Fixing device and image forming apparatus

Abstract

To cancel accumulation of powder on the downstream side of a fixing area.SOLUTION: A fixing device (F) comprises: fixing means (Fh) that fixes an image of a medium (S); guiding means (2) that is arranged on the downstream side of the fixing means (Fh) with respect to a conveyance direction of the medium (S) and guides the medium (S); and cleaning entry means (6) that is provided in correspondence with a gap (7) between the fixing means (Fh) and the guiding means (2) and causes cleaning means (21) to enter the gap (7).SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a fixing device and an image forming apparatus having the fixing device. [Background technology]

[0002] With regard to a fixing device that fixes an image in an image recording device, the techniques described in Patent Documents 1 to 3 listed below are conventionally known.

[0003] Patent Documents 1 and 2 describe a technique for cleaning a fixing belt (171) or a heat roll (172) of a fixing unit by using a first cleaning roll (210, 310). In Patent Document 1, the first cleaning roll (210, 310) is formed in a roller shape extending along the axial direction of the fixing belt (171) or the heat roll (172).

[0004] Patent Document 3 describes a configuration in which unfixed toner adhering to a fixing belt (14) is wiped off by an oil roller (13d), and the unfixed toner wiped off by the oil roller (13d) is removed by a cleaning roller (13e). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2014-59385 A ("0039" to "0050", Figs. 7 to 10) [Patent Document 2] JP 2014-59391 A ("0042" to "0054", Figs. 7 to 10) [Patent Document 3] JP 2013-83969 A ("0022" to "0027", Figure 4) Summary of the Invention [Problem to be solved by the invention]

[0006] SUMMARY OF THE PRESENT EMBODIMENT An object of the present invention is to eliminate powder buildup downstream of the fusing area. [Means for solving the problem]

[0007] In order to solve the above technical problem, the fixing device of the invention described in claim 1 comprises: a fixing means for fixing the image on the medium; a guide means arranged downstream of the fixing means in a medium transport direction to guide the medium; a cleaning entry means provided in correspondence with a gap between the fixing means and the guiding means, for allowing a cleaning means to enter the gap; The present invention is characterized by comprising:

[0008] The invention described in claim 2 is the fixing device described in claim 1, a conveying means arranged upstream of the fixing means in a conveying direction of the medium and conveying the medium, the conveying means being arranged at a predetermined position in the width direction of the medium, the cleaning entry means being provided at a position corresponding to a position of the conveying means in the width direction; The present invention is characterized by comprising:

[0009] The invention described in claim 3 is the fixing device described in claim 2, the conveying means being constituted by a paper feeding means through which the medium is fed; The present invention is characterized by comprising:

[0010] The invention described in claim 4 is the fixing device described in claim 1, the cleaning access means being an opening formed in a housing of the fixing means; The present invention is characterized by comprising:

[0011] The invention described in claim 5 is the fixing device described in claim 4, the housing in which wiring to the fixing means is arranged; a protection means for covering and protecting the outside of the wiring, the protection means having a blocking means for blocking the opening; The present invention is characterized by comprising:

[0012] In order to solve the above technical problem, the image forming apparatus according to the invention described in claim 6 comprises: An image holding means; a transfer means for transferring the image held on the image holding means to a medium; A fixing device according to any one of claims 1 to 5, which fixes an image transferred onto a medium; The present invention is characterized by comprising: Effect of the Invention

[0013] According to the invention as recited in claims 1 and 6, accumulation of powder on the downstream side of the fixing area can be eliminated. According to the invention recited in claim 2, it is possible to eliminate accumulation of powder at a position corresponding to the conveying means where powder is likely to accumulate locally. According to the invention as recited in claim 3, it is possible to eliminate accumulation of powder at a position corresponding to the paper feed means where powder is likely to accumulate locally. According to the invention as recited in claim 4, the powder can be removed through the opening in the housing. According to the invention as set forth in claim 5, the fixing means can be protected by the blocking means. [Brief description of the drawings]

[0014] [Figure 1] FIG. 1 is an overall explanatory diagram of an image forming apparatus according to a first embodiment. [Diagram 2] FIG. 2 is a diagram illustrating a main part of the image recording unit of the first embodiment. [Diagram 3] FIG. 3 is an enlarged view of the fixing device of the first embodiment. [Figure 4] FIG. 4 is a view seen from the direction of arrow IV in FIG. [Diagram 5] FIG. 5 is an explanatory diagram of a state in which the protection means is removed from FIG. [Figure 6] FIG. 6 is an explanatory diagram of the heating roller during cleaning. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] Next, examples of the present invention will be described with reference to the drawings. However, the present invention is not limited to the following examples. In order to make the following explanation easier to understand, in the drawings, the front-to-back direction is the X-axis direction, the left-to-right direction is the Y-axis direction, and the up-down direction is the Z-axis direction, and the directions or sides indicated by arrows X, -X, Y, -Y, Z, and -Z are respectively the front, rear, right, left, upper, and lower, or the front side, rear side, right side, left side, upper side, and lower side. In addition, in the figures, a "·" inside a "○" means an arrow going from the back to the front of the page, and an "×" inside a "○" means an arrow going from the front to the back of the page. In the following description using the drawings, illustrations of components other than those necessary for the description are omitted as appropriate to facilitate understanding. EXAMPLES

[0016] FIG. 1 is an overall explanatory diagram of an image forming apparatus according to a first embodiment. 1, a copier U as an example of an image forming apparatus according to the first embodiment of the present invention has a printer U1 as an example of an image recording means and an example of an image recording device. A scanner U2 as an example of a reading means and an example of an image reading device is supported above the printer U1. An auto feeder U3 as an example of a document conveying device is supported above the scanner U2.

[0017] An original tray TG1, which is an example of a medium storage means, is disposed above the auto feeder U3. A plurality of originals Gi to be copied can be stacked and stored in the original tray TG1. Below the original tray TG1, an original discharge tray, which is an example of an original discharge section, is disposed. Between the document tray TG1 and the document discharge tray TG2, document transport rollers U3b are disposed along the document transport path U3a.

[0018] A platen glass PG, which is an example of a transparent document table, is disposed on the upper surface of the scanner unit U2. In the scanner unit U2 of the first embodiment, a reading unit U2a, which is an example of a reading unit, is disposed below the platen glass PG. The reading unit U2a of the first embodiment is supported along the lower surface of the platen glass PG so as to be movable in the left-right direction, which is an example of a sub-scanning direction. The reading unit U2a is electrically connected to the image processing unit GS.

[0019] FIG. 2 is a diagram illustrating a main part of the image recording unit of the first embodiment. The image processing unit GS is electrically connected to a writing circuit DL of the printer unit U1. The writing circuit DL is electrically connected to exposure devices LHy, LHm, LHc, and LHk, which are an example of a latent image forming means. The exposure devices LHy to LHk of the first embodiment are configured, for example, with an LED head in which a plurality of LEDs are arranged in the main scanning direction. The exposure devices LHy to LHk are configured to be able to output writing light corresponding to each of the colors Y, M, C, and K in response to a signal input from a writing circuit DL. The write circuit DL and the power supply circuit E have their write timing and power supply timing controlled in response to control signals from a control unit C, which is an example of a control means. In Fig. 1, photoconductors PRy, PRm, PRc, and PRk as an example of an image holding means are disposed above the exposure devices LHy to LHk. In Fig. 1 and Fig. 2, writing areas Q1y, Q1m, Q1c, and Q1k are formed by areas on the photoconductors PRy to PRk where the writing light is irradiated.

[0020] Charging rollers CRy, CRm, CRc, and CRk as an example of a charging means are disposed upstream of the writing areas Q1y to Q1k in the rotation direction of each of the photoconductors PRy to PRk. The charging rollers CRy to CRk in the first embodiment are supported in contact with the photoconductors PRy to PRk so as to be rotatable by the photoconductors PRy to PRk. Developing devices Gy, Gm, Gc, and Gk, which are an example of developing means, are disposed downstream of the writing areas Q1y-Q1k in the rotation direction of the photoconductors PRy-PRk. The developing areas Q2y, Q2m, Q2c, and Q2k are formed by the areas where the photoconductors PRy-PRk and the developing devices Gy-Gk face each other.

[0021] Primary transfer rollers T1y, T1m, T1c, and T1k, which are an example of a primary transfer means, are disposed downstream of the developing devices Gy-Gk in the rotation direction of the photoconductors PRy-PRk. Primary transfer areas Q3y, Q3m, Q3c, and Q3k are formed by areas where the photoconductors PRy-PRk and the primary transfer rollers T1y-T1k face each other. Photoconductor cleaners CLy, CLm, CLc, and CLk, which are an example of a cleaning means, are disposed downstream of the primary transfer rollers T1y to T1k with respect to the rotation direction of the photoconductors PRy to PRk. Dischargers Jy, Jm, Jc, and Jk, which are an example of a discharge means and an example of a discharge device, are disposed downstream of the photoconductor cleaners CLy-CLk with respect to the rotation direction of the photoconductors PRy-PRk.

[0022] The Y-color photoconductor PRy, charging roller CRy, exposure device LHy, developing device Gy, primary transfer roller T1y, photoconductor cleaner CLy, and static eliminator Jy constitute a Y-color image forming unit Uy as an example of a Y-color visible image forming means in Example 1 for forming a Y-color toner image. Similarly, the photoconductors PRm, PRc, and PRk, charging rollers CRm, CRc, and CRk, exposure devices LHm, LHc, and LHk, developing devices Gm, Gc, and Gk, primary transfer rollers T1m, T1c, and T1k, photoconductor cleaners CLm, CLc, and CLk, and static eliminators Jm, Jc, and Jk form a Y-color toner image. The image forming units Um, Uc, and Uk for the M, C, and K colors are configured as above.

[0023] A belt module BM, which is an example of an intermediate transfer device, is disposed above the photoconductors PRy to PRk. The belt module BM is an example of an image holding means, and has an intermediate transfer belt B, which is an example of an intermediate transfer means. The intermediate transfer belt B is made of an endless belt-like member. The intermediate transfer belt B in the first embodiment is rotatably supported by a tension roller Rt as an example of a tensioning means, a walking roller Rw as an example of a deviation correcting means, an idler roller Rf as an example of a driven means, a backup roller T2a as an example of an opposing means in the secondary transfer region, primary transfer rollers T1y to T1k, and a drive roller Rd as an example of a drive member. In the first embodiment, when the drive force is transmitted to the drive roller Rd, the intermediate transfer belt B rotates.

[0024] A secondary transfer roller T2b as an example of a secondary transfer means is disposed at a position facing the backup roller T2a across the intermediate transfer belt B. The backup roller T2a and the secondary transfer roller T2b constitute a secondary transfer unit T2 of the first embodiment as an example of a transfer device. A secondary transfer area Q4 is constituted by an area where the secondary transfer roller T2b and the intermediate transfer belt B contact each other. A belt cleaner CLb is disposed downstream of the secondary transfer area Q4 in the rotation direction of the intermediate transfer belt B, as an example of a cleaning device for the intermediate transfer body. The primary transfer rollers T1y-T1k, the intermediate transfer belt B, the secondary transfer unit T2, etc., constitute a transfer device T1+T2+B of the first embodiment as an example of a transfer means. The image forming units Uy-Uk and the transfer device T1+T2+B constitute an image recording unit Uy-Uk+T1+T2+B of the first embodiment.

[0025] In Fig. 1, four pairs of left and right guide rails GR as an example of a guide means are provided below the imaging units Uy to Uk. Each guide rail GR supports paper feed trays TR1, TR2, TR3, and TR4 as an example of a medium storage means so that they can be moved in and out in the front-rear direction. Recording paper S as an example of a medium is stored in the paper feed trays TR1 to TR4. A pickup roller Rp, which is an example of a take-out means, is disposed at the upper left of the paper feed trays TR1 to TR4. A separation roller Rs, which is an example of a separation means, is disposed downstream of the pickup roller Rp in the transport direction of the recording paper S. The separation roller Rs has a feed roller Rs1, which is an example of a transport means, and a retard roller Rs2, which is an example of a stopping means. A paper feed path SH1, which extends upward and is an example of a medium transport path, is formed downstream of the separation roller Rs in the transport direction of the recording paper S. A plurality of transport rollers Ra, which are an example of a transport means, are disposed on the paper feed path SH1.

[0026] A manual feed tray TR0, which is an example of a medium storage means, is disposed in the lower left portion of the copier U. A pickup roller Rp0 is disposed in the upper right portion of the manual feed tray TR0, and a manual feed path SH0 extends from the manual feed tray TR0. The manual feed path SH0 merges with the feed path SH1. In the sheet feed path SH1, a registration roller Rr as an example of a conveyance timing adjustment unit is disposed upstream of the secondary transfer area Q4. A conveyance path SH2 extends from the registration roller Rr toward the secondary transfer area Q4.

[0027] A fixing device F as an example of a fixing means is disposed downstream of the secondary transfer area Q4 in the conveying direction of the recording paper S. The fixing device F has a heating roller Fh as an example of a fixing member for heating, and a pressure roller Fp as an example of a fixing member for pressurizing. A fixing area Q5 is formed by a contact area between the heating roller Fh and the pressure roller Fp. A heater as an example of a heat source is housed inside the heating roller Fh. The pressure roller Fp is pressed against the heating roller Fh with a predetermined fixing pressure. A lower paper discharge tray TRh, which is an example of a medium discharge section, is formed on the upper surface of the printer unit U1. In the first embodiment, a finisher U4, which is an example of a post-processing device, is installed on the lower paper discharge tray TRh. Above the fixing device F, a paper discharge path, which is an example of a transport path, is installed. The path SH3 extends toward the lower discharge tray TRh. Discharge rollers Rh, which are an example of a medium transport means, are disposed at the downstream end of the discharge path SH3.

[0028] An upper discharge tray TRh2 as an example of a medium discharge section is disposed above the lower discharge tray TRh. An upper conveying path SH4 is formed above the fixing device F, branching off from the discharge path SH3 and extending toward the upper discharge tray TRh2. A reversible roller Rb, which is an example of a medium transport means, is disposed on the upper transport path SH4. A reversible path SH6, which is an example of a medium transport path, branches off to the lower left from the upper transport path SH4 above the branching position of the paper discharge path SH3 and the upper transport path SH4.

[0029] A gate GT1, which is an example of a switching means, is disposed across a branching portion between the discharge path SH3 and the upper transport path SH4 and a branching portion between the upper transport path SH4 and the reverse path SH6. The gate GT1 guides the recording paper S from the fixing device F toward the lower discharge tray TRh, and is supported switchably between a first guide position (second position) where the recording paper S is guided from the upper transport path SH4 to the reverse path SH6, and a second guide position (first position) where the recording paper S from the fixing device F is guided to the upper transport path SH4. A plurality of transport rollers Ra, which are an example of a medium transport means, are disposed on the reversing path SH6. The downstream end of the reversing path SH6 joins the paper feed path SH1 on the upstream side of the registration rollers Rr.

[0030] (Explanation of Image Forming Operation) In the copying machine U of the first embodiment having the above configuration, when an operator places an original Gi on the platen glass PG by hand to perform copying, the reading unit U2a moves from the initial position in the left-right direction, and the original Gi on the platen glass PG is exposed to light and scanned. When the automatic feeder U3 is used to automatically transport the original Gi to perform copying, the multiple originals Gi accommodated in the original tray TG1 are transported sequentially to the original reading position on the platen glass PG, pass through it, and are discharged to the original discharge tray TG2. Each original Gi that passes sequentially through the reading position on the platen glass PG is exposed to light and scanned by the reading unit U2a. The reflected light from the original Gi is received by the reading unit U2a. The reading unit U2a converts the received reflected light from the original Gi into an electrical signal. When double-sided reading of the original Gi is performed, the original Gi is also read by the reading sensor.

[0031] The image processing unit GS receives the electrical signals output from the reading unit U2a. The image processing unit GS converts the electrical signals of the R, G, and B color image read by the reading unit U2a into image information of yellow (Y), magenta (M), cyan (C), and black (K) for forming a latent image. The image processing unit GS outputs the converted image information to the writing circuit DL of the printer unit U1. Note that when the image is a single-color image, that is, a monochrome image, the image processing unit GS outputs image information of only black (K) to the writing circuit DL. The writing circuit DL outputs a control signal corresponding to the input image information to the exposure devices LHy to LHk. The exposure devices LHy to LHk output writing light corresponding to the control signal.

[0032] When image formation starts, each of the photoconductors PRy-PRk is rotated. A charging voltage is applied to the charging rollers CRy-CRk from a power supply circuit E. Thus, the surfaces of the photoconductors PRy-PRk are charged by the charging rollers CRy-CRk. An electrostatic latent image is formed on the surface of the charged photoconductors PRy-PRk by the exposure devices LHy-LHk in the writing areas Q1y-Q1k. The electrostatic latent images on the photoconductors PRy-PRk are developed into toner images, which are an example of visible images, by the developing devices Gy-Gk in the developing areas Q2y-Q2k.

[0033] The developed toner image is conveyed to the primary transfer regions Q3y to Q3k that contact the intermediate transfer belt B, which is an example of an intermediate transfer body. A primary transfer voltage of the opposite polarity to the charge polarity of the toner is applied to the primary transfer rollers T1y-T1k from a power supply circuit E. Therefore, the toner images on the photoconductors PRy-PRk are transferred onto the intermediate transfer belt B by the primary transfer rollers T1y-T1k. In the case of a multi-color toner image, the toner image transferred onto the intermediate transfer belt B in the upstream primary transfer area is transferred onto the intermediate transfer belt B in a superimposed manner. After the primary transfer, residues and deposits on the photoconductors PRy-PRk are cleaned by the photoconductor cleaners CLy-CLk. The surfaces of the photoconductors PRy-PRk after cleaning are neutralized by the static eliminators Jy-Jk. The surfaces of the photoconductors PRy-PRk after static elimination are recharged by the charging rollers CRy-CRk. The single-color or multi-color toner images transferred onto the intermediate transfer belt B by the primary transfer rollers T1y to T1k in the primary transfer areas Q3y to Q3k are transported to the secondary transfer area Q4.

[0034] The recording paper S on which an image is recorded is picked up by the pickup roller Rp of the paper feed tray TR1 to TR4 being used. When multiple sheets of recording paper S are picked up by the pickup roller Rp and stacked, they are separated one by one by the separation roller Rs. That is, the topmost recording paper S is transported downstream by the feed roller Rs1, and the stacked recording paper S is stopped by the retard roller Rs2 and separated one by one. The recording paper S separated by the separation roller Rs is transported along the paper feed path SH1 by the transport roller Ra. The recording paper S transported along the paper feed path SH1 is sent to the registration roller Rr. The recording paper S loaded on the manual feed tray TR0 is also sent to the paper feed path SH1 by the pickup roller Rp0 via the manual feed path SH0. The registration roller Rr transports the recording paper S to the secondary transfer area Q4 in time with the toner image formed on the intermediate transfer belt B being transported to the secondary transfer area Q4. A secondary transfer voltage of a polarity opposite to the charge polarity of the toner is applied to the secondary transfer roller T2b by the power supply circuit E. Therefore, the toner image on the intermediate transfer belt B is transferred from the intermediate transfer belt B to the recording paper S.

[0035] After the secondary transfer, the intermediate transfer belt B has any adhering matter or the like on its surface cleaned by a belt cleaner CLb. The recording paper S onto which the toner image has been secondarily transferred is heated and fixed when passing through a fixing area Q5. If post-processing is performed on the recording paper S with the image fixed thereon, the recording paper S is transported to a finisher U4, which is an example of a post-processing device installed in the lower paper output tray TRh. If post-processing is not performed on the recording paper S, the recording paper S is transported to the upper paper output tray TRh2. When the recording paper S is transported to the lower paper output tray TRh, the gate GT1 moves to the first guide position. Therefore, the recording paper S sent out from the fixing device F is transported along the paper output path SH3. The recording paper S transported along the paper output path SH3 is transported by the paper output rollers Rh toward the finisher U4 and the lower paper output tray TRh. The finisher U4 performs a binding process, which is an example of post-processing, on the recording paper S, and then discharges the recording paper S onto a lower paper discharge tray TRh.

[0036] When the recording paper S is discharged onto the upper discharge tray TRh2, the gate GT1 moves to the second guiding position, and the recording paper S is discharged onto the upper discharge tray TRh2. When the recording paper S is printed on both sides, the gate GT1 moves to the second guide position. Then, when the trailing edge of the recording paper S passes through the gate GT1, the gate GT1 moves to the first guide position and the reversing roller Rb rotates in the reverse direction. Therefore, the recording paper S is guided by the gate GT1 and sent to the reversing path SH6. The recording paper S conveyed through the reversing path SH6 is sent to the registration roller Rr in an inverted state.

[0037] (Description of Fixing Device) FIG. 3 is an enlarged view of the fixing device of the first embodiment. FIG. 4 is a view seen from the direction of arrow IV in FIG. FIG. 5 is an explanatory diagram of a state in which the protection means is removed from FIG. 3 to 5, the fixing device F of the first embodiment has a housing 1 as an example of a case. The housing 1 has a heating housing portion 1a surrounding the heating roller Fh, and a pressure housing portion 1b surrounding the pressure roller Fp. A downstream sheet guide 2, an example of a guiding means, is supported in the heating housing portion 1a at a position downstream of the heating roller Fh in the paper transport direction. The downstream sheet guide 2 contacts and guides the recording paper S that has passed through the fixing area Q5. The downstream sheet guide 2 is disposed with a leading end 2a in close proximity to the outer surface of the heating roller Fh. Therefore, the downstream sheet guide 2 in the first embodiment also functions as a peeling means that peels the recording paper S from the heating roller Fh and prevents the recording paper S from sticking to or getting wrapped around the heating roller Fh.

[0038] The heated housing part 1a is formed with a cleaning hole 6 as an example of a cleaning entry means. The cleaning hole 6 in the first embodiment is formed at a position corresponding to a gap 7 between the outer surface of the heated roller Fh and the heated housing part 1a. More specifically, the cleaning hole 6 is formed downstream of the rotation center 8 of the heated roller Fh and corresponding to the gap 7 downstream of a vertex 9 on the downstream side of the outer periphery of the heated roller Fh. In FIG. 5, in the axial direction (longitudinal direction) of the heating roller Fh, i.e., in the width direction of the recording paper S, the cleaning hole 6 is an example of a conveying means and is formed at a position corresponding to the position of the feed roller Rs1, which is an example of a paper feeding means.

[0039] 4 and 5, in the fixing device F of the first embodiment, a temperature sensor (not shown) is provided to detect the temperature of the surface of the heating roller Fh. Therefore, a harness 11 is arranged as an example of wiring for supplying power to the temperature sensor and transmitting and receiving signals. A harness cover 12 as an example of a protective member is arranged on the outside of the harness 11. The harness cover 12 is arranged in a manner that covers the harness 11. Therefore, the harness cover 12 protects the harness 11. In the harness cover 12 of the first embodiment, a cleaning protection portion 12a as an example of a blocking means is formed at a position corresponding to the cleaning hole 6. Therefore, the cleaning hole 6 is blocked from the outside by the cleaning protection portion 12a. Therefore, compared to a case where the cleaning hole 6 is not blocked, the outer surface of the heating roller Fh is prevented from being exposed to the outside. Therefore, the cleaning protection portion 12a protects the heating roller Fh. The harness cover 12 is fixed to the heating housing portion 1a with screws. The harness cover 12 can be removed by loosening the screws when performing maintenance work such as inspection or replacement of the harness 11 or when cleaning through the cleaning hole 6.

[0040] FIG. 6 is an explanatory diagram of the heating roller during cleaning. In FIG. 6, a cleaning rod 21, which is an example of a cleaning means, can be inserted into the cleaning hole 6 to perform cleaning. The cleaning rod 21 is configured as a flat rod extending in the longitudinal direction. The cleaning rod 21 can be configured to be flexible, and is preferably configured to be elastically deformable. A felt 22, which is an example of a cleaning means body, is disposed at the tip of the cleaning rod 21. The felt 22 is configured from a cloth material, but is not limited to this. The cleaning means body can also be changed to a foam material, a rubber material, or the like.

[0041] Therefore, by inserting the cleaning rod 21 through the cleaning hole 6, it is possible to clean the surface of the heating roller Fh with the felt 22, and to clean the gap between the heating roller Fh and the tip 2a of the downstream sheet guide 2. Here, the gap between the heating roller Fh and the tip 2a of the downstream sheet guide 2 is disposed below the apex 9 of the heating roller Fh. In contrast, the cleaning rod 21 in the first embodiment is configured to be elastically deformable, and by pushing the cleaning rod 21 in, the tip of the cleaning rod 21 bends downward, allowing the felt 22 to enter the gap. In addition, in the first embodiment, the cleaning stick 21 is inserted to push out dust such as paper powder and fillers such as calcium carbonate and talc that have accumulated in the gap toward the fixing area Q5, and after cleaning with the cleaning stick 21, the test paper is transported and the pushed-out dust adheres to the test paper, so that the dust can be collected. This is not a limitation, and it is also possible to attach an adsorbent to the felt 22 and adsorb the dust to the cleaning stick 21 side and collect it. Alternatively, instead of the cleaning stick 21, a suction type vacuum cleaner that sucks in dust together with air can be used as the cleaning means.

[0042] (Function of Example 1) In the copying machine U of the first embodiment having the above-mentioned configuration, the recording paper S that has passed through the fixing device F is transported downstream while contacting the downstream sheet guide 2. At this time, due to contact and friction between the recording paper S and the downstream sheet guide 2, powder such as paper powder and fillers such as calcium carbonate are released from the recording paper S. The released powder floats and falls onto the surface of the heating roller Fh below. The powder that falls onto the heating roller Fh is likely to accumulate in the narrow gap between the heating roller Fh and the downstream sheet guide 2 as the heating roller Fh rotates. If the powder accumulates over time, there is a risk that the fixing temperature will be locally insufficient, causing fixing failure, paper jams, damage to the heating roller Fh, etc. The inventors' research confirmed that the accumulation of powder is not only likely to occur when recording paper S containing a large amount of paper powder or filler (white powder, calcium carbonate, etc.) is used, but also at specific positions in the paper width direction. In the paper width direction, the accumulation was prominent at the position of the feed roller Rs1. This is because, when the stopped recording paper S is fed, the recording paper S is subjected to pressure as it is sandwiched between the retard roller Rs2 and the feed roller Rs1 rotates, rubbing or handling the surface of the recording paper S. Therefore, it is presumed that the binding of the paper powder and filler to the recording paper S becomes loose when the recording paper S is fed by the feed roller Rs1, and the paper powder and the like are detached by contact with the downstream sheet guide 2, and are likely to accumulate downstream of the fixing area Q5.

[0043] Conventional cleaning techniques that use a roller that contacts the entire area of ​​the heating roller Fh are difficult to deal with the accumulation of powder at specific locations that correspond to the widthwise positions of the feed roller Rs1. In other words, if the cleaning capacity is ensured at a specific location, the cleaning capacity will be excessive for most other areas. If the cleaning capacity is excessive, the heating roller Fh is likely to wear out due to the pressure and rubbing of the cleaning roller. On the other hand, if the cleaning capacity of the cleaning roller is set to correspond to areas other than the specific location, there is a problem of insufficient cleaning capacity at the specific location. In contrast to these, in the first embodiment, a cleaning hole 6 is provided at a position corresponding to the feed roller Rs1, and cleaning is possible with the cleaning rod 21. Therefore, accumulation of powder on the downstream side of the fixing area Q5 can be eliminated.

[0044] (Example of change) Although the embodiments of the present invention have been described above in detail, the present invention is not limited to the above embodiments, and various modifications can be made within the scope of the gist of the present invention described in the claims. Modifications (H01) to (H05) of the present invention are illustrated below. (H01) In the above embodiment, a copier U is shown as an example of an image forming apparatus, but the present invention is not limited to this and may be configured as, for example, a printer, a FAX, or a multifunction machine having multiple or all of these functions. Also, the present invention is not limited to an electrophotographic image forming apparatus and may be applied to any image forming apparatus such as an inkjet type or a thermal transfer type.

[0045] (H02) In the above embodiment, a configuration in which four color developers are used as the copier U is exemplified, but this is not limited to this and can also be applied to, for example, a monochrome image forming device or a multi-color image forming device having three or less colors or five or more colors. (H03) In the above embodiment, an endless intermediate transfer belt B is exemplified as an example of an image holding means, but the present invention is not limited to this. For example, the present invention can be applied to a cylindrical intermediate transfer drum, a photosensitive drum, or a photosensitive belt. The present invention can also be applied to a configuration that does not have an intermediate transfer body and records an image directly from a photosensitive body onto recording paper S.

[0046] (H04) In the above embodiment, the position of the cleaning hole 6 is exemplified as being provided at one location in the width direction, but this is not limiting. It is also possible to provide the cleaning hole 6 at two or more locations depending on the location where powder is likely to accumulate. Therefore, if powder is likely to accumulate at a location other than the width direction position of the feed roller Rs1, it is also possible to provide the cleaning hole 6 at a location other than the feed roller Rs1. (H05) In the above embodiment, it is preferable to provide the cleaning protection part 12a on the harness cover 12, but this is not limited to this. It is also possible to provide the cleaning protection part 12a separately from the harness cover 12. It is also possible to provide a configuration without providing the cleaning protection part 12a.

[0047] (Additional Note) (((1))) a fixing means for fixing the image on the medium; a guide means arranged downstream of the fixing means in a medium transport direction to guide the medium; a cleaning entry means provided in correspondence with a gap between the fixing means and the guiding means, for allowing a cleaning means to enter the gap; A fixing device comprising: (((2))) a conveying means arranged upstream of the fixing means in a conveying direction of the medium and conveying the medium, the conveying means being arranged at a predetermined position in the width direction of the medium, the cleaning entry means being provided at a position corresponding to a position of the conveying means in the width direction; The fixing device according to (((1))) is characterized by comprising: (((3))) the conveying means being constituted by a paper feeding means through which the medium is fed; The fixing device according to (((2))) is characterized by comprising: (((4))) the cleaning access means being an opening formed in a housing of the fixing means; The fixing device according to any one of ((1))) to (((3))), comprising: (((5))) the housing in which wiring to the fixing means is arranged; a protection means for covering and protecting the outside of the wiring, the protection means having a blocking means for blocking the opening; The fixing device according to (((4))) is characterized by comprising: (((6))) An image holding means; a transfer means for transferring the image held on the image holding means to a medium; A fixing device according to any one of ((1)) to ((5))) for fixing an image transferred to a medium; An image forming apparatus comprising:

[0048] According to the fixing device of (((1))), it is possible to eliminate accumulation of powder on the downstream side of the fixing area. According to the fixing device of (((2))), it is possible to eliminate accumulation of powder at a position corresponding to the conveying means where the powder is likely to accumulate locally. According to the fixing device of (((3))), it is possible to eliminate accumulation of powder at a position corresponding to the paper feed means where powder is likely to accumulate locally. According to the fixing device of (((4))), the powder can be removed through the opening in the housing. According to the fixing device of (((5))), the fixing means can be protected by the blocking means. According to the image forming apparatus of (((6))), accumulation of powder can be eliminated downstream of the fixing area. [Explanation of symbols]

[0049] 1a...Housing of fixing means, 2... Guidance means, 6...Cleaning entry means, opening, 7…Gap, 11…Wiring, 12...protective measures; 12a…blocking means, 21...Cleaning means, F: Fixing device, Fh: fixing means; PRy, PRm, PRc, PRk...image holding means, Rs1: conveying means, paper feeding means, S...medium, T1+T2+B: transcription means; U...Image forming device.

Claims

1. a fixing means for fixing the image on the medium; a guide means arranged downstream of the fixing means in a medium transport direction to guide the medium; a cleaning entry means provided in correspondence with a gap between the fixing means and the guiding means, for allowing a cleaning means to enter the gap; A fixing device comprising:

2. a conveying means arranged upstream of the fixing means in a conveying direction of the medium and conveying the medium, the conveying means being arranged at a predetermined position in the width direction of the medium, the cleaning entry means being provided at a position corresponding to a position of the conveying means in the width direction; The fixing device according to claim 1 , further comprising:

3. the conveying means being constituted by a paper feeding means through which the medium is fed; The fixing device according to claim 2 , further comprising:

4. the cleaning access means being an opening formed in a housing of the fixing means; The fixing device according to claim 1 , further comprising:

5. the housing in which wiring to the fixing means is arranged; a protection means for covering and protecting the outside of the wiring, the protection means having a blocking means for blocking the opening; The fixing device according to claim 4 , further comprising:

6. An image holding means; a transfer means for transferring the image held on the image holding means to a medium; a fixing device according to any one of claims 1 to 5 for fixing an image transferred onto a medium; An image forming apparatus comprising:

Images