JP2017205956A - Liquid discharge device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent deterioration of the ability of recovering an ink made into mist and floating in air.SOLUTION: A liquid discharge device includes: a transport part which transports a sheet while holding the sheet on a cylindrical shape drum; a liquid discharge head which discharges a liquid toward the cylindrical shape drum; and an empty discharge ink recovery part 6 which recovers the liquid discharged to an area of the cylindrical shape drum where the sheet is not held. The empty discharge ink recovery part 6 is formed by disposing a porous absorber 61, which recovers a liquid, in an air duct 60, includes a suction part which suctions air from an interior part of the air duct 60, and has an air passage route 66, through which air passes without passing through the porous absorber 61, between the air duct 60 and the porous absorber 61.SELECTED DRAWING: Figure 3

Description

  The present invention relates to an apparatus for discharging a liquid.

  As an image forming apparatus, for example, a recording medium (hereinafter, also referred to as a paper, but limited in material) is used as a liquid ejecting apparatus including a liquid ejecting head that ejects a recording liquid (liquid) droplet (ink droplet). Rather than transporting the object, printing medium, recording medium, recording paper, transfer material, recording paper, etc.), liquid is attached to the recording medium to form an image (recording, printing, printing) , Printing is also used synonymously).

  In such an apparatus for ejecting liquid, an image forming apparatus that holds and conveys a recording medium on the surface of a cylindrical drum and ejects the liquid toward the recording medium held on the cylindrical drum to form an image. Are known.

  In addition, the image forming apparatus may perform idle ejection control for ejecting ink that does not contribute to image formation (referred to as idle ejection ink, preliminary ejection ink, flushing ink, etc.) for maintenance and moisture retention of the liquid ejection head. Are known.

  In the image forming apparatus configured to hold and transport the recording medium on the surface of the cylindrical drum, an opening is provided in an area between the recording media held on the surface of the cylindrical drum (referred to as an inter-paper area). Yes, empty ink is ejected to the opening in the inter-paper area, and the air is sucked from the absorber provided in the opening and the inner side of the absorber (inside the cylindrical drum). It is known to collect discharged ink (see Patent Documents 1 to 3).

  However, conventionally, in an image forming apparatus that performs idle ejection to an opening provided on the surface of a cylindrical drum, all of the idle ejection ink that is ejected toward the opening is air-sucked through the absorber, and the absorber As the amount of impregnated ink discharged into the ink increased, the absorber was clogged and the air suction force was reduced. As a result, there has been a problem in that the ability to collect ink (hereinafter also referred to as mist ink) that has been lost in the air due to the mist of the main droplet ink discharged in the air being misted during flight is reduced.

  In view of this, the present invention relates to a device for ejecting liquid that has a mechanism for ejecting and recovering empty ejected ink to the inter-sheet area of a cylindrical drum, and that the ability to collect ink that has become mist and floats in the air is reduced. An object of the present invention is to provide an apparatus for discharging a liquid that can be prevented.

  In order to achieve this object, an apparatus for discharging liquid according to the present invention includes a transport unit that holds and transports a recording medium on a cylindrical drum, and a liquid discharge head that discharges liquid toward the cylindrical drum. In the cylindrical drum, a liquid recovery unit that recovers the liquid discharged to an area where the recording medium is not held, and the liquid recovery unit recovers the liquid in an air duct. And a suction part that sucks air from inside the air duct, and has a path through which air passes without passing through the absorber between the air duct and the absorber. Is.

  According to the present invention, it is possible to prevent the recovery ability of ink that has become mist and floated in the air from decreasing.

1 is a schematic configuration diagram illustrating an overall configuration of an image forming apparatus. FIG. 3 is an enlarged configuration diagram of an image forming unit. FIG. 4A is a schematic cross-sectional view illustrating an example of an empty discharge ink recovery unit, and FIG. 5B is a schematic perspective view illustrating an example of an empty discharge ink recovery unit. FIG. 6A is a schematic cross-sectional view illustrating another example of the idle ejection ink recovery unit, and FIG. 7B is a schematic perspective view illustrating another example of the idle ejection ink recovery unit. It is a perspective view which shows the structural example of an image formation part. It is a perspective view which shows the structural example of the image forming part which has two or more propeller fans. It is an enlarged block diagram which shows the other structural example of an image formation part. It is a perspective view which shows the other structural example of an image formation part. It is sectional drawing of the drive part which rotates a propeller fan. It is an enlarged view which shows the state which accommodated the porous absorber in the absorber container. It is explanatory drawing which shows the mode of the discharge of the empty discharge ink to a porous absorber. (A) is a side view of the idle ejection ink recovery part, and (B) is a top view of the idle ejection ink recovery part.

  Hereinafter, a configuration according to the present invention will be described in detail based on the embodiment shown in FIGS.

  The apparatus for discharging liquid according to the present embodiment is directed to a conveyance unit (image forming unit 1) that holds and conveys a recording medium (paper 11) on a cylindrical drum (cylindrical drum 3), and to the cylindrical drum. A liquid discharge head (liquid discharge head 2) for discharging the liquid, and a liquid recovery section (empty discharge ink recovery section 6) for recovering the liquid discharged to the area where the recording medium is not held in the cylindrical drum. In the apparatus (image forming apparatus 100) that discharges the liquid, the liquid recovery unit includes an absorber (porous absorber 61) that recovers the liquid in an air duct (air duct 60), and the air. A suction part (propeller fan 63) for sucking air from inside the duct is provided, and a path (air passage path 66) through which air passes without passing through the absorber is provided between the air duct and the absorber. It is intended to. In addition, the code | symbol in embodiment and the example of application are shown in a parenthesis.

(Image forming device)
An image forming apparatus (inkjet recording apparatus) which is an embodiment of an apparatus for ejecting liquid according to the present invention will be described.

  FIG. 1 is a schematic configuration diagram illustrating the overall configuration of the image forming apparatus. FIG. 1 shows an overall configuration of an image forming apparatus 100 including a liquid discharge head 2 for spraying ink by an ink jet method and an image forming unit 1 equipped with a method for holding and transporting a sheet 11 on the surface of a cylindrical drum 3. Is shown. Hereinafter, the configuration and operation of the image forming apparatus 100 will be described with reference to FIG.

  First, the sheets 11 stacked on the sheet feeding unit 10 are picked up one by one by the air separation unit 12 and sent in the direction of the image forming unit 1. The sheet 11 is sent from the sheet feeding unit 10 to the registration adjusting unit 20. In the registration adjusting unit 20, registration correction of the paper 11 is performed by the registration roller 21.

  The registration-adjusted sheet 11 is sent to the image forming unit 1, and the leading end of the sheet 11 is sandwiched between the sheet grippers 4 provided on the surface of the cylindrical drum 3. In this state, the cylindrical drum 3 is rotationally driven and conveyed in the rotation direction indicated by the arrow, and is conveyed to a position where the liquid discharge head 2 is provided. A plurality of liquid ejection heads 2 are arranged in the main scanning direction (the depth direction in the figure).

  An infinite number of air suction holes 5 (see FIG. 2) are provided on the surface of the cylindrical drum 3, and the entire paper 11 is sucked from the back surface by an air suction mechanism to be in close contact with the surface of the cylindrical drum 3. ing. A unit of the liquid ejection head 2 is arranged along the surface of the cylindrical drum 3 in a state where a predetermined ink color is filled.

  When the paper 11 is sent to the lower part of the liquid discharge heads 2 for the respective colors, the liquid discharge head 2 discharges ink to form an image. In the example of FIG. 1, a configuration including four color liquid ejection heads of black, cyan, magenta, and yellow is shown. In addition, a liquid discharge head for discharging overcoat ink or white ink may be provided on the downstream side of the sheet conveyance.

  In addition, a paper gripper 4 that holds the leading end of the paper 11 is attached to three places on the surface of the cylindrical drum 3, and three sheets of paper 11 can be conveyed by one rotation of the cylindrical drum 3. . The position of the leading edge of the sheet 11 is determined by the sheet gripper 4, and the positional deviation during conveyance of the sheet is prevented by air suction, thereby preventing the image position deviation.

  After the ink is landed on the paper 11 to form an image, the paper 11 is sent to the drying unit 30. The drying unit 30 is provided with a drying unit 31. The paper 11 passes through the lower part of the drying unit 31 to evaporate moisture in the ink and prevent the paper 11 from curling.

  In addition, the drying unit 30 is provided with a paper reversing unit 51 and a paper reversing and conveying unit 50. At the time of duplex printing, the paper reversing unit 51 switches the conveying direction of the paper 11, and then the paper reversing and conveying unit. 50, the image is conveyed again to the image forming unit 1.

  At the time of duplex printing, the registration of the paper 11 is corrected by the registration roller 52 before reaching the cylindrical drum 3. In the image forming unit 1, image formation is performed on the reversed paper 11.

  The paper 11 that has passed through the drying unit 30 is conveyed to the paper discharge unit 40, and the paper 11 is discharged to the paper discharge tray 41.

(Image forming part)
[First Embodiment]
FIG. 2 is an enlarged configuration diagram of the image forming unit 1 of the image forming apparatus 100. FIG. 2 shows a state in which ink is ejected while the liquid ejection head 2 is close to the surface of the cylindrical drum 3.

  The cylindrical drum 3 is rotationally driven by a stepping motor 70 that is a driving means. The rotation of the pulley drive motor 71 fixed to the shaft of the stepping motor 70 is transmitted to the pulley driven drum 73 via the timing belt 72.

  The pulley driven drum 73 is fixed to the cylindrical drum 3, and the driving force is transmitted to the pulley driving motor 71, the timing belt 72, and the pulley driven drum 73 by the rotation of the stepping motor 70, and the cylindrical drum 3 is moved to the arrow. Rotate in the direction.

  In the cylindrical drum 3, in addition to the paper gripper 4 and the air suction hole 5, an opening of an empty discharge ink collection unit 6 that collects the empty discharge ink in a region excluding the region where the paper gripper 4 and the air suction hole 5 are formed. A portion 69 is provided. In the present embodiment, three empty ejection ink collection units 6 are provided, but the number of the empty ejection ink collection units 6 is not limited to this.

  An air duct 60 is disposed inside the opening 6, and a porous absorber 61 is provided inside the air duct 60. The empty ejection ink is absorbed by the porous absorber 61. The porous absorber 61 is replaceable and is periodically replaced.

  An air suction connection path 62 extending from the bottom surface of the air duct 60 toward the center of the cylindrical drum 3 is provided. The air suction connection path 62 is an air suction formed in the axial direction of the cylindrical drum 3. It communicates with the main path 64. A propeller fan 63 is fixed to the end of the air suction main path 64.

  Here, when the cylindrical drum 3 is driven and rotated, the components (the air duct 60, the air suction connection path 62, and the air suction main path 64) arranged inside the cylindrical drum 3 also rotate together. Further, since the propeller fan 63 is also integrally fixed to the air suction main path 64, it rotates at the same rotational speed as that of the cylindrical drum 3.

  The propeller fan 63 rotates to generate an air flow, and the air inside each air suction path (the air duct 60, the air suction connection path 62, and the air suction main path 64) is discharged out of the image forming apparatus 100. It is flowing in the direction.

  By the way, as an air suction means in such an image forming apparatus 100, it is common to use an axial flow type propeller fan, a centrifugal sirocco fan, or a diaphragm type or rotary type suction pump. is there. These fans and pumps use a motor as drive means, and many fans and pumps and motors are configured as an integral unit.

  As the driving means for the cylindrical drum 3, the motor (stepping motor 70) is used as described above. For this reason, conventionally, it has been necessary to mount a driving means (motor) for a fan or a pump and a driving means (motor) for the cylindrical drum 3, which has led to an increase in the cost of the apparatus.

  On the other hand, in the image forming apparatus 100 according to the present embodiment, the propeller fan 63 is constituted only by the blade portion to rotate with the rotation of the cylindrical drum 3, and driving means (motor) for the propeller fan 63. Is not provided. In other words, the power source of the propeller fan 63 and the power source of the cylindrical drum 3 are used as one drive unit. Therefore, it is not necessary to provide driving means for the propeller fan 63, and the cost of the apparatus can be reduced by reducing the number of motors used.

  When the fan and the motor are an integrated air suction fan motor, it is necessary to select a waterproof type in consideration of the intrusion of ink, resulting in an increase in cost. In addition, the waterproof fan motor is equipped with a seal member such as rubber at the rotating part. However, due to deterioration over time, there is a concern that the waterproof property is impaired and ink enters the inside and causes malfunction. However, these problems do not occur in the image forming apparatus 100 according to the present embodiment.

  In addition, in the image forming apparatus 100 according to the present embodiment, a space for providing the driving unit is not necessary, which can lead to space saving. Furthermore, since there is no need to arrange an electric part such as a motor in the air suction path such as the air suction main path 64, mist-like ink passing through the air suction path adheres to or enters the electrical part. It is possible to improve the reliability of the apparatus without causing malfunction due to electrical damage (breakage due to electrical short).

  FIG. 3A is a schematic cross-sectional view of the idle ejection ink collection unit 6, and FIG. 3B is a schematic perspective view of the idle ejection ink collection unit 6. The idle ink collection unit 6 includes an air duct 60 and an air suction connection path 62. Inside the air duct 60, an absorber container 67 that houses a porous absorber 61 is provided.

  Here, the absorber container 67 is provided so as to be separated from the inner wall of the air duct 60, and is indicated by a circle in the figure between the inner wall of the air duct 60 and the outer wall of the absorber container 67. An air passage path 66 is formed.

  The air passage path 66 makes it possible to create an air flow even when the porous absorbent body 61 absorbs the empty ejection ink.

  Here, when the idle ejection ink is ejected by the idle ejection ink collection unit 6, not all of the ink lands on the porous absorber 61 in the air duct 60, but becomes a mist and enters the air. There are many things that float (called mist ink).

  In order to collect the ink that has become mist and floated in the air, the air is sucked by the propeller fan 63, and the air duct 60 and the air suction connection path 62 are made negative pressure. The ink thus formed can be collected by being sucked into the air duct 60 and the air suction connection path 62 from the air passage path 66.

  The absorber container 67 that houses the porous absorber 61 is detachable from the air duct 60. Since the porous absorbent body 61 absorbs most of the main ejection ink that is ejected empty, it is detected that a predetermined amount of the ejected ink has been absorbed, and the absorbent container 67 is periodically replaced. Also, the mist ink that has become mist and floated in the air is sucked and collected from the air passage path 66 into the air duct 60, but the amount of ink is relatively small.

  In the example of FIG. 3, the configuration in which the air passage path 66 is provided between the inner wall of the air duct 60 and the porous absorber 61 is shown, but the formation position of the air passage path 66 is limited to this. Instead, for example, the air passage 66 may be provided in the center in the width direction of the porous absorber 61. Even if the porous absorber 61 absorbs ink, it may be at a position where air flow can be secured.

  Another example of the idle ejection ink recovery unit 6 will be described. 4A is a schematic cross-sectional view of the idle ejection ink collection unit 6, and FIG. 4B is a schematic perspective view of the idle ejection ink collection unit 6. The idle ejection ink recovery unit 6 shown in FIG. 4 shows a configuration example in which an air filter 68 is further provided inside the air duct 60 in addition to the configuration shown in FIG.

  The air filter 68 adsorbs mist ink when the mist ink is sucked and collected from the air passage path 66 into the air duct 60. The air filter 68 is detachable from the air duct 60, and can be periodically replaced when impregnated with ink. In addition, since the mist ink is a very small amount of the entire empty ejection ink, the replacement frequency of the air filter 68 is extremely less than the replacement frequency of the porous absorber 61.

  Here, no gap is formed between the inner wall of the air duct 60 and the air filter 68. That is, since an air passage path 66 such as a gap between the air duct 60 and the porous absorber 61 is not formed, the air passes through the air filter 68.

  Further, the fiber density of the air filter 68 is coarser (fiber density is lower) than that of the porous absorbent body 61. This is because the amount of mist ink is small and the air suction capability is not reduced.

  FIG. 5 is a perspective view illustrating a configuration example of the image forming unit 1. A propeller fan 63 is fixed to one end side of the air suction main path 64. As described above, the propeller fan 63 also rotates at the same rotation speed by the rotation of the cylindrical drum 3.

  The rotation of the propeller fan 63 causes the air inside each air suction path to flow in the direction of discharging out of the apparatus. An exhaust duct 65 is attached to the propeller fan 63 side (exhaust port) of the air suction main path 64.

  Air sucked from each air suction path by the propeller fan 63 is discharged in the direction of the arrow of the exhaust duct 65. A porous last chance filter is attached to the downstream side in the direction of the arrow, and has the role of finally capturing the ink that has been sucked.

  The exhaust duct 65 is fitted to the outer periphery of the end of the air suction main path 64. The air suction main path 64 rotates together with the cylindrical drum 3, but the exhaust duct 65 is fixed and does not rotate together. For this reason, the fitting part of both parts is set as the structure which receives rotational friction by providing a sliding bearing, a ball bearing part, etc. in a fitting part.

  So far, in the image forming apparatus 1, the example in which the three empty ejected ink collection units 6 are provided has been described, but the number of each unit is not limited to this. For example, when the diameter of the cylindrical drum 3 is large and the number of sheets 11 held per rotation is four, the number of idle ejection ink collection units 6 is four.

  Further, the number of propeller fans 63 may be obtained as long as a necessary air volume is obtained, and changes depending on the number of empty ejection ink collecting portions 6, the area of the opening 69, the size of the propeller fan 63, the mist ink scattering state, and the like. Depending on this, an optimal number may be set.

  FIG. 6 is a perspective view showing a configuration example of the image forming unit 1 having a plurality of propeller fans 63 (here, three). By having a plurality of propeller fans 63, the air flow can be further increased. For example, when there are a large number of idle ejection ink collection units 6, a large amount of air suction is required, so it is effective to increase the number of propeller fans 63.

  In the image forming apparatus according to the first embodiment described above, when the porous absorber 61 is installed in the air duct 60, the main droplets of the empty ejection ink can be exchanged by landing on the porous absorber 61. In addition, by providing an air passage path 66 between the air duct 60 and the porous absorbent body 61, the porous absorbent body 61 is clogged by impregnated with the empty ejection ink, causing a reduction in air suction force. Thus, the ability to collect mist ink is not lowered, and the ink collecting function can be maintained for a long time.

[Second Embodiment]
Hereinafter, other embodiments of the apparatus for ejecting liquid according to the present invention will be described. In addition, the description about the same point as the said embodiment is abbreviate | omitted suitably.

  FIG. 7 is an enlarged configuration diagram illustrating another configuration example of the image forming unit 1 of the image forming apparatus 100. FIG. 8 is a perspective view of the image forming unit 1 shown in FIG. FIG. 9 is a cross-sectional view of a drive portion that rotates the propeller fan.

  Since the propeller fan 63 of the image forming unit 1 described in the first embodiment is fixed to the air suction main path 64, the rotation speed is the same as the rotation speed of the cylindrical drum 3. Therefore, the rotation speed of the propeller fan 63 cannot be arbitrarily changed.

  On the other hand, in this embodiment, the propeller fan 63 is in a state independent of the air suction main path 64 and is fixed to the propeller fan drive shaft 77 disposed at the center of the air suction main path 64 to rotate. The propeller fan drive shaft 77 passes through the center of the pulley driven drum (large) 73 and is fixed to the pulley driven drum small 76 on the back side.

  The pulley driven drum small 76 is connected to a pulley driving motor large 74 fixed to the shaft of the stepping motor 70 by a timing belt 75, and transmits the rotation driving of the stepping motor 70 to the propeller fan driving shaft 77 to rotate the propeller fan 63. I am letting.

  As shown in FIG. 9, the pulley driven drum small 76, the propeller fan drive shaft 77, and the propeller fan 63 are fixed and rotate integrally. A large bearing 78 is press-fitted into the center of the pulley driven drum (large) 73, supports one side of the propeller fan drive shaft 77, and the other propeller fan drive shaft 77 is press-fitted into the air suction main path 64. It is supported by a small bearing 79.

  In the configuration according to the second embodiment, the rotation speed of the propeller fan 63 can be changed by changing the ratio of the number of teeth of the pulley driven drum small 76 and the pulley drive motor large 74. In the second embodiment, the number of teeth of the pulley driven drum small 76 on the cylindrical drum 3 side is made smaller than the number of teeth of the pulley drive motor large 74 on the stepping motor 70 side. Can be rotated at a higher speed than the configuration described in the first embodiment.

  Conversely, if the number of teeth of the pulley drive motor large 74 is reduced and the number of teeth of the pulley driven drum small 76 is increased, the rotational speed of the propeller fan 63 can be reduced.

  Similarly to the first embodiment, an exhaust duct 65 is attached to the outlet of the propeller fan 63, and the air sucked from each air suction path by the propeller fan 63 is discharged in the direction of the arrow of the exhaust duct 65. The

  7 to 9 show an example in which the number of propeller fans 63 is one. However, as described above, a plurality of propeller fans 63 may be fixed to the propeller fan drive shaft 77. .

  As described above, in the second embodiment, the rotation speed of the propeller fan 63 that does not have a dedicated drive means can be arbitrarily set, so that it is possible to set the rotation speed of the propeller fan 63 to an optimum value. It has become.

  For example, the air flow rate can be increased by increasing the rotation speed of the propeller fan 63. For this reason, when the number of idle ejection ink collection units 6 (the number of installed air ducts 60) is large, a large amount of air suction is required, so the configuration of this embodiment is effective.

(Porous absorber)
Next, the detail of a porous absorber is demonstrated. FIG. 10 is an enlarged view showing a state where the porous absorbent body 61 is housed in the absorbent body container 67.

  The porous absorbent body 61 is made of, for example, a felt material in which wool or chemical fiber is woven, and has a weave direction. In the present embodiment, the porous absorbent body 61 is arranged vertically so that the weave direction of the porous absorbent body 61 and the ink discharge direction of the liquid discharge head 2 are horizontal.

  In the example shown in FIG. 10, five porous absorbent bodies 61 are accommodated in an absorbent body container 67, and each porous absorbent body 61 is stepped in a mountain shape so as to follow the curvature of the outer periphery of the cylindrical drum 3. Are provided and superimposed. With such an arrangement, the surface portion of the porous absorber 61 can be brought close to the outer peripheral surface of the cylindrical drum 3.

  By approaching the outer peripheral surface of the cylindrical drum 3, the nozzle surface 2 a of the liquid discharge head 2 and the surface of the porous absorber 61 can be brought closer to each other. Accordingly, by shortening the flying distance of the ink ejected in the sky (appropriate distance), the ink droplets are less likely to be misted during the flight and float and fly in the air, and the inside of the apparatus is soiled with the mist ink or the liquid ejecting head 2 The occurrence of nozzle down due to ink adhering to the nozzle surface 2a can be suppressed.

  Further, since the absorbability is good in the horizontal direction with respect to the texture direction of the porous absorbent body 61, the ink is absorbed in the depth direction by arranging the porous absorbent body 61 in the vertical direction as shown in FIG. And the ink penetrates to the bottom of the absorber container 67.

  In FIG. 10, five porous absorbent bodies 61 are overlapped. However, depending on the curvature of the cylindrical drum 3, the thickness of each porous absorbent body 61, and the width of the absorbent container 67, the porous body 61 is porous. What is necessary is just to select the number of the absorbers 61 suitably. It is important to spread the surface of the porous absorbent body 61 so as to match the outer peripheral curvature of the cylindrical drum 3.

  Next, the ejection of empty ejection ink to the porous absorber 61 will be described. With reference to FIGS. 11 (A) to 11 (E), an embodiment when discharging the empty ink 80 to the porous absorber 61 will be described. 11A to 11E show a state in which the empty ejection ink 80 is ejected from the porous absorbent body 61 on the upstream side in the rotation direction to the porous absorbent body 61 on the downstream side.

  Here, the ejection positions of the idle ejection ink 80 shown in FIGS. 11A to 11E are ejected at all positions shown in FIGS. 11A to 11E while the cylindrical drum 3 rotates once. For example, the first rotation is discharged at the position shown in FIG. 11A, the second rotation is discharged at the position shown in FIG. 11B, and the third rotation is discharged at the position shown in FIG. 11C. In the fifth rotation, the position at which the empty ink 80 is discharged is changed every time the cylindrical drum 3 rotates, such as discharging at the position shown in FIG.

  Thereby, the porous absorber 61 is made to absorb ink uniformly. The relationship between the discharge order and the discharge position is an example, and the present invention is not limited to this.

  At any position shown in FIGS. 11A to 11E, the distance between the nozzle surface 2a of the liquid ejection head 2 and the surface of the porous absorber 61 is a short distance of approximately equal distance, and the ink droplets fly. It is possible to reduce the occurrence of mist due to an increase in the distance, so that the inside of the apparatus is stained with mist ink, and the occurrence of nozzle down due to ink adhering to the nozzle surface 2a of the liquid ejection head 2 can be suppressed.

  In addition, less mist ink generation means that the amount of ink that passes through the air passage path 66 and is sucked into the air duct 60 is small. A beautiful state can be maintained over a long period of time, and the suction ability can be maintained for a long time.

  FIG. 11 shows a stack of five porous absorbers 61 and five ejection positions for the empty ejection ink 80, but the number of porous absorbers 61 and the ejection of the empty ejection ink 80 are also shown. The position (discharge location) is not limited to this, and may be set as appropriate depending on the curvature of the cylindrical drum 3, the thickness of each porous absorber 61, and the width of the absorber container 67. For example, when three porous absorbers 61 are overlapped, the ink discharge positions are three, and when seven porous absorbers 61 are overlapped, the ink discharge positions are seven. Control may be used.

  In addition, it is desirable that the position at which the empty ejected ink 80 is ejected is approximately the center in the width direction of the laminated porous absorbent bodies 61. By ejecting the empty ejection ink 80 in the center in the width direction, the empty ejection ink 80 can be uniformly absorbed by the entire porous absorber 61 (both in the width direction and in the depth direction).

(Empty ink collection part)
Next, a preferred embodiment of the idle ejection ink recovery unit 6 will be described. FIG. 12A is a side view of the idle ejection ink collection unit 6, and FIG. 12B is a top view of the idle ejection ink collection unit 6 as viewed from the direction of arrow A in FIG.

  Here, when the mist ink floats above the porous absorbent body 61, it flows to the downstream side in the rotation direction of the cylindrical drum 3, and components and members arranged on the downstream side in the rotation direction of the cylindrical drum 3. There is a problem that the actuator gets dirty with ink.

  Therefore, as shown in FIG. 12, the air passage path 66 is configured such that the width of the opening 69 is different between the air passage path 66 a on the upstream side in the rotation direction of the cylindrical drum 3 and the air passage path 66 b on the downstream side. The downstream opening width s2 is wider than the upstream opening width s1, and the downstream opening s2 can obtain a larger amount of air suction than the upstream opening s1. I have to.

  As a result, the mist ink is floating above the porous absorber 61 and is caused to flow downstream by the rotation of the cylindrical drum 3. And since it becomes easy to be sucked and collected from the opening s2 on the downstream side where the air suction amount is larger, it is possible to reliably suck and collect the mist ink that has flowed in the rotational downstream direction of the cylindrical drum 3.

  The combined surface area of the upstream opening s1 and the downstream opening s2 of the air passage path 66 is preferably 50% or less of the surface area of the porous absorbent body 61, for example. Moreover, it is preferable that the surface area of the upstream opening s1 is, for example, 45% or less of the total surface area of the upstream opening s1 and the downstream opening s2.

  The above-described embodiment is a preferred embodiment of the present invention, but is not limited thereto, and various modifications can be made without departing from the gist of the present invention.

  A “liquid ejection head” is a functional component that ejects and ejects liquid from a nozzle. The “liquid discharge head” is not limited to the pressure generating means to be used. For example, in addition to the piezoelectric actuator as described in the above embodiment (a multilayer piezoelectric element may be used), a thermal actuator using an electrothermal conversion element such as a heating resistor, a diaphragm and a counter electrode are included. An electrostatic actuator or the like may be used.

  In addition, the terms “image formation”, “recording”, “printing”, “printing”, “printing”, “modeling” and the like in the terms of the present application are all synonymous.

  Further, another functional component and mechanism are integrated with the liquid ejection head, and an assembly of components related to the function of ejecting liquid is referred to as a “liquid ejection unit”. For example, the “liquid discharge unit” includes a combination of at least one of a head tank, a carriage, a supply mechanism, a maintenance / recovery mechanism, and a main scanning movement mechanism with a liquid discharge head.

  Here, the term “integrated” refers to, for example, a liquid discharge head, a functional component, and a mechanism that are fixed to each other by fastening, adhesion, engagement, etc., and one that is held movably with respect to the other. Including. Further, the liquid discharge head, the functional component, and the mechanism may be configured to be detachable from each other.

  For example, there is a liquid discharge unit in which a liquid discharge head and a head tank are integrated. Also, there are some in which the liquid discharge head and the head tank are integrated by being connected to each other by a tube or the like. Here, a unit including a filter may be added between the head tank and the liquid discharge head of these liquid discharge units.

  In addition, there is a liquid discharge unit in which a liquid discharge head and a carriage are integrated.

  In addition, there is a liquid discharge unit in which the liquid discharge head and the scanning movement mechanism are integrated by holding the liquid discharge head movably on a guide member that constitutes a part of the scanning movement mechanism. In some cases, a liquid discharge head, a carriage, and a main scanning movement mechanism are integrated.

  Also, there is a liquid discharge unit in which a cap member that is a part of the maintenance / recovery mechanism is fixed to a carriage to which the liquid discharge head is attached, and the liquid discharge head, the carriage, and the maintenance / recovery mechanism are integrated. .

  In addition, there is a liquid discharge unit in which a tube is connected to a liquid discharge head to which a head tank or a flow path component is attached, and the liquid discharge head and a supply mechanism are integrated. The liquid from the liquid storage source is supplied to the liquid discharge head via this tube.

  The main scanning movement mechanism includes a guide member alone. The supply mechanism includes a single tube and a single loading unit.

  Further, the “apparatus that discharges liquid” is an apparatus that includes a liquid discharge head or a liquid discharge unit and drives the liquid discharge head to discharge the liquid. The apparatus for ejecting liquid includes not only an apparatus capable of ejecting liquid to an object to which liquid can adhere, but also an apparatus for ejecting liquid toward the air or liquid.

  This “apparatus for discharging liquid” may include means for feeding, transporting, and discharging a liquid to which liquid can adhere, as well as a pre-processing apparatus and a post-processing apparatus.

  For example, as a “liquid ejecting device”, an image forming device that forms an image on paper by ejecting ink, a powder is formed in layers to form a three-dimensional model (three-dimensional model) There is a three-dimensional modeling apparatus (three-dimensional modeling apparatus) that discharges a modeling liquid onto the powder layer.

  Further, the “apparatus for ejecting liquid” is not limited to an apparatus in which significant images such as characters and figures are visualized by the ejected liquid. For example, what forms a pattern etc. which does not have a meaning in itself, and what forms a three-dimensional image are also included.

  The above-mentioned “applicable liquid” means that the liquid can be attached at least temporarily and adheres and adheres, or adheres and penetrates. Specific examples include recording media such as paper, recording paper, recording paper, film, and cloth, electronic parts such as electronic substrates and piezoelectric elements, powder layers (powder layers), organ models, and test cells. Yes, unless specifically limited, includes everything that the liquid adheres to.

  The material of the above-mentioned “material to which liquid can adhere” is not limited as long as liquid such as paper, thread, fiber, fabric, leather, metal, plastic, glass, wood, ceramics can be adhered even temporarily.

  The “liquid” is not particularly limited as long as it has a viscosity and surface tension that can be ejected from the head, and the viscosity is 30 mPa · s or less at room temperature, normal pressure, or by heating and cooling. Preferably there is. More specifically, solvents such as water and organic solvents, colorants such as dyes and pigments, functional materials such as polymerizable compounds, resins, and surfactants, and biocompatible materials such as DNA, amino acids, proteins, and calcium. , Edible materials such as natural pigments, solutions, suspensions, emulsions, and the like. These include, for example, inkjet inks, surface treatment liquids, components of electronic devices and light emitting devices, and formation of electronic circuit resist patterns It can be used in applications such as liquids for use, three-dimensional modeling material liquids, and the like.

  In addition, the “device for ejecting liquid” includes a device in which the liquid ejection head and the device to which the liquid can adhere move relatively, but is not limited thereto. Specific examples include a serial type apparatus that moves the liquid discharge head, a line type apparatus that does not move the liquid discharge head, and the like.

  In addition to the “device for discharging liquid”, a processing liquid coating apparatus for discharging a processing liquid onto a sheet for applying a processing liquid to the surface of the sheet for the purpose of modifying the surface of the sheet, or a raw material There is an injection granulating apparatus or the like that granulates fine particles of a raw material by spraying a composition liquid in which a solution is dispersed in a solution through a nozzle.

DESCRIPTION OF SYMBOLS 1 Image formation part 2 Liquid discharge head 2a Nozzle surface 3 Cylindrical drum 4 Paper gripper 5 Air suction hole 6 Empty discharge ink collection part 10 Paper feed part 11 Paper 12 Air separation part 20 Registration adjustment part 21 Registration roller 30 Drying part 31 Drying Unit 40 Paper discharge unit 41 Paper discharge tray 50 Paper reversing conveyance unit 51 Paper reversing unit 52 Registration roller 60 Air duct 61 Porous absorber 62 Air suction connection path 63 Propeller fan 64 Air suction main path 65 Exhaust duct 66 Air passage path 67 Absorber container 68 Air filter 69 Opening 70 Stepping motor 71 Pulley drive motor 72 Timing belt 73 Pulley driven drum (large)
74 Large pulley drive motor 75 Timing belt 76 Pulley driven drum (small)
77 Propeller fan drive shaft 78 Large bearing 79 Small bearing 80 Empty ink 100 Image forming apparatus

Japanese Patent No. 5644140 Japanese Patent No. 5453929 Japanese Patent No. 5177869

Claims (10)

A transport unit that holds and transports a recording medium on a cylindrical drum;
A liquid discharge head for discharging liquid toward the cylindrical drum;
In the cylindrical drum, in the apparatus for ejecting liquid, including a liquid recovery unit that recovers the liquid discharged to an area where the recording medium is not held,
The liquid recovery unit is
An absorber that collects liquid in the air duct is disposed, and a suction part that sucks air from the inside of the air duct is provided.
An apparatus for discharging a liquid, characterized in that a path through which air passes without passing through the absorber is provided between the air duct and the absorber.   The apparatus for discharging a liquid according to claim 1, wherein the liquid recovery unit has the path on an upstream side and a downstream side in a rotation direction of the cylindrical drum.   3. The apparatus for ejecting liquid according to claim 2, wherein the surface area of the opening portion of the path on the surface of the cylindrical drum is larger in the downstream path than in the upstream path. .   The apparatus for discharging liquid according to any one of claims 1 to 3, further comprising a filter upstream of the path in the air suction path in the liquid recovery unit. The absorber is formed by overlapping a plurality of absorbers,
The apparatus for discharging a liquid according to any one of claims 1 to 4, wherein the absorber has a shape along the outer periphery curvature of the cylindrical drum.   6. When discharging a liquid from the liquid discharge head toward the absorber, the liquid is discharged at at least two positions in the rotation direction of the cylindrical drum. The apparatus which discharges the liquid of description.   The apparatus for discharging a liquid according to claim 1, wherein the absorber is detachably provided from the air duct.   The apparatus for ejecting liquid according to claim 1, wherein the suction unit includes one or more fans.   The apparatus for discharging a liquid according to claim 8, wherein the fan follows the rotational drive of the cylindrical drum.   The apparatus for discharging liquid according to claim 9, wherein the fan is rotated at a rotation speed set in advance with respect to the rotation speed of the cylindrical drum.