Recording device, recording method, and program

Abstract

To appropriately adjust a recording position even when a test chart recorded on a recording medium is read in parts.SOLUTION: A print controller converts a representative position of a patch corresponding to each of recording element substrates for a first read image and a second read image into differential position information from an original point positioned in an overlapping region of each read image. The print controller converts differential position information of the second read image so that a degree K of shrinkage becomes 1 on the basis of the differential position information and the degree of shrinkage of the second read image. Conversion such that the degree of shrinkage becomes 1 means such conversion that a distance between specific patterns in the second read image becomes equal to a distance between corresponding same specific patterns in the first read image. The print controller calculates an inclination of a reference line for calculating a deviation amount between the recording element substrates with respect to the first read image.SELECTED DRAWING: Figure 18

Description

[Technical field]

[0001] The present invention relates to a control technique for adjusting a printing position in a printing apparatus. [Background technology]

[0002] Printing apparatuses using so-called full-line print heads having a print width equivalent to the width of the print medium are known, and one such printing apparatus is an inkjet printing apparatus. The print head in a full-line inkjet printing apparatus has a plurality of print element substrates each including a plurality of nozzle rows, and can print an image on almost the entire surface of the print medium by moving the print head once relative to the print medium. In a printing apparatus provided with a full-line print head, an error may occur in the mounting position of the print head or in the relative mounting positions between the plurality of print heads. This error causes a deviation in the deposition position of the print material on the print medium (the ink landing position in an inkjet printing apparatus), which causes a decrease in print quality. Hereinafter, the process of correcting the deviation in the deposition position of the print material is referred to as "print position adjustment."

[0003] In the print position adjustment, a scanner device equipped with an image sensor reads a test chart printed on a print medium, and first detects the positions of patches corresponding to the nozzle array and print element substrates included in the test chart from the read image. Then, the relative positions between these patterns are obtained, and the print position is adjusted based on these relative positions. As a method for improving the accuracy of patch position detection, Patent Document 1 discloses a method for adjusting the print position based on the amount of deviation between the print element substrates obtained from the distance between each print element substrate and a reference line connecting the estimated positions of two print element substrates close to both ends of the print head.

[0004] When performing large-format printing with an inkjet recording device that uses a full-line type recording head, the recording head must be made larger to match the recording medium. As the recording head becomes larger, the test chart for adjusting the recording position also becomes larger, so the scanner device needs a reading size that corresponds to the size of the test chart. Some scanner devices with a large reading size combine multiple image sensors. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2020-172084 A Summary of the Invention [Problem to be solved by the invention]

[0006] However, when using a scanner device combining multiple image sensors in the technology described in Patent Document 1, the positions of the two recording element substrates close to both ends of the recording head for determining the reference line are estimated based on two read images with different reading conditions. As a result, the estimation accuracy of the relative positions of the two recording element substrates for determining the reference line decreases, and the accuracy of the reference line also decreases, making it impossible to adjust the recording position appropriately.

[0007] SUMMARY OF THE PRESENT DISCLOSURE An object of the present invention is to appropriately adjust the recording position even when a test chart recorded on a recording medium is read in divided portions. [Means for solving the problem]

[0008] The present invention is a recording device having one or more recording means including a plurality of recording element substrates that apply recording material, and is characterized in that it comprises a reading control means for dividing a test chart including a plurality of patches corresponding to each of the recording element substrates printed on the recording medium by the recording means using a plurality of optical sensors and having a reading device read it, a calculation means for calculating an expansion / contraction rate of a patch corresponding to the recording element substrate included in the same recording means for a pair of read images consisting of two read images out of a plurality of read images obtained by having the reading device read the test chart printed on the recording medium, and an adjustment means for adjusting the deposition position of the recording material applied from the recording means based on the expansion / contraction rate calculated by the calculation means and position information of the patch in the plurality of read images. Effect of the Invention

[0009] According to the present invention, even if the test chart recorded on the recording medium is read in divided portions, it is possible to appropriately adjust the recording position. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a schematic diagram of an inkjet recording apparatus. [Diagram 2] 1 is a top view of the scanner device when the scanner device reads a test chart. [Diagram 3] FIG. 2 is a block diagram showing a hardware configuration for controlling the inkjet printing apparatus. [Figure 4] 5A and 5B are diagrams for explaining patches for correcting nozzle row position deviation. [Diagram 5] FIG. 11 is a diagram showing an example of a pattern for pattern matching. [Figure 6] FIG. 2 is a diagram showing the positional relationship between a scanner device, a test chart, and a recording head. [Figure 7] FIG. 4 is a diagram for explaining a test chart for correcting head position deviation. [Figure 8] 6 is a diagram for explaining a method for calculating the amount of misalignment between nozzle rows. [Figure 9] 5A and 5B are diagrams for explaining a method for calculating the amount of misalignment between recording element substrates. [Figure 10] 5A and 5B are diagrams for explaining a method for calculating the amount of tilt of a print head. [Figure 11] 5A and 5B are diagrams for explaining a method for calculating the amount of misalignment between recording heads. [Figure 12] 5A and 5B are diagrams for explaining detection of a detection mark of a patch corresponding to a recording element substrate. [Figure 13] 1A and 1B are diagrams showing examples of two read images obtained from two sensors of a scanner device. [Figure 14] 6 is a flowchart for explaining a deviation amount calculation process according to the embodiment. [Figure 15] 5 is a flowchart for explaining a deviation amount calculation process 1 according to the present embodiment. [Figure 16] 6 is a diagram for explaining a procedure for calculating a ratio of expansion / contraction between read images. [Figure 17] 6 is a flowchart for explaining a second deviation amount calculation process according to the present embodiment. [Figure 18] 10A and 10B are diagrams for explaining a procedure for correcting differential position information of each recording element substrate of one read image with a corresponding expansion / contraction ratio according to the embodiment. [Figure 19] 5A to 5C are diagrams for explaining a procedure for obtaining a reference line according to the embodiment. [Figure 20] 6A and 6B are diagrams for explaining a procedure for correcting the inclination of a reference line according to the embodiment and calculating the coordinates of each recording element substrate of a second read image on a first read image. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] The present embodiment will be described with reference to the drawings. Note that the components described in the embodiment are merely exemplary embodiments of the present invention, and the scope of the present invention is not limited to these components.

[0012] 1 is a front view showing a schematic diagram of an inkjet recording apparatus 100 according to this embodiment. The inkjet recording apparatus 100 is an apparatus that prints on continuous paper (hereinafter referred to as roll paper) 110, which is used in this embodiment and on which continuous printing can be performed. In this embodiment, the inkjet recording apparatus 100 is made up of a paper feeder 103 that transports the roll paper 110, a main unit 111 that performs printing, a paper discharge device 104 that takes up the roll paper 110, and an operation panel 101.

[0013] The paper feeder 103 is a device that supplies roll paper 110 to the main unit 111. The paper feeder 103 rotates the paper tube of the roll paper 110 around a rotating shaft 112, and transports the roll paper 110 wound around the paper tube toward the inkjet recording device 100 at a constant speed via multiple rollers (transport rollers, paper feed rollers, etc.).

[0014] The paper discharge device 104 is a device that winds up the roll paper 110 transported from the main unit 111 around a paper tube. In the paper discharge device 104, for example, as shown in the figure, the roll paper 110 is wound around a paper tube of a rotating shaft 113 and held in a roll shape. The paper discharge device 104 is a device that winds up the roll paper 110, which has been rotated around the rotating shaft 113 and transported to the paper tube, at a constant speed as a roll paper product via multiple rollers (e.g., transport rollers, paper discharge rollers) around the rotating shaft 113. Before printing begins, the roll paper 110 is passed from the paper feed device 103 to the paper discharge device 104. The roll paper 110 is set in the paper feed device 103, and the leading edge of the roll paper 110 is passed over the skew correction device 109. Next, it is passed under the inkjet recording head 102 of the main unit 111, under the drying device 105, and over the cooling devices 107 and 108. The paper is passed through a scanner device 106 and wound up by a paper discharge device 104 .

[0015] The scanner device 106 uses an optical sensor to optically read the print pattern printed on the roll paper. After the roll paper 110 is passed through the inkjet recording device 100, a print job is submitted to the control PC 114 of the inkjet recording device 100. After the print job is submitted, the print start button on the operation panel 101 is pressed to start printing.

[0016] FIG. 2 is a bird's-eye view from above the scanner device 106 when the scanner device 106 reads the test chart. The recording medium P, which is the roll paper 110, is conveyed in a conveying direction 201, and the conveying speed is adjusted near the scanner device 106, and an image of an imaging area 203 is captured using sensors 202A and 202B, which are optical sensors. The sensors 202A and 202B are arranged in a staggered configuration so that a part of the imaging area overlaps with the side of the scanner device 106 facing the recording medium P. Due to this staggered arrangement, the sensors 202A and 202B are arranged at a distance from each other along the conveying direction 201. The sensors 202A and 202B each include an imaging element (not shown), such as a CCD sensor or a CMOS sensor. The read image of the imaging area 203 obtained by the scanner device 106 is used to calculate various correction values. The method of calculating the correction values ​​will be described later. The scanner device 106 may be pre-installed in the main unit 111 or may be installed as an option.

[0017] 3 is a block diagram showing a hardware configuration for controlling the inkjet recording apparatus 100. The control configuration is mainly composed of a print engine unit 400 that controls the print engine, and a controller unit 300 that controls the entire inkjet recording apparatus. A print controller 402 controls various mechanisms of the print engine unit 400 according to instructions from a main controller 301 of the controller unit 300. The control configuration will be described in detail below.

[0018] In the controller unit 300, a main controller 301 constituted by a CPU controls the entire inkjet recording apparatus 100 using a RAM 305 as a work area in accordance with programs and various parameters stored in a ROM 306. For example, when a print job is input from a host device 500 via a host I / F 302, an image processing unit 307 performs predetermined image processing on the received image data in accordance with instructions from the main controller 301. The main controller 301 then transmits the image data that has been subjected to the image processing to a print engine unit 400 via a print engine I / F 304.

[0019] In addition, the inkjet recording apparatus 100 may obtain image data to be sent to the print engine unit 400 from an external storage device (such as a USB memory) connected to the inkjet recording apparatus 100. The operation panel 303 is a mechanism that enables the user to perform input and output to the recording apparatus. Through the operation panel 303, the user can instruct the printing and paper feed operations, set the print mode, and recognize information about the recording apparatus. The operation panel 303 is a touch panel, and it is also possible to connect a mouse and keyboard for input.

[0020] In the print engine unit 400, a print controller 402 constituted by a CPU controls various mechanisms of the inkjet recording apparatus 100 according to programs and various parameters stored in a ROM 403. At this time, the print controller 402 uses a RAM 404 as a work area. When various commands and image data are received via a controller I / F 401, the print controller 402 temporarily stores them in the RAM 404. The print controller 402 causes an image processing controller 405 to convert the image data stored in the RAM 404 into recording data so that the recording head 102 can use it for a recording operation. When the recording data is generated, the print controller 402 causes the recording head 102 to perform a recording operation based on the recording data via a head I / F 406. At this time, the print controller 402 drives the paper feeder 103 and the paper discharger 104 shown in FIG. 1 via a conveyance control unit 407 to convey the roll paper 110, which is a recording medium. The print controller 402 also drives the heaters and fans of the drying device 105 and the cooling devices 107 and 108 via the transport control unit 407 to dry and cool the transported paper. Furthermore, the transport control unit 407 can detect the transport distance from an encoder provided on the transport roller. Following instructions from the print controller 402, the recording operation by the recording head 102 is executed in conjunction with the transport operation of the roll paper, and printing processing is performed.

[0021] The print head 102 is configured to be able to move up and down (perpendicular to the recording surface of the roll paper 110), is lowered when printing, and is raised for maintenance and the like. A head carriage control unit 408 changes the up and down position of the print head 102 depending on the operating state of the inkjet printing apparatus 100, such as the maintenance state or the printing state. An ink supply control unit 409 controls the ink supply unit so that the pressure of the ink supplied to the print head 102 falls within an appropriate range. When performing maintenance operations on the print head 102, a maintenance control unit 410 moves a maintenance unit under the raised head, and controls head maintenance operations such as capping and wiping.

[0022] The scanner control unit 411 controls the scanner device 106. When the image data for which the recording operation is performed is a test chart that is a pattern for calculating various correction values, the print controller 402 instructs the conveyance control unit 407 to adjust the conveyance speed. Furthermore, the scanner control unit 411, which is instructed by the print controller 402 as to the timing for reading the test chart recorded on the roll paper, causes the scanner device 106 to capture an image and store the resulting read image in the RAM 404. The print controller 402 executes various correction value calculation processing using the stored read image. The print controller 402 passes the obtained correction value to the image processing controller 405, where it is reflected in the recording operation. The stored read image may be transferred to the host device 500 via the controller unit 300, where various correction value calculation processing is performed, and the obtained correction value is output to the print controller 402.

[0023] From here on, a method for correcting the positional deviation of the recording head, which is one of the various correction values, will be described in detail.

[0024] (Method for correcting misalignment of recording head) FIG. 4 is a diagram showing the correspondence between the patches 1007 and 1016 corresponding to one of the recording element substrates 1002 constituting the recording head 102 and the nozzles. The recording head 102 is composed of a plurality of recording element substrates 1002. The recording element substrate 1002 is composed of a plurality of nozzles, and each nozzle is configured to be able to eject ink by driving the recording element. The recording element for ejecting ink may be a heater or a piezoelectric element. In this embodiment, the recording element substrate shows an example in which a plurality of nozzle rows are arranged in the shape of a parallelogram. A nozzle arrangement direction 1001 in which the plurality of nozzles are arranged intersects with the conveyance direction 201 and corresponds to the width direction of the recording medium. In an enlarged view 1006 of the recording element substrate 1002, the recording element substrate 1002 has a plurality of nozzle rows 1005, and one nozzle row 1005 is composed of a plurality of nozzles. A test chart for one recording element substrate 1002 is recorded using nozzles within a range sandwiched between dashed lines 1003 and 1004 of each nozzle array 1005 of the recording element substrate 1002. This range may vary depending on the configuration of the recording element substrate 1002.

[0025] In this embodiment, an example is shown in which the print head is composed of 17 printing element substrates 1002, and each printing element substrate 1002 is composed of 16 nozzle arrays 1005. Each nozzle array is composed of 512 nozzles. Note that the number of printing element substrates 1002 constituting the print head, the number of nozzle arrays 1005 constituting the printing element substrate 1002, and the number of nozzles constituting each nozzle array 1005 are not limited to these.

[0026] For convenience, the nth (n≧0) recording element substrate 1002 counting from the left in the nozzle arrangement direction 1001 is called Cn, and the nth (n≧0) nozzle row 1005 counting from the downstream side in the transport direction 201 is called Rn. For example, the recording element substrate 1031 is C0 because it is located at the left end of the nozzle arrangement direction 1001, and the recording element substrate 1032 is C16 because it is located at the right end. Furthermore, the nozzle row 1005 is R15 because it is located on the most upstream side in the transport direction 201, and the nozzle row 1033 located on the most downstream side is R0. The nozzle row 1033 is composed of 512 nozzles (not shown) from nozzle 1034 as the left end nozzle to nozzle 1035, the right end nozzle. The other nozzle rows are also composed of 512 nozzles in the same manner.

[0027] The patch 1007 is one of the patches corresponding to one recording element substrate 1002. It is configured to include a detection mark 1019, an alignment mark 1020, and a pattern matching pattern 1008.

[0028] The pattern matching patterns 1008 included in the patch 1007 are provided corresponding to each of the multiple nozzle arrays. Here, the pattern matching patterns 1008 are printed using different nozzle arrays 1005. That is, pattern matching patterns 1008 0 to 15 are provided for the 16 nozzle arrays 1005. The layout 1012 shows the arrangement of the pattern matching patterns 1008 for each nozzle array 1005. A numerical value indicating the nozzle array 1005 that prints the pattern matching pattern 1008 at that position is written in the rectangle 1010 corresponding to each pattern matching pattern 1008. For example, "0" is written in the rectangle 1010 corresponding to the pattern matching pattern 1008 printed by the nozzle array 1005 of R0. In this way, the number written in the rectangle is the numerical value n of Rn that indicates the nozzle array 1005 that prints the pattern matching pattern 1008 corresponding to the rectangle. Using the pattern matching pattern 1008 printed by the nozzle array 1005 of R0 as a reference, the positional deviation is calculated from the relative position of each pattern matching pattern 1008 printed by the other nozzle arrays 1005. As an exception, a pattern matching pattern corresponding to a rectangle 1011 is provided. This is the pattern matching pattern 1008 printed by the nozzle array 1005 of R12 among the nozzles included in the recording element substrate 1002 Cn+1, which is the recording element substrate 1002 adjacent to the right of the recording element substrate 1002. Note that the nozzle array 1005 of the adjacent recording element substrate 1002 that prints the pattern matching pattern 1008 corresponding to the rectangle 1011 is not limited to R12. The nozzle array 1005 that prints the pattern matching pattern 1008 corresponding to the rectangle 1011 may change depending on the number of nozzle arrays 1005 constituting the recording element substrate 1002, the shape of the recording element substrate 1002, and the like.

[0029] The areas represented in black are areas printed with the corresponding ink, while the areas represented in white are areas not printed with ink, which is the background color of the printing medium.

[0030] From the pattern matching pattern 1008 for each nozzle array 1005 in each patch 1007, the positional deviation of the nozzle array 1005 due to a manufacturing error in the recording element substrate 1002 on which the patch 1007 was recorded is calculated. Details will be described later with reference to Fig. 8. Note that the pattern matching pattern corresponding to the rectangle 1011 was recorded on a recording element substrate 1002 different from the other pattern matching patterns 1008, and is not used to calculate the positional deviation of the nozzle array 1005 for each recording element substrate 1002.

[0031] The positional deviation between the recording element substrates 1002 and the inclination of the recording head 102 are also calculated using the patches 1007. The positional deviation between the multiple recording element substrates 1002 in the same recording head 102 and the inclination of the recording head 102 are calculated based on a line segment connecting a representative position of the patch 1007 one position inward from the left end and a representative position of the patch 1007 one position inward from the right end. Details will be described later using Figures 9 and 10.

[0032] In the device according to this embodiment, the size of the recording medium 1201 is variable. Therefore, it is possible that the patch 1007 may be recorded with a portion missing at the left or right end of the recording medium 1201. If the patch 1007 is recorded with a length equal to or greater than the detection mark 1019 when a portion of the patch 1007 is missing, the pattern matching pattern 1008 corresponding to the rectangle 1010 is selected as the pattern for calculation at the left end. The pattern matching pattern 1008 corresponding to the rectangle 1011 is selected as the pattern for calculation at the right end.

[0033] Depending on the print head 102, in addition to the patch 1007, a patch 1016 may be printed as a patch for each printing element substrate 1002. The patch 1016 is configured to include a detection mark 1023, an alignment mark 1024, and a pattern matching pattern 1017. Each of the pattern matching patterns 1017 is printed by a plurality of nozzle arrays 1005. The P in the layout 1018 indicates that printing is performed by a plurality of nozzle arrays 1005. Using this patch 1016, the inclination of the print head 102 that printed the patch 1016 is calculated.

[0034] The patches 1007 and 1016 for each recording element substrate 1002 are recorded by shifting the recording timing onto the recording medium by an amount that takes into account the intersection of the manufacturing errors of the nozzle array 1005 and the recording element substrate 1002, so that no overlap of the test charts occurs due to errors.

[0035] The detection marks 1019 and 1023 are used for detecting, by image analysis processing, the patches 1007 and 1016 in the read image that correspond to the recording element substrate 1002. Each of the detection marks 1019 and 1023 is a pattern that is recorded in the shape of a rectangular area.

[0036] In this embodiment, the detection marks 1019, 1023 are recorded by droplets ejected by multiple nozzle arrays 1005. By using multiple nozzle arrays 1005 for recording, even if a non-ejecting nozzle is present in a specific nozzle array 1005, droplets are ejected by nozzles in the other nozzle arrays 1005, making it less likely that defects in the detection pattern will occur due to the non-ejecting nozzle. This makes it possible to stably detect the detection marks 1019, 1023 in the image analysis process.

[0037] The alignment marks 1020, 1024 are used to calculate, by image analysis processing, the reference positions of the analysis areas of the pattern matching patterns 1008, 1017. Each of the alignment marks 1020, 1024 is recorded in the shape of a rectangular area. Each of the alignment marks 1020, 1024 is recorded by droplet ejection from the multiple nozzle arrays 1005 for each of the pattern matching patterns 1008, 1017 corresponding to each nozzle array 1005.

[0038] The pattern matching patterns 1008 and 1017 are also used to detect the positional deviation of the print head 102 by image analysis processing, and the patches 1007 and 1016 are used depending on the ink color of the print head 102 and the type of deviation amount to be calculated.

[0039] Fig. 5(a) is a diagram showing a detailed layout of the pattern matching pattern 1008, and Fig. 5(b) is a diagram showing a detailed layout of the pattern matching pattern 1017. Distance 1101 corresponds to the number of pixels in the vertical direction of the pattern matching pattern 1008, and distance 1102 corresponds to the number of pixels in the horizontal direction of the pattern matching pattern 1008. Distance 1103 corresponds to the number of pixels in the vertical direction of the pattern matching pattern 1017, and distance 1104 corresponds to the number of pixels in the horizontal direction of the pattern matching pattern 1017.

[0040] In this embodiment, the direction of distance 1101 in the pattern matching pattern 1008 is parallel to the transport direction 201, and the direction of distance 1102 is parallel to the nozzle arrangement direction 1001, both of which correspond to 82 pixels in 1200 DPI units. Moreover, the direction of distance 1103 in the pattern matching pattern 1017 is parallel to the transport direction 201, and the direction of distance 1104 is parallel to the nozzle arrangement direction 1001, both of which correspond to 210 pixels in 1200 DPI units. Note that the number of pixels constituting each pattern matching pattern is not limited to the above, and other numbers of pixels may be used.

[0041] FIG. 6 is a diagram for explaining a test chart for calculating the amount of misalignment between nozzle rows, between recording element substrates, and between recording heads according to the present embodiment. In this figure, a test chart 1202 is recorded by the recording head 102 using roll paper on a recording medium 1201. Among the test charts 1202, test charts 1206 to 1213 are test charts for calculating the amount of misalignment between the nozzle rows 1005 and between the recording element substrates 1002, and the amount of inclination of the recording head 102. A test chart 1214 is a test chart for calculating the amount of misalignment between the recording heads 102. As shown in FIG. 4, the nozzle arrangement direction 1001 indicates the nozzle arrangement direction of the recording head 102.

[0042] 1, the inkjet recording apparatus 100 is provided with a plurality of recording heads 102. The recording heads 102 correspond to eight colors, Pr (primer liquid), K (black), C (cyan), M (magenta), Y (yellow), O (orange), V (violet), and G (green), from the upstream in the transport direction of the recording medium 1201. The color order of the recording heads 102 may be changed, and recording heads corresponding to other colors may be added or replaced.

[0043] The scanner device 106 is disposed downstream of the print head 102 in the transport direction of the print medium 1201. The scanner device 106 reads a test chart 1202 printed on the print medium 1201 in order to detect the amount of misalignment of the print head 102.

[0044] Types of head positional deviation are described below. All of them are caused by errors in the formation of the recording element substrate 1002 or nozzles of the recording head 102, or by installation errors of the recording head 102. Types of deviation include misalignment between nozzle rows 1005 for each recording element substrate 1002, misalignment between recording element substrates 1002 for each recording head 102, and misalignment between colors between recording heads 102. When such deviations exist, the ink droplet ejection position deviates from the ideal position, and the quality of the recorded image decreases. Head positional deviation correction is a function that corrects the ink droplet ejection position by changing the ink ejection timing of the recording element substrate 1002, or the nozzle that ejects the ink.

[0045] In this embodiment, misalignment in the nozzle arrangement direction 1001 and the orthogonal direction (transport direction 201) is corrected by changing the ejection timing of each of the recording element substrates 1002 that make up the recording head 102. Misalignment in the nozzle arrangement direction 1001 is corrected by changing the ejection data. Misalignment in the inclination of the recording head 102 is corrected by combining both changes in the ejection timing and changes in the ejection data.

[0046] The test chart 1202 shown in FIG. 6 is a test chart for correcting head positional deviation of the print head 102. The test charts 1206 to 1214 are test charts for eight heads, and each test chart is used to detect the amount of positional deviation of the corresponding print head 102. Using these test charts 1206 to 1214, the amount of deviation between the nozzle rows 1005 for each print element substrate 1002, the amount of deviation between the print element substrates 1002 for each print head 102, and the amount of inclination of the print head 102 are calculated. In this embodiment, the test charts 1206 to 1213 are test charts corresponding to one of the print heads 102 of O, G, V, K, C, M, Y, and Pr. The number of test charts for the print heads 102 included in the test chart 1202 may be increased or decreased from eight heads, and the order of the test charts may be changed. Therefore, the number of test charts may vary depending on the number of print heads 102 to be tested. Further, the test chart 1214 is a test chart for calculating the amount of color misregistration between the recording heads 102, and is recorded by using all the recording heads 102. The test chart 1214 will be described later with reference to FIG.

[0047] In this embodiment, the test chart 1215 is an enlarged view of a portion of the test chart 1209 corresponding to the ink color K. In the test chart 1215, the areas represented in black are areas printed with the corresponding ink. Moreover, the areas represented in white are areas that are the base color of the printing medium 1201 and are areas not printed with ink. Moreover, for each printing element substrate 1002 constituting the printing head 102, a patch 1007 corresponding to the printing element substrate 1002 is printed linearly so as to be aligned parallel to the nozzle arrangement direction 1001.

[0048] In this embodiment, each of the test charts 1206 to 1208 and 1210 to 1212 corresponding to the ink colors O, G, V, C, M, and Y has a configuration similar to that of the test chart 1209.

[0049] In this embodiment, the test chart 1216 is an enlarged view of a part of the test chart 1211 corresponding to the primer liquid. The test chart 1216 is configured so that the patches 1016 shown in FIG. 4 are linearly printed on each recording element substrate 1002 so as to be aligned parallel to the nozzle arrangement direction 1001.

[0050] It should be noted that the present invention is not limited to the example shown in FIG. 6, and the correspondence between each test chart and ink color may be changed depending on the type of recording head 102.

[0051] FIG. 7 is a diagram showing the correspondence between the test chart 1214 and the recording element substrate 1002 for performing color misalignment correction calculation between the recording heads 102. The test charts for each color are partially omitted. The test chart 1301 is the test chart 1214 for calculating the position error between the recording heads 102. In the test chart 1301, the pattern matching patterns 1008 and 1017 are printed by the recording heads 102 of each ink color shown in the layout 1302. In each recording head 102, one recording element substrate 1002 is selected for use in printing the test chart 1301. Here, the recording element substrate 1002 used to print the test chart 1301 by each recording head 102 is the recording element substrate 1002 that is located at the same position in the nozzle arrangement direction 1001 as the recording element substrate 1303. That is, regardless of which recording head 102 is used, the pattern matching pattern 1008 is printed using the recording element substrate 1002 that is located at the same position in the nozzle arrangement direction 1001 as the recording element substrate 1303. In the test chart 1301 , the areas expressed in black are areas printed in the corresponding ink color, and the areas expressed in white indicate the white paper (base) areas of the printing medium 1201 .

[0052] In this embodiment, the pattern matching patterns 1008 are used for the colored inks K, C, M, Y, O, G, and V. As shown in the layout 1302, the pattern matching patterns 1008 at both ends are printed using the print head 102 corresponding to the ink color K as a reference head, and the positional deviation of the print head 102 corresponding to each ink other than the ink color K is calculated. In the layout 1310, the positional deviation amount of the print head 102 corresponding to each ink of C, M, and Y can be calculated using the print head 102 corresponding to the ink color K as a reference head. In the layout 1311, the positional deviation amount of the print head 102 corresponding to each ink of O, G, and V can be calculated using the print head 102 corresponding to the ink color K as a reference head. By printing the layout 1310 and the layout 1311 multiple times, it is possible to calculate the positional deviation multiple times for the print head 102 corresponding to each ink. By taking the average value of the positional deviation calculation results multiple times as the positional deviation of each print head 102, the influence of the positional deviation error due to the print timing is reduced, and more accurate positional deviation can be obtained. The number of times the layouts 1310 and 1311 are repeatedly printed may be determined according to the required accuracy of the position shift calculation, and may be 1. The repetition of the layouts 1310 and 1311 is omitted in the drawing.

[0053] In this embodiment, the positional deviation of the print head 102 corresponding to the primer liquid is calculated using a pattern matching pattern 1017. As shown in layout 1302, the print head 102 corresponding to the ink color K is printed as a reference head, and the positional deviation of the print head 102 corresponding to the primer liquid is calculated. By printing the layout 1312 multiple times, it is possible to calculate the positional deviation multiple times for the print head 102 corresponding to the primer liquid, as with the colored inks. The number of times the layout 1312 is printed repeatedly may be determined according to the desired accuracy of the positional deviation calculation, and may be one time. The repetition of the layout 1312 is omitted in the figure.

[0054] The pattern matching pattern of the reference head uses a pattern similar to the pattern matching pattern of the print head 102 for which the deviation is to be calculated. Furthermore, the pattern matching patterns corresponding to the colors are not limited to those shown in Fig. 5 and Fig. 7, and different patterns may be used.

[0055] The test chart 1301 used to calculate the color shift between the print heads 102 is printed so that the print timing on the print medium 1201 exceeds the maximum color shift amount of the print heads 102. By shifting the print timing of each print head 102 in this way, overlapping of the test charts is prevented.

[0056] (Calculating the amount of misalignment between nozzle rows) 8 is a diagram showing a method for calculating the amount of misalignment between nozzle arrays. As described above, in this embodiment, 16 nozzle arrays 1005 are arranged in one recording element substrate 1002. Here, the first nozzle array 1005 counting from the downstream side in the transport direction 201 is designated as R0, and the last nozzle array 1005 is designated as R15.

[0057] A method for calculating the amount of misalignment between nozzle arrays 1005 using a read image of a patch 1007 printed according to a layout 1012 will be described. In the layout 1012, a rectangle containing a numerical value n (n≧0) indicates the nozzle array 1005 that printed the pattern matching pattern 1008 at that position. For example, the pattern matching pattern 1008 corresponding to rectangle 1405 indicates that it was printed using the R0 nozzle array 1005. Hereinafter, the pattern matching pattern using the Rn nozzle array 1005 and the rectangle indicating the printing position of that pattern will be referred to as the "Rn pattern."

[0058] 8A, the layout 1012 is divided into four regions 1401 to 1404. In the region 1401, R0 patterns 1405 and 1406 are used as references. Similarly, in the regions 1402 to 1404, R0 patterns 1407 and 1408, R0 patterns 1409 and 1410, and R0 patterns 1411 and 1412 are used as references, respectively. In each of the regions 1401 to 1404, the amount of deviation from the pattern matching patterns (R1 patterns to R15 patterns) using the other nozzle arrays 1005 is calculated using the two R0 patterns as references.

[0059] A method for calculating the amount of deviation between the nozzle array 1005 of R0 and the nozzle array 1005 of R9 will be described as an example with reference to FIG. 8B. The R0 pattern 1414 corresponds to the R0 pattern 1405 in the area 1401, and the R0 pattern 1415 corresponds to the R0 pattern 1406 in the area 1401, and each of these is a reference pattern for pattern matching. The R9 pattern 1416 is the R9 pattern recorded in the area 1401. When the nozzle array 1005 of R0 and the nozzle array 1005 of R9 are used to record the respective pattern matching patterns, if there is no deviation in the landing position of the ejected ink, the R9 pattern is recorded on the straight line connecting the R0 pattern 1414 and the R0 pattern 1415. The R9 pattern recorded at the ideal position without any deviation in the landing position is indicated by the R9 pattern 1418. On the other hand, the actual recording position of the R9 pattern is indicated by the R9 pattern 1416.

[0060] The amount of deviation between the R9 pattern 1416 and the R9 pattern 1418 is the amount of positional deviation of the R9 nozzle row 1005 relative to the R0 nozzle row 1005. The horizontal component of the deviation is deviation 1417, and the vertical component is deviation 1419. The deviation 1419 is the length of a perpendicular line drawn from the R9 pattern 1416 to a line connecting the R0 pattern 1414 and the R0 pattern 1415. Therefore, the deviation 1419 can be calculated from the positions of the R0 pattern 1414, the R0 pattern 1415, and the R9 pattern 1416. Similarly, the deviation 1417 can also be found from these positions.

[0061] By applying the method described above, the amount of deviation of the R1 to R15 patterns can be calculated using the R0 pattern as a reference, and the amount of positional deviation of the nozzle arrays 1005 of R1 to R15 relative to the nozzle array 1005 of R0 can be obtained.

[0062] (Calculation of the amount of misalignment between recording element substrates) Fig. 9 is a diagram for explaining a method for calculating the amount of misalignment between the recording element substrates 1002. In this embodiment, the first recording element substrate 1002 counting from the left side on the paper surface of Fig. 9 in the nozzle arrangement direction 1001 is C0, and the last recording element substrate 1002 is C16. A method for calculating the amount of misalignment between the recording element substrates 1002 using a read image of the patch 1007 printed in accordance with the layout 1012 of the patch 1007 will be explained with reference to the diagram.

[0063] Patches 1501 to 1503 shown in Fig. 9(a) are schematic diagrams of patches 1007 printed according to the layout 1012 shown in Fig. 4 using three different printing element substrates 1002 in the same printing head 102. Depending on the size of the printing medium 1201 and transport error, some printing element substrates 1002 do not print on the printing medium 1201. Hereinafter, a patch printed on the printing medium 1201 by a different printing element substrate 1002 will be referred to as a "Cn patch" using Cn (n ≥ 0) indicating which of the multiple printing element substrates 1002 for each printing head 102 it is.

[0064] The patch 1501 is a patch 1007 recorded by the recording element substrate 1002 of C1, which is one patch to the right from the leftmost end, among the multiple patches 1007 recorded by one recording head 102. The recording element substrate 1002 that records the patch 1501 varies depending on the size of the recording medium 1201 and the like. In this embodiment, the patch 1501 is the C1 patch. The patch 1502 is a patch 1007 recorded by the recording element substrate 1002 of C15, which is one patch to the left from the rightmost end, among the patches 1007 recorded by the recording head 102 that recorded the C1 patch. In this embodiment, the patch 1502 is the C15 patch. The patch 1503 is a patch 1007 recorded by the recording element substrate 1002 that is the target of the calculation of the deviation amount between the recording element substrates 1002, among the patches 1007 recorded by the recording head 102 that recorded the C1 patch and the C15 patch. Here, as an example, the recording element substrate 1002 C8 located at the center of the recording head 102 will be described.

[0065] A coordinate point 1507 shown in FIG. 9B is the midpoint of a line segment connecting two R0 patterns in the pattern matching pattern 1008 array aligned in the nozzle array direction 1001 of the patch 1501 (C1 patch), and is the representative position of the C1 patch. A coordinate point 1508 is the midpoint of a line segment connecting two R0 patterns in the pattern matching pattern 1008 array aligned in the nozzle array direction 1001 of the patch 1502 (C15 patch), and is the representative position of the C15 patch. The recording element substrate 1002 on which these C1 patch and C15 patch are recorded is a reference for calculating the amount of deviation between the recording element substrates 1002. A coordinate point 1511 is the midpoint of a line segment connecting two R0 patterns in the pattern matching pattern 1008 array aligned in the nozzle array direction 1001 of the patch 1503 (C8 patch), and is the representative position of the C8 patch. Here, the recording element substrate 1002 of C8 is the object for calculating the amount of misalignment between the recording element substrates 1002.

[0066] In order to calculate the amount of deviation between the recording element substrates 1002, first consider the case where there is no deviation in the landing position when each patch 1007 is recorded at the representative position of each of the C1, C8, and C15 patches. In this case, the representative position of the C8 patch when it is recorded at an ideal position without deviation in the landing position of the ejected ink on a straight line connecting the coordinate point 1507 and the coordinate point 1508, that is, the midpoint of the line segment connecting the coordinate point 1507 and the coordinate point 1508, is indicated by the coordinate point 1512. On the other hand, the actual representative position calculated from the C8 patch on the read image is indicated by the coordinate point 1511. The amount of deviation between the coordinate point 1511 and the coordinate point 1512 is divided into a component parallel to the reference line connecting the coordinate point 1507 and the coordinate point 1508 and a component perpendicular to the reference line. The component parallel to the reference line is the distance between the reference line and the actual representative position of the C8 patch, and is set as the amount of deviation 1514. The amount of deviation 1514 is the length of a perpendicular line drawn from the coordinate point 1511 to the reference line. Therefore, the amount of deviation 1514 can be found from the coordinate points 1507, 1508, and 1511. The component perpendicular to the reference line is the distance between a line that passes through the coordinate point 1511 and is perpendicular to the reference line, and a line that passes through the coordinate point 1512 and is perpendicular to the reference line, and is called the amount of deviation 1513. Therefore, the amount of deviation 1513 can be found from the coordinate points 1507, 1508, 1511, and 1512.

[0067] By applying the method described above, it is possible to use two recording element substrates 1002 as references and obtain the amount of misalignment of other recording element substrates 1002 sandwiched between the reference recording element substrates 1002. However, the method of calculating the amount of misalignment of the recording element substrates 1002 C0 on the left end and C16 on the right end, which are located further to the end than the two references (C1 and C15 in the example shown), is different.

[0068] For example, since the left end of the two reference recording element substrates 1002 is C1 and the right end is C15, the representative position of the C0 patch at the left end is the coordinate point 1511 to be adjusted, and the representative position of the C16 patch at the right end is the coordinate point 1511 to be adjusted. As with the others, the representative position of the C16 patch at the right end is the midpoint of the line segment connecting two R0 patterns in the pattern matching pattern 1008 array aligned in the nozzle arrangement direction 1001. On the other hand, the representative position of the C0 patch at the left end is the position of the pattern matching pattern corresponding to the rectangle 1011 recorded by the recording element substrate 1002 of the C1 adjacent to the right. This is because there is a possibility that the recording element substrate 1002 at the end can only partially record the layout 1012 on the recording medium 1201.

[0069] Depending on the length of the nozzle array arrangement direction 1001 of the recording medium 1201, there is a possibility that the C0 or C16 recording element substrate 1002 may be present outside the recording element substrate 1002 at the left end or the recording element substrate 1002 at the right end of the range to be recorded. In such a case, the C0 or C16 recording element substrate 1002 cannot be recorded on the recording medium 1201, and therefore it is impossible to detect the C0 patch or C16 patch in its complete form. Therefore, the outer recording element substrate 1002 on the left end side uses the deviation amount of the substrate immediately to the right as a correction value. Similarly, the outer recording element substrate 1002 on the right end side uses the deviation amount of the substrate immediately to the left as a correction value.

[0070] (Calculating the amount of inclination of the recording head) 10, a method for calculating the amount of tilt of the print head 102 using a scanned image of a patch 1007 printed according to a layout 1012 will be described. The amount of tilt of the print head 102 is calculated using a patch 1007 similar to the patch used to calculate the amount of deviation between the printing element substrates 1002. The amount of tilt correction of the print head 102 is defined as the amount of deviation from the average tilt of all print heads, and the amount of tilt correction is calculated for each of all print heads.

[0071] Patches 1501 and 1502 shown in Fig. 10(a) are a C1 patch and a C15 patch recorded by the same recording head 102. Patches 1504 and 1505 shown in Fig. 10(b) are a C1 patch and a C15 patch recorded by a different recording head 102 from the recording head 102 that recorded patches 1501 and 1502, but are the C1 patch and the C15 patch recorded by the same recording head 102. Similar to patches 1501 and 1502, coordinate point 1509 which is the representative position of the C1 patch and coordinate point 1510 which is the representative position of the C15 patch are obtained from patches 1504 and 1505.

[0072] 10C is a diagram for explaining a method for calculating the tilt amount of the print head 102. First, the tilt amount of each print head 102 is calculated. Coordinate points 1507 and 1508 are representative positions of the C1 patch and the C15 patch recorded by the reference recording element substrate 1002 located one position inside the left and right ends of the print head 102A that recorded the patch 1501 and the patch 1502. Angle 1516 indicates the angle (minor angle) formed by the line segment connecting the coordinate points 1507 and 1508 and an ideal line that does not cause a landing position shift due to the tilt of the print head 102A, and indicates the tilt amount of the print head 102A.

[0073] Similarly, the amount of tilt of the recording head 102B is calculated. Coordinate points 1509 and 1510 are representative positions of the C1 patch and the C15 patch recorded by the recording element substrate 1002 that serves as the reference on the left and right end sides of the recording head 102B. Angle 1517 indicates the angle (minor angle) formed by the line segment connecting coordinate points 1509 and 1510 and an ideal line that does not have a landing position deviation due to the tilt of recording head B, and indicates the amount of tilt of the recording head 102B. Although not shown, the amounts of tilt can be obtained similarly for all other recording heads 102.

[0074] Finally, calculate the amount of calculation for tilt correction for each print head 102. The amount of tilt correction based on the relative amount of tilt of each print head 102 can be calculated by the following formula. The amount of tilt of the print head 102 here is represented by an angle.

[0075] (Tilt correction amount for each recording head 102) = (average of tilt of all recording heads 102) - (tilt of each recording head 102) If angle 1518 shown in FIG. 10B is the average tilt of all print heads 102, then the amount of tilt correction for print head 102A, for example, is the value obtained by subtracting angle 1516 from angle 1518.

[0076] By applying the method described above, the amount of tilt correction for each print head 102 can be calculated relative to the average tilt of all print heads 102 .

[0077] (Calculation of the amount of misalignment between recording heads) 11 is a diagram for explaining a method for calculating the amount of misalignment between print heads 102. In this embodiment, the first print head 102 counting from the upstream side in the transport direction 201 is the print head Pr that uses primer liquid. The subsequent print heads 102 are referred to as print head K, print head C, print head M, print head Y, print head O, print head V, and print head G, respectively, according to the colors of the colored inks used. A method for calculating the amount of misalignment between print heads 102 (hereinafter referred to as "inter-color misalignment") using a read image of a test chart 1301 printed using print heads 102 corresponding to multiple ink colors according to a layout 1302 will be explained.

[0078] A test chart 1301 shown in FIG. 11(a) is a test chart 1214 used to calculate the amount of misalignment between colors. The test chart 1301 is printed using a printing element substrate 1303 at a predetermined position of the print head 102 corresponding to a predetermined color shown in a layout 1302. In this embodiment, C8 is used as the printing element substrate 1303 at the predetermined position. In this embodiment, the pattern matching patterns 1601 to 1606 are patterns printed by the printing element substrate 1303 of C8 of the print head K, which is the reference head (hereinafter, referred to as the K pattern). The other patterns with letters indicating the ink colors are patterns printed by the print head 102 that is the target of the calculation of the misalignment between the print heads 102. In this embodiment, these patterns are C, M, Y, O, V, G, and Pr patterns (hereinafter, referred to as the C pattern, etc.), but the number of ink colors may be increased or decreased. In this embodiment, C, M, Y, O, V, and G are printed using the configuration of the pattern matching pattern 1008 shown in Fig. 5. K patterns 1601 to 1604 that serve as references for these are also printed using the configuration of the pattern matching pattern 1008. On the other hand, Pr patterns (hereinafter referred to as Pr patterns) are printed using the configuration of the pattern matching pattern 1017 shown in Fig. 5 in this embodiment. K patterns 1605 and 1606 that serve as references for these are also printed using the configuration of the pattern matching pattern 1017.

[0079] In this embodiment, when calculating the amount of deviation between print head K (reference head) and print heads 102 of ink colors other than K, the same method is used for each print head 102. Here, as an example, a method for calculating the amount of deviation between print head K and print head V will be described. K pattern 1620 shown in FIG. 11(b) corresponds to K pattern 1603, and K pattern 1621 corresponds to pattern 1604. These are patterns for pattern matching printed by C8 of the print head K that serves as the reference. V pattern 1622 corresponds to V pattern 1617, and is a pattern for pattern matching printed by the printing element substrate 1002 of C8 of print head V, and is a pattern for pattern matching printed by the print head 102 for which the amount of deviation is to be calculated.

[0080] If there is no deviation in the landing position of the ejected ink, the V pattern printed by the print head V is printed on a reference line connecting K pattern 1620 and K pattern 1621. The position of the V pattern when printed at an ideal position without deviation in the landing position of the ejected ink is shown as V pattern 1624. Meanwhile, the actual position of the V pattern is shown as V pattern 1622.

[0081] In this embodiment, the amount of deviation between the V pattern 1622 in the scanned image and the V pattern 1624 at the ideal position is divided into a component perpendicular to the reference line and a component parallel to the reference line. Of the deviations between the V patterns 1622 and 1624, the component perpendicular to the reference line is set as deviation 1625. This deviation 1625 is the length of a perpendicular line drawn from the V pattern 1622 to the reference line. Therefore, the deviation 1625 can be obtained from the positions of the K pattern 1620, the K pattern 1621, and the V pattern 1622. Of the deviations between the V patterns 1622 and 1624, the component parallel to the reference line is set as deviation 1626. This deviation 1626 is the distance between a line passing through the V pattern 1622 and perpendicular to the reference line and a line passing through the V pattern 1624 and perpendicular to the reference line. Therefore, the deviation amount 1626 can be found from the positions of the K pattern 1620, the K pattern 1621, the V pattern 1622, and the V pattern 1624. In the head position deviation correction in this embodiment, the correction amount is calculated in both directions for the deviation amount 1625 and the deviation amount 1626.

[0082] By applying the method described above, the amount of color misalignment between the print head K, which is the reference head, and the print heads 102 of ink colors other than K can be obtained.

[0083] (Mark detection process) FIG. 12 is a diagram for explaining a mark detection process corresponding to the recording element substrate 1002. In this embodiment, a process for detecting a detection mark for each patch 1007 corresponding to each recording element substrate 1002 from a read image of a test chart 1202 for calculating the amount of deviation will be explained. FIG. 12 shows a patch corresponding to each recording element substrate 1002, which corresponds to the patch 1007 shown in FIG. 4. In this embodiment, there are two types of patches corresponding to each recording element substrate 1002, namely, patches 1007 and 1016 in FIG. 4, but the detection process is performed in the same manner for both. The detection process is also similar for the test chart 1301 shown in FIG. 7 for calculating the position error between the recording heads 102. Here, the patch 1007 shown in FIG. 4 is used as an example for explanation.

[0084] The mark detection process is roughly divided into three steps. In the first step, the detection mark 1019 is detected. Based on the detected position of the detection mark 1019, the position of one patch 1007 on the recording element substrate 1002 is estimated. In the second step, based on the estimated position of the patch 1007 obtained in the first step, an alignment mark 1703 for estimating the position of the pattern matching pattern 1008 is detected. The alignment mark 1703 is a mark similar to the alignment mark 1020 in the patch 1007 shown in FIG. 4. Since this alignment mark 1703 is recorded near each pattern matching pattern 1008, the position of the corresponding pattern matching pattern 1008 is estimated from the detected position of the alignment mark 1703. In the third step, pattern position detection is performed using pattern matching based on the estimated position of the pattern matching pattern 1008 in the second step.

[0085] The process of detecting the detection mark 1019 in the first step will be described. This process uses the luminance value of the channel that has the highest density for the ink color of the recording head 102 of the pattern to be detected, out of the three RGB channels of the read image that the scanner device 106 can read. For example, the channel with the highest density is the R channel when C (cyan), the G channel when M (magenta), and the B channel when Y (yellow). Note that in the case of an ink color that has high density in all channels, such as K (black), any one of the channels is specified and used.

[0086] Reference numeral 1705 denotes an enlarged view of a portion of the detection mark 1019. The detection mark 1019 is detected based on the average density of a predetermined region of the read image. A detection mark detection region 1706 is a region from which the average density is acquired. If the average density acquired in the detection mark detection region 1706 is equal to or greater than a predetermined density, the region is identified as a detection mark region, and its center position is designated as a detection mark detection position 1707. The range of the detection mark detection region 1706 and the predetermined density used as a threshold value may be changed.

[0087] Next, the upper left end position and the upper right end position of the detection mark 1019 are detected. 1708 is an enlarged view of the periphery of the upper left end of the detection mark 1019, and 1710 is an enlarged view of the periphery of the upper right end. An area having a predetermined density or more is scanned from the detection mark detection position 1707, and the upper left end of the area having a predetermined density or more is set as the upper left end position 1709 of the detection mark. Similarly, the upper right end of the area having a predetermined density or more is set as the upper right end position 1711 of the detection mark. The detection range of the alignment mark 1703 is estimated by calculating the density center of the predetermined area from the position determined based on the upper left end position 1709 of the detection mark as the starting point. The detection range of the alignment mark 1703 can be estimated by detecting the detection mark 1019. The detection process of the alignment mark 1703 is also similar to the detection process of the detection mark 1019, and an area having a predetermined density or more is scanned, and the position of the alignment mark 1703 is detected by calculating the density center of the area.

[0088] Next, the position of the pattern matching pattern 1008 is estimated. An area 1704 is an area indicating the upper left end position of the pattern matching pattern 1008. The detection result of the detection mark 1019 is also used to determine which recording element substrate 1002 of which recording head 102 the pattern matching pattern 1008 corresponds to. After the rough position of the pattern matching pattern 1008 is estimated by the above process, a position detection process including a pattern matching process is performed to detect the final position on the read image. The position of the pattern matching pattern 1008 on the read image is the position for calculating the distance used to calculate various amounts of deviation in head position deviation correction. The various amounts of deviation here include the manufacturing error between the nozzle rows 1005, the manufacturing error between the recording element substrates 1002, the inclination of the recording head 102, and the position deviation between the recording heads 102.

[0089] (Images captured by multiple sensors) 13 shows an example of read images of a test chart 1202 acquired by two sensors 202A and 202B of the scanner device 106 while the recording medium 1201 is conveyed along the conveying direction 201. Read images 2001 and 2002 are simplified representations of the test chart read by the sensors 202A and 202B, which are CCD line sensors, respectively. When the width of the recording medium 1201 covers both the imaging areas of the sensors 202A and 202B, the read image of the test chart 1202 consists of a read image obtained from the sensor 202A and a read image obtained from the sensor 202B.

[0090] Here, a method for obtaining a read image using the scanner device 106 will be described. Light is reflected by a lamp (not shown) of the scanner device 106 when it hits the recording surface of the recording medium 1201, and the reflected light is converged on the sensor 202A or 202B through a lens. Each sensor 202 that receives the reflected light outputs an analog signal having an intensity according to the amount of light, and the signal output from each sensor 202 is converted into a digital signal by the scanner control unit 411. In this way, the recording medium 1201 is first read in a line shape extending in the sensor row direction (the direction of the arrow X shown in FIG. 13) by the CCD line sensor. This line reading is repeated while moving in the recording medium conveying direction 201 that intersects (ideally perpendicular to) the sensor row direction X, and the entire test chart 1202 is read. The digital signals obtained by reading are accumulated to obtain a read image of the entire recorded test chart 1202. The scanned images of the test chart 1202 obtained in this manner are scanned images 2001 and 2002, and in this embodiment, the amount of deviation of the ink landing position from the ideal position is calculated based on these multiple scanned images.

[0091] In FIG. 13, in each read image, the patch 1007 or 1016 for each recording element substrate 1002 constituting the test charts 1206, 1207, and 1213 is represented by a rectangle containing a number n. That is, the rectangle containing a number n indicates that the patch is recorded by the recording element substrate 1002 of Cn. For example, the patch 2003 is a C8 patch of the recording head 102 of the colored ink O. In the figure, the test charts 1202 of some of the recording heads 102 are omitted, and the overall image of the test chart 1202 differs depending on the number of recording heads 102 and the color combination. In addition, in each read image, there is a test chart 1214 below the C8 patch for calculating the amount of color shift between the recording heads 102.

[0092] In addition, the sensors 202A and 202B are arranged in a staggered manner, so that they are spaced apart from each other along the transport direction 201. During scanning, the transport speed of the recording medium 1201 may temporarily fluctuate due to unexpected events such as flapping of the paper, turbulence of the surrounding air currents, and vibration of the device. In such cases, the scan data expands or contracts along the transport direction 201. At this time, since the sensors 202A and 202B are spaced apart in the transport direction, the ranges on the scan data where expansion or contraction occurs are different between the scan data of the sensor 202A and the scan data of the sensor 202B. Therefore, even if the same test chart is scanned, the effects of expansion or contraction appear in different regions of the test chart 1202 on the read image obtained from the sensor 202A and the test chart 1202 on the read image obtained from the sensor 202B. In the example shown in FIG. 13, the effect of the transport speed fluctuation, which causes the test chart 1207 to expand along the transport direction 201, appears in the read image obtained from the sensor 202A. On the other hand, in the read image obtained by the sensor 202B, the influence of the transport speed fluctuation, which extends the test chart 1206 along the transport direction 201, appears. In order to see the magnitude of the influence of the transport speed fluctuation, for example, consider a case where the transport speed of the recording medium is 20 m / min, i.e., 333.33 mm / sec, the reading resolution is 600×600 dpi, and the length of the patch 1007 in the transport direction is 10.50 mm. In this case, if the transport speed temporarily drops by 5% to 316.66 mm / sec, the length of the patch 1007 in the transport direction read during this transport speed fluctuation is 11.025 mm. The change in the length of the patch 1007 before and after the transport speed fluctuation is 11.025-10.50=+0.525 (mm), which is +12 pixels / 600 dpi.

[0093] Since the sensors 202A and 202B are arranged in a staggered configuration, the read images 2001 and 2002 have areas that are read by both sensors. Hereinafter, this area is referred to as an overlapping area, and the other areas are referred to as non-overlapping areas. In the read image 2001, an area 2004 is the overlapping area, and in the read image 2002, an area 2005 is the overlapping area. The width of the overlapping area varies depending on the degree of overlap between the sensors, but in this embodiment, the width must be such that it can include a pattern that can calculate the expansion / contraction ratio between the read images. The pattern that can calculate the expansion / contraction ratio between the read images is, for example, a patch such as pattern 2003 that is printed by one printing element substrate 1002 of one printing head 102. The calculation of the expansion / contraction ratio between the read images using the patch located in the overlapping area and the details of its use will be described later.

[0094] (Calculation of deviation based on test chart divided into multiple scanned images) A method for calculating the amount of misalignment between nozzle rows 1005, between recording element substrates 1002, and between recording heads 102, and the amount of inclination of the recording heads 102 from a read image in this embodiment will be described below.

[0095] The method for correcting the positional deviation of the print head 102 has been described above. However, when the test chart 1202 is obtained by being divided into a plurality of read images as shown in Fig. 13 by being read by a plurality of sensors 202, this point must be taken into consideration. In particular, when calculating the deviation between the print element substrates 1002, the deviation between the print element substrates 1002 sandwiched between the print element substrates 1002 serving as the reference is calculated with respect to a reference line connecting the print element substrates 1002 serving as the reference. Since the print element substrate 1002 one position inside from both ends serves as the reference, C1 and C15 serve as the reference in the test chart 1202 shown in Fig. 13. However, when the test chart 1202 is divided into a plurality of read images as shown in Fig. 13, C1 is included only in the read image 2001, and C15 is included only in the read image 2002. That is, since each read image has only one patch corresponding to the reference recording element substrate 1002, it is not possible to obtain a reference line connecting the reference recording element substrates 1002 from only one read image, and it is not possible to calculate each amount of deviation or tilt. For example, it is possible to obtain a reference line connecting the reference recording element substrates 1002 by combining two read images 2001 and 2002 into one image using the overlapping area. However, the larger the read image is, the larger the amount of data of the read image itself becomes, which increases the load on the CPU processing and may reduce the processing speed other than the read image analysis. In addition, in order to combine the two read images 2001 and 2002, a process is also required to match the difference in tilt and color between the sensors 202A and 202B. Therefore, it is more desirable to be able to calculate each amount of deviation and tilt without combining the read images 2001 and 2002. Therefore, in this embodiment, the combination of the multiple read images 2001 and 2002 obtained from the multiple sensors 202A and 202B is not performed. The position information of the reference recording element substrate 1002 in the test chart 1202 on one of the read images is multiplied by the corresponding expansion / contraction rate to correct the distance between the corresponding identical patterns so that they become equal. Then, a reference line is obtained based on the corrected position information and the corresponding position information of the uncorrected reference recording element substrate 1002 on the other read image.Using the reference lines thus obtained, the amounts of misalignment between the nozzle rows 1005, between the printing element substrates 1002, and between the printing heads 102, as well as the amount of inclination of the printing heads 102 are calculated.

[0096] 14 is a flow chart showing the calculation of the amount of deviation in this embodiment. Each step will be explained below.

[0097] In S3001, the scanner device 106 reads the test chart 1202 recorded on the recording medium 1201. The timing when the scanner device 106 starts reading the test chart 1202 may be when a predetermined time has elapsed since the start of recording the test chart 1202. Alternatively, it may be when a predetermined amount of the recording medium has been transported since the end of recording the test chart 1202. The timing when reading ends is when a predetermined number of lines have been read from the start of reading.

[0098] In S3002, the print controller 402 performs a misalignment calculation process 1 on the first read image 2001, which is the read image 2001 read by the sensor 202A in S3001. The misalignment calculation process 1 is a process for calculating the misalignment between the nozzle rows 1005, the misalignment between the print heads 102, and the expansion / contraction ratio between the read images, and details of the process will be described later with reference to FIG.

[0099] In S3003, the print controller 402 performs a misalignment amount calculation process 1 on the second scanned image 2002, which is the scanned image 2002 scanned by the sensor 202B in S3001. The misalignment amount calculation process 1 is the same process as S3002.

[0100] In S3004, the print controller 402 performs a misalignment calculation process 2 for the first read image 2001 and the second read image 2002. The misalignment calculation process 2 is a process for calculating the misalignment between the recording element substrates 1002 based on a reference line corrected based on the expansion / contraction ratio between the read images 2001 and 2002 and the tilt amount of the recording head 102, and the details of the process will be described later with reference to FIG.

[0101] In another embodiment, each step of the above-mentioned deviation amount calculation flow may be performed by the host device 500.

[0102] 15 is a diagram showing a processing flow of the deviation amount calculation process 1. Each step of the deviation amount calculation process 1 will be described with reference to FIG.

[0103] In S3101, the print controller 402 detects patches corresponding to each recording element substrate 1002 from the first and second read images of the test chart 1201 read in S3001. The process of detecting patches corresponding to each recording element substrate 1002 can be performed by the method described with reference to FIG.

[0104] In S3102, the print controller 402 determines whether there is a test chart corresponding to a print head 102 for which analysis has not been performed on the amount of misalignment between the printing element substrates 1002 and the amount of misalignment between the nozzle arrays 1005. The test charts corresponding to the print head 102 are the test charts 1206-1213 shown in Figures 6 and 13. If there is a test chart corresponding to a print head 102 for which analysis has not been performed, the process proceeds to S3103, and if there is no patch corresponding to a print head 102 for which analysis has not been performed, the process proceeds to S3108.

[0105] In S3103, the print controller 402 selects one test chart corresponding to the print head 102 for which analysis of various amounts of misalignment has not been performed, for example, starting from the test chart 1206.

[0106] In S3104, the print controller 402 determines whether or not there is a patch 1007 or 1016 corresponding to the recording element substrate 1002 for which the analysis of the amount of misalignment between the nozzle rows 1005 has not been performed in the selected test chart. If there is a patch 1007 or 1016 corresponding to the recording element substrate 1002 for which the analysis has not been performed, the process proceeds to S3105, and if there is no patch 1007 or 1016 corresponding to the recording element substrate 1002 for which the analysis has not been performed, the process proceeds to S3107. The patch corresponding to the recording element substrate 1002 to be analyzed is the patch 1007 or 1016 for the recording element substrate 1002 that exists in the read images 2001 and 2002 read in S3101, and the patch that exists near the center of the overlapping area is set as the boundary. If the patch that is the boundary is set as the C8 patch, the patch C0 to C8 in the read image 2001 and the patch C8 to C16 in the read image 2002 are set as the target of analysis. The patch 1007 or 1016 that is the boundary may be any patch that exists in the overlapping area, and in the case of the scanned image 2001 and the scanned image 2002, the boundary may be a C7 patch or a C9 patch.

[0107] In S3105, the print controller 402 selects one patch corresponding to the recording element substrate 1002 to be analyzed, starting from C0 in the case of the read image 2001, for example.

[0108] In S3106, the print controller 402 calculates the amount of misalignment between the nozzle arrays 1005 in the target recording element substrate 1002 by using a read image including the patch 1007 or 1016 corresponding to the selected recording element substrate 1002 to be analyzed. The method for calculating the amount of misalignment between the nozzle arrays 1005 in this embodiment is the method described with reference to FIG. 8. If the selected patch to be analyzed is the patch 1007, analysis is performed, and if the selected patch to be analyzed is the patch 1016, analysis is skipped. For the amount of misalignment between the nozzle arrays of C8 that is analyzed in both the read image 2001 and the read image 2002, the calculation result from one of the read images is used.

[0109] In S3107, the print controller 402 estimates the position of the recording element substrate 1002 to be analyzed. The coordinates of the recording element substrate 1002 are the midpoint of the line segment connecting two pattern matching patterns 1008 printed using R0 of each recording element substrate 1002, such as the coordinate point 1507 described with reference to Figs. 9 and 10. For the position of the recording element substrate 1002 of C8 to be analyzed in both the read image 2001 and the read image 2002, the position in the coordinate system of the read image 2001 and the position in the coordinate system of the read image 2002 are estimated separately. After S3107, the process returns to S3103, and the recording element substrate 1002 that has not been analyzed is treated as the recording element substrate 1002 to be analyzed, and the processes of S3106 and S3107 are performed on the patches corresponding to all recording element substrates 1002 in the target print head 102.

[0110] In S3108, the print controller 402 calculates the amount of misalignment between the print heads 102 using a test chart 1214 for measuring the amount of misalignment between the print heads 102 in the read images 2001 and 2002. The method for calculating the amount of misalignment between the print heads 102 in this embodiment is as described with reference to Fig. 11. Since the test chart 1214 is included in both the read images 2001 and 2002, the calculation result from one of the read images is used to determine the amount of misalignment between the print heads 102.

[0111] In S3109, the print controller 402 calculates the expansion / contraction ratio of the patches 1007 and 1016 corresponding to the recording element substrate 1002 between the read images for each text chart 1202. A method for calculating the expansion / contraction ratio of the patches 1007 and 1016 corresponding to the recording element substrate 1002 between the read images will be described with reference to FIG.

[0112] Fig. 16 is a diagram for explaining a procedure for calculating the expansion / contraction ratio of the patches 1007 and 1016 corresponding to the recording element substrate 1002 for each text chart 1202 between the read images. Fig. 16(a) is a detailed view of the patch 2003 of the read image 2001 shown in Fig. 13, and Fig. 16(b) is a detailed view of the patch 2003 of the read image 2002 shown in Fig. 13. The patch 2003 of the read image 2001 and the patch 2003 of the read image 2002 are affected by the transport speed fluctuation in different locations, so there is a difference in the expansion / contraction that occurs along the transport direction 201. The difference is calculated as follows.

[0113] The patch 2003 is a patch configured in the layout 1012 shown in FIG. 4 used to calculate the amount of misalignment between the nozzle rows 1005, and is a patch that exists in the overlapping area of ​​the scanned images 2001 and 2002. In the scanned images 2001 and 2002, a distance 4001 and a distance 4002 are obtained from the top end of the R0 pattern 1405 recorded by the nozzle row 1005 of R0, which is the reference in calculating the amount of misalignment between the nozzle rows 1005, to the top end of the R0 pattern 1411. The distances 4001 and 4002 are called SR and ER, respectively. Then, the distance SR of the scanned image 2001 is divided by the distance ER in the scanned image 2002. This makes it possible to calculate an expansion / contraction ratio 4003 of one of the text charts 1202 in the scanned image 2002 with respect to the corresponding text chart 1202 in the scanned image 2001, as shown in FIG. 16(c). This expansion / contraction ratio 4003 is called K. The calculation formula for K is shown below.

[0114]

number

[0115] In the example shown in FIG. 16, SR < ER is assumed, but the reverse magnitude relationship may also occur. Further, in order to obtain the length along the conveyance direction 201 of the patch 2003 of the read images 2001 and 2002 obtained from the sensors 202A and 202B, two other points in the patch 2003 may be used. Here, a procedure for obtaining the expansion / contraction rate corresponding to one of the text charts 1202 between the read images obtained from each sensor using the patch 2003 which is the C8 patch of the recording head 102 for the colored ink O is shown. However, patches recorded by the recording heads 102 of other ink colors may be used as long as they are included in the overlapping region of both read images 2001 and 2002 and the distance along the conveyance direction 201 can be calculated. Also, as long as the patches are included in the overlapping region of both read images 2001 and 2002 and correspond to the recording element substrate 1002 included in the same recording head 102, patches corresponding to different recording element substrates 1002 in the read images 2001 and 2002 may be used. Further, when the scanner device includes three or more sensors and three or more read images are obtained, the expansion / contraction rate is obtained for each pair of two read images by the method described above. At this time, the two read images to be used as a pair of read images are the read images obtained from two adjacent sensors in the scanner device 106.

[0116] FIG. 17 is a diagram showing the processing flow of the deviation amount calculation process 2. Each step of the deviation amount calculation process 2 will be described with reference to this FIG. 17.

[0117] In S3201, the print controller 402 determines whether there is a test chart corresponding to the recording head 102 for which the inclination amount calculation of the recording head 102 has not been performed in the first read image 2001 obtained from the sensor 202A. If there is a test chart corresponding to the recording head 102 for which the inclination amount calculation of the recording head 102 has not been performed, the process proceeds to S3202. If there is no test chart corresponding to the recording head 102 for which the inclination amount calculation of the recording head 102 has not been performed, the process proceeds to S3206. The processes from S3202 to S3205 are performed with the recording head 102 for which the inclination calculation of the recording head 102 has not been performed as the analysis target.

[0118] In S3202, the print controller 402 acquires position information of each recording element substrate 1002 in the test chart corresponding to the recording head 102 for which tilt calculation has not been performed. This position information of the recording element substrate 1002 is the information estimated in S3107 for the first read image 2001 obtained from the sensor 202A and the second read image 2002 obtained from the sensor 202B.

[0119] In S3203, the print controller 402 converts the representative positions of the patches 1007 corresponding to the recording element substrates 1002 of the first read image 2001 and the second read image 2002 into differential position information from the origin located in the overlapping area of ​​each read image. Details of S3203 will be described later with reference to FIG. 18(a).

[0120] In S3204, the print controller 402 converts the differential position information of the second scanned image 2002 based on the differential position information of the second scanned image 2002 and the expansion / contraction ratio K so that the expansion / contraction ratio becomes 1. Here, converting so that the expansion / contraction ratio becomes 1 means converting so that the distance between specific patterns in the second scanned image 2002 becomes equal to the distance between the same corresponding specific patterns in the first scanned image 2001. Details of S3204 will be described later with reference to FIG. 18(b).

[0121] In S3205, the print controller 402 calculates the inclination of a reference line for calculating the amount of misalignment between the recording element substrates 1002 for the first read image 2001, and returns to S3201. Details of S3205 will be described later with reference to FIG.

[0122] In S3206, the print controller 402 determines whether or not there is a test chart corresponding to a print head 102 for which the amount of misalignment between the printing element substrates 1002 has not been calculated. If there is a test chart corresponding to a print head 102 for which the amount of misalignment between the printing element substrates 1002 has not been calculated, the process proceeds to S3207. If there is no test chart 1202 for a print head 102 for which the amount of misalignment between the printing element substrates 1002 has not been calculated, the process ends.

[0123] In S3207, the print controller 402 selects one of the test charts corresponding to the print heads 102 for which the amount of misalignment between the printing element substrates 1002 has not been calculated.

[0124] In S3208, the print controller 402 corrects the reference line corresponding to the test chart 1202 selected in S3207 so that the inclination of the reference line becomes the same as the average of the inclinations of all the print heads 102. Details will be described later with reference to FIG.

[0125] In S3209, the print controller 402 calculates the coordinates of each recording element substrate 1002 of the second scanned image 2002 in the coordinate system of the first scanned image 2001. Details will be described later with reference to FIG.

[0126] In S3210, the amount of deviation between all of the recording element substrates 1002 in the coordinate system of the first read image is calculated using the reference line in the coordinate system of the first read image 2001 and the coordinate information of each recording element substrate 1002 obtained in each step up to this point.

[0127] 18, 19, and 20 are diagrams for explaining each step of FIG. 17. In the diagrams, the horizontal axis of the image is the X axis, and the vertical axis is the Y axis. Here, only 1206A and 1206B, which are the areas of the test chart 1206, are extracted in the first read image 2001 and the second read image 2002. Hereinafter, the test chart 1206 is used as an example for the description, but the description can also be applied to the test charts 1207 to 1213. In the diagrams, in each read image, the patch 1007 for each recording element substrate 1002 constituting the test chart 1206 is expressed as a rectangle containing the number n, indicating that it is a patch recorded by the recording element substrate Cn. In addition, the position of the patch 1007 of each recording element substrate 1002 indicates the state in which an actual deviation occurs.

[0128] FIG. 18(a) is a diagram for explaining a procedure for calculating differential position information of each recording element substrate 1002 of each read image in S3203. In calculating differential position information, a representative position of one recording element substrate 1002 existing in an overlapping area of ​​each read image is determined as an origin. Then, the distance from the origin to the representative position of each recording element substrate 1002 is obtained for the X-axis and the Y-axis. In the first read image 2001, if the coordinate point 5001 which is the representative position of the C1 patch is set as the origin, for example, the representative position of the C8 patch is set as the coordinate point 5002, so that the differential position information of the C8 patch is set as the difference 5003 on the X-axis and the difference 5004 on the Y-axis. In the second read image, if the coordinate point 5011 which is the representative position of the C8 patch is set as the origin, for example, the representative position of the C15 patch is set as the coordinate point 5012, so that the differential position information of the C15 patch is set as the difference 5013 on the X-axis and the difference 5014 on the Y-axis. In the first read image 2001, differential position information of C0 to C8 is stored, and in the second read image, differential position information of C8 to C16 is stored. Here, the origin for calculating differential position information is set to the representative position of the C0 patch in the first read image 2001, and the representative position of the C8 patch in the second read image. Since the origin when correcting the inclination of the reference line in S3208 is the representative position of the C0 patch, it is preferable to set the representative position of the C0 patch as the origin in the first read image 2001. In S3209, the representative position of the patch 1007 corresponding to each recording element substrate 1002 of the second read image 2002 is calculated in the coordinate system on the first read image 2001. At that time, the representative position of the C8 patch existing in the overlapping area is used as the boundary to use differential position information from the C8 patch, so the representative position of the C8 patch is set as the origin in the second read image 2002. In this embodiment, the origin of each read image is set to the representative position of the C0 patch and the representative position of the C8 patch, but the origin may be set anywhere as long as the same calculation can be performed. In addition, for the patch 1007 corresponding to the recording element substrate 1002 that stores the differential position information in each read image, the patch 1007 corresponding to the recording element substrate 1002 that exists only in each read image is stored in each read image. For the patch 1007 corresponding to the recording element substrate 1002 that exists in the overlapping area, only the patch 1007 that is the boundary is stored in both read images, and the others may be stored in either one of the read images.In this case, the boundary corresponds to the C8 patch in the above example.

[0129] FIG. 18B is a diagram for explaining a procedure for converting the differential position information of the second scanned image 2002 so that the expansion / contraction ratio becomes 1 based on the expansion / contraction ratio K corresponding to the differential position information of the second scanned image 2002 in S3204. The expansion / contraction ratio K corresponding to each of the text charts 1202 between the first scanned image 2001 and the second scanned image 2002 is calculated in S3109, and the value becomes the correction value of the second scanned image 2002. The distance between specific patterns in the second scanned image 2002 is converted to be equal to the distance between the corresponding same specific patterns in the first scanned image 2001. That is, the differential position information is corrected by multiplying by the expansion / contraction ratio K corresponding to the difference 5014. That is, the distance SR between the R0 patterns in the C8 patch of the first scanned image 2001 shown in FIG. 16 is corrected to be equal to the distance ER between the R0 patterns in the C8 patch of the second scanned image 2002. The difference position information of each recording element substrate 1002 of the second read image 2002 after correction can be calculated by multiplying the difference position information before correction obtained in S3203 and the corresponding expansion / contraction rate K, if there is such a value.

[0130] The differential position information, which has the representative position of the C8 patch as its origin, is corrected so that the distance between specific patterns in the second scanned image 2002 becomes equal to the distance between the same corresponding specific patterns in the first scanned image 2001. For example, in the case of the C15 patch, the representative position after correction becomes coordinate point 5022. That is, the differential position information of the C15 patch after correction is converted to difference 5023 on the X axis and difference 5024 on the Y axis.

[0131] 19(a) and 19(b) are diagrams for explaining the procedure for obtaining the reference line in S3205. Here, the procedure for obtaining the reference line in the coordinate system of the first scanned image 2001 will be explained. First, it is necessary to calculate the coordinate point of the C15 patch required for obtaining the reference line in the coordinate system of the first scanned image 2001. In S3204, the distance between specific patterns in the first scanned image 2001 and the distance between the corresponding same specific patterns in the second scanned image 2002 are set to be equal. Therefore, the coordinate point of the C15 patch can be calculated by adding the difference position information of the C8 patch in the first scanned image 2001 to the difference position information of the C15 patch in the second scanned image 2002. Specifically, the X coordinate of the C15 patch in the coordinate system of the first scanned image 2001 is the sum of the difference 5003 and the difference 5023. The Y coordinate of the C15 patch in the coordinate system of the first read image 2001 is the sum of the difference 5004 and the difference 5024. The coordinate point 5025 in FIG. 19(a) is the difference position information of the C15 patch in the coordinate system of the first read image 2001. As shown in FIG. 19(b), the line connecting the coordinate point 5001 of the C1 patch, which is the origin of the first read image 2001, and the coordinate point 5025 of the obtained C15 patch is the reference line of the corresponding recording head 102. Here, the procedure for obtaining the reference line in the coordinate system of the first read image 2001 has been described, but the reference line can be obtained in the coordinate system of the second read image 2002 in the same manner. In the coordinate system of the second read image 2002, it is necessary to obtain the coordinate point of the C0 patch in order to obtain the reference line, and this is obtained using the difference 5003 and the difference 5004. The reference line may be found in a third coordinate system other than the coordinate system of the first scanned image 2001 or the coordinate system of the second scanned image, as long as position information can be obtained in a common coordinate system.

[0132] FIG. 20A is a diagram for explaining the correction of the inclination of the reference line in S3208. In this embodiment, in the process of calculating the amount of deviation between the recording element substrates 1002, the inclination correction amount of each recording head 102 is performed. As described above, the inclination correction amount of each recording head 102 is obtained from the average of the inclinations of all the recording heads 102 and the difference of the inclination of each recording head 102. The inclination of each recording head 102 is obtained in S3205, and the average of the inclination of all the recording heads 102 is also obtained from the average of the inclinations of all the recording heads 102. The coordinate point 5027 shown in FIG. 20 is a coordinate point obtained by rotating the coordinate point 5025 by an angle 5026, which is the amount of inclination correction of the corresponding recording head 102, with the coordinate point 5001 as the origin. Therefore, the line connecting the coordinate point 5001 and the coordinate point 5027 becomes the final reference line used to calculate the amount of deviation between the recording element substrates 1002.

[0133] FIG. 20B is a diagram for explaining the procedure of calculating the coordinates of each recording element substrate 1002 of the second read image 2002 on the first read image 2001 in S3209. In order to calculate the amount of deviation between the recording element substrates 1002 with respect to the obtained reference line, it is necessary to calculate the coordinate points of all the recording element substrates 1002 of the second read image 2002 in the coordinate system of the first read image 2001. For this purpose, the differential position information of each recording element substrate 1002 of the second read image 2002 recalculated in S3203 is used. This procedure is the same as the procedure of calculating the coordinate points of C15 in the coordinate system of the first read image 2001 in S3205. Using the reference line obtained in this way and the coordinate points that are the differential position information of each recording element substrate 1002, it is possible to calculate the amount of deviation between all the recording element substrates 1002 in S3210.

[0134] As described above, according to the inkjet recording device of the present invention, even if the test chart is divided into multiple read images by being read by a scanner device having multiple sensors, the amount of misalignment of the recording head can be calculated with high accuracy.

[0135] In this embodiment, the scanner device has two sensors, but the present invention can also be applied to three or more sensors if there is an overlapping area including a test chart in the read images obtained by adjacent sensors.

[0136] In addition, in this embodiment, the necessary processing was performed to calculate the amount of misalignment between the recording element substrates, but this can also be applied to the calculation of other correction amounts if a reference line for determining the correction amount exists across multiple read images. Furthermore, although an inkjet recording device has been described as an example of a recording device up to this point, the method of applying the recording material is not limited to the inkjet method of ejecting ink, and the technology disclosed herein can also be applied to recording devices that use other methods of applying recording material.

[0137] <Other embodiments> In the above embodiment, the inkjet recording apparatus 100 has multiple recording heads 102, but it may have only one recording head 102. The recording head 102 does not have to be a full line head, and may be a serial type in which a carriage on which the recording head 102 is detachably mounted is moved in the Y direction while ejecting ink from the recording head 102 to form an ink image. The recording medium P may be a sheet of paper, in which case the apparatus has a transport mechanism suitable for the sheet of paper.

[0138] (Other Examples) The present invention can also be realized by a process in which a program for implementing one or more of the functions of the above-described embodiments is supplied to a system or device via a network or a storage medium, and one or more processors in a computer of the system or device read and execute the program. The present invention can also be realized by a circuit (e.g., ASIC) that implements one or more of the functions.

[0139] The present disclosure includes the following configurations and methods. [Configuration 1] An inkjet recording apparatus having one or more recording means including a plurality of recording element substrates for applying a recording material, a read control means for dividing a test chart including a plurality of patches corresponding to each of the recording element substrates printed on a recording medium by the recording means, using a plurality of optical sensors, and causing a reading device to read the divided test chart; a calculation means for calculating an expansion / contraction ratio of a patch corresponding to a recording element substrate included in the same recording means for a pair of read images consisting of two read images out of a plurality of read images obtained by reading a test chart printed on the recording medium by the reading device; an adjustment unit that adjusts a deposition position of the recording material applied from the recording unit based on the expansion / contraction ratio calculated by the calculation unit and position information of the patch in the plurality of read images; A recording device comprising: [Configuration 2] the patches corresponding to the recording element substrates included in the same recording means are included in overlapping areas in the read image pair obtained by overlappingly reading the same portion of the test chart; 2. The recording device according to configuration 1. [Configuration 3] the patches corresponding to the recording element substrates included in the same recording means are patches corresponding to the same recording element substrate included in the same recording means; 3. The recording device according to configuration 2. [Configuration 4] the adjustment means converts position information of the patch in one of the pair of read images so that the expansion / contraction ratio becomes 1, and combines the position information of the patch in the pair of read images based on the position information of the patch in the overlapping region. 4. The recording device according to configuration 2 or 3. [Configuration 5] the adjustment unit calculates a deviation amount of the deposition position of the recording material based on the position information of the combined patch, and adjusts the deposition position of the recording material applied from the recording unit based on the deviation amount. 5. The recording device according to configuration 4. [Configuration 6] the deviation amount includes a deviation amount calculated based on a reference line connecting the positions of the patches corresponding to two predetermined recording element substrates in the position information of the combined patches; 6. The recording device according to configuration 5. [Configuration 7] the reference line is a line connecting the positions of patches corresponding to two different recording element substrates included in the same recording means; 7. The recording device according to configuration 6. [Configuration 8] The positions of the two patches constituting the reference line are expressed by coordinate points in a common coordinate system. 8. The recording device according to configuration 6 or 7. [Configuration 9] The positions of the two patches constituting the reference line are expressed as a difference indicating a distance from a position of a predetermined patch in the overlap region. 9. The recording device according to any one of configurations 6 to 8. [Configuration 10] When the recording means includes a plurality of recording means, the adjustment means corrects the reference line so that the inclination of the reference line becomes the same as the average inclination of the plurality of recording means. 10. The recording device according to any one of configurations 6 to 9. [Configuration 11] the recording element substrate is a recording element substrate on which nozzles for ejecting ink are arranged; 11. The recording device according to any one of configurations 1 to 10. [Configuration 12] The pair of scanned images is composed of two scanned images obtained by two adjacent optical sensors in the scanning device. 12. The recording device according to any one of configurations 1 to 11. [Configuration 13] A recording method having one or more recording means including a plurality of recording element substrates for applying a recording material, a step of dividing a test chart including a plurality of patches corresponding to each of the recording element substrates printed on a recording medium by the recording means, using a plurality of optical sensors, and reading the divided test chart with a reading device; calculating a stretching ratio of a patch corresponding to a recording element substrate included in the same recording means for a pair of read images consisting of two read images out of the plurality of read images obtained by reading the test chart printed on the recording medium by the reading device; adjusting a deposition position of the recording material applied from the recording means based on the expansion / contraction ratio calculated in the calculating step and position information of the patches in the plurality of read images; A recording method comprising: [Configuration 14] 14. A program for causing a computer to execute each step of the recording method according to claim 13.

Claims

1. A recording apparatus having one or more recording means including a plurality of recording element substrates for applying a recording material, a read control means for dividing a test chart including a plurality of patches corresponding to each of the recording element substrates printed on a recording medium by the recording means, using a plurality of optical sensors, and causing a reading device to read the divided test chart; a calculation means for calculating an expansion / contraction ratio of a patch corresponding to a recording element substrate included in the same recording means for a pair of read images consisting of two read images out of a plurality of read images obtained by reading a test chart printed on the recording medium by the reading device; an adjustment unit that adjusts a deposition position of the recording material applied from the recording unit based on the expansion / contraction ratio calculated by the calculation unit and position information of the patch in the plurality of read images; A recording device comprising:

2. the patches corresponding to the recording element substrates included in the same recording means are included in overlapping areas in the read image pair obtained by overlappingly reading the same portion of the test chart; 2. The recording apparatus according to claim 1,

3. the patches corresponding to the recording element substrates included in the same recording means are patches corresponding to the same recording element substrate included in the same recording means; 3. The recording apparatus according to claim 2.

4. the adjustment means converts position information of the patch in one of the pair of read images so that the expansion / contraction ratio becomes 1, and combines the position information of the patch in the pair of read images based on position information of the patch in the overlapping region.

3. The recording apparatus according to claim 2.

5. the adjustment unit calculates a deviation amount of the deposition position of the recording material based on the position information of the combined patch, and adjusts the deposition position of the recording material applied from the recording unit based on the deviation amount.

5. The recording apparatus according to claim 4.

6. the deviation amount includes a deviation amount calculated based on a reference line connecting positions of patches corresponding to two predetermined recording element substrates in the position information of the combined patches; 6. The recording apparatus according to claim 5.

7. the reference line is a line connecting the positions of patches corresponding to two different recording element substrates included in the same recording means; 7. The recording apparatus according to claim 6.

8. The positions of the two patches constituting the reference line are expressed by coordinate points in a common coordinate system.

7. The recording apparatus according to claim 6.

9. The positions of the two patches constituting the reference line are expressed as a difference indicating a distance from a position of a predetermined patch in the overlap region.

7. The recording apparatus according to claim 6.

10. When the recording means includes a plurality of recording means, the adjustment means corrects the reference line so that the inclination of the reference line becomes the same as the average inclination of the plurality of recording means.

7. The recording apparatus according to claim 6.

11. the recording element substrate is a recording element substrate on which nozzles for ejecting ink are arranged; 2. The recording apparatus according to claim 1,

12. The pair of scanned images is composed of two scanned images obtained by two adjacent optical sensors in the scanning device.

12. The recording apparatus according to claim 1,

13. A recording method having one or more recording means including a plurality of recording element substrates for applying a recording material, a step of dividing a test chart including a plurality of patches corresponding to each of the recording element substrates printed on a recording medium by the recording means, using a plurality of optical sensors, and reading the divided test chart with a reading device; calculating a stretching ratio of a patch corresponding to a recording element substrate included in the same recording means for a pair of read images consisting of two read images out of the plurality of read images obtained by reading the test chart printed on the recording medium by the reading device; adjusting a deposition position of the recording material applied from the recording means based on the expansion / contraction ratio calculated in the calculating step and position information of the patch in the plurality of read images; A recording method comprising:

14. A program for causing a computer to execute each step of the recording method according to claim 13.

Images