JP3015231B2 - Color inkjet recording method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color ink jet recording method capable of recording a color image clearly and at a high density, and more particularly, to a color ink such as yellow, magenta, cyan or green, red, blue or the like. The present invention relates to a color inkjet recording method using black ink such as black.

[0002]

2. Description of the Related Art An ink jet recording method has advantages such as low noise, low running cost, easy downsizing of an apparatus, and easy colorization.

In the conventional ink jet color recording method, it is generally necessary to use a special paper (coated paper) in order to obtain a high color and high quality image without ink bleeding.

[0004] In recent years, it has become possible to impart printability to plain paper due to the technical innovation of ink, but at present the quality is still at an insufficient level. The biggest factor is bleeding between color inks of a color image on plain paper (so-called bleeding).

[0005] In order to prevent bleeding between color inks, inks that have a high penetration rate to plain paper and are fast drying have been developed.

Generally, a color ink jet recording method is as follows.
Using cyan, magenta and yellow inks,
Furthermore, color image recording is performed using four color inks with black added. However, when the above-described inks are used for all inks, the inks immediately penetrate and fix on the paper surface, so that the color image recording is performed. It was found that the ink bleeding between the colors of the image portion was prevented, but the black image portion had a low print density and was of poor quality.

[0007] When the black image portion exists independently of the color image portion, the quality is particularly poor. For example, when the black image is a character, the ink is slightly blurred along the paper fibers and lacks sharpness. It was obscure and had to be very poor.

For this reason, black ink used for a black image has been improved by using a type of ink having a relatively slow permeation time to improve print quality and increase print density.

[0009]

However, when a color ink having a high ink penetration rate with respect to the paper surface and a black ink forming a black image having a relatively low penetration rate are used, a full-color image is used. When obtaining a black image, especially when there is a black image in the background of the color image part,
It was found that the black ink, which has a slow ink penetration, flows into the color ink image and significantly deteriorates the print quality.

[0010] The present invention has been made in view of the above points,
An object of the present invention is to provide a color ink jet recording method capable of improving image quality when a color image is adjacent to a black image.

[0011]

According to the present invention, a desired color image is formed on a recording material using black ink and a plurality of color inks different from the black ink. In the color ink jet recording method, when a color image is present adjacent to a black image, all the adjacent portions of the color image in the black image are formed by dots formed by mixing a plurality of color inks, and the black image around the adjacent portion is formed. It is formed by mixing dots of black ink and dots of mixed color ink. At this time, the ratio of the black ink dots is increased as the distance from the adjacent portion increases. Or
The black image adjacent to the color image in the black image is formed as an extended pixel in units of a plurality of pixels, and the extended pixel is processed as a black image in which dots of color ink and black ink are arranged at a predetermined ratio, As the distance from the adjacent portion increases, the ratio of black ink dots is increased.

As a result, the color gradually changes in the black image adjacent to the color image, so that there is no sudden change in color tone and the appearance is improved.

[0013]

【Example】

(Embodiment 1) FIG. 1 is a schematic diagram of a color ink jet recording apparatus to which the present invention can be applied. In the figure, reference numeral 101 denotes a carriage on which an ink jet recording head 102 is mounted. A recording head 102 has a plurality of discharge nozzles having a plurality of color inks and a black ink. Reference numeral 110 denotes a color ink tank in which three types of ink tanks of yellow Y, cyan C, and magenta M are integrally formed. Reference numeral 111 denotes a black Bk ink tank.

When the two ink tanks are pushed into insertion holes separately provided in the cartridge 103, the two ink tanks are provided on the recording head 102 and a rubber sheet portion (not shown) provided on the ink tanks 110 and 111. Stainless steel pipe or the like is connected. By doing so, the ink can be supplied from the ink tanks 110 and 111.

When a print signal is received from a host computer (not shown), the paper as a recording material is fed to a paper feed roller 108.
The paper is fed by the paper feed roller 107 and set at the printing position.

Thereafter, the recording head 102 is released from a cap (not shown), and the carriage 103 on which the recording head 102 is mounted reciprocates along the guide shafts 104 and 105 to perform printing.

FIG. 2 is a perspective view of the recording head used in the present invention. The recording head 102 has ejection nozzles for color inks for each ink, and has a plurality of nozzles for yellow, magenta, cyan, and black inks.

The discharge ports for yellow, magenta, cyan, and black are formed on the same substrate and are arranged in a straight line. Specifically, 24 ejection openings for color ink are provided for each color, and 64 ejection openings for black ink are provided. Each color has an interval equal to or greater than the nozzle pitch.

Each of these discharge ports has an ink passage for supplying ink to each of the discharge ports, and the ink nozzle corresponding to each of the discharge ports has an electrothermal energy converter for discharging ink droplets. are doing. The ink is foamed by heating the electrothermal energy converter in accordance with the input of the print signal, and the ejection of ink droplets from each ejection port is controlled by the force.

Specifically, the ink ejection amount is designed so that about 40 ng of each color is ejected from a color nozzle and about 80 ng of an ink droplet is ejected from a black nozzle.
(Here, 1 ng = 10 ^-9 g)

In the drawing, reference numeral 204 denotes a color ink tank 110.
Is made of a stainless steel pipe at the joint with the yellow ink tank so that ink can be supplied to the head. Similarly, 205 is for cyan ink and 206 is for magenta ink. Further, reference numeral 207 provided on the opposite side of the ejection port of the head 102 is a connecting portion for the black ink 111. Reference numeral 208 denotes a distributor which distributes ink supplied from each ink tank.

As described above, the color ink used in the present invention has a high ink permeability to plain paper, and the black ink has excellent print quality and print density. Uses ink with relatively low permeability.

Specifically, an ink having the following composition was used.

Yellow ink C.I. I. Direct Yellow 86 3 parts Diethylene glycol 10 parts Isopropyl alcohol 2 parts Urea 5 parts Surfactant (acetylenol) 1 part Water balance

Magenta ink C.I. I. Acid Red 289 3 parts Diethylene glycol 10 parts Isopropyl alcohol 2 parts Urea 5 parts Surfactant (acetylenol) 1 part Water balance

Cyan ink C.I. I. Direct Blue 199 3 parts Diethylene glycol 10 parts Isopropyl alcohol 2 parts Urea 5 parts Surfactant (acetylenol) 1 part Water balance

Black ink C.I. I. Direct Black 154 3 parts Glycerin 5 parts Isopropyl alcohol 2 parts Thiodiglycol 5 parts Urea 5 parts Water The remaining part is used, but it is not limited to this, and the color ink has a high ink penetration rate to the paper surface. Any black ink may be used as long as it emphasizes print quality and print density and uses a material having relatively low permeability to the paper surface.

FIG. 3 is an electric control block diagram of the above-described color ink jet printer.

In the figure, reference numeral 301 denotes a system controller for controlling the entire apparatus, and a storage element (R) in which a control program such as a microprocessor is stored inside.
OM), a storage element (RAM) used when the microprocessor performs processing, and the like. Reference numeral 302 denotes a driver for driving the print head 102 in the main scanning direction. Similarly, reference numeral 303 denotes a driver for moving paper in the sub-scanning direction. Reference numerals 304 and 305 denote motors corresponding to the driver, which receive a speed, a moving distance and the like from the driver. Reference numeral 306 denotes a host computer, which is a device for transferring information to be printed to the present color inkjet printer. Reference numeral 307 denotes a reception buffer for temporarily storing data from the host computer 306, and accumulates data until data is read from the system controller 301. Reference numeral 308 denotes a frame memory for expanding data to be printed into image data, and has a memory size necessary for printing.

In this embodiment, a frame memory capable of storing data for one printing sheet will be described, but the present invention is not particularly limited to this.

Reference numeral 309 denotes a storage element for temporarily storing data to be printed, and the storage capacity varies depending on the number of nozzles of the print head. Reference numeral 310 denotes a print control unit for appropriately controlling the print head in accordance with a command from the system controller, and for controlling the ejection timing, the number of print data, and the like. Reference numeral 311 denotes a driver for driving the heads 312Y, 312M, 312C, and 312Bk for each color, and is controlled by a signal from the print control unit 310.

FIG. 4 is a flowchart for explaining a recording operation according to an embodiment of the present invention. <Step 1> is the first step in which data is transferred from the host computer 306 and the data stored in the reception buffer 307 is processed by the system controller 301, and the stored data is read. In <Step 2>, it is determined whether the read image data includes black data or is data other than black. If black data is included, the process proceeds to step 3; otherwise, the process proceeds to step 7. In <Step 3>, it is determined whether the black image recording area of interest is character code data or bit image data. If it is a character code, go to Step 4; if it is bit image data, go to Step 5. move on. In step 4, attention is paid to the black data, and it is determined whether or not color recording data is present in a pixel at a position adjacent to the periphery of the black image recording area. If a color image exists at a position adjacent to the black image, the process proceeds to step 5; otherwise, the process proceeds to step 6. In <Step 5>, black image information that is character code data and has a color image at an adjacent position or black image information that is bit image data is developed in yellow, magenta, and cyan buffers for color recording. . In <Step 6>, the black image information is developed in a buffer for black recording. In <Step 7>, image data processing is performed on the black data such that black dots of C, M, and Y color inks and black dots of black ink are mixed at a predetermined ratio, as described later. In <Step 8>, data of each color including black is developed in a buffer for each color.
In <Step 9>, data is read from the reception buffer, and it is determined whether or not there is data to be printed and whether or not one page of data has been received. As a result of the judgment,
When there is no print data, and when there is print data,
When the data for the page has been received, the process proceeds to step 10. In <Step 10>, the printing operation is started by the recording head 102. Otherwise, return to step 1.

FIGS. 5 and 6 show examples of printed images in the case where a color image exists adjacent to a black image.

FIGS. 5 and 6 show print data sent as a bit image.
The black image adjacent to 02 is formed by printing a black dot 400 formed by mixing a plurality of color inks in a predetermined area as described above, and then forming an image with the black ink (FIG. 5). Are all black dots 4 from the above color mixture
00 is printed.

Further, a portion which is not adjacent to the color image is constituted by dots 401 of a single color of black ink.

In this case, it was found that the black image had a different color and had a poor appearance because the black dot 400 formed by the mixed color of the color ink and the dot 401 of the black ink were continuous.

FIG. 7 shows a printing example according to the first embodiment of the present invention. This is an example of a case where a color image is at the center of the image, and there is a black image adjacent to the color image.A black image formed with a plurality of color inks and a black image formed with a single black ink This is to make the boundaries due to the color difference of the image inconspicuous.

The surrounding black dots adjacent to the color image dots 402 are all formed by the black dots 400 formed by mixing the color inks under the above control.

Next, the black dots arranged around the black dots are:
Black dots 400 formed by mixing the color inks
, And black ink single color dots 401 are mixed.

In the first embodiment, the mixing ratio of the black dots 400 made of color ink and the black ink single color dots 401 is set as follows.

Since the first outer periphery is adjacent to the color dots, all adjacent black dots are changed to black dots 400 in which color ink is mixed to prevent ink bleeding, and the second outer periphery is Mixing is performed at a ratio of one dot of black ink to two dots of black formed by color ink.

Next, in the third outer periphery, the ratio of the black dots is increased by 2 dots per dot, further 3 dots per dot, and 4 dots per dot. I will carry out.

If one dot exceeds 5 dots, 0
This is controlled so that 100% of the dots are black dots.

Therefore, since the color of the black image changes stepwise, the boundary between the above two types of black images becomes inconspicuous.

Embodiment 2 FIG. 8 shows a printing example according to a second embodiment of the present invention.

This example shows a case where a color image is present at the center of the image and a black image is present around the color image. Similar to the first embodiment, a black image made of color ink and a black image made of black ink are used. This is to make the border between black images inconspicuous.

The surrounding black dots adjacent to the color image are
All are constituted by black dots 400 formed by mixing the color inks under the above control.

Next, the black dots arranged around the black dots are:
Black dots 400 formed by mixing the color inks
, And black ink single color dots 401 are mixed. In the second embodiment, the mixing of black dots made of color inks and black ink single-color dots is performed as follows.

Since the first outer periphery is adjacent to the color dots, all the adjacent black dots are changed to black dots obtained by mixing color inks to prevent bleeding of the ink, and the second and third outer dots are formed. The surroundings are mixed at a ratio of one dot of black ink to two dots of black formed by color ink.

Next, in the fourth and fifth outer peripheries, the ratio of the black dots is mixed at a ratio of one dot to one dot, and in the sixth outer perimeter, 100% of black ink dots are formed. Control to form a black image.

(Embodiment 3) FIG. 9 shows an example of printing according to a third embodiment of the present invention. This shows an example in which a color image is present and a black image is inside the color image. A case where this black image has a width of 3 dots or more will be described.

The inner black dot adjacent to the color image is
All of the above-described controls prevent the formation and bleeding of black dots 400 formed by mixing color inks.

Next, the black dots arranged inside the second inside form an image with dots 401 of a single color of black ink.

Further, for a portion of a black image that is not adjacent to a color image, an image is formed by dots 401 of black ink.

(Embodiment 4) FIG. 10 shows a printing example according to a fourth embodiment of the present invention. This is an example in which a color image is on the outermost periphery of the image and a black image is on the inside.

The inner black dot adjacent to the color image is
All are constituted by black dots 400 formed by mixing the color inks under the above control.

Next, the black dots arranged on the second inner side are such that the black dots 400 formed by mixing the color inks and the black ink single color dots 401 are mixed. Is a mixture of black dots formed by color ink and black ink single-color dots as follows.

Since the first inner periphery is adjacent to the color dot, all adjacent black dots are made into a black dot mixed with color ink in order to prevent ink bleeding, and the second and subsequent inner periphery are formed by mixing the color inks. , Black dots formed with color ink and black ink dots are mixed, and the ratio is 2:
1, 1: 1, 1: 2 are mixed.

The fifth inner periphery is controlled so that a black image is formed with 100% of black ink dots.

(Embodiment 5) FIG. 11 illustrates a case where a color image exists alone and a case where a color image extends over a black image. As described above, when a black dot is adjacent to a color dot 402, a black dot 400 obtained by mixing color ink around the black dot is used.
In the inside / outside, an image is formed by performing the processing described above by mixing the black dots 400 formed of the color ink and the black dots 401 of the black ink.

According to the embodiment described above, when there is a black image adjacent to a color image, all the black dots adjacent to the color dots forming the color image form black dots by mixing the color inks. In addition, black ink is prevented from flowing into a color image by speeding up the penetration and fixing to paper.

Next, black dots formed on the outer periphery or inside are mixed with black dots formed of the color ink and black ink single color dots by a predetermined algorithm.

By sequentially increasing the number of black ink single-color dots for the black image formed on the outer periphery or inside thereof, the boundaries between the black dots formed by mixing the color inks are conspicuous. In this case, the black ink is made to be 100% at the end.

Therefore, since the color of the entire black image gradually changes, there is no sharp change in color tone, and the appearance is improved.

(Embodiment 6) FIG. 12 is for describing Embodiment 6 and shows an example in which a black image is present in a color ink image yellow 504 (Y) on the background and adjacent to each other.

The portion of the black image 501 (BK) adjacent to the color image has been processed as an extended pixel 500 using four 2 × 2 pixels (superpixels) as one unit. In order to explain in detail the black image processing state when the color image 504 and the black image in the figure are adjacent to each other, FIG. 13 is an enlarged view of a portion A in the figure.

FIG. 13 is a diagram showing the processed pixels of the black image adjacent to the color image 504. The adjacent black image is processed as an extended pixel 500 using four 2 × 2 pixels as one unit, and is subjected to image processing using a predetermined mask (pattern). This extended pixel 500 is composed of color ink and black ink, and has the following ratio.

Y = 75% (3 pixels) M = 50% (2 pixels) C = 75% (3 pixels) BK = 25% (1 pixel).

The extended pixel 500 forms a dot by forming a dot by landing yellow, magenta, and cyan ink droplets, which are color inks, at the same location, and forms a dot by landing a yellow and cyan ink droplet at the same location. The extended pixels 500 are configured by arranging the formed 601 and the dots 501 of the black ink as shown in FIG. To make it easy to understand the positional relationship between the inks,
Mark MA was placed at the corner of.

As described in the above embodiment, BK (5
01) has a large ink ejection amount and a small ink ejection amount for color, so that the above-described ratio should be applied to the portion directly adjacent to the color image so that the boundary between the color image and the color image becomes smaller. And the color difference from the BK ink is less noticeable. However, the ratio of each color ink is not specified, and the optimum conditions are different depending on the ink ejection amount, the physical properties of the ink itself, and the like.

Here, the yellow color image (Y) 50
Extended pixel 500 was implemented for two superpixels of the black image adjacent to # 4. As described above, the appearance of black varies depending on the physical properties of the ink, the amount of ink discharged, etc., as described above.
It is desirable to change according to the characteristics on a plastic film.

FIG. 14 illustrates a procedure when four 2 × 2 pixels are used as one extended pixel. When a color image / pixel G to be noticed adjacent to the black image is detected, a process of replacing a black image in a predetermined range in the vertical and horizontal directions around the color pixel G with the extended pixel is performed.

In the present embodiment, processing is performed for four pixels both vertically and horizontally around the color pixel G. However, the present invention is not limited to this, and processing is performed with a size of 2n × 2n. It is sufficient that n = 2 in the embodiment of the present invention. By optimizing the printing mode and the number of passes for printing, a higher quality color image can be obtained.

(Embodiment 7) FIG. 15 illustrates still another example of an image. The black image (BK) is adjacent to the yellow 504 (Y) image on the background. The black image processing in the figure will be described by enlarging the portion B. The reference numerals in the figure are the same as those in FIG.

FIG. 16 shows that the color image 504 and the black image are adjacent to each other and, as described in the previous embodiment, 2 × 2 of the black image.
Are subjected to mask (pattern) processing as one extended pixel 500. In the case where four pixels are regarded as one extended pixel, a case where a fraction is too large to be divided will be described in detail.

As described above, when there is no black image to be subjected to the mask processing, a solution is achieved by performing processing for blanking that part. In the case of 500b, since there is no print dot data in the lower half of the extended pixel 500, the processing of the lower half by the mask is blank.

(Embodiment 8) FIG. 17 shows still another printing example. The processed 2 × 2 four pixels are arranged randomly instead of continuously arranging one extended pixel 500 to reduce the regularity of the extended pixels. As described above, since the mark MA is at the corner of the model of the extended pixel 500, the positional relationship can be understood.

Further, even if the extended pixels are not regularly arranged, they can be sufficiently reduced by regularly arranging the extended pixels while rotating them in one direction.

(Embodiment 9) FIG. 18 shows still another printing example. In the black ink processing, the ratio of the black ink is increased as the distance from the color ink pixel 504 increases, and the black ink included in the above-described four-pixel extended pixel is mixed at the following ratio. The extended pixels 500 in the first column have the same configuration as described above. Y = 75% (3 pixels) M = 50% (2 pixels) C = 75% (3 pixels) BK = 25% (1 pixel) It is formed with.

The extended pixels 510 in the second column are formed with Y = 50% (2 pixels) M = 50% (2 pixels) C = 50% (2 pixels) BK = 50% (2 pixels) .

The extended pixels 520 in the third column are formed with Y = 25% (1 pixel) M = 25% (1 pixel) C = 25% (1 pixel) BK = 75% (3 pixels) .

The above-described black ink mixture ratio configuration is an example, and the present invention is not limited to this. For example, it can be switched according to a printing paper, a printing mode, or the like. Further, the mixing ratio of the black ink 401 may be arbitrarily changed within a range of 10 to 90%.

In the present embodiment, the above 500, 510, 52
Although 0s are regularly arranged in each column, the present invention is not limited to this, and randomization or the like may be performed for each column as described in the above embodiment.

According to the present embodiment, it is possible to further reduce the difference in color at the boundary of the black image.

(Embodiment 10) Next, an example of switching in the print mode will be described.

For example, this recording apparatus has four print modes.

1) HQ mode (high quality) One-pass printing in which printing is performed simultaneously using all the ink discharge nozzles.

2) HS mode (high speed) Printing in which 50% thinning is performed using an odd or even number of ink discharge nozzles.

3) SHQ mode (super high quality) A first means for dividing an ink discharge nozzle into two or three blocks, processing printing, and repeating two or three printing passes to perform interpolation printing.

4) OHP Mode (Overhead Projector) A second means for dividing the ink discharge nozzles into two or three blocks, processing printing, and repeating two or three printing passes to perform overlap printing.

In each mode, a process for optimizing a black image adjacent to the above-described color ink image is performed.

Details will be described sequentially.

1) HQ mode In FIG. 7 of the first embodiment of the present invention, among the adjacent black images, three black dots 400 composed of color inks are formed.
A process is performed in which one dot of black ink 400 is mixed with one dot, and the number of dots 401 of black ink is sequentially increased.
Alternatively, the one shown in FIG. 17 of the eighth embodiment may be used.

2) HS mode One extended pixel 500 represented by the sixth embodiment of the present invention is used. The reason is that since the dots in printing are thinned out by 50%, the blurring of the boundary between the color image and the black image can be minimized. Alternatively, black ink may be mixed at a ratio of one dot to two dots in FIG. 7 of the first embodiment.

3) SHQ Mode The processing as shown in FIG. 18 of the eighth embodiment of the present invention is performed, and gradation is gradually increased so that a high image can be obtained.

4) OHP mode An extended pixel 500 represented by the sixth embodiment of the present invention.
Then, all the black images are replaced and printing is performed, and images printed with black ink are eliminated. The reason for this was that the fixing state of the ink on the OHP was different, and that the light was actually transmitted /
Alternatively, it is found that the same black dot is necessary because the color of the black image when reflected is enlarged at the time of projection. Further, it is desirable to process all black images because the fixability differs depending on the type of the film, and it is difficult to manage to prevent bleeding between the color image and the black image.

In this manner, the user can arbitrarily operate the printing mode in which the printing process suitable for the printing paper to be printed can be performed, or the mode can be automatically switched by the printing apparatus. You may.

When a color ink image and a black image are detected in the same manner as in the print mode in accordance with the environmental conditions, that is, the detection means for the environmental temperature and humidity are arranged in the recording apparatus and the detection is performed. It is sufficiently possible to perform the above-described image processing on the black image at the boundary. By performing the boundary image processing as in the present invention, a high-quality full-color image can be achieved.

Further, in the above-described embodiment, the head in which the nozzles having a plurality of color inks are formed on the same substrate as represented in FIG. 2 has been described.
The present invention can be applied to a recording apparatus having a plurality of separate heads for each ink color as shown in FIG. 20, and it is possible to prevent border bleeding occurring between a color image and an adjacent black image.

In the above embodiment, the recording head uses an ink jet recording method in which bubbles are generated in the ink by using thermal energy generated from the electrothermal transducer, and the ink is caused to fly by the action of the bubbles. Although the description has been made, it goes without saying that the present invention can be applied to a so-called piezo-type ink jet recording system in which ink is caused to fly by causing a state change in the ink using mechanical energy generated from the electromechanical converter.

The present invention particularly provides an excellent effect in a recording apparatus using an ink jet type recording head for performing recording by forming a flying liquid by utilizing thermal energy among ink jet recording methods.

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

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

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

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

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

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

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

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

Further, the present invention relates to paper, cloth, non-woven cloth,
Applicable to all devices that use recording media such as HP paper,
Specific examples of applicable devices include a printer, a copying machine, a facsimile, and the like.

[0111]

As described above, according to the present invention, when there is a black image adjacent to a color image, all the dots of the black image adjacent to the color image are formed by mixing the color inks. This can prevent ink bleeding between colors. Further, when a black image that is not adjacent to a color image is formed continuously with black dots formed by the mixed color of the color inks, the two types of black dots are mixed and the black image is formed stepwise. Since the color tone is changed, it is possible to solve the disadvantage that the appearance due to the color difference is poor.

[Brief description of the drawings]

FIG. 1 is a perspective view of an inkjet recording apparatus to which the present invention can be applied.

FIG. 2 is a perspective view of an ink jet recording head.

FIG. 3 is a control circuit block diagram of the inkjet recording apparatus.

FIG. 4 is an operation flowchart when a black image is printed.

FIG. 5 is a diagram illustrating an example of a print image.

FIG. 6 is a diagram illustrating an example of a print image.

FIG. 7 is a diagram showing a first embodiment of an image printed by the present invention.

FIG. 8 is a diagram showing a second embodiment of an image printed according to the present invention.

FIG. 9 is a diagram showing a third embodiment of an image printed according to the present invention.

FIG. 10 is a diagram showing a fourth embodiment of an image printed by the present invention.

FIG. 11 is a diagram showing a fifth embodiment of an image printed by the present invention.

FIG. 12 is an overall image showing a sixth example of an image printed according to the present invention.

FIG. 13 is an enlarged view of an image for explaining details of a portion A in FIG. 12 and is a diagram illustrating an example of dots constituting extended pixels.

FIG. 14 is a view for explaining means for processing / forming the image printed in FIG. 13;

FIG. 15 is an overall image showing an image printed according to a seventh embodiment of the present invention.

FIG. 16 is an enlarged view of an image for explaining details of a portion B in FIG. 15 and is a diagram illustrating an example of constituent dots of extended pixels.

FIG. 17 is a diagram showing an eighth embodiment of an image printed according to the present invention.

FIG. 18 is a diagram showing a ninth embodiment of an image printed according to the present invention.

FIG. 19 is a perspective view of another head used in an ink jet recording apparatus to which the present invention can be applied.

FIG. 20 is a perspective view of still another head used in an ink jet recording apparatus to which the present invention can be applied.

[Explanation of symbols]

Reference Signs List 101 carriage 102 print head 103 cartridge 104 guide shaft 1 105 guide shaft 2 106 recording paper 107 paper feed roller 108 paper feed roller 109 paper presser plate 110 tank for color ink 111 tank for black ink 201 silicon substrate with nozzle formed 202 print substrate 203 Aluminum base plate 204 to 206 Stainless steel pipe connected to color ink tank 207 Stainless steel pipe connected to black ink tank 208 Distributor 301 System controller 302 Carriage motor driver 303 Paper feed motor driver 304 Carriage motor 305 Paper feed motor 306 Host computer 307 Receive buffer 308Y Frame memory for yellow head 308M Maze Frame memory for header head 308C Frame memory for cyan head 308Bk Frame memory for black head 309Y Data buffer for yellow head 309M Data buffer for magenta head 309C Data buffer for cyan head 309BK Data buffer for black head 310 Printing control Unit 311 print driver 100Y, 312Y yellow head 100M, 312M magenta head 100C, 312C cyan head 100BK, 312BK black head 400 black dot 401 formed by mixing a plurality of color inks, 501 black dot 402 formed by black ink 402 color ink Image (arbitrary of Y, M, C) 500 First black image 500 in an extended pixel using 4 pixels as one unit 500 Blank area where printing is not performed 502 Cyan-in (C) image / pixel 503 Magenta ink (M) image / pixel 504 Yellow ink (Y) image / pixel 510 Second black pixel 520 in extended pixel using 4 pixels as one unit Third black pixel 600 in an extended pixel with four pixels as one unit 600 Composite pixel formed by color inks Y, M, C 601 Composite pixel formed by color inks Y, C

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Nao Yaegashi 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Atsushi Arai 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inside (72) Inventor Naoji Otsuka 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Kentaro Yano 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Nobuyuki Kuwahara 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Kiichiro Takahashi 3-30-2, Shimomaruko 3-chome, Ota-ku, Tokyo Canon Inc. (72) Invention Person: Osamu Iwasaki, 3-30-2 Shimomaruko, Ota-ku, Tokyo Inside Canon Inc. (72) Inventor Daigoro Kanematsu 3-30-2, Shimomaruko, Ota-ku, Tokyo (56) References JP-A-3-146355 (JP, A) JP-A-4-158049 (JP, A) JP-A-4-192667 (JP, A) JP-A-60-141585 (Japanese) JP, A) JP-A-64-75252 (JP, A) JP-A-1-275141 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B41J 2/21 B41M 5/00

Claims (17)

(57) [Claims] 1. A color inkjet recording method for forming a desired color image on a recording material using a black ink and a plurality of color inks different from the black ink, wherein a color image exists adjacent to the black image. If there is a color image, if there is a color image, all adjacent portions of the color image in the black image are formed using black dots formed by mixing a plurality of color inks, and the black portion around the adjacent portion is formed. An image is formed by mixing black dots formed by mixing the black ink dots and the color ink. 2. When a black image around the adjacent portion is formed by mixing black ink dots and black dots formed by the color ink, the dot ratio of the black ink is gradually increased as the distance from the adjacent portion increases. 2. The method according to claim 1, wherein the color ink jet recording method is performed. 3. The color inkjet recording method according to claim 2, wherein the ratio of the black ink is gradually increased within a range of 10% to 90%. 4. The mixed range of the adjacent portion is one in five dots.
3. The ink jet recording method according to claim 2, wherein the area is equal to or more than a dot. 5. The mixed range of the adjacent portion is one for every two dots.
3. The ink jet recording method according to claim 2, wherein the area is equal to or more than a dot. 6. The color ink jet recording method according to claim 1, wherein the black image around the adjacent portion is formed by randomly mixing black ink dots and black dots formed by color ink. 7. The color ink jet recording method according to claim 1, wherein the ink is ejected by causing a state change in the ink using thermal energy generated from the electrothermal transducer. 8. The color ink jet recording method according to claim 1, wherein the ink is ejected using mechanical energy generated from the electromechanical transducer. 9. A color ink jet recording method for forming a desired color image on a recording material using a black ink and a plurality of color inks different from the black ink, wherein the color image is present adjacent to the black image. If there is a color image, a black image is set as an extended pixel in units of a plurality of pixels of a black image adjacent to the color image,
A recording method, wherein the extended pixels are processed as a black image formed by a mixture of color ink and black ink. 10. The color ink jet recording method according to claim 9, wherein the extended pixels are each composed of 4 2 × 2 pixels. 11. The color ink jet recording method according to claim 9, wherein at least two extended pixels are arranged for a black image around a color ink pixel. 12. The color ink jet recording method according to claim 9, wherein the arrangement and ratio of each ink color in the extended pixels are determined by a mask for image processing and processed as a black image. 13. The color ink jet recording method according to claim 9, wherein the ratio of each ink color in the extended pixel is determined by a mask for performing image processing so that black ink is increased stepwise. 14. The color ink jet recording method according to claim 12, wherein setting of a mask for image processing is changed according to a print mode and / or the number of print passes. 15. The color ink jet recording method according to claim 12, wherein the setting of the mask for image processing is changed according to the type of printing recording material and / or the printing environment (temperature / humidity). 16. The method according to claim 12, wherein the setting of a mask for image processing is performed by randomly arranging and / or proportioning the color and black ink in the extended pixels.
The color ink jet recording method as described above. 17. A color ink jet recording method according to claim 9, wherein said extended pixels are arranged while being rotated in a fixed direction around a color image.