JP2009098202A - Rotor for fixation, fixing device, and image-forming device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To rotate a rotor for fixation by smaller rotational torque even if there exits a member which contacts with the surface of the rotor for fixation to generate sliding friction. <P>SOLUTION: A fixing device is provided with a rotor for fixation which has, on its surface, diamond-shaped carbon layers G, N which contain Si elements and/or F elements, a contacting member which contacts with the diamond-shaped carbon layers G, N to generate sliding friction between the diamond-shaped carbon layers and the contacting member, and a pressing member which contacts with the outer circumference of the rotor for fixation to press the rotor for fixation, and fixes a toner to a recording medium in a part in which the rotor for fixation press-contacts with the pressing member. In addition, the fixing device is provided with a rotor for fixation, a contacting member which contacts with the rotor for fixation to generate sliding friction between the rotor for fixation and the contacting member, and diamond-shaped carbon layers G, N which contain Si elements and/or F elements on the face of the contacting member with which the rotor for fixation contacts. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a fixing rotator, a fixing device, and an image forming apparatus.

  In recent years, in the field of fixing devices in image forming apparatuses, attempts have been made to use diamond-like carbon (hereinafter sometimes simply referred to as “DLC”) as a lubricating protective film.

  For example, in a heating member having an insulating substrate, a resistance layer supported by the insulating substrate and generating heat when energized, and an electrode terminal portion provided at the end of the resistance layer, the fixing film is brought into contact with the surface of the heating member. A heat fixing device is proposed in which a lubricating protective film made of a hydrogenated amorphous carbon film or a diamond-like carbon film is formed on at least one of the sliding surfaces of the fixing film and the heating member. (For example, refer to Patent Document 1).

Further, in order to realize a durable and energy-saving heating device that can be pressed in close contact with the unevenness of the material to be heated, a first elastic layer, a conductive layer that generates heat as a heat source, In a heating device comprising: a second elastic layer; a heating roller in which a release layer for improving mold release properties is formed in this order; and a pressure roller that presses a heated material against the release layer of the heating roller. A proposal has been made that the release layer is a DLC layer having a thickness of 5 μm or less (see, for example, Patent Document 1). Thereby, even if the thickness of the release layer and the second elastic layer is reduced, a good image can be obtained.
JP-A-6-348154 JP 2005-183122 A

  An object of the present invention is to rotate a fixing rotator with a smaller rotational torque even when there is a member that contacts the surface of the fixing rotator and generates sliding friction.

The above problem is solved by the following means.
That is, the invention according to claim 1 is a fixing rotator including a diamond-like carbon layer containing at least one selected from Si element and F element on the surface.

  The invention according to claim 2 is a fixing belt having a heat generating layer and having a diamond-like carbon layer containing at least one selected from Si element and F element on the surface.

  According to a third aspect of the present invention, there is provided a fixing rotating body having a diamond-like carbon layer containing at least one selected from Si element and F element on the surface, and sliding friction with the diamond-like carbon layer. A contact member that is in contact with the diamond-like carbon layer, and a pressure member that is in contact with the outer peripheral surface of the fixing rotator and applies pressure to the fixing rotator, and the fixing rotator and the fixing member In the fixing device, the toner is fixed to the recording medium at a pressure contact portion with the pressure member.

  According to a fourth aspect of the present invention, the fixing rotator includes a heat generating layer, and an inner peripheral surface including a diamond-like carbon layer containing at least one selected from Si element and F element. 4. The fixing device according to claim 3, wherein the contact member is a pressing member that is in contact with the inner peripheral surface and is pressed against the pressure member via the fixing belt.

  The invention according to claim 5 is the fixing device according to claim 3, wherein the contact member is a heat supply member that generates heat and supplies heat to the fixing rotating body.

  According to a sixth aspect of the present invention, there is provided a diamond-like carbon layer containing at least one selected from the Si element and the F element on a contact surface of the fixing rotator with the toner. The fixing device according to any one of items 5 to 5.

  According to a seventh aspect of the present invention, there is provided the diamond-like carbon layer according to any one of the third to fifth aspects, wherein a diamond-like carbon layer containing at least F element is provided on a contact surface of the fixing rotator with the toner. It is a fixing device.

  According to an eighth aspect of the present invention, there is provided a fixing rotator, and a contact member that contacts the fixing rotator so as to generate sliding friction with the fixing rotator. The fixing device includes a diamond-like carbon layer containing at least one selected from Si element and F element on a surface in contact with a rotating body.

  The invention according to claim 9 is provided with a pressing member that contacts an outer peripheral surface of the fixing rotator and applies pressure to the fixing rotator, and the fixing rotator is a fixing belt having a heat generating layer, The fixing device according to claim 8, wherein the diamond-like carbon layer of the contact member is a pressing member that is in contact with an inner peripheral surface of the fixing belt and is pressed against the pressure member via the fixing belt.

  The invention according to claim 10 is the fixing device according to claim 8, wherein the contact member is a heat supply member that generates heat and supplies heat to the fixing rotating body.

  An invention according to an eleventh aspect is an image forming apparatus including the fixing device according to any one of the third to tenth aspects.

  According to the first aspect of the present invention, even when there is a member that generates sliding friction in contact with the surface of the fixing rotator as compared to the fixing rotator not having the diamond-like carbon layer of the present composition. The fixing rotator can be rotated with a smaller rotational torque.

  According to the second aspect of the present invention, as compared with a fixing belt having no diamond-like carbon layer of the present composition, even when there is a member that contacts the surface of the fixing belt and generates sliding friction, the rotation is smaller. The fixing belt can be rotated by torque. Moreover, the diamond-like carbon layer can be softened by containing Si element or F element, and even when a rapid temperature rise is repeated with a fixing belt having a small heat capacity, it is possible to suppress the occurrence of distortion due to shear stress. it can.

  According to the invention of claim 3, the fixing rotator can be rotated with a smaller rotational torque as compared to a fixing device using a fixing rotator that does not have a diamond-like carbon layer of the present composition, Even when it is desired to drive the pressure member to drive the fixing rotating body, it is possible to make it easy to follow.

  According to the fourth aspect of the present invention, the fixing belt can be rotated with a smaller rotational torque than the fixing device using the fixing belt having no diamond-like carbon layer of the present composition, and the pressure member and the pressing member can be rotated. The pressure applied by the member can be increased, and the fixability of the toner to the recording medium can be improved.

  According to the fifth aspect of the present invention, even when the heat supply member is brought into contact with the fixing rotator as compared with the fixing device using the fixing rotator not having the diamond-like carbon layer of the present composition, The rotating body can be rotated with a smaller rotational torque, and even when the heat supply member is brought into contact with other members, such as during continuous paper feeding, the temperature of the fixing rotating body can be further suppressed. be able to.

  According to the sixth aspect of the present invention, compared with a fixing device using a fixing rotator having a diamond-like carbon layer containing no Si element or F element on the contact surface of the toner, The releasability can be improved.

  According to the seventh aspect of the present invention, the toner releasability with respect to the fixing rotator as compared with the fixing device using the fixing rotator having a diamond-like carbon layer containing no F element on the contact surface of the toner. Can be further improved.

  According to the eighth aspect of the present invention, as compared with a fixing device using a contact member having no diamond-like carbon layer of the present composition, the fixing rotator can be rotated with a smaller rotational torque, and pressure is applied. Even when the member is driven to drive the fixing rotator, slippage of the fixing rotator can be suppressed.

  According to the ninth aspect of the present invention, the fixing belt can be rotated with a smaller rotational torque than the fixing device using the contact member having no diamond-like carbon layer of the present composition, and the pressure member and the pressing member can be rotated. The pressure applied by the member can be increased, and the fixability of the toner to the recording medium can be improved.

  According to the tenth aspect of the present invention, the fixing rotator can be used even when the heat supply member is brought into contact with the fixing rotator as compared with the fixing device using the contact member having no diamond-like carbon layer of the present composition. The rotating member can be rotated with a smaller rotational torque, and even if the heat of the fixing rotating body is taken away by another member such as during continuous paper feeding by contacting the heat supply member, the temperature drop can be further suppressed. it can.

  According to the eleventh aspect of the present invention, an excellent fixed image can be obtained as compared with the case where this configuration is not provided.

  Hereinafter, preferred embodiments will be described with reference to the drawings. In addition, the same code | symbol is provided to the member which has the same function throughout all the drawings, and the overlapping description may be abbreviate | omitted.

<First Embodiment>
FIG. 1 is a schematic configuration diagram illustrating an image forming apparatus according to the first embodiment. FIG. 2 is a schematic cross-sectional view illustrating the fixing device according to the first embodiment. FIG. 3 is a schematic configuration diagram illustrating the fixing device according to the first embodiment. FIG. 4 is a schematic cross-sectional view showing the layer configuration of the fixing belt according to the first embodiment.
FIG. 2 is a schematic cross-sectional view as seen from the axial direction of the fixing device. FIG. 3 is a schematic cross-sectional view taken along the line 2-2 of FIG. 2 and is a schematic cross-sectional view seen from a direction orthogonal to the axial direction of the fixing device.

  As shown in FIG. 1, the image forming apparatus 100 according to the first embodiment includes a cylindrical photosensitive drum 10 that rotates in one direction (the direction of arrow A in FIG. 1). Around the photosensitive drum 10, a charging device 12 that charges the surface of the photosensitive drum 10 in order from the upstream side in the rotation direction of the photosensitive drum 10, and image light L is irradiated to the photosensitive drum 10 to irradiate the surface. An exposure device 14 that forms a latent image, a developing device 16 that includes developing devices 16A to 16D that selectively transfer toner to the latent image on the surface of the photosensitive drum 10 to form a toner image, and the photosensitive drum 10 An endless belt-shaped intermediate transfer member 18 that is supported in a state where the peripheral surface can circulate, a cleaning device 20 that removes toner remaining on the photosensitive drum 10 after transfer of the toner image, and the photosensitive drum 10. And a static elimination exposure device 22 for neutralizing the surface of the.

  Further, on the inner side of the intermediate transfer member 18, the transfer device 24 that primarily transfers the toner image formed on the surface of the photosensitive drum 10 to the intermediate transfer member 18, and two support rolls 26 </ b> A and 26 </ b> B perform secondary transfer. Therefore, the intermediate transfer body 18 is stretched in such a manner that it can circulate in one direction (the direction of arrow B in FIG. 1). At a position facing the transfer facing roll 28, there is a transfer roll 30 that secondarily transfers the toner image primarily transferred onto the outer peripheral surface of the intermediate transfer body 18 to the recording paper (recording medium) P via the intermediate transfer body 18. The recording paper P is fed in the direction of the arrow C to the press contact portion between the transfer facing roll 28 and the transfer roll 30. Then, the recording paper P on which the toner image is secondarily transferred on the surface at the press contact portion is conveyed in the direction of the arrow C as it is.

  A fixing device 32 that heats and melts the toner image on the surface of the recording paper P and fixes it on the recording paper P is disposed on the downstream side in the conveyance direction (arrow C direction) of the recording paper P. The recording paper P is a paper guide member. It is sent via 36. Further, a cleaning device 34 for removing toner remaining on the surface of the intermediate transfer body 18 is provided at a position along the downstream direction of the rotation of the intermediate transfer body 18 (arrow B direction).

  Next, the fixing device according to the first embodiment will be described.

  As shown in FIGS. 2 and 3, the fixing device 32 according to the first embodiment rotates in one direction (arrow D direction) and has an endless fixing belt 38 as a fixing rotating body, and a fixing belt 38. And a pressure roll 40 as a pressure member that is pressed against the circumferential surface of the fixing belt 38 and rotates in one direction (in the direction of arrow E). And a magnetic field generating device 42 that is spaced apart.

  On the inner peripheral side of the fixing belt 38, a pressure fixing pad 44 as a contact member (pressing member) that forms a contact portion with the pressure roll 40, and a magnetic field generator 42 are opposed to each other via the fixing belt 38 and fixed. A fixed heating element (heat storage layer) 46 as a contact member (heat supply member) disposed in contact with the inner peripheral surface of the belt 38 and a support member 48 that supports the pressure fixing pad 44 are provided. The fixed heating element 46 is supported by a support member 48. At both ends of the fixing belt 38, drive transmission members 50 for transmitting the rotational power are provided in order to rotationally drive the fixing belt 38.

  Further, a peeling member 52 is provided on the downstream side of the contact portion between the fixing belt 38 and the pressure roll 40 in the conveyance direction (arrow F direction) of the recording paper P. The release member 52 includes a support portion 52A having one end fixedly supported and a release sheet 52B supported by the support member 52A. The release member 52B is disposed so that the front end of the release sheet 52B approaches or contacts the fixing belt 38.

  Fixing in which a diamond-like carbon layer (hereinafter simply referred to as “Si / F-containing DLC layer”) 64A containing at least one selected from Si element and F element is formed. On the inner peripheral surface side N of the belt 38, the fixing belt 38 and the pressure fixing pad 44 are in contact with each other, and one of them is driven to rotate, whereas one of the sliding surfaces slides while being fixed. Has occurred. Further, in the fixing belt 38 and the fixed heating element 46, “sliding friction” is generated on the sliding surface that slides while one of them is rotationally driven while the other is fixed. Further, on the outer peripheral surface side G of the fixing belt 38 on which the Si / F-containing DLC layer 64B is formed, the fixing belt 38 and the pressure roll 40 are in contact with each other, and one is driven to rotate while the other is driven. "Rolling friction" occurs on the sliding surface that slides in a rotating state.

  First, the fixing belt 38 will be described. As shown in FIG. 4, the fixing belt 38 includes Si / F-containing DLC layers 64 </ b> A and 64 </ b> B on the surface of the belt base material 62 (both the inner peripheral surface side N and the outer peripheral surface side G).

  The base material 62 is a heat generating layer that generates heat by a magnetic field (magnetic flux), is a material that easily penetrates the magnetic field (magnetic flux) and easily generates heat by the action of the magnetic field, and has a smaller heat capacity. Specific examples of the heat generating layer include a heat generating layer containing a nonmagnetic metal material having a thickness of 2 μm to 20 μm (preferably 5 μm to 15 μm). Examples of the nonmagnetic metal material include copper, aluminum, and silver.

Si / F-containing DLC layers 64A and 64B are formed on the surface of the base material 62 (both the inner peripheral surface side N and the outer peripheral surface side G).
Here, diamond-like carbon (DLC) used for the Si / F-containing DLC layers 64A and 64B will be described. FIG. 5 shows the structures of diamond, DLC, and graphite as materials composed of carbon atoms. DLC is a material composed of carbon, composed of both a diamond structure and a graphite structure, and partly has an amorphous structure including a bond with hydrogen. Therefore, DLC has an intermediate property between diamond and graphite.

DLC film is a thin film material obtained by vapor phase synthesis, and is formed by various processes such as PVD (Physical Vapor Deposition) such as ion plating and sputtering, and plasma CVD (Chemical Vapor Deposition). . As a method for containing at least one selected from Si element and F element in the DLC film, a Si-based gas as a feedstock by a direct current plasma CVD method, and a hydrocarbon gas such as CH ₄ (methane) And a method using a mixed gas of hydrocarbon gas such as CH ₄ (methane), a method using a hydrocarbon gas containing F element, and the like.
The content of Si element or F element is adjusted by changing the amount of Si-based gas, the amount of F-based gas, the amount of mixture, the amount of hydrocarbon gas containing F element, or the like.

The fixing belt 38 is not limited to the above configuration, and the base member 62 is a belt in which a heat generating layer is provided on the surface of the base layer, and a Si / F-containing DLC layer is formed on the surface (inner peripheral surface side and outer peripheral surface side). Further, a belt in which the heat generating layer is further provided on the base layer through an elastic layer can be applied.
As the base layer, a material having strength to support the heat generating layer, heat resistance, penetrating the magnetic field (magnetic flux), and not generating heat due to the action of the magnetic field or hardly generating heat can be freely selected. preferable. For example, a metal belt (for example, nonmagnetic stainless steel as a nonmagnetic metal, Fe, Ni, Co, or an alloy thereof such as Fe—Ni, Co—, Fe—Ni—Co, Fe— And a belt made of a metal material using a Cr—Co alloy or the like, a resin belt (for example, a polyimide belt), or the like. Examples of the elastic layer include elastic layers containing silicone rubber, fluorine rubber, fluorosilicone rubber, and the like.

  The fixing belt 38 having a diameter of, for example, 20 mm or more and 50 mm or less can be applied. Further, a lubricant (for example, silicone oil) may be applied to the inner peripheral surface (sliding surface with the pressure fixing pad 44) of the fixing belt 38 on which the Si / F-containing DLC layers 64A and 64B are formed. Good. However, since the lubricant may cause problems such as deterioration with time and contamination due to lubricant leakage, an embodiment in which no lubricant is used (so-called oil-less) is more preferable. In the first embodiment, since the Si / F-containing DLC layer 64A is provided, the rotational torque is satisfactorily suppressed without using a lubricant.

  Next, the pressure roll 40 will be described. In the first embodiment, a mode in which the pressure roll 40 can be separated from the fixing belt 38 is described below, but the fixing belt 38 and the pressure roll 40 may always be in contact with each other. The pressure roll 40 is disposed such that both ends thereof are pressed against the pressure fixing pad 44 by a spring member (not shown) with a total load of 196 N (20 kgf) to 392 N (40 kgf), for example. On the other hand, during preheating (heating until fixing is possible), it is moved away from the fixing belt 38 (not shown).

  The pressure roll 40 is, for example, a roll provided with a metal cylindrical core member 40A and an elastic layer 40B (for example, a silicone rubber layer, a fluorine rubber layer, etc.) provided on the surface of the core member 40A. Can be applied. Further, the pressure roll 40 may be provided with a surface release layer (fluororesin layer) on the outermost surface as necessary.

  Next, the fixed heating element 46 will be described. The fixed heating element 46 is configured to follow the inner peripheral surface of the fixing belt 38, is in contact with the inner peripheral surface side N of the fixing belt 38, and is disposed to face the magnetic field generator 42 via the fixing belt 38. Yes.

  The fixed heating element 46 is disposed in contact with the inner peripheral surface side N of the fixing belt 38 while maintaining the fixing belt 38 in a cylindrical shape by the spring member 48B of the supporting member 48 in a non-contact manner with the supporting member main body 48A. Has been. In the first embodiment, the fixed heating element 46 is in pressure contact with the inner peripheral surface side N of the fixing belt 38 at 1N to 5N. Since no great tension is applied to the belt, the belt shape does not change extremely even if it is pressed.

  The fixed heating element 46 is, for example, a temperature-sensitive magnetic metal material having a Curie point, and is configured to generate heat by the action of a magnetic field. The Curie point is equal to or higher than the set temperature of the fixing belt 38. It is desirable that the temperature be within the range of not more than the heat resistant temperature, specifically, for example, 140 ° C. to 240 ° C., more preferably 170 ° C. to 230 ° C.

  Next, the pressure fixing pad 44 will be described. The pressure fixing pad 44 is composed of, for example, a rod-shaped member having an axial line in the axial direction (width direction) of the fixing belt 38, and resists the pressing force acting from the pressure roll 40. When the pressure roll 40 is pressed against the pressure fixing pad 44 via the fixing belt 38, the fixing belt 38 is deformed to the inner peripheral surface side N. In this way, the sheet is peeled from the fixing belt 38 by giving a curvature to the fixing belt 38 at the downstream side of the contact portion between the pressure roll 40 and the pressure fixing pad 44 in the sheet conveying direction.

  Here, in order to obtain the sheet peeling performance, “whether the pressure roll 40 is pressed against the pressure fixing pad 44 via the fixing belt 38, the fixing belt 38 is elastically deformed to the inner peripheral surface side N. However, since the fixing belt in the first embodiment uses a metal material, the flexibility is determined by a metal layer that determines the rigidity of the fixing belt 38.

  As a material for the pressure fixing pad 44, heat-resistant resin or rubber is optimal in consideration of followability on the sliding surface. A heat-resistant resin such as silicone rubber, PPS (polyphenylene sulfide) containing glass fiber, phenol, polyimide, or a liquid crystal polymer may be used. Other than that, aluminum may be used.

  Next, the support member 48 will be described. The support member 48 includes, for example, a support member main body 48A, a spring member 48B for supporting the fixed heating element 46, a support member main body 48A, and shafts 48C provided at both longitudinal ends of the main body 48A. .

  If the support member main body 48A and the shaft 48C are materials that have a deflection amount or less when the pressing force is received from the pressure roll 40, specifically, for example, a material with a deflection amount of 0.5 mm or less, There is no particular limitation, and the support member main body 48A is made of, for example, a nonmagnetic metal material (eg, copper, aluminum, silver). When the deflection is increased by the load applied to the shaft and the shaft rigidity becomes a problem, for example, a structure made of a member having a Young's modulus with which the deflection is reduced and a nonmagnetic metal may be used.

  On the other hand, the spring member 48B is a connecting member between the fixed heating element 46 and the support member main body 48A, and directly supports the fixed heating element 46. The spring member 48B connects the fixed heating element 46 at both ends in the width direction.

  Further, the spring member 48B is configured by, for example, a curved leaf spring (for example, a leaf spring made of metal, various elastomers, or the like). The fixed heating element 46 is supported by the spring member 48B, and even if the fixing belt 38 rotates eccentrically and the fixing belt 38 is displaced in the radial direction, the fixing belt 38 follows the displacement, and the fixing belt 38 is rotated. The contact state is maintained on the inner peripheral surface of the.

  Next, the drive transmission member 50 will be described. The drive transmission member 50 is a member for transmitting driving power for self-rotating the fixing belt 38. For example, the drive transmission member 50 is a flange portion 50A fitted inside the end portion of the fixing belt 38, and a cylinder having irregularities on the outer peripheral surface. And a gear portion 50B. The drive transmission member 50 can be made of, for example, a metal material, a resin material, or the like.

  The drive transmission member 50 is supported by the end portion of the fixing belt 38 by fitting the flange portion 50 </ b> A inside the end portion of the fixing belt 38. The gear portion 50B of the drive transmission member 50 is rotationally driven by a motor or the like (not shown), and the rotational power is transmitted to the fixing belt 38 so that the fixing belt 38 is self-rotated.

  The drive transmission members 50 are provided at both ends of the fixing belt 38 in the axial direction. However, the drive transmission members 50 are not limited to this, and may be provided only at one end of the fixing belt 38 in the axial direction. The drive transmission member 50 is supported by the end portion of the fixing belt 38 with the flange portion 50A fitted inside the end portion of the fixing belt 38. However, the present invention is not limited to this, and the fixing belt is provided inside the flange portion 50A. The drive transmission member 50 may be supported on the end portion of the fixing belt 38 by fitting the end portion thereof.

  Next, the magnetic field generator 42 will be described. The magnetic field generator 42 is configured to follow the outer peripheral surface of the fixing belt 38, and is opposed to the fixed heating element 46 via the fixing belt 38. The distance from the outer peripheral surface of the fixing belt 38 is, for example, 1 mm or more and 5 mm or less. It is arranged to become. Further, in the magnetic field generator 42, an exciting coil (magnetic field generating means) 42 </ b> A that is wound a plurality of times is arranged along the axial direction of the fixing belt 38.

  An excitation circuit (not shown) that supplies an alternating current to the excitation coil 42A is connected to the excitation coil 42A. On the surface of the exciting coil 42A, a magnetic member 42B is disposed so as to extend along the length direction (the axial direction of the fixing belt 38).

  For example, a magnetic flux (magnetic field) good for the output of the magnetic field generator 42 generates heat while penetrating the heat generating layer of the fixing belt 38.

  The magnetic field generator 42 may be provided at a predetermined distance on the inner peripheral surface side N of the fixing belt 38. In this case, the fixed heating element 46 is provided in contact with the outer peripheral surface side G of the fixing belt 38.

  Hereinafter, the operation of the image forming apparatus 100 according to the first embodiment will be described.

  First, the surface of the photosensitive drum 10 is charged by the charging device 12, and then the image light L is irradiated from the exposure device 14 to form a latent image on the surface of the photosensitive drum 10 due to the difference in electrostatic potential. Then, the rotation of the photosensitive drum 10 in the direction of arrow A moves to a position facing one developing device 16A of the developing device 16, and the first color toner is transferred from the developing device 16A to the surface of the photosensitive drum 10. A toner image is formed. The toner image is conveyed to a position facing the intermediate transfer member 18 by the rotation of the photosensitive drum 10 in the direction of arrow A, and is electrostatically primarily transferred onto the surface of the intermediate transfer member 18 by the transfer device 24.

  On the other hand, the toner remaining on the surface of the photosensitive drum 10 after the primary transfer is removed by the cleaning device 20, and the cleaned surface of the photosensitive drum 10 is potentialally initialized by the charge eliminating exposure device 22, and again with the charging device 12. Move to the opposite position.

  Thereafter, the three developing devices 16B, 16C, and 16D of the developing device 16 are sequentially moved to positions facing the photosensitive drum 10, and toner images of the second color, the third color, and the fourth color are sequentially formed by the method for the first color. Then, primary transfer is performed so that four colors overlap each other on the surface of the intermediate transfer member 18.

  The toner image superimposed on the intermediate transfer body 18 is conveyed to a position where the transfer roll 30 and the transfer counter roll 28 face each other by the circular movement of the intermediate transfer body 18 in the direction of arrow B, and is fed to the recording paper P that has been fed. Touched. A transfer bias voltage is applied to the transfer roll 30 and the intermediate transfer member 18, and the toner image is secondarily transferred to the surface of the recording paper P.

  The recording paper P holding the unfixed toner image is conveyed to the fixing device 32 via the paper guide member 36.

Next, the operation of the fixing device 32 according to the first embodiment will be described.
First, in the fixing device 32, for example, at the same time when the toner image forming operation in the image forming device 100 is started (of course, there may be a time lag. The same applies hereinafter), and the fixing belt 38 and the pressure roll. The drive transmission member 50 is rotationally driven by a motor (not shown) in a state separated from the motor 40, and the fixing belt 38 is rotationally driven in the direction of arrow D at a peripheral speed of, for example, 200 mm / sec.

The fixing belt 38 is driven to rotate, and an alternating current is supplied from an excitation circuit (not shown) to the excitation coil 42A included in the magnetic field generator 42. When an alternating current is supplied to the exciting coil 42A, a magnetic flux (magnetic field) repeatedly generates and disappears around the exciting coil 42A. When this magnetic flux (magnetic field) crosses the heat generating layer of the fixing belt 38, an eddy current is generated in the heat generating layer so that a magnetic field that hinders the change of the magnetic field is generated, and the skin resistance of the heat generating layer and the current flowing through the heat generating layer Heat is generated in proportion to the square.
In addition, the magnetic field generated from the exciting coil 42A passes through the fixing belt 38 and acts on the fixed heating element 46, thereby generating heat. The material and thickness of each metal layer are determined so that the entire metal layer including the heat generation layer included in the fixing belt 38 is equal to or greater than the skin depth of the exciting coil 42A.

  As a result, the fixing belt 38 is heated to a set temperature (for example, 170 ° C.) in 6 seconds to 30 seconds by eddy current loss heat generation in the heat generation layer and heat transfer from the fixed heating element 46.

  Next, in a state where the pressure roll 40 is pressed against the fixing belt 38, the recording paper P sent to the fixing device is sent to the contact portion between the fixing belt 38 and the pressure roll 40, and is heated by the heating element. The fixing belt 38 and the pressure roll 40 are heated and pressed to melt and press the toner image on the surface of the recording paper P, and the toner image is fixed on the surface of the recording paper P.

  Here, the fixed heating element 42 plays a role of supplying heat energy to the fixing belt 38 described below. That is, generally, when fixing the paper P continuously, the heat is lost to the paper P and the peripheral member of the fixing belt 38 that has not reached the predetermined temperature. This makes it difficult to recover the temperature to the set temperature, and a temperature drop occurs. However, the fixed heating element 42 serves as a heat accumulator, and in the state where the temperature of the fixing belt 38 is difficult to recover, heat energy can be supplied to the fixing belt 38 side by heat conduction, so that the temperature drop of the fixing belt 38 can be reduced. it can.

  On the other hand, at the time of fixing by the fixing belt 38 and the pressure roll 40, the fixing belt 38 is slightly pressed and contacted with the fixed heating element 46 having a shape following the shape of the inner peripheral surface thereof, and rotates while being supported. Suppression of vibration by the pressure fixing pad 44 of the belt and electromagnetic force (repulsive force between the magnetic field from the coil and the reaction magnetic field generated by the eddy current flowing in the heat generating layer in the direction to prevent it, that is, the force in the direction away from the coil to the belt) Is fixed, the distance between the belt and the coil is kept good, and the belt shape is maintained for fixing.

  When the recording paper P is sent out from the contact portion between the fixing belt 38 and the pressure roll 40, the recording paper P tries to go straight in the feeding direction due to its rigidity, and the leading end is peeled off from the fixing belt 38 that is bent. The release member 52 (release sheet 52B) enters the gap between the leading edge of the recording paper P and the fixing belt 38, and the recording paper P is released from the surface of the fixing belt 38.

  As described above, the toner image is formed on the recording paper P, and fixing is performed.

  In the first embodiment, the fixing belt 38 is used as the fixing rotator. However, the present invention is not limited to this, and the fixing rotator has a surface (inner peripheral surface side and outer peripheral surface side). A fixing roll having a Si / F-containing DLC layer formed thereon may be used. In this case, the fixed heating element contacts and slides on the inner peripheral surface side of the fixing roll to generate sliding friction, while the pressure roll contacts and slides on the outer peripheral surface side to cause rolling friction. It is good also as the aspect which generate | occur | produced.

<Second Embodiment>
Next, an image forming apparatus according to a second embodiment will be described with reference to the drawings. FIG. 6 is a schematic cross-sectional view showing the surface (sliding surface) of the pressure fixing pad according to the second embodiment. FIG. 7 is a schematic cross-sectional view showing the surface (sliding surface) of the fixed heating element according to the second embodiment.

The image forming apparatus according to the second embodiment does not form the Si / F-containing DLC layer 64A on the inner peripheral surface side N of the base material 62 of the fixing belt 38 in the image forming apparatus according to the first embodiment. On the other hand, the Si / F-containing DLC layer 64C is formed on the sliding surface S of the pressure fixing pad 44 with the fixing belt 38, and the Si / F-containing DLC layer 64C is formed on the sliding surface S of the fixed heating element 46 with the fixing belt 38. An F-containing DLC layer 64D is formed.
In the image forming apparatus according to the second embodiment, the configuration of the image forming apparatus according to the first embodiment is employed as it is except for the above features. Therefore, in the following, only the characteristic part will be described, and description of other components will be omitted.

  Here, the “sliding surface” refers to a surface that slides with another member. In the second embodiment, the pressure fixing pad 44 and the fixed heating element 46 slide with the fixing belt 38. Represents the surface to perform.

In the image forming apparatus according to the second embodiment, as described above, the DLC layer 64A is not formed on the inner peripheral surface side N of the fixing belt 32, that is, the base material 62 remains as it is as the pressure fixing pad 44 and the fixed heat generation. It is configured to come into contact with the body 46 and slide.
As shown in FIG. 6, the pressure fixing pad 44 in the second embodiment has a Si / F-containing DLC layer 64 </ b> C formed on the surface (sliding surface S) of the base material 441. Further, as shown in FIG. 7, in the fixed heating element 46 in the second embodiment, the Si / F-containing DLC layer 64 </ b> D is formed on the surface (sliding surface S) of the base material 461. In addition, as the base material 441 of the pressure fixing pad 44, the material used as the pressure fixing pad 44 in the first embodiment can be used as it is, and the base material 461 of the fixed heating element 46 is the first base material 461. In this embodiment, the material used as the fixed heating element 46 is used as it is.

  For the formation of the Si / F-containing DLC layers 64C and 64D on the sliding surface S of the pressure fixing pad 44 and the fixed heating element 46, the forming method in the first embodiment is used as it is.

  On the sliding surface S of the pressure fixing pad 44 on which the Si / F-containing DLC layer 64C is formed, the pressure fixing pad 44 and the fixing belt 38 are in contact with each other, and one of them is rotationally driven while one is fixed. “Sliding friction” is generated on the sliding surface S that slides in the above state. Also, in the fixed heating element 46 and the fixing belt 38 on which the Si / F-containing DLC layer 64D is formed, one of them is driven to rotate while the other sliding surface S slides in a fixed state. "Sliding friction" occurs.

  Hereinafter, test examples of the image forming apparatus according to the embodiment will be described.

Example 1
<Fabrication of fixing belt 38>
As the base material 62, the following layers were formed on the outer peripheral surface of an endless belt made of polyimide (inner diameter: 30 mm, thickness: 60 μm) to prepare a base material. First, copper (thickness 10 μm) is formed by plating, vapor deposition, sputtering, etc. as a heat generating layer, then nickel (thickness 9 μm) is formed as a protective layer by copper, and silicon rubber (thickness) is further formed as an elastic layer. 300 μm), and PFA (thickness 30 μm) was formed as a release layer.

Next, DLC having a Si element content of 1% or more and less than 3% (atomic%) on both the inner peripheral surface side N and the outer peripheral surface side G of the base material 62 by plasma CVD or SP (sputtering). The layer was formed with a thickness of 3 μm to obtain a fixing belt 38.
The element content is the ratio of the number of atoms to C atoms, and is determined by RBS method (Rutherford Backward Dispersion Analysis method), HFS method (Hydrogen Forward Scattering Spectrometry), GD-OES method (Glow Discharge Emission Analysis method), etc. It can be measured.

[Evaluation]
(1) Measurement of dynamic friction coefficient The dynamic friction coefficient of the fixing belt 38 was measured by the following method.
With a pin-on-disk type frictional wear tester conforming to JIS K 7218, the surface with the DLC layer applied is pressed against the fixed pin, the rotation speed is 30 rpm, the surface pressure is 0.7 Gpa, at room temperature (25 ° C.), no Evaluation was performed with a test time of 10 minutes under lubrication.
-Evaluation criteria-
◎: 0.01 or more and less than 0.05 ○: 0.05 or more and less than 0.09 Δ +: 0.09 or more and less than 0.13 Δ: 0.13 or more and less than 0.17 ×: 0.17 or more

(2) Measurement of rotational torque With respect to the fixing belt 38, the rotational torque was measured by the following method.
The rotational torque was derived by calculating from the current value of the DC motor that drives the fixing belt. The characteristics of the rotational speed and driving force (torque) of the motor with respect to a known driving load were measured in advance, and the rotational torque was calculated from the motor driving current of the actual object.
-Evaluation criteria-
◎: 0.1 Nm or more and less than 0.3 Nm ○: 0.3 Nm or more and less than 0.5 Nm Δ +: 0.5 Nm or more and less than 0.7 Nm Δ: 0.7 Nm or more and less than 0.9 Nm ×: 0.9 Nm or more

(3) Sliding characteristics (change in rotational torque over time)
The fixing belt 38 was attached to a fixing device in an image forming apparatus (trade name: Docu Center Color 3300, manufactured by Fuji Xerox Co., Ltd.). The total load by the pressure roll was set to 294 N (30 kgf), and 50000 sheets of images were formed in a state where no lubricant was applied to the inner peripheral surface of the fixing belt 38, and the rate of increase in rotational torque was observed. Evaluation was made according to the following evaluation criteria.
-Evaluation criteria-
○: Rotation torque increase + 10% or less △ +: Rotation torque increase + 12% or less △: Rotation torque increase + 15% or less ×: Rotation torque increase + 15% or more

(4) Durability against shear stress The fixing belt 38 was attached to a fixing device in an image forming apparatus (trade name: Docu Center Color 4300, manufactured by Fuji Xerox Co., Ltd.). The set temperature of the fixing belt 38 is set to 170 ° C., the rate of temperature increase is set to 25 ° C./second, and 50000 sheets of images are formed in a rapid heating state. And the occurrence of peeling was observed. Evaluation was made according to the following evaluation criteria.
-Evaluation criteria-
○: No change Δ +: 10 or less micro-peeling △: 20 or less micro-peeling, small amount of abrasion powder ×: There are multiple peelings larger than micro-peeling and generation of abrasion powder

(5) Releasability with toner The fixing belt 38 was attached to a fixing device in an image forming apparatus (manufactured by Fuji Xerox Co., Ltd., trade name: Docu Center Color 3300). An image of 50000 sheets was formed, and the releasability between the fixing belt 38 and the toner was observed. Evaluation was made according to the following evaluation criteria.
-Evaluation criteria-
◎: No peeling performance deterioration ○: Minor image quality disturbance that does not become obvious due to slight deterioration of peeling performance is rare △: Paper deformation amount (curl) increases due to deterioration of peeling performance ×: Due to poor peeling Paper jam

(6) Comprehensive evaluation Comprehensive evaluation was performed according to the following criteria.
-Evaluation criteria-
◎: All the above evaluation items ○ or ◎ Evaluation ○: There is one △ + or △ evaluation, all other evaluation items ○ or ◎ evaluation
(However, the total number of evaluations is more than 2)
Δ: No evaluation, and there is at least one evaluation of Δ +, ○ or ◎ X: Evaluation is × or all the above evaluation items are Δ

(Examples 2 to 6)
In Example 1, the fixing belt 38 was obtained by the method described in Example 1 except that the content of Si element in the DLC layer was changed to the amount described in Table 1 below, and the evaluation described in Example 1 was performed. did.

(Examples 7 to 12)
In Example 1, the fixing belt 38 was obtained by the method described in Example 1 except that the element contained in the DLC layer was changed to the F element and the content was changed to the amount shown in Table 1 below. The evaluation described in Example 1 was carried out. (However, in Examples 10 to 12, only (3) sliding characteristics and (4) durability were evaluated)

(Comparative Examples 1 to 4)
A fixing belt 38 was obtained by the method described in Example 1 except that the DLC layer formed in Example 1 was changed to each layer obtained by the method described in Table 2 below. Inner (5) Evaluations other than releasability were performed.
In Table 2, “SP” refers to sputtering, “AIP” refers to arc ion plating, and “a-C: H film” refers to amorphous carbon having a higher H element content than DLC layers of SP or AIP. ing.

(Example 13)
<Preparation of pressure fixing pad 44>
As the base material 441 of the pressure fixing pad 44, a liquid crystal polymer (trade name: Zenite manufactured by DuPont, or product name: Vectra manufactured by Polyplastics) was prepared.

  Next, a DLC layer having an Si element content of 1% or more and less than 3% (atomic%) is formed on the sliding surface of the base material 441 by plasma CVD or SP method at a thickness of 2 μm and pressed. A fixed pad 44 was obtained.

<Production of Fixed Heating Element 46>
An Fe—Ni magnetic shunt alloy (temperature-sensitive magnetic metal: MS220 manufactured by NEOMAX Materias) was prepared as the base material 461 of the fixed heating element 46.

  Next, a DLC layer having an Si element content of 1% or more and less than 3% (atomic%) is formed on the sliding surface of the substrate 461 by plasma CVD or SP method to a thickness of 2 μm, and fixed heat generation is performed. A body 46 was obtained.

[Evaluation]
(1) Measurement of Dynamic Friction Coefficient With respect to the pressure fixing pad 44 and the fixed heating element 46, the dynamic friction coefficient was measured by the method described in Example 1. The evaluation criteria are as described in Example 1.

(2) Measurement of rotational torque With respect to the pressure fixing pad 44 and the fixed heating element 46, the rotational torque was measured by the method described in Example 1. The evaluation criteria are as described in Example 1.

(3) Sliding characteristics (change in rotational torque over time)
The pressure fixing pad 44 and the fixed heating element 46 were mounted on a fixing device in an image forming apparatus (trade name: Docu Center Color 3300, manufactured by Fuji Xerox Co., Ltd.). The total load of the pressure roll was set to 196 N (20 kgf), and 50,000 sheets of images were formed in a state where no lubricant was applied to the inner peripheral surface of the fixing belt 38, and the rate of increase in rotational torque was observed. The evaluation criteria are as described in Example 1.

(4) Comprehensive evaluation Comprehensive evaluation was performed according to the criteria described in Example 1.

(Examples 14 to 18)
In Example 13, the pressure fixing pad 44 and the fixed heating element 46 were obtained by the method described in Example 13 except that the Si element content in the DLC layer was changed to the amount described in Table 3 below. The evaluation described in 13 was carried out. (However, in Example 15 and Example 16, only (2) Evaluation other than rotational torque was performed)

(Examples 19 to 21)
In Example 13, the element to be contained in the DLC layer was changed to the F element, and the content thereof was changed to the amount described in Table 3 below, and the pressure fixing pad 44 and fixing were performed by the method described in Example 13. A heating element 46 was obtained and the evaluation described in Example 13 was performed. (However, in Example 21, only (2) evaluation other than rotational torque was performed)

(Comparative Examples 5 to 8)
A pressure fixing pad 44 and a fixed heating element 46 were obtained by the method described in Example 13, except that the DLC layer formed in Example 13 was changed to each layer obtained by the method described in Table 4 below. The evaluation described in 13 was carried out.

1 is a schematic configuration diagram illustrating an image forming apparatus according to a first embodiment. 1 is a schematic cross-sectional view illustrating a fixing device according to a first embodiment. 1 is a schematic cross-sectional view illustrating a fixing device according to a first embodiment. 1 is a schematic cross-sectional view illustrating a fixing belt according to a first embodiment. It is a table | surface which shows the structure of a diamond, DLC, and a graphite. It is a schematic sectional drawing which shows the sliding surface of the pressurization fixing pad which concerns on 2nd Embodiment. It is a schematic sectional drawing which shows the sliding surface of the fixed heat generating body which concerns on 2nd Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Photosensitive drum 12 Charging apparatus 14 Exposure apparatus 16 Development apparatus 18 Intermediate transfer body 20 Cleaning apparatus 22 Static elimination exposure apparatus 24 Transfer apparatus 26A, 26B Support roll 28 Transfer opposing roll 30 Transfer roll 32 Fixing apparatus 34 Cleaning apparatus 36 Paper guide member 38 Fixing belt 40 Pressure roll 42 Magnetic field generator 44 Pressure fixing pad 46 Fixed heating element (heat storage layer)
48 Support member 48A Support member body 48C Shaft 50 Drive transmission member 52 Peeling member 62 Belt base material 64A, 64B, 64C, 64D Si / F-containing DLC layer 100 Image forming apparatus 441, 461 Base material P Recording paper

Claims (11)

  A fixing rotator comprising a diamond-like carbon layer containing at least one selected from Si and F elements on the surface.   A fixing belt comprising a heat generating layer and a diamond-like carbon layer containing at least one selected from Si and F elements on the surface. A fixing rotor including a diamond-like carbon layer containing at least one selected from Si and F elements on the surface;
A contact member in contact with the diamond-like carbon layer so that sliding friction occurs with the diamond-like carbon layer;
A pressure member that contacts the outer peripheral surface of the fixing rotator and applies pressure to the fixing rotator,
A fixing device for fixing toner onto a recording medium at a pressure contact portion between the fixing rotating body and the pressure member. The fixing rotator is a fixing belt having a heat generating layer and a diamond-like carbon layer containing at least one selected from Si element and F element on an inner peripheral surface,
The fixing device according to claim 3, wherein the contact member is a pressing member that is in contact with the inner peripheral surface and is pressed against the pressing member via the fixing belt.   The fixing device according to claim 3, wherein the contact member is a heat supply member that generates heat and supplies heat to the fixing rotating body.   6. The diamond-like carbon layer containing at least one selected from the Si element and the F element is provided on a contact surface of the fixing rotator with the toner. The fixing device according to claim 1.   6. The fixing device according to claim 3, further comprising a diamond-like carbon layer containing at least an F element on a contact surface of the fixing rotator with the toner. A fixing rotating body;
A contact member that contacts the fixing rotator so as to generate sliding friction with the fixing rotator,
A fixing device comprising a diamond-like carbon layer containing at least one selected from Si element and F element on a surface of the contact member in contact with the fixing rotator. A pressure member that contacts the outer peripheral surface of the fixing rotator and applies pressure to the fixing rotator;
The fixing rotator is a fixing belt having a heat generating layer;
The diamond-like carbon layer of the contact member is a pressing member that is in contact with an inner peripheral surface of the fixing belt and is pressed against the pressing member via the fixing belt. Fixing device.   The fixing device according to claim 8, wherein the contact member is a heat supply member that generates heat and supplies heat to the fixing rotating body.   An image forming apparatus comprising the fixing device according to claim 3.

Images