Patent Grant
9625861
Field of the Invention
The present invention relates to a sheet cooling apparatus used for cooling a sheet, which is formed from paper fibers or the like, that is a target for heating, pressing, and fixing an unfixed toner image in an image forming apparatus such as a copying machine, a printer, or a facsimile machine.
Description of the Related Art
Conventionally, in image forming apparatuses such as electro-photographic apparatuses and electrostatic recording apparatuses, an image is formed on a sheet by forming a toner image on the sheet as a recording material and fixing the toner image using a fixing device by heating and pressing the toner image. As fixing devices used in such image forming apparatuses, a roller fixing system is employed in which a pressing nip portion (fixing nip portion) is formed by pressing a pressure roller to a fixing roller having an internal heater and performing fixing by performing heating and pressing in the pressing nip portion.
In a fixing device of the roller fixing system, heat is applied to toner and a sheet, and accordingly, moisture contained in the sheet evaporates in the pressing nip portion and after passing the pressing nip portion. Then, ripples and curls occur due to a change in the amount of moisture of the sheet and stress applied to the sheet.
When a sheet is viewed in the level of fibers, the sheet is formed by entangling short fibers with each other, moisture is contained inside the fibers or between the fibers, and the fibers and water generate hydrogen bonding. In a fixing process, when heat is applied to the sheet, the moisture included inside the sheet evaporates, and accordingly, the hydrogen bonding occurs between the fibers, whereby the sheet is deformed. When the sheet is left around, the sheet absorbs moisture from the environment, and the hydrogen bonding between the fibers is broken again. However, moisture is not permeated between some fibers, whereby the deformation is maintained.
As a pattern of the deformation, there are deformations according to a difference in the expansion and contraction between the front and rear sides of a sheet and deformation according to a difference in the expansion and contraction between a center portion and an end portion of a sheet. In accordance with such deformation, ripples and curls occur in the sheet.
In order to solve such a problem, a configuration is disclosed in which the sheet is cooled as below.
In Japanese Patent Laid-Open No. 2009-161347, a bending portion bending in a direction opposite to the bending of a sheet on which an image is fixed by a fixing portion in the conveying direction is included. In addition, a cooling member that cools a sheet conveyed by a belt member through the belt member in an area including the bending portion and a pressing member that presses a sheet to the bending portion side of the cooling member are included.
In Japanese Patent Laid-Open No. 2009-175260, a configuration is disclosed in which an endless belt member having good heat conductivity is stretched over belt cooling rollers that are aligned from a fixing device in the conveying direction. Then, a sheet heated by the fixing device is brought into contact with the endless belt member stretched between the belt rollers so as to be cooled, and the endless belt member heated by the sheet is cooled by the belt cooling rollers.
However, among the above-described conventional technologies, in the technology disclosed in Japanese Patent Laid-Open No. 2009-161347, there is concern that tension of the belt member may increase, and deterioration due to abrasion caused by a contact load of the belt member for the cooling member may become serious.
In addition, in the technology disclosed in Japanese Patent Laid-Open No. 2009-175260, since the contact area between the endless belt member and the belt cooling rollers is small, there is concern that the heat transfer to the endless belt member is lowered in accordance with an increase in the number of continuously passing sheets.
It is desirable to improve the durability by decreasing the abrasion of a cooling belt and members brought into contact with the inner face of the cooling belt and to realize improvement of the cooling ability.
According to the invention, there is provided a sheet cooling apparatus that cools a sheet while conveying the sheet passing through a fixing device fixing an unfixed toner image formed on the sheet by heating the toner image. The sheet cooling apparatus includes: a first endless belt that is suspended on a first cooling roller and a first suspension member arranged downstream of the first cooling roller in a conveying direction; and a second endless belt that is suspended on a second cooling roller arranged downstream of the first cooling roller in the conveying direction and a second suspension member arranged upstream of the second cooling roller in the conveying direction; wherein the second suspension member is arranged so as to press the second endless belt on a circumferential face of the first cooling roller through the first endless belt, the first suspension member is arranged so as to press the first endless belt on a circumferential face of the second cooling roller through the second endless belt, and a curved sheet conveying path is formed between the first endless belt and the second endless belt.
According to the invention, by using the cooling roller, the conveying resistance due to friction with a belt can be markedly lower than that of the fixed type, and accordingly, the belts and the sheet can be conveyed in a stable manner, and the driving load can be reduced.
In addition, by forming the curved conveying path bent in the shape of “S” along the circumferential face of the cooling roller, the belt and each cooling roller can be brought into contact with each other in the entire area of the sheet conveying path, whereby the cooling efficiency for the sheet can be improved.
Furthermore, by forming the curved conveying path bent in the shape of “S” other than a conveying path having an approximately linear shape, the miniaturization of the whole apparatus can be achieved, and the curl and the ripple can be reduced by acquiring a curl correction effect for the sheet.
Further features of the present invention will become apparent from the following description of exemplary embodiments with reference to the attached drawings.
Hereinafter, exemplary embodiments of the invention will be described in detail as examples with reference to the drawings. However, the sizes, the materials, the shapes, and the relative arrangements of constituent components described in the following embodiments should be appropriately changed in accordance with the configuration and various conditions of devices and apparatuses to which the invention is applied. Accordingly, unless there is specific description, the embodiments are not for purposes of limiting the scope of the invention thereto.
A sheet cooling apparatus and an image forming apparatus including the sheet cooling apparatus will be described with reference to
The printer 500 illustrated in
Sheets P as recording materials are sent from a sheet cassette 520 one by one and are conveyed to a pair of registration rollers 523. The pair of registration rollers 523 receives the sheet P once and, in a case where the sheet P is fed on a skew, the skew feeding is immediately corrected. Then, the pair of registration rollers 523 sends the sheets P between the intermediate transfer belt 531 and a secondary transfer roller 535 in synchronization with a toner image formed on the intermediate transfer belt 531. The color toner images formed on the intermediate transfer belt 531 are transferred together to the sheet P by the secondary transfer roller 535 as a transfer portion.
Thereafter, the unfixed toner images T formed on the sheet P are fixed to the sheet P by being heated and pressed by a fixing device 100. After passing through the fixing device 100, the sheet P is cooled while being conveyed to the inside of a cooling apparatus 101 as a sheet cooling apparatus and is discharged to a discharge tray 565 with the face up (the toner image is disposed on the upper side).
The fixing device 100 and the cooling apparatus 101 as a sheet cooling apparatus will be described with reference to
As illustrated in
The pressure roller 111 conveys the sheet P cooperatively with the fixing roller 110. The pressure roller 111 includes a metal core formed by an aluminum cylindrical pipe, for example, having an outer diameter of 56 mm and an inner diameter of 50 mm. In addition, the pressure roller 111 is acquired by coating the surface of the metal core with an elastic layer formed from silicon rubber, for example, having a thickness of 2 mm and a hardness (ASKER C) of 45° and further coating the surface layer of the elastic layer with a PFA or PTFE heat-resistant toner parting layer.
The fixing device 100 forms a fixing nip (pressing nip) N illustrated in
The sheet P that is conveyed to the fixing device 100 by the photosensitive drum 511 and the transfer roller 535 enters the fixing nip N of the fixing roller 110 and the pressure roller 111. The fixing roller 110 is heated and pressed inside the fixing nip N formed by the fixing roller 110 and the pressure roller 111, whereby the unfixed toner image T is fixed to the sheet P. The sheet P on which the image is fixed, as illustrated in
The sheet P discharged from the fixing device 100 is guided to the cooling apparatus 101 by the guides 501 and 502 and is cooled so as to remove the heat applied by the fixing device 100 while being conveyed by the cooling apparatus 101.
As illustrated in
The cooling belts 302 and 202 are endless belts (endless belt members) that are brought into contact with the face of a sheet and convey the sheet. The cooling belts 302 and 202 may be formed from a material having superior thermal conductivity and may be formed from a material such as a polyimide film, a nickel electroformed film, or a polyethylene film that can form a thin plate.
The cooling belt 202 as a second endless belt performs frictional conveyance while being brought into contact with the rear surface of the sheet P. This cooling belt 202, as illustrated in
The cooling roller 201 is arranged on the downstream of a cooling roller 301 as a first cooling roller to be described later in the conveying direction. The belt pressure rollers 204 and 205 as the second suspension members and the tension roller 203 are arranged on the upstream of the cooling roller 201 in the conveying direction.
The cooling belt 202, the cooling roller 201, the belt pressure rollers 204 and 205, and the tension roller 203, as illustrated in
The cooling roller 201, as illustrated in
As illustrated in
On the outer face of the rear side plate 220, as illustrated in
The belt pressure rollers 204 and 205, as illustrated in
Between pressure spring bearing faces 210c and 220c integrally formed on the outer faces of the front side plate 210 and the rear side plate 220 and the pressure arms 212 and 222, pressure springs 214 and 224 of the compression coil type are inserted, and the pressure springs 214 and 224 bias the pressure arms 212 and 222 in a direction pushing them up. Accordingly, the belt pressure rollers 204 and 205 supported by the pressure arms 212 and 222 among a plurality of second suspension members are pressed to the cooling roller 301 through the cooling belts 302 and 202. Here, although a configuration has been described as an example in which two rollers 204 and 205 among the plurality of second suspension members, which are disposed, are pressed to the cooling roller 301, the configuration is not limited thereto, and at least one suspension member may be pressed to the cooling roller.
On the outer faces of the front side plate 210 and the rear side plate 220, belt tensioners 215 and 225 used for applying tension to the cooling belt 202 are arranged. Tension roller bearings 218 and 228 supporting both end portions of the tension roller 203 to be rotatable are supported also by hollow inner walls of tensioner holders 216 and 226 having hollow inner portions in the shape of a rectangle so as to be slidable in the horizontal direction in
In addition, on the outer faces of the front side plate 210 and the rear side plate 220 used for supporting the tension roller 203, unit supporting shafts 210d and 220d used for supporting the front side plate 310 and the rear side plate 320 to be swingable are integrally formed. The front side plate 310 and the rear side plate 320 configure a frame of the cooling belt unit 300 that is the other cooling belt unit including the cooling belt 302 on the inside thereof.
Furthermore, in uppermost portions of the outer faces of the front side plate 210 and the rear side plate 220, unit pressure spring engaging portions 210a and 220a, as illustrated in
The cooling belt 302 as a first endless belt performs frictional conveyance while being brought into contact with the front surface of the sheet P. This cooling belt 302, as illustrated in
The cooling roller 301 is arranged on the upstream of the cooling roller 201 in the conveying direction as the second cooling roller described above. The belt pressure rollers 303 and 304 as the first suspension members and the tension roller 305 are arranged on the downstream of the cooling roller 301 in the conveying direction.
The cooling belt 302, the cooling roller 301, the belt pressure rollers 303 and 304, and the tension roller 305, as illustrated in
The cooling roller 301, as illustrated in
As illustrated in
The belt pressure rollers 303 and 304, as illustrated in
Between pressure spring bearing faces 310c and 320c integrally formed on the outer faces of the front side plate 310 and the rear side plate 320 and the pressure arms 312 and 322, pressure springs 314 and 324 of the compression coil type are inserted, and the pressure springs 314 and 324 bias the pressure arms 312 and 322 in a direction pushing them down. Accordingly, the belt pressure rollers 303 and 304 supported by the pressure arms 312 and 322 among a plurality of first suspension members are pressed to the cooling roller 201 through the cooling belts 302 and 202. Here, although a configuration has been described as an example in which two rollers 303 and 304 among the plurality of first suspension members, which are disposed, are pressed to the cooling roller 201, the configuration is not limited thereto, and at least one suspension member may be pressed to the cooling roller.
On the outer faces of the front side plate 310 and the rear side plate 320, belt tensioners 315 and 325 used for applying tension to the cooling belt 302 are arranged. Tension roller bearings 318 and 328 supporting both end portions of the tension roller 305 to be rotatable are supported also by hollow inner walls of tensioner holders 316 and 326 having hollow inner portions in the shape of a rectangle so as to be slidable in the horizontal direction in
In addition, on the outer faces of the front side plate 310 and the rear side plate 320 used for supporting the tension roller 305, bearings 310d and 320d used for allowing the front side plate 310 and the rear side plate 320 to be supported by the unit supporting shafts 210d and 220d on the side faces of the front side plate 210 and the rear side plate 220 to be swingable are held. The front side plate 210 and the rear side plate 220 configure a frame of the cooling belt unit 200 that is the other cooling belt unit including the cooling belt 202 on the inside thereof.
Furthermore, in uppermost portions of the outer faces of the front side plate 310 and the rear side plate 320, unit pressure spring engaging portions 310a and 320a for hooking upper one ends of the unit pressure springs 280 and 281 are integrally formed. The unit pressure springs 280 and 281 are disposed for pressing the cooling belt units 200 and 300 illustrated in
In the cooling belt units 200 and 300, the unit supporting shafts 210d and 220d disposed on the side faces of the front side plate 210 and the rear side plate 220 fit into the bearings 310d and 320d held on the side faces of the front side plate 310 and the rear side plate 320. The cooling rollers 201 and 301 contact each other at a point B illustrated in
Accordingly, as illustrated in
In addition, the cooling rollers 201 and 301 that suspend the cooling belts 202 and 302 press each other, and a conveying path that is a sheet conveying path is bent in the shape of “S” so as to be arranged as denoted by a thick line in
The cooling rollers 201 and 301 are formed from members (here, aluminum members) having a high heat radiation effect and, as illustrated in
In addition, in the spaces of the hollow inner portions of the cooling rollers 201 and 301, as illustrated in
Furthermore, the spiral shaped heat radiation fins 201a and 301a cause cooling air to be generated inside in accordance with the rotation of the cooling rollers 201 and 301. As illustrated in
The cooling roller 201 rotates in the counterclockwise direction as illustrated in
A path length from the contact point A to the contact point C that is a conveying path illustrated in
An experiment relating to sheet cooling was performed by the inventors of the invention under the condition that the set temperature of the surface layer of the fixing roller 110 was 180° C., the set temperature of the surface layer of the pressure roller 111 was 100° C., the ambient temperature was 23° C., and the ambient humidity was 50%. As an example of a specific experiment, under this condition, an experiment was performed in which a sheet P that was plain paper having a basis weight of about 70 to 80 g and an internal moisture content of about 6% is conveyed at an conveying speed of about 300 to 500 mm/sec. Then, an experiment result was acquired in which the sheet P right after passing through the fixing nip N was heated to a surface temperature of about 90° C., and the internal moisture content decreased to about 4%.
At this time, the sheet P heated and pressed inside the fixing nip portion N receives heat more from the fixing roller 110 having high temperature than from the pressure roller 111, and fibers grow more on the upper face side of the sheet P that is the fixing roller 110 side than on the lower face side of the sheet P that is the pressure roller 111 side. From this, consequently, a curl formed in the lower direction (hereinafter, referred to as a downward curl) occurs in the sheet P. In addition, the moisture content near the end portion of the sheet P in the width direction decreases more, in which one side is not bound, and moisture movement from/to the air can easily occur, decreases more than in the center portion of the sheet P in the width direction in which the periphery is restrained by the fiber structure. Accordingly, since the fibers of the sheet P can easily grow, and, consequently, a phenomenon (hereinafter, referred to as a ripple) occurs in which the surface of the end portion of the sheet P is deformed in a shape having ripples in the vertical direction.
Under the above-described condition, for example, there are cases where the amount of the downward curl occurring in the front end portion and the rear end portion of the sheet P is 10 to 15 mm, and the height of the ripple in the end portion in the width direction is about 1.5 to 2 mm.
In the path from the contact point A to the contact point C (denoted by a thick line in
The path length from the contact point A to the contact point C is set to about 400 mm to 450 mm as described above. In such a case, in the sheet P passing the nip portion N and further passing an area between the upper discharge guide 501 and the lower discharge guide 502, the upper face side and the lower face side are cooled to about 30° C. to 50° C. by the cooling rollers 301 and 201, respectively, from the contact point A to the contact point C that is a cooling conveying path. Simultaneously, between the contact point A and the contact point B, the sheet P is corrected for the curl upwardly in accordance with the curvature of the upward bending path according to the curvature of the cooling roller 301, and the amount of the downward curl occurring in the front end portion and the rear end portion of the sheet P is enhanced to be 0 to 5 mm.
In addition, an abrupt decrease in the amount of moisture can be prevented by cooling the sheet P, and, as a result, the amount of moisture inside the sheet is enhanced to about 4.5 to 5%, and the height of the ripple in the end portion of the sheet in the width direction can be enhanced to about 0.5 to 0.8 mm.
Here, each one of the cooling rollers 201 and 301 may be a cooling roller 401 having the configuration illustrated in
In
Inside the cooling roller 401, a hollow portion used for causing cooling air to flow using the cooling fan 490 is formed, and a plurality of the heat pipes 402 holds the heat radiation fins 402a toward the cooling fan 490 side. As above, by arranging the heat pipes that are thermal uniformization members inside the cooling roller 401, for example, even in the case of continuous conveying sheets of the A4 size in the vertical direction, a temperature difference between the inside of the conveying area in the width direction of the cooling roller 401 and the outside of the area can decrease as much as possible. Accordingly, an advantage that it is further difficult to spoil the cooling performance can be expected.
Other than the above-described configuration, for example, a cooling roller 601 having the configuration as illustrated in
As illustrated in
Both end portions of the heat pipe roller 630, as illustrated in
As illustrated in
As described above, by forming a heat sink structure and using the cooling rollers 201 and 301 that can rotate together with the conveying of the cooling belts 202 and 302, the conveying resistance due to the friction with the cooling belts 202 and 302 can be markedly smaller than that of the fixing type. Accordingly, the cooling belts 202 and 302 and the sheet P can be stably conveyed, whereby the driving load and the power can be reduced.
In addition, the deterioration of the durability such as abrasion of the surfaces of the cooling rollers 201 and 301 due to sliding with the cooling belts 202 and 302 does hardly occurs, thereby heat transference between the surface of members such as the cooling rollers 201 and 301 and the cooling belts 202 and 302 is stabilized. Accordingly, the cooling performance and the reliability of the durability of the sheet cooling apparatus can be markedly improved.
As a result, for example, it is not particularly necessary to perform a surface treatment such as an alumite treatment for the surfaces of the cooling rollers 201 and 301, which are formed from aluminum, so as to reduce the abrasion and deterioration. In addition, similarly, it is not particularly necessary to perform a surface treatment having low frictional resistance using a fluororesin system or the like for the surfaces of the cooling rollers 201 and 301 so as to reduce the sliding resistance and the abrasion and deterioration. Accordingly, the heat transference between the surface of members such as the cooling rollers 201 and 301 and the cooling belts 202 and 302 is not degraded, and the component cost does not increase. Therefore, for example, it is possible to revive good heat radiation/cooling capability of an aluminum material or the like. In addition, there hardly is a decrease in the strength due to the progress of the abrasion/degradation of the surfaces of the cooling belts 202 and 302, and, for example, even in a case where a polyimide material is used, the thickness can be decreased, whereby the heat transference with the cooling rollers 201 and 301 can be improved.
In addition, as described above, by pressing the cooling rollers 201 and 301 that suspend the cooling belts 202 and 302 and pressing the cooling rollers 201 and 301 to opposing cooling rollers using the belt pressure roller, the shape of the conveying path is arranged to be bent in the shape of “S” as denoted by a thick line in
Furthermore, by using a curved path bent in the shape of “S” other than a cooling conveying path having an approximately linear shape, the miniaturization of the whole apparatus can be achieved, and the curl and the ripple can be reduced by acquiring a curl correction effect for the sheet.
A cooling apparatus 102 as a sheet cooling apparatus will be described with reference to
A cooling belt 702 as a second endless belt used for performing frictional conveying while being brought into contact with the rear face of the sheet P, a cooling roller 701, and belt pressure rollers 704 and 705 as second suspension members, and a tension roller 703 configure an independent cooling belt unit 700. The configuration of the cooling belt unit 700 is the same as that of the cooling belt unit 200 according to the above-described first embodiment, and thus, description thereof will not be presented.
A cooling belt 802 as a first endless belt performs frictional conveyance while being brought into contact with the front surface of the sheet P. This cooling belt 802, as illustrated in
The configuration of the cooling roller 801 is the same as that of the cooling roller 301 according to the first embodiment illustrated in
The belt pressure roller 803, as illustrated in
Between pressure spring bearing faces 810c and 820c integrally formed on the outer faces of the front side plate 810 and the rear side plate 820 and the pressure arms 812 and 822, pressure springs 814 and 824 of the compression coil type are inserted, and the pressure springs 814 and 824 bias the pressure arms 812 and 822 in a direction pushing them down. Accordingly, the belt pressure roller 803 supported by the pressure arms 812 and 822 is pressed to the opposing cooling roller 701 through the cooling belts 802 and 702.
On the outer faces of the front side plate 810 and the rear side plate 820, belt tensioners 815 and 825 used for applying tension to the cooling belt 802 are arranged. The belt tensioner 825 disposed on one side, as illustrated in
In addition, on the outer faces of the front side plate 810 and the rear side plate 820, tensioner holder supporting shafts 810f and 820f used for supporting the tensioner holders 816 and 826 to be swingable in directions Y1 and Y2 of arrows illustrated in
In other words, among a plurality of suspension members for suspending the cooling belt 802, the tension roller 804 located on the downstream in the conveying direction of the sheet is disposed to be movable so as to approach or be separated from the opposing cooling roller 701. In addition, by moving the tension roller 804, the nip length in the lowermost-stream portion in the contact range with the cooling belts 802 and 702 can be arbitrarily changed. This will be described more specifically.
As illustrated in
As illustrated in
When the cam driving motor 903 starts to rotate in the direction (clockwise direction) of an arrow X2 illustrated in
On the outer faces of the front side plate 810 and the rear side plate 820, spring hook pins 810e and 820e are integrally formed. On one ends of the tensioner holders 816 and 826, spring hook holes 816a and 826a are integrally formed. Pushing-up springs 906 and 907 of the pulling type can are hooked between the spring hook pins 810e and 820e and the spring hook holes 816a and 826a, and the tensioner holders 816 and 826 are biased so as to be pushed upwardly. Accordingly, the upper surfaces of the tensioner holders 816 and 826 contact the arc faces of the cams 901 and 905, as illustrated in
According to the configuration described above, the vertical positions of the tensioner holders 816 and 826 and the tension roller 804 supported to be rotatable by the tensioner holders 816 and 826 are controlled to be changed through the cams 901 and 905 by driving the cam driving motor 903 to rotate. The flow of control for lifting the tension roller 804 is illustrated in
As illustrated in
The state in which the tension roller 804 arrives at the upper limit position is illustrated in
As illustrated in
For example, there is a case where a photograph image or the like for which the amount of toner T get onto the upper surface of the sheet P is much more than that of the case of a text image or the like for which the amount of toner is small is fixed to thin paper, particularly having low mass and low strength. In such a case, the adhesion between the toner T and the surface layer of the fixing roller 110 is firm inside the fixing nip portion N, and there is a case where an upward curl that is opposite to a downward curl occurs until the sheet is detached from the surface layer of the fixing roller 110.
In addition, a cardboard or a coated sheet that receives more heat from the fixing device 100 than general plain paper having a weight of the sheet P of about 70 g to 80 g can easily maintain high temperature even after passing through the fixing device 100. In addition, even when the weights of the sheets are equivalent, and the temperatures of sheets P after passing through the fixing device 100 are equivalent, a sheet having low rigidity has internal moisture that can be easily extracted to the outside, and a ripple tends to be remarkable therein.
As above, the contact range of the cooling belts 702 and 802 illustrated in
When the cam driving motor 903 starts to rotate in a direction (the direction of arrow X1 illustrated in
At this time, as illustrated in
As above, after the cooling belts 702 and 802, as illustrated in
Similarly to the first embodiment, the cooling rollers 701 and 801 have hollow inner portions, and a plurality of heat radiation fins is formed in a hollow inner wall in the shape of a spiral so as to have a surface area larger than that of the pipe shape. As a result, the heat radiation effect is high.
In addition, by causing cooling air to flow in the hollow inner spaces of the cooling rollers 701 and 801 in accordance with the cooling fans 790 and 890, the heat radiation to the outside of the cooling apparatus 102 is promoted, which is the same as the first embodiment.
Furthermore, the advancement directions of the spirals of the heat radiation fins of the cooling rollers 701 and 801, as illustrated in
According to the configuration and the operation of the sheet cooling apparatus 102 described as above, in addition to the advantages of the above-described embodiments, the following advantages can be acquired. According to this embodiment, a nip length from the contact point C with the belt pressure roller 803 to the final the contact point D or D′ in the lowermost-stream portion of the contact range with the cooling belts 702 and 802 can be arbitrary selected (changed) in the range from an upper limit N1 to a lower limit N2. Accordingly, the correction for the ripple and the curl that is optimal in accordance with the weight, the size, the paper type, the installation environment, the fixing temperature, and the like of the sheet P can be performed.
In the above-described embodiment, while the printer has been described as an image forming apparatus as an example, the present invention is not limited thereto. For example, the image forming apparatus may be another image forming apparatus such as a copying machine or a facsimile apparatus or another image forming apparatus such as a multi-function apparatus combining the functions thereof. In addition, the image forming apparatus is not limited to an image forming apparatus in which an intermediate transfer member is used, and toner images carried in the intermediate transfer member are transferred to a sheet together. Thus, the image forming apparatus may be an image forming apparatus in which a sheet bearing member is used, and toner images of colors are sequentially transferred to a sheet carried in the sheet bearing member in an overlapping manner. By applying the present invention to a sheet cooling apparatus of such an image forming apparatus, the same advantages can be acquired.
In addition, in the above-described embodiment, while the first and second cooling rollers, the first and second endless belts, and the first and second suspension members have been described to respectively have the same configuration and the same material, the present invention is not limited thereto. For example, in order to correct the curl of the sheet, it may be configured such that one cooling roller has a hollow inner portion and has a plurality of the heat radiation fins formed on the hollow inner wall in the shape of a spiral, and the other cooling roller is formed as a solid metal bar having a diameter smaller than the diameter of the one cooling roller.
While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. The scope of the following claims is to be accorded the broadest interpretation so as to encompass all modifications, equivalent structures and functions.
This application claims the benefit of Japanese Patent Application No. 2012-166069, filed Jul. 26, 2012, which is hereby incorporated by reference herein in its entirety.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2012-166069 | Jul 2012 | JP | national |
| Number | Name | Date | Kind |
|---|---|---|---|
| 4064933 | Schuman | Dec 1977 | A |
| 5761535 | Neifert et al. | Jun 1998 | A |
| 7480480 | Endo et al. | Jan 2009 | B2 |
| 7489895 | Tani | Feb 2009 | B2 |
| 7505725 | Katayama et al. | Mar 2009 | B2 |
| 7546078 | Okuda et al. | Jun 2009 | B2 |
| 8554097 | Hara et al. | Oct 2013 | B2 |
| 20110318078 | Aoi | Dec 2011 | A1 |
| 20120074638 | Nakagaki | Mar 2012 | A1 |
| Number | Date | Country |
|---|---|---|
| S58-100056 | Jun 1983 | JP |
| 2004-145160 | May 2004 | JP |
| 2007-086282 | Apr 2007 | JP |
| 2008-265975 | Nov 2008 | JP |
| 2009161347 | Jul 2009 | JP |
| 2009175260 | Aug 2009 | JP |
| 4766054 | Sep 2011 | JP |
| 5086110 | Nov 2012 | JP |
| Number | Date | Country | |
|---|---|---|---|
| 20140029995 A1 | Jan 2014 | US |
