Fixing apparatus and image forming apparatus
By rotating the removal member at a different speed relative to the fixing member and using distinct drive sources, the cleaning performance is enhanced, addressing the challenge of deposit removal on fixing members with large surface roughness.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Patents
- Current Assignee / Owner
- FUJIFILM BUSINESS INNOVATION CORP
- Filing Date
- 2022-03-25
- Publication Date
- 2026-06-30
Smart Images
Figure 0007881956000001 
Figure 0007881956000002 
Figure 0007881956000003
Abstract
Description
Technical Field
[0001] The present invention relates to a fixing device and an image forming apparatus.
Background Art
[0002] For example, in Patent Document 1, the main part of a fixing belt module includes a fixing belt, a fixing roller that rotates while stretching the fixing belt, a stretching roller that stretches the fixing belt from the inside, a stretching roller that stretches the fixing belt from the outside, a posture correction roller that corrects the posture of the fixing belt between the fixing roller and the stretching roller, a peeling pad disposed at a position near the fixing roller in a downstream region within a nip portion that is a region where the fixing belt module and a pressure roller are in pressure contact, and a stretching roller (idler roller) that stretches the fixing belt downstream of the nip portion. Also, a configuration including a cleaning web for cleaning the surface of the stretching roller is disclosed.
Prior Art Documents
Patent Documents
[0003]
Patent Document 1
Summary of the Invention
Problems to be Solved by the Invention
[0004] Here, in a configuration in which deposits on a fixing member are transferred to a removal member by bringing the removal member into contact with the outer peripheral surface of the fixing member, it is difficult to remove deposits that have entered recesses of a fixing member having a large surface roughness on the outer peripheral surface with a removal member that rotates at the same speed, and there is a risk that the remaining deposits will re-transfer to the next recording medium. An object of the present invention is to improve the cleaning performance by the removal member as compared with the case where the fixing member and the removal member rotate at the same speed. <00000The invention described in claim 1 comprises: a fixing member having an outer peripheral surface and an inner peripheral surface, rotatably mounted, contacting the surface on which an image is formed in a recording material, and fixing the image to the recording material; a rotating member rotatably mounted, having a contact surface on its outer circumference that contacts the inner peripheral surface of the fixing member; and a removal member positioned in contact with the outer peripheral surface of the fixing member, rotatably mounted, and removing deposits adhering to the outer peripheral surface using a difference in rotational speed relative to the fixing member, wherein the rotating member has a heating source, and the removal member is the rotating member exit section The fixing member is sandwiched between them. At a position opposite to the rotating member A fixing device is provided which the portion of the fixing member that is separated from the rotating member is pressed against the rotating member. 。 Claim 2 The invention described herein comprises: a fixing member having an outer peripheral surface and an inner peripheral surface, rotatably mounted, contacting the surface on which an image is formed in a recording material, and fixing the image to the recording material; a rotating member rotatably mounted, having a contact surface on its outer circumference that contacts the inner peripheral surface of the fixing member; and a removal member positioned in contact with the outer peripheral surface of the fixing member, rotatably mounted, and removing deposits adhering to the outer peripheral surface using a difference in rotational speed relative to the fixing member, wherein the rotating member has a heating source, the difference in rotational speed relative to the fixing member in the removal member is due to the deformation of the fixing member into a shape in which a first portion convex toward the outer peripheral surface and a second portion convex toward the inner peripheral surface are continuous, the second portion being a deformation due to pressing by the removal member at the entrance portion of the fixing member to the rotating member, and a separate removal member being positioned at the exit portion of the fixing member to the rotating member, thereby pressing the portion of the fixing member that is moving away from the rotating member against the rotating member. The second portion is deformed at the exit portion of the fixing member relative to the rotating member due to pressing by the removal member. It is a fixing device. Claim 3 The invention described herein is characterized in that the difference in rotational speed of the removal member compared to the fixing member is achieved by driving the removal member to rotate at a different speed than the fixing member. 2 This is the fixing device described in [reference]. Claim4 The invention described herein is characterized in that the drive is performed by a drive source separate from the drive source that drives the fixing member. 3 This is the fixing device described in [reference]. Claim 5 The invention described herein is characterized in that the drive is performed by a driving force that is branched and decelerated in a transmission system from a drive source that drives the fixing member. 3 This is the fixing device described in [reference]. Claim 6 The invention described herein is characterized in that the removal member at the entrance is a metal roll, and the removal surface of the other removal member at the exit is a nonwoven fabric or felt. 2 The fixing device described above. 。 Claim 7 The invention described herein comprises: an image forming unit that forms an image on a recording material; a fixing member having an outer peripheral surface and an inner peripheral surface, rotatably mounted, contacting the surface on the recording material where the image is formed, and fixing the image to the recording material; a rotating member rotatably mounted, having a contact surface on its outer circumference that contacts the inner peripheral surface of the fixing member; and a removal member positioned in contact with the outer peripheral surface of the fixing member, rotatably mounted, and removing deposits adhering to the outer peripheral surface using the difference in rotational speed relative to the fixing member, wherein the rotating member has a heating source, and the removal member is the same as the rotating member. exit section The fixing member is sandwiched between them. At a position opposite to the rotating member This is an image forming apparatus that is provided to press the portion of the fixing member that is separated from the rotating member against the rotating member. Claim 8The invention described herein comprises: an image forming unit that forms an image on a recording material; a fixing member having an outer peripheral surface and an inner peripheral surface, rotatably mounted, contacting the surface on the recording material where the image has been formed by the image forming unit, and fixing the image to the recording material; a rotating member rotatably mounted, having a contact surface on its outer circumference that contacts the inner peripheral surface of the fixing member; and a removal member positioned in contact with the outer peripheral surface of the fixing member, rotatably mounted, and removing deposits adhering to the outer peripheral surface using a difference in rotational speed relative to the fixing member, wherein the rotating member has a heating source, the difference in rotational speed relative to the fixing member in the removal member is due to the deformation of the fixing member into a shape in which a first portion convex toward the outer peripheral surface and a second portion convex toward the inner peripheral surface are continuous, the second portion being a deformation due to pressing by the removal member at the entrance portion of the fixing member to the rotating member, and a separate removal member being positioned at the exit portion of the fixing member to the rotating member, thereby pressing the portion of the fixing member that is moving away from the rotating member against the rotating member. The second portion is deformed at the exit portion of the fixing member relative to the rotating member due to pressing by the removal member. It is an image forming apparatus. [Effects of the Invention]
[0006] Claim 1 、7 According to this, compared to rotating the fixing member and the removal member at the same speed, the cleaning performance by the removal member can be improved. 。 Claim 2、8 According to The second part is not deformation caused by pressing by the removal member at the exit portion of the fixing member. Compared to other methods, this can improve cleaning performance. Claim 3 According to this, the rotational speed difference can be changed compared to the case where the rotational speed difference is not due to driving the removal member to rotate at a different speed than the fixing member. Claim 4 According to this, the rotational speed difference can be controlled compared to a case where the drive is not performed by a drive source separate from the drive source that drives the fixing member. Claim 5According to the present invention, the number of drive sources can be suppressed as compared with a case where driving is not performed by a driving force branched and decelerated in a transmission system from a drive source that drives a fixing member. Claim 6 According to the present invention, cleaning performance can be improved as compared with a case where a configuration in which a removing member at an entrance portion is a metal roll and a removing surface of another removing member at an exit portion is a non-woven fabric or felt is not adopted. 。
Brief Description of the Drawings
[0007] [Figure 1] It is a diagram showing an image forming apparatus according to the present embodiment. [Figure 2] It is a diagram for explaining the configuration of a fixing device according to the first embodiment. [Figure 3] It is a graph showing circumferential strain in simple contact and S-shaped contact, where the vertical axis represents the strain (%) of the fixing belt and the horizontal axis represents the position (mm) in the direction of arrow C. [ [Figure 4] It is a diagram for explaining the relative movement between the upstream cleaning roll and the fixing belt. [Figure 5] It is a graph showing the amount of wax on the fixing belt before and after cleaning by the upstream cleaning roll in simple contact and S-shaped contact, where the vertical axis is the wax area ratio (%) and the horizontal axis is shown separately before (before the roll) and after (after the roll) the upstream cleaning roll 71 for each of simple contact and S-shaped contact. [Figure 6] It is a diagram for explaining the configuration of a fixing device according to the second embodiment. [Figure 7] It is a diagram for explaining the configuration of a fixing device according to the third embodiment. [Figure 8] It is a block diagram for explaining the fourth embodiment. [Figure 9] It is a block diagram for explaining other embodiments, where (a) is a diagram for explaining the fifth embodiment and (b) is a diagram for explaining the sixth embodiment.
Embodiments for Carrying Out the Invention
[0008] Embodiments of the present invention will be described in detail below with reference to the attached drawings. Figure 1 is a diagram showing an image forming apparatus 1 according to this embodiment. The image forming apparatus 1 shown in the figure is a device that forms an image on a sheet of paper P, which is an example of a recording material. This image forming apparatus 1 is equipped with an image forming unit 10, a paper transport unit 20, and a control unit 40.
[0009] The image forming unit 10 includes an image forming unit 11, an intermediate transfer belt 12, a secondary transfer unit 13, and a fuser 14, which is an example of a fixing device. In this embodiment, the image forming unit 11 is provided with four image forming units 11Y, 11M, 11C, and 11K, each corresponding to one of the four toner colors: Y (yellow), M (magenta), C (cyan), and K (black).
[0010] The image forming units 11Y, 11M, 11C, and 11K are arranged in a line in the direction of movement of the intermediate transfer belt 12, and form a toner image by electrophotography. Each of the image forming units 11Y, 11M, 11C, and 11K includes a photosensitive drum 111, a charging unit 112, an exposure unit 113, a developing unit 114, and a primary transfer unit 115. Each of the image forming units 11Y, 11M, 11C, and 11K forms a toner image of one of the YMCK colors and transfers this toner image onto the intermediate transfer belt 12. As a result, a toner image is formed on the intermediate transfer belt 12 in which the toner images of each of the YMCK colors are superimposed.
[0011] The photoreceptor drum 111 rotates in the direction of arrow A at a predetermined speed. Additionally, an electrostatic latent image is formed on the circumferential surface of the photoreceptor drum 111. The charging unit 112 charges the circumferential surface of the photoreceptor drum 111 to a predetermined potential. The exposure unit 113 irradiates light onto the circumferential surface of the charged photoreceptor drum 111, forming an electrostatic latent image on the circumferential surface of the photoreceptor drum 111. The developing unit 114 forms a toner image by attaching toner to the electrostatic latent image formed on the circumferential surface of the photoreceptor drum 111.
[0012] The primary transfer unit 115 transfers the toner image formed on the circumferential surface of the photoreceptor drum 111 onto the intermediate transfer belt 12. A voltage with the opposite polarity to the charging polarity of the toner is applied to the primary transfer unit 115. As a result, the toner image formed on the circumferential surface of the photoreceptor drum 111 is sequentially electrostatically attracted onto the intermediate transfer belt 12, and a single overlapping color toner image is formed on the intermediate transfer belt 12.
[0013] The intermediate transfer belt 12 is supported by a plurality of roll-shaped members. The intermediate transfer belt 12 is formed in an endless manner and moves in a circulating manner in the direction of arrow B. The intermediate transfer belt 12 also has an outer circumferential surface 12a and an inner circumferential surface 12b. The intermediate transfer belt 12 is used to transport the toner image. In this embodiment, a toner image is formed on the outer surface 12a of the intermediate transfer belt 12, and this toner image is transported to the secondary transfer section 13 by the movement of the intermediate transfer belt 12.
[0014] In this embodiment, a drive roll 121 is provided as a roll-shaped member positioned inside the intermediate transfer belt 12, which is driven by a motor (not shown) to drive the intermediate transfer belt 12. Additionally, an idler roll 123 and a backup roll 132 are provided as roll-shaped members to support the intermediate transfer belt 12. These roll-shaped members are rotatably mounted and pressed against the inner circumferential surface 12b of the intermediate transfer belt 12.
[0015] The paper transport unit 20 is equipped with a paper storage unit 21 that stores multiple sheets of paper P in a stacked state, and a pickup roll 22 that takes out the paper P stored in the paper storage unit 21 and transports it. Furthermore, the paper transport unit 20 is provided with a transport roll 23 that transports the paper P picked up by the pickup roll 22 along the paper transport path 30, and a paper guide unit 24 that guides the paper P transported by the transport roll 23 to the secondary transfer unit 13. Furthermore, the paper transport unit 20 is equipped with a transport belt 25 for transporting the paper P after secondary transfer to the fuser 14, and a paper guide unit 26 for guiding the fixed paper P to the paper discharge unit 27.
[0016] The secondary transfer section 13 is provided with a secondary transfer roll 134 that is positioned in contact with the outer circumferential surface 12a of the intermediate transfer belt 12, and a backup roll 132 that is positioned on the inner circumferential surface 12b side of the intermediate transfer belt 12 and forms a counter electrode for the secondary transfer roll 134. Furthermore, in this embodiment, a metal power supply roll 133 is provided for applying a secondary transfer bias to the backup roll 132. The secondary transfer unit 13 configured in this way transfers the toner image that has been transported to the secondary transfer unit 13 by the intermediate transfer belt 12 onto the transported paper P.
[0017] The fuser 14 is located downstream of the secondary transfer unit 13 in the paper transport direction. The fuser 14 is equipped with a fuser belt module 50 having a heating source and a pressure roll 61 provided opposite the fuser belt module 50. When the paper P that has passed through the secondary transfer section 13 is transported between the fixing belt module 50 and the pressure roll 61, the unfixed toner image on the paper P is melted and fixed onto the paper P. As a result, an image consisting of the toner image is formed on the paper P.
[0018] In a typical fixing process, a roll is brought into contact with the outer surface of the fixing belt, transferring any deposits from the fixing belt to the roll, and then the deposits on the roll are removed using a cleaning web. However, both the fixing belt and the roll have surface roughness, and toner and wax residues adhering to the bottom of these rough surfaces cannot come into contact with the roll, making it difficult to ensure proper cleaning.
[0019] Therefore, in this embodiment, we focus on the difference in rotational speed between the fixing belt 51 (see Figure 2), which moves in a circular motion, and the upstream cleaning roll 71 (see Figure 2), which is used to remove deposits remaining on the outer surface 51a of the fixing belt 51 by rotation, thereby ensuring cleaning performance against toner and wax deposits adhering to the bottom of the roughness of the fixing belt 51. The following describes various embodiments of the fuser unit 14.
[0020] Figure 2 is a diagram illustrating the configuration of the fuser 14 according to the first embodiment. As shown in the figure, the fixer 14 according to the first embodiment includes the above-mentioned fixer belt module 50 equipped with a fixer belt 51 as an example of a fixer member, and the above-mentioned pressure roll 61 that contacts the outer surface of the fixer belt 51.
[0021] The anchoring belt module 50 includes the aforementioned anchoring belt 51 that moves circumferentially in the direction of arrow C, and a first tensioning roll 52 that tensions the anchoring belt 51 from the inside. The anchoring belt module 50 also includes a second tensioning roll 55, which is an example of a rotating member that tensions the anchoring belt 51 from the inside, located upstream of the first tensioning roll 52 in the direction of arrow C. Furthermore, the anchoring belt module 50 includes a pressing portion 53 located downstream of the first tensioning roll 52 in the direction of arrow C, which has a pad portion 53a for pressing the anchoring belt 51 against the pressure roll 61 to form a nip portion N.
[0022] In the fuser unit 14, a nip portion N is formed when a part of the outer surface 61a of the pressure roll 61 is pressed against the outer surface 51a of the fuser belt 51, which is in contact with the pressing portion 53, from the opposite side of the pressing portion 53. The nip portion N, where the outer surface 61a of the pressure roll 61 and the fuser belt 51 come into contact, is a passage portion through which the paper P, on which the toner image has been formed, passes while being pressurized and heated.
[0023] In this embodiment, the paper P that enters the nip section N has a toner image forming surface on which a toner image is formed. However, in this embodiment, the paper P enters the nip section N with the toner image forming surface facing upwards. As a result, in this embodiment, the toner image forming surface side of the paper P comes into contact with the fixing belt 51.
[0024] In this embodiment, the pressure roll 61 is rotationally driven by the motor 81, and the fixing belt 51 moves in a circular motion following the pressure roll 61. That is, the fixing belt 51 receives driving force from the rotating pressure roll 61 and moves in a circular motion (circular motion) in the direction of arrow C. The motor 81 is driven and controlled by the control unit 40.
[0025] The first tensioning roll 52 and the second tensioning roll 55 are rotatably supported, and the fixing belt 51 is wrapped around them at positions separated from each other, thereby supporting the fixing belt 51 so that it can move around. The pressing part 53 is positioned opposite the pressure roll 61, sandwiching the fixing belt 51, and presses the fixing belt 51 against the pressure roll 61 without rotating. The pressure roll 61 has an elastically deformable layer on its outer surface, and when the pressing part 53 contacts it via the fixing belt 51, the pressure roll 61 takes on a concave shape at the nip portion N. In this embodiment, the paper P is sandwiched from both sides by the pressure roll 61 and the pressing part 53, and pressure is applied to the paper P.
[0026] A heater 52a is provided inside the first tensioning roll 52. A heater 55a is provided inside the second tensioning roll 55. These heaters 52a and 55a are, for example, halogen heaters. The heat from heater 52a heats the first tensioning roll 52, and the heat from heater 55a heats the second tensioning roll 55. The heat from the first tensioning roll 52 and the second tensioning roll 55 then heats the fixing belt 51. In the example shown in Figure 2, the anchoring belt 51 is wrapped around the outer surface of the first tensioning roll 52 over a section of about one-quarter of its circumference, and the anchoring belt 51 is wrapped around the outer surface 55b of the second tensioning roll 55 over a section of more than half of its circumference. As a result, heat from the heaters 52a and 55a is applied to the anchoring belt 51.
[0027] The fixing belt module 50 is equipped with a liquid coating device 54 between the first tensioning roll 52 and the second tensioning roll 55 for applying oil to the inner surface of the fixing belt 51. The liquid coating device 54 comprises an oil-impregnating member 541 that contacts the inner surface of the fixing belt 51, a housing 542 that holds the oil-impregnating member, and a support member 543 that supports the portion of the oil-impregnating member, including its tip, from the side opposite to the fixing belt 51.
[0028] The oil-impregnated member 541 is made of a nonwoven fabric formed from heat-resistant fibers and impregnated with oil. For example, PTFE (polytetrafluoroethylene) is used as the heat-resistant fiber. The oil applied to the inner circumferential surface 51b of the fixing belt 51 by the oil-impregnated member 541 reduces the coefficient of friction between the pressing part 53 and the fixing belt 51, thereby suppressing wear of the fixing belt 51.
[0029] The fixing belt module 50 includes an upstream cleaning roll 71, which is an example of a removal member, as a configuration for cleaning the outer peripheral surface 51a of the fixing belt 51. The upstream cleaning roll 71 is a cleaning member for cleaning the outer surface 51a of the fixing belt 51, and more specifically, it removes any deposits and other substances adhering to the outer surface 51a of the fixing belt 51 that has passed through the nip section N.
[0030] The upstream cleaning roll 71 is positioned upstream of the second tension roll 55, with the fixing belt 51 sandwiched between it and the second tension roll 55. In other words, the upstream cleaning roll 71 is positioned so as to press the portion of the fixing belt 51 that is separated from the second tension roll 55 at the entrance of the second tension roll 55 against the second tension roll 55.
[0031] The upstream cleaning roll 71 according to the first embodiment has a surface formed of a nonwoven fabric, felt material, or porous material. Furthermore, the upstream cleaning roll 71 according to the first embodiment is a driven roll that rotates by contacting the fixing belt 51 which is moving in a circular motion.
[0032] To explain further, as shown in Figure 2, the fixing belt 51 that has passed through the nip section N is sandwiched between the upstream cleaning roll 71 and the second tensioning roll 55, causing it to deform into a so-called S-shape. That is, the fixing belt 51 deforms into a shape in which an inner circumferential protrusion 51c, which is an example of a second portion that is convex on the inner circumferential surface 51b side of the fixing belt 51 so as to follow the upstream cleaning roll 71, and an outer circumferential protrusion 51d, which is an example of a first portion that is convex on the outer circumferential surface 51a side of the fixing belt 51 so as to follow the second tensioning roll 55, are continuous. The inner circumferential protrusion 51c is a deformation caused by pressure from the upstream cleaning roll 71 at the entrance of the fixing belt 51 to the second tensioning roll 55. This S-shaped deformation creates a trajectory of the fixing belt 51 at the entrance to the second tensioning roll 55 due to the pressure exerted by the upstream cleaning roll 71.
[0033] Here, we compare the strain when the fixing belt 51 comes into contact with the adjacent second tension roll 55 and the upstream cleaning roll 71, forming an S-shape (hereinafter referred to as S-shaped contact), and when the fixing belt 51 comes into contact only with the second tension roll 55 and not with the upstream cleaning roll 71 (hereinafter referred to as simple contact).
[0034] Figure 3 is a graph showing the circumferential strain in simple contact and S-shaped contact. The vertical axis represents the strain (%) of the anchoring belt 51, and the horizontal axis represents the position (mm) in the direction of arrow C. In Figure 3, simple contact is shown with a solid line, and S-shaped contact is shown with a dashed line. The direction of arrow C here is shown in Figure 2. Strain is expressed as a ratio of elongation (or contraction).
[0035] As shown in Figure 3, the simple contact case, indicated by the solid line, is a configuration in which the fixing belt 51 is wrapped around the second tensioning roll 55 (see Figure 2), but the upstream cleaning roll 71 is not provided. In the case of simple contact, the graph is symmetrical with respect to position 0 mm, and there is no difference in strain when the distance increases to the left (upstream) from position 0 mm and when the distance increases to the right (downstream) from position 0 mm.
[0036] To explain further, the strain on the anchoring belt 51 is greater at the entrance of the second tensioning roll 55 (see Figure 2), and in the S-shaped contact shown by the dashed line, the upstream cleaning roll 71 is positioned at this entrance to form an S-shaped trajectory. In other words, the S-shaped contact shown by the dashed line is the case where the upstream cleaning roll 71 is positioned on the upstream side (see Figure 2). According to the graph, the strain sign is negative to the left of position 0 mm, and the strain sign is positive to the right of position 0 mm. This indicates that the anchoring belt 51 is contracting to the left of position 0 mm and stretching to the right of position 0 mm. From position 0mm to the left, the fixing belt 51 shrinks due to the action of the upstream cleaning roll 71, and from position 0mm to the right, where it is not affected by the action of the upstream cleaning roll 71, the strain becomes positive, approaching the case of simple contact (solid line).
[0037] To explain further, at a position to the left of 0 mm, at the entrance of the second tension roll 55 (see Figure 2), there is a region where the negative strain value is large, after which the negative strain value decreases and becomes positive. This strain fluctuation of the anchoring belt 51 causes a rotational speed difference between the anchoring belt 51 and the upstream cleaning roll 71.
[0038] Figure 4 illustrates the relative movement between an upstream cleaning roll 71, which is an example of a removal member, and a fixing belt 51, which is an example of a fixing member. As shown in the figure, deposits D are present on the outer surface 51a of the fixing belt 51. These deposits D are removed by the upstream cleaning roll 71, which operates at a speed different from that of the fixing belt 51. In other words, the upstream cleaning roll 71 removes the deposits D adhering to the outer surface 51a of the fixing belt 51 using the difference in rotational speed relative to the fixing belt 51.
[0039] As described above, the upstream cleaning roll 71 has a surface formed of nonwoven fabric or felt material. Therefore, toner and liquid wax can be removed as adhering substances D by the upstream cleaning roll 71, and the occurrence of offset images caused by the adhering substances D being transferred to the next conveyed paper P is suppressed.
[0040] Figure 5 is a graph showing the amount of wax on the fixing belt 51 before and after cleaning by the upstream cleaning roll 71 in simple contact and S-shaped contact conditions. The vertical axis represents the wax area percentage (%), and the horizontal axis shows the amount before (before the roll) and after (after the roll) the upstream cleaning roll 71 for both simple contact and S-shaped contact. As is clear from the graph in Figure 5, in the case of simple contact, the wax area ratio is 15.6% before the roll, and decreases to 12.9% after the roll is cleaned by the upstream cleaning roll 71. In contrast, in the case of S-shaped contact, the wax area ratio is 15.9% before the roll, and decreases significantly to 8.1% after the roll is cleaned by the upstream cleaning roll 71.
[0041] Thus, in the case of S-shaped contact, cleaning performance is improved compared to the case of simple contact. The wax area ratio referred to here is the amount of wax adhering per unit area on the outer surface 15a of the fixing belt 51, expressed as an area ratio. The fact that the values are not identical (15.6% for simple contact and 15.9% for S-shaped contact) is due to measurement errors.
[0042] Figure 6 is a diagram illustrating the configuration of the fuser 14 according to the second embodiment. Since the second embodiment has parts in common with the configuration of the first embodiment described above, the same reference numerals are used for the common parts, and their descriptions may be omitted. In the second embodiment shown in Figure 6, the configuration for cleaning the outer circumferential surface 51a of the fixing belt 15 includes an upstream cleaning roll 71 and a cleaning mechanism 72.
[0043] The cleaning mechanism 72 includes a holding unit 722 that holds and feeds out unused cleaning webs 721 in a wound-up manner, and a supply unit 723 that winds up the cleaning webs 721 and supplies them from the holding unit 722 to the outer surface of the upstream cleaning roll 71. The cleaning mechanism 72 also includes a pressing member 724 that presses the cleaning webs 721 against the surface of the upstream cleaning roll 71.
[0044] In the second embodiment, the upstream cleaning roll 71 is a metal roll, and any deposits on the upstream cleaning roll 71 removed from the fixing belt 51 are removed from the upstream cleaning roll 71 by the cleaning web 721. The cleaning web 721 cleans the upstream cleaning roll 71, which is a metal roll. Furthermore, the upstream cleaning roll 71 in the second embodiment is a driven roll, just like in the first embodiment.
[0045] Figure 7 is a diagram illustrating the configuration of the fuser 14 according to the third embodiment. Since the third embodiment has parts in common with the configuration of the second embodiment described above, the same reference numerals are used for the common parts, and their descriptions may be omitted. In the third embodiment shown in Figure 7, the configuration for cleaning the outer surface 51a of the fixing belt 51 includes an upstream cleaning roll 71 and a cleaning mechanism 72, which are examples of removal members, as well as a downstream cleaning roll 73, which is another example of a removal member, provided at the exit point of the fixing belt 51 from the second tensioning roll 55. The downstream cleaning roll 73 is positioned downstream of the second tensioning roll 55 and removes any deposits that could not be removed by the upstream cleaning roll 71.
[0046] To further explain, the downstream cleaning roll 73 is positioned so that the portion of the fixing belt 51 that is separated from the second tension roll 55 at the exit of the second tension roll 55 is pressed against the second tension roll 55. With this arrangement, the S-shaped contact at the entrance of the second tension roll 55, as described for the upstream cleaning roll 71, is also formed at the exit of the second tension roll 55 by the downstream cleaning roll 73. This improves the cleaning performance by the downstream cleaning roll 73. Furthermore, the convex portion 51c on the inner circumferential surface at the S-shaped contact at the exit of the second tensioning roll 55 is a deformation caused by pressing by the downstream cleaning roll 73.
[0047] In the third embodiment, the upstream cleaning roll 71 at the inlet is a metal roll, as in the second embodiment, and the downstream cleaning roll 73 added at the outlet has a removal surface formed by a nonwoven fabric, felt material, or porous material. That is, the metal upstream cleaning roll 71 mainly removes powdered toner, and the downstream cleaning roll 73 with a surface such as nonwoven fabric removes residual liquid wax. The third embodiment is useful in the case of color printing with a large amount of toner. In addition, the outlet of the fixing belt 51 is wider than the inlet of the second tensioning roll 55. Temperature Because the temperature rises, residual wax is removed more efficiently. Furthermore, the upstream cleaning roll 71 and the downstream cleaning roll 73 in the third embodiment are driven rolls.
[0048] Figure 8 is a block diagram illustrating the fourth embodiment, Figure 9 is a block diagram illustrating another embodiment, Figure 9(a) is a diagram illustrating the fifth embodiment, and Figure 9(b) is a diagram illustrating the sixth embodiment. In these embodiments, the rotational speed difference between the fixing belt 51 and the upstream cleaning roll 71 is achieved by the configuration of the drive source or drive transmission system. The following explains further.
[0049] In the fourth embodiment shown in Figure 8, the fixing belt module 50 includes the motor 81 described above, which is an example of a drive source for driving the fixing member, as well as a cleaning roll motor 82, which is another example of a drive source. That is, as shown in Figure 8, the fixing belt module 50 includes two motors: the motor 81 described above that rotates the pressure roll 61, and the cleaning roll motor 82 that rotates the upstream cleaning roll 71. Both the motor 81 and the cleaning roll motor 82 are driven and controlled by the control unit 40.
[0050] In the fixing belt module 50 according to the fourth embodiment, the control unit 40 controls the motor 81 and the cleaning roll motor 82 so that a rotational speed difference is generated between the fixing belt 51 and the upstream cleaning roll 71.
[0051] In the fifth embodiment shown in Figure 9(a), the fixing belt module 50 includes the motor 81 described above, a drive force branching section 83 that branches the driving force of the motor 81, and a reduction device 84 that reduces one of the driving forces branched by the drive force branching section 83. The reduced driving force, then decelerated by the reduction gear 84, is transmitted to the upstream cleaning roll 71. The other driving force, branched off by the driving force branching section 83, is transmitted to the fixing belt 51 via the pressure roll 61.
[0052] In the fixing belt module 50 according to the fifth embodiment, the upstream cleaning roll 71 is driven by a driving force that is branched and reduced in the transmission system from the motor 81 described above, while the pressure roll 61 and fixing belt 51 are driven by a driving force that is not reduced. As a result, the rotational speed of the upstream cleaning roll 71 is lower than that of the fixing belt 51, and a difference in rotational speed between the two is achieved. In this configuration, the driving force of a single motor 81 is transmitted, creating a rotational speed difference between the fixing belt 51 and the upstream cleaning roll 71.
[0053] In the sixth embodiment shown in Figure 9(b), the motor 81, drive force branching unit 83, and reduction gear 84 are included, just as in the fifth embodiment. However, the sixth embodiment differs from the fifth embodiment in that the pressure roll 61 and fixing belt 51 are driven by the reduced drive force, while the upstream cleaning roll 71 is driven by the unreduced drive force. As a result, the rotational speed of the fixing belt 51 is lower than that of the upstream cleaning roll 71, creating a difference in their rotational speeds. Thus, in the sixth embodiment as well, the configuration transmits the driving force of a single motor 81, thereby creating a rotational speed difference between the fixing belt 51 and the upstream cleaning roll 71.
[0054] Furthermore, the fourth, fifth, and sixth embodiments described above may also be applied to the case of S-shaped contact described above (see Figures 2, 6, or 7), or they may be applied to the case where simple contact is achieved by positioning the upstream cleaning roll 71 at a relative position to the second tension roll 55 that does not result in S-shaped contact. [Explanation of Symbols]
[0055] 1…Image forming apparatus, 10…Image forming unit, 14…Fuser, 51…Fuser belt, 51a…Outer surface, 51b…Inner surface, 51c…Inner surface side protrusion, 51d…Outer surface side protrusion, 55…Second tensioning roll, 55b…Outer surface, 71…Upstream cleaning roll, 73…Downstream cleaning roll, 81…Motor, 82…Motor for cleaning roll, P…Paper
Claims
1. A fixing member having an outer circumferential surface and an inner circumferential surface, rotatably mounted, contacts the surface on which the image is formed in a recording material, and fixes the image to the recording material, A rotating member that is rotatably mounted and has a contact surface on its outer circumference that contacts the inner circumferential surface of the fixing member, A removal member is provided that is in contact with the outer circumferential surface of the fixing member, is rotatably mounted, and removes deposits adhering to the outer circumferential surface using the difference in rotational speed relative to the fixing member, Equipped with, The rotating member has a heating source, The removal member is provided at the outlet portion of the rotating member, in a position opposite to the rotating member, with the fixing member sandwiched between them, and presses the portion of the fixing member that is separated from the rotating member against the rotating member, in a fixing device.
2. A fixing member having an outer peripheral surface and an inner peripheral surface, rotatably mounted, in contact with the surface on which an image is formed in a recording material, and fixing the image to the recording material, A rotating member that is rotatably mounted and has a contact surface on its outer circumference that contacts the inner circumferential surface of the fixing member, The fixing member comprises a removal member that is positioned in contact with the outer circumferential surface of the fixing member, is rotatably mounted, and removes deposits adhering to the outer circumferential surface using the difference in rotational speed relative to the fixing member, The rotating member has a heating source, The difference in rotational speed between the removal member and the fixing member is due to the deformation of the fixing member into a shape in which a first portion that is convex on the outer circumferential surface side and a second portion that is convex on the inner circumferential surface side are continuous. The second part is the deformation at the entrance portion of the fixing member to the rotating member due to the pressing by the removal member, A separate removal member is positioned at the exit portion of the fixing member relative to the rotating member, thereby causing the portion of the fixing member that is separated from the rotating member to be pressed against the rotating member. The second part is the deformation of the fixing member at the exit portion relative to the rotating member due to pressing by the removal member. Fixing device.
3. The fixing device according to claim 2, characterized in that the difference in rotational speed of the removal member with respect to the fixing member is obtained by driving the removal member to rotate at a different speed from that of the fixing member.
4. The fixing device according to claim 3, characterized in that the drive is performed by a drive source separate from the drive source that drives the fixing member.
5. The aforementioned drive is performed by a driving force that is branched and reduced in the transmission system from the drive source that drives the fixing member. The fixing device according to feature 3.
6. The removal member at the entrance is a metal roll. The fixing device according to claim 2, characterized in that the removal surface of the other removal member at the outlet portion is a nonwoven fabric or felt.
7. An image forming unit that forms an image on a recording material, A fixing member having an outer circumferential surface and an inner circumferential surface, rotatably mounted, contacts the surface on which the image is formed in a recording material, and fixes the image to the recording material, A rotating member that is rotatably mounted and has a contact surface on its outer circumference that contacts the inner circumferential surface of the fixing member, The fixing member comprises a removal member that is positioned in contact with the outer circumferential surface of the fixing member, is rotatably mounted, and removes deposits adhering to the outer circumferential surface using the difference in rotational speed relative to the fixing member, The rotating member has a heating source, The removal member is provided at the exit portion of the rotating member, with the fixing member in between, and is positioned opposite the rotating member, pressing the portion of the fixing member that is separated from the rotating member against the rotating member. Image forming apparatus.
8. An image forming unit that forms an image on a recording material, A fixing member having an outer circumferential surface and an inner circumferential surface, rotatably mounted, contacts the surface on which the image is formed of the recording material by the image forming unit, and fixes the image to the recording material; A rotating member that is rotatably mounted and has a contact surface on its outer circumference that contacts the inner circumferential surface of the fixing member, A removal member is provided that is in contact with the outer circumferential surface of the fixing member, is rotatably mounted, and removes deposits adhering to the outer circumferential surface using the difference in rotational speed relative to the fixing member, Equipped with, The rotating member has a heating source, The difference in rotational speed between the removal member and the fixing member is due to the deformation of the fixing member into a shape in which a first portion that is convex on the outer circumferential surface side and a second portion that is convex on the inner circumferential surface side are continuous. The second part is the deformation at the entrance portion of the fixing member to the rotating member due to the pressing by the removal member, A removal member, separate from the removal member, is positioned at the exit portion of the fixing member relative to the rotating member, thereby pressing the portion of the fixing member that is separated from the rotating member against the rotating member, and the second portion is the deformation of the fixing member at the exit portion relative to the rotating member due to the pressing by the removal member. Image forming apparatus.