JP2009236953A - Image fixing/solidifying device and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress image quality deterioration due to a failure that an image on a recording material begins to be solidified before reaching a solidifying means, on a conveying means disposed between a heating means and the solidifying means. <P>SOLUTION: A fixing device 15 that generates heat, paper P and a toner image T heated by the fixing device 15 emit electromagnetic waves therearound. If going straight, the electromagnetic waves are transmitted to a cooling device 16, but, the waves are reflected by a shielding plate 81 of a reflector 18, then, the heat transmission is interrupted. The electromagnetic waves emitted from the paper P are reflected by the shielding plate 81, and the reflected electromagnetic waves are reflected by a counter reflection plate 82 again, then, transmitted to the paper P. Since the electromagnetic waves emitted from the fixing device 15 and the like are collected on the surface of the paper P in this manner, the toner image T carried on the surface of the paper P is warmed up, accordingly, the toner image is conveyed by the conveying device 17 to the cooling device 16 without causing solidification thereof. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an image fixing and solidifying device and an image forming apparatus.

For fixing an image on a recording material, a fixing device that heats and melts a toner image to fix the image on the recording material is used. The temperature of the toner image is relatively high even after the recording material is discharged from the fixing device, and the toner image is likely to be disturbed when the recording material receives an external force. Therefore, the recording material that has undergone the fixing process is cooled to solidify the toner image. There is. In Patent Document 1, a belt is stretched between a heating roller and a separation roller disposed on the downstream side of a first fixing unit that fixes a transfer material carrying an unfixed toner image. Two sets of belt units having cooling means are provided downstream of the contact portion between the heating roller and the belt and upstream from the contact portion between the separation roller and the belt, and the heating roller of each belt unit The transfer material heated by the first fixing unit in the second fixing unit configured so that the rollers and the separation rollers are pressed against each other via two belts is interposed between the belts pressed by the heating roller. There has been proposed a fixing device having a process of being clamped and conveyed and cooled in the process of being conveyed to the separation roller.
JP 2006-201657 A

  An object of the present invention is to suppress deterioration in image quality caused by an image on a recording material starting to solidify before reaching the solidifying means on a conveying means provided between the heating means and the solidifying means.

  In order to solve the above-described problems, an image fixing and solidifying apparatus according to claim 1 of the present invention is in contact with a recording material on which an image is formed, and heating means for heating the recording material, and is heated by the heating means. A conveying means for conveying the recording material, a reflecting means for reflecting the electromagnetic wave radiated from the heating means to the conveying means, and a solidifying means for solidifying the image of the recording material conveyed by the conveying means. Features.

According to a second aspect of the present invention, there is provided an image fixing and solidifying device according to the first aspect, wherein a plurality of the reflecting means are provided and electromagnetic waves are reflected between the plurality of reflecting means.
According to a third aspect of the present invention, in the image fixing and solidifying device according to the first aspect, the reflecting means is provided at a position facing the surface of the recording material conveyed by the conveying means. It is characterized by that.
According to a fourth aspect of the present invention, there is provided the image fixing and solidifying apparatus according to the first aspect, wherein the reflecting means is located between the heating means and the solidifying means, and the electromagnetic wave from the heating means to the solidifying means. It is also characterized by serving as a blocking means for blocking the transmission of.
According to a fifth aspect of the present invention, there is provided an image fixing and solidifying device according to the fourth aspect of the present invention, wherein the image fixing and solidifying device is provided on a surface of the reflecting means facing the solidifying means, and heat insulating means for cutting off heat transfer from the reflecting means. It is characterized by providing.
According to a sixth aspect of the present invention, in the image fixing and solidifying device according to any one of the first to fifth aspects, the conveying unit conveys the recording material in contact with a part of the recording material. And an air flow forming means for forming an air flow for bringing the recording material into close contact with the conveying belt.
An image fixing and solidifying apparatus according to a seventh aspect of the present invention is the image fixing and solidifying device according to the sixth aspect, wherein the conveying unit is a surface opposite to a surface on which an image of a recording material heated by the heating unit is formed. The recording material is conveyed in contact with the recording medium.
According to an eighth aspect of the present invention, there is provided an image fixing and solidifying apparatus according to any one of the first to seventh aspects, further comprising suction means for sucking vapor generated from the recording material conveyed by the conveying means. It is characterized by.
An image fixing and solidifying apparatus according to a ninth aspect of the present invention is the image fixing and solidifying device according to any one of the first to eighth aspects, wherein the solidifying means is in contact with at least a surface side on which an image of the recording material is formed. It is the cooling means which cools.
An image fixing and solidifying apparatus according to a tenth aspect of the present invention is the image fixing and solidifying device according to the ninth aspect, wherein the cooling means is stretched by at least a plurality of rolls and is circulated to form an image of the recording material. It has the 1st conveyance belt which contacts the side and conveys a recording material, It is characterized by the above-mentioned.
An image fixing and solidifying apparatus according to an eleventh aspect of the present invention is the image fixing and solidifying device according to the tenth aspect, wherein the cooling unit is stretched by a plurality of rolls and circulates so as to sandwich the recording material together with the first conveying belt. In contact with the inner peripheral surface of the first conveying belt in a section where the recording material is nipped and conveyed by the second conveying belt to be conveyed, the first conveying belt, and the second conveying belt, the first conveying belt is cooled. And a cooling body.
An image fixing and solidifying apparatus according to a twelfth aspect of the present invention is the image fixing and solidifying device according to any one of the first to eleventh aspects, wherein the image formed on the recording material is composed of an amorphous resin and a crystalline resin. The temperature when the image on the recording material is kept warm by the electromagnetic wave reflected by the reflecting means and the recording material is in contact with the cooling means is the glass transition temperature of the amorphous resin. The cooling means cools the glass transition temperature to a temperature lower than the glass transition temperature of the amorphous resin and the melting point of the crystalline resin.
According to a thirteenth aspect of the present invention, an image forming apparatus includes an image forming unit that forms an image on a recording material and the above-described image fixing and solidifying device.

According to the image fixing and solidifying apparatus of the first aspect, the image quality caused by the image on the recording material starting to solidify before reaching the solidifying means on the conveying means provided between the heating means and the solidifying means. The decrease can be suppressed.
According to the image fixing and solidifying device of the second aspect, it is possible to increase the electromagnetic wave reflected to the conveying unit as compared with the case where the present configuration is not provided.
According to the image fixing and solidifying apparatus of the third aspect, the electromagnetic wave reflected to the conveying unit can be increased as compared with the case where the present configuration is not provided.
According to the image fixing and solidifying apparatus of the fourth aspect, it is possible to suppress a decrease in the capability of the solidifying means due to the electromagnetic waves radiated from the heating means warming the solidifying means.
According to the image fixing and solidifying device of the fifth aspect, it is possible to suppress a decrease in the capability of the solidifying means due to the electromagnetic waves radiated from the reflecting means warming the solidifying device.
According to the image fixing and solidifying apparatus of the sixth aspect, the recording material discharged from the heating unit is brought into close contact with the conveying unit when the heating unit and the solidifying unit are separated as compared with the case where the present configuration is not provided. Therefore, the transferability to the solidifying means is improved.
According to the image fixing and solidifying apparatus of the seventh aspect, the image on the recording material heated by the heating unit is prevented from being disturbed before reaching the solidifying unit.
According to the image fixing and solidifying device of the eighth aspect, the trouble caused by the water vapor generated from the recording material due to the heating by the heating means is suppressed as compared with the case where the present configuration is not provided.
According to the image fixing and solidifying device of the ninth aspect, when the heated surface is cooled, the vapor generated by the heating before the contact can be released from the recording paper even if the surface is directly contacted. Therefore, image quality defects such as toner image disturbance caused by vapor remaining in the recording paper can be suppressed, and a cooling effect can be obtained by direct contact.
According to the image fixing and solidifying device of the tenth aspect, the image can be smoothed as compared with the case where the present configuration is not provided.
According to the image fixing and solidifying device of the eleventh aspect of the present invention, compared with the case where the present configuration is not provided, the adhesion between the recording material and the cooling means is improved and the ability to cool the recording material is improved.
According to the image fixing and solidifying apparatus of the twelfth aspect, solidification can be suppressed from partially starting when an image containing components having different temperatures at the time of solidification is solidified.
According to the image forming apparatus of the thirteenth aspect, an image can be formed on the recording material and fixed and solidified.

Embodiments of the present invention will be described below with reference to the drawings.
[A. Embodiment]
[A-1. Configuration of image forming apparatus]
FIG. 1 is a diagram illustrating a configuration of an image forming apparatus 1 in which an image fixing and solidifying apparatus and an image forming apparatus according to the present embodiment are integrally configured. As shown in the figure, the image forming apparatus 1 includes a paper storage unit 12, image forming units 13Y, 13M, 13C, and 13K, a transfer device 14, a fixing device 15, a cooling device 16, and a conveying device 17. The reflection device 18 is provided. Each of these components is controlled by a control unit (not shown). The control unit includes a CPU (Central Processing Unit), a memory, and the like, and controls the entire image forming apparatus 1 by the CPU executing a program stored in the memory. Note that the symbols Y, M, C, and K indicate configurations corresponding to yellow, magenta, cyan, and black toners, respectively.
The paper storage unit 12 stores paper cut into a predetermined size such as A3 or A4. The sheets stored in the sheet storage unit 12 are taken out one by one in accordance with an instruction from the control unit, and are conveyed to the transfer device 14 via the sheet conveyance path.

  Each of the image forming units 13Y, 13M, 13C, and 13K includes a photosensitive drum, a charging unit, an exposure unit, a developing unit, a primary transfer roll, and a cleaning member, and a toner corresponding to image data using corresponding toner. An image is formed and transferred onto the intermediate transfer belt 41 in an overlapping manner. This image data may be obtained by reading an original image by an image reading device (not shown) or may be generated based on data transmitted from a computer device (not shown). The transfer device 14 includes an intermediate transfer belt 41, a secondary transfer roll 42, and an opposing roll 43 that faces the secondary transfer roll 42 with the intermediate transfer belt 41 interposed therebetween, and image forming units 13Y, 13M, and 13C. , 13K, transfer means for transferring the toner image formed on the paper. The intermediate transfer belt 41 is rotated in the direction A in the drawing by a driving roll (not shown). When the toner images are transferred in an overlapping manner by the image forming units 13Y, 13M, 13C, and 13K, the toner images are transferred to the intermediate transfer belt 41. It is conveyed to the position of the next transfer roll 42 and the opposing roll 43. The secondary transfer roll 42 transfers the toner image on the intermediate transfer belt 41 to the paper conveyed from the paper storage unit 12 by the potential difference with the intermediate transfer belt 41. The sheet on which the toner image is transferred is sent to the fixing device 15.

[A-2. Material constituting the image]
In this embodiment, low-melting toner is used as an image. This low melting point toner has a lower melting point temperature than conventional toners in order to reduce power consumption during fixing for energy saving. This low-melting-point toner is a crystalline resin that melts at a low temperature inside the toner surface with a non-crystalline resin core surface that melts at a high temperature in order to achieve both storage at room temperature and low-temperature fixing at the time of fixing. The core / shell structure is configured to achieve both storage and fixing characteristics.
Here, the amorphous resin and the crystalline resin will be described.

[A-2-1. Amorphous resin]
Amorphous resin is not a clear endothermic peak but a stepwise endothermic change in thermal analysis using differential scanning calorimetry (DSC). A material that is thermoplasticized at a temperature equal to or higher than the transition temperature.

  The weight average molecular weight (Mw) of the amorphous resin is preferably in the range of 5,000 to 100,000, and preferably in the range of 15,000 to 85,000. If the molecular weight is lower than 5000, the hot offset resistance may be deteriorated, and if it is greater than 100,000, the toner granulation property and shape controllability may be deteriorated. Furthermore, the amount of the dissociating group-containing component in the binder resin is preferably 2% by mass or less. If it is larger than this, the shape controllability is impaired. In addition, as a dissociation group containing component amount, More preferably, it is the range of 0.25-1.75 mass%, More preferably, it is the range of 0.5-1.5 mass%.

  The glass transition temperature of the amorphous resin is preferably in the range of 45 to 80 ° C, and more preferably in the range of 50 to 70 ° C. When the glass transition temperature is less than 45 ° C., the toner tends to easily block during storage or in the developing device (a phenomenon in which toner particles are aggregated into a lump). On the other hand, when the glass transition temperature exceeds 80 ° C., the fixing temperature of the toner becomes high.

[A-2-2. Crystalline resin]
The crystalline resin refers to a resin having a clear endothermic peak instead of a stepwise endothermic amount change in differential scanning calorimetry (DSC).
The crystalline resin is not particularly limited as long as it is a crystalline resin, and specific examples include crystalline polyester resins and crystalline vinyl resins. From the viewpoint of adjusting the melting point within a preferable range, a crystalline polyester resin is preferable. A linear aliphatic crystalline polyester resin having an appropriate melting point is more preferable.

  The crystalline polyester resin is synthesized from an acid (dicarboxylic acid) component and an alcohol (diol) component. In the present invention, a copolymer obtained by copolymerizing other components in a proportion of 50% by mass or less with respect to the crystalline polyester main chain is also referred to as a crystalline polyester resin.

  The melting point of the crystalline resin is preferably 40 ° C. or higher, and more preferably 60 ° C. or higher. However, as an upper limit, 100 degrees C or less is preferable and 90 degrees C or less is more preferable. In particular, the melting point of the crystalline resin is preferably in the range of 60 to 95 ° C. for low temperature fixability. When the melting point of the crystalline resin is lower than 40 ° C., the toner may be blocked during storage or use of the toner. In addition, when the melting point of the crystalline resin is higher than 100 ° C., it may take time for the particle formation or the particle size distribution may be expanded, and the image quality may be deteriorated.

  The molecular weight of the crystalline resin is not particularly limited, but the weight average molecular weight is preferably 8000 or more, and more preferably 10,000 or more. However, it is preferably 100,000 or less, and more preferably 70000 or less. If the weight average molecular weight of the crystalline resin is less than 8000, there is a risk that the strength of the fixed image will be insufficient, or crushing may occur while stirring the developing device. Further, if the weight average molecular weight of the crystalline resin is larger than 100,000, the fixing temperature may be increased.

  In addition to the above-described amorphous resin and crystalline resin, known additives such as a colorant, a release agent, and a charge control agent are added to the toner.

Here, when the paper cools after passing through the fixing device, solidification of the toner starts.At this time, if the gradient of the temperature change near the softening temperature and the melting temperature is gentle, the amorphous resin that melts at a high temperature Since the crystalline resin that melts at a low temperature contains substances different in solidification state depending on the temperature, the crystallization may start partially, and the toner image may be uneven. Therefore, in this embodiment, a toner containing two components having a glass transition temperature of amorphous resin of 65 ° C. and a melting point of crystalline resin of 80 ° C. is adopted, and the toner enters the cooling device by air heated by the fixing device. The paper is kept at 90 ° C. or more, cooled by a cooling device with a temperature gradient steeper than that of natural cooling, and cooled so that the temperature of the paper decreases to 60 ° C.
For example, compared with the case where the fixing device temperature is set high in order to keep the temperature at the time of contacting the cooling device above the melting point and the softening point without being heated by the air heated by the fixing device, it is consumed in this embodiment. Power is suppressed.

[A-3. Configuration of Fixing Device, Cooling Device, Conveying Device, and Reflecting Device]
FIG. 2 is a diagram for explaining the fixing device 15, the cooling device 16, the conveying device 17, and the reflecting device 18. In the present embodiment, the fixing device 15 is used as the heating unit that contacts the paper on which the toner image is formed by the above-described image forming unit and heats the paper. Specifically, the fixing device 15 includes a heating roll 51 and a pressure roll 52, and applies heat and pressure to the sheet conveyed from the secondary transfer roll 42 to generate a toner image held on the surface thereof. It is melted and fixed on the paper. The heating roll 51 has a heat source 511 such as a halogen lamp inside, and heats the surface of the paper to about 90 degrees. The pressure roll 52 is pressed against the heating roll 51 and applies pressure to the sheet passing between the heating roll 51 and the pressure roll 52. Further, a peeling member 53 made of metal or resin is provided near the surface of the heating roll 51. The paper that has undergone the fixing process by applying heat and pressure by the heating roll 51 and the pressure roll 52 is peeled off from the heating roll 51 by the peeling member 53 and conveyed to the cooling apparatus 16 by the conveying device 17. It has become.

  Further, the transport device 17 is used as the transport means in the present embodiment. The transport device 17 is provided between the fixing device 15 and the cooling device 16. Here, generally, when the distance between the fixing device and the cooling device is taken in this way, there are cases where it is convenient in layout with other components, or the image of the cooling device is cooled by the influence of heat generated by the fixing device. In some cases, the reduction in the effect is suppressed, or image quality defects such as image distortion due to water vapor generated by heating the recording material and the image are suppressed from appearing on the recording material. In particular, the above-described image quality defect due to water vapor is likely to appear when a paper sheet in a state where water vapor is generated is pinched by a belt or the like to eliminate the escape space of the water vapor.

  The transport device 17 includes transport rollers 71 a and 71 b (hereinafter simply referred to as a transport roller 71 when not distinguished from each other) and a transport belt 72, and transports the sheet discharged from the fixing device 15 to the cooling device 16. The transport rolls 71a and 71b are rolls that support the transport belt 72, and at least one of them is rotated by a drive unit (not shown). The conveyance belt 72 is an endless belt member that is wound around the conveyance roll 71, and carries the sheet peeled from the heating roll 51 by the above-described peeling member 53 and conveys it to the cooling device 16. At this time, the conveyance device 17 conveys the sheet in contact with the surface opposite to the surface on which the toner image is formed.

  When transporting normal paper, a configuration in which a pair of rolls transports is used in addition to the configuration in which transport is performed by a belt as described above. In general, a roll in a pair of rolls is a system in which a plurality of rubbers or the like are attached to a rotating shaft and a part of a sheet is contacted. This is because, for example, if it is made of rubber or the like that contacts all of the paper, it is inferior in terms of transportability or costs for parts compared to a case where it is in contact with a part. However, when running on a sheet on which a melted toner image is formed, the toner image may become uneven due to, for example, the low temperature of the rubber or irregularities on the roll surface due to contact with a part of the paper. .

  Here, the conveying belt 72 of the conveying device 17 conveys the sheet in contact with the surface opposite to the surface on which the toner image is formed, that is, the rear surface of the sheet. It is desirable to adhere as much as possible.

FIG. 3 is a schematic diagram illustrating an example of the transport device 17.
For example, in the case of the transport apparatus shown in FIG. 3A, a plurality of thin transport belts are arranged in parallel with the transport direction of the paper, and the paper is transported by these transport belts. A fan 73 is used as the air flow forming means in this embodiment. As shown in FIG. 2, the fan 73 is disposed on the back side of the surface on which the transport device transports the paper, and sucks air. The air between the back surface of the paper and each belt is sucked through the gap between the respective conveyor belts and then exhausted outside the system. In this way, the air pressure on the back side of the paper is more negative than the air pressure on the front side of the paper, so that each conveyor belt and the back side of the paper are in close contact.
3B is a belt having a plurality of holes in the belt surface of the conveyor belt. In this case as well, the air on the back side of the paper is similarly sucked to form an air flow for bringing the paper into close contact with the transport device, and the sucked air passes through the plurality of holes and goes out of the system. Discharged.

Although these conveyance apparatuses illustrated here adsorb | suck a sheet | seat to a conveyance apparatus by attracting | sucking air, since it is necessary to attract | suck the air between a paper back surface and the surface of the conveyance apparatus side which mounts this, conveyance The surface on the apparatus side conveys the sheet in contact with only a part of the back surface of the sheet, not the entire sheet. For example, in FIG. 3B, when the cross section of the conveyor belt indicated by the broken line is viewed from the direction of the arrow V, the contact surface S of each belt is in contact with a part of the back side of the sheet as shown in FIG. That is.
In the following description, the conveyance belt 72 will be described as a conveyance belt having a plurality of holes in the belt surface as shown in FIG.

  Returning to FIG. 2, the description will be continued. In the present embodiment, the cooling device 16 is used as the solidifying means. The cooling device 16 is a solidifying means for cooling and solidifying the toner image that has been melted by the fixing device 15. The cooling device 16 includes a plurality of first transport rollers 61, a first transport belt 62, a plurality of second transport rollers 63, a second transport belt 64, and a heat sink 66 used as a cooling body in the present embodiment. And.

  The plurality of first transport rolls 61 are rolls that support the first transport belt 62, and at least one of these rolls is rotated by a drive unit (not shown). The first conveyor belt 62 is a first endless belt member that is wound around the plurality of first conveyor rolls 61 and the heat sink 66, and moves around in accordance with the rotation of the first conveyor roll 61. The plurality of second transport rolls 63 are rolls that support the second transport belt 64. The second conveyor belt 64 is a second endless belt member that is wound around the plurality of second conveyor rollers 63, and moves around in the direction of arrow B in the drawing along with the first conveyor belt 62. The surface of the first conveying belt 62 is smooth, and the toner image on the sheet that has been in a molten state before coming into contact with the first conveying belt 62 comes into contact with the first conveying belt 62 and becomes highly glossy. As another form, both the first conveyance roll 61 and the second conveyance roll 63 may be driven, and conversely, the first conveyance belt 62 may be rotated along with the second conveyance belt 64. The paper on which the toner image is fixed by the fixing device 15 described above is transported on the transport belt 72 of the transport device 17, and the leading end of the paper is abutted against the first transport belt 62. Thereafter, the sheet is sandwiched between the first conveying belt 62 and the second conveying belt 64, and is conveyed in the conveying direction C of the sheet in the drawing according to the circular movement.

  The heat sink 66 is provided on the inner peripheral side of the first transport belt 62 so as to contact the inner peripheral surface, and cools the first transport belt 62. The heat sink 66 includes a base that is in contact with the inner peripheral surface of the first conveyor belt 62, a large number of fins provided substantially perpendicular to the longitudinal direction of the base, a case that covers the base and the fins, and the image forming apparatus 1. And two motors (not shown) as a drive source for rotating these rotary fans. The base and fins are made of aluminum having good thermal conductivity, and the base absorbs heat transmitted from the paper through the first conveying belt 62, and the fins release the heat. This fin increases the surface area of the heat sink 66 in contact with the air and increases the efficiency of diffusing the heat absorbed by the base into the air. The heated air in the cooling device 16 is discharged to the outside of the image forming apparatus 1 by rotating rotating fins. In this way, the cooling device 16 takes heat from the sheet and cools the sheet. Thus, if the adhesion between the cooling device and the sheet is increased, the efficiency of cooling the sheet is improved. Moreover, by comprising with a belt and a heat sink, the cooling time closely_contact | adhered to the cooling body in the space limited, for example compared with the case where it cools with a cooling roll becomes long.

  In this embodiment, the paper conveyance speed is set to be high, and the speed is assumed to be that after passing through the fixing device, the paper is discharged from the image forming apparatus without cooling and stacked on the discharge tray. The speed is such that the next paper is discharged before the temperature of the toner image on the paper stacked on the paper discharge tray is lowered, and the toner adheres to the back surface of the next discharged paper. When the conveyance speed is decreased and the productivity is lowered, the adhesion of toner between the sheets stacked on the paper discharge tray is reduced.

  The reflection device 18 includes a blocking plate 81 used as a blocking unit, which is one of the reflecting units in the present embodiment, and an opposing reflecting plate used as a reflecting unit facing the recording material conveyed by the conveying unit in the present embodiment. 82. The blocking plate 81 is a flat plate having a width equal to or greater than the maximum sheet width that can be conveyed in a direction orthogonal to the sheet conveyance direction (the depth direction of the sheet). Specifically, the blocking plate 81 is a flat plate in which an aluminum foil having a high reflectance is pasted on the surface of a resin heat insulating material, and is disposed in the vicinity of the cooling device 16 so as to fix the fixing device 15 or heated paper. By reflecting the electromagnetic wave radiated from the surface of the steel plate with the above-mentioned aluminum foil, the electromagnetic wave is blocked from being transmitted to the cooling device 16 and reflected in the vicinity of the conveying device 17. Similar to the blocking plate 81, the counter reflecting plate 82 has a width that is equal to or larger than the maximum sheet width that can be conveyed in a direction orthogonal to the sheet conveyance direction (the depth direction of the sheet surface). And the conveying device 17 is disposed so as to face the conveying surface for conveying the sheet. The counter reflector 82 is also a flat plate in which an aluminum foil having a high reflectance is attached to the surface of a resin heat insulating material.

FIG. 4 is a diagram for explaining that heat is transmitted to the paper transported by the transport device 17 by heat radiation from the reflection device 18. The heat of the fixing device 15 that generates heat and the paper P and the toner image T heated by the fixing device 15 are conveyed to the surroundings as electromagnetic waves. These electromagnetic waves indicated by broken lines in FIG. 4A are mainly transmitted to the cooling device 16 when proceeding straight as they are, but transfer of heat to the cooling device 16 by being reflected by the blocking plate 81 of the reflecting device 18. Is to be blocked. As shown in FIG. 4B, the electromagnetic wave from the paper P is mainly reflected by the blocking plate 81, and the reflected electromagnetic wave that travels in the direction of the counter reflecting plate 82 is the counter reflecting plate. Re-reflected by 82 and transmitted to the paper P. Note that the electromagnetic waves radiated from the fixing device 15 and the paper P may be directly reflected by the blocking plate 81 or the counter reflector 82 and transmitted to the paper P.
As described above, since the electromagnetic waves radiated from the fixing device 15 and the like are collected on the surface of the paper P being transported by the transport device 17, the toner image T held on the surface of the paper P is warmed. The image is conveyed to the cooling device 16 by the conveying device 17 without solidifying.

In addition, when the image forming apparatus is initially driven, the transport device 17 is often at substantially the same temperature as the environmental temperature. In this case, the temperature of the transport device 17 may be lower than the temperature of the paper heated by the fixing device 15, and the toner image on the paper may be solidified during the transport of the paper. In the present embodiment, electromagnetic waves reflected from the fixing device 15 during preheating in the fixing device 15 are collected on the conveying surface of the conveying device 17 and warm the outer peripheral surface of the conveying belt 72 of the conveying device 17. When the paper is allowed to pass through 17, the toner image is hardly solidified as described above.
Further, in the case of a transport device that closes the sheet by sucking air, as shown in FIG. 3C, only a part of the back surface of the sheet is in contact with the transport device during transport. The temperature difference between the paper portion in contact with the conveyance device and the paper portion not in contact with the conveyance device increases, and there is a possibility that unevenness occurs in solidification of the toner image on the entire paper. In the present embodiment, electromagnetic waves radiated from the fixing device 15 are collected on the transport surface of the transport device 17 to warm the outer peripheral surface of the transport belt 72 of the transport device 17 and also warm the air around the transport device 17. When the paper is transported by the transport device 17, the toner image unevenness as described above hardly occurs.

  3 (d) and 3 (e) show a case where a sheet is run with the configuration of the present embodiment (FIG. 3 (d)) when the transport apparatus as shown in FIG. 3 (b) is used. As a comparison, it is a view when the sheet is run with two configurations, that is, when the shielding plate and the counter-reflection plate are covered with a cover with low reflectance and the reflectance is lowered (FIG. 3E). Here, in FIG. 3E, compared with FIG. 3D, the unevenness of the toner image on the paper is stronger in the portion that is not in contact with the conveying device 17 and in the portion that is not in contact therewith. This unevenness was confirmed after passing through the conveying device and before entering the cooling device and after passing through the cooling device.

[B. Modified example]
The embodiment described above may be modified as in the following example. Moreover, you may combine these modifications suitably.
(1) In the embodiment described above, the blocking plate 81 and the counter reflecting plate 82 are flat plates, but the blocking plate 81 and the counter reflecting plate 82 are not limited to flat plates. For example, it may be bent near the transport device 17. FIG. 5 is a diagram illustrating an example of the blocking plate 81 having a bent shape. A sheet often used as a recording material contains moisture, and the moisture may evaporate and generate water vapor in a fixing process. In this case, the water vapor condenses inside the housing of the image forming apparatus, causing condensation, and falls to a toner image formed on the surface of the recording material, which may disturb the image quality. As shown in FIG. 5, there is a dew condensation water receiving portion 811 formed at the front end of the blocking plate 81 by being bent toward the upstream side in the transport direction. If it does in this way, the dew condensation water receiving part 811 will receive the moisture which falls. In addition, on the near side or the far side in FIG. 5, a discharge port for discharging the received moisture may be provided at a position away from the sheet to be conveyed. Further, in the present embodiment, the receiving means is configured by bending a part of the shielding plate, but it may be provided anywhere on the shielding plate instead of the end, or another plate may be provided on the shielding plate, or on the opposing reflecting plate. It may be provided. In addition, by increasing the temperature of the space that transports the heated paper that is likely to generate water vapor by reflected heat as in this embodiment, the amount of saturated water vapor in the space increases, and dew condensation compared to when the temperature is low. Is suppressed.

(2) In the above-described embodiment, the blocking plate 81 is a single flat plate and only extends upward, but the number and shape of the plates constituting the blocking plate 81 are not limited thereto. For example, the blocking plate 81 formed of a plurality of plates may be provided, and the shape thereof may be a shape that surrounds the fixing device 15 and the conveying device 17.

  In the above-described embodiment, the air warmed by the fixing device 15 is not specifically described about discharging outside the system. However, the air flow path is formed so that the air heated by the fixing device 15 is discharged outside the system. Means may be provided.

  FIG. 6 is a view showing the reflecting device 18 in the present embodiment having a shape surrounding the fixing device 15 and the conveying device 17 and a duct 19 surrounding the periphery thereof. FIG. 7 is a view showing the fixing device 15, the reflecting device 18, and the duct 19 when the cross section U shown by the alternate long and short dash line in FIG. 6 is viewed from the direction of the arrow V parallel to the conveyance direction. Here, the blocking plate 81 includes two surfaces parallel to the paper conveyance direction, and is configured to cover the fixing device 15, the conveyance device 17, and the conveyance path of the paper P passing through them. As a result, as indicated by the arrow in the figure, the electromagnetic wave of heat from the fixing device 15 is reflected by the blocking plate 81 and hardly transmitted to the outside, and warms the air around the fixing device 15 and the conveying device 17. As a result, the fixing device 15 is kept warm and energy consumption by the fixing device 15 is suppressed. Further, by including two surfaces parallel to the transport direction, the entire area of the paper is warmed up evenly compared to the case without this configuration.

Moreover, the duct 19 was used as a heat insulation means in this modification. The duct 19 includes an outer wall 91 and an exhaust fan 92. The outer wall 91 is a member having the same width as that of the blocking plate 81 in a direction orthogonal to the sheet conveyance direction (the depth direction of the sheet), and a cross section of the outer wall 91 has a “U” shape. That is, a cylindrical duct 19 is formed by such a “U” -shaped outer wall 91 and the blocking plate 81, and openings are respectively provided at two lower ends of the duct 19. become. Since these openings are directed inward, that is, toward the fixing device 15, a larger amount of air heated by heating the fixing device 15 flows than cool air outside the outer wall 91. The arrow line D1 and the arrow line D2 of FIG. 6 have shown the air flow path through which this air flows. In particular, since the air flow path indicated by the arrow D1 is along the surface of the sheet P after fixing and the toner image T held on the surface, the air heated by the heating of the fixing device 15 is the air. By passing through the flow path, the toner image T conveyed by the conveying device 17 is heated. Moreover, as shown in FIG. 6, since air flows inside the duct 19, the transfer of heat to the cooling device side is cut as compared with the case where this configuration is not provided. Thereby, the circumference | surroundings of a cooling device are insulated and the energy consumption by a cooling device is suppressed.
The exhaust fan 92 also functions as a suction means in this modification. In this modification, the duct 19 is used as the heat insulating means. However, the heat insulating means is not limited to this, and a heat insulating material having a heat insulating effect may be attached.
In FIG. 6, the ducts are configured to form the air flow paths at the upstream and downstream sides of D1 and D2 and the fixing device, but the ducts may be configured to have only the D1 side and no D2 side duct.

(3) In the above-described embodiment, the fixing device 15 includes the heating roll 51 and the pressure roll 52, but the configuration of the fixing device 15 is not limited thereto. For example, the fixing device 15 may include a heating roll 51 and a pressure belt. The pressure belt is composed of, for example, a belt member and a pressure pad. When the pressure pad presses the belt member against the heating roll 51, pressure is applied to the paper passing between the heating roll 51 and the pressure belt. May be added.

(4) In the above-described embodiment, the heat sink 66 is provided along the inner peripheral surface on the inner peripheral side of the first transport belt 62, but the inner periphery on the inner peripheral side of the second transport belt 64. It may be provided along the surface, or may be provided on both the inner peripheral side of the first transport belt 62 and the inner peripheral side of the second transport belt 64. Further, a belt that contacts only one side of the recording material may be used. In the embodiment, the heat sink 66 is used as the cooling body. However, this may be any device that cools recording materials such as paper. For example, a fan or a refrigerant may be used. Good. Further, it is sufficient that the recording material can be cooled without providing the heat sink 66 or the like. In this case, for example, the first conveyance belt 62 and the second conveyance belt 64 may be used which are long enough to sufficiently spread the heat during the nipping conveyance and to cool the recording material. Further, it may be cooled by cooling air that is not contacted and cooled without contact, but cooled without contact.

(5) In the above-described embodiment, a sheet cut to a predetermined size such as A3 or A4 is used as the recording material. Roll-shaped paper may be used.

(6) In the above-described embodiment, the transport device 17 that closes the paper to the transport surface of the transport device 17 by sucking the ambient air on the back surface of the paper is used. Not limited. For example, as a means for bringing the paper into close contact with the transport device, a transport device that brings the paper into close contact with an electrostatic adsorption force may be used, or a guide that induces natural fall of the paper may be used.

(7) The blocking plate 81 and the counter reflecting plate 82 in the above-described embodiment are flat plates in which an aluminum foil having a high emissivity is pasted on the surface of a resin heat insulating material. However, other materials may be used. For example, a metal flat plate such as a steel plate whose surface is polished may be used, or a resin flat plate subjected to metal plating may be used.
In the above-described embodiment, the number of the counter reflecting plates 82 is one, but a plurality of counter reflecting plates 82 may exist.
In the embodiment described above, the reflecting means is configured by combining flat plates, but may be configured by using a plate having a curved surface. In particular, since the directions of electromagnetic waves from the fixing device 15 and the like can be known in advance from the arrangement of the fixing device 15 and the conveying device 17, the reflecting means obtains these directions in advance, and the electromagnetic waves are efficiently obtained after the fixing process P or It may be designed by calculating a shape to be collected on the surface of the conveying means.

(8) In the above-described embodiment, the image forming apparatus is used. However, an image fixing and solidifying apparatus that heats and cools the toner image on the sheet using a sheet on which an image has already been formed may be provided individually. . In that case, image fixing and solidification may be performed using a paper on which an unfixed toner image is formed, or image fixing and solidification may be performed using a paper once fixed with toner. Here, a case where a sheet on which toner is once fixed is used will be described. The paper on which the toner image has been fixed once by an image forming apparatus (not shown), for example, is melted again by the fixing device of the image fixing and solidifying device shown in FIG. Glossy and discharged. Since the image fixing and solidifying device performs heating and cooling, the power consumption increases. For this reason, if the image fixing and solidifying device is formed integrally with the image forming unit, the power required for one device may increase and it may be difficult to supply it. In this way, these are configured separately. As a result, the power consumption required for each device is suppressed as compared with a case where the devices are integrated.

(9) In the above-described embodiment, Y, M, C, and K toners are used. However, transparent toner and foamed toner may be used. In particular, when transparent toner or foamed toner is further used for normal Y, M, C, and K images, the thickness of the image may increase, and the toner may be difficult to melt. In such a case, it is desirable to make the toner easier to melt by setting the heating time longer than when using normal Y, M, C, and K toners. When a plurality of toners are used, the difference in softening temperature at which the individual toners melt may increase. In such a case, the heating temperature of the toner image is kept higher than the solidification temperature (for example, the melting temperature or the softening temperature) of all these toners, and is cooled to a state lower than the solidification temperature of all these toners at once. Is desirable. Coated paper may be used as the paper. In that case, it is desirable to keep the temperature of the coated paper at a temperature at which the toner easily enters the coating layer until reaching the solidifying device, and solidify by the solidifying device.

(10) In addition to the above-described embodiment, a temperature measurement unit that measures the temperature of the space between the fixing device and the reflection device, and a temperature adjustment unit that adjusts the temperature based on the measurement by the temperature measurement unit, The temperature may be adjusted when the temperature becomes too high or too low due to reflection of heat radiation. The temperature adjusting means may be configured to generate an air flow, or a reflection blocking film that blocks reflection of electromagnetic waves to enter and exit so as to block between the reflecting means and the fixing device. Further, in such temperature adjustment, the control unit performs feedback control of the heat generation amount of the heat source 511, the conveyance speed of the conveyance device 17, the rotation speed of the rotating fan of the heat sink 66, and the like based on the measurement by the temperature measurement unit described above. Or may be performed by controlling these based on setting values obtained by numerical calculation from the arrangement and physical property values of each device and recording material.

1 is a diagram illustrating a configuration of an image forming apparatus according to an exemplary embodiment. It is a figure for demonstrating a fixing device, a cooling device, a conveying apparatus, and a reflecting device. It is the schematic which showed the example of the paper after passing a conveying apparatus and a conveying apparatus. It is a figure explaining reflection of the thermal radiation by a reflecting device. It is a figure which shows an example of a shielding board. FIG. 6 is a diagram illustrating a reflection device having a shape surrounding a fixing device and a conveyance device, and a duct surrounding the reflection device. FIG. 4 is a diagram illustrating a fixing device, a reflection device, and a duct when viewed from a direction parallel to a conveyance direction.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Image forming apparatus, 12 ... Paper accommodating part, 14 ... Transfer device, 15 ... Fixing device, 16 ... Cooling device, 17 ... Conveying device, 18 ... Reflecting device, 19 ... Duct, 41 ... Intermediate transfer belt, 42 ... Two Next transfer roll, 43 ... opposite roll, 51 ... heating roll, 511 ... heat source, 52 ... pressure roll, 53 ... peeling member, 61 ... first transport roll, 62 ... first transport belt, 63 ... second transport roll, 64 ... second conveying belt, 66 ... heat sink, 71 ... conveying roll, 72 ... conveying belt, 81 ... blocking plate, 811 ... condensed water receiving portion, 82 ... opposite reflecting plate, 91 ... outer wall, 92 ... exhaust fan, C ... transport direction, D1, D2 ... air flow path, P ... paper, S ... contact surface, T ... toner image.

Claims (13)

Heating means for contacting the recording material on which an image is formed and heating the recording material;
Conveying means for conveying the recording material heated by the heating means;
Reflecting means for reflecting the electromagnetic wave radiated from the heating means to the conveying means;
An image fixing and solidifying apparatus comprising: a solidifying unit that solidifies an image of the recording material conveyed by the conveying unit.   2. The image fixing and solidifying apparatus according to claim 1, wherein a plurality of the reflection means are provided, and electromagnetic waves are reflected between the plurality of reflection means.   The image fixing and solidifying apparatus according to claim 1, wherein the reflection unit is provided at a position facing a surface of the recording material conveyed by the conveyance unit.   2. The image fixing according to claim 1, wherein the reflection unit also serves as a blocking unit that is between the heating unit and the solidifying unit and blocks transmission of electromagnetic waves from the heating unit to the solidifying unit. Solidification equipment.   The image fixing and solidifying apparatus according to claim 4, further comprising a heat insulating unit that is provided on a surface of the reflecting unit that faces the solidifying unit and blocks heat from being transmitted from the reflecting unit. The transport means is a transport belt that contacts a part of the recording material and transports the recording material,
6. The image fixing and solidifying apparatus according to claim 1, further comprising an air flow forming unit that forms an air flow for bringing the recording material into close contact with the conveyance belt.   7. The image fixing and solidifying apparatus according to claim 6, wherein the conveying unit conveys the recording material in contact with a surface opposite to a surface on which an image of the recording material heated by the heating unit is formed. . The image fixing and solidifying apparatus according to claim 1, further comprising: a suction unit that sucks vapor generated from the recording material transported by the transport unit.   9. The image fixing and solidifying apparatus according to claim 1, wherein the solidifying unit is a cooling unit that cools the recording material by contacting at least a surface side on which an image of the recording material is formed.   10. The cooling means includes a first conveying belt that is stretched by at least a plurality of rolls and that circulates and contacts a surface on which an image of the recording material is formed to convey the recording material. The image fixing and solidifying device described. The cooling means is stretched by a plurality of rolls and circulates to move the recording material between the first conveying belt and the second conveying belt by sandwiching and conveying the recording material together with the first conveying belt. The image fixing and solidifying device according to claim 10, further comprising: a cooling body that contacts the inner peripheral surface of the first conveying belt in a section that is nipped and conveyed and that cools the first conveying belt. The image formed on the recording material contains an amorphous resin and a crystalline resin in its components,
The temperature when the image on the recording material is kept warm by the electromagnetic wave reflected by the reflecting means, and the temperature at which the recording material comes into contact with the cooling means is the glass transition temperature and the crystalline temperature of the amorphous resin. Higher temperature,
12. The image fixing and solidifying apparatus according to claim 1, wherein the image fixing and solidifying device is cooled to a temperature lower than a glass transition temperature of the amorphous resin and a melting point of the crystalline resin by the cooling means. An image forming apparatus comprising: an image forming unit that forms an image on a recording material; and the image fixing and solidifying device according to claim 1.

Images