JPH06152904A - Color ink-jet recording method - Google Patents

Abstract

PURPOSE:To provide high definition pictures even when the pictures of different colors are adjacent by recording the prescribed amount of the pictures of a specified color with the ink of the specified color, turning a material to be recorded back to an initial position, performing sub-scanning in an opposite direction next and recording the pictures of the other color. CONSTITUTION:When black pictures and color pictures coexist and are adjacent to each other, printing only by a black ink head is performed first, a data processing for not printing one of the black pixels of the black pictures adjacent to the color pictures or the prescribed amount of the peripheral black pixels is performed and the unprocessed black pictures are printed only by the ink head (black dot 401). After the black pictures are printed by a prescribed scanning part, the material to be recorded is inversely fed and is turned back to the initial position where the black pictures are printed. Then, unprinted black pictures are printed by the black pictures (black dot 400) formed by the color mixture of color inks, the color pictures are formed by a color ink head, printing is successively performed and the desired pictures are obtained.

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 with high density.

[0002]

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

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

[0004] In recent years, it has become possible to impart printability to plain paper by technological innovation of ink, but the quality is still insufficient.

The most prominent factor is bleeding between color inks of a color image on plain paper (so-called bleeding).

In order to prevent bleeding between color inks, inks have been developed which have a fast penetration speed with respect to plain paper and are quick-drying.

A problem here is that when the above-mentioned ink is used, ink bleeding between colors of the color image portion where the ink immediately permeates and fixes on the paper surface is prevented, It was found that the black image portion had a low print density and was not clear.

When the black image part exists independently of the color image part, the quality is particularly poor. For example, when the black image is a character, it becomes unclear characters lacking in sharpness and must be extremely poor. I didn't get it.

For this reason, it has been attempted to improve the printing quality and increase the printing density by using the type of ink having a relatively slow penetration time as the black ink used for the black image.

[0010]

However, as the color ink, one that has a high ink penetration rate to the paper surface is used.
When full-color image recording is performed using a black ink that forms a black image with a relatively slow penetration rate, especially when there is a black image in the background of the color image part, black with slow ink penetration It has been found that the ink flows into the image of the color ink to significantly deteriorate the print quality.

FIG. 11 is a conventional image when a full-color image is formed by heads having black, cyan, magenta, and yellow inks at approximately the same time or with a short time difference.

When images of different colors are adjacent to each other, color mixing or bleeding occurs between the colors, resulting in poor image quality.

The present invention has been made in view of the above points,
An object of the invention is to provide a color inkjet recording method capable of recording a high-quality image even when images of different colors are adjacent to each other.

[0014]

In order to achieve this object, the present invention provides a color ink jet recording method for forming a desired color image on a recording material by using inks of a plurality of colors. It is determined whether or not there is a color image adjacent to, and when the image of the specific color and the color image are adjacent to each other, the image of the specific color is recorded on the recording material using the ink of the specific color. Quantitative recording is performed, and then sub-scanning is performed in the reverse direction to return the recording material to the position where the recording of the image of the specific color was started, and then the image of another color is recorded to complete a desired color image. It is characterized by

As a result, after a predetermined amount of the image of the specific color is recorded using the ink of the specific color, an image of another color is recorded after a certain time.

[0016]

【Example】

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

The two ink tanks are provided in the recording head 102 and the rubber seal portions (not shown) provided in the ink tanks 110 and 111 when pushed into the insertion openings provided separately in the cartridge 103. Stainless steel pipes, etc. are 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, which is the recording material, is fed by the paper feed roller 10.
8 and 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 ink for each ink, and has a plurality of nozzles for yellow, magenta, cyan, and black inks.

The yellow, magenta, cyan, and black ejection port groups are formed on the same substrate and 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. There is a spacing equal to or greater than the nozzle pitch between the respective colors.

An ink passage for supplying ink to each of these ejection ports is provided, and an electrothermal energy converter for ejecting ink droplets is provided at an ink nozzle corresponding to each ejection port. is doing. Ink is foamed by heating the electrothermal energy converter according to the input of a 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 an ink droplet of about 40 ng for each color is ejected from a color nozzle and an ink droplet of about 80 ng is ejected from a black nozzle.
(Here, 1 ng = 10 ⁻⁹ g) ^Reference numeral 204 in the drawing is a connecting portion with the yellow tank portion of the color ink tank 110, which is made of a stainless pipe so that ink can be supplied to the head. Similarly 205
Is for cyan ink, and 206 is for magenta ink.
In addition, 207 provided on the opposite side of the ejection port of the head 102
Is a joint for the black ink 111. Reference numeral 208 denotes a distributor which is a distribution passage for the ink supplied from each ink tank. Regarding the ink used in the present invention, as described above, the color ink has a high ink permeability with respect to plain paper, and the black ink has a relatively high permeability with excellent print quality and print density. You are using slow-acting ink.

Specifically, the 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 balance is used, but it is not limited to this, and color ink has a high ink penetration speed to the paper surface. Any black ink may be used as long as printing quality and printing density are emphasized for the black ink and one having a relatively low permeability to the paper surface is used.

FIG. 3 is an electrical control block diagram of the color ink jet printer described above. Reference numeral 301 in the figure denotes a system controller for controlling the entire apparatus, including a storage element (ROM) in which a control program including a microprocessor is stored, and a storage element (RAM) used when the microprocessor performs processing. ) Etc. are arranged. Reference numeral 302 is a driver for driving the print head 102 in the main scanning direction, and similarly 303 is a driver for moving the paper in the sub scanning direction. 304, 3
Reference numeral 05 denotes a motor corresponding to the driver, which operates by receiving speed, moving distance, etc. from the driver. 306 is
The host computer is a device for transferring information to be printed to the printing device of the present invention.

Reference numeral 307 is a reception buffer for temporarily storing data from the host computer,
Data is accumulated until the data is read from the 301 system controller.

Reference numeral 308 is a frame memory for expanding the data to be printed into image data, and has a memory size required for printing.

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

Reference numeral 309 denotes a storage element for temporarily storing the data to be printed, and the storage capacity changes depending on the number of nozzles of the print head.

Reference numeral 310 denotes a print control unit for appropriately controlling the print head according to a command from the system controller, and a print control unit for controlling the ejection timing, the number of print data, and the like.

Reference numeral 311 denotes heads 312Y and 3Y for each color.
A driver for driving 12M, 312C, and 312Bk, which is controlled by a signal from the print control unit 310.

FIG. 4 is a flow chart for explaining the recording operation of the embodiment of the present invention.

<Step 1> is the host computer 3
06, the data stored in the reception buffer 307 is transferred to the system controller 30 of 301.
1 is the first step to process and reads the stored data.

In <Step 2>, it is determined whether the read image data includes black data or data other than black. If black data is included, the process proceeds to step 3, otherwise 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, and if it is bit image data, Go to step 5.

At <Step 4>, attention is paid to black data, and it is determined whether or not there is color recording data 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, and if not, the process proceeds to step 6.

In <Step 5>, the black image information which is the character code data and the color image exists at the adjacent position or the black image information which is the bit image data is the buffer for yellow, magenta and cyan for color recording. Be deployed to.

In <Step 6>, the black image information is expanded in the black recording buffer.

In <Step 7>, as will be described later, image data processing for mixing black dots of C, M, and Y color inks and black dots of black inks is performed on the black data.

In <Step 8>, the data of each color is expanded in the 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 determination, if there is no print data, or if there is print data but one page of data has already been received, the process proceeds to step 10. Otherwise, return to step 1.

In <Step 10>, the recording head 102
To start the printing operation.

FIG. 5 shows an image printed according to the present invention.

FIGS. 6A to 6D are for explaining the printing steps when obtaining the image of FIG.

As described above, when it is recognized that the black image and the color image are mixed and adjacent to each other, the image is formed by the following printing steps.

In FIG. 6 (a), data is printed by using only the black ink head first, and one black pixel of the black image adjacent to the color image or a predetermined amount of black pixels around the black pixel is not printed. The unprocessed black image is printed only by the ink head (black dot 401).

After the black image is printed for a predetermined number of scans, the recording material is reversely fed back to the initial position where the black image was printed.

In FIG. 6B, next, the black image not printed by the black image is printed by the black image (black dot 400) formed by the color mixture of the color inks.
A color image is formed by a color ink head to obtain a predetermined image.

Thereafter, as shown in FIGS. 6 (c) and 6 (d), printing is sequentially performed to obtain a desired image.

As described above, when the black image and the color image are mixed and adjacent to each other, the above-mentioned printing is performed, but when only the black image or only the color image is used, the normal printing is performed.

(Embodiment 2) Next, another embodiment of the present invention will be described.

In the second embodiment, printing is performed by using a recording head in which a black ink head and a color ink head are separately formed.

FIG. 7 is a perspective view of the ink jet recording head used in this embodiment, which is a black ink head 100Bk.
Have 64 discharge ports and are arranged in a straight line. Further, the yellow 100Y, magenta 100M, and cyan 100C of the color ink head each have 24 ejection ports and are arranged in a straight line in the vertical direction. The respective colors are formed integrally with each other with a space equal to or larger than the nozzle pitch.

The black ink head 100Bk has a larger ink ejection amount than the other color inks, as described in the first embodiment. Specifically, about 80 ng (1 n
g = 10 ⁻⁹ g), and the ink used has relatively low permeability to the recording material in order to obtain high print quality.

In addition, the color ink heads 100Y to 1
00C is designed so that the ejection amount thereof is about 40 ng, and the ink used has a high permeability to the recording material.

The printing steps in this embodiment will be described below.

As described above, when it is recognized that a black image and a color image are mixed and adjacent to each other, the following FIG.
An image is formed by the printing steps (a) to (e).

FIG. 8A is a desired printed image formed by the present invention.

In FIG. 8B, when a desired image is first divided into a black image and a color image and data processing is performed, and only the black data is printed by a black ink head for a predetermined amount of scanning, Is the printing state.

In some cases, the entire black image for one page may be printed.

After the black image has been printed by a predetermined amount of scanning, the recording material is reversely fed back to the initial position where the black image was printed.

In FIG. 8 (c), the remaining color image not printed in the above (b) is formed with a color ink head to obtain an image.

A desired image can be obtained by repeating printing as shown in FIGS. 8 (d) and 8 (e) to form an image.

As described above, when the black image and the color image are mixed and adjacent to each other, the black ink of the initially printed black image is sufficiently fixed on the recording material by performing the printing as described above. Since the next color image is printed later, a high-quality color image can be obtained without causing color mixing or bleeding even when adjacent to the color ink.

Further, when only a black image or only a color image is provided, normal printing is performed.

(Embodiment 3) Next, still another embodiment of the present invention will be described.

In the third embodiment, printing is performed by using a recording head in which a black ink head and a color ink head are separately formed. A black image and a color image (2 An example when the next color is adjacent will be described.

FIG. 9 is a perspective view of an ink jet head used in this embodiment. The heads are prepared for each ink color, and four heads 100Bk for yellow, cyan, and magenta inks as well as black inks are used. -100C.

Each head has 64 ejection ports and is arranged in a straight line. Further, the black ink head 100Bk has a larger ink ejection amount than other color inks as described in the first embodiment, and specifically, about 80 ng (1 ng = 10 ⁻⁹ g). It is designed so that the discharge amount can be obtained. In order to obtain high print quality, the ink used has relatively low permeability to the recording material.

In addition, the color ink heads 100Y to 1
00C is designed so that the ejection amount thereof is about 40 ng, and the ink used has a high permeability to the recording material.

The printing steps in this embodiment will be described below.

When it is recognized that a desired image is adjacent to a black image and a color image formed by superimposing a plurality of color inks (secondary colors), the following printing steps shown in FIGS. 10B and 10C are performed. Form an image.

FIG. 10A shows a desired print image formed by this embodiment.

In FIG. 10B, first, data processing for dividing a desired image into an image 403 in which a black image and a plurality of color inks are superposed is divided into a single color image, and the black data and the single color of the adjacent color image are processed. Only the (primary color) 404 is printed for a predetermined amount of scan.

In some cases, the entire black image for one page may be printed.

Here, the case where the secondary color image 403 adjacent to the black ink 401 is green is taken as an example.

The secondary color green 403 is cyan,
Since the yellow ink is formed by mixing colors, each of them is printed at different timing.

First, the black ink 401 and the cyan ink 404 of the temporary color are simultaneously printed on the recording material.

Here, the effect is further improved by using a cyan ink having a better fixing property than the yellow ink.

After printing is performed for a predetermined amount of scanning, the recording material is reversely fed back to the initial position of printing.

In FIG. 10 (c), next, the remaining color ink printed in (b) above is printed on the monochromatic color image to form a color image, and then the remaining color image is printed. The desired image can be obtained with.

That is, here, the yellow ink is printed at the same position where the cyan ink is recorded to form the secondary color green. Further, the remaining images are simultaneously printed by the color ink head.

Hereinafter, as shown in FIGS. 10D and 10E, printing is sequentially performed to obtain a desired image.

Therefore, when the black print and the monochromatic color print are adjacent to each other, the advantage that the ink amount is smaller than the secondary color of the color and the color mixing is small can be utilized. Since the color image of is printed, it is possible to obtain a high-quality color image with minimal color mixture and bleeding between colors.

Further, when only a black image or only a color image is used, normal printing is performed.

As described above, according to the present embodiment, when there is a black image in the background of the color image, that is, when there is a black image adjacent to the color image, the black image and the color image are timed. It was found that ink can be prevented from flowing by providing a print.

That is, since the color ink image is formed after the black ink of the black image is fixed (permeated and dried) on the recording material, a high-quality image can be obtained without the inflow of ink.

Even if the printed images are formed in the reverse order, substantially the same effect can be obtained.

Further, in the above embodiment, the recording head uses the ink jet recording method in which the thermal energy generated from the electrothermal converter is used to generate bubbles in the ink and the ink is ejected by the action of the bubbles. As described above, it is needless to say that the present invention can be applied to a so-called piezo type inkjet recording system in which the ink is ejected by causing a state change in the ink by using mechanical energy generated from the electromechanical transducer.

The present invention is also applicable to paper, cloth, non-woven fabric, and O
Applicable to all devices that use recording media such as HP paper,
Specific applicable devices include printers, copying machines, facsimiles, and the like.

[0091]

As described above, when there is an image of a specific color adjacent to a color image, first, a predetermined amount of the image of the specific color is recorded with the ink of the specific color, and then sub-scanning is performed in the reverse direction. By returning the recording material to the original position and then recording an image of another color to obtain a desired image, color mixing and bleeding between colors can be prevented and a high-quality image can always be obtained.

[Brief description of drawings]

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

FIG. 2 is a perspective view of the ink jet recording head used in the first embodiment of the present invention.

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

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

FIG. 5 is a diagram showing an example of an image printed by the recording apparatus of the present invention.

FIG. 6 shows printing steps for obtaining an image in the first embodiment of the present invention.

FIG. 7 is a perspective view of a head used in a second embodiment of the present invention.

FIG. 8 is a diagram showing printing steps for obtaining an image in the second embodiment of the present invention.

FIG. 9 is a perspective view of a head used in a third embodiment of the present invention.

FIG. 10 is a diagram showing printing steps for obtaining an image in the third embodiment of the present invention.

FIG. 11 occurs when a conventional full-color image is obtained,
FIG. 6 is a diagram showing an example of a printed image for explaining color mixing between different color inks and bleeding.

[Explanation of symbols]

100Bk Black ink head 100Y Yellow ink head 100M Magenta ink head 100C Cyan ink head 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 press plate 110 For color ink Tank 111 Tank for black ink 201 Silicon substrate on which nozzle is formed 202 Printed circuit board 203 Aluminum base plate 204 to 206 Stainless pipe connected to color ink tank 207 Stainless 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 Reception buffer 308Y Frame memory for yellow head 308M Frame memory for magenta head 308C Frame memory for cyan head 308Bk Frame memory for black head 309Y Data buffer for yellow head 309M Maze Data buffer 309C for cyan head data buffer 309Bk data buffer for cyan head 309Bk data buffer for black head 310 print control unit 311 print driver 312Y yellow head 312M magenta head 312C cyan head 312Bk black head 400 formed by mixing multiple color inks Black dot or image 401 Black ink black dot or image 402 Color ink dot Or image 403 Dot or image of color ink in which two colors overlap with each other, or a dot or image of primary color obtained by dividing the secondary color of 404 403 into a single color.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Nao Yaegashi 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc.

Claims (11)

[Claims] 1. A color inkjet recording method for forming a desired color image on a recording material using a plurality of color inks, determining whether or not a color image is present adjacent to a specific color image, When the image of the specific color and the color image are adjacent to each other, a predetermined amount of the image of the specific color is recorded on the recording material by using the ink of the specific color, and then the sub-scanning is performed in the reverse direction so that the recording material A color ink jet recording method comprising returning to a position where recording of the image of the specific color is started, and then recording an image of another color to complete a desired color image. 2. A desired color image is formed on a recording material using black ink and a plurality of color inks different from the black ink, wherein the specific color is black. The color inkjet recording method according to claim 1. 3. The color ink jet recording method according to claim 2, wherein in the case of only a black image, the image is recorded using black ink. 4. The color ink jet recording method according to claim 2, wherein in the case of only a color image, the image is recorded using the plurality of color inks. 5. When the black image and the color image are adjacent to each other, at least one black pixel adjacent to the color pixel in the black image or a black image excluding a predetermined amount of black pixels around the color image is removed. A predetermined amount of the black ink is recorded on the recording material, then the sub-scanning in the reverse direction is performed, and then a black image and a color image which are not recorded with the black ink using a plurality of color inks are recorded on the recording material. The color inkjet recording method according to claim 2, wherein recording is performed on a recording material. 6. When a black image and a color image in which a plurality of color inks are overlapped are adjacent to each other, a single color image of the black image and the color image is recorded on a recording material, and then the sub-scanning in the reverse direction is performed. The color ink jet recording method according to claim 2, wherein the remaining color image of the color image is recorded on the recording material. 7. A black ink ejection head and a plurality of color ink ejection heads are integrally formed to reciprocate in a main scanning direction to perform recording, and at the same time, the black ink ejection head and the color ink are ejected. The color inkjet recording method according to claim 2, wherein the ejection head is arranged in the sub-scanning direction perpendicular to the main scanning direction. 8. A black ink ejecting head and a plurality of color ink ejecting heads are separately configured, and recording is performed using a recording unit in which the two heads are arranged in parallel. The color inkjet recording method described in. 9. A black ink ejection head and a plurality of color ink ejection heads are separately configured, and recording is performed using a recording unit in which the heads of the respective colors are arranged in parallel. 2. The color inkjet recording method described in 2. 10. The color ink jet recording method according to claim 1, wherein the ink is ejected by causing a state change in the ink by using thermal energy generated from the electrothermal converter. 11. The color ink jet recording method according to claim 1, wherein the ink is ejected by causing a state change in the ink by using mechanical energy generated from the electromechanical transducer.