The present invention relates to a liquid agent mist recovery device that is installed in a liquid agent application device for discharging the liquid agent to a sheet being carried, and is configured to allow a suction unit to introduce the liquid agent mist generated during discharge of the liquid agent into a duct for recovery. Particularly, the present invention relates to the liquid agent mist recovery device capable of preventing a droplet formed from the introduced liquid agent mist from dripping onto the sheet.
Japanese Unexamined Patent Application Publication No. 2015-134496 discloses the ink mist recovery device intended to suppress adhesion of the ink mist to the inner surface of the suction flow path. As
In the ink mist recovery device disclosed in Japanese Unexamined Patent Application Publication No. 2015-134496, as
The above-described problem of the contactless type liquid application device for discharging the liquid agent to be applied to the sheet generally involves, regardless of the purpose, the technique for sucking the liquid agent mist generated in the discharge.
The present invention has been made considering the above-described circumstances to provide a liquid agent mist recovery device that is installed in the contactless liquid agent application device for suction and recovery of the liquid agent mist. It is an object of the invention to provide the liquid agent mist recovery device capable of preventing the droplet caused by the sucked liquid agent mist from dripping onto the sheet.
The liquid agent mist recovery device according to a first aspect of the invention is provided for a liquid agent application device that allows a discharge unit to discharge a liquid agent to a sheet carried in a carrier direction. The liquid agent mist recovery device is disposed at a downstream side of the discharge unit in the carrier direction, and includes a recovery casing including an opening for introducing a liquid agent mist generated when the discharge unit discharges the liquid agent together with air, and a recovery hole communicated with the opening, and a suction unit that is connected to the recovery hole of the recovery casing, and introduces the liquid agent mist together with air from the opening. The opening is apart from an upstream wall surface and a downstream wall surface of the recovery hole by an amount equal to or larger than a width of a receiving portion for receiving the liquid agent trickling from the upstream wall surface and the downstream wall surface.
The liquid agent mist is generated when the discharge unit of the liquid agent application device discharges the liquid agent. The liquid agent mist then flows downstream. The liquid agent mist recovery device disposed at the downstream side of the liquid agent application device is capable of introducing the liquid agent mist into the recovery hole of the recovery casing with the suction force of the suction unit. The introduced liquid agent mist adheres to the wall surface of the recovery hole, and gathers thereon to trickle as the droplet. Even in the case as described above, the droplet may be received by receiving portions. This makes it possible to prevent the droplet from directly dripping onto the sheet.
An embodiment of the present invention will be described referring to
As
The inkjet printer 1 as shown in
As
As
The head unit 21 includes an inkjet head 21a as a discharge unit, a pressure tank 21b, and a negative pressure tank 21c. Each of 10 head units 21 is detachably arranged in the inkjet printer 1.
The ink IK is supplied to the negative pressure tank 21c from the ink supplying tank 24 via the sub-tank 23. The ink IK that has not been consumed by the inkjet head 21a is resupplied thereto by the circulation pump 22 via the negative pressure tank 21c and the pressure tank 21b. As described above, the print section 20 is configured as a circulation type for circulating the ink IK. However, the print section 20 may be configured as a non-circulation type.
As
The guide rollers 31a to 31j guide the continuous sheet P unwound from the unwinding unit 10 in the casing 50 in the longitudinal direction (axial direction) as the front-rear direction. The guide rollers 31a, 31b guide the continuous sheet P between the unwinding unit 10 and the meandering control unit 32. The guide rollers 31c to 31i guide the continuous sheet P between the meandering control unit 32 and the carrier roller pair 34. The guide roller 31j guides the continuous sheet P between the carrier roller pair 34 and the winding unit 40.
The meandering control unit 32 includes meandering control rollers 32a, 32b for correcting meandering of the continuous sheet P. The front-rear direction with respect to the meandering control rollers 32a, 32b corresponds to the longitudinal direction (axial direction). Based on the meandering state of the continuous sheet P detected by an unshown sensor, the meandering control unit 32 adjusts an inclination of the continuous sheet P to the front-rear direction.
Two support members 33 are disposed below each of the head units 21 in the longitudinal direction (axial direction) as the front-rear direction. Ten support members 33 disposed between the guide rollers 31d and 31e, and ten support members 33 disposed between the guide rollers 31f and 31g are arranged to form protrusive curves upward, respectively. The tensile force is applied to the continuous sheet P between the guide rollers 31d and 31e, and the guide rollers 31f and 31g, respectively to keep the stable position.
The carrier roller pair 34 is driven by an unshown motor (an example of a carrier drive unit (actuator)) to carry the continuous sheet P while being nipped.
As
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The dust remover 60 includes a dust removing unit 61 as a brush in contact with the lower surface of the continuous sheet P to remove the dust therefrom, and a tray-like dust receiving unit 62 to which the dust removing unit 61 is attached for receiving the dust removed by the dust removing unit 61 from the continuous sheet P. The dust remover 60 is movable between a cleaning position (refer to
As
The inkjet head 21a as shown in
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A reference sign L shown in
As described referring to
When the inkjet printer 1 is activated to allow the inkjet head 21a to discharge the ink to the continuous sheet P, a large quantity of fine ink mist is generated between the inkjet head 21a and the continuous sheet P. As
If there is a gap between the inkjet head 21a and the ink mist recovery device 100, the air flow containing the ink mist infiltrates into the gap to generate the ink droplet. The ink droplet then drips onto the continuous sheet P. In the embodiment, such failure hardly occurs. If the lower surfaces of the inkjet head 21a and the ink mist recovery device 100 are not continuously connected, the air turbulence such as swirling occurs in the air flow as indicated by the arrow A1, thus interfering with suction and recovery of the ink mist. In the embodiment, such failure hardly occurs. In this embodiment, the lower surface of the inkjet head 21a is flush with the lower surface of the ink mist recovery device 100. However, the lower surfaces do not have to be flush with each other. Although the lower surfaces of those components are not flush with each other, they may be regarded as being substantially continuous so long as the lower surfaces are curvedly or inclinedly continuous, or the stepped part between the lower surfaces is so small that the air current turbulence hardly occurs.
The suction force of the suction unit applied to the opening 102 generates the air current flowing from downstream to upstream as indicated by an arrow A3 in
As
According to the embodiment, the position of the opening 102 may be determined by satisfying at least two conditions as follows.
1) The opening 102 is formed at the position apart from the upstream wall surface W1 to the downstream direction by the distance corresponding to the width of the receiving portion 104 for receiving the ink droplet K trickling from the upstream wall surface W1 of the recovery hole 103. The opening 102 at the position allows introduction and recovery of the upstream ink mist, but hardly affects the upstream ink droplet required to be supplied for printing.
2) The opening 102 is formed at the position apart from the downstream wall surface W2 of the recovery hole 103 to the upstream direction so that the downstream suction air (arrows A3, A4) generates the air flow that obstructs the upstream ink mist flow, and blows the ink mist flow upward (arrow A2) for guiding into the recovery hole 103.
In the embodiment, the opening 102 is formed at substantially the center part of the ink mist recovery device 100 in the carrier direction F in consideration of the position of the adjacent inkjet head 21a at the upstream side, the position of the inkjet head 21a of the other head unit 21 at the downstream side, and the suction force of the suction unit so that the positional conditions are satisfied. The downstream suction air current flowing to the upstream direction serves to obstruct the ink mist flowing from upstream for guiding into the recovery hole 103 without affecting the operation for discharging the ink droplet to form the image. The ink mist is then introduced into the recovery hole 103 from the opening 102 together with air rather than flowing downward, and accordingly, securely recovered. Even if the ink mist introduced into the recovery hole 103 of the recovery casing 101 adheres to the wall surfaces W1, W2, and gathers thereon to trickle down as the ink droplet K, the receiving portions 104, 105 receive the ink droplet K. This makes it possible to prevent the ink droplet from dripping directly onto the continuous sheet P.
A modified example of the ink mist recovery device 100 installed in the inkjet printer according to the embodiment will be described referring to
As
A specific effect of the inkjet printer 1 according to the embodiment will be described.
The inkjet printer 1 according to the embodiment has functions of unwinding and carrying the continuous sheet wound in the roll state (roll sheet) from the sheet feeder, printing a desired image on the sheet by the inkjet head, and winding the printed continuous sheet around the winding unit. Since the inkjet head used herein is a printing unit of contactless type for forming the image by discharging ink droplets onto the sheet, the ink mist is inevitably generated in printing. In the printer as described above, downward movement of the floating ink mist is obstructed by the continuous roll sheet. It is therefore necessary to install the ink mist recovery device for recovering the ink mist that has nowhere to go.
Even in the use of the suction type carrier device as the one for carrying the sheet while having the sheet stuck on the belt, the continuous belt-like roll sheet is carried to cover a major part of the suction hole of the belt for the air suction operation continuously. Therefore, it is unlikely that the ink mist floating above the roll sheet is sucked through the suction hole of the belt and removed. If the width of the roll sheet is smaller than that of the belt and the suction holes are opened at both ends of the belt in the width direction, the ink mist may be partially sucked through the suction hole. In the above-described condition, however, the ink mist floating above the sheet cannot be sufficiently recovered.
Accordingly, in the printer of type using the inkjet head to form the image on the roll sheet, unless the ink mist generated in printing is recovered immediately after printing, the downstream side may be affected. It is therefore preferable to dispose the ink mist recovery device close behind the downstream side of the inkjet head in the roll sheet carrier direction. In the inkjet printer 1 according to the embodiment, the ink mist recovery device is disposed close behind the downstream side of the inkjet head. As described above, even in the case where the liquid agent mist introduced into the recovery hole of the recovery casing adheres to the wall surface of the recovery hole, and gathers thereon to trickle as the droplet, the receiving portions receive the droplet to prevent dripping onto the sheet.
In the case of the printer of type using the inkjet head for forming the image on the cut sheet carried by the suction type carrier device unlike the inkjet printer 1 of the embodiment, the gap exists between the adjacent sheets while being carried. The gap exposes the suction hole formed in the belt for the air suction operation. Therefore, the ink mist floating above the sheet is expected to be sucked to a certain extent from the suction hole of the belt.
In the above-described embodiment, the inkjet printer 1 provided with the ink mist recovery device 100 has been explained. However, the ink mist recovery device 100 is only an example of the liquid agent mist recovery device according to the present invention. In addition to the exemplary case of the embodiment, the liquid agent mist recovery device according to the present invention is applicable to the pre-treatment liquid mist recovery device disposed in the sheet pre-treatment device, and the post-treatment liquid mist recovery device disposed in the post-treatment device for the printed sheet.
The sheet pre-treatment device is disposed at the upstream side of the print section of the inkjet printer as described above, and configured to apply the pre-treatment liquid to the sheet in the contactless manner. Execution of the pre-treatment may prevent the ink from being blurred as a result of infiltration into the sheet, and further improve fixing of the ink.
The sheet post-treatment device is disposed at the downstream side of the print section of the inkjet printer as described above, and configured to apply the post-treatment liquid to the printed sheet in the contactless manner. Execution of the post-treatment process may protect the newly formed image from being damaged owing to rubbing. It is also possible to make the image shiny for improving the appearance, and to further make the image stereoscopic by applying the post-treatment liquid only to the part where the image is formed.
Structure and Effect of Liquid Agent Mist Recovery Device According to Invention
The liquid agent mist recovery device according to a first aspect of the invention is provided for a liquid agent application device that allows a discharge unit to discharge a liquid agent to a sheet carried in a carrier direction. The liquid agent mist recovery device is disposed at a downstream side of the discharge unit in the carrier direction, and includes a recovery casing including an opening for introducing a liquid agent mist generated when the discharge unit discharges the liquid agent together with air, and a recovery hole communicated with the opening, and a suction unit that is connected to the recovery hole of the recovery casing, and introduces the liquid agent mist together with air from the opening. The opening is apart from an upstream wall surface and a downstream wall surface of the recovery hole by an amount equal to or larger than a width of a receiving portion for receiving the liquid agent trickling from the upstream wall surface and the downstream wall surface.
In the liquid agent mist recovery device according to the first aspect, the liquid agent mist is generated upon discharging of the liquid agent from the discharge unit of the liquid agent application device, and then flows downstream. The liquid agent mist recovery device disposed at the downstream side of the liquid agent application device is capable of introducing the liquid agent mist into the recovery hole of the recovery casing with the suction force of the suction unit. Even if the introduced liquid agent mist adheres to the wall surface of the recovery hole, and gathers thereon to trickle as the droplet, the receiving portions receive the droplet. This makes it possible to prevent the droplet from directly dripping onto the sheet.
In the liquid agent mist recovery device according to a second aspect of the invention, the opening is apart from the downstream wall surface of the recovery hole to allow the air introduced from downstream side to obstruct the upstream liquid agent mist for guiding into the recovery hole.
In the liquid agent mist recovery device according to the second aspect, the air current to the upstream direction, which has been generated by air introduced from downstream by the liquid agent mist recovery device obstructs the liquid agent mist flowing from upstream for guiding into the recovery hole. The liquid agent mist flowing from upstream may be securely introduced into the recovery hole from the opening of the recovery casing with the suction force of the suction unit for recovery.
In the liquid agent mist recovery device according to a third aspect of the invention, a lower surface of the discharge unit that faces a sheet is continuous with a lower surface of the recovery casing.
In the liquid agent mist recovery device according to the third aspect, the air flows from the discharge unit to the liquid agent mist recovery device along the continuous lower surfaces of the discharge unit and the liquid agent mist recovery device. The air flow is brought into a stable linear flow to directly carry the liquid agent mist to the opening without generating a swirl that interferes with smooth transfer of the liquid agent mist.
Number | Date | Country | Kind |
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JP2019-028039 | Feb 2019 | JP | national |
Number | Name | Date | Kind |
---|---|---|---|
9315037 | Gasso Puchal | Apr 2016 | B2 |
20130229460 | Masuda | Sep 2013 | A1 |
20140240397 | Norihiro | Aug 2014 | A1 |
20150085014 | Ishida et al. | Mar 2015 | A1 |
20150165770 | Miyakoshi et al. | Jun 2015 | A1 |
20160031218 | Ishida et al. | Feb 2016 | A1 |
20190009567 | Miyakoshi et al. | Jan 2019 | A1 |
Number | Date | Country |
---|---|---|
3 072 694 | Sep 2016 | EP |
3 072 694 | Dec 2016 | EP |
3 290 212 | Mar 2018 | EP |
2015-134496 | Jul 2015 | JP |
Entry |
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European Search Report, European Patent Office, Application No. 20158529.6, dated Jun. 24, 2020. |
Number | Date | Country | |
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20200262207 A1 | Aug 2020 | US |