JP2005092033A - Fixing roller, fixing device, image forming device, and method of manufacturing fixing roller - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fixing roller which improves durability by preventing peeling of an adhesive between an electromagnetic induction heating member and a heat insulating member and deformation of the electromagnetic induction heating member. <P>SOLUTION: In the fixing roller 1, an adhesive 16 which adhere a heat insulating member 12 and an electromagnetic induction heating member 13 each other exists only in both end parts in an axial direction. A difference between amounts of deformation of the heat insulating member 12 and the electromagnetic induction heating member 13, which results from use of the fixing roller 1 is absorbed in a non-adhesion area W where the adhesive 16 doesn't exist, and thus peeling of the adhesive between the electromagnetic induction heating member 13 and the heat insulating member 12 and deformation of the electromagnetic induction heating member 13 are prevented. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention is, for example, a fixing roller for use in an electrophotographic apparatus such as a copying machine, a laser printer, and a facsimile machine to melt and fix (heat fixing) an unfixed image on a recording material, and a fixing device using the fixing roller. The present invention relates to an image forming apparatus using the fixing device and a method for manufacturing the fixing roller.

  In recent fixing devices, in order to save energy, it is considered to employ an induction heating type heat source capable of obtaining high heat conversion efficiency. In particular, a structure in which a magnetic flux generated by a coil is guided to a conductive heat generation layer of a fixing roller of a fixing device by a core material such as a ferrite core has attracted attention because of its compactness and high efficiency.

  Against this background, an electromagnetic induction heating type fixing device has been proposed that has the same or higher efficiency as a heat roller type fixing device using a halogen heater, and has features that rise quickly. Yes.

  The electromagnetic induction heating type fixing device includes a fixing roller and a pressure roller that form a pressure nip portion, and a magnetic flux generating unit that is disposed outside the fixing roller and generates a magnetic flux.

  This fixing roller is composed of five members in order from the inner side to the outer side in the radial direction: an annular support member, an annular sponge member, an annular electromagnetic induction heating member, an annular elastic member, and an annular release member. .

  Then, the electromagnetic induction heat generating member of the fixing roller is heated by the magnetic flux of the magnetic flux generating means, and the recording material carrying the unfixed image is conveyed while being sandwiched by the pressure nip portion, and this unfixed image is conveyed. Is melt-fixed on this recording material (see Japanese Patent Application Laid-Open No. 2000-214713: Patent Document 1, Japanese Patent Application Laid-Open No. 2000-214714: Patent Document 2).

  However, in the conventional fixing device, in the fixing roller, the electromagnetic induction heating member made of metal and the sponge member have different elastic modulus and coefficient of thermal expansion. There has been a problem that it is peeled off from the sponge member or the electromagnetic induction heating member itself is deformed.

Specifically, since the electromagnetic induction heating member and the sponge member are bonded to each other on the entire circumferential surface, the electromagnetic induction heating member and the sponge member are formed at the boundary surface between the electromagnetic induction heating member and the sponge member. A difference in deformation amount (due to elastic deformation or thermal deformation) with the sponge member could not be absorbed.
JP 2000-214713 A JP 2000-214714 A

  Accordingly, an object of the present invention is to provide a fixing roller capable of improving durability by preventing adhesion peeling between the electromagnetic induction heat generating member and the heat insulating member and deformation of the electromagnetic induction heat generating member.

In order to solve the above problems, the fixing roller of the present invention is:
An electromagnetic induction heating type fixing roller for fusing and fixing the unfixed image on a recording material carrying an unfixed image,
An annular support member, an annular heat insulating member, an annular electromagnetic induction heating member, an annular elastic member, and an annular release member, which are arranged in order from the radially inner side to the outer side;
The heat insulating member and the electromagnetic induction heat generating member include an adhesive that adheres the heat insulating member and the electromagnetic induction heating member to each other only at both ends in the axial direction.

  According to the fixing roller of the present invention, since the adhesive for bonding the heat insulating member and the electromagnetic induction heat generating member exists only at both end portions in the axial direction, the annular portion without the adhesive is provided at the central portion in the axial direction. There are non-adhesive areas.

  Therefore, even if the heat insulating member and the electromagnetic induction heating member having different elastic modulus and thermal expansion coefficient cause a difference in deformation amount during use, the difference in deformation amount is absorbed in the non-adhesive region. It is possible to improve durability by preventing adhesion peeling between the heat insulating member and the electromagnetic induction heating member and plastic deformation of the electromagnetic induction heating member. Further, since the heat insulating member and the electromagnetic induction heating member are bonded with the adhesive only at both ends in the axial direction, the adhesive does not spread to the central portion in the axial direction as will be described later. It can be easily manufactured.

  The fixing roller includes the support member, the heat insulating member, the electromagnetic induction heat generating member, the elastic member, and the release member. Of course, other annular members may be included. is there.

  In the fixing roller according to an embodiment, the annular release member has an annular sheet passing region facing the recording material at a central portion in the axial direction, and the adhesive is more than the sheet passing region. It is located outside in the axial direction and does not overlap the paper passing area in the radial direction.

  According to the fixing roller of this embodiment, the adhesive overlaps the annular non-sheet passing area that does not face the recording material and does not overlap the sheet passing area. The fluctuation in pressure does not adversely affect the image of the recording material, and a good image quality can be obtained. If the boundary between the adhesive region with the adhesive and the non-adhesive region without the adhesive overlaps with the paper-passing region, a difference occurs in the state of heat transfer and pressure, which adversely affects the image. is there.

  In the fixing roller according to the embodiment, the annular electromagnetic induction heat generating member has an annular heat generation region at a central portion in the axial direction, and the adhesive is positioned outside the heat generation region in the axial direction. And does not overlap the heat generating area in the radial direction.

  Here, when the electromagnetic induction heat generating member generates heat by, for example, magnetic flux from the exciting coil, the heat generating region is a region facing the exciting coil.

  According to the fixing roller of this embodiment, since the adhesive does not overlap with the heat generation area, the adhesive can be removed from the high temperature area, the influence on heat can be kept low, and the durability can be kept high. . If the adhesive overlaps the heat generating area, the temperature of the adhesive rises due to the heat generating area and adversely affects the adhesiveness.

  In the fixing roller of one embodiment, the adhesive is continuous in the circumferential direction.

  According to the fixing roller of this embodiment, since the adhesive is continuous in the circumferential direction, toner and dust are prevented from entering between the heat insulating member and the electromagnetic induction heat generating member. Adhesion between the heat insulating member and the electromagnetic induction heating member can be strengthened.

  In one embodiment, the adhesive is discontinuous in the circumferential direction.

  According to the fixing roller of this embodiment, since the adhesive is partially present in the circumferential direction, the cost can be reduced by omitting the material of the adhesive, and the heat insulating member. And the difference in deformation amount between the electromagnetic induction heating member and the electromagnetic induction heating member can be further absorbed to improve durability.

The fixing device of the present invention is
The fixing roller of the invention,
A pressure roller that sandwiches and conveys the recording material together with the fixing roller;
Magnetic flux generating means is provided outside the fixing roller and generates magnetic flux to generate heat from the electromagnetic induction heating member of the fixing roller.

  According to the fixing device of the present invention, since the fixing roller is provided, the durability of the fixing roller can be improved and the life can be extended. Therefore, it is possible to save troubles such as repair, replacement and management of the fixing roller.

The image forming apparatus of the present invention is
An image forming means for forming an unfixed image on the recording material;
And a fixing device according to the invention for fusing and fixing the unfixed image on the recording material.

  According to the image forming apparatus of the present invention, since the fixing device is provided, troubles such as repair, replacement, and management of the fixing roller of the fixing device can be saved, and overall costs for maintenance management and the like can be reduced. Can be reduced.

In addition, the manufacturing method of the fixing roller of the present invention includes
Adhesive is applied to one axial end of the outer peripheral surface of the annular heat insulating member, and adhesive is applied to one axial end of the inner peripheral surface of the annular electromagnetic induction heating member Process,
From the other end of the annular electromagnetic induction heating member to which the adhesive is not applied, the other end of the annular heat insulating member to which the adhesive is not applied in the annular electromagnetic induction heating member. The annular heat insulating member is inserted from the part side, and an adhesion step for adhering the heat insulating member and the electromagnetic induction heating member is provided.

  According to the fixing roller manufacturing method of the present invention, the heat insulating member and the electromagnetic induction heat generating member are overlapped from the side where the adhesive is not applied, so that the adhesive is axially central. The heat insulating member and the electromagnetic induction heat generating member can be reliably bonded only at both ends.

  Therefore, the fixing roller in which the heat insulating member and the electromagnetic induction heating member are bonded at both ends can be reliably manufactured by a simple process.

  When the fixing roller includes a support member, a heat insulating member, an electromagnetic induction heat generating member, an elastic member, and a release member, the order of assembly of the support member, the elastic member, and the release member is as follows. It may be either before or after bonding the electromagnetic induction heating member.

  According to the fixing roller of the present invention, since the heat insulating member and the electromagnetic induction heat generating member are provided with an adhesive that bonds the heat insulating member and the electromagnetic induction heat generating member to each other only at both end portions in the axial direction, The difference in amount can be absorbed in a non-adhesive region where the adhesive is not present, and prevents adhesion peeling between the heat insulating member and the electromagnetic induction heating member and plastic deformation of the electromagnetic induction heating member. Durability can be improved.

  According to the fixing device of the present invention, since the fixing roller of the present invention is provided, durability of the fixing roller is improved, and troubles such as repair, replacement and management of the fixing roller can be saved.

  According to the image forming apparatus of the present invention, since the fixing device of the present invention is provided, durability of the fixing roller of the fixing device is improved, and costs relating to maintenance management and the like can be reduced.

  According to the fixing roller manufacturing method of the present invention, since the heat insulating member and the electromagnetic induction heating member are stacked from the side where the adhesive is not applied, the heat insulating member and the heat insulating member can be combined with each other in a simple process. A fixing roller in which the electromagnetic induction heat generating member is bonded at both ends can be reliably manufactured.

  Hereinafter, the present invention will be described in detail with reference to the illustrated embodiments.

(First embodiment)
FIG. 1A is a cross-sectional configuration diagram showing an embodiment of the fixing device of the present invention, and FIG. 1B is an enlarged cross-sectional view of a main part of the fixing roller of the present invention.

  The fixing device includes a fixing roller 1, a pressure roller 2 that forms a pressure nip N with the fixing roller 1, and a magnetic flux generating unit 3 that is disposed outside the fixing roller 1 and generates a magnetic flux. .

  Then, the fixing roller 1 is heated by the magnetic flux of the magnetic flux generating means 3, and the recording material P carrying the unfixed image t is sandwiched and conveyed at the pressure nip N, and the unfixed image t is transferred to the recording material. P is melt-fixed (heat-fixed).

  The recording material P is, for example, paper such as paper or an OHP sheet, and the unfixed image t is a heat-meltable developer (toner) made of, for example, a resin, a magnetic material, or a colorant. is there.

  The fixing roller 1 and the pressure roller 2 are arranged to face each other in parallel in the vertical direction, and both end sides thereof are rotatably supported by bearing members (not shown). The pressure roller 2 is elastically biased toward the shaft side of the fixing roller 1 by a pressure mechanism such as a spring (not shown), and is pressed against the lower surface of the fixing roller 1 with a predetermined pressure. Fixing nip portion N) is formed.

  The fixing roller 1 is rotationally driven at a predetermined peripheral speed in a counterclockwise direction indicated by an arrow by a driving mechanism such as a motor (not shown). The pressure roller 2 is rotated by the rotation of the fixing roller 1 by the pressure frictional force with the fixing roller 1 at the pressure nip N.

  The fixing roller 1 includes, in order from the inner side to the outer side in the radial direction, an annular support member 11, an annular heat insulating member 12, an annular electromagnetic induction heating member 13, an annular elastic member 14, and an annular release member 15. It consists of members. The roller hardness of the fixing roller 1 is, for example, an ASKER-C hardness of 30 to 90 degrees.

  As the support member 11, for example, an aluminum core cylinder having an outer diameter of 40 mm and a thickness of 3 mm is used. The support member 11 may be a heat-resistant molded pipe such as iron or PPS (polyphenylene sulfide), for example, as long as the strength of the material can be secured. However, the core metal generates heat. In order to prevent this, it is desirable to use a nonmagnetic material that is less affected by electromagnetic induction heating.

  The heat insulating member 12 is used for heat insulating and holding the electromagnetic induction heat generating member 13, and a heat-resistant and elastic sponge material (heat insulating structure) made of a rubber material or a resin material is used. Thus, by using a heat-resistant and elastic rubber or resin sponge (heat insulation structure) for the heat insulating member 12, the electromagnetic induction heat generating member 13 is reliably insulated and held, and the electromagnetic The deflection of the induction heat generating member 13 is allowed to increase the width dimension of the pressure nip portion N, and the roller hardness of the fixing roller 1 is made smaller than that of the pressure roller 2 so that the paper discharge performance and the recording material separation performance can be achieved. Can be improved. For example, when a silicon sponge material is used for the heat insulating member 12, the thickness is 2 to 10 mm, preferably 3 to 7 mm, and the hardness is set to 20 to 60 degrees, preferably 30 to 50 degrees with an Asker rubber hardness meter. And bonded with a primer if necessary.

  The electromagnetic induction heating member 13 is, for example, an endless nickel electroformed belt member having a thickness of 10 to 100 μm, desirably 20 to 50 μm. As another material of the electromagnetic induction heating member 13, a material having a relatively high magnetic permeability μ and an appropriate resistivity ρ such as a magnetic material (magnetic metal) such as magnetic stainless steel may be used. . Moreover, even if it is a nonmagnetic material, electroconductive materials, such as a metal, can be used by making a material into a thin film, for example. In addition, the electromagnetic induction heat generating member 13 may be a resin in which heat generating particles are dispersed, and by using a resin-based material for the electromagnetic induction heat generating member 13, the separability can be further improved. it can.

  In the electromagnetic induction heat generating member 13, an eddy current is generated by the magnetic flux of the magnetic flux generating means 3, and heat is generated by Joule heat, and the fixing roller 1 is heated by this heat generation. This heating is called electromagnetic induction heating.

  The elastic member 14 is made of a heat-resistant and elastic rubber material or resin material, and improves the adhesion between the recording material P and the surface of the fixing roller 1. As the elastic member 14, for example, a heat-resistant elastomer such as silicon rubber or fluorine rubber that can be used at a fixing temperature is used. Various fillers may be mixed in the elastic member 14 for the purpose of thermal conductivity, reinforcement, and the like. Examples of the thermally conductive particles include diamond, silver, copper, aluminum, marble, glass, and the like. Examples include silica, alumina, magnesium oxide, boron nitride, and beryllium oxide.

  The thickness of the elastic member 14 is, for example, preferably 10 to 800 μm, and more preferably 100 to 300 μm. When the thickness of the elastic member 14 is less than 10 μm, it becomes difficult to obtain elasticity in the thickness direction. On the other hand, when the thickness of the elastic member 14 exceeds 800 μm, the heat generated in the electromagnetic induction heating member 13 is It becomes difficult to reach the outer peripheral surface of the fixing roller 1, and the thermal efficiency tends to deteriorate.

  The hardness of the elastic member 14 is preferably 1 to 80 degrees, more preferably 5 to 30 degrees in terms of JIS hardness, and while preventing a decrease in strength and poor adhesion in the elastic member 14, an unfixed image (toner) It is possible to prevent the fixing problem of t. In this case, the elastic member 14 is preferably made of silicone rubber. Specifically, the silicone rubber is a one-component, two-component or three-component or more silicone rubber, LTV type, RTV type. Alternatively, HTV type silicon rubber, condensation type or addition type silicon rubber can be used. In this embodiment, the elastic member 14 is silicon rubber having a JIS hardness of 10 degrees and a thickness of 200 μm.

  The release member 15 enhances the releasability of the surface of the fixing roller 1, and can withstand use at a fixing temperature and has toner releasability. As the release member 15, for example, silicon rubber, fluororubber, or fluororesin such as PFA, PTFE, FEP, and PFEP is used. 5-100 micrometers is preferable and, as for the thickness of the said release member 15, 10-50 micrometers is more preferable. In addition, a conductive material, an abrasion resistant material, and a good heat conductive material may be added to the release member 15 as a filler. Moreover, in order to improve the adhesive force between members, you may perform the adhesion process by a primer etc.

  The pressure roller 2 includes, in order from the inner side to the outer side in the radial direction, an annular aluminum core bar 21 having an outer diameter of 20 mm and a thickness of 3 mm, an annular silicon sponge rubber member 22 having a thickness of 7 mm, and a thickness of 10 to 10 mm. It is comprised from three members with cyclic | annular fluororesin mold release members 23, such as 50 micrometers PTFE and PFA. Similar to the fixing roller 1, the release member 23 enhances the release property of the surface of the pressure roller 2.

  For example, iron or PPS (polyphenylene sulfide) can be used as the material of the core metal 21 as long as the strength is secured. However, in order to prevent the core metal from generating heat. It is desirable to use a nonmagnetic material that is less affected by electromagnetic induction heating. Instead of the silicon sponge rubber member 22, a solid rubber member may be provided to further improve the releasability.

  The pressure roller 2 is pressed against the fixing roller 1 with a load of 300 to 500 N. In this case, the nip width of the pressure nip N is about 5 to 10 mm. Of course, the nip width may be changed by changing the load.

  The magnetic flux generating means 3 includes an exciting coil 31 and a magnetic core 32, and is arranged outside the fixing roller 1 so as to face the fixing roller 1 and along the longitudinal direction of the fixing roller 1. Yes.

  The magnetic core 32 includes a coil bobbin 33 formed in a cup shape (trapezoidal shape) whose cross section is a downward opening, and a cover member 34 that covers the coil bobbin 33 with a predetermined gap. The magnetic core 32 is a long member having a length dimension substantially corresponding to the axial dimension of the fixing roller 1, and covers substantially half of the cross section of the fixing roller 1 inside the coil bobbin 33. .

  The exciting coil 31 is present in a gap between the coil bobbin 33 and the cover member 34 and is configured by winding a conductive wire around the coil bobbin 33. The excitation coil 31 is connected to the high frequency converter 4 and supplied with high frequency power of 100 to 2000 [W]. For this reason, the exciting coil 31 is a litz wire in which several tens to several hundreds of thin wires are bundled and covered with a heat resistant resin in consideration of the case where heat is transferred to the winding. Use things.

  Since the coil bobbin 33 is disposed along the outer peripheral surface of the fixing roller 1, the heat generation efficiency of the fixing roller 1 can be increased. As the magnetic core 32, one having a high magnetic permeability and low loss is used. For example, when an alloy such as permalloy is used, the eddy current loss inside the magnetic core 32 increases at a high frequency. It may be structured.

  The magnetic core 32 is used for improving the efficiency of the magnetic circuit and for magnetic shielding. The magnetic circuit portions of the exciting coil 31 and the magnetic core 32 may be air cores (no core) if there is a means that can sufficiently shield the magnetic field. Further, when a resin material in which magnetic powder is dispersed is used, the magnetic permeability is relatively low, but the shape can be freely set.

  An AC current of 10 to 100 [kHz] is applied to the excitation coil 31 by the high frequency converter 4. The magnetic flux induced by the alternating current passes through the electromagnetic induction heat generating member 13 of the fixing roller 1, and an eddy current flows through the electromagnetic induction heat generating member 13, so that the electromagnetic induction heat generating member 13 itself generates Joule heat. The fixing roller 1 is heated by the heat generated by the electromagnetic induction heating member 13.

  A temperature sensor 6 is disposed so as to contact the surface of the fixing roller 1. The temperature sensor 6 is a thermistor, for example, and detects the surface temperature of the fixing roller 1.

  A control circuit 6 is connected to the temperature sensor 6, and the control circuit 6 controls the heating and temperature control of the fixing roller 1 based on the surface temperature detection signal of the fixing roller 1 input from the temperature sensor 6. Control. Specifically, the control circuit 5 controls the high-frequency converter 4 based on a signal from the temperature sensor 6, and increases or decreases the power supply to the exciting coil 31 by the high-frequency converter 4. The surface temperature of the fixing roller 1 is automatically controlled so as to become a predetermined constant temperature.

  Next, the operation of the fixing device will be described. The fixing roller 1 is rotationally driven, and the pressure roller 2 is also driven to rotate. Further, the electromagnetic induction heat generating member 13 of the fixing roller 1 generates electromagnetic induction heat by the action of the magnetic flux generated by the magnetic flux generating means 3, and the surface temperature of the fixing roller 1 becomes a predetermined constant temperature. Automatically controlled. Then, the recording material (paper) P carrying the unfixed (toner) image t conveyed from the image forming means (not shown) is formed in the pressure nip portion N between the fixing roller 1 and the pressure roller 2. be introduced. In this case, the side of the recording material P on which the unfixed image t is formed faces the fixing roller 1.

  The recording material P introduced into the pressure nip N is nipped and conveyed through the pressure nip N and heated by the fixing roller 1 so that the unfixed image t is melted and fixed on the recording material P.

  The recording material P that has passed through the pressure nip N is separated from the fixing roller 1 and discharged and conveyed. A separation claw 8 is disposed so as to contact the surface of the fixing roller 1. The separation claw 8 forces the recording material P from the surface of the fixing roller 1 when the recording material P sticks to the surface of the fixing roller 1 after passing through the pressure nip N. To prevent paper jamming (jamming).

  Further, the fixing roller 1 will be described. The fixing roller 1 is configured such that the heat insulating member 12 and the electromagnetic induction heating member 13 are disposed only at both ends in the axial direction, as shown in the plan view of the developed state in FIG. And an adhesive 16 that adheres to each other. In FIG. 2, the radially outer member of the electromagnetic induction heating member 13 is not shown.

  More specifically, the adhesive 16 is present in a predetermined range from the end surface of the fixing roller 1 to the inner side in the width direction, and forms an annular adhesive region Z having a predetermined width. The adhesive 16 is continuous in the circumferential direction of the fixing roller 1.

  As this adhesive 16, for example, it is preferable to use a silicon-based adhesive or a fluorine rubber primer. Specifically, as the fluoro rubber primer, fluoro rubbers such as VDF-HFP, VDF-HFP-TFE, VDF-PFP, VDF-PFP-TFE, VDF-PFMVE-TFE, VDF-CTFE, etc. Is used.

  According to the fixing roller 1 having this configuration, since the non-adhesive region W without the adhesive 16 exists at the center in the width direction, the heat insulating member 12 and the electromagnetic induction heat generating member having different elastic modulus and thermal expansion coefficient. 13, even if a difference in deformation amount occurs during use, the difference in deformation amount can be absorbed by the non-adhesive region W, and between the heat insulating member 12 and the electromagnetic induction heating member 13. The durability can be improved by preventing adhesion peeling and plastic deformation of the electromagnetic induction heating member 13. Further, since the adhesive 16 is present on the entire circumference of the fixing roller 1, toner, dust and the like are prevented from entering between the heat insulating member 12 and the electromagnetic induction heating member 13. The adhesion between the heat insulating member 12 and the electromagnetic induction heating member 13 can be strengthened.

  If the non-bonded region W does not exist, the electromagnetic induction heating member 13 is made of metal or a heat-resistant resin containing metal, and thus has high hardness, and the heat insulating member 12 and the electromagnetic induction heating member 13 As the amount of deformation differs, peeling easily occurs. Further, when peeling does not occur, the electromagnetic induction heating member 13 may be deformed by expansion and contraction of the heat insulating member 12. Once the electromagnetic induction heat generating member 13 is deformed, it is poor in flexibility, so even if the temperature state is restored, the electromagnetic induction heating member 13 is not restored to the original state but is damaged.

  The width of the adhesive region Z should be ½ or less, preferably ３ or less of the entire width of the fixing roller 1, and the electromagnetic induction heating member 13 can be reliably prevented from peeling and deforming. . That is, when the bonding region Z exceeds the upper limit value, it is difficult to obtain the effect of preventing the electromagnetic induction heating member 13 from being peeled off and preventing deformation.

  Further, according to the fixing device having the above-described configuration, since the fixing roller 1 is provided, troubles such as repair, replacement, and management of the fixing roller 1 can be saved, and costs relating to maintenance management and the like can be reduced as a whole. .

  Further, according to the fixing device having the above configuration, the heat capacity of the electromagnetic induction heating member 13 that contributes to heat generation and generates eddy current is small, and the electromagnetic induction heating member 13 is insulated and held by the heat insulating member 12. For this reason, the elastic member 14 or the release member 15 on the outer peripheral side of the fixing roller 1 is acted to quickly heat so that the surface of the fixing roller 1 quickly reaches the temperature required for fixing. . Further, even if heat is taken away by the recording material P such as paper or an OHP sheet, the supply of heat can catch up.

  Further, by utilizing the flexibility of the electromagnetic induction heat generating member 13 itself held and insulated by the heat insulating member 12, the formation of the pressure nip N between the fixing roller 1 and the pressure roller 2 is described above. Even if the elastic member 14 of the fixing roller 1 is made as thin as 200 μm, a nip having a width larger than before can be formed, no micro gloss is generated, and a recording material (media) that is easy to be wound around the fixing roller 1 such as OHP paper. ) A sufficient separation performance can be secured even for P.

  Next, a method for manufacturing the fixing roller 1 will be described. Here, a method of assembling the heat insulating member 12 and the electromagnetic induction heat generating member 13 will be described, and description of other members will be omitted.

  First, the adhesive 16 is applied to one axial end portion of the outer peripheral surface of the annular heat insulating member 12, and one axial end portion of the inner peripheral surface of the annular electromagnetic induction heating member 13 is applied. The adhesive 16 is applied (this is referred to as an adhesive application process).

  Thereafter, the adhesive 16 of the annular heat insulating member 12 is introduced into the annular electromagnetic induction heating member 13 from the other end side of the annular electromagnetic induction heating member 13 where the adhesive 16 is not applied. The annular heat insulating member 12 is inserted from the other uncoated end side, and the heat insulating member 12 and the electromagnetic induction heating member 13 are bonded (this is referred to as an adhesion step).

  According to this manufacturing method, since the heat insulating member 12 and the electromagnetic induction heat generating member 13 are overlapped from the side where the adhesive 16 is not applied, the adhesive 16 is placed in the center in the axial direction. Without spreading, the heat insulating member 12 and the electromagnetic induction heat generating member 13 can be reliably bonded only at both ends. Thus, the fixing roller 1 can be reliably manufactured by a simple process.

(Second Embodiment)
FIG. 3 shows another embodiment of the fixing roller of the present invention. In the fixing roller 1, the annular release member 15 has an annular sheet passing area A that opposes the recording material (not shown) in the central portion in the axial direction, and the adhesive 16 has the sheet passing area. It is located on the outer side in the axial direction from A and does not overlap the paper passing area A in the radial direction. The sheet passing area A contacts the recording material P (shown in FIG. 1A), and the width of the sheet passing area A is substantially the same as the width of the recording material (preset). Since other structures are the same as those of the first embodiment, description thereof is omitted.

  According to the fixing roller 1 having this configuration, the adhesive 16 overlaps the annular non-sheet passing area that does not face the recording material and does not overlap the sheet passing area A. Transmission and pressure fluctuations do not have an adverse effect on the image of the recording material, and a good image quality can be obtained. If the boundary between the adhesive region Z where the adhesive 16 is present and the non-adhesive region W where the adhesive 16 is not present overlaps with the paper passing region A, a difference occurs in the state of heat transfer and pressure. It will have a negative effect.

(Third embodiment)
FIG. 4 shows another embodiment of the fixing roller of the present invention. In the fixing roller 1, the annular electromagnetic induction heat generating member 13 has an annular heat generation region B in the center portion in the axial direction, and the adhesive 16 is located outside the heat generation region B in the axial direction. And does not overlap with the heat generating region B in the radial direction. The heat generating area B is an area facing the exciting coil 31 (shown in FIG. 1A), and the heat generating area B is wider than the paper passing area A. Since other structures are the same as those of the first embodiment, description thereof is omitted.

  According to the fixing roller 1 having this configuration, since the adhesive 16 does not overlap the heat generating region B, the adhesive 16 is removed from the high temperature region, and the influence on heat is kept low and durability is kept high. Can do. If the adhesive 16 overlaps the heat generating area B, the heat generating area B increases the temperature of the adhesive 16 and adversely affects the adhesiveness.

  More specifically, in the case of a fixing device with a paper size of A3, if a paper having a small size such as A4 is passed, the temperature at the end of the fixing roller 1 rises and adversely affects the adhesiveness. . However, in the present invention, since the adhesive region Z does not overlap the heat generating region B, the adhesiveness of the fixing roller 1 can be improved and the durability can be improved.

(Fourth embodiment)
FIG. 5 is a simplified configuration diagram showing an embodiment of the image forming apparatus according to the present invention. The image forming apparatus includes an image forming unit 40 that forms the unfixed image t on the recording material P, and the fixing device 10 of the invention that melts and fixes the unfixed image t on the recording material P.

  More specifically, the image forming apparatus shown in FIG. 5 is an electrophotographic 4-color printer. The image forming means 40 includes an electrophotographic photosensitive drum (image carrier) 41 made of an organic photosensitive member, a charging device 42 (such as a charging roller) that performs a predetermined charging process on the photosensitive drum 41, and the photosensitive member. A light emitting device (laser scanner) 43 for irradiating the body drum 41 with laser light L, a four-color developing device 44 for developing the photosensitive drum 41, and an image formed on the photosensitive drum 41 are transferred. An intermediate transfer drum 45 and a transfer roller 46 for transferring the image transferred to the intermediate transfer drum 45 to the recording material P.

  The photosensitive drum 41 is rotationally driven in a clockwise direction indicated by an arrow at a predetermined process speed (circumferential speed), and is subjected to a charging process with a predetermined polarity and potential from the charging device 42 in the rotating process. The charged surface is subjected to scanning exposure processing of target image information by the laser light L output from the light emitting device 43.

  The light emitting device 43 outputs a laser beam L modulated (on / off) corresponding to a time-series electric digital pixel signal of target image information from an image signal generating device such as an image reading device (not shown), and the photosensitive device The peripheral surface of the body drum 41 is scanned and exposed. By this scanning exposure, an electrostatic latent image corresponding to the target image information subjected to the scanning exposure is formed on the peripheral surface of the photosensitive drum 41.

  In the case of full-color image formation, first, scanning exposure and latent image formation are performed on a first color separation component image (for example, yellow component image), and the latent image is converted into a yellow developing device of the four-color developing device 44. The yellow toner image is developed by the operation 44a. The yellow toner image is transferred to the peripheral surface of the intermediate transfer drum 45 by contact between the photosensitive drum 41 and the intermediate transfer drum 45.

  After the toner image on the peripheral surface of the photoconductive drum 41 is transferred to the peripheral surface of the intermediate transfer drum 45, the peripheral surface of the photoconductive drum 41 is adhered to the peripheral surface of the photoconductive drum 41 by a cleaner 47. Is removed and cleaned.

  Such a process cycle of charging, scanning exposure, development, primary transfer and cleaning is performed by the second color separation component image (for example, the magenta component image, the magenta developing unit 44b is activated), the third color separation component image (for example, , Cyan component image, cyan developing device 44c), and fourth color separation component image (for example, black component image, black developing device 44d) are sequentially executed and the intermediate transfer drum 45 is rotated. Four color toner images of a yellow toner image, a magenta toner image, a cyan toner image, and a black toner image are sequentially superimposed and transferred onto the surface, and a color image corresponding to the target full-color image is synthesized and formed.

  The intermediate transfer drum 45 has, for example, a medium-resistance elastic member and a high-resistance surface layer on the peripheral surface of a metal drum. The intermediate transfer drum 45 is in contact with or in close proximity to the photoconductor drum 41. The toner image on the side of the photoconductive drum 41 is moved to the intermediate position by the potential difference with the photoconductive drum 41 by applying a bias potential to the metal drum at a rotational speed in the counterclockwise direction indicated by an arrow at substantially the same peripheral speed. Transfer is performed on the peripheral surface side of the transfer drum 45.

  The color toner image synthesized and formed on the peripheral surface of the intermediate transfer drum 45 is sent between the intermediate transfer drum 45 and the transfer roller 46 at a predetermined timing from a paper supply unit (not shown). It is transferred onto one surface of the material (transfer material) P. The transfer roller 46 sequentially transfers the composite color toner image from the intermediate transfer drum 45 to the recording material P side by supplying charges having the opposite polarity to the toner from the other surface of the recording material P. .

  The recording material P onto which the image (the unfixed image t) has been transferred is separated from the peripheral surface of the intermediate transfer drum 45 and introduced into the fixing device 10 to perform a heat fixing process on the unfixed image t. Upon receipt, the color image formed product is discharged to a discharge tray (not shown) outside the apparatus.

  After the toner image on the peripheral surface of the intermediate transfer drum 45 is transferred to the recording material P, the peripheral surface of the intermediate transfer drum 45 is adhered to the transfer residual toner, paper powder, etc. by the cleaner 48. Residues are removed and cleaned.

  According to the image forming apparatus having the above-described configuration, since the fixing device 10 of the present invention is provided, troubles such as repair, replacement, and management of the fixing roller 1 of the fixing device 10 can be saved. Costs related to management can be reduced.

  The present invention is not limited to the above-described embodiment. For example, in the fixing roller 1, the adhesive 16 is discontinuous in the circumferential direction, and the material of the adhesive 16 is omitted, thereby reducing the cost. The difference in deformation between the heat insulating member 12 and the electromagnetic induction heat generating member 13 may be further absorbed to improve durability.

1 is a cross-sectional configuration diagram showing an embodiment of a fixing device of the present invention. FIG. 3 is an enlarged cross-sectional view of a main part showing a developed state of the fixing roller of the present invention. FIG. 4 is a plan view showing a developed state of the fixing roller of the present invention. FIG. 6 is a developed plan view showing another embodiment of the fixing roller of the present invention. FIG. 6 is a developed plan view showing another embodiment of the fixing roller of the present invention. 1 is a simplified configuration diagram illustrating an image forming apparatus of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Fixing roller 2 Pressure roller 3 Magnetic flux generation means 10 Fixing device 11 Support member 12 Heat insulation member 13 Electromagnetic induction heat generating member 14 Elastic member 15 Release member 16 Adhesive 40 Image forming means A Paper passing area B Heat generating area P Recording material t Unfixed image

Claims (6)

An electromagnetic induction heating type fixing roller for melting and fixing the unfixed image on a recording material carrying an unfixed image,
An annular support member, an annular heat insulating member, an annular electromagnetic induction heating member, an annular elastic member, and an annular release member, which are arranged in order from the radially inner side to the outer side;
A fixing roller comprising: an adhesive that adheres the heat insulating member and the electromagnetic induction heating member to each other only at both ends in an axial direction. The fixing roller according to claim 1,
The annular release member has an annular sheet passing region facing the recording material at the axial center.
The fixing roller, wherein the adhesive is positioned outside in the axial direction with respect to the paper passing area and does not overlap the paper passing area in the radial direction. The fixing roller according to claim 1,
The annular electromagnetic induction heating member has an annular heating region at the axial center.
The fixing roller, wherein the adhesive is positioned on an outer side in the axial direction with respect to the heat generation area and does not overlap the heat generation area in the radial direction. A fixing roller according to any one of claims 1 to 3,
A pressure roller that sandwiches and conveys the recording material together with the fixing roller;
And a magnetic flux generating means disposed outside the fixing roller and generating magnetic flux to generate heat from the electromagnetic induction heating member of the fixing roller. An image forming means for forming an unfixed image on the recording material;
An image forming apparatus comprising: the fixing device according to claim 4, wherein the unfixed image is fused and fixed on the recording material. Adhesive is applied to one axial end of the outer peripheral surface of the annular heat insulating member, and adhesive is applied to one axial end of the inner peripheral surface of the annular electromagnetic induction heating member Process,
From the other end of the annular electromagnetic induction heating member to which the adhesive is not applied, the other end of the annular heat insulating member to which the adhesive is not applied in the annular electromagnetic induction heating member. A fixing roller manufacturing method comprising: an adhesive step of inserting the annular heat insulating member from the portion side and bonding the heat insulating member and the electromagnetic induction heating member.

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