JP2003316197A - Fixing device and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of selecting the most suitable arrangement place of a non-contacting separation means (a gap between the front end part of the separation means and each member) in order to effectively prevent trouble that a recording material is wound around a fixing member and a pressure member. <P>SOLUTION: In a fixing device which has a fixing member 15 and a pressure member 16 and allows the recording material to pass a nip part N between both members to fix a toner image on the recording material by actions of heat and pressure, the surface hardness of the pressure member is made higher than that of the fixing member to form a projecting nip part, and a separation means 19 for separating the recording material ejected from the projecting nip part from the surface of the pressure member is made to project between the surface of the pressure member and the front end of the recording material without coming into contact with them, and the front end of the separation means is placed on a line L connecting the center of rotation of the pressure member and the front end of the recording material at the point when the rear end of a blank part on the front end side of the recording material reaches an exit of the projecting nip part. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a copying machine, a printer,
The present invention relates to an improvement of a fixing device equipped in an electrophotographic image forming apparatus such as a facsimile machine, and particularly to a nip portion of both members, which includes a fixing member that is heated and rotates, and a pressure member that rotates while being pressed against the fixing member. The present invention relates to a fixing device for fixing a toner image passing through a recording material by the action of heat and pressure, and an image forming apparatus including the fixing device.

[0002]

2. Description of the Related Art Copiers, printers, facsimile machines,
Alternatively, an electrophotographic image forming apparatus such as a multifunction peripheral having at least these two functions transfers a toner image formed on a photoconductor onto a recording material and then fixes the image by a fixing device to form an image. Is going. The fixing device includes a fixing member that is rotated by being heated by a heating element and a pressure member that is rotated while being in pressure contact with the peripheral surface of the fixing member, and heats the toner image on the recording material passing through the nip portion of both members. It is a means of fixing by the action of pressure. The fixing member is composed of, for example, a fixing roller or an endless fixing belt that is wound around a fixing roller that also serves as a guide member and rotates. The pressure member is composed of, for example, a pressure roller that is pressed against the fixing member to rotate. In any type of fixing device, the toner carried on the recording material is melted in the nip portion when passing through the nip portion formed by the fixing member and the pressure member, so that the molten toner acts as an adhesive. However, the recording material discharged from the nip portion may wind around the surface of the fixing member without separating from the surface. Further, in a color image forming apparatus that forms a full-color image, a plurality of toner images of different colors are superposed and transferred on a recording material, and the superposed toner images are fixed by a fixing device. The toner is melted, which increases the adhesive force of the toner and makes the recording material particularly easy to wind around the fixing member.

In order to solve such a problem, conventionally, a separating means composed of a separating claw, a separating plate, a separating sheet and the like is brought into contact with the surface of the fixing roller to separate the recording material from the nip portion. The recording material is forcibly separated from the surface of the fixing roller to prevent the recording material from wrapping around the surface of the fixing member. However, when the separating means is always brought into contact with the fixing roller as described above, the surface of the fixing roller may be damaged by the separating means. When the surface of the fixing roller is scratched, a mark corresponding to the scratch is formed on the toner image passing through the nip portion, and the image quality of the toner image after fixing is deteriorated. Therefore, there has been proposed a fixing device in which the tip of the separating means is arranged apart from the surface of the fixing roller. That is, FIG. 10 is an enlarged cross-sectional view of a main part of a conventional fixing device. The fixing device 100 shown here is similar to the fixing roller 10 in FIG.
1 and a pressure member configured as a pressure roller 102 that is in pressure contact with the fixing roller 101, and these rollers 101, 102 are in pressure contact with each other at their peripheral surfaces, thereby forming a nip portion. N is formed. The fixing roller 101 and the pressure roller 102 are formed in a hollow cylindrical shape. The fixing roller 101 rotates clockwise, and the pressure roller 102 rotates counterclockwise. Inside both rollers 101 and 102, a heating means 10 such as a halogen heater controlled by a temperature control means (not shown).
The nip portion N formed by pressing the rollers 3 and 104 is heated to an appropriate temperature suitable for fixing by ON / OFF control of energization to the heating unit. The recording material P carrying the unfixed toner image T has a nip portion N as shown by an arrow A when the toner image T is directed to the fixing roller 101.
The toner image T is fixed on the recording material P by heat and pressure at this time.

In this example, the hardness of the outer peripheral surface of the pressure roller 102 is set higher than that of the outer peripheral surface of the fixing roller 101. A convex nip portion N having a dented surface is formed. In this way, when the recording material P passes through the convex nip portion, the leading end portion of the recording material is discharged in the tangential direction of the pressure roller at the nip outlet, that is, in the direction away from the peripheral surface of the fixing roller 101. Even when toner is present on the upper surface of the recording material P, there is less risk that the upper surface of the recording material will be attracted to the peripheral surface of the fixing roller 101 and wrapped around. Even if the fixing roller 101 is wrapped around the fixing roller 101,
By arranging the blade-shaped separating means 110 with a gap (gap) G on the peripheral surface, the recording material to be wrapped can be peeled off. When fixing the recording material P having a toner image also on the lower surface side in contact with the pressure roller, the recording material having toner on both surfaces is heated and pressed at the nip portion, and therefore the lower surface side The toner is re-melted and adheres to the peripheral surface of the pressure roller 102, which causes the recording material to wind. In order to prevent such wrapping around the pressure roller 102, the tip of the pressure roller 1 as shown in FIG.
The separation claw 111 elastically pressed against the peripheral surface of 02 is arranged. That is, the separation claw 111 is rotatably supported about the rotation shaft 111a, and is elastically biased in the pressure contact direction by the spring 112. The recording material P, which is attracted to the circumferential surface of the pressure roller 102 and is about to rotate, is separated by the separation claw 111
The sheet is peeled off and discharged on the separation guide 113.

However, since the tip of the separation claw 111 is always in contact with the surface of the pressure roller 102, the surface of the pressure roller 102 may be scratched by the separation claw 111. However, when a toner containing oil is used, the oil in the toner adheres to the pressure roller and acts as a lubricant, and scratches can be prevented to some extent, but there is a limit to that. In addition, since the oilless type toner has been widely used recently, the lubricating effect of the oil contained in the toner cannot be expected. Therefore, in the contact-type separating means, scratches are formed on the pressure roller. When the surface of the pressure roller is scratched, a mark corresponding to the scratch is formed on the toner image passing through the nip portion, and the image quality of the toner image after fixing is deteriorated. On the other hand, the hardness of the peripheral surface of the fixing roller 101 is made larger than the hardness of the peripheral surface of the pressure roller 102 to form a concave nip portion, and the tip end portion is not in contact with the peripheral surface of the pressure roller. It is also conceivable to arrange the separating means which are arranged close to each other. However, when a non-contact type separating means is provided on the pressure roller side, it is not easy to set an appropriate value for the gap between the tip of the separating means and the pressure roller, and it varies depending on the model. However, the appropriate value was not constant depending on the thickness of the recording material P passing through and the difference in strength of the waist. For this reason, the proper value of the gap can only be obtained by trial and error for each model, and even if it is once set to an appropriate value, it may become entangled depending on the material of the recording material, the difference in wall thickness, and the influence of static electricity. In many cases, it could not be effectively prevented. Further, when a phenomenon (wrapping) occurs in which the toner image keeps contacting the roller at a position past the nip portion, the toner image in that portion is heated for a long time. A gloss difference is generated between the toner image portion and the toner image portion located behind the peeling position. That is, the gloss increases in the wound portion where the heating time becomes long, and uneven gloss occurs between the wound portion and another image portion that has passed through the nip portion without causing the winding. This is a problem particularly occurring in an image forming apparatus using color toner.

As described above, conventionally, the nip portion has a convex shape,
By selecting any one of the concave shapes, the recording material may be prevented from being wound around one of the rollers, while the non-contact separating means may be used to prevent the recording material from being wound around the other roller. However, even if the non-contact separating means is arranged, a method for properly setting the gap between the corresponding rollers has not been clarified, and the only way to obtain the proper gap by repeating the experiment. . However, even if the proper interval is set, the situation in which the wrapping cannot be prevented occurs depending on the conditions such as the thickness of the recording material to be passed, the strength of the waist, the presence or absence of static electricity. That is, in FIG. 10, when the tip portion of the non-contact type separating means is provided close to the peripheral surface of the pressure roller (the roller on the side where the tip of the recording material discharged from the convex nip portion approaches), the separating means is provided. Since the gap between the tip and the peripheral surface of the pressure roller is narrowed, the work for setting the gap becomes difficult, the assembly and the accuracy of parts are inevitably improved, and the cost is increased. On the other hand, when the tip of the separating device is provided in the direction away from the nip portion, and the adhesive force between the molten toner on the recording material and the surface of the pressure roller is larger than the rigidity of the recording material, the tip of the toner image on the recording material is It is conveyed so as to wind around the pressure roller and separated by the separating means. As a result, the glossiness of the leading end portion of the image becomes high only in the portion where the recording material is wound around the pressure roller, and uneven glossiness occurs between other portions. In the above description, the roller-shaped fixing member and the pressure member have been described, but the same problem occurs when either one of the members is an endless belt.

[0007]

As described above, there is conventionally known a technique for preventing the recording material discharged from the nip portion from winding around the fixing member and the pressure member by using the non-contact type separating means. However, there is no established method to know the proper distance between the tip of the separating means and the fixing member, regardless of the model or the material and thickness of the recording material to be passed.
It is not only necessary to repeat the trial and error for each model to adjust the interval, but even if the interval G is set once, there are many cases where wrapping cannot be sufficiently prevented depending on the type of recording material to be passed. It was Especially in the case of color toner, when the toner image once adsorbed on the member due to winding is peeled off by the separating means, the gloss of that portion increases, so that uneven gloss occurs between other toner image portions. It was easy to do. Therefore, up to now, no method has been known to determine an appropriate interval that can always stably prevent wrapping regardless of changes in conditions such as a model and a recording material used.
Further, the proper value of the gap when the non-contact type separating means is simultaneously arranged for the fixing member and the pressure member has not been known so far. The present invention has been made in view of the above, and a first object of the present invention is regardless of conditions such as whether or not oilless toner is used, or how to set the shape of a nip portion. In order to effectively prevent the trouble that the recording material wraps around the surface of the fixing member and the pressure member regardless of the single-sided or double-sided fixing mode, the most suitable arrangement of the non-contact type separating means. It is to provide a method of selecting a place (a space between the tip of the separating means and each member). A second object of the present invention is to fix a fixing member or a pressing member, which prevents the problem that the recording material wraps around and the image gloss unevenness occurs depending on the position and the distance between the fixing member and the pressing member. To provide a device. A third object of the present invention is to provide an image forming apparatus including the above fixing device.

[0008]

In order to solve the above-mentioned problems, the invention of claim 1 includes a rotatable fixing member which is heated by a heat generating means, and a pressure member which is rotated in pressure contact with the fixing member. A fixing device for passing a recording material carrying a toner image through a nip portion between a fixing member and a pressure member, and fixing the toner image on the recording material by the action of heat and pressure. A separating means for forming a convex nip portion by setting the surface hardness higher than the surface hardness of the fixing member, and separating the recording material discharged from the convex nip portion from the pressure member surface, The surface of the pressure member and the leading edge of the recording material are projected in a non-contact state, and when the trailing edge of the leading edge margin of the recording material reaches the exit of the convex nip portion, The tip of the separating means is positioned on the straight line connecting the center of rotation of the pressure member. Characterized by being configured to. When the oilless toner is used, the lubricating action of the surface of each member by the oil component contained in the toner cannot be expected, and therefore the contact type separating means cannot be arranged. Therefore, it is necessary to dispose the tips of the non-contact type separating means on the surfaces of the fixing member and the pressing member at a predetermined positional relationship and at a predetermined interval. At this time, by making the hardness of one member harder than that of the other member, a convex or concave nip portion is formed to prevent the leading edge of the recording material discharged from the nip portion from winding around a specific member. A configuration that regulates the direction is also used. In addition, when an image is formed on both sides of the recording material, the recording material may be wrapped around the other member, so that the non-contact separation means may be arranged to face the other member. is there. However, it is difficult to set the positional relationship between the separating means and each member, and the distance appropriately, and until now, the proper position and the proper value were only found by repeated trial and error. It is necessary to perform setting work individually, and fixing or winding around the pressure member (adsorption by molten toner) occurs due to changes in various conditions such as the quality of the recording material that is passed, the thickness of the recording material, and the strength of the waist. When peeled by the separating means, uneven gloss was generated. In the present invention, the shape of the nip portion is set to a shape that guides the leading end of the recording material in the direction of separating from the fixing member to prevent wrapping around the fixing member, while preventing wrapping around the pressure member side. It is realized by contact-type separation means. Moreover, since the arrangement position of the tip of the separating means is defined in relation to the width of the blank area (non-toner image area) located within a predetermined width from the tip of the recording material, the distance between the tip of the separating means and the pressing member is defined. Is not too narrow or too wide, and even if a recording material having a weak stiffness is used, it is possible to prevent the occurrence of winding around the pressure member. Further, according to the present invention, since the presence of the blank portion is used to prevent the toner image portion on the recording material from being attracted to and wound around each member,
In image formation using color toner, the toner image part of the recording material is once adsorbed on one of the members, once wrapped around and then peeled off, resulting in uneven gloss from other parts. Is also prevented.

According to a second aspect of the present invention, in the first aspect, the distance (G1) between the tip of the separating means and the surface of the pressing member on the straight line is 0 <G1 <W / sin θ1) -R.
1 (W; width of the margin portion on the leading end side of the recording material in the transport direction, θ1;
It is characterized in that the rotation angle of the pressure member is within a range of an angle between the exit of the nip portion and the tip of the recording material, R1; radius of the pressure member. Although the separating means is arranged apart from the surface of the pressing member, the gap G1 is set to an appropriate value as described above, and as a result, the position of the separating means tip is closer to the nip portion than the recording material tip. It is set in the position of. For this reason, even if the tip of the recording material tries to move to the pressing member side, it is always caught by the separating means located on the moving path, so that the recording material P pulled to the pressing member side by the adhesive force of the toner is pressed. It is possible to prevent a problem that the toner adheres to the surface of the member and enters the gap G1 and winds around the surface of the pressing member.

According to a third aspect of the present invention, a recording material carrying a toner image is fixed to a fixing member, which includes a rotatable fixing member heated by a heat generating means and a pressure member rotating in pressure contact with the fixing member. In a fixing device that allows a toner image to be fixed on a recording material by the action of heat and pressure by passing through a nip portion between the pressure member and the pressure member, the surface hardness of the pressure member is set to be lower than the surface hardness of the fixing member. Forming a concave nip portion, and separating means for separating the recording material discharged from the concave nip portion from the fixing member surface is projected in a non-contact state between the fixing member surface and the recording material front end. In addition, the tip of the separating means is positioned on the straight line connecting the tip of the recording material and the center of rotation of the fixing member at the time when the trailing edge of the margin on the tip side of the recording material reaches the outlet of the concave nip portion. It is characterized in that it is configured in. In the present invention, the shape of the nip portion is set to a shape that guides the leading end of the recording material in the direction of separating from the pressure member to prevent wrapping around the pressure member while preventing wrapping around the fixing member side. It is realized by non-contact type separation means. Moreover, in relation to the width of the margin portion (non-toner image portion) located within a predetermined width range from the leading edge of the recording material,
Since the arrangement position of the tip of the separating means is regulated, the distance between the tip of the separating means and the fixing member is not too narrow or too wide, and even if a recording material having a weak stiffness is used, the occurrence of wrapping around the pressure member is caused. Can be prevented. Further, according to the present invention, the existence of the blank portion is used to prevent the toner image portion on the recording material from being attracted to and wound around each member. Therefore, the image formation using the color toner is performed. In the above, the unevenness in gloss between other members due to the increase in gloss caused by the toner image portion of the recording material once adsorbed on any member, wrapped around, and then peeled off is also prevented.

According to a fourth aspect of the present invention, in the third aspect, the distance (G2) between the tip of the separating means and the surface of the fixing member on the straight line is 0 <G2 <(W / sin θ2)-
R2 (W; width of the margin on the leading end side of the recording material in the conveying direction, θ
2; the angle between the exit of the nip portion and the tip of the recording material, R2; radius of the fixing member) with respect to the center of rotation of the fixing member. Although the separating means is disposed apart from the surface of the fixing member, the gap G2 is set to an appropriate value, and as a result, the position of the leading end of the separating means enters the position closer to the nip portion than the leading end of the recording material. It is set.
For this reason, even if the leading edge of the recording material tries to move to the fixing member side, it is always caught by the separating means located on the moving path, so that the recording material P pulled to the fixing member side by the adhesive force of the toner is the surface of the fixing member. G1 while still attached to
It is possible to prevent a problem that it gets inside and is wound around the surface of the fixing member.

According to a fifth aspect of the present invention, a recording material carrying a toner image is fixed, comprising a rotatable fixing member heated by a heat generating means and a pressure member rotating in pressure contact with the fixing member. In a fixing device that allows the toner image to be fixed to a recording material by the action of heat and pressure by passing through a nip portion between a member and a pressure member, the surface hardness of the pressure member is approximately equal to the surface hardness of the fixing member. To form a flat nip portion, and separating means for separating the recording material discharged from the flat nip portion from the surface of the fixing member and the surface of the pressing member, respectively, the tip of the recording material and the fixing member. One is projected in a non-contact state between the surface of the member and the tip of the recording material and the pressing member, and the trailing edge of the margin on the leading end side of the recording material is the flat nip portion. With the tip of the recording material when it reaches the exit And centers of rotation and pressure member of the fixing member respectively connecting onto each straight line, the leading end of each separating means is characterized by being configured to be positioned. In the present invention, the shape of the nip portion is made flat, and the leading end of the recording material is set so as to be guided in the discharge direction from both members via a path at an equal distance to prevent wrapping around both members while The non-contact separation means provided on each member realizes the prevention of wrapping around. In addition, since the arrangement position of the separation means tip portion with respect to each member is defined in relation to the width of the margin portion (non-toner image portion) located within a predetermined width from the recording material tip end, the separation means tip end and each member are The interval is not too narrow or too wide, and even if a recording material having a weak stiffness is used, it is possible to prevent the occurrence of winding around each member. Further, according to the present invention, the existence of the blank portion is used to prevent the toner image portion on the recording material from being attracted to and wound around each member. Therefore, the image formation using the color toner is performed. In the above, the unevenness in gloss between other members due to the increase in gloss caused by the toner image portion of the recording material once adsorbed on any member, wrapped around, and then peeled off is also prevented. When the flat nip portion is used as described above, the recording material is ejected straight, and therefore when there is a large amount of toner, it may be adsorbed to one of the members. By using the separating means arranged at the proper position, the margin is used to guide in the direction that does not cause wrapping,
Even if the amount of toner is large, it does not cause adsorption or winding.

According to a sixth aspect of the present invention, in the fifth aspect, the distance (G3) between the tip of the separating means and the surface of the fixing member on the one straight line is 0 <G3≤ (W + 1/2).
H) -R3, and the distance (G4) between the tip of the separating means and the surface of the pressing member on the other straight line.
Is in the range of 0 <G4 ≦ (W + 1 / 2H) −R4 (W: width of a margin portion on the leading end side of the recording material in the transport direction, H: width of a flat nip portion formed by the fixing member and the pressing member, R3: fixing member radius, R4: pressing member radius).
Although the separating means are arranged apart from the surface of each member, the gaps G3 and G4 are set to proper values, respectively, and as a result, the position of the tip of each separating means is closer to the nip portion than the leading end of the recording material. It is set in the position of. For this reason,
Even if the leading end of the recording material tries to move to each member side, it is always caught by the separating means located on the moving path. Therefore, the recording material P pulled to each member side by the adhesive force of the toner adheres to the surface of each member. As it is, it is possible to prevent a problem that it gets into the gap G1 and winds around the surface of each member. Further, since the shape of the nip portion is substantially flat, the recording material does not curl.

According to a seventh aspect of the present invention, in the first to sixth aspects, the fixing member includes a plurality of rotatable guide members.
An endless fixing belt that is stretched by the plurality of guide members and rotates, and is configured to rotate the pressure member by being in pressure contact with at least one guide member via the fixing belt. Characterize. When the fixing belt is used as the fixing member, the thin belt heating means is used, so that the rise time is shortened by the high-speed start-up time and the energy saving effect is exhibited.
By adopting the configuration of, the action and effect corresponding to each claim can be expected. According to an eighth aspect of the present invention, in the first to sixth aspects, the pressure member includes a plurality of rotatable guide members and an endless pressure belt that is stretched by the plurality of guide members and rotates. The fixing member is configured to rotate in pressure contact with at least one guide member via the pressure belt. When the pressure belt is used as the pressure member, since the thin belt heating means is used, the rising time is shortened by the high-speed start-up time, and the energy saving effect is exhibited. However, the structures of claims 1 to 6 are adopted. As a result, the action and effect corresponding to each claim can be expected.

According to a ninth aspect of the present invention, in the first to eighth aspects, the tip of the separating means, the surface of the fixing member, or /
And a gap (G1, G2, G) from the surface of the pressure member.
(3, G4) is 0.2 m in the fixing temperature state.
2. The structure according to claim 1, wherein the structure is set to m or less.
9. The fixing device according to claim 8. The interval value is
Although it depends on the model, setting to 0.2 mm or less is often effective. According to a tenth aspect of the present invention, in any one of the first to ninth aspects, the toner image is at least a resin,
It is characterized in that it is formed by a toner containing a colorant and a wax. According to this, it is possible to make oil-less, cost reduction and maintenance-free can be made by oil-less, and it is possible to eliminate stains of recording material due to oil. An image forming apparatus according to an eleventh aspect of the present invention is the image forming apparatus according to any one of the first to tenth aspects, including an electrophotographic image forming unit, and a writing unit for irradiating optical image information on an image carrier forming the image forming unit. It is characterized in that the feeding means for feeding the recording material to the image forming means and the recording material having the toner image transferred by the image forming means are fixed by heat and pressure. According to this, it is possible to provide the image forming apparatus that can surely separate the recording material in the fixing unit without uneven gloss.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below with reference to the drawings. FIG. 1 is a vertical sectional view showing a schematic configuration of an image forming apparatus including a fixing device according to an embodiment of the present invention.
An electrophotographic image forming means 2 for forming a toner image T on the recording medium, a feeding means 3 for feeding a recording material to the image forming means 2, and a fixing device 4 for fixing the toner image formed on the recording material. have. The image forming means 2 illustrated here has a drum-shaped photoconductor 5 which is an example of an image carrier, and when the photoconductor 5 rotates clockwise, the surface of the photoconductor has a predetermined polarity by the charging device 6. Be charged to. The charged surface is irradiated with a light-modulated laser beam L emitted from a laser writing unit 7 which is an example of an exposure device, whereby an electrostatic latent image is formed on the surface of the photoconductor. This electrostatic latent image is visualized as a toner image by the developing device 8, and the toner image is transferred onto the recording material sent from the feeding means 3 by the action of the transfer device 9. The transfer residual toner adhering to the surface of the photoreceptor after the toner image transfer is removed by the cleaning device 10. The feeding unit 3 has a cassette 11 containing a recording material P made of, for example, a transfer paper or a resin sheet, and the uppermost recording material P is fed from the cassette 11 by the rotation of the feeding roller 12. The recording material P sent from the cassette 11 is rotated by the pair of registration rollers 13
The toner image on the photoconductor 5 is transferred to the transfer material between the photoconductor 5 and the transfer device 9, and the toner image on the photoconductor 5 is transferred onto the recording material as described above. The recording material carrying the toner image in this manner continues to pass through the fixing device 4, and at this time, the toner image on the recording material is fixed as described later. The recording material that has passed through the fixing device 4 is discharged onto a tray 14 outside the machine.

FIG. 2A is an enlarged cross-sectional view of the main part of the fixing device according to one embodiment of the present invention, and FIG. 2B is an enlarged view of the main part. The fixing device 4 shown here has a fixing roller 15 as a fixing member and a pressure roller 16 as a pressure member that is in pressure contact with the fixing roller 15, and these rollers 15 and 16 have their peripheral surfaces. The nip portion N is formed by press-contacting each other. The fixing roller 15 and the pressure roller 16 are formed in a hollow cylindrical shape. The fixing roller 15 rotates clockwise, and the pressure roller 16 rotates counterclockwise. Inside both rollers 15, 16,
The heating means 17, 18 such as a halogen heater controlled by a temperature control means (not shown) is arranged, and the nip portion N formed by the pressure contact of both rollers is controlled by ON / OFF control of energization to the heating means 17, 18. It is heated to the proper temperature suitable for fixing. The heating means may be provided only inside the fixing roller 15. Unfixed toner image T
The recording material P supporting the toner image T on the fixing roller 15
The toner image T is fixed to the recording material P by heat and pressure at this time as it is fed to the nip portion N as shown by an arrow A in the state of facing (upward). Further, in this example, the hardness of the outer peripheral surface of the pressure roller 16 is set higher than the hardness of the outer peripheral surface of the fixing roller 15, so that the peripheral surface of the fixing roller 15 is dented at the nip portion N as shown in the figure. A convex nip portion N is formed. When the recording material P passes through the convex nip portion in this manner, the leading end portion of the recording material P is discharged in the tangential direction of the nip portion, that is, in the direction away from the peripheral surface of the fixing roller 15, so that the recording material P is formed. Even when the toner is present on the upper surface of the sheet, the risk that the upper surface of the recording material is attracted to and wound around the peripheral surface of the fixing roller 15 due to the toner that has been melted and the adhesive force is increased. Further, during double-sided copying or the like, the recording material P having toner on the lower surface is passed. In this case, the melted lower surface toner may wind around the pressure roller 16, but By disposing the non-contact type blade-shaped separating means 19 on the peripheral surface of 16 with a gap G1, the recording material to be wound around the pressure roller 16 can be peeled off. A separation guide 30 is arranged above the separation means 19 with a predetermined space therebetween, and guides the recording material P discharged between the separation means 19 and the separation means 19 in the paper discharge direction.

A more specific structural example of the fixing device 4 shown in FIG. 2A will be described. The fixing roller 15 is a core metal 15
a and an elastic layer 15b laminated on the outer peripheral surface thereof, and a release layer 15c laminated on the outer peripheral surface of the elastic layer 15b. The outer diameter of the fixing roller 15 is, for example, 40 mm.
The core metal 15a is made of, for example, an iron hollow roller having an outer diameter of 34 mm and a wall thickness of 1 mm, the elastic layer 15b is made of silicone rubber having a thickness of 3 mm, and the release layer 15c has a thickness of, for example, 10 μm to 30 μm. It consists of a PFA tube. By providing the release layer 15c, it is possible to prevent the recording material P from adhering to the surface of the fixing roller due to the adhesive force of the toner. The pressure roller 16 includes, for example, a cored bar 16a made of an iron hollow roller having an outer diameter of 38 mm and a wall thickness of 1 mm, and an elastic layer 1 laminated on the outer peripheral surface thereof.
6b and a release layer 16c laminated on the outer peripheral surface thereof, the elastic layer 16b is made of, for example, silicone rubber having a layer thickness of 1 mm, and the release layer 16c is, for example, a layer thickness of 10 μm to 30 μm.
It is composed of a PFA tube of μm. Fusing roller 1
The surface hardness of No. 5 is, for example, 45 degrees by the JISA hardness meter, and the surface hardness of the pressure roller 16 is, for example, 8 by the JISA hardness meter.
It is set to 0 degrees. As described above, since the pressure roller is harder, the release layer 15c and the elastic layer 15 of the fixing roller 15 with the pressure roller 16 biting into the surface of the fixing roller 15 are engaged.
b is elastically deformed, and the nip portion N is formed in a shape along the outer shape of the pressure roller. Next, FIG. 2B shows a nip portion N formed by the fixing roller 15 and the pressure roller 16.
9A and 9B are enlarged explanatory diagrams of the recording material P passing through the nip portion N. As shown in the figure, in the vicinity of the exit of the nip portion N, a non-contact type separating means 19 for separating the recording material P immediately after exiting the nip portion N from the surface of the pressure roller 16 is a pressure roller. It is arranged in a non-contact state with respect to the surface of 16.
The separating means 19 can be configured in an appropriate form, but the separating means 19 shown here has a plate-like or sheet-like structure, and the tip portion thereof may be formed in an acute angle as necessary, or as shown in the drawing. Bend to. On the other hand, on the recording material P, a toner image is formed in the image area shown by hatching in FIG. 3 and by the reference numeral IA, and the area outside the image area IA is a blank area where no toner image is formed. It is M. The recording material P is conveyed in the direction indicated by the arrow A and enters the fixing device 4,
The width of the margin M1 on the leading end side in the carrying direction in the carrying direction A is W. This width W is, for example, 3 to 5 mm
It is a degree. FIG. 2B shows a state in which only the margin portion M1 on the front end side has just come out of the exit of the nip portion N,
The state where the rear edge of the margin M1 (the tip of the image area IA) is located at the exit of the nip N is shown.

Here, as shown in FIG. 2B, a separating means 19 for separating the recording material exiting the nip portion N from the surface of the pressure roller 16 is provided with the surface of the pressure roller 16 and the tip of the recording material. It is provided in the space between and without contact. At this time, the position of the leading end of the separating means 19 is such that the trailing end (Ne = nip portion outlet) of the margin M1 on the leading end side of the recording material in the feeding direction is the downstream end of the nip portion N in the recording material feeding direction (nip portion outlet). The position is set to be substantially coincident with the straight line L1 connecting the leading end position of the recording material at the time of reaching the (part) and the center of the pressure roller. It should be noted that the position of the tip of the separating means 19 may be slightly shifted inward or outward with respect to the straight line L1. Further, the leading edge of the recording material and the pressure roller on a straight line L1 connecting the leading edge of the recording material and the center of the pressure roller when the trailing edge (Ne) of the margin M1 is located at the exit of the nip portion N. When the gap (distance) from the 16 surfaces is g1, the relation of g1 = (W / sin θ1) −R1 holds for the gap g1 as a geometric calculation. On the other hand, the straight line L1
Assuming that the gap (distance) G1 between the tip of the separating means 19 and the surface of the pressure roller 16 in the above, the separating means is maintained so that the relationship of 0 <G1 ≦ (W / sin θ1) −R1 can be maintained. The tip position of 19 is defined. However, W: the length of the margin portion (non-image area) on the leading end side of the recording material in the conveying direction, θ1; the angle formed by the nip portion exit portion and the leading end of the recording material with respect to the center of the pressure roller, R1;
The pressure roller radius.

On the other hand, the surface hardness of the pressure roller 16 is set higher than the surface hardness of the fixing roller 15, and preferably the surface hardness of the pressure roller 16 is higher than the surface hardness of the fixing roller 15 with a JISA hardness meter. It is configured to be 20 to 40 degrees larger. By setting the surface hardness of the fixing roller 15 and the pressure roller 16 in this manner,
As shown in (b), the pressure roller 16 is the fixing roller 15
The surface of the fixing roller 15 is compressed and deformed. That is, the surface portion of the fixing roller that is in pressure contact with the pressure roller is elastically deformed into a compressed state. Therefore,
As shown in FIG. 2B, the recording material P
In the state where only the margin M1 on the front end side of the sheet is discharged from the exit of the nip N, the margin M1 has a posture along the tangential direction with respect to the circumferential surface of the pressure roller 16, that is, the fixing roller 1.
Take a posture far away from the circumference of 5. Since the toner image is not formed in the margin portion M1 on the front end side, the margin portion M1 does not adhere to the surface of the fixing roller due to the adhesive force of the toner, and the margin portion M1 is formed on the fixing roller surface at the nip portion N. The pressure roller is discharged from the nip portion N along the tangential direction with respect to the peripheral surface of the pressure roller.
At this time, the margin portion M1 and the surface of the fixing roller 15 are sufficiently separated from each other with a large distance, and in this state, the recording material P
The margin M1 of the fixing roller 15 and the pressure roller 1.
It does not wrap around the surface of 6.

On the other hand, during double-sided image formation, the recording material P having the fixed image on the lower surface and the unfixed image on the upper surface is discharged in the direction of arrow A further than in the state shown in FIG. 2B. Then, the image area IA on the lower surface of the recording material starts to be discharged from the outlet of the nip portion N. Then, the image area of the recording material P adheres to the surface of the pressure roller 16 or tries to adhere to the surface of the pressure roller 16 due to the adhesive force of the melted toner on the image area IA. Pulled. In the case of a recording material having a weak stiffness such as thin paper, the tendency to receive the tension becomes remarkable and the recording material is largely deformed. However, since the separating means 19 is provided in the vicinity of the pressure roller, that is, between the recording material front end and the pressure roller, the recording material front end is separated by the separating means 1 as shown in FIG. 2B.
The recording material P is prevented from wrapping around the surface of the pressure roller 16 by being abutted against the sheet 9 and guided. Although the separating means 19 is arranged apart from the surface of the pressure roller 16, the gap G1 is set to an appropriate value as described above, and as a result, the position of the tip of the separating means is greater than that of the illustrated recording material tip. Is also set in the position near the nip. For this reason,
Even if the leading edge of the recording material tries to move to the pressure roller side, the recording material P pulled to the pressure roller side by the adhesive force of the toner is always caught on the separating means located on the moving path.
However, it is possible to prevent a problem that the toner adheres to the surface of the pressure roller and enters the gap G1 and winds around the surface of the pressure roller 16. Further, according to the present invention, since the presence of the blank portion is used to prevent the toner image portion on the recording material from being attracted to and wound around each member,
In the image formation using the color toners, it is possible to prevent gloss unevenness caused by an increase in gloss that occurs when the toner image portion of the recording material is once adsorbed on one of the members, is wound, and is then peeled off.

Next, the Applicant has found that the relationship between the gap (G1) and the width of the leading edge margin (W) is 0 <G1≤ (W / s).
It was verified by an experiment whether the relationship of in θ1) -R1 is appropriate. As a wrapping test for the recording material, the wrapping property around the pressure roller during double-sided fixing was evaluated as a strict condition setting. As a result, as is clear from the graph of FIG. 4, it was found that the above relationship is established between the gap (G1) and the width (W) of the tip margin. For example, when the pressure roller has a diameter of 40 mm and the width (W) of the leading end margin of the recording material is 3 mm, the gap (G1) is 0.2 mm.
If it is set below, separation will be possible, and if it exceeds this, separation will not be possible. The width (W) of the leading edge margin of the recording material
Is 5 mm, the gap (G1) can be set to 0.6 mm or less, and separation can be performed. Note that the horizontal axis of FIG. 4 shows the paper leading edge margin M1, and the vertical axis shows the gap G between the tip of the separating means and the surface of the pressure roller. The curved line in the graph corresponds to the gap g between the tip of the recording material and the surface of the pressure roller. That is, it shows the value of the gap g in the case of the relationship of g = (W / sin θ) −R. When g <G, ○
(No wrapping), and when g> G, means x (with wrapping). The image forming apparatus shown in FIG. 1 is configured to form a monochromatic, usually black, toner image on the recording material P, but the fixing device 4 of the present invention is also applied to a color image forming apparatus. can do. That is, in a color image forming apparatus, for example, a yellow toner image, a magenta toner image, a cyan toner image, and a black toner image are superposed on the recording material P, and the superposed toner image is fixed by a fixing device. The recording material was particularly easy to wind around the fixing member. However, by adopting the fixing device 4 having the above-mentioned non-contact type separating means to the color image forming apparatus, the fixing roller 15 and the pressure roller 16 are damaged. It is possible to prevent the recording material from wrapping around the fixing roller and the pressure roller while preventing the occurrence of sticking.

Next, FIG. 5 is a main part configuration diagram of a fixing device according to another embodiment of the present invention. In the fixing device 4, the fixing member is a fixing roller (guide member) 15 and a guide roller (guide). Member) 41 and the endless fixing belt 4
0 and. The fixing belt 40 is
The fixing roller 15 that functions as a guide roller (guide member) and another guide roller (guide member) 41 that functions as a tension roller are wound around and driven to rotate. The number of guide rollers may be three or more. Further, a part of the guide member that stretches the fixing belt 40 may be a pad-shaped member or the like instead of the roller-shaped member. On the other hand, the pressure member is composed of a cylindrical pressure roller 16 like the fixing device 4 in the embodiment of FIG. The pressure roller 16, the fixing roller 15, and the guide roller 41 are formed in a columnar shape having a cross-sectional shape with a circular outer peripheral surface. In the example shown in FIG. 41 is also formed in a hollow cylindrical shape. The pressure roller 16 is in pressure contact with the fixing roller 15, which is one guide roller, via the fixing belt 40, whereby the outer peripheral surface of the pressure roller 16 is fixed to the fixing belt 4.
0 is pressed against the outer peripheral surface, and the nip portion N is formed by the pressure contact. The fixing roller 15, the guide roller 41, and the pressure roller 16 rotate in the directions of the arrows, and the fixing belt 40 is driven to run in the direction of the arrow B. When the endless fixing belt 40 travels in this way, the fixing roller 15 and the guide roller 41 play a role of guiding the fixing belt 40, and further, the fixing roller 15 which is one guide roller facing the pressure roller 16. Is the pressure roller 16
Forming a nip portion N in cooperation with the other guide roller 4
The reference numeral 1 serves as a tension roller that applies tension to the fixing belt 40.

Further, in the fixing device shown in FIG.
The heater 1 is installed inside the guide roller 41 and the pressure roller 16.
7A and 18A (heat generating means) are provided, and the fixing belt 40 and the pressure roller 1 are provided by these heaters 17A and 18A.
6 is heated, and the energization of the heaters 17A and 18A is ON / OFF controlled by a temperature control means (not shown), so that the temperature of the nip portion N is maintained at an appropriate temperature suitable for fixing the toner image. Also in this example, the recording material P carrying the toner image T to be fixed passes through the nip portion N while keeping the toner image T in contact with the surface of the fixing belt 40 as indicated by an arrow A. The toner image T is fixed on the recording material P by the action of pressure. Also in the fixing device 4 shown in FIG. 5, the surface hardness of the pressure roller 16 is a guide member (the fixing roller 15 in the example of the drawing) in pressure contact with the fixing belt 40.
Is set to be higher than the surface hardness of the fixing belt 40, and the separating means 19 for separating the recording material P exiting the nip portion N from the surface of the fixing belt 40 is in a non-contact state with the surface of the pressure roller. 2 are arranged under the conditions shown in FIGS. In this way, in the case of the fixing device 4 shown in FIGS. 2A and 2B, the fixing position of the tip of the separating means 19 is defined by the relationship between the surface of the pressure roller 16 and the tip of the recording material. Just like the above, the recording material P can be prevented from being wound around the fixing belt 40 and the pressure roller 16, and the separating means 19 can be prevented from scratching the surfaces of the fixing belt 40 and the pressure roller. It is possible to improve the image quality of the toner image and extend the service life of the fixing belt 40 and the pressure roller 16. Further, in image formation using color toner, uneven glossiness caused by an increase in glossiness caused by the toner image portion of the recording material being once adsorbed on any member, wound, and then peeled off is prevented. When the recording material P exiting the nip portion N is guided and conveyed by the separating means 19 and the recording material P is about to be wound around the pressure roller 16, the recording material P is provided on the surface of the pressure roller in a non-contact manner. The operation of separating from the surface by the separating means is no different from that of the fixing device shown in FIG.

Next, a concrete example of the structure of the fixing device 4 shown in FIG. 5 will be described. The fixing belt 40 is, for example, a polyimide resin substrate having a thickness of 50 μm, and a silicone of 30 degrees by a JISA hardness meter. A rubber having a thickness of 0.2 and having PFA coated to a thickness of 20 μm as a release layer can be used. Further, the nip portion N in FIG. 5 is a first nip portion that abuts only the fixing belt 40 at a portion that does not face the fixing roller 15, and a first nip portion where the pressure roller 16 abuts the fixing roller 15 via the fixing belt 40. And two nip portions. As a result, a wide range of the nip portion N can be formed in the circumferential direction of the fixing belt 40, the pressure contact force between the pressure roller 16 and the fixing belt 40 can be made relatively small, and the proper temperature of the nip portion N can be lowered. it can. Further, in the fixing device shown in FIG. 2, since the fixing roller 15 is heated by the heater 17 from the inside of the rubber elastic layer 15b having poor thermal conductivity,
It takes a long time for the fixing roller 15 to rise to a temperature suitable for fixing a toner image when the fixing device is started up. However, in the fixing device shown in FIG. 5, the fixing belt having a small thickness and a small heat capacity is used. 40 is used as a fixing member, and the fixing belt 40 is not heated from the inside of the fixing roller 15 but is heated by the heater 17A in the guide roller 41 having a thin surface layer portion. It is possible to shorten the time until the temperature rises to the temperature suitable for fixing. The test conditions when the separability of the recording material was tested using the belt fixing device shown in FIG. 5 are as follows. The conveyance speed was 200 mm / s, thin paper 45 k was used as the recording material, and oilless toner (containing WAX) was used as the toner. As a result, the recording material P exiting the nip portion N can be prevented from wrapping around the surface of the pressure roller 16, and since the separating means 19 is not in contact with the surface of the pressure roller 16, the surface of the pressure roller 16 can be prevented. In addition, it was possible to prevent the problem of being damaged by the separating means. here,
The width of the image leading edge margin M1 (W) is generally set within the range of 3 to 7 mm as the product specifications of other companies in the same industry. The lower limit set value that can be separated by the separating means 19 of the present invention is when the width of the leading end margin M1 of the recording material is 3 mm. It is obvious that the gap (G1) should be set to 0.2 mm or less as described above to enable the separation of the recording material under such conditions.

As described above, in the fixing device shown in FIG. 2, since the fixing roller 15 is heated by the heater 17 from the inside of the rubber-made thick elastic layer 15b having a poor thermal conductivity, It takes a long time for the fixing roller 15 to rise to a temperature suitable for fixing the toner image at startup. FIGS. 6A and 6B are a main part configuration diagram and a main part enlarged view of a fixing device that solves such a problem. The basic configuration and the basic operation of the fixing device 4 shown here are the same as those of the fixing device 4 shown in FIG. The different configuration is that the surface hardness of the pressure roller 16 is set lower than the surface hardness of the fixing roller 15, and the fixing roller elastically compresses and deforms the pressure roller in the nip portion N. Therefore, the nip portion N is a concave nip portion, which is the opposite of that shown in FIG. Further, in the fixing device shown in FIG. 6, the heater is not provided in the pressure roller 16, but the fixing roller 15 is provided with the heater 17 inside the relatively thin elastic layer. Since the fixing roller 15 is heated, it can be started up in a relatively short time before the fixing roller 15 rises to a temperature suitable for fixing a toner image when the fixing device is started up. Here, when the toner image T carried on the recording material P passes through the nip portion N between the fixing roller and the pressure roller, the toner is melted in the nip portion N. In order to prevent the recording material P coming out of the nip portion N from wrapping around the surface of the fixing roller and the pressure roller, especially the pressure roller, due to the adhesive force of the toner at this time, the following configuration is adopted. That is, FIG. 6B is an enlarged explanatory view of the nip portion N formed by the fixing roller 15A and the pressure roller 16 and the recording material P passing through the nip portion N. In the vicinity of the exit of the nip portion N, a separating means 20 for separating the recording material P exiting the nip portion N from the surface of the fixing roller 15 is provided.
It is arranged in a non-contact state with the surface of the fixing roller 15. The separating means 20 can be configured in an appropriate form, but the separating means shown here is constituted by a plate-like separating member or a sheet-like separating member made of heat-resistant resin, metal or the like. The thinner the thickness, the more preferable, but considering rigidity, the range of 0.1 mm to 0.2 mm is preferable.

On the other hand, the recording material P is shaded in FIG.
In addition, a toner image is formed in the image area indicated by reference numeral IA, and the area outside the image area IA is the blank portion M where the toner image is not formed. The recording material P is conveyed in the direction indicated by the arrow A and enters the fixing device, and the width of the margin portion M1 on the leading end side in the conveyance direction in the conveyance direction A is W. The width W is, for example, about 3 to 5 mm. FIG. 6B shows a state where only the leading end side margin M1 of the recording material has just come out of the nip portion N. here,
As shown in FIG. 6B, the tip of the separating means 20 for separating the recording material exiting the nip portion N from the surface of the fixing roller 15 is provided at least between the surface of the fixing roller 15 and the leading edge of the recording material. And the leading edge of the recording material when the trailing edge (Ne) of the margin on the leading edge side of the recording material in the transporting direction reaches the downstream edge (nip portion outlet) of the nip portion in the recording material transporting direction. The tip of the separating means 20 is arranged at a position substantially coincident with the straight line L2 connecting the center of the fixing roller. As a result, at the tip of the separating means 20, the tip of the recording material is the fixing roller 1.
The protrusion of the recording material can be prevented from coming into contact with the surface of the fixing roller. Further, when a gap (gap) between the front end of the recording material and the surface of the fixing roller in the direction along the straight line L2 is g2, the gap g2 is g2 = (W / sin θ
2) The relationship of -R2 holds as geometric calculation. On the other hand, the tip of the separating means 20 and the fixing roller 1 on the straight line L2.
If the gap (distance) between the five surfaces is G2, the value of the gap G2 is set so that the relationship of 0 <G2 <(W / sin θ2) -R2 can be maintained. Where W is the width of the margin portion on the leading end side of the recording material in the conveying direction, θ2 is the angle formed by the exit of the nip portion and the leading end of the recording material with respect to the center of the fixing roller, R
2; fixing roller radius.

On the other hand, the surface hardness of the fixing roller 15 is set higher than the surface hardness of the pressure roller 16, and preferably the surface hardness of the fixing roller is 20 to 40 on the JIS A hardness scale than the surface hardness of the pressure roller. It is configured to be large. By appropriately setting the surface hardness difference between the fixing roller and the pressure roller in this way, as shown in FIG. 6A, the fixing roller 15 bites into the surface of the pressure roller 16 and compresses and deforms the surface of the pressure roller. Let That is, the portion of the pressure roller that is in pressure contact with the fixing roller is elastically deformed into a compressed state. Therefore, as shown in FIG. 6B, when only the margin portion M1 on the front end side of the recording material P comes out from the nip portion N during the single-sided image formation, the margin portion M1 is formed on the peripheral surface of the fixing roller 15. On the other hand, it takes a posture along the tangential direction, that is, a posture largely separated from the peripheral surface of the pressure roller 16. At this time, since the toner image is not formed on the margin M1 on the leading end side of the recording material, the margin M1 does not adhere to the surface of the fixing roller due to the adhesive force of the toner, and the margin M1 is the nip portion. At N, the toner is discharged from the nip portion N while extending along the tangential direction with respect to the peripheral surface of the fixing roller that bites into the pressure roller side. At this time, the margin M1 and the pressure roller surface are separated by a large distance, and in this state, the margin M1 of the recording material P does not wind around the surface of the fixing roller and the surface of the pressure roller. Even if the leading end of the recording material tries to be displaced toward the surface of the fixing roller, the leading end of the separating means 20 is located in the displacement path, so that there is a problem that it contacts the separating means in the middle and wraps around the surface of the fixing roller. Disappear. Since the separating means 20 is arranged as described above, it is possible to prevent the recording material P exiting the nip portion N from winding around the surface of the fixing roller 15 in this embodiment, and the separating means 20 fixes the fixing material. Since the surface of the fixing roller is not in contact with the surface of the fixing roller, it is possible to prevent the surface of the fixing roller from being damaged by the separating means. Further, in image formation using color toner, uneven glossiness caused by an increase in glossiness caused by the toner image portion of the recording material being once adsorbed on any member, wound, and then peeled off is prevented. The present embodiment can be applied to a fixing device of a color image forming apparatus using a plurality of toners. In a color image forming apparatus, since a superposed toner image in which a plurality of toners are superposed is fixed by a fixing device, conventionally, a recording material was particularly easy to wind around a fixing member. By adopting the apparatus configuration, it is possible to prevent the recording material from being wound around the fixing member and the pressing member while preventing the fixing member and the pressing member from being damaged.

Here, a more specific structural example of the fixing device shown in FIG. 6 will be described. That is, the fixing roller 15 includes a core metal 15a, an elastic layer 15b laminated on the outer peripheral surface of the core metal,
The release layer 15c is laminated on the outer peripheral surface of the elastic layer, and the outer diameter of the fixing roller 15 is, for example, 40 mm. Core 1
5a is composed of, for example, an iron hollow roller having an outer diameter of 34 mm and a wall thickness of 1 mm, and the elastic layer 15b has, for example, a thickness of 1
The release layer 15c is made of silicone rubber having a thickness of 10 mm, and is composed of a PFA tube having a thickness of 10 μm to 30 μm, for example. By providing such a release layer 15c, it is possible to prevent the recording material P from adhering to the surface of the fixing roller due to the adhesive force of the toner. The pressure roller 16 includes, for example, a cored bar 16a made of an iron hollow roller having an outer diameter of 38 mm and a wall thickness of 1 mm, and an elastic layer 16b laminated on the outer peripheral surface thereof.
And a release layer 16c laminated on the outer peripheral surface thereof, the elastic layer 16b is made of, for example, a silicone rubber having a layer thickness of 3 mm, and the release layer 16c is, for example, a layer thickness of 10 μm to 30 μm.
It is composed of a PFA tube of μm. Fusing roller 1
The surface hardness of No. 5 is, for example, 80 degrees by the JISA hardness meter, and the surface hardness of the pressure roller 16 is, for example, 4 by the JISA hardness meter.
It is set to 5 degrees. Since the fixing roller is harder in this way, the fixing roller elastically deforms in a state where the fixing roller bites into the surface of the pressing roller, and the nip portion N is formed in a shape along the outer shape of the fixing roller.

Next, FIG. 7 is a main part configuration diagram of a fixing device according to another embodiment of the present invention. The characteristic configuration of this embodiment is that the pressure member is a pressure roller as a guide member. 1
6 and a guide roller (guide member or tension roller) 45, and an endless pressure belt 46 stretched endlessly by them. The pressure belt 46 is wound around a guide member including two pressure rollers 16 and a guide roller 45. The number of guide rollers may be three or more. On the other hand, the fixing member is composed of a cylindrical fixing roller 15 as in the fixing device of the above embodiment. The fixing roller 15, the pressure roller 16 and the guide roller 45 are
It is formed in a columnar shape having a cross-sectional shape with a circular outer periphery. In the example shown in FIG.
6 and 45 are also formed in a hollow cylindrical shape. The fixing roller 15 is in pressure contact with the pressure roller 16 which is one of the guide members via the pressure belt 46, whereby the outer peripheral surface of the fixing roller 15 is in pressure contact with the outer peripheral surface of the fixing belt 46, and by the pressure contact. A nip portion N is formed. The pressure roller 16, the guide roller 45, and the fixing roller 15 rotate in the directions of the arrows, respectively, whereby the pressure belt 46 is driven to run in the direction of the arrow B. When the endless pressure belt 46 travels in this way, the pressure roller 16 and the guide roller 45 guide the pressure belt 46, and the fixing roller 15 cooperates with the pressure roller 16 to move the nip portion N. The other guide roller 45 that is formed functions as a tension roller that applies tension to the pressure belt 46.

Further, in the fixing device 4 shown in FIG. 7, heaters 17 and 18 are provided inside the fixing roller 15 and the guide roller 45, and the heater 17 and 18 heat the fixing roller 15 and the guide roller 45. Then, the energization of the heaters 17 and 18 is controlled to be turned on and off by the temperature control means (not shown), and the temperature of the nip portion N is maintained at an appropriate temperature suitable for fixing the toner image. Also in this example, the recording material P carrying the toner image T to be fixed passes through the nip portion N in the direction in which the toner image T is in contact with the surface of the pressure belt 46 as shown by an arrow A. The toner image T is fixed on the recording material P by the action of heat and pressure. Also in the fixing device 4 shown in FIG. 7, the surface hardness of the fixing roller 15 is set to be higher than the surface hardness of the guide member (the pressing roller 16 in the example of the drawing) pressed against the pressing belt 46, and the nip Separation means 20 for separating the recording material P exiting the portion N from the surface of the fixing roller 15 is arranged as described above in a non-contact state with the surface of the fixing roller. Therefore, the recording material P is prevented from wrapping around the pressure belt 46 and the fixing roller 15 in exactly the same manner as the fixing device shown in FIG.
The surface of the sheet can be prevented from being scratched, the quality of the toner image after fixing can be improved, and the pressure belt 46 and the pressure roller 16
Can extend the life of the. Further, in image formation using color toner, uneven glossiness caused by an increase in glossiness caused by the toner image portion of the recording material being once adsorbed on any member, wound, and then peeled off is prevented.
Further, the recording material P exiting the nip portion N is guided and conveyed by the separating means 20, and when the recording material P is going to be wound around the fixing roller 15, the above-mentioned separation provided on the surface of the fixing roller in a non-contact manner. Separation from the surface by means 20 is also the same as in the case of the fixing device shown in FIG. Explaining a specific configuration example of the fixing device shown in FIG. 7, the pressure belt 46 includes, for example, a polyimide resin substrate having a thickness of 50 μm and a silicone rubber having a thickness of 30 degrees measured by a JIS A hardness meter of 0.2. It is possible to use, as a release layer, a PFA layer having a thickness of 20 μm coated thereon as a release layer. Further, the nip portion N shown in FIG.
That contacts only the pressure belt 46 at a portion that does not face the first
And the fixing roller 15 is in contact with the pressure roller 16 via the pressure belt 46. As a result, a wide range of the nip portion N can be formed in the circumferential direction of the pressure belt 46, the pressure contact force between the fixing roller and the pressure belt can be made relatively small, and the nip portion N can be formed.
The appropriate temperature can be lowered.

Further, in the fixing device shown in FIG.
Since the fixing roller 15 is heated by the heater 17 from the inside of the rubber elastic layer having poor thermal conductivity, it takes a long time for the fixing roller 15 to rise to a temperature suitable for fixing a toner image when the fixing device is started up. Although it takes time, in the fixing device shown in FIG. 7, the fixing roller 15 has a heater 17 provided inside a relatively thin elastic layer, and a fixing belt 46 having a small thickness and a small heat capacity is fixed. Instead of heating the pressure belt 46 as a member from the inside of the pressure roller, the heater 1 in the guide roller 45 having a small thickness is used.
Since it is heated by 8, the time required for the pressure belt 46 to rise to a temperature suitable for fixing the toner image can be shortened. As the sheet-shaped separating means 20, a thin plate made of heat-resistant resin or metal can be used, and for example, a polyimide sheet having a thickness of 0.1 mm coated with a fluororesin can be used. Further, when a sheet or plate material having a thickness of 0.2 mm or more is used as the separating means 20, its rigidity increases, so that the distance between the separating means and the fixing member or the pressure roller can be kept constant. It will be possible.

Next, FIGS. 8 (a) and 8 (b) are views showing a main structure of a fixing device 4 according to another embodiment of the present invention, and are formed by a fixing roller 15 and a pressure roller 16. 6 is an enlarged explanatory view of a nip portion N and a recording material P passing through the nip portion N. FIG. In the fixing device of this embodiment, the separating means 20 and 19 which are not in contact with the respective surfaces of the fixing roller 15 and the pressure roller 16 are arranged in a predetermined positional relationship so as to separate the recording material from both rollers. It is characteristic that it is designed to prevent wrapping. That is, as shown in the figure, separating means 20, 19 for separating the recording material P exiting the nip portion N from the surfaces of the fixing roller 15 and the pressure roller 16 are provided near the exit of the nip portion N, respectively. Fusing roller 1
5 and the surface of the pressure roller 16 are arranged in a non-contact state. The separating means 20 and 19 can be configured in an appropriate form. The separating means shown here is constituted by a sheet-like separating means. The surface hardness of the pressure roller 16 is set to be substantially the same as the surface hardness of the fixing roller 15. By setting the surface hardness of the fixing roller and the pressure roller to be equal to each other, the nip portion N formed by the pressure roller and the fixing roller is compressed and deformed into a substantially flat shape as shown in FIG. Therefore, as shown in FIG. 8B, the recording material P
When only the margin portion M1 on the front end side of the is out of the exit of the nip portion N, the margin portion M1 takes a posture along the same direction as the flat nip portion N. Since the toner image is not formed on the margin portion M1 on the front end side, the margin portion M1 is fixed to the fixing roller 15 and the pressure roller 1 by the adhesive force of the toner.
The blank portion M1 does not adhere to the surface of 6, and is discharged from the nip portion N along the flat extension line of the nip portion N. In this state, the margin M1 of the recording material P does not wind around the surface of the fixing roller.

When the double-sided image formation is assumed, the recording material P is conveyed further in the direction of arrow A than in the state shown in FIGS. 8A and 8B, and the image shown in FIG. The area IA starts to be discharged from the outlet of the nip portion N. Then, the recording material P adheres to the surface of the fixing roller 15 or the pressure roller 16 or tries to adhere to the surface of the fixing roller 15 or the pressure roller 16 due to the adhesive force of the toner on the image area IA. It is pulled. This tendency is remarkable in the case of a recording material having a weak stiffness such as thin paper. However, since the separating means 20 and 19 are provided in the vicinity of the fixing roller 15 and the pressure roller 16, respectively, when the recording material P is about to be displaced to one of the rollers, the separating means 20 or 19 is provided. The recording material P is prevented from wrapping around the surface of the fixing roller or the pressure roller by being guided by contacting with. The respective leading ends of the separating means 20 and 19 are arranged apart from the surface of the fixing roller, and the trailing end (Ne) of the margin M1 on the leading end side of the recording material P in the feeding direction is the nip portion N. End of the recording material when reaching the downstream end (nip portion exit portion) in the direction, the fixing roller 15, and the pressure roller 16
The tip ends of the separating means 20 and 19 are arranged at positions substantially coincident with the straight lines L3 and L4 connecting the respective rotation centers. Further, when the gap (gap) between the front end of the recording material and the surface of the fixing roller 15 on the straight line L3 is g3, the relation of g3 = (W + 1 / 2H) -R3 holds for the gap g3. . On the other hand, when the gap (distance) between the tip of the separating means 19 and the surface of the fixing roller 15 on the straight line L3 is G3, the gap G3 is 0 <G3 ≦ (W
+ 1 / 2H) -R3 is maintained. Further, when the gap (space) between the front end of the recording material P and the surface of the pressure roller 16 on the straight line L4 is g4, the gap g4 is g4 = (W + 1 / 2H).
The relation of −R4 holds as geometric calculation. On the other hand, the straight line L
If the gap between the tip of the separating means 19 and the surface of the pressure roller 16 on G4 is G4, the gap G4 is 0.
<G4 ≦ (W + 1 / 2H) −R4 is maintained. Here, W is the width of the margin on the leading end side of the recording material in the transport direction, H is the width of the nip formed by the fixing roller and the pressure roller, R3 is the fixing roller radius, and R4 is the pressure roller radius. The recording material P exiting the nip portion N is continuously conveyed while being guided by the separating means 20 located on the upper side and the separating means 19 on the pressure roller side located below the separating means 20. Further, when the recording material P tries to wind around the surface of the pressure roller 16 during double-sided printing, the separating means having the positional relationship with the pressure roller 16 is set similarly to the separating means 20 on the fixing roller 15 side. It is separated from the surface of the pressure roller 16 by 19. As described above, according to the present embodiment, it is possible to prevent the problem that the recording material P exiting the nip portion N winds around the surface of the fixing roller 15, and the separating means 20 does not contact the surface of the fixing roller 15. Therefore, it is possible to prevent the problem that the surface of the fixing roller, which is low in scratch resistance, is easily scratched by the separating means 20. Similarly, the separating means 19
According to this, it is possible to prevent the recording material P from being wound around the pressure roller 16, and to prevent the surface of the pressure roller from being damaged. As a result of preventing wrapping, occurrence of uneven gloss due to the toner image once adsorbed on the roller surface and then peeled off is prevented.

Next, FIG. 9 is a view showing the structure of a fixing device corresponding to a modification of the embodiment of FIG.
A guide roller 50 including a fixing roller (guide member) 15 and a guide roller (guide member) 50, and a fixing belt 51 stretched endlessly by the rollers 15 and 50 and having a heater 17 therein. Position
A characteristic is that the fixing roller 15 is sandwiched between the pressure roller 16 and the fixing roller 15. That is, similarly to the embodiment of FIG. 8, also in the fixing device 4 shown in FIG. 9, the surface hardness of the pressure roller 16 and the guide member (see the figure) with which the pressure roller 16 comes into pressure contact via the fixing belt 51. In the example, the surface hardness of the fixing roller 15) is set to be substantially the same, and the separating means 20 for separating the recording material P exiting the nip portion N from the surface of the fixing belt 51 is not attached to the surface of the fixing belt 51. It is placed in contact. Moreover, as in the case of FIG. 8B, the gap G3 between the tip of the separating means 20 and the surface of the fixing belt 51 on the straight line L3 is such that the margin portion M1 on the tip side of the recording material P in the conveying direction is in the conveying direction. It is set to be smaller than the width W in. That is, as shown in FIG. 8B, the leading end of the separating means 20 is closer to the nip than the position of the leading end of the recording material when the trailing edge of the margin M1 is located at the exit of the nip. It's getting in. The separating means 19 on the pressure roller 16 side is also arranged in a non-contact state with the surface of the pressure roller under the same conditions as the separating means 19 in FIG. 8B. With this configuration, the fixing device 4 of FIG.
Just like the above, the recording material P is prevented from being wound around the fixing belt 51 and the pressure roller 16, and the separating means 20 or 1 is used.
9 can prevent the surface of the fixing belt 51 and the pressure roller 16 from being scratched, improve the image quality of the toner image after fixing, and extend the life of the fixing belt 51 and the pressure roller 16.

By the way, in each of the fixing devices described above, a release agent such as silicone oil can be applied to the fixing member or the pressure roller in order to more reliably prevent the recording material from wrapping around. However, when this configuration is adopted, the oil adheres to the recording material and the recording material becomes dirty, and maintenance for applying oil becomes complicated,
In addition, the application member for oil application is required, and the cost of the fixing device is increased, which is inevitable. Therefore, if a wax-containing toner is used as the toner and the toner image is formed of a toner containing at least a resin, a colorant, and a wax, so-called oilless can be realized without applying a release agent. The above-mentioned problems can be eliminated. Note that FIG. 1 shows an example of an image forming apparatus that can employ the fixing device having the configuration according to each of the above-described embodiments, but this is merely an example, and image forming apparatuses of other types are shown. It is also possible to adopt each fixing device.

[0037]

As described above, according to the present invention, one-sided or two-sided fixing can be performed regardless of the conditions such as whether or not the oilless toner is used or how the nip shape is set. In order to effectively prevent the problem that the recording material is wrapped around the surface of the fixing member and the pressure member regardless of the mode, the most suitable location of the non-contact type separating means (the tip of the separating means). It is possible to provide a method for selecting the distance between each member). Further, it is possible to provide a fixing device that prevents the problem that the recording material is wrapped around and the image gloss unevenness occurs due to the position and the interval where the separating means is provided so as to face the surface of the fixing member or the pressing member. . Further, it is possible to provide an image forming apparatus including the fixing device. That is, according to the first aspect of the invention, the shape of the nip portion is set to a shape that guides the leading end of the recording material in the direction of separating from the fixing member, while the non-contact type separating means prevents winding around the pressing member. Moreover, since the arrangement position of the tip of the separating means is defined in relation to the margin of the tip of the recording material, the distance between the tip of the separating means and the pressing member becomes an appropriate value, and static electricity, weakness of the recording material, etc. Regardless of this, the occurrence of wrapping around the pressure member can be prevented. Further, according to the present invention, the presence of the blank portion is used to prevent the toner image portion on the recording material from being wrapped around the pressure member. Therefore, in the image formation using the color toner, It is also possible to prevent uneven gloss from being caused by an increase in gloss that occurs when the toner image portion of the recording material is once adsorbed on one of the members, wrapped around, and then peeled off. According to the second aspect of the present invention, even if the leading end of the recording material tries to move to the pressure member side, it is always caught by the separating means located on the moving path, so that the recording is pulled to the pressure member side by the adhesive force of the toner. While the material P remains attached to the surface of the pressure member,
It is possible to prevent a problem that the material enters the gap G1 and winds around the surface of the pressing member.

According to the third aspect of the present invention, the shape of the nip portion is formed so as to prevent wrapping around the pressure member, while the non-contact separating means prevents wrapping around the fixing member side. Moreover, since the arrangement position of the separation means tip portion is defined in relation to the width of the recording material tip margin portion,
The distance between the tip of the separating means and the fixing member is not too narrow or too wide, and the occurrence of wrapping around the pressure member is prevented regardless of static electricity and the strength of the recording material.
Further, in the image formation using color toner, the toner image portion of the recording material is once adsorbed on one of the members, and the gap between the toner image portion and the other portion resulting from the increase in gloss caused by the peeling is generated. Uneven gloss is also prevented. According to the invention of claim 4, the separating means is arranged so as to be separated from the surface of the fixing member, but the gap G2 is set to an appropriate value, and as a result, the position of the tip of the separating means is greater than that of the leading end of the recording material. Is also set in the position near the nip. For this reason,
Even if the leading edge of the recording material tries to move to the fixing member side, it is always caught by the separating means located on the moving path. Therefore, the recording material P pulled toward the fixing member by the adhesive force of the toner adheres to the surface of the fixing member. As it is, it is possible to prevent a problem that the toner enters the gap G1 and winds around the surface of the fixing member. In the invention of claim 5, the shape of the nip portion is made flat, and the leading end of the recording material is set so as to be guided in the discharge direction via a path equidistant from both members, while preventing winding around the both members. The prevention of wrapping around both members is realized by the non-contact separation means provided in each member. Moreover,
Since the position of the tip of the separating means with respect to each member is defined in relation to the width of the blank area (non-toner image area) located within a predetermined width from the tip of the recording material, it is assumed that a recording material with a weak stiffness is used. Also, it becomes possible to prevent the occurrence of winding around each member. Further, according to the present invention, the existence of the blank portion is used to prevent the toner image portion on the recording material from being attracted to and wound around each member. Therefore, the image formation using the color toner is performed. At
It is also possible to prevent uneven gloss from being caused by an increase in gloss that occurs when the toner image portion of the recording material is once adsorbed on one of the members, wrapped around, and then peeled off.

According to the sixth aspect of the invention, even if the leading end of the recording material is moved to each member side, it is always caught on the separating means located on the moving path, so that it is pulled to each member side by the adhesive force of the toner. The problem that the recording material P enters the gap G1 and sticks to the surface of each member while being attached to the surface of each member is prevented. Further, since the shape of the nip portion is substantially flat, the recording material does not curl. When the fixing belt is used as the fixing member, the thin belt heating means is used, so that the rising time is shortened by the high-speed start-up time, and the energy saving effect is exhibited. By adopting the configuration of, the action and effect corresponding to each claim can be expected. When the pressure belt is used as the pressure member, the thin belt heating means is used, so that the rising time is shortened by the high-speed start-up time and the energy saving effect is exhibited. By adopting the configurations of 6 to 6,
The action and effect corresponding to each claim can also be expected. The value of the interval varies depending on the model, but is 0.2 m as in claim 9.
Setting to m or less is often effective. According to a tenth aspect of the present invention, in the first to ninth aspects, the toner image is formed of a toner containing at least a resin, a colorant and a wax. Also, it can be maintenance-free, and it is possible to eliminate the contamination of the recording material with oil. According to the image forming apparatus of the eleventh aspect of the present invention, it is possible to provide the image forming apparatus which can surely separate the recording material in the fixing section without uneven gloss.

[Brief description of drawings]

FIG. 1 is a schematic sectional view showing an example of an image forming apparatus to which a fixing device of the present invention is applied.

FIG. 2 is a configuration diagram of a main part of a roller fixing device used in the image forming apparatus shown in FIG.

FIG. 3 is a diagram illustrating a margin portion of a recording material.

FIG. 4 is a diagram showing a relationship between a recording material margin and a gap (recording material winding property evaluation result).

FIG. 5 is a main part configuration diagram of a belt fixing device according to another embodiment of the present invention.

FIG. 6 is a configuration diagram of a main part of a roller fixing device according to another embodiment of the present invention.

FIG. 7 is a main part configuration diagram of a belt fixing device according to another embodiment of the present invention.

FIG. 8 is a configuration diagram of a main part of a roller fixing device according to another embodiment of the present invention.

FIG. 9 is a configuration diagram of a main part of a belt fixing device according to another embodiment of the present invention.

FIG. 10 is a configuration diagram of a main part of a conventional fixing device.

[Explanation of symbols]

1 image forming apparatus main body, P recording material, T toner image, 2
Electrophotographic image forming means, 3 feeding means, 4 fixing device, 6 charging device, 7 laser writing unit, 8
Developing device, 9 transfer device, 10 cleaning device, 1
5 fixing roller (fixing member), 15a core metal, 15b
Elastic layer, 15c Release layer, 16 Pressure roller (pressurizing member), 16a Core metal, 16b Elastic layer, 16c Release layer, 17, 18 Heating means, 19 Separation means, N nip part, M1 margin part, 40 Fixing belt, 41 guide roller (guide member).

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Katsuhiro Echigo             1-3-3 Nakamagome, Ota-ku, Tokyo Stocks             Company Ricoh (72) Inventor Naoshi Kikuchi             1-3-3 Nakamagome, Ota-ku, Tokyo Stocks             Company Ricoh (72) Inventor Jun Nakato             1-3-3 Nakamagome, Ota-ku, Tokyo Stocks             Company Ricoh (72) Inventor Jun Yura             1-3-3 Nakamagome, Ota-ku, Tokyo Stocks             Company Ricoh (72) Inventor Takashi Fujita             1-3-3 Nakamagome, Ota-ku, Tokyo Stocks             Company Ricoh (72) Inventor Hirokazu Ikegami             1-3-3 Nakamagome, Ota-ku, Tokyo Stocks             Company Ricoh F-term (reference) 2H033 AA16 BA11 BA12 BA16 BA21                       BB14 BB30 BB38 CA26                 3F053 AA10 AA22 LA02 LB03

Claims (11)

[Claims] 1. A rotatable fixing member heated by heat generating means, and a pressure member rotating in pressure contact with the fixing member.
And a toner image-bearing recording material that passes through a nip portion between the fixing member and the pressure member to fix the toner image on the recording material by the action of heat and pressure. The surface hardness of the fixing member is set higher than the surface hardness of the fixing member to form a convex nip portion, and a separating means for separating the recording material discharged from the convex nip portion from the surface of the pressing member is provided. , Projecting in a non-contact state between the surface of the pressure member and the tip of the recording material, and
The tip of the separating means is located on a straight line connecting the tip of the recording material and the center of rotation of the pressure member when the trailing edge of the margin of the recording material reaches the exit of the convex nip portion. The fixing device characterized in that 2. The distance (G1) between the tip of the separating means and the surface of the pressing member on the straight line is 0 <G1 <W /
sin θ1) -R1 (W; width of the margin on the leading end side of the recording material in the conveying direction, θ1; angle formed by the nip outlet and the recording material leading end with respect to the center of rotation of the pressing member, R1; pressing member The fixing device according to claim 1, wherein the fixing device is in a radius range. 3. A rotatable fixing member heated by heat generating means, and a pressure member rotating in pressure contact with the fixing member.
A fixing device for fixing a toner image on a recording material by the action of heat and pressure by passing a recording material carrying a toner image through a nip portion between the fixing member and the pressure member. The separating member for forming the concave nip portion by setting the surface hardness lower than the surface hardness of the fixing member, and separating the recording material discharged from the concave nip portion from the fixing member surface is a fixing member surface. Between the recording material and the tip of the recording material in a non-contact state, and
The tip of the separating means is arranged on a straight line connecting the tip of the recording material and the center of rotation of the fixing member when the trailing edge of the leading end margin of the recording material reaches the outlet of the concave nip portion. A fixing device characterized by the above. 4. The distance (G2) between the tip of the separating means and the surface of the fixing member on the straight line is 0 <G2 <(W
/ Sin θ2) −R2 (W; width of the margin on the leading end side of the recording material in the conveying direction, θ2: angle formed by the nip outlet and the leading end of the recording material with respect to the center of rotation of the fixing member, R2: fixing member radius 4. The fixing device according to claim 3, wherein the fixing device is in the range of 4). 5. A recording material bearing a toner image, comprising a rotatable fixing member heated by a heat generating means and a pressure member rotating in pressure contact with the fixing member, and the fixing member and the pressure member. In a fixing device that allows the toner image to be fixed to a recording material by the action of heat and pressure by passing through a nip portion of the fixing member, the surface hardness of the pressing member is set to be substantially equal to the surface hardness of the fixing member, Separation means for forming a nip portion and separating the recording material discharged from the flat nip portion from the surface of the fixing member and the surface of the pressing member are provided between the tip of the recording material and the surface of the fixing member. , And one by one in the non-contact state between the tip of the recording material and the pressure member, and when the trailing edge of the leading edge side margin portion of the recording material reaches the exit of the flat nip portion. Rotation of recording material tip and fixing member A rotation center of the heart and the pressure member, respectively connecting onto each straight line, a fixing device, characterized in that the tip of each separating means is constructed so as to be located. 6. The distance (G3) between the tip of the separating means and the surface of the fixing member on the one straight line is 0 <G3.
≤ (W + 1 / 2H) -R3, and the interval (G4) between the tip of the separating means and the surface of the pressing member on the other straight line is 0 <G4≤ (W + 1 / 2H) -R4.
(W: width of the margin on the front end side of the recording material in the transport direction, H: flat nip width formed by the fixing member and the pressing member, R3: fixing member radius, R4: pressing member radius) The fixing device according to claim 5, wherein: 7. The fixing member is composed of a plurality of rotatable guide members and an endless fixing belt which is stretched by the plurality of guide members and rotates, and the pressure member is interposed via the fixing belt. The fixing device according to any one of claims 1 to 6, further comprising a structure in which at least one guide member is pressed and rotated. 8. The pressure member comprises a plurality of rotatable guide members and an endless pressure belt that is stretched by the plurality of guide members and rotates. The fixing member serves as the pressure belt. The fixing device according to any one of claims 1 to 6, further comprising: a configuration in which the fixing device is rotated in pressure contact with at least one guide member. 9. A gap (G1, G1) between the tip of the separating means and the surface of the fixing member and / or the surface of the pressing member.
G2, G3, and G4) are in a fixing temperature state,
9. The fixing device according to claim 1, wherein the fixing device is configured to be 0.2 mm or less. 10. The fixing device according to claim 1, wherein the toner image is formed by a toner containing at least a resin, a colorant, and a wax. 11. An electrophotographic image forming unit, a writing unit for irradiating an optical image information on an image carrier constituting the image forming unit, and a feeding unit for feeding a recording material to the image forming unit. An image forming apparatus, comprising: the fixing device according to any one of claims 1 to 10 for fixing the recording material having the toner image transferred by the image forming means by heat and pressure.