JP2004252206A - Fixing device, image forming apparatus and method for image forming - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fixing device by which the deterioration of an image quality is prevented while shortening start-up time and also the running stability of a fixing belt is improved. <P>SOLUTION: In the fixing device by which an endless fixing belt 53 is supported so as to freely rotate and run by being guided by a nonrotary belt guide member and is heated by a heat source 54 and, on the other hand, a fixing nip N is formed with a pressing side member 35 by coming into contact with the pressing side member 35, the belt guide member is held in a noncontact state with the fixing belt in a recording medium feeding area. The belt guide member is provided with, for instance, a heat shielding member 50 to restrict a heating range by the heat source, a supporting member 51 to support an elastic member 61 and a guide member 52 to stop the fixing belt from coming into contact with the heat source due to deformation. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an image forming apparatus such as a copier, a printer, a facsimile, or a multifunction peripheral thereof. In particular, a toner image is sequentially formed on the image carrier by repeating charging, writing, development, transfer, and cleaning, and the toner image is sequentially transferred and fixed, and the image is recorded on a recording medium such as paper or an OHP film. The present invention relates to an electrophotographic image forming apparatus and an image forming method. In addition, the present invention relates to a fixing device that fixes an unfixed image transferred onto a recording medium to the recording medium in such an image forming apparatus and an image forming method.
[0002]
[Prior art]
Conventionally, an electrophotographic image forming apparatus mainly forms a fixing nip by pressing a pressure roller against a heating roller having a heat source such as a halogen heater therein, and transfers a toner image between the two rotating rollers. A roller fixing type heat fixing device that applies heat and pressure at a fixing nip to fix a transferred toner image on a recording medium while conveying the recording medium through the recording medium has been used.
[0003]
In recent years, in response to the demand for energy saving, which has become particularly strong in recent years, the power supply to the fixing device has been stopped when not in use and performed only when necessary, thereby reducing power consumption.
[0004]
In such an energy-saving fixing device, it is preferable that the fixing temperature is immediately reached when image formation is started. For this reason, for example, the thickness of the base of the heating roller has been reduced to 1 mm or less to reduce the thickness, to reduce the heat capacity, and to quickly raise the heating roller to the fixing temperature.
[0005]
However, if the surface of the heating roller does not have elasticity, it cannot adhere to the fixing surface and cannot follow irregularities on the surface of the recording medium, resulting in minute unevenness in gloss and image quality. Even when the problem is not so great in monochrome, it is indispensable to make the surface of the heating roller elastic in a color image forming apparatus.
[0006]
Therefore, in the roller fixing method, it has been difficult to prevent the image quality from deteriorating while shortening the startup time of the fixing device.
[0007]
[Patent Document 1] Japanese Patent Application Laid-Open No. 9-44014 [Patent Document 2] Japanese Patent Application Laid-Open No. 2002-148983 For example, as described in Patent Documents 1 and 2, a fixing method other than the roller fixing method is considered. However, it has been difficult to prevent the image quality from deteriorating while shortening the startup time of the fixing device.
[0008]
[Patent Document 3] Japanese Patent Application Laid-Open No. 14-214953 In a conventional image forming apparatus, as described in Patent Document 3, a non-rotating belt guide member and an elastic member are provided. The endless fixing belt is guided and rotatably supported, and the fixing belt is heated by a heat source, and a pressure roller contacts the elastic member via the fixing belt to form a fixing nip therebetween. Some devices include a fixing device.
[0009]
[Problems to be solved by the invention]
However, in such a fixing device, since the fixing belt comes into contact with the non-rotating belt guide member and the elastic member, the running stability of the fixing belt is hindered by friction, and the belt guide member removes heat of the fixing belt to fix the belt. There is a problem that the startup of the device is deteriorated.
[0010]
SUMMARY OF THE INVENTION Accordingly, a first object of the present invention is to provide a fixing device capable of preventing deterioration of image quality and improving running stability of a fixing belt while shortening a rise time.
[0011]
A second object of the present invention is to provide a fixing device capable of reducing the number of parts and reducing costs.
[0012]
A third object of the present invention is to provide a fixing device capable of effectively heating a fixing belt.
[0013]
A fourth object of the present invention is to provide a fixing device capable of improving belt heating efficiency.
[0014]
A fifth object of the present invention is to provide a fixing device capable of improving the safety and uniformly heating the fixing belt.
[0015]
A sixth object of the present invention is to provide a fixing device capable of improving heat resistance and eliminating the risk of ignition.
[0016]
A seventh object of the present invention is to provide an image forming apparatus including a fixing device that achieves the above object.
[0017]
An eighth object of the present invention is to provide an image forming method using a fixing device which achieves the above object.
[0018]
[Means for Solving the Problems]
Therefore, according to the first aspect of the present invention, in order to achieve the first object, the endless fixing belt is rotatably supported by being guided by a non-rotating belt guide member, and the fixing belt is driven by a heat source. In a fixing device in which a fixing nip is formed between the heating side and the pressing side member by contacting the pressing side member, the belt guide member is held in a non-contact manner with respect to the fixing belt in the recording medium conveyance region. It is characterized by.
[0019]
According to a second aspect of the present invention, in order to achieve the second object, in the fixing device according to the first aspect, the belt guide member supports an elastic member that contacts the pressure-side member via the fixing belt. It is a supporting member to perform.
[0020]
According to a third aspect of the present invention, in order to achieve the second object, in the fixing device according to the first aspect, the belt guide member guides the fixing belt to prevent deformation of the fixing belt and contact with a heat source. It is a member.
[0021]
According to a fourth aspect of the present invention, in order to achieve the third object, in the fixing device according to the third aspect, a through hole for heating the fixing belt through heat from a heat source is provided in the guide member. It is characterized by.
[0022]
According to a fifth aspect of the present invention, in order to achieve the third object, in the fixing device according to the third aspect, the guide member is formed of a wire.
[0023]
According to a sixth aspect of the present invention, in the fixing device according to the first aspect, the belt guide member also serves as a heat shielding member for limiting a heating range of the heat source in order to achieve the second object. Features.
[0024]
According to a seventh aspect of the invention, in order to achieve the fourth object, in the fixing device of the first aspect, a cover member is attached to a side facing the heat source to form an air layer on the heat shielding member. , Is characterized.
[0025]
According to an eighth aspect of the present invention, in order to achieve the fourth object, in the fixing device according to the first aspect, a heat insulating member is provided at a portion of the belt guide member where the fixing belt slides. And
[0026]
According to a ninth aspect of the present invention, in order to achieve the fifth object, the fixing device according to the first aspect includes a fixing belt stretched in a substantially cylindrical state and a heat source provided at a center position thereof. Features.
[0027]
According to a tenth aspect of the present invention, in order to achieve the sixth object, in the fixing device according to the first aspect, the fixing belt is made of a metal material having good thermal conductivity.
[0028]
According to an eleventh aspect of the present invention, there is provided an image forming apparatus including the fixing device according to any one of the first to tenth aspects, in order to achieve the seventh object.
[0029]
According to a twelfth aspect of the present invention, there is provided an image forming method for forming an image on a recording medium by fixing with the fixing device according to any one of the first to tenth aspects so as to achieve the eighth object. , Is characterized.
[0030]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 shows an overall schematic configuration of a color laser printer including a fixing device according to the present invention.
[0031]
Reference numeral 100 in the figure denotes a printer device main body. An intermediate transfer body 10 in the form of an endless belt is provided at the center of the printer apparatus main body 100 so as to be rotatable counterclockwise in the figure by being wrapped around rollers 12, 13, and 14. Of course, it may be wound around four or more rollers, or may be stretched almost horizontally in the illustrated example, but may be stretched diagonally instead of horizontally.
[0032]
In the illustrated example, a belt cleaning device 16 is provided near the one roller 12 for removing residual toner remaining on the intermediate transfer body 10 after image transfer.
[0033]
Under the intermediate transfer body 10 stretched right and left, four monochromatic image forming units 18C, 18M, 18Y, and 18K of cyan, magenta, yellow, and black are arranged side by side along the transport direction. A tandem imaging device 20 is provided. An exposure device 21 is further provided below the tandem image forming device 20.
[0034]
On the other hand, a secondary transfer device 22 is provided beside the roller 13. The secondary transfer device 22 presses the transfer roller 23 against the roller 13 via the intermediate transfer body 10 to form a transfer nip at the secondary transfer position, and transfers the image on the intermediate transfer body 10 to the recording medium P. Of course, a non-contact charger may be provided as the secondary transfer device 22 instead of the transfer roller 23.
[0035]
Now, below the exposure device 21, there is provided a medium storage cassette 24 for storing a recording medium P such as paper or OHP film. A delivery device 25 is provided at the upper right of the medium storage cassette 24. Then, beside the intermediate transfer member 10, the tandem image forming device 20, and the exposing device 21, which are stretched right and left, the recording medium conveying path 26 extends from the lower side to the upper side in the drawing from the sending device 25 through the secondary transfer position. Is provided.
[0036]
A registration roller 27 is disposed upstream of the secondary transfer position along the recording medium transport path 26, and a fixing device 30 is provided downstream. The fixing device 30 will be described later in detail. A discharge roller 31 is provided further downstream of the fixing device 30, and a stack device 32 is provided on the printer apparatus main body 100 downstream thereof.
[0037]
By the way, when an image is formed using this color laser printer, one of the rollers 12, 13, and 14 is driven to rotate and the remaining rollers are driven to rotate by receiving a signal from a host (not shown). The intermediate transfer body 10 is transported.
[0038]
At the same time, the image carriers 40 are rotated by the individual monochrome image forming means 18 to form black, yellow, magenta, and cyan monochrome images on the image carriers 40, respectively. Then, as the intermediate transfer body 10 is transported, the single-color images are sequentially superimposed and primary-transferred to form a composite color image on the intermediate transfer body 10.
[0039]
Further, the delivery device 25 is driven at a predetermined timing to feed out the recording medium P from the medium storage cassette 24, enter the recording medium conveyance path 26, hit the registration roller 27 and stop.
[0040]
Then, the registration roller 27 is rotated in synchronization with the composite color image on the intermediate transfer body 10, and the recording medium P is sent to a secondary transfer position between the intermediate transfer body 10 and the secondary transfer device 22, and the secondary transfer is performed. The composite color image on the intermediate transfer body 10 is collectively and secondarily transferred by the transfer device 22 to form a color image on the recording medium P.
[0041]
The recording medium P after the image transfer is sent to the fixing device 30 and heat and pressure are applied by the fixing device 30 to fix the transferred toner image on the recording medium P. Then, the recording medium P is discharged by the discharge roller 31 and is stacked by the stacking device 32. Stack on top.
[0042]
On the other hand, the intermediate transfer member 10 after the image transfer is removed by the belt cleaning device 16 to remove the residual toner remaining on the intermediate transfer member 10 after the image transfer, and is prepared for the image formation by the tandem image forming device 20 again.
[0043]
Now, in the tandem image forming apparatus 20 described above, each monochromatic image forming means 18 includes a charging device 41, a developing device 42, a primary transfer device 43, a cleaning device 44, around a drum-shaped image carrier 40. An unillustrated static eliminator and the like are provided.
[0044]
Although not shown, a process cartridge is formed by all or a part of the portion constituting the single-color image forming means 18 so that the process cartridge can be collectively and detachably attached to the copying machine main body 100 to improve maintainability. Is also good.
[0045]
The charging device 41 of the portion constituting the monochrome image forming means 18 uses a charging roller in the illustrated example, and charges the image carrier 40 by contacting the image carrier 40 and applying a voltage.
[0046]
In the illustrated example, the developing device 42 uses a two-component developer composed of a magnetic carrier and a non-magnetic toner.
[0047]
The primary transfer device 43 has a roller shape, and is provided by pressing the intermediate transfer member 10 against the image carrier 40. Alternatively, the present invention is not limited to the roller shape, and may be a brush or a non-contact charger.
[0048]
The cleaning device 44 includes a cleaning member such as a cleaning blade or a cleaning brush in contact with the image carrier 40, and removes residual toner on the image carrier 40 with the cleaning member.
[0049]
The static eliminator (not shown) is, for example, a lamp, and irradiates light to initialize the surface potential of the image carrier 40.
[0050]
Then, with the rotation of the image carrier 40, the charging device 41 first uniformly charges the surface of the image carrier 40, and then receives a signal from the host, and in the above-described exposure device 21, writes in the above-described exposure device 21 using a laser, LED, or the like. The light L is reflected by the polygon mirror 46, further transmitted through the lens, reflected by the mirror, and irradiated on the image carrier 40 to form an electrostatic latent image on the image carrier 40.
[0051]
Thereafter, the electrostatic latent image is visualized by attaching toner with the developing device 42, and the visible image is transferred onto the intermediate transfer body 10 by the primary transfer device 43. The surface of the image carrier 40 after the image transfer is cleaned by removing the residual toner by the cleaning device 44, and the charge is removed by the charge removing device to prepare for the image formation again.
[0052]
Reference numeral 48 in the figure denotes a toner container for storing toner, and when the toner in the corresponding developing device 42 is exhausted, the toner is supplied to the toner container. Note that, in the reference numerals 40 to 48 in the drawing, C for cyan, M for magenta, Y for yellow, and K for black are shown.
[0053]
FIG. 2 shows a fixing device 30 used in the color laser printer shown in FIG.
The fixing device 30 includes a fixing member 34 and a pressure member 35.
[0054]
The fixing-side member 34 is guided by three non-rotating belt guide members 50, 51, and 52 and stretches the endless fixing belt 53 in a substantially cylindrical shape, and is rotatably supported around a heat source 54 provided at the center thereof. Then, while the fixing belt 53 is heated by a heat source 54 such as a halogen heater, the fixing belt 53 contacts the pressing roller 36 of the pressing member 35 to form a fixing nip N with the pressing member 35.
[0055]
One of the three belt guide members 50, 51, and 52 also serves as a heat shielding member, and is formed by bending both side edges 50a of a long and thin plate material at right angles to the heat source 54 side, and has a substantially cylindrical shape. The heating range by the heat source 54 is limited by arranging the fixing belt 53 in the fixing belt 53 extending in the radial direction.
[0056]
Then, as shown in FIG. 3, the heat shielding member 50 as a belt guide member affixes a heat insulating member 55 such as a felt, a foamed silicon, or a Teflon film on both sides of the both side edges 50 a in the non-recording medium conveyance region, The heat insulating member 55 contacts the inner surface of the fixing belt 53. On the other hand, in the recording medium transport area, a gap is provided by the thickness t of the heat insulating member 55 and the fixing belt 53 is held in non-contact with the inner surface thereof.
[0057]
As shown in FIG. 2, a fixing fixing member 58 in a non-roller shape is attached to the heat shielding member 50, which is a belt guide member, on the side opposite to the heat source 54 with an attaching screw 57.
[0058]
The fixing / fixing member 58 includes a support member 51 that is another one of the three belt guide members 50, 51, and 52, an elastic member 61 that is fitted to and supported by the front side of the support member 51, and a support member. A reinforcement member 62 attached to the back side of the support member 51, a sheet member 63 covering the entire front side of the support member 51, a fastening screw 65 for attaching the sheet member 63 to the reinforcement member 62 via a long plate-shaped spacer 64, and the like.
[0059]
The support member 51 may be made of a metal material, but is preferably made of a heat-insulating member such as a resin material, and is formed in an elongated shape as shown in FIG. Then, similarly to the heat shielding member 50 as another belt guide member, a heat insulating member 66 such as a felt, a foamed silicon, and a Teflon film is stuck on the surface in the non-recording medium conveyance region, and the heat insulating member 66 is used. It contacts the inner surface of the fixing belt 53. On the other hand, in the recording medium transport area, a gap is provided for the thickness of the heat insulating member 66 and the fixing belt 53 is held in a non-contact manner with the inner surface thereof.
[0060]
In the recording medium transport area, an elongated rectangular recess is provided, and a heat insulating elastic member 61 is fitted therein to support the elastic member 61. The elastic member 61 may have a flat surface as shown in FIG. 5A, or may be curved and have an radius as shown in FIG. 5B.
[0061]
As can be seen from FIGS. 5A and 5B, two slit-shaped fitting grooves are provided in parallel on the back surface of the support member 51 with the protrusion 51 a into which the mounting screw 57 is screwed in. Fit both sides. The reinforcing member 62 is a stay having a U-shaped cross section, and is formed of a rigid material that is not deformed or hardly deformed by the fixing pressure.
[0062]
The sheet member 63 covering the front side of the support member 51 is a heat-resistant protective sheet containing glass fiber, has a low friction characteristic by being coated with fluorine, and covers the entire support member 51 supporting the elastic member 61. The elastic member 61 is prevented from being worn due to friction with the fixing belt 53.
[0063]
Then, the reinforcing member 62 is urged by an urging member provided on the fixing side plate (not shown), and the elastic member 61 of the fixing member 58 is pressed against the fixing belt 53 via the sheet member 63 as shown in FIG. A fixing nip N is formed between the fixing belt 53 and the pressure roller 36 by contacting the pressure roller 36 of the pressure side member 35. In the non-recording medium transport area, as shown in FIG. 6, the heat insulating member 66 is pressed against the fixing belt 53 via the sheet member 63 to contact the pressing roller 36 of the pressing member 35.
[0064]
As the last one of the three belt guide members 50, 51, and 52, a plate-shaped guide member that prevents the fixing belt 53 from deforming and coming into contact with the heat source 54 is provided.
[0065]
As shown in FIG. 7, the guide member 52 also has a felt, foamed silicon, Teflon film or the like on the surface in the non-recording medium transport region, as shown in FIG. Of the fixing belt 53 through the heat insulating member 68. On the other hand, in the transport area of the recording medium P, a gap is provided for the thickness t of the heat insulating member 68 and the fixing belt 53 is held in a non-contact manner with the inner surface thereof.
[0066]
By the way, as shown in FIG. 8, when the guide member 52 is provided with a through-hole 52a for heating the fixing belt 53 through heat from the heat source 54, the heat from the heat source 54 is transmitted to the fixing belt 53 through the through-hole 52a. It is possible to heat the fixing belt 53 effectively by applying the fixing belt 53 effectively.
[0067]
Further, when the guide member 52 is formed of a wire as shown in FIG. 9A and the heat insulating members 68 are wound around both ends thereof and arranged as shown in FIG. 9B, the heat from the heat source 54 is not interrupted by the guide member 52. Heat can be effectively applied to the fixing belt 53 to heat the fixing belt 53 effectively.
[0068]
Further, as shown in FIG. 10, when a cover member 73 is attached to a side facing the heat source 54 with a heat insulating member 72 interposed therebetween to form an air layer 74 on the heat shielding member 50, heat transfer is blocked by the air layer 74. As a result, the belt heating efficiency can be increased.
[0069]
Here, the fixing belt 53 is made of a metal material having good thermal conductivity, such as Ni, SUS, Fe, or Al, as a base material, and a fluorosilicone-based resin or rubber as its surface material. In the case of a collar, a heat-resistant layer is provided between the base material and the surface material. Then, as shown in FIG. 2, a temperature detecting member 70 such as a thermistor contacts the outer periphery of the fixing belt 53.
[0070]
On the other hand, the pressure side member 35 includes a pressure roller 36 rotatably supported at a fixed position and rotatably driven by a driving unit (not shown), a heat source 37 such as a halogen heater provided at a center position thereof, and a pressure roller 36. And a temperature detecting member 38 such as a thermistor that contacts the outer periphery. Here, the surface hardness of the fixing belt 53 is equal to or smaller than the surface hardness of the pressure roller 36.
[0071]
At the time of fixing, the heat sources 54 and 37 are turned on, the fixing belt 53 and the pressure roller 36 are directly heated by radiant heat, the temperature is detected by the temperature detecting members 70 and 38, and the heat sources 54 and 37 are turned on and off. Keep at temperature. On the other hand, the pressure roller 36 is rotated by a driving means (not shown), and the fixing belt 53 is guided by the non-rotating belt guide members 50, 51, 52 by friction and travels while slidingly contacting the heat insulating members 55, 66, 68. At the same time, the recording medium P sent between the fixing nips is conveyed.
[0072]
As a result, the fixing belt 53 heated to a predetermined temperature is uniformly pressed by the elastic member 61 and adheres to the fixing surface of the recording medium P, so that the transferred toner image is fixed on the recording medium P.
[0073]
As described above, in the recording medium transport area, the belt guide members 50, 51, and 52 are held in a non-contact manner with respect to the fixing belt 53, so that friction is reduced to improve the running stability of the fixing belt 53, and The rising time of the fixing device 30 can be shortened without the guide members 50, 51, and 52 taking heat of the fixing belt 53.
[0074]
【The invention's effect】
As described above, according to the first aspect of the present invention, since the endless fixing belt is rotatably supported by being guided by the non-rotating belt guide member, the fixing belt heated by the heat source does not touch the heat source. The fixing belt can be smoothly and stably driven, and the fixing belt can be uniformly heated to prevent the image quality from deteriorating.
[0075]
Further, since the fixing belt is directly heated by the heat source, the fixing belt having a small heat capacity can be instantaneously heated to shorten the rise time of the fixing device. Furthermore, in the recording medium transport area, the belt guide member is held in non-contact with the fixing belt, so that friction is reduced to improve the running stability of the fixing belt, and the belt guide member deprives the fixing belt of heat. Thus, the rise time of the fixing device can be shortened.
[0076]
According to the second aspect of the invention, in addition to the effects of the first aspect of the invention, since the belt guide member is a support member that supports the elastic member that comes into contact with the pressure side member via the fixing belt, the recording is performed. An elastic member is used to adhere the surface of the heating roller to the fixing surface by following irregularities on the surface of the medium and to improve the image quality by eliminating uneven gloss, and the belt guide member also serves as a support member for supporting the elastic member. As a result, the number of parts can be reduced and cost can be reduced.
[0077]
According to the invention according to claim 3, in addition to the effect of the invention according to claim 1, since the belt guide member is a guide member for preventing the fixing belt from being deformed and coming into contact with the heat source, such a belt guide member is used. A guide member is provided, and the guide member also serves as a belt guide member, thereby reducing the number of parts and reducing costs.
[0078]
According to the invention according to claim 4, in addition to the effect of the invention according to claim 3, since the guide member is provided with a through hole for heating the fixing belt through the heat from the heat source, the heat from the heat source is passed through the through hole. The fixing belt can be effectively applied to the fixing belt to effectively heat the fixing belt.
[0079]
According to the invention according to claim 5, in addition to the effect of the invention according to claim 3, since the guide member is formed of a wire, heat from a heat source is effectively applied to the fixing belt without being largely interrupted by the guide member, The fixing belt can be heated effectively.
[0080]
According to the invention according to claim 6, in addition to the effect of the invention according to claim 1, the belt guide member also functions as a heat shielding member that limits the heating range by the heat source. A heat shielding member for improving the heating efficiency is provided, and such a heat shielding member also serves as a belt guide member, thereby reducing the number of parts and reducing costs.
[0081]
According to the invention according to claim 7, in addition to the effect of the invention according to claim 6, since an air layer is formed on the heat shielding member by attaching the cover member to the side facing the heat source, heat generated by the air layer is reduced. The movement of the belt can be blocked to increase the belt heating efficiency.
[0082]
According to the invention of claim 8, in addition to the effect of the invention of claim 1, since the heat insulating member is provided at the portion of the belt guide member where the fixing belt slides, the heat of the fixing belt escapes to the belt guide member. This can increase the belt heating efficiency. be able to.
[0083]
According to the ninth aspect of the present invention, in addition to the effect of the first aspect of the present invention, since the fixing belt is stretched in a substantially cylindrical state, the running stability of the fixing belt is improved, and a heat source is provided at the center of the fixing belt. The fixing belt is deformed due to a recording medium conveyance jam or the belt being shifted, and even if the fixing belt is damaged, the possibility of the fixing belt coming into contact with a heat source is reduced, and the safety is improved. Can be uniformly heated.
[0084]
According to the tenth aspect of the present invention, in addition to the effect of the first aspect of the present invention, the fixing belt is made of a metal material having good thermal conductivity, so that the heat resistance can be improved and the possibility of ignition can be eliminated. it can.
[0085]
According to an eleventh aspect of the present invention, there is provided an image forming apparatus including the fixing device according to any one of the first to tenth aspects. Can be.
be able to.
[0086]
According to the twelfth aspect of the present invention, there is provided an image forming method for forming an image on a recording medium by fixing with the fixing device according to any one of the first to tenth aspects. The image forming method used can be provided.
[Brief description of the drawings]
FIG. 1 is an overall schematic configuration diagram of a color copying machine provided with a fixing device according to the present invention.
FIG. 2 is a schematic configuration diagram of a fixing device provided in the color copying machine.
FIG. 3 is a cross-sectional view illustrating a position of a heat shielding member in a fixing-side member of the fixing device.
FIG. 4 is a diagram illustrating a support member that holds an elastic member in the fixing-side member when viewed from the pressure-side member.
5A is a cross-sectional view of a support member to which a reinforcing member is attached, and FIG. 5B is a cross-sectional view of another example of the support member.
6 is a schematic configuration diagram of the fixing device at a position BB in FIG. 4;
FIG. 7 is a sectional view of a guide member position in the fixing side member.
FIG. 8 is a schematic configuration diagram of a fixing device using a guide member of another example.
FIG. 9A is a diagram illustrating a guide member according to still another example, and FIG. 9B is a schematic configuration diagram of a fixing device using the guide member.
FIG. 10 is a schematic configuration diagram of a fixing device using a heat shielding member of another example.
[Explanation of symbols]
30 fixing device 34 fixing side member 35 pressure side member 50 heat shielding member (belt guide member)
51 Supporting member (belt guide member)
52 Guide member (belt guide member)
52a through hole 53 fixing belt 54 heat source 55 heat insulating member 61 elastic member 66 heat insulating member 68 heat insulating member 73 cover member 74 air layer P recording medium N fixing nip

Claims (12)

The endless fixing belt is rotatably supported by being guided by a non-rotating belt guide member, and the fixing belt is heated by a heat source, while the fixing belt is brought into contact with the pressing side member to form a fixing nip between the pressing side member and the fixing side. In the fixing device to be formed,
The fixing device, wherein the belt guide member is held in non-contact with the fixing belt in a recording medium conveyance area. The fixing device according to claim 1, wherein the belt guide member is a support member that supports an elastic member that contacts the pressure-side member via the fixing belt. The fixing device according to claim 1, wherein the belt guide member is a guide member that prevents the fixing belt from being deformed and coming into contact with the heat source. The fixing device according to claim 3, wherein the guide member is provided with a through hole that heats the fixing belt by passing heat from the heat source. The fixing device according to claim 3, wherein the guide member is formed of a wire. The fixing device according to claim 1, wherein the belt guide member also functions as a heat shielding member that limits a heating range of the heat source. The fixing device according to claim 6, wherein a cover member is attached to a side facing the heat source to form an air layer on the heat shielding member. The fixing device according to claim 1, wherein a heat insulating member is provided at a portion where the belt guide member and the fixing belt are in sliding contact with each other. 2. The fixing device according to claim 1, wherein the fixing belt is stretched in a substantially cylindrical state, and the heat source is provided at a center position of the fixing belt. The fixing device according to claim 1, wherein the fixing belt is made of a metal material having good thermal conductivity. An image forming apparatus comprising the fixing device according to claim 1. An image forming method, comprising forming an image on a recording medium by fixing with the fixing device according to any one of claims 1 to 10.

Images