JP2023057219A - Heating device and image forming device - Google Patents

Abstract

To suppress a film from being holed.SOLUTION: Provided is a heating device 9 for heating a recording material P in a nip part N and comprising a cylindrical film 23 which is rotatable, a heating unit 50 for heating the film 23 and provided in the internal space of the film 23, a support member 21 for holding the heating unit 50, contacting the inner circumferential surface of the film 23, and guiding the rotation of the film 23, and a rotor 30 for forming a nip part N between the film 23 and itself. One of the heating unit 50 and the support member 23 includes an engagement part 51a located in a sheet passing region in the width direction of the recording material P orthogonal to a conveyance direction of the recording material P, and the other includes a part 21b to be engaged that engages with the engagement part 51a. The position of the heating unit 50 relative to the support member 21 in the conveyance direction is determined due to the engagement of the engagement part 51a with the part 21b to be engaged, and the engagement part 51a and the part 21b to be engaged are located downstream of an inlet of the nip part N and located upstream of an outlet of the nip part N in the conveyance direction.SELECTED DRAWING: Figure 2

Description

The present invention improves the glossiness of a toner image by reheating a fixed toner image on a recording material or a fixing device installed in an image forming apparatus such as a copier or printer using an electrophotographic method or an electrostatic recording method. It relates to a heating device such as a gloss imparting device that improves the The present invention also relates to an image forming apparatus including this heating device.

As a heating device mounted on an electrophotographic printer, a heater having a heating element on a substrate made of metal or the like, a flexible member that moves while being in contact with the heater, and a heater and a nip portion formed through the flexible member Japanese Patent Application Laid-Open No. 2002-100003 discloses a configuration having a pressure roller for pressing. The recording material bearing the unfixed toner image is heated while being nipped and conveyed by the nip portion of the heating device, whereby the toner image on the recording material is fixed to the recording material.

JP-A-10-275671

However, in the above configuration, when a recording material having protrusions such as staples of a stapler or unintentional adhering matter is conveyed to the heating device, holes may be formed in the flexible member such as a film. When the film is perforated, the toner image is not sufficiently heated in the perforated portion, and fixing failure may occur.

The present invention has been made in view of the above problems, and an object of the present invention is to suppress the formation of holes in a film.

In order to achieve the above object, the heating device of the present invention includes:
a rotatable tubular film;
a heating unit provided in the internal space of the film for heating the film;
a support member that holds the heating unit and contacts the inner peripheral surface of the film to guide the rotation of the film;
a rotating body forming a nip portion with the film;
with
In the heating device that heats the recording material at the nip,
One of the heating unit and the support member has an engaging portion positioned within a paper passing area in the width direction of the recording material perpendicular to the conveying direction of the recording material, and the other engages with the engaging portion. having an engaged portion,
By engaging the engaging portion with the engaged portion, the position of the heating unit with respect to the supporting member in the conveying direction is determined,
In the conveying direction, the engaging portion and the engaged portion are positioned downstream from the entrance of the nip portion and upstream from the exit of the nip portion.

According to the present invention, it is possible to suppress perforation of the film.

1 is a schematic configuration diagram of an image forming apparatus according to Embodiment 1; FIG. 2 is a cross-sectional view of a fixing device according to Example 1; FIG. 1 is a perspective view of a film unit and a heat-conducting member according to Example 1. FIG. 1 is a front view of a fixing device according to Embodiment 1; FIG. 2A and 2B are a cross-sectional view and a plan view of a heater according to Example 1; FIG. 4 is a modified example of the heat conducting member according to the first embodiment; FIG. 4 is a schematic diagram showing staples of a stapler and recording materials bound by the staples; FIG. 11 is a perspective view showing how a recording material is conveyed to a fixing device according to a conventional example; It is the figure which showed a mode that the heater which concerns on a prior art example bends in a conveyance direction. FIG. 10 is a cross-sectional view of a fixing device according to a conventional example; FIG. 5 is a cross-sectional view of a fixing device according to Example 2; FIG. 10 is a perspective view of a film unit and a heater according to Example 2; 8A and 8B are a cross-sectional view and a plan view of a heater according to Example 2; FIG. It is a modification of the heater according to the second embodiment. FIG. 10 is a cross-sectional view of a fixing device according to a modified example; 8A and 8B are a cross-sectional view and a plan view of a heater according to a modification; FIG. FIG. 10 is a cross-sectional view of a fixing device according to Example 3; FIG. 10 is a schematic diagram showing a heat conducting member according to Example 3 and a modified example; FIG. 11 is a cross-sectional view of a fixing device according to Example 4; FIG. 11 is a schematic diagram showing heaters according to Example 4 and a modified example;

BEST MODE FOR CARRYING OUT THE INVENTION A mode for carrying out the present invention will be exemplarily described in detail below based on an embodiment with reference to the drawings. However, the dimensions, materials, shapes, and relative arrangement of the components described in the examples should be appropriately changed according to the configuration of the device to which the invention is applied and various conditions. That is, it is not intended to limit the scope of the present invention to the following embodiments. Examples of image forming apparatuses to which the present invention can be applied include printers and copiers using an electrophotographic method or an electrostatic recording method. Here, a case where the present invention is applied to a laser printer will be described.

<Example 1>
(1) Image Forming Apparatus FIG. 1 is a schematic configuration diagram of an image forming apparatus 100 using an electrophotographic recording technique according to the first embodiment. First, the configuration and operation of the image forming apparatus 100 will be described.

An image forming operation in the image forming section of the image forming apparatus 100 will be described. When the image forming apparatus 100 receives a print instruction from an external device or the like, the scanner unit 3 emits a laser beam Z corresponding to image information toward the photoreceptor 1 . Photoreceptor 1 charged to a predetermined polarity by charging roller 2 is scanned by laser beam Z, and an electrostatic latent image corresponding to image information is formed on the surface of photoreceptor 1 . After that, the developing device 4 supplies toner to the photoreceptor 1, and a toner image is formed on the photoreceptor 1 according to the image information. The toner image on the photoreceptor 1 moves to a transfer position formed by the photoreceptor 1 and the transfer roller 5 as the photoreceptor 1 rotates in the direction of arrow R, and the recording material fed from the cassette 6 by the pickup roller 7. transcribed to P. A cleaner 8 cleans the surface of the photoreceptor 1 that has passed the transfer position.

The recording material P onto which the toner image has been transferred is fixed by heat and pressure in a fixing device 9 as a fixing section. After that, the recording material P is discharged to a paper discharge tray 11 by a paper discharge roller 10 .

(2) Fixing Device Next, the configuration and operation of the fixing device 9 will be described. In this embodiment, a tensionless film heating type fixing device 9 is used as an example of the heating device. In the fixing device 9 of this embodiment, an endless belt-shaped (or cylindrical) heat-resistant film is used, and at least part of the circumference of the film is always tension-free (a state in which no tension is applied). It is a device that is rotationally driven by the rotational driving force of the pressurizing member.

FIG. 2 is a schematic cross-sectional view of the fixing device 9 of this embodiment, showing how two sheets of recording material P bound with staples H for a stapler are conveyed to the fixing device 9 with the toner image T thereon. indicates 3A is an exploded perspective view of the film unit 20 used in the fixing device 9, and FIG. 3B is a perspective view of the heat conducting member 51. As shown in FIG. FIG. 4 is a front view of the fixing device 9 as seen from the recording material conveying direction.

The configuration of the fixing device 9 will be described with reference to FIG. The fixing device 9 of this embodiment has a rotatable cylindrical film 23 and a heating unit 50 that heats the film 23 in the internal space of the film 23 . The heating unit 50 is composed of a heater 22 which is a heating body, and a heat conducting member 51 which is joined to the heater 22 and contacts the inner surface of the film 23 to transfer the heat of the heater 22 to the film 23 . The fixing device 9 further includes a film guide 21 that supports the heater 22 and guides the rotation of the film 23 , a reinforcing member 24 that reinforces the film guide 21 , a heating unit 50 and the film guide 21 and the nip portion N with the film 23 interposed therebetween. and a pressure roller 30 forming a

The heater 22 has an elongated plate-shaped ceramic substrate 22a, a heating element 22b that generates heat when energized, and a protective layer 22c that protects the surface of the heating element 22b. A detailed configuration of the heater 22 will be described later.

A thermistor 25, which is a temperature detecting member, is in contact with the contact surface of the heater 22 with the film guide 21. As shown in FIG. Power supply to the heating element 22b is controlled according to the temperature detected by the thermistor 25, and the temperatures of the heater 22 and the film 23 are managed.

The film 23 is a cylindrical rotating body. The thickness of the film 23 is preferably about 20 μm or more and 100 μm or less in order to ensure good thermal conductivity. When the film 23 is a single-layer film, it is preferable to use a material such as PTFE (polytetrafluoroethylene), PFA (tetrafluoroethylene-perfluoroalkyl vinyl ether), PPS, or the like as the film base layer 23a. When a composite layer film is used, it is preferable to use materials such as PI (polyimide), PAI (polyamideimide), PEEK (polyetheretherketone), and PES (polyethersulfone) as the film base layer 23a. Furthermore, as the film release layer 23b coated on the surface thereof, it is preferable to use materials such as PTFE, PFA, and FEP (tetrafluoroethylene-perfluoroalkyl vinyl ether) to form a composite layer film. It is also preferable to use pure metals, alloys, etc. with high thermal conductivity such as SUS, Al, Ni, Cu, and Zn for the base layer, and the release layer to be coated with the above-described coating treatment and a fluororesin tube. .

In the film 23 of this embodiment, the film base layer 23a is made of PI with a thickness of 60 μm, and the film release layer 23b made of PFA is coated with a thickness of 12 μm in order to achieve both abrasion and thermal conductivity of the film release layer 23b due to the passage of paper. It is a multi-layered film. The longitudinal length of the film 23 was set to 240 mm. The axial direction of the cylindrical shape of the film 23 is hereinafter referred to as the longitudinal direction.

The film guide 21 is provided in the internal space of the film 23 and is a support member that supports the heater 22 with the heater support portion 21a. Further, the film guide 21 is provided with a concave portion 21b that engages with a convex portion 51a of a heat conducting member 51, which will be described later. The film guide 21 has the film 23 loosely fitted on the outside, and also has the function of guiding the rotation of the film 23 while slidingly contacting the inner peripheral surface of the film 23 . Since the film guide 21 is required to have heat resistance and rigidity, it is preferable to use liquid crystal polymer resin or the like, which has high heat resistance and excellent strength, as the material for the film guide 21 . As the film guide 21, for example, a molded article made of heat-resistant resin such as PPS (polyphenylene sulfite) or liquid crystal polymer is used.

The reinforcing member 24 is made of a metal such as iron, and receives the force of a pressure spring, which will be described later, to press the heater 22 toward the pressure roller 30 via the film guide 21 . Further, the reinforcing member 24 is also a member for maintaining strength so that the film guide 21 is not greatly deformed even by the pressure forming the nip portion N. As shown in FIG.

The heat-conducting member 51 is a member elongated in the longitudinal direction, and is preferably made of a material having excellent heat conductivity, such as metal. As described above, the heat conducting member 51 constitutes the heater 22 and the heating unit 50 for heating the film 23 . That is, the heating unit 50 heats the film 23 through the heat conducting member 51 by the heater 22 that has generated heat. The heat-conducting member 51 of this embodiment is bonded to the heater 22 with a heat-conducting adhesive 60 and contacts the inner peripheral surface of the film 23 .

The heat-conducting member 51 is provided so as to cover the entire width of the substrate 22a when viewed in the thickness direction of the substrate 22a. The heat-conducting member 51 has a convex portion 51a bent into an L shape at the end portion in the lateral direction. ing. The convex portion 51a engages with the concave portion 21b, so that it does not overlap with the substrate 22a or the heating element 22b when viewed in the thickness direction of the substrate 22a, and is positioned upstream of the heater 22 in the transport direction. The convex portion 51a is positioned downstream from the entrance of the nip portion N and upstream from the exit of the nip portion N in the transport direction together with the concave portion 21b. By inserting the convex portion 51 a into the concave portion 21 b provided in the film guide 21 , the heating unit 50 is restricted from moving relative to the film guide 21 in the transport direction. In this embodiment, the thickness direction of the substrate 22a is substantially parallel to the direction in which the recording material P conveyed to the fixing device 9 is pressed.

The pressure roller 30 is a rotating body having a metal core 30a made of iron, aluminum, or the like, an elastic layer 30b made of silicone rubber or the like, and a release layer 30c made of PFA or the like. The pressure roller 30 receives power from the motor M via a gear (not shown), rotates in the direction b, and forms a nip portion N with the heating unit 50 and the film guide 21 with the film 23 interposed therebetween.

As shown in FIG. 2, the rotation of the pressure roller 30 in the direction b causes the film 23 to rotate in the direction a following the movement of the pressure roller 30, and the heating unit 50 moves substantially in the direction in which the recording material P is conveyed. A parallel force in the direction of arrow c is received. However, since the convex portion 51a of the heat-conducting member 51 is engaged with the concave portion 21b of the film guide 21 as described above, the heating unit 50 cannot be greatly moved or bent in the c direction within the heater support portion 21a. no. As the recording material P is nipped and conveyed at the nip portion N, the toner image T is heated and fixed on the recording material P, and the recording material P that has passed through the nip portion N is conveyed to the discharge tray 11 .

Next, the film unit 20 of the fixing device 9 will be described with reference to the exploded perspective view of FIG. 3(a). The heater 22 and the heat-conducting member 51 joined with the heat-conducting adhesive are held by the film guide 21 as the heating unit 50 . After the film guide 21 and the reinforcing member 24 are fitted together, the film 23 is fitted around the outer periphery of the film guide 21 and the reinforcing member 24 with a margin in the peripheral length. Both ends of the reinforcing member 24 protrude from both ends of the film 23, and flanges 26 are fitted to each end. Thus, the film unit 20 including the film 23, the heating unit 50, the film guide 21, the flange 26, etc. is assembled.

A power supply terminal of the heater 22 protrudes from one end of the film 23 in the longitudinal direction, and a power supply connector 27 is fitted thereto. The power supply connector 27 contacts the electrode portion of the heater 22 with a predetermined contact pressure to form a power supply path. The heater clip 28 is a C-shaped metal plate, and retains the edge of the heater 22 against the film guide 21 by its springiness. That is, the heater 22 is held by the power supply connector 27 and the heater clip 28 as holding members at both ends in the longitudinal direction located outside the sheet passing area.

As shown in FIG. 3B, the heat conducting member 51 has a length that can cover the entire paper passing area in the width direction orthogonal to the conveying direction of the recording material. In this embodiment, the width direction of the recording material is substantially parallel to the longitudinal direction of the film 23 or the like. In addition, the convex portion 51a of this embodiment extends over the entire length of the heat conducting member 51 . The heat-conducting member 51 may be formed by bending a metal plate member, or may be manufactured by other means such as cutting.

Next, the configuration of the fixing device 9 will be described in more detail with reference to FIG. Flanges 26 provided at both ends of the film 23 regulate the longitudinal movement of the rotating film 23 and regulate the position of the film 23 during operation of the fixing device 9 .

The film unit 20 is provided to face the pressure roller 30 and is supported by the top board side housing 41 . The film unit 20 is supported by the top plate-side housing 41 so as to be freely movable in the pressing direction, and its movement in the longitudinal direction is restricted. A pressure spring 45 is attached to the top plate side housing 41 of the fixing device 9 in a compressed state. The pressing force of the pressure spring 45 is received by both longitudinal ends of the reinforcing member 24 via the flanges 26 . The reinforcing member 24 is pressed toward the pressure roller 30 by the pressing force of the pressure spring 45, and the entire film unit 20 is pressed toward the pressure roller 30 to form the nip portion N. As shown in FIG.

The bearing member 31 is provided so as to support the metal core of the pressure roller 30 , and receives the pressing force from the film unit 20 via the pressure roller 30 . In order to rotatably support the metal core of the pressure roller 30, which reaches a relatively high temperature, the bearing member 31 is made of a material having heat resistance and excellent slidability. The bearing member 31 is attached to the bottom housing 43 of the fixing device 9 .

(3) Heater 22
Next, the material, manufacturing method, and the like that constitute the heater 22 of this embodiment will be described with reference to FIG. FIG. 5(a) is a cross-sectional view of the heater 22 viewed from the longitudinal direction, and FIG. 5(b) is a plan view of the substrate 22a viewed from the thickness direction.

(3-1) Substrate 22a
The substrate 22a of this embodiment is a substrate made of ceramics. The type of ceramics is not particularly limited, and may be appropriately selected in consideration of the required mechanical strength, the coefficient of linear expansion suitable for the formation of the heating element, the availability of plate materials in the market, and the like.

The thickness of the substrate 22a may be determined in consideration of strength, heat capacity, and heat dissipation performance. If the thickness of the substrate 22a is thin, the heat capacity is small, which is advantageous for a quick start. Conversely, if the thickness of the substrate 22a is large, it is advantageous in terms of distortion during heating of the heating element, but if it is too thick, the heat capacity is large, which is disadvantageous for quick start. A preferable thickness of the substrate 22a is 0.3 mm to 2.0 mm in consideration of mass productivity, cost, and performance balance. The substrate 22a of this embodiment is an alumina substrate having a width of 10 mm, a length of 300 mm and a thickness of 1 mm.

(3-2) Heating element 22b
The heating element 22b is obtained by printing a heating element paste, which is a mixture of (A) a conductive component, (B) a glass component, and (C) an organic binder component, on the substrate 22a and then firing the paste. When the heating element paste is fired, the organic binding component (C) is burned off and the components (A) and (B) remain, forming the heating element 22b containing the conductive component and the glass component. Here, as the conductive component of (A), silver-palladium (Ag-Pd), ruthenium oxide (RuO ₂ ), etc. are used singly or in combination, and the square] sheet resistance value (surface resistivity). In addition to the above (A) to (C), other materials may be included as long as the amount is small enough not to impair the characteristics of the present invention.

The heating element 22b of this embodiment is made of a heating element paste containing silver and palladium (Ag.Pd) as a conductive component, a glass component, and an organic binding component. After the heating element paste is applied to the substrate 22a made of ceramics by screen printing, it is dried at 180° C. and fired at 850° C. to form the heating element 22b. The heating element 22b after firing has a thickness of 15 μm, a length of 220 mm, and a width of 1.1 mm.

(3-3) Feeding electrode 22d and conductive pattern 22e
The power feeding electrode 22d and the conductive pattern 22e shown in FIG. 5B are made of silver (Ag), platinum (Pt), gold (Au), silver-platinum (Ag-Pt) alloy, silver-palladium (Ag-Pd). Mainly made of alloys. The power supply electrode 22d and the conductive pattern 22e were formed by printing a paste obtained by mixing (A) a conductive component, (B) a glass component, and (C) an organic binder component on the substrate 22a in the same manner as the heating element paste, and then firing the paste. It is.

The power supply electrode 22d and the conductive pattern 22e are provided for the purpose of supplying power to the heating element 22b, and the resistance is sufficiently low with respect to the heating element 22b. For the heat generating paste, the power supply electrode, and the conductive pattern paste, it is necessary to select a material that softens and melts at a temperature lower than the melting point of the substrate 22a and has heat resistance in view of the temperature in practical use.

The power supply electrode 22d and the conductive pattern 22e of the present embodiment are formed using a paste for the power supply electrode and the conductive pattern, which contains silver as a conductive component, a glass component, and an organic binding component. After the paste for the power feeding electrode and conductive pattern was applied to the ceramic substrate 22a by screen printing, it was dried at 180° C. and fired at 850° C. to form the power feeding electrode 22d and the conductive pattern 22e.

(3-4) Protective layer 22c
The protective layer 22c shown in FIG. 5 is provided for the purpose of protecting the heating element 22b and the conductive pattern 22e. As the material, glass and PI (polyimide) are preferable from the viewpoint of heat resistance, and if necessary, a thermally conductive filler having insulating properties may be mixed.

In this embodiment, a protective layer glass paste is prepared, and after coating the protective layer glass paste on the heating element 22b and the conductive pattern 22e by screen printing, it is dried at 180° C. and fired at 850° C. to obtain a layer thickness of 60 μm. A protective layer 22c was formed.

(4) Functions and Effects In order to explain the functions and effects of the present invention, first, when a recording material bound with staples for a stapler is conveyed to a fixing device, the film, which is a flexible member, is positioned at the positions of the staples. A corresponding perforation mechanism will be described.

7A is a schematic diagram of a staple H for a stapler, and FIG. 7B is a schematic diagram showing two sheets of recording material P bound using the staple H. FIG. FIG. 8 is a schematic diagram showing how the recording material P bound by the staples H is conveyed to the fixing device 109 having the conventional film unit 120 and passed. When the recording material P is bound with the staple H using a stapler, the staple H is attached along the recording material P on one surface (surface a), and the needle H is bent on the other surface (surface b). A projecting bent portion H1 is formed. When the recording material P bound by the staples H shown in FIG. 7B is conveyed to the fixing device, holes W corresponding to the positions of the staples may be formed in the film 23, which is a flexible member, as shown in FIG. be. In particular, when the needle H in FIG. 7(b) is conveyed so that the b side, which is the bent side of the needle H, contacts the film 23, the sharp bent portion H1 of the needle H pierces the film 23, causing a hole in the film 23. Remarkable gaps occur. As a result, the toner image T on the recording material P corresponding to the hole W of the film 23 is not sufficiently heat-fixed, and an offset image U as shown in FIG. 8 is generated, resulting in poor fixation.

In the conventional fixing device 109, the mechanism by which the staple H of the stapler punches the film 23 will be described in more detail with reference to FIGS. 9 and 10. FIG. In the following, with regard to the configuration of the conventional example, the same reference numerals are given to the configurations similar to those of the first embodiment, and the description thereof will be omitted. The conventional fixing device 109 shown in FIGS. 9 and 10 is not provided with the heat conducting member 51 and the film guide 121 is not provided with a concave portion, unlike the present embodiment. Therefore, in the fixing device 109, the film 23 is in direct contact with the heater 22 and slides thereon.

FIG. 9A is a perspective view showing how the recording material P bound by the staples H is conveyed to the fixing device 109 of the conventional example, with the film 23 and pressure roller 30 removed so that the heater 22 can be seen. is. FIG. 9 shows the case where the recording material P is conveyed in the direction in which the b side, which is the side where the needle H is bent, contacts the film 23 . FIG. 9(b) shows the initial state of the fixing device 109 in which the heater 22 is attached to the heater support portion 121a of the film guide 121 in the region a of FIG. 9(a) and no load is applied. . As shown in FIG. 9B, the heater support portion 121a is provided widely with respect to the heater 22 so as to have a gap S between the heater 22 and the heater 22, considering that the heater 22 generates heat and expands. there is The heater 22 is held at both ends by the power supply connector 27 and the heater clip 28, but is not particularly held within the paper passing area through which the recording material P passes.

FIG. 9(c) shows a state in which the heater 22 in contact with the film 23 is bent in the conveying direction of the recording material P by receiving a force in the c direction from the film 23 as the film 23 rotates. At this time, a gap L is formed between the heater 22 and the heater support portion 121a on the upstream side of the heater 22 in the transport direction. Since the heater 22 is held by the power supply connector 27 and the heater clip 28 at both ends in the longitudinal direction, the gap L becomes maximum near the center of the heater 22 in the longitudinal direction.

FIG. 10A is a cross-sectional view of the central portion in the longitudinal direction of the conventional fixing device 109 in a state where the heater 22 is not bent. FIG. 10B is a cross-sectional view of the central portion in the longitudinal direction of the fixing device 109 in a state where the heater 22 is bent due to the rotation of the film 23. FIG. The heater 22 is arranged inside the heater support portion 121 a of the film guide 121 .

At the nip portion N, the needle H receives pressure from the pressure roller 30, so the needle H is pushed into the gap L. As shown in FIG. At this time, the needle H strongly rubs against the hard and sharp corner of the heater 22, and the film 23 sandwiched therebetween is perforated. It is conceivable that the needle H may be pushed into a gap between the heater 22 and the heater support portion 21a on the downstream side of the heater 22 in the conveying direction. Therefore, the film 23 is less likely to be perforated. In the paper passing evaluation described later, even with the configuration having the gap on the downstream side in the transport direction with respect to the heater 22, the film 23 was not perforated.

(4.1 Paper passing evaluation)
Next, the paper passing evaluation performed to confirm the effects of the present invention will be described. As a paper feed evaluation, as shown in FIG. 7B, two sheets of the recording material P were piled up and 20 sheets were continuously fed at a conveying speed of 200 mm/s by binding the tip at three points with a needle H. The presence or absence of perforations in the film 23 and image defects were checked. In addition to the fixing device 9 of the present embodiment, the paper feeding evaluation was performed in the same manner for the fixing device 109 having no heat-conducting member of the conventional example described above as a comparative object, and the results were compared.

As a result of evaluation using the fixing device 9 provided with the heat-conducting member 51 of this embodiment, no holes were formed in the film 23, and excellent fixed images were obtained on all evaluation papers.

As shown in FIG. 2, the projection 51a of the heat conducting member 51 is inserted into the recess 21b of the film guide 21 in this embodiment. Therefore, even if a force acts on the heating unit 50 in the c direction, the relative movement of the heating unit 50 with respect to the film guide 21 toward the downstream side in the transport direction is restricted. Therefore, according to the present invention, there is no gap between the heating unit 50 and the heater support portion 21a on the upstream side of the heating unit 50 in the conveying direction. The film 23 can be prevented from being perforated even when it is conveyed. In a state where the heating unit 50 is not loaded, the convex portion 51a may or may not be in contact with the concave portion 21b from the beginning. Any configuration that minimizes the gap with the guide 21 may be used.

As described above, the fixing device 109 of the conventional example is configured without the heat-conducting member shown in FIG. Other image forming apparatuses and fixing devices employ the same configurations as those in the first embodiment, and thus descriptions thereof are omitted.

When the conventional fixing device 109 was used and the same paper feeding test as in Example 1 was performed, holes were formed in the film 23 and an offset image U as shown in FIG. 8 was produced, resulting in an image defect. It is considered that this is because the heater 22 received a force in the c direction from the film 23 and moved in the conveying direction, as shown in FIG. 10(b). That is, the needle H receives pressure from the pressure roller 30, and as a result of the needle H being pushed into the gap L between the heater 22 and the heater support portion 121a generated on the upstream side of the heater 22 in the conveying direction, the needle H and the heater The corners of 22 were strongly rubbed against each other and the film 23 was punctured.

In order to prevent the film from being perforated as in the present embodiment, the convex portion 51a does not necessarily have to extend over the entire longitudinal direction of the heat conducting member 51 (the width direction of the recording material). As long as the convex portion 51a of the heat conducting member 51 is provided in the sheet passing area of the recording material P through which the needle H passes, the same effects as in the present embodiment can be expected. In particular, if the convex portion 51a is provided at the central portion in the longitudinal direction where the amount of deformation of the heater 22 is the largest, the relative movement of the heating unit 50 to the film guide 21 toward the downstream side in the transport direction can be effectively restricted. can be done.

As described above, the present invention is not limited to the configuration of the first embodiment. As a modification, like the heat conducting member 52 shown in FIG. A configuration in which the convex portion 52a is provided in the entire paper area may be used. As another modified example, a plurality of protrusions 53a having a short length in the longitudinal direction may be provided in the paper passing area, like the heat conducting member 53 shown in FIG. 6B. Since the heat conducting member 52 is provided with the protrusions 52a over the entire paper passing area, sufficient strength can be obtained against the force received due to the rotation of the film 23 . On the other hand, the heat conducting member 53 is inferior to the heat conducting member 52 in terms of strength because the convex portions 53a having short lengths in the longitudinal direction are provided at three locations in the paper passing area. However, from the viewpoint of minimizing the increase in heat capacity, the thermally conductive member 53 having a smaller volume than the thermally conductive member 52 is superior. That is, it is possible to appropriately select a necessary configuration in consideration of the strength required from the pressure of the fixing device, the rotation speed of the film, etc., the warm-up time required for the image forming apparatus, the manufacturing cost of the heat-conducting member, and the like.

In this embodiment, the convex portion 51a is positioned on the upstream side in the conveying direction with respect to the heater 22, but as another modification, the convex portion is positioned on the downstream side in the conveying direction, or is positioned on both the upstream and downstream sides. A configuration and the like are also conceivable. Alternatively, a configuration in which the convex portion extends toward the pressure roller rather than away from the pressure roller in the pressure direction is also possible. Furthermore, the convex portion does not necessarily extend perpendicularly to the surface of the recording material, and even if the convex portion extends at a predetermined angle with respect to the pressing direction, the heating unit may extend downstream in the conveying direction. Any configuration that restricts the movement of the . That is, as long as the heating unit and the heater holder are provided with an engaging portion and an engaged portion that restrict the relative movement of the heating unit with respect to the heater holder, the same film perforation can be formed without being limited to the convex portion or the concave portion. A preventive effect is obtained.

<Example 2>
Next, Example 2 according to the present invention will be described. The fixing device 209 of Example 2 does not have a heat-conducting member, and the substrate of the heater is provided with projections that engage with the recesses of the film guide. Hereinafter, with regard to the configuration of the second embodiment, the same reference numerals are given to the same configurations as those of the first embodiment, and the description thereof will be omitted.

FIG. 11 is a schematic cross-sectional view of the fixing device 209 of this embodiment, showing how two sheets of recording material P bound with staples H for a stapler are conveyed to the fixing device 209 with the toner image T thereon. indicates 12(a) is an exploded perspective view of a film unit 220 used in the fixing device 209, and FIG. 12(b) is a perspective view of a heater 222 having a convex portion 222f.

The fixing device 209 according to the second embodiment differs from the fixing device 9 according to the first embodiment in that it does not have a heat-conducting member and that the heater 222 has a convex portion 222f that engages with the concave portion 221b of the film guide 221. is. That is, the heating unit of this embodiment is configured by the heater 222 alone. Descriptions of other components of the image forming apparatus and the fixing device that are the same as those of the first embodiment will be omitted.

Next, the material, manufacturing method, and the like that constitute the heater 222 of this embodiment will be described with reference to FIG. 13 . FIG. 13(a) is a cross-sectional view of the heater 222 viewed from the longitudinal direction, and FIG. 13(b) is a plan view of the substrate 222a viewed from the thickness direction.

The substrate 222a of the heater 222 in this embodiment is made of metal, and may be made of at least a metal alloy as a main material. It has an elongated plate-shaped substrate 222a, a heating element 222b that generates heat when energized, an insulating layer 222g that insulates the heating element 222b from the substrate 222a, and a protective layer 222c that protects the heating element. In addition, in order to prevent warping of the substrate during manufacturing, an insulating layer 222h is also provided on the surface of the substrate 222a opposite to the surface on which the heating element 222b is provided. In this embodiment, the heating element 222b is provided on the substrate 222a via the insulating layer 222g.

The board 222a is provided with a protrusion 222f formed by bending the upstream end of the board 222a in the transport direction. The convex portion 222f is positioned upstream in the transport direction from the heating element 222b and the insulating layer 222h, and extends so as to protrude away from the pressure roller 30 from the insulating layer 222h in the thickness direction of the substrate 222a. On the other hand, the recessed portion 221b provided in the film guide 221 is recessed away from the pressure roller 30 in the thickness direction of the substrate 222a and engages with the projected portion 222f. In this embodiment, the thickness direction of the substrate 222a is substantially parallel to the pressing direction of the recording material P conveyed to the fixing device 209. FIG.

Stainless steel, nickel, copper, aluminum, and alloys containing these as main materials are preferably used as materials for the metal substrate 222a. Among these, stainless steel is strong,
Most preferable from the viewpoint of heat resistance and corrosion. The type of stainless steel is not particularly limited, and may be appropriately selected in consideration of the necessary mechanical strength, the insulating layer described later, the coefficient of linear expansion according to the formation of the heating element, the availability of plate materials in the market, etc. . For example, martensitic and ferritic chromium-based stainless steels (400 series) have relatively low coefficients of linear expansion among stainless steels and are easily formed into an insulating layer and a heating element.

The thickness of the substrate 222a may be determined in consideration of strength, heat capacity, and heat dissipation performance. If the thickness of the substrate 222a is thin, the heat capacity is small, which is advantageous for a quick start. Conversely, if the thickness of the substrate 222a is large, it is advantageous in terms of distortion during heating of the heating element 222b. A preferable thickness of the substrate 222a is about 0.3 mm to 2.0 mm in consideration of mass productivity, cost, and performance balance. The substrate 222a of this embodiment is a ferritic stainless steel substrate (SUS430: 18Cr stainless steel) with a width of 10 mm, a length of 300 mm and a thickness of 0.5 mm.

Next, the insulating layers 222g and 222h are described. Although the material of the insulating layers 222g and 222h is not particularly limited, it is necessary to select a heat-resistant material in view of the temperature in actual use. As the material, glass and PI (polyimide) are preferable from the viewpoint of heat resistance, and when glass is used, the powder material may be appropriately selected within a range that does not impair the characteristics of the present invention from the viewpoint of heat resistance. Furthermore, if necessary, a thermally conductive filler or the like having insulating properties may be mixed. The insulating layers 222g and 222h may be made of the same material or may be made of different materials. Regarding the layer thickness, the insulating layers 222g and 222h may have the same thickness, or may have different thicknesses. In general, a heater used in an image forming apparatus preferably has a dielectric strength of about 1.5 kV. should be secured according to the material. The method of forming the insulating layers 222g and 222h is not particularly limited, but as an example, they can be formed smoothly by a screen printing method or the like. When forming an insulating layer of glass or PI (polyimide) on the substrate 222a, the coefficients of linear expansion of the substrate and the material of the insulating layer should be adjusted so that the insulating layer does not crack or peel off due to the difference in coefficient of linear expansion between the materials. need to be adjusted accordingly.

In this embodiment, after applying the insulating layer glass paste to the stainless steel substrate 222a by screen printing, drying at 180° C. and baking at 850° C., the insulating layer 222g with a layer thickness of 60 μm and the insulating layer with a layer thickness of 120 μm are formed. 222h was formed. The method of forming the heating element 222b, the power supply electrode 222d, the conductive pattern 222e, and the protective layer 222c on the substrate 222a on which the insulating layers 222g and 222h are formed is the same as that of the first embodiment, so the description is omitted.

The effects of this embodiment will be described with reference to FIG. In this embodiment, the projection 222f of the heater 222 is inserted into the recess 221b of the film guide 221. As shown in FIG. Therefore, even if a force acts on the heater 222 in the c direction, the relative movement of the heater 222 to the film guide 221 toward the downstream side in the transport direction is restricted. Therefore, according to the present invention, there is no gap between the heater 222 and the heater supporting portion 221a on the upstream side of the heater 222 in the conveying direction, and the recording material having projections such as the needle H can be conveyed. Even in such a case, the film 23 can be prevented from being perforated.

Using the fixing device 209 of the present embodiment, the same paper feeding test as in the first embodiment was performed. Furthermore, since the heat-conducting member 51 is not provided in this embodiment, the warming-up time of the fixing device 209 can be improved without excessive heat capacity increase as compared with the first embodiment.

It should be noted that the present invention is not limited to the configuration described above, and as a modified example, for example, FIG.
3, the convex portion 223f may be provided in the entire paper passing area instead of the entire longitudinal direction of the heater 223, as in the heater 223 shown in FIG. As another modification, like the heater 224 shown in FIG. 14B, a configuration in which a plurality of protrusions 224f having a short length in the longitudinal direction are provided in the sheet passing area may be used. Since the heater 223 is provided with the protrusions 223f over the entire paper-passing area, sufficient strength can be obtained against the force received by the rotation of the film 23 . On the other hand, the heater 224 is inferior to the heater 223 in terms of strength because the three protrusions 224f having a short length in the longitudinal direction are provided in the paper passing area. However, the heater 224 having a smaller volume than the heater 223 is superior to the heater 223 in terms of minimizing the increase in heat capacity. That is, it is possible to appropriately select a necessary configuration in consideration of the strength required from the pressing force of the fixing device, the rotation speed of the film, etc., the warm-up time required for the image forming apparatus, the manufacturing cost of the heater, and the like.

As other modifications, the convex portion 222f of the present embodiment is configured to be positioned on the upstream side in the conveying direction of the heater 222, but a configuration in which the convex portion is positioned on the downstream side in the conveying direction, or a configuration in which the convex portion is positioned on both the upstream and downstream sides. etc. can also be considered. Alternatively, a configuration in which the convex portion extends toward the pressure roller rather than away from the pressure roller in the pressure direction is also possible. Further, the convex portion does not necessarily extend perpendicularly to the surface of the recording material, and even if the convex portion extends at a predetermined angle with respect to the pressing direction, the heater may not extend downstream in the conveying direction. Any configuration may be employed as long as movement is restricted.

Furthermore, as other modified examples, a configuration in which a metal substrate is provided with a thermally conductive member having a convex portion, a configuration in which a ceramic substrate is provided with a convex portion, and the like are conceivable. A modification in which a metal substrate 522a is provided with a heat conducting member 551 having a convex portion 551a will be described with reference to FIGS. Hereinafter, with regard to the configuration of the modified example, the same reference numerals are given to the configurations similar to those of the first embodiment, and the description thereof will be omitted.

FIG. 15 is a schematic cross-sectional view of a fixing device 509 according to a modification. The fixing device 509 has a configuration in which a heat conducting member 551 having a convex portion 551a is joined to a heater 522 as in the first embodiment. When the heater 522 is attached to the heater attaching portion 521a of the film guide 521, the convex portion 551a of the heat conducting member 551 engages with the concave portion 521b of the film guide 521, and the relative movement of the heater 522 with respect to the film guide 521 in the conveying direction is prevented. Regulated.

FIG. 16(a) is a cross-sectional view of the heater 522 viewed from the longitudinal direction, and FIG. 16(b) is a plan view of the substrate 522a viewed from the thickness direction. The substrate 522a of the heater 522 in this embodiment is made of metal, and may be made mainly of at least a metal alloy. It has an elongated plate-shaped substrate 522a, a heating element 522b that generates heat when energized, an insulating layer 522g that insulates the heating element 522b from the substrate 522a, and a protective layer 522c that protects the heating element. Also, in order to prevent warping of the substrate during manufacturing, an insulating layer 522h is provided on the surface of the substrate 522a opposite to the surface on which the heating element 522b is provided. In this embodiment, the heating element 522b is provided on the substrate 522a via the insulating layer 522g.

<Example 3>
Next, Example 3 according to the present invention will be described. In the fixing device 309 of Example 3, the film guide 321 has the convex portion 321b, and the concave portion 351a provided in the heat conducting member 351 of the heating unit 350 is engaged with the convex portion 321b. Hereinafter, with regard to the configuration of the third embodiment, the same reference numerals are given to the same configurations as in the first embodiment, and the description thereof will be omitted.

FIG. 17 is a schematic cross-sectional view of the fixing device 309 of this embodiment, showing how two sheets of recording material P bound with staples H for a stapler are conveyed to the fixing device 309 with the toner image T thereon. indicates In this embodiment, the heating unit 350 includes the heater 22 and the heat conducting member 3 having the same configuration as in the first embodiment.
51.

The heat-conducting member 351 in this embodiment has a concave portion 351a. The recessed portion 351a is located upstream of the heater 22 in the transport direction in the heating unit 350 and is recessed toward the pressure roller 30 in the thickness direction of the substrate 22a. On the other hand, the convex portion 321b provided on the film guide 321 extends toward the pressure roller 30 in the thickness direction of the substrate 22a and engages with the concave portion 351a. As shown in FIG. 18A, the heat conducting member 351 of this embodiment has recesses 351a formed over the entire longitudinal direction. In this embodiment, the thickness direction of the substrate 22a is substantially parallel to the pressing direction of the recording material P conveyed to the fixing device 309. FIG.

Due to the engagement between the concave portion 351a and the convex portion 321b, the relative movement of the heating unit 350 to the film guide 321 toward the downstream side in the transport direction is restricted even if a force acts on the heating unit 350 in the c direction. Therefore, according to the present invention, there is no gap between the heating unit 350 and the heater support portion 321a on the upstream side of the heating unit 350 in the conveying direction, and the recording material having projections such as the needles H is not formed. The film 23 can be prevented from being perforated even when it is conveyed.

Using the fixing device 309 of this embodiment, the same paper feeding test as in Example 1 was conducted. As a result, no holes were formed in the film 23, and good fixed images were obtained on all evaluation papers. Furthermore, in the present embodiment, the thermally conductive member 351 is provided with the concave portion 351a instead of the convex portion. Small heat capacity. Therefore, in this embodiment, the heat capacity of the heat-conducting member is reduced as compared with the first embodiment, so that the warming-up time of the fixing device can be improved.

In addition, the present invention is not limited to the above-described configuration. As a modification, for example, as in the heat conducting member 352 shown in FIG. A configuration in which a concave portion 352a is provided in the . As another modified example, a plurality of concave portions 353a having a short length in the longitudinal direction may be provided in the sheet passing area, like a heat conducting member 353 shown in FIG. 18(c). Since the heat conducting member 352 is provided with the concave portions 352a throughout the paper passing area, sufficient strength can be obtained against the force received due to the rotation of the film 23 . On the other hand, the heat conducting member 353 is inferior to the heat conducting member 352 in terms of strength because the concave portions 353a having a short length in the longitudinal direction are provided at three locations in the paper passing area. However, from the viewpoint of minimizing an increase in heat capacity, the thermally conductive member 353 having a smaller volume than the thermally conductive member 352 is superior. Further, when the concave portion is processed by cutting, the heat conductive member 353 having a short concave portion is superior in processing cost to the heat conductive member 351 and the heat conductive member 352 . That is, it is possible to appropriately select a necessary configuration in consideration of the strength required from the pressing force of the fixing device, the rotational speed of the film, etc., the warming-up time required for the image forming apparatus, the manufacturing cost of the heating unit, and the like.

As other modifications, various configurations are conceivable, such as a configuration in which the recesses are provided on the downstream side in the conveying direction with respect to the heater, a configuration in which the concave portions are provided on both the upstream and downstream sides, and a configuration in which the substrate is made of metal instead of ceramics. .

<Example 4>
Next, Example 4 according to the present invention will be described. The fixing device 409 of Example 4 does not have a heat-conducting member as in Example 2. FIG. In addition, in the fixing device 409 of the fourth embodiment, the film guide 421 has the convex portion 421b, and the concave portion 422d provided on the substrate 422a of the heater 422 is engaged with the convex portion 421b. Hereinafter, with regard to the configuration of the fourth embodiment, the same reference numerals are assigned to the same configurations as those of the first embodiment, and the description thereof is omitted.

FIG. 19 is a schematic cross-sectional view of the fixing device 409 of this embodiment, showing how two sheets of recording material P bound with staples H for a stapler are conveyed to the fixing device 409 with the toner image T thereon. indicates In this embodiment, the heating unit does not have a heat-conducting member and is composed only of the heater 422 .

The heater 422 in this embodiment has a metal substrate 422a, a heating element 422b, a protective layer 422c, and insulating layers 422e and 422f. Further, a concave portion 422d is formed near the end portion of the substrate 422a on the upstream side in the transport direction and upstream of the heating element 422b and the insulating layer 422f in the transport direction. The recess 422d is recessed toward the pressure roller 30 in the pressure direction (thickness direction of the substrate 422a). On the other hand, the convex portion 421b provided on the film guide 421 extends in the pressure direction and toward the pressure roller 30 and engages with the concave portion 422d. As shown in FIG. 20(a), the heater 422 of this embodiment has recesses 422d formed over the entire longitudinal direction.

Due to the engagement between the concave portion 422d and the convex portion 421b, the relative movement of the heater 422 with respect to the film guide 421 toward the downstream side in the transport direction is restricted even if a force acts on the heater 422 in the c direction. Therefore, according to the present invention, there is no gap between the heater 422 and the heater supporting portion 421a on the upstream side of the heater 422 in the conveying direction, and the recording material having projections such as the needle H can be conveyed. Even in such a case, the film 23 can be prevented from being perforated.

Using the fixing device 409 of the present embodiment, the same paper feeding test as in the first embodiment was performed. Furthermore, in this embodiment, the substrate 422a of the heater 422 is provided with recesses 422d instead of projections. . Therefore, in this embodiment, the heat capacity of the heater is reduced as compared with the second embodiment, so that the warming-up time of the fixing device can be improved.

It should be noted that the present invention is not limited to the above-described configuration, and as a modification, for example, the concave portion 423d is formed not in the entire longitudinal direction of the heater 423 as in the case of the heater 423 shown in FIG. The structure provided may be sufficient. As another modification, a configuration in which a plurality of recesses 424d having a short length in the longitudinal direction are provided in the sheet passing area, such as a heater 424 shown in FIG. 20C, may be used. Since the heater 423 is provided with the concave portion 423 d throughout the paper passing area, sufficient strength can be obtained against the force received by the rotation of the film 23 . On the other hand, the heater 424 is inferior to the heater 423 in terms of strength because the recesses 424d having a short length in the longitudinal direction are provided at three locations in the paper passing area. However, the heater 424 having a smaller volume than the heater 423 is superior to the heater 423 in terms of minimizing the increase in heat capacity. Further, when the concave portion is processed by cutting, the heater 424 having a shorter concave portion is superior to the heaters 422 and 423 in processing cost. That is, it is possible to appropriately select a necessary configuration in consideration of the strength required from the pressing force of the fixing device, the rotational speed of the film, etc., the warming-up time required for the image forming apparatus, the manufacturing cost of the heating unit, and the like.

Other modified examples include a configuration in which the recesses are provided on the downstream side in the conveying direction with respect to the heating element, a configuration in which the recesses are provided on both upstream and downstream sides, and a configuration in which the substrate is made of ceramics instead of metal. Furthermore, it is also possible to combine the above-described multiple embodiments, and various configurations are conceivable, such as a configuration in which both the heating unit and the film guide are provided with both convex portions and concave portions.

9 heating device 21 film guide (supporting member) 21b concave portion (engaged portion) 23 film 30 pressure roller (rotating body) 50 heating unit 51a convex portion (engaging part), N... nip part, P... recording material

Claims (20)

a rotatable tubular film;
a heating unit provided in the internal space of the film for heating the film;
a support member that holds the heating unit and contacts the inner peripheral surface of the film to guide the rotation of the film;
a rotating body forming a nip portion with the film;
with
In the heating device that heats the recording material at the nip,
One of the heating unit and the support member has an engaging portion positioned within a paper passing area in the width direction of the recording material perpendicular to the conveying direction of the recording material, and the other engages with the engaging portion. having an engaged portion,
By engaging the engaging portion with the engaged portion, the position of the heating unit with respect to the supporting member in the conveying direction is determined,
The heating device, wherein, in the conveying direction, the engaging portion and the engaged portion are positioned downstream from an entrance of the nip portion and upstream from an exit of the nip portion. 2. The apparatus according to claim 1, further comprising a holding member positioned outside the sheet passing area and holding both ends of the heating unit in the width direction so as to restrict relative movement of the heating unit with respect to the supporting member. The heating device according to . The engaging portion is a convex portion,
The engaged portion is a concave portion,
3. The heating device according to claim 1, wherein the convex portion protrudes in a direction orthogonal to the conveying direction so as to overlap the concave portion when viewed in the conveying direction. The heating device according to any one of claims 1 to 3, wherein the engaging portion is provided at the center in the width direction of the paper passing area. 5. The heating device according to any one of claims 1 to 4, wherein a plurality of said engaging portions are provided in said sheet passing area. 6. The heating unit according to any one of claims 1 to 5, wherein the heating unit has a heater and a heat conducting member that contacts an inner peripheral surface of the film and conducts heat from the heater to the film. The heating device according to . 6. The heat-conducting member is bonded to the heater so as to cover the entire widthwise direction of the heater when viewed in a pressurizing direction perpendicular to the conveying direction and the width direction. The heating device according to . The engaging portion is provided on the heat-conducting member,
8. The heating device according to claim 6, wherein the engaged portion is provided on the support member. The engaging portion is provided at an upstream end portion of the heat conducting member in the conveying direction, and extends in a direction orthogonal to a surface of the conveyed recording material and away from the rotating body. The heating device according to claim 8. The heat-conducting member is an elongated plate member,
10. The heating device according to claim 8, wherein the engaging portion is formed by bending the plate member. 11. The heating device according to claim 10, wherein said heater has a substrate made of metal. The engaging portion is provided on the support member,
7. The heating device according to claim 6, wherein the engaged portion is provided on the heat conducting member. the engaging portion extends in a direction perpendicular to the surface of the conveyed recording material and toward the rotating body;
13. The heating device according to claim 12, wherein the engaged portion is provided at an upstream end portion of the heat conducting member in the conveying direction. 3. The heating unit is a heater that includes a substrate, a heating element provided on the substrate, and a protective layer that covers the heating element, and that the heating element generates heat when energized. The heating device according to any one of 1 to 5. The engaging portion is provided on the heater,
15. The heating device according to claim 14, wherein the engaged portion is provided on the support member. The engaging portion is provided at an upstream end portion of the substrate in the conveying direction, and extends in a direction orthogonal to a surface of the conveyed recording material and away from the rotating body. Item 16. The heating device according to item 15. The substrate is an elongated plate member,
17. The heating device according to claim 15, wherein the engaging portion is formed by bending the plate member. The engaging portion is provided on the support member,
15. The heating device according to claim 14, wherein the engaged portion is provided on the heater. the engaging portion extends in a direction perpendicular to the surface of the conveyed recording material and toward the rotating body;
19. The heating apparatus according to claim 18, wherein the engaged portion is provided at an upstream end portion of the substrate in the transport direction. an image forming unit that forms an image on a recording material;
a fixing unit that fixes the image formed on the recording material to the recording material;
In an image forming apparatus having
An image forming apparatus, wherein the fixing section is the heating device according to any one of claims 1 to 19.

Images