JPH07210052A - Oil cleaning member and image forming device using the same - Google Patents

Abstract

PURPOSE:To prevent failure on an image caused when oil is transferred and stuck to a photoreceptor by improving oil removing performance on an oil cleaning member. CONSTITUTION:Nonwoven fabric 17 is pressed against the recording material carrying sheet 5g of a transfer drum by a core bar 20 on which sponge is wound, is moved in a direction shown by an arrow (K) so as to wipe out the oil on the sheet 5g. The nonwoven fabric 17 is constituted of the two layers of an oil removing layer 17a and an oil absorbing layer 17b, and also the lipophilic property of the layer 17b is made higher than that of the layer 17a. Thus, since the lipophilic property of the layer 17b is higher than that of the layer 17a, the oil removed at the surface of the layer 17a and spread inside the layer 17a is spread fartherly toward the layer 17b; however, does not return toward the layer 17a. The oil removing performance can be kept for a long time.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an oil cleaning member mounted on an image forming apparatus such as a copying machine or a laser beam printer, and an image forming apparatus using the oil cleaning member.

[0002]

2. Description of the Related Art Conventionally, there is known an image forming apparatus such as a laser beam printer for a copying machine, which is provided with an image carrier and a recording material carrier for supporting paper as a recording material.

FIG. 7 shows a schematic structure of a four-color full-color image forming apparatus as an example of such an image forming apparatus.

First, the structure of the image forming apparatus will be briefly described. A photosensitive drum 1 as an image bearing member is provided at substantially the center of the apparatus main body. The photosensitive drum 1 is rotatably supported in the direction of arrow R1, and around the periphery thereof, a primary charger 2, an exposing unit 3, a developing device 4,
A transfer device 5 and a cleaning device 6 are provided. Further, below the transfer device 5, a paper feeding / conveying unit 8 for the recording material P is arranged. The paper feeding / conveying unit 8 has a plurality of paper feeding cassettes 8a for respectively accommodating recording materials P of different sizes, a paper feeding roller 8b for feeding the recording materials P from the paper feeding cassette 8a, and a registration roller 8c. And
The transport path illustrated by the dotted line in the figure is formed. On the downstream side of the transfer device 5, a separating unit 9, a fixing device 10, and a paper discharge unit 11 are sequentially arranged.

Next, the operation of the image forming apparatus having the above-mentioned structure will be described by appropriately adding the structure. The surface of the photosensitive drum 1, which is rotationally driven in the direction of arrow R1 by a driving unit (not shown), is uniformly charged by the primary charger 2. The exposure unit 3 has a document scanning unit and a color separation filter, and irradiates the color-separated light image E or a light image E corresponding thereto. As the exposure unit 3, for example, a laser beam exposure apparatus can be used, and the uniformly charged surface of the photosensitive drum 1 is irradiated with an optical image E (for example, a yellow optical image) for each separated color, and the irradiated portion is irradiated. To remove the electric charges of and form an electrostatic latent image. The electrostatic latent image is visualized by the developing device 4. The developing device 4 includes a rotary support 4e that is driven to rotate about a central axis 4d, and four developing devices mounted on the rotary support 4e, that is, yellow, magenta, and cyan.
Developers 4Y, 4M that store black toners
4C and 4Bk. Then, the yellow developing device 4Y used for development is moved to a developing position facing the surface of the photosensitive drum 1 by the rotation of the rotary support 4e, and a yellow electrostatic latent image on the photosensitive drum 1 is transferred to the developing position via the developing sleeve. Toner is attached to form a toner image.

The yellow toner image is transferred onto the recording material P supplied from the paper feeding / conveying unit 8 to the transfer device 5. A plurality of paper feed cassettes 8a for accommodating and accommodating recording materials P having different sizes are arranged in the paper feed / conveyance unit 8, and a predetermined recording material P includes a paper feed roller 8b, a large number of conveyance rollers, and registration rollers 8c. It is supplied to the transfer device 5 at a predetermined timing. The transfer device 5 includes a transfer drum 5a, a transfer charger 5b, and an attraction charger 5 for electrostatically attracting the recording material P.
c, a suction roller 5d facing this, an inner charger 5e,
The transfer drum 5a, which has an outer charger 5f and is driven to rotate in the direction of arrow R5, has a recording material carrying sheet 5g made of a dielectric material which is integrally stretched in a cylindrical shape in an opening area of the transfer drum 5a. There is. Further, a transfer cleaner 13a and a backup brush 13b are arranged so as to face each other with the recording material carrying sheet 5g interposed therebetween. The recording material P supplied from the paper feeding / conveying unit 8 is adsorbed on the surface of the transfer drum 5a, rotates in the direction of arrow R5 with the rotation of the transfer drum 5a, and the yellow color on the photosensitive drum 1 is transferred by the transfer charger 5b. The toner image is transferred. The residual toner on the surface of the photosensitive drum 1 after the toner image transfer is removed, and the photosensitive drum 1 is used for the next image formation.

With the above, the transfer of the yellow toner image onto the recording material P is completed. The same image forming process is repeated for each of the other magenta, cyan, and black colors, whereby toner images of four colors are transferred onto the recording material P on the transfer drum 5a.

The recording material P on which the four color toner images have been transferred
Is separated from the surface of the transfer drum 5a by the separation charging device 9a and the separation claw 9b of the separation means 9, and is fixed by the transport belt 26 in a state where the unfixed (electrostatically attached) toner image is carried on the surface. It is transported to the container 10.

On the other hand, in the transfer drum 5a where the recording material P carried on the surface is lost, the unnecessary toner adhering to the surface is removed by the transfer cleaner 13a, and the next recording material P is formed.
It is used for carrying.

The fixing device 10 has a fixing roller 10a including a heater (heat source) and a pressure roller 10b pressed against the fixing roller 10a from below, and the recording material P is applied to the nip portion between the rollers 10a and 10b. The toner image is fused and fixed by heating and pressing while sandwiching and conveying. The recording material P after fixing is discharged onto the paper discharge tray 11, and the four-color full-color image formation is completed.

[0011]

By the way, the fixing device 10 of the full-color image forming apparatus having the structure of the above-mentioned conventional example.
The fixing roller 10a used for is generally coated with oil on its surface. This is an essential technique performed to extend the life of the fixing roller 10a itself and to prevent the toner to be fixed on the surface of the recording material P from being offset to the surface of the fixing roller 10a. Therefore, at the time of fixing, a small amount of oil is naturally applied to the surface of the recording material P. When the image is formed on the second surface of the recording material P having the oil adhered to the first surface on the front surface side, that is, at the time of double-sided image formation, the recording material P has the first surface having the oil adhered to the surface of the transfer drum 5a. Since it is carried in a state of being in close contact, first, oil is transferred to the surface of the transfer drum 5a. Further, this oil is transferred from the transfer drum 5a to the photosensitive drum 1 at the transfer portion where the surface of the transfer drum 5a and the surface of the photosensitive drum 1 contact each other.

For this reason, when image formation on both sides is performed in succession, a considerable amount of oil adheres to the surface of the photosensitive drum 1. When image formation is attempted thereafter, the adhesive force of the oil causes the recording material to move. On the other hand, the toner adheres to the originally white area on P and appears as fog, or conversely, the toner is not sufficiently transferred from the photosensitive drum 1 to the recording material P in the originally solid area. Problems such as faint images occur.

In order to solve the above problems, the present invention provides an oil cleaning member which removes unnecessary oil to form a good image, and an image forming apparatus using the same. It is intended.

[0014]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and is an oil cleaning member for contacting a member to be cleaned and wiping off oil adhering to the member to be contacted. A surface layer that is in direct contact with the member to be cleaned, and an inner layer disposed inside the surface layer, the surface layer and the inner layer having the lipophilicity of the inner layer being the lipophilicity of the surface layer. It is characterized in that it is constituted by a combination of members that are higher in oiliness.

The surface layer has a density of 0.05 to 0.80 g.
/ Cm ³ , preferably 0.10 to 0.50 g / cm ³ of cloth.

The surface layer may be formed by winding the cloth in a spiral shape to form a roller shape.

The surface layer and the inner layer may be constituted by a combination of members whose density is lower than that of the surface layer.

The surface layer may be a non-woven fabric.

The surface layer is 65 to 9 relative to the moving speed of the member to be cleaned when the member to be cleaned moves.
You may make it move at a relative speed of 5% or 105-150%.

The surface layer may move in the same direction as the moving direction of the member to be cleaned when the member to be cleaned moves.

Further, the image forming apparatus comprises a step of fixing the toner image on the recording material after transferring the toner image formed on the image carrier to the recording material carried on the surface of the transfer drum. In the image forming apparatus for performing both sides of the above, the above-mentioned oil cleaning member is provided, and the oil cleaning member wipes off the oil adhered to the surface of the transfer drum or the oil adhered to the recording material. And

[0022]

According to the above construction, the oil cleaning member is constituted by the surface layer and the inner layer, and both are constituted by a combination of members such that the lipophilicity of the inner layer is higher than the lipophilicity of the surface layer. . As a result, the oil removed on the surface of the surface layer and diffused into the surface layer has a higher lipophilicity in the inner layer even if it diffuses into the inner layer. There is no returning to.
In other words, the inner layer has a stronger oil holding power, and therefore the surface layer has a lower oil density.
Durability with respect to oil removal capacity is improved.

[0023]

Embodiments of the present invention will be described below with reference to the drawings. <Embodiment 1> FIG. 1 shows an enlarged sectional view of an oil cleaning member 17 according to the present invention, and FIG. 2 shows a vertical sectional view of an oil removing cleaning device 16 having the oil cleaning member 17. Further, referring to FIG. 3, the oil removing cleaning device 1 is added to the conventional image forming apparatus described with reference to FIG.
An example in which 6 is mounted is shown. 1 to 3, members having the same configurations and functions as those in FIG. 7 are designated by the same reference numerals, and the description thereof will be omitted.

In the oil removing cleaning device 16 of FIG. 2, a nonwoven fabric 17 as an oil cleaning member is used.
Is wound around the cored bar 18 in a web shape.
By the rotation of arrow 9 in the direction of arrow K, the core metal 18 is gradually unwound and wound around the core metal 19. Between the cored bar 18 and the cored bar 19, the non-woven fabric 17 is pressed from the back side to the surface of the recording material carrying sheet 5g by the cored bar 20 wound around the sponge layer. As a result, the non-woven fabric 17 wipes off the oil adhering to the surface of the recording material carrying sheet 5g while rubbing against it.

The entire oil removing cleaning device 16 is
The non-woven fabric 17 is swingably supported about a shaft (not shown) so that the non-woven fabric 17 comes in contact with or separates from the recording material carrying sheet 5g. The timing for cleaning is, for example, during the same rotation as when the recording material P is separated from the recording material carrying sheet 5g, that is, after the recording material P is separated, the recording material carrying sheet 5g.
It is preferable to perform this before the portion of the surface that was in contact with the back surface of the recording material P is in contact with the surface of the photosensitive drum 1. By doing so, the oil transferred from the recording material P to the surface of the recording material carrying sheet 5g is not transferred to the surface of the photosensitive drum 1.

In FIG. 1, the nonwoven fabric 17 includes an oil removing layer (surface layer) 17a and an oil absorbing layer (inner layer) 17b.
It has a two-layer structure. When cleaning, the oil removal layer 17a comes into contact with the object to be cleaned (member to be cleaned). Here, when the nonwoven fabric 17 is composed only of the oil removing layer 17a, the oil removed on the surface of the oil removing layer 17a is the oil removing layer 17a.
However, since it is a single member, the oil density is the same on both the surface side and the inside, and the durability of the oil removal capability on the surface deteriorates. Therefore, the non-woven fabric 17 is moved at a certain speed or more, and new portions of the oil removal layer 17a are successively moved to the recording material carrying sheet 5g.
It is necessary to contact the surface, which increases the running cost.

Therefore, in this embodiment, as shown in FIG. 1, the non-woven fabric 17 is made into the oil removing layer 17a and the oil absorbing layer 1.
7b and the oil absorbing layer 17b is made to have a higher lipophilicity than the oil removing layer 17a. As a result, the oil removed on the surface of the oil removal layer 17a and diffused into the oil removal layer 17a is more likely to be absorbed in the oil absorption layer 17b even if it is further diffused into the oil absorption layer 17b. Due to its high oiliness, the oil removal layer 17a
There is no returning to. That is, the oil absorption layer 17b
This means that the oil holding power is stronger, and therefore the oil removal layer 17a has a lower oil density, and therefore the durability relating to the oil removal capability is improved.

In this example, the following was used as the nonwoven fabric 17. (Oil removal layer 17a) ・ Fiber material: Nylon and polyester synthetic fiber ・ Fiber thickness: Average thickness 4 μm ・ Nonwoven fabric density: 0.170 g / cm ³・ Nonwoven fabric thickness: 500 μm (Oil absorption layer 17b ) ・ Material of fiber: polypropylene ・ Thickness of fiber: average thickness 3.5 μm ・ Density of non-woven fabric: 0.267 g / cm ³・ Thickness of non-woven fabric: 300 μm In addition, as the material of the fibers constituting non-woven fabric 17 Is
In addition to this example, polypropylene, polyester, nylon, acrylic, vinylon and synthetic fibers thereof are examined, and by making the oil absorption layer 17b material more lipophilic than the oil removal layer 17a material,
The effect of the present invention was obtained. In these materials, the order of lipophilicity is the same as that described above, with polypropylene being the highest.

Further, although these materials were used as a cloth by appropriately weaving or knitting, not as a non-woven fabric, uneven wiping of oil occurred in the woven (knitting) direction, and as an oil cleaning member. For use, the range of setting conditions was narrowed, which was not preferable. <Embodiment 2> In order to exert the effect of the present invention more effectively, the oil retaining force of the oil absorbing layer 17b may be further improved.

The oil cleaning member 17 is used in the first embodiment.
In the first embodiment, it is possible to form the oil removing layer 17a and the oil absorbing layer 17b into two layers by using the member made of the material described in the above.
But in this embodiment, the oil removal layer 1
The fiber density of the oil absorption layer 17b is made lower than the fiber density of 7a. Specifically, as the oil removing layer 17a, a nylon non-woven fabric having a density of 0.170 g / cm ³ and as the oil absorbing layer 17b, a density of 0.10 g / cm 3 is used.
³ polypropylene non-woven fabric is used. The low density of the non-woven fabric means that the distance between the fibers is widened correspondingly, and the oil can be retained in the voids. Therefore, the low density is superior in the oil retaining performance.

By doing so, the oil removed by the oil removing layer 17a becomes easier to be retained by the oil absorbing layer 17b, so that the oil can be removed more effectively. <Third Embodiment> The oil cleaning members 17 of the above-described embodiments all use cloth as the web, but instead of this, the cloth may be wound into, for example, a spiral shape to be formed into a roller shape. . By making the cloth into a roller shape, the device structure can be simplified and the running cost can be reduced as compared with the case of the web method.

A roller-shaped oil cleaning member (hereinafter appropriately referred to as "cleaning roller") 17 shown in FIG.
First, a highly lipophilic polypropylene layer is wound around the cored bar 17d as the oil absorption layer 17b, and only one layer of nylon nonwoven fabric is wound around it as the oil removal layer 17a.

Further, the cleaning roller 17 shown in FIG.
Then, a sponge layer 17c is wound around the cored bar 17d, a polypropylene layer having high lipophilicity is wound around the sponge layer 17c as the oil absorption layer 17b, and a nylon non-woven fabric is wound around the outer periphery of the polypropylene layer as the oil removal layer 17a. By providing the sponge layer 17c in this way,
When the cleaning roller 17 comes into contact with the recording material carrying sheet 5g, the nip width is widened, and the cleaning performance is further improved.

In the present embodiment, the type of FIG.
The cleaning roller 17 of 0.0 mmφ was used to clean the oil on the recording material carrying sheet 5g. The moving speed of the recording material carrying sheet 5g was 133 mm / sec, while the relative moving speed was 65 to 95%. Preferably around 80% or 105 to 15 as a relative moving speed
By moving at a speed of 0%, preferably around 120%, most of the oil on the surface of the recording material carrying sheet 5g could be removed.

Further, the rotating direction of the cleaning roller 17 at this time was examined, and the recording material carrying sheet 5 was examined.
When rotated in a direction opposite to g (the moving direction of the surface of the recording material carrying sheet 5g is opposite to the moving direction of the surface of the cleaning roller 17), the weight of the oil removed was rotated in the same direction. It is almost the same as the above, but when observing the surface of the recording material carrying sheet 5g with a microscope,
A slight amount of uneven vertical stripes was wiped in the direction of rotation. In order to solve the problem of oil transfer, no particular difference was observed due to the difference in the rotation direction of the cleaning roller 17, but as a result of experimental observation, the surface of the cleaning roller 17 moved in the same direction as the recording material carrying sheet 5g. It turned out that it is preferable to rotate it as described above. <Fourth Embodiment> In the first to third embodiments described above, the cloth-like oil cleaning member 17 or the cleaning roller 17 is provided on the recording material carrying sheet 5g in the full-color image forming apparatus having the so-called transfer drum 5a. Although it is used as a member for removing oil, instead of this, for example, a cleaning roller 17 may be arranged in the recording material conveying section to directly remove unnecessary oil from the recording material P.

FIG. 6 shows a cleaning roller 17 for removing the oil on the surface of the recording material carrying sheet 5g of the transfer drum 5a, and a cleaning roller for removing the oil directly from the recording material P disposed in the recording material conveying section (however, In the same figure, a vertical cross-sectional view of a full-color image forming apparatus including conveying rollers 11h and 11i is shown. The image forming apparatus will be described below.

The image forming apparatus shown in the figure has a lower digital color image printer section (hereinafter simply referred to as "printer section") I and an upper digital color image reader section (hereinafter simply referred to as "reader section") II. For example, the printer unit I forms an image on the recording material P based on the image of the document D read by the reader unit II.

The structure of the printer unit I and the structure of the reader unit II will be briefly described below.

The printer section I has a photosensitive drum 1 as an image carrier which is rotationally driven in the direction of arrow R1. Around the photosensitive drum 1, a primary charging device (charging device) 2, an exposure device 3, a developing device (developing device) 4, a transfer device 5, a cleaning device 6, a pre-exposure lamp 7, and the like in order along the rotation direction. Are arranged. Below the transfer device 5, that is, in the lower half portion of the printer unit I, a paper feed / conveyance unit 8 for the recording material P is arranged, and further above the transfer device 5, a separating means 9 is provided, and a downstream side of the separating means 9. A fixing device 10 and a paper discharge unit 11 are arranged (downstream in the transport direction of the recording material P).

The photosensitive drum 1 has an aluminum drum-shaped substrate 1a and an OPC (organic optical semiconductor) photosensitive member 1b covering the surface thereof, and is driven in a predetermined direction in the arrow R1 direction by a driving means (not shown). It is configured to be rotationally driven at a process speed (peripheral speed). The photosensitive drum 1 will be described in detail later.

The primary charger 2 has a shield 2a having an opening at a portion facing the photosensitive drum 1, and a discharge wire 2b arranged inside the shield 2a in parallel with the generatrix of the photosensitive drum 1.
And a grid 2c arranged in the opening of the shield 2a to regulate the charging potential. A charging bias is applied to the primary charger 2 by a power source (not shown), so that the surface of the photosensitive drum 1 has a predetermined polarity,
It is designed to be uniformly charged to a predetermined potential.

The exposure means 3 includes a laser output section (not shown) that emits a laser beam based on an image signal from a reader section II, which will be described later, and a polygon mirror 3a that reflects the laser beam.
It has a lens 3b and a mirror 3c. The exposure means 3 is
By irradiating the surface of the photosensitive drum 1 with this laser light, the photosensitive drum 1 is exposed, and the charges in the exposed portion are removed to form an electrostatic latent image. In this embodiment, the electrostatic latent image formed on the surface of the photosensitive drum 1 is separated into four colors of yellow, cyan, magenta, and black on the basis of the image of the original, and the electrostatic latent image corresponding to each color is separated. The images are formed sequentially.

The developing device 4 includes four developing devices in order from the upstream side along the rotation direction of the photosensitive drum 1 (direction of arrow R1), that is, yellow, cyan, magenta, and black colors each made of resin as a base. It is provided with developing devices 4Y, 4C, 4M, and 4Bk that store toner (developer). Each of the developing devices 4Y, 4C, 4M, and 4Bk has a developing sleeve 4a for adhering toner to the electrostatic latent image formed on the surface of the photosensitive drum 1, and has a predetermined color used for developing the electrostatic latent image. Of the developing device is alternatively arranged at a developing position close to the surface of the photosensitive drum 1 by the eccentric cam 4b,
Toner is attached to the electrostatic latent image via the developing sleeve 4a to form a toner image as a visible image. The three color developing devices other than the developing device used for development are retracted from the developing position.

The transfer device 5 includes a transfer drum (recording material carrier) 5a for supporting the recording material P on its surface, and a transfer charger (transfer means) 5 for transferring the toner image on the photosensitive drum 1 to the recording material P.
b, an attraction charger 5c for attracting the recording material P to the transfer drum 5a, and an attraction roller 5d, an inner charger 5e, and an outer charger 5f facing the attraction charger 5c, which are driven to rotate in the direction of arrow R5. A recording material carrying sheet 5g made of a dielectric material is integrally stretched in a cylindrical shape in an opening area of a circumferential surface of the transfer drum 5a which is axially supported. As the recording material carrying sheet 5g, a dielectric sheet such as a polycarbonate film is used. The transfer device 5 is configured to adsorb and carry the recording material P on the surface of the transfer drum 5a.

The cleaning device 6 includes a cleaning blade 6a for scraping off the residual toner remaining on the surface of the photosensitive drum 1 without being transferred to the recording material P, and a cleaning container 6b for collecting the scraped toner.

The pre-exposure lamp 7 is arranged adjacent to the upstream side of the primary charging device 2 and removes unnecessary charges on the surface of the photosensitive drum 1 cleaned by the cleaning device 6.

The paper feeding / conveying section 8 is provided with recording materials P of different sizes.
A plurality of paper feed cassettes 8a for stacking and storing paper, a paper feed roller 8b for feeding the recording material P in the paper feed cassette 8a, a number of conveying rollers, a registration roller 8c, etc. P is supplied to the transfer drum 5a.

The separating means 9 is a recording material P after the toner image is transferred.
Separating charger 9a for separating the transfer drum 5a from the transfer drum 5a,
It has a separating claw 9b and a separating push-up roller 9c.

The fixing device 10 is arranged below the fixing roller 10a and a fixing roller 10a having a heater inside.
Pressure roller 1 for pressing recording material P against fixing roller 10a
With 0b.

The paper discharge section 11 is provided on the downstream side of the fixing device 10, and is provided with a conveyance path switching guide 11a and a discharge roller 11.
b, a paper discharge tray 11c and the like. Further, below the transport path switching guide 11a, a transport vertical path 11d for performing image formation on both sides of one recording material P, a reverse path 11e, a stacking member 11f, an intermediate tray 11g, and a transport roller. 11h, 11i, a reversing roller 11j, etc. are arranged.

A potential sensor S ₁ for detecting the charging potential on the surface of the photosensitive drum is provided between the primary charger 2 and the developing device 4 around the photosensitive drum 1, and the developing device 4 and the transfer drum 5a are connected to each other. A density sensor S ₂ for detecting the density of the toner image on the photosensitive drum 1 is arranged between them.

Next, the reader section II will be described.
The reader unit II, which is arranged above the printer unit I, scans the document D.
An original table glass 12a on which a document is placed, an exposure lamp 12b for exposing and scanning the image surface of the original D while moving, a plurality of mirrors 12c for further reflecting the reflected light from the original D, a lens 12d for condensing the reflected light, and It has a full-color sensor 12e that forms a color-separated image signal based on the light from the lens 12d. The color-separated image signal is processed by a video processing unit (not shown) via an amplifier circuit (not shown), and is sent to the printer section I described above.

Next, the operation of the image forming apparatus having the above configuration will be described.
A brief description will be given with some configuration added. In the following description, four full-color images are formed in the order of yellow, cyan, magenta, and black.

The image of the original document D placed on the original platen glass 12a of the reader unit II is illuminated by the exposure lamp 12b and color-separated so that the yellow image is read by the full-color sensor 12e and subjected to predetermined processing. And sent as an image signal to the printer unit I.

In the printer section I, the photosensitive drum 1 is indicated by an arrow R.
It is driven to rotate in one direction, and the surface is uniformly charged by the primary charger 2. Based on the image signal sent from the above-mentioned reader unit II, laser light is emitted from the laser output unit of the exposure unit 3, and the surface of the charged photosensitive drum 1 is exposed by the optical image E via the polygon mirror 3a and the like. To do. Electric charges are removed from the exposed portion of the surface of the photosensitive drum 1, so that an electrostatic latent image corresponding to yellow is formed. In the developing device 4, the yellow developing device 4Y is arranged at a predetermined developing position, and the other developing devices 4C, 4M, 4Bk are arranged.
Is retracted from the developing position. To the electrostatic latent image on the photosensitive drum 1, yellow toner is attached by the developing device 4Y,
The toner image is visualized. The yellow toner image on the photosensitive drum 1 is transferred to the recording material P carried on the transfer drum 5a. As the recording material P, a recording material P having a size suitable for an original image is supplied from a predetermined paper feed cassette 8a to a transfer drum 5a at a predetermined timing via a paper feed roller 8b, a conveyance roller, a registration roller 8c and the like. It is a thing. The recording material P thus supplied is attracted so as to wind around the surface of the transfer drum 5a and rotates in the direction of arrow R5, and the yellow toner image on the photosensitive drum 1 is transferred by the transfer charger 5b. .

On the other hand, the photosensitive drum 1 after the toner image transfer is
The residual toner on the surface is removed by the cleaning device 6, and unnecessary charges are removed by the pre-exposure lamp 7, and the toner is provided for the next image formation starting from the primary charging.

The processes from the reading of the original image by the reader unit II to the transfer of the toner image onto the recording material P on the transfer drum 5a, the cleaning of the photosensitive drum 1 and the removal of the charge are performed by processes other than yellow. Color, ie cyan,
The same applies to magenta and black, and the four color toner images are transferred to the transfer material P on the transfer drum 5a so as to overlap each other.

Recording material P which has been transferred with four color toner images
Is separated from the transfer drum 5a by the separation charging device 9a, the separation claw 9b, and the like, and is conveyed to the fixing device 10 with the unfixed toner image carried on the surface. The recording material P is the fixing device 1.
The toner image on the surface is melted, fixed, and fixed by the transfer roller 10a and the pressure roller 10b of 0. The recording material P after fixing is discharged onto the paper discharge tray 11c by the discharge roller 11b.

When images are to be formed on both sides of the recording material P, the recording material P discharged from the fixing device 10 is immediately driven by the conveyance path switching guide 11a, and then passes through the conveyance vertical path 11d.
After being guided to the reversing path 11e once, by reversing the reversing roller 11j, the trailing end when fed is made to be the leading end, and it is retracted in the direction opposite to the fed direction and stored in the intermediate tray 11g. After that, after the image is formed on the other side again by the above-described image forming process, the sheet discharge tray 11c is formed.
Discharge on top.

The cleaning roller 1 according to the present invention is used as the transport rollers 11h and 11i that can be placed in the above-described transport vertical path 11d.
Use 7. As a result, the oil can be removed from the recording material P immediately after fixing, so that the oil hardly adheres to the recording material carrying sheet 5g.

Further, even if oil adheres to the recording material carrying sheet 5g, it can be removed by the cleaning roller 17. In the transfer drum 5a after the recording material P is separated, in order to prevent the powder from being scattered and adhered onto the recording material carrying sheet 5g and the oil from being adhered to the recording material P, the recording material carrying sheet 5g is used. Transfer cleaner 1 facing each other
3a and the backup brush 13b, and the cleaning roller 17 and the backup brush 14b as the oil removing roller described above perform cleaning. Note that such cleaning is performed before or after image formation, and at any time when a jam (paper jam) occurs.

In this embodiment, the eccentric cam 15 is operated at a desired timing, and the cam follower 5h integrated with the transfer drum 5a is operated to increase the size of the gap between the recording material carrying sheet 5g and the photosensitive drum 1. The size can be set arbitrarily. For example, during standby or when the power is turned off, if there is a charge on the transfer drum 5a, the charge acts on the photosensitive drum 1 to cause a charging memory, which deteriorates the image quality in the subsequent image formation. It is arranged to be separated from the photosensitive drum 1.

[0063]

As described above, according to the present invention,
The oil cleaning member is constituted by the surface layer and the inner layer, and both are constituted by a combination of members such that the lipophilicity of the inner layer is higher than the lipophilicity of the surface layer. As a result, the oil removed on the surface of the surface layer and diffused into the surface layer has a higher lipophilicity in the inner layer even if it diffuses into the inner layer. There is no returning to. In other words, the inner layer has a stronger oil holding power, and therefore the surface layer has a lower oil density, which improves the durability related to the oil removal ability and causes the oil transfer to the image carrier. It is possible to effectively prevent defective images.

[Brief description of drawings]

FIG. 1 is an enlarged cross-sectional view of an oil cleaning member according to a first exemplary embodiment.

FIG. 2 is a vertical cross-sectional view of the oil removing cleaning device according to the first embodiment.

FIG. 3 is a vertical cross-sectional view of a full-color image forming apparatus equipped with the oil removing cleaning device of the first embodiment.

FIG. 4 is a vertical sectional view of a cleaning roller according to a third embodiment.

FIG. 5 is a vertical cross-sectional view of another cleaning roller according to the third embodiment.

FIG. 6 is a vertical sectional view of a full-color image forming apparatus according to a fourth embodiment.

FIG. 7 is a vertical sectional view of a conventional full-color image forming apparatus.

[Explanation of symbols]

1 image carrier (photosensitive drum) 2 charging means (primary charging device) 3 exposure means 4 developing means (developing device) 5 transfer device 5a transfer drum 5g recording material carrying sheet 6 cleaning device 8 paper feed conveying section 9 separating means 10 fixing Container 11 Paper discharge section 11h, 11i Cleaning roller (conveying roller) 16 Oil removal cleaning device 17 Oil cleaning member (nonwoven fabric, cleaning roller) 17a Surface layer (oil removal layer) 17b Inner layer (oil absorption layer)

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display location G03G 15/16 // A47L 13/16 A

Claims (8)

[Claims] 1. An oil cleaning member that contacts a member to be cleaned and wipes off oil adhering to the member to be contacted, the surface layer being in direct contact with the member to be cleaned, and the surface layer being disposed inside the surface layer. An inner layer that is formed by combining the surface layer and the inner layer by a combination of members such that the lipophilicity of the inner layer is higher than the lipophilicity of the surface layer. Cleaning member. 2. The surface layer has a density of 0.05 to 0.80.
g / cm ³ , preferably 0.10 to 0.50 g / cm ³
The oil cleaning member according to claim 1, wherein the oil cleaning member is formed of the cloth. 3. The oil cleaning member according to claim 2, wherein the surface layer is formed by winding the cloth in a spiral shape to form a roller shape. 4. The surface layer and the inner layer are constituted by a combination of members in which the density of the inner layer is lower than the density of the surface layer, according to any one of claims 1 to 3. The oil cleaning member according to any one of the above. 5. The oil cleaning member according to claim 1, wherein the surface layer is a non-woven fabric. 6. The surface layer is 65 to 65 times the moving speed of the member to be cleaned when the member to be cleaned moves.
The oil cleaning member according to any one of claims 1 to 5, which moves at a relative speed of 95% or 105 to 150%. 7. The surface layer is moved in the same direction as the moving direction of the member to be cleaned when the member to be cleaned is moved, according to any one of claims 1 to 6. The oil cleaning member described. 8. An image obtained by performing a step of fixing the toner image on the recording material after transferring the toner image formed on the image bearing member onto the recording material having the surface of the transfer drum carried on the recording material. A forming apparatus, comprising the oil cleaning member according to any one of claims 1 to 7, wherein the oil cleaning member wipes off the oil attached to the surface of the transfer drum or the oil attached to the recording material. An image forming apparatus characterized by the above.