JP3537948B2 - Fixing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION A fixing device using a pair of heat rollers for fixing an unfixed toner image formed on transfer paper.

[0002]

2. Description of the Related Art FIG. 7 shows a heating roller 102 having a heat source 108 therein and driven to rotate in the direction of an arrow by a driving means (not shown). Pressure roller 10 that rotates following the rotation
3, a frame 111 supporting the pair of heat rollers, and a transfer sheet 106 supported by the frame 111 and having the unfixed toner T transferred to the surface between the pair of heat rollers. The fixing device 101 includes a guide member 104 and a separation claw 107 that separates a transfer sheet 106 on which the toner T is fixed from a heating roller 108. The heating roller 102 and the pressure roller 103 have a multilayer structure as shown in FIGS.

That is, the heating roller 1 shown in FIG.
02 is a sleeve that maintains heat and stores heat.
And the unfixed toner T formed on the sleeve 102b.
And a release layer 102a that performs heat transfer in contact with
The pressure roller 103 shown in FIG. 8B has a sleeve 103c for maintaining rigidity and storing heat, and a sleeve 103c for holding the heat.
c, an elastic layer 103b for forming a nip 109 (FIG. 7) between the heating roller 102 and the heating roller 102 when contacting the heating roller 102, and a separation layer formed on the elastic layer 103b and forming a surface layer. And a mold layer 103a.

A fixing process for fixing unfixed toner on transfer paper in the fixing device 101 shown in FIG. 7 will be described. The transfer paper 106 supplied to the guide member 104 by the conveying means 105 formed of a belt is guided between the pair of heat rollers via the guide member 104, and the unfixed toner T is melted by the heat of the heat roller 102, After being fused to the transfer paper 106 by the pressure of the nip 109 between the pressure roller 102 and the pressure roller 103, the toner is separated from the heating roller 102 by the separation claw 107 and discharged from the fixing device 101 through the discharge port 110.

Generally, a fixing device using a pair of heat rollers is
It is often used in an image forming apparatus using a powder toner, and the unfixed toner is melted by the heat of a heating roller, and is fused to transfer paper by the pressure between the heating roller and the pressure roller. The surface layer of the heating roller is made of a material having good releasability, such as PFA, PTFE, and FEP, in order to prevent the toner from fusing to the roller during heating and pressing.

However, when a large number of transfer papers are passed, the surface is roughened, and a modified binding organic substance of toner, paper powder, or a mixture thereof adheres to the transfer paper, thereby deteriorating the releasability. Come. When the releasability decreases, the offset phenomenon in which the toner adheres to the heating roller increases, so that the snow begins to adhere, and finally, most of the toner image is offset and the normal fixing operation is not performed.

Similarly, if the pressure roller is used for a long time, dirt adheres to the pressure roller, and abnormalities such as paper jam due to winding of the transfer paper and back dirt of the transfer paper appear.

Further, a small amount of dirt accumulates on the guide plate that guides the transfer paper to the fixing roller pair formed by the heating roller and the pressure roller each time the transfer paper passes, and is firmly heated by the heat of the fixing device. It will adhere. In such a case, smooth transfer of the transfer paper is not performed, resulting in paper jams and backside stains.

Therefore, conventionally, in order to solve the above-mentioned problems, it has been practiced to supply silicone oil to the heating roller to increase the releasability, or to remove dirt by contacting the roller or the web. I have. Japanese Patent Application Laid-Open No. 6-19357 discloses a method in which offset toner is pulverized into fine particles and returned to transfer paper.

[0010]

However, the method of providing an oil application device and a cleaning device has problems such as an increase in cost due to a complicated mechanism and an increase in maintenance work such as oil supply and replacement of the cleaning device. . In addition, there is no effective cleaning means for dirt on the guide member, and there is a problem that it must be dealt with by manual cleaning or replacement.

The present invention solves the above-mentioned problems, and can reduce the number of maintenance operations with a simple mechanism at a lower cost than in the prior art. (1) A fixing device having a self-cleaning action of a heating roller ( 2) A fixing device having a self-cleaning action of a pressure roller (3) A fixing device having a self-cleaning action of a guide member is provided.

[0012]

According to the first aspect of the present invention,
The transfer paper on which the unfixed toner image is formed has a heat source inside.
A fixing device that guides a guide member between a pair of fixing rollers including a heating roller and a pressure roller that contacts the heating roller, and fixes the toner image on transfer paper by passing between the pair of fixing rollers. Forming a layer to which at least one of the surfaces of the heating roller or the pressure roller or the guide member functions as a catalyst by irradiating light, and to which a photocatalyst that decomposes dirt on the surface is added. In addition, a light source comprising a light emitting portion and a reflecting portion for irradiating visible light or ultraviolet light to the surface of this layer is provided.

According to a second aspect of the present invention, there is provided a fixing device for performing a fixing step similar to the first aspect of the invention, wherein a sleeve for maintaining rigidity and storing heat is provided, and a sleeve formed on the sleeve and in contact with the toner image. A heating roller composed of a release layer and a heat transfer layer is provided with a photocatalyst that acts as a catalyst by irradiating light to the release layer and decomposes dirt on the surface thereof. A light source comprising a light emitting unit and a reflecting unit for irradiating visible light or ultraviolet light to the light source.

According to a third aspect of the present invention, there is provided a fixing device for performing the same fixing step as the first aspect of the present invention, wherein a sleeve for maintaining heat and storing heat is provided, and a sleeve formed on the sleeve and in contact with a heating roller. Sometimes, a pressure roller composed of an elastic layer for forming a nip between the heating roller and a release layer which is formed on the elastic layer and forms a surface layer, emits light to the release layer. A photocatalyst that acts as a catalyst by applying light and decomposes dirt on the surface is added, and a light source consisting of a light emitting part and a reflecting part that irradiates this release layer with visible light or ultraviolet light is provided. It is characterized by having.

According to a fourth aspect of the present invention, there is provided a fixing device for performing the same fixing step as the first aspect of the present invention, wherein a photocatalyst which acts as a catalyst by irradiating light to the guide member surface to decompose dirt is added. And a light source comprising a light emitting portion and a reflecting portion for irradiating the layer with visible light or ultraviolet light.

[0016]

According to the first aspect of the present invention, at least one of the surfaces of the heating roller, the pressure roller, and the guide member is formed with a layer to which a photocatalyst that acts as a catalyst by irradiating light is added. Since a light source for irradiating visible light or ultraviolet light was provided on the surface of this layer, any heating roller, pressure roller, or guide member having a surface layer to which a photocatalyst was added was not adhered to the surface layer. Self-cleaning is performed by, for example, decomposing the stains such as toner and paper dust, and transferring the dirt to transfer paper to be passed.

According to the second aspect of the present invention, the heating roller is added with a photocatalyst which functions as a catalyst by irradiating the release layer with light, and the surface of the heating roller is irradiated with visible light or ultraviolet light. Since a light source is provided, self-cleaning is performed by, for example, decomposing the dirt such as toner and paper powder attached to the surface layer as needed and transferring the dirt to transfer paper to be passed.

According to the third aspect of the present invention, the pressure roller is added with a photocatalyst which functions as a catalyst by irradiating light to the release layer, and visible light or ultraviolet light is applied to the surface of the pressure roller. Is provided, a self-cleaning is performed by, for example, decomposing the dirt such as toner and paper dust attached to the surface layer as needed and transferring the dirt to transfer paper to be passed.

According to a fourth aspect of the present invention, the guide member is formed on its surface with a layer to which a photocatalyst that acts as a catalyst by irradiating light is applied. Since a light source for irradiating is provided, the dirt such as toner and paper powder attached to the surface layer is decomposed as needed,
Self-cleaning is performed by, for example, transferring to a transfer sheet to be passed.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In a first embodiment of the present invention, as shown in FIG. 1, a heating device 8 has a heat source 8 inside a fixing device 1 and is rotationally driven in the direction of an arrow by driving means (not shown). Roller 2
A heat roller pair comprising a pressure roller 3 which abuts on the heating roller 2 and rotates following the heating roller 2;
A frame 12 supporting the pair of heat rollers, and a guide member 4 supported by the frame 12 and guiding the transfer paper 6 having the unfixed toner T transferred to the surface between the pair of heat rollers.
A separating claw 7 for separating the transfer paper 6 on which the toner T is fixed from the heating roller 2, and a light source 10 supported by the frame 12 for irradiating the surface of the heating roller 2 with visible light or ultraviolet light.
And

As shown in FIG. 2, the heating roller 2 has an aluminum sleeve 2b for maintaining heat and storing heat, and a release layer 2a formed on the sleeve 2b and in contact with the unfixed toner T to conduct heat. It consists of The release layer 2a is formed of a material obtained by adding a trace amount of a photocatalyst to a mixture of an additive which imparts conductivity and abrasion resistance with a fluororesin PFA as a main component.

In this embodiment, TiO ₂ (titanium dioxide) is used as the photocatalyst, but any other photocatalyst may be used. Aluminum is used for the sleeve 2b, and fluorine resin PFA is used for the main component of the release layer 2a. Examples of the material of the sleeve 2b include, in addition to aluminum, iron that maintains rigidity and stores heat. As a main component of the release layer 2a, PTFE, FEP, which is the same fluororesin, in addition to the fluororesin PFA, may be mentioned. The light source 10 includes a light emitting unit 10a and a reflecting unit 10b. Since the photocatalyst is efficiently activated mainly by light having a wavelength in the ultraviolet region, a fluorescent tube of about several watts is used as the light emitting unit 10a. I have.

The transfer paper 6 supplied to the guide member 4 by the conveying means 5 is guided by the guide member 4 and guided between the pair of heat rollers, and the unfixed toner T is melted by the heat of the heating roller 2 and heated. After being fused to the transfer paper 6 by the pressure of the nip 9 between the roller 2 and the pressure roller 3, the toner is separated from the heating roller 2 by the separation claw 7 and discharged from the discharge port 11 to the outside of the transfer device. In particular, in the present embodiment, a photocatalyst is added to the release layer 2a forming the surface layer of the heating roller 2, and the light source 10 for irradiating visible light or ultraviolet light to the release layer 2a is provided.
The binding dirt on the surface of the heating roller 2 is decomposed into carbon dioxide, water, and other low molecular oxides by causing a combustion reaction by active oxygen or the like generated by irradiating the photocatalyst with visible light or ultraviolet light, The particles become invisiblely small particles and adhere to the transfer paper 6 and are discharged.

FIG. 3 shows a second embodiment of the present invention. This embodiment has the same configuration as that of the first embodiment except for the layer 3a (FIG. 4) to which the photocatalyst is added and the arrangement position of the light source 20 with respect to the layer 3a. The description is omitted.

The light source 20 is disposed on the frame 12 at a position where the layer 3a (FIG. 4) formed on the surface of the pressure roller 3 to which a photocatalyst is added is irradiated with visible light or ultraviolet light. As shown in FIG. 4, the pressure roller 3 has a nip 9 between an aluminum sleeve 3c that maintains rigidity and stores heat, and a heating roller formed on the sleeve 3c and abutting against the heating roller 2. It comprises an elastic layer 3b for forming (FIG. 3) and a release layer 3a formed on the elastic layer 3b and serving as a surface layer. The release layer 3a is formed of a material in which a small amount of a photocatalyst is added to a mixture of an additive which imparts conductivity and abrasion resistance with a fluororesin PFA as a main component.

In this embodiment, TiO ₂ (titanium dioxide) is used as the photocatalyst, but any other photocatalyst may be used. Aluminum is used for the sleeve 3c, heat-resistant rubber is used for the elastic layer 3b, and fluorine resin PFA is used for the main component of the release layer 3a. As a material of the sleeve 3c, in addition to aluminum, iron or the like for maintaining rigidity can be cited. As a main component of the release layer 3a, PTFE, FEP, which is the same fluororesin, besides fluororesin PTA can be mentioned. The light source 20 includes a light emitting part 20a and a reflecting part 20b. Since the photocatalyst is efficiently activated mainly by light having a wavelength in the ultraviolet region, a fluorescent tube of about several watts is used as the light emitting part. .

The fixing step is performed in the same manner as in the first embodiment. In the present embodiment, a photocatalyst is added to the release layer 3a forming the surface layer of the pressure roller 3, and a light source 20 for irradiating visible light or ultraviolet light to the release layer 3a is provided. The binding dirt is decomposed into carbon dioxide, water, and other low molecular oxides by a combustion reaction caused by active oxygen or the like generated by irradiating the photocatalyst with visible light or ultraviolet light, and is invisible and small. The particles are attached to the transfer paper 6 and discharged.

FIG. 5 shows a third embodiment of the present invention. This embodiment is the same as the first embodiment except that the layer 4a (FIG. 6) to which the photocatalyst is added is formed on the guide plate 4 and the position of the light source 30 with respect to this layer 4a (FIG. 6). Since it has a configuration, the same reference numerals as in the first embodiment are used, and description thereof is omitted.

The light source 30 is provided at a position where visible light or ultraviolet light is applied to the layer 4a (FIG. 6) formed on the surface of the guide member 4 to which a photocatalyst is added. As shown in FIG. 6, the guide member 4 formed of a heat-resistant resin has a layer 4a to which a photocatalyst is added on the surface. In this embodiment, TiO2 (titanium dioxide) is used as the photocatalyst, but any other photocatalyst may be used. The guide member 4 is made of a heat-resistant resin, but the guide member 4 may be made of iron or the like. The light source 30 is the light emitting unit 3
0 a and serves and a reflection section 30 b, because the photocatalyst to efficiently activated with light of a wavelength of mainly ultraviolet region, the light emitting portion
And using a fluorescent tube on the order of several watts as 30 a.

The fixing step is performed in the same manner as in the first embodiment. In this embodiment, a layer 4a to which a photocatalyst is added is formed on the surface of the guide member 4, and a light source 30 for irradiating visible light or ultraviolet light to the layer 4a is provided. Stain is decomposed into carbon dioxide, water, and other low molecular oxides by a combustion reaction caused by active oxygen generated by irradiating the photocatalyst with visible light or ultraviolet light, and transferred to invisible small particles. It is attached to the paper 6 and discharged.

In the first to third embodiments, the heating roller 2, the pressure roller 3, and the guide member 4 are used, respectively.
Only one of them has a surface layer to which a photocatalyst is added, and the fixing device has a configuration in which a light source for irradiating light to the layer is provided. Is formed on at least one of a heating roller, a pressure roller, and a guide member for one fixing device, and a light source for the roller may be provided, and a combination thereof may be appropriately determined as necessary. .

[0032]

According to the first aspect of the present invention, the heat roller, the pressure roller, or the guide member having a surface layer to which a photocatalyst is added is formed of toner or paper powder adhering to the surface layer. Self-cleaning is performed by disassembling dirt such as at any time and transferring it to the transfer paper that passes through it. Since the substance, paper powder, or a mixture thereof does not adhere, the releasability can be prevented from lowering.

In particular, when this layer is formed on the surface of the heating roller, the offset phenomenon in which the toner adheres to the heating roller can be prevented, and the offset of the toner image due to the snowman-like contamination can be prevented. The fixing operation can be maintained, and when formed on the surface of the pressure roller, the use of the pressure roller over time also
Dirt can be attached to prevent abnormalities such as paper jam due to transfer paper wrapping and transfer paper back dirt.When formed on the guide member surface, a very small amount of It is possible to prevent dirt from accumulating and firmly adhering due to the heat of the fixing device, thereby preventing the transfer paper from being smoothly transported and causing paper jams and back dirt.

Further, there is no need to provide an oil application device or a cleaning device, and the catalyst activates a chemical change only and does not change itself. Therefore, problems such as an increase in cost due to a complicated mechanism and an increase in maintenance work such as oil supply and replacement of a cleaning device can be solved.

According to the second aspect of the present invention, since the heating roller has the surface layer to which the photocatalyst is added, dirt such as toner and paper powder adhering to the surface layer is decomposed as needed and the paper is passed. Self-cleaning is performed by transferring to transfer paper, etc., so even if a large number of transfer papers are passed, the surface may become rough, or the toner-modified binding organic substance, paper powder, or a mixture thereof may adhere. Because of this, it is possible to prevent the releasability from lowering.

Further, it is possible to prevent the offset phenomenon in which the toner adheres to the heating roller, prevent the toner image from being offset due to the snowball-like contamination, and maintain the normal fixing operation. In addition, there is no need to provide an oil application device or cleaning device, and the catalyst activates chemical changes only and does not change itself. Problems such as increased costs due to increased complexity and increased maintenance work such as oil replenishment and replacement of the cleaning device can be solved.

According to the third aspect of the present invention, since the pressure roller has the surface layer to which the photocatalyst is added, the pressure roller has a surface layer which decomposes the dirt such as toner or paper powder attached to the surface layer as needed. Self-cleaning is carried out by transferring to transfer paper, etc., so that even if a large number of transfer papers are passed, the surface may be roughened, or a binding organic substance modified with toner, paper powder, or a mixture thereof may adhere. Since it does not peel off, the releasability can be prevented from lowering.

Further, the use of the pressure roller over time can prevent stains from adhering and prevent abnormalities such as paper jam due to winding of the transfer paper and back stain on the transfer paper. In addition, there is no need to provide an oil application device or cleaning device, and the catalyst activates chemical changes only and does not change itself. Problems such as increased costs due to increased complexity and increased maintenance work such as oil replenishment and replacement of the cleaning device can be solved.

According to the fourth aspect of the present invention, when the guide member has a surface layer to which a photocatalyst is added, the guide member decomposes dirt such as toner and paper powder adhering to the surface layer as needed.
Self-cleaning is performed by transferring to transfer paper that passes through it, so even if a large number of transfer papers are passed, the surface may be rough, toner-modified binding organic substances, paper powder, or a mixture thereof. Does not adhere, so that the releasability can be prevented from lowering.

Further, a very small amount of dirt is deposited each time the transfer paper of the guide member is passed, and is prevented from firmly adhering due to the heat of the fixing device. It is possible to prevent the occurrence of a stain defect. In addition, there is no need to provide an oil application device or cleaning device, and the catalyst activates chemical changes only and does not change itself. Problems such as increased costs due to increased complexity and increased maintenance work such as oil replenishment and replacement of the cleaning device can be solved.

[Brief description of the drawings]

FIG. 1 is a side view of a fixing device according to a first embodiment of the present invention.

FIG. 2 is an enlarged partial sectional view of a heating roller of the fixing device shown in FIG.

FIG. 3 is a side view of a fixing device according to a second embodiment of the present invention.

4 is an enlarged partial cross-sectional view of a pressure roller of the fixing device shown in FIG.

FIG. 5 is a side view of a fixing device according to a third embodiment of the present invention.

6 is an enlarged partial cross-sectional view of a guide member of the fixing device shown in FIG.

FIG. 7 is a diagram illustrating a conventional fixing device.

FIG. 8 is an enlarged partial cross-sectional view of a heating roller and a pressure roller of a conventional fixing device.

[Explanation of symbols]

1 Fixing device 2 Heating roller 3 Pressure roller 4 Guide member 8 heat source 10, 20, 30 light source 2a, 3a Layer with photocatalyst added (release layer) 4a Photocatalyst-added layer

Claims (4)

(57) [Claims] A guide for guiding a transfer paper having an unfixed toner image formed thereon between a pair of fixing rollers including a heating roller having a heat source therein and a pressure roller in contact with the heating roller. A fixing device for fixing the toner image by passing the transfer paper guided by the guide member between the pair of fixing rollers, wherein the heat roller or the pressure roller or the guide member At least one of the surfaces is formed with a layer to which a photocatalyst that acts as a catalyst by irradiating light is added, and a light source that emits visible light or ultraviolet light is provided on the surface of this layer. Fixing device. 2. A fixing roller pair comprising a heating roller having a heat source therein and a pressure roller in contact with the heating roller, and a guide for guiding a transfer sheet on which an unfixed toner image is formed between the fixing roller pair. A fixing device that fixes the toner image by passing the transfer paper guided by the guide member between the pair of fixing rollers, wherein the heating roller maintains rigidity and stores heat. When this is formed on the sleeve consists of a release layer for the heat transfer in contact with the toner image, this release layer is added a photocatalyst which acts as a catalyst by exposing light, the heating A fixing device comprising a roller and a light source for irradiating visible light or ultraviolet light on a surface of the roller . 3. A fixing roller pair comprising a heating roller having a heat source therein and a pressure roller in contact with the heating roller, and a guide for guiding a transfer sheet on which an unfixed toner image is formed between the fixing roller pair. A fixing member for fixing the toner image by passing the transfer paper guided by the guide member between the pair of fixing rollers, wherein the pressure roller maintains rigidity and stores heat. A sleeve, an elastic layer formed on the sleeve to form a nip between the heating roller when the heating roller contacts the heating roller, and a release layer formed on the elastic layer and forming a surface layer A photocatalyst that acts as a catalyst by irradiating light to the release layer is added, and a light source that irradiates visible light or ultraviolet light on the surface of the pressure roller is provided. Establishment apparatus. 4. A fixing roller pair comprising a heating roller having a heat source therein and a pressure roller in contact with the heating roller, and a guide for guiding a transfer sheet on which an unfixed toner image is formed between the fixing roller pair. A fixing member for fixing the toner image by passing the transfer paper guided by the guide member between the fixing roller pair, wherein the guide member functions as a catalyst by irradiating light. A fixing device, wherein a layer to which a photocatalyst is added is formed on the surface, and a light source for irradiating visible light or ultraviolet light is provided on the surface of the guide member.