JP2003145808A - Apparatus and method for correcting printing data, and software recording medium with printing data correction program recorded - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problem that it is utterly impossible to compare patches with each other for all reproducible colors if a printing head has the machine specificity. SOLUTION: When a recording material such as a color ink for constituting dots as in an ink jet system printer 31 changes by the machine specificity, it is impossible to set a correction amount for a color shift for each color. However, a suitable color correction is facilitated for a secondary color or a tertiary color as well by obtaining the correction amount for at least a single color, determining an aiming color, reducing the correction amount for the single color by an optimum reduction amount, and adopting the amount.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a print data correction device, a print data correction method, and a software recording medium recording a print data correction program.

[0002]

2. Description of the Related Art In recent years, color ink jet printers have been improved in definition and have come to be called so-called photographic image quality. Such an ink jet printer ejects a predetermined color ink in a granular form to attach dots of a predetermined color at a desired position and express an image in a dot matrix form. In this case, a color image is reproduced using three color inks of cyan (C), magenta (M), and yellow (Y) or four color inks in which black (K) is added.

By the way, in order to be called photographic image quality, it is important to make the dots fine, but color reproducibility is also extremely important. Although the color is represented by multi-tone data of red, green, and blue (RGB) inside the computer, the printer can only handle CMYK two-tone data, so color space conversion and gradation conversion are performed. It is being appreciated. That is, CMYK two-gradation display is realized while maintaining the colors expressed by RGB multi-gradation. Of course,
Here, it is premised that each dot develops color at a specified density.

However, despite the fact that the print data is output while maintaining the color reproducibility, the weight of the color ink particles varies depending on the machine body of each print head, and as a result, each dot has its original color. In some cases, it may not be said that the color is developed depending on the density.

[0005]

In the above-mentioned conventional printing apparatus, if the amount of ink particles ejected differs due to the difference in the body of the print head, it cannot be said that each dot develops its original density. As a result, there is a problem that the color reproducibility may deteriorate.

Therefore, the applicant of the present invention has decided to improve the color reproducibility by correcting the print data in advance to compensate for the machine difference and printing based on the corrected print data. Such modification uses a modification table. To create this correction table, first,
A reference print head that ejects color ink particles of a reference weight prints a patch over all tones, and a print head with a machine-difference also prints a patch over all tones. Then, each patch is compared to obtain a combination of patches having no error, and the combination list is used as a correction table.

Since it is necessary to compare and contrast patches in this manner, it is very difficult to compare patches for all reproducible colors. Therefore, when a correction table is created for each element color, when printing a single color, it is possible to obtain almost the same color development as in the case of the reference head, but when color mixing occurs, a deviation occurs again.

The present invention has been made in view of the above problems, and a print data correction device, a print data correction method, and a print data correction method capable of reproducing colors more accurately regardless of machine differences such as a print head. An object of the present invention is to provide a software recording medium recording a print data correction program.

[0009]

In order to achieve the above object, the invention according to claim 1 provides a recording material for each element color in order to print out a color image with a plurality of element colors based on print data. A print data correction device that corrects the above print data in order to compensate for a color change due to a bias in the usage amount of the recording material for a printing device that is attached to a recording medium in a dot matrix form, and for each element color A correction unit that corrects the print data based on a predetermined correction amount that compensates for the deviation of the usage amount of the recording material that has been set, and the correction performed by the correction unit when a color mixture is realized by combining each element color, as compared with a single color And a correction amount reducing means for reducing the amount.

In the invention according to claim 1 configured as described above, the correction means corrects the print data on the basis of a predetermined correction amount for compensating the bias of the usage amount of the recording material set for each element color. Based on the corrected print data, the printing apparatus attaches a recording material for each element color to the recording medium in a dot matrix form, and prints out a color image with a plurality of element colors. In this case, the correction amount reducing means reduces the correction amount when mixing colors realized by combining the respective element colors when the correction means corrects the print data as compared with the case of a single color.

When the correction amount for a single color is applied to mixed colors, an experimental result has been obtained that the correction amount set as a single color is too strong. There are various possible causes for this, but it is reasonable to think that the amount of correction for each element color will have a strong effect due to color mixing, and by reducing the amount of correction during color mixing, it is possible to set a single color state. The corrected amount is not used as it is in the case of color mixing, and the reproducibility of color mixing is improved.

Here, the correction means has at least a correction amount for each element color in a single color, and corrects the print data by reducing the correction amount based on an instruction from the correction amount reduction means. It may be corrected individually for each print data, or if there is a conversion table that the print data refers to, the same conversion table should be corrected collectively and the same conversion table is It may be such that conversion and modification are performed by reference.

Further, the correction amount reducing means may eventually reduce the correction amount by the correcting means when the colors are mixed, as compared with the single color, and the reduction amount is not uniform. However, as an example thereof, the invention according to claim 2 is such that, in the print data correction device according to claim 1, the correction amount reducing means further reduces the correction amount as the number of colors to be mixed increases. is there.

In the invention according to claim 2 configured as described above, the correction amount reducing means reduces the correction amount as the number of colors to be mixed increases.

It is considered that the amount of correction when monochromatic is used when mixing colors is mixed is too strong, and it is preferable to extend this idea so that the correction amount becomes weaker as the number of mixed colors increases. Becomes

The tendency for reducing the correction amount is as described above, but in reality, there are single colors and mixed colors, and the number of colors is also mixed. Therefore, adjustment is required to determine the correction amount. As a preferred example in such a case, the invention according to claim 3 is the print data correction device according to claim 1 or 2, wherein the correction amount reducing means is adapted to match the number of colors to be mixed. The reduction amount storage means for storing the optimum reduction amount and the reduction amount weighting addition means for totaling the number of colors mixed in each pixel and adding the reduction amount with weighting corresponding to the number of pixels are configured. .

In the invention according to claim 3 configured as described above, the reduction amount storage means stores the optimum reduction amount according to the number of colors to be mixed, and the reduction amount weighting and addition means stores the color mixture of each pixel. The number of colors to be added is totaled, and the reduction amount is added by weighting corresponding to the number of pixels.

Therefore, the optimum reduction amount is added for each number of colors to be mixed by weighting according to the ratio of the number of pixels, and the reduction amount becomes harmonious for the entire printed matter.

The method of reducing and applying the correction amount set for each element color in the case of color mixture does not necessarily have to be a substantial device, and as an example, the invention according to claim 4 is: Based on the deviation of the usage amount of the recording material for the printing device that attaches the recording material for each element color to the recording medium in a dot matrix form in order to print out a color image with a plurality of element colors based on the print data A print data correction method for correcting the print data in order to compensate for a color change, wherein a predetermined correction amount for compensating the bias of the usage amount of the recording material is set for each element color, and each element When the colors are mixed by combining the colors, the correction amount is reduced as compared with the case of the single color, and the print data is corrected.

That is, there is no difference in that the method is not limited to the work of correcting with a substantial device, and that the method is effective.

By the way, as described above, the print data correction device for correcting print data may exist as a single device or may be used in a state of being incorporated in a certain device. It includes the aspect of. Further, it can be changed as appropriate, such as being realized by hardware or software.

When it comes to software for color correction as an example of embodying the idea of the invention, it naturally exists on a software recording medium recording such software,
There is no choice but to say that it will be used.

As an example thereof, in the invention according to claim 5, the recording material for each element color is attached to the recording medium in a dot matrix form in order to print out a color image with a plurality of element colors based on the print data. A software recording medium recording a print data correction program for correcting the print data in order to compensate for a color change based on a deviation of the usage amount of the recording material by a computer with respect to the printing device,
A predetermined correction amount is set for each element color to compensate for the bias in the usage of the recording material, and when the color is realized by combining the element colors, the correction amount is reduced as compared with the case of a single color, and the printing is performed. The data is modified.

Of course, the software recording medium may be a magnetic recording medium or a magneto-optical recording medium, and any software recording medium developed in the future can be considered in exactly the same manner. In addition, the duplication stage of the primary duplication product, the secondary duplication product, and the like is absolutely the same. In addition, the present invention is used even when a communication line is used as a supply method, and the same applies to a case where the present invention is written in a semiconductor chip.

Further, even when a part is software and a part is realized by hardware, there is no difference in the idea of the invention, and it is necessary to store a part on a software recording medium. It may be in a form that can be appropriately read according to the above.

[0026]

As described above, according to the present invention, there is no difficulty in obtaining the correction amount of color mixture in the sense that the correction amount is set for each element color, and the correction amount is weakened at the time of color mixing. Since it is adapted, it is possible to provide a print data correction device capable of substantially eliminating color misregistration due to machine differences and improving color reproducibility.

According to the second aspect of the invention, the correction amount is reduced as the number of mixed colors increases,
When the number of colors is large, the correction amount for each color is weakened, and good color reproducibility can be realized.

Further, according to the invention of claim 3,
Since the number of pixels for each color mixture color is aggregated and the optimum reduction amount is weighted and added to each, a harmonious reduction amount can be obtained.

Further, according to the invention of claim 4,
Similarly, it is possible to provide a print data correction method capable of improving color reproducibility during color mixing.

Further, according to the invention of claim 5,
Similarly, it is possible to provide a software recording medium recording a print data correction program capable of improving color reproducibility during color mixing.

[0031]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing a print data correction device according to an embodiment of the present invention, and FIG. 2 is a block diagram showing a hardware configuration example of a printing system to which the print data correction device is applied. Shows.

This printing system can be roughly classified into an image input device 10, an image processing device 20, and a printing device 30. The image input device 10 corresponds to a scanner 11, a digital still camera 12 or a video camera 14, and the image processing device 20 includes a computer 21, a hard disk 22, a keyboard 23 and a CD-R.
The OM drive 24, the floppy (registered trademark) disk drive 25, the modem 26, the display 27 and the like correspond, and the printer 31 and the like correspond to a specific example of the printing device 30. It should be noted that the modem 26 is connected to a public communication line and can be connected to an external network via the same public communication line so that software and data can be downloaded and introduced.

Here, the scanner 11 and the digital still camera 12 as the image input device 10 output image data of 256 gradations of RGB (green, blue, red) as image data, and the printer 31 as the printing device 30 Image data of two gradations of CMYK (cyan, magenta, yellow, black) is required as an input. Therefore, in the computer 21 as the image processing apparatus 20, the 256-gradation image data is input, predetermined image processing and printing processing are performed, and output as 2-gradation image data. An operating system 21 a is operating in the computer 21, and the printer driver 21 b and the display driver 21 corresponding to the printer 31 and the display 27 are provided.
c is installed and the application 21
d is controlled by the operating system 21a to perform processing, and displays on the display 27 in cooperation with the display driver 21c, and executes print processing in cooperation with the printer driver 21b as necessary.

In the present embodiment, the print data correction device 30a inputs the generated print data in the process of generating the print data in such a printing system, corrects the predetermined data, and outputs the corrected data. in this case,
The correction unit 30a1 holds a correction amount for correcting the machine body difference for each element color in advance as described later, and the correction amount is reduced by a reduction instruction from the correction amount reduction unit 30a2 to print data. Fix it. Hereinafter, this step will be described in detail.

First, the printer 31 that prints based on the corrected print data will be described. FIG. 3 shows a schematic configuration of the printer 31, which includes a print head 31a including three print head units and the print head 31a.
a, a print head controller 31b for controlling a, a print head digit moving motor 31c for moving the print head 31a in the digit direction, a paper feed motor 31d for feeding the print paper in the row direction, the print head controller 31b and the print head. A dot printing mechanism including a digit moving motor 31c and a printer controller 31e, which is an interface with an external device in the paper feed motor 31d, is provided, and an image can be printed according to print data.

FIG. 4 shows a more specific structure of the print head 31a, and FIG. 5 shows the operation during ink ejection. The print head 31a is formed with a fine conduit 31a3 from the color ink tank 31a1 to the nozzle 31a2, and the ink chamber 31a is formed at the end of the conduit 31a3.
4 are formed. The wall surface of the ink chamber 31a4 is formed of a flexible material, and the wall surface is provided with a piezo element 31a5 which is an electrostrictive element. The piezo element 31a5 has a crystal structure that is distorted by applying a voltage and performs high-speed electrical-mechanical energy conversion.
The wall surface of 1a4 is pushed to reduce the volume of the ink chamber 31a4. Then, a predetermined amount of color ink particles are vigorously ejected from the nozzle 31a2 communicating with the ink chamber 31a4. This pump structure will be called a micro pump mechanism.

Two independent rows of nozzles 31a2 are formed in one print head unit, and the color inks are independently supplied to the nozzles 31a2 of each row. Therefore, each of the three print head units has two rows of nozzles, and it is possible to use six color inks to the maximum extent. In the example shown in FIG. 3, two rows in the print head unit in the left column are used for black ink, only one row in the middle print head unit is used for cyan ink, and two rows in the print head unit in the right column are used. The two columns on the left and right are used for magenta ink and yellow ink, respectively.

As described above, the present embodiment is applied to the ink jet type printer 31 employing the micro pump mechanism. In the printer 31 having an ink jet type dot attachment mechanism,
Printing is performed by ejecting one ink particle for each dot from the print head 31a described above. However,
The size of one dot applied in this way is not always constant, and there is a machine difference in the print head 31a. In the case where the print density does not change due to so-called overprinting, the dot size affects the print density. Therefore, when the dot size varies from machine to machine, the print density varies, and in color, the color balance and lightness vary, and in monochrome, the density of gray varies.

In the present embodiment, the ink jet type printer 31 which employs the micro pump mechanism has been described, but any printer having another dot attaching mechanism may be used as long as the dot size causes a machine difference. Applicable.

For example, as shown in FIG. 6, the nozzle 31a6
The heater 31a8 is provided on the wall surface of the nearby conduit 31a7, and the bubble jet (registered trademark) type pump mechanism that heats the heater 31a8 to generate bubbles and discharges color ink by the pressure is also put into practical use. Has been done. Also in this case, the ability of the heater 31a8 and the nozzle 31a6
It is undeniable that there will be differences in the aircraft due to the shape of the openings in the.

As another mechanism, FIG. 7 shows a schematic structure of a so-called electrophotographic printer 33. A charging device 33b, an exposure device 33c, and a developing device 33 are provided on the peripheral edge of the rotary drum 33a as a photoconductor in correspondence with the rotation direction.
d and the transfer device 33e are arranged, the charging device 33b uniformly charges the peripheral surface of the rotary drum 33a, and then the exposure device 33c removes the charge on the image portion, and the developing device 3
Toner is attached to the uncharged portion in 3d, and the toner is transferred onto paper as a recording medium by the transfer device 33e. After that, the toner is melted by passing between the heater 33f and the roller 33g and fixed on the paper.

Even in the case of such an electrophotographic printer 33, the amount of toner adhered varies due to the difference between the charging device 33b, the exposure device 33c or the rotating drum 33a itself. Therefore, the same problem as in the inkjet printer 31 occurs.

In the present embodiment, the image input device 10
Although a computer system is incorporated between the printer and the printing device 30 to perform the printing process, such a computer system is not necessarily required. For example, as shown in FIG. 8, in the printer 32 that inputs and prints image data without going through a computer system, the scanner 11b and the digital still camera 12 are used.
It is also possible to input image data as print data input via b or the modem 26b and make a correction to eliminate the machine difference.

Next, the correction means 30a1 will be described. FIG. 9 shows the flow of the image data, and is the RGB represented by the image input device 10 as the dot matrix pixels.
Image data of multiple gradations (256 gradations)
0, the image processing apparatus 20 performs predetermined image processing and outputs to the printing apparatus 30 as CMYK two-gradation image data (binary data). Image processing device 20
In this, color conversion processing from the RGB color space to the CMYK color space is performed, and in this processing, image data of 256 gradations of RGB is converted into image data of 256 gradations of CMYK. After that, in view of the fact that the data that can be input to the printing apparatus 30 has two gradations, halftone processing is executed to convert the image data of 256 gradations into the image data of two gradations. The image data is printed as print data by the printing device 30 through such a process.
However, it can be called print data in a broad sense because it is data for substantially the same image in the process before that. In principle, the above-described print data correction device 30a can perform correction processing on print data at any stage. It shall be done on the data.

FIG. 10 shows a procedure for rewriting the color conversion table for performing the correction processing as the color conversion processing. Here, the contents will be described according to the procedure.

First, in step S100, a correction lookup table for a primary color (single color) is created. Here, the procedure for creating this correction lookup table will be described.
As described above, first, the patch is printed over the entire gradation by the reference print head 31a that ejects the reference color ink particles. In the present embodiment, since there are 256 gradations, the printed patch has a grid pattern of 16 rows and 16 columns as shown in FIG. Next, the print head 31a having a different machine body
But in the same way, patches are printed over all gradations. In the print head 31a having a different machine body, since the weight of the ejected ink particles is different, the print density is different, and the reference print head 31
It does not match the patch printed over all gradations in a.

Therefore, as shown in FIG. 12, each patch printed by the reference print head 31a is individually compared with each patch printed by the print head 31a having a machine difference, and the gradations of the matching patches are compared. . In the figure, a combination of patches that are printed when predetermined gradation data is input and have the same print density is shown. Therefore, this combination directly constitutes the correction lookup table. In the present embodiment, three print heads 31a are provided, so a correction lookup table is created for each print head 31a. The correction look-up table has the correction amount described above, and in this sense, it can be said that the correction amount is a correction amount for each element color.

By using the correction look-up table created for each print head 31a in this manner, it is possible to perform the correction in the same manner for the colors other than the primary color.
In reality, when a mixed color such as a secondary color or a tertiary color is used, a deviation appears.

Therefore, in step S110, the correction amount in the correction look-up table is reduced and the patch of the secondary color is printed. Here, the adjustment of the reduction amount is represented by multiplying the correction amount by a predetermined coefficient, and the same coefficient is set to "0.
FIG. 1 shows a correction look-up table in the case of 1 ”increments.
3 shows. Since the amount of correction is small in the low gradation region and the high gradation region, it is difficult to see the change. However, when looking at the gradation "180" where the correction amount is the maximum, when the coefficient is "1.0", the correction amount becomes " It can be seen that the correction amount is reduced by almost "2" gradation data by decreasing the coefficient in increments of "0.1" for the difference of 20 "gradation data. Of course, for secondary colors, each print head 3
Use a separate correction look-up table in 1a, multiplied by the same coefficient. The step size of the coefficient in this case does not necessarily have to be "0.1".

In step 120, the patches of the reference print head 31a thus printed for the secondary colors and the patches of the print head 31a having a machine difference with a different coefficient α2 are subjected to color measurement, and as a whole. The coefficient α2 that reduces the error is determined. According to the experimental results, the coefficient α2
Was most preferably "0.8".

Next, the coefficient α3 for the tertiary color is determined by the same method. That is, in step S130, the coefficient α3 is changed to print the patches of the tertiary color, and in step S14
At 0, the optimum coefficient α3 is determined in comparison with the patch on the reference print head 31a. It was confirmed that the optimum coefficient α3 for this tertiary color is about “0.6”.

However, while there are optimum coefficients for each of the primary color to the tertiary color as described above, the print data includes various colors from the primary color to the tertiary color. Therefore,
The coefficient must be adjusted depending on which dimension of color reproducibility is important. In step S150, such an aiming color is determined and which coefficient is to be adopted.

Although the aiming color is determined here and the coefficient is determined based on the aiming color, the coefficient is determined by aggregating the number of pixels of the actual primary color, secondary color and tertiary color. Is also good. FIG. 14 shows a result of summing up the numbers of pixels of primary colors to tertiary colors based on all pixels of print data. The coefficient is weighted from the result of this aggregation. In the example shown in the figure, the number of pixels of the primary color is s1 and the number of pixels of the secondary color is s.
Since the number of pixels of the secondary color is s3 and the number of pixels of the tertiary color is s3, the coefficients are weighted and added at a ratio to the total number of pixels (S = s1 + s2 + s3).

That is, the coefficient α0 that satisfies α0 = 1.0 × (s1 / S) + α2 × (s2 / S) + α3 × (s3 / S) (1) is used. On the other hand, if the components of one element color are mixed with the components of another element color even a little, it is judged that they are necessarily secondary colors or tertiary colors, and the number of primary colors and secondary colors is quite large. Will decrease. However, in such a case, even if the correction is made more strongly, the original component is small, so that the adverse effect is small. Therefore, it is also effective to determine that the color is a secondary color or a tertiary color only in a mixed color state in which relatively other element colors cannot be ignored.

FIG. 15 shows, as an example, an aggregated result when a judgment is made based on the component ratio of each element color, and the element color having a component value of 20% or less with respect to the maximum component value is ignored. That is the case. As a result, the number of pixels of the primary color and the secondary color is increased, which also affects the coefficient α0.

As described above, when the pixels are totaled based on the print data and the totalized result is reflected, the optimum coefficients are obtained for each of the primary color, secondary color, and tertiary color. The hardware and software for storing the reduction amount storage means constitute reduction amount storage means, and the processing of totaling the number of pixels of each primary color, secondary color, and tertiary color from the actual print data and weighting and adding the reduction amount weighting and adding means Will be configured.

For the color correction, CMYK print data may be used to refer to this correction look-up table.
Since the color conversion table is referred to in the color conversion from CMYK to CMYK, rewriting the color conversion table also ends the correction work with a single table reference. Therefore, in step S160, the correction lookup table of the determined coefficient is written in the color conversion table.
Of course, since the coefficient is determined in this way in correspondence with the aiming color and the correction amount multiplied by the coefficient is written in the color conversion table, these processes are performed by the correction amount reducing means 30.
a2 is configured.

The above-described procedure is executed when the printer driver 21b is started up by the computer 21, and the operation of the present embodiment having the above-mentioned configuration will be described below with reference to the flowchart of the printer driver 21b shown in FIG. Will be explained.

Assuming that the image data read by the scanner 11 is printed by the printer 31, first, the application 21d is started while the operating system 21a is running on the computer 21,
The scanner 11 is caused to start reading. When the read image data is loaded into the application 21d via the operating system 21a, predetermined image processing is performed and print processing is selected.

When the printing process is selected, the operating system 21a activates the printer driver 21b. Since the primary color correction lookup table does not exist at the first startup of the printer driver 21b, step S2 is performed.
After the determination of 00, a monochrome patch is printed in step S205. On the other hand, the patch printed by the reference print head 31a is prepared separately, and compared with the patch printed by the print head 31a provided for each printer 31,
In step S210, the value for which the correspondence is obtained is input.

Utilizing this result, the patch of the secondary color is printed in step S215. At this time, the coefficient is changed to print some patches, and in step S220, the coefficient α2 for the patch considered to be optimum is determined. Similarly, in step S225, a patch of a tertiary color is printed, and in step S230, the coefficient α for the patch considered to be optimum is printed.
Determine 3. As the coefficient α2 and the coefficient α3, the coefficient for what seems to be optimum will be input. The above processing is effective once performed as long as the print head 31a does not change.

However, these steps S215 to S23
The processing of 0 is premised on that it is necessary to obtain the coefficients α2 and α3. The coefficients α2 and α3 were experimentally determined to be “0.8” and “0.6”, respectively.
Have been found to be suitable, and these values can be used as defaults with good results. Therefore, at least steps S205 and S21
If a single-color patch is printed at 0 and a predetermined corresponding value can be input, the processes of steps S215 to S230 may be omitted.

At the first start-up, the above-described printing and input are performed, the aiming color in the next step S235 is determined, the corresponding coefficient is determined, and the process of writing in the color conversion table is performed in step S240.

However, the process here needs to be executed when it is desired to change the aiming color, and even if it is determined in step S200 that it is not necessary to create the correction lookup table for the primary color, the process proceeds to step S245. Whether or not it is necessary to change the aiming color, and if necessary, the processes of steps S235 and S240 are executed.

After that, the RGB print data created by the application 21d is CMY in step S250.
Color conversion to print data of K. Of course, what is used for the color conversion at this time is the color conversion table in which the predetermined correction amount is written in step S240, and the necessary correction is added at the same time as the color conversion.

When the color conversion is completed, the print data is 2
Since there are still 56 gradations, in step S255, the printer 31 converts the print data into two gradations that can be input and outputs the print data to the printer 31. When the printer 31 inputs such print data, the reduction amount of the correction look-up table has an optimum value in the vicinity of the aiming color, and clear printing without color misregistration can be performed as in the case of printing with the reference print head 31a. It will be possible.

As described above, when the recording material such as the color ink forming the dots is changed due to the machine difference like the ink jet type printer 31, it is impossible to set the correction amount of the color misregistration for each color. However, at least the correction amount for a single color is determined, and if the aiming color is determined, the correction amount for the single color is reduced by the optimal reduction amount and then applied. Is possible.

[Brief description of drawings]

FIG. 1 is a diagram corresponding to claims of a print data correction device of the present invention.

FIG. 2 is a block diagram showing a specific hardware configuration example of a printing system to which the same print data correction apparatus is applied.

FIG. 3 is a schematic block diagram of a printer.

FIG. 4 is a more detailed schematic explanatory diagram of a print head unit in the printer.

FIG. 5 is a schematic explanatory diagram showing a situation in which color ink is ejected by the print head unit.

FIG. 6 is a schematic explanatory view showing a situation in which color ink is ejected by a bubble jet type print head.

FIG. 7 is a schematic explanatory diagram of an electrophotographic printer.

FIG. 8 is a schematic block diagram showing another application example of the print data correction apparatus of the present invention.

FIG. 9 is a block diagram illustrating a specific procedure of print processing.

FIG. 10 is a flowchart showing a procedure for rewriting a color conversion table.

FIG. 11 is a diagram showing patches to be printed.

FIG. 12 is a diagram showing a comparison state of a patch by a reference print head and a patch by a print head having a machine body difference.

FIG. 13 is a diagram showing a correction lookup table in which the coefficient is changed.

FIG. 14 is a diagram showing a histogram when a coefficient is determined according to a distribution ratio of pixels.

FIG. 15 is a diagram showing a histogram corresponding to the distribution ratio of pixels and a case where a threshold value is used during aggregation.

FIG. 16 is a flowchart of a printer driver.

[Explanation of symbols]

10 ... Image input device 20 ... Image processing device 21 ... Computer 23 ... Keyboard 30 ... Printing device 31-33 ... Printer

Continued front page    F-term (reference) 2C056 EA11 EC79 EE03                 2C262 AA02 AA24 AB17 BA09 BB03                       BC01 BC13 DA06 EA10                 5C074 BB16 DD24 DD27 FF15                 5C077 MP02 MP08 NN04 PP33 PP37                       PP39 PQ12 PQ22 TT05                 5C079 HB03 KA12 LA24 LB01 MA01                       MA11 PA03

Claims (5)

[Claims] 1. Use of a recording material for a printing device, wherein a recording material for each element color is attached to a recording medium in a dot matrix form in order to print out a color image with a plurality of element colors based on print data. A print data correction device that corrects the print data in order to compensate for a color change based on a bias in the amount, and is based on a predetermined correction amount that compensates for the bias in the usage amount of the recording material set for each element color. Print data comprising: a correction unit that corrects the print data according to the present invention; and a correction amount reduction unit that reduces the correction amount by the correction unit when a color mixture is realized by combining each element color as compared with a single color. Correction device. 2. The print data correction device according to claim 1, wherein the correction amount reducing means further reduces the correction amount as the number of colors to be mixed increases. 3. The print data correction device according to claim 1 or 2, wherein the correction amount reduction means stores an optimal reduction amount according to the number of colors to be mixed. And a reduction amount weighting addition means for adding up the reduction amounts by weighting corresponding to the number of pixels, as well as summing up the number of colors to be mixed in each pixel. 4. Use of a recording material for a printing device, wherein a recording material for each element color is attached to a recording medium in a dot matrix form in order to print out a color image with a plurality of element colors based on print data. A print data correction method for correcting the print data in order to compensate for the color change based on the bias of the amount, wherein a predetermined correction amount for compensating the bias of the use amount of the recording material is set for each element color. In addition, a print data correction method is characterized in that when the color is realized by combining each element color, the same correction amount is reduced as compared with the case of a single color to correct the print data. 5. The same recording by a computer to a printing device for adhering a recording material for each element color to a recording medium in a dot matrix form in order to print out a color image with a plurality of element colors based on print data. A software recording medium that records a print data correction program that corrects the print data in order to compensate for the color change based on the uneven usage amount of the material, and compensates the uneven usage amount of the recording material for each element color. The print data correction program is characterized in that a predetermined correction amount to be set is set, and when the color mixture is realized by combining each element color, the correction amount is corrected to be smaller than that for a single color and the print data is corrected. Software recording medium.