Image heating apparatus and image forming apparatus
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Patents
- Current Assignee / Owner
- CANON KK
- Filing Date
- 2022-04-12
- Publication Date
- 2026-08-03
Smart Images
Figure 0007898912000002 
Figure 0007898912000003 
Figure 0007898912000004
Abstract
Description
Technical Field
[0001] The present invention relates to an image heating device such as a heating and fixing device mounted on an electrophotographic recording type image forming apparatus such as a copying machine or a printer, or a gloss imparting device that improves the glossiness of an image by reheating a fixed toner image on a recording material.
Background Art
[0002] Conventionally, as an image heating device mounted on an image forming apparatus such as a copying machine or a printer, there is a film heating type image heating device having a cylindrical fixing film, a heater that contacts the inner surface of the fixing film, and a pressure roller that forms a nip portion together with the heater through the film. In this image heating device, the heater is attached to a heater holder. On the attachment surface of the heater, a connector for supplying power to the heater, a thermistor for controlling the temperature of the heater, a thermoswitch or a temperature fuse which is a safety device may be provided, and these apply a force in a direction to separate the heater from the heater holder. In order to suppress the separation of the heater from the heater holder, there is a configuration in which an adhesive is applied to the heater holder at predetermined intervals in the longitudinal direction to adhere the heater to the heater holder (Patent Document 1).
Prior Art Documents
Patent Documents
[0003]
Patent Document 1
Summary of the Invention
Problems to be Solved by the Invention
[0004] However, during the thermal expansion caused by the heating of the heater and the subsequent thermal contraction after heating, shear force is generated in the adhesive between the heater and the heater holder. Furthermore, in image forming machines with a long lifespan, the adhesive strength deteriorates with age. As a result, there is a risk that the heater may detach from the heater holder. Patent Document 1 attempts to strengthen the adhesive strength by providing grooves in the adhesive part of the heater holder to increase the adhesive area. However, in order to meet the demands of modern image forming machines for higher print speeds and longer lifespans, further strengthening of the adhesive strength is necessary. In other words, if the operating temperature of the heater is set higher or the pressure applied to the nip is set higher to increase the print speed, the risk of heater detachment increases due to the aforementioned increase in shear force and deterioration of adhesive strength. If heater detachment occurs, in machines that separate the heating element including the fixing film and heater from the pressure roller when the power is turned off or when the recording material jams, it may lead to problems such as the heater position shifting from its predetermined position on the heater holder.
[0005] The object of the present invention is to provide a technology that can increase the adhesive strength between the heater and the heater holder and prevent the heater from peeling off. [Means for solving the problem]
[0006] To achieve the above objective, the image heating apparatus of the present invention is A cylindrical film and A heater is placed in the internal space of the film, A roller that contacts the outer surface of the film and forms a nip between itself and the film together with the heater, Heat-resistant silicone rubber A holder that supports the heater and has an adhesive portion to which the heater is bonded with an adhesive, Equipped with, In an image heating device that heats an image formed on a recording material that is gripped and conveyed by the nip by the rotation of the roller using the heat of the heater, The surface of the adhesive portion is oriented in the direction of transport of the recording material and in the longitudinal direction of the heater which is perpendicular to the transport direction. dent It has an uneven shape with repeating convex and concave sections. The aforementioned uneven shape is formed by arranging a plurality of hole-like recesses so that they are aligned in the transport direction and the longitudinal direction, Multiple of the aforementioned recesses are separated from adjacent recesses by side walls. Each of the aforementioned recesses is depth but 50μm to 300μm Furthermore, the aperture size is 200 μm to 1000 μm, and it narrows as it gets deeper. It is characterized by the following. To achieve the above objective, the image forming apparatus of the present invention is An image forming unit that forms an image on the recording material, A fixing unit that fixes the image formed on the recording material to the recording material, In an image forming apparatus having, The fixing unit is characterized by being the image heating device of the present invention. [Effects of the Invention]
[0007] According to the present invention, it is possible to increase the adhesive strength between the heater and the heater holder and prevent the heater from peeling off. [Brief explanation of the drawing]
[0008] [Figure 1] Cross-sectional view of an image forming apparatus according to Embodiment 1 of the present invention. [Figure 2] Cross-sectional view of an image heating device according to Embodiment 1 of the present invention. [Figure 3] Figure of the heater and heater holder according to Embodiment 1 of the present invention. [Figure 4] Diagram of the heater bonding portion in Embodiment 1 of the present invention. [Figure 5] Explanatory diagram of Embodiment 1 of the present invention [Figure 6] Explanatory diagram of Embodiment 1 of the present invention [Figure 7] Diagram illustrating the comparative example. [Figure 8] A diagram illustrating the effect of Example 1 of the present invention. [Figure 9] Other Application Modes of Example 1 of the Invention [Figure 10] Diagram of the heater bonding portion in Embodiment 2 of the present invention. [Figure 11] Other Application Forms of Example 2 of the Invention
Best Mode for Carrying Out the Invention
[0009] Hereinafter, with reference to the drawings, embodiments for carrying out the present invention will be described in detail by way of example based on examples. Note that dimensions, materials, shapes, relative arrangements, etc. of the components described in this embodiment should be appropriately changed according to the configuration of the apparatus to which the invention is applied and various conditions. That is, the scope of the present invention is not intended to be limited to the following embodiments.
[0010] (Example 1) (1) Image forming apparatus 100 FIG. 1 is a schematic cross-sectional view showing a schematic configuration of an image forming apparatus 100 using an electrophotographic recording technique in Example 1 of the present invention. The image forming apparatus 1 shown in FIG. 1 is a laser printer that forms an image on a recording material P using an electrophotographic method.
[0011] When the image forming apparatus 100 receives a print signal, the scanner unit 21 emits a laser beam modulated according to the image information, and scans the surface of a photosensitive drum (electrophotographic photoreceptor) 19 charged to a predetermined polarity by a charging roller 16. The scanner unit 21 includes a light source 22, a polygon mirror 23, and a reflection mirror 24. The laser beam emitted from the light source 22 is irradiated onto the photosensitive drum 19 through the polygon mirror 23 and the reflection mirror 24, and an electrostatic latent image is formed on the photosensitive drum 19 as an image carrier. By supplying toner charged to a predetermined polarity from a developing roller 17 to this electrostatic latent image, the electrostatic latent image on the photosensitive drum 19 is developed as a toner image (developer image) corresponding to the image information. On the other hand, a recording material (recording paper) P loaded in a paper feed cassette 11 is fed sheet by sheet by a pickup roller 12, and a pair of conveyance rollers The recording material P is transported towards the register roller 14 by the register roller pair 13. Furthermore, the recording material P is transported from the register roller pair 14 to the transfer position in time with the timing when the toner image on the photosensitive drum 19 reaches the transfer position formed by the photosensitive drum 19 and the transfer roller 20 as a transfer member. As the recording material P passes through the transfer position, the toner image on the photosensitive drum 19 is transferred to the recording material P. The apparatus configuration that handles the process of forming the unfixed toner image on the recording material P corresponds to the image forming unit of the present invention.
[0012] Subsequently, the recording material P is heated using the heat from a heater in the fixing device (image heating device) 200, which serves as the fixing unit (image heating unit), and the toner image is heated and fixed to the recording material P. The recording material P, which carries the fixed toner image, is discharged to a tray on top of the image forming apparatus 100 by the transport roller pairs 26 and 27.
[0013] The photoreceptor 19 is cleaned by the cleaner 18 to remove any remaining toner from its surface. The motor 30 drives the fuser unit 200, etc. Power is supplied to the fuser unit 200 from the control circuit 400, which acts as a power supply control unit connected to the commercial AC power supply 401.
[0014] In this embodiment, a developing unit including a photosensitive drum 19, a charging roller 16, and a developing roller 17, and a cleaning unit including a drum cleaner 18 are configured to be detachably attached to the main body of the image forming apparatus 100 as a process cartridge 15.
[0015] Furthermore, while the above-described image forming apparatus uses a monochrome laser printer with a single-color monochrome toner as a representative example, it is not limited to this. For example, it can also be applied to color laser printers such as tandem printers that transfer two or more color toners onto a recording material via an intermediate transfer belt to form an image.
[0016] (2) Fixing device 200 Figure 2 is a schematic cross-sectional view showing the general configuration of the fixing device 200 of Example 1. The fixing device 200 includes a cylindrical film 202 as a heating rotating body, a heater 300 that contacts the inner surface of the film 202, a pressure roller 208 as a pressing rotating body that contacts the outer surface of the film 202 and forms a fixing nip portion N between itself and the film 202 together with the heater 300, and a metal stay 204. The heater 300 is disposed on the inside of the fixing film 202 (the internal space of the fixing film 202, which is the region facing the inner circumferential surface of the fixing film 202), and the pressure roller 208 is disposed on the outside of the fixing film 202 (the region facing the outer circumferential surface of the fixing film 202), thereby forming a fixing nip portion N between the fixing film 202 and the pressure roller 208.
[0017] The film 202 is a multilayer heat-resistant film formed in a tubular shape. The base layer of the film 202 is made of a heat-resistant resin such as polyimide, or a metal such as stainless steel. In addition, the surface of the film 202 is coated with a heat-resistant resin with excellent release properties, such as fluororesin, to form a release layer in order to prevent toner adhesion and ensure separation from the recording material P. Furthermore, to improve image quality, a heat-resistant rubber such as silicone rubber may be formed as an elastic layer between the base layer and the release layer. The pressure roller 208 has a core metal 209 made of a material such as iron or aluminum, and an elastic layer 210 made of a material such as silicone rubber, and a release layer formed from a fluororesin tube or coating may be provided on top of it. The heater 300 is held in a heater holder 201, which is a heater holding member made of a heat-resistant resin such as liquid crystal polymer, and heats the film 202 by heating the inside of the fixing nip section N. The heater holder 201 has a concave heater housing portion 201c for holding the heater 21, which is provided on the side facing the inner surface of the film 202 and extends in the longitudinal direction of the film 202. Furthermore, the heater holder 201 has convex film guide curved surfaces on both sides of the heater housing portion 201c in the direction of recording material P transport (the rotation direction of the film 202) to guide the inner surface of the film 202. That is, the heater... The film holder 201 also has a guide function to guide the rotation of the film 202. The heater 300 has a contact (not shown) on the side opposite to the side that forms the fixing nip portion N, which contacts a power supply connector (not shown) of the heater holder 201, and is configured to receive power from this contact. The metal stay 204 receives pressure from a spring (not shown) and presses the heater holder 201 toward the pressure roller 208. The metal stay 204 also serves to reinforce the heater holder 201 and the heater 300.
[0018] The pressure roller 208 rotates in the direction of the arrow, receiving driving force from the motor 30 shown in Figure 1. As the pressure roller 208 rotates, the film 202 rotates in its path. The recording material P, which carries the unfixed toner image, is heated and fixed while being held and transported in the fixing nip section N.
[0019] (3) Heater 300 and heater holder 201 Figure 3 is a schematic diagram of the heater holder 201 and heater 300. For illustrative purposes, the heater 300 is shown detached from the heater holder 201. Both diagrams are viewed from the fixing nip N side of Figure 2.
[0020] The heater 300 comprises a ceramic substrate 305, a heating element 301, a conductor 302, and an electrode 303. The heating element 301 is mounted on the substrate 305 and generates heat when power is supplied to it. The electrode 303 connects the conductor 302 to a power supply connector (not shown) provided on the heater holder 201, thereby supplying power to the heating element 301. The substrate 305 is also provided with a glass surface protection layer 304 to protect the heating element 301 and the conductor 302.
[0021] As described above, the heating element 301 and the conductor 302 are mounted on the side of the heater 300 facing the inner surface of the film 202, which is the sliding side (first surface), and are covered with a surface protective layer 304. On the back surface of the heater 300, which is the side opposite to the side facing the inner surface of the film 202 (second surface), there is a contact (not shown) that contacts a power supply connector (not shown) provided on the heater holder 201, and the contact is covered with an insulating protective layer such as glass so that it is exposed. Through this contact, the electrode 303 is connected to the power supply connector of the heater holder 201.
[0022] Multiple heater adhesive sections 201a, indicated by the shaded areas, are provided on the bottom surface 201d of the heater housing section 201c of the heater holder 201, extending along the longitudinal direction of the heater. The area of one adhesive section 201a is 20-50 mm². 2 The degree of the shape is desirable, and it is a circle, ellipse, or polygon or quadrilateral of the same size with a diameter of about 6 mm. For example, two adjacent heater bonding parts 201a may be spaced apart in the longitudinal direction of the heater or may be connected. In this embodiment, the area of one heater bonding part 201a is 30 mm². 2 The configuration was designed to achieve this. The area of the heater bonding portion 201a is adjusted as appropriate according to the width of the heater 300 and heater holder 201, and is not limited to the above range. In this embodiment, a configuration in which multiple heater bonding portions 201a are arranged in a single row along the longitudinal direction of the heater 300 is shown, but a configuration in which multiple rows are arranged is also possible.
[0023] Here, the longitudinal direction of the heater 300 (substrate 305) coincides with the longitudinal direction of the film 202 (direction along the central axis of the cylindrical shape), the longitudinal direction of the pressure roller 208 (direction along the rotation axis), and the width direction of the recording material that is perpendicular to the direction of transport of the recording material P.
[0024] Adhesive is applied to multiple heater bonding portions 201a of the heater housing portion 201c of the heater holder 201, and the heater 300 is placed in the heater housing portion 201c so that the back surface of the heater 300 is pressed against the bottom surface 201d of the heater housing portion 201c. As a result, the back surface of the heater 300 and the bottom surface 201d of the heater housing portion 201c are bonded together via the adhesive, and the heater 300 is then placed in the heater housing portion 201c. It is fixedly supported by the heater holder 201. It is preferable to use a heat-resistant silicone rubber-based adhesive as the adhesive to be applied. The optimal amount of adhesive per heater bonding area 201a is approximately 10-20 mg, but it is not limited to this amount. In this example, 13 mg of adhesive was applied per heater bonding area 201a.
[0025] Furthermore, the bottom surface 201d of the heater housing portion 201c of the heater holder 201 is provided with a plurality of holes 201b. The holes 201b are for positioning a thermistor (not shown) that contacts the back side of the heater 300 to detect the heater temperature. Details of the heater holder 201, heater 300, and thermistor will be described later.
[0026] (4) Heater adhesive part 201a The details of the heater adhesive portion 201a in this embodiment will be explained using Figure 4. Figure 4(a) is a perspective view of the heater adhesive portion 201a. Figure 4(b) is a plan view of the heater adhesive portion 201a as seen in the direction opposite to the heater 300. Figure 4(c) is a schematic cross-section showing the cross-sectional configuration of the heater adhesive portion 201a cut in the recording material transport direction along the dotted line AA shown in Figure 4(b). Figure 4(d) is a schematic cross-section showing the cross-sectional configuration of the heater adhesive portion 201a cut in the longitudinal direction of the heater along the dotted line BB shown in Figure 4(b). Figure 4(e) is a schematic perspective view showing the three-dimensional shape of one of the multiple recesses 201e constituting the heater adhesive portion 201a.
[0027] A characteristic of the surface properties of the heater adhesive portion 201a in this embodiment is that it has irregularities in both the recording material transport direction and the heater longitudinal direction. Furthermore, each hole-like recess 201e is separated from adjacent recesses 201e. In other words, when looking at a single recess 201e, that single recess 201e is separated from the surrounding adjacent recesses 201e and is characterized by being independent of them. When these single recesses 201e are arranged vertically and horizontally at the same size, the surface shape of the heater adhesive portion 201a becomes an irregular shape with recesses 201e arranged independently, as shown in Figure 4(a).
[0028] As shown in Figure 4(e), the recess 201e has the shape of an inverted square pyramid with a base of 500 μm and a depth of approximately 150 μm, that is, the opening is a rectangle with sides of 500 μm, and the hole becomes narrower as it goes deeper. The optimal size for one of these square pyramids is a depth of 50 μm to 300 μm and a base of approximately 200 μm to 1000 μm. This is to ensure that the adhesive applied to the surface of the heater bonding portion 201a penetrates the recess appropriately.
[0029] In this embodiment, the concave and concave shapes were typically formed using a concave shape resembling an inverted square pyramid, but the concave shapes that can similarly achieve the effects described later are not limited to this. Examples of applications of this embodiment will be described later.
[0030] (5) Effects of the invention The following explains, step by step, why the shape of the heater adhesive portion 201a in this embodiment is effective in preventing heater detachment. First, we will explain the factors that make heater detachment likely to occur.
[0031] <Regarding the causes of heater detachment> Figure 5(a) is a schematic cross-section of the heater holder 201 in the recording material transport direction, cut along the dotted line C in Figure 3. Figure 5(a) shows the heater 300, heater adhesive 400, heater adhesive portion 201a of the heater holder 201, film 202, and pressure roller 208. Furthermore, in order to explain the factors causing heater peeling, the surface shape of the adhesive portion 201a is simply shown as a flat surface without irregularities in Figures 5(a) to 5(c).
[0032] The forces acting in the recording material transport direction will be explained using Figure 5(a). When the fixing device 200 is in operation, the film 202 rotates in the direction of arrow F due to the frictional force from the pressure roller 208. Similarly, it rotates in the direction of the arrow even when the recording material is being fed. At this time, the heater 300 receives a force in the direction of arrow H due to the frictional force with the rotating film 202. When the heater 300 receives a force in the direction of arrow H, a force S in the same direction also acts on the adhesive 400 between the heater 300 and the heater holder 201. In addition, as the heater 300 heats up to a high temperature and expands, forces in the directions shown by the dotted lines in the figure (arrows Bj, Bk) are applied to both the upstream and downstream sides of the heater 300 in the transport direction. These forces return to a state of relief when the fixing device 200 is stopped and the power to the heater 300 is turned off. In other words, as the fixing device 200 repeatedly operates and stops, the adhesive 400 of the heater bonding section 201a is constantly subjected to repeated stress in the direction of expansion and contraction (dotted arrows Gj, Gk).
[0033] Figure 5(b) is a schematic cross-section of the heater holder 201 along the dotted line D in Figure 3, in the longitudinal direction of the heater. Figure 5(c) is an enlarged view of the area enclosed by the dotted line in Figure 5(b). Here, in addition to the heater 300, film 202, and pressure roller 208, a thermistor 250 that contacts the back surface of the heater 300 and detects the temperature of the heater 300 is also shown. The forces acting in the longitudinal direction of the heater will be explained using Figure 5(b). Similarly, in the longitudinal direction of the heater, when the heater 300 heats up to a high temperature, it expands in the longitudinal direction (arrows Bl, Br). Here too, the adhesive 400 is subjected to repeated stress due to expansion and contraction as the fixing device 200 repeatedly operates and stops (dotted arrows G1~4).
[0034] As shown in Figure 5(c), if the repeated stress due to the expansion and contraction described above continues to be applied over a long period of use, a portion of the heater adhesive portion 201a may partially peel off from the adhesive 400. This phenomenon can occur in both the recording material transport direction shown in Figure 5(a) and the longitudinal direction of the heater shown in Figure 5(b).
[0035] Furthermore, the peeling of the adhesive 400 may be exacerbated by the following effects. The heating element (film unit), including the film 202, heater holder 201, and heater 300, is biased against the pressure roller 208 with a predetermined pressure by a spring (not shown) when the device is powered on or in operation, thereby forming a fixing nip N. On the other hand, when the power is turned off or when a paper jam occurs as the recording material P passes through the fixing nip N, the above pressure is released, and the heating element (film unit) may be held in a separated state from the pressure roller 208. That is, the heater 300 and the pressure roller 208 form a fixing nip. The system is configured to allow relative movement that reduces or releases the pressure force forming part N.
[0036] Figure 6(a) is a schematic cross-sectional view showing the state in which the fixing device 200 is held in a separated state. Figure 6(b) is a schematic cross-sectional view showing the state in the separated state near the heater adhesive portion 201a as seen from the longitudinal direction of the heater as shown in Figure 5(b). When in the separated state as shown in Figures 6(a) and 6(b), the pressing force that forms the fixing nip portion N is not applied to the pressure roller 208, so the heater 300 does not receive a reaction force equivalent to the applied pressure from the pressure roller 208. Generally, temperature sensing elements such as thermistors 250 and safety elements such as thermo switches are biased against the back surface of the heater 300 with a predetermined pressure. This is to detect the temperature of the heater 300 more accurately. As shown in Figure 6(b), the biasing force Fth of the thermistor 250 is applied to the back surface of the heater 300, so a force is applied that tries to peel the heater 300 away from the heater holder 201. As a result, as shown in Figure 6(c), if the adhesive 400 is partially peeling off at the edge of the bonded portion 201a, a force acts to further peel off the adhesive 400.
[0037] To summarize the forces acting on the adhesive portion 201a, first, there is the repeated stress due to the thermal expansion and contraction of the heater as explained in Figure 5, which acts on the adhesive portion 201a. In addition, there is the heating element (Phi) as explained in Figure 6. When the luminous unit separates, the biasing force on the back surface of the heater 300, such as that from the thermistor 250, acts in a direction that tries to peel off the heater 300. The interplay of these two forces leads to the heater detaching.
[0038] Using Figure 7, we will explain how heater delamination progresses in the heater adhesive section 201ax of the comparative example, which has a smooth surface without irregularities. When minute heater delamination occurs from the edge of the adhesive section due to repeated stress caused by thermal shrinkage, etc., the adhesive 400, which is mainly composed of silicone rubber, is elastic, so the delaminated portion pulls on the nearby rubber portion with elastic force (indicated by the arrow). When such a tensile force acts, the delaminated portion of the heater pulls on the adhesive section, gradually expanding the delamination, and eventually the heater delamination progresses in a chain reaction. As another comparative example of the heater adhesive section, even in a configuration in which grooves are provided on the adhesive surface in either the longitudinal direction of the heater or the direction of transporting the recording material, delamination will eventually progress in the direction along the groove due to such a chain reaction of peeling forces acting on it.
[0039] <Effects of this embodiment> The effects of this embodiment will now be explained. In this embodiment, the surface of the heater adhesive portion 201a is provided with irregularities in both the recording material transport direction and the heater longitudinal direction. In addition, each recess 201e is separated independently from adjacent recesses 201e. This embodiment has three advantages, which will be explained below. (i) It is possible to increase the surface area of the adhesive surface compared to a flat heater adhesive portion or a heater adhesive portion with grooves in one direction, as in the comparative example, and improve the adhesive strength due to the increased surface area. Furthermore, (ii) as the adhesive 400 penetrates into the recesses 201e with increased surface area, it creates an anchoring effect of the adhesive 400 to the heater adhesive portion 201a, thereby increasing the adhesive strength. Also, (iii) as shown in Figure 8, because each recess 201e is separated independently, even if partial peeling occurs as shown in Figure 7, the force that tries to elastically pull the adhesive portion can be interrupted, and it is possible to prevent the chain reaction of adhesive peeling from progressing. This effect, achieved by creating irregularities in both the longitudinal direction of the heater and the direction of recording material transport, enhances adhesion in both directions and prevents the progression of chain-like delamination.
[0040] Table 1 below compares the difference in heater adhesion strength at one heater bonding point between the configurations of the comparative example and Example 1. Furthermore, the number of A4 sheets of paper processed before heater detachment occurred was also compared during life-sustaining testing using an image forming apparatus with a process speed of 210 mm / sec and A4 portrait feed at 40 PPM.
[0041] (Table 1. Comparison of Comparative Example and Example 1) TIFF0007898912000001.tif37170
[0042] (6) Other applications of this embodiment The surface shape of the heater bonding portion that can obtain the same effect as in this embodiment is not limited to the form described in Figure 4. Applied forms of the recess 201e of Example 1 are shown in Figures 9(a1) to 9(c3).
[0043] Figure 9(a1) is a plan view of the heater bonding section 201a, which is composed of recesses 201e2 in Application Example 1 and 201e3 in Application Example 2, as seen in the direction opposite to the heater 300. Figure 9(a2) Figure 9(a3) is a schematic perspective view showing the three-dimensional shape of one of the recesses 201e2 of the multiple application examples 1 that constitute the heater adhesive portion 201a. Figure 9(a1) to Figure 9(a3) is a schematic perspective view showing the three-dimensional shape of one of the recesses 201e3 of the multiple application examples 2 that constitute the heater adhesive portion 201a. As shown in Figures 9(a1) to 9(a3), the three-dimensional object forming one of the multiple recesses that constitute the heater adhesive portion 201a may be a rectangular prism or a trapezoidal three-dimensional object.
[0044] Figure 9(b1) is a plan view of the heater adhesive portion 201a, which is composed of the recesses 201e4 of Application Example 3, as seen in the direction opposite to the heater 300. Figure 9(b2) is a schematic perspective view showing the three-dimensional shape of one of the multiple recesses 201e4 of Application Example 3 that constitute the heater adhesive portion 201a. As shown in Figures 9(b1) and 9(b2), one of the multiple recesses that constitute the heater adhesive portion 201a may be formed as a triangular pyramid, and the arrangement of these recesses may create an uneven surface.
[0045] Figure 9(c1) is a plan view of the heater adhesive portion 201a, which is composed of recesses 201e5 from application example 4 and recesses 201e6 from application example 5, as seen in the direction opposite to the heater 300. Figure 9(c2) is a schematic perspective view showing the three-dimensional shape of one of the multiple recesses 201e5 from application example 4 that constitute the heater adhesive portion 201a. Figure 9(c3) is a schematic perspective view showing the three-dimensional shape of one of the multiple recesses 201e6 from application example 5 that constitute the heater adhesive portion 201a. As shown in Figures 9(c1) to 9(c3), there is no problem even if one of the multiple recesses that constitute the heater adhesive portion 201a is formed as a cone or a cylinder.
[0046] In all of the above application examples, the same effect can be obtained if the adjacent recesses are independently separated. Furthermore, the recesses 201e in the above embodiment and the recesses 201e2 to 201e6 in application examples 1 to 5 may be arbitrarily combined to form the adhesive surface of a single heater adhesive portion 201a.
[0047] (Example 2) Embodiment 2 of the present invention will now be described. Here, only the differences between Embodiment 2 and Embodiment 1 will be described. The configuration of Embodiment 2 is the same as that of Embodiment 1 unless otherwise specifically described.
[0048] Figure 10(a) is a perspective view of the heater adhesive portion 201a2. Figure 10(b) is a plan view of the heater adhesive portion 201a2 as seen in the direction opposite to the heater 300. Figure 10(c) is a schematic cross-section showing the cross-sectional configuration of the heater adhesive portion 201a2 cut in the recording material transport direction along the dotted line AA shown in Figure 10(b). Figure 10(d) is a schematic cross-section showing the cross-sectional configuration of the heater adhesive portion 201a2 cut in the longitudinal direction of the heater along the dotted line BB shown in Figure 10(b). Figure 10(e) is a schematic perspective view showing the three-dimensional shape of one of the multiple protrusions 201f constituting the heater adhesive portion 201a2.
[0049] In Example 1, the surface of the heater adhesive portion 201a was made uneven by arranging hole-shaped recesses 201e. In contrast, in Example 2, as shown in Figure 10(a), the surface of the heater adhesive portion 201a2 was made uneven by arranging multiple protruding mountain-shaped protrusions 201f.
[0050] In Example 1, the uneven shape formed by the recesses 201e is such that each recess 201e is surrounded by a wall and is independent of the others. In contrast, in Example 2, the uneven shape formed by the protrusions 201f is such that the concave portion formed between adjacent protrusions 201f connects to the concave portion formed between other adjacent protrusions 201f. Also, as shown in Figures 4(a) and 10(a), the uneven shape of the heater adhesive portion is the heater housing portion 201 of the heater holder 201 It is formed in a recessed area that is further recessed from the bottom surface 201d of c, and its outer circumference is surrounded by a groove-like portion. In the case of the uneven shape formed by the convex portion 201f of Embodiment 2, the recessed portion between adjacent convex portions 201f is open to the groove-like portion on the side.
[0051] As shown in Figure 10(e), the heater bonding portion 201a2 in this embodiment has convex portions 201f in the shape of a square pyramid, with sides of 500 μm and a height of 200 μm, arranged in the longitudinal direction and the recording material transport direction.
[0052] In the hole-shaped recess 201e formed in Example 1, the adhesive interposed between the heater 200 and the heater adhesive portion 201a may have difficulty reaching the bottom of the recess 201e. This is likely to occur when the surface tension of the adhesive used is high or when the wettability of the adhesive surface is low.
[0053] On the other hand, as in Example 2, when multiple protrusions 201f create an uneven surface, the interposed adhesive can easily spread both vertically and horizontally, ensuring that the adhesive reaches the entire area sufficiently. In Example 2 as well, in the cross-sections shown in Figures 10(c) and (d), the peaks of the mountain-shaped protrusions 201f are connected to form an uneven surface. Therefore, similar to Figure 8 in Example 1, even if partial delamination occurs in a part of the adhesive area, it is possible to prevent the delamination from progressing in a chain reaction. In the cross-section cut at ZZ in Figure 10(b), the valleys are continuously connected, but because they are sandwiched between the connected uneven surfaces XX and YY, the delamination does not progress in a chain reaction at the ZZ valley. Similar to Example 1, when the adhesive strength and durability by paper feeding were checked, the adhesive strength was 24N, and the same effect as in Example 1 was obtained. Furthermore, even after endurance testing of 300K sheets of paper feeding, the adhesive area did not peel off, and sufficient adhesive strength can be ensured for a long period of use.
[0054] <Other usage examples of Example 2> Figures 11(a1) to 11(c4) show examples of applications of the protrusion 201f of Example 2. Similar to Example 1, the three-dimensional object that forms the mountain-shaped protrusion constituting the heater adhesive portion 201a2 of Example 2 is not limited to a square pyramid.
[0055] Figure 11(a1) is a plan view of the heater adhesive portion 201a2, which is composed of the protrusion 201f2 of Application Example 1 and the protrusion 201f3 of Application Example 2, as seen in the direction opposite to the heater 300. Figure 11(a2) is a schematic perspective view showing the three-dimensional shape of one of the multiple protrusions 201f2 of Application Example 1 that constitute the heater adhesive portion 201a2. Figure 11(a3) is a schematic perspective view showing the three-dimensional shape of one of the multiple protrusions 201f3 of Application Example 2 that constitute the heater adhesive portion 201a. As shown in Figures 11(a1) to 11(a3), the solid that forms one of the multiple protrusions that constitute the heater adhesive portion 201a2 may be a trapezoidal solid or a rectangular parallelepiped. Figure 11(b1) is a plan view of the heater adhesive portion 201a2, which is composed of the protrusions 201f4 of Application Example 3, as seen in the direction opposite to the heater 300. Figure 11(b2) is a schematic perspective view showing the three-dimensional shape of one of the multiple protrusions 201f4 of Application Example 3 that constitute the heater adhesive portion 201a2. As shown in Figures 11(b1) and 11(b2), one of the multiple protrusions that constitute the heater adhesive portion 201a2 may be formed as a triangular pyramid, and the arrangement of these protrusions may create an uneven surface.
[0056] Figure 11(c1) is a plan view of the heater adhesive portion 201a2, which is composed of the protrusion 201f5 of Application Example 4 and the protrusion 201f6 of Application Example 5, as seen in the direction opposite to the heater 300. Figure 11(c2) is a schematic perspective view showing the three-dimensional shape of one of the multiple protrusions 201f5 of Application Example 4 that constitute the heater adhesive portion 201a2. Figure 11(c3) is a schematic perspective view showing the three-dimensional shape of one of the multiple protrusions 201f6 of Application Example 5 that constitute the heater adhesive portion 201a2. As shown in Figures 11(c1) to 11(c3), the heater adhesive portion 2 One of the multiple protrusions that make up 01a2 may be formed as a cone or a cylinder.
[0057] The protrusions 201f in Example 2 and the protrusions 201f2 to 201f6 in Application Examples 1 to 5 may be combined in any way to form the adhesive surface of a single heater adhesive portion 201a2.
[0058] Furthermore, as shown in Figure 11(d), the protrusions may be arranged in a staggered pattern. A staggered pattern refers to a state in which, when the arrangement of the protrusions is viewed in the longitudinal direction or the paper transport direction, one row is offset (shifted) from the adjacent row. By using such an arrangement, it is possible to eliminate the areas where the aforementioned valleys connect, and adhesive peeling can be effectively prevented. This staggered pattern may also be applied to the arrangement of the recesses in Example 1.
[0059] Furthermore, the heater connection portion provided on the heater holder may be configured by combining the heater connection portion 201a of Example 1 and the heater connection portion a2 of Example 2. Additionally, one of the heater connection portions may be configured by combining the recess of Example 1 and the protrusion of Example 2. In other words, each configuration of each of the above-described embodiments can be used in any combination as much as possible, as long as no technical inconsistencies arise.
[0060] The disclosure of embodiments of the present invention includes the following configurations. (Composition 1) A cylindrical film and A heater is placed in the internal space of the film, A roller that contacts the outer surface of the film and forms a nip between itself and the film together with the heater, A holder that supports the heater and has an adhesive portion to which the heater is bonded with an adhesive, Equipped with, In an image heating device that heats an image formed on a recording material that is gripped and conveyed by the nip by the rotation of the roller using the heat of the heater, The surface of the adhesive portion has an uneven shape in which the irregularities are repeated in the direction of transport of the recording material and in the longitudinal direction of the heater which is perpendicular to the transport direction. The image heating device is characterized in that the depth of the aforementioned irregularities is 50 μm to 300 μm. (Configuration 2) The image heating apparatus according to configuration 1, characterized in that the aforementioned uneven shape is formed by arranging a plurality of recesses so that they are aligned in the transport direction and the longitudinal direction, respectively. (Composition 3) The image heating apparatus according to configuration 2, characterized in that the plurality of recesses are separated from adjacent recesses by side walls. (Composition 4) The image heating apparatus according to configuration 1, characterized in that the aforementioned uneven shape is formed by arranging a plurality of protrusions so as to be aligned in the transport direction and the longitudinal direction, respectively. (Composition 5) The image heating apparatus according to any one of configurations 1 to 4, characterized in that the rows in the transport direction in which the irregularities are repeated are arranged in a staggered pattern with the position of the irregularities offset in the transport direction relative to other rows adjacent to each other in the longitudinal direction. (Composition 6) The image heating device according to any one of configurations 1 to 4, characterized in that the longitudinal rows in which the irregularities are repeated are arranged in a staggered pattern with the position of the irregularities offset in the longitudinal direction from other rows adjacent to each other in the transport direction. (Composition 7) The image heating device according to any one of configurations 1 to 6, characterized in that the adhesive portions are arranged in a plurality in the longitudinal direction. (Composition 8) The image heating device according to any one of configurations 1 to 7, wherein the heater and the roller are configured to be able to move relative to each other to reduce or release the pressure force that forms the nip. (Composition 9) The system further includes a temperature sensing element for detecting the temperature of the heater, The image heating device according to any one of configurations 1 to 8, characterized in that the temperature sensing element is pressed against the side of the heater opposite to the side that slides with the inner surface of the film, in a direction that pulls the heater away from the holder. (Composition 10) An image forming unit that forms an image on the 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 characterized in that the fixing unit is an image heating device according to any one of the configurations of claims 1 to 9. [Explanation of symbols]
[0061] 201... Heater holder, 201a... Adhesive part, 250... Thermistor, 300... Heater, 400... Adhesive
Claims
1. A cylindrical film and A heater is placed in the internal space of the film, A roller that contacts the outer surface of the film and forms a nip between itself and the film together with the heater, A holder that supports the heater has an adhesive portion to which the heater is bonded with a heat-resistant silicone rubber adhesive, Equipped with, In an image heating device that heats an image formed on a recording material that is gripped and conveyed by the nip by the rotation of the roller using the heat of the heater, The surface of the adhesive portion has an uneven shape in which the irregularities are repeated in the direction of transport of the recording material and in the longitudinal direction of the heater which is perpendicular to the transport direction. The aforementioned uneven shape is formed by arranging a plurality of hole-like recesses so that they are aligned in the transport direction and the longitudinal direction, Multiple of the aforementioned recesses are separated from adjacent recesses by side walls. The image heating device is characterized in that each of the recesses has a depth of 50 μm to 300 μm, an opening dimension of 200 μm to 1000 μm, and becomes narrower as it deepens.
2. An image forming unit that forms an image on the 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 characterized in that the fixing unit is the image heating device described in claim 1.