JP2003159841A - Ink jet printer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent air from flowing through suction holes regardless of the width of a print medium. <P>SOLUTION: Check valves 18 made of a planar nonventilative member having resiliency are provided in all suction holes 15 made in a suction plate 13 such that the suction holes 15 are closed automatically when the air is sucked from the upper end toward the lower end of the suction hole 15 by means of a suction fan 14 to generate an air flow in the suction hole 15. When a sheet 2 is sucked to the surface of the suction plate 13, suction holes 15 only in a region where the sheet 2 does not touch the suction plate 13 are thereby closed by the check valves 18. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet printer for printing an image on a print medium by an ink jet method.

[0002]

2. Description of the Related Art Ink jet printers print by spraying liquid ink onto paper, and have the advantage that the apparatus can be downsized and high quality printing can be performed. 2. Description of the Related Art As an inkjet printer, there is known a printer that prints an image on a sheet being conveyed by ejecting ink from a print head that reciprocates along a direction perpendicular to the sheet conveying direction. In particular, when roll paper is used as the paper, the suction method is often used to ensure the flatness of the printing surface of the paper.

Here, in the suction type ink jet printer, a suction plate, which has substantially the same height as a sheet conveying surface which is arranged to face a print head and has a large number of suction holes, and a suction plate. Some have a suction fan for sucking a sheet onto the surface of the suction plate through the suction holes of the plate. In such an ink jet printer, the paper facing the print head is in close contact with the surface of the suction plate, so that the flatness of the printing surface of the paper can be ensured. Therefore, it is possible to prevent deterioration of the image printed on the paper due to the fact that the flatness of the printing surface of the paper is not ensured. It should be noted that the suction plate is formed with suction holes over its entire width so that the flatness of the printing surface of the paper can be ensured even when printing is performed on a paper having a width substantially the same as the width of the suction plate. Many.

[0004]

However, in an ink jet type printer having a suction plate in which suction holes are formed over the entire width thereof, when printing is performed on a paper having a relatively narrow width, a large number of suction plates are used. The suction holes corresponding to the inner portions of the both ends of the paper in the width direction are closed by the contact of the paper, but the suction holes corresponding to the portions protruding from the both ends of the paper in the width direction do not adhere to the paper. So it is not blocked. Therefore, a large amount of air flows from the suction holes that are not blocked from the front surface (on the print head side) of the suction plate toward the back surface of the suction plate where the suction fan is arranged.

In such a case, the ink mist generated during printing and the ink mist generated during the flushing operation of the print head for eliminating the clogging of the discharge nozzles arranged in the print head are the above-mentioned air. Flow adheres to the surface of the suction plate, so that the back surface of the sheet conveyed on the suction plate becomes dirty. In addition, due to the above-mentioned air flow, the ink mist sucked into the back surface of the suction plate may cause a malfunction of the suction fan, or the ink mist may be diffused into the printer cabinet, resulting in a malfunction of electrical components. May cause. Further, in consideration of the amount of air sucked from the suction holes that are not blocked when printing is performed on a sheet having a relatively narrow width, it is necessary to use a larger suction fan than necessary, which increases the cost of parts. Various problems such as power consumption increase, heat generation and noise increase will occur.

[0006] Therefore, a main object of the present invention is to provide an ink jet printer which can prevent air from flowing through the suction holes regardless of the width of the print medium.

[0007]

In order to achieve the above object, an ink jet printer according to a first aspect of the present invention is an ink jet printer which conveys a print medium and ink jets the print medium conveyed by the convey means. An ink ejecting section that ejects ink by a method, an auxiliary member that has substantially the same height as a conveyance surface of a print medium that is arranged to face the ink ejecting section, and has at least one suction hole formed therein; Adsorption means for adsorbing the print medium to the surface of the auxiliary member through the adsorption hole of the member, and an area where the print medium of the auxiliary member contacts when the print medium is adsorbed on the surface of the auxiliary member. The corresponding suction holes are not closed, and a closing means for closing the suction holes corresponding to the area of the auxiliary member that does not come into contact with the print medium is provided.

According to the first aspect of the present invention, when the print medium is adsorbed on the surface of the auxiliary member, the closing means closes only the suction hole corresponding to the area of the auxiliary member which is not in contact with the print member. It is possible to prevent air from flowing in from the suction holes corresponding to the regions of the auxiliary member that are not in contact with the print medium while ensuring the flatness of the printing surface of the print medium by bringing the medium into close contact with the surface of the auxiliary member. Therefore, it is possible to prevent the print medium from being contaminated due to the ink mist or the like generated during printing adhering to the surface of the auxiliary member. Further, it is possible to prevent the ink mist from being sucked into the back surface side of the auxiliary member to cause a failure of electric parts such as the suction means. Further, in consideration of the amount of air sucked from the suction holes that are not blocked by the auxiliary member, it is not necessary to use a larger suction means than necessary, so that the size of the printer is increased, the cost of parts is increased, the power consumption is increased, heat generation and noise are increased. It is possible to suppress the occurrence of problems such as increase in

Here, "a suction hole corresponding to a region of the auxiliary member where the print medium comes into contact" means a suction hole that is closed when the print medium comes into close contact, and "the print medium of the auxiliary member comes into contact with the suction hole". The "suction hole corresponding to the non-use area" refers to a suction hole that is not blocked by the print medium.

According to a second aspect of the present invention, in the ink jet printer, the closing means has an elastically operable closing mechanism provided in each of the suction holes of the auxiliary member, and the printing medium is the auxiliary medium. When adsorbed on the surface of the member, one or more non-air-permeable members included in the closing mechanism provided in the adsorption hole corresponding to a region of the auxiliary member that does not come into contact with the print medium are generated by the adsorption unit. It is characterized in that it is configured to close the adsorption holes by being moved by the flow of air that is made to flow.

According to the second aspect, the non-air-permeable member included in the closing mechanism provided in the suction hole corresponding to the area of the auxiliary member which does not come into contact with the print medium is automatically operated by the flow of air generated by the suction means. In addition, since the suction holes are closed, a separate device for moving the non-air-permeable member is not required. Therefore, the structure of the ink jet printer can be simplified and the manufacturing cost can be prevented from increasing. Further, since the suction holes corresponding to the regions of the auxiliary member that are not in contact with the print medium are closed by the non-air-permeable member, air does not flow from the suction holes corresponding to the regions of the auxiliary member that are not in contact with the print medium.

The ink jet printer according to a third aspect of the invention is characterized in that the closing mechanism is composed of one plate-like non-air-permeable member having elasticity. According to the third aspect, since the non-breathable member included in the closing mechanism is a plate-like member having elasticity, it is not necessary to provide a separate mechanism for elastically operating the non-breathable member. Therefore, the structure of the closing mechanism can be simplified.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a diagram showing a schematic configuration of an inkjet printer according to an embodiment of the present invention. FIG. 2 is a diagram showing a schematic configuration in the vicinity of the inkjet printing unit of the inkjet printer of FIG. FIG. 3 is a diagram for explaining the operation of the check valve arranged in the suction hole. FIG. 4 is a sectional view taken along line IV-IV in FIG. FIG. 5: is a figure which shows the other example of a structure of a check valve.

The ink jet printer 1 shown in FIG.
Is a substantially rectangular parallelepiped casing 30 in which the transport roller unit 5 is
The inkjet printing unit 6, the pressure bonding roller unit 7, the cutting unit 8, and the discharge roller unit 9 are provided. A long paper 2 having a winding portion 2a wound in a roll shape is arranged in the housing 30, and the winding portion 2a of the paper 2 is rotatable around an axis center. It is held on the drum 3. Further, as will be described later, the operation of each part of the inkjet printer 1 is controlled by the controller 20 arranged in the housing 30.

The transport roller unit 5 includes a controller 2
A pair of driving rollers driven by a motor 21 controlled by 0, for unwinding the paper 2 from the winding unit 2a and supplying it to the inkjet printing unit 6.

The ink jet printing unit 6 includes a print head 11 and a carriage 12 that holds the print head 11.
And a suction plate 13 and a suction fan 14. The print head 11 includes a large number of ejection nozzles (not shown) capable of ejecting color inks such as yellow (yellow), magenta (magenta), cyan (blue-green), and black. Therefore, the print head 11 ejects color inks from a large number of ejection nozzles toward the front surface (the upper surface in FIG. 1) of the conveyed paper 2 based on a signal from the controller 20, thereby obtaining a desired color. Images can be printed. The number and arrangement of the discharge nozzles can be changed arbitrarily. The print head 11 may have a discharge nozzle that discharges only black ink, and may print a black and white image.

The ink jet printing unit 6 is
Liquid ink is ejected from the nozzles dot by dot to print on the paper 2, and any of a piezo jet system, a thermal jet system, or any other system may be adopted.

The carriage 12 is capable of reciprocating together with the print head 11 in a direction perpendicular to the paper 2 conveyance direction.
Therefore, the print head 11 ejects ink toward the surface of the paper 2 while reciprocating in the direction perpendicular to the transport direction of the paper 2.

The suction plate 13 is, as shown in FIG.
It has a paper support surface at the same height as the transport surface of paper 2,
It is for supporting the paper 2 arranged to face the print head 11. A large number of circular suction holes 15 are formed in the suction plate 13 over the entire width thereof. The number, shape, and arrangement of the suction holes 15 can be changed arbitrarily. Here, the width direction center position of the paper 2 coincides with the width direction center position of the suction plate 13 (center alignment with the suction plate 13).
Be transported.

Here, as shown in FIG. 3, the suction holes 15 formed in the suction plate 13 have a large-diameter void portion 15a arranged on the surface side (conveying surface side) of the suction plate 13,
Small-diameter void 1 arranged on the back side of the suction plate 13
5b and. Therefore, the step portion 16 is provided at the boundary portion between the void portion 15a and the void portion 15b in the suction hole 15.
Is formed. Then, on the step portion 16 in the suction hole 15, the check valve 1 made of elastic resin, rubber or the like is provided.
8 are provided.

The check valve 18 includes a fixed portion 18a and a fixed portion 1
It is a plate-shaped member having a substantially V shape when viewed from the side surface, which is composed of a movable portion 18b extending from 8a, and a rectangle when viewed from the top surface. That is, the fixed portion 18a and the movable portion 18b are formed to have a predetermined angle (for example, an angle of 150 degrees). The check valve 18 is a non-air-permeable member formed of a material having elasticity. The fixed portion 18a is fixed on the step portion 16 such that the boundary portion with the movable portion 18b is arranged near the upper end portion of the void 15b. Further, the movable portion 18b is sufficiently larger than the size of the void 15b, and is arranged obliquely upward so as to cover the void 15b.

Here, the check valve 18 is, as described above,
The movable part 1 is formed of an elastic material.
8b can swing with the boundary portion with the fixed portion 18a as a fulcrum. That is, the movable portion 18b has the space 15b.
3 (a position having a predetermined angle with the fixed portion 18a: see FIG. 3 (a)) and a position for closing the gap 15b (position arranged on the same plane as the fixed portion 18a: FIG. 3).
(See (c)).

The suction fan 14 is arranged at a position facing the print head 11 with the conveyance path of the sheet 2 interposed therebetween.
This is for adsorbing the sheet 2 on the adsorption plate 13 through the adsorption holes 15 formed in the adsorption plate 13. Therefore, the paper 2 facing the print head 11 is the suction fan 1 arranged on the back surface (lower surface in FIG. 1) side of the paper 2.
By being sucked by 4, the sheet is closely attached to the suction plate 13 and conveyed, and the interval between the print head 11 and the print head 11 becomes constant. This is when the paper 2 is curled,
This is because a part of the paper 2 is largely separated from the suction plate 13 to prevent a printing defect due to a change in the distance from the print head 11.

The pressure roller unit 7 holds the sheet 2 conveyed between the ink jet printing unit 6 and the cutting unit 8. By disposing the pressure roller unit 7 between the inkjet printing unit 6 and the cutting unit 8, the inkjet printing unit 6 prints and cuts an image.
It is possible to properly cut the sheet 2 by

The cutting unit 8 has a moving blade 8 arranged on the same side of the paper 2 as the ink jet printing unit 6.
It has a and a fixed blade 8b arranged so as to face the movable blade 8a with the sheet 2 in between. Both the movable blade 8a and the fixed blade 8b are rectangular blades having a width slightly larger than the width of the paper 2. The movable blade 8a is a controller 20.
By the motor 22 controlled by the above, the printed sheet 2 that has been conveyed from the upstream side of the conveyance path can be moved toward and away from the fixed blade 8b. It is possible to cut along the width direction by the action. By cutting in this way, the printed paper 2 is divided into a predetermined length.

The discharge roller unit 9 is the controller 2
It is a drive roller pair driven by a motor 23 controlled by 0, and conveys the printed paper 2 cut by the cutting unit 8 and discharges it from the discharge port 30a.

The controller 20 also performs a predetermined process on the image signal supplied from an input interface (not shown) and supplies a print signal containing image data corresponding to the image to be printed to the ink jet printing unit 6. Further, the controller 20 uses the motors 21, 22, 2
The drive signal is supplied to 3.

Next, the operation of the check valve 18 included in the ink jet printer 1 according to this embodiment will be described with reference to FIGS. 3 and 4.

First, in the initial state where printing is not performed (when the suction fan 14 is stopped), as shown in FIG.
The movable portion 18b of the check valve 18 is arranged at a position where the gap 15b is opened. Then, when the operation of the adsorption fan 14 is started, as shown in FIG. 3B, air is sucked from the upper end portion to the lower end portion of the adsorption hole 15 to be generated in the adsorption hole 15. Due to the flow of air (indicated by a dotted arrow in FIG. 3 (b)), the movable portion 18 b moves toward a position that closes the gap 15 b with the boundary portion with the fixed portion 18 a as a fulcrum (FIG. 3).
In (b), it begins to rock (in the direction of the solid arrow). Thereafter, as shown in FIG. 3C, the movable portion 18b swings to a position that closes the gap 15b, and is held at a position that closes the gap 15b until the operation of the suction fan 14 is stopped. .

That is, while the adsorption fan 14 is operating, the negative pressure generated by the adsorption fan 14 pulls the movable portion 18b from the position where the gap 15b is opened toward the position where the gap 15b is closed. For,
After moving to a position that closes the gap 15b, it is held at that position. On the other hand, when the suction fan 14 is stopped, the negative pressure generated by the suction fan 14 is released, so that the movable portion 18b closes the gap 15b by the elastic force of the material forming the check valve 18. Void from position 15
It is urged toward the position for opening b, and moves to the position for opening the void 15b in the initial state.

Here, the check valve 1 provided in the suction hole 15 corresponding to the area of the suction plate 13 where the paper 2 does not come into contact.
As described above, 8 can close the suction holes 15 or open the suction holes 15 in accordance with the operation and stop of the suction fan 14. Since the check valve 18 is a non-air-permeable member as described above, the suction holes 15 corresponding to the regions of the suction plate 13 that the paper 2 does not contact.
However, when the check valve 18 closes the suction hole 15
No air will flow in from.

On the other hand, as shown in FIG. 3D, the suction hole 15 corresponding to the area of the suction plate 13 where the paper 2 comes into contact, the paper 2 is in close contact with the upper end of the (gap 15a) of the suction hole 15. Since it is blocked by
Since air is not sucked from the upper end portion to the lower end portion, the air flow in the adsorption hole 15 hardly occurs. Therefore, the movable portion 18b of the check valve 18 provided in the suction hole 15 corresponding to the region of the suction plate 13 in contact with the sheet 2 moves from the position where the space 15b is opened to the space 15b.
Since no force is generated to move the suction fan 14 toward the closed position, in the initial state (see FIG. 3 (a)), even if the operation of the suction fan 14 is started, the movable portion 18b has the gap 1
5b is held in the open position. In other words, the check valve 18 provided in the suction hole 15 corresponding to the area of the suction plate 13 that contacts the sheet 2 opens the suction hole 15 regardless of whether the suction fan 14 is operating or stopped. In this case, the negative pressure generated by the suction fan 14 is brought into close contact with the upper end of the suction hole 15 by pulling the sheet 2 toward the suction hole 15.

As described above, in the ink jet printer 1 according to this embodiment, the paper 2 having different widths is used.
When printing is performed on the suction plate 15, the check valve 18 provided in the suction hole 15 of the suction plate 13 is in a state of closing the suction hole 15 according to the width of the sheet 2, 1
It is automatically divided into a state where 5 is opened.

That is, when the sheet 2 having a width substantially the same as the width of the suction plate 13 is used, as shown in FIG.
The check valves 18 provided in all the suction holes 15 are held in a state in which the suction holes 15 are opened, because the check valves 18 correspond to the regions where the suction holes 15 contact.

On the other hand, for example, when the sheet 2 having a width approximately half the width of the suction plate 13 is used, as shown in FIG. 4B, the suction formed in the vicinity of the central portion in the width direction of the suction plate 13. Since the holes 15 correspond to the areas in contact with the sheet 2, the check valves 18 provided in the suction holes 15 are provided.
Is held in a state where the suction holes 15 are opened, but the suction holes 15 formed in the vicinity of the widthwise end portions of the suction plate 13, that is, in the regions protruding from the widthwise both ends of the suction plate 13 of the sheet 2, , The check valves 18 provided in the suction holes 15 corresponding to the areas where the sheets 2 do not come into contact with each other.
Are held in a state in which the suction holes 15 are closed.

In the present embodiment, when the sheet 2 is started to be attracted to the surface of the attraction plate 13 at the start of printing, the attraction force of the attraction fan 14 is once the normal attraction force (for attracting the sheet 2). It is adjusted to be larger than the required suction force). Then, after the suction hole 15 corresponding to the area where the sheet 2 does not contact is completely closed by the check valve 18 provided therein (the movable portion 18b of the check valve 18 is held at the position where the gap 15b is closed). (After the above), the suction force by the suction fan 14 is adjusted to the normal suction force. As a result, the movable portion 18b of the check valve 18 moves back and forth between the position that closes the gap 15b and the position that opens the gap 15b. It is possible to prevent the sheet 2 from being properly sucked on the surface of the suction plate 13 by switching between the state in which the sheet is closed and the state in which the suction hole 15 is opened.

Further, when the sheet 2 is sucked onto the surface of the suction plate 13, a part of each suction hole 15 corresponds to a region of the suction plate 13 with which the sheet 2 comes into contact, and
When the remaining portion corresponds to a region of the suction plate 13 where the sheet 2 does not come into contact, the suction holes 15 are preferably closed by the check valve 18, but not necessarily by the check valve 18. You don't have to. That is, for example, when the widthwise end of the sheet 2 adsorbed on the adsorption plate 13 is near the central position of a certain adsorption hole 15, about half of the adsorption hole 15 on the sheet 2 side is the sheet 2. Corresponding to the area where the sheet 2 contacts, and the remaining half of the suction hole 15 (on the side opposite to the sheet 2) corresponds to the area where the sheet 2 does not contact. Incidentally, in general, the suction holes 15
When the sheets are arranged so as to form a row along the conveyance direction of the paper 2, a plurality of suction holes 15 corresponding to the row are formed.
At the same time, the above-mentioned situation often occurs.

As described above, according to the ink jet printer 1 of this embodiment, the paper 2 is held by the suction plate 13.
When it is adsorbed on the surface of the suction plate 13, the check valve 18 closes only the suction hole 15 corresponding to the area of the suction plate 13 where the paper 2 does not come into contact, so that the sheet 2 is adhered to the surface of the suction plate 13. As a result, it is possible to prevent the air from flowing in from the suction holes 15 corresponding to the regions of the suction plate 13 that are not in contact with the paper 2 while ensuring the flatness of the printing surface of the paper 2. Therefore, it is possible to prevent the paper 2 from being contaminated due to the ink mist or the like generated during printing adhering to the surface of the suction plate 13. Also,
Since the ink mist is sucked into the back surface side of the suction plate 13, it is possible to prevent the electric fan and other electric parts from malfunctioning. Further, in consideration of the amount of air sucked from the suction holes 15 of the suction plate 13 that are not blocked, it is not necessary to use a suction fan that is larger than necessary, so that the size of the printer is increased, the cost of parts is increased, the power consumption is increased, and heat is generated. Further, it is possible to suppress the occurrence of problems such as an increase in noise.

Further, the check valve 18 provided in the suction hole 15 corresponding to the area of the suction plate 13 where the sheet 2 does not come into contact.
Automatically closes the adsorption holes 15 by the flow of air generated by the adsorption fan 14, so that the check valve 1
No separate device for driving 8 is required. Therefore, the structure of the inkjet printer 1 can be simplified and the manufacturing cost thereof can be prevented from increasing.

Further, since the check valve 18 is formed of one plate-like non-air-permeable member having elasticity, air flows in from the suction holes 15 corresponding to the regions of the suction plate 13 where the sheet 2 does not contact. Never.

Although the preferred embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various design changes can be made within the scope of the claims. Is possible. For example,
In the above-described embodiment, the case where the check valve, which is an elastic plate-shaped member having a substantially V-shape, is used. When sucked on the surface of the suction plate 13, the suction fan 15 is moved by the flow of air generated by the suction fan 14 to close the suction holes 15 corresponding to the regions of the suction plate 13 that are not in contact with the sheet 2. If so, it can be arbitrarily changed.

Therefore, as shown in FIG. 5, when all the step portions 16 formed in the suction holes 15 of the suction plate 13 are not on the same plane, a planar plate-like check valve having elasticity. 58 may be used. In this case, in the initial state (when the suction fan 14 is stopped), the movable portion 58b of the check valve 58 is arranged in the same plane as the fixed portion 58a, as shown in FIG. , Is held at a position where the gap 15b is opened. Then, when the operation of the adsorption fan 14 is started, air is sucked from the upper end portion of the adsorption hole 15 toward the lower end portion thereof, and the flow of air generated in the adsorption hole 15 causes the movable portion 58b to move. Toward the position that closes the void 15b (in the direction of the solid line arrow in FIG. 5 (a)), rocking starts with the boundary with the fixed portion 58a as a fulcrum. Thereafter, as shown in FIG. 5B, the movable portion 58b swings to a position that closes the gap 15b and is held at a position that closes the gap 15b until the operation of the adsorption fan 14 is stopped. .

Further, in the above embodiment, the case where the check valve 18 provided in each of the suction holes 15 of the suction plate 13 is provided as the closing means has been described, but the present invention is not limited to this. When the paper 2 is adsorbed on the surface of the suction plate 13, the suction holes 18 corresponding to the areas of the suction plate 13 that contact the paper 2 are not closed, and correspond to the areas of the suction plate 13 that the paper 2 does not contact. Any material may be used as long as it is configured to close the suction holes 18. Therefore, for example, the inkjet printing unit 6 has a size capable of closing the plurality of suction holes 15 of the suction plate 13 at a time, and a plate-shaped member arranged so as to contact the back surface of the suction plate 13. , A drive mechanism for moving the plate-shaped member, and when the sheet 2 is sucked onto the surface of the suction plate 13, the suction plate 1 is adjusted to the width of the sheet 2.
The plate-shaped member may be moved so as to close only the suction holes 18 corresponding to the areas of the sheet 3 where the sheet 2 does not contact.

Further, in the above-described embodiment, the check valve 18
Describes the case where the state of automatically closing the suction hole 15 and the state of opening the suction hole 15 are automatically switched by the flow of air in the suction hole 15, but the present invention is not limited to this, and each state of the check valve 18 is described. May be manually switched between a state where the suction hole 15 is closed and a state where the suction hole 15 is opened. When the inkjet printing unit 6 has the plate-shaped member as described above, the position of the plate-shaped member may be changed by manually driving the driving unit. Moreover, the inkjet printing unit 6 does not have a drive means but has only a plate-shaped member, and the position of the plate-shaped member may be changed manually.

Further, in the above-described embodiment, the case where the closing mechanism is constituted by the check valve 18 which is one plate-like elastic non-air-permeable member has been described, but the present invention is not limited to this. First, the closing mechanism is generated by the suction fan 14 so as to close the suction holes 15 corresponding to the areas of the suction plate 13 that are not in contact with the sheet 2 when the sheet 2 is sucked onto the surface of the suction plate 13. It may have any configuration as long as it includes one or more non-breathable members that can move by the flow of air. Therefore, the closing mechanism may include a non-breathable member having no elasticity and a separate mechanism for elastically operating the non-breathable member.

Further, as the print medium in the ink jet printer of the present invention, thin plastic or the like can be used in addition to paper.

[0047]

As described above, according to the first aspect, when the print medium is adsorbed on the surface of the auxiliary member,
Since only the suction holes corresponding to the areas of the auxiliary member that do not come into contact with the print medium are closed by the closing means, the print medium is brought into close contact with the surface of the auxiliary member and the flatness of the print surface of the print medium is ensured. It is possible to prevent air from flowing in from the suction holes corresponding to the regions of the member that are not in contact with the print medium. Therefore, it is possible to prevent the print medium from being contaminated due to the ink mist or the like generated during printing adhering to the surface of the auxiliary member. Further, it is possible to prevent the ink mist from being sucked into the back surface side of the auxiliary member to cause a failure of electric parts such as the suction means. Further, in consideration of the amount of air sucked from the suction holes of the auxiliary member that are not blocked, it is not necessary to use a larger suction means than necessary, so that the size of the printer is increased,
It is possible to suppress problems such as an increase in component cost, an increase in power consumption, an increase in heat generation and an increase in noise.

According to the second aspect, the non-air-permeable member included in the closing mechanism provided in the suction hole corresponding to the area of the auxiliary member which does not come into contact with the print medium is automatically operated by the flow of air generated by the suction means. In addition, since the suction holes are closed, a separate device for moving the non-air-permeable member is not required. Therefore, the structure of the ink jet printer can be simplified and the manufacturing cost can be prevented from increasing. Further, since the suction holes corresponding to the regions of the auxiliary member that are not in contact with the print medium are closed by the non-air-permeable member, air does not flow from the suction holes corresponding to the regions of the auxiliary member that are not in contact with the print medium.

According to the third aspect, since the non-air-permeable member included in the closing mechanism is a member having plate-like elasticity, it is necessary to provide a separate mechanism for elastically operating the non-air-permeable member. Absent. Therefore, the structure of the closing mechanism can be simplified.

[Brief description of drawings]

FIG. 1 is a diagram showing a schematic configuration of an inkjet printer according to an embodiment of the present invention.

2 is a diagram showing a schematic configuration in the vicinity of an inkjet printing unit of the inkjet printer of FIG.

FIG. 3 is a view for explaining the operation of the check valve arranged in the suction hole.

FIG. 4 is a sectional view taken along line IV-IV in FIG.

FIG. 5 is a diagram showing another example of the configuration of the check valve.

[Explanation of symbols]

1 Inkjet printer 2 paper (print media) 6 Inkjet printing unit 8 Conveyor roller unit (conveying means) 11 Print head (ink ejection section) 13 Suction plate (auxiliary member) 14 Adsorption fan (adsorption means) 18, 58 Check valve (closing mechanism)

Claims (3)

[Claims] 1. A carrying unit for carrying a print medium, an ink ejecting unit for ejecting ink by an ink jet method to the print medium carried by the carrying unit, and a print medium arranged to face the ink ejecting unit. An auxiliary member having substantially the same height as the transport surface of the auxiliary member and having at least one suction hole formed therein, and an adsorption member for adsorbing a print medium onto the surface of the auxiliary member via the adsorption hole of the auxiliary member. And a suction hole corresponding to a region of the auxiliary member which is in contact with the print medium when the print medium is sucked onto the surface of the auxiliary member, which corresponds to a region of the auxiliary member which is not in contact with the print medium. And a closing means for closing the suction hole. 2. The closing means has an elastically operable closing mechanism provided in each of the suction holes of the auxiliary member, and when the print medium is sucked onto the surface of the auxiliary member. The one or more non-air-permeable members included in the closing mechanism provided in the suction hole corresponding to the area of the auxiliary member that does not come into contact with the print medium are moved by the flow of air generated by the suction unit. The inkjet printer according to claim 1, wherein the suction hole is closed by the. 3. The ink jet printer according to claim 2, wherein the closing mechanism is composed of one plate-like non-air-permeable member having elasticity.