Inkjet printing equipment

Abstract

To provide an inkjet printing apparatus that can be adjusted to an appropriate head gap across the entire printing area. [Solution] The transport unit 2 is located below the inkjet head 26 and transports the paper P. Each of the multiple abutment mechanism units 5 has an abutment shaft 45 whose lower end abuts against the transport unit 2, and the height position of the abutment shaft 45 can be individually adjusted steplessly.

Description

Technical Field

[0001] The present invention relates to an inkjet printing apparatus.

Background Art

[0002] In an inkjet printing apparatus, the smaller the head gap, which is the distance between the inkjet head and a printing medium such as paper, the better the landing accuracy of the ink, and thus excellent image performance can be obtained. However, the smaller the head gap, the more likely it is that the printing medium will collide with the inkjet head, etc., resulting in a decrease in paper passing performance.

[0003] On the other hand, the larger the head gap, the better the paper passing performance. However, the larger the head gap, the more likely it is that the landing accuracy of the ink will decrease and the printing surface will be soiled by ink mist, resulting in a decrease in image performance.

[0004] Therefore, it is necessary to adjust the head gap to a size suitable for printing settings such as the type of printing medium and the printing image quality in order to achieve both image performance and paper passing performance.

[0005] As a technique for adjusting the head gap, Patent Document 1 discloses an inkjet recording apparatus provided with an adjustment mechanism for adjusting the distance between a conveyance unit and a head unit in multiple steps. However, in the technique of Patent Document 1, since it is a stepwise adjustment, it may not be possible to adjust to an appropriate head gap.

[0006] On the other hand, as a technique for adjusting the head gap continuously, there is one disclosed in Patent Document 2. In the recording apparatus of Patent Document 2, eccentric cams are fixed to one end and the other end of a guide shaft that supports a carriage provided with a recording head, and the height of the guide shaft can be adjusted continuously by the rotation of the eccentric cams due to the axial rotation of the guide shaft. Thereby, it is possible to continuously adjust the head gap, which is the distance between the recording head and the medium supported by the support member.

Prior Art Documents

Patent Documents

[0007] [Patent Document 1] Japanese Patent Publication No. 2020-82551 [Patent Document 2] Japanese Patent Publication No. 2021-142740 [Overview of the Initiative] [Problems that the invention aims to solve]

[0008] In the technology described in Patent Document 2, since the two eccentric cams fixed to both ends of the guide shaft are synchronized, it is not possible to correct the inclination of the support member relative to the recording head due to variations in the dimensional accuracy or assembly accuracy of the parts.

[0009] Here, if the dimensional accuracy and assembly accuracy of the parts are high, the tilt of the support member relative to the recording head as described above can be suppressed. However, there are cases where the tilt of the support member relative to the recording head occurs because the dimensional accuracy and assembly accuracy of the parts are insufficient. In this case, as described above, the technology of Patent Document 2 cannot correct this tilt, and as a result, it may not be possible to adjust the head gap appropriately across the entire printing area.

[0010] The present invention has been made in view of the above, and aims to provide an inkjet printing apparatus that can be adjusted to an appropriate head gap across the entire printing area. [Means for solving the problem]

[0011] To achieve the above objective, the inkjet printing apparatus of the present invention is characterized by comprising an inkjet head, a transport unit disposed below the inkjet head for transporting a printing medium, and a plurality of abutment mechanisms, each having an abutment shaft whose lower end abuts against the transport unit, and the height position of the abutment shaft being individually and infinitely adjustable. [Effects of the Invention]

[0012] According to the present invention, it is possible to provide an inkjet printing apparatus that can be adjusted to an appropriate head gap across the entire printing area. [Brief explanation of the drawing]

[0013] [Figure 1] This is a schematic diagram of an inkjet printing apparatus according to an embodiment. [Figure 2] Figure 1 is a control block diagram of the inkjet printing apparatus. [Figure 3] Figure 1 is a perspective view showing the schematic configuration of the printing section of the inkjet printing apparatus. [Figure 4] Figure 1 is a perspective view showing the schematic configuration of the stopper mechanism of the inkjet printing apparatus. [Figure 5] (a) to (e) are diagrams illustrating the operation of adjusting the distance between the head transport surfaces. [Figure 6] This figure shows an example where the abutment shafts of some abutment mechanisms are positioned at a different height than the abutment shafts of other abutment mechanisms. [Modes for carrying out the invention]

[0014] Embodiments of the present invention will be described below with reference to the drawings. Throughout the drawings, the same or equivalent parts and components are denoted by the same or equivalent reference numerals.

[0015] The embodiments shown below illustrate devices and the like that embody the technical concept of this invention, and the technical concept of this invention does not limit the materials, shapes, structures, arrangements, etc. of each component to those described below. The technical concept of this invention can be modified in various ways within the scope of the claims.

[0016] FIG. 1 is a schematic configuration diagram of an inkjet printing apparatus according to an embodiment of the present invention. FIG. 2 is a control block diagram of the inkjet printing apparatus shown in FIG. 1. FIG. 3 is a perspective view showing a schematic configuration of a printing unit of the inkjet printing apparatus shown in FIG. 1. FIG. 4 is a perspective view showing a schematic configuration of a contact mechanism unit of the inkjet printing apparatus shown in FIG. 1. In the following description, the direction orthogonal to the plane of FIG. 1 is defined as the front-rear direction. Also, the up-down, left-right directions in the plane of FIG. 1 are defined as the up-down, left-right directions, respectively.

[0017] As shown in FIGS. 1 and 2, an inkjet printing apparatus 1 according to the present embodiment includes a conveyance unit 2, a printing unit 3, a lifting mechanism unit 4, four contact mechanism units 5, four displacement sensors 6, and a control unit 7.

[0018] The conveyance unit 2 conveys a sheet P, which is a printing medium fed from a paper feeding unit (not shown). The conveyance unit 2 is disposed below the printing unit 3. The conveyance unit 2 includes a conveyance belt 11, a drive roller 12, driven rollers 13 to 15, a platen 16, a platen plate 17, and a suction unit 18.

[0019] The conveyance belt 11 adsorbs and holds the sheet P conveyed by the paper feeding unit and conveys it. The conveyance belt 11 is an annular belt wound around the drive roller 12 and the driven rollers 13 to 15. A number of belt holes (not shown), which are through holes for air suction, are formed in the conveyance belt 11. The conveyance belt 11 adsorbs and holds the sheet P on the conveyance surface 11a by the suction force generated in the belt holes due to the driving of a fan 22 of the suction unit 18 described later. The conveyance surface 11a is the surface on which the sheet P is placed on the conveyance belt 11, and is the upper surface of the planar portion of the conveyance belt 11 between the drive roller 12 and the driven roller 13. The conveyance belt 11 rotates (runs endlessly) in the clockwise direction in FIG. 1 to convey the adsorbed and held sheet P in the conveyance direction from left to right.

[0020] The drive roller 12 rotates the conveyance belt 11. The drive roller 12 is rotationally driven by a motor (not shown).

[0021] The driven rollers 13-15 support the conveyor belt 11 together with the drive roller 12. The driven rollers 13-15 rotate in accordance with the conveyor belt 11. Driven roller 13 is positioned at the same height as the drive roller 12 and to the left of the drive roller 12. Driven rollers 14 and 15 are positioned below the drive roller 12 and driven roller 13, spaced apart from each other in the left-right direction and at the same height.

[0022] The platen 16 is a flat, plate-like member positioned below the conveyor belt 11 between the drive roller 12 and the driven roller 13, and slidably supports the conveyor belt 11. The platen 16 is rectangular in shape when viewed from above. The platen 16 has multiple through holes to allow air drawn in by the fan 22 to pass through.

[0023] The platen template 17 is a flat, plate-like member positioned below the platen 16 and supporting the platen 16 via several spacers (not shown). The platen template 17 is rectangular in shape when viewed from above. The platen template 17 has several through holes to allow air drawn in by the fan 22 to pass through. The upper surface of the platen template 17 is abutment surface 17a against which the tip (lower end) of the abutment shaft 45 of the abutment mechanism 5, which will be described later, abuts. The platen template 17 is larger than the conveyor belt 11 and the platen 16 in the front-rear direction.

[0024] The suction unit 18 draws air through the through-holes in the plastic template 17, the through-holes in the platen 16, and the belt holes in the conveyor belt 11 to cause the paper P to adhere to the conveyor belt 11. The suction unit 18 comprises a chamber 21 and a fan 22.

[0025] Chamber 21 forms a negative pressure chamber to generate suction force in the belt holes of the conveyor belt 11. Chamber 21 is located on the back side of the plastic template 17.

[0026] Fan 22 exhausts air from chamber 21. As a result, fan 22 draws air through the through holes in the plastic template 17, the platen 16, and the belt holes in the conveyor belt 11, generating suction force at the belt holes and causing the paper P to adhere to the conveyor belt 11.

[0027] The printing unit 3 prints on the paper P transported by the transport unit 2. As shown in Figures 1 and 3, the printing unit 3 is equipped with multiple inkjet heads 26 and a head holder 27.

[0028] The inkjet head 26 ejects ink onto the paper P. The inkjet head 26 has a plurality of nozzles (not shown) that open onto the nozzle surface 26a, which is the lower surface facing the transport surface 11a of the transport belt 11, and ejects ink from the nozzles. In this embodiment, 18 inkjet heads 26 are provided, arranged in a staggered pattern.

[0029] The head holder 27 holds the inkjet head 26. The head holder 27 holds the inkjet head 26 by allowing its lower end to protrude downward from its lower surface 27a. The head holder 27 is formed in a rectangular shape when viewed from above.

[0030] The lifting mechanism 4 raises and lowers the conveying section 2. The lifting mechanism 4 includes a wire 31 and a winding mechanism 32.

[0031] The wire 31 suspends and supports the conveying section 2. The wire 31 is inserted through a through hole formed in the abutment shaft 45 of each abutment mechanism 5, and its tip (lower end) is connected to the plastic template 17.

[0032] The winding mechanism 32 raises and lowers the conveying unit 2 by winding and unwinding the wire 31.

[0033] The stop mechanism 5 defines the head transport surface distance H. The head transport surface distance H is the distance between the nozzle surface 26a of the inkjet head 26 and the transport surface 11a of the transport belt 11. In other words, the head transport surface distance H is obtained by subtracting the thickness of the paper P from the head gap, which is the distance between the nozzle surface 26a and the paper P on the transport surface 11a.

[0034] As shown in Figure 3, the stopper mechanism 5 is positioned one at each of the four corners of the head holder 27.

[0035] As shown in Figure 4, the abutment mechanism 5 comprises an abutment motor (corresponding to the drive unit) 41, a worm 42, an intermediate gear 43, an abutment gear 44, an abutment shaft 45, a nut 46, and a reference block 47.

[0036] The abutment motor 41 rotates the abutment shaft 45 via a worm gear 42, an intermediate gear 43, and an abutment gear 44, thereby changing the height position of the abutment shaft 45. Forward rotation of the abutment motor 41 lowers the abutment shaft 45, and reverse rotation raises the abutment shaft 45. The abutment motor 41 consists of a pulse motor.

[0037] The worm gear 42 transmits the driving force of the stop motor 41 to the intermediate gear 43. The worm gear 42 is fixed to the output shaft of the stop motor 41.

[0038] The intermediate gear 43 transmits the driving force of the abutment motor 41 from the worm 42 to the abutment gear 44. The intermediate gear 43 is composed of a two-stage gear consisting of a worm wheel 48 that meshes with the worm 42 and a lower gear 49 which is a spur gear that meshes with the abutment gear 44.

[0039] The abutment gear 44 rotates together with the abutment shaft 45 due to the driving force of the abutment motor 41 transmitted from the intermediate gear 43. The abutment gear 44 is integrally formed with the abutment shaft 45 so as to surround the upper end of the abutment shaft 45. The abutment gear 44 consists of a spur gear that meshes with the lower gear 49.

[0040] The abutment shaft 45 is a component whose lower end abuts against the conveying section 2. Specifically, the lower end of the abutment shaft 45 abuts against the abutment surface 17a of the plastic template 17. The abutment shaft 45 is formed by a screw and screwed into a nut 46. This changes the height position of the abutment shaft 45, which rotates when driven by the abutment motor 41. As a result, the distance H between the head conveying surfaces can be changed when the lower end of the abutment shaft 45 abuts against the conveying section 2.

[0041] The abutment shaft 45 has a through hole formed in its axial direction, through which the wire 31 is inserted.

[0042] The height position of the abutment shaft 45 of each abutment mechanism 5 can be individually adjusted steplessly by driving each abutment motor 41. Here, the abutment shaft 45 moves up and down by an amount of movement corresponding to the number of drive pulses of the abutment motor 41, but the amount of movement of the abutment shaft 45 for one drive pulse is small enough that the height position of the abutment shaft 45 can be considered to be continuously adjustable.

[0043] The nut 46 is used to change the height position of the rotating abutment shaft 45. The nut 46 is fixed to the lower surface 27a of the head holder 27.

[0044] The reference block 47 defines the reference height position of the abutment shaft 45. The abutment shaft 45 is positioned at the reference height position when its upper end abuts against the reference block 47 and stops.

[0045] The displacement sensor 6 is positioned on the lower surface 27a of the head holder 27 near the abutment mechanism 5 and detects the distance from the displacement sensor 6 to the abutment surface 17a of the plastic template 17. One displacement sensor 6 is positioned near each of the four abutment mechanisms 5.

[0046] The control unit 7 controls the operation of each part of the inkjet printing device 1. The control unit 7 is composed of a CPU, RAM, ROM, hard disk, etc.

[0047] Next, the operation of adjusting the distance H between the head transport surfaces in the inkjet printing apparatus 1 will be explained with reference to Figure 5.

[0048] Figure 5(a) shows a state in which the height position of the abutment shaft 45 of each abutment mechanism 5 is unknown, such as when the inkjet printing device 1 is powered on. In this state, the transport unit 2 is positioned below the lower end of the abutment shaft 45.

[0049] From the state shown in Figure 5(a), the control unit 7 reverses the drive of the abutment motors 41 of each abutment mechanism 5 to raise the abutment shaft 45 as shown in Figure 5(b).

[0050] At this time, the control unit 7 drives the abutment motor 41 in reverse for a predetermined time. As a result, as shown in Figure 5(c), the abutment shaft 45 abuts against the reference block 47, the abutment motor 41 loses step, and the abutment shaft 45 stops at the reference height position.

[0051] Next, the control unit 7 drives the abutment motor 41 of each abutment mechanism 5 in the forward direction to lower the abutment shaft 45, as shown in Figure 5(d). At this time, the control unit 7 drives the abutment motor 41 in the forward direction for the number of drive pulses required to lower the abutment shaft 45 to the target height position. As a result, the abutment shaft 45 of each abutment mechanism 5 is lowered to the target height position.

[0052] Here, the target height position of the abutment axis 45 is the height position where the distance H between the head transport surfaces is equal to the target value. In addition, the number of drive pulses mentioned above includes a correction value for the number of drive pulses, which will be described later.

[0053] Next, the control unit 7 raises the transport unit 2 using the lifting mechanism 4, causing the abutment shaft 45 to abut against the plastic template 17. This brings the head transport surface distance H to the target value, and the adjustment of the head transport surface distance H is completed.

[0054] In this inkjet printer 1, two printing modes are selectable: a paper feed performance priority mode and an image performance priority mode. The printing mode can be selected, for example, by the user operating an operation input unit (not shown).

[0055] The paper feeding performance priority mode is a printing mode that prioritizes paper feeding performance over image performance. The image performance priority mode is a printing mode that prioritizes image performance over paper feeding performance. Paper feeding performance indicates how unlikely it is for transport problems such as paper P colliding with the inkjet head 26 to occur. Image performance indicates print quality. Paper feeding performance improves as the head gap increases, and image performance improves as the head gap decreases.

[0056] Furthermore, the thicker the paper P, the smaller the head gap becomes, even if the distance H between the head transport surfaces remains the same.

[0057] Therefore, the target value of the head transport distance H described above is set according to the paper type (paper thickness) and printing mode. Consequently, the inkjet printer 1 can adjust the head gap according to the paper type and printing mode.

[0058] Next, we will explain the correction value for the number of drive pulses of the aforementioned stop motor 41.

[0059] In the inkjet printing apparatus 1, variations in the dimensional accuracy and assembly accuracy of components involved in the distance H between the head transport surfaces in the head holder 27, transport unit 2, and abutment mechanism unit 5 may result in variations in the reference height position of the abutment shaft 45 of each abutment mechanism unit 5.

[0060] Therefore, even if the abutment shaft 45 of each abutment mechanism 5 is brought into contact with the reference block 47 and then lowered for the same number of drive pulses corresponding to the target height position, the height position of the abutment shaft 45 may deviate from the target height position. As a result, when the abutment shaft 45 of each abutment mechanism 5 is brought into contact with the transport unit 2, a tilt may occur on the transport surface 11a, and it may not be possible to adjust the head gap appropriately across the entire printing area.

[0061] Therefore, the inkjet printing device 1 calculates a correction value for the number of drive pulses of the stopper motor 41 in order to correct the height position of the stopper shaft 45.

[0062] Specifically, for example, when the inkjet printing device 1 is first started up, the control unit 7 raises the abutment shaft 45 of each abutment mechanism 5 from the state shown in Figure 5(a) as shown in Figure 5(b), and stops it at the reference height position as shown in Figure 5(c).

[0063] Next, the control unit 7 raises the transport unit 2 using the lifting mechanism unit 4, causing the abutment shaft 45 to abut against the plastic template 17.

[0064] Next, the control unit 7 obtains the distance from each displacement sensor 6 to the abutment surface 17a of the plastic template 17.

[0065] Next, the control unit 7 calculates the difference between the distance obtained from each displacement sensor 6 and the theoretical distance from the displacement sensor 6 to the abutment surface 17a when the plastic template 17 is abutting against the abutment shaft 45 positioned at the reference height. This difference indicates the amount of deviation of the reference height position of the abutment shaft 45 from its theoretical value. This difference is positive if the reference height position of the abutment shaft 45 is shifted downward from its design position, and negative if it is shifted upward.

[0066] Next, the control unit 7 calculates the number of drive pulses required to move the abutment shaft 45 by the magnitude of the difference value corresponding to each displacement sensor 6.

[0067] Then, the control unit 7 calculates a value for each displacement sensor 6 in which the calculated drive pulse count has the opposite sign to the sign of the difference value, and uses this value as a correction value for the drive pulse count of the abutment motor 41 of the abutment mechanism 5 near the displacement sensor 6.

[0068] The correction value for the number of drive pulses of the stop motor 41 of each stop mechanism 5, calculated in this manner, is used in the operation to adjust the head transport surface distance H described above.

[0069] In other words, when lowering the stopper shaft 45 from the reference height position, the control unit 7 drives the stopper motor 41 in the forward direction for a number of drive pulses equal to the theoretical value of the number of drive pulses required to lower the stopper shaft 45 to the target height position plus the correction value mentioned above. As a result, even if there are variations in the reference height position of the stopper shaft 45 of each stopper mechanism 5, the height position of the stopper shaft 45 of each stopper mechanism 5 can be made uniform, and tilting of the transport surface 11a can be suppressed. As a result, the head gap can be adjusted to an appropriate level across the entire printing area of ​​the paper P.

[0070] By the way, in the inkjet printing device 1, there are cases where it is desirable to position the stopper shafts 45 of each stopper mechanism 5 at individual height positions.

[0071] For example, due to errors in the height position of each inkjet head 26 attached to the head holder 27, as shown in Figure 6, the amount of protrusion from the head holder 27 is greater for the left inkjet head 26, and there is an inclination in the height position of the multiple inkjet heads 26 in the printing unit 3. In this case, if the transport surface 11a is horizontal, the transport surface 11a will be inclined with respect to the height arrangement of the multiple inkjet heads 26 in the printing unit 3.

[0072] In this case, the control unit 7 adjusts the height position of the abutment shafts 45 of each abutment mechanism 5 so that the abutment shafts 45 of the abutment mechanisms 5 at the two left corners are positioned lower than the abutment shafts 45 of the abutment mechanisms 5 at the two right corners, and the distance H between the head transport surfaces at the position of each inkjet head 26 becomes approximately uniform. This corrects the inclination of the transport surface 11a relative to the multiple inkjet heads 26 of the printing unit 3, making it possible to adjust to an appropriate head gap across the entire printing area of ​​the paper P.

[0073] As described above, the inkjet printing apparatus 1 has four abutment mechanisms 5, each having a stopper shaft 45 whose lower end abuts against the transport section 2, and the height position of the abutment shaft 45 can be individually adjusted steplessly. Because the height position of the abutment shaft 45 can be adjusted steplessly, the distance H between the head transport surfaces can be adjusted steplessly. Furthermore, because the height position of the abutment shaft 45 of the four abutment mechanisms 5 can be adjusted individually, even if there are variations in the dimensional accuracy and assembly accuracy of the parts involved in the distance H between the head transport surfaces, it is possible to suppress the occurrence of tilting on the transport surface 11a. It is also possible to accommodate cases where it is desired to place the abutment shaft 45 of each abutment mechanism 5 at individual height positions. Therefore, with the inkjet printing apparatus 1, it is possible to adjust to an appropriate head gap over the entire printing range of the paper P.

[0074] Furthermore, in the inkjet printing apparatus 1, the stopper shaft 45 is formed by a screw. Each stopper mechanism 5 is located on the lower surface 27a of the head holder 27 and has a nut 46 into which the stopper shaft 45 is screwed, and a stopper motor 41 that rotates the stopper shaft 45 to change its height position. This makes it possible to individually adjust the height position of each stopper shaft 45 steplessly.

[0075] In the embodiment described above, the displacement sensor 6 was configured to detect the distance to the abutment surface 17a. However, the displacement sensor 6 may also be configured to detect the distance to the transport surface 11a. In this case, the difference between the distance detected by the displacement sensor 6 and the theoretical distance from the displacement sensor 6 to the transport surface 11a can be used to calculate the correction value for the number of drive pulses of the abutment motor 41.

[0076] Furthermore, the displacement sensor 6 may be omitted. In this case, for example, when assembling the inkjet printing apparatus 1, the reference height position of the abutment shaft 45 of each abutment mechanism 5 is measured with high precision, and a correction value for the number of drive pulses of the abutment motor 41 of each abutment mechanism 5 is calculated based on the measurement results. Then, in the operation of adjusting the distance H between the head transport surfaces, when lowering the abutment shaft 45 from the reference height position in each abutment mechanism 5, the abutment motor 41 should be driven in the forward direction for a number of drive pulses equal to the theoretical value of the number of drive pulses required to lower the abutment shaft 45 to the target height position plus the correction value mentioned above.

[0077] Furthermore, the above-described embodiment shows a configuration comprising four abutment mechanisms 5. However, the number of abutment mechanisms is not limited to this, and the present invention is applicable to configurations in which the distance between the head transport surfaces is adjusted by the abutment axes of multiple abutment mechanisms.

[0078] The present invention is not limited to the embodiments described above, and the components can be modified and implemented in practice without departing from the spirit of the invention. Furthermore, various inventions can be formed by appropriately combining the multiple components disclosed in the embodiments. For example, some components may be deleted from all the components shown in the embodiments.

[0079] [Note] This application discloses the following invention:

[0080] (Note 1) Inkjet head and A transport unit is located below the inkjet head and transports the printing medium, Each of the abutment mechanisms has a stopper shaft whose lower end abuts against the conveying section, and the height position of each abutment shaft can be individually adjusted steplessly. An inkjet printing apparatus characterized by comprising the following features.

[0081] (Note 2) The head holder for holding the inkjet head is further comprising: The aforementioned abutment shaft is formed by a screw, Each of the aforementioned multiple abutment mechanisms is: A nut is positioned on the lower surface of the head holder, and the abutment shaft is screwed into it, A drive unit that rotates the abutment shaft to change the height position of the abutment shaft. The inkjet printing apparatus according to Appendix 1, further characterized by having the following: [Explanation of Symbols]

[0082] 1. Inkjet printing device 2. Conveying section 3 Printing Department 4. Lifting mechanism 5 Abutment mechanism part 6. Displacement Sensor 7 Control Unit 11. Conveyor belt 11a Conveying surface 12 drive rollers 13-15 Driven rollers 16 Platen 17 Plastic Templates 17a Immediately 18 Suction part 21 Chambers 22 Fans 26 inkjet heads 26a Nozzle surface 27 Head holder 31 wires 32 Winding mechanism section 41. Push-button motor 42 Warm 43 Intermediate gear 44 Charge Gear 45 Assault axis 46 nuts 47 Reference Blocks 48 Worm Wheel 49 Lower gear

Claims

1. Inkjet head and A transport unit is located below the inkjet head and transports the printing medium, Each of the abutment mechanisms has a stopper shaft whose lower end abuts against the conveying section, and the height position of each abutment shaft can be individually adjusted steplessly. An inkjet printing apparatus characterized by comprising the following features.

2. The head holder for holding the inkjet head is further comprising: The aforementioned abutment shaft is formed by a screw, Each of the aforementioned multiple abutment mechanisms is: A nut is positioned on the lower surface of the head holder, and the abutment shaft is screwed into it, A drive unit that rotates the abutment shaft to change the height position of the abutment shaft. The inkjet printing apparatus according to claim 1, further comprising the above.

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