JP2013159040A - Inkjet printer and method of adjusting inkjet head position - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inkjet printer and a method of adjusting an inkjet head position which facilitate position adjustment of an inkjet head.SOLUTION: In a method of adjusting the position of an inkjet head 41, either of a plurality of reference pins of which sizes of position reference parts contacting with the inkjet head 41 is arranged detachably and selectively in three reference pin hole parts 47 arranged along an outer circumference of a head arranging region 45. Thereby, the reference pin having the position reference part of an optional size is arranged in the reference pin hole part without interposing a shim between a buried parallel pin and the inkjet head as in a conventional method. Thus, the position adjustment of the inkjet head 41 can be carried out easily. As a result, a burden on an operator can be reduced.

Description

  The present invention relates to an inkjet printing apparatus and an inkjet head position adjusting method for performing printing by ejecting ink droplets from an inkjet head onto a printing target while relatively moving the inkjet head and a printing target (for example, printing paper).

  Conventionally, in a printing unit of an inkjet printing apparatus, as shown in FIG. 12, a plurality of inkjet heads 241 (hereinafter referred to as “heads” as appropriate) are arranged on a head base 243 in a staggered arrangement. Each head 241 is arranged so as to overlap with the adjacent head 241 in the paper conveyance direction 201 which is the sub-scanning direction so that there is no gap. As a result, one long printing range is realized in the head alignment direction (main scanning direction) 202 orthogonal to the paper conveyance direction 201. The head 241 is provided with a plurality of nozzles (not shown) for ejecting ink droplets in the head arrangement direction 202 and a plurality of nozzle rows.

  Further, for example, when ejecting ink droplets of four colors of black (K), cyan (C), magenta (M), and yellow (Y), the printing unit is disposed so as to overlap with the adjacent head 241. A plurality of line heads 223 including a plurality of heads 241 are formed for each color in the paper transport direction 201.

  As described above, the printing unit includes a plurality of heads 241 in order to realize a printing range that is long in the main scanning direction. Therefore, it is necessary to adjust the position of the head 241 individually. As a conventional method of adjusting the position of the head 241, for example, a reference pin (projection) 262 serving as a positioning reference is provided on the head base 243, the head 241 is brought into contact with the reference pin 262, and the head is fixed with the head fixing screw 255. 241 is fixed to the head base 243. The reference pin 262 is configured by providing a hole in the outer periphery of the head arrangement region of the head base 243 and embedding a parallel pin in the hole.

  Further, Patent Document 1 or 2 proposes the following head position adjustment method. That is, Patent Document 1 discloses a support frame that supports a head unit (inkjet head) and a head unit having an arm portion. In the support frame, a unit arrangement tank partitioned by a side wall is formed for each head unit. On the other hand, an eccentric machine screw is provided on the arm portion of the head unit. The distance between the inner wall (positioning reference portion) and the head unit is adjusted by rotating the eccentric machine screw. Further, the position and inclination of the head unit are adjusted while grasping the position of the nozzle of the head unit with an optical microscope.

  Patent Document 2 discloses a head holder that holds an ink jet recording head (ink jet head), a pressing spring that presses the head holder to rotate, and an adjustment screw that stops the rotation of the head holder in accordance with the force received from the pressing spring. Are disclosed. The head holder is rotatably provided within the head surface where a plurality of discharge nozzles are arranged, and the tilt adjustment of the recording head (head holder) is performed by rotating the adjusting screw.

JP 2006-212791 A JP 2011-051213 A

  However, the method for adjusting the position of the head 241 of the conventional apparatus shown in FIG. 12 has the following problems. The reference pin (parallel pin) 262 is embedded and fixed in the head base 243. Then, the operator fixes the head 241 to the head base 243 while pressing the head 241 against the reference pin 262. However, due to the processing accuracy of the head 241, the processing accuracy of the reference pin position of the head base 243, the inclination of the embedded reference pin (parallel pin) 262, an error occurs in the position of the head 241 in contact with the reference pin 262. As a method for adjusting the position of the head 241, first, a thin metal tape called a shim (for example, 10 μm or 20 μm thick) is prepared. Then, in accordance with the position adjustment amount (positional deviation and inclination) of the head 241 obtained from the printed head position adjustment pattern, a shim is sandwiched between the reference pin (parallel pin) 262 and the head 241 to position the head 241. The fine adjustment is performed. Therefore, the burden imposed on the worker is large. In addition, the position of the head 241 varies due to the worker's pressing force against the reference pin 262 and the order in which it is applied.

  In other words, the accuracy of the head base 243 and the like and variations among workers occur, and it cannot be said that the position adjustment of the head 241 is easy. Therefore, for example, when a four-color line head 223 is employed in the printing unit, the head base 243 is provided with, for example, 80 heads 241 (each 20 colors × 4 colors), so that a burden imposed on the operator is increased. It becomes very big.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide an inkjet printing apparatus and an inkjet head position adjustment method in which the position adjustment of the inkjet head is easy.

In order to achieve such an object, the present invention has the following configuration.
That is, the inkjet head position adjusting method according to the present invention is the inkjet head position adjusting method in which the position of the inkjet head is adjusted with respect to a head fixing portion that fixes an inkjet head that ejects ink droplets onto a print target. A step of arranging the ink jet head in a head arrangement area provided in the section, and a size of a position reference part in contact with the ink jet head in three or more reference pin holes provided along the outer periphery of the head arrangement area And a step of selectively detachably disposing any of a plurality of reference pins having different values.

  According to the inkjet head position adjusting method according to the present invention, a plurality of reference pins having different sizes of the position reference portions contacting the inkjet head are provided in three or more reference pin hole portions provided along the outer periphery of the head arrangement region. Either one is selectively detachable. Therefore, as in the prior art, a reference pin having a position reference portion of any size can be disposed in the reference pin hole portion without interposing a shim between the embedded parallel pin and the inkjet head. Therefore, it is possible to easily adjust the position of the inkjet head. As a result, the burden on the worker can be reduced.

  Further, in the ink jet head position adjusting method according to the present invention, the pressing pin for pressing the ink jet head can be attached to and detached from the pressing pin hole portion provided individually facing the reference pin hole portion across the head arrangement region. Preferably, the method includes a step of arranging, and a step of pressing the inkjet head with the pressing pin after arranging the inkjet head, the reference pin, and the pressing pin.

  A pressing pin that presses the head is detachably disposed in a pressing pin hole portion that is individually provided facing the reference pin hole portion across the head arrangement region. And an inkjet head is pressed with the pressing pin arrange | positioned at the pressing pin hole part. Thereby, first, the dispersion | variation in the force which presses the inkjet head which had arisen between operators can be made uniform. Further, the pressing pin is detachable. Therefore, for example, when fixing the inkjet head again or when fixing another inkjet head, the same pressing pin can be used, and the pressing force of the inkjet head can be made uniform. Thereby, the reproducibility of an inkjet head position can be improved.

  Further, in the inkjet head position adjusting method according to the present invention, the step of pressing with the pressing pin includes pressing the inkjet head with two or more pressing pins arranged in a direction orthogonal to the printing target transport direction, and then printing target. It is preferable to press the inkjet head with one or more pressing pins arranged in the transport direction. That is, it is possible to easily adjust the inkjet head to a uniform inclination, in particular, by pressing the inkjet head with two or more pressing pins arranged in a direction orthogonal to the printing target transport direction. Thereby, the reproducibility of the inkjet head position can be further improved.

  In the inkjet head position adjusting method according to the present invention, the pressing pin includes a rotating shaft concentric with the pressing pin hole portion, a pressing portion provided eccentrically with respect to the rotating shaft, and an outer periphery of the pressing portion. It is preferable that a surface of the ink jet head that is in contact with the ink jet head has a smooth elastic body, and the ink jet head is pressed by the elastic body by rotating the rotating shaft. That is, by rotating the rotating shaft, the inkjet head is pressed with a uniform force by an elastic body having a repulsive force. Further, since the elastic body has a smooth surface in contact with the inkjet head, the elastic body can be slid with respect to the inkjet head. Therefore, it is possible to prevent the inkjet head from being displaced due to friction of the elastic body, and to easily adjust the inkjet head to a uniform position. Thereby, the reproducibility of the ink jet head can be further improved.

  In the inkjet head position adjusting method according to the present invention, it is preferable that the pressing portion has a flat portion at a position where the pressing force to the inkjet head is maximized. Thereby, when the rotating shaft is rotated and the elastic body provided on the outer periphery of the pressing portion is pressed, the position where the pressing force to the ink jet head becomes maximum can be easily understood. Therefore, the elastic body can be pressed with a constant force.

  In the ink jet head position adjusting method according to the present invention, the elastic body is preferably an O-ring. The O-ring has little friction with the inkjet head due to its circular cross section. The inkjet head can be slid against the inkjet head while being pressed. Moreover, it can be acquired at low cost.

  In the inkjet head position adjusting method according to the present invention, when the inkjet head fixed to the head fixing portion is displaced, a reference pin disposed in the reference pin hole according to the displacement. It is preferable to include a step of rearranging the reference pins on the reference pins having the position reference portions of other sizes. When the inkjet head is misaligned, it is easy to adjust the misalignment by rearranging the reference pins on the reference pins having position reference portions of other sizes.

  Further, in the inkjet head position adjusting method according to the present invention, when the inkjet head fixed to the head fixing portion is inclined, two or more in a direction orthogonal to the printing target conveyance direction is determined according to the inclination. Preferably, the method includes a step of rearranging the reference pins on the reference pins having the position reference portions of different sizes. When the inkjet head is inclined, the inclination can be easily adjusted by rearranging the reference pins on the reference pins having the position reference portions of different sizes.

  Moreover, in the inkjet head position adjusting method according to the present invention, an example of the head fixing portion is fixing a plurality of inkjet heads. Thereby, even when fixing a some inkjet head to a fixed head, position adjustment of a some inkjet head can be performed easily.

  In the ink jet head position adjusting method according to the present invention, an example of the ink jet head is an ink jet head module in which a plurality of the ink jet heads that eject ink droplets onto a printing target are arranged at preset positions. Thereby, even when fixing the inkjet head module in which the several inkjet head is arrange | positioned to a fixed head, the position adjustment of an inkjet head module can be performed easily.

  Further, in the ink jet printing apparatus according to the present invention, in the ink jet printing apparatus provided with a head fixing portion for fixing an ink jet head for ejecting ink droplets to a printing target, the head fixing portion is a head arrangement in which the ink jet head is arranged. Three or more references provided along the outer periphery of the head arrangement area, wherein one of a plurality of reference pins having different sizes of the area and the position reference portion in contact with the inkjet head is selectively detachably arranged And a pin hole portion.

  According to the ink jet printing apparatus according to the present invention, the head fixing portion has an outer periphery of the head arrangement region in which any of a plurality of reference pins having different sizes of the position reference portion in contact with the ink jet head is selectively detachable. And three or more reference pin holes provided along the line. Therefore, as in the prior art, a reference pin having a position reference portion of any size can be disposed in the reference pin hole portion without interposing a shim between the embedded parallel pin and the inkjet head. Accordingly, the position adjustment of the ink jet head can be easily performed. As a result, the burden on the worker can be reduced.

  Further, in the ink jet printing apparatus according to the present invention, the head fixing portion is provided individually so as to face the reference pin hole portion with the head arrangement region interposed therebetween, wherein a pressing pin for pressing the ink jet head is detachably arranged. It is preferable to include a pressed pin hole portion.

  The head fixing portion includes a pressing pin hole portion provided separately from the reference pin hole portion across the head arrangement region. A pressing pin that presses the ink jet head is detachably disposed in the pressing pin hole. And an inkjet head is pressed with the pressing pin arrange | positioned at the pressing pin hole part. Thereby, first, the dispersion | variation in the force which presses the inkjet head which had arisen between operators can be made uniform. Further, the pressing pin is detachable. Therefore, for example, when fixing the inkjet head again or when fixing another inkjet head, the same pressing pin can be used, and the pressing force of the inkjet head can be made uniform. Thereby, the reproducibility of an inkjet head position can be improved.

  Moreover, in the ink jet printing apparatus according to the present invention, an example of the head fixing portion is fixing a plurality of ink jet heads. Thereby, even when fixing a some inkjet head to a fixed head, position adjustment of a some inkjet head can be performed easily.

  In the ink jet printing apparatus according to the present invention, an example of the ink jet head is an ink jet head module in which a plurality of the ink jet heads that eject ink droplets onto a print target are arranged at preset positions. Thereby, even when fixing the inkjet head module in which the several inkjet head is arrange | positioned to a fixed head, the position adjustment of an inkjet head module can be performed easily.

  According to the ink jet head position adjusting method of the first aspect of the present invention, a plurality of reference pin hole portions provided along the outer periphery of the head arrangement region have a plurality of different position reference portions contacting the ink jet head. One of the reference pins is selectively detachably disposed. Therefore, as in the prior art, a reference pin having a position reference portion of any size can be disposed in the reference pin hole portion without interposing a shim between the embedded parallel pin and the inkjet head. Therefore, it is possible to easily adjust the position of the inkjet head. As a result, the burden on the worker can be reduced.

  According to the ink jet printing apparatus of the second aspect of the present invention, the head fixing part is a head in which any one of a plurality of reference pins having different sizes of the position reference part in contact with the ink jet head is selectively detachable. And three or more reference pin holes provided along the outer periphery of the arrangement region. Therefore, as in the prior art, a reference pin having a position reference portion of any size can be disposed in the reference pin hole portion without interposing a shim between the embedded parallel pin and the inkjet head. Accordingly, the position adjustment of the ink jet head can be easily performed. As a result, the burden on the worker can be reduced.

It is a schematic block diagram of the inkjet printing apparatus which concerns on an Example. It is a top view with which it uses for description of an inkjet head and a head base. (A) is a plan view showing an example of one inkjet head fixed to the head base, and (b) is a cross-sectional view showing an example of one inkjet head fixed to the head base. It is a side view which shows an example of a reference | standard pin. (A) is a side view which has a partial cross section which shows an example of a pressing pin, (b) is a bottom view of the pressing pin seen from the head base side of (a). (A) is a side view which has a partial cross section which shows an example of a pressing pin, (b) is a bottom view of the pressing pin seen from the head base side of (a). It is a figure which shows the flowchart of the head position adjustment method which concerns on an Example. (A)-(d) is a figure where it uses for description of the head position adjustment method. (A) is a figure used for description of an example without misalignment and inclination in determination of misalignment and inclination, and (b) is used for description of an example of position misalignment and inclination in determination of misalignment and inclination. FIG. It is a bottom view which shows an example of the pressing pin which concerns on a modification. It is a top view which shows the inkjet head module which concerns on a modification. It is a top view with which it uses for description of the conventional inkjet and a head base.

  Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic configuration diagram of an ink jet printing apparatus according to an embodiment, and FIG. 2 is a plan view for explaining an ink jet head and a head base. FIG. 3A is a plan view showing an example of one inkjet head fixed to the head base, and FIG. 3B is a cross section showing an example of one inkjet head fixed to the head base. FIG.

  Please refer to FIG. The ink jet printing apparatus 1 includes an ink jet printing unit 2 that performs printing on a continuous paper WP, a paper feeding unit 3 that supplies the continuous paper WP to the ink jet printing unit 2, and a paper discharge unit that winds the continuous paper WP after printing into a roll shape. And a paper section 4. The continuous paper WP corresponds to the printing object of the present invention.

  The paper feed unit 3 holds the roll-shaped continuous paper WP so as to be rotatable about a horizontal axis, and unwinds and supplies the continuous paper WP to the inkjet printing unit 2. The paper discharge unit 4 winds the continuous paper WP printed by the inkjet printing unit 2 around the horizontal axis. When the supply side of the continuous paper WP is the upstream side and the discharge side of the continuous paper WP is the downstream side, the paper feed unit 3 is disposed upstream of the inkjet printing unit 2, and the paper discharge unit 4 is the inkjet printing unit 2. It is arranged downstream.

  The ink jet printing unit 2 includes a driving roller 7 for taking in the continuous paper WP from the paper feeding unit 3 on the upstream side. The continuous paper WP unwound from the paper feed unit 3 by the driving roller 7 is conveyed toward the downstream paper discharge unit 4 along a rotatable conveyance roller 9 having no driving mechanism. A driving roller 11 is disposed between an inspection unit 21 and a paper discharge unit 4 which will be described later. The drive roller 11 feeds the continuous paper WP that has passed through an inspection unit 21 described later toward the paper discharge unit 4.

  The inkjet printing unit 2 includes an edge position control unit 13, a driving roller 15, a printing unit 17, a drying unit 19, and an inspection unit 21 between the driving roller 7 and the driving roller 11 in that order from the upstream side. It is equipped with. The edge position control unit 13 automatically adjusts when the continuous paper WP meanders so that the continuous paper WP flows to a correct position. The drive roller 15 rotates at a constant speed and becomes a reference for the rotation speed of the other drive rollers 7 and 11 and a heat roller 27 described later.

  The driving rollers 7, 11, 15 are individually provided with nip rollers 22 so as to be rotatable. The nip roller 22 presses the driving rollers 7, 11, and 15 from the opposite side with the continuous paper WP interposed therebetween, thereby giving a conveying force of the continuous paper WP. The pressing force is given by, for example, an air cylinder. The nip roller 22 is made of an elastic body such as rubber.

  The printing unit 17 includes a line head 23 that ejects ink droplets in the width direction of the continuous paper WP. The line head 23 does not move in the main scanning direction orthogonal to the paper transport direction 201, and performs printing on the continuous paper WP while feeding the continuous paper WP while the position is fixed. In the printing unit 17, a plurality of line heads 23 are generally arranged along the paper conveyance direction 201 of the continuous paper WP. An ink supply unit 25 is connected to the printing unit 17 and supplies ink droplets to the printing unit 17 as necessary. The paper transport direction 201 corresponds to the print target transport direction of the present invention.

  The drying unit 19 dries the portion printed by the printing unit 17. The drying unit 19 includes a heat roller 27 with a heater (not shown) built therein. The heat roller 27 is driven to rotate similarly to the drive rollers 7, 11, and 15. The inspecting unit 21 inspects the printed portion for dirt or missing. The inspected continuous paper WP is wound around the paper discharge unit 4 in a roll shape.

  The inkjet printing apparatus 1 includes a main control unit 29 and an operation unit 31. The main control unit 29 comprehensively controls each component of the inkjet printing apparatus 1 and includes a central processing unit (CPU) and the like. The operation unit 31 operates the ink jet printing apparatus 1 and includes, for example, a touch panel and various switches. The operation unit 31 may be configured by a personal computer and input an operation using a mouse, a keyboard, or the like. The driving rollers 7, 11, 15 and the heat roller 27 are rotationally driven by a driving mechanism such as a motor or a gear (not shown).

  Next, the printing unit 17 will be described in detail. Reference is made to FIG. 2 or FIG. In the line head 23, as described above, a plurality of inkjet heads (heads) 41 are arranged (fixed) on the head base 43 in a staggered arrangement. The plurality of heads 41 are arranged so that the print range overlaps with the adjacent head 41, so that the width of the continuous paper WP can be reduced even if the print range of the head alignment direction (main scanning direction) 202 of one head 41 is short. A long printing range including For example, when performing four-color printing (ink droplet ejection) of black (K), cyan (C), magenta (M), and yellow (Y), the four line heads 23 are moved in the paper conveyance direction 201. It is provided along. Note that the number of line heads 23 is not limited to four, and the line heads 23 include at least one line head 23. The head base 43 corresponds to the head fixing portion of the present invention.

  The head base 43 is provided with a head arrangement region 45, a reference pin hole 47, and a pressing pin hole 49. The reference pin hole 47 and the pressing pin hole 49 are used to adjust the position of the head 41. A reference pin 61 (described later) is detachably disposed in the reference pin hole portion 47, and pressing pins 63 and 64 (described later) are detachably disposed in the pressing pin hole portion 49.

  Three reference pin hole portions 47 are provided in the head base 43 along the outer periphery of the head arrangement region 45. The reference pin hole portion 47 includes two reference pin hole portions 47 a provided along the head alignment direction 202 orthogonal to the paper conveyance direction 201 in the outer periphery of the head arrangement region 45, and the outer periphery of the head arrangement region 45. Of these, it is composed of one reference pin hole portion 47 b provided along the paper conveyance direction 201. The reference pin holes 47a and 47b are denoted by reference numeral 47 unless otherwise distinguished.

  The pressing pin hole portion 49 is individually provided to face the reference pin hole portion 47 with the head arrangement region 45 interposed therebetween. That is, three pressing pin holes 49 are provided in the head base 43. The pressing pin hole portion 49 includes a pressing pin hole portion 49a provided individually facing the reference pin hole portion 47a and a pressing pin hole portion 49b provided separately facing the reference pin hole portion 47b. Has been. In other words, two pressing pin holes 49a are provided in the head alignment direction 202 at positions facing the two reference pin holes 47a. On the other hand, one pressing pin hole 49b is provided in the paper conveyance direction 201 at a position facing one reference pin hole 47b. The pressing pin holes 49a and 49b are denoted by reference numeral 49 unless otherwise distinguished.

  The reference pin hole 47 and the pressing pin hole 49 may be holes that do not penetrate or holes that penetrate (holes).

  The head arrangement area 45 is an area where the head 41 is arranged. As shown in FIG. 3B, the head placement region 45 is provided with an opening 45 a at a position where the head 41 of the head base 43 is placed. The head 41 is fitted into the opening 45a. In the head 41, a plurality of nozzles 51 for ejecting ink droplets are arranged in the head arrangement direction (main scanning direction) 202, and the plurality of nozzles 51 arranged in a row are arranged in a plurality of rows such as 4 rows or 8 rows, for example. Is done. In addition, the nozzle 51 of Fig.3 (a) shows the case of 2 rows.

  The head 41 includes processing surfaces 41 a and 41 b for adjusting the position of the head 41 at a portion of the side surface thereof that contacts a position reference portion 69 of a reference pin 61 described later. The processed surface 41a is processed, for example, so as to be parallel to a line 53a connecting the centers of the plurality of nozzles 51 arranged in a line and at a preset distance from the line 53a. On the other hand, the processed surface 41b is processed, for example, so as to be parallel to the line 53b orthogonal to the line 53a and at a preset distance from the center of the reference nozzle 51.

  The head 41 is fixed to the head base 43 with a head fixing screw 55. Further, in FIG. 3B, the direction of ejecting ink droplets from the nozzle 51 is indicated by reference numeral 57.

[Reference pin and pressing pin]
Next, the reference pin 61 and the pressing pins 63 and 64, which are inkjet position adjustment jigs used for adjusting the position of the inkjet head 41, will be described. FIG. 4 is a side view showing an example of the reference pin. FIG. 5A is a side view having a partial cross section showing an example of the pressing pin, and FIG. 5B is a bottom view of the pressing pin as viewed from the head base side in FIG. 5A. FIG. 6A is a side view having a partial cross section showing an example of the pressing pin, and FIG. 6B is a bottom view of the pressing pin as viewed from the head base side in FIG. 6A.

  Please refer to FIG. The reference pin 61 is detachably disposed in the reference pin hole 47. The reference pin 61 is used for positioning the head 41. The reference pin 61 includes a knob portion 65, a shaft portion 67, and a position reference portion 69 that contacts the head 41. The position reference unit 69 is configured in a disc shape or a column shape. The reference pin 61 can finely adjust the position of the head 41 by the size (diameter) 71 of the position reference portion 69. That is, a plurality of reference pins 61 having different sizes (diameters) 71 of the position reference portion 69 are prepared in advance. For example, the reference pin hole 47 has a diameter 73 of 3.000 mm. On the other hand, for the reference pin 61, for example, a pin whose diameter 71 of the position reference portion 69 is 5.000 mm is prepared, and the diameter 71 of the position reference portion 69 for adjustment is 5.020 mm or 5.040 mm. 4.980 mm and 4.960 mm are prepared. One of the plurality of reference pins 61 is selectively arranged. The shaft portion 67 and the position reference portion 69 are made of metal such as stainless steel or titanium.

  Reference is made to FIG. 5A and FIG. Of the pressing pins 63 and 64, the pressing pin 63 will be described first. The pressing pin 63 is detachably disposed in the pressing pin hole 49. The pressing pin 63 presses the head 41 against the reference pin 61 by pressing the head 41. The pressing pin 63 is provided on the outer periphery of the knob portion 75, the rotating shaft portion 77 concentric with the pressing pin hole portion 49, the pressing portion 79 provided eccentric to the rotating shaft portion 77, and the pressing portion 79. And an elastic body 81. The rotating shaft portion 77 corresponds to the rotating shaft of the present invention.

  The pressing portion 79 is formed in, for example, a disk shape or a column shape, but may be a plate shape or a column shape having a closed curve in consideration of a rotation angle and an eccentric amount such as an ellipse. Further, as shown in FIG. 5A, a groove 79 a for receiving the elastic body 81 is formed on the side surface of the pressing portion 79. In addition, the rotating shaft part 77 and the press part 79 are comprised, for example with metals, such as stainless steel and titanium.

  The elastic body 81 is configured with a smooth surface in contact with the head 41. The elastic body 81 is configured by at least one of a material having a small friction coefficient and a material having a small contact area, for example. The elastic body 81 is an annular body having an elliptical or circular cross section, and is configured by, for example, an O-ring. The O-ring is made of rubber (for example, fluorine rubber or silicone rubber). The O-ring has little friction with the head 41 due to its circular cross section. The head 41 can be slid with respect to the head 41 while being pressed. Moreover, it can be acquired at low cost.

  In order to increase the amount of deformation, the O-ring may have a hollow circular cross section. The cross section is not limited to a circle but may be, for example, a semicircle. In this case, the curved surface is on the outside. In addition, the elastic body 81 may be provided only in a position where the eccentric amount is not limited to the annular shape but is in contact with the head 41. The elastic body 81 may be a synthetic resin or a metal. That is, the elastic body 81 only needs to have a spring-type repulsive force and a function of sliding with respect to the head 41.

  Reference is made to FIG. 6A and FIG. The pressing pin 64 is used when the distance between the pressing pin hole 49 and the head 41 is long. The pressing pin 64 includes a knob portion 75, a rotating shaft portion 77 concentric with the pressing pin hole portion 49, a pressing portion 85 that is separated from the rotating shaft portion 77 and provided eccentrically, and the rotating shaft portion 77 and the pressing pin. A connecting member 87 for connecting the portion 79 and an elastic body 81 provided on the outer periphery of the pressing portion 79 are provided. As shown in FIG. 6B, the pressing portion 85 has a groove 85a for receiving the elastic body 81, and is configured to have a flat portion 85b at a position where the pressing force is maximized. The pressing portion 85 is configured, for example, in a square plate shape or a prism shape. In addition, the description which overlaps with the pressing pin 63 is abbreviate | omitted.

  Next, the inkjet head position adjusting method will be described with reference to the flowchart of FIG. 7 and FIG. FIG. 8A to FIG. 8D are diagrams for explaining the head position adjusting method.

[Step S01] Head Arrangement Referring to FIG. FIG. 8A is a diagram illustrating a state in which the head 41 is not disposed on the head base 43. The head 41 is arranged in a head arrangement area 45 provided in the head base 43 (FIG. 8B). The head 41 is temporarily tightened by inserting the head fixing screw 55 into a head fixing screw hole 55a provided in the head 41 and the head base 43, and lightly tightening. The temporary tightening state is a state in which the tightening is loose and the position of the head 41 can be finely adjusted in the head placement region 45.

[Step S02] Arrangement of Reference Pins One of a plurality of reference pins 61 having different sizes of the position reference part 69 in contact with the head 41 is inserted into the three reference pin hole parts 47 provided along the outer periphery of the head arrangement area 45. Selectively detachable. In the case of FIG. 8A, the reference pin hole 47 includes two reference pin holes 47 a provided along the head alignment direction 202 and one reference pin hole provided along the paper conveyance direction 201. 47b. The reference pins 61 are individually inserted and arranged in two reference pin hole portions 47a provided in the head alignment direction 202 and one reference pin hole portion 47b provided in the paper conveyance direction 201 (FIG. 8 ( b)).

[Step S03] Arrangement of the Pressing Pins The pressing pins 63 and 64 for pressing the head 41 are detachably arranged in the pressing pin hole portions 49 provided individually facing the reference pin hole portion 47 with the head arrangement area 45 interposed therebetween. To do. In the case of FIG. 8 (a), the pressing pin hole portion 49 is provided separately from the pressing pin hole portion 49a provided to face the reference pin hole portion 47a and to the reference pin hole portion 47b. It is comprised by the pressing pin hole part 49b. The pressing pin 64 is disposed by being inserted into the two pressing pin holes 49a, and the pressing pin 63 is disposed by being inserted into the one pressing pin hole 49b (FIG. 8B).

[Step S04] Pressing with a pressing pin arranged in the head alignment direction Referring to FIG. After the head 41, the reference pin 61 and the pressing pins 63 and 64 are arranged, the head 41 is pressed by the pressing pins 63 and 64. First, the head 41 is pressed by the two pressing pins 64 arranged in the head alignment direction 202. That is, the head 41 is pressed by the elastic body 81 by rotating the rotating shaft portion 77 of the pressing pin 64. The elastic body 81 can be slid with respect to the head 41 while pressing the head 41 with the elastic body 81 with a uniform force. By sliding the elastic body 81, the positional deviation of the head 41 can be suppressed. In this step, in particular, the gap generated between the head 41 indicated by reference numeral 205 in FIG. 8C and the reference pin 61 can be suppressed, and the head 41 can be easily adjusted to a uniform inclination.

[Step S05] Pressing with the pressing pins arranged in the paper conveying direction After pressing the head 41 with the two pressing pins 64 arranged in the head alignment direction 202 in step S04, one pressing arranged in the paper conveying direction 201 is performed. The head 41 is pressed with the pin 63. That is, the head 41 is pressed by the elastic body 81 by rotating the rotary shaft portion 77 of the pressing pin 63. Accordingly, the elastic body 81 can be slid with respect to the head 41 while pressing the head 41 with the elastic body 81 with a uniform force. By sliding the elastic body 81, the positional deviation of the head 41 can be suppressed. By combining step 04 and step 05, the head 41 can be easily adjusted to a uniform position. Thereby, the reproducibility of the position of the head 41 can be improved.

  Although the rotation direction of the pressing pins 63 and 64 is not particularly limited, the rotation direction for pressing may be determined. For example, the pressing pin 64 may be rotated clockwise, and the pressing pin 63 may be rotated counterclockwise. That is, the pressing pin 64 is rotated in the direction in which the head 41 does not move toward the pressing pin 63 and the pressing pin 63 is moved toward the pressing pin 64. Reproducibility is improved by performing a certain procedure.

[Step S06] Fixing the Head The head 41 is fixed to the head base 43 by the head fixing screw 55. That is, the head 41 is changed from the temporarily fixed state to the final fixed state in which the head 41 is securely fixed to the head base 43.

[Step S07] Removal of Reference Pin and Pressing Pin After fixing the head 41, the reference pin 61 and the pressing pins 63 and 64 used for fixing and adjusting the position of the head 41 are respectively inserted from the reference pin hole 47 or the pressing pin hole 49. Remove (FIG. 8D).

[Step S08] Printing Head Position Adjustment Pattern For example, after 20 heads 41 are fixed to the head base 43, a head adjustment position pattern is printed.

[Step S09] Determination of displacement and inclination (position adjustment unnecessary?)
A positional deviation amount and an inclination amount, that is, a position adjustment amount of the head 41 is calculated from the printed head position adjustment pattern. In this process, the following items are confirmed. Reference is made to FIG. 9A and FIG. FIG. 9A is a diagram for explaining an example of no positional deviation and no inclination. In the case where it is determined that the position adjustment is not necessary, first, the line 91 composed of dots printed in the head alignment direction 202 is straight and there is no dot density. The line 91 is orthogonal to the line 92 with reference to the line 92 formed of the leftmost dot in the paper conveyance direction 201.

  FIG. 9B is a diagram for explaining an example of misalignment and inclination. It is assumed that there is a virtual line 91a with reference to the line 91 in FIG. The print pattern 93 is not orthogonal to the line 92 and is inclined. The printing patterns 94 and 95 are similarly inclined. The print pattern 96 is displaced in the paper conveyance direction 201 with respect to the line 91a. Similarly, the print pattern 94 is misaligned in the paper conveyance direction 201. Further, a positional shift (reference numeral 98) due to dot density occurs in the head arrangement direction 202 between the print patterns 96 and 97.

  When it is determined that the position adjustment of the head 41 is not necessary (for example, when the head position deviation and the inclination are equal to or less than preset threshold values), the position adjustment of the head 41 is ended (END). When it is determined that the position adjustment of the head 41 is necessary, the process proceeds to step S10.

[Step S10] Release of Head Fixation If it is determined in step S09 that the position of the head 41 needs to be adjusted, the fixation of the head 41 fixed to the head base 41 is released. That is, the head 41 is changed from the permanently fixed state to the temporarily fixed state.

[Step S11] Rearrangement of Reference Pin When the head 41 fixed to the head base 43 is displaced, the reference pin 61 disposed in the reference pin hole 47 is moved to another diameter 71 according to the displacement. The reference pin 61 having the position reference portion 69 is rearranged. When the head 41 fixed to the head base 43 is inclined, the two reference pins 61 in the head alignment direction 202 are changed to reference pins 61 having position reference portions 69 having different diameters 71 according to the inclination. Rearrange.

  In FIG. 8B, for example, when the head 41 is fixed, the sizes (diameters) 71 of the two reference pins 61 arranged in the head alignment direction 202 are both 5.000 mm. In order to move the head 41 upward, the diameter 71 of the two reference pins 61 moves 10 μm upward when the diameter 71 is 5.020 mm, and 20 μm moves upward when the diameter 71 is 5.040 mm. Further, when it is desired to move the head 41 downward, when the diameter 71 of the two reference pins 61 is 4.980 mm, the head 41 moves 10 μm downward, and when the diameter 71 is 4.960 mm, the head 41 moves 20 μm downward. Furthermore, when the inclination of the head 41 is desired to be adjusted, the two reference pins 61 are replaced with reference pins 61 each having a position reference portion 69 having a different diameter 71. This makes it easy to adjust the positional deviation and inclination of the head 41.

  After the reference pin 61 is rearranged, the process returns to step S03 and the pressing pins 63 and 64 are arranged.

  According to the inkjet printing apparatus 1 according to the present embodiment, the head base 43 includes three reference pin hole portions 47 provided along the outer periphery of the head arrangement region 45. In the three reference pin holes 47, any one of a plurality of reference pins 61 having different diameters 71 of the position reference part 69 in contact with the head 41 is detachably disposed. Therefore, the reference pin 61 having the position reference portion 69 having an arbitrary diameter 71 can be disposed in the reference pin hole portion 47 without sandwiching a shim between the embedded parallel pin and the head as in the conventional case. . Therefore, the position adjustment of the head 41 can be easily performed. As a result, the burden on the worker can be reduced.

  The head base 43 also includes three pressing pin hole portions 49 that are individually provided to face the reference pin hole portion 47 with the head arrangement region 45 interposed therebetween. In the pressing pin hole portion 49, pressing pins 63 and 64 for pressing the head 41 are detachably arranged. By pressing the head 41 with the pressing pins 63 and 64 disposed in the pressing pin hole portion 49, the force pressing the head 41 generated between workers can be made uniform. Further, since the pressing pins 63 and 64 are detachable, for example, when the head 41 is fixed again or when the other head 41 is fixed, the same pressing pins 63 and 64 are used, so the head 41 is pressed. The force can be made uniform. Since the force for pressing the head 41 can be made uniform, the reproducibility of the position of the head 41 can be improved.

  In addition, after pressing the head 41 with the two pressing pins 64 arranged in the head alignment direction 202, the head 41 is pressed with one pressing pin 63 arranged in the paper transport direction 201. That is, by first pressing the head 41 with the two pressing pins 64 arranged in the head alignment direction 202, the head 41 can be particularly easily adjusted to a uniform inclination. Thereby, the reproducibility of the position of the head 41 can be further improved.

  The pressing pins 63 and 64 are provided on the outer periphery of the pressing portion 79, a rotating shaft portion 77 concentric with the pressing pin hole portion 49, a pressing portion 79 provided eccentric to the rotating shaft portion 77, and An elastic body 81 having a smooth surface in contact with the head 41 is provided, and the head 41 is pressed with a uniform force by the elastic body 81 by rotating the rotating shaft portion 77. That is, the head 41 is pressed by the elastic body 81 having a repulsive force by rotating the rotating shaft portion 77. Further, since the elastic body 81 has a smooth surface in contact with the head 41, the elastic body 81 can be slid with respect to the head 41. Therefore, the head 41 can be prevented from being displaced due to the friction of the elastic body 81, and the head 41 can be easily adjusted to a uniform position. Thereby, the reproducibility of the position of the head 41 can be further improved.

  In addition, like patent document 2, providing an adjustment screw (for example, micrometer) is also considered. However, there is a space problem such as a place where a micrometer cannot be arranged. On the other hand, this embodiment can easily adjust the position of the head 41.

  The present invention is not limited to the above embodiment, and can be modified as follows.

  (1) In the embodiment described above, the pressing portion 63 of the pressing pin 63 shown in FIGS. 5 (a) and 5 (b) has a disk-like or cylindrical shape. However, as shown in FIG. 10, the pressing portion 79 may have a flat portion 79 b at a position where the pressing force against the head 41 is maximized. In other words, if the position where the pressing force is maximum remains a curved surface, the position may pass. Therefore, the flat surface portion 79b is provided at a position where the pressing force of the curved surface portion of the columnar or columnar pressing portion 79 to the head 41 is maximum, that is, a position where the amount of eccentricity is maximum. Thereby, when the rotating shaft part 77 is rotated and the elastic body 81 provided on the outer periphery of the pressing part 79 is pressed, the position where the pressing force to the head 41 becomes maximum can be easily understood. Therefore, the elastic body 81 can be pressed with a constant force.

  (2) In the embodiment and the modification example (1) described above, the plurality of heads 41 are fixed to the head base 43. However, as shown in FIG. 11, the head 41 is an inkjet head module (hereinafter referred to as “module”) 101 in which a head 41 for ejecting ink droplets onto a continuous paper WP is disposed at a preset position. Also good. Thereby, even when the module 101 on which the plurality of heads 41 are arranged is fixed to the head base 43, the position of the module 101 can be easily adjusted. Further, the module 101 includes processed surfaces 101a and 101b. The processed surfaces 101a and 101b are processed in the same manner as the processed surfaces 41a and 41b.

  (3) In the embodiment and the modification example (1) described above, the head base 43 fixes the plurality of heads 41. However, the head base 43 may be configured to fix the single head 41. For example, the present invention can be applied when the line head 23 is constituted by a single head 41. Alternatively, the single head 41 may be fixed to the head base 43 and printed while reciprocating in the main scanning direction which is the head alignment direction 202. Thereby, even when fixing the single head 41 to the head base 43, the position adjustment of the single head 41 can be performed easily. The inkjet head of the present invention includes a single inkjet head 41, a plurality of inkjet heads 41, and a module 101.

  (4) In the above-described embodiment and each modification, the head 41, the reference pin 61, and the pressing pins 63 and 64 are arranged in this order in the flowchart of FIG. However, the head 41, the reference pin 61, and the pressing pins 63 and 64 may be arranged in any order.

  (5) In the above-described embodiments and modifications, the reference pin hole 47 and the pressing pin hole 49 are not limited to three as shown in FIG. 3A, for example. That is, it may be three or more. For example, two reference pin holes 47b and pressing pin holes 49b in the paper conveyance direction may be provided.

  (6) In the above-described embodiments and modifications, the pressing pin 64 is disposed in the pressing pin hole 49a, and the pressing pin 63 is disposed in the pressing pin hole 49b. However, if necessary, the pressing pin 64 may be arranged in the pressing pin hole portion 49b, and the pressing pin 63 may be arranged in the pressing pin hole portion 49a.

  (7) In the above-described embodiments and modifications, for example, in FIG. 8B, the two reference pins 61 and the pressing pins 64 arranged in the head alignment direction are used without being distinguished from each other. However, the positions of the two reference pins 61 and the pressing pins 64 may be determined for the right side and the left side, respectively.

  (8) In the above-described embodiments and modifications, the ink jet printing apparatus 1 supplies the continuous paper WP to the ink jet printing unit 2. However, separated paper may be supplied.

DESCRIPTION OF SYMBOLS 1 ... Inkjet printing apparatus 17 ... Printing unit 23 ... Line head 41 ... Inkjet head (head)
43 ... Head base 45 ... Head arrangement area 47 (47a, 47b) ... Reference pin hole 49 (49a, 49b) ... Pressing pin hole 61 ... Reference pin 63, 64 ... Pressing pin 69 ... Position reference part 71 ... Size ( diameter)
77 ... Rotating shaft portion 79, 85 ... Pressing portion 79b, 85b ... Planar portion 81 ... Elastic body

Claims (14)

In an inkjet head position adjustment method for adjusting the position of the inkjet head with respect to a head fixing portion that fixes an inkjet head that discharges ink droplets to a print target,
Placing the inkjet head in a head placement area provided in the head fixing portion;
Any one of a plurality of reference pins having different sizes of the position reference portion contacting the inkjet head is detachably arranged in three or more reference pin hole portions provided along the outer periphery of the head arrangement region. Process,
An ink jet head position adjustment method comprising: The inkjet head position adjusting method according to claim 1,
A step of detachably arranging a pressing pin that presses the inkjet head into a pressing pin hole portion provided separately from the reference pin hole portion across the head arrangement region;
After placing the inkjet head, the reference pin and the pressing pin, pressing the inkjet head with the pressing pin;
An ink jet head position adjustment method comprising: The inkjet head position adjusting method according to claim 2,
The step of pressing with the pressing pin is performed by pressing the inkjet head with two or more pressing pins arranged in a direction orthogonal to the printing target conveyance direction, and then using one or more pressing pins arranged in the printing target conveyance direction. An ink jet head position adjusting method comprising pressing the ink jet head. In the inkjet head position adjustment method according to claim 2 or 3,
The pressing pin has a rotating shaft concentric with the pressing pin hole portion, a pressing portion provided eccentric to the rotating shaft, and a surface in contact with the inkjet head provided on an outer periphery of the pressing portion. A smooth elastic body,
An inkjet head position adjusting method, wherein the inkjet head is pressed by the elastic body by rotating the rotating shaft. In the inkjet head position adjustment method according to claim 4,
The ink jet head position adjusting method, wherein the pressing portion has a flat portion at a position where the pressing force to the ink jet head is maximized. The inkjet head position adjusting method according to claim 4 or 5,
The inkjet head position adjusting method, wherein the elastic body is an O-ring. In the inkjet head position adjustment method according to any one of claims 1 to 6,
When the inkjet head fixed to the head fixing portion is displaced, the reference pin arranged in the reference pin hole is changed to a reference pin having a position reference portion of another size according to the displacement. An inkjet head position adjusting method comprising a rearrangement step. In the inkjet head position adjustment method according to any one of claims 1 to 7,
When the inkjet head fixed to the head fixing portion is inclined, two or more reference pins in a direction orthogonal to the printing target conveyance direction are provided according to the inclination, and the reference has a position reference portion of a different size. An inkjet head position adjusting method comprising a step of rearranging the pins. In the inkjet head position adjustment method according to any one of claims 1 to 8,
The inkjet head position adjusting method, wherein the head fixing unit fixes a plurality of inkjet heads. In the inkjet head position adjustment method according to any one of claims 1 to 9,
The inkjet head position adjusting method, wherein the inkjet head is an inkjet head module in which a plurality of inkjet heads that eject ink droplets onto a printing target are arranged at preset positions. In an inkjet printing apparatus provided with a head fixing unit that fixes an inkjet head that ejects ink droplets onto a print target,
The head fixing part is
A head placement region in which the inkjet head is placed;
Three or more reference pin hole portions provided along the outer periphery of the head arrangement region, wherein any one of a plurality of reference pins having different sizes of the position reference portion in contact with the inkjet head is selectively detachable. When,
An ink jet printing apparatus comprising: The inkjet printing apparatus according to claim 11.
The head fixing portion includes a pressing pin hole portion that is individually provided to face the reference pin hole portion with the head arrangement region interposed therebetween, wherein a pressing pin that presses the inkjet head is detachably disposed. An inkjet printer characterized by the above. The inkjet printing apparatus according to claim 11 or 12,
The head fixing portion fixes a plurality of inkjet heads. The inkjet printing apparatus according to any one of claims 11 to 13,
The inkjet head is an inkjet head module in which a plurality of inkjet heads that eject ink droplets onto a printing target are arranged at preset positions.

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