JP2002006658A - Image heating device and image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problem that it is necessary to narrow clearance between an exciting means and the fixing surface which is opposite to it, as a result the fixing face is probably scratched when the exciting means is deformed or moved, in the case of an image heating device which heats a rotary induction heating element by an external exciting means. SOLUTION: An endless heating member and an exciting means which is disposed along the peripheral surface of the heating member and induction-heats the heating member, and a holding member which holds the exciting member and is made of an insulating, nonmagnetic material, are included. The holding member has partly has a space in an axial direction, so that the fixing surface is prevented from being scratched when the holding member is deformed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image heating apparatus for shortening a warm-up time, and more particularly, to an image heating apparatus suitable for an image forming apparatus such as an electrophotographic apparatus and an electrostatic recording apparatus which is suitable for fixing an unfixed image. The present invention relates to an apparatus and an image forming apparatus using the same.

[0002]

2. Description of the Related Art An image heating apparatus using electromagnetic induction is disclosed in
-295414 and JP-A-11-135246
No. 6,009,045.

FIG. 26 is a sectional view of an image heating apparatus disclosed in Japanese Patent Application Laid-Open No. 7-295414, and FIG.
2 shows a perspective view of the heating coil. As shown in FIG. 26, the heating roller 201 rotates in the direction of the arrow in the drawing while being in contact with the pressure roller 202, and heats the paper 203, which carries toner on its surface, between the rollers 201 and 202. Pressure fixing. The heating coil 204 is disposed inside the insulating support 205 in a buried state. The heating coil 204 has a narrow conductive film disposed along a semi-cylindrical curved surface of the insulating support 205. The heating coil 204 is supplied with alternating current from an induction heating power supply. This alternating current generates an alternating magnetic flux between the heating coil 209 and the heating roller 201, exciting the heating roller 201 and generating an eddy current. Joule heat is generated by the eddy current, and the heating roller 201 generates heat.

FIG. 28 is a sectional view of an image heating apparatus disclosed in Japanese Patent Application Laid-Open No. 11-135246. In the figure, 2
20 is a magnetic field generating means for generating a high frequency magnetic field,
Is a heating roller that generates heat by induction heating and rotates in the direction of the arrow. The pressure roller 222 rotates in the direction of the arrow in the figure. The recording material 224 carrying the unfixed toner image 223 is conveyed as indicated by the arrow in the drawing, and the toner image is fixed at the nip. The magnetic field generating means 220 includes an exciting coil 227 incorporated in the magnetic core 226. Further, except for the magnetic field generating means 220, a fixing unit including the heat roller 221 and the pressure roller 222 can be pulled out of the apparatus main body.

[0005]

However, the image heating apparatus disclosed in Japanese Patent Application Laid-Open No. 7-295414 has the following problems.

First, as the temperature rises, the support member is deformed, and the distance between the coil and the heat generating member changes, thereby resulting in an uneven heat generation distribution in the axial direction. Further, the conductive film buried in the support may be cut due to a difference in thermal expansion coefficient between the support member and the conductive film.

Further, there is a problem that a lump of toner or foreign matter is conveyed from the fixing nip by rotation of the heat generating member and is caught between the heat generating member and the support, thereby damaging the fixing surface.

Further, since the heating roller is surrounded by a semicircular coil, it is difficult to remove the heating roller from the coil from a state in which the heating roller is incorporated in the apparatus. For this reason, the heating roller and the coil may come into contact with each other at the time of attachment / detachment and damage the surface, which may cause disconnection of the coil and unevenness of the fixing surface appearing in an image.

Next, the image heating apparatus disclosed in Japanese Patent Application Laid-Open No. H11-135246 has the following problems. That is, the winding of the coil may be loosened due to the vibration caused by the movement of the coil and the fixing member. In the configuration shown in FIG.
Because the coil is directly opposite the heating element, the loose winding contacts the rotating heating element. If the insulation coating of the coil is broken at the contact portion due to sliding with the heat generating roller, the current flowing through the coil leaks and other electric circuits are damaged. Further, when the heat generating member is mounted, the loose winding may interfere with the heat generating member, and may hinder the mounting of the heat generating member to a regular position.

Further, it is difficult to form a smooth surface on the surface of the coil composed of the windings, and it is impossible to reduce the distance between the coil and the heat generating member. In addition, the temperature of the coil and the core rises because the heating member and the exciting means are directly opposed. Thereby, the electric resistance of the coil increases, and the magnetic permeability of the core decreases. Therefore, the efficiency of inputting electromagnetic energy from the coil to the heat generating member is reduced.

The present invention solves the problems associated with these conventional image forming apparatuses.

[0012]

According to the present invention, there is provided an image heating apparatus comprising: an endless heat generating member; and an exciting means for orbiting along the peripheral surface of the heat generating member for inductively heating the heat generating member. And a holding member made of an insulating and non-magnetic material for holding the exciting means, wherein the holding member has an axial gap at least in part. With this configuration, even if the holding member thermally expands, it is possible to suppress the deformation of the heat generating roller of the exciting unit in the radial direction. Thereby, it is possible to prevent the exciting means and the holding member from contacting the heat generating roller, and at the same time, to prevent the interval between the exciting means and the heat generating member from being changed, thereby preventing heat generation unevenness.

Further, since the holding member is divided into a plurality of parts in the axial direction and arranged with at least one gap, it is possible to completely absorb the thermal expansion of the holding member.

Further, the image heating apparatus of the present invention has an endless heat generating member, exciting means for inductively heating the heat generating member from the outside, and an insulating member which is located at a position opposite to the exciting means and the heat generating member and holds the exciting means. A holding member made of a conductive and non-magnetic material, and the holding member has a mounting portion fixed to the main body near both ends, and the mounting portion generates heat more than a back surface that does not face the heat generating member of the excitation means. It is close to a member. With this configuration, even if the holding member thermally expands, it is possible to suppress the deformation of the heat generating roller of the exciting unit in the radial direction. Thereby, it is possible to prevent the exciting means and the holding member from contacting the heat generating roller,
At the same time, it is possible to prevent the occurrence of uneven heating due to a change in the distance between the exciting means and the heating member.

Further, the image heating apparatus of the present invention comprises an endless heating member, an exciting means for inductively heating the heating member, and a holding member made of an insulating and non-magnetic material for holding the exciting means. The member has an attachment portion fixed to the main body near both ends, and at least one attachment portion is movable in the axial direction of the heat generating member. With this configuration, even if the holding member thermally expands, it is possible to suppress the deformation of the heat generating roller of the exciting unit in the radial direction. Thereby, it is possible to prevent the exciting means and the holding member from contacting the heat generating roller, and at the same time, to prevent the interval between the exciting means and the heat generating member from being changed, thereby preventing heat generation unevenness.

Further, in the image heating apparatus according to the present invention, the holding member is located at a portion facing the exciting means and the heat generating member. In this configuration, since the holding member is close to the heat-generating member, the temperature of the holding member is easily increased, and the thermal expansion increases.
The holding member is easily deformed in the radial direction of the heating roller. Further, since the holding member prevents the heat generating member from directly contacting the exciting means, it is possible to prevent the leakage of current from the exciting means to the heat generating roller.

Further, the image heating apparatus of the present invention is provided with a rotatable endless heating member, exciting means for inductively heating the heating member from the outside, and an opposing portion between the exciting means and the heating member,
A holding member made of an insulating and non-magnetic material for holding the exciting means, and a pressure roller for pressing against the heating member; and a pressure contact portion with the pressure roller in a rotating direction of the heating member and a facing portion for the exciting means. A cleaning means for cleaning the surface of the heat generating member is provided between them. With this configuration, it is possible to prevent a foreign substance or a lump of toner from being caught between the holding member and the heat generating member.

Further, the image heating apparatus of the present invention has a heating member made of a conductive material, exciting means for inductively heating the heating member, and an exciting means which is located at a position opposite to the exciting means and the heating member. A holding member made of an insulating non-magnetic material, an endless fixing member that is inscribed in the heating member and rotatably supported, and a pressure roller that circumscribes the fixing member. A cleaning unit for cleaning the surface of the fixing member is provided between a contact portion with the pressure roller and a facing portion with the exciting unit in the rotation direction. With this configuration, it is possible to prevent foreign matter and a lump of toner from being caught between the holding member and the fixing member.

Further, the image forming apparatus of the present invention is characterized in that the image heating device comprises a toner image forming means for forming a toner image on a sheet-like recording medium and an image heating device having the above-mentioned configuration. This is to heat and fix the toner image on the medium.

Further, in the image forming apparatus of the present invention, the endless heat generating member, the exciting means for inductively heating the heat generating member from the outside, and at least a part thereof are located at a portion facing the exciting means and the heat generating member. A holding member made of an insulating and non-magnetic material for holding the heating member, the heating member and the excitation means being detachable, and having a heating member guiding means for guiding the movement of the heating member. With this configuration, the heat generating member can be easily replaced while leaving the exciting means. Further, the temperature rise of the exciting means can be prevented by the holding member, and at the same time, the exciting means can be stably opposed to the heating member. Further, since the holding member is non-magnetic and insulating, it does not affect electromagnetic induction.

Furthermore, the heat generating member of the exciting means faces the outer surface of the heat generating member, and the exciting means moves between the first position and the second position in conjunction with opening and closing of the door of the main body. The degree of freedom in the direction in which members can be easily attached and detached is increased. In addition, it is possible to prevent the heat generating member and the exciting means from being damaged at the time of attachment / detachment, and to facilitate the processing at the time of winding the paper.

Further, the holding member is provided with a biasing means for biasing the holding member in the direction of the heat generating member, and a parallel guide for guiding the holding member so as to move in parallel in the radial direction of the curvature of the facing portion of the heat generating member. The heating member can be easily attached and detached even when the facing angle between the member and the heating member is large.

Further, the surface of the holding member facing the heat generating member is a circular arc surface along the heat generating member, and the heat generating member is detachable in the axial direction with respect to the exciting means, so that the distance between the coil and the heat generating member is reduced. And high power can be obtained with small current.
The heating member can be easily attached and detached.

Also, the surface of the exciting means facing the heat-generating member is along the outer surface of the heat-generating member, and the heat-generating member guide means moves the heat-generating member at least in the vicinity of the exciting means in the opening direction of the exciting means, thereby reducing the current. Therefore, it is easy to replace the heat generating member while obtaining a large amount of supplied heat.

Further, the heat generating member includes at least a flexible conductive belt, and has a belt supporting member for rotatably suspending the conductive belt, and the exciting member is connected to the exciting means at a position where the conductive belt is suspended on the belt supporting member. The support member and the conductive belt are opposed to each other, and are integrally detachable with respect to the exciting means. The moving direction of the belt support member facing the exciting means at the time of attachment and detachment coincides with the suspension direction of the conductive belt. With this configuration, it is easy to attach and detach the fixing device including the conductive belt while using the belt fixing device having a small heat capacity and a fast temperature rise.

The heat generating member rotatably suspends a flexible fixing belt, and the heat generating member and the fixing belt can be integrally attached to and detached from the exciting means. The fixing belt is configured to coincide with the suspension direction of the fixing belt. With this configuration, it is easy to attach / detach the fixing device including the fixing belt while using a resin fixing belt that has a longer service life than the metal film and has a small heat capacity and a rapid temperature rise.

Further, the image forming apparatus of the present invention has at least one endless flexible fixing member rotatably suspended on a plurality of supporting members, and exciting means facing the outer peripheral surface of the fixing member. Part is located at the opposite part of the excitation means and the heat generating member,
A holding member made of an insulating and non-magnetic material for holding the exciting means is provided, and the supporting member and the fixing member are integrally detachable from the exciting means. With this configuration, the fixing device including the fixing member can be easily attached and detached while having a small heat capacity and a fast temperature rise. In particular, since a flexible fixing member has a short life and is frequently attached and detached, it is very useful that the fixing member and the heat generating member can be exchanged without leaving the exciting means.

Further, in the portion where the fixing member is suspended from the supporting member among the plurality of supporting members, the exciting member is opposed to the fixing member, so that the fixing member can be opposed at a portion where the shape is stable. This makes it easy to bring the excitation means close to the heat-generating member, so that large power can be obtained with detailed conduction. Further, it is possible to prevent the fixing member and the holding member from coming into contact with each other when the holding member is moved.

Further, according to the image forming apparatus of the present invention, an endless and flexible fixing member rotatably suspended on a plurality of supporting members, and a fixing to a first supporting member among the plurality of supporting members. On the outer peripheral surface of the suspension portion of the member, the exciting means is an exciting means facing the fixing member, a moving means for holding the first support member movably with respect to the other support members, and the first support member. There is provided an urging means for urging the fixing member with tension in a predetermined direction, and the exciting means is movably held together with the first support member. With this configuration, even if the peripheral length of the fixing member varies or changes with time, the positional relationship between the exciting unit and the heat generating member opposed thereto can be kept constant.

Further, the image forming apparatus of the present invention includes an endless heat generating member, exciting means constituted by at least a litz wire for inductively heating the heat generating member, and a power supply substrate for applying an induced current to the exciting means. The heating member and the exciting means are detachably configured, and the end of the litz wire is directly connected to the power supply board. With this configuration, it is not necessary to cut the litz wire halfway, so that a connector that generates a large electrical resistance to high-frequency current is not required. Therefore, even if the litz wire is used, it is possible to prevent the loss of electric power in the excitation unit by replacing only the heat generating member.

[0031]

(Embodiment 1) FIG. 1 shows a first embodiment of the present invention.
FIG. 3 is a side sectional view illustrating a configuration of the image forming apparatus according to the exemplary embodiment.
FIG. 2 is a cross-sectional view of the image heating apparatus according to the first embodiment of the present invention, FIG. 3 is a projection view of the image heating apparatus as viewed from the direction indicated by the arrow A in FIG. It is sectional drawing of an apparatus.

In FIG. 1, reference numeral 1 denotes an electrophotographic photosensitive member (hereinafter, photosensitive drum). The surface of the photosensitive drum 1 is uniformly charged by the charger 2 while being driven to rotate at a predetermined peripheral speed in the direction of the arrow. A laser beam scanner 3 outputs a laser beam 4 corresponding to a signal of image information. A surface of the charged photosensitive drum 1 is irradiated with a laser beam 4
Are scanned and exposed to form an electrostatic latent image on the photosensitive drum 1. The developing device 5 includes a developing roller 6 that is driven to rotate.
Having. The developing roller 6 has a thin layer of toner formed on the outer peripheral surface thereof, and is opposed to the photosensitive drum 1 to which a developing bias voltage is applied. The electrostatic latent image on the photosensitive drum 1 is developed by the toner of the developing device 5 to form a toner image.

On the other hand, the recording paper 8 is fed one by one from the paper feed unit 7 to the nip between the photosensitive drum 1 and the transfer roller 10 via the registration roller pair 9 at an appropriate timing.
Then, the toner image 11 is transferred from the photosensitive drum 1 onto the recording paper 8 by the transfer roller 10 to which the transfer bias is applied. After the separation of the recording paper 8, the surface of the photosensitive drum 1 is cleaned by a cleaning device 12 to remove residues such as untransferred toner, and is repeatedly used for the next image formation.

Reference numeral 13 denotes a fixing paper guide for guiding the movement of the recording paper 8 to the fixing device 14 after the transfer. The recording paper 8 onto which the toner image 11 has been transferred is conveyed to a fixing device 14 which is an image heating device, where the toner image is fixed. A paper discharge guide 15 guides the recording paper 8 that has passed through the fixing device 14 to the outside of the apparatus. The recording paper 8 on which the image is fixed and the image is fixed is discharged to a discharge tray 16. 17 is an exterior plate of the apparatus main body. Reference numeral 18 denotes a fixing door for attaching and detaching a fixing device and performing paper jam processing. The fixing door 18 has a hinge 19
It is opened and closed by rotating around.

Next, the fixing device 14 which is an image heating device of this embodiment will be described in detail with reference to FIG.

In FIG. 2, a thin fixing belt 20 is an endless fixing belt made of a polyimide resin and has a diameter of 50 mm and a thickness of 100 μm. The surface thereof is coated with a 20 μm-thick release layer made of a fluororesin in order to impart release properties. As a material of the base material, a very thin metal such as nickel manufactured by electroforming can be used in addition to heat-resistant polyimide and fluororesin. The release layer on the surface is made of PTFE, PFA, FEP, silicone rubber,
A resin or rubber having good releasability such as fluororubber may be coated alone or as a mixture.

Reference numeral 21 denotes a heat generating roller having a diameter of 20 mm.
With a thickness of 0.3 mm and a carbon content of 0.05
% To 0.5% of a carbon steel, and is manufactured so as to have a Curie point of 300 ° C. or higher.

Reference numeral 22 denotes a diameter 20 made of a resilient foam silicon rubber having a low hardness (JISA 20 degrees).
mm is a low heat conductive fixing roller. Fixing roller 22
Is rotationally driven by a driving unit of the apparatus main body (not shown). The fixing belt 20 is suspended between the fixing roller 22 and the heat generating roller 21 with a predetermined tension, and is rotatable in the direction of arrow B. Both ends of the heating roller 21 are provided with meandering preventing ribs (not shown) of the fixing belt 20.

Reference numeral 23 denotes a pressure roller as a pressure means, which is made of silicone rubber having a hardness of JISA 65 degrees, and presses against the fixing roller 22 with a pressing force of 150 N via the fixing belt 20 as shown in FIG. Has formed. In this state, the pressure roller 23 is driven to rotate by the rotation of the heating roller 21. The material of the pressure roller 23 is other fluoro rubber,
It may be made of heat-resistant resin such as fluororesin or rubber. The surface of the pressure roller 23 may be coated with a resin or rubber such as PFA, PTFE, FEP, or the like, alone or in combination, in order to enhance abrasion resistance and releasability.

Next, the configuration of the exciting means 24 will be described with reference to FIGS.

Reference numeral 25 denotes a coil, which is formed by extending a wire bundle of 60 wires made of a copper wire having an outer diameter of 0.2 mm and insulated on the surface in the axial direction of the heat generating roller 21 and rotating. The sectional shape of the coil 25 is as shown in FIG.
The fixing belt 20 is formed so as to cover the fixing belt 20 wound therearound. The wire bundle is wound around the heat roller 21 nine times with only the ends overlapping and along the circumferential direction of the heat generating roller 21. At the end, the wire bundles overlap in two rows and rise to form a saddle-like shape as a whole. At both ends of the coil guide 28, there are both end regulating portions 28a for regulating the raised coil 25,
The outer width of the coil 25 is defined.

The coil 25 faces the outer peripheral surface of the heat roller 21 at a distance of about 2 mm. The range in which the coil 25 faces is about 180 degrees with respect to the center axis of the heat roller 21.
It is a wide range.

Reference numerals 26 and 27 denote back cores made of a material having a high magnetic permeability such as ferrite.
Consists of The C-shaped core 27 has a width of 10 mm and a heat generating roller 2.
Seven coils are used at an appropriate interval in one axial direction to induce a magnetic flux outside the coil 25. As shown in the drawing, the center core 27 has a convex shape with respect to the C-shaped core 26 and is close to the heat roller 21. The cross-sectional shape of the central core 27 is 3 mm × 10 mm.

Reference numeral 28 denotes a holding member having a thickness of 1 mm.
The coil guide is made of a resin having a high heat-resistant temperature such as PEEK material or PPS and holds the coil and the back core. The material of the coil guide 28 is not limited to these as long as it has heat resistance, insulation, and non-magnetism. The distance between the coil guide 28 and the peripheral surface of the fixing belt 20 is set to 1 mm.

The coil guide 28 is screwed to the support member 29 at the position shown by the broken line D on the side of the facing portion facing the heat generating member and the end regulating portion 28a as a protruding portion formed at both ends thereof. The position of the fixing portion is determined by the end regulating portion 28.
a is set closer to the opposite portion than the upper end of a,
Further, in the radial direction of the heat roller 21, the position is closer to the peripheral surface of the heat roller 21 than the outermost part of the coil 25. More preferably, the position is closer to the center of the heat roller 21 than the outermost part of the coil 25 in the radial direction of the heat roller 21.

In FIG. 3, reference numeral 30 denotes a connector at both ends of the coil, and reference numeral 31 denotes an excitation circuit board having a semi-resonant inverter for applying a high-frequency current of 20 kHz to 50 kHz to the coil. As shown, the connector 30 at the end of the coil 25 is directly connected to the excitation circuit board 31. The maximum amplitude of the high-frequency current is a large current of about 50A. The alternating current applied to the coil 25 is applied to the fixing belt 20 at a predetermined fixing temperature of 19 degrees Celsius based on a temperature signal obtained by a temperature sensor (not shown) provided on the back surface of the fixing belt 20.
It is controlled to be 0 degrees.

In this embodiment, the recording paper having the A3 width (297 mm) is used as the recording paper having the maximum width.

With the configuration of the exciting means 24 and the heat roller 21, the coil 25 causes the heat roller 21 to generate heat by electromagnetic induction. The operation will be described below with reference to FIG.

In FIG. 2, the magnetic flux generated by the coil 25 enters the heat generating roller 21 from the C-shaped core 26 and travels in the circumferential direction due to the ferromagnetic property of the heat generating roller 21 as shown by a broken line E. Then, returning from the central core 27 to the C-shaped core 26, a large loop is formed and the generation and disappearance are repeated. Joule heat is generated by the induced current generated by the change in magnetic flux. By providing the cores 26 and 27, the connection with the heat generating roller 21 is improved. Therefore, a large amount of electric power can be supplied to the heat generating roller 21 even with the same coil current.

The cores 26 and 27 are made of a material having a magnetic permeability of 1
2,000-3000, saturation magnetic flux density 200-300m
T, ferrite having a volume resistivity of 1 to 10 Ω-m is used, but a material having a high magnetic permeability and a high resistivity such as permalloy can be used.

Since a space is provided between the plurality of C-shaped cores 26, heat does not accumulate in the coil 25. Further, there is nothing that hinders heat radiation from the outer periphery of the C-shaped core 26 and the coil 25. For this reason, it is possible to prevent the saturation magnetic flux density of the ferrite from decreasing due to the temperature rise due to heat storage, and the magnetic permeability as a whole from suddenly decreasing. Further, it is possible to prevent the wires from being short-circuited due to melting of the insulating coating of the wires. Thereby, the heat generating roller 21 can be stably maintained at the predetermined temperature for a long time.

Since the heat generating roller 21 is located inside the fixing belt 20 and the exciting means 24 is installed outside, the exciting means 24 is hardly heated by the influence of the temperature of the heat generating portion. It can be kept stable. Further, since the magnetic flux penetrates a wide range of the heat roller 21, a sufficient amount of heat can be obtained with a small eddy current density.

Next, the configuration of the fixing device will be described with reference to FIG.

In FIG. 4, reference numeral 22a denotes a rubber layer on the surface of the fixing roller, and 22b denotes a core metal of the fixing roller. Both ends of the core bar 22b are rotatably supported by a fixing bearing 34 composed of a bearing fixed to the fixing side plate 33.
The fixing roller 22 is driven to rotate by a driving mechanism (not shown). Reference numeral 35 denotes a central shaft that supports the heat roller 21.
It is fixed to a movable side plate 36 movable with respect to the fixing side plate 33. Reference numeral 37 denotes a flange made of a non-magnetic heat-resistant resin such as PPS or PEEK which has low thermal conductivity and is fixed to the heat roller 21 to support the heat roller 21 so as to be rotatable about a central axis 35. Numeral 38 denotes a tension spring which urges the movable side plate 36 in a direction away from the fixing device side plate 33, and applies a tension of 20N to the fixing belt 20 suspended between the heat generating roller 21 and the fixing roller 22.

The pressing spring 39 urges the mounting member 29 on which the coil guide 28 is mounted toward the heat generating roller 21. The mounting member is in contact with the movable side plate, and the gap between the heat generating roller 21 and the coil 25 and the coil guide 28 is determined.
It defines the positional relationship. The cleaner roller 400 is configured such that the fixing nip and the exciting coil 2 are rotated in the rotation direction of the fixing belt.
The fixing belt 20 is disposed so as to be in pressure contact with the fixing belt 20.

Next, the attaching / detaching operation of the fixing unit 14 will be described with reference to FIGS.

FIG. 5 is a side view showing an attaching / detaching operation of the image heating apparatus according to the first embodiment of the present invention, and FIG. 6 is a side view of a door opening / closing mechanism of the image forming apparatus according to the first embodiment of the present invention. .

The broken lines in the figure show the position of the fixing unit 14 in the operating state (image heating position) and the position of the coil guide 28 in the operating state (exciting position for exciting the fixing belt).
On the other hand, the solid line indicates the position during the attaching / detaching operation of the fixing device 14 and
4 shows a position of the coil guide 28 in a non-operating state (a non-exciting position where the excitation of the fixing belt is not performed).

Reference numeral 40 denotes a movement guide which holds the mounting member so as to be movable in the radial direction of the heat roller 21 at the operating position. Reference numeral 41 denotes a center shaft guide, which is provided on the main body side plate 42,
When the fixing device 14 is attached or detached, the central shaft 35 is
Guide in the direction of movement in the radial direction. Reference numeral 43 denotes a fixing guide, which is provided on the main body side plate 42 and guides the end of the fixing roller 22 in the moving direction when the fixing device 14 is attached or detached. The fixing guide may be configured to guide a part of the fixing side plate. Both the central shaft guide 41 and the fixing guide 43 have wide openings so that the insertion operation at the time of mounting can be easily performed.
The opening at one end of both guides 41 and 43 is
4 corresponds to a removal position for removing the device 4 from the apparatus main body.

In FIG. 6, reference numeral 44 denotes a semi-circular gear provided on the hinge 19 of the fixing door 18, which rotates as the fixing door 18 opens and closes. A link gear 45 meshes with the semicircular gear 44. 46 is a link pin fixed to the link gear 45. A link arm 47 is rotatably attached to a link pin 46. Reference numeral 48 denotes a mounting member pin which is fixed to the mounting member and rotatably holds the link arm 47.

When the fixing door 18 is released, the semicircular gear 4
4. The link gear 45 rotates, and the mounting member 29 supporting the coil guide 28 moves in the direction of arrow F. For this reason,
The coil guide 28 moves to the solid line position (non-excited position) in FIG.
Retreat above the top of 0. For this reason, the fixing device 1
4 can be easily pulled out in the horizontal direction perpendicular to the axis (the direction of arrow G in the figure). The fixing device 14 includes a pressure roller 23 supported by the fixing side plate, a fixing cleaner 400, and the moving side plate 3.
6. The heat generating roller 21, the tension spring 38, and a temperature sensor and a casing (not shown) are integrally attached to and detached from the apparatus main body.

The fixing belt 20 has a life of about 100,000 sheets, which is shorter than the life of the apparatus body. For this reason, the fixing device 1
4 needs to be replaced. Further, even when the surface of the fixing belt 20 is damaged during processing of paper jam, the fixing belt 20 needs to be replaced.

In the configuration of the present embodiment, the exciting means and the coil guide 28 move to the retracted position (non-excited position) in conjunction with the opening and closing of the fixing door 18, so that the semicircular shape with good magnetic coupling with the heat generating roller 21 is provided. Even if a coil is used, replacement of the fixing belt 20 is easy. Further, since the exciting means 24 remains in the apparatus main body, the cost of the fixing device 14 as a replacement part can be reduced.

The retracted position is not limited to the non-excited position, but may be a position that can be excited. In short, the retracted position may be a position different from the excited position during operation.

Further, since the coil 25 is not attached to or detached from the excitation circuit, it is possible to stably and surely contact the connector through which a large current flows. In general, the connector portion has a smaller specific surface area of the current path than the litz wire, so that the connector portion generates a large amount of heat with respect to a high-frequency current. In this embodiment, the connection portion between the excitation circuit board and the coil 25 is only one portion of the connector, and there is no portion connecting the litz wires in the middle. This does not impair the advantage of the Litz wire, which uses a bundle of a plurality of thin wires subjected to insulation coating, that is, low electrical resistance to high-frequency current.

The fixed portion of the coil guide 28 is located closer to the center of the heat roller 21 than the outermost part of the coil 25 in the radial direction of the heat roller 21. With this configuration, even if the coil guide 28 expands due to the heat of the heat generating roller 21, the deformation of the holding portions at both ends does not affect the deformation of the central portion of the coil guide 28. Therefore, it is possible to suppress deformation of the heat generating roller 21 at the center of the coil guide 28 in the radial direction.

FIG. 7 is a cross-sectional view showing a state of deformation after long-time use, assuming that the coil guide 28 is fixed at the upper end positions of the protruding portions at both ends. In this case, when the coil guide 28 expands, the holding portions at both ends of the coil guide 28 also deform as shown in the figure, and the central portion of the coil guide 28 largely deforms in the radial direction of the heat roller 21. For this reason, there is a problem that the coil guide 28 comes into contact with the fixing belt 20 wound around the heat generating roller 21 and damages the fixing surface. Also, even if it does not contact the fixing belt 20,
When the coil guide 28 is deformed, the distance between the coil 25 and the core held by the coil guide 28 and the heating roller 21 changes. When this distance changes, the amount of heat generated by electromagnetic induction changes. Therefore, the coil guide 28 is
The amount of heat generated in the portion close to the fixing belt 20 increases, and the fixing belt 20 becomes uneven in temperature.

Therefore, by preventing the deformation of the coil guide 28, it is possible to prevent the temperature unevenness of the fixing belt 20 and to prevent the surface of the fixing belt 20 from being damaged.

A cleaner roller is provided between the fixing nip and the heat roller 21 in the rotation direction of the transfer belt. As a result, even if the foreign matter adhered to and carried on the recording paper or the recording paper itself adheres to the fixing belt 20 at the fixing nip, the foreign matter is removed by the cleaner roller. Do not enter narrow opposing parts. Accordingly, it is possible to prevent a situation in which a foreign substance bites into the gap between the fixing belt 20 and the coil guide 28 and damages the surface of the rotating fixing belt 20.

The cleaning member is not limited to the roller shape, but may be in contact with the cleaning blade 49 and a belt nip downstream of the fixing roller 22 as shown in FIG. Further, as shown in FIG. 9, a cleaner pad 50 made of a flexible member such as felt may be pressed against the cleaner holding member. Further, the cleaner member may be in the form of an endless belt or a long web.

Also, because of the belt configuration, the material and thickness of the heat generating roller 21 and the fixing belt 20 can be set independently of each other. Therefore, for the heat generating roller 21, an optimum material and thickness for heating the coil 25 by electromagnetic induction can be selected. Further, the material and the thickness of the fixing belt 20 can be set to the optimum material and thickness for performing the fixing.

Further, since the coil 25 and the back core 9 cover almost half of the circumference of the heat roller 21, the entire area of the contact portion between the fixing belt 20 and the heat roller 21 generates heat. Therefore, more heating energy transmitted from the coil 25 to the heat generating roller 21 by electromagnetic induction can be transmitted to the fixing belt 20.

In the present embodiment, in order to achieve the object of shortening the warm-up time, the heat capacity of the fixing belt 20 is set as small as possible, and the thickness and the outer diameter of the heat roller 21 are set small so that the heat capacity is set small. ing. For this reason, it was possible to achieve a predetermined temperature in about 15 seconds from the start of the temperature rise for fixing with the input power of 800 W.

In the present embodiment, the base material of the fixing belt 20 is made of resin. However, it is possible to use a ferromagnetic metal such as nickel instead.

The wire bundle is φ0.1 mm to 0.1 mm.
A structure in which 50 to 200 3 mm strands are bundled can be similarly configured. If the strand is φ0.01 mm or less, the wire may be broken by a mechanical load. Conversely, if the strand is 0.3 mm or more, the electrical resistance to high-frequency alternating current increases, and the heat generated by the coil 25 becomes excessive.

In this embodiment, the exciting coil 25 is moved in the radial direction of the heating roller 21.
If the facing angle with the heat generating roller 21 is smaller than 180 degrees, it is possible to move in a direction different from the radial direction.

In this embodiment, the fixing door has been described as an example of the opening / closing door of the apparatus main body. However, the present invention is not limited to this, and may be, for example, a front cover of the apparatus main body.

(Embodiment 2) FIG. 10 is a cross-sectional view of a fixing device as an image heating device according to a second embodiment of the present invention, and FIG. 11 is a cross-sectional view including a heat roller 21 and a central axis of a coil 25. Members having the same functions as in the first embodiment are given the same reference numerals, and description thereof will be omitted.

In this embodiment, unlike the first embodiment, the tension is applied to the fixing belt 20 by pressing the cleaner roller from outside the fixing belt 20 with a tension spring 51. The heat generating roller 21 is directly supported by a heat generating bearing 52 which is a bearing fixed to the fixing side plate. further,
The mounting member is brought into contact with the outer peripheral portion of the heat generating bearing, and the heat generating roller 2
1 and the positional relationship between the coil guide 28. Further, instead of the central shaft and the central shaft guide, a positioning pin 53 that fits into the support groove of the main body is provided on the fixing side plate. Although not shown, the position of the support groove of the main body is adjusted to the position of the positioning pin.

The other structure is the same as that of the first embodiment.

With the above configuration, the positions of the heat generating roller 21 and the fixing roller 22 are fixed and do not move. Since a structure for holding the heat roller 21 movably is not required, the structure for supporting the heat roller 21 is simple. This allows
The configuration of the fixing device 14 is simple and can be configured at low cost. Further, since the mounting member directly contacts the bearing of the heat generating roller 21, there are few members interposed for positioning. Thereby, the positional relationship between the coil 25 and the heat generating member can be accurately regulated.

(Embodiment 3) FIG. 12 is a cross-sectional view of a surface including a shaft of a heat generating portion of a fixing device as an image heating device. FIG. 13 is a sectional view of an image heating device according to a third embodiment of the present invention. It is sectional drawing in a perpendicular surface. Members having the same functions as in the second embodiment are given the same reference numerals, and description thereof is omitted.

In the present embodiment, unlike the second embodiment,
As shown in FIG. 12, the coil guide 28 is divided into a and b in the longitudinal direction. Further, instead of holding each of the coil guides 28 at both ends, a holding arm 55 having a mounting hole 54 is provided at a substantially central portion of each, and is screwed to a mounting member 56 fixed to the fixing side plate.

With this configuration, even if the temperature of the coil guide 28 rises due to the heat of the heat generating roller 21, the coil guide 28 can expand in the axial direction. This prevents the coil guide 28 from being deformed in the radial direction of the heat roller 21. When both ends of the coil guide 28 are fixed,
When the coil guide 28 expands, the central portion of the coil guide 28 is deformed in the radial direction of the heat roller 21 as shown in FIG. For this reason, the coil guide 28 is
There is a problem that the fixing belt comes into contact with the fixing belt 20 wound around the fixing member 1 and damages the fixing surface. Further, if the coil guide 28 is deformed even without contact with the fixing belt 20, the distance between the coil and the core held by the coil guide 28 and the heating roller 21 changes. When this distance changes, the amount of heat generated by electromagnetic induction changes. Therefore, the amount of heat generated in the portion where the coil guide 28 is close to the heat roller 21 increases, and the fixing belt 20 becomes uneven in temperature.

Therefore, by preventing the coil guide 28 from being deformed, it is possible to prevent the temperature unevenness of the fixing belt 20 and to prevent the surface of the fixing belt 20 from being damaged. Note that, in the present embodiment, the coil guide 28 is
Although it is divided, it is needless to say that it may be divided into more parts.

(Embodiment 4) FIG. 14 shows the center of an exciting coil 25 and a heat roller 2 of an image heating apparatus according to a fourth embodiment of the present invention.
FIG. 15 is a cross-sectional view taken along a plane perpendicular to the central axis of the heat generating roller 21. FIG. 16 is an enlarged view of holding portions at both ends of the coil guide 28 of the present embodiment. FIG. 16B is a cross-sectional view taken along a cutting line J, as viewed from the direction of arrow H in FIG. Members having the same functions as in the second embodiment are given the same reference numerals, and description thereof is omitted.

In the present embodiment, unlike the second embodiment,
As shown in FIG. 14, the heat generating roller 2 of the coil guide 28
A plurality of rectangular voids 57 are provided at one circumferential end so as to leave a gap in the longitudinal direction. Further, as shown in FIG. 16, the holding portions at both ends of the coil guide 28 are supported by being superimposed on a fixing portion 58 which is a part of the main body side plate. Further, the mounting hole 54 of the coil guide 28 is an elongated hole in the axial direction, and the mounting screw 59 is a stepped screw.

With this configuration, both ends of the coil guide 28 are supported so as to be movable in the axial direction. For this reason, even if the area near the center of the coil 25 of the coil guide 28 thermally expands, the mounting portions at both ends can move in the axial direction, so that the coil guide 28 can be prevented from being deformed in the radial direction of the heat roller 21. .

The circumferential end of the coil guide 28 has a gap in the axial direction.
Can expand in the axial direction even if the temperature rises due to the heat of the heat generating roller 21. This prevents the coil guide 28 from being deformed in the radial direction of the heat roller 21.

As in the third embodiment, by preventing the coil guide 28 from being deformed, it is possible to prevent the temperature unevenness of the fixing belt 20 and prevent the surface of the fixing belt 20 from being damaged.

The shape of the gap 57 in the axial direction at the circumferential end of the coil guide 28 is not limited to the rectangular shape shown in FIG. 14, but as shown in FIG. The length of the gap may be changed.

(Embodiment 5) FIG. 18 is a side view of a heat generating portion of a fixing device of an image heating apparatus according to a fifth embodiment of the present invention. FIG. 19 is a sectional view of a fixing device as an image heating device according to a fifth embodiment of the present invention, taken along the center line in FIG. Members having the same action as in the first embodiment are given the same reference numerals,
Description is omitted.

In the present embodiment, unlike the fourth embodiment, a heating fixing roller 60 having a release layer similar to that of the fixing belt 20 is formed on the surface of the heating roller 21, and a fixing nip is formed by directly pressing the pressure roller 23. ing. The pressure roller 23 has a bearing 61 movably supported by a long hole of the fixing side plate,
The pressing spring 62 urges the heating roller 21 toward the heating roller 21. The fixing side plates at both ends are fixed to a fixing bottom plate 63, and the fixing bottom plate, the fixing side plate, the pressure roller 23, and the heat roller 21 form an integral fixing unit. A fixing guide 6 for guiding the fixing bottom plate in the axial direction of the heating roller 21 is provided on the main body bottom plate 64.
5 is provided. The excitation means is fixed to the main body.

With this configuration, by moving the fixing unit in the axial direction, the fixing unit can be replaced while the exciting coil 25 is fixed to the main body. Since the exciting coil 25 is fixed to the main body, the exciting coil 25
Can be configured to be simple and inexpensive.

(Embodiment 6) FIG. 20 is a side sectional view of an image forming apparatus according to a sixth embodiment of the present invention, and FIG. Members having the same functions as those of the first embodiment are denoted by the same reference numerals, and description thereof is omitted.

In FIG. 20, the right side is the front of the color image forming apparatus, and a front door 66 is provided at the front. Reference numeral 67 denotes a belt unit, which is an intermediate transfer belt 68.
And the three support shafts that suspend it ==== and the cleaner 69
And are integrated. The belt unit can be attached to and detached from the main body from the front of the apparatus by opening the front door as shown in the figure.

On the left side of the figure, black, cyan, magenta,
Four yellow fan-shaped image forming units 70
Bk, C, M, and Y are arranged in the carriage 71 in an annular shape.

The image forming units Bk to Y can be attached to and detached from the inside of the apparatus from above the apparatus main body by opening an upper surface door 72 on the upper surface of the apparatus. When the carriage rotates, the image forming units Bk, C, M, and Y rotate around the non-rotating mirror 73. At the time of image formation, each of the image forming units Bk to Y is sequentially located at the image forming position P facing the intermediate transfer belt.

Next, the image forming process will be described. First, the carriage is rotated to move the first color yellow image forming unit Y to the image forming position P. The laser light is reflected by the mirror and is incident on the photosensitive drum at the image forming position P to form a latent image. The latent image is developed with the yellow toner of the developing unit facing the latent image. The toner image on the photosensitive member is primarily transferred to the transfer belt 43.

After the completion of the yellow toner image, the carriage 51 is rotated by 90 ° in the direction of the arrow to move the magenta image forming unit 50M to the image forming position P. Then, the same operation as the previous yellow is performed, and the magenta toner image is superimposed on the yellow toner image on the intermediate transfer belt. By repeating the same operation for cyan and black, a toner image in which four color toner images are superimposed on the intermediate transfer belt is completed.

The transfer roller is brought into contact with the intermediate transfer belt in synchronization with the leading end position of the fourth color black toner image on the intermediate transfer belt. Then, the recording paper 8 is transported to the nip between the transfer roller and the intermediate transfer belt, and the four color toner images are transferred to the recording paper 8. The recording sheet onto which the toner image has been transferred passes through the fixing device 1413 and is discharged. 2
The toner remaining after the next transfer is removed by the cleaner 71 which comes in contact with and separates from the intermediate transfer belt at the same time.

When the formation of one image is completed, the yellow image forming unit 50Y is moved to the image forming position to prepare for the start of the next image formation.

In the fixing device 14 shown in FIG. 21, reference numeral 60 denotes a heat fixing roller 22 in which carbon rubber, which is a conductive and ferromagnetic material, is coated with silicon rubber. Reference numeral 23 denotes a pressure roller 23 whose surface is coated with silicone rubber, and is urged toward the heat-fixing roller 22 by pressing means (not shown).
Reference numeral 35 denotes a central axis of the heat-fixing roller 22, and reference numeral 23b denotes a core metal of the pressure roller 23, both of which penetrate the fixing side plate and protrude outside the fixing side plate.

In FIG. 22, ==== is a positioning groove in which the central shaft 35 is fitted, and is provided on the side plate of the main body. As shown in FIG. 20, the fixing device 14 can be attached to and detached from the main body as an integrated unit including the heat-fixing roller 22 and the pressure roller 23 while leaving the exciting means in the main body. The positioning groove is formed so that its longitudinal direction is in the attaching / detaching direction (the direction of arrow K) of the fixing device 14 shown in FIG. 20, and the opening of the groove has a wide width so that the central axis can be easily inserted. Further, the opening direction of the substantially semicircular exciting means is made to coincide with the attaching / detaching direction of the fixing device 14.

With this configuration, by opening the fixing door 18 at the front of the main body, the fixing device 14 can be easily attached and detached in the direction perpendicular to the rotation axis. Since the excitation means is left in the main body,
The fixing device 14 can have a simple and inexpensive configuration. Further, in the entire apparatus, in addition to paper jam processing, replacement of the paper feed cassette, the intermediate transfer belt, and the image forming unit, replacement of the fixing device 14 can be easily performed from the front of the apparatus.

In this embodiment, the fixing device 14 including the heat generating fixing roller 22 as the heat generating member is linearly moved in the opening direction of the exciting means, but the heat generating roller 21 is moved in the opening direction only near the exciting means. Just move. Therefore, at a position where the heat generating roller 21 is apart from the exciting means, the center axis regulating groove can be formed not as a straight line but as a curved line or a broken line so as to make the direction in which the attaching / detaching operation is easier.

(Embodiment 7) FIG. 23 is a sectional view of a fixing device as an image heating device according to a seventh embodiment of the present invention. Members having the same action as in the fourth embodiment are given the same reference numerals,
Description is omitted.

In the present embodiment, unlike the fourth embodiment, the heat generating roller 21 which is induced to generate heat by the exciting means is a roller made of a ferromagnetic material, and the fixing belt 2020 is disposed between the heat generating roller 21 and the fixing roller 22 having a foamed rubber layer on the surface. , And the fixing belt 20 is pressed against the pressure roller 23 to form a fixing nip. The fixing belt 20 is configured by laminating 150 μm silicone rubber on a 90 μm polyimide base material. The direction in which the belt is stretched matches the direction in which the fixing device 14 is attached and detached. Further, the coil 2525 of the exciting means 24 is compressed to make the cross-sectional shape of the wire bundle substantially rectangular, and the orbiting wire bundle is completely adhered.

The other structure is the same as that of the sixth embodiment.

According to this embodiment, the belt-type fixing device 14
The fixing device 14 can be easily attached and detached in the direction perpendicular to the rotation axis by opening and closing the fixing door 18. Since the attaching / detaching direction, the opening direction of the exciting coil 25, and the extending direction of the fixing belt 20 match, even if the facing angle of the exciting means to the heat roller 21 is increased, the fixing device 14 does not move without moving the exciting means. Can be easily attached and detached.

(Embodiment 8) FIG. 24 is a sectional view of a fixing device as an image heating device according to an eighth embodiment of the present invention, and FIG. Members having the same functions as in the fourth embodiment are denoted by the same reference numerals, and description thereof will be omitted.

In the present embodiment, unlike the fourth embodiment, a temperature sensor as a temperature detecting means of the heat roller 21 is provided inside the fixing belt 20. The temperature sensor is attached to a sensor support plate 75. As shown in FIG. 25, the heating roller 21, the exciting means and the sensor support plate 75 are supported by the same movable side plate 36, and the movable side plate is
The fixing belt 20 is movable with respect to the fixing side plate 33 in the direction in which the fixing belt 20 is stretched, and is urged by a tension spring 51 in a direction away from the pressure roller 23.
N tension is applied. The fixing device 14 is a pressure roller 2
3. The heating roller 21, the temperature sensor, and the exciting means are integrally attached to and detached from the apparatus main body in the direction of the arrow.

According to the present embodiment, even if the position of the heat roller 21 fluctuates due to a change in the length of the fixing belt 20 or a variation in the perimeter between the individual belts and a difference between the fixing units 14, the heat is generated. The position of the roller 21, the exciting means and the temperature sensor can be stably held.

Further, the guide member and the coil 25 are configured to be in contact with each other, but the guide member and the coil 25 may be configured to be at least partially separated. In this case, since the airflow passes between the two, the heat radiation of the coil 25 can be promoted.

In the above embodiment, the holding member is provided on the side closer to the heat generating member with respect to the coil 25, but the holding member may be provided on the opposite side of the coil 25 with respect to the heat generating member. .

In the first to eighth embodiments, the heating element that generates heat by being excited by the excitation means is a flexible conductive belt (Examples 1 to 4) or a roller (Examples 5 to 8). ), But other forms are also possible. In Examples 1 to 7, a conductive belt or a roller as a heating element can be appropriately replaced.

[0117]

As described above, according to the present invention, even if the holding member of the exciting means thermally expands, the radial deformation of the exciting means and the heat generating member of the holding member can be suppressed. This allows
It is possible to prevent the exciting means and the holding member from contacting the fixing member and damaging the fixing surface. In addition, it is possible to prevent unevenness of the heat generation distribution caused by the deformation. Further, it is possible to prevent foreign matter from being caught between the holding member and the fixing member that is close to and facing the surface of the fixing member. Further, the fixing member can be easily replaced while maintaining a constant distance between the exciting means and the heat generating member.

[Brief description of the drawings]

FIG. 1 is a sectional view of an image forming apparatus according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view of the image heating apparatus according to the first embodiment of the present invention.

FIG. 3 is a projection view of a heating unit of the image heating apparatus according to the first embodiment of the present invention.

FIG. 4 is a cross-sectional view of the image heating device of the image heating device according to the first embodiment of the present invention.

FIG. 5 is a side view showing an attaching / detaching operation of the image heating apparatus according to the first embodiment of the present invention.

FIG. 6 is a side view of a door opening / closing mechanism of the image forming apparatus according to the first embodiment of the present invention.

FIG. 7 is a cross-sectional view of the holding member for describing deformation of the holding member not according to the present invention.

FIG. 8 is a side step view of another embodiment of the cleaner member according to the first embodiment of the present invention.

FIG. 9 is a side step view of still another embodiment of the cleaner member according to the first embodiment of the present invention.

FIG. 10 is a sectional view of an image heating apparatus according to a second embodiment of the present invention.

FIG. 11 is a sectional view of a heat generating portion of an image heating apparatus according to a second embodiment of the present invention.

FIG. 12 is a cross-sectional view of a surface including an axis of a heating unit of an image heating apparatus according to a third embodiment of the present invention.

FIG. 13 is a cross-sectional view taken along a plane perpendicular to the axis of a heating unit of an image heating apparatus according to a third embodiment of the present invention.

FIG. 14 is a sectional view of a plane including an axis of an exciting unit according to a fourth embodiment of the present invention;

FIG. 15 is a sectional view taken along a plane perpendicular to an axis of an exciting unit according to a fourth embodiment of the present invention.

FIG. 16 is an enlarged view of a holding portion of a holding member according to a fourth embodiment of the present invention.

FIG. 17 is a sectional view showing another embodiment of the holding member according to the fourth embodiment of the present invention.

FIG. 18 is a side view of an image heating apparatus according to a fifth embodiment of the present invention.

FIG. 19 is a sectional view of an image heating apparatus according to a fifth embodiment of the present invention.

FIG. 20 is a side sectional view of an image forming apparatus according to a sixth embodiment of the present invention.

FIG. 21 is a side sectional view of an image heating apparatus according to a sixth embodiment of the present invention.

FIG. 22 is a side view of the positioning groove of the central axis of the heat generating roller 21 according to the sixth embodiment of the present invention.

FIG. 23 is a sectional view of a heat generating portion of an image heating apparatus according to a seventh embodiment of the present invention.

FIG. 24 is a sectional view of a heat generating portion of an image heating apparatus according to an eighth embodiment of the present invention.

FIG. 25 is a projection view of a heat generating portion of an image heating apparatus according to an eighth embodiment of the present invention.

FIG. 26 is a cross-sectional view of a heat generating portion of a conventional image heating apparatus.

FIG. 27 is a perspective view of a heat generating portion of a conventional image heating device.

FIG. 28 is a cross-sectional view of a heat generating portion of another conventional image heating device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Photosensitive drum 2 Charger 3 Laser beam scanner 4 Laser beam 5 Developing device 6 Developing roller 7 Feeding section 8 Recording paper 9 Registration roller 10 Transfer roller 11 Toner image 12 Cleaning device 13 Paper guide 14 Fixing device 15 Discharge guide 16 Discharge Paper tray 17 Exterior plate 18 Fixing door 19 Hinge 20 Fixing belt 21 Heating roller 22 Fixing roller 23 Pressure roller 24 Exciting means 25 Coil 26 C-type core 27 Central core 28 Coil guide 29 Support member 30 Connector 31 Exciting circuit board 32 Temperature sensor ( (Not shown) 33 fixing side plate 34 fixing bearing 35 center axis 36 movable side plate 37 flange 38 tension spring 39 pressing spring 400 cleaner roller 40 moving guide 41 center axis guide 42 main body side plate 43 fixing guide 44 semicircular gear 45 link gear 6 Link Pin 47 Link Arm 48 Attachment Member Pin 49 Cleaning Blade 50 Cleaning Pad 51 Tension Spring 52 Heating Bearing 53 Positioning Pin 54 Attachment Hole 55 Attachment Arm 56 Attachment Member 57 Gap 58 Fixing Portion 59 Attachment Screw 60 Heating Fixing Roller 61 Pressure Roller Bearing 62 Press spring 63 Fixing bottom plate 64 Main body bottom plate 65 Fixing guide 66 Front door 67 Belt unit 68 Intermediate transfer belt 69 Support shaft 69 Cleaner 70 Image forming unit 71 Carriage 72 Top door 73 Mirror 74 Temperature sensor 75 Sensor support plate

Continued on the front page (72) Inventor Masaru Imai 1006 Kazuma Kadoma, Osaka Pref. Matsushita Electric Industrial Co., Ltd. 2H033 AA23 AA30 AA32 AA42 BA03 BA11 BA25 BA26 BA48 BB01 BB28 BE06 3K059 AA08 AB27 AD05 AD34 CD52 CD62 CD72 CD75

Claims (26)

[Claims] 1. An endless heat generating member, an exciting means which circulates along a peripheral surface of the heat generating member and inductively heats the heat generating member, and a holding member made of an insulating and non-magnetic material for holding the exciting means. An image heating apparatus comprising: a holding member having an axial gap in at least a part thereof. 2. The holding member is divided into a plurality in the axial direction,
The image heating apparatus according to claim 1, wherein the image heating apparatuses are arranged with at least one gap. 3. An endless heat-generating member, exciting means for inductively heating the heat-generating member from the outside, and an insulating non-magnetic material which is located at a position facing the exciting means and the heat-generating member and holds the exciting means. A holding member is provided, the holding member having a mounting portion fixed to the main body near both ends, wherein the mounting portion is closer to the heat generating member than to a back surface of the exciting means not facing the heat generating member. Image heating device. 4. An endless heat-generating member, exciting means for inductively heating the heat-generating member from the outside, and an insulating non-magnetic material which is located at a position opposite to the exciting means and the heat-generating member and holds the exciting means. A holding member, the holding member having a facing portion facing the heat generating member, and projecting portions projecting from both ends of the facing portion, and at least a part of a side surface of the projecting portion is attached to the apparatus main body. An image heating apparatus characterized in that: 5. The mounting part of the holding member,
The image heating apparatus according to claim 4, wherein the image heating apparatus is provided on a side closer to the opposing portion than the upper end of the protruding portion. 6. An endless heat generating member, an exciting means for inductively heating the heat generating member, and a holding member made of an insulating and non-magnetic material for holding the exciting means, wherein the holding member is attached to the main body near both ends. An image heating apparatus, comprising: a mounting portion fixed to the heating member, wherein at least one of the mounting portions is movable in an axial direction of the heat generating member. 7. The image heating apparatus according to claim 1, wherein the holding member is located at a position where the exciting member and the heat generating member face each other. 8. A rotatable endless heat generating member, exciting means for inductively heating the heat generating member from the outside, and an insulating and non-magnetic insulating member which is located at a position opposed to the exciting means and the heat generating member and holds the exciting means. A cleaning member that includes a holding member made of a material and a pressure roller that presses against the heating member, and that cleans a surface of the heating member between a pressing portion of the heating member and a portion facing the exciting unit in a rotation direction of the heating member. An image heating apparatus comprising: 9. A heating member made of a conductive material, excitation means for inductively heating the heating member, and an insulating non-magnetic material which is located at a position opposite to the excitation means and the heating member and holds the excitation means. A fixing member having an endless shape rotatably supported by being in contact with the heat generating member, and a pressure roller circumscribing the fixing member, wherein the pressure member contacts the pressure roller in the rotation direction of the fixing member. An image heating device provided with cleaning means for cleaning the surface of the fixing member between a portion of the fixing member and a portion facing the exciting means. 10. A toner image forming means for forming a toner image on a sheet-like recording medium, and the image heating device according to claim 1, wherein the toner on the recording medium is controlled by the image heating device. An image forming apparatus, wherein an image is heated and fixed. 11. An endless heat-generating member, exciting means for inductively heating the heat-generating member from the outside, and at least a part of the heat-generating member is located at a portion opposed to the exciting means and the heat-generating member. An image forming apparatus, comprising: a holding member made of the material described above; a heating member and an exciting unit being detachable; 12. The exciter is opposed to the outer surface of the exciter with the heat-generating member, and the exciter is moved between the first position and a second position different from the first position in conjunction with opening and closing of a door of the main body. The image forming apparatus according to claim 11, which moves. 13. A device according to claim 12, further comprising: urging means for urging the holding member in the direction of the heat generating member, and a parallel guide for guiding the holding member so as to move in parallel in the radial direction of the curvature of the facing portion of the heat generating member. Image forming apparatus. 14. The image forming apparatus according to claim 11, wherein the surface of the holding member facing the heat generating member is an arc surface along the heat generating member, and the heat generating member is detachable in an axial direction with respect to the exciting means. apparatus. 15. A heat-generating member, wherein a surface of the exciting means facing the heat-generating member is along an outer surface of the heat-generating member, and the heat-generating member guiding means moves the heat-generating member in the opening direction of the exciting means at least near the exciting means. The image forming apparatus according to claim 11. 16. A heating member comprising at least a flexible conductive belt and a belt supporting member for rotatably suspending the conductive belt, wherein the conductive belt is connected to the exciting means at a position where the conductive belt is suspended by the belt supporting member. Opposite, the support member and the conductive belt are integrally detachable with respect to the exciting means, and a moving direction at the time of attachment and detachment of the belt support member facing the exciting means coincides with a suspension direction of the conductive belt. The image forming apparatus according to claim 15, wherein: 17. A heating member rotatably suspends a flexible fixing belt, wherein the heating member and the fixing belt are integrally detachable from an exciting unit, and a moving direction of the heating member when attaching and detaching is set. The image forming apparatus according to claim 15, wherein the direction is the same as the suspension direction of the fixing belt. 18. An endless and flexible fixing member rotatably suspended on a plurality of support members, exciting means facing an outer peripheral surface of the fixing member, and at least a part of the exciting means and the heat generating member. An image forming apparatus comprising: a holding member made of an insulating and non-magnetic material for holding the exciting means, which is located at the facing portion, wherein the supporting member and the fixing member are integrally detachable from the exciting means. apparatus. 19. The image forming apparatus according to claim 18, wherein the exciting unit is opposed to the fixing member at a portion where the fixing member is suspended from the supporting member among the plurality of supporting members. 20. An endless, flexible fixing member rotatably suspended on a plurality of support members, and an outer peripheral surface of a portion of the suspension of the fixing member to the first support member among the plurality of support members. An exciting means in which the exciting means faces the fixing member, a moving means for holding the first support member so as to be movable with respect to another support member, and a biasing means for urging the first support member in a predetermined direction. An image heating apparatus comprising: an urging means for applying a tension to a fixing member; and an exciting means movably held together with the first support member. 21. An image forming apparatus comprising at least a heating element and an exciting unit for inductively heating the heating element from outside as an image heating apparatus, wherein the heating element and the excitation unit are configured as separate bodies. An image forming apparatus wherein the heating element is detachably attached to the apparatus main body in a state where the exciting means is attached to the apparatus main body. . 22. An image forming apparatus comprising at least a heating element and an exciting unit for inductively heating the heating element from the outside as an image heating device, wherein the heating element and the excitation unit are configured separately. And an exciter is separately attached to the main body of the apparatus, wherein the exciting means comprises: a first position for exciting the heating element;
The heating element is attached to the apparatus main body so as to take a second position different from the first position. The heating element is configured to heat an unfixed image on a sheet, and is detachable from the apparatus main body. An image forming apparatus, wherein the image forming apparatus is attached to an apparatus main body so as to be able to take a detached position. 23. An image forming apparatus comprising at least a heating element as an image heating device and an exciting unit for inductively heating the heating element from the outside, wherein the excitation unit includes an exciting position for exciting the heating element. An image forming apparatus provided in the apparatus main body so as to take a non-excited position where the heating element is not excited. 24. The image forming apparatus according to claim 23, wherein said exciting means is provided to take an excited position and a non-excited position in accordance with an opening / closing operation of an opening / closing door provided in the apparatus main body. 25. An image heating apparatus having at least a heating element and exciting means for inductively heating the heating element from the outside, wherein the image heating apparatus is detachably attached to an apparatus main body. At least one of the image heating devices is movably attached to a side plate of the image heating device. 26. An endless heat-generating member, an exciting means comprising at least a litz wire for inductively heating the heat-generating member, and a power supply substrate for applying an induction current to the exciting means, wherein the heat-generating member and the exciting means are detachable. The image forming apparatus is configured to be capable of being connected, and an end of the litz wire is directly connected to the power supply board.