JP3774607B2 - Inkjet recording method and recording apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an ink jet recording method and a recording apparatus capable of forming an image on a recording medium by ejecting at least a first color ink and a second color ink from a recording head. More specifically, the present invention relates to a process for adjusting the first color ink dots and the second ink dots so as to overlap each other on the recording medium.
[0002]
[Prior art]
With the spread of information processing equipment such as copying machines, word processors, computers, and communication equipment, digital images are recorded by an inkjet method as one of output devices for image formation (recording) of those equipment. Inkjet recording apparatuses are rapidly spreading. In such a recording apparatus, in order to improve the recording speed, a recording head in which a plurality of ink discharge nozzles are integrated and arranged uses a plurality of ink discharge ports and a plurality of liquid passages, and more recently color-compatible. As the number of the recording heads progresses, many of them are provided with a plurality of the recording heads at the same time.
[0003]
The ink-jet recording system is a non-contact system that performs dot recording by causing ink, which is a recording liquid, to land on a recording medium such as paper as flying droplets, and is low noise. In addition, high-resolution and high-speed recording is possible by increasing the density of the ink discharge nozzles, and even for recording media such as plain paper, no special processing such as phenomenon or fixing is required, and the price is low. Since it is possible to obtain a high-quality image, its use is becoming widespread in recent years. In particular, an on-demand type ink jet recording apparatus is promising for future demand because it can be easily colored and the apparatus itself can be miniaturized and simplified. In addition, with the spread of colorization as described above, higher image quality and higher speed are increasingly required.
[0004]
As a method for achieving high image quality, for example, from the viewpoint of ink bleeding and the robustness of a recorded image, a method of recording by discharging ink and a treatment liquid insolubilizing the ink onto a recording medium is known. That is, the fixability is improved by superimposing two kinds of liquids having different properties. The treatment liquid includes a colorless one and a colored one. In particular, when the treatment liquid is colored, inks of different colors (first color and second color) are overlapped. .
[0005]
[Problems to be solved by the invention]
In the case where the fixing property is improved by overlapping the inks of different colors as described above, the ink dots of different colors are overlapped based on the recording data input to the recording apparatus. However, when the data format of the recording data is multi-value data, the dot overlap between different colors is not uniquely determined, and the dot development has to be performed once. This will be described with reference to FIG.
[0006]
FIG. 17 shows density data (density = 0, density = 1, density = 2, density = 4) input to the printing apparatus and dot arrangement corresponding to the density data. For example, if the density = 1, there are four dot arrangements. If an X color dot with density = 1 and a Y color dot with density = 1 are to be overlapped, the dot arrangement (1) is selected for the X color and the dot arrangement (2) is selected for the Y color. Occurs. In this case, the X and Y dots do not overlap. When the dot arrangement of (1) is selected for the X color, the dots do not overlap unless the dot arrangement of (1) is selected for the Y color as well. In such a multi-value data format, dots between different colors do not necessarily overlap, so first expand the dots, then determine whether they overlap, and if they do not overlap Processing to change the dot arrangement must be done.
[0007]
If processing is performed after dot development is performed in this way, there is a problem that the processing time becomes longer than when processing is performed without performing dot development.
[0008]
The present invention has been made paying attention to the above problems, and an ink jet recording method capable of performing an adjustment process for superimposing the first color ink and the second color ink without performing dot development, and An object is to provide a recording apparatus.
[0009]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides a second color which improves the fixability of the first color ink to a recording medium by contacting the first color ink and the first color ink. An ink jet recording method for recording an image by bringing color ink into contact with at least part of the same unit area on a recording medium, the first density data corresponding to the first color ink and the second density data A step of inputting second density data of a plurality of bits corresponding to inks of the following colors;
A first ejection step of ejecting the first color ink from a recording head and the first color ink are ejected to a plurality of unit areas corresponding to the input first density data. Determining whether or not to increase the density level of the input second density data corresponding to the unit area for at least a part of the plurality of unit areas; and A process of increasing the density level of the second density data in order to bring the first color ink and the second color ink into contact in the unit area when it is determined to perform the process of increasing the density; A step of generating dot data for ejecting the ink of the second color based on the second density data that has been subjected to the process of increasing the density level, and based on the generated dot data. And a second ejection step of ejecting the second color ink from the recording head to at least a part of the plurality of unit regions, and ejected in the first ejection step. The first color ink and the second color ink ejected in the second ejection step have a dot diameter X of the first color ink and a dot diameter Y of the second color ink. The contact is made in the same unit region so as to satisfy the relationship of X> Y.
[0010]
The present invention also records the second color ink that improves the fixing property of the first color ink to the recording medium by contacting the first color ink and the first color ink. An ink jet recording apparatus that records an image by contacting at least part of the same unit area on a medium, the first density data corresponding to the first color ink and the second color ink The first color ink is ejected from the recording head to the unit for inputting the corresponding second density data of a plurality of bits and the plurality of unit areas corresponding to the input first density data. For the at least part of the plurality of unit areas from which the first color ink is ejected and the first control means for controlling, the inputted second density data corresponding to the unit area To increase the concentration level When the unit for determining whether or not to perform the process and the process for increasing the density level is determined, the first color ink and the second color ink are in contact with each other in the unit region. Based on the means for increasing the density level of the second density data and the second density data subjected to the process for increasing the density level, dot data for ejecting the ink of the second color is generated. And a second control means for controlling the ink of the second color to be ejected from the recording head to at least some of the plurality of unit areas based on the generated dot data. And the first color ink ejected by the first control means and the second color ink ejected by the second control means have a dot diameter of the first color ink. X and the second Characterized in that the dot diameter Y color ink contact with way the same unit area satisfy X> Y the relationship.
[0011]
According to another aspect of the present invention, there is provided a second color ink that improves the fixability of the first color ink to a recording medium by contacting at least the first color ink and the first color ink. An inkjet recording apparatus that records an image on a recording medium by ejecting from a recording head, wherein at least a part of a plurality of pixels recorded based on density data of a first color corresponds to the pixel And determining means for determining whether or not there is density data of the second color represented by a plurality of bits, and if the determination means determines that the density data of the second color does not exist, the pixel The density data changing means for increasing the density level of the density data of the second color in order to overlap the ink dots of the first color and the ink dots of the second color, and processing by the data changing means Means for generating dot data of the second color based on the density data of the second color, and means for generating dot data of the first color based on the density data of the first color The first color ink dots recorded based on the generated first color dot data and the second color recorded based on the generated second color dot data The ink dots overlap at the pixels, and the diameter of the first ink dot is larger than the diameter of the second ink dot.
[0012]
According to another aspect of the present invention, there is provided a second color ink that improves the fixability of the first color ink to a recording medium by contacting at least the first color ink and the first color ink. An ink jet recording method for recording an image on a recording medium using a second color density data represented by a plurality of bits corresponding to the pixel for pixels recorded based on the density data of the first color Determining whether the density level of the second color is equal to or higher than a predetermined level, and if it is determined that the density level of the density data of the second color is not higher than the predetermined level, the density level of the density data of the second color is determined. A process of generating a second color dot data based on the second color density data subjected to the process, and a first color density data based on the first color density data. Create dot data of 1 color And the second color recorded based on the generated first color dot data and the second color dot data generated based on the generated first color dot data. Color ink dots overlap in the pixels, the diameter of the first ink dot is larger than the diameter of the second ink dot, and the density level of the density data of the second color is equal to or higher than a predetermined level. If it is determined that the density level of the second color is not, the process for increasing the density level of the density data of the second color is not performed.
[0013]
According to another aspect of the present invention, there is provided a second color ink that improves the fixability of the first color ink to a recording medium by contacting at least the first color ink and the first color ink. An inkjet recording method for recording an image on a recording medium by discharging from a recording head, wherein at least some of the plurality of pixels recorded based on density data of the first color correspond to the pixels A determination step for determining whether or not there is density data of the second color represented by a plurality of bits, and if it is determined in the determination step that density data of the second color does not exist, the pixel A density data changing step for increasing the density level of the density data of the second color in order to superimpose the ink dots of the first color and the ink dots of the second color, and the second in which the process is performed The color of Generating the second color dot data based on the degree data, and generating the first color dot data based on the density data of the first color. The first color ink dots recorded based on the first color dot data and the second color ink dots recorded based on the generated second color dot data overlap in the same pixel. In addition, the diameter of the first ink dot is larger than the diameter of the second ink dot.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.
[0018]
(First embodiment)
FIG. 1 is a three-dimensional perspective view showing a main part of an ink jet recording apparatus according to an embodiment of the present invention. In FIG. 1, reference numeral 1 denotes a replaceable integrated ink cartridge in which an ink tank and a recording head 8 (IJH) are integrated. Specifically, the ink cartridge 1 is composed of four recording heads and tanks that eject inks of four colors of black (K), cyan (C), magenta (M), and yellow (Y), respectively. . In the above description, the head and the tank are integrated. However, the head and the tank may be detachable from each other. In this case, when the ink in the tank runs out, only the tank corresponding to the lost ink can be replaced. Of course, only the head can be replaced as needed. 2 is a carriage that carries the ink cartridge 1 and reciprocates in the a and b directions, 3 is a carriage motor (CR motor) that reciprocates the carriage 2 in the a and b directions, and 4 is a control from a control circuit (not shown). A flat cable for inputting signals and image signals to the recording head, 5 is a platen, 6 is a transport motor (LF motor) for rotating the platen 5 to transport a recording medium 9 (recording paper), and 7 is a recording head. This is a recovery mechanism that recovers the suction of the recording head by capping the front surface of the recording head and sucking the inside of the cap.
[0019]
Now, a plurality of nozzles are arranged in the recording head 8. During the recording operation, the recording head 8 is subjected to main scanning in the a and b directions (main scanning direction), and ink is selectively ejected from these nozzles. Is done. Further, each time the recording head performs main scanning once, the recording paper is conveyed by an amount smaller than the recording head in the P direction (sub scanning direction) substantially orthogonal to the main scanning direction. By repeating such main scanning of the recording head and sub-scanning of the recording sheet, one page is recorded.
[0020]
Next, a printer control circuit configuration for executing the above-described printer recording control will be described. FIG. 2 is a circuit block diagram showing the configuration of the control circuit of the ink jet recording apparatus. In FIG. 2, 211 is an external interface circuit that inputs a recording signal from a host computer main body (not shown), 212 is a CPU that controls the operation of the entire inkjet recording apparatus, 213 is a program ROM that stores a control program executed by the CPU 212, Reference numeral 214 denotes a RAM (for example, a dynamic RAM) for storing various data (such as the recording signal and recording data supplied to the head). Reference numeral 215 denotes a nonvolatile memory for storing various data such as setting contents of the operation panel. As an EEPROM.
[0021]
An operation panel (not shown) installed in the ink jet recording apparatus is provided with an operation key 217, an LCD (not shown), and an LED 219. An operation using the operation key 217 is input to the CPU 212 via the input control circuit 216. The lighting and blinking of the LCD and LED 219 are controlled via the output control circuit 218 in accordance with the operation of the CPU 212. Reference numeral 220 denotes a head drive control circuit that outputs control data from the CPU 212 to the head driver. The head driver drives the recording head 8 based on the output from the head drive control circuit 220. By this driving, ink is ejected from each nozzle of the recording head. Reference numeral 221 denotes an LF motor drive circuit for controlling the LF motor 6, and 222 denotes a carriage motor drive circuit for controlling the carriage motor 3.
[0022]
FIG. 3 is a view showing the structure of the ink jet head 8 (8K, 8C, 8M, 8Y) used in the ink jet recording apparatus in FIG. Although it has been described above that four inkjet heads are provided corresponding to the four colors Bk, C, M, and Y, these four heads have the same structure. A structure of one of these four heads is shown as a representative.
[0023]
In FIG. 3, the inkjet head 8 is schematically configured from a heater board 104 that is a substrate on which a plurality of heaters 102 for heating ink is formed, and a top plate 106 that is placed on the heater board 104. . A plurality of discharge ports 108 are formed in the top plate 106, and a tunnel-like liquid path 110 communicating with the discharge ports 108 is formed behind the discharge ports 108. Each liquid path 110 is isolated from an adjacent liquid path by a partition wall 112. Each liquid passage 110 is commonly connected to one ink liquid chamber 114 at the rear thereof, and ink is supplied to the ink liquid chamber 114 via an ink supply port 116, and the ink is supplied from the ink liquid chamber 114. The liquid is supplied to each liquid passage 110.
[0024]
The heater board 104 and the top plate 106 are aligned so that each heater 102 comes to a position corresponding to each liquid passage 110 and assembled in a state as shown in FIG. Although only two heaters 102 are shown in FIG. 3, the heaters 102 are arranged one by one corresponding to the respective liquid paths 110. When a predetermined drive pulse is supplied to the heater 102 in the assembled state as shown in FIG. 3, film boiling occurs in the ink on the heater 102 to form bubbles, and the ink is discharged from the discharge port 1008 by the pressure of the bubbles. It is pushed out and discharged. At this time, the volume of the ejected ink can be controlled to some extent by controlling the drive pulse applied to the heater 102.
[0025]
FIG. 4 is a diagram for explaining a method of controlling the ink discharge amount by changing the drive pulse applied to the heater. Here, two types of constant voltage pulses are applied to the heater 102 in order to adjust the ink discharge amount. As shown in FIG. 4, the two pulses are a preheat pulse and a main heat pulse (hereinafter simply referred to as a heat pulse). The preheat pulse is a pulse for warming the ink prior to actually ejecting the ink, and is set to a value shorter than the minimum pulse width t5 necessary for ejecting the ink. Therefore, ink is not ejected by this preheat pulse. By adjusting the length of the preheat pulse, it is possible to vary the ink discharge amount.
[0026]
On the other hand, the heat pulse is a pulse for actually ejecting ink, and is set longer than the minimum pulse width t5 necessary for ejecting the ink. Since the energy generated by the heater 602 is proportional to the width (application time) of the heat pulse, it is possible to adjust variations in the characteristics of the heater 602 by adjusting the width of the heat pulse.
[0027]
The ink discharge amount can also be adjusted by adjusting the interval between the preheat pulse and controlling the heat diffusion state by the preheat pulse.
[0028]
As can be seen from the above description, the ink discharge amount can be controlled by adjusting the application time of the preheat pulse and the heat pulse, or by adjusting the application interval of the preheat pulse and the heat pulse. Is also possible. In the present invention, it is possible to adjust the ink discharge amount as necessary.
[0029]
FIG. 5 is a diagram showing the nozzle arrangement in the recording head 8. In FIG. 5, 8 (K), 8 (C), 8 (M), and 8 (Y) are recording heads for ejecting black, cyan, magenta, and yellow inks, respectively. A plurality of nozzles are arranged in each head, and the number of nozzles is 128 for the black head and 256 for the cyan, magenta, and yellow heads.
[0030]
FIG. 5 shows nozzle diameters and nozzle pitches in a black ink head and cyan, magenta, and yellow ink heads (hereinafter referred to as color ink heads). As can be seen from FIG. 5, the nozzle diameter of the black head is 2r with respect to the nozzle diameter r of the color ink head. Further, the nozzle pitch of the black head is 2L with respect to the nozzle pitch L of the color head. As described above, in the recording head of FIG. 5, the nozzle diameter of the black head is twice that of the color head, and the nozzle pitch of the black head is twice that of the color head. The ink discharge amount is controlled so that the ink discharge amount from each nozzle in the black head is approximately four times the ink discharge amount from each nozzle in the color head. In the present embodiment, recording is performed using a recording head as shown in FIG.
[0031]
Here, the ink ejected from the recording head will be described. As the ink used in this embodiment, an ink whose fixing property is improved by reacting different colors is used. Below, the example of an anionic ink and a cationic ink is given as the example.
[0032]
The head 8K discharges an anionic black ink having the composition shown below.
[0033]
(black)
5 parts by weight of thiodiglycol
5 parts by weight of glycerin
4 parts by weight of isopropyl alcohol
5 parts by weight of urea
C. I. Food black 3 parts by weight
Water balance
[0034]
The heads 8C, 8M, and 8Y eject cationic cyan ink (C), cationic magenta ink (M), and cationic yellow ink (Y) having the following compositions, respectively.
[0035]
(cyan)
10 parts by weight of diethylene glycol
2 parts by weight of isopropyl alcohol
5 parts by weight of urea
1 part by weight of acetylenol EH
C. I. 3 parts by weight of Basic Blue 75
Water balance
(Magenta)
10 parts by weight of diethylene glycol
2 parts by weight of isopropyl alcohol
5 parts by weight of urea
1 part by weight of acetylenol EH
C. I. 3 parts by weight of basic violet 7
Water balance
(yellow)
10 parts by weight of thiodiglycol
10 parts by weight of glycerin
3 parts by weight of polyallylamine
(Weight average molecular weight 1000)
Cationic activator 0.5 parts by weight
(Sanyo Kasei G50)
Acetylenol EH 0.25 parts by weight
C. I. 2 parts by weight of basic yellow 21
Water balance
[0036]
According to the combination of the black ink and the color ink described above, the black ink is anionic and the cyan (C), yellow (Y), and magenta (M) inks are cationic. When in contact with or mixed with, both colorants become insoluble or agglomerated. This improves the fixability.
[0037]
In the mixing of the black ink and the color ink described above, in the present invention, as a result of mixing the black ink and the color ink described above on the recording medium or at a position where the ink penetrates to some extent in the recording medium, as a first step of the reaction, Among the cationic substances contained in the ink, low molecular weight components or cationic oligomers and anionic compounds used in water-soluble dyes or pigment inks having an anionic group used in black ink are ionic. As a result of the interaction, an association occurs, and an instantaneous separation occurs from the solution phase. As a result, dispersion failure occurs in the pigment ink, and a pigment aggregate is formed.
[0038]
Next, as the second stage of the reaction, the association of the above-mentioned dye and the low molecular weight cationic substance or cationic oligomer or the aggregate of the pigment is adsorbed by the polymer component contained in the treatment liquid. The size of the dye aggregates or pigment aggregates generated in the above is further increased, making it difficult to enter the gaps between the fibers of the recording medium, and as a result, only the liquid part separated into solid and liquid is soaked into the recording medium. Both image quality and fixability are achieved.
[0039]
Therefore, the fixing property can be improved by bringing the anionic black ink and the cationic color ink into contact with each other. At the same time, aggregates or pigment aggregates formed of low molecular weight components of cationic substances or cationic oligomers, anionic dyes and cationic substances produced by the mechanism described above have increased viscosity, Since they do not move with movement, even when adjacent ink dots are formed of different colors as in the formation of a full-color image, they do not mix with each other and bleeding does not occur. The aggregate is essentially water-insoluble, and the formed image has perfect water resistance. In addition, the light fastness of the image formed by the polymer shielding effect is also improved.
[0040]
As used herein, the term “insolubilization” or “aggregation” refers to the action of insolubilizing or aggregating a coloring material such as a dye or pigment in the ink.
[0041]
In carrying out the present invention, it is not necessary to use a cationic polymer substance having a large molecular weight or a polyvalent metal salt as in the prior art, or the effect of the present invention is further improved even if it is necessary to use it. Since it is only necessary to use it supplementarily to improve it, the amount of use can be minimized. As a result, the present invention eliminates the deterioration of the color developability of the dye, which has been a problem when trying to obtain a water resistance effect using a conventional cationic polymer substance or a polyvalent metal salt. Can be cited as an effect.
[0042]
The recording medium used for carrying out the present invention is not particularly limited, and so-called plain papers such as copy papers and bond papers conventionally used can be suitably used. Of course, a coated paper specially prepared for inkjet printing and a transparent film for OHP can also be suitably used, and general high-quality paper and glossy paper can also be suitably used.
[0043]
The present invention is not limited to making the black ink anionic and the color ink cationic as described above, and vice versa. That is, the black ink may be cationic and the color ink may be anionic. An example of this is shown below.
[0044]
For example, as the black ink, a cationic black ink having the following composition can be used.
[0045]
(black)
10 parts by weight of thiodiglycol
10 parts by weight of glycerin
4 parts by weight of isopropyl alcohol
3 parts by weight of polyallylamine
(Weight average molecular weight 1000)
Kayacel Black CN 2.5 parts by weight
(Nippon Kayaku Co., Ltd.)
Water balance
[0046]
For example, an anionic cyan ink (C), an anionic magenta ink (M), or an anionic yellow ink (Y) having the following composition can be used as the color ink.
[0047]
(cyan)
10 parts by weight of diethylene glycol
2 parts by weight of isopropyl alcohol
5 parts by weight of urea
1 part by weight of acetylenol EH
C. I. Direct Blue 199 3.5 parts by weight
Water balance
(Magenta)
10 parts by weight of diethylene glycol
2 parts by weight of isopropyl alcohol
5 parts by weight of urea
1 part by weight of acetylenol EH
C. I. Acid Red 289 3 parts by weight
Water balance
(yellow)
10 parts by weight of diethylene glycol
2 parts by weight of isopropyl alcohol
5 parts by weight of urea
1 part by weight of acetylenol EH
C. I. Direct Yellow 86 3 parts by weight
Water balance
[0048]
According to the combination of the black ink and the color ink shown above, the black ink is cationic and the cyan (C), yellow (Y), and magenta (M) inks are anionic. When in contact with or mixed with, both colorants become insoluble or agglomerated. This improves the fixability.
[0049]
As described above, in this embodiment, an image is formed using an ink set in which one of the black ink and the color ink is a cationic ink and the other is an anionic ink.
[0050]
Here, an outline of features in the present invention will be described. The present invention is characterized in that data is adjusted so that ink dots of different colors (first color and second color) overlap each other. Specifically, the data corresponding to the second color is adjusted so that the second ink dot overlaps at the same location where the first color ink dot is recorded. By performing such data adjustment processing, the first color ink dot and the second ink dot overlap. Since the first color ink and the second color ink are inks that react with each other to improve the fixing property, the first color ink and the second color ink are used. Fixing improves the overlap. Therefore, the ink dots of different colors are overlapped.
[0051]
In the present embodiment, black ink is used as the first color ink, and color ink is used as the second color ink. Hereinafter, a recording process performed by the ink jet recording apparatus according to the present embodiment, that is, an adjustment process for overlapping dots will be described with reference to FIGS.
[0052]
FIG. 6 is a diagram showing a recording result when the input image data is in the first data format (A) and in the second data format (B). As will be described later, the first data format (A) is image data representing a density level within a predetermined area by 1 bit, and the second data format (B) is a density level within a predetermined area. This is image data represented by 2 bits.
[0053]
6 will be described in detail. (1) is a schematic diagram showing the resolution (recording resolution) of the recording dots. A- (1) has a resolution of 600 dpi, and one dot is recorded within 1/600 (inch) × 1/600 (inch). B- (1) has a resolution of 1200 dpi, and 4 dots are recorded within 1/600 (inch) × 1/600 (inch). In other words, in B- (1), one dot is recorded within 1/1200 (inch) × 1/1200 (inch). Recording data (density data) is sent from the host in a form corresponding to A- (1) and B- (1). In this embodiment, an area within 1/600 (inch) × 1/600 (inch) is referred to as a predetermined area (one pixel).
[0054]
(2) is a diagram showing a format of recording data transmitted from the host and input to the ink jet recording apparatus. A- (2) is a data format having, as 1-bit information, information relating to whether or not recording dots are recorded in the predetermined area. This is the first data format. This first data format is density data indicating two levels of density levels (density = 0, density = 1). When the recording data is “0” (density = 0), recording dots are placed in a predetermined area. When recording is not performed and recording data is “1” (density = 1), one recording dot is recorded in a predetermined area. B- (2) is a data format having information on the number of recording dots recorded in the predetermined area as 2-bit information. This is the second data format. This second data format is density data indicating four density levels (density = 0, density = 1, density = 2, density = 4), and when the recording data is “00” (density = 0). No recording dot is recorded in the predetermined area. When the recording data is “01” (density = 1), one recording dot is recorded in the predetermined area, and when the recording data is “10” (density = In 2), two recording dots are recorded in a predetermined area. When the recording data is “11” (density = 4), four recording dots are recorded in the predetermined area.
[0055]
(3) is a diagram showing a recording result when recording dots are recorded according to the first data format and the second data format. A- (3) is a recording result when recording is performed in accordance with the recording data of the first data format as shown in A- (2), and in the case of density = 0 and density = 1. Each one produces a recording result. B- (3) is a recording result when recording is performed according to the recording data of the second data format as shown in B- (2), and when density = 0 and density = 4, respectively. When the density is 1, the recording results are four, and when the density is 2, the recording results are six.
[0056]
In the present embodiment, black data is sent in the first data format, and cyan, magenta, and yellow data is sent in the second data format. Therefore, the dot diameters of black ink and color (cyan, magenta, yellow) ink are different. Specifically, the diameter of black ink dots is as shown by A- (3), while the color ink dots are shown as B- (3). Therefore, images such as characters, lines, and tables mainly formed with black dots can be recorded at high speed, and images such as patterns and photographs mainly formed with color dots can be recorded with high resolution.
[0057]
FIG. 7 is a flowchart showing the recording process in the first embodiment. A control program for executing this process is stored in the ROM 213. Then, when the CPU 211 reads out the control program stored in the ROM 213, the processing shown in FIG.
[0058]
The flowchart of FIG. 7 will be described. First, in step S1, it is determined whether or not to perform dot overlap adjustment processing for adjusting data so that black and color dots overlap each other with respect to print data sent from a host computer (PC). If the dot overlap adjustment process is performed, the process proceeds to step S2, and if not, the process proceeds to step S5. The criteria for determining whether or not to perform this dot overlap adjustment process will be described later.
[0059]
In step S2, it is determined whether or not black recording data for a predetermined area on the recording medium is “1”, that is, whether or not black dots are recorded in the predetermined area. If the black recording data is “1”, the process proceeds to step S3. If the black recording data is not “1”, that is, if the data is “0”, the process proceeds to step S5.
[0060]
In step S3, it is determined whether or not the color recording data for the predetermined area is "00". That is, it is determined whether there is a color dot recorded at a position overlapping with the black dot. Here, control is performed so that one or more color dots overlap one black dot. Accordingly, if the color recording data is “00”, the process proceeds to step S4, and the color recording data is changed to “01” in step S4. On the other hand, when the color recording data is not “00”, that is, when the data is “01”, “10”, or “11”, the color dot that overlaps with the black dot already exists, so the data is not changed. In this case, the process proceeds to step S5.
[0061]
When the data is changed to “01” in step S4, the process proceeds to step S5. In step S5, it is determined whether or not the dot overlap adjustment process has been completed for all black dots. If it is determined that the recording control process has been completed, the recording control process is terminated. If it is determined that the recording control process has not been completed, the process proceeds to step S6.
[0062]
In step S6, the black dot that is the target of the dot overlap adjustment process is changed, and the processes in and after step S2 are performed again. After the recording control process shown in FIG. 7 is completed in this way, the recording operation is performed by expanding the recording data into dots. According to this recording control process, color dots are always overlapped at locations where black dots are recorded. This improves the fixability of the recorded ink dots. This is especially effective for images with a lot of black.
[0063]
In the present invention, since the data formats between different colors are different as shown in FIG. 6, it is possible to perform dot overlap adjustment processing only by adjusting density data without developing the dots. In other words, any dot arrangement of B- (3) (density = 1, density = 2, density = 4) always overlaps the dot of A- (3) (density = 1), so bothering the dots It is not necessary to perform the dot overlap adjustment process after the image is developed. If the data format between different colors (X color, Y color) is the same as shown in FIG. 17, it is not known which dot arrangement is selected. Processing cannot be performed. Specifically, when the X color dot with density = 2 and the Y color dot with density = 1 are overlapped, the dot arrangement (5) is selected for the X color, and the dot arrangement (2) is selected for the Y color. Occurs. In this case, the X and Y dots do not overlap. If the dot arrangement (5) is selected for the X color, the dots do not overlap unless the dot arrangement (1) or (4) is selected for the Y color. In this way, if the data format is the same, dots between different colors do not necessarily overlap, so first expand the dots, then determine whether they overlap, and if they do not overlap, Processing to change the arrangement must be performed. If processing is performed after dot development is performed in this manner, the processing time becomes longer than when processing is performed without performing dot development. On the other hand, as described above, in the present invention, the dot overlap adjustment process can be performed by converting the density data before the dot development, so that the process can be simplified and speeded up.
[0064]
Here, the criteria for determining whether or not to perform the dot overlap adjustment process in step S1 will be described. In the present embodiment, it is assumed that the adjustment process is performed when it is determined that there are many high density portions in an image to be recorded. This determination may be made by the user or the recording device.
[0065]
First, a case where the user makes a determination will be described. The user sees the pattern of the pattern to be recorded on the monitor screen of the host computer (PC). When it is determined that the image to be recorded has many high density portions and the amount of ink discharged within a predetermined area is increased, the image is processed in an operation panel (not shown) provided in the ink jet recording apparatus or a host computer. The dot overlap adjustment process is set by the printer driver. When the dot overlap adjustment process is set, a recording process as shown in FIG. 7 is performed.
[0066]
As described above, when the user sets himself / herself, there is an advantage that the above-described processing can be performed according to the user's usage and preference. In this embodiment, color dots are superimposed on black dots, and if the color dots are excessively superimposed, the color of the black dots may not be true black. Some users desire a black image rather than fixing ability. In such a case, the user may not select the above process. On the other hand, when the fixing property is desired, it is sufficient to select to perform the above processing.
[0067]
Next, a case where the recording apparatus automatically determines will be described. A flowchart for this determination processing is shown in FIG. Note that the processing shown in this flowchart is performed by the CPU 212 of the recording apparatus. First, when image data is input to the recording apparatus in step S1, the process proceeds to step S2, and the level of the input image signal (density level) is determined by a predetermined method. In step S2, it is determined whether the level of the signal is high. If it is determined that the signal level is high, that is, the ink discharge amount is increased at a high density, the process proceeds to step S3 to set dot overlap adjustment processing. When the dot overlap adjustment process is set, a recording process as shown in FIG. 7 is performed. On the other hand, if it is determined that the signal level is not so high, the dot overlap adjustment process is not set. In this way, it is determined whether or not to perform dot overlap adjustment processing according to the signal level of the image data.
[0068]
The dot overlap adjustment process is set based on the signal level of all image data before printing is started, and may be set to a format that does not change thereafter. It may be determined from the signal level, and the setting of the dot overlap adjustment process may be changed each time.
[0069]
By performing such control, an image with improved fixability can be formed without the user setting dot overlap adjustment processing based on image data.
[0070]
As described above, according to the first embodiment, it is possible to improve the fixability by superimposing color dots on black dots. In addition, since it is possible to perform dot overlap adjustment processing only by adjusting density data without developing into dots, simplification and speeding up of processing can be realized. Furthermore, images such as characters, lines, and tables mainly formed with black dots can be recorded at high speed, and images such as patterns and photographs mainly formed with color dots can be recorded with high resolution.
[0071]
(Second Embodiment)
In the first embodiment, control is performed so that at least one color dot overlaps one black dot. However, in the second embodiment, two black dots are used. Control is performed so that the above color dots overlap. Since parts other than this feature are the same as those in the first embodiment, description thereof will be omitted.
[0072]
FIG. 9 is a flowchart showing a recording process in the second embodiment, and a control program for executing this process is stored in the ROM 213. Then, when the CPU 211 reads out the control program stored in the ROM 213, the processing shown in FIG.
[0073]
The flowchart of FIG. 9 will be described. First, in step S1, it is determined whether or not to perform dot overlap adjustment processing for adjusting data so that black and color dots overlap each other with respect to print data sent from a host computer (PC). If the dot overlap adjustment process is performed, the process proceeds to step S2, and if not, the process proceeds to step S5. Note that the criterion for determining whether or not to perform this dot overlap adjustment process is as described in the first embodiment.
[0074]
In step S2, it is determined whether or not black recording data for a predetermined area on the recording medium is “1”, that is, whether or not black dots are recorded in the predetermined area. If the black recording data is “1”, the process proceeds to step S3. If the black recording data is not “1”, that is, if the data is “0”, the process proceeds to step S5.
[0075]
In step S3, it is determined whether the color recording data for the predetermined area is either "00" or "01". That is, it is determined whether there are two or more color dots to be recorded at a position overlapping with one black dot. Here, control is performed so that two or more color dots overlap one black dot. Accordingly, if the color recording data is “00” or “01”, the process proceeds to step S4, and the color recording data is changed to “10” or “11” in step S4. On the other hand, if the color recording data is “00” but not “01”, that is, if the data is “10” or “11”, the number of color dots that overlap one black dot is already two or more. The data is not changed. In this case, the process proceeds to step S5.
[0076]
When the data is changed to “10” or “11” in step S4, the process proceeds to step S5. In step S5, it is determined whether or not the dot overlap adjustment process has been completed for all black dots. If it is determined that the recording control process has been completed, the recording control process is terminated. If it is determined that the recording control process has not been completed, the process proceeds to step S6.
[0077]
In step S6, the black dot that is the target of the dot overlap adjustment process is changed, and the processes in and after step S2 are performed again. After the recording control process shown in FIG. 9 is completed in this way, the recording operation is performed by expanding the recording data into dots. According to this recording control process, two or more color dots always overlap each other at a place where one black dot is recorded. This improves the fixability of the recorded ink dots. This is especially effective for images with a lot of black.
[0078]
In step S4, the color data is changed to “10” or “11”. The data to be changed is set in advance according to the properties of the ink used and the ink absorbency of the recording medium. Just keep it. As the number of color dots to be added increases, the amount of ink that is ejected within a predetermined area also increases accordingly, and it is possible that bleeding occurs. However, on the other hand, the water resistance of the image is considered to improve. Therefore, the number of color dots to be added may be set from the viewpoint of bleeding and water resistance.
[0079]
As described above, according to the second embodiment, the fixability can be improved by overlapping the color dots on the black dots. In particular, since two or more color dots are superimposed on one black dot, the water resistance is further improved. In addition, since it is possible to perform dot overlap adjustment processing only by adjusting density data without developing into dots, simplification and speeding up of processing can be realized.
[0080]
(Third embodiment)
In the first embodiment example and the second embodiment example, the number of color dots to be superimposed on one black dot is set in advance. On the other hand, the third embodiment is characterized in that the number of color dots to be superimposed on one black dot can be determined by user selection. That is, the user can determine the image to be recorded and the use thereof, and the recording apparatus can more appropriately meet the user's needs. The user selects a command corresponding to the number of color dots to be overlapped by using an operation panel (not shown) provided in the ink jet recording apparatus or a printer driver to be processed in the host computer, and the above determination is made by selecting the command. Do. Further, the number of color dots to be superimposed may be determined according to the image. According to this, a user's operation becomes easier.
[0081]
(Fourth embodiment)
In the first to third embodiments, control is performed so that at least one color dot is superimposed on one black dot. On the other hand, the fourth embodiment is characterized in that color dots are not necessarily superimposed on black dots. That is, even if it is a black dot, there are those in which color dots do not overlap. Since parts other than this feature are the same as those in the first to third embodiments, description thereof will be omitted.
[0082]
FIG. 10 is a flowchart showing a recording process in the fourth embodiment, and a control program for executing this process is stored in the ROM 213. Then, when the CPU 211 reads out the control program stored in the ROM 213, the processing shown in FIG.
[0083]
The flowchart of FIG. 10 will be described. First, in step S1, it is determined whether or not to perform dot overlap adjustment processing for adjusting data so that black and color dots overlap each other with respect to print data sent from a host computer (PC). If the dot overlap adjustment process is performed, the process proceeds to step S2, and if not, the process proceeds to step S6. Note that the criterion for determining whether or not to perform this dot overlap adjustment process is as described in the first embodiment.
[0084]
In step S2, it is determined whether or not black recording data for a predetermined area on the recording medium is “1”, that is, whether or not black dots are recorded in the predetermined area. If the black recording data is “1”, the process proceeds to step S3. If the black recording data is not “1”, that is, if the data is “0”, the process proceeds to step S6.
[0085]
In step S3, it is determined whether or not a process of superimposing one or more color dots on the black dots is performed. This is determined according to the image data. Specifically, as described in the first embodiment, the determination is made based on the level of the signal level of the image data. That is, the signal level of several pixels around the black dot that is the target of the dot overlap adjustment process is determined, and if the signal level is higher than a preset value, the color for that black dot is determined. Let's superimpose the dots. In this case, the process proceeds to step S4. That the height of the signal level is not less than a preset value indicates that the periphery of the black dot is a high density portion. Therefore, color dots are added to improve the fixability of black dots. On the other hand, if the signal level is lower than the preset value, the process proceeds to step S6.
[0086]
In step S4, it is determined whether or not the color recording data to be superimposed on the black dot that is the target of the dot overlap adjustment process is “00”. That is, it is determined whether there is a color dot recorded at a position overlapping with the black dot. Here, control is performed so that one or more color dots overlap one black dot. Accordingly, if the color recording data is “00”, the process proceeds to step S5, and the color recording data is changed to “01” in step S5. On the other hand, when the color recording data is not “00”, that is, when the data is “01”, “10”, or “11”, the color dot that overlaps the black dot already exists, and thus the data is not changed. In this case, the process proceeds to step S6.
[0087]
When the data is changed to “01” in step S5, the process proceeds to step S6. In step S6, it is determined whether or not steps S2 to S5 have been completed for all black dots. If it is determined that the recording control process has been completed, the recording control process is terminated. If it is determined that the recording control process has not been completed, the process proceeds to step S7.
[0088]
In step S7, the black dot that is the target of the dot overlap adjustment process is changed, and the process from step S2 is performed again. After the recording control process shown in FIG. 10 is completed in this way, the recording operation is performed by expanding the recording data into dots. According to this recording control process, color dots overlap at least a part of the locations where black dots are recorded. This improves the fixability of the recorded ink dots. Thus, by thinning out the color dots to be overlapped with the black dots to some extent, the probability of ink overflow is further reduced.
[0089]
In the above description, it is determined whether or not processing is performed on the black dots to be processed by determining the signal level around the target dots. You may keep it. By doing so, it can be thinned out at a constant rate.
[0090]
In addition, color dots may be superimposed only on some black dots among black dots in a region determined to be a high density portion. That is, the color dots to be superimposed on the black dots forming the high density portion are thinned out. By doing so, it is possible to further reduce the probability of occurrence of ink overflow in the high density portion and to improve the fixability of black dots. As shown in FIG. 11, even if the color dot is overlapped only on the black dot at the center, not only the central black dot but also the surrounding black dots are in contact with the color ink dots because the color dots spread a little. As a result, the fixing property can be improved.
[0091]
(Fifth embodiment)
In the dot overlap adjustment processing of the first to fourth embodiments, the density of color data (hereinafter referred to as target color data) recorded in the same area as the area where the target black dots are recorded. The level was simply going up. On the other hand, in the fifth embodiment, the density level of the data in the vicinity of the target color data is lowered, and the reduced density is added to the target color data to increase the density level of the target color data. It is a feature. That is, the neighboring color data is moved to the target color data.
[0092]
The fifth embodiment will be described below with reference to FIG. FIG. 12 is a flowchart showing the recording process in the fifth embodiment. The processes from step S1 to S3 in FIG. 12 are the same as steps S1 to S3 shown in FIG. Here, step S101 and subsequent steps will be described.
[0093]
In step S101, it is determined whether color data having a density level of 2 or more exists in the vicinity of the target color data. That is, it is determined whether or not there is a portion in which two or more color dots are recorded in a nearby region. Note that the vicinity means an area (d2 to d9) adjacent to the target dot (d1) as shown in FIG.
[0094]
If it is determined that there is color data having a density level of 2 or more, the process proceeds to step S102. On the other hand, if it is determined that there is no color data having a density level of 2 or more, the process proceeds to step S5.
[0095]
In step S102, the density level of one color data among the color data having a density level of 2 or more is lowered. Then, the reduced density is added to the target color data. Specifically, if the neighboring color data is “10”, it is changed to “01”, and instead, the target color data is changed from “00” to “01”. Similarly, when the color data is “11”, it is changed to “10”, and the target color data is changed to “01”. When such data change processing is completed, the process proceeds to step S5. Since step S5 and subsequent steps are the same as those in the first embodiment, description thereof is omitted.
[0096]
Hereinafter, the processes in steps S101 and S102 will be described more specifically with reference to FIG. FIG. 13 is a diagram showing that the neighboring color data is moved to the target color data.
[0097]
FIG. 13A shows black recording data to be processed. When the dot overlap adjustment process is performed on the black dots, the target color data (d1) shown in FIG. 13B and the recording data (d2 to d9) in the vicinity thereof are determined. In (b), since the data of d1 is “00” and there are data (d2 and d9) having a density of 2 or more in the vicinity thereof, the data of d1 is changed from “00” to “01”. The data is changed from “10” to “01”. That is, the density of d1 is changed from 0 to 1, and the density of d2 is changed from 2 to 1. Of course, instead of d2, d9 data may be changed from “11” to “10”, and d1 data may be changed from “00” to “10”. FIG. 13C shows print data after such data change processing, that is, print data after dot overlap adjustment processing.
[0098]
In the above description, recording data having a density level of 2 or more is the object to be changed, but recording data having a density level of 1 may be the object to be changed.
[0099]
There is also a method of moving data (changing density) little by little from a plurality of recording data. For example, the density levels of d2 and d7 are lowered by one step, and the density level of d1 is raised by two steps accordingly. That is, d2 data is changed to “01”, d7 data is changed to “00”, and d1 data is changed to “10”.
[0100]
As described above, according to the present embodiment, since dot overlap adjustment is performed by moving the target color data instead of increasing it, there is no change in the density of the entire image, and the image data is faithfully recorded. Is possible. Furthermore, the present embodiment also provides the effects of the first embodiment described above.
[0101]
(Sixth embodiment)
In the first to fifth embodiments, the nozzle diameter of the black head and the nozzle diameter of the color head are different as shown in FIG. 5, but in the sixth embodiment, FIG. As shown, nozzles having the same nozzle diameter are used. In the present embodiment, the black dot diameter is controlled to be different from the black ink discharge amount so that the black dot diameter is approximately twice the color dot diameter. Since the features other than this characteristic are the same as those in the first to fifth embodiments, description thereof will be omitted. That is, the control of the dot overlap adjustment process is executed according to any one of the flowcharts shown in FIGS. 7, 9, 10, and 12.
[0102]
FIG. 15 is a schematic cross-sectional view showing the structure of the ink jet head used in the sixth embodiment. As shown in FIG. 15, two heaters SH1 and SH2 are disposed in each ink path 152A. These two heaters have different surface areas, and each heater can be driven independently and electrode wiring or the like (not shown) can be driven simultaneously. Is provided. Note that the heater SH1 and the heater SH2 have the same length in the longitudinal direction of the ink path 152A, and have different surface areas by making their widths different. A discharge port 152N is opened at the tip of the ink path 152A.
[0103]
The structure of each ink path unit composed of the heater, discharge port, ink path and the like described above is arranged in a predetermined number at a density of 720 DPI in the ink jet head, and in the present embodiment, the discharge in each unit is arranged. The opening area of the outlet and the heater area are the same among the ink path units.
[0104]
When two heaters are used, it is basically possible to change the discharge amount in three stages for each discharge port according to the combination of heaters to be driven. That is, there are basically three discharge amount modes of small, medium and large by switching the heater to be driven. In the small discharge amount mode, only the heater SH1 is driven to discharge a droplet having a volume of Xpl. In the discharge amount mode, only the heater SH2 is driven to discharge Y (Y> X) pl droplets, and in the large discharge amount mode, the heaters SH1 and SH2 are simultaneously driven to discharge Zpl (= X + Ypl) droplets.
[0105]
As described above, if the head shown in FIG. 15 is used, the discharge amount can be changed in three steps. In this embodiment, two modes, a large discharge amount mode and a small discharge amount mode, are used. That is, the large discharge amount mode is set when discharging black ink, and the small discharge amount mode is set when discharging color ink. In this way, the black ink discharge amount and the color ink discharge amount are made different so that the black dot diameter is controlled to be about twice that of the color dots. Specifically, the ejection amount (X and Y) is adjusted so that the black dot diameter is about twice that of the color dots when the ink lands on the recording medium.
[0106]
In FIG. 15, the nozzle pitch of the black head and the color head is the same, but the nozzle pitch of the black head may be twice the nozzle pitch of the color head. This is because the black dot diameter is twice the color dot diameter, and the data format differs between black and color as shown in FIG.
[0107]
(Seventh embodiment)
In the first to sixth embodiment examples, one of the black ink and the color ink is made cationic and the other is made anionic. In contrast, in the seventh embodiment, the color ink has a high penetration speed into the recording medium, and the black ink has a relatively low penetration speed into the recording medium as compared with the color ink. It is characterized by using. Since the features other than this characteristic are the same as those in the first to sixth embodiments, description thereof will be omitted. That is, the control of the dot overlap adjustment process is executed according to any one of the flowcharts shown in FIGS. 7, 9, 10, and 12.
[0108]
The components of the ink used in this embodiment are as follows.
(Yellow)
C. I. Direct Yellow 86 3 parts
10 parts of diethylene glycol
Isopropyl alcohol 2 parts
Urea 5 parts
1 part of acetylene EH (Kawaken Chemical)
Water balance
(Magenta)
C. I. Acid Red 289 3 parts
10 parts of diethylene glycol
Isopropyl alcohol 2 parts
Urea 5 parts
1 part of acetylene EH (Kawaken Chemical)
Water balance
(cyan)
C. I. Direct Bull-199 3 parts
10 parts of diethylene glycol
Isopropyl alcohol 2 parts
Urea 5 parts
1 part of acetylene EH (Kawaken Chemical)
Water balance
(black)
C. I. Direct black 154 3 parts
10 parts of diethylene glycol
Isopropyl alcohol 2 parts
Urea 5 parts
Water balance
[0109]
Thus, CMY improves permeability by adding 1% acetylenol EH to Bk. In addition to this, there are other surfactants, alcohols, and the like.
[0110]
According to the present embodiment, since the color ink having a high penetration speed (fast fixing property) adheres to the recording paper as the base of the black ink having a relatively low penetration speed (slow fixing ability), the recording paper is used. The surface has good wettability, that is, the formation of an interface with good permeability has accelerated the fixability of the next black ink and prevented the black ink and the color ink from bleeding. A high-quality color image can be obtained.
[0111]
(Other embodiments)
The ink used in the present invention is not limited to the cationic / anionic ink and the low-permeability / high-permeability ink as described above, and the first color ink and the second color ink. Any material that interacts with the ink to improve the fixing property may be used.
[0112]
Further, the shape of the head that can be used in the present invention is not limited to the recording head in which the nozzles are linearly arranged as shown in FIG. 5 and FIG. 14, but the nozzles as shown in FIG. The recording heads may be arranged in a staggered pattern. Further, as shown in FIG. 16B, a structure in which color heads (C, M, and Y) are arranged vertically may be used.
[0113]
In the first to seventh embodiments, the black ink and the color ink that interact with each other to improve the fixing property are used, and the black ink and the color ink are superimposed. However, in the present invention, the properties of the color inks may be made different, and the color inks having different colors may be overlapped. In other words, in the first embodiment, the first color ink is black and the second color ink is color. For example, the first color ink is cyan and the second color ink is the second color ink. May be a color other than cyan, the first color ink may be yellow, and the second color ink may be a color other than yellow.
[0114]
The recording head is not limited to a system that ejects ink using an electrothermal transducer. For example, a piezo type that discharges a liquid by causing a current to flow through the piezoelectric element, or an electrostatic suction type that applies high voltage, etc. A head can be used.
[0115]
In the embodiment of the present invention, a storage medium in which a program code of software that realizes the functions of the above-described embodiments is recorded is supplied to a system or apparatus, and a computer (or CPU or MPU) of the system or apparatus stores the storage medium Needless to say, this can also be achieved by reading and executing the program code stored in the.
[0116]
In this case, the program code itself read from the storage medium realizes the functions of the above-described embodiments, so that the storage medium storing the program code constitutes the present invention.
[0117]
As a storage medium for supplying the program code, for example, a floppy disk, a hard disk, an optical disk, a magneto-optical disk, a CD-ROM, a CD-R, a magnetic tape, a nonvolatile memory card, a ROM, or the like can be used.
[0118]
Further, by executing the program code read by the computer, not only the functions of the above-described embodiments are realized, but also an OS (operating system) running on the computer based on the instruction of the program code However, it is needless to say that some or all of the actual processing is performed and the functions of the above-described embodiments are realized by the processing.
[0119]
Further, after the program code read from the storage medium is written in a memory provided in a function expansion board inserted into the computer or a function expansion unit connected to the computer, the function expansion board is based on the instruction of the program code. Needless to say, the CPU of the function expansion unit or the like performs part or all of the actual processing and the functions of the above-described embodiments are realized by the processing.
[0120]
The present invention provides an excellent effect particularly in a recording apparatus using an ink jet recording head that performs recording by forming flying droplets using thermal energy among ink jet recording methods.
[0121]
As its typical configuration and principle, for example, those performed using the basic principle disclosed in US Pat. Nos. 4,723,129 and 4,740,796 are preferable. This method can be applied to both the so-called on-demand type and continuous type. In particular, in the case of the on-demand type, it is arranged corresponding to the sheet or liquid path holding the liquid (ink). By applying at least one drive signal corresponding to the recording information and giving a rapid temperature rise exceeding nucleate boiling to the electrothermal transducer, the thermal energy is generated in the electrothermal transducer, and the recording head This is effective because film boiling occurs on the heat acting surface, and as a result, bubbles in the liquid (ink) corresponding to the drive signal can be formed. By the growth and contraction of the bubbles, liquid (ink) is ejected through the ejection opening to form at least one droplet. It is more preferable that the drive signal has a pulse shape, since the bubble growth and contraction is performed immediately and appropriately, and thus it is possible to achieve discharge of a liquid (ink) having particularly excellent responsiveness.
[0122]
As this pulse-shaped drive signal, those described in US Pat. Nos. 4,463,359 and 4,345,262 are suitable. Further excellent recording can be performed by employing the conditions described in US Pat. No. 4,313,124 of the invention relating to the temperature rise rate of the heat acting surface.
[0123]
As the configuration of the recording head, in addition to the combination configuration (straight liquid channel or right-angle liquid channel) of the discharge port, the liquid channel, and the electrothermal transducer as disclosed in each of the above-mentioned specifications, the thermal action US Pat. No. 4,558,333 and US Pat. No. 4,459,600, which disclose a configuration in which the portion is arranged in a bent region, may be used.
[0124]
In addition, for a plurality of electrothermal transducers, Japanese Patent Application Laid-Open No. Sho 59-123670 that discloses a configuration in which a common slit is used as a discharge portion of the electrothermal transducer or an aperture that absorbs pressure waves of thermal energy is provided. A configuration based on Japanese Patent Application Laid-Open No. 59-138461 disclosing a configuration corresponding to the discharge unit may be adopted.
[0125]
Furthermore, as a full-line type inkjet head having a length corresponding to the width of the maximum recording medium that can be recorded by the recording apparatus, the length is satisfied by a combination of a plurality of recording heads as disclosed in the above specification. Either a configuration or a configuration as a single recording head formed integrally may be used.
[0126]
Furthermore, even with the serial type as in the above example, it is possible to make electrical connection with the device body and supply ink from the device body by attaching it to the recording head fixed to the device body or the device body. A replaceable chip type recording head or a cartridge type recording head in which an ink tank is integrally provided in the recording head itself may be used.
[0127]
In addition, it is preferable to add a recording head ejection recovery means, a 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. Specifically, heating is performed using a capping unit, a cleaning unit, a pressurizing or suction unit, an electrothermal transducer, a heating element different from this, or a combination thereof. Examples thereof include a preliminary heating unit for performing the discharge and a preliminary discharge unit for performing discharge different from the recording.
[0128]
Further, regarding the types or number of the recording heads to be mounted, two or more numbers may be provided corresponding to a plurality of inks having different recording colors and densities. That is, for example, as a recording mode of the recording apparatus, not only a recording mode of only a mainstream color such as black, but also a recording head may be configured integrally or by a combination of a plurality of different colors, The present invention is also effective for an apparatus having at least one of full-color recording modes by color mixing.
[0129]
In addition, in the above-described embodiments of the present invention, the ink is described as a liquid. However, ink that is solidified at room temperature or lower and that softens or liquefies at room temperature may be used. Alternatively, in the ink jet method, the temperature of the ink itself is generally adjusted within a range of 30 ° C. or higher and 70 ° C. or lower to control the temperature so that the viscosity of the ink is within the stable discharge range. An ink in liquid form may be used.
[0130]
In addition, it is solidified and heated in an untreated state in order to actively prevent the temperature rise caused by thermal energy from being used as the energy for changing the state of the ink from the solid state to the liquid state, or to prevent the ink from evaporating. You may use the ink which liquefies by. In any case, by applying heat energy according to the recording signal of thermal energy, the ink is liquefied and liquid ink is ejected, or when it reaches the recording medium, it starts to solidify. The present invention can also be applied to the case where ink having a property of being liquefied for the first time is used. The ink in such a case is in a state of being held as a liquid or a solid in a porous sheet recess or through-hole as described in JP-A-54-56847 or JP-A-60-71260. Alternatively, the electrothermal converter may be opposed to the electrothermal converter. In the present invention, the most effective one for each of the above-described inks is to execute the above-described film boiling method.
[0131]
【The invention's effect】
As described above, according to the present invention, the dot overlap adjustment process for overlapping the first color ink dots and the second color ink dots can be executed without performing dot expansion. And high speed. Further, the fixability can be improved by overlapping the first color ink dots and the second color ink dots.
[Brief description of the drawings]
FIG. 1 is a perspective view illustrating a configuration of main parts of a recording apparatus according to an embodiment of the present invention.
FIG. 2 is a block diagram illustrating a configuration of a control circuit of a recording apparatus according to an exemplary embodiment of the present invention.
FIG. 3 is a view showing the structure of an ink jet head used in the recording apparatus of the present invention.
FIG. 4 is a diagram for explaining a method of controlling the amount of ink discharged by changing the power applied to the heater.
FIG. 5 is a diagram illustrating an arrangement of nozzles in the recording head.
FIG. 6 is a diagram illustrating a recording result when input image data is in a first data format (A) and in a second data format (B).
FIG. 7 is a flowchart showing a recording process in the first embodiment.
FIG. 8 is a flowchart showing determination processing when the recording apparatus automatically determines whether or not to perform dot overlap adjustment processing.
FIG. 9 is a flowchart showing a recording process in the second embodiment.
FIG. 10 is a flowchart showing a recording process in the fourth embodiment.
FIG. 11 is a diagram showing that color dots are superimposed only on a black dot at the center.
FIG. 12 is a flowchart showing recording processing in a fifth embodiment.
FIG. 13 is a diagram showing that neighboring color data is moved to target color data.
FIG. 14 is a diagram showing a nozzle arrangement of a recording head used in a sixth embodiment.
FIG. 15 is a schematic cross-sectional view showing the structure of an inkjet head used in a sixth embodiment.
FIG. 16 is a diagram showing an example of the form of a head that can be used in the present invention.
FIG. 17 is a diagram illustrating a recording result when the data format between different colors (X color, Y color) is the same.
[Explanation of symbols]
1 Ink cartridge
2 Carriage
3 Carriage motor
4 Cable
5 Platen
6 LF motor
7 Recovery mechanism
8 Recording head
9 Recording media
102 Heater
104 Heater board
106 Top plate
108 Discharge port
110 liquid channel
112 Bulkhead
114 Ink chamber
116 Ink supply path
211 Interface circuit
212 CPU
213 ROM
214 RAM
215 EEPROM
216 Input control circuit
217 Key
218 Output control circuit
219 LED
220 Printhead drive circuit
221 LF motor drive circuit
222 CR motor drive circuit

Claims (19)

The same unit of the second color ink on the recording medium improves the fixing property of the first color ink to the recording medium by contacting the first color ink and the first color ink. An ink jet recording method for recording an image by contacting at least a part in an area,
Inputting first density data corresponding to the first color ink and a plurality of bits of second density data corresponding to the second color ink;
A first ejection step of ejecting the first color ink from a recording head to a plurality of unit regions corresponding to the input first density data;
Whether to increase the density level of the input second density data corresponding to the unit area for at least a part of the plurality of unit areas from which the first color ink is ejected. A process of determining whether or not
When it is decided to perform the process of increasing the density level, the density level of the second density data is increased in order to bring the first color ink and the second color ink into contact in the unit area. A process of performing processing;
Generating dot data for ejecting the ink of the second color based on the second density data subjected to the process of increasing the density level;
A second ejection step of ejecting the second color ink from the recording head to at least a part of the plurality of unit areas based on the generated dot data;
The first color ink discharged in the first discharge step and the second color ink discharged in the second discharge step are the dot diameter X of the first color ink and the second color ink. An ink jet recording method comprising: contacting in the same unit region so as to satisfy a relationship of X> Y with a dot diameter Y of the ink of the color of The same unit of the second color ink on the recording medium improves the fixing property of the first color ink to the recording medium by contacting the first color ink and the first color ink. An inkjet recording apparatus that records an image by contacting at least part of the area,
Means for inputting first density data corresponding to the first color ink and a plurality of bits of second density data corresponding to the second color ink;
First control means for controlling the plurality of unit areas corresponding to the input first density data to discharge the first color ink from a recording head;
Decide whether or not to increase the density level of the second density data corresponding to the unit area for at least a part of the plurality of unit areas from which the ink of the first color is ejected. Means to
When it is determined to perform the process of increasing the density level, the density level of the second density data is increased so that the first color ink and the second color ink are in contact with each other in the unit area. Means for processing,
Means for generating dot data for ejecting the ink of the second color based on the second density data subjected to the process of increasing the density level;
And a second control unit configured to control the ink of the second color to be ejected from the recording head to at least a part of the plurality of unit regions based on the generated dot data. And
The first color ink ejected by the first control means and the second color ink ejected by the second control means are the dot diameter X of the first color ink and the second color ink. An ink jet recording apparatus, wherein the ink is in contact with each other in the same unit region so as to satisfy a relationship of X> Y with the dot diameter Y of the ink of the color of the ink. A second color ink that improves the fixing property of the first color ink to the recording medium by contacting at least the first color ink and the first color ink is ejected from the recording head. An inkjet recording apparatus for recording an image on a recording medium,
For at least some of the pixels of the plurality of pixels recorded-out based on the first color density data, or a second color density data represented by a plurality of bits corresponding to the pixel is present A determination means for determining whether or not,
If more the second color density data to said determining means determines that there is no order overlap the first color ink dots and ink dots of the second color in the pixel, the second color Density data changing means for performing processing to increase the density level of density data;
On the basis of the concentration the second color density data by that process has been performed the data changing means comprises means for generating the dot data of a second color,
Based on said first color density data, and means for generating a dot data of a first color,
First the first second of said second color ink dot to be recorded based on the color of the dot data the generated color ink dots recorded on the basis of the color of the dot data the generated is overlap with the pixel, and the ink jet recording apparatus diameter of the first ink dots, wherein not greater than the diameter of the diameter of the second ink dots. The first color ink is a black ink;
4. The ink jet recording apparatus according to claim 2, wherein the second color ink is a color ink.   The inkjet recording apparatus according to claim 4, wherein the color ink includes a component that aggregates the color material in the black ink. At least the first color ink and the first color ink are brought into contact with the first color ink to improve the fixing property of the first color ink to the recording medium on the recording medium. An inkjet recording method for recording an image,
Determining, for a pixel recorded based on the density data of the first color, whether the density level of the density data of the second color represented by a plurality of bits corresponding to the pixel is equal to or higher than a predetermined level;
Performing a process of increasing the density level of the second color density data when it is determined that the density level of the density data of the second color is not equal to or higher than a predetermined level;
Generating dot data of the second color based on the density data of the second color subjected to the processing;
Generating dot data of the first color based on the density data of the first color,
The first color ink dots recorded based on the generated first color dot data and the second color ink dots recorded based on the generated second color dot data are: The diameter of the first ink dot is larger than the diameter of the second ink dot.
Wherein when the second color density level of the density data represented by a plurality of bits is determined to be above a predetermined level, increasing the concentration level of the second color density data represented by the plurality of bits processed An ink jet recording method characterized by not performing the above. The ink of the second color that improves the fixability of the ink of the first color to the recording medium by contacting at least the ink of the first color and the ink of the first color is ejected from the recording head. An inkjet recording method for recording an image on a recording medium,
For at least some of the pixels of the plurality of pixels recorded-out based on the first color density data, whether the second color density data represented by a plurality of bits corresponding to the pixel is present A determination process for determining whether or not
If the density data of said second color in said determining step it is determined that there is no concentration of the second color to overlap the first color ink dots and ink dots of the second color in the pixel A density data changing step for performing processing to increase the density level of the data;
The process is based on the second color density data is performed, and generating dot data of a second color,
Based on said first color density data, and a step of generating dot data of a first color,
First the first second of said second color ink dot to be recorded based on the color of the dot data the generated color ink dots recorded on the basis of the color of the dot data the generated is overlap in the same pixel, and an ink jet recording method diameter of the first ink dots, characterized in that characterized in that not larger than the diameter of the diameter of the second ink dots. The relationship between the ink dot diameters satisfies the following relationship: ink dot diameter X of the first color: ink dot diameter Y of the second color Y = N: 1 (N is a natural number of 2 or more). The ink jet recording method according to claim 7 . According to claim 7 or 8, characterized in that different nozzle pitch in the recording head for ejecting the second color ink and the nozzle pitch in the recording head for ejecting the ink of said first color Inkjet recording method.   The relationship between the nozzle pitches is as follows: nozzle pitch in the recording head for ejecting the first color ink: nozzle pitch in the recording head for ejecting the second color ink = N: 1 (N is 2) The inkjet recording method according to claim 9, wherein the relationship of (natural number) is satisfied. Any of claims 7 to 10, characterized in that different nozzle diameter in the recording head for ejecting the second color ink and the nozzle diameter in the recording head for ejecting the ink of said first color An ink jet recording method according to claim 1.   The relationship between the nozzle diameters is as follows: nozzle diameter in the recording head for ejecting the first color ink: nozzle diameter in the recording head for ejecting the second color ink = N: 1 (N is 2) The inkjet recording method according to claim 11, wherein the relationship of (natural number) is satisfied. The first recorded image by the color of the ink dots are relatively low resolution, a recording image by the second color ink dots of claims 7 to 12 characterized in that it is a relatively high resolution The inkjet recording method according to any one of the above. 14. The ink jet recording method according to claim 1, wherein the first color ink is a black ink, and the second color ink is a color ink.   15. The ink jet recording method according to claim 14, wherein the color ink is at least one selected from cyan ink, magenta ink, and yellow ink.   16. The ink jet recording method according to claim 14, wherein the black ink is anionic and the color ink is cationic.   16. The ink jet recording method according to claim 14, wherein the black ink is cationic and the color ink is anionic. Wherein the density data changing step, lowering said second color density level of the density data of the second color corresponding to pixels located near the pixel to be subjected to the process of increasing the density level of the density data, 14. The ink jet recording method according to claim 7 , wherein the density level of the density data of the second color corresponding to the pixel to be processed is increased by the lowered density level.   The inkjet recording method according to claim 14, wherein the color ink includes a component that aggregates the color material in the black ink.

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