CN101187797A - Fixing device and image forming device - Google Patents

Abstract

The invention provides a fixing device having at least: a first rotary body, having a heat generating layer from which heat is generated by action of a magnetic field: a second rotary body contacting the first rotary body; a magnetic field generating unit arranged to have a predetermined separation from the inner circumferential face of the first rotary body or to have a predetermined separation from the outer circumferential face of the first rotary body; and a heat generation controlling member arranged facing the magnetic field generating unit, with the first rotary body being between the heat generation controlling member and the magnetic field generating unit, the heat generation controlling member having at least a temperature-sensitive magnetic material having a Curie temperature and controlling generation of heat of the heat generating layer. The invention further provides an image forming device having at least the mixing device.

Description

Fixing device and image forming device

technical field

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

Background technique

A fixing device for an image forming device employing an electromagnetic induction heating mode is proposed.

As a fixing device of an image forming apparatus, a fixing device employing an electromagnetic induction heating mode has been proposed (for example, see Japanese Patent Application Publication No. (JP-A) No. 2001-176648). The electromagnetic induction heating mode is a mode in which a magnetic field generated by an induction coil is applied to a rotating body having a conductive layer, whereby the rotating body is directly heated by an eddy current generated in the conductive layer.

Contents of the invention

The present invention provides a fixing device capable of suppressing an excessive rise in temperature of a region other than a region through which paper passes (paper passing region) even if recording media of different sizes are used. The present invention also provides an image forming apparatus having a fixing device.

That is, a first embodiment of the first aspect of the present invention is a fixing device including:

a first rotating body having a heat generating layer that generates heat by the action of a magnetic field and formed in a substantially cylindrical shape;

a second rotating body in contact with the first rotating body;

a magnetic field generating unit for generating a magnetic field, the magnetic field generating unit being disposed with a predetermined interval from an inner peripheral surface of the first rotating body or with a predetermined interval from an outer peripheral surface of the first rotating body; and

a heat generation control member disposed to face the magnetic field generation unit, the first rotating body is located between the heat generation control member and the magnetic field generation unit, the heat generation control member includes a temperature sensing element having a Curie temperature magnetic material and controls the heat generation of the heat generating layer.

A second embodiment of the first aspect of the present invention is characterized in that the Curie temperature is substantially equal to or higher than the set temperature of the first rotating body, and the Curie temperature is substantially equal to or lower than the first rotating body. The heat-resistant temperature of a rotating body.

A third embodiment of the first aspect of the present invention is characterized in that the fixing device further includes a non-magnetic metal member, wherein the non-magnetic metal member includes a non-magnetic metal material, and the non-magnetic metal member is arranged on the Inside the first rotating body and facing the magnetic field generating unit, the first rotating body and the heat generation control member are located between the non-magnetic metal member and the magnetic field generating unit, so that the non-magnetic metal The member is not in contact with the heat generation control member.

A fourth embodiment of the first aspect of the present invention is characterized by further comprising a non-magnetic metal member, wherein the non-magnetic metal member includes a non-magnetic metal material, is arranged inside the first rotating body, and faces the The magnetic field generating unit, the first rotating body and the heat generation control member bring the non-magnetic metal member into contact with the heat generation control member and the heat generation control member contacts the first rotating body way, located between the non-magnetic metal member and the magnetic field generating unit.

A fifth embodiment of the first aspect of the present invention is characterized in that the heat generating layer includes a non-magnetic metal.

A sixth embodiment of the first aspect of the present invention is characterized by further including a shielding unit that shields eddy current generated in the heat generation control member due to electromagnetic induction from the magnetic field generating unit.

A seventh embodiment of the first aspect of the present invention is an embodiment of the sixth embodiment further characterized in that the shielding unit is a slit or a cutout, each of which is formed in the heat generation control member.

An eighth embodiment of the first aspect of the present invention is characterized in that the fixing device further includes a driving force transmission member for transmitting a rotational driving force to the first rotating body, the driving force transmission member is located at the At least one of the two ends of the first rotating body along the axial direction of the first rotating body.

A ninth embodiment of the first aspect of the present invention is characterized in that the heat generation control member is in contact with the first rotating body.

A tenth embodiment of the first aspect of the present invention is characterized in that the heat generation control member is arranged in contact with the first rotating body without applying pressure.

An eleventh embodiment of the first aspect of the present invention is characterized in that the heat generation control member is not in contact with the first rotating body.

A twelfth embodiment of the first aspect of the present invention is characterized in that the heat generation control member is a non-heat generating body.

A thirteenth embodiment of the first aspect of the present invention is characterized in that the temperature-sensitive magnetic material is a metal material.

A fourteenth embodiment of the first aspect of the present invention is characterized in that when the first rotating body contacts the second rotating body, the contact portion between the first rotating body and the second rotating body faces The inner peripheral surface of the first rotating body is elastically deformed.

Furthermore, a second aspect of the present invention is an image forming apparatus including:

latent image holder;

a latent image forming unit for forming a latent image on the surface of the latent image holder;

a developing unit that develops the latent image into an image using an electrophotographic developer;

a transfer unit for transferring the developed image to a transfer-receiving medium; and

The fixing device according to the first aspect of the present invention is used to fix the image on the transfer-receiving medium.

The first embodiment of the first aspect of the present invention provides the advantageous effect that the paper non-passing area in the first rotating body can be suppressed even if recording media of different sizes are used, compared to other structures lacking the features of this embodiment temperature rises excessively.

The second embodiment of the first aspect of the present invention provides the advantageous effects of suppressing poor fixing and deterioration of the first rotating body and suppressing the time when fixing an image, compared with other structures lacking the features of this embodiment. overheat.

The third embodiment of the first aspect of the present invention provides the advantageous effect of suppressing the heat generation control member in the region where the magnetic flux (magnetic field) penetrates, compared to other structures lacking the features of this embodiment. The temperature of the first rotating body increases.

The fourth embodiment of the first aspect of the present invention provides the advantageous effect of being able to increase the amount of heat energy transferred in the axial direction of the fixing belt per unit time, as compared with other structures lacking the features of this embodiment, to The axial direction radiates heat, thereby preventing excessive temperature rise in areas other than the paper passing area.

The fifth embodiment of the first aspect of the present invention provides the advantageous effect that, compared with other structures lacking the features of this embodiment, sufficient heat can be emitted even if the heat generating layer is thin, so that a heat generating layer with a small heat capacity can be obtained .

The sixth embodiment of the first aspect of the present invention provides the advantageous effect that suppression of self-heating of the heat generation control member can be achieved compared to other structures lacking the features of this embodiment.

The seventh embodiment of the first aspect of the present invention provides the advantageous effect that, compared with other structures lacking the features of this embodiment, suppression of self-heating of the heat generation control member and control of heat generation in the heat generation control member can be achieved. Inhibition of thermal energy transfer in the axial direction of the component.

The eighth embodiment of the first aspect of the present invention provides the advantageous effect of suppressing the rotation of the first rotating body due to the anti-skid effect of the first rotating body compared to other structures lacking the features of this embodiment Speed fluctuations, thereby suppressing paper wrinkling or unevenness during fusing.

The ninth embodiment of the first aspect of the present invention provides the beneficial effect that, compared with other structures lacking the features of this embodiment, the electromagnetic induction heating of the heat generating layer can be more sensitively controlled by the heat generation control member.

The tenth embodiment of the first aspect of the present invention provides the advantageous effect that the sliding resistance of the first rotating body is suppressed as compared with other structures lacking the features of this embodiment, so shortening of life due to wear is less likely to occur .

The eleventh embodiment of the first aspect of the present invention provides the advantageous effect that, compared with other configurations lacking the features of this embodiment, it is possible to suppress the starting of the fixing device due to the lack of a portion in direct contact with the first rotating body. The speed of temperature rise during driving is reduced, so that the fixing device can reach a fixable state more quickly.

The twelfth embodiment of the first aspect of the present invention provides the advantageous effect that self-heating of the heat generation control member is suppressed compared with other structures lacking the features of this embodiment, thereby enabling a response to the first rotating body. More sensitive control of temperature changes.

The thirteenth embodiment of the first aspect of the present invention provides the beneficial effect of making the thermal capacity of the heat generation control member smaller compared to other structures lacking the features of this embodiment, thus improving the response of the heat generation control member to the first The temperature tracking of the temperature change of the rotating body realizes more sensitive temperature response control.

The fourteenth embodiment of the first aspect of the present invention provides the advantage that paper can be removed from the first rotating body more easily than other configurations lacking the features of this embodiment.

The second aspect of the present invention provides the advantageous effect that a fixed image of high quality can be obtained over a long period of time compared with other structures lacking the feature of this aspect, unlike any case that does not satisfy the essential requirements of the present invention.

Description of drawings

FIG. 1 is a schematic configuration diagram showing an image forming apparatus according to an embodiment of the present invention.

FIG. 2 is a schematic sectional view showing the fixing device according to the embodiment of the present invention.

FIG. 3 is a schematic sectional view showing the fixing device according to the embodiment of the present invention.

4 is a schematic sectional view showing a state where the fixing belt and the pressing roller are separated from each other in the fixing device according to the embodiment of the present invention.

5A is a schematic cross-sectional view schematically showing a main magnetic flux penetrating the fixing belt in the fixing device according to the embodiment of the present invention.

5B is a schematic cross-sectional view schematically showing the main magnetic flux penetrating the fixing belt in the fixing device according to the embodiment of the present invention.

FIG. 6 is a schematic configuration diagram showing an image forming apparatus according to another embodiment of the present invention.

7 is a schematic sectional view showing a heat generation control member and a supporting member in a fixing device according to still another embodiment of the present invention.

8 is a schematic structural view showing a heat generation control member in a fixing device according to still another embodiment of the present invention, wherein the heat generation control member is provided with a slit.

9 is a schematic structural view showing a heat generation control member in a fixing device according to still another embodiment of the present invention, wherein the heat generation control member is provided with a slit.

Detailed ways

Hereinafter, exemplary embodiments according to the present invention will be described with reference to the accompanying drawings. In all the drawings, the same reference numerals are attached to members having substantially the same functions, and repeated descriptions of these members may be omitted.

FIG. 1 is a schematic configuration diagram showing an image forming apparatus according to an exemplary embodiment. FIG. 2 is a schematic cross-sectional view showing a fixing device according to an exemplary embodiment. FIG. 3 is another schematic cross-sectional view showing a fixing device according to an exemplary embodiment. FIG. 2 shows a cross-sectional view viewed along the axial direction of the fixing device, and FIG. 3 shows a cross-sectional view taken on line 2-2 in FIG. 2 and viewed along a direction perpendicular to the axial direction of the fixing device. Sectional view.

As shown in FIG. 1 , an image forming apparatus 100 as an image forming apparatus according to the present exemplary embodiment has a cylindrical photoreceptor drum 10 rotatable in one direction (direction of arrow A in FIG. 1 ). Around this photoreceptor drum 10, the following components are continuously arranged from the upstream side of the drum 10 to the downstream side of the drum 10 in the rotation direction of the drum 10: a charging device 12 for charging the surface of the photoreceptor drum 10; 14, for irradiating image-forming light L onto the photoreceptor drum 10 to form a latent image on the surface; a developing device 16, for selectively transferring toner to the surface of the photoreceptor drum 10 to form a toner agent image, the device is composed of developing units 16A to 16D; an endless belt-shaped intermediate transfer body 18 which is supported opposite to the photoreceptor drum 10 and has a rotatable peripheral surface; a cleaning device 20 for removing the toner remaining on the photoreceptor drum 10 after transferring the toner image; and a discharge exposure device 22 for discharging the surface of the photoreceptor drum 10 .

Further, disposed inside the intermediate transfer body 18 are: a transfer device 24 for primary transferring the toner image formed on the surface of the photoreceptor drum 10 to the intermediate transfer body 18; two support rollers 26A and 26B; and a transfer counter roller 28 for performing secondary transfer. By these members, the intermediate transfer body 18 is tensioned so as to be rotatable in one direction (direction of arrow B in FIG. 1 ). At a position opposed to the transfer counter roller 28 , a transfer roller 30 is arranged with the intermediate transfer body 18 between the rollers 28 and 30 . The transfer roller 30 is a roller for secondary transfer onto recording paper (recording medium) P of the toner image primarily transferred onto the outer peripheral surface of the intermediate transfer body 18 . The recording paper P is fed in the direction of arrow C into a portion where the transfer counter roller 28 and the transfer roller 30 are in contact with each other so as to be pressed against each other. At this press contact portion, the recording paper P on the surface of which the toner image is secondarily transferred is conveyed in the direction indicated by the arrow C as it is.

At a position downstream in the conveyance direction (arrow C direction) of the recording paper P, a fixing device 32 for heating the toner image on the surface of the recording paper P to melt and then The melted image is fixed on the recording paper P. As shown in FIG. The recording paper P is sent into the fixing device 32 through the paper conveying guide member 36 . On the downstream side of the intermediate transfer body 18 in the direction of rotation of the body 18 (arrow B direction), a cleaning device 34 for removing toner remaining on the surface of the intermediate transfer body 18 is arranged. .

A fixing device according to this exemplary embodiment will be described below.

As shown in FIGS. 2 and 3 , the fixing device 32 according to this exemplary embodiment has: a fixing belt 38 (first rotating body) in the form of an endless belt rotatable in one direction (direction of arrow D); a squeeze roller 40 (second rotating body), which is rotatable in one direction (direction of arrow E), and is in contact with the peripheral surface of the fixing belt 38 to press the surface; and a magnetic field generating device 42 (magnetic field generating unit), which is arranged to be The pressing contact surface of the belt 38 that contacts the pressing roller 40 is oppositely opposed to and separated from the outer peripheral surface of the fixing belt 38 .

On the inner peripheral side of the fixing belt 38 are provided: a fastening member 44 which forms a contact portion in combination with the pressing roller 40; a heat generation control member 46 which faces the magnetic field generating device 42 (the fixing belt 38 is located and the magnetic field generating device 42 ) and arranged in contact with the inner peripheral surface of the fixing belt 38 ; and a support member 48 that supports the fastening member 44 . The heat generation control member 46 is supported by a support member 48 . At both ends of the fixing belt 38 are arranged drive transmission members 50 for transmitting rotational power to rotationally drive the fixing belt 38 .

On the downstream side of the contact area between the fixing belt 38 and the pressing roller 40 in the transport direction of the recording paper P (direction of arrow F), a peeling member 52 is provided. This peeling member 52 includes: a support portion 52A, one end of which is supported in a fastened manner; and a peeling sheet 52B, which is supported by the portion 52A. The peeling member 52 is arranged such that the front end of the peeling sheet 52B approaches or contacts the fixing belt 38 .

First, the fixing belt 38 will be described below. Examples of the fixing belt to be used as the fixing belt 38 of the present exemplary embodiment include a belt having a substrate and a heat generating layer and a surface release layer formed on the outer peripheral surface of the substrate.

The substrate can be appropriately selected from substrates made of materials that have heat resistance and strength to support a thin heat-generating layer, and are penetrated by a magnetic field (magnetic flux) but do not easily generate heat or are not affected by the influence of the magnetic field. function to generate any heat. The following is an example of the substrate: having a thickness of equal to or about 30 μm to equal to or about 200 μm (desirably equal to or about 50 μm to equal to or about 150 μm, more desirably equal to or about 100 μm to equal to or about 150 μm) Metal strip (made of non-magnetic metal such as non-magnetic stainless steel, or soft magnetic material or hard magnetic material such as Fe, Ni, Cr or their alloys (such as Ni-Fe alloy or Ni-Cr-Fe alloy) made); or a resin tape (such as a polyimide tape) having a thickness of equal to or about 60 μm to equal to or about 200 μm.

The heat generating layer is made of a material that allows a magnetic field (magnetic flux) to easily penetrate therethrough and is easily heated by the action of the magnetic field. The heat capacity of the heat generating layer is preferably as small as possible.

In the case of using a general-purpose power supply with a frequency of 20kHz to 100kHz that can be produced cheaply, if the heat-generating layer is made thinner than 50μm, non-magnetic metals with lower intrinsic resistivity than magnetic metals are more prone to electromagnetic induction heating than magnetic metals. On the contrary, in the case where the thickness of the heat generating layer is 50 μm or more, the magnetic metal tends to generate heat more easily than the nonmagnetic metal.

Since magnetic metals generally have a high intrinsic resistivity and a specific magnetic permeability of several tens to several thousand, it is difficult for eddy currents to flow at the depth of the sheath of an electrical conductor made of magnetic metals. For example, iron (which is a magnetic metal) has a specific resistivity of 9.71×10 ^-8 Ωm, and nickel (which is a magnetic metal) has a specific resistivity of 6.84×10 ^-8 Ωm. In contrast, silver (which is a nonmagnetic metal) has an intrinsic resistivity of 1.59×10 ^-8 Ωm, copper (which is a nonmagnetic metal) has an intrinsic resistivity of 1.67×10 ^-8 Ωm, and aluminum (which is a nonmagnetic Metals) have an intrinsic resistivity of 2.7×10 ^-8 Ωm, and they all have a small intrinsic resistivity and a specific permeability of about 1. Therefore, when these non-magnetic metals are made thin, heat generation becomes easy. Especially when the non-magnetic metal is made to be 20 μm or thinner, heat generation becomes easy. On the contrary, when the nonmagnetic metal is made thicker than 20 μm, heat generation becomes difficult, and although eddy current flows, the amount of heat generation due to eddy current loss becomes small because intrinsic resistivity is small.

Specific examples of the structure of the heat generating layer include a heat generating layer having a nonmagnetic metal material with a thickness of about 2 μm to about 20 μm, and desirable examples thereof include a thickness of about 5 μm to about 15 μm and a total heat capacity of the heat generating region thereof is about 3 J/K or Smaller non-magnetic metallic materials. As described above, preferable examples of the non-magnetic metal material include copper, aluminum and silver.

Examples of the surface release layer include a fluorine-containing resin layer (such as a PFA layer which is a layer made of a copolymer formed of tetrafluoroethylene and perfluoroalkyl vinyl ether) having a thickness of about 1 μm to about 30 μm.

The structure of the fixing belt 38 is not limited to the above structure. Examples of the structure of the fixing belt 38 also include a belt in which a heat generating layer is located between two substrates, and specific examples thereof include a belt in which a heat generating layer such as a heat generating layer made of copper is located between two stainless steel layers. An elastic layer including silicone rubber, fluororubber, fluorosilicone rubber, or the like may also be disposed between the substrate and the heat generating layer or between the heat generating layer and the surface release layer.

The fixing belt 38 preferably has a small heat capacity (for example, a heat capacity of equal to or about 5 J/K to equal to or about 60 J/K, desirably equal to or about 30 J/K, for example, by making its thickness small or selecting its constituent materials. K or less heat capacity) structure.

The diameter of the fixing belt 38 can be selected arbitrarily, and generally ranges from equal to or about 20 mm to equal to or about 50 mm. It is also possible, for example, by applying a fluorine-containing resin to the fixing belt 38 by providing a film that is covered with a fluorine-containing resin and has anti-slip durability, such as a film that has anti-slip durability and is provided only on the fastening member 44 . The inner peripheral surface of the fixing belt 38 is modified, or by applying a lubricant such as silicone oil to the inner peripheral surface of the fixing belt 38 .

Next, the squeeze roller 40 will be described. Although the present exemplary embodiment is a case where the fixing belt and the pressing roller are separated from each other, the scope of the present invention also includes a case where the fixing belt and the pressing roller are in constant contact with each other. By means of spring members (not shown in the drawings) that press the pressing roller 40 at both ends of the pressing roller 40 across the fixing belt 38, the The squeeze roller 40 is placed on the fastening member 44 . When the squeeze roller 40 is preheated (preheated), the squeeze roller 40 moves so as to be separated from the fixing belt 38 (see FIG. 4 ).

The squeeze roller 40 may be, for example, a roller having a cylindrical core member 40A made of metal and an elastic layer 40B (such as a silicon rubber layer or a fluorine rubber layer) formed on the surface of the core member 40A. The squeeze roll 40 also has a surface release layer (such as a fluorine-containing resin layer) on the outermost surface thereof, if necessary.

The heat generation control member 46 will now be described. The heat generation control member 46 is formed in a shape similar to that of the inner peripheral surface of the fixing belt 38 . The heat generation control member 46 is thus in contact with the inner peripheral surface of the fixing belt 38 and arranged to face the magnetic field generating device 42 across the fixing belt 38 .

The heat generation control member 46 is arranged in contact with the inner peripheral surface of the fixing belt 38 without applying substantial pressure while keeping the cylindrical shape of the fixing belt 38 out of contact with the support member 48A by the spring member 48B of the support member 48 . In the present exemplary embodiment, the heat generation control member 46 is in contact with the inner peripheral surface of the fixing belt 38 with a force of about 1N. Since no tension is applied to the belt, the shape of the belt does not change by an extreme amount even when the heat generation control member comes into contact therewith. If a large tension is applied to the fixing belt, the sliding resistance becomes higher, and as a result, the life of the belt is shortened due to wear. When the sliding resistance increases, the driving torque of the belt also increases, which causes repeated application of torque to the belt, which causes problems such as cracking or bending of the heat-generating layer of the belt.

The heat generation control member 46 is a temperature control member, and is composed of a temperature-sensitive magnetic material having a Curie temperature, such as a temperature-sensitive magnetic alloy. The Curie temperature of the heat generation control member 46 is preferably equal to or higher than the set temperature of the fixing belt 38 , and is preferably equal to or lower than the heat-resistant temperature of the fixing belt 38 . Specifically, the Curie temperature is desirably from about 140°C to about 240°C, and more desirably from about 150°C to about 230°C.

The heat generation control member 46 is preferably a "non-heat generating body" that does not generate heat due to the action of a magnetic field. If the heat generation control member 46 has a sufficient heat generation capability, when the heat generation layer heats the fixing belt, the heat generation control member 46 can generate heat by electromagnetic induction, and as a result, the heat generation control member 46 will be damaged due to eddy current loss and hysteresis loss. And fever. If this heat generation amount is large, the temperature of the heat generation control member 46 rises and unintentionally reaches its Curie temperature, thereby exhibiting its temperature control capability when not necessary. Since the heat generation control member 46 is a necessary member for controlling the temperature of the fixing belt, it should be necessary to make this undesired rise in temperature due to self-heating as small as possible. The "non-heat generating body" of the present exemplary embodiment is a member having a sufficiently small self-heating capability compared with that of the heat generating layer. When there is a problem showing the function of the heat generation control member 46 due to its self-heating ability, the heat generation control member 46 may be configured with slits or cutouts so that eddy current loss is less likely to occur. The slit or cutout functions as a shielding unit that shields eddy current generated in the heat generation control member 46 due to the electromagnetic induction action of the magnetic field generating device 42 .

For example, as shown in FIGS. 8 and 9 , slits may be provided on the surface of the heat generation control member, thereby shielding the path of the eddy current. The slit 46A may be formed by providing one or more grooves along the width direction of the heat generation control member 46 (ie, along the circumferential direction of the fixing belt 38 ). The slit 46A may be formed as a plurality of grooves arranged with a certain interval therebetween. Alternatively, the one or more grooves of the slit 46A may be provided in a direction inclined with respect to the width direction of the heat generation control member 46 . By forming the slit 46A, heat transfer (heat conduction) in the axial direction of the heat generation control member 46 (rotation axis direction of the fixing belt 38 ) can be controlled. As a result, when the temperature of the region other than the paper passing region in the fixing belt 38 starts to rise due to continuous passage of small-sized paper, heat is transferred from the temperature-rising region in the region other than the paper passing region to the facing heat generation control member 46 . Since the saturation magnetic flux density of the heat generation control member 46 decreases as the temperature rises, the heat generation of the heat generation layer in the area other than the paper passing area of the fixing belt starts to be controlled. Furthermore, when the temperature rises near the Curie temperature of the temperature-sensitive magnetic material included in the heat generation control member 46, the heat generation of the heat generation layer is further controlled because the heat generation control member changes from magnetic to nonmagnetic. At this time, when the heat of the high-temperature portion of the heat generation control member 46 in the area other than the paper-passing area is transferred to the low-temperature portion in the axial direction, because the temperature of those areas other than the paper-passing area is lowered and the control of the heat generation of the heat-generating layer can be stopped , as a result, the effect of controlling temperature rise in areas other than the sheet passing area of the fixing belt decreases. It is preferable to provide the above-mentioned slits from the viewpoint of preventing heat transfer along the axial direction.

8 is a schematic structural (plan) view showing a heat generation control member in a fixing device according to another embodiment of the present invention, wherein the heat generation control member is provided with a slit. 9 is a schematic structural (side view) view showing a heat generation control member in a fixing device according to still another embodiment of the present invention, wherein the heat generation control member is provided with a slit.

Temperature-sensitive magnetic materials can be roughly classified into metallic materials or oxide materials. Oxide materials such as ferrite can have the following problems: difficult to make thin (about 300 μm or less) and easy to crack, which makes handling difficult; low thermal conductivity due to large heat capacity, which prevents oxide The material sensitively follows the temperature change of the fixing belt, resulting in failure to achieve the goal of controlling the heat generation of the heat generation control member 46 .

In view of solving the above problems, the heat generation control member uses, as the temperature-sensitive magnetic metal material, a metal material that is cheap, can be easily formed into a thin form, and has good workability, flexibility, and high thermal conductivity. Preferable examples of the metal material include metal alloy materials including at least one of Fe, Ni, Si, B, Nb, Cu, Zr, Co, Cr, Mo, V, Mn, etc., and specific examples thereof include Fe and Binary adjustment magnets made of Ni and ternary adjustment magnets made of Fe, Ni and Cr.

A temperature-sensitive magnetic material is a ferromagnetic material, and when its temperature rises close to the Curie temperature of the material, the material is demagnetized (paramagnetized). When a ferromagnetic material with a specific permeability of several hundred or more is demagnetized (i.e., enters a paramagnetic or diamagnetic state), the specific permeability approaches 1, so that the magnetic flux density changes (i.e., the magnetic field becomes stronger or weak). Therefore, by demagnetization of the temperature-sensitive magnetic material, its magnetic flux density becomes weak, so that the material can become a material that hardly generates heat.

The sheath depth of any electrical conductor made of metal is generally expressed by equation (1) below. When the sheath depth of the conductor is set to the thickness of the temperature-sensitive magnetic metal layer or less, the conductor is heat-treated so that its magnetic permeability becomes high, or the frequency of the magnetic field generating device 42 becomes high. Alternatively, this setting can be achieved by selecting a material with a small intrinsic resistivity value. In this exemplary embodiment, it is not necessary that the sheath depth of the conductor is substantially equal to or less than the thickness of the temperature-sensitive magnetic metal layer. However, it is desirable to set the sheath depth of the conductor to the thickness of the temperature-sensitive magnetic metal layer or less because the beneficial effect increases. In this case, the specific magnetic permeability of the temperature-sensitive magnetic material is selected according to Equation (1) considering the thickness of the heat generation control member 46 when the heat generation control member 46 is subjected to a temperature substantially lower than the Curie temperature. For example, when the temperature sensitive magnetic material is a magnetic alloy of Fe—Ni and the heat generation control member 46 has a thickness of about 50 μm, the specific magnetic permeability of the temperature sensitive magnetic material is selected to be at least about 5000.

Equation 1

$\mathrm{<span\; class="notranslate">\; \&delta;</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 503</span>}\sqrt{\frac{\mathrm{<span\; class="notranslate">\; \&rho;</span>}}{\mathrm{<span\; class="notranslate">\; f</span>}<span\; class="notranslate">\; \&Center\; Dot;</span>{\mathrm{<span\; class="notranslate">\; \&mu;</span>}}_{\mathrm{<span\; class="notranslate">\; r</span>}}}}$

In Equation (1), δ denotes "skin depth", which is the depth (m) of the outer skin of the conductor, p denotes the intrinsic resistivity value (Ωm), f denotes the frequency (Hz), and μ denotes the specific magnetic permeability.

Examples of the shape of the heat generation control member 46 include having a thickness (for example, equal to or about 20 μm to equal to or about 300 μm) and corresponding to a predetermined center angle range of the cylinder (for example, substantially equal to or about 30 degrees to equal to or approximately within a range of 180 degrees), but the range of the shape of the heat generation control member 46 is not limited thereto.

The fastening member 44 will be described below. The fastening member 44 is, for example, a rod-shaped member having an axis in the axial direction (width direction) of the fixing belt 38 . The fastening member 44 is a member for resisting the action of pressure from the squeeze roller 40 . When the pressing roller 40 presses the fastening member 44 across the fixing belt 38 , the fixing belt 38 deforms toward its inner peripheral surface side. When the fixing belt 38 at the downstream side of the contact area of the pressing roller 40 with the fastening member 44 in the above-mentioned paper conveying direction is given a curvature, the paper is peeled from the fixing belt.

In order to obtain paper peelability, the fixing belt is selected in consideration of "whether the fixing belt 38 is deformed toward its inner peripheral surface side when the pressing roller 40 presses the fastening member 44 across the fixing belt 38 ." However, in the fixing belt 38 in the present exemplary embodiment, a metal material is used, and therefore, flexibility depends on the metal layer for determining the rigidity of the fixing belt 38 (ie, the thickness of the temperature-sensitive magnetic metal layer).

Whether or not the fixing belt 38 warps or bends toward its inside in its elastic deformation region can be checked by using a hard material such as non-magnetic stainless steel. The amount of warpage thereof was evaluated when a pressure equal to or greater than at least a load applied to the fixing belt at the time of image fixing was given to the fixing belt. As a result, when the thickness of the hard material was about 250 μm, the material hardly warped. When the thickness is about 200 μm, slight warpage starts to occur. When the thickness is about 150 μm, about 125 μm, about 100 μm, and about 75 μm, sufficient warpage is generated. Therefore, the metal material layer of the fixing belt 38 is desirably equal to or about 200 μm or less.

Particularly preferable examples of the material of the fastening member 44 include heat-resistant resin and heat-resistant rubber. Examples of the material of the fastening member 44 include heat-resistant resins such as glass fiber-reinforced PPS (polyphenylene sulfide), phenol, polyimide, or liquid crystal polymer. In addition to these materials, as a metal having high thermal conductivity, preferable examples thereof include aluminum.

Next, the supporting member 48 will be described. A structural example of the support member 48 includes a support member 48A, a spring member 48B for supporting the heat generation control member 46 , and shafts 48C at both ends in the longer direction of the support member 48A.

The material forming the support member 48A and the shaft 48C is not particularly limited as long as the material is a material that gives warpage within the allowable level range or less when the material is subjected to pressure from the squeeze roller 40 . amount of curvature (specifically, for example, an amount of curvature equal to or about 0.5 mm or less), and examples thereof include metal materials and resin materials. In addition, the support member 48A is formed of a non-magnetic metal material (ie, a non-magnetic metal member such as copper, aluminum, silver, or non-magnetic stainless steel).

In the case where the shaft is greatly warped due to the load imposed on the shaft causing problems related to the rigidity of the shaft, the supporting member may be a structure having a member made of a Young's modulus that gives a small deviation. materials and non-magnetic materials. In this case, the thickness of the nonmagnetic layer can be made approximately equal to or greater than the skin depth expressed by equation (1).

In the case where the supporting member 48A is formed of a magnetic metallic material, the side of the supporting member 48A facing the magnetic field generating device 42 may be shielded so that the magnetic flux from the magnetic field generating device 42 does not reach the magnetic metallic material, The member is formed of a non-magnetic metallic material such as copper, aluminum, or silver that has a low resistivity and is approximately equal to or greater than the depth of the sheath. If the magnetic flux from the magnetic field generating device 42 reaches the magnetic metal material, energy is wasted ineffectively because Joule heating caused by eddy current increases.

On the other hand, the spring member 48B is a connecting member for connecting the heat generation control member 46 and the support member 48A, and directly supports the heat generation control member 46 . The spring member 48B connects the heat generation control member 46 at both ends in the width direction of the heat generation control member 46 .

In addition, the spring member 48B may be formed of, for example, a curved leaf spring such as a leaf spring made of metal or a leaf spring made of one or more of various elastic bodies. The heat generation control member 46 is supported by the spring member 48B, and even when the fixing belt 38 is centrifugally rotated so that the fixing belt 38 is radially displaced, the heat generation control member 46 follows the displacement to maintain a contact state with the inner peripheral surface of the fixing belt 38 .

The heat generation control member 46 may also function as a spring member 48B. In this case, it is possible to form a structure in which the heat generation control member and the spring member are integrated with each other.

The driving force transmission member 50 will be described below. The driving force transmission members 50 are each a member for transmitting a driving force for rotating the fixing belt 38 around its rotation center. The members 50 each include, for example, a flange portion 50A attached to the inside of one end of the fixing belt 38 , and a cylindrical gear portion 50B having unevenness on its outer peripheral surface. The driving force transmission member 50 is made of, for example, a metal material or a resin material.

By inserting the flange portion 50A inside the end portion of the fixing belt 38 , the driving force transmission member 50 is supported by the end portion of the fixing belt 38 . The gear portion 50B of the driving force transmission member 50 is driven to rotate by a motor or the like not shown in the drawings. In addition, a rotational driving force is transmitted to the fixing belt 38, thereby causing the belt 38 to rotate about its rotation center.

Although the driving force transmission members 50 are provided at both ends of the fixing belt 38 in the axial direction thereof in the present exemplary embodiment, the present invention is not limited thereto. The driving force transmission member 50 may be provided only at one end of the fixing belt 38 in the axial direction thereof. Although the driving force transmission member 50 is supported at the end of the fixing belt 38 by mounting the flange portion 50A inside the end of the fixing belt 38 in the present exemplary embodiment, the present invention is not limited thereto. The driving force transmission member 50 can be supported at the end of the fixing belt 38 by disposing the end of the fixing belt 38 inside the flange portion 50A.

The magnetic field generating means 42 will be described below. The magnetic field generating device 42 is formed to have a shape following the outer peripheral surface of the fixing belt 38 . This device 42 is arranged to be opposed to the heat generation control member 46 (between which the fixing belt 38 is inserted), and is separated from the outer peripheral surface of the fixing belt 38 to have, for example, equal to or about 1 mm to equal to or about 3 mm. interval. In the magnetic field generating device 42 , an exciting coil (magnetic field generating unit) 42A wound in multiple turns is arranged along the axial direction of the fixing belt 38 .

An excitation circuit (not shown in the drawing) for supplying an alternating current to the excitation coil 42A is connected to the excitation coil 42A. Further, the magnetic-substance member 42B is arranged to extend on the surface of the exciting coil 42A along the length direction of the exciting coil 42A (the axial direction of the fixing belt 38 ). By disposing the excitation coil 42A and the fixing belt 38 between the magnetic substance member 42B and the heat generation control member 46 which is a magnetic substance, a magnetic circuit is formed, and control of magnetic field leakage, improvement of magnetic coupling, and power factor can be achieved improvement of. Preferably, the magnetic substance member 42B is a ferromagnetic substance. Examples of ferromagnetic substances include ferromagnetic metal materials such as iron, nickel, chromium, and manganese, their alloys, their oxides, and the like. Ferromagnetic materials can be selected so that eddy current losses and hysteresis losses are minimized. In the case where the eddy current loss is large, slits or slits may be formed in the heat generation control member 46, or the heat generation control member 46 may be configured to be laminated in a thin plate shape such as a silicon steel plate to make it harder for eddy current to flow.

Examples of materials with small eddy current loss and small hysteresis loss include soft ferrite, soft magnetic metal materials as oxides, and the like.

The output of the magnetic field generating device 42 is applied in a range in which, for example, a magnetic flux (magnetic field) penetrates the heat generating layer of the fixing belt 38 to generate heat, and at a temperature lower than the Curie temperature, the magnetic flux (magnetic field) It is not easy to penetrate the heat generation control member 46 so as not to generate heat.

The magnetic field generating device 42 is provided on the inner peripheral surface side of the fixing belt 38 at a predetermined interval from the surface. In this case, the heat generation control member 46 is disposed in contact with the outer peripheral surface of the fixing belt 38 .

The operation of the image forming apparatus 100 according to the present exemplary embodiment will be described below.

First, the surface of the photoreceptor drum 10 is charged by the charging device 12 . Next, from the exposure device 14 , light L is imagewise irradiated onto the surface of the photoreceptor drum 10 , whereby a latent image is formed on the surface by the difference between the electrostatic potentials on the surface. The photoreceptor drum 10 rotates in the direction of arrow A, so that the latent image is moved to a position opposing one of the developing units (unit 16A) of the developing device 16 . The first color toner is then transferred from the developing unit 16A onto the latent image, thereby forming a toner image on the surface of the photoreceptor drum 10 . By rotating the photoreceptor drum 10 in the direction of arrow A, the toner image is conveyed to a position opposite to the intermediate transfer body 18, and then the image is electrostatically primarily transferred to the intermediate transfer body by the transfer device 24. 18 on the surface.

After the primary transfer, the toner remaining on the surface of the photoreceptor drum 10 is removed by the cleaning device 20 . The cleaned surface of the photoreceptor drum 10 is potential-initialized by the discharge exposure device 22 and moved to a position facing the discharge device 12 again.

Thereafter, three of the developing units (units 16B, 16C, and 16D) of the developing device 16 are successively moved to positions facing the photoreceptor drum 10 . The second, third, and fourth color toner images are successively formed in the same manner so that the four color toner images are superimposed (merged). These superimposed (combined) toner images are transferred onto the surface of the intermediate transfer body 18 at one time.

The toner image merged on the intermediate transfer body 18 is conveyed to a position where the transfer roller 30 and the transfer counter roller 28 face each other by the rotational movement of the intermediate transfer body 18 in the direction of arrow B, so that The toner image is in contact with the recording paper P that is fed. A transfer bias voltage is applied to these members 30 and 18 across the transfer roller 30 and the intermediate transfer body 18 , whereby the toner images are secondarily transferred onto the surface of the recording paper P. As shown in FIG.

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

The action of the fixing device 32 according to the present exemplary embodiment will be described below.

For example, when the toner image forming action is started in the image forming apparatus 100 (hereinafter it should be naturally understood that the expression "simultaneously" cannot be regarded as necessarily requiring two actions to be executed strictly simultaneously: two actions are of course allowed There is a certain time lag between actions), first, the following actions are performed in the fixing device 32: In the state where the fixing belt 38 and the pressing roller 40 are separated from each other (see FIG. 4 ), the driving force transmission member 50 is driven by a motor (not shown). out) to rotate, and thereby the fixing belt 38 is driven to rotate in the direction of arrow D at a peripheral speed of, for example, equal to or about 200 mm/sec.

Along with the rotational drive of the fixing belt 38 , an alternating current is supplied from an excitation circuit (not shown) to the excitation coil 42A included in the magnetic field generating device 42 . When an alternating current is supplied to the exciting coil 42A, a magnetic flux is generated or destroyed around the exciting coil 42A. This generation and destruction is repeated. When a magnetic flux (magnetic field) intersects the heat generating layer 38A of the fixing belt 38 , an eddy current is generated in the heat generating layer, thereby generating a magnetic field that suppresses a change in the previous magnetic field. As a result, heat is generated in proportion to the skin resistance of the heat generating layer 38A and the square of the current flowing into the heat generating layer 38A (see FIG. 5A ). In FIG. 5A and FIG. 5B , the dashed-two dotted lines both represent main magnetic fluxes.

By this heat generated in the heat generating layer 38A, the fixing belt 38 is heated to a set temperature (for example, 150° C.) in about 10 seconds, for example.

Next, the recording paper P sent to the fixing device is sent to the contact area between the fixing belt 38 and the pressing roller 40 in a state where the pressing roller 40 presses the fixing belt 38, and then is heated by the heater. The fixing belt 38 and the pressing roller 40 are heated and pressed to fuse the toner image and press the image on the surface of the recording paper P. As shown in FIG. As a result, the toner image is fixed on the surface of the recording paper P. As shown in FIG.

When an image is continuously fixed in image fixing by the fixing belt 38 and the squeeze roller 40 on the recording paper P whose size is smaller than the fixing area width (ie, axial length) of the fixing belt 38 , in the fixing belt 38 Heat is consumed in the paper passing area, but not in areas other than the paper passing area. Therefore, the temperature rises in the area other than the paper passing area in the fixing belt 38 .

When the temperature of the area other than the paper passing area in the fixing belt 38 approaches the Curie temperature of the temperature-sensitive magnetic material constituting the heat generation control member 46 , the heat generation control member 46 overlaps (contacts) the area other than the paper passing area in the fixing belt 38 . ) are demagnetized. In this way, a difference in magnetic flux (that is, the strength of the magnetic field) is generated between the magnetic paper passing region and the region other than the demagnetized (that is, in a paramagnetic state) paper passing region. As a result, in the heat generating layer, the heat generated in the area other than the paper passing area is smaller than the heat generated in the paper passing area. In this way, heat generation in the heat generating layer of the fixing belt 38 is controlled by the heat generation control member 46 .

As can be understood from Equation (1), when the heat generation control member 46 is demagnetized (ie, its specific magnetic permeability is close to 1), magnetic flux (magnetic field) easily penetrates it. As shown in FIG. 5B , a case is given at this time of the supporting member 48A (which is made of a non-magnetic metallic material having a low intrinsic resistivity value such as silver, copper, or aluminum) (that is, its thickness is greater than the skin depth). Next, magnetic flux (magnetic field) mainly flows into the support member 48A as an eddy current, thereby suppressing further heat generation due to loss based on the eddy current flowing in the heat generating layer of the fixing belt 38 . The magnetic flux (magnetic field) penetrating the heat generation control member 46 reaches the supporting member 48A made of a non-magnetic metal material, thereby returning to the magnetic field generating device 42 . In addition, the support member 48 is arranged so as not to be in contact with the fixing belt 38 nor the heat generation control member 46 so that the support member 48A does not take heat energy away from the fixing belt 48 .

The support member 48A may be composed of: a non-magnetic metal sensing member 48D comprising a metal with low intrinsic resistivity, such as aluminum, copper, or silver; and the structure of the support 48F. Examples of such a configuration include the example shown in FIG. 7 in which a curved plate-shaped non-magnetic metal induction member 48D is provided between the heat generation control member 46 and the supporting member 48A. Here, as described above, the nonmagnetic metal induction member 48D having low intrinsic resistivity is a member for controlling heat generation due to eddy current loss flowing in the heat generating layer of the fixing belt 38 . The support 48F is a member for supporting the load from the squeeze roller 40, and preferably has rigidity with little flexibility. Furthermore, when the nonmagnetic metal induction member 48D is in contact with the fixing belt 38 and also in contact with the heat generation control member 46 , the main object of heat transfer between the fixing belt 38 and the nonmagnetic metal induction member 48D is heat conduction via the heat generation control member 46 , and the amount of heat transfer per unit time becomes larger. As a result, since the amount of heat transfer per unit time in the axial direction becomes large, an effect of controlling the temperature rise is obtained by dispersing the temperature rise in the region other than the sheet passing region of the fixing belt 38 itself in the axial direction. Here, FIG. 7 is a schematic sectional view showing a heat generation control member and a supporting member in a fixing device according to still another embodiment of the present invention.

On the other hand, when the fixing belt 38 and the pressing roller 40 perform fixing, the fixing belt 38 is supported by and in pressure-free contact with the heat generation control member 46 having a shape similar to the shape of the inner peripheral surface of the fixing belt 38 rotation, and any residual vibration from the fastening member of the fixing belt is suppressed while suppressing the sliding resistance, and is subjected to an electromagnetic force (between the magnetic field from the coil and the reaction magnetic field acting in the opposite direction of the magnetic field of the eddy current flowing in the heat generating layer The repulsive force, that is, the force in the direction away from the coil is applied to the strip). Thereby, while maintaining a stable distance between the fixing belt and the coil, fixing is performed while maintaining the shape of the belt.

When the recording paper P is sent out from the contact area between the fixing belt 38 and the squeeze roller 40 , the paper P may advance straight in the direction in which the paper P is sent out due to its rigidity. Then, the front end of the paper P is peeled off from the fixing belt 38 deformed toward the inner peripheral surface side of the fixing belt 38 to be curled. The peeling member 52 (peeling sheet 52B) is then put into the gap between the leading end of the recording paper P and the fixing belt 38 , thereby peeling the recording paper P from the surface of the fixing belt 38 .

As described above, the toner image is formed on the recording paper P and then fixed on the recording paper P. As shown in FIG.

In the present exemplary embodiment, the fixing belt 38 is shown which rotates and is in contact with and performed by the heat generation control member 46 having a shape similar to the shape of the inner peripheral surface of the fixing belt 38 without pressure. support. However, the scope of the structure of the present invention is not limited thereto. Examples of the present invention also include an embodiment in which the fixing belt 38 and the heat generation control member are arranged not to contact each other, as shown in FIG. 6 . This embodiment has a structure that prevents thermal energy of the fixing belt 38 from being transferred to the heat generation control member 46 .

Example

Experimental examples of the above-described exemplary embodiment of the fixing device according to the present invention will be described below.

Test example 1

First, the following evaluations were performed using the fixing device (see FIG. 1 , FIG. 2 and FIG. 6 ) according to the above-described embodiment. The components used in this device are as follows.

Fixed tape: by sequentially laminating a copper layer (heat generating layer) with a thickness of 10 μm and a PFA layer (PFA : a copolymer of tetrafluoroethylene and perfluoroalkyl vinyl ether) and has a heat-resistant temperature of about 240°C.

A squeeze roller: having an outer diameter of 28mm and a length of 355mm, and by sequentially laminating a sponge elastic layer with a thickness of 5mm and a thickness of 30μm on a core metal shaft with a diameter of 18mm and made of stainless steel as a surface anti-adhesion The rollers formed by the PFA layer of the layer.

A heat generation control member: the heat generation control member is a curved plate having a shape obtained by cutting out a portion corresponding to a central angle of 160 degrees of a cylinder having a thickness of 150 μm, a length of 340 mm, and a diameter of 30 mm, the curved plate being made of Fe having a maximum specific magnetic permeability of 10000 or more (a work-hard material with a specific magnetic permeability of approximately 400 is heat-treated by annealing to provide a soft material with high magnetic permeability) and a Curie temperature in the range of 215°C to 230°C -Consisting of a Ni alloy (trade name: MS-220, manufactured by NEOMAX Materials).

Certain distance between fixing belt and heat generation control member: Although the fixing belt and heat generation control member are in contact with each other in the structure of FIG. 2 , the heat generation control member is arranged not to be in contact with the fixing belt in the structure of FIG. 6 . In the structure of FIG. 6, the heat generation control member is arranged such that the distance between the fixing belt and the heat generation control member is about 1 mm. An arc corresponding to an angle of 160° of a circle having a radius of 14 mm was made not to be in contact with the fixing belt so as to be substantially concentric therewith. In the case of the structure in Fig. 6, since the initialization preparation can be completed in an extremely short time (in this test example, the warm-up time (start-up time) is 6 to 8 seconds), it is possible to turn on the power only when in use , and can provide an extremely energy-efficient fixing unit. On the other hand, in the structure of Fig. 2, the warm-up time takes 11 to 13 seconds.

- Support member: a support member made of aluminum, which is a non-magnetic metal.

evaluate

In each structure shown in Fig. 2 and Fig. 6, the power of the magnetic field generating device is controlled within the range of 400 to 1100W. Under the condition that the set temperature is 160°C to 170°C and the processing speed is 170 mm/s, using recording paper (trade name: JD PAPER, manufactured by Fuji Xerox Co., Ltd., and all of which are B5 in size, the weight per unit area is 98g/m ² ). Feed the paper into the unit with one of the short edges facing forward. Continuous image fixing on 1000 sheets. Then the temperature of the paper passing area in the fixing belt and the temperature of the area other than the paper passing area were measured respectively.

As a result, the temperature of the paper passing area in the fixing belt is 160°C to 170°C, while the temperature of the area other than the paper passing area is controlled to 230°C or less.

Comparative example 1

Comparative Example 1 was prepared in the same manner as Experimental Example 1 except that no heat generation control member was provided. Then, the same evaluation as that of Test Example 1 was performed on Comparative Example 1.

As a result, before image fixing was performed continuously for 100 sheets on the same paper as described above, the temperature of the area other than the paper passing area exceeded 235° C., which is the heat-resistant temperature of the fixing belt.

Next, a heat pipe having a diameter of 12.7 mm was provided as a temperature equalizing unit for suppressing a temperature rise in a region other than the paper passing region, and brought into contact with the squeeze roller. The same evaluation as above was performed on the thus modified fixing device of Comparative Example 1. As a result, when image fixing was performed continuously on about 300 to 400 sheets of the same paper, the temperature of the area other than the paper passing area reached 235°C, which is the heat-resistant temperature of the fixing belt.

From the above results, it is understood that compared with the comparative examples, even if recording media having various sizes such as small-sized recording media are used in the test examples of the present invention, the area other than the paper passing area in the fixing belt can be reduced. The temperature rise is lower, thus preventing overheating.

Claims (15)

1. fixing device, this fixing device comprises:

First rotary body, it has the heating layer that generates heat by the effect in magnetic field and forms the general cylindrical shape shape;

Second rotary body, it contacts with described first rotary body;

The magnetic field generation unit is used to produce magnetic field, and described magnetic field generation unit is set to inner peripheral surface with described first rotary body to have predetermined space or have predetermined space with the outer peripheral face of described first rotary body; And

The heating control member, it is set in the face of described magnetic field generation unit, described first rotation position is between described heating control member and described magnetic field generation unit, and described heating control member comprises temperature-sensitive magnetic material with Curie temperature and the heating of controlling described heating layer.

2. fixing device as claimed in claim 1, wherein, described Curie temperature is equal to or higher than the design temperature of described first rotary body substantially, and described Curie temperature is equal to or less than the heat resisting temperature of described first rotary body substantially.

3. fixing device as claimed in claim 1, this fixing device also comprises the nonmagnetic metal member, wherein said nonmagnetic metal member comprises nonmagnetic material, described nonmagnetic metal member is disposed in the described first rotary body inboard, and in the face of described magnetic field generation unit, described first rotary body and described heating control member between described nonmagnetic metal member and described magnetic field generation unit, thereby described nonmagnetic metal member is not contacted with described heating control member.

4. fixing device as claimed in claim 1, this fixing device also comprises the nonmagnetic metal member, wherein said nonmagnetic metal member comprises nonmagnetic material, is disposed in the inside of described first rotary body, also faces described magnetic field generation unit, described first rotary body and described heating control member so that described nonmagnetic metal member contact with described heating control member and make described heating control member and the contacted mode of described first rotary body, between described nonmagnetic metal member and described magnetic field generation unit.

5. fixing device as claimed in claim 1, wherein, described heating layer comprises nonmagnetic metal.

6. fixing device as claimed in claim 1, wherein, this fixing device also comprises screen unit, this screen unit to since the vortex flow that in described heating control member, produces from the electromagnetic induction of described magnetic field generation unit shield.

7. fixing device as claimed in claim 6, wherein, slit or otch are as described screen unit, and it all is formed in the described heating control member.

8. fixing device as claimed in claim 1, this fixing device also comprises the driving force conveying member that is used for rotary driving force is transferred to described first rotary body, and described driving force conveying member is arranged at least one end along the axial two ends of described first rotary body of described first rotary body.

9. fixing device as claimed in claim 1, wherein, described heating control member contacts with described first rotary body.

10. fixing device as claimed in claim 1, wherein, described heating control member is arranged to described first rotary body and contacts under the situation of not exerting pressure.

11. fixing device as claimed in claim 1, wherein, described heating control member does not contact with described first rotary body.

12. fixing device as claimed in claim 1, wherein, described heating control member is non-heater.

13. fixing device as claimed in claim 1, wherein, described temperature-sensitive magnetic material is a metal material.

14. fixing device as claimed in claim 1, wherein, when described first rotary body contacted with described second rotary body, the contact portion of described first rotary body and described second rotary body was towards the inner peripheral surface elastic deformation of described first rotary body.

15. an image processing system, this image processing system comprises:

Sub-image keeps body;

Sub-image forms the unit, is used for forming sub-image on the surface of described sub-image maintenance body;

Developing cell, it utilizes electrophotographic developing that described image development is become image;

Transfer printing unit is used for the image through developing is transferred to the transfer printing receiver media; And

As each described fixing device in the claim 1 to 14, be used for described image fixing at described transfer printing receiver media.

Images