CN115122773A - Head unit and inkjet printing apparatus - Google Patents

Abstract

The invention provides a head unit and an ink jet printing apparatus, which can simply and accurately adjust the position of an ink jet head. The head unit is provided with first to sixth heads (11-16) in which a plurality of nozzles for ejecting liquid onto a printing paper (P) are arranged in a predetermined direction, the first to sixth heads (12-16) are arranged in a direction orthogonal to the direction of arrangement of the nozzles along the relative conveying direction of the printing paper (P), and the nozzles of a part of the first and sixth heads (11, 16) and the nozzles of a part of the second to fourth heads (12-14) are arranged so as to be offset in the direction of arrangement of the nozzles so as to be positioned at the same position in the direction of arrangement of the nozzles.

Description

Head unit and inkjet printing device

technical field

The present invention relates to a head unit including a plurality of ejection portions that eject liquid, and an ink jet printing apparatus including the head unit.

Background technique

Conventionally, there have been proposed inkjet printing apparatuses that perform printing by ejecting ink from an inkjet head to a printing medium such as paper and film.

As an inkjet printing apparatus, for example, an inkjet printing apparatus has been proposed in which a head unit including a plurality of inkjet heads is moved in the main scanning direction to perform printing within a predetermined main scanning range, and the head unit is moved relative to the printing The medium is relatively moved in the sub-scanning direction orthogonal to the main-scanning direction, whereby printing in the above-described main-scanning range is sequentially performed.

Further, as a head unit used in such an inkjet printing apparatus, a head unit has been proposed in which a plurality of inkjet heads are shifted in the sub-scanning direction, and different liquids are ejected from the respective inkjet heads (for example, refer to Patent Documents). 1).

prior art literature

Patent Literature

Patent Document 1: Japanese Patent Laid-Open No. 2020-185737

SUMMARY OF THE INVENTION

The problem to be solved by the invention

Here, when printing is performed using the above-described head unit, the pretreatment liquid may be ejected from one inkjet head that is shifted in the sub-scanning direction, and the color ink may be ejected from the other inkjet head.

In such a case, first, after applying the pretreatment liquid to a predetermined main scanning range with one inkjet head, the head unit is moved relative to the printing medium in the sub-scanning direction. As a result, the inkjet head that ejects the color ink is arranged in the main scanning range where the pretreatment liquid is applied, and the color ink is ejected on the pretreatment liquid.

Therefore, only by the relative movement of the head unit in the sub-scanning direction, it is necessary to make the main scanning range of the pretreatment liquid and the main scanning range of the color ink match. The inkjet head is adjusted to a preset positional relationship.

When performing the position adjustment of the ink jet head, for example, a method based on the printing result of the ink jet head is considered. However, there are also pretreatment liquids that are transparent and cannot be visually recognized among the above-mentioned pretreatment liquids. In the inkjet head of the treatment liquid, the position of the inkjet head cannot be adjusted by checking the printing result as in the case of the color ink inkjet head.

An object of the present invention is to provide a head unit and an inkjet printing apparatus that can easily and accurately adjust the position of an inkjet head.

means of solving problems

The head unit of the present invention includes a plurality of ejection parts, a plurality of nozzles for ejecting liquid are arranged in a predetermined direction in the ejection part, and a first ejection of the plurality of ejection parts ejects mutually different liquids The nozzles and the second ejection portion are arranged side by side in a direction orthogonal to the arrangement direction of the nozzles, and a part of the nozzles of the first ejection portion and a part of the nozzles of the second ejection portion are at the same position in the arrangement direction of the nozzles. In a manner of staggering the arrangement direction of the nozzles, the arrangement direction of the nozzles is along the relative conveyance direction of the printing medium with respect to the plurality of ejection parts.

Invention effect

According to the head unit of the present invention, the first ejection portion and the second ejection portion are arranged so that the nozzles of a part of the first ejection portion and the nozzles of a part of the second ejection portion are at the same position in the nozzle arrangement direction. Since the ejection portions are shifted in the arrangement direction of the nozzles, the positional adjustment of the inkjet head can be performed simply and accurately. In addition, the position adjustment method of the inkjet head using such a structure is mentioned in detail later.

Description of drawings

FIG. 1 is a diagram showing a schematic configuration of an ink jet printing apparatus using an embodiment of the head unit of the present invention.

FIG. 2 is a view of the ink jet printing apparatus shown in FIG. 1 viewed from the direction of arrow A. FIG.

FIG. 3 is a plan view showing a schematic configuration of an example of a head unit.

FIG. 4 is a block diagram showing the configuration of a control system of the ink jet printing apparatus shown in FIG. 1 .

FIG. 5 is a diagram showing an example of a printing result when the sixth head is arranged exactly with respect to the third head.

FIG. 6 is a diagram showing an example of a printing result when the sixth head is arranged close to one line in the front-rear direction with respect to the third head.

FIG. 7 is a diagram showing an example of a print result when the sixth head is disposed away from one line or more in the front-rear direction with respect to the third head.

8 is a diagram showing an example of a position adjustment pin as a position adjustment mechanism of the sixth head.

Description of reference numerals

1: Inkjet printing device;

2: abutment;

2a: wheel;

3: base;

4: pressure plate;

4a: front paper guide;

4b: rear paper guide;

4c: vacuum chamber;

4d: fan;

5: track part;

6: drive roller;

7: pressure roller;

8: the core body holding part on the winding side;

8a: core body;

9: Supply-side core holding part;

9a: core body;

10: head unit;

10a: head bracket;

11 to 16: the first to the sixth;

17: Printing control device;

16a: position adjustment pin;

51: Main scan drive motor;

61: Carrying the drive motor;

81: winding drive motor;

91: Supply the drive motor;

P: Printing paper.

Detailed ways

Hereinafter, an ink jet printing apparatus using one embodiment of the head unit of the present invention will be described in detail with reference to the drawings. The inkjet printing apparatus of the present embodiment is characterized by the structure of the head unit. First, the overall structure of the inkjet printing apparatus will be described. FIG. 1 is a schematic configuration diagram of an inkjet printing apparatus 1 according to the present embodiment. In addition, FIG. 2 is the figure which looked at the inkjet printing apparatus 1 shown in FIG. 1 from the arrow A direction. In addition, in the description of the embodiment shown below, the up-down, left-right, front-rear direction indicated by the arrow in FIG.

As shown in FIG. 1 , the inkjet printing apparatus 1 of the present embodiment includes a base 2 , a chassis 3 , a platen 4 , a rail portion 5 , and a head unit 10 .

The base 2 is a columnar member extending in the front-rear direction, and is arranged in parallel with an interval in the left-right direction. Two wheels 2a are provided on the bottom surfaces of the two bases 2, respectively.

A base 3 is erected on each base 2 , respectively. Moreover, the pressure plate 4 is supported on the upper surfaces of the two bases 3 which face each other.

A front paper guide 4a and a rear paper guide 4b formed in an arc shape are extended in the front and rear of the platen 4 . Moreover, as shown in FIG. 2, the lower part of the platen 4 is provided with the vacuum chamber 4c provided with the fan 4d.

In addition, in FIG. 1, illustration of the vacuum chamber 4c is abbreviate|omitted.

When the fan 4d of the vacuum chamber 4c rotates, the inside of the vacuum chamber 4c becomes a negative pressure, and the suction hole (illustration omitted) formed in the platen 4 produces a suction|attraction force. The printing paper P is attracted to the platen 4 by the suction force generated in the suction holes of the platen 4 .

In addition, as shown in FIG. 2 , behind the platen 4 , the drive roller 6 and the pressure roller 7 are provided so as to face each other. In addition, in FIG. 1, illustration of the drive roller 6 and the pressure roller 7 is abbreviate|omitted.

The drive roller 6 is a long roller extending in the extending direction of the platen 4, and is rotated by a conveyance drive motor 61 (refer to FIG. 4) to be described later.

The pressure roller 7 is an elongated roller extending in the extending direction of the platen 4 like the driving roller 6 , and is supported so as to be able to move up and down by an elevating mechanism (not shown).

Then, the printing paper P on the rear paper guide 4b is nipped by the driving roller 6 and the pressing roller 7, and the driving roller 6 rotates while the printing paper P is pressed by the pressing roller 7, whereby the printing paper P is moved forward. send out.

On the front side of the base 2 of the inkjet printing apparatus 1 , a winding-side core holding portion 8 that detachably holds the core 8 a on which the printing paper P is wound is provided. The winding-side core holder 8 is connected to a winding drive motor 81 (see FIG. 4 ) via a torque limiter (not shown), and the winding-side core holder 8 is rotated by the winding drive motor 81 .

In addition, on the rear side of the base 2 of the inkjet printing apparatus 1, a supply-side core holding portion 9 is provided, and the supply-side core holding portion 9 is a core of a roll paper that winds the printing paper P into a roll. The body 9a is held detachably. The supply-side core holder 9 is connected to a supply drive motor 91 (see FIG. 4 ) via a torque limiter (not shown), and the supply-side core holder 9 is rotated by the supply drive motor 91 .

Then, as shown in FIG. 2 , the roll paper (printing paper P) held by the supply-side core holding portion 9 is pulled out and passed through the rear paper guide 4b, between the driving roller 6 and the pressure roller 7, The upper and front paper guides 4 a on the platen 4 are wound around the core 8 a held by the winding-side core holding portion 8 .

On the upper parts of the two bases 3, the rail part 5 is bridge|crossed via the support member which abbreviate|omitted illustration. The rail portion 5 includes a rail (not shown) extending in the left-right direction, and a main scanning drive motor 51 (see FIG. 4 ) that reciprocates the head unit 10 in the left-right direction on the rail.

Next, the head unit 10 of the present embodiment will be described. FIG. 3 is a plan view showing a schematic configuration of the head unit 10 .

As shown in FIG. 3 , the head unit 10 of the present embodiment includes six heads of the first head 11 to the sixth head 16 . The second head 12 , the third head 13 , the fourth head 14 , and the fifth head 15 are ink jet heads that eject inks of different colors, respectively. In this embodiment, as shown in FIG. 3 , the second head 12 ejects ink of Y (yellow), the third head 13 ejects ink of K (black), and the fourth head 14 ejects ink of M (magenta). For the ink, the fifth head 15 ejects ink of C (cyan).

The sixth head 16 has the same structure as the second head 12 to the fifth head 15, but the liquid to be ejected is not ink but a pretreatment liquid. The pretreatment liquid refers to a liquid to be applied for pretreatment before the ink is ejected to the printing paper P and the printing process is performed. As the pretreatment liquid, for example, a liquid for improving the color rendering property and uniform coating property of the ink is used, but a known pretreatment liquid can be used.

The first head 11 is an ink jet head that ejects ink similarly to the second head 12 to the fifth head 15 . For example, in the case of printing a pattern on a black base, the first head 11 ejects white ink on the black base to make the black base opaque.

As shown in FIG. 3 , the first head 11 to the sixth head 16 are arranged side by side in the moving direction (left-right direction) of the head unit 10, but the first head 11 and the second head 12 to the fifth head 15 are arranged in a staggered arrangement. The sixth head 16 and the second to fifth heads 12 to 15 are also staggered.

That is, the second head 12 to the fifth head 15 , the first head 11 , and the sixth head 16 are arranged at different positions in the direction (front-rear direction) orthogonal to the moving direction of the head unit 10 . Furthermore, the first head 11 and the sixth head 16 are arranged at the same position in the direction (the front-rear direction) orthogonal to the moving direction of the head unit 10 . In addition, the second head 12 to the fifth head 15 are also arranged at the same position in the direction (front-rear direction) orthogonal to the moving direction of the head unit 10 .

The first to sixth heads 11 to 16 are held by the head holder 10a, and the first to sixth heads 11 to 16 are provided so that their ejection surfaces are exposed from the head holder 10a.

The first to sixth heads 11 to 16 have a plurality of nozzles (indicated by circles in FIG. 3 ) that eject liquids such as ink or pretreatment liquid onto the printing paper P. As shown in FIG. The plurality of nozzles of the first head 11 to the sixth head 16 are arranged in the front-rear direction. In this embodiment, the front-rear direction is the arrangement direction of the nozzles, and is the conveyance direction of the printing paper P. As shown in FIG.

Furthermore, the first head 11 , the sixth head 16 , and the second head 12 to the fifth head 15 are shifted in the front-rear direction (the nozzle arrangement direction) as described above, but some of the nozzles of the first head 11 and the second head 12 - A part of nozzles of the 5th head 15 are arrange|positioned so that it may become the same position in the front-back direction. Further, a part of the nozzles of the sixth head 16 and a part of the nozzles of the second head 12 to the fifth head 15 are arranged so as to be at the same position in the front-rear direction.

In this embodiment, as shown in FIG. 3, the 1st head 11 and the 2nd head 12 - the 5th head 15 are arrange|positioned so that only one nozzle may be located in the same position in the front-back direction. In addition, the sixth head 16 and the second head 12 to the fifth head 15 are arranged so that only one nozzle is located at the same position in the front-rear direction.

Here, as in the present embodiment, when the first head 11 to the sixth head 16 are arranged in a shifted arrangement, for example, the first head 11 and the sixth head 16 and the second head 12 to the fifth head 15 need to scan the same scan. range, so their positional relationship needs to be adjusted accurately. In the present embodiment, by arranging the first head 11, the sixth head 16, and the second head 12 to the fifth head 15 so that only one nozzle is at the same position in the front-rear direction as described above, it is possible to simplify and accurately The adjustment of the above-mentioned positional relationship is carried out. In addition, the adjustment method of the positional relationship of the 1st head 11, the 6th head 16, and the 2nd head 12 - the 5th head 15 will be described in detail later.

FIG. 4 is a block diagram showing the configuration of a control system of the inkjet printing apparatus 1 according to the present embodiment. The inkjet printing apparatus 1 operates each part of the control target shown in FIG. 4 based on the control signal from the printing control apparatus 17 .

The printing control device 17 and the inkjet printing device 1 are connected by a communication line such as a LAN (Local Area Network) or an Internet line, and are configured to be able to communicate with each other. The communication line can be wired or wireless.

The printing control device 17 is constituted by a computer including a CPU (Central Processing Unit), a semiconductor memory, a hard disk, and the like. The print control device 17 executes a print control program pre-stored in a storage medium such as a semiconductor memory or a hard disk based on an input print job or the like, and controls each part shown in FIG. 4 by operating a circuit.

Next, the printing operation of the inkjet printing apparatus 1 of the present embodiment will be described. It should be noted that, here, a description will be given of a case where, without using the first head 11 , the pretreatment liquid is ejected from the sixth head 16 and applied to the printing paper P, and thereafter, the second head 12 - The case where the fifth head 15 ejects ink and performs printing on the printing paper P to which the pretreatment liquid is applied.

First, as shown in FIG. 2 , a roll paper is set on the supply-side core holder 9 , and the roll paper (printing paper P) is pulled out and passed through the rear paper guide 4 b , between the driving roller 6 and the pressure roller 7 , The upper and front paper guides 4 a on the platen 4 are wound around the core 8 a held by the winding-side core holding portion 8 .

Then, the printing control device 17 sends out the printing paper P by rotating the supply-side core holding portion 9 , the winding-side core holding portion 8 , and the drive roller 6 , and temporarily stops the feeding of the printing paper P when the printing initial position is reached.

Next, the print control device 17 operates the main scanning drive motor 51 to move the head unit 10 in the first direction (any one of the left and right directions) on the rail portion 5 . Then, the printing control device 17 operates the sixth head 16 of the head unit 10 while the head unit 10 is moving, and applies the pretreatment liquid to the first scanning line. It should be noted that, in the first scanning of the first scanning line, the ejection of ink from the second head 12 to the fifth head 15 is not performed.

Next, the printing control device 17 sends out the printing paper P by one scanning line so that the first scanning line to which the pretreatment liquid is applied is arranged directly below the second head 12 to the fifth head 15 .

Then, the print control device 17 moves the head unit 10 in a second direction opposite to the first direction on the rail portion 5, and simultaneously with this movement, ejects ink from the second head 12 to the fifth head 15 to The first scan line performs printing. In addition, the printing control device 17 performs printing on the first scanning line, and operates the sixth head 16 to apply the pretreatment liquid to the second scanning line following the first scanning line.

Next, the printing control device 17 sends out the printing paper P by one scanning line to the second head 12-

The second scanning line is arranged directly under the fifth head 15 , and the third scanning line following the second scanning line is arranged directly under the sixth head 16 .

Then, the print control device 17 moves the head unit 10 in the first direction on the rail portion 5, and operates the second head 12 to the fifth head 15 and the sixth head 16 at the same time as the movement, so that the third head unit 10 is moved in the third direction. The pretreatment liquid is applied to the scan line, and printing is performed on the second scan line.

Thereafter, similarly to the above, the printing control device 17 sequentially repeats the feeding of the printing paper P for one scanning line and the movement of the head unit 10 on the rail portion 5 in the first direction or the second direction. Application of the pretreatment liquid to the n+1th scan line and printing to the nth scan line.

In addition, in the above description, the operation in the case where the pretreatment liquid is applied by the sixth head 16 without using the first head 11 has been described, but the sixth head 16 may be used instead of the first head 16 . The head 11 prints the substrate. The ejection time of the ink from the first head 11 in this case is the same as the ejection time of the sixth head 16 in the above description.

Next, the position adjustment of the 1st head 11 - the 6th head 16 performed before the above-mentioned printing operation is demonstrated. It should be noted that, in this embodiment, the second head 12 to the fifth head 15 are arranged at the same position in the front-rear direction, and the position of the sixth head 16 is adjusted relative to the position of the second head 12 to the fifth head 15 . The method of location will be explained. In addition, in this embodiment, the 3rd head 13 and the 6th head 16 correspond to the 1st ejection part and the 2nd ejection part in this invention.

The sixth head 16 discharges the pretreatment liquid as described above, but depending on the type of the pretreatment liquid, it cannot be visually recognized even if printing is performed. Therefore, it is very difficult to adjust the position of the sixth head 16 using only the application result of the pretreatment liquid.

In contrast, in the present embodiment, in one scan of the head unit 10 in the first direction or the second direction, the pretreatment liquid is ejected from the sixth head 16 and the ink of K is ejected from the third head 13 out.

In the present embodiment, as described above, the third head 13 (the second head 12 to the fifth head 15 ) and the sixth head 16 are arranged so that only one nozzle is at the same position in the front-rear direction. Therefore, when the third head 13 (the second head 12 to the fifth head 15 ) and the sixth head 16 are accurately arranged, by one scan of the head unit 10, both the pretreatment liquid and the ink of K are It is ejected to the same point on a line in the same position in the front-rear direction.

In this way, when both the pretreatment liquid and the K ink are ejected to the same spot in one scan of the head unit 10, the K ink is ejected to the pretreatment liquid before the pretreatment liquid dries. Therefore, the K ink bleeds by the pretreatment liquid, and the shape of the dots changes compared with the case where the K ink is ejected to the part where the pretreatment liquid is not ejected. For example, the size of the dots and the unevenness (degree of perfect circle) change.

Specifically, as shown in FIG. 3 , when the sixth head 16 is accurately arranged with respect to the third head 13 (the second head 12 to the fifth head 15 ), that is, only the dots on one line are ejected. In the case of both the pretreatment liquid and the K ink, as shown in FIG. 5 , the dots of K on the line where the pretreatment liquid was ejected were deformed by bleeding. On the other hand, among the nozzles of the third head 13, the point K formed by the nozzles that are not arranged in the same position as the nozzles of the sixth head 16 in the front-rear direction does not cause bleeding due to the pretreatment liquid, so that the It becomes a shape close to a perfect circle without being deformed.

Therefore, in the case of the printing result shown in FIG. 5 , it can be determined that the sixth head 16 is correctly arranged with respect to the third head 13 (the second head 12 to the fifth head 15 ), and it is not necessary to The position of the head 16 is adjusted.

On the other hand, for example, as shown in FIG. 6 , when the point of K deformed by color bleeding is two lines, it can be determined that the sixth head 16 is relative to the third head 13 (the second head 12 to the fifth head 12 to the fifth head 13 ). The head 15) is arranged close to one line in the front-rear direction.

Therefore, in the case of the printing result as shown in FIG. 6 , the position of the sixth head 16 is adjusted by moving the sixth head 16 by one line in the direction in which the sixth head 16 is separated from the third head 13 .

In addition, for example, as shown in FIG. 7 , when there is no point of K deformed by bleeding, it can be determined that the sixth head 16 is in front of and behind the third head 13 (the second head 12 to the fifth head 15 ). It is arranged to be more than one line away in the direction.

Therefore, in the case of the printing result as shown in FIG. 7 , the sixth head 16 is moved a predetermined distance in the direction in which the sixth head 16 approaches the third head 13 , the head unit 10 is scanned once again, and the ejection Both the pretreatment liquid and the K ink are dispensed, the printing results thereof are confirmed, and the position of the sixth head 16 is appropriately adjusted.

It should be noted that, in actual printing, in one scan, the discharge range (scanning range) of the pretreatment liquid of the sixth head 16 and the ink discharge range (scanning range) of the second head 12 to the fifth head 15 However, the second head 12 to the fifth head 15 do not necessarily eject the ink in a continuous line, but eject the ink at intervals, so the above-mentioned bleeding does not become a problem. In addition, when printing is actually performed, the sixth head 16 and the second head 12 to the fifth head 15 do not need to discharge the pretreatment liquid or ink for the range of the amount of one nozzle that is repeated in one scan. .

In addition, regarding the position adjustment of the sixth head 16 , for example, as shown in FIG. 8 , the position adjustment pin 16 a may be provided at the end of the sixth head 16 . The position adjustment pin 16a is formed in a cylindrical shape and extends in the up-down direction. Furthermore, the rotation axis of the position adjustment pin 16 a is eccentric in the longitudinal direction (front-rear direction) of the sixth head portion 16 . Thereby, by rotating the position adjustment pin 16a in the arrow direction shown in FIG. 8, the position of the sixth head 16 in the front-rear direction can be adjusted. In addition, the position adjustment mechanism of the sixth head 16 is not limited to the above-mentioned position adjustment pin 16a, and other well-known mechanisms can be used.

In addition, in the above-described embodiment, the method for adjusting the position of the sixth head 16 that ejects the pretreatment liquid that cannot be visually recognized has been described, but the first head 11 also ejects the liquid that cannot be visually recognized. Next, similarly to the sixth head 16, both the liquid ejection from the first head 11 and the K ink ejection from the third head 13 are performed in one scan, and the printing result of the K ink is checked by checking the (bleeding degree), its position can be adjusted. For example, in the above-mentioned embodiment, the example in which the white ink is ejected from the first head 11 on the black substrate has been described, but when the first head 11 ejects the white ink on the white substrate, the white ink Since the ink cannot be visually confirmed, the above-mentioned position adjustment method can be used.

In addition, in the above-described embodiment, the example in which the pretreatment liquid is ejected from the sixth head 16 has been described, but the transparent liquid that cannot be visually confirmed is not limited to the pretreatment liquid, and there is also an overcoat ink. Wait.

According to the ink jet printing apparatus 1 of the above-described embodiment, the nozzles of a part of the first head 11 and the sixth head 16 and the nozzles of a part of the second head 12 to the fifth head 15 are arranged at the same position in the front-rear direction, Therefore, for example, as described above, the third head 13 and the sixth head 16 eject both the ink and the pretreatment liquid to the same point in one scan, and by confirming the printing results, it is possible to easily and accurately adjust the relative position of the sixth head 16 to the same point. The positions of the second head 12 to the fifth head 15 .

In addition, in the above-described embodiment, the third head 13 ejects the K ink that can be visually recognized, and the sixth head 16 ejects the pretreatment liquid that cannot be visually recognized. The position of the sixth head 16 of the pretreatment liquid can also be easily and accurately adjusted.

In addition, in the above-described embodiment, the third head 13 (the second head 12 to the fifth head 15 ) and the sixth head 16 are arranged so that only one nozzle is located at the same position in the front-rear direction, so the number of third heads can be reduced as much as possible. A portion where the nozzles of the head 13 and the nozzles of the sixth head 16 overlap in the front-rear direction.

Here, the more the nozzles of the third head 13 and the nozzles of the sixth head 16 overlap in the front-rear direction, the more the pretreatment liquid ejected from the sixth head 16 affects the ink ejected from the third head 13 bigger. That is, the pretreatment liquid ejected from the sixth head 16 and the ink ejected from the third head 13 are mixed and solidified on the ink ejection surface of the third head 13, which may lead to poor ejection of the ink.

As described above, by reducing as much as possible the overlapping portion of the nozzles of the third head 13 and the nozzles of the sixth head 16 in the front-rear direction (the amount of one nozzle), it is possible to prevent the above-described ink ejection failure. However, in the present invention, the portion overlapping in the front-rear direction is not limited to one nozzle, and may be, for example, two nozzles. Whether or not the overlapped portion increases may be appropriately determined according to the distance in the left-right direction between the second head 12 to the fifth head 15 that ejects the ink and the sixth head 16 that ejects the pretreatment liquid.

In addition, in the above-mentioned embodiment, since the position of the sixth head 16 in the front-rear direction can be adjusted by the position adjustment pin 16a, the position adjustment of the sixth head 16 can be easily performed.

In addition, in the above-described embodiment, since the head unit 10 is configured to be movable in the left-right direction, by confirming the printing result of the line typed by one scan, it is possible to more accurately recognize the bleeding at the K point as described above, and it is possible to Make more accurate position adjustments.

Regarding the present invention, the following supplementary notes are further disclosed.

(Additional note)

In the head unit of the present invention, one of the first ejection portion and the second ejection portion can eject ink that can be visually recognized, and the other ejection portion can eject ink that cannot be visually recognized. liquid.

In the head unit of the present invention, the first ejection portion and the second ejection portion can be arranged so that only one nozzle is located at the same position in the arrangement direction of the nozzles.

In the head unit of the present invention, it is preferable that at least one of the first ejection portion and the second ejection portion is configured so that the position in the arrangement direction of the nozzles can be adjusted.

The head unit of the present invention can be configured to be movable in a direction orthogonal to the arrangement direction of the nozzles.

The inkjet printing apparatus of the present invention includes the above-described head unit, and performs printing by ejecting ink from the ejection portion of the head unit to the printing medium.

Claims (6)

1. A head unit in which, in a head unit,

the head unit includes a plurality of discharge portions in which a plurality of nozzles for discharging a liquid are arranged in a predetermined direction,

the first discharge unit and the second discharge unit, which discharge different liquids, of the plurality of discharge units are arranged side by side in a direction orthogonal to the arrangement direction of the nozzles, and are arranged offset in the arrangement direction of the nozzles such that a part of the nozzles of the first discharge unit and a part of the nozzles of the second discharge unit are positioned at the same position in the arrangement direction of the nozzles, the arrangement direction of the nozzles being along a relative conveyance direction of the printing medium with respect to the plurality of discharge units.

2. The head unit according to claim 1, wherein one of the first discharge portion and the second discharge portion discharges ink that can be visually confirmed, and the other discharge portion discharges liquid that cannot be visually confirmed.

3. The head unit according to claim 1 or 2, wherein the first ejection portion and the second ejection portion are arranged such that only one nozzle is at the same position in the direction in which the nozzles are arranged.

4. The head unit according to any one of claims 1 to 3, wherein at least one of the first ejection portion and the second ejection portion is configured to be adjustable in position in an arrangement direction of the nozzles.

5. The head unit according to any one of claims 1 to 4, wherein the head unit is configured to be movable in a direction orthogonal to an arrangement direction of the nozzles.

6. An ink-jet printing apparatus, wherein,

the inkjet printing apparatus is provided with the head unit according to any one of claims 1 to 5,

and performing printing by discharging ink from the discharge portion of the head unit to the print medium.

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