Patent Application
20220035280
This application is based on and claims priority under 35 USC 119 from Japanese Patent Application No. 2020-127723 filed Jul. 28, 2020.
The present disclosure relates to a heating device and an image forming apparatus.
Japanese Unexamined Patent Application Publication No. 2011-39148 discloses a fixing device that includes a non-contact transporter that holds and transports a transport-direction leading end of a cut sheet having an unfixed image thereon so that a transport member does not contact two surfaces of the cut sheet, and a non-contact heater that heats in a non-contact manner the cut sheet that is being transported by the non-contact transporter. This fixing device includes a gas blower that blows gas against a front surface and a back surface of the cut sheet that is in a heated state due to the non-contact heater.
In a heating device including a heating unit that heats in a non-contact manner an upper surface of a transport material that is transported and a blowing unit that blows air against a lower surface of the transport material via multiple blowing holes that open with respect to the lower surface, when blowing holes that are closest and adjacent to each other in a transport direction of the transport material are disposed in the transport direction, temperature irregularity of the transport material may occur in an intersection direction that intersects the transport direction.
Aspects of non-limiting embodiments of the present disclosure relate to, when compared with the structure in which blowing holes that are closest and adjacent to each other in the transport direction of a transport material are disposed in the transport direction, a reduction in temperature irregularity in an intersection direction that intersects the transport direction of the transport material.
Aspects of certain non-limiting embodiments of the present disclosure address the above advantages and/or other advantages not described above. However, aspects of the non-limiting embodiments are not required to address the advantages described above, and aspects of the non-limiting embodiments of the present disclosure may not address advantages described above.
According to an aspect of the present disclosure, there is provided a heating device including a heating unit that heats in a non-contact manner an upper surface of a transport material that is transported; and a blowing unit that blows air against a lower surface of the transport material via multiple blowing holes that open with respect to the lower surface, the multiple blowing holes being disposed so that blowing holes that are closest and adjacent to each other in a transport direction of the transport material are shifted from each other in an intersection direction that intersects the transport direction.
Exemplary embodiments of the present disclosure will be described in detail based on the following figures, wherein:
Examples of exemplary embodiments of the disclosure are described below based on the drawings. Note that arrow H shown in a corresponding one of the figures indicates a vertical direction and an apparatus up-down direction, arrow W indicates a horizontal direction and an apparatus width direction, and arrow D indicates an apparatus front-back direction (an apparatus far-side direction).
A structure of an image forming apparatus 10 according to an exemplary embodiment is described.
The image forming apparatus 10 shown in
Each accommodation unit 50 shown in
The discharge unit 52 shown in
The image forming unit 12 shown in
The transfer drum 13 is provided above a transport path of a sheet P that is transported by the transport device 16, and is disposed at a position allowing the transfer drum 13 to contact an upwardly facing surface (hereunder referred to as “upper surface”) of the sheet P. The transfer drum 13 is rotationally driven in a direction E in
The ejection units 14Y to 14K eject ink drops of corresponding colors, that is, yellow (Y), magenta (M), cyan (C), and black (K), onto an outer peripheral surface of the transfer drum 13 to form images on the outer peripheral surface of the transfer drum 13. The ejection units 14Y to 14K are disposed in this order toward a downstream side in a rotation direction of the transfer drum 13 (the direction E). The ejection units 14Y to 14K each have a length in an axial direction of the transfer drum 13. The ejection units 14Y to 14K each eject onto the outer peripheral surface of the transfer drum 13 ink drops from nozzles (not shown) by a publicly known method, such as a thermal method or a piezoelectric method.
In the image forming unit 12, the ejection units 14Y to 14K each eject ink drops of the corresponding color onto the outer peripheral surface of the transfer drum 13 to form images on the outer peripheral surface of the transfer drum 13. Further, in the image forming unit 12, the images that have been formed on the outer peripheral surface of the transfer drum 13 are transferred to a sheet P that passes between the transfer drum 13 and the opposing roller 15. Therefore, the images are formed on the upper surface of the sheet P. Note that the opposing roller 15 has a recessed portion 17 for reducing interference with grippers 76 (described later) of the transport device 16. When the grippers 76 pass between the transfer drum 13 and the opposing roller 15, the grippers 76 pass therebetween while being inserted in the recessed portion 17.
The heating device 100 is a device that heats a sheet P. Specifically, the heating device 100 has the function of heating and thereby drying ink on the sheet P. More specifically, as shown in
The heating unit 102 has the function of heating in a non-contact manner an upper surface of a sheet P that is transported by the transport device 16 (specifically, a transport mechanism 60 described later). Specifically, the heating unit 102 heats in a non-contact manner an upper surface of a sheet P on which an image has been formed by the image forming unit 12. More specifically, the heating unit 102 includes a reflecting plate 104, multiple heaters 106 (heating sources), and a wire net 112. Note that a structure of the blowing device 160 is described below.
The reflecting plate 104 has the function of reflecting downward infrared rays from the heaters 106 (that is, toward the side of a sheet P that is transported by the transport device 16). The reflecting plate 104 has the shape of a box with an open lower side. The reflecting plate 104 is formed by using, for example, a metal plate, such as an aluminum plate.
Each heater 106 is a columnar infrared heater having a length in a width direction of a sheet P (hereunder may be called “sheet-width direction”). The heaters 106 are disposed side by side inside the reflecting plate 104 in the transport direction. Note that the sheet-width direction is an intersection direction that intersects the transport direction (specifically, an orthogonal direction). In a corresponding one of the figures, the sheet-width direction is indicated by a direction of a double-headed arrow Y.
The wire net 112 is disposed at the opening on the lower side of the reflecting plate 104. Therefore, the wire net 112 partitions the inside and the outside of the reflecting plate 104. The wire net 112 may prevent contact of the heaters 106 and a sheet P that is transported by the transport device 16.
As shown in
Each cooling roller 92 is a circular cylindrical roller that is made of, for example, a metal. Each cooling roller 92 has a structure that, by allowing a refrigerant, such as air or water, to flow therein, cools a sheet P by heat exchange with the refrigerant.
The transport device 16 shown in
The transport mechanism 60 shown in
The transport mechanism 60 transports the sheet P with one of the surfaces of the sheet P facing upward in the image forming unit 12 and the heating device 100. The one of the surfaces is an image surface on which an image is formed in the image forming unit 12, and is a surface that is heated in the heating device 100.
Specifically, as shown in
Each sending roller 62 sends out a sheet P accommodated in a corresponding one of the accommodation units 50. The multiple transport rollers 64 transport the sheet P that has been sent out by the sending roller 62 to the chain gripper 66.
As shown in
As shown in
As shown in
As shown in
As shown in
Note that the front end portion of the sheet P is an example of a downstream-side portion of a transport material in the transport direction. The rear-end-side portion of the sheet P is an example of a one-end-side portion of the transport material in the transport direction, and is an example of an upstream-side portion of the transport material in the transport direction. A portion of a transport path in which the sheet P is transported in the transport mechanism 60 is indicated by an alternate long and short dashed line in
The blowing device 160 shown in
The blowing device 160 is a device that blows air against a lower surface of a sheet P that is transported by the chain gripper 66. Specifically, as shown in
An example of the fan 161 is an axial-flow blower that blows air in an axial direction. Note that the fan 161 may be a centrifugal blower that blows air in a centrifugal direction, such as a multi-blade blower (for example, a sirocco fan), and is a blower that blows air. Note that the fan 161 is an example of a blower.
The blowing plate 180 is mounted on upper ends of the side walls 163 so as to cover the opening in an upper portion of the device body 166. Therefore, the device body 166 is hermetically sealed except the opening 164 and blowing holes 182 described below.
The blowing plate 180 has the shape of a plate in which the up-down direction is a thickness direction, and has an opposing surface 181 that opposes the heating unit 102. The opposing surface 181 faces upward and opposes a lower surface of a sheet P that is transported between the heating unit 102 and the blowing plate 180.
The blowing plate 180 is constituted by a metal plate. The blowing plate 180 also has the function of a reflecting plate that reflects upward (toward the side of a sheet P that is transported by the chain gripper 66) infrared rays from the heaters 106.
The blowing plate 180 has the multiple blowing holes 182 that extend through the blowing plate 180 in the up-down direction. That is, the multiple blowing holes 182 are provided in the opposing surface 181 and open with respect to a lower surface of a sheet P that is transported between the heating unit 102 and the blowing plate 180.
As shown in
In the blowing device 160, the fan 161 is driven to blow air that has flowed into the device body 166 against a lower surface of a sheet P that is transported by the chain gripper 66 via the multiple blowing holes 182 (see
Here, as shown in
Blowing holes 182 that are closest and adjacent to each other in the transport direction are disposed so as to be shifted from each other in the sheet-width direction. The blowing holes 182 that are adjacent to each other in the transport direction are blowing holes 182 that are next to each other in the transport direction, and are blowing holes 182 that are disposed at a closest location on an upstream side or on a downstream side in the transport direction. For example, blowing holes 182 that are adjacent to blowing holes 182(B) include multiple blowing holes belonging to row 185(A) and multiple blowing holes 182 that belong to row 185(C). A blowing hole 182 that is closest to a blowing hole (B) is a blowing hole 182(A) among the multiple blowing holes that belong to the row 185(A). A blowing hole 182 that is closest to the blowing hole 182(B) is a blowing hole 182(C) among the multiple blowing holes 182 that belong to the row 185(C).
In the exemplary embodiment, “the blowing hole 182(A) and the blowing hole 182(B)” that are blowing holes 182 that are closest and adjacent to each other in the transport direction are disposed so as to be shifted from each other in the sheet-width direction. “The blowing hole 182(B) and the blowing hole 182(C)” that are blowing holes 182 that are closest and adjacent to each other in the transport direction are disposed so as to be shifted from each other in the sheet-width direction.
In the exemplary embodiment, blowing holes 182 that are closest to each other in rows 185 that are adjacent to each other in the transport direction are said to be disposed so as to be shifted from each other in the sheet-width direction. The rows 185 that are adjacent to each other in the transport direction are rows 185 that are next to each other in the transport direction, and are rows 185 that are disposed at a closest location on an upstream side or a downstream side in the transport direction. For example, rows 185 that are adjacent to row 185(B) are the row 185(A) and the row 185(C).
When seen from the blowing hole 182(B) in the row 185(B), the blowing hole 182(A) that belongs to the row 185(A) that is adjacent to the row 185(B) is the closest blowing hole 182. When seen from the blowing hole 182(B), the blowing hole 182(C) that belongs to the row 185(C) that is adjacent to the row 185(B) is the closest blowing hole 182. That is, the blowing holes that are closest to each other in the corresponding rows 185 that are adjacent to each other in the transport direction are, for example, the blowing hole 182(A) and the blowing hole 182(B), and the blowing hole 182(B) and the blowing hole 182(C).
In the exemplary embodiment, “the blowing hole 182(A) and the blowing hole 182(B)” that are blowing holes 182 that are closest to each other in the corresponding rows 185 that are adjacent to each other in the transport direction are disposed so as to be shifted from each other in the sheet-width direction. “The blowing hole 182(B) and the blowing hole 182(C)” that are blowing holes 182 that are closest to each other in the corresponding rows 185 that are adjacent to each other in the transport direction are disposed so as to be shifted from each other in the sheet-width direction.
Further, in the exemplary embodiment, the blowing holes 182 that are closest and adjacent to each other in the transport direction (for example, the blowing hole 182(A) and the blowing hole 182(B)) are disposed so as to be in their entirety shifted from each other in the sheet-width direction. That is, the blowing holes 182 that are closest and adjacent to each other in the transport direction are disposed with a predetermined interval DL therebetween in the sheet-width direction. In other words, the blowing holes 182 that are closest and adjacent to each other in the transport direction do not overlap each other when seen in the transport direction.
The blowing holes 182 that are closest and adjacent to each other in the transport direction are disposed, specifically, so as to be gradually shifted in the sheet-width direction every ¼ pitch (interval indicated by symbol ¼P in
Further, in the exemplary embodiment, a parallelogram is formed by lines LA that connect each blowing hole of a pair of blowing holes (for example, the blowing hole 182(A) and the blowing hole 182(B)) that are closest and adjacent to each other in the transport direction and each blowing hole of a pair of blowing holes (for example, a blowing hole 182(E) and a blowing hole 182(F)) that are in the sheet-width direction adjacent to the pair of blowing holes that are closest and adjacent to each other in the transport direction. A parallelogram is an example of a shape other than a square. A square is a right-angled square having four angles. A square refers to a regular square and a rectangle. The lines LA are lines that connect the centers of the blowing holes 182.
The reversing mechanism 80 shown in
The multiple transport rollers 82 transport a sheet P that has been sent from the heating device 100 to the reversing device 84. The reversing device 84 reverses the front and the back of the sheet P. The multiple transport rollers 86 transport the sheet P whose front and back have been reversed by the reversing device 84 to the chain gripper 66. That is, the multiple transport rollers 86 each have the function of transferring the sheet P whose front and back have been reversed to the chain gripper 66.
In this way, the reversing mechanism 80 reverses the top and bottom of the sheet P that has passed a location between the heating unit 102 and the opposing surface 181 and transfers the sheet P to the chain gripper 66 to thereby cause the chain gripper 66 to transport again the transferred sheet P with its surface having a heated and dried image formed thereon facing downward to the location between the heating unit 102 and the opposing surface 181 via the image forming unit 12. Note that a portion of a transport path in which the sheet P is transported in the reversing mechanism 80 is indicated by an alternate long and short dashed line in
In the exemplary embodiment, a sheet P that has been sent out from a corresponding one of the accommodation units 50 shown in
When an image is to be formed on only one side of a sheet P, the sheet P whose image has been dried by the heating device 100 is discharged to the discharge unit 52 after being cooled by the cooling rollers 92 of the cooling unit 90.
When images are to be formed on both sides of a sheet P, the sheet P whose image on one side has been dried has its front and back reversed by the reversing mechanism 80 shown in
Here, in the exemplary embodiment, as shown in
For example, as shown in
In contrast, in the exemplary embodiment, since, as shown in
Therefore, according to the structure of the exemplary embodiment, compared with the structure shown in
In the exemplary embodiment, the blowing holes 182 that are closest and adjacent to each other in the transport direction (for example, the blowing hole 182(A) and the blowing hole 182(B)) are disposed so as to be in their entirety shifted from each other in the sheet-width direction. Therefore, compared with the structure in which portions of the blowing holes 182 that are closest and adjacent to each other in the transport direction overlap each other in the sheet-width direction, temperature irregularity in the sheet-width direction of a sheet P may be suppressed.
Further, in the exemplary embodiment, a parallelogram is formed by the lines LA that connect each blowing hole of the pair of blowing holes (for example, the blowing hole 182(A) and the blowing hole 182(B)) that are closest and adjacent to each other in the transport direction and the pair of blowing holes (for example, the blowing hole 182(E) and the blowing hole 182(F)) that are in the sheet-width direction adjacent to the pair of blowing holes that are closest and adjacent to each other in the transport direction.
For example, as shown in
In contrast, in the exemplary embodiment, since a parallelogram is formed by the lines LA that connect each blowing hole of the pair of blowing holes (for example, the blowing hole 182(A) and the blowing hole 182(B)) and each blowing hole of the pair of blowing holes (for example, the blowing hole 182(E) and the blowing hole 182(F)) that in the sheet-width direction are adjacent to the pair of blowing holes (for example, the blowing hole 182(A) and the blowing hole 182(B)), compared with the structures shown in
As described above, in the exemplary embodiment, since temperature irregularity in the sheet-width direction of a sheet P may be suppressed, heating unevenness in the sheet-width direction of an image formed on the sheet P may be suppressed. In addition, in the exemplary embodiment, since the blowing holes 182 are disposed so as to be dispersed in the sheet-width direction, the positions on the sheet P against which air blows are dispersed in the sheet-width direction, as a result of which variations in the sheet-width direction in the raised amount of the sheet P caused by air blowing from the multiple blowing holes 182 may be suppressed.
In the first exemplary embodiment, although the image forming apparatus 10 is an inkjet image forming apparatus that forms an image on a sheet P by using ink, an image forming apparatus is not limited thereto. An example of an image forming apparatus may be an electrophotographic image forming apparatus and is an apparatus that forms an image. In a second exemplary embodiment, an electrophotographic image forming apparatus 200 is described.
The image forming apparatus 200 includes an image forming unit 212 instead of the image forming unit 12. The image forming apparatus 200 also includes a fixing unit 120 (an example of a fixing device).
The image forming unit 212 shown in
The toner-image forming units 20 are provided so as to form toner images according to color. The image forming apparatus 10 includes the toner-image forming units 20 for a total of four colors, that is, yellow (Y), magenta (M), cyan (C), and black (K). (Y), (M), (C), and (K) shown in
The toner-image forming units 20 for the corresponding colors basically have the same structure except in the toner used. Specifically, as shown in
The transfer device 30 shown in
Each first-transfer roller 33 has the function of transferring the toner image formed on the photoconductor drum 21 corresponding thereto to the transfer belt 31 at a first-transfer position T (see
As shown in
The transfer unit 35 has the function of transferring to a sheet P the toner images transferred to the transfer belt 31. Specifically, the transfer unit 35 includes a second-transfer unit 34 and an opposing roller 36.
The opposing roller 36 is disposed on a lower side of the transfer belt 31 so as to oppose the transfer belt 31. As shown in
The fixing unit 120 shown in
In the exemplary embodiment, although the description is made by using the fixing unit 120 that heats and presses a sheet, the fixing may be performed without heating, and if the purpose is to improve the surface nature of toner that is fused by the heating device 100 in the previous step, for example, to adjust gloss, the fixing may be performed only by pressing by a pressing unit.
As shown in
The heating roller 130 shown in
The heating roller 130 includes a circular cylindrical base 132, a rubber layer 134 that is formed around an outer periphery of the base 132, a release layer 136 that is formed around an outer periphery of the rubber layer 134, and a heater 138 (heating source) that is accommodated inside the base 132. The heater 138 is constituted by, for example, a single halogen lamp or multiple halogen lamps.
The driven roller 150 shown in
The pressing roller 140 shown in
The pressing roller 140 includes a circular cylindrical base 142, a rubber layer 144 that is formed around an outer periphery of the base 142, and a release layer 146 that is formed around an outer periphery of the rubber layer 144.
The circumference of the pressing roller 140 is equal to the arrangement interval of grippers 76 at chains 72. As shown in
When the grippers 76 that hold a front end portion of a sheet P pass between the pressing roller 140 and the heating roller 130, the grippers 76 enter the recessed portion 148.
Note that, in the fixing unit 120, the pressing roller 140 is rotationally driven by a driving unit (not shown), the heating roller 130 is rotated by being driven by the pressing roller 140, and the driven roller 150 is rotated by being driven by the heating roller 130.
In the exemplary embodiment, a sheet P that is sent out from an accommodation unit 50 shown in
The sheet P whose toner images have been heated by the heating device 100 is further transported to the fixing unit 120 by the chain gripper 66 and is pressed and heated by being nipped by the heating roller 130 and the pressing roller 140. Therefore, the toner images are fixed to the sheet P. When an image is to be formed on only one side of the sheet P, the sheet P to which the toner images have been fixed is cooled by cooling rollers 92 of a cooling unit 90 shown in
When images are to be formed on both sides of the sheet P, the sheet P to which the image has been fixed to one side thereof has its front and back reversed by a reversing mechanism 80 shown in
Similarly to the above, the sheet P to which the toner images have been transferred is heated by the heating device 100 and is then pressed and heated by being nipped by the heating roller 130 and the pressing roller 140 to fix the toner images to the sheet P. The sheet P to which the toner images have been fixed is cooled by the cooling rollers 92 of the cooling unit 90 and is then discharged to the discharge unit 52.
Even in the exemplary embodiment, since, as shown in
Although, in the exemplary embodiment, the blowing holes 182 are disposed at equal intervals in the sheet-width direction in each of the rows 185, it is not limited thereto. For example, a structure in which the blowing holes 182 are disposed at a first interval and at a second interval, which is wider than the first interval, in the sheet-width direction in corresponding ones of the rows 185 may be used (see
Although, in the exemplary embodiment, the arrangement interval in which the blowing holes 182 are disposed at equal intervals in each of the rows 185 is the same for each row 185, it is not limited thereto. The arrangement interval in which the blowing holes 182 are disposed may differ for each row 185.
In the exemplary embodiment, the blowing holes 182 (for example, the blowing hole 182(A) and the blowing hole 182(B)) that are closest and adjacent to each other in the transport direction are disposed so as to be in their entirety shifted from each other in the sheet-width direction. However, it is not limited thereto. For example, a structure in which portions of the blowing holes 182 that are closest and adjacent to each other in the transport direction overlap each other in the sheet-width direction may be used.
In the exemplary embodiment, a parallelogram is formed by the lines LA that connect each blowing hole of the pair of blowing holes (for example, the blowing hole 182(A) and the blowing hole 182(B)) that are closest and adjacent to each other in the transport direction and each blowing hole of the pair of blowing holes (for example, the blowing hole 182(E) and the blowing hole 182(F)) that in the sheet-width direction are adjacent to the pair of blowing holes that are closest and adjacent to each other in the transport direction. However, it is not limited thereto. For example, as shown in
In the first and second exemplary embodiments above, the chain gripper 66 transports a sheet P with the grippers 76 holding a front end portion of the sheet P. However, the grippers 76 may hold at least a front-end-side portion of the sheet P. The front-end-side portion of the sheet P is a portion that is situated on a downstream side (front side) with respect to the center of the sheet P in the transport direction.
In the first and second exemplary embodiments above, the grippers 76 that are disposed on a downstream side with respect to a sheet P in the transport direction hold a front end portion of the sheet P from a downstream side of the sheet P in the transport direction. However, it is not limited thereto. The grippers 76 may hold a front-end-side portion of the sheet P from two end sides in the sheet-width direction with respect to the sheet P.
In the first and second exemplary embodiments above, with a front end portion of a sheet P being held by the chain gripper 66 and without a rear-end-side portion thereof being held, the sheet P is transported between the heating unit 102 and the blowing device 160. However, it is not limited thereto. For example, a structure in which a sheet P is transported between the heating unit 102 and the blowing device 160 by a pair of transport rollers may be used. Even in such a structure, in the process of nipping and transporting the sheet P by the pair of transport rollers, the sheet P is transported with a front-end-side portion of the sheet P being held and without the rear-end-side portion thereof being held.
Further, in this structure, in the process of nipping and transporting the sheet P by the pair of transport rollers, the sheet P is transported with the rear-end-side portion of the sheet P being held and without the front-end-side portion thereof being held. In this case, the front-end-side portion of the sheet P is an example of a one-end-side portion of a sheet-like transport material in the transport direction. In this way, an example of the one-end-side portion of the sheet-like transport material in the transport direction may be not only the rear-end-side portion of the sheet P but also the front-end-side portion of the sheet P.
In the first and second exemplary embodiments above, as an example of a sheet-like transport material, a sheet P is used. However, it is not limited thereto. Here, “transport material” in a “sheet-like transport material” refers to a material that is transported. “Sheet” in a “sheet-like transport material” refers to, for example, paper or a thin plate. Therefore, “sheet-like” refers to a shape of, for example, paper or a thin plate, without the property of the material being considered. Consequently, an example of a sheet-like transport material may be, for example, a heat-resistant resin film or a metal film, and is any sheet-like material that can be transported.
The present disclosure is not limited to the exemplary embodiments above, and various modifications, changes, or improvements are possible within a scope that does not depart from the spirit of the present disclosure. For example, a structure may be formed by combining multiple modifications described above as appropriate.
The foregoing description of the exemplary embodiments of the present disclosure has been provided for the purposes of illustration and description. It is not intended to be exhaustive or to limit the disclosure to the precise forms disclosed. Obviously, many modifications and variations will be apparent to practitioners skilled in the art. The embodiments were chosen and described in order to best explain the principles of the disclosure and its practical applications, thereby enabling others skilled in the art to understand the disclosure for various embodiments and with the various modifications as are suited to the particular use contemplated. It is intended that the scope of the disclosure be defined by the following claims and their equivalents.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2020-127723 | Jul 2020 | JP | national |
