JPH1111000A - Ink jet recording method and ink jet recorder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To form a clear color image of a color image having excellent uniformity of a solid part by specifying surface tension of color ink and surface tension of recordability improving liquid, and specifying a ratio of giving amount of the improving liquid to giving amount of the ink on a partial area of the image. SOLUTION: In a printer having a carriage 2 for mounting a recording head 1s for discharging recordability improving liquid and recording heads 1k, 1c, 1m and 1y for respectively discharging black, cyan, magenta and yellow inks, surface tension γ1 of color ink is set to 30 dyn/cm<γ1<=40 dyn/cm, and surface tension γ2 of the improving liquid is set to 30 dyn/cm<γ2<=40 dyn/cm. A giving amount X1 of the improving liquid at least on partial area of the image and an ink amount X2 given to the partial area are set to satisfy the relation of X1/X2<1. And, the improving liquid contains compound for insolubilizing or aggregating coloring materials contained in the ink.

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 and an ink jet recording apparatus, and more particularly, to an ink jet recording method in which an ink and a liquid for insolubilizing or aggregating a coloring material in the ink are ejected onto a recording material to perform recording. The present invention relates to a method and an inkjet recording apparatus. The present invention can be applied to all devices that use a recording material such as paper, cloth, nonwoven fabric, and OHP paper. Specific devices include office machines such as printers, copiers, and facsimile machines, and mass-production machines such as printing machines. Can be mentioned.

[0002]

2. Description of the Related Art Conventionally, paper, cloth, plastic sheet, O
An ink jet recording method for recording on a recording medium (hereinafter simply referred to as recording paper) such as an HP sheet is capable of high-density and high-speed recording. Machine, facsimile, electronic typewriter, word processor, printer as an output terminal such as a workstation, or a personal computer, a host computer, an optical disk device, a handy or portable printer provided in a video device, etc., and these devices are used. It has been commercialized.

[0003] In this case, the ink jet recording apparatus has a configuration corresponding to the functions, usage patterns and the like specific to these apparatuses. Generally, an ink jet recording apparatus includes a carriage on which a recording unit (recording head) and an ink tank are mounted,
A transport unit for transporting the recording paper and a control unit for controlling these units are provided. Then, the recording head for ejecting ink droplets from the plurality of ejection ports is scanned (serial scan) in a direction (main scanning direction) orthogonal to the recording paper conveyance direction (sub-scanning direction), and during this scanning, the recording paper is scanned. Is transported by an amount equal to the recording width of the recording head. This method performs recording by discharging ink on recording paper in accordance with a recording signal, and is widely used as a quiet recording method with low running cost. In addition, by using a recording head in which a plurality of nozzles for ejecting ink are arranged in a straight line, the recording head scans on recording paper to perform recording with a width corresponding to the number of nozzles arranged in the sub-scanning direction. Therefore, it is possible to achieve a high-speed recording operation.

Further, recently, an apparatus capable of forming a full-color image using such a recording head for three to four colors of ink has been put to practical use. This apparatus is, for example, three primary colors of yellow (Y), magenta (M), and cyan (C), or four primary colors including black (black; B).
Four types of recording heads and ink tanks corresponding to colors can be mounted.

[0005]

However, according to the conventional ink jet recording method and apparatus, it is possible to prevent ink bleeding between black, yellow (Y), magenta (M) and cyan (C) colors, and to improve black image height. Since the densification and the prevention of feathering are contrary to each other, it is often difficult to achieve the print quality of color recording to a level sufficient to meet the needs of the user. The reason will be described below.

Usually, when a color image is obtained on plain paper by an ink jet recording method, a quick-drying ink having a high penetration rate into plain paper is used. Accordingly, it is possible to prevent the ink from bleeding in the boundary region between the colors constituting the image. However, when a quick-drying ink is used, the density of the black image portion is low, while the color image portions other than black have low coloring properties. Furthermore, when a line drawing represented by characters or the like is recorded, ink bleeds along the fibers of the paper,
So-called feathering may occur. In particular, characters printed with black ink are more conspicuous in feathering than those in other colors, and are so-called unclear characters lacking sharpness. As a result, the quality of the recorded image is significantly reduced as a whole.

In general, in order to obtain a high-quality image in which the density of a black image portion is high and feathering does not occur, it is necessary to eject ink having a relatively low penetration rate into plain paper to some extent. However, in this case, bleeding occurs between the black ink and the color ink at the adjacent boundary between the black image portion and the color image portion, and the quality of the recorded image is significantly impaired.

In order to solve these problems, a system has been put to practical use in which a heater is provided in the recording apparatus to promote drying of the ink and obtain a color image having high color development and no bleeding between colors. However, in this method, there is an inevitable problem that the size of the apparatus and the cost are increased.

As described above, the prevention of ink bleeding between black and each color and the prevention of high density and prevention of feathering of a black image have been contradictory subjects.

Therefore, Japanese Patent Application Laid-Open No. 3-146355 proposes a method in which recording is not performed in an area along a boundary between black and color. However, this method has a problem that data to be recorded changes.

Japanese Patent Application Laid-Open No. Hei 4-15849 discloses a color head and a character recording head for each of a plurality of colors for color recording, and a color head and a character recording head based on a recorded image. There is proposed a method of switching and recording. However, in this method, when a black image recorded by a color recording head and a black image recorded by a character recording head are mixed, a sense of incongruity may occur due to a difference in quality between the two.

Further, there is also known a method in which a black region along a boundary between black and color is formed by over-printing color ink to prevent bleeding in the boundary between black and color. In principle, black can also be obtained by superimposing (mixing) three colors of Y, M, and C. However, a black image formed by mixing color inks in this manner is different from a normal black ink. Usually, the coloring property is poor.

On the other hand, JP-A-56-84792 and JP-A-64-63185 disclose a technique using a liquid for insolubilizing a dye in ink.

Japanese Patent Application Laid-Open No. 56-84792 discloses a method in which a material for fixing a dye is previously coated on recording paper. However, in this method, it is necessary to use a specific recording paper, and since a material for fixing the dye is applied in advance, an increase in the size of the apparatus and an increase in cost cannot be avoided, and furthermore, a stable recording paper is required. Therefore, there is a problem to be solved such that it is difficult to apply the above-mentioned material at a predetermined film thickness.

Japanese Patent Application Laid-Open No. 63-63185 discloses a technique in which a colorless ink for insolubilizing a dye is deposited on recording paper by an ink jet recording head. According to this method, the dot diameter of the colorless ink is made larger than the dot diameter of the image ink. Therefore, even when the mounting position of the image ink and the colorless ink is displaced, the desired characteristic for insolubilization is obtained. It is said that can be satisfied. However, in this method, since the amount of colorless ink that is applied to the portion corresponding to the image position is larger than usual, the problem to be solved is that not only the drying time of the ink is prolonged, but also a relatively unclear image may result. there were.

Furthermore, Japanese Patent Application Laid-Open No. Hei 7-195823 discloses that a colorless printing can be performed particularly in one pass by applying a colorless precursor to the surface of a recording medium prior to ink jet recording.

As described above, the methods disclosed in the above-mentioned documents using the liquid for insolubilizing the ink have problems to be solved, but the method for insolubilizing the dye in the ink is not suitable for color recording. When applied, there is a possibility that the bleeding of the ink between the colors can be prevented.

Therefore, the present applicant has solved the above-mentioned problems and has realized a low running cost by minimizing the consumption of the liquid while using a liquid for insolubilizing the dye. We have proposed an ink jet recording method that exhibits superior water resistance, can obtain high-density images, and can obtain high-color images without blurring between colors when applied to color recording ( JP-A-8-281974).

The present invention is a further improvement and development of the recording method disclosed in the above-mentioned Japanese Patent Application Laid-Open No. 8-281974, which solves the above-mentioned problems and minimizes the consumption while using an ink for insolubilizing a dye. It realizes low running cost by suppressing it, shows superior water resistance even on plain paper, and can obtain high-density images, and has high color development without bleeding between colors in color recording An object of the present invention is to provide an ink jet recording method and an ink jet recording apparatus capable of obtaining a clear image.

[0020]

According to the present invention, there is provided:
An ink jet recording method for forming an image by applying a color ink and a recording property improving liquid for improving the recording property of the color ink to a recording material, wherein the surface tension γ1 of the color ink is 30 dyn / cm <γ1. ≤40 dyn / c
m, the surface tension γ2 of the recording improving liquid is 30 dyn / c
m <γ2 ≦ 40 dyn / cm, and the applied amount X1 of the printability improving liquid in at least a part of the image and the ink amount X2 applied to the part of the image
Satisfies X1 / X2 <1.

Further, a recording head for discharging color ink and a recording head for discharging a recording property improving liquid for improving the recording property of the color ink are used to discharge the color ink and the recording property improving liquid onto a recording material to form an image. An ink jet recording apparatus for recording, wherein a surface tension γ of the color ink
1 is 30 dyn / cm <γ1 ≦ 40 dyn / cm, and the surface tension γ2 of the recording property improving liquid is 30 dyn / cm <γ2.
≦ 40 dyn / cm, and the application amount X1 of the recording property improving liquid in at least a part of the area of the image.
And the ink amount X2 applied to the partial area is X1 / X1
A printing head for discharging the color ink and a printing head for discharging the printability improving liquid so as to satisfy X2 <1 are provided.

According to the above construction, the surface tension of each of the color ink and the recording property improving liquid is set to an appropriate range, and the amount of the recording property improving liquid applied to the color ink is reduced. The coloring property can be increased even when a recording material such as plain paper having a relatively low permeability and a low permeability is used, and a clear image can be formed by preventing feathering. Can be. By using a recording property improving liquid having the same degree of permeability as that of the color ink, it is possible to prevent beading and connecting streaks and to make the permeability when mixed with the color ink appropriate.

[0023]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The ink jet recording method of the present invention is particularly applicable to recording of a single scan (one pass) of a recording head.
In order to obtain a clear, high-density, and highly uniform color image with no ink bleeding on plain paper, the surface tension should be 30 to
40dyn / cm color ink and surface tension of 30 ~
A recording property improving liquid of 40 dyn / cm is used, and the application amount of the recording property improving liquid is smaller than the application amount of the ink.

The recording-enhancing liquid contains a compound that insolubilizes or aggregates a coloring material such as a dye contained in the ink, so that the water resistance of the image is greatly improved. In particular, prior to the application of the color ink, It is preferable to apply it.

The color ink is preferably cyan, magenta, and yellow in order to form a normal full-color image.

Further, the above-mentioned recording property improving liquid contains a cationic substance comprising a low molecular component and a high molecular component,
Further, the dye as the coloring material contained in the ink comprises an anionic substance.

The recording property improving liquid contains a cationic substance composed of a low molecular component and a high molecular component. The ink contains an anionic dye or at least contains an anionic compound and a pigment. Is included.

In the following, the process leading to the above configuration will be described.
This will be described in detail.

The inventor of the present application has made intensive studies in order to obtain a clear, high-density, and highly uniform image on plain paper in one pass.

First, as a first condition, it is preferable to use, as the color ink, an ink having relatively low permeability to plain paper (hereinafter referred to as “addition ink”).

As described in the above-mentioned prior art, when a quick-drying color ink having a high permeability to plain paper is used, it is possible to prevent the ink from bleeding in a boundary region of each color.
However, when the coloration of the image is low, and when a line drawing represented by characters or the like is recorded, feathering occurs and an unclear image lacking in sharpness occurs. That is, when such a quick-drying color ink is used, even if a recording property improving liquid having a function of insolubilizing or aggregating the coloring material in the ink is applied prior to the application of the color ink, the permeability of the color ink is reduced. Dominated, the resulting image will be blurry, lacking sharpness.

On the other hand, when a color ink having low permeability is used, a sharp and clear color image can be obtained, and the application of the recording improving liquid can also prevent the ink in the boundary region of each color from bleeding. There is a problem that the fixing time becomes long because the speed of penetration into the plain paper becomes slow.

Therefore, it is preferable that the permeability of the color ink used is lower than that of the quick-drying color ink used in a commercially available color printer. In this case, it goes without saying that unless the recording property improving liquid is applied, ink bleeding occurs in the boundary region of each color.

Next, as a second condition, it is preferable that the permeability of the recording property improving liquid is substantially the same as the permeability of the color ink shown in the first condition.

When the permeability of the recording-enhancing liquid is increased, even if a color ink having a low permeability is used according to the first condition, it is dragged by the permeability of the recording-enhancing liquid applied earlier. This is because the color ink also easily penetrates, resulting in an unclear color image lacking in sharpness.

Further, in a normal color printer, black ink is used in addition to the color ink. However, since a black image is required to be sharper than a color image, the permeability of the recording-enhancing liquid is not so enhanced. It is desirable.

On the other hand, if the permeability of the recording-improvement liquid is too low, the penetration speed into plain paper will be slowed down, causing a problem that the fixing time will be prolonged. For this reason, it is preferable to appropriately set the permeability in consideration of the balance between the recording speed and the configuration of the recording apparatus.

Table 1 below illustrates the results of the experiments that reached the first and second conditions described above.
It shows an evaluation result of an image when a color image is printed in one pass.

[0039]

[Table 1]

The solid part coloring in Table 1 is, for example, 100%
Indicates the color developability of the portion recorded with the recording duty of, and a case marked with a cross in this evaluation means that the image becomes a sunken image lacking in the vividness of the image.

In addition, beading refers to a phenomenon in which ink before permeation gathers in a chain on recording paper, and as a result, the color material is partially concentrated, resulting in an image lacking uniformity. This is likely to occur when printing an image with a high print duty, such as a copy. When using the recording property improving liquid, the coloring material in the ink rapidly reacts with the recording property improving liquid,
It is considered that the coloring material is partially collected due to the wettability of the ink and the recording property improving liquid on the recording paper.

The connecting streak refers to a streak generated at the joint between each scan (pass) which occurs when printing is performed in one pass. In the recording using only the color ink without using the normal recording property improving liquid, the end of the image formed in each scan (the end on the downstream side in the paper feeding direction) is liable to cause the ink to spread (bleed). Unnecessary overlap occurs with the ink dots applied in the scan, and this overlap tends to become a black streak at a joint between scans. On the other hand, when the recording property improving liquid is used, since the spread of the ink tends to be suppressed by the recording property improving liquid, the above-described black streak is hardly generated, but for example, the conveyance amount of the recording paper is larger than the set value. When the number of dots increases, the overlapping portion of the dots decreases, and conversely, white stripes tend to occur.

As is clear from Table 1 above, in order to obtain a sharp and clear color image, it is preferable that the permeability of the color ink is lower (case 3,
4).

Therefore, if the permeability of the recording property improving liquid is increased while the permeability of the color ink is reduced to some extent, the color developability of the solid portion is particularly impaired (Case 3). Also, when the permeability of the color ink is low, the color line image is almost sharp and clear, but when the black ink is used,
As described above, the sharpness of a black line image is impaired due to the permeability of the recording property improving liquid. On the other hand, if the permeability of the recording-enhancing liquid is lowered, beading occurs and a connecting streak occurs (Case 4).

Regarding the above evaluations in Table 1, even if the permeability of the recording-improvement liquid is changed by several types, the properties shown in Table 1 are in a trade-off relationship, and the permeability satisfying all these properties is as follows. I can't get it.

Therefore, in consideration of obtaining a sharp and clear black line image when using black ink, it is necessary to improve beading and connecting streaks in a direction that does not increase the permeability of the recording property improving liquid. . From this viewpoint, as a third condition, the amount of the recording property improving liquid applied at a time is reduced. As a result, the occurrence of beading could be substantially suppressed, and the tendency of the connecting streak to decrease was obtained.

Regarding the third condition, as a method of reducing the applied amount of the recording property improving liquid, a predetermined amount X
It is possible to adopt a method in which the modification data obtained by thinning (%) is used as data for applying the recording property improving liquid. For example, for solid image data as shown in FIG. 1A, the amount of application can be reduced by using a thinning mask as shown in FIG. 1B, FIG. 1C or FIG. Further, instead of such a thinning method having regularity, a thinning mask having randomness may be used. However, it is desirable to use a large-sized mask in order to provide randomness.

As described above, beading mainly occurs when a solid portion having a high duty is recorded. Usually, a color image is formed by using black for the three primary colors of cyan, magenta, and yellow. However, a solid area of the three primary colors, which are primary colors, and a solid area of the secondary colors of red, blue, and green have a unit area. The amount of ink applied per hit differs. Therefore, in order to prevent beading by thinning, it is preferable that thinning is performed so that the applied amount of the printability improving liquid to the ink amount applied per unit area, that is, the applied rate is constant regardless of the color to be expressed. However, when the data processing or the like for that purpose becomes complicated, the data of the printability improving liquid may be generated by thinning out a predetermined amount from the data obtained by ORing the data of the three primary colors of yellow, magenta and cyan. .
In this case, the application amount of the recording property improving liquid applied to the cyan solid and the blue (cyan + yellow) solid is the same, but the application ratio is different. For example, when the thinning rate of the recording property improving liquid applied to the solid portion of cyan is 50%, the applying rate is also 50%. However, when the same thinning rate is applied to the solid portion of blue, the applying rate of the recording property improving liquid is Is 25% of the total amount of cyan ink and yellow ink applied to the blue image.

In order to minimize the difference between the application amount of the recording property improving liquid and the application ratio with respect to the total amount of the inks applied in the primary color and the secondary color, the data of the three primary colors is set to a predetermined value. It is also possible to thin them out at a ratio and take a logical sum of them, which simplifies the processing and obtains a desired amount of the recording property improving liquid to be applied. In this case, it is necessary to make the thinning mask different for each color. For example, when a random mask having a different randomness is used for each color, the applied amount of the printability improving liquid is 1 to the applied amount of the ink.
The solid color of the secondary color and the solid color of the secondary color are constant.

However, the thinning mask for each color can be different up to the thinning rate of 33%. However, when the thinning rate exceeds 33%, pixels having the same mask for each color are generated. In this case, the rate at which the recording property improving liquid is applied to the secondary color is lower than the rate at which the recording property improving liquid is applied to the primary color. For example, assuming that a 50% thinning mask for each color is used, and that the overlap ratio between the colors is 20% of the whole, the application rate of the printability improving liquid for the primary color is 50%. In the secondary color, the non-overlapping portion is 30% for each color, and the overlapping portion is 20%.
As a whole, the recording property improving liquid is applied to the area of 30% + 20% + 30% = 80%. Since the ink amount of the secondary color is 200%, the application rate of the recording property improving liquid is 80%.
/200=0.4 (40%).

As another method for making the applied amount of the recording-improvement liquid smaller than the applied amount of ink, there is a method of setting the ejection amount of the recording-enhancing liquid itself to be smaller than the ejection amount of the ink. The setting of the discharge amount can be realized by changing the structure of the nozzles and the like of the print head, and changing the driving conditions of the print head.

The area in which the application amount of the recording property improving liquid is reduced may be the entire area of the image to be recorded, or may be only the high-duty part where the effect of the present invention is best obtained.

The third condition has been described in which the application amount of the recording property improving liquid is made smaller than the application amount of the ink. However, the permeability of the color ink or the recording property improving liquid is increased or decreased. It has been clarified by the inventors that the effect is almost negligible even if the amount of the recording property improving liquid applied is reduced in this state.

Here, the permeability of the color ink and the recording property improving liquid is determined by the surface tension γ (dyn / c
m) can be substituted. A color ink having a large surface tension or a recording property improving liquid has poor wettability to recording paper and low permeability to recording paper. On the other hand, a color ink having a small surface tension or a recording property improving liquid has good wettability to recording paper and has high permeability to recording paper.

According to the above examination results, the surface tension (dyn / cm) of the color ink preferably satisfies 30 ≦ γ ≦ 40. Further, from the viewpoint of the sharpness and the color developing property of the color line image, it is preferable that 31 ≦ γ ≦ 39, and more preferably, from the viewpoint of beading and connecting streaks, 32 ≦ γ ≦ 36.

On the other hand, the surface tension of the recording property improving liquid is 3
It is preferable that 0 <γ ≦ 40. Further, from the viewpoint of beading, it is preferable that 30 <γ ≦ 38, and more preferably 30 <γ ≦ 36.

Regarding the reduction of the amount of the recording property improving liquid to be applied, it is preferable that the ratio X (%) of thinning out a predetermined amount from the image data in order to generate the data is 33 ≦ X ≦ 75. Further, from the viewpoints of ink bleeding, water resistance, beading, and connecting stripes in the boundary region of each color, it is preferable that 50 ≦ X ≦ 75, and 50 ≦ X ≦ 75.
It is more preferable that X ≦ 66.

As described above, in order to obtain a clear, high-density, and highly uniform color image on plain paper in one pass, the surface tension of the color ink and the recording property improving liquid and the recording property improving liquid are applied. The thinning rate for generating the data to be processed must satisfy each of the above conditions.

It should be noted that the improvement of the recording property means to improve each element relating to image quality such as density, chroma, degree of sharpness of an edge portion, dot diameter, etc., to improve fixability of ink, water resistance and light resistance. Includes the meaning of improving the weather resistance such as the property, that is, improving the image storability.

Further, the insolubilization is effected by an ionic interaction between an anionic group contained in the dye in the ink and a cationic group of the cationic substance contained in the recording-enhancing liquid to form an ionic bond. This is a phenomenon in which a coloring material (dye), which has been uniformly dissolved in water, is separated from the solution. In the present invention, even if all the dyes in the ink are not insolubilized, the effects of improving the density, improving the character quality, and improving the fixing property can be obtained.

In the case where the coloring material used in the ink is a water-soluble dye having an anionic group, the term “aggregation” is used in the same meaning as insolubilization. When the coloring material used in the ink is a pigment, the cationic group of the cationic substance contained in the pigment dispersant or the pigment surface and the recording property improving liquid causes ionic interaction, and the pigment is dispersed. This includes destruction and an increase in pigment particle size. Usually, the viscosity of the ink increases with the aggregation described above. In the present invention, even if all the pigments or dispersants in the ink are not insolubilized, effects such as improvement in density, improvement in character quality, and improvement in fixability as described in the present invention can be obtained.

[0062]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 2 is a perspective view showing a schematic configuration of an example of an ink jet recording apparatus (ink jet printer) to which the present invention can be applied.

This printer has a recording head 1 s for discharging a recording quality improving liquid, a recording head 1 k for discharging black ink, a recording head 1 c for discharging cyan ink, and a magenta ink. A carriage 2 mounted with a recording head 1m, a recording head 1y for discharging yellow ink, a flexible cable 3 for sending an electric signal from the printer body to the recording head, and a cap unit 4 having recovery means;
Paper feed tray 8 for feeding recording material 7 such as printing paper
Etc. Further, the cap unit 4 includes cap members 5s, 5k, 5c, 5m, and 5y corresponding to the recording heads 1s, 1k, 1c, 1m, and 1y, and a wiper blade 6s corresponding to the recording head 1s made of a member such as rubber. And a wiper blade 6k corresponding to the recording heads 1k, 1c, 1m, 1y. In the printer having such a configuration, the recording heads 1s, 1k, 1c, 1m, and 1y are moved in a direction (main scanning direction) B orthogonal to the conveying direction A of the recording material.
The recording is performed with a width corresponding to the number of nozzles, and the recording material is conveyed during this recording with a feed amount equal to the recording width.

Recording heads 1s, 1k, 1c, 1m, 1y
Has 128 nozzles at a density of 600 nozzles per inch, about 40 ng of black ink from each nozzle of the print head 1k, and the print heads 1s, 1
Approximately 20 ng of the recording improving liquid or color ink is ejected from each of the nozzles c, 1 m, and 1 y.

The inks of each color ejected by these recording heads and the recording improvement station are stored in two ink tanks 7A and 7B in the form of cartridges, each of which has a storage section. Note that the form of the ink tank is not limited to this, and a cartridge may be provided for each ink and recording property improving liquid, and the cartridge may be mounted on a carriage. Is also good.

FIG. 3 is a block diagram showing a control configuration of the above-described ink jet printer.

Reference numeral 301 denotes a system controller for controlling the entire printer device. The system controller includes a microprocessor, a storage element (ROM) storing a control program, and a microprocessor. It has a storage element (RAM) and the like to be used. Reference numeral 302 denotes a driver that drives a carriage motor for driving the carriage 2 that performs main scanning of the print head. Similarly, reference numeral 303 denotes a drive of a paper feed motor 305 that moves a recording material in the sub-scanning direction. Is a driver that performs Each of the motors 304 and 305 receives a drive signal corresponding to a speed, a moving distance, and the like from a corresponding driver and operates.

Reference numeral 306 denotes a host computer, which is a device for transferring image information and the like to be printed to the printer of this embodiment. Reference numeral 307 denotes a reception buffer for temporarily storing data transferred from the host computer 306, and stores the data until data is read by the system controller 301 of 301. Reference numeral 308 denotes a frame memory for expanding data to be printed into image data, and has a memory size necessary for printing. This embodiment has a memory size capable of storing one print sheet. Reference numeral 309 is a storage element for temporarily storing image data for ejection,
It has a storage capacity for one scan, that is, the number of nozzles of the print head and the scan width. Reference numeral 310 denotes a print control unit that appropriately controls the driving of the recording head in accordance with a command from a system controller. That is, the printing speed, the number of print data, and the like are controlled. Further, the print control unit 310 also creates data for discharging the printability improving liquid. Reference numeral 311 denotes the recording head 1
s, recording head 1k, recording head 1c, recording head 1
m, a driver for driving the recording head 1y, and the driving thereof is controlled by the print control unit 310.

In the above control configuration, the image data from the host computer 306 is temporarily stored in the reception buffer 307. Next, the stored image data is read out by the system controller 301 and expanded in the buffer 309. Print control unit 310
Creates data for ejecting each color ink and printability improving liquid based on the data developed in the buffer 309. Then, the drive of the print head is controlled based on the image data and the printability improving liquid ejection data in each buffer.

Example 1 In this example, the following inks and recording-improvement liquids were used.

(Ink) Yellow triethylene glycol 7 parts by weight Hexanetriol 7 parts by weight Isopropyl alcohol 2.5 parts by weight Acetinol 0.1 parts by weight C.I. I. Direct Yellow 86 1.5 parts by weight Water 81.9 parts by weight 2. Magenta Triethylene glycol 7 parts by weight Hexanetriol 7 parts by weight Isopropyl alcohol 1.5 parts by weight Acetinol 0.1 parts by weight C.I. I. Acid Red 289 1.5 parts by weight Water 82.9 parts by weight C. Cyan triethylene glycol 7 parts by weight Hexanetriol 7 parts by weight Isopropyl alcohol 1.5 parts by weight Acetinol 0.1 parts by weight I. Direct Blue 199 2.5 parts by weight Water 81.9 parts by weight C. Black triethylene glycol 6 parts by weight Hexanetriol 6 parts by weight butyl alcohol 2 parts by weight acetate acetate 0.01 parts by weight I. Direct Black 154 2.5 parts by weight Water 83.49 parts by weight (Recordability improving liquid) Glycerin 7 parts by weight Diethylene glycol 5 parts by weight Polyallylamine (15% aqueous solution) 24 parts by weight Acetic acid (10% aqueous solution) 3.51 parts by weight hydrochloric acid Benzalkonium (51% aqueous solution) 0.96 parts by weight Triethylene glycol monobutyl ether 0.5 parts by weight Water 59.03 parts by weight The surface tension of all yellow, magenta and cyan inks is about 39 dyn / cm, and the black ink Is about 49 dyn
/ Cm, the recording property improving liquid was about 34 dyn / cm.

In the present embodiment, the data of the printability improving liquid discharged from the printhead 1s is Dk for the image data for the printhead 1k, and the image data for the printheads 1c, 1m and 1y is thinned out by 50% each. Dc, Dm, D
As y, a logical sum of Dk, Dc, Dm, and Dy was used. In the above-described 50% thinning method, thinning may be performed regularly according to a predetermined pattern, or may be performed at random. Further, the thinning method may be different for each color. In the present embodiment, randomness is provided, and the thinning method is changed for each color. Accordingly, for example, in the solid portion of the primary color, the applied amount of the recording property improving liquid to the applied amount of ink becomes 50%, and X1 / X2 = 0.5. In the solid portion of the secondary color, the applied amount of the recording property improving liquid with respect to the applied amount of ink is about 37%, and X1 / X2 =
0.37.

The reason why the data of the black image is not thinned out is that the amount of ink per pixel for forming the black image is twice as large as that of the color image. This is because the decrease in image quality described above is relatively inconspicuous as compared with the above.

When a color image was printed in one pass under the above conditions, a slight streak due to the effect of the nozzle of the print head was observed in a part of the image, but the image was sharp and clear.

Example 2 A color image was recorded in one pass under the same conditions as in Example 1 except that the color ink used in Example 1 was changed to the following color ink.

The surface tension of each of the yellow, magenta and cyan inks was about 31 dyn / cm for each color.

(Ink) Yellow triethylene glycol 7 parts by weight Hexanetriol 7 parts by weight Isopropyl alcohol 2.5 parts by weight Acetinol 0.7 parts by weight C.I. I. Direct Yellow 86 1.5 parts by weight Water 81.3 parts by weight 2. Magenta Triethylene glycol 7 parts by weight Hexanetriol 7 parts by weight Isopropyl alcohol 1.5 parts by weight Acetinol 0.7 parts by weight C.I. I. Acid Red 289 1.5 parts by weight Water 82.6 parts by weight C. Cyan triethylene glycol 7 parts by weight Hexanetriol 7 parts by weight Isopropyl alcohol 1.5 parts by weight Acetinol 0.7 parts by weight I. Direct Blue 199 2.5 parts by weight Water 81.6 parts by weight The obtained color image had no stripes and uniformity.

Example 3 A color image was recorded in one pass under the same conditions as in Example 1 except that the color ink used in Example 1 was changed to the following color ink.

The surface tension of the yellow, magenta, and cyan inks was 34 dyn / cm for each color.

(Ink) Yellow triethylene glycol 7 parts by weight Hexanetriol 7 parts by weight Isopropyl alcohol 2.5 parts by weight Acetinol 0.4 parts by weight C.I. I. Direct Yellow 86 1.5 parts by weight Water 81.6 parts by weight 2. Magenta triethylene glycol 7 parts by weight Hexanetriol 7 parts by weight Isopropyl alcohol 1.5 parts by weight Acetinol 0.4 parts by weight C.I. I. Acid Red 289 1.5 parts by weight Water 82.3 parts by weight C. Cyan triethylene glycol 7 parts by weight Hexanetriol 7 parts by weight Isopropyl alcohol 1.5 parts by weight Acetinol 0.4 parts by weight I. Direct Blue 199 2.5 parts by weight Water 81.3 parts by weight The obtained color image had no stripes and uniformity. Further, the color characters and color line drawings were sharper and clearer than those obtained in Example 2.

Example 4 A color image was recorded in one pass under the same conditions as in Example 3 except that the recording property improving liquid used in Example 3 was changed to the following.

The surface tension of the recording property improving liquid is about 31 dyn /
cm.

(Recordability improving liquid) Glycerin 7 parts by weight Diethylene glycol 5 parts by weight Polyallylamine (15% aqueous solution) 24 parts by weight Acetic acid (10% aqueous solution) 3.51 parts by weight benzalkonium hydrochloride (51% aqueous solution) 0.96 Parts by weight triethylene glycol monobutyl ether 0.5 parts by weight acetylenol 0.05 parts by weight water remainder The obtained color image was uniform without streaks as in Example 3. However, the sharpness of black characters and black line images was slightly lower than that obtained in Example 3.

The following comparative examples are shown with respect to the above embodiments.

Comparative Example 1 A color image was recorded in one pass under the same conditions as in Example 1 except that the color ink used in Example 1 was changed to the following color ink.

The surface tension of each of the yellow, magenta and cyan inks was about 30 dyn / cm for each color.

(Ink) Yellow triethylene glycol 7 parts by weight Hexanetriol 7 parts by weight Isopropyl alcohol 2.5 parts by weight Acetinol 1.0 part by weight C.I. I. 1. Direct Yellow 86 1.5 parts by weight Water balance Magenta triethylene glycol 7 parts by weight Hexanetriol 7 parts by weight Isopropyl alcohol 1.5 parts by weight Acetinol 1.0 parts by weight C.I. I. Acid Red 289 1.5 parts by weight Water balance 3. C. Cyan triethylene glycol 7 parts by weight Hexanetriol 7 parts by weight Isopropyl alcohol 1.5 parts by weight Acetinol 1.0 parts by weight I. Direct Blue 199 2.5 parts by weight Water Remaining Feathering occurred in characters and line drawings in the obtained color image.

Comparative Example 2 A color image was recorded in one pass under the same conditions as in Example 1 except that the color ink used in Example 1 was changed to the following color ink.

The surface tension of the yellow, magenta, and cyan inks was about 44 dyn / cm for each color.

(Ink) Yellow triethylene glycol 7 parts by weight Hexanetriol 7 parts by weight Isopropyl alcohol 2.5 parts by weight C.I. I. 1. Direct Yellow 86 1.5 parts by weight Water balance B. Magenta triethylene glycol 7 parts by weight Hexanetriol 7 parts by weight isopropyl alcohol 1.5 parts by weight I. Acid Red 289 1.5 parts by weight Water balance 3. C. Cyan triethylene glycol 7 parts by weight Hexanetriol 7 parts by weight Isopropyl alcohol 1.5 parts by weight I. Direct Blue 199 2.5 parts by weight Water Remainder The obtained color image had noticeable streaks.

Comparative Example 3 A color image was recorded in one pass under the same conditions as in Example 3 except that the recording property improving liquid used in Example 3 was changed to the following recording property improving liquid.

The surface tension of the recording property improving liquid is about 28 for each color.
dyn / cm.

Diethylene glycol 20 parts by weight Polyallylamine hydrochloride 4 parts by weight Trade name: PAA-HCl-1L (manufactured by Nitto Boseki Co., Ltd.) Fluorine surfactant 0.001 part by weight (perfluoroalkyltrimethylammonium salt) Trade name: Surflon S-121 (manufactured by Asahi Glass Co., Ltd.) Water Remaining portion The obtained image was a low-color image with a solid portion having a darkened color.

(Examples 5) to (Example 8) The color inks used in Example 3 and the printability improving liquid were used.
As shown in Table 2, a color image was recorded by changing only the applied amount X1 of the recording property improving liquid, and thus changing the applied ratio X1 / X2. As the data for ejecting the printability improving liquid, a logical sum of data obtained by thinning out each color data is taken.

[0096]

[Table 2]

In Example 5, when the obtained image was sprinkled with water, the ink slightly blurred and the water resistance was slightly lowered.

In Examples 6 and 7, both image quality and water resistance were good.

In Example 8, although a substantially good image was obtained, slight beading occurred when recording was performed on plain paper having low permeability.

In Comparative Example 4, ink bleeding between different colors occurred, and the water resistance was further reduced.

In Comparative Example 5, beading was remarkable.

(Other Embodiments) In the above embodiment,
Since the ejection amount of the black ink for forming the black image is twice as large as that of the color ink, the example in which the recording property improving liquid applied to the black image is not thinned has been described, but the present invention is not limited to this. For example, when the applied amount of the black ink is the same as the ejected amount of the color ink, it may be thinned out in the same manner as the printability improving liquid applied to the color image. In such a case, for example, the image data of black, cyan, magenta, and yellow are thinned out by a predetermined amount, and then the logical sum is calculated.

Further, in Example 4, the sharpness of the characters and line images of the black image was slightly reduced. However, as shown in FIG. 4, the recording property improving liquid was discharged between the two black ink discharging heads 1k1 and 1k2. This problem can be solved by using a recording apparatus having the recording head 1s to be disposed. This will be described with reference to FIG.

FIG. 5 illustrates the process of forming a black image by the printer shown in FIG. FIG. 5 (a)
For example, a result of ejecting black ink by the recording heads 1k1 and 1k2 and ejecting the recording property improving liquid by the recording head 1s to 2 × 2 pixels is shown. In order to obtain the image of FIG. 5A, first, as shown in FIG. 5B, black ink is ejected by the recording head 1k1. Subsequently, as shown in FIG. 5C, a printability improving liquid is discharged from the printhead 1s to the same pixel. Finally, black ink is ejected from the recording head 1k2 to the same pixels as those shown in FIGS. 5B and 5C. Thus, the image formation using the black ink and the printability improving liquid is completed.

According to this configuration, since the liquid initially applied to the recording paper is an additional black ink having a high surface tension, the liquid penetrates the recording paper at a low speed, and is unlikely to cause feathering or bleeding. Therefore, even if a recording property improving liquid having a low surface tension and a high permeation rate to the recording paper is subsequently applied, feathering and bleeding are less likely to occur as compared with the fourth embodiment. Finally, black ink is applied again, but since it hardly penetrates the recording paper, the characters and line drawings of the obtained black image become sharp and clear.

In this configuration, since there are two print heads for discharging black ink, the discharge amount discharged from one print head is preferably the same as that for the color ink.
The amount of the recording property improving liquid applied to the black image may be the same as in the above-described embodiment.

(Others) It should be noted that the present invention includes a means (for example, an electrothermal converter or a laser beam) for generating thermal energy as energy used for discharging ink, particularly in an ink jet recording system. An excellent effect is obtained in a recording head and a recording apparatus of a type in which the state of ink is changed by the thermal energy. This is because according to such a method, it is possible to achieve higher density and higher definition of recording.

The typical configuration and principle are described in, for example, US Pat. Nos. 4,723,129 and 4,740.
It is preferable to use the basic principle disclosed in the specification of Japanese Patent No. 796. This method is a so-called on-demand type,
Although it can be applied to any type of continuous type, in particular, in the case of the on-demand type, it can be applied to a sheet holding liquid (ink) or an electrothermal converter arranged corresponding to the liquid path. By applying at least one drive signal corresponding to the recorded information and giving a rapid temperature rise exceeding the nucleate boiling, heat energy is generated in the electrothermal transducer, and film boiling occurs on the heat acting surface of the recording head. Liquid (ink) corresponding to this drive signal on a one-to-one basis.
This is effective because air bubbles inside can be formed. The liquid (ink) is ejected through the ejection opening by the growth and contraction of the bubble to form at least one droplet. When the drive signal is formed into a pulse shape, the growth and shrinkage of the bubble are performed immediately and appropriately, so that the ejection of a liquid (ink) having particularly excellent responsiveness can be achieved, which is more preferable. As the pulse-shaped drive signal, those described in US Pat. Nos. 4,463,359 and 4,345,262 are suitable. Further, if the conditions described in US Pat. No. 4,313,124 relating to the temperature rise rate of the heat acting surface are adopted, more excellent recording can be performed.

As the configuration of the recording head, in addition to the combination of the discharge port, the liquid path, and the electrothermal converter (linear liquid flow path or right-angled liquid flow path) as disclosed in the above-mentioned respective specifications, U.S. Pat. No. 4,558,333 and U.S. Pat. No. 44,558 which disclose a configuration in which a heat acting portion is arranged in a bending region.
A configuration using the specification of Japanese Patent No. 59600 is also included in the present invention. In addition, Japanese Unexamined Patent Application Publication No. 59-123670 discloses a configuration in which a common slit is used as a discharge portion of an electrothermal converter for a plurality of electrothermal converters, and an aperture for absorbing a pressure wave of thermal energy is provided. The effect of the present invention is effective even if the configuration is based on JP-A-59-138461, which discloses a configuration corresponding to a discharge unit. That is, according to the present invention, recording can be reliably and efficiently performed regardless of the form of the recording head.

Further, the present invention can be effectively applied to a full-line type recording head having a length corresponding to the maximum width of a recording medium on which a recording apparatus can record. Such a recording head may have a configuration that satisfies the length by a combination of a plurality of recording heads, or a configuration as one integrally formed recording head.

In addition, even in the case of the serial type as described above, the recording head fixed to the apparatus main body or the electric connection with the apparatus main body and the ink from the apparatus main body are attached to the apparatus main body by being attached to the apparatus main body. The present invention is also effective when a replaceable chip-type recording head that can be supplied or a cartridge-type recording head in which an ink tank is provided integrally with the recording head itself is used.

It is preferable to add a discharge recovery means for the print head, a preliminary auxiliary means, and the like as the structure of the printing apparatus of the present invention since the effects of the present invention can be further stabilized. If these are specifically mentioned, the recording head is heated using capping means, cleaning means, pressurizing or suction means, an electrothermal transducer, another heating element or a combination thereof. Pre-heating means for performing the pre-heating and pre-discharging means for performing the discharging other than the recording can be used.

The type and number of recording heads to be mounted are not limited to those provided only for one color ink, for example, and for a plurality of inks having different recording colors and densities. A plurality may be provided. That is, for example, the printing mode of the printing apparatus is not limited to a printing mode of only a mainstream color such as black, but may be any of integrally forming a printing head or a combination of a plurality of printing heads. The present invention is also very effective for an apparatus provided with at least one of the recording modes of full color by color mixture.

In addition, in the embodiments of the present invention described above, the ink is described as a liquid. However, an ink which solidifies at room temperature or lower and which softens or liquefies at room temperature may be used. In general, the ink jet method generally controls the temperature of the ink itself within a range of 30 ° C. or more and 70 ° C. or less to control the temperature so that the viscosity of the ink is in a stable ejection range. Sometimes, the ink may be in a liquid state. In addition, in order to positively prevent temperature rise due to thermal energy by using it as energy for changing the state of the ink from a solid state to a liquid state, or to prevent evaporation of the ink, the ink is solidified in a standing state and heated. May be used. In any case, the application of heat energy causes the ink to be liquefied by the application of the heat energy according to the recording signal and the liquid ink to be ejected, or to start solidifying when it reaches the recording medium. The present invention is also applicable to a case where an ink having a property of liquefying for the first time is used. In such a case, the ink
JP-A-54-56847 or JP-A-60-7
As described in Japanese Patent Publication No. 1260, it is also possible to adopt a form in which the sheet is opposed to the electrothermal converter in a state where it is held as a liquid or solid substance in the concave portion or through hole of the porous sheet. In the present invention, the most effective one for each of the above-mentioned inks is to execute the above-mentioned film boiling method.

In addition, the form of the ink jet recording apparatus of the present invention is not limited to those used as image output terminals of information processing equipment such as computers, copying apparatuses combined with readers and the like, and facsimile apparatuses having a transmission / reception function. It may take a form.

[0116]

As is apparent from the above description, according to the present invention, the surface tension of each of the color ink and the recording property improving liquid is set to an appropriate range, and the application of the recording property improving liquid to the color ink is performed. Since the amount is reduced, the permeability of the color ink can be made relatively low, so that even when a recording material such as plain paper having a relatively low permeability and a low permeability is used, the color developability is increased. And a clear image can be obtained. By using a recording property improving liquid having the same degree of permeability as that of the color ink, it is possible to prevent beading and connecting streaks and to make the permeability when mixed with the color ink appropriate.

As a result, it is possible to obtain both a color image excellent in uniformity of a solid portion and a clear color image. Further, it is possible to obtain a high-quality image in which black streaks and white streaks do not enter into a connection portion of each scan when printing in one pass.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a thinning method for generating application data of a recording property improving liquid.

FIG. 2 is a perspective view illustrating a schematic configuration of a printer used in an embodiment of the present invention.

FIG. 3 is a block diagram illustrating a control configuration of the printer.

FIG. 4 is a perspective view illustrating a schematic configuration of a printer used in another embodiment of the present invention.

FIG. 5 is a diagram illustrating a process of forming a black image by the printer shown in FIG.

[Explanation of symbols]

1y, 1m, 1c, 1S, 1K, 1K1, 1K2 Recording head 2 Carriage 7A, 7B Cartridge 301 System controller 304 Carriage motor 305 Paper feed motor 306 Host computer 308 Frame memory 309 Print buffer 310 Print control unit

Claims (22)

[Claims] 1. An ink jet recording method for forming an image by applying a color ink and a recording property improving liquid for improving the recording property of the color ink to a recording material, wherein the surface tension γ1 of the color ink is 30 dyn / cm <
γ1 ≦ 40 dyn / cm, the surface tension γ2 of the recording-enhancing liquid is 30 dyn / cm <γ2 ≦ 40 dyn / cm, and the applied amount X1 of the recording-enhancing liquid in at least a partial region of the image; An ink-jet recording method, wherein the amount of ink X2 applied to some areas satisfies X1 / X2 <1. 2. The ink jet recording method according to claim 1, wherein the recording property improving liquid contains a compound that insolubilizes or aggregates a coloring material contained in the ink. 3. The ink jet recording method according to claim 1, wherein the recording property improving liquid is applied before applying the color ink. 4. The ink jet recording method according to claim 1, wherein the color ink is any one of cyan, magenta, and yellow, or a combination of these inks. 5. The method according to claim 1, wherein the surface tension γ1 is 31 dyn / cm ≦
5. The ink jet recording method according to claim 1, wherein γ1 ≦ 39 dyn / cm. 6. The surface tension γ1 is 32 dyn / cm ≦
5. The ink jet recording method according to claim 1, wherein γ1 ≦ 36 dyn / cm. 7. The method according to claim 6, wherein the surface tension γ2 is less than 30 dyn / cm.
7. The ink jet recording method according to claim 1, wherein γ2 ≦ 39 dyn / cm. 8. The surface tension γ2 is not more than 30 dyn / cm.
7. The ink jet recording method according to claim 1, wherein γ2 ≦ 36 dyn / cm. 9. The method according to claim 1, wherein X1 / X2 is 0.25 ≦ X1 / X.
9. The ink jet recording method according to claim 1, wherein 2 ≦ 0.67 is satisfied. 10. The X1 / X2 is set as follows: 0.25 ≦ X1 ≦
9. The ink jet recording method according to claim 1, wherein 0.50 is satisfied. 11. The X1 / X2 may be 0.33 ≦ X1 /
9. The inkjet recording method according to claim 1, wherein X2 ≦ 0.50 is satisfied. 12. The application amount X1 of the recording-enhancing liquid is set by using modification data obtained by thinning a predetermined amount from image data as data for applying the recording-enhancing liquid. 12. The inkjet recording method according to any one of 1 to 11. 13. A logical sum of modification data for each color obtained by thinning out a predetermined amount from the image data of each color of yellow, magenta, and cyan is used as data for discharging a printability improving liquid. 13. The inkjet recording method according to item 12. 14. The ink jet recording method according to claim 13, wherein the predetermined amount of the thinning is different for each of yellow, magenta, and cyan. 15. An ink and a recording property improving liquid are applied by ejecting an ink and a recording property improving liquid by a recording head, and the ejection amount per droplet of the recording property improving liquid is adjusted by the ink. 12. The ink jet recording method according to claim 1, wherein the application amount X1 of the recording property improving liquid is set by setting the ejection amount per droplet to be smaller than the ejection amount per droplet. 16. The ink-jet recording method according to claim 15, wherein the recording head includes a thermal energy generating unit that generates thermal energy used to discharge the ink or the recording property improving liquid. Recording method. 17. The recording property improving liquid contains a cationic substance comprising a low molecular component and a high molecular component, and the dye contained in the ink comprises an anionic substance. Item 17. An ink jet recording method according to any one of Items 1 to 16. 18. The recording-improvement liquid contains a cationic substance composed of a low-molecular component and a high-molecular component, and the ink contains an anionic dye or contains at least an anionic compound and a pigment. 17. The ink jet recording method according to claim 1, comprising: 19. A recording head for discharging color ink and a recording head for discharging a recording property improving liquid for improving the recording property of the color ink, and discharging the color ink and the recording property improving liquid onto a recording material to form an image. An ink jet recording apparatus for recording, wherein the surface tension γ1 of the color ink is 30 dyn / cm <
γ1 ≦ 40 dyn / cm, the surface tension γ2 of the recording-enhancing liquid is 30 dyn / cm <γ2 ≦ 40 dyn / cm, and the applied amount X1 of the recording-enhancing liquid in at least a partial region of the image; It has a means for controlling a recording head for discharging the color ink and a recording head for discharging the recording quality improving liquid so that the ink amount X2 applied to some areas satisfies X1 / X2 <1. Ink jet recording device. 20. The ink jet recording apparatus according to claim 19, wherein the recording head includes a thermal energy generating unit that generates thermal energy used to discharge the ink or the recording property improving liquid. Recording device. 21. A recording head for discharging color ink and a recording head for discharging a recording property improving liquid for improving the recording property of the color ink, and discharging the color ink and the recording property improving liquid onto a recording material to form an image. An ink cartridge used in an ink jet recording apparatus for recording, wherein a surface tension γ1 is 30 dyn / cm <γ1 ≦ 40 dyn /
An ink cartridge characterized by storing color ink of cm. 22. A recording head which discharges color ink and a recording head which discharges a recording property improving liquid for improving the recording property of the color ink, and discharges the color ink and the recording property improving liquid onto a recording material to form an image. A cartridge for a recording property improving liquid used in an ink jet recording apparatus for recording, wherein the surface tension γ2 is 30 dyn / cm <γ2 ≦ 40
A recording-improvement liquid cartridge containing a dyn / cm recording-improvement liquid.