JP3005165B2 - Recording data processing method, inkjet recording apparatus and method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording data processing method and an ink jet recording apparatus for recording with two or more different kinds of inks, for example, a penetrating ink used for a color ink and an evaporating ink used for a black ink. More particularly, the present invention relates to a print data processing method, an ink jet printing apparatus, and a method for improving the image quality of a boundary portion between different kinds of ink.

[0002]

2. Description of the Related Art In recent years, OA devices such as personal computers and word processors have become widespread. As a method of printing out information input by these devices, for example, a wire dot method,
Various recording methods such as a thermal transfer method and an ink jet method have been developed. With the recent spread of desktop publishing (DTP), the need for color printing apparatuses has been rapidly increasing, and ink-jet printing methods capable of inexpensive and high-quality color output have attracted attention.

One of the typical factors controlling the image level of the above-mentioned ink jet recording apparatus is a recording ink. The recording ink is generally a water-based liquid, and the water-based recording ink can be roughly classified into two types, a permeation system and an evaporation system, based on a fixing mechanism on a recording medium.

[0004] Since the penetrating ink has a large wetting property to the recording medium, the recording ink permeates deep into the recording medium, so that the fixing is completed at an extremely high speed. As described above, if the permeating systems are close to each other, it is possible to prevent the color mixture and the flow of the ink on the recording medium surface. However, since the recording ink penetrates deep into the recording medium, the coloring property is poor, and it is difficult to obtain a contrast with the recording medium. Therefore, it is preferable to use it only for inks such as Y (yellow), M (magenta), and C (cyan).

Bk inks used as contour enhancement and characters are required to have sharp edges, so it is preferable to use evaporative inks that trap dyes on the surface. However, if both the evaporating ink and the penetrating ink are used, color mixing occurs in the boundary contact region regardless of which is ejected first.

In view of the above, there are provided means for detecting a border where black and color, which are different kinds of ink, are close to each other, and means for replacing a boundary portion pixel which replaces a recording pixel in a place where the different kind of ink is close with at least one other kind of ink pixel. An ink jet recording apparatus having such a configuration has been proposed. Specifically, by replacing the boundary portion (for example, 4 dot width) of the black print dot with the color print dot by a predetermined process black (PCBk) formed of yellow, magenta, cyan, and black, the boundary contact is made. Color mixing in the area is prevented.

[0007]

However, in the above recording method, when a black character (ABCDE) is recorded on the back of a color gradation as shown in FIG. 12, a boundary area between all black characters and the color is recorded. (Here, 4 dot width) is subjected to PCBk conversion. That is, regardless of the print duty of a color adjacent to a character printed in black, the entirety of the 4-dot width of the boundary detection area of the black character is subjected to PCBk conversion. Certainly, the PC mentioned above
With the Bk conversion method, it is possible to prevent color mixing at the boundary part, no matter how high the color back is.

However, in the actual printing as shown in FIG. 12, there is a problem that the lower part of the character, which is a color back with a low duty, is printed more blurry in the PCBk printing of the boundary part than the actual black character. Occurs. This is because the contrast between the recording medium and the black characters can be more clearly recognized by the human eye as the color duty is lower in the duty ratio.

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above-mentioned problems, and an ink jet recording apparatus and method capable of solving image deterioration caused by bringing different kinds of inks close to each other and enabling high-quality image recording. The purpose is to provide.

Further, the present invention can provide an ink jet recording apparatus and method capable of obtaining a sharp black image with little color mixture regardless of the proximity of different kinds of inks, for example, black ink and color ink.

[0011]

In order to achieve the above object, the present invention provides an ink jet recording apparatus for recording an image by forming recording dots by discharging different kinds of ink from a recording head to a recording medium. The boundary contact degree between the recording dot to be formed and the target dot is determined by setting a weighting factor for each pixel in an n × m pixel area (n ≧ 1, m ≧ 1) with the target dot as the center. Boundary contact degree detecting means for detecting the recording dots of the different kinds of ink present in the area by correcting with the weight coefficient and counting, and according to the boundary contact degree detected by the boundary contact degree detecting means, And a replacing means for replacing the recording pixels formed by the above with recording dots made of different kinds of ink.

According to the present invention, there is provided an ink jet recording method for recording an image by forming recording dots by ejecting different kinds of ink from a recording head to a recording medium. The degree of contact is defined as an n × m pixel area (n ≧
A weight coefficient is set for each pixel of (1, m ≧ 1), and the recording dots of the different kinds of ink existing in the pixel area are detected by correcting with the weight coefficient and counting. In accordance with the detected degree of boundary contact, a step of replacing print data of a print pixel formed by the noted dot with data corresponding to a print dot of a different kind of ink, and based on the print data replaced by the replacement step, Ejecting ink.

Further, the present invention relates to a recording data processing method for ejecting different kinds of ink from a recording head to a recording medium to form recording dots and record an image. The degree of boundary contact with the pixel area (n × n)
.Gtoreq.1, m.gtoreq.1), a weighting factor is set for each pixel, and the recording dots of different types of ink existing in the pixel area are detected by correcting with the weighting factor and counting. And replacing the print data of the print pixels formed by the target dots with data corresponding to print dots of different kinds of ink in accordance with the degree of boundary contact detected by the method.

[0014]

According to the above configuration, since the recording pixels are replaced with other types of ink pixels in accordance with the proximity status of different types of ink, it is possible to perform high-quality recording while making different types of inks close to each other.

[0015]

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

(Recording Apparatus) FIG. 8 is a schematic perspective view showing the structure of an embodiment of the ink jet recording apparatus of the present invention. As shown in FIG. 8, the carriage 2 is
Is transmitted to the lead screw 5 via the two driving force transmission gears 9 and 10, so that the carriage 2 is reciprocated in the directions indicated by arrows a and b. The carriage 2 has an ink jet cartridge 1 in which an ink tank (not shown) for storing recording ink and a recording head (not shown) for discharging ink toward the recording paper 30 are mounted. Cartridge 1
A platen 4 for transporting the recording paper 30 is rotatably provided to face the recording paper 30. The recording paper 30 conveyed by the platen 4 is pressed against the platen 4 by the paper pressing plate 3 on the side facing the ink jet cartridge 1 and is held so that the distance between the recording paper 30 and the ink jet cartridge 1 becomes a predetermined distance. And the drive motor 1
The recording operation of ejecting ink from the recording head while moving the carriage 2 by 1 is performed based on the control of the recording control unit 22.

On the left side of the drawing in the moving direction of the carriage 2,
Two photocouplers 7 and 8 are provided. Each of the photocouplers 7 and 8 is a home position detecting unit for confirming the presence of the lever 6 provided at the left end of the carriage 2 in the illustrated area and switching the rotation direction of the drive motor 11 and the like. .

A cap member 13 supported by a cap support member 14 is provided at a position where the ink jet cartridge 1 is moved during the suction operation, outside the range of the reciprocating operation in the recording operation of the ink jet cartridge 1. The cap member 13 is for capping the front surface (discharge port surface) of the recording head of the ink-jet cartridge 1.
By performing suction inside, a head recovery operation such as removal of thickened ink and bubbles in the recording head is performed. A cleaning blade 15 supported by a blade support member 16 is provided on a side of the cap member 13. The cleaning blade 15 is supported by the blade support member 16 so as to protrude toward the ink jet cartridge 1,
Contact with the front surface of the recording head is possible. Thus, after the suction operation, the cleaning blade 15 is made to protrude into the movement path of the ink jet cartridge 1 to wipe off dirt and the like on the front surface of the recording head as the ink jet cartridge 1 moves. The cleaning blade 15 is not limited to this mode, and a known cleaning blade can be applied.

(Printing Head) Here, the above-described printing head will be described with reference to FIG. FIG. 9 is a perspective view of a main part of the recording head of the ink jet cartridge shown in FIG. The recording head has a surface facing the recording paper 30 (see FIG. 8) at a predetermined interval as shown in FIG.
Y (yellow), M (magenta), C (cyan), Bk
(Black), the discharge ports 1bY, 1
A plurality of bM, 1bC, and 1bK are formed at a predetermined pitch. An electrothermal converter 1e for generating energy for ink discharge is provided along the wall surface of each liquid path 1d connecting the common liquid chamber 1c and each discharge port 1b. The common liquid chamber 1c is provided with the above-described ink jet cartridge 1
(See FIG. 8), and the common liquid chamber 1c is supplied with ink from the ink tank. The ink supplied from the ink tank to the common liquid chamber 1c and temporarily stored therein is transferred to the liquid path 1d by capillary action.
Into the liquid passage 1d to form a meniscus at the discharge port 1b.
Keep the condition satisfied. At this time, when the electrothermal transducer 1e is energized through an electrode (not shown) and generates heat, the ink on the electrothermal transducer 1e is rapidly heated, and bubbles are generated in the liquid passage 1d. The ink is ejected from the ejection port 1b by the expansion.

(Control Configuration) Next, a control configuration for executing recording control of each section of the apparatus configuration will be described with reference to a block diagram shown in FIG. In FIG. 1 showing a control circuit, reference numeral 10 denotes an interface for inputting a recording signal;
11 is an MPU, 12 is a program ROM for storing a control program to be executed by the MPU 11, and 13 is a dynamic RAM for storing various data (such as the recording signal and recording data supplied to the head). The number, the number of replacements of the ink recording head, and the like can be stored.
Reference numeral 14 denotes a gate array that controls supply of print data to the print head.
1. It also controls the transfer of data between the RAMs 13. Reference numeral 20 denotes a carrier motor for transporting the recording head, and 19 a transport motor for transporting the recording paper. 15 is a head driver for driving the head, and 16 and 17 are the transport motors 1
9. A motor driver for driving the carrier motor 20.

FIG. 11 is a circuit diagram showing the details of each part in FIG. The gate array 14 includes a data latch 141,
It has a segment (SEG) shift register 142, a multiplexer (MPX) 143, a common (COM) timing generation circuit 144, and a decoder 145. The recording head 18 has a diode matrix configuration, and a drive current flows through the ejection heaters (H1 to H128) where the common signal COM and the segment signal SEG match, thereby heating and ejecting the ink.

The decoder 145 decodes the timing generated by the common timing generation circuit 144 and selects one of the common signals COM1 to COM8. The data latch 141 latches the recording data read from the RAM 13 in 8-bit units, and the multiplexer 143 stores the recording data in the segment shift register 1.
In accordance with 42, it is output as segment signals SEG1-8. The output from the multiplexer 143 can be variously changed depending on the contents of the shift register 142, such as 1 bit unit, 2 bit unit, or all 8 bits.

The operation of the above-described control structure will be described. When a recording signal enters the interface 10, the recording signal is converted between the gate array 14 and the MPU 11 into recording data for printing. Then, the motor drivers 16 and 17 are driven, and the recording head is driven according to the recording data sent to the head driver 15 to perform printing.

(Embodiment 1) In this embodiment, when color printing is performed by using the above-described printing apparatus, different colors of ink are not mixed with each other at a boundary where different colors are close to each other, and a more true black color is obtained. It is an object of the present invention to provide an ink jet recording apparatus capable of performing recording such that a near edge becomes sharp.

In this embodiment, Y, M,
Four types of inks of C and Bk are used. As for the composition of each ink, the Bk ink is composed of a dye, a solvent containing a nonvolatile component and containing water as a main component, and has a surface tension of about 50%.
dyn / cm ink is used. On the other hand, Y, M, C
The ink is adjusted to an ink having a surface tension of about 27 dyn / cm by increasing the wettability by adding acetylenol to a solvent containing a dye, a nonvolatile component and water as a main component.

The critical surface tension of general recording paper is about 35 dyn / cm. The Bk ink is an ink that is hard to spill on paper, and the fixing time is longer. However, since the dye moves (fixes) only to a depth range of about 20 μm from the surface layer of the recording paper, it exhibits relatively high density and high color development, has high contrast with the recording paper, and emphasizes high quality. It is an ink composition.

On the other hand, the C, M, and Y inks are inks having a low surface tension as described above, have a property of being easily wetted on recording paper, and are fixed at a very high speed on recording paper.
However, since the ink penetrates deep into the recording paper, the color developability is slightly inferior. However, as described above, the so-called color ink (Y, M, C ink) has a contrast with the recording paper that is smaller than that of the Bk ink. Even if not strong, there are few practical problems. Therefore, as described above, the ink composition is configured such that no border bleeding occurs.

In the above-described boundary processing, when black characters of a color gradation back are recorded, all the boundary areas are similarly subjected to PCBk conversion. In particular, low-duty color-backed black characters are originally PCBk
Even without conversion, the probability of mixing of color and black is very low, and PCBk conversion has disadvantages in terms of loss of edge sharpness and deviation from original black.

Hereinafter, the means employed in the present embodiment to solve the above-mentioned problems will be described in detail.

FIG. 1 is a control block diagram for explaining one embodiment of the present invention. The control configuration according to the present exemplary embodiment includes a boundary contact degree detecting unit 1000 that detects a proximity state (hereinafter, referred to as a contact degree) at a boundary section between different kinds of ink, and a dot that replaces a dot with a different kind of ink according to the contact degree at the boundary section. It has a replacement unit 1001, an arithmetic processing unit 1002, a print buffer 1004 for storing data from the host, and a work buffer 1003 for temporarily storing the result of the arithmetic processing.

FIG. 2 is a flowchart illustrating the first embodiment of the present invention.

(Calculation of Boundary Contact Degree) In the recording apparatus, the recording data for each color is developed into bit drawing data of 1 or 0 indicating whether or not to form dots prior to recording. Print buffer).

First, when there is a print start command, Y, M, C
Logical OR (OR) of the data in each print buffer
And store it in the color data work buffer (S1
00, S101). Bk is independently stored in the black work buffer (S102).

Subsequently, a boundary contact coefficient previously set for a 9 × 9 area in proportion to the distance from the target dot of Bk is added with the Bk target dot as the center to obtain a boundary contact degree (S103). ). The added value is detected to determine which rank among a plurality of preset ranks (here, four ranks, which is preferably optimized according to the configuration of the printing apparatus or the characteristics of the ink), and attention is paid to Bk. The dots are stored in buffers 1 to 4 for storing the degree of boundary contact of any of the corresponding ranks (S104). The above processing is performed for all Bk dots (S105). As a result, all the Bk dots are stored in any of the boundary contact degree storage buffers 1 to 4.

FIG. 3 shows n × m centered on the dot of interest.
(In this embodiment, it is set to 9 × 9, but it is preferable to set the value in accordance with the configuration of the recording apparatus and the characteristics of the ink.) The boundary contact coefficient of the pixel area is shown. The relationship between the added value of the boundary contact coefficient of the target dot and the rank is shown below.

Rank Boundary contact degree RANK1: 0.000 to 0.779 RANK2: 0.800 to 1.558 RANK3: 1.559 to 2.337 RANK4: 2.338 to 3.116

Here, the vertical and horizontal dot size (bitmap size) serving as an area to be processed at one time is the number of dots to be detected for detecting the degree of boundary contact (in the present embodiment, the number of dots is 9 × There is no limitation as long as the size is 9 pixels or more, but it is often easy to set the horizontal size to one line of the recording size and the vertical size to the head nozzle.

Further, the logical sum or the logical product may be performed by utilizing the function of the CPU or by a method of processing with a hard logic. In addition, processing may be performed in bit units, byte units, or word units, but needless to say, processing in large units enables high-speed processing.

(Replacement of Boundary Pixel) In theory, a black pixel can be created by superimposing Y, M and C inks (a black pixel created by mixing Y, M and C inks is described below). PCBk). Y, M, C
Since the ink is a penetrating ink as described above, the PCBk created with the penetrating ink does not mix with the Y, M, and C pixels. If all colors, including black, are created with Y, M, and C inks, the problem of bleeding at the boundary between different types of inks can be solved. However, in reality, black images of PCBk created with Y, M, and C inks , It is difficult for the so-called black that the user wants. This is not a problem that applies only to the ink used in an ink jet recording apparatus, and it can be understood from the fact that black is mostly a black-only ink in the field of printing such as gravure.

As described above, since black is desired to be black with high contrast, a penetrating ink in which a dye is buried deep in a recording medium is not suitable, and an evaporating ink is used. For this reason, a bleeding problem occurs at the boundary of the boundary.

Therefore, in the present invention, the frequency of contact between the color and black and the boundary portion is detected, and if the color duty is high, printing is performed using PCBk as much as possible. If the color duty is low, True Black (single black ink) is used. By performing the recording in step (1), it is possible to obtain a higher quality black image.

After detecting the degree of contact at the boundary between the color pixel and the Bk pixel by the boundary contact degree detecting means at the boundary, the Bk data at the boundary is converted into PCBk data corresponding to the duty of the adjacent color. The replacement can improve the image quality of the Bk image as a whole and solve the problem of image disorder at the boundary between different kinds of ink.

FIG. 4 shows PCBk conversion masks 1 to 4 corresponding to the rank-ordered boundary contact degrees. In this embodiment, for simplicity, PCBk is composed of Bk ink and CYAN ink, and the ratio is 100: 0, 75:25, 62.5:
37.5, 50:50. Of course, PC
Masks for Y and M may be added in accordance with the color of Bk, and a large number of the ratios may be used.

Boundary contact degree storage buffers 1-4 and PCBk conversion masks 1-4 (CYA) corresponding to their ranks
N, Bk) and an AND (S106).
Subsequently, the logical sum (OR) of the logical product value of each rank of the color (here, CYAN) is calculated (S107). As a result, ink for recording a black image (ink of the replacement target pixel) is obtained for each pixel.

The result of the logical sum (OR) is added to the original data of the print buffer for each color (here, CYAN) (S10).
7). Unnecessary black pixels can be deleted by replacing Bk with the original data in the print buffer (S108).

Since all the replacement target pixels are Bk pixels, the Bk pixel which is the replacement target pixel is deleted from the Bk original pixel, and at the same time, the Y, M, and C pixels corresponding to the deleted Bk pixel are added. That is, Y, M,
By performing a logical OR of the original print buffer, which is the original image of C, and the additional pixel, the additional processing of the pixel can be realized.

As described above, the problem of border bleeding can be solved by performing pixel addition reduction correction on the data of the print buffer, which is the original image formed for each of the colors Y, M, C, and Bk.

FIG. 5 shows a recorded image when this embodiment is applied. As shown in FIG. 5, in a region where the color density (duty) is low, black pixels are not replaced, and a black image is formed with black ink. Therefore, a sharp black image can be recorded. Color mixture with a color image is unlikely to occur in the first place because the density (duty) of the color image is low. On the other hand, in areas where the color density is high,
Since the replacement of the black pixel is performed, the color mixture with the color image does not bleed.

As described above, in this embodiment, sharp black character qualities can be recorded without color mixing by performing the optimum boundary processing according to the gradation, and high quality recording can be realized.

(Embodiment 2) In this embodiment, a color pixel adjacent to a Bk pixel at a boundary portion is a secondary color (Red, Green).
n, Blue), and more accurately Bk
This is to detect the degree of boundary contact between a pixel and a color pixel.

Generally, in a printing apparatus for printing binary data, one or two of yellow, magenta, and cyan inks are ejected per pixel of a color image.
An image is represented by two different color inks (red, green, and blue are obtained as a result of mixing colors). For this reason, even at the boundary with the same color image, yellow,
A black image adjacent to red, green, and blue is easier to mix colors than an image adjacent to magenta and cyan.

Therefore, in this embodiment, the color (Y, M,
C) The boundary contact degrees Y, M, and C for each color print buffer data are determined from the boundary contact coefficient, and finally, all the boundary contact degrees Y, M, and C for each color are added. Thus, the boundary contact degree of the black dot of interest is obtained.

FIG. 6 shows a flowchart for explaining the present embodiment.

First, when there is a print start command, Y, M, C
Are stored in the color data work buffers Y, M, and C, respectively (S200, S200).
201). Bk is stored in the black work buffer (S202).

Subsequently, for each 9 × 9 area in proportion to the distance of the Bk from the target dot, a boundary contact coefficient separately set for each color (Y, M, C) is added centering on the target dot of Bk. Thus, the boundary contact degree for each of Y, M, and C is obtained (S203). All the boundary contact degrees calculated separately for each color with respect to the same target dot are added to obtain the boundary contact degree of the target dot (S204).

It is detected which rank of the added value corresponds to one of a plurality of preset ranks (here, four ranks, preferably optimized according to the configuration of the printing apparatus or the characteristics of the ink). The data is stored in the rank boundary contact degree storage buffers 1 to 4 (S205). When the processing for one line is completed, the dot replacement processing of the boundary portion is subsequently performed (S206 to S209). The process of dot replacement at the boundary is the same as S105 to S108 in the first embodiment, and a description thereof will be omitted.

Here, the boundary contact coefficient of the region of 9 × 9 pixels centered on the dot of interest is the same as in the first embodiment.

In this embodiment, the relationship between the boundary contact degree of the target dot and the rank is set to be twice the value of the boundary contact degree in the first embodiment in order to add the values calculated separately for each color as described below.

Rank Boundary contact degree RANK1: 0.000 to 1.558 RANK2: 1.559 to 3.116 RANK3: 3.117 to 4.677 RANK4: 4.675 to 6.232

As described above, the color pixel formed by two dots is more easily mixed with Bk than the color pixel formed by one dot. Further, it is possible to accurately predict the occurrence of color mixture at the boundary between the Bk pixel and the color pixel, and it is possible to perform an optimal dot replacement process at the boundary.

(Embodiment 3) Next, an embodiment in which the boundary contact degree detecting means and the dot replacing means are processed at high speed will be described.

Although it is of course possible to perform boundary detection and replacement of recording pixels by software using the algorithm as described above, it is extremely burdensome to perform all of the processing in software. An outline of the weight of the processing will be considered, taking the case of processing one row of data as an example.

The recording heads used in this embodiment are Y, M,
Four heads C and Bk, 64 nozzles each, the resolution is 360 DPI, and the recording paper size is the A4 size as described above. At this time, the print buffer size of one line is 64 vertical.
A dot (8 bytes) is 2880 dots wide. When all the processes are performed by accessing this buffer in byte units, only the process of calculating the logical sum of the Y, M, and C pixels is performed.
Load RAM at least 69120 times (8 × 288
0 × 3) and 23040 times of write processing to the RAM are required. Also, even after the data of the degree of boundary contact is obtained,
To obtain the logical product of the mask pattern for each color and the logical sum of the logical product for each color and the original image for each color, at least 200,000 RAM reads and 90,000 times R
A write operation to AM is required. However, the processing being executed is a simple loop operation, and is not processing in which the output result is fed back to change the next processing content. Therefore, it can be said that the processing content is extremely easy to harden.

FIG. 7 is a diagram showing a control configuration in which the above processing is hardened. The outline of the hardware processing will be described with reference to the drawing. To the logic 2004, the head addresses of the print buffers 2000 to 2003 for the Y, M, C, and Bk images are input. Data of each color is stored regularly from the head address. In the present embodiment, recording pixel data is stored at continuous addresses. The logic 2004 that has received the head address for each color reads out the data of the head address (in this embodiment, in units of bytes) and stores it in a memory in the logic.

When this processing is completed, the logic 2004
In the logic, the head address for each color is incremented by one byte in the logic, the next address to be read is automatically generated, and desired data is read. The rule of the data reading order does not matter, and the logic 2004 is capable of reading desired data at a desired time without a CPU instruction (DMA processing is possible).

As described above, the CPU 2006 merely sets the start address of the print buffer of the original image of Y, M, C, and Bk in the logic 2004, and
Automatically reads the original image, calculates the logical sum of each color (Y, M, C), calculates the boundary contact degree of the Bk data with the logical sum data, and ranks the data. Control processing for outputting Bk data ranked according to the rules becomes possible. The output Bk data is stored in a work buffer (not shown).

In order to perform the above-described processing by software, it was necessary for the CPU to perform tens of thousands of times of reading and writing from and to the RAM. On the other hand, in hardware processing, 4 bytes (for four colors) were used.
The same processing can be completed only by setting the address. Further, the above-described processing is merely a stack of simple processing, and does not have a very large scale when configuring logic.

In this embodiment, the output address of the ranked Bk data is fixed, but a general-purpose logic may be configured to set the output address.

When the ranked Bk data (rank 1 to rank 4 in this embodiment) is created, the head address of the working buffer storing the Bk data, Y,
The 12-byte data of the head address where the original image of M, C and Bk is stored and the head address where the mask pattern of Y, M, C and BK is stored are transferred to the CPU 2006.
Just by setting the logic 2005, the logical product of each of the Bk data of ranks 1 to 4 and the mask pattern of each color (Y, M, C, Bk), and the logical product data and each color color (Y, M, C) ) Of the original image data and the logical product of the Bk original image data, and a predetermined color (Y, M,
C, Bk) and outputs the result to an address.

As in the logic 2004, each address is automatically incremented in the logic 2005 to generate a desired address and continue the process a predetermined number of times. As a result, the output data enters the print buffers 2000 to 2003 of the actual recording image data for which the replacement process of the pixel at the boundary has been completed.

By implementing the hardware processing as described above, extremely high-speed boundary control means can be established within a practical cost range.

(Embodiment 4) In Embodiments 1 to 3 described above, in order to discriminate the situation of the boundary portion between the color ink dot and the black ink dot finely and perform the minimum necessary dot replacement, the dot of interest (Bk dot ), Different types of ink dots (color dots) existing in the n × m pixel area
Is corrected by a weighting coefficient provided in advance for each pixel and counted, and the data of each rank divided by the counted value is masked with a mask having a predetermined ratio to replace dots. Was.

In the above-described embodiment, when a predetermined mask is applied to the data of the target ink of each rank according to the boundary contact degree, the data of the target ink is set as shown in FIG.
In the case of the regular pattern shown in FIG.

The logical product of the data as shown in FIG. 15A (here, the data in the buffer for storing the degree of boundary contact of rank 2) is obtained by using the mask of Bk and CYAN for rank 2. Then, as shown in FIG. 15C, the upper half data is synchronized with the mask shown in FIG.
It can be seen that the data is only for AN. Also,
About 50% of the data in the lower half, Bk and C
Although it is converted to YAN, it can be seen that it is a regular pattern.

In the present embodiment, a replacement method for preventing such synchronization with a mask when replacing dots with each data ranked according to the boundary contact degree of the target ink will be described.

FIG. 13 is a control block diagram for explaining the present embodiment. This control configuration is different from the configuration shown in FIG. 1 in that a dot position detection unit 1005 for detecting a recording dot from data in the work buffer 1003 is added, and a dot replacement unit 1 is added.
Reference numeral 001 is for performing dot replacement based on the dot position.

FIG. 14 is a flowchart for explaining this embodiment.

The method for replacing dots at the boundary is rank 1
, An n × m pixel mask as shown in FIG. 4 is provided for each rank for the data in the boundary contact degree storage buffer of rank 4, and the mask and the boundary contact degree storage buffer are stored. The logical product (AND) with the data in the buffer is added to or replaced with the original data in the print buffer of each color as dot replacement dots of the original Bk data to obtain actual recording data.

The storage in the buffers 1 to 4 for storing the degree of boundary contact (S300 to S306) is described in the second embodiment in FIG.
Since it is the same as (S200 to S206), the description is omitted.

For simplicity, it is assumed that no data exists in the buffer for storing the degree of boundary contact of ranks 1 to 3, and the original data of 8 × 8 pixels shown in FIG. The description will be made on the assumption that the data is stored in the storage buffer.

First, the dot position detecting means uses a 50% Bk mask (FIG. 15D) to extract Bk data.
4-bit checker {1010} corresponding to Bk)
Prepare Then, the data of the top one raster # 0 in the buffer for storing the degree of boundary contact of rank 4 in FIG.
For 1010101 #, the most significant bits 0 and 1 are determined (S307). If the most significant bit is 1, the logical product (AND) with the most significant bit of the checker is calculated (S
309) Write 1-dot Bk data into the work buffer, rotate the checker one bit to the left to {0101} (S308). If the most significant bit is 0, the Bk data is written to the working buffer as null data, and the checker is not rotated (S
310). Hereinafter, when the same processing is performed, the Bk data after dot replacement of the uppermost one raster is $ 0100010.
0 °. The same processing is performed for eight rasters (S311).

Next, a 50% CYAN mask (FIG. 15)
(D) 4-bit checker corresponding to C) # 010
1} is prepared, and data {0101 of the top one raster in the buffer for storing the degree of boundary contact of rank 4 in FIG.
For 0101 #, the most significant bits 0 and 1 are determined. If the most significant bit is 1, a logical AND (AND) with the most significant bit of the checker is taken, and one dot of CYAN
As data, the checker is rotated one bit to the left to make {1010}. CY if the most significant bit is 0
The AN data is null data, and the checker is not rotated. Hereinafter, when the same processing is performed, the CYAN data after dot replacement of the uppermost one raster is $ 000100.
01｝. The same processing is performed for eight rasters.

In this embodiment, in order to suppress color mixing as much as possible, dot replacement is converted at a rate of 50% for each of Bk and CYAN. However, similar processing is performed by adding Yellow and Magenta, and thereby the recording apparatus or ink is replaced. It is preferable to set the conversion ratio according to the characteristics. When the conversion of all data is completed, the logical sum of each rank in the working buffer is calculated, and the data is added to or replaced with the original print buffer of each of Y, M, C, and K (S312 to S3).
313).

FIG. 15E shows the data of Bk and CYAN after dot replacement by the above method.

As described above, by performing the dot replacement at the boundary using the dot position detecting means, it is possible to prevent the synchronization of the mask occurring at the time of the dot replacement, so that the original Bk image and the color image are retained. Can prevent color mixture at the boundary of the image, and can record high-quality Bk and color images.

(Embodiment 5) In this embodiment, a method for recording a higher quality image by more accurately judging the contact state between the Bk dots and the color dots will be described.

In the two types of boundary areas shown in FIGS. 17 (a) and (b), when the boundary contact degree of the target dot of Bk is calculated, both the boundary contact degrees have substantially the same value as follows. You can see that TYPE1 Boundary contact = 2 * (A + C + E + J) + 2 * (B + G + I) + 4 * (D
+ F + H + K + L) = 1.558 TYPE2 Boundary contact degree = 2 * (2 * (B + C + G + I + J) + 4 * (F + L))
= 1.516 However, in practice, the boundary of TYPE1, which is close to the target dot with 100% duty, is mixed at twice the probability than the boundary of TYPE2, which is close to 50% duty.

In order to solve the above problem, in this embodiment,
N × m around the target dot of Bk (9 × 9 in this embodiment)
The pixel region is divided into a plurality of regions (in this embodiment, four 5 × 5 pixel regions including left, right, upper, and lower sides including the dot of interest), the boundary contact degree is calculated for each of the divided regions, and the boundary contact degree of the four regions is calculated. Is set as the boundary contact degree of the dot of interest, and the data is written to the boundary contact degree storage buffer of the rank corresponding to the boundary contact degree.

The relationship between the boundary contact degree and the rank in this embodiment is shown below. The boundary contact degree of this rank is obtained in Example 2.
Is obtained by dividing the boundary contact degree of each rank by 4.

Rank Boundary contact degree RANK1 0.000 to 0.390 RANK2 0.391 to 0.779 RANK3 0.780 to 1.169 RANK4 1.170 to 1.558

When the boundary contact degree of the dot of interest in the two types of boundary areas shown in FIG. 17 is calculated by the above method, it can be seen that the boundary contact degree matches the ease of color mixing as follows.

TYPE 1 Boundary contact degree of region 1 = A + B + C +
E + G + I + J + 2 * (D + F + H + K + L) = 0.779 Boundary contact degree of area 2 = 0 Boundary contact degree of area 3 = B + G + I + 2 * (A + C + D +
E + F + H + J + K + L) = 1.037 Boundary contact degree of area 4 = A + C + E + J = 0.258 Boundary contact degree of target dot = 1.037... RANK3 TYPE2 Boundary contact degree of area 1 = B + G + I + 2 * (C + J + F + L)
= 0.471 Boundary contact degree of area 2 = B + G + I + 2 * (C + J + F + L) = 0.471 Boundary contact degree of area 3 = B + G + I + 2 * (C + J + F + L) = 0.471 Boundary contact degree of region 4 = B + G + I + 2 * (C + J + F + L) = 0.471 Boundary contact degree of target dot = 0.471... RANK2

FIG. 16 is a flowchart for explaining this embodiment.

When a print start command is issued, the Y, M, C, and Bk data in the print buffer for each color is stored in the work buffer for each color (S400 to S402). The 9 × 9 pixel area around the target dot is divided into four areas (5 × 5 pixels including the target dot), and the boundary contact degree (1Y to 4Y) with respect to Yellow data is obtained for each area. Similarly, the boundary contact degrees (1M to 4M and 1C to 4C) of four regions are calculated for Magenta and Cyan (S40).
3). The largest value among the boundary contact degrees 1Y to 4Y is defined as the boundary contact degree Y, and the boundary contact degree M and the boundary contact degree C are similarly determined (S404). The border contact degree (Y, M, C) for each color is added to make the border contact degree for the dot of interest (S405). A buffer for storing a boundary contact degree corresponding to the determined boundary contact degree (1 to 1)
The data is stored in 4) (S406). Perform the above processing 1
This is performed for the number of lines (S407).

The subsequent processing (S408 to S410) is the same as that in FIG. 6 (S207 to S209) of the second embodiment, and a description thereof will not be repeated.

As described above, when calculating the degree of boundary contact, n × m pixels around the dot of interest (9 × 9 pixels in this embodiment).
9 pixels) area is divided into a plurality (four in this embodiment)
By calculating the boundary contact degree for each of the divided regions and determining the boundary contact degree of the dot of interest based on the value, optimal dot replacement becomes possible, and as a result, high-quality printing becomes possible.

(Embodiment 6) In this embodiment, a method will be described for solving the problem that occurs when the method described in Embodiment 5 is used.

The n × m (9 × 9 in this embodiment) pixel area around the target dot of Bk is divided into a plurality of areas (in this embodiment, 4 × 5 and 5 × 5 pixel areas), and the divided areas The boundary contact degree is calculated for each dot, and the largest value of the boundary contact degrees of the four regions is defined as the boundary contact degree of the dot of interest.
In the case of an image in which the color and the gradation of Bk gradually intersect as shown in FIG. 8, all of the low-duty Bk portions are subjected to dot replacement. However, in the image as shown in FIG. 18, the color mixture at the boundary between Bk and the color is not noticeable to the eye, so that Bk is all True.
It is preferable to record with Black.

In order to solve the above problem, in the present embodiment, the difference between the largest contact degree and the smallest contact degree among the boundary contact degrees of the four divided areas is defined as the boundary contact degree of the dot of interest. The Bk data is written into the buffer for storing the degree of boundary contact corresponding to the degree of boundary contact.

The value described in the fifth embodiment may be used as the relationship between the boundary contact degree and the rank in this embodiment. When the boundary contact degrees of the target dots in the two types of boundary regions shown in FIGS. 17A and 17B are calculated by the above-described method, as shown below, for the dots that do not need to be subjected to dot replacement, the boundary contact degrees are determined. The degree is a value close to 0, and it can be seen that the degree of boundary contact is high for dots to be subjected to dot replacement.

TYPE 1 Boundary contact degree of region 1 = A + B + C +
E + G + I + J + 2 * (D + F + H + K + L) = 0.779 Boundary contact degree of area 2 = 0 Boundary contact degree of area 3 = B + G + I + 2 * (A + C + D +
E + F + H + J + K + L) = 1.037 Boundary contact degree of area 4 = A + C + E + J = 0.258 Boundary contact degree of target dot = 1.037-0 = 1.037... RAN
K3 TYPE2 Boundary contact degree of area 1 = B + G + I + 2 * (C + J + F + L)
= 0.471 Boundary contact degree of area 2 = B + G + I + 2 * (C + J + F + L) = 0.471 Boundary contact degree of area 3 = B + G + I + 2 * (C + J + F + L) = 0.471 Boundary contact degree of area 4 = B + G + I + 2 * (C + J + F + L) = 0.471 Boundary contact degree of target dot = 0.471-0.471 = 0... RAN
K1

As described above, when calculating the boundary contact degree, n × m pixels (9 × 9 pixels in this embodiment)
9 pixels) area is divided into a plurality (four in this embodiment)
By calculating the boundary contact degree for each of the divided areas and subtracting the smallest boundary contact degree from the largest boundary contact degree as the boundary contact degree of the dot of interest, optimal dot replacement becomes possible. High quality recording becomes possible.

(Embodiment 7) In the above embodiment, when the target ink dot is an isolated point or a one-dot ruled line, the mixed color with different types of ink is hardly noticeable on the actual recorded image, but the calculated boundary contact degree is This is a very large value. For this reason,
It is subject to dot replacement, and on the contrary, color misregistration may occur due to mask synchronization or the like.

Therefore, in the present embodiment, even in a situation where the target ink dot forms an isolated point or a one-dot ruled line, optimal dot replacement is performed by detecting the degree of contact of the same ink. .

In the case of an image in which the dots of the target ink having a very low duty exist in the different types of ink as shown in FIG. 20, the boundary contact degree of the target dot of interest of the target ink is calculated. Because of the presence of dots, the value becomes a very large value and becomes a target of the dot replacement position. However, in the case of a single dot such as an isolated point, the degree of color mixing or bleeding does not matter visually even when it is in contact with different types of ink.

[0106] This is because different types of ink dots having normal bleeding adjacent to each other are not mixed alone, but the ink of a plurality of dots connected to the dot overflows and flows to the different type ink dots, so that color mixing or bleeding occurs. That's why.
In the case of a single dot, the degree of bleeding or color mixing is very low because the ink amount itself is small. That is, even if the degree of boundary contact is very large, it is necessary to perform a process of not performing dot replacement with different kinds of ink in the case of an isolated point or a one-dot ruled line.

Therefore, in this embodiment, the boundary contact degree of the target dot with respect to the different ink dots is obtained, and at the same time, the contact degree with the same ink is obtained. The rank of the dot of interest is lowered.

FIG. 19 is a flowchart for explaining this embodiment.

When there is a print start command, Y, M, C, Bk
Store the data in the work buffer (S500-50
3). Subsequently, a boundary contact degree is calculated for each of n × m pixels (9 × 9 in this embodiment) surrounding the Bk target dot (S504). The boundary contact degree (Y, M, C) for each color is added to be the boundary contact degree for the dot of interest (S505).

Next, the number of Bk dots existing in the n × m (5 × 5) pixel area around the dot of interest is counted and set as the Bk contact degree (S506). Here, the Bk contact degree is 5 × 5
Although the number of dots present in a pixel is set, a weighting coefficient may be assigned to each pixel. When the boundary contact degree of the target dot is larger than 4.675 and the BK contact degree is larger than 5, data is stored in the boundary contact degree storage buffer 1 (S50).
7 to S509). Otherwise, the boundary contact degree of the target dot is stored in the boundary contact degree storage buffers (1 to 4) of the rank corresponding to the dot (S510).

When the processing for one line is completed, each PCBk conversion mask (1 to 4) of each color is ANDed with the data in the buffer of each rank (S511), and the color (Y, M, C) Logical OR (OR) of each rank for each color
To obtain the additional data for recording and add it to the original print buffer. After calculating the logical sum (OR) of each rank for Bk, the data is replaced with data in the original print buffer as recording data (S512 to S514).

As described above, even if the degree of contact between the target dot and the different inks is large, the dots are not replaced when the degree of contact with the same ink is small, so that only the necessary dots can be replaced. As a result, high-quality recording can be performed.

Also, the case has been described in which all of the above control means are controlled by the control unit in the printing apparatus. However, all of the control means are executed by a printer driver or the like using resources of an external device, and the pixel replacement processing is performed. It is also possible to extend to a data processing method for receiving actual record data after the completion of. In many cases, the external device connected to the recording device is a personal computer, and a CPU for performing the processing.
PC has better processing capacity and RAM capacity.

Therefore, the object to which the present invention is applied is not limited to the ink jet recording apparatus, but is naturally extended to processing means in an external device having an excellent processing capability such as a personal computer (host computer). is there.

The configuration and operation other than the hardware processing means for executing the boundary contact detection means for different kinds of ink pixels and the pixel conversion means at the boundary part are the same as those of the above-described embodiment, and therefore the description thereof is omitted.

The present invention particularly provides an excellent effect in a recording apparatus using an ink jet recording head which forms flying droplets by utilizing thermal energy and performs recording among ink jet recording systems.

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

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

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

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

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

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

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

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

[0125]

As described above, the present invention detects the degree of contact between different kinds of ink at the boundary where different kinds of ink are close to each other, and replaces the recording pixels with other kinds of ink pixels in accordance with the detected degree of contact. It is possible to replace a recording pixel with another type of ink pixel in accordance with the proximity situation of, and it is possible to perform higher-quality recording while bringing different kinds of ink into close proximity.

Further, it is possible to prevent synchronization with the image pattern by performing the mask processing only when the target dot exists, and to divide the detection of the boundary contact degree into a plurality of regions centered on the dot of interest. By doing so, it is possible to more accurately determine the proximity status between different types of ink,
Further, by simultaneously recognizing the contact state of the same ink, it is possible to perform higher-quality printing while making different inks approach each other, such as not performing dot replacement processing on an isolated point or a one-dot ruled line.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a first embodiment of the present invention.

FIG. 2 is a flowchart illustrating a first embodiment of the present invention.

FIG. 3 is a diagram showing an n × m contact factor according to the first embodiment.

FIG. 4 is a diagram illustrating a PCBk conversion mask according to the first embodiment.

FIG. 5 is a diagram illustrating a character of a color gradation back when the first embodiment of the present invention is implemented.

FIG. 6 is a flowchart illustrating a second embodiment of the present invention.

FIG. 7 is a hardware control configuration diagram for explaining a third embodiment of the present invention.

FIG. 8 is a schematic perspective view showing the configuration of an embodiment of the ink jet recording apparatus of the present invention.

9 is a perspective view of a main part of a recording head of the ink jet cartridge shown in FIG.

FIG. 10 is a block diagram showing a control configuration of each unit of the apparatus configuration of an embodiment of the inkjet recording apparatus of the present invention.

FIG. 11 is a circuit diagram showing details of each unit in FIG. 10;

FIG. 12 is a diagram illustrating a character of a conventional color gradation back.

FIG. 13 is a control configuration diagram for explaining a fourth embodiment of the present invention.

FIG. 14 is a flowchart illustrating a fourth embodiment of the present invention.

FIG. 15 is a diagram illustrating an 8 × 8 mask process described in a fifth embodiment of the present invention.

FIG. 16 is a flowchart illustrating a fifth embodiment of the present invention.

FIG. 17 is a diagram illustrating two types of contact situations described in the fifth embodiment.

FIG. 18 is a diagram of color and Bk gradations for explaining Example 6 of the present invention.

FIG. 19 is a flowchart illustrating a seventh embodiment of the present invention.

FIG. 20 is a diagram illustrating a state of contact between different kinds of ink for explaining a seventh embodiment of the present invention.

[Explanation of symbols]

 Reference Signs List 11 MPU 12 ROM 13 DRAM 14 Gate array 1000 Boundary contact degree detecting means 1001 Dot replacing means 1002 Arithmetic processing means 1003 Work buffer 1004 Print buffer 1005 Dot position detecting means

(72) Inventor Kiichiro Takahashi 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Kazuhiro Nakata 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Takashi Kasahara 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (56) Reference Reference JP-A-5-276373 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B41J 2/21

Claims (16)

(57) [Claims] 1. An ink jet recording apparatus for recording an image by ejecting different types of ink from a recording head to a recording medium to form recording dots, wherein the degree of boundary contact between the recording dots formed by the different types of ink and the target dots is determined. A weighting factor is set for each pixel in an n × m pixel area (n ≧ 1, m ≧ 1) centering on the target dot, and recording dots of different types of ink existing in the pixel area are corrected using the weighting factor. A boundary contact degree detecting means for detecting by detecting the boundary contact degree, and replacing the recording pixels formed by the target dots with recording dots of different kinds of ink in accordance with the boundary contact degree detected by the boundary contact degree detecting means. And an ink jet recording apparatus. 2. The ink jet recording apparatus according to claim 1, wherein the recording pixels formed by the dots of interest are formed by black ink. 3. The replacement means divides a recording dot of the ink of interest into at least two or more ranks according to the value of the boundary contact degree, and sets a predetermined ratio for each of the divided ranks. 2. The ink jet recording apparatus according to claim 1, wherein the recording dots of interest are replaced with recording dots of a different kind of ink. 4. A plurality of replacement mask patterns set at least by the number of divided ranks for each target ink on which dot replacement is performed by the replacement means, and a replacement mask corresponding to each of the divided ranks. It has logical product means for calculating the logical product of the dot replacement position of the pattern and the target ink data, and logical sum means for obtaining the logical replacement of the obtained dot replacement position of each rank to obtain the replacement position of the target ink data. The ink jet recording apparatus according to claim 3, wherein: 5. The boundary contact degree detecting means corrects and counts a recording pixel of one of the different kinds of ink present in the pixel area with the weight coefficient, and counts the number of pixels of the different kind with the target dot. Detecting the degree of border contact with the dots formed by ink and detecting the degree of border contact with the recording dots formed by a plurality of different types of ink for the target dot by adding the degree of boundary contact for the number of different types of ink. The ink jet recording apparatus according to claim 4, wherein the recording is performed. 6. A data receiving means for receiving a presence / absence signal of a recording pixel as binary recording data, wherein the boundary contact degree detecting means and the replacing means are adapted to receive the binary recording data received by the data receiving means. 6. The ink jet recording apparatus according to claim 5, wherein a contact degree detection process and a replacement process are performed on the recording device. 7. A method according to claim 1, further comprising: a position detecting unit configured to detect whether or not a dot exists at a specific position with respect to each of the ink dot data classified according to the boundary contact degree. 5. The ink jet recording apparatus according to claim 4, wherein the dots are replaced with a mask pattern of a predetermined ratio only when the dots are present at a specific position by the position detecting means. 8. The boundary contact degree detecting means divides the pixel area into at least two or more areas, corrects recording dots formed by different kinds of ink existing in each of the divided pixel areas with the weight coefficient, and counts the number of recording dots. 8. The ink jet recording apparatus according to claim 7, wherein the degree of contact between the target dot and a recording dot formed by a different kind of ink is detected. 9. The boundary contact degree detection means, wherein the boundary contact degree detected for each of the two or more divided pixel regions is
9. The ink jet recording apparatus according to claim 8, wherein the maximum value of the boundary contact degree is set as the boundary contact degree of the dot of interest. 10. The boundary contact degree detecting means calculates a difference between a largest one and a minimum boundary contact degree among the boundary contact degrees detected for each of the two or more divided pixel regions. 9. The ink jet recording apparatus according to claim 8, wherein a boundary contact degree of the target dot is set. 11. A similar ink contact degree detecting means for detecting the degree of contact between recording dots made of the same kind of ink, wherein said replacement means detects the degree of contact between the recording dots of different kinds of ink by said boundary contact degree detecting means. 2. An ink jet recording apparatus according to claim 1, wherein the recording pixels are replaced with recording dots of different kinds of ink in accordance with the degree of contact between recording dots of the same kind of ink by said same kind of ink contact degree detecting means. 12. The same kind ink contact degree detecting means includes an n × m pixel area (n ≧ 1, m ≧ 1) centered on a dot of interest.
12. The ink jet recording apparatus according to claim 11, wherein the number of recording dots of the same kind of ink existing in the pixel area is counted to detect the degree of contact between the noted dot and the recording dot formed by the same kind of ink. . 13. An ink jet recording apparatus according to claim 11, wherein said replacement means performs replacement with a different kind of ink in accordance with a degree of contact with a recording dot formed by said same kind of ink. 14. The ink jet recording apparatus according to claim 1, wherein the recording head discharges the ink by heat. 15. An ink jet recording method for recording an image by ejecting different kinds of ink from a recording head to a recording medium to form a recording dot, wherein the boundary contact degree between the recording dot formed by the different kind of ink and the dot of interest is determined. A weighting factor is set for each pixel in an n × m pixel area (n ≧ 1, m ≧ 1) centering on the target dot, and recording dots of different types of ink existing in the pixel area are corrected using the weighting factor. And replacing the recording data of the recording pixels formed by the noted dots with data corresponding to recording dots of different kinds of ink in accordance with the degree of boundary contact detected by the detection step. And ejecting ink based on the print data replaced by the replacement step. The ink jet recording method. 16. A print data processing method for discharging a different kind of ink from a print head to a print medium to form a print dot and print an image, wherein a boundary contact between a print dot formed by the different kind of ink and a dot of interest is provided. A weight coefficient is set for each pixel in an n × m pixel area (n ≧ 1, m ≧ 1) centering on the dot of interest, and recording dots of different kinds of ink existing in the pixel area are assigned the weight. A step of detecting by correcting by a coefficient and counting; and, in accordance with the degree of boundary contact detected in the detecting step, the recording data of the recording pixel formed by the noted dot is data corresponding to the recording dot of the different kind of ink. Recording data processing method.