JPH08216396A - Ink jet printing device and ink jet printing method - Google Patents

Abstract

PURPOSE: To obtain a favorable gradational high picture quality picture image by a method wherein many-valued data for discharging a printability improving liquid are produced so as to overlappingly give ink and the printability improving liquid on a medium on the basis of the discharging data corresponding to the density data, the value of the density of which is at least much larger among those of discharging data. CONSTITUTION: Inputted picture signals are dissolved in chrominance signals Y1, M1 and C1 and applied with colortreatment so as to form image density signals Y3, M3, C3 and K3 and then corrected into Y4, M4, C4 and K4 at the steps 602-604 in order to form image data of respective colors Y51, Y52, M51, M52, C51, C52, K51 and K52 at a shading directing circuit. Respective shaded image data enters a YMCK data forming circuit so as to form data Y6, M6, K6, C6 and S6 for discharging ink from heads. When image data show 'deep', a printability improving liquid is discharged together with ink to the image.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet printing method and an ink jet printing apparatus, and more particularly to an ink jet printing method and an ink jet printing apparatus for applying an ink and a liquid for improving printability onto a print medium. is there.

The present invention is applicable to not only general paper which is usually used, but also cloth, leather, non-woven fabric, OHP paper, etc., and all devices for applying ink to a print medium such as metal. Examples of typical applicable equipment include office equipment such as printers, copying machines, and facsimiles, and industrial production equipment.

[0003]

2. Description of the Related Art Conventionally, the ink jet printing system has been widely used in printers, copying machines, etc. because of its low noise, low running cost, miniaturization of apparatus, and easy colorization. In such a printing device,
As one configuration for improving the quality of a printed image, a high density of ink ejection ports is adopted, which enables printing of a particularly high resolution image.

However, there is a limit to increasing the density of ink ejection ports, and on the other hand, such an ink jet printing method is one in which an ink dot is formed or not in one pixel, that is, a so-called digital printing method. Is. Therefore, it is relatively difficult to express the gradation, and in particular, in the highlight portion of the image, individual ink dots are conspicuous, and the image may have a so-called graininess.

As one configuration for solving this problem,
Conventionally, a method has been proposed in which the amount of ejected ink is reduced and ink is ejected a plurality of times on the same pixel on a print medium according to density data to form dots. However, there is a limit in reducing the amount of ejected ink, and since this method performs overlapping printing, there is a problem in that the printing speed is reduced.

As another method for improving the image quality without increasing the density of the ink ejection ports, for example, dark and light inks of similar colors having different dye densities are used to make the dots of the ink inconspicuous and increase the speed. A method for achieving this is also proposed. However, since this method uses a plurality of types of ink of similar colors, the configuration for that causes an increase in the size and cost of the device, and when the usage amounts of dark ink and light ink cannot be balanced. There was also a problem that only one of them was consumed soon.

[0007]

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to provide a high gradation with good gradation without preparing plural kinds of inks. An object of the present invention is to provide an inkjet printing apparatus and an inkjet printing method that can obtain a high quality image.

[0008]

Therefore, according to the present invention,
In an inkjet printing apparatus that performs printing by ejecting ink and a printability improving liquid applied to a print medium to improve printability in inkjet printing, multi-value density data is generated based on image data. Printability improving liquid ejection data generation for generating data for ejecting the printability improving liquid from at least multi-valued data generating means and density data having a larger value among the multi-valued concentration data generated by the multi-valued data generating means Means, ejection data generation means for generating data for ejecting ink based on multi-valued density data generated by the multi-valued data generation means, ejection data generated by the printability improving liquid ejection data generation means, and Of the discharge data generated by the discharge data generating means, a value having a value larger than at least And an ejection control unit that applies the ink ejected from the ink ejection unit and the printability improving liquid ejected from the liquid ejection unit onto the print medium in an overlapping manner based on the ejection data corresponding to the density data. Characterize.

Further, in an ink jet printing method in which ink is applied to a print medium to perform printing, an ink ejecting section for ejecting ink and a printability improvement imparted to a print medium in order to improve printability in ink jet printing. A liquid ejecting unit for ejecting liquid is prepared, and at least when printing with a higher density, the ink ejected from the ink ejecting unit and the printability improving liquid ejected from the liquid ejecting head are used. Print by adding it on the print medium.
It is characterized by having each step.

[0010]

According to the above construction, when printing is performed at a density higher than at least a certain density, the printing can be performed by superposing the ink and the printability improving liquid. It is possible to increase the density of the printed portion due to the influence of the improving liquid on the ink.

[0011]

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

(Embodiment 1) FIG. 1 is a perspective view showing an outline of an ink jet printing apparatus according to an embodiment of the present invention.

In the ink jet printing apparatus 100, the carriage 101 slidably engages with two guide shafts 104 and 105 extending in parallel with each other. As a result, the carriage 101 can be moved along the guide shafts 104 and 105 by a driving motor and a driving force transmission mechanism (not shown) such as a belt that transmits the driving force of the driving motor. The carriage 101 is equipped with an inkjet unit 103 having an inkjet head and an ink tank as an ink container that stores ink used in this head.

The ink jet unit 103 comprises a head for ejecting ink and a treatment liquid as a printability improving liquid, and a tank as a container for accommodating the ink or treatment liquid supplied thereto. That is, each ink of four colors of black (Bk), cyan (C), magenta (M) and yellow (Y) and five heads for respectively ejecting the treatment liquid and tanks provided corresponding to each of these heads are ejected. Is the inkjet unit 10
3 is mounted on the carriage 101. Each head and the tank are detachable from each other, and are provided so that only the tank can be exchanged for each ink color or the like as necessary when the ink or treatment liquid in the tank is used up. Of course, only the head can be replaced if necessary. The structure for attaching and detaching the head and the tank is not limited to the above example, and it goes without saying that the head and the tank may be integrally molded.

Further, the improvement of the printability of the treatment liquid is, as an example thereof will be described later, improving the image quality such as the density, the saturation, the sharpness degree of the edge portion, the dot diameter and the like, and fixing the ink. To improve
It includes improving weather resistance such as water resistance and light resistance, that is, image storability.

The paper 106 as a print medium is inserted from an insertion port 111 provided at the front end of the apparatus, the conveyance direction is finally reversed, and the paper 106 is conveyed to the lower part of the moving area of the carriage 101 by the feed roller 109. It As a result, the head mounted on the carriage 101 prints on the print area on the paper 106 supported by the platen 108 as the head moves.

As described above, printing is performed on the entire paper 106 by alternately repeating the printing of the width corresponding to the width of the ejection opening array of the head and the feeding of the paper 106 according to the movement of the carriage 101, and the paper 106 is printed. Is discharged to the front of the device.

At the left end of the movable area of the carriage 101, there is provided a recovery system unit 110 which can face the heads on the carriage 101 and the lower portion thereof so that the ejection ports of the heads can be used when recording is not performed. It is possible to perform an operation of capping, an operation of sucking ink from the ejection port of each head, and the like. The predetermined position of the left end is set as the home position of the head.

On the other hand, at the right end of the apparatus, an operation section 107 having a switch and a display element is provided. The switches here are used when turning on / off the power of the apparatus and setting various print modes, and the display element plays a role of displaying various states of the apparatus.

FIG. 2 is a schematic perspective view showing the ink jet unit 103 described with reference to FIG. This configuration shows a configuration in which the tanks for the black, cyan, magenta, and yellow inks and the treatment liquid can be independently replaced as described above.

That is, a head case 102 for removably mounting each head on the carriage 101.
And Bk tank 20K, C tank 20C, M tank 20M, Y tank 20Y, and processing liquid tank 2
1 is installed. In the head case 102, Bk, C,
Heads 30 for ejecting M and Y inks, respectively
K, 30C, 30M, 30Y (not shown) and a head 31 (not shown) for ejecting the processing liquid are mounted. Each head has 160 ejection ports, and 40 ng of ink is ejected from each ejection port. Each tank is connected to the head via a connecting portion and supplies ink or treatment liquid.

Regarding the structure of the tank, for example, the processing liquid and the tank of Bk may have an integrated structure, or the tanks of C, M, and Y may have an integrated structure, depending on the amount used. Is also good.

FIG. 3 is a block diagram showing the control arrangement of the ink jet printing apparatus of the embodiment.

Character and image data to be printed (hereinafter referred to as image data) is input from the host computer to the reception buffer 401 of the printing apparatus 100. Further, the data for confirming whether the data is correctly transferred and the data for notifying the operating state of the printing apparatus are transferred from the printing apparatus to the host computer. The data input to the reception buffer 401 is the control unit 4 having a CPU.
Under the control of No. 02, it is transferred to the RAM type memory unit 403 and temporarily stored. Mechanical control unit 404
Is a carriage 101 according to a command from the control unit 402.
A mechanical unit 4 such as a carriage motor or a line feed motor, which serves as a power source of the feed roller 109 (see FIG. 1).
Drive 05. Sensor / SW control unit 406
Is a sensor / S consisting of various sensors and SW (switch)
The signal from the W unit 407 is sent to the control unit 402. The display element control unit 408 controls the display of the display element unit 409 including the LEDs of the display panel group, the liquid crystal display element, and the like according to a command from the control unit 402. The head controller 410 receives each head 30 in response to a command from the controller 402.
K, 30C, 30M, 30Y and 31 are individually controlled.
In addition, temperature information indicating the state of each head is transmitted to the read control unit 402.

The control section 402 comprises an image processing section for performing image processing which will be described later with reference to FIGS.

FIG. 4 is a diagram showing the contents of the distribution table for light and shade in the multi-valued processing according to one embodiment of the present invention. That is, this figure shows the relationship between the density input value and the output value for each pixel of image data, and the schematic print pixel density represented by the output value. FIG. 5 is a flow chart showing the procedure of this multi-value quantization process.

First, the input value (density value) of the input signal (image data) is determined for each pixel (step S in FIG. 5).
51). Next, the table having the contents shown in FIG. 4 is accessed by the address corresponding to the determined input value, and converted (sorted) into any of the three-stage output values,
The output value is stored in the memory 403. That is, if the input value of the target pixel is 0 ≦ x <96, the output value is set to 0 according to FIG. 4 (steps S52 and S53). In this case, ejection is not performed. If the input value is 96 ≦ x <224, the output value is set to 192 (light) and stored in the memory (steps S54 and S55). If the input value is 224 ≦ x <256, the output value is set to 255 (dark) and is stored in the memory (steps S56 and S57).

Since the density value obtained by the above multi-valued processing has an error with respect to the actual input,
The image density in the vicinity of the target pixel is saved by distributing this error to the pixels in the vicinity of the target pixel (step S5).
9). That is, in this example, the error diffusion method is used to perform multi-value quantization. The error is distributed at a predetermined distribution rate. As a result, the value of the neighboring pixel to be processed next to the pixel of interest becomes the new input value by adding the error of the pixel of interest in addition to the original input value. The new input value is again shaded by the shade distribution table according to the relationship of FIG.

As an example, the input value of a certain pixel of interest is 1
In the case of 60, the output shown in FIG. 5 becomes “light” at 192. At this time, the error is +32, which is the difference between 192 and 160. This error +32 is distributed to neighboring pixels. As a result, in the neighboring pixels, a value obtained by adding the distributed error value to the original input value becomes a new input value.

It should be noted that the above-mentioned configuration shows one example of the density distribution table, and it goes without saying that an optimum threshold value is set according to the type of ink or treatment liquid, and a density distribution table corresponding to this is provided.

Further, in order to increase the density, when printing is performed by overlapping the same color ink on the same pixel a plurality of times, a new multi-value quantization table is provided.

FIG. 6 is a block diagram showing the structure of image processing including the above-mentioned multi-valued processing along the data flow.

The input image signal is decomposed into color signals of yellow Y1, magenta M1, and cyan C1, and color processing is performed by a masking circuit 602 and an undercolor removal (UCR) / black generation circuit 603, respectively, and yellow and magenta are obtained. , Cyan new image density signals Y3, M3, C3, K3 are generated. Further, γ correction is performed by the γ correction circuit 604, whereby the image density signals Y4, M4, C4, K4
Is generated. Further, by the method described above by the density distribution circuit using the above table, the light and dark image data Y51 and Y52 of yellow, the light and dark image data M51 and M52 of magenta, and the light and dark image data C51 of cyan. , C52, and black and light image data K51 and K52 are generated.

Each grayscale image data enters a YMCKS data generation circuit and generates data Y6, M6, C6, K6, S6 for ejecting ink from the head.

Here, the discharge data Y6 is Y51 and Y52.
It is generated by taking the logical OR of Similarly, M6
C6 and K6 are also M51 and M52, C51 and C52, K51
And K52 are respectively generated by logical OR. Further, S6 is the ejection data of the treatment liquid, which is generated by taking the logical OR of the dark color data Y52, M52, C52, K52 of each color. That is, when the image data represents “dark” shown in FIG. 4 and the like, the treatment liquid is ejected to the pixel together with the ink.

FIG. 7 is a schematic view showing an example of a grayscale image by ink dots formed by the above method.

As is clear from the figure, the ink of the color corresponding to the pixel determined to be "dark" and the pixel determined to be "light" are ejected to the pixel corresponding to the ejection data, and each color is ejected. The processing liquid is further ejected to the pixels determined to be “dark” in.

Here, which of the ink and the treatment liquid is ejected first to a certain pixel is determined by the arrangement order of the heads and the scanning direction.

FIGS. 8A and 8B are schematic diagrams showing a state where the ink dots that do not use the treatment liquid and the ink dots that use the ink penetrate into the paper as described above.

Since the ink 60 is generally a liquid, it penetrates deep into the fibers of the paper after contacting the paper 106. Therefore, the amount of coloring material remaining on the surface is small, and the density is relatively low (light). On the other hand, when the treatment liquid 62 and the ink are applied to the same pixel of the print medium, the ink is applied to the paper 10.
Immediately after reaching 6, the treatment solution is contacted and insolubilized. Since the insolubilized coloring material does not penetrate deep into the paper, a large amount of coloring material remains on the surface and the density becomes high (dark). In addition to this, the insolubilized component does not dissolve in water, so that water resistance is also imparted.
The treatment liquid is preferably applied before the ink.

Inks and treatment liquids that can be used in this embodiment are as follows.

Y ink Glycerin 5.0% by weight Thiodiglycol 5.0% by weight Urea 5.0% by weight Isopropyl alcohol 4.0% by weight Dye C.I. I. Direct Yellow 142 2.0% by weight Water 79.0% by weight M ink Glycerin 5.0% by weight Thiodiglycol 5.0% by weight Urea 5.0% by weight Isopropyl alcohol 4.0% by weight Dye C.I. I. Acid Red 289 2.5% by weight Water 78.5% by weight C ink Glycerin 5.0% by weight Thiodiglycol 5.0% by weight Urea 5.0% by weight Isopropyl alcohol 4.0% by weight Dye C. I. Direct Blue 199 2.5 wt% Water 78.5 wt% Bk ink Glycerin 5.0 wt% Thiodiglycol 5.0 wt% Urea 5.0 wt% Isopropyl alcohol 4.0 wt% Dye Food Black 2 3.0 Weight% Water 78.0 weight% Treatment liquid Polyallylamine hydrochloride 5.0 weight% Benzalkonium chloride 1.0 weight% Diethylene glycol 10.0 weight% Acetylenol EH (Kawaken Chemical) 0.5 weight% Water 83.5 In the mixing of the treatment liquid (liquid composition) and the ink shown by weight% or more, respectively, in the present invention, as a result of mixing the treatment liquid and the ink on the printing material or at the position where the ink penetrates, the reaction In the first step, among the cationic substances contained in the treatment liquid, low molecular weight components or cationic oligomers and The water-soluble dye having an anionic group used in the ink or the anionic compound used in the pigment ink causes an association by an ionic interaction, and instantaneously separates from the solution phase. As a result, dispersion destruction occurs in the pigment ink, and pigment aggregates are formed.

Next, in the second step of the reaction, the aggregate of the dye and the low molecular weight cationic substance or cationic oligomer or the aggregate of the pigment is adsorbed by the polymer component contained in the treatment liquid. In addition, the size of aggregates of dyes or aggregates of pigments generated by association becomes even larger, making it difficult for the aggregates to enter into the gaps between fibers of the print material, and as a result, only the liquid portion that is solid-liquid separated into the recording paper. By soaking in, both print quality and fixability are achieved. At the same time, the low molecular weight component of the cationic substance generated by the mechanism as described above or a cationic oligomer, an aggregate formed of an anionic dye and a cationic substance or an aggregate of the pigment has a high viscosity,
Since the liquid medium does not move with the movement of the liquid medium, even if adjacent ink dots are formed of different color inks as in the case of full-color image formation, they do not mix with each other, and bleeding does not occur. Also,
The aggregates are essentially water insoluble and the water resistance of the formed image is perfect. Further, it also has the effect of improving the light fastness of the image formed by the shielding effect of the polymer.

As the insolubilization or agglomeration used in the present specification, one example thereof is the phenomenon of the first stage only, and another example is a phenomenon including both the first stage and the second stage.

In the above example, the dye is used as the color material of each ink. However, the color material is not limited to this. For example, a pigment is used as the color material, or a dye and a pigment are mixed. It may be one or the like.

The following may be mentioned as an example of the pigment ink which causes aggregation when mixed with the above-mentioned treatment liquid. That is, as described below, it is possible to obtain yellow, magenta, cyan, and black color inks Y2, M2, C2, and K2 each containing a pigment and an anionic compound.

Black ink K2 anionic polymer P-1 (styrene-methacrylic acid-ethyl acrylate, acid value 400, weight average molecular weight 6,0
00, an aqueous solution with a solid content of 20%, a neutralizing agent: potassium hydroxide) was used as a dispersant, and the following materials were charged into a batch type vertical sand mill (made by AIMEX) and 1 mm diameter glass beads were filled as a medium. The dispersion treatment was performed for 3 hours while cooling with water. The viscosity after dispersion was 9 cps and the pH was 10.0. This dispersion was centrifuged to remove coarse particles, to prepare a carbon black dispersion having a weight average particle diameter of 100 nm.

(Composition of carbon black dispersion) -P-1 aqueous solution (solid content 20%) 40 parts-Carbon black Mogul L (manufactured by Cablack) 24 parts-Glycerin 15 parts-Ethylene glycol monobutyl ether 0.5 parts- Isopropyl alcohol 3 parts water 135 parts Next, the dispersion obtained above was sufficiently dispersed to obtain a black ink K2 for ink jet containing a pigment. The solid content of the final preparation was about 10%.

Yellow ink Y2 anionic polymer P-2 (styrene-acrylic acid-methyl methacrylate, acid value 280, weight average molecular weight 1
1,000%, an aqueous solution with a solid content of 20%, a neutralizing agent: diethanolamine) was used as a dispersant, and the following materials were used to carry out a dispersion treatment in the same manner as in the production of the black ink K2. A 103 nm yellow color dispersion was prepared.

(Composition of yellow dispersion) P-2 aqueous solution (solid content 20%) 35 parts C.I. I. Pigment Yellow 180 24 parts (Novapalm Yellow PH-G, manufactured by Hoechst) -Triethylene glycol 10 parts-Diethylene glycol 10 parts-Ethylene glycol monobutyl ether 1.0 part-Isopropyl alcohol 0.5 parts-Water 135 parts Obtained as above The yellow dispersion was sufficiently diffused to obtain an inkjet yellow ink Y2 containing a pigment. The solid content of the final preparation was about 10%.

Cyan Ink C2 Using the anionic polymer P-1 used in the preparation of the black ink K2 as a dispersant, the following materials were used to carry out the same dispersion treatment as in the case of the carbon black dispersion described above. Then, a cyan color dispersion having a weight average particle diameter of 120 nm was produced.

(Composition of cyan color dispersion) P-1 aqueous solution (solid content 20%) 30 parts C.I. I. Pigment Blue 15: 3 24 parts (Fast Gemble-FGF, Dainippon Ink and Chemicals) ・ Glycerin 15 parts ・ Diethylene glycol monobutyl ether 0.5 parts ・ Isopropyl alcohol 3 parts ・ Water 135 parts Cyan color dispersion obtained above Was sufficiently stirred to obtain a cyan ink C2 for ink jet containing a pigment. The solid content of the final preparation was about 9.6%.

The same dispersion treatment as in the case of the carbon black dispersion described above was performed using the anionic polymer P-1 used in the preparation of the magenta ink M2 black ink K2 as a dispersant and the following materials. Then, a magenta color dispersion having a weight average particle diameter of 115 nm was produced.

(Composition of magenta color dispersion) P-1 aqueous solution (solid content 20%) 20 parts C.I. I. Pigment Red 122 (Dainippon Ink and Chemicals Inc.) 24 parts-Glycerin 15 parts-Isopropyl alcohol 3 parts-Water 135 parts Magenta ink for ink jet containing a pigment by sufficiently diffusing the magenta color dispersion obtained above. M2
I got The solid content of the final preparation was about 9.2%.

(Embodiment 2) In the case of adopting a printing method in which the same color ink is superposed on the same pixel a plurality of times with a single head, there is a general problem that the printing speed is lowered. In this embodiment, a method for realizing higher density printing without lowering the printing speed will be described.

FIG. 9 schematically shows the ejection port surface (the surface facing the print medium) of the head group 120 according to this embodiment. The head group 120 includes two Bk heads 30.
K1, 30K2, cyan, magenta, and yellow heads 30C, 30M, 30Y, and a processing liquid head 31. The processing liquid head 31 is located between the two black recording heads 30K1 and 30K2. Each head has 160 ejection ports, and 40 ng of ink or treatment liquid is ejected from each ejection port.

FIG. 10 is a block diagram showing a configuration for data generation when the head group 120 is used.

Since there are two heads for ejecting black ink, it is possible to express pixels with higher density. Therefore, only black is binarized by using an appropriate gradation distribution table.
Of these, the treatment liquid is ejected to the pixel with the highest concentration (K53), and black ink is ejected from each of the two Bk heads to form a dot with 80 ng of black ink. The pixel (K51) having the lowest density is recorded with 40 ng of black ink ejected from the Bk head 30K1 or 30K2. Bk head 30K for the pixel (K52) of intermediate density
Dots are formed by ejecting the treatment liquid together with 40 ng of black ink ejected from 1 or 30K2.
The Bk head is preferably used in consideration of the life of the user so as not to cause deviation. Cyan, magenta, and yellow are ternarized as in the first embodiment.

The processing liquid data S6 is YMC dark color data Y52, M52, C52 and K dark color data K53.
And the intermediate color data K52 are logically ORed.

(Third Embodiment) In the first and second embodiments, the amount of ink ejected from the ink ejection head is constant at 40 ng. In this embodiment, an example of changing the ink ejection amount is shown.

By changing the amount of ink, it is possible to express more gradations. The ink ejection volume is
It can be changed by a conventionally known method such as providing a plurality of heating elements for generating thermal energy for ejecting ink.

The ink ejection head applicable to this embodiment has two heating elements for generating thermal energy, and the amount of ink ejected from the ink ejection head is 1.
It can be varied in 3 stages of 5 ng, 25 ng and 40 ng. When printing is performed with each ink ejection amount, it is possible to express the density in four steps. Further, "no printing", "printing only with 15 ng of ink", "processing liquid with 15 ng of ink" depending on whether or not the treatment liquid is applied,
It is possible to express the density in seven steps: “print with 25 ng ink only”, “treatment liquid with 25 ng ink”, “print with 40 ng ink only”, and “treatment liquid with 40 ng ink”. In this case, it is needless to say that it has an optimum density distribution table according to the type of each ink and treatment liquid.

As described above, in the present embodiment, it is possible to express the gradation in seven steps. However, the 7-step gradation process takes time to process, and there is a risk that the printing speed is delayed. In that case, of the 7 possible levels,
It is also possible to select the optimum density in about three stages and perform quaternarization processing. The three levels of density suitable for gradation expression are, for example, “40n
Treatment liquid for G ink ”,“ 25 ng ink ”,“ 15
In the case of a combination of “ng of ink and treatment liquid”, the treatment liquid is applied to the pixel having the highest density and the pixel having a two-step lower density than that of the four-valued data.

(Embodiment 4) In the above Embodiments 1, 2, and 3, an example is shown in which only one type of ink is provided for each color. However, depending on the combination of the ink and the treatment liquid, the desired gradation may not be obtained only by the presence or absence of the treatment liquid. In that case,
For cyan, magenta, and yellow, it is effective to use a plurality of types of inks having different densities, and to express gradation with or without the treatment liquid only for black that does not require high gradation.

FIG. 11A is a perspective view of an ink jet head unit applicable to this embodiment, and FIG.
A schematic view of the configuration of the tank is shown in (B).

The processing liquid and the black ink are stored in tanks 71 and 70K, respectively. Cyan, magenta, and yellow are provided with three types of ink of similar colors with different densities, and are stored in ink tanks 70C, 70M, and 70Y. The cyan ink tank 70C is composed of three small tanks 70C1, 70C2, and 70C3, and contains dark, medium, and light density inks, respectively. The ink tanks 70M and 70Y for magenta and yellow also have the same structure. Each head has 160 ejection ports, and about 40 ng of ink is ejected from each ejection port. The cyan, magenta, and yellow heads are separated by 8 discharge ports, and 4
Each of the eight ejection ports is partitioned so as to eject the ink of high density, medium density, and light density. The ink tank is connected to the head via a connecting portion, and supplies ink and treatment liquid to the ejection port. The heads for treatment liquid and black ink have a single connection, but the heads for cyan, magenta, and yellow inks are dark, medium, and
It has three connections for each light ink.

The black ink is ternarized in the same manner as in the first embodiment. The treatment liquid and ink are discharged to the pixel having the highest density, and only the ink is discharged to the pixel having a relatively low density, and the pixel having the lowest density is discharged. Do not discharge. Cyan, magenta, and yellow are quaternarized according to an appropriate gradation distribution table. The darkest ink is printed for the highest density pixel, the medium density ink is used for the relatively low density pixel, and the light density ink is used for the lower density pixel.

Further, when the treatment liquid is applied to the same pixel as the ink on the print medium, the density of the pixel is increased. Therefore, the gradation expression of seven steps is performed depending on whether the treatment liquid is applied to each of the dark, medium and light inks. Is possible. However, when it is not necessary to express 7 levels of gradation, the optimum 3
It is advisable to select a grade level and use a quaternary gradation surface.

In this embodiment, cyan, magenta, and yellow inks have three types of inks of the same color with different densities in three steps.
The number of types may be increased, or the number of types may be increased for higher gradation.

(Embodiment 5) When the minimum area unit of one dot when forming an image is defined as a dot area, dot diameter modulation, multiple printing (multi-droplet), and two printing are performed within one dot area. It is possible to express gradation by a method of varying print density, such as dark and light recording using dark and light inks with density higher than the density.

In this embodiment, a piezo type ink jet head using a laminated piezoelectric element is used, and the gradation expression by dot diameter modulation by the driving voltage of the head is used as the original gradation, and the same printing method as this gradation printing is used. Prior to printing, the same liquid as the treatment liquid used in Example 1 was applied to the dot areas expressing each gradation to obtain sub gradation.

Driving voltage Original gradation (O.D.) Sub gradation (O.D.) 0V 0 ^* 0 20V 0.5 ^* 0.6 30V 0.7 ^* 0.9 ^* 40V 1.0 1. 2 ^* 50V 1.3 1.5 ^{* In the} present embodiment, in order to form a natural image, the number of gradations in one dot area is changed from 5 steps of the original gradation number to 6 steps. The original gradation and the sub gradation were combined and the mark * was selected.

Furthermore, the dither method, the pixel matrix method,
An image closer to a higher-quality natural image can be obtained by using it together with a gradation expression method based on an area or a dot interval (distance between dots) such as an error diffusion method.

(Others) The present invention is provided with a means (for example, an electrothermal converter or a laser beam) for generating thermal energy as energy used for ejecting ink, particularly in the ink jet recording system. The present invention brings about excellent effects in a recording head and a recording apparatus of the type in which the state of ink is changed by the heat energy. This is because such a system can achieve high density recording and high definition recording.

Regarding its typical structure and principle, see, for example, US Pat. Nos. 4,723,129 and 4740.
What is done using the basic principles disclosed in 796 is preferred. This method is a so-called on-demand type,
It can be applied to any of the continuous type, but especially in the case of the on-demand type, it can be applied to the sheet holding the liquid (ink) or the electrothermal converter arranged corresponding to the liquid path. By applying at least one drive signal corresponding to the recording information and giving a rapid temperature rise exceeding nucleate boiling, heat energy is generated in the electrothermal converter, and film boiling is caused on the heat acting surface of the recording head. Liquid (ink) corresponding to this drive signal in a one-to-one correspondence
It is effective because bubbles can be formed inside. The liquid (ink) is ejected through the ejection opening by the growth and contraction of the bubble to form at least one droplet. It is more preferable to make this drive signal into a pulse shape because bubbles can be immediately and appropriately grown and contracted, so that liquid (ink) ejection with excellent responsiveness can be achieved. As the pulse-shaped drive signal, those described in US Pat. Nos. 4,463,359 and 4,345,262 are suitable. If the conditions described in US Pat. No. 4,313,124 of the invention relating to the rate of temperature rise on the heat acting surface are adopted, more excellent recording can be performed.

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

Furthermore, 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 which can be recorded by the recording apparatus. 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 recording head integrally formed.

In addition, even in the case of the serial type as in the above example, the recording head fixed to the apparatus main body, or by being attached to the apparatus main body, electrical connection with the apparatus main body and ink from 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 integrally provided in the recording head itself is used.

Further, it is preferable to add recovery means for the recording head, preliminary auxiliary means, etc., which are provided in the present invention as a configuration of the recording apparatus, because the effects of the present invention can be further stabilized. . Specific examples thereof include capping means for the recording head, cleaning means, pressurizing or suctioning means, electrothermal converter or other heating element or preheating means by a combination thereof, It is also effective to perform stable recording by performing a preliminary discharge mode in which discharge is performed separately from recording.

Regarding the type and number of recording heads to be mounted, for example, only one is provided corresponding to a single color ink, or a plurality of inks having different recording colors and densities are supported. A plurality of pieces may be provided. That is, for example, the recording mode of the recording apparatus is not limited to the recording mode of only the mainstream color such as black, but it may be either the recording head is integrally formed or a plurality of combinations may be used. The present invention is also extremely effective for a device provided with at least one of full colors by color mixing.

In addition, in the above-described embodiments of the present invention, the ink is described as a liquid, but it is an ink that solidifies at room temperature or lower and that softens or liquefies at room temperature, or an ink jet system. In general, the temperature of the ink itself is adjusted within the range of 30 ° C. or higher and 70 ° C. or lower to control the temperature of the ink so that the viscosity of the ink is within the stable ejection range. Anything can be used. In addition, the temperature rise due to thermal energy is positively prevented by using it as the energy for changing the state of the ink from the solid state to the liquid state, or the ink that solidifies in the standing state is used for the purpose of preventing evaporation of the ink. However, in any case, when heat ink is liquefied by application of heat energy according to a recording signal and liquid ink is ejected, or when the ink reaches a recording medium, it begins to solidify. The present invention is also applicable to the case of using an ink that has a property of being liquefied only by energy. In this case, the ink is disclosed in JP-A-54-56847 or JP-A-60.
As described in JP-A-71260, it may be configured to face the electrothermal converter in a state of being held as a liquid or a solid in the concave portion or the 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, as a form of a recording apparatus provided with a recording mechanism using the liquid jet recording head of the present invention, in addition to the one used as an image output terminal of information processing equipment such as a computer, it is combined with a reader or the like. Copier,
Further, it may be a facsimile device having a transmitting / receiving function.

FIG. 12 is a block diagram showing a schematic configuration when the recording apparatus of the present invention is applied to an information processing apparatus having a function as a word processor, a personal computer, a facsimile apparatus, a copying apparatus.

In the figure, reference numeral 1801 denotes a control unit for controlling the entire apparatus, which includes a CPU such as a microprocessor and various I / Os.
It has a port and outputs control signals, data signals, etc. to each section, and controls by inputting control signals and data signals from each section. A display unit 1802 displays various menus, document information, image data read by the image reader 1807, and the like on this display screen. A transparent pressure-sensitive touch panel 1803 is provided on the display unit 1802. By pressing the surface of the touch panel 1803 with a finger or the like, items or coordinate positions can be input on the display unit 1802.

1804 is an FM (Frequency M)
sound source section, the music information created by a music editor or the like is stored in the memory section 1810 or the external storage device 18
The data is stored as digital data in 12, and is read from the memory or the like to perform FM modulation. FM
The electric signal from the sound source unit 1804 is converted into an audible sound by the speaker unit 1805. The printer unit 1806 has the recording apparatus of the present invention applied as an output terminal of a word processor, a personal computer, a facsimile apparatus, and a copying apparatus.

Reference numeral 1807 denotes an image reader unit for photoelectrically reading and inputting original data, which is provided in the middle of the original feeding path and reads various originals such as facsimile originals and copy originals. The image reader unit 1808
It is a transmission / reception unit of a facsimile (FAX) that transmits the original data read in 07 by facsimile and receives and decodes the transmitted facsimile signal, and has an interface function with the outside. Reference numeral 1809 denotes a telephone unit having various telephone functions such as a normal telephone function and an answering machine function.

Reference numeral 1810 denotes a ROM for storing a system program, a manager program, other application programs, etc., a character font, a dictionary, etc.,
It is a memory unit including an application program loaded from the external storage device 1812, document information, a video RAM, and the like.

Reference numeral 1811 denotes a keyboard unit for inputting document information and various commands.

An external storage device using a floppy disk, a hard disk or the like as a storage medium.
Reference numeral 12 stores document information, music or voice information, a user application program, and the like.

FIG. 13 is a schematic external view of the information processing apparatus shown in FIG.

In the figure, reference numeral 1901 denotes a flat panel display using liquid crystal or the like, which displays various menus, graphic information, document information and the like. By pressing the surface of the touch panel 1803 on the display 1901 with a finger or the like, coordinate input or item designation input can be performed.
1902 is a handset used when the device functions as a telephone. The keyboard 1903 is detachably connected to the main body via a cord, and various document information and various data can be input. The keyboard 1903 is also provided with various function keys 1904 and the like. Reference numeral 1905 is an insertion port of a floppy disk into the external storage device 212.

Reference numeral 1906 denotes a paper placing section for placing an original read by the image reader section 1807. The read original is discharged from the rear of the apparatus. When receiving a facsimile, the data is recorded by the inkjet printer 1907.

In the above description, the display unit 1802 is C
Although it may be RT, a flat panel such as a liquid crystal display using a ferroelectric liquid crystal is preferable. This is because in addition to being small and thin, it is possible to reduce the weight.

When the information processing apparatus functions as a personal computer or a word processor, various information input from the keyboard unit 211 is processed by the control unit 1801 according to a predetermined program, and the printer unit 18 is processed.
It is output as an image in 06.

When functioning as a receiver of a facsimile apparatus, the facsimile information input from the FAX transmission / reception unit 1808 via the communication line is received by the control unit 1801 according to a predetermined program and processed by the printer unit 1806.
Is output as a received image.

In the case of functioning as a copying machine, a document is read by the image reader unit 1807, and the read document data is transferred to the printer unit 18 via the control unit 1801.
It is output as a copied image in 06. In addition, when functioning as a receiver of a facsimile apparatus, the image reader unit 1
The document data read by 807 is the control unit 180.
After the transmission processing according to the predetermined program by 1,
It is transmitted to the communication line via the FAX transmission / reception unit 1808.

The information processing apparatus described above may be an integral type in which an ink jet printer is built in the main body as shown in FIG. 14, and in this case, it becomes possible to further enhance the portability. In the figure, parts having the same functions as those in FIG. 13 are designated by the corresponding reference numerals.

By applying the recording apparatus of the present invention to the multifunctional information processing apparatus described above, a high-quality recorded image can be obtained at high speed and with low noise, so that the function of the information processing apparatus is further improved. It becomes possible.

[0099]

As described above, according to the present invention, when printing is performed at a density higher than at least a certain density, the printing can be performed by superposing the ink and the printability improving liquid, Due to the influence of the printability improving liquid on the ink due to the overlapping, it is possible to increase the density of the print portion.

As a result, for example, it is possible to perform printing with good gradation characteristics without providing plural kinds of inks having different densities for black, cyan, magenta, and yellow, respectively.

Further, the pixels with high density are about 25% of the whole.
If it exists as described above, it is possible to impart water resistance to the printed image by the coloring material insolubilized by the treatment liquid.

[Brief description of drawings]

FIG. 1 is a perspective view showing an inkjet printing apparatus according to an embodiment of the present invention.

FIG. 2 is a perspective view showing an inkjet unit in the apparatus.

FIG. 3 is a block diagram showing a control configuration in the above apparatus.

FIG. 4 is a diagram showing a relationship between a density value of an input image and a density value of an output signal.

FIG. 5 is a flowchart showing a procedure of ternarization processing according to the first embodiment of the present invention.

FIG. 6 is a block diagram showing a configuration for generating ejection data in the first embodiment.

FIG. 7 is a schematic diagram showing an example of grayscale recording according to the first embodiment.

8A and 8B are diagrams showing a state of permeation of ink into a print medium.

FIG. 9 is a schematic view showing a head group according to a second embodiment of the present invention.

FIG. 10 is a block diagram showing a configuration for generating ejection data in the second embodiment.

FIG. 11A is a perspective view of an inkjet unit according to a fourth embodiment of the present invention, and FIG. 11B is a diagram showing a configuration of a recording tank.

FIG. 12 is a block diagram showing an example of an information processing system using the inkjet printing apparatus according to each of the above embodiments.

FIG. 13 is an external perspective view of the system.

FIG. 14 is an external view showing another example of the system.

[Explanation of symbols]

 20Y, 20M, 20C, 20K, 21 Tanks 30Y, 30M, 30C, 30K, 31 Head 101 Carriage 104, 105 Guide Axis 106 Paper 107 Operation Section 108 Platen 109 Feed Roller 110 Recovery Unit 402 Control Section 403 Memory 410 Head Control Section 602 , 1002 Masking circuit 603, 1003 UCR, Black generation circuit 604, 4004 γ correction circuit 605, 4005 Three-valued circuit 1006 Four-valued circuit 606, 1007 YMCKS data generation circuit 607, 1008 Head drive circuit

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Hiroshi Taka 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Hitoshi Sugimoto 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Incorporated (72) Inventor Masao Kato 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Yutaka Kurabayashi 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc.

Claims (14)

[Claims] 1. In an inkjet printing apparatus that prints by ejecting ink and a printability improving liquid applied to a print medium to improve printability in inkjet printing onto a print medium to perform multivalue printing based on image data. Multivalue data generating means for generating concentration data, and printability for generating data for ejecting the printability improving liquid from at least the density data having a larger value among the multivalued concentration data generated by the multivalue data generating means. Improving liquid ejection data generating means, ejection data generating means for generating data for ejecting ink based on multivalued density data generated by the multivalued data generating means, and printability improving liquid ejection data generating means for generating The lesser of the ejection data and the ejection data generated by the ejection data generating means. Discharge control means for applying ink discharged from the ink discharge section and printability improving liquid discharged from the liquid discharge section to the print medium in an overlapping manner based on the discharge data corresponding to the density data having a larger value, An inkjet printing device characterized by comprising: 2. The ink jet printing apparatus according to claim 1, wherein the ink ejecting section is a plurality of ink ejecting sections that eject inks having different coloring materials. 3. The printability improving liquid discharge data generation means uses the logical sum of at least larger density data of multivalued density data of each of the plurality of inks having different color materials to obtain the liquid discharge unit. The inkjet printing apparatus according to claim 2, wherein the data to be ejected is generated. 4. The ink jet printing apparatus according to claim 1, wherein the ejection control unit further ejects the ink having the same color material a plurality of times to the same pixel. 5. The ink ejecting section can change the ejected ink amount, and the ejection control means further changes the ejected ink amount of the ink ejecting head. The inkjet printing device according to any one of 1. 6. The ink jet printing apparatus according to claim 1, wherein a plurality of types of ink having a color material other than black are provided with different concentrations of the color material. 7. The ink jet printing apparatus according to claim 5, wherein the ejection control unit further ejects the printability improving liquid onto the pixels having a predetermined concentration. 8. The inkjet according to claim 1, wherein the printability improving liquid contains a cationic substance having a low molecular component and a high molecular component, and the ink contains an anionic dye. Printing equipment. 9. The printability improving liquid contains a cationic substance of a low molecular component and a high molecular component, and the ink contains an anionic compound and a pigment. The inkjet printing apparatus according to any one of claims. 10. The ink ejecting unit and the liquid ejecting unit generate bubbles in the ink or the printability improving liquid by utilizing thermal energy, and eject the ink by the generation of the bubbles. Item 10. The inkjet printing apparatus according to any one of Items 1 to 9. 11. In an inkjet printing method for printing by applying ink to a print medium, an ink ejecting section for ejecting ink, and a printability improvement imparted to a print medium for improving printability in inkjet printing. A liquid ejecting unit for ejecting liquid is prepared, and at least when printing with a higher density, the ink ejected from the ink ejecting unit and the printability improving liquid ejected from the liquid ejecting head are used. An inkjet printing method, comprising: each step of performing printing by superimposing on a print medium. 12. In an inkjet printing method for performing gradation printing by varying print density within a dot area, which is an area unit for one dot in an image, by applying a liquid to the dot area, An ink jet printing method, characterized in that a sub gradation having a print density higher than a gradation realized by dots is formed in the dot area. 13. The ink jet print according to claim 12, wherein a new gradation is formed by selectively combining the gradation realized by the dots and the sub gradation to which the liquid is applied. Method. 14. A printed matter obtained by applying ink, wherein the ink is insolubilized in at least a higher-density printed area.