Printing apparatus, control method of printing apparatus, and measurement pattern

Abstract

To provide a technique for performing scanning and colorimetry of a pattern by one time conveyance of a printing medium without rewinding.SOLUTION: The recording device includes a transport control unit that performs transport control of the print medium, a printing unit that prints a first pattern and a second pattern including overlapping gradation ranges on the print medium in one transport, a first measurement unit that measures the first pattern of the print medium transported in first transport control, and a second measurement unit that measures the second pattern of the print medium transported in second transport control. After printing the first pattern, the printing unit prints the second pattern such that a distance between the second measurement unit and the second pattern at a start time point of switching from the first transport control to the second transport control is equal to or larger than a transport distance by which the printing medium is transported during switching from the first transport control to the second transport control.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to recording technology. [Background technology]

[0002] A conventional method for calibrating a scanner using a scanner and a colorimeter is to print a correction pattern at the overlapping portion of the line scanner, measure the correction pattern using the line scanner and the colorimeter, and then calibrate the overlapping portion of the line scanner based on the measurement results. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Application No. 2019-233960 Summary of the Invention [Problem to be solved by the invention]

[0004] When a printed pattern is long enough to span both the scanner and the colorimeter in the paper transport direction, the paper transport control used when reading by the scanner and the colorimeter differs, which poses a problem: it is not possible to read both with one-way transport control, and a rewinding operation is required.This invention provides technology for scanning and measuring the pattern by transporting the print medium once without rewinding it. [Means for solving the problem]

[0005] One aspect of the present invention comprises a transport control means for controlling the transport of a printing medium, a printing means for printing a first pattern and a second pattern including overlapping gradation ranges on the printing medium in a single transport, a first measurement means for measuring the first pattern on the printing medium transported under a first transport control by the transport control means, and a second measurement means for measuring the second pattern on the printing medium transported under a second transport control by the transport control means, wherein after printing the first pattern, the printing means prints the second pattern so that the distance between the second measurement means and the second pattern at the start of switching from the first transport control to the second transport control is greater than or equal to the transport distance over which the printing medium is transported during switching from the first transport control to the second transport control. [Effects of the Invention]

[0006] According to the present invention, it is possible to provide a technique for scanning a pattern and measuring the color of the print medium in one transport without rewinding. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 shows an example of the configuration of a recording device 100. [Figure 2] FIG. 2 is a diagram showing an example of the schematic configuration of a recording head 101. [Figure 3] FIG. 1 is a block diagram showing an example of a system configuration. [Figure 4] 4 is a flowchart of image processing for printing in the recording device 100. [Figure 5] 5A and 5B are diagrams illustrating scanner correction patterns printed on a printing medium. [Figure 6] 10A is a diagram showing the area from the start position of the scanning pattern 502 to the first gradation pattern, and FIG. 10B is a diagram showing the area from the start position of the color measurement pattern 503 to the first gradation pattern. [Figure 7] 5 is a diagram showing the positional relationship between the scanner unit 108, the colorimetric unit 109, the scanning pattern 502, and the colorimetric pattern 503. FIG. [Figure 8]6 is a flowchart of a process performed by the recording apparatus 100 to measure the scanner correction pattern. [Figure 9] 3A and 3B are diagrams for explaining transport control performed in parallel with the scanning operation of the scanner unit 108. [Figure 10] 3A and 3B are diagrams for explaining transport control performed in parallel with the color measurement operation by the color measurement unit 109. [Figure 11] 1 is a diagram showing the positional relationship between a scanner unit 108, a colorimetric unit 109, and a scanner correction pattern 1101. FIG. [Figure 12] 10 is a flowchart of a process for generating a scanner correction table by the recording device 100. [Figure 13] FIG. 6 is a diagram showing the center positions of a scanning gradation pattern 601 and a colorimetry gradation pattern 604. [Figure 14] FIG. 10 is a diagram for explaining derivation of a correction amount in step S1207. [Figure 15] FIG. 10 is a diagram showing an example of the configuration of a correction table. [Figure 16] 10 is a graph showing the variation of scan values ​​with respect to pixel position X. [Figure 17A] 5 is a diagram showing the positional relationship between the scanner unit 108, the colorimetric unit 109, the scanning pattern 502, and the colorimetric pattern 503. FIG. [Figure 17B] 5 is a diagram showing the positional relationship between the scanner unit 108, the colorimetric unit 109, the scanning pattern 502, and the colorimetric pattern 503. FIG. [Figure 17C] 5 is a diagram showing the positional relationship between the scanner unit 108, the colorimetric unit 109, the scanning pattern 502, and the colorimetric pattern 503. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0008] Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. Note that the following embodiments do not limit the invention according to the claims. Although multiple features are described in the embodiments, not all of these multiple features are necessarily essential to the invention, and multiple features may be combined arbitrarily. Furthermore, in the accompanying drawings, the same reference numerals are used to designate the same or similar components, and redundant explanations will be omitted.

[0009] [First embodiment] First, an example of the configuration of a recording apparatus 100 according to this embodiment will be described with reference to Fig. 1. As shown in Fig. 1, the recording apparatus 100 is an inkjet recording apparatus. The recording apparatus 100 is a full-line type recording apparatus, and has a recording head 101 whose width is equal to or greater than the width of a print medium such as paper.

[0010] The print head 101 has a print element array 102 in which multiple print elements that eject cyan (C) ink are arranged in a direction (along the X axis) perpendicular to the print medium transport direction (along the Y axis), a print element array 103 in which multiple print elements that eject magenta (M) ink are arranged in the X axis, a print element array 104 in which multiple print elements that eject yellow (Y) ink are arranged in the X axis, and a print element array 105 in which multiple print elements that eject black (K) ink are arranged in the X axis. The print element arrays 102 to 105 are arranged in the Y axis.

[0011] With this configuration, the recording head 101 can eject color inks of cyan (C), magenta (M), yellow (Y), and black (K) sequentially onto a printing medium.

[0012] The types of ink used in the printing apparatus 100 are not limited to C, M, Y, and K, but other types of ink may also be used. Furthermore, the arrangement order of the printing element arrays in the print head 101 is not limited to the arrangement order shown in FIG. 1, but other arrangement orders may also be used.

[0013] The print medium is a print medium such as roll paper that can be printed on one sheet continuously, and is transported in the transport direction with the rotation of transport roller 106. Recording head 101 performs a recording process to print (form) images and characters on the transported print medium by ejecting ink onto the print medium. The print medium at the position where the recording process by recording head 101 is performed is supported from below by platen 107, which is a flat plate, and the distance from recording head 101 and smoothness are maintained.

[0014] An example of the schematic configuration of the print head 101 will be described with reference to Figure 2. In the print element arrays 102 to 105 of the print head 101, print element substrates 202, on which print elements 201 are arranged at a constant pitch along the X axis, are arranged so that they are continuous along the X axis and alternate in the direction along the Y axis, with overlapping regions D provided. Each print element 201 ejects ink at a constant frequency in accordance with print data onto a print medium transported at a constant speed in the transport direction, thereby recording an image on the print medium with a resolution corresponding to the arrangement pitch of the print elements 201.

[0015] Returning to Figure 1, downstream of the recording head 101 in the transport direction of the printing medium, a scanner unit 108 for measuring (scanning) the scanning pattern printed on the printing medium by the recording head 101 is provided on the transport path of the printing medium.

[0016] Additionally, downstream of the scanner unit 108 in the transport direction of the print medium, a colorimetric unit 109 is provided on the transport path of the print medium to measure (measure the color of) the colorimetric pattern printed on the print medium by the recording head 101. The colorimetric unit 109 has a colorimeter 110 that measures the colorimetric pattern while moving along the X axis.

[0017] Next, an example of the configuration of a system including the above-mentioned recording device 100 will be described using the block diagram of Fig. 3. As shown in Fig. 3, the system according to this embodiment includes the above-mentioned recording device 100 and a host PC 300.

[0018] First, we will explain the host PC 300. The host PC 300 is a computer device such as a PC, a tablet terminal device, or a smartphone, and for example, a user can operate the host PC 300 to submit (send) a print job to the recording device 100.

[0019] The CPU 301 executes various processes using computer programs and data stored in the RAM 302. As a result, the CPU 301 controls the overall operation of the host PC 300 and executes or controls various processes that will be described as processes performed by the host PC 300.

[0020] The RAM 302 is an example of volatile memory. The RAM 302 has an area for storing computer programs and data loaded from the HDD (hard disk drive) 303, and an area for storing data received from the recording device 100 via the communication I / F 304. The RAM 302 also has a work area used by the CPU 301 when executing various processes. In this way, the RAM 302 can provide various areas as needed.

[0021] The HDD 303 is an example of a non-volatile memory, and stores an OS, computer programs and data for causing the CPU 301 to execute or control various processes described as processes performed by the host PC 300.

[0022] The communication I / F 304 functions as an interface for performing data communication with the recording device 100 via a network such as a LAN or the Internet. The connection method for transmitting and receiving data via the communication I / F 304 can be a wired connection such as USB, IEEE1394, or LAN (Local Area Network), or a wireless connection such as Bluetooth (registered trademark) or WiFi (registered trademark).

[0023] The input device I / F 305 is an interface for connecting a user interface (HID: Human Interface Device), which is an input device such as a keyboard, a mouse, a touch panel, etc. A user can input various instructions and information to the host PC 300 by operating such a user interface.

[0024] The display device I / F 306 is an interface for connecting a display device having a liquid crystal screen or a touch panel screen. The display device displays the processing results of the CPU 301 as images, text, etc. The display device may also be a projection device such as a projector that projects images and text.

[0025] The CPU 301, RAM 302, HDD 303, communication I / F 304, input device 305, and display device 306 are all connected to a system bus 307. Note that the configuration of the host PC 300 shown in Figure 1 is merely an example and can be modified or changed as appropriate.

[0026] Next, we will explain the recording device 100. The recording device 100 performs processing in response to various instructions from the host PC 300, and for example, prints images and text on a print medium based on a print job submitted (sent) from the host PC 300.

[0027] The CPU 311 executes various processes using computer programs and data stored in the RAM 312. As a result, the CPU 311 controls the overall operation of the recording device 100, and also executes or controls various processes that will be described as processes performed by the recording device 100.

[0028] The RAM 312 is an example of volatile memory. The RAM 312 has an area for storing computer programs and data loaded from the ROM 313, and an area for storing data received from the host PC 300 via the communication I / F 314. The RAM 312 also has a work area used by the CPU 311 and the image processing accelerator 316 when executing various processes. In this way, the RAM 312 can provide various areas as needed.

[0029] The ROM 313 stores setting data for the recording device 100, computer programs and data related to the startup of the recording device 100, and computer programs and data related to the operation of the recording device 100. The ROM 313 also stores computer programs and data for causing the CPU 311 to execute or control various processes described as processes performed by the recording device 100.

[0030] The communication I / F 314 functions as an interface for performing data communication with the host PC 300 via a network such as a LAN or the Internet. As a connection method for transmitting and receiving data in the communication I / F 314, a wired connection such as USB, IEEE1394, or LAN (Local Area Network) or a wireless connection such as Bluetooth (registered trademark) or WiFi (registered trademark) can be used.

[0031] The head controller 315 controls the operation of the print head 101, for example, by controlling the heating operation of the print head 101 based on print data. For example, when the CPU 311 writes control parameters and print data to a predetermined address in the RAM 312, the head controller 315 reads the control parameters and print data from the predetermined address and controls the operation of the print head 101 using the read control parameters and print data, thereby discharging ink onto the print medium.

[0032] The image processing accelerator 316 is configured with hardware and executes image processing faster than the CPU 311. For example, when the CPU 311 writes parameters and data required for image processing to a predetermined address in the RAM 312, the image processing accelerator 316 reads the parameters and data from the predetermined address and performs image processing using the read parameters and data. Note that the image processing accelerator 316 is not necessarily a required element, and the image processing may be executed by the CPU 311 depending on the specifications of the recording device 100, etc.

[0033] The scanner device 317 has the above-mentioned scanner unit 108, and optically reads the conveyed print medium using the scanner unit 108, and generates a read image (scanned image) as scan data based on the read information.

[0034] The color measurement device 318 has the above-mentioned color measurement unit 109 (including the colorimeter 110), and uses the colorimeter 110 to obtain the spectral reflectance of the conveyed print medium.

[0035] The CPU 311, RAM 312, ROM 313, communication I / F 314, head controller 315, image processing accelerator 316, scanner device 317, and colorimeter device 318 are all connected to a system bus 319. Note that the configuration of the recording device 100 shown in Figure 1 is merely an example and can be modified or changed as appropriate.

[0036] Furthermore, in this embodiment, a system in which the host PC 300 and the recording device 100 are separate devices will be described, but the present invention is not limited to this, and the host PC 300 and the recording device 100 may be integrated into a system.

[0037] Next, image processing for printing in the recording device 100 will be described with reference to the flowchart in Fig. 4. Below, a case will be described in which the processing according to the flowchart in Fig. 4 is executed by the CPU 311, but part or all of the processing according to the flowchart in Fig. 4 may also be executed by the image processing accelerator 316. Also, the processing according to the flowchart in Fig. 4 may also be executed by the CPU 301 of the host PC 300.

[0038] In step S401, the CPU 311 converts the input image into an image that corresponds to the color reproduction gamut of the recording device 100. In this embodiment, the input image is data that indicates color coordinates (R, G, B) in a color space coordinate system such as sRGB, which is the representation color of the monitor. The input image may be an image based on a print job, or may be an image read from the host PC 300 or ROM 313.

[0039] For example, the CPU 311 converts an input image that is an 8-bit RGB image (an image in which each pixel has an 8-bit pixel value for each of R (red), G (green), and B (blue)) into an R'G'B' image in the color reproduction gamut of the recording device 100 using a known method such as matrix calculation processing or processing using a 3D LUT (3D lookup table). In this embodiment, a 3D LUT is used in combination with an interpolation calculation to convert the image. Note that the input image is not limited to an RGB image, and may be, for example, an image in which each pixel has a pixel value for each of C, M, Y, and K. In this case, a 4D LUT is used instead of a 3D LUT to convert the image.

[0040] In step S402, the CPU 311 converts the R'G'B' image into an image based on color signals for the color inks used in the printing apparatus 100. In this embodiment, cyan (C), magenta (M), yellow (Y), and black (K) inks are used as color inks, and therefore the R'G'B' image is converted into a CMYK image in which each pixel has a pixel value (8 bits) for C, M, Y, and K, respectively. This color conversion, like the image conversion in step S401 above, is performed using a 3D LUT in combination with interpolation. Note that, as with the above, other conversion methods, such as matrix calculation processing, can also be used. Furthermore, although the number of inks used is four, C, M, Y, and K, other inks may be added.

[0041] In step S403, the CPU 311 converts the CMYK image data into ink amount signal values ​​corrected to correspond to the number of recording dots. Any method can be used to convert into ink amount signal values, such as a method of performing gamma adjustment using a one-dimensional lookup table.

[0042] In step S404, the CPU 311 performs a quantization process on the ink volume signal values ​​of C, M, Y, and K for each ink obtained by the conversion in step S403. There are various quantization levels for quantization, such as binarization, ternary conversion, or 16-value conversion. Generally, during binarization, the ink volume signal values ​​of cyan (C), magenta (M), yellow (Y), and black (K) are converted into print data that is 1-bit data for each of C, M, Y, and K indicating whether or not an ink dot is present. As a quantization process method, known pseudo-halftone processes such as a dither matrix method or error diffusion method may be used.

[0043] The CPU 311 then stores the print data obtained by this processing in the RAM 312. The head controller 315 controls the ejection of ink by the print head 101 based on the print data stored in the RAM 312, thereby printing images and characters on the transported print medium. The print data is kept stored in the RAM 312 for a certain period of time after printing.

[0044] Next, the scanner unit 108 and colorimetric unit 109 will be described.

[0045] The scanner unit 108 is installed as a line scanner having a line sensor that covers the entire width of the print medium (the length in the direction along the X axis). The colorimetric unit 109 has a colorimeter 110 that includes a sensor for color measurement.

[0046] The scanner unit 108 optically reads a print medium, generates a read image (scanned image) based on the read information, and stores the generated scanned image in, for example, the HDD 303.

[0047] Here, the scanned image is two-dimensional image information in which each pixel has an RGB value or a brightness value, and its resolution is, for example, 600 dpi in both the X-axis direction and the Y-axis direction. Note that the resolution may be different in the X-axis direction and the Y-axis direction. During scanning, the scanner unit 108 continuously scans while transporting the print medium, thereby obtaining a scanned image that is a continuous two-dimensional image. The scanner unit 108 may have multiple scanners, and the scanners may be arranged consecutively or staggered in the X-axis direction so that the entire width of the print medium is covered.

[0048] The colorimeter 110 stores the spectral reflectances acquired as described above, for example, in the HDD 303. The CPU 311 may also store color values ​​in a device-independent color space calculated from the spectral reflectances in the HDD 303. Specifically, the CPU 311 may store the spectral reflectances in 10-nm increments up to the visible light range of 380 to 780 nm, or the results of converting the spectral reflectances into data in a color space such as CIEXYZ, CIELab, sRGB, or AdobeRGB in the HDD 303. The spectral reflectances, which are the colorimetric results, are obtained as the reflectance averaged within the aperture shape of the colorimeter 110, for example, a circle with a diameter φ of 3.5 mm.

[0049] During color measurement, the colorimeter 110 is moved in the direction along the X axis while measurements are taken at regular intervals, allowing measurements of multiple locations on one line to be taken. The entire area of ​​the print medium is measured by alternately repeating measurements of one line as the print medium is transported and the colorimeter 110 is moved in the direction along the X axis.

[0050] As will be described later, the transport control of the print medium when scanned by the scanner unit 108 and the transport control of the print medium when measured by the colorimeter 110 are not the same, and different transport controls are required when scanning by the scanner unit 108 and when measuring the colorimeter 110. In order to perform scanning and color measurement in a single transport without rewinding, the recording device 100 switches the transport control of the print medium to transport control for scanning before the scanning pattern reaches the scanner unit 108, and switches the transport control of the print medium to transport control for color measurement before the colorimeter pattern reaches the colorimeter unit 109 (colorimeter 110). This allows the recording device 100 to perform scanning and color measurement continuously.

[0051] Next, the scanner correction pattern printed on the printing medium will be described with reference to Fig. 5. As shown in Fig. 5, the scanner correction pattern is a pattern used to calibrate the scanner unit 108, and has two patterns: a scanning pattern 502 and a colorimetry pattern 503. The scanning pattern 502 is printed first on the conveyed printing medium, and then the colorimetry pattern 503 is printed after a gap, which will be described later. As a result, a margin area 504 is formed on the printing medium between the scanning pattern 502 and the colorimetry pattern 503.

[0052] Both the scanning pattern 502 and the color measurement pattern 503 have gradation patterns corresponding to the ink colors cyan (C), magenta (M), yellow (Y), and black (K).

[0053] 6(a) is a diagram showing the area from the leading position (the downstream end position in the transport direction) of the scanning pattern 502 to the first gradation pattern. FIG. 6(b) is a diagram showing the area from the leading position (the downstream end position in the transport direction) of the color measurement pattern 503 to the first gradation pattern.

[0054] Both the scanning pattern 502 and the colorimetry pattern 503 have a configuration in which multiple gradation patterns, each with a uniform gradation value in the direction along the X axis, are arranged in the direction along the Y axis, separated by gradation. The gradation pattern 601 in the scanning pattern 502 and the gradation pattern 604 in the colorimetry pattern 503 do not necessarily have to be the same, but it is desirable that the range of gradation values ​​in one gradation pattern has a gradation range that overlaps with the range of gradation values ​​in the other gradation pattern. In the following explanation, the gradation patterns will be described assuming that they are common to each ink color, but there is no problem if the gradation patterns are different for each ink color.

[0055] In addition to the gradation patterns, the scanning pattern 502 and the color measurement pattern 503 can include specific patterns required for analyzing the data obtained during measurement or the data obtained by the measurement. As an example, as shown in Fig. 6(a), the scanning pattern 502 includes position specifying patterns 602 and 603 for specifying the position of the gradation pattern for each color and the position of each ejection nozzle. The position specifying patterns 602 and 603 have multiple rectangles arranged at predetermined intervals along the X-axis, and the rectangle at the center is replaced with a cross mark to determine the center of the image.

[0056] The color measurement pattern 503 can also include a positioning pattern 605 that determines the color measurement start position, and a trigger pattern 606 that indicates the end of the gradation pattern in the direction along the X axis.

[0057] Next, the margin area 504 in Fig. 5 will be described. Fig. 7 shows the positional relationship between the scanner unit 108, the colorimetry unit 109, the scanning pattern 502, and the colorimetry pattern 503 at the time when the scanner unit 108 has completed scanning the scanning pattern 502 when measurements are performed on the scanner correction pattern in the order of scanning and colorimetry. That is, in the state of Fig. 7, the scanner unit 108 has finished scanning the rear end of the scanning pattern 502 (one end of the scanning pattern 502 on the upstream side in the transport direction).

[0058] Because the transport control for scanning and the transport control for colorimetry are different, if the colorimetry pattern 503 is to be measured immediately after scanning the scan pattern 502, a switch from the transport control for scanning to the transport control for colorimetry is required. When the transport control is switched, the switch in the transport speed temporarily causes variations in the in-plane tension of the print medium, resulting in an unstable transport height and speed of the print medium. Fluctuations in the transport height and speed of the print medium result in inaccurate scan and colorimetry results, so it is desirable to measure the transport height and speed after a certain amount of time has passed since the start of the transport speed switch and when they have stabilized. In the following explanation, it is assumed that the transport distance required to switch the transport control (the distance the print medium is transported during the transport control switch) includes the distance required for stabilization.

[0059] When measuring the colorimetry pattern 503 immediately after completing the scanning of the scan pattern 502, the distance 702 obtained by adding the distance 701 between the colorimetry unit 109 (colorimeter 110) and the scanner unit 108 and the length of the margin area 504 in the conveying direction (Y-axis direction) must be greater than or equal to the conveying distance required to switch the conveying control.

[0060] In other words, the recording apparatus 100 simply prints the colorimetry pattern 503 on the print medium so that the sum of the distance 701 between the colorimetry unit 109 (colorimeter 110) and the scanner unit 108 and the length of the marginal area 504 in the transport direction (Y-axis direction) is equal to or greater than the transport distance required to switch transport control. For example, the length of the marginal area 504 in the Y-axis direction must satisfy the following formula (1):

[0061] (length of margin area 504 in the Y-axis direction)= (Transport distance required for switching transport control) - (distance 701 between the colorimetric unit 109 (colorimeter 110) and the scanner unit 108) ... (1) Therefore, after printing the scanning pattern 502, the recording device 100 sets the margin area 504 so that the length of the margin area 504 in the Y-axis direction satisfies equation (1) (or so that the left side of equation (1) is greater than the right side), and then prints the colorimetry pattern 503.

[0062] Here, if the length of the margin area 504 in the Y-axis direction is a negative value according to equation (1), the length of the margin area 504 in the Y-axis direction can be set to 0. In that case, the scanning pattern 502 and the colorimetry pattern 503 should be connected without any gaps, or there should be a greater length between them.

[0063] In other words, after printing the scanning pattern 502, the recording device 100 prints the colorimetry pattern 503 so that the distance between the colorimetry unit 109 (colorimetry machine 110) and the colorimetry pattern 503 at the start of switching from scanning transport control to colorimetry transport control is greater than the transport distance over which the printing medium is transported during switching from scanning transport control to colorimetry transport control.

[0064] The transport distance required to switch transport control varies depending on the transport speed and the amount of fluctuation in the transport height and speed of the print medium at the time of switching. Generally, however, the faster the transport speed and the greater the amount of fluctuation in the transport height and speed of the print medium, the longer the distance required. The transport distance required for switching can be obtained by acquiring a value set for each transport setting or paper setting, or it can be acquired in advance as a length that allows switching regardless of the setting. For example, if the transport distance required to switch transport control is 1400 mm and the distance between the scanner unit 108 and the colorimeter 110 is 400 mm, the length of the required margin area 504 in the Y-axis direction is 1400 mm - 400 mm = 1000 mm (or 1000 mm or more).

[0065] The printing order of the scanning pattern 502 and the color measurement pattern 503 is not limited to the above printing order, but may be the reverse of the above printing order, as will be described in the following embodiments.

[0066] In addition, the scanning pattern 502 and the colorimetry pattern 503 may be common, in which case the specific patterns required for measurement by the scanner unit 108 and the colorimetry device 110 will be included in both the scanning and colorimetry patterns.

[0067] Next, the process performed by the recording apparatus 100 to measure the scanner correction pattern will be described with reference to the flowchart of FIG.

[0068] In step S801, the head controller 315 controls the recording head 101 to print a scanner correction pattern on the printing medium. In printing the scanner correction pattern, as described above, the recording device 100 prints the scanning pattern 502, then provides a marginal area 504 so that the length of the marginal area 504 in the Y-axis direction satisfies equation (1) (or so that the left side of equation (1) is greater than the right side), and then prints the colorimetry pattern 503.

[0069] The scanner correction pattern is converted into quantized data by image processing, and then transferred to the head controller 315, where it is printed onto the printing medium. The transport speed of the printing medium during the printing process is determined based on settings stored in advance for each printing medium or values ​​set by the user. After the printing medium is accelerated from a stationary state to the set transport speed and the speed stabilizes, ink is ejected from the recording elements 201, thereby printing onto the printing medium.

[0070] In step S802, the CPU 311 switches the transport control from the transport speed during printing of the scanner correction pattern to the transport speed at the start of scanning of the scan pattern 502 by the scanner unit 108. For example, if the transport speed during printing of the scanner correction pattern is faster than the transport speed during scanning, the CPU 311 controls the transport speed to decrease after printing of the scanner correction pattern is completed, thereby achieving a transport speed suitable for scanning.

[0071] In step S803, under the control of CPU 311, scanner unit 108 scans scan pattern 502. The start position of the scan may be determined by providing a start position determination pattern at the beginning of scan pattern 502 and identifying the pattern using a sensor in scanner unit 108, or the start position may be determined by obtaining the number of rotations of a motor used to transport the print medium using an encoder and estimating the transport distance of the print medium.

[0072] The transport control that is performed in parallel with the scanning operation of the scanner unit 108 will be explained using Fig. 9. In the scanning process, the print medium is continuously transported at a constant speed while the scanner unit 108 continuously scans in parallel, thereby obtaining a two-dimensional image whose image height is the transport distance during scanning.

[0073] 9(a) shows the transport control of the print medium at the start of scanning the scan pattern 502. The scanner unit 108 is a line scanner that covers the entire width of the print medium, so the scan pattern 502 can be scanned by transporting the print medium without moving the scanner unit 108 itself during scanning.

[0074] 9(b) shows the transport control of the print medium while scanning the scan pattern 502. The entire scan pattern 502 is scanned by performing a scan operation by the scanner unit 108 while continuing to transport the print medium at a constant speed. After scanning of the scan pattern 502 for all colors to be scanned is completed, the scan operation ends. Note that the image height varies depending on the transport distance during scanning as well as the pixel value acquisition cycle of the scanner unit 108, and the aspect ratio of the acquired image does not necessarily have to match the actual aspect ratio of the printed pattern.

[0075] In step S804, the CPU 311 switches the transport control from the transport speed during scanning by the scanner unit 108 to the transport speed at which the colorimetry unit 109 starts measuring the colorimetry pattern 503. In this embodiment, the transport control is switched before the leading position of the colorimetry pattern 503 reaches the colorimeter 110, and switching to transport control for colorimetry and colorimetry operation are performed without rewinding and transporting the print medium. In the colorimetry operation, the leading position of the colorimetry pattern 503 is determined before the start of colorimetry, so the print medium is transported to a position for determining the colorimetry start position during the process of switching to transport control for colorimetry.

[0076] In step S805, under the control of the CPU 311, the colorimetry unit 109 performs colorimetry of the colorimetry pattern 503. In this embodiment, the colorimetry unit 109 determines the colorimetry start position before starting colorimetry. To determine the colorimetry start position, the print medium is first transported to a position approximately near the colorimetry pattern 503 based on the rotation speed of the transport motor, and then transport control for colorimetry is switched to begin determining the start position. In this embodiment, the positioning pattern 605 is used to determine the colorimetry start position. A location where luminance values ​​fluctuate is searched for while repeating transport control for a fixed distance and colorimetry in the X-axis direction. If a luminance fluctuation estimated to be the positioning pattern is acquired, the colorimetry operation is initiated. In the colorimetry operation, the print medium is transported to the first gradation of the gradation pattern based on a relative distance stored in advance with respect to the positioning pattern 605, and then the colorimetry operation is initiated. For the gradation patterns of the second color and thereafter, there is no need to determine the starting position using the positioning pattern 605 each time. The amount of transport of the printing medium is determined from the relative position information of the gradation patterns for each ink color, and the printing medium is transported to the first gradation.

[0077] Fig. 10 shows transport control that is performed in parallel with the colorimetry operation by the colorimetry unit 109. Fig. 10(a) shows the operation of the colorimetry unit 109 when performing colorimetry, in which the colorimetry unit 109 performs colorimetry at regular distances while moving the colorimetry machine 110 in the X-axis direction (horizontal to the paper surface) with the transport of the print medium stopped. After completing colorimetry of the entire area of ​​one line of gradation pattern, the colorimetry unit 109 stops the colorimetry machine 110 when it reaches the trigger pattern 606 at the end. Based on the measured colorimetry values, the colorimetry machine 110 can determine the trigger mark by, for example, observing fluctuations in luminance values.

[0078] Next, as shown in FIG. 10(b), the recording device 100 transports the print medium to the line of the next gradation. The transport length at this time can be determined by, for example, estimating the transport distance for one gradation line based on the motor rotation speed. After transport for one gradation line is completed, the colorimetric unit 109 performs color measurement while moving the colorimetric device 110 along the X-axis direction in the opposite direction to that shown in FIG. 10(a), as shown in FIG. 10(c). After completing color measurement for the entire area of ​​one line of the gradation pattern, the recording device 100 transports the print medium again to the line of the next gradation, as shown in FIG. 10(d). When measuring the colorimetry pattern using the colorimetric device 110, the operations shown in FIGS. 10(a) to 10(d) are repeated to measure the colorimetry for the entire area of ​​the colorimetry pattern.

[0079] In this embodiment, trigger patterns are arranged at the left and right ends of each gradation in the X-axis direction, but the trigger pattern may be arranged only on either the left or right side for each gradation, and only the end side of the movement of the colorimeter 110 may be determined. After completing colorimetry of the colorimetry patterns 503 for all target colors, the colorimetry operation ends.

[0080] After the color measurement of the color measurement pattern 503 is completed, the scanner correction pattern is conveyed downstream in the conveyance direction of the print medium, and the measurement operation of the scanner correction pattern by the recording apparatus 100 is completed.

[0081] 11 shows the positional relationship between the scanner unit 108, the colorimetry unit 109, and the scanner correction pattern 1101 at the time when the scanner unit 108 has completed scanning the conventional scanner correction pattern. In other words, in the state shown in FIG. 11, the scanner unit 108 has finished scanning the rear end of the scanner correction pattern 1101. The conventional scanner correction pattern 1101 is a common pattern that is read by both the scanner unit 108 and the colorimetry unit 109.

[0082] If the length 1102 of the scanner correction pattern 1101 in the Y-axis direction is greater than the length 1103 from the scanner unit 108 to the colorimetric unit 109, a portion of the scanner correction pattern 1101 will have passed the position of the colorimeter 110 in the colorimetric unit 109 when the scanner unit 108 has completed scanning of the scanner correction pattern 1101. The scanner unit 108 and the colorimetric unit 109 have different transport controls during measurement, so they cannot perform measurements simultaneously. Therefore, when performing color measurement by the colorimetric unit 109 after the scanner unit 108 has completed scanning of the scanner correction pattern 1101, a rewinding operation of the print medium is required. Rewinding the print medium increases the time required to transport the print medium, and rewinding can cause unstable transport control, potentially reducing accuracy.

[0083] On the other hand, according to this embodiment, a measurement pattern is prepared for each of the scanner unit 108 and the colorimetric unit 109, and after scanning by the scanner unit 108 is completed, there is a sufficient length between the colorimetric device 110 in the colorimetric unit 109 and the colorimetric pattern 503 to switch the transport control to the transport speed for starting colorimetric measurement by the colorimetric unit 109, so that it is possible to transition to colorimetric measurement by the colorimetric unit 109 without rewinding the printing medium.

[0084] Next, generation of the scanner correction table will be described. The printing device 100 generates the scanner correction table based on the scan data obtained by scanning in step S803 and the colorimetric data, which is spectral reflectance data obtained by colorimetric measurement in step S805. The process of generating the scanner correction table by the printing device 100 will be described with reference to the flowchart in FIG.

[0085] In step S1201, CPU 311 detects the reading position of the colorimetric data. In detecting the reading position of the colorimetric data, first, the position of each colorimetric value in the X-axis direction is obtained using the end position obtained by the trigger mark of colorimetric pattern 503 as a reference. Colorimetric measurement is performed at regular intervals in the X-axis direction, and the position of each measurement point in the X-axis direction can be identified from the number of measurements in the X-axis direction within each gradation line on gradation pattern 604 using trigger pattern 606 as a reference. This also makes it possible to identify the center position of each gradation line in the X-axis direction.

[0086] In step S1202, CPU 311 generates line profiles of the colorimetry data. Specifically, CPU 311 obtains line profiles for each gradation line, the number of which corresponds to the number of colorimetry points in the X-axis direction, and uses these as colorimetry line profiles for each gradation (hereinafter simply referred to as colorimetry line profiles). According to this embodiment, this allows for the acquisition of colorimetry line profiles of five gradations for each colorimetry point in the X-axis direction.

[0087] In step S1203, the CPU 311 detects the read position of the scan data. In detecting the read position of the scan data, first, the gradation pattern 601 for each ink color in the scan pattern 502 is identified from the scan image.

[0088] Position identification patterns 602 and 603 are used to identify the position of the gradation pattern 601 for each color. Possible methods for detecting the position identification patterns include identifying and detecting rectangles and crosses by detecting the vertices of each color in the scanned image and comparing them with an area threshold. By detecting the upper and lower position identification patterns, the area between them is identified as the gradation pattern 601 of the target color based on relative position information. Furthermore, if the cross pattern is set as the center position of the position identification pattern, it is possible to estimate the position in the X-axis direction from the relative positions of each rectangle within the position identification pattern. If the detected positions of the upper and lower position identification patterns are compared and it is determined that the colorimetric gradation pattern is tilted, processing to maintain horizontality may be performed, such as rotating the scan line profile or acquiring scan values ​​that take the tilt into account when calculating the average one-dimensional data.

[0089] In step S1204, CPU 311 generates a line profile of the scan data. Specifically, scan average one-dimensional data is obtained by averaging the sensor values ​​in the transport direction (Y-axis direction) for each gradation in the gradation pattern. The scan average one-dimensional data is obtained by averaging the read values ​​of each gradation for each scan pixel row in the X-axis direction, and this is used as a scan line profile. According to this embodiment, this makes it possible to obtain a line scan profile of five gradations for each scan pixel row in the X-axis direction.

[0090] In step S1205, the CPU 311 aligns the scan line profile with the colorimetry line profile. FIG. 13 is a diagram showing the respective center positions of the scanning gradation pattern 601 and the colorimetry gradation pattern 604. As shown in FIG. 13(a), the position of the detected cross mark in the scanning gradation pattern 601 can be determined as the center position, and in the scan line profile, the scan pixel row at the same position is the center position 1301. As shown in FIG. 13(b), in the colorimetry line profile, a point 1302 corresponding to the center position can be estimated from the number of colorimetry points 1303 in the X-axis direction using the trigger pattern 606 as a reference, and the relative position from the center position for each colorimetry value in the colorimetry line profile can be determined. The alignment of the scan line profile with the colorimetry line profile can be achieved by associating their respective center positions.

[0091] In step S1206, CPU 311 performs resolution conversion on each of the scan line profile and the colorimetric line profile. Specifically, CPU 311 performs resolution conversion by averaging so that the scan line profiles have a common resolution in the X-axis direction. The averaging in the X-axis direction does not need to use all of the scan pixel rows; it may be performed using only the scan pixel rows near the X position of the colorimetric line profile as a reference.

[0092] In the Y-axis direction, the CPU 311 performs processing to expand the number of gradations through interpolation so that the resolutions of the scan line profile and the colorimetric line profile are the same. In this embodiment, both the scan line profile and the colorimetric line profile are five-level line profiles, and in consideration of the accuracy of scan correction table generation, both are expanded to, for example, 256 levels. As for the interpolation to expand the number of gradations, in addition to simple linear interpolation, any interpolation method such as multidimensional interpolation may be freely selected.

[0093] In step S1207, the CPU 311 derives the correction amount for the pixel position of interest and determines the corrected sensor value for the pixel position of interest. This process determines the corrected pixel values ​​for each column in the X-axis direction of the scan line profile, for example, "0, 29, 40,..., 240, 255," which are the output values ​​when pixel position X=0.

[0094] The derivation of the correction amount in step S1207 will be described using Figure 14. Figures 14(a) and 14(b) are both graphs with the colorimetric value (L*) on the horizontal axis and the sensor value (G channel value) of the G sensor of the RGB sensors that make up the line sensor on the vertical axis.

[0095] The graph in FIG. 14(a) shows points 1401a to 1405a plotting the colorimetric values ​​(L*) and G channel values ​​at each gradation position of the gradation pattern. For example, point 1401a represents the colorimetric value (L*) and G channel value for the paper white gradation. Point 1402a represents the colorimetric value (L*) and G channel value for the lightest gray measurement area, and point 1405a represents the colorimetric value (L*) and G channel value for the darkest gray measurement area. Curve 1406 in FIG. 14(a) is a curve obtained by applying interpolation or approximation processing, such as piecewise linear interpolation or known spline interpolation, to the plotted points 1401a to 1405a. Curve 1407 in FIG. 14(a) is a target reading characteristic representing the target value of the corrected sensor value. The target value is calculated, for example, from the colorimetric value and scan value corresponding to any one of positions X. In FIG. 14(a), points 1401b to 1405b are plots of the colorimetric values ​​at the X position as target values ​​and the corresponding sensor values. Curve 1407, like curve 1406, can be obtained by interpolating or approximating points 1401b to 1405b. A curve representing the reading characteristics of a reference sensor may be stored in advance as the target reading characteristics. Alternatively, a curve representing the sensor values ​​that are linear with respect to luminance, L*, and optical density may be previously determined and stored.

[0096] FIG. 14B shows how the corrected sensor value is determined from the two curves 1406 and 1407 thus obtained. In FIG. 14B, a G channel value 1408 represents the sensor value before correction. First, a colorimetric value L* 1409 corresponding to the G channel value 1408 is obtained from the curve 1406. Next, a target G channel value 1410 corresponding to the colorimetric value L* 1409 is obtained from the target curve 1407. The target G channel value 1410 thus obtained and the pre-correction G channel value 1408 are associated with each other and stored in RAM 312 or the like in a scanner correction table being generated, linked to the pixel position of interest. However, if the pre-correction sensor value is 0 or the maximum output value (e.g., 255), it may be forcibly set to 0 or the maximum output value. By repeating this process for the number of columns in the X direction of the scan line profile, a correction table for each column in the X direction of the scan line profile for each ink color, as shown in FIG. 15, is determined.

[0097] Then, by performing this process for each ink color of CMYK, a scanner correction table corresponding to each ink color is obtained. Note that the generation of scanner correction tables does not necessarily have to be performed for all ink colors. For example, scanner correction tables may be generated only for specific ink colors that have been determined in advance.

[0098] In this embodiment, a method for generating a scanner correction table is described assuming that the scanner unit 108 has one scanner. However, if the scanner unit 108 has multiple scanners, generating a scanner correction table for each scanner makes it possible to correct the scan pixel values ​​across the entire width of the printing medium.

[0099] Scanner reading characteristics often depend on the angle of incidence of the sensor pixels and color filters within the scanner, resulting in gradually increasing or decreasing read values ​​depending on the position of the sensor pixels. Figures 16(a) to 16(d) are graphs with pixel position X on the horizontal axis and sensor values ​​(scan values) on the vertical axis, showing the variation in scan values ​​relative to pixel position X. Each curve on the graph shows an example of scan values ​​for each pixel position X when reading a line of a gradation pattern with spectral reflectance on a print medium corresponding to one gradation level. The higher the reflectance (i.e., closer to white paper), the larger the scan value, and the lower the reflectance (i.e., higher density on the print medium), the smaller the scan value. As shown in Figures 16(a) and 16(b), the curve corresponding to a gradation pattern with a smaller scan value often exhibits a larger deviation between the center and edges along the X axis. In other words, the higher the color signal value and the higher the image density on the print medium, the greater the difference in scanner reading characteristics. One possible cause of this is that the incident angle to the scanner sensor is larger at the edges, resulting in a longer optical path through the color filters of the sensor pixels. Specifically, the spectral distribution of light incident on the sensor due to the color filters is greater at the edges than at the center, resulting in a change in the sensor value. On the other hand, when the incident angle to the sensor is large, light that should be incident on the G sensor may enter the adjacent B sensor as stray light. If these multiple factors occur simultaneously, the overall shape of the scanner's reading characteristics (convex upward and convex downward) may change depending on the average scan value, as shown in Figure 16(c). Therefore, it is preferable that the gradation patterns of the scanning pattern 502 and the colorimetric pattern 503 each include a measurement area that is uniform across multiple color signal values. Furthermore, if the internal structure of the scanner unit 108 is not symmetrical, the results may be asymmetrical, as shown in Figure 16(d).

[0100] Next, a method for correcting scan data acquired by the scanner unit 108 using the generated scanner correction table will be described. In the scanner correction table of FIG. 15 , corrected scan values ​​corresponding to each scan value (0, 16, 32, ..., 240, 255) included in the scan data are stored in association with pixel positions in the X-axis direction (0, 100, 200, 300, 400, ..., 1000, ...). For example, if the pixel value at pixel position "100" is "32," the corrected pixel value of the scan data will be "39." Note that pixel values ​​not specified in the scanner correction table shown in FIG. 15 are calculated by interpolation using correction values ​​for adjacent pixel positions among the specified values. Similarly, scan values ​​for pixel positions not included in the scanner correction table are calculated by interpolation using adjacent values ​​among the specified values. Of course, correction values ​​for all pixel positions and pixel values ​​may be stored without interpolation. Note that correction processing for the scanner correction table can also be performed using function transformation or matrix transformation instead of a table format.

[0101] Next, the scan data is corrected using the scanner correction table based on the pixel position in the X-axis direction. As an example, assume that the scan pixel value is "24" when pixel position X=50 in the X-axis direction. In this case, the scan correction value for the scan value "24" at pixel positions X=0 and X=100 is first calculated by interpolation. Specifically, for pixel position X=0, the correction value is calculated as 29 + (40 - 29) x (24 - 16) / (32 - 16) = 34.5 from the correction values ​​"29" and "40" corresponding to pixel values ​​"16" and "32." Similarly, the correction value for pixel position X=100 is calculated as 32.0. Then, from the two calculated correction values ​​"34.5" and "32.0," the correction value for pixel position X=50 is calculated as 32.0 + (34.5 - 32.0) x (100 - 50) / (100 - 0) = 33.25. In this way, by calculating the correction value for each pixel position in the X-axis direction for the scan value based on the scanner correction table, corrected scan data can be obtained. Note that the application of the scanner correction table does not need to be limited to the scan data itself, and it may also be applied to, for example, a scan line profile generated from the scan data.

[0102] [Second embodiment] The following describes the differences from the first embodiment, and unless otherwise specified below, it is assumed that the present embodiment is the same as the first embodiment. In the first embodiment, the colorimetry unit 109 is provided downstream of the scanner unit 108 in the transport direction of the print medium, and the scan pattern 502 in the scanner correction pattern is printed downstream of the colorimetry pattern 503 in the transport direction of the print medium.

[0103] However, the order of the colorimetry unit 109 and the scanner unit 108 in the transport direction of the print medium, and the order of the scanning pattern 502 and the colorimetry pattern 503 in the transport direction of the print medium are not limited to the above cases. In this embodiment, other cases of such an order will be described.

[0104] 17A shows the positional relationship between the scanner unit 108, the colorimetry unit 109, the scanning pattern 502, and the colorimetry pattern 503 at the time when the scanner unit 108 has completed scanning the scanning pattern 502 when measurements are performed on the scanner correction pattern in the order of scanning and colorimetry. In other words, Fig. 17A shows a case where the arrangement order of the scanner unit 108 and the colorimetry unit 109 is reversed from that of the first embodiment (Fig. 7). Here, the order of measurements of the scanning patterns and colorimetry patterns in the scanner correction pattern is such that measurements are performed in order starting from the pattern arranged downstream in the transport direction of the printing medium.

[0105] In the case of Figure 17A, when measuring the colorimetry pattern 503 immediately after completing the scanning of the scan pattern 502, the remaining distance 1702a obtained by subtracting the distance 1701a between the colorimetry unit 109 (colorimetry machine 110) and the scanner unit 108 from the length of the margin area 504 in the transport direction (Y-axis direction) must be greater than or equal to the transport distance required to switch the transport control.

[0106] In other words, the recording device 100 simply prints the colorimetry pattern 503 on the printing medium so that the length of the marginal area 504 in the transport direction (Y-axis direction) is equal to or greater than the sum of the distance between the colorimetry unit 109 (colorimeter 110) and the scanner unit 108 and the transport distance required to switch transport control. For example, the length of the marginal area 504 in the Y-axis direction must satisfy the following formula (2).

[0107] (length of margin area 504 in the Y-axis direction)= (Transport distance required for switching transport control) + (distance between the colorimeter 109 (colorimeter 110) and the scanner 108) ... (2) Therefore, after printing the scanning pattern 502, the recording device 100 sets the margin area 504 so that the length of the margin area 504 in the Y-axis direction satisfies equation (2) (or so that the left side of equation (2) is greater than the right side), and then prints the colorimetry pattern 503.

[0108] For example, if the transport distance required to switch transport control is 1400 mm and the distance between the scanner unit 108 and the colorimeter 110 is 400 mm, the length of the required margin area 504 in the Y-axis direction is 1400 mm + 400 mm = 1800 mm (or more than 1800 mm).

[0109] 17B shows the positional relationship between the scanner unit 108, the colorimetric unit 109, the scanning pattern 502, and the colorimetric measurement pattern 503 at the time when the colorimetric unit 109 completes colorimetric measurement of the colorimetric measurement pattern 503 when measurements are performed on the scanner correction pattern in the order of colorimetric measurement and scanning. In other words, Fig. 17B shows a case in which the order of the scanning pattern 502 and the colorimetric measurement pattern 503 is reversed from that of Fig. 17A.

[0110] In the case of Figure 17B, when scanning the scan pattern 502 subsequently after completing color measurement of the color measurement pattern 503, the distance 1702b obtained by adding the distance 1701b between the color measurement unit 109 (colorimeter 110) and the scanner unit 108 and the length of the margin area 504 in the transport direction (Y-axis direction) must be greater than or equal to the transport distance required to switch the transport control.

[0111] In other words, the recording apparatus 100 simply prints the scanning pattern 502 on the print medium so that the sum of the distance 1701b between the colorimetric unit 109 (colorimeter 110) and the scanner unit 108 and the length of the marginal area 504 in the transport direction (Y-axis direction) of the recording medium 100 is equal to or greater than the transport distance required to switch transport control. For example, the length of the marginal area 504 in the Y-axis direction must satisfy the above formula (1).

[0112] Therefore, after printing the color measurement pattern 503, the recording device 100 sets the margin area 504 so that the length of the margin area 504 in the Y-axis direction satisfies equation (1) (or so that the left side of equation (1) is greater than the right side), and then prints the scanning pattern 502.

[0113] 17C shows the positional relationship between the scanner unit 108, the colorimetric unit 109, the scanning pattern 502, and the colorimetric pattern 503 at the time when the colorimetric unit 109 completes colorimetric measurement of the colorimetric pattern 503 when measurements are performed on the scanner correction pattern in the order of colorimetric measurement and scanning. Fig. 17C shows a case in which the order of the scanner unit 108 and the colorimetric unit 109 is reversed from that of Fig. 17B.

[0114] In the case of Figure 17C, when scanning the scan pattern 502 subsequently after completing color measurement of the color measurement pattern 503, the remaining distance 1702c obtained by subtracting the distance 1701c between the color measurement unit 109 (colorimeter 110) and the scanner unit 108 from the length of the margin area 504 in the transport direction (Y-axis direction) must be greater than or equal to the transport distance required to switch the transport control.

[0115] In other words, the recording apparatus 100 simply prints the scanning pattern 502 on the print medium so that the remaining distance 1702c, obtained by subtracting the distance 1701c between the colorimetric unit 109 (colorimeter 110) and the scanner unit 108 from the length of the marginal area 504 in the transport direction (Y-axis direction), is equal to or greater than the transport distance required to switch transport control. For example, the length of the marginal area 504 in the Y-axis direction must satisfy the above formula (2).

[0116] Therefore, after printing the color measurement pattern 503, the recording device 100 sets the margin area 504 so that the length of the margin area 504 in the Y-axis direction satisfies equation (2) (or so that the left side of equation (2) is greater than the right side), and then prints the scanning pattern 502.

[0117] In this way, the margin area is determined according to the arrangement order of the scanner unit 108 and the colorimetry unit 109 on the transport path and the arrangement order of the scanning patterns and colorimetry patterns in the scanner correction pattern, thereby making it possible to measure the scanner correction pattern with a single transport that does not involve rewinding, regardless of the respective arrangement orders.

[0118] The numerical values, processing timing, processing order, processing subject, data (information) configuration / acquisition method / sending destination / sending source / storage location, etc. used in the above embodiment are given as examples to provide a concrete explanation, and are not intended to be limited to these examples.

[0119] In addition, some or all of the embodiments described above may be used in appropriate combination, and some or all of the embodiments described above may be selectively used.

[0120] (Other embodiments) The present invention can also be realized by supplying a program that realizes one or more functions of the above-described embodiments to a system or device via a network or a storage medium, and having one or more processors in the 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 realizes one or more functions.

[0121] The invention of this specification includes the following printing apparatus, printing apparatus control method, and measurement pattern. (Item 1) a transport control means for controlling the transport of the print medium; a printing means for printing a first pattern and a second pattern including overlapping gradation ranges on a printing medium in a single conveyance; a first measuring means for measuring the first pattern on the print medium transported under first transport control by the transport control means; a second measuring means for measuring the second pattern on the print medium transported under second transport control by the transport control means; Equipped with The printing means After printing the first pattern, the second pattern is printed so that the distance between the second measuring means and the second pattern at the start of switching from the first transport control to the second transport control is equal to or greater than a transport distance over which the print medium is transported during switching from the first transport control to the second transport control. A recording device characterized by: (Item 2) The recording device described in item 1 is characterized in that the printing means prints the second pattern so that the distance between the first measurement means and the second measurement means plus the length of the margin area between the first pattern and the second pattern in the transport direction is equal to or greater than the transport distance. (Item 3) the first measuring means is provided upstream of the second measuring means in a print medium transport direction, The first pattern is printed downstream of the second pattern in the transport direction of the print medium. 3. The recording device according to item 2. (Item 4) 4. The recording device according to item 2 or 3, wherein the first pattern is a pattern for scanning, and the second pattern is a pattern for color measurement. (Item 5) 4. The recording device according to item 2 or 3, wherein the first pattern is a pattern for color measurement, and the second pattern is a pattern for scanning. (Item 6) The recording device described in item 1 is characterized in that the printing means prints the second pattern so that the length of the margin area between the first pattern and the second pattern in the transport direction is equal to or greater than the sum of the distance between the first measurement means and the second measurement means and the transport distance. (Item 7) the first measuring means is provided downstream of the second measuring means in a print medium transport direction, The first pattern is printed downstream of the second pattern in the transport direction of the print medium. 7. The recording device according to item 6, (Item 8) 8. The recording device according to item 6 or 7, wherein the first pattern is a pattern for scanning, and the second pattern is a pattern for color measurement. (Item 9) 8. The recording device according to item 6 or 7, wherein the first pattern is a pattern for color measurement, and the second pattern is a pattern for scanning. (Item 10) 10. The recording device according to any one of items 1 to 9, wherein the print medium is roll paper. (Item 11) a transport control means for controlling the transport of the print medium; a printing means for printing a first pattern and a second pattern including overlapping gradation ranges on a printing medium in a single conveyance; a first measuring means for measuring the first pattern on the print medium transported under first transport control by the transport control means; a second measuring means for measuring the second pattern on the print medium transported under second transport control by the transport control means; A control method for a recording device comprising: The printing means After printing the first pattern, the second pattern is printed so that the distance between the second measuring means and the second pattern at the start of switching from the first transport control to the second transport control is equal to or greater than a transport distance over which the print medium is transported during switching from the first transport control to the second transport control. A method for controlling a recording apparatus. (Item 12) A measurement pattern including a first pattern and a second pattern, The distance between the second pattern and the measuring means for the second pattern at the start of switching from print medium transport control for measuring the first pattern to print medium transport control for measuring the second pattern is equal to or greater than the transport distance by which the print medium is transported at the time of switching. A measurement pattern characterized by:

[0122] The invention is not limited to the above-described embodiments, and various changes and modifications can be made without departing from the spirit and scope of the invention. Accordingly, the following claims are appended to apprise the public of the scope of the invention. [Explanation of symbols]

[0123] 100: Recording device 300: Host PC 301: CPU 302: RAM 303: ROM 304: Communication I / F 305: Input device I / F 306: Display device I / F 307: System bus 311: CPU 312: RAM 313: ROM 314: Communication I / F 315: Head controller 316: Image processing accelerator 317: Scanner device 318: Color measurement device 319: System bus

Claims

1. a transport control means for controlling the transport of the print medium; a printing means for printing a first pattern and a second pattern including overlapping gradation ranges on a printing medium in a single conveyance; a first measuring means for measuring the first pattern on the print medium transported under first transport control by the transport control means; a second measuring means for measuring the second pattern on the print medium transported under second transport control by the transport control means; Equipped with The printing means After printing the first pattern, the second pattern is printed so that the distance between the second measuring means and the second pattern at the start of switching from the first transport control to the second transport control is equal to or greater than a transport distance over which the print medium is transported during switching from the first transport control to the second transport control. A recording device characterized by:

2. 2. The recording device according to claim 1, wherein the printing means prints the second pattern so that the sum of the distance between the first measuring means and the second measuring means and the length of the margin area between the first pattern and the second pattern in the transport direction is equal to or greater than the transport distance.

3. the first measuring means is provided upstream of the second measuring means in a print medium transport direction, The first pattern is printed downstream of the second pattern in the transport direction of the print medium.

3. The recording apparatus according to claim 2.

4. 3. The recording apparatus according to claim 2, wherein the first pattern is a pattern for scanning, and the second pattern is a pattern for color measurement.

5. 3. The recording apparatus according to claim 2, wherein the first pattern is a pattern for color measurement, and the second pattern is a pattern for scanning.

6. 2. The recording device according to claim 1, wherein the printing means prints the second pattern so that the length of the margin area between the first pattern and the second pattern in the transport direction is equal to or greater than the sum of the distance between the first measuring means and the second measuring means and the transport distance.

7. the first measuring means is provided downstream of the second measuring means in a print medium transport direction, The first pattern is printed downstream of the second pattern in the transport direction of the print medium.

7. The recording apparatus according to claim 6.

8. 7. The recording apparatus according to claim 6, wherein the first pattern is a pattern for scanning, and the second pattern is a pattern for color measurement.

9. 7. The recording apparatus according to claim 6, wherein the first pattern is a pattern for color measurement, and the second pattern is a pattern for scanning.

10. 2. The recording apparatus according to claim 1, wherein the print medium is roll paper.

11. a transport control means for controlling the transport of the print medium; a printing means for printing a first pattern and a second pattern including overlapping gradation ranges on a printing medium in a single conveyance; a first measuring means for measuring the first pattern on the print medium transported under first transport control by the transport control means; a second measuring means for measuring the second pattern on the print medium transported under second transport control by the transport control means; A control method for a recording device comprising: The printing means After printing the first pattern, the second pattern is printed so that the distance between the second measuring means and the second pattern at the start of switching from the first transport control to the second transport control is equal to or greater than a transport distance over which the print medium is transported during switching from the first transport control to the second transport control. A method for controlling a recording apparatus.

12. A measurement pattern including a first pattern and a second pattern, The distance between the second pattern and the measuring means for the second pattern at the start of switching from print medium transport control for measuring the first pattern to print medium transport control for measuring the second pattern is equal to or greater than the transport distance by which the print medium is transported at the time of switching. A measurement pattern characterized by:

Images