Inkjet printing apparatus

Abstract

The invention provides an inkjet printing apparatus. An inkjet printing apparatus includes: an inkjet head; a transport unit which is disposed below the inkjet head and transports a printing medium; and a plurality of contact mechanism parts each having a contact shaft whose lower end is in contact with the conveyance part, the plurality of contact mechanism parts being capable of adjusting the height position of the contact shaft independently and steplessly.

Description

Technical Field

[0001] This invention relates to an inkjet printing apparatus. Background Technology

[0002] In inkjet printers, the smaller the distance between the printhead and the printing medium, i.e., the smaller the gap, the higher the ink landing accuracy, resulting in superior image performance. However, a smaller gap also increases the likelihood of the printing medium colliding with the printhead, thus reducing paper feeding performance.

[0003] On the other hand, the larger the gap between the paper heads, the better the paper feeding performance, but the image performance will be reduced because it is easy to cause a decrease in ink landing accuracy and contamination of the printed surface caused by ink mist.

[0004] Therefore, in order to balance image performance and paper feeding performance, the head gap needs to be adjusted to a size suitable for the type of printing media, print quality, and other printing settings.

[0005] Japanese Patent Application Publication No. 2020-82551 discloses an inkjet recording apparatus equipped with an adjustment mechanism that adjusts the distance between the transport unit and the head unit in multiple stages as a technology for adjusting the head gap. However, in this technology, because the adjustment is done in stages, it is sometimes impossible to adjust to an appropriate head gap.

[0006] Japanese Patent Application Publication No. 2021-142740 discloses a technology capable of steplessly adjusting the head gap. In this technology, an eccentric cam is fixed to one end and the other end of a guide shaft supporting a carriage on which the recording head is mounted. The height of the guide shaft can be steplessly adjusted by the rotation of the eccentric cam caused by the rotation of the guide shaft. Thus, the distance between the recording head and the medium supported by the support member, i.e., the head gap, can be steplessly adjusted. Summary of the Invention

[0007] In the technology disclosed in Japanese Patent Application Publication No. 2021-142740, two eccentric cams fixed at both ends of the guide shaft are synchronized. Therefore, in cases where the support member is tilted relative to the recording head due to deviations in the dimensional accuracy or assembly accuracy of the components, this tilt cannot be corrected.

[0008] Here, if the dimensional accuracy and assembly accuracy of the components are high, the tilting of the support member relative to the recording head, as described above, can be suppressed. However, due to insufficient dimensional accuracy and assembly accuracy of the components, tilting of the support member relative to the recording head sometimes occurs. In this case, as described above, the technology disclosed in Japanese Patent Application Publication No. 2021-142740 cannot correct this tilt, and as a result, it is sometimes impossible to adjust the head gap to an appropriate level throughout the entire printing range.

[0009] The purpose of this invention is to provide an inkjet printing apparatus capable of adjusting the head gap to an appropriate value throughout the entire printing range.

[0010] The inkjet printing apparatus of the present invention includes: an inkjet head; a transport section disposed below the inkjet head for transporting printing media; and a plurality of abutment mechanism sections, each having an abutment shaft whose lower end abuts against the transport section, and the height position of the abutment shaft being independently and steplessly adjustable.

[0011] Based on the above structure, the appropriate head gap can be adjusted throughout the entire printing range in the inkjet printing device. Attached Figure Description

[0012] Figure 1 This is a schematic structural diagram of the inkjet printing apparatus according to the embodiment.

[0013] Figure 2 yes Figure 1 The diagram shows the control block diagram of the inkjet printing device.

[0014] Figure 3 It means Figure 1 A perspective view of the schematic structure of the printing section of the inkjet printing device shown.

[0015] Figure 4 It means Figure 1 A perspective view of the schematic structure of the contact mechanism of the inkjet printing device shown.

[0016] Figure 5 A diagram used to illustrate the action of adjusting the distance between the conveyor surfaces.

[0017] Figure 6 This diagram illustrates an example where the abutment shaft of one abutment mechanism is positioned at a different height than the abutment shafts of other abutment mechanisms. Detailed Implementation

[0018] In the following detailed description, numerous specific details are set forth for purposes of explanation in order to provide a thorough understanding of the disclosed embodiments. However, it will be apparent, however, that one or more embodiments may be implemented without these specific details. In other instances, well-known structures and apparatuses are schematically illustrated for the purpose of simplifying the drawings.

[0019] Hereinafter, embodiments of the present invention will be described based on the accompanying drawings. It should be noted that identical or similar parts and components are indicated by identical or similar reference numerals in the drawings, and the descriptions of these parts and components are omitted or simplified. Furthermore, it should be noted that the drawings are schematic and therefore differ from actual conditions.

[0020] Figure 1This is a schematic structural diagram of an inkjet printing apparatus 1 according to an embodiment of the present invention. Figure 2 yes Figure 1 The control block diagram of the inkjet printing device 1 shown is shown. Figure 3 It means Figure 1 A perspective view of the schematic structure of the printing section 3 of the inkjet printing device 1 shown. Figure 4 It means Figure 1 This is a perspective view of the schematic structure of the contact mechanism 5 of the inkjet printing device 1. In the following description, it will be compared with... Figure 1 The direction orthogonal to the paper is defined as the front-back direction. Furthermore, [the following is omitted as it is not directly related to the previous sentence] Figure 1 The top, bottom, left, and right sides of the paper are set as the top, bottom, left, and right directions. Figure 1 , Figure 3 , Figure 4 In this context, RT, LT, UP, DN, FT, and RR represent the right direction, left direction, up direction, down direction, forward direction, and backward direction, respectively.

[0021] like Figure 1 , Figure 2 As shown, the inkjet printing device 1 includes a conveying unit 2, a printing unit 3, a lifting mechanism 4, four contacting mechanisms 5, four displacement sensors 6, and a control unit 7.

[0022] The conveying unit 2 conveys the printing medium, i.e., paper P, supplied from the paper supply unit (not shown). The conveying unit 2 is located below the printing unit 3. The conveying unit 2 includes a conveyor belt 11, a drive roller 12, driven rollers 13-15, a table 16, a table base plate 17, and a suction unit 18.

[0023] The conveyor belt 11 holds and transports the paper P fed from the paper feeding section. The conveyor belt 11 is an annular belt wrapped around the drive roller 12 and driven rollers 13-15. Multiple perforations (not shown) are formed in the conveyor belt 11, serving as through holes for air suction. The conveyor belt 11 utilizes the suction force generated in the perforations due to the drive of the fan 22 of the suction section 18 (described later) to hold the paper P on the conveyor surface 11a. The conveyor surface 11a is the surface of the conveyor belt 11 on which the paper P is placed; it is the upper surface of the planar portion of the conveyor belt 11 between the drive roller 12 and driven roller 13. The conveyor belt 11... Figure 1 The paper P, held in place, rotates clockwise (moves in a circular motion) to convey the paper P in a left-to-right conveying direction.

[0024] The drive roller 12 rotates the conveyor belt 11. The drive roller 12 is driven by a motor (not shown).

[0025] Driven rollers 13-15, together with drive roller 12, support the conveyor belt 11. Driven rollers 13-15 rotate in response to the conveyor belt 11. Driven roller 13 is positioned to the left of drive roller 12 at the same height as drive roller 12. Driven rollers 14 and 15 are positioned at the same height, separated from each other in the left-right direction, below drive roller 12 and driven roller 13.

[0026] The platform 16 is disposed between the drive roller 12 and the driven roller 13 on the underside of the conveyor belt 11, and is a plate-shaped component that supports the conveyor belt 11 into a slidable planar shape. The platform 16 is rectangular in shape when viewed from above. Multiple through holes are formed in the platform 16 for air to be drawn in by the fan 22.

[0027] The base plate 17 is disposed below the platform 16 and is a planar, plate-shaped component that supports the platform 16 by means of multiple spacers (not shown). The base plate 17 is rectangular in shape when viewed from above. Multiple through holes are formed in the base plate 17 for air drawn in by the fan 22 to pass through. The upper surface of the base plate 17 is an abutment surface 17a for the top (lower) end of the abutment shaft 45 of the abutment mechanism 5 (described later) to abut against. The base plate 17 is larger than the conveyor belt 11 and the platform 16 in the front-to-back direction.

[0028] The suction unit 18 draws air through the through holes in the base plate 17, the through holes in the plate 16, and the perforated area of ​​the conveyor belt 11, causing the paper P to adhere to the conveyor belt 11. The suction unit 18 includes a chamber 21 and a fan 22.

[0029] Chamber 21 forms a negative pressure chamber for generating suction force in the perforations of the conveyor belt 11. Chamber 21 is located on the back side of the base plate 17.

[0030] Fan 22 exhausts air from chamber 21. Thus, fan 22 draws air through the through holes in the base plate 17, the through holes in the plate 16, and the perforations in the conveyor belt 11, generating an adsorption force in the perforations, causing the paper P to adhere to the conveyor belt 11.

[0031] Printing unit 3 prints on the paper P conveyed by conveying unit 2. For example... Figure 1 , Figure 3 As shown, the printing unit 3 has multiple inkjet heads 26 and head holders 27.

[0032] The inkjet head 26 ejects ink onto the paper P. The inkjet head 26 has a plurality of nozzles (not shown) that open on its lower surface, i.e., nozzle surface 26a, opposite to the conveyor surface 11a of the conveyor belt 11, and ejects ink from the nozzles. In this embodiment, 18 inkjet heads 26 are provided in a staggered arrangement.

[0033] The head holder 27 holds the inkjet head 26. The head holder 27 holds the inkjet head 26 such that the lower end of the inkjet head 26 protrudes downward from the lower surface 27a of the head holder 27. The head holder 27 is rectangular in shape when viewed from above.

[0034] The lifting mechanism 4 raises and lowers the conveying unit 2. The lifting mechanism 4 includes a metal wire 31 and a winding mechanism 32.

[0035] The metal wire 31 suspends and supports the conveying part 2. The metal wire 31 passes through the through hole formed on the abutment shaft 45 of each abutment mechanism part 5, and its top (bottom) end is connected to the base plate 17 of the platform.

[0036] The winding mechanism 32 raises and lowers the conveying section 2 by winding and unwinding the metal wire 31.

[0037] The contact mechanism 5 defines the head-carrying surface distance H. The head-carrying surface distance H is the distance between the nozzle surface 26a of the inkjet head 26 and the conveying surface 11a of the conveyor belt 11. That is, the head-carrying surface distance H is obtained by adding the thickness of the paper P to the distance between the nozzle surface 26a and the paper P on the conveying surface 11a, i.e., the head gap.

[0038] like Figure 3 As shown, the abutment mechanism 5 has one at each of the four corners of the head retainer 27.

[0039] like Figure 4 As shown, the abutting mechanism 5 includes an abutting motor (drive unit) 41, a worm gear 42, an intermediate gear 43, an abutting gear 44, an abutting shaft 45, a nut 46, and a reference block 47.

[0040] The abutment motor 41 rotates the abutment shaft 45 via the worm gear 42, intermediate gear 43, and abutment gear 44, thereby changing the height position of the abutment shaft 45. The abutment shaft 45 is lowered by the forward rotation of the abutment motor 41, and raised by the reverse rotation of the abutment motor 41. The abutment motor 41 is, for example, a pulse motor.

[0041] The worm gear 42 transmits the driving force from the abutting motor 41 to the intermediate gear 43. The worm gear 42 is fixed to the output shaft of the abutting motor 41.

[0042] The intermediate gear 43 transmits the driving force of the abutting motor 41 from the worm 42 to the abutting gear 44. The intermediate gear 43 is composed of a double gear, including a worm wheel 48 that meshes with the worm 42 and a lower gear 49 that meshes with the spur gear 44.

[0043] The abutting gear 44 rotates together with the abutting shaft 45 under the driving force of the abutting motor 41 transmitted from the intermediate gear 43. The abutting gear 44 is integrally formed with the abutting shaft 45 in such a way that it surrounds the upper end of the abutting shaft 45. The abutting gear 44 is composed of a spur gear that meshes with the lower gear 49.

[0044] 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 base plate 17. The abutment shaft 45 is formed by a threaded part and is threadedly engaged with the nut 46. As a result, the height position of the abutment shaft 45, which rotates due to the drive of the abutment motor 41, changes. Therefore, 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.

[0045] The abutment shaft 45 has a through hole formed in its axial direction, through which the metal wire 31 passes.

[0046] The height position of the abutment shaft 45 of each abutment mechanism 5 can be adjusted independently and steplessly by driving each other with its respective 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 corresponding to one pulse of the drive pulse is so small that it can be considered to be able to adjust the height position of the abutment shaft 45 steplessly.

[0047] Nut 46 is used to change the height position of the rotating abutment shaft 45. Nut 46 is fixed to the lower surface 27a of the head retainer 27.

[0048] The reference block 47 defines the reference height position of the abutment shaft 45. The abutment shaft 45 stops by abutting the upper end of the abutment shaft 45 against the reference block 47, thereby positioning the abutment shaft 45 at the reference height position.

[0049] Displacement sensor 6 is disposed near the abutment mechanism 5 on the lower surface 27a of head holder 27 to detect the distance from displacement sensor 6 to the abutment surface 17a of platform base plate 17. One displacement sensor 6 is disposed near each of the four abutment mechanism parts 5.

[0050] The control unit 7 controls the operation of each part of the inkjet printing device 1. The control unit 7 is configured to include a CPU, RAM, ROM, hard disk, etc.

[0051] Next, refer to Figure 5 This describes the action of adjusting the distance H between the head conveyor surfaces in the inkjet printing unit 1.

[0052] Figure 5Part (a) indicates a state where the height position of the contact shaft 45 of each contact mechanism 5 is unclear when the inkjet printing device 1 is powered on. In this state, the transport section 2 is positioned below the lower end of the contact shaft 45.

[0053] from Figure 5 Starting from state (a), control unit 7 reverses the drive of the contact motors 41 of each contact mechanism unit 5, such as... Figure 5 As shown in part (b), the abutment shaft 45 is raised.

[0054] At this time, the control unit 7 reverses the drive of the contact motor 41 for a predetermined time. Thus, as... Figure 5 As shown in part (c), the abutment shaft 45 abuts against the reference block 47 or the abutment motor 41 loses synchronization, and the abutment shaft 45 stops at the reference height position.

[0055] Next, the control unit 7 drives the contact motors 41 of each contact mechanism unit 5 to rotate forward, such as... Figure 5 As shown in part (d), the abutment shaft 45 is lowered. At this time, the control unit 7 drives the abutment motor 41 to rotate forward by an amount corresponding to the number of drive pulses used to lower the abutment shaft 45 to the target height position. As a result, the abutment shaft 45 of each abutment mechanism unit 5 is lowered to the target height position.

[0056] Here, the target height position of the abutment shaft 45 is the height position where the distance H between the head conveyor surfaces becomes the target value. The drive pulse number mentioned above includes the correction value for the drive pulse number, which will be described later.

[0057] Next, the control unit 7 uses the lifting mechanism unit 4 to raise the conveying unit 2, causing the abutment shaft 45 to abut against the base plate 17. As a result, the distance H between the head conveying surfaces becomes the target value, and the adjustment of the distance H between the head conveying surfaces is completed.

[0058] Here, in the inkjet printing apparatus 1, as the printing mode, it is possible to select a paper feed performance priority mode and an image performance priority mode. The printing mode can be selected, for example, by using a user operation input unit (not shown).

[0059] Paper feed performance priority mode prioritizes paper feed performance over image performance. Paper feed performance refers to the difficulty of paper collisions with the inkjet head (26) causing feed defects. Image performance refers to print quality. A larger head gap improves paper feed performance, while a smaller head gap improves image performance.

[0060] The thicker the paper P, the smaller the head gap will be, even if the distance H between the head conveying surfaces is the same.

[0061] Therefore, the target value for the head feed surface distance H is set to a value corresponding to the paper type (paper thickness) and printing mode. Thus, in the inkjet printing apparatus 1, the head gap can be adjusted according to the paper type and printing mode.

[0062] Next, the correction value for the number of drive pulses of the aforementioned contact motor 41 will be explained.

[0063] In the inkjet printing apparatus 1, due to deviations in the dimensional accuracy and assembly accuracy of components such as the head holder 27, the transport section 2, and the contact mechanism section 5 that are related to the distance H between the head transport surfaces, there is a possibility that the reference height position of the contact shaft 45 of each contact mechanism section 5 may be deviated.

[0064] Therefore, even if the abutment shaft 45 is lowered by the same number of drive pulses corresponding to the target height position after it abuts against the reference block 47 in each abutment mechanism 5, there is still a possibility that the height position of the abutment shaft 45 may deviate from the target height position. Therefore, when the abutment shaft 45 of each abutment mechanism 5 abuts against the transport unit 2, there is a possibility that the transport surface 11a may tilt, making it impossible to adjust to an appropriate head gap throughout the entire printing range.

[0065] Therefore, in the inkjet printing device 1, a correction value for the number of drive pulses of the abutment motor 41 used to correct the height position of the abutment shaft 45 is calculated.

[0066] Specifically, for example, during the initial startup of the inkjet printing device 1, the control unit 7 from the aforementioned Figure 5 The state of part (a) causes the abutment shaft 45 of each abutment mechanism part 5 to be like Figure 5 As part (b) rises, and like Figure 5 Part (c) stops at the reference height position.

[0067] Next, the control unit 7 uses the lifting mechanism 4 to raise the conveying unit 2, so that the abutting shaft 45 abuts against the bottom plate 17 of the platform.

[0068] Next, the control unit 7 obtains the distance from each displacement sensor 6 to the contact surface 17a of the platform base plate 17 from each displacement sensor 6.

[0069] Next, the control unit 7 calculates the difference between the distance obtained from each displacement sensor 6 and the theoretical value of the distance from the displacement sensor 6 to the contact surface 17a when the platform base plate 17 is in contact with the contact shaft 45 positioned at the reference height position. This difference represents the offset of the reference height position of the contact shaft 45 from the theoretical value. The difference is positive when the reference height position of the contact shaft 45 is offset downwards relative to its designed position, and negative when the reference height position of the contact shaft 45 is offset upwards relative to its designed position.

[0070] Next, the control unit 7 calculates the number of drive pulses for each displacement sensor 6, which is used to move the abutment shaft 45 by the magnitude of the difference mentioned above corresponding to that displacement sensor 6.

[0071] Then, the control unit 7 calculates the value obtained by setting the calculated number of drive pulses to the opposite sign of the difference for each displacement sensor 6, and uses it as the correction value for the number of drive pulses of the abutment motor 41 of the abutment mechanism unit 5 near the displacement sensor 6.

[0072] The correction value of the number of drive pulses of the contact motor 41 of each contact mechanism 5 is calculated in the aforementioned operation of adjusting the distance H between the conveying surfaces of the head.

[0073] That is, when the abutment shaft 45 is lowered from the reference height position, the control unit 7 drives the abutment motor 41 to rotate forward by an amount corresponding to the number of drive pulses obtained by adding the aforementioned correction value to the theoretical value of the number of drive pulses used to lower the abutment shaft 45 to the target height position. Therefore, even if there is a deviation in the reference height position of the abutment shaft 45 of each abutment mechanism 5, the height position of the abutment shaft 45 of each abutment mechanism 5 can be aligned, and tilting of the transport surface 11a can be suppressed. As a result, an appropriate head gap can be adjusted throughout the entire printing range of the paper P.

[0074] In addition, in the inkjet printing device 1, it is sometimes desirable to arrange the contact shafts 45 of each contact mechanism 5 at independent height positions.

[0075] For example, due to errors in the height position of each inkjet head 26 mounted on the head holder 27, such as... Figure 6 As shown, the leftmost inkjet head 26 protrudes more from the head holder 27, resulting in an inclination in the height position of the plurality of inkjet heads 26 in the printing unit 3. In this case, if the transport surface 11a is horizontal, the transport surface 11a is tilted relative to the height direction of the plurality of inkjet heads 26 in the printing unit 3.

[0076] Therefore, in this situation, the control unit 7 adjusts the height position of the contact shaft 45 of each contact mechanism 5 so that the contact shaft 45 of the two left corner contact mechanism 5 is positioned lower than the contact shaft 45 of the two right corner contact mechanism 5, and the distance H between the head transport surfaces of each inkjet head 26 is approximately uniform. This allows correction of the tilt of the transport surface 11a relative to the plurality of inkjet heads 26 of the printing unit 3, thus enabling adjustment of the appropriate head gap throughout the entire printing range of the paper P.

[0077] As described above, the inkjet printing apparatus 1 includes four contact mechanism sections 5, each having a contact shaft 45 whose lower end abuts against the transport section 2. The height position of the contact shaft 45 can be adjusted independently and steplessly. Because the height position of the contact shaft 45 can be adjusted steplessly, the head transport surface distance H can also be adjusted steplessly. Since the height positions of the contact shafts 45 of the four contact mechanism sections 5 can be adjusted independently, even in cases where there are deviations in the dimensional accuracy or assembly accuracy of components related to the head transport surface distance H, tilting of the transport surface 11a can be suppressed. It is also possible to accommodate situations where the contact shafts 45 of each contact mechanism section 5 are positioned at independent heights. Therefore, according to the inkjet printing apparatus 1, an appropriate head gap can be adjusted throughout the entire printing range of the paper P.

[0078] In the inkjet printing apparatus 1, the abutment shaft 45 is formed by a threaded component. Each abutment mechanism 5 includes: a nut 46 disposed on the lower surface 27a of the head retainer 27, to which the abutment shaft 45 is threadedly engaged; and an abutment motor 41 that rotates the abutment shaft 45 to change its height position. Thus, the height position of each abutment shaft 45 can be adjusted independently and steplessly.

[0079] Furthermore, in the above embodiment, the displacement sensor 6 detects the distance up to the contact surface 17a. However, the displacement sensor 6 can also detect the distance up to the conveying surface 11a. In this case, the correction value for the number of drive pulses of the contact motor 41 can be calculated using the difference between the distance detected by the displacement sensor 6 and the theoretical value of the distance from the displacement sensor 6 to the conveying surface 11a.

[0080] Alternatively, the displacement sensor 6 can be omitted. In this case, for example, when assembling the inkjet printing device 1, the reference height position of the contact shaft 45 of each contact mechanism 5 is measured with high precision, and a correction value for the number of drive pulses of the contact motor 41 of each contact mechanism 5 is calculated based on the measurement result. Furthermore, during the operation of adjusting the distance H between the head conveyor surfaces, when the contact shaft 45 in each contact mechanism 5 is lowered from the reference height position, it is sufficient to drive the contact motor 41 in a forward direction by an amount corresponding to the number of drive pulses obtained by adding the aforementioned correction value to the theoretical value of the number of drive pulses used to lower the contact shaft 45 to the target height position.

[0081] Furthermore, the above embodiment shows a structure with four abutment mechanism sections 5. However, the number of abutment mechanism sections is not limited to this; any structure that uses the abutment shafts 45 of multiple abutment mechanism sections 5 to adjust the distance between the head conveying surfaces is acceptable.

[0082] The embodiments of this disclosure have, for example, the following structure.

[0083] The inkjet printing device includes: an inkjet head; a transport section disposed below the inkjet head for transporting printing media; and a plurality of abutment mechanisms, each having an abutment shaft whose lower end abuts against the transport section, and the height position of the abutment shaft can be adjusted independently and steplessly.

[0084] The inkjet printing apparatus described above may also include a head holder for holding the inkjet head. The abutment shaft may also be formed by a threaded component. The plurality of abutment mechanism parts may each include: a nut disposed on the lower surface of the head holder and threadedly engaged with the abutment shaft; and a drive unit that rotates the abutment shaft to change the height position of the abutment shaft.

[0085] The embodiments of the present invention have been described above. However, the present invention may be implemented in other specific ways without departing from the technical spirit or essential characteristics of the invention. Therefore, the embodiments of the present invention are to be considered illustrative rather than restrictive in all respects, and the scope of the invention is indicated by the appended claims rather than by the foregoing description; thus, all changes falling within the equivalent meaning and scope of the claims are intended to be included therein.

[0086] Furthermore, the effects described in the embodiments of the present invention are merely examples of the best effects achieved by the present invention. Therefore, the effects of the present invention are not limited to those described in the embodiments of the present invention.

Claims

1. An inkjet printing apparatus, wherein the inkjet printing apparatus includes: an inkjet head; a conveyance section configured below the inkjet head to convey a print medium; and a plurality of abutting mechanism sections each having an abutting shaft that abuts the conveyance section at a lower end, the plurality of abutting mechanism sections being capable of adjusting a height position of the abutting shaft independently of each other and steplessly.

2. The inkjet printing apparatus according to claim 1, wherein the inkjet printing apparatus further includes a head holder that holds the inkjet head, the abutting shaft includes a threaded member, the plurality of abutting mechanism sections each include: a nut configured to a lower surface of the head holder to threadedly engage with the abutting shaft; and a drive section that rotates the abutting shaft to change the height position of the abutting shaft.

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