JP2002108124A - Method for molding rotating member for electromagnetic induction fixing, and fixing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fixing device for quick start fixing whose durability is improved by uniformizing the distribution of magnetic particles to prevent degradation by local heat generation and which can perform instant heating while obtaining a high pyrogenic effect by defining proper physical conditions of the magnetic particles in a magnetic and elastic pyrogenic layer. SOLUTION: A rotating member for electromagnetic induction fixing having a roll shape is formed by providing a cylindrical thermally conductive base body having an electromagnetic induction heating body and a magnetic elastic pyrogenic layer outside the thermally conductive base body. The magnetic elastic pyrogenic layer is formed by dispersing the spherical magnetic particles into the layer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of molding a rotating member for electromagnetic induction fixing of an induction heating type fixing device used for image formation such as a copying machine, a printer and a facsimile, and uses the rotating member for electromagnetic induction fixing. The present invention relates to a fixing device capable of quick start.

[0002]

2. Description of the Related Art Conventionally, as a fixing device used in an image forming apparatus such as a copying machine, a printer, a facsimile, etc., a soft heat roller fixing method having a rubber layer on a core metal as a stable one having a high technical perfection. However, it is widely used in full-color machines from low-speed machines to high-speed machines.

However, in a conventional soft heat roller fixing type fixing device, when a transfer material or toner is heated,
It is necessary to heat a fixing roller having a low thermal conductivity and a large heat capacity, so that the energy effect is poor and energy saving is disadvantageous. In addition, it takes a long time to warm up the fixing device at the time of printing, and a printing time (warming up time). There is a problem that becomes longer.

[0004] To solve this, the present inventors have proposed:
As a method for heating from the roller surface layer side, a rubber material layer (magnetic elastic heating layer) containing magnetic particles is provided on the outer peripheral surface of a cylindrical base (thermally conductive base), and a roller member for fixing (for electromagnetic induction fixing) is provided. (Rotating member), and the lines of magnetic force from the electromagnetic induction heating body provided inside the cylindrical heat conductive base,
Japanese Patent Application No. 2000-12 discloses a fixing method for inductively heating a magnetoelastic heating layer and fixing a toner image by heat of the magnetoelastic heating layer.
No. 8917.

[0005]

However, a rubber material layer containing magnetic particles (magnetic elastic heating layer) on the outer peripheral surface of a cylindrical substrate (thermally conductive substrate) proposed in Japanese Patent Application No. 2000-128917. ) To form a fixing roller member (rotating member for electromagnetic induction fixing), inductively heating the magnetic elastic heating layer by lines of magnetic force from the electromagnetic induction heating body, and fixing the toner image by the heat of the magnetic elastic heating layer. In the fixing method and the like, energy saving and a quick start with a shortened warm-up time were achieved, but depending on the physical conditions of the magnetic particles in the magnetoelastic heating layer, a high heat generation effect could not be obtained or the dispersion of the magnetic particles was The problem is that the durability is short due to unevenness and deterioration due to local heat generation.

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems, specifies proper physical property conditions of magnetic particles in a magnetoelastic heating layer, obtains a high heat generation effect, and achieves uniform dispersion of magnetic particles.
It is a first object of the present invention to provide a fixing device for quick start fixing capable of preventing deterioration due to local heat generation and improving durability and capable of instantaneous heating.

Further, in the above-mentioned proposed rotating member for electromagnetic induction fixing in which the magnetic elastic heating layer is induction-heated by the magnetic field lines from the electromagnetic induction heating element, the rubber material layer (magnetic elastic heating layer) having poor heat conduction is heated. Therefore, the temperature of the magnetoelastic heating layer immediately below the electromagnetic induction heater is high, the temperature of the rotating member for electromagnetic induction fixing is not isotropic, the temperature distribution is uneven, and the fixing unevenness and the deterioration of the magnetoelastic heating layer are deteriorated. The problem that arises arises.

The present invention also solves the above-mentioned problems, makes the temperature of the rotating member for electromagnetic induction fixing isotropic, suppresses uneven temperature distribution, and prevents occurrence of uneven fixing and deterioration of the magnetoelastic heating layer. A second object is to provide a fixing device.

In the above-mentioned proposed rotating member for electromagnetic induction fixing, in which the magnetic elastic heating layer is induction-heated by the lines of magnetic force from the electromagnetic induction heating element, the specific gravity of the magnetic particles is large. When dispersing the magnetic particles in the elastic heating layer, there is a problem that the magnetic particles are biased downward, and a problem arises in that uniform induction heating cannot be achieved. For this reason, the use of the electromagnetic induction fixing rotating member causes a problem that fixing unevenness occurs. In addition, there is an outflow of heat to the heat conductive substrate, and sufficient fixing performance cannot be obtained.

The present invention solves the above problems and provides a method of molding a rotating member for electromagnetic induction fixing, which prevents uneven distribution of magnetic particles in a magnetoelastic heating layer during crosslinking during molding. It is a third object of the present invention to provide a fixing device capable of preventing uneven distribution of magnetic particles in a magnetoelastic heating layer and uniforming heat during induction heating.

[0011]

A first object of the present invention is to provide a fixing device for fixing a toner image on a transfer material to the transfer material by heating and pressurizing, wherein a cylindrical heat conductive member having an electromagnetic induction heating element is provided. A magnetic elastic heating layer is provided on the outside of the thermally conductive substrate to form a roll-shaped rotating member for electromagnetic induction fixing, and the magnetic elastic heating layer has spherical magnetic particles dispersed in the layer. And a fixing device for fixing the toner image on the transfer material to the transfer material by applying heat and pressure to the transfer material. A cylindrical heat conductive substrate having
A magnetic elastic heating layer is provided on the outside of the heat conductive base to form a roll-shaped rotating member for electromagnetic induction fixing, and the magnetic elastic heating layer contains magnetic particles having a particle size of 50 to 500 μm in the layer. An electromagnetic induction heating element in a fixing device (second invention) characterized by being formed in a dispersed manner and a fixing device for fixing a toner image on a transfer material to the transfer material by heating and pressing. A cylindrical heat conductive substrate having:
A magnetic elastic heating layer is provided outside the heat conductive substrate to form a roll-shaped rotating member for electromagnetic induction fixing, and the magnetic elastic heating layer has a volume resistivity of 10 ⁻³ Ω · cm or less. (Third invention) wherein magnetic particles having a characteristic property are dispersed in a layer, and a toner image on the transfer material is fixed to the transfer material by heating and pressing. In the fixing device, a cylindrical heat conductive base having an electromagnetic induction heating body, and a magnetic elastic heating layer provided on the outside of the heat conductive base to form a roll-shaped rotating member for electromagnetic induction fixing, The magnetization of the magnetoelastic heating layer has a magnetization of 50 emu /
g of magnetic particles dispersed in the layer (fourth invention), and fixing the toner image on the transfer material to the transfer material by heating and pressing In the fixing device, a cylindrical heat conductive base having an electromagnetic induction heating body, and a magnetic elastic heating layer provided outside the heat conductive base to form a roll-shaped rotating member for electromagnetic induction fixing, The magnetoelastic heating layer has a volume ratio of 10 to 50.
% Of the magnetic particles dispersed in the layer is achieved by the fixing device (fifth invention).

A second object of the present invention is to provide a fixing device for fixing a toner image on a transfer material to the transfer material by heating and pressing, wherein a cylindrical heat conductive base having an electromagnetic induction heating element; A magnetic elastic heating layer is provided outside the heat conductive substrate to form a roll-shaped electromagnetic induction fixing rotating member, and the electromagnetic induction fixing rotating member is heated by induction heating in a rotated state. This is achieved by a fixing device (sixth invention) that performs temperature control of a fixing rotating member.

A third object of the present invention is to provide a method for molding a rotating member for electromagnetic induction fixing having a magnetic elastic heating layer in which magnetic particles are mixed in a rubber material layer, wherein the rubber material layer has at least a certain period of time during crosslinking. A method of forming a rotating member for electromagnetic induction fixing (seventh invention), wherein the rotating member is rotated about an axis of the rotating member for electromagnetic induction fixing, and a method of heating and pressing a toner image on a transfer material. In the fixing device fixed to the transfer material, a cylindrical heat conductive base having an electromagnetic induction heating body, and a magnetoelastic heat generating layer containing magnetic particles provided outside the heat conductive base are provided in a roll shape. A fixing device for forming an electromagnetic induction fixing rotating member, wherein the density of the magnetic particles in the magnetoelastic heating layer is increased as approaching the outer peripheral surface of the electromagnetic induction fixing rotating member. 8 shots ) Is achieved by.

[0014]

Embodiments of the present invention will be described below. Note that the description in this column does not limit the technical scope of the claims and the meaning of terms. Also, the following assertive description in the embodiment of the present invention indicates the best mode, and does not limit the meaning of the terms of the present invention or the technical scope.

An image forming process and each mechanism of an embodiment of an image forming apparatus using a fixing device according to the present invention will be described with reference to FIGS. FIG. 1 is a cross-sectional configuration view of a color image forming apparatus showing an embodiment of an image forming apparatus using a fixing device according to the present invention, and FIG. 2 is a side cross-sectional view of the image forming body of FIG. 3 is an explanatory view showing the structure of the fixing device. FIG. 4 is an enlarged sectional configuration view of the electromagnetic induction fixing rotating member of FIG. 3, and FIG. 5 is a magnetoelastic heating layer of the electromagnetic induction fixing rotating member. FIG. 6 is a diagram showing an outer diameter and a thickness of a heat conductive substrate of a rotating member for electromagnetic induction fixing, and FIG.
It is a figure which shows the other example of arrangement | positioning of the electromagnetic induction heating body which heats the rotating member for electromagnetic induction fixing.

According to FIG. 1 or FIG. 2, a photosensitive drum 10, which is an image forming body, is provided on the outer periphery of a cylindrical base formed of a light-transmitting member such as glass or light-transmitting acrylic resin. It is formed by forming a photoconductive layer and a photoconductor layer of an organic photosensitive layer (OPC).

The photosensitive drum 10 is rotated clockwise as indicated by an arrow in FIG. 1 with power of a drive source (not shown) in a state where the light-transmitting conductive layer is grounded.

In the present invention, the exposure beam for image exposure is
The photoconductor layer of the photoconductor drum 10, which is the image forming point, only needs to have an exposure light amount of a wavelength that can provide an appropriate contrast with respect to the light attenuation characteristic (photocarrier generation) of the photoconductor layer. . Therefore, the light transmittance of the light-transmitting substrate of the photosensitive drum in the present embodiment does not need to be 100%, and may have a characteristic of absorbing a certain amount of light when transmitting the exposure beam. . The point is that any suitable contrast can be provided. As a material of the light-transmitting substrate, an acrylic resin, particularly one obtained by polymerizing a methyl methacrylate monomer, is preferably used because of its excellent light-transmitting properties, strength, accuracy, surface properties, etc. Various translucent resins such as acryl, fluorine, polyester, polycarbonate, polyethylene terephthalate and the like used for the above can be used. Further, as long as it has a light-transmitting property with respect to the exposure light, it may be colored. As the light-transmitting conductive layer, indium tin oxide (I
TO), tin oxide, lead oxide, indium oxide, copper iodide, or a metal thin film of Au, Ag, Ni, Al, or the like that maintains light transmissivity. Reactive deposition method, various sputtering methods, various CV
D method, dip coating method, spray coating method and the like can be used.
Various organic photosensitive layers (OPC) can be used as the photoconductor layer.

The organic photosensitive layer serving as the photosensitive layer of the photoconductor layer includes a charge generation layer (CGL) mainly composed of a charge generation substance (CGM) and a charge transport layer (CTM) mainly composed of a charge transport substance (CTM). And CTL). An organic photosensitive layer having a two-layer structure has high durability as an organic photosensitive layer due to its thick CTL and is suitable for the present invention.
The organic photosensitive layer may have a single layer structure containing a charge generation material (CGM) and a charge transport material (CTM) in one layer. ,
Usually, a binder resin is contained.

A scorotron charger 11 as charging means described below, and an exposure optical system 1 as image writing means
2. The developing device 13 as a developing unit is prepared for an image forming process for each color of yellow (Y), magenta (M), cyan (C) and black (K), respectively. Are arranged in the order of Y, M, C, and K with respect to the rotation direction of the photosensitive drum 10 indicated by the arrow in FIG.

Scorotron charger 11 as charging means
Is mounted so as to face and be close to the photosensitive drum 10 in a direction perpendicular to the moving direction of the photosensitive drum 10 as an image forming body (the direction perpendicular to the plane of FIG. 1). A control grid (no symbol) maintained at a predetermined potential with respect to the body layer;
As a, for example, a sawtooth electrode is used, and a charging action (in this embodiment, negative charging) is performed by corona discharge having the same polarity as that of the toner, thereby giving a uniform potential to the photosensitive drum 10. As the corona discharge electrode 11a, a wire electrode or a needle electrode may be used.

The exposure optical system 12 for each color is a linear exposure element (LED) in which a plurality of LEDs (light emitting diodes) as light emitting elements for image exposure light are arranged in an array parallel to the axis of the photosensitive drum 10. (Not shown) and a selfoc lens (not shown) as an equal-magnification imaging element are configured as an exposure unit attached to a holder. An exposure optical system 1 for each color is placed on a cylindrical holder 20 as an exposure optical system holding member.
2 is mounted and housed inside the substrate of the photosensitive drum 10. Other exposure elements include FL (phosphor emission),
A linear element in which a plurality of light emitting elements such as EL (electroluminescence) and PL (plasma discharge) are arranged in an array is used.

An exposure optical system 12 as an image writing means for each color sets an exposure position on the photosensitive drum 10 between the scorotron charger 11 and the developing device 13 and the developing device 13 with respect to the photosensitive member. It is arranged inside the photoconductor drum 10 in a state provided on the upstream side in the rotation direction of the drum 10.

The exposure optical system 12 performs image processing based on image data of each color sent from a separate computer (not shown) and stored in a memory, and then forms an image on a uniformly charged photosensitive drum 10. Exposure is performed to form a latent image on the photosensitive drum 10. The emission wavelength of the light-emitting element used in this embodiment is usually 6 for the toners of Y, M, and C, which have high light transmittance.
The wavelength in the range of 80 to 900 nm is good, but the wavelength may be shorter than this, since the color toner does not have sufficient translucency since image exposure is performed from the back surface.

The developing device 13 as a developing means for each color includes
Inside yellow (Y), magenta (M), cyan (C)
Alternatively, it contains a black (K) two-component (or one-component) developer and is formed of, for example, a cylindrical non-magnetic stainless steel or aluminum material having a thickness of 0.5 to 1 mm and an outer diameter of 15 to 25 mm, respectively. And a developing sleeve 13a as a developer carrier.

In the developing area, the developing sleeve 13a is kept out of contact with the photosensitive drum 10 with a predetermined gap, for example, 100 to 1000 μm, by abutting rollers (not shown). At the closest position, it rotates in the forward direction, and at the time of development, an AC voltage AC is superimposed on a DC voltage of the same polarity as the toner (in the present embodiment, a negative polarity) or a DC voltage with respect to the developing sleeve 13a. By applying the developing bias voltage, non-contact reversal development is performed on the exposed portion of the photosensitive drum 10. At this time, the precision of the development interval needs to be about 20 μm or less in order to prevent image unevenness.

As described above, the developing device 13 transfers the electrostatic latent image formed on the photosensitive drum 10 formed by the charging by the scorotron charger 11 and the image exposure by the exposure optical system 12 in a non-contact state. Reversal development is performed with toner having the same polarity as the charge polarity of No. 10 (in the present embodiment, the photosensitive drum is negatively charged, and the toner has negative polarity).

As shown in FIG. 2, the photosensitive drum 10 and a holder 20 as an exposure optical system holding member rotatably support the photosensitive drum 10 at the rear and front ends of the apparatus. Drum flanges 10A and 10B as photoconductor drum support members, and optical system flanges 120A and 1 as exposure optical system support members that support holder 20
20B is integrally formed through press-fitting or means such as screws. The photoreceptor drum 10 includes a drum flange 10A and a drum flange 10B serving as a photoreceptor drum support member and an optical system flange 120A of the holder 20.
Shaft 121 and optical system flange 1 integrated with each other
20B is rotatably supported via bearings B1 and B2, respectively.

The shaft 121 has a shaft portion 121A for holding the photoreceptor drum 10, and a support shaft 130 as a shaft holding means having an engagement hole 130A is provided on the rear device board 70. The linear bearing B4 is fitted into the engagement hole 130A, and the receiving member 13
The support shaft 130 is fixed to the device substrate 70 on the rear side by screws or the like with the Oa interposed therebetween. The support shaft 130 is located at the center of the gear G2 that meshes with the drive gear G1, and rotatably supports a conductive member 131 that integrates the gear G2 via a bearing B3. On the other hand, the apparatus substrate 70 on the front side of the apparatus has an opening 70A through which the photosensitive drum 10 having the exposure optical system 12 fixed to the holder 20 can be inserted and removed.

The holder 20 inserts the shaft portion 121A of the shaft 121 into the linear bearing B4 provided on the support shaft 130 with respect to the device board 70 on the back side, and the shaft portion 121A
The engaging pin 121P inserted into the
The exposure optical system 12 is attached by regulating the angular relation position of the exposure optical system 12 by engaging with a V-shaped groove formed on the front side of the exposure optical system 12. With the optical system flange 120C as a support member sandwiching the cushioning material K and pressing the front lid 120D in the axial direction, the screw 5
2 to be mounted at a predetermined position.

A coupling 10C attached to a side surface of a drum flange 10A as a photosensitive drum supporting member for supporting the photosensitive drum 10, a drive pin 131A attached to a side surface of a conductive member 131 integrated with a gear G2;
With the set screw 51, the drum flange 10A and the gear G
When the photosensitive drum 10 with the holder 20 is integrated, the drum flange 1
Coupling 10C attached to the side of 0A is gear G2.
After the engagement, the conductive member 131 having the gear G2 and the photosensitive drum 10 having the drum flange 10A are aligned with the center and the outer peripheral surface. , From the side of the photosensitive drum 10 using the set screw 51
1A and the coupling 10C are fixed, and the drum flange 10A and the gear G2 are connected and fixed.

When the image forming body drive motor (not shown) is started by the start of the image formation, the rotational power of the drive gear G1 is transmitted to the photosensitive drum 10 via the connecting portion by the gear G2, and the photosensitive drum 10 is moved to the position shown in FIG. , And at the same time, application of a potential to the photosensitive drum 10 is started by the charging action of the Y scorotron charger 11.
After a potential is applied to the photosensitive drum 10, exposure (image writing) by a first color signal, that is, an electrical signal corresponding to Y image data is started in the Y exposure optical system 12, and the rotation of the photosensitive drum 10 is started. By scanning, an electrostatic latent image corresponding to the yellow (Y) image of the original image is formed on the photosensitive layer on the surface. This latent image is reversely developed in a non-contact state by the Y developing device 13, and a yellow (Y) toner image is formed on the photosensitive drum 10.

Next, the photoreceptor drum 10 places an M scorotron charger 11 on the yellow (Y) toner image.
A potential is applied by the charging action of the M exposure optical system 12
Exposure (image writing) is performed using an electrical signal corresponding to the second color signal of m, i.e., magenta (M) image data.
The magenta (M) toner image is formed on the yellow (Y) toner image by non-contact reversal development by the developing device 13.

According to the same process, the cyan (C) toner image corresponding to the third color signal is further obtained by the C scorotron charger 11, the exposure optical system 12 and the developing device 13, and the K scorotron charger 11. , Exposure optical system 1
A black (K) toner image corresponding to the fourth color signal is sequentially superimposed and formed by the second and developing units 13, and a color toner image is formed on the peripheral surface within one rotation of the photosensitive drum 10. You.

As described above, in this embodiment, Y, M,
The exposure of the organic photosensitive layer of the photoconductor drum 10 by the C and K exposure optical systems 12 is performed through a transparent substrate from the inside of the photoconductor drum 10. Therefore, the exposure of the image corresponding to the second, third, and fourth color signals can form an electrostatic latent image without being shielded by the previously formed toner image, which is preferable. Photoconductor drum 1
0 may be exposed from outside.

On the other hand, the recording paper P as a transfer material is sent out from a paper feed cassette 15 as a transfer material storage means by a feed roller (no code), fed by a feed roller (no code), and is fed by a timing roller. It is conveyed to 16.

The recording paper P is synchronized with the color toner image carried on the photosensitive drum 10 by the driving of the timing roller 16, and the paper charging device 1 as a paper charging means is synchronized.
Due to the electrification of 50, the toner is attracted to the conveyor belt 14a and fed to the transfer area. The recording paper P, which is closely transported by the transport belt 14a, is moved around the photosensitive drum 10 by a transfer unit 14c as a transfer unit to which a voltage having a polarity opposite to that of the toner (positive polarity in the present embodiment) is applied in a transfer area. The color toner images on the surface are collectively transferred to the recording paper P.

The recording paper P on which the color toner image has been transferred is
The paper is discharged by a paper separation AC neutralizer 14h as a transfer material separating unit, separated from the transport belt 14a, and transported to the fixing device 17.

The fixing device 17 includes a pair of a magnetic fixing roller 17a as an upper roll-shaped electromagnetic induction fixing rotating member (fixing roller member) for fixing a color toner image, and a pair of the upper magnetic fixing roller 17a. And a fixing roller 47a as a lower roll-shaped fixing member.
Inside the upper magnetic fixing roller 17a, an electromagnetic induction heating unit 170 as an electromagnetic induction heating body that emits lines of magnetic force by electromagnetic induction and heats the magnetic fixing roller 17a is disposed.

Magnetic fixing roller 17a and fixing roller 47a
The recording paper P is sandwiched by a nip portion N formed between
By applying heat and pressure, the color toner image on the recording paper P is fixed, and the recording paper P is sent by the paper discharge roller 18 and discharged to a tray on the upper portion of the apparatus.

The toner remaining on the peripheral surface of the photosensitive drum 10 after the transfer is transferred to a cleaning blade 19 provided in a cleaning device 19 as an image forming body cleaning means.
Cleaning is performed by a. The photosensitive drum 10 from which the residual toner has been removed is uniformly charged by the scorotron charger 11, and enters the next image forming cycle.

As shown in FIG. 3, a fixing device 17 is a roll-shaped rotating member for electromagnetic induction fixing (fixing roller member) having an upper elasticity for fixing a toner image on a transfer material.
And a lower fixing roller 47a serving as a lower roll-shaped fixing member, which is paired with the upper magnetic fixing roller 17a, and is provided between the elastic magnetic fixing roller 17a and the fixing roller 47a. The recording paper P is sandwiched by a nip portion N having a width of about 5 to 20 mm formed by the process described above, and heat and pressure are applied to fix the toner image on the recording paper P. A magnetic fixing roller 17a as a roll-shaped rotating member for electromagnetic induction fixing provided on the upper side has a rotation direction of the magnetic fixing roller 17a from the position of the nip portion N.
Fixing separation claw TR3, fixing oil cleaning roller TR
1. An oil application roller T provided with a heat equalizing roller TR4 and an oil application roller TR2, and winding a felt member impregnated with oil around a cylindrical aluminum pipe or paper tube.
Oil is applied to the magnetic fixing roller 17a by R2. The oil on the peripheral surface of the magnetic fixing roller 17a is cleaned by the fixing oil cleaning roller TR1. The transfer material after fixing is separated by the fixing separation claw TR3. The heat generation temperature distribution on the peripheral surface of the magnetic fixing roller 17a heated by the magnetic elastic heating layer 171b by the heat equalizing roller TR4 using a metal roller member having good thermal conductivity such as an aluminum material or a stainless steel or a heat pipe is used. Be uniformed. The temperature uniformity of the magnetic fixing roller 17a in the vertical and horizontal directions due to the passage of the transfer material is equalized by the heat equalizing roller TR4.

A magnetic fixing roller 17a provided on the upper side and serving as a rotating member for electromagnetic induction fixing (fixing roller member) for fixing a toner image on a transfer material includes a cylindrical heat conductive base 171a (inside). Substrate) and the thermally conductive substrate 1
An elastic heat insulating layer 171d having high elasticity, a magnetic elastic heat generating layer 171b (surface heat generating layer) in which magnetic particles JR are mixed, and a protective layer 171c are provided in this order outside the outer diameter 71a.
It is configured as a soft roller of about 50 mm. Inside the magnetic fixing roller 17a, an electromagnetic induction heating unit 170 as an electromagnetic induction heating body for heating the magnetic fixing roller 17a is provided. The electromagnetic induction heating unit 170
An AC magnetic field H is formed inside the magnetoelastic heating layer 171b by a magnetic core JNa and an excitation heating coil section CLa wound around the magnetic core JNa, and magnetic lines of magnetic force emitted from the electromagnetic induction heating unit 170 form a magnetic field. The elastic heating layer 171b is heated. Electromagnetic induction heating unit 1
The magnetic elastic heating layer 171b is heated by an alternating magnetic field H formed inside by the lines of magnetic force emitted from 70, thereby forming a roll-shaped electromagnetic induction fixing rotating member capable of rapid heating. That is, the rotating member for electromagnetic induction fixing according to the present invention applies an electric current to the excitation heating coil portion CLa, and generates an alternating magnetic field H of about 0.5 to 50 kHz inside the magnetic elastic heating layer 171b by the magnetic force lines emitted from the magnetic core JNa. The eddy current inside the magnetoelastic heating layer 171b generated by the alternating magnetic field H heats the magnetoelastic heating layer 171b. As will be described in detail later, the elastic heat insulating layer 171d having high elasticity allows the magnetic fixing roller 17a configured as a soft roller to fix a good color toner image.

As shown in FIG. 7, the magnetic fixing roller 17a as a rotating member for electromagnetic induction fixing (fixing roller member) for fixing the toner image on the transfer material has been described with reference to FIG. Similarly, the cylindrical heat conductive substrate 171
a (inner base), a highly elastic heat insulating layer 171d having a high elasticity outside the heat conductive base 171a, a magnetic elastic heating layer 171b (surface heating layer) in which magnetic particles JR are mixed, and a protective layer 171c. A magnetic fixing roller 17a is provided as a soft roller having an outer diameter of about 25 to 50 mm and is provided as a rotating member for electromagnetic induction fixing (a fixing roller member).
, An electromagnetic induction heating unit 170A including a magnetic core JNb and an excitation heating coil portion CLb wound around the magnetic core JNb may be provided. An alternating magnetic field H of about 0.5 to 50 kHz is formed inside the magnetoelastic heating layer 171b by magnetic lines of force generated from the electromagnetic induction heating unit 170A disposed outside the magnetic fixing roller 17a, and the magnetoelastic heating layer 171b is heated. Is done.

A fixing roller 47 serving as a lower roll-shaped fixing member that is paired with the upper magnetic fixing roller 17a.
a is, for example, a metal core 471a using an aluminum material, and a sponge-like thickness (thickness) using, for example, a silicon rubber layer or a fluorine rubber layer, or a silicon rubber foam material on the outer peripheral surface of the metal core 471a. ) 5-20mm thick, rubber hardness 10H
s to 40 Hs (JIS, A rubber hardness), a rubber roller layer 471 b formed of a thick rubber layer, and an outer diameter of 25 to 50
It is configured as a soft roller of about mm. PFA having releasability on the outer side (outer peripheral surface) of the rubber roller layer 471b,
Tube made of heat-resistant fluororesin such as PTFA (not shown)
May be covered. An elastic rubber roller having high heat insulating property is used for the lower roll-shaped fixing member to prevent diffusion of heat from the upper rotating member for electromagnetic induction fixing to the lower fixing member, and to secure a wide nip width. Further, a heat equalizing roller TR4 using a metal roller member having good thermal conductivity, such as an aluminum material or a stainless steel material, which is in contact with the surface of the rubber roller 471b and is driven to rotate, is provided, and is fixed by the heat uniformizing roller TR4. The heat generation temperature distribution on the peripheral surface of the roller 47a is made uniform. As the heat equalizing roller TR4, it is preferable to use a heat pipe that has both heat storage and heat radiation. Of course, the upper magnetic fixing roller 17 of the present invention
The same configuration as a may be used for the lower fixing member.

A flat nip portion N is formed between the upper soft roller and the lower soft roller to fix the toner image.

TS1 is a non-contact type temperature sensor which is provided at a predetermined interval outside the upper magnetic fixing roller 17a and is a temperature detecting means for performing temperature control, and TS2 is a lower fixing roller 47a. A non-contact type temperature sensor which is a temperature detecting means for performing temperature control, which is provided at a predetermined interval outside the device. As the temperature sensors TS1 and TS2, besides a non-contact type, for example, a contact type using a thermistor can also be used.

According to FIG. 4, the configuration of the magnetic fixing roller 17a has a thickness of 0.5 mm as a cylindrical heat conductive substrate 171a (internal substrate) as shown in a cross section in FIG. ~
Aluminum material (thickness: 2.38 J / cm · s · K, volume resistivity: 2 × 10 ⁻⁸ Ω · cm) with good thermal conductivity and 3 mm thick, transmitting magnetic lines of force and non-magnetic stainless steel (Thermal conductivity is 0.25 J / cm · s · K, volume resistivity is up to 5 × 1
0 ⁻⁸ Ω · cm) is mainly used. As described above,
The heat conductive base 171a is made of a non-magnetic material having a relatively small thickness and good heat conductivity.

The elastic heat insulating layer 171d has a thickness (thickness) of 0.1 mm.
For example, silicon rubber (having a thermal conductivity of 1 × 10 ⁻³ J / cm · s ·) having a thickness of 2 to 2 mm, preferably 0.5 to 1.5 mm
K) or fluoro rubber (having a thermal conductivity of 5 × 10 ^-4 J / cm · s)
-A base rubber (base layer) such as K) is used, and is formed of a base rubber as an elastic polymer material that transmits magnetic lines of force and transmits magnetic lines of magnetic force. As the elastic heat insulating layer 171d, in order to cope with a high speed, heat conduction is performed by mixing a powder of a metal oxide such as silica, alumina, magnesium oxide or the like as a filler with a base rubber (silicon rubber or fluorine rubber) as an elastic polymer material. It is preferable to use a base layer having a thermal conductivity of (1 to 10) × 10 ⁻³ J / cm · s · K. The base layer has a thermal conductivity of an aluminum material (a thermal conductivity of 2.38 J / cm · s · K) or a non-magnetic stainless material (a thermal conductivity of 0.25 J / cm · s · K).
And lower than the heat conductive substrate 171a using the heat conductive layer 171a to serve as a heat insulating layer. The thermal conductivity of the elastic heat insulating layer 171d is preferably １ ／ or less, and more preferably 1/10 or less, of the thermal conductivity of the thermally conductive substrate 171a. The preferred rubber hardness of the elastic heat-insulating layer 171d is 5 to 60 Hs.

Magnetoelastic heating layer 171b (surface heating layer)
Is, for example, a silicone rubber (having a thermal conductivity of 1 × 10^-3J / c
m · s · K) or fluoro rubber (thermal conductivity 5 × 10^-FourJ /
cm · s · K) etc. as an elastic polymer material (binder)
In the base rubber (in the rubber liquid that makes up the base rubber)
Ferromagnetic of metals such as iron, chromium, nickel, cobalt
Magnetic particles JR composed of fine particles of the body, and volume resistivity
To adjust the Ketchen EC Black, Carb
olacl, Vulcan-XC72, acetylene bra
And conductive carbon black such as rubber
For, silica, alumina, mug oxide as filler
Mix with powder of metal oxide such as nesium and mix.
Volume resistivity of the viscoelastic heating layer 171b is 10⁰Ω
cm or less, preferably 10^-3Ω · cm or less
Disperse, thickness (wall thickness) 0.3-4mm, preferably
One having a thickness of 0.5 to 3 mm is used. Magnetoelastic heating layer 17
The magnetic particles JR mixed in the rubber solution 1b include iron
Powder particles are preferably used, but depending on the production method, reduced iron
Powder, atomized iron powder, iron nitride powder, etc. Reduced iron
Since powder and iron nitride powder are irregular, they must be spheroidized
Is preferred. Also, to prevent rust, iron powder particles must be slightly acidified beforehand.
Surface to enhance dispersibility with rubber liquid before hydration and polymerization
It is preferable to perform a treatment. Also, iron powder particles are low
It is preferable because it is a resistor and has a large magnetization. Magnetic fixing law
Electromagnetic induction heating unit provided inside or outside the
From the knit 170 or the electromagnetic induction heating unit 170A
Due to the generated magnetic lines of force, the inside of the magnetoelastic heating layer 171b is
To an alternating magnetic field H of about 0.5 to 50 kHz
More heated. In order to respond to high-speed operation,
Base rubber (silicone) formed with conductive carbon black
As a filler added to rubber and fluoro rubber)
Of metal oxides such as silica, alumina and magnesium oxide
The method of improving thermal conductivity by powder is adopted.
Is (2-20) × 10 ^-3Magnetic bullet of about J / cm · s · K
It is preferable to use the conductive heating layer 171b. Magnetic materials and conductive
Generally, rubber hardness is high when carbon black etc.
For example, 40Hs usually has 60H
s (JIS, A rubber hardness).
The preferred rubber hardness of the magnetoelastic heating layer 171b is 5 to 60.
Hs. As described above, the magnetoelastic heating layer 171b is
Formed as a magnetic material, generates heat near the surface layer and generates magnetic elasticity
It is possible to speed up the temperature rise of the thermal layer 171b. Blend
The inserted magnetic material and filler are
As in the case of the rack, those having good conductivity are preferable. Do so
As a result, the electric resistance (volume resistance) of the magnetoelastic heating layer 171b is increased.
Resistance) can easily be set low, as in the previous value.
Wear. The above-described conductive material is also used for the elastic heat insulating layer 171d described above.
It is possible to mix carbon black and filler to the same extent.
Wear.

In the above description, the AC magnetic field H formed inside the magnetoelastic heating layer 171b by the magnetic field lines generated from the electromagnetic induction heating unit 170 in the configuration of FIG. 3 or the electromagnetic induction heating unit 170A in the configuration of FIG. So that the magnetoelastic heating layer 171b is effectively heated by
In order to shorten the distance between the electromagnetic induction heating unit 170 or the electromagnetic induction heating unit 170A and the magnetic elastic heating layer 171b, it is preferable to set the thickness of the heat conductive base 171a and the elastic heat insulating layer 171d thin. Further, by providing the elastic heat insulating layer 171d having high heat insulating properties, heat generated in the magnetic elastic heat generating layer 171b is prevented from being transmitted to the lower layer side.

On the outer side (outer peripheral surface) of the magnetoelastic heating layer 171b, a thickness of 20 to 1 to improve the releasability from the toner.
20 μm PFA (fluororesin) tube or fluororesin (PFA or PTFE) paint
Protective layer 1 having a thermal conductivity of ( ^{3 to} 100) × 10 ⁻³ J / cm · s · K, which is formed by coating silicon rubber or fluorine rubber having a layer thickness of 20 to 500 μm or a layer having a thickness of 20 to 500 μm.
71c is provided.

As shown in FIG. 4B, the elastic heat insulating layer 171d described above with reference to FIG.
It is also possible to form a magnetic elastic heating layer 171b on the outside (outer peripheral surface) of the heat conductive substrate 171a to form an elastic roll-shaped rotating member for electromagnetic induction fixing, which is generally of this type. Is used.

Referring to FIG. 5, the dotted line (a-1) shows the concentration distribution of the above-described magnetic particles JR in the magnetic elastic heating layer 171b of the magnetic fixing roller 17a as a roll-shaped rotating member for electromagnetic induction fixing. When the heat is distributed uniformly, the heat generation distribution of the magnetic elastic heat generating layer 171b is such that heat is concentrated at the magnetic elastic heat generating layer 171b at the boundary as shown by the curve (b-1), and the elastic heat insulating layer 171d (or heat). Conductive substrate 1
Since heat easily flows out to the side 71a), it is preferable to provide a concentration distribution and generate heat inside the magnetoelastic heating layer 171b from the viewpoint of dispersing the heat distribution. For this reason, as shown by the dotted line (a-2) in the concentration distribution of the magnetoelastic heat generating layer 171b, the interface on the side of the insulated elastic heat insulating layer 171d (or the heat conductive base 171a) is reduced in concentration toward the outer peripheral surface side. Increasing the height and increasing the height in front of the outer peripheral surface (to the thickness t2 of the magnetoelastic heat generating layer 171b, the elastic heat insulating layer 171d
(Or thermal conductive substrate 171a) from the side to 1/2/3/5
(Position of about degree) so as to obtain a concentration that absorbs 100% so as to be saturated. Thereby, the magnetoelastic heating layer 17
As shown in curve (b-2), the heat generation distribution due to the lines of magnetic force at 1b is such that the maximum value of the magnetoelastic heating layer 171b is larger than the thickness t2 of the magnetoelastic heating layer 171b from the interface. 1/3 from the conductive substrate 171a) side
It is shifted so that it is located at about 2/5, and the outflow of heat is reduced. Further, as shown by a dotted line (a-3), it is preferable to form a saturated layer by providing an inclination.
As shown by the curve (b-3), the magnetoelastic heating layer 171b
Has a maximum value near the center of the magnetoelastic heating layer 171b, and has a parabolic shape with a minimum value near the interface and the outer peripheral surface of the magnetoelastic heating layer 171b, so that there is no influence of heat outflow. To do. Further, the concentration distribution of the magnetic particles JR is made as shown by a dotted line (a-4) by the molding method described in detail in the later embodiment, whereby the heat generation distribution of the magnetoelastic heating layer 171b is changed to a curve (b- It is still more preferable to make the same as shown in 3). In short, if the absorption is sufficiently performed inside, the influence of the concentration on the outside disappears. Further, it is also possible to provide the above-mentioned inclination in the concentration distribution of the magnetic particles JR and adjust the heat generation distribution by changing the inclination angle.

As shown in FIG. 6, the outer diameter φ of the cylindrical heat conductive substrate 171a of the magnetic fixing roller 17a as a roll-shaped rotating member for electromagnetic induction fixing is 15 to 4 mm.
A thickness of about 5 mm is used. As the thickness t1, a thicker one is better in terms of strength and a thinner one is better in terms of heat capacity. However, from the relationship between strength and heat capacity, a cylindrical heat conductive base 171 is used.
The relationship between the outer diameter φ of a and the thickness (wall thickness) t1 is 0.02 ≦ t1 / φ ≦ 0.20, preferably 0.04 ≦ t1 / φ ≦ 0.10. When the outer diameter φ of the heat conductive base 171a is 40 mm, the thickness t1 of the heat conductive base 171a is 0.8 mm ≦ t1.
≦ 8 mm, preferably 1.6 mm ≦ t1 ≦ 4.0 mm. T1 / φ on thermal conductive substrate 171a
Is less than 0.02, the strength is insufficient, and t1 / φ is 0.2
If it exceeds 0, the heat capacity increases and the magnetic fixing roller 17a
Heating is prolonged.

The use of the fixing device 17 described with reference to FIG. 3 makes it possible to provide a fixing device that is resistant to deformation at the fixing portion (nip portion) and that can perform quick start (rapid heating). The color toner is melted satisfactorily by the pressure in the soft fixing portion (nip portion) due to the elasticity of the rotating member and the heating by the magnetic elastic heating layer of the electromagnetic induction fixing rotating member. Start (rapid heating) fixing becomes possible. Also, an energy saving effect can be obtained. Further, a fixing device for quick start fixing capable of instantaneous heating is provided by a rotating member for electromagnetic induction fixing having a novel configuration.

Embodiment 1 However, the magnetoelastic heating layer 1 of the fixing device 17 described above is used.
In the case of 71b, although energy saving and a quick start in which the warm-up time was shortened were achieved, a high heating effect could not be obtained or the dispersion of the magnetic particles JR could not be obtained due to the physical property conditions of the magnetic particles JR in the magnetoelastic heating layer 171b. The durability is shortened due to unevenness and deterioration due to local heat generation in the magnetoelastic heating layer 171b.

To solve this problem, a high heat generation effect of the magnetoelastic heat generating layer 171b is obtained, the dispersion of the magnetic particles JR is made uniform, and the deterioration of the magnetic elastic heat generating layer 171b due to local heat generation is prevented to improve durability. The setting of appropriate physical property conditions of the magnetic particles JR in the magnetoelastic heat generating layer 171b to improve the quality will be described with reference to FIG. 8 and FIGS. 3, 4, and 7 described above. FIG. 8 is an explanatory diagram of the shape of the magnetic particles in the magnetoelastic heating layer.

As described above, the magnetoelastic heating layer 171b
Examples of the magnetic particles JR dispersed and mixed in a rubber liquid include ferromagnetic fine particles of a metal such as iron, chromium, nickel, and cobalt, particularly reduced iron powder, atomized iron powder, and iron nitride powder. Iron powder particles are preferably used,
First, it is preferable that the magnetic particles JR be subjected to a spheroidizing treatment. Magnetic particles JR with good response by AC magnetic field H
In order to change the direction of magnetization and generate a current, it is necessary that the magnetic particles JR have a small anisotropy when magnetized, and the magnetic particles JR mixed into the magnetoelastic heating layer 171b.
8A is preferably a spherical shape as shown in FIG. 8A, and the spherical (spherical) magnetic particles JR are combined with the magnetic elastic heating layer 1.
The magnetoelastic heating layer 171b dispersed and mixed in the layer 71b
Is preferably formed. The magnetic particles JR have a high magnetic permeability so as to be easily magnetized, and are preferably spherical. The spherical shape makes the AC magnetic field H uniform,
In addition, since the magnetic particles can be effectively incorporated into the magnetic particles JR, the heat generation efficiency increases. That is, the AC magnetic field H easily passes through the magnetic particles JR and easily generates heat. The circular arrows in the magnetic particles JR indicate the induced current flowing, and the flow of the induced current is large.
Large fever. Iron and nickel which are preferably used as the magnetic particles JR by being mixed into the magnetoelastic heating layer 171b include:
The material is smaller in magnetic anisotropy than cobalt, and is a preferable material. However, as shown in FIG. 8B, the shape is needle-like (flat).
In the case of, the longitudinal direction is easily magnetized, shape anisotropy occurs, and the AC magnetic field H is difficult to enter only from the long axis direction (it is difficult to be magnetized in a needle shape), and the AC magnetic field H cannot be effectively taken in. Heat generation efficiency decreases. That is, the alternating magnetic field H hardly passes through the magnetic particles JR, and hardly generates heat. The flow of the induced current in the magnetic particles JR indicated by the circular arrows is also small, and the heat generation is small. As shown in FIG. 8 (C), even if the flatness is large, the magnetic elastic heating layer 171b of the magnetic fixing roller 17a can be used.
If the magnetic particles JR are mixed in parallel with the roller shape, heat is easily generated.

In the above, the spherical shape of the magnetic particles JR means
It is obtained by particle size selection by a conventionally known average particle size selection means, is rounded without corners (edges), and has a ratio (flatness) of a major axis to a minor axis of 1/3 or less. A thing. As described above, the magnetic particles JR
To improve the dispersibility of the magnetic particles JR in the rubber liquid, and to prevent the aggregation of the magnetic particles JR in the rubber liquid. Therefore, when spherical particles having small shape anisotropy are used as the magnetic particles JR, the magnetoelastic heating layer 171b having small magnetic anisotropy can be easily formed even when dispersed.

Second, the diameter of the magnetic particles JR dispersed and mixed in the layer of the magnetoelastic heating layer 171b is 50 to 500.
It is preferable to use those having a particle size of about
It is more preferable to use one having a thickness of about 300 μm. The magnetic particles JR are placed in the layer of the magnetoelastic heating layer 171b.
It is desirable to mix a large amount and uniformly, but a larger particle size can be mixed in a larger amount with a smaller specific surface area, and the calorific value can be increased.
The particle size of the magnetic particles JR is set to 100 μm or more. In addition, since the smaller the particle size, the higher the uniformity, the magnetic particles JR
Is 500 μm or less. Further, the narrower the particle size distribution, the better the dispersibility and the difference in particle size causes local heat generation, thereby preventing local thermal damage from occurring in the magnetoelastic heat generating layer 171b.

Third, the volume resistivity of the magnetic particles JR dispersed and mixed in the layer of the magnetoelastic heating layer 171b is 10 to sufficiently generate an induced current due to the AC magnetic field H in the magnetic particles JR. It is preferably set to ⁻³ Ω · cm or less, and more preferably 10 ⁻⁵ Ω · cm or less. The lower the volume resistivity, the larger the value of the induced current and the higher the heat generation. For this reason, ferrite-based ferromagnetic fine particles of metals such as iron, chromium, nickel, and cobalt, particularly magnetic particles JR made of iron powder, which are relatively low in volume resistivity, are also possible.
Is preferably used. It is necessary that the volume resistivity of the magnetoelastic heating layer 171b is also low.
Conductive carbon, silver (Ag), nickel (Ni), copper (Cu) based metal filler, ITO, Sn
It is preferable to mix O ₂ , TiO ₂ , ZnO, etc. in the binder (base rubber). Thereby, an induced current is generated in the entire magnetoelastic heating layer 171b, and uniform heating is possible. The value of the volume resistivity of the magnetic particles JR is set at 1 kg / kg on the packed magnetic particles JR after tapping the magnetic particles JR in a container having a cross-sectional area of 0.05 cm ^2.
A load of cm ² is applied to adjust the amount of the magnetic particles JR to an appropriate amount, and the magnetic particles JR at this time have a thickness of about 1 mm. This is a value obtained by reading a current value when a voltage that generates an electric field of 10 to 100 V / cm is applied between the load and the bottom electrode. The lower the volume resistivity, the lower the excitation heating coil portion CLa When an AC voltage is applied to the magnetic particles JR, a large induced current is generated in the magnetic particles JR by the AC magnetic field H induced in the magnetic particles JR, and the magnetic elastic heating layer 17 is formed.
Increase the heat generation of 1b.

Fourth, the magnetization of the magnetic particles JR dispersed and mixed in the layer of the magnetoelastic heating layer 171b is 50 emu /
g or higher, more preferably 100 emu / g or higher. The larger the magnetization and the higher the relative permeability,
A large induced current is obtained. A ferrite-based material is also possible, but metal fine particles of iron or the like having a large specific gravity are preferable because of their large volume magnetization (for example, the saturation magnetization of iron is 150 to 250
emu / g).

Fifth, if the magnetic elastic heating layer 171b contains a large amount of magnetic particles JR as much as possible in terms of the elasticity and durability of the base rubber of silicon rubber or fluorine rubber, the calorific value increases. Therefore, the magnetoelastic heating layer 171
The amount of the magnetic particles JR dispersed and mixed in the layer b is 10 to 50% by volume in the magnetoelastic heating layer 171b.
The degree is preferably, and the mixing amount of 20 to 40% is more preferable. If the amount is less than 10%, the heat generation effect is lost. On the other hand, if the mixing amount exceeds 50%, the elasticity and durability of the base rubber are inferior. In addition to the magnetic particles JR, conductive carbon and silver (Ag), nickel (Ni), and copper (Cu) -based metal fillers finer than the magnetic particles JR are mixed into a binder (base rubber) to generate magnetoelastic heat. Layer 171
b of the magnetic elastic heating layer 171b
The rubber hardness is adjusted to be less than the mixing amount of the magnetic particles JR, and is preferably about 5 to 15% by volume in the magnetoelastic heating layer 171b. If the amount of the metal filler mixed is too large, the rubber elasticity of the magnetoelastic heat generating layer 171b increases, and the elasticity is lost.

The magnetoelastic heat generating layer 171b provided with the first to fifth physical property conditions contains a large amount of magnetic particles JR, and the layer is brittle and weak, and the releasability and elasticity are reduced. The outer surface of the layer 171b is preferably formed as a rubber layer containing no magnetic material, a PFA tube, or the like (the protective layer 171c described above with reference to FIG. 4).

As described above, appropriate physical property conditions of the magnetic particles in the magnetoelastic heat generating layer are defined, a high heat generating effect is obtained, the dispersion of the magnetic particles is made uniform, and deterioration due to local heat generation is prevented. It is possible to provide a fixing device for quick start fixing that can improve durability and can instantaneously heat.

Embodiment 2 In addition, the magnetic field lines from the electromagnetic induction heating body proposed above provide:
In the electromagnetic induction fixing rotating member for induction heating the magnetoelastic heating layer, a rubber material layer with poor heat conduction (magnetic elastic heating layer)
Because the temperature of the magnetoelastic heating layer immediately below the electromagnetic induction heating element is high, the temperature of the rotating member for electromagnetic induction fixing is not isotropic, and the temperature distribution is uneven, and uneven fixing and magnetoelastic heating Layer degradation occurs.

FIG. 9 or FIG. 10 shows the driving and heating control of the electromagnetic induction fixing rotating member for preventing this.
This will be described with reference to FIG. FIG. 9 is a side sectional view of the fixing device for explaining driving and heating control of the electromagnetic induction fixing rotating member, and FIG. 10 is a temperature control block diagram of the fixing device of FIG.

According to FIG. 9 or FIG. 10 and FIG. 3 described above, the magnetic fixing roller 17a, which is a rotating member for electromagnetic induction fixing of the fixing device 17, has a heat conductive base 171a and an outer (outer peripheral surface) thereof. A magnetoelastic heating layer 171b containing the magnetic particles JR and a protective layer 171c are provided in this order, and the heat generation layer 171b is formed in parallel with the central axis of the cylindrical heat conductive base 171a using a non-magnetic metal member. Conductive substrate 171a
A resin flange JF1 using a resin member such as a heat-resistant polyimide resin or polyphenylene sulfide resin (PPS resin) as a holding member for the heat conductive substrate is provided at both ends of the outer peripheral surface of the substrate. The resin flange JF1 having a large coefficient of thermal expansion provided at the outer (outer peripheral surface) end of the heat conductive base 171a receives thermal expansion during heating of the heat conductive base 171a. An induction heating fixing roller bearing B5, which is a bearing member of a rotating member for electromagnetic induction fixing, which is press-fitted into a bearing holder BH1, is fitted into a resin flange JF1 as a holding member of a heat conductive base, and the magnetic fixing roller 1 is fixed.
7a is rotatably held. At this time, the induction heating fixing roller bearing B5 as the bearing member of the electromagnetic induction fixing rotating member is directly provided on the end of the heat conductive base 171a without providing the resin flange JF1 as the holding member for the heat conductive base. The configuration may be such that it is fitted to hold the heat conductive base 171a of the magnetic fixing roller 17a. At both ends of the magnetic fixing roller 17a, receiving plates PLa made of a resin member having good slipperiness, for example, using a fluororesin or the like are provided, and the magnetic fixing roller 17a is positioned from both ends. Inside the magnetic fixing roller 17a, there is a magnetic fixing roller 17a.
And a magnetic core JN for heating the magnetic core JN
an electromagnetic induction heating unit 1 as an electromagnetic induction heating body constituted by an excitation heating coil portion CLa wound around a
70 are arranged while being held by holders HD at both ends. An alternating magnetic field H (see FIG. 3, not shown in FIG. 9) is formed inside the magnetoelastic heating layer 171 b by lines of magnetic force emitted from the electromagnetic induction heating unit 170, and the magnetoelastic heating layer 171 b is heated.

A metal core 471a is provided in a pair with the upper magnetic fixing roller 17a.
a rubber roller layer 4 made of, for example, a silicon material
The lower fixing roller 47a as a fixing member in the form of a roll is formed by the upper magnetic fixing roller 1b.
7a, the core 471a is fitted into the bearing B6 which is pressed into the bearing holder BH2,
The fixing roller 47a is rotatably held. A gear G provided at one end of the core metal 471a of the fixing roller 47a
is rotated by the driving of the fixing driving motor Ma, the fixing roller 47a is driven and rotated, and the magnetic fixing roller 17a is driven and rotated.

The recording paper P is sandwiched by a nip portion N having a width of about 5 to 20 mm formed between the magnetic fixing roller 17a having elasticity and the fixing roller 47a, and heat and pressure are applied to the recording material P on the transfer material. Is fixed.

A non-contact type temperature sensor TS1 serving as temperature detecting means for performing temperature control is provided on the upper magnetic fixing roller 17a, and a non-contact type temperature sensor serving as temperature detecting means for performing temperature control is provided. The sensor TS2 is provided on the lower fixing roller 47a.

In the above configuration, as shown in FIG.
For example, at the time of printing start or warm-up by a print signal (print command), the fixing drive motor M
a of the electromagnetic heating unit 170 of the electromagnetic induction heating unit 170 while the magnetic fixing roller 17a is rotated.
La is brought into the operating state, and the magnetic elastic heating layer 171b of the magnetic fixing roller 17a is induction-heated. Induction heating of the magnetic fixing roller 17a is performed by the temperature sensor TS1 so that the predetermined temperature is stored in the ROM of the storage unit, and temperature control of the magnetic fixing roller 17a is performed. In FIG. 3 described above, the magnetoelastic heating layer 171b is connected to the heat conductive base 171.
Since the heat insulating property is increased so that no heat leaks out to a, the side of the excitation heating coil section CLa indicated by the dotted-line circle under induction heating is located on the side of the magnetic fixing roller 17a of the magnetoelastic heating layer 171b. In the stopped state, the temperature of the magnetic fixing roller 17a is locally high, but this rotation makes the temperature unevenness uniform. Also, when warming up,
Since the local heating is performed and a quick temperature rise is desired, the magnetic fixing roller 17a is rotated to make the temperature distribution uniform. At the time of printing and also during standby from standstill, rapid heating is performed in the same manner while rotating. Further, at the time of suspension, the magnetic fixing roller 17a may be maintained at a low temperature. Therefore, in a state where the rotation of the fixing driving motor Ma is stopped and the rotation of the magnetic fixing roller 17a is stopped, the input power is reduced and the temperature sensor TS1 is stopped. , The set temperature of the magnetic fixing roller 17a is reduced. At this time, even if local heating is performed, the input power is small and the heat can be sufficiently diffused.

As described above, it is possible to provide a fixing device in which the temperature of the electromagnetic induction fixing rotating member is made isotropic, the unevenness of the temperature distribution is suppressed, and the fixing unevenness and the deterioration of the magnetic elastic heating layer are reduced.

Embodiment 3 The magnetic field lines from the electromagnetic induction heating body proposed above provide
In the electromagnetic induction fixing rotating member for induction heating the magnetic elastic heating layer, the specific gravity of the magnetic particles is large, so that when the magnetic particles are dispersed in the magnetic elastic heating layer at the time of crosslinking during molding, the magnetic particles move downward. There is a problem in that the induction heating is not uniform, and a problem arises in that the induction heating cannot be made uniform. Therefore, when the electromagnetic induction fixing rotating member is used, fixing unevenness occurs.

A method of molding a rotating member for electromagnetic induction fixing to prevent this will be described with reference to FIG. 11 and FIG. 5 described above. FIG. 11 is a diagram showing a method of molding the rotating member for electromagnetic induction fixing.

According to FIG. 11 and FIG. 5 described above, FIG.
As shown in FIG. 1, the method of forming the rotating member for electromagnetic induction fixing is as follows.
A slot S on one end of the coating flange TRa is provided on inner wall surfaces (inner peripheral surfaces) at both ends of the cylindrical heat conductive base 171a.
Insert cylindrical holding part HG provided with L (chuck)
After that, a flange mold TRb as a mold for joining the coating flange TRa and the cylindrical mold KG is fitted into the other end of the coating flange TRa, and a PFA (perfluoroalkoxy) tube is used on the outer peripheral surface. It is set on the cylindrical mold KG to which the protective layer 171c is attached. One flange mold TRb having an inlet CH for injecting the rubber liquid is provided with a heat conductive base 171 attached to the application flange TRa.
a into the cylindrical mold KG, and then apply the coating flange TRa.
Fit into.

From the injection port CH provided on one side of the flange mold TRb fitted into the heated cylindrical mold KG, a magnetoelastic heating layer 171b as a rubber material layer is formed.
Is heated and cooled after the rubber liquid mixed with the magnetic particles JR is filled to form. At this time, the cylindrical mold KG is kept in a horizontal state from the time when the rubber liquid is filled until the crosslinking, and thereafter, as shown by the arrow in FIG.
The magnetic fixing roller 17a for each G is rotated about an axis for at least a certain time, for example, about 30 minutes, to eliminate the bias of the internal magnetic particles JR due to gravity. As a result, the influence of gravity becomes uniform around the axis, so that the magnetic particles JR are rotationally symmetrically distributed around the axis of the magnetic fixing roller 17a, and the concentration distribution of the magnetic particles JR in the magnetic elastic heating layer 171b is By increasing the rotation speed, the curve (a-4) in FIG.
The density of the magnetic particles JR increases as the surface is closer to the surface of the magnetic fixing roller 17a (as it approaches the outer peripheral surface). If the rotational speed of the magnetic fixing roller 17a is increased when the rubber material layer is crosslinked, the magnetic particles JR
Is unevenly distributed near the surface (near the outer peripheral surface) and the surface (outer peripheral surface)
It is possible to form a rotating member for electromagnetic induction fixing having the highest density of the magnetic particles JR. At this time, the rotation speed of the cylindrical mold KG is appropriately selected depending on the size of the magnetic fixing roller 17a, the physical properties of the rubber material layer, the physical properties of the magnetic particles JR, and the like.
After cooling, after the flange mold TRb at both ends is removed,
The molded magnetic fixing roller 17a, which is a rotating member for electromagnetic induction fixing, is extracted from the cylindrical mold KG, and both ends of the magnetic elastic heating layer 171b are cut.
By removing Ra, the magnetic fixing roller 17a is formed.

A heat conductive substrate 171a and a magnetoelastic heating layer 171 containing magnetic particles JR on the outside (outer peripheral surface) thereof
b and the protective layer 171c are provided in that order to form the magnetic fixing roller 17a.

As described above, the magnetic fixing roller 17a
And a rotating member for electromagnetic induction fixing that generates heat symmetrically about the axis of the magnetic fixing roller 17a. An induction current flows through the magnetic particles JR due to an alternating magnetic field H generated by passing an alternating current through the coil portion CLa (see FIG. 3, not shown in FIG. 11), and the magnetoelastic heating layer 171 of the magnetic fixing roller 17 a.
b is induction heated. Magnetic particles JR are magnetic fixing roller 1
Since the heat is distributed symmetrically around the axis of 7a, heat is generated evenly, and non-uniformity in fixability and gloss at the time of fixing by the magnetic fixing roller 17a is eliminated.

As described above, it is possible to provide a method of molding a rotating member for electromagnetic induction fixing, which prevents uneven distribution of magnetic particles in the magnetoelastic heating layer at the time of crosslinking during molding. The uneven distribution of the magnetic particles can be prevented, the heat during induction heating can be made uniform, and a fixing device having uniform fixability and gloss can be provided.

[0082]

According to the first to sixth aspects, appropriate physical property conditions of the magnetic particles in the magnetoelastic heating layer are defined, a high heat generation effect is obtained, the dispersion of the magnetic particles is made uniform, and the local It is possible to provide a fixing device for quick start fixing that prevents deterioration due to excessive heat generation, improves durability, and allows instantaneous heating.

According to the seventh to tenth aspects of the present invention, there is provided a fixing device in which the temperature of the electromagnetic induction fixing rotary member is made isotropic, the temperature distribution is suppressed from being uneven, and the fixing unevenness and the deterioration of the magnetoelastic heating layer are reduced. Becomes possible.

According to the eleventh aspect, it is possible to provide a method of molding a rotating member for electromagnetic induction fixing, which prevents uneven distribution of magnetic particles in the magnetoelastic heating layer during crosslinking during molding.

According to the twelfth aspect, the uneven distribution of the magnetic particles in the magnetoelastic heating layer is prevented, the heat during induction heating is made uniform, and the fixability and gloss are made uniform. The fixing device can be provided.

[Brief description of the drawings]

FIG. 1 is a sectional view of a color image forming apparatus showing an embodiment of an image forming apparatus using a fixing device according to the present invention.

FIG. 2 is a side sectional view of the image forming body of FIG. 1;

FIG. 3 is an explanatory diagram illustrating a structure of a fixing device.

FIG. 4 is an enlarged cross-sectional configuration diagram of a roll-shaped electromagnetic induction fixing rotating member of FIG. 3;

FIG. 5 is a diagram showing a magnetic material concentration distribution of a magnetoelastic heating layer of a rotating member for electromagnetic induction fixing.

FIG. 6 is a diagram showing an outer diameter and a thickness of a heat conductive substrate of the rotating member for electromagnetic induction fixing.

FIG. 7 is a view showing another arrangement example of the electromagnetic induction heating body for heating the rotating member for electromagnetic induction fixing.

FIG. 8 is an explanatory diagram of the shape of magnetic particles in a magnetoelastic heating layer.

FIG. 9 is a side sectional view of the fixing device for explaining driving and heating control of the electromagnetic induction fixing rotating member.

10 is a temperature control block diagram of the fixing device of FIG.

FIG. 11 is a diagram showing a method of molding a rotating member for electromagnetic induction fixing.

[Explanation of symbols]

 REFERENCE SIGNS LIST 10 photoconductor drum 11 scorotron charger 12 exposure optical system 13 developing device 17 fixing device 17a magnetic fixing roller 47a fixing roller 170, 170A electromagnetic induction heating unit 171a heat conductive substrate 171b magnetic elastic heating layer 171c protective layer 171d elastic heat insulating layer B5 Induction heating fixing roller bearing CLa, CLb Excitation heating coil section JNa, JNb Magnetic core JR Magnetic particles KG Cylindrical mold Ma Fixing drive motor P Recording paper TRa Coating flange TRb Flange mold

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI theme coat ゛ (reference) F16C 13/00 F16C 13/00 BE H05B6 / 14 H05B 6/14 Fterm (reference) 2H033 AA23 AA30 BA25 BA30 BB04 BB08 BB18 BB37 BE06 CA03 CA04 CA05 CA07 CA28 CA30 CA32. AC33 AD03 AD05 CD44 CD75 CD77

Claims (12)

[Claims] 1. A fixing device for fixing a toner image on a transfer material to the transfer material by applying heat and pressure, comprising: a cylindrical heat-conductive substrate having an electromagnetic induction heating element; And a magnetic elastic heating layer provided thereon to form a roll-shaped rotating member for electromagnetic induction fixing, wherein the magnetic elastic heating layer is formed by dispersing spherical magnetic particles in the layer. Fixing device. 2. A fixing device for fixing a toner image on a transfer material to the transfer material by applying heat and pressure, comprising: a cylindrical heat-conductive substrate having an electromagnetic induction heating element; And a magnetic elastic heat generating layer provided thereon to form a roll-shaped rotating member for electromagnetic induction fixing, and the magnetic elastic heat generating layer is formed by dispersing magnetic particles having a particle size of 50 to 500 μm in the layer. A fixing device characterized by the above-mentioned. 3. A fixing device for fixing a toner image on a transfer material to the transfer material by heating and pressurizing, wherein: a cylindrical heat conductive substrate having an electromagnetic induction heating body; A magnetic elastic heat generating layer is formed on the magnetic elastic heat generating layer to form a roll-shaped rotating member for electromagnetic induction fixing. The magnetic elastic heat generating layer contains conductive magnetic particles having a volume resistivity of 10 ⁻³ Ω · cm or less. A fixing device, wherein the fixing device is formed to be dispersed. 4. A fixing device for fixing a toner image on a transfer material to the transfer material by heating and pressurizing, wherein: a cylindrical heat conductive substrate having an electromagnetic induction heating body; And a magnetic elastic heating layer provided thereon to form a roll-shaped rotating member for electromagnetic induction fixing, and the magnetic elastic heating layer is formed by dispersing magnetic particles having a magnetization of 50 emu / g or more in the layer. A fixing device characterized by the above-mentioned. 5. A fixing device for fixing a toner image on a transfer material to the transfer material by applying heat and pressure, comprising: a cylindrical heat-conductive substrate having an electromagnetic induction heating body; And a magnetic elastic heat generating layer provided thereon to form a roll-shaped rotating member for electromagnetic induction fixing, and the magnetic elastic heat generating layer is formed by dispersing 10 to 50% by volume of magnetic particles in the layer. A fixing device. 6. The fixing device according to claim 1, wherein a coating layer is provided outside the magnetoelastic heating layer. 7. A fixing device for fixing a toner image on a transfer material to the transfer material by applying heat and pressure, comprising: a cylindrical heat-conductive substrate having an electromagnetic induction heating body; And a magnetic elastic heating layer provided thereon to form a roll-shaped rotating member for electromagnetic induction fixing, and induction heating while rotating the rotating member for electromagnetic induction fixing to control the temperature of the rotating member for electromagnetic induction fixing. A fixing device. 8. The fixing device according to claim 7, wherein the temperature control is performed during a warm-up time. 9. The fixing device according to claim 7, wherein the temperature control is performed when a print command is issued. 10. The fixing device according to claim 7, wherein, at the time of suspension, the set temperature of the electromagnetic induction fixing rotating member is reduced while the rotation of the electromagnetic induction fixing rotating member is stopped. apparatus. 11. A method of molding a rotating member for electromagnetic induction fixing having a magnetic elastic heating layer in which magnetic particles are mixed in a rubber material layer, wherein the rotation for electromagnetic induction fixing is performed at least for a certain period of time when the rubber material layer is crosslinked. A method of molding a rotating member for electromagnetic induction fixing, characterized in that the member is rotated about an axis of the member. 12. A fixing device for fixing a toner image on a transfer material to the transfer material by applying heat and pressure, comprising: a cylindrical heat-conductive substrate having an electromagnetic induction heating body; A magnetic elastic heating layer containing magnetic particles is provided to form a rotating member for electromagnetic induction fixing in a roll shape, and as it approaches the outer peripheral surface of the rotating member for electromagnetic induction fixing, A fixing device, wherein the density of the magnetic particles is increased.