JP2012035566A - Image forming apparatus - Google Patents

Abstract

An image forming apparatus capable of suppressing cockling (waving) generated on a recording medium (paper) on which an image is formed without being influenced by a liquid material used to form an image.
A seasoning device 56 provided so as to face a discharge drum 52 has an atmosphere humidity (for example, 50 to 60% RH) and an atmosphere outside the apparatus main body 10A on a sheet P conveyed by the discharge drum 52. Air (humidified air) adjusted to a temperature (for example, 20 to 25 ° C.) is blown. Thereby, the drying strength in the apparatus main body 10A is weakened. That is, in the non-drawing part, the water lost by the drying part 18 is recovered. As described above, the drying strength with respect to the paper P is weakened in the apparatus main body 10A, so that the difference in water amount between the drawing unit and the non-drawing unit is reduced. Thereby, cockling (rippling) occurring on the paper P can be suppressed.
[Selection] Figure 1

Description

  The present invention relates to an image forming apparatus.

  In patent document 1, in the printed matter by heat set printing which is a kind of offset printing, the stress inside the dry film of the ink is relieved by generating a certain amount of microcracks that are minute cracks in the image line portion of the printed matter, It is described that wrinkles generated by fixing with a dry film are reduced.

JP 2007-177081 A

  However, in the prior art, the components of the liquid (ink) material used to form an image are limited.

  An object of the present invention is to suppress cockling (rippling) that occurs on a recording medium (paper) on which an image is formed, regardless of the liquid material used to form the image.

  An image forming apparatus according to a first aspect of the present invention includes a conveying unit that conveys a recording medium, and a droplet ejection head that ejects droplets onto the recording medium conveyed by the conveying unit to form an image on the recording medium. A drying unit that dries a recording medium on which an image is formed by droplets ejected by the droplet ejection head, and a spray unit that blows air humidified on the recording medium dried by the drying unit to the recording medium; It is characterized by providing.

  According to the above configuration, the droplets ejected from the droplet ejection head form an image on the recording medium that is conveyed by the conveying unit.

  Further, the drying means dries the recording medium on which the image is formed (decreases moisture contained in the recording medium), and enhances the film quality of the image. Further, the spraying means sprays humidified air onto the recording medium dried (moisture decreased) by the drying means.

  In this way, by spraying humidified air on the recording medium, the drying strength on the recording medium is weakened, so that the difference in moisture content between the drawing portion where the image is formed and the non-drawing portion where the image is not formed is reduced. Decrease. Thereby, cockling (rippling) generated in the recording medium can be suppressed without being influenced by the liquid material used for forming the image.

  An image forming apparatus according to a second aspect of the present invention is the image forming apparatus according to the first aspect, wherein the spraying unit blows air adjusted to an atmospheric humidity and an atmospheric temperature outside the apparatus.

  According to the above configuration, the spraying unit sprays the air adjusted to the atmospheric humidity and the atmospheric temperature outside the apparatus onto the recording medium. Accordingly, it is possible to prevent cockling (waving) generated in the recording medium while preventing the drawing portion from being adversely affected.

  An image forming apparatus according to a third aspect of the present invention is the image forming apparatus according to the first or second aspect, wherein the conveying unit includes a plurality of conveying members that sequentially convey the recording medium, and discharges the recording medium to the outside of the apparatus. The spraying means is arranged to blow air onto a recording medium transported by a transport member.

  According to the above configuration, the spraying unit sprays air onto the recording medium transported by the transporting member that discharges the recording medium to the outside of the apparatus. That is, since air is blown onto the recording medium at a position away from the drying means, the humidity and temperature of the air are prevented from being affected by the drying means. Thereby, it is possible to easily manage the humidity and temperature of the air sprayed by the spraying means onto the recording medium.

  The image forming apparatus according to a fourth aspect of the present invention is the image forming apparatus according to any one of the first to third aspects, wherein the spraying unit extends in a direction intersecting with a conveyance direction of the recording medium. .

  According to the above configuration, the spraying means extends in a direction intersecting with the conveyance direction of the recording medium. Thereby, humidified air can be blown over the width direction of the recording medium.

  The image forming apparatus according to a fifth aspect of the present invention is the image forming apparatus according to any one of the first to fourth aspects, wherein the spraying unit includes a water pipe in which a jet port from which mist is ejected is formed, and water in the water pipe. A water supply device for supplying the air, a blower for blowing the air humidified by the mist blown from the jet outlet of the water pipe to the recording medium, and a temperature adjusting member for adjusting the temperature of the air blown by the blower. It is characterized by.

  According to the said structure, a water supply apparatus supplies water to a water pipe, and mist spouts from the spout of a water pipe. Then, the blower blows air that has been humidified by the mist blown out from the water nozzle outlet onto the recording medium. The temperature adjusting member adjusts the temperature of the air blown by the blower.

  Thus, humidified air can be blown onto the recording medium with a simple configuration.

  An image forming apparatus according to a sixth aspect of the present invention is the image forming apparatus according to the fifth aspect, wherein a temperature detection member for detecting an ambient temperature outside the apparatus is provided, and the temperature adjustment member is adjusted based on a detection signal from the temperature detection member. A control unit for controlling is provided.

  According to the above configuration, the temperature detection member detects the ambient temperature outside the apparatus. And a control part controls a temperature control member based on the detection signal from a temperature detection member.

  Thus, with a simple configuration, the air adjusted to the ambient temperature outside the apparatus can be blown onto the recording medium.

  An image forming apparatus according to a seventh aspect of the present invention is the image forming apparatus according to the sixth aspect, wherein a temperature detecting member for detecting an ambient temperature outside the apparatus is provided, and the temperature adjusting member is disposed on the basis of a detection signal from the temperature detecting member. A control unit for controlling is provided.

  According to the above configuration, the humidity detection member detects the atmospheric humidity outside the apparatus. And a control part adjusts the amount of water which a water supply apparatus supplies to a water pipe | tube based on the detection signal from a humidity detection member.

  In this way, air adjusted to the atmospheric humidity outside the apparatus can be blown onto the recording medium with a simple configuration.

  An image forming apparatus according to an eighth aspect of the present invention is the image forming apparatus according to the sixth or seventh aspect, wherein the control unit adjusts a driving force of the blower according to a conveyance speed of the recording medium.

  According to the above configuration, since the control unit adjusts the driving force of the blower according to the conveyance speed of the recording medium, the amount of air blown onto the recording medium can be set to the optimum amount according to the conveyance speed of the recording medium. .

  The image forming apparatus according to a ninth aspect of the present invention is the image forming apparatus according to any one of the sixth to eighth aspects, wherein the control unit selectively opens and closes the outlet of the water pipe according to the size of the recording medium. It is characterized by controlling.

  According to the above configuration, the control unit selectively controls the opening and closing of the water pipe jet outlet according to the size of the recording medium. For this reason, the humidified air can be blown only to the recording medium, and the humidified air can be prevented from being blown to the conveying means.

  An image forming apparatus according to a tenth aspect of the present invention is the image forming apparatus according to any one of the first to ninth aspects, wherein the air on the drying means side is between the spraying means and the drying means. A shielding plate that suppresses inflow to the side is provided.

  According to the above configuration, the shielding plate is provided between the spraying means and the drying means to suppress the air on the drying means side from flowing into the spraying means side. For this reason, it can suppress that the humidified air sprayed on a recording medium by a spraying means dries.

  According to the present invention, cockling (rippling) that occurs in a recording medium on which an image is formed can be suppressed without being affected by the liquid material used to form the image.

1 is a side view showing a seasoning device used in an image forming apparatus according to an embodiment of the present invention. 1 is a perspective view showing a seasoning device used in an image forming apparatus according to an embodiment of the present invention. 1 is a schematic configuration diagram illustrating an image forming apparatus according to an embodiment of the present invention.

  An example of the image forming apparatus 10 according to the embodiment of the present invention will be described with reference to FIGS. In addition, arrow UP in a figure shows the perpendicular direction upper direction.

(overall structure)
As shown in FIG. 3, the image forming apparatus 10 includes a paper feeding unit 12 that supplies a sheet P as a recording medium to the apparatus main body 10 </ b> A, and a processing liquid application unit 14 that applies a processing liquid to the image forming surface of the paper P. An image recording unit 16 for forming an image on the paper P, a drying unit 18 for drying the paper P (reducing moisture) in order to enhance the film quality of the drawing unit on which the image is formed, and a formed image. A fixing unit 20 that fixes the paper P and a discharge unit 22 that discharges the paper P are provided.

  Then, the paper P is stacked on the paper feed unit 12, and the paper feed unit 12 sends the paper P one by one toward the apparatus main body 10A. Further, on the downstream side of the paper feeding direction with respect to the paper feeding unit 12 (hereinafter simply referred to as the downstream side), the paper feeding tray 24 guides the paper P sent out from the paper feeding unit 12 toward the apparatus main body 10A. Is provided. Further, on the downstream side of the paper feed tray 24, a paper feed drum 26 is provided in the apparatus main body 10A to convey the paper P along the outer peripheral surface while rotating. Then, the paper P is conveyed to the processing liquid application unit 14 by the paper supply drum 26.

  Further, the treatment liquid application unit 14 is provided with a treatment liquid application drum 28 that receives the paper P conveyed by the paper supply drum 26 while rotating and conveys the paper P along the outer peripheral surface. Specifically, a holding member 30 that holds the leading end of the paper P is provided on the outer peripheral surface of the treatment liquid coating drum 28. With this configuration, the sheet P is transported to the downstream side by the rotation of the treatment liquid coating drum 28 while the leading end of the sheet P is held by the holding member 30.

  In addition, a processing liquid coating device 32 that coats the processing liquid on the image forming surface of the paper P conveyed by the processing liquid coating drum 28 is provided above the processing liquid coating drum 28. The treatment liquid has an effect of accelerating separation of the color material (pigment) and the solvent by reacting with droplets described later to aggregate the color material (pigment).

  Further, on the downstream side of the processing liquid coating drum 28, there is provided a transport drum 34 that receives the paper P transported by the processing liquid coating drum 28 while rotating it and transports it toward the image recording unit 16.

  The image recording unit 16 is provided with an image recording drum 36 that receives the paper P conveyed by the conveying drum 34 while rotating and conveys the paper P along the outer peripheral surface. Further, above the image recording drum 36, a droplet discharge head 38 that forms an image on the paper P by discharging droplets such as ink onto the paper P conveyed by the image recording drum 36 is provided. The droplet discharge head 38 is a so-called full line head having an ink discharge range corresponding to the maximum width of the paper P. In the present embodiment, as an example, four color droplet discharge heads 38 of basic colors Y (yellow), M (magenta), C (cyan), and K (black) are arranged in the circumferential direction of the image recording drum 36. Are arranged along.

  Further, a transport drum 40 that receives the paper P transported by the image recording drum 36 and transports it toward the drying unit 18 is provided on the downstream side of the image recording drum 36.

  In addition, the drying unit 18 is provided with a drying drum 42 that receives the paper P conveyed by the conveying drum 40 while rotating and conveys the paper P along the outer peripheral surface. Above the drying drum 42, a halogen heater 44 and a hot air nozzle 46 as an example of a drying unit are arranged. While the paper P is being transported by the drying drum 42, the moisture contained in the paper P is strengthened by the heat from the halogen heater 44 and the hot air from the hot air nozzle 46 in order to enhance the film quality of the drawing portion where the image is formed. , Is supposed to decrease (becomes dry). Thereby, the film quality strength of the image formed on the paper P is improved.

  Further, on the downstream side of the drying drum 42, a conveyance drum 48 that receives the paper P conveyed by the drying drum 42 and conveys the paper P toward the fixing unit 20 is provided.

  The fixing unit 20 is provided with a fixing drum 50 that receives the paper P conveyed by the conveying drum 48 while rotating and conveys the paper P along the outer peripheral surface. Then, a heating (preheating) halogen heater 62, a fixing roller 64 that presses the paper P against the fixing drum 50 so as to face the outer peripheral surface of the fixing drum 50, a check pattern and a moisture amount on the paper P, And an in-line sensor 66 for measuring surface temperature, glossiness, and the like.

  A discharge drum 52 is provided on the downstream side of the fixing drum 50 to receive the paper P conveyed by the fixing drum 50 while rotating and discharge the received paper P to the outside of the apparatus main body 10A. Further, a seasoning device 56 is provided as an example of a spraying unit that blows humidified air onto the paper P dried (moisture reduced) by the halogen heater 44 and the hot air nozzle 46 so as to face the outer peripheral surface of the discharge drum 52. It has been. Details of the seasoning device 56 will be described later.

  A guide plate 54 formed in a curved shape for guiding the paper P to the outside of the apparatus main body 10A is provided on the downstream side of the discharge drum 52.

  Further, a stacking unit 68 on which the paper P discharged outside the apparatus main body 10 </ b> A by the discharge drum 52 is stacked is provided in the discharge unit 22.

(Main part configuration)
Next, the seasoning device 56 disposed so as to face the outer peripheral surface of the discharge drum 52 will be described.

  As shown in FIG. 1, the seasoning device 56 disposed so as to face the paper P conveyed by the discharge drum 52 includes a plurality of (three in this embodiment) blowers 60 that blow air onto the paper P. And a temperature adjusting member 70 that adjusts the temperature of air blown onto the paper P by the blower 60.

  Specifically, as shown in FIGS. 1 and 2, the plurality of blowers 60 are arranged and transported along the rotation axis direction of the discharge drum 52 (direction intersecting the transport direction of the paper P). Air is blown over the entire surface of the paper P to be printed. Further, a water pipe 58 constituting a seasoning device 56 is provided between the blower 60 and the discharge drum 52. A water supply device 72 for supplying water to the water pipe 58 is provided. A plurality of jets (not shown) are formed on the outer peripheral surface of the water pipe 58 to inject the flowing water in a mist (mist) form.

  Further, a temperature detection member 76 for detecting the ambient temperature outside the apparatus and a humidity detection member 78 (see FIG. 30) for detecting the atmospheric humidity outside the apparatus are provided outside the apparatus main body 10A.

  The seasoning device 56 is provided with a control unit 80, which controls the temperature adjustment member 70 based on a detection signal from the temperature detection member 76 and detects from the humidity detection member 78. Based on the signal, the amount of water supplied from the water supply device 72 to the water pipe 58 is controlled.

  Further, the control unit 80 adjusts the driving force of the blower 60 according to the conveyance speed of the paper P, and selectively controls the opening and closing of the outlet of the water pipe 58 according to the size of the paper P. .

  That is, the temperature, humidity, air volume, and blowing range of the humidified air blown onto the paper P by the seasoning device 56 are controlled by the control unit 80.

  With this configuration, in the present embodiment, the air blown onto the paper P by the seasoning device 56 becomes the atmospheric humidity (for example, 50 to 60% RH) and the atmospheric temperature (for example, 20 to 25 ° C.) outside the apparatus main body 10A. In this way, the control unit 80 controls.

  Further, a shielding plate 82 is provided between the halogen heater 44 and the hot air nozzle 46 and the seasoning device 56 to prevent the air on the drying unit 18 side from flowing into the seasoning device 56 side.

(Action / Effect)
As shown in FIG. 3, the paper P fed from the paper feed unit 12 is conveyed along the outer peripheral surfaces of the rotating paper feed drum 26 and the treatment liquid coating drum 28. In the treatment liquid application unit 14, the treatment liquid application device 32 applies the treatment liquid to the image forming surface of the paper P conveyed along the outer peripheral surface of the treatment liquid application drum 28.

  Further, the paper P coated with the treatment liquid is conveyed along the outer peripheral surfaces of the rotating conveyance drum 34 and the image recording drum 36. In the image recording unit 16, each color droplet ejection head 38 ejects droplets of ink or the like onto the image forming surface of the paper P conveyed by the image recording drum 36 to form an image on the paper P.

  Further, the paper P on which an image is formed on the image forming surface is conveyed along the outer peripheral surfaces of the rotating conveyance drum 40 and the drying drum 42. In the drying unit 18, the paper P is dried by the heat of the halogen heater 44 and the hot air blown from the hot air nozzle 46 (the moisture contained in the paper P is reduced).

  Further, the paper P heated to a high temperature by the heat of the halogen heater 44 and the warm air blown from the warm air nozzle 46 is transported along the outer peripheral surfaces of the rotating transport drum 48 and the fixing drum 50. In the fixing unit 20, the image formed on the paper P is fixed on the paper P by being in pressure contact with the fixing drum 50 and the fixing roller 64 heated by the halogen heater 62 provided oppositely. Further, the sheet P passes through the facing portion of the inline sensor 66. The inline sensor 66 measures a check pattern, moisture amount, surface temperature, glossiness, and the like on the passing paper P.

  The paper P measured by the inline sensor 66 is conveyed along the outer peripheral surface of the rotating discharge drum 52, guided by the guide plate 54, and provided in the discharge portion 22 outside the apparatus main body 10A. Is discharged.

  Here, when the paper P is dried by the drying unit 18 after the image is formed (when the water content of the paper P is reduced), the amount of water between the drawing unit where the water content of the liquid droplets is present and the non-drawing unit where the water content of the liquid droplets is not present It is conceivable that cockling (waving) occurs in the paper P due to the difference between the two.

  That is, if the paper P is left in the atmosphere (outside of the apparatus main body 10A), the water content of the drawing unit settles at a predetermined value even if the drying strength (degree of strength for drying the paper P) is different. However, the amount of water in the non-drawing portion varies depending on the strength of the drying strength. As a result, it is conceivable that as the drying strength inside the apparatus main body 10A is increased, the difference in moisture content between the drawing portion and the non-drawing portion increases, and cockling deteriorates.

  However, as shown in FIGS. 1 and 2, the control unit 80 of the seasoning device 56 provided to face the discharge drum 52 controls the temperature based on the detection signals of the temperature detection member 76 and the humidity detection member 78. By controlling the water supply amount of the member 70 and the water supply device 72, the atmospheric humidity (for example, 50 to 60% RH) and the atmospheric temperature (for example, 20 to 20%) outside the apparatus main body 10A are applied to the paper P conveyed by the discharge drum 52. Blowing air adjusted to 25 ° C. (humidified air).

  Thereby, the drying strength in the apparatus main body 10A is weakened. That is, in the non-drawing part, the water lost by the drying part 18 is recovered.

  As described above, the drying strength with respect to the paper P is weakened in the apparatus main body 10A, so that the difference in water amount between the drawing unit and the non-drawing unit is reduced. Thereby, cockling (rippling) generated on the paper P can be suppressed without being influenced by the liquid material used for forming the image.

  Moreover, it can prevent having a bad influence on the drying with respect to a drawing part by spraying air of atmospheric humidity (for example, 50-60% RH) and atmospheric temperature (for example, 20-25 degreeC).

  The seasoning device 56 blows air onto the paper P conveyed by the discharge drum 52 that discharges the paper P to the outside of the apparatus main body 10A. That is, since air is blown onto the paper P at a position away from the drying unit 18, the humidity and temperature of the air are not easily affected by the drying unit 18. As a result, it is possible to easily manage the humidity and temperature of the air that the seasoning device 56 blows onto the paper P.

  Further, the seasoning device 56 extends in a direction that intersects the transport direction of the paper P. Thereby, humidified air can be blown over the width direction of the paper P.

  Further, since the control unit 80 adjusts the driving force of the blower 60 according to the conveyance speed of the paper P, the amount of air blown onto the paper P can be set to an optimum amount according to the conveyance speed of the paper P.

  Further, since the control unit 80 selectively controls the opening and closing of the water pipe jet outlet according to the size of the paper P, it is possible to blow humidified air only on the paper P, and the humidified air is blown onto the discharge drum 52. Can be suppressed.

  A shielding plate 82 is provided between the halogen heater 44 and the hot air nozzle 46 and the seasoning device 56 to prevent the air on the drying unit 18 side from flowing into the seasoning device 56 side. For this reason, it is possible to suppress drying of the humidified air blown onto the paper P by the halogen heater 44 and the hot air nozzle 46.

  Although the present invention has been described in detail with respect to specific embodiments, the present invention is not limited to such embodiments, and various other embodiments are possible within the scope of the present invention. It is clear to the contractor. For example, in the above embodiment, although not particularly mentioned, 10-30 μm powder (an anti-adhesion agent for paper) is sprayed from the water pipe 58 in order to prevent blocking after paper discharge (adhesion between papers). May be mixed in fog.

10 Image forming apparatus 28 Treatment liquid coating drum (conveying member)
34 Conveying drum (conveying member)
36 Image recording drum (conveyance member)
38Y Droplet discharge head 38M Droplet discharge head 38C Droplet discharge head 38K Droplet discharge head 40 Transport drum (transport member)
42 Drying drum (conveying member)
44 Halogen heater (drying means)
46 Hot air nozzle (drying means)
48 Conveying drum (conveying member)
50 Fixing drum (conveying member)
52 Discharge drum (conveying member)
56 Seasoning device (spraying means)
58 Water pipe 60 Blower 70 Temperature control member 72 Water supply device 76 Temperature detection member 78 Humidity detection member 80 Control part 82 Shielding plate

Claims (10)

Conveying means for conveying the recording medium;
A liquid droplet ejection head for ejecting liquid droplets onto a recording medium conveyed by the conveying means to form an image on the recording medium;
Drying means for drying a recording medium on which an image is formed by droplets ejected by the droplet ejection head;
Spraying means for blowing air humidified onto the recording medium dried by the drying means;
An image forming apparatus comprising:   The image forming apparatus according to claim 1, wherein the blowing unit blows air adjusted to an atmospheric humidity and an atmospheric temperature outside the apparatus. The conveying means is composed of a plurality of conveying members that sequentially convey the recording medium,
The image forming apparatus according to claim 1, wherein the blowing unit is disposed so as to blow air onto a recording medium conveyed by a conveying member that discharges the recording medium to the outside of the apparatus.   The image forming apparatus according to claim 1, wherein the spraying unit extends in a direction intersecting with a conveyance direction of the recording medium. The spraying means
A water pipe formed with an outlet from which mist is ejected;
A water supply device for supplying water to the water pipe;
A blower that blows air, which is humidified with mist blown from the water pipe outlet, onto the recording medium;
A temperature adjusting member for adjusting the temperature of the air blown by the blower;
An image forming apparatus according to any one of claims 1 to 4. A temperature detection member is provided to detect the ambient temperature outside the device.
The image forming apparatus according to claim 5, further comprising a control unit that controls the temperature adjustment member based on a detection signal from the temperature detection member. Humidity detection member that detects the atmospheric humidity outside the device is provided
The image forming apparatus according to claim 6, wherein the control unit adjusts an amount of water that the water supply device supplies to the water pipe based on a detection signal from the humidity detection member.   The image forming apparatus according to claim 6, wherein the control unit adjusts a driving force of the blower according to a conveyance speed of the recording medium.   The image forming apparatus according to any one of claims 6 to 8, wherein the control unit selectively controls opening and closing of the outlet of the water pipe according to a size of a recording medium.   The image according to any one of claims 1 to 9, wherein a shielding plate is provided between the spraying means and the drying means to prevent air on the drying means side from flowing into the spraying means side. Forming equipment.

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