JP2011123275A - Fixing device and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fixing device configured such that, when an image recorded on embossed paper whose surface has irregularities is fixed, fixability is more satisfactory than the case where the image is fixed at the same temperature as that of regular paper, and to provide an image forming apparatus. <P>SOLUTION: The fixing device includes: a fixing belt 84 supported so as to be movable in circulation; a heat roll 89 for driving the fixing belt 84 in circulation; a pressure roll 88 pressed against the fixing belt 84 and sandwiching a sheet member P between the fixing belt 89 and the pressure roll; and halogen heaters 102, 104, and 106 for heating a transfer belt 84. When the recording medium is embossed paper, the heating temperature of the heating means is set higher than the case where the recording medium is regular paper or coated paper. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

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

  As a fixing device for fixing a toner image formed on a recording material, a fixing roll, a fixing belt stretched over the fixing roll, a stretching roll stretched over the fixing belt, and a pressure applied to the fixing roll A fixing member, and a fixing device including a fixing member and a peeling member arranged to press the outer surface of the fixing belt against the pressure member in the vicinity of the downstream side of the pressure member. Yes (Patent Document 1).

JP 2007-57682 A

  An object of the present invention is to provide a fixing device and an image forming apparatus that have better fixability when fixing an image recorded on embossed paper having irregularities on the paper surface than when fixing at the same temperature as plain paper. And

  According to the first aspect of the present invention, there is provided a fixing belt supported so as to be circulated, a driving means for circulatingly driving the fixing belt, and a recording medium sandwiched between the fixing belt and pressed against the fixing belt. A pressure roll; and a heating unit that heats the transfer belt. When the recording medium is embossed paper, the heating unit heats more than when the recording medium is plain paper or coated paper. The present invention relates to a fixing device whose temperature is set high.

  According to the second aspect of the present invention, when the recording medium is embossed paper, the feeding speed of the recording medium is set to be lower than when the recording medium is plain paper or coated paper. The fixing according to claim 1, wherein the fixing can be set to any one of an operation and a high-speed operation in which the recording medium is set to have the same feed speed when the recording medium is plain paper or coated paper. Relates to the device.

  According to a third aspect of the present invention, there is provided an image forming unit that forms an image on a recording medium, and a fixing device according to the first or second aspect that fixes an image formed on the recording medium by the image forming unit. The present invention relates to an image forming apparatus provided.

  According to the first aspect of the present invention, when fixing an image recorded on embossed paper having irregularities on the surface of the paper, a fixing device having better fixability than when fixing at the same temperature as plain paper is provided. The

  According to the second aspect of the present invention, there is provided a fixing device capable of selecting either low speed operation or high speed operation when the recording medium is embossed paper.

  According to the invention of claim 3, even when the recording medium is embossed paper, an image forming apparatus capable of fixing an image with high fixability to the recording medium as in the case where the recording medium is plain paper and coated paper. Is provided.

FIG. 1 is a schematic cross-sectional view showing the entire image forming apparatus according to an embodiment of the present invention. FIG. 2 is a side view showing an image forming unit provided in the image forming apparatus according to the embodiment of the present invention. FIG. 3 is a side view showing a fixing unit provided in the image forming apparatus according to the embodiment of the present invention.

  An example of a fixing device and an image forming apparatus according to an embodiment of the present invention will be described.

  As shown in FIG. 1, an image forming apparatus 10 according to the present embodiment forms a color image or a black and white image, and includes a first processing unit 10A and a first processing unit 10A arranged on the left side when viewed from the front. And a second processing unit 10B that is detachably disposed on the right side.

  Inside the second processing unit 10B, on the upper side in the vertical direction, includes an image signal processing unit that performs image processing on image data sent from the computer, and driving means that controls driving of each unit of the image forming apparatus 10 As an example, a control unit 13 is provided. A power supply unit 230 is provided below the control unit 13. The power supply unit 230 supplies power to each part of the image forming apparatus 10 by changing an alternating current taken from outside into a direct current. The second control unit 10 </ b> B further includes an input / output unit 300 that inputs various types of information to the control unit 13 and displays information output from the control unit 13.

  On the other hand, the first special color (V), the second special color (W), the yellow (Y), the magenta (M), the cyan (C), and the black are inside the first processing unit 10A and vertically upward. Toner cartridges 14V, 14W, 14Y, 14M, 14C, and 14K that store the respective toners (K) are provided so as to be replaceable in the horizontal direction. The first special color and the second special color are selected from special colors (including transparency) other than yellow, magenta, cyan, and black. Further, in the following description, when distinguishing V, W, Y, M, C, and K, an explanation is given by adding an alphabetic character of V, W, Y, M, C, or K after the number. When V, W, Y, M, C, and K are not distinguished, V, W, Y, M, C, and K are omitted.

  Under the toner cartridge 14, six image forming units 16, which are examples of image forming units corresponding to the toners of the respective colors, are provided side by side in a horizontal direction corresponding to the toner cartridges 14. On the lower side, an exposure unit 40 as an example of an image forming unit is provided for each image forming unit 16. The exposure unit 40 receives image data subjected to image processing from the control unit 13 described above, modulates a semiconductor laser (not shown) according to the color material gradation data, and emits exposure light L from these semiconductor lasers. It is comprised so that it may radiate | emit. Specifically, an electrostatic latent image is formed on the photoconductor 18 by irradiating the surface of the photoconductor 18 (see FIG. 2) described later with exposure light L corresponding to each color.

  As shown in FIG. 2, the image forming unit 16 includes a photoreceptor 18 that is driven to rotate in the direction of arrow A (clockwise in FIG. 2). A corona discharge method (non-contact charging method) scorotron charger 20 that charges the photosensitive member 18 and an exposure light L emitted by the exposure unit 40 are formed on the photosensitive member 18 around the photosensitive member 18. A developing device 22 that develops the electrostatic latent image with each color developer (toner), a cleaning blade 24 that cleans the surface of the photoreceptor 18 after the transfer, and a light that irradiates the surface of the photoreceptor 18 after the transfer. An erase lamp 26 is provided for performing static elimination. The scorotron charger 20, the developing device 22, the cleaning blade 24, and the erase lamp 26 are arranged in this order from the upstream side to the downstream side in the rotation direction of the photoconductor 18 so as to face the surface of the photoconductor 18. Yes.

  Further, the developing device 22 is disposed on the side of the image forming unit 16 (right side in the drawing in this embodiment), and a developer containing member 22A filled with a developer G containing toner and a developer containing member 22A. And a developing roll 22 </ b> B that moves the filled toner to the surface of the photoreceptor 18. The developer accommodating member 22A is connected to the toner cartridge 14 (see FIG. 1) through a toner supply path (not shown), and the toner is supplied from the toner cartridge 14.

  As shown in FIG. 1, a transfer unit 32 is provided below each image forming unit 16. The transfer unit 32 is disposed inside the intermediate transfer belt 34 and the endless intermediate transfer belt 34 that is in contact with each photoconductor 18, and the toner image formed on each photoconductor 18 is transferred to the intermediate transfer belt 34 in multiple transfers. And six primary transfer members 36 as primary transfer members. The intermediate transfer belt 34 includes a drive roll 38 driven by a motor (not shown), a tension applying roll 41 that adjusts the tension of the intermediate transfer belt 34, a support roll 42 that is disposed opposite to a secondary transfer roll 62 described later, It is wound around a plurality of support rolls 44 and is circulated and moved in the direction of arrow B (counterclockwise direction) in FIG.

  Specifically, each primary transfer roll 36 is disposed opposite to the photoreceptor 18 of each image forming unit 16 with the intermediate transfer belt 34 interposed therebetween. The primary transfer roll 36 is applied with a transfer bias voltage having a polarity opposite to the toner polarity by a power supply unit (not shown). With this configuration, the toner image formed on the photoreceptor 18 is transferred to the intermediate transfer belt 34. A cleaning blade 46 whose tip is in contact with the intermediate transfer belt 34 is provided on the opposite side of the drive roll 38 and the intermediate transfer belt 34. The cleaning blade 46 is disposed on the intermediate transfer belt 34 that circulates and moves. Residual toner and paper dust are removed.

  On the other hand, below the transfer unit 32, below the first processing unit 10A, two large paper feed cassettes 48 in which a sheet member P as an example of a recording medium is accommodated are provided in a horizontal direction. The sheet member P can be stored in large quantities. Since the two paper feed cassettes 48 have the same configuration, only one paper feed cassette 48 will be described, and description of the other paper feed cassette 48 will be omitted.

  The paper feed cassette 48 can be pulled out from the first processing unit 10A. When the paper feed cassette 48 is pulled out from the first processing unit 10A, the bottom plate 50 provided in the paper feed cassette 48 and on which the sheet member P is placed. However, it is lowered by an instruction from a control means (not shown). The user can replenish the sheet member P by lowering the bottom plate 50. Further, when the paper feed cassette 48 is attached to the first processing unit 10A, the bottom plate 50 is raised by an instruction from the control means. Above the one end side of the paper feed cassette 48, a feed roll 52 for sending the sheet member P from the paper feed cassette 48 to the transport path 60 is provided, and the uppermost sheet member P placed on the rising bottom plate 50 is provided. And the delivery roll 52 come into contact with each other. Further, a separation roll 56 that prevents double feeding of the sheet member P is provided on the downstream side (hereinafter simply referred to as “downstream side”) of the feeding roll 52 in the sheet member conveyance direction. A plurality of transport rolls 54 for transporting the member P downstream in the transport direction are provided.

  The conveyance path 60 provided on the upper side of the paper feed cassette 48 folds the sheet member P delivered from the paper feed cassette 48 to the opposite side (the left side in the drawing) at the first folding part 60A, and further at the second folding part 60B. It is folded back to the opposite side (the right side in the figure) and extends toward the transfer position T sandwiched between the secondary transfer roll 62 and the support roll 42.

  An aligner (not shown) for correcting the inclination or the like of the conveyed sheet member P is provided at a portion sandwiched between the second folding portion 60B and the transfer position T, and is sandwiched between the aligner and the transfer position T. In the part, an alignment roll 64 for adjusting the movement timing of the toner image on the intermediate transfer belt 34 and the conveyance timing of the sheet member P is provided.

  The secondary transfer roll 62 is applied with a transfer bias voltage having a polarity opposite to the toner polarity by a power supply unit (not shown). With this configuration, the color toner images transferred onto the intermediate transfer belt 34 are secondarily transferred onto the sheet member P conveyed along the conveyance path 60 by the secondary transfer roll 62. Further, a preliminary path 66 extending from the side surface of the first processing unit 10A is provided so as to join the second folding unit 60B of the transport path 60, and an external path disposed adjacent to the first processing unit 10A is provided. A sheet member P sent from a large-capacity stacking unit (not shown) can enter the conveyance path 60 through the preliminary path 66.

  On the other hand, on the downstream side of the transfer position T, there are provided a plurality of conveying devices 70 that convey the sheet member P to which the toner image has been transferred toward the second processing unit 10B. The conveying device 70 includes a plurality of belt members wound around a drive roll and a driven roll (not shown), and rotates the belt member by rotating the drive roll to direct the sheet member P toward the downstream side. It is designed to be transported.

  The downstream side of the conveying device 70 extends from the first processing unit 10A to the second processing unit 10B, and the sheet member P sent out by the conveying device 70 is received by the conveying device 80 provided in the second processing unit 10B. And is further conveyed downstream. A fixing unit 82 as an example of a fixing device in the present invention is provided on the downstream side of the conveying device 80.

  As shown in FIG. 3, the fixing unit 82 includes a fixing belt module 86 including a fixing belt 84, and a pressure roll 88 disposed in pressure contact with the fixing belt module 86. A nip portion N where a fixing belt 84 (fixing belt module 86), which will be described later, and a pressure roll 88 come into contact with each other is formed. In the nip portion N, the sheet member P is pressurized and heated to fix the toner image. A temperature sensor 85 that measures the surface temperature of the fixing belt 84 is provided in the vicinity of the fixing belt 84. The measurement result in the temperature sensor 85 is input to the control unit 13.

  The fixing belt module 86 includes an endless fixing belt 84, a heating roll 89 around which the fixing belt 84 is wound on the pressure roll 88 side, and rotationally driven by the rotational force of a motor (not shown). And a support roll 90 that stretches the fixing belt 84 from the inside at different positions. Further, a support roll 92 that is disposed outside the fixing belt 84 and defines a circulation path thereof, and a posture correction roll 94 that corrects the posture of the fixing belt 84 from the heating roll 89 to the support roll 90 are provided.

  Further, in the downstream area in the nip portion N where the fixing belt module 86 and the pressure roll 88 are in pressure contact with each other and on the inner side of the fixing belt 84, the outer circumference of the heating roll 89 is arranged. A peeling pad 96 for peeling the fixing belt 84 from the surface and a support roll 98 on which the fixing belt 84 is stretched on the downstream side of the nip portion N are provided.

  The heating roll 89 as an example of the driving means in the present invention is a hard roll having a 200 μm-thick fluororesin film formed on the core metal surface as a protective layer for preventing metal abrasion on the surface of the cylindrical metal core made of aluminum. It is a roll. Further, a halogen heater 102 is provided inside the heating roll 89. Further, the support roll 90 is a cylindrical roll formed of aluminum, and a halogen heater 104 is disposed inside as a heating source so as to heat the fixing belt 84 from the inner surface side. Further, spring members (not shown) that press the fixing belt 84 outward are disposed at both ends of the support roll 90.

  The support roll 92 is a cylindrical roll formed of aluminum, and a release layer made of a fluororesin having a thickness of 20 μm is formed on the surface of the support roll 92. This release layer is formed to prevent a slight amount of offset toner and paper dust from the outer peripheral surface of the fixing belt 84 from accumulating on the support roll 92. A halogen heater 106 is disposed inside the support roll 92 to heat the fixing belt 84 from the outer peripheral surface side. That is, in this embodiment, the fixing belt 84 is heated by the heating roll 89, the support roll 90, and the support roll 92. Halogen heaters 102, 104, and 106 are examples of the heating means in the present invention.

  The posture correction roll 94 is a cylindrical roll formed of aluminum, and an end position measuring mechanism (not shown) for measuring the end position of the fixing belt 84 is disposed in the vicinity of the posture correction roll 94. . The posture correcting roll 94 is provided with an axial displacement mechanism (not shown) that displaces the contact position in the axial direction of the fixing belt 84 according to the measurement result of the end position measuring mechanism. Configured to control.

  Moreover, the peeling pad 96 is a block-shaped member having a length corresponding to the heating roll 89 formed of a rigid body such as an iron-based metal or resin, for example. The cross-sectional shape of the peeling pad 96 has a curved inner surface 96A facing the heating roll 89, a pressing surface 96B that presses the fixing belt 84 toward the pressing roll 88, and an angle determined with respect to the pressing surface 96B. And has an outer surface 96 </ b> C that bends the fixing belt 84 and has a substantially arc shape. Specifically, the corner portion U composed of the pressing surface 96B and the outer surface 96C bends the fixing belt 84 pressed against the corner portion U by the pressure roll 88, and the leading end of the sheet member P passes through the corner portion U. In doing so, the leading edge of the sheet member P and the fixing belt 84 are peeled off.

  On the other hand, the pressure roll 88 has a structure in which a cylindrical roll 88A made of aluminum is used as a base, and an elastic layer 88B made of silicone rubber and a release layer made of a fluororesin having a thickness of 100 μm are laminated in this order from the base. It has become. The pressure roll 88 is rotatably supported and is provided in pressure contact with a portion where the fixing belt 84 is wound around the heating roll 89 by a biasing means such as a spring (not shown). As a result, as the heating roll 89 of the fixing belt module 86 rotates in the direction of arrow C, the heating roll 89 rotates in the direction of arrow E following the heating roll 89.

  Further, the peripheral speed v of the heating roll 89 and the heating temperature t in the halogen heaters 102, 104, 106 are controlled by the control unit 13 as an example of a control means. The surface temperature of the fixing belt 84 is input from the temperature sensor 85 to the control unit 13.

  When the sheet member P is a paper having a smooth surface such as plain paper or coated paper, as shown in Table 1 above, the peripheral speed v of the heating roll 89 is V1, for example, 445 mm / s in the control unit 13. The heating temperature t in the halogen heaters 102, 104, 106 is controlled so that the surface temperature of the fixing belt 84 is T1, for example, 150 to 180 ° C.

  On the other hand, when the user inputs from the input / output unit 300 that the sheet member P is embossed paper, the heating temperature t in the halogen heaters 102, 104, and 106 is fixed in the control unit 13 as shown in Table 1 above. The surface temperature of the belt 84 is controlled to be T2, for example, 170 to 200 ° C. Then, the control unit 13 sets the peripheral speed v of the heating roll 89 to V2 lower than V1, for example, 310 mm / s through the input / output unit 300, or operates at a low speed, or sets the peripheral speed v of the heating roll 89 to V1. The user is inquired about whether to drive at high speed.

  When the user selects the low speed operation, the control unit 13 sets the circumferential speed v of the heating roll 89 to V2. On the other hand, when the user selects high speed operation, the peripheral speed v of the heating roll 89 is set to V1.

  As shown in FIG. 1, a conveying device 108 that conveys the sheet member P sent from the fixing unit 82 to the downstream side is provided on the downstream side of the fixing unit 82, and the fixing unit is disposed on the downstream side of the conveying device 108. A cooling unit 110 for cooling the sheet member P heated by 82 is provided. The cooling unit 110 is provided with an absorption device 112 that absorbs the heat of the sheet member P on the upper side across the conveyance path 60, and a pressing device 114 that presses the conveyed sheet member P against the absorption device 112. It has been. Further, a decurling unit 140 that corrects the warp of the sheet member P is provided on the downstream side of the cooling unit 110.

  The absorbing device 112 is provided with an endless absorbing belt 116 that comes into contact with the sheet member P and absorbs the heat of the sheet member P, and includes a plurality of support rolls 118 that support the absorbing belt 116, and the absorbing belt 116. A driving roll 120 that transmits a driving force to the inner side of the absorbing belt 116 is provided. Further, a heat sink 122 formed of an aluminum material that dissipates heat absorbed by the absorption belt 116 by contacting the absorption belt 116 in a planar shape is provided inside the absorption belt 116.

  The pressing device 114 has an endless pressing belt 130 that contacts the sheet member P and presses the sheet member P against the absorbing device 112, and a plurality of support rolls on which the pressing belt 130 is stretched and supported rotatably. 132 is provided. With these configurations, the heat of the sheet member P is removed, and the sheet member P is cooled.

  A discharge roll 198 is provided downstream of the decurling unit 140 to discharge the sheet member P having an image formed on one side thereof to a discharge unit 196 attached to the side surface of the second processing unit 10B. Further, above the decal processing unit 140, as an example of temperature and humidity measuring means for measuring the internal temperature and humidity of the second processing unit 10B or the external temperature and humidity and outputting the temperature and humidity data to the control unit 13. Temperature / humidity sensor 119 is provided. Here, when images are formed on both surfaces of the sheet member P, the sheet member P is conveyed to the reversing unit 200 provided downstream of the decurling unit 140.

  The reversing unit 200 is provided with a reversing path 202. The reversing path 202 includes a branch path 202A that branches from the transport path 60, a sheet transport path 202B that transports the sheet member P transported along the branch path 202A toward the first processing unit 10A, and a sheet transport path. A reversing path 202C is provided, in which the sheet member P conveyed along 202B is folded back in the reverse direction to be conveyed in a switchback manner and the front and back are reversed. With this configuration, the sheet member P that has been switched back in the reverse path 202C is transported toward the first processing unit 10A, and further enters the transport path 60 provided above the paper feed cassette 48, whereby the transfer position T Will be sent again.

  Next, the operation of this embodiment will be described.

  First, the image forming process of the image forming apparatus 10 will be described.

  As shown in FIG. 1, when each unit of the image forming apparatus 10 is activated, the image data subjected to image processing by the control unit 13 is converted into color material gradation data of each color and sequentially supplied to the exposure unit 40. Is output. Each exposure unit 40 emits each exposure light L according to the color material gradation data of each color, performs scanning exposure on each photoconductor 18 charged by the scorotron charger 20 (see FIG. 2), and electrostatic latent An image is formed. Then, the electrostatic latent image formed on the photosensitive member 18 (see FIG. 2) is converted into a first special color (V), a second special color (W), yellow (Y), and magenta (M ), Cyan (C), and black (K) as toner images (developer images) of the respective colors, and are developed.

  Subsequently, the toner images of the respective colors formed on the photoreceptors 18 of the image forming units 16V, 16W, 16Y, 16M, 16C, and 16K are converted into six primary transfer rolls 36V, 36W, 36Y, 36M, 36C, and 36K. Are successively transferred onto the intermediate transfer belt 34 in a multiple manner. The color toner images transferred onto the intermediate transfer belt 34 are secondarily transferred onto the sheet member P conveyed from the paper feed cassette 48 by the secondary transfer roll 62. The sheet member P to which the toner image has been transferred is conveyed by the conveying device 70 toward the fixing unit 82 provided inside the second processing unit 10B.

  Subsequently, the toner images of the respective colors on the sheet member P are fixed on the sheet member P by being heated and pressed by the fixing unit 82. Further, the sheet member P on which the toner image is fixed is cooled by passing through the cooling unit 110, and then sent to the decurling unit 140, and the warp generated in the sheet member P is corrected. Then, the sheet member P whose warpage has been corrected is discharged to the discharge unit 196 by the discharge roll 198.

  On the other hand, when an image is formed on a non-image surface where no image is formed (in the case of duplex printing), the sheet member P is sent to the reversing unit 200 by a switching member (not shown). The sheet member P sent to the reversing unit 200 is reversed through the reversing path 202 and sent to the conveying path 60 provided above the paper feed cassette 48, and a toner image is formed on the back surface by the procedure described above. Is done.

  When the user does not input that the sheet member P is embossed paper, in the fixing unit 82, the peripheral speed v of the heating roll 89 is set to V1, and the halogen temperature is set so that the surface temperature of the transfer belt 84 becomes T1. The heating temperature t of the heaters 102, 104, and 106 is controlled.

  On the other hand, when the user inputs to the input / output unit 300 that the sheet member P is embossed paper, the controller 13 controls the halogen heaters 102, 104, and 106 so that the surface temperature of the transfer belt 84 becomes T2. In addition to controlling the heating temperature t, an inquiry is made as to whether to perform low speed operation or high speed operation.

  When the user designates the low speed operation in the input / output unit 300, the peripheral speed v of the heating roll 89 is set to V2 in the fixing unit 82 by the control command from the control unit 13, and the toner image formed on the sheet member P is fixed. Done. In the low speed operation, the fixing temperature of the sheet member P is T2 higher than the fixing temperature T1 for plain paper or coated paper, and the conveyance speed of the sheet member P is substantially equal to the peripheral speed v = V2 of the heating roll 89. Since the peripheral speed v of the heating roll 89 when the sheet member P is plain paper or coated paper is smaller than V1, the toner that has entered the concave portion of the embossed paper is reliably melted and fixed. Therefore, the toner does not fall off from the embossed paper after fixing, and a good quality toner image can be obtained. Therefore, low-speed operation can be rephrased as an image quality priority mode in which image quality is prioritized.

  On the other hand, when the user designates high speed operation, in the fixing unit 82, the fixing temperature t is controlled so that the surface temperature of the fixing belt 84 becomes T2 as in the low speed operation. The speed v is set to V1 as in the case where the sheet member P is plain paper or coated paper. Here, the fixing temperature T2 is selected so that the toner image is reliably fixed even when the circumferential speed v of the heating roll 89 is V1, so that the fixing property of the toner image on the embossed paper is maintained. The productivity, that is, the number of fixed sheets per unit time can be improved in the same manner as when the sheet member P is plain paper or coated paper. Therefore, the high-speed operation can be paraphrased as a productivity priority mode in which the productivity that is the number of fixings per unit time is prioritized.

  In the first embodiment, the user inputs to the input / output unit 300 that the sheet member P is embossed paper. However, the sheet member P is plain paper or coated paper on the conveyance path 60, or embossed. A sensor for optically or mechanically detecting whether the sheet is paper is provided. When the sensor detects that the sheet member P is embossed paper, the fixing temperature t is set so that the surface temperature of the fixing belt 84 becomes T2. In addition, the user may be inquired whether to select low speed operation or high speed operation.

  In the case of using a fixing unit in which the sheet member is passed between a pair of rolls and fixed, when the sheet member P is embossed paper, the toner that has entered the concave portion of the paper is sufficiently melted and fixed. Even if the peripheral speed v of the roll is lowered than when the sheet member P is plain paper or coated paper and the running speed of the sheet member P is lowered, the toner from the embossed paper after fixing is difficult. It was difficult to prevent omission of images.

  On the other hand, in the image forming apparatus 10 according to the first embodiment, as a fixing device, a fixing belt module 86 including a fixing belt 84, a heating roll 89, a support roll 90, a support roll 92, and an attitude correction roll 94; Since the fixing unit 82 is used which is pressed by the heating roll 89 in the fixing belt module 86 and is composed of the pressure roll 88 whose surface is the elastic layer 88B, the fixing belt 84 and the pressure roll 88 are The contact is made with a larger nip width, in other words, with a larger area than a fixing unit composed of a pair of rolls. Therefore, heat from the halogen heaters 102, 104, 106 provided on the heating roll 89, the support roll 90, and the support roll 92 is effectively transmitted to the toner image on the sheet member P via the fixing belt 84.

  Moreover, as described above, when the sheet member P is embossed paper, the heating temperature t of the halogen heaters 102, 104, and 106 is set so that the surface temperature of the fixing belt 84 is T2 higher than T1 in the case of plain paper. Be controlled.

  Therefore, even when the sheet member P is embossed paper, not only the toner on the convex surface of the embossed paper but also the toner that has entered the concave surface is surely melted and fixed, so that the toner may fall off from the embossed paper after fixing. Absent.

  Even when the circumferential speed v of the heating roll 89 is set to V1 which is the same as when the sheet member P is plain paper or coated paper, the fixing property of the toner image is maintained. Even when the sheet member P is embossed paper, the same productivity as that of plain paper or coated paper, in other words, the number of fixed sheets per unit time can be maintained.

  The example in which the fixing unit 82 is applied to an electrophotographic image forming apparatus has been described above, but the fixing unit 82 can also be applied to an ink jet image forming apparatus. Further, the peripheral speed v of the heating roll 89 during high-speed operation is not limited to V1 as long as it is faster than V2.

DESCRIPTION OF SYMBOLS 10 Image forming apparatus 16 Developing unit 32 Transfer unit 82 Fixing unit 84 Fixing belt 86 Fixing belt module 88 Pressure roll 89 Fixing belt drive roll 90, 92 Stretching roll 94 Posture correction roll 96 Peel pad 102 Halogen heater 104 Halogen heater 106 Halogen heater

Claims (3)

A fixing belt supported so as to be able to circulate;
Driving means for circulatingly driving the fixing belt;
A pressure roll pressed against the fixing belt and sandwiching a recording medium with the fixing belt;
Heating means for heating the transfer belt;
With
The fixing device in which the heating temperature in the heating unit is set higher when the recording medium is embossed paper than when the recording medium is plain paper or coated paper. When the recording medium is embossed paper, the recording medium feed speed is set lower than when the recording medium is plain paper or coated paper, and the recording medium is plain paper or coated paper. The fixing device according to claim 1, wherein the fixing device can be set to any one of high-speed operation in which the feeding speed of the recording medium is set to be the same as that of paper. An image forming unit for forming an image on a recording medium;
The fixing device according to claim 1 or 2, wherein the image forming unit fixes an image formed on the recording medium.
An image forming apparatus comprising:

Images