JP2012096513A - Inkjet recorder and printing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inkjet recorder which achieves high speed printing and low power consumption and in addition, has improved rise-up characteristics and is efficiently operated.SOLUTION: The inkjet recorder forming an image by ejecting ink onto paper 10 by an inkjet head 110, includes: a chamber 412 which is provided in a conveyance path 111 for the paper 10 and downstream of the inkjet head 110 and dries the printed paper 10; and a paper drying device 400 which has a heat pump 406 for separating moisture in a circulating gas, thereby converting the gas to high-temperature dried gas, and circulates the gas within the chamber 412. In the inkjet recorder, water separated by the heat pump 406 is supplied to the front side of the inkjet head 110, and the front side is put into humidified atmosphere and thereby the inkjet head 110 is prevented from drying.

Description

  The present invention relates to an ink jet recording apparatus and a printing method, and in particular, forms (prints) an image on a sheet-like recording medium such as papers, cloths, films, and synthetic resin materials wound around a roll by an ink jet method. The present invention relates to a copying machine, a printer, a facsimile, a digital multifunction machine having these functions combined, an ink jet recording apparatus including an image forming apparatus such as a printing machine, and a printing method executed by the ink jet recording apparatus.

  An ink jet recording apparatus ejects ink droplets onto a recording medium by an ink jet head, penetrates the recording medium, or adheres to the surface of the recording medium to form an image or print. As described above, since the ink jet recording apparatus uses ink droplets, the atmosphere of the printing portion becomes a high humidity environment, and not only the printing portion of the sheet-like recording medium but also the recording medium itself is damp.

  On the other hand, in an ink jet recording apparatus that performs high-speed printing, continuous paper (paper) wound in a roll shape is often drawn out and printed, and then wound in a roll shape. Therefore, the paper is dried before winding. It is necessary to keep. Otherwise, dirt, fading, blurring and the like due to adhesion of the printed ink may occur, and winding may be hindered. Therefore, a method for drying the sheet-like recording medium is important.

  Therefore, although not an ink jet recording apparatus, as an example of a drying method, Patent Document 1 (Japanese Patent Application Laid-Open No. 2006-169710) discloses heat pump-type dehumidification when recycling used paper shredded by a document shredder. A waste paper recycling apparatus for document shredded waste using a dryer from a dryer is described.

  Japanese Patent Laid-Open No. 2010-125828 discloses a drying unit that dries ink on a recording medium and an ink head to sufficiently dehumidify air and perform ink drying during recording. An ink jet recording apparatus is described that includes a dew condensation unit that condenses moisture in the air, a cooling unit that cools the dew condensation unit, and a water droplet collection unit that collects moisture by dew condensation at the dew condensation unit by cooling. .

  However, the invention described in the cited document 1 discloses that the atmosphere in the drying chamber of the dry part of the paper machine that disintegrates the waste paper shredded by the document shredder and produces the regenerated paper from the regenerated pulp suspension. The dehumidifying dryer that dehumidifies and drys the printer has a heat pump dryer and is not used for drying printing paper. It is used for drying sheet-like recording media in high-speed inkjet recording devices. It is not possible. The heat pump dryer is merely a drying means used for making recycled paper, and no other uses are considered.

  In the invention described in the cited document 2, the atmosphere on the front surface of the ink head becomes high humidity due to ink ejection, and when the ink is stacked and ejected, a problem called bleeding occurs when the recording medium is not sufficiently dried. In order to improve this, the front surface of the ink head is dehumidified. The cooling means and water droplet recovery means in this invention only recovers the water droplets generated by dehumidification and dehumidification, and only the recovered water and water droplets are discarded.

  In any case, in the inventions described in Cited Documents 1 and 2, nothing is considered about the reuse of water and water droplets collected after drying.

  On the other hand, in the ink jet recording apparatus, it is necessary to dry the recording medium. However, when the ink is dried, problems such as ink fixation and ink clogging occur. That is, in an ink jet recording apparatus, when printing a narrow paper, an ink jet head located in a portion not to be printed outside from the width direction of the paper does not eject ink. Thus, an operation called idle ejection for ejecting ink is performed. Thus, ink is passed before the ink is fixed at the nozzle portion of the ink head so that the ink is not fixed.

  In order to execute this operation, the ink jet recording apparatus is provided with a tray called an idle discharge receiver that receives the idle ink. When the front surface of the head is in a dry atmosphere, the inkjet head is easily dried. On the other hand, when the front surface of the head is in a humid atmosphere, it becomes difficult for the ink to dry, and therefore, ink clogging hardly occurs. This means that when the front surface of the head is in a humid atmosphere, the ink ejection timing can be made longer than in the dry atmosphere.

  On the other hand, a cap for covering the inkjet head is provided to prevent the ink from sticking. The cap is removed at the time of printing and is attached after printing. However, simply by capping, the inside of the cap is not in a humid state, so that drying cannot be reliably prevented. For this reason, it is desirable to prevent the ink jet head from actively drying.

  As described above, since the function around the head may be impaired when dried around the head, it is desirable to perform moisture retention or humidification regardless of whether it is a cap or an empty discharge receptacle, and a humidifier may be provided separately as an external device. However, when a humidifier is provided as an external device, the cost for that and the energy for driving the humidifier are further required, and there is room for improvement from the viewpoint of energy saving and low cost.

  Therefore, a problem to be solved by the present invention is to efficiently prevent drying of the ink jet head and improve ejection reliability without separately installing a humidifying device as an external device.

  In order to solve the above-described problem, the first means is an ink jet recording apparatus that forms an image by ejecting ink from a recording head onto a recording medium, wherein the recording head in the conveyance path of the recording medium A paper drying apparatus that is provided on the downstream side and has a drying chamber that dries the recording medium, and a heat pump that separates moisture in the circulating gas into a high-temperature drying gas, and circulates the gas in the drying chamber. And a drying prevention means for supplying water separated by the heat pump to the front side of the recording head and making the front side a humid atmosphere to prevent drying of the recording head. .

  The second means is the first means in which the drying preventing means is provided at a position facing the recording head with the recording medium sandwiched during printing, and is used to prevent ink clogging of the recording head. An empty discharge receiver that receives ink and a supply unit that supplies water separated by the heat pump to the empty discharge receiver.

  According to a third means, in the first or second means, the drying prevention means includes a cap portion that covers the recording head during non-printing, and a supply means that supplies water separated by the heat pump to the cap portion. It is characterized by having.

  According to a fourth means, in the first or second means, the drying preventing means covers a cap portion that covers the recording head at the time of non-printing, and a gas containing moisture separated from the recording medium in the drying chamber. And a branch pipe leading to the section.

  According to a fifth means, in the fourth means, the detection means for detecting the humidity of the gas containing water, the opening / closing means for opening and closing the branch pipe, and the humidity detected by the detection means are preset. Control means for opening the branch pipe by the opening / closing means and supplying the gas containing moisture to the cap portion when the humidity becomes higher.

  A sixth means is characterized in that, in any one of the first to fifth means, the separated water is taken out from a drain of the heat pump.

  A seventh means is a printing method of an ink jet recording apparatus that forms an image by ejecting ink from a recording head to a recording medium, and is provided on the downstream side of the recording head in the conveyance path of the recording medium. The recording medium is dried in a drying chamber, the moisture transferred into the gas circulated by drying in the drying chamber is separated by a heat pump, and the condensed water is supplied to the front side of the recording head. The front side is humidified to prevent the recording head from drying.

  According to an eighth means, in the seventh means, the front side that becomes the humidified atmosphere is provided at a position facing the recording head across the recording medium during printing, and prevents ink clogging of the recording head. It is an idle discharge receiver that receives the empty ink.

  A ninth means is characterized in that, in the seventh means, the front surface side in which the humidified atmosphere is provided is a cap portion that covers the recording head during non-printing.

  In the embodiment described later, the recording head is the inkjet head 110, the recording medium is the paper 10, the inkjet recording apparatus is the inkjet apparatus 1, the transport path is the reference numeral 111, the drying chamber is the chamber 412, and the heat pump is Reference numeral 406, a sheet drying apparatus 400, an empty discharge receiver 510, a cap part to the cap 112 and the cap chamber 113, and a supply means drain 501, drain tank 505, pump 507, drain flow paths 502, 512 Further, the branch pipe line corresponds to the cap air blowing path 551, the opening / closing means corresponds to the flow path opening valve 552, and the detection means corresponds to the humidity sensor 405.

  According to the present invention, since moisture retention of the inkjet head is performed using moisture separated by a heat pump in its own system, it is possible to prevent drying of the inkjet head without the need to provide a humidifier as an external device. Since the drying can be prevented, the ejection reliability of the inkjet head can be improved.

It is a figure which shows the system configuration | structure of the whole inkjet apparatus which concerns on Example 1 in embodiment of this invention. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic configuration diagram of an ink jet apparatus according to a first embodiment viewed from the front. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic configuration diagram of an inkjet device according to Example 1 as viewed from the back side. It is a schematic block diagram which shows the function structure of a heat pump. FIG. 3 is a right side view of the ink jet apparatus of FIG. 2 and shows a state when the ink jet head is moved to a printing position. The state after the inkjet head 110 moved to the non-printing position from the state of FIG. 5 is shown. FIG. 4 is a diagram illustrating a state where water is supplied only into a cap chamber and an empty discharge receiver has only an ink recovery function, and the inkjet head has moved to a printing position. It is a figure which shows a state when water is supplied only into the cap chamber and the empty discharge receiver has only an ink recovery function and the inkjet head has moved to a non-printing position. FIG. 5 is an example in which water is supplied only into an empty discharge receiver and a cap chamber is not provided with a water supply mechanism and an ink jet head is covered, and is a diagram illustrating a state when the ink jet head is moved to a printing position. It is an example which covers an ink jet head without supplying a water supply mechanism to a cap discharge chamber, and shows a state when the ink jet head has moved to a non-printing position. FIG. 5 is a schematic configuration diagram of an ink jet apparatus according to a second embodiment viewed from the front. It is a figure which shows the state which has an inkjet head in a printing position by the right view of FIG. It is a figure which shows the state which has an inkjet head in a non-printing position by the right view of FIG. 6 is a block diagram illustrating a control configuration of an ink jet apparatus according to Embodiment 2. FIG.

  The present invention is characterized in that moisture separated by a heat pump is used to prevent drying of the inkjet head, thereby enabling drying of the inkjet head without providing a separate humidifier as an external device. . Hereinafter, embodiments of the present invention will be described for each example with reference to the drawings.

  FIG. 1 is a diagram showing the overall system configuration of an ink jet recording apparatus (hereinafter also referred to as an ink jet apparatus) according to Example 1 of the present embodiment. In FIG. 1, the system according to the first embodiment is basically composed of an ink jet device 1, a paper feeding device (unwinder) 2, and a winding device (rewinder) 3. The paper feeding device 2, the ink jet device 1, and the winding device 3 are arranged on a straight line in this order along the paper transport direction. In the first embodiment, these devices are juxtaposed on the same level floor surface by wheels 40 provided on the lower surface.

  The paper feeder 2 supplies the roll paper 21 continuously wound around the roll to the ink jet apparatus 1 side while pulling it out. The winding device 3 winds the paper 10 printed by the inkjet device 1 on a roll, winds up all the sheet members to form a roll paper 31, removes the rolled paper 31 and sends it to the subsequent process. Here, the paper 10 is simply referred to as the paper 10, but the paper 10 is a continuous paper wound around a roll. Here, the paper 10 means a continuous paper. In the first embodiment, the paper 10 is representatively exemplified as one of the sheet-like recording media, and the paper 10 is the above-described papers, cloths, films, and composites used as the recording media. It can be spread on a sheet-like member made of a resin material.

  The ink jet device 1 includes an ink jet image forming unit 100 including an ink jet head, and an ink jet image forming unit 100 that is on the upstream side (front stage) of the ink jet image forming unit 100 in the paper transport direction and feeds the paper 10 fed from the paper feed device 2. And an outfeed unit 300 for sending the paper 10 printed by the inkjet image forming unit 100 to the winding device 3 side.

  FIG. 2 is a schematic configuration diagram of the inkjet device 1 according to the first embodiment when viewed from the front, and FIG. 3 is a schematic configuration diagram when viewed from the back side. In these drawings, the infeed unit 200 includes a plurality of guide rollers 210, an infeed roller 220, a nip roller 230, and the like, and draws continuous paper from the paper feed device 2 from a paper feed port 201 formed on the side of the infeed unit 200. . In the infeed unit 200, the sheet 10 is guided from the guide roller 210 to the nip between the infeed roller 220 and the nip roller 230, and the sheet 10 is fed into the inkjet image forming unit 100 with a predetermined tension applied by the plurality of guide rollers 210.

  The ink jet image forming unit 100 includes an ink jet head 110 and a control unit 120 described later, and executes image forming and paper feed control for the paper 10 based on an instruction from the host device 130. The inkjet head 110 is disposed at a position facing the paper conveyance path 111, and ejects ink droplets onto the paper 10 that is conveyed at high speed, thereby forming a print image on the paper 10. A paper drying device 400 having a heat pump 406 is further installed on the front surface side of the ink jet image forming unit 100, and a ventilation path that returns from the outlet 401 of the heat pump 406 through the outfeed unit 300 to the heat pump 406 through the suction port 402. 410a and 410b are provided. The upstream air passage 410a includes an upstream first duct 411, a drying chamber (hereinafter referred to as “chamber”) 412, a downstream second duct 413, and a downstream air passage 410b. A conveyance path for the sheet 10 is formed in 412.

  The chamber 412 is disposed on the downstream side of the conveyance path 111 facing the inkjet head 110, and high-temperature dry air blown from the heat pump 406 is supplied to the space above the printing surface of the paper 10. As a result, the high-temperature dry air comes into contact with the surface of the paper and can dry and dehumidify the paper 10. Further, as will be described later, in this embodiment, a water supply device 500 is provided to supply water guided from the drain 501 of the heat pump 406 to the cap chamber 113 and the empty discharge receiver 510 constituting the cap 112 of the inkjet head 110, respectively. Yes.

  In the outfeed unit 300, a plurality of guide rollers 310 including a guide roller 310 for allowing the paper 10 to pass through the chamber 412 is installed, and is provided on the most downstream side in the paper conveyance direction in the outfeed unit 300. Further, a conveying force is applied by the outfeed roller 320 and the nip roller 330, passes through the last-stage guide roller 310, is sent from the paper discharge port 340 to the winding device 3 side, and is wound in a roll shape by the winding device 3. In the first embodiment, the printing process is performed on the continuous paper from the leading end of the roll of the sheet feeding device 2 to the trailing end of the roll wound by the winding device 3 in this way.

  FIG. 4 is a schematic configuration diagram showing a functional configuration of the heat pump. The heat pump 406 is a heat pump using a heat medium, and includes a blower 420, heat exchangers 430 and 440 on a cooling side and a heating side, a compressor 450, and a decompressor 460, each of which includes an outlet 401 and an inlet 402. It is housed in the formed case 470. In addition, the cooling-side heat exchanger 430, the decompressor 460, the heating-side heat exchanger 440, and the compressor 450 are connected by a medium pipe 403 therebetween to form a closed circulation pipe. The heat medium circulates in the direction of the arrow D3 in the figure, and the high-temperature dry air supplied to the chamber 412 circulates in the direction of the arrow D4 in the figure.

  The blower 420 is a drive source of the warm air supplied to the chamber 412, and is disposed between the cooling-side heat exchanger 430 and the heating-side heat exchanger 440, and returns-side humid air sucked from the suction port 402. Aw is sent from the heat exchanger 430 on the cooling side to the heat exchanger 440 on the heating side, and sent out from the outlet 401 as high-temperature dry air Ah heated to a predetermined temperature by the heat exchanger 440 on the heating side. The heat medium of the heat pump 406 is depressurized by the decompressor 460, becomes lower than the ambient temperature, and is sent to the heat exchanger 430 on the cooling side. Then, the heat exchanger 430 on the cooling side is cooled, and the moisture-containing air (warm air) Aw sucked from the suction port 402 is separated into water droplets 409 and dry air.

  The water droplet 409 gradually becomes a large water pool due to the surface tension, accumulates on the inner bottom surface of the case 470, and is guided from the drain 501 provided on the bottom surface of the case to the drain tank 505. Then, the water in the drain tank 505 is sucked up by the pump 507, guided to the cap 112 and the empty discharge receiver 510 through the drain flow paths 502 and 512, respectively, and stored in the cap chamber 113 and the empty discharge receiver 510. Is done. The stored water 503 and 513 are guided to the waste liquid tank 506 from the drainage channels 504 and 514 when they reach predetermined water levels in the cap chamber 113 and the empty discharge receptacle 510, respectively, and are stored in the waste liquid tank 506 and stored in a predetermined amount. Discarded when stored.

  In FIG. 4, the drain 501 has come out from the drain 501 under the case 470, but this is a conceptual illustration of the schematic configuration of the heat pump 406, and the actual machine is shown in FIGS. 2 and 3. As described above, these units are installed in the sheet drying apparatus 400 and led out from the main body of the sheet drying apparatus 400.

  On the other hand, the heat medium that has passed through the heat exchanger 430 on the cooling side is sent to the compressor 450 side, and is compressed by the compressor 450 to become a high temperature. The heat medium having reached a high temperature is sent to the heat exchanger 440 on the heating side, exchanges heat with the air dehumidified by the heat exchanger 430 on the cooling side, and sent to the decompressor 460. On the other hand, the air that has passed through the heat exchange 440 on the heating side becomes high-temperature dry air Ah as described above, and is sent out from the outlet 401 to the blower path 410a.

  That is, the heat pump 406 exchanges heat with the air circulating through the air flow paths 410 a and 410 b in the process of repeatedly absorbing and radiating heat by repeatedly expanding and compressing the heat medium, deprives the paper 10 of moisture, and absorbs moisture from the suction port 402. Aw is introduced to the heat pump 406 side as the Aw, the moisture is removed from the humid air Aw by the heat pump 406, and the amount of heat sufficient to dry the paper 10 is supplied to the warm air. Send out as.

  In addition, since the heat exchange principle of a heat pump and a heat pump is a well-known technique, detailed description is abbreviate | omitted here. In addition, since the heat exchange capacity and the air blowing capacity of the heat pump should be set as appropriate according to the equipment to be heat exchanged, the description thereof is also omitted here.

  In this manner, the high-temperature dry air Ah is supplied from the blower outlet 401 to the upstream air passage 410 a and the first duct 411 into the chamber 412 by the blower 420 of the heat pump 406, and the paper 10 is dried in the chamber 412. Thereafter, the moisture-containing air Aw is collected from the suction port 402 via the second duct 413 and the downstream air passage 410b, and the collected moisture-containing air Aw is sent again as high-temperature dry air Ah by the heat pump 406. By repeating the process, the paper 10 can be dried under high-speed printing. The high-speed printing referred to here is assumed to be printing at a conveyance speed of, for example, 75 m / min to 150 m / min.

  At that time, as shown in FIGS. 2 and 3, the paper 10 is conveyed along the chamber 412, and the high-temperature dry air Ah moves on the printing surface side of the paper 10 at a predetermined relative speed and is included in the paper 10. Moisture is transferred into the hot dry air Ah. In the present embodiment, the high-temperature dry air Ah is blown at a speed sufficiently higher than the paper transport speed (printing speed) in the same direction as the paper transport direction. A sufficiently high speed means that the transfer of moisture from the sheet 10 into the high-temperature dry air Ah maintains an equilibrium state, and the sheet 10 can replace the air layer on the sheet surface without reaching the saturated water vapor amount. It is preferable that the speed be a relative speed.

  FIG. 5 is a right side view of the ink jet apparatus 1 of FIG. 2, in which the ink jet head 110 moves to the printing position, partially breaks the outfeed roller 320 and the guide roller 310, and the chamber 412 and the air flow paths 410a and 410b. The arrangement state is shown.

  As can be seen from FIG. 5, a paper drying device 400 provided with a heat pump 406 is disposed in front of the inkjet image forming unit 100, and the paper drying device 400 blows air from the outlet 401 of the heat pump 406 as shown in FIG. 2 described above. The high-temperature dry air is guided to the upstream air passage 410a, supplied to the chamber 412 in the outfoot unit 300, and returns from the chamber 412 to the heat pump 406 through the downstream air passage 410b.

  The high-temperature dry air Ah deprived of moisture from the paper 10 is guided from the downstream side of the final stage guide roller 310a to the blower path 410b and returns into the heat pump 406. In the present embodiment, the first and second ducts 411 and 413 are singular on the discharge side and the suction side, respectively. However, the flow velocity distribution in the chamber 412 is made uniform on each side in parallel. Needless to say, a plurality of them may be provided side by side in the position, which increases the circulation efficiency of the hot air. The examples shown in FIGS. 1 to 5 are examples in which warm air is sent in the same direction (forward direction) as the paper 10 as indicated by an arrow D1 (FIG. 2).

  While the paper 10 is dried in this manner, the water droplets 409 separated from the moisture-containing air Aw are guided to the drain tank 505 by the drain 501 and appropriately supplied into the cap chamber 113 via the drain channel 502 ( 2), when the inkjet head 110 is in the printing position, the cap 112 is opened, and even if water is supplied from the drain 501 to the cap 112, it evaporates. Therefore, the cap shutter 114 is installed on the upper surface of the cap chamber 113 so that it can be opened and closed. When the inkjet head 110 is in the printing position, the upper surface of the cap chamber 113 is closed by the cap shutter 114, and the water in the cap chamber 113 is closed. Evaporation is prevented.

  On the other hand, the empty discharge receptacle 510 side is also supplied from the drain tank 505 to the empty discharge receptacle 510 as appropriate through the drain channel 512 (see FIG. 3). As shown in FIG. 5, when the paper 10 is narrow with respect to the print width of the inkjet head 110 as shown in FIG. 5, the idle ejection receiver 510 does not eject the paper 10 at a preset timing. Ink 520 is ejected from the inkjet head 110 at the position to prevent ink clogging. The ink 520 is driven into the water storage in the empty discharge receiver 510 and drained from the drainage channel 514 into the waste liquid tank 506 at a predetermined water level. Since the ink 520 discharged in this manner is dissolved in the water stored in the empty discharge receiver 510, the dry ink is fixed to the empty discharge receiver 510 and does not accumulate. Further, it is not necessary to discharge extra ink 520 so as not to accumulate.

  FIG. 6 shows a state after the inkjet head 110 has moved to the non-printing position from the state of FIG. In this state, the inkjet head 110 is moved from the printing position in FIG. 5 to the front side of the apparatus and is covered with the cap 112. In this case, the front surface (ink discharge side) of the inkjet head 110 is covered by the cap chamber 113, and the ink discharge side of the inkjet head 110 is located in a humidified atmosphere. Even in this state, water from the drain 501 of the heat pump 406 is appropriately supplied into the cap chamber 113 and drained as appropriate. At that time, water from the drain tank 505 is also appropriately supplied to the empty discharge receptacle 510 and drained as appropriate. The water stored in the idle discharge receiver 510 does not have to be in a humidified atmosphere when the ink jet head 110 is positioned on the idle discharge receiver 510 side. The upper surface is an open space.

  In this embodiment, the water supply device 500 includes a heat exchanger 430 on the cooling side of the heat pump 406, a drain 501, a drain pump 507, drain channels 502 and 512, a cap chamber 113, an empty discharge receptacle 510, and a drain channel 504. 514, and a waste liquid tank 505.

Thus, in this embodiment,
(1) Water from the drain 501 of the heat pump 406 is introduced into the cap chamber 113 and the empty discharge receptacle 510 provided at the non-printing position of the inkjet head 110. In the cap chamber 113, the inkjet head 110 is positioned at the non-printing position. Since the front surface of the ink discharge port is set to a humidified atmosphere, the inkjet head 110 at the time of cap can be reliably moisturized.
(2) When the inkjet head 110 is positioned at the printing position, the ink 520 that is ejected idle is received by the water stored in the idle ejection receiver 510 during the idle ejection when printing on narrow paper. In addition to preventing ink sticking at 510, the ink-jet head 110 can be moisturized during printing (decap state), and the ejection reliability can be improved.
(3) Since the ink-jet head 110 can be moisturized, the frequency of idle ejection can be reduced, thereby reducing the amount of wasted ink used.
(4) Since the water aggregated by the heat pump 406 in the self system is used as the water supply in the cap chamber 113 and the empty discharge receiver 510, the discharge reliability of the inkjet head 110 can be improved at low cost.
There are effects such as.

  In this embodiment, water is supplied to each of the cap chamber 113 and the empty discharge receptacle 510, but water is supplied only to the cap chamber 113 as shown in FIGS. As described above, only the ink recovery function may be provided. Further, as shown in FIGS. 9 and 10, water is supplied only to the empty discharge receptacle 510, and the cap 112 is configured in consideration of hermeticity with the inkjet head 110 without providing a water supply mechanism in the cap chamber 113. You can also. Although it is a design problem and it does not specifically limit which water supply mechanism is provided, of course, it goes without saying that it is best to provide both.

  In this second embodiment, instead of supplying water into the cap chamber 113 of the first embodiment, moisture-containing air obtained by paper drying is introduced into the cap chamber 113 to suppress drying of the inkjet head 110. .

  FIG. 11 is a schematic configuration diagram of the inkjet apparatus 1 according to the second embodiment as viewed from the front, FIG. 12 is a right side view of FIG. 11 and the inkjet head is in a printing position, and FIG. A state where the inkjet head is in a non-printing position is shown. In the present embodiment, the water supply device to the empty discharge receptacle 510 side is not particularly illustrated, but water from the drain 501 of the heat pump 406 can be guided to the empty discharge receptacle 510 and stored as in the first embodiment. It is like that. In addition, the same reference numerals are given to the same components as those in the first embodiment, and a duplicate description will be omitted as appropriate.

  In FIG. 11, a humidity sensor 405 is provided inside the second duct 413, and the detection output of the humidity sensor 405 is input to the control unit 120 described later. Further, a cap air supply path 551 branches off from the air supply path 410 b on the downstream side of the second duct 413, so that the humid air in the air supply path 410 b can be introduced into the cap chamber 113. A flow path opening valve 552 is provided downstream of the branch portion of the cap air supply path 551, and the cap air supply path 551 is opened and closed. This opening / closing operation is controlled by the control unit 120 according to the detection output of the humidity sensor 405. In the present embodiment, when the humidity of the moisture-containing gas Aw downstream of the chamber 412 detected by the humidity sensor 405 exceeds 60%, the humidity is released and partly branched and guided into the cap chamber 113. Thereby, the inside of the cap chamber 113 becomes a humidified atmosphere with a humidity of 60% or more. In the cap chamber 113, condensation occurs because the temperature becomes lower than that of the air passage 410b before branching, but the condensed water is collected from the drainage channel 502 to the waste liquid tank 506.

  Other parts not specifically described are configured in the same manner as in the first embodiment and function in the same manner.

  FIG. 14 is a block diagram illustrating a control configuration of the ink jet apparatus including the heat pump according to the second embodiment. In the figure, the inkjet apparatus 1 includes a control unit 120 that is communicably connected to a host device 130. The control unit 120 includes a decompressor / compressor control unit 121, a blower control unit 122, an operation panel 140, A motor driver 124 for driving and controlling the data storage unit 123, the decompressor 460 and the compressor 450, and a motor driver 125 for driving and controlling the blower 420 are connected. In addition, the detection output from the humidity sensor 405 that detects the humidity in the chamber 412 described above is input to the decompressor / compressor control unit 121, the blower control unit 122, and the control unit 120. As a result, each of the control units 121 and 122 acquires humidity information based on the amount of water evaporated from the paper 10 and transferred into the warm air, and outputs the control information to the control unit 120 of the inkjet apparatus 1. The control unit 120 of the ink jet apparatus 1 refers to the control data for paper drying control stored in the data storage unit 123 and passes through the motor drivers 124 and 125 based on the control information from the control units 121 and 122. The decompressor 460, the compressor 450, and the blower 420 are controlled.

  Further, the control unit 120 receives the detection output of the humidity sensor 405, and when the detection output exceeds 60% humidity, the control unit 120 opens the flow path control valve 552 via the motor driver 553, and 60% When it becomes below, the flow path control valve 552 is closed. Since the type of the driver varies depending on the method of the flow control valve 552, the method of the flow control valve 552 and the method of the driving means associated therewith are not limited to the embodiments.

  The operation panel 140 is a user interface, and includes keys for initial setting by the user, keys for setting various modes, keys for instructing operations, and the like.

  The control unit 120, the decompressor / compressor control unit 121, and the blower control unit 122 each include a CPU, a ROM, and a RAM. For each of the control units 120, 121, and 122, the CPU stores a program code stored in the ROM. The program code read out is expanded in the RAM, and the control defined by the program code is executed while using the RAM as a work area and a data buffer.

  As described above, according to the present embodiment, in order to prevent the inside of the cap chamber 113 from being dried, the cap air flow path 551 is branched from the air flow path 410b on the return side, and the flow path according to the humidity of the humid air Aw. Since it is only necessary to open and close the release valve 552, the same effect as that of the first embodiment can be achieved at a lower cost than the first embodiment.

  The present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the gist of the present invention, and all technical matters included in the technical idea described in the claims are included. The subject of the present invention. Each of the above-described embodiments is a preferable example, but those skilled in the art can realize various alternatives, modifications, variations, and improvements from the contents disclosed in this specification. And are within the scope defined by the appended claims.

DESCRIPTION OF SYMBOLS 1 Inkjet apparatus 10 Paper 110 Inkjet head 111 Conveyance path 112 Cap 113 Cap chamber 400 Paper drying apparatus 405 Humidity sensor 406 Heat pump 412 Chamber 501 Drain 502,512 Drain flow path 505 Drain tank 507 Pump 510 Empty discharge receptacle 551 Cap air supply path 552 Flow Road opening valve

JP 2006-169710 A JP 2010-125828 A

Claims (9)

An ink jet recording apparatus that forms an image by ejecting ink onto a recording medium by a recording head,
A drying chamber provided on the downstream side of the recording head in the conveyance path of the recording medium, and drying the recording medium;
A paper drying apparatus that separates moisture in the circulating gas and has a heat pump that is a high-temperature dry gas, and circulates the gas in the drying chamber;
Drying prevention means for supplying water separated by the heat pump to the front side of the recording head and making the front side a humid atmosphere to prevent drying of the recording head;
An ink jet recording apparatus comprising: The ink jet recording apparatus according to claim 1,
The drying prevention means
An empty discharge receiver that is provided at a position facing the recording head across the recording medium at the time of printing, and receives empty ink for preventing ink clogging of the recording head;
Supply means for supplying water separated by the heat pump to the empty discharge receptacle;
An ink jet recording apparatus comprising: An ink jet recording apparatus according to claim 1 or 2,
The drying prevention means
A cap that covers the recording head during non-printing;
Supply means for supplying water separated by the heat pump to the cap part;
An ink jet recording apparatus comprising: An ink jet recording apparatus according to claim 1 or 2,
The drying prevention means
A cap that covers the recording head when not printing,
A branch pipe for guiding a gas containing moisture separated from the recording medium in the drying chamber to the cap part;
An ink jet recording apparatus comprising: An ink jet recording apparatus according to claim 4,
Detection means for detecting the humidity of the gas containing moisture;
Opening and closing means for opening and closing the branch pipe;
Control means for opening the branch pipe by the opening and closing means when the humidity detected by the detection means is greater than a preset humidity, and supplying the gas containing moisture to the cap portion;
An ink jet recording apparatus comprising: An ink jet recording apparatus according to any one of claims 1 to 5,
The ink-jet recording apparatus, wherein the separated water is taken out from a drain of the heat pump. A printing method for an ink jet recording apparatus that forms an image by ejecting ink onto a recording medium using a recording head,
Drying the recording medium in a drying chamber provided downstream of the recording head in the conveyance path of the recording medium;
The water transferred to the gas circulating by drying in the drying chamber is separated by a heat pump,
Supplying the water in which the separated water is condensed to the front side of the recording head;
A printing method for an ink jet recording apparatus, wherein the front side is made a humid atmosphere to prevent drying of the recording head. A printing method for an ink jet recording apparatus according to claim 7,
The front surface side in which the humidified atmosphere is provided is an empty discharge receiver that is provided at a position facing the recording head with the recording medium sandwiched during printing, and receives empty ink for preventing ink clogging of the recording head. A printing method for an ink jet recording apparatus, A printing method for an ink jet recording apparatus according to claim 7,
A printing method for an ink jet recording apparatus, wherein the front surface side in the humidified atmosphere is a cap portion that covers the recording head during non-printing.

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