JP7406180B2 - Heating device, liquid ejection device, image forming device, post-processing device, and conveyance device - Google Patents

Description

The present invention relates to a heating device, a liquid ejecting device, an image forming device, a post-processing device, and a conveyance device.

For example, a drying device that dries liquid on a sheet by heating the sheet is known as a heating device installed in an image forming apparatus such as a copying machine or a printer.

Patent Document 1 (Japanese Unexamined Patent Publication No. 2016-78428) discloses that even if cockling (waving) occurs on the sheet due to adhesion of liquid, the cockling is corrected and the sheet is brought into close contact with the tension roller, so that the sheet can be efficiently rolled. A drying device has been proposed.

By the way, in addition to cockling, there is curling as a deformation of the sheet caused by liquid adhering to the sheet. Generally speaking, there are two types of curl: back curl, which curls so that the surface to which liquid is attached becomes convex, and face curl, which curls in the opposite direction to the back curl. When such curls occur in the sheet, there are problems such as the sheet getting caught during conveyance, resulting in poor conveyance, and the number of sheets that can be stacked decreases. Therefore, there is a need for measures to effectively suppress sheet deformation such as curling.

The present invention is provided with a heating member that heats a surface of a sheet to which a liquid is attached, opposite to the liquid-attached surface, and the heating member is configured to curve the sheet so that the liquid-attached surface becomes concave. The sheet is conveyed in contact with the heating member upstream of the curved portion in the sheet conveyance direction , and the heating member is a belt member that is wound around a plurality of belt support members. , a heating source that heats the belt member; a pressing member that presses the outer peripheral surface of the belt member between the plurality of belt support members to form the curved portion on the belt member; and a pressing member that protrudes in an outer radial direction. The heating device includes a protrusion rotating body having a plurality of protrusions and disposed to face the outer peripheral surface of the belt member on the upstream side of the pressing member in the sheet conveyance direction .

According to the present invention, deformation of the sheet can be effectively suppressed.

1 is a schematic configuration diagram of an image forming apparatus according to an embodiment of the present invention. It is a schematic block diagram of a drying device. FIG. 2 is a plan view of the drying device showing the arrangement of spurs. FIG. 7 is a plan view of the drying device showing another example of the arrangement of spurs. FIG. 3 is a diagram for explaining the principle of backcurling on paper. FIG. 3 is a diagram for explaining the principle of backcurling on paper. It is a figure which shows the example which uses an abrasive roller as a press roller. It is a figure which shows the example which used a knurled roller as a press roller. It is a figure which shows the example which replaced with the spur and provided the ventilation fan. It is a figure which shows the example which replaced with the spur and provided the suction fan. FIG. 3 is a diagram showing an example in which a pressing roller contacts a fixed roller via a heating belt. It is a figure which shows the example which can change the winding angle of the heating belt with respect to a press roller. It is a figure showing the composition of the drying device concerning other embodiments of the present invention. It is a figure showing the composition of the drying device concerning yet another embodiment of the present invention. It is a figure which shows the example in which many fine unevenness|corrugations are provided in the outer peripheral surface of a press belt. It is a figure which shows the example in which the press belt was formed in the mesh shape. FIG. 6 is a diagram showing an example in which a ceramic heater in contact with a heating belt is used as a heating source. It is a figure which shows the example which supported the heating belt by the belt support member which does not rotate. It is a figure which shows the example which uses the press pad which does not rotate as a press member. It is a figure which shows the example which uses the heating guide which does not rotate as a heating member. It is a figure which shows the modification of a heating guide. FIG. 22 is a cross-sectional view of the heating guide shown in FIG. 21 in the paper width direction. FIG. 3 is a diagram showing an example in which a drying device according to the present invention is installed in another image forming apparatus. FIG. 7 is a diagram showing an example in which the drying device according to the present invention is installed in yet another image forming apparatus. 1 is a diagram showing an example in which a drying device according to the present invention is mounted on a conveyance device. 1 is a diagram showing an example in which a drying device according to the present invention is installed in a post-processing device.

Hereinafter, the present invention will be explained based on the accompanying drawings. In each drawing for explaining the present invention, components such as members and components having the same function or shape are given the same reference numerals as much as possible so that they can be easily distinguished. Omitted.

FIG. 1 is a schematic configuration diagram of an image forming apparatus according to an embodiment of the present invention.

As shown in FIG. 1, the image forming apparatus 100 according to the present embodiment includes a document conveying device 1, an image reading device 2, an image forming section 3, a sheet feeding device 4, a cartridge mounting section 5, and a drying device. (heating device) 6 and a sheet discharge section 7. Further, a sheet aligning device 200 is arranged next to the image forming apparatus 100.

The document conveyance device 1 is a device that separates documents one by one from a document tray 11 and conveys them toward the contact glass 13 of the image reading device 2 . The document conveyance device 1 includes a plurality of conveyance rollers and the like as document conveyance means for conveying a document.

The image reading device 2 is a device that reads an image of a document placed on a contact glass 13 or an image of a document passing over the contact glass 13. The image reading device 2 includes an optical scanning unit 12 as an image reading section. The optical scanning unit 12 includes a light source that irradiates light onto the original on the contact glass 13, a CCD (charge coupled device) as an image reading means that reads an image from light reflected from the original, and the like. Furthermore, a contact image sensor (CIS) or the like may be used as the image reading means.

The image forming section 3 has a liquid ejection head 14 as a liquid ejection means for ejecting ink, which is a liquid for image formation. The liquid ejection head 14 may be a so-called serial type that ejects ink while moving in the main scanning direction (sheet width direction), or may be a so-called serial type that ejects ink without moving a plurality of liquid ejection heads arranged in the main scanning direction. It may be a so-called line type.

A plurality of ink cartridges 15Y, 15M, 15C, and 15Bk are removably mounted on the cartridge mounting portion 5. Each ink cartridge 15Y, 15M, 15C, and 15Bk is filled with ink of a different color, such as yellow, magenta, cyan, and black, for example. The ink in each ink cartridge is supplied to the liquid ejection head 14 by a supply pump.

The sheet supply device 4 includes a plurality of paper feed cassettes 16 as sheet storage units. Each paper feed cassette 16 stores paper P, so-called cut paper, which is cut in advance to a predetermined size in the paper transport direction (sheet transport direction), such as A4 size or B4 size, as a sheet on which an image will be formed. There is. Further, each paper feeding cassette 16 is provided with a paper feeding roller 17 as a sheet feeding means and a separation pad 18 as a sheet separating means.

The sheet alignment device 200 is a post-processing device that aligns sheets sent from the image forming apparatus 100. In addition to the sheet aligning device 200, other post-processing devices such as a stapling device for binding sheets and a punching device for punching holes in sheets may be provided.

The operation of the image forming apparatus according to this embodiment will be described with reference to FIG.

When there is an instruction to start a printing operation, paper P is fed from one of the plurality of paper feed cassettes 16 . Specifically, as the paper feed roller 17 rotates, the uppermost sheet P stored in the paper feed cassette 16 is separated from other sheets (sheet bundle) by the paper feed roller 17 and the separation pad 18 and sent out. It will be done.

When the paper P is conveyed to the horizontal transport path 20 facing the image forming section 3 , an image is formed on the paper P by the image forming section 3 . Specifically, the ejection operation of the liquid ejection head 14 is controlled according to the image information of the document read by the image reading device 2 or the print information instructed to print from the terminal, so that the image forming surface (top surface) of the paper P is controlled. ) to form an image. Note that the image formed on the paper P may be a meaningful image such as a character or a figure, or a pattern that has no meaning in itself.

When double-sided printing is performed, the paper P is guided to the reverse transport path 21 by transporting the paper P in the opposite direction on the downstream side of the image forming section 3 in the paper transport direction. Specifically, after the trailing edge of the paper P passes through the first path switching means 31 disposed on the downstream side of the image forming section 3 in the paper transport direction, the paper P is transported in the opposite direction. Further, after the trailing edge of the paper P passes through the first path switching means 31, the first path switching means 31 switches the conveyance path to the reverse conveyance path 21. Thereby, the paper P is guided to the reversing conveyance path 21. Then, as the paper P passes through the reversing conveyance path 21, the paper P is again conveyed to the image forming section 3 in a reversed state, and an image is formed on the back side of the paper P by the operation of the image forming section 3 similar to that described above. is formed.

The paper P on which the image has been formed is switched between the transport path 22 that passes through the drying device 6 or the transport path that does not pass through the drying device 6 by the second path switching device 32 located downstream of the first path switching device 31 in the paper transport direction. Route 23 is selectively guided. When the paper P is guided to the conveyance path 22 passing through the drying device 6, the ink on the paper P is dried by the drying device 6. On the other hand, when the paper P is guided to the conveyance path 23 that does not pass through the drying device 6, the third path switching means 33 directs the paper P to the conveyance path 24 toward the sheet discharge section 7 or toward the sheet alignment device 200. It is selectively guided to the conveyance path 25. Further, the paper P that has passed through the drying device 6 is selectively guided by another fourth path switching means 34 to either the conveyance path 26 toward the sheet discharge section 7 or the conveyance path 27 toward the sheet alignment device 200. Ru.

When the paper P is guided to the conveyance paths 24 and 26 toward the sheet discharge section 7, the paper P is discharged to the sheet discharge section 7 with the liquid-adhering surface facing downward. On the other hand, when the paper P is guided to the conveyance paths 25 and 27 toward the sheet alignment device 200, the paper P is conveyed to the sheet alignment device 200, and the sheets P are aligned and placed. This completes a series of printing operations.

The configuration of the drying device 6 according to this embodiment will be described below.

As shown in FIG. 2, the drying device 6 includes a heating belt 40, a tension roller 41, a fixed roller 42, a pressing roller 43, a heater 44, and a plurality of spurs 45.

The heating belt 40 is a heating member that contacts the paper and heats the paper. The heating belt 40 is composed of a flexible endless belt member, and is rotatably supported by being wound around a tension roller 41 and a fixed roller 42 .

Tension roller 41 and fixed roller 42 are belt support members that rotatably support heating belt 40 . The tension roller 41 is configured to be movable within the heating belt 40, and is pressed against the inner peripheral surface of the heating belt 40 by a biasing means such as a spring. On the other hand, the fixed roller 42 is fixed so as not to move.

The pressing roller 43 is a pressing member that presses the outer peripheral surface of the heating belt 40 between the tension roller 41 and the fixed roller 42. The pressure roller 43 is pushed into the inside of the heating belt 40 (inside the common tangent line M that contacts the respective outer peripheral surfaces of the tension roller 41 and the fixed roller 42) by a pressing means such as a spring or a cam, so that the heating belt 40 is A curved portion 40a is formed along the outer peripheral surface of the pressure roller 43.

The heater 44 is a heat source that heats the heating belt 40. In this embodiment, the heater 44 is arranged inside the tension roller 41. Therefore, when the heater 44 generates heat, the heat is transmitted to the heating belt 40 via the tension roller 41, and the heating belt 40 is heated. Therefore, the tension roller 41 in this embodiment functions as a heating member (heating rotating body) that heats the heating belt 40 with the heat of the heater 44 disposed inside. As the heating source, in addition to a radiant heater that emits infrared rays such as a halogen heater or a carbon heater, an electromagnetic induction heating source, a hot air generator, or the like can be used. Further, the heater may be either a contact type or a non-contact type. In this embodiment, a halogen heater is used as the heater 44.

The spur 45 is a protrusion rotating body having a plurality of protrusions that protrude in the outer diameter direction. The spur 45 is arranged so as to be in contact with the outer circumferential surface of the heating belt 40 on the upstream side of the press roller 43 in the paper conveyance direction A. Further, as shown in FIG. 3, a plurality of spurs 45 are provided on a rotating shaft 46 extending in the belt width direction or paper width direction (sheet width direction) shown by arrow B in the figure. Here, the term "belt width direction" or "sheet width direction" refers to a direction that intersects the paper transport direction A along the paper transport path. The plurality of spurs 45 may be arranged at equal intervals across the axial direction of the rotating shaft 46 (belt width direction or sheet width direction), as in the example shown in FIG. 3, or may be arranged at different intervals. You can. Further, as in the example shown in FIG. 4, spur groups in which a plurality of spurs 45 are arranged close to each other may be arranged at equal or different intervals in the axial direction of the rotating shaft 46. Further, the upstream spur 45 and the downstream spur 45 in the paper transport direction A may not be at the same position in the paper transport direction A, but may be shifted from each other in the axial direction of the rotation shaft 46 .

Next, the operation of the drying device 6 will be explained.

When the printing operation is started, the fixed roller 42 is driven to rotate in the direction of the arrow in FIG. 2 (counterclockwise), thereby causing the heating belt 40, the tension roller 41, the pressure roller 43, and the spur 45 to rotate. Note that the tension roller 41 and the pressure roller 43 may function as drive rollers. Further, as the heater 44 generates heat, the heating belt 40 is heated via the tension roller 41. The heat generation of the heater 44 is controlled so that the temperature of the heating belt 40 is maintained within a range of, for example, 100 to 150 degrees.

In this state, as shown in FIG. 2, when the paper P to which the liquid ink I is attached is conveyed to the drying device 6, the paper P enters between the spur 45 and the heating belt 40, and the rotating heating Paper P is conveyed by belt 40. At this time, since the surface Pb of the paper P opposite to the liquid adhering surface Pa (the surface to which the ink I adheres) is in contact with the heating belt 40, heat is transferred from the heating belt 40 to the paper P, and the paper P is heated. As a result, the drying of the ink I on the paper P progresses.

Thereafter, the paper P enters between the pressure roller 43 and the heating belt 40. While the paper P passes through the pressure roller 43, the paper P is further heated, thereby further promoting the drying of the ink I on the paper P. Then, the paper P is discharged from the drying device 6. Further, at this time, the pressing roller 43 also has a function of changing the conveyance direction of the paper P to a discharge direction different from the entrance direction.

Incidentally, in a liquid ejection type image forming apparatus that forms an image by ejecting liquid such as ink onto paper, the paper may curl due to the liquid adhering to the paper.

Generally, in the case of plain paper, when a liquid L adheres to one surface Pa of the paper P shown in FIG. Stretching causes curls. More specifically, the moisture W penetrates between the cellulose fibers of the paper P and breaks the hydrogen bonds between the cellulose fibers, thereby widening the intervals between the cellulose fibers and causing the paper P to stretch in a specific direction. As a result, so-called back curl occurs in which the liquid adhesion surface Pa (image forming surface) of the paper P becomes convex.

Furthermore, in electrophotographic image forming apparatuses that form images using toner, in order to fix the toner on the paper, the surface on which the toner is attached to the paper is heated to a higher temperature than the surface on the opposite side. This may cause curls similar to back curls. That is, as shown in FIG. 6, when the toner adhesion surface Pa of the paper P to which the toner T adheres is heated at a high temperature, the moisture content of the water W originally contained in the paper P becomes opposite to that on the toner adhesion surface Pa side. is higher on the surface Pb side, so that shrinkage of the paper P due to subsequent drying becomes more noticeable on the surface Pb opposite to the toner adhesion surface Pa. This causes a back curl in which the toner adhesion surface Pa (image forming surface) becomes convex.

When such backcurls occur on the paper, problems such as the paper getting caught during conveyance, resulting in poor conveyance, and a reduction in the number of ejected sheets that can be stacked, occur. Therefore, in the embodiments of the present invention, measures are taken to effectively suppress paper deformation such as back curl.

Hereinafter, a configuration for effectively suppressing deformation of paper in an embodiment of the present invention will be described in detail.

In the drying device 6 according to the above-described embodiment, as shown in FIG. The paper P is heated by contact with the paper P. That is, contrary to the example shown in FIG. 6 where back curl occurs, the paper P is heated from the side opposite to the image forming side. As a result, the surface Pb of the paper P opposite to the liquid adhesion surface Pa is heated to a higher temperature, so that a force in the opposite direction to the force that causes back curl acts on the paper P. In this way, in the drying device 6 according to the present embodiment, the paper P is heated from the side Pb opposite to the liquid adhesion surface Pa, thereby generating a force in the opposite direction to the force that causes back curl. This makes it possible to suppress the subsequent occurrence of back curls.

Further, in the drying device 6 according to the present embodiment, when the paper P passes the pressure roller 43, the liquid adhesion surface Pa of the paper P passes along the curved portion 40a of the heating belt 40 in the paper conveyance direction A. It is transported while being bent into a concave shape. That is, the paper P is conveyed while being bent in the opposite direction to the bending direction of the back curl. As a result, the paper P becomes difficult to bend in the direction of backcurling, and subsequent occurrence of backcurling is suppressed.

Furthermore, in the drying device 6 according to the present embodiment, when the paper P passes the pressure roller 43, the paper P is pressed against the heating belt 40 by the cylindrical outer circumferential surface of the pressure roller 43. The degree of adhesion (contact area) of the paper P increases. Thereby, heat is effectively transferred from the heating belt 40 to the paper P, and drying of the ink on the paper P is further promoted. As a result, the occurrence of back curl can be suppressed compared to the conventional method.

Furthermore, when double-sided printing is performed, it is desirable to dry the images on the front side and the images on the back side separately. That is, after the image on the front surface is dried by the drying device 6 as described above, the paper P is switched back and passed through the conveyance path 25 and the conveyance path 23, and then through the reversal conveyance path 21. Guide to the image forming section 3. In addition, the paper P is transferred to the upstream side of the transport path 22 in the paper transport direction (upstream of the dryer 6) without passing through the transport path 25 and the transport path 23, and via another transport path that bypasses the drying device 6. The paper P may be transported and guided to the image forming section 3 via the reversing transport path 21. After an image is formed on the back side of the paper P by the image forming section 3, the paper P is again conveyed to the drying device 6, and the image on the back side is dried.

When drying the image on the back side, the paper P is heated by the surface opposite to the back side, that is, the front side, coming into contact with the heating belt 40 . Therefore, the paper P is heated from the surface Pb (front surface) opposite to the liquid adhesion surface Pa (back surface) to which the ink before drying adheres, and in the opposite direction to the force that causes back curl on the paper P. The force of is applied. Further, as the paper P enters between the pressure roller 43 and the heating belt 40, the paper P is bent along the pressure roller 43, and a bending correction force is applied in the opposite direction to the force that causes back curl on the paper P. will be granted. In this manner, even when drying the image on the back side, paper deformation such as back curling is effectively suppressed by the heating by the heating belt 40 and the bending correction force of the pressing roller 43.

Note that during double-sided printing, since ink adheres to both sides of the paper, both sides can also be said to be "liquid adhesion surfaces." However, in the present invention, when double-sided printing is performed and the ink on the back side of the paper P is dried, the back side to which the ink adheres before drying processing is referred to as a "liquid adhesion surface." Therefore, in this specification, the "liquid adhesion surface" means the surface (surface) to which the liquid is adhered when the liquid is adhered to only one side of the sheet; In the case of "state", it means the surface (back surface) to which the liquid was attached for the second time.

As described above, in the drying device 6 according to the present embodiment, the paper P is heated from the surface Pb opposite to the liquid adhering surface Pa, and furthermore, the paper P is subjected to a bending action at the curved portion 40a. , back curl is effectively suppressed. Therefore, according to the drying device 6 according to the present embodiment, problems such as paper conveyance failure due to back curling and a decrease in the number of stacked sheets are less likely to occur as compared to the conventional drying device.

Further, according to the drying device 6 according to the present embodiment, it is possible to suppress not only back curl but also cockling (waving) of the paper. Even if the sheet P with cockling is conveyed to the drying device 6 according to the present embodiment, the liquid adhesion surface Pa of the sheet P and this The surface Pb on the opposite side is corrected to the same length, and cockling of the paper P is suppressed. In this way, the drying device 6 according to the present embodiment can effectively suppress deformation of the paper including cockling as well as back curling.

Further, in the drying device 6 according to the present embodiment, since the paper P is ejected after being heated, it is possible to reduce the ink on the paper P from adhering to the conveyance roller or other paper afterwards. . On the other hand, immediately after the paper P is conveyed to the drying device 6, the ink is likely to be in a liquid state, so there is a possibility that the ink may adhere to peripheral members. However, in the drying device 6 according to the present embodiment, before the paper P reaches the pressure roller 43 (upstream of the pressure roller 43 in the paper conveyance direction A), the paper P is moved onto the heating belt 40 by the plurality of spurs 45. Since the ink (image) on the paper P is guided to be in contact with the paper P, the paper P can be heated while reducing disturbance of the ink (image) on the paper P. That is, even if the spur 45 comes into contact with the liquid adhesion surface Pa of the paper P, the contact area of the spur 45 with the liquid adhesion surface Pa is small, so it is possible to suppress the ink on the paper P from being disturbed by the contact of the spur 45. Furthermore, since ink adhesion to the spur 45 can be suppressed, it is also possible to reduce staining of the paper due to subsequent ink adhesion from the spur 45 to another paper.

In this way, in the drying device 6 according to the present embodiment, the paper P can be brought into contact with the heating belt 40 on the upstream side of the paper conveyance direction A than the pressure roller 43 by the guidance of the spur 45, so that the paper P The ink on the paper P can be dried to some extent (for example, to the extent that the ink does not adhere to other members) before reaching the pressure roller 43. As a result, even when the pressure roller 43 having a cylindrical outer peripheral surface is used to increase the degree of adhesion of the paper P to the heating belt 40 as in the present embodiment, ink adhesion to the pressure roller 43 can be suppressed, and the pressure Deterioration in image quality due to ink adhering to the roller 43 and staining of the paper due to ink adhering from the pressure roller 43 to another paper can be reduced.

In addition, in the drying device 6 according to the present embodiment, the heater 44 is arranged upstream of the pressure roller 43 (or the curved portion 40a where the pressure roller 43 contacts the heating belt 40) in the paper conveyance direction A. Therefore, the paper P can be effectively heated upstream of the pressure roller 43 in the paper transport direction A. Thereby, drying of the ink is promoted before the paper P reaches the pressure roller 43, and adhesion of ink to the pressure roller 43 can be more effectively suppressed.

Furthermore, in order to further suppress the adhesion of ink to the pressure roller 43, a roller may be used whose outer peripheral surface is provided with irregularities so as to reduce the contact area between the pressure roller 43 and the paper. For example, as shown in FIG. 7, there is an abrasive roller with a large number of abrasive grains 55 made of ceramic or glass bonded to its outer circumferential surface, or as shown in FIG. A knurled roller can be used.

Further, according to the drying device 6 according to the present embodiment, since the paper P can be transported while the paper P is brought into contact with the surface of the heating belt 40 by the spur 45, waviness of the paper P can be reduced and the pressure roller 43 and the heating belt 40, the paper P can enter between the two. This makes it possible to reduce the occurrence of wrinkles when the paper P is held between the pressure roller 43 and the heating belt 40.

Furthermore, in the drying device 6 according to the present embodiment, the paper P is not strongly pressed on the heating belt 40 before the paper P reaches the pressure roller 43, so that the occurrence of wrinkles on the paper P is prevented. It can be reduced more effectively. That is, in the present embodiment, the pressure roller 43 and the tension roller 4 are in contact with the heating belt 40 at locations separated from each other in the paper conveyance direction A, and the paper P is strongly pushed by the pressure roller 43 and the tension roller 41. A nip portion to be pressurized is not formed. Further, the spur 45 disposed upstream of the pressure roller 43 in the paper conveyance direction A is disposed so as to simply contact the heating belt 40 without applying pressure. is not pressurized. In this way, in this embodiment, the paper P is not strongly pressed by the pressure roller 43 and the tension roller 41, and the paper P is conveyed while being held flat on the heating belt 40 by the spur 45. Therefore, the paper P can be allowed to enter between the pressure roller 43 and the heating belt 40 in a plane, and the occurrence of wrinkles on the paper P can be suppressed.

Note that the spur 45 does not necessarily need to be in contact with the outer peripheral surface of the heating belt 40. If the paper P can be conveyed on the heating belt 40 while keeping it flat without waving, the spur 45 is arranged close to the outer peripheral surface of the heating belt 40 (without contacting it through a gap). You can leave it there. In short, as long as good paper conveyance can be ensured, the spur 45 may be in contact with or not in contact with the heating belt 40, and may be disposed facing the outer peripheral surface of the heating belt 40. .

Further, as in the example shown in FIG. 9, instead of the spur 45, a blowing fan 61 may be used as a blowing means. In this case, the paper P is brought into contact with the heating belt 40 by the air discharged from the blower fan 61, so that the paper P can be conveyed while being kept flat without being strongly pressurized. Further, in order to suppress the heating belt 40 from cooling down, the blower fan 61 may be a warm air fan.

Alternatively, the heating belt 40 may be charged without using the spur 45, and the paper P may be electrostatically attracted to the charged heating belt 40.

As yet another example, as shown in FIG. 10, a suction fan 62 may be disposed inside the heating belt 40. In this case, the paper P is attracted to the heating belt 40 by the suction fan 62 sucking air from a large number of ventilation holes provided in the heating belt 40 . In this case as well, the paper P can be conveyed while being kept flat without being strongly pressurized.

In this way, in the drying device 6 according to the present embodiment, the paper P is not strongly pressed on the heating belt 40 before the paper P reaches the pressure roller 43, so that the paper is not strongly pressed. It is possible to suppress the occurrence of wrinkles caused by In particular, when the paper P is wet with ink, wrinkles are likely to occur when the paper P is strongly pressurized. It is important that the pressure is not too strong. Therefore, for example, it is more preferable that a nip portion, where the tension roller 41 and the roller opposing the tension roller 41 come into contact (pressure contact) with each other via the heating belt 40, is not formed.

On the other hand, the pressing roller 43 does not need to be in contact (press contact) with the fixed roller 42 via the heating belt 40 (FIGS. 2, 9, and 10), or may be in contact with the fixed roller 42 (FIG. 11).

In particular, in the case of the examples shown in FIGS. 2, 9, and 10, the pressure roller 43 contacts the heating belt 40 at a location away from both the tension roller 41 and the fixed roller 42 in the paper conveyance direction A. Since the paper P is arranged in the same direction, wrinkles are even less likely to occur on the paper P.

In addition, as shown in FIGS. 2, 9, and 10, if the pressure roller 43 is arranged so as not to contact (pressure) the tension roller 41 or the fixed roller 42 via the heating belt 40, the roller The load on the heating belt 40 due to the pressure applied by the heating belt 40 can also be reduced. As a result, damage and wear of the heating belt 40 can be suppressed, thereby improving the durability and extending the life of the heating belt 40. Furthermore, since the rotational resistance of the heating belt 40 can be reduced, the rotational efficiency is increased and driving energy can be saved.

Further, as in the example shown in FIG. 12, the wrapping angle θ of the heating belt 40 around the pressing roller 43 may be changed by moving the pressing roller 43. Thereby, it is possible to change the length H of the contact range (curved portion 40a) in the paper conveyance direction A where the pressure roller 43 and the heating belt 40 are in contact with each other.

Specifically, when an image with a low printing rate such as characters is formed, the amount of ink adhering to the paper P is relatively small, and back curl is less likely to occur. Therefore, when an image with a low printing rate is formed, as shown in FIG. 12, the pressure roller 43 is moved to the right in the figure to reduce the wrapping angle θ of the heating belt 40 with respect to the pressure roller 43. The length H of the contact range may be shortened. In this case, the bending correction effect when the paper P passes through the curved portion 40a of the heating belt 40 can be reduced, and a correction force corresponding to the amount of back curl that may occur can be applied. Furthermore, in this case, since the length H of the contact range between the pressure roller 43 and the heating belt 40 is shortened, the time during which the paper P is heated while being pressed against the heating belt 40 by the pressure roller 43 is shortened. However, since the paper P with a low printing rate and a small amount of ink adhesion requires a short heating time for drying, the winding angle θ may be made small. Furthermore, in this case, the amount of heat applied to the paper P from the heating belt 40 is also reduced, so energy saving is improved.

On the other hand, if an image with a high printing rate and a large amount of ink adhesion is to be formed, the pressure roller 43 is moved to the left side in the figure to increase the wrapping angle θ of the heating belt 40 with respect to the pressure roller 43, thereby increasing the contact range. Just make the length H longer. This increases the bending correction effect when the paper P passes through the curved portion 40a of the heating belt 40, and it becomes possible to effectively suppress paper deformation such as back curl.

Further, when relatively thick paper P such as cardboard is transported, it is preferable to reduce the winding angle θ because if the winding angle θ is large, the paper P will curve and become difficult to transport. By reducing the winding angle θ, even when thick paper P is transported, it becomes easier to transport the paper P smoothly, and occurrence of transport defects can be avoided. In this way, by appropriately changing the wrapping angle θ according to the thickness of the paper and the amount of ink attached to the paper as described above, deformation of the paper can be effectively suppressed while further improving transportability and energy saving performance. You will be able to do so.

Further, in order to improve energy saving, the amount of heat generated by the heater 44 may be controlled depending on the amount of ink attached to the paper P. That is, when the amount of ink adhering to the paper P is small, the heating time required for drying is shortened, so the amount of heat generated by the heater 44 is reduced compared to when the amount of ink adhering to the paper P is large, thereby saving energy. can improve sex.

Further, as shown in FIG. 12, the moving direction of the pressure roller 43 may be parallel to the direction of the heating belt 40 extending downstream from the pressure roller 43 in the paper conveyance direction A (direction of arrow C in the figure). desirable. By doing this, even if the pressing roller 43 moves, there is no need to change the direction in which the paper P is discharged from the drying device 6, so that the paper P can be stably discharged.

Furthermore, as shown in FIG. 12, when the pressure roller 43 moves, the tension roller 41 also moves at the same time, so that the tension applied to the heating belt 40 can be adjusted to a predetermined value. At this time, by moving the tension roller 41 in the diagonally downward left direction in FIG. 12 (direction of arrow D in the figure) and in the opposite direction, the spur 45 at the most upstream position in the paper conveyance direction A is moved. Even without this, the contact state between the spur 45 and the heating belt 40 can be maintained. As a result, the entry position or entry angle at which the paper P enters between the most upstream spur 45 and the heating belt 40 in the paper transport direction A does not change, so the paper P can be stably entered.

FIG. 13 is a diagram showing the configuration of a drying device 6 according to another embodiment of the present invention.

In the drying device 6 shown in FIG. 13, a heater 47, which is a heat source different from the heater 44 arranged inside the tension roller 41, is arranged inside the pressure roller 43. Other than that, the configuration is basically the same as that shown in FIG.

In this case, the pressing roller 43 functions both as a pressing member that presses the paper P and as a heating member (heating rotating body) that heats the paper P. Therefore, when the paper P passes through the pressure roller 43, both the front and back surfaces of the surface that contacts the heating belt 40 (the surface Pb opposite to the liquid adhesion surface Pa) and the surface that contacts the pressure roller 43 (the liquid adhesion surface Pa) are heated at the same time. Thereby, the paper P can be heated more effectively, and the drying of the ink on the paper P can be further accelerated.

Furthermore, in this case, heat is applied to the surface that contacts the heating belt 40 (the surface Pb opposite to the liquid adhesion surface Pa) for a longer time than the surface that contacts the pressure roller 43 (the liquid adhesion surface Pa). As a result, the surface Pb of the paper P opposite to the liquid adhesion surface Pa is heated at a higher temperature than the liquid adhesion surface Pa, as in the above-described embodiment. Therefore, in this embodiment as well, a force in the opposite direction to the force that causes backcurl acts on the paper P, so that backcurl can be suppressed. Further, in order to suppress back curl more effectively, the heat generation of each heater 44 and 47 may be controlled so that the temperature of the heating belt 40 is higher than the temperature of the pressure roller 43.

When double-sided printing is performed, the drying device 6 dries the ink on the front side of the paper P, forms an image on the back side, and transports the paper P to the drying device 6 again to print the back side. All you have to do is dry the ink. Alternatively, after images are formed on both the front and back sides of the paper P, the paper P may be conveyed to the drying device 6 and the ink on both the front and back sides may be dried at the same time.

Further, even in such a structure in which the heater 47 is arranged inside the pressure roller 43, the pressure roller 43 is configured to be movable, as in the example shown in FIG. It may be possible to change the angle θ and the length H of the contact range (curved portion 40a) in the paper conveyance direction A where the pressure roller 43 and the heating belt 40 contact. Further, depending on the amount of ink adhering to the paper P, the amount of heat generated by one or both of the heater 44 in the tension roller 41 and the heater 47 in the pressure roller 43 may be controlled.

FIG. 14 is a diagram showing the configuration of a drying device 6 according to yet another embodiment of the present invention.

In the drying device 6 shown in FIG. 14, a pressure belt 48 made of an endless belt member is wrapped around the pressure roller 43. In addition to the pressure roller 43, a support roller 49 is provided as a belt support member that rotatably supports the pressure belt 48. Other than that, the configuration is basically the same as that shown in FIG.

In the drying device 6 according to this embodiment, the press roller 43 is urged toward the heating belt 40 via the press belt 48, so that the press belt 48 is pressed against the heating belt 40. That is, in this embodiment, the pressing roller 43 and the pressing belt 48 function as a pressing member that presses the heating belt 40. Furthermore, in this embodiment, when the fixed roller 42 is driven to rotate, the heating belt 40, tension roller 41, pressure belt 48, pressure roller 43, and support roller 49 are driven to rotate accordingly. Further, either one of the pressure roller 43 and the support roller 49 may be a driving roller.

In the drying device 6 according to this embodiment, when the paper P passes through the spur 45 and enters between the heating belt 40 and the pressure belt 48, the paper P is pressed by the rotating heating belt 40 and the pressure belt 48. It is transported while being At this time, the paper P is bent along the curved portion 40a of the heating belt 40 in a direction opposite to the bending direction of the backcurl, thereby effectively suppressing the occurrence of backcurl. In addition, in the drying device 6 according to the present embodiment, two belt members (heating belt 40 and pressure belt 48) that are in contact with each other are used as members that transport the paper P while sandwiching it. It is possible to secure a large conveyance range (the range indicated by the symbol H in FIG. 14) in the paper conveyance direction A. Thereby, the paper P can be heated more effectively. Therefore, according to the drying device 6 according to the present embodiment, the drying of the ink on the paper P is further promoted, and deformation such as back curl can be more effectively suppressed.

Furthermore, in the drying device 6 according to the present embodiment, the pressure belt 48 is disposed so as to extend downstream in the paper transport direction A rather than upstream of the curved portion 40a in the paper transport direction A. , adhesion of ink to the pressure belt 48 can be suppressed. That is, since the paper P can be heated while being guided by the spur 45 on the upstream side of the curved portion 40a in the paper conveyance direction A, even if the paper P subsequently contacts the pressure belt 48, the pressure is not applied. Adhesion of ink to the belt 48 can be suppressed.

In addition, in order to more effectively suppress the adhesion of ink to the pressure belt 48, the pressure belt 48 may be a belt 57 having a large number of fine irregularities on its outer peripheral surface as shown in FIG. 15, or an example shown in FIG. A belt 58 formed in a mesh shape may also be used.

Also, in the drying device 6 shown in FIG. 14, the pressure roller 43 may be configured to be movable according to the amount of ink adhering to the paper P, as in the example shown in FIG. With this configuration, by changing the winding angle θ of the heating belt 40 with respect to the pressing belt 48, the length H of the contact range in the paper conveyance direction A where the pressing belt 48 and the heating belt 40 are in contact can be changed. I can do it. Further, the amount of heat generated by the heater 47 may be controllable depending on the amount of ink adhering to the paper P. Furthermore, a heater may be disposed within the pressure roller 43 so that the paper P can be heated from both the front and back sides.

Furthermore, the drying device (heating device) according to the present invention is not limited to the above-described embodiments and modifications.

For example, the heat source that heats the heating belt 40 is not limited to being disposed inside a roller (tension roller 41 or fixed roller 42) that stretches the heating belt 40; (for example, the ceramic heater 50). Furthermore, a ceramic heater may be placed in contact with the pressure belt 48 shown in FIG. 14 as well. Moreover, the ceramic heater 50 may be arranged so as to contact the outer circumferential surface of a belt member, in addition to the case where it contacts the inner circumferential surface of a belt member such as the heating belt 40 or the pressure belt 48. However, since the ceramic heater 50 slides relative to the rotating belt member, in order to reduce the sliding resistance at this time, a sliding member made of a low-friction material is installed between the ceramic heater 50 and the belt member. It is preferable to interpose a sheet or a sheet metal member such as aluminum coated with a sliding coating to improve heat conduction efficiency.

Furthermore, in the drying device (heating device) according to the present invention, the belt support member that supports the heating belt 40 is not limited to rotating bodies such as the tension roller 41 and the fixed roller 42. For example, the heating belt 40 may be supported by a plurality of belt support members 64 and 65 that do not rotate, as shown in FIG. In this case, as the pressing roller 43 is rotationally driven, the heating belt 40 is driven to rotate while sliding on each of the belt support members 64 and 65, so that the sliding resistance of the heating belt 40 at this time is reduced. It is preferable that each belt support member 64, 65 is made of a low-friction material. Alternatively, a sliding sheet made of a low-friction material may be interposed between the heating belt 40 and each belt support member 64, 65. Further, each of the belt support members 64 and 65 may be configured separately or may be configured integrally via a pair of frame members 66 shown in FIG. 18.

Furthermore, in the drying device (heating device) according to the present invention, the pressing member that presses the heating belt 40 is not limited to a rotating body such as the pressing roller 43. For example, if the liquid attached to the paper is a processing liquid that does not form an image, the problem of image distortion does not occur even if the pressing member does not rotate following the paper. Therefore, in such a case, as in the example shown in FIG. 19, the pressing member may be a non-rotating pressing pad 67 made of a curved ceramic heater or the like. In this case, in order to reduce the sliding resistance generated between the heating belt 40 and the pressing pad 67, it is preferable to interpose a sliding sheet made of a low-friction material between them.

Further, in the drying device (heating device) according to the present invention, the heating member that heats the paper P is not limited to a rotating body such as the heating belt 40. For example, as in the example shown in FIG. 20, the heating member may be a heating guide 70 that does not rotate. The heating guide 70 has a curved portion 70a that curves the paper P. In this case, by rotationally driving the pressure roller 43, the surface Pb of the sheet P opposite to the liquid adhering surface Pa is conveyed while being in contact with the heating guide 70. Further, the paper P passes through the curved portion 70a while being curved so that the liquid adhesion surface Pa becomes concave. As a result, the surface Pb of the paper P opposite to the liquid adhesion surface Pa is heated to a high temperature, and the paper P is bent in the opposite direction to the bending direction of the back curl. Deformations such as curls can be effectively suppressed.

Further, the embodiment is not limited to the embodiment shown in FIG. 20, but may be implemented as shown in FIG. The example shown in FIG. 21 is different from the example shown in FIG. 20 in that the pressing roller 43 is not provided on the curved portion 70a of the heating guide 70, and spurs 45 are provided on the upstream and downstream sides of the heating guide 70 in the paper conveyance direction A. different. As shown in FIG. 22, which is a cross-sectional view of the heating guide 70 in the paper width direction (the sheet width direction that intersects the paper transport direction A along the transport path), the heating guide 70 extends over the entire width of the paper P. The main guide portion 70b is arranged at the opposite end of the sheet P, and a pair of end guide portions 70c are arranged at both ends in the width direction of the paper P. The main guide portion 70b is arranged on the surface Pb side of the paper P opposite to the liquid adhesion surface Pa. On the other hand, each end guide section 70c is arranged to face the widthwise end of the paper P and the liquid adhesion surface Pa on the end side. Each spur 45 is arranged between a pair of end guide portions 70c.

In this example, when the paper P is conveyed to the heating guide 70, both ends of the paper P in the width direction enter between the main guide part 70b and each end guide part 70c, and these guide parts 70b, 70c The paper P is guided by. Further, the paper P is conveyed while being sandwiched between the spur 45 on the upstream side in the paper conveyance direction A and the main guide portion 70b. Then, the paper P passes through the curved portion 70a of the heating guide 70, and then the paper P is conveyed while being sandwiched between the spur 45 on the downstream side in the paper conveyance direction A and the main guide portion 70b, and is ejected. In this case as well, the paper P is heated from the surface Pb opposite to the liquid adhesion surface Pa, and the liquid adhesion surface Pa is curved so as to be concave, thereby effectively suppressing deformation such as back curl. be done.

Furthermore, the drying device (heating device) according to the present invention is applicable not only to the image forming device having the configuration shown in FIG. 1 but also to the image forming device having the configuration shown in FIGS. 23 and 24, for example. be.

The configuration of each image forming apparatus shown in FIGS. 23 and 24 will be described below. In the following description, parts that are different from the above-described embodiment will be mainly explained, and since other parts are the same as the above-described embodiment, the explanation may be omitted.

An image forming apparatus 100 shown in FIG. 23 includes a document conveying device 1, an image reading device 2, an image forming section 3, a sheet feeding device 4, a cartridge mounting section 5, and a drying device similar to the embodiment described above. In addition to a (heating device) 6 and a sheet discharge section 7, a manual sheet feeding device 8 is further provided. Unlike the embodiment shown in FIG. 1, the image forming section 3 is disposed so as to face a conveyance path 80 along which the paper P is conveyed diagonally with respect to the horizontal direction.

The manual sheet supply device 8 includes a manual tray 51 as a loading section on which sheets are placed, and a paper feed roller 52 as a feeding unit that feeds the sheets from the manual tray 51. The manual tray 51 is attached to the main body of the image forming apparatus so as to be openable and closable (swivelable). With the manual feed tray 51 in an open state (the state shown in FIG. Z1), sheets can be placed on the manual feed tray 51 and fed.

In the image forming apparatus 100 shown in FIG. 23, when there is an instruction to start a printing operation, a sheet P is supplied from the sheet supply device 4 or the manual sheet supply device 8, and the sheet P is conveyed to the image forming section 3. Then, when the paper P is conveyed to the image forming section 3, ink is ejected from the liquid ejection head 14 onto the paper P to form an image.

When performing double-sided printing, after the paper P passes through the image forming section 3, the paper P is conveyed in the opposite direction, and the paper P is guided to the reverse conveyance path 81 by the first path switching means 71. By passing through the reversing conveyance path 81, the sheet P is conveyed again to the image forming section 3 in a reversed state, and an image is formed on the back side of the sheet P.

The paper P on which an image has been formed on one or both sides is conveyed to a drying device 6, where the ink on the paper P is dried. Note that when forming an image on the back side of the paper P after drying the ink on the front side, after drying the ink on the front side, the paper P is transferred to the drying device 6 via a conveyance path that bypasses the drying device 6. It is sufficient to switch back to the upstream side in the paper transport direction and guide the paper P to the image forming section 3 again via the reversing transport path 81. The paper P that has passed through the drying device 6 is selectively guided by the second path switching means 72 to either a conveyance path 82 toward the upper sheet discharge section 7 or a conveyance path 83 toward the lower sheet discharge section 7. . When the paper P is guided to the conveyance path 82 toward the upper sheet discharge section 7, the paper P is discharged to the upper sheet discharge section 7. On the other hand, when the paper P is guided to the conveyance path 83 heading toward the lower sheet discharge section 7, the third path switching means 73 selects the conveyance path 84 toward the lower sheet discharge section 7 or the sheet alignment It is selectively guided to the transport path 85 towards the device 200.

Then, when the paper P is guided to the conveyance path 84 toward the lower sheet ejection section 7, the paper P is ejected to the lower sheet ejection section 7. On the other hand, when the paper P is guided to the conveyance path 85 toward the sheet alignment device 200, the paper P is conveyed to the sheet alignment device 200, and the sheets P are aligned and placed.

Subsequently, the image forming apparatus 100 shown in FIG. 24 includes a document conveying device 1, an image reading device 2, an image forming section 3, a sheet feeding device 4, and a cartridge, similar to the image forming apparatus 100 shown in FIG. It includes a mounting section 5, a drying device (heating device) 6, a sheet discharge section 7, and a manual sheet feeding device 8. Note that in this case, the image forming section 3 is arranged so as to face the conveyance path 86 along which the paper P is conveyed in the horizontal direction, similarly to the embodiment shown in FIG.

In the image forming apparatus 100 shown in FIG. 24, when there is an instruction to start a printing operation, a sheet P is supplied from the sheet supply device 4 or the manual sheet supply device 8, and the sheet P is conveyed to the image forming section 3. Then, when the paper P is conveyed to the image forming section 3, ink is ejected onto the paper P from the liquid ejection head 14 to form an image.

When performing double-sided printing, after the paper P passes through the image forming section 3, the paper P is conveyed in the opposite direction, and the paper P is guided to the reverse conveyance path 87 by the first path switching means 74. By passing through the reversing conveyance path 87, the sheet P is conveyed again to the image forming section 3 in a reversed state, and an image is formed on the back side of the sheet P.

The sheet P, on which an image is formed on one or both sides, is selectively guided by the second path switching means 75 to a conveyance path 88 toward the drying device 6 or a conveyance path 89 toward the sheet alignment device 200. When the paper P is guided to the conveyance path 88 toward the drying device 6, the ink on the paper P is dried by the drying device 6. Note that when forming an image on the back side of the paper P after drying the ink on the front side, after drying the ink on the front side, the paper P is transferred to the conveyance path 88 via a conveyance path that bypasses the drying device 6. The paper P may be switched back to the upstream side in the paper transport direction (upstream of the drying device 6), and the paper P may be guided to the image forming section 3 again via the reversing transport path 87. The paper P that has passed through the drying device 6 is discharged to the sheet discharge section 7. On the other hand, when the paper P is guided to the conveyance path 89 toward the sheet alignment device 200, the paper P is conveyed to the sheet alignment device 200, and the sheets P are aligned and placed.

By applying the drying device (heating device) according to the present invention as the drying device 6 installed in the image forming apparatus 100 as shown in FIGS. 23 and 24, the same effects as described above can be obtained. That is, the paper P is heated from the surface Pb opposite to the liquid adhesion surface Pa, and the bending action of the curved portion 40a is applied to the paper P, thereby effectively suppressing back curl. Furthermore, since the ink on the paper P can be effectively dried before the paper P reaches the pressure roller 43, the occurrence of wrinkles on the paper P can also be suppressed.

In addition, in the drying device (heating device) according to the present invention, since the paper is conveyed through the curved part between the pressing member (pressing roller) and the belt member (heating belt), it has a strong stiffness (rigidity). Even if the paper is (high), it is possible to easily bend the paper and change the paper conveyance direction. In particular, such a configuration is effective for a configuration in which paper is conveyed from the vertical direction to the horizontal direction, as shown in FIGS. 1, 23, and 24. Therefore, by arranging the drying device 6 according to this embodiment near the discharge port through which paper is discharged from the image forming apparatus, it is possible to stably discharge the paper.

Further, the drying device (heating device) according to the present invention can be applied not only to an image forming device but also to a liquid ejecting device that ejects a liquid that does not form an image. That is, the liquid ejection apparatus to which the drying apparatus (heating apparatus) according to the present invention is applied includes inkjet image forming apparatuses that eject ink to form images on paper, as well as inkjet image forming apparatuses that eject ink to form images on paper, as well as liquid ejection apparatuses that eject ink to form images on paper. It also includes a processing liquid ejecting device that ejects a processing liquid onto the surface of paper for the purpose.

Further, the drying device (heating device) according to the present invention can also be applied to a conveyance device 300 shown in FIG. 25 that is configured to be detachable from the image forming apparatus 100. The conveyance device 300 includes conveyance paths 82 to 85 for conveying sheets, a drying device 6 for heating the sheets, and a sheet discharge section 7 for discharging the sheets, and is located between the image reading device 2 and the image forming section 3. It is removably mounted on the. Further, the conveying device 300 is configured to be able to convey the sheet to a post-processing section (for example, the sheet aligning device 200) that processes the sheet that has passed through the drying device 6. By applying the drying device (heating device) according to the present invention to such a removable conveying device 300, even if deformation such as curling occurs in the paper in the image forming apparatus 100, the drying device (heating device) according to the present invention can be installed in the conveying device 300. The drying device 6 can effectively suppress deformation of the paper.

Further, the drying device (heating device) according to the present invention can also be applied to a post-processing device 400 as shown in FIG. 26. The post-processing device 400 includes a drying device 6 that heats the paper, and a post-processing section 401 that performs post-processing such as stapling and punching on the paper.

When the paper is conveyed from the image forming apparatus 100 to the post-processing device 400 shown in FIG. At this time, if the paper is placed face-up (with the image forming surface facing upward), the images may be formed in reverse order (forming from the next page). Further, the paper P placed on the loading tray 403 is transported in the reverse direction by a transport roller 402 provided in the post-processing section 401. As a result, the trailing edge of the paper P hits the trailing edge regulating portion 403a of the loading tray 403, and the trailing edge position of the paper P is aligned. Further, the conveyance roller 402 is configured to be movable from a position where it can contact the paper P to a retreated position where it does not come into contact with the paper P so as not to interfere with paper ejection onto the loading tray 403 . Then, with the trailing edge positions of the sheets P aligned, the sheets P are subjected to stapling processing, punching processing, and the like. Thereafter, the conveyance roller 402 rotates in the reverse direction, and the paper P on the loading tray 403 is discharged to the outside of the post-processing device 400. By applying the drying device (heating device) according to the present invention to such a post-processing device 400, even if deformation such as curl occurs in the paper in the image forming device 100, the drying device (heating device) according to the present invention can be applied to the post-processing device 400. The drying device 6 can effectively suppress deformation of the paper.

In addition, the sheets to be heated using the drying device (heating device) according to the present invention include so-called cut paper that is cut in advance to a predetermined size in the paper conveyance direction, as well as long sheets that are wound into a roll. It may be paper. However, in the case of roll paper, the paper is generally conveyed while being stretched by conveyance rollers placed at intervals in the paper conveyance direction, so deformations such as curling occur in the paper during conveyance. Even when such a force is applied, it is possible to convey the paper while suppressing deformation to some extent by the tension applied to the paper. On the other hand, cut paper is not conveyed while being stretched by conveyance rollers. For this reason, in the case of cut paper, there is a risk that deformation such as curling may cause transport failure or that sufficient drying processing may not be possible.

Therefore, the drying device (heating device) according to the present invention is preferably applied to a device that uses such cut paper. That is, according to the drying device (heating device) according to the present invention, even if the paper is a cut paper, the paper is pressed against the belt member (heating belt) by the pressing member (pressing roller), so that the paper can be transferred to the belt member. Since it is possible to apply a bending correction force to the paper while heating it from the surface opposite to the liquid adhering surface by bringing it into contact with a heating belt, deformation of the paper can be effectively suppressed.

As described above, the drying device (heating device) according to the present invention is particularly suitable for an image forming apparatus using cut paper. However, the present invention does not exclude application to image forming apparatuses that use roll paper. By applying the drying device (heating device) according to the present invention to an image forming apparatus using roll paper, it is possible to effectively suppress paper deformations such as back curl and cockling.

Further, the sheet heated using the drying device (heating device) according to the present invention may be made of a material other than paper. The sheet may be made of paper, resin, metal, cloth, leather, etc. as long as it is flexible and can be conveyed in a curved manner.

3 Image forming section 6 Drying device (heating device)
14 Liquid ejection head (liquid ejection means)
40 Heating belt (heating member)
40a Curved portion 41 Tension roller (belt support member)
42 Fixed roller (belt support member)
43 Press roller (pressing member)
44 Heater (heating source)
45 Spur (protrusion rotating body)
100 Image forming device 300 Conveying device 400 Post-processing device H Length of contact range P Paper (sheet)
Pa Liquid adhesion surface Pb Opposite surface from liquid adhesion surface θ Wrap angle

JP2016-78428A

Claims (12)

Equipped with a heating member that heats the opposite side of the sheet to which the liquid is attached,
The heating member has a curved portion that curves the sheet to pass through so that the liquid adhesion surface is concave,
The sheet is conveyed in contact with the heating member upstream of the curved portion in the sheet conveyance direction ,
The heating member is a belt member wrapped around a plurality of belt support members,
a heating source that heats the belt member;
a pressing member that presses the outer peripheral surface of the belt member between the plurality of belt support members to form the curved portion on the belt member;
a protrusion rotating body having a plurality of protrusions protruding in an outer radial direction and disposed so as to face the outer circumferential surface of the belt member on an upstream side in the sheet conveyance direction than the pressing member;
A heating device comprising : The heating device according to claim 1, wherein the belt support member and the pressing member, which are arranged upstream of the pressing member in the sheet transporting direction, contact the belt member at locations separated from each other in the sheet transporting direction. The heating device according to claim 2, wherein the belt supporting member and the pressing member, which are arranged downstream of the pressing member in the sheet transporting direction, contact the belt member at locations separated from each other in the sheet transporting direction. 4. The heating device according to claim 1, wherein the heat source is arranged upstream of the pressing member in the sheet conveyance direction . The heating device according to any one of claims 1 to 4, further comprising a heat source that heats the pressing member . The heating device according to any one of claims 1 to 5, wherein the length of a contact range in the sheet conveyance direction where the pressing member and the belt member are in contact can be changed . 7. The heating device according to claim 1, wherein the pressing member includes a belt having a large number of unevenness on its outer peripheral surface . 7. The heating device according to claim 1, wherein the pressing member includes a belt formed in a mesh shape . a liquid discharge means for discharging liquid onto the sheet;
The heating device according to any one of claims 1 to 8,
A liquid ejection device comprising: an image forming unit that forms an image by discharging liquid onto a sheet;
The heating device according to any one of claims 1 to 8,
An image forming apparatus comprising: The heating device according to any one of claims 1 to 8,
a post-processing section that processes the sheet that has passed through the heating device;
A post-processing device comprising: The heating device according to any one of claims 1 to 8,
a conveyance path that conveys the sheet to a post-processing section that processes the sheet that has passed through the heating device;
A conveyance device comprising:

Images