JPH06152903A - Color ink-jet recording method - Google Patents

Abstract

PURPOSE:To improve ink fixation to prevent bleeding by making a time interval between the ejection of Bk ink and the ejection of plural kinds of color ink to the same position of a recording medium longer than the ejection interval among the color inks. CONSTITUTION:As the process of recording, for instance, a recording head 1 main-scanning is moved and records relatively in the direction of X to the recording medium 106. The numerals N: 1-6 indicate the positions of the recording head 1 to the recording medium 106 at the time of N-th main scanning. In this case, for the recording of the colors of Y(yellow), M(magenta) and C(cyanogen), recording areas overlapping at N-th and (N+1)-th scanning are present between C and M and M and Y but no overlapping recording area is present between Bk and C. The time from a recording operation in a main scanning direction to the next recording operation in the main scanning direction takes longer than the fixing time Td=200msec of Bk ink. Thus, the Bk ink and CMY ink do not bleed on the recording medium.

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. More specifically, it is specifically related to yellow (Y), magenta (M), cyan (C) or green (G). ), Red (R), blue (B), and other color inks, and a black (Bk) ink.

The present invention is applicable to paper, cloth, non-woven fabric, and OHP.
It can be applied to all devices that use a recording medium such as paper, and specific applicable devices include a printer, a copying machine, and a facsimile.

[0003]

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

In general, a color ink jet recording method uses three color inks of cyan, magenta and yellow, and further, four color inks including black are used for color recording.

In the conventional ink jet recording method, it was necessary to use a special paper having an ink absorbing layer in order to obtain a color image of high color development without ink bleeding, but in recent years, due to improvements in ink, printers and copying machines have been developed. A method that has printability on "plain paper" that is used in large quantities in machines and the like has also been put to practical use. However, at present, the printing quality on "plain paper" is still at an insufficient level. The most important factor is compatibility between ink bleeding between colors and black recording quality (particularly black character recording quality).

[0006]

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 rate into the plain paper is used. For this reason, a high-quality image with no ink bleeding between the colors is obtained, but the density is low overall, and around the recorded image area of each color, ink is slightly bleeding along the fibers of the paper, so-called feather. Rings are likely to occur.

Feathering is relatively difficult to notice in a color image area, but is easily noticeable in a black image area, resulting in deterioration of recording quality. In particular, when the black image is a character, it becomes an indistinct character lacking sharpness, resulting in poor quality.

Therefore, in order to obtain a high-quality black record with a small amount of feathering and a high density, it is necessary to use black ink having a relatively slow penetration rate into plain paper. However, in this case, ink bleeding of each color occurs at the adjacent boundary portion between the recording image areas of black and each color,
Remarkably impairs the quality.

As described above, the improvement of color recording quality by the prevention of ink bleeding between black and colors and the reduction of black feathering in particular has been a contradictory issue.

Therefore, Japanese Laid-Open Patent Publication No. 3-146355 proposes a method of not recording an area along the boundary area between black and color. However, this method has a drawback that recorded data changes.

Further, in Japanese Patent Laid-Open No. 4-158049, a multicolor head for color recording and a head for character recording are provided, and the multicolor head and the character recording head are switched based on a recorded image. A method of recording is proposed. However, in this method, in addition to the conventional multi-color head for color recording, a head for character recording is provided, so that cost increase and device enlargement are inevitable.

The present invention has been made to solve the above-mentioned problems of the prior art, and its object is to record an independent black image area which does not come into contact with the color image area. In addition to high density in the area and excellent recording quality with less feathering, in other areas,
An excellent recording quality without ink bleeding between each color of black and color, that is, to achieve both high-quality black recording and high-quality color recording.

Another object is to improve the ink fixability.

[0014]

Therefore, according to the present invention, Bk (black) ink and a plurality of color inks different from the Bk ink are ejected onto a recording medium to form a desired color image on the recording medium. In the color inkjet recording method formed above, the permeation speed of the Bk ink into the recording medium is slower than that of the color inks of the plurality of colors, and the time for ejecting the Bk ink to the same position of the recording medium and the time of ejecting the color inks of the plurality of colors. The interval is Td, which is longer than the ejection time interval between the color inks of the plurality of colors. As a result, it is possible to improve the fixability of the ink.

The color inks of a plurality of colors are yellow, magenta, cyan, or green, red, and blue inks.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described in detail below with reference to the drawings.

(Embodiment 1) FIG. 1 is a perspective view of a recording apparatus for carrying out the ink jet recording method of the present invention.

A carriage 101 is equipped with a recording head 102 and a cartridge guide 103, and guide shafts 104 and 10 are provided.
5 can be scanned.

The recording paper 106 is fed into the main body by a paper feed roller 107, is pinched by a paper feed roller 108 and a pinch roller (not shown), and is sandwiched by a paper holding plate 109 to be fed to the front surface of the paper feed roller 108 for printing. It Two types of ink cartridges, a color ink cartridge 110 containing three colors of yellow, magenta, and cyan, and a black ink cartridge 111 are separately inserted into the cartridge 103 and communicate with the recording head 102.

The yellow, magenta, and cyan inks stored in the color ink cartridge 110 are those that have a high penetration speed into the recording paper so that ink bleeding does not occur at color boundaries when forming a color image. Used. On the other hand, the black ink stored in the black ink cartridge 111 is relatively high in recording paper as compared with the above three types of color inks so that the black image has high density and high quality with less ink bleeding. Those with a slow penetration rate are used.

FIG. 2 shows the recording head 102. Yellow, magenta, cyan, and black ejection port groups are arranged in a straight line on the front surface of the recording head 102. Each group has 24 discharge ports for yellow, magenta, and cyan, and 64 discharge ports for black, and the intervals between colors are equal to or greater than the nozzle pitch.

FIG. 3 is a view of the recording head as viewed from the front of the ejection port. Has 24 nozzles for each of Y, M, and C, and Bk
Has 64 nozzles. Gap between YMC
1G2 is for 8 nozzles, and the gap G3 between C and Bk, which is the bottom of the color nozzles, is for 16 nozzles.

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 for ejecting ink droplets from these ejection ports and electrode wiring for supplying electric power to the electrothermal converter. ing. 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 ejection port, the ink liquid passage, and the common liquid chamber are formed by stacking a partition wall made of a resin, a glass material, a top plate, etc. on the substrate. Further on the rear side, a drive circuit for driving the electrothermal converter based on a recording signal is provided in the form of a printed circuit board.

The silicon substrate and the printed circuit board 202 are the same aluminum plate 203 and the pipe 20 protruding in parallel.
Reference numerals 4 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 path inside thereof.
The flow path communicates with the common liquid chamber.

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

About 40 ng from the yellow, magenta, and cyan discharge ports provided on the recording head 102.
Ink is about 80n from the black discharge port.
g of ink is ejected.

The components of the used ink are as follows. 1. Y (yellow) C.I. I. Direct Yellow 86 3 parts Diethylene glycol 10 parts Isopropyl alcohol 2 parts Urea 5 parts Acetylenol EH (Kawaken Chemical) 1 part Water balance

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

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

4. Bk (black) C.I. I. Direct Black 154 3 parts Diethylene glycol 10 parts Isopropyl alcohol 2 parts Urea 5 parts Water balance

As described above, the CMY ink improves the permeability by adding 1% of acetylenol EH to the Bk ink. In addition to this, other additives include other surfactants, alcohols and the like.

The fixing time of the Bk ink is about 200 ms for ordinary recording paper used in large amounts in copying machines.
In ec, the fixing time of the CMY ink is about 20 msec. Although the fixing time of Bk ink is slower than that of CMY ink, minute ink bleeding is less and recording quality is good.

FIG. 4 is an electrical control block diagram of a recording apparatus for implementing the color ink jet recording method.

Reference numeral 301 denotes a system controller for controlling the entire apparatus, which has a storage element (ROM) in which a control program including a microprocessor is housed,
A memory element (RAM) and the like used when the microprocessor performs processing are arranged. Reference numeral 302 is a driver for driving the recording head in the main scanning direction, and 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 moving 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.
Data is accumulated until it is read from the system controller of. 308 is a frame memory for expanding the data to be printed into image data,
It has enough memory size for printing. In this embodiment, a frame memory capable of storing one print sheet will be described, but the present invention is not limited to the size of the frame memory.

Reference numeral 309 is a storage element for temporarily storing the data to be printed, and the storage capacity changes depending on the number of noises of the recording head. Reference numeral 310 denotes a print controller for appropriately controlling the print head in response to a command from the system controller, and a print control unit for controlling the ejection speed, the number of print data, and the like. 311, 312Y, 312M, 31
A driver for driving the 2C and 312Bk heads, which is controlled by a signal from the print control unit 310.

FIG. 5 is a diagram showing the process of being recorded by the recording method of the first embodiment. The recording head 1 performs recording while moving in the main scanning direction in the direction of arrow X relative to the recording medium 106. N: 123--6 is the Nth
The position of the print head 1 with respect to the print medium 106 at the time of the main scan for the first time is shown. The already recorded area on the recording medium 106 is the range shown in the figure.

Here, in the recording of YMC colors, C and M,
Between M and Y, there are recording areas that overlap in the Nth and (N + 1) th scans, whereas Bk and C, that is, B
There is no overlapping recording area between k and YMC. After the recording operation in the main scanning direction, until the next recording operation in the main scanning direction, the fixing time Td of the Bk ink is Td = 200 msec.
Works to take longer.

As described above, the fixing time Td = 200 m of the Bk ink, which has a relatively poor fixing property as compared with the CMY ink.
Since the CMY ink is recorded after a time longer than sec, the phenomenon that the Bk ink and the CMY ink bleed on the recording medium disappeared. Since the CMY ink has good penetrability and good fixability, bleeding between colors does not occur even if there are overlapping print areas in the Nth and (N + 1) th scans.

This recording operation is performed by using the Bk ink from the ninth and subsequent nozzles in FIG. 3 among the Bk nozzles of the recording head. Since the distance between the C nozzle and the Bk nozzle is 16 nozzles and the first to eighth nozzles are not used, the distance between the C nozzle and the 9th nozzle of Bk is 24.
It corresponds to the nozzle.

That is, it is sufficient to use the Bk nozzle group having an interval wider than the recording width of the CMY ink nozzle group recorded in the main scan immediately after Bk.

The reason why the number of Bk nozzles is larger than that of CMY nozzles is to enable higher speed recording when a recording operation is performed with only Bk colors for a certain main scan. .

The present invention has been described with reference to the embodiments. In the above embodiments, the recording head has been described using a 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. It goes without saying that the present invention can also be applied to a so-called piezo inkjet recording system in which ink is ejected.

(Embodiment 2) In Embodiment 1, an example of the recording head in which the nozzle arrangement is as shown in FIG. 3 was shown, but the present invention is not limited to this.

FIG. 6 shows an example of another nozzle array. (A)
Is a nozzle of each color arranged in a substantially linear Ny (Ny is a positive integer) column in the vertical (Y, sub-scanning) direction and in Nx (Nx is a positive integer) column in the horizontal (X, main scanning) direction. It may be arranged to have a plurality of colors. In (a), Cy is Ny = 8, Bk is Ny = 24, and Nx is a case where Nx = 2 for each color.
Further, (b) shows an example in which YMC is not in a straight line in the X direction.

Further, in FIGS. 7A and 7B, Bk,
The C, M, and Y recording heads may have a separable structure. Alternatively, CMY may be integrated and Bk and CMY may be separable. In other words, the print head may have a nozzle arrangement that can be controlled so that the print areas of Bk and CMY do not overlap each other during the Nth and N + 1th main scans.

(Embodiment 3) Furthermore, CMY is integrated into B
k and CMY are separable from each other, and may have a recording head having nozzles for Bk recording and a recording head having nozzles for CMY recording.

FIG. 7 shows a recording head 1: 3 for CMY recording.
31 and the recording head 2: 331 for Bk recording are moved in the main scanning directions opposite to each other. The drive source of the recording head in the main scanning direction is a carriage motor 304.
Done in. The two recording heads are Pry 321 and Pley 32
When the motor rotates in the A direction, the timing belt 320 is moved through the pulley 321 so that the CMY recording head 331 moves to the right side as indicated by arrow C, and Bk The recording head 332 moves to the left as indicated by arrow D. Recording may be performed at the same time or may be performed by alternating scanning. The recording directions will be reversed if they are performed at the same time, but they will be the same if they are performed alternately.

The recording medium 106 has an arrow E in the sub-scanning direction.
Move in the direction of. The Bk nozzle group and the C nozzle group of the color ink to be recorded subsequently are separated by a gap G3. The gap G3 is wider than the width of the recording area of the C nozzle group.

Further, as shown in FIG. 11, two recording heads can be independently moved by using, for example, two carriage motors and two timing belts.
The recording head may record Bk, and the CMY recording head may record CMY later.

(Embodiment 4) In this embodiment, the following new method is added to the above-described embodiments. As a result, the color mixture of Bk and CMY on the recording medium is further reduced, and higher quality recording can be obtained.

The new method is an ink having a characteristic that the permeation speed of Bk into the recording medium is slower than that of CMY, and according to the recording data, at the time of recording Bk, case1: Bk ink is ejected for recording, case2: It is a method of recording by switching to ejecting and recording ink other than Bk ink.

Whether or not there is a color (C and / or M and / or Y) image area within N (N is 1, 2, 3, 4) pixels adjacent to the black image area of the recording data. And the case 1 and the case 1 according to the determined result.
Switch to se2, in the former case1 in case 1,
In the latter case, the recording is made in case 2.

As an example thereof, in the case of printing at a higher speed, it is determined whether or not there is a color image area adjacent to the black image area of the print data in the black image area.
Only the character code data portion is formed, and the black image area such as pit image data is formed by the color inks of the plurality of colors.

Further, it is determined whether or not there is a color image area adjacent to the black image area of the print data, depending on the case of printing at a higher speed or the condition of the memory of the printing apparatus that realizes the printing method. This is only when the black image area of the black image area is not out of the range where the line memory of the recording apparatus or the effective use is made, and the other black image areas are formed by the color inks of the plurality of colors. , And.

FIG. 8 is a flow chart showing the operation of this embodiment.

In STEP 1, the host computer 30
6, the data is transferred, and the system controller 301 reads the data stored in the reception buffer 307. In STEP 2, it is determined whether the read print data includes black data or only data other than black. When black is included, the process proceeds to STEP 7, and in other cases, the process proceeds to STEP 10.

At STEP 7, attention is paid to the black data, and it is determined whether or not the color recording data is present in the pixel adjacent to the periphery of the black image recording area. Here, the “adjacent position” is a position “up and / or down and / or left and / or right” with respect to each pixel forming a black image area on the recording medium, and forms a color image area at this position. It is determined whether or not there is at least one color recording pixel to be processed. The pixel pitch P is about 70.56 μm, and the recording density is 360 dpi. If there is a color pixel adjacent to the black recording pixel, the process proceeds to STEP8, and if not, the process proceeds to STEP9.

In STEP 8, the black recording pixels are expanded in the C, M and Y data buffers for color recording. ST
In EP9, black recording pixels are expanded in the Bk data buffer for black recording. In STEP 10, each color data is developed in each color data buffer. STEP11
Then, the data is read from the reception buffer, and it is determined whether there is data to be printed and whether 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 12. In other cases, the process returns to STEP1. In STEP 12, the recording head 1
The recording operation is performed at 02.

FIG. 10 is an example showing an image in which a black image and a color image are mixed. The image portion A is composed of black characters of X, Y, Z and underlines, and is bit image data. The image portion B is code data of black characters.
The image portion C is an image having a black graph on the yellow background portion and is pit image data. The image portion D is an image having black character code data on the cyan background portion. The image portion E shows a case where a magenta image is present in a part of the background of the black pit image data.

According to the method of this embodiment, the image area A is only black and has no background color, that is, the color recording area is not in contact with the black recording area, so that black ink is ejected (ejected). ) Is recorded by the black ink recording head.
The image portion B is the same as the image portion A and is recorded by the black ink recording head. Since the image portion C and the image portion D are images of other colors around the black image, the black portion is recorded with color ink, that is, three color inks of Y, M, and C. Image part E
Of the bit image data of black, the number "1" is recorded by the black recording head because the color image is not adjacent to the number "1". On the other hand, the number "3" is printed by the color ink recording head because the surroundings are all adjacent to the magenta image. The numeral "2" is printed by the color ink recording head because a part of its periphery is adjacent to the magenta image.

As described above, when the black image recording area is independent and no other color is recorded on the periphery, Bk ink having high recording density and less feathering is used for recording, and the black image recording area is independent. If not, that is, if at least a part of the black image recording area and the image area of another color are in contact with or overlap with each other, the black image recording area is recorded with C ink, M ink, and Y ink. Records high-quality color images that prevent bleeding between black and other colors.

Further, the method for determining whether or not the color recording data is present in the pixel adjacent to the periphery of the black image recording area is processed by software here, but the method is not limited to this. , May be replaced with hardware for processing.

Here, in STEP 7 of FIG. 8, the position adjacent to the periphery of the black image recording area means “upper and / or lower and / or left and right” for each pixel forming the black image area on the recording medium. Or the right ”position. This is an example targeting P or less with respect to the pitch P of recording pixels, and it is necessary to widen this range depending on the ink used and the recording medium.

An experiment was carried out in which the ink of Example 1 was used to record on various types of plain paper. Assuming that the pitch P of the recording pixels is X-P around the black image recording area, first, X =
√2, that is, the position of “top and / or bottom and / or left and / or right, and / or top right and / or top left and / or bottom right and / or top left” of the black pixel of interest is considered. Next, up to X = 2 was considered. Similarly, X = 2
√2. In this way, the effect of the present invention was satisfactorily exhibited on most types of plain paper by performing the processing in consideration of X = 4√2.

From the above, the position adjacent to the periphery of the black image recording area of interest is defined as P for the minimum pixel pitch of recording for each pixel forming the black image area on the recording medium.
A case where at least one color recording pixel forming a color image area exists at a recording position within XP.
It is effective when 4√2 ≧ X ≧ 1.

Up to now, it has been determined whether or not another color is recorded around the entire black image recording area. However, the calculation for this determination is a recording aiming at a faster recording process. The method requires a relatively long time and is therefore heavily loaded. Therefore, as shown in FIG. 5, by performing similar processing only on the character code in the black image recording area, the calculation processing can be speeded up.

In FIG. 9, STEP3 is added as compared with FIG. In this STEP 3, if the black image recording area of interest is the character code, the subsequent processing is performed as shown in FIG.
However, in the case of image data other than the character code, such as bit image data, the process proceeds to STEP8, and black recording pixels are expanded in the C, M, and Y data buffers for color recording.

Even with such processing, there is an advantage that at least the quality of black characters can be made higher.

Further, although the frame buffer for recording one page has been shown so far, the present invention can be applied even when a line buffer is provided instead of the frame buffer.

This is done in STEP 7 of FIG. 8 as "positions adjacent to the periphery of the black image recording area" for each pixel forming the black image area on the recording medium, "upper and / or lower and / or left and / or However, in addition to this, the problem is solved by assuming that the black image recording area is not adjacent to other colors at least in the effective recording area of the line buffer. To do.

(Fifth Embodiment) In the first embodiment, color recording using Bk ink and CMY ink is performed in one sub-scan, but it may be performed in two sub-scans.
This is done by first recording one recording medium with Bk ink,
Next, CMY may be recorded after Bk is completely fixed.

This method is particularly effective when recording at a higher speed, and particularly when recording on a recording medium with a slower fixing. That is, if high-speed recording that does not fix Bk is possible in the main scan of Bk recording once or several times, or if recording is performed on a recording medium having a relatively long fixing time. Is the fixing time Td of the Bk ink.
The CMY may be recorded in a shorter time. At this time, the problem can be solved by ending the recording of one recording medium with the Bk ink and then recording the CMY after the time when the Bk is completely fixed. As this means, a well-known repetitive recording mechanism which is often used in the thermal transfer recording system in the recording device performs sub-scanning at least twice and corresponding main scanning of Bk and CMY.
This may be four times Bk, C, M and Y. When using a recording apparatus configured to record either the Bk ink recording head or the CMY recording head at a time,
The user first records Bk, resets the recording medium again, and records CMY. Also, this is Bk
Alternatively, when using a recording apparatus configured to record only one color of C, M or Y at one time, Bk, C, M and Y may be performed four times. Etc.

In the above-described embodiment, plain paper, which is used in large quantities in copying machines and the like, is used as a recording medium.
However, the present invention is not limited to this. For example, a transparency sheet used for an overhead projector, a cloth, or a paper or film having a special coat layer is used. , Etc. may be used.

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

Regarding the typical structure and principle thereof, see, for example, US Pat. Nos. 4,723,129 and 4740.
What is done using the basic principles disclosed in 796 is preferred. This method is a so-called on-demand type,
It can be applied to any of the continuous type, but especially in the case of the on-demand type, it can be applied to the sheet holding the liquid (ink) or the electrothermal converter arranged corresponding to the liquid path. By applying at least one drive signal that gives a rapid temperature rise exceeding nucleate boiling corresponding to the recorded information, 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. It is more preferable to make this drive signal into a pulse shape, because the bubble growth and contraction are immediately and appropriately performed, so that the ejection of the liquid (ink) with excellent responsiveness can be achieved. As the pulse-shaped drive signal, U.S. Pat. Nos. 4,463,359 and 4,345 are used.
Those as described in the '262 patent are suitable. If the conditions described in US Pat. No. 4,313,124 of the invention relating to the rate of temperature rise on the heat acting surface are adopted, more excellent recording can be performed.

As the constitution of the recording head, in addition to the combination constitution of the ejection port, the liquid passage, and the electrothermal converter (the linear liquid passage or the right-angled liquid passage) as disclosed in the above-mentioned respective specifications. US Pat. No. 4,558,333, US Pat. No. 4,558,333, which discloses a configuration in which a heat acting portion is arranged in a bending region.
A configuration using the specification of No. 459600 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 structure based on Japanese Patent Laid-Open No. 138461/1984, which discloses a structure in which the discharge section is associated with the discharge section.

[0078]

As described above, according to the present invention, B
After recording k ink, Bk ink is fixed, then CMY
Since the recording is performed, ink bleeding is reduced even on a Bk and color (CMY) recording medium, and a high quality recorded image can be obtained.

When recording an independent black image area which does not come into contact with the color image area, the density of the black image area is high and the recording quality is excellent with less feathering. , Excellent recording quality without ink bleeding between black and color, that is, high-quality black recording and high-quality color recording are compatible.

[Brief description of drawings]

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

FIG. 2 is a head mechanism diagram of an inkjet recording apparatus to which the present invention can be applied.

FIG. 3 is a front view of a recording head.

FIG. 4 is a block diagram of an inkjet recording apparatus control circuit to which the present invention can be applied.

FIG. 5 is a diagram showing a recording process of Example 1.

FIG. 6 is a front view of a recording head according to a second exemplary embodiment.

FIG. 7 is a diagram showing an arrangement of recording heads and a recording movement according to a third embodiment.

FIG. 8 is a flowchart illustrating the operation of the fourth embodiment.

FIG. 9 is a flowchart illustrating another operation of the fourth embodiment.

FIG. 10 is an example of an image for explaining the present invention.

FIG. 11 is a diagram showing another arrangement of the recording head and the recording movement according to the third embodiment.

[Explanation of symbols]

101 carriage 102 recording head 103 cartridge 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 of each color Frame memory 309Y, 309M, 309C, 309Bk Data buffer for each color 310 Print control unit 311 Print driver 312Y, 312M, 312C, 312Bk Recording head for each color

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

Claims (9)

[Claims] 1. A color inkjet recording method for forming a desired color image on a recording medium by ejecting a Bk (black) ink and a plurality of color inks different from the Bk ink onto the recording medium. The permeation speed of the Bk ink is slower than that of the color inks of the plurality of colors, and the time interval between the ejection of the Bk ink to the same position on the recording medium and the ejection of the color inks of the plurality of colors is the ejection time between the color inks of the plurality of colors. A color inkjet recording method, wherein Td is longer than the interval. 2. The color inkjet recording method according to claim 1, wherein first, the Bk ink is ejected, and after the Td time for fixing the Bk ink has elapsed, the color inks of the plurality of colors are ejected. 3. A Bk ink recording head and a plurality of color ink recording heads are separated from each other, and are operated in opposite directions with respect to the main scanning direction by a power transmission system using the same drive source. The color ink jet recording method according to claim 1, wherein 4. The color ink jet recording method according to claim 3, wherein formation of a black image is switched between Bk ink and the color inks of a plurality of colors. 5. N (N is 1, 2,
3, 4) It is determined whether or not there is a color image area within pixels, and it is determined whether to form the black image with the Bk ink or the multiple color inks according to the determination result. The color ink jet recording method according to claim 4, wherein 6. Only the character code data portion in the black image area determines whether or not there is a color image area adjacent to the black image area, and the black image area such as pit image data is determined. The color ink jet recording method according to claim 4, wherein the color inks are formed with the color inks of a plurality of colors. 7. The determination as to whether or not there is a color image area adjacent to the black image area is performed only when the inside of the black image area is within the range stored in the memory. The color ink jet recording method according to claim 4, wherein the other black image area is formed by the color inks of the plurality of colors. 8. The color ink jet recording method according to claim 1, wherein the plurality of color inks are yellow, magenta, cyan, or green, red, and blue inks. 9. The color ink jet recording method according to claim 1, wherein the ink is ejected by thermal energy.