JP2011183723A - Method for inspecting nozzle array arrangement, and method for adjusting head mounting position - Google Patents

Abstract

A head mounting error is determined, and a decrease in ejection accuracy due to the mounting error is efficiently and easily suppressed.
A unit patch 41 is constituted by a reference patch 42 printed by a reference nozzle row 15A and a comparison patch 43 printed by a comparison nozzle row 15B, and a plurality of print intervals L between two patches are made different by unit amounts. A pair of unit patches 41 is printed. The plurality of pairs of unit patch groups printed on the reference nozzle row 15A and the comparison nozzle row 15B one by one at the head front end, center, and rear end portions are referred to as a head attachment position adjustment pattern 40. From the printed head attachment position adjustment pattern 40, unit patches 41 having no white or black stripes between two patches are visually discriminated, and the nozzle row intervals at the head front end, center and rear end positions are determined. Based on the nozzle row spacing at each position, the inclination and the amount of parallel movement of the comparison nozzle row 15B are grasped, and the mounting position of the head provided with the comparison nozzle row is adjusted.
[Selection] Figure 5

Description

  The present invention relates to a method for inspecting the arrangement of a plurality of nozzle rows provided in a liquid discharge head, and a head mounting position in a liquid (droplet) discharge apparatus having a liquid discharge head unit in which the plurality of heads are unitized. It relates to the adjustment method.

  As an example of a liquid ejecting apparatus, in an ink jet printer, a plurality of nozzle rows are provided in a head, and color printing is performed by ejecting different colors of ink from each nozzle row. The print data for printing with such an ink jet printer is generated on the assumption that nozzle rows in which nozzles are arranged in the arrangement direction as designed are arranged at intervals as designed. For this reason, when the arrangement of nozzle rows in the head is deviated from the design position due to head manufacturing errors or mounting errors, the dot formation position is deviated from the position designated by the print data. In color printing, if the positional accuracy of dots formed by each nozzle row is low, the color overlay accuracy of each color ink is lowered, and image quality degradation such as color unevenness occurs.

  In Patent Document 1, the inclination of a nozzle row caused by a head manufacturing error or mounting error is detected by printing a predetermined inclination detection pattern (θ position adjustment pattern), and the dot row inclination correction (θ correction) is performed. It is described. In this inclination correction, the print data is corrected so as to shift the ink ejection position by an amount that cancels the detected inclination. Then, printing for detecting a positional deviation in the main scanning direction (X direction) between the nozzle rows is performed using the inclination corrected print data, and a positional deviation in the main scanning direction is detected from the printing result. Dot position correction (X correction) in the scanning direction is performed. Similarly, dot position correction (Y correction) in the sub-scanning direction (Y direction) is performed.

  In the tilt detection pattern of Patent Document 1, dot rows are formed by the nozzles on one end side and the other end side of the nozzle row, respectively, and when the nozzle row is tilted with respect to the reference direction, there is a gap or overlap between the dot rows. This is what happens. In this inclination detection pattern, the gap between the dot rows is recognized as a white stripe, and the overlap between the dot rows is recognized as a black stripe, so that the presence or absence and the amount of the gap or overlap can be easily determined visually. . In Patent Document 1, by drawing a plurality of dot rows in which only the dot formation position by the nozzle on one end side of the row is changed one dot at a time, and detecting a dot row in which neither white stripes nor black stripes are formed, The inclination amount of the nozzle row can be easily determined visually.

JP 2007-38662 A

  In a head unit in which a plurality of heads are unitized and a nozzle row is provided for each head, it is necessary to consider the mounting error of other heads with respect to the reference head as a head unit manufacturing error that affects the color overlay accuracy of ink. . In order to efficiently and accurately adjust the mounting position of the other head with respect to the reference head to eliminate the decrease in color overlay accuracy due to manufacturing errors, the relative distance and inclination of the other head with respect to the reference head are set. It is necessary to grasp the appropriate adjustment amount. In particular, if the relative distance and inclination between nozzle rows provided in different heads are accurately detected, the adjustment amount of the head mounting position can be determined more appropriately according to the data.

  Japanese Patent Application Laid-Open No. 2004-151561 describes a method of detecting an inclination of a nozzle row by printing an inclination detection pattern. However, the tilt detection method of Patent Document 1 detects a difference in ejection position between the nozzles at one end and the nozzles at the other end in a single nozzle row, and thereby detects the tilt of the nozzle row alone with respect to the reference direction. is there. Therefore, the relative inclination between the plurality of nozzle rows cannot be detected by a single detection operation. Japanese Patent Application Laid-Open No. H10-228561 also describes detecting a positional deviation in the main scanning direction corresponding to a relative distance between nozzle rows. However, it is assumed that this detection method is performed using print data whose inclination has been corrected. Therefore, the distance between the nozzle rows and the relative inclination cannot be detected efficiently, and the adjustment amount of the head mounting position cannot be determined efficiently.

  In view of this point, an object of the present invention is to detect the relative inclination between nozzle rows or the interval between nozzle rows efficiently and easily, and based on this, affects the color overlay accuracy of ink. Proposed are a nozzle row arrangement inspection method and a head attachment position adjustment method that can efficiently and easily determine an adjustment amount of nozzle arrangement or head attachment position to eliminate head unit manufacturing errors. There is.

In order to solve the above problem, the present invention is a nozzle row arrangement inspection method in a head unit including a plurality of heads having nozzle rows,
Select a reference nozzle row and a comparison nozzle row from nozzle rows with different heads,
In the reference nozzle row and the comparison nozzle row, set an arrangement position of at least a part of the nozzle arrangement direction,
Using the nozzles at the arrangement positions in the reference nozzle row and the comparison nozzle row, a reference pattern discharged by the nozzles of the reference nozzle row and a comparison pattern discharged by the nozzles of the comparison nozzle row at a predetermined discharge interval. A plurality of pairs of unit test patterns arranged side by side, with the target value of the discharge interval being different by a predetermined unit amount,
Based on a target value of the discharge interval in a specific unit test pattern in which the reference pattern and the comparison pattern have a specific discharge interval among the plurality of pairs of unit test patterns that have been discharged, A nozzle row interval that is a relative distance between a reference nozzle row and the comparison nozzle row is determined.

  As described above, the present invention can determine the relative distance (nozzle row interval) between the reference nozzle row and the comparison nozzle row by discriminating a specific unit inspection pattern. Therefore, the adjustment amount of the mounting position of the plurality of heads provided with each nozzle row can be determined efficiently and easily.

In order to solve the above problem, the present invention is a nozzle row arrangement inspection method in a head unit including a plurality of heads having nozzle rows,
Select a reference nozzle row and a comparison nozzle row from nozzle rows with different heads,
In the reference nozzle row and the comparison nozzle row, set at least a first position and a second position separated from each other in the nozzle arrangement direction,
Using the nozzles at the first position in the reference nozzle row and the comparison nozzle row, a reference pattern discharged by the nozzles in the reference nozzle row and a comparison pattern discharged by the nozzles in the comparison nozzle row are set to a predetermined discharge interval. A plurality of pairs of unit test patterns arranged side by side with a target value of the discharge interval being varied by a predetermined unit amount,
Based on a target value of the discharge interval in a specific unit inspection pattern in which the reference pattern and the comparison pattern have a specific discharge interval among the plurality of pairs of unit inspection patterns that have been discharged, the first position Determining a nozzle row interval which is a relative distance between the reference nozzle row and the comparison nozzle row;
Using the nozzles at the second position in the reference nozzle row and the comparison nozzle row, the plurality of pairs of unit test patterns are ejected, and the specific unit test pattern in the plurality of pairs of unit test patterns that have been ejected Determining the nozzle row interval at the second position based on the target value of the discharge interval in
A relative inclination between the reference nozzle row and the comparison nozzle row is determined based on a difference between the nozzle row intervals at the first position and the second position.

  As described above, the present invention can determine the relative distance (nozzle row interval) between the reference nozzle row and the comparison nozzle row by discriminating a specific unit inspection pattern. Further, the nozzle row interval can be determined at two positions apart from each other in the nozzle row, and the relative inclination between the reference nozzle row and the comparison nozzle row can be determined. That is, in the example of the inkjet head, the manufacturing error of the head unit that affects the color superimposition accuracy of the ink can be accurately grasped by printing a predetermined print pattern and determining the print result. Accordingly, it is possible to efficiently and easily determine the adjustment amount of the nozzle arrangement for suppressing the deterioration of the ink color overlay accuracy or the adjustment amount of the mounting positions of the plurality of heads provided with the respective nozzle rows. .

  In the present invention, for each discharged unit test pattern, it is desirable that a unit test pattern in which neither a gap nor an overlap between the reference pattern and the comparison pattern is formed be the specific unit test pattern. In each unit inspection pattern, a gap between patterns is recognized as a white stripe, and an overlap between patterns is recognized as a dark stripe (black stripe). The presence or absence of such white stripes and black stripes can be determined very easily and accurately even by visual determination. Therefore, according to this method, it is extremely easy to determine the nozzle row interval and determine the adjustment amount of the nozzle arrangement based on this, or the adjustment amount of the mounting position of the head provided with each nozzle row, and It can be performed with high accuracy.

  In the present invention, the head unit is mounted on a carriage, scanned at least a plurality of times in a scanning range that passes through the first scanning position and the second scanning position, and at each first scanning, A pair of unit test patterns are ejected using the nozzles at the first position, and a pair of unit test patterns are ejected using the nozzles at the second position at the second scanning position. By changing the target value of the ejection interval for ejecting the inspection pattern by a predetermined unit amount, the plurality of pairs of the nozzles at the first position and the second position at the completion of the plurality of scans. The discharge of the unit inspection pattern can be completed. In this way, the ejection for inspection including all the unit test patterns necessary for determining the nozzle row interval for at least two positions on the nozzle row by a series of ejection operations while scanning the head unit a plurality of times. A pattern can be formed efficiently.

Next, the present invention is a head mounting position adjusting method in a head unit having a plurality of heads,
The plurality of heads include at least a first head provided with a reference nozzle row and a second head provided with a comparison nozzle row,
The nozzle row arrangement inspection method is performed by making the arrangement direction of the first head and the second head coincide with the increase / decrease direction of the ejection interval, whereby the first position and the second position are Determine the nozzle row spacing,
Based on the determination result, an attachment position adjustment amount of the second head with respect to the first head is determined.

  According to the present invention, in the head unit configured by assembling a plurality of heads, the head manufacturing error, specifically, the relative inclination and the head interval between the plurality of heads can be grasped. Then, based on the grasped inclination and positional deviation, the adjustment amount of the head mounting position for suppressing the decrease in ejection accuracy can be determined efficiently and easily.

  In the present invention, the first position is a position on one end side in the nozzle arrangement direction, the second position is a position on the other end side in the nozzle arrangement direction, and the nozzle row in the first position and the second position. Based on the difference in spacing, the tilt adjustment amount of the second head with respect to the first head is determined, and only the nozzle at the third position located between the first position and the second position in each head is used. The plurality of sets of unit test patterns are discharged, the specific unit test pattern is detected from the plurality of pairs of unit test patterns that have been discharged, and the target value of the discharge interval in the discharge of the specific unit test pattern is set. Based on the determination result, the nozzle row interval at the third position is determined, and based on the determination result, the parallel movement amount of the second head in the head array direction relative to the first head is determined. Desirable. In this way, tilt adjustment by rotation of the head and position adjustment in the head arrangement direction by parallel movement of the head can be easily performed.

  In the present invention, the third position is a central position in the nozzle arrangement direction, and the head unit is scanned a plurality of times in a scanning range passing through the first scanning position, the second scanning position, and the third scanning position. Each time scanning is performed, a pair of unit inspection patterns are ejected using only the nozzles on one end side at the first scanning position, and only the central nozzle is used at the second scanning position. A pair of unit test patterns are discharged, and at the third scan position, a pair of unit test patterns are discharged using only the nozzles on the other end side, and the unit test patterns are discharged in each scan. By changing the target value of the discharge interval for each unit amount, the multiple scans are completed and the multiple nozzles on the one end side, the center, and the other end side are used. It is desirable to complete the discharge of the unit test pattern pairs. In this way, a unit test pattern for determining the nozzle row interval at each position on one end side, center, and other end side of the nozzle row is obtained by a series of ejection operations while the head unit is scanned a plurality of times. It is possible to efficiently form a discharge pattern for inspection including all of them.

  According to the present invention, the manufacturing error of the head unit can be accurately grasped only by forming a predetermined ejection pattern and determining the ejection result. Therefore, in the example of the ink jet head, the adjustment amount of the nozzle arrangement for suppressing the deterioration of the color superimposition accuracy of the ink or the adjustment amount of the mounting position of the plurality of heads provided with each nozzle row can be efficiently and easily performed. Can be determined.

It is a perspective view which shows schematic structure of the printer mechanism part of an inkjet printer. It is explanatory drawing which looked at the inkjet head from the nozzle surface. It is a block diagram which shows schematic structure of the control system of an inkjet printer. It is explanatory drawing of the distance between heads and the relative inclination of a head. It is explanatory drawing of the pattern for a head attachment position adjustment, and its printing method. It is an example of the printing result of the pattern for a head attachment position adjustment. It is explanatory drawing of the pattern for head attachment position adjustment of the modification.

  Hereinafter, embodiments of a nozzle row arrangement inspection method and a head unit mounting position adjustment method to which the present invention is applied will be described with reference to the drawings, taking an ink jet printer as an example of a liquid ejecting apparatus.

(Overall configuration of inkjet printer)
FIG. 1 is a perspective view illustrating a schematic configuration of a printer mechanism unit of an ink jet printer. The ink jet printer 1 performs color printing on a long recording paper fed out from a roll paper using a plurality of types of color inks, and includes a printer case 2 having a rectangular parallelepiped shape as a whole, and a printer mechanism therein. Part 10 is provided. A roll paper storage unit is formed in the center of the printer mechanism unit 10. When the opening / closing lid 5 is opened, the roll paper storage unit opens forward, and the roll paper can be replaced.

  On the upper side of the roll paper storage unit, a platen 12 that defines a printing area is bridged in the printer width direction. On the upper side of the platen 12, a carriage 14 on which an inkjet head 13 (head unit) having a nozzle surface facing downward is mounted is disposed. The carriage 14 is moved away from the home position HP (position indicated by a solid line in FIG. 1) from the platen 12 along the carriage guide shaft 14a extending in the width direction of the printer. It reciprocates between (the position indicated by the imaginary line in FIG. 1).

  An ink cartridge mounting portion 8 is provided on the left side of the opening / closing lid 5, and an ink cartridge 9 is mounted on the ink cartridge mounting portion 8. An ink supply path 18 extending in the vertical direction is provided at a portion on the rear end side of the ink cartridge mounting portion 8, and the ink supply path 18 and the inkjet head 13 are connected via a flexible ink tube 17. The ink cartridge 9 is provided with an ink tank that stores a plurality of colors of ink, for example, magenta, yellow, cyan, and black. The number of ink colors is not limited to four, and may be five or more or three or less. The ink supply path 18 and the flexible ink tube 17 constitute an ink supply path for supplying a plurality of colors of ink from each ink tank to the inkjet head 13. When the carriage 14 returns to the home position HP, the pump unit provided in the inkjet head 13 operates. As a result, ink is supplied from the ink tank in the ink cartridge 9 to the flow path in the head of the inkjet head 13 via the ink supply path.

(Head unit)
FIG. 2 is an explanatory view of the ink jet head viewed from the nozzle surface side. The inkjet head 13 is a head unit in which a plurality of heads 13 (1) to 13 (n) are arranged and mounted in the head scanning direction (X direction in FIG. 2) that is the moving direction of the carriage 14. The head 13 (1) is located on the right end side in the printer width direction, and the head 13 (n) is located on the print area side. Each of the heads 13 (1) to 13 (n) is provided with nozzle rows 15 (1) to 15 (n) arranged in a direction orthogonal to the head scanning direction.

  The number of heads constituting the inkjet head 13 can be set to a number corresponding to the number of colors of ink supplied from the ink cartridge 9, for example. In this way, in each of the heads 13 (1) to 13 (n), the nozzles provided in the same head are all nozzles that eject the same color ink, and different color inks are supplied from the nozzles of different heads. It can be configured to discharge. Alternatively, the number of heads may be smaller than the number of ink colors, and a plurality of nozzle rows for discharging a plurality of colors of ink may be provided on the same head. As shown in FIG. 2, each nozzle row 15 (1) to 15 (n) is composed of two nozzle rows that are shifted by ½ dot in the nozzle arrangement direction. The arrangement is not limited to such an arrangement and can be changed as appropriate.

(Control system)
FIG. 3 is a block diagram showing a schematic configuration of a control system of the ink jet printer. The control system of the inkjet printer 1 is mainly configured by a control unit 30 having a storage area such as a CPU, ROM, and RAM. The control unit 30 is connected to the host device 31 and the like, and controls each unit of the inkjet printer 1 based on print data and commands received from the host device 31.

  The control unit 30 drives a recording paper transport mechanism (not shown) based on the received print data, and transports the recording paper fed from the roll paper along the surface of the platen 12. Then, in conjunction with this transport operation, the carriage drive mechanism 14b is driven to eject ink from the inkjet head 13 toward the recording paper while scanning the carriage 14, thereby printing on the recording paper. Further, after the printing is completed, the control unit 30 moves the carriage 14 to the home position HP and waits.

  In addition, the control unit 30 includes a head attachment position adjusting unit 32. The head attachment position adjustment means 32 adjusts the head attachment position, which will be described later, based on a command from the host device 31 or an input from an operation unit (not shown) provided in the inkjet printer 1 or a built-in control program. The pattern 40 for printing is printed. The printing of the head attachment position adjustment pattern 40 is performed based on print data stored in advance in a storage area in the control unit 30. Alternatively, it can be performed based on print data received from the host device 31.

(Nozzle arrangement inspection method and head mounting position adjustment method)
FIG. 4 is an explanatory diagram of the distance between the heads and the relative inclination of the heads. In FIG. 4, the rightmost head 13 (1) is used as a reference head, and deviations in the mounting positions of the other heads 13 (2) to 13 (n) with respect to this reference head are shown. In the plurality of heads 13 (1) to 13 (n) constituting the inkjet head 13, the nozzle rows 15 (1) to 15 (n) are arranged at predetermined intervals and are parallel to each other. Designed to be Therefore, the error in the mounting position of each head with respect to the reference head includes the inclination of the other nozzle rows 15 (2) to 15 (n) with respect to the nozzle row 15 (1) provided in the reference head, and the nozzle row 15 (1 ) In the head arrangement direction (X direction, scanning direction) of the other nozzle rows 15 (2) to 15 (n) (difference between the nozzle row interval D and the reference interval D0).

  In a configuration in which different colors of ink are ejected from the nozzles of each head, if there is an error in the mounting position of the heads, the relative arrangement of the nozzle rows provided in each head will not be as designed. In other words, the ink color overlay accuracy during printing is reduced. Therefore, the inclination amount of the nozzle rows 15 (2) to 15 (n) of the other heads with respect to the nozzle row 15 (1) of the reference head and the difference between the nozzle row interval D and the reference interval D0 are grasped, and this difference is eliminated. If the mounting position of the heads 13 (2) to 13 (n) with respect to the head 13 (1) is adjusted as described above, the error in the mounting position can be eliminated. As a result, it is possible to realize a state in which the nozzle rows 15 (1) to 15 (n) are arranged at a preset reference interval and are parallel to each other. Or the discharge timing of each nozzle can be adjusted by the control part 30, and the error of an attachment position can also be eliminated.

  As shown in FIG. 4, when the reference head is the head 13 (1) and the heads to be inspected are the heads 13 (2) to 13 (n), the inclination amount between the nozzle rows is one end side of the nozzle rows. And an angle corresponding to the difference between the nozzle row intervals on the other end side (dimension Δd shown in FIG. 4). Therefore, this inclination can be eliminated by rotating the head by an angle corresponding to the dimension Δd.

  Further, the amount of parallel movement in the head arrangement direction (X direction) remaining after the inclination is eliminated is the difference between the nozzle row interval D and the reference interval D0 at the rotation center position of the head. For example, in the example of FIG. 4, assuming that the inclination is eliminated with the center in the row direction of the nozzle row as the center of rotation, the difference between the nozzle row interval D and the reference interval D0 at this position (dimension ΔD shown in FIG. 4). Is shown. Therefore, if the head is translated in the scanning direction by the dimension ΔD, the remaining mounting error can be eliminated. Thus, the adjustment amount of the mounting position of the other head with respect to the reference head can be determined by measuring the dimension Δd and the dimension ΔD. Therefore, in this embodiment, the nozzle row interval D is detected at each position on one end side, the center, and the other end side of the nozzle row.

  FIG. 5 is an explanatory diagram of a head mounting position adjusting pattern and a printing method thereof. FIG. 5A is an explanatory diagram of the reference head and the inspection target head. In the following description, a reference head and an inspection target head selected from the plurality of heads 13 (1) to 13 (n) are indicated by reference numerals 13A and 13B, respectively. The head attachment position adjustment pattern 40 is printed by the reference nozzle row 15A provided in the reference head 13A and the comparison nozzle row 15B provided in the inspection target head 13B. FIG. 5A shows a state in which the reference head 13A and the inspection target head 13B are arranged such that the nozzle row interval D between the reference nozzle row 15A and the comparison nozzle row 15B becomes the designed reference interval D0.

  The print data for printing the head attachment position adjustment pattern 40 is created according to the combination of the reference head 13A and the inspection target head 13B, and the number of print data corresponding to the number of combinations is prepared. For example, when the head 13 (1) is the reference head 13A and the inspection target head 13B is selected from the heads 13 (2) to 13 (n), n-1 types of print data are prepared.

  FIG. 5B is an explanatory diagram of a head attachment position adjustment pattern. The head attachment position adjustment pattern 40 is used to print a plurality of unit patches 41 (unit inspection patterns) in a matrix in the head scanning direction (X direction) and the recording paper conveyance direction (Y direction). Each unit patch 41 is configured by a combination of a pair of patches including a reference patch 42 (reference pattern) and a comparison patch 43 (comparison pattern).

  FIG. 5C is an explanatory diagram of a unit patch. In each unit patch 41, the reference patch 42 and the comparison patch 43 are printed side by side in the X direction, which is the arrangement direction of the first head 13A and the second head 13B. The reference patch 42 is printed by the reference nozzle row 15A, and the comparison patch 43 is printed by the comparison nozzle row 15B. The print data of the head attachment position adjustment pattern 40 is created so that the reference patch 42 and the comparison patch 43 are printed at a preset print interval L for each unit patch.

  As shown in FIG. 5B, the head mounting position adjustment pattern 40 includes three unit patch groups 40A, 40B, and 40C each including nine pairs of unit patches 41 arranged in the Y direction. Configured. The unit patch groups 40A, 40B, and 40C in three rows are printed by shifting the print position in the Y direction by a predetermined amount, for example, by one unit patch. Nine pairs of unit patches 41 in each of the unit patch groups 40A, 40B, and 40C are printed by changing the printing interval L by a unit amount.

  That is, in each row, among the nine pairs of unit patches 41, the unit patches 411A, 411B, and 411C arranged at one end of the row (upper drawing in FIG. 5B) are between the reference patch 42 and the comparison patch 43. The printing interval L is the largest, and the widest gap 44 is formed between the reference patch 42 and the comparison patch 43. Each unit patch 41 is set such that the printing interval L between the reference patch 42 and the comparison patch 43 is reduced by a unit amount toward the other end (lower side of FIG. 5) of each row.

  In the head mounting position adjusting pattern 40, a gap 44 is formed between the patches from the uppermost unit patch 411A, 411B, 411C to the fourth unit patch 414A, 414B, 414C. It is set so as to decrease by unit amount downward. The fifth unit, that is, the unit patches 415A, 415B, and 415C in the center of each row is printed with the reference patch 42 and the comparison patch 43 just in contact with each other, and the printing interval L is set so as to form one continuous pattern. ing. Then, an overlapping portion 45 is formed in the reference patch 42 and the comparison patch 43 from the sixth unit patch 416A, 416B, 416C of each row to the lowest unit patch 419A, 419B, 419C of each row, and the overlapping width. Is set to increase by unit amount. The unit increase / decrease amount of the printing interval L is set to the size of one printing dot. Note that the unit increase / decrease amount is not limited to the size of one dot, and can be set as appropriate according to the required determination accuracy of the nozzle row interval according to the present method.

  The unit patch groups 40A, 40B, and 40C are printed using different portions of the reference nozzle row 15A and the comparison nozzle row 15B in the nozzle arrangement direction. Specifically, the unit patch group 40A is printed by the nozzles 151A and 151B (the nozzles in the region S1 shown in FIG. 5A) on the head front end side in the reference nozzle row 15A and the comparison nozzle row 15B. The unit patch group 40B is printed by the nozzles 152A and 152B (the nozzles in the region S2 shown in FIG. 5A) at the center of the head in the reference nozzle row 15A and the comparison nozzle row 15B. The unit patch group 40C is printed by the nozzles 153A and 153B (the nozzles in the region S3 shown in FIG. 5A) on the head rear end side in the reference nozzle row 15A and the comparison nozzle row 15B.

  The head attachment position adjusting pattern 40 scans the inkjet head 13 nine times, and each unit scan 41 includes one unit patch 41 constituting each unit patch group 40A, 40B, 40C from one end side of each row. Print pair by pair. At this time, the scanning range of the head is a range including three scanning positions corresponding to the printing positions of the unit patch groups 40A, 40B, and 40C. First, in the first scanning, the unit patch 411A is printed by the nozzles 151A and 151B at the scanning position (first scanning position) corresponding to the printing position of the unit patch group 40A. Subsequently, the unit patch 411B is printed by the nozzles 152A and 152B at the scanning position (second scanning position) corresponding to the printing position of the unit patch group 40B. The unit patch 411C is printed by the nozzles 153A and 153B at the scanning position (third scanning position) corresponding to the printing position of the unit patch group 40C. Similarly, in the second scan, the unit patch 412A is printed by the nozzles 151A and 151B, the unit patch 412B is printed by the nozzles 152A and 152B, and the unit patch 412C is printed by the nozzles 153A and 153B. Thereafter, printing is similarly performed, and printing of the head attachment position adjustment pattern 40 including the three rows × 9 pairs of unit patch groups 40A, 40B, and 40C is completed together with the completion of nine scans.

  The print data for printing the head mounting position adjustment pattern 40 is shown in FIG. 5 when the relative positional relationship between the reference nozzle row 15A and the comparison nozzle row 15B used for printing is as designed. The data is printed in the state shown in (b). Therefore, the difference between the printing interval L between the reference patch 42 and the comparison patch 43 in the actually printed pattern and the printing interval L between the reference patch 42 and the comparison patch 43 in the target pattern shown in FIG. Thus, it can be determined how much the interval between the reference nozzle row 15A and the comparison nozzle row 15B deviates from the designed interval.

  The unit patch groups 40A, 40B, and 40C in the head mounting position adjustment pattern 40 are printed using the nozzles on the head front end side, the head center portion, and the head rear end portion in the reference nozzle row 15A and the comparison nozzle row 15B. Therefore, the print result of each row is a print result reflecting the nozzle row interval D at each position of the front end center and the rear end of the head. Specifically, the printing interval L between the reference patch 42 and the comparison patch 43 in each unit patch group 40A, 40B, 40C is shifted according to the nozzle row interval D in the front end, center, and rear end portions of the nozzle row. Has occurred. In the method of the present embodiment, the unit patch 41 (specific unit) printed so that the reference patch 42 and the comparison patch 43 just touch each other out of nine pairs of unit patches 41 with the printing interval L varied by unit amount. Inspection pattern) is detected. Then, it is determined at which position of the nine pairs the unit patch 41 is the unit patch 41. In the present embodiment, as described above, since the printing interval L is varied by unit amount according to the position of the unit patch 41, based on the position of the unit patch 41 at the position where the reference patch 42 and the comparison patch 43 just touch each other, It can be seen that the reference nozzle row 15A and the comparison nozzle row 15B are shifted by a multiple of the unit amount. The unit amount is preferably a size corresponding to one dot in consideration of overlap.

  The determination of whether or not the reference patch 42 and the comparison patch 43 are just touching can be performed very easily by visual inspection. The head mounting position adjustment pattern 40 is printed by supplying ink of the same color, for example, gray, to the reference nozzle row 15A and the comparison nozzle row 15B. For this reason, when there is a gap 44 between the reference patch 42 and the comparison patch 43, the gap 44 is recognized as a white stripe. Further, when the reference patch 42 and the comparison patch 43 are printed in an overlapping manner, the overlapping portion 45 is printed as a dark streak (black streak) with a darker color. Then, when the reference patch 42 and the comparison patch 43 are just touching each other, a continuous fill pattern having no white or black stripes is printed as in the unit patches 415A, 415B, and 415C in FIG. 5B. . Such presence / absence of white stripes and presence / absence of black stripes can be determined visually, and can be performed very easily and accurately. In addition, the print result is captured by a camera or the like and processed to measure and determine either the width of the reference patch 42 and the comparison patch 43 in the X direction, the width of the gap 44, or the width of the overlapping portion 45 (black stripe). You can also

  When the position of the unit patch 41 having no white or black stripe in the center (specific unit inspection pattern) is deviated from the center of the nine pairs to the upper end side of the row (head front end side), it is larger than the set interval. The reference patch 42 and the comparison patch 43 are printed at a narrow printing interval L. Therefore, in this case, it can be determined that the nozzle row interval D between the reference nozzle row 15A and the comparison nozzle row 15B is narrower than the reference interval D0. On the other hand, when the position of the unit patch 41 having neither white stripes nor black stripes is shifted from the center of the nine pairs toward the lower end side of the row (head rear end side), the printing interval L wider than the set interval. The reference patch 42 and the comparison patch 43 are printed. Therefore, in this case, it can be determined that the nozzle row interval D between the reference nozzle row 15A and the comparison nozzle row 15B is wider than the reference interval D0.

  Here, the amount of deviation between the nozzle row interval D and the reference interval D0 can be determined by the target value of the print interval L printed with the unit patch 41 having neither white nor black stripes. In the head attachment position adjustment pattern 40, the target value of the printing interval L of each unit patch corresponds to the printing position of each unit patch 41. Therefore, based on how much the printing position of the unit patch 41 without white stripes and black stripes deviates from the set printing position, the reference interval D0 between the reference nozzle row 15A and the nozzle row interval D of the comparison nozzle row 15B is determined. Can determine the difference.

  In addition, when the deviation | shift amount of the nozzle row space | interval D and the reference space | interval D0 is smaller than 1 dot, the case where the unit patch 41 in which the reference | standard patch 42 and the comparison patch 43 touch completely is not printed is also considered. In this case, the unit patch 41 having the narrowest white stripe width or the unit patch 41 having the narrowest black stripe width is detected, and the reference interval D0 and the actual nozzle row interval D are detected based on the positions of the patches. And the difference can be detected.

  In this embodiment, the nozzle row interval D between the reference nozzle row 15A and the comparison nozzle row 15B is detected at three positions of the front end, the center, and the rear end of the nozzle row, and the reference nozzle row 15A and the comparison nozzle row 15B are parallel. In this case, the nozzle row intervals at these three positions are equal. That is, in each unit patch group 40A, 40B, 40C, when the position of the unit patch 41 having no white stripe or black stripe in the center is the same position in the vertical direction, it is compared with the reference nozzle row 15A. It can be determined that the nozzle row 15B is parallel. For example, as shown in FIG. 5B, when the unit patches 415A, 415B, and 415C at the middle position (fifth) in the vertical direction are unit patches 41 without white and black lines, the reference It can be determined that the nozzle row 15A and the comparison nozzle row 15B are parallel.

  Next, the case where the comparison nozzle row 15B is inclined with respect to the reference nozzle row 15A will be described with reference to FIG. FIG. 6 shows a print example of the head attachment position adjustment pattern. FIG. 6A is an explanatory diagram of the reference head 13A and the inspection target head 13B used for the printing, and FIG. 6B is a printing result of the head attachment position adjustment pattern. In FIG. 6B, in the unit patch group 40A, the third unit patch 413A from the top of the column has a pattern with no white or black stripes. As described above, in the nine pairs of unit patches 41 constituting each unit patch group 40A, 40B, 40C, it is assumed that the printing interval L between the reference patch 42 and the comparison patch 43 is different by a unit amount corresponding to one dot. The nozzle row interval D between the reference nozzle row 15A and the comparison nozzle row 15B is narrower by 2 dots than the reference interval D0 in the head front end region S1. Next, in the unit patch group 40B, the fifth unit patch 416B from the top of the row has a pattern with no white or black stripes. In this case, since the unit patch 41 having no white or black stripes is printed at the set position, the nozzle row interval D between the reference nozzle row 15A and the comparison nozzle row 15B is the region S2 in the central portion of the head. In FIG. 5, the reference interval D0 coincides. In the unit patch group 40C, the seventh unit patch 419C from the upper end of the row has a pattern with no white or black stripes. Accordingly, the nozzle row interval D between the reference nozzle row 15A and the comparison nozzle row 15B is wider by 2 dots than the reference interval D in the head rear end region S3.

  As described above, according to FIG. 6B, the nozzle row interval D on the front end side of the head can be determined as the reference interval D0 + 2 dots based on the printing result of the unit patch group 40A. The nozzle row interval D on the rear end side of the head can be determined as the reference interval D0-2 dots based on the printing result of the unit patch group 40C. Accordingly, the difference Δd in the nozzle row interval D at both ends of the nozzle row can be determined to be 4 dots, and the relative inclination angle between the reference nozzle row 15A and the comparison nozzle row 15B is calculated based on this size and the arrangement length of the nozzle row. it can. Therefore, the tilt adjustment amount (rotation angle) of the second head 13B with respect to the first head 13A for making the reference nozzle row 15A and the comparison nozzle row 15B parallel can be determined.

  On the other hand, according to FIG. 6B, the nozzle row interval D in the central portion of the head can be determined to be equal to the reference interval D0 based on the printing result of the unit patch group 40B. Therefore, when the second head 13B is rotated by a predetermined angle with the center of the second head 13B as the rotation center, the reference nozzle row 15A and the comparison nozzle row 15B can be arranged relative to each other as designed only by this angle adjustment. can do. Therefore, in this case, it is not necessary to perform position adjustment by parallel movement of the second head 13B in the head arrangement direction (X direction) with respect to the first head 13A.

  However, in this case, the tilt adjustment of the second head 13B can also be performed with the nozzle row interval portion different from the reference interval D0, such as the front end or the rear end of the second head 13B, as the rotation center. In this case, the second head 13B is translated in the head arrangement direction by the difference between the nozzle row interval D at the center of rotation and the reference interval D0. Thereby, adjustment of the mounting position of the second head 13B with respect to the first head 13A can be executed so that the reference nozzle row 15A and the comparison nozzle row 15B are arranged at a predetermined interval and are parallel to each other.

  Further, when the nozzle row interval D in the center of the head is the reference interval D0 + n dots or the reference interval D0-n dots, the second head 13B is moved by −n dots or + n dots relative to the first head 13A. The position may be adjusted in parallel in the head array direction by moving in the head array direction.

  As described above, according to the present embodiment, the unit patch 41 printed as one continuous patch in which the reference patch 42 and the comparison patch 43 are not formed with white stripes or black stripes is used as the head attachment position adjustment pattern. The nozzle row interval D at each of the front end, center, and rear end positions of the head can be accurately determined by an extremely easy determination method of visually determining from 40 and confirming the position. Thereby, the relative inclination of the reference nozzle row 15A and the comparison nozzle row 15B and the nozzle row interval D can be accurately determined only by visual determination. Moreover, the relative inclination of the nozzle rows and the nozzle row spacing D at a plurality of positions can be determined by printing the head mounting position adjusting pattern 40 only once. Therefore, the attachment position adjustment amount of the inspection target head 13B with respect to the reference head 13A can be determined efficiently and easily, and the adjustment operation of the head attachment position can be performed very easily and accurately.

  In the above description, the ink jet printer has been described as an example of the liquid ejecting apparatus. However, other liquid ejecting apparatuses can be applied. For example, a solution or solvent other than ink may be ejected by a nozzle to color or paint something other than paper, or another liquid ejection device constituting a film, a wiring pattern, an insulating pattern, or the like.

(Modification example)
(1) In the above embodiment, printing is performed using the nozzles arranged at the three positions of the front end, the center, and the rear end of the head, and the nozzle row interval D at each position is determined. In other words, it is only necessary to determine the nozzle row interval D at any two positions apart from each other in the nozzle row. If the nozzle row interval D can be determined at at least two positions, the nozzle row interval D at the center of the head can be calculated by linear interpolation or the like. Accordingly, if the nozzle row interval D is determined at at least two positions, it is possible to adjust the relative inclination of the inspection target head 13B with respect to the reference head 13A and the position adjustment in the head arrangement direction. In this case, the head unit scanning position is set at two positions, the first position and the second position, and the unit test pattern 41 is printed at each position, and the head mounting position adjustment pattern consisting of two rows of unit patch groups. Can be printed.

(2) In the above embodiment, the reference nozzle row 15A and the comparison nozzle row 15B are nozzle rows provided in different heads. However, in the method of the present invention, the nozzle rows provided in the same head are relative to each other. It can also be used to determine the correct positional relationship. In this case, the arrangement of the nozzle rows cannot be adjusted by adjusting the mounting position of the head, but the color overlay accuracy can be improved by correcting the print data using data on the determined inclination and misalignment between the nozzle rows. The decrease can be suppressed.

(3) In the above embodiment, one set of the reference head 13A and the inspection target head 13B is selected, and the relative positional relationship between the set of heads is confirmed by printing the head mounting position adjustment pattern 40. However, a plurality of combinations of the reference head 13A and the inspection target head 13B may be set, and the head mounting position adjustment patterns 40 corresponding to each set may be arranged and printed on one sheet. For example, if the head 13 (1) is used as a reference head and the attachment position adjustment amount of the heads 13 (2) to 13 (n) relative to the head 13 (1) is grasped by one printing, the head attachment position as shown in FIG. The adjustment pattern 50 may be printed. The head attachment position adjustment pattern 50 is a pattern in which the head attachment position adjustment patterns 40 (1) to 40 (n-1) are arranged in a printable layout. In this way, it is possible to determine the adjustment amount of the mounting position between the plurality of sets of heads based on a single printing result.

DESCRIPTION OF SYMBOLS 1 ... Inkjet printer, 2 ... Printer case, 8 ... Ink cartridge mounting part, 9 ... Ink cartridge, 10 ... Printer mechanism part, 12 ... Platen, 13 ... Inkjet head, 13 (1) -13 (n) ... Head, 13A Reference head (first head), 13B ... Inspection head (second head), 14 ... Carriage, 14a ... Carriage guide shaft, 14b ... Carriage drive mechanism, 15 (1) to 15 (n) ... Nozzle array, 15A Reference nozzle row, 15B ... Comparison nozzle row, 17 ... Flexible ink tube, 18 ... Ink supply path, 30 ... Control unit, 31 ... Host device, 32 ... Head mounting position adjusting means, 40, 40 (1)- 40 (n-1): Head mounting position adjustment pattern, 40A, 40B, 40C: Unit patch group, 41: Unit patch (unit detection) Pattern), 42 ... reference patch, 43 ... comparison patch, 44 ... gap, 45 ... overlapping portion, 50 ... head mounting position adjustment pattern, 151A, 152A, 153A ... nozzle, 151B, 152B, 153B ... nozzle, 411A-419A ... unit patch, 412B to 419B ... unit patch, 411C to 419C ... unit patch, AP ... away position, HP ... home position, D ... nozzle row interval, D0 ... reference interval, L ... printing interval

Claims (7)

A nozzle row arrangement inspection method in a head unit including a plurality of heads having nozzle rows,
Select a reference nozzle row and a comparison nozzle row from nozzle rows with different heads,
In the reference nozzle row and the comparison nozzle row, set an arrangement position of at least a part of the nozzle arrangement direction,
Using the nozzles at the arrangement positions in the reference nozzle row and the comparison nozzle row, a reference pattern discharged by the nozzles of the reference nozzle row and a comparison pattern discharged by the nozzles of the comparison nozzle row at a predetermined discharge interval. A plurality of pairs of unit test patterns arranged side by side, with the target value of the discharge interval being different by a predetermined unit amount,
Based on a target value of the discharge interval in a specific unit test pattern in which the reference pattern and the comparison pattern have a specific discharge interval among the plurality of pairs of unit test patterns that have been discharged, A nozzle row arrangement inspection method, wherein a nozzle row interval, which is a relative distance between a reference nozzle row and the comparison nozzle row, is determined. A nozzle row arrangement inspection method in a head unit including a plurality of heads having nozzle rows,
Select a reference nozzle row and a comparison nozzle row from nozzle rows with different heads,
In the reference nozzle row and the comparison nozzle row, set at least a first position and a second position separated from each other in the nozzle arrangement direction,
Using the nozzles at the first position in the reference nozzle row and the comparison nozzle row, a reference pattern discharged by the nozzles in the reference nozzle row and a comparison pattern discharged by the nozzles in the comparison nozzle row are set to a predetermined discharge interval. A plurality of pairs of unit test patterns arranged side by side with a target value of the discharge interval being varied by a predetermined unit amount,
Based on a target value of the discharge interval in a specific unit inspection pattern in which the reference pattern and the comparison pattern have a specific discharge interval among the plurality of pairs of unit inspection patterns that have been discharged, the first position Determining a nozzle row interval which is a relative distance between the reference nozzle row and the comparison nozzle row;
Using the nozzles at the second position in the reference nozzle row and the comparison nozzle row, the plurality of pairs of unit test patterns are ejected, and the specific unit test pattern in the plurality of pairs of unit test patterns that have been ejected Based on the target value of the discharge interval in the discharge, determine the nozzle row interval in the second position,
A nozzle row arrangement inspection method, comprising: determining a relative inclination between the reference nozzle row and the comparison nozzle row based on a difference between the nozzle row intervals at the first position and the second position. In claim 1 or 2,
For each of the discharged unit test patterns, a unit test pattern in which neither a gap nor an overlap between the reference pattern and the comparison pattern is formed is the specific unit test pattern. Method. In claim 2,
The head unit is mounted on a carriage, and is scanned a plurality of times in a scanning range that passes through at least the first scanning position and the second scanning position,
As each scan is performed,
At the first scanning position, a pair of unit inspection patterns are ejected using the nozzles at the first position, and at the second scanning position, a pair of unit inspection patterns are ejected using the nozzles at the second position. ,
In each scan, the target value of the discharge interval for discharging the unit test pattern is varied by a predetermined unit amount, whereby the first position and the second position are completed along with the completion of the plurality of scans. A nozzle row arrangement inspection method comprising: completing ejection of the plurality of pairs of unit inspection patterns by each of the nozzles. A head mounting position adjusting method in a head unit having a plurality of heads,
The plurality of heads include at least a first head provided with a reference nozzle row and a second head provided with a comparison nozzle row,
5. The nozzle row arrangement inspection method according to claim 2, wherein the arrangement direction of the first head and the second head and an increase / decrease direction of the discharge interval are made to coincide with each other, thereby Determining the nozzle row spacing at the second position;
An attachment position adjustment method for a head, wherein an attachment position adjustment amount of the second head with respect to the first head is determined based on the determination result. In claim 5,
The first position is a position on one end side in the nozzle arrangement direction,
The second position is a position on the other end side in the nozzle arrangement direction,
Based on the difference between the nozzle row intervals at the first position and the second position, an inclination adjustment amount of the second head with respect to the first head is determined,
Using the nozzle at the third position located between the first position and the second position in each head, the plurality of sets of unit test patterns are ejected from the plurality of pairs of unit test patterns that have been ejected. Detecting the specific unit test pattern, and determining the nozzle row interval at the third position based on a target value of the discharge interval in discharging the specific unit test pattern;
A head mounting position adjusting method, wherein a parallel movement amount of the second head in the head array direction with respect to the first head is determined based on the determination result. In claim 6,
The third position is a central position in the nozzle arrangement direction,
Scanning the head unit a plurality of times in a scanning range passing through at least the first scanning position, the second scanning position, and the third scanning position;
As each scan is performed,
In the first scanning position, a pair of unit test patterns are ejected using only the nozzles on the one end side, and in the second scanning position, a pair of unit test patterns are ejected using only the central nozzle, Further, at the third scanning position, a pair of the unit test patterns are ejected using only the nozzle on the other end side,
In each scan, by changing the target value of the discharge interval for discharging the unit test pattern by a predetermined unit amount, the one end side, the center, the other, etc. A method for adjusting a mounting position of a head, comprising: completing ejection of the plurality of pairs of unit test patterns by each nozzle on an end side.