JP4731954B2 - Inkjet recording apparatus and calibration method - Google Patents

Description

  The present invention relates to an ink jet recording apparatus such as an ink jet printer that performs recording by ejecting ink and a calibration method, and more particularly, to calibrate color balance or gray balance of an image recorded by a plurality of types of ink ejected by a recording head. This is related to calibration.

  An ink jet recording apparatus is a non-impact printer, has low noise, and can easily implement a configuration for color recording.

  When recording is performed with this ink jet recording apparatus, the gray balance differs depending on the specifications of the apparatus, and the color of the image actually recorded for the same data may differ. Similarly, the gray balance may be different when the recording head is replaced. Furthermore, the gray balance may change due to aging of the apparatus including the recording head, and the color of the recorded image may change.

  One of the direct causes of such a gray balance difference or change is a variation in ink ejection amount (volume of ejected ink droplets). That is, when the specifications of the recording apparatus and the recording head are different or change over time, the ink discharge amount changes accordingly, and the size of the dots formed as a result changes. The difference in dot size occurs for each ink color, and the color or density balance, that is, the gray balance, depending on the combination of these colors may be impaired.

  For example, in a case where a higher-accuracy gray balance such as a monochrome photograph is required as the image quality of the printer increases, the gray balance is tinted due to the loss of the gray balance, or only a certain gradation is obtained. A phenomenon such as so-called color shift occurs due to coloration. In order to reduce the granularity of gray tones in the low density area, recording is performed using light ink with a low color material density. This is caused by recording with black ink in a high density region.

  The variation in the size (ejection amount) of the ejected ink droplets described above is about ± 10% although the recording head is manufactured relatively accurately. As a result of examination, it has been found that due to the variation in the size of the ink droplets, the variation in the actually recorded density is about ± 7% at the maximum. That is, the size of the dots formed on the recording medium varies due to the variation in the size of the ink droplets, and as a result, the difference in the coverage of the dots covering the recording medium appears as the variation in the recording density. .

  Conventionally, methods described in Patent Literature 1 and Patent Literature 2 are known as methods for calibrating such gray balance. In these methods, a patch pattern is recorded, read by a measuring instrument such as a scanner, and the density correction table is corrected based on the read result. However, these calibrations (calibration) often require a measuring instrument such as a scanner, or when the color or type of ink increases, the pattern increases and the recording is often complicated.

  On the other hand, in Patent Document 3 and Patent Document 4, calibration is performed by selecting a patch with the best gray balance by visual observation from the recorded patch patterns, that is, a patch that looks the most gray. Are listed.

JP 2004-50431 A JP 2004-160970 A US Pat. No. 5,604,567 US Pat. No. 6,030,066

  However, although the calibrations described in Patent Documents 3 and 4 can be performed without using a special instrument such as a measuring instrument, the accuracy is higher than that for measuring a patch using a measuring instrument. There is a problem of falling. That is, when the user visually observes, the patch selection depends on the user, such as what is selected as the most balanced patch depending on the user, and as a result, the calibration accuracy may be lowered. This problem becomes more pronounced as the number of patches increases as shown below.

  In addition, the calibration methods described in Patent Documents 3 and 4 are similar to those described in Patent Documents 1 and 2, and as the type of ink used increases, the number of patches to be recorded increases accordingly and patch recording itself is performed. It basically has the problem of becoming complicated. Along with this, there is a problem that it becomes difficult for the user to select a patch with the most gray balance from many patches.

  The present invention has been made in order to solve the above-described conventional problems. The object of the present invention is to provide a highly accurate calibration based on visual patch selection and a relatively small number of patches to be used. An object of the present invention is to provide an ink jet recording apparatus and a calibration method capable of executing a small amount of calibration.

Therefore, in the present invention, a plurality of recording heads that discharge a plurality of types of ink are used, recording data is generated as density values obtained by converting image data, and a recording medium is generated from the plurality of recording heads based on the generated recording data. An ink jet recording apparatus that performs recording by ejecting ink onto the ink, and includes calibration means for calibrating the conversion characteristics, wherein the calibration means includes yellow, light cyan, and light among the plurality of types of ink colors. For a first group of magenta, a plurality of patches are recorded based on a combination of a plurality of density values for each of those colors, and based on patch information selected from the recorded patches, density values corresponding to the patch Each of the colors of the first group so that the image data is converted into respective density values of the combinations of A first calibration step of calibrating the conversion characteristic, the plurality of types of inks of colors, the density values obtained in the conversion characteristic for converting the density values first with yellow group corresponding to the selected patches And a plurality of patches for the second group of yellow, cyan, and magenta based on combinations of cyan and magenta density values, and based on patch information selected from the recorded patches, A second calibration stage for calibrating the conversion characteristics of cyan and magenta among the colors of the second group so that the image data is converted into the density values of the respective color value combinations corresponding to the patch; , And performing the calibration.

  In another aspect, the calibration means selects a density value of the first group of colors corresponding to a patch selected in the first calibration stage for a third group including the first group of colors and black. A combination patch and a plurality of patches based on a plurality of black density values are recorded, and based on patch information selected from the recorded black plurality of patches, the black density value corresponding to the patch is changed to the black density value. The calibration is further performed by further including a third calibration stage for calibrating the black conversion characteristics so that the image data is converted.

Also, using a plurality of recording heads that discharge a plurality of types of ink, recording data is generated as density values obtained by converting image data, and ink is discharged from a plurality of recording heads to a recording medium based on the generated recording data. A calibration method for calibrating the conversion characteristics in an ink jet recording apparatus that performs recording, and for each of the colors of the first group of yellow, light cyan, and light magenta among the plurality of types of ink colors A plurality of patches are recorded based on a combination of a plurality of density values, and the image data is stored in each density value of the combination of density values corresponding to the patch based on patch information selected from the recorded patches. A first calibration for calibrating the conversion characteristics of each of the colors of the first group so as to be converted And step, among the color inks of said plural kinds, and the density values obtained in the conversion characteristic for converting the density values corresponding to the selected patches for yellow of the first group, second becomes yellow, cyan, magenta A plurality of patches are recorded for two groups based on a combination of a plurality of density values of cyan and magenta, and a combination of density values corresponding to the patch is selected based on patch information selected from the recorded patches. And a second calibration step for calibrating the conversion characteristics of cyan and magenta among the colors of the second group so that the image data is converted into the density values of the respective colors.

  According to the above configuration, the conversion characteristics of one color in the first calibration stage where the conversion characteristics are already calibrated can be maintained and the patches of each color of the second group can be recorded. The number can be reduced. In other words, even with a small number of patches, it is possible to reliably find, for example, the patch with the most gray balance among the patches. In addition, even if there are few patches such as this, if there are surely gray-balanced patches as described above, the patch that looks the most gray is selected from the few patches, so the selection does not vary and is accurate. It is possible to select a patch.

  In addition, since it is possible to select a black patch having a density close to that of, for example, process black based on each color corresponding to the correction table already determined in the first group, the number of patches to be recorded can be reduced in this case as well. Since the selection is based on the comparison, it is possible to prevent a decrease in patch selection accuracy even if the number of patches to be recorded is reduced.

  As a result, it is possible to execute calibration based on visual patch selection with high accuracy and a relatively small number of patches to be used.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a perspective view showing a schematic configuration of an ink jet printer according to an embodiment of the ink jet recording apparatus of the present invention.

  In FIG. 1, the recording head 105 is detachably mounted on the carriage 104. In the present embodiment, the recording head 105 includes cyan (C), magenta (M), yellow (Y), and black (K) inks, and light cyan (Lc), which has a lighter colorant density such as a dye than cyan ink. Each recording head ejects the same light magenta (Lm) ink. The carriage 104 can be moved along the main scanning guide 103 by being driven by a carriage driving mechanism (not shown) such as a motor. With this movement of the carriage, the recording head 105 scans the recording medium 102 such as recording paper (hereinafter referred to as “main scanning”), and ejects ink from the recording head 105 along with this scanning. That is, the recording head 105 includes an ejection port on the surface facing the recording medium 102 for each ink, and ejects each ink according to the recording data during the main scan. Each ink recording head is supplied with ink from a corresponding ink tank (not shown) via an ink supply path.

  The pair of paper feed rollers 101 sandwich the recording medium 102 and rotate in that state, thereby conveying the recording medium 102 in the sub-scanning direction. Recording is performed on the entire recording medium 102 by repeating a predetermined amount of this conveyance and the above-described main scanning of the recording head. The platen 106 is provided below the scanning area of the recording head, and supports the recording medium to be conveyed, so that the recording surface of the recording medium is held flat during the conveyance. Although not shown in FIG. 1, this ink jet printer has a recording medium supply mechanism for supplying the recording medium to the paper feed roller, a recovery mechanism for maintaining the ejection characteristics of the recording head properly, and the recording medium after the recording is completed. Is provided with a recording medium discharge mechanism.

  In the above configuration, when a recording start command signal is input from the host device, the recording medium is supplied until the recording medium reaches the position of the paper feed roller 101 by the recording medium supply mechanism. Thereafter, the recording medium 102 is fed to the recording position of the recording head 105 by the paper feed roller 101. Subsequently, the recording head 105 ejects ink droplets onto the recording medium while performing main scanning, and recording is performed on the recording medium by repeatedly carrying the recording medium by the paper feed roller 101. The recording medium 102 for which recording has been completed is discharged in the lower left direction in FIG.

  The recording head of the present embodiment uses a heating element (electrothermal conversion element), and by applying an electrical signal corresponding to the recording data to the heating element, the ink is locally heated to generate bubbles. This relates to a system in which ink is ejected by the pressure of the bubbles. The discharge method is not limited to this, and for example, a method of discharging ink by pressure similarly by mechanical deformation using an electromechanical transducer such as a piezoelectric element may be used.

  FIG. 2 is a block diagram showing a configuration of control and image processing of the ink jet printer shown in FIG.

  In FIG. 2, reference numeral 310 denotes an interface for transmitting / receiving data or signals to / from the host apparatus such as receiving recording data from the host apparatus. The MPU 311 performs data processing for controlling the recording operation in the printer based on the recording data transmitted from the host device. This processing includes image processing described later with reference to FIG. In addition, the MPU 311 executes a calibration process described later with reference to FIG. The ROM 312 stores the processing program of FIG. 5 executed by the MPU 311 and the like. The RAM 313 temporarily stores various data such as recording data and table data related to calibration described later. In addition, the RAM 313 stores the number of recording dots, the number of replacements of the recording head, and the like. The gate array 314 controls the supply of recording data to the recording head according to the control of the MPU 311 and also controls the transfer of data among the interface 310, the MPU 311 and the RAM 313. Reference numeral 320 denotes a carrier motor for moving the carriage, and 319 denotes a conveyance motor for conveying the recording paper. Reference numeral 315 denotes a head driver for driving the recording head 105 to perform ejection, and reference numerals 316 and 317 denote motor drivers for driving the transport motor 19 and the carrier motor 320, respectively.

  FIG. 3 is a block diagram for explaining the image processing by the configuration shown in FIG.

  As shown in FIG. 3, image data 201 is transmitted from the host computer as RGB signals. The sent RGB signals are converted into R ′, G ′, B ′ signals for photographs, graphics, etc. in accordance with the recording mode by the conversion table 202. After that, in the conversion 203, the output colors of the printer of this embodiment are converted into six colors C, M, Y, K, Lc, and Lm. Next, output γ correction 205 is performed using the output correction table selected by the output correction table selector 204. In the present embodiment, the selector 204 selects, for each color, a correction table that has been calibrated as described in FIG. In this embodiment, for each color of processing, one is selected from three types of correction tables according to the ejection amount of each recording head used in the printer. Specifically, one correction table is selected based on the ejection amount information of each of the six recording heads stored in the memory (for example, ROM 312) of the printer. More specifically, three types of correction tables shown in FIG. 4 are preset for each of the six colors, and one type of correction table is used for each of the six color recording heads used in the printer according to the discharge amount (characteristic). The correction table corresponds, and is selected by the selector 204. In the calibration described later, the corresponding correction tables are calibrated. That is, if the discharge amount changes, one of the tables 0, 1, and 2 shown in FIG. 4 is set accordingly.

  With a configuration in which a plurality of types of correction tables are prepared in advance, for example, in a printer that can be used by replacing recording heads with different discharge amounts, a correction table is selected according to the mounted recording head, Appropriate γ correction according to the discharge amount can be performed. Alternatively, in a mode in which the image processing shown in FIG. 3 or a part thereof is performed by a host device such as a host computer, even when a printer having a different specification is connected to the host device, the discharge amount of the printer is reduced. Accordingly, an appropriate correction table can be selected and γ correction can be performed.

  In applying the present invention, it is not necessary to set a plurality of correction tables in advance as described above, and one correction table is set in advance as in normal image processing, and γ correction is performed using the correction table. May be. In this case, it goes without saying that the calibration described later, to which the present invention is applied, is performed on this one correction table.

  In this embodiment, these three types of correction tables are assumed to have a width of ± 10% in the difference in the ejection amount of the recording head due to the difference in the specifications. The range is divided into three equal parts, and correction factors of + 7%, 0%, and 7% are obtained, respectively. In this case, the concentration differs by about 5% at the maximum. FIG. 4 is a diagram schematically showing this correction table. As shown in the figure, the correction table is table 2 in the plus direction, table 1 at the center, and table 0 in the minus direction.

  Next, resolution conversion 206 is performed on the image signals C ′, M ′, Y ′, K ′, Lc ′, and Lm ′ subjected to the γ correction 205 as described above, and finally, binarization processing is performed. 207 is performed to obtain recording data C ′ ″, M ′ ″, Y ′ ″, K ′ ″, Lc ′ ″, Lm ′ ″ (208). The ink jet printer performs recording based on binary recording data obtained by the above image processing.

  Several embodiments of calibration in the ink jet printer according to one embodiment of the present invention described above with reference to FIGS. 1 to 3 will be described below.

(Embodiment 1)
FIG. 5 is a flowchart showing a calibration process according to an embodiment of the present invention.

  As shown in the figure, when the user selects the “color adjustment” function via an operation panel (not shown) set in the printer main body (step S51), this processing is started.

  First, among the six ink colors, the pattern A which is a patch pattern of the first group of Y, Lc, and Lm is recorded by the printer (step S52). This patch pattern A is set as follows.

  The pattern A is configured by a combination of fixed patch data set in advance. FIG. 6 is a diagram for explaining the fixed patch data. As shown in the figure, as the fixed patch data, three data are set for each color for each of the first group and the second group. That is, it is assumed that there is no variation in the ejection amount among the three color recording heads in each group. In this case, the density value of each color (a value in the range of 0 to 255 corresponds to the dot coverage) when the three colors of ink ejected from the respective recording heads are achromatic. ) Is 0% patch data. Then, with the 0% patch data as a reference, the -7% and + 7% density value data of each reference for each color are set as -7% patch data and + 7% patch data, respectively.

  The distribution of the patches of 0% patch data for all three colors of the first group in the above patch data is devised so that when this is recorded on the coated paper, the optical density becomes gray (achromatic color) of about 0.6. The pattern A is composed of 19 patches centered on this patch and including a combination of -7%, 0%, and + 7% patch data shown in FIG. FIG. 7 shows combinations of the patch data of 19 patches, and FIG. 8 is a diagram schematically showing a pattern A in which these patches are actually recorded, that is, a recorded pattern A. As shown in FIG. 7, the pattern A has 27 combinations of -7%, 0%, and + 7% patch data so as to be a pattern centered on gray having an optical density of about 0.6 as described above. From the above, a set of 3 color patch data becomes + 7% patch data, a set of all −7% patch data, 2 colors 0% and 1 color + 7% or −7% patch data 6 sets are removed, and 19 sets of patches are included.

  Of course, the configuration of the pattern is not limited to the above configuration. Further, in order to facilitate visual determination, a gray patch may be recorded as a sample near the patch for comparison as shown in FIG. In this case, recording is performed with black ink using halftone. The density value is devised so as to be almost the same as the optical density of these patches.

  In the process shown in FIG. 5, when pattern A is recorded as described above, the patch that appears the most gray is selected from pattern A (step S53).

  When the gray balance changes due to the variation in the ink discharge amount of the recording head, the patch that looks the most gray in the patches 0 to 18 of the pattern A shown in FIG. 8 changes. That is, this most grayish patch indicates a combination of density values that achieves gray balance even though the ejection amount varies in the print head. The user inputs the number of the selected patch that looks the most gray via the operation unit. The input patch number data is stored in the memory of the printer. Based on the patch number, the table shown in FIG. 9 is referred to, and the table numbers for Lc, Lm, and Y3 (one of 0, 1, and 2; see FIG. 4) are set. For example, when patch number “5” is selected from pattern A and is input, as shown in FIG. 9, table 1 is set for Lc, table 0 is set for Lm, and table 1 is set for Y. . In this example, as is clear from FIG. 7, Lc and Y correspond to 0% patch data, and Lm corresponds to -7% patch data. That is, the above table is set on the assumption that the discharge amounts of the Lc and Y recording heads are not deviated from the assumed reference discharge amount, and the discharge amount of the Lm recording head is -7%.

  In step S54 following the process shown in FIG. 5, the patch pattern B is recorded in cyan (C), magenta (M), and yellow (Y) according to the second group. Here, Y belongs to the first group as described above, and the correction table has already been determined. The patch recording in this step uses the second group of patch data shown in FIG. 6. The Y patch data is the first stage of determining the correction table in the second group of data. Patch data corresponding to the correction table determined in step S53 is used. For example, if the Y correction table is determined as the table 2 in the first stage, the density value 31.1 which is + 7% patch data corresponding to this table is fixedly used. According to this configuration, the patch of each color of the second group can be recorded while maintaining the tendency of the ejection amount of the recording head of one color (Y in the above example) that has already been determined in the correction table. The number of patches can be reduced. In other words, even with a small number of patches, it is possible to reliably find the most gray-balanced patch among those patches. In addition, when there are surely gray-balanced patches even with such a small number of patches, the patch that looks the most gray is selected from the few patches, and the patch is selected accurately without variation. It becomes possible.

  FIG. 10 shows the data of each patch of the patch pattern B by the combination of the C, M, and Y patch data of the second group determined as described above, and FIG. 11 shows the patch of the pattern B actually recorded. It is a schematic diagram. As shown in these figures, in this embodiment, the pattern B is composed of nine patches, each of which is a combination of three types of patch data C and M shown in FIG. Is done.

  As in the first stage, in order to facilitate patch selection, a gray patch may be recorded as a sample near the patch for comparison.

  Next, in step S55, the user selects the closest recorded gray patch from the nine recorded patches, inputs the number in the operation unit, and stores the value in the memory. In this step as well, as in step S53, the table shown in FIG. 12 is referred to by the input patch number, and the table numbers of C and M2 colors (0, 1, 2; see FIG. 4) are used. Set.

  Finally, in step S56, the correction tables for the colors of the first group and the second group set in steps S53 and S55 are stored in a predetermined memory of the printer, and the calibration of the present embodiment is completed. As described above, the set correction tables for the respective colors are selected and used by the selector 204 during recording.

  In a mode in which one correction table is used instead of selecting from three types of correction tables at the time of recording, correction is made with reference to the tables shown in FIG. 9 and FIG. Instead of setting a table, for example, for each color, one correction table is selected from a plurality of correction tables prepared in advance, and a correction used for recording is selected. Set as a table.

  In this embodiment, a fixed correction table is used for black (K), and calibration is not performed for this.

(Second Embodiment)
In the first embodiment, calibration is not performed for K. However, in this embodiment, correction table determination is performed for the first group and the second group described in the first embodiment, and the third group is further determined. And a correction table for K included in the group is set.

  FIG. 13 shows the patch data of each color in the third group, and FIG. 14 is a diagram showing the relationship between these patch data and the correction table to be set. FIG. 15 is a diagram showing a patch pattern actually recorded. As shown in these drawings, the third group is K, Lc, Lm, and Y, and a correction table for K is set based on these patches.

  Specifically, for K, a patch having the same patch data combination as the patch of the number selected in the first group selected in the first stage described in the first embodiment is recorded as a comparison patch (process black). Then, three types of patch data patches shown in FIGS. 13 to 14 are recorded as black patches. From the three types of patches, the K patch having the closest density to the comparison patch is selected and the number is input via the operation unit. Then, based on the patch number, the K correction table is determined with reference to the table shown in FIG. In this way, since the process black of each color corresponding to the correction table already determined in the first group can be used as a reference and a black patch with a density close to that can be selected, the number of patches to be recorded can be reduced in this case as well. Since the selection is based on the comparison, it is possible to prevent a decrease in patch selection accuracy even if the number of patches to be recorded is reduced.

(Third embodiment)
FIG. 17 is a block diagram showing an image processing configuration according to this embodiment, and is the same diagram as FIG. 3 according to the first and second embodiments. A difference from the configuration shown in FIG. 3 is that the transformation 203 and the γ correction 205 shown in FIG. 3 are performed as one process. Specifically, the conversion process is performed using a conversion table obtained by combining the conversion 203 and the γ correction 205. In this case, as in the first and second embodiments, one conversion table is selected by the selector 204 from the three types of conversion tables, and is used for recording data generation.

  Specifically, there are three types of conversion tables from R, G, B to C, M, Y, K, Lc, and Lm, respectively, and the conversion table is selected according to the discharge amount of each recording head. After performing the conversion processing using, binarization processing is performed, and recording is performed based on the finally obtained recording data. This configuration is different from R, G, B after conversion from R, G, B to C, M, Y, K, Lc, Lm and switching between three types of correction tables as in the first embodiment. The conversion from C to M, Y, K, Lc, and Lm is performed using a conversion table in which correction coefficients are synthesized in advance, and the correction is also completed by a single conversion. As a result, it is possible to obtain an effect such that the quantization error can be reduced by reducing the number of conversions.

  The calibration according to an embodiment of the present invention is performed for the above three types of conversion tables, as in the first and second embodiments. Then, the conversion table set by the calibration is selected by the selector 204.

(Other embodiments)
In each of the above-described embodiments, the calibration for the case of processing image data using a table such as a correction table or a conversion table has been described. It goes without saying that the object to be converted can be targeted and its conversion characteristics can be determined by calibration. For example, the calibration can be executed even when correction or conversion is performed by calculation without using a table. That is, the calculation coefficient can be determined based on the selected patch number, and the conversion characteristics can be calibrated.

  In each of the above embodiments, image processing and calibration are performed on the side of an ink jet recording apparatus such as a printer. However, in a configuration in which image processing is executed by a host device such as a personal computer, each of the above embodiments is used. Calibration using the described calibration method can also be executed by the host device. In this case, a multifunction machine having a copying function, a communication function, and the like may execute calibration as a host device for other printers and multifunction machines.

1 is a perspective view illustrating a schematic configuration of an ink jet printer according to an embodiment of an ink jet recording apparatus of the present invention. FIG. 2 is a block diagram illustrating a configuration of control and image processing of the ink jet printer illustrated in FIG. 1. It is a block diagram for demonstrating the image processing by the structure shown in FIG. It is a figure which shows typically the correction table which concerns on one Embodiment of this invention. It is a flowchart which shows the calibration process which concerns on one Embodiment of this invention. It is a figure explaining this fixed patch data concerning one embodiment of the present invention. It is a figure which shows the combination of the patch data of 19 patches obtained by the combination of patch data shown in FIG. It is a figure which shows typically the pattern A which actually recorded the patch shown in FIG. It is a figure which shows the table referred in the case of the setting of a correction table regarding one Embodiment of this invention. It is a figure which shows the data of each patch of the patch pattern B by the combination of the patch data of C, M, and Y of the 2nd group which concerns on one Embodiment of this invention. It is a schematic diagram which shows a patch when the pattern shown in FIG. 10 is actually recorded. It is a figure which shows the table referred in the case of the setting of a correction table regarding one Embodiment of this invention. It is a figure which shows the patch data of each color of a 3rd group regarding the 2nd Embodiment of this invention. It is a figure which shows the relationship between the patch data shown in FIG. 13, and the correction table set. It is a figure which shows a patch when the pattern shown in FIG. 13, FIG. 14 is actually recorded. It is a figure which shows the table referred in the case of the setting of a correction table regarding the 2nd Embodiment of this invention. It is a block diagram which shows the image processing structure which concerns on the 3rd Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 101 Paper feed roller 102 Recording medium 103 Main scanning guide 104 Carriage 105 Recording head 106 Platen 310 Interface 311 MPU
312 ROM
313 RAM
314 Gate array 319 Carrying motor 320 Carrier motor

Claims (6)

Using a plurality of recording heads that discharge a plurality of types of ink, generating recording data as density values obtained by converting image data, and discharging ink from a plurality of recording heads to a recording medium based on the generated recording data An inkjet recording apparatus that performs recording,
Calibration means for calibrating the characteristics of the conversion, wherein the calibration means includes a plurality of density values for each of the colors of the first group of yellow, light cyan, and light magenta among the plurality of types of ink colors; A plurality of patches are recorded based on the combination of the image data, and the image data is converted into each density value of the combination of density values corresponding to the patch based on the patch information selected from the recorded patches. A first calibration stage for calibrating the conversion characteristics of each of the colors of the first group;
Of the plurality of types of ink colors, the second group of yellow, cyan, and magenta density values obtained by conversion characteristics for converting the yellow color of the first group into density values corresponding to the selected patch. A plurality of patches are recorded based on combinations of cyan and magenta density values, and each color of the combination of density values corresponding to the patch is selected based on patch information selected from the recorded patches. A second calibration stage for calibrating the conversion characteristics of cyan and magenta among the colors of the second group so that the image data is converted into a density value of
An ink jet recording apparatus characterized in that calibration is performed including: The calibration means calibrates conversion characteristics by determining one table from a plurality of tables that can be used for the conversion. In the first calibration stage, each of the first groups A plurality of patches are recorded based on a combination of density values respectively corresponding to the plurality of predetermined tables for colors, and a table corresponding to the density value of each color of the combination of density values corresponding to the selected patch is displayed. It is determined as a table to be converted into the density value of the color, and in the second calibration stage, the combination of density values respectively corresponding to the plurality of tables determined in advance for the yellow of the first group density value and cyan corresponding to the table determined in the first stage, Noso magenta Recording a plurality of patches, cyan combination of density values corresponding to the selected patch, corresponding to each density value magenta based on a predetermined combination of the corresponding density value to each of the plurality of tables for, respectively 2. The ink jet recording apparatus according to claim 1, wherein the table is determined as a table for converting the density value of the color. The calibration means includes a patch of a combination of density values of the first group color corresponding to the patch selected in the first calibration stage for a third group including the first group color and black; A plurality of patches based on a plurality of black density values are recorded, and the image data is converted into a black density value corresponding to the patch based on patch information selected from the recorded plurality of black patches. so that the ink jet recording apparatus to claim 1 or 2, characterized in that the calibration further include a third calibration step to calibrate the conversion characteristics of the black. Using a plurality of recording heads that discharge a plurality of types of ink, generating recording data as density values obtained by converting image data, and discharging ink from a plurality of recording heads to a recording medium based on the generated recording data An inkjet recording apparatus that performs recording,
Calibration means for calibrating the characteristics of the transformation, the calibration means comprising:
Patch information selected from the recorded patches by recording a plurality of patches based on a combination of a plurality of density values for each of the groups of a predetermined number of colors of the plurality of types of ink. A process of calibrating conversion characteristics of each color of the group so that the image data is converted into respective density values of the density value combinations corresponding to the patch, based on a plurality of at least two stages. Conversion that executes calibration in stages, and converts to density values corresponding to patches selected for yellow included in the yellow, light cyan, and light magenta groups in the previous stage processing in the later stage processing the density values obtained in characteristic, yellow, cyan, the group of magenta cyan, respectively magenta Recording a plurality of patches on the basis of the combination of the density value of the number, cyan, an ink jet recording apparatus characterized by calibrating a conversion characteristic for magenta. Using a plurality of recording heads that discharge a plurality of types of ink, generating recording data as density values obtained by converting image data, and discharging ink from a plurality of recording heads to a recording medium based on the generated recording data A calibration method for calibrating the conversion characteristics in an inkjet recording apparatus that performs recording,
A plurality of patches are recorded on the first group of yellow, light cyan, and light magenta among the plurality of types of ink colors based on a combination of a plurality of density values for each of the colors, and from among the recorded patches Based on the selected patch information, a first calibration for calibrating conversion characteristics of each color of the first group so that the image data is converted into respective density values of a combination of density values corresponding to the patch. Step and
Among the plurality of types of ink colors, a density value obtained by conversion characteristics for converting the density of the first group of yellow to a density value corresponding to the selected patch, and a second group of yellow, cyan, and magenta A plurality of patches are recorded based on combinations of cyan and magenta density values, and each color of the combination of density values corresponding to the patch is selected based on patch information selected from the recorded patches. A second calibration step for calibrating the conversion characteristics of cyan and magenta among the colors of the second group so that the image data is converted into a density value of
A calibration method characterized by comprising: The calibration calibrates conversion characteristics by determining one table from a plurality of tables that can be used for the conversion. In the first calibration step, each color of the first group is calibrated. A plurality of patches are recorded based on a combination of density values respectively corresponding to the plurality of tables determined in advance, and a table corresponding to the density value of each color of the combination of density values corresponding to the selected patch In the second calibration step, among the combinations of density values respectively corresponding to the plurality of tables determined in advance for the first group of yellow , the second calibration step determines the table for the color. concentration values corresponding to the table determined in one step and the cyan, magenta Recording a plurality of patches based on a combination of the corresponding density values respectively to a predetermined plurality of tables for each of cyan combination of density values corresponding to the selected patch, corresponding to each density value magenta table The calibration method according to claim 5 , wherein: is determined as a table for converting the density value into the density value of the color.

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