JP2009241401A - Printer, test pattern forming method in printer, and test pattern forming program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To form a test pattern high in visibility. <P>SOLUTION: A controller ejects ink from three ink ejection openings of first to third ejection openings and controls a length of a straight line drawn by the ink ejected from the second ejection opening shorter than a length of a straight line drawn by the ink ejected from the first and third ejection openings. The first and second ejection openings belong to two rows which are separated most in a lateral direction among 16 rows formed in an ejection opening formation region by many ink ejection openings to extend in a longitudinal direction. The third ejection opening belongs to a row located between the two rows to which the first and second ejection openings belong, having a projection point at a position symmetric to a projection point of the first ejection opening with respect to a projection point of the second ejection opening on a virtual straight line. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a printer that discharges liquid from a liquid discharge head to form a test pattern, a test pattern forming method in the printer, and a program for forming a test pattern.

  As an ink jet head provided in a line type ink jet printer, there is known an ink jet head in which a plurality of ejection openings for ejecting ink are arranged in a matrix on an ejection surface. More specifically, in such an inkjet head, a plurality of parallel rows in which the discharge ports are arranged in one direction are formed, and all the discharge ports constituting the plurality of rows are virtual straight lines in one direction. The discharge ports are arranged so that the projection points of the discharge ports are arranged at equal intervals on the virtual straight line when projected from an orthogonal direction orthogonal to one direction in the plane including the discharge surface (for example, Patent Documents) 1).

Further, Patent Document 2 discloses a test pattern formed by ejecting ink from a plurality of nozzles of a head unit on a recording sheet being conveyed. That is, this test pattern is composed of a plurality of straight lines extending along the recording sheet conveyance direction.
JP 2007-044967 A Japanese Patent Laying-Open No. 2006-123291 (FIG. 7)

  Consider a case where a test pattern as disclosed in Patent Document 2 is formed in an inkjet head in which a plurality of ejection openings are arranged in a matrix as described above. Here, in such a test pattern, as the distance in the orthogonal direction between the two ejection openings that draws a straight line increases, the deviation between the sub-scanning direction, which is the paper transport direction, and the orthogonal direction becomes smaller. The amount of change in the distance between the two straight lines drawn at the discharge port increases. Therefore, for example, the discharge port as a reference, the discharge port having a relatively large separation distance in the direction orthogonal to the reference discharge port, and the discharge port having a relatively short separation distance in the direction orthogonal to the reference discharge port. A test pattern consisting of three straight lines drawn with ink from two ejection openings is formed, and the size of the deviation between the sub-scanning direction and the orthogonal direction is detected by observing the positional relationship between these three straight lines. can do.

  However, when observing a straight line of the test pattern as described above, it is difficult to associate which straight line is drawn with ink ejected from which ejection port.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a printer capable of forming a test pattern with high visibility, a test pattern forming method in the printer, and a test pattern forming program.

  In the printer of the present invention, a plurality of parallel rows in which the discharge ports are arranged in one direction are formed on the discharge surface on which the discharge ports for discharging the liquid are formed, and all of the plurality of rows are formed. The projection points of the discharge ports are equally spaced on the virtual straight line when projected from the orthogonal direction orthogonal to the one direction within a plane including the discharge surface on the virtual straight line along the one direction. A liquid discharge head in which a plurality of the discharge ports are arranged so as to line up with each other. Further, the first discharge port and the second discharge port, which are the discharge ports belonging to the two non-adjacent rows, respectively, belong to the row located between the two non-adjacent rows, and are on the virtual straight line. The three discharge ports, the third discharge port and the third discharge port having the projection point at a position symmetrical to the projection point of the first discharge port with respect to the projection point of the second discharge port, are used. Discharge control for controlling the liquid to be discharged such that the line drawn by the liquid discharged from the two discharge ports differs from the line drawn by the liquid discharged from the first and third discharge ports. Means.

  In the test pattern forming method of the present invention, a plurality of parallel rows in which the discharge ports are arranged along one direction are formed on the discharge surface on which the discharge ports for discharging the liquid are formed, The projection points of the discharge ports when the projections of all the discharge ports constituting the row are projected from the orthogonal direction perpendicular to the one direction within a plane including the discharge surface on a virtual straight line along the one direction are This is a test pattern forming method for forming a test pattern in a printer including a liquid discharge head in which a plurality of the discharge ports are arranged so as to be arranged at equal intervals on a virtual straight line. And the first discharge port and the second discharge port, which are the discharge ports belonging to the two non-adjacent rows, respectively, belong to the row located between the two non-adjacent rows, and on the virtual straight line The three discharge ports, the third discharge port, which is the discharge port having the projection point at a position symmetrical to the projection point of the first discharge port with respect to the projection point of the second discharge port, are used. The test pattern is formed by discharging the liquid such that the line drawn by the liquid discharged from the two discharge ports differs from the line drawn by the liquid discharged from the first and third discharge ports.

  Furthermore, the test pattern forming program of the present invention is configured such that a plurality of parallel rows in which the discharge ports are arranged along one direction are formed on the discharge surface on which the discharge ports for discharging the liquid are formed, When all the discharge ports constituting a row are projected on a virtual straight line along the one direction from a direction orthogonal to the one direction within a plane including the discharge surface, the projection point of the discharge port is the virtual point. A test pattern forming program for causing a computer to execute test pattern formation in a printer including a liquid discharge head in which the plurality of discharge ports are arranged at equal intervals on a straight line. And the first discharge port and the second discharge port, which are the discharge ports belonging to the two non-adjacent rows, respectively, belong to the row located between the two non-adjacent rows, and on the virtual straight line The three discharge ports, the third discharge port, which is the discharge port having the projection point at a position symmetrical to the projection point of the first discharge port with respect to the projection point of the second discharge port, are used. The computer causes the computer to execute a process of discharging the liquid so that the line drawn by the liquid discharged from the two discharge ports differs from the line drawn by the liquid discharged from the first and third discharge ports.

  According to these configurations, the line drawn by the liquid ejected from the second ejection port whose projection point is centered on the virtual straight line among the first ejection port, the second ejection port, and the third ejection port. It can be easily identified. Therefore, the visibility of the test pattern to be formed is improved.

  In the printer according to the aspect of the invention, the discharge control unit may determine whether at least one of a length, a thickness, and a line type of a line drawn by the liquid discharged from the second discharge port is the first and third discharges. You may control so that it may differ from the line drawn with the liquid discharged from the exit. According to this configuration, the mode of the line drawn by the liquid discharged from the second discharge port and the mode of the line drawn by the liquid discharged from the first and third discharge ports can be easily changed.

  In the printer according to the aspect of the invention, the ejection control unit ejects liquid from the first to third ejection ports, so that the sub-scanning direction, which is the direction of relative movement of the liquid ejection head and the recording medium, and the orthogonal direction. A test pattern may be formed for inspecting the deviation.

  The larger the interval between the two ejection ports in the orthogonal direction, the larger the amount of change in the distance between the two straight lines drawn by the liquid ejected from the two ejection ports with respect to the deviation between the sub-scanning direction and the orthogonal direction. . Here, since the third discharge port is located between two non-adjacent rows to which the first and second discharge ports belong, the interval between the first discharge port and the second discharge port in the orthogonal direction is It is longer than the interval between the first discharge port and the third discharge port. Therefore, the amount of change in the distance between the two straight lines drawn by the first and second discharge ports with respect to the shift between the sub-scanning direction and the orthogonal direction is the two of the two drawn by the first and third discharge ports. It becomes larger than the change amount of the distance between the straight lines. Therefore, according to the said structure, the shift | offset | difference of a subscanning direction and an orthogonal direction can be test | inspected easily by observing the positional relationship of the three straight lines drawn by the 1st-3rd discharge outlet.

  In the printer according to the aspect of the invention, the two rows to which the first and second ejection ports belong may be the ones farthest in the orthogonal direction. According to this configuration, the amount of change in the distance between the two straight lines drawn by the first and second ejection ports with respect to the deviation between the sub-scanning direction and the orthogonal direction is the largest. Therefore, the deviation between the sub-scanning direction and the orthogonal direction can be inspected with high accuracy.

  In the printer of the present invention, it is preferable that the projection points of the first to third ejection ports are adjacent to each other on a virtual straight line. According to this configuration, the three lines drawn by the liquid ejected from the first to third ejection ports are formed close to each other, so that the positional relationship between the three straight lines can be easily observed.

  In the printer according to the aspect of the invention, the discharge control unit may perform the sub-operation in which three lines drawn by the liquid discharged from the first to third discharge ports are directions of relative movement of the liquid discharge head and the recording medium. You may control so that two or more may be formed in the direction orthogonal to a direction. According to this configuration, a plurality of three lines are drawn by different discharge ports. Accordingly, it is possible to determine whether the deviation in the positional relationship between the three lines is caused by the malfunction of the ejection port itself that ejected the liquid or the deviation between the sub-scanning direction and the orthogonal direction.

  In the printer according to the aspect of the invention, the ejection control unit may perform sub-scanning in which three lines drawn by the liquid ejected from the first to third ejection ports are directions of relative movement of the liquid ejection head and the recording medium. You may control so that two or more may be formed in a direction. For example, in a printer that ejects liquid from a liquid ejection head onto a recording medium that is conveyed in the sub-scanning direction, the conveyance of the recording medium may be temporarily disturbed. According to the above configuration, even in such a case, it is possible to detect a deviation between the sub-scanning direction and the orthogonal direction with high reliability.

  As described above, in the printer of the present invention, the test pattern forming method in the printer, and the test pattern forming program, the projection point of the first discharge port, the second discharge port, and the third discharge port is on a virtual straight line. The line drawn by the liquid ejected from the second ejection port located at the center can be easily identified. Therefore, the visibility of the test pattern to be formed is improved.

  A preferred embodiment of the present invention will be described below with reference to the drawings.

  FIG. 1 is a schematic side view showing an overall configuration of a printer according to an embodiment of the present invention. FIG. 2 is a schematic plan view of a main part of the printer shown in FIG. As shown in FIGS. 1 and 2, the printer 1 is a color inkjet printer having a plurality of inkjet heads 2. A transport mechanism 12 for transporting paper is disposed below the ink jet head 2, and the paper fed from the paper feed tray 11 by the pickup roller 11 a is directed from the left to the right in FIG. 1 (arrows). A direction indicated by A: hereinafter referred to as “conveying direction”).

  The transport mechanism 12 includes two belt rollers 16 and 17 and an endless transport belt 18 spanned between the belt rollers 16 and 17. As shown in FIG. 1, among the belt rollers 16 and 17, the belt roller 16 located downstream in the conveying direction, that is, on the right side in the drawing, is driven to rotate clockwise in the drawing by a driving motor (not shown). A substantially rectangular parallelepiped platen 19 is disposed in a region surrounded by the conveyor belt 18 and supports the conveyor belt 18 from the inner peripheral surface side. Further, a pressing roller 15 is disposed immediately downstream of the paper feed tray 11 at a position facing the transport belt 18, and presses the paper fed from the paper feed tray 11 against the transport surface 18 a of the transport belt 18. ing.

  A paper discharge tray 13 is provided on the downstream side of the transport mechanism 12 along the transport direction. Further, a peeling member 13 a is provided between the transport belt 18 and the paper discharge tray 13. The peeling member 13 a peels the sheet held on the conveyance surface 18 a of the conveyance belt 18 from the conveyance surface 18 a and guides the sheet toward the paper discharge tray 13.

  As shown in FIGS. 1 and 2, the inkjet head 2 has an elongated rectangular parallelepiped shape that is long in one direction. Hereinafter, the longitudinal direction and the short direction of the inkjet head 2 in plan view are simply referred to as “longitudinal direction” and “short direction”. The printer 1 according to the present embodiment includes four inkjet heads 2 respectively corresponding to four color inks (magenta, yellow, cyan, and black). The four inkjet heads 2 are fixed to the frame-like frame 4 in a state where the inkjet heads 2 are arranged along the transport direction so that the short direction of each inkjet head 2 coincides with the transport direction. That is, the printer 1 is a line type printer.

  As shown in FIG. 1, the inkjet head 2 has a head body 3 at the lower end thereof. The lower surface of the head main body 3 is an ink discharge surface 2 a and faces the transport surface 18 a of the transport belt 18. As will be described in detail later, an ejection port formation region 3a in which a large number of ink ejection ports 8 are arranged is formed on the ink ejection surface 2a (see FIG. 6). When the paper transported by the transport belt 18 sequentially passes immediately below the four head bodies 3, ink droplets of each color are ejected from the ink ejection port 8 toward the upper surface of the paper, that is, the printing surface. Thus, a desired color image can be formed on the printing surface of the paper.

  As shown in FIG. 1, the printer 1 includes a control device 60 that controls the operation of the printer 1. The control device 60 is constituted by, for example, a general-purpose personal computer. Such a computer stores hardware such as a CPU, ROM, RAM, and hard disk, and various software such as a program for forming a test pattern to be described later is stored in the hard disk.

  Next, the head body 3 will be described with reference to FIGS. FIG. 3 is a plan view of the head body 3. FIG. 4 is an enlarged view of a region surrounded by a one-dot chain line in FIG. In FIG. 4, for convenience of explanation, what is to be drawn with a broken line below an actuator unit 21 to be described later (aperture 6, pressure chamber 7 and ink discharge port 8 to be described later) is drawn with a solid line. FIG. 5 is a partial cross-sectional view of the head body 3.

  As shown in FIG. 3, the head body 3 includes a flow path unit 20 having a rectangular shape in plan view and four trapezoidal actuator units 21 fixed on the upper surface of the flow path unit 20 in a staggered manner. More specifically, the four actuator units 21 are arranged such that the upper side (trapezoid upper bottom) and the lower side (trapezoid lower bottom) of the upper surface of the flow path unit 20 coincide with the longitudinal direction of the flow path unit 20, and Adjacent actuator units 21 are arranged such that the oblique sides are parallel to each other and the positions in the longitudinal direction are the same. The ink jet head 2 is formed by assembling a reservoir unit (not shown) for supplying ink and a driver IC (not shown) for generating a drive signal for driving the actuator unit 21 to the head body 3.

  As shown in FIG. 4, portions corresponding to the actuator units 21 on the lower surface of the flow path unit 20 are the above-described discharge port forming regions 3 a. That is, a large number of ink discharge ports 8 are formed in a matrix in a region facing the actuator unit 21. A large number of pressure chambers 7 communicating with the respective ink discharge ports 8 are formed on the upper surface of the flow path unit 20, and one actuator unit 21 is disposed so as to cover the large number of pressure chambers 7. Here, the actuator unit 21 includes a plurality of actuators corresponding to the pressure chambers 7 and has a function of selectively giving ejection energy to the ink in the pressure chambers 7.

  Further, as shown in FIG. 3, a total of ten ink supply ports 20 a are opened on the upper surface of the flow path unit 20 corresponding to the ink outflow flow paths (not shown) of the reservoir unit. As shown in FIG. 3, the flow path unit 20 has a manifold flow path 5 communicating with the ink supply port 20a, a sub-manifold flow path 5a branched from the manifold flow path 5 and extending in the longitudinal direction, and FIG. As shown, an individual ink channel 9 is formed from the sub-manifold channel 5a to the ink discharge port 8 through the aperture 6 and pressure chamber 7 functioning as a throttle. As a result, the ink from the reservoir unit is supplied to the manifold channel 5 via the ink supply port 20 a and further distributed to the pressure chambers 7. When the ejection energy is selectively applied to the pressure chamber 7 by the actuator unit 21, the pressure of the ink in the pressure chamber 7 rises, and ink is ejected from the ink ejection port 8 communicating with the pressure chamber 7. .

  Here, as shown in FIG. 4, the four sub-manifold channels 5 a extending in the longitudinal direction are formed at equal intervals in the lateral direction in the region facing the actuator unit 21. Further, a pressure chamber row is formed in the region facing the actuator unit 21 by the pressure chambers 7 arranged in the longitudinal direction at equal intervals. Two such pressure chamber rows are arranged in a region facing the four sub-manifold channels 5a, one on each of the two sides, that is, a total of sixteen. The ink discharge ports 8 communicating with the pressure chambers 7 are all formed in a region that does not face the sub-manifold channel 5a.

  As shown in FIG. 5, the flow path unit 20 has a cavity plate 22, a base plate 23, an aperture plate 24, a supply plate 25, manifold plates 26, 27, 28, a cover plate 29, and a nozzle plate 30 stacked from above. It has a laminated structure. That is, the lower surface of the nozzle plate 30 is an ink discharge surface 2a on which the discharge port formation region 3a is formed. Each plate 22-30 is comprised from metal plates, such as stainless steel, and as above-mentioned, the aperture 6 and the pressure chamber from the exit of the manifold channel 5, the sub manifold channel 5a, and the sub manifold channel 5a. 7 are stacked while being aligned with each other so that a large number of individual ink flow paths 9 extending to 7 and reaching the ink discharge port 8 are formed.

  Here, the arrangement of the ink discharge ports 8 will be described with reference to FIG. 6 which is a bottom view of the nozzle plate 30. As shown in FIG. 6, the nozzle plate 30 is formed with four ejection port formation regions 3a in which a large number of ink ejection ports 8 are arranged adjacent to each other in a matrix in two rows in a staggered manner along the longitudinal direction. ing. That is, two of the four discharge port forming regions 3a are arranged slightly shifted in the short direction one side (right side in FIG. 6) and the other two are slightly shifted in the short side direction other side (left side in FIG. 6). Has been. The inkjet head 2 is attached to the printer 1 with the nozzle plate 30 shown in FIG. 6 on the left side on the upstream side in the paper transport direction and on the right side on the downstream side.

  The discharge port formation region 3a is located in the region facing the actuator unit 21 as described above. That is, the discharge port forming region 3a has a trapezoidal shape that is substantially the same as the planar shape of the actuator unit 21, and is arranged so that the upper side and the lower side thereof are along the longitudinal direction. The hypotenuses of the adjacent discharge port forming regions 3a are parallel to each other and have the same position in the longitudinal direction.

  As shown in FIG. 7, which is an enlarged view of the region surrounded by the one-dot chain line in FIG. 6, the discharge port forming region 3 a extends in the longitudinal direction (left and right direction in the drawing) by a large number of ink discharge ports 8. A line is formed. Sixteen such rows are arranged in the short side direction (vertical direction in the drawing) in one discharge port formation region 3a, and are arranged in a region that does not face the sub-manifold channel 5a. In the following description, the 16 rows arranged in one discharge port formation region 3a are the first row, the second row,... It is called 16 lines.

  The ink discharge ports 8 in each row are arranged at equal intervals by a distance corresponding to 37.5 dpi in the longitudinal direction. Further, the number of ink discharge ports 8 included in each row is arranged so as to gradually decrease from the long side toward the short side corresponding to the trapezoidal shape of the discharge port forming region 3a.

  Here, a band-like region R1 that is a region that intersects two adjacent ink discharge ports 8 among a plurality of ink discharge ports 8 belonging to the second row and is sandwiched by two lines extending in the short direction. Think. In the belt-like region R1, in addition to the two ink discharge ports 8 belonging to the second row, there is one ink discharge port 8 belonging to 15 rows excluding the second row.

  FIG. 8 is an enlarged view showing the positional relationship of the 17 ink discharge ports 8 located in one strip region R1. In FIG. 8, the scales are different vertically and horizontally. As shown in FIG. 8, when these 17 ink ejection ports 8 are projected from a short direction perpendicular to the imaginary straight line extending in the longitudinal direction (left and right direction in FIG. 8), adjacent projection points are They are equally spaced at an interval corresponding to 600 dpi. Therefore, when the actuator unit 21 is appropriately driven while transporting the paper in the direction that coincides with the short direction, characters, figures, and the like can be drawn with a resolution of 600 dpi.

  In one ejection port formation region 3a, a large number of ink ejection ports 8 are periodically arranged in the width of the strip region R1. That is, as long as the rows to which the ink discharge ports 8 where the boundary of the strip-shaped region R1 intersects are the same, the arrangement of the ink discharge ports 8 in the inside is the same.

  The ink jet head 2 as described above is attached to the printer 1 such that its short direction (orthogonal direction orthogonal to the longitudinal direction) coincides with the sub-scanning direction which is the paper transport direction. However, when the inkjet head 2 is not attached at the correct position, or when the conveyance direction of the paper by the conveyance mechanism 12 is shifted, the short side direction of the inkjet head 2 and the sub-scanning direction do not match. At this time, a blank portion or the like is generated in the formed image and the image quality is lowered. Therefore, in the following, a method for inspecting the deviation between the short side direction and the sub-scanning direction of the inkjet head 2 attached to the printer 1 will be described.

  First, under the control of the control device 60, ink is ejected from the three ink ejection ports 8 corresponding to the first to third ejection ports, which will be described in detail later, toward the paper conveyed by the conveyance mechanism 12. A test pattern composed of three straight lines is formed. At this time, the control device 60 causes the length of the straight line drawn by the ink discharged from the second discharge port to be shorter than the length of the straight line drawn by the ink discharged from the first and third discharge ports. To control. More specifically, a program for forming a test pattern stored in the hard disk of the control device 60 is started as described above, and a predetermined actuator included in the actuator unit 21 is driven to form the test pattern. In the present embodiment, this program performs a process of ejecting ink from the three ink ejection ports 8 shown in black in FIG. 8 toward the sheet being conveyed. As a result, a test pattern composed of three straight lines is formed.

  As shown in FIG. 8, the three ink ejection ports 8 shown in black belong to the first row, the 16th row, and the ninth row, respectively, and the projection points on the virtual straight line are arranged in this order. The ink discharge ports 8 belonging to the first row, the 16th row, and the ninth row correspond to the first discharge port, the second discharge port, and the third discharge port, respectively. Here, the first row and the sixteenth row are two rows which are located on the outermost side among the 16 rows formed in one discharge port forming region 3a and are most separated in the short direction. ing. That is, the distance between the first and second discharge ports in the short direction is relatively large. Therefore, the distance between the two straight lines drawn by the ink ejected from the first and second ejection ports (hereinafter simply referred to as “distance L1”) depends on the deviation between the short side direction and the sub-scanning direction. , Change relatively large.

  Further, the third discharge port belongs to the ninth row located between the first row and the sixteenth row. In the present embodiment, with respect to the short direction, the third discharge port is located at a substantially central portion of the first discharge port and the second discharge port. That is, the distance between the first discharge port and the third discharge port in the short direction is shorter than the distance between the first discharge port and the second discharge port in the short direction. Therefore, the distance between the two straight lines drawn by the ink ejected from the first and third ejection ports (hereinafter simply referred to as “distance L2”) with respect to the deviation between the short direction and the sub-scanning direction. The change amount is smaller than the change amount of the distance L1. Further, on the virtual straight line, the projection point of the second discharge port is located between the projection points of the first and third discharge ports.

Here, when the short direction and the sub-scanning direction coincide with each other, the test pattern formed by ejecting ink from the three ink ejection ports 8 corresponding to the first to third ejection ports as described above. Is shown in FIG. The three straight lines shown in FIG. 9 respectively correspond to straight lines drawn by the ink ejected from the first ejection port, the second ejection port, and the third ejection port in order from the right. Of the three straight lines, the straight line located at the center, that is, the straight line drawn by the ink ejected from the second ejection port is shorter than the other two straight lines. As shown in FIG. 9, when the short side direction and the sub-scanning direction coincide with each other, the three straight lines are formed so as to be arranged at equal intervals. At this time, the distance L1 is L1 ₀ and the distance L2 is L2 ₀ .

  Further, as shown in FIG. 10A, a test in a case where the short side direction of the inkjet head 2 is shifted to the right on the downstream side in the transport direction in a plan view (when the inkjet head 2 rotates clockwise). The pattern is shown in FIG. Further, as shown in FIG. 10B, the test in the case where the short side direction of the inkjet head 2 is shifted to the left side on the downstream side in the transport direction in the plan view (when the inkjet head 2 rotates counterclockwise). The pattern is shown in FIG.

  As shown in FIG. 11, when the inkjet head 2 rotates clockwise, the distances L1 and L2 increase as compared to the case where the short side direction and the transport direction coincide with each other. Here, as described above, the change amount ΔL2 of the distance L2 with respect to the shift between the short side direction and the sub-scanning direction is smaller than the change amount ΔL1 of the distance L1.

  Accordingly, as shown in FIG. 11A, when the amount of deviation between the short direction and the transport direction is relatively small, a straight line drawn by the ink ejected from the second ejection port (the other two A straight line shorter than the straight line) is formed at a position closer to the left in the figure than the midpoint of the other two straight lines. As shown in FIG. 11B, when the amount of deviation between the short direction and the transport direction is relatively large, the straight line drawn by the ink ejected from the second ejection port is the leftmost in the figure. Formed.

  As shown in FIG. 12, when the inkjet head 2 rotates counterclockwise, the distances L1 and L2 decrease compared to the case where the short side direction and the transport direction coincide with each other. Here, as described above, the change amount ΔL2 of the distance L2 with respect to the shift between the short side direction and the sub-scanning direction is smaller than the change amount ΔL1 of the distance L1.

  Accordingly, as shown in FIG. 12A, when the amount of deviation between the short direction and the transport direction is relatively small, a straight line drawn by the ink discharged from the second discharge port (the other two lines). A straight line shorter than the straight line) is formed at a position closer to the right in the figure than the midpoint of the other two straight lines. As shown in FIG. 12B, when the amount of deviation between the short direction and the transport direction is relatively large, the straight line drawn by the ink ejected from the second ejection port is the rightmost side in the figure. Formed.

  Therefore, by observing the test pattern as described above, it is possible to know whether or not there is a deviation between the lateral direction and the sub-scanning direction, and if there is a deviation, the direction can be known. That is, when a test pattern as shown in FIGS. 11 and 12 is formed, the attachment position of the inkjet head 2 and the conveyance direction by the conveyance mechanism 12 are corrected so that the short side direction and the sub-scanning direction coincide with each other. To do.

  As described above, in the printer 1 of the present embodiment, the control device 60 draws the straight line drawn by the ink ejected from the second ejection port using the ink ejected from the first and third ejection ports. It is controlled so as to be different from the straight line mode. The first and second discharge ports belong to two non-adjacent rows, respectively. The third discharge port belongs to a row located between two non-adjacent rows to which the first and second discharge ports belong, and the projection point of the first discharge port with respect to the projection point of the second discharge port on the virtual straight line Projection points at symmetrical positions. Therefore, it is possible to easily identify the line drawn by the ink ejected from the second ejection port whose projection point is located at the center on the virtual straight line among the first to third ejection ports. Therefore, the visibility of the test pattern to be formed is improved.

  In the printer 1 of the present embodiment, the control device 60 determines that the length of the straight line drawn by the ink discharged from the second discharge port is the straight line drawn by the ink discharged from the first and third discharge ports. Control is made to be shorter than the length of. Accordingly, the control device 60 only controls the discharge time of the ink from the second discharge port to be shorter than the discharge time of the ink from the first and third discharge ports, and discharges from the second discharge port. The mode of the line drawn by the drawn ink and the mode of the line drawn by the ink ejected from the first and third ejection ports can be easily changed. Further, the amount of ink consumed for forming the test pattern can be reduced.

  Furthermore, in the printer 1 of the present embodiment, the control device 60 is for inspecting the deviation between the short side direction and the sub-scanning direction of the inkjet head 2 by discharging ink from the first to third discharge ports. A test pattern is formed. Here, the change amount of the distance L1 with respect to the shift between the short direction and the sub-scanning direction is larger than the change amount of the distance L2. Therefore, by observing the positional relationship between the three straight lines drawn by the ink ejected from the first to third ejection ports, it is possible to easily inspect the deviation between the short-side direction and the sub-scanning direction.

  In addition, in the printer 1 of the present embodiment, the first and second ejection ports are the two outermost rows among the 16 rows formed in one ejection port formation region 3a, that is, the short ones. They belong to the first row and the 16th row, which are the two rows that are most separated in the hand direction. Therefore, the amount of change in the distance L1 is the largest with respect to the deviation between the short direction and the sub-scanning direction. Therefore, it is possible to inspect the deviation between the short direction and the sub-scanning direction with high accuracy.

  In the printer 1 of the present embodiment, the projection points of the first to third ejection ports are adjacent to each other on a virtual straight line. Therefore, since three lines drawn by the ink ejected from the first to third ejection ports are formed close to each other, it is easy to observe the positional relationship between the three straight lines.

  The preferred embodiment of the present invention has been described above. However, the present invention is not limited to the above-described embodiment, and various design changes can be made as long as they are described in the claims. Is something. For example, in the above-described embodiment, the control device 60 determines that the length of the straight line drawn by the ink ejected from the second ejection port is the length of the straight line drawn by the ink ejected from the first and third ejection ports. The case where the control is performed to be shorter than the above has been described, but conversely, the length of the straight line drawn by the ink discharged from the second discharge port is drawn by the ink discharged from the first and third discharge ports. You may control so that it may become longer than the length of a straight line. Further, as shown in FIG. 13A, the control device 60 draws the thickness of the straight line drawn by the ink ejected from the second ejection port by the ink ejected from the first and third ejection ports. It may be controlled to be thinner than the thickness of the straight line (first modified example), and as shown in FIG. 13B, a straight line drawn by the ink ejected from the second ejection port The seed may be controlled to be different from the straight line type drawn by the ink ejected from the first and third ejection ports (second modified example).

  Furthermore, in the above-described embodiment, a case has been described in which the control device 60 performs control so that ink is ejected from the three ink ejection ports 8 corresponding to the first to third ejection ports and three straight lines are drawn. However, it is not limited to this.

  For example, since the large number of ink discharge ports 8 are periodically arranged in the width of the strip-shaped region R1, the control device 60 has three ink discharge ports corresponding to the first to third discharge ports in the plurality of strip-shaped regions R1. Control may be performed so that ink is ejected from each of the ink ejection ports 8 (third modification). Thereby, as shown in FIG. 14, a plurality of three straight lines drawn by the first to third ejection ports are formed in the main scanning direction that coincides with the longitudinal direction of the inkjet head 2. That is, a plurality of three straight lines are drawn by different ink discharge ports 8. When such a test pattern is formed, the positional relationship between the three straight lines is caused by a defect of the ink ejection port 8 that ejects ink, or the lateral direction and the sub-scanning direction are shifted. It is possible to determine whether it is caused by.

  Further, for example, as shown in FIG. 15, the control device 60 may control so that a plurality of three lines drawn by the ink ejected from the first to third ejection ports are formed in the sub-scanning direction. Good (fourth modification). In the case where such a test pattern is formed, even if the conveyance of the paper is temporarily disturbed due to a malfunction of the conveyance mechanism 12 or the positional relationship between the three straight lines is disturbed, the short direction is highly reliable. Deviation from the sub-scanning direction can be detected.

  Furthermore, in the above-described embodiment, the case where the first and second discharge ports belong to the two rows that are the most separated in the lateral direction has been described. However, the present invention is not limited to this, and the first and second discharge ports It is sufficient that the row to which two belong are two rows that are not adjacent to each other.

  In addition, in the above-described embodiment, the case where the projection points of the first to third ejection ports are adjacent to each other on the virtual straight line has been described, but these projection points may not be adjacent to each other.

1 is a schematic side view showing an overall configuration of a printer according to an embodiment of the present invention. It is a schematic plan view of the principal part of the printer shown in FIG. It is a top view of the head main body shown in FIG. FIG. 4 is an enlarged view of a region surrounded by an alternate long and short dash line in FIG. 3. FIG. 4 is a partial cross-sectional view of the head body shown in FIG. 3. It is a bottom view of the nozzle plate shown in FIG. It is an enlarged view of the area | region enclosed with the dashed-dotted line shown in FIG. It is the figure which expanded and showed the positional relationship of the ink discharge port located in strip | belt-shaped area | region R1 shown in FIG. It is a test pattern drawn by an embodiment of the invention, and is a figure showing a test pattern in the case where a transversal direction and a sub scanning direction are in agreement. It is a figure which shows the shift | offset | difference degree of the transversal direction and subscanning direction of the inkjet head shown in FIG. It is a figure which shows the test pattern formed when a transversal direction and a subscanning direction have shifted | deviated as shown to Fig.10 (a). It is a figure which shows the test pattern formed when a transversal direction and a subscanning direction have shifted | deviated as shown in FIG.10 (b). (A) is a figure which shows the test pattern drawn by the 1st modification of this invention, (b) is a figure which shows the test pattern drawn by the 2nd modification of this invention. It is a figure which shows the test pattern drawn by the 3rd modification of this invention. It is a figure which shows the test pattern drawn by the 4th modification of this invention.

Explanation of symbols

1 Printer 2 Inkjet head (liquid ejection head)
2a Ink ejection surface (ejection surface)
3a Discharge port forming area 8 Ink discharge port (discharge port)
60 Control device (discharge control means)

Claims (9)

In the discharge surface on which the discharge ports for discharging the liquid are formed, a plurality of parallel rows in which the discharge ports are arranged along one direction are formed, and all the discharge ports constituting the plurality of rows are Plural so that the projection points of the discharge ports are arranged at equal intervals on the virtual straight line when projected from an orthogonal direction orthogonal to the one direction within a plane including the discharge surface on a virtual straight line along one direction A liquid discharge head in which the discharge ports are arranged;
The first discharge port and the second discharge port, which are the discharge ports belonging to the two non-adjacent rows, belong to the row located between the two non-adjacent rows, and the virtual straight line With respect to the projection point of the second discharge port, using the three types of discharge ports, the third discharge port, which is the discharge port having the projection point at a position symmetrical to the projection point of the first discharge port, the second discharge port is used. A discharge control means for controlling the liquid to be discharged such that a line drawn by the liquid discharged from the outlet is different from a line drawn by the liquid discharged from the first and third discharge ports; A printer characterized by comprising:   The discharge control means is configured such that at least one of the length, thickness, and line type of a line drawn by the liquid discharged from the second discharge port is discharged from the first and third discharge ports. The printer according to claim 1, wherein the printer is controlled so as to be different from a line drawn by.   The discharge control unit discharges liquid from the first to third discharge ports, thereby inspecting a deviation between the sub-scanning direction, which is the direction of relative movement of the liquid discharge head and the recording medium, and the orthogonal direction. The printer according to claim 1, wherein a test pattern is formed.   The printer according to claim 3, wherein the two rows to which the first and second discharge ports belong are the farthest in the orthogonal direction.   5. The printer according to claim 3, wherein projection points of the first to third ejection ports are adjacent to each other on a virtual straight line.   The ejection control means is configured so that three lines drawn by the liquid ejected from the first to third ejection ports are orthogonal to a sub operation direction that is a relative movement direction of the liquid ejection head and the recording medium. 6. The printer according to claim 3, wherein a plurality of printers are controlled.   In the ejection control means, a plurality of three lines drawn by the liquid ejected from the first to third ejection ports are formed in the sub-scanning direction, which is the direction of relative movement of the liquid ejection head and the recording medium. The printer according to claim 3, wherein the printer is controlled as follows. In the discharge surface on which the discharge ports for discharging the liquid are formed, a plurality of parallel rows in which the discharge ports are arranged along one direction are formed, and all the discharge ports constituting the plurality of rows are Plural so that the projection points of the discharge ports are arranged at equal intervals on the virtual straight line when projected from an orthogonal direction orthogonal to the one direction within a plane including the discharge surface on a virtual straight line along one direction A test pattern forming method for forming a test pattern in a printer having a liquid discharge head in which the discharge ports are arranged,
The first discharge port and the second discharge port, which are the discharge ports belonging to the two non-adjacent rows, belong to the row located between the two non-adjacent rows, and the virtual straight line With respect to the projection point of the second discharge port, using the three types of discharge ports, the third discharge port, which is the discharge port having the projection point at a position symmetrical to the projection point of the first discharge port, the second discharge port is used. A test pattern is formed by discharging a liquid such that a line drawn by the liquid discharged from the outlet is different from a line drawn by the liquid discharged from the first and third discharge ports. A test pattern forming method. In the discharge surface on which the discharge ports for discharging the liquid are formed, a plurality of parallel rows in which the discharge ports are arranged along one direction are formed, and all the discharge ports constituting the plurality of rows are The projection points of the discharge ports are arranged at equal intervals on the virtual straight line when projected from an orthogonal direction orthogonal to the one direction in a plane including the discharge surface on a virtual straight line along one direction. In a printer having a liquid discharge head in which a plurality of discharge ports are arranged, a test pattern forming program for causing a computer to execute test pattern formation,
The first discharge port and the second discharge port, which are the discharge ports belonging to the two non-adjacent rows, belong to the row located between the two non-adjacent rows, and the virtual straight line With respect to the projection point of the second discharge port, using the three types of discharge ports, the third discharge port, which is the discharge port having the projection point at a position symmetrical to the projection point of the first discharge port, the second discharge port is used. Causing the computer to execute a process of discharging the liquid so that a line drawn by the liquid discharged from the outlet is different from a line drawn by the liquid discharged from the first and third discharge ports. A test pattern formation program.

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