JP2017146574A - Glossiness imparting device and image formation apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the cooling performance of a glossiness imparting device.SOLUTION: A glossiness imparting device 300 includes: a glossiness imparting heating roller 21; an endless belt 24 which is stretched over a plurality of members including the glossiness imparting heating roller 21 and rotates; a glossiness imparting pressure roller 22 which is brought into pressure-contact with the glossiness imparting heating roller 21 via the endless belt 24 and forms a nip part; and cooling means 40 which cools the endless belt 24. The glossiness imparting device makes a recording material P formed with a toner image T enter the nip part and conveys the recording material in the state of contacting the endless belt 24 from the nip part. The cooling means 40 includes a cooling belt 41 which is provided on the inner peripheral side of the endless belt 24 and rotates in the state where a portion thereof is brought into contact with the endless belt 24. The cooling belt 41 is stretched over at least a drive roller 43 applied with the driving force and a cooling roller 42 cooling the cooling belt 41. The roller on the upstream side in the conveyance direction of the recording material P with respect to the cooling roller 42 is the drive roller 43.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a gloss applying device and an image forming apparatus.

  Various image forming apparatuses using an electrophotographic system have been devised as image forming apparatuses such as copying machines, facsimiles, and printers, and are well-known techniques. In the image forming process, an electrostatic latent image is formed on the surface of the photosensitive drum as an image carrier, and the electrostatic latent image on the photosensitive drum is developed with a toner as a developer to be visualized and developed. The image is transferred to a recording material (also referred to as paper, recording medium, or recording paper) by a transfer device to carry the image, and the toner image on the recording material is fixed by a fixing device using pressure or heat. ing.

  In this fixing device, a fixing member and a pressing member constituted by opposing rollers or belts or a combination thereof are arranged so as to contact each other to form a nip portion, and a recording material is sandwiched in the nip portion, Heat and pressure are applied so that the toner image is melted by heat and simultaneously fixed on the recording material by the pressure between the two members. 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.

  To solve the above problems, a number of techniques have been proposed for imparting gloss appropriately to give a high gloss image when a toner image formed on a recording material is fixed by a fixing device or after fixing by a fixing device. ing.

  For example, in Patent Document 1, after the fixing belt is heated to melt the toner, the toner is cooled without being separated and the fixing belt and the toner are in close contact with each other, the toner surface is cooled to a predetermined temperature, and the toner is solidified. A fixing device that separates in a state has been proposed. According to such a fixing device, since the toner can be separated from the fixing surface in a solidified state, the smoothness of the separation and fixing surface can be copied (improvement of glossiness).

  By the way, it is known that “cooling” at the time of glossing is much more difficult than “heating”. This is because, in the case of heating, the heating temperature can be greatly increased with respect to the predetermined temperature required for rapid heating, and the thermal gradient can be increased, whereas in the case of cooling, the temperature is cooled from room temperature. This is because moisture in the air causes a dew condensation phenomenon, so that the cooling temperature is set near room temperature.

  For example, when a halogen heater is used in the fixing roller as a heat source, the inner surface of the fixing roller can be heated to 800 ° C. or higher in order to raise the temperature of the fixing roller to 100 to 200 ° C., and the temperature gradient is 600 to 700 degrees. To reach. However, in the case of cooling, for example, in order to cool the fixing surface of about 140 to 160 ° C. to about 40 ° C., the temperature gradient is 100 deg + α even if the fixing surface is cooled to about 20 to 30 ° C., and the cooling efficiency is overwhelming. I understand that is bad. Therefore, in the case of cooling, unlike heating, it is slowly cooled over time.

  In the case of heating using a fixing belt, the temperature rises after the heating, and the fixing surface and the toner are firmly bonded to each other by the adhesive force of the heated toner during the high temperature. However, if the recording material is cooled together with the fixing belt after heating and the temperature of the toner is sufficiently lowered, the toner is solidified as it is cooled, the adhesive force with the fixing belt is reduced, and partial lifting occurs, resulting in uneven image quality. May be the cause.

  In particular, when the vector in the traveling direction of the fixing belt being cooled changes greatly (when the curvature on the conveyance path changes), so-called curvature separation occurs, and the partial movement before reaching the position to be separated is partially achieved. In addition, the fixing belt and the image are separated from each other over the entire surface, and there is a problem that uneven cooling occurs and poor conveyance occurs in the image.

  In other words, when the fixing belt and the recording material are cooled, the R shape of the surface of the cooling member in contact with the fixing belt cannot be increased, so that the shape is inevitably close to a flat surface (for example, patents). Reference 2).

  Further, in a configuration in which a fixing belt is wound around a metal roller member (hereinafter referred to as a cooling roller) as a cooling member, it is difficult to efficiently cool the fixing belt. That is, with such a configuration, in order not to cause a change in curvature, the cooling roller and the fixing belt can only be arranged so that they slightly contact each other. It becomes a little and efficient cooling is difficult. Further, if a cooling roller is used to obtain a sufficient cooling efficiency, it is necessary to increase the roller diameter to form a huge roller, which causes a problem that the apparatus becomes large. Although it is conceivable to arrange a large number of small-diameter cooling rollers, the structure becomes complicated and the cost increases.

  In addition, there is a type that uses a sliding method with the fixing belt without rotating the cooling member, but if the cooling member is a sliding type, there is a problem that wear occurs due to friction between the cooling member and the fixing belt surface. . In addition, the cooling member receives heat from the fixing belt, and the heat is not efficiently discharged (because the temperature of the refrigerant is near room temperature), and the heat received from the fixing belt is generated on the surface of the cooling member. It is difficult to generate a cooling effect on the fixing belt.

  As described above, when the cooling member has a roller shape, it is necessary to use a roller having a large roller diameter, which causes a problem that the fixing device is increased in size. In addition, when the cooling member is fixed and the sliding type is used, there is a problem that wear occurs due to sliding between the cooling member and the fixing belt, and cooling efficiency decreases due to heat retention.

  On the other hand, in Patent Document 3, as shown in FIG. 11, the metal cooling rollers 56a and 56b and the metal rotating around the cooling rollers 56a and 56b are rotated on the inner peripheral side of the fixing belt 53. There is disclosed a fixing device 50 that has a cooling belt 57 made of metal and efficiently cools the fixing belt 53 by rotating while the cooling belt 57 is in contact with the fixing belt 53. In the figure, reference numeral 51 denotes a fixing roller, 52 denotes a pressure roller, 54 denotes a tension roller, 55 denotes a driving roller, and 58 denotes a heat source.

  However, in the configuration using the cooling roller and the cooling belt disclosed in Patent Document 3, there is still room for further study in improving the cooling performance.

  Then, an object of this invention is to provide the glossiness imparting apparatus which can improve cooling performance.

  In order to achieve this object, a gloss imparting device according to the present invention includes a heating member heated by a heat source, an endless belt that is stretched and rotated by a plurality of members including the heating member, and the endless belt. A pressure member that presses against the heating member to form a nip portion, and a cooling means that cools the endless belt, and causes a recording material on which a toner image is formed to enter the nip portion. In the gloss imparting apparatus that conveys the nip portion in contact with the endless belt, the cooling means is provided on the inner peripheral side of the endless belt, and a part of the cooling means is in contact with the endless belt. The cooling belt is stretched between at least a driving roller to which a driving force is applied and a cooling roller for cooling the cooling belt, and the recording is performed on the cooling roller. Material The upstream side of the roller in the transport direction is obtained by said drive roller.

  According to the present invention, the cooling performance can be improved.

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 of a glossiness imparting device. It is explanatory drawing of the cooling mechanism of the cooling roller by a liquid cooling system. It is a schematic block diagram which shows the example of the conventional structure of a glossiness imparting apparatus. (A) It is sectional drawing of a cooling roller, (B) It is sectional drawing of a drive roller. It is explanatory drawing (1) of the multi-axis structure by which a cooling belt is stretched around three or more rollers. It is explanatory drawing (2) of a multi-axial structure by which a cooling belt is stretched around three or more rollers. It is explanatory drawing (3) of a multi-axial structure by which a cooling belt is stretched around three or more rollers. It is explanatory drawing (4) of the multi-axial structure by which a cooling belt is stretched around three or more rollers. It is a schematic top view of a glossiness imparting device. 10 is a schematic configuration diagram of a fixing device disclosed in Patent Document 3. FIG.

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

  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 the gloss imparting device main body 200 and is a separate device that can be connected to the image forming apparatus main body 100, but is not necessarily a separate device. The gloss applying device 300 may be provided on the downstream side of the fixing device.

(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 the static eliminating unit, 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 “gloss mode” is a mode that can be arbitrarily selected by the user by operating a button on the operation panel of the image forming apparatus main body 100. For example, an image that requires high gloss, such as a photographic image, is output. It is what is selected when you do.

(Glossing device)
Next, the configuration and operation of the gloss applying device will be described. FIG. 2 is a schematic configuration diagram illustrating an example of the gloss applying device.

  The gloss imparting apparatus according to this embodiment includes a heating member (gloss imparting heating roller 21) that is heated by a heat source (halogen heater 23), and an endless belt that is stretched and rotated around a plurality of members including the heating member ( Endless belt 24), a pressure member (gloss imparting pressure roller 22) that presses against the heating member via the endless belt to form a nip portion, and a cooling means (cooling means 40) for cooling the endless belt And a gloss imparting device that transports the recording material (recording material P) on which the toner image (toner image T) is formed into the nip portion and is brought into contact with the endless belt from the nip portion ( In the gloss imparting device 300), the cooling means is provided on the inner peripheral side of the endless belt, and includes a cooling belt (cooling belt 41) that rotates while part of the cooling belt is in contact with the endless belt. at least, It is stretched between a driving roller (driving roller 43) to which power is applied and a cooling roller (cooling roller 42) for cooling the cooling belt, and is an upstream roller in the recording material conveyance direction with respect to the cooling roller. Is a drive roller. In addition, the code | symbol in embodiment and the example of application are shown in a parenthesis.

  The gloss applying device 300 is stretched between a gloss applying heating roller 21 heated by a halogen heater 23 serving as a heat source, a gloss applying 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 while being heated by 21, a gloss imparting pressure roller 22 that presses against the gloss imparting heating roller 21 through the endless belt 24 to form a nip portion, and an endless belt A cooling belt 41 constituting a cooling means 40 for cooling the endless belt 24 is provided on the inner peripheral side of the endless belt 24, and the endless belt 24 rotates in the direction of the arrow as the driving roller 26 is driven to rotate. It is configured as follows.

  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, is cooled by the cooling means 40, and is peeled off from the endless belt 24. To do.

  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 a contact type thermistor, but a non-contact type thermopile may be used. On / off of the halogen heater 23 is controlled based on the temperature detection result of the temperature detection means 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 the side plate 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 the power source (AC power source), and further, the recording material P from the surface of the endless belt 24 heated by the gloss imparting heating roller 21. Heat is applied to the upper toner image T.

  The output control of the halogen heater 23 is performed based on the temperature detection result by the temperature detection means 25. 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 180 ° C.

  The gloss imparting pressure roller 22 has, for example, 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 a cylindrical metal roller. For example, a roller member in which a tube material of fluororesin having a thickness of 30 to 200 μm is formed.

  Further, the gloss imparting pressure roller 22 is pressed against the gloss imparting heating roller 21 via the endless belt 24 by a pressurizing mechanism to form a nip portion (gloss imparting nip portion). The width of the nip portion is set to about 10 to 40 mm, for example.

  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 driven to rotate at a peripheral speed of about 50 to 700 mm / second, for example, by the driving force of the driving roller 26 that is driven and controlled by the driving means.

  In the cooling means 40, a cooling belt 41 is stretched between a driving roller 43 and a cooling roller 42. The cooling belt 41 and the cooling roller 42 are rotationally driven at a predetermined speed by the driving force of the driving roller 43 that is driven and controlled by the driving means. The cooling roller 42 is provided on the downstream side in the conveyance direction of the recording material P, and the drive roller 43 is provided on the upstream side in the conveyance direction of the recording material P.

  The cooling belt 41 cools the endless belt 24 by contacting the inner peripheral surface of the endless belt 24, thereby cooling the toner image T of the recording material P conveyed in close contact with the endless belt 24. It is. In the example of FIG. 2, the cooling belt 41 cools the endless belt 24 immediately downstream of the nip portion between the gloss imparting heating roller 21 and the gloss imparting pressure roller 22, and further, Another cooling means 40 is provided on the downstream side to cool the endless belt 24.

  2 shows an example in which two cooling means 40 are provided on the inner circumference of the endless belt 24 along the conveyance direction of the recording material P, but depending on the configuration of the apparatus, the cooling means 40 is provided. May be one, or three or more. By providing a plurality of cooling means 40, the endless belt 24 can be efficiently cooled.

  The cooling unit 40 includes a liquid cooling unit that cools the cooling roller 42 by a liquid cooling method. The cooling roller 42 includes a pump 46 that circulates the cooling liquid through the cooling roller 42 and a cooling unit that circulates the cooling liquid. A radiator 44 and a tank 45 for storing a coolant are provided, and each is connected by a tube 47. Then, in the cooling means 40, the coolant circulates in the direction of the arrow shown in FIG. 2, and the cooling roller 42 is cooled.

The radiator 44 is provided with a fan for air-cooling and exhausting the coolant flowing in the radiator 44. The fan is configured, for example, as a cooling adjustment means that can adjust the cooling amount by changing the air volume in the range of 0 to 11 m ³ / min.

  The pump 46 is configured as a flow rate adjusting means that can vary the flow rate of the liquid sent from the tank 45 toward the cooling roller 42 within a range of, for example, 0 to 15 liters / minute.

  FIG. 3 is an explanatory diagram of the cooling mechanism of the cooling roller 42 by the liquid cooling method. In the present embodiment, an example in which a rotary joint is used as the cooling mechanism of the cooling roller 42 will be described. However, the cooling mechanism of the cooling roller 42 is not limited to this.

  The cooling roller 42 includes a roller main body 421 made of a metal hollow member, a supply pipe 422 that is disposed inside the roller main body 421 and supplies a cooling liquid, and a rotary joint 423. A plurality of supply holes 424 are provided in a portion of the supply pipe 422 that enters the roller main body 421. Reference numeral 427 indicates a bearing of the rotary joint 423, and reference numeral 428 indicates an O-ring that is a sealing member of the rotary joint 423.

  The coolant supplied from the rotary joint 423 by the pump 46 shown in FIG. 2 (arrow A in FIG. 3) is supplied into the roller body 421 from the supply hole 424 through the supply pipe 422 (arrow I). Then, the coolant filled in the roller body 421 enters the discharge path 426 of the rotary joint 423 from the discharge port 425 by the supply pressure of the pump 46 (discharged by the arrow B).

  The discharged coolant is introduced into the radiator 44 shown in FIG. 2, cooled by a fan installed in the radiator 44, and supplied again from the rotary joint 423 by the pump 46 (arrow A). In this way, the cooling roller 42 keeps the temperature of the cooling roller 42 at a constant temperature by taking the heat from the cooling belt 41 and removing the heat of the cooling roller 42 whose temperature has been raised by the cooling liquid and carrying it out of the cooling roller 42. Therefore, the cooling belt 41 and the endless belt 24 can be efficiently cooled.

(Glossing 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 cooling means 40 and is peeled from the endless belt 24 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 discharged to a paper discharge tray of the gloss imparting device 300. The glossiness of the image obtained by the glossiness imparting device 300 is, for example, a value of 65-80 with a 20 ° glossiness value.

  As described so far, the gloss imparting apparatus 300 according to the present embodiment employs a method of cooling the endless belt 24 by bringing the cooling belt 41 into contact with the endless belt 24 and cooling it. As a result, the time during which the endless belt 24 is in contact with the cooling belt 41 can be increased, and cooling can be performed efficiently.

  At this time, the endless belt 24 and the cooling belt 41 are rotated at the same speed, so that the same position of each belt is conveyed while being in contact.

  FIG. 4 is a schematic configuration diagram illustrating an example of a conventional configuration of the gloss providing device. The same members as those in FIG. 2 are denoted by the same reference numerals. 4 has a cooling member 90, 91, 92 for cooling the endless belt 24 as a metal fixing member, and slides with the endless belt 24 to cool the endless belt 24. An example is shown.

  As shown in FIG. 4, when the cooling members 90, 91, 92 are metal fixing members, the endless belt 24 and the cooling members 90, 91, 92 slide, so that the inner surface of the endless belt 24 is worn. Wear powder may be generated, and the endless belt 24 may not have a sufficient life due to a decrease in the thickness of the endless belt 24.

  On the other hand, in the gloss imparting apparatus 300 according to the present embodiment, the endless belt 24 and the cooling belt 41 are rotated at the same speed so as not to slide, and the occurrence of wear of the endless belt 24 is suppressed. Can do. Thereby, the lifetime of the endless belt 24 can be extended.

(Arrangement of cooling roller and drive roller)
Hereinafter, the arrangement of the cooling roller 42 and the driving roller 43 will be described in detail.

  In the example illustrated in FIG. 2, the gloss imparting device 300 includes two cooling units 40, and each cooling belt 41 is stretched by two rollers. In each cooling unit 40, the upstream roller in the conveyance direction of the recording material P is a driving roller 43 that is driven and controlled by the driving unit, and the downstream roller is a cooling roller 42 that is driven by the driving roller 43.

  As described above, by installing the cooling roller 42 on the downstream side in the conveyance direction of the recording material P, the cooling belt 41 immediately after taking the heat of the endless belt 24 can be cooled. Can cool well.

  5 is an explanatory diagram of the cooling roller 42 and the driving roller 43, where (A) a sectional view of the cooling roller 42 and (B) a sectional view of the driving roller 43. As shown in FIG. 5A, the surface layer of the cooling roller 42 is a metal layer 42a. As a material of the cooling roller 42, a general-purpose metal can be considered, and iron, aluminum, copper, etc. can be used, for example.

  As shown in FIG. 5B, the driving roller 43 has a rubber layer 43b on the surface of the metal layer 43a. As a material of the driving roller 43, a rubber layer 43b having a thickness of 0.5 mm to 20 mm, for example, silicone rubber, fluorine rubber, or the like can be used on a general metal surface.

  Thus, by leaving the surface layer of the cooling roller 42 as the metal layer 42a, the cooling roller 42 does not have a heat insulating layer such as a rubber layer and comes into contact with the cooling belt 41. The heat of 41 can be efficiently transmitted to the cooling roller 42 to cool the cooling belt 41. Moreover, the driving roller 43 can convey the cooling belt 41 at a constant speed without generating a slip with the cooling belt 41 by using the rubber layer 43b as a surface layer. Therefore, the cooling belt 41 and the endless belt 24 can be conveyed at the same speed, and the endless belt 24 can be efficiently cooled without any speed difference between the belts.

  As described above, according to the gloss imparting device 300 according to the present embodiment, the cooling belt 41 as the cooling means 40 rotates while being in contact with the endless belt 24, so that the endless belt 24 is efficiently cooled. can do. At this time, among the rollers on which the cooling belt 41 is stretched, the upstream roller in the transport direction is the driving roller 43, and the downstream roller is the cooling roller 42. The cooling belt 41 can be cooled, and the cooling belt 41 and the endless belt 24 can be efficiently cooled.

  In addition, if the roller that stretches the cooling belt 41 does not include the driving roller 43 and the cooling roller 42 is driven to rotate following the endless belt 24, the cooling roller 42 may slip. However, according to the gloss imparting device 300 according to this embodiment, the cooling belt 41 and the endless belt 24 can be efficiently cooled without causing the cooling roller 42 to slip. .

  Hereinafter, other embodiments of the gloss imparting apparatus 300 according to the present invention will be described. In addition, the description about the same point as the said embodiment is abbreviate | omitted suitably.

  Although FIG. 2 shows an example of a two-axis configuration in which the cooling belt 41 is stretched between two rollers, the cooling belt 41 may have a multi-axis configuration that is stretched between three or more rollers. For example, as shown in FIG. 6, when the cooling belt 41 is stretched around four rollers along the conveyance direction of the recording material P, the two intermediate rollers 48 may be used as the cooling rollers 42. Since the two rollers 48 have a small contact area with the cooling belt 41, it can be said that the cooling efficiency is not good. Therefore, as shown in FIG. 6, it is preferable that the most downstream roller is the cooling roller 42 and the most upstream roller is the drive roller 43.

  Since the cooling efficiency increases as the area where the cooling roller 42 contacts the cooling belt 41 increases, as shown in FIG. 2, rather than providing one multi-axis cooling means 40 as shown in FIG. The cooling efficiency is better when a plurality of two-axis cooling means 40 are provided.

  Further, in a multi-axis configuration in which the cooling belt 41 is stretched by three or more rollers, by adjusting the grip force (friction force) of the inner peripheral surface of the cooling belt 41 and the driving roller 43, for example, FIG. As shown, the driving roller 43 can be provided in the middle. In this case, not only the downstream side in the transport direction but also the upstream side roller can be used as the cooling roller 42. As a result, the two rollers having a wide contact area with the cooling belt 41 can be used as the cooling roller 42, so that the cooling efficiency can be further improved.

  In addition, the example in which the roller that stretches the cooling belt 41 is in contact with (contacts) the endless belt 24 with the cooling belt 41 interposed therebetween is shown. However, the cooling belt 41 is a roller that stretches the cooling belt 41. It may include a roller that does not contact the endless belt 24 via the belt.

  For example, as shown in FIG. 8, some of the rollers (here, the roller 49) that stretch the cooling belt 41 are provided at positions where the cooling belt 41 is not in contact with the endless belt 24. May be. In the example of FIG. 8, the upstream roller in the conveying direction that contacts the endless belt 24 with the cooling belt 41 in between is the driving roller 43, and the downstream roller is the cooling roller 42. In this case, the roller 49 is also preferably the cooling roller 42. Alternatively, the roller 49 may be the driving roller 43, and the upstream and downstream rollers in the transport direction may be the cooling roller.

  FIG. 9 shows an example in which the cooling belt 41 is stretched around four rollers, the upstream roller in the transport direction is used as the driving roller 43, and the three downstream rollers are used as the cooling roller 42. In the example of FIG. 9, since any of the cooling rollers 42 can have a large contact area with the cooling belt 41, the cooling efficiency can be further improved. In the example of FIG. 9, all the three downstream rollers are the cooling rollers 42, but it is needless to say that not all the cooling rollers 42 may include tension rollers.

  Moreover, although the example in which the roller diameters of the rollers over which the cooling belt 41 is stretched has been shown to be approximately the same, the roller diameters of the respective rollers may be different. For example, by making the roller diameter of the cooling roller 42 larger than that of the other rollers, the contact area with the cooling belt 41 can be increased, and the cooling efficiency can be further improved.

  Further, in order to improve the cooling performance of the gloss imparting device, in the gloss imparting device (gloss imparting device 300), the cooling means (first cooling means 40A, second cooling means 40B) are endless belts (endless belts). 24) are provided along the conveying direction of the recording material (recording material P), and are stretched between a cooling roller (cooling rollers 42A and 42B) and a plurality of rollers including the cooling roller. A cooling belt (cooling belts 41A and 41B) that rotates in a state in which the section is in contact with the endless belt, and supplies the liquid to the inside of the cooling roller from the liquid cooling means inside the cooling roller Holes (supply holes 424A and 424B) are provided, and the formation position of the supply holes is preferably different for each cooling roller. In addition, the code | symbol in embodiment and the example of application are shown in a parenthesis.

  As shown in FIG. 3, the roller main body 421 of the cooling roller 42 is provided with a plurality of supply holes 424 that serve as coolant supply ports. Hereinafter, a preferable form of the supply hole 424 of the cooling roller 42 will be described.

  FIG. 10 is a top view of the gloss applying device 300 shown in FIG. Note that illustration of some members is omitted for simplicity of explanation. In FIG. 10, the cooling means 40 on the upstream side in the transport direction is the first cooling means 40A, the cooling means 40 on the downstream side is the second cooling means 40B, and the reference numerals for the configurations of the respective cooling means are similarly A and B. Is attached.

  The rotary joint 423A that supplies the liquid to be cooled to the cooling roller 42A of the first cooling means 40A is provided on the front side of the gloss imparting device 300 (refers to the front side of FIG. 2 and the lower side of FIG. 3). The supply hole 424A is provided on the back side of the supply pipe 422A (refers to the back side of the drawing in FIG. 2 and the upper side in FIG. 3). The supply hole 424 </ b> A is preferably provided at 360 degrees along the inner peripheral surface of the cooling roller 42.

  In the first cooling means 40A, a cooling liquid for cooling the cooling roller 42A is supplied to the back side of the gloss imparting device 300, and a flow path is formed from the back side to the front side inside the cooling roller 42A. Discharge.

  In the first cooling means 40A, the temperature of the coolant supplied from the back increases as it goes to the near side while taking the heat of the cooling roller 42A. For this reason, the temperature of the cooling roller 42A is also lower on the back side than the front side, and the temperature of the endless belt 24 is also easier to cool on the back side, and the temperature on the back side becomes lower.

  On the other hand, the rotary joint 423B that supplies the liquid to be cooled to the cooling roller 42B of the second cooling means 40B is provided on the back side of the gloss imparting device 300, and the supply hole 424B is provided on the front side of the supply pipe 422B. ing. The supply hole 424 </ b> B is preferably provided at 360 degrees along the inner peripheral surface of the cooling roller 42.

  In the second cooling means 40B, a cooling liquid for cooling the cooling roller 42B is supplied to the front side of the gloss imparting device 300, and a flow path is formed from the front side to the back side inside the cooling roller 42B. Discharge.

  In the second cooling means 40B, the temperature of the coolant supplied from the labor side becomes higher as it goes away while taking heat from the cooling roller 42B. For this reason, the temperature of the cooling roller 42B is lower on the near side than on the far side.

  The endless belt 24 that has reached the second cooling means 40B is conveyed in a state where the back side temperature is low and the near side temperature is high in the first cooling means 40A. Then, the second cooling means 40B cools the front side from the back side, so that the temperature of the endless belt 24 can be made substantially uniform in the longitudinal direction (width direction of the recording material P). Unevenness of the glossiness of the recording material P can be eliminated.

  That is, in the two cooling means 40A and 40B shown in FIG. 10, since the cooling liquid is supplied from the opposite directions in the longitudinal direction of the cooling roller 42, the flow paths of the respective cooling liquids are in the opposite directions, and the respective cooling means The endless belt 24 can be uniformly cooled with the temperature unevenness in the longitudinal direction of the roller 42 and the cooling belt 41 as reverse directions.

  Further, in the configuration using the rotary joint 423, the supply side and the discharge side of the coolant are the same side. Therefore, by providing the supply hole 424 on the side opposite to the setting side of the rotary joint 423, the coolant is supplied to the rotary joint 423. Is supplied from the opposite side, and a flow path is formed on the rotary joint 423 side, whereby the entire region in the longitudinal direction of the cooling roller 42 can be cooled.

  The positions of the supply hole 424A and the supply hole 424B are preferably symmetrical with respect to the center line L in the longitudinal direction. By adopting such a positional relationship, the unevenness of cooling in the longitudinal direction of the gloss applying device 300 can be further eliminated, and the endless belt 24 can be uniformly cooled.

  The number of supply holes 424A and supply holes 424B is preferably the same. By making the number of the supply holes 424 for supplying the cooling liquid the same between the cooling means 40, the cooling performance of each cooling means 40 is made equal, and the cooling unevenness in the longitudinal direction of the gloss imparting device 300 is further eliminated. The endless belt 24 can be uniformly cooled.

  In addition, in FIG. 10, although the case where the two cooling means 40 was provided was demonstrated to the example, the number of the cooling means 40 should just be plural, and is not restricted to two.

  Further, in the above configuration in which the form of the supply hole 424 is different for each cooling means 40, the configuration of the roller on which the cooling belt 41 of the gloss imparting device 300 is stretched includes the driving roller 43 and the cooling roller 42. For example, the roller on which the cooling belt 41 is stretched may not include the driving roller 43, and the cooling belt 41 may be driven and rotated by the endless belt 24. Further, when the cooling belt 41 is stretched around the driving roller 43 and the cooling roller 42, the positional relationship between the driving roller 43 and the cooling roller 42 is not limited to the above-described example.

  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 members 40, 40A, 40B cooling means 41, 41A, 41B cooling belts 42, 42A, 42B cooling rollers 43, 43A, 43B driving roller 44 radiator 45 Tank 46 Pump 47 Tube 48 Roller 49 Roller 100 Image forming apparatus main body 200 Gloss applying apparatus main body 300 Gloss applying apparatus 421 Roller main body 422, 422A, 422B Supply pipe 423, 423A, 423B Rotary joint 424, 424A, 424B Supply hole 425 Exhaust Exit 426 Discharge path 427 Bearing 428 O-ring D Document P Recording material T Toner image

JP 2005-292578 A JP 2007-121653 A JP2013-92646A

Claims (16)

A heating member heated by a heat source;
An endless belt that is stretched and rotated around a plurality of members including 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,
In the gloss imparting apparatus that causes the recording material on which the toner image is formed to enter the nip portion and conveys the recording material in contact with the endless belt from the nip portion,
The cooling means is
A cooling belt which is provided on the inner peripheral side of the endless belt and rotates while part of the endless belt is in contact with the endless belt;
The cooling belt is stretched between at least a driving roller to which a driving force is applied and a cooling roller for cooling the cooling belt,
A gloss applying device, wherein the driving roller is a roller on the upstream side in the conveying direction of the recording material with respect to the cooling roller. A heating member heated by a heat source;
An endless belt that is stretched and rotated around a plurality of members including 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,
In the gloss imparting apparatus that causes the recording material on which the toner image is formed to enter the nip portion and conveys the recording material in contact with the endless belt from the nip portion,
The cooling means is
A plurality of the endless belts are provided along the conveying direction of the recording material on the inner peripheral side of the endless belt,
A cooling roller, and a cooling belt that is stretched around a plurality of rollers including the cooling roller and that rotates while part of the cooling roller is in contact with the endless belt,
A supply hole for supplying liquid from the liquid cooling means to the inside of the cooling roller is provided inside the cooling roller,
The gloss applying device, wherein the supply hole is formed at a different position for each cooling roller. The cooling means is
A plurality are provided along the conveyance direction of the recording material,
A supply hole for supplying liquid from the liquid cooling means to the inside of the cooling roller is provided inside the cooling roller,
The gloss applying apparatus according to claim 1, wherein a position where the supply hole is formed is different for each cooling roller.   The gloss applying device according to claim 1, wherein the cooling roller is in contact with the endless belt via the cooling belt. The cooling belt is stretched between three or more rollers,
5. The roller according to claim 1, wherein the most downstream roller in the conveying direction of the recording material is the cooling roller, and the most upstream roller is the driving roller. The gloss imparting device described. The cooling belt is stretched between three or more rollers,
5. The gloss applying apparatus according to claim 1, wherein another cooling roller is provided on the upstream side of the driving roller. The cooling belt is stretched between three or more rollers,
The roller on the uppermost stream side in the conveying direction of the recording material among the rollers is used as the driving roller, and two or more cooling rollers are provided on the downstream side of the driving roller. 4. The gloss imparting apparatus according to any one of 4 above.   The gloss applying apparatus according to claim 1, wherein a plurality of the cooling units are provided along a conveyance direction of the recording material.   9. The gloss applying apparatus according to claim 1, wherein the driving roller and the cooling roller have different surface layers.   10. The gloss applying device according to claim 1, wherein a surface layer of the driving roller is a rubber layer, and a surface layer of the cooling roller is a metal layer.   11. The gloss applying apparatus according to claim 1, wherein the cooling roller is cooled by a liquid cooling means having a rotary joint.   The said supply hole contains the said cooling roller provided in the one end side in the longitudinal direction of the said cooling roller, The said cooling hole provided in the other end side in the said longitudinal direction, The cooling roller characterized by the above-mentioned. Item 4. The gloss imparting device according to Item 2 or 3.   The gloss application according to claim 2, 3 or 12, wherein the supply hole is provided between the cooling rollers at a position symmetrical with respect to a center line in a longitudinal direction of the cooling roller. apparatus.   14. The gloss applying apparatus according to claim 2, wherein the number of the supply holes is the same for all the cooling rollers.   The liquid cooling means includes a rotary joint, and the rotary joint is provided on the opposite side to the supply hole in the longitudinal direction of the cooling roller. 14. The gloss applying device according to any one of 14 to 14.   An image forming apparatus comprising the gloss applying device according to claim 1 so as to be connectable to the inside or the outside thereof.