JP2000103046A - Ink jet recording device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make a rapid fixing compatible with a high quality image forming in the case when a recording is performed with ink and a recording property- improving liquid. SOLUTION: An image is formed by performing a switchover between a first recording mode for discharging black ink by a recording head 1k1 and discharging a recording property-improving liquid to the same pixel from a recording head 1s and further discharging black ink to the same pixels by a recording head 1k2 to form an image, and a second recording mode for discharging black ink from the recording head 1k1 or 1k2 and discharging the recording property-improving liquid to the same pixels from the recording head 1s to form the image, and thereby shortening the fixing time at a lower density than in the first recording mode.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an ink jet recording method and an ink jet recording apparatus for forming an image by discharging ink and a recording property improving liquid onto a recording medium.

The present invention can be applied to equipment using a recording medium such as paper, cloth, nonwoven fabric, OHP paper, and the like, and specific equipment includes office equipment such as printers, copiers and facsimiles, and mass production equipment. be able to.

[0003]

2. Description of the Related Art Conventionally, paper, cloth, plastic sheet, O
An ink jet recording apparatus that performs recording on a recording medium (hereinafter, also simply referred to as recording paper) such as an HP sheet can perform a high-density and high-speed recording operation. It is used and commercialized as a printer as an output medium of a copying machine, a facsimile, an electronic typewriter, a word processor, a workstation, etc. ing.

[0004] In this case, the ink jet recording apparatus has a configuration corresponding to these functions unique to the mounting and the usage form. Generally, an ink jet recording apparatus includes a carriage on which a recording unit (recording head) and an ink tank are mounted,
The apparatus includes a transport unit for transporting the recording paper and a control unit for controlling the transport unit. Then, the recording head for ejecting ink droplets from the plurality of ejection ports is serially scanned in a direction (main scanning direction) orthogonal to the recording paper conveyance direction (sub-scanning direction). Intermittently. This recording method
The recording is performed 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 number of nozzles for ejecting ink are linearly arranged in the sub-scanning direction, the recording head scans on the recording paper, thereby recording a width corresponding to the number of nozzles. Therefore, it is possible to achieve a high-speed recording operation.

[0005] By the way, the ink jet recording method includes:
When recording an image on a recording material called so-called plain paper, the water resistance of the image is insufficient, or when a color image is obtained, a high-density image that does not cause feathering is used. It is not easy to make it compatible with an image that does not cause bleeding, and it has been required to make it possible to obtain a color image with good image fastness and good quality.

[0006] As a method for improving the water resistance of an image, an ink in which a coloring material contained in the ink has water resistance has recently been put to practical use. However, its water resistance is still insufficient, and since it is an ink that is hardly dissolved in water after drying in principle, nozzle clogging of the recording head is likely to occur, and the apparatus configuration becomes complicated to prevent this. There was a disadvantage.

On the other hand, many techniques for improving the robustness of a recording material have been disclosed.

[0008] Japanese Patent No. 2615619 and Patent No. 26
No. 76699 discloses adjusting the application timing and the dot diameter of the ink and the processing liquid when applying the processing liquid prior to the application of the ink.

Also, US Pat. No. 4,538,160 and JP-A-7-195823 disclose that OR data of each color data of yellow, magenta, cyan, and black is used as data for applying a processing liquid. ing. Further, the above-mentioned U.S. Patent discloses an order of applying the processing liquid and the ink.

In Japanese Patent Application Laid-Open No. 8-52867,
A method for recording a processing liquid at a predetermined ratio for each pixel is disclosed.

As a printer to which such a processing liquid is actually applied, there is BJC-700J (trade name) manufactured by Canon Inc. This printer greatly improves the water resistance of a recording material by applying a treatment liquid called a water resistance enhancer to plain paper prior to image formation using a plurality of color inks.

[0012]

When an image is formed using a processing liquid and ink, the image is formed by applying the processing liquid prior to applying the ink, or by applying the processing liquid after applying the ink. The quality will be different. The problem is that the physical properties of the processing liquid and the ink are appropriately adjusted, or the processing liquid is applied before or after the ink is applied, or the amount of the processing liquid is changed depending on whether the ink is applied later. Improvements are possible but not satisfactory. As a result, in forming an image by causing the recording head to scan relative to the recording material, it is necessary to apply the processing liquid and the ink only in one direction of scanning, which is contrary to the speeding up. Become.

Therefore, when a continuous image does not exist over each scan of the print head, an image is formed by reciprocal scanning of the print head, and conversely, when there is a continuous image over each scan of the print head. A method of forming an image by scanning in only one direction of the recording head is mentioned. In this method, there is a possibility that an image such as a text can be recorded in a reciprocating manner, but when an image is printed over each scan of the recording head, a decrease in recording speed is inevitable.

In particular, there are still many black images among printed matter recorded by a printer, and it is strongly desired to record a high-quality image at high speed with only a black image. However, no technique has been disclosed for obtaining a high-speed and high-quality image by using a processing liquid, particularly by reciprocating scanning of a recording head.

In order to solve the above problems, the present inventors have proposed an ink jet printing method and an ink jet printing apparatus having a configuration in which a nozzle group for discharging a printability improving liquid is sandwiched between nozzle groups for discharging black ink. (Japanese Patent Application No. 9-101664).

According to the proposal, regardless of the forward scan and the backward scan of the recording head, one image corresponding to the black image is applied in the order of black ink, recording property improving liquid, and black ink. Irrespective of the type of recording, the same image is obtained regardless of whether the recording is performed in the forward scan or the backward scan. As a result, reciprocal recording is always possible and high speed is achieved.

The present invention is a further development of the above-mentioned proposal, and is directed to a case where a recording head configuration in which a group of nozzles for ejecting a printability improving liquid is sandwiched by a group of nozzles for ejecting black ink is actually applied to a printer. And a method of applying a recording improving liquid and ink.

According to the present invention, when printing is performed by arranging a group of nozzles for ejecting a printability improving liquid from both sides of a nozzle row for ejecting ink in parallel in a relative scanning direction of a recording material, the fixing time is shortened. It is an object of the present invention to obtain an image with less noticeable streaks.

[0019]

In order to achieve the above object, the present invention provides a first nozzle group for ejecting a first ink and a second nozzle group for ejecting a second ink having the same color as the first ink. A second nozzle group, and a third nozzle group that discharges a printability improving liquid for improving the printability of the first ink and the second ink, wherein the first nozzle group and the third
An ink jet recording apparatus in which a nozzle group and a second nozzle group are arranged in this order in a relative scanning direction with respect to a recording material, wherein the first ink, the recording property improving liquid, the second ink, Alternatively, a first recording mode for forming an image so as to include at least pixels to be applied on a recording material in the order of the second ink, the recording property improving liquid, and the first ink; Recording mode switching means for switching between a second recording mode in which an image is formed so as to include at least pixels to be applied on a recording material in the order of the recording property improving liquid or the second ink and the recording property improving liquid. Recording control means for performing recording in the recording mode selected by the recording mode switching means.

In the present invention, the improvement of the recording property means improving the image quality such as density, saturation, sharpness degree of the edge portion, dot diameter, etc., improving the fixability of the ink, water resistance and light resistance. This includes improving weather resistance such as image quality, that is, image storability, and suppressing the occurrence of bleeding and white fogging. Further, the recording property improving liquid is a liquid that contributes to the improvement of the printability, is a liquid containing a substance that insolubilizes or aggregates the coloring material in the ink, and is a liquid that insolubilizes the dye in the ink and the liquid in the ink. And the like, which cause dispersion destruction of the above pigment. Here, the insolubilization means that the anionic group contained in the dye in the ink and the cationic group of the cationic substance contained in the recording-enhancing liquid ionically interact with each other to form an ionic bond. This is a phenomenon in which the uniformly dissolved dye separates from the solution. In the present invention, without necessarily insolubilizing all the dyes in the ink, as described in the present invention, color bleed suppression, improved coloring, improved character quality,
The effect of improving the fixing property is obtained. Aggregation is used in the same meaning as insolubilization when the colorant used in the ink is a water-soluble dye having an anionic group. When the coloring agent used in the ink is a pigment, the pigment dispersant or the cationic group of the cationic substance contained in the recording surface improving liquid and the pigment surface causes an ionic interaction to disperse the pigment. This includes destruction and an increase in pigment particle size. Usually, the viscosity of the ink increases with the aggregation. In the present invention, even if all the pigments or pigment dispersants in the ink do not necessarily agglomerate, the effects of suppressing color bleeding, improving color development, improving character quality, and improving fixability as described in the present invention can be obtained. can get.

[0021]

BEST MODE FOR CARRYING OUT THE INVENTION The present inventors have developed a liquid (a recording-improving liquid) for insolubilizing a coloring material in an ink for the purpose of obtaining a high-quality image with excellent fixability of the ink to a recording material. ) And the ink containing the colorant have been intensively studied for the relationship between the permeability of each of the inks to the recording material and the order in which the recording property improving liquid and the ink are applied to the recording material, and the following findings were obtained.

First, in order to reduce feathering on a recording material and obtain a high-quality image, a so-called additional ink having low permeability to the recording material is usually used. However, when a recording property improving liquid for insolubilizing the coloring material in the ink is used together with the ink, if the recording property improving liquid having low permeability to the recording material is used, the fixability on the recording material is poor. The problem arises. In addition, when the ink and the recording property improving liquid are applied onto the recording material, a minute mist composed of a mixture of the ink and the recording property improving liquid is likely to be generated, and the ink or the ink adheres to the ejection port surface of the recording head and the ink or the like is formed. This may affect the ejection direction of the recording-improvement liquid or cause non-ejection, resulting in reduced reliability.

Therefore, if the ink having low permeability to the recording material is used as the ink, and the ink having high permeability is used as the printability improving liquid, the ink is applied to the same place after discharging the printability improving liquid. In addition, since the recording property improving liquid applied earlier tends to bleed, the ink applied later moves with the flow of the recording property improving liquid and causes feathering, thereby deteriorating the image quality.

On the other hand, if ink having a high permeability to a recording material is used as the ink and a liquid having a low permeability is used as the recording property improving liquid, feathering is likely to occur and the image quality deteriorates.

As another combination, when ink having a high permeability to a recording material is used as an ink and a liquid having a high permeability is used as a recording improving liquid, feathering is also likely to occur and the image quality deteriorates. .

However, an ink having a low permeability to a recording material is used as the ink, and a liquid having a high permeability is used as a recording performance improving liquid. When the liquid was applied and the ink was applied again to the same place, the fixability was good,
It has been found that since feathering is small, the image quality is high, and it is difficult to generate minute mist composed of a mixture of ink and a recording improving liquid. The reason is that
First, a state in which feathering is unlikely to occur by applying ink having low permeability to the recording material is formed on the recording material, and then the above-described method is applied even if a high permeability recording liquid is applied to the same location. The ink with low permeability is less likely to bleed because it has been applied first, while the recording-enhancing liquid is permeable so that fixability can be obtained in a short time, and in such an appropriately controlled state Since additional ink with low permeability is applied to the same location, the coloring material in the ink is unlikely to sink into the recording material, and is present on the surface side,
It is considered that a high density image can be obtained.
In this way, the ink is affected by the permeability of the recording-enhancing liquid by applying the recording-enhancing liquid having high permeability to the same portion of the recording material in the order in which the recording-enhancing liquid is sandwiched between the inks having low permeability. It is difficult to obtain a high-quality image with less feathering.

As described above, by using an ink having a low permeability to a recording material and a recording property improving liquid having a high permeability to the recording material, the ink, the recording property improving liquid, and the ink are applied in this order. It has become possible to obtain a high-quality image with good fixability.

According to the above method, there is no practical problem with respect to the fixing property. However, when the recording material is very low in permeability, such as a postcard made by government, or when a high density image is recorded. In this case, it is required to further shorten the fixing time. Therefore, in addition to the mode for obtaining a normal high-density high-quality image, it is necessary to set a mode for thinning out the applied amount of ink in the normal high-density recording mode at a predetermined rate in the printer. In this mode, the density is lower than in the normal mode, so that the fixing time is shorter.

Several methods are conceivable as methods for thinning out the applied amount of ink.

First, as a first method, there is a method of thinning out pixels constituting an image recorded in a normal mode at a predetermined ratio. In this method, the pixels constituting the image are provided with the ink and the recording quality improving liquid in the order of the ink, the recording quality improving liquid, and the ink, so that the fixing time is the same as in the normal mode when viewed in pixel units, Since the total amount of ink applied to the recording material is reduced, the actual fixing time is reduced. But,
In order to apply ink, recordability improving liquid, and ink in this order,
As described above, bleeding of the ink is unlikely to occur, and if the landing position accuracy of the ink droplets ejected from the recording head is insufficient, the image may have a noticeable streak.

Next, as a second or third method, there is a method in which, in a mode in which recording is performed in a normal mode, one of inks applied before and after the application of the printability improving liquid is not applied. .

First, as a second method, pixels forming an image are formed without applying ink prior to applying the printability improving liquid.
In the method in which the recording property improving liquid and the ink are applied in this order, as described above, an image having much feathering is generated due to the high permeability of the recording property improving liquid. In addition, in this method, a minute mist composed of a mixture of the ink and the recording property improving liquid that bounces off from the recording material when the ink is applied adheres to the ejection opening surface from which the ink is ejected, and forms the ink. It has been found that the ejection direction is easily affected.

On the other hand, as a third method, a method of applying pixels constituting an image in the order of ink and recording property improving liquid without applying ink after the application of the recording property improving liquid is performed first. Since the ink having low permeability to the material is applied, the recording quality improving liquid having a relatively high quality is applied after the ink is applied, and the recording property improving liquid having high permeability is applied after the ink is applied.
In addition, since the coverage area of the ink applied to the same image is larger than that of the first method, even if the landing position accuracy of the ink droplets ejected from the recording head is insufficient, the quality of the streaks is conspicuous. It does not mean that it drops. in this case,
A minute mist composed of a mixture of the ink and the recording success liquid that bounces off from the recording material when the recording property improving liquid is applied may adhere to the ejection opening surface that discharges the recording property improving liquid. It has been found that the ejection direction of the recording-improvement liquid is not significantly affected. Even if there is some influence, it can be said that the recording-improvement liquid is a transparent liquid and therefore hardly affects the image.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

Embodiment 1 FIG. 1 is a schematic perspective view showing the structure of an ink jet printer (hereinafter also referred to as a printer) as an example of an ink jet recording apparatus to which the present invention can be applied.

This printer has a carriage 2 on which a recording head 1s for discharging a recording quality improving liquid and recording heads 1k1 and 1k2 for discharging black ink are mounted.
And a flexible cable 3 for sending an electric signal from the printer body to the recording head, a cap unit 4 having recovery means, a paper feed tray 8 for feeding a recording material 7, and the like. The recording head 1s is disposed so as to be located between the recording heads 1k1 and 1k2.
Further, the cap unit 4 includes the recording heads 1s, 1k
Cap members 5s, 5k1, 5k corresponding to 1, 1k2
2, a wiper blade 6s made of rubber or the like and corresponding to the recording head 1s, and a wiper blade 6 corresponding to the recording heads 1k1 and 1k2. The printer having such a configuration includes the recording heads 1s, 1k1, 1k2.
In the direction perpendicular to the transport direction A of the recording material (main scanning direction)
B performs printing in a width corresponding to the number of nozzles by performing a serial scan, and on the other hand, conveys the recording material intermittently by a feed amount equal to the recording width when not recording.

Each of the recording heads 1s, 1k1, and 1k2 has 64 nozzles.
ng / drop of printability improving liquid or ink is ejected.

FIG. 2 is an electric control block diagram of the above-described ink jet printer.

Reference numeral 301 denotes a system controller for controlling the entire apparatus, which is internally used by a microprocessor, a storage element (ROM) storing a control program, and used by the microprocessor for processing. A storage element (RAM) and the like are arranged, and constitute a recording mode switching means in the present invention. Reference number 3
02 is a driver for driving the recording head in the main scanning direction, and similarly, 303 is a driver for moving the recording material in the sub scanning direction. Reference numeral 304,
Reference numeral 305 denotes a motor corresponding to the drivers 302 and 303, and operates by receiving information such as speed and moving distance from the drivers.

Reference numeral 306 denotes a host computer, which transfers information to be printed to the printing apparatus of the present invention, and selects a printing mode set on the printer side. Information is also included. Reference numeral 307 denotes a reception buffer for temporarily storing data from the host computer 306.
01 is a frame memory for expanding data from the system controller into image data, and has a memory size necessary for printing. In the present embodiment, a frame memory capable of storing one print sheet will be described, but the present invention is not limited to the size of the frame memory. Reference numeral 309 denotes a storage element for temporarily storing data to be printed, and a print buffer 309k for black ink and a print buffer 30 for printability improving liquid.
9s, and the storage capacity changes depending on the number of nozzles of the print head. Reference numeral 310 denotes a recording control unit for appropriately controlling the recording head in accordance with a command from the system controller. The recording control unit controls the printing speed, the number of print data, and the like. Is also generated. Reference numeral 311 denotes a driver for driving the print head 1s for discharging the printability improving liquid and the print heads 1k1 and 1k2 for discharging the black ink, and is controlled by a signal from the print control unit 310. You.

First, image data is transferred from the host computer 306 to the reception buffer 307 and is temporarily stored. Next, the stored image data is read out by the system controller 301 and stored in the buffer 3.
09 is expanded. The recording control unit 310
Based on the data developed in 9, data for ejecting ink and the printability improving liquid is created. Then, the operation of the print head is controlled based on the image data in each buffer and the data for discharging the printability improving liquid.

In the present embodiment, the following inks and recording property improving liquids were used.

(Ink) Glycerin 5 parts by weight Thiodiglycol 5 parts by weight Urea 5 parts by weight Isopropyl alcohol 4 parts by weight C.I. I Direct Black 154 3 parts by weight Water 78 parts by weight (Recordability improving liquid) Polyallylamine hydrochloride 1 part by weight Tributylamine chloride 1 part by weight Thiodiglycol 7 parts by weight Acetyleneol 0.5 part by weight (manufactured by Kawaken Chemical Co., Ltd.) It is a trade name and the chemical substance name is ethylene oxide-2,4,7,9-tetramethyl-5-
Desine-4,7-diol. 90.5 parts by weight of water

In the ink jet printer according to the present embodiment, in addition to the mode A for obtaining a normal high-density high-quality image, a mode B for thinning out the applied amount of ink in the normal high-density recording mode at a predetermined ratio is provided. It is prepared. Further, both modes A and B are configured so that bidirectional recording is possible. Here, which recording mode, Mode A or Mode B, is used to form an image is instructed by the host computer.

In the mode A, the print head 1 s and the print head 1 s both scan in the forward scan (recording is started from the recovery means side) and in the backward scan (recording is started toward the recovery means side). The same image data was sent to all of 1k1 and 1k2, and the above-described printability improving liquid and ink were ejected.

The discharge amount per recording head is 40n.
g, the ratio of the printability improving liquid to the black ink is 40 / (40 + 40) = 0.5 (50%).

FIGS. 3A to 3D are schematic plan views illustrating an example of a process of discharging black ink and a printability improving liquid to each print pixel in mode A. FIG.
FIG. 3A shows the result of ejecting black ink from, for example, the recording heads 1k1 and 1k2 to 2 × 2 pixels and ejecting the recording property improving liquid from the recording head 1s. Therefore, in order to obtain the image of FIG. 3A, first, black ink is ejected by the recording head 1k1 as shown in FIG. 3B, and then the same pixel is ejected as shown in FIG. Then, the printability improving liquid is ejected by the printhead 1s, and finally, the black ink is applied to the same pixels as those shown in FIGS. 3B and 3C by the printhead 1k2 as shown in FIG. Is discharged. Through the above steps, the image formation using the black ink and the printability improving liquid shown in FIG.

On the other hand, in mode B, in the forward scan of the print head, the same image data is sent to all the print heads 1k1 and 1s, and the printability improving liquid and black ink are ejected.
At this time, no black ink is ejected from the recording head 1k2. In the return scan of the print head, the print head 1k
The same image data was sent to all 2 and 1 s, and the above recording improving liquid and black ink were ejected. At this time, the recording head 1
No black ink is ejected from k1. Since the discharge amount of each print head is 40 ng, the ratio of the printability improving liquid to the black ink is 40/40 = 1.0 for both forward scan and backward scan.
(100%).

FIGS. 4A to 4E are schematic plan views illustrating an example of a process of discharging black ink and a printability improving liquid to each print pixel in mode B.
FIG. 4A shows the result of ejecting black ink from the recording head 1k1 or 1k2 to 2 × 2 pixels, for example, and ejecting the recording property improving liquid from the recording head 1s. In the forward scan of the recording head, in order to obtain the image of FIG. 4A, first, as shown in FIG.
1, black ink is ejected, and then, as shown in FIG. 4C, a printability improving liquid is ejected to the same pixel by the print head 1 s. Subsequently, no black ink is ejected from the recording head 1k2. In order to obtain the image shown in FIG. 4A in the backward scanning of the print head, first, black ink is ejected by the print head 1k2 as shown in FIG. 4D, and then, as shown in FIG. As described above, the printability improving liquid is discharged from the printhead 1s to the same pixel. Subsequently, no black ink is ejected from the recording head 1k1. Through the above steps, the image formation using the black ink and the printability improving liquid shown in FIG.

It was confirmed that the black image obtained in the mode A of this embodiment was a sharp image with high density and little feathering, and furthermore had sufficient water resistance.

The black image obtained in mode B had a lower density than mode A, but was a uniform image. further,
When recording was performed on a government-made postcard, high-speed fixing could be realized so that the hand or the image was not stained even if the printing surface was touched immediately after printing.

Even when a large number of pages were printed in both mode A and mode B, no fine mist composed of a mixture of ink and a printability improving liquid adhered to the discharge port surface of the print head.

<Embodiment 2> In this embodiment, the amount of black ink applied to mode B in Embodiment 1 is increased.

FIG. 5 is a schematic plan view for explaining an example of a process for discharging black ink and a printability improving liquid to each print pixel. The print head 1k1 and print head are provided for the pixels a11 and a22. The black ink is ejected from 1k2 and the printability improving liquid is ejected from the print head 1s. The recording head 1k is provided for the pixels a12 and a21.
Black ink is ejected from only one of the recording head 1 and the recording head 1k2, and the recording property improving liquid is ejected from the recording head 1s. At this time, as in the first embodiment, in the forward scan of the print head, black ink is applied to the pixels a11 and a22 by the print head 1k1, subsequently, the printability improving liquid is applied by the print head 1s, and Recording head 1
Black ink is applied by k2. Further, black ink is applied to the pixels a12 and a21 by the recording head 1k1, and subsequently, a recording property improving liquid is applied by the recording head 1s. On the other hand, in the backward scan of the print head, the print head 1k2 applies black ink to the pixels a11 and a22,
Subsequently, a printability improving liquid is applied by the print head 1s, and finally, black ink is applied by the print head 1k1. Further, black ink is applied to the pixels a12 and a21 by the print head 1k2, and subsequently, a printability improving liquid is applied by the print head 1s.

In the mode B described above, the first embodiment
A black image having a higher density than that of Mode B was obtained.

<Other Embodiments> In Embodiments 1 and 2, printers that form only a black image using black ink and a printability improving liquid have been described. The present invention can be applied to a color printer to which a recording head for discharging ink is added. In this case, if two recording heads for ejecting color inks are prepared for each color and the recording heads for ejecting the recording property improving liquid are sandwiched between the recording heads, color printing can be performed in the same manner as in the first and second embodiments. Although reciprocating printing is possible, color printing may be performed by one recording head for each color if color printing is not performed.

In the first and second embodiments, the mode A for obtaining a normal recording density and the mode B for shortening the fixing time at a density lower than that of the mode A are provided. In this manner, the ink and the recording property improving liquid may be applied. In this case, as in the mode B of the second embodiment, pixels applied in the order of black ink, printability improving liquid and black ink, and pixels applied in the order of black ink and printability improving liquid can be mixed. For example, as shown in FIG. 6, 75% of the pixels applied in the order of black ink, recording property improving liquid and black ink, and 25% of the pixels applied in order of black ink and recording property improving liquid. If it is applied so that high density and high-speed fixing can be compatible to some extent.

[0058]

As described above, according to the present invention,
By providing a configuration in which a recording head that discharges a recording property improving liquid is sandwiched between recording heads that discharge ink, and a mode in which an image is formed by applying ink, a recording property improving liquid, and ink in this order, high density and high quality are achieved. An image can be obtained. Further, by providing a mode in which an image is formed by applying ink and a recording property improving liquid in this order, an image having a short fixing time and less streak can be obtained. Further, in both modes, a small mist composed of a mixture of ink and a printability improving liquid is less likely to adhere to the printhead ejection opening surface, so that a printing apparatus with high printhead reliability can be obtained.

[Brief description of the drawings]

FIG. 1 is a schematic perspective view of a printer as a first embodiment of the present invention.

FIG. 2 is an electric control block diagram of the printer shown in FIG.

FIG. 3 is a schematic cross-sectional view illustrating an example of a process of discharging ink and a printability improving liquid to each print pixel in a mode A according to the first embodiment.

FIG. 4 is a schematic cross-sectional view illustrating an example of a process of discharging ink and a printability improving liquid to each print pixel in a mode B according to the first embodiment.

FIG. 5 is a schematic cross-sectional view illustrating an ink and a printability improving liquid applied to each print pixel in a mode B according to a second embodiment.

FIG. 6 is a schematic cross-sectional view illustrating an ink and a printability improving liquid applied to each print pixel in another embodiment.

[Explanation of symbols]

 1s, 1k1, 1k2 Recording head 2 Carriage 7 Recording material 301 System controller 302, 303 Driver 304, 305 Motor 306 Host computer 307 Receiving buffer 308 Frame memory 309 Buffer 310 Recording control unit

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2C056 EA13 EC71 EC80 ED03 ED07 FA03 FA11 HA44 2C057 AF39 CA04 CA05 CA07 2H086 BA02 BA51 BA59

Claims (6)

[Claims] A first nozzle group that discharges a first ink; a second nozzle group that discharges a second ink having the same color as the first ink; And a third nozzle group that discharges a printability improving liquid for improving the printability of the second ink. The first nozzle group, the third nozzle group, and the second nozzle group are arranged in this order. An ink jet recording apparatus arranged side by side in a relative scanning direction with respect to a recording medium, comprising: a first ink, a recording property improving liquid, a second ink,
Alternatively, a first recording mode for forming an image so as to include at least pixels to be applied on a recording material in the order of the second ink, the recording property improving liquid, and the first ink; Recording mode switching means for switching between a second recording mode in which an image is formed so as to include at least pixels to be applied on a recording material in the order of the recording property improving liquid or the second ink and the recording property improving liquid. An ink jet recording apparatus comprising: a recording control unit configured to perform recording in a recording mode selected by the recording mode switching unit. 2. In the first printing mode, the first ink, the second ink, and the printability improving liquid are applied to one pixel by the same scanning. The inkjet recording apparatus according to claim 1. 3. In the second printing mode, the first ink and the printing property improving liquid or the second ink and the printing property improving liquid applied to one pixel are: 2. The ink jet recording apparatus according to claim 1, wherein the ink is applied by the same scan. 4. The ink jet recording apparatus according to claim 1, wherein the first ink and the second ink are black ink. 5. The ink jet recording apparatus according to claim 1, wherein the recording property improving liquid contains a component having an action of insolubilizing or aggregating a colorant in the ink. 6. The first nozzle group, the second nozzle group, and the third nozzle group each include a thermal energy generating means for applying thermal energy to ink to generate bubbles and ejecting the ink. The ink jet recording apparatus according to any one of claims 1 to 5, wherein: