JP2019105760A - Image forming apparatus and glossiness reduction device - Google Patents

Abstract

To provide an image forming apparatus and a glossiness reduction device that can remove a toner remaining on a roller for reducing the glossiness of an image without reducing productivity.SOLUTION: An image forming apparatus comprises: an image forming unit that forms an image on a sheet; a fixing unit 43 that fixes the image formed by the image forming unit to the sheet; and a glossiness reduction unit 45 that reduces the glossiness of the image fixed by the fixing unit 43. The glossiness reduction unit 45 includes a rugged roller 451 that roughens the surface of the image, a pressure roller 452 that passes the sheet through a nip N formed by pressing the rugged roller 451, a web 456 that cleans the rugged roller 451, and a backup roller 453 that presses the web 456 against the rugged roller. The web 456 is to remove an attachment attached to the rugged roller 451 and is softer than the rugged roller 451 and backup roller 453.SELECTED DRAWING: Figure 2

Description

  The present disclosure relates to an image forming apparatus and a gloss reduction apparatus.

  2. Description of the Related Art In recent years, image forming apparatuses in which functions such as copying, network printing, faxing, and scanning are integrated have become widespread. Also, conventionally, the image formed by the fixing unit provided in the image forming apparatus may have a gloss. Therefore, as a device for reducing the gloss of the image on the downstream side of the fixing unit, a device provided with a roughening roller (for example, see Patent Document 1) has been proposed. In addition, it has also been proposed that the surface roughness of the toner image is increased so as to approach the surface property of the heating roller by softening the toner image by the heating roller that reduces the gloss of the image on the downstream side of the fixing unit. See, for example, Patent Documents 2 and 3). In addition, as what removes the toner etc. which adhered to a fixing roller, what removes a toner etc. from a roller with a web is proposed (for example, refer patent documents 4-7).

Japanese Patent Application Laid-Open No. 11-084770 JP, 2009-008709, A Japanese Patent Application Laid-Open No. 09-265243 Unexamined-Japanese-Patent No. 2003-255745 Japanese Patent Application Laid-Open No. 2002-258657 JP, 2009-008996, A JP 2008-129279 A

  In the prior art as described in Patent Document 1, when the toner adheres to the roughening roller when reducing the gloss of the image, the roughening roller becomes dirty. In the prior art as described in Patent Documents 2 and 3, when the toner adheres to the heating roller when reducing the gloss of the image, the heating roller is stained. Therefore, depending on the stain condition, it is necessary to remove the toner. However, in the prior art as described in Patent Documents 4 to 7, the toner attached to the fixing roller is removed by the web, and the toner attached to the roller is reduced by the web for reducing the gloss of the image. It is not something to be done. The roller for reducing the gloss of the image has more irregularities on the surface than the fixing roller, so it can not remove the toner attached as in the case of the fixing roller having a sufficiently smooth surface. Therefore, in order to reduce the adhesion of the toner, it is necessary to heat the temperature of the toner to a temperature higher than the softening point and then to clean it, which is a situation where the productivity is lowered.

  The present disclosure has been made in view of such a situation, and it is possible to remove the toner remaining on the roller that reduces the gloss of the image without reducing the productivity.

  An image forming apparatus according to a first aspect of the present disclosure includes an image forming unit that forms an image on a sheet, a fixing unit that fixes the image formed by the image forming unit to the sheet, and the fixing unit A gloss reduction portion for reducing the gloss of the image fixed on a sheet, the gloss reduction portion including an uneven roller for roughening the surface of the image, a pressure roller for pressing the uneven roller, and the uneven roller And a backup roller pressing the web against the concavo-convex roller, wherein the web passes through a nip formed between the concavo-convex roller and the pressure roller when the paper passes It cleans the deposit adhering to the uneven roller, and is softer than the uneven roller and the backup roller.

  Moreover, it is preferable that the said uneven | corrugated roller is comprised so that the surface may be uneven | corrugated shape, and the thickness width of the said web is larger than the largest height in the surface roughness of the said uneven | corrugated roller.

  Moreover, it is preferable that the amount of crushing of the said backup roller is larger than the largest height in the surface roughness of the said uneven | corrugated roller.

  Further, it is preferable that the hardness of the backup roller is larger than the hardness of the state in which the web is put on the backup roller and smaller than the hardness of the concavo-convex roller.

  Further, the difference between the hardness of the backup roller and the hardness of the state in which the web is covered on the backup roller is larger than 5 and the MD-1 hardness (Type C) of the surface of the backup roller is 60 It is preferable that it is more than one degree.

  Moreover, it is preferable that the said web is 30 g or more in basis weight, and is comprised from a fiber.

  The web preferably has a stiffness of 0.4 or less.

  A gloss reducing apparatus according to a second aspect of the present disclosure is a gloss reducing apparatus for reducing the gloss of an image fixed to a sheet, comprising: a concavo-convex roller for roughening the surface of the image; A pressing roller, a web for cleaning the uneven roller, and a backup roller pressing the web against the uneven roller, wherein the web is a nip formed between the uneven roller and the pressing roller To clean the deposit adhering to the uneven roller when the sheet passes through, and is softer than the uneven roller and the backup roller.

  According to the first and second aspects of the present disclosure, it is possible to remove the toner remaining on the roller that reduces the gloss of the image without reducing the productivity.

FIG. 1 is a diagram showing an example of the overall configuration of an image forming apparatus 1 according to an embodiment to which the present disclosure is applied. FIG. 6 is a view showing an example of the configuration of a fixing unit 43 and a gloss reducing unit 45 according to an embodiment to which the present disclosure is applied. It is a figure explaining the crushing amount S of the backup roller 453 in the gloss reduction part 45 which concerns on embodiment to which this indication is applied. It is a figure showing roughly an example of shape of web 456 when web 456 is pressed against concavo-convex roller 451 by backup roller 453 in gloss reduction part 45 concerning an embodiment to which this indication is applied. It is a figure which shows an example of the cleaning time according to the micro hardness of the backup roller 453 in the gloss reduction part 45 which concerns on embodiment to which this indication is applied, and the micro hardness of the state which covered the web 456 on the backup roller 453. It is a figure which shows an example of the cleaning time according to the hardness of the backup roller 453 in the gloss reduction part 45 which concerns on embodiment to which this indication is applied. It is a figure showing an example of cleaning time according to basic weight of web 456 concerning an embodiment to which this indication is applied. FIG. 16 is a diagram showing an example of a configuration of a conventional fixing unit 73. FIG. 17 schematically shows an example of the shape of web 756 when web 756 is pressed against fixing roller 731 by conventional backup roller 753.

  Hereinafter, although an embodiment of the present invention is described based on a drawing, the present invention is not limited to the following embodiment.

  FIG. 1 is a view showing an example of the overall configuration of an image forming apparatus 1 according to an embodiment to which the present disclosure is applied. The image forming apparatus 1 includes a reading unit 11 and an image forming apparatus main body 19. The reading unit 11 includes an ADF 11A and a document reading unit 11B. The ADF 11A includes a document tray, a sheet passing path, a sheet discharge tray, a contact type image sensor, a density reference member, and the like. The density reference member is used at the time of shading correction of the ADF 11A. The document reading unit 11B includes a document illumination unit, a reflection mirror, a condenser lens, a sensor, a platen glass, and the like. The reading unit 11 separates the document set in the document tray one by one and feeds it out, conveys it in the sub-scanning direction along the sheet passing path where the contact type image sensor is disposed, and discharges it to the sheet discharge tray. To paper. The document illumination unit includes a lamp and a mirror. While the document is conveyed in the sub-scanning direction along the sheet passing path, the reading operation in units of lines in the main scanning direction is repeatedly performed by the document illumination unit, the reflection mirror, the condenser lens, and the sensor.

  The image forming apparatus main body 19 includes an image forming unit 41, a fixing unit 43, a gloss reducing unit 45, a sheet feeding unit 61, and the like. The image forming unit 41 includes an exposure device 51, a developing device 53, a photosensitive drum 55, and a transfer belt 57, and forms a toner image for each color of Y, M, C, and K. The image forming unit 41 supplies toner T of a different color to the photosensitive drum 55 by the exposure device 51 based on the image data of the document read by the reading unit 11 and develops the same. The image forming unit 41 forms an image on a sheet by transferring the toner image developed on the photosensitive drum 55 onto the sheet supplied from the sheet feeding unit 61 by the transfer belt 57. The image forming section 41 fuses the toner T of the toner image transferred onto the sheet by the fixing section 43, whereby the color image is fixed on the sheet. The gloss reduction unit 45 reduces the gloss of the image fixed on the sheet by the fixing unit 43, and functions as a gloss reduction device. The image forming apparatus main body 19 includes a control unit 101. The control unit 101 includes a ROM, a RAM, a CPU, and an I / O interface, and can be executed by the reading unit 11 and the image forming apparatus main body 19 by executing various programs stored in a storage unit (not shown). Implement various functions.

  FIG. 2 is a view showing a configuration example of the fixing unit 43 and the gloss reducing unit 45 according to the embodiment to which the present disclosure is applied. The fixing unit 43 and the gloss reducing unit 45 are controlled by the control unit 101 and driven by a drive motor or the like (not shown). The fixing unit 43 includes a fixing roller 431, a fixing belt 432, a heating roller 433 and a pressure roller 435. The fixing belt 432 is wound around a fixing roller 431 and a heating roller 433. The heating roller 433 incorporates a halogen heater 434. Thus, the heat of the halogen heater 434 is transmitted to the fixing belt 432 via the heating roller 433. The fixing roller 431 is pressed against the pressure roller 435 through the fixing belt 432 to form a nip N. The pressure roller 435 incorporates a halogen heater 436. Thus, in the nip N, not only the heat of the halogen heater 434 but also the heat of the halogen heater 436 is transmitted. A conveyance path 438 is configured along the sheet conveyance direction, and a conveyance roller 437 is provided on the downstream side of the conveyance path 438.

  The gloss reducing unit 45 includes an uneven roller 451, a pressure roller 452, a web 456, a backup roller 453, and the like. The unevenness roller 451 is, for example, blasted on an aluminum roller, and the surface layer is coated with a fluorine-based material. With such a configuration, the maximum height Rz of the surface roughness of the uneven roller 451 is adjusted to 50 μm. Accordingly, the surface of the concavo-convex roller 451 is configured to have a concavo-convex shape. The pressure roller 452 presses the uneven roller 451. Therefore, when the sheet passes through the nip N formed between the uneven roller 451 and the pressure roller 452, the surface of the image formed on the sheet is roughened by the uneven roller 451. For example, a halogen heater 457 is provided inside the unevenness roller 451 as a heat source. Therefore, if the image formed on the sheet is embossed with the concavo-convex shape of the surface of the concavo-convex roller 451 in a state where the toner layer on the image reaches a temperature above the glass transition point Tg of the toner T by the nip N, Since the surface of the image formed on the paper is roughened, the gloss of the image formed on the paper is reduced.

  If the temperature of the toner layer is equal to or higher than the glass transition point Tg, the toner T is deformed, but if it is less than the softening point of the toner T which is a temperature higher than the glass transition point Tg, the image formed on the paper is more than necessary It will not be ruined. For example, the temperature of the uneven roller 451 is detected by a temperature sensor 459 provided around the uneven roller 451 and is set to 80 ° C. by the halogen heater 457. That is, while the sheet is passing through the nip N, if the temperature of the toner layer on the image is equal to or higher than the glass transition point Tg and lower than the softening point, the uneven roller 451 is not soiled during normal image formation. However, when JAM occurs, if the toner T on the image is heated for a long time at the nip N, if the toner T gets in over the uneven roller 451, cleaning of the uneven roller 451 is required.

  Therefore, a web 456 for cleaning the uneven roller 451 is used. The web 456 is for cleaning deposits attached to the uneven roller 451 when the sheet passes through the nip N, and is softer than the uneven roller 451 and the backup roller 453. In the web 456, the thickness width w is larger than the maximum height Rz in the surface roughness of the concavo-convex roller 451. The web 456 is composed of fibers, can be impregnated with a liquid, and is composed of non-woven fabric of aramid fibers, non-woven fabric of polyester fibers, non-woven fabric of pulp, or non-woven fabric composed of mixed fibers of aramid fibers, polyester fibers, and pulp If it is a thing, it will not specifically limit. The web 456 is previously impregnated with, for example, silicone oil as a liquid for improving lubricity and thermal conductivity. The web 456 preferably has a stiffness of 0.4 or less. Therefore, the web 456 is not suitable for the one where the fibers are hardened with medicine or heat. Therefore, a dry method or a wet method is suitable as a method of forming the web 456. Moreover, as a bonding method of fibers, those bonded by a hydroentangling method are particularly preferable.

  The unused web 456 is wound around the former winding shaft 454, and the used web is wound around the winding shaft 455. The web 456 is pressed against the uneven roller 451 by the backup roller 453. The backup roller 453 presses the web 456 against the uneven roller 451 by the pressing force applied from the pressing member 458. The pressing member 458 includes an elastic member such as a spring and the backup roller 453 and the web 456 are pressed against the uneven roller 451 by the elastic member, whereby at least a part of the backup roller 453 and the web 456 is crushed. FIG. 3 is a view for explaining the crushing amount S of the backup roller 453 in the gloss reducing unit 45 according to the embodiment to which the present disclosure is applied. The amount of crushing S of the backup roller 453 is larger than the maximum height Rz of the surface roughness of the concavo-convex roller 451. Specifically, the inter-axial distance L between the concavo-convex roller 451 and the backup roller 453 is the sum of the radius rb of the concavo-convex roller 451, the thickness width w of the web 456 and the radius rc of the backup roller 453. However, it becomes narrower by the amount of crushing S. The shaking amount S is at least twice the maximum height Rz. The amount of crushing S may be equal to or greater than the maximum height Rz by using a constant load method such as a spring.

  FIG. 4 is a view schematically showing an example of the shape of the web 456 when the web 456 is pressed against the concavo-convex roller 451 by the backup roller 453 in the gloss reducing unit 45 according to an embodiment to which the present disclosure is applied. The hardness of the backup roller 453 is larger than the hardness of the state in which the web 456 is covered on the backup roller 453, and smaller than the hardness of the concavo-convex roller 451. FIG. 5 is a view showing an example of the cleaning time according to the micro hardness of the backup roller 453 in the gloss reduction unit 45 and the micro hardness in a state where the web 456 is covered with the backup roller 453 according to an embodiment to which the present disclosure is applied. It is. FIG. 8 is a view showing a configuration example of the conventional fixing unit 73. As shown in FIG. FIG. 9 schematically shows an example of the shape of the web 756 when the web 756 is pressed against the fixing roller 731 by the conventional backup roller 753.

  As a premise of measuring the cleaning time as shown in the example of FIG. 5, first, the paper on which the three-layer solid on which the toner T for each color of Y, M and C is applied is formed is jammed and heated for 1 minute By leaving the toner T to sufficiently adhere to the bottom of the concavo-convex shape of the concavo-convex roller 451, the toner T is made to enter on the concavo-convex roller 451. Next, the jammed paper is removed, and in a state where the web 456 is pressed against the concavo-convex roller 451 at the same temperature, the concavo-convex roller 451 is idle rotated, the cleaning operation is performed, and the cleaning time is measured. A plurality of measurements of the cleaning time are performed by changing the hardness of the web 456. That is, the cleaning time for each of the plurality of different webs of fabric 456 is measured.

  In the cleaning operation, if the temperature of the concavo-convex roller 451 is brought close to the softening point, the toner T approaches a molten state, so the cleaning time is shortened, but a heating time to approach the softening point and subsequent cooling time In fact, if it is heated at the time of cleaning, the productivity as a whole may be reduced. Further, it is preferable that the winding shaft 755 is not driven during the cleaning operation. By not driving the winding shaft 755, the web 456 slides on the surface of the uneven roller 451 while the uneven roller 451 is idle. The take-up shaft 755 is preferably driven according to the printing rate or according to the travel distance of the sheet. In addition, the winding shaft 755 may be driven between images. That is, it is preferable that a part of the web 456 be wound around the winding shaft 455 after a certain amount of load is applied.

  Specifically, as shown in FIG. 5, when the micro hardness of the backup roller 453 is taken on the horizontal axis and the micro hardness of the backup roller 453 is covered on the web 456 is taken on the vertical axis, Different features are shown for a_1 and for the area a_2 and the area a_3 below the 45 degree line. Since the thickness width w of the web 456 is at most about 1 mm and thin, in the normal hardness measurement method, it is affected by the substrate. Therefore, Type C of a microhardness tester MD-1 capa manufactured by Kobunshi Keiki Co., Ltd. is used. With this hardness tester, the surface pressure at the time of measurement is almost equal to the surface pressure range required for setting the web 456, and the hardness of minute portions can be measured. You can get it. That is, if the web 456 is softer than the backup roller 453, the result of comparing the hardness of the backup roller 453 and the hardness of the state in which the backup roller 453 is covered with the web 456 is that the backup roller 453 is covered with the web 456. The measured value of hardness is lower than the measured value of hardness of the backup roller 453. In the following description, the measurement result of micro hardness is described as hardness.

  The area a_1 corresponds to an operation result when the fixing unit 73 cleans with the web 756, since the area a_1 corresponds to one in which the hardness of the web 456 is higher than the hardness of the backup roller 453. The fixing unit 73 is controlled by the control unit 101 and driven by a drive motor (not shown) or the like, and includes a fixing roller 731 and a pressure roller 735 as shown in FIG. The fixing roller 731 incorporates a halogen heater 734. Thus, the heat of the halogen heater 734 is transmitted to the surface of the fixing roller 731. The fixing roller 731 is pressed against the pressure roller 735 to form the nip M. The pressure roller 735 incorporates a halogen heater 736. Thus, in the nip M, not only the heat of the halogen heater 734 but also the heat of the halogen heater 736 is transmitted. A conveyance path 738 is configured along the sheet conveyance direction, and a conveyance roller 737 is provided on the downstream side of the conveyance path 738. The fixing roller 731 is pressed against the web 756 by the backup roller 753. The backup roller 753 is pressed by the pressing member 758 against the web 756. The unused web 756 is wound around the former winding shaft 754 and the used web is wound around the winding shaft 755.

  In the configuration as described above, the web 756 is harder than the fixing roller 731 and the backup roller 753. The fixing roller 731 is harder than the backup roller 753. Therefore, in the area a_1 illustrated in FIG. 5, the backup roller 753 is crushed, so that the width of the nip M is increased and pressed. The surface roughness of the fixing roller 731 is approximately 5 μm or less. Even if the web 756 used in such a configuration is applied to the concavo-convex roller 451 and the concavo-convex roller 451 is idle rotated for 10 minutes or more, the web 756 is hard. It is difficult to follow the bottom, and it is difficult to clean the toner T attached to the uneven roller 451.

  Therefore, in order to clean the toner T attached to the concavo-convex roller 451, a configuration that corresponds to the area a_2 and the area a_3 is preferable. In the area a_2 and the area a_3, the web 456 is softer than the backup roller 453. Therefore, in the area a_2 and the area a_3, the web 456 can be crushed more than the backup roller 453 by collapsing the backup roller 453 into the concavo-convex shape of the concavo-convex roller 451 or more. As a result, since the shape of the web 456 can be made to follow the bottom of the concavo-convex shape of the concavo-convex roller 451 when the shape of the web 456 is deformed, the toner T at the bottom of the concavo-convex shape of the concavo-convex roller 451 is cleaned Can. Specifically, in the region a_2, the configuration of the gloss reducing unit 45 corresponds to one having a cleaning time of 300 seconds or less. On the other hand, in the area a_3, the configuration of the gloss reduction unit 45 corresponds to one in which the cleaning time is within 100 seconds. More specifically, in the region a_3, the configuration of the gloss reducing unit 45 corresponds to the configuration in which the difference between the hardness of the backup roller 453 and the hardness of the state where the backup roller 453 is covered with the web 456 is more than five.

  FIG. 6 is a diagram illustrating an example of the cleaning time according to the hardness of the backup roller 453 in the gloss reducing unit 45 according to the embodiment to which the present disclosure is applied. As shown in FIG. 6, as a result of measuring the cleaning time in each of the webs 456 of a plurality of different fabrics, in the configuration of the gloss reducing portion 45, the cleaning time is the case where the hardness of the backup roller 453 falls under 60 degrees. Saturate. That is, in the configuration of the gloss reducing portion 45, the difference between the hardness of the backup roller 453 and the hardness in the state where the web 456 is covered on the backup roller 453 is larger than 5 and the hardness of the surface of the backup roller 453 (Type C) is 60 degrees or more. With such a configuration, it is possible to remove the toner T at the bottom of the uneven shape of the uneven roller 451 by the web 456 by pressing the web 456 against the uneven roller 451 by the backup roller 453.

  FIG. 7 is a view showing an example of the cleaning time according to the basis weight of the web 456 according to the embodiment to which the present disclosure is applied. As shown in FIG. 7, as a result of measuring the cleaning time in each of the webs 456 of a plurality of different fabrics, the configuration of the gloss reducing portion 45 is such that the backup roller 453 has a hardness of 60 degrees or more. As shown in FIG. 7, when the web 456 has a basis weight of 30 g or more, sufficient fiber density is obtained when crushed, and the amount of fibers filled in the bottom of the concavo-convex shape of the concavo-convex roller 451 is also saturated. Therefore, the cleaning time is also saturated. That is, in the configuration of the gloss reducing portion 45, it is preferable that the web 456 has a basis weight of 30 g or more, and is made of fibers.

  From the above description, the web 456 is softer than the concavo-convex roller 451 and the backup roller 453. Therefore, since the web 456 is softer than the backup roller 453, if the web 456 is pressed against the uneven roller 451 by the backup roller 453, the web 456 is crushed and deformed more than the backup roller 453. Therefore, since the shape of the web 456 follows the uneven bottom of the uneven roller 451, the toner T remaining on the uneven roller 451 that reduces the gloss of the image can be removed without reducing the productivity.

  In addition, the thickness width w of the web 456 is larger than the maximum height Rz in the surface roughness of the concavo-convex roller 451. Accordingly, since the web 456 reaches the bottom of the uneven shape, the toner T at the bottom of the uneven shape can be cleaned by the web 456. Therefore, the toner T remaining on the concavo-convex roller 451 can be removed by the web 456.

  The crushing amount S of the backup roller 453 is larger than the maximum height Rz of the surface roughness of the uneven roller 451. Therefore, since the shape of the backup roller 453 can be crushed until it reaches the bottom of the uneven shape, the web 456 can follow the uneven shape. Therefore, the bottom of the uneven shape can be cleaned.

  Further, the hardness of the backup roller 453 is larger than the hardness of the state in which the web 456 is covered on the backup roller 453 and smaller than the hardness of the concavo-convex roller 451. Therefore, among the unevenness roller 451, the backup roller 453, and the web 456, the unevenness roller 451 is the hardest and the web 456 is the softest. Therefore, since the shape of the web 456 is crushed more than the shape of the backup roller 453 by crushing the shape of the backup roller 453 along the uneven shape of the concavo-convex roller 451, the shape of the web 456 is deformed by deforming the shape of the web 456. The bottom of the uneven shape can be made to follow.

  The difference between the hardness of the backup roller 453 and the hardness of the state where the web 456 is covered with the backup roller 453 is larger than 5 and the hardness (Type C) of the surface of the backup roller 453 is 60 degrees or more. is there. Therefore, by pressing the web 456 against the concavo-convex roller 451 by the backup roller 453, the shape of the web 456 can be surely crushed along the concavo-convex shape of the concavo-convex roller 451.

  Also, the web 456 has a basis weight of 30 g or more, and is made of fibers. Thus, the web 456 has a sufficient fiber density when the shape is crushed, so that the bottom of the uneven shape is sufficiently filled with the fiber amount of the fibers constituting the web 456. Therefore, the toner T at the bottom of the uneven shape can be sufficiently removed.

  Also, the web 456 has a stiffness of 0.4 or less. Therefore, even if the shape of the web 456 is crushed, the fibers constituting the web 456 are not compressed. Therefore, since the web 456 does not become harder than the backup roller 453, the cleaning property can be maintained.

  Although the image forming apparatus 1 to which the present disclosure is applied has been described based on the embodiment, the present disclosure is not limited to this, and changes may be made without departing from the scope of the present disclosure. For example, in the present embodiment, an example in which the maximum height Rz in the surface roughness of the concavo-convex roller 451 is 50 μm has been described, but the present invention is not limited thereto. The maximum height Rz is 10 to 70 μm It is also good.

Reference Signs List 1 image forming apparatus, 11 reading unit, 11A ADF, 11B document reading unit 19 image forming apparatus main body, 101 control unit 41 image forming unit, 43 fixing unit, 431 fixing roller, 432 fixing belt 433 heating roller, 434 halogen heater, 435 Pressure roller 436 heater, 437 conveyance roller, 438 conveyance path 45 gloss reduction portion, 451 uneven roller, 452 pressure roller 453 backup roller, 454 original winding shaft, 455 winding shaft 456 web, 457 halogen heater 458 pressing member, 459 Temperature sensor 51 exposure device, 53 developing device, 55 photosensitive drum, 57 transfer belt 61 sheet feeding portion 73 fixing portion, 731 fixing roller, 734 halogen heater 735 pressure roller, 736 halogen heater 737 conveying roller, 7 8 conveyance path 753 backup roller, 754 original winding shaft, 755 take-up shaft 756 web, 758 pressing member w thickness width, rb, rc radius, L-axis distance, S shake amount, Rz maximum height T toner, a_1 to a_3 Area, Tg glass transition point, N, M nip

Claims (8)

An image forming unit that forms an image on a sheet;
A fixing unit configured to fix the image formed by the image forming unit on the sheet;
A gloss reduction unit that reduces the gloss of the image fixed to the sheet by the fixing unit;
Equipped with
The gloss reduction unit is
An uneven roller that roughens the surface of the image;
A pressure roller for pressing the uneven roller;
A web for cleaning the uneven roller;
A backup roller pressing the web against the uneven roller;
Equipped with
The web is
It cleans the deposit adhering to the uneven roller when the sheet passes through the nip formed between the uneven roller and the pressure roller, and is more effective than the uneven roller and the backup roller. Be soft,
Image forming apparatus. The uneven roller is
The surface is configured in an uneven shape,
The web is
The thickness width is larger than the maximum height of the surface roughness of the concavo-convex roller,
An image forming apparatus according to claim 1. The backup roller is
The amount of shaking is larger than the maximum height of the surface roughness of the uneven roller,
The image forming apparatus according to claim 1. The hardness of the backup roller is
The hardness of the state in which the web is covered on the backup roller is larger than the hardness of the concavo-convex roller,
The image forming apparatus according to any one of claims 1 to 3. The difference between the hardness of the backup roller and the hardness of the state in which the web is covered on the backup roller is greater than 5 and the micro hardness (Type C) of the surface of the backup roller is 60 degrees or more ,
The image forming apparatus according to any one of claims 1 to 4. The web is
Basic weight is 30 g or more, and is composed of fibers,
The image forming apparatus according to any one of claims 1 to 5. The web is
Stiffness is less than 0.4,
The image forming apparatus according to claim 6. A gloss reducing device for reducing the gloss of an image fixed to a sheet, comprising:
An uneven roller that roughens the surface of the image;
A pressure roller for pressing the uneven roller;
A web for cleaning the uneven roller;
A backup roller pressing the web against the uneven roller;
Equipped with
The web is
It cleans the deposit adhering to the uneven roller when the sheet passes through the nip formed between the uneven roller and the pressure roller, and is more effective than the uneven roller and the backup roller. Be soft,
Gloss reduction device.

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