JPH06152900A - Color ink jet recording method - Google Patents

Abstract

PURPOSE:To obtain a picture without ink blotting between the respective pictures by permitting the jet timing difference of black ink and color ink in the adjacent part of the black picture and the color picture to be longer than that in the non-adjacent part. CONSTITUTION:Data is transferred from a host computer 306 and data stored in a reception buffer 307 is read by a system controller 301. Black color a data within read data is taken into consideration and the black picture is extended in the buffer for respective kinds of color unless color picture data adjacent to black picture data exists so that recording is operated by a recording head for respective kinds of color. When the black picture is adjacent to the color picture, recording is operated by the recording head for black ink after picture data of respective kinds of color is extended in the buffer. At this time, the head for color ink is not operated. After a recording operation is completed, a carriage is returned to an original position and, moreover, the stand-by time of prescribed time is set. Then, the recording of the color picture being adjacent to the black picture is operated.

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, and more specifically, color inks such as yellow, magenta, cyan, or green, red, blue, etc. And a color ink jet recording method using a black ink such as black. The present invention can be applied to all devices that use recording media such as paper, cloth, non-woven fabric, and OHP paper, and specific applicable devices include office equipment such as printers, copying machines, and facsimiles, and mass production equipment.

[0002]

2. Description of the Related Art Ink jet recording methods are used in printers, copying machines and the like because of their low noise, low running cost, easy downsizing of devices, and easy colorization.

By the way, when the ink jet recording method is applied to a color recording apparatus, it has been necessary to use a special paper in order to obtain a color image of high color development without ink bleeding. Those that are suitable for printing on paper have been put into practical use. However, the current printing quality is still at an insufficient level. The most important factor is the black image quality in the color image.

[0004]

Usually, when a color image is obtained on a plain paper by an ink jet recording method, a quick-drying ink having a high penetration speed into the plain paper is used, and therefore the color image portion has an ink between colors. Although a high-quality image with no bleeding is produced, the black image portion has a low density, and so-called feathering occurs in which ink bleeds along the fibers of the paper. For example, when there is a black image in the color image part as a background, the above-mentioned problems of the black image part are relatively inconspicuous and do not significantly deteriorate the quality, but the black image part is different from the color image part. When it exists independently, it is degrading. Furthermore, when the black image is a character, it becomes an unclear character lacking sharpness, and therefore the quality is unavoidably poor.

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

The present invention has improved the above-mentioned drawbacks of the prior art. Even in the case of an image in which a black image and a color image are mixed, the density is high and a black image without feathering, and between the color images or between the black images. Another object of the present invention is to provide a color inkjet recording method capable of obtaining a high-quality image in which ink bleeding does not occur between a color image and a color image.

[0007]

Means and Actions for Solving the Problems A means for achieving this is a color ink for forming a desired color image on a recording medium by ejecting black ink and a plurality of color inks different from the black ink onto the recording medium. In the inkjet recording method, it is determined whether or not there is a color image adjacent to the black image, and the ejection timing difference between the black ink and the color ink at the adjacent portion between the black image and the color image is determined as It is characterized in that it is set to be longer than the driving timing difference in the adjacent portion. This can prevent ink bleeding between the black image and the color image.

Further, when the black image and the color image are adjacent to each other, a part or all of the black image is formed by a plurality of color inks.

Yellow is used as the color ink of a plurality of colors,
Magenta and cyan inks can be used.

[0010]

First, an outline of an embodiment of the present invention will be described.

FIG. 1 is an example showing an image in which a black image and a color image are mixed. In FIG. 1A, the black image is not adjacent to the background yellow image, while in FIG. 1B, the black image is adjacent to the background yellow image.

In one embodiment of the present invention, it is determined whether or not a color image is present adjacent to a black image, and if there is, a black image is printed when the adjacent portion of the black image and the color image is printed. The difference in the ejection timing between the black ink for forming and the color ink for forming the color image is set longer than the difference in the ejection timing in the non-adjacent portions of the black image and the color image.

Therefore, the image shown in FIG. 1A is, for example, as shown in FIG.
As shown in (a), when a black ink recording head for ejecting black ink and a yellow ink recording head for ejecting yellow ink are simultaneously scanned on a recording medium, both recordings are performed by one scanning. Ink corresponding to image information is ejected from the head. On the other hand, in the image of FIG. 1B, both recording heads are simultaneously scanned as shown in FIG. 2B, but only the black ink is ejected in the first scan to form a black image, and then the image of FIG. As shown in 2 (c), only the yellow ink is ejected in the second scanning to form a yellow image. In this case, a waiting time may be set before the start of the second scanning, if necessary.

As described above, in the adjacent portion between the black image and the color image, the timing difference between the black ink for forming the black image and the color ink for forming the color image is set to the timing difference in the non-adjacent portion. By setting it longer than this, it is possible to prevent ink bleeding between the black image and the color image.

Next, a recording method which is a further development of the above embodiment will be described.

When the black image and the yellow image of the background portion are adjacent to each other as shown in FIG. 1B, the black image near the adjacent portion of the black image and the color image is formed by a plurality of color inks. Figure 3
Shows an example thereof, in which only the outermost portion of the black image adjacent to the yellow image (pixels hatched in the figure) is formed with color ink. Therefore, in this case, first, as shown in FIG. 4A, only the black image is formed by the black ink recording head for ejecting the black ink.
Then, by the second scanning, yellow, magenta, and cyan inks are applied to the hatched pixels in FIG. 3 to form a black image, and at the same time, a yellow image which is a background portion of the black image is formed.

In this method, it is possible to set the ejection timing difference between the black ink and the color ink to be shorter than that in the method of forming the black image only with the black ink. The reason is as follows. That is, in this method, as shown in FIG.
The black image formed by the color ink in the hatched portion and the black image formed by the black ink inside the hatched portion are printed by separate scanning as shown in FIG. However, since the black image formed by the color ink and the black image formed by the black ink are not conspicuous even if ink bleeding occurs, the difference in the driving timing can be set to be short.

In FIG. 3, the black image formed by the color ink is described as having only one pixel in the adjacent portion, but it may have more pixels than necessary.

Further, although the case where the recording heads are arranged in a horizontal row has been described with reference to FIGS. 2 and 4, the arrangement of the recording heads and the structure of the recording heads are not limited to these.

The basic concept of the embodiments of the present invention has been described above, and each embodiment will be described in more detail below with reference to the drawings.

(Embodiment 1) FIG. 5A shows a schematic view of a printer to which a color ink jet recording method to which the present invention is applicable is applied. 1y is a recording head for yellow ink and 1m is for magenta ink. A printhead, 1c is a printhead for cyan ink, 1k is a printhead for black ink, 2 is a carriage on which the printhead is mounted, 3 is a flexible cable for sending electric signals from the printer body to the printhead, and 4 is recovery means. The cap units 5y, 5m, 5c and 5k have recording heads 1y, 1m,
1c and 1k are cap members, 6 is a wiper blade made of rubber or the like, and 7 is a recording paper which is held facing the recording head.

FIG. 5 (b) is a schematic diagram of a printer mounted on the printer.
One of two recording heads is shown, and 64 ejection ports 2 are formed at a density (360 dpi) per inch in a portion where the recording head faces the recording paper. Each of these ejection ports 10 is provided with an ink liquid passage communicating with the ejection port, and a common liquid chamber for supplying ink to these liquid passages is provided behind the portion where the ink liquid passage is arranged. It is provided. The ink liquid path corresponding to each of the ejection ports is provided with an electrothermal converter that generates thermal energy used to eject ink droplets from these ejection ports, and an electrode wiring for supplying electric power to the electrothermal converter. Has been.

About 40 ng of ink is ejected from the ejection ports of the recording heads 1y, 1m, and 1c, and about 80 ng of ink is ejected from the ejection port of the recording head 1k at a frequency of 5.4 KHz.

As the color inks to be supplied to the recording heads 1y, 1m, 1c, those which have a high penetration speed into the recording paper are used so as not to cause ink bleeding at color boundaries when forming a color image, On the other hand, as the black ink to be supplied to the recording head 1k, the permeation speed into the recording paper is relatively high as compared with the above three types of color inks so that the black image has high density and high quality with less feathering. The slower one is used.

Specifically, the inks of the following components were used as the inks of the respective colors.

(Yellow) C.I. I. Direct Yellow 86 3 parts Diethylene glycol 10 parts Isopropyl alcohol 2 parts Urea 5 parts Acetynol EH (Kawaken Chemical) 1 part Water balance

(Magenta) C.I. I. Acid Red 289 3 parts Diethylene glycol 10 parts Isopropyl alcohol 2 parts Urea 5 parts Acetinol EH (Kawaken Chemical) 1 part Water balance

(Cyan) C.I. I. Direct Blue 199 3 parts Diethylene glycol 10 parts Isopropyl alcohol 2 parts Urea 5 parts Acetinol EH (Kawaken Chemical) 1 part Water balance

(Black) C.I. I. Direct black 154
3 parts Diethylene glycol 10 parts Isopropyl alcohol 2 parts Urea 5 parts Acetinol EH (Kawaken Chemical) 1 part Water balance

FIG. 6 is an electrical control block diagram of the color ink jet printer described above.

Reference numeral 301 denotes a system controller for controlling the entire apparatus, which has a storage element (RO) in which a control program including a microprocessor is stored.
M), a memory element (RAM) and the like used when the microprocessor performs processing are arranged. Reference numeral 302 denotes a driver for driving the print head in the main scanning direction,
Similarly, 303 is a driver for moving in the sub-scanning direction. Reference numerals 304 and 305 denote motors corresponding to the driver, which operate by receiving information such as speed and movement distance from the driver.

A host computer 306 is a device for transferring information to be printed to the printing device of the present invention. Reference numeral 307 denotes a reception buffer for temporarily storing data from the host computer.
The data is accumulated until the data is read from the system controller 01. Reference numeral 308 is a memory for expanding the data to be printed into image data, and has a memory size for printing. Reference numeral 309 denotes a storage element for temporarily storing data to be printed, and the storage capacity changes depending on the number of nozzles of the print head. 310
Is to control the print head properly by the command from the system controller.
A print control unit for controlling the number of print data and the like. Three
Reference numeral 11 denotes a driver for driving the heads of 312Y, 312M, 312C and 312Bk, which is controlled by a signal from the print control unit 310.

FIG. 7 shows the operation flow of this embodiment.

In STEP 1, data is transferred from the host computer 306 shown in FIG. 6, and the system controller 301 reads the data stored in the reception buffer 307. In STEP 2, attention is paid to black data among the read data, and it is determined whether or not color recording data exists at a position adjacent to the periphery of the black image recording area. If there is no color image data adjacent to the black image data, the process proceeds to STEP 3, and if it exists, the process proceeds to STEP 6.

In STEP 3, the color image data of the black image is developed in the buffer for each color, and in STEP 4, the recording operation is performed by the recording heads for yellow, magenta, cyan, and black ink. Further, in STEP 5, the recording paper is fed by 64 nozzles, and the carriage on which the recording head is mounted returns to the original position for the next scanning.

On the other hand, when the black image and the color image are adjacent to each other, in STEP 6, the image data of each color is developed in the buffer, and in STEP 7, the recording operation for only the black image is performed by the recording head for black ink. At this time, no ink is ejected from the recording head for color ink. After the recording operation is completed, in STEP 8, the carriage returns to the original position, and a waiting time of 3 seconds is set. At this time, the recording paper is not fed. In STEP 9, the recording operation of the color image adjacent to the black image is performed by the color ink recording head for each color, and after the recording operation is completed, the recording paper is fed by 64 nozzles in STEP 10.

At STEP 11, the data is read from the reception buffer and it is determined whether there is data to be printed. If there is data to be printed, the process returns to STEP1, and if there is no data, the process ends.

As described above, according to this embodiment, STEP7 to S7
By the TEP 10, the formation of the black image and the formation of the color image are performed in separate scans in the adjacent portions of the black image and the color image, and further, the carriage is returned between the end of the recording of the black image and the start of the recording of the color image. Since the waiting time of 3 seconds is set in addition to the time, it is possible to form a clear image in which the black image and the color image are adjacent to each other without ink bleeding.

(Embodiment 2) FIG. 8 is a schematic view of another color ink jet printer to which the present invention can be applied.

The carriage 101 has a print head 102 and a cartridge guide 103 mounted thereon, and can scan on a guide shaft 104 and a guide shaft 105. The recording paper 106 is fed into the main body by a paper feed roller 107, sandwiched by a paper feed roller 108, a pinch roller (not shown), and a paper pressing plate 109, and sent to the front surface of the paper feed roller 102 for printing. . The ink cartridges are a color ink cartridge 110 containing three colors of yellow, magenta and cyan, and a black ink cartridge 11
One of them is inserted into the cartridge 103 and the other is connected to the print head 102. The yellow, magenta, and cyan inks stored in the color ink cartridge 110 were the same as in Example 1.

The print head 102 will be described in detail with reference to FIG. 9. Yellow, magenta, cyan, and black ejection port groups are arranged in a straight line on the front surface of the print head 102. Each group has 24 ejection ports for yellow, magenta, and cyan, and 64 ejection ports for black, and has an interval of 8 nozzles between colors and an interval of 16 nozzles between black and colors. In addition, these nozzles have a density of 360 nozzles per inch (360 dp
i).

Each of these ejection ports is provided with an ink liquid passage communicating with the ejection port, and a common liquid for supplying ink to these liquid passages is provided behind the portion where the ink liquid passage is provided. A room is provided. The ink liquid path corresponding to each of the ejection ports is provided with an electrothermal converter that generates thermal energy used to eject ink droplets from these ejection ports, and an electrode wiring for supplying electric power to the electrothermal converter. Has been.
These electrothermal converters and electrode wirings are formed by a film forming technique on a 201 substrate made of silicon or the like. Further, the discharge port, the ink liquid passage, and the common liquid chamber are formed by stacking a partition wall made of resin, a glass material, a top plate, etc. on the substrate. Further on the rear side, there is provided a driving circuit printed circuit board for driving the electrothermal converter based on a recording signal.

The silicon substrate and the printed circuit board 202 are the same aluminum plate 203 in parallel with each other, and the protruding pipe 2
Reference numerals 04 to 207 project from a plastic member 208 called a distributor that extends in a direction perpendicular to the silicon substrate, and further communicates with a flow channel inside thereof, which flow channel communicates with a common liquid chamber.

There are four channels in the distributor, one for yellow, one for magenta, one for cyan, and one for black, and each common liquid chamber is connected to a pipe.

Approximately 40 ng from the yellow, magenta, and cyan discharge ports provided on the print head 102.
Of the ink of about 80 ng is ejected from the ejection port for black at a frequency of 5.4 KHz.

The print head 102 has 24 ejection openings for yellow, magenta, and cyan, respectively, while it has 64 ejection openings for black. This is because when black-only images are continuous, high-speed printing is performed by using all the black nozzles. In the case of an image in which color images are mixed, the same as the color ejection port 24 Printing is performed using individual nozzles.

FIG. 10 illustrates the recording operation when printing a color image (including a mixture of black images) using the print head 102.

FIG. 10A shows an image in which a black image has "Y" printed with yellow ink, "M" printed with magenta ink, and "C" printed with cyan ink. The process of printing this image will be described below.

In FIG. 10B, a black image is printed by the nozzle (ejection port) for black ink. Twenty-four nozzles are used, counting from the top in the figure. After completion of printing, the recording paper is fed by 24 nozzles, and a black image is further printed by the nozzles for black ink as shown in FIG. Then, after feeding the recording paper by 24 nozzles, as shown in FIG. 10D, a black image is printed by the nozzles for the black ink and a part of "C" is printed by the nozzles for the cyan ink. . Then, after feeding the recording paper by 24 nozzles, as shown in FIG. 10E, a black image is printed by the black ink nozzle and a part of "C" is printed by the cyan ink nozzle.

Then, after feeding the recording paper by 24 nozzles, as shown in FIG. 10 (f), the remaining portion of "C" by the nozzle for cyan ink and the portion of "M" by the nozzle for magenta ink are set. Print a part (corresponding to the upper half). Then, after feeding the recording paper by 24 nozzles, as shown in FIG. 10G, a part of “M” (corresponding to the lower half) of the magenta ink nozzle and a “Y” nozzle of the yellow ink are printed. Print a part of "". Then, after feeding the recording paper for 24 nozzles, as shown in FIG. 10 (h), a part of “Y” is printed by the nozzle for the yellow ink, and after feeding the recording paper, FIG.
As shown in (i), the nozzle for yellow ink is "Y".
The rest of is printed, and printing of all images is completed.

As is clear from the above recording operation, when the recording head used in the present embodiment is used, the color image which is closest to the black image earliest is the cyan image. There is a timing difference of 1 scan in the scan for printing. Therefore, in the present embodiment, only by performing the recording operation shown in FIG. 10, it is possible to obtain substantially the same effect as the contents performed in STEP 7 to STEP 10 of the first embodiment.

The electric control of the color ink jet printer used in this embodiment is the block diagram shown in FIG. 6 as in the first embodiment.

FIG. 11 shows the operation flow of this embodiment.
The basic flow is the same as that of the first embodiment, and the same steps are denoted by the same reference numerals. The operation is different from that of the first embodiment when a color image is present adjacent to a black image. That is, in the first embodiment, after recording the black image only, the recording paper is not sent and the color image is recorded in the next scanning, whereas in the present embodiment, the black image and the color image are simultaneously recorded in STEP 12. . After that, in STEP 13, the recording paper is sent and the carriage is returned, and in STEP 14, the process waits for 3 seconds. The other processing is the same as that of the first embodiment, and thus the description thereof is omitted.

As described above, also by using this embodiment, it is possible to form a high-quality image in which the bleeding of ink does not occur in the adjacent portion between the black image and the color image.

In this embodiment, when the color image is adjacent to the black image, the waiting time of 3 seconds is uniformly set regardless of the color of the color image.
As is clear from the recording operation of 0, the time required to be adjacent to the black image is short in the order of cyan, magenta, and yellow. Therefore, for example, the waiting time may be set differently depending on the color, or the waiting time may be different depending on which position of the black image is adjacent to the color image even if the color image is the same.

(Embodiment 3) Embodiment 3 is a modification of Embodiment 2.

FIG. 12 shows the operation flow of this embodiment.

Since STEP 1 to STEP 5 are the same as those in the second embodiment, their explanations are omitted.

In STEP 15, black image data of adjacent portions of the black image and the color image (pixels shown by hatching in FIG. 3)
To the respective buffers for yellow, magenta, and cyan ink. For color images, the data of each color is expanded in the buffer corresponding to each color. In STEP 16, the black image data other than the portion adjacent to the color image is developed in the black ink buffer. ST
The recording operation is performed in EP17, and the carriage is returned to the original position and the recording paper is fed in STEP18. STEP19
Then, a waiting time of 1.5 seconds is set before starting the next scan.

In the present embodiment, the black image at the boundary formed by the color ink does not cause ink bleeding even when it comes into contact with the color image. On the other hand, ink bleeding occurs at the boundary between the black image formed by the color ink and the black image formed by the black ink, but it is not conspicuous because the black images are adjacent to each other. There is no problem in practical use if a waiting time of 2 seconds is provided.

As described above, according to the present embodiment, the waiting time can be set shorter than that of the second embodiment, so that the recording speed is improved.

(Other Embodiments) Of the black images adjacent to the color image, the black image formed by the color ink is not limited to the above-mentioned embodiment, and pixels hatched as shown in FIG. 13 may be used. It may be formed of color ink. Further, the black image adjacent to the color image may be formed entirely of color ink, and in this case, the waiting time can be set shorter and the effect of preventing ink bleeding is further enhanced.

As for the structure of the recording heads, for example, the arrangement of four recording heads may be arranged in one vertical line instead of one horizontal line as in the first embodiment. Alternatively, as shown in FIG. 13, yellow and magenta may be arranged. The cyan ink recording heads may be arranged in a horizontal row and the black ink recording heads may be arranged in a staggered manner to obtain the same effect as that of the second or third embodiment.

Further, if the recording head used in the second embodiment is used and the black nozzle located further away from the cyan ink nozzle is used, the timing difference when recording the cyan image and the black image becomes long. Therefore, it is possible to obtain a further effect.

Further, in the embodiment, the so-called bubble jet recording method, in which bubbles are generated in the ink by the electrothermal converter and the ink is ejected by the action of the bubbles, the ink is ejected by the electromechanical converter. It goes without saying that the present invention can also be applied to a so-called piezo type inkjet recording system for flying.

The present invention brings excellent effects particularly in a recording head and a recording apparatus of a system which utilizes thermal energy among ink jet recording systems.

With regard to its typical structure and principle, see, for example, US Pat. Nos. 4,723,129 and 4740.
What is done using the basic principles disclosed in 796 is preferred. This method is a so-called on-demand type,
It can be applied to any of the continuous types, but in particular, in the case of the on-demand type, it is arranged corresponding to the sheet or the liquid path in which the liquid (ink) is held, to the electrothermal converter, By applying at least one drive signal that corresponds to the recorded information and gives a rapid temperature rise exceeding nucleate boiling, heat energy is generated in the electrothermal converter, and the film is boiled on the heat acting surface of the recording head. As a result, bubbles can be formed in the liquid (ink) in a one-to-one correspondence with this drive signal, which is effective. The liquid (ink) is ejected through the ejection openings by the growth and contraction of the bubbles to form at least one droplet. If this drive signal is made into a pulse shape, the growth and contraction of bubbles will be performed immediately and appropriately,
In particular, it is possible to achieve ejection of liquid (ink) with excellent responsiveness,
More preferable. As the pulse-shaped drive signal, U.S. Pat. Nos. 4,463,359 and 4,345,262 are used.
Those described in the specification are suitable. If the conditions described in US Pat. No. 4,313,124 of the invention relating to the rate of temperature rise on the heat acting surface are adopted, more excellent recording can be performed.

As the constitution of the recording head, in addition to the combination constitution of the ejection port, the liquid passage, and the electrothermal converter (the straight liquid passage or the right-angled liquid passage) as disclosed in the above-mentioned respective specifications, US Pat. No. 4,558,333, US Pat. No. 4,558,333, which discloses a configuration in which a heat acting portion is arranged in a bending region.
The structure using the specification of No. 59600 is also included in the present invention. In addition, Japanese Laid-Open Patent Publication No. 123670/1984 discloses a configuration in which a common slit is used as a discharge portion of the electrothermal converter for a plurality of electrothermal converters, and an opening for absorbing a pressure wave of thermal energy. The present invention is also effective as a configuration based on Japanese Patent Laid-Open No. 138461/1984, which discloses a configuration that corresponds to the discharge portion.

[0069]

As described above, according to the present invention, it is possible to reduce the color blur of the black ink and other color inks (yellow, magenta, cyan) while maintaining the quality of the black image.

[Brief description of drawings]

FIG. 1 is a diagram showing an example of an image for explaining the present invention.

FIG. 2 is a diagram showing an example of a recording operation for explaining the present invention.

FIG. 3 is a diagram illustrating an example of a processed image for describing the present invention.

FIG. 4 is a diagram showing an example of a recording operation for explaining the present invention.

FIG. 5 is a diagram showing a printer used in the first embodiment and an enlarged view of a recording head.

FIG. 6 is a block diagram of a control circuit of the printer used in the first embodiment.

FIG. 7 is a flowchart showing the operation of the first embodiment.

FIG. 8 is a diagram showing a printer used in a second embodiment.

FIG. 9 is a diagram illustrating a recording head used in a second embodiment.

FIG. 10 is a diagram illustrating a recording operation performed by the recording head used in the second embodiment.

FIG. 11 is a flowchart showing the operation of the second embodiment.

FIG. 12 is a flowchart showing the operation of the third embodiment.

FIG. 13 is a diagram showing an example of a processed image that can be used as another embodiment.

FIG. 14 is a diagram showing a configuration of a recording head that can be used as another embodiment.

[Explanation of symbols]

101 carriage 102 print head 103 cartridge 106 recording paper 110 color ink cartridge 111 black ink cartridge 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, 308M, 308C, 308Bk Frame memory for each color 309Y, 309M, 309C, 309Bk Data buffer for each color 310 Print control unit 311 Print driver 312Y, 312M, 312C, 312Bk Print head for each color

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

Claims (4)

[Claims] 1. A color ink jet recording method for forming a desired color image on a recording medium by ejecting black ink and a plurality of color inks different from the black ink onto the recording medium. It is determined whether or not a color image exists, and the ejection timing difference between the black ink and the color ink in the adjacent portion between the black image and the color image is set to be longer than the ejection timing difference in the non-adjacent portion between the black image and the color image. A color inkjet recording method characterized by the above. 2. The color ink jet recording method according to claim 1, wherein when the black image and the color image are adjacent to each other, a part or all of the black image is formed with color inks of a plurality of colors. 3. The color ink of the plurality of colors is yellow,
The color ink jet recording method according to claim 1, wherein the color ink jet recording method is magenta or cyan. 4. The black ink and the color ink are ejected by thermal energy.
4. The color inkjet recording method according to any one of 3 to 3.