JP5366878B2 - Inkjet recording method and apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for suppressing the nozzle drying of a recording head with moistened air. <P>SOLUTION: The moisture content of a sheet is increased by feeding a first moistened air to the sheet which is carried from a first feeding port. At the same time, the atmospheric humidity of a space is increased by feeding a second moistened air to the space where the nozzle of the inkjet recording head is exposed from a second feeding port which is installed at a position being closer to the inkjet recording head than that of the first feeding port. An area of the sheet of which the moisture content has been increased is made to advance into the space of which the atmospheric humidity has been increased, and recording is performed by the inkjet recording head. Since the sheet does not absorb moisture in the space, the humidity of the space is maintained, and the moisture keeping of the nozzle is surely performed. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to an inkjet recording method and apparatus that can suppress drying of ink of an inkjet recording head.

  In Patent Document 1, in a printer in which a plurality of inkjet recording heads are arranged side by side in the sheet conveyance direction, the recording head is moisturized by supplying humidified air from the upstream side to the vicinity of the nozzles of the recording head and flowing the ink. A technique for suppressing drying is disclosed.

JP 2000-255053 A

  A sheet made of paper or the like has an equilibrium moisture content corresponding to the humidity (the moisture content of the sheet does not change any more). If the humidity is high, it absorbs moisture in the air, and if the humidity is low, it is in the sheet. Releases moisture. When the sheet is supplied in the vicinity of the recording head in a state where the humidity is increased due to the supply of humidified air, moisture adsorption by the sheet occurs. For this reason, the humidity of the atmosphere may decrease, and the recording head may not be properly moisturized. In particular, in a configuration in which a plurality of recording heads are arranged side by side along the direction in which humidified air is introduced, it takes time until the humidified air supplied from the upstream reaches the downstream side, during which moisture is adsorbed to the sheet. Then, the moisture of the downstream recording head tends to be insufficient. Insufficient moisturization may cause ink ejection failure such as inability to eject ink or disorder in the ejection direction.

  The present invention has been made based on recognition of the above-described problems. An object of the present invention is to provide a recording apparatus capable of appropriately maintaining the moisture retention of the recording head and suppressing the ejection failure of the recording head.

A first aspect of the present invention is a recording method for recording on a sheet with an inkjet recording head having nozzles, the first step of supplying humidified air from the first supply port to the sheet, and the second supply The second step of supplying humid air from the mouth to the space where the nozzle is exposed, and the portion of the sheet whose moisture content is increased in the first step enter the space where the atmospheric humidity is increased in the second step. , possess a third step of performing recording by the ink jet recording head, the sheet is held as a continuous sheet wound into a roll, performing a decurling the sheet before giving humidified air from the first supply port to the sheet It is characterized by that.

According to a second aspect of the present invention, there is provided a recording means including an ink jet recording head provided with a nozzle, a first supply port for supplying humidified air before recording to a part for recording on a sheet, and a nozzle continuous but have a, a second supply port provided on a side closer to the ink jet recording head than the first supply port for supplying humidified air to a space to be exposed, the sheet is wound into a roll A decurling unit that is held as a sheet and decurles the sheet upstream from the first supply port is provided .

  According to the present invention, moisture adsorption by the sheet is suppressed by humidifying the sheet in advance, the moisture retention of the recording head can be properly maintained, and ink ejection failure can be suppressed.

It is a figure which shows the hysteresis characteristic of a sheet | seat. It is a block diagram of embodiment of an inkjet recording device. It is the figure which looked at the recording means from the A direction. It is a system diagram of an example of a humidifier. It is a block diagram of a control system. It is a schematic diagram of a recorded image. FIG. 6 is an enlarged schematic diagram of a recording image writing unit when recording is performed. It is a schematic block diagram of other embodiment.

  Prior to the description of embodiments of the present invention, hysteresis characteristics of a sheet as a recording medium, for example, inkjet glossy paper, will be described. FIG. 1 shows hysteresis characteristics regarding moisture adsorption and desorption. In paper such as inkjet glossy paper, the relationship between moisture adsorption and desorption due to changes in relative humidity is not linear. When the atmospheric humidity changes from point A having a low relative humidity to point B having a high relative humidity, the inkjet glossy paper adsorbs moisture in the atmosphere. On the other hand, when the relative humidity is lowered from point C having a higher relative humidity to the same relative humidity as point B, the amount of water contained in the inkjet glossy paper contains water up to the amount of point D higher than point B. That is, when the inkjet glossy paper is exposed to a certain relative atmospheric humidity, the inkjet glossy paper can contain more water when the relative humidity is changed from a lower relative humidity than when the relative humidity is changed from a lower relative humidity. Furthermore, when the relative humidity is changed from the point C having a higher relative humidity to the point D relative humidity, the amount of moisture released from the inkjet glossy paper is small. For this reason, when the inkjet glossy paper is exposed again to a relative humidity of point C or higher, the amount of moisture adsorbed by the inkjet glossy paper is smaller when changing from the D point than when changing from the B point.

  That is, if moisture is intentionally adsorbed to the sheet before it is conveyed into the recording means, it is possible to suppress the adsorption of moisture to the sheet even in a state where the relative humidity in the recording means is high. Therefore, even when the relative humidity around the recording head is increased so that the ink does not evaporate from the recording head, moisture adsorption by the sheet is suppressed, so that the relative humidity around the recording head is kept high. And drying of the ink can be suppressed. The present invention is based on such consideration.

  FIG. 2 is a configuration diagram of the ink jet recording apparatus according to the embodiment of the present invention, and FIG. 3 is a configuration diagram when the recording means 9 of the ink jet recording apparatus of FIG. 2 is viewed from the A direction. The black arrows in the figure indicate the flow of humidified humidified air. In the present embodiment, humidified air is used, but humidified gas other than air may be used. In this specification, “air” is a general term for air and gases other than air. In this specification, the direction close to the sheet supply side at an arbitrary position in the sheet conveyance path is referred to as “upstream”, and the opposite side is referred to as “downstream”.

  The recording apparatus of this example is a so-called roll-to-roll system. The supply roller 41 supplies the sheet 2 that is a continuous sheet wound in a roll shape. The take-up roller 42 takes up the sheet recorded by the recording means 9 in a roll shape.

  The recording unit 9 has a casing indicated by a dotted line in FIG. 2 and is unitized by providing a transport mechanism and a recording unit inside the casing. The transport mechanism includes a platen 7 that assists in supporting the sheet 2, and a plurality of roller pairs including a driving roller 6 and a driven roller 5. The drive roller 6 is partly embedded in the platen 7 in a rotatable state, and is rotated by a drive source to convey the sheet. The driven roller 5 is supported by a support member 8 (holder), and is disposed at a position facing the driving roller 6 with the sheet 2 interposed therebetween. A recording head 1 that constitutes a recording unit is provided between a pair of rollers of the driving roller 6 and the driven roller 5. The recording head 1 is a fixed full-line type line-type inkjet recording head in which nozzles that eject ink over the maximum recording width in the width direction of the sheet 2 are formed. The ink jet method is a method using a heating element in this example, but is not limited thereto, and is applicable to a method using a piezo element, an electrostatic element, or a MEMS (Micro Electro Mechanical Systems) element. The recording heads 1 are arranged in the conveyance direction by the number of colors (six colors in FIG. 2) along the sheet conveyance direction, and the plurality of recording heads 1 are integrally held by the support member 8. Ink is supplied to the recording head 1 from ink supply means (not shown) such as an ink tank. Each recording head 1 may be a unit integrated with an ink tank that stores ink of the corresponding color. The recording unit 9 forms an image by applying ink of each color to the moving sheet 2 by the recording head 1 of each color by a line printing method. In this example, roll paper is used as the sheet 2, but there is no limitation on the type of continuous paper or cut paper folded for each unit length.

  A first humidified air supply unit 4 (first humidifying unit) is provided upstream of the recording unit 9 in the sheet conveyance path. The first humidified air supply unit 4 humidifies the sheet 2 before the sheet 2 is conveyed to the recording unit 9. The first humidified air supply means 4 supplies humidified air (first humidified air) to the sheet 2 before entering the recording means 9 to increase the moisture content of the sheet. The first humidified air supply means 4 includes a humidifier, a blower, a supply port 43 (first supply port), and an intake port 44. The air (first humidified air) in the first humidified air supply means 4 humidified by the humidifier is ejected from the supply port 43 by the blower and supplied to the sheet 2 before entering the recording means 9. The intake port 44 may be provided at any position as long as air can be taken into the first humidified air supply means 4. An intake port 44 is provided along the sheet 2 at a position spaced from the supply port 43, and the supply port 43 supplies air humidified from a direction almost parallel to the sheet 2 (not shown). It is more preferable to provide the supply port 43. By doing in this way, since the air supplied from the supply port 43 can be sucked in from the intake port 44, the humidified air can be circulated and the amount of water used in the humidifier can be reduced.

  In addition to the first humidified air supply means 4, second humidified air supply means 3 (second humidification section) for humidifying the narrow space where the nozzles of the recording head 1 in the recording means 9 are exposed is provided. ing. The humidified air (second humidified air) is sent from the sheet introduction port of the recording means 9 by the second humidified air supply means 3 to increase the atmospheric humidity in the narrow space where the nozzles of the plurality of recording heads 1 are exposed. it can. Thereby, the nozzles of the plurality of recording heads are moisturized and drying is suppressed. The second humidified air supply means 3 is provided with a humidifier, a blower, and an intake port. A supply duct 46 is connected to the second humidified air supply means 3, and a tip of the supply duct 46 serves as a supply port 45 (second supply port) for ejecting humidified air. The supply port 45 is provided in the vicinity of the sheet introduction port of the recording unit 9 and supplies humidified air (second humidified air) from the supply port 45 to a narrow space in the recording unit 9. The supply port 43 and the intake port 44 of the first humidified air supply unit 4 are located upstream of the supply port 45 of the second humidified air supply unit 3 as viewed from the recording unit 9. Since the humidified air generated by the second humidified air supply means 3 is introduced to the supply port 45 through the supply duct 46, the humidified air generating unit of the second humidified air supply means 3 is connected to the recording means 9 and the first humidified air. It may not be located between the supply means 4.

  The humidified air supplied by the second humidified air supply unit 3 flows from upstream to downstream in the narrow path near the conveyance path of the sheet 2 and the vicinity of the recording unit 9. Specifically, at the position of the recording head 1, the recording head 1 passes through a gap (hereinafter referred to as “recording gap”) between the tip of the recording head 1 (surface on which the nozzle is formed) and the sheet 2. Further, between the adjacent recording heads 1, the humidified air passes through a gap formed between the support member 8 and the sheet 2. That is, the humidified air is transmitted to the downstream recording head 1 while passing through two types of gaps. In the ink jet system, the recording gap is usually as narrow as about 1 mm. When the humidified air passes through the recording gap, the flow rate of the humidified air increases, which adversely affects the landing accuracy of the ejected droplets (main droplets and satellite droplets) ejected from the recording head 1 during recording. May affect. Therefore, it is desirable that the humidified air supplied from the second humidified air supply means 3 is set so that the flow velocity in the recording gap is 1 m / second or less.

  FIG. 4 is a system diagram of a humidifier that supplies humidified air to the first humidified air supply means 4 and the second humidified air supply means 3. The outside air 51 and the dry air supplied from the drying unit 52 are mixed in the mixer 53 to become mixed air having a temperature suitable as humidified air. The drying unit 52 is a unit for forcibly drying the sheet recorded by the recording means 9 and wet with ink before being wound around the winding roller 42 (not shown in FIG. 2). High-humidity and high-temperature air is discharged from the drying unit 52, and a part of this energy is used to generate humidified air. In the humidifier 55, the mixed air sent from the mixer 53 and the water supplied from the water tank 54 are mixed, and humidified air having a temperature and humidity necessary for supplying the humidified air to the sheet 2 is produced. Humidified air produced by the humidifier 55 is temporarily stored in the humidified air tank 56. Then, a required amount of humidified air at the time of recording is sent to the first humidified air supply means 4 and the second humidified air supply means 3, respectively, so that the humidified air supply means can obtain the required humidification performance. Be operated. In addition, the heater is arrange | positioned in the mixer 53 and the humidifier 55, and can finely adjust mixed air and humidification air to optimal temperature.

  The humidity of the 1st humidification air supplied from the 1st humidification air supply means 4 and the 2nd humidification air supplied from the 2nd humidification air supply means 3 is demonstrated. The atmosphere around the recording head 1 needs to be an atmosphere in which ink does not easily evaporate from the recording head 1. For example, if the temperature is 30 to 40 ° C., the relative humidity is about 60 to 70%. For this reason, in the second humidified air supply means 3, it is preferable to set the relative humidity to about 60 to 70%, but this is not limited as long as the ink can be prevented from evaporating from the recording head 1. In the 1st humidification air supply means 4, it is preferable to make a sheet | seat 2 adsorb | suck a water | moisture content so that it may become an equilibrium moisture content. Since the amount of moisture that can be adsorbed varies depending on the type of the sheet 2, as a guideline, air that has been humidified to an absolute humidity equal to or higher than the absolute humidity of the humidified air supplied from the second humidified air supply means 3 is used. What is necessary is just to supply to the sheet | seat 2 from the 1st humidification air supply means 4.

  FIG. 5 is a block diagram of a control system of the ink jet recording apparatus of this example. Character or image data to be recorded is input from the host computer 10 to the reception buffer 11 of the ink jet recording apparatus. Further, data for confirming whether the data is correctly transferred, and data for notifying the operation state of the ink jet recording apparatus are output from the ink jet recording apparatus to the host computer 10. The data in the reception buffer 11 is transferred to the memory unit 13 and temporarily stored in the RAM under the control of the CPU 12 as a control unit. The mechanical control unit 14 drives a mechanical unit (mechanical unit) 15 such as a line head carriage, a cap, and a wiper in response to a command from the CPU 12. The sensor / SW (switch) control unit 16 sends a signal from the sensor / SW unit 17 including various sensors and SW (switch) to the CPU 12. The display element control unit 18 controls the display element unit 19 composed of an LED of a display panel, a liquid crystal display element, and the like according to a command from the CPU 12. The humidification control unit 20 controls the humidified air supply unit (first humidified air supply unit 4, second humidified air supply unit 3) 21 according to a command from the CPU 12. At this time, the CPU 12 determines the amount of moisture to be supplied to the sheet 2 from various information, for example, the environmental temperature, the type and thickness of the sheet 2, the temperature of the line head, and the amount of image data to be recorded. The humidification condition of the humidified air supply unit 21 is set. The recording head control unit 22 drives and controls the recording head 1 according to a command from the CPU 12, detects temperature information indicating the state of the recording head 1, and transmits the detected temperature information to the CPU 12.

  In the above configuration, the first humidified air supply unit 4 is provided upstream of the recording unit 9 in the sheet conveyance path, and supplies the first humidified air to the sheet before entering the recording unit 9. This increases the moisture content of the sheet before entering the recording means 9. The second humidified air supply means 3 supplies the second humidified air from the sheet introduction port so that the humidified air flows from the upstream side to the downstream side along the conveyance path of the recording means 9. In the recording unit 9, the second humidified air is sent in advance before the sheet is introduced to increase the atmospheric humidity in a narrow space where the nozzles of the recording head 1 are exposed, and the recording head is moisturized. Further, when viewed as an operation, in the first step, the first humidified air is supplied from the first supply port to the conveyed sheet to increase the moisture content of the sheet. At the same time, in the second step, the second humidified air is supplied from a second supply port provided closer to the recording head than the first supply port to the narrow space where the nozzles are exposed, thereby reducing the atmosphere in the narrow space. Increase the humidity and keep the nozzle moist. In the third step, the portion of the sheet whose water content is increased in the first step is entered into the narrow space where the atmospheric humidity is increased in the second step, and recording is performed with the ink jet recording head.

  As a result, when the sheet passes through the space during recording, the sheet is in a state where the moisture content has been increased by the first humidified air in advance, so that the sheet absorbs the moisture of the second humidified air. Is suppressed. Therefore, high humidity is maintained in the narrow space from the upstream recording head to the downstream recording head, and the nozzle is reliably moisturized. As a result, it is possible to suppress the occurrence of ink discharge defects such as ink being unable to be discharged or the discharge direction being disturbed.

(Other embodiments)
Another embodiment will be described with reference to FIG. In addition, description is abbreviate | omitted about the structure same as the above-mentioned embodiment. In this embodiment, a decurling unit 23 is provided between the supply roller 41 that supplies the sheet 2 and the recording unit 9. That is, the first humidified air supply means 4 is located closer to the recording means 9 than the decurling means 23. The decurling means 23 includes a heater for heating the sheet. By conveying the sheet while being heated by the heater of the decurling means 23, the curling of the sheet wound around the supply roller 41 is corrected. Decals are made more effective by heating with a heater.

  If the first humidified air supply unit 4 is disposed between the decurling unit 23 and the supply roller 41, the sheet is decurled after the moisture is supplied from the first humidified air supply unit 4 to the sheet surface by the humidified air. Will pass. The sheet is heated by the heater of the decurling means 23, so that much of the moisture of the adsorbed sheet evaporates, and the sheet returns to a state in which a large amount of moisture can be adsorbed. When the sheet passes through the recording means 9, the sheet adsorbs a large amount of moisture in a narrow space, and the atmospheric humidity is lowered. For this reason, the moisture retention of the recording head 1 becomes incomplete, and the tendency becomes remarkable particularly near the tip of the recording head 1 on the most downstream side.

  In order to avoid such a situation, the first humidified air supply means 4 is disposed between the decurling means 23 and the recording means 9. That is, the decurling unit 23 is disposed upstream of the first supply port 43 of the first humidified air supply unit 4 in the sheet conveyance path. As shown in FIG. 8, it is preferable that the first humidified air supply means 4 is disposed adjacent to the recording means 9 as much as possible. This is because the time from when the sheet 2 adsorbs moisture by the first humidified air supply means 4 to the time when it reaches the recording means 9 is shortened, and moisture evaporation can be suppressed to a low level.

  Below, the example experimented using the inkjet recording device of the above-mentioned structure is demonstrated.

Example 1
The recording head 1 has six colors of black, cyan, photocyan, magenta, photomagenta, and yellow having a recording width of 6 inches. As sheet 2, glossy roll paper for ink jet having a width of 5 inches was set, and continuous image recording with an image size of 5 × 7 inches was performed. At this time, the atmosphere around the ink jet recording apparatus was a temperature of 25 ° C. and a relative humidity of 55%. Regarding the moisture content of the roll paper which is the sheet 2, when the moisture content of the roll paper was measured using an electric moisture meter (main body: MR-200, probe: KG-PA) manufactured by Sanko Electronics Laboratory Co., Ltd. About 6%. Prior to image recording, the ink in the nozzles was refreshed by performing “disposal discharge” of the recording head 1 in the cap, and then the cap was retracted and the recording head 1 was moved to the image recording position.

  In parallel with the above series of operations, the second humidified air supply means 3 began to send air at a temperature of 30 ° C. and a relative humidity of 85% into the recording means 9 at a speed of 0.2 m / s. At this time, the wind speed under the recording head 1 is 0.9 m / second, and the flow velocity at which the landing droplets are not deteriorated in accuracy and the problem that the satellite droplets land after being separated from the main droplets is not caused. Met. Note that since the dew point of air having a temperature of 30 ° C. and a relative humidity of 85% is 27 ° C., the second humidified air supply means 3 starts after the temperature in the recording device exceeds 27 ° C. after the operation of the ink jet recording device is started. The supply of humidified air was started. A specific atmosphere in the recording apparatus was a temperature of 32 ° C. and a relative humidity of 37%. In the ink jet recording apparatus, the temperature inside the apparatus rises by adjusting the temperature of the recording head 1 or using a dryer, etc. However, if the temperature outside the apparatus is low, such as in winter, it takes time until the apparatus warms up. A heating means such as a heater may be provided separately.

Next, the air humidified to a temperature of 30 ° C. and a relative humidity of 85% (absolute humidity of 25.8 g / m ³ ) by the first humidified air supply means 4 is supplied through a supply port 43 of 150 × 40 mm at a speed of 1.3 m / s. It was supplied to the roll paper surface. At this time, the amount of water supplied to the roll paper is about 0.2 g / sec, and the amount of water supplied increases to about 720 g per hour. In such a case, as described above, it is desirable to configure a circulation system in which the air supplied from the supply port 43 returns to the intake port 44. When the moisture content of the roll paper humidified by the first humidified air supply means 4 was measured, it was about 13%.

  As described above, the temperature and relative humidity in the vicinity of the front end of the recording head 1 were measured in a state where the humidified air was supplied from the first humidified air supply unit 4 and the second humidified air supply unit 3. As a result, the most upstream recording head 1 has a temperature of 30 ° C. and a relative humidity of 80%, and the most downstream recording head 1 has a temperature of 30 ° C. and a relative humidity of 75%. It was found that humidification was performed over the entire area where the was placed.

  In this state, the conveyance of the glossy paper roll as the sheet 2 was started, and a plurality of types of recorded images 32 including a recorded image having an image size of 5 × 7 inches were recorded as shown in FIG. Between the recorded images 32, “discarded discharge 31” was performed, and continuous recording was performed at a speed of 1.5 inches per second. As a result, also in the writing unit 34 of the recorded image 32 when the nozzle that was not used is used, the landing accuracy from the first shot of the recording dot is the same as the writing unit 33 of the recorded image 32 of the nozzle that has been used. As a result, an image having no problem in density was obtained (see FIG. 7A).

(Example 2)
In Example 1, the air was humidified by the first humidified air supply means 4 except that the temperature was 40 ° C. and the relative humidity was 60% (absolute humidity 30.6 g / m ³ ). The recording was performed on sheet 2. Note that the amount of water supplied to the roll paper at this time is about 0.24 g / sec. When the moisture content of the roll paper humidified by the first humidified air supply means 4 was measured, it was about 15%.

  Further, the temperature and relative humidity in the vicinity of the front end of the recording head 1 were measured in a state where the humidified air was supplied from the first humidified air supply unit 4 and the second humidified air supply unit 3. As a result, the most upstream recording head 1 has a temperature of 30 ° C. and a relative humidity of 95%, and the most downstream recording head 1 has a temperature of 30 ° C. and a relative humidity of 90%. It turned out that it was humidified over a long time.

  In this state, an image was recorded in the same manner as in Example 1. As a result, similarly to the writing unit 33 of the recording image 32 of the nozzle that was used in the writing unit 34 of the recording image 32 when the nozzle that was not used was used, the recording dots from the first dot of the recording dot are recorded. An image having no problem in both landing accuracy and density was obtained (see FIG. 7A).

(Comparative Example 1)
In Comparative Example 1, unlike Example 1, the humidified air was not supplied to the roll paper by the first humidified air supply means 4, and recording was performed on the roll paper in the same manner as in Example 1 except for that. . That is, the conditions are almost the same as those of the prior art (Patent Document 1).

  With the humidified air supplied only from the second humidified air supply means 3, the temperature and relative humidity near the tip of the recording head 1 were measured. As a result, the most upstream recording head 1 had a temperature of 30 ° C. and a relative humidity of 70%, and the most downstream recording head 1 had a temperature of 30 ° C. and a relative humidity of 45%.

  In Comparative Example 1, since the moisture is not intentionally supplied to the roll paper by the first humidified air supply means 3, the moisture in the air in the recording means 9 is absorbed by the roll paper, and before the recording is started. The humidity near the tip of the recording head 1 is lower than in the first and second embodiments. In particular, the tendency is remarkable near the tip of the recording head 1 on the most downstream side.

  In this state, an image was recorded in the same manner as in Example 1. As a result, a problem-free image (see FIG. 7A) was obtained in the writing portion 33 of the recorded image 32 of the nozzle used. However, in the writing unit 34 of the recorded image 32 when the nozzles that were not used were used, the landing accuracy of the recorded dots was lowered and the density was not constant as shown in FIG. 7B.

  According to the above recording apparatus, before the sheet 2 is fed into the recording means 9, the moisture is supplied to the sheet 2 by the first humidified air supply means 4 and is humidified by the second humidified air supply means 3. Is supplied into the recording means 9, and the periphery of the recording head 1 is humidified. If the sheet 2 is supplied into the recording means 9 in this state, the sheet 2 can be prevented from adsorbing moisture around the recording head 1. Therefore, even during the recording operation, it is possible to maintain a high atmospheric humidity from the most upstream recording head 1 to the most downstream recording head 1. Therefore, it is possible to prevent the water in the ink from evaporating from the inside of the recording head 1, and it is possible to suppress a decrease in the landing accuracy of the recording dots and a change in the color tone even when a nozzle that has not been used is used.

DESCRIPTION OF SYMBOLS 1 Recording head 2 Sheet | seat 3 2nd humidification air supply means 4 1st humidification air supply means 9 Recording means

Claims (9)

A recording method for recording on a sheet with an inkjet recording head having a nozzle,
A first step of supplying humidified air from the first supply port to the sheet;
A second step of supplying humidified air from a second supply port to a space where the nozzle is exposed;
A third step of performing recording with the inkjet recording head by causing the portion of the sheet whose moisture content has been increased in the first step to enter the space in which the atmospheric humidity has been increased in the second step;
Have
The recording method is characterized in that the sheet is held as a continuous sheet wound in a roll shape, and the sheet is decurled before the humidified air is supplied from the first supply port to the sheet . A plurality of the inkjet recording heads are held side by side from upstream to downstream along the direction in which the sheet is conveyed,
In the second step, a part of the humidified air supplied from the second supply port causes a narrow space including a space between the nozzles and the sheets of the plurality of recording heads from the upstream toward the downstream. The recording method according to claim 1, wherein the recording method flows.   The recording method according to claim 2, wherein the flow rate of the humidified air supplied from the second supply port is 1 m / second or less in a gap between the sheet and the nozzle. A recording method for recording on a sheet with an inkjet recording head having a nozzle,
A first step of supplying humidified air from the first supply port to the sheet;
A second step of supplying humidified air from a second supply port to a space where the nozzle is exposed;
A third step of performing recording with the inkjet recording head by causing the portion of the sheet whose moisture content has been increased in the first step to enter the space in which the atmospheric humidity has been increased in the second step;
Have
The absolute humidity of the humidified air supplied from the first supply port, said second record how to being higher than the absolute humidity of the humidified air supplied from the supply port. A recording method for recording on a sheet with an inkjet recording head having a nozzle,
A first step of supplying humidified air from the first supply port to the sheet;
A second step of supplying humidified air from a second supply port to a space where the nozzle is exposed;
A third step of performing recording with the inkjet recording head by causing the portion of the sheet whose moisture content has been increased in the first step to enter the space in which the atmospheric humidity has been increased in the second step;
Have
In the first step, record how to characterized by humidifying the sheet until an equilibrium water content in the humidified air. The recording method according to claim 1, wherein the sheet is heated at the time of decaling. A recording means including an ink jet recording head provided with a nozzle;
A first supply port for supplying humidified air before recording to a part for recording on the sheet;
Have a, a second supply port provided on a side closer to the ink jet recording head than the nozzle for supplying the humidified air to a space to be exposed, said first supply port,
The recording apparatus is characterized in that the sheet is held as a continuous sheet wound in a roll shape, and provided with decurling means for decurling the sheet upstream from the first supply port . In the recording means, the plurality of inkjet recording heads are held side by side from upstream to downstream along the direction in which the sheet is conveyed,
A part of the humidified air supplied from the second supply port flows in a narrow space including a space between the nozzles of the plurality of recording heads and the sheet from the upstream toward the downstream. The recording apparatus according to claim 7. The recording apparatus according to claim 7 , wherein the decurling unit includes a heater for heating the sheet during decurling.

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