WO2017109833A1

WO2017109833A1 - Ink jet head assembly

Info

Publication number: WO2017109833A1
Application number: PCT/JP2015/085692
Authority: WO
Inventors: 郁夫武田; 平田　幸司
Original assignee: 富士通周辺機株式会社
Priority date: 2015-12-21
Filing date: 2015-12-21
Publication date: 2017-06-29
Also published as: JPWO2017109833A1; JP6509375B2

Abstract

Provided is an ink jet head assembly (2A) comprising a plurality of ink jet heads (20) disposed on a base plate (21) facing a printing medium, arranged in the width direction of the printing medium such that printing areas do not overlap, the ink jet assembly (2A) being configured such that: each ink jet head (20) is fixed to frames (22) using an alignment plate (23); each frame (22) is movably mounted onto the base plate (21) in the width direction of the printing medium; an eccentric pin (50) including a first pin having a rotation axis on the base plate (21) and a second pin (52) which comprises an axis offset from said rotation axis and protrudes above the first pin is provided between the base plate (21) and each frame (22); and the tip section of the second pin (52) is fitted into an elongated hole (44) provided in the frames (22), and when the eccentric pin (50) is rotated from the outside, the tip section of the second pin (52) pushes a flat wall of the elongated hole (44) and moves the frame (22) to adjust the distance from an adjacent ink head.

Description

Inkjet head assembly

This application relates to an inkjet head assembly.

Conventionally, ink jet printer apparatuses such as ink jet printers and ink jet plotters using an ink jet recording method are known. The ink jet recording method prints on a recording medium by ejecting ink, which has been formed into fine droplets, from a nozzle hole of a head toward a recording medium such as paper. Inkjet printers are also required to increase the printing speed, but the printing speed is slow in the method of printing by scanning the inkjet head in the width direction of the recording medium. Therefore, instead of the scanning ink jet head, one fixed ink jet head in which a plurality of nozzle holes are arranged in the width direction of the recording medium is used, and lines in the width direction of the recording medium are simultaneously printed to increase the printing speed. Inkjet printer devices. For example, an ink jet printer apparatus that performs printing on a continuous printing paper as a recording medium using a fixed ink jet head has been put into practical use as a line printer apparatus.

However, in the line printer apparatus, if only one inkjet head corresponding to the entire width of the printing paper is manufactured, the manufacturing cost increases. Therefore, the inkjet head is manufactured in several parts and combined to form an inkjet head assembly. ing. Specifically, the printing paper is divided into a plurality of areas in the width direction, and a small inkjet head is prepared for each divided area to share printing. The ink-jet head assembly is formed by arranging a plurality of ink-jet heads, for example, in a staggered manner in two rows on a frame at a position facing the printing paper. In the case of an ink jet head assembly having this structure, if the alignment of a plurality of ink jet heads is not performed accurately, the position and direction of ink discharge between the ink jet heads may change, resulting in problems such as streaks on the printed matter. there were.

Therefore, Patent Document 1 proposes an inkjet head assembly and an inkjet head manufacturing method that can be assembled with high positional accuracy in a short time and can suppress deterioration of printing accuracy caused by changes in environmental temperature. . The ink jet head assembly disclosed in Patent Document 1 includes an ink jet head, a flat frame, two positioning pins protruding from the main surface of the frame, and a screw for fixing the ink jet head to the frame.

The ink-jet head has a nozzle surface in which a plurality of nozzle holes for ink ejection are formed in a rectangular nozzle formation region. The ink-jet head is a flat frame, and the nozzle surface is parallel to the main surface of the frame. To be fixed. At this time, two positioning pins provided perpendicularly to the main surface of the frame are in contact with the inkjet head outside the short side of the nozzle formation region. One positioning pin determines the center of rotation of the inkjet head in a plane parallel to the main surface of the frame, and the other positioning pin stops the rotation of the inkjet head for positioning. The inkjet head is screwed to the frame in contact with two positioning pins on the outer side of the short side of the nozzle formation region.

JP 2008-296518 A

However, although the structure disclosed in Patent Document 1 is excellent in the reproducibility of the mounting positions of individual inkjet heads, it is impossible to adjust the position between a plurality of inkjet heads that are individually fixed on the frame, and the print area There was a problem that the seam adjustment was difficult.

In one aspect, the present application provides an inkjet head assembly that can easily adjust a position between a plurality of inkjet heads fixed on a frame, and can easily adjust a seam of a print area by each inkjet head. For the purpose of provision.

According to one form, it is an inkjet head assembly provided with the some inkjet head arrange | positioned for every printing area | region in the width direction of a printing medium on the base plate facing a printing medium, Comprising: 1 of several inkjet heads A frame that is fixed to the base plate and attached to a mounting portion on the base plate, and a micro-movement mechanism that is provided between each of the frames and the base plate and that is displaced by the application of external force to move the frame with respect to the base plate. An ink jet head assembly is provided in which the attachment portion is formed so that the frame can be moved in the direction of the adjacent attachment portion when the minute movement mechanism is displaced to slightly move the frame.

According to the disclosed inkjet head assembly, a plurality of inkjet heads are each fixed on the base plate via a frame, and the frame can be finely adjusted on the base plate in the width direction of the print medium by a fine movement mechanism. There is an effect that the joint of the printing area of the adjacent inkjet head can be easily adjusted.

FIG. 1 is a perspective view illustrating the structure of a printer for continuous paper on which a printing apparatus having an inkjet head assembly of the present application is mounted. FIG. 2 is an explanatory diagram illustrating a continuous sheet conveyance path in the printer illustrated in FIG. 1 and the position of the inkjet head assembly in the conveyance path. FIG. 3 is a perspective view showing an entire printing apparatus including the inkjet head assembly of the embodiment of the printer shown in FIG. FIG. 4 is a perspective view showing the inkjet head assembly taken out from the printing apparatus shown in FIG. FIG. 5 is a plan view and a partially enlarged plan view of the inkjet head assembly shown in FIG. FIG. 6 is an explanatory diagram for explaining the tolerance of each member in the disclosed inkjet head assembly. FIG. 7A is an explanatory diagram showing the ejection positions of ink from the nozzle holes of each head when the head arrangement is ideal in the inkjet head assembly. FIG. 7B is an explanatory diagram showing the ejection position of ink from the nozzle holes of each head when the head arrangement is defective in the inkjet head assembly. FIG. 8A is a perspective view showing a structure of a base plate in the disclosed inkjet head assembly. FIG. 8B is a plan view of the base plate shown in FIG. 8A. FIG. 8C is a partially enlarged plan view of the base plate shown in FIG. 8B. FIG. 8D is a partially enlarged perspective view of the base plate shown in FIG. 8A. FIG. 9A is a perspective view showing a structure of a frame in the disclosed inkjet head assembly. FIG. 9B is a partially enlarged perspective view showing a state in which one end of the frame shown in FIG. 9A is viewed from the lower surface side. 10A is an exploded plan view showing a process of attaching one inkjet head to the frame shown in FIG. 9A. FIG. 10B is a plan view of a state where the inkjet head shown in FIG. 10A is attached to a frame. FIG. 11A is a perspective view showing the structure of an eccentric pin of a first example of a micro movement mechanism for moving a frame relative to a base plate in the disclosed inkjet head assembly. FIG. 11B is a schematic plan view of the eccentric pin shown in FIG. 11A. FIG. 11C is a perspective view of the eccentric pin shown in FIG. 11B. FIG. 11D is a schematic plan view showing a movement locus of the second pin when the first pin half-rotates in the eccentric pin shown in FIG. 11B. FIG. 12A is a partial assembly perspective view showing a process of attaching the eccentric pin shown in FIG. 11A to the base plate in the disclosed inkjet head assembly. 12B is a partial assembly perspective view showing a process of attaching a frame on which the inkjet head is mounted to the base plate shown in FIG. 12A to which an eccentric pin is attached. FIG. 13 is a partial assembly perspective view showing the same state as FIG. 12B, showing a step of attaching a frame on which the inkjet head is mounted to the base plate shown in FIG. 12A to which an eccentric pin is attached. FIG. 14A is a partial perspective view of the inkjet head assembly showing a state in which the frame on which the inkjet head is mounted is attached to the base plate. 14B is a cross-sectional view taken along the line GG of the ink jet head assembly shown in FIG. 14A. FIG. 15A is a schematic plan view showing the position of the frame when the eccentric pin is in the first position in the disclosed inkjet head assembly. FIG. 15B is a schematic plan view illustrating the position of the frame when the eccentric pin is rotated from the first position to the second position in the disclosed inkjet head assembly. FIG. 15C is a schematic plan view showing the position of the frame when the eccentric pin is rotated and moved from the second position to the third position in the disclosed inkjet head assembly. FIG. 16A is a perspective view showing a structure of an eccentric pin and a drive gear of a second embodiment of a minute movement mechanism for moving a frame relative to a base plate in the disclosed inkjet head assembly. FIG. 16B is a partial plan view showing the first embodiment of the arrangement of the drive gears with respect to the eccentric pin shown in FIG. 16A. FIG. 16C is a partial plan view showing a second embodiment of the arrangement of the drive gears with respect to the eccentric pin shown in FIG. 16A. 16D is a cross-sectional view taken along the line KK of the inkjet head assembly shown in FIG. 16B. FIG. 17A is a partial perspective view showing a structure of a third embodiment of a minute movement mechanism for moving a frame relative to a base plate in the disclosed inkjet head assembly. FIG. 17B is a cross-sectional view taken along the line HH of the inkjet head assembly shown in FIG. 17A. FIG. 18A is a plan view showing a jig used in the micro movement mechanism of the third embodiment shown in FIG. 17A. FIG. 18B is a partial plan view of a state in which the jig shown in FIG. 18A is attached to the micro movement mechanism shown in FIG. 16A. FIG. 18C is a partial plan view for explaining the operation of moving the frame using the jig shown in FIG. 18B.

Hereinafter, embodiments of an inkjet head assembly according to the present application will be described in detail based on specific examples with reference to the accompanying drawings. Here, a line printer that performs printing on continuous paper will be described as an example of a printing apparatus equipped with an inkjet head assembly, but the printing apparatus that can be equipped with the inkjet head assembly according to the present application is limited to a line printer. Is not to be done. Examples of other printing apparatuses on which the inkjet head assembly according to the present application can be mounted include inkjet plotters, electronic circuit forming apparatuses, color filter manufacturing apparatuses for liquid crystal displays, and organic EL display manufacturing apparatuses.

FIG. 1 is a perspective view for explaining the structure of a printer PT for continuous paper on which an inkjet head assembly can be mounted. FIG. 1 shows a conveyance path R of the continuous paper P in the printer PT with the front door 6 and the cover 7 provided in the main body 5 of the printer PT opened. A main body 5 of the printer PT includes a paper feeding unit 1, a printing device 2 having an inkjet head assembly, a brush 3, and a paper discharge unit 4. The continuous paper bundle PP folded and stacked is placed on the floor below the paper feeding unit 1, and the continuous paper P drawn from the continuous paper bundle PP while being unfolded is supplied to the paper feeding unit 1. The continuous paper P is sent to the printing apparatus 2 by the tractor in the paper feeding unit 1, and the continuous paper P after printing is folded again at the final stage of the transport path R and stacked on the paper discharge unit 4. The paper discharge unit 4 can be moved up and down with respect to the main body 5, and the paper discharge unit 4 descends when the amount of continuous paper P to be stacked increases.

FIG. 2 shows the transport path R of the continuous paper P in the printer PT shown in FIG. 1 and the position of the ink jet head assembly 2A of the printing apparatus 2 in the transport path R. The continuous paper P is provided with perforations at predetermined intervals in the width direction (direction perpendicular to the direction in which the paper continues), and the continuous paper P before use is folded and stacked at the perforations. A bundle PP of continuous sheets is placed on the side of the printer. Further, on both sides of the continuous paper P, feed holes (sprocket holes) for transporting the continuous paper P by the tractor 10 are opened at equal intervals.

The housing (not shown) of the tractor 10 is provided with drive wheels 11 and driven wheels 12 driven by a built-in motor, and a belt 13 is stretched between the drive wheels 11 and the driven wheels 12. Then, pins inserted into the feed holes of the continuous paper P are attached to the belt 13 at the same intervals as the feed holes of the continuous paper P. Since the feed holes for the continuous paper P are provided on both sides of the continuous paper P, two sets of the tractors 10 are provided in accordance with the positions of the feed holes for the continuous paper P. An arrow M indicates the direction of rotation of the motor of the drive wheel 11, and the continuous paper P is automatically conveyed by the tractor 10 if a pin is inserted into the feed hole. The tractor 10 is provided with a lid member 15 that prevents the continuous paper P from being detached from the tractor 10 when the continuous paper P is conveyed.

The continuous paper P drawn by the tractor 10 from the continuous paper bundle PP is first removed by the brush 3 of paper dust adhering to the periphery of the feed holes (dust generated when forming the feed holes in the continuous paper). The continuous paper P that has passed through the tractor 10 passes under the inkjet head assembly 2 A of the printing apparatus 2. The inkjet head assembly 2 A includes a plurality of inkjet heads 20, and the continuous paper P is printed (printed) with ink ejected from the inkjet head 20.

In the conventional line printer, the printing apparatus 2 has one large line head provided along the width direction of the continuous paper P. However, the disclosed printer PT has a print area on the continuous paper P. There are a plurality of inkjet heads 20 that perform printing in a shared manner. For example, five inkjet heads 20 are divided into three and two, and the plurality of inkjet heads 20 are arranged in two rows in a staggered manner. Further, a plurality of rollers 8 are provided in the conveyance path R of the continuous paper P in order to determine the movement path R of the continuous paper P, and the continuous paper P printed by the inkjet head assembly 2A is provided with the plurality of rollers 8. Is sent to the paper discharge unit 4 through the transport path R.

FIG. 3 is a perspective view showing the entire printing apparatus 2 including the inkjet head assembly 2A of the embodiment of the printer PT shown in FIG. A base plate 21 is provided on the housing 2B of the ink jet head assembly 2A of the present embodiment, and five ink jet heads 20 are mounted on the base plate 21. Since each inkjet head 20 has an attachment portion to the base plate 21, the five inkjet heads 20 cannot be arranged in a straight line. Therefore, in this embodiment, the five inkjet heads 20 are arranged in two rows in a staggered manner.

4 is a perspective view showing the inkjet head assembly 2A taken out from the casing 2B of the printing apparatus 2 shown in FIG. 3, and FIG. 5 is a plan view and a partially enlarged view of the inkjet head assembly 2A shown in FIG. It is a top view. The inkjet head assembly 2 A has a single base plate 21, and attachment portions 30 of the inkjet head 20 are provided in two rows in the longitudinal direction of the base plate 21 at five locations on the base plate 21. . The inkjet head 20 is not directly attached to the attachment portion 30, and is attached via a frame 22 as an adjustment plate. Ink jet heads 20 are fixed to the frames 22 using alignment plates 23, respectively.

Alignment plates 23 are provided at both ends of the inkjet head 20 in the longitudinal direction. One alignment plate 23 is provided with a V-shaped groove 24, and the other alignment plate 23 is provided with a protruding piece 25 having a side parallel to the longitudinal direction of the inkjet head 20. Further, two positioning pins 26 for determining the position of the inkjet head 20 on the frame 22 are fixed to the frame 22 as reference pins. The inkjet head 20 is positioned on the frame 22 in a state where the V-shaped groove 24 and the protruding piece 25 are in contact with the two positioning pins 26, respectively, and then fixed to the frame 22 with screws.

The positioning of the inkjet head 20 on the frame 22 by the V-shaped groove 24 and the protruding piece 25 on the alignment plate 23 of the inkjet head 20 and the two positioning pins 26 on the frame 22 is performed as follows. Done. First, a V-shaped groove 24 provided on one alignment plate 23 is brought into contact with one positioning pin 26. Next, the other end of the inkjet head 20 is rotated in the direction of the other positioning pin 26 with the positioning pin 26 as a rotation center. Then, the inkjet head 20 is fixed to the frame 22 with screws in a state where the protruding piece 25 provided on the other alignment plate 23 is in contact with the other positioning pin 26. By such a process, the inkjet head 20 is correctly positioned with respect to the frame 22, and the position of the inkjet head 20 with respect to the frame 22 is always constant.

The frame 22 to which the inkjet head 20 is fixed is fitted into the attachment portions 30 provided on the base plate 21 at five locations, and fixed with screws. The attachment portion 30 of the frame 22 is formed longer than the entire length of the frame 22 in the longitudinal direction of the base plate 21, and if the screws are loosened, the frame 22 is attached to the base plate 21 inside the attachment portion 30. It can be moved slightly in the longitudinal direction. The moving direction of the frame 22 is regulated by two positioning pins 26 fixed to the frame 22 and grooves provided in the base plate 21. This structure will also be described later.

FIG. 6 is an explanatory diagram for explaining the tolerance of each member in a state where an inkjet head (not shown) is attached to the frame 22 of the disclosed inkjet head assembly 2A. This figure shows a frame 22 attached to a base plate (not shown) and a plurality of nozzle holes 20N for ink ejection in the ink jet head as viewed from the upper side of the printing paper surface. In the drawing, the alignment plate is drawn integrally with the frame 22.

As shown in FIG. 6, in the disclosed inkjet head assembly 2 A, the processing accuracy of the positioning pin 26 that is fixed to the frame 22 and abuts on the V-shaped groove 24 of the alignment plate 23 and the positioning pin 26 adjacent thereto. C is ± 0.03 mm. The positioning pin 26 may be referred to as a reference pin 26. Further, the tolerance A from the reference pin 26 to the leftmost nozzle hole 20N is ± 0.005 mm, and the tolerance B of the entire width of the nozzle hole 20N in one inkjet head is ± 0.01 mm. Further, the tolerance E (tolerance E at the joint of the printing area) of the distance between the adjacent nozzle holes 20N between the adjacent inkjet heads is ± 0.05 mm.

FIG. 7A shows ink ejection positions SP from the nozzles 20N of the inkjet heads 20-1 to 20-5 when the arrangement of the five inkjet heads 20-1 to 20-5 is ideal in the inkjet head assembly 2A. It is explanatory drawing which shows. The arrow indicates the running direction of continuous paper. When the arrangement of the five inkjet heads 20-1 to 20-5 is ideal, all the distances between the adjacent nozzle holes 20N between the adjacent inkjet heads 20 are appropriate. However, even if the position of the inkjet head 20 with respect to the frame 22 is always constant, the arrangement of the five inkjet heads 20-1 to 20-5 attached to the base plate 21 is not always ideal.

FIG. 7B shows ink ejection positions SP from the nozzles 20N of the inkjet heads 20-1 to 20-5 when the arrangement of the five inkjet heads 20-1 to 20-5 is defective in the inkjet head assembly 2A. It is explanatory drawing shown. The arrow indicates the running direction of continuous paper. When the arrangement of the inkjet head is poor, the gap between the nozzle 20N closest to the inkjet head 20-1 and the inkjet head 20-5 may be narrowed. Conversely, if the arrangement of the inkjet head is poor, the gap between the inkjet head 20-3 and the nearest nozzle 20N of the inkjet head 20-4 may be widened.

Here, the structure of the individual members and the connection of the individual members in the ink jet head assembly 2A disclosed in FIGS. 4 and 5 will be described. First, the structure of the base plate 21 will be described with reference to FIGS. 8A to 8D. FIG. 8A is a perspective view showing the structure of the base plate 21 alone, and FIG. 8B is a plan view of the base plate 21 shown in FIG. 8A. 8C is a partially enlarged plan view of the base plate 21 shown in FIG. 8B, and FIG. 8D is a partially enlarged perspective view of the base plate 21 shown in FIG. 8A.

The base plate 21 has a rectangular shape with a predetermined thickness, and five inkjet head mounting portions 30 are arranged in two rows in the longitudinal direction. The attachment portions 30 are arranged at three locations on the upstream side (front row side) in the continuous sheet flow direction, and are arranged at two locations on the downstream side (rear row side). The attachment portions 30 are arranged in two rows in a staggered manner so that the inkjet heads do not collide with each other. A central portion of the attachment portion 30 is an opening portion 31 for passing ink ejected from the nozzle surface of the inkjet head. Further, in order to attach the end of the frame attached to the attachment part 30, a concave part 32 that is convex in plan view and a rectangular concave part 33 are formed at both ends of the opening 31. Further, there is no wall between the convex concave portion 32 and the rectangular concave portion 33 of the adjacent mounting portion 30 without any wall.

The convex portion 32P of the convex concave portion 32 is provided with a holding hole 34 into which a first pin portion of an eccentric pin described later is inserted and rotatably held. Further, in the rectangular portion 32R adjacent to the convex portion 32P, a guide groove 35 that guides the lower end portion of one of the positioning pins attached to the frame and protruding from the bottom surface of the frame by sliding in the longitudinal direction of the base plate 21. Is provided. Note that escape grooves 36 are provided on both sides of the guide groove 35 for receiving projections protruding from the lower surface of the frame, which will be described later. However, the escape grooves 36 have no functionality.

Similarly, the rectangular recess 33 is also provided with a guide groove 35 that guides the other lower end portion of the positioning pin attached to the frame and protruding from the bottom surface of the frame by sliding in the longitudinal direction of the base plate 21. Yes. Also in the rectangular recess 33, relief grooves 36 having no functionality are provided on both sides of the guide groove 35 so as to receive protrusions protruding from the lower surface of the frame, which will be described later.

Subsequently, the structure of the frame 22 as an adjustment plate mounted on the mounting portion 30 provided on the base plate 21 will be described with reference to FIGS. 9A and 9B. 9A is a perspective view of the frame 22 as viewed from the upper surface side, and FIG. 9B is a partially enlarged perspective view of one end portion of the frame 22 illustrated in FIG. 9A as viewed from the lower surface side. The frame 22 includes a frame body 40 having an outer dimension smaller than the inner dimension of the mounting portion 30 of the base plate 21 described with reference to FIGS. 8A to 8D, and a bottom surface of the inkjet head at the center of the frame body 40. There is an opening 41 through which ink ejected from the air passes. The frame 22 is made of metal.

One end of the frame body 40 in the longitudinal direction is provided with a convex flat plate portion 42 placed on the convex concave portion 32 of the base plate 21, and the other end is a rectangular concave portion of the base plate 21. A rectangular flat plate portion 43 placed on 33 is provided. A long hole 44 through which an eccentric pin, which will be described later, is inserted is provided in the convex portion 42P of the convex flat plate portion 42. The rectangular portion 42R adjacent to the convex portion 42P is provided with a positioning pin mounting hole 45 for mounting one of the positioning pins and a mounting screw mounting hole 49H described later. Similarly, in the rectangular flat plate portion 43 placed in the rectangular concave portion 33, a positioning pin mounting hole 45 for mounting the other positioning pin is provided.

And, on both sides of the mounting hole 45 of the positioning pin on the lower surface of the convex flat plate portion 42, projections 46 for improving the hot water flow of the mold for manufacturing the frame 22 are provided. The protrusion 46 enters the escape groove 36 in the base plate 22 described with reference to FIG. 8D, but has no functionality and is not directly related to the present application. Although there are protrusions on both sides of the positioning pin mounting hole 45 on the lower surface of the rectangular flat plate portion 43, the illustration and description thereof are omitted. Further, around the opening 41 inside the frame body 40, the stepped portion 47 on which the bottom surface of the inkjet head 20 attached to the opening 41 is placed and the stepped portion 47 are placed. A plurality of ribs 48 that regulate the side surface position of the base portion 20B of the inkjet head 20 are provided.

FIG. 10A is an exploded plan view showing a process of attaching one inkjet head 20 to the frame 22 shown in FIG. 9A. An alignment plate 23 having a V-shaped groove 24 and an alignment plate 23 having a protruding piece 25 are attached to the upper surface of the base 20B of the inkjet head 20 with screws 27 at both ends in the longitudinal direction of the inkjet head 20. Yes. The screw 27 may be another attachment such as a bolt or a nut. Further, the screw 28 between the screw 27 and the screw 27 is attached to the attachment hole 28 H in the frame body 40 of the frame 22 when the base portion 20 B of the inkjet head 20 is placed on the frame body 40 of the frame 22. The thickness of the base portion 20 B of the inkjet head 20 is equal to the depth of the stepped portion 47 from the upper surface of the frame body 40 of the frame 22.

Therefore, when the base portion 20B of the ink jet head 20 is placed on the step portion 47 of the frame body 40 of the frame 22, the upper surface of the base portion 20B of the ink jet head 20 is rectangular with the convex flat plate portions 42 at both ends of the frame body 40. It becomes the same height as the upper surface of the flat plate portion 43 having a shape. For this reason, when the base portion 20B of the inkjet head 20 is placed on the step portion 47 of the frame body 40 of the frame 22, the alignment plate 23 including the V-shaped groove 24 is placed on the upper surface of the convex flat plate portion 42. The alignment plate 23 including the protruding piece 25 is placed on the upper surface of the rectangular flat plate portion 43.

On the other hand, before the base portion 20B of the inkjet head 20 is placed on the frame body 40 of the frame 22, the positioning pins 26 are respectively attached to the mounting holes 45 of the two positioning pins. The upper end portion of the positioning pin 26 attached to the positioning pin attachment hole 45 protrudes from the upper surface of the convex flat plate portion 42 and the upper surface of the rectangular flat plate portion 43, and the protruding height is the thickness of the alignment plate 23. This should be done. Further, the lower end portion of the positioning pin 26 attached to the mounting hole 45 of the positioning pin protrudes from the lower surface of the convex flat plate portion 42 and the lower surface of the rectangular flat plate portion 43, and the protruding height is at the base plate 21. It is below the depth of a certain guide groove 35. A state in which the lower end portion of the positioning pin 26 attached to the positioning pin attachment hole 45 protrudes from the lower surface of the convex flat plate portion 42 and the lower surface of the rectangular flat plate portion 43 is shown in FIG. Yes.

The attachment of the inkjet head 20 to the frame 22 has been described above. More specifically, first, the positioning of the V-shaped groove 24 in the alignment plate 23 projecting from the convex flat plate portion 42 of the frame body 40 is performed. It abuts on the pin 26. Next, the base 20B of the inkjet head 20 is rotated around the positioning pin 26. When the base 20B reaches the position of the opening 41, the base 20 is inserted into the opening 41 and placed on the stepped portion 47. If the protruding piece 25 of the alignment plate 23 on the opposite side is in contact with the positioning pin 26 in this state, the base portion 20B is fixed to the frame 22. If there is a gap between the protruding piece 25 and the positioning pin 26, the base 20B is rotated around the positioning pin 26, the protruding piece 25 is brought into contact with the positioning pin 26, and the base 20B is fixed to the frame 22. . When the base portion 20B of the ink jet head 20 is fixed to the frame body 40, it becomes as shown in FIG. 10B.

Here, the eccentric pin 50, which is one of the minute movement mechanisms mounted between the base plate 21 and the frame 22, will be described with reference to FIGS. 11A to 11D. FIG. 11A is a perspective view showing the structure of the eccentric pin 50 of the first embodiment of the micro-movement mechanism for moving the frame 22 relative to the base plate 21 in the disclosed inkjet head assembly. 11B is a schematic plan view showing the relationship of the central axis of the eccentric pin 50 shown in FIG. 11A, and FIG. 11C is a perspective view of the eccentric pin 50 shown in FIG. 11B. Further, FIG. 11D is a schematic plan view showing a movement locus of the second pin 52 when the first pin 51 is half-rotated in the eccentric pin 50 shown in FIG. 11B.

The eccentric pin 50 is a cylindrical first pin 51 that is rotatably held in a holding hole 34 (see FIG. 8A) provided on the base plate, and a first pin 51 that protrudes from the first pin 51. Two pins 52 are formed. The tip of the second pin 52 is provided with a slit-like recess 53 having a predetermined depth into which the tip of the minus driver can be inserted. A mark 54 indicating the rotational position of the second pin 52 is attached to one side of the slit-like recess 53 on the top surface of the tip of the second pin 52. The slit-like recess 53 may be a cross-shaped recess for a plus driver.

11B and 11C, in the eccentric pin 50, the center axis AX2 of the second pin 52 is shifted by a predetermined distance X with respect to the center axis AX1 of the first pin 51. Therefore, when the first pin 51 rotates in the direction of the arrow T as shown in FIG. 11D from the state shown in FIG. 11B, the central axis AX2 of the second pin 52 moves on the circle C1, The mark 54 attached to the top surface of the pin 52 moves on the circle C2. When the first pin 51 rotates 180 degrees (half rotation) in the direction of the arrow T as shown in FIG. 11D, the second pin 52 moves away from the position before the first pin 51 rotates by the distance Y (first The center axis AX1 of the first pin 51 and the center axis AX2 of the second pin 52 are moved twice). When the first pin 51 is further rotated, the distance of the second pin 52 from the position before the first pin 51 rotates becomes smaller than the distance Y.

Since the first pin 51 only rotates around the rotation axis (center axis AX1) on the base plate 21, the position of the first pin 51 relative to the base plate 21 due to the rotation is unchanged. On the other hand, the second pin 52 protruding on the first pin 51 with the center axis AX2 deviating from the center axis AX1 of the first pin 51 is the first pin 51 as described above. When half-rotated, the base plate 21 can be moved by a distance Y that is twice the distance X of the deviation of the central axis.

Therefore, if the second pin 52 is fitted to the frame 22, the first pin 51 is rotated, so that the frame 22 is maximized, and the center axis of the first pin 51 and the second pin 52 is shifted. The distance X can be moved by twice the distance X. From this, the distance X between the center axis AX1 of the first pin 51 and the center axis 52 of the second pin 52 in the eccentric pin 50 is a distance necessary to move the frame 22 slightly relative to the base plate 21. Set it to about half. Further, as the first pin 51 rotates, the second pin 52 is also displaced in a direction perpendicular to the longitudinal direction of the base plate, and the maximum value is the center axis AX1 of the first pin 51 and the second pin 52. This is the distance X of the central axis 52 of the pin 52. Therefore, the length of the long hole 44 provided in the frame 22 may be set according to the displacement distance of the second pin 52.

FIG. 12A is a partial assembly perspective view showing a process of attaching the frame 22 on which the eccentric pin 50 and the inkjet head 20 shown in FIG. 11A are mounted to the base plate 21. As described with reference to FIG. 8D, the convex recess 32 in the mounting portion 30 of the base plate 21 has a holding hole 34 that receives the first pin 51 of the eccentric pin 50 and holds it rotatably. The first pin 51 of the eccentric pin 50 described with reference to FIG. 11A is received in the holding hole 34 in the base plate 21 and is rotatably held.

12B and 13 are partial assembly perspective views showing a process of attaching the frame 22 on which the inkjet head 20 is mounted to the base plate 21 on which the eccentric pin 50 is mounted. In the frame 22 on which the inkjet head 20 is mounted, a convex flat portion 42 provided at one end portion of the frame body 40 is fitted on the convex concave portion 32 of the base plate, and provided at the other end portion. The rectangular flat portion 43 (see FIG. 13) thus fitted is fitted into the rectangular concave portion 33 of the base plate 21. At this time, the second pin 52 of the eccentric pin 50 provided on the base plate 21 is inserted into the long hole 44 in the convex flat portion 42.

The frame 22 fitted into the mounting portion 30 of the base plate 21 is screwed into the base plate 21 by screwing mounting screws 49 into the mounting holes 39 in the convex recess 32 and the rectangular recess 33 of the base plate 21. Can be fixed. As will be described in detail later, the frame 22 can be moved minutely only in the longitudinal direction of the mounting portion 30 with respect to the base plate 21 inside the mounting portion 30. For this reason, the mounting hole 49H (see FIGS. 9A and 9B) of the mounting screw 49 on the frame 22 side is formed as a fool hole that is about 0.5 mm larger than the diameter of the threaded portion of the mounting screw 49 so that the frame 22 can be finely adjusted. It was possible. The attachment hole 49 H may be a long hole that is long in the longitudinal direction of the attachment portion 30.

FIG. 14A is a perspective view showing a state in which the frame 22 on which the inkjet head 20 is mounted is attached to the attachment portion 30 of the base plate 21, and FIG. 14B is a perspective view of the inkjet head assembly 2A shown in FIG. It is sectional drawing in the G line. In a state where the frame 22 on which the inkjet head 20 is mounted is attached to the attachment portion 30 of the base plate 21, as shown in FIG. 14A, the second eccentric pin 50 attached rotatably to the base plate 21. The pin 52 is fitted in the long hole 44 of the frame 22.

In this state, as shown in FIG. 14B, the first pin 51 of the eccentric pin 50 is rotatably held in the holding hole 34 provided in the base plate 21. Further, the lower end portion of the positioning pin 26 fixed to the positioning pin mounting hole 45 of the frame 22 is slidably fitted into a guide groove 35 (see also FIGS. 12A, 12B, and 13) provided in the base plate 21. It is. Therefore, when the first pin 51 of the eccentric pin 50 rotates in the holding hole 34, the second pin 52 having a central axis that is eccentric with respect to the central axis of the first pin 51 passes through the inside of the elongated hole 44. Move and push the plane wall. As a result, the frame 22 is guided by the guide groove 35 and the positioning pin 26 and moves in the longitudinal direction of the base plate 21.

Here, a state in which the second pin 52 is moved by the rotation of the eccentric pin 50 and the frame 22 is slightly moved with respect to the base plate 21 will be described with reference to FIGS. 16A to 16C. 16A to 16C are schematic diagrams for explaining the positional relationship between the positioning pin 26 attached to the frame 22 and the guide groove 35 provided in the base plate 21 according to the rotation state of the eccentric pin 50. The illustration of other fine members is omitted. It is assumed that the positioning pin 26 is slidably fitted in the guide groove 35.

FIG. 15A is a schematic plan view showing the position of the frame 22 when the second pin 52 is in the first position in the long hole 44. In this state, the positioning pin 26 close to the second pin 52 is positioned on the side of the base plate 21 close to the end of the guide groove 35, and the positioning pin 26 far from the second pin 52 is the base plate 21. The guide groove 35 is located on the side close to the opening. The state in which the second pin 52 is changed can be confirmed at the position of the mark 54 attached to the top surface of the second pin 52. FIG. 15B shows a state in which the second pin 52 has moved from the first position shown in FIG. 15A to the second position. In the eccentric pin 50, the second pin 52 can be moved from the first position to the second position by applying a force from the outside to the concave portion 53 on the top surface with a tool such as a flat-blade screwdriver.

When the second pin 52 is moved from the first position shown in FIG. 15A to the second position shown in FIG. 15B, the second pin 52 moves in the long hole 44 while the plane of the long hole 44 is moved. The wall is pushed and the frame 22 is moved relative to the base plate 21. The moving direction of the frame 22 is regulated by the guide groove 35 of the base plate 21 in which the positioning pin 26 is fitted, and the frame 22 can move only in the extending direction of the guide groove 35, that is, the longitudinal direction of the base plate. When the second pin 52 is in the second position, the positioning pin 26 close to the second pin 52 moves away from the terminal end of the guide groove 35 of the base plate 21 and is far from the second pin 52. 26 approaches the terminal portion of the guide groove 35 of the base plate 21.

When the second pin 52 is moved from the second position shown in FIG. 15B to the third position shown in FIG. 15C, the second pin 52 moves in the long hole 44 while the plane of the long hole 44 is moved. The wall is pushed and the frame 22 is further moved relative to the base plate 21. When the second pin 52 is in the third position, the positioning pin 26 close to the second pin 52 is positioned on the side closer to the opening of the guide groove 35 of the base plate 21, The positioning pin 26 far from the pin 52 is positioned closer to the terminal portion of the guide groove 35 of the base plate 21.

As described above, in the disclosed inkjet head assembly, the frame 22 can be moved minutely with respect to the base plate 21 by moving the second pin 52 inside the long hole 44. As a result, in the inkjet head assembly, it is possible to adjust the interval between the boundary portions of the print areas by the adjacent inkjet heads by adjusting the interval between the nozzle holes closest to each other in the adjacent inkjet head.

FIG. 16A shows an eccentric pin 50A of the second embodiment of the micro movement mechanism for moving the frame 22 relative to the base plate 21, the first drive gear 55 for rotating the eccentric pin 50A, and the first in the disclosed inkjet head assembly. It is a perspective view which shows the structure of the drive gear 56 of 2. FIG. In the eccentric pin 50 of the first embodiment, as shown in FIG. 11A, a second pin 52 having a different central axis protrudes from a cylindrical first pin 51, and the first pin 51 is The structure is such that the holding hole 34 provided on the base plate is rotatably held.

On the other hand, the eccentric pin 50A of the second embodiment is that the gear 51G is provided on the outer peripheral portion of the columnar first pin 51 as shown in FIG. 16A. Different from 50. The gear 51G may not be provided on the entire outer periphery of the first pin 51. The first pin 51 provided with the gear 51G on the outer peripheral portion is rotatably held in the holding hole 34 as in the first embodiment. Further, in the eccentric pin 50 of the first embodiment, the slit-like recess 53 provided at the tip of the second pin 52 is moved from the outside, and the first pin 51 is rotated. On the other hand, in the eccentric pin 50A of the second embodiment, the gear 51G provided on the outer peripheral portion of the first pin 51 is rotated by the first and second drive gears 55 and 56 that mesh with the gear 51G. The mark 54 which shows a rotation position is attached | subjected to the top surface of the 2nd pin 52, and is the same as 1st Example.

As shown in FIG. 16D, the first drive gear 55 and the second drive gear 56 are provided in the internal space of the base plate 21, and the second drive gear 56 is provided on the side surface of the holding hole 34. The gear 51G provided on the outer periphery of the first pin 51 is meshed with the opening. The gear 51G is provided with a rotation shaft 58, and the rotation shaft 58 can be rotatably supported in a shaft hole 59 provided in the base plate 21. An adjustment rod 57 projects from the first drive gear 55 that meshes with the second drive gear 56, and the tip of the minus rod driver can be inserted into the tip of the adjustment rod 57. A slit-like recess 53A having a predetermined depth is provided. The tip of the adjustment rod 57 is exposed on the upper surface of the base plate 21 or protrudes from the upper surface. Although the number of teeth of the first drive gear 55 and the second drive gear 56 may be the same, the gear 51G can be rotated with a small force because the number of teeth is smaller than the fraction of the gear 51G.

Further, the position where the first drive gear 55 and the second drive gear 56 are provided inside the base plate 21 is not particularly limited as long as the gear 51G can be rotated. It can be provided in the space. FIG. 16B is an example in which the first drive gear 55 and the second drive gear 56 are arranged in the longitudinal direction of the base plate 21, and FIG. 16C shows the first drive gear 55 and the second drive gear 56. In this example, the base plates 21 are arranged in a direction perpendicular to the longitudinal direction. Furthermore, by inserting another drive gear between the first drive gear 55 and the second drive gear 56, the distance from the second pin 52 to the adjustment rod 57 can be freely changed.

In the eccentric pin 50 of the first embodiment, when the frame 22 is slightly moved with respect to the base plate 21, a slit-like recess 53 provided at the tip of the second pin 52 is used as a tool such as a minus driver. It was moved from outside. On the other hand, in the eccentric pin 50A of the second embodiment, the first and second drive gears 55 and 56 mesh with the gear 51G provided on the outer peripheral portion of the first pin 51. Therefore, if the adjustment rod 57 protruding from the upper surface of the frame 21 is rotated from the outside with a tool such as a flat-blade screwdriver, the first drive gear 55 can be rotated to slightly move the frame 22 relative to the base plate 21. it can.

FIG. 17A is a partial perspective view showing the structure of a third embodiment of the micro movement mechanism for moving the frame 22 relative to the base plate 21 in the disclosed inkjet head assembly. The structure of the frame 22 and the structure of the base plate 21 are the same as the structure of the frame 22 and the structure of the base plate 21 in the embodiments described so far, except for the portion of the fine movement mechanism, and therefore the same components are the same. Reference numerals are assigned and explanations thereof are omitted. In the first embodiment of the micro movement mechanism, the eccentric pin 50 shown in FIG. 11A is provided between the base plate 21 and the frame 22, and in the second embodiment, the eccentric pin 50A shown in FIG. The first and second drive gears 55 and 56 are provided between the base plate 21 and the frame 22.

On the other hand, in the third embodiment of the minute movement mechanism, as can be seen from the partial perspective view shown in FIG. 17A and the cross-sectional view shown in FIG. A columnar protrusion 61 is provided at a position where the long hole is present. Furthermore, in the third embodiment of the micro-movement mechanism, a cylindrical shape having the same shape as the cylindrical projection 61 at a position on the upper surface of the base plate 21 where the cylindrical projection 61 provided on the frame 22 can be seen. Projection 62 is provided. In the third embodiment of the minute movement mechanism, the protrusion 61 can be moved with respect to the protrusion 62 using the jig 70 shown in FIG. 18A.

FIG. 18A is a plan view showing a jig 70 used in the third embodiment of the micro movement mechanism shown in FIG. 17A. The jig 70 is provided with a long hole 71 capable of receiving a columnar protrusion 61 at the tip thereof, and a cylindrical shape on the upper surface of the base plate 21 at a position away from the long hole 71 by a predetermined distance. A circular through-hole 72 into which the projection 62 can be fitted is provided. In this jig 70, the distance from the center of the long hole 71 to the center axis of the through hole 72 is set so that the columnar protrusion 61 provided on the frame 22 and the center axis of the columnar protrusion 62 provided on the base plate 21. The distance between them may be used.

In the third embodiment of the micro movement mechanism, as shown in FIGS. 18B and 18C, after the frame 22 on which the inkjet head 20 is mounted is attached to the attachment portion 30 of the base plate 21, the treatment shown in FIG. 18A is performed. The position of the frame 22 with respect to the base plate 21 is adjusted with the tool 70. The jig 70 is used by fitting the long hole 71 into the columnar protrusion 61 provided in the frame 22 and fitting the through hole 72 into the columnar protrusion 62 provided in the base plate 21.

As shown in FIG. 18C, the length L1 from the through hole 72 of the jig 70 to the end of the gripping portion 73 of the jig 70 is longer than the length L2 from the long hole 71 of the jig 70 to the through hole 72. Keep it long enough. When the frame 22 is slightly moved with respect to the base plate 21, the gripping portion 73 of the jig 70 is moved in the direction indicated by the arrow U in the state shown in FIG. 18C. Then, the through-hole 72 of the jig 70 serves as a fulcrum, and the long hole 71 serves as an action point. As shown in FIG. 18B, the columnar protrusion 61 provided on the frame 22 by the long hole 71 is indicated by an arrow W. The frame 22 can be moved minutely with respect to the base plate 21.

As described above, in the disclosed inkjet head assembly, the frame can be finely moved with respect to the base plate after assembling the printing apparatus, so that the interval between the borders of the print areas by the adjacent inkjet heads is adjusted. Can do. As a result, it is possible to easily adjust the seam of the print area existing in the width direction of the print medium, and it is possible to realize good printing in the printing apparatus.

Claims

An ink-jet head assembly comprising a plurality of ink-jet heads arranged in a print area in a width direction of the print medium on a base plate facing the print medium,
A frame on which one of the plurality of inkjet heads is fixed and attached to an attachment portion on the base plate;
Provided between each piece of the frame and the base plate, and provided with a micro movement mechanism that is displaced by application of an external force and moves the frame with respect to the base plate.
The attachment portion is an ink jet head assembly formed so that the frame can be moved in the direction of the adjacent attachment portion when the minute movement mechanism is displaced and the frame is minutely moved.
The inkjet head assembly according to claim 1,
An ink-jet head assembly, wherein the attachment portion is formed in a recess into which the frame can be fitted, and the overall length in the longitudinal direction of the recess is longer than the overall length in the longitudinal direction of the frame.
An inkjet head assembly according to claim 2,
The minute movement mechanism is an eccentric pin provided between each piece of the frame and the recess of the mounting portion;
The frame is provided with a long hole extending in a direction perpendicular to the width direction of the print medium,
The eccentric pin includes a first pin having a central axis on the base plate, and a second pin protruding from the first pin, the central pin having an axis shifted from the central axis. Formed from
The tip of the second pin is fitted in the elongated hole,
When the eccentric pin is rotated from the outside, the side surface of the second pin presses the flat wall of the elongated hole, whereby the position of the frame with respect to the base plate is changed.
An inkjet head assembly according to claim 3,
An ink-jet head assembly in which a tip portion of the second pin is formed with a recess capable of receiving a pressing force from the outside and moving the second pin to rotate the eccentric pin.
An inkjet head assembly according to claim 3 or 4,
The long hole is an ink jet head assembly provided at a position of one end in the longitudinal direction of the frame.
An inkjet assembly according to claim 3,
A gear is formed on at least a part of the outer peripheral surface of the first pin, and the first pin is rotated about the central axis by rotating another gear engaged with the gear from the outside. Inkjet head assembly.
The inkjet assembly according to claim 6, comprising:
The rotating shaft of the gear farthest from the gear provided on the outer peripheral surface of the first pin of the other gear is the adjustment rod, and its tip protrudes from the upper surface of the base plate.
An inkjet head assembly in which a concave portion capable of rotating the adjustment rod from the outside is formed at a tip portion of the adjustment rod.
An inkjet assembly according to claim 6 or 7,
The number of teeth of the other gear is an inkjet head assembly that is smaller than the number of teeth of the gear provided on the outer peripheral surface of the first pin.
An inkjet head assembly according to claim 2,
The minute movement mechanism is a first protrusion protruding from the upper surface of the frame and a second protrusion protruding so as to see the first protrusion on the upper surface of the base plate;
The first protrusion is formed so as to be rotatable with respect to the second protrusion using a jig.
The jig includes an elongated hole through which the first protrusion is inserted, a circular hole through which the second protrusion is inserted, and a grip portion extending on a line connecting the elongated hole and the circular hole. Head assembly.
An inkjet head assembly according to any one of claims 1 to 9,
The inkjet head is positioned on the frame by two positioning pins protruding at both ends in the longitudinal direction of the frame,
The lower end portions of the two positioning pins project from the lower surface of the frame,
An ink jet head assembly in which the mounting portion of the base plate is provided with a guide groove that receives the lower end portions of the two positioning pins and restricts the moving direction in the longitudinal direction of the base plate.
An inkjet head assembly according to claim 10,
The inkjet head includes a rectangular nozzle forming region having a plurality of nozzle holes for ink ejection,
The inkjet head is fixed to the frame by alignment plates attached to both ends in the longitudinal direction of the inkjet head,
The alignment plate includes a protruding piece having a V-shaped groove at one end in the longitudinal direction and a side parallel to the longitudinal direction at the other end,
The frame includes an opening through which the nozzle hole can be seen from the printing surface side,
The inkjet head assembly is an inkjet head assembly fixed to the frame in a state where the two positioning pins are in contact with the V-shaped groove and the protruding piece.
The inkjet head assembly according to any one of claims 1 to 11,
The mounting hole of the frame provided at a position facing the base plate side mounting hole of the frame provided in the base plate is larger than the diameter of the base plate side mounting hole, or the longitudinal direction of the base plate Inkjet head assembly formed into a long slot.