Printing apparatus production method, adjustment apparatus, and adjustment program

Abstract

To produce a printer in which a printing unit is highly accurately adjusted.SOLUTION: A printer production method for producing a printer that is adjusted from a printer before adjustment comprises the steps of: causing a printing unit of the printer before adjustment to print a multiple circular pattern and an adjustment pattern at prescribed relative positions on a medium; setting the printed medium relative to a scan unit; scanning the printed medium to generate a scan image; detecting the multiple circular pattern from the scan image and detecting an adjustment pattern on the basis of the relative positions and the detection position of the multiple circular pattern; calculating an adjustment parameter on the basis of the detection result of the adjustment pattern; and storing the adjustment parameter in a non-volatile memory of the printer before adjustment.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a method for producing a printing device, an adjustment device, an adjustment program, and a method for producing a printed matter.

Background Art

[0002] Conventionally, a technique for detecting a printing error by scanning a printing medium on which a specific adjustment pattern is printed by a printing device is known. Patent Document 1 discloses a technique for suppressing density unevenness in a printing device in which a part of a plurality of nozzle rows is arranged overlappingly by using an adjustment pattern (test pattern).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In order to detect a printing error using an adjustment pattern, it is necessary to correctly specify the size, position, inclination, etc. of the adjustment pattern in image analysis of a scanned image of the adjustment pattern printed on a medium.

Means for Solving the Problems

[0005] In view of the above issues, the printing apparatus production method is a method for producing a modified printing apparatus from a printing apparatus before modification, wherein the printing section of the printing apparatus before modification prints a multi-circle pattern and a modification pattern at predetermined relative positions on a medium, the printed medium is set against a scanning section, the printed medium is scanned to generate a scanned image, the multi-circle pattern is detected from the scanned image, the modification pattern is detected based on the relative positions and the detected positions of the multi-circle pattern, modification parameters are calculated based on the detection result of the modification pattern, and the modification parameters are stored in the non-volatile memory of the printing apparatus before modification.

[0006] Another embodiment is an adjustment device for adjusting the printing section of a printing device, comprising: a pattern detection unit that detects the multiple circle pattern and an adjustment pattern used for adjusting the printing section in a scanned image generated by scanning a medium printed at a predetermined relative position by the printing section, and detects the adjustment pattern based on the relative position and the detection position of the multiple circle pattern; and an adjustment unit that stores the adjustment parameters of the printing section based on the detection result of the adjustment pattern in a non-volatile memory.

[0007] Another form is an adjustment program for adjusting the printing unit of a printing device, which causes a computer to function as a pattern detection unit that detects the multiple circle pattern in a scanned image generated by scanning a medium printed at predetermined relative positions by the printing unit, and detects the adjustment pattern based on the detection position of the multiple circle pattern and the relative positions, and an adjustment unit that stores the adjustment parameters of the printing unit in a non-volatile memory based on the detection result of the adjustment pattern.

[0008] Another form is a method for producing printed materials, wherein an identification pattern and a multi-circle pattern are printed on a medium, and the identification pattern and the multi-circle pattern are printed at predetermined relative positions on the medium. [Brief explanation of the drawing]

[0009] [Figure 1] This is a diagram showing the configuration of a multifunction printer. [Figure 2] This diagram shows the positional relationship between the scanning unit and the media. [Figure 3] This is a diagram showing the test pattern. [Figure 4A] This is an explanatory diagram of the multiple circle pattern. [Figure 4B] This is an explanatory diagram of the multiple circle pattern. [Figure 4C] This is an explanatory diagram of the multiple circle pattern. [Figure 5] This is a magnified view of the multi-circle pattern. [Figure 6A] This figure shows the experimental results regarding the degree of pigment bleeding. [Figure 6B] This figure shows the experimental results regarding the degree of dye bleeding. [Figure 7] This is a diagram illustrating the process for determining whether or not the media has moved. [Figure 8] This is a diagram illustrating the process for determining whether or not the media has moved. [Figure 9] This is an explanatory diagram of the change in the tilt of the medium. [Figure 10] This is a flowchart of the production process. [Figure 11A] This is a diagram showing the first modified example. [Figure 11B] This is a diagram showing the first modified example. [Figure 12A] This is a diagram showing the ninth modified example. [Figure 12B] This is a diagram showing the ninth modified example. [Figure 12C] This is a diagram showing the ninth modified example. [Figure 12D] This is a diagram showing the ninth modified example.

Best Mode for Carrying Out the Invention

[0010] FIG. 1 is a configuration diagram of a multifunction device 10 according to the present embodiment. The multifunction device 10 has a printing function and a scanner function. Note that the multifunction device 10 may be provided with other functions such as a FAX. The multifunction device 10 includes a printing unit 11, a scan unit 12, a processor 13, a nonvolatile memory 14, a UI unit 15, and a communication unit 16. The printing unit 11 includes a print head 111, a carriage 112, and a transport mechanism 113.

[0011] The print head 111 includes nozzle arrays corresponding to four types of inks of CMYK (C: cyan, M: magenta, Y: yellow, K: black), and performs printing by an inkjet method. The nozzle arrays include a plurality of nozzles, and inks of each color are ejected from each nozzle. The ink of each nozzle is supplied from an ink tank (not shown) of each color. By ejecting ink from each nozzle of the print head 111, ink droplets (dots) are formed on the medium. The print head 111 is an example of a printing unit.

[0012] The carriage 112 mounts the print head 111, and the carriage 112 reciprocates along a specific direction under the control of the processor 13. Accordingly, the print head 111 reciprocates in a specific direction. The direction in which the print head 111 reciprocates is referred to as the main scanning direction of the print head 111. The transport mechanism 113 is a device that transports the medium to be printed. The transport mechanism 113 transports the medium in a direction perpendicular to the main scanning direction of the print head 111. Here, the direction perpendicular to the main scanning direction of the print head 111, that is, the direction in which the medium is transported, is referred to as the sub-scanning direction of the print head 111.

[0013] In the nozzle arrays of each color of the print head 111, a plurality of nozzles are arranged at equal intervals along the sub-scanning direction. By repeating the ejection of inks of each color from the nozzles during the reciprocating movement of the print head 111 and the transport of the medium by the transport mechanism 113, printing on the medium is performed.

[0014] The scanning unit 12 includes a light source and a light receiving element that receives light from the object to be scanned. In the scanning unit 12 of the present embodiment, a CMOS (Complementary Metal Oxide Semiconductor) line sensor of the CIS (Contact Image Sensor) type is used. As another example, the scanning unit 12 may be a sensor of the CCD (Charge Coupled Device) type. Hereinafter, the arrangement direction of the light receiving elements in the line sensor is referred to as the main scanning direction of the scanning unit 12.

[0015] As shown in FIG. 2, the multifunction device 10 includes a media tray 122 provided with a glass surface 121 on which the object P to be read is placed. That is, the multifunction device 10 includes a flatbed type scanning device including the scanning unit 12, the glass surface 121, and the media tray 122. The scanning unit 12 moves in the direction B perpendicular to the main scanning direction A on the glass surface 121 under the control of the processor 13. Hereinafter, the direction perpendicular to the main scanning direction is referred to as the sub-scanning direction of the scanning unit 12. The scanning unit 12 repeats reading while moving by a predetermined amount in the sub-scanning direction, thereby reading the entire object P. The scanning unit 12 is located at the retracted position (home position) H during the non-reading operation, and starts moving in the sub-scanning direction from the home position H during the reading operation.

[0016] In the present embodiment, it is assumed that the relative position between the object P and the scanning unit 12 changes as the scanning unit 12 moves with respect to the placed object P. However, as another example, the relative position may change by transporting the medium in the sub-scanning direction by the transport mechanism 113 with respect to the fixed scanning unit 12.

[0017] The processor 13 includes RAM, a CPU, etc. The non-volatile memory 14 stores various data and programs. The processor 13 can execute programs stored in the non-volatile memory 14. The UI unit 15 includes an input unit for receiving user input and a display unit for displaying various information to the user. The communication unit 16 communicates with external devices such as PCs and tablet terminals connected via wired communication or wireless communication.

[0018] In the multifunction printer 10 of this embodiment, the printing unit 11 prints a test pattern onto a medium. Here, the test pattern is an image in which a predetermined pattern is shown at predetermined positions. The multifunction printer 10 can adjust the control content of the printing unit 11 by scanning the medium on which this test pattern is printed and performing image analysis. This process will be described in detail later. Examples of adjustments to the control content include adjusting the media transport misalignment (PF misalignment, Paper Feed misalignment) and adjusting the dot formation position misalignment (Bi-D) caused by the relative positional movement of the printing unit 11 and the medium during reciprocal movement in the main scanning direction. Note that the target of adjustment is not limited to this embodiment, as long as it is a mechanism from which a physical quantity can be identified from the test pattern.

[0019] The processor 13 of this embodiment includes a print control unit 131, a scan control unit 132, a detection unit 133, an adjustment unit 134, and a stop state analysis unit 135 as a functional configuration for adjusting the print unit 11 using a test pattern. The functions of the print control unit 131, scan control unit 132, detection unit 133, adjustment unit 134, and stop state analysis unit 135 are realized by the processor 13 reading the adjustment program 130 stored in the non-volatile memory 14 and executing it. In other words, the processes described below as being executed by the print control unit 131, scan control unit 132, detection unit 133, adjustment unit 134, and stop state analysis unit 135 are processes executed by the processor 13.

[0020] The print control unit 131 controls the print unit 11. The scan control unit 132 controls the scan unit 12. The detection unit 133 detects a predetermined pattern in the scanned image. The adjustment unit 134 adjusts the print unit 11 based on the pattern detection result by the detection unit 133. The stop state analysis unit 135 performs state analysis in the stop state when the scan unit 12 is performing intermittent scanning, where the movement of the scan unit 12 is temporarily paused. Intermittent scanning is a scan in which the movement of the scan unit 12 in the sub-scanning direction and the illumination (lighting) by the light source are temporarily paused and then resumed, and so on, repeatedly pausing and resuming movement and illumination. Intermittent scanning is performed when there is insufficient memory space to hold the scanned image of the entire medium.

[0021] In intermittent scanning, when the movement and illumination of the scan unit 12 in the sub-scanning direction are temporarily paused, the scan image obtained up to that point (a portion of the scan image of the entire medium) is recorded in memory, and image analysis (pattern matching) is performed on that image. After the image analysis is completed, the scan image recorded in memory is deleted, and the movement and illumination in the sub-scanning direction resume from the paused stop position. This allows pattern matching across the entire scan image to be performed with a limited memory capacity. The processing of each functional component will be described in detail later.

[0022] Figure 3 shows an example of a test pattern according to this embodiment. The print head 111 prints the test pattern 300 onto the medium under the control of the print control unit 131. The image data of the test pattern 300 is assumed to be stored in the non-volatile memory 14 beforehand. Alternatively, the image data of the test pattern 300 may be stored in an external device and transmitted from the external device to the multifunction printer 10.

[0023] The test pattern 300 includes multiple adjustment patterns 310 for adjusting the printing unit 11. The test pattern 300 also includes a multi-circle pattern 220. The multi-circle pattern 220 is a pattern in which the circumferences of multiple concentric circles with different radii are shown in black. The shape of the multi-circle pattern 220 will be described in detail later. The multi-circle pattern 220 is placed at predetermined relative positions with respect to the adjustment patterns 310 so as to be in a known positional relationship with the adjustment patterns 310. Therefore, by detecting the multi-circle pattern 220, it becomes possible to predict the range in which the adjustment patterns 310 exist, and the search time for the adjustment patterns 310 can be shortened.

[0024] Furthermore, in order to adjust the printing unit 11, the position, size, and tilt of the adjustment pattern 310 printed on the medium must be accurately determined from the scanned image. The multi-circle pattern 220 is used to accurately determine the position and size of the adjustment pattern 310 from the scanned image.

[0025] In this embodiment, four multiple circle patterns 220 are arranged at four positions T1 to T4 for one adjustment pattern 310. T1 to T4 are located at the vertices of a rectangle whose two sides are the main scanning direction and the sub-scanning direction. In this way, the four multiple circle patterns 220 are arranged to form a rectangle of known size.

[0026] For example, the relative position relationship (relative positional relationship) between the position T1 of the multi-circle pattern 220 and the upper-left vertex 211 of the adjustment pattern 310 is pre-set. Therefore, the processor 13 can use the position of the multi-circle pattern 220 as a guide to perform pattern detection of the adjustment pattern 310. Furthermore, as described above, the processor 13 can identify and correct distortions, tilts, etc., in the scanned image based on the scan results of the four rectangular multi-circle patterns 220 and the known size of the rectangle.

[0027] Here, the processing of the detection unit 133 will be explained. Detection of the multiple circle pattern 220 is performed by pattern matching with image data (reference pattern) of the multiple circle pattern 220 that is stored in the non-volatile memory 14 in advance. In pattern matching, the detection unit 133 first sets a range of a predetermined number of pixels as a comparison area in the scanned image, which is the area around the position where the reference pattern is expected to exist based on the relative positional relationship from the upper left vertex 211, and performs a comparison with the reference pattern in each comparison area while shifting the comparison area by pixel units.

[0028] Specifically, the detection unit 133 compares the pixel values ​​(luminance) of corresponding pixels in the comparison area and the reference pattern. The detection unit 133 then calculates the sum of the absolute differences in each pixel value (luminance) obtained from the comparison. Theoretically, if there is a perfect match, the sum of the differences will be zero. Based on the sum of the differences, the detection unit 133 calculates the match rate. The match rate is set to 100% when the sum of the differences is zero, and decreases as the sum of the differences increases. The detection unit 133 then detects the comparison area with the maximum match rate as the range of the multi-circle pattern 220, and identifies the center of this range as the multi-circle pattern position. This process is repeated to detect four multi-circle patterns that surround the target adjustment pattern.

[0029] The detection unit 133 then detects the adjustment pattern based on the detection results of the four multi-circle patterns, i.e., the detection positions of the multi-circle patterns. Specifically, the detection unit 133 predicts the range in which the adjustment pattern exists based on the pre-set relative positional relationship between the four multi-circle patterns and the adjustment pattern. As described above, the detection unit 133 adjusts the distortion and tilt of the adjustment pattern in the detection results of the scanned image based on the detection results of the four multi-circle patterns. By setting a comparison area based on the upper left vertex 211, the processing required to search for the multi-circle patterns can be reduced. As a result, the position of the adjustment pattern can be determined with high accuracy by detecting the multi-circle patterns with high accuracy. This makes it possible to adjust the printing unit 11 with high accuracy using less processing.

[0030] Next, the multiple circle pattern will be explained with reference to Figures 4A, 4B, 4C, 5, 6A, and 6B. In the multifunction printer 10 of this embodiment, the multiple circle pattern is used as a position correction pattern for correcting the position of the adjustment pattern. There are three problems in detecting the position correction pattern, as shown below. 1) Decreased accuracy of pattern matching due to the tilt of the medium during scanning. 2) Missing print image due to nozzle clogging 3) Decreased positional accuracy due to ink bleeding

[0031] Even when these situations occur, it is necessary to be able to accurately detect the position of the position correction pattern. Regarding the first problem, as a position correction pattern, patterns such as squares, triangles, or X shapes, which reduce the match rate when the medium is tilted, are undesirable, and therefore circular patterns are preferred.

[0032] However, in the case of a circular pattern filled with a single color, for example, as in the second problem, if a part of it is missing due to nozzle clogging, the position of the position correction pattern may be incorrectly identified.

[0033] For example, as shown in Figure 4A, suppose the upper half of the circle is missing due to nozzle failure. The dashed line indicates the missing portion. When half is missing in this way, as shown in Figure 4B, in the pattern matching of the filled circle, the brightness values ​​become close between pixels that do not actually match in the pattern matching between the semicircular comparison area 2211 and the entire circle (reference pattern) 2212. As a result, a significant difference in the match rate is not easily observed between the comparison area that should match and the comparison area that should not match, and therefore, the wrong position is identified as the location of the multi-circle pattern.

[0034] In contrast, as shown in Figure 4C, the multi-circle pattern has multiple edges, so in pattern matching between the comparison area that does not actually match and the reference pattern, there are more pixels whose brightness does not match between pixels compared to a filled circle, resulting in a higher match rate. Therefore, the center position can be identified with higher accuracy compared to a filled circle. For these reasons, the multifunction printer 10 of this embodiment uses a multi-circle pattern as the position correction pattern.

[0035] Figure 5 is an enlarged view of the multi-circle pattern 220 according to this embodiment. The multi-circle pattern 220 according to this embodiment is a pattern showing double circles. The multi-circle pattern 220 is a pattern showing two circular lines 2201 and 2202 with equal centers but different radii. As shown in Figure 5, the multi-circle pattern 220 is a pattern in which the circumference is drawn with black lines. In this case, the black parts of the circumference are shown with hatching.

[0036] Assume that the adjustment pattern requires a specificity accuracy of less than 1 pixel at 600 dpi. In this case, the resolution during scanning and printing must both be 600 dpi. When the resolution during scanning and printing is 600 dpi, the distance D between the two circular lines 2201 and 2202 is assumed to be the length of 7 pixels. More preferably, the distance D between the lines may be 7 pixels or more, and even 8 pixels or more. Furthermore, the thickness E of the lines drawing the two circular circumferences is assumed to be the length of 7 pixels. More preferably, the thickness of the lines may be 7 pixels or more, and even 8 pixels or more.

[0037] The reason for setting the spacing D of the lines around the circumference to 7 pixels is to address the third problem mentioned above. By setting the line spacing D to 7 pixels, it is possible to avoid misrecognition in the area pattern matching that should be the spacing around the circumference due to ink bleeding. In this way, by providing sufficient spacing, the position of the multi-circle pattern can be correctly identified even if ink bleeding occurs. Furthermore, by setting the line thickness to 7 pixels or more, it is possible to accurately recognize both the areas with and without ink in the image recognition of the scanned image of the test pattern.

[0038] Figures 6A and 6B show experimental results evaluating the degree of ink bleeding when the line spacing and line thickness are varied. The upper part of Figures 6A and 6B shows printed materials with lines printed on them. The lower part of Figure 6A shows a graph with the horizontal direction of the printed materials in the upper part of Figures 6A and 6B on the horizontal axis and brightness on the vertical axis. As can be seen from the results shown in Figure 6A, which was printed with pigment ink, when the line spacing is 1 pixel, the line spacing is filled in by bleeding, and high brightness cannot be obtained. On the other hand, when the line spacing exceeds 7 pixels, high brightness can be obtained within the range of line spacing. Also, as shown in Figure 6B, which was printed with dye ink, with dye ink, when the line spacing exceeds 8 pixels, high brightness can be obtained within the range of line spacing. From these results, it can be seen that 7 pixels or more is preferable for pigment ink, and 8 pixels or more is preferable to reliably obtain high brightness for both dye and pigment inks.

[0039] Furthermore, if the line thickness E of the pattern becomes thin, the line detection accuracy decreases. Therefore, the line thickness E was set to be approximately the same as the line spacing D. This allows for accurate detection of both areas with and without lines.

[0040] Furthermore, if the line spacing D and line thickness E are set to 8 pixels, then in 600 dpi printing, the size (diameter) of the multi-circle pattern (double-circle pattern) will be 2.7 mm according to (Equation 1). For the triple-circle pattern, according to (Equation 2), the size (diameter) will be 4.1 mm according to (Equation 2). Note that the central white circle is assumed to have a radius of 8 pixels.

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[0041] Furthermore, the multi-circle pattern is printed in a single pass using nozzle rows of the same color. The multi-circle pattern in this embodiment is printed in pure black. For example, if printed in composite black, misalignment between nozzle rows may cause misalignment of the ejection position of each color ink during printing of the multi-circle pattern. In contrast, printing the multi-circle pattern using nozzle rows of the same color prevents such misalignment problems. Also, using black multi-circles increases the contrast with white, improving the accuracy of pattern matching.

[0042] Next, we will explain intermittent scanning. In intermittent scanning, the media may move, for example, if the user accidentally touches the media while the movement and illumination of the scanning unit 12 are temporarily paused. Here, media movement refers to a change in the position or inclination of the media relative to the glass surface 121. If pattern matching of the scanned image obtained after resumption is performed as if the media had not moved, even though the media has moved, the correct results cannot be obtained in pattern matching, and therefore the correct adjustment pattern cannot be set. In the following, such media movement will also be referred to as media misalignment.

[0043] Furthermore, when intermittent scanning is paused, the scanning unit 12 also stops illumination from the light source. If illumination from the light source is restarted when intermittent scanning resumes, the light intensity may not be stable, and the required light intensity may not be obtained. If the light intensity falls below the standard, reading cannot be continued. When performing intermittent scanning, the multifunction device 10 detects changes in the position and tilt of the media during pause and the light intensity from the light source, and makes a decision such as stopping the intermittent scanning based on the detection results. Hereinafter, the timing when the scanning is paused will be referred to as the pause time. Also, the timing immediately before the scanning unit 12 resumes movement in intermittent scanning, after the analysis such as pattern matching of the already scanned image has been completed, will be referred to as the restart time. Note that the restart time can be any timing after the pause time, after the scanned image stored in memory has been deleted, and before the timing when the scanning unit 12 resumes movement.

[0044] Next, the judgment pattern 330 of the test pattern 300 will be described. Here, the judgment pattern 330 is an example of an identification pattern for identifying media misalignment and changes in light intensity during pause and resume. In the test pattern 300, the judgment pattern 330 is positioned between the two adjustment patterns 310 in a direction corresponding to the sub-scanning direction of the printing unit 11. In the test pattern 300 shown in Figure 3, the adjustment pattern 310, judgment pattern 330, adjustment pattern 310, judgment pattern 330, and adjustment pattern 310 are arranged in that order along the direction corresponding to the sub-scanning direction of the scanning unit 12. Thus, in the test pattern 300, the judgment pattern 330 is positioned following the adjustment pattern 310 in the sub-scanning direction. The two adjustment patterns 310 flanking the judgment pattern 330 are an example of the first and second adjustment patterns.

[0045] The determination pattern 330 is a pattern in which multiple square basic patterns 331 are arranged in the sub-scanning direction. Each basic pattern 331 is arranged such that one pair of opposite sides is parallel to the main scanning direction. Furthermore, each basic pattern 331 includes a black triangle pattern 331a and a white triangle pattern 331b, with one diagonal as the boundary.

[0046] The stop state analysis unit 135 performs state analysis during pauses in intermittent scanning by using the test pattern 300, which includes the determination pattern 330. Specifically, the stop state analysis unit 135 determines whether the medium moved during the pause, and if the medium moved, it further identifies the amount of movement and the amount of tilt change of the medium. Figures 7 and 8 are diagrams illustrating the process of determining whether the medium has moved. In Figures 7 and 8, the medium on which the test pattern 300 is printed is rectangular in shape, and the length direction L and width direction W of the medium are defined. The length direction L of the medium corresponds to the transport direction of the medium when the test pattern 300 is printed on the medium (the sub-scanning direction of the printing unit 11). Also, for the sake of explanation, at the start of scanning, the medium is set so that its length direction L coincides with the sub-scanning direction of the scanning unit 12.

[0047] As shown in the upper part of Figure 7, assume that during intermittent scanning, the scanning unit 12 temporarily stops at a position corresponding to the line F1 on the medium. In the following, when the scanning unit 12 is positioned at a predetermined position on the medium, this will be referred to as the scanning unit 12 being positioned at a predetermined position on the medium.

[0048] During this pause, the media's position shifts parallel to the length L of the media, and intermittent scanning resumes with the media in this shifted position. In this case, as shown in the lower part of Figure 7, the relative positional relationship between the scanning unit 12 and the media changes. As a result, the scanning unit 12 will be positioned on a straight line F2 on the media when scanning resumes, for example. The line image G10 scanned when the scanning unit 12 is positioned on a straight line F1 will be different from the line image G20 scanned when the scanning unit 12 is positioned on a straight line F2.

[0049] Line image G10 contains five black areas G11, G12, G13, G14, and G15. White areas are also included between each black area. Similarly, line image G20 contains five black areas G21, G22, G23, G24, and G25, with white areas between each black area. However, the detection positions of line image G10 and line image G20 differ along the length L of the medium. Therefore, the width of each black area in line image G10 and line image G20 are different. Consequently, the movement of the medium in the sub-scanning direction can be detected by these changes in the width of the black areas. Note that the tilt of the medium does not change during movement in the sub-scanning direction, so the widths of each black area G21 to G25 in line image G20 are all equal.

[0050] Furthermore, by using a judgment pattern, changes in the tilt of the medium can also be detected. Suppose that after the scanning unit 12 stops at position F1 as shown in the upper part of Figure 8, the tilt of the medium changes, and the relative position of the scanning unit 12 to the medium becomes the position of the straight line F3 on the medium, as shown in the lower part of Figure 8. In this case, line image G30 is obtained when scanning is resumed. Line image G30 contains five black areas G31, G32, G33, G34, and G35, similar to line image G10.

[0051] Line images G10 and G30 have different slopes for the lines (F1 and F3) corresponding to their detection positions. Therefore, the width of the black area in line image G10 and the width of the black area in line image G30 are different. Furthermore, the width of each black area in line image G30 is due to the slope of line F3 relative to line F1, and the width gradually increases in the order of G31 to G35. In this way, based on the changes in the width of the black areas in line image G10 and line image G30, and the changes in the width of each black area in line image G30, it is possible to detect changes in the tilt of the medium during pause and resume.

[0052] The black pattern 331a has two sides (two straight lines) that are inclined with respect to the main scanning direction of the scanning unit 12, and the inclination angles of the two sides with respect to the main scanning direction are different. In this way, the determination pattern includes multiple lines with different inclination angles with respect to the main scanning direction, so the resulting linear detection pattern differs depending on the media displacement. Therefore, by using such a determination pattern, it becomes possible to detect changes in the position and tilt of the media.

[0053] Next, we will explain the process for determining the amount of movement and the change in tilt of the medium when it moves. As shown in Figure 8, when the medium moves in the sub-scanning direction, the amount of movement in the sub-scanning direction can be determined according to the change in the width of the black area. Also, when the medium moves in the main scanning direction, the amount of movement in the main scanning direction can be determined according to the change in the position of the black area.

[0054] Figure 9 is an explanatory diagram of the change in tilt amount θ of the medium when the medium is tilted. For the sake of explanation, Figure 9 shows a judgment pattern in which three basic patterns are arranged in a row. As shown in Figure 9, when paused, the width of the judgment pattern 3301 in the line image obtained on line F11 is W11, and when resumed, the width of the line image obtained on line F12 is W12. Also, the length of one side of the basic pattern 3302 of judgment pattern 330 is J, and the widths of the white area and black area of ​​the basic pattern 3302 obtained when resumed are M and N, respectively. Furthermore, the point in the upper right corner of the page of Figure 9 in the basic pattern 3302 is Q0. In addition, the intersection point of the boundary line between the black area and the white area of ​​the basic pattern 3302 and line F12 when stopped is Q10. The point that is at the same position as Q0 in the main scanning direction and at a different position from Q10 in the sub-scanning direction is Q11. The point that is at the same position as Q0 in the sub-scanning direction and at a different position from Q10 in the main scanning direction is Q12. In this case, the length between Q0 and Q11, and the length between Q0 and Q12, are both {N / (M+N)×J}. The change in slope θ is expressed by (Equation 3).

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[0055] Furthermore, the tilt of the medium can also be detected from the change in length corresponding to the width W1 of the judgment pattern shown in Figure 8. For example, in the case of a straight line F1, the length W1 is obtained, while in the case of a straight line F3, the length of the judgment pattern is longer than W1. In this way, when the length of the width of the judgment pattern changes, it can be determined that the tilt has changed. The tilt can also be identified from the amount of change in width. The length of the judgment pattern is obtained by detecting the ends of the judgment pattern in the width direction. In addition, parallel movement of the medium in the main scanning direction can be detected from the displacement of the edge corresponding to the width W1 in the length direction of the judgment pattern, and the amount of movement can be identified from the degree of that displacement. As described above, the stopped state analysis unit 135 determines whether or not the medium has moved, and further, if the medium has moved, it identifies the amount of movement and the amount of change in tilt.

[0056] Up to this point, the explanation has been based on the assumption that the length direction L of the medium coincides with the sub-scanning direction of the scanning unit 12 at the start of scanning. However, the length direction L of the medium does not necessarily have to coincide with the sub-scanning direction of the scanning unit 12. In this case, for example, the medium displacement (shift in the position or tilt of the medium) at the start of scanning can be identified by pattern matching using a position correction marker, and then, taking into account the initial medium displacement, the presence or absence of movement and the degree of medium displacement can be detected as described above.

[0057] The stop state analysis unit 135 first acquires a line image obtained by the scan unit 12 when the vehicle is temporarily stopped. Hereinafter, this line image will be referred to as the stop line image. The stop state analysis unit 135 also acquires a line image obtained by the scan unit 12 when the vehicle is restarted. Hereinafter, this line image will be referred to as the restart line image. In the above example, the line image obtained along straight line F1 corresponds to the stop line image, and the line images obtained along straight lines F2 and F3 correspond to the restart line images. Note that the stop line image and the restart line image are examples of stop images and restart images, respectively.

[0058] The stopped state analysis unit 135 further determines the boundary line of the judgment pattern and both ends of the black area by edge detection. The stopped state analysis unit 135 compares the positions of both ends of the black area obtained by edge detection at both the pause and resume states. The stopped state analysis unit 135 then determines that the edge positions are the same and the medium did not move if the sum of the changes in the corresponding edge positions (ends of the black area) is within a preset reference range. The stopped state analysis unit 135 determines that the medium has moved if the sum of the differences is outside the reference range. The stopped state analysis unit 135 also determines the width of the black area from the edge positions and identifies the degree of medium displacement (change in the movement and tilt of the medium) based on the change in width. As another example, the stopped state analysis unit 135 may also determine whether or not the medium has moved based on the width of each black area determined from the edge positions.

[0059] Furthermore, the scanning unit 12 is equipped with three line sensors corresponding to each of the RGB colors, but the line images when stopping and when resuming will be scanned using only one of the line sensors. In other words, the images when stopping and when resuming will be images of the color corresponding to the line sensor. This reduces the amount of computation required for detecting whether or not the medium has moved. The three line sensors correspond to a first line sensor that scans the first color, a second line sensor that scans the second color, and a third line sensor that scans the third color.

[0060] The stopped state analysis unit 135 further detects the light intensity of the light source when intermittent scanning is resumed. This process is described below. The stopped state analysis unit 135 creates a histogram in the line image at the time of resumption, with each brightness on the horizontal axis and the frequency of brightness on the vertical axis, and identifies the maximum brightness value. The stopped state analysis unit 135 then continues the intermittent scanning if the maximum value is within the range of continuity. During intermittent scanning, when movement is temporarily suspended, the illumination of light from the light source is also stopped. Therefore, when illumination of light from the light source is started at the time of resumption, the light intensity may not be stable. The continuity range is an evaluation value used to determine whether the light intensity is unstable or not. That is, the continuity range is the range of light intensity that allows for continued reading of the medium, and is set in advance. Note that the evaluation value used by the stopped state analysis unit 135 to determine whether the light intensity is within the continuity range can be any value determined based on each brightness in the line image at the time of resumption, and is not limited to the maximum brightness value.

[0061] Figure 10 is a flowchart illustrating the production method of the multifunction printer 10. Here, an unfinished multifunction printer 10 is one in which mechanical and electrical components have been assembled and it can perform printing operations, but it cannot print cleanly because it has not yet been adjusted. A finished multifunction printer 10 is one in which adjustments have been made and the adjustment pattern has been stored in non-volatile memory, allowing it to print cleanly. The flowchart in Figure 10 may be performed as part of the production process in a factory, or after the installation of an unfinished multifunction printer 10 at a customer's site.

[0062] First, the printing unit 11 of the unfinished multifunction printer 10 prints a test pattern 300 onto the medium under the control of the printing control unit 131 in response to user operation (step S100). Specifically, the printing unit 11 prints an adjustment pattern 310, a multi-circle pattern 220, and a judgment pattern 330 onto the medium. This produces a printed material in which the adjustment pattern, position correction pattern (multi-circle pattern), and judgment pattern are printed at predetermined relative positions. Next, the user sets (places) the medium on the glass surface 121 and performs user operation to start scanning. In response, the scan control unit 132 first moves the scan unit 12 to the home position in order to perform an intermittent scan of the medium on which the test pattern 300 has been printed (step S102). Next, the scan control unit 132 performs light intensity correction of the light source, i.e., shading correction (step S104). Specifically, the scan control unit 132 samples a white reference plate installed at the home position to generate white reference data for color correction, and then turns off the light source to sample a black reference and generate black reference data for color correction.

[0063] Next, when the user places the medium on which the test pattern 300 is printed onto the medium tray 122 and a scan command is input, the scan control unit 132 starts driving the scan unit 12 (step S106). This starts intermittent scanning of one medium to be scanned. Next, the adjustment pattern area is scanned (step S108). Here, the adjustment pattern area is the area on the medium that includes the adjustment pattern and the position correction pattern. The range of the sub-scanning direction of the scan unit 12 corresponding to the adjustment pattern is predetermined, and the scan unit 12 performs scanning within the predetermined range.

[0064] Next, the scan control unit 132 determines whether the area scanned in step S108 is the last adjustment pattern area (step S110). The last adjustment pattern area is the last adjustment pattern area to be scanned among the adjustment pattern areas contained in a single medium. In this embodiment, the multifunction device 10 is assumed to have a preset range for the sub-scanning direction of the last adjustment pattern area. The scan control unit 132 determines whether the area scanned in step S108 is the last adjustment pattern area based on whether the position of the scan unit 12 is within this range. If the area scanned in step S108 is not the last adjustment pattern area (N in step S110), the scan control unit 132 moves the scan unit 12 to the determination pattern area. Then, the scan control unit 132 temporarily stops the movement of the scan unit 12 and stops illumination by the light source on the determination pattern area (step S112). Here, the determination pattern area is the area containing the determination pattern. The position of the scan unit 12 in the sub-scanning direction corresponding to the determination pattern is predetermined, and the scan unit 12 moves to the predetermined position.

[0065] Next, the scan control unit 132 acquires a line image at the stop (step S114). Then, the detection unit 133 and the adjustment unit 134 perform image analysis of the scanned image of the adjustment pattern obtained in step S108 (step S116). Specifically, the detection unit 133 first detects four position correction patterns around the adjustment pattern. Then, the scan control unit 132 identifies the adjustment pattern region based on the position of the position correction patterns. As described in the first embodiment, the relative positional relationship between the adjustment pattern region and the position correction patterns is predetermined, and the adjustment pattern region is identified based on this positional relationship. Furthermore, as described above, the detection unit 133 adjusts the adjustment pattern distortion and tilt in the detected image of the scanned image based on the detection results of the four multi-circle patterns. Then, the adjustment unit 134 generates adjustment parameters for the printing unit 11 based on the pattern matching results of the adjustment pattern and stores them in the non-volatile memory 14. After that, the detection unit 133 deletes the scanned image recorded in the memory.

[0066] When the scan control unit 132 completes image analysis and deletes the scanned image from memory, it performs a scan again to acquire a line image at the time of restart (step S118). Next, the stopped state analysis unit 135 refers to the stopped line image and the restart line image to check whether the judgment pattern is included in either line image. Specifically, the stopped state analysis unit 135 determines that the judgment pattern is included if there is a repetition of white and black areas (step S120). If the judgment pattern is not included (N in step S120), the stopped state analysis unit 135 interrupts the paused intermittent scan and displays information indicating a sheet misalignment error on the display unit (step S130). This completes the process. In this case, for example, if the user performs an operation to restart after reinserting the media, the processor 13 will perform the process again from step S102 in accordance with the user operation.

[0067] On the other hand, if the stop state analysis unit 135 determines in step S120 that the determination pattern is included (Y in step S120), it proceeds to step S122. In step S122, the stop state analysis unit 135 compares the line image at the time of stop and the line image at the time of restart. Specifically, the stop state analysis unit 135 determines whether or not the medium has moved based on the sum of the change in edge positions of the line image at the time of stop and the line image at the time of restart, and a reference range.

[0068] If the medium does not move (N in step S122), the stopped state analysis unit 135 proceeds to step S128. If the medium does move (Y in step S122), the stopped state analysis unit 135 determines whether the amount of movement can be corrected (step S124). Specifically, the stopped state analysis unit 135 identifies the amount of movement and the amount of tilt change, and determines whether correction is possible by comparing the amount of movement with the amount of movement threshold and the amount of tilt change with the amount of tilt change threshold. Here, the amount of movement threshold and the amount of tilt change threshold are values ​​that are predetermined and whose position corresponds to the range of tilt deviation when the entire medium is included within the readable range of the glass surface 121.

[0069] The stopped state analysis unit 135, if correction is possible (Y in step S124), determines the amount of movement and tilt change of the medium, and updates the medium's position information based on these values ​​(step S126). Based on the corrected medium's position information, the positions of images scanned thereafter are updated. Here, the medium's position information is information indicating the relative position of the medium with respect to the scan unit 12, and is used when analyzing the adjustment pattern. For example, suppose that at the start of scanning, the medium is placed along the main scanning direction with a predetermined corner of the glass surface 121 as the reference. In this case, the medium's position information shows the predetermined position of the scan unit 12 as the medium reference position, and the main scanning direction and sub-scanning direction as the width direction and length direction of the medium, respectively. When the medium moves, the medium reference position and the orientation of the medium (width direction and length direction) are updated according to the amount of positional displacement and tilt change.

[0070] Next, the stop state analysis unit 135 determines whether the change in light intensity of the scan unit 12 is within a sustainable range based on the line image at the time of stop and the line image at the time of restart. If the change in light intensity is within a sustainable range (Y in step S128), the scan control unit 132 proceeds to step S106. In this case, the scan control unit 132 restarts the intermittent scan by the scan unit 12 at the stop position.

[0071] Furthermore, if the light intensity change is outside the sustainable range (N in step S128), the scan control unit 132 proceeds to step S102. That is, the scan control unit 132 moves the scan unit 12 to the home position, performs light intensity correction again, and then performs intermittent scanning on the subsequent adjustment pattern region.

[0072] Thus, if the medium is not moving and the change in light intensity is within a sustainable range, the scan control unit 132 resumes intermittent scanning from the paused position. Furthermore, even if the medium has moved, if correction is possible, the scan control unit 132 performs the correction and then resumes intermittent scanning from the paused position. On the other hand, if the medium has moved and correction is not possible, the scan control unit 132 interrupts the intermittent scanning that was paused.

[0073] In step S110, if it is the last adjustment pattern region on the medium to be processed (Y in step S110), the detection unit 133 and the adjustment unit 134 perform image analysis of the scanned adjustment pattern (step S140). Specifically, the detection unit 133 performs pattern matching of the adjustment pattern, and the adjustment unit 134 generates adjustment parameters for the printing unit 11 based on the matching result and stores them in non-volatile memory. With this, the adjustment of the multifunction printer 10 is performed, and the production of the completed multifunction printer 10 is completed.

[0074] As described above, in the multifunction printer 10 of this embodiment, if the media does not move during a pause in intermittent scanning, the intermittent scanning continues. On the other hand, if the media moves, the intermittent scanning is interrupted. This ensures that even if the media moves, the size, position, and inclination of the test pattern are correctly identified. Furthermore, even if the media moves, pattern matching of the scanned image is not performed as if it were not moving, allowing for correct pattern matching. In addition, even if the edges of the media cannot be detected, the movement of the media can be detected. Moreover, by utilizing a multi-circle pattern, it is possible to produce a multifunction printer 10 with a highly accurate print adjustment section. Furthermore, in image analysis of the scanned image of the adjustment pattern printed on the media, the size, position, and inclination of the adjustment pattern can be correctly identified.

[0075] Figures 11A and 11B show a first modified example of this embodiment. In this first modified example, the multi-circle pattern is not limited to double circles, but can be any pattern composed of multiple circles. For example, as shown in Figure 11A, the multi-circle pattern may be a pattern showing three circumferences with equal centers but different radii, i.e., a triple-circle pattern 221. Another example is a pattern 222 that includes filled concentric circles, as shown in Figure 11B. Even when a filled circle is included, the number of edges can be increased by adding lines indicating the circumference outside it. Therefore, even if nozzle clogs occur, their center position can be identified with high precision. Thus, the multi-circle pattern can be any pattern showing multiple circumferences with different radii, and the specific number of circumferences, etc., is not limited to this embodiment. Furthermore, the center of the multi-circle may or may not include a filled circle.

[0076] Furthermore, as a second variation, the number and size of the circumferences, the width of the lines, and the spacing of the lines in the multi-circle pattern are not limited to the embodiment. For example, in cases where a large size of the multi-circle pattern does not pose a problem, the width and spacing of the lines may be wider.

[0077] Furthermore, as a third variation, the multi-circle pattern only needs to be formed with a single color of ink and is not limited to black. The multifunction printer 10 may have multiple print heads 111 for each nozzle row of each color. In this case, the multi-circle pattern is printed by the nozzle row corresponding to one color of ink provided in one print head 111.

[0078] A fourth variation is that the printing unit 11 can perform printing using ink, and the method is not limited to an inkjet method. Another example is that the printing unit 11 may perform printing using a sublimation transfer method. Yet another example is that the printing unit 11 may perform printing using a laser method.

[0079] As a fifth variation, the multifunction printer 10 may produce printed material on which a multi-circle pattern is printed along with the identification pattern that is the target of pattern recognition. Examples of such printed material include mark sheets. A multi-circle pattern whose relative positional relationship with the pattern indicating the mark position as the identification pattern is known may be printed on the medium used as a mark sheet. Furthermore, there is no limit to the number of multi-circle patterns printed on the printed material. For example, if the position of a certain point on the printed material is to be identified, it is sufficient to print a multi-circle pattern at that point. Also, if a predetermined direction on the medium is to be identified, it is sufficient to print a multi-circle pattern at two points on a straight line whose angle with the direction to be identified is known. Also, if a predetermined rectangular area on the medium is to be identified, it is sufficient to print a multi-circle pattern at least three points. The three points shall be arranged at the three vertices of the rectangular area.

[0080] As a sixth variation, the multifunction printer 10 may be equipped with a print head 111 capable of using both pigment ink and dye ink. In this case, the print head 111 will print the multi-circle pattern using only pigment ink. It is known that dye ink bleeds more than pigment ink. Figures 6A and 6B also show that printing the multi-circle pattern using pigment ink allows for more accurate detection. Therefore, when it is possible to use both pigment ink and dye ink, it is desirable to use pigment ink.

[0081] A seventh modification will now be described. In the embodiment, a method for producing the multifunction printer 10 was described by setting an adjustment pattern for the print head 111 of the unfinished multifunction printer 10. However, the setting of the adjustment pattern by printing a test pattern, generating a scanned image of the test pattern, and analyzing the scanned image, which are performed in the multifunction printer 10, may be performed at a time other than during production. The setting of the adjustment pattern may be performed, for example, during maintenance of the multifunction printer 10.

[0082] The eighth modification will now be described. The equipment to be produced can be any device equipped with a printing unit, and is not limited to a multifunction printer. The equipment to be produced may also be a printing device. Furthermore, if the equipment to be produced is a printing device, the printing device only needs to print the test pattern and set the generated adjustment pattern, and all other processing will be performed by a scanning device (scanner), which is a separate device from the printing device. That is, the scanning device generates a scanned image from the medium on which the test pattern is printed, generates an adjustment pattern, and transmits it to the printing device. In this case, the scanning device is assumed to have the information of the printing device necessary for generating the adjustment pattern stored in advance. Another example is that the scanning device only generates the scanned image, and the process of generating the adjustment pattern from the scanned image is performed by the printing device to be produced.

[0083] Another example is that the scanning device only generates the scanned image, and the process of generating the adjustment pattern from the scanned image is performed by an adjustment device, which is a different device from the scanning and printing devices. In this case, the scanned image is transmitted from the scanning device to the adjustment device, and the adjustment parameters are transmitted from the adjustment device to the printing device.

[0084] Figures 12A to 12D show the ninth modified example. The determination pattern can include multiple lines that are inclined with respect to the main scanning direction and have different angles of inclination with respect to the main scanning direction. The determination pattern 341 shown in Figure 12A includes black triangles whose vertices are located at positions other than the vertices of a square. The determination pattern 342 shown in Figure 12B includes a trapezoid. The determination pattern 343 shown in Figure 12C includes a quarter circle. Thus, the lines (boundaries) are not limited to straight lines but may also be curves. Furthermore, the determination pattern 344 shown in Figure 12D includes lines of multiple triangles with the same centroid. In this way, increasing the number of lines allows for more accurate identification of the presence or absence and degree of movement of the medium.

[0085] Furthermore, the detection pattern only needs to be such that the length of the detection range of the pattern changes when the tilt of the medium changes, and the scanned pattern changes when the medium moves. Therefore, it does not need to be a repetition of the reference pattern. Also, although the detection pattern is defined as including a black area and a white area, it only needs to include the area where ink is ejected and the area where ink is not ejected (white area), and the ink color is not limited to black.

[0086] As a tenth variation, the scan control unit 132 may pause, and if it determines that the medium has moved, it may resume intermittent scanning and continue intermittent scanning if a position correction pattern is detected in the subsequent adjustment pattern area. In this case, the position information indicating the relative position of the medium to the reading position of the scan unit should be updated based on the position of the detected correction position pattern. Alternatively, if no position correction pattern is detected in the subsequent adjustment pattern area, the scan control unit 132 may interrupt intermittent scanning at that point.

[0087] Furthermore, as an eleventh modification, when scanning multiple media consecutively, the system pauses at a position corresponding to the determination pattern after the scan of one medium is completed. The pause state analysis unit 135 may then determine whether the medium has been changed to a new medium based on the line image at the time of pause and the line image at the time of restart. Specifically, the pause state analysis unit 135 acquires the line image at the time of pause. After that, the user changes the medium to a new medium and then performs an operation for rescanning. The scan control unit 132 performs a scan at the pause position in response to the user operation. The pause state analysis unit 135 then acquires a line image (line image at the time of restart). The pause state analysis unit 135 determines that the medium has been changed to a new medium if the amount of change in edge position in the line image at the time of pause and the line image at the time of restart is greater than or equal to an acceptable range. If the amount of change in edge position is less than an acceptable range, the unit determines that the user performed an operation for rescanning without changing the medium and prompts the user to change the medium.

[0088] Here, the tolerance range is a predetermined range. The tolerance range is wider than the reference range used to determine whether or not the medium has moved. In other words, the tolerance range includes a larger amount of edge position change than the reference range.

[0089] Furthermore, as a twelfth variation, the scanning unit 12 does not have to be a line sensor. That is, the scanning unit 12 may scan one line in the width direction of the medium while moving in the main scanning direction.

[0090] A thirteenth modification will be described. In this embodiment, a method for producing the multifunction printer 10 was described by setting the adjustment parameters of the print head 111 of the unfinished multifunction printer 10. However, the setting of adjustment parameters by printing a test pattern, generating a scanned image of the test pattern, and analyzing the scanned image, which are performed in the multifunction printer 10, may be performed at a time other than during production. The setting of adjustment parameters may be performed, for example, during maintenance of the multifunction printer 10.

[0091] The embodiments described above are merely examples for carrying out the present invention, and various other embodiments can be adopted. For example, various modifications and changes are possible within the scope of the gist of the present invention as described in the claims, such as applying a variation of one embodiment to another embodiment.

[0092] Alternatively, the search for multiple circle patterns may be performed on the entire scanned image. In particular, the first time, the search for multiple circle patterns is performed on a comparison region set based on the top-left vertex 211, but if no pattern is found, the search for multiple circle patterns may be performed on the entire scanned image.

[0093] Alternatively, the entire media can be scanned in one go without performing intermittent scans. Intermittent scans are recommended, especially if there is little free memory due to other processes, but they can be avoided when there is plenty of free memory and no other processes are running.

[0094] Using a judgment pattern to detect media movement during intermittent scanning may be performed when scanning media that does not have an adjustment pattern printed on it.

[0095] Alternatively, after storing the adjustment parameters in non-volatile memory, another process that does not affect print quality may be performed to complete the process.

[0096] Furthermore, the present invention is also applicable as a program or method executed by a computer. It can also be implemented as a single device, or by utilizing components from multiple devices, encompassing various embodiments. Moreover, it can be modified as appropriate, such as being partly software and partly hardware. Furthermore, the invention also functions as a recording medium for a program that controls a system. Of course, this recording medium could be a magnetic recording medium, a semiconductor memory, or any recording medium developed in the future; the same principle applies. [Explanation of Symbols]

[0097] 10...Multifunction printer, 11...Printing unit, 12...Scanning unit, 13...Processor, 131...Printing control unit, 132...Scanning control unit, 133...Detection unit, 134...Adjustment unit, 135...Stopped state analysis unit

Claims

1. A method for producing a printing apparatus that produces a modified printing apparatus from a printing apparatus before modification, The printing section of the printing apparatus before adjustment is made to print a multi-circle pattern showing at least three concentric circles and an adjustment pattern at predetermined relative positions on the medium. The printed medium is placed in the scanning unit. The printed medium is scanned to generate a scanned image. The multiple circle pattern is detected from the scanned image. Based on the relative position and the detection position of the multi-circle pattern, the adjustment pattern is detected. Based on the detection results of the aforementioned adjustment pattern, the adjustment parameters are calculated. The adjustment parameters are stored in the non-volatile memory of the printing device before adjustment. The aforementioned multi-circle pattern is, Two circles with equal centers and different radii are printed on the circumference. A printing apparatus production method for a pattern, wherein a non-printing area is interposed between a first circle and a second circle different from the first circle.

2. The printing apparatus production method according to claim 1, wherein the spacing between adjacent circles in the multi-circle pattern is 7 pixels or more.

3. The printing apparatus production method according to claim 2, wherein the spacing between adjacent circles in the multi-circle pattern is 8 pixels or more.

4. The printing apparatus production method according to claim 2 or 3, wherein the line thickness of the circles included in the multi-circle pattern is 7 pixels or more.

5. The printing apparatus production method according to claim 4, wherein the line thickness of the circles included in the multi-circle pattern is 8 pixels or more.

6. The printing apparatus production method according to any one of claims 1 to 5, wherein the multi-circle pattern includes a filled circle at its center.

7. The printing apparatus production method according to any one of claims 1 to 6, wherein the printing unit performs printing using an inkjet method.

8. The printing apparatus production method according to claim 7, wherein, if the printing unit is capable of printing using both pigment ink and dye ink, the multi-circle pattern is printed using only the pigment ink.

9. A printing apparatus production method according to any one of claims 1 to 8, wherein the multiple circle pattern is detected by pattern matching of the scanned image and the image of the multiple circle pattern.

10. The aforementioned printing unit is The print head has a nozzle row in which the nozzles are arranged in the sub-scanning direction, The printing apparatus production method according to any one of claims 1 to 9, wherein the multi-circle pattern is printed in one pass by a row of nozzles of the same color contained in one of the print heads.

11. An adjustment device for adjusting the printing section of a printing device, A detection unit detects the multi-circle pattern, which shows at least three concentric circles, and an adjustment pattern used for adjusting the printing unit, in a scanned image generated by scanning a medium printed at a predetermined relative position by the printing unit, and detects the adjustment pattern based on the relative position and the detection position of the multi-circle pattern. The system includes an adjustment unit that stores the adjustment parameters of the printing unit in a non-volatile memory based on the detection results of the adjustment pattern, The aforementioned multi-circle pattern is, Two circles with equal centers and different radii are printed on the circumference. A pattern adjustment device in which a non-printed area is interposed between a first circle and a second circle different from the first circle.

12. An adjustment program for adjusting the printing unit of a printing device, Computers A pattern detection unit detects the multi-circle pattern, which includes at least a triple-circle pattern, and an adjustment pattern used for adjusting the printing unit, in a scanned image generated by scanning a medium printed at a predetermined relative position by the printing unit, and detects the adjustment pattern based on the detection position of the multi-circle pattern and the relative position, and The adjustment unit functions as one that stores the adjustment parameters of the printing unit in a non-volatile memory based on the detection results of the adjustment pattern. The aforementioned multi-circle pattern is, Two circles with equal centers and different radii are printed on the circumference. An adjustment program that is a pattern, in which a non-printable area is interposed between a first circle and a second circle that is different from the first circle.

Images