JP2012096514A - Inkjet recorder and cooling method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To achieve high speed printing and low power consumption without degrading printing quality by cooling required places using the endothermic action of a heat pump.SOLUTION: An inkjet device 1 includes an inkjet head 110a for ejecting ink onto paper 10, and a head drive substrate 115, and forms an image on the paper 10 by use of the head 110a. The inkjet device 1 further includes the heat pump 406 that has a cool air circulation passage 431 and a hot air circulation passage 410, separates moisture in hot air Ah returned from the hot air circulation passage 410 and sends moisture-separated air to the cool air circulation passage 431 as cool air Ac, and heats cool air Ac returned from the cool air circulation passage 431 and sends the heated air to the hot air circulation passage 410 as hot air Ah. The head drive substrate 115 or an array plate 110 on which the head 110a is mounted, is disposed in the cool air circulation passage 431 and is cooled by the cool air dried and cooled by the heat pump 406.

Description

  The present invention relates to an ink jet recording apparatus and a cooling 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 an ink jet recording apparatus including an image forming apparatus such as a copier, a printer, a facsimile, a digital multifunction peripheral having these functions combined, and a printing machine, and a cooling method executed in the ink jet recording apparatus.

  An ink jet recording apparatus ejects ink droplets onto a sheet-like recording medium by an ink jet head, penetrates into the recording medium, or adheres to the surface to form an image or print. It has become. As described above, since ink droplets are used in the ink jet recording apparatus, the atmosphere of the printing part becomes a high humidity environment, and not only the printing part 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, 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.

  Patent Document 2 (Japanese Patent Application Laid-Open No. 2002-361850) includes a hot air generator that generates hot air, a drying main body that dries continuous paper, and a dehumidifier that dehumidifies the hot air, and the hot air generated from the hot air fan is dried by the main body. An invention is disclosed in which the continuous paper is dried by guiding the air to the drying body, the hot air guided to the drying body is guided to the dehumidifier and dehumidified, and then guided to the hot air machine again.

  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 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 ink jet recording devices. I can't do it. The heat pump type dryer is merely used as a drying means, and no consideration is given to other uses.

  In addition, in the invention described in Patent Document 2, it is only described that hot air is sent into a casing and continuous paper is passed through the casing to be dried. There is no particular consideration, and it is difficult to cope with an inkjet recording apparatus for high-speed printing.

  On the other hand, since these apparatuses relate to heating and drying, no special consideration is given to cooling. Therefore, when printing is performed, the temperature of the entire apparatus rises. On the other hand, in such an ink jet recording apparatus, a control circuit including a CPU and a driving circuit for each part including an ink jet head are usually mounted on a substrate, and the substrate is installed in the apparatus. For this reason, when the temperature rises, the temperature of the substrate also rises, and there is a possibility that a failure due to the temperature rise of the substrate may occur. Further, when the temperature of the ink jet head array rises, it is thermally deformed and the positional deviation of the printing position becomes large, which causes a decrease in printing quality.

  In order to avoid such a temperature rise, a cooling device having a large cooling capacity may be provided. However, if a separate cooling device is provided, the cost increases correspondingly, and a space for installing the cooling device is also required. In addition, the operation cost will be extra. On the other hand, in the heat pump as described in the cited reference 1, heat absorption and heat dissipation are performed by decompression and compression, moisture in the air is condensed and recovered as water droplets, and dry air is obtained. Even if a separate cooling device is not installed, cooling can be performed by components in the ink jet recording apparatus.

  Therefore, the problem to be solved by the present invention is that it is possible to cool a necessary portion by using the heat absorption effect of the heat pump, and therefore, it is possible to increase the printing speed in the ink jet recording apparatus without causing deterioration in printing quality. The purpose is to reduce the power consumption.

  In order to solve the above problems, the present invention uses air cooled by a heat pump when cooling a recording medium using a heat pump to cool a heat generating portion around the head of the ink jet recording apparatus. It is characterized in that cooling and air heated in the heat generating part are used as an additional heat amount when the recording medium is dried.

  Specifically, the first means includes a recording head that discharges ink onto a recording medium, and a head drive board that includes a control circuit that controls driving of the recording head, and the recording head performs the above-described operation. An ink jet recording apparatus for forming an image on a recording medium, wherein the recording medium is provided on a downstream side of the recording head in a conveyance path of the recording medium, and a drying chamber for drying the recording medium; a cold air circulation path; A hot air circulation path is provided, moisture in the hot air returned from the hot air circulation path is separated and sent as cold air to the cold air circulation path, and the cold air returned from the cold air circulation path is heated to warm the warm air as the warm air. And a paper drying device that circulates the hot air to the drying chamber connected to the hot air circulation path, and the recording head or the head drive substrate is circulated by the cold air. Is placed in the road, characterized in that it is cooled by the cold air.

  The second means is the first means, wherein the cold air circulation path takes in the outside air and blows air to the recording head or the head drive substrate side and the cold air passed through the cold air circulation path is Including a second path that exhausts to the outside before reaching the recording head or the head drive substrate side, and the cold air circulation path includes an outside air circulation path that uses the first path and the second path, and Switching means for switching between the first path and the inside air circulation path that does not use the second path is provided.

  A third means includes a detection means for detecting a temperature of the cold air in the cold air circulation path before reaching the recording head or the head driving substrate side in the second means, and is detected by the detection means. And switching control means for switching from the inside air circulation path to the outside air circulation path by switching by the switching means when the temperature is higher than a preset temperature condition.

  In the fourth means, in the third means, the temperature condition is set based on a difference between the temperature of the cold air in the cold air circulation path detected by the detection means and the temperature of the outside air outside the apparatus. It is characterized by that.

  The fifth means further comprises control means for increasing the air volume by the blower of the heat pump or lowering the blowing temperature by driving the decompressor in accordance with the switching by the switching control means in the third or fourth means. It is characterized by.

  A sixth means includes any one of the first to fifth means including a head array plate on which a plurality of the recording heads are mounted and a cooling chamber in which the head driving substrate is accommodated in the same space, It is arranged in the cold air circulation path.

  The seventh means is characterized in that, in the sixth means, the cold air passing through the cooling chamber is guided to the heating side of the heat pump.

  The eighth means has a recording head for ejecting ink onto the recording medium, and a head drive substrate on which a control circuit for controlling the driving of the recording head is mounted, and is applied onto the recording medium by the recording head. A cooling method for an ink jet recording apparatus for forming an image, comprising: a drying chamber provided on a downstream side of the recording head in a conveyance path of the recording medium; a drying chamber for drying the recording medium; a cold air circulation path; It has a circulation path, water in the hot air returning from the hot air circulation path is separated and sent as cold air to the cold air circulation path, and the cold air returning from the cold air circulation path is heated to circulate the hot air as hot air A paper drying device that circulates the hot air in the drying chamber connected to the hot air circulation path, and the temperature in the cold air circulation path is preliminarily based on the outside air temperature. Setting When the temperature is higher than the specified temperature condition, outside air is introduced into the cold air circulation path to cool the recording head or the head driving substrate, and the outside air used for cooling is returned to the heat pump and heated. Hot air is sent to the drying chamber to dry the recording medium.

  In the embodiments described later, the recording head is the inkjet head 110a, the recording medium is the paper 10, the head drive substrate is 115, the inkjet recording apparatus is the inkjet apparatus 1, and the drying chamber is the drying chamber 412. The cold air circulation path is indicated by reference numeral 431, the hot air circulation path is indicated by reference numeral 410, the heat pump is indicated by reference numeral 406, the paper drying apparatus is indicated by reference numeral 400, the cold air is indicated by reference numeral Ac, the hot air is indicated by reference numeral Ah, and the first path is external air. The connection path 431e ′ having the intake port 431e, the second path is the connection path 431f ′ having the exhaust port 431f, the switching means is the flow path changing plate 431g, the switching control means is the control unit 120, and the detection means Increases the air volume from the heat pump fan to the temperature sensor 431h, the fan to the numerals 420a and 420b, and the decompressor to the numeral 460. It is allowed, or the control means for reducing the air blowing temperature by driving the pressure reducer to the control unit 120, the head array plate in the array plate 110, the cooling chamber in the array chamber 109, the corresponding.

  According to the present invention, when the recording medium is dried using a heat pump, the air cooled by the heat pump is used for cooling the heat generating portion, and the air heated by the heat generating portion is cooled. Since it is used as an additional heat amount when the recording medium is dried, it is possible to cool the necessary part by using the heat absorption effect of the heat pump, and as a result, the printing in the ink jet type recording apparatus without causing the deterioration of the printing quality. The speed can be increased and the power consumption can be reduced.

It is a figure which shows the system configuration | structure of the whole inkjet recording device of Example 1 in embodiment of this invention. It is a schematic block diagram which expands and shows the ink jet type recording apparatus shown in FIG. It is a top view which shows the internal structure of the inkjet apparatus shown in FIG. It is a schematic block diagram which shows the function structure and ventilation path | route of the heat pump in Example 1. FIG. 6 is a plan view illustrating an internal structure of an ink jet apparatus according to Embodiment 2. FIG. It is a front view which shows the circulation path | route of the cold wind in the case of inside air circulation in Example 2. FIG. It is a front view which shows the circulation path in the case of external air circulation. It is a schematic block diagram which shows the function structure and ventilation path | route of a heat pump in the case of inside air circulation. It is a schematic block diagram which shows the function structure and ventilation path | route of a heat pump in the case of external air circulation. 6 is a block diagram showing a control configuration of an ink jet recording apparatus in Embodiment 2. FIG.

  The present invention guides the hot air circulation path of the heat pump to the drying object side and the cool air circulation path of the heat pump to the cooling object, cools the cooling object with cold air, and circulates the heat obtained from the cooling object It is applied to the path side and contributes to the temperature rise of the warm air in the warm air circulation path by the heat pump, thereby enabling high-speed and efficient drying. Hereinafter, embodiments of the present invention will be described 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) of Example 1 of the present embodiment. In FIG. 1, the system according to the present embodiment is basically composed of an ink jet device 1, a paper feeding device (unwinder) 2, and a winding device (rewinder) 3. Each of these devices 1, 2, and 3 is a sheet. The sheet feeding device 2, the inkjet device 1, and the winding device 3 are arranged on a straight line in the order along the transport direction. In the present 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. Further, in the present embodiment, the paper 10 is representatively exemplified as one of the sheet-like recording media, and the paper 10 is the paper, cloth, films, and the like used as the recording medium. It can be spread on a sheet-like member made of a synthetic resin material.

  The ink jet apparatus 1 includes an ink jet image forming unit 100 including an ink jet head 110a, and an ink jet image forming unit 10 that is on the upstream side (front stage) of the ink jet image forming unit 100 in the paper transport direction. And an outfeed unit 300 for sending the paper 10 printed by the inkjet image forming unit 100 to the take-up device 3 side.

  FIG. 2 is an enlarged front view showing the inkjet apparatus 1 of FIG. In the figure, 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 a head drive board 115 on which a control circuit including an ink jet head 110a and a CPU is mounted, and executes image forming and paper feed control for the paper 10 based on an instruction from a host device (not shown). As shown in the plan view of FIG. 3, the inkjet head 110a is composed of an inkjet head array in which a plurality of heads are arranged in a row in a direction perpendicular to the paper transport direction and arranged in a plurality of rows in a staggered pattern in the paper transport direction. The array is configured as an array plate 110 installed on a single plate, and is arranged at a position facing the paper transport path 111. The ink jet heads 110a on the array plate 110 are individually energized by the CPU on the head drive substrate 115 to discharge ink liquid, and form a print image on the paper 10 conveyed at high speed. The array plate 110 including the inkjet head 110a and the head driving substrate 115 are installed in the array chamber 109. The array plate 110 is disposed in the lower portion of the array chamber 109, and the head driving substrate 115 is disposed in the upper portion.

  A paper drying device 400 (see FIG. 3) further provided with a heat pump 406 is installed on the front side of the ink jet image forming unit 100. In the drawing of the heat pump 406, the hot air blowing outlet 401 passes through the outfeed unit 300, Hot air blowing paths 410a and 410b that return to the heat pump 406 through the suction port 402 are provided. The upstream hot air blowing path 410a includes an upstream first duct 411, a drying chamber (hereinafter referred to as "chamber") 412, a downstream second duct 413, and a downstream hot air blowing path 410b. A conveyance path for the paper 10 is formed in the drying chamber 412. A hot air circulation path 410 including a drying chamber 412 is configured by the upstream hot air blowing path 410a and the downstream hot air blowing path 410b.

  As described above, the drying 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 paper surface so that the paper 10 can be dried and dehumidified.

  On the other hand, in FIG. 2, the heat pump 406 passes from the lower cold air outlet 432 through the upstream cold air blowing path 431a, the cold air inlet 431c, the array chamber 109, the cold air outlet 431d, and the downstream cold air blowing path 431b, and through the suction port 433. A cold air circulation path 431 is provided to return to FIG. As will be described later in the cold air circulation path 431, the water is separated by being cooled by the heat exchanger 430 on the cooling side of the heat pump 406, and the dry cold air circulates. The hot air circulation path 410 has heat on the heating side of the heat pump 406. Hot dry air heated by the exchanger 440 circulates.

  In the outfeed unit 300, a plurality of guide rollers 310 including a guide roller 310 for passing through the drying chamber 412 are installed, and the outfeed provided in the outfeed unit 300 on the most downstream side in the paper conveyance direction. A feeding force is applied by the feed roller 320 and the nip roller 330, and the paper is fed from the paper discharge port 340 to the winding device 3 side through the last-stage guide roller 310, and is wound in a roll shape by the winding device 3. In the present 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 manner.

  FIG. 3 is a plan view showing the internal structure of the inkjet apparatus 1 of FIG. As can be seen from FIG. 3, a paper drying device 400 provided with a heat pump 406 is disposed on the front surface of the inkjet image forming unit 100, and as shown in FIG. 2, the paper drying device 400 is blown from the outlet 401 of the heat pump 406. High-temperature dry air is guided to the upstream hot air blowing path 410a, supplied to the drying chamber 412 in the outfoot unit 300, and returns from the drying chamber 412 to the heat pump 406 through the downstream hot air blowing path 410b. Further, the hot air blowing paths 410a and 410b are respectively provided in the first duct 411 and the second duct at substantially the center in the direction orthogonal to the sheet conveying direction on the most upstream side and the most downstream side of the drying chamber 412 in the sheet conveying direction. The hot air circulation path 410 that is joined by the duct 413 and returns from the heat pump 406 to the heat pump 406 is formed.

  A transport path for the paper 10 is formed along the inside of the lower wall surface of the drying chamber 412 in FIG. 3, and the paper 10 is guided outside the drying chamber 412 from the guide roller 310 a at the final stage in the drying chamber 412. The high-temperature dry air deprived of the moisture from the paper 10 is guided to the downstream hot air blowing path 410b downstream of the final stage guide roller 310a and returns to the heat pump 406. In FIG. 3, the first and second ducts 411 and 413 are singular on the discharge side and the suction side, respectively, but the flow velocity distribution in the drying 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 3 are examples in which warm air is sent in the same direction as the paper 10 (arrow D1 direction: forward direction) as indicated by an arrow D2. The warm air from the heat pump 406 may be sent in the reverse direction.

  FIG. 4 is a schematic configuration diagram showing a functional configuration of the heat pump and a ventilation path. The heat pump 406 is a heat pump using a heat medium, and includes blowers 420a and 420b, heat exchangers 430 and 440 on the cooling side and heating side, a compressor 450 and a decompressor 460, and these parts are blowout ports 401 and 432 and suction. It is housed in a case 407 in which the mouths 402 and 433 are formed. 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 warm air (high temperature dry air) Ah supplied to the drying chamber 412 circulates in the direction of the figure D2.

  The blowers 420a and 420b, which are the driving sources for the hot air supplied to the drying chamber 412 and the driving sources for the cold air supplied to the array plate 110 and the head driving substrate 115 of the array chamber 109, Cold air is blown out through the vicinity of the heat exchanger 430 on the cooling side through the vicinity of the heat exchanger 430 on the cooling side, which is disposed near the upstream side of the air outlet 432 and near the downstream side of the cold air inlet port 433, respectively. The air is fed into the mouth 432 and blown from the upstream cool air blowing path 431a to the array chamber 109 side. Then, the array plate 111 and the head drive substrate 115 are cooled while passing through the array chamber 109 (in the direction of arrow D4), and the heated cold air passes through the cold air blowing path 431b on the downstream side from the suction port 433 to the heating side heat exchanger. The hot air Ah is sent to the hot air circulation path 410 from the outlet 401 as hot air Ah heated to a predetermined temperature by the heat exchanger 440 on the heating side.

  In parallel with this, the heat medium of the heat pump 406 is decompressed by the decompressor 460, becomes lower than the ambient temperature, and is sent to the cooling-side heat exchanger 430. Then, the heat exchanger 430 on the cooling side is cooled, and the humid air (warm air) sucked from the suction port 402 is separated into water droplets 409 and dry air.

  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 that has reached a high temperature is sent to the heat exchanger 440 on the heating side, exchanges heat with the air sucked from the suction port 433, and sent to the decompressor 460. On the other hand, the air that has passed through the heat exchange 440 on the heating side as described above is sent out from the outlet 401 as warm air Ah.

  That is, the heat pump 406 exchanges heat with the air circulating in the hot air circulation path 410 and the cold air circulation path 431 in the process of heat absorption and heat dissipation by repeatedly expanding and compressing the heat medium, deprives the paper 10 of moisture, and sucks the inlet. The dehumidified air introduced from 402 to the heat pump 406 side is dehumidified, and an amount of heat sufficient to dry the paper 10 is supplied to the cold air Ac returned through the cold air circulation path 431. It sends out as 100 degreeC warm air Ah.

  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 way, the paper 10 is dried in the drying chamber 412 connected to the hot air circulation path 410 while the hot air Ah is circulated to the hot air circulation path 410 by the blowers 420a and 420b of the heat pump 406, and then the moisture is contained. A circulation path in which air is collected, the collected moisture-containing air is sent to the cold air circulation path 431 as cold air dried by the heat pump 406, heat is exchanged in the array chamber 109, returned to the heat pump 406, and sent again as hot air Ah. The paper 10 can be dried in the inkjet apparatus 1 that performs 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 FIG. 2, the paper 10 is conveyed along the lower surface in the drying chamber 412, and the hot air Ah moves on the printing surface side of the paper 10 at a predetermined relative speed, so that the moisture contained in the paper 10 Is transferred into dry hot air Ah. In this case, the blowing speed from the blower 420 is preferably a speed at which a relative speed is maintained such that the transfer of moisture from the paper 10 into the warm air Ah maintains an equilibrium state.

  In the first embodiment, the hot air circulation path 410 and the cold air circulation path 431 are provided on one side and the other side of the heat pump 406, the printed paper 10 is dried by the hot air circulation path 410, and the cold air circulation path 431 is used as an array. The array plate 111 and the head drive substrate 115 in the chamber 109 are cooled. However, the heat pump 406 has poor rise characteristics, and it takes 20 to 30 minutes to reach steady operation. For this reason, when the temperature of the cold air is high, the cool air is not blown into the array chamber 109 and a cooling effect cannot be obtained. In the present embodiment, in order to deal with such a situation, when the temperature of the cold air is higher than the room temperature of the place where the inkjet apparatus 1 is installed, outside air is taken in at the initial stage of operation and used as the cooling air.

  FIGS. 5 to 9 are diagrams for explaining the ink jet apparatus 1 according to the second embodiment. FIG. 5 is a plan view corresponding to FIG. 3, and FIG. 6 is a front view showing a circulation path of cold air in the case of inside air circulation. 7 is a front view showing a circulation path in the case of outside air circulation, FIG. 8 is a schematic configuration diagram showing a functional configuration and a ventilation path of the heat pump corresponding to FIG. 4 in the case of inside air circulation, and FIG. 9 is a case in the case of outside air circulation. It is a schematic block diagram which shows the function structure and ventilation path | route of a heat pump.

  As shown in FIGS. 5 and 6, the second embodiment is different from the inkjet apparatus 1 of the first embodiment in that the connecting pipe line 431e ′ having an outside air intake port 431e and an exhaust port 431f in the upstream cool air blowing path 431a, 431f ′ is connected, and a flow path change plate 431g and a temperature sensor 431h for switching between the internal air circulation and the external air circulation are provided at the branch portion of the cold air circulation path 431. The temperature sensor 431h is the flow path change plate 431g. It is arranged in the immediate vicinity of the upstream side. The other parts are configured in the same manner as in the first embodiment and function in the same manner, and thus redundant description is omitted.

  As shown in FIG. 5, the outside air intake port 431e and the exhaust port 431f open to the upper part of the inkjet image forming unit 100 and the infeed unit 200, and are connected to the upper part of the upstream cool air blowing path 431a by the connecting pipe lines 431e 'and 431f'. A flow path changing plate 431g is connected to the corner portion and is connected to the connecting pipe lines 431e 'and 431f' so as to be rotatable about 90 degrees. When only the inside air is circulated without taking in the outside air, the flow path changing plate 431g is rotated to the position shown in FIG. 6 to close the outside air side, and when the outside air is taken in, the upstream side as shown in FIG. The cold air blowing path 431a on the side and the connection pipe line 431f ′ of the exhaust port 431f are connected, and the connection pipe line 431e ′ of the outside air intake port 431e and the duct of the inlet of the array chamber 109 are connected.

  As a result, when the inside of the array chamber 109 is cooled by the inside air circulation, as shown in FIG. 8, the cold air from the heat pump 406 is guided into the array chamber 109 through the upstream cold air blowing path 431a, and downstream. It returns to the heat pump 406 side through the cold air blowing path 431b on the side. In contrast, when the inside of the array chamber 109 is cooled by outside air circulation, as shown in FIG. 9, the cold air from the heat pump 406 is discharged out of the apparatus from the exhaust port 431f through the upstream cold air blowing path 431a. Then, outside air is introduced into the array chamber 109 from the outside air intake port 431e, and the array chamber 109 is cooled, and then returned to the heat pump 406. Whether the inside air circulation or the outside air circulation is used is meaningless when the inside air temperature is lower than the outside air temperature, and is set according to the relationship between the inside air temperature and the outside air temperature. Therefore, the temperature sensor 431h is disposed at the position. The outside air temperature is detected by a temperature sensor outside the apparatus (not shown).

  FIG. 10 is a block diagram illustrating a control configuration of the ink jet apparatus including the heat pump according to the second embodiment. In FIG. 1, the inkjet apparatus 1 includes a control unit 120 that is communicably connected to a host apparatus 130. The control unit 120 drives an operation panel 140, a data storage unit 123, a decompressor 460, and a compressor 450. A motor driver 124 for controlling, a motor driver 125 for driving and controlling the blower 420, and a motor driver 431g ′ for driving and controlling the flow path changing plate 431g are connected. The control unit 120 receives a detection output from a temperature sensor 431h that detects humidity in the cool air blowing path 431a in the vicinity of the flow path changing plate 431g. Thereby, the control unit 120 of the inkjet apparatus 1 refers to the control data stored in the data storage unit 123 and controls the switching of the flow path by the flow path control plate 431g via the motor driver 431g '. 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.

  In this embodiment, the flow path changing plate 431g is driven by a motor, and the operation of the flow path changing plate 431g is controlled by a motor driver 431g ′. Needless to say, the driver is selected accordingly if it is different such as solenoid drive.

  The control unit 120 includes a CPU, a ROM, and a RAM. The CPU reads a program code stored in the ROM, develops the read program code in the RAM, and uses the RAM as a work area and a data buffer. The control defined by the program code is executed. At that time, the control unit 120 detects not only the output from the temperature sensor 431h but also the detection output from the sensors installed in each part of the inkjet apparatus 1 and the print data (print density) from the host apparatus 130. The decompressor 460, the compressor 450, and the blower 420 are controlled via the motor drivers 124 and 125 in accordance with the information), and the blower temperature and blower speed are controlled.

  In the present embodiment, the switching control between the inside air circulation and the outside air circulation and the drive control of the heat pump 406 are performed using the detection output (detected temperature) of the temperature sensor 431h and the outside air temperature as parameters. For example, when the temperature of the cold air in the upstream circulation path 431a detected by the temperature sensor 431h is equal to or higher than the outside air temperature and is equal to or higher than a predetermined temperature, the control unit 120 moves the flow path changing plate 431g. Switching to the outside air circulation side, the inside of the array chamber 109 is cooled by the outside air circulation shown in FIGS. At that time, it is also possible to simultaneously control the blowers 420a and 420b to increase the air volume, and further to control the decompressor 460 to decrease the cold air temperature.

  Since the outside air temperature varies widely depending on the installed local conditions, seasonal conditions, etc., the control conditions of the blowers 420a and 420b and the control conditions of the pressure reducer 460 with respect to these temperature conditions are experimentally obtained, and a data table is obtained in advance. Is stored in the data storage unit 123, and the control unit 120 controls each unit with reference to the data table. When the temperature of the cool air that allows steady operation is reached, naturally, the control is switched to the inside air circulation and the predetermined control for drying the paper is executed.

  In the first and second embodiments, the array plate 110 and the head driving substrate 115 are installed in the array chamber 109, and the cool air is introduced into the array chamber 109 from the cool air circulation path 431. Depending on where the array plate 110 and the head drive substrate 115 are installed, only one of them may be cooled. In such a case, which is arranged on the cooling side is a design selection condition.

As described above, according to the present embodiment, the following effects can be obtained.
(1) Since the heat pump 406 is used to dry the paper 10, it is possible to achieve both reliable drying with warm air (high temperature dry air) Ah and low power consumption. As for the reduction in power consumption, it is possible to expect a reduction in power consumption of up to about three times compared to the case where a heating device such as a heater is used.

(2) Since hot air (high-temperature dry air) Ah is created by the heat pump 406 and circulated into the drying chamber 412, water taken from the paper 10 in the drying chamber 412 can be surely formed into water droplets on the heat pump 406 side. it can. As a result, the equipment and equipment environment does not become highly humid, or it is possible to eliminate the need for exhaust equipment from the equipment installation room to the outside, leading to purification of the equipment environment and reduction of equipment costs.

(3) As a start-up characteristic of the heat pump 406, it takes 20 minutes or more until stable hot air can be blown, but the outside air is taken in until the cool air circulation path 431 is lowered to a predetermined temperature as compared with the outside air temperature. The plate 110 and the head driving substrate 115 can be cooled. Thereby, it can prevent that the cold wind of the temperature which cannot exhibit cooling capability circulates, and inhibits cooling.

(4) Since the amount of heat generated from the inkjet head section of the array plate 110 and the head drive substrate 115 can be converted into the amount of drying heat of the paper 10 by the heat pump 406, power consumption can be reduced accordingly.

(5) Since the array plate 110 can be efficiently cooled, the occurrence of misalignment in printing can be suppressed and good print quality can be guaranteed.

(6) Since the head drive substrate 115 can be efficiently cooled, it is possible to eliminate the failure of the head drive substrate 115 due to heat generation.

(7) Since cool air is introduced into the array chamber 109 containing the array plate 110 and the head drive substrate 115 and cooled, and led to the heat pump 406 side, the cool air containing unnecessary heat is efficiently wasted on the heat pump 406 side. It can be taken in without any problem, and energy efficiency can be improved accordingly.

  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 examples is shown as one of the preferred embodiments. However, those skilled in the art will recognize various alternatives, modifications, variations, and improvements from the contents disclosed in this specification. Which can be realized and fall within the scope defined by the appended claims.

DESCRIPTION OF SYMBOLS 1 Jet type recording apparatus 10 Paper 109 Array chamber 110 Array plate 110a Inkjet head 111 Conveyance path 115 Head drive board 120 Control part 400 Paper drying apparatus 406 Heat pump 410 Hot air circulation path 412 Drying chamber (drying chamber)
420a, 420b Air blower 431 Cold air circulation path 431e Outside air intake port 431e 'Connection pipe line 431f Exhaust opening 431f' Connection pipe line 431g Flow path change plate 431h Temperature sensor 460 Pressure reducer Ac Cold air Ah Hot air

JP 2006-169710 A JP 2002-361850 A

Claims (8)

An ink jet type that has a recording head for ejecting ink onto a recording medium and a head driving substrate on which a control circuit for controlling the driving of the recording head is mounted, and forms an image on the recording medium by the recording head A recording device,
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;
It has a cold air circulation path and a hot air circulation path, separates moisture in the hot air returned from the hot air circulation path, sends it as cold air to the cold air circulation path, and heats the cold air returned from the cold air circulation path to warm it. A paper drying device that has a heat pump that sends the hot air to the hot air circulation path, and circulates the hot air in the drying chamber connected to the hot air circulation path;
With
An ink jet recording apparatus, wherein the recording head or the head driving substrate is disposed in the cold air circulation path and is cooled by the cold air. The ink jet recording apparatus according to claim 1,
The cold air circulation path takes in the outside air and blows air to the recording head or the head drive substrate side and before the cold air passed through the cold air circulation path reaches the recording head or the head drive substrate side. Including a second path for exhausting to the outside air,
The cold air circulation path is provided with switching means for switching between an outside air circulation path using the first path and the second path and an inside air circulation path not using the first path and the second path. An ink jet recording apparatus. An ink jet recording apparatus according to claim 2,
Detecting means for detecting a temperature of the cold air in the cold air circulation path before reaching the recording head or the head drive substrate side;
When the temperature detected by the detection means is higher than a preset temperature condition, switching by the switching means, switching control means for switching from the inside air circulation path to the outside air circulation path,
An ink jet recording apparatus comprising: An ink jet recording apparatus according to claim 3,
An ink jet recording apparatus, wherein the temperature condition is set based on a difference between a temperature of the cold air in the cold air circulation path detected by the detecting means and a temperature of outside air outside the apparatus. An ink jet recording apparatus according to claim 3 or 4,
An ink jet recording apparatus further comprising control means for increasing the air volume by the blower of the heat pump or lowering the blower temperature by driving a decompressor in accordance with the switching by the switching control means. An ink jet recording apparatus according to any one of claims 1 to 5,
A head array plate on which a plurality of the recording heads are mounted and a cooling chamber in which the head driving substrate is accommodated in the same space;
An ink jet recording apparatus, wherein the cooling chamber is arranged in the cold air circulation path. An ink jet recording apparatus according to claim 6,
An ink jet recording apparatus, wherein cold air passing through the cooling chamber is guided to a heating side of the heat pump. An ink jet type that has a recording head for ejecting ink onto a recording medium and a head driving substrate on which a control circuit for controlling the driving of the recording head is mounted, and forms an image on the recording medium by the recording head A cooling control method for a recording apparatus,
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;
It has a cold air circulation path and a hot air circulation path, separates moisture in the hot air returned from the hot air circulation path, sends it as cold air to the cold air circulation path, and heats the cold air returned from the cold air circulation path to warm it. A paper drying device that has a heat pump that sends the hot air to the hot air circulation path, and circulates the hot air in the drying chamber connected to the hot air circulation path;
With
When the temperature in the cold air circulation path is higher than a preset temperature condition based on the outside air temperature, the outside air is introduced into the cold air circulation path to cool the recording head or the head drive substrate,
Heat the outside air used for cooling back into the heat pump,
A method for cooling an ink jet recording apparatus, wherein heated hot air is sent to the drying chamber to dry the recording medium.

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