JP5629984B2 - Ink jet apparatus and image forming apparatus - Google Patents

Description

  The present invention relates to an ink jet apparatus that performs recording by discharging ink from an ink jet head to a recording medium, and an image forming apparatus including the same.

  When ink is ejected from an inkjet head, a large number of ink mists that are fine droplets may be formed in addition to ink that is a main droplet.

  The ink mist does not land on the recording medium, floats between the inkjet head and the recording medium, and finally, most of the ink mist adheres near the nozzle. The adhered ink mist may cause problems such as nozzle clogging and bending in the ink ejection direction.

  Patent Document 1 discloses an invention that collects ink mist only by an air flow on the downstream side in the moving direction of a recording medium with respect to an inkjet head.

  However, in the invention described in Patent Document 1, there is no configuration for introducing an air flow into the nozzle portion on the upstream side in the recording medium moving direction. For this reason, the air introduced between the nozzle and the recording medium becomes a turbulent flow, and there is a possibility that the ink mist is not easily guided toward the accumulation plate.

  The present invention has been made in view of the above problems, and an inkjet apparatus that collects charged ink mist by arranging and sending an air flow into a space formed between an inkjet head and a recording medium, and the same An object of the present invention is to provide an image forming apparatus used.

In order to achieve the above object, according to a first aspect of the present invention, there is provided an ink jet apparatus that ejects ink by an ink jet head including an ink ejecting unit that ejects and ejects ink from an ejection port to land on a recording medium. Rectifier that is provided on both sides of the ink jet in the moving direction of the recording medium with respect to the ink jet head, and charges the ink ejected from the ejection port and arranges the air flow into the space between the ink jet head and the recording medium. And a retention means that is provided downstream of the inkjet head in the direction of movement of the recording medium and retains an air flow including ink mist that is micro droplets of ink after passing through the space between the inkjet head and the recording medium And a collecting means for collecting the ink mist charged by the charging means, Is rotatable about a fulcrum provided on the side surface of the ink jet head in the recording medium moving direction downstream side, rectifying means of the recording member movement direction downstream side of the inkjet head in the recording medium moving direction downstream The present invention provides an ink jet device that can be retracted to the side surface of the ink jet head so that the distance between the head and the head is reduced .

  In order to achieve the above object, the present invention provides, as a second aspect, an image forming apparatus using the ink jet apparatus according to the first aspect of the present invention, by discharging ink from the ink jet apparatus. The present invention provides an image forming apparatus that forms an image on a recording medium.

  According to the present invention, it is possible to provide an ink jet apparatus that collects and charges charged ink mist by arranging and sending an air flow into a space formed between the ink jet head and the recording medium, and an image forming apparatus using the same. .

It is a figure which shows the structure of the inkjet apparatus which concerns on 1st Embodiment which implemented this invention suitably. It is a figure which shows the structure of the charging part of the inkjet apparatus which concerns on 1st Embodiment. It is a figure which shows the structure of a corotron. It is a figure which shows the structure of the inkjet apparatus which concerns on 2nd Embodiment which implemented this invention suitably. It is a figure which shows the structure of the inkjet apparatus which concerns on 3rd Embodiment which implemented this invention suitably. It is a figure which shows the structure of the rectification | straightening member of the inkjet apparatus which concerns on 3rd Embodiment. It is a figure which shows another structure of the rectification | straightening member of the inkjet apparatus which concerns on 3rd Embodiment.

[First Embodiment]
FIG. 1 shows a cross section of an ink jet apparatus according to a first embodiment in which the present invention is suitably implemented. FIG. 2 is an enlarged view of the charging unit that charges the ink.
The ink jet apparatus according to the present embodiment includes an ink jet head 1, a collection unit 2, a rectifying member 31, and a staying unit 41.
The ink jet head 1 includes a piezoelectric element 11, a vibration plate 12, an ink chamber 13, a nozzle 14, and a charging unit 15.

  The collection unit 21 collects the ink mist 8 generated by ink ejection. The rectifying member 31 is provided on the upstream side in the moving direction (arrow A direction) of the recording medium 5 with respect to the inkjet head 1. As shown in the figure, the rectifying action described later is easily adjusted by connecting the rectifying member 31 to the ink chamber 13 so that the rectifying member 31 can rotate via a fulcrum. The staying part 41 is provided on the downstream side in the moving direction of the recording medium 5 in order to retain the air flow including the ink mist 8.

  The ink-jet head 1 pressurizes and applies a voltage to the piezoelectric element 11 to cause the piezoelectric element 11 to expand and contract, and by applying pressure to the ink filled in the ink chamber 13 through the vibration plate 12 by the vibration, the ink is supplied. Is given kinetic energy, and the ink 7 is ejected from the nozzle 14 to land on the recording medium 5. Further, the ink 7 is charged by the charging unit 15 immediately after ejection.

  As shown in FIG. 2, the charging unit 15 includes two electrodes 151 and 152 attached via insulating members 153 and 154 disposed in contact with the nozzle surface. A voltage is applied between the two electrodes 151 and 152 to charge the ink installed in the ink chamber 13 while passing between the electrodes after ejection.

  Further, the rectifying member 31 provided on the upstream side in the moving direction of the recording medium 5 with respect to the inkjet head 1 is installed without leaving a gap with the inkjet head 1. The rectifying member 31 arranges and sends an air flow generated by the movement of the recording medium 5 into a space formed between the inkjet head 1 and the recording medium 5. This air flow is not a strong flow that bends the flying direction of the ink 7 that is the main droplet, but a flow that moves the charged minute ink mist 8 that is generated simultaneously with the ejection of the ink 7. The air flow after passing between the ink-jet head 1 and the recording medium 5 becomes a rising air current as shown in the figure, moves the ink mist 8 to the staying portion 41, and the ink mist 8 is collected by the collecting portion 21 made of corotron. Is done.

FIG. 3 shows a cross-sectional configuration of the collection unit 21.
The collection unit 21 as a corotron includes a casing 211, a wire 212, and a tray 213. The collection unit 21 can be pulled out from the ink jet apparatus along a depth direction (a direction perpendicular to the paper surface) in the drawing.

The ink mist 8 collected by the collecting unit 21 adheres to the inside of the housing 211 and the wire 212, and then dries and hardens. If the hardened ink (ink mist 8) is left attached, the collecting performance of the ink mist 8 is lowered, so it is necessary to scrape and remove it.
The ink that has been scraped off is dropped into the tray 213 through an opening provided in the housing 211 and collected. The tray 213 can be pulled out along the depth direction of the drawing, and the ink scraped off periodically can be discarded into a predetermined collection container. Thereby, the collection | recovery performance of the ink mist 8 as a corotron of the collection | recovery part 21 is maintainable. Note that the tray 213 and the casing 211 are not necessarily configured separately, and a part of the casing 211 may have a function as a tray.

  When the ink mist 8 remains between the inkjet head 1 and the recording medium 5, it adheres to the vicinity of the nozzle 14 and may cause problems such as nozzle clogging and ejection direction bending, but the inkjet according to the present embodiment. In the apparatus, since the ink mist 8 remaining between the inkjet head 1 and the recording medium 5 is recovered by the recovery unit 21, the occurrence of problems is prevented.

[Second Embodiment]
A second embodiment in which the present invention is suitably implemented will be described. FIG. 4 shows a cross section of the ink jet apparatus according to the present embodiment. Although it is substantially the same as that of the first embodiment, it is different in that the recovery unit 22 using the friction charging sheet 224 is provided.
The collection unit 22 includes a friction charging member 223 that winds the friction charging sheet 224 in a roll shape, charges the supply roll 221, the winding roll 222, and the friction charging sheet 224.

  The frictional charging sheet 224 is unwound from the supply roll 221, is wound around the take-up roll 222 and moves. At this time, the friction charging member 223 is brought into contact with the supply roll 221, whereby the friction charging sheet 224 is charged with the opposite charge to the ink 7. As in the first embodiment, the charged friction charging sheet 224 is attached with the ink mist 8 moved to the staying portion 41 by the rising airflow. The portion to which the ink mist 8 adheres moves to the take-up roll 222 side and is retracted, and the unused part is supplied from the supply roll 221.

  As described above, as in the first embodiment, it is possible to prevent occurrence of problems such as nozzle clogging and ink ejection direction bending.

[Third Embodiment]
A third embodiment in which the present invention is preferably implemented will be described. FIG. 5 shows a cross section of the ink jet apparatus according to the present embodiment. Although it is substantially the same as that of the first embodiment, recovery portions 21 and 23 and retention portions 41 and 42 are provided on both sides of the inkjet head 1, respectively. Further, rectifying members 31 and 32 are provided on both sides of the inkjet head 1, respectively, but these structures are not shown in FIG. 5 to be described later.

  FIG. 5A shows a case where the recording medium 5 moves in the direction of arrow A with respect to the ink jet head 1, and the ink mist 8 is removed by the collection unit 21 on the downstream side in the movement direction A of the recording medium 5. Collected. On the other hand, FIG. 5B shows a case where the recording medium 5 moves in the direction of the arrow B with respect to the ink jet head 1, and the ink mist is collected at the collection unit 23 downstream in the movement direction B of the recording medium 5. 8 is recovered.

  As described above, by providing the recovery portions on both sides of the ink jet head 1, the ink mist can be recovered regardless of which direction the recording medium moves.

  FIG. 6 shows the configuration of the rectifying member of the ink jet apparatus according to this embodiment. In the present embodiment, two rectifying members 31 and 32 are provided on both sides of the inkjet head 1, respectively. Note that. For simplification of explanation, the staying portions 41 and 42 are not shown in FIG.

FIG. 6A shows a case where the recording medium 5 moves in the direction of arrow A with respect to the inkjet head 1, and the rectifying member 31 on the upstream side in the movement direction A of the recording medium 5 is arranged at a predetermined position. ing. In this state, the rectifying member 31 sends the air flow in a space formed between the ink jet head 1 and the recording medium 5 while adjusting the air flow. On the other hand, since the downstream rectifying member 32 is retracted by rotating around the fulcrum, the air flow including the ink mist 8 forms an upward air flow on the downstream side.
FIG. 6B shows a case where the recording medium 5 moves in the direction of arrow B with respect to the inkjet head 1, and the rectifying member 32 on the upstream side in the movement direction B of the recording medium 5 is disposed at a predetermined position. ing. In this state, the rectifying member 32 arranges and sends the air flow into the space formed between the inkjet head 1 and the recording medium 5. On the other hand, since the downstream flow regulating member 31 is retracted by rotating around the fulcrum, the air flow including the ink mist 8 forms a rising air flow on the downstream side.

  FIG. 7 shows another configuration of the rectifying member of the ink jet apparatus according to the present embodiment. Similar to FIG. 6, two rectifying members 31 and 32 are provided on both sides of the inkjet head 1, respectively. The flow regulating members 31 and 32 are made of an elastic material, and can be deformed as will be described later along with the movement of the actuators 61 and 62. One ends of the rectifying members 31 and 32 are fixed to the ink chamber 13. Note that. For simplification of explanation, the staying portions 41 and 42 are not shown in FIG.

FIG. 7A shows a case where the recording medium 5 moves in the direction of arrow A with respect to the inkjet head 1, and the rectifying member 31 on the upstream side in the movement direction A of the recording medium 5 is moved downward by the actuator 61. The rectifying member 31 is pushed out and has a convex shape with respect to the ejection direction of the ink 7, and the air flow is adjusted and sent into the space formed between the inkjet head 1 and the recording medium 5. On the other hand, the rectifying member 32 on the downstream side in the moving direction A of the recording medium 5 is pulled upward by the actuator 62 and has a concave shape with respect to the ejection direction of the ink 7. The air flow containing 8 forms an updraft.
FIG. 7B shows a case where the recording medium 5 moves in the direction of arrow B with respect to the inkjet head 1, and the rectifying member 32 on the upstream side in the movement direction B of the recording medium 5 is moved downward by the actuator 62. The rectifying member 32 is pushed out and has a convex shape with respect to the ejection direction of the ink 7, and the rectifying member 32 feeds the air flow in a space formed between the inkjet head 1 and the recording medium 5. On the other hand, the rectifying member 31 on the downstream side in the moving direction B of the recording medium 5 is pulled upward by the actuator 61 and has a concave shape with respect to the ejection direction of the ink 7. The air flow containing 8 forms an updraft.

  The actuators 61 and 62 may have any configuration as long as they are elements that realize reciprocal motion, and can be configured using, for example, a solenoid.

  In this way, the air flow is rectified and the air flow containing ink mist is introduced into the staying portion by moving the flow straightening member or changing the shape in accordance with the moving direction of the recording medium. Can be done efficiently.

  Note that, here, as in the first embodiment, a configuration including a recovery unit using a corotron is taken as an example, but the same effect can be obtained even if a recovery unit using a frictionally charged sheet is used as in the second embodiment. .

  Each of the above embodiments is an example of a preferred embodiment of the present invention, and the present invention is not limited to these and can be variously modified.

DESCRIPTION OF SYMBOLS 1 Inkjet head 5 Recorded object 7 Ink 8 Ink mist 11 Piezoelectric element 12 Diaphragm 13 Ink chamber 14 Nozzle 15 Charging part 21, 22, 23 Collection | recovery part 31, 32 Rectification member 41, 42 Retention part 61, 62 Actuator 151, 152 Electrode 153, 154 Insulating member 211 Housing 212 Wire 213 Dish 221 Feed roller 222 Winding roller 223 Charging member 224 Friction charging sheet

JP 2000-263814 A

Claims (9)

An ink jet apparatus that ejects ink by an ink jet head including an ink ejecting unit that ejects and ejects ink from an ejection port, and lands on a recording medium.
Charging means for charging the ink discharged from the discharge port;
Rectifying means provided on both sides of the inkjet in the direction of movement of the recording medium with respect to the inkjet head, and rectifying means for sending an air flow in a space between the inkjet head and the recording medium;
A stay that is provided downstream of the inkjet head in the direction of movement of the recording medium and retains an air flow including ink mist that is a fine droplet of the ink after passing through a space between the inkjet head and the recording medium. Means,
Collecting means for collecting the ink mist charged by the charging means;
The rectifying means is rotatable around a fulcrum provided on a side surface of the ink jet head on the downstream side in the recording medium moving direction ,
Rectifying means of the recording member movement direction downstream side is characterized in that it is retracted to the side surface of the ink-jet head as opposing distance between the side surface of the ink jet head in the recording member moves downstream side becomes narrow Inkjet device.   2. The ink jet apparatus according to claim 1, wherein the collecting means is a corotron and generates a charge opposite to a charge charged in the ink.   3. The ink jet apparatus according to claim 2, wherein the corotron is detachably installed along a direction orthogonal to a recording medium moving direction with respect to the ink jet head.   An ink receiving member for loading ink scraped off after adhering to the corotron is provided, and the ink receiving member is detachably installed along a direction perpendicular to the recording medium moving direction with respect to the inkjet head. The inkjet apparatus according to claim 3.   The inkjet apparatus according to claim 1, wherein the collecting unit is a sheet charged to a charge opposite to that of the ink.   6. The ink jet apparatus according to claim 5, wherein the sheet is formed of a web member and is moved so as to retract an used part and supply an unused part.   The recording medium can be transported in two opposing directions, both the rectifying means provided on both sides of the ink jet head can be retracted to the ink jet head side, and both the staying means and the collecting means are The ink jet apparatus according to claim 1, wherein the ink jet apparatus is provided on both sides in a moving direction of the recording medium. The rectifying means includes a substantially flat elastic member that forms the air flow,
The elastic member is elastically deformed into a convex shape with respect to the ink discharge direction on the upstream side in the recording medium moving direction with respect to the ink jet head, and the elastic member is recessed with respect to the ink discharge direction on the downstream side. 8. The ink jet apparatus according to claim 7, wherein the ink jet apparatus is elastically deformed into a shape.   9. An image forming apparatus using the ink jet apparatus according to claim 1, wherein an image is formed on the recording medium by discharging the ink from the ink jet apparatus. Image forming apparatus.

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