JP2009122554A - Fixing apparatus, image forming apparatus, cleaning unit, and cleaning method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fixing device which prevents an occurrence of an offsetting phenomenon with a cleaning means having a web and a cleaning roller, an image forming apparatus with the fixing device, a cleaning unit and a cleaning method in the image forming apparatus. <P>SOLUTION: In the fixing device provided with the cleaning means for cleaning a heating roller, the cleaning means has a sheet section and a cleaning roller. The sheet section can be rolled up as a roll, the heating roller is abutted to one surface of the sheet section and the cleaning roller is abutted to another surface of the sheet section. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a fixing device used in an image forming apparatus such as a copying machine, a printer, a facsimile, or a complex machine thereof. In particular, the present invention relates to a fixing device used in an electrophotographic image forming apparatus for recording an image on a recording medium, and fixing by fixing a toner image by passing the recording medium after transferring a toner image between a heating member and a pressure member. The present invention relates to a cleaning technique for offset toner in a fixing device that prevents toner attached to a heating member such as a heating roller and a pressure member from moving to a recording medium.

A conventional heat fixing apparatus is configured such that a transfer paper on which an unfixed toner image is placed is passed between a fixing roller having a heat source inside and a pressure roller, and the transfer paper on which an unfixed toner image is placed. Is fixed by heating and pressing. In order to prevent toner from adhering to the fixing roller side, a film having releasability is coated on the surface of the fixing roller. A phenomenon called offset in which the toner adheres to the fixing roller from the transfer paper may occur depending on conditions such as the environment at the time of fixing and the transfer paper. It is known that the offset toner remains on the fixing roller or the pressure roller in contact therewith, and is eventually transferred to other transfer paper or the like, thereby fouling the image.
In order to prevent this, the fixing roller is provided with a cleaning member such as a cleaning web or a cleaning roller. The cleaning member is in pressure contact with the fixing roller and collects the offset toner.
For example, as a cleaning web type invention, there is known an invention in which a web wound around a feed roller is brought into contact with a heating member by a pressing roller and cleaned while being collected by a winding shaft (see Patent Document 1).

  In recent years, the fixing device is compatible with zero energy standby mode (ZESM) and is energy-saving so that it can energize the heat source (heater) during standby (while waiting for the image forming process after power input). Is cut off and energized at the start of image formation to raise the temperature of the fixing roller to a temperature at which the toner is fixed. For this reason, the thickness of the fixing roller or the like is reduced to 1 mm or less to increase the temperature responsiveness and shorten the time required for fixing to about 10 seconds, which is a specification that combines user-friendliness and energy saving. In such a configuration, since the heat capacity of the fixing roller is small, the temperature distribution of the fixing roller varies depending on the part due to the influence of the heat transfer to the contact member of the fixing roller, for example, the heat transfer to the transfer paper, the surrounding air flow, etc. It becomes easy to change greatly. There is a method to make the temperature distribution uniform by installing multiple temperature control means on the fixing roller, but multiple heater wiring and temperature detection means to control uniformly according to each size or operation mode of the fixing roller This arrangement is impossible from the viewpoint of space and cost.

  If the temperature distribution of the fixing roller becomes non-uniform, problems such as the occurrence of offset caused by mismatching fixing conditions and the shortening of the roller life due to thermal deterioration due to non-uniform heat occur. In particular, there is a phenomenon (hereinafter referred to as “reverse transfer”) in which a toner lump accumulated on a cleaning roller in a toner using a polymerization method is retransferred to a transfer sheet. This phenomenon occurs remarkably in the case of a small size as compared with the maximum size that can be passed. This is because, in the case of a small size, since the area in contact with the fixing roller is small, it contacts the fixing roller only in a narrow area range, so heat is not taken away in other parts. The temperature does not decrease, and the temperature decreases only in the small size paper passing portion. Then, since the temperature detection means corresponding to the small size paper passing portion instructs the lighting of the heater, the temperature of the non-paper passing portion which is the other portion rises unnecessarily. The toner adhering to the part of the cleaning roller is also melted and transferred to normal paper passing therethrough.

On the other hand, paying attention to the toner used, the toner used for energy saving of the fixing device is also becoming popular for lowering the melting point.
Due to the low melting point, the fixing temperature can be set lower than that of the conventional one, but this is easily affected by the temperature distribution of the fixing roller, and offset is likely to occur.
Furthermore, in order to improve the image quality, the toner has become smaller in particle size and polymerized toner, and it is becoming easier to offset.
When the offset toner increases, the toner adheres to the separation claw and the thermistor. In the configuration in which the web is in contact, the toner is reversely transferred from the portion to the fixing roller, and the toner is collected on the web. However, there is a limit to the amount of toner collected on the web, and when the offset toner amount increases, a part of the toner blocked by the web and the fixing roller slips out and a slip-through image is formed in which the toner adheres on the image. Therefore, it is possible to increase the amount of web winding so that the new web surface comes into contact with the fixing roller.
However, when the web winding amount is increased, the web unit itself is increased, the running cost is increased, and at the same time, the layout has a larger volume, which is disadvantageous.

In addition, when only the cleaning roller is brought into contact with the fixing roller, if the amount of offset toner adhering to the cleaning roller increases, a part of the adhering toner is dissolved and divided by the heat caused by continuous paper passing, and the offset toner is recovered. Performance (adhesiveness (ability to stick and remove offset toner) ≒ cleaning performance) decreases, or a part of all offset toner collected by the adhesion of the cleaning roller is reversely transferred again to the fixing roller. There is a problem that toner melts out. Offset toner is more likely to occur on transfer paper having a larger image area, and reverse transfer is more likely to melt from the cleaning roller because the temperature of the non-sheet passing portion rises when a small-size transfer paper is continuously passed.
For example, Patent Document 1 discloses an invention of a fixing device that performs effective cleaning, in which the web is separated from the heating roller when the temperature of the fixing roller is lower than a predetermined temperature, and is contacted at a temperature higher than the predetermined temperature. Yes.
According to the present invention, when collecting the residual offset toner on the fixing roller, it is effective to idle while keeping the web (clean waste) in contact during non-passage such as during standby. When idling, motor noise and abnormal noise are generated, so that it is disclosed that the rotating torque is lowered as much as possible.

Patent Document 2 discloses an invention that discloses a conventional web mechanism.
Further, Patent Document 3 discloses an invention of a cleaning device. Specifically, a cleaning roller that is in contact with a fixing rotator of a fixing device and is rotatably disposed, and the fixing rotator, A cleaning web movably disposed in contact with the cleaning roller, and the cleaning web contacts the surface of the fixing rotator on the downstream side of the cleaning roller in the rotation direction of the fixing rotator. And is moved so as to contact the surface of the cleaning roller after contacting the surface of the fixing rotating body.
Japanese Patent No. 3364555 JP-A-10-333480 Japanese Patent No. 3572835

However, none of the publications pays attention to the fact that both sides of the web are used effectively, although there is a common point regarding the cleaning of the heating roller surface using the web, and at the same time the clean surface of the web. There is no suggestion of cleaning the cleaning roller on the side.
The present invention has been made in consideration of the above-described circumstances, and in a fixing device having a cleaning means having a web and a cleaning roller, a fixing device capable of preventing the occurrence of an offset phenomenon, and the fixing device. It is an object of the present invention to provide an image forming apparatus, a cleaning unit, and a cleaning method in the image forming apparatus.

In order to solve the above problems, the invention according to claim 1 is a fixing device having a cleaning unit for cleaning a heating roller, wherein the cleaning unit includes a sheet portion and a cleaning roller, and the sheet portion Can be wound in a roll shape, and the heating roller is brought into contact with one surface of the sheet portion, and the cleaning roller is brought into contact with the other surface of the sheet portion.
The invention according to claim 2 is a fixing device that fixes a toner image on the recording medium on the recording medium through a recording medium such as paper between a heating roller and a pair of fixing rollers, and the fixing device Comprises a cleaning means for cleaning the heating roller, the cleaning means having a rollable sheet portion and a cleaning roller, the sheet portion being in contact with the heating roller and the first surface of the sheet portion. The cleaning roller is in contact with the outer peripheral surface in a state where the second surface of the sheet portion different from the first surface is wound.

According to a third aspect of the present invention, in the fixing device according to the first or second aspect, the cleaning roller can contact the heating roller and is driven to rotate.
The invention according to claim 4 is characterized in that the cleaning roller is capable of coming into contact with and separating from the heating member (both contact and separation are possible). It is a fixing device.
According to a fifth aspect of the present invention, in the heat fixing apparatus according to any one of the first to fourth aspects, the cleaning roller has a heating means inside, and an elastic layer is provided on the roller surface. And
According to a sixth aspect of the present invention, in the heat fixing apparatus according to any one of the first to fifth aspects, the cleaning roller is in contact with the heating roller during paper passing and is separated during non-paper passing. To do.
According to a seventh aspect of the present invention, in the heat fixing apparatus according to any one of the first to sixth aspects, the cleaning roller rotates during paper passing and is opened during non-paper passing.
The invention described in claim 8 is a cleaning unit having at least a roll-upable sheet body and a cleaning roller, and is detachable from the main body of the image forming apparatus.

According to a ninth aspect of the invention, there is provided an image forming apparatus having the fixing device according to any one of the first to seventh aspects or the cleaning unit according to the eighth aspect.
According to a tenth aspect of the present invention, there is provided a cleaning method for removing contaminants including offset toner on the heating roller in a fixing device that fixes toner on a recording medium such as paper by a fixing roller paired with a heating roller. A step of contacting the heating roller by a sheet portion having a sheet member for wiping off the offset toner on the heating roller, a feeding unit, and a winding unit; and the contact of the wound sheet member A second surface that is different from the surface is an outer peripheral surface, and the outer peripheral surface in the state of the outer peripheral surface in the wound state is brought into contact with the cleaning roller that can come into contact with and separate from the heating roller. And a step of cleaning the cleaning roller.

  According to the present invention, since the web surface in contact with the fixing roller (heating roller) is wound toward the center of the web winding shaft, the outer surface of the web winding shaft always has a clean surface on the back side. By collecting offset toner on the cleaning roller with this clean surface, both sides of the sheet body such as the web can be effectively used without waste, and the consumption of the web and the like can be reduced to save space. It is possible.

Hereinafter, a fixing device of the present invention will be described in detail with reference to the drawings.
Fixing Device FIG. 1A is a schematic view of a main part showing a cleaning unit used in the fixing device of the present invention. FIG. 1B is a view for explaining cleaning of toner (residual toner, etc.) that does not contribute to image formation by the web around the web winding shaft.
The fixing device of the present invention has a heat fixing roller (heating roller) 30 having a heat generating means inside, and a pressure roller 32 that presses the heat fixing roller 30, and comes into contact with the heat fixing roller 30 to be a cleaning unit. (See FIG. 3).
As shown in FIG. 2, the cleaning unit 150 has a sheet-like sheet body 150a. In the following description, the sheet body 150a will be described using a web. The sheet member used in the present invention is a sheet-like sheet member that can clean the fixing surface of the heat fixing roller used in the fixing device, and preferably is a material that does not melt by the heating temperature of the heat fixing roller 30. Is used. In the following description, the sheet body feed shaft and the like are referred to as a web feed shaft. Such a web 150a, a web feed shaft 151, a pressing roller 152 for bringing the sheet-shaped web 150a into contact with the heat fixing roller 30, a web winding shaft 153, and a heat fixing roller for the sheet-shaped web 150a. The cleaning roller 160 is in contact with another surface different from the 30 contact surface. As shown in FIG. 5, the cleaning unit 150 may be a single unit that can be attached to and detached from the main body of the image forming apparatus (cleaning unit). Such a cleaning unit includes at least a sheet body (web) and a cleaning roller, and can be used as the cleaning unit 150 in the fixing device of the present invention.

2A is a detailed view of the main part of the cleaning unit, and FIG. 2B is a part of the part a (part indicated by a dotted line) in FIG. 2A viewed from the axial direction with the transmission means as the center. FIG.
As shown in FIG. 2, the cleaning unit 150 that contacts the heat fixing roller 30 is provided with the cleaning roller 160 in contact with the heat fixing roller 30 on the upstream side, and a sheet-like web 150 a on the downstream side. By 152, it is in contact with the heat fixing roller 30. Further, the web winding shaft 153 is wound as an inner peripheral surface of the winding shaft (web winding roller) 153 so as to wind the contact surface a of the web 150a with the heat fixing roller 30 described above. The cleaning roller 160 is configured to come into contact with a different surface (the outer peripheral surface of the wound web winding roller).

  As the web (sheet body) 150a, a heat-resistant non-woven fabric or woven fabric (clean cloth or the like) is used. For example, a release agent such as silicone oil may be impregnated, and a surfactant or the like may be further impregnated. The cleaning surface (contact surface) of such a cleaning web 150a is, as shown in FIG. 1B, the inner peripheral surface a of the winding shaft (sheet winding roller) 153, that is, the contact surface. The surface is wound on the inner diameter side (the surface on the side of the a-side inner peripheral surface in FIG. 1B), and the outer peripheral surface side of the web winding shaft (sheet body winding roller) 153 The cleaning roller 160 (the lead line does not reach the roller: excuse me. I corrected it) is in contact with b. For this reason, the surface of the web 150a that is in contact with the fixing roller (the surface on the a side in FIG. 1B) is wound toward the center of the web winding shaft 153. The wound outer peripheral surface is always a clean surface behind the contact surface of the web 150a, and the clean surface b collects the offset toner T2 on the cleaning roller 160, and only the contact surface of the web 150a. In addition, both surfaces of the web 150a can be used effectively and efficiently without waste, and it is possible to reduce the consumption of the web and contribute to space saving.

  The cleaning roller 160 is in contact with the heat fixing roller 30 and is driven to rotate in the direction of the arrow shown in FIG. 2A (clockwise direction in this figure). For this reason, the cleaning roller 160 is brought into contact with the heat fixing roller 30 and is driven to rotate, whereby the offset toner T2 on the cleaning roller 160 is actively collected on the web 150a which is a sheet body, and the cleaning roller 160 is moved. It can be kept clean and maintain high cleaning properties. In particular, if the polymer remains attached to the cleaning roller 160, the cleaning roller 160 may deteriorate due to melting with the polymer, or even if the polymer component of the toner that should have been removed has a low concentration. It also has an effect of preventing adhesion of new offset toner by preventing deterioration such as elution and spreading to the whole and forming filming at an early stage.

  The sheet member used in the fixing device of the present invention is wound after the sheet member is brought into contact with the heat fixing roller, and wound around the winding roller with the contact surface with the heat fixing roller as an inner peripheral surface. The cleaned outer peripheral surface of the sheet body is placed in contact with the cleaning roller 160 so as to clean the cleaning roller 160. However, the winding roller 153 is used as a feed roller, and cleaning is performed. After cleaning the dirt derived from the offset toner on the cleaning roller by contacting with the roller 160, the surface on the peripheral surface side (the surface on the a side in FIG. 1B) without the clean surface (153 as the feed roller) Is brought into contact with the heat fixing roller 30 by the contact roller 152, and the offset toner on the heat fixing roller 30 and the contaminants derived from the toner are removed. It can be.

The invention of the cleaning method of the present invention is a cleaning method for removing contaminants including offset toner on the heating roller in a fixing device that fixes toner on a recording medium such as paper by a fixing roller paired with a heating roller. A step of contacting the heating roller by a sheet portion having a sheet member for wiping off the offset toner on the heating roller, a feeding unit, and a winding unit; and the contact of the wound sheet member A second surface that is different from the surface is an outer peripheral surface, and the outer peripheral surface in the state of the outer peripheral surface in the wound state is brought into contact with the cleaning roller that can come into contact with and separate from the heating roller. And a step of cleaning the cleaning roller.
In the invention of the cleaning method of the present invention, the step of winding the first surface as the inner peripheral surface or the roller having the first surface as the inner peripheral surface is unrolled (the wound state). It may further include any of the steps of making the package unpacked. In addition, a first surface different from the second surface of the sheet body is unraveled from the state of being wound up after being brought into contact with the cleaning roller in a state where the second surface is wound up and becomes a sheet shape. When abutting against the heating roller, the surface layer of the roller for bringing the sheet-like sheet material unwrapped at the time of abutting into contact with the heating roller is a surface portion (surface coating layer) of a hollow roller 162 described later. It is preferably coated with a heat-resistant elastic layer using the same silicone rubber, fluorine resin, polyimide resin or the like.

Further, the cleaning roller 160 described above can be configured to be able to contact and separate (contact state and separation state) from the heat fixing roller 30. 1A shows the contact state of the cleaning roller 160, and FIG. 3A shows the distance of ΔL from the heat fixing roller 30 (the actual separation distance in the drawing and the width indicated by L match). 3 (B) is a partial detail view of the portion b of FIG. 3 (A) viewed from the axial direction with the transmission means as the center. Since the cleaning roller can be separated from (or can be separated from) the fixing roller, the temperature of the cleaning roller 160 is lower than when the cleaning roller is always in contact with the fixing roller, so that elution of offset toner from the cleaning roller 160 is prevented. In addition, a sensor (photo sensor) that detects the contamination of the heat fixing roller is provided to detect the contamination portion, and cleaning is performed as appropriate by repeatedly contacting and abutting or bringing it into contact. Be executed can also be in a fixing device and an image forming apparatus having the same of the present invention performs.
In the fixing device of the present invention, since the heat fixing roller and the cleaning roller 160 are configured to be separated as described above, the web winding shaft 153 is centered on the pressing roller 152 at the time of separation. The cleaning roller 160 rotates in the clockwise direction in the view described in FIG. Since the web winding shaft 153 includes a one-way clutch or a torque limiter (not shown), the web winding shaft 153 effectively prevents the web 150a from sagging without being reversely rotated by a rotating operation.

  FIG. 1 shows an example in which a cleaning roller 160 is pressed against a web winding shaft (sheet body winding roller) 153 (actually, the outer periphery of the web on the outer periphery of the shaft 153) by a pressure spring 165 as a pressing means. . As an example of this pressurizing means, as shown in FIGS. 2B and 3B, even when the cleaning roller 160 is separated from the heat fixing roller (heating roller) 30, the cleaning roller 160 and the web are arranged. Since the winding shaft (sheet body winding roller) 153 is provided in contact with the winding shaft 153, the pressure state is maintained. Accordingly, since the cleaning roller 160 is in contact with the web 150a, the offset toner T2 cleaned by the cleaning roller 160 is different from the contact surface of the web 150a (the surface of the web where the heat fixing roller 30 and the web 150a are in contact). The cleaning property of the cleaning roller 160 can always be maintained at a high level by collecting it on the surface.

  Further, as shown in FIG. 1, the offset toner collected from the surface of the fixing roller 30 is composed of the collected toner T1 by the web 150a and the collected toner T2 by the cleaning roller 160. As shown in FIG. 1, the collected toner T1 adheres to the inner diameter side of the web 150a wound toward the center of the web winding shaft 153, so that the outer peripheral surface of the web winding shaft 153 is clean on the back side. A face will appear. When the collected toner T2 from the cleaning roller 160 adheres to this clean surface, the offset toners T1 and T2 from the surface of the cleaning roller 160 are removed, and the web 150a can be used effectively.

FIG. 4 is a detailed sectional view of the cleaning roller 160 used in the fixing device of the present invention. The cleaning roller 160 includes a heat pipe 163 that heats and expands an outer tube, which is a strength member (here, a hollow roller), to a hollow roller 162 made of metal such as iron or aluminum, and then an inner tube (here, a corrosion-resistant member). In this case, the heat pipe is inserted and expanded by water pressure, and the pipe is press-fitted by a heat expansion method which is a method of making a shrink-fitted double pipe by cooling and shrinking the outer pipe. When the heat pipe 163 is heated, the heat medium (medium containing a liquid such as water: including a gel-like medium) embedded in the heat pipe 163 maintains the temperature uniformly in the axial direction of the cleaning roller. The heat uniformity in the axial direction of the roller is maintained.
The surface portion (surface coating layer) of the hollow roller 162 is covered with a heat resistant elastic layer 164 using silicone rubber, fluorine resin, polyimide resin or the like. The cleaning roller 160 has a heat pipe 163 inside, and is heated to prevent heat non-uniformity due to temperature unevenness in the axial direction of the cleaning roller, thereby preventing melting.
For the heat-resistant elastic layer 164, a material having inferior releasability than the surface layer of the fixing roller 30 (in other words, a material having better adhesion or adhesion than the surface layer of the fixing roller 30) is selected, so that the difference in releasability is reduced. It is also possible to use the cleaning roller 160 that exhibits higher cleaning performance.

Further, as shown in FIG. 5, the cleaning roller 160 is disposed at a position where it comes into contact with the fixing roller 30 as shown in FIG. 5, and during non-paper passing, as shown in FIG. It is arranged at a position to be separated. In this case, the cleaning roller 160 and the fixing roller 30 are brought into and out of contact with each other by using a clutch mechanism 202 instead of 165 (pressure suppressing means) which is a pressure adjusting mechanism for the fixing roller 30 shown in FIG. It can also be done.
Further, as described above, the cleaning roller 160 can be configured such that the surface temperature is controlled to be uniform in the axial direction as described above, so that the temperature of the cleaning roller 160 is lowered during separation. You can also As described above, the cleaning roller 160 is brought into contact with the heat fixing roller 30 only when the paper is passed, and is separated when the paper is not passed. Therefore, the cleaning roller 160 is cooled during the standby state. The removed offset toner T2 is not dissolved or softened, and it is possible to prevent the removed toner T2 from being effectively dissolved.

  When the cleaning roller 160 is in contact with the heat fixing roller 30, as shown in FIG. 2B, the driving force is transmitted from the fixing gear 201 to the cleaning roller driving gear 202 to be driven to rotate, and the heat fixing roller 160 is rotated. 30 offset toners can be positively collected, and when not passing, as shown in FIG. 3, the toner can be separated from the fixing roller 30 and the drive from the fixing gear 201 can be released. In this way, the cleaning roller 160 can reduce the torque to the fixing drive motor even if the idle rotation is performed by the cleaning operation during standby by releasing the rotation drive during non-passage, and abnormal noise is generated. Etc. can be prevented. Further, even when the heat fixing roller 30 performs idling by the cleaning operation during non-sheet passing, it is possible to keep the torque to the fixing driving motor (not shown) low.

Next, an image forming apparatus having the above fixing device will be described.
FIG. 6 is an overall schematic view of an image forming apparatus having the fixing device of the present invention. The image forming apparatus includes the fixing device of the present invention, and further includes at least a photoconductor and a transfer device.
As shown in FIG. 6, reference numeral 100 in the drawing denotes a copying apparatus main body (image forming apparatus main body). The copying apparatus main body 100 has an image reading device 200 mounted thereon and is placed on a sheet bank (one or more cassettes) 300.
An automatic document feeder (ADF) 400 that can be opened and closed up and down with the back side as a fulcrum is provided on the image reading apparatus 200.

The copying apparatus main body 100 includes a drum-shaped photoreceptor 10 as an image carrier inside.
In order to perform an image forming process, a developing device is disposed on the lower side in the order along the rotation direction (counterclockwise) A of the photoconductor 10 from the charging device 11 arranged on the left side in the drawing in order to perform image forming processing. 12, a transfer device 13 is disposed on the right side, and a cleaning device 14 is disposed on the upper side.
In the developing device 12, for example, a polymerized toner manufactured by a polymerization method is used as the toner, and the toner adheres to the electrostatic latent image on the photoconductor 10 using a developing roller so that the electrostatic latent image is a visible image. (Development).
Further, the transfer device 13 is configured by winding a transfer belt 17 between upper and lower rollers 15, 16 and presses the transfer belt 17 against the peripheral surface of the photoconductor 10 at the transfer position B.

In FIG. 6, a toner supply device 20 that supplies new toner to the developing device 12 is provided on the left side of the charging device 11 and the cleaning device 14.
Further, inside the copying machine main body 100, a sheet (recording medium: recording paper) S fed from a sheet cassette 61 (to be described later) of the sheet bank 300 is conveyed from the lower side to the upper side through the transfer position B to the stack position. A transport device C is provided.
The sheet conveying apparatus C includes a supply path R1, a manual feed path R2, and a sheet conveyance path R. In the sheet conveyance path R, a pair of registration rollers 21 is provided at an upstream position of the photoconductor 10. Is provided.
Further, the fixing device 22 of the present invention described above is provided at a downstream position of the photoconductor 10.
Further downstream of the fixing device 22, a discharge branch claw 34, a discharge roller 35, a first pressure roller 36, a second pressure roller 37, and a waist roller 38 are provided. A stacking unit 39 for stacking is provided.
The copying machine main body 100 is provided with a switchback device 42 on the right side in the drawing.

The switchback device 42 branches from the discharge branch claw 34 position of the sheet conveyance path R and leads to the switchback position 44 including the pair of switchback rollers 43, and the sheet conveyance path R again from the switchback position 44. A sheet conveying device D having a re-conveying path R4 leading to the registration roller 21.
The sheet conveying apparatus D is provided with a plurality of pairs of sheet conveying rollers 66 for conveying the sheet.
On the left side of the developing device 12 in the figure, a laser writing device 47 is provided.
The laser writing device 47 includes, for example, a laser light source (not shown), a scanning rotary polygon mirror 48, a polygon motor 49, a scanning optical system 50 such as an fθ lens, and the like.
On the other hand, the image reading apparatus 200 is provided with a light source 53, a plurality of mirrors 54, an imaging optical lens 55, an image sensor 56 such as a CCD, and the like, and a contact glass 57 is disposed on the upper surface.

The automatic document feeder 400 on the contact glass 57 is provided with a document setting table (not shown) at a document placement position and a document stack table (not shown) at a discharge position. In addition, a sheet conveyance device having a document conveyance path (not shown) for conveying a document sheet from a document setting table to a document stacking table through a reading position on the contact glass 57 of the image reading device 200 is provided. A plurality of unillustrated sheet conveying rollers for conveying the document sheet are provided.
On the other hand, in the sheet bank 300, sheet cassettes 61 for storing sheets S as recording media (recording paper) are provided, for example, in multiple stages.

Each sheet cassette 61 is provided with a call roller 62, a supply roller 63, and a separation roller 64, respectively.
On the right side of the sheet cassette 61 provided in multiple stages in the drawing, the above-described supply path R1 leading to the sheet conveyance path R of the apparatus main body 100 is formed.
The supply path R1 is also provided with several sheet conveyance rollers 66 for conveying the sheet.

The copier apparatus main body 100 is provided with a manual feed unit 68 on the right side in the drawing. The manual feed unit 68 is provided with a manual feed tray 67 that can be opened and closed. 67 is provided with the above-described manual feed path R2 for guiding the manual sheet set on the sheet 67 to the sheet conveyance path R.
Similarly, the manual feed tray 67 is provided with a calling roller 62, a supply roller 63, and a separation roller 64.
When copying using a copying machine having such a configuration, power is supplied by a main switch (not shown), and a document is set on a document setting table of the automatic document feeder 400.

In the case of a book document, the automatic document feeder 400 is opened, the document is set directly on the contact glass 57 of the image reading device 200, and the automatic document feeder 400 is closed and pressed.
When a start switch (not shown) is pressed, when a document is set on the automatic document feeder 400, the document is moved onto the contact glass 57 through the document conveyance path by the sheet conveyance roller and the image reading device 200 is moved. Drives, reads the document content, and discharges it onto the document stacking table.

On the other hand, when the document is set directly on the contact glass 57, the image reading apparatus 200 is immediately driven.
When the image reading apparatus 200 is driven, the image reading apparatus 200 moves the light source 53 along the contact glass 57 and applies a plurality of reflected lights obtained by irradiating the original surface on the contact glass 57 with the light from the light source 53. The image is reflected by the mirror 54, passes through the imaging optical lens 55, and is input to the image sensor 56, and the document content is read by the image sensor 56.
At this time, the original may be stopped on the contact glass 57 and moved toward the light source 53 to read the original content, or the original surface is irradiated with light from a fixed light source while the original is being conveyed. You may make it read sequentially.

Further, when the start switch is pressed, the photoconductor 10 is rotated by a photoconductor drive motor (not shown) at a predetermined timing, and the surface of the photoconductor is first uniformly charged by the charging device 11 using a charging roller, and then Writing is performed by the laser writing device 47 in accordance with the content of the original read by the image reading device 200 described above to form an electrostatic latent image on the surface of the photosensitive member 10, and then toner is adhered by the developing device 12. The electrostatic latent image is visualized (developed).
Further, when the start switch is pressed, the sheet S is sent out by the calling roller 62 from the sheet cassette 61 corresponding to the selected size in the plurality of sheet cassettes 61 provided in multiple stages in the sheet bank 300 at a predetermined timing, and then the supply roller 63. Separating one sheet at a time by the separation roller 64 and feeding it into the supply path R1, conveying it by the sheet conveyance roller 66, leading it to the sheet conveyance path R, abutting against the registration roller 21, and stopping it. The registration roller 21 is rotated in synchronization with the rotation of the visible toner image 10 and fed to the right side of the photoreceptor 10.
Alternatively, the manual feed tray 67 of the manual feed unit 68 is opened, the manual sheet set on the manual feed tray 67 is sent out by the calling roller 62, and separated and conveyed one by one by the subsequent supply roller 63 and separation roller 64. The sheet is fed into the manual feed path R2, is conveyed by the sheet conveying roller 66, is guided to the sheet conveying path R, and is similarly fed by the registration roller 21 to the right side of the photosensitive element 10 in time with the rotation of the photosensitive element 10.

The toner image on the photoconductor 10 is transferred to the sheet S fed to the right side of the photoconductor 10 at the transfer position B by the transfer device 13 to form an image. The residual toner on the photoconductor 10 after image transfer is removed and cleaned by a cleaning device provided in the fixing device, and the residual potential on the photoconductor 10 is removed by a neutralizing device (not shown) to start from charging. Prepare for image formation.
On the other hand, the sheet S after the image transfer is conveyed by the transfer belt 17 and put into the fixing device 22, passed between the heat fixing roller 30 and the pressure roller 32, and the heat fixing roller 30 and the pressure roller 32 rotating. The toner image on the sheet S is fixed by applying heat and pressure while being conveyed. Thereafter, the sheet S is discharged onto the discharge stack portion 39 in a state where the sheet S is bent and the bending rigidity is increased by the discharge roller 35, the first pressure roller 36, the second pressure roller 37, and the waist roller 38. Loaded.

In the image forming apparatus having the fixing device of the present invention, it is preferable that the fixing device is simultaneously cleaned by the cleaning unit of the fixing device at the time of fixing described above. For example, the contact of the cleaning roller 160 is linked with the operation of the heat fixing roller 30 or the pressure roller 32 of the fixing device to fix the toner to the heat fixing roller 30 when fixing to fix the toner on a recording medium such as paper. The cleaning process can be performed by contacting them.
In addition, when transferring an image on both surfaces of the sheet, the discharge branch claw 34 is switched. Then, the sheet having the toner image transferred to the surface is transferred from the sheet conveying path R to the reversing path R3, conveyed by the sheet conveying roller 66 to the switchback position 44, and switched back by the switchback roller 43 to be re-conveyed. It is put in the path R4, reversed, conveyed by the sheet conveying roller 66, guided again to the sheet conveying path R, and the image can be transferred to the back surface of the sheet in the same manner as described above.

(A) is a schematic diagram of a main part showing a cleaning unit used in the fixing device of the present invention, and (B) is a cleaning of toner (residual toner, etc.) that does not contribute to image formation by a web centered on the web winding shaft. It is the figure shown in order to explain. (A) is the principal part detail drawing of a cleaning part, (B) is the partial detail figure which looked at the a part of (A) figure centering on the transmission means from the axial direction. (A) is a diagram showing a state where it is separated from the heat fixing roller by a distance of ΔL, and (B) is a partial detail view of the portion b of (A) as seen from its axial direction around its transmission means. is there. It is a detailed sectional view of a cleaning roller used in the fixing device of the present invention. FIG. 2 is a detailed cross-sectional view of a fixing device including a cleaning unit of the present invention. 1 is an overall schematic diagram of an image forming apparatus having a fixing device of the present invention.

Explanation of symbols

30 heat fixing roller (heating roller), 32 pressure roller, 150 cleaning unit (cleaning means), 150a sheet body (web), 151 web feed shaft, 152 pressure roller, 153 web winding shaft, 160 cleaning roller, 161a, 161b Cleaning roller shaft end, 162 hollow roller, 163 heat pipe, 164 hollow roller surface (surface layer), 165 pressure suppression means, 201 fixing gear, 202 cleaning roller drive gear, T1, T2 recovered toner (offset toner)

Claims (10)

In a fixing device having a cleaning means for cleaning the heating roller,
The cleaning means includes a sheet portion and a cleaning roller, the sheet portion can be wound in a roll shape, the heating roller is in contact with one surface of the sheet portion, and the other surface of the sheet portion A fixing device, wherein the cleaning roller is in contact with the fixing device. A fixing device for fixing a toner image on the recording medium on the recording medium through a recording medium such as paper between a heating roller and a pair of fixing rollers;
The fixing device includes a cleaning unit that cleans the heating roller,
The cleaning means includes a rollable sheet portion and a cleaning roller, and the sheet portion is in contact with the heating roller and the first surface of the sheet portion, and the sheet portion is different from the first surface. The fixing device, wherein the fixing device is in contact with the cleaning roller in a state of an outer peripheral surface in a state where the second surface is wound.   The fixing device according to claim 1, wherein the cleaning roller is in contact with the heating roller and is driven to rotate.   The fixing device according to claim 1, wherein the cleaning roller is capable of contacting and separating from the heating roller.   The fixing device according to claim 1, wherein the cleaning roller includes a heating unit inside and an elastic layer is provided on a surface of the roller.   The fixing device according to claim 1, wherein the cleaning roller is in contact with the heating roller during paper passing and is spaced apart during non-paper passing.   The fixing device according to claim 1, wherein the cleaning roller is rotationally driven during paper passing and is released from the rotational driving during non-paper passing.   A cleaning unit having at least a rollable sheet body and a cleaning roller, wherein the cleaning unit is detachable from a main body of the image forming apparatus.   An image forming apparatus comprising the fixing device according to claim 1 or the cleaning unit according to claim 8. A cleaning method for removing contaminants including offset toner on the heating roller in a fixing device for fixing toner on a recording medium such as paper by a fixing roller paired with a heating roller,
Contacting the heating roller with a sheet portion having a sheet body for wiping off the offset toner on the heating roller, a feeding unit, and a winding unit;
The second surface, which is a surface different from the contact surface of the wound sheet body, is an outer peripheral surface, and the outer peripheral surface can be brought into contact with and separated from the heating roller in the state of the outer peripheral surface in the wound state. Cleaning the cleaning roller by bringing it into contact with a cleaning roller;
A cleaning method comprising:

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