JP2005254548A - Printing controller, printing controlling method and printing control program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve an image quality of printing images by reducing a color shift of the printing images due to a bias of a color material concentration brought about in an accommodation chamber of an ink cartridge. <P>SOLUTION: Ink information D1 showing a quantity of ink in an ink accommodation chamber 40 is acquired. According to a corresponding relation between the quantity of ink in the ink accommodation chamber 40 and information showing a change of the color material concentration of ink sent from the ink accommodation chamber 40 to printing heads 29a-29f, the change of the color material concentration of ink sent from the ink accommodation chamber 40 to the printing heads 29a-29f is estimated from the ink information D1. On the basis of the estimated change of the color material concentration, printing data D4 is corrected to lessen a difference of the color material concentration of ink sent from the ink accommodation chamber 40 to the printing heads 29a-29f. Control of making a printer (printing apparatus) 20 print the printing image I1 corresponding to printing data D5 after the correction is carried out. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a print control apparatus, a print control method, and a print control program that perform printing by discharging ink stored in a storage chamber of an ink cartridge from a print head.

  2. Description of the Related Art Printing apparatuses such as ink jet printers print a print image corresponding to print data by ejecting a liquid ink liquid contained in a storage chamber of an ink cartridge from a print head. As the ink liquid, in addition to a dye ink in which a colorant composed of a dye is mixed, a pigment ink in which a color material composed of a pigment is mixed is also used.

In the ink jet recording apparatus disclosed in Patent Document 1, a plurality of test patterns are recorded from a plurality of types of density change characteristic tables for predicting the density change of the dye ink corresponding to the “continuous non-ejection time”. One of the density change characteristic tables is selected based on the density, and binary data indicating ink ejection or non-ejection from the head corresponding to each ink density is determined with reference to the selected density change characteristic table. Has been described. This is because immediately after fresh ink is supplied into the nozzle, the solvent that forms the ink gradually evaporates from the nozzle tip, and the ink density at the nozzle tip increases with time. Yes (paragraph 0013, FIG. 7). FIG. 7 of the same document is a graph showing an example of the density increase rate with respect to the “continuous non-ejection time” of ink, and this “continuous non-ejection time” is after ink is ejected from one nozzle of the inkjet head unit. Next, it is the time until ink is ejected from the nozzle (paragraphs 0053 to 0054).
JP 2001-145999 A

When pigment ink is used as the ink, the color material density of the ink may be biased in the ink cartridge storage chamber due to the passage of time after the ink cartridge is mounted on the printing apparatus, and the color shift may occur in the printed image. . Therefore, there was a desire to reduce such color misregistration.
The apparatus disclosed in Patent Document 1 uses dye ink (paragraph 0020 of the same document) and predicts the colorant concentration of the ink at the nozzle tip of the print head, but the ink cartridge housing chamber. Therefore, it is not possible to reduce the color misregistration of the printed image due to the uneven colorant concentration.

  SUMMARY An advantage of some aspects of the invention is that it provides a print control apparatus, a print control method, and a print control program capable of improving the image quality of a print image.

Means for Solving the Problems and Effects of the Invention

In order to achieve the above object, the present invention performs print control on a printing apparatus that prints a print image corresponding to print data by ejecting ink stored in a storage chamber of a mounted ink cartridge from a print head. A print control apparatus comprising an ink information acquisition unit, a prediction unit, and a print control unit.
Ink information representing the amount of ink in the storage chamber is acquired by the ink information acquisition means. Here, a correspondence relationship is provided between the amount of ink in the storage chamber and information representing a change in the color material concentration of ink sent from the storage chamber to the print head. From the ink information is predicted according to the corresponding relationship from the ink information. Then, the print data is corrected by the print control means so that the deviation of the color material density of the ink sent from the storage chamber to the print head is reduced based on the predicted change in the color material density. Control is performed to cause the printing apparatus to print a print image corresponding to the data. Then, the printing apparatus prints a print image in which the color shift due to the color material density shift of the ink sent from the storage chamber to the print head is reduced. Therefore, it is possible to obtain a print image with little color misregistration and improve the image quality of the print image.

The ink can be a liquid ink, but it may be powdered. In addition to pigments, the coloring material includes coloring agents such as dyes.
The amount of ink in the storage chamber may be the amount of ink consumed in the storage chamber, the remaining amount of ink in the storage chamber, or the like. The ink consumption amount and remaining amount may be the number of ink dots, ink weight, ink volume, and the like.
The color material density of the ink can be the amount of color material per unit amount of ink. The ink unit amount may be a unit volume of ink, a unit weight of ink, a number of ink unit dots, and the like. The amount of the color material may be the weight of the color material, the volume of the color material, or the like.
The information representing the change in the color material density may be an estimated color material density of ink, its relative amount, an estimated shift amount of ink color material density, its relative amount, and the like.
The prediction of the change in the color material density may be obtained by acquiring the predicted color material density (or the relative amount) of the ink, acquiring the predicted shift amount (or the relative amount) of the ink color material concentration, or the like. .

The color material density deviation can be a deviation from the reference color material density as a reference. Here, if the reference color material density is the color material density when the gradient of the color material density is not generated in the unused ink in the reference ink cartridge, the image quality of the printed image can be improved more reliably. It becomes possible. Of course, a color material density other than such a color material density can be used as the reference color material density.
Various data can be considered as the print data. For example, the print data may be data expressing the image with gradation data for each pixel. The number of pixels may be any number as long as it can represent an image, and may have a configuration of a plurality of pixels, and may represent a small image such as 4 × 4 pixels or 8 × 8 pixels.

  The prediction means refers to correspondence data representing a correspondence relationship between the amount of ink in the storage chamber and the information indicating the change in the color material concentration, and determines the color material concentration of ink sent from the storage chamber to the print head. Changes may be predicted from ink information. With the simple configuration of using the correspondence data, it is possible to reliably improve the quality of the printed image.

  The print control means may correct the print data so as to compensate for a deviation in color material density of ink sent from the storage chamber to the print head. Since the print data is corrected so that the deviation of the color material density of the ink supplied to the print head is compensated, the image quality of the print image can be further improved.

  The correspondence relationship is a correspondence relationship according to an elapsed time after the ink cartridge is mounted on the printing apparatus, and an elapsed time acquisition unit that acquires an elapsed time since the ink cartridge is mounted on the printing apparatus. And the prediction means predicts a change in the color material density of the ink sent from the storage chamber to the print head from the ink information in accordance with the correspondence relationship corresponding to the elapsed time among the correspondence relationships. It is good. When the gradient of the colorant density of the ink gradually occurs according to the position in the vertical direction in the storage chamber, it is possible to improve the image quality of the printed image more reliably and accurately.

Also, correspondence data representing the correspondence between the amount of ink in the storage chamber and the information representing the change in the color material density is stored according to the elapsed time, and the change in the color material density of the ink predicted previously is stored. Based on the ink information and the amount of the same color material, a change in the color material density of the ink sent from the storage chamber to the print head is obtained based on the ink cartridge installed in the printing apparatus. May be. Since the change in the color material density is predicted in consideration of the amount of the color material of the ink sent out from the storage chamber after the ink cartridge is mounted, the image quality of the printed image can be improved more reliably and accurately.
The method for obtaining the color material amount is to sum the amount obtained by multiplying the ink discharge amount by the predicted color material concentration, and to integrate the formula for obtaining the predicted color material concentration from the ink discharge amount with the ink discharge amount. , Etc. are conceivable.

The correspondence data is used as data representing the relative amount of the color material concentration of the ink corresponding to the position in the vertical direction in the storage chamber, and the amount representing the color material amount of the ink remaining in the storage chamber is obtained. The relative amount of the color material density at the flowing-out position may be acquired, and the change in the color material concentration of the ink sent from the storage chamber to the print head may be predicted from the amount representing the obtained color material amount and the same relative amount. . It is possible to predict changes in the color material concentration of ink flowing out of the storage chamber with ink cartridges of various shapes, and to reliably determine the amount representing the color material amount of the remaining ink. Since it is possible to reliably predict a change in the color material density of the ink from the expressed amount, it is possible to improve the image quality of the printed image more reliably and accurately.
The amount representing the obtained color material amount may be the color material amount itself of the remaining ink, the average color material concentration of the remaining ink, or the like.

  The ink is a liquid pigment ink, the position where the ink flows out from the storage chamber is the bottom of the storage chamber, and the correspondence data is data representing the relative amount of the colorant concentration of the ink in the bottom of the storage chamber. The average color material density of the ink remaining in the storage chamber is obtained, the relative amount of the color material density in the lowermost part of the storage chamber is obtained, and the average color material density is multiplied by the average color material density, thereby predicting the color material for the ink It is good also as a density | concentration. Since only the relative amount of the color material density in the lowermost part of the storage chamber needs to be used as the correspondence data, the data amount of the correspondence data can be reduced, and the average color material concentration can be reliably obtained with a simple configuration. Since the change in the ink color material density can be reliably predicted from the average color material density, the image quality of the printed image can be improved more reliably and accurately.

The apparatus described above includes various aspects such as being implemented together with other methods in a state of being incorporated in a certain device. For example, the present invention can be applied as a printing system including a printing apparatus. In addition, since it is possible to proceed with processing according to a predetermined procedure corresponding to the configuration of the print control apparatus, the present invention can also be applied as a control method. , Have an effect. Further, since the control program may be executed by the above apparatus, it can be applied to the program described in claim 7 or a computer-readable recording medium on which the program is recorded, and has the same operations and effects. .
Of course, the configurations described in claims 2 to 5 can be made to correspond to the print control apparatus, the print system, the print control method, the program, and the recording medium.

Hereinafter, embodiments of the present invention will be described in the following order.
(1) Configuration of printing system:
(2) Correspondence data creation method and color material density prediction method:
(3) Print control processing:
(4) Modification:

(1) Configuration of printing system:
FIG. 1 is a diagram schematically showing a configuration of a print control apparatus U0 according to an embodiment of the present invention. FIG. 2 is a personal computer (PC) 10 serving as a print control apparatus of the present invention in this embodiment. 1 shows a printing system including an inkjet printer 20 that can perform color printing (printing means). Of course, the computer used in the present invention is not limited to a PC.
The print control device is a device that controls the printer so as to reduce color misregistration of a print image derived from a gradient of color material density generated according to a vertical position due to a sedimentation component in ink in a storage chamber of an ink cartridge. Has been. More specifically, the ink consumption is measured, the ink color material density that changes as the ink is consumed is corrected by increasing or decreasing the ink discharge amount (dot density), and the printer is caused to execute printing.

  In the PC 10, the CPU 11, the ROM 12, the print data D4 before correction, the print data D5 after correction, information such as the average color material density 13a, the predicted color material density 13b, and the like are stored in the bus 10a, the CD-ROM drive 15, A clock circuit 16 and interfaces (I / F) 17a to 17e are connected, and a hard disk (HD) 14 that is a magnetic disk is also connected via a hard disk drive, and the CPU 11 controls the entire PC.

  The HD 14 stores an operating system (OS), an application program (APL), and the like, and is appropriately transferred to the RAM 13 and executed by the CPU 11 at the time of execution. The HD 14 is a print control program of the present invention, ink information D1, correspondence data D2, predicted color material density change information D3, a reference color material density 14a as a reference, a count value 14b representing the number of dot ejections, mounting date and time information 14c, Cumulative color material amount 14d sent out from the ink storage chamber, a plurality of color correction data converted into a one-dimensional LUT, a color conversion LUT (color conversion table), a dot distribution table (dot type correspondence data), various threshold values, etc. It is a predetermined storage area for storing information. A digital camera 50 or the like can be connected to the I / F 17a (for example, USB I / F). A display 18a for displaying an image corresponding to the data based on color image data is connected to the CRTI / F 17b. A keyboard 18b and a mouse 18c are connected to the input I / F 17c as operation input devices, and a printer I / F 17e. Is connected to the printer 20 via a cable (for example, a serial I / F cable).

The printer 20 ejects six colors of ink filled in six ink cartridges 40 respectively corresponding to each color of CMYRVK (cyan, magenta, yellow, red, violet, black) from the print head, A print image corresponding to print data representing a color image is printed by forming dots by attaching ink to print paper (print medium). Of course, a printer that uses light cyan, light magenta, light black, dark yellow, non-colored ink, or the like may be employed, or a printer that does not use any of CMYRVK inks may be employed. Various printing apparatuses such as a bubble printer that generates bubbles in the ink passage and discharges the ink and a laser printer that prints a print image on a print medium using toner ink can be employed. Each ink in the present embodiment is a pigment ink, and is a liquid ink liquid in which a color material composed of a fine pigment is mixed in an aqueous solvent. The ink to which the present invention can be applied is only required to have fluidity, and may be a dye ink composed of an ink liquid in which a colorant composed of a dye is mixed, an ink liquid using an oil-based solvent, a powdered ink, or the like. As the print medium, various print media such as glossy paper such as photo paper, plain paper that is less glossy than glossy paper, and the like can be used.
In the printer 20, a CPU 21, a ROM 22, a RAM 23, a communication I / O 24, a control IC 25, an ASIC 26, an I / F 27, and the like are connected via a bus 20 a, and the CPU 21 controls each unit according to a program written in the ROM 22.

  A carriage that reciprocates in the main scanning direction by the carriage mechanism 27a is provided with a cartridge holder 32 on which each ink cartridge 40 can be mounted at a predetermined mounting location, and a print head unit (print head assembly). 29 is mounted. In the holder 32 of the present embodiment, six mounting locations corresponding to each of all six types of ink are formed. When each cartridge 40 is mounted on the holder 32, the ink color material in the ink storage chamber (storage chamber) 41 is made uniform and the color material density is made uniform. It is designed to be mounted on the holder.

FIG. 3 shows a vertical cross section of the ink cartridge 40. Each ink cartridge 40 includes a storage chamber 41 that stores ink, and an ink outlet 41 a that is opened and closed by a valve 42 is formed at the lowermost portion of the storage chamber 41. The ink outlet 41 a passes through the ink outside the ink cartridge. An ink passage 43 extending downward to the passage 40b is formed. The horizontal cross section of the storage chamber 41 has the same shape regardless of the position in the vertical direction. Accordingly, the volume (remaining amount) of the ink stored in the storage chamber 41 is proportional to the distance (ink depth) from the lower surface of the storage chamber 41 to the upper surface of the ink.
A valve 42 is provided at a lower portion of the side wall of the storage chamber 41. When ink is not ejected from the print heads 29a to 29f, the valve 42 is closed as shown on the left side of the drawing. When ink discharge is started from the print head, a negative pressure is applied to the valve 42 from the print head, so that the valve 42 is opened as shown on the right side of FIG. Then, ink is sent from the storage chamber 41 to the print heads 29a to 29f, and the ink is supplied to the print heads 29a to 29f. At the end of printing, negative pressure is not applied to the valve 42. As a result, the valve 42 is automatically closed as shown on the left side of the drawing, and ink is not sent out from the storage chamber 41.

The print head unit 29 includes print heads 29a to 29f and a nonvolatile semiconductor memory 31 provided for each of six types of CMYRVK inks. The print cartridges 29a to 29f assembled to the printer and the corresponding ink cartridge 40 are connected to each other through different ink passages 40b. Each of the print heads 29a to 29f is supplied with ink of the corresponding color from the corresponding ink cartridge storage chamber 41 via the ink passages 43 and 40b, and can eject the ink to adhere to the printing paper. is there. The printer 20 uses the print heads 29a to 29f corresponding to each ink type to form dots on the printing paper and print a print image.
Each cartridge 40 is provided with a nonvolatile semiconductor memory 40a, and each memory 40a is electrically connected to the control IC 25. The memory 40a can be a rewritable memory such as an EEPROM. Although each cartridge 40 of the present embodiment is assumed to have the same shape and each mounting position of the holder 32 is also assumed to have the same shape, each ink cartridge and the holder may be different from each other.

The communication I / O 24 is connected to the printer I / F 17e of the PC 10, and the printer 20 receives raster data for each color transmitted from the PC 10 via the communication I / O 24. The ASIC 26 outputs applied voltage data corresponding to the raster data to the head driving unit 26a while transmitting / receiving a predetermined signal to / from the CPU 21. The head drive unit 26a generates an applied voltage pattern to the piezo elements incorporated in the print heads 29a to 29f from the applied voltage data, and each ink stored in the storage chamber 41 is transferred from the corresponding print heads 29a to 29f. Discharge in units of dots. The carriage mechanism 27a and the paper feed mechanism 27b connected to the I / F 27 cause the print head unit 29 to perform main scanning, and sequentially feed print sheets while performing a page break operation as appropriate, thereby performing sub-scanning.
Further, when the printer 20 detects that the memory 40a is not electrically connected to the control IC 25, the printer 20 determines that the corresponding ink cartridge 40 is not attached to the holder 32, and informs the communication I / O 24 of the information to that effect. To the PC 10. Further, when the printer 20 detects that the memory 40a is electrically connected from the state where it is not electrically connected to the control IC 25, the printer 20 determines that the corresponding ink cartridge 40 is attached to the holder 32, and information to that effect. Is output to the PC 10 via the communication I / O 24. In the PC 10, when information indicating that the ink cartridge is mounted is input, the current date and time is acquired from the clock circuit 16 that measures the date and time, and the date and time information indicating the date and time t _start when the ink cartridge is mounted. 14c is stored in the HD 14. Also, the count value 14b of the counter representing the number of ink dots ejected (ink consumption) is reset, and the accumulated color material amount 14d is also reset. Thereafter, the count value 14b of the counter is updated when the printer ejects ink dots until information indicating that the ink cartridge is not installed is input, and the ink is sent out from the ink storage chamber based on the predicted color material density. The accumulated color material amount 14d stored in the HD 14 is updated.

The print heads 29a to 29f are provided with a plurality of inkjet nozzles for each color, and piezo elements are arranged corresponding to the respective nozzles.
As shown in FIG. 4, the piezo element PE installed at a position in contact with the ink passage 40b that guides the ink to the nozzle Nz expands when a voltage is applied between the electrodes provided at both ends of the element, and the ink passage One side wall of 40b is deformed. Then, the ink corresponding to the contraction of the ink passage 40b is ejected from the tip of the nozzle Nz as an ink droplet Ip, soaks into the printing medium, and dots are formed to perform printing. And the dot becomes large, so that the voltage difference of the drive waveform of an applied voltage is large.
The printer 20 can form three types of dots having large, medium, and small ink amounts (for example, ink weight or ink volume) on a print medium, and inks having different levels of ink amounts from the same print head for each color. Are ejected to form dots having a size corresponding to the amount of ink in the plurality of stages. Identification information for identifying the three types (predetermined number) of dot types is added to the raster data transmitted from the PC to the printer, and the printer forms the types of dots corresponding to the identification information. When raster data composed of dot data representing the type of dot is input for each raster, the printer forms a plurality of types of dots having different ink amounts on the print medium in accordance with the raster data.

In the PC 10, a printer driver and the like for controlling the printer I / F 17e are incorporated in the OS, and various controls are executed. APL exchanges data with hardware via the OS. The printer driver is operated when the APL printing function is executed, and can perform bidirectional communication with the printer 20 via the printer I / F 17e. The printer driver receives print data from the APL via the OS and converts it into raster data. The data is converted and sent to the printer 20.
The print control program of the present invention may be configured by any of OS, APL, OS and APL. The medium on which these programs are recorded may be a CD-ROM 15a, a flexible disk, a semiconductor memory, etc. in addition to the HD. Further, the communication I / F 17d may be connected to the Internet network, and the program of the present invention may be downloaded from a predetermined server and executed.

  The printing control apparatus U0 shown in FIG. 1 includes an HD (predetermined storage area) 14 storing correspondence data D2 and the like, and means U1 to U3. The ink information acquisition unit U1 acquires ink information D1 indicating the amount of ink in the storage chamber 41. In this embodiment, for each ink, the number of small dots Ns, medium dots Nm, and large dots Nl of ink ejected (consumed) after the cartridge 40 is mounted on the holder 32 is counted to determine the HD 14 (the cartridge 40 Memory 40a is also possible). Accordingly, the number of dots in terms of large dots NL = N1 + A1 · Nm + A2 · Ns (A1 and A2 are predetermined coefficients, 1 <A1 <A2) is calculated and used as ink information. Of course, the ink weight obtained by multiplying the number of dots equivalent to the remaining amount of ink by subtracting the number of ejected dots from the number of dots equivalent to the full amount in the ink chamber, and the number of dots (equivalent to consumption or equivalent to the remaining amount) by the weight per dot. Ink information obtained by multiplying the number of dots by the volume per dot, Ns, Nm, and Nl itself may be used as the ink information.

  The predicting unit U2 generates correspondence data D2 representing the correspondence between the amount of ink in the storage chamber 41 and information representing changes in the color material density of the ink sent from the storage chamber 41 to the print heads 29a to 29f. Referring to this, a change in the color material density of the ink sent from the storage chamber 41 to the print heads 29a to 29f is predicted, and predicted color material density change information D3 representing the change in the predicted color material density is generated. In the present embodiment, the color material weight (for example, g / ml) per unit volume of ink is used as the color material concentration. However, the unit weight of ink, the volume of color material per unit dot, and the like may be used as the color material concentration. Good. The information representing the change in the ink color material density is the relative amount of the predicted color material density of the ink, but the absolute amount of the predicted color material density and the predicted shift amount of the ink color material density (absolute amount or relative amount). ) Etc. Then, the predicted color material density change information D3 in which the predicted color material density of the ink is generated is used to predict a change in the ink color material density, but the predicted color material density (absolute amount) of the ink is calculated. In addition to acquisition, prediction may be performed by acquiring a relative amount of the predicted color material density, or prediction may be performed by acquiring an estimated deviation amount (absolute amount or relative amount) of ink color material concentration. Also good.

  The print control unit U3 corrects the print data D4 before correction so as to reduce the deviation of the color material density of the ink sent from the storage chamber 41 to the print heads 29a to 29f based on the predicted change in the color material density. Then, control is performed to cause the printer 20 to print a print image corresponding to the corrected print data D5. Since the predicted color material density change information D3 is generated by the prediction means U2, the print data is corrected so as to compensate for the color material density shift with reference to the information D3. In the present embodiment, the deviation from the reference color material density is compensated by using the color material density when the color ink density is not biased as the reference ink cartridge as the reference color material density. . Then, the printer 20 prints on the print medium M1 the print image I1 in which the color misregistration is compensated so as to be the ink color having the reference color material density.

(2) Correspondence data creation method and color material density prediction method:
By the way, the ink precipitation component gradually settles in the ink containing chamber, and the colorant density of the ink may be biased. Of course, the floating component of the ink gradually rises, and the colorant density of the ink may be biased. In the case of a dye ink using a dye as a colorant, such a color material density deviation is relatively small. However, a pigment ink tends to have a relatively large color material density deviation compared to the dye ink.
In view of this, in the present embodiment, in consideration of the use of pigment ink in particular, correspondence data representing the correspondence corresponding to the elapsed time since the ink cartridge was mounted in the cartridge holder of the printer is prepared, and the elapsed time The change in the ink color material density is predicted according to the corresponding relationship. Hereinafter, an example of a method for creating correspondence data will be described.

FIG. 5 shows an ink color material density C (the above-mentioned cyan color) corresponding to the distance D in the vertical direction in the storage chamber as time passes after the ink cartridge is mounted in a state where a certain ink (any of the CMYRVK inks) is not used. Is different). Here, the distance D is a distance (unit: mm, for example) from the lower surface of the storage chamber in a state where the ink cartridge is mounted on the printer, and is proportional to the ink remaining amount. Each graph shows the correspondence between the color material density C (unit: g / ml, for example) and the distance D at the time of elapsed time t = 0, t _i1 , t _i2 , t _s (unit: hr) Is shown. The elapsed time t _s indicates the time when the gradient of the color material concentration in the accommodation chamber can be regarded as a steady state. Since the ink cartridge is designed to be shaken when mounted, it is assumed that the color material of the ink in the storage chamber is uniform at this point.
As shown in the figure, when t = 0, the color material concentration in all 0 (lower limit position) to D _u (upper limit position) is a C0. This C0 is the average color material concentration of the ink in the storage chamber in the ink cartridge that does not use ink. In the present embodiment, the color material density C0 for the reference ink cartridge is set as the reference color material density 14a. As time elapses after the ink cartridge is mounted, a gradient of the color material density gradually occurs with respect to the distance D (vertical position), and eventually becomes a steady state. In the case of the pigment ink of the present embodiment, since the specific gravity of the pigment is larger than that of the solvent (for example, water), the pigment is precipitated. As shown in _{FIG., T = 0, t i1,} t i2, t colorant concentration at the bottom (distance D = 0) in _s the C0 <Cl1 <Cl2 <Cls, and the top (distance D = Du) The color material density at C0>Cu1>Cu2> Cus.

FIG. 6 shows the structure of correspondence data for a certain ink. When the correspondence data is created from the correspondence between the distance D and the color material density C described above, the correspondence changes according to the elapsed time t. Therefore, the correspondence data includes the elapsed time t _i (i is 0 to 0). s is an integer, and s is a positive integer). Corresponding relationship data D21 shown in the figure indicates that each color material density at time t _{i and} each distance D _p from the lower surface in the ink containing chamber (p is an integer of 0 to u, u is an integer of 1 or more) is t = 0. The information table stores the relative amount Ri (D _p ) of the color material density divided by the color material density C0. The relative amounts are information representing changes in the color material density of ink sent from the ink storage chamber to the print head. Further, as the distance D increases, the ink remaining amount Nr in the accommodation chamber increases, and the distance D and the remaining amount Nr correspond to each other at 1: 1. That is, for each color, the correspondence relationship data D21 includes the amount of ink in the ink storage chamber and the relative amount R of the color material density according to the vertical position of the ink cartridge mounted on the printer in the storage chamber (the above red and red). Are different from each other), and are data representing the corresponding relationship according to the elapsed time t.

Here, when the position where the ink flows out from the storage chamber is fixed, the relative amount Ri of the color material density at the position (distance Dp) where the ink flows out from the upper correspondence data D21 as shown in the middle of the figure. (Dp) may be extracted as correspondence data D22. Then, the data amount of the correspondence data is reduced, and the storage capacity of the correspondence data can be reduced. The correspondence relationship data D22 is an information table representing the relative amount of the color material density at a predetermined position (distance Dp) in the storage chamber of the ink cartridge mounted on the printer for each color.
In the ink cartridge of the present embodiment, since ink flows out from the lowermost part of the ink storage chamber, as shown in the lower part of the drawing, the relative amount Ri of the color material density at the position (distance D = 0) at the lowermost part of the storage chamber. (0) is extracted as correspondence data D23 in the information table format. Then, the correspondence data D23 having a small data amount for each color is stored in the HD (storage area) to reduce the storage capacity of the correspondence data.
The correspondence data and the data (ID) representing the correspondence described above are recorded in the memory 40a of the corresponding color ink cartridge, and the correspondence data and the data representing the correspondence are read from the memory 40a. Good. Of course, instead of the memory 40a, the correspondence data or the data indicating the correspondence may be recorded and read out as appropriate in the ROM 22 of the printer or the memory 31 of the print head unit.

FIG. 7 shows a state in which a change in the color material density of ink sent from the ink storage chamber to the print head is predicted. The upper part of the figure shows an example of the correspondence relationship between the elapsed time t defined in the correspondence relationship data and the relative amount of color material density, where the horizontal axis is t (unit: hr, for example), and the vertical axis is the relative amount. is there. Specifically, the correspondence relationship between the elapsed time t defined in the correspondence relationship data D23 and the relative amount Ri (0) is shown. When the time t elapses after the ink cartridge is mounted, the relative amount R corresponding to t in the correspondence data becomes the relative amount of the color material density. Here, considering that the ink is consumed, more specifically, the relative amount 1 and the relative amount R are set such that the interval between the relative amount 1 and the relative amount R decreases as the ink consumption increases. The relative amount R is corrected so that the interval is the ratio of the remaining ink amount to the full ink amount. When the full amount of ink in the ink containing chamber is Ne, the remaining amount of ink when the ink is consumed is Nr, and the relative amount of the color material density after correction is Ri ′,
R ′ = (Nr / Ne) × (R−1) +1 (1)
The corrected relative amount is calculated by the following equation. Then, the predicted color material concentration Cf of the ink sent from the ink storage chamber to the print head can be obtained by the following arithmetic expression that multiplies the average color material concentration Ca of the ink remaining in the ink storage chamber by the relative amount R ′.
Cf = Ca × R '(2)

なる演算式により算出することができる。ただし、Nj’は、Njを形成した大ドット換算のドット数に変換した変換値であり、C’（ｎ）は送り出されたインクの色材濃度を大ドット換算のドット数ｎから求める関数である。さらに、インク収容室に残存するインクの色材量Wrは、
Wr＝C0×Ne−Wc …（５）
なる演算式により算出することができる。ここで、C0はｔ＝０でのインク（未使用インク）の平均色材濃度、Neはインクの満量である。また、インク収容室内のインクの残量をNr（＝Ne−Nj）として、
Ca＝Wr／Nr …（６）
なる演算式により、残存インクの平均色材濃度Caを算出することができる。
そこで、残存インクの平均色材濃度Caを上記演算式（２）に代入することにより、印刷ヘッドへ送られるインクの予測色材濃度Cfが求まる。 FIG. 8 shows how the average color material density Ca of the remaining ink is obtained. The upper part of the figure shows an example of the correspondence relationship between the ink consumption N and the color material density C of the ink delivered from the ink storage chamber, where the horizontal axis is N (unit: ml), and the vertical axis is C (unit). : For example g / ml). When the ink consumption amount in the ink storage chamber is Nj, the color material amount Wc sent out from the storage chamber is C (N), where C (N) is a function for obtaining the color material density of the sent ink from the ink consumption amount N.

Can be calculated by the following equation. However, Nj ′ is a converted value converted to the number of dots converted to large dots forming Nj, and C ′ (n) is a function for obtaining the colorant density of the sent ink from the number of dots n converted to large dots. is there. Furthermore, the color material amount Wr of the ink remaining in the ink storage chamber is
Wr = C0 × Ne−Wc (5)
Can be calculated by the following equation. Here, C0 is the average color material density of ink (unused ink) at t = 0, and Ne is the full amount of ink. Further, the remaining amount of ink in the ink containing chamber is Nr (= Ne−Nj),
Ca = Wr / Nr (6)
The average color material concentration Ca of the remaining ink can be calculated by the following arithmetic expression.
Therefore, the predicted color material density Cf of the ink sent to the print head is obtained by substituting the average color material density Ca of the remaining ink into the arithmetic expression (2).

In this way, when there is a gradual deviation in the ink color material concentration depending on the position in the vertical direction in the ink storage chamber, the change in the color material concentration of the ink sent out from the storage chamber is reliably and accurately predicted. Therefore, it is possible to sufficiently compensate for the color shift of the printed image.
In addition, since the color material density deviation may vary depending on the type of ink, the above-described correspondence is prepared for each ink color, so that the deviation of the color material density of the ink is accurately compensated.
Although there is a technique for correcting the density that increases due to evaporation of ink present at the nozzle tip of the print head (Japanese Patent Laid-Open No. 2001-145999), in this technique, the ink is sent (supplied) from the ink storage chamber. The density correction is not performed for the ink. Therefore, when using an ink that tends to cause uneven color material concentration in the ink containing chamber, such as pigment ink, in the same technology, the uneven color material concentration directly becomes an error in color development of the printed image, which affects the image quality of the printed image. It will come out. If the present invention is applied, such a color error can be suppressed, so that the present print control apparatus is very useful.

(3) Print control processing:
FIG. 9 and FIG. 10 are flowcharts showing processing for correcting print data using correspondence data and performing print control based on the corrected print data. FIG. 11 is a diagram schematically showing the processing. FIG. 12 is a diagram schematically showing the structure of a plurality of color correction data 14e stored in the HD 14. As shown in FIG. The color correction data 14e is stored in the HD corresponding to the shift amount at each stage of the shift amount of the color material density. In this embodiment, the PC that performs the processing of FIGS. 9 and 10 constitutes a print control apparatus, S205, S135, and S150 are ink information acquisition means, S210 to S215 are elapsed time acquisition means, and S220 to S245, S140, and S155. Corresponds to the prediction means, and S250, S120 to S130, and S145 correspond to the print control means.
First, the PC 10 inputs image data D11 in which a gradation is expressed by a large number (predetermined number) of pixels in a dot matrix and an image is expressed by gradation data corresponding to a plurality of element colors for each pixel. For example, the data is converted into RGB data of 256 gradations for each of RGB in a wide RGB color space expressed by gradation by a plurality of pixels for each RGB (step S105; hereinafter, “step” is omitted). The RGB data is print data representing an image with a plurality of element colors RGB.

  Next, gradation data of each pixel constituting the RGB data is converted, and the RGB data is expressed in gradation by the same number of pixels for each CMYRVK with reference to the color conversion LUT stored in the HD 14. Color conversion is performed to the CMYRVK data D12 that has been performed (S110). The color conversion LUT is an information table that defines the correspondence between the RGB data and the CMYRVK data for a plurality of reference points. When CMYRVK data that matches the input RGB data is not stored in the color conversion LUT, CMYRVK data corresponding to a plurality of RGB data close to the input RGB data is acquired, and RGB data is obtained by interpolation such as volume interpolation. To CMYRVK data corresponding to. The CMYRVK data is print data in which an image is expressed in gradation by a large number (predetermined number) of pixels in the form of a dot matrix similar to RGB data. It is assumed that CMYRVK data representing 256 ink usage amounts is 256 gradations.

  Thereafter, the color material density prediction process of FIG. 10 is started (S115), and ink information D1 in which the ink consumption amount in the ink containing chamber is represented by the number of dots NL in terms of large dots is acquired (S205). When the PC 10 inputs information indicating that the ink cartridge is mounted from the printer, the PC 10 resets the count value 14b of each counter indicating the number of small, medium, and large dots ejected in the corresponding color ink. The number of small dots, medium dots, and large dots formed in S135 is counted for each color, and the number of small, medium, and large dots counted this time in S150 is added to the corresponding counter, and the number of small dots Ns in HD 14 is set. And the number of medium dots Nm and the number of large dots Nl. Therefore, the dot number NL = Nl + A1 · Nm + A2 · Ns in terms of large dots is calculated from these and used as ink information. Of course, when the number of dots is counted on the printer side, the ink information may be obtained by obtaining the number of dots from the printer.

Next, HD 14 is acquired as mounting date / time information 14c indicating the date / time when each ink cartridge was mounted (S210). Further, the current date and time t _now is obtained from the clock circuit 16, and the elapsed time t is obtained by subtracting the date and time t _start represented by the mounting date and time information 14c from the date and time t _now (S215).

Thereafter, the target colors to be compensated for color misregistration are set from among all six colors (S220). For example, a different numerical value may be associated with each color of ink, and a target color may be set by sequentially updating a pointer value storing the numerical value. Next, the relative amount R of the color material density corresponding to the elapsed time t is referred to by referring to the correspondence data corresponding to the set color among the correspondence data set for each color of CMYRVK for the set color ink. Is acquired (S225). Here, if the elapsed time t is defined as a reference point in the correspondence data, the corresponding relative amount R is acquired as it is, and if it is not defined, a plurality of elapsed times t _i , t _{i + 1} close to the elapsed time t are obtained. The relative amounts R _i and R _{i + 1} corresponding to (t _i <t <t _{i + 1} ) are obtained, and R _i + (R _{i + 1} −R _i ) × (t−t _i ) / ( The relative amount R corresponding to the elapsed time t is converted by an interpolation operation such as linear interpolation such as t _{i + 1} −t _i ).
Further, using the above equation (1), the relative amount R is corrected to R ′ based on the ratio Nr / Ne of the remaining ink amount to the full ink amount (S230). The remaining ink amount Nr can be estimated by subtracting the ink consumption amount from the ink full amount Ne.

When the correction amount R ′ corresponding to the remaining amount of ink is obtained, the accumulated color material amount 14d stored in the HD 14 is read into the RAM, and the color material amount of ink sent from the ink storage chamber to the print head from the time when the ink cartridge is installed. Wc is acquired (S235). The PC 10 resets the accumulated color material amount 14d of the corresponding color when the information indicating that the ink cartridge is installed from the printer, and thereafter, for each color, the small, medium and large dots counted in S140 of FIG. The number of dots converted to a large dot is calculated from the number, the color material amount is calculated by multiplying the number of dots by the predicted color material density Cf, and the color material amount calculated this time in S155 is added to the accumulated color material amount 14d. The accumulated color material amount 14d is held in the HD 14. Therefore, the accumulated color material amount 14d is read out.
Next, using the above formulas (5) and (6), the average color material concentration Ca of the residual ink (the amount representing the color material amount of the residual ink) is calculated based on the color material amount Wc of the delivered ink. (S240). Then, using the above equation (2), based on the average color material density Ca and the corrected relative amount R ′, the predicted color material density Cf of the ink delivered from the ink storage chamber is calculated, and the predicted color material density change is calculated. Information D3 is stored in the RAM (S245).
In this manner, the amount of the color material of the ink sent out from the ink storage chamber after the ink cartridge is mounted based on the previously estimated change in the color material density of the ink is obtained, and sent from the ink storage chamber to the print head. A change in the color material density of the ink can be predicted from the ink information and the color material amount.

  Thereafter, the reference color material density 14a corresponding to the set color is read, and the deviation of the color material density of the ink delivered from the ink storage chamber is compensated based on the reference color material density (C0) and the predicted color material density Cf. In this manner, the CMYRVK data (print data) is corrected (S250). For example, assuming that the gradation value of each pixel constituting the CMYRVK data before correction is G0, and the gradation value of each pixel constituting the corrected CMYRVK data is G1, the correction is made by an equation of G1 = G0 × C0 / Cf. Later gradation values can be determined. When the calculated G1 is greater than the maximum gradation value 255, the corrected gradation value may be set to the maximum gradation value 255.

Further, the CMYRVK data may be corrected as shown in FIG. 11 using the color correction data 14e shown in FIG. For example, the predicted deviation amount VC of the color material density is calculated by an arithmetic expression VC = A3 × {(Cf / C0) −1} (A3 is a predetermined positive coefficient such as 100), and a plurality of colors stored in the HD The CMYRVK data can be corrected by specifying the color correction data closest to the calculated value VC from the correction data 14e, and reading and referring to the color correction data. Here, since the color correction data is data defining the color correction correspondence between the CMYRVK data before correction and the CMYRVK data after correction, the color correction correspondence of the CMYRVK data is specified based on the calculated value VC. It will be. Then, the gradation data of the target pixel is corrected by referring to the read color correction data while sequentially moving the target pixel with the gradation data of each pixel constituting the CMYRVK data corresponding to the set color as the conversion target. Then, the corrected CMYRVK data D13 is generated.
If the value of VC is negative, the target printer has a smaller color development degree on the print medium than the reference printer, so color correction is performed to increase the color development degree of the printed image as shown in FIG. As a whole, the data has an output tone value larger than the input tone value. Therefore, by referring to such color correction data, the gradation value of a color having a negative VC value is largely corrected as a whole. On the other hand, when the VC value is positive, the gradation data is corrected so that the gradation value is small as an overall tendency. As described above, it is possible to compensate for the color material density deviation of the ink with a simple configuration using the color correction data. In addition to the color correction table in the information table format, the color correction data may be data for performing calculations, and various data such as a calibration LUT, a calibration conversion formula, and a dot allocation table are considered. It is done.

As described above, the print data can be corrected based on the predicted change in the color material density so as to reduce the deviation of the color material density of the ink sent from the ink storage chamber to the print head.
Thereafter, it is determined whether or not all the colors have been set (S255). If the condition is not satisfied, S220 to S255 are repeated, and if the condition is satisfied, the process is terminated.

When the color material density prediction process is completed, the gradation data of each pixel constituting the CMYRVK data is converted, and the CMYRVK data after color conversion is configured by referring to the dot distribution table 14f stored in the HD 14. A dot distribution process is performed in which the gradation data for each CMYRVK color is converted into dot amount data representing a plurality of types of dot formation amounts with different ink amounts by the same type (S120).
The dot distribution table 14f is an information table that defines a correspondence relationship between input gradation data representing the amount of ink used in the printer and output gradation data representing the amount of dot formation for each type of dot. The table 14f is provided for each color, and stores output gradation values representing the dot formation amount at each gradation of the input gradation values for each dot type. In FIG. 11, the horizontal axis represents the input gradation value, and the vertical axis represents the relative value of the output gradation value, and the dot amount data of small, medium, and large dots with respect to the input gradation value is schematically shown.
In the dot distribution process, the gradation data constituting the corrected CMYRVK data D13 is allocated to a plurality of types of dot usage amounts with reference to the dot distribution table, and the dot amount data D16 to D18 for small, medium and large dots are allocated. Generate. Similar to the CMYRVK data, these dot amount data are also data in which an image is expressed in gradation by a large number (predetermined number) of pixels in the form of a dot matrix. It is assumed that the CMYRVK 256-level data representing the ink usage of dots is used.

Thereafter, predetermined halftone processing such as an error diffusion method, a dither method, and a density pattern method is performed on the dot amount data for each dot size, and each halftone for each CMYRVK and each dot type has the same number of pixels as the CMYRVK data. Data is generated (S125). The halftone data is data representing the dot formation status as the presence / absence of dot formation. For example, the gradation value “1” is binarized by corresponding to dot formation and the gradation value “0” corresponding to no dot formation. Two-level binary data can be obtained. Of course, it is good also as data of 4 gradations.
Further, predetermined rasterization processing is performed on the generated halftone data and rearranged in the order used by the printer to generate raster data for each CMYRVK (S130).

After the raster data is generated, the number of small dots Fs, the number of medium dots Fm, and the number of large dots Fl formed for each color are counted based on the raster data (S135). Next, for each color, calculate the dot number FL in terms of large dots from the counted small, medium, and large dot numbers Fs, Fm, and Fl, and multiply the dot number FL by the predicted color material density Cf to obtain the color material amount FW. Calculate (S140). Thereafter, the raster data is output to the printer 20 (S145). After the raster data output is completed, the small, medium and large dot numbers Fs, Fm, Fl counted in S135 are added to the corresponding counters, and the count value 14b stored in the HD is attached to the ink cartridge. Thereafter, the number of dots of ink ejected is updated (S150). Then, the color material amount FW calculated in S140 is added to the accumulated color material amount 14d, and the accumulated color material amount 14d stored in the HD is updated to the color material amount sent out after the ink cartridge is mounted (S155). ) And end the flow.
In this way, RGB data is input to perform color conversion, CMYRVK data is corrected so as to reduce color material density deviation, and control is performed to cause the printer to print a high-quality print image after color compensation. it can. In addition to the CMYRVK data, the print data to be corrected at the time of color compensation can be dot amount data, halftone data, raster data, RGB data before color conversion, and the like.

The printer 20 obtains raster data representing an image, drives the print head based on these data, ejects ink and deposits it on the printing paper, and forms a print image corresponding to the RGB data. Since the raster data is data in which the deviation of the ink color material density is compensated for each CMYRVK, the print image is an image in which the deviation of the ink color material density is compensated. Therefore, it is possible to obtain a print image with little color misregistration and improve the image quality of the print image. At this time, since the print data is automatically corrected according to the above-described correspondence relationship, it is not necessary to perform color measurement by printing a patch according to ink consumption and performing color measurement using the obtained color measurement data. As a result, there is no need to prepare a colorimeter or measure the color of a patch.
Also, since the print data is finely corrected according to the elapsed time since the ink cartridge was installed, the ink color material density gradient gradually arises according to the vertical position in the ink containing chamber. In addition, the image quality of the printed image can be improved reliably and accurately. Furthermore, since the color material density change is predicted in consideration of the amount of the color material of the ink delivered from the ink storage chamber after the ink cartridge is installed, the image quality of the printed image is also improved reliably and accurately in this respect. It becomes possible to make it. In particular, the pigment ink is more likely to have a color material density gradient than the dye ink, and therefore it is preferable to apply the present invention when controlling a printing apparatus that discharges the pigment ink and prints an image on a print medium.
Furthermore, since the color material density is predicted by preparing the correspondence described above for each ink type, it is possible to accurately compensate for the color material density deviation and obtain a print image with a good image quality.

(4) Modification:
By the way, various configurations are possible for the computer and the peripheral device that can be used in carrying out the present invention. For example, the printing apparatus may be integrated with a computer. A printing apparatus that prints only a single color image may be used. A part or all of the above-described flow may be executed by a printing apparatus or a dedicated image processing apparatus.
When correcting the CMYRVK data in S250 of FIG. 10, the color conversion LUT itself may be corrected, and the CMYRVK data may be corrected with reference to the corrected color conversion LUT.

In S245 of FIG. 10, the average color material density Ca, the corrected relative amount R ′, and the reference color material density C0 are used.
VC = A3 × {Ca × R / C0−1} (7)
The predicted shift amount VC (predicted color material density change information D3) of the color material density of the ink delivered from the ink storage chamber may be calculated by the following arithmetic expression. In this case, in S250, the CMYRVK data may be corrected based on the predicted deviation amount VC so as to compensate for the color material density deviation of the ink sent from the ink storage chamber. For example, the tone value of each pixel of the CMYRVK data may be converted by referring to the color correction data closest to the predicted deviation VC from among the plurality of color correction data 14e shown in FIG.
In S240 of FIG. 10, the above-described equation (5) is used to calculate the remaining ink color material amount Wr (the amount representing the remaining ink color material amount) based on the delivered ink color material amount Wc. Also good. In this case, in S245, the predicted color material density Cf may be calculated based on the color material amount Wr and the corrected relative amount R ′ using the above equations (6) and (2).

Also, instead of correspondence data that stores the relative amount of color material density, correspondence data that stores the color material density itself (absolute amount) is prepared, and changes in color material density are predicted by referring to the correspondence data. May be.
Furthermore, with reference to the distance D _p per correspondence data storing colorant concentration of D21 (Fig. 6 top) may predict the change in the colorant concentration. Referring to the flowchart of FIG. 10, in S225, the relative amount Ri (0) of the color material density corresponding to the lowest position (D = 0) in the ink containing chamber in the correspondence data D21 is referred to. Thus, the relative amount R of the color material density corresponding to the elapsed time t can be acquired.

Furthermore, when acquiring the relative amount R of the color material density at the position where the ink flows (distance Dp), the ink is consumed rather than simply referring to the relative amount Ri (Dp) of the color material density. In consideration of the fact that the upper surface of the ink is lowered, the correction is made to increase the distance Dp as the ink consumption increases, and the relative amount Ri (Dp ′) of the color material density corresponding to the corrected distance Dp ′ is referred to. Then, it becomes possible to predict a change in the color material density more accurately. For example, if the ink full amount is Ne and the ink remaining amount is Nr,
Dp ′ = (Ne / Nr) × Dp (8)
The corrected distance Dp ′ may be calculated using the following equation. When the distance Dp ′ is larger than the upper limit Du of the distance, it means that the upper surface of the ink in the ink containing chamber is lower than the position where the ink flows out (distance Dp). There is no problem even if Dp ′ is calculated by using it. Thereby, the relative amount of the color material density at the position where the ink flows out from the ink storage chamber is acquired from the correspondence data, and is sent from the ink storage chamber to the print head from the acquired relative amount and the average color material concentration Ca. It is possible to accurately predict changes in the color material density of the ink. As a result, it is possible to improve the image quality of the printed image more reliably and accurately.

  Furthermore, when the ink cartridge in use in which ink has been consumed halfway is shaken to make the color material in the ink uniform, an operation input for a predetermined operation for confirming that the ink cartridge has been shaken is received, The date and time information representing the current date and time is acquired from the clock circuit when a predetermined operation is received, and the mounting date and time information 14c is replaced with the acquired date and time information, thereby predicting the color material density and reducing the color shift. Processing can be performed. Since the color material density in the ink is uniform in the middle, it is not affected by the error of color material density deviation due to environmental differences such as temperature, etc., so the color material density prediction accuracy is improved and more accurate Therefore, it is possible to improve the image quality of the printed image by compensating for the color shift.

Furthermore, as shown in FIGS. 13 and 14, the color material density change may be predicted without using the elapsed time t. FIG. 13 is a diagram showing the structure of the correspondence data D24, and FIG. 14 is a flowchart showing the color material density prediction process. This modification is suitable for use when the color material concentration of the ink in the ink containing chamber becomes a steady state at an early stage. In the steady state (elapsed time t = t _s ), since the gradient of the color material concentration in the storage chamber is constant regardless of the elapsed time, as shown in FIG. 13, the correspondence data D24 is the ink consumption amount in the ink storage chamber. N (amount of ink, unit: for example ml) and a predicted color material density Cf of ink delivered from the ink storage chamber (information indicating change in ink color material density, unit: for example g / ml) It is the data that represents the correspondence between

In the case where the position where the ink flows out from the ink storage chamber is at the bottom, the correspondence data D24 can be generated, for example, according to the gradient of the ink color material density in the steady state shown at the bottom in FIG. It is possible to create data in which the ink consumption and the predicted color material density are associated with each other as consumed in order from the ink. FIG. 13 shows correspondence data created in this way. When no ink is consumed, the predicted color material density is set to the lowest color material density Cls in the steady state, and all the ink is consumed. The color material density Cus at the uppermost part in the steady state is assumed as the predicted color material density at the time of being applied.
In general, an ink cartridge is mounted on a printer so that the color density of the ink is in a steady state, and is repeatedly repeated until a predetermined ink recording rate (the ratio of the number of dots formed to the total number of pixels, for example, 50%) patches (standard image) are printed on a predetermined print medium, and the contrast patches are measured in a predetermined color space (for example, CIE Lab color space) for each stage of ink consumption. By using colorimetric data such as lightness L, the ink consumption and the predicted color material density can be associated with each other as correspondence data. At that time, the reference patch having the same ink recording rate is printed from the printer on the same printing medium for the ink having the reference color material density, and the colorimetric data such as lightness L of the reference patch is used as the reference colorimetric data. If the correspondence data representing the correspondence that modifies the CMYRVK data is created so that the colorimetric data of the image is close to the reference colorimetric data (matching the color development degree of the patch), the color material density deviation is reduced. It is possible to correct the CMYRVK data and print a high-quality print image with reduced color misregistration.

When the color material density prediction process is started, ink information (the number of dots NL in terms of large dots corresponding to the ink consumption) is acquired in the same manner as in S205 (S305). Next, the target colors to be compensated for color misregistration are set from all six colors without acquiring the elapsed time t (S310). Further, for the ink of the set color, the dot number NL is converted into the ink consumption N (for example, N = NL / A4, A4 is a predetermined coefficient larger than 1), and the correspondence data D24 corresponding to the set color is referred to. Then, the predicted color material density Cf corresponding to the ink consumption N is acquired (S315). If the ink consumption N is not defined as a reference point in the correspondence data, a plurality of ink consumptions N _j and N _{j + 1} (N _j <N <N _{j + 1} ) close to the ink consumption N are obtained. Acquire corresponding colorant densities C _j and C _{j + 1} and perform linear interpolation such as C _j + (C _{j + 1} −C _j ) × (N−N _j ) / (N _{j + 1} −N _j ) Is converted into a predicted color material density Cf corresponding to the ink consumption N by an interpolation calculation such as. Then, the reference color material density 14a corresponding to the set color is read out, and based on the reference color material density and the predicted color material density Cf, CMYRVK is compensated so as to compensate for the color material density deviation of the ink delivered from the ink storage chamber. The data is corrected (S320). Thereafter, it is determined whether or not all the colors have been set (S325). If the condition is not satisfied, S310 to S325 are repeated, and if the condition is satisfied, the process is terminated.

  Also in this modification, a print image in which the deviation of the color material density of ink sent from the ink storage chamber to the print head is reduced is printed, so that the image quality of the print image can be improved. According to this modification, there is no need to perform a process of calculating the predicted color material density with reference to the time after the ink cartridge is mounted, so the print control process can be simplified and speeded up. .

FIG. 2 is a diagram schematically illustrating a configuration of a print control apparatus. 1 is a block diagram showing a configuration of a printing system. FIG. 3 is a vertical sectional view showing a vertical section of an ink cartridge. The figure which expands and shows a nozzle and its internal structure. FIG. 4 is a diagram illustrating ink color material density C according to a vertical position in an ink storage chamber. The figure which shows the structure of correspondence data typically. The figure which shows typically a mode that the change of the color material density | concentration of the ink sent out is estimated. The figure which shows typically a mode that the average color material density | concentration Ca of residual ink is calculated | required. 6 is a flowchart showing print control processing. The flowchart which shows a color material density | concentration prediction process. The figure which shows a printing control process typically. The figure which shows typically the structure of several color correction data. The figure which shows typically the structure of correspondence data in a modification. The flowchart which shows a color material density | concentration prediction process in a modification.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Personal computer (PC), 14 ... Hard disk (predetermined storage area), 14a ... Reference | standard color material density | concentration, 14b ... Count value showing the number of dot discharges, 14c ... Installation date information, 14d ... Accumulated color material amount, 14e ... Color correction data, 16 ... Clock circuit, 20 ... Inkjet printer (printing apparatus), 29 ... Print head unit, 29a-f ... Print head, 32 ... Cartridge holder, 40 ... Ink cartridge, 40a ... Memory, 40b ... Ink passage, 41 ... Ink storage chamber, 41a ... Ink outlet, 43 ... Ink passage, D1 ... Ink information, D2, D21 to D24 ... Corresponding relationship data, D3 ... Predicted color material density change information, D4 ... Print data before correction, D5 ... print data after correction, D12 ... CMYRVK data (print data) before correction, D13 ... CMY after correction VK data (print data), I1 ... print image, M1 ... print medium, U0 ... print control unit, U1 ... ink information acquisition, U2 ... prediction means, U3 ... print control unit,

Claims (7)

A print control apparatus that performs print control on a printing apparatus that prints a print image corresponding to print data by discharging ink stored in a storage chamber of a mounted ink cartridge from a print head,
Ink information acquisition means for acquiring ink information representing the amount of ink in the storage chamber;
The color material of the ink sent from the storage chamber to the print head according to the correspondence relationship between the amount of ink in the storage chamber and the information representing the change in the color material density of the ink sent from the storage chamber to the print head A predicting means for predicting a change in density from the ink information;
Based on the predicted change in the color material density, the print data is corrected so as to reduce the deviation of the color material density of the ink sent from the storage chamber to the print head, and the print corresponding to the corrected print data A printing control apparatus comprising: a printing control unit that performs control for printing an image on the printing apparatus. The correspondence is a correspondence according to an elapsed time after the ink cartridge is mounted on the printing apparatus,
And further comprising elapsed time acquisition means for acquiring an elapsed time since the ink cartridge was mounted on the printing apparatus,
The predicting means predicts a change in the color material density of ink sent from the storage chamber to the print head from the ink information in accordance with a correspondence relation corresponding to the elapsed time among the correspondence relations. Item 2. The print control apparatus according to Item 1. A storage area storing correspondence data representing the correspondence between the amount of ink in the storage chamber and the information representing the change in the colorant density according to the elapsed time;
The predicting means obtains the color material amount of the ink sent out from the storage chamber after the ink cartridge is mounted on the printing device based on the previously predicted change in the color material density of the ink, and the correspondence relationship data The change of the color material density of the ink sent from the storage chamber to the print head is predicted from the ink information and the same color material amount with reference to the correspondence data corresponding to the elapsed time from the above. The printing control apparatus according to claim 2. The correspondence data is data representing a relative amount of the ink color material density according to the position in the vertical direction of the ink cartridge mounted in the printing apparatus,
The predicting means obtains an amount representing the amount of color material of ink remaining in the storage chamber from the amount of color material of ink delivered from the storage chamber, and the color material concentration at a position where the ink flows out of the storage chamber. Is obtained from the correspondence data, and the change in the color material density of the ink sent from the storage chamber to the print head is predicted from the amount representing the obtained color material amount and the relative amount. The printing control apparatus according to claim 3. The ink is a liquid pigment ink,
The position where the ink flows out from the storage chamber is the lowermost part of the storage chamber,
The correspondence data is data representing the relative amount of the color material density of the ink in the lowermost part of the storage chamber of the ink cartridge attached to the printing apparatus,
The predicting means obtains an average color material concentration of the ink remaining in the storage chamber from the amount of the color material of the ink sent out from the storage chamber, and calculates the relative amount of the color material concentration in the lowermost portion of the storage chamber as the correspondence. Obtain from the related data and multiply the average amount by the same color material density to obtain the predicted color material density for the ink,
The print control unit compares the predicted color material density with a reference color material density for the ink, and based on the comparison result, detects a deviation in the color material density of the ink sent from the storage chamber to the print head. The print control apparatus according to claim 3, wherein the print data is corrected so as to be compensated. A print control method for performing print control on a printing apparatus that prints a print image corresponding to print data by discharging ink stored in a storage chamber of a mounted ink cartridge from a print head,
An ink information acquisition step of acquiring ink information representing the amount of ink in the storage chamber;
The color material of the ink sent from the storage chamber to the print head according to the correspondence relationship between the amount of ink in the storage chamber and the information representing the change in the color material density of the ink sent from the storage chamber to the print head A prediction step of predicting a change in density from the ink information;
Based on the predicted change in the color material density, the print data is corrected so as to reduce the deviation of the color material density of the ink sent from the storage chamber to the print head, and the print corresponding to the corrected print data A print control method comprising: a print control step for controlling the printing apparatus to print an image. A print control program for causing a computer to realize a function of performing print control on a printing apparatus that prints a print image corresponding to print data by ejecting ink stored in a storage chamber of a mounted ink cartridge from a print head. And
An ink information acquisition function for acquiring ink information representing the amount of ink in the storage chamber;
The color material of the ink sent from the storage chamber to the print head according to the correspondence relationship between the amount of ink in the storage chamber and the information representing the change in the color material density of the ink sent from the storage chamber to the print head A prediction function for predicting a change in density from the ink information;
Based on the predicted change in the color material density, the print data is corrected so as to reduce the deviation of the color material density of the ink sent from the storage chamber to the print head, and the print corresponding to the corrected print data A print control program that realizes a print control function for performing control to print an image on the printing apparatus.

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