JP7659726B2 - Inkjet printer - Google Patents

Description

The present invention relates to an inkjet-based drawing device such as a digital printer, and in particular to an inkjet printer equipped with a press mechanism that prevents the drawing medium, such as paper, from lifting up when it is in the drawing position.

In recent years, inkjet printers, which perform drawing by spraying fine ink droplets from a drawing head onto a drawing medium, have come to be known that use a line-type head system that allows drawing on the entire medium by transporting the drawing medium while keeping the drawing head fixed, rather than a serial-type head system in which the drawing head moves back and forth perpendicular to the direction in which the drawing medium is transported to perform drawing.

In a drawing device, in order to prevent the paper at the drawing position from floating up, a method is known in which a platen with many holes is prepared under the paper at the drawing position, and drawing (ink is ejected from the inkjet head) is performed while the paper (drawing medium) is adsorbed onto the platen by sucking in air through the holes.
Also, when there are multiple widths of paper used for drawing, the platen's air intake holes need to be large enough to cover the widest paper, but in the case of narrow paper, some of the platen's air intake holes cannot be blocked by the paper, making it impossible to maintain sufficient suction power. Therefore, a method is sometimes used to block the air intake holes on the outside of the paper's width that cannot be blocked by the paper with a paper presser (film) that presses down on the edge of the paper, thereby maintaining suction power.

Patent document 1 discloses a technique for more reliably suctioning the medium at the drawing position by suctioning air in order to prevent the edge of the medium at the drawing position from curling and lifting up in an inkjet printer.

Patent Document 2 also discloses a technology for controlling the amount of ink ejected from an inkjet printer to prevent tiny ink droplets that separate from the main droplets ejected from the drawing head from landing in an irregular manner due to the influence of air currents caused by air suction during paper transport or transport air currents generated by the movement of the paper, thereby soiling the paper.

JP 2012-196821 A JP 2015-024598 A

As shown in FIG. 27, the drawing medium 2 in the drawing position is attracted to the platen 31 by creating a negative pressure on the back of the platen, drawing in air through multiple intake holes 32. The intake holes 32 on the platen 31 are arranged to accommodate different sizes of drawing medium. In the case of a small (narrow) drawing medium, it is not possible to block all of the intake holes 32 with the drawing medium 2. Therefore, it is possible to provide a configuration in which the intake holes 32 outside the width of the medium are blocked by a film-like paper holder 34 that moves according to the width of the drawing medium 2.

However, as shown in Figure 28, since the intake holes 32 on the platen 31 are arranged at regular intervals, it is possible that the edge of the drawing medium 2 being used cannot completely block the intake holes. Also, since a certain amount of space is required between the film-like paper holder 34 and the edge of the drawing medium 2, there is a concern that the intake from the intake hole 321 that cannot be completely blocked will cause turbulence in the air flow at the edge of the drawing medium, and the fine ink particles sprayed from the drawing head 41 near the edge of the drawing medium will not be able to travel in a straight line toward the medium, resulting in a disturbance in the drawn image.

In addition, the paper holder 34 overlaps the widthwise edge of the paper (drawing medium) to physically hold the edge down so that it does not float up. However, when the inkjet head is positioned above the paper during drawing, the paper holder 34 cannot overlap the edge of the paper in order to avoid contact between the ejection surface of the inkjet head and the paper holder 34. Therefore, in the area where the inkjet head is positioned during printing, a small gap is created between the edge of the paper and the paper holder, and the ink droplets ejected from the inkjet head are swept away before landing on the paper due to the airflow between the inkjet head and the paper caused by the intake air from the intake hole 321 on the platen 31, which cannot be blocked by the paper and the paper holder 34, and this can cause image distortion due to misalignment of the ink landing at the edge of the paper.

The present invention has been proposed in light of the above situation, and aims to provide an inkjet printer that enables high-quality drawing at the edge of the medium, even when the drawing medium has a different width.

In order to achieve the above object, the present invention (claim 1) is an inkjet printer that performs drawing on drawing media (2) of different medium widths using a drawing head (41), and is characterized by including the following configuration.
A pair of film-like paper holders (34) cover the air intake holes (32) located on both outer sides of the drawing medium (2) from above the platen (31) relative to the multiple air intake holes (32) provided in the platen (31) through which the drawing medium (2) is transported.
a pair of hole blocking members (35) that are elongated in the transport direction of the drawing medium (2) and that are movable in the width direction of the drawing medium (2) and block a portion of the air intake hole (32) from below the platen (31);
A support portion (100) supports the paper presser (34) so as to enable position adjustment movement in the width direction.
A link mechanism (first connecting portion 125) that adjusts the position of the hole closing member (35) by moving in the width direction in conjunction with the movement of the support portion (100) in the width direction.

Claim 2 provides the ink jet printer of claim 1,
The support portion (100) is characterized by having an opening/closing mechanism (second connecting portion 140) that is rotatable about an axis (step portion 103a) along the conveying direction.

Claim 3 is the ink jet printer of claim 2,
The opening/closing mechanism (second connecting portion 140) is characterized by comprising a spherical bearing (107) fixed to the support portion (100) and having a spherical portion (107a), and a spherical body (108) that fits into the spherical portion (107a).

Claim 4 provides the ink jet printer of claim 1,
The paper presser (34) is characterized in that stepped portions (344) are provided at an inner end thereof at intervals in the conveying direction.

Claim 5 is the ink jet printer of claim 4,
A groove (351) is provided in the hole closing member (35) below the installation portion of the step piece (344).

Claim 6 is the ink jet printer of claim 2 ,
The support portion (100) is provided with a handle (113) for moving the opening/closing mechanism and for adjusting the position.

Claim 7 is the ink jet printer of claim 1,
The paper holder (34) is characterized in that it is supported on the support portion (100) by a knurled screw (343).

According to claim 1, when the support part (100) is moved to adjust its position in the width direction in accordance with the width of the drawing medium, the link mechanism causes the hole sealing member (35) to move in conjunction with the paper holder (34) in accordance with the width of the drawing medium, so that when adjusting the position of the paper holder (34) that seals the air intake hole (32) on the outside of the drawing medium (2) on the platen (31) to the width of the drawing medium (2), it is possible to simultaneously adjust the hole sealing member (35) to the appropriate position.
This eliminates the need to check the position of the hole closing member (35), which is difficult to align visually, and reduces the effort required to align the position of the paper holder (34) and the position of the hole closing member (35) to the width of the drawing medium (2).
Furthermore, since the hole sealing member (35) can reliably seal the intake hole (32) located at the widthwise end of the drawing medium on the platen (31), it is possible to suppress airflow disturbances that prevent fine ink particles from the drawing head (41) sprayed near the end of the medium from traveling in a straight line toward the drawing medium (2), ensuring proper drawing at the end of the medium regardless of the width of the drawing medium (2).

According to claim 2, the paper holder (34) provided on the outside of the drawing medium (2) can be opened and closed by the flip-up action of the opening and closing function of the support part (100).

According to claim 3, the spherical portion (107a) of the spherical bearing (107) can slide and tilt relative to the spherical body (108), forming an opening and closing mechanism.

According to claim 4, by providing a stepped portion (344) at the inner end of the paper holder (34), the end of the drawing medium can be pressed against the platen (31) so that the end of the drawing medium does not curl and lift off the platen (31).

According to claim 5, by providing a groove portion (351) in the hole blocking member (35) at the lower part of the installation part of the step portion (344), it is possible to reliably promote adhesion of the end of the drawing medium to the platen (31) through the intake hole (32) in this part.

According to claim 6, by providing a handle (113) on the operating side of the support part (100), it is possible to open and close the paper holder (34) and adjust the positions of the paper holder (34) and the hole closing member (35) at the outer fulcrum.

According to claim 7, the paper holder (34) is supported on the support portion (100) by a knurled screw (343), making it easy to attach and detach the paper holder (34).

1 is a schematic front view showing the entire apparatus of an inkjet printer according to an embodiment of the present invention; 1 is a schematic side view showing the entire apparatus of an inkjet printer according to an embodiment of the present invention; FIG. 1 is a perspective view illustrating an entire printing unit of an inkjet printer (only one of four drawing heads is shown). 1A is a cross-sectional explanatory diagram showing the schematic configuration of a printing unit (when a narrow drawing medium is used), and FIG. 1B is an enlarged explanatory diagram of the dotted line portion of FIG. 1A is a cross-sectional explanatory diagram showing the schematic configuration of a printing unit (when a wide drawing medium is used), and FIG. 1B is an enlarged explanatory diagram of the dotted line portion of FIG. FIG. 13 is an explanatory plan view of the printing unit (when a narrow drawing medium is used). FIG. 13 is an explanatory plan view of the printing unit (when a wide drawing medium is used). FIG. 13 is an explanatory plan view of a printing section that constitutes a printing unit (when a narrow drawing medium is used). FIG. 4 is an explanatory plan view of a printing section that constitutes a printing unit (when a wide drawing medium is used). FIG. 13 is an explanatory plan view showing a part of the internal structure of the printing unit (when a narrow drawing medium is used). FIG. 13 is an explanatory plan view showing a part of the internal structure of the printing unit (when a wide drawing medium is used). FIG. 13 is a cross-sectional explanatory diagram of a printing section that constitutes a printing unit (when a narrow drawing medium is used). FIG. 4 is a cross-sectional explanatory diagram of a printing section that constitutes a printing unit (when a wide drawing medium is used). 13 is an explanatory cross-sectional view of the printing section that constitutes the printing unit when the paper holder is lifted up (when a narrow drawing medium is used). FIG. 13 is an explanatory cross-sectional view of the printing section of the printing unit when the paper holder is lifted up (when a wide drawing medium is used). FIG. 4A and 4B are side views illustrating a hole closing member. FIG. 13 is a perspective explanatory view showing a connection structure in the support portion as viewed from the outside. FIG. 13 is a perspective explanatory view showing a connection structure in the support portion as viewed from the inside. FIG. 13 is an explanatory perspective view seen from the outside, showing an exploded structure of the connection in the support portion. FIG. 13 is an explanatory perspective view from the inside showing an exploded structure of the connection in the support portion. 13A and 13B are cross-sectional explanatory views for explaining a second connecting portion (in a normal state) in the support portion. 13A and 13B are cross-sectional explanatory views for explaining a second connecting portion in the support portion (when flipped up). 21(A) and 21(B) are enlarged cross-sectional explanatory views of the dotted lines in FIG. 21(B) and FIG. 22(B). 13 is a model diagram (a cross-sectional view before pressing by the stepped portion) illustrating the effect of the stepped portion. FIG. 13 is a model diagram (cross-sectional view after pressing by the stepped portion) illustrating the effect of the stepped portion. FIG. FIG. 13 is a model diagram (plan view) illustrating a structure for preventing the drawing medium from floating up. FIG. 1 is a model diagram (sectional view) of a conventional structure in which an intake hole is provided on a platen of an inkjet printer. FIG. 28 is a model diagram (cross-sectional view) illustrating a state in which turbulence in the air flow occurs at the edge of the drawing medium in the structure of FIG. 27 .

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.
An inkjet printer according to one embodiment of the present invention is configured to include a printing device having a drawing head that ejects water-based ink onto a drawing medium to perform drawing, a transport device that transports the roll-shaped drawing medium in a desired manner, and a drying device that dries and fixes the water-based ink ejected onto the drawing medium.

As shown in Figs. 1 and 2, the printing device 1 includes a housing 10 that houses electrical equipment such as a pump for supplying ink for drawing and a power supply, a print base 20 that is placed on the housing, a print unit 30 that has the function of adsorbing the drawing medium 2 being transported to prevent it from floating up, and a head unit 40 that has a movable mechanism that allows the drawing head 41 to be retracted from the drawing medium 2.

A printing unit 30 is provided on the front side of the printing base unit 20 (FIGS. 1 and 2) and has a function of adsorbing the drawing medium 2 being transported to prevent it from floating up.
The printing unit 30 has an overall shape of a rectangular box, and the drawing medium 2 is transported over a platen 31 attached to the upper surface of the box. The platen 31 is provided with a plurality of air intake holes 32 to attract the transported drawing medium 2 from the underside and prevent the drawing medium 2 from floating up. An air chamber 33 in which a negative pressure is maintained is provided below the platen 31 of the printing unit 30. A vacuum blower 60 is connected to the air chamber 33 via a duct 61, making it possible to draw air through the air intake holes 32 provided in the platen 31.

The head unit 40 has four drawing heads 41 that are positioned at offset positions in the transport direction of the drawing medium 2, and two of them form one set to cover the entire width of the drawing medium and draw (print). In this example, two sets of drawing heads 41a and 41b, and drawing heads 41c and 41d each sequentially eject ink of a different color (e.g., three primary colors plus black), making it possible to draw (print) a color image across the entire width of the drawing medium 2.

3 to 5, a pair of paper pressers 34 for pressing down the edges of the drawing medium 2 are provided on both sides of the platen 31 in the transport direction. Note that in Fig. 3, only one drawing head 41 is shown for simplicity.
The pair of paper holders 34 are connected by an operating mechanism possessed by a support part 100 arranged at the end of the printing part 30 so that they can be moved in a direction perpendicular to the transport direction (width direction) in accordance with the width of the drawing medium 2, and can be opened and closed by lifting the inside of the paper holders 34 upward.
Fig. 4 shows the state in which the paper holder 34 has been moved to correspond to a narrow drawing medium 2, and Fig. 5 shows the state in which the paper holder 34 has been moved to correspond to a wide drawing medium 2. The air chamber 33 is also provided with a pair of plate-shaped hole blocking members 35 that move in conjunction with the moved position of the paper holder 34 and block some of the air intake holes 32 from the inside.
That is, when the position of the paper holder 34 that closes the intake holes 32 on the outer side of the drawing medium 2 on the platen 31 is adjusted to the width of the drawing medium 2, the hole closing member 35 is configured to simultaneously adjust to an appropriate position in conjunction with the movement of the paper holder 34 according to the medium width. The detailed structure of the support part 100, including the operating mechanism for the paper holder 34 and the hole closing member 35, will be described later.

At the entrance side of the printing unit 30 in the transport direction of the drawing medium 2, an encoder 36 is provided that generates an electric pulse signal in response to the transport of the drawing medium 2, and a sensor 37 is provided for reading marks that have been previously drawn on the drawing medium 2. This enables drawing with the drawing head 41 in response to the amount of transport of the drawing medium 2, and drawing that is aligned with a previously drawn image.

A head unit 40 is provided on the top of the printing unit 30. The head unit 40 is equipped with a plurality of drawing heads 41 that perform drawing on the transported drawing medium 2, and an ink circulation unit that supplies ink used by the drawing heads 41 for drawing.
On the left, right, and rear sides of the printing unit 30, there are provided head moving units 42 which are equipped with shafts, steel belts, bearing devices, motors, etc. for moving the head unit 40, on which the drawing head 41 is mounted, so that it can be retracted in the front-to-rear direction of the printing device 1 (Figure 1), enabling highly accurate position control of the drawing head 41 on the platen 31.

A maintenance section 45 is provided at the lower back surface of the printing unit 30, and has a cap section (not shown) that seals the ink ejection surface of the drawing head 41 to prevent it from drying out when the drawing head 41 is in a standby state where it is not performing drawing operations, and that receives ink discharged when the drawing head 41 is cleaned.
In addition, a wiper blade (not shown) is provided for removing ink remaining on the ink ejection surface after ink is discharged during cleaning of the drawing head 41, enabling stable ejection of ink from the drawing head 41.

The head unit 40 has a movable mechanism that can change the position of the drawing head 41 relative to the drawing medium 2. For example, the head unit 40 uses a motor and a ball screw structure to move the entire head unit up and down, and is configured to properly maintain the distance between the drawing medium 2 on the printing unit 30 and the ink ejection surface of the drawing head 41.
The drawing head 41 is provided with a line-type discharge portion that performs drawing while holding the drawing medium 2 in a predetermined position as it is transported from the medium inlet to the medium outlet, thereby enabling high-speed drawing.

At the bottom of the housing 10, there are provided a power supply storage section 50 that stores a power supply for operating the drawing head 41, a power supply for driving the motor that moves the head position, a power supply for operating the control board, etc., and a vacuum blower 60 that is used to adsorb the drawing medium 2 to prevent it from floating up in the printing section 30. At the rear side of the housing 10, there are provided a plurality of tanks 70 for temporarily storing ink to be supplied to the drawing head 41, a pump 80 for supplying drawing ink to the tanks 70, and a pump 80 for flushing cleaning liquid and waste liquid.
A printed circuit board 90 for controlling the drawing head 41 and a printed circuit board 90 for driving a pump, a motor, etc. are installed on the side of the housing unit 10, enabling control of the position of the drawing head 41 and proper drawing of drawing data received from an external interface.

Next, a more detailed structure of the printing unit 30, which has the function of preventing the drawing medium 2 from floating up, will be described with reference to Figs. 6 to 26. In Figs. 6 to 26, parts having the same configuration as Figs. 1 to 5 are given the same reference numerals. Figs. 6 to 11 show explanatory plan views of the printing unit 30, and Figs. 12 to 15 show explanatory cross-sectional views of the printing unit 30.

The platen 31, which is installed over the entire top surface of the printing unit 30, is perforated with a large number of circular intake holes 32. As shown in Figures 6 to 9, the intake holes 32 are composed of intake holes 32a provided in areas other than the installation width of the drawing head 41, and intake holes 32b provided in the installation width (width in the medium transport direction) of the drawing head 41. The intake holes 32b are fewer in number per unit area than the intake holes 32a, and are also formed with a smaller diameter. This is to reduce the disturbance of ink discharge caused by the influence of intake air on the underside of the drawing medium 2 corresponding to the drawing head 41, and to maintain drawing quality.

Specifically, in an area corresponding to the width of the drawing head 41 in the transport direction, six rows of intake holes 32a are provided, whereas two rows of intake holes 32b are provided. Also, the diameter of intake holes 32b is approximately 1/4 the diameter of intake holes 32a. The intake holes 32a and 32b are installed at the same intervals in the drawing medium width direction.

A pair of film-like paper holders 34 for blocking the intake holes 32 on the outside of the drawing medium 2 transported on the platen 31 are attached to the printing unit 30 via the support unit 100. The paper holder 34 is composed of a rectangular film portion 341 and a metal portion 342 that borders the film portion 341 except for the side where the drawing medium 2 is transported, and is fixed to the support unit 100 by knurled screws 343 at both ends of the metal portion 342 in the transport direction. Fixing the paper holder 34 to the support unit 100 by the knurled screws 343 makes it easy to attach and detach.

Furthermore, a number of stepped pieces 344 are attached to the film portion 341 of the paper holder 34 at intervals in the transport direction of the inner end of the paper holder 34. The stepped pieces 344 have the role of promoting adhesion by pressing down the end of the drawing medium so that the end of the drawing medium does not curl and lift off the platen 31. Furthermore, each stepped piece 344 is positioned so that it does not overlap with the drawing head 41. This is for the following reasons.

That is, the paper presser 34 has the dual roles of blocking the intake holes 32 of the platen 31 and promoting adhesion by pressing down the edge of the drawing medium 2 (FIG. 24). The drawing medium 2 pressed down by the paper presser 34 is a medium called tack paper, which is composed of three layers: a surface base material, an adhesive material, and a release paper. If the edge of the drawing medium 2 rubs against the paper presser 34 while the drawing medium 2 is being transported, the adhesive material adheres to and accumulates on the paper presser 34, adversely affecting printing and transportation. For this reason, the paper presser 34 has a step portion 344 at a step higher than the drawing medium 2 so that it does not come into contact with the edge of the drawing medium 2 after the drawing medium 2 has been attracted to the platen 31 (FIG. 25).
The drawing head 41 is positioned above the paper holder 34 during printing, but if the paper holder 34 comes into contact with the drawing head 41, there is a possibility that dirt will adhere to the drawing head 41. If dirt adheres to the drawing head 41, it will adversely affect printing, so a structure is required in which the paper holder 34 and the drawing head 41 do not come into contact with each other.

However, because the gap between the drawing medium 2 and the drawing head 41 needs to be 1 mm or less, if the stepped portion 344 of the paper holder 34 is positioned below the drawing head, there is a risk of the drawing head 41 coming into contact with the stepped portion 344. Therefore, the stepped portion 344 of the paper holder 34 is configured not to be positioned below the drawing head. (Figures 6 to 11)

Since the air intake holes 32 in the areas where the step pieces 344 are not disposed are not blocked, the airflow becomes turbulent, causing distortion of the drawn image in the vicinity of the edges of the drawing medium (FIG. 28).
Furthermore, since the step portion 344 is disposed at a position where it does not overlap with the drawing head 41, the length in the transport direction also differs depending on the installation position.

A pair of hole blocking members 35 are attached below the platen 31 and are movable in the width direction of the drawing medium 2 to block some of the air intake holes 32 from below the platen 31. As shown in Figures 10 and 11, each hole blocking member 35 is formed long in the transport direction of the drawing medium 2, and is configured so that the length corresponding to the width direction of the drawing medium 2 is greater than the diameter of the air intake holes 32, thereby simultaneously blocking multiple air intake holes 32 lined up in a line in the transport direction.

In addition, grooves 351 are provided in hole closing member 35 at positions corresponding to the lower portions of the installation portions of step pieces 344. The positions of step pieces 344 in hole closing member 35 differ between the upper position (step pieces 344 are installed in two locations) and the lower position (step pieces 344 are installed in three locations) in Fig. 10, and therefore the shapes of hole closing member 35 differ as shown in Figs. 16(A) and 16(B).
The groove 351 is provided in the hole blocking member 35 located below where the step portion 344 is installed in order to assist in adhesion of the image medium 2 to the platen 31 by not blocking the air intake hole 32 present in this area.

The support unit 100 is located on both sides of the platen 31 as shown in Figures 6 to 15, and is configured to include a long flat plate 101 that extends along the side surface of the printing unit 30 as shown in Figures 17 to 23, and a first connecting piece 104 with an L-shaped cross section to which the flat plate 101 is attached. The ends of each first movable shaft 120 are fixed to the flat plate 101 by bolts 102 to form a first connecting portion (width-direction movable shaft connecting portion) 125 with which the first movable shaft 120 moves in conjunction with the movement of the support unit 100 in the width direction.
A pair of fixed pieces 105 (Figures 18 and 20) are attached to the first connecting piece 104 with a gap between them, and a stepped bolt 103 is passed through a hole 105a provided in this fixed piece 105 and fixed to both end faces of the flat body 101, so that the stepped portion 103a of the stepped bolt 103 becomes an axis along the transport direction of the drawing medium 2, and the first connecting piece 104 is tiltably connected to the flat body 101 and the first movable shaft 120 along its extension.

An L-shaped second connecting piece 106 is fixed to the approximate center below the first connecting piece 104. A spherical body 108 (FIG. 23) constituting an opening/closing mechanism described below is fixed to the end of the movable shaft 130. The spherical body 108 is configured in a shape with both side surfaces perpendicular to the axis (diameter) of the sphere flattened, and is fixed to the end of the movable shaft 130 by a bolt 111 inserted into a through hole 108a that passes through in the axial direction.
A hole 106a is formed in the second connecting piece 106, and a spherical body 108 is arranged in a state where it fits into a spherical portion 107a formed in the center of a doughnut-shaped spherical bearing 107 on the side opposite to the movable shaft 130. A part of the spherical body 108 is located within the hole 106a, and the spherical bearing 107 is pressed down by a spherical bearing cover 109 fixed with a bolt 110, thereby being arranged.

The metal part 342 of the film-shaped paper holder 34 is attached along the longitudinal direction of the first connecting piece 104. A handle 113 is fixed to the second connecting piece 106 of the first connecting piece 104 via a handle connecting part 112.

With the above configuration, as shown in Figs. 21 to 23, the spherical body 108 and the spherical portion 107a of the spherical bearing 107 slide and move, so that the first connecting piece 104 and the second connecting piece 106 are connected to the second movable shaft 130 in a tiltable manner, and the second movable shaft 130 forms a second connecting portion (a shaft connecting portion capable of being flipped up) 140 along which the second movable shaft 130 moves linearly. That is, the flip-up operation of the support portion 100 caused by pushing the handle 113 downward causes the first connecting piece 104 and the second connecting piece 106 to rotate about the step portion 103a, and the spherical bearing 107, which is tilted accordingly, pushes the spherical body 108 inward (to the left in Figs. 21 to 23), thereby moving the movable shaft 130 (converting the rotation into linear movement). At this time, the second connecting piece 106 and the spherical bearing cover 109 move slightly vertically relative to the spherical bearing 107, as shown in Fig. 23.
Furthermore, by providing a handle 113 on the operation side of the support portion 100, it becomes possible to open/close and adjust the position of the paper holder 34, which will be described later, at the outer fulcrum.

The support parts 100 located on both sides of the platen 31 are connected to each other by a connecting mechanism. The connecting mechanism includes a link mechanism that causes the paper holder 34 and the hole closing member 35 connected to the support parts 100 to move in the width direction, and an opening/closing mechanism that causes the paper holder 34 to flip up by rotating around the step part (103a).

As shown in Figures 17 to 20, the link mechanism including the first connecting portion 125 comprises two first movable shafts 120 connecting each support portion 100 and the hole sealing member 35, and a rack 121 connected to the center position of the hole sealing member 35 in the conveying direction, each rack 121 is connected to each support portion 100 at a position offset in the conveying direction, vertical grooves 122 are formed along the width direction on the opposing surfaces of the racks, and a pinion 123 that engages between the vertical grooves of the racks is arranged at the center position in the width direction (Figures 10 and 11).
In other words, when the handle 113 is moved in the width direction of the drawing medium 2 and the first movable shaft 120 of one of the support parts 100 moves linearly in the width direction, the movement of the first movable shaft 120 moves the rack 121 and first movable shaft 120 of the other support part 100 via the rack 121 and pinion 123, and the position of the other support part 100 moves linearly in the width direction in conjunction with the movement of the first movable shaft 120.
With regard to the position (linear movement) of the support part 100, examples adapted to a narrow drawing medium are shown in FIGS. 6, 8, 10, and 12, while examples adapted to a wide drawing medium are shown in FIGS.

The opening and closing mechanism including the second connecting portion 140 comprises a second movable shaft 130 connected between each support portion 100 and the joint portion 129, and a rack 131 connected to the joint portion 129, each rack 131 being connected to each support portion 100 at a position offset in the conveying direction, vertical grooves 132 being formed along the width direction on the opposing surfaces of the racks, and a pinion that engages between the vertical grooves of the racks is arranged at the center position in the width direction.
The other end of the second movable shaft 130 is fixed to the second connecting part 140 which allows the support part 100 to tilt and move. Also, as described above, the other end of each first movable shaft 120 is fixed to the first connecting part 125 formed on the flat plate body 101, and the first connecting piece 104 is connected to this flat plate body 101 in a tiltable manner. With this structure, the rotational motion caused by the flip-up action is converted into linear motion of the second movable shaft 130 via the second connecting part 140.

In other words, when the handle 113 is pushed down, one of the support parts 100 tilts and rotates around the step (axis) 103a of the stepped bolt 103 to perform a flip-up operation, the rotation is converted into linear movement in the width direction of the second movable shaft 130 via the second connecting part 140, and the movement of the second movable shaft 130 moves the other second movable shaft 130 via the rack and pinion, and the position of the other support part 100 rotates according to the same principle to perform the flip-up operation (opening and closing) .
FIG. 14 shows an example of the support portion 100 performing a flip-up operation on a narrow drawing medium, and FIG. 15 shows an example of the support portion 100 performing a flip-up operation on a wide drawing medium.

In an inkjet printer having the above-described structure, the position of the paper holder 34 in the paper width direction is moved according to the paper width when used, but the hole blocking member 35, which moves in conjunction with the width direction movement of the paper holder 34 via the support part 100, blocks the air intake holes 321 on the platen 31 that cannot be blocked by the drawing medium 2 and the paper holder 34 from the back side of the platen 31, as shown in Figure 26.
With this structure, the hole sealing member 35 can reliably seal the intake holes 32 located at the widthwise end of the drawing medium on the platen 31, suppressing airflow disturbances that prevent the fine ink particles from the drawing head 41 sprayed near the end of the drawing medium from traveling in a straight line toward the medium, thereby preventing image distortion due to misalignment of the ink landing position. Regardless of the width of the drawing medium 2, proper drawing at the medium end can be ensured, resulting in high-quality drawing.

In other words, the link mechanism (first connecting part 125) connected to the support part 100 moves the hole sealing member 35 in conjunction with the adjustment of the paper holders 34 provided on both outer sides of the drawing medium 2 in accordance with the media width, so that when adjusting the position of the paper holders 34 that seal the air intake holes 32 on the outer side of the drawing medium 2 on the platen 31 to the width of the drawing medium 2, the hole sealing member 35 can also be simultaneously adjusted to the appropriate position.
This eliminates the need to check the position of the hole blocking member 35, which is located inside and difficult to align visually, and reduces the effort required to align the position of the paper holder 34 and the hole blocking member 35 to the width of the drawing medium 2.

In addition, by providing the handle 113 on the support part 100, the position adjustment by the link mechanism (first connection part 125) and the opening and closing operation by the opening and closing mechanism (second connection part 140) can be performed on a single outer fulcrum, so that the opening and closing operation of the paper holder 34 and the movement of the drawing medium 2 in the width direction, which are performed when adjusting the position of the paper holder 34 that blocks the intake hole 32 on the outside of the drawing medium 2 on the platen 31 to the width of the drawing medium 2, can be performed without changing grips of the handle 113, improving work efficiency when replacing the drawing medium 2.

In addition, the paper holder 34 is supported on the support part 100 by a knurled screw 343 and can be easily attached and detached. Therefore, even if the paper holder 34 becomes dirty with fine ink particles from the drawing head 41, the user can remove the paper holder 34 from the printing device 1 in a short time.
This allows the paper holder 34 to be cleaned without any resistance and in a location that is easy to work in.

In the inkjet printer described above, the structures of the drawing head and the drawing head drive device, the structures of the paper holders in the printing section, the types of ink, etc. are not limited to those in the above-described embodiment, and various modifications are possible.
For example, a ball screw structure may be used instead of a steel belt for the power transmission mechanism that moves the head part on which the drawing head is mounted in the front-rear direction of the printing unit. Also, the ink used for drawing is not limited to water-based ink, and UV-curable ink may be used if the ink contacting members including the drawing head are suitable.

REFERENCE SIGNS LIST 1 Printing device 2 Drawing medium 10 Housing 20 Printing base 30 Printing section 31 Platen 32 Air intake hole 34 Paper holder 35 Hole closing member 40 Head 41 Drawing head 100 Support 103 Step bolt 103a Step (shaft)
104: First connecting piece 106: Second connecting piece 107: Spherical bearing 107a: Spherical portion 108: Spherical body 108a: Through hole
109: spherical bearing cover 111: bolt 112: handle connecting portion 113: handle 120: first movable shaft 125: first connecting portion (link mechanism)
130...Second movable shaft 140...Second connection part (opening/closing mechanism)
343: knurled screw 344: stepped piece portion 351: groove portion

Claims (7)

In an inkjet printer that uses a drawing head to draw on drawing media of different widths,
a pair of film-like paper pressers that cover the intake holes located on both outer sides of the drawing medium from above the platen, the intake holes being provided in a platen along which the drawing medium is transported;
a pair of hole closing members that are movable in a width direction of the drawing medium and that are elongated in a transport direction of the drawing medium and that close a part of the air intake hole from below the platen;
a support portion that supports the paper presser so as to allow a position adjustment movement in the width direction;
a link mechanism that adjusts the position of the hole closing member by moving the hole closing member in the width direction in conjunction with the movement of the support part in the width direction,
an inkjet printer comprising: a paper holder and an edge of a drawing medium, the paper holder having a predetermined gap therebetween; and a pair of hole blocking members blocking air intake holes located in the gap from below the platen. The inkjet printer according to claim 1, wherein the support portion has an opening/closing mechanism that is rotatable about an axis aligned with the transport direction. The inkjet printer according to claim 2, wherein the opening and closing mechanism comprises a spherical bearing fixed to the support part and having a spherical portion, and a spherical body that fits into the spherical portion. The inkjet printer according to claim 1, in which stepped portions are provided at intervals in the conveying direction on the inner end of the paper presser. The inkjet printer according to claim 4, wherein a groove is provided in the hole blocking member below the installation portion of the step piece. 3. The inkjet printer according to claim 2 , wherein a handle is provided on the support portion for moving the opening/closing mechanism and for adjusting the position . The inkjet printer according to claim 1, wherein the paper holder is supported on the support by a knurled screw.

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