JP2000225720A - Ink jet printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ink jet printer which controls inks such that inks of colors are uniformly reduced in the printing using inks of full colors including a black ink. SOLUTION: A three-color minimum residual quantity detecting circuit 29 of a head control section takes residual quantity data Min for a minimum value from residual quantity information of color inks Y, M, C inputted from an ink residual quantity detecting circuit and outputs it to a black/color comparing circuit 30. The black/color comparing circuit 30 compares residual quantity information of a black ink K inputted from the ink residual quantity detecting circuit with the residual quantity data Min. When the residual quantity of the black ink is lower than the other, the compared information is outputted to a judging operation circuit 31. The judging operation circuit 31 outputs information about a using quantity of each color to a printing control circuit based on the compared information so that a part of or all of printing data for the black ink is printed by a synthetic color (process black) formed by inks of three colors.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet printing apparatus for controlling color inks so as to reduce the amount of ink of each color as uniformly as possible.

[0002]

2. Description of the Related Art In recent years, ink-jet printers (ink-jet printing apparatuses) have been widely used. The ink jet printers include a thermal jet method in which ink droplets are ejected by the force of air bubbles and a piezo method in which ink droplets are ejected by deformation of a piezoresistive element (piezoelectric element).

[0003] In these methods, a process in which ink as a color material is formed into ink droplets and directly ejected toward recording paper requires a lower printing energy as compared with an electrophotographic system using a toner as a powdery printing material. Low noise, no need for special fixing process, small print dots, high image quality, and the amount of ink used for printing is free of waste such as thermal transfer ink ribbon. Therefore, the printing method is considered to be excellent in cost performance, and is a printing method widely used especially as a personal printer.

This ink jet printer also has the advantage that it is easy to make a printed image full color by mixing ink. Normally, in full-color printing, black (K) used for black portions of characters and images is added to the three primary colors of subtractive color mixing, yellow (Y), magenta (M), and cyan (C), for a total of 4 colors. Requires color ink. Therefore, at least four types of ink must be provided in the print head.

[0005] These four types of ink are usually contained in a four-part ink chamber of a container called an ink cartridge, and the ink cartridge is provided to a user. As described above, the reason that the ink cartridge is not replaced as an independent single-color ink cartridge divided for each color so that it can be replaced for each color of ink is that the overall size of a personal printer is more than anything else, This is because the highest priority is to avoid troublesome replacement of such consumables.

That is, four ink cartridges are contained in one ink cartridge.
The type in which the ink chambers of the different types are integrally disposed not only can reduce the volume of the entire ink cartridge, but also can replace four types of ink by replacing the ink cartridge once, thereby saving labor. This is because the configuration can be said to be most in line with the user's request.

[0007]

By the way, print data of a color printer using these four types of inks basically focuses on color printing such as graphics, for example. appear. The consumption of the color ink and the black ink is not so much different if the print outputs are mixed appropriately.

[0008] However, printers have been frequently used not only for color images but also for printing texts (text printing). Since text is most easily viewed in black, text printing is likely to be mainly monochrome printing. Therefore, in this case, the consumption of black ink increases. Then the black ink runs out of ink first,
The ink cartridge must be replaced. In other words, despite the large amount of color ink still remaining,
Those still remaining color inks must be discarded by replacing the ink cartridge.

As described above, if the waste of the ink occurs, the advantage of providing the four-color integrated ink cartridge having the shape most suited to the strong demand of the user is reduced by half.
An object of the present invention is to provide an ink jet printing apparatus that controls so that the ink of each color is reduced as uniformly as possible when using an ink cartridge of each color including black, in view of the above-described conventional circumstances. is there.

[0010]

The construction of the ink jet printing apparatus according to the present invention will be described below. First, the ink jet printing apparatus according to the first aspect of the present invention includes an ink storage unit for storing each of yellow, magenta, cyan, and black inks, and discharges ink toward a sheet from discharge nozzles provided for each color. An ink-jet printing apparatus that performs printing by means of a storage unit that stores print data,
Detecting means for detecting the remaining amounts of the yellow, magenta, cyan and black inks prior to the printing operation, and comparing the remaining amounts of the yellow, magenta, cyan and black inks detected by the detecting means with black A comparison unit that outputs a comparison signal when the remaining amount of ink is the smallest, and black print data among the print data stored in the storage unit based on the comparison signal output by the comparison unit is yellow,
Print control means for printing using each of magenta and cyan inks.

Next, the ink jet printing apparatus according to the second aspect of the present invention includes an ink storage section for storing each of yellow, magenta, cyan, and black inks. An ink jet printing apparatus that performs printing by discharging ink, comprising: a storage unit for storing print data; and a print data amount of each color of the print data stored in the storage unit, which is converted into an ink usage amount for each color. Conversion means for obtaining a conversion value for each, detection means for detecting the remaining amount of each of the yellow, magenta, cyan and black inks prior to the printing operation, and each of the colors yellow, magenta, cyan and black detected by the detection means The values obtained by subtracting the amount of ink used by the conversion value means from the remaining amount of ink were compared with each other, and the converted value of black ink was subtracted from the remaining amount of black ink. A comparison means for outputting a comparison signal when the number of prints is smallest, and black printing data among the printing data stored in the storage means based on the comparison signal output by the comparison means, for each of yellow, magenta and cyan inks. And print control means for performing printing using the.

The print control means prints only a predetermined percentage of the black print data using the yellow, magenta, and cyan inks, for example. In addition, for example, only the image data of the black print data is printed using yellow, magenta, and cyan inks.

[0013] Thus, at least the difference between the consumption amounts of the black ink and the color ink can be absorbed, and the black ink and the color ink can be set in substantially the same consumption state.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1A is a perspective view schematically showing a configuration of an ink jet printing apparatus (hereinafter, simply referred to as a printer) according to an embodiment, and FIG.
(A) is an enlarged view of the print head shown in FIG. (A) from the paper side (enlarged view in the direction of arrow A in FIG. (A)), and (c) is an ink cartridge shown in FIG. FIG. 2 is an enlarged cross-sectional view (an enlarged cross-sectional view of FIG.

A printer 1 shown in FIG. 1A is a small printer used at home for personal use. A print head 3 for executing printing and an ink cartridge 4 containing ink are mounted on a carriage 2. Have been. The carriage 2 is slidably supported on one side by a guide rail 5 and is fixed to a toothed drive belt 6 on the other hand.

As a result, the print head 3 and the ink tank 4 are reciprocated in the width direction of the apparatus main body (printer 1) indicated by the double-headed arrow C in the drawing, that is, in the main scanning direction of the print image. A flexible communication cable 7 is connected between the print head 3 and a control device (to be described later) of the apparatus main body, and print data and control signals are sent from the control device to the print head 3 via the flexible communication cable 7.

The print head 3 may be a piezo-type ink jet head that uses an electromechanical transducer such as a piezo element to generate pressure due to mechanical deformation of the ink chamber to eject ink droplets from minute nozzles.
A thermal ink jet head may be used in which an electric pulse is applied to a heating element arranged in a fine ink chamber to heat and foam the ink at a high speed, and ink droplets are ejected from minute nozzles using the growth power of bubbles.

The printer 1 has a configuration in which the print head 3 is integrally formed as a head unit together with the ink cartridge 4 from the beginning and is detachably fixed to the carriage 2, or the print head 3 is fixed to the carriage 2,
An ink cartridge 4 is detachably engaged with the print head 3 and integrated therewith.

Then, as shown in FIG. 1C (shown by a broken line in FIG. 1A), yellow (Y), magenta (M), and cyan (C) ) And black (K) ink, respectively, in four ink chambers 4b (4b-1, 4b-2, 4b-3, 4b-).
4), and the above four inks (four colors) are supplied to the print head 3 from these four ink chambers 4b.

A platen 9 is provided at the lower end of the frame 8 of the apparatus main body so as to face the print head 3 and extend in the reciprocating direction of the print head 3 indicated by a double-headed arrow C in the drawing. . In contact with the platen 9, the paper 10 is fed by a pair of paper feed rollers 11 (the lower roller is shaded by the paper 10 and cannot be seen in the drawing) and a pair of paper ejection rollers 12 (the lower roller is similarly shaded ), The sheet is intermittently conveyed in the printing sub-scanning direction (obliquely lower left direction in the figure) indicated by the arrow D in the figure.

As a result, the print head 3 moves intermittently in the sub-scanning direction relative to the paper 10. During the intermittent movement (intermittent transport of the paper 10), the print head 3
Is driven by the motor 13 via the toothed drive belt 6 and the carriage 2 to eject ink near the paper 10 and print on the paper. Printing can be performed on the entire surface of the paper 10 by repeating the intermittent conveyance of the paper 10 and the printing during the reciprocating movement by the print head 3.

As shown in FIG. 2B, the print head 3 has four types of yellow (Y), magenta (M), cyan (C) and black (K) on its ink ejection surface. Four nozzle rows 14 (14y, 14m, 14
c, 14k) are formed.

In one nozzle row 14, about 128 or 256 nozzles 15 are arranged in one vertical line at a density of, for example, 300 dpi (dots / inch). From each ink chamber 4b of the ink cartridge 4 corresponding to each nozzle row 14 on a one-to-one basis, each nozzle row 14
Are supplied.

FIG. 2 is a block diagram showing a system configuration of the printer having the above configuration. As shown in the figure, the system configuration of the printer 1 is divided into a stationary unit 17 and a moving unit 18. One moving unit 18 drives the print head 3 supported by the guide rail 5 and driven by the motor 13 via the toothed drive belt 6 to reciprocate in the main scanning direction, and heat generation of the heating element of the print head 3. It consists of a driver 19.

The other stationary unit 17 is a control unit, and includes an MPU (micro processing unit) 20 and this MP
An I / F (interface) 22 and a head control unit 23 connected to the U 20 via a bus 21;
Memory A24 and head controller 23 connected to F22
Is connected to the memory B25.

The printer 1 has a host device P
Print data and control data are input from a C (personal computer) 26 via the I / F 22. MPU
Reference numeral 20 receives the print data and control data while controlling the memory A24 via the I / F 22.

An output 27 of a sensor for monitoring each unit is input to the MPU 20, and a drive for controlling the driving of the motor for transporting the paper and the motor 13 for reciprocating the print head 3 from the MPU 20. A signal 28 is output. The MPU 20 drives and controls each unit while referring to the output 27 of the sensor or checking the remaining amount level of each ink in the ink cartridge 4 by an ink remaining amount detection circuit (not shown).

Under the control of the MPU 20, the head control unit 23 develops print data for each line in the memory B25, and based on the developed print data, the driver 19
The print drive of is controlled. Also, it controls an area on a sheet on which the operation is performed. Further, the head controller 23 determines the print ejection amount or print frequency of each ink based on the remaining amount of each ink input from the MPU 20 as described later in detail, and converts the print data for each line. expand.

The head controller 23 sends a driver 19
The transfer of print data and control signals to the printer is performed via the flexible communication cable 7 shown in FIG. Of course,
IrDA may be used.

The present invention is not limited to the printer of the so-called carriage moving type as described above, but is applicable to a line printer having a print head having a full width in the main scanning direction and fixing only the print head and moving only paper. Of course, it can be applied to

FIG. 3 is a block diagram of a main circuit for controlling the type of ink used in the print head 3 according to the amount of ink remaining in the head control unit 23. The head control unit 23 shown in FIG. 2 includes a three-color minimum remaining amount detection circuit 29, a black / color comparison circuit 30, and a determination processing circuit 31, as shown in FIG. The remaining amount information of the color inks Y, M, and C is input to the three-color minimum remaining amount detection circuit 29 of the head control unit 23 from the above-described remaining ink amount detection circuit via the MPU 20 as shown on the left side of FIG. Is done. Similarly, the remaining amount information of the black ink K is input to the black / color comparison circuit 30.

The above-described ink remaining amount detection includes a method of physically detecting the amount of ink using an optical sensor, a method of directly detecting the amount of remaining ink such as electrically detecting a change in inductance by a magnetic circuit, and a method of detecting print dots. A method of indirectly detecting a value obtained by counting the number and converting the value into the used ink amount from the initial ink amount can be used. In any case, the specific method is not directly related to the requirements of the present invention.

The above-described three color minimum remaining amount detection circuit 29 is a circuit for extracting the minimum remaining amount data from the cyan ink C, the magenta ink M, and the yellow ink Y. Min is output to the black / color comparison circuit 30.

The black / color comparison circuit 30 calculates remaining amount information Mi of the black ink K input from the ink remaining amount detecting circuit.
n is a circuit for comparing the remaining amount of the black ink K with the color ink C, M, or the minimum remaining amount information of any of the color inks C, M, or Y input from the three color minimum remaining amount detection circuit 29. If the remaining amount is smaller than the minimum value of (C, M, or Y), the comparison result information is output to the determination processing circuit 31. It should be noted that the three-color minimum remaining amount detection circuit 29 and the black / color comparison circuit 30 are integrally formed, the remaining amount data of four colors are input, and the remaining amount data of four colors are compared. If the remaining amount of the ink K is smaller than the minimum remaining amount of the color inks (C, M, or Y), the comparison result information may be output to the determination processing circuit 31.

The determination processing circuit 31 is a circuit that determines the amount of each ink used in the next and subsequent printing processes based on the information on the comparison result input from the black / color comparison circuit 30. The next use amounts of the inks K, Y, M, and C) are output to a print control circuit (not shown) as shown on the right side of FIG.

As a result, the amount of consumption of each ink is detected. For example, when monochrome printing increases and black ink consumption increases compared to color ink consumption, in other words, black ink consumption decreases. When the remaining amount of black ink falls below the remaining amount of each color ink, the amount of black ink print data is reduced while taking into account the reduction of each color ink. A part or the whole is replaced with the composite print data of three colors (printing in process black) and printing is executed.

In the printing process in this embodiment, it is determined that the remaining amount of black ink is rapidly reduced irrespective of whether the configuration of the ink cartridge 4 is a four-color integrated type, a four-color separate type, or a black / color separate type. In this case, the composite printing using the three color inks Y, M, and C is performed without using the black ink on the black print portion of the print data that is currently being printed or is waiting to be printed.

Note that the initial filling amount of each ink into the ink cartridge 4 is set in advance to a capacity that assumes the amount of ink consumed when the ink cartridge 4 is used for standard color printing. In addition, printing by combining three colors refers to the fact that three color inks (yellow, cyan, magenta) are mixed in substantially equal amounts to produce black (commonly called process black). To print black portions. In other words, it utilizes the fact that process black can be replaced with black (pure black) printing using the black ink itself.

FIG. 4 is a diagram showing an example of a change in the remaining amount of ink when the printer (ink jet printing apparatus) of the present invention is used. In the figure, the horizontal axis indicates the number of prints (prints),
The vertical axis indicates the remaining ink amount. Also, a solid line 32 in FIG.
Represents the remaining amount of the ink with the smallest remaining amount among the three color inks Y, M, or C, and corresponds to the signal (remaining amount data) Min shown in FIG.

A broken line 33 in FIG. 4 is a curve showing the remaining amount of black ink. In the figure, at first, the color ink and the black ink are almost equally used from the first sheet to the a sheet, and black printing increases from the a sheet to the b sheet in the middle. The consumption of the color ink is stopped (the solid line 32 extends along the horizontal axis), and only the black ink is greatly reduced (the curve is rapidly falling).

When such a state is detected, a process of replacing the above-described printing of the black ink with the synthetic printing of the color ink is performed, and the printing is executed. This allows
As shown in the same drawing, the consumption of black ink is reduced and the consumption of color ink is increased from the above-mentioned b-th sheet, and the remaining amount of both inks approaches the same level in the c-th sheet. It is shown. In the actual control, since the control is performed at a higher speed than that shown in this figure, there is almost no extreme difference between the remaining levels of both inks as shown in the figure.

FIGS. 5A and 5B are flowcharts of a processing operation for performing printing control by replacing pure black and process black in accordance with the remaining amount of ink as described above.
FIG. 1A shows the basic form, and FIG. 1B shows a modification.

First, the basic processing operation will be described with reference to FIG. First, the remaining ink amounts are compared (step S
1). In this process, black ink K and each color ink Y,
The remaining amounts of M and C are compared respectively. That is, whether or not the remaining amount of the black ink K is smaller than any of the remaining amounts of the color inks Y, M, or C is compared. In this comparison method, as shown in FIG. 3, first, the remaining amounts of the three color inks Y, M, and C are compared with each other, and it is detected which of the three colors is the smallest. You. Then, of the three colors, the color ink Y, M, or C having the least amount of remaining ink.
Is compared with the remaining amount of black ink K.

As a result, if any one of the inequalities of “K <Y”, “K <M”, or “K <C” is satisfied (see the number of printed sheets a on the horizontal axis in FIG. 4). ), The remaining amount of the black ink K is determined to be smaller than the remaining amount of the color ink (Y in S1), and the three color inks Y, M and C are used to process black. Printing is performed (S3). Thereby, printing from the b-th sheet to the c-th sheet shown on the horizontal axis in FIG. 4 is performed.

On the other hand, in step S1, "K <Y",
If neither of the inequalities “K <M” or “K <C” is satisfied, that is, if all the expressions “Y ≦ K”, “M ≦ K”, and “C ≦ K” are satisfied (S1 is N ), Normal printing is performed using the black ink K (step S3). Thus, in FIG. 4, printing is performed from the first sheet to the a-th sheet or the c-th sheet and thereafter from the first sheet shown on the horizontal axis.

In the comparison process of the inequality expressions "K <Y", "K <M" or "K <C", for example, the inequality expression "K <
When “Y” is established, and when the difference is small as in the equation “Y = K + k” (k = ΔK), when process black printing is performed instead of pure black printing as described above,
If the printing amount is large, the amount of color ink is reduced too much and the amount of black ink is increased when printing is completed, and this may contradict the purpose of the above processing.

FIG. 5B shows a process for coping with such a situation. As a modified example of the above process, a process for making the remaining ink amounts after printing as uniform as possible is shown. . In FIG. 2B, first, all print data is received (step S01), the print data is decomposed for each color, and the amount of black print data is extracted (step S02).

Subsequently, the remaining ink amounts are compared (step S03). In this process, first, based on the print data separated for each color, the future ink usage amounts y, m, and c of each color ink are calculated, and the extracted black print data is also calculated from now on. It is converted to black ink usage k. Then, the remaining amount of black ink and the remaining amount of color ink after printing are compared.

As a result, “(K−k) <(Y−y)”,
“(K−k) <(M−m)” and “(K−k) <(C−
c), if any one of the inequalities is satisfied, the remaining amount of black ink K “Kk” is changed to the remaining amounts of color inks “Yy” and “Mm” after printing is completed. Or "C-
c) (S03: Y), the process black printing is performed using the three color inks Y, M, and C (S05). On the other hand, “(K−k) <(Y−
y) "," (Kk) <(Mm) "and" (Kk)
If none of the inequalities <(Cc)> holds (N in S03), normal printing is performed (step S0).
4).

By repeating this process, for example, every one line or every several lines, the remaining amounts of the black ink and the color ink are always maintained in a uniform state. In addition, since the printing by the process black is different in color from completely black, unlike the printing by the pure black, the above-mentioned disadvantages are more likely to be applied to a solid black portion in which the above-mentioned disadvantages are less noticeable than replacing the pure black printing with the process black printing 100%. It can be said that it is preferable to arrange pure black printing and process black printing while mixing them appropriately.

In the process of replacing black ink with three color inks as in this example, if it is difficult to achieve high precision in the landing positions of the ink droplets of each color, color misregistration is performed separately from the above-described color problem. Problems may arise. In such a case, it is preferable to control so as to make the result of the processing (synthetic printing) inconspicuous, and in this case also to partially use the synthetic printing in the solid black portion as described above. Of course, if the accuracy of the ink droplet landing position of each color is sufficient, such consideration is not necessary. For example, even in a print portion where the accuracy of the landing position is the most important, such as a black line portion, the above-described replacement process can be performed without any problem. It goes without saying that the application is possible.

FIG. 6 shows that when it is determined that the remaining amount of black ink is smaller than the remaining amount of color ink, a part of the black print data is replaced with process black to mix pure black and process black. FIG. 7 is a diagram illustrating an example of a case where printing is performed while printing. In the example shown in the figure, in the solid black portion 34 of the image, black print dots are alternately arranged in a checkered pattern both vertically and horizontally by pure black dots 35 and process black dots 36. When printed in this way, the difference in color between pure black and process black and the misregistration of the three colors are inconspicuous, visually recognized as a uniform black, and the amount of black ink used for process black is saved from excessive consumption. Is done.

FIG. 7 is a flowchart showing the processing operation of the mixed printing of the pure black and the process black. In the figure, steps M1 and M2 are performed as shown in FIG.
This is the same process as steps S01 and S03. FIG.
In the comparison of the remaining amounts of the black ink K and the color inks Y, M, and C in step M3 of FIG. 5, since part of the black print data is printed in process black, FIG.
The condition is that the remaining amount of each color ink is larger than in the case of.

Therefore, for example, the remaining amount K of black ink (actually K−k) is multiplied by 1.2 to obtain the remaining amount Y of each color ink,
Compare with M and C. That is, 1.2K <Y, 1.2K <
If any of the inequalities of M or 1.2K <C is satisfied (M3 is Y), a part of the black print data is divided into three colors to save a large decrease in black ink. Is printed in process black using the color inks Y, M, and C (steps M4 to M6).

In the example shown in the figure, for example, 1/2 of the print data of the black portion is extracted as black data A (step M).
4) This print data (black data A) is printed in process black using three colors of inks Y, M and C (step M5). Then, the remaining 1/2 print data (black data B) is extracted (step M6), and normal printing is performed (step M7). As a result, the remaining 1/2
Is printed in pure black.

In step M3, 1.2K <
When none of the inequalities of Y, 1.2K <M, or 1.2K <C hold (M3 is N), since each color ink does not remain much in comparison with the black ink, Yes, in this case, normal printing in step M7 is performed.

Note that the above inequality 1.2K <Y, 1.2K
<M or 1.2K <C is considered after consuming color ink instead of black ink, and the inequality K <0.8Y, K
<0.8M or K <0.8C. The coefficients to be integrated are “1.2” and “0.
The value is not limited to “8” and may be an appropriate value according to the case. Also, the division of the print data of the black part is 50% as described above.
For example, the print data of the black portion of the image data may be extracted as the black data A, and the black print data of the text may be extracted as the black data B.

FIG. 8 is a flowchart showing still another example of processing performed while detecting the remaining amount of ink. This processing is also applicable to a printer in which the ink cartridge is independent of the print head, as in the above-described example, and the amount of black ink required for the print data to be printed is small. If it is determined that printing is being performed while replacing the black ink with color ink without stopping the operation for ink replacement in the middle of printing, the printing result for the currently waiting print data is It is intended to be processed so as to be obtained.

In the figure, first, the entire print data to be printed is obtained (STEP-1). Next, print data using black ink is extracted from the print data (STEP-2). Then, a black ink usage amount is calculated from the extracted print data, and the calculated black ink usage amount is compared with the current black ink remaining amount (STK).
EP-3) If the remaining amount of black ink is sufficient, a normal printing process is performed (STEP-5).

If the remaining amount of black ink is not sufficient in STEP-3, it is determined whether the remaining amount of color ink to be used in place of the black ink to be used is sufficient (STEP-4). If the remaining amounts of the three color inks are sufficient, the black / color ink replacement printing process of the present invention is executed (STEP-6).

In the above STEP-4, when the color ink is also insufficient, a normal printing process is performed (STEP-4).
7) After the ink replacement operation due to ink exhaustion during printing, normal printing processing is continued again (STEP-8).

As described above, in any of the embodiments of the present invention, the printing process is executed by replacing black printing with color ink only when the remaining amount of black ink is not sufficient for the print data. An object of the present invention is to make it possible to print currently requested print data without delay.
In addition, the replacement process at the time of printing is most suitable to be performed around a solid solid black portion, which is inconspicuous even when black printing is performed using process black, since there is little change in apparent image quality.

In FIG. 3 described above, the three-color minimum remaining amount detection circuit 29 and the black / color comparison circuit 30 are integrated,
The configuration may be such that four colors are simultaneously compared and a detection signal is output to the determination processing circuit 31 when the remaining amount of black ink is the smallest.

Recently, an ink jet printer using six or seven color inks using diluted ink has also appeared, but the above-mentioned control of the amount of ink used is controlled by such six or seven color inks. The present invention can be applied to an ink jet printer using a color ink.

When the present invention is not used, the frequency of use of black ink alone must be predicted in advance, and a user who frequently uses black ink must design a larger amount of black ink. However, this causes a problem that a user who uses the black ink less frequently has to replace the ink cartridge in a state where the remaining amount of the black ink is extremely large. Therefore, it is necessary to design a smaller amount of black ink only for a user who uses black ink less frequently. In this case, the advantage of simplicity of using the four-color integrated cartridge is lost, and in any case, the problem is not solved.

[0066]

As described above in detail, according to the present invention, in an ink jet printer using a four-color integrated cartridge containing black ink and color ink in one cartridge, the black ink and the black ink Since the consumption of the color ink is controlled so as to be substantially the same, the consumption of the black ink and the consumption of the color ink can be made substantially the same. The inconvenience of having a large amount of remaining ink can be solved, and therefore, the ink of the four-color integrated cartridge is not wasted.

Further, even if the ink cartridge is not a four-color integrated ink cartridge, the frequency of running out of ink during printing can be reduced, so that the trouble of replacing the ink cartridge during printing can be eliminated. And convenient.

[Brief description of the drawings]

1A is a perspective view schematically showing a configuration of an ink jet printing apparatus according to an embodiment, FIG. 1B is an enlarged view of a print surface of a print head, and FIG. 1C is an enlarged sectional view of an ink cartridge. .

FIG. 2 is a block diagram illustrating a system configuration of the inkjet printing apparatus.

FIG. 3 is a block diagram of a main circuit that controls the type of ink used by the print head according to the remaining amount of ink.

FIG. 4 is a diagram illustrating an example of a change in the remaining amount of ink when the inkjet printing apparatus of the present invention is used.

FIG. 5A is a basic flowchart of a processing operation for performing printing control by replacing pure black and process black, and FIG. 5B is a flowchart showing a modified example thereof.

FIG. 6 is a diagram illustrating an example of a case where printing is performed while mixing pure black and process black.

FIG. 7 is a flowchart illustrating a processing operation of mixed printing of pure black and process black.

FIG. 8 is a flowchart showing still another processing example.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Ink-jet printing apparatus (printer) 2 Carriage 3 Print head 4 Ink cartridge 4b (4b-1, 4b-2, 4b-3, 4b-4) Ink chamber 5 Guide rail 6 Toothed drive belt 7 Flexible communication cable 8 Device body Frame 9 platen 10 paper 11 paper feed roller pair 12 paper discharge roller pair 13 motor 14 (14y, 14m, 14c, 14k) nozzle row 15 (15k-1, 15k-2, 15k-3, 15k-)
4) Nozzle 17 Stationary part 18 Moving part 19 Heat generation drive driver 20 MPU (micro processing unit) 21 Bus 22 I / F (Interface) 23 Head control part 24 Memory A 25 Memory B 26 PC (Personal computer) 27 Output of each sensor 28 Various drive signals 29 Three-color minimum remaining amount detection circuit 30 Black / color comparison circuit 31 Judgment processing circuit 32 Ink remaining amount curve with least remaining amount 33 Black ink remaining amount curve 34 Black solid portion of image 35 Pure black・ Dot 36 Process black ・ Dot

Claims (4)

[Claims] 1. An ink jet printing apparatus comprising: an ink storage section for storing yellow, magenta, cyan, and black inks, and performing printing by discharging ink toward paper from discharge nozzles provided for each color. Storage means for storing print data; detection means for detecting the remaining amounts of yellow, magenta, cyan, and black inks prior to a printing operation; and yellow, magenta, cyan, and black colors detected by the detection means. Comparing means for comparing the remaining amount of ink and outputting a comparison signal when the remaining amount of black ink is the smallest, and print data stored in the storage means based on the comparison signal output by the comparing means. And print control means for printing black print data using yellow, magenta and cyan inks. Ink jet printing apparatus. 2. An ink jet printing apparatus comprising: an ink storage section for storing yellow, magenta, cyan, and black inks, and performing printing by discharging ink toward paper from discharge nozzles provided for each color. Storage means for storing print data; conversion means for converting a print data amount of each color of the print data stored in the storage means into an amount of ink used to obtain a conversion value for each color; , Magenta, cyan, and black ink remaining amounts, and ink usage amounts obtained by the conversion value means from the yellow, magenta, cyan, and black ink remaining amounts detected by the detection means And comparing means for comparing the values obtained by subtracting the converted value of black ink from the remaining amount of black ink and outputting a comparison signal when the value obtained by subtracting the converted value of black ink is the smallest. Print control means for printing black print data of the print data stored in the storage means using yellow, magenta, and cyan inks based on the comparison signal output by the comparison means. An inkjet printing apparatus characterized by the above-mentioned. 3. The printing control device according to claim 1, wherein the printing control means prints only a predetermined percentage of the printing data of the black printing data by using yellow, magenta, and cyan inks. Inkjet printing equipment. 4. The printing control means according to claim 1, wherein only the image data of the black printing data is printed using yellow, magenta and cyan inks.
Or the inkjet printing apparatus according to 2.