JP2688269B2 - Color inkjet recording method and apparatus - Google Patents

Description

TECHNICAL FIELD The present invention relates to a color ink jet recording method and apparatus, and more specifically, Y (yellow), M (magenta), C
The present invention relates to a color inkjet recording method and apparatus capable of color recording using a recording head that ejects (cyan) and BK (black) inks.

[Prior Art] In this type of conventional color ink jet recording apparatus, a dedicated coated paper has been used for each recording material.
Therefore, as long as such a dedicated coated paper is used, droplets of color ink corresponding to the bleeding rate of the dedicated coated paper are ejected from the ink ejection port of each recording head, so that absorption and fixing are appropriately performed. So there is no problem. This is because the bleeding rate of the dedicated coated paper is determined according to the droplet obtained from the recording device used.

[Problems to be Solved by the Invention] However, as described above, if the dedicated coated paper is always used for color recording by the color inkjet recording apparatus, not only is the coated paper relatively expensive as compared with the plain paper, Coated paper cannot be said to be superior to plain paper in that it tends to curl, and is excellent in writability and light resistance, and moreover, the type of coated paper used is limited. In particular, recently, the fixing property of a monochrome type ink jet recording device has been significantly improved and has been put to practical use. However, in the case of a color ink jet recording device, the fixing property in a color mixing portion is realized by color overlapping of single color inks. Since this is a system, the amount of ink applied to the same pixel is 200% for a single color, and there is a possibility that the desired fixability cannot be obtained.

The object of the present invention is to focus on the problems in the color recording method in the color inkjet recording apparatus described above, and to solve the problems, improve the fixability by devising the ink ejection procedure, and make it a dedicated coated paper. To provide a color ink jet recording method and apparatus capable of increasing the recognition of a black recording portion without causing bleeding in a color mixing portion even on plain paper having low ink absorption characteristics without limitation. is there.

[Means for Solving the Problems] The color inkjet recording method of the present invention is
In a color ink jet recording method capable of color recording on a recording material while scanning a recording head having ink ejection openings for ejecting magenta, yellow and black inks along the recording material, image data is recorded. Accordingly, when performing recording in a predetermined black recording region of the recording material, recording is performed by ejecting the amount of black ink to be ejected from the recording head to the black recording region in a plurality of times of scanning, When recording in a predetermined color mixture recording area of the recording material according to image data, recording is performed by ejecting a combination of the cyan, magenta, and yellow inks from the recording head, and recording in the black recording area. It is characterized in that the number of scans for performing the above is greater than the number of scans for performing recording in the color mixture recording area.

The color inkjet recording apparatus of the present invention is
In a color ink jet recording apparatus capable of color recording on a recording material while scanning a recording head in which ink ejection ports capable of ejecting magenta, yellow and black ink are arranged along the recording material, image data is recorded on the recording material. Accordingly, when performing recording in a predetermined black recording region of the recording material, recording is performed by ejecting the amount of black ink to be ejected from the recording head to the black recording region in a plurality of times of scanning, When recording in a predetermined color mixture recording area of the recording material according to image data, recording is performed by ejecting a combination of the cyan, magenta, and yellow inks from the recording head, and recording in the black recording area. And a control means for controlling the number of scans for performing the scanning to be greater than the number of scans for performing recording in the color mixture recording area. And wherein the door.

[Operation] According to the present invention, the number of scans for black color recording is set to be greater than the number of scans for color mixture recording, thereby suppressing the occurrence of bleeding in the color mixture recording unit even on plain paper and the like.
The black recording area is made to stand out clearly for clear recording.

[Example] Hereinafter, an example of the present invention will be described in detail and specifically with reference to the drawings.

FIG. 1 shows an example of a color ink jet recording apparatus for carrying out the present invention. Here, 1 is the main body of the recording device,
Reference numeral 2 denotes a recording head unit including a recording head 2A for black (BK), a recording head 2B for cyan (C), a recording head 2C for magenta (M) and a recording head 2D for yellow (Y). Is a carriage that carries the recording head unit 2 and moves. The carriage 3 is connected to the belt 4 and is moved along the guide shaft 5 by a motor (not shown). 6 is a platen that guides a recording material (normal coated paper or film for overhead projector (OHP)) 7 inserted from the direction of arrow A to the recording position, holds and feeds the sheet, and can eject in the direction of arrow B after recording. Is.

The recording heads 2A to 2D, the respective drive motors, etc. are controlled by signals from the control unit 8, 9 is a host device such as a personal computer for operating the entire recording device via the control unit 8, and 10 is The panel is provided with a display means, various mode switches, and switches including inputs.
FIG. 2 shows a state in which the sheet 7 of the recording material is inserted into the recording apparatus 1 as shown by the chain double-dashed line.

In the color ink jet recording apparatus configured as described above, the recording material 7 held by the platen 6 is supplied to each of the recording heads 2A to 2D at a predetermined timing during the movement of the carriage 3 according to a recording signal. Each time a color ink is ejected and printing for one scan is completed, the platen 6
The sheet is fed by and the recording is repeated. Thus, when the recording on the recording material is completed, the platen 6 ejects in the direction of arrow B.

By the way, when performing color recording on the recording material 7, the density and quality of the image output on the recording material 7 differ depending on what kind of bleeding characteristic is used for the recording material 7. Will end up. Therefore, in the present embodiment, recording can be performed in different modes depending on the type of the recording material 7 selected by the user having a low ink absorption capacity, or the type of coated paper or the like that sufficiently absorbs ink. These modes are selected by a printer command from the host device 9 or a switch or the like via the operation panel 10. Depending on the mode selection, the method of ejecting ink and the procedure thereof may be different, and appropriate for each mode. So that a good ink drop ejection can be obtained.

FIG. 3 shows the configuration of a circuit for performing the above-described operation according to the present invention, and FIGS. 4A and 4B show examples of the arrangement of the operation switches on the panel 10 in which the mode can be set as described above. Show. In FIG. 3, 21 is a host device 9
, 22 is a drive system for driving sources such as the carriage 3 and the platen 6, and 23 is a head drive system in which the drive of each recording head 2A to 2D is controlled via the control unit 8 according to a designated mode. is there. In FIGS. 4A and 4B, 10A is an online switch, 10C is a set switch used when setting in the memory of the control unit 8, and 10D.
Is a mode switch used when designating a mode, and the mode can be set by a combination operation as described below. Of course, it is possible to set a command.

Therefore, in the case of a direct command from the host device and 9, the "on line" switch 10A shown in FIG. 4A or 4B is turned on. In the case of operating the panel 10, if it is the panel 10 shown in FIG. 4A, for example, after turning on the (ON LINE) on-line switch 10A, turn on the (SET) set switch 10C. Further, when the (LF) line feed switch 10E is turned "on", the coated paper mode is set in which the single color Y, M, C and black characters are also struck once. In case of the panel 10 shown in FIG. 4B, the on-line switch 10A is turned "off", the (MODE) mode switch 10D is turned "on", the set switch 10C is turned "on" n times, and a display is added to change the display. In accordance with the above, for example, it is assumed that the coated paper mode described above is set at a certain number
The mode may be set by turning "on" again.

Also, in the case of the black emphasis mode setting for emphasizing black for the black characters on the plain paper or the like having a low ink absorption capacity, for example, in the case of the panel 10 shown in FIG. 4A, the on-line switch “off” is set. Then, the set switch 10C is operated "on" a plurality of times, and the line feed switch 10E is turned "on" to obtain the setting. Also,
In the case of the panel 10 shown in FIG. 4B, for example, the set switch 10
By operating C, it is possible to set the black enhancement mode at a specific display.

By the way, in the case of color recording by an on-demand type ink jet recording apparatus as applied to this embodiment,
There is still a problem in color reproducibility such as full color, but even if it solves the fixing property as described above, it is sufficiently practical for plain paper with low bleed rate as well as dedicated coated paper. Color recording is possible. However, what is important for color recording on such plain paper is, for example, in the case of a recorded image as shown in FIG.
The black character print portion BP and the black contour are recorded so that they can be clearly read or discriminated, and the other color print portions CP need only be clear for each color. that way,
A sufficient effect can be obtained as a material.

However, as mentioned above, the amount of ink applied is 200% in the mixed color area of R (red), G (green) and B (blue) due to the color overlap, and in the black area, it is applied for emphasis. The same is true when they are piled up, and plain paper cannot absorb the ink completely, and the colors become blurred and unclear, or the printed surface becomes dirty.

The recording method of the present invention focuses on the problems as described above, and provides the effect of delicate thin line recording obtained through the high-precision ink ejection port of the recording device itself for the printing portion such as black characters. For effective use, dots are printed on all the pixels in dot units that compose data based on the dot data. However, for the R, G, and B color mixed color print units, dots are thinned By performing the driving, the ink is easily absorbed in the blank portion formed around the ink.

FIG. 6 shows a distribution form of recording dots according to the first embodiment of the present invention. In this example, the unit of data is decomposed into a plurality of (2 × 2) pixels, and recording is performed based on each data. Here, the circle indicates that the data originally exists including the broken line and the solid line. The solid circles indicate the dots on which ink is actually ejected in this example. That is, according to this example, during the first scanning by the recording heads 2A to 2D, as shown in (A), the inks of BK, Y, M, and C are added to the diagonal positions of the analyzed pixels. Dots are hit. Note that R, G, and B of the mixed colors are Y, M, and C color overlaps, and therefore, they are superimposed and printed at the same place during the first scanning, but as shown in the drawing, the circles with broken lines are opposite. Since no ink dots are printed at the diagonal positions, the ink dots are left blank, and the margins into which the ink is soaked are left. Therefore, the ink does not overflow and the fixability is improved.

Also, during the second scan, only the ink dots of BK are printed in opposite diagonal positions as shown in (B). In the black print part, all pixels of data formation are On the other hand, dots will be printed solidly,
It is possible to prevent the loss of black data, to make black printing and the like noticeable, and to stabilize the fixability without lowering the density of R, G, and B of the mixed colors.

FIG. 7 shows a distribution form of recording dots according to the second embodiment of the present invention. This example is an example of a case where the data unit is decomposed into (3 × 3) pixels. In the case of this example, the first
In the second scan, as shown in (A), BK and Y, M, and C are respectively imprinted with ink dots in a pattern indicated by a solid circle, and in the second scan, only BK (( Ink is applied to the pixels indicated by the broken line circles in A). Therefore, in addition to the black enhancement, the margins into which the ink penetrates for the R, G, and B dots due to the Y, M, and C color overlaps are maintained, and the fixability can be improved.

FIG. 8 shows the distribution of recording dots according to the third embodiment of the present invention. In this example, the dot data of each ink to be printed when the plain paper mode is set is uniquely determined, and each pixel is composed of an n × n (2 × 2 in this example) matrix for the data. In addition, 100% of each color is printed against the minimum resolution of the recording head, and the fixing property is improved.

In this example, while the minimum resolution is 360dpi,
An example of performing color recording with a pixel density of 180 dpi is shown. Therefore, first, in the first scan, as shown in (A), ink is ejected at one diagonal position with respect to Y, M, C, and BK of single colors, and R, G, and B of mixed colors are obtained. On the other hand, color overlapping is performed based on the dot data developed for Y, M, and C. Then, in the second scan, ink is ejected to BK, Y, M, and C at the other diagonal position that is different from the time of printing in the first scan, and dot data is sent from the host device. The obtained data is, for example, the GA (gate array of the control unit
LSI) will be used by expanding.

(Others) The present invention brings about an excellent effect particularly in a recording head and a recording apparatus of a bubble jet system among ink jet recording systems. This is because according to such a method, it is possible to achieve higher density and higher definition of recording.

As for the representative configuration and principle, it is preferable to use the basic principle disclosed in, for example, US Pat. Nos. 4,723,129 and 4,740,796. This method can be applied to both the so-called on-demand type and the continuous type. In particular, in the case of the on-demand type, it is arranged corresponding to a sheet or a liquid path holding a liquid (ink). Applying at least one drive signal corresponding to the recording information and providing a rapid temperature rise exceeding nucleate boiling to the electrothermal transducer, thereby causing the electrothermal transducer to generate thermal energy, thereby causing the recording head to emit heat energy. This is effective because a film in the liquid (ink) corresponding to the driving signal can be formed one by one by causing film boiling on the heat acting surface. The liquid (ink) is ejected through the ejection opening by the growth and contraction of the bubble to form at least one droplet. 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. U.S. Pat. No. 44
Those described in JP-A-63359 and JP-A-4345262 are suitable. Further, when 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.

As a configuration of the recording head, in addition to a combination configuration (a linear liquid flow path or a right-angled liquid flow path) of a discharge port, a liquid path, and an electrothermal converter as disclosed in the above-mentioned specifications, A configuration using U.S. Pat. No. 4,558,333 and U.S. Pat. No. 4,459,600, which disclose a configuration in which is disposed in a bending region, is also included in the present invention. In addition, Japanese Unexamined Patent 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 opening 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 surely 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 recording head integrally formed.

In addition, even with the serial type printer as in the above example, the recording head fixed to the main unit or attached to the main unit enables electrical connection with the main unit and supply of ink from the main unit. The present invention is also effective when a replaceable chip type print head or a cartridge type print head having an ink tank provided integrally with the print head itself is used.

Further, it is preferable to add recovery means for the print head, preliminary auxiliary means, and the like provided as a configuration of the printing apparatus in the present invention since the effects of the present invention can be further stabilized. If these are specifically mentioned, capping means for the recording head, cleaning means, pressurizing or suction means, preheating means using an electrothermal transducer or another heating element or a combination thereof, Performing a preliminary ejection mode in which ejection is performed separately from printing is also effective for performing stable printing.

Regarding the type or number of print heads to be mounted, for example, in addition to one provided for single color ink, a plurality of print heads are provided corresponding to a plurality of inks having different print colors and densities. May be used. 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 extremely effective for an apparatus provided with at least one of full colors by color mixture.

In addition, in the embodiments of the present invention described above, the ink is described as a liquid. However, an ink that solidifies at or below room temperature and softens or liquefies at room temperature, or the ink itself in an inkjet method. In general, the temperature is controlled 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. I just need. In addition, the temperature rise due to thermal energy can be positively prevented by using it as energy for changing the state of the ink from a solid state to a liquid state, or ink that solidifies in a standing state to prevent evaporation of the ink can be used. In any case, the ink is liquefied by the application of the thermal energy according to the recording signal, and the ink is liquefied, and the liquid ink is discharged. The present invention is also applicable to a case where an ink that liquefies for the first time by energy is used. The ink in such a case is disclosed in
-56847 or JP-A-60-71260, while being held as a liquid or solid in a porous sheet recess or through hole, facing the electrothermal converter It is good also as a form. 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 may be used as an image output terminal of an information processing apparatus such as a computer, a copying apparatus combined with a reader or the like, or a facsimile apparatus having a transmission / reception function. Or the like.

[Effects of the Invention] As described above, according to the present invention, when the black recording area is recorded according to the recording data, the amount of black ink to be ejected from the recording head to the black recording area is set a plurality of times. The black recording area and the color-mixed recording area are made to be the same by making the number of scans for discharging the black recording area larger than the number of scans for recording the black recording area. It is possible to perform recording on the recording material by the optimum number of scans.

That is, by ejecting the black ink amount to the black recording region by dividing the ink amount into a plurality of scans, the ink is not ejected from the recording material even if the recording material has a low ink absorption property. It is possible to improve the fixability of the ink without overflowing and to make the black recording portion more conspicuous. On the other hand, the mixed color recording area has a peculiarity that a desired recorded color cannot be obtained if the time interval for mixing them is too long because recording is performed by mixing a plurality of color inks. For the area, the number of scans for printing is set to be smaller than the number of scans for printing in the black print area, so that a plurality of scans are performed as compared with the case where the same number of scans as in the black print area is performed. The time interval for mixing the color inks can be shortened, and a desired recording color can be obtained.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an example of the configuration of a color ink jet recording apparatus to which the present invention can be applied, FIG. 2 is a perspective view showing the external appearance of a recording apparatus of the same form as FIG. 1, and FIG. FIG. 4A and FIG. 4B are configuration diagrams of a control circuit for implementing the recording method of FIG. 4, FIG. 4A and FIG. 4B are configuration diagrams of an operation panel relating to the implementation of the present invention, and FIG. 5 is an example of a color print on a recording material. FIG. 6, FIG. 7, FIG. 7 and FIG. 8 schematically show the ink dot forming modes according to the first, second and third embodiments of the present invention, respectively. 1 ... Color inkjet recording device, 2A-2D ... Recording head, 3 ... Carriage, 7 ... Recording material, 8 ... Control unit, 9 ... Host device, 10 ... Operation panel.

Claims (7)

(57) [Claims] 1. A color ink jet capable of color recording on a recording material while scanning a recording head having ink ejection openings for ejecting cyan, magenta, yellow and black inks along the recording material. In the recording method, when recording on a predetermined black recording area of the recording material according to image data, the amount of black ink to be ejected from the recording head to the black recording area is divided into a plurality of scans. Recording is performed by discharging, and when recording is performed in a predetermined color mixture recording area of the recording material according to image data,
Printing is performed by ejecting a combination of magenta and yellow inks, and the number of scans for printing the black print area is greater than the number of scans for printing the mixed color print area. Color inkjet recording method. 2. The number of scans for recording in the mixed color recording area is one, and the number of scans for recording in the black recording area is plural. Color inkjet recording method. 3. The color ink jet recording method according to claim 1, wherein the number of scans for single color recording by the recording head ejecting each of the cyan, magenta and yellow inks is plural. 4. The ink is ejected from the recording head so that when a plurality of scans are performed for recording in the black recording area, a predetermined pixel is divided into a plurality of scans for recording. The color inkjet recording method according to claim 1. 5. The color inkjet recording method according to claim 1, wherein the recording head includes a thermal energy generator that generates thermal energy for ejecting ink. 6. A color ink jet capable of color recording on a recording material while scanning a recording head having ink ejection openings for ejecting cyan, magenta, yellow and black inks along the recording material. In the recording apparatus, when recording is performed on a predetermined black recording area of the recording material according to image data, the amount of black ink to be ejected from the recording head to the black recording area is divided into a plurality of scans and ejected. By performing the recording, when recording in a predetermined color mixture recording area of the recording material according to image data,
A control unit that performs recording by ejecting a combination of magenta and yellow inks, and that controls the number of scans for recording in the black recording area to be greater than the number of scans for recording in the mixed color recording area A color inkjet recording apparatus comprising: 7. The color ink jet recording apparatus according to claim 6, wherein the recording head includes a thermal energy generator that generates thermal energy for ejecting ink.