JPH06135015A - Ink jet reocrding method - Google Patents

Abstract

PURPOSE:To make white part in decimated part unobtrusive for any recording image by processing image information corresponding to a predetermined region along a predetermined print region as information requiring no delivery of recording liquid droplet. CONSTITUTION:An input data is converted to data corresponding to respective colors of YMCK (S1) and a decision is made whether a pixel of interest is present or not. If there is a record data, the flow advances to S4 thence to S5 with the pixel of interest as delivery data. A decision is made whether the record data of the pixel of interest is based on code information at S5 and if the record data is based on code information, the flow advances to S6 where a decision is further made whether the record data of adjacent pixel is based on code information. If the answer is YES, the flow advances to S7 where a decision is made whether the adjacent pixel has same color as the pixel of interest. When the answers at S6, S7 are YES, the flow advances to S8 otherwise advances to S9 where the adjacent pixel is processed as a non-delivery data regardless of the recording data thereof.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet recording method, and more particularly to an ink jet recording method for recording a multicolor image using ink droplets of a plurality of colors.

[0002]

2. Description of the Related Art Conventionally, recording is performed by using three color inks of yellow (Y), magenta (M) and cyan (C), or four color inks to which black (Bk) is added if necessary. In the ink jet recording method to be performed, a recording medium for quickly drying and fixing the adhered ink has been required.

If the adhering ink is slow to dry and fix, and the admixture of adjacent ink droplets on the recording medium occurs at the boundary between different-color printing areas, the boundary becomes blurred and an unclear image is formed. . This phenomenon is called bleeding.

On the other hand, as a method of solving the above bleeding problem without using a specific recording medium, by controlling the image information and not printing the dots in a predetermined area forming the boundary, A method of preventing the ink bleeding has also been proposed.

For example, in Japanese Patent Laid-Open No. 3-146355, it is adjacent to the fore color. There is shown a method (recording apparatus) in which ink is not applied to pixel dots of the background color, and the portions are left as blank areas. In this method, the image information is divided into a foreground portion (outer surface) and a background (lining = background) in advance, and the image information is divided into a foreground portion and a background portion for actually deleting the image information.

[0006]

However, the above specification does not describe a method for specifically distinguishing the foreground portion and the background portion from a specific image. Actually, one print area is surrounded by the other print area so that the print boundary portions of different colors are not always formed,
In many cases, they are simply adjacent. In this case as well, the boundary bleeding occurs, but in the case where they are simply adjacent to each other, the foreground portion and the background portion cannot be specified, so that there is a problem in which printing area to thin out the corresponding pixel dot.

As a method of designating a print area to be thinned out, there is a method of designating a color. As one example, there is a method of thinning out the corresponding pixel dots from the printing area of the higher lightness color adjacent to the lower lightness color. For example, the boundary between the Bk and Y print areas is adjacent to the Bk dot. By thinning out so that Y of image dots is not recorded, it is possible to suppress the occurrence of bleeding and
There is an advantage that the white parts are not noticeable.

A problem in this case is that a character (alphabet, character, kanji, etc.) in a color with a high brightness surrounded by a print area of a color with a low brightness is printed.
In this case, if the adjacent pixel dots are thinned out from the print area of the character portion, white voids occupy most of the character portion, and there is a problem that the color forming the character cannot be discriminated.

An object of the present invention is to make the pixel dots forming the color boundary part into a white blank without ink injection (thinning out) so that both inks adjacent to each other in the color boundary part influence each other. Therefore, it is an object of the present invention to provide an ink jet recording method capable of preventing ink bleeding and thereby obtaining a high quality image without selecting a recording medium.

Further, another object of the present invention is to provide a thinning-out method in which the white spots in the thinning-out portion are inconspicuous with respect to any recorded image, even if the thinning-out method is not selected depending on the recorded image. An object of the present invention is to provide an inkjet recording method capable of obtaining a high-quality image.

[0011]

Therefore, according to the present invention,
In an ink jet recording method for recording an image on a recording medium by ejecting recording liquid droplets of a plurality of colors based on image information, in the image, a predetermined area along a print area defined by code information The image information corresponding to
A feature of the present invention is that recording control is performed to perform processing for making information that does not eject recording droplets.

Further, in the image, in the color boundary of the print area not corresponding to the code information, at least the image information corresponding to the predetermined area along the color boundary of the black (Bk) print area is not ejected. It is characterized in that recording control is performed to perform information processing.

[0013]

With the above structure, it is possible to provide a clear image with no white bleeding without causing bleeding, even for images having any combination of shapes and colors without using a special recording medium. Since the periphery of the code information is thinned out regardless of the combination of colors, the problem that the colors forming characters (characters, alphabets, kanji) cannot be discriminated as a result of thinning control does not occur.

[0014]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a perspective view of a conventional color ink jet recording apparatus according to the present invention. In FIG. 1, the carriage 1 is moved in parallel on the lead screw 4 and the guide shaft 5 by the lead screw 4 which is interlocked with a carriage motor 508 (not shown). The print head 2 is fixed on the carriage 1, and the cartridge guide 3
A removable color cartridge 10 and a black cartridge 11 are attached along with and ink is supplied.

The ink ejected from the print head 2 lands on a recording medium facing the print head 2, that is, the recording paper 6 to form an image. The recording paper 6 includes a paper feed roller 7, a paper discharge roller 8 that interlock with a paper discharge motor (not shown),
The paper pressing plate 9 discharges the paper in association with the printing.

FIG. 2 shows the details of the carriage 1. The color cartridge 10 and the black cartridge 11 are attached from the rear of the print head 2 and supply ink from the pipes 204, 205, 206 and 207 shown in FIG. The color cartridge 10 includes cyan, magenta, and yellow inks in one housing, and the respective inks are separated by a partition wall.

FIG. 3 shows the details of the print head 2. 201
Is a silicon substrate that forms a heater and other elements related to the inkjet ejection principle. A printed circuit board 202 includes a drive circuit for the print head 2. An aluminum plate 203 includes a silicon substrate 201 and a printed circuit board 202. 204, 2
Reference numerals 05, 206, and 207 are pipes for supplying the ink from the color cartridge 10 and the black cartridge 11 to the ejection portion of the print head 2 through the distributor 208. 2Y, 2M, 2C, and 2Bk are nozzle groups that eject yellow, cyan, magenta, and black inks, respectively. In the print head 2 according to the present invention, the nozzles of each color are arranged in a line. The number of nozzles for each color is 24 for 2Y, 24 for 2M, 24 for 2C, and 2B.
Let k be 64. Then, the nozzles 2Y and 2M, the nozzle 2
Between M and 2C, the nozzles 2Y, 2M, 2C, and 2Bk are provided at intervals of 8 nozzles at the same pitch. Nozzle 2
Similarly, 16 nozzles are provided between C and 2Bk.

The direction in which the carriage 1 moves along the lead screw 4 and the guide shaft 5 is called the main scanning direction. Also,
The head nozzles of each color are arranged in a direction perpendicular to the main scanning direction, and the arrangement direction is called a sub-scanning direction.

FIG. 11 shows the nozzles 2Y, 2M, 2C and 2B.
The internal details of k are shown. Electrothermal energy conversion elements (heaters) 223 are formed on a substrate 221 made of silicon or the like at equal intervals along with wiring through the same steps as those for semiconductors, and a resin layer is laminated between the heaters 223 to form partition walls 228. , The liquid path forming member 227 on the plate is joined on each partition wall 228, and the top plate 225 such as glass is joined on the member.
22, a liquid passage 226 and a common liquid chamber 224 are formed.

FIG. 12 illustrates the principle of ink ejection from one nozzle of the print head 2.

(A) Discharge standby state. 223a is ink.
223b is a liquid channel.

(B) A state in which the ink discharge heater 223 is heated by an electric signal and bubbles 223c are generated.

(C) The electric signal is continuously supplied to the heater 223.
And the bubbles 223c are growing.

(D) A state in which droplets of the ink 223a are ejected.

(E) The heater 223 is electrically disconnected, and the ink 223a is refilled up to the ejection port of the nozzle. In the above process, it is desired that the temperature rise of the heater 223 rises sharply and at the same time the temperature rise of the ink 223a in the vicinity of the heater 223 follows up, so that good bubble generation is performed. It is not always possible to realize an ideal ejection state only by applying a single-phase electric pulse. Therefore, a method of preliminarily maintaining the temperature around the nozzle 223b before heating the heater and a method of applying a pulse as a preheat pulse immediately before an electric pulse for bubble generation are adopted.

5 to 7 schematically show images recorded by the above-described color ink jet recording apparatus, and 10 × 10 pixels are recorded in a frame. In the figure, ◯ represents Bk dots, and X represents Y dots.

When recording was performed as shown in FIG. 5 (a), bleeding occurred at the Bk and Y print boundary, the boundary became unclear, and only an image of poor quality was obtained.

FIG. 5 (b) is one of the embodiments of the present invention, and is an example in which one dot of the image dots in the Y print area adjacent to the Bk dot at the boundary is thinned out.

FIG. 5C similarly adjoins the Y dot at the boundary. In this example, pixel dots in the Bk print area are thinned out one by one.

When printing was performed in the same manner as shown in the schematic diagrams of FIGS. 5B and 5C, bleeding did not occur and a high-quality image was obtained. However, in the case of the method of FIG. 5C, white voids at the boundary were conspicuous as compared with the method of FIG. 5B.

FIG. 6A is a schematic diagram of a portion in which the Bk character of the alphabetic character "A" based on the code information is printed in the Y printing area. FIG. 6B is one of the embodiments of the present invention, and is an example in which pixel dots in the Y print area adjacent to the Bk dot at the boundary are thinned out one by one.

Using the same method as described above, FIG.
Printing was performed as shown in (a) and (b). Figure 6
The image based on (a) had bad bleeding and the image quality of the character A was poor, whereas the image based on FIG. 6 (b) had no bleeding and a clear A character could be confirmed in the Y background. It was

FIG. 7A shows Y and B in FIG. 6A.
The print area of k is reversed. Similarly, FIG.
(B) is adjacent to the Y dot of the character "A" printed based on the code information. This is one of the embodiments of the present invention in which one Bk dot in the background is thinned out. On the other hand, FIG. 7C is a schematic diagram in the case where Y dots and one dot in the character "A" adjacent to the background Bk dot are thinned out. When printing was performed in the same manner, as shown in FIG.
In the method (a), the character A was in an unreadable state. In the method of FIG. 7, a clear Y character “A” was confirmed in the Bk background. On the other hand, in the method of FIG. 8, the character "A" was legible, but the edge was unclear and the quality was poor, and the color Y of the character "A" could not be confirmed because the code information was thinned out.

As described above, in the color boundary of the area printed by the code information, a vivid color character is printed by constantly thinning and recording the surrounding area.

Next, the operation of the present invention will be described with reference to the flowchart shown in FIG.

Step S1 of the flowchart shown in FIG.
First, the input data is converted into data corresponding to each color of YMCK.

In step S2, the presence or absence of the pixel of interest is determined. If there is no recorded data, go to step S3,
The pixel of interest is non-ejection data for which printing is not performed, and the process proceeds to step S8. If there is print data in step S2, the process proceeds to step S4, the ejection data is set for the target pixel, and the process proceeds to step 5.

In step S5, it is determined whether or not the recording data of the pixel of interest is data based on code information.

If the recorded data is not code information,
In step S8, if the adjacent pixel has print data, the adjacent pixel is set as ejection data, and if the adjacent pixel does not have print data, it is set as non-ejection data. That is, no special processing is performed on the data of the adjacent pixels.

When the process of step S3 is performed, the process similarly proceeds to step S8.

If the pixel of interest is the data based on the code information in step 5, the process proceeds to step S6, and it is determined whether the recording data of the adjacent pixel is the data based on the code information. Further, in the case of Yes in step S6, the process proceeds to step S7, and it is determined whether or not the color of the adjacent pixel is the same as the pixel of interest.

If both steps S6 and S7 are Yes, that is, if the recording data of the adjacent pixel has the same color as the pixel of interest or code information, the process proceeds to step S8, and otherwise, to step S9. Go ahead.
In step S9, regardless of whether or not there is print data for the adjacent pixel, the adjacent pixel is treated as non-ejection data.

After the processes of steps S8 and S9, the process proceeds to step S10, the head drive circuit 14 is driven, and the recording operation is performed by the recording head 15.

Steps S2 to S9 are the drive data creation routine shown in the present invention.

FIG. 9 is a block diagram of a color ink jet recording apparatus applicable to the present invention. 92 inputs the input data to Y.Y. M. C. YMCK conversion circuit for converting data of each color corresponding to four colors of Bk, drive data creation circuit 93
Is steps S2 to S9 of the flowchart shown in FIG.
Process. The head drive circuit 94 drives the recording head 95 based on the drive data of each color by the drive data creation circuit 93.

With the above-described structure, clear color characters can be printed.

(Other Embodiments) In the embodiments of the present invention,
Regarding the character recorded based on the code information, the method of thinning out the dots around the character has been explained. Furthermore, for the part other than the code information, the dots around the pixel adjacent to Bk are thinned and recorded using the conventional method. May be. By thinning out dots of other colors adjacent to Bk, a clear image in which white bleeding portions are not conspicuous is formed without further bleeding.

An example of a suitable color ink jet recording apparatus is shown in FIG. In this device, ejection openings corresponding to the respective colors of ink are arranged in a vertical line. The present invention is not limited to this, and can be applied to a color ink jet recording apparatus in which an example of the ejection openings of each color is horizontally arranged as shown in FIG. In FIG. 10A, multi-nozzles (eg 128
Nozzle) recording heads 121 to 124 are arranged in parallel, the head 121 is black (Bk), the head 122 is cyan (C), the head 123 is magenta (M), and the head 124 is yellow (Y). Discharge. Ink of each color is supplied to each recording head from the ink tank 4 via the flexible pipe 3, and each of the recording heads is provided via flexible insulating belts 151 to 154 in which a large number of conductive wires are arranged and embedded. A nozzle drive signal is supplied. On the other hand, the carriage 101 is placed on the two guide rails 108 and descends to form an endless belt 109 connected to the carriage 101.
Is driven by the pulse motor 110 to cause the carriage 101 to reciprocate in the X direction to perform main scanning. Also,
The recording paper 112 is stretched by roller pairs 113 and 114, and the pulse motor 115 connected to one of the roller pairs 114 feeds the recording paper 112 in the Y direction to perform sub scanning. As described above, a color image or character is recorded on the recording paper 112.

FIG. 10B shows the recording heads 121 to 12.
It is a figure which shows the discharge port part of 4. 132 is a discharge port 131
Is a discharge port surface for forming. The rows of the ejection openings 131 are provided almost vertically to the carriage 101, and
Recording is performed by scanning in the same direction as the X direction shown in (a).

The method of the present invention using the above apparatus identifies the boundary portion in the image based on the input image information, and if either one of the print areas is based on the code information, White the area around the code information,
If there is nothing based on the code information, the area adjacent to the print area of a specific color (for example, Bk) is set to white blank.

In the present invention, if there is no code information, it is preferable that at least the area adjacent to the Bk printing area is blank.

In the above-mentioned embodiment, the area where white dots are formed is an example of pixel dots along the color boundary, but the application of the present invention is not limited to this, and the amount of ink to be ejected is taken into consideration. It is also possible to make it a desired area.

Although the method utilizing heat energy has been described as the color ink jet recording apparatus to which the present invention is applicable, a mechanical ink jet recording apparatus utilizing vibration such as piezo may be used.

The present invention also relates to a recording head of the type that utilizes heat energy, especially in the ink jet recording system,
In a recording device, it has an excellent effect.

Regarding its typical structure and principle, see, for example, US Pat. Nos. 4,723,129 and 4740.
What is done using the basic principles disclosed in 796 is preferred. This method is a so-called on-demand type,
It can be applied to any of the continuous 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 corresponding to the recorded information and giving a rapid temperature rise exceeding nucleate boiling, heat energy is generated in the electrothermal converter, and film boiling is caused 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. By the growth and contraction of the bubbles, liquid (ink) is ejected through the ejection opening,
Form at least one drop. 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 US Pat. No. 62 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 discharge port, the liquid passage, and the electrothermal converter (the straight liquid passage or the right-angled liquid passage) as disclosed in the above-mentioned 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.

[0058]

According to the method of the present invention as described above, at the color boundary of the area printed by the code information, the surrounding area is always white, so that bleeding does not occur. No matter what background color is created, vividly colored characters (alphabets, kanji, etc.) are printed.

Further, at least in the portion other than the code information, the peripheral dots adjacent to Bk are made white blank, so that a clear image in which there is no bleeding and the white blank portion is inconspicuous is formed.

As a result, it becomes possible to obtain a high-quality image without using a specific recording medium having an excellent ink absorbing ability as the recording medium.

[Brief description of drawings]

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

FIG. 2 is a detailed view of a carriage mounted in the inkjet recording apparatus according to the present invention.

FIG. 3 is a detailed view of an inkjet head.

FIG. 4 is an internal detailed view of an inkjet head.

FIG. 5 is a pixel dot configuration diagram of a recorded image.

FIG. 6 is a pixel dot configuration diagram of a recorded image.

FIG. 7 is a pixel dot configuration diagram of a recorded image.

FIG. 8 is a flowchart showing the operation of the present invention.

FIG. 9 is a block diagram of an inkjet recording apparatus according to the present invention.

FIG. 10 is a diagram showing another inkjet recording apparatus to which the present invention is applicable.

FIG. 11 is a diagram illustrating the ejection principle of an inkjet head.

[Explanation of symbols]

 1 Carriage 2 Print Head 3 Cartridge Guide 92 YMCK Conversion Circuit 93 Drive Data Creation Circuit 94 Head Drive Circuit

Claims (2)

[Claims] 1. An inkjet recording method for recording an image on a recording medium by ejecting recording liquid droplets of a plurality of colors based on image information, wherein a print area defined by code information in the image. An ink jet recording method, wherein recording control is performed so that image information corresponding to a predetermined area along the line is treated as information that does not eject the recording droplets. 2. In the image, the image information corresponding to a predetermined area along the color boundary of the black (Bk) print area is ejected at the color boundary of the print area not corresponding to the code information. The ink jet recording method according to claim 1, further comprising: recording control for performing a process of setting information not to be recorded.