Fixing system and image forming apparatus

Abstract

This invention discloses a fixing system and an image forming apparatus. The fixing system comprises: a rotating body; an annular fixing belt that contacts the rotating body to form a fixing engagement portion for fixing an image on a medium; a heating member that contacts the inner periphery of the portion of the fixing belt forming the fixing engagement portion via a lubricant and heats the fixing belt; and a processor that executes a uniform mode in which the fixing belt is rotated while the heating member heats the fixing belt at a temperature higher than the fixing temperature used for fixing the image on the medium.

Description

Technical Field

[0001] This invention relates to a fixing system and an image forming apparatus. Background Technology

[0002] Japanese Patent Application Publication No. 2017-138422 discloses a fixing device, which is a replaceable fixing device, comprising: a fixing component, the fixing component having low heat capacity and being rotatable; a rotating component, the rotating component pressing against the fixing component from its outer surface and rotating thereto; a biting forming component, the biting forming component pressing against the fixing component from its inner surface at a position opposite to the rotating component to form a biting portion; and a lubricant, the lubricant being between the sliding portions of the fixing component and the biting forming component. The fixing device, while clamping and conveying recording material through the biting portion, heats and pressurizes the unfixed toner image onto the recording material. The fixing device is characterized by having at least one temperature sensing element for detecting the temperature of the fixing component or the biting forming component, and having a control unit. The control unit controls the pause timing of the fixing device based on the temperature detection result of the temperature sensing element during a rotation mode implemented at a predetermined time different from the printing operation of the fixing device to allow the lubricant to fuse. Summary of the Invention

[0003] Compared to a fixing mode that only performs fixing on an image on a medium, the present invention suppresses poor fixing on the medium.

[0004] According to a first aspect of the present invention, a fixing system is provided, comprising: a rotating body; an annular fixing belt that contacts the rotating body to form a fixing engagement portion for fixing an image on a medium; a heating member that contacts the inner periphery of the portion of the fixing belt forming the fixing engagement portion via a lubricant and heats the fixing belt; and a processor that executes a uniform mode in which the fixing belt is rotated while the heating member heats the fixing belt at a temperature higher than the fixing temperature when fixing the image on the medium.

[0005] According to a second aspect of the present invention, in the fixing system involved in the first aspect, the processor, during the execution of the uniform mode, causes the fixing belt to rotate at a rotational speed faster than the fixing speed when fixing the image.

[0006] According to a third aspect of the present invention, in the fixing system involved in the second aspect, the processor maintains the rotation of the fixing belt at a rotation speed faster than the fixing speed when fixing the image for a predetermined time during the execution of the uniform mode.

[0007] According to a fourth aspect of the present invention, in the fixing system involved in the second or third aspect, during the execution of the uniform mode, after the temperature of the heating element reaches a temperature higher than the fixing temperature, the processor causes the fixing belt to rotate at a rotational speed faster than the fixing speed when fixing the image.

[0008] According to a fifth aspect of the present invention, in the fixing system involved in any of the first to third aspects, the processor, during the execution of the uniform mode, causes the fixing belt to rotate in a direction opposite to the rotation direction of the fixing belt when fixing the image.

[0009] According to a sixth aspect of the invention, in the fixing system involved in the fifth aspect, the processor rotates the fixing belt in the reverse direction throughout the entire period during which the fixing belt is operated according to the uniform pattern.

[0010] According to the seventh aspect of the present invention, in the fixing system involved in any of the first to sixth aspects, the lubricant is a lubricating oil with a main component of silicone oil as base oil and one or more thickeners selected from inorganic particles and a mixed consistency of 250 or less.

[0011] According to an eighth aspect of the present invention, an image forming apparatus is provided, comprising: an image forming section that forms an image on a medium; and a fixing system according to any one of the first to seventh aspects, wherein the fixing system fixes the image formed on the medium.

[0012] (Effect)

[0013] According to the first scheme, compared with the structure that only performs fixing mode on the image on the medium, it is possible to suppress poor fixing on the medium.

[0014] According to the second scheme, compared with the structure that rotates the fixing belt at a rotational speed lower than the fixing speed when fixing the image during uniform mode execution, fixing defects can be suppressed at an earlier stage.

[0015] According to the third scheme, compared with the structure that intermittently rotates the fixing belt at a rotational speed faster than the fixing speed in uniform mode, the time required for uniform mode can be shortened.

[0016] According to the fourth scheme, compared with a structure that rotates the fixing belt at a rotational speed faster than the fixing speed before the fixing belt reaches a temperature higher than the fixing temperature, the load generated on the fixing belt can be reduced.

[0017] According to the fifth scheme, compared with the case where the fixing belt rotates only along the direction of rotation during fixing in the uniform mode, poor fixing can be suppressed.

[0018] According to the sixth scheme, compared with the structure that rotates the fixing belt in the opposite direction during the process of rotating the fixing belt in uniform mode, fixing defects can be suppressed.

[0019] According to the seventh scheme, compared with lubricants with a mixture consistency exceeding 250, poor fixing can be further suppressed.

[0020] According to the eighth embodiment, an image forming apparatus can be provided that, compared with a structure that heats the fixing belt at a temperature below the fixing temperature when fixing an image on a medium, can suppress poor fixing on the medium. Attached Figure Description

[0021] Figure 1 This is a schematic structural diagram illustrating the image forming apparatus of this embodiment;

[0022] Figure 2 This is a block diagram showing the hardware structure of the controller in this embodiment;

[0023] Figure 3 This is a front sectional view showing the state in which the pressure roller and the fixing belt are separated in the fixing system of this embodiment;

[0024] Figure 4 This is a front sectional view showing the state in which the pressure roller is pressed against the fixing belt in the fixing system of this embodiment;

[0025] Figure 5 This is a flowchart illustrating the modes that the controller in this embodiment can execute;

[0026] Figure 6 This is a flowchart of the controller executing the uniform mode in this embodiment. Detailed Implementation

[0027] <One Implementation Method>

[0028] Referring to the accompanying drawings, an example of a fixing system and image forming apparatus according to an embodiment of the present invention (this embodiment) will be described.

[0029] Furthermore, in the illustration, arrow H represents the vertical direction of the image forming apparatus, and arrow W represents the width direction. The vertical direction and the width direction of the image forming apparatus are orthogonal to each other. However, these directions are defined for ease of explanation; therefore, the structure of the image forming apparatus is not limited to these directions. The term "image forming apparatus" is sometimes omitted in the various directions of the image forming apparatus. Additionally, the +R direction refers to a counterclockwise rotation about the direction orthogonal to both the vertical and width directions (depth direction). The -R direction refers to a clockwise rotation about the depth direction.

[0030] (Image forming apparatus)

[0031] The image forming apparatus 10 forms an image on a sheet component P. The sheet component P is an example of a medium. In the image forming apparatus 10, as... Figure 1 As shown, various components are arranged inside the main body 10a of the device. The image forming apparatus 10 mainly includes a paper receiving unit 12, an active operating unit 14, a conveying unit 18, and a controller 70. The image forming apparatus 10 also includes a display unit 40 as an interface for the user to send and receive information with the image forming apparatus 10.

[0032] (Paper container)

[0033] The paper receiving section 12 receives sheet components P. The paper receiving section 12 has a first receiving section 22, a second receiving section 24, a third receiving section 26, and a fourth receiving section 28. The first receiving section 22, the second receiving section 24, the third receiving section 26, and the fourth receiving section 28 appropriately receive sheet components P of different sizes. Furthermore, the first receiving section 22, the second receiving section 24, the third receiving section 26, and the fourth receiving section 28 each have a feed roller 32 and a re-feeding prevention roller 34. The feed roller 32 feeds out the received sheet components P one by one based on instructions from the controller 70 that manages the operation of each section. The re-feeding prevention roller 34 conveys the sheet components P fed out from the feed roller 32 one by one to the transport path 30 within the image forming apparatus 10.

[0034] (Active Action Section)

[0035] The active unit 14 outputs image data sent from a user terminal (not shown) or document reading unit 16 to a sheet component P conveyed from paper receiving unit 12. The active unit 14 includes an image forming unit 60, a transfer unit 68, and a fixing device 100. The active unit 14 is an example of an image forming unit.

[0036] The image forming unit 60 forms a toner image. A toner image is an example of an image. The image forming unit 60 has image forming units 64K, 64C, 64M, and 64Y that form toner images of yellow (Y), magenta (M), cyan (C), and black (K). Furthermore, in the following description, unless otherwise specified, the Y, M, C, or K at the end of the symbols may sometimes be omitted.

[0037] The image forming unit 64 is configured including a photosensitive drum 62, a charger 42, a developer 44, a cleaning component 46, and an exposure apparatus 66 (66K, 66C, 66M, and 66Y). The charger 42 charges the rotating photosensitive drum 62, and the exposure apparatus 66 exposes the charged photosensitive 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. That is, the image forming apparatus 10 of this embodiment is an electrophotographic device.

[0038] The transfer unit 68 transfers the toner image onto the sheet component P. The transfer unit 68 is located below the image forming unit 60. The transfer unit 68 includes a transfer belt 48, a primary transfer roller 50, a secondary transfer roller 52, an auxiliary roller 54, and a roller 56.

[0039] The transfer belt 48 is formed in a ring shape, and when viewed from the depth direction and the front side, it appears as a triangle with its apex pointing downwards, contacting the image forming section 60 from below in the vertical direction. The depth direction is orthogonal to the vertical and width directions.

[0040] The primary transfer roller 50 (50K, 50C, 50M and 50Y) is a cylindrical shape extending along the depth direction and is configured to correspond to the photosensitive drum 62. Together with the photosensitive drum 62, it holds the transfer belt 48 and transfers the toner image from the photosensitive drum 62 onto the transfer belt 48.

[0041] The secondary transfer roller 52 is a cylindrical shape extending along the depth direction and is positioned below the primary transfer roller 50. It transfers the toner image on the transfer belt 48 to the sheet component P at the transfer position T.

[0042] The auxiliary roller 54 is a cylindrical shape extending along the depth direction and is disposed inside the transfer belt 48, and on the opposite side of the secondary transfer roller 52 across the transfer belt 48.

[0043] Multiple rollers 56 are arranged inside the transfer belt 48, and the transfer belt 48 is wound on them. One of the rollers 56 functions as a drive roller to make the transfer belt 48 rotate in the direction of arrow C in the figure.

[0044] The fixing device 100 is positioned downstream of the transfer position T and fixes the toner image transferred onto the sheet component P onto the sheet component P. Details of the fixing device 100 will be described later.

[0045] (Transmission Department)

[0046] The conveying unit 18 receives and conveys sheet components P one by one from the reload anti-roller 34 or inserted from the outside of the device body 10a. The conveying unit 18 has a conveying path 30, a conveying roller 36, and a conveying device 38.

[0047] Conveyor path 30 is the path that specifies the conveyor direction (hereinafter referred to as "conveyor direction CV") of sheet component P.

[0048] The upstream portion of the conveying path 30 extends upward from bottom to top on one side in the width direction. A manual paper feed path 33 is connected to the upper end of the upstream portion of the conveying path 30.

[0049] The downstream portion of the conveying path 30 extends from one side to the other in the width direction and connects to the discharge section 80 for discharging the sheet component P to the outside of the device body 10a. A double-sided conveying path 31 is connected at the downstream end of the conveying path 30 to convey and reverse the sheet component P in order to form an image on the reverse side of the sheet component P. The double-sided conveying path 31 includes a flipping path 31a, which flips the front and back sides of the sheet component P delivered from the flipping path 31a and feeds it into the upper end of the upstream portion of the conveying path 30 in the conveying direction CV.

[0050] The conveyor rollers 36 are cylindrical in shape and extend along the depth direction, and multiple rollers are arranged along the conveying path 30. The conveyor rollers 36 are arranged in pairs on the main body 10a of the device in a manner that clamps the conveying path 30.

[0051] The conveying device 38 is positioned upstream of the transfer position T in the conveying direction CV, causing the sheet component P to stop temporarily, and then conveying the sheet component P to the secondary transfer position at a predetermined time.

[0052] (Controller)

[0053] The controller 70 is configured as a computer that controls each part of the image forming apparatus 10.

[0054] like Figure 2 As shown, the controller 70 includes a CPU (Central Processing Unit) 72A, a ROM (Read Only Memory) 72B, a RAM (Random Access Memory) 72C, a storage device 72D, an input / output unit 74, and a network interface (network I / F) 76. These components are communicatively connected to each other via a bus 72E.

[0055] CPU 72A is a central processing unit that executes various programs or controls various components. Specifically, CPU 72A reads programs from ROM 72B or storage device 72D and uses RAM 72C as the working area to execute the programs. CPU 72A is an example of a processor constituting a fixing system. CPU 72A performs control and various arithmetic operations on the aforementioned structures according to the programs recorded in ROM 72B or storage device.

[0056] ROM 72B stores various programs and data. RAM 72C serves as the operating area for temporary storage of programs or data. Storage device 72D consists of an HDD (Hard Disk Drive) or an SSD (Solid State Drive) and stores various programs, including the operating system, and various data.

[0057] The input / output unit 74 receives signals between the various components of the image forming apparatus 10 to perform the functions of the image forming apparatus 10. For example, the input / output unit 74 receives signals between the paper receiving unit 12, the active operating unit 14, and the transport unit 18.

[0058] Network I / F76 is an interface used to communicate with other devices such as databases and servers (not shown), using specifications such as Ethernet (registered trademark), FDDI, and Wi-Fi (registered trademark).

[0059] <Details of the fixing device>

[0060] like Figure 3 and Figure 4 As shown, the fixing apparatus 100 includes a pressure roller 120 and a heating unit 140. In the fixing apparatus 100, the pressure roller 120 and the heating unit 140 fix the toner image onto the sheet component P. Specifically, in the fixing apparatus 100, the toner image transferred from the image forming unit 60 to the sheet component P is fixed onto the sheet component P by heating and pressurizing the sheet component P. The fixing apparatus 100, together with the CPU 72A of the controller 70, constitutes a fixing system.

[0061] [Pressure roller]

[0062] The pressure roller 120 is a roller-shaped component along the depth direction. The pressure roller 120 is disposed below the conveying path 30. The pressure roller 120 is rotatably supported on the device body 10a and is driven to rotate in the +R and -R directions by a drive unit (not shown). The pressure roller 120 is an example of a rotating body. Furthermore, the pressure roller 120 can contact / disengage from the conveying path 30 via a contact-disengagement mechanism (not shown). The pressure roller 120 is configured to apply pressure to the sheet component P.

[0063] The pressure roller 120 has a multi-layer structure comprising a mandrel 124, an elastic layer 122, and an anti-stick layer (not shown). The mandrel 124 is a thin-walled cylindrical structure made of steel and is supported on the main body 10a of the device. The elastic layer 122 includes a layer of silicone rubber or the like covering the surface of the mandrel 124. The anti-stick layer (not shown) is a fluoropolymer layer covering the surface of the elastic layer 122.

[0064] [Heating section]

[0065] The heating section 140 is a structure extending along the depth direction. The heating section 140 is disposed above the conveying path 30. The heating section 140 is a structure for melting the toner on the sheet component P. The heating section 140 includes a fixing belt 142, a heater 144, a pad 146, and a support member 148.

[0066] The fixing belt 142 is an annular belt with the depth direction as its axial direction. In the fixing belt 142, an anti-stick layer including fluororesin is provided as needed on the outer peripheral surface of a thin-walled cylindrical substrate made of synthetic resin such as polyimide resin or polyamide-imide resin. The fixing belt 142 is rotatably supported on the apparatus body 10a. When pressed by the pressure roller 120, the fixing belt 142 moves along the -R and +R directions in tandem with the rotation of the pressure roller 120. For example, when pressed by the pressure roller 120, the fixing belt 142 rotates along the +R direction in tandem with the rotation of the pressure roller 120 in the -R direction.

[0067] The heater 144 is a planar heating element disposed along the depth direction on the inner side of the fixing belt 142. The heater 144 is in contact with the inner circumferential surface of the fixing belt 142 when pressed against it by the pressure roller 120. The heater 144 is configured to have its temperature adjustable based on the instruction of the controller 70. The heater 144 heats the fixing belt 142 via lubricating oil G.

[0068] Here, the lubricating oil G is configured to reduce the sliding resistance of the fixing belt 142 and the heater 144 when held between them. The lubricating oil G has a lower viscosity than fluorinated lubricating oil. For example, regarding the mixing consistency specified in JIS K 2220, the lubricating oil G is set to 250 or less. Furthermore, the viscosity of the lubricating oil G at 200°C, measured by a flow meter, is 50–1500 Pa·s. More preferably, this viscosity of the lubricating oil G is 80–1000 Pa·s. Moreover, this viscosity of the lubricating oil G is more preferably 100–500 Pa·s. The weight loss rate of the lubricating oil G after heating and storing at 230°C for 336 hours is 0–20 wt%. More preferably, this weight loss rate of the lubricating oil G is 0–15 wt%. Moreover, this weight loss rate of the lubricating oil G is more preferably 0–10 wt%.

[0069] Lubricating oil G has a structure consisting of a thickener and a base oil. In lubricating oil G, the base oil is silicone oil, preferably dimethyl silicone oil, methylphenyl silicone oil, or diphenyl silicone oil, and may also have some side chains incorporated. The weight-average molecular weight (Mw) of the silicone oil is 10,000 to 100,000. Furthermore, the weight-average molecular weight (Mw) is preferably 10,000 to 60,000. More preferably, the weight-average molecular weight (Mw) is 15,000 to 40,000.

[0070] Furthermore, in lubricating oil G, the thickener is selected from one or more inorganic materials such as melamine cyanurate, boron nitride, carbon black, silica, graphite, molybdenum disulfide, zinc stearate, and tungsten disulfide. The average particle size (D50v) of the thickener is 0.01 to 15 μm. More preferably, this average particle size is 0.1 to 10 μm. Even more preferably, it is 0.1 to 5 μm.

[0071] The base oil in the composition of lubricating oil G has a weight ratio of 40 to 95 wt%. Preferably, the weight ratio is 50 to 85 wt%. More preferably, the weight ratio is 50 to 75 wt%.

[0072] The viscosity of lubricating oil G was determined by the following method. The lubricating oil sample was clamped in a parallel plate with a diameter of 40 mm, and the viscosity was measured by using a dynamic viscoelasticity measuring device (ARES-G2 flow meter, TA Instruments) with a gap of 1 mm, an angular velocity of 0.1 rad / s, and a temperature increase from 40 °C to 200 °C at a rate of 6 °C / min.

[0073] The weight reduction rate of lubricating oil G was calculated based on the weight of a 5g lubricating oil sample collected in an aluminum cup and heated in an oven at 230°C for 336 hours.

[0074] The average particle size of the thickener was determined by the following method: A 2g sample of lubricating oil was collected onto filter paper, and 30g of THF (tetrahydrofuran) was added for filtration, thereby separating the base oil and the thickener. The separated thickener was dispersed in water, and the particle size distribution was determined using a particle size distribution measuring device (LS13320, Beckman Coulter).

[0075] The pad 146 is a block-shaped component disposed along the depth direction inside the fixing belt 142. The pad 146 supports the heater 144 from the outside by covering it inside the fixing belt 142. That is, the pad 146 supports the heater 144 on the upstream side of the upstream and downstream ends 146A and the downstream side of the upstream end 146B in the fixing direction when fixing the toner image onto the sheet component P. The pad 146 is arranged in a position where the downstream end 146A and the upstream end 146B are in contact with the inner peripheral surface of the fixing belt 142 when the pressure roller 120 is pressed against the fixing belt 142. The pad 146 is supported on the device body 10a. The pad 146 faces the outer peripheral surface of the fixing belt 142 toward the outer peripheral surface of the pressure roller 120. The pad 146 also has a recess 146C. The recess 146C is a recessed portion formed on the surface opposite to the support surface of the heater 144.

[0076] The support member 148 is a frame arranged along the depth direction inside the fixing belt 142, and has an inverted U-shape when viewed from the depth direction. The support member 148 is supported by the device body 10a. The support member 148 supports the pad 146 via the recess 146C. When the pressure roller 120 is pressed against the fixing belt 142, the support member 148 receives the pressing pressure of the pressure roller 120 via the heater 144 and the pad 146.

[0077] [Fixed occlusion]

[0078] The fixing engagement portion N will be described. The fixing engagement portion N is formed where the fixing belt 142 contacts the pressure roller 120 to fix the toner image on the sheet component P. In the fixing engagement portion N, the heater 144 heats the fixing belt 142 via lubricating oil G. In other words, the heater 144 contacts the inner circumference of the portion of the fixing belt 142 where the fixing engagement portion N is formed via lubricating oil G. Furthermore, in the fixing engagement portion N, the heated fixing belt 142 melts the toner on the sheet component P. Moreover, in the fixing engagement portion N, the pressure roller 120 presses against the fixing belt 142, clamping the sheet component P together with it. As described above, in the fixing engagement portion N, the toner image is fixed onto the sheet component P.

[0079] 〔model〕

[0080] The two modes executed by the controller 70 are described below. The two modes consist of fixing mode and uniform mode.

[0081] [Fixed Image Mode]

[0082] The fixing mode is set to the mode executed when the image forming apparatus 10 forms an image. In the fixing mode, the toner image is fixed onto the sheet component P based on the fixing temperature and fixing speed.

[0083] The fixing temperature is a predetermined temperature at which the toner image is fixed onto the sheet component P in the fixing engagement section. In this embodiment, the fixing temperature is set as the command temperature from the controller 70 to the heater 144. For example, the fixing temperature is 180°C.

[0084] The fixing speed is a predetermined rotational speed at which the toner image is fixed onto the sheet component P. The fixing speed is the same as the conveying speed of the conveyor unit 18. In this embodiment, the fixing speed is the commanded speed from the controller 70 to the pressure roller 120. In fixing mode, the pressure roller 120 rotates in the -R direction. The rotation of the pressure roller 120 in the -R direction is an example of the fixing direction.

[0085] [Uniform mode]

[0086] The uniform mode is a mode executed during the gap in image formation by the image forming apparatus 10. The uniform mode is executed to uniformize the deviation (non-uniformity) in the thickness direction of the lubricating oil G in the fixing engagement section N. In the uniform mode, uniform temperature, first speed, and second speed are taken into account.

[0087] The uniform temperature is a temperature higher than the fixing temperature. In this embodiment, the uniform temperature is a command temperature set from the controller 70 to the heater 144 based on the temperature characteristics of the lubricating oil G. For example, the uniform temperature is set to be 20°C higher than the fixing temperature. Furthermore, the uniform temperature may also have an amplitude.

[0088] The first speed is a speed slower than the fixing speed. For example, the first speed is 50% to 80% of the fixing speed. In this embodiment, the first speed is the command speed from the controller 70 to the pressure roller 120. Furthermore, the first speed may also have an amplitude.

[0089] The second speed is a speed faster than the fixing speed. For example, the second speed is 120% to 150% of the fixing speed. In this embodiment, the first speed is the command speed from the controller 70 to the pressure roller 120. Furthermore, the second speed may also have an amplitude. In uniform mode, the fixing belt 142 is rotated at either the first speed or the second speed.

[0090] In uniform mode, by maintaining a first speed for a first time, the non-uniformity of the lubricating oil G in the thickness direction is uniformd. The first time is an example of a specified period of time. For example, the first time is set to 30 seconds.

[0091] 〔flow chart〕

[0092] [Pattern Determination]

[0093] Reference Figure 5 The switching of modes in controller 70 is explained.

[0094] In step S10, the CPU 72A of the controller 70 determines whether the fixing mode can be maintained.

[0095] For example, in the following cases (i) to (iii), the CPU72A determines that it cannot maintain the fixing mode and changes to the uniform mode.

[0096] (i) When the image forming apparatus 10 has completed the predetermined number of image forming steps.

[0097] (ii) After a predetermined time has elapsed since the image forming apparatus 10 has completed image forming.

[0098] (iii) The case of receiving an instruction from a user (not shown) of the image forming apparatus 10.

[0099] If the determination result is "yes," indicating affirmation, CPU72A proceeds to step S20. In step S20, CPU72A executes the fixing mode. Then, CPU72A terminates the process.

[0100] On the other hand, if the determination result is "no," indicating negation, CPU72A proceeds to step S30. In step S30, CPU72A executes the uniform mode. Then, CPU72A returns the process to its initial state.

[0101] As shown above, switch modes.

[0102] [Execution of uniform mode]

[0103] Next, refer to Figure 6 The execution of the uniform mode in the controller 70 will be explained. In the uniform mode of this embodiment, the controller 70 heats the fixing belt 142 at a temperature higher than the fixing temperature by the heater 144, while rotating the pressure roller 120 in the -R direction, thereby causing the fixing belt 142 to rotate passively in the +R direction.

[0104] The CPU 72A of the controller 70 moves the pressure roller 120 from the contact disengagement mechanism in step S32. Figure 3 The status shown has switched to Figure 4 The pressure roller 120 is pressed against the fixing belt 142 as shown. Then, CPU72A proceeds to step S34.

[0105] In step S34, CPU72A causes the drive unit to rotate the pressure roller 120 at a first speed along the -R direction. Then, CPU72A proceeds to step S36.

[0106] In step S36, CPU72A heats the fixing belt 142 with heater 144. Then, CPU72A proceeds to step S38.

[0107] In step S38, CPU72A determines whether the temperature of heater 144 is above the uniform temperature.

[0108] If the determination result is "yes", CPU72A proceeds to step S40.

[0109] On the other hand, if the determination result is "no", the CPU72A proceeds to step S36. Then, the CPU72A heats the heater 144 until the temperature of the heater 144 reaches a uniform temperature or higher.

[0110] In step S40, CPU72A causes the drive unit to rotate the pressure roller 120 at a second speed along the -R direction. That is, in this embodiment, after the temperature of the heater 144 reaches a uniform temperature, CPU72A rotates the fixing belt 142 along the +R direction by rotating the pressure roller 120 at a second speed along the -R direction. Then, CPU72A proceeds to step S42.

[0111] In step S42, CPU72A determines whether the time for rotating the pressure roller 120 at the second speed along the -R direction has elapsed beyond the first time.

[0112] If the determination result is "yes", CPU72A proceeds to step S44.

[0113] On the other hand, if the determination result is "no", CPU72A proceeds to step S40. Then, CPU72A continues to rotate the pressure roller 120 at a second speed in the -R direction until the first time has elapsed.

[0114] In step S44, CPU72A causes the drive unit to change the rotational speed of the pressure roller 120 from the second speed to the first speed. Then, CPU72A proceeds to step S46.

[0115] In step S46, CPU72A causes the contact separation mechanism to separate the pressure roller 120 from the fixing belt 142. Then, CPU72A ends the process.

[0116] The above steps execute the uniform mode.

[0117] <Effects>

[0118] Next, the effects of this embodiment will be explained.

[0119] The fixing system of this embodiment includes: a pressure roller 120; an annular fixing belt 142, which contacts the pressure roller 120 to form a fixing engagement portion N for fixing a toner image on a sheet component P; a heater 144, which contacts the inner periphery of the portion forming the fixing engagement portion N on the fixing belt 142 via lubricating oil G and heats the fixing belt 142; and a CPU 72A of a controller 70, which executes a uniform mode in which the heater 144 heats the fixing belt 142 at a uniform temperature higher than the fixing temperature when fixing the toner image on the sheet component P, while rotating the fixing belt 142.

[0120] According to this structure, compared with the structure of the fixing mode that only performs fixing of the toner image on the sheet component P, it is possible to suppress fixing defects on the sheet component P.

[0121] In the fixing system of this embodiment, during the execution of uniform mode, the CPU72A causes the fixing belt 142 to rotate at a second speed that is faster than the fixing speed when fixing the toner image.

[0122] According to this structure, compared with the structure that rotates the fixing belt at a rotational speed lower than the fixing speed when fixing the toner image during uniform mode execution, poor fixing can be suppressed at an earlier stage.

[0123] In the fixing system of this embodiment, during the execution of uniform mode, the CPU72A maintains the rotation of the fixing belt 142 at a second speed that is faster than the fixing speed when fixing the toner image for a first time.

[0124] According to this structure, compared with the structure that intermittently rotates the fixing belt at a rotational speed faster than the fixing speed in uniform mode, the time required for uniform mode can be shortened.

[0125] In the fixing system of this embodiment, when the CPU72A is executing in uniform mode, after the temperature of the heater 144 reaches a uniform temperature, it causes the fixing belt 142 to rotate at a second speed that is faster than the fixing speed when fixing the toner image.

[0126] According to this structure, compared with the structure that rotates the fixing belt at a second speed before the fixing belt reaches a uniform temperature, the load generated on the fixing belt 142 can be reduced.

[0127] In the fixing system of this embodiment, the lubricating oil G is a lubricating oil with a consistency of 250 or less, mainly composed of silicone oil as base oil and one or more thickeners selected from melamine cyanurate, boron nitride, carbon black, silicon dioxide, graphite, molybdenum disulfide, zinc stearate, tungsten disulfide, and other inorganic particles.

[0128] According to this structure, compared with lubricants with a mixture consistency exceeding 250, it is possible to further suppress poor fixing.

[0129] The image forming apparatus 10 of this embodiment includes: an active operating unit 14 that forms a toner image on a sheet member P; and a fixing system that fixes the toner image formed on the sheet member P.

[0130] According to this image forming apparatus, an image forming apparatus 10 can be provided that suppresses poor fixing on the sheet member P compared to a structure that heats the fixing belt at a temperature below the fixing temperature when fixing the toner image on the sheet member P.

[0131] <Variation Example>

[0132] The present invention has been described in detail through specific embodiments, but the present invention is not limited to these embodiments. It will be apparent to those skilled in the art that the present invention can be implemented in various other ways within the scope of the present invention.

[0133] In the above embodiments, a method with Figure 1 The image forming apparatus 10 with the illustrated device layout has been described, but is not limited thereto. For example, the present invention is also applicable to image forming apparatuses having a different device layout than the image forming apparatus 10. Furthermore, in the above embodiment, the active operating unit 14 has been described using a serial color type, but is not limited thereto. The active operating unit may also be a rotary type or a monochrome type. Additionally, the active operating unit is not limited to an indirect transfer method, but may also be a direct transfer method.

[0134] In the uniform mode of the above embodiment, the CPU72A is configured to cause the fixing belt 142 to rotate passively in the +R direction by rotating the pressure roller 120 in the -R direction, but it is not limited to this. For example, the CPU72A may also... Figure 6 In any of steps S34, S40, or S44 shown, the fixing belt 142 is driven to rotate in the -R direction by rotating the pressure roller 120 in the +R direction. The rotation of the fixing belt 142 in the -R direction is an example of rotation in the opposite direction or a reverse rotation. According to this variation, compared to the case where the fixing belt rotates only in the direction of rotation during fixing in uniform mode, fixing defects can be suppressed.

[0135] Furthermore, in the above-described modification, the CPU 72A can also rotate the fixing belt 142 along the -R direction throughout the entire period during the rotation of the fixing belt 142 in the uniform mode execution. Rotation is an example of the operation. That is, the CPU 72A can also rotate the fixing belt 142 along the -R direction in all steps of steps S34, S40, and S44 during the uniform mode execution. In this case, compared to the structure in which the fixing belt is rotated in the opposite direction during a part of the step of rotating the fixing belt in the uniform mode execution, fixing defects can be suppressed.

[0136] The CPU 72A in the above embodiment is configured to rotate the fixing belt 142 at a second speed faster than the fixing speed when fixing the toner image during uniform mode execution, but is not limited thereto. For example, the CPU 72A may also rotate the fixing belt 142 at the same speed as the fixing speed or at a first speed in uniform mode.

[0137] The CPU 72A in the above embodiment is configured to maintain the rotation of the fixing belt 142 at a second speed for a first time during execution in uniform mode, but is not limited thereto. For example, the CPU 72A may also maintain the rotation of the fixing belt 142 at a speed lower than the fixing speed for a first time during execution in uniform mode.

[0138] The CPU 72A in the above embodiment is configured to rotate the fixing belt 142 at a second speed, which is faster than the fixing speed when fixing the toner image, after the temperature of the heater 144 reaches a uniform temperature during uniform mode execution, but is not limited thereto. For example, the CPU 72A may also start increasing the rotation speed of the fixing belt 142 from the fixing speed toward the second speed before the temperature of the heater 144 reaches a uniform temperature during uniform mode execution.

[0139] In the above embodiment, the fixing belt 142 is assumed to move along the -R and +R directions in tandem with the rotation of the pressure roller 120 while being pressed by the pressure roller 120, but this is not limited to this. For example, the pressure roller 120 may also move along the -R and +R directions in tandem with the rotation of the fixing belt 142 while being pressed by the fixing belt 142.

[0140] In the above embodiment, the uniform temperature is defined as the command temperature from the controller 70 to the heater 144, but it is not limited to this. For example, in terms of uniform temperature, the temperature of the inner circumferential surface of the fixing belt 142 can also be measured by a non-contact temperature sensor (not shown).

[0141] In the above embodiment, it is assumed that in step S44, the CPU72A causes the drive unit to change the rotational speed of the pressure roller 120 from the second speed to the first speed, but it is not limited to this. For example, in step S44, the CPU72A may also cause the drive unit to change the rotational speed of the pressure roller 120 from the second speed to zero. That is, the CPU72A may also stop the rotation of the pressure roller 120 in step S44.

[0142] In the above embodiments, it is not limited to Figure 6 The sequence of the process is shown. For example, steps S36 and S34 can be interchanged. That is, the CPU72A can also rotate the pressure roller 120 after the heater 144 heats the fixing belt 142.

[0143] In this embodiment, each process is executed by any computer. Alternatively, any computer may execute these processes via a processor as hardware, a program as software, or a combination thereof. In this case, the processor is configured to cooperate with the program in executing the various processes of this embodiment, and may function as a unit or means of this embodiment. Furthermore, the execution order of the processes performed by the processor is not limited to the order described and may be appropriately varied. Any computer may also be a general-purpose computer, a computer for a specific purpose, a workstation, or other system capable of executing the processes.

[0144] The processor can also be composed of one or more hardware components, and the type of hardware is not limited. For example, the processor can be composed of programmable logic devices such as CPUs (Central Processing Units), MPUs (Micro Processing Units), FPGAs (Field Programmable Gate Arrays), dedicated circuits for performing specific processes such as ASICs (Application Specific Integrated Circuits), GPUs (Graphics Processing Units), or NPUs (Neural Processing Units). Furthermore, the hardware can also be a combination of different types of hardware. When multiple hardware components are configured to execute one or more processes of a certain processor, these multiple hardware components can exist in physically separate devices or in the same device. Additionally, in any embodiment, the order of the processes performed by the processor is not limited to the above order and can be appropriately varied. Moreover, the hardware can be composed of circuits, such as semiconductor elements.

[0145] Furthermore, the program can also be software such as firmware or microcode. Additionally, the program can be, for example, a group of program modules, each of whose functions can be implemented by a processor configured to perform those functions. The program can also be program code or multiple code segments stored in one or more non-transitory computer-readable media (e.g., storage media or other storage devices). The program can also be segmented and stored in multiple non-transitory computer-readable media existing in physically separate devices. Program code or code segments can represent steps, functions, subroutines, routines, subroutines, modules, software packages, classes, or commands, data structures, or any combination of program statements. Program code or code segments can also be connected to other code segments or hardware circuits by sending and receiving information, data, arguments, parameters, or the contents of memory. Furthermore, the program of this application can also be provided as a program product.

[0146] (Postscript) ((1))

[0148] A fixing system, wherein:

[0149] Solid of revolution;

[0150] A ring-shaped fixing belt, which contacts the rotating body to form a fixing engagement portion for fixing an image on a medium;

[0151] A heating element that contacts the inner periphery of the portion of the fixing belt forming the fixing engagement part via a lubricant, and heats the fixing belt; and

[0152] processor,

[0153] The processor

[0154] The uniform mode is executed, in which the fixing belt is rotated while the heating element heats the fixing belt at a temperature higher than the fixing temperature when fixing the image on the medium. ((2))

[0156] According to the fixing system described in (1),

[0157] The processor

[0158] During the execution of the uniform mode, the fixing belt is rotated at a speed faster than the fixing speed when fixing the image. ((3)))

[0160] According to the fixing system described in ((2)), wherein,

[0161] The processor

[0162] During the execution of the uniform mode, the rotation of the fixing belt is maintained at a speed faster than the fixing speed when fixing the image for a specified time. ((4))

[0164] According to the fixing system described in ((2)) or ((3)), wherein,

[0165] The processor

[0166] During the execution of the uniform mode, after the temperature of the heating element reaches a temperature higher than the fixing temperature, the fixing belt is rotated at a speed faster than the fixing speed when fixing the image. ((5)))

[0168] According to any one of ((1)) to ((4)) the fixing system, wherein,

[0169] The processor

[0170] During the execution of the uniform mode, the fixing belt is rotated in a direction opposite to the rotation direction of the fixing belt when fixing the image. (6))

[0172] According to the fixing system described in (5), wherein,

[0173] The processor

[0174] During the entire period of moving the fixing belt according to the uniform pattern, the fixing belt is rotated in the reverse direction. ((7))

[0176] According to any one of ((1)) to ((6)) the fixing system, wherein,

[0177] The lubricant is a lubricating oil with a mixed consistency of less than 250, mainly composed of silicone oil as base oil and one or more thickeners selected from inorganic particles. ((8))

[0179] An image forming apparatus, comprising:

[0180] An image forming unit that forms an image on a medium; and

[0181] The fixing system of any one of ((1)) to ((7)) fixes an image formed on the medium.

[0182] (Effect)

[0183] According to the fixing system of ((1)), compared with the structure of the fixing mode that only performs fixing on the image on the medium, it is able to suppress the fixing failure on the medium.

[0184] According to the fixing system of ((2)), compared with the structure that makes the fixing belt rotate at a rotation speed lower than the fixing speed when fixing the image during the execution of uniform mode, it is possible to suppress fixing defects at an earlier stage.

[0185] According to the fixing system of ((3)), compared with the structure that makes the fixing belt rotate intermittently at a rotational speed faster than the fixing speed in uniform mode, the time required for uniform mode can be shortened.

[0186] According to the fixing system of (4), compared with the structure that rotates the fixing belt at a rotational speed faster than the fixing speed before the fixing belt reaches a temperature higher than the fixing temperature, the load generated on the fixing belt can be reduced.

[0187] According to the fixing system of ((5)), compared with the case where the fixing belt rotates only along the rotation direction during fixing in the uniform mode, it can suppress poor fixing.

[0188] According to the fixing system of ((6)), compared with the structure that rotates the fixing belt in the opposite direction in part of the process of rotating the fixing belt during the execution of uniform mode, it is able to suppress fixing defects.

[0189] According to the fixing system of ((7)), compared with lubricants with a mixing consistency of more than 250, it is able to further suppress poor fixing.

[0190] According to the image forming apparatus ((8)), an image forming apparatus can be provided that can suppress poor fixing on the medium compared with a structure that heats the fixing belt at a temperature below the fixing temperature when fixing an image on the medium.

Claims

1. A fixing system, characterized in that, have: Solid of revolution; A ring-shaped fixing belt, which contacts the rotating body to form a fixing engagement portion for fixing an image on a medium; A heating element that contacts the inner periphery of the portion of the fixing belt that forms the fixing engagement portion via a lubricant and heats the fixing belt. as well as processor, The processor The uniform mode is executed, in which the fixing belt is rotated while the heating element heats the fixing belt at a temperature higher than the fixing temperature when fixing the image on the medium.

2. The fixing system according to claim 1, wherein, The processor During the execution of the uniform mode, the fixing belt is rotated at a speed faster than the fixing speed when fixing the image.

3. The fixing system according to claim 2, wherein, The processor During the execution of the uniform mode, the rotation of the fixing belt is maintained at a speed faster than the fixing speed when fixing the image for a specified time.

4. The fixing system according to claim 2 or 3, wherein, The processor During the execution of the uniform mode, after the temperature of the heating element reaches a temperature higher than the fixing temperature, the fixing belt is rotated at a speed faster than the fixing speed when fixing the image.

5. The fixing system according to any one of claims 1 to 4, wherein, The processor During the execution of the uniform mode, the fixing belt is rotated in a direction opposite to the rotation direction of the fixing belt when fixing the image.

6. The fixing system according to claim 5, wherein, The processor During the entire period of moving the fixing belt according to the uniform pattern, the fixing belt is rotated in the reverse direction.

7. The fixing system according to any one of claims 1 to 6, wherein, The lubricant is a lubricating oil with a mixed consistency of less than 250, mainly composed of silicone oil as base oil and one or more thickeners selected from inorganic particles.

8. An image forming apparatus, characterized in that, have: An image forming unit that forms an image on a medium; and The fixing system according to any one of claims 1 to 7, wherein the fixing system fixes an image formed on the medium.

Images