recording area 3b is suppressed. As a result, as described above, the image is prevented from being disturbed at the boundary between the black image and the color image, and both the printing of a high-quality black image and the printing of a high-quality color image are realized.

As described above, in the color ink jet recording method of the present embodiment, the ratio of the reactive color ink 4 in the PCBk area is gradually decreased as approaching the black ink recording area of only black ink. The change in the ratio of the reactive color ink 4 may be a step change (gradation) even if it is a continuous change as long as white haze can be suppressed in a portion of the black ink recording area on the PCBk area side. There may be.

FIG. 5 is a diagram for explaining a change in the ratio of the reactive color ink in the PCBk region by the color ink jet recording method of this embodiment. FIG.
(A) is a PC for a color image area on recording paper.
FIG. 3 is a diagram schematically illustrating an arrangement of a Bk area and a black ink recording area. FIG. 5B shows the PCBk shown in FIG.
FIG. 5C is a graph illustrating an example of a change in the amount of color ink applied to the area, and FIG. 5C is a graph illustrating another example of changing the amount of the color ink applied to the area.

As shown in FIG. 5A, a color image area 11 forming a color image on a recording sheet and a black image area 12 forming a black image on the recording sheet are adjacent to each other. The black image area 12 has a black ink recording area 15 where only black ink is recorded and a black ink recording area 15 for suppressing ink bleeding at a boundary between the black image area 12 and the color image area 11. Area 15 and color image area 11
And a PCBk area 43 provided between the two.

In the PCBk region 13, as shown by the solid line in the graph of FIG. 5B, the amount of the reactive color ink, that is, the ratio of the reactive color ink, is determined from the color image region 11 side. It may be reduced in three steps toward the black ink recording area 15 side.
Alternatively, the ejection amount of the reactive color ink in the PCBk area 13 is changed from the color image area 11 side to the black ink recording area 15 side as indicated by a one-dot chain line or a two-dot chain line in the graph of FIG. It may be reduced continuously. Therefore, the proportion of the reactive color ink in the PCBk area 13 only needs to decrease in the direction from the color image area 11 to the black ink recording area 15 corresponding to the distance from the black ink recording area 15.

Therefore, regarding the change in the ratio of the reactive color ink in the PCBk area 13, the white haze in the portion on the PCBk area 13 side in the black ink recording area 15 can be suppressed, and Any type may be used as long as bleeding of ink at the boundary with the color image area 11 can be suppressed. In order to suppress such white haze and bleeding, as shown in FIG. 5A, in the PCBk area 13, the ratio of the reactive color ink in the adjacent area 13a in contact with the black ink recording area is set as follows. Adjacent area 13 in contact with color image area 11
What is necessary is just to make it relatively larger than the ratio of the reactive color ink in b.

Therefore, in the area between the adjacent areas 13a and 13b in the PCBk area 13, the ratio of the reactive color ink may be changed in any manner. For example, as shown in FIG. 5C, in the PCBk area 13, the ratio of the reactive color ink in the adjacent area 13 a that is in contact with the black ink recording area 15 is determined by the color image area 11.
The ratio of the reactive color ink is relatively larger than the ratio of the reactive color ink in the adjacent region 13b in contact with the region, and the ratio of the reactive color ink is sharply locally increased in the region between the adjacent regions 13a and 13b in the PCBk region 13. Or a sharp decrease locally.

When the proportion of the reactive color ink in the PCBk area is to be changed stepwise, it may be changed at least one step (one step). Therefore, in that case, as described later in the second embodiment, a first PCBk area adjacent to the color ink recording area,
The first PC is located between the first PC and the black ink recording area containing only black ink.
A second PCBk area may be provided in which the reactive color ink is superimposed on the black ink at a rate smaller than the rate of the reactive color ink in the Bk area. This also
It is possible to suppress the occurrence of white haze in the area on the PCBk area side in the black ink recording area using only black ink.

Furthermore, in order to realize the color ink jet recording method of the present invention, the distribution of the ratio of the reactive color ink in the PCBk region, that is, the distribution of the amount of the reactive color ink applied in the PCBk region, is determined by experiments. it can. In that case, first, PCBk
The recording image is recorded on the recording paper by changing the ratio of the reactive color ink in the area. Next, an image state of at least a region adjacent to the PCBk region in the black ink recording region recorded with only black ink in the recorded recording image is determined. Next, based on the determination result, the PCBk
What is necessary is just to determine the distribution of the ratio of the reactive color ink in the region.

Specifically, P in the black ink recording area
At the stage of determining the image state of the area adjacent to the CBk area,
The density of the black ink in the adjacent area is visually determined, and then a condition that the density of the black ink in the adjacent area exceeds a predetermined density is set in the area adjacent to the black ink recording area in the PCBk area. What is necessary is just image data to be recorded.

(Second Embodiment) In a color ink jet recording method according to a second embodiment of the present invention, a black image is recorded only with black ink and a first PCBk area adjacent to a color ink recording area. By providing the second PCBk area between the black ink recording area and the black ink recording area, the white haze on the PCBk area side in the black ink recording area of only the black ink is suppressed. Also in the present embodiment, plain paper (N) is used as a recording paper as a recording medium for image recording.
SK, NDK).

In the color ink jet recording method of this embodiment, in order to suppress bleeding between the color ink recording area and the black image area, White (R, G, B = 255, 255, 255) and Bl
raster (a row of dots forming a horizontal line extending in a direction parallel to the scanning direction of the recording head on the recording paper) containing colors other than ack (R, G, B = 0, 0, 0), and A black image of 9 rasters at the top and bottom (300 dpi (dpi: the number of dots per 25.4 mm)) is recorded by PCBk. 9 rasters P above and below
The pixel area of CBk is the first PCBk area. The configuration of the PCBk in the first PCBk area is as follows: Cyan (cyan) = 48/255, Magenta (magenta) = 24/255, Yellow as the proportion of each color in 256 dots (0 to 255) of 16 × 16. (Yellow) = 12/255, Black
(Black) = 255/255.

In the first PCBk area, a reactive color ink is used as one of the four color inks as in the first embodiment. Thereby, the first P
The density difference between the ink in the CBk region and the black ink is reduced. In addition, the use of reactive color inks
Since the amount of color ink shot in the area is reduced,
Even with PCBk, the character thickening amount becomes small. These black images other than the first and second PCBk areas are recorded only with black ink. Also, in order to suppress white haze on the PCBk area side in the black ink recording area containing only black ink, the black ink is used. A second PCBk area for 9 rasters (300 dpi) was provided between the recording area and the first PCBk area. The configuration of the PCBk in the second PCBk area is 16 × 1
6 as 256% (0-255), Cyan = 8/255, Magenta = 4/255, Yellow =
2/255, Black = 255/255.

As described above, by making the amount of each color ink applied in the second PCBk area smaller than that in the first PCBk area, the density difference between the black ink and PCBk becomes smaller, and the black ink recording area becomes smaller. 2 P
White haze on the CBk region side is suppressed.

FIG. 6 is a diagram for explaining the use of ink in the color ink jet recording method of this embodiment. FIG. 6A shows first and second images on recording paper.
FIG. 6 is a diagram schematically showing the arrangement of the PCBk region of FIG.
FIG. 7B is a diagram illustrating a distribution of the ejection amount of the color ink in the black image area illustrated in FIG.

As shown in FIG. 6A, the color image area 21 and the black image area 22 are adjacent to each other, and the areas of the black image area 22 on the color image area 21 side are sequentially arranged from the color image area 21 side. A first PCBk area 23 and a second PCBk area 24 are provided. And the second PCB
A black ink recording area 25 is adjacent to the k area 24. The black ink recording area 25 is an area where a black image is formed using only black ink. Therefore, the first PCBk area 23 and the second PCBk area 24 are provided between the black ink recording area 25 and the color image area.

As shown in FIG. 6B, the second PCB
The ejection amount of the color ink in the k region 24 is smaller than the ejection amount of the color ink in the first PCB k region 23. That is, in the entire PCBk area including the first PCBk area 23 and the second PCBk area 24, the ratio of the reactive color ink in the area in contact with the color image area 21 is the reaction in the area in contact with the black ink recording area 25. Is relatively larger than the ratio of the neutral color ink.

The first PCBk area 23 is an area for suppressing bleeding between color ink and black ink.
In this area, the reactive color ink that reacts with the black ink is recorded in the area recorded with the black ink,
It promotes aggregation of black ink and suppresses bleeding between color ink and black ink. In addition, it is necessary to match the color tone of the black ink recording area 25 with that of the area by recording an ink that does not react with the black ink in this area.

The second PCBk area 24 is an area for reducing white haze generated in a portion of the black ink recording area 25 on the first PCBk23 side. This second P
By providing the CBk area 24, it is possible to suppress the permeation of the black ink into the paper in the portion of the black ink recording area 25 that is in contact with the PCBk area by recording a small amount of color ink. Of the black ink in the black ink recording area 25 can be suppressed. Here, since the first PCBk area 23 and the second PCBk area 24 are areas where color inks having good permeability are used, white haze does not occur. Need to be adjusted.

In the color image area 21, black (R,
G, B = 0, 0, 0) uses a PCBk component having the same configuration as the first PCBk area 23.

When discriminating between a black image area and a color image area, a raster composed of white (R, G, B = 255, 255, 255) and black (R, G, B = 0, 0, 0) is converted to black. The image area 22 is determined, and if data other than white and black exists, the color image area 21
Judge. The black image area 22 is in contact with the color image area 21 and is one upper and lower part from the color image area 21.
An area separated by ９9 rasters (300 dpi) is determined as the first PCBk area 23. Also, a black image area 22 adjacent to the color image area 21 via the first PCBk area 23 and an area 10 to 18 rasters (300 dpi) away from the color image area 21 is determined as the second PCBk area 24. I do.

FIG. 7 shows the first and second Ps shown in FIG.
FIG. 4 is a diagram for describing a configuration of ink in a CBk area. FIGS. 7A to 7D show four vertical columns each forming a part of a PCBk area on a recording sheet.
FIG. 7 is a diagram illustrating an example of a dot pattern of each ink in a dot matrix of four rows (4 × 4). 7A illustrates a dot pattern of yellow ink, FIG. 7B illustrates a dot pattern of magenta ink, FIG. 7C illustrates a dot pattern of cyan ink, and FIG. Is a diagram showing a dot pattern of black ink.

For example, as shown in FIG.
For the dot matrix of No. 4, two dots of the yellow ink 31 are ejected at positions separated from each other, and for the same dot matrix, the magenta ink is set at a position separated from each other as shown in FIG. 32 32 dots are printed. Then, for the same dot matrix, as shown in FIG. 7C, eight dots of the cyan ink 33 are printed at positions that are not adjacent to each other in the vertical and horizontal directions. As shown in FIG. 7D, dots of the black ink 34 are printed on all the areas for the risk. Thus, FIG.
By superimposing the dot patterns of the inks of the respective colors shown in FIG. 7D, black in the PCBk area is formed. Actually, the first PCBk area 23 shown in FIG.
And in each of the second PCBk areas 24, the ratio of the color ink of each color corresponding to each area,
The color ink of each color is superimposed on the black ink.

FIG. 8 is a diagram for explaining effects obtained by the color ink jet recording method of the present embodiment described with reference to FIG. FIG. 8A is a diagram schematically showing the arrangement of the first and second PCBk areas on a recording sheet according to the recording method of the present embodiment, similarly to FIG. 6A. 9) is a cross-sectional view of the recording sheet in the area shown in FIG.

As shown in FIGS. 6A and 8A, the first PCBk area 23 and the second PCBk area 24 are located between the color image area 21 and the black ink recording area 25. If the color image area 2 is provided in this order from the side 21, as shown in FIG.
1. The respective inks of the first PCBk area 23 and the second PCBk area 24 have permeated into the recording paper due to the ejection of the color ink. Therefore, the respective inks of the color image area 21, the first PCBk area 23, and the second PCBk area 24 penetrate deeper into the recording paper than the ink of the black ink recording area 25, and the surface layer of the recording paper , The color image area 21, the first PCBk area 23, and the second PCBk area 24 correspond to the permeation area 26.

In the permeation area 26, water, a solvent, a surfactant and the like constituting the ink permeate the recording paper. The second PCBk region 24 in this permeation region 26
In the side end region 27, the amount of the color ink applied to the second PCBk region 24 is small, so that the amount of the surfactant is also small. Thus, the second PC
The second PCBk area 24 and the black ink recording area 25
Of the black ink recording area 2
The black ink of No. 5 is on the color ink side, that is, the second PCB
8B is not much drawn toward the k region 24 side. As a result, white haze is suppressed in the portion of the black ink recording area 25 on the second PCBk area 24 side.

[0092]

As described above, according to the present invention, the black ink and the reactive color on the recording medium are prevented from blurring at the boundary between the color ink recording area and the black ink recording area on the recording medium. In the area where the ink is superimposed, the ratio of the reactive color ink to the black ink corresponds to the distance from the black ink recording area at least in the area adjacent to the black ink recording area in the area in contact with the black ink recording area. Then, by decreasing from the color ink recording area side toward the black ink recording area side, the occurrence of white haze in the black ink recording area due to the difference in permeability between the color ink and the black ink is suppressed, and There is an effect that disturbance of the image is prevented and a high-quality black image can be recorded. In addition, at least one reactive color ink exhibiting mutual reactivity with the black ink is superimposed on the black ink in at least an area adjacent to the color ink recording area in a black image area forming a black image on the recording medium. Because
The occurrence of bleeding at the boundary between the image recorded with black ink and the image recorded with color ink is prevented. Accordingly, the image is prevented from being disturbed at the boundary between the black image and the color image, and both the printing of a high-quality black image and the printing of a high-quality color image are realized.

Further, according to the present invention, black ink and reactive color ink are superimposed on a recording medium in order to prevent bleeding at the boundary between the color ink recording area and the black ink recording area. The area of the reactive color ink in the area in contact with the color ink recording area within the area in contact with the black ink area is relatively larger than the rate of the reactive color ink in the area in contact with the black ink recording area. This has the effect of suppressing the occurrence of white haze in the black ink recording area due to the difference in the permeability of the black ink, preventing the disturbance of the black image, and enabling the recording of a high-quality black image. In addition, at least one reactive color ink exhibiting mutual reactivity with the black ink is superimposed on the black ink in at least an area adjacent to the color ink recording area in a black image area forming a black image on the recording medium. Therefore, the occurrence of bleeding at the boundary between the image recorded with black ink and the image recorded with color ink is prevented. Accordingly, the image is prevented from being disturbed at the boundary between the black image and the color image, and both the printing of a high-quality black image and the printing of a high-quality color image are realized.

Further, according to the present invention, in order to prevent bleeding at a boundary portion between a color ink recording area and a black ink recording area on a recording medium, a first image adjacent to the color ink recording area in a black image area is provided. The black ink and the reactive color ink are superimposed on each other in a region, and the reactive color for the black ink is formed in a second region between the first region and the black ink recording region in the black image region. The occurrence of white haze in the first and second areas in the black image area and the black ink recording area by superimposing the black ink and the reactive color ink with the ink ratio being smaller than that of the first area. Is suppressed, and the black image is prevented from being disturbed, so that a high-quality black image can be recorded. Further, at least one reactive color ink that is reactive with the black ink is superimposed on the black ink in an area adjacent to the color ink recording area in the black image area forming the black image on the recording medium. Therefore, the occurrence of bleeding at the boundary between the image recorded with black ink and the image recorded with color ink is prevented. As a result, the image is prevented from being disturbed at the boundary between the black image and the color image, and both the printing of a high-quality black image and the printing of a high-quality color image are realized.

Further, according to the method for determining the ratio of the color ink of the present invention, the ratio of the reactive color ink in the overlapping area of the black ink and the reactive color ink on the recording medium is changed to change the ratio of the reactive color ink. Record the recorded image in the
Since the distribution of the ratio of the reactive color ink in the overlapping area is determined based on the determination result of the recorded image,
It is possible to find an optimum printing condition that can suppress the occurrence of white haze in the black ink printing area. Therefore, it is possible to prevent the image from being disturbed at the boundary between the black image and the color image, and to obtain an optimum recording condition capable of realizing both high-quality black image recording and high-quality color image recording. be able to.

[Brief description of the drawings]

FIG. 1A is a perspective view of a recording head cartridge suitable for an ink jet recording apparatus to which a color ink jet recording method of the present invention is applied or applied, and FIG. 1B is an exploded perspective view thereof.

FIG. 2 is an exploded perspective view showing the configuration of the recording head shown in FIG.

FIG. 3 is a perspective view illustrating a bottom surface side of the recording head illustrated in FIG. 1;

FIG. 4 is a plan view for describing a color inkjet recording method according to the first embodiment of the present invention.

FIG. 5 is a diagram for explaining a change in the ratio of a reactive color ink in a PCBk region according to the color inkjet recording method of the present invention.

FIG. 6 is a diagram illustrating the use of ink in a color inkjet recording method according to a second embodiment of the present invention.

FIG. 7 is a diagram for describing a configuration of ink in first and second PCBk areas shown in FIG. 6;

8 is a diagram for describing an effect obtained by the color inkjet recording method described with reference to FIG.

FIG. 9 is a diagram for explaining the principle of generating white haze at a boundary between a color image area and a black image area.

FIG. 10 is a diagram for describing occurrence of “white haze” at a boundary between a black image area and a color image area.

FIG. 11 is a diagram for explaining occurrence of white haze in a black ink recording area adjacent to a superimposed area of black ink and reactive color ink.

FIG. 12 is a diagram for describing a change in the influence of the PCBk area on an area recorded with only black ink when the amount of color ink ejection in the PCBk area is changed.

FIG. 13 is a diagram illustrating a configuration of ink in a PCBk area illustrated in FIG. 12;

FIG. 14 is a diagram illustrating a configuration of ink in a color image area illustrated in FIG. 12;

FIG. 15 is a diagram illustrating a configuration of ink in a black ink recording area illustrated in FIG. 12;

[Explanation of symbols]

1 color ink recording area 2a, 23 first PCBk area 2b, 24 second PCBk area 2c, 13 PCBk area 3a, 3b, 15, 25 black ink recording area 4 reactive color ink 11, 21 color image area 12, 22 Black image area 13a, 13b Adjacent area 26 Penetration area 27 End area 31 Yellow ink 32 Magenta ink 33 Cyan ink 34 Black ink H1000 Printhead cartridge H1001 Printhead (inkjet printhead) H1002 Print element unit H1003 Ink supply unit H1011 Black (Black) Ink ejection port array H1012 Cyan ink ejection port array H1013 Magenta ink ejection port array H1014 Yellow ink ejection port array H1900 Ink tank H1901 Black (black) Ink tank H1902 cyan ink tank H1903 magenta ink tank H1904 yellow ink tank H2000 tank holder H2200 electric contact board H2300 joint seal member H2400 screw

Claims (7)

[Claims] When a desired color image is recorded on a recording medium in accordance with recording data using a color ink and black ink having different permeability to the recording medium, the color ink is used as the color ink. On a recording medium, to prevent bleeding at a boundary between a color ink recording area recorded using the color ink and a black ink recording area recorded only with the black ink, In a color ink jet recording method in which at least one reactive color ink exhibiting mutual reactivity with the black ink is overlapped with the black ink in at least a region adjacent to the color ink recording region in a black image region constituting a black image. The region where the black ink and the reactive color ink are superimposed on the recording medium is recorded only with the black ink. At least part of the black ink recording region side in the area in contact with the black ink recording region, the proportion of the reactive color ink to the black ink,
A color ink jet recording method, comprising: decreasing the color ink recording area in a direction from the color ink recording area to the black ink recording area according to a distance from the black ink recording area. 2. The method according to claim 1, wherein the color ink and black ink having different permeability to the recording medium are used for recording a desired color image on the recording medium in accordance with recording data. On a recording medium, to prevent bleeding at a boundary between a color ink recording area recorded using the color ink and a black ink recording area recorded only with the black ink, In a color ink jet recording method in which at least one reactive color ink exhibiting mutual reactivity with the black ink is overlapped with the black ink in at least a region adjacent to the color ink recording region in a black image region constituting a black image. In the area where the black ink and the reactive color ink are superimposed on the recording medium, the area is in contact with the color ink recording area. Color ink jet recording method characterized by that the ratio of the reactive color ink in the region, to relatively greater than the proportion of the reactive color ink in the area in contact with the black ink recording region. 3. The reactive color ink according to claim 1, wherein a ratio of the reactive color ink is continuously changed in a region where the black ink and the reactive color ink are superimposed on the recording medium. Color inkjet recording method. 4. The recording medium according to claim 1, wherein the ratio of the reactive color ink is changed stepwise in an area where the black ink and the reactive color ink overlap each other. Color inkjet recording method. 5. A method for recording a desired color image on a recording medium according to recording data using a color ink and a black ink having a different permeability to the recording medium. On a recording medium, to prevent bleeding at a boundary between a color ink recording area recorded using the color ink and a black ink recording area recorded only with the black ink, In a color ink jet recording method in which at least one reactive color ink exhibiting mutual reactivity with the black ink is overlapped with the black ink in at least a region adjacent to the color ink recording region in a black image region constituting a black image. The black ink and the reactive color ink in a first area adjacent to the color ink recording area in the black image area; In the second area sandwiched between the first area and the black ink recording area in the black image area, the ratio of the reactive color ink to the black ink is set to the first area. Wherein the black ink and the reactive color ink are overlapped with each other so as to be smaller than the area of (1). 6. A color ink jet recording method for recording a desired color image on a recording medium according to recording data using a color ink and a black ink having different permeability to the recording medium. The recording medium for preventing bleeding at a boundary between a color ink recording area recorded using the color ink and a black ink recording area recorded only with the black ink on the recording medium. In an area adjacent to at least the color ink recording area in a black image area constituting a black image above, at least one reactive color ink showing mutual reactivity with the black ink is overlapped with the black ink, Determining the ratio of the reactive color ink in an overlapping area of the black ink and the reactive color ink on the recording medium, A method of determining a ratio of color ink, wherein a ratio of the reactive color ink in the overlapping area is changed to record a recording image on a recording medium, and the black ink of the recorded recording image is Determining an image state of at least an area adjacent to the superimposition area in the black ink recording area recorded only by the image forming apparatus; and determining a distribution of the ratio of the reactive color ink in the superimposition area based on the determination result. Determining the ratio of the color ink. 7. The step of determining an image state of an area adjacent to the overlapping area in the black ink recording area, visually determining a density of the black ink in the adjacent area, In the step of determining the ratio of the reactive color ink, a condition such that the density of the black ink in the adjacent area exceeds a predetermined density is recorded in an area adjacent to the black ink recording area in the overlapping area. 7. The method according to claim 6, wherein the ratio of the color ink is image data.