JPH06152899A - Color ink jet recording method - Google Patents

Abstract

PURPOSE:To realize the compatibility of black ink with respective kinds of color ink in high quality color recording without ink blotting by separating a character from a picture and using both black and color ink at the time of recording a black character. CONSTITUTION:Data is transferred from a host computer 306 and data stored in a reception buffer 307 is read by a system controller 301. When black color data is added in read data and the black data is transmitted by a character code, black data is distributed to a Bk buffer 309 and the Y, M and C buffers 309Y, 309M and 309C. When black color data is not transmitted by the character code, black data is written in the Y, M and C buffers. When black color data is not added in read data, color data is written in the Y, M and C buffers. Then, recording is operated based on the contents of the respective color buffers.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color ink jet recording method capable of recording a color image clearly and with high density, and more specifically, yellow (Y), magenta (M), cyan (C) and black (Bk) inks. And a color inkjet recording method using the same.

[0002]

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

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

In the conventional ink jet recording method, it was necessary to use a special paper having an ink absorbing layer in order to obtain a color image of high color development without ink bleeding.
In recent years, a method has been put into practical use, which has improved aptitude for printing on plain paper, which is used in large quantities in printers, copying machines, etc., by improving ink. However, the printing quality on plain paper has not yet reached a sufficient level. The biggest factor is
Both ink bleeding between colors and black recording quality (especially black characters and fine line recording quality) are compatible.

Usually, when a color image is obtained on a plain paper by an ink jet recording method, a quick-drying ink having a high penetration speed into the plain paper is used. For this reason, the image does not have ink bleeding between each color, but the density is low overall, and around the recorded image area of each color, a small amount of ink bleeds along the fibers of the paper, so-called feathering occurs. It's easy to do.

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

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

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

[0009]

As means for solving these problems, characters and images are treated separately, black characters are recorded with black ink having excellent recording quality, and images are colored with a high penetration speed. A method of recording using ink is conceivable.

However, in the above method, for example, when a black character is recorded on a color background, the background color is recorded with color ink and the character is recorded with black ink, which causes bleeding. was there.

On the other hand, in the above-mentioned case, bleeding can be prevented by carrying out all recording with a combination of color inks, but in this case, the density of black characters is low and the character quality is deteriorated. Remains.

The present invention has been made in order to solve the above-mentioned problems of the prior art, and its purpose is to maintain sharp black recording quality of characters and fine lines while
The aim is to achieve high-quality color recording without ink bleeding between black and each color.

[0013]

In order to achieve this object, the present invention distinguishes characters from images in a color ink jet recording method for recording using a plurality of colors of ink including black ink, When recording black characters, it is characterized in that both black ink and color ink are used for recording.

As a result, bleeding between black and color is reduced.

[0015]

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

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

Guide shafts 104, 1 carrying a print head 102 of a carriage 101 and a cartridge guide 103.
05 can be scanned (driving not shown).

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

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

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

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

The silicon substrate and the printed circuit board 202 are provided on the same aluminum plate 203, and the pipes 204 to 2 protruding parallel to the aluminum plate 203.
Reference numeral 07 projects from a plastic member 208 called a disc distributor that is vertically stretched with respect to the silicon substrate, and further communicates with a flow path inside thereof, which flow path communicates with a common liquid chamber.

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

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

The components of the used ink are as follows. 1. Y (yellow) C.I. I. Direct Yellow 86 3 parts Diethylene glycol 10 parts Isopropyl alicol 2 parts Urea 5 parts Acetylenol EH (Kawaken Chemical) 1 part Water balance 2. M (magenta) C.I. I. Acid Red 289 3 parts Diethylene glycol 10 parts Isopropyl alcohol 2 parts Urea 5 parts Acetylenol EH (Kawaken Chemical) 1 part Water balance 3. C (cyan) C.I. I. Direct Blue 3 parts Diethylene glycol 10 parts Isopropyl alcohol 2 parts Urea 5 parts Acetylenol EH (Kawaken Chemical) 1 part Water balance 4. Bk (black) C.I. I. Direct Black 154 3 parts Diethylene glycol 10 parts Isopropyl alcohol 2 parts Urea 5 parts Water balance

As described above, the C, M and Y inks have improved penetrability by adding 1% of acetylenol EH to the Bk ink. In addition to this, other additives include other surfactants, alcohols and the like.

FIG. 3 is an electrical control block diagram of the color ink jet recording apparatus described above.

Reference numeral 301 denotes a system controller for controlling the entire apparatus, which has a storage element (RO) in which a control program including a microprocessor is housed.
M), a memory element (RAM) and the like used when the microprocessor performs processing are arranged.

Reference numeral 302 is a driver for driving the print head in the main scanning direction, and similarly 303 is a driver for moving in the sub scanning direction. 304 and 305 are motors corresponding to the driver, which are speeds from the driver,
It operates by receiving information such as travel distance.

A host computer 306 is a device for transferring information to be printed to the printing device of the present invention.

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

Reference numeral 308 is a frame memory for expanding the data to be printed into image data, and has a memory size for printing. In this embodiment, a frame memory capable of storing one print sheet will be described, but the present invention is not limited to the size of the frame memory.

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

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

Reference numeral 311 designates heads 312Y, 312M for the respective colors,
A driver for driving the 312C and 312Bk, which is controlled by a signal from the print control unit 310.

FIG. 4 is a flow chart showing the printing operation of the first embodiment. Further, FIG. 5 is a diagram for explaining a processing state of recording data.

In this embodiment, the data sent from the host in the form of code information is discriminated as a character, and the pixels forming the character according to a specific pattern are ejected with Y, M, C color ink and black ink. It is divided into pixels.

Further description will be given below.

In STEP 1, the host computer 30
The system controller 301 reads the data transferred from No. 6 and stored in the reception buffer 307.

At STEP 2, it is determined whether or not the read data includes black data. If black data is included, the process proceeds to STEP 3, and if not, the process proceeds to STEP 6.

At STEP 3, it is determined whether or not the black data is the data sent by the character code. If yes, the process goes to STEP 4, and if not, the process goes to STEP 5.

In STEP 4, the black data is transferred to the Bk buffer (309K) and the Y, M, C buffers (309Y, 30).
9M, 309C). As a method of this distribution, as shown in FIG. 5, 50% of the data is stored in the Bk buffer according to the checker pattern and the remaining 50
% Data is distributed to each of the Y, M and C buffers.

In STEP 5, black data is set to Y, M, C.
Write to the buffer.

In STEP 6, the color data is set to Y, M,
Write to C buffer.

In STEP 8, the recording operation is performed based on the contents of each color buffer.

In the above embodiment, the black data is distributed to the Bk buffer and the Y, M, and C buffers by 50% according to the checker pattern in STPE4, but the pattern for dividing the pixels is not limited to this. It may be randomly divided.

(Second Embodiment) Next, a second embodiment of the present invention will be described. In this embodiment, as in the first embodiment, the data sent from the host as the code information is discriminated as a character, and if there is other color data in the adjacent position of the black character data, all the pixels forming the character are Y, M. , C color ink, and at the same time, 1 / n (1/4 in this embodiment) pixels are randomly selected and black ink is ejected. Further description will be given below.

Using the same apparatus as in Example 1, recording is performed according to the print operation flowchart of FIG.

In STEP 11, the host computer 3
The data is transferred from 06, and the system controller 301 reads the data stored in the reception buffer 307.

At STEP 12, it is judged whether or not the read data includes black data. If black data is included, the process proceeds to STEP 13. If not, STEP 12 is performed.
Proceed to 16.

At STEP 13, it is judged whether or not the black data is the data sent by the character code, and if so, the operation goes to STEP 14, and if not, the operation goes to STEP 14.
Proceed to 16.

At STEP 14, it is judged whether or not there is data of another color at the position adjacent to the black data, and if so, the procedure goes to STEP 15, otherwise, STEP 16 is performed.
Go to.

At STEP 15, the black data is distributed to the Bk buffer and the Y, M and C buffers. As a method of this distribution, all black data is written in the Y, M, and C buffers, and 25% of randomly selected data is written in the Bk buffer.

In STEP 16, the black data is set to Y, M,
Write to C buffer.

In STEP 17, the color data is Y,
Write to M and C buffers.

In STEP 19, the recording operation is performed based on the contents of each color buffer.

According to the method of this embodiment, the color is not adjacent to any other color (that is, there is no fear of bleeding).
Black characters are recorded only with black ink, so
Character quality is improved.

In the above embodiment, the pixels on which the black ink is ejected are randomly selected, but the pixels on which the black ink is ejected may be selected according to a specific pattern.

(Embodiment 3) Next, a third embodiment of the present invention will be described. In this embodiment, a character area and an image area are discriminated by image recognition, and when it is discriminated as a black character, Y, M, and C color inks are applied to all the pixels forming the character, and 1 / n of that ( In the present embodiment, one-fourth (1/4) pixels are randomly selected and black ink is ejected. Further description will be given below.

Using the same apparatus as in Example 1, recording is performed according to the flowchart showing the printing operation of FIG.

In STEP 21, the host computer 3
The data is transferred from 06 and the system controller 301 reads the data stored in the reception buffer 307.

At STEP 22, it is judged whether or not the read data includes black data. If black data is included, the process proceeds to STEP 23. If not, STEP 22 is performed.
Proceed to 26.

At STEP 23, the image area and the character area are discriminated by a known image processing method. If it is the image area, proceed to STEP 25. If it is the character area, proceed to STEP 24. In this embodiment, this processing is performed by software by an internal program in the system controller 301, but in order to perform the processing at higher speed, an electric circuit that is hardware is provided and the processing is performed by this. You may

At STEP 24, the black data is distributed to the Bk buffer and the Y, M and C buffers. As a method of this distribution, all black data is written in the Y, M, and C buffers, and 25% of randomly selected data is written in the Bk buffer.

In STEP 25, the black data is set to Y, M,
Write to C buffer.

In STEP 26, the color data is Y,
Write to M and C buffers.

At STEP 28, the recording operation is performed based on the contents of each color buffer.

According to the method of this embodiment, it is possible to perform high-quality recording even for black characters developed into bit data on the host side or black characters read by a scanner.

In the first to third embodiments, the black ink is applied to a part of all the pixels forming the black character. However, when the black ink is applied to all the pixels forming the black character, Y, M, and You may make it eject C color ink.

Further, in the above embodiments, the recording head uses the ink jet recording method in which the thermal energy generated from the electrothermal converter is used to generate bubbles in the ink, and the action of the bubbles causes the ink to fly. As described above, it goes without saying that the present invention is also applicable to a so-called piezo type inkjet recording system in which the ink is ejected by causing a state change in the ink by using mechanical energy generated from the electromechanical transducer.

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

[0072]

As described above, according to the present invention, when a character and an image are distinguished and a black character is recorded, both black ink and color ink are used for recording. It is possible to realize high-quality color recording without ink bleeding between each color of black and color while maintaining the quality.

[Brief description of drawings]

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

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

FIG. 3 is a block diagram of an inkjet recording apparatus control circuit to which the present invention is applicable.

FIG. 4 is a flowchart illustrating the operation of the embodiment.

FIG. 5 is a schematic diagram illustrating the operation of the first embodiment.

FIG. 6 is a flowchart illustrating the operation of the second embodiment.

FIG. 7 is a flowchart illustrating the operation of the third embodiment.

[Explanation of symbols]

101 Carriage 102 Print Head 103 Cartridge 104 Guide Shaft 105 Guide Shaft 106 Recording Paper 107 Paper Feed Roller 108 Paper Feed Roller 109 Paper Press Plate 110 Color Ink Cartridge 111 Black Ink Cartridge 201 Silicon Substrate 202 Printed Circuit Board 203 Aluminum Plate 204 to 207 Distributor 208 Plastic member 301 System controller 302 Carriage motor driver 303 Paper feed motor driver 304 Carriage motor 305 Paper feed motor 306 Host computer 307 Receive buffer 308Y, 308M, 308C, 308Bk Frame memory for each color 309Y, 309M, 309C, 309Bk Data buffer for each color 310 Print control unit 311 Print dry 312Y, 312M, 312C, 312Bk each color of the print head

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

Claims (5)

[Claims] 1. A color ink jet recording method for recording using a plurality of colors of ink including a black ink, in which a character and an image are distinguished, and when recording a black character, both the black ink and the color ink are used. A color ink jet recording method, wherein recording is performed using the color ink jet recording method. 2. The color ink jet recording method according to claim 1, wherein when an image other than characters is recorded, only the color ink is used for recording. 3. The color ink jet recording according to claim 1, wherein when a black character is recorded, the pixels forming the black character are divided into a pixel for ejecting the black ink and a pixel for ejecting the color ink. Method. 4. When recording a black character, the color ink is applied to all the pixels forming the black character, and the black ink is applied to a part of the pixels forming the black character. Color inkjet recording method. 5. The color ink jet recording method according to claim 1, wherein an ink droplet is ejected by causing a state change in the ink by using thermal energy to perform image recording.