JP2013023365A - Platen unit and liquid injecting device - Google Patents

Abstract

An object of the present invention is to quickly release a platen charge while properly sucking a medium onto the platen.
A platen main body formed of a resin and having a hole for sucking a medium to be conveyed; a conductive rib mounted on the platen main body for supporting the medium in contact with the medium; and the conductive A platen unit including a charge removal unit that removes charges charged in the rib. It is desirable that the static eliminating unit is a corona discharge ionizer. Further, the static elimination unit may be a grounding member that grounds the conductive rib.
[Selection] Figure 8

Description

  The present invention relates to a platen unit and a liquid ejecting apparatus.

2. Related Art Inkjet printers that use ink to form an image on a medium are used. Such an ink jet printer includes a platen for supporting a medium. The platen appropriately maintains the distance between the head that ejects ink and the medium by appropriately supporting the medium.

Patent Document 1 and Patent Document 2 show a platen for supporting a sheet during printing. Patent Document 3 discloses a large format printer that performs printing on a wide paper sheet.

JP 2010-214880 A JP 2000-289290 A JP 2009-279780 A

When a medium such as paper passes over the platen, static electricity may be generated. In particular, the medium conveyed on the platen is sucked from the platen side in order to keep the distance from the head constant. Thus, since the frictional force between the medium and the platen increases when sucked by the platen,
Static electricity is more likely to occur. The generation of static electricity generates an electric field between the platen and the head. Paper dust may fly from the edge of the paper, but the paper dust is polarized in this electric field and is attracted to the head by the influence of the electric field.

A nozzle for ejecting a liquid such as ink is formed in the head. However, when paper dust is adsorbed by the nozzle, the nozzle is clogged, and there is a problem that the ink is not ejected properly. Therefore, in order not to generate an electric field between the platen and the head, it is desirable to quickly release the static charge generated in the platen.

The present invention has been made in view of such circumstances, and an object of the present invention is to quickly release the charge of the platen while appropriately sucking the medium onto the platen.

The main invention for achieving the above object is:
A platen main body formed of resin and having a hole for sucking a medium to be conveyed;
Conductive ribs mounted on the platen body and supporting the medium in contact with the medium;
A charge removal portion for removing charges charged on the conductive rib;
It is a platen unit provided with.

  Other features of the present invention will become apparent from the description of the present specification and the accompanying drawings.

1 is a perspective view of an inkjet printer 1 in the present embodiment. It is an internal side view of the inkjet printer 1 in this embodiment. It is a perspective view of the platen unit 30 in this embodiment. It is a front view of the 1st platen 31A and the 1st platen base 32A in this embodiment. It is a top view of the platen unit 30 in this embodiment. FIG. 3 is a cross-sectional view of the platen unit 30 along AA. It is a top view of the first platen 31A. 8A is a BB cross-sectional view of the first platen 31A, and FIG. 8B is a BB cross-sectional view of the first platen 31A before assembly. 9A is a first enlarged view of the hook-like member 311 and the protrusion 321 of the platen in the present embodiment, and FIG. 9B is a second enlargement of the hook-like member 311 of the platen and the protrusion 321 in the present embodiment. FIG. It is explanatory drawing of an electric field when platen 31 'is insulated. It is explanatory drawing of an electric field when the platen 31 is earth | grounded.

At least the following matters will become clear from the description of the present specification and the accompanying drawings. That is,
A platen main body formed of resin and having a hole for sucking a medium to be conveyed;
Conductive ribs mounted on the platen body and supporting the medium in contact with the medium;
A charge removal portion for removing charges charged on the conductive rib;
It is a platen unit provided with.
When a hole for sucking a medium is provided in the platen, the platen has a complicated shape. On the other hand, since it is necessary to ensure flatness and to keep the distance from the head constant at the portion where the medium comes into contact, it is necessary to be manufactured precisely. If manufactured by punching a sheet metal or the like, there is a problem that the required accuracy is not satisfied and the number of steps is large. Therefore, such a member is generally formed by injection molding. However, when the resin is manufactured, static electricity generated by friction with the medium or the like accumulates on the platen, and there is a problem that the scrap of the medium polarized by the static electricity adheres to the head. With the above configuration, since the platen main body is formed of resin, a complicated shape including a hole can be formed with high accuracy. You can escape quickly.

In such a platen unit, it is preferable that the charge eliminating portion is a corona discharge ionizer.
By doing in this way, ion can be generated and static electricity can be appropriately neutralized and neutralized.

Further, the static elimination unit may be a grounding member that grounds the conductive rib.
In this way, static electricity can be removed by releasing electric charges.

The platen body is preferably formed by injection molding.
By doing so, the platen body having a complicated shape can be precisely formed by injection molding, while the rib supporting the medium can be made conductive to release electric charges.

Further, the platen body has a flat surface that comes into contact with the medium when the medium is conveyed,
It is desirable that the flat surface and the apex of the conductive rib constitute the same surface.
By doing so, the medium can be supported on the same plane constituted by the plane of the platen main body and the apexes of the ribs.

The conductive rib is preferably fitted through a hole penetrating the platen body from a lower part of the platen body.
By doing in this way, a static elimination part can be arrange | positioned in the lower part of a platen main body, and static electricity can be neutralized via a part of rib extended to the lower part of a platen main body.

The conductive rib is preferably made of metal.
By doing in this way, a charge can be moved quickly and static electricity can be effectively neutralized.

In addition, at least the following matters will become clear from the description of the present specification and the accompanying drawings.
That is,
A head for ejecting liquid onto a medium;
A platen body formed with a resin and having holes for sucking the medium to be conveyed;
Conductive ribs mounted on the platen body and in contact with the medium to support the medium;
A charge removal portion for removing charges charged on the conductive rib;
A liquid ejecting apparatus.

When a hole for sucking a medium is provided in the platen, the platen has a complicated shape. On the other hand, since it is necessary to ensure flatness and to keep the distance from the head constant at the portion where the medium comes into contact, it is necessary to be manufactured precisely. If manufactured by punching a sheet metal or the like, there is a problem that the required accuracy is not satisfied and the number of steps is large. Therefore, such a member is generally formed by injection molding. However, when the resin is manufactured, static electricity generated by friction with the medium or the like accumulates on the platen, and there is a problem that the scrap of the medium polarized by the static electricity adheres to the head. With the above configuration, since the platen main body is formed of resin, a complicated shape including a hole can be formed with high accuracy. On the other hand, since the rib contacting the medium is conductive, the charge is removed by using the charge eliminating portion. You can escape quickly.

=== Embodiment ===
FIG. 1 is a perspective view of an ink jet printer 1 in the present embodiment. As shown in the figure, the ink jet printer 1 is mounted on the recording unit 40 with the longitudinal direction horizontally arranged, a casing 90 mounted on the end of the recording unit 40, and an upper side of the recording unit 40. Loading unit 10
And leg portions 70 that support the recording unit 40 and the housing 90 from below.

Inside the loading unit 10, a roll assembly 11 including a roll R on which a long recording medium (refer to FIG. 2; hereinafter, also referred to as “medium”) is wound is loaded. Solid 11
(See FIG. 2) is covered with a roll cover 12. The recording unit 40 has its internal mechanism covered with a top cover 42 and a front cover 44. A head 41 (see FIG. 2), which will be described later, is disposed inside the recording unit 40, and ink is ejected onto the medium drawn from the roll R of the loading unit 10 and fed to the recording unit 40. Is formed.

The medium on which the image is formed in the recording unit 40 is the discharge unit 6 formed below the recording unit 40.
It is discharged from 0 to the outside. The leg portion 70 is attached for the purpose of preventing the medium that has passed through the discharge portion 60 from coming into contact with the floor surface.

The housing 90 forms a home position space where the head retracted from the recording unit 40 stands by, and has a cartridge holder 20 at the lower portion thereof. Cartridge holder 2
In 0, an ink cartridge (not shown) containing ink to be supplied to the head is mounted inside the holder cover 22 that covers the surface.

An operation panel 80 is disposed on the upper surface of the housing 90. In addition to the plurality of switches 82 operated by the user, the operation panel 80 also includes a display unit 84 that indicates the operation state of the ink jet recording apparatus 1. Accordingly, the user operates the inkjet printer 1 from the front side with the side on which the operation panel 80 and the cartridge holder 20 are disposed as the front side.

FIG. 2 is an internal side view of the inkjet printer 1 in the present embodiment.
As shown in FIG. 2, the inkjet printer 1 includes a spindle 1 that holds a roll R.
3, a conveyance path 14 that conveys the roll paper R, a recording unit 40 that performs image formation on the conveyed medium, a discharge unit 60 that discharges the medium that has undergone image formation, and discharge from the discharge unit 60 And a cutter device 61 for shearing the medium to be processed. Inkjet printer 1
Is a platen unit 30 that supports a medium being conveyed at a lower portion of a head 41 to be described later.
Is provided. The platen unit 30 includes a platen 31, a platen base 32, and a support member 33. The detailed configuration of the platen unit 30 will be described later. Further, the ink jet printer 1 includes a control unit (not shown) that comprehensively controls the operation of each component device.

In the following description, the medium transport direction (discharge direction) is the X-axis direction, the width direction of the transport path 14 perpendicular to the X-axis direction (the direction perpendicular to the paper surface in FIG. 2) is the Y-axis direction, and the X-axis direction. The vertical direction perpendicular to the Y-axis direction is sometimes referred to as the Z-axis direction.

The recording unit 40 includes a head 41 that ejects ink onto a medium conveyed along the conveyance path 14. The head 41 is mounted on a carriage 43 that is movable in the width direction of the transport path 14. The head 41 includes a plurality of nozzle rows, and is configured to eject ink of a predetermined color (for example, yellow (Y), magenta (M), cyan (C), and black (K)) from each nozzle row. ing. The head 41 performs image formation for recording information such as a predetermined image and characters by ejecting ink onto the recording surface of the roll paper R supported by the platen 31.

The medium on which the image is formed by the recording unit 40 is a nip portion 5 that constitutes a terminal portion of the conveyance path 14.
0 is discharged from the discharge unit 60. The nip portion 50 includes a plurality of discharge rollers 51 that nip and rotate the medium to discharge the medium. The discharge roller 51 includes a mechanism for switching a roller for nipping depending on the paper type to a jagged roller 51a or a roller roller 51b.

On the downstream side of the nip portion 50, a cutter device 6 that shears the discharged medium to a predetermined size.
1 is provided. The cutter device 61 includes a regulating member 62 that regulates the height position of the discharged medium, and a cutter unit that moves in the width direction (Y-axis direction) orthogonal to the medium discharge direction (X-axis direction) to shear the medium. 63.

FIG. 3 is a perspective view of the platen unit 30 in the present embodiment. FIG. 3 shows a platen 31, a platen base 32, and a support member 33 as a minimum configuration constituting the platen unit 30 of the present embodiment. FIG. 3 is a perspective view of a part of the platen unit 30 in order to facilitate the description of the configuration of the platen unit 30.

FIG. 4 is a front view of the first platen 31A and the first platen base 32A in the present embodiment. The platen 31 and the platen base 32 are each composed of a plurality of members. Of these, the first platen 31A and the first platen base 32A are shown. 4 is a view when the first platen 31A and the first platen base 32A are viewed from the X-axis plus side to the minus side in FIG. 2, but this angle when attached to the inkjet printer 1 is shown. Cannot be seen from. here,
For the sake of explanation, these are shown in a state of being taken out from the inkjet printer 1.

Hereinafter, the outline of the platen unit 30 will be described with reference to these drawings. The support member 33 is a member for supporting the platen base 32 at the upper part thereof. The platen base 32 includes a first platen base 32A, a second platen base 32B, and a third platen base 32C (not shown in FIG. 3).

Although these platen bases have different lengths in the paper width direction (Y direction), the other configurations have substantially the same configuration, and therefore, here, the first platen base 32A will be mainly described as an example. I do. Also, the first platen base 32A and the second platen base 32B
The first platen 31A, the second platen 31B, and the third platen 31C are provided on the top of the third platen base 32C. The first platen 31A, the second platen 31B, and the third platen 31C also have different lengths in the paper width direction (Y direction), but the other configurations have almost the same configuration. The first platen 31A will be described as an example.

A platen main body 318 (described later) and a platen base 32 of the platen 31 are both injection-molded with a resin such as plastic. The reason why the air discharge resin was not used is that the air discharge resin is easily worn, and it is not possible to ensure the high accuracy of the platen over a long period of time.

Also, the reason why the platen body 318 was not manufactured with a sheet metal material is that the shape of the platen main body 318 is relatively complicated. This is because it is difficult.

The bottom portion of the first platen base 32A includes a plurality of bottom opening portions 322. As shown in FIG. 4, the bottom opening 322 protrudes from the bottom surface of the platen base 32 </ b> A, and the support member 3.
3 (to be described later). The internal space of the first platen base 32A communicates with the internal space of the support member 33. Similarly, the other platen bases also have a bottom opening 322 communicating with the support member 33. Therefore, the internal space of the first platen base 32A, the internal space of the second platen base 32B, and the internal space of the third platen base 32C are The air is movably communicated.

The first platen 31A is fitted into a part of the upper portion of the first platen base 32A by sliding in the Y axis plus direction. Although not shown in FIG. 3, the second platen 32B is also fitted adjacent to the first platen 31A. Thereby, at least a part of the first platen 31A is provided on the first platen base 32A, and the second platen 31B is provided on the first platen base 32A and the second platen base 32B. Then, adjacent first platens 31 on the first platen base 32A.
The height of the end of A and the end of the second platen 31B can be made uniform.

In particular, since the large-sized inkjet printer 1 as shown in FIG. 1 is long in the paper width direction,
A platen unit is configured by using a platen unit with a plurality of platen bases and a plurality of platens as described above. However, when a platen unit is constituted by a plurality of platens, if there is a step between them, there is also a problem that the medium to be conveyed floats at that location. Further, if a step is generated, air leaks there, and there is a possibility that the medium is not properly sucked in the platen. This becomes an obstacle to the conveyance of roll paper that is frequently used particularly in the large-format ink jet printer 1. However, with the configuration of the present embodiment as described above, the height of the end of the first platen 31A and the end of the second platen 31B can be made uniform, so that no step is generated between them. can do.

The first platen 31A is provided with a support surface 312 for supporting the medium to be transported and a groove 313 for preventing liquid such as discarded ink from coming into contact with the medium being transported. The groove portion is provided with a first suction hole 314 that serves both as ink suction and medium suction. The first suction hole 314 penetrates from the upper part of the first platen 31A to the lower part (Z-axis direction). The first
In the platen 31A, the second suction hole 315 and the third suction hole 315 are formed in the support surface 312 that supports the medium to be conveyed.
A plurality of suction holes 316 are provided.

A stretched and continuous sponge 34A is provided around the upper edge of the first platen base 32A. The sponge 34A may be impregnated with glycerin. Thus, when impregnating liquids, such as glycerin, the airtightness between a platen and a platen base can be improved more.

The first platen base 32A has a protrusion 321 protruding in the medium transport direction (X-axis direction).
(Of course, the protrusions 321 are also provided on the opposite side (X-axis minus direction) of the medium conveyance direction). The first platen 31A is provided with a plurality of hook-like members 311 for engaging with the protrusions 321. These hook-shaped members 311 are provided so as to straddle the sponge 34A of the first platen base 32A in the X-axis direction when the first platen 31A is attached to the first platen base 32A. That is, it is provided so as to protrude outside the first platen base 32A. Hook-like member 311 and protrusion 321
Are provided at the same pitch in the paper width direction, and the plurality of hook-shaped members 311 engage with the corresponding protrusions 321 respectively.

A plurality of contact portions 325 are provided at the bottom of the first platen base 32 </ b> A so as to contact the support member 33. The center of some of the contact portions 325 of the plurality of contact portions 325 is perforated, and the first platen base 32A is fixed to the support member with a fastening member such as a screw through the perforation holes. Further, these contact portions 325 are provided in the protruding portion 3 in the paper width direction (Y-axis direction).
21 is provided at a position where a contact surface (contact portion) of the contact surface (described later) 21 and a contact surface of the hook-shaped member 311 are in contact with each other. By doing so, the distance between the contact portion 325 and the contact surface can be reduced, and the height from the platen to the support member can be more accurately guaranteed.

FIG. 5 is a top view of the platen unit 30 in the present embodiment. FIG. 6 is a cross-sectional view of the platen unit 30 taken along the line AA. FIG. 5 shows that the platen 31 includes a first platen 31A, a second platen 31B, and a third platen 31C. It is also shown that the lengths of these platens in the paper width direction are different from each other. However, the number of platens for constituting the platen unit is not limited to this. Further, the length of the platen in the paper width direction is not limited to this.

In FIG. 6, a first platen base 32A, a second platen base 32B, and a third platen base 32C are provided on the support member 33, and further, a first platen 31A, a second platen 31B, and a third platen are provided thereon. It is shown that a platen 31C is provided.

The first platen base 32A, the second platen base 32B, and the third platen base 32C are fitted into the opening 332 of the support member 33 through the bottom opening 322. The lengths of the first platen base 32A, the second platen base 32B, and the third platen base 32C in the paper width direction (Y-axis direction) are different.

A suction device 38 is provided at the center bottom of the support member 30. The suction device 38 keeps the air pressure in the internal space lower than the external air pressure by discharging the air in the internal space formed by the platen 31, the platen base 32, and the support member 33 to the outside of the platen unit 30. As a result, the medium conveyed on the platen 31 becomes the first suction hole 314 and the second suction hole 31 described above.
5. Adsorbed to the platen through the third suction hole 316. By doing so, the medium is adsorbed on the flat platen, so that the flat surface of the medium is secured. Then, ink droplets can be ejected onto the medium maintained flat. For this reason, since the distance between the head and the medium can be kept uniform in the paper width direction and the transport direction, ink droplets can be landed at desired positions to provide a printed matter with good image quality.

As described above, around the upper edge of the first platen base 32A, a stretched and continuous sponge 3 is provided.
4A is provided. Similarly, a stretched and continuous sponge 34B is also provided around the upper edge of the second platen base 32B, and a stretched and continuous sponge 34C is also provided around the upper edge of the third platen base 32C. These sponges have a hook-shaped member 311 having a protrusion 3.
When the platen is fixed by engaging with 21, it is compressed in the vertical direction (Z-axis direction). That is, since the sponge is deformed and adheres closely to the platen base and the platen, the airtightness between the platen base and the platen can be improved.

In the figure, a plurality of rib members 319 are shown. In this embodiment, five rib members are used, and reference numerals 319-1 to 319-5 are attached to the respective rib members. The positional relationship of the rib member 319 on the platen will be described later.

Moreover, the figure shows a corona discharge ionizer (corresponding to a charge eliminating portion). The corona discharge ionizer includes a high-voltage power source 371, an electrode needle 372, and a connection line connecting them. In the drawing, the connection line connecting the high voltage power supply 371 and the electrode needle 372 is indicated by a broken line. The electrode needle is provided at substantially the center of the lower portion of each rib member.

A high voltage of 3 kV or higher is applied to the electrode needle from a high voltage power source. Then, corona discharge is generated from the tip of the electrode needle 372. By corona discharge, the air around the electrode needle 372 is electrically decomposed to generate ions. By applying these ions to the rib member 319 which is a charged substance, static electricity is neutralized and static elimination is performed.

Here, the corona discharge ionizer is used as a device for eliminating static electricity, but the rib member 319 may be simply grounded. In this case, a conductive material that is connected to the rib member 319 and used for grounding corresponds to the charge removal portion.

FIG. 7 is a top view of the first platen 31A. FIG. 7 shows a platen main body 318 and a rib member 319 constituting the first platen 31A. Moreover, the position of the BB cross section shown by FIG. 8A and FIG. 8B after that is shown. The platen main body 318 is made of resin and is formed by injection molding. On the other hand, the rib member 319 is made of metal.

8A is a cross-sectional view taken along the line BB of the first platen 31A, and FIG. 8B is a cross-sectional view taken along the line BB of the first platen 31A before assembly. In these drawings, the platen body 318 and the rib member 31 are also shown.
9 is shown. A hook-like member 311 is also shown.

In these drawings, the cut surfaces of the platen main body 318 and the rib member 319 are indicated by hatching. The platen main body 318 is provided with a hole 3182 into which the rib member 319 is fitted.

Further, in the figure, a plane 3181 formed by the platen main body 318 and the apex 319 of the rib member 319
1 is shown. The apex 3191 is adjusted to a height at which the same plane can be formed with the plane 3181 when the rib member 319 is fitted into the platen main body 318. Also, vertex 31
91 is also a flat surface.

The rib member 319 is fitted through the hole 3182 from below the platen main body 318. The platen main body 318 gripping member 319 may be affixed with an adhesive or may be fixed using a fastening member such as a screw so that the two do not deviate from each other.

As described above, the rib member 319 is made of metal, and as shown in FIG. 6, static electricity is eliminated by a corona discharge ionizer. Thereby, even if static electricity is generated by the platen and the medium, the charges can be neutralized via the rib member 319 using the corona discharge ionizer 37.

9A is a first enlarged view of the hook-shaped member 311 and the protrusion 321 of the platen 31 in the present embodiment, and FIG. 9B is a second enlarged view of the hook-shaped member 311 and the protrusion 321 of the platen 31 in the present embodiment. FIG. Here, the engagement between the hook-shaped member 311 and the protrusion 321 will be described with reference to FIGS. 9A and 9B.

9A and 9B show a protrusion 321 and a contact surface 3211 of the protrusion 321. In these figures, the tip 3111 of the hook-shaped member 311 and the tip 311 thereof are shown.
1 shows a triangular elastic protrusion 3112 provided on 1. In addition, these figures include
A contact surface 3113 of the hook-like member 311 that contacts the contact surface 3211 of the protrusion 321 is shown. The normal line of the contact surface 3211 of the protrusion 321 matches the normal line of the support surface 312. Further, the normal line of the contact surface 3113 of the hook-shaped member 311 also coincides with the normal line of the support surface 312.

Each platen is slid in the paper width direction (Y-axis plus direction) on the platen base 32, so that the hook-like member 311 of the platen 32 is the protrusion 32 of the platen base 32.
1 is engaged. When the protrusion 321 is fitted into the hook-shaped member 311, the triangular elastic protrusion 3112 is elastically deformed. Due to the pressing force due to this elastic deformation, the abutment surface 32 of the protrusion 321.
11 is reliably pressed against the contact surface 3113 of the hook-shaped member 311.

Thus, the contact surface 3211 of the protrusion 321 and the contact surface 311 of the hook-shaped member 311
3 is securely in contact with the platen base 32 from the contact portion 325 of the platen base 32.
The height of one support surface 312 is guaranteed to be the designed height. In particular, the contact surface 32 of the protrusion 321.
11 and the normal line of the contact surface 3113 of the hook-shaped member 311 coincide with the normal line of the support surface 312, by making these contact surfaces 3113 and 3211 contact each other with the above-described configuration reliably, The plane of the support surface 312 through which the medium passes can be guaranteed.

Further, since a plurality of hook-like members 311 and protrusions 321 are provided in the paper width direction, the height of the support surface 312 of the platen 31 from the contact portion 325 of the platen base 32 is made uniform over the entire area in the paper width direction. Can do.

FIG. 10 is an explanatory diagram of an electric field when the platen 31 ′ is insulated. In the figure, the platen 31 ′ and the nozzle plate NP ′ of the head 41 ′ are shown. A sheet S is shown as a medium conveyed on the platen.

The head 41 'has the same potential as that of the main body via cables and is grounded.
Therefore, the potential of the nozzle plate NP ′ is zero. On the other hand, when the platen 31 ′ is not grounded, when the paper S passes over the platen 31 ′, static electricity is generated due to friction generated between the platen 31 ′ and the paper S.

In particular, in the large-sized inkjet printer 1 as in the present embodiment, the wide paper S is mainly conveyed in the paper width direction. Further, in order to prevent the sheet S from floating from the platen 31 ′, the sheet S is sucked from the first suction hole 314 to the third suction hole 316 described above. Therefore, the frictional force between the sheet S and the platen 31 ′ is large, and the static electricity generated on the platen 31 ′ is also large. In this way, if the platen 31 ′ is charged and thus the charge removal is not performed, a potential difference is generated between the head 41 ′ and the nozzle plate NP ′, and an electric field is generated.

On the other hand, when the paper S passes, paper dust flies mainly from the end of the paper S. When this paper dust moves between electric fields, the individual paper dust is dielectrically polarized as shown in the figure. The dielectrically polarized paper powder is adsorbed to the platen 31 ′ or the nozzle plate NP ′.

The nozzle plate NP ′ is provided with nozzles (not shown), and ink is ejected from these nozzles. However, when paper dust is adsorbed on the nozzle plate NP ′, the paper dust causes nozzle clogging. Then, the nozzle which cannot eject ink occurs,
A desired dot is not formed in a pixel in which the nozzle is in charge of dot formation (so-called dot omission occurs).

Nozzle cleaning is performed so that such dot omission does not occur. However, since cleaning is performed by forcibly ejecting ink from the nozzle, ink is wasted. In addition, there is a disadvantage that the amount of discharged waste liquid increases due to the forced ejection of ink. Therefore, it is desirable to prevent paper dust from adhering to the nozzle plate NP ′.

FIG. 11 is an explanatory diagram of an electric field when the platen 31 is grounded. In consideration of the paper dust adhesion process as described above, it is desirable to suppress the charging of the platen 31. Therefore, the platen 31 in the present embodiment is neutralized by the conductive rib member 319 and the corona discharge ionizer with the above-described configuration (the electrode needle 372 of the corona discharge ionizer is shown in the figure). .

Thereby, since an electric field is not generated between the nozzle plate NP and the platen 31 of the head 41, paper dust is hardly adsorbed to the nozzle plate NP. Thus, it is possible to provide the ink jet printer 1 in which dot dropout hardly occurs.

=== Other Embodiments ===
In the above-described embodiment, the printer 1 has been described as the liquid ejecting apparatus. However, the present invention is not limited to this, but other fluids other than ink (liquids, liquids in which particles of functional materials are dispersed, gels) Such a fluid can also be embodied in a liquid ejection device that ejects or ejects the fluid. For example, color filter manufacturing apparatus, dyeing apparatus, fine processing apparatus, semiconductor manufacturing apparatus, surface processing apparatus, three-dimensional modeling machine, gas vaporizer, organic EL manufacturing apparatus (especially polymer EL manufacturing apparatus), display manufacturing apparatus, film formation You may apply the technique similar to the above-mentioned embodiment to the various apparatuses which applied inkjet technology, such as an apparatus and a DNA chip manufacturing apparatus. Also,
These methods and manufacturing methods are also within the scope of application.

The above-described embodiments are for facilitating the understanding of the present invention, and are not intended to limit the present invention. The present invention can be changed and improved without departing from the gist thereof, and it is needless to say that the present invention includes equivalents thereof.

<About the head>
The method of ejecting ink is not limited to the method of ejecting using a piezoelectric element, and other methods such as a method of generating bubbles in the nozzle by heat may be used.

1 Inkjet printer,
10 loading section, 11 roll assembly, 12 roll cover, 13 spindle,
14 Transport path,
20 cartridge holder, 22 holder cover,
30 platen units, 31 platens,
31A 1st platen, 31B 2nd platen, 31C 3rd platen,
32A first platen base, 32B second platen base,
32C 3rd platen base,
33 support member,
34A sponge, 34B sponge, 34C sponge,
38 suction device,
40 recording unit, 41 head, 42 top cover,
43 Carriage, 44 Front cover,
50 discharge section, 51 discharge roller, 51a jagged roller, 51b roller roller,
60 discharge section, 61 cutter device, 62 regulating member, 63 cutter unit,
70 legs,
80 operation panel, 82 switch, 84 display section,
90 housing,
311 hook-shaped member, 312 support surface, 313 groove,
314 first suction hole, 315 second suction hole, 316 third suction hole,
318 Platen body, 319 Rib member 321 Projection, 322 Bottom opening, 325 degree contact,
371 high voltage power supply, 372 electrode needle,
3111 Tip portion of hook-shaped member, 3112 elastic protrusion,
3113 contact surface of the platen, 3211 contact surface of the protrusion,
3181 plane, 3191 vertex,
NP nozzle plate,
S paper

Claims (8)

A platen main body formed of resin and having a hole for sucking a medium to be conveyed;
Conductive ribs mounted on the platen body and supporting the medium in contact with the medium;
A charge removal portion for removing charges charged on the conductive rib;
A platen unit with   The platen unit according to claim 1, wherein the static elimination unit is a corona discharge ionizer. The platen unit according to claim 1, wherein the static elimination unit is a grounding member that grounds the conductive rib. The platen unit according to claim 1, wherein the platen body is formed by injection molding. The platen main body has a plane that comes into contact with the medium when the medium is transported, and the plane and the apex of the conductive rib constitute the same plane. The platen unit described in 1. The platen unit according to claim 1, wherein the conductive rib is fitted from a lower part of the platen body through a hole penetrating the platen body. The platen unit according to claim 1, wherein the conductive rib is made of metal. A head for ejecting liquid onto a medium;
A platen body formed with a resin and having holes for sucking the medium to be conveyed;
Conductive ribs mounted on the platen body and in contact with the medium to support the medium;
A charge removal portion for removing charges charged on the conductive rib;
A liquid ejecting apparatus comprising:

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