JPH05127555A - Fixing device - Google Patents

Abstract

PURPOSE:To provide a fixing device in which the occurrence of an offset phe nomenon from a recording material to a pressure roller is restrained without excessively applying releasing agent at the time of performing fixing action on both surfaces of the recording material. CONSTITUTION:Applying action is performed to a heating roller 1 by a releasing agent applying means 3A when the recording material P passes through a nip part. The applying action is performed to a pressure roller 2 by a releasing agent applying means 3B when the fixing of a toner image on a side A is completed and the recording material P where an unfixed toner image is formed on a side B passes through the nip part. The applying amount of silicone oil 51 to a rubber layer 6 is set to 0.02-0.10g, expressed by a conversion value per recording material of A4 size, and the applying amount of silicone oil 51 to a rubber layer 9 is set <=0.03g, expressed by the conversion value per recording material of A4 size.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fixing device used in an image forming apparatus such as an electrophotographic copying apparatus and an electrostatic information recording apparatus.

[0002]

2. Description of the Related Art Generally, an image forming process in an image forming apparatus such as an electrophotographic copying apparatus comprises a step of forming a latent image on a photosensitive drum on the basis of an image signal for an original image and a latent image on the photosensitive drum by a developing apparatus. The step of making the image visible, the step of transferring the visible image on the photosensitive drum to the recording material, and the heating roller and the pressure roller heat the unfixed developer image formed on the recording material. And pressing to fix the unfixed developer image as a permanent image on the recording material.

When an image is formed on one surface of the recording material in this image forming process, the above-described steps from the latent image forming step to the fixing step are sequentially performed on one surface of the recording material. A permanent image is formed. On the other hand, when images are formed on both sides of the recording material, the above steps are sequentially performed on one surface of the recording material (hereinafter referred to as “A surface”), and a permanent image is formed on the A surface. Is formed. Next, this recording material is sent to the transfer step again by the conveying means, and the above-mentioned steps are sequentially performed on the other surface of the recording material (hereinafter referred to as "B surface"), and a permanent image is formed on the B surface. The image formation on both sides of the formed recording material is completed.

Images formed on this recording material include black-and-white images and full-color images. Among these, in a fixing step in an image process for forming a full-color image on a recording material, a toner image in which each color of yellow, magenta, cyan, and black is laminated is fixed on the recording material. In this full-color image formation, since the toners of the plural layers forming the toner image are mixed by heating and melting in order to reproduce the color close to the image of the original, sharp melt toner having a low softening point, that is, a low melting point is used. There is.

The fact that the sharp melt toner is melted in a low-viscosity state and the thickness of the toner layer is increased by stacking a plurality of colors accelerates the occurrence of an offset phenomenon in which the toner is transferred to the heating roller. In addition, each fixing temperature range (the temperature range in which proper fixing is possible) differs due to the difference in the meltability caused by the difference in the pigments contained in each color toner. The range is narrowed and the offset phenomenon is likely to occur.

Therefore, in the full-color image forming apparatus using the above-mentioned color toner, a fixing device having means for suppressing the occurrence of the offset phenomenon with respect to the heating roller is used. As shown in FIG. 4, the fixing device includes a heating roller 1, a pressure roller 2 that rotates while being in pressure contact with the heating roller 1, and a heating roller 1 that forms a nip portion for nip-conveying the recording material P, and a heating roller. A release agent applying unit 3 for applying a silicone oil 14 as a release agent to the surface of the roller 1 and a cleaning unit 4 for cleaning the surface of the heating roller 1 are provided.

The heating roller 1 has a hollow cored bar 5 made of aluminum, and the outer peripheral surface of the cored bar 5 is covered with a silicone rubber layer 6. On the other hand, the pressure roller 2 has a hollow cored bar 8 made of aluminum, and the outer peripheral surface of the cored bar 8 is covered with a silicone rubber layer 9 and pressed against the heating roller 1 with a predetermined force.

A halogen heater 7 as a heating source is arranged in the core metal 5 of the heating roller 1, and a halogen heater 11 is arranged in the core metal 8 of the pressure roller 2.

The operation of each halogen heater 7, 11 is controlled by the temperature controller 12. The temperature control device performs on / off control for the operations of the halogen heaters 7 and 11 based on the surface temperature of the pressure roller 2 detected by the thermistor 12a. The surface temperature of the heating roller 1 and the surface temperature of the pressure roller 2 are maintained at predetermined temperatures.

The release agent applying means 3 is made of silicone oil 1
It has a container 13 in which 4 is housed. The silicone oil 14 in the container 13 is pumped up by the upper and lower supply rollers 151, 152 and applied to the silicone rubber layer 6 of the heating roller 1. The amount of silicone oil applied to the silicone oil rubber layer 6 is adjusted by the application amount adjusting blade 10 that is in contact with the upper supply roller 151.

When images are formed on both sides of the recording material P, first, an unfixed toner image T is formed on the A side of the recording material P. At the time of fixing to the unfixed toner image T formed on the surface A of the recording material P, the release agent applying unit 3 is driven and the silicone oil 14 is applied to the surface of the heating roller 1. The recording material P is conveyed by the conveying means and inserted into the nip portion between the heating roller 1 and the pressure roller 2 which are rotating.

While the recording material P is passing through the nip portion, the unfixed toner image T on the recording material P is fused on the recording material P while being mixed with heat and pressure, but the silicone rubber layer of the heating roller 1 is used. 6 and the silicone oil 14 applied to the surface thereof suppress the occurrence of the offset phenomenon. After the recording material P has passed through the nip portion, the permanent image formation on the surface A is completed.

Next, the recording material P on which the permanent image is formed on the A side is sent to the transfer step, and the unfixed toner image is formed on the B side. At the time of fixing to the unfixed toner image on the B side of the recording material P on which the permanent image is formed on the A side, the recording material P contacts the heating roller 1 on the B side and the pressure roller 2 on the A side, and the nip portion Pass through. The unfixed toner image on the B side of the recording material P is melted and mixed, and fixed on the B side as a permanent image, but the toner on which the A side permanent image is formed is
Since the solid phase is again converted to the liquid phase by heat and pressure while passing through the nip portion, the offset phenomenon in which the toner is transferred from the surface A to the pressure roller 2 is likely to occur.

However, the heating roller 1 is applied by the release agent applying means 3.
Since the period in which the silicone oil 14 is applied is the period during which the recording material passes through the nip portion, the silicone oil 14 applied to the heating roller 1 is absorbed by the recording material P. It is not sufficiently supplied, and it is very difficult to suppress the occurrence of the offset phenomenon of the A-side toner on the pressure roller 2 only by the silicone rubber layer 9 of the pressure roller 2.

Therefore, in order to suppress the occurrence of the offset phenomenon of the A-side toner on the pressure roller 2, it is conceivable to provide a release agent applying means for applying the silicone oil 14 to the pressure roller 2. However, silicone oil 14
When the total supply amount to each roller becomes excessive, the consumption amount of the silicone oil 14 increases and the silicone oil 14 stays at the entrance position of the recording material P in the nip portion, and the tip of the recording material P has the silicone oil 14 May be contaminated with.

An object of the present invention is to suppress the occurrence of an offset phenomenon from the surface of the recording material A to the pressure roller without excessively applying a release agent when the fixing operation is performed on both surfaces of the recording material. The object is to provide a fixing device that can perform.

[0017]

According to the first invention of the present application, the object is to provide a release layer on the surface, a heating roller having a heater therein, and a release layer on the surface. A pressure roller that is rotatably pressed against the heating roller, a release agent applying unit for applying a release agent to the surface of the heating roller, and a release agent applied to the surface of the pressure roller. A heating roller and a pressure roller to heat and press the recording material on which the unfixed developer image is formed while being nipped and conveyed, thereby applying the unfixed development to the recording material. In a fixing device that fixes an agent image as a permanent image, when the fixing operation is performed on both sides of the recording material, the release agent applying means for the pressure roller applies the release agent to the surface of the pressure roller. It is achieved by

According to the second invention of the present application, the above-mentioned object is to form a release layer on the surface and a heating roller having a heater therein, and a release layer on the surface so that the heating roller can rotate. A pressure roller in pressure contact, a heating roller release agent applying means for applying a release agent to the surface of the heating roller, and a pressure roller applying means for applying a release agent to the surface of the pressure roller. And heating and pressurizing the recording material on which the unfixed developer image is formed by the heating roller and the pressure roller while nip-conveying the recording material, the unfixed developer image is formed as a permanent image on the recording material. In the fixing device for fixing, when the fixing operation is performed on both sides of the recording material, the amount of the release agent applied to the surface of the heating roller by the heating roller release agent application means Q1 and the release for the pressure roller. The above addition by the agent applying means The amount of release agent applied to the surface of the pressure roller Q2 and the amount of release agent applied are satisfied by satisfying the relational expression of Q1 ≧ Q2.

[0019]

In the fixing device according to the first aspect of the present invention, when the fixing operation is performed on both sides of the recording material, the release agent applying means for the pressure roller applies the release agent to the surface of the pressure roller. Apply.

Recording material P having a permanent image formed on side A
At the time of fixing to the unfixed developer image on the B side, the release agent is applied to the surface of the heating roller by the release agent application means for the heating roller, and the release agent is applied by the release agent application means for the pressure roller. Is applied to the surface of the pressure roller. The recording material is nipped and conveyed with the B side in contact with the heating roller and the A side in contact with the pressure roller, and the unfixed developer image on the B side of the recording material is B.
It is fixed on the surface as a permanent image. On the other hand, the developer forming the permanent image on the surface A is converted from the solid phase to the liquid phase again while the recording material is conveyed under pressure, but is applied to the release layer of the pressure roller and the surface thereof. The releasing agent prevents transfer of the developer from the surface A to the surface of the pressure roller,
The occurrence of the offset phenomenon is suppressed.

Since the applying operation of the releasing agent applying means for the pressure roller is carried out at the time of fixing the unfixed toner image on the B side, the amounts of the releasing agent applied to the heating roller and the pressure roller do not become excessive. ..

In the fixing device according to the second aspect of the present invention, when the fixing operation is performed on both sides of the recording material, the amount of the releasing agent applied to the surface of the heating roller by the releasing agent applying means for the heating roller is Q1. The amount Q2 of the release agent applied to the surface of the pressure roller by the release agent applying means for the pressure roller is Q1 ≧ Q
By satisfying the relational expression (2), the coating amount of the release agent on the heating roller and the pressure roller does not become excessive, and
The transfer of the developer from the surface to the surface of the pressure roller is prevented, and the occurrence of the offset phenomenon is suppressed.

[0023]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of the fixing device of the first invention of the present application.

As shown in FIG. 1, the fixing device used in the full-color image forming apparatus includes a heating roller 1 and a pressure roller 2 which is rotated while being in pressure contact with the heating roller 1.
Release agent applying means 3A for applying a release agent to the heating roller 1
And a release agent applying means 3 for applying a release agent to the pressure roller 2.
B and the heating roller 1 with the web-shaped cleaning member 4d.
And a cleaning means 4B for cleaning the pressure roller 2 with a web-shaped cleaning member 4d.

The heating roller 1 has a hollow cored bar 5 made of aluminum, and the outer peripheral surface of the cored bar 5 is covered with a rubber layer 6. The rubber layer 6 is dimethyl silicone rubber (Toray Industries, Inc.)
The rubber layer 6 has a thickness of 3 mm. The outer diameter of the heating roller 1 is 40 mm. In addition,
The heating roller 1 is a methylphenyl silicone oil (KF54-450c manufactured by Shin-Etsu Chemical Co., Ltd.) heated to 120 ° C. in order to further improve the releasability of the rubber layer 6.
s) The rubber layer 6 is dipped in a bath to impregnate it with methylphenyl silicone oil.

The pressure roller 2 has a hollow cored bar 8 made of aluminum, and the outer peripheral surface of the cored bar 8 is covered with a rubber layer 9. Similar to the rubber layer 6 of the heating roller 1, this rubber layer 9 is made of dimethyl silicone rubber, and the thickness dimension of the rubber layer 9 is 1 mm. In addition, the heating roller 1 is provided on the rubber layer 9.
Similarly, is impregnated with methylphenyl silicone oil. The outer diameter of the pressure roller 2 is 40 mm, and it cooperates with the heating roller 1 to form a nip portion for conveying the recording material P under pressure.

A halogen heater 7 as a heating source is arranged in the core metal 5 of the heating roller 1, and a halogen heater 11 is arranged in the core metal 8 of the pressure roller 2.

The operation of each halogen heater 7, 11 is controlled by the temperature controller 12. The temperature control device 12 performs on / off control for the operation of each halogen heater 7, 11 based on the surface temperature of the pressure roller 2 detected by the thermistor 12a. Surface temperature of heating roller 1 and pressure roller 2
The surface temperature of is maintained at around 170 ° C. during fixing.

Each of the releasing agent applying means 3A, 3B has a container 13 containing a silicone oil 51 as a releasing agent. Silicone oil 51 is methylphenyl silicone oil (KF54 manufactured by Shin-Etsu Chemical Co., Ltd., viscosity 450c
s).

The silicone oil 51 in the container 13 is pumped up by the upper and lower supply rollers 151, 152. In the release agent applying means 3A, the silicone oil 51 is applied to the rubber layer 6 of the heating roller 1. The application amount of the silicone oil 51 on the rubber layer 6 is adjusted by the application amount adjusting blade 10 that is in contact with the upper supply roller 151. The amount of silicone oil 51 applied to the rubber layer 6 is 0.02 to 0.10 g, and preferably 0.03 g, as a converted value per A4 recording material. The amount of oil applied per sheet of recording material was obtained by measuring the weight of 50 sheets of the same recording material passed through the fixing device without applying oil.
It was determined by subtracting the total weight of 50 sheets passed with oil applied and dividing this value by 50.

On the other hand, in the release agent applying means 3B, the silicone oil 51 is applied to the rubber layer 9 of the pressure roller 2. As described above, the toner image T on the surface A of the recording material P is
Is fixed once, the amount of silicone oil 51 applied to the rubber layer 9 is 0.
It can be 03 g or less.

The coating operation of the release agent coating means 3A to the heating roller 1 is performed when the recording material P passes through the nip portion, and the silicone oil 51 substantially corresponds to the portion of the heating roller 1 that contacts the recording material P. Applied to the area. In addition,
In the present embodiment, the supply operation of the silicone oil 51 is controlled by ON-OFF controlling the rotational drive of the supply roller 151 that is in contact with the surface of the heating roller 1. It is also possible to control the coating operation by controlling the contact / separation operation of the roller 151.

On the other hand, in the applying operation of the release agent applying means 3B to the pressure roller 2, the fixing of the toner image on the A side is completed, and the recording material P on which the unfixed toner image is formed on the B side. The coating operation is performed when the recording material P passes through the nip portion and the unfixed toner image is formed only on the surface A. The coating operation is not performed when the recording material P passes through the nip portion. Also in this case, the silicone oil 51 is applied to a region of the pressure roller 2 substantially corresponding to the contact portion with the recording material P, and the control of the applying operation is performed by the same method as the release agent applying means 3A.

Each of the cleaning means 4A, 4B has a web-like cleaning member 4d having one surface plated with nickel. The cleaning member 4d of the cleaning means 4A is sent from the sending shaft 4a to the winding shaft 4c via the pressing roller 4b while one surface of the cleaning member 4d is in contact with the surface of the heating roller 1.

Similarly, the cleaning member 4d of the cleaning means 4B is fed from the delivery shaft 4a to the winding shaft 4c via the pressing roller 4b while one surface of the cleaning member 4d is in contact with the surface of the pressure roller 2.

Next, the fixing operation on the recording material on which images are formed on both sides will be described.

First, after the unfixed toner image is formed on the A surface of the recording material P, it is sent to a fixing device by a conveying means (not shown), and the unfixed toner image T formed on the A surface is transferred. Fixing takes place.

More specifically, at the time of fixing the unfixed toner image T on the surface A, the release agent applying means 3A is driven and the silicone oil 51 is applied to the surface of the heating roller 1. This recording material P is conveyed in the direction of arrow a by the conveying means and inserted into the nip portion between the heating roller 1 and the pressure roller 2 which are rotating.

The recording material P passes through the nip portion while the surface A is in contact with the silicone oil application area of the heating roller 1, whereby the unfixed toner image T on the recording material P is recorded while being mixed by heat and pressure. It is fused on the material P. At this time, the rubber layer 6 of the heating roller 1 and the silicone oil 51 applied to the surface thereof prevent the toner forming the toner image T from transferring to the surface of the heating roller 1 and suppress the occurrence of the offset phenomenon.

The recording material P on which the permanent image is formed on the surface A in this manner is conveyed again to the transfer step by the conveying means. After the latent image corresponding to the B side of the recording material P is visualized as a toner image, the toner image on the photosensitive drum is transferred to the B side of the recording material P in a transfer process and sent to the fixing device.

Recording material P having a permanent image formed on side A
When the unfixed toner image on the B side is fixed, the release agent applying units 3A and 3B are driven substantially at the same time. Here, since the coating operation of the release agent coating unit 3B is performed only when the unfixed toner image on the B side is fixed, the silicone oil coating amount of the heating roller 1 and the pressure roller 2 does not become excessive, so the nip The silicone oil 51 does not stay near the entrance of the section, and the tip of the recording material P is not contaminated by the silicone oil 51 when the recording material P enters the nip portion.

The recording material P passes through the nip portion while the surface B is in contact with the silicone oil application area of the heating roller 1 and the surface A is in contact with the silicone oil application area of the pressure roller 2.
The unfixed toner image on the B side is melted and mixed, and fixed on the B side of the recording material P as a permanent image. Similarly, the toner on which the permanent image on the surface A is formed is again phase-converted from the solid phase to the liquid phase by heat and pressure while passing through the nip portion of the recording material P. The silicone oil 51 applied to the surface prevents transfer of the toner to the surface of the pressure roller 2 and suppresses the occurrence of the offset phenomenon.

In this embodiment, the release agent applying means 3B is used.
The execution timing of the application operation is set so that the application operation of No. 3 is performed only at the time of fixing to the unfixed toner image on the B side. By performing the operation with a smaller amount of silicone oil applied, excessive application of silicone oil can be eliminated. For example, A4 by the release agent applying means 3B
The amount of silicone oil applied per recording material is 0.00
It can be reduced to 5g.

Next, another embodiment of the fixing device of the first invention of the present application will be described with reference to FIG.

As shown in FIG. 2, this fixing device has a heating roller 1 having a rubber layer 6 formed on the surface thereof and a rubber layer 9 formed on the surface thereof, and is rotated while being pressed against the heating roller 1. The pressure roller 2, a release agent applying means 3A for applying a release agent to the heating roller 1, a release agent applying means 3B for applying a release agent to the pressure roller 2, and a web-like cleaning member 4d for heating. A cleaning unit 4A for cleaning the roller 1 and a cleaning unit 4B for cleaning the pressure roller 2 with a web-shaped cleaning member 4d are provided.

Each of the release agent applying means 3A, 3B has a container 13 in which a silicone oil 51 as a release agent is stored. The silicone oil 51 in the container 13 is absorbed into the oil absorber 153 by its osmotic pressure.
The oil absorber 153 is made of a heat-resistant member such as Fluoropore (trade name) and felt, and the member is supported by the support plate 154.

In the release agent applying means 3A, the oil absorber 1 is used.
The silicone oil 51 absorbed by the oil absorber 153 is applied to the rubber layer 6 of the heating roller 1 by bringing 53 into contact with the heating roller 1. The oil absorber 153 contacts the heating roller 1 before the recording material P enters the nip portion, and is separated from the heating roller 1 after the recording material P passes through the nip portion. The amount of silicone oil applied to the heating roller 1 is determined by the pressing force of the oil absorber 153 against the heating roller 1, and is 0.02 as a converted value per A4 recording material.
It is set to 0.10 g.

On the other hand, in the release agent applying means 3B, the silicone oil 51 is applied to the rubber layer 9 of the pressure roller 2. The release agent applying means 3B is driven at the time of fixing to the unfixed toner image on the B side of the recording material P on which the permanent image is formed on the A side. The oil absorber 153 contacts the pressure roller 2 before the recording material P enters the nip portion, and is separated from the pressure roller 2 after passing through the nip portion. The amount of silicone oil applied to the pressure roller 2 is set to 0.005 to 0.10 g as a converted value per A4 recording material.

In this embodiment also, the release agent applying means 3B is used.
The execution timing of the application operation is set so that the application operation of No. 3 is performed only at the time of fixing to the unfixed toner image on the B side. By performing the operation with a smaller amount of silicone oil applied, excessive application of silicone oil can be eliminated.

Next, still another embodiment of the fixing device according to the first aspect of the present invention will be described with reference to FIG.

As shown in FIG. 3, this fixing device cleans the heating roller 1 with a heating roller 1, a pressure roller 2 rotated while being in pressure contact with the heating roller 1, and a web-shaped cleaning member 4d. Cleaning means 4A
And a cleaning means 4B for cleaning the pressure roller 2 with the web-shaped cleaning member 4d.

Each of the cleaning means 4A and 4B has a web-shaped cleaning member 52. The cleaning member 52 is impregnated with the silicone oil 51 in advance.

The cleaning member 52 of the cleaning means 4A is fed from the feeding shaft 4a to the winding shaft 4c via the pressing roller 4b while one surface of the cleaning member 52 is in contact with the surface of the heating roller 1, and the cleaning member 52 is fed. By the operation, cleaning of the heating roller 1 and application of silicone oil to the heating roller 1 are simultaneously performed. The amount of silicone oil 51 applied to the heating roller 1 is determined by the pressing force of the cleaning member 52 against the heating roller 1 and the feeding speed. It is set within a range of 0.02 to 0.10 g as a converted value per A4 recording material.

The cleaning means 4A is moved to a position where the cleaning member 52 and the heating roller 1 can contact each other before the recording material P enters the nip portion, and the feeding operation of the cleaning member 52 is started after the movement. After a lapse of a predetermined time from the passage of the recording material through the nip portion, the feeding operation of the cleaning member 52 is stopped, and the cleaning unit 4A is moved to a position where the cleaning member 52 is separated from the heating roller 1.

On the other hand, the cleaning member 52 of the cleaning means 4B is fed from the feeding shaft 4a to the winding shaft 4c via the pressing roller 4b while one surface of the cleaning member 52 is in contact with the surface of the pressure roller 2. By the feeding operation of the cleaning member 52, cleaning of the surface of the pressure roller 2 and application of silicon oil to the pressure roller 2 are simultaneously performed. The amount of silicone oil 51 applied to the pressure roller 2 is determined by the pressing force of the cleaning member 52 against the pressure roller 2 and the feeding speed, like the amount of silicone oil 51 applied to the heating roller 1. The conversion value per A4 recording material is set within the range of 0.005 to 0.10 g.

The cleaning means 4B has a permanent image formed on the surface A and an unfixed toner image formed on the surface B before the recording material P enters the nip portion. Are moved to a position where they can come into contact with each other, and the feeding operation of the cleaning member 52 is started after the movement. After a predetermined time has passed since the recording material passed through the nip portion, the feeding operation of the cleaning member 52 is stopped, and the cleaning unit 4B is moved to a position where the cleaning member 52 is separated from the pressure roller 2.

In this embodiment, the cleaning means 4
Although the timing of applying operation is set so that the feeding operation of the B cleaning member 52 is performed at the time of fixing to the unfixed toner image on the B side, instead of this, the cleaning unit 4 is used.
Excessive application of silicone oil can be eliminated by performing the feeding operation of the cleaning member 52 with an even smaller amount of silicone oil applied without limiting the operation timing of B.

[0059]

As described above, according to the fixing device of the first aspect of the present invention, when the fixing operation is performed on both sides of the recording material, the application of the release agent applying means for the pressure roller is performed. By performing the operation, it is possible to suppress the occurrence of an offset phenomenon in which the developer is transferred from the recording material to the pressure roller without excessively applying a release agent to the heating roller and the pressure roller. ..

According to the fixing device of the second aspect of the present invention, when the fixing operation is performed on both sides of the recording material, the amount of the releasing agent applied to the surface of the heating roller by the releasing agent applying means for the heating roller. Q1 and the amount of release agent applied to the surface of the pressure roller by the release agent applying means for the pressure roller Q2 are Q1.
By satisfying the relational expression ≧ Q2, it is possible to suppress the occurrence of the offset phenomenon in which the developer is transferred from the recording material to the pressure roller without excessively applying the release agent to the heating roller and the pressure roller. can do.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an embodiment of a fixing device of the first invention of the present application.

FIG. 2 is a configuration diagram showing another embodiment of the fixing device of the first invention of the present application.

FIG. 3 is a configuration diagram showing still another embodiment of the fixing device of the first invention of the present application.

FIG. 4 is a configuration diagram showing a conventional fixing device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Heating roller 2 Pressure roller 3A, 3B Release agent applying means 4A, 4B Cleaning means 6,9 Rubber layer 10 Application amount adjusting blade 51 Silicone oil 52 Cleaning member 151, 152 Supply roller 153 Oil supply body

Claims (2)

[Claims] 1. A heating roller having a release layer formed on its surface and having a heater inside, and a pressure roller having a release layer formed on its surface and rotatably pressed against said heating roller.
The heating roller includes a releasing agent applying unit for applying a releasing agent to the surface of the heating roller, and a pressing roller applying unit for applying a releasing agent to the surface of the pressing roller. A fixing device for fixing the unfixed developer image as a permanent image on the recording material by heating and pressurizing the recording material on which the unfixed developer image is formed while being nipped and conveyed by a pressure roller. A fixing device, wherein the release agent applying means for the pressure roller applies the release agent to the surface of the pressure roller when the fixing operation is performed on both surfaces of the pressure roller. 2. A heating roller having a release layer formed on its surface and having a heater inside, and a pressure roller having a release layer formed on its surface and rotatably pressed against said heating roller.
The heating roller includes a releasing agent applying unit for applying a releasing agent to the surface of the heating roller, and a pressing roller applying unit for applying a releasing agent to the surface of the pressing roller. A fixing device for fixing the unfixed developer image as a permanent image on the recording material by heating and pressurizing the recording material on which the unfixed developer image is formed while being nipped and conveyed by a pressure roller. When the fixing operation is performed on both surfaces of the heating roller, the amount of the releasing agent applied to the surface of the heating roller by the heating roller releasing agent applying means Q1 and the amount of the pressing roller applied by the pressing roller releasing agent applying means. A fixing device characterized in that the amount of release agent applied to the surface Q2 satisfies the relational expression of Q1 ≧ Q2.