JP2010179583A - Head unit position adjusting method and recording device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem that test patterns are not printed on a proper position on sheets and highly accurate alignment adjustment cannot be carried out when positional displacement or skew travel is generated in the sheets when printing the test patterns. <P>SOLUTION: A conveying information calculating section 92 calculates out the conveying information 98j of the sheet P when printing the test pattern and storing the same in the recording section 98. Further, a reception section 97 accepts measuring position information 97j of the test pattern and a head position adjusting section 94 adjust the head units 10, 20 to the positions where the head units 10, 20 should be positioned based on the accepted measuring position information 97j of the test pattern and the recorded conveying information 98j of the sheet P. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a head unit position adjusting method and a recording apparatus.

  2. Description of the Related Art Conventionally, various techniques have been proposed for recording at an accurate position on a recording medium in a recording apparatus such as an ink jet printer or a laser beam printer. For example, in the misalignment correction apparatus for an ink jet printer described in Patent Document 1 below, an alignment adjustment mechanism that enables the line head to rotate is provided, and a test pattern is printed on the paper from the line head to test on the paper. The line head alignment is adjusted based on the pattern position.

JP 2008-12712 A

  However, in the misalignment correction apparatus as described in Patent Document 1 described above, when the test pattern is printed on the sheet from the line head, misalignment or skew occurs on the sheet on the conveyance surface. As a result, the printed test pattern is misaligned or tilted. As a result, the alignment adjustment of the line head is performed based on the test pattern in which the positional deviation, the inclination, etc. occur, and there is a problem that the alignment adjustment with high accuracy cannot be performed.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following forms or application examples.

[Application Example 1]
The head unit position adjustment method according to this application example includes a test pattern recording step of recording a test pattern on the recording medium from a head unit that records the liquid by ejecting liquid onto the recording medium conveyed on the conveyance surface, and the test When recording the test pattern on the recording medium in the pattern recording step, the recording step is performed based on the detection step for detecting the position of the transported recording medium and the position of the recording medium detected in the detection step. A conveyance information calculation step for calculating conveyance information indicating a conveyance state of the medium, a storage step for storing the conveyance information calculated in the conveyance information calculation step, the conveyance information stored in the storage step, and the recording Based on the measurement position information indicating the measurement result of the test pattern position recorded on the medium, the head unit is Serial moved in the conveying direction parallel to the surface and having a head position adjustment step of correcting the positional deviation of the head unit.

According to this head unit position adjustment method, the conveyance information of the recording medium when the test pattern is recorded in the test pattern recording process is calculated in the conveyance information calculation process and stored in the storage process. Then, in the head position adjustment step, the positional deviation of the head unit is corrected based on the stored conveyance information and the measurement position information indicating the measurement result of the test pattern position.
Since the position of the head unit is adjusted based on the conveyance information of the recording medium and the measurement position information of the test pattern, if there is a positional deviation or the like in the recording medium when recording the test pattern, the positional deviation or the like The head unit position can be corrected by subtracting the influence. Thereby, highly accurate alignment adjustment can be performed with respect to the head unit.

[Application Example 2]
In the head unit position adjustment method according to the application example, the conveyance information includes a displacement amount of the recording medium from a predetermined reference position in the width direction of the recording medium on the conveyance surface, and the measurement position information is The recording medium preferably includes a displacement amount of the test pattern from a predetermined reference position in the width direction of the recording medium.

  According to this head unit position adjustment method, the conveyance information includes the positional deviation amount in the width direction of the recording medium, and the measurement position information includes the positional deviation amount of the test pattern in the width direction of the recording medium. Thereby, in the width direction of the recording medium, it is possible to cancel the influence of the positional deviation amount of the recording medium from the positional deviation amount of the test pattern.

[Application Example 3]
In the head unit position adjustment method according to the application example, in the head position adjustment step, the movement amount in the width direction of the head unit is calculated based on the positional deviation amount of the recording medium and the positional deviation amount of the test pattern. It is preferable that the head unit is moved in a direction crossing the transport direction of the recording medium in accordance with the calculated movement amount in the width direction.

  According to this head unit position adjustment method, in the width direction of the recording medium, it is possible to calculate the movement amount in the width direction that offsets the influence of the position deviation amount of the recording medium from the position deviation amount of the test pattern. Then, the positional deviation of the head unit can be corrected by moving the head unit in accordance with the movement amount in the width direction.

[Application Example 4]
In the head unit position adjustment method according to the application example, the conveyance information includes a skew amount of the recording medium on the conveyance surface, and the measurement position information includes an inclination amount of the test pattern on the recording medium. Is desirable.

  According to this head unit position adjustment method, the conveyance information includes the skew amount of the recording medium, and the measurement position information includes the inclination amount of the test pattern on the recording medium. Thereby, the influence of the skew amount of the recording medium can be offset from the inclination amount of the test pattern.

[Application Example 5]
In the head unit position adjustment method according to the application example, in the head position adjustment step, the rotation amount of the head unit is calculated based on the skew amount of the recording medium and the inclination amount of the test pattern, and the calculation is performed. It is desirable to rotate the head unit about an axis in a direction perpendicular to the transport surface in accordance with the amount of rotation.

According to this head unit position adjustment method, it is possible to calculate the rotation amount of the head unit that offsets the influence of the skew amount of the recording medium from the inclination amount of the test pattern. Then, the tilt of the head unit can be corrected by rotating the head unit in accordance with the rotation amount.
[Application Example 6]
The recording apparatus according to this application example is characterized in that the position of the head unit is adjusted by the above-described head unit position adjustment method.

  According to this recording apparatus, it is possible to provide a head unit that has been subjected to highly accurate alignment adjustment, and it is possible to perform recording from the head unit to an accurate position of the recording medium.

1 is a side sectional view schematically showing an outline of an ink jet printer according to a first embodiment. FIG. 2 is a plan view schematically showing an outline of an ink jet printer. Explanatory drawing of the arrangement | sequence of each discharge head. Explanatory drawing of the mechanism and operation | movement which concern on reciprocation and rotation of a head unit. FIG. 3 is a plan view of an ink jet printer showing an example in which a test pattern is displaced. The top view of the inkjet printer which shows the example in which the test pattern inclines. FIG. 6 is an explanatory diagram for calculating the amount of movement in the width direction of the head unit from the amount of positional deviation of the test pattern and the amount of positional deviation of the paper. Explanatory drawing which shows the example of the test pattern of position shift. FIG. 5 is an explanatory diagram for calculating the rotation amount of the head unit from the inclination amount of the test pattern and the skew amount of the paper. Explanatory drawing which shows the example of the inclined test pattern. The flowchart which shows the operation | movement which prints a test pattern. The flowchart which shows the operation | movement which correct | amends a head unit. The figure which shows the test pattern for position shift correction in 2nd Embodiment. The figure which shows the test pattern for inclination correction | amendment in 2nd Embodiment. 6 is a flowchart showing an operation for printing a test pattern for correcting misalignment. 9 is a flowchart showing an operation for correcting movement of the head unit in the width direction according to the second embodiment. 6 is a flowchart illustrating an operation for printing a test pattern for tilt correction. 10 is a flowchart showing an operation of correcting the rotation of the head unit in the second embodiment. FIG. 6 is a side sectional view schematically showing an outline of an ink jet printer according to a modification.

(First embodiment)
Hereinafter, as an example of a recording apparatus that includes a recording position correction device that adjusts the position of a head unit by a head unit position adjustment method and that records on a recording medium, a recording medium such as paper by ejecting (discharging) a liquid such as ink The inkjet printer according to the first embodiment for printing an image or the like will be described. The ink jet printer here includes two head units in which a plurality of ink jet heads (ejection heads) are arranged in a direction intersecting the paper transport direction, and is a line head type ink jet printer capable of printing in a so-called one pass. It is.

  FIG. 1 is a side sectional view schematically showing an outline of the ink jet printer 100 according to the first embodiment. FIG. 2 is a plan view schematically showing the outline of the inkjet printer 100. Inside the inkjet printer 100 shown in FIG. 1 and FIG. 2, a transport unit 1 that holds and transports the paper P to be printed, and printing that performs printing on the paper P held and transported by the transport unit 1. Part 2 is provided. The operations of the transport unit 1 and the printing unit 2 are controlled by a control unit 90 shown in FIG. In the following description, the normal transport direction of the paper P in the ink jet printer 100 is referred to as a transport direction X, and the direction orthogonal to the transport direction X is referred to as a transport width direction Y.

  The conveyance unit 1 includes a gate roller 31 constituted by a pair of upper and lower nip rollers shown in FIG. 1, a driven roller 32 disposed on the upstream side in the conveyance direction X, and a drive roller disposed on the downstream side in the conveyance direction X. 34, a tension roller 33 disposed below the driven roller 32 and the drive roller 34, an endless belt 35 that winds between the three rollers 32, 33, and 34 in a loop.

  The drive roller 34 is a roller for applying a transport force in the transport direction X to the endless belt 35. As shown in FIG. 2, a conveyance drive motor 36 for transmitting power to the drive roller 34 is directly connected to one end in the conveyance width direction Y. On the other hand, the driven roller 32 is a roller having the same height as that of the driving roller 34 and facing and arranged in parallel with a certain distance.

  The endless belt 35 is an endless belt-shaped member formed of a material having elasticity such as a synthetic rubber or a resin film. As shown in FIG. 2, the endless belt 35 has a large number of air holes 37 formed therein. The suction and holding action of the paper P by a suction device (not shown) is executed through the vent hole 37 so that the paper P is sucked and held on the transport surface 50 of the endless belt 35 that transports the paper P. Here, as a suction method of the suction device, for example, suction by negative pressure or electrostatic suction can be employed.

  On the other hand, the printing unit 2 includes a head unit 10 disposed on the upstream side in the transport direction X, a head unit 20 disposed on the downstream side, and the like. As shown in FIG. 2, each head unit 10, 20 includes a plurality of ejection heads 11 that eject ink droplets in each head panel 12. These ejection heads 11 are divided (separated) in the transport direction X by each of the head units 10 and 20, and four are arranged in the head unit 10 row and three in the head unit 20 row. The ejection heads 11 in each row are also divided (separated) in the transport width direction Y so that the entire ejection heads 11 are staggered in plan view, that is, transported along the transport width direction Y. They are alternately arranged upstream and downstream in the direction X.

The head units 10 and 20 can be reciprocated in the transport width direction Y that is parallel to the transport surface 50. Further, each of the head units 10 and 20 can be rotated clockwise and counterclockwise around an axis in a direction perpendicular to the conveyance surface 50 around the θ rotation shaft 13. That is, each head unit 10, 20 can be rotated in a direction parallel to the transport surface 50.
Details of the reciprocation and rotation of the head units 10 and 20 will be described later.

FIG. 3 is an explanatory diagram of the arrangement of the ejection heads 11 and is a view of the head units 10 and 20 as viewed from below. As shown in the figure, on the surface (nozzle surface) of each ejection head 11 facing the transport surface 50, a number of nozzles that eject ink droplets are formed.
Specifically, on each nozzle surface, four rows of nozzle rows composed of a plurality of nozzles arranged along the transport width direction Y are formed apart from each other in the transport direction X. These four nozzle arrays can eject inks of different colors. In this embodiment, black (K), cyan (C), magenta (M), yellow are sequentially arranged from the upstream side in the transport direction X. (Y) ink is ejected.

  In addition, each discharge head 11 is superposed in the transport direction X with the nozzle at the transport width direction Y end of the adjacent discharge head 11 that is spaced apart in the transport direction X or the opposite direction. It is arranged. Then, for each color, that is, for each nozzle row, a necessary amount of ink droplets are simultaneously ejected from the nozzles at the necessary locations, thereby forming minute ink dots on the paper P. The ink jet printer 100 repeats this operation while transporting the paper P in the transport direction X. Then, only by feeding the paper P in the transport direction X in one pass, an image having a width corresponding to the distance between the nozzles at both ends of the head units 10 and 20 in the transport width direction Y can be printed.

The method for ejecting ink from the nozzles is not limited to a specific method, and various methods such as an electrostatic method, a piezo method, and a film boiling ink jet method can be employed.
The electrostatic method is a method in which a drive pulse is applied to the electrostatic gap to displace the diaphragm in the cavity, and ink droplets are ejected by a pressure change in the cavity caused by the displacement. The piezo method is a method in which a drive pulse is applied to a piezo element to displace a diaphragm in a cavity, and ink droplets are ejected by a pressure change in the cavity caused by the displacement. The film boiling ink jet method is a method in which ink is heated by a micro heater provided in a cavity, and ink droplets are ejected by a pressure change accompanying generation of bubbles.

FIG. 4 is an explanatory diagram of the mechanism and operation related to the reciprocating movement and rotation of the head unit 10. The head unit 10 shown in the figure includes a Y-axis motor 14 for transmitting power for reciprocating the head panel 12 in the transport width direction Y, a slide rail (not shown) extending along the transport width direction Y, and a head. A θ-axis motor 15 that transmits power for rotating the panel 12 around the θ-rotating shaft 13 is attached. As with the head unit 10, the head unit 20 is also provided with a Y-axis motor 14, a slide rail, and a θ-axis motor 15. The head unit 20 can be reciprocated in the transport width direction Y and rotated about the θ rotation shaft 13.
In this embodiment, as the Y-axis motor 14 and the θ-axis motor 15 attached to the head units 10 and 20, for example, a linear ultrasonic motor capable of controlling a minute displacement is used.

  4A shows an example in which the head unit 10 is moved by Ya in the transport width direction Y from the reference position in the transport width direction Y. FIG. Here, based on the control of the control unit 90, the Y-axis motor 14 is driven, and the head unit 10 can be moved by Ya in the transport width direction Y according to the slide rail so as to be in the position of the broken line portion.

  FIG. 4B shows an example in which the head unit 10 is rotated clockwise from the reference position by the angle θa about the θ rotation shaft 13. Here, based on the control of the control unit 90, the θ-axis motor 15 is driven, and the head unit 10 is rotated clockwise about the θ rotation shaft 13 by an angle θa to the position of the broken line portion. be able to.

Here, as a combination of FIGS. 4A and 4B, the Y-axis motor 14 is driven to move the head panel 12 in the transport width direction Y, and then the θ-axis motor 15 is driven to The panel 12 can be rotated about the θ rotation axis 13. Conversely, the θ-axis motor 15 is driven to rotate the head panel 12 around the θ-rotation shaft 13, and then the Y-axis motor 14 is driven to move the head panel 12 in the transport width direction Y. You may make it let it. Alternatively, the head panel 12 may be moved and rotated in the transport width direction Y at the same time.
Note that the positions of the θ rotation shaft 13, the Y axis motor 14, and the θ axis motor 15 are not limited to the positions shown in FIG.

Referring back to FIGS. 1 and 2, two edge sensors S1 and S2 are disposed on the upstream side in the transport direction X across the head unit 10, and two edge sensors S3 and S4 are disposed on the downstream side. Two edge sensors S5 and S6 are arranged on the upstream side in the transport direction X across the head unit 20, and two edge sensors S7 and S8 are arranged on the downstream side.
Here, the edge sensors S1 to S8 are sensors as detection units that detect the position of the end in the width direction of the paper P. For example, the light emitting elements and the light receiving elements of the edge sensors S1 to S8 are transport surfaces 50. This is a reflection-type image sensor with a structure that faces the direction.

The edge sensors S1 to S8 detect the position of the edge in the width direction of the paper P on the conveyance surface 50 by irradiating light from the light emitting elements in the direction of the conveyance surface 50 and receiving reflected light by a plurality of light receiving elements. be able to. In the present embodiment, for example, a CCD image sensor or a CMOS image sensor is used as the edge sensors S1 to S8.
Further, these edge sensors S1 to S8 may be automatically moved to a position where the position of the end portion in the width direction of the paper P can be detected according to the size in the width direction of the paper P.

  Note that the number and arrangement positions of the edge sensors to be arranged are not limited to the above. For example, the position of the paper P is detected by arranging only one edge sensor or three or more edge sensors on the upstream and downstream sides of each head unit 10 and 20. You may make it do. Alternatively, the edge sensor may be disposed only on either the upstream side or the downstream side of the head units 10 and 20.

  A control unit 90 shown in FIG. 2 includes a CPU, a ROM, a RAM, and the like (not shown), and controls the respective units such as the receiving unit 97 and the storage unit 98 in the inkjet printer 100 and the entire mechanisms. The control unit 90 includes a test pattern recording unit 91, a conveyance information calculation unit 92, a head movement amount calculation unit 93, a head position adjustment unit 94, and the like.

  The test pattern recording unit 91 prints each test pattern on the paper P from each of the head units 10 and 20. This test pattern is used to adjust the position of each head unit 10, 20 on the transport surface 50.

Next, the conveyance information calculation unit 92 calculates conveyance information indicating the conveyance state of the paper P on the conveyance surface 50. This conveyance information includes the positional deviation amount and skew amount of the paper P. The positional deviation amount and the skew amount are calculated based on the position of the edge in the width direction of the paper P detected by the edge sensors S1 to S8 when the paper P is transported on the transport surface 50. The calculated conveyance information is stored as conveyance information 98j in the storage unit 98 described later.
The misregistration amount here is the misregistration amount of the paper P from the predetermined reference position in the conveyance width direction Y, that is, the misregistration amount of the paper P on the conveyance surface 50, and the misalignment amount of the paper P Represents the distance to the end in the width direction. Further, the skew amount represents the amount of inclination of the end portion in the width direction of the paper P with respect to the transport direction X, that is, the skew amount of the paper P on the transport surface 50.

  Next, the head movement amount calculation unit 93 includes the positional deviation amount and skew of the paper P included in the measurement position information 97j input by the user from the receiving unit 97 described later and the conveyance information 98j stored in the storage unit 98. Based on the amount, a head movement amount for moving and adjusting the position of each head unit 10, 20 on the conveyance surface 50 to an appropriate position where the head unit 10, 20 should be positioned is calculated. This head movement amount includes a width direction movement amount for moving each head unit 10, 20 in the conveyance width direction Y and a rotation amount for rotating each head unit 10, 20 about the θ rotation axis 13. .

  Here, the measurement position information 97j input by the user is a measurement value obtained by measuring the position of the test pattern printed on the paper P by the test pattern recording unit 91 using an optical device such as a microscope. FIG. 5 is a plan view of the inkjet printer 100 showing an example in which the printed test pattern is displaced. FIG. 6 is a plan view of the inkjet printer 100 showing an example in which the printed test pattern is inclined.

In FIG. 5, a straight line L11 that is a test pattern from the head unit 10 is printed on the paper P, and a straight line L21 that is a test pattern from the head unit 20 is printed on the paper P. Here, the lines L11 and L21 on the paper P are parallel to each other, but are printed with their positions shifted in the transport width direction Y. This is due to the positional deviation of the head units 10 and 20 in the conveyance width direction Y and the positional deviation of the paper P in the conveyance width direction Y during the printing of the lines L11 and L21.
In FIG. 6, the line L11 is printed on the paper P from the head unit 10 and the line L21 is printed on the paper P from the head unit 20 as in FIG. Here, the lines L11 and L21 on the paper P are printed with an inclination with respect to the transport width direction Y. This is due to the inclination of the head units 10 and 20 and the skew of the paper P during the printing of the lines L11 and L21.
Note that the test print printed on the paper P is not limited to a straight line, and may be, for example, a curve or a pattern.

An example of calculating the amount of movement in the width direction for moving and adjusting the head units 10 and 20 in the conveyance width direction Y will be described.
FIG. 7 is an explanatory diagram for calculating the amount of movement in the width direction of the head units 10 and 20 from the amount of positional deviation of the test pattern and the amount of positional deviation of the paper P. As described above, the test pattern position deviation amount is input by the user as the measurement position information 97j. Further, the positional deviation amount of the paper P is calculated by the conveyance information calculation unit 92 and stored in the storage unit 98 as conveyance information 98j.
In the example of FIG. 7, lines L11 and L21 that are displaced from each other are printed as test patterns, and the user can determine the interval a1 from the width direction end of the paper P to the end T11 of the line L11 and the width of the paper P. The distance a2 from the direction end to the end T21 of the line L21 is measured. And a user inputs the value of measured space | interval a1 and a2 from the receiving part 97 as the measurement position information 97j of each line L11, L21.
On the other hand, in the example of FIG. 7, the positional deviation amount of the paper P is an interval from the reference line L01 indicating the predetermined reference position on the transport surface 50 to the end in the width direction of the paper P, and when the line L11 is printed. The conveyance information calculation unit 92 calculates an interval b1 from the reference line L01 to the end of the paper P and an interval b2 from the reference line L01 to the end of the paper P when the line L21 is printed.

The amount of movement in the width direction of the head unit 10 is calculated based on the interval a1 to the end T11 of the line L11, the interval b1 to the end of the paper P, and the margin setting value in the width direction of the paper P. The amount of movement in the width direction of the head unit 20 is calculated based on the distance a2 to the end T21 of the line L21, the distance b2 to the end of the paper P, and the margin setting value in the width direction of the paper P. The
Specifically, when the margin setting value of the paper P is m, it is calculated by the following equation.
(Amount of movement in the width direction of the head unit 10) = − (interval a1 + interval b1−margin setting value m)
(Amount of movement in the width direction of the head unit 20) = − (interval a2 + interval b2−margin setting value m)
Here, when the movement amount in the width direction is negative, it is a movement amount that moves the head unit in the direction opposite to the conveyance width direction Y, and when it is positive, it is the movement amount that moves the head unit in the conveyance width direction Y. .

FIG. 8 is an explanatory diagram showing an example of a test pattern for positional deviation. In the figure, an example of the line L11 printed from the head unit 10 is shown, but the same applies to the line L21 printed from the head unit 20. In FIG. 8A, the interval a1 to the end T11 of the line L11 is 30 mm, and the interval b1 to the end of the paper P is 10 mm. In this case, if the margin setting value m is 20 mm, the movement amount in the width direction of the head unit 10 is calculated as −20 by calculating − (30 + 10−20). That is, the head unit 10 is moved by 20 mm in the direction opposite to the conveyance width direction Y.
On the other hand, in FIG. 8B, the interval a1 to the end T11 of the line L11 is 10 mm, the interval b1 to the end of the paper P is 0 mm, that is, the paper P is not misaligned. ing. In this case, if the margin setting value m is 20 mm, the amount of movement in the width direction of the head unit 10 is calculated as +10 by calculating − (10 + 0−20). That is, the head unit 10 is moved by 10 mm in the transport width direction Y.

An example in which the amount of rotation for adjusting the inclination of each head unit 10, 20 is calculated will be described.
FIG. 9 is an explanatory diagram for calculating the rotation amounts of the head units 10 and 20 from the inclination amount of the test pattern and the skew amount of the paper P. As described above, the inclination amount of the test pattern is input as measurement position information 97j by the user. The skew amount of the paper P is calculated by the conveyance information calculation unit 92 and stored in the storage unit 98 as conveyance information 98j.
In the example of FIG. 9, inclined lines L11 and L21 are printed as test patterns, and the user measures a distance c11 from the leading end of the paper P to the end T11 of the line L11 and a distance c12 to the end T12. Then, the angle θ1 formed by the difference between the interval c11 and the interval c12 is calculated. Further, the user measures the distance c21 from the leading end of the paper P to the end T21 of the line L21 and the distance c22 from the end T22, and determines the angle θ2 formed by the difference between the distance c21 and the distance c22. calculate. Then, the user inputs the calculated values of the angles θ1 and θ2 as the measurement position information 97j of the lines L11 and L21 from the reception unit 97. These angles θ1 and θ2 are the amounts of inclination of the lines L11 and L21 with respect to the width direction of the paper P.
Here, the user may input the values of the measured intervals c11, c12, c21, and c22 as the measurement position information 97j instead of inputting the values of the angles θ1 and θ2. In this case, the values of the angles θ1 and θ2 are calculated, for example, by the head movement amount calculation unit 93 based on the input values of the intervals c11, c12, c21, and c22.

  On the other hand, the skew amount of the paper P is the angle of inclination of the end portion in the width direction of the paper P with respect to the reference line L01 parallel to the transport direction X in the example of FIG. The angle θp1 of the edge of the paper P with respect to the reference line L01 when printing the line L11 and the angle θp2 of the edge of the paper P with respect to the reference line L01 when printing the line L21 are the paper The conveyance information calculation unit 92 calculates the skew amount of P.

The rotation amount of the head unit 10 is calculated based on the angle θ1 indicating the inclination amount of the line L11 and the angle θp1 indicating the skew amount of the paper P. Further, the rotation amount of the head unit 20 is calculated based on an angle θ2 indicating the amount of inclination of the line L21 and an angle θp2 indicating the skew amount of the paper P. Here, the angles θ1 and θ2 of inclination when the end portions T11 and T21 of the lines L11 and L21 are located downstream of the end portions T12 and T22 are positive. Further, each angle θp1 and θp2 indicating the amount of inclination when the leading edge of the paper P is positioned in the transport width direction Y relative to the trailing edge is defined as positive. In the example of FIG. 9, the angle θ1 is positive, the angle θ2 is negative, and the angles θp1 and θp2 are both positive. In this case, specifically, it is calculated by the following equation.
(Rotation amount of the head unit 10) = − (angle θ1 + angle θp1)
(Rotation amount of the head unit 20) = − (angle θ2 + angle θp2)
Here, when the rotation amount is negative, it is a rotation amount that rotates the head unit counterclockwise, and when it is positive, it is the rotation amount that rotates the head unit clockwise.

FIG. 10 is an explanatory diagram showing an example of a tilted test pattern. In the figure, an example of the line L11 printed from the head unit 10 is shown, but the same applies to the line L21 printed from the head unit 20. In FIG. 10A, the angle θ1 indicating the inclination of the line L11 is + 30 °, and the angle θp1 indicating the skew of the paper P is + 10 °. In this case, the rotation amount of the head unit 10 is calculated as −40 by calculating − (30 + 10). That is, the head unit 10 is rotated by 40 ° counterclockwise about the θ rotation shaft 13.
On the other hand, in FIG. 10B, the angle θ1 indicating the inclination of the line L11 is + 30 °, and the angle θp1 indicating the skew of the paper P is −40 °. In this case, the rotation amount of the head unit 10 is calculated as +10 by calculating-(30-40). That is, the head unit 10 is rotated clockwise by 10 ° about the θ rotation shaft 13.

  Next, the head position adjustment unit 94 moves each head unit 10, 20 based on the movement amount in the width direction and the rotation amount of each head unit 10, 20 calculated by the head movement amount calculation unit 93. By this movement, the head units 10 and 20 are adjusted so as to be positioned at appropriate positions.

Next, the receiving unit 97 receives measurement position information 97j indicating the position of the test pattern on the paper P measured by the user from the user via an operation unit (not shown).
The storage unit 98 is a non-volatile memory in which information is held even in a non-energized state, and stores conveyance information 98j indicating the conveyance state of the paper P calculated by the conveyance information calculation unit 92.
Here, since the storage unit 98 is a nonvolatile memory, the user can measure the position of the test pattern after printing the test pattern on the paper P and then turning off the power of the inkjet printer 100. In the case where the inkjet printer 100 is turned on and the user continuously prints a test print, measures the position of the test pattern, and inputs the measurement position information 97j, the storage unit 98 is a volatile memory such as a RAM. There may be.

Next, an operation for printing a test pattern from the head units 10 and 20 will be described.
FIG. 11 is a flowchart showing an operation for printing a test pattern. The operation shown in the figure is started when the paper P to be printed is transported onto the transport surface 50.

  First, in step S <b> 10, the control unit 90 controls the edge sensors S <b> 1 to S <b> 4 on the head unit 10 disposed on the transport surface 50 to start the detection operation of each sensor.

  In step S <b> 20, the control unit 90 causes the test pattern recording unit 91 to print the line L <b> 11 from the head unit 10 as a test pattern on the paper P being transported on the transport surface 50.

  In step S30, the control unit 90 causes the conveyance information calculation unit 92 to calculate the positional deviation amount and the skew amount of the paper P when the line L11 is printed based on the detection results of the edge sensors S1 to S4. Specifically, the positional deviation amount and the skew amount of the paper P are calculated based on the positions of the end portions in the width direction of the paper P detected by the edge sensors S1 to S4. Then, the calculated positional deviation amount and skew amount of the paper P are stored in the storage unit 98 as the conveyance information 98j when the line L11 is printed.

  In step S <b> 40, the control unit 90 controls the edge sensors S <b> 5 to S <b> 8 on the head unit 20 disposed on the transport surface 50 to start the detection operation of each sensor.

  In step S50, the control unit 90 causes the test pattern recording unit 91 to print the line L21 as a test pattern from the head unit 20 on the sheet P being conveyed on which the line L11 is printed.

  In step S60, the control unit 90 causes the conveyance information calculation unit 92 to calculate the positional deviation amount and the skew amount of the paper P when the line L21 is printed based on the detection results of the edge sensors S5 to S8. Specifically, the positional deviation amount and the skew amount of the paper P are calculated based on the position of the edge in the width direction of the paper P detected by each of the edge sensors S5 to S8. Then, the calculated positional deviation amount and skew amount of the paper P are stored in the storage unit 98 as the conveyance information 98j when the line L21 is printed.

  Thus, the operation for printing the test pattern from the head units 10 and 20 is completed.

Next, an operation of receiving the test pattern measurement position information 97j from the user and correcting the positions of the head units 10 and 20 will be described.
FIG. 12 is a flowchart showing an operation of correcting the head units 10 and 20 after receiving the measurement position information 97j of the test pattern. The operation shown in FIG. 11 is performed when the user measures the positions of the test pattern lines L11 and L21 on the paper P printed in the operation of the flowchart shown in FIG. 11 and inputs the measurement position information 97j from the operation unit. Be started.

  First, in step S110, the accepting unit 97 accepts measurement position information 97j indicating the positions of the lines L11 and L21 on the paper P whose position has been measured by the user from the user.

  In step S120, the control unit 90 causes the head movement amount calculation unit 93 to use the measurement position information 97j received in step S110 and the positional deviation amount and skew of the paper P included in the conveyance information 98j stored in the storage unit 98. The head movement amount is calculated based on the line amount. This head movement amount includes the movement amount in the width direction Y of each head unit 10, 20 and the rotation amount about the θ rotation shaft 13.

  In step S130, the control unit 90 performs correction in the conveyance width direction Y for each head unit 10 and 20 having a positional deviation or inclination based on the head movement amount calculated in step S120 by the head position adjustment unit 94. The width direction movement correction and the rotation correction about the θ rotation axis 13 are performed. As a result of this correction, the head units 10 and 20 are positioned at appropriate positions.

  The test pattern recording process corresponds to steps S20 and S50 shown in the flowchart of FIG. The detection step corresponds to the detection operation of each sensor in steps S20 and S50. The conveyance information calculation process corresponds to steps S30 and S60. The storage process corresponds to the operation of storing the conveyance information 98j in the storage unit 98 in steps S30 and S60. The head position adjustment process corresponds to steps S120 and S130 shown in the flowchart of FIG.

In the inkjet printer 100 of the present embodiment, when a test pattern is printed on the paper P from the head units 10 and 20, the positional deviation amount and skew amount of the paper P are calculated and stored in the storage unit 98. Thereafter, the measurement position information 97j of the test pattern of the paper P whose position is measured by the user is received, and each head unit 10 is based on the measurement position information 97j and the stored positional deviation amount and skew amount of the paper P. , 20 is subjected to width direction movement correction and rotation correction.
As a result, when each head unit 10 and 20 prints a test pattern, if a positional deviation and skew have occurred on the paper P, the influence of the positional deviation and skew of the paper P from the measurement position information 97j of the test pattern. Can be subtracted to correct movement and rotation of the head units 10 and 20 in the width direction. Then, highly accurate alignment adjustment can be performed on each head unit 10, 20, and the landing position accuracy of ink droplets ejected from each head unit 10, 20 can be increased. As a result, it is possible to obtain a high-quality printed matter with high image position accuracy with respect to the paper and realizing an image quality without color misregistration.

(Second Embodiment)
Next, the inkjet printer 100 according to the second embodiment will be described.
In the inkjet printer 100 according to the first embodiment described above, both the head units 10 and 20 are adjusted so as to be positioned at appropriate positions. On the other hand, in the inkjet printer 100 according to the second embodiment, the head unit 10 has been adjusted to an appropriate position, and the head unit 20 is adjusted to be positioned at an appropriate position according to the head unit 10.
The ink jet printer 100 according to the second embodiment has the same configuration as that of the ink jet printer 100 according to the first embodiment. However, the test pattern content and printing operation to be printed on the paper P, and information on the test pattern received from the user Is different.

  13 and 14 are diagrams illustrating examples of test patterns to be printed in the second embodiment. FIG. 13 shows a test pattern for correcting misalignment, and FIG. 14 shows a test pattern for correcting tilt. In FIG. 13 and FIG. 14, five lines L11 from the head unit 10 are printed on the paper P as the first test pattern, and five lines L21 from the head unit 20 are printed on the paper P as the second test pattern. ing. These are a set of adjacent lines L11 and L21, and a total of five sets of lines L11 and L21 are printed. In addition, an identification number serving as identification information for identifying each group is printed above the lines L11 and L21 of each group.

Next, an operation for printing a test pattern for correcting misalignment from the head units 10 and 20 will be described.
FIG. 15 is a flowchart illustrating an operation of printing a test pattern for correcting misalignment. The operation shown in the figure is started when the paper P to be printed is transported onto the transport surface 50.

  First, in step S210, the control unit 90 moves the head unit 20 to the start position in the transport width direction Y. This start position is a start position when the head unit 20 is finely adjusted in the transport width direction Y. In the example of FIG. 13, this is the start position of the head unit 20 when printing the line L <b> 21 with the identification number 1. Here, the head unit 20 is finely adjusted in the direction opposite to the conveyance width direction Y.

  In step S220, the control unit 90 controls the upstream edge sensors S1 and S2 of the head unit 10 and the upstream edge sensors S5 and S6 of the head unit 20 that are disposed on the transport surface 50. Start the detection operation of the sensor.

  In step S230, the control unit 90 causes the conveyance information calculation unit 92 to calculate the positional deviation amount of the paper P before the paper P is conveyed directly below the head unit 10 based on the detection results of the edge sensors S1 and S2. calculate.

  In step S240, the control unit 90 causes the head position adjustment unit 94 to move the head unit 10 to a position shift of the paper P when the paper P has a position shift based on the position shift amount of the paper P calculated in step S230. The width direction movement correction is performed at a position corresponding to the amount.

  In step S250, the control unit 90 prints the line L11 as the first test pattern from the head unit 10 corrected in step S240 on the sheet P being conveyed on the conveyance surface 50 by the test pattern recording unit 91. To do. Furthermore, the identification number of the line L11 is also printed. In the example of FIG. 13, the identification number is printed above the line L11.

  In step S260, the control unit 90 causes the conveyance information calculation unit 92 to calculate the positional deviation amount of the sheet P before the sheet P is conveyed directly below the head unit 20 based on the detection results of the edge sensors S5 and S6. calculate.

  In step S270, the control unit 90 causes the head position adjustment unit 94 to move the head unit 20 to the positional deviation of the paper P when the paper P has a positional deviation based on the positional deviation amount of the paper P calculated in step S260. The width direction movement correction is performed at a position corresponding to the amount.

  In step S280, the control unit 90 prints the line L21 as the second test pattern from the head unit 20 corrected in step S270 on the sheet P being conveyed on the conveyance surface 50 by the test pattern recording unit 91. To do. The line L21 here is printed at a position adjacent to the line L11 printed in step S250. The identification number printed in step S250 is a number that identifies adjacent lines L11 and L21 as one set.

  In step S290, the controller 90 identifies the identification number of the set of lines L11 and L21 printed in steps S250 and S280, and the position information in the transport width direction Y of the head unit 20 when the line L21 is printed in step S280. Is stored in the storage unit 98.

  In step S300, the control unit 90 finely moves the head unit 20 in the transport width direction Y by the head position adjustment unit 94. This fine adjustment movement of the head unit 20 is a movement for gradually shifting the position of the line L21 printed on the paper P in the transport width direction Y.

In step S310, the control unit 90 determines whether or not the lines L11 and L21 serving as test patterns have been printed a predetermined number of times. In the example of FIG. 13, it is determined whether or not five sets of lines L11 and L21 have been printed.
If printing has been performed a predetermined number of times, the operation for printing the test pattern is terminated.
On the other hand, if it has not been printed a predetermined number of times, the process returns to step S230, and an operation for printing the next set of test patterns is performed.

Next, an operation for receiving the test pattern identification number from the user and correcting the position of the head unit 20 will be described.
FIG. 16 is a flowchart showing an operation of correcting the head unit 20 after receiving the test pattern identification number. In the operation shown in the figure, the user views each set of lines L11 and L21 printed in the operation of the flowchart shown in FIG. 15, and the user inputs the identification number of the set having the most appropriate positional relationship from the operation unit. Will start when you do.

First, in step S410, the receiving unit 97 receives the test pattern identification number input by the user.
Here, the user inputs the identification number of the test pattern in which the positions of the lines L11 and L21 are not most misaligned in the transport width direction Y from among the sets of test patterns. In the example of FIG. 13, since the positions of the lines L11 and L21 of the set of identification number 3 are not most displaced, the user inputs the identification number 3.

  In step S420, the control unit 90 causes the head movement amount calculation unit 93 to determine the head corresponding to the identification number received in step S410 from the identification number of each set stored in the storage unit 98 and the position information of the head unit 20. The position information of the unit 20 is searched. Then, a head movement amount for positioning the current head unit 20 at the position in the transport width direction Y indicated by the searched position information of the head unit 20 is calculated. The head movement amount includes the width direction movement amount of the head unit 20 in the conveyance width direction Y.

  In step S430, the control unit 90 causes the head position adjustment unit 94 to perform a width direction movement correction that is a correction in the transport width direction Y on the head unit 20 based on the head movement amount calculated in step S420. As a result of this correction, the head unit 20 is positioned at an appropriate position in the transport width direction Y corresponding to the head unit 10.

Next, an operation of printing a test pattern for tilt correction from the head units 10 and 20 will be described.
FIG. 17 is a flowchart showing an operation for printing a test pattern for inclination correction. The operation shown in the figure is started when the paper P to be printed is transported onto the transport surface 50.

  First, in step S510, the control unit 90 moves to a start position when the head unit 20 is rotated. This start position is a start position when the head unit 20 is fine-adjusted and rotated. In the example of FIG. 14, the start position is the position of the head unit 20 when the line L21 of the group having the identification number 1 is printed.

  In step S520, the control unit 90 controls the edge sensors S1 and S2 on the upstream side of the head unit 10 and the edge sensors S5 and S6 on the upstream side of the head unit 20 that are disposed on the conveyance surface 50. Start the detection operation of the sensor.

  In step S530, the control unit 90 causes the conveyance information calculation unit 92 to determine the skew amount of the sheet P before the sheet P is conveyed directly below the head unit 10 based on the detection results of the edge sensors S1 and S2. calculate.

  In step S540, the control unit 90 causes the head position adjustment unit 94 to move the head unit 10 to the skew of the paper P when the paper P is skewed based on the skew amount of the paper P calculated in step S530. Rotation correction is performed at a position corresponding to the amount.

  In step S550, the control unit 90 prints the line L11 as the first test pattern from the head unit 10 corrected in step S540 on the paper P being conveyed on the conveyance surface 50 by the test pattern recording unit 91. To do. Furthermore, the identification number of the line L11 is also printed. In the example of FIG. 14, the identification number is printed above the line L11.

  In step S560, the control unit 90 causes the conveyance information calculation unit 92 to determine the skew amount of the sheet P before the sheet P is conveyed directly below the head unit 20 based on the detection results of the edge sensors S5 and S6. calculate.

  In step S570, the control unit 90 causes the head unit 20 to skew the paper P when the paper P is skewed based on the skew amount of the paper P calculated in step S560 by the head position adjustment unit 94. Rotation correction is performed at a position corresponding to the amount.

  In step S580, the control unit 90 prints the line L21 as the second test pattern from the head unit 20 corrected in step S570 on the sheet P being conveyed on the conveyance surface 50 by the test pattern recording unit 91. To do. The line L21 here is printed at a position adjacent to the line L11 printed in step S550. The identification number printed in step S550 is a number that identifies adjacent lines L11 and L21 as one set.

  In step S590, the control unit 90 stores the identification number of the pair of lines L11 and L21 printed in steps S550 and S580 and angle information indicating the inclination of the head unit 20 when the line L21 is printed in step S580. Stored in section 98.

  In step S600, the control unit 90 finely rotates the head unit 20 by the head position adjustment unit 94. The fine adjustment rotation of the head unit 20 is a movement for rotating the position of the line L21 printed on the paper P little by little. In the example of FIG. 14, the head unit 20 is finely adjusted and rotated in the clockwise direction.

In step S610, the control unit 90 determines whether or not the lines L11 and L21 serving as test patterns have been printed a predetermined number of times. In the example of FIG. 14, it is determined whether or not five sets of lines L11 and L21 have been printed.
If printing has been performed a predetermined number of times, the operation for printing the test pattern is terminated.
On the other hand, if it has not been printed a predetermined number of times, the process returns to step S530, and an operation for printing the next set of test patterns is performed.

Next, an operation for receiving the test pattern identification number from the user and correcting the position of the head unit 20 will be described.
FIG. 18 is a flowchart showing the operation of correcting the head unit 20 after receiving the test pattern identification number. The operation shown in the figure is started when the user views each set of test patterns printed in the operation of the flowchart shown in FIG. 17 and the user inputs the identification number of the test pattern from the operation unit.

First, in step S710, the receiving unit 97 receives a test pattern identification number input by the user.
Here, the user inputs the identification number of the test pattern in which the positions of the lines L11 and L21 are most parallel to each other among the test patterns of each set. In the example of FIG. 14, since the lines L11 and L21 of the set of identification number 3 are the most parallel to each other, the user inputs the identification number 3.

  In step S720, the control unit 90 uses the head movement amount calculation unit 93 to determine the head corresponding to the identification number received in step S710 from the identification number of each set stored in the storage unit 98 and the angle information of the head unit 20. The angle information of the unit 20 is searched. Then, a head movement amount for positioning the current head unit 20 at the position indicated by the searched angle information of the head unit 20 is calculated. The head movement amount includes a rotation amount around the θ rotation axis 13 with respect to the head unit 20.

  In step S730, the control unit 90 causes the head position adjustment unit 94 to perform rotation correction about the θ rotation axis 13 with respect to the head unit 20 based on the head movement amount calculated in step S720.

In the inkjet printer 100 of the present embodiment, the lines L11 and L21 that form each set are printed on the paper P together with the identification numbers from the head units 10 and 20. At this time, the head unit 20 is finely moved in the transport width direction Y to print the line L21, and the identification number at that time and the position information of the head unit 20 in the transport width direction Y are stored in the storage unit 98. After that, the identification number of the set of the lines L11 and L21 that are most misaligned input by the user is received, and the movement in the width direction is corrected with respect to the head unit 20 based on the positional information of the head unit 20 corresponding to this identification number. I do.
Thereby, the head unit 20 can be positioned in the most appropriate positional relationship with the head unit 10 in the conveyance width direction Y. Then, it is possible to perform highly accurate alignment adjustment in the transport width direction Y with respect to the head units 10 and 20.

Further, when printing the lines L11 and L21 of each set together with the identification number from the head units 10 and 20 on the paper P, the head unit 20 is finely rotated in the transport width direction Y to print the line L21. And the angle information of the head unit 20 are stored in the storage unit 98. Thereafter, the identification number of the most parallel line L11, L21 input by the user is received, and rotation correction is performed on the head unit 20 based on the angle information of the head unit 20 corresponding to this identification number.
Thereby, the arrangement angle of the head unit 20 on the transport surface 50 can be positioned in the most appropriate positional relationship with the head unit 10. Then, it is possible to perform highly accurate alignment adjustment on each of the head units 10 and 20 at the arrangement angle on the transport surface 50.

  Further, since the user only has to see the positional relationship between the lines L11 and L21 of each set printed on the paper P, and the work of measuring the positions of the lines L11 and L21 on the paper P is unnecessary, the head unit 20 On the other hand, alignment adjustment can be easily performed at an appropriate position according to the head unit 10.

(Modification)
In the above-described embodiment, as shown in FIG. 1 and the like, one common transport unit 1 is provided for the two head units of the head units 10 and 20. However, the present invention is not limited to this. For example, as shown in a side sectional view schematically showing the outline of the ink jet printer 300 in FIG. 19, a tandem type in which a transport unit 1 is provided as an independent mechanism for each of the head units 10 and 20. It may be configured as follows.

  In the first embodiment, the plurality of ejection heads 11 are divided and arranged by the two head units 10 and 20. However, the present invention is not limited to this, and the inkjet printer includes only one head unit. A configuration may be adopted in which all the ejection heads are arranged in the head unit.

  DESCRIPTION OF SYMBOLS 1 ... Conveyance part, 2 ... Printing part, 10, 20 ... Head unit, 13 ... (theta) rotating shaft, 14 ... Y-axis motor, 15 ... (theta) axis motor, 31 ... Gate roller, 32 ... Driven roller, 33 ... Tension roller, 34 ... Driving roller, 35 ... Endless belt, 36 ... Conveyance drive motor, 37 ... Vent hole, 50 ... Conveyance surface, 90 ... Control unit, 91 ... Test pattern recording unit, 92 ... Conveyance information calculation unit, 93 ... Head movement amount Calculation unit, 94: Head position adjustment unit, 97: Reception unit, 97j: Measurement position information, 98: Storage unit, 98j: Transport information, 100, 300: Inkjet printer, L01: Reference line, L11, L21 ... Line, P ... paper, S1 to S8 ... edge sensors, T11, T12, T21, T22 ... line ends.

Claims (6)

A test pattern recording step for recording a test pattern on the recording medium from a head unit for recording by jetting liquid onto the recording medium conveyed on the conveying surface;
A detection step of detecting a position of the transported recording medium when the test pattern is recorded on the recording medium in the test pattern recording step;
A conveyance information calculation step for calculating conveyance information indicating a conveyance state of the recording medium based on the position of the recording medium detected in the detection step;
A storage step for storing the conveyance information calculated in the conveyance information calculation step;
Based on the conveyance information stored in the storage step and the measurement position information indicating the measurement result of the test pattern position recorded on the recording medium, the head unit is moved in a direction parallel to the conveyance surface. And a head position adjusting step for correcting a positional deviation of the head unit. The transport information includes a positional deviation amount of the recording medium from a predetermined reference position in the width direction of the recording medium on the transport surface,
The head unit position adjustment method according to claim 1, wherein the measurement position information includes a positional deviation amount of the test pattern from a predetermined reference position in the width direction of the recording medium in the recording medium.   In the head position adjusting step, the amount of displacement in the width direction of the head unit is calculated based on the amount of displacement of the recording medium and the amount of displacement of the test pattern, and according to the calculated amount of movement in the width direction, The head unit position adjusting method according to claim 2, wherein the head unit is moved in a direction intersecting a conveyance direction of the recording medium. The transport information includes a skew amount of the recording medium on the transport surface,
4. The head unit position adjustment method according to claim 1, wherein the measurement position information includes an inclination amount of the test pattern in the recording medium. 5.   In the head position adjusting step, the rotation amount of the head unit is calculated based on the skew amount of the recording medium and the inclination amount of the test pattern, and the head unit is moved according to the calculated rotation amount. The head unit position adjusting method according to claim 4, wherein the head unit position is rotated about an axis perpendicular to the transport surface.   6. A recording apparatus, wherein the position of the head unit is adjusted by the head unit position adjusting method according to any one of claims 1 to 5.

Images