JP5556445B2 - Drying device and liquid jet device - Google Patents

Description

  The present invention relates to a drying apparatus and a liquid ejecting apparatus.

  In general, ink jet printers are widely known as liquid ejecting apparatuses that eject liquid from a liquid ejecting head onto a recording medium. Some of such printers include a drying device that blows hot air on the ink of the recording medium adhered by the recording process during the conveyance of the recording medium (for example, Patent Document 1). .

  This drying device includes a suction fan for taking in air from the outside, a heater for warming up the taken-in air, a blowout port for blowing out the warmed air (warm air) toward the recording medium in the middle of conveyance, And a circulation space that guides the warm air blown from the air outlet to the intake fan again. Then, the ink adhering to the recording medium is dried by circulating hot air and spraying it on the recording medium.

JP 2009-45861 A

  By the way, in the drying device of Patent Document 1, the temperature in the air flow path is a predetermined allowable temperature at a position on the upstream side of the heater in the air flow path in which the air taken in from the suction fan flows to the outlet. There is provided an excessive temperature rise suppression means for urgently stopping the heater when the above is reached. For this reason, this excessive temperature rise suppression means disturbs the air flow in the air flow path and makes the air temperature and flow velocity non-uniform, and there is a possibility that the ink adhering to the recording medium cannot be dried uniformly.

  The present invention has been made in view of the above-described problems, and its purpose is to suppress unevenness in the drying state of the liquid adhering to the recording medium even when hot air with excessive temperature rise suppressed. Another object of the present invention is to provide a drying apparatus and a liquid ejecting apparatus.

In order to achieve the above object, a drying apparatus of the present invention is a drying apparatus that dries the liquid attached to the recording medium by blowing heated air onto the recording medium to which the liquid is attached, A heating means for heating, a temperature sensor for detecting the temperature in the air flow path portion through which the air heated by the heating means flows, and the heating state of the heating means based on the detection result of the temperature of the air by the temperature sensor A controller for controlling the temperature of the air flow path section through which the air heated by the heating means flows , and the heating means when the temperature in the air flow path section is equal to or higher than a preset allowable temperature. And an excessive temperature rise suppression means for cutting off the supply of electric power to the battery, and the excess temperature rise suppression means is disposed outside the air flow path portion.

  According to this configuration, the air flow is not disturbed by the excessive temperature rise suppression means when the air heated by the heating means flows in the air flow path portion. That is, the excessive temperature rise suppression means can detect the excessive temperature rise state of the drying apparatus without disturbing the air flow in the air flow path portion. Therefore, even when hot air is blown from a drying apparatus in which excessive temperature rise is suppressed, it is possible to suppress the drying state of the liquid adhering to the recording medium from becoming uneven.

In the drying apparatus of the present invention, the excessive temperature rise suppression means is attached to a heat conductive member having thermal conductivity and detects the temperature in the air flow path portion through the heat conductive member.
According to this configuration, even if the air temperature in the air flow path portion is uneven, the excessive temperature rise suppression means can detect the air temperature averaged by the heat conducting member. Further, even if the temperature abnormality occurs at a distance from the excessive temperature rise suppression means, the heat conduction member conducts heat so that the excessive temperature increase suppression means can detect the abnormality. Therefore, the reliability of temperature detection in the excessive temperature rise suppression means can be improved.

In the drying apparatus of the present invention, the heat conducting member is a flow path forming member that forms the air flow path portion.
According to this configuration, the excessive temperature rise suppression means is attached to the flow path forming member as the heat conducting member that comes into direct contact with the air flowing in the air flow path section, so that the air temperature in the air flow path section is reduced. It can be detected reliably. Therefore, the reliability of the excessive temperature rise suppression means can be further improved.

In the drying apparatus of the present invention, the excessive temperature rise suppression means is disposed close to the upper part in the vertical direction of the heating means.
According to this configuration, even when air is not taken in from the outside of the drying device and the air does not flow in the air flow path portion, the hot air heated by the heating means flows upward, so the excessive temperature rise suppression means Can detect anomalies quickly. Therefore, the reliability of the excessive temperature rise suppression means can be further improved.

  In order to achieve the above object, the liquid ejecting apparatus of the present invention performs recording by ejecting liquid in the middle of the transport path to the recording medium transported from the upstream side to the downstream side of the transport path. A liquid ejecting head, and a drying device having the above-described configuration provided at a position downstream of the liquid ejecting head in the transport path.

  According to this configuration, it is possible to obtain the same operational effects as in the case of the drying device in the liquid ejecting apparatus.

FIG. 2 is a schematic side view of the printer according to the present embodiment. The schematic sectional drawing of a heater unit.

  Hereinafter, an embodiment in which the present invention is embodied in an ink jet printer which is a kind of liquid ejecting apparatus will be described with reference to FIGS. 1 and 2. In the following description, when referring to “front-rear direction”, “up-down direction” and “left-right direction”, unless otherwise specified, “front-rear direction”, “up-down direction” and “left-right direction” indicated by arrows in each figure Direction ".

  As shown in FIG. 1, an ink jet printer (hereinafter also referred to as “printer”) 11 as a liquid ejecting apparatus according to the present embodiment includes a feeding unit 12 that feeds a continuous sheet S as a long recording medium. A recording unit 13 that performs recording by ejecting ink onto the fed continuous paper S and a winding unit 14 that winds the continuous paper S on which recording has been performed by the recording unit 13 are provided.

  That is, in the transport path of the continuous paper S, the feeding unit 12 is disposed at a position near the rear side that is upstream, and the winding unit 14 is disposed at a position near the front side that is downstream. . The recording unit 13 is disposed at a position between the feeding unit 12 and the winding unit 14. Further, a support plate 15 capable of supporting the continuous paper S is provided at a position near the rear side, which is the upstream side in the recording unit 13.

  As shown in FIG. 1, a winding shaft 16 extending in the width direction (left-right direction) orthogonal to the conveyance direction of the continuous paper S is rotatably provided in the feeding unit 12. The winding shaft 16 is supported so that the continuous paper S can be integrally rotated with the winding shaft 16 in a state where the continuous paper S is previously wound in a roll shape. That is, the continuous paper S is fed out of the winding shaft 16 by the rotation of the winding shaft 16 and is conveyed downstream in the conveying direction. Further, the first relay roller 17 for winding the continuous paper S fed from the winding shaft 16 and guiding it to the recording unit 13 is rotated in a state where the first relay roller 17 extends in the left-right direction at an obliquely forward position in the feeding unit 12. It is provided as possible. Then, the continuous paper S fed from the winding shaft 16 is wound around the first relay roller 17 from the lower rear side, so that the continuous paper S is horizontally directed toward the front side (downstream side) which is the recording unit 13 side. It is designed to be conveyed.

  In the recording unit 13, a recording head 18 as a line head type liquid jet head is disposed at a position facing the support plate 15. The lower surface of the recording head 18 is a horizontal nozzle forming surface in which a plurality of nozzles (not shown) for ejecting ink are opened. The recording head 18 extends in the width direction perpendicular to the transport direction of the continuous paper S in the horizontal direction, and the length in the longitudinal direction corresponds to the maximum paper width of the continuous paper S. The recording head 18 performs recording by ejecting ink onto the recording area of the continuous paper S conveyed to the front side (downstream side) while being in sliding contact with the upper surface of the support plate 15.

  Two pairs of transport rollers 19a and 19b each composed of a driving roller and a driven roller extending in the left-right direction are arranged at an interval at a position downstream (front side) of the transport path from the recording head 18 in the recording unit 13. ing. The transport roller pair 19a, 19b transports the continuous paper S downstream in the transport direction by the driven roller driven by the drive rotation of the drive roller while the continuous paper S is sandwiched between the drive roller and the driven roller. To do.

  Further, on the continuous paper S to which the ink ejected from the recording head 18 is attached at a position downstream of the recording path 18 (front side) in the recording unit 13 and between the conveying roller pair 19a, 19b. A heater unit 20 is provided as a drying device that performs a drying process. A controller 21 is electrically connected to the heater unit 20, and the temperature of the heater unit 20 is controlled by the controller 21.

  The take-up unit 14 is positioned so as to face the upstream (rear) first relay roller 17 in the horizontal direction at a position downstream (front) from the heater unit 20 in the transport path of the continuous paper S. Two relay rollers 22 are rotatably provided. Then, the continuous paper S transported in the horizontal front direction from the upstream first relay roller 17 to the second relay roller 22 is wound from the upper front side, whereby the continuous paper S is transported in the transport direction. Is switched from the horizontal rear direction to the front diagonally downward direction.

  In addition, a winding shaft 23 is rotatably provided at a position obliquely below the second relay roller 22 in the winding unit 14, and downstream of the continuous paper S in the conveyance direction with respect to the winding shaft 23. The tip that becomes the end is wound. The continuous paper S that has been subjected to the recording process and the drying process is sequentially wound by the winding shaft 23.

Next, the heater unit 20 will be described in detail with reference to FIG.
The heater unit 20 extends in the width direction perpendicular to the conveyance direction of the continuous paper S in the horizontal direction, and the length in the longitudinal direction corresponds to the maximum paper width of the continuous paper S. As shown in FIG. 2, the heater unit 20 has a cover 31 having a substantially rectangular parallelepiped shape formed of a resin such as modified polyphenylene ether. A plurality of (five shown in FIG. 2) intake ports 32 are regularly formed at predetermined intervals in the vertical direction on the front surface portion 31a which is the front side (downstream side) of the cover 31. Further, a substantially rectangular air outlet 33 extending in the longitudinal direction of the cover 31 is formed at a position on the rear side (upstream side) of the lower surface portion 31 b which is the lower side in the vertical direction of the cover 31.

  In addition, a plurality of fans 34 for taking in air outside the cover 31 through the intake port 32 are provided in the cover 31 at a position facing the intake port 32. Further, an air flow path portion 35 for guiding the air taken from the air inlet 32 to the air outlet 33 is provided inside the cover 31. That is, inside the cover 31, inner walls 35a and 35b having a substantially J-shaped cross section formed of a heat conductive member (for example, an iron plate) having heat conductivity are provided. The front end portions (one end portion) of the inner walls 35a and 35b are connected to the upper surface and the lower surface of the fan 34, respectively, while the rear end portions (the other end portion) are the rear edge portion and the front edge portion of the air outlet 33, respectively. Connected to the department. An air flow path portion 35 in which air flows in the cover 31 is defined by both side surfaces (not shown) of the cover 31 and the inner walls 35a and 35b. In this respect, the inner walls 35 a and 35 b function as a flow path forming member that forms the air flow path portion 35.

  A heater 36 as a heating unit is provided at a position downstream of the fan 34 in the air blowing direction and above the rear side (upstream side) of the air outlet 33 inside the air flow path 35. The heater 36 includes a heating element (not shown) that generates heat when electric power is supplied. In addition, the control unit 21 is electrically connected to the heater 36 via a heater driver (not shown) that switches between a power supply state (heat generation state) and a non-supply state (no heat generation state) to the heater 36. Has been. Then, the heater unit 20 rotates the fan 34 in a state where the heater 36 generates heat, thereby heating the air taken in from the air inlet 32 by the heater 36, and then using the heated air (warm air) to the continuous paper S. It comes to spray against.

  Further, in the air flow path portion 35, a position downstream of the heater 36 in the air blowing direction and upstream of the air outlet 33 in the air blowing direction is to detect the temperature of the air (hot air) heated by the heater 36. A temperature sensor 37 composed of a thermocouple is provided. The temperature sensor 37 is electrically connected to the control unit 21 and outputs a detection result to the control unit 21. When the detection signal from the temperature sensor 37 is input, the control unit 21 determines whether the temperature of the heated air (warm air) is a temperature suitable for executing the drying process of the continuous paper S. In addition, the heat generation state of the heater 36 is controlled based on the determination result.

  Further, inside the cover 31, there are an upper surface portion 31 c which is the upper side in the vertical direction of the cover 31, a rear surface portion 31 d which is the rear side (upstream side) of the cover 31, left and right side surface portions (not shown) of the cover 31, and an air flow path. An upper space portion 38 defined by the inner wall 35 a of the portion 35 is formed at a position above the air flow path portion 35 in the vertical direction. In the upper space 38, heater wiring (not shown) for supplying power from the main body side of the printer 11 to the heater 36 is disposed. In the middle of the heater wiring (not shown), the temperature is detected, and when the detected temperature is equal to or higher than a predetermined allowable temperature, an excessive rise that forcibly cuts off the supply of power to the heater 36 is performed. An excessive temperature rise suppression sensor 39 (for example, a thermostat made of bimetal or the like) is provided as a temperature suppression means. The excessive temperature rise suppression sensor 39 is disposed at a position on the rear side (upstream side) of the upper surface which is the upper side in the vertical direction of the inner wall 35a in the upper space portion 38, and a temperature detection unit 39a for detecting temperature is provided on the inner wall. It is in contact with the upper surface of 35a. That is, the excessive temperature rise suppression sensor 39 is disposed outside the air flow path portion 35 and close to the upper side of the heater 36 in the vertical direction. The excessive temperature rise suppression sensor 39 detects the temperature in the air flow path portion 35 via the inner wall 35a, and when the temperature in the air flow path portion 35 becomes equal to or higher than a predetermined allowable temperature, the heater 36 is used. By forcibly cutting off the power supply to the air flow, excessive temperature rise in the air flow path portion 35 is suppressed.

Next, the operation of the printer 11 configured as described above will be described, particularly focusing on the operation of the excessive temperature rise suppression sensor 39.
For example, when the recording process is started in the printer 11, the fan 36 is driven while the heater 36 of the heater unit 20 generates heat, and hot air begins to be blown out, and the continuous paper S is fed out from the feeding unit 12 and conveyed. It is conveyed from the upstream side of the direction to the downstream side. Subsequently, when the continuous paper S passes under the recording head 18, ink is ejected from the recording head 18 to the continuous paper S, whereby recording is performed on the surface of the continuous paper S. Then, when the continuous paper S to which the ink is attached is further transported and passes below the heater unit 20, hot air is blown from the outlet 33 of the heater unit 20 to the surface on which the continuous paper S is recorded. It is done.

  Here, since the excessive temperature rise suppression sensor 39 provided in the heater unit 20 is disposed outside the air flow path portion 35, the air taken into the air flow path portion 35 by the fan 34 has a flow. It reaches the heater 36 without being disturbed. The air that has reached the heater 36 is heated by the heater 36, and the heated air (warm air) is blown from the outlet 33 toward the continuous paper S with a uniform temperature and flow velocity.

Then, the continuous paper S whose surface ink has been dried by the heater unit 20 is conveyed to the winding unit 14 and is taken up by the take-up shaft 23.
In the middle of the recording process, if the heating of the heater 36 does not stop due to an abnormality in the temperature sensor 37, the control unit 21, etc., the heating temperature of the heater 36 rises and the air flow path 35 (especially the heater 36 The temperature in the vicinity of 36 and on the downstream side in the air blowing direction from the heater 36 increases. Since the inner walls 35a and 35b of the air flow path portion 35 have thermal conductivity, the excessive temperature rise suppression sensor is immediately disposed upstream of the heater 36 in the air blowing direction via the inner wall 35a. It is transmitted to the 39 temperature detection part 39a. And when the temperature in the air flow path part 35 becomes more than an allowable temperature, the supply of electric power to the heater 36 is forcibly cut off by the excessive temperature rise suppression sensor 39, whereby the heating of the heater 36 is stopped.

  Furthermore, when air stops flowing into the air flow path portion 35 due to an abnormality in the fan 34, the air heated by the heater 36 flows upward in the vertical direction of the heater 36. The temperature above 36 increases. Since the excessive temperature rise suppression sensor 39 is disposed close to the upper portion of the heater 36 in the vertical direction, the increased temperature is immediately transmitted to the temperature detection unit 39a of the excessive temperature increase suppression sensor 39 through the inner wall 35a. And when the temperature in the air flow path part 35 becomes more than an allowable temperature, the supply of electric power to the heater 36 is forcibly cut off by the excessive temperature rise suppression sensor 39, whereby the heating of the heater 36 is stopped.

According to the above embodiment, the following effects can be obtained.
(1) Since the excessive temperature rise suppression sensor 39 is arranged outside the air flow path portion 35 in the heater unit 20, when the air heated by the heater 36 flows in the air flow path portion 35, the excessive temperature rise suppression sensor 39 is used. Does not disturb the air flow. That is, the excessive temperature rise suppression sensor 39 can detect the excessive temperature rise state of the heater unit 20 without disturbing the air flow in the air flow path portion 35. Then, warm air having a uniform temperature and flow velocity is blown out from the heater unit 20. Therefore, even when warm air is blown from the heater unit 20 in which excessive temperature rise is suppressed, it is possible to suppress the drying state of the ink attached to the continuous paper S from becoming uneven. In addition, since the heater wiring (not shown) to which the excessive temperature rise suppression sensor 39 is connected is also arranged in the upper space portion 38 outside the air flow path portion 35, a wiring having no heat resistance is used as the heater wiring. Can be used.

  (2) The excessive temperature rise suppression sensor 39 is disposed in contact with the inner wall 35a forming the air flow path portion 35, and controls the temperature in the air flow path portion 35 through the inner wall 35a having thermal conductivity. Detect. Therefore, the temperature in the air flow path part 35 can be detected reliably. Moreover, even if the air temperature in the air flow path part 35 is not uniform, the excessive temperature rise suppression sensor 39 can detect the air temperature averaged by the inner wall 35a. Furthermore, even if a temperature abnormality occurs at a distance from the excessive temperature rise suppression sensor 39, heat is conducted through the inner wall 35a, so that the excessive temperature increase suppression sensor 39 can detect the abnormality. Therefore, the reliability of temperature detection in the excessive temperature rise suppression sensor 39 can be improved.

  (3) Since the excessive temperature rise suppression sensor 39 is disposed close to the upper part of the heater 36 in the vertical direction, the excessive temperature rise suppression sensor 39 can quickly detect the temperature abnormality of the heater 36. Further, even when air is not taken in from the outside of the heater unit 20 and air does not flow through the air flow path portion 35, the hot air heated by the heater 36 flows upward, so that the excessive temperature rise suppression sensor 39 Can detect anomalies quickly. Therefore, the reliability of the excessive temperature rise suppression sensor 39 can be further improved.

In addition, you may change the said embodiment as follows.
The recording medium is not limited to the continuous paper S, and may be a continuous film, for example. Further, the continuous paper S may be cut into a predetermined length during the conveyance. Further, the recording medium is not limited to a long one but may be a cut sheet formed in a predetermined size.

The recording head 18 is not limited to the line head type, and a short recording head may be moved in a direction intersecting the conveyance direction of the continuous paper S to perform recording on the full width of the continuous paper S.
The overheat suppression sensor 39 is not limited to a thermostat, and may be a temperature fuse, for example.

The excessive temperature rise suppression sensor 39 is not limited to be provided close to the upper side in the vertical direction of the heater 36, and may be provided at a position separated from the heater 36.
The overheat suppression sensor 39 is not limited to being attached to the inner wall 35a forming the air flow path portion 35, and may be attached to a heat conducting member different from the inner wall 35a. Moreover, it does not need to be attached to the heat conducting member. In that case, it is desirable that an opening be provided in the inner wall 35a or 35b forming the air flow path portion 35, and the excessive temperature rise suppression sensor 39 can detect the temperature in the air flow path portion 35 through the opening.

  In the above embodiment, the liquid ejecting apparatus is embodied in the ink jet printer 11, but a liquid ejecting apparatus that ejects or discharges liquid other than ink may be employed. The present invention can be used for various liquid ejecting apparatuses including a liquid ejecting head that ejects a minute amount of liquid droplets. In addition, a droplet means the state of the liquid discharged from the said liquid ejecting apparatus, and shall also include what pulls a tail in granular shape, tear shape, and thread shape. The liquid here may be any material that can be ejected by the liquid ejecting apparatus. For example, it may be in a state in which the substance is in a liquid phase, such as a liquid with high or low viscosity, sol, gel water, other inorganic solvents, organic solvents, solutions, liquid resins, liquid metals (metal melts ) And a liquid as one state of a substance, as well as a material in which particles of a functional material made of a solid such as a pigment or metal particles are dissolved, dispersed or mixed in a solvent. Further, representative examples of the liquid include ink and liquid crystal as described in the above embodiment. Here, the ink includes general water-based inks and oil-based inks, and various liquid compositions such as gel inks and hot melt inks. As a specific example of the liquid ejecting apparatus, for example, a liquid containing a material such as an electrode material or a color material used for manufacturing a liquid crystal display, an EL (electroluminescence) display, a surface emitting display, a color filter, or the like in a dispersed or dissolved state. It may be a liquid ejecting apparatus for ejecting, a liquid ejecting apparatus for ejecting a bio-organic material used for biochip manufacturing, a liquid ejecting apparatus for ejecting a liquid as a sample used as a precision pipette, a textile printing apparatus, a microdispenser, or the like. In addition, transparent resin liquids such as UV curable resin to form liquid injection devices that pinpoint lubricant oil onto precision machines such as watches and cameras, and micro hemispherical lenses (optical lenses) used in optical communication elements. A liquid ejecting apparatus that ejects a liquid onto the substrate or a liquid ejecting apparatus that ejects an etching solution such as an acid or an alkali to etch the substrate may be employed. The present invention can be applied to any one of these liquid ejecting apparatuses.

  S: Continuous paper as a recording medium, 11: Printer as a liquid ejecting apparatus, 18 ... Recording head as a liquid ejecting head, 20 ... Heater unit as a drying apparatus, 35 ... Air flow path section, 35a ... From a heat conducting member An inner wall as a flow path forming member, 36: a heater as a heating means, 39: an excessive temperature rise suppression sensor as an excessive temperature rise suppression means.

Claims (5)

A drying apparatus for drying the liquid attached to the recording medium by blowing heated air onto the recording medium to which the liquid is attached,
Heating means for heating the air;
A temperature sensor for detecting a temperature in an air flow path portion through which air heated by the heating means flows;
A control unit for controlling the heat generation state of the heating means based on the detection result of the temperature of the air by the temperature sensor;
Detecting the temperature in the air flow path where the air heated by the heating means flows, and supplying power to the heating means when the temperature in the air flow path exceeds a preset allowable temperature. An excessive temperature rise suppression means for blocking,
The excessive temperature rise suppression means is disposed outside the air flow path section. The said excessive temperature rising suppression means is attached to the heat conductive member which has heat conductivity, and detects the temperature in the said air flow-path part via the said heat conductive member. Drying equipment. The drying apparatus according to claim 2, wherein the heat conducting member is a flow path forming member that forms the air flow path portion. The drying apparatus according to any one of claims 1 to 3, wherein the excessive temperature rise suppression unit is arranged close to a vertical direction above the heating unit. A liquid ejecting head that performs recording by ejecting a liquid in the middle of the transport path to a recording medium transported from the upstream side to the downstream side of the transport path;
A liquid ejecting apparatus comprising: the drying apparatus according to claim 1 provided at a position downstream of the liquid ejecting head in the transport path.

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