JP6155628B2 - Glossiness imparting apparatus and image forming apparatus - Google Patents

Description

  The present invention relates to a gloss applying device and an image forming apparatus. More specifically, the present invention relates to a gloss applying device for a toner image on which an image is formed by an image forming apparatus using an electrophotographic system such as a copying machine, a printer, a facsimile machine, or a multifunction machine of these.

  When an electrophotographic image forming apparatus obtains a toner image using a toner made of heat-meltable resin or the like, an unfixed toner image transferred to a recording material (also referred to as recording medium, recording paper, or paper) In order to fix the toner, a fixing device for heating and pressing is provided.

  For example, in a general two-roller type fixing device, a nip portion is formed by a heating roller and a pressure roller in which a heat source is arranged. The recording material onto which the unfixed toner image is transferred is sent to a nip portion between the heating roller and the pressure roller, and heat and pressure are applied from the heating roller and the pressure roller to the unfixed portion. The toner of the toner image becomes softened or melted, and after coming out of the nip, is fixed and fixed on the surface of the recording material. However, the toner image obtained by the fixing device having such a configuration has a problem that the glossiness of the image is not sufficient.

  In order to solve the above problems, the present invention relates to a gloss imparting means (gloss imparting device) which imparts a suitable gloss to a high image quality when a toner image formed on a recording material is fixed by a fixing device or after fixing by a fixing device. A number of techniques have been proposed.

  Patent Documents 1 to 3 include an endless belt stretched between a fixing roller and a support roller, and a pressure roller provided so as to face the fixing roller, and the recording paper is applied to the endless belt. There is disclosed a technique relating to gloss imparting that can be cooled by a cooling means in a contact state and then peeled off to obtain a high gloss print.

  As a cooling means for cooling the endless belt and the recording paper contacting the endless belt, for example, in Patent Document 1, a cooling fan is installed on the inner side of the endless belt and on the outer side (lower side) of the endless belt, What cools by the ventilation of a cooling fan, and what cools by contacting the heat pipe and heat sink which included water and other refrigerant | coolants are disclosed.

  Similarly, Patent Document 2 discloses cooling using a heat radiating member (heat sink) that contacts the inner peripheral surface of an endless belt to absorb and dissipate heat, an air cooling device using a cooling fan, or the like. ing. Further, Patent Document 3 discloses a cooling fan installed on the outer side (lower side) of the endless belt and cooled by blowing air from the cooling fan, or one that adjusts the air volume of the cooling fan.

  In the belt-type gloss imparting device, the toner on the recording material is once melted in the nip portion, and the toner (that is, the recording material) and the endless belt are brought into close contact with each other by the adhesion force between the toner and the endless belt. After being conveyed, cooled, and then peeled off from the endless belt, the surface state of the endless belt is transferred to the surface of the toner, the surface of the toner becomes smooth, and the glossiness increases.

  Therefore, in order to obtain a high gloss image, it is necessary to cool the endless belt (that is, the toner surface) to a desired temperature while the toner and the endless belt are in close contact with each other. For this reason, the cooling capacity and cooling efficiency of the cooling means are important.

  On the other hand, after the endless belt is cooled for the above-described reason, it is heated again to the necessary heating temperature in the next cycle (when it makes one round and then reaches the nip portion). As described above, in the gloss imparting device, the endless belt that has been forcibly cooled is repeatedly heated, and thus a large amount of electric power is required for heating in the nip portion. In the techniques described in Patent Documents 1 to 3, the cooling capacity and the cooling efficiency can be improved, but reduction of power consumption has not been considered.

  Accordingly, the present invention provides a gloss imparting device capable of reducing power consumption by increasing the cooling efficiency of the cooling means and improving the heating efficiency when heating the cooled endless belt again. With the goal.

In order to achieve such an object, the gloss imparting apparatus according to the present invention includes a heating member heated by a heat source, an endless belt that rotates while being heated by the heating member, and the heating member via the endless belt. A pressure member that forms a nip portion in pressure contact with the cooling member, and a cooling unit that cools the endless belt. A recording material on which a toner image is formed enters the nip portion, and the nip portion In the gloss imparting device which is conveyed in contact with the endless belt and is peeled off from the endless belt after being cooled by the cooling means, a part of the heat quantity of the endless belt is transferred to the endless belt. Heat transfer means for transmitting from a position downstream of the nip portion and upstream of the cooling means to a position downstream of the cooling means of the endless belt and upstream of the heating member And the heat transfer means is in contact with a heat recovery part which is a position downstream of the nip part and a heat dissipation part which is a position upstream of the heating member on the inner peripheral side of the endless belt. has a second endless belt that rotates Te, the second endless belt tension Troubled tension member are both in contact with the endless belt through the second endless belt, and the The heat transfer means has drive means for rotating the second endless belt in a predetermined speed and rotation direction, and the drive means moves the second endless belt in the rotation direction of the endless belt. Is to rotate in the opposite direction .

  According to the present invention, power consumption can be reduced by increasing the cooling efficiency of the cooling means and improving the heating efficiency when the endless belt to be cooled is heated again.

2 is a schematic configuration diagram of an image forming apparatus main body and a gloss applying apparatus main body. FIG. It is a schematic block diagram (1) which shows the basic composition of a glossiness imparting apparatus. It is a schematic block diagram (2) which shows the basic composition of a glossiness imparting apparatus. It is an example of sectional drawing of a cooling member. It is a schematic block diagram (1) of the glossiness imparting apparatus concerning this embodiment. It is a cross-sectional block diagram at the time of seeing a preheating means from the inner peripheral side of an endless belt. It is a schematic block diagram (2) of the gloss provision apparatus which concerns on this embodiment.

  Hereinafter, a configuration according to the present invention will be described in detail based on the embodiment shown in FIGS.

  The gloss imparting apparatus according to the present embodiment includes a heating member (gloss imparting heating roller 21) that is heated by a heat source (halogen heater 23), and an endless belt (endless belt 24) that rotates while being heated by the heating member. A pressure member (gloss imparting pressure roller 22) that presses against the heating member via an endless belt to form a nip portion, and a cooling means (cooling member 41 or the like) that cools the endless belt. Then, the recording material (recording material P) on which the toner image (toner image T) is formed enters the nip portion, is conveyed in contact with the endless belt from the nip portion, is cooled by the cooling means, and is endless. In the gloss imparting device (gloss imparting device 300) that peels from the belt, a part of the heat quantity of the endless belt is transferred from the position downstream of the nip portion of the endless belt and upstream of the cooling means. A downstream side of the cooling means Jo belt in which comprises a heat transfer means for transmitting to the upstream side of the position of the heating member (preheating means 80, 90). In addition, the code | symbol in embodiment and the example of application are shown in a parenthesis.

  FIG. 1 is a schematic configuration diagram of an image forming apparatus main body 100 and a gloss imparting apparatus main body 200. FIG. 1 is a schematic configuration diagram showing a state in which a gloss applying apparatus main body 200 having a gloss applying apparatus 300 according to the present embodiment is connected to and attached to the image forming apparatus main body 100.

  In FIG. 1, the gloss imparting device 300 is a gloss imparting device main body 200 and is a device different from the image forming apparatus main body 100, but is not necessarily a separate device, and is not necessarily an internal device of the image forming apparatus main body 100. It is good also as a structure provided with the gloss providing apparatus 300 in the fixing device downstream.

(Image forming device)
First, the configuration and operation of the image forming apparatus will be described. In FIG. 1, 100 is an image forming apparatus main body of a tandem type color copying machine as an image forming apparatus, 2 is a writing unit that emits laser light based on input image information, and 3 is a document that transports a document D to a document reading unit 4. A conveyance unit, 4 is a document reading unit that reads image information of the document D, 7 is a sheet feeding unit that accommodates a recording material P such as transfer paper, 9 is a registration roller that adjusts the conveyance timing of the recording material P, and 11Y and 11M. , 11C, 11BK are photosensitive drums on which toner images of the respective colors (yellow, magenta, cyan, black) are formed, 12 is a charging unit that charges the photosensitive drums 11Y, 11M, 11C, and 11BK, and 13 is each photosensitive member. A developing unit for developing the electrostatic latent images formed on the body drums 11Y, 11M, 11C, and 11BK, and a toner image formed on each of the photoreceptor drums 11Y, 11M, 11C, and 11BK A transfer bias roller (primary transfer bias roller) for transferring the toner image on the recording material P, 15 is a cleaning unit for collecting untransferred toner on the photosensitive drums 11Y, 11M, 11C, and 11BK, and 16 is an intermediate transfer belt. 17 is an intermediate transfer belt cleaning unit for cleaning 17, 17 is an intermediate transfer belt on which toner images of a plurality of colors are transferred in an overlapping manner, and 18 is a secondary for transferring a color toner image on the intermediate transfer belt 17 onto a recording material P. A transfer bias roller 20 is a fixing device that fixes a toner image (unfixed image) on the recording material P.

  Reference numeral 300 denotes a peripheral device installed outside the image forming apparatus main body 100 and is a gloss applying device that applies gloss to the toner image carried on the recording material P. The gloss applying device 300 is a device for improving the gloss of the image on the recording material P after the fixing process discharged from the image forming apparatus main body 100.

  An operation during normal color image formation in the image forming apparatus will be described. First, the document D is transported from the document table in the direction of the arrow in the drawing by the transport roller of the document transport unit 3 and placed on the contact glass 5 of the document reading unit 4. Then, the document reading unit 4 optically reads the image information of the document D placed on the contact glass 5.

  Specifically, the document reading unit 4 scans the image of the document D on the contact glass 5 while irradiating light emitted from an illumination lamp. Then, the light reflected by the document D is imaged on the color sensor via the mirror group and the lens. The color image information of the document D is read for each RGB (red, green, blue) color separation light by the color sensor, and then converted into an electrical image signal. Further, color conversion processing, color correction processing, spatial frequency correction processing, and the like are performed by the image processing unit based on the RGB color separation image signals to obtain yellow, magenta, cyan, and black color image information.

  Then, the image information of each color of yellow, magenta, cyan, and black is transmitted to the writing unit 2. The writing unit 2 emits laser light (exposure light) based on the image information of each color toward the corresponding photosensitive drums 11Y, 11M, 11C, and 11BK.

  On the other hand, the four photosensitive drums 11Y, 11M, 11C, and 11BK are rotated clockwise in FIG. First, the surfaces of the photosensitive drums 11Y, 11M, 11C, and 11BK are uniformly charged at a portion facing the charging unit 12 (charging process). Thus, a charged potential is formed on the photoconductive drums 11Y, 11M, 11C, and 11BK. Thereafter, the surfaces of the charged photosensitive drums 11Y, 11M, 11C, and 11BK reach the irradiation positions of the respective laser beams.

  In the writing unit 2, laser light corresponding to the image signal is emitted from the four light sources corresponding to each color. Each laser beam passes through a different optical path for each color component of yellow, magenta, cyan, and black (exposure process).

  Laser light corresponding to the yellow component is irradiated on the surface of the first photosensitive drum 11Y from the left side of the drawing. At this time, the yellow component laser light is scanned in the rotation axis direction (main scanning direction) of the photosensitive drum 11Y by a polygon mirror that rotates at high speed. Thus, an electrostatic latent image corresponding to the yellow component is formed on the photosensitive drum 11Y charged by the charging unit 12.

  Similarly, the laser beam corresponding to the magenta component is irradiated onto the surface of the second photosensitive drum 11M from the left side of the paper, and an electrostatic latent image corresponding to the magenta component is formed. The cyan component laser light is applied to the surface of the third photosensitive drum 11C from the left side of the paper, and an electrostatic latent image of the cyan component is formed. The black component laser beam is applied to the surface of the fourth photosensitive drum 11BK from the left side of the paper, and an electrostatic latent image of the black component is formed.

  Thereafter, the surfaces of the photosensitive drums 11Y, 11M, 11C, and 11BK on which the electrostatic latent images of the respective colors are formed reach the positions facing the developing unit 13, respectively. Then, each color toner is supplied from each developing unit 13 onto the photosensitive drums 11Y, 11M, 11C, and 11BK, and the latent images on the photosensitive drums 11Y, 11M, 11C, and 11BK are developed (developing step).

  Thereafter, the surfaces of the photoconductive drums 11Y, 11M, 11C, and 11BK after the development process reach the opposed portions to the intermediate transfer belt 17, respectively. Here, a transfer bias roller 14 is installed at each facing portion so as to contact the inner peripheral surface of the intermediate transfer belt 17. Then, the toner images of the respective colors formed on the photosensitive drums 11Y, 11M, 11C, and 11BK are sequentially superimposed and transferred onto the intermediate transfer belt 17 at the position of the transfer bias roller 14 (primary transfer process). .

  Then, the surfaces of the photosensitive drums 11Y, 11M, 11C, and 11BK after the transfer process reach positions facing the cleaning unit 15, respectively. Then, the untransferred toner remaining on the photosensitive drums 11Y, 11M, 11C, and 11BK is collected by the cleaning unit 15 (cleaning process).

  Thereafter, the surfaces of the photoconductor drums 11Y, 11M, 11C, and 11BK pass through a static elimination unit (not shown), and a series of image forming processes on the photoconductor drums 11Y, 11M, 11C, and 11BK is completed.

On the other hand, the intermediate transfer belt 17 on which the toners of the respective colors on the photosensitive drums 11Y, 11M, 11C, and 11BK are transferred (carrying) are run in the clockwise direction in the drawing and are connected to the secondary transfer bias roller 18. Reach the opposite position. Then, a color toner image carried on the intermediate transfer belt 17 is transferred onto the recording material P at a position facing the secondary transfer bias roller 18 (secondary transfer step).

  Thereafter, the surface of the intermediate transfer belt 17 reaches the position of the intermediate transfer belt cleaning unit 16. Then, the untransferred toner adhered on the intermediate transfer belt 17 is collected by the intermediate transfer belt cleaning unit 16, and a series of transfer processes in the intermediate transfer belt 17 is completed.

  Here, the recording material P conveyed between the intermediate transfer belt 17 and the secondary transfer bias roller 18 (secondary transfer nip) is conveyed from the paper supply unit 7 via the registration roller 9 and the like. is there.

  Specifically, the recording material P fed by the paper feeding roller 8 from the paper feeding unit 7 that stores the recording material P is guided to the registration roller 9 after passing through the conveyance guide. The recording material P that has reached the registration roller 9 is conveyed toward the secondary transfer nip at the same timing.

  Then, the recording material P to which the full color image has been transferred is guided to the fixing device 20 by the transport belt. In the fixing device 20, the color image (toner) is fixed on the recording material P at the nip portion between the fixing belt and the pressure roller.

  When the “glossy mode” for improving the glossiness of the output image is not selected, the image forming apparatus main body 100 is moved by the movement of the switching claw as shown by the broken arrow in FIG. The output image is discharged to the outside, and a series of image forming processes is completed.

  On the other hand, when the “gloss mode” is selected, the gloss applying device 300 is guided from the image forming apparatus main body 100 to the gloss applying device 300 by the movement of the switching claw, as indicated by the solid arrow in FIG. After glossiness is imparted to the image on the recording material P, the image is discharged from the glossiness imparting apparatus 300 as an output image, and a series of image forming processes is completed.

  The “glossy mode” is a mode that can be arbitrarily selected by the user by operating a button from an operation panel (not shown) of the image forming apparatus main body 100, and requires high glossiness such as a photographic image. This is selected when outputting an image.

(Configuration of gloss applicator)
Next, the basic configuration and operation of the gloss applying device will be described. FIG. 2 is a schematic configuration diagram showing a basic configuration of the gloss applying device.

  The gloss imparting device 300 is stretched between a gloss imparting heating roller (heating member) 21 heated by a halogen heater 23 as a heat source, a gloss imparting heating roller 21, a peeling roller 27, a driving roller 26, and a tension roller 28. An endless belt 24 that rotates in the direction of the arrow in the figure while being heated by the gloss imparting heating roller 21, and a gloss imparting pressure roller that presses the gloss imparting heating roller 21 via the endless belt 24 to form a nip portion. (Pressure member) 22 and cooling members 41, 51, 61 for cooling the endless belt 24 on the inner peripheral side of the endless belt 24, and the endless belt is driven by the rotation of the driving roller 26. 24 is configured to rotate in the direction of the arrow.

  Then, the recording material P on which the toner image T is formed enters the nip portion, is conveyed while being in contact with the endless belt 24 from the nip portion, and is cooled by the cooling members 41, 51, 61 and then endless. It is peeled off from the belt 24.

  Further, temperature detecting means 25 for detecting the temperature of the surface of the endless belt 24 is provided. The temperature detecting means 25 is preferably a non-contact type thermopile, but may be a contact type thermistor (a contact type example is shown in FIG. 2). A temperature control unit (not shown) performs on / off control of the halogen heater 23 based on the temperature detection result of the temperature detection unit 25.

  Hereinafter, each member of the gloss imparting apparatus 300 will be described. The gloss imparting heating roller 21 is made of a cylindrical metal roller, and is a roller member formed of a metal material having a high thermal conductivity such as aluminum and having an outer diameter of about 50 to 120 mm. A halogen heater 23 is built in the hollow portion of the cylindrical body, and the gloss imparting heating roller 21 is heated by the halogen heater 23. It is also preferable to provide a heat pipe in the longitudinal direction for thermal equilibrium.

  Both ends of the halogen heater 23 are fixed to side plates (not shown) of the gloss applying device 300. Then, the gloss imparting heating roller 21 is heated by the radiant heat from the halogen heater 23 whose output is controlled by a power supply unit (AC power source) (not shown), and further from the surface of the endless belt 24 heated by the gloss imparting heating roller 21. Heat is applied to the toner image T on the recording material P.

  The output control of the halogen heater 23 is performed based on the temperature detection result by the temperature detection means 25 provided in a non-contact manner on the endless belt 24. For example, the AC voltage is applied to the halogen heater 23 for the energization time determined based on the detection result of the temperature detection means 25. By controlling the output of the halogen heater 23 as described above, the surface temperature of the endless belt 24 stretched around the gloss-imparting heating roller 21 can be adjusted and controlled to a desired temperature, for example, about 100 to 250 ° C.

  The gloss imparting pressure roller 22 has an outer diameter of about 50 to 120 mm, and an elastic layer (silicone rubber layer) having a thickness of 5 to 30 mm is formed on the outer periphery of the cylindrical metal roller. This is a roller member formed with a tube material of fluororesin having a thickness of 30 to 200 μm.

  The gloss imparting pressure roller 22 is pressed against the gloss imparting heating roller 21 via an endless belt 24 by a pressurizing mechanism (not shown) to form a nip portion (gloss imparting nip portion). The width of the nip portion is set to about 10 to 40 mm.

  The endless belt 24 is a belt member having a two-layer structure of a base material and a surface layer formed on the outer peripheral surface side. As the belt base material, for example, a resin sheet having a high heat resistance with a thickness of 10 to 300 μm can be used. Specifically, polymer sheets such as polyester, polyethylene, polyethylene terephthalate, polyethersulfone, polyetherketone, polysulfone, polyimide, polyamideimide, and polyamide can be used. The surface layer can be formed of a surface layer forming material such as a silicone resin or a fluorine resin having a thickness of 1 to 100 μm, for example.

  Further, since the endless belt 24 is a belt for imparting gloss to an image as described above, the surface of the surface layer is formed as a smooth surface suitable for imparting high gloss. In this case, the smooth surface is formed so that, for example, the arithmetic average roughness Ra is 0.3 μm or less, more preferably 0.1 μm or less. The endless belt 24 is rotationally driven at a peripheral speed of about 50 to 700 mm / second by a driving force of a driving roller 26 that is driven and controlled by a driving unit (not shown). The endless belt 24 may be rotationally driven by the driving force of the nip portion instead of or in accordance with the driving force of the driving roller 26.

  The cooling means 40 cools the cooling member 41 by a liquid cooling method, and is configured by connecting the cooling member 41, a radiator 42, a tank 43, and a pump 44 by a tube. Similarly, the cooling means 50 includes a cooling member 51, a radiator 52, a tank 53, and a pump 54 connected by a tube, and the cooling means 60 includes a cooling member 61, a radiator 62, and a tank 63. The pump 64 is connected by a tube.

  The cooling members 41, 51, 61 are sequentially provided at positions where the endless belt 24 contacts on the inner circumferential side of the nip portion between the gloss imparting heating roller 21 and the gloss imparting pressure roller 22 on the downstream side in the conveyance direction of the recording material P. As a result, the endless belt 24 is cooled. In addition, the toner image T on the recording material P conveyed in close contact with the endless belt 24 can be cooled. As shown in FIG. 2, cooling members 41, 51, 61 are arranged so as to press the inner peripheral surface of the endless belt 24 in substantially the entire region from the position of the gloss imparting heating roller 21 to the position of the peeling roller 27. By providing, the adhesiveness of the endless belt 24 and the cooling members 41, 51, 61 can be improved.

  Hereinafter, although the structural example of the cooling means 40 is demonstrated, it is comprised similarly about the cooling means 50 and 60. FIG. The cooling means 40, 50, 60 are configured to be capable of cooling control independently.

  The cooling means 40 is provided with a pump 44 for circulating the cooling liquid through the cooling member 41, a radiator 42 for circulating and cooling the cooling liquid, and a tank 43 for storing the cooling liquid, which are connected by a tube. And in the cooling means 40, a liquid circulates in the arrow direction shown in FIG. 2, and the cooling member 41 is cooled.

  The cooling member 41 is made of a metal having good thermal conductivity (for example, aluminum), and a hole for circulating the coolant is formed inside the cooling member 41 so as to reciprocate inside the cooling member 41.

The radiator 42 is provided with a fan for air-cooling and exhausting the liquid flowing in the radiator 42. The fan is configured, for example, as a cooling adjustment unit that can vary the air volume in the range of 0 to 11 m ³ / min.

  The pump 44 is configured as a flow rate adjusting unit that can change the flow rate of the liquid sent from the tank 43 toward the cooling member 41 in a range of 0 to 15 liters / minute, for example.

  The cooling means 40, 50 and 60 are liquid cooling systems using a cooling liquid, but may be an air cooling system or a mixed system of water cooling and air cooling. By setting it as the above cooling systems, it becomes possible to cool the endless belt 24 efficiently.

  In the example shown in FIG. 2, the cooling member 41 provided on the gloss imparting heating roller 21 side is configured to have a larger contact area with the endless belt 24 than the cooling member 61 provided on the peeling roller 27 side. ing. That is, the length L1 of the cooling member 41 in the conveyance direction is longer than the length L2 of the cooling member 51 in the conveyance direction and the length L3 of the cooling member 61 (L1> L2> L3). In addition, what is necessary is just to select suitably the length and the number of conveyance direction (about 2-5 pieces are suitable) for a cooling member according to a required cooling condition.

  Further, for example, as shown in FIG. 3, the cooling means may be constituted by a cooling member 71, radiators 72 a, 72 b, 72 c, a tank 73, and a pump 74, and may be a single cooling means 70.

  FIG. 4 shows a cross-sectional shape of the cooling member 71 (a cross section seen from above in FIG. 3). The cooling member 71 is formed of a metal having good thermal conductivity, such as aluminum, and a flow path 71a in which the coolant can circulate while reciprocating in a zigzag manner in the width direction (perpendicular to the plane of FIG. 3). (Grooves) are formed, and liquid inlet portions 71b and outlet portions 71c are provided at both ends, respectively, and the cooling member 71 can be cooled by circulating the liquid inside.

(Glossing device operation)
For the recording material P on which the toner image is fixed by the image forming apparatus main body 100 shown in FIG. 1, when it is desired to obtain a high glossiness like a photographic image, the glossiness is increased by passing the gloss applying apparatus main body 200. can do. An example of a gloss imparting operation to the toner image in the gloss imparting device 300 will be described.

  As shown in FIG. 2, the recording material P on which the toner image T is fixed is guided to a nip portion formed by the glossing heating roller 21 and the glossing pressure roller 22 by the guide member 30 of the glossing device 300. The recording material P passes through the nip portion and is heated.

  For example, when the surface temperature of the endless belt 24 (location of the temperature detecting means 25) is controlled and maintained at 150 ° C., the recording material P passes through the nip portion and becomes 100 ° C. to 120 ° C., and the toner image T is formed. Softens and melts. The recording material P is conveyed while being in close contact with the belt by the close contact force of the toner image T to the endless belt 24. The recording material P is cooled by the endless belt 24 being conveyed in contact with the cooling members 41, 51, 61 and is peeled off from the belt at the position of the peeling roller 27. The toner image T of the recording material P cooled in a state of being in close contact with the endless belt 24 is cooled to 40 ° C. or less when solidified and solidified by transferring the surface state of the endless belt 24 to the toner image surface. Gloss can be obtained.

  The recording material P peeled from the endless belt 24 is guided by the guide member 31 and discharged from the discharge roller 32 to the discharge tray of the gloss imparting device 300.

(Heat transfer means)
In the gloss applying device 300 shown in FIGS. 2 and 3, the endless belt 24 cooled by the cooling means 40, 50, 60, 70 goes around once and reaches the nip portion, and then the gloss applying heating roller 21. It will be heated by. As described above, the gloss applying device 300 repeats the operation of heating the endless belt 24 that has been forcibly cooled again. Therefore, when heating is performed in the nip portion, a large amount of power is required for heating. .

  In addition, regarding the number of cooling members and the cooling method, various configurations can be considered as described above. In any case, the heat recovered by the cooling member is released into the atmosphere by a radiator or the like.

  Therefore, the gloss applying apparatus 300 according to the present embodiment collects a part of the heat recovered by the cooling means before that and uses a preheating means (heat transfer means) that is a mechanism used for heating in the nip portion. ) 80.

  That is, the preheating means 80 increases the cooling efficiency by recovering a part of the heat before the endless belt 24 is cooled by the cooling means, and the endless belt is cooled by the cooling means. 24. Thereby, the heating efficiency when heating the cooled endless belt 24 again can be improved, and the power consumption can be reduced.

[Heat pipe configuration]
FIG. 5 is a schematic configuration diagram illustrating an example of the configuration of the gloss imparting apparatus 300 according to the present embodiment. The gloss imparting device 300 shown in FIG. The pre-heating means 80 includes a heat recovery unit 81 that is in contact with the endless belt 24 on the downstream side of the nip portion and on the upstream side of the cooling members 41, 51, 61 (preferably immediately downstream of the nip portion). The heat dissipating part 82 abuts the endless belt 24 cooled by the cooling means 40, 50, 60 on the upstream side of the heating position by the glossing heating roller 21 (preferably just upstream of the heating position). And a heat transfer portion 83 that connects the heat recovery portion 81 and the heat dissipation portion 82. The temperature detecting means 25 is provided with a non-contact type thermopile.

  FIG. 6 shows a cross-sectional configuration diagram of the preheating unit 80 when viewed from the inner peripheral side of the endless belt 24 (when viewed from the left side of FIG. 5). In the figure, reference numeral 24a denotes an endless belt 24 in a cooled state before being heated again, and reference numeral 24b denotes an endless belt 24 in a high temperature state before being cooled by a cooling means after being heated by the gloss imparting heating roller 21. Is shown.

  As shown in FIG. 6, the heat recovery unit 81 and the heat radiating unit 82 are formed so as to be in sliding contact with the inner peripheral surface of the endless belt 24 in the paper width direction (the axial direction of the gloss imparting heating roller 21). The heat pipes 81a and 82a are provided. The heat transfer section 83 has a configuration in which a plurality of heat pipes are formed in the axial direction, one end of which is in contact with the heat recovery section 81 and the other end is in contact with the heat dissipation section 82.

  Therefore, the heat recovery part 81 absorbs heat from the endless belt 24 immediately after the nip part, and the temperature rises. Further, since the heat dissipating part 82 is in contact with the cooled endless belt 24 immediately before being heated, a large temperature difference occurs between the heat recovery part 81 and the heat dissipating part 82. For this reason, the heat recovered by the heat recovery unit 81 moves through the heat pipe of the heat transfer unit 83 as indicated by the arrows in the figure, and the heat is transferred to the heat dissipation unit 82. Therefore, the endless belt 24 cooled immediately before being heated by the heat radiating portion 82 is preheated (referred to as heating before being heated by the gloss imparting heating roller 21).

  Thus, conventionally, a part of the heat recovered and discarded by the cooling means 40, 50, 60 is recovered, and this is recovered before the cooled endless belt 24 enters the glossing heating roller 21. By conducting the heat and pre-heating, the load of the gloss imparting heating roller 21 is lowered to increase the heating efficiency, and the power consumption can be reduced.

  Moreover, since heat recovery is performed on the upstream side of the cooling means 40, 50, 60, the cooling efficiency of the cooling means 40, 50, 60 can be increased. In other words, the preheating unit 80 also functions as a cooling unit. Therefore, it is a more suitable structure also about glossiness which is an original function.

  The pre-heating means 80 may be made of a metal having good thermal conductivity, and is preferably aluminum, for example. In this embodiment, the heat pipe is used to increase the heat conduction efficiency. However, depending on the achieved cost and the required efficiency, the heat pipe may be composed of only a metal having good heat conductivity.

[Belt configuration]
FIG. 7 is a schematic configuration diagram illustrating another example of the configuration of the gloss imparting apparatus 300 according to the present embodiment. The gloss imparting device 300 shown in FIG. 7 includes preheating means 90. The preheating means 90 is downstream of the nip portion and upstream of the cooling members 41, 51, 61 (preferably directly downstream of the nip portion), and the endless belt 24 via the heat transfer belt 93. The heat recovery unit roller 91 that abuts and the endless belt 24 cooled by the cooling means 40, 50, 60 endlessly on the upstream side of the heating position by the glossing heating roller 21 (preferably just upstream of the heating position). The heat transfer belt (second endless belt) is a heat-dissipating roller 92 that is in contact with the belt 24 via the heat-transfer belt 93, and an endless belt member that rotates around the heat recovery roller 91 and the heat-dissipating roller 92 Shaped belt) 93.

  The heat recovery unit roller 91 and the heat dissipation unit roller 92 are in sliding contact with the inner peripheral surface of the endless belt 24 through the heat transfer belt 93 in the paper width direction (the axial direction of the gloss imparting heating roller 21). It is configured as follows.

  The heat transfer belt 93 is in contact with the endless belt 24 immediately after the nip portion where the heat recovery unit roller 91 is stretched, and is cooled endless immediately before being heated while the heat dissipation unit roller 92 is stretched. In contact with the belt 24. For this reason, a large temperature difference always occurs during the driving of the gloss imparting device 300, and heat exchange is performed via the heat transfer belt 93.

  Since the endless belt 24 before reheating is sufficiently cooled to a position close to room temperature, a large amount of electric power is always required for reheating. However, the temperature of the endless belt 24 is reduced by the preheating means 90. The power consumption for reheating can be suppressed. Moreover, since heat recovery is performed on the upstream side of the cooling means 40, 50, 60, the cooling efficiency of the cooling means 40, 50, 60 can be increased. In other words, the preheating means 90 also functions as a cooling means.

  In the pre-heating unit 90 having a belt configuration using the heat transfer belt 93, no sliding load is generated between the endless belt 24 and the pre-heating unit 90 (heat transfer belt 93), so the endless belt 24 is worn. The preheating can be effectively performed without any problem.

  In the example shown in FIG. 7, the heat transfer belt 93 is rotated in the direction of the arrow in the drawing following the rotation of the endless belt 24. According to this configuration, the preheating unit 90 does not require a driving unit, and thus can have a simple configuration.

  In addition, either one or both of the heat recovery unit roller 91 and the heat radiation unit roller 92 are provided with a driving unit so that the heat transfer belt 93 can be driven and controlled independently of the endless belt 24. It is also preferable. According to this, the heat transfer belt 93 can be rotated with respect to the endless belt 24 in an arbitrary direction (for example, the reverse direction to FIG. 7) and a speed (for example, constant speed), and heat transfer efficiency is good. It can be driven at an arbitrary rotational speed.

  The material of the heat transfer belt 93 is preferably a metal material having high thermal conductivity and good flexibility, preferably stainless steel, but a resin can also be used. Further, the heat recovery unit roller 91 and the heat radiation unit roller 92 are preferably made of a material that has good heat insulation and can be easily deformed so as to be in close contact with the heat transfer belt 93, preferably a heat-resistant sponge. Alternatively, a resin or metal roller may be used.

  Further, although the heat transfer belt 93 is wound around two rollers, the number of rollers may be three or more. From the viewpoint of heat conduction efficiency, it is preferable to use two rollers.

  The preheating unit 90 preferably includes contact / separation means for releasing the contact state between the outer peripheral surface of the heat transfer belt 93 and the inner peripheral surface of the endless belt 24 so as to be in a separated state. The contact / separation means can release the contact state between the heat transfer belt 93 and the endless belt 24 by, for example, displacing the axial positions of the two rollers. By driving the contacting / separating means according to the required cooling performance or the like, it is possible to control on / off of the preheating control. Further, when the preheating control is unnecessary, the sliding load on the inner peripheral surface of the endless belt 24 can be reduced by separating the preheating means 90 from the endless belt 24.

  According to the image forming apparatus (FIG. 1) provided with the gloss applying apparatus described above, it is possible to provide an image forming apparatus including a gloss applying apparatus capable of realizing energy saving.

  The above-described embodiment is a preferred embodiment of the present invention, but is not limited thereto, and various modifications can be made without departing from the gist of the present invention.

2 Writing section 3 Document transport section 4 Document reading section 5 Contact glass 7 Paper feeding section 8 Paper feeding roller 9 Registration roller 11Y, 11M, 11C, 11BK Photosensitive drum 12 Charging section 13 Developing section 14 Transfer bias roller (primary transfer bias) roller)
15 Cleaning unit 16 Intermediate transfer belt cleaning unit 17 Intermediate transfer belt 18 Secondary transfer bias roller 20 Fixing device 21 Gloss applying heating roller (heating member)
22 Gloss imparting pressure roller (pressure member)
23 Halogen heater (heat source)
24 endless belt 25 temperature detecting means 26 driving roller 27 peeling roller 28 tension roller 30 guide member (inlet side)
31 Guide member (exit side)
32 Discharge roller 40, 50, 60, 70 Cooling means 41, 51, 61, 71 Cooling member 42, 52, 62, 72a-c Radiator 43, 53, 63, 73 Tank 44, 54, 64, 74 Pump 71a Flow path 71b Inlet part 71c Outlet part 80 Preheating means (heat transfer means)
81 heat recovery part 82 heat dissipation part 81a, 82a heat pipe 83 heat transfer part 90 preheating means (heat transfer means)
91 Heat recovery section roller 92 Heat radiation section roller 93 Heat transfer belt 100 Image forming apparatus body 200 Gloss applying apparatus body 300 Gloss applying apparatus D Document P Recording material T Toner image

JP 2009-14876 A JP 2004-325934 A Japanese Patent Laid-Open No. 5-333643

Claims (6)

A heating member heated by a heat source;
An endless belt that rotates while being heated by the heating member;
A pressure member that presses against the heating member via the endless belt to form a nip portion; and
Cooling means for cooling the endless belt,
Gloss is imparted by separating the recording material on which the toner image is formed from entering the nip portion, transporting the recording material in contact with the endless belt from the nip portion, cooling the cooling means, and then peeling from the endless belt. In the device
Part of the amount of heat of the endless belt is downstream of the nip portion of the endless belt and upstream of the cooling means, and downstream of the cooling means of the endless belt. Heat transfer means for transferring to a position on the upstream side of the heating member;
The heat transfer means rotates in contact with a heat recovery portion which is a position downstream of the nip portion and a heat dissipation portion which is a position upstream of the heating member on the inner peripheral side of the endless belt. A second endless belt that moves,
Stretching members for Troubled tension the second endless belt are all come into contact with the endless belt through the second endless belt,
And the heat transfer means has drive means for rotating the second endless belt in a predetermined speed and rotation direction,
The drive means rotates the second endless belt in a direction opposite to the rotation direction of the endless belt .   The heat transfer means transmits a part of the heat amount of the endless belt from a position immediately downstream of the nip portion to a position immediately upstream of the heating member. The gloss imparting device described.   The gloss applying apparatus according to claim 1, wherein the tension member is deformable along the second endless belt.   The gloss application according to any one of claims 1 to 3, wherein the stretching member includes a heat recovery roller provided in the heat recovery unit and a heat dissipation roller provided in the heat dissipation unit. apparatus. The gloss applying device according to any one of claims 1 to 4 , wherein the heat transfer means is provided so as to be able to contact and separate from the endless belt. The gloss providing device according to any one of claims 1 to 5, the image forming apparatus, characterized in that it comprises to be linked to the internal or external.