Fixing device and image forming apparatus

Abstract

An image forming apparatus and a fixing device, the fixing device including: a first fixing member having a belt-shaped member that rotates, a support member disposed corresponding to a fixing region through which a medium passes and supporting the belt-shaped member, and a heating member that heats a temperature of the fixing region to a predetermined fixing temperature; and a second fixing member having an opposing member that is pressed to the support member across the belt-shaped member in the fixing region, the support member having a groove formed on a support surface of the fixing region side along a width direction of the medium.

Description

Technical Field

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

[0002] In image forming apparatuses, the technology described in Patent Documents 1 and 2 below is known regarding fixing devices that heat an unfixed image on a media surface for fixing.

[0003] Patent Document 1 describes a fixing device in which a pressing member 620 and a pressure roller 640 are arranged opposite each other across a fixing belt 630. Patent Document 1 describes that the pressure distribution in the paper feeding direction of the fixing clamping part is set to be the largest on the inlet side in the paper feeding direction, thereby enhancing the gloss of the fixed image.

[0004] Patent Document 2 describes a fixing device in which a fixing roller 611 and a pressure roller 62 are arranged opposite each other across a fixing belt 610. In Patent Document 2, a release pad 64 is provided in the pressing section N, inside the fixing belt 610 and downstream of the fixing roller 611. The document states that the position of the release pad 64 is switched according to the thickness of the paper P to suppress increased gloss on thick paper.

[0005] Patent Document 1: Japanese Patent Application Publication No. 2019-101314 (

[0038] -

[0047] ,

[0055] -

[0086] , Figure 3 , Figures 6-1 1)

[0006] Patent Document 2: Japanese Patent Application Publication No. 2016-177208 (

[0020] -

[0052] , Figures 2-6 ) Summary of the Invention

[0007] The technical challenge of this invention is to improve the gloss of the image compared to the case where the surface of the supporting member on the fixing area side of the supporting strip member is smooth.

[0008] To solve the aforementioned technical problem, the invention described in Solution 1 is a fixing device, which comprises:

[0009] The first fixing member includes a rotating strip member, a support member disposed corresponding to and supporting the fixing area through which the medium passes, and a heating member for heating the temperature of the fixing area to a preset fixing temperature; and

[0010] The second fixing member has a counter member in the fixing area that is pressed against the support member across the strip member.

[0011] The support member has a groove formed on the support surface on the fixing area side, which runs along the width direction of the medium.

[0012] The invention described in Scheme 2 is based on the fixing device described in Scheme 1.

[0013] The groove is formed to such a depth that the portion of the strip member passing through the groove deforms into the groove, and the portion of the strip member deformed into the groove does not contact the bottom of the groove.

[0014] The invention described in Scheme 3 is based on the fixing device described in Scheme 1 or 2.

[0015] The corner portion of the boundary between the support surface and the groove is chamfered.

[0016] The invention described in Scheme 4 is in the fixing device described in any of Schemes 1 to 3.

[0017] The fixing device has a groove whose width increases towards the outer side of the width direction of the medium in the transport direction.

[0018] The invention described in Scheme 5 is in the fixing device described in any of Schemes 1 to 4.

[0019] The fixing device has a slot disposed downstream of the center of the fixing area relative to the transmission direction of the medium.

[0020] The invention described in Scheme 6 is based on the fixing device described in Scheme 5.

[0021] The fixing device includes the groove disposed upstream of the pressure distribution area for stripping the media discharged from the fixing area in the media transport direction.

[0022] The invention described in Scheme 7 is in the fixing device described in any of Schemes 1 to 6.

[0023] The fixing device includes a moving member that moves the position of the support member between a first position where the slot is disposed within the fixing area and a second position where the slot is disposed outside the fixing area.

[0024] The invention described in Scheme 8 is based on the fixing device described in Scheme 7.

[0025] The fixing device includes the moving member, which moves the support member to the first position when a preset high gloss level is selected, and moves the support member to the second position when the high gloss level is not selected.

[0026] The invention described in Scheme 9 is based on the fixing device described in Scheme 8.

[0027] When the high gloss level is selected, the fixing device includes a heating element that increases the fixing temperature; and

[0028] When the high gloss level is selected, the fixing device includes a second fixing member that increases the pressing pressure of the opposing member.

[0029] The invention described in Scheme 10 is an image forming apparatus comprising:

[0030] Image holding components hold the image on a surface;

[0031] A transfer component that transfers the image from the image holding component onto a medium; and

[0032] The fixing device described in any of Schemes 1 to 9 fixes the image transferred onto the medium.

[0033] Invention Effects

[0034] According to the first and tenth embodiments of the present invention, the gloss of the image can be improved compared to the case where the surface of the supporting member on the fixing area side of the supporting strip member is smooth.

[0035] According to the second aspect of the present invention, compared with the case where the portion of the strip member deformed into the groove contacts the bottom of the groove, the gloss of the image can be improved.

[0036] According to the third aspect of the present invention, the lifespan of the strip member can be extended compared to the case without a chamfered shape.

[0037] According to the fourth aspect of the present invention, compared with the case where the width of the groove in the conveying direction is formed to be smaller towards the outer side in the width direction of the medium, wrinkles of the strip member can be suppressed.

[0038] According to the fifth aspect of the present invention, compared with the case where the slot is positioned upstream of the center of the fixing area relative to the transport direction of the medium, the gloss of the image can be improved.

[0039] According to the sixth aspect of the invention, compared with the case where the groove is arranged in the media conveying direction at a position further downstream than the area for the pressure distribution used for stripping, poor fixing can be suppressed.

[0040] According to the seventh aspect of the present invention, fixing in the state where the slot is located in the fixing area and fixing in the state where the slot is located outside the fixing area can be switched by moving the moving member.

[0041] According to the eighth aspect of the present invention, the presence or absence of the groove during fixing can be switched according to the selection of gloss level.

[0042] According to the ninth aspect of the present invention, the gloss of the image can be improved compared to the case where the fixing temperature or the pressing pressure of the opposing member is not increased when high gloss is selected. Attached Figure Description

[0043] The embodiments of the present invention will be described in detail with reference to the following figures.

[0044] Figure 1 This is an overall explanatory diagram of the image forming apparatus according to Embodiment 1 of the present invention;

[0045] Figure 2 This is an enlarged view of the fixing device of Example 1;

[0046] Figure 3 This is an enlarged view of the main part of the support member in Embodiment 1;

[0047] Figure 4 This is a diagram showing the support member of Embodiment 1 as viewed from the direction of arrow IV;

[0048] Figure 5 This is an explanatory diagram of the pressure distribution in the fixing region of Example 1. Figure 5 (A) is an illustration of the pressure distribution of the previous structure. Figure 5 (B) is an explanatory diagram of the pressure distribution in Example 1;

[0049] Figure 6 This is an explanatory diagram showing the position of the support member in Embodiment 1. Figure 6 (A) is an illustration of the high-gloss location. Figure 6 (B) is an illustration of the non-high gloss location;

[0050] Figure 7 This is a diagram illustrating the relationship between the amount of deformation of the developer in the fixing region and its position in the transport direction within the fixing region in Example 1.

[0051] Figure 8 These are explanatory diagrams of a modified example of Example 1. Figure 8 (A) is an explanatory diagram of variation 1. Figure 8 (B) is an explanatory diagram for variation 2. Figure 8 (C) is an explanatory diagram for variation 3. Figure 8 (D) is an explanatory diagram of variation 4.

[0052] Symbol Explanation

[0053] 1-Strip member, 2-Heating member, 4-Support member, 4a-Support surface on the fixing area side, 6-Opposing member, 8-Moving member, 11-Gutter, 11a-Corner portion of the boundary between the support surface and the groove, B+T1+T2-Transfer member, D1-Depth of the groove, F-Fixing device, Fh-First fixing member, Fp-Second fixing member, Py, Pm, Pc, Pk-Image holding member, Q5-Fixing area, Q5a-Area for pressure distribution for peeling, S-Media, U-Image forming device, W1-Width of the groove in the conveying direction. Detailed Implementation

[0054] Next, specific embodiments of the present invention will be described with reference to the accompanying drawings, but the present invention is not limited to the following embodiments.

[0055] In addition, to facilitate understanding of the following explanation, in the attached diagram, the front-back direction is set as the X-axis direction, the left-right direction is set as the Y-axis direction, and the up-down direction is set as the Z-axis direction. The directions or sides represented by the arrows X, -X, Y, -Y, Z, and -Z are respectively set as front, back, right, left, top, bottom, or front side, back side, right side, left side, top side, and bottom side.

[0056] Furthermore, in the diagram, the "·" mark inside the "○" indicates an arrow pointing from the back of the paper to the front, and the "×" mark inside the "○" indicates an arrow pointing from the front of the paper to the back.

[0057] In addition, in the description using the following figures, for ease of understanding, illustrations other than those required for explanation have been appropriately omitted.

[0058] [Example 1]

[0059] Figure 1 This is an overall explanatory diagram of the image forming apparatus according to Embodiment 1 of the present invention.

[0060] exist Figure 1 In this example, a copier U, which is an image forming apparatus, has a user interface UI, which is an operation unit, a scanning device U1, which is an image reading device, a paper feeding device U2, a printing unit U3, which is an image recording member, and a paper ejection unit U4.

[0061] The user interface (UI) may include, for example, a power button or copy start button, a copy quantity setting button, number keys, or a display unit as an input section.

[0062] The scanning device U1 reads the original document (not shown) and converts it into image information, which is then input into the printing unit U3.

[0063] The paper feeding device U2 has multiple paper feeding trays TR1, TR2, TR3, and TR4, which serve as a paper feeding unit. Each paper feeding tray TR1 to TR4 contains recording paper S, which serves as a medium. A paper feeding path SH1, which serves as a medium transport path, extends from each paper feeding tray TR1 to TR4 to the printing unit U3.

[0064] exist Figure 1 In this printer, the printing unit U3 includes a control unit C, which is an example of a control component, and a power supply circuit E that supplies power to each component of the printing unit U3. The control unit C receives image information from the original document read by the scanning device U1 or image information sent from a personal computer, which is an example of an information transmission device (not shown) connected to the copier U.

[0065] The control unit C processes the received image information into printing information (Y: yellow, M: magenta, C: cyan, K: black) and outputs it to a laser drive circuit D, which is an example of a drive circuit for a latent image writing device. The laser drive circuit D outputs the laser drive signal input from the control unit C to exposure devices ROSy, ROSm, ROSc, and ROSk, which are examples of latent image forming components for each color, at a preset time.

[0066] Below each exposure device ROSy to ROSk are image holding units Uy, Um, Uc, and Uk, representing Y, M, C, and K, respectively.

[0067] exist Figure 1 In the example, K: the black image holding unit Uk has a photosensitive drum Pk as an example of an image holding member, a charging corona tube CCk as an example of a charging member, and a photosensitive cleaner CLk as an example of a cleaning member for the image holding member. Furthermore, the image holding units Uy, Um, and Uc of other colors Y, M, and C also have photosensitive drums Py, Pm, and Pc, charging corona tubes CCy, CCm, and CCc, and photosensitive cleaners CLy, CLm, and CLc.

[0068] In addition, in Example 1, the photosensitive drum Pk of color K, which is used frequently and has a lot of surface wear, is configured with a larger diameter than the photosensitive drums Py, Pm, and Pc of other colors, which corresponds to high-speed rotation and achieves a long life.

[0069] After being uniformly charged by charging corona tubes CCy to CCk, photosensitive drums Py to Pk are subjected to laser beams Ly, Lm, Lc, and Lk, which are examples of latent image writing lights output by exposure devices ROSy to ROSk, to form electrostatic latent images on the surfaces of photosensitive drums Py to Pk. These electrostatic latent images on the surfaces of photosensitive drums Py to Pk are then developed by developing devices Gy, Gm, Gc, and Gk, which are examples of developing components, into toner images of various colors: Y (yellow), M (magenta), C (cyan), and K (black).

[0070] The toner image on the surface of the photosensitive drums Py to Pk is transferred sequentially and overlappingly onto the intermediate transfer belt B, which is an example of an intermediate transfer component and an image holding component, through primary transfer rollers T1y, T1m, T1c, and T1k, which serve as examples of primary transfer components, in the primary transfer area Q3. A multicolor image, or so-called color image, is formed on the intermediate transfer belt B. The color image formed on the intermediate transfer belt B is then transferred to the secondary transfer area Q4.

[0071] In addition, when only black image data is used, only the black photosensitive drum Pk and the developing device Gk are used, and only a black toner image is formed.

[0072] After one transfer, the residual toner on the surface of the photosensitive drums Py to Pk is cleaned by the photosensitive cleaners CLy to CLk.

[0073] The toner image forming component is an example of an image forming member, consisting of the image holding units Uy to Uk and the developing devices Gy to Gk.

[0074] The upper part of the printing unit U3 is provided with a toner dispenser U3a, which is an example of a supplementary component. The toner dispenser U3a is detachably equipped with toner cartridges Ky, Km, Kc, and Kk, which are examples of developers. If toner is consumed in the developing units Gy to Gk as the image is formed, toner is supplied from each toner cartridge Ky to Kk to each developing unit Gy to Gk.

[0075] The intermediate transfer belt B, positioned below the photosensitive drums Py to Pk, is tensioned and mounted via an intermediate drive roller Rd (an example of a drive member for the intermediate transfer component), an intermediate tension roller Rt (an example of a tension-applying member for tensioning the intermediate transfer belt B), an intermediate deflection roller Rw (an example of a first offset correction member for correcting the offset and serpentine movement of the intermediate transfer belt B), multiple intermediate idler rollers Rf (an example of a driven member), and a support roller T2a (an example of a counter member for the secondary transfer area). Furthermore, the intermediate transfer belt B is supported so that it can rotate and move in the direction of arrow Ya when driven by the intermediate drive roller Rd.

[0076] The belt module BM, as an example of an intermediate transfer device, is composed of the intermediate drive roller Rd, intermediate tension roller Rt, intermediate guide roller Rw, intermediate idler roller Rf, support roller T2a, primary transfer rollers T1y to T1k, and intermediate transfer belt B. Furthermore, the belt module BM in Embodiment 1 is composed of a unit that can be attached to, detached from, and replaced relative to the printing unit U3.

[0077] Below the support roller T2a, a secondary transfer unit Ut is disposed, serving as an example of a transfer conveying member. The secondary transfer unit Ut includes a secondary transfer roller T2b, serving as an example of a transfer component. The secondary transfer roller T2b is positioned opposite the support roller T2a. The area between the secondary transfer roller T2b and the intermediate transfer belt B constitutes the secondary transfer area Q4. Furthermore, a contact roller T2c, serving as an example of a voltage application contact member, contacts the support roller T2a. At a predetermined time, a secondary transfer voltage of the same polarity as the toner's charge polarity is applied to the contact roller T2c from the power circuit E controlled by the control unit C.

[0078] The rollers T2a to T2c constitute an example of a secondary transfer unit. Furthermore, the intermediate transfer belt B, the primary transfer rollers T1y to T1k, the secondary transfer unit T2, etc., constitute an example of a transfer unit, a transfer device B+T1+T2.

[0079] Below the module BM, a paper transport path SH2 is arranged. Recording paper S supplied from the paper supply path SH1 of the paper supply device U2 is transported to the paper transport path SH2 via a transport roller Ra, which serves as a transport member. The recording paper S on the paper transport path SH2 is fed out in accordance with the timing of the toner image being transported to the secondary transfer area Q4 via a registration roller Rr, which serves as a delivery member, and is guided by paper guides SG1 and SG2, which serve as media guide members, thereby being transported to the secondary transfer area Q4.

[0080] The toner image on the intermediate transfer belt B is transferred to the recording paper S by the secondary transfer unit T2 when passing through the secondary transfer area Q4. Additionally, in the case of a color image, the toner image that was superimposed and transferred once to the surface of the intermediate transfer belt B is also transferred a second time to the recording paper S.

[0081] The intermediate transfer belt B after the secondary transfer is cleaned by a belt cleaner CLB, which is an example of a cleaning member of the intermediate transfer component.

[0082] Recording paper S, with a toner image transferred a second time, is conveyed to a media conveyor belt BH, which is an example of a conveying member. The media conveyor belt BH conveys the recording paper S to a fixing device F, which is an example of a belt unit and a fixing member. The fixing device F has a heating unit Fh, which is an example of a first fixing member, and a pressure unit Fp, which is an example of a second fixing member. A fixing area Q5 is formed in the area where the heating unit Fh and the pressure unit Fp are opposite and in contact.

[0083] The toner image on the recording paper S is heated and fixed by the fixing device F as it passes through the fixing area Q5. The recording paper S, after the toner image is fixed, is discharged by the fixing device F to the discharge tray TRh, which is an example of a discharge section.

[0084] The paper transport path SH is constituted by the symbols SH1, SH2, etc. Furthermore, the paper transport device SU is constituted by the symbols SH, Ra, Rr, SG1, SG2, BH, etc.

[0085] (Explanation of the fixing device)

[0086] Figure 2 This is an enlarged view of the fixing device of Example 1.

[0087] exist Figure 1 In the example of the fixing device F in Embodiment 1, the heating unit Fh has a fixing belt 1 as an example of a belt-shaped member. The fixing belt 1 is tensioned and mounted by a heating roller 2 as an example of a heating member, a steering roller 3 as an example of an offset correction member, a heating pad 4 as an example of a support member, and a tensioning roller 5 as an example of a tension imparting member.

[0088] The fixing tape 1 can be made of any material known in the past, but the substrate is preferably made of a polyimide-based material with high rigidity. Furthermore, the surface layer of the fixing tape 1 is preferably made of a fluoropolymer resin or other material with high release properties, such as molten toner or paper powder.

[0089] In Example 1, the heating roller 2 has a heater 2a built inside as an example of a heating element. The heating roller 2, heated by the heater 2a, heats the fixing belt 1 it contacts.

[0090] The steering roller 3 corrects the serpentine or offset motion of the fixing belt 1.

[0091] The heating pad 4 supports the fixing belt 1 via its lower surface 4a, which serves as an example of a support surface. The heating pad 4 is positioned opposite the pressure roller 6 of the pressure unit Fp. The fixing region Q5 is formed in the area between the fixing belt 1 supported by the heating pad 4 and the pressure roller 6, which serves as an example of an opposing member. Therefore, the unfixed image of the recording paper S passing through the fixing region Q5 is heated and pressurized simultaneously, thereby fixing it onto the recording paper S.

[0092] Tensioning roller 5 applies tension to fixing belt 1.

[0093] Figure 3 This is an enlarged view of the main part of the support member in Embodiment 1.

[0094] Figure 4 This is a diagram showing the support member of Embodiment 1 as viewed from the direction of arrow IV.

[0095] exist Figure 3 , Figure 4 In the embodiment 1, a groove 11 is formed on the lower surface 4a of the heating pad 4. The groove 11 is formed along the front-back direction, that is, the width direction of the recording paper S.

[0096] The depth D1 of the groove 11 is formed such that the portion 1a of the fixing belt 1 that passes through the groove 11 deforms into the groove 11 without contacting the bottom of the groove 11. Therefore, based on the amount of portion 1a entering the groove 11, determined by the rigidity of the fixing belt 1 or the pressure from the pressure roller 6, the depth D1 of the groove 11 is set to a sufficient depth so that the entering portion 1a does not contact the bottom of the groove 11.

[0097] Furthermore, the corner 11a of the boundary between the groove 11 and the lower surface 4a of the heating pad 4 is formed into a chamfered shape, i.e., an R-shape. Therefore, compared to the case where the corner 11a is not chamfered, excessive load and stress on the fixing belt 1 at the corner 11a can be suppressed. Thus, wear or reduction in the lifespan of the fixing belt 1 can be suppressed. The size of the R-shape varies depending on the rigidity of the fixing belt 1 or the pressure of the pressure roller 6, but the surface pressure at the lower surface 4a is 5 kgf / cm². 2 In the case of approximately 0.3 mm, for example, it is preferable to set R: radius to approximately 0.3 mm.

[0098] Furthermore, in the groove 11 of Embodiment 1, the width W1 in the moving direction (Y direction) of the fixing belt 1 is formed as a constant width throughout the entire region in the width direction (X direction) of the fixing belt 1. The width W1 varies depending on the rigidity of the fixing belt 1 or the pressure of the pressure roller 6, but the surface pressure at the lower surface 4a is 5 kgf / cm². 2 In the case of approximately 2mm, it is preferable to set the width W1 to approximately 2mm. This is because if the width W1 is too narrow, the fixing belt 1 will hardly enter the groove 11, and if the width W1 is too wide, the fixing belt 1 that enters the groove 11 will easily bend, thereby reducing its lifespan due to bending stress.

[0099] Furthermore, in Example 1, the groove 11 is positioned downstream of the center of the fixing region Q5, relative to the conveying direction of the recording paper S, i.e., the moving direction of the fixing belt 1. In the fixing region Q5, the developer on the surface of the recording paper S melts upon heating. Therefore, compared to the upstream side of the fixing region Q5, the developer becomes more molten and its viscosity decreases downstream. In Example 1, the groove 11 is positioned downstream of the fixing region Q5 where the developer viscosity decreases.

[0100] Figure 5 This is an explanatory diagram of the pressure distribution in the fixing region of Example 1. Figure 5 (A) is an illustration of the pressure distribution of the previous structure. Figure 5 (B) is an explanatory diagram of the pressure distribution in Example 1.

[0101] In Example 1, the slot 11 is positioned upstream in the transport direction of the recording paper S, compared to the area (peeling pressure area Q5a) used for the pressure distribution of the recording paper S discharged from the fixing area Q5. Figure 5 In (A), in a conventional structure without the groove 11, to prevent the recording paper from winding onto the fixing belt, pressure is increased at the downstream end 01 of the fixing area to peel the recording paper off the fixing belt. If this pressure increase is greater, the peelability is improved. However, if the pressure increase (pressure difference) is too large, it leads to reduced image quality, paper wrinkling, and worsened paper bending (curling). Figure 5 In (B), in Example 1, the groove 11 is formed at a position upstream of the peeling pressure region Q5a. For example... Figure 5 As shown in (B), the pressure is locally reduced in the portion Q5b where the groove 11 is formed. If this localized pressure reduction occurs in the peeling pressure region Q5a, the subsequent pressure rise becomes too rapid. Therefore, compared to the case where the groove 11 is arranged within the peeling pressure region Q5a, in Embodiment 1, peelability is maintained and image quality degradation is suppressed.

[0102] Figure 6 This is an explanatory diagram showing the position of the support member in Embodiment 1. Figure 6 (A) is an illustration of the high-gloss location. Figure 6 (B) is an illustration of the non-high gloss location.

[0103] In Embodiment 1, the heating pad 4 is supported by a movable bracket 8, which serves as an example of a moving member. The movable bracket 8 of Embodiment 1 is rotatable, supported around a rotation center 8a. Figure 6 In this embodiment, the movable bracket 8 can be positioned at a high-gloss position, which is an example of the first position (see reference). Figure 6(A) and a non-high gloss position as an example of the second position (refer to) Figure 6 Move between (B). Figure 6 In (A), at the high gloss position, a groove 11 is arranged within the fixing area Q5. Figure 6 In (B), at a non-high gloss position, the groove 11 is configured outside the fixing area Q5.

[0104] From a motor 9, which serves as an example of a drive source, the drive is transmitted to a movable bracket 8 via a drive transmission system such as gears (not shown), enabling it to rotate.

[0105] Furthermore, the pressure roller 6 is configured to adjust the force applied to the heating pad 4 via the pressure adjustment mechanism 21.

[0106] The heating unit Fh in Example 1 consists of the fixing belt 1 or heating roller 2, steering roller 3, heating pad 4, tension roller 5, movable bracket 8, motor 9, and spring (not shown) that presses the tension roller 5.

[0107] Furthermore, the pressurizing unit Fp of Embodiment 1 is constituted by the pressurizing roller 6 or the pressure adjustment mechanism 21, etc.

[0108] (Description of the control unit in Example 1)

[0109] exist Figure 2 In this copier U, the control unit (controller) C has an input / output interface (I / O) for inputting and outputting signals to the outside. Furthermore, the control unit C has a ROM (Read-Only Memory) storing programs and information for performing necessary processing. The control unit C also has a RAM (Random Access Memory) for temporarily storing necessary data. Finally, the control unit C has a CPU (Central Processing Unit) that performs processing corresponding to the programs stored in the ROM, etc. Therefore, the control unit C in Embodiment 1 is composed of a small information processing device, i.e., a so-called microcomputer. Thus, the control unit C can perform various functions by executing programs stored in the ROM, etc.

[0110] The control unit C in Embodiment 1 controls the device in the following manner: it inputs a signal from a signal output element and outputs a signal to the controlled element.

[0111] (Functions of Control Unit C)

[0112] The control unit C in Embodiment 1 has the following functional components (functional modules, program modules).

[0113] The fixing control component C1 includes a fixing temperature control component C11, a rotation control component C12, a pressure pad movement control component C13, and a pressure control component C14. The fixing control component C1 controls the operation and stop of the fixing device F.

[0114] The fixing temperature control component C11 controls the opening and closing of the heater 2a to maintain the temperature of the fixing belt 1 at a preset fixing temperature. When an image forming operation begins, the fixing temperature control component C11 starts controlling the heater 2a to reach the fixing temperature. When the operation ends, the fixing temperature control component C11 closes the heater 2a. In the case of setting to "high gloss," compared to setting to "non-high gloss," the fixing temperature control component C11 of Embodiment 1 controls the fixing temperature at a higher temperature to increase gloss and brightness.

[0115] The rotation control member C12 controls the rotation of the pressure roller 6. Therefore, the control of the rotation of the pressure roller 6 also indirectly controls the rotation of the driven fixing belt 1. When the operation starts, the rotation control member C12 of Embodiment 1 drives the pressure roller 6, and when the operation ends, it stops. In Embodiment 1, the method of driving the pressure roller 6 to drive the fixing belt 1 to rotate is illustrated, but it is not limited to this. For example, it is also possible to drive the heating roller 2 to drive the pressure roller 6 to rotate.

[0116] The pressure pad movement control member C13 controls the motor 9 to move the heating pad 4. In Embodiment 1, the pressure pad movement control member C13 moves the movable bracket 8 according to the gloss setting input by the user in the printing settings, namely either "high gloss" or "normal: non-high gloss," so that the movable bracket 8 moves between a high gloss position and a non-high gloss position. That is, when set to high gloss, the heating pad 4 is moved to the high gloss position; when set to non-high gloss, the heating pad 4 is moved to the non-high gloss position.

[0117] The pressure control component C14 controls the pressure adjustment mechanism 21 to control the pressing pressure of the pressure roller 6. When set to "high gloss", compared to the case set to "non-high gloss", the pressure control component C14 of Embodiment 1 controls the pressing force to be high, so as to increase the gloss and brightness.

[0118] (The function of Example 1)

[0119] In the fixing apparatus F of Embodiment 1, which has the aforementioned structure, the image on the recording paper S passes through the fixing region Q5. When set to high gloss, the fixing temperature or fixing pressure is higher compared to a non-high gloss setting. Therefore, under high gloss setting, the developer tends to become more molten, and the pressure on the developer also increases. The fewer minute irregularities on the surface of the fixed developer, the closer it is to a mirror finish, resulting in improved gloss and brightness. Therefore, the more molten the developer, the easier it is to reduce minute irregularities, and the higher the pressure, the easier it is to reduce minute irregularities.

[0120] In Example 1, a groove 11 is formed midway through the fixing region Q5. At the location of the groove 11, a portion 1a of the fixing belt 1 is partially and temporarily inserted into the groove 11. Therefore, deformation occurs between the fixing belt 1 and the recording paper S. Consequently, the recording paper S follows the pressure roller 6 and rotates, thus maintaining its rotational speed. Conversely, on the fixing belt 1 side, in the portion 1a entering the groove 11, deformation and misalignment occur between the recording paper S and the fixing belt 1. Here, it is presumed that upstream of the groove 11, pressure is released, and the paper speed increases; downstream of the groove 11, pressure is applied again, braking the recording paper S and slowing its speed. Therefore, it is presumed that in the portion passing through the groove 11, a speed difference is generated between the fixing belt 1 and the recording paper S, causing the fixing belt 1 to scrape the developer on the surface of the recording paper S.

[0121] Therefore, when the developer on the fixing belt 1 side of the recording paper S passes through the groove 11, the surface of the developer is subjected to force from the surface of the fixing belt 1 in a scraping manner. Therefore, the minute irregularities on the surface of the developer after fixing are easily reduced. Therefore, the gloss is improved. Therefore, in Embodiment 1 with the groove 11, compared to the case where the lower surface 4a on the fixing area Q5 side of the heating pad 4 supporting the fixing belt 1 is smooth, the gloss of the image can be improved.

[0122] In Patent Document 1, the pressure distribution is set to be maximum on the inlet side in the paper feeding direction. However, at the inlet, the developer has only just begun to melt, which presents a problem that the brightness cannot be sufficiently improved. Furthermore, if the pressure distribution decreases on the outlet side, there is also a problem of reduced paper peelability.

[0123] In Patent Document 2, the spacing between the fixing roller 611 and the peeling pad 64 is changed. However, in structures using two components, such as those in Patent Document 2... Figure 6 As described, the depressions and drops in the pressure distribution become excessive. Therefore, there are problems with image misalignment or uneven brightness.

[0124] In contrast to these, in Embodiment 1, compared to Patent Document 1, the groove 11 formed on the lower surface 4a can improve gloss while maintaining peelability. Furthermore, compared to Patent Document 2, the pressure distribution drop is not excessive, which can suppress fixing defects such as image misalignment and improve gloss.

[0125] Furthermore, in the groove 11 of Embodiment 1, the depth D1 is set to the depth at which the deformed portion 1a does not contact the bottom of the groove 11. Therefore, when the fixing belt 1 contacts the bottom of the groove 11, the deformation of the fixing belt 1 may be insufficient, but in the non-contact Embodiment 1, the fixing belt 1 can be sufficiently deformed. Therefore, compared with the contact case, the gloss can be significantly improved.

[0126] Figure 7 This is a diagram illustrating the relationship between the amount of deformation of the developer in the fixing region and its position in the transport direction within the fixing region in Example 1.

[0127] Furthermore, in Embodiment 1, the groove 11 is positioned further downstream than the center of the fixing region Q5. When positioned upstream of the fixing region Q5, the slope of the developer deformation becomes gentler compared to the downstream side. That is, as... Figure 7 As shown by the dashed line, regarding the deformation of the developer in the portion of tank 11, i.e., the slope of the increase in smoothness, when tank 11 is located on the upstream side, the developer has not yet fully melted, has high viscosity, and is not easily smoothed. In contrast, as... Figure 7 As shown by the solid line, when groove 11 is positioned on the downstream side, the slope of a portion of groove 11 increases. Therefore, positioning groove 11 on the downstream side improves gloss compared to positioning it on the upstream side of the fixing region Q5.

[0128] Furthermore, in Embodiment 1, the heating pad 4 is moved to a high gloss position under the "high gloss" setting and to a non-high gloss position under the "normal: non-high gloss" setting. Therefore, in cases where a low gloss image is desired, the slot 11 can be moved outside the fixing area Q5 to prevent increased gloss.

[0129] (A variation of Example 1)

[0130] Figure 8 These are explanatory diagrams of a modified example of Example 1. Figure 8 (A) is an explanatory diagram of variation 1. Figure 8 (B) is an explanatory diagram for variation 2. Figure 8 (C) is an explanatory diagram for variation 3. Figure 8 (D) is an explanatory diagram of variation 4.

[0131] In the groove 11 of Embodiment 1, the width W1 is formed as a constant width throughout the entire region in the width direction (X direction) of the fixing belt 1, but is not limited to this. For example, as Figure 8 As shown, it can be configured to have a width W1 that increases towards the outer edge of the band width direction. That is, as... Figure 8 As shown in (A), the width W1 can be configured to increase linearly from the center outwards in the width direction. Furthermore, as... Figure 8 As shown in (B), the width W1 can be configured to curve outwards from the center in the width direction. Furthermore, as... Figure 8 As shown in (C), it can also be configured as follows: the upstream corner 11a1 of the groove 11 is set to be straight along the width direction, and the downstream corner 11a2 is set to become more curved as it moves outward in the width direction, thereby increasing the width W1. Furthermore, as... Figure 8 As shown in (D), angles 11a1 and 11a2 can be set as parallel to... Figure 8 (C) The opposite relationship.

[0132] If the width W1 increases towards the outer edge in the belt width direction, then when the fixing belt 1 or recording paper S passes through the slot 11, the fixing belt 1 or recording paper S is subjected to a force towards the outer edge in the belt width direction. Therefore, if it is subjected to a force towards the inner edge in the width direction, wrinkles may be generated on the fixing belt 1 or recording paper S, but by setting it as such... Figure 8 The structure shown can suppress wrinkles.

[0133] (Example of the change)

[0134] The embodiments of the present invention have been described in detail above, but the present invention is not limited to the described embodiments, and various modifications can be made within the scope of the spirit of the present invention as described in the patent claims. Examples of modifications of the present invention (H01) to (H010) are illustrated below.

[0135] (H01) In the embodiment described, a copier U is shown as an example of an image forming apparatus, but it is not limited thereto. For example, it can also be composed of a fax machine, a printer, or a multifunction device.

[0136] (H02) In the embodiment described above, an image forming apparatus using four colors of developer is illustrated, but it is not limited to this. For example, it can also be applied to a monochrome image forming apparatus or an image forming apparatus using three or fewer colors or five or more colors.

[0137] (H03) In the embodiment described above, the shape of the heating pad 4 is not limited to the shape illustrated in the embodiment. It can be configured such that the surface on the fixing region Q5 side is a curved surface or any other shape.

[0138] (H04) In the embodiment described above, the heater 2a, which serves as a heating element, is built into the heating roller 2, but this is not a limitation. It is also possible to build the heater into the heating pad 4.

[0139] (H05) In the embodiment described above, the movable bracket 8 is shown to rotate, but it is not limited to this. It can also be configured to move in parallel. Furthermore, in an image forming apparatus where the gloss level cannot be selected, it can also be configured such that the heating pad 4 does not move.

[0140] (H06) In the embodiment described, the depth D1 of the groove 11 is preferably set to a depth at which the fixing belt 1 does not contact the bottom surface, but it can also be set to a depth at which it contacts the bottom surface.

[0141] (H07) In the embodiment described, for example, it is preferred to provide a chamfer shape at corner 11a, but it is also possible to provide a structure without a chamfer shape.

[0142] (H08) In the embodiment described, the groove 11 is preferably located on the downstream side of the fixing region Q5, but is not limited thereto. It can also be located in the central part of the fixing region Q5 or in the upstream part other than the upstream end.

[0143] (H09) In the embodiment described, the groove 11 is preferably located upstream of the peeling pressure region Q5a, but is not limited thereto. It can also be located in the peeling pressure region Q5a when the risk of image quality degradation due to the setting of the pressure of the pressure roller 6 is low.

[0144] (H010) In the embodiments described, for example, it is preferable to change the fixing temperature or fixing pressure according to the setting of gloss, but it is also possible to set it to a constant regardless of the setting of gloss.

[0145] (Postscript) (1)

[0147] A fixing device comprising:

[0148] The first fixing member includes a rotating strip member, a support member disposed corresponding to and supporting the fixing area through which the medium passes, and a heating member for heating the temperature of the fixing area to a preset fixing temperature; and

[0149] The second fixing member has a counter member in the fixing area that is pressed against the support member across the strip member.

[0150] The support member has a groove formed on the support surface on the fixing area side, which runs along the width direction of the medium. (2)

[0152] According to the fixing device described in (1), wherein,

[0153] The groove is formed to such a depth that the portion of the strip member passing through the groove deforms into the groove, and the portion of the strip member deformed into the groove does not contact the bottom of the groove. (3)

[0155] According to the fixing device described in (1) or (2), wherein,

[0156] The corner portion of the boundary between the support surface and the groove is chamfered. (4)

[0158] According to any one of (1) to (3), the fixing device, wherein,

[0159] The fixing device has a groove whose width increases towards the outer side of the width direction of the medium in the transport direction. (5)

[0161] According to any one of (1) to (4) the fixing device, wherein,

[0162] The fixing device has a slot disposed downstream of the center of the fixing area relative to the transmission direction of the medium. (6)

[0164] According to the fixing device described in (5), wherein,

[0165] The fixing device includes the groove disposed upstream of the pressure distribution area for stripping the media discharged from the fixing area in the media transport direction. (7)

[0167] According to any one of (1) to (6), the fixing device, wherein,

[0168] The fixing device includes a moving member that moves the position of the support member between a first position where the slot is disposed within the fixing area and a second position where the slot is disposed outside the fixing area. (8)

[0170] According to the fixing device described in (7), wherein,

[0171] The fixing device includes the moving member, which moves the support member to the first position when a preset high gloss level is selected, and moves the support member to the second position when the high gloss level is not selected. (9)

[0173] According to the fixing device described in (8), wherein,

[0174] When the high gloss level is selected, the fixing device includes a heating element that increases the fixing temperature; and

[0175] When the high gloss level is selected, the fixing device includes a second fixing member that increases the pressing pressure of the opposing member. (10)

[0177] An image forming apparatus comprising:

[0178] Image holding components hold the image on a surface;

[0179] A transfer component that transfers the image from the image holding component onto a medium; and

[0180] The fixing device of any one of (1) to (9) fixes the image transferred onto the medium.

[0181] According to the fixing device involved in (1), the gloss of the image can be improved compared with the case where the surface of the fixing area side of the supporting member of the supporting strip member is smooth.

[0182] According to the fixing device involved in (2), compared with the case where the part of the strip member deformed into the groove contacts the bottom of the groove, the gloss of the image can be improved.

[0183] According to the fixing device involved in (3), the life of the strip member can be extended compared with the case without a chamfered shape.

[0184] According to the fixing device involved in (4), compared with the case where the width of the groove in the conveying direction is formed smaller towards the outer side in the width direction of the medium, the wrinkles of the strip member can be suppressed.

[0185] According to the fixing device involved in (5), compared with the case where the slot is positioned upstream of the center of the fixing area relative to the transport direction of the medium, the gloss of the image can be improved.

[0186] According to the fixing device involved in (6), compared with the case where the groove is arranged in the media conveying direction at a position further downstream than the area for the pressure distribution used for stripping, poor fixing can be suppressed.

[0187] According to the fixing device involved in (7), fixing in the state where the slot is in the fixing area and fixing in the state where the slot is outside the fixing area can be switched by moving the moving member.

[0188] According to the fixing device involved in (8), the presence or absence of the groove during fixing can be switched according to the selection of gloss.

[0189] According to the fixing device involved in (9), the gloss of the image can be improved compared with the case where the fixing temperature or the pressing pressure of the opposing member is not increased when high gloss is selected.

[0190] According to the image forming apparatus involved in (10), the gloss of the image can be improved compared to the case where the surface of the fixing area side of the support member supporting the strip member is smooth.

[0191] The embodiments of the present invention described above are provided for illustrative purposes. Furthermore, these embodiments do not encompass the entirety of the invention, nor do they limit the invention to the disclosed methods. It will be apparent to those skilled in the art that various modifications and variations will be readily understood. These embodiments were chosen and described to most readily explain the principles and applications of the invention. Thus, those skilled in the art can understand the invention through various modifications that are assumed to be optimized for specific uses of various embodiments. The scope of the invention is defined by the foregoing claims and their equivalents.

Claims

1. A fixing device comprising: The first fixing member includes a rotating strip member, a support member disposed corresponding to and supporting the strip member in a fixing area through which the medium passes, and a heating member for heating the temperature of the fixing area to a preset fixing temperature; and The second fixing member has a counter member in the fixing area that is pressed against the support member across the strip member. The support member has a groove formed on the support surface on the fixing area side, which runs along the width direction of the medium.

2. The fixing device according to claim 1, wherein, The groove is formed to such a depth that the portion of the strip member passing through the groove deforms into the groove, and the portion of the strip member deformed into the groove does not contact the bottom of the groove.

3. The fixing device according to claim 1 or 2, wherein, The corner portion of the boundary between the support surface and the groove is chamfered.

4. The fixing device according to any one of claims 1 to 3, wherein, The fixing device has a groove whose width increases towards the outer side of the width direction of the medium in the transport direction.

5. The fixing device according to any one of claims 1 to 4, wherein, The fixing device has a slot disposed downstream of the center of the fixing area relative to the transmission direction of the medium.

6. The fixing device according to claim 5, wherein, The fixing device includes the groove disposed upstream of the pressure distribution area for stripping the media discharged from the fixing area in the media transport direction.

7. The fixing device according to any one of claims 1 to 6, wherein, The fixing device includes a moving member that moves the position of the support member between a first position where the slot is disposed within the fixing area and a second position where the slot is disposed outside the fixing area.

8. The fixing apparatus according to claim 7, wherein, The fixing device includes the moving member, which moves the support member to the first position when a preset high gloss level is selected, and moves the support member to the second position when the high gloss level is not selected.

9. The fixing apparatus according to claim 8, wherein, When the high gloss level is selected, the fixing device includes a heating element that increases the fixing temperature; and When the high gloss level is selected, the fixing device includes a second fixing member that increases the pressing pressure of the opposing member.

10. An image forming apparatus comprising: Image holding components hold the image on a surface; A transfer component that transfers the image from the image holding component onto a medium; and The fixing apparatus according to any one of claims 1 to 9 fixes an image transferred onto the medium.

Images