Fixing system and image forming apparatus

Abstract

This suppresses image quality degradation compared to when the processor only performs the fixing mode. [Solution] The fixing system comprises a rotating body, an endless fixing member that forms a clamping region that clamps a medium between itself and the rotating body, a heating member having a contact region that contacts the inner circumference of the fixing member via a lubricant in the clamping region and generates heat in the contact region, and a processor, wherein the processor performs a fixing mode in which the fixing member heated by the heating member clamps the medium between itself and the rotating body in the clamping region and rotates in the forward direction to fix an image on the medium, and a rotation mode in which the heating member generates heat on the upstream side of the contact region in the forward direction and does not generate heat on the downstream side and the fixing member rotates in the forward direction, and a rotation mode in which the heating member generates heat on the upstream side of the contact region in the reverse direction and does not generate heat on the downstream side and the fixing member rotates in the reverse direction.

Description

Technical Field

[0001] The present disclosure relates to a fixing system and an image forming apparatus.

Background Art

[0002] Patent Document 1 discloses an image heating apparatus having a rotatable flexible member, a radiant heat source, a support member, a pressure member, and a pressure applying means. The radiant heat source is disposed at a position spaced from the flexible member inside the flexible member. The support member supports the inner surface side of the flexible member and has a sliding surface coated with a lubricant on the inner surface side. The pressure member forms a nip portion with the support member via the flexible member. The pressure applying means applies a pressure between the pressure member and the support member. The image heating apparatus heats while passing a recording material through the nip portion. Further, the image heating apparatus has a pressure relaxation means and a lubricant displacement means. The pressure relaxation means relaxes the pressure applied by the pressure applying means. The lubricant displacement means displaces at least a part of the lubricant that has moved downstream due to paper passage together with the flexible member to a position upstream of the sliding surface during paper passage and not irradiated with direct light from the radiant heat source in a state where the pressure is relaxed by the pressure relaxation means.

[0003] Patent Document 2 discloses a heating apparatus having a film, a support member, and a pressure member. The support member has a sliding surface on which the film slides and supports the film. The pressure member forms a pressure contact nip portion by sandwiching the film therebetween and the sliding surface. The heating apparatus heats while sandwiching and conveying a material to be heated between the film and the pressure member in the pressure contact nip portion while slidingly moving the film on the sliding surface. Further, the heating apparatus interposes a lubricant containing a fluororesin powder having an average secondary aggregation particle size of 10 to 30 μm between the sliding surface and the film.

[0004] Patent Document 3 discloses an image heating device comprising a belt member, a drive member, a sliding member, and a means for heating the belt member. The belt member has a lubricant applied to its inner surface. The drive member contacts the outer surface of the belt member and rotates the belt member. The sliding member slides against the inner surface of the belt member, sandwiching the belt member between itself and the drive member. The image heating device further comprises a pressurizing mechanism and a control means. The pressurizing mechanism can change the pressure applied to the belt member by the drive member and the sliding member. The control means can execute a lubricant transfer mode in which the belt member is rotated by the drive member while the pressurizing force applied by the pressurizing mechanism is lower than that used during image heating. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2013-130793 [Patent Document 2] Japanese Patent Publication No. 2005-317519 [Patent Document 3] Japanese Patent Publication No. 2011-33654 [Overview of the project] [Problems that the invention aims to solve]

[0006] A possible fixing system includes a rotating body, an endless fixing member, a heating member, and a processor. The endless fixing member forms a clamping region that sandwiches the medium between itself and the rotating body. The heating member has a contact region that contacts the inner circumference of the fixing member via a lubricant within the clamping region, and generates heat in the contact region.

[0007] Furthermore, in the fixing system, there is a possibility that the processor may only perform a fixing mode in which the fixing member, heated by the heat-generating element, clamps the medium between the medium and the rotating body in the clamping region and rotates in the forward direction to fix the image on the medium. In this case, the lubricant between the heat-generating element and the fixing member decreases in the clamping region, which may result in an increase in rotational torque load and image quality defects such as gloss unevenness and fixing failure due to temperature unevenness.

[0008] This disclosure aims to suppress image quality defects compared to a case where the processor only performs a fixing mode in which the fixing member, heated by a heat-generating element, clamps the medium between the fixing element and the rotating element in the clamping region and rotates in the forward direction to fix the image on the medium. [Means for solving the problem]

[0009] The first embodiment comprises a rotating body, an endless fixing member that forms a clamping region that sandwiches a medium between the rotating body, a heating member having a contact region that contacts the inner circumference of the fixing member via a lubricant in the clamping region and generates heat in the contact region, and a processor, wherein the processor performs a fixing mode in which the fixing member heated by the heating member sandwiches the medium between the rotating body in the clamping region and rotates in the forward direction to fix an image on the medium, and a rotation mode in which the heating member generates heat on the upstream side of the contact region in the forward direction and does not generate heat on the downstream side and the fixing member rotates in the forward direction, and a reverse operation in which the heating member generates heat on the upstream side of the contact region in the reverse direction and does not generate heat on the downstream side and the fixing member rotates in the reverse direction.

[0010] In the second embodiment, in the first embodiment, the processor performs one of the forward rotation operation and the reverse rotation operation in the rotation mode, and then performs the other of the forward rotation operation and the reverse rotation operation.

[0011] In the third embodiment, in the second embodiment, the processor, in the rotation mode, performs the other action after a predetermined period of time has elapsed with the heating element stopped generating heat.

[0012] In the fourth embodiment, in the first embodiment, the processor starts rotating the fixing member after the heating member has generated heat in at least one of the rotation modes.

[0013] In the fifth embodiment, in the fourth embodiment, the processor rotates the fixing member while the heating member is heated after the heating member has heated up in at least one of the rotation modes.

[0014] In the sixth embodiment, in the first embodiment, the processor rotates the fixing member while the rotating body is pressed against the fixing member in the clamping region in at least one of the rotation modes.

[0015] In the seventh embodiment, in the sixth embodiment, the processor rotates the fixing member after the heating member has heated up, while the rotating body is pressed against the fixing member in the clamping region in at least one of the rotation modes.

[0016] The eighth embodiment comprises an image forming unit that forms an image on a medium, and a fixing system according to any one of the first to seventh embodiments for fixing the image formed on the medium. [Effects of the Invention]

[0017] According to the configuration of the first embodiment, compared to the case in which the processor only performs a fixing mode in which a fixing member heated by a heat-generating member clamps the medium between the rotating body in the clamping region and rotates in the forward direction to fix the image on the medium, image quality defects are suppressed.

[0018] According to the configuration of the second aspect, image quality degradation is suppressed when the processor performs only one of the forward rotation operation and the reverse rotation operation in the rotation mode, compared to when it performs both.

[0019] According to the configuration of the third aspect, image quality degradation is suppressed when the processor continuously performs the other operation after performing one operation in the rotation mode, compared to when it performs both.

[0020] According to the configuration of the fourth aspect, image quality degradation is suppressed when the heat generating member generates heat after the rotation of the fixing member is started in at least one of the operations performed by the processor in the rotation mode, compared to when the heat generating member generates heat before the rotation of the fixing member is started.

[0021] According to the configuration of the fifth aspect, image quality degradation is suppressed when the processor rotates the fixing member in a state where the heat generation of the heat generating member has stopped in at least one of the operations performed by the processor in the rotation mode, compared to when the heat generating member generates heat while the fixing member is rotating.

[0022] According to the configuration of the sixth aspect, image quality degradation is suppressed when the processor rotates the fixing member without pressing the rotating body against the fixing member in at least one of the operations performed by the processor in the rotation mode, compared to when the rotating body is pressed against the fixing member.

[0023] According to the configuration of the seventh aspect, image quality degradation is suppressed when the rotating body is pressed against the fixing member in the sandwiching region after the heat generating member has generated heat in at least one of the operations performed by the processor in the rotation mode, compared to when the rotating body is pressed against the fixing member before the heat generating member has generated heat.

[0024] According to the configuration of the eighth aspect, image quality degradation is suppressed when the processor executes only the fixing mode in which the fixing member heated by the heat generating member sandwiches the medium between the rotating body and rotates in the forward rotation direction to fix the image of the medium, compared to when the processor executes both the rotation mode and the fixing mode.

Brief Description of the Drawings

[0025] [Figure 1] It is a schematic diagram showing an image forming apparatus according to the present embodiment. [Figure 2] It is a block diagram showing the hardware configuration of the controller according to the present embodiment. [Figure 3] This is a cross-sectional view showing the separated state in which the pressure roll is separated from the fixing belt in the fixing system according to this embodiment. [Figure 4] This is a cross-sectional view showing the pressurized state in which the pressure roll is pressed against the fixing belt in the fixing system according to this embodiment. [Figure 5] This is a schematic diagram showing the configuration of the heater according to this embodiment. [Figure 6] This flowchart shows the modes that the controller according to this embodiment can execute. [Figure 7] This is a flowchart showing the case when the controller according to this embodiment executes the grease unevenness improvement mode. [Modes for carrying out the invention]

[0026] An example of an embodiment relating to this disclosure will be described below with reference to the drawings.

[0027] In each figure, arrow H indicates the vertical direction of the image forming apparatus, arrow W indicates the width direction of the image forming apparatus, and arrow D indicates the depth direction of the image forming apparatus. These vertical, width, and depth directions intersect each other (specifically, are orthogonal directions). The +S and +R directions represent counterclockwise rotation with the depth direction as the axis. The -S and -R directions represent clockwise rotation with the depth direction as the axis. These directions are defined for the sake of explanation and do not mean that the configuration of the image forming apparatus is limited to these directions. In some cases, the term "image forming apparatus" is omitted in each direction of the image forming apparatus. The symbol with a "·" inside a "○" in the figures represents an arrow pointing from the back of the page to the front.

[0028] In this disclosure, numerical ranges indicated using "~" include the numbers before and after "~" as the minimum and maximum values, respectively. In numerical ranges described in stages within this disclosure, the upper or lower limit of one numerical range may be replaced by the upper or lower limit of another numerical range described in stages.

[0029] <Image forming apparatus 10> The image forming apparatus 10 forms an image on a sheet material P, such as paper. The sheet material P is an example of a medium in this disclosure. In the image forming apparatus 10, as shown in Figure 1, the various parts are arranged inside the apparatus body 10a. The image forming apparatus 10 includes a storage unit 12, a main operation unit 14, a transport unit 18, and a controller 70. The image forming apparatus 10 further includes a display unit 40 as an interface for the user to exchange information with the image forming apparatus 10.

[0030] <Storage section 12> The storage section 12 houses the sheet members P. The storage section 12 has a first storage section 22, a second storage section 24, a third storage section 26, and a fourth storage section 28. For example, sheet members P of different sizes are appropriately stored in the first storage section 22, the second storage section 24, the third storage section 26, and the fourth storage section 28. The first storage section 22, the second storage section 24, the third storage section 26, and the fourth storage section 28 are also equipped with a feed roll 32 and a double-feed prevention roll 34, respectively. The feed roll 32 feeds out the stored sheet members P one by one based on instructions from the controller 70. The double-feed prevention roll 34 transports the sheet members P fed out by the feed roll 32 one by one to the transport path 30 in the image forming apparatus 10.

[0031] Although the storage unit 12 had multiple storage units, the storage unit of this disclosure is not limited to this. The storage unit of this disclosure may consist of a single storage unit. Furthermore, when the storage unit of this disclosure has multiple storage units, the number is not limited to four.

[0032] <Main operating section 14> The main operating unit 14 outputs image data sent from a user terminal (not shown) or a document reading unit 16 to a sheet member P transported from a storage unit 12. The main operating unit 14 includes an image forming unit 60 and a fixing device 100. The image forming unit 60 is an example of an image forming unit in this disclosure.

[0033] The image forming unit 60 forms a toner image. The toner image is an example of an image in this disclosure. The image forming unit 60 has image forming units 64Y, 64M, 64C, and 64K that form toner images of yellow (Y), magenta (M), cyan (C), and black (K). In the following description, unless otherwise specified, the Y, M, C, or K at the end of the reference numerals may be omitted.

[0034] The image forming unit 64 comprises a photoreceptor drum 62, a charger 42, a developer 44, a cleaning member 46, and an exposure device 66 (66Y, 66M, 66C, and 66K). The charger 42 charges the rotating photoreceptor drum 62, and the exposure device 66 irradiates the charged photoreceptor drum 62 with exposure light to form an electrostatic latent image. Furthermore, the developer 44 develops the electrostatic latent image and visualizes it as a toner image. In other words, the image forming apparatus 10 of this embodiment is an electrophotographic apparatus.

[0035] The image forming unit 60 further includes a transfer unit 68. The transfer unit 68 transfers the toner image to the sheet member P. The transfer unit 68 is positioned below the image forming units 64Y, 64M, 64C, and 64K. The transfer unit 68 comprises a transfer belt 48, a primary transfer roll 50, a secondary transfer roll 52, an auxiliary roll 54, and a roll 56.

[0036] The transfer belt 48 is formed in an endless manner and has a triangular shape with its vertex pointing downwards when viewed from the front side in the depth direction.

[0037] The primary transfer rolls 50 (50K, 50C, 50M, and 50Y) are positioned in conjunction with the photoconductor drum 62, and sandwich the transfer belt 48 between them, transferring the toner image from the photoconductor drum 62 to the transfer belt 48.

[0038] The secondary transfer roll 52 is positioned below the primary transfer roll 50 and transfers the toner image on the transfer belt 48 to the sheet material P at the transfer position T.

[0039] The auxiliary roll 54 is positioned inside the transfer belt 48 and on the opposite side of the secondary transfer roll 52, with the transfer belt 48 in between.

[0040] Multiple rolls 56 are arranged inside the transfer belt 48, and the transfer belt 48 is wrapped around them. At least one of the rolls 56 functions as a drive roll that causes the transfer belt 48 to rotate in the direction of arrow C in the figure.

[0041] The fixing device 100 is positioned downstream of the transfer position T and fixes the toner image transferred onto the sheet member P to the sheet member P. Details of the fixing device 100 will be described later.

[0042] <Conveying section 18> The conveying unit 18 receives sheet members P that are conveyed from the double-feed prevention roll 34 or inserted from outside the main body of the device 10a and conveys them one by one. The conveying unit 18 has a conveying path 30, a conveying roll 36, and a conveying device 38.

[0043] The transport path 30 is the path that determines the transport direction of the sheet member P (hereinafter simply referred to as "transport direction CV").

[0044] The upstream portion of the transport path 30 extends from bottom to top on one side in the width direction. A manual feed path 33 is connected to the upper end of the upstream portion of the transport path 30.

[0045] The downstream portion of the transport path 30 extends from one side in the width direction to the other, and is connected to a discharge section 80 that discharges the sheet member P to the outside of the device body 10a. A double-sided transport path 31 is connected to the downstream end of the transport path 30, where the sheet member P is transported and inverted in order to form an image on the back surface of the sheet member P. The double-sided transport path 31 is equipped with a switchback path 31a, and the sheet member P sent out from the switchback path 31a is inverted front and back and sent to the upper end of the upstream portion of the transport path 30 in the transport direction CV.

[0046] Multiple conveyor rolls 36 are arranged along the conveyor path 30. The conveyor rolls 36 are arranged in pairs on the main body 10a of the device so as to sandwich the conveyor path 30.

[0047] The transport device 38 is positioned upstream of the transfer position T in the transport direction CV, and temporarily stops the sheet member P, then sends the sheet member P to the secondary transfer position at a predetermined timing.

[0048] <Controller 70> The controller 70 is a computer that controls each part of the image forming apparatus 10. As shown in Figure 2, the controller 70 has the following components: CPU (Central Processing Unit) 72A, ROM (Read Only Memory) 72B, RAM (Random Access Memory) 72C, storage 72D, input / output unit 74, and network interface (network I / F) 76. Each component is connected to the others so as to be able to communicate with each other via bus 72E.

[0049] The CPU 72A is a central processing unit that executes various programs and controls various components. Specifically, the CPU 72A reads a program from the ROM 72B or storage 72D and executes the program using the RAM 72C as a working area. The CPU 72A is an example of the processor of this disclosure. The CPU 72A controls each of the above components and performs various calculations according to the program recorded in the ROM 72B or storage.

[0050] ROM72B stores various programs and data. RAM72C temporarily stores programs or data as a working area. Storage72D consists of storage devices such as HDD (Hard Disk Drive) and SSD (Solid State Drive) and stores various programs, including the operating system, and various data.

[0051] The input / output unit 74 receives signals between the various components of the image forming apparatus 10 in order to enable the image forming apparatus 10 to perform its functions. For example, the input / output unit 74 receives signals between the storage unit 12, the main operating unit 14, and the transport unit 18.

[0052] Network I / F76 is an interface for communicating with other devices, and standards such as Ethernet®, FDDI, and Wi-Fi® are used.

[0053] <Details of the fixing device 100> The fixing device 100 is a device that fixes a toner image onto a sheet member P. As shown in Figures 3 and 4, the fixing device 100 includes a pressure roll 120 and a heating unit 140.

[0054] In the fixing device 100, the toner image is fixed to the sheet member P using the pressure roll 120 and the heating unit 140. Specifically, in the fixing device 100, the toner image transferred to the sheet member P in the image forming unit 60 is fixed to the sheet member P by heating and pressurizing the sheet member P that has been transported from the transfer position T.

[0055] The fuser device 100, together with the controller 70, constitutes the fuser system 90. Alternatively, the fuser system 90 may be understood as consisting of the fuser device 100 and the CPU 72A in the controller 70.

[0056] <Pressure Roll 120> The pressure roll 120 is a roll-shaped member oriented in the depth direction, as shown in Figures 3 and 4. The pressure roll 120 is positioned below the conveying path 30. The pressure roll 120 is rotatably supported with respect to the device body 10a and is rotationally driven in the +S and -S directions by a drive unit (not shown). The pressure roll 120 is an example of a rotating body of this disclosure. The pressure roll 120 is also capable of moving toward and away from the fixing belt 142 by a separation mechanism (not shown). As a result, the pressure roll 120 can change between a separated state shown in Figure 3, where it is separated from the fixing belt 142, and a pressed state shown in Figure 4, where it is pressed toward the fixing belt 142.

[0057] The pressure roll 120 has a multilayer structure comprising, for example, a core metal 124, an elastic layer 122, and a release layer 126. The core metal 124 is a thin-walled cylindrical shape made of steel and is supported by the main body 10a of the apparatus. The elastic layer 122 is a layer containing silicone rubber or the like that is coated on the surface of the core metal 124. The release layer 126 is a surface layer that is coated on the surface of the elastic layer 122.

[0058] <Heating section 140> The heating unit 140 is a structure that follows the depth direction, as shown in Figures 3 and 4. The heating unit 140 is positioned above the transport path 30. The heating unit 140 is configured to melt the toner on the sheet member P. The heating unit 140 comprises a fixing belt 142, a heater 144, a pad 146, and a support member 148. The fixing belt 142 is an example of a fixing member of this disclosure. The heater 144 is an example of a heat-generating member of this disclosure.

[0059] The fixing belt 142 is an endless belt with the depth direction as its axial direction. The fixing belt 142 has a thin-walled cylindrical base material made of a synthetic resin such as polyimide resin or polyamide-imide resin, and a release layer containing fluororesin is provided on its outer surface as needed. The fixing belt 142 is rotatably supported with respect to the main body 10a of the apparatus.

[0060] The fixing belt 142 has a fixing nip N. The fixing nip N is formed when the pressure roll 120 is pressed against the fixing belt 142, resulting in the pressurized state shown in Figure 4. The fixing nip N is the region in which the fixing belt 142 sandwiches the sheet member P between itself and the pressure roll 120. The fixing nip N is an example of the sandwiching region of this disclosure.

[0061] The fixing belt 142 can rotate in the -R and +R directions in conjunction with the rotation of the pressure roll 120 while in contact with the pressure roll 120. In this embodiment, the fixing belt 142 rotates in the +R direction in conjunction with the rotation of the pressure roll 120 in the -S direction while under pressure from the pressure roll 120. Also, the fixing belt 142 rotates in the -R direction in conjunction with the rotation of the pressure roll 120 in the +S direction while under pressure from the pressure roll 120.

[0062] The heater 144 is a heat-generating device. Specifically, the heater 144 is a planar heating element positioned along the depth direction and inside the fixing belt 142. The heater 144 has a contact area 144S that contacts the inner circumference of the fixing belt 142 via grease G at the fixing nip N. The first dimension of the contact area 144S in the +R direction is, for example, larger than the second dimension of the fixing nip N in the +R direction. Note that the first and second dimensions may be the same.

[0063] The heater 144 is capable of partially generating heat in the +R direction within the contact area 144S. In this embodiment, the heater 144 has a first heating element 144A, a second heating element 144B, and a third heating element 144C, as shown in Figure 5.

[0064] The first heating element 144A, the second heating element 144B, and the third heating element 144C are formed in an elongated shape along the depth direction. The first heating element 144A, the second heating element 144B, and the third heating element 144C are arranged in this order, spaced apart in the +R direction. The first heating element 144A generates heat on the upstream side in the +R direction of the contact area 144S. The third heating element 144C generates heat on the downstream side in the +R direction of the contact area 144S (in other words, the upstream side in the -R direction). The third heating element 144C generates heat between the first heating element 144A and the second heating element 144B in the contact area 144S (specifically, in the central part in the +R direction).

[0065] The first heating element 144A, the second heating element 144B, and the third heating element 144C are formed, for example, by a wiring pattern and generate heat when energized. As shown in Figure 5, the first heating element 144A is narrower at both ends in the depth direction than at the center. The second heating element 144B and the third heating element 144C are wider at both ends in the depth direction than at the center.

[0066] In the heater 144, based on instructions from the controller 70, all or part of the first heating element 144A, the second heating element 144B, and the third heating element 144C can be selectively heated. The heater 144 heats the fixing belt 142 via the grease G by heating all or part of the first heating element 144A, the second heating element 144B, and the third heating element 144C.

[0067] Here, grease G is a lubricant that reduces the sliding resistance between the fixing belt 142 and the heater 144 when sandwiched between them. Grease G has a lower consistency than fluorine grease. For example, the mixed consistency of grease G is 250 or less as specified in JIS K 2220. Furthermore, the viscosity of grease G at 200°C measured with a rheometer is 50 to 1500 Pa·s, preferably 80 to 1000 Pa·s, and more preferably 100 to 500 Pa·s. The weight loss rate of grease G when heated and stored at 230°C for 336 hours is 0 to 20 wt%, preferably 0 to 15 wt%, and more preferably 0 to 10 wt%.

[0068] Grease G is composed of a base oil combined with a thickener. The base oil of Grease G is a silicone oil, preferably dimethyl silicone oil, methylphenyl silicone oil, or diphenyl silicone oil, and may have partially introduced side chains. The weight-average molecular weight Mw of the silicone oil is 10,000 to 100,000, preferably 10,000 to 60,000, and more preferably 15,000 to 40,000.

[0069] Furthermore, in Grease G, one or more inorganic materials such as melamine cyanurate, boron nitride, carbon black, silica, graphite, molybdenum disulfide, zinc stearate, and tungsten disulfide are selected as components of the thickener. The average particle size (D50v) of the thickener is 0.01 to 15 μm, preferably 0.1 to 10 μm, and more preferably 0.1 to 5 μm. The weight ratio of base oil in the components of Grease G is 40 to 95 wt%, preferably 50 to 85 wt%, and more preferably 50 to 75 wt%.

[0070] The viscosity of grease G is measured by the following method: The grease sample is placed between parallel plates with a diameter of 40 mm, and the viscosity is measured using a dynamic viscoelasticity measuring device (rheometer ARES-G2, manufactured by T.A. Instruments Inc.) with a gap of 1 mm and an angular velocity of 0.1 rad / s, while the temperature is raised from 40°C to 200°C at a rate of 6°C / min.

[0071] The weight loss rate of grease G is calculated by taking a 5g sample of grease in an aluminum cup and heating it in an oven at 230°C for 336 hours, then comparing the weight before and after heating.

[0072] The average particle size of the thickener is measured by the following method: A 2g sample of grease is placed on filter paper, and 30g of THF (tetrahydrofuran) is added and filtered by suction to separate the base oil and the thickener. The separated thickener is dispersed in water, and the particle size distribution is measured using a particle size analyzer (LS13320, Beckman Coulter).

[0073] The pad 146 is a block-shaped member positioned along the depth direction and inside the fixing belt 142. The pad 146 supports the heater 144 from the outside, covering it from the inside of the fixing belt 142. In other words, the pad 146 supports the heater 144 at the upstream side of the downstream end 146A and the downstream side of the upstream end 146B in the +R direction (in other words, the conveying direction CV). The pad 146 is positioned such that the downstream end 146A and the upstream end 146B are in contact with the inner circumferential surface of the fixing belt 142 when the pressure roll 120 is pressurized against the fixing belt 142. The pad 146 is supported by the main body 10a of the device. The pad 146 directs the outer circumferential surface of the fixing belt 142 toward the outer circumferential surface of the pressure roll 120. The pad 146 further has a recess 146C. The recess 146C is a recessed portion formed on the surface opposite to the support surface of the heater 144.

[0074] The support member 148 is positioned along the depth direction and inside the fixing belt 142, and has a frame shape that is an inverted U when viewed from the depth direction. The support member 148 is supported by the main body 10a of the device. The support member 148 supports the pad 146 via the recess 146C. The support member 148 receives the pressing force of the pressure roll 120 via the heater 144 and the pad 146 when the fixing belt 142 is pressed against the pressure roll 120.

[0075] <Mode> The controller 70 performs a fixing mode and a grease unevenness improvement mode in the fixing device 100. The grease unevenness improvement mode is an example of a rotation mode in this disclosure.

[0076] <Fusing Mode> The fixing mode is a mode in which the toner image is fixed to the sheet material P. The fixing mode is performed when the image forming apparatus 10 forms an image.

[0077] In fixing mode, the fixing belt 142, heated by the heater 144, rotates the sheet member P in the +R direction by sandwiching it between the fixing nip N and the pressure roll 120, thereby fixing the image on the sheet member P.

[0078] In this embodiment, the fixing mode is specifically performed as follows: The fixing nip N is formed by pressurizing the pressure roll 120 as shown in Figure 4. The heater 144 selectively heats all or part of the first heating element 144A, the second heating element 144B, and the third heating element 144C. Which of the first heating element 144A, the second heating element 144B, and the third heating element 144C is heated is determined by conditions such as the width of the sheet member P. Then, the pressure roll 120 is rotated in the -S direction. As a result, the fixing belt 142 rotates in the +R direction, sandwiching the sheet member P between the pressure roll 120 and the fixing nip N, thereby fixing the image on the sheet member P. Note that the +R direction is an example of a forward rotation direction.

[0079] <Grease unevenness improvement mode> The grease unevenness improvement mode is a mode that improves the unevenness of grease G in the contact area 144S.

[0080] The grease unevenness improvement mode performs forward and reverse rotation. In forward rotation, the heater 144 generates heat on the upstream side in the +R direction of the contact area 144S, but does not generate heat on the downstream side, and the fixing belt 142 rotates in the +R direction. In reverse rotation, the heater 144 generates heat on the upstream side in the -R direction of the contact area 144S, but does not generate heat on the downstream side, and the fixing belt 142 rotates in the -R direction. Note that the -R direction is an example of the reverse direction.

[0081] In forward and reverse rotation, the heater 144 heats up before the fixing belt 142 begins to rotate. Specifically, the fixing belt 142 rotates with the pressure roll 120 pressurized against it by the fixing nip N, after the heater 144 has heated up.

[0082] In this embodiment, the grease unevenness improvement mode performs a reverse rotation operation after the forward rotation operation. Specifically, the grease unevenness improvement mode performs a reverse rotation operation after a predetermined period of time has elapsed with the heater 144's heat generation stopped. The specific operation of each part in the grease unevenness improvement mode will be described later.

[0083] <Flowchart> <Mode Determination> The mode switching in the controller 70 will be explained with reference to Figure 6. In step S10, the CPU 72A of the controller 70 determines whether or not the fixing mode can be maintained.

[0084] For example, in the following cases (i) to (iii), the CPU72A will not maintain the fixing mode and will enter the grease unevenness improvement mode. (i) When the image forming apparatus 10 has formed a predetermined number of images (ii) When a predetermined time has elapsed after image formation by the image forming apparatus 10 (iii) When the user (not shown) of the image forming apparatus 10 gives instructions

[0085] If the judgment result is "Y" indicating a positive result, CPU72A proceeds to step S20. In step S20, CPU72A executes the fixing mode. Then, CPU72A terminates the flow.

[0086] On the other hand, if the judgment result is "N" indicating negation, the CPU 72A proceeds to step S30. In step S30, the CPU 72A executes the grease unevenness improvement mode. The grease unevenness improvement mode is executed during periods when the fixing mode is not being executed, specifically during periods when image forming is not being performed in the image forming apparatus 10. For example, the grease unevenness improvement mode is executed after the fixing mode has finished, specifically after the image forming in the image forming apparatus 10 has finished. Then, the CPU 72A returns the flow to the beginning. Thus, the mode is switched.

[0087] The grease unevenness improvement mode may also be executed when the image forming apparatus 10 is powered on and started up.

[0088] <Executing the grease unevenness improvement mode> Next, the execution of the grease unevenness improvement mode in the controller 70 will be explained with reference to Figure 7.

[0089] When the CPU 72A of the controller 70 starts executing the grease unevenness improvement mode, in step S32 it operates the contact / disconnection mechanism to pressurize the pressure roll 120 to the state shown in Figure 4. As a result, the pressure roll 120 is pressed against the fixing belt 142, and a fixing nip N is formed. Then the CPU 72A proceeds to step S34.

[0090] In step S34, CPU 72A generates heat at the first heating element 144A of heater 144, while the second heating element 144B and the third heating element 144C of heater 144 remain unheated. As a result, the grease G softens on the upstream side in the +R direction of the fixing nip N. On the downstream side in the +R direction of the fixing nip N, the grease G does not soften easily. Then, CPU 72A proceeds to step S36.

[0091] In step S36, the CPU 72A rotates the pressure roll 120 in the -S direction relative to the drive unit. This causes the fixing belt 142 to rotate in the +R direction. In step S36, the CPU 72A starts rotating the pressure roll 120 after a predetermined reference time has elapsed since the heater 144 has heated up. Alternatively, in step S36, the CPU 72A may start rotating the pressure roll 120 after the temperature of the grease G on the +R upstream side of the fixing nip N or the surrounding components (e.g., the fixing belt 142, heater 144, and pad 146) has reached a predetermined reference temperature. Thus, in step S36, the fixing belt 142 is rotated in the +R direction while the grease G is softened. This causes the softened grease G to spread between the contact area 144S and the fixing belt 142 at the fixing nip N. Furthermore, on the downstream side of the fixing nip N in the +R direction, the grease G is less likely to soften, and therefore less likely to flow out from between the contact area 144S and the fixing belt 142. Then, the CPU 72A proceeds to step S38.

[0092] In step S38, CPU 72A determines whether the rotation time of the pressure roll 120 has exceeded a predetermined reference time. If the determination result is "Y", CPU 72A proceeds to step S40.

[0093] On the other hand, if the judgment result is "N", the CPU 72A proceeds to step S36. The CPU 72A then continues to rotate the pressure roll 120 in the -S direction until the rotation time of the pressure roll 120 has elapsed according to a predetermined reference time.

[0094] In step S40, CPU 72A stops the heating of heater 144 and stops the rotation of pressure roll 120. The timing of stopping the heating of heater 144 and stopping the rotation of pressure roll 120 may be simultaneous or staggered. Then, CPU 72A proceeds to step S42.

[0095] In step S42, CPU 72A operates the separation mechanism to move the pressure roll 120 to the separated state shown in Figure 3. This separates the pressure roll 120 from the fixing belt 142. Then, CPU 72A proceeds to step S44.

[0096] In step S44, CPU 72A determines whether a predetermined reference time has elapsed since the pressure roll 120 was separated. If the determination result is "Y", CPU 72A proceeds to step S46.

[0097] On the other hand, if the judgment result is "N", the CPU 72A proceeds to step S42. The CPU 72A then maintains the pressure roll 120 in a separated state until a predetermined reference time has elapsed since separating the pressure roll 120. If the process proceeds to step S42 while the pressure roll 120 is separated, step S42 functions as a process to maintain the separated state of the pressure roll 120. As described above, in the grease unevenness improvement mode, step S44 causes the heater 144 to stop generating heat and allows a predetermined period of time to elapse. This cools the heater 144, making it difficult for the grease G to soften on the downstream side in the +R direction at the fixing nip N.

[0098] In step S46, CPU 72A operates the contact / disconnection mechanism to pressurize the pressure roll 120 to the state shown in Figure 4. This pressurizes the pressure roll 120 against the fixing belt 142, forming a fixing nip N. Then, CPU 72A proceeds to step S48.

[0099] In step S48, CPU 72A generates heat at the third heating element 144C of heater 144, while the first heating element 144A and the second heating element 144B of heater 144 remain unheated. This causes the grease G to soften on the upstream side in the -R direction of the fixing nip N. On the downstream side in the -R direction of the fixing nip N, the grease G does not soften easily. Then, CPU 72A proceeds to step S50.

[0100] In step S50, the CPU 72A rotates the pressure roll 120 in the +S direction relative to the drive unit. This causes the fixing belt 142 to rotate in the -R direction. In step S50, the CPU 72A starts rotating the pressure roll 120 after a predetermined reference time has elapsed since the heater 144 has heated up. Alternatively, in step S50, the CPU 72A may start rotating the pressure roll 120 after the temperature of the grease G on the -R upstream side of the fixing nip N or the surrounding components (e.g., the fixing belt 142, heater 144, and pad 146) has reached a predetermined reference temperature. Thus, in step S50, the fixing belt 142 is rotated in the -R direction while the grease G is softened. This causes the softened grease G to spread between the contact area 144S and the fixing belt 142 at the fixing nip N. Furthermore, on the downstream side of the fixing nip N in the -R direction, the grease G is less likely to soften, and therefore the grease G is less likely to flow out from between the contact area 144S and the fixing belt 142. Then, the CPU 72A proceeds to step S52.

[0101] In step S52, CPU 72A determines whether the rotation time of the pressure roll 120 has exceeded a predetermined reference time. If the determination result is "Y", CPU 72A proceeds to step S54.

[0102] On the other hand, if the judgment result is "N", the CPU 72A proceeds to step S50. The CPU 72A then continues to rotate the pressure roll 120 in the +S direction until the rotation time of the pressure roll 120 has elapsed according to a predetermined reference time.

[0103] In step S54, CPU 72A stops the heating of heater 144 and stops the rotation of pressure roll 120. The timing of stopping the heating of heater 144 and stopping the rotation of pressure roll 120 may be simultaneous or staggered. Then, CPU 72A proceeds to step S56.

[0104] In step S56, CPU 72A operates the separation mechanism to move the pressure roll 120 to the separated state shown in Figure 3. This separates the pressure roll 120 from the fixing belt 142, and the process ends. The grease unevenness improvement mode is executed in this manner. Note that the operations from steps S32 to S40 correspond to forward rotation, and the operations from steps S46 to S54 correspond to reverse rotation.

[0105] <effect> Next, the operation of this embodiment will be explained.

[0106] In this embodiment, as described above, the CPU 72A performs a grease unevenness improvement mode in addition to the fixing mode. Therefore, image quality defects are suppressed compared to a configuration in which the CPU 72A performs only the fixing mode.

[0107] In this embodiment, the CPU 72A performs a forward rotation operation followed by a reverse rotation operation in the grease unevenness improvement mode. Therefore, image quality defects are suppressed compared to when the CPU 72A performs only one of the forward or reverse rotation operations in the grease unevenness improvement mode.

[0108] In this embodiment, in the grease unevenness improvement mode, the CPU 72A performs forward rotation, and then, after a predetermined period of time has elapsed with the heater 144's heat generation stopped, it performs reverse rotation. Therefore, compared to the case where the CPU 72A performs reverse rotation immediately after forward rotation in the grease unevenness improvement mode, image quality defects are suppressed.

[0109] In this embodiment, the CPU 72A starts rotating the fixing belt 142 after the heater 144 has heated up during forward and reverse rotation. This suppresses image quality defects compared to the case where the heater 144 heats up after the CPU 72A starts rotating the fixing belt 142 during forward and reverse rotation.

[0110] Specifically, in this embodiment, during forward and reverse rotation, the CPU 72A rotates the fixing belt 142 while the heater 144 is still heated after it has heated up. This suppresses image quality defects compared to the case where the CPU 72A rotates the fixing belt 142 after the heater 144 has stopped heating up during forward and reverse rotation.

[0111] More specifically, in this embodiment, the CPU 72A rotates the fixing belt 142 with the pressure roll 120 pressurized against the fixing belt 142 by the fixing nip N during forward and reverse rotation. Compared to the case where the CPU 72A rotates the fixing belt 142 without the pressure roll 120 pressurizing the fixing belt 142 during forward and reverse rotation, image quality defects are suppressed.

[0112] More specifically, in this embodiment, during forward and reverse rotation, the CPU 72A rotates the fixing belt 142 after the heater 144 has heated up, while the pressure roll 120 is pressurized against the fixing belt 142 by the fixing nip N. This suppresses image quality defects compared to the case where the pressure roll 120 is pressurized against the fixing belt 142 by the fixing nip N after the heater 144 has heated up during forward and reverse rotation.

[0113] In the image forming apparatus 10, as described above, image quality defects are suppressed, and therefore image defects in the image formed on the sheet member P are suppressed.

[0114] <Variations of the grease unevenness improvement mode> In this embodiment, the CPU 72A performed forward rotation (steps S32 to S40) and reverse rotation (steps S46 to S54) in the grease unevenness improvement mode, but is not limited to this. The CPU 72A may perform only one of forward rotation or reverse rotation in the grease unevenness improvement mode. Therefore, the CPU 72A only needs to perform at least one of forward rotation or reverse rotation in the grease unevenness improvement mode.

[0115] Furthermore, in this embodiment, the CPU 72A performed a forward rotation operation followed by a reverse rotation operation in the grease unevenness improvement mode, but this is not limited to this. The CPU 72A may also perform a reverse rotation operation followed by a forward rotation operation in the grease unevenness improvement mode.

[0116] Furthermore, in this embodiment, in the grease unevenness improvement mode, the CPU 72A performed forward rotation and then separated the pressure roll 120 from the fixing belt 142 (step S42). However, the pressure roll 120 may be kept in a pressurized state. In this case, steps S42 and S46 are omitted.

[0117] Furthermore, in this embodiment, the CPU 72A performs a forward rotation operation in the grease unevenness improvement mode, and then performs a reverse rotation operation after a predetermined period of time has elapsed with the heater 144's heat generation stopped. However, this is not limited to this. For example, the CPU 72A may perform a reverse rotation operation immediately after performing a forward rotation operation in the grease unevenness improvement mode.

[0118] Furthermore, in this embodiment, the CPU 72A starts rotating the fixing belt 142 after the heater 144 has heated up during forward and reverse rotation, but this is not limited to this. For example, the CPU 72A may heat up the heater 144 after starting to rotate the fixing belt 142 during forward and reverse rotation.

[0119] Specifically, in this embodiment, the CPU 72A rotated the fixing belt 142 while the heater 144 was still heated after it had heated up during forward and reverse rotation, but this is not limited to this. For example, the CPU 72A may rotate the fixing belt 142 while the heater 144 has stopped heating up during forward and reverse rotation.

[0120] More specifically, in this embodiment, the CPU 72A rotates the fixing belt 142 with the pressure roll 120 pressurized by the fixing nip N during forward and reverse rotation, but is not limited to this. For example, the CPU 72A may rotate the fixing belt 142 without the pressure roll 120 pressurizing the fixing belt 142 during forward and reverse rotation.

[0121] More specifically, in this embodiment, the CPU 72A rotates the fixing belt 142 after the heater 144 has heated up, while the pressure roll 120 is pressurized against the fixing belt 142 by the fixing nip N during forward and reverse rotation, but it is not limited to this. For example, the CPU 72A may pressurize the pressure roll 120 against the fixing belt 142 by the fixing nip N after the heater 144 has heated up during forward and reverse rotation.

[0122] <Other variations> Although this disclosure has described in detail certain embodiments, it will be apparent to those skilled in the art that this disclosure is not limited to such embodiments and can take various other embodiments within the scope of this disclosure.

[0123] In the above embodiment, an image forming apparatus 10 having the apparatus layout shown in Figure 1 was used for the explanation, but it is not limited thereto. For example, this disclosure is also applicable to image forming apparatuses having a different apparatus layout from that of the image forming apparatus 10. Furthermore, in the above embodiment, the main operating unit 14 was described using a tandem color type, but it is not limited thereto. The main operating unit may be rotary or monochrome. Also, the main operating unit is not limited to an indirect transfer method, but may be a direct transfer method.

[0124] In the above embodiment, the fixing belt 142 is configured to follow the rotation of the pressure roll 120 in the -R direction and +R direction while the pressure roll 120 is pressed against it, but it is not limited to this configuration. For example, the pressure roll 120 may follow the rotation of the fixing belt 142 in the -R direction and +R direction while pressed against the fixing belt 142.

[0125] Furthermore, the rotating body of this disclosure is not limited to a pressure roll, but may also be a pressure member such as a pressure drum. Also, the fixing member of this disclosure is not limited to a fixing belt, but may also be a fixing member such as a fixing film. Furthermore, the heating member of this disclosure is not limited to a planar heating element, but may also be a heating member composed of, for example, cylindrical lamps or the like.

[0126] In this embodiment, each process is executed on any computer. Furthermore, any computer may execute these processes using a processor as hardware, a program as software, or a combination thereof. In that case, the processor is configured to work in cooperation with the program to execute the various processes in this embodiment, and can function as a unit or means in this embodiment. Also, the execution order of the processes by the processor is not limited to the order described and may be changed as appropriate. Any computer may be a general-purpose computer, a computer designed for a specific purpose, a workstation, or any other system capable of executing each process.

[0127] A processor may consist of one or more hardware components, and the type of hardware is not limited. For example, a processor may consist of a CPU (Central Processing Unit), an MPU (Micro Processing Unit), a programmable logic device such as an FPGA (Field Programmable Gate Array), a dedicated circuit for executing a specific process such as an ASIC (Application Specific Integrated Circuit), a GPU (Graphic Processing Unit), or an NPU (Neural Processing Unit). Furthermore, the type of hardware may be a combination of different types of hardware. When multiple hardware components are configured to execute one or more processes of a processor, these components may reside in physically separate devices or in the same device. Also, in any embodiment, the order of each process performed by the processor is not limited to the order described above and may be changed as appropriate. Hardware is composed of electrical circuits (circuitry) that combine circuit elements such as semiconductor elements.

[0128] Furthermore, the program may be firmware or software such as microcode. Alternatively, the program may be, for example, a group of program modules, each function of which may be implemented by a processor configured to perform its respective function. The program may be program code or multiple code segments stored on one or more non-temporary computer-readable media (e.g., storage media or other storage devices). The program may be divided and stored on multiple non-temporary computer-readable media located on physically separate devices. The program code or code segments may represent any combination of procedures, functions, subprograms, routines, subroutines, modules, software packages, classes, or instructions, data structures, or program statements. The program code or code segments may be connected to other code segments or hardware circuits by sending and receiving information, data, arguments, parameters, or memory contents. The program of this application may also be provided as a program product.

[0129] (Note) (((1))) A solid of rotation and An endless fixing member that forms a clamping region that sandwiches the medium between the rotating body, The clamping region has a contact region that contacts the inner circumference of the fixing member via a lubricant, and the heating member generates heat in the contact region, Processor and Equipped with, The aforementioned processor, In a fixing mode, the fixing member, heated by the heating element, clamps the medium between itself and the rotating body in the clamping region and rotates in the forward direction to fix the image on the medium. A rotation mode in which the heating element generates heat on the upstream side in the forward rotation direction of the contact region and does not generate heat on the downstream side, and the fixing element rotates in the forward rotation direction, and a rotation mode in which the heating element generates heat on the upstream side in the reverse rotation direction of the contact region and does not generate heat on the downstream side, and the fixing element rotates in the reverse rotation direction, Execute Fixing system. (((2))) The aforementioned processor, In the aforementioned rotation mode, After performing one of the forward rotation and the reverse rotation, perform the other of the forward rotation and the reverse rotation. The fixing system described in (((1))). (((3))) The aforementioned processor, In the aforementioned rotation mode, After performing one of the above steps, and after a predetermined period of time has elapsed with the heating element stopped generating heat, perform the other step. The fixing system described in (((2))). (((4))) The aforementioned processor, In at least one of the above rotation modes, After the heating element has generated heat, the fixing element starts to rotate. The fixing system described in any one of (((1))) to (((3))). (((5))) The aforementioned processor, In at least one of the above rotation modes, After the heating element has generated heat, the fixing element is rotated while the heating element is still heated. The fixing system described in (((4))). (((6))) The aforementioned processor, In at least one of the above rotation modes, The rotating body is pressed against the fixing member in the clamping region, and the fixing member is rotated. The fixing system described in any one of (((1))) to (((5))). (((7))) The aforementioned processor, In at least one of the above rotation modes, With the rotating body pressurized against the fixing member in the clamping region, the heating member generates heat, and then the fixing member is rotated. The fixing system described in (((6))). (((8))) An image forming unit that forms an image on a medium, A fixing system according to any one of claims 1 to 7 for fixing an image formed on the medium, An image forming apparatus equipped with the following features.

[0130] According to the configuration of (((1))), image quality defects are suppressed compared to when the processor only performs a fixing mode in which a fixing member heated by a heat-generating element clamps the medium between the rotating body in the clamping region and rotates in the forward direction to fix the image on the medium. According to the configuration of (((2))), image quality defects are suppressed compared to when the processor performs only one of forward or reverse rotation in rotation mode. According to the configuration of (((3))), when the processor performs one operation followed immediately by the other operation in rotation mode, image quality defects are suppressed. According to the configuration of (((4))), in at least one of the operations performed by the processor in rotation mode, image quality defects are suppressed compared to the case where the heat-generating member generates heat after the rotation of the fixing member has started. According to the configuration of (((5))), when the processor performs at least one of the operations in rotation mode, image quality defects are suppressed compared to when the fixing member is rotated while the heat generation of the heat-generating member has stopped. According to the configuration of (((6))), in at least one of the operations performed by the processor in rotation mode, image quality defects are suppressed compared to the case in which the rotating body rotates the fixing member without applying pressure to the fixing member. According to the configuration of (((7))), in at least one of the operations performed by the processor in rotation mode, image quality defects are suppressed compared to the case in which the rotating body is pressed against the fixing member in the clamping region after the heating element has heated up. According to the configuration of (((8))), image quality defects are suppressed compared to when the processor only performs a fixing mode in which the fixing member, heated by the heat-generating element, clamps the medium between the rotating body in the clamping area and rotates in the forward direction to fix the image on the medium. [Explanation of symbols]

[0131] 10 Image forming apparatus 10a Main unit of the device 12 Storage Unit 14 Main operating part 16. Manuscript Reading Unit 18 Conveying section 22. First containment unit 24 Second Detention Unit 26 Third Detention Unit 28. Fourth Detention Unit 30. Transport Route 31 Double-sided transport route 31a Switchback road 32 Dispensing Rolls 33 Hand-pointed path 34 Double-feed prevention roll 36 Conveyor Rolls 38 Conveying device 40 Display section 42 Charger 44 Developer 46 Cleaning parts 48 Transfer Belt 50 Primary Transfer Rolls 52 Secondary transfer roll 54 Auxiliary Rolls 56 rolls 60 Image forming unit 62 Photoconductor Drum 64 Image forming unit 66 Exposure equipment 68 Transfer Unit 70 Controllers 72A CPU (an example of a processor) 72D Storage 72E Bus 74 Input / output section 76 Network Interface 80 Discharge section 90 Fixing System 100 Fixing device 120 Pressure Roll (Example of a Rotating Body) 122 Elastic layer 124 Mandrel 126 Release layer 140 Heating section 142 Fixing belt 144 Heater (an example of a heating element) 144A First heating element 144B Second heating element 144C Third heating element 144S contact area 146 pads 146A Downstream end 146B Upstream end 146C recess 148 Support Member CV transport direction G Grease N Fixing Nip P sheet material (an example of a medium) T transcription position

Claims

1. A solid of rotation and An endless fixing member that forms a clamping region that sandwiches the medium between the rotating body, The clamping region has a contact region that contacts the inner circumference of the fixing member via a lubricant, and the heating member generates heat in the contact region, Processor and Equipped with, The aforementioned processor, In a fixing mode, the fixing member, heated by the heating element, clamps the medium between itself and the rotating body in the clamping region and rotates in the forward direction to fix the image on the medium. A rotation mode in which the heating element generates heat on the upstream side in the forward rotation direction of the contact region and does not generate heat on the downstream side, and the fixing element rotates in the forward rotation direction, and a rotation mode in which the heating element generates heat on the upstream side in the reverse rotation direction of the contact region and does not generate heat on the downstream side, and the fixing element rotates in the reverse rotation direction, Execute Fixing system.

2. The aforementioned processor, In the aforementioned rotation mode, After performing one of the forward rotation and the reverse rotation, perform the other of the forward rotation and the reverse rotation. The fixing system according to claim 1.

3. The aforementioned processor, In the aforementioned rotation mode, After performing one of the above steps, and after a predetermined period of time has elapsed with the heating element stopped generating heat, perform the other step. The fixing system according to claim 2.

4. The aforementioned processor, In at least one of the above rotation modes, After the heating element has generated heat, the fixing element starts to rotate. The fixing system according to claim 1.

5. The aforementioned processor, In at least one of the above rotation modes, After the heating element has generated heat, the fixing element is rotated while the heating element is still heated. The fixing system according to claim 4.

6. The aforementioned processor, In at least one of the above rotation modes, The rotating body is pressed against the fixing member in the clamping region, and the fixing member is rotated. The fixing system according to claim 1.

7. The aforementioned processor, In at least one of the above rotation modes, With the rotating body pressurized against the fixing member in the clamping region, the heating member generates heat, and then the fixing member is rotated. The fixing system according to claim 6.

8. An image forming unit that forms an image on a medium, A fixing system according to any one of claims 1 to 7 for fixing an image formed on the medium, An image forming apparatus equipped with the following features.

Images