Sheet processing position correction method and sheet processing device

Abstract

A first mark (MA) which is provided to a sheet (10) includes a first line (A1), a second line (A2), and a third line (A3). A first detection point (P1) on the first line (A1) and a third detection point (P3) on the third line (A3) are detected by a single first scan in the CR direction. A second detection point (P2) on the second line (A2) and a fourth detection point (P4) which, on the third line (A3), is at a position differing from that of the third detection point (P3) are detected by a single second scan in the PF direction. A first reference point (CA) that is an intersection of the first line (A1) and the second line (A2) and the inclination of the sheet (10) are computed on the basis of the coordinates of these four points and the shape data of the first mark (MA). A cut position for cutting a cut region (40) on the sheet (10) is corrected on the basis of the result of the computation. A first detection start point (NA) is determined by a preliminary scan in the CR direction so as to avoid excessive proximity between the third detection point (P3) and the fourth detection point (P4).

Description

Sheet processing position correcting method and sheet processing apparatus

[0001] The present invention relates to a sheet processing position correcting method and a sheet processing apparatus.

[0002] A sheet with a sealing material such as an adhesive film attached to a backing such as release paper is placed in a printer, and an image or text is printed on the sheet. The sheet is then cut along the contours of the printed area (cut area) to create a sticker. If the cutting device for cutting the sheet is integrated with the printer, the sheet can be cut without being removed after printing. Alternatively, the printed sheet can be set in a cutting device separate from the printer and cut. The timing for cutting the sheet may be before printing on the sheet, or after printing on the sheet. Alternatively, the sheet may be cut after printing once and before overprinting.

[0003] Cutting devices used for this type of application cut the sheet by moving the sheet relative to the cutter, for example, by combining the operation of scanning the cutter in the sheet width direction with the operation of transporting the sheet in a direction intersecting the cutter scanning direction. However, if the sheet is set in the cutting device at an angle or in a position shifted from the reference position, the sheet will be cut along a line that is shifted from the contour to be cut. Therefore, before starting cutting, the cutting device uses a sensor to detect a cutting position reference mark printed on the sheet, and based on the detection result, performs a correction (cut position correction) to align the cutter movement trajectory with the contour line of the cutting area.

[0004] For rectangular or long sheets, the cutting position reference mark is generally an L-shaped or cross-shaped mark (so-called registration mark) in which a horizontal line extending in the sheet width direction and a vertical line extending in the sheet length direction intersect. Patent Document 1 describes a cutting method and cutting device (cutting plotter) that reads this type of mark and corrects the cutting position.

[0005] In the cutting method of Patent Document 1, at least two marks are read to correct the cutting position. Specifically, for each of the two marks (register mark 1 and register mark 2) attached to the left and right side edges of the sheet, a scan is performed once in a direction intersecting the horizontal line of the mark and once in a direction intersecting the vertical line of the mark. These four scans determine the coordinates of one point on the horizontal line and one point on the vertical line of each of the two marks. Once the coordinates of these four points are determined, the sheet inclination and the coordinate origin on the sheet can be calculated, assuming that the shapes and positions of the two marks on the sheet are known. The position and inclination of the cutting area can then be determined from the sheet inclination and the coordinate origin on the sheet.

[0006] Patent No. 3589441

[0007] In Patent Document 1, in order to determine the position and inclination of the cutting area required for cutting position correction, two marks located at a distance must each be scanned twice, which results in a large number of scans and movement between the marks, requiring many operations and a long time.

[0008] The above problem is related to correcting the cutting position when cutting a sheet, but when printing on a sheet, the sheet may be set in a position that is displaced from the reference position or tilted from the reference position, making it necessary to correct the print position. In such cases, the print position can be corrected using a similar mark as a position reference, but the same problem occurs.

[0009] In view of the above, an object of the present invention is to easily obtain the sheet inclination and the coordinate origin on the sheet, which are required for correcting the sheet processing position, such as cutting position correction or printing position correction.

[0010] In order to solve the above-mentioned problems, the present invention provides a sheet processing position correction method for detecting a first mark indicating a processing area of ​​a sheet by a sensor and correcting a processing position when performing at least one of printing and cutting on the processing area, wherein the first mark includes a first line, a second line, and a third line that extend in different directions from each other and do not intersect at the same point, and a first scan is performed in which the sensor is moved relatively to the sheet in a first scanning direction, and a first detection point is determined as an intersection point between the scanning line of the first scan and the first line, and a third detection point is determined as an intersection point between the scanning line of the first scan and the third line. a second scan is performed in which the sensor is moved relative to the sheet in a second scan direction intersecting the first scan direction, and a second detection point is detected which is an intersection of a scan line of the second scan and the second line, and a fourth detection point which is an intersection of the scan line of the second scan and the third line and is different from the third detection point; a first reference point which indicates the position of the first mark and an inclination of the sheet are calculated based on first shape data which indicates the shape of the first mark and the coordinates of the first detection point, the second detection point, the third detection point, and the fourth detection point; and the processing position is corrected based on the calculation result.

[0011] Furthermore, in order to solve the above-mentioned problems, the present invention provides a sheet processing apparatus having at least one of a cutter for cutting a sheet and a print head for printing on the sheet, a sensor for detecting a first mark indicating a processing area of ​​the sheet, a first scanning mechanism for moving the sensor relatively to the sheet in a first scanning direction, a second scanning mechanism for moving the sensor relatively to the sheet in a second scanning direction intersecting the first scanning direction, and a control unit that controls the first scanning mechanism and the second scanning mechanism and receives a detection signal from the sensor, wherein the first mark includes a first line, a second line, and a third line that extend in directions intersecting each other but do not intersect at the same point, and the control unit performs a first scan that drives the first scanning mechanism to move the sensor relatively to the sheet in the first scanning direction, and a second scan that drives the second scanning mechanism to move the sensor relatively to the sheet in the second scanning direction. and a mark detection unit that performs a second scan by moving the sheet relative to the first line, and detects, from the output of the sensor in the first scan, a first detection point which is an intersection of the scanning line of the first scan and the first line, and a third detection point which is an intersection of the scanning line of the first scan and the third line, from the output of the sensor in the second scan, and detects, from the output of the sensor in the second scan, a second detection point which is an intersection of the scanning line of the second scan and the second line, and a fourth detection point which is an intersection of the scanning line of the second scan and the third line and is different from the third detection point, and a sheet processing position correction unit that calculates a first reference point which indicates the position of the first mark and a tilt of the sheet based on first shape data which indicates the shape of the first mark and the coordinates of the first detection point, the second detection point, the third detection point, and the fourth detection point, and corrects a processing position when performing at least one of printing and cutting on the processing area based on the calculation result.

[0012] According to the sheet processing position correction method and sheet processing apparatus of the present invention, the coordinates of the first reference point indicating the position of the first mark and the sheet inclination can be obtained simply by scanning the first mark twice. Once the coordinates of the first reference point are obtained, the coordinate origin can be obtained, assuming that the relative position of the coordinate origin on the sheet with respect to the first reference point is known, and the cutting position can be corrected based on the coordinate origin. Therefore, since it is only necessary to scan at least one mark to correct the sheet processing position and the number of scans per mark is small, the sheet inclination and the coordinate origin on the sheet required for correcting the sheet processing position can be easily obtained.

[0013] In the sheet processing position correction method of the present invention, before performing the first scan and the second scan, a preliminary scan is performed in which the sensor is moved relative to the sheet in the first scan direction, and a first detection start point is determined based on the detection results of the first line and the third line by the preliminary scan and the first shape data, and the first scan and the second scan are each performed along a scanning line that passes through the first detection start point, and when determining the first detection start point, it is preferable to determine it so that the distance between the third detection point and the fourth detection point is equal to or greater than a predetermined distance.

[0014] In addition, in the sheet processing apparatus of the present invention, it is preferable that the mark detection unit performs a preliminary scan by driving the first scanning mechanism to move the sensor in the first scanning direction, and is provided with a detection start point determination unit that determines a first detection start point based on the detection results of the first line and the third line by the preliminary scan and the first shape data, and that the mark detection unit performs each of the first scan and the second scan along a scanning line that passes through the first detection start point, and that the detection start point determination unit determines the first detection start point so that the distance between the third detection point and the fourth detection point is equal to or greater than a predetermined distance.

[0015] In this way, the scanning position can be set so that the distance between the two detection points on the third line is not too small. If the distance between the two points is not too small, the inclination of the third line can be determined with high accuracy. Therefore, the inclination of the sheet and the origin position can be determined with high accuracy. In this way, if the positions of the detection points can be brought closer to the ideal positions by the preliminary scan, the inclination of the sheet and the origin position can be determined with high accuracy even without using a high-precision sensor.

[0016] In the sheet processing position correction method of the present invention, it is preferable that, before performing the first scan and the second scan, a preliminary scan is performed in which the sensor is moved relative to the sheet in the first scan direction, a detection start point for the first scan is determined based on the detection results of the first line and the third line by the preliminary scan and the first shape data, the first scan is performed along a scanning line passing through the detection start point for the first scan, a detection start point for the second scan is determined based on the first detection point or the third detection point detected by the first scan, the second scan is performed along a scanning line passing through the detection start point for the second scan, and when determining the detection start point for the second scan, the distance between the third detection point and the fourth detection point is determined to be equal to or greater than a predetermined distance.

[0017] In addition, in the sheet processing apparatus of the present invention, it is preferable that the control unit drives the first scanning mechanism to perform a preliminary scan to move the sensor in the first scanning direction, and is provided with a detection start point determination unit that determines a detection start point for the first scan based on the detection results of the first line and the third line by the preliminary scan and the first shape data, the mark detection unit performs the first scan along a scanning line that passes through the detection start point for the first scan, the detection start point determination unit determines a detection start point for the second scan based on the first detection point or the third detection point detected by the first scan, the mark detection unit performs the second scan along a scanning line that passes through the detection start point for the second scan, and when determining the detection start point for the first scan and the detection start point for the second scan, the detection start point determination unit determines them so that the distance between the third detection point and the fourth detection point is equal to or greater than a predetermined distance.

[0018] In this way, the scanning position can be set so that the distance between two points on the third line is not too small. If the distance between the two points is not too small, the inclination of the third line can be determined with high accuracy. Therefore, the inclination of the sheet and the origin position can be determined with high accuracy. In particular, since the scanning line for the second scan is determined using the results of the first scan, the detection start point for the second scan can be brought closer to the ideal position. Therefore, even if a high-precision sensor is not used, the inclination of the sheet and the origin position can be determined with high accuracy.

[0019] In the sheet processing position correction method of the present invention, it is preferable to check whether the distance between the first detection point and the third detection point detected by the first scan is within a predetermined tolerance range, and if the distance is outside the tolerance range, to move the detection starting point for the first scan in the second scan direction and perform the first scan again.

[0020] In addition, in the sheet processing apparatus of the present invention, it is preferable that the detection start point determination unit checks whether the distance between the first detection point and the third detection point detected by the first scan is within a predetermined tolerance range, and if the distance is outside the tolerance range, moves the detection start point for the first scan in the second scan direction, and the mark detection unit performs the first scan again along a scan line that passes through the detection start point for the first scan after the movement.

[0021] In this way, if the detection start point for the first scan deviates significantly from its ideal position, this fact can be detected and the position of the detection start point for the first scan can be corrected, thereby bringing the position of the detection point obtained by the first scan closer to its ideal position and preventing the distance between two points on the third line from becoming too small.

[0022] In the sheet processing position correction method of the present invention, it is preferable that the speed at which the sensor is moved relative to the sheet during the preliminary scan is faster than the speed at which the sensor is moved relative to the sheet during the first scan and the second scan.

[0023] In addition, in the sheet processing apparatus of the present invention, it is preferable that the detection start point determination unit moves the sensor relative to the sheet during the preliminary scan at a speed faster than the speed at which the sensor moves relative to the sheet during the first scan and the second scan.

[0024] This shortens the time required for the pre-scanning, thereby shortening the time required for mark detection. Furthermore, because the pre-scanning only needs to determine the detection start point, even if the detection accuracy decreases due to high-speed scanning, the effect on the detection accuracy of the first, second, third, and fourth detection points is minimal. Therefore, the effect on the detection accuracy of the sheet tilt and the coordinate origin is minimal.

[0025] In the sheet processing position correction method of the present invention, based on the detection signal of the sensor in the first scan, the distance between two points indicating one edge and the other edge in the first scan direction is detected as the line width for each of the first line and the third line, and if the ratio between the line width of the first line and the line width of the third line is outside a predetermined reference range, it is preferable to stop detecting the first mark without performing the second scan.

[0026] In addition, in the sheet processing device of the present invention, it is preferable that the mark detection unit calculates the distance between two points indicating one edge and the other edge in the first scanning direction as the line width for each of the first line and the third line based on the detection signal of the sensor in the first scan, and if the ratio between the line width of the first line and the line width of the third line is outside a predetermined reference range, it stops detecting the first mark without performing the second scan.

[0027] In the present invention, a first mark including three lines with different inclinations is used, and therefore the line width ratio changes according to the inclination of the first mark. If the inclination of the mark is too large, even if the first and second scans are performed, the deviation of the detection point from the ideal position may be too great, making it difficult to accurately calculate the sheet inclination and the coordinate origin. Therefore, by halting detection of the first mark based on the line width ratio, it is possible to avoid low-accuracy mark detection and, as a result, low-accuracy cutting position correction.

[0028] In the sheet processing position correction method of the present invention, it is preferable that the first detection point is the center point of a straight line connecting two points indicating one edge and the other edge in the first scanning direction on the first line detected by the sensor, the second detection point is the center point of a straight line connecting two points indicating one edge and the other edge in the second scanning direction on the second line detected by the sensor, the third detection point is the center point of a straight line connecting two points indicating one edge and the other edge in the first scanning direction on the third line detected by the sensor, and the fourth detection point is the center point of a straight line connecting two points indicating one edge and the other edge in the second scanning direction on the third line detected by the sensor.

[0029] Furthermore, in the sheet processing device of the present invention, it is preferable that the mark detection unit calculates, as the first detection point, the center point of a straight line connecting two points indicating one edge and the other edge in the first scanning direction on the first line detected by the sensor, as the second detection point, the center point of a straight line connecting two points indicating one edge and the other edge in the second scanning direction on the second line detected by the sensor, as the third detection point, the center point of a straight line connecting two points indicating one edge and the other edge in the first scanning direction on the third line detected by the sensor, and as the fourth detection point, the center point of a straight line connecting two points indicating one edge and the other edge in the second scanning direction on the third line detected by the sensor.

[0030] In this way, points on the center lines of the lines that make up the mark can be detected as detection points, so that the inclination of the mark and the first reference point can be detected with high precision.

[0031] In the sheet processing position correcting method of the present invention, it is preferable that the first mark is a right-angled triangle, and the first line and the second line are orthogonal to each other. In this case, it is preferable that the second scanning direction is a conveying direction of the sheet, the sheet is conveyed in the conveying direction when the second scanning is performed, the first scanning direction is a direction orthogonal to the conveying direction, the sensor is moved relative to the sheet in the direction orthogonal to the conveying direction when the first scanning is performed, and when the sheet is not tilted, the first line is parallel to the conveying direction, the second line is orthogonal to the conveying direction, and the third line is inclined at 45° with respect to the conveying direction.

[0032] In the sheet processing apparatus of the present invention, it is preferable that the second scanning mechanism is a transport mechanism that transports the sheet, the second scanning direction is a transport direction of the sheet, and the first scanning direction is perpendicular to the transport direction. Furthermore, it is preferable that the first mark is a right triangle, and when the sheet is not tilted, the first line is parallel to the transport direction, the second line is perpendicular to the transport direction, and the third line is inclined at 45 degrees with respect to the transport direction.

[0033] In this way, scanning in two directions can be performed using a sheet transport mechanism and a scanning mechanism that scans in a direction perpendicular to the transport direction. Furthermore, by detecting two points on the third line, which is the oblique side, the inclination of the oblique side can be determined with high accuracy. Therefore, the inclination of the sheet can be determined easily and with high accuracy.

[0034] In the sheet processing position correcting method and the sheet processing apparatus of the present invention, it is preferable that the first reference point is determined as an intersection point between the first line and the second line. In this way, the first reference point can be easily determined.

[0035] In the sheet processing position correcting method of the present invention, when a second mark indicating the processing area is affixed to the sheet, and the second mark includes fifth, sixth, and seventh lines that extend in different directions from one another and do not intersect at the same point, a second detection start point is determined based on the first reference point, second shape data indicating the shape of the second mark, and data on the relative position of the second mark with respect to the first mark, a third scan is performed in which the sensor is moved relatively to the sheet in the first scanning direction, a fifth detection point which is an intersection point between the scanning line of the third scan and the fifth line, and a seventh detection point which is an intersection point between the scanning line of the third scan and the seventh line, and the sensor is moved relative to the sheet. a fourth scan is performed by moving the sheet relatively in the second scanning direction, and a sixth detection point is detected as an intersection point of a scanning line of the fourth scan and the sixth line, and an eighth detection point is detected as an intersection point of a scanning line of the fourth scan and the seventh line, the eighth detection point being different from the seventh detection point; of the third scan and the fourth scan, at least the third scan is performed along a scanning line that passes through the second detection start point; a second reference point indicating the position of the second mark is calculated based on the second shape data and coordinates of the fifth detection point, the sixth detection point, the seventh detection point, and the eighth detection point; an inclination of the sheet is calculated based on the first reference point and the second reference point; and the processing position is corrected based on the calculation result.

[0036] In the sheet processing apparatus of the present invention, when a second mark indicating the processing area is affixed to the sheet, and the second mark includes a fifth line, a sixth line, and a seventh line that extend in different directions from one another and do not intersect at the same point, the detection start point determination unit determines a second detection start point based on the first reference point, second shape data indicating the shape of the second mark, and data on the relative position of the second mark with respect to the first mark, and the mark detection unit performs a third scan in which the sensor is moved relatively to the sheet in the first scanning direction, and detects a fifth detection point that is an intersection point between the scanning line of the third scan and the fifth line, and a seventh detection point that is an intersection point between the scanning line of the third scan and the seventh line, and further a fourth scan is performed to move the sheet relative to the sheet in the second scanning direction, and a sixth detection point is detected as an intersection of a scanning line of the fourth scan and the sixth line, and an eighth detection point is detected as an intersection of the scanning line of the fourth scan and the seventh line, the eighth detection point being different from the seventh detection point; of the third scan and the fourth scan, at least the third scan is performed along a scanning line that passes through the second detection start point; and it is preferable that the sheet processing position correction unit calculates a second reference point indicating the position of the second mark based on the second shape data and coordinates of the fifth detection point, the sixth detection point, the seventh detection point, and the eighth detection point, calculates the inclination of the sheet based on the first reference point and the second reference point, and corrects the processing position based on the calculation result.

[0037] In this way, the detection start point of the second mark is determined using the detection result of the first mark, so the detection start point of the second mark can be brought closer to its ideal position. This brings the seventh and eighth points closer to their ideal positions, preventing the distance between the two points on the seventh line from becoming too small, and allowing the second reference point to be determined with high accuracy. Then, by using the first reference point determined by detecting the first mark and the second reference point determined by detecting the second mark, the sheet inclination and the coordinate origin on the sheet can be determined with high accuracy.

[0038] In a sheet processing position correcting method according to the present invention, when a second mark, a third mark, and a fourth mark which surround the processing area together with the first mark are affixed to the sheet, the first mark, the second mark, the third mark, and the fourth mark are all right-angled triangles, and two orthogonal lines which form the right-angled triangle extend in the first scanning direction and the second scanning direction, a third scan in the first scanning direction and a fourth scan in the second scanning direction are performed on the second mark, and a second reference point indicating a position of the second mark is calculated based on detection results from the third scan and the fourth scan, at least one of the third scan and the fourth scan is performed along a scan line which passes through a second detection start point determined using the first reference point and shape data of the second mark, a fifth scan in the first scanning direction and a sixth scan in the second scanning direction are performed on the third mark, and It is preferable that a third reference point indicating the position of the third mark is calculated based on the detection results from the fifth scan and the sixth scan, at least one of the fifth scan and the sixth scan is performed along a scan line passing through a third detection start point determined using the second reference point and shape data of the third mark, a seventh scan in the first scanning direction and an eighth scan in the second scanning direction are performed on the fourth mark, a fourth reference point indicating the position of the fourth mark is calculated based on the detection results from the seventh scan and the eighth scan, at least one of the seventh scan and the eighth scan is performed along a scan line passing through a fourth detection start point determined using the third reference point and the shape data of the fourth mark, the position of the processing area and the inclination of the sheet are calculated based on the first reference point, the second reference point, the third reference point, and the fourth reference point, and the processing position is corrected based on the calculation results.

[0039] Further, in the sheet processing apparatus of the present invention, when a second mark, a third mark, and a fourth mark which surround the processing area together with the first mark are affixed to the sheet, the first mark, the second mark, the third mark, and the fourth mark are all right-angled triangles, and two orthogonal lines which form the right-angled triangle extend in the first scanning direction and the second scanning direction, the mark detection unit performs a third scan in the first scanning direction and a fourth scan in the second scanning direction on the second mark, and at least one of the third scan and the fourth scan is performed along a scan line which passes through a second detection start point determined using the first reference point and shape data of the second mark, the sheet processing position correction unit calculates a second reference point which indicates the position of the second mark based on detection results from the third scan and the fourth scan, the mark detection unit performs a fifth scan in the first scanning direction and a sixth scan in the second scanning direction on the third mark, and and at least one of the fifth and sixth scans is performed along a scanning line passing through a third detection start point determined using the second reference point and shape data of the third mark, and the sheet processing position correction unit calculates a third reference point indicating the position of the third mark based on the detection results of the fifth and sixth scans, the mark detection unit performs a seventh scan in the first scanning direction and an eighth scan in the second scanning direction with respect to the fourth mark, and at least one of the seventh scan and the eighth scan is performed along a scanning line passing through a fourth detection start point determined using the third reference point and shape data of the fourth mark, and the sheet processing position correction unit calculates a fourth reference point indicating the position of the fourth mark based on the detection results of the seventh scan and the eighth scan, and calculates the position of the processing area and the inclination of the sheet based on the first reference point, the second reference point, the third reference point, and the fourth reference point, and corrects the processing position based on the calculation results.

[0040] In this way, when detecting the second, third, and fourth marks, the detection start point is determined using the detection result of the most recently detected mark, so the detection start point can be brought closer to the ideal position. This allows the detection accuracy of each mark to be sequentially improved, so the second, third, and fourth reference points can be determined with high accuracy. Then, using the four reference points, the sheet inclination and the coordinate origin on the sheet can be determined with high accuracy.

[0041] According to the present invention, by simply scanning one mark twice, the inclination and reference point of the mark can be detected, and the inclination of the sheet and the coordinate origin on the sheet can be obtained from the inclination and reference point of the mark. Therefore, since it is only necessary to scan at least one mark to correct the processing position and the number of scans per mark is small, the inclination of the sheet and the coordinate origin on the sheet required for processing position correction can be easily obtained.

[0042] FIG. 1 is an explanatory diagram showing the configuration of a cutting device. FIG. 2 is an explanatory diagram showing an example of the arrangement of a cut area and marks on a sheet. FIG. 3 is an explanatory diagram showing a method for determining the inclination and reference point of a mark by two scans. FIG. 4 is a flowchart of a process for correcting the cut position by determining the inclination and reference point of a mark by two scans. FIG. 4 is an explanatory diagram of a scanning procedure when detecting marks in four locations. FIG. 5 is a schematic flowchart of a process for detecting marks in four locations and correcting the cut position. FIG. 6 is an explanatory diagram of a scanning line of a preliminary scan and a scan start point for a first scan and a scan start point for a second scan. FIG. 7 is a flowchart of a process for determining the detection start point for a second scan based on the results of the first scan. FIG. 8 is an explanatory diagram of a method for correcting the scanning position of a first scan based on the distance between two points detected by the first scan. FIG. 9 is a flowchart of a process for correcting the scanning position of a first scan based on the distance between two points detected by the first scan. FIG. 10 is an explanatory diagram of a method for determining the inclination of a mark by calculating the ratio of line widths. FIG. 11 is a flowchart of a process for canceling mark detection based on the ratio of line widths. FIG. 12 is an explanatory diagram showing another example of the arrangement of marks. FIG. 13 is an explanatory diagram showing an example in which the number of marks is changed. FIG. 14 is an explanatory diagram showing the configuration of a printing device. 1 is a diagram illustrating an example of the layout of a printing area and marks on a sheet, a sheet processing apparatus having a printing function and a cutting function, a sheet having a used processing area, and a sheet having a used processing area.

[0043] Hereinafter, with reference to the drawings, embodiments of a sheet processing position correction method and a sheet processing apparatus to which the present invention is applied will be described. The sheet processing apparatus of the present invention performs at least one of printing and cutting on a sheet. A processing area, such as a print area or a cut area, is set on the sheet, and at least one of printing and cutting is performed in the set processing area. In this case, the sheet processing apparatus corrects the processing position to eliminate any deviation between the set processing area and the processing position where printing or cutting is actually performed. The embodiments described below are a cutting position correction method and a cutting apparatus that correct the cutting position when cutting a sheet 10.

[0044] (Sheet) FIG. 1 is an explanatory diagram showing the configuration of a cutting device 1. FIG. 2 is an explanatory diagram showing an example of the arrangement of a cutting area 40 and marks on a sheet 10. In the example shown in FIG. 1, the sheet 10 includes a backing 11 such as a release paper, and an adhesive film 12 laminated on the surface of the backing 11. Note that the sheet 10 is not limited to this configuration, and may be any configuration that allows printing on the surface and that can be cut by a cutter 3, which will be described later. Also, while FIG. 2 shows a rectangular sheet 10, the shape of the sheet 10 is not limited to a rectangle. For example, instead of a standard sheet, a long sheet of a fixed width may also be used.

[0045] As shown in FIG. 2, a cutting area 40 is set on the sheet 10, and marks are placed outside the cutting area 40. The cutting area 40 may include, for example, a printing area (not shown) and a margin area set outside the printing area. Note that the margin area does not have to be set. The marks are placed so as to have a fixed positional relationship with the cutting area 40. In the example shown in FIG. 2, four marks, a first mark MA, a second mark MB, a third mark MC, and a fourth mark MD, are placed on the outer periphery of the four corners of the cutting area 40. These four marks are right-angled isosceles triangles and have the same shape.

[0046] As shown in FIG. 2 , the first mark MA, second mark MB, third mark MC, and fourth mark MD have two orthogonal sides that are parallel to the long and short sides of the sheet 10, respectively. The hypotenuses are inclined at 45° with respect to the two orthogonal sides. Therefore, the lengths of the two orthogonal sides are the same. The first mark MA is located at the upper left of the cutting area 40. The hypotenuse of the first mark MA faces the upper left corner of the cutting area 40. The second mark MB is located at the lower left of the cutting area 40. The hypotenuse of the second mark MB faces the lower left corner of the cutting area 40. The third mark MC is located at the lower right of the cutting area 40. The hypotenuse of the third mark MC faces the upper right corner of the cutting area 40. The fourth mark MD is located at the upper right of the cutting area 40. The hypotenuse of the fourth mark MD faces the lower right corner of the cutting area 40.

[0047] 1, the cutting device 1 includes a transport mechanism 2 that transports a sheet 10, a cutter 3 that cuts the sheet 10, a sensor 4 that outputs a detection signal corresponding to a mark when passing a position opposite the mark, a scanning mechanism 5 that moves the cutter 3 and the sensor 4 in a direction along the surface of the sheet 10, and a control unit 6 that controls the transport mechanism 2 and the scanning mechanism 5. The detection signal from the sensor 4 is input to the control unit 6. The sensor 4 is, for example, a reflective photosensor.

[0048] In this embodiment, an RGB sensor capable of detecting the amount of received red light, the amount of received green light, and the amount of received blue light is used as the sensor 4. When an RGB sensor is used, three types of received light amounts can be appropriately selected and used depending on the color of the mark to be detected and the background color of the sheet before printing.

[0049] The conveying mechanism 2 conveys the sheet 10 attracted to the surface of the platen 20. In Fig. 2, the conveying direction of the sheet 10 is indicated by the symbol PF. The conveying direction (hereinafter referred to as the PF direction) is the longitudinal direction of the sheet 10. In the example shown in Fig. 1, the conveying mechanism 2 includes a conveying roller 21 whose outer circumferential surface contacts the sheet 10, a pressure roller 22 that presses the sheet 10 against the conveying roller 21, a motor 24 that is a drive source, and a drive force transmission mechanism 23 that transmits the rotation of the motor 24 to the conveying roller 21.

[0050] The scanning mechanism 5 moves the carriage 25, on which the cutter 3 and the sensor 4 are mounted, in a first scanning direction that intersects with the PF direction. In FIGS. 1 and 2, the first scanning direction is indicated by the symbol CR. As shown in FIG. 2, in this embodiment, the first scanning direction (hereinafter referred to as the CR direction) is the width direction of the sheet 10 and is perpendicular to the PF direction. The scanning mechanism 5 includes, for example, a carriage shaft 26 extending in the CR direction and a drive force transmission mechanism such as a belt mechanism and a drive source such as a motor (not shown) as a mechanism for moving the carriage 25 along the carriage shaft 26. The scanning mechanism 5 is a first scanning mechanism that moves the sensor 4 relative to the sheet 10 in the first scanning direction.

[0051] The carriage 25 is provided with a mechanism (not shown) that moves the cutter 3 to a sheet cutting position where it protrudes toward the platen 20 and a retracted position where it is retracted to the opposite side of the platen 20. The cutting device 1 cuts the sheet 10 into any shape by combining the operation of conveying the sheet 10 and the operation of scanning the carriage 25 with the cutter 3 protruding to the sheet cutting position. Furthermore, by conveying the sheet 10 and the operation of scanning the carriage 25 with the cutter 3 retracted to the retracted position, the sensor 4 is moved relative to the sheet 10 in the CR direction and the PF direction. The PF direction is a second scanning direction. The transport mechanism 2 is a second scanning mechanism that moves the sensor 4 relative to the sheet 10 in the second scanning direction.

[0052] As shown in Figure 2, guide lines G are provided on the surface of the sheet 10 in addition to the marks. When the sheet 10 is set in the cutting device 1, the guide lines G are set so that they are roughly aligned with a specified position on the platen 20, for example, a mark on the platen 20. Alternatively, the sheet 10 may not have guide lines G. If the guide lines G are not provided, the sheet 10 is set so that a portion of the mark is aligned with a specified position on the platen 20. For example, the second line A2 of the first mark MA that is detected first is set so that it is aligned with a specified position on the platen 20.

[0053] Before starting the cutting operation, the cutting device 1 detects marks on the sheet 10 and, based on the detection results, calculates the position of the coordinate origin of the sheet 10 and the inclination of the sheet 10. Then, assuming that the position of the cutting area 40 relative to the coordinate origin of the sheet 10 is known, the cutting device 1 performs a cutting position correction process to correct the cutting line by the cutter 3 using the coordinate origin and the sheet inclination calculated from the mark detection results. This eliminates any misalignment between the outline line of the cutting area 40 and the cutting line, allowing for accurate cutting.

[0054] The control unit 6 of the cutting device 1 includes a mark detection unit 61 and a cutting position correction unit 62. The cutting position correction unit 62 corrects the processing position to eliminate any deviation between the set processing area (cut area) and the actual processing position (cut position). Therefore, the cutting position correction unit 62 is a sheet processing position correction unit. The mark detection unit 61 includes a detection start point determination unit 63. The mark detection unit 61 controls the transport mechanism 2 and the scanning mechanism 5 to perform scanning in the CR direction and the PF direction to detect marks, and calculates the coordinate origin of the sheet 10 set on the platen 20 and the inclination of the sheet 10 based on the detection results.

[0055] Before starting the CR direction scan and the PF direction scan, the detection start point determiner 63 determines a detection start point that serves as the starting point for each scan. Furthermore, based on the CR direction scan result, the detection start point that serves as the starting point for the PF direction scan is determined. Note that, since the scanning direction may be reversed when performing each scan, the detection start point may be the end point of the scan rather than the start point of the scan. Furthermore, the detection start point may be a passing point of the scan.

[0056] The cutting position correction unit 62 corrects the movement path of the cutter 3 when cutting the sheet 10 by moving the cutter 3 relative to the sheet 10 so as to correspond to the coordinate origin and the inclination of the sheet 10 found by calculation. This eliminates the misalignment between the outline line of the cutting area 40 and the cutting line.

[0057] The control unit 6 includes, for example, a hardware processor such as a CPU and a storage unit such as a non-volatile memory that stores various data and programs. The functions of the mark detection unit 61, the cut position correction unit 62, and the detection start point determination unit 63 are realized by the hardware processor reading and executing programs stored in the storage unit. Note that some or all of the functions of the control unit 6 may be realized by hardware such as an LSI, an ASIC, an FPGA, or a GPU.

[0058] Furthermore, the control unit 6 may be provided as a separate unit rather than being integrated with the cutting mechanism unit that includes the cutter 3, sensor 4, transport mechanism 2, and scanning mechanism 5. For example, in the case of a cutting device 1 that includes a general-purpose computer that controls the cutting mechanism unit, the computer may be configured to realize the functions of the control unit 6.

[0059] A print head may be mounted on the carriage 25 of the cutting device 1. In this case, printing on the cut area 40 of the sheet 10 and cutting of the cut area 40 can be performed by the same device. Therefore, the sheet 10 set in the cutting device 1 can be cut as is without being removed after printing.

[0060] (Correction of Cut Position Based on Two Scans) Fig. 3 is an explanatory diagram of a method for determining the inclination and reference point of a mark by two scans. Fig. 4 is a flowchart of a process for determining the inclination and reference point of a mark by two scans and correcting the cut position. Below, with reference to Figs. 3 and 4, correction of the cut position based on two scans for one mark located on the outer periphery of the cut area 40 will be described.

[0061] 3, the first mark MA has a first line A1 and a second line A2 that are perpendicular to each other, and a third line A3 that is inclined at 45° with respect to the first line A1 and the second line A2. The first line is parallel to the long side of the sheet 10. The second line A2 is parallel to the short side of the sheet 10. The first mark MA is a right-angled isosceles triangle, and the mark width W in the CR direction and the mark width W in the PF direction are the same.

[0062] With the cutter 3 retracted to a retracted position, the mark detection unit 61 controls the conveying mechanism 2 and the scanning mechanism 5 to convey the sheet 10 and scan the carriage 25, performing a first scan to move the sensor 4 relative to the sheet 10 in the CR direction, and a second scan to move the sensor 4 relative to the sheet 10 in the PF direction.

[0063] 4, before performing the first and second scans, the mark detection unit 61 performs a process of determining a first detection start point NA using the detection start point determiner 63 (step S1). The method of determining the first detection start point NA will be described later. Next, a first scan is performed along a scan line L1 that passes through the first detection start point NA (step S2), and then a second scan is performed along a scan line L2 that passes through the first detection start point NA (step S3).

[0064] As shown in FIG. 3 , the scanning line L1 of the first scan intersects with the first line A1 and the third line A3. The first scan detects a first detection point P1, which is the intersection of the scanning line L1 and the first line A1, and a third detection point P3, which is the intersection of the scanning line L1 and the third line A3. Meanwhile, the scanning line L2 of the second scan intersects with the second line A2 and the third line A3. The second scan detects a second detection point P2, which is the intersection of the scanning line L2 and the second line A2, and a fourth detection point P4, which is the intersection of the scanning line L2 and the third line A3. The scanning lines L1 and L2 are set so that the third detection point P3 and the fourth detection point P4 do not coincide with each other.

[0065] In step S2, the mark detection unit 61 determines the coordinates of the first detection point P1 and the third detection point P3 from the output of the sensor 4. In step S3, the mark detection unit 61 determines the coordinates of the second detection point P2 and the fourth detection point P4 from the output of the sensor 4. At this time, the coordinates of each detection point are calculated by calculating the coordinates on the center line of the first line A1, the second line A2, and the third line A3, as shown in the partially enlarged view of FIG.

[0066] 3, in step S2, the coordinates of the intersection E1 between one edge of the first line A1 and the scanning line L1 and the coordinates of the intersection E2 between the other edge of the first line A1 and the scanning line L1 are determined, and then the coordinates of the center point of the line connecting E1 and E2 are calculated, and the obtained coordinates are determined as the coordinates of the first detection point P1. Also, the coordinates of the intersection E3 between one edge of the third line A3 and the scanning line L1 and the coordinates of the intersection E4 between the other edge of the third line A3 and the scanning line L1 are determined, and then the coordinates of the center point of the line connecting E3 and E4 are calculated, and the obtained coordinates are determined as the coordinates of the third detection point P3.

[0067] Although not shown in FIG. 3 , in step S3, the coordinates of the second detection point P2 and the fourth detection point P4 are similarly determined. That is, after determining the coordinates of the intersection between one edge of the second line A2 and the scanning line L2 and the coordinates of the intersection between the other edge of the second line A2 and the scanning line L2, the coordinates of the center point of the line connecting the determined two points are calculated, and the obtained coordinates are determined as the coordinates of the second detection point P2. Also, after determining the coordinates of the intersection between one edge of the third line A3 and the scanning line L2 and the coordinates of the intersection between the other edge of the third line A3 and the scanning line L2, the coordinates of the center point of the line connecting the determined two points are calculated, and the obtained coordinates are determined as the coordinates of the fourth detection point P4.

[0068] The mark detection unit 61 performs the process of step S4 on the assumption that the shape data of the first mark MA is known. That is, the mark detection unit 61 calculates the angle indicating the inclination of the sheet 10 and the coordinates of the first reference point CA indicating the position of the first mark MA from the shape data of the first mark MA and the coordinates of the four detected points (first detection point P1, second detection point P2, third detection point P3, and fourth detection point P4) (step S4).

[0069] In step S4, the mark detection unit 61 determines a straight line passing through the third detection point P3 and the fourth detection point P4, i.e., a straight line that coincides with the third line A3. If the first mark MA is a right-angled isosceles triangle and the inclination of the sheet 10 is 0°, the inclination of the third line A3 is 45°. Therefore, for example, the angle indicating the inclination of the sheet 10 can be determined as the difference between the inclination R of the line passing through the third detection point P3 and the fourth detection point P4 and 45°.

[0070] Next, if a line that passes through the first detection point P1 and is inclined 45 degrees counterclockwise in Figure 3 with respect to a line that passes through the third detection point P3 and the fourth detection point P4 is found, this line will coincide with the first line A1. Similarly, if a line that passes through the second detection point P2 and is inclined 45 degrees clockwise in Figure 3 with respect to a line that passes through the third detection point P3 and the fourth detection point P4 is found, this line will coincide with the second line A2. Therefore, it is possible to find the first reference point CA, which is the intersection of the first line A1 and the second line A2.

[0071] The cutting position correction unit 62 performs a cutting position correction process to correct the cutting line by the cutter 3 using the angle indicating the inclination of the sheet 10 calculated in step S4 and the coordinates of the first reference point CA (step S5). If the relative position of the first reference point CA with respect to the coordinate origin of the sheet 10 is known, the coordinate origin of the sheet 10 can be calculated from the coordinates of the first reference point CA. Therefore, as described above, it is possible to eliminate the misalignment between the outline of the cutting area 40 and the cutting line by the cutter 3, thereby enabling accurate cutting.

[0072] (Target Position of Detection Start Point) Here, the first and second scans are performed by setting the positions of the scanning lines L1 and L2 so that the third detection point P3 and the fourth detection point P4 do not coincide with each other. Furthermore, it is preferable to set the positions of the scanning lines L1 and L2 so that the two detection points on the third line A3 are not too close to each other. If the third detection point P3 and the fourth detection point P4 are too close to each other, the detection accuracy of these two points will significantly affect the detection accuracy of the slope of the line coinciding with the third line A3. Therefore, it may be difficult to accurately determine the slope R of the line coinciding with the third line A3.

[0073] The mark detection unit 61 sets target positions of the scanning lines L1 and L2 and performs the first and second scans, with the condition that the third detection point P3 and the fourth detection point P4 are not too close to each other. For example, the target positions of the scanning lines L1 and L2 are set so that the distance between the third detection point P3 and the fourth detection point P4 is equal to or greater than a predetermined distance, e.g., equal to or greater than one-third the length of the third line A3, which is the oblique side. The target positions of the scanning lines L1 and L2 are also set so that the scanning line L1 reliably intersects the first line A1 and the third line A3, and the scanning line L2 reliably intersects the second line A2 and the third line A3.

[0074] The process of determining the first detection start point NA in step S1 is a process for setting the target positions of the scanning lines L1 and L2. In step S1, for example, as shown in Fig. 3, the first detection start point NA is determined outside the third line A3. In this case, the coordinates of the ideal first detection start point NA are those shifted from the second line A2 in the PF direction by 2 / 3 of the mark width W and further shifted from the first line A1 in the CR direction by 2 / 3 of the mark width W.

[0075] In step S2, scanning is performed in the CR direction, starting or ending at the first detection start point NA. In step S3, scanning is performed in the PF direction, starting or ending at the first detection start point NA. This ensures that four points (first detection point P1, second detection point P2, third detection point P3, and fourth detection point P4) are detected, and the distance between the third detection point P3 and the fourth detection point P4 is one-third the length of the third line A3.

[0076] The first detection start point NA may be set at a position farther from the third line A3 than the position shown in Fig. 3. In this case, the distance between the third detection point P3 and the fourth detection point P4 can be set to be greater than one-third of the length of the third line A3.

[0077] The first detection start point NA shown in FIG. 3 can be determined, for example, from the results of a preliminary scan performed before the first and second scans. The preliminary scan will be described later. Note that the method for determining the first detection start point NA is not limited to the method based on the preliminary scan described later. For example, the sheet 10 can be set so that the guide line G or a portion of the mark (e.g., the second line A2) is roughly aligned with a mark on the platen 20, and then the edge of the sheet 10 is detected by scanning in the CR direction, the guide line G is detected by scanning in the PF direction, and the point moved a certain amount in the PF direction from the guide line G or the second line A2 and further moved a certain amount in the CR direction from the edge of the sheet 10 can be determined as the first detection start point NA.

[0078] (Correction of Cut Position Based on Detection of Four Marks) Fig. 5 is an explanatory diagram of the scanning procedure when detecting marks in four locations. Fig. 6 is a schematic flowchart of the process of detecting marks in four locations and correcting the cut position. Below, with reference to Figs. 5 and 6, correction of the cut position based on scanning the four marks surrounding the cut area 40 once in the CR direction and once in the PF direction will be described. Preliminary scanning will also be described.

[0079] Of the four marks, the shape of the first mark MA located in the upper left of the cutting area 40 is as described in Fig. 3. As shown in Fig. 5, the second mark MB located in the lower left of the cutting area 40 has fifth and sixth lines B1 and B2 that are perpendicular to each other and a seventh line B3 that is inclined at 45 degrees relative to the fifth and sixth lines B1 and B2. The third mark MC located in the lower right of the cutting area 40 has ninth and tenth lines C1 and C2 that are perpendicular to each other and an eleventh line C3 that is inclined at 45 degrees relative to the ninth and tenth lines C1 and C2. The fourth mark MD located in the upper right of the cutting area 40 has thirteenth and fourteenth lines D1 and D2 that are perpendicular to each other and a fifteenth line D3 that is inclined at 45 degrees relative to the thirteenth and fourteenth lines D1 and D2.

[0080] The detection start point determination unit 63 performs a preliminary scan before starting detection of the first mark MA (steps S11 and S12). As described above, when setting the sheet 10 on the platen 20, the position of the sheet 10 in the PF direction can be roughly adjusted by aligning the guide line G on the sheet 10 or a part of the mark (e.g., the second line A2) with a mark on the platen 20. When the guide line G is used, the relative position of the first mark MA with respect to the guide line G is known. In addition, the shape data of the first mark MA is known, and the mark width W in the PF direction is also known.

[0081] In step S11, the detection start point determiner 63 controls the transport mechanism 2 and the scanning mechanism 5 to move the sensor 4 to the start position of the pre-scan, assuming that the guide line G or a part of the mark (e.g., the second line A2) is aligned with a mark on the platen 20. For example, the transport mechanism 2 is driven to transport the sheet 10 in the -PF direction by the distance from the guide line G or the second line A2 to the scan line of the pre-scan (e.g., ⅔ of the mark width W). The scanning mechanism 5 is also driven to move the carriage 25 in the +CR direction by the distance from the edge of the sheet 10 in the CR direction to the start position of the pre-scan (e.g., a predetermined dimension narrower than the width of the margin area in the CR direction).

[0082] In step S12, the detection start point determiner 63 drives the scanning mechanism 5 to perform one scan in the CR direction as a preliminary scan. This detects the intersections of the preliminary scan scanning line (not shown) with the first line A1 and the third line A3. The intersections of the preliminary scan scanning line with the first line A1 and the third line A3 are calculated by computing points on the center lines of each line. That is, the coordinates of the center points of the lines connecting the two intersections of the scanning line with both side ends of each line are calculated.

[0083] Then, a first detection start point NA for detecting the first mark MA is determined based on the coordinates of two intersections of the scanning line of the preliminary scan with the first line A1 and the third line A3. The ideal position of the first detection start point NA is as described with reference to FIG.

[0084] For example, to determine the ideal position of the first detection start point NA, the distance between two points detected in the pre-scan is calculated, and the coordinate of the first detection start point NA in the PF direction can be determined based on the distance between the two points and the shape data of the first mark MA.Then, the coordinate of the first detection start point NA in the CR direction can be determined based on the coordinate of the intersection of the scanning line of the pre-scan and the first line A1 or the third line A3.

[0085] The detection start point determination unit 63 sets the movement speed of the carriage 25 during the pre-scanning to be faster than the movement speed of the carriage 25 during the first scan and the conveyance speed of the sheet 10 during the second scan, thereby reducing the time required for the pre-scanning.

[0086] Next, the mark detection unit 61 performs steps S13 and S14 on the first mark MA. In step S13, a first scan in the CR direction and a second scan in the PF direction are performed on the first mark MA along scanning lines L1 and L2, each starting, ending, or passing through the first detection start point NA. Next, in step S14, the tilt of the sheet 10 and the coordinates of the first reference point CA are calculated using the detection results of the four points from these two scans. The details of steps S13 and S14 are as described in steps S2 to S4 of FIG. 4.

[0087] Next, the mark detection unit 61 performs steps S15 and S16 on the second mark MB. In step S15, the detection start point determination unit 63 determines a second detection start point NB. The mark detection unit 61 performs a third scan along a scan line L3 in the CR direction and a fourth scan along a scan line L4 in the PF direction on the second mark MB, each time passing through the determined second detection start point NB.

[0088] For example, assuming that the shape data of the second mark MB and the data on the relative position of the second mark MB with respect to the first mark MA are known, the detection start point determiner 63 determines the second detection start point NB from the inclination of the sheet 10 calculated in the immediately preceding step S14 and the coordinates of the first reference point CA. Then, the third and fourth scans are performed using the second detection start point NB as the start point, end point, or passing point.

[0089] In step S15, four points are detected: a fifth detection point P5, which is the intersection of the scanning line L3 of the third scan with the fifth line B1; a seventh detection point P7, which is the intersection of the scanning line L3 with the seventh line B3; a sixth detection point P6, which is the intersection of the scanning line L4 of the fourth scan with the sixth line B2; and an eighth detection point P8, which is the intersection of the scanning line L4 with the seventh line B3. These four points are points on the center lines of the fifth line B1, the sixth line B2, and the seventh line B3, and are determined by calculating the coordinates of the center points of the straight lines connecting the two intersections of the side ends of each line with the scanning line.

[0090] Next, the process proceeds to step S16, where the coordinates of the second reference point CB are calculated using the coordinates of the four points detected by the third and fourth scans of the second mark MB. Furthermore, the inclination of the sheet 10 is calculated using the coordinates of the first reference point CA and the second reference point CB, which are determined by detecting the first mark MA. For example, the inclination of the sheet 10 is determined as the angle between the line connecting the first reference point CA and the second reference point CB and the PF direction.

[0091] Next, the mark detection unit 61 performs steps S17 and S18 on the third mark MC. In step S17, the detection start point determination unit 63 determines a third detection start point NC. The mark detection unit 61 performs a fifth scan along a scan line L5 in the CR direction and a sixth scan along a scan line L6 in the PF direction on the third mark MC, each of which passes through the determined third detection start point NC.

[0092] For example, assuming that the shape data of the third mark MB and the data on the relative position of the third mark MC with respect to the second mark MB are known, the detection start point determiner 63 determines the third detection start point NC from the inclination of the sheet 10 calculated in the immediately preceding step S16 and the coordinates of the second reference point CB. Then, the fifth and sixth scans are performed using the third detection start point NC as the starting point, ending point, or passing point. This results in the detection of four points: the ninth detection point P9, the tenth detection point P10, the eleventh detection point P11, and the twelfth detection point P12 shown in FIG. 5 . Like the detection points on the other marks, these four points are points on the center lines of the ninth line C1, the tenth line C2, and the eleventh line C3.

[0093] Next, the process proceeds to step S18, where the coordinates of the third reference point CC are calculated using the coordinates of the four points detected by the fifth and sixth scans for the third mark MC. The third reference point CC is not used to calculate the sheet inclination; instead, the inclination calculated from the first reference point CA and the second reference point CB is used as is without updating. The reason for this is that the distance between the first reference point CA and the second reference point CB, which are aligned along the long side of the sheet 10, is longer than the distance between the second reference point CB and the third reference point CC, which are aligned along the short side of the sheet 10. Therefore, calculating the inclination of the line connecting CA and CB allows for more accurate calculation of the inclination of the sheet 10 than calculating the inclination of the line connecting CB and CC. Therefore, in the case of a mark arrangement in which the distance between the two points CB and CC is longer than the distance between the two points CA and CB, the inclination of the sheet 10 is updated by calculating the inclination of the line connecting the two points CB and CC in step S18.

[0094] Next, the mark detection unit 61 performs steps S19 and S20 on the fourth mark MD. In step S19, the detection start point determination unit 63 determines a fourth detection start point ND. The mark detection unit 61 performs a seventh scan along a scan line L7 in the CR direction and an eighth scan along a scan line L8 in the PF direction on the fourth mark MD, each of which passes through the determined fourth detection start point ND.

[0095] For example, assuming that the shape data of the fourth mark MB and the data on the relative position of the fourth mark MD with respect to the third mark MC are known, the detection start point determiner 63 determines the fourth detection start point ND using the coordinates of the third reference point CC calculated in the immediately preceding step S18 and the inclination of the sheet 10 calculated from the two points CA and CB in step S16, or the inclination of the sheet 10 calculated and updated from the two points CB and CC in step S18. Then, the seventh and eighth scans are performed using the fourth detection start point ND as the starting point, ending point, or passing point. This detects four points: the thirteenth detection point P13, the fourteenth detection point P14, the fifteenth detection point P15, and the sixteenth detection point P16 shown in FIG. 5 . These four points are points on the center lines of the thirteenth line D1, the fourteenth line D2, and the fifteenth line D3.

[0096] Next, proceeding to step S20, the coordinates of the fourth reference point CD are calculated using the coordinates of the four points detected by the seventh and eighth scans of the fourth mark MD. Furthermore, the inclination of the sheet 10 is calculated using the coordinates of the third reference point CC and the fourth reference point CD.

[0097] The cutting position correction unit 62 performs a cutting position correction process to correct the cutting line by the cutter 3 using the four reference points (first reference point CA, second reference point CB, third reference point CD, and fourth reference point CD) determined in steps S14, S16, S18, and S20. From the coordinates of these four points, the coordinate origin of the sheet 10 and the inclination of the sheet 10 can be determined with high precision. Therefore, it is possible to eliminate the misalignment between the outline of the cutting area 40 and the cutting line by the cutter 3, and to perform cutting with high precision.

[0098] The cutting position correction unit 62 can also use the four reference points to calculate the expansion / contraction ratio in the PF direction and the expansion / contraction ratio in the CR direction of the sheet 10. Then, based on the calculated expansion / contraction ratio, it can perform a cutting position correction process to correct the cutting line by the cutter 3.

[0099] The above describes a method for correcting the cutting position by detecting four marks surrounding the cutting area 40, but the number of marks used for cutting position correction is not limited to four. For example, if two marks, the first mark MA and the second mark MB, are detected, the inclination of the sheet 10 can be calculated from two distant reference points. Therefore, cutting position correction may be performed based on the detection results of the two marks. Also, cutting position correction may be performed by detecting any three of the four marks. Alternatively, five or more marks may be added, and cutting position correction may be performed by detecting the five or more marks.

[0100] (Determining Sheet Orientation) The above method assumes that the sheet 10 is set in the correct orientation, but there is a possibility that the sheet 10 may be set sideways or upside down. Furthermore, if the guide lines G are not used for the preliminary scan, it is not possible to determine before starting mark detection that the sheet 10 is set in the correct orientation. In the above method, even if the orientation of the sheet 10 differs in this way, additional processing can be added to ensure that the four marks are reliably detected and the cutting position can be corrected. For example, the following can be done.

[0101] 2, since the sheet 10 in this embodiment is rectangular, the distance between two marks aligned in the width direction of the sheet 10 is narrower than the distance between two marks aligned in the length direction of the sheet 10. In step S15 of Fig. 6, first, assuming that the orientation of the sheet 10 is set correctly, a second detection start point NB is determined based on the distance between the two marks aligned in the length direction of the sheet 10. Then, a third scan is performed using the determined second detection start point NB as the start point, end point, or pass point.

[0102] If the sheet 10 is set in landscape orientation rather than the correct orientation (portrait), the scan line L3 of the third scan will not intersect with the mark. The mark detection unit 61 determines from the output of the sensor 4 during the third scan that an intersection with the mark has not been detected. If an intersection with the mark has not been detected, the detection start point determination unit 63 resets the second detection start point NB based on the spacing between two marks aligned in the width direction of the sheet 10, rather than the length direction. Thereafter, steps S15 and S16 are performed as described above.

[0103] If the second detection start point NB is reset, when steps S17 and S19 are performed, the mark detection unit 61 determines the third detection start point NC and the fourth detection start point ND based on the relative positions of the four marks when the sheet 10 is set landscape. In this way, it is possible to determine that the sheet 10 has been rotated and set landscape, and the four marks can be reliably detected.

[0104] Next, in step S21, a cutting position correction process is performed using the coordinates of the four reference points to correct the cutting line by the cutter 3. At this time, if the arrangement of the four reference points with respect to the cutting area 40 is symmetrical in both the PF direction and the CR direction, the position of the cutting area 40 can be calculated by knowing the coordinates of the four reference points.

[0105] On the other hand, if the arrangement of the four reference points relative to the cutting area 40 is not symmetrical in either or both of the PF and CR directions, it may not be possible to calculate the correct position of the cutting area 40 unless it is determined that the sheet 10 has been set upside down, and if the sheet 10 has been set sideways, it is determined whether it has rotated to the right or left.

[0106] Therefore, a first reference point determination process for determining which of the four detected points is the first reference point CA can be incorporated between steps S20 and S21 in Fig. 6. For example, a process for detecting the reference point mark MK shown in Fig. 5 is performed. The reference point mark MK is placed at a predetermined position relative to the first mark MA. In the example shown in Fig. 5, the reference point mark MK is placed at a position symmetrical to the first reference point CA with respect to the third line A3.

[0107] In the first reference point discrimination process, based on the coordinates of the four detected reference points, candidate coordinates are determined for each of the four reference points that have the same relative positional relationship as the relative position of the reference point mark MK with respect to the first reference point CA. Then, the sensor 4 is moved sequentially to the four determined candidate coordinates, and the read values ​​of the output of the sensor 4 when facing each candidate coordinate are compared, and the reference point corresponding to the candidate coordinate with the lowest read value level is determined to be the first reference point CA. This makes it possible to identify which reference point each of the four detected reference points is.

[0108] In the cut position correction process (step S21), based on the results of the first reference point discrimination process, it is possible to determine whether the sheet 10 has been set upside down, and whether the sheet 10 has rotated to the right or left if it has been set sideways.Therefore, based on the discrimination results, the position and orientation of the cut area 40 can be identified and the cut position can be corrected.

[0109] (Determining the Detection Start Point for the Second Scan Based on the Results of the First Scan) FIG. 7 is an explanatory diagram of the scanning line L0 of the preliminary scan, and the detection start point NA1 for the first scan and the detection start point NA2 for the second scan based on the results of the first scan. FIG. 8 is a flowchart of the process of determining the detection start point NA2 for the second scan based on the results of the first scan. In the method described with reference to FIGS. 5 and 6, the first scan and the second scan are performed along scanning lines L1 and L2 that pass through the same first detection start point NA. Below, with reference to FIGS. 7 and 8, a method will be described in which the first detection start point NA determined by the preliminary scan is used only for the first scan, and the detection start point NA2 for the second scan is determined based on the results of the first scan.

[0110] In step S31, the detection start point determiner 63 determines a detection start point NA1 for the first scan based on the detection results of the preliminary scan, i.e., the intersections P00 and P01 (see FIG. 7) of the scanning line L0 of the preliminary scan with the first line A1 and the third line A3, and the shape data of the first mark MA. This determination can be made in the same manner as the determination of the first detection start point NA described in the explanation of step S12 in FIG. 6.

[0111] That is, as shown in the upper diagram of Figure 7, the distance between the two intersection points P00 and P01 is calculated, and the amount of movement in the +PF direction or -PF direction from the preliminary scanning line L0 to the ideal scanning line L1 is determined from the calculated distance. As shown in Figure 3, the ideal scanning line L1 is located at a position two-thirds of the mark width W. This determines the PF-direction coordinate of the detection start point NA1 for the first scan. Furthermore, the CR-direction coordinate of the detection start point NA1 for the first scan may be determined from the coordinate of the intersection point P00 or P01.

[0112] Next, in step S32, the mark detection unit 61 performs a first scan along the scan line L1 that passes through the detection start point NA1 for the first scan, and determines the coordinates of the first detection point P1 and the second detection point P2. For example, the sensor 4 is relatively moved in the +PF direction by conveying the sheet 10 in the -PF direction by the distance from the scan line L0 to the scan line L1. Thereafter, the carriage 25 is moved in the +CR direction to perform a first scan that ends at the detection start point NA1 for the first scan.

[0113] Next, in step S33, the detection start point determiner 63 determines a detection start point NA2 for the second scan using the coordinates of the first detection point P1. For example, as shown in the lower diagram of FIG. 7 , the detection start point NA2 for the second scan is determined to be a point moved a specified distance (2 / 3 of the mark width W) from the first detection point P1 toward the side where the third detection point P3 is located (i.e., in the +CR direction) from the first detection point P1. Note that the detection start point NA2 for the second scan can also be determined using the coordinates of the third detection point P3. That is, the detection start point NA2 for the second scan may be determined to be a point moved 1 / 3 of the mark width W in the +CR direction from the third detection point P3.

[0114] Then, in step S34, the mark detection unit 61 performs a second scan along the scan line L2 that passes through the detection start point NA2 for the second scan, and determines the coordinates of the second detection point P2 and the fourth detection point P4. For example, the carriage 25 is moved in the +CR direction to position the sensor 4 at the detection start point NA2 for the second scan. Thereafter, the sheet 10 is transported in the -PF direction to relatively move the sensor 4 in the +PF direction, and a second scan is performed starting from the detection start point NA2 for the second scan.

[0115] In this way, by determining the detection start point NA2 for the second scan from the results of the first scan, the scanning line L2 for the second scan can be brought closer to the ideal position, and the four detection points can be brought closer to the ideal positions.

[0116] As described above, the methods described with reference to FIGS. 3 and 4 and the methods described with reference to FIGS. 5 and 6 all involve performing the first scan and the second scan with the same detection start point as the start point or the end point. However, in steps S1 to S3 in FIG. 3 and steps S12 to S13 in FIG. 5, the processing of steps S31 to S34 in FIG. 7 can be performed, and the detection start point for the second scan can be determined using the scan result of the first scan.

[0117] Similarly, when detecting the three marks other than the first mark MA, the start point or end point of the scan in the PF direction can be determined using the results of the scan in the CR direction. That is, when detecting the second mark MB, the third scan can be performed so as to pass through the second detection start point NB (i.e., the detection start point for the third scan) determined using the first reference point CA and the shape data of the second mark MB, and the fourth scan can be performed so as to pass through the detection start point for the fourth scan determined based on the results of the third scan. Similarly, when detecting the third mark MC, the fifth scan can be performed so as to pass through the third detection start point NC (i.e., the detection start point for the fifth scan) determined using the second reference point CB and the shape data of the third mark MC, and the sixth scan can be performed so as to pass through the detection start point for the sixth scan determined based on the results of the fifth scan. Furthermore, when detecting the fourth mark MB, the seventh scan can be performed so as to pass through the fourth detection start point ND (i.e., the detection start point for the seventh scan) determined using the shape data of the third reference point CC and the fourth mark MD, and the eighth scan can be performed so as to pass through the detection start point for the eighth scan determined based on the results of the seventh scan.

[0118] (Correction of Scanning Position of First Scan) Fig. 9 is an explanatory diagram of a method for correcting the scanning position of the first scan based on the distance between two points detected by the first scan. Fig. 10 is a flowchart of a process for correcting the scanning position of the first scan based on the distance between two points detected by the first scan. The process for correcting the scanning position of the first scan will be described below with reference to Figs. 9 and 10.

[0119] 9 is a scanning line that passes through a detection start point (not shown in FIG. 9) that is determined by a preliminary scan or the like before the first scan is performed. The mark detection unit 61 performs a first first scan along the scanning line L1(1) and determines a first detection point P1(1) and a third detection point P3(1) from the sensor output (step S41).

[0120] Next, the process proceeds to step S42, where the distance S0 between the two detected points (first detection point P1(1) and third detection point P3(1)) is calculated. If the scanning line L1(1) is set at the ideal position, the distance S0 should be equal to W×1 / 3. In step S42, it is determined whether the distance S0 is within an allowable range that includes W×1 / 3. For example, it is determined whether the distance S0 is within a range of ±5% from the target value W×1 / 3. If the distance S0 is not within the allowable range (step S42: No), the process proceeds to step S43. Note that the allowable range is not limited to ±5% of the target value, and a wider or narrower range may be set.

[0121] In step S43, the amount of movement of the scanning position (scanning line) in the PF direction is determined by calculation based on the value of distance S0. For example, if the value of distance S0 - (1 / 3 of the mark width W) is positive, its absolute value is determined as the amount of movement in the +PF direction. On the other hand, if this value is negative, its absolute value is determined as the amount of movement in the -PF direction. The transport mechanism 2 is controlled to transport the sheet 10 in the -PF direction or +PF direction, and the sensor 4 is moved relative to the sheet 10 in the +PF direction or -PF direction.

[0122] In step S43, the mark detection unit 61 performs a second first scan along the moved scan line L1(2) and determines the first detection point P1(2) and the third detection point P3(2) from the sensor output, and then returns to step S42.

[0123] If it is determined in step S42 that the distance S0 is within the allowable range (step S42: Yes), the process proceeds to step S45. The two points detected in the immediately preceding first scan are then determined as the first detection point P1 and the third detection point P3. Figure 9 shows a case where the distance S between the first detection point P1(2) and the third detection point P3(2) detected in the second scan is 1 / 3 of the mark width W.

[0124] In this way, when performing the first scan, the position of the scanning line L1 in the PF direction can be corrected and brought closer to the ideal position by determining whether the distance between the two detected points is within the allowable range, thereby bringing the first detection point P1 and the third detection point P3 closer to the ideal position.

[0125] As described above, the methods described with reference to Figures 3 and 4 and the methods described with reference to Figures 7 and 8 all involve a first scan. Therefore, in step S2 of Figure 4 and step S32 of Figure 8, it is possible to perform the processing of steps S41 to S45 of Figure 10. Furthermore, in the detection of four marks described with reference to Figures 5 and 6, two-directional scanning is performed once each to detect the three marks other than the first mark MA, so when the first scan is performed, the distance between the two detected points can be calculated and the scanning position can be corrected.

[0126] (Stopping Mark Detection Based on Line Width Ratio) Fig. 11 is an explanatory diagram of a method for determining the inclination of a mark by calculating the line width ratio. Fig. 12 is a flowchart of a process for stopping mark detection based on the line width ratio. Below, with reference to Figs. 11 and 12, a method will be described in which, when performing the first scan, the line widths of the first line A1 and the third line A3 are calculated to determine the inclination of the mark, and mark detection is stopped if the inclination is large.

[0127] 11 , after the first scan (step S51), the mark detection unit 61 determines the line width d1 of the first line A1 and the line width d2 of the third line A3 from the output of the sensor 4 (step S52). In the first scan, coordinates of intersections E1 and E2 between both side edges of the first line A1 and the scanning line L1, and coordinates of intersections E3 and E4 between both side edges of the third line A3 and the scanning line L1 are used to calculate the points on the center line of each line. In step S52, the line width d1 of the first line A1 and the line width d2 of the third line A3 are calculated from the coordinates of these four points.

[0128] The mark detection unit 61 proceeds to step S53 and calculates the line width ratio d2 / d1. Then, by determining whether the line width ratio d2 / d1 is within a reference range, it determines whether the tilt of the first mark MA is within a reference range. As shown in FIG. 11, if the tilt θ of the first mark MA (in FIG. 11, the tilt of the second line A1 with respect to the CR direction is indicated as θ) is 0°, the line width ratio d2 / d1 = 1.44. If the tilt θ of the second line A1 with respect to the CR direction is ±5°, the line width ratio d2 / d1 satisfies the following relational expression (1). In step S53, it is determined whether the line width ratio d2 / d1 satisfies the relational expression (1): 1.31≦(d2 / d1)≦1.55 (1)

[0129] If the line width ratio d2 / d1 is within the reference range (step S53: Yes), the process proceeds to step S54, where the first detection point P1 and the third detection point P3 are determined. Specifically, the first detection point P1 is calculated from the coordinates of the intersections E1 and E2, and the third detection point P3 is calculated from the coordinates of the intersections E3 and E4.

[0130] If the line width ratio d2 / d1 is not within the reference range (step S53: No), the process proceeds to step S55. Then, it is determined that the inclination of the first mark MA is too large, and a detection error is detected, and detection of the first mark MA is stopped.

[0131] If the inclination of the marks is too large, it may be impossible to detect the four points with one scan each in the CR and PF directions. Even if the four points are detected, they may not be ideally positioned. In this case, even if the first reference point CA and the inclination of the sheet 10 are calculated, accurate values ​​may not be obtained, and cutting position correction may not be performed accurately. Therefore, by stopping mark detection based on the line width ratio, it is possible to avoid low-accuracy cutting position correction.

[0132] (Operation and Effect) As described above, the cutting position correction method of this embodiment detects a first mark MA indicating a cut area 40 on a sheet 10 using the sensor 4, and corrects the cutting position when cutting the cut area 40. The first mark MA includes a first line A1, a second line A2, and a third line A3 that extend in different directions and do not intersect at the same point. A first scan is performed by moving the sensor 4 relative to the sheet 10 in the CR direction, and a first detection point P1 is detected as an intersection of the scanning line L1 of the first scan and the first line A1, and a third detection point P3 is detected as an intersection of the scanning line L1 of the first scan and the third line A3. A second scan is performed by moving the sensor 4 relative to the sheet 10 in the PF direction that intersects with the CR direction, and a second detection point P2 is detected as an intersection of the scanning line L2 of the second scan and the second line A2, and a fourth detection point P4 is detected as an intersection of the scanning line L2 of the second scan and the third line A3, which is different from the third detection point P3. Based on the first shape data indicating the shape of the first mark MA and the coordinates of the first detection point P1, the second detection point P2, the third detection point P3, and the fourth detection point P4, the first reference point CA indicating the position of the first mark MA and the inclination of the sheet 10 are calculated, and the cutting position is corrected based on the calculation results.

[0133] The cutting device 1 of this embodiment also includes a cutter 3 for cutting the sheet 10, a sensor 4 for detecting a first mark MA indicating a cut area 40 on the sheet 10, a scanning mechanism 5 which is a first scanning mechanism that moves the sensor 4 relatively to the sheet 10 in a first scanning direction, a transport mechanism 2 which is a second scanning mechanism that moves the sensor 4 relatively to the sheet 10 in a PF direction that intersects the CR direction, and a control unit 6 which controls the scanning mechanism 5 and the transport mechanism 2 and to which a detection signal from the sensor 4 is input. The first mark MA includes a first line A1, a second line A2, and a third line A3 which extend in directions that intersect with each other but do not intersect at the same point. The control unit 6 performs a first scan by driving the scanning mechanism 5 to move the sensor 4 relative to the sheet 10 in the CR direction, and a second scan by driving the conveying mechanism 2 to move the sensor 4 relative to the sheet 10 in the PF direction.The control unit 6 further includes a mark detection unit 61 that detects, from the output of the sensor 4 in the first scan, a first detection point P1 which is the intersection of the scanning line L1 of the first scan and the first line A1, and a third detection point P3 which is the intersection of the scanning line L1 of the first scan and the third line A3, and detects, from the output of the sensor 4 in the second scan, a second detection point P2 which is the intersection of the scanning line L2 of the second scan and the second line A2, and a fourth detection point P4 which is the intersection of the scanning line L2 of the second scan and the third line A3 and is different from the third detection point P3. The control unit 6 also includes a cut position correction unit 62 that calculates a first reference point CA indicating the position of the first mark MA and the inclination of the sheet 10 based on first shape data indicating the shape of the first mark MA and the coordinates of the first detection point P1, the second detection point P2, the third detection point P3, and the fourth detection point P4, and corrects the cut position when cutting the cut area 40 based on the calculation results.

[0134] As described above, according to this embodiment, by simply scanning the first mark MA twice, it is possible to determine the coordinates of the first reference point CA, which indicates the position of the first mark MA, and the inclination of the sheet 10. Once the coordinates of the first reference point CA are determined, it is possible to determine the coordinate origin, provided that the relative position of the coordinate origin on the sheet 10 with respect to the first reference point CA is known, and the cutting position can be corrected based on the coordinate origin. Therefore, it is only necessary to scan at least one mark to correct the cutting position, and the number of scans per mark is small, so it is possible to easily determine the inclination of the sheet 10 and the coordinate origin on the sheet 10, which are necessary for cutting position correction.

[0135] In this embodiment, before the first and second scans are performed, a preliminary scan is performed in which the sensor 4 is moved relative to the sheet 10 in the CR direction. A first detection start point NA is determined based on the detection results of the first line A1 and the third line A3 obtained by the preliminary scan and the first shape data. The first and second scans are performed along scan lines L1 and L2, respectively, which pass through the first detection start point NA. When determining the first detection start point NA, the distance between the third detection point P3 and the fourth detection point P4 is determined so that it is equal to or greater than a predetermined distance.

[0136] This allows the scanning position to be set so that the distance between the two detection points on the third line A3 is not too small. If the distance between the two points is not too small, the inclination of the third line A3 can be determined with high accuracy. Therefore, the inclination of the sheet 10 and the origin position can be determined with high accuracy. In this way, if the positions of the detection points can be brought closer to the ideal positions by the preliminary scan, the inclination of the sheet 10 and the origin position can be determined with high accuracy even without using the high-precision sensor 4.

[0137] In this embodiment, before the first and second scans are performed, a preliminary scan is performed in which the sensor 4 is moved relative to the sheet 10 in the CR direction. A detection start point NA1 for the first scan is determined based on the detection results of the first line A1 and the third line A3 obtained by the preliminary scan and the first shape data. A first scan is performed along a scan line L1 that passes through the detection start point NA1 for the first scan, and a detection start point NA2 for the second scan is determined based on the first detection point P1 or the third detection point P3 detected by the first scan. A second scan is performed along a scan line L2 that passes through the detection start point NA2 for the second scan. When determining the detection start point NA2 for the second scan, the distance between the third detection point P3 and the fourth detection point P4 is determined to be equal to or greater than a predetermined distance.

[0138] This allows the scanning position to be set so that the distance between two points on the third line A3 is not too small. If the distance between the two points is not too small, the inclination of the third line A3 can be determined with high accuracy. Therefore, the inclination of the sheet 10 and the origin position can be determined with high accuracy. In particular, since the scanning line L2 of the second scan is determined using the results of the first scan, the detection start point NA2 for the second scan can be brought closer to the ideal position. Therefore, even if a high-precision sensor 4 is not used, the inclination of the sheet 10 and the origin position can be determined with high accuracy.

[0139] In this embodiment, the distance S0 between the first detection point P1 and the third detection point P3 detected by the first scan is checked to see if it is within a preset tolerance. If the distance S0 is outside the tolerance, the detection start point NA1 for the first scan is moved in the PF direction and the first scan is performed again. This allows the system to determine if the detection start point NA1 for the first scan has deviated significantly from its ideal position and correct the position of the detection start point NA1 for the first scan. This allows the positions of the detection points obtained by the first scan to approach their ideal positions. This prevents the distance between the two points on the third line A3 from becoming too small.

[0140] In this embodiment, the speed at which the sensor 4 is moved relative to the sheet 10 during the pre-scan is faster than the speed at which the sensor 4 is moved relative to the sheet 10 during the first and second scans. This shortens the time required for the pre-scan, and therefore the time required to detect the mark. Furthermore, because the pre-scan only needs to determine the detection start point, even if the detection accuracy decreases due to high-speed scanning, there is little effect on the detection accuracy of the first detection point P1, the second detection point P2, the third detection point P3, and the fourth detection point P4. Therefore, there is little effect on the detection accuracy of the tilt of the sheet 10 and the coordinate origin.

[0141] In this embodiment, the distance between two points indicating one edge and the other edge in the CR direction for each of the first line A1 and the third line A3 is detected as the line width based on the detection signal from the sensor 4 during the first scan. If the ratio d2 / d1 between the line width d1 of the first line A1 and the line width d2 of the third line A3 is outside a predetermined reference range, the second scan is not performed and detection of the first mark MA is halted. In this embodiment, the first mark MA includes three lines with different inclinations, so the line width ratio d2 / d1 varies depending on the inclination of the first mark MA. If the mark inclination is too large, even if the first and second scans are performed, the detection point may deviate too much from the ideal position, making it difficult to accurately calculate the inclination of the sheet 10 and the coordinate origin. Therefore, halting detection of the first mark MA based on the line width ratio d2 / d1 can avoid low-accuracy mark detection and, as a result, low-accuracy cut position correction.

[0142] In this embodiment, the first detection point P1 is the center point of a line connecting two points E1 and E2 that indicate one edge and the other edge in the CR direction on the first line A1 detected by the sensor 4. The second detection point P2 is the center point of a line connecting two points E3 and E4 that indicate one edge and the other edge in the PF direction on the second line A2 detected by the sensor 4. The third detection point P3 is the center point of a line connecting two points (not shown) that indicate one edge and the other edge in the CR direction on the third line A3 detected by the sensor 4. The fourth detection point P4 is the center point of a line connecting two points (not shown) that indicate one edge and the other edge in the PF direction on the third line A3 detected by the sensor 4. This allows points on the center line of each line that constitutes the mark to be detected as detection points, thereby enabling the inclination of the mark and the first reference point CA to be detected with high accuracy.

[0143] In this embodiment, the first mark MA is a right-angled triangle, with the first line A1 and the second line A2 intersecting at right angles. The PF direction is the conveyance direction of the sheet 10, and the sheet 10 is conveyed in the conveyance direction during the second scan. The CR direction is perpendicular to the conveyance direction, and during the first scan, the carriage 25 carrying the sensor 4 is moved relative to the sheet 10 in a direction perpendicular to the conveyance direction. When the sheet 10 is not tilted, the first line A1 is parallel to the conveyance direction, the second line A2 is perpendicular to the conveyance direction, and the third line A3 is inclined at 45° relative to the conveyance direction. This allows scanning in two directions using the sheet 10 conveyance mechanism 2 and the scanning mechanism 5, which scans in a direction perpendicular to the conveyance direction. Furthermore, by detecting two points on the third line A3, which is the hypotenuse, the inclination of the hypotenuse can be accurately determined. Therefore, the inclination of the sheet 10 can be determined easily and accurately.

[0144] In this embodiment, the first reference point CA is determined as the intersection of the first line A1 and the second line A2, so that the first reference point CA can be easily determined.

[0145] In this embodiment, a second mark MB indicating the cut area 40 is applied to the sheet 10. The second mark MB includes a fifth line B1, a sixth line B2, and a seventh line B3 that extend in different directions and do not intersect at the same point. A second detection start point NB is determined based on the first reference point CA, second shape data indicating the shape of the second mark MB, and data on the relative position of the second mark MB with respect to the first mark MA. A third scan is performed in which the sensor 4 is moved relative to the sheet 10 in the CR direction to detect a fifth detection point P5, which is the intersection of the scanning line L of the third scan and the fifth line B1, and a seventh detection point P7, which is the intersection of the scanning line L of the third scan and the seventh line B3. Furthermore, a fourth scan is performed by moving the sensor 4 relative to the sheet 10 in the PF direction to detect a sixth detection point P6, which is the intersection of the scanning line L of the fourth scan and the sixth line B2, and an eighth detection point P8, which is the intersection of the scanning line L of the fourth scan and the seventh line B3 and is different from the seventh detection point P7. Of the third and fourth scans, at least the third scan is performed along the scanning line L that passes through the second detection start point NB. A second reference point CB, which indicates the position of the second mark MB, is calculated based on the second shape data and the coordinates of the fifth detection point P5, the sixth detection point P6, the seventh detection point P7, and the eighth detection point P8. The inclination of the sheet 10 is then calculated based on the first reference point CA and the second reference point CB, and the cutting position is corrected based on the calculation result.

[0146] In this way, by determining the detection start point of the second mark MB using the detection result of the first mark MA, the detection start point of the second mark MB can be brought closer to the ideal position. This brings the seventh and eighth points closer to their ideal positions, preventing the distance between the two points on the seventh line B3 from becoming too small, and allowing the second reference point CB to be determined with high accuracy. Furthermore, by using the first reference point CA determined by detecting the first mark MA and the second reference point CB determined by detecting the second mark MB, the inclination of the sheet 10 and the coordinate origin on the sheet 10 can be determined with high accuracy.

[0147] In this embodiment, a second mark MB, a third mark MC, and a fourth mark MD, which surround the cut area 40 together with the first mark MA, are applied to the sheet 10. The first mark MA, the second mark MB, the third mark MC, and the fourth mark MD are all right-angled triangles, and the two orthogonal lines constituting the right-angled triangles extend in the CR and PF directions. A third scan in the CR direction and a fourth scan in the PF direction are performed on the second mark MB, and a second reference point CB indicating the position of the second mark MB is calculated based on the detection results of the third and fourth scans. At least one of the third and fourth scans is performed along a scan line L passing through a second detection start point NB determined using the first reference point CA and shape data of the second mark MB. A fifth scan in the CR direction and a sixth scan in the PF direction are performed on the third mark MC, and a third reference point CC indicating the position of the third mark MC is calculated based on the detection results of the fifth and sixth scans. At least one of the fifth and sixth scans is performed along a scan line L passing through a third detection start point NC determined using shape data of the second reference point CB and the third mark MC. A seventh scan in the CR direction and an eighth scan in the PF direction are performed on the fourth mark MD, and a fourth reference point CD indicating the position of the fourth mark MD is calculated based on the detection results of the seventh and eighth scans. At least one of the seventh and eighth scans is performed along a scan line L passing through a fourth detection start point ND determined using shape data of the third reference point CC and the fourth mark MD. The position of the cut area 40 and the inclination of the sheet 10 are calculated based on the first reference point CA, the second reference point CB, the third reference point CC, and the fourth reference point CD, and the cut position is corrected based on the calculation results.

[0148] In this way, when detecting the second mark MB, the third mark MC, and the fourth mark MD, the detection start point is determined using the detection result of the most recently detected mark, allowing the detection start point to approach the ideal position. This allows the detection accuracy of each mark to be sequentially improved, making it possible to accurately determine the second reference point CB, the third reference point CC, and the fourth reference point CD. Then, using these four reference points, the inclination of the sheet 10 and the coordinate origin on the sheet 10 can be determined with greater accuracy.

[0149] (Other embodiments) (1) In the above embodiment, scanning in the CR direction is performed first for each mark, and then scanning in the PF direction. However, scanning in the PF direction may be performed first, and then scanning in the CR direction.

[0150] (2) The arrangement of the marks is not limited to the arrangement shown in FIG. 2. FIG. 13 is an explanatory diagram showing another example of the arrangement of the marks. As shown in the upper diagram of FIG. 13, the marks MA1, MB1, MC1, and MD1, which are shaped like right-angled isosceles triangles, are arranged so that the intersection of two orthogonal sides, rather than the hypotenuse, faces the corner of the cut area 40. In this case, as shown in the lower diagram of FIG. 13, the hypotenuse of each mark is arranged on the outer periphery. Therefore, when scanning each mark once in the CR direction and once in the PF direction, the detection start point, which is the start or end point of the scanning, can be set on the outer periphery of the hypotenuse.

[0151] (3) Figure 14 is an explanatory diagram showing an embodiment in which the number of marks is changed. As shown in Figure 14, the number of marks can be set to 2, 3, 4, or 8. When correcting the cutting position, it is possible to correct the cutting position by detecting only some of these marks, or to detect all of them.

[0152] (4) The mark is not limited to a right-angled isosceles triangle. For example, the mark may have three straight lines that intersect each other but do not intersect at a single point. Furthermore, the mark may have a shape in which one of the three straight lines intersects with the scanning line in the CR direction, one intersects with the scanning line in the PF direction, and the last intersects with both the scanning line in the CR direction and the scanning line in the PF direction. For example, the mark may be an arbitrary right-angled triangle.

[0153] (Other Embodiments) Next, a print position correction method for correcting the print position when printing on a sheet 10A and a printing apparatus 1A will be described with reference to Figures 15 and 16. Figure 15 is an explanatory diagram showing the configuration of the printing apparatus 1A. Figure 16 is an explanatory diagram showing an example of the layout of a print area 40A and marks on the sheet 10A. Below, components that are the same as those in the above embodiment are assigned the same reference numerals, and descriptions thereof will be omitted.

[0154] As shown in Figure 16, a print area 40A is set on the sheet 10A. Four marks, a first mark MA, a second mark MB, a third mark MC, and a fourth mark MD, are marked outside the print area 40A. The sheet 10A may be any type as long as it is possible to print on its surface. For example, the sheet 10A may have the same configuration as the sheet 10 described above, or it may have a different configuration.

[0155] As shown in FIG. 15 , the printing apparatus 1A includes a transport mechanism 2 that transports a sheet 10A in the PF direction (second scanning direction), a scanning mechanism 5 that moves a carriage 25, on which a print head 3A and a sensor 4 are mounted, in a first scanning direction (CR direction) that intersects with the PF direction, and a control unit 6 that controls the transport mechanism 2 and the scanning mechanism 5. The control unit 6 includes a mark detection unit 61 and a print position correction unit 62A. The print position correction unit 62A corrects the processing position to eliminate any misalignment between the set processing area (print area 40A) and the actual processing position (printing position). Therefore, the print position correction unit 62A is a sheet processing position correction unit.

[0156] A sheet 10A is set in the printing device 1A. Before starting a printing operation, the printing device 1A detects marks on the sheet 10A and calculates the position of the coordinate origin of the sheet 10A and the inclination of the sheet 10A based on the detection results. Then, assuming that the position of the print area 40A relative to the coordinate origin of the sheet 10A is known, a print position correction process is performed to correct the print position of the print head 3A using the coordinate origin and the sheet inclination calculated from the mark detection results. This eliminates any misalignment between the position printed by the print head 3A and the set print area 40A, allowing for accurate printing. The details of the print position correction process are the same as the cut position correction process described in the above embodiment.

[0157] As described above, the print position correction method of this embodiment uses the sensor 4 to detect a first mark MA indicating the print area 40A on the sheet 10 and correct the print position when cutting the print area 40A. The first mark MA includes a first line A1, a second line A2, and a third line A3 that extend in different directions and do not intersect at the same point. A first scan is performed by moving the sensor 4 relative to the sheet 10 in the CR direction to detect a first detection point P1, which is the intersection of the scanning line L1 of the first scan and the first line A1, and a third detection point P3, which is the intersection of the scanning line L1 of the first scan and the third line A3. A second scan is performed by moving the sensor 4 relative to the sheet 10 in the PF direction, which intersects with the CR direction, to detect a second detection point P2, which is the intersection of the scanning line L2 of the second scan and the second line A2, and a fourth detection point P4, which is the intersection of the scanning line L2 of the second scan and the third line A3 but is different from the third detection point P3. Based on the first shape data indicating the shape of the first mark MA and the coordinates of the first detection point P1, the second detection point P2, the third detection point P3, and the fourth detection point P4, the first reference point CA indicating the position of the first mark MA and the inclination of the sheet 10 are calculated, and the printing position is corrected based on the calculation results.

[0158] The printing device 1A of this embodiment also includes a transport mechanism 2 that transports a sheet 10 bearing a first mark MA indicating a printing area 40A, a print head 3A for printing on the sheet 10, a scanning mechanism 5 that moves a sensor 4 for detecting the first mark MA in a scanning direction that intersects the transport direction of the transport mechanism 2, and a control unit 6 that controls the transport mechanism 2 and the scanning mechanism 5 and to which a detection signal from the sensor 4 is input. The first mark MA includes a first line A1, a second line A2, and a third line A3 that extend in directions that intersect with each other but do not intersect at the same point. The control unit 6 performs a first scan by driving the scanning mechanism 5 to move the sensor 4 in the scanning direction, and a second scan by driving the transport mechanism 2 to transport the sheet 10. The control unit 6 further includes a mark detection unit 61 that detects, from the output of the sensor 4 in the first scan, a first detection point P1 which is the intersection of the scanning line L1 of the first scan and the first line A1, and a third detection point P3 which is the intersection of the scanning line L1 of the first scan and the third line A3, and detects, from the output of the sensor 4 in the second scan, a second detection point P2 which is the intersection of the scanning line L2 of the second scan and the second line A2, and a fourth detection point P4 which is the intersection of the scanning line L2 of the second scan and the third line A3 and is different from the third detection point P3. The control unit 6 also includes a print position correction unit 62A that calculates a first reference point CA indicating the position of the first mark MA and the inclination of the sheet 10 based on first shape data indicating the shape of the first mark MA and the coordinates of the first detection point P1, the second detection point P2, the third detection point P3, and the fourth detection point P4, and corrects the print position when cutting the print area 40A based on the calculation results.

[0159] The printing position correction method and printing device 1A of this embodiment can perform all of the detailed processing contents described in the cutting position correction method and cutting device 1 above.

[0160] The printing device 1A of this embodiment may be set with a sheet 10A that has already been printed in the printing area 40A or another area. In this case, the printing device 1A performs additional printing in the printing area 40A. This allows additional printing to be accurately aligned with the previously printed image or text. It is also possible to print with clear ink or the like on top of previously printed images or text.

[0161] Alternatively, instead of a printed sheet 10A, a cut sheet 10A that has been cut along the outline of the print area 40A may be set in the printing device 1A. Alternatively, an area including a margin around the print area 40A may be set as the cut area, and a cut sheet that has been cut along the outline of the cut area may be set in the printing device 1A. In this case, for example, a sheet 10A in which only the film 12 has been cut without cutting the backing paper 11 is set in the printing device 1A. The printing device 1A prints on the print area 40A of the cut sheet 10A. This allows printing to be accurately aligned with the cut area.

[0162] FIG. 17 is an explanatory diagram showing the configuration of a sheet processing apparatus 1B with printing and cutting functions. As shown in FIG. 17, the sheet processing apparatus 1B has a carriage 25 mounted with a cutter 3, a print head 3A, and a sensor 4. The control unit 6 includes a mark detection unit 61 and a sheet processing position correction unit 62B. The sheet processing position correction unit 62B includes a cut position correction unit 62 and a print position correction unit 62A. The sheet processing position correction unit 62B corrects the processing position to eliminate any deviation between the set processing area and the actual processing position. Specifically, it performs both the print position correction process in the printing apparatus 1A and the cut position correction process in the cutting apparatus 1. This allows printing and cutting to be performed according to the set area. It also allows cutting to be performed according to the printed area and printing to be performed in a position aligned with the cut area.

[0163] FIG. 18 is an explanatory diagram showing another configuration of a sheet processing apparatus 1C with printing and cutting functions. The sheet processing apparatus 1C is an apparatus that prints and cuts a sheet 10 placed on the surface of a mounting table 27. The sheet processing apparatus 1C includes the mounting table 27, a carriage 25 on which a cutter 3, a print head 3A, and a sensor 4 are mounted, a scanning mechanism 5 that moves the carriage 25 in the CR direction, and a second scanning mechanism 29 that moves the carriage 25 in the PF direction. The second scanning mechanism 29 moves the cutter 3, the print head 3A, and the sensor 4 in the PF direction relative to the sheet 10. The second scanning mechanism 29 includes, for example, a pair of moving members 28 fixed to both ends of a carriage shaft 26, a pair of guide mechanisms for moving the pair of moving members 28 in the PF direction, and a drive force transmission mechanism and drive source (not shown) for transmitting drive force to the moving members 28.

[0164] 18, the sheet processing apparatus 1C can print and cut long sheets by providing a sheet supply mechanism (not shown) that transports a sheet in the PF direction and supplies it to the mounting section 27, in addition to mounting a single sheet 10 on the mounting section 27. In this case, after printing and cutting on the sheet portion mounted on the mounting section 27 is completed, the sheet is fed in the PF direction shown in FIG. 18, and an unused sheet portion is placed on the mounting section 27 for the next printing and cutting.

[0165] The sheet processing apparatus 1C prints and cuts the sheet 10 by moving the carriage 25 in the PF and CR directions without moving the sheet 10. The control unit 6 of the sheet processing apparatus 1C includes a mark detection unit 61 and a sheet processing position correction unit 62B, similar to the configuration shown in FIG. 17 . The sheet processing position correction unit 62B includes a cutting position correction unit 62 and a printing position correction unit 62A. This allows both the printing position correction process of the printing apparatus 1A and the cutting position correction process of the cutting apparatus 1 to be performed. Therefore, printing and cutting can be performed according to a set area. Furthermore, cutting can be performed according to the printed area, and printing can be performed in a position aligned with the cut area.

[0166] In this way, the second scanning mechanism in the present invention is not limited to the transport mechanism 2 that transports the sheet 10, but may be a second scanning mechanism 29 that moves the carriage 25 on which the sensor 4 is mounted in the PF direction. Similarly, the first scanning mechanism in the present invention is not limited to the scanning mechanism 5 that moves the carriage 25 on which the sensor 4 is mounted in the CR direction, but may be a mechanism that moves the sheet 10 in the CR direction.

[0167] FIG. 19 is an explanatory diagram of a sheet 10B with a used processing area. The sheet 10B has two processing areas 41 and 42. The processing area 41 has been used. For example, at least one of printing and cutting has already been performed on the processing area 41. The processing area 42 is unused. Four marks, a first mark MA, a second mark MB, a third mark MC, and a fourth mark MD, are marked on the outside of the two processing areas 41 and 42. If this sheet 10B is set in the cutting device 1, it can be cut to fit into the unused processing area 42. Alternatively, if this sheet 10B is set in the printing device 1A, it can be printed to fit into the unused processing area 42. Furthermore, if this sheet 10B is set in the sheet processing device 1B, it can be both printed and cut to fit into the unused processing area 42.

Claims

1. A sheet processing position correction method for detecting a first mark indicating a processing area of ​​a sheet with a sensor and correcting a processing position when performing at least one of printing and cutting on the processing area, wherein the first mark has a first line, a second line, and a third line that extend in different directions and do not intersect at the same point; a first scan is performed to move the sensor relatively to the sheet in a first scanning direction, and a first detection point is detected as an intersection of the scanning line of the first scan and the first line, and a third detection point is detected as an intersection of the scanning line of the first scan and the third line; a second scan is performed to move the sensor relatively to the sheet in a second scanning direction that intersects with the first scanning direction, and a second detection point is detected as an intersection of the scanning line of the second scan and the second line, and a fourth detection point is detected as an intersection of the scanning line of the second scan and the third line, which is different from the third detection point; A sheet processing position correction method characterized by calculating a first reference point indicating the position of the first mark and the inclination of the sheet based on first shape data indicating the shape of the first mark and the coordinates of the first detection point, the second detection point, the third detection point, and the fourth detection point, and correcting the processing position based on the calculation results.

2. A sheet processing position correction method as described in claim 1, characterized in that before performing the first scan and the second scan, a preliminary scan is performed in which the sensor is moved relative to the sheet in the first scan direction, a first detection start point is determined based on the detection results of the first line and the third line by the preliminary scan and the first shape data, the first scan and the second scan are each performed along a scanning line that passes through the first detection start point, and when determining the first detection start point, the distance between the third detection point and the fourth detection point is determined to be equal to or greater than a predetermined distance.

3. A sheet processing position correction method as described in claim 1, characterized in that before performing the first scan and the second scan, a preliminary scan is performed to move the sensor relative to the sheet in the first scan direction, a detection start point for the first scan is determined based on the detection results of the first line and the third line by the preliminary scan and the first shape data, and the first scan is performed along a scan line that passes through the detection start point for the first scan, a detection start point for the second scan is determined based on the first detection point or the third detection point detected by the first scan, and the second scan is performed along a scan line that passes through the detection start point for the second scan, and when determining the detection start point for the second scan, the distance between the third detection point and the fourth detection point is determined to be equal to or greater than a predetermined distance.

4. A sheet processing position correction method as described in claim 3, characterized in that it is confirmed whether the distance between the first detection point and the third detection point detected by the first scan is within a predetermined tolerance range, and if the distance is outside the tolerance range, the detection start point for the first scan is moved in the second scan direction and the first scan is performed again.

5. A sheet processing position correction method as described in claim 2 or 3, characterized in that the speed at which the sensor is moved relative to the sheet during the preliminary scan is faster than the speed at which the sensor is moved relative to the sheet during the first scan and the second scan.

6. A sheet processing position correction method as described in claim 1, characterized in that, based on the detection signal of the sensor in the first scan, the distance between two points indicating one edge and the other edge in the first scan direction is detected as the line width for each of the first line and the third line, and if the ratio between the line width of the first line and the line width of the third line is outside a predetermined reference range, the second scan is not performed and detection of the first mark is discontinued.

7. A sheet processing position correction method as described in claim 1, characterized in that the first detection point is the center point of a straight line connecting two points indicating one edge and the other edge in the first scanning direction on the first line detected by the sensor, the second detection point is the center point of a straight line connecting two points indicating one edge and the other edge in the second scanning direction on the second line detected by the sensor, the third detection point is the center point of a straight line connecting two points indicating one edge and the other edge in the first scanning direction on the third line detected by the sensor, and the fourth detection point is the center point of a straight line connecting two points indicating one edge and the other edge in the second scanning direction on the third line detected by the sensor.

8. The sheet processing position correcting method according to claim 1, wherein the first mark is a right-angled triangle, and the first line and the second line are perpendicular to each other.

9. A sheet processing position correction method as described in claim 8, characterized in that: the second scanning direction is the transport direction of the sheet, and when performing the second scan, the sheet is transported in the transport direction; the first scanning direction is a direction perpendicular to the transport direction, and when performing the first scan, the sensor is moved relative to the sheet in a direction perpendicular to the transport direction; and when the sheet is not tilted, the first line is parallel to the transport direction, the second line is perpendicular to the transport direction, and the third line is inclined at 45° with respect to the transport direction.

10. The sheet processing position correcting method according to claim 8, wherein the first reference point is an intersection of the first line and the second line.

11. When a second mark indicating the processing area is affixed to the sheet, and the second mark has fifth, sixth, and seventh lines that extend in different directions from one another and do not intersect at the same point, a second detection start point is determined based on the first reference point, second shape data indicating the shape of the second mark, and data on the relative position of the second mark with respect to the first mark; a third scan is performed in which the sensor is moved relatively to the sheet in the first scanning direction, and a fifth detection point is detected as an intersection point between the scanning line of the third scan and the fifth line, and a seventh detection point is detected as an intersection point between the scanning line of the third scan and the seventh line; a fourth scan is performed in which the sensor is moved relatively to the sheet in the second scanning direction, and a sixth detection point is detected as an intersection point between the scanning line of the fourth scan and the sixth line, and an eighth detection point is an intersection point between the scanning line of the fourth scan and the seventh line and is different from the seventh detection point; of the third and fourth scans, at least the third scan is performed along a scan line that passes through the second detection start point; The sheet processing position correction method according to claim 2 or 3, characterized in that a second reference point indicating the position of the second mark is calculated based on the second shape data and the coordinates of the fifth detection point, the sixth detection point, the seventh detection point, and the eighth detection point, the inclination of the sheet is calculated based on the first reference point and the second reference point, and the processing position is corrected based on the calculation result.

12. A second mark, a third mark, and a fourth mark which surround the processing area together with the first mark are affixed to the sheet, and the first mark, the second mark, the third mark, and the fourth mark are all right-angled triangles, and two orthogonal lines which form the right-angled triangle extend in the first scanning direction and the second scanning direction; a third scan in the first scanning direction and a fourth scan in the second scanning direction are performed on the second mark, and a second reference point indicating the position of the second mark is calculated based on the detection results of the third scan and the fourth scan; and at least one of the third scan and the fourth scan is performed along a scan line which passes through the first reference point and a second detection start point determined using shape data of the second mark; 4. The sheet processing position correcting method according to claim 2, further comprising: performing a fifth scan in the first scanning direction and a sixth scan in the second scanning direction on the third mark; calculating a third reference point indicating the position of the third mark based on detection results from the fifth scan and the sixth scan, wherein at least one of the fifth scan and the sixth scan is performed along a scan line passing through a third detection start point determined using the second reference point and shape data of the third mark; performing a seventh scan in the first scanning direction and an eighth scan in the second scanning direction on the fourth mark; calculating a fourth reference point indicating the position of the fourth mark based on detection results from the seventh scan and the eighth scan, wherein at least one of the seventh scan and the eighth scan is performed along a scan line passing through a fourth detection start point determined using the third reference point and the shape data of the fourth mark; and calculating a position of the processing area and a tilt of the sheet based on the first reference point, the second reference point, the third reference point, and the fourth reference point, and correcting the processing position based on the calculation results.

13. A sheet processing apparatus having at least one of a cutter for cutting a sheet and a print head for printing on the sheet, a sensor for detecting a first mark indicating a processing area of ​​the sheet, a first scanning mechanism for moving the sensor relative to the sheet in a first scanning direction, a second scanning mechanism for moving the sensor relative to the sheet in a second scanning direction intersecting the first scanning direction, and a control unit that controls the first scanning mechanism and the second scanning mechanism and receives a detection signal from the sensor, wherein the first mark comprises a first line, a second line, and a third line that extend in directions that intersect each other and do not intersect at the same point, and the control unit a mark detection unit that performs a first scan by driving the first scanning mechanism to move the sensor relatively to the sheet in the first scanning direction, and a second scan by driving the second scanning mechanism to move the sensor relatively to the sheet in the second scanning direction, and detects, from an output of the sensor in the first scan, a first detection point that is an intersection of a scan line of the first scan and the first line, and a third detection point that is an intersection of the scan line of the first scan and the third line, and detects, from an output of the sensor in the second scan, a second detection point that is an intersection of the scan line of the second scan and the second line, and a fourth detection point that is an intersection of the scan line of the second scan and the third line and is different from the third detection point; A sheet processing apparatus characterized by comprising: a sheet processing position correction unit that calculates a first reference point indicating the position of the first mark and the inclination of the sheet based on first shape data indicating the shape of the first mark and the coordinates of the first detection point, the second detection point, the third detection point, and the fourth detection point, and corrects a processing position when performing at least one of printing and cutting on the processing area based on the calculation results.

14. The sheet processing apparatus described in claim 13, characterized in that the mark detection unit performs a preliminary scan by driving the first scanning mechanism to move the sensor in the first scanning direction, and is equipped with a detection start point determination unit that determines a first detection start point based on the detection results of the first line and the third line by the preliminary scan and the first shape data, the mark detection unit performs each of the first scan and the second scan along a scanning line that passes through the first detection start point, and the detection start point determination unit determines the first detection start point so that the distance between the third detection point and the fourth detection point is equal to or greater than a predetermined distance.

15. The sheet processing apparatus described in claim 13, characterized in that the mark detection unit performs a preliminary scan by driving the first scanning mechanism to move the sensor in the first scanning direction, and is equipped with a detection start point determination unit that determines a detection start point for the first scan based on the detection results of the first line and the third line by the preliminary scan and the first shape data, the mark detection unit performs the first scan along a scanning line that passes through the detection start point for the first scan, the detection start point determination unit determines a detection start point for the second scan based on the first detection point or the third detection point detected by the first scan, the mark detection unit performs the second scan along a scanning line that passes through the detection start point for the second scan, and when determining the detection start point for the first scan and the detection start point for the second scan, the detection start point determination unit determines them so that the distance between the third detection point and the fourth detection point is equal to or greater than a predetermined distance.

16. The sheet processing apparatus described in claim 15, characterized in that the detection start point determination unit checks whether the distance between the first detection point and the third detection point detected by the first scan is within a predetermined tolerance range, and if the distance is outside the tolerance range, moves the detection start point for the first scan in the second scan direction, and the mark detection unit performs the first scan again along a scan line that passes through the detection start point for the first scan after the movement.

17. A sheet processing apparatus as described in claim 14 or 15, characterized in that the detection start point determination unit makes the speed at which the sensor moves relative to the sheet during the preliminary scan faster than the speed at which the sensor moves relative to the sheet during the first scan and the second scan.

18. The sheet processing apparatus described in claim 13, characterized in that the mark detection unit calculates the distance between two points indicating one edge and the other edge in the first scanning direction for each of the first line and the third line based on the detection signal of the sensor in the first scanning, as the line width, and if the ratio between the line width of the first line and the line width of the third line is outside a predetermined reference range, stops detecting the first mark without performing the second scanning.

19. The sheet processing apparatus described in claim 13, characterized in that the mark detection unit calculates, as the first detection point, the center point of a straight line connecting two points indicating one edge and the other edge in the first scanning direction on the first line detected by the sensor, as the first detection point, calculates, as the second detection point, the center point of a straight line connecting two points indicating one edge and the other edge in the second scanning direction on the second line detected by the sensor, as the third detection point, calculates, as the third detection point, the center point of a straight line connecting two points indicating one edge and the other edge in the first scanning direction on the third line detected by the sensor, and calculates, as the fourth detection point, the center point of a straight line connecting two points indicating one edge and the other edge in the second scanning direction on the third line detected by the sensor.

20. A sheet processing apparatus according to claim 13, wherein the second scanning mechanism is a transport mechanism that transports the sheet, the second scanning direction is the transport direction of the sheet, and the first scanning direction is perpendicular to the transport direction.

21. A sheet processing apparatus as described in claim 20, characterized in that the first mark is a right-angled triangle, and when the sheet is not tilted, the first line is parallel to the conveying direction, the second line is perpendicular to the conveying direction, and the third line is inclined at 45 degrees with respect to the conveying direction.

22. When a second mark indicating the processing area is affixed to the sheet, and the second mark has fifth, sixth, and seventh lines that extend in different directions from one another and do not intersect at the same point, the detection start point determination unit determines a second detection start point based on the first reference point, second shape data indicating the shape of the second mark, and data on the relative position of the second mark with respect to the first mark, and the mark detection unit performs a third scan by moving the sensor relatively to the sheet in the first scanning direction, and detects a fifth detection point that is an intersection of the scanning line of the third scan and the fifth line, and a seventh detection point that is an intersection of the scanning line of the third scan and the seventh line, and further performs a fourth scan by moving the sensor relatively to the sheet in the second scanning direction, and detects a sixth detection point that is an intersection of the scanning line of the fourth scan and the sixth line, and an eighth detection point that is an intersection of the scanning line of the fourth scan and the seventh line and is different from the seventh detection point, The sheet processing apparatus according to claim 15 or 16, characterized in that of the third scan and the fourth scan, at least the third scan is performed along a scanning line that passes through the second detection start point, and the sheet processing position correction unit calculates a second reference point indicating the position of the second mark based on the second shape data and the coordinates of the fifth detection point, the sixth detection point, the seventh detection point, and the eighth detection point, calculates the inclination of the sheet based on the first reference point and the second reference point, and corrects the processing position based on the calculation result.

23. When a second mark, a third mark, and a fourth mark which surround the processing area together with the first mark are affixed to the sheet, and the first mark, the second mark, the third mark, and the fourth mark are all right-angled triangles, and two orthogonal lines constituting the right-angled triangle extend in the first scanning direction and the second scanning direction, the mark detection unit performs a third scan in the first scanning direction and a fourth scan in the second scanning direction on the second mark, and at least one of the third scan and the fourth scan is performed along a scan line which passes through a second detection start point determined using the first reference point and shape data of the second mark, and the sheet processing position correction unit calculates a second reference point which indicates the position of the second mark based on the detection results of the third scan and the fourth scan, and the mark detection unit a fifth scan in the first scanning direction and a sixth scan in the second scanning direction are performed on the third mark, and at least one of the fifth scan and the sixth scan is performed along a scan line that passes through a third detection start point determined using the second reference point and shape data of the third mark; the sheet processing position correction unit calculates a third reference point that indicates the position of the third mark based on detection results from the fifth scan and the sixth scan; the mark detection unit performs a seventh scan in the first scanning direction and an eighth scan in the second scanning direction on the fourth mark, and at least one of the seventh scan and the eighth scan is performed along a scan line that passes through a fourth detection start point determined using the third reference point and shape data of the fourth mark; and the sheet processing position correction unit calculates a fourth reference point that indicates the position of the fourth mark based on detection results from the seventh scan and the eighth scan.

16. A sheet processing apparatus according to claim 14, wherein the position of the processing area and the inclination of the sheet are calculated based on the first reference point, the second reference point, the third reference point, and the fourth reference point, and the processing position is corrected based on the calculation result.

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