JP2016045271A - Image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fixation device that suppresses glossy streaks generated on a fixed image by local roughness on a surface of a fixation roller due to rubbing of a cleaning web.SOLUTION: A preprocess in which a fixation roller 91 is incorporated in a fixation device comprises such a rubbing process that roughens the fixation roller by contacting a rubbing member 106 with the fixation roller and rotating the rubbing member before a cleaning web 94 contacts with the fixation roller. Prescribed characteristic values are provided to specify the surface state of the fixation roller roughened, which are surface roughness [Rz][a sm value], glossiness and image ranks. Also included is cleaning mechanisms 110 and 111 for suppressing the deterioration of rubbing performance by rubbing powder generated when the fixation roller is roughened by the rubbing member. In the meantime, the rubbing member may be such a rubbing member that does not deteriorate the rubbing performance thereof or control may be executed so that the rubbing performance is not deteriorated.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a fixing device that fixes an unfixed toner image transferred to a transfer material, and an image forming apparatus such as a copying machine, a facsimile, and a printer including the fixing device.

  As a fixing device in an electrophotographic image forming apparatus, a heat roller pair type fixing device using a fixing roller and a pressure roller is generally used. The fixing roller has an elastic layer made of silicone rubber or fluorine rubber on the surface layer of an aluminum or iron core metal, and its durability is a problem.

  In particular, the surface layer of the fixing roller has a problem that it gradually becomes rough due to rubbing with the cleaning web, attack due to paper passing, dirt such as paper dust and offset toner, and contamination of foreign matter. Further, there is also a problem that, due to the above-described roughness, it appears as streak-like traces with different glossiness (hereinafter referred to as glossy streaks) on the image after fixing. The image defect is an image defect that is visually recognizable remarkably because it has different roughness and glossiness in a portion where gloss lines are generated and a portion where gloss lines do not occur.

  In order to solve the problem of the unevenness of the surface roughness, it has been proposed that a roughening member for keeping the roughness of the portion where the thermistor abuts to be in contact with the fixing roller (Patent Document 1). Thru | or patent document 5).

Japanese Patent Laid-Open No. 04-213482 JP 2005-266785 A JP 2002-62752 A JP-A-2-266383 Japanese Patent Publication No. 7-89257

  However, the above prior art has the following problems. First, there is a possibility that how the fixing roller is roughened due to differences in conditions such as the usage frequency, usage environment, component accuracy, and manufacturing method of the roughening member described in the prior art. In addition, it is difficult to diagnose a change in roughness due to the occurrence of the above-described difference in conditions. In addition, when using a roughening member such as abrasive grains that are closely blended and bonded to the surface of the SUS roller to make the surface of the fixing roller uniform, clogging with abrasive particles between the abrasive grains due to durability, Since the surface state such as peeling of the adhesive layer changes, it is difficult to maintain the rubbing accuracy.

  Further, the productivity of the fixing roller that can be rubbed per rubbing member is about 60 to 80, and it cannot be said that the durability is excellent. Therefore, the cost of twisting out when handled as a replacement part is a serious adverse effect.

  In these problems, there is a possibility that rough unevenness in the longitudinal direction or rough unevenness due to the change of the roughening member over time may occur, so that there is a possibility that the defect appears as an image defect such as a glossy streak on the fixed image.

  In order to solve the above-described problems, the present invention is characterized in that the fixing roller included in the fixing device according to the present invention includes first to fifth means.

  First, the fixing roller surface layer has a rubbing mechanism using a rubbing member that is harder than the fixing roller surface layer such as a wrapping film and has a rough surface layer. Further, the above-described rubbing mechanism is a mechanism provided in advance for a dedicated rubbing process to be performed on a new fixing roller. A fixing device comprising a means for forming a fixing roller surface state capable of suppressing glossy streaks in advance by a rubbing mechanism provided for the rubbing step.

Second, the surface state of the fixing roller and the rubbing member has characteristic values representing the surface state of the fixing roller and the rubbing member such as surface roughness Rz, sm, and glossiness. A fixing device that performs diagnosis and predicts the occurrence of gloss streaks and the life of a rubbing member.
The fixing roller surface layer satisfying the present invention is defined as Rz 0.5 [μm] or more, 1.5 [μm] or less, sm 6.0 [μm] or less, glossiness Δ4.0 or less, and image rank 4 or more. It is characterized by doing. When it deviates from the above-mentioned regulation, since it is highly possible that the gloss streak can be visually recognized, it can be predicted that the problem cannot be solved.

  Thirdly, the image rank of the gloss streak has a regulation including any of the number of gloss streaks, the gloss streak width, the gloss level, the gloss level difference, and the surface roughness.

  Fourthly, the fixing device is provided with a cleaning mechanism such as a cleaning blow and a vacuum for collecting the shavings by the rubbing member around the fixing roller.

  Fifthly, a fixing device is provided with a cleaning mechanism around the rubbing member that can collect cutting powder and the like adhering to the surface layer of the rubbing member such as a cleaning blow or a vacuum that exerts the life extension effect of the rubbing member.

  In addition, the cleaning mechanism which concerns on 4th, 5 may exhibit a cleaning effect, without necessarily having a cleaning mechanism like the structure described below. For example, when a film material stored in a roll shape is used as a rubbing member, it is conceivable that the film surface that is in contact with the fixing roller is conveyed at a low speed so that the film surface is always in contact with a new surface. By using the above-mentioned rubbing member, it is possible to adopt a configuration in which a new surface of the film can be always brought into contact even if clogging occurs, thereby obtaining an effect of collecting the shavings generated by rubbing.

  A fixing device having a rubbing step for suppressing glossy streaks according to the present invention using the above first to fifth means is provided.

  According to the present invention, as the effect of having the rubbing process as the first means, a large number of glossy streaks are transferred on both the fixing roller surface layer and the image, so that it is difficult to visually recognize the glossy streaks due to the cleaning web. Therefore, it can prevent becoming an image defect. In addition, as an effect of performing the rubbing step in advance before the fixing roller is incorporated in the fixing device, it can be introduced into the fixing device in a state in which gloss streaks can be suppressed, so that the effect of suppressing gloss streaks can be obtained from the beginning. .

  As an effect of defining the characteristic value of the fixing roller surface layer as the second means, it is possible to determine whether or not the gloss streak can be visually recognized before the rubbing step, and therefore the life of the rubbing member can be predicted. Therefore, the rubbing member can be used without waste, and cost reduction can be realized.

  By providing the image rank as the third means, it is possible to make a diagnosis in advance as to whether or not the surface of the fixing roller and the rubbing member is manifested as a glossy streak on the fixed image. Therefore, it is possible to ensure and maintain the fixed image quality.

  As an effect of having the clogging suppressing means as the fourth and fifth means, it is possible to stabilize the characteristic value of the surface of the fixing roller to be rubbed and to maintain the rubbing accuracy. Moreover, when using a roll-shaped film material as a rubbing member, the life-extending effect of the rubbing member is also high depending on the film transport conditions. Therefore, it is possible to reduce the cost by maintaining the rubbing quality and rubbing ability and extending the life.

  From the above, in order to suppress the gloss streaks transferred by the rubbing roller with the cleaning web, it is possible to suppress the gloss streaking, ensure the gloss streaking, maintain the rubbing ability, reduce costs from extending the life, etc. From the effect, it is possible to provide a fixing device capable of maintaining a good image.

FIG. 3 is a typical cross-sectional view included in the fixing roller rubbing process according to the first embodiment. 1 is an overall schematic cross-sectional view of an image forming apparatus. 2 is a cross-sectional configuration of a fixing device included in an image forming apparatus. 3 is a cross-sectional view of a rubbing process of the fixing roller according to Embodiment 1. FIG. 6 is a cross-sectional view of a fixing roller rubbing process according to Embodiment 2. FIG. It is an image figure which shows the relationship between a glossiness line and image glossiness. It is an image figure which shows the shape of the glossy stripe part transcribe | transferred to the fixing roller. It is explanatory drawing of the gloss difference of the glossy stripe on an image, and a non-glossy stripe. It is explanatory drawing of the gloss level difference by a recording material difference. It is the table | surface explaining the glossiness level difference from the image and gloss distribution. It is the table | surface explaining the reference | standard setting of the image rank. It is a graph which shows image rank transition by the image glossiness by glossy paper. It is a graph which shows the surface roughness Rz by the cleaning web seed | species, sm value, and an image rank. It is a graph which shows the relationship between the web roller total load by a cleaning web kind, peak pressure, and surface roughness Rz. It is a graph which shows the change of the web roller pressure by a web roller kind. It is a graph which shows the relationship between the rubbing member count which concerns on Example 2, and Rz. 4 is a graph showing a change in surface roughness due to durability of an RF roller according to Example 1. 3 is a graph showing a change in glossiness due to durability of an RF roller according to Example 1. 6 is a graph showing the surface roughness of the fixing roller depending on the type of cleaning web. 6 is a table showing rubbing conditions with a wrapping film according to Example 2. 6 is a graph showing a relationship between a fixing roller surface roughness Rz and an image rank for each rubbing condition according to Example 2. It is a graph which shows the rubbing capability comparison of the abrasive grain (abrasive material) adhere | attached on the wrapping film which concerns on Example 2 (by alumina material). It is a graph which shows the rubbing capability comparison of the abrasive grain (abrasive material) adhere | attached on the wrapping film which concerns on Example 2 (by carbon material).

  Hereinafter, an image heating apparatus according to the present invention will be described in detail with reference to the drawings.

[First Embodiment]
{Image forming device}
First, the overall configuration of the image forming apparatus will be described together with the image forming operation. In the image forming apparatus of the present embodiment, first, second, third, and fourth image forming units Pa, Pb, Pc, and Pd are provided in the apparatus, and toner images of different colors are latent images, This is an electrophotographic image forming apparatus which is formed through development and transfer processes and fixes the image with a fixing device.

  The first to fourth image forming units are image forming units that sequentially form cyan, magenta, yellow, and black color images, and have the same configuration except that the toner colors are different. Therefore, reference symbols a, b, c, and d shown in FIG. 1 indicate members corresponding to the cyan, magenta, yellow, and black image forming units, respectively, but in the following description, it is necessary to particularly distinguish colors. If not, the symbols a, b, c and d are omitted.

  Each image forming portion P includes an electrophotographic photosensitive drum 3 as a dedicated image carrier, and a toner image of each color is formed on each photosensitive drum 3. An intermediate transfer member 130 is installed adjacent to each photosensitive drum 3, and each color toner image formed on the photosensitive drum 3 is primarily transferred onto the intermediate transfer member 130, and this primary transfer image is secondary transferred. Is transferred onto the recording material S at a portion. Further, the recording material S to which the toner image has been transferred is fixed to the toner image by heating and pressurizing in the fixing device 9 and then discharged out of the apparatus as a recorded image.

  A drum charger 2, a developing unit 1, a primary transfer charger 24, and a cleaner 4 are provided on the outer periphery of the photosensitive drum 3, respectively. A light source device and a polygon mirror (not shown) are installed above the device.

  The laser light emitted from the light source device is scanned by rotating the polygon mirror, and the light beam of the scanning light is condensed and exposed on the photosensitive drum 3 by a reflection mirror or the like, whereby an image is formed on the photosensitive drum 3. A latent image corresponding to the signal is formed.

  The developing devices 1a, 1b, 1c, and 1d are filled with a predetermined amount of cyan, magenta, yellow, and black toners as developers, respectively, by a supply device (not shown). The developing devices 1a, 1b, 1c, and 1d develop the latent images on the photosensitive drums 3a, 3b, 3c, and 3d, respectively, and visualize them as cyan toner images, magenta toner images, yellow toner images, and black toner images. This is successively superimposed and transferred onto the rotating intermediate transfer body 130.

  Reference numeral 11 denotes a secondary transfer roller, which corresponds to the intermediate transfer member 130 and is arranged in parallel and in contact with the lower surface portion. A desired secondary transfer bias is applied to the secondary transfer roller 11 by a secondary transfer bias source. The toner image superimposed and transferred on the intermediate transfer body 130 is transferred to the recording material S conveyed in the secondary transfer portion.

  That is, in synchronization with the image formation, the recording material S passes from the feeding cassette 10 to the registration roller 12 and the pre-transfer guide, and is a secondary transfer portion that is a contact nip between the intermediate transfer body 130 and the secondary transfer roller 11. It is conveyed to. Then, a color toner image is transferred from the intermediate transfer member 130 to the recording material S by applying a bias to the secondary transfer roller 11, and the recording material S is conveyed to the fixing device 9 and heated and pressurized to fix the toner image. Then, it is discharged to the discharge section.

  On the other hand, after the primary transfer is completed, the transfer residual toner is cleaned and removed by the respective cleaners 4, and the photosensitive drum 3 is continuously prepared for the subsequent formation of the next latent image. Further, the toner and other foreign matters remaining on the transfer belt 130 are removed from the surface of the transfer belt 130 by the belt cleaner 22.

{Fusing device}
Next, the fixing device 9 used in the image forming apparatus will be described. FIG. 3 is a schematic cross-sectional enlarged view of the fixing device according to the present embodiment.

  As shown in FIG. 3, the fixing device 9 of the present embodiment passes a recording material between nips between a fixing roller (fixing member) 91 and a pressure roller (pressure member) 92 to heat and press the recording material. The toner image transferred to the recording material is fixed. An external heating roller 93 and a cleaning web 94 are in contact with the fixing roller 91.

  The fixing roller 91 of the present embodiment is formed by molding 1.0 mm of rubber rubber having a rubber hardness of 20 ° (JIS-A1 kg load) as an elastic layer on an aluminum hollow core metal having an outer diameter of φ68 mm and having a surface of 50 μm thickness. The one having an outer diameter of 70 mm coated with a fluororesin is used.

  The fixing roller 91 has a halogen heater 95 as a heating source inside, and is adjusted to 160 ° C. by a temperature sensor (not shown) and a temperature control circuit (not shown).

  Further, the fixing roller 91 according to the present embodiment uses a rubber layer formed on the metal core shaft and the surface release layer is a fluororesin tube. This fluororesin tube is composed of PFA resin (tetrafluoroethylene resin, copolymer of perfluoroalkoxyethylene resin), PTFE (tetrafluoroethylene resin), or the like.

  Furthermore, the fixing roller 91 according to the present embodiment performs a process of roughening the surface layer of the fixing roller in advance before the fixing roller 91 is incorporated into the fixing device 9. For this purpose, for example, scratches with different surface roughnesses are transferred to the surface layer of the fixing roller 91 as shown in FIG. 7 by rubbing against the cleaning web 94 that is in contact with the fixing roller 91, and glossy streaks are formed on the image. Realize. As a countermeasure, the surface layer of the fixing roller 91 is roughened under the same physical property values (Rz, Sm, glossiness, image rank) as the glossy streak portion, and has means for making it difficult to visually recognize the glossy streaks on the image. .

  The surface layer of the external heating roller 93 is more releasable than the surface layer of the fixing roller 91, and the fixing roller 91 is not worn during the surface roughness change mode in which the fixing roller 91 rotates at a peripheral speed difference. It is necessary to have a fine shape that can change the surface state of the film.

  The cleaning web 94 is configured such that a fibrous cleaning web is fed out by a fixed amount between the nip formed by the elastic roller and the fixing roller.

  The pressure roller 92, the cleaning web 94, and the external heating roller 93 are brought into contact with the fixing roller 91 in this order from the upstream side in the rotation direction. The foreign matter generated from the recording material passing between the pressure roller 92 and the fixing roller 91 is removed by the cleaning web 94, and it is difficult to reach the external heating roller 93.

In addition, the pressure roller 92, the cleaning web 94, and the external heating roller 93 are configured to be separated from the fixing roller and retracted in a standby state where there is no image forming operation signal.

  In addition to the configuration of the fixing device described above, a roughening step (hereinafter referred to as a rubbing step) according to the first embodiment using the RF roller 106 in the previous step of incorporating the fixing roller 91 shown in FIG. 4 into the fixing device. is there.

  Further, the rubbing process and the rubbing member according to the second embodiment in which a sheet-like rubbing material such as the wrapping film 102 illustrated in FIG. 5 is directly brought into contact with the fixing roller 91 may be used.

(1) {Fixing roller surface layer}
The glossy streaks on the surface of the fixing roller shown in FIG. The initial state of the surface of the fixing roller 91 having a release layer such as a fluororesin on the surface layer is a mirror surface state, and the surface roughness is Rz (JIS 10-point average roughness) of about 0.1 μm to 0.3 μm. . On the other hand, when the fixing roller 91 comes into contact with and rubs against the cleaning web 94, a part of the surface layer of the fixing roller 91 is roughened by the web fiber, toner collected by the cleaning web 94, internal and external additives, and the like. As a result, the surface roughness Rz of the roughened region increases to about 0.5 to 1.5 μm.

  The roughening of the fixing roller 91 varies depending on the surface shape of the aramid fiber of the cleaning web. It also changes depending on the hardness, cell diameter, and contact pressure of a pressing roller (hereinafter referred to as web roller 98) that makes the cleaning web contact the fixing roller.

  Since these conditions are determined by the cleaning ability of the fixing roller surface layer, the cleaning web life, and the gloss streak, it is necessary to set conditions that require a light load and high cleaning ability for the rubbing between the cleaning web and the fixing roller. .

  When fixing an unfixed toner image on the recording material S, the fixing device applies pressure and heat to the recording material S. At this time, the minute surface state of the fixing roller 91 as shown in FIG. 7 is transferred to the surface of the toner image after fixing. If the surface state on the fixing roller 91 is different, a corresponding difference in surface state occurs on the toner image, and as a result, a gloss level difference (gloss line) on the image shown in FIG. 8 occurs.

  This phenomenon is noticeable on coated paper with good surface smoothness and high gloss. The quality of paper used in offices is usually invisible. As a view from the experiment results of the present inventors, FIGS. 12, 13, 14, 15, and 19, the occurrence of gloss streaks due to contact and rubbing between the cleaning web and the fixing roller will be described below. First, depending on the type of the recording material, factors other than the recording material are some of the factors that promote the occurrence of gloss streaks when the contact pressure of the cleaning web is high or when the web fibers are rough.

  Generally, gloss is recognized as high gloss when the reproducibility of the specular reflection light image is high, and low gloss when the reproducibility is low or not. For example, when an image such as a silver salt photograph is seen under illumination of a fluorescent lamp, not only the light of the fluorescent lamp is reflected but also the shape of the fluorescent lamp is reflected. And it recognizes it as high gloss regardless of whether it is conscious or not. This indicates that the surface state of the photographic image is a mirror surface state with less unevenness. On the other hand, the opposite is true for low gloss. In the case of low gloss, the surface state of the image has large irregularities, the light from the fluorescent lamp is irregularly reflected, and the shape does not appear on the image. Thus, there is a correlation between the unevenness of the surface state on the image and the gloss.

  Therefore, particularly when fixing an image on highly glossy coated paper or the like that requires high image quality, a case where a low gloss streak is attached to the surface of the fixing roller 91 as shown in FIG. Easy to convert. That is, a defect image that can be visually recognized as a glossy streak is output on the image.

(2) {Rubbing process}
Next, the rubbing process of the fixing roller will be described. FIG. 4 is a cross-sectional schematic enlarged view of a rubbing process for roughening the fixing roller surface layer according to the first embodiment.

  The rubbing step includes a rubbing member that contacts the fixing roller 91 with a certain load. For example, it is formed by closely bonding abrasive grains as a rubbing member on an SUS304 (stainless steel) cored bar (base material) such as an RF roller 106 via an adhesive layer (intermediate layer). A rubbing layer (surface layer) is provided.

  The abrasive material for the surface layer of the RF roller 106 is made of alumina (aluminum oxide) (also referred to as alundum or molundum). Alumina is the most widely used abrasive grain, has a sufficiently high hardness compared to the fixing roller 91, and is excellent in machinability due to an acute angle shape, and is suitable as a rubbing material in this embodiment.

  The RF roller 106 is rotatably supported by support members provided at both ends in the longitudinal direction (conveyance axis direction) of the cored bar.

  The driving means of the RF roller 106 can be rotated by a motor (not shown). The RF roller 106 is pressed against the fixing roller 91 with a predetermined pressure by urging the support members at both ends in the longitudinal direction by pressure springs 107 as urging means. As a result, the RF roller 106 and the fixing roller 91 are rubbed and the characteristic value of the surface layer of the fixing roller falls within a predetermined standard.

  Further, a mechanism for cleaning the surface layer of the RF roller 106 as shown in FIG. 1 is provided. The RF roller 106 abuts and rubs against the fixing roller 91 to transfer the rubbing scratch to the surface layer of the fixing roller 91. Since the shavings generated at this time also adhere to the RF roller 106, clogging occurs between the abrasive grains on the surface of the RF roller 106, the rubbing ability is reduced, the life is shortened, and the characteristic value of the surface layer of the fixing roller 91 is changed. May occur, and the effect of suppressing gloss streaks may be reduced. In order to solve this problem, a mechanism for collecting the shavings is provided by the RF cleaning blow 110 and the RF roller cleaning vacuum 111 arranged in the counter direction with respect to the rotation direction of the RF roller 106. Similarly, the fixing roller 91 is also provided with a mechanism for collecting shavings by a fixing roller cleaning blow 108 and a fixing roller cleaning vacuum 109 arranged in the counter direction.

  The arrangement of the cleaning blow and the cleaning vacuum is for fulfilling the function of spraying and peeling off the cutting powder adhering to the surface layer of the RF roller 106 and the fixing roller 91 with air and collecting the cutting powder by sucking with air. is there.

  Further, the arrangement of the RF roller 106 and the fixing roller 91 in the counter direction has an effect of making it easier to remove the shavings adhering to the surface layer. However, the shavings adhering to the surface layer may be separated by a cleaning blow and at the same time may be scattered in the atmosphere although the amount is very small. Therefore, by arranging the cleaning vacuum in a direction perpendicular to the parallel lines of the cleaning blow, it is possible to suck and collect at the point where the shavings are scattered. Further, the scattering of the shaving powder is not necessarily 100% recoverable.

  Therefore, the RF roller cleaning blow 110 and the RF roller cleaning vacuum 111 are configured to be farthest from both ends of the rubbing process with respect to the fixing roller cleaning blow 108 and the fixing roller cleaning vacuum 109. In addition, even if a very small amount of cutting powder that cannot be collected by the cleaning vacuum is reattached to the fixing roller 91 or the RF roller 106, there are factors that affect the reduction in the rubbing ability, the shortening of the life, the fluctuation of the characteristic value, etc. Don't be.

  In the case of a rotating body such as the RF roller 106 by cleaning the shavings as described above, the contact of the cleaning member or the arrangement of the cleaning mechanism is performed immediately after the fixing roller 91 is roughened by the contact friction of the RF roller 106. By performing, the state where the shaving powder is recovered at the time of the next rubbing becomes possible. Therefore, it can be realized from the configuration of the first embodiment that the rubbing ability does not vary greatly. The cleaning of the shavings adhering to the RF roller 106 and the fixing roller 91 is not limited to the air system, and may be a means for scraping the shavings with a blade or the like, for example.

  Further, the RF roller 106 may be rotated at the contact portion (sliding portion) between the RF roller 106 and the fixing roller 91 so that the rotation direction thereof is either the forward direction or the reverse direction. Note that it is desirable that the rotational speeds of the RF roller 106 and the fixing roller 91 have a peripheral speed difference with respect to the characteristic value standard of the fixing roller surface layer.

  The rubbing process according to the first embodiment is a process that is performed in advance before the fixing roller 91 is incorporated into the fixing device. As a result, when the fixing roller is incorporated in the fixing device, even if the cleaning web comes into contact with and rubs against the fixing roller, it is difficult to visually recognize the glossy streaks alone, and it is possible to suppress image defects.

  Further, the process has means for predicting the effect of suppressing glossy lines, and the glossy line visual approval rejection standard according to claim 3 is provided. Further, it may be a regulation for maintaining the rubbing accuracy by the RF roller 106. The above-mentioned regulations and standards are used by diagnosing the gloss streak suppression effect by defining the characteristic value of the fixing roller surface layer. This characteristic value is defined as (surface roughness Rz 0.5 [μm] or more, 1.5 [μm] or less, sm 6.0 [μm] or less) (gloss level difference vs. gloss level difference Δ4.0 of non-gloss line) (Below) (image rank 4 or higher), and the gloss streak suppressing effect can be diagnosed.

  Note that the gloss level difference is calculated from the gloss level difference between the glossy stripe portion and the non-gloss stripe portion attached to the fixing roller 91 as shown in FIG. The image rank is ranked based on the gloss level difference and the visibility level of the visually visible gloss streak described in claim 4 and FIG. Further, ranking may be performed based on the number of glossy stripes visible on the image.

  For example, according to the first embodiment, as a condition for matching the characteristic value specification, the tolerance of the characteristic value specification of the rubbing process is included in the following conditions. Fixing roller 91 rotational speed 350 mm / sec, RF roller 106 rotational speed 250 mm / sec. When the rotation direction is driven by a counter, the peripheral speed difference is 600 mm / sec, the applied pressure is 4 kgf at which the RF roller 106 comes into contact with the fixing roller, and the abrasive count # 600 (alumina-based abrasive) that adheres to the surface of the RF roller. The characteristic value regulation of the first embodiment can be satisfied under the above conditions.

  The condition of the rubbing process is intended to satisfy the characteristic value definition of the surface of the fixing roller 91 and is not necessarily limited to the above-described condition.

(3) {Operation of rubbing process}
In the fixing roller 91 having a release layer such as a fluorine-based resin on the surface layer, the surface roughness Rz of the fixing roller 91 that is not rough is about 0.1 μm to 0.3 μm, and the rough surface with gloss streaks (directional No irregularities) Surface roughness Rz is about 0.5 μm to 01.5 μm.

  On the other hand, in this embodiment, the fixing roller 91 has a rubbing scratch (a thin concave portion having directionality) having a surface roughness Rz of 0.5 μm or more and 01.5 μm or less by the rubbing operation by the RF roller 106. It is attached along the rotation direction of the fixing roller 91. The rubbing scratches are formed to have a width of 10 μm and 10 or more per 100 μm in the rotation axis direction. As a result, the surface of the fixing roller 91 obtained in the rubbing process can densely transfer and arrange the stripes similar to the gloss streaks in the longitudinal direction under the rubbing conditions. Therefore, it is possible to modify the fixing roller 91 having the surface characteristics of the fixing roller 91 that can suppress the gloss streak, which is the purpose of the rubbing process, and it becomes difficult to visually recognize the surface of the fixing roller 91 and the gloss streaks of the fixed image.

  Further, the rubbing operation by the RF roller 106 is intended to make it difficult to visually recognize gloss streaks by attaching a fine rubbing scratch on the surface of the fixing roller 91, and scrapes off the surface of the fixing roller 91 to give a new surface. That is not the purpose. That is, the rubbing ability of the fixing roller 91 by the RF roller 106 is not a level at which the conventional fixing roller 91 is polished, but is a rubbing ability that only transfers the uneven shape onto the surface of the fixing roller 91. Accordingly, the amount of scraping of the release layer of the fixing roller 91 by the RF roller 106 has a level that cannot be measured or a measurement error level with respect to the life of the fixing roller 91.

  The rubbing process according to the first embodiment is a process performed before the fixing roller 91 is incorporated into the fixing device. However, when gloss streaks occur after the fixing roller 91 has been incorporated into the fixing device, this means is effective for suppressing gloss streaks even if the rubbing process according to this embodiment is performed again.

  In the rubbing step, the RF roller 106 having a detaching mechanism and a rotating mechanism is brought into contact with the fixing roller 91 when a rubbing start signal is input. The attachment / detachment operation of the RF roller 106 with respect to the fixing roller 91 is controlled through a motor by a controller as control means. In this embodiment, the controller controls the operation of the motor that transmits the driving force to the RF roller 106. The pressurizing mechanism of the RF roller 106 to the fixing roller 91 is performed by pressing both ends of the RF roller 106 with springs as described above.

  As described above, in the first embodiment, the RF roller 106 is configured to be detachable from the fixing roller 91 by the attaching / detaching mechanism, and the fixing roller to be rubbed is attached in the separated state, and the rubbing process is started. Further, the surface of the fixing roller can be modified by abutting for a desired time at a desired timing.

  In this embodiment, the RF roller 106 is driven by a dedicated drive unit, but the present invention is not limited to this. For example, the driving force may be transmitted from the driving means of the fixing roller 91 so that the driving gear rotates with a peripheral speed difference with respect to the fixing roller 91. According to this, by connecting the gears of the fixing roller 91 and the RF roller 106 at a gear ratio of 1: 2, the RF roller 106 can be driven at a surface speed that is twice the surface speed of the fixing roller 91. .

(4) {Test results}
The graph shown in FIG. 17 is an experimental result showing the transition of the surface roughness of the fixing roller 91 according to the number of times of use (for 50) in which the fixing roller 91 is rubbed with the RF roller 106. According to this, it can be seen that the 50th rubbing ability is lower than the rubbing ability of the first initial state. Further, if the surface roughness of the initial fixing roller 91 is high, the rubbing ability is remarkably lowered, and the deterioration of the abrasive grains adhering to the surface layer of the RF roller 106 (abrasion of the tip of the abrasive grains) is expected.

  On the other hand, the graph shown in FIG. 18 is an experimental result showing the change in glossiness of the surface of the fixing roller 91 according to the number of times of use (for 50) in which the fixing roller 91 is rubbed with the RF roller 106. This shows that the surface glossiness of the 50th roller is higher than the surface glossiness of the fixing roller 91 in the initial state of the first roller.

  From the experimental results shown in FIGS. 17 and 18, the rubbing ability is reduced due to the cutting edge of the abrasive grains adhering to the surface layer of the RF roller 106, and the surface layer glossiness of the fixing roller 91 is increased to support this. ing. From this, it can be seen that the life prediction of the RF roller 106 and the diagnosis of the rubbing ability are one important means for solving the problems of the present invention.

  Therefore, from the above experimental results, the life prediction and the rubbing ability diagnosis of the RF roller 106 according to the present invention can be realized by the surface roughness and the glossiness. Therefore, in addition to one of the characteristic values for the surface condition of the fixing roller, Thus, the invention according to the first embodiment including these is proposed.

{Fixing operation}
Next, the operation of the fixing device 9 used in this embodiment will be described. First, the surface of the fixing roller 91 heats the halogen heater 95 in the fixing roller 91 and the external heating roller 93 to a predetermined set temperature.

  The temperature control of the halogen heater 95 is performed by a temperature sensor (not shown) on the surface of the fixing roller, so that the fixing temperature is maintained. Further, when the pressure roller 92, the external heating roller 93, and the cleaning web that are to be brought into contact with the fixing roller are separated from each other, the temperature control of the fixing temperature is performed by rotating the contact roller.

  When the start signal of the image forming operation in the image forming apparatus is received, the recording material S is conveyed from the feeding deck. In addition, after the start signal of the image forming operation is recognized at the timing, an operation for adjusting the lateral registration adjustment for conveying the recording material according to the recording material size is performed.

  In the image forming unit, a toner image is transferred and formed on the recording material S, and the recording material S is conveyed to the fixing device.

In synchronization with the start of the image forming operation, the fixing roller 91 starts to rotate in the direction of the arrow in FIG. Further, the pressure roller 92 and the external heating roller 93 are driven by the fixing roller 91 to start rotating in the direction of the arrow in the figure. Further, when the cleaning web is brought into contact with the fixing roller, the rubbing is performed between the fixing roller and the cleaning web.

  By the operation of the fixing device in this image forming apparatus, the recording material passes through the fixing device, and the transferred toner image is fixed to the recording material and output as an image.

[Second Embodiment]
(2) {Rubbing process}
Next, a second embodiment of the present invention will be described with reference to FIG. In addition, about the thing which has the same function as what concerns on 1st Embodiment, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

  The rubbing process according to the second embodiment is characterized by having a rubbing process for roughening the surface layer of the fixing roller by the wrapping film 102 as a rubbing member. As shown in FIG. 5, the wrapping film 102 in contact with the fixing roller 91 uses, for example, a rubbing member in which a polyester film is used as a base and a carbon-based or alumina-based abrasive is bonded and arranged on the surface thereof. In this system, the fixing roller 91 is brought into contact with, rotated, and rubbed.

  The wrapping film 102 used in the rubbing process is fed from a wrapping film unused roll 103 and is applied to the backup roller 101 via a SUS roller (not shown). After that, the structure is such that it is collected by a wrapping film use roll 104 via a SUS roller (not shown) and is rotatably supported.

  Further, the surface layer of the backup roller 101 is made of urethane rubber and is set to have a rubber hardness that can be uniformly contacted in the longitudinal direction, and has a role of an assist member for the wrapping film 102 to contact the fixing roller 91 uniformly.

  Due to the configuration of the rubbing step, the wrapping film 102 abuts, rotates, and rubs with the fixing roller, and as described in the first embodiment, rubbing scratches similar to gloss streaks are generated in the longitudinal direction of the fixing roller 91. By transferring a large number of images, the effect of making it difficult to visually recognize the glossy streaks is exhibited.

  The driving means for the wrapping film 102 can be driven to rotate by a motor (not shown). The initial position of the wrapping film is stored in the wrapping film unused roll 103, and is sent out from the wrapping film unused roll 103 by the drive transmission. In addition, it is applied to the backup roller 101 before being sent out from the unused wrapping film roll 103 and is abutted and rubbed against the fixing roller 91, and is then wound and collected by the wrapping film use roll 104.

  The wrapping film 102 once collected on the wrapping film use roll 104 is assumed not to be used again because it is assumed that the tip of the abrasive grains collides with the fixing roller and has changed at least from the original shape. desirable.

  Further, the backup roller 101 is rubbed between the wrapping film 102 and the fixing roller 91 by being pressed at a predetermined pressure by the detachable movable stage 105 for rubbing, and the characteristic value of the surface layer of the fixing roller is determined. It is a process that falls within a predetermined standard.

  Further, the wrapping film 102 may be rotated at the contact portion (sliding portion) between the wrapping film 102 and the fixing roller 91 so that the rotation direction thereof is either the forward direction or the reverse direction. It should be noted that it is desirable for the rotational speed of the wrapping film 102 and the fixing roller 91 to have a peripheral speed difference with respect to the characteristic value standard of the fixing roller surface layer.

  Further, the fact that the rubbing process is performed before the fixing roller 91 according to the first embodiment is incorporated in the fixing device and the diagnosis of the gloss streak suppression effect by the characteristic value regulation of the fixing roller surface layer is provided. Is the same.

  Examples of the characteristic value definition of the fixing roller surface layer according to the second embodiment include the following conditions. For example, the fixing roller 91 rotational speed is 300 mm / sec and the wrapping film 102 rotational speed is 5 mm / sec. In accordance with this, the rotational direction is driven in the forward direction, so that the peripheral speed difference is 295 mm / sec. Further, the wrapping film 102 has a condition of an intrusion amount 0.5 mm / thickness 75 μm / abrasive grain number # 2000 (carbon-based abrasive) in contact with the fixing roller. The characteristic value regulation of the first and second embodiments can be satisfied by the above example conditions.

  However, if the surface condition changes, such as clogging generated by rubbing between the abrasive grains of the rubbing member, clogging, peeling of the adhesive layer due to durability, etc. The fact that there is a concern about the fluctuation of the characteristic value is also described in the first embodiment.

  However, in the second embodiment, the fixing roller 91 and the cleaning mechanism for the surface layer of the wrapping film 102 that is a rubbing member are not necessarily provided. At least the purpose of providing the cleaning mechanism is a means for suppressing a decrease in the rubbing ability and a fluctuation in the characteristic value of the surface layer of the fixing roller, and it is sufficient that the purpose can be achieved by other means. That is, any means provided with a rubbing member and a rubbing operation capable of maintaining the rubbing ability even when the shavings by rubbing between the fixing roller 91 and the wrapping film 102 are clogged between the abrasive grains. Good.

  For example, when the abrasive powder from the rubbing is clogged between the abrasive grains on the surface of the wrapping film 102, if the abrasive grain surface of the wrapping film 102 in contact with the fixing roller is always replaced with a new surface, the rubbing ability will not be reduced. Can be maintained. Therefore, the operation of the wrapping film 102 according to the second embodiment is such that the wrapping film 102 is always conveyed at a low speed, so that even if clogging occurs, a new surface of the film is repeatedly brought into contact, so that the rubbing ability is Almost maintainable.

  Further, since a new surface always comes into contact with the fixing roller 91 from the above operation, the risk of peeling of the adhesive layer due to durability is also reduced. Therefore, it is possible to stably rub the fixing roller against the fixing roller, and it is possible to maintain the characteristic value of the surface of the fixing roller by suppressing the rubbing ability due to clogging and peeling of the adhesive layer.

  Depending on the conveying speed of the wrapping film 102, the life extension effect is also high. Therefore, in addition to maintaining the rubbing quality and rubbing ability, it is possible to realize cost reduction due to the life extension effect.

(3) {Operation of rubbing process}
As shown in FIG. 5, the rubbing process according to the second embodiment mainly includes an operation including a detachable movable stage 105 and a rotation mechanism for the wrapping film 102. First, when a rubbing start signal is input, the backup roller 101 on which the wrapping film 102 is applied is brought into contact with the fixing roller 91 by the removable stage 105. The detachment operation of the backup roller 101 with respect to the fixing roller 91 by the detachable movable stage 105 is controlled through a motor by a controller as a control means.

  In this embodiment, the controller controls the operation of a motor that transmits driving force to the backup roller 101 to rotate the wrapping film 102. As described above, the pressing force of the backup roller 101 to the fixing roller 91 is such that both ends of the backup roller 101 are supported by arms, and the arms are connected to the detachable movable stage 105 so that the contact operation is performed. Is called.

  As described above, in Example 2, the wrapping film 102 is configured to be detachable from the fixing roller 91 by the backup roller 101 and the detachable movable stage 105, and the fixing roller to be rubbed in the separated state is attached. Then, the rubbing process is started. Further, the surface of the fixing roller can be modified by setting the contact condition for a desired time at a desired timing.

  In the present embodiment, the wrapping film 102 and the backup roller 101 are driven by dedicated driving means, but the present invention is not limited to this. For example, the driving force may be transmitted from the driving means of the fixing roller 91 so that the driving gear rotates with a peripheral speed difference with respect to the fixing roller 91. Further, the wrapping film unused roll 103 or the wrapping film use roll 104 may be provided with a dedicated drive to carry the wrapping film. For example, the backup roller 101 can be driven at a surface speed that is 1/10 times the surface speed of the fixing roller 91 by connecting the gears of the fixing roller 91 and the backup roller 101 at a gear ratio of 10: 1.

(4) {Test results}
In order to determine the number of abrasive grains (abrasive material) to be bonded to the surface layer of the wrapping film 102, a rubbing experiment of the fixing roller 91 with sandpaper as shown in FIG. 16 was performed. When the surface roughness of the fixing roller 91 was changed due to the difference in the sandpaper count, it was confirmed that the surface roughness of the fixing roller 91 was proportional to the abrasive grain size. From the result of this experiment, the abrasive count corresponding to the characteristic value definition of the surface state of the fixing roller 91 is given.

  Further, based on the basic data of the count, the surface roughness Rz, which is a part of the characteristic value of the surface state of the fixing roller 91 as a target, and the image rank are used. Experiments were conducted with various conditions. As can be seen from FIG. 21, it can be seen that the image rank varies greatly depending on the rubbing condition rather than the glossy paper type.

  Based on the experimental results, an experiment was conducted by using detailed conditions as shown in FIG. 20 by using a reference abrasive grain number and rubbing conditions. The result is a graph shown in FIGS. 23 and 24. As described above, the characteristic value of the surface state of the fixing roller 91 is determined based on the result and confirmation of reproducibility. Selected.

  From the above experimental results based on FIGS. 23 and 24, the abrasive particles (abrasive material) bonded to the surface layer of the wrapping film 102 have different rubbing ability between the carbon material and the alumina material. According to the inventor's view, when the surface of the fixing roller 91 that has been roughened by the respective abrasives is observed with a magnifying microscope, the stripes roughened by the alumina material are transferred more finely and shallowly. On the other hand, it is known that clear streaks are transferred at an appropriate depth in the streaks roughened by the carbon material. Considering from the above view, the roughening due to the alumina material has a shallow scratch and is not clear, so that the gloss streaks transferred by the cleaning web are easily visible.

  The present invention relates to a fixing device used in an image forming apparatus such as a copying machine and a rubbing process.

P image forming unit, S recording material, 1 developing device, 2 drum charger, 3 photosensitive drum,
4 Cleaner, 9 Fixing device, 10 Feed cassette, 11 Secondary transfer roller,
12 registration rollers, 22 belt cleaners, 24 primary transfer charger,
91 fixing roller, 92 pressure roller, 93 external heating roller,
94 cleaning web, 95 halogen heater, 96 web paper,
97 support rollers, 98 web rollers,
99 Web paper unused roll (feeding out),
100 Web paper roll (winding),
101 backup roller, 102 wrapping film,
103 Unused wrapping film roll (delivery),
104 Wrapping film roll (winding), 105 Detachable movable stage,
106 refresh roller (RF roller), 107 pressure spring,
108 fixing roller cleaning blow, 109 fixing roller cleaning vacuum,
110 RF roller cleaning blow, 111 RF roller cleaning vacuum,
130 Intermediate transfer member

Claims (4)

  For the fixing roller surface layer, a sliding mechanism using a rubbing member that is harder than the fixing roller surface layer and whose surface layer is rough, and a cleaning mechanism that collects shavings by the rubbing member are provided around the fixing roller. An apparatus having a rubbing mechanism and a rubbing mechanism provided around the rubbing member with a cleaning mechanism capable of collecting the shavings adhering to the surface layer of the rubbing member that exhibits the life-extending effect of the rubbing member is fixed in advance. A fixing device characterized by having a special rubbing step for enforcing a roller, so that streaks of different gloss (hereinafter referred to as glossy streaks) can be suppressed in advance on an image after fixing.   In order to roughen a smooth surface such as the surface of the fixing roller, a mechanism having a roll-shaped sheet as a rubbing member and a rubbing mechanism having a roll-shaped sheet abutting on the fixing roller and having a feeding mechanism are previously new. A fixing device characterized in that gloss streaks can be suppressed in advance by having a dedicated rubbing process for enforcing the fixing roller.   The surface condition of the fixing roller and the rubbing member is defined by the surface roughness Rz, sm, and glossiness. Rz 0.5 [μm] or more, 1.5 [μm] or less, sm 6.0 [μm] or less, gloss 3. The diagnosis of rubbing ability, the presence / absence of gloss streaks, and the prediction of the rubbing member life are performed by providing a specified range of degree Δ4.0 or less. 3. Fixing device.   4. An image rank of glossy stripes is characterized in that a good fixed image can be obtained by defining a difference in glossiness between a glossy stripe portion and a non-gloss stripe portion as Δ4.0 or less. The fixing device according to claim 1.