Fixing apparatus and image forming apparatus

Abstract

This technology provides a simple configuration that can restrict cable access to the pressure change mechanism. [Solution] In a fixing device having a power supply connector connected to the heater so as to sandwich the heater and heater holder, and a pressure changing mechanism capable of switching the pressure applied to the fixing nip between a high-pressure pressurized state and a low-pressure release state, the heater holder has a connector cover integrally molded to house the power supply connector, and the connector cover has an extension portion that fits into the space between the power supply cable extending from the power supply connector and the movable part of the pressure changing mechanism, and overlaps the power supply cable and the movable part when viewed in a direction perpendicular to the flat surface of the heater.

Description

Technical Field

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[0001] The present invention relates to a fixing device mounted on an electrophotographic image forming apparatus.

Background Art

[0002] In an electrophotographic image forming apparatus, a fixing device (fixer) adopting an on-demand fixing method is known. Image fixing is performed on a sheet on which an unfixed image is transferred by applying pressure by a roller nip of a pair of pressure rollers provided in the fixing device and heating by a heater. The fixing device may be provided with a pressure release mechanism (pressure change mechanism) for switching the nip pressure of the pair of pressure rollers and a power supply cable for supplying power to the heater.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the fixing device described in Patent Document 1, a power supply cable is wired near the operating region of the pressure release mechanism. If the power supply cable enters the operating region of the pressure release mechanism, there is a concern about disconnection due to wire biting of the cable.

[0005] An object of the present invention is to provide a technique capable of restricting the approach of a cable to a pressure change mechanism with a simple configuration.

Means for Solving the Problems

[0006] To solve the above problems, the fixing device of the present invention includes a cylindrical fixing belt, a plate-shaped heater disposed in the internal space of the fixing belt, A heater holder is disposed within the internal space of the fixing belt and holds the heater along its longitudinal direction, A power supply connector for supplying power to the heater, comprising a power supply connector connected to the heater so as to sandwich the heater and the heater holder, A pressure roller that contacts the outer circumferential surface of the fixing belt, which together with the heater clamps the fixing belt and forms a fixing nip portion between itself and the fixing belt, The aforementioned fixing nip portion has a pressure changing mechanism that can switch between a high-pressure state and a low-pressure state. In a fixing device that transports the recording material in the fixing nip section and fixes the toner image formed on the recording material to the recording material, The heater holder has a connector cover integrally molded to house the power supply connector. The connector cover is characterized by having an extension portion that fits into the space between the power supply cable extending from the power supply connector and the movable part of the pressure changing mechanism, and which overlaps the power supply cable and the movable part when viewed in a direction perpendicular to the flat surface of the heater. Furthermore, in order to solve the above-mentioned problems, the fixing device of the present invention is A cylindrical fixing belt, A plate-shaped heater is disposed in the internal space of the fixing belt, A heater holder is disposed within the internal space of the fixing belt and holds the heater along its longitudinal direction, A power supply connector for supplying power to the heater, comprising a power supply connector connected to the heater so as to sandwich the heater and the heater holder, A pressure roller that contacts the outer circumferential surface of the fixing belt, which together with the heater clamps the fixing belt and forms a fixing nip portion between itself and the fixing belt, The aforementioned fixing nip portion has a pressure changing mechanism that can switch between a high-pressure state and a low-pressure state. In a fixing device that transports the recording material in the fixing nip section and fixes the toner image formed on the recording material to the recording material, The heater holder has a connector cover integrally molded to house the power supply connector. The connector cover has a retaining shape for holding the power supply cable extending from the power supply connector, The holding shape is characterized by holding the power supply cable in such a way that it restricts the power supply cable from moving toward the movable part of the pressure changing mechanism. Furthermore, in order to solve the above-mentioned problems, the image forming apparatus of the present invention is An image forming apparatus for forming an image on a recording material, An image forming unit that forms an unfixed image on the recording material, A fixing unit that fixes the aforementioned unfixed image onto a recording material and A door that can move between an open position, which opens the inside of the image forming apparatus to the outside, and a closed position, Equipped with The fixing unit is a fixing device of the present invention, The pressure changing mechanism is a link mechanism connected to the door, and is characterized by having a link mechanism that can switch between the pressurized state and the released state of the pressure changing mechanism in conjunction with the opening and closing operation of the door. [Effects of the Invention]

[0007] According to the present invention, it is possible to restrict the access of cables to the pressure changing mechanism with a simple configuration. [Brief explanation of the drawing]

[0008] [Figure 1] Perspective view of the fuser according to Embodiment 1 of the present invention [Figure 2] Cross-sectional view of an image forming apparatus [Figure 3] Cross-sectional view of the heating unit and pressurized rotating body of Embodiment 1 of the present invention. [Figure 4] Cross-sectional view of the fuser according to Embodiment 1 of the present invention [Figure 5]Exploded perspective view of the fixing device according to Example 1 of the present invention [Figure 6] Cross-sectional view of the fixing device according to Example 1 of the present invention [Figure 7] Exploded perspective view of the fixing device according to Example 1 of the present invention [Figure 8] Schematic diagram showing the layout of the heater electrodes according to Example 1 of the present invention [Figure 9] Explanatory drawing of the heater connector according to Example 1 of the present invention [Figure 10] Perspective view of the heater holder according to Example 2 of the present invention [Figure 11] Perspective view of the heater holder according to Example 3 of the present invention

Mode for Carrying Out the Invention

[0009] Hereinafter, with reference to the drawings, the mode for carrying out this invention will be exemplarily and detailedly described based on examples. However, the dimensions, materials, shapes, relative arrangements, etc. of the components described in this embodiment 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 this invention to the following embodiments. Also, although a plurality of features are described in the embodiment, not all of these plurality of features are essential to the invention, and the plurality of features may be arbitrarily combined. Fur Furthermore, in the accompanying drawings, the same or similar configurations are given the same reference numerals, and duplicate explanations are omitted.

[0010] <Example 1> The first embodiment of the present invention will be described in detail based on the drawings.

[0011] [Image forming apparatus] Figure 2 is a cross-sectional view showing the schematic configuration of a laser beam printer 1, which is an example of an electrophotographic image forming apparatus (image forming apparatus). In the following description, the left side of Figure 2 is defined as the front side of the laser beam printer 1, and the right side is defined as the rear side of the laser beam printer 1. The front side of the paper is defined as the right side of the laser beam printer 1, and the back side of the paper is defined as the left side of the laser beam printer 1. Also, the top and bottom sides of Figure 2 are defined as the top and bottom sides of the laser beam printer 1, respectively. When the laser beam printer 1 is placed on a horizontal surface, which is the usual assumed installation surface, the vertical direction coincides with the direction of gravity.

[0012] As shown in Figure 2, the laser beam printer 1 consists of a main unit 2 and a process cartridge 10, the process cartridge 10 being detachably installed in the main unit 2. The main unit 2 is equipped with a paper feed tray 3, a sheet feeding unit 4, a transport path P, an image forming unit 5, a fuser 6, a sheet discharge unit 7, a paper output tray 8, a laser scanner 9, and the like. The cartridge 10, on the other hand, is equipped with a photosensitive drum 11, a developing roller 12 as a developer carrier, and the like.

[0013] The main body of the device 2 is equipped with an opening / closing door 21, which serves as an opening / closing member, to close the opening 2A provided for attaching and detaching the process cartridge 10. The opening / closing door 21 is supported so as to be rotatable around a pivot axis 21a and is configured to move between a closed position that closes the opening 2A and an open position that opens the opening 2A (inside the main body of the device 2).

[0014] The sheet feeding unit 4 consists of a paper feed roller 41, a separation roller 42, a separation pad 42a, and a transport roller pair 43. Based on the print start signal, the sheet S, which is the recording material stored in the paper feed tray 3, is sent to the transport path P by the sheet feeding unit 4 and transported towards the image forming unit 5 via the registration roller pair 44.

[0015] When the sheet S is transported to a predetermined position, an image formation start signal is issued, and the image formation process begins. The photosensitive drum 11, which is rotated by a drive source (motor) (not shown), is uniformly charged to a predetermined potential by a charging means (not shown). After charging, the surface of the photosensitive drum 11 is exposed by a laser scanner 9 based on image information, and the charge in the exposed area is removed to form an electrostatic image. The toner in the process cartridge 10 is carried on the developing roller 12 and supplied to the photosensitive drum 11 according to the electrostatic latent image, developing the latent image. As a result, the latent image is made visible on the photosensitive drum 11 as a toner image.

[0016] The image forming unit 5 consists of a process cartridge 10 and a transfer roller 51 positioned opposite the photosensitive drum 11 of the process cartridge 10. When the sheet S, transported by the registration roller pair 44, reaches the image forming unit 5 and passes through the nip between the photosensitive drum 11 and the transfer roller 51, a voltage is applied to the transfer roller 51 from the main body 2 of the device, and the toner image on the photosensitive drum 11 is transferred to the sheet S as an unfixed image (unfixed toner image). Subsequently, the sheet S with the transferred toner image is transported to the fuser 6, which is equipped with a heating unit 61 and a pressurizing rotating body 62, as the fixing unit. When the sheet S passes through the nip between the heating unit 61 and the pressurizing rotating body 62, the unfixed image transferred on the sheet S is heated and pressurized and fixed to the surface of the sheet S. The sheet S with the fixed toner image is discharged to the output tray 8 via the sheet discharge unit 7.

[0017] [Fuser] The specific configuration of the fuser 6 (fusing device) will be explained using Figures 3 to 5. Figure 3 is a cross-sectional view of the heating unit 61 and the pressurizing rotating body 62. Figure 4 is a cross-sectional view of the fuser 6. Figure 5 is an exploded perspective view of the fuser 6.

[0018] As shown in Figure 3, the heating unit 61 of the fuser 6 comprises a heater 611, a holder 610, a stay 613, and a belt 614. The heater 611 has a flat plate shape extending in the left-right direction and has a first surface 611a and a second surface 611b opposite to the first surface 611a, with the first surface 611a being supported by the holder 610. Hereafter, the longitudinal direction of the heater 611 (the left-right direction of the laser beam printer 1) will also be referred to as the "longitudinal direction," and the width direction of the heater 611 perpendicular to the longitudinal direction will also be referred to as the "width direction."

[0019] The holder 610 is a heater holder that holds the heater 611 along its longitudinal direction. The holder 610 is made of a heat-resistant resin such as PPS or liquid crystal polymer, and has a guide surface 612a and a support wall 612b. The guide surface 612a contacts the inner circumferential surface 614a of the belt 614 to guide the belt 614, and the support wall 612b has a support surface 612b1 that supports the heater 611. The support surface 612b1 of the support wall 612b abuts against the first surface 611a of the heater 611. The stay 613 is a member that supports the holder 610, and is formed by bending a plate material with greater rigidity than the holder 610, for example, a steel plate with a thickness of 1.6 mm, into a roughly U-shape.

[0020] The belt 614 is an endless (cylindrical) fixing belt that is heat-resistant and flexible. For example, it may be made of a metal sleeve such as stainless steel coated with fluororesin, or made of laminated polyimide resin, silicone rubber, fluororesin, etc. Inside the belt 614 (the internal space of the belt 614 surrounded by the belt 614), a heater 611, a holder 610, and a stay 613 are arranged, and the belt 614 is configured to rotate around these. The inner circumferential surface 614a of the belt 614 is in contact with the second surface 611b of the heater 611.

[0021] [Pressurization mechanism] As shown in Figures 3 to 5, the pressurizing rotating body 62 is a pressurizing roller having a metal shaft 62a and a roller 62b made of an elastic material covering the shaft 62a, and it contacts the outer surface of the belt 614. The pressurizing rotating body 62 is pressed by the heater 611 via the belt 614. The pressurizing rotating body 62, together with the heater 611, sandwiches the belt 614, forming a fixed nip portion NP1 between itself and the belt 614 for nipping the sheet S and heating and pressurizing it. In other words, the pressurizing rotating body 62 heats and pressurizes the sheet S together with the heater 611 at the nip portion NP1.

[0022] The pressurized rotating body 62 is configured to rotate when a driving force is transmitted from a drive source provided by the image forming apparatus 1. As the pressurized rotating body 62 rotates, the belt 614 rotates passively due to the frictional force between the pressurized rotating body 62 or the sheet S sandwiched between the nip portion NP1. As a result, the sheet S on which the toner image has been transferred is transported between the pressurized rotating body 62 and the heated belt 614, and the toner image is heat-fixed.

[0023] As shown in Figure 4, the fuser 6 has a lower frame 63 that supports the heating unit 61 and the pressurizing rotating body 62, and an upper frame 64 that is located above the lower frame 63 and covers the heating unit 61.

[0024] The upper frame 64 is located downstream of the heating unit 61 and the pressurizing rotating body 62 in the sheet conveying direction, and serves as an upper sheet guide for the upper surface of the sheet S being conveyed along the conveying path P. It has a side 64a. The lower frame 63 has a lower sheet guide 63a that guides the lower surface of the sheet S being conveyed along the conveyance path P downstream of the heating unit 61 and the pressurizing rotating body 62 in the sheet conveyance direction.

[0025] The transport path P in the fuser 6 extends in a direction roughly aligned with the front-to-back direction and slopes upward as it moves from front to back. In other words, the sheet transport direction in the fuser 6 is roughly aligned with the front-to-back direction.

[0026] In this configuration, the lower frame 63 and the upper frame 64 are formed from non-conductive molded material.

[0027] As shown in Figure 5, the lower frame 63 supports the heating unit 61 and the pressurizing rotating body 62. The lower frame 63 has a pair of rails 63b at each of its longitudinal ends. The rails 63b support the holder 610 so that it can move in the thickness direction (Z direction) perpendicular to the longitudinal direction (X direction) and the width direction (Y direction) via transmission members 617a and 617b that transmit pressure to the stay 613. Hereafter, the thickness direction perpendicular to the longitudinal direction and the width direction will also be simply referred to as the "thickness direction".

[0028] The rail 63b is a columnar portion extending from the lower frame 63 in the thickness direction (Z direction). Pairs of rails 63b face each other in the width direction (Y direction). The opposing surfaces of the rails 63b engage with grooves 617a1 and 617b1 provided on the transmission members 617a and 617b, respectively. In this embodiment, the rail 63b is a columnar portion extending in the thickness direction, but it is not limited to the shape of this embodiment, as long as it is a shape that can support the holder 610 so that it can move in the thickness direction.

[0029] Furthermore, the pressurized rotating body 62 is rotatably held by the lower frame 63 via bearings 62c and 62d at both longitudinal ends of a metal shaft 62a. At this time, the position of bearing 62c is determined when a protrusion 62c1 on bearing 62c fits into a recess 63d1 on the lower frame 63. Similarly, the position of bearing 62d is determined when a protrusion 62d1 on bearing 62d fits into a recess 63d2 on the lower frame 63.

[0030] In this configuration, the bearings 62c and 62d are provided with protrusions 62c1 and 62d1, and the lower frame 63 is provided with recesses 63d1 and 63d2, but the relationship between protrusions and recesses is not limited to this. Also, the means for fixing the bearings 62c and 62d to the lower frame 63 is not limited to a protrusion-recess shape.

[0031] In this embodiment, the pressurizing rotating body 62 is configured to include a shaft 62a and a roller 62b, but it is not limited to this configuration, and can also be configured to include a pressurizing belt that is pressed against the heating roller by an elastic member.

[0032] [Pressure release mechanism] Figure 6(a) is a cross-sectional view of the fuser 6 in a pressurized state. Figure 6(b) is a cross-sectional view of the fuser 6 in a depressurized state. As shown in Figures 6(a) and 6(b), the fuser 6 further includes a pressure release mechanism 67 for releasing the nip pressure in the nip portion NP1 between the heating unit 61 and the pressurizing rotating body 62. The pressure release mechanism 67 is configured as a pressure changing mechanism to switch the pressure applied to the nip portion NP1 between a high-pressure pressurized state and a low-pressure depressurized state.

[0033] The pressure release mechanism 67 comprises a camshaft 671 and a cam 672. The lower frame 63 supports the pressure spring 653 and rotatably supports the pressure arm 652 and the cam 672. One end of the pressure spring 653 is connected to the lower frame 63, and the other end is connected to the pressure arm It is connected to the 652 and is configured to generate a predetermined biasing force between the lower frame 63 and the pressurizing arm 652 in response to the rotation of the pressurizing arm 652 relative to the lower frame 63.

[0034] The cams 672 are located at each of the longitudinal ends of the lower frame 63. Since the structure of one longitudinal side of the pressure release mechanism 67 and the structure of the other longitudinal side are substantially the same, the following description will mainly refer to the structure of one longitudinal side.

[0035] Figure 7 is an exploded perspective view of the fuser 6. As shown in Figure 7, the camshaft 671 extends in the longitudinal direction. The camshaft 671 is made of, for example, metal. Cams 672 are fixed to each axial end of the camshaft 671. The cams 672 rotate with the rotation of the camshaft 671. The lower frame 63 has support portions 63l that rotatably support the camshaft 671. The support portions 63l are located at one end and the other end of the lower frame 63 in the longitudinal direction. The support portions 63l have holes H that rotatably support the camshaft 671.

[0036] The upper frame 64 has grooves 64c that rotatably support the camshaft 671. The grooves 64c are located at one end and the other end of the upper frame 64 in the longitudinal direction. The camshaft 671 is held between the upper frame 64 and the lower frame 63.

[0037] The camshaft 671 is rotatably supported, and the cam 672 is capable of pressing the pressurizing arm 652 against the biasing force of the pressurizing spring 653.

[0038] [Fusing shutter] The fuser unit 6 is equipped with a fuser shutter 804 as shown in Figure 7. This is to prevent electric shock, burns, or image defects caused by contamination that could occur when the user accesses the nip section NP1, which consists of a heating unit 61 and a pressurizing rotating body 62.

[0039] The basic configuration of the fixed shutter 804 consists of a shutter link 803 and the fixed shutter 804. The shutter link 803 is supported coaxially with the camshaft 671 and rotates integrally with the camshaft 671 and cam 672.

[0040] The fixing shutter 804 is pivotably supported relative to the fixing unit 6, and the shutter shaft 804a engages with the link hole 803b of the shutter link 803. The shutter link 803 may be a single part or assembled from multiple parts.

[0041] The operation of switching the state of the pressure release mechanism 67 and the fixed shutter 804 described above is linked to the opening and closing operation of the opening / closing door 21. This linkage with the opening / closing door 21 is achieved, for example, by connecting the opening / closing door 21 and the link shaft 803a with an intermediate link (not shown). In conjunction with the rotational operation of the opening / closing door 21, the shutter link 803 and the cam 672 rotate together with the camshaft 671 in the CW or CCW direction.

[0042] When the opening / closing door 21 is in the closed position, the fuser 6 takes the pressurized state shown in Figure 6(a) via the link mechanism described above, and the fuser shutter 804 takes the released position. On the other hand, when the opening / closing door 21 is in the open position, the fuser 6 takes the depressurized state (separated state) shown in Figure 6(b) via the link mechanism described above, and the fuser shutter 804 takes the shielded position.

[0043] [Heater wiring] Figure 8 is a schematic diagram showing the layout of the heater electrodes. Figure 9(a) is a perspective view of the heater connectors in a separated state. Figure 9(b) is a perspective view of the heater connectors in a mounted state. As shown in Figures 8 to 9(b), the structure of the heater 611 consists of heating resistors 901a and 901b extending along the longitudinal direction of a plate-shaped substrate 900, with conductors 902a to 902c connected to both ends of the two heating resistors 901a and 901b.

[0044] One end of the conductor 902a is connected to the electrode 903a for the heating resistor, and the other end is connected to the heating resistor 901a. One end of the conductor 902b is connected to the heating resistor 901a, and the other end is connected to the heating resistor 901b. One end of the conductor 902c is connected to the heating resistor 901b, and the other end is connected to the electrode 903b for the heating resistor. Therefore, by supplying power between the electrodes 903a and 903b for the heating resistors, a heater circuit configuration is formed in which the heating resistors 901a and 901b heat up simultaneously.

[0045] Power is supplied to the heater 611 by the heater connector (hereinafter simply referred to as the connector) 800 and the power supply cables 201 to 203 connected to the connector 800. Cable 201 connects the connector 800 to the power supply unit 200. Cable 202 connects the connector 800 to the thermostat 613a. Cable 203 connects the thermostat 613a to the power supply unit 200. The thermostat 613a is a switch that shuts off the circuit when its temperature exceeds a threshold. If the heater 611 reaches a temperature higher than a certain threshold for any reason, the thermostat 613a activates and shuts off the circuit between the heater 611 and the power supply unit 200. This prevents the temperature of the heater 611 from rising above the threshold.

[0046] [Connector description] Figure 1(a) is a perspective view of the fuser unit 6. Figure 1(b) is a perspective view of the fuser unit 6. As shown in Figures 1(a), 1(b), 9(a), and 9(b), the connector 800 is attached to one end of the holder 610 in the longitudinal direction, from one side in the short direction of the heater 611 to the other side. The connector 800 is a power supply connector for supplying power to the heater 611, and is attached to the holder 610 so as to sandwich the holder 610 between the heater 611 and the connector 800, and is connected to the heater 611.

[0047] The connector 800 has a housing 904 and an arm portion 805 made from a non-conductive material such as resin, and contacts 802a and 802b made from a conductive material such as metal. The holder 610 has a connector cover 810 integrally molded at one end in the longitudinal direction of the holder 610 for housing the connector 800 (Figure 5). By inserting the connector 800 into the connector cover 810 in the connector mounting direction, the connector 800 can be housed in the connector cover 810 and mounted on the holder 610. In this embodiment, the connector 800 is configured to be detachable from the connector cover 810 in a direction that intersects both the longitudinal direction of the heater 611 and a direction perpendicular to the planar portion of the heater 611 (first surface 611a, second surface 611b). However, the direction in which the connector 800 can be attached to and detached from the connector cover 810 is not limited to the above direction.

[0048] In the installed state, the connector 800 is positioned in the width direction so that it fits between the first side wall 811a and the second side wall 811b of the connector cover 810. The width direction of the connector 800 is along the longitudinal direction of the heater 611. The connector 800 has a first side surface 800a and a second side surface 800b that intersect the width direction. The first side surface 800a is one end face of the connector 800 in the width direction and faces the first side wall 811a (first wall portion) of the connector cover 810 when the connector 800 is housed in the connector cover 810. The second side surface 800b is the other end face of the connector 800 in the width direction and faces the second side wall 811b (second wall portion) of the connector cover 810 when the connector 800 is housed in the connector cover 810.

[0049] When the connector 800 is mounted on the holder 610 so as to be housed in the connector cover 810, the contact 802a and electrode 903a (Figure 8) and the contact 802b and electrode 903b (Figure 8) come into contact. This enables power to be supplied from the power supply unit 200 to the heating resistors 901a and 901b via electrodes 903a and 903b.

[0050] Furthermore, the arm portion 805 is equipped with a protrusion 805a and a pressing portion 805b. The protrusion 805a overlaps with the stopper rib 801c in a direction perpendicular to it (the direction in which the connector 800 is attached to and detached from the connector cover 810) when installed, and acts as a stopper to prevent the connector 800 from coming off the connector cover 810. To remove the connector 800 from the connector cover 810, push the pressing portion 805b downwards while moving the connector 800 to the rear. The entire arm portion 805 elastically deforms downwards, eliminating the overlap between the protrusion 805a and the stopper rib 801c.

[0051] [Cable protection shape] As shown in Figures 9(a) and 9(b), the connector cover 810 is equipped with canopies 810a and 810b to protect the cables 201-203 from being caught in the wires. The connector 800 and cables 201-203 are positioned below the movable shutter link 803. The canopies 810a and 810b, which extend from the connector cover 810, are located between the cables 201-203 and the shutter link 803. The canopies 810a and 810b serve to separate the shutter link 803 and the cables 201-203 in the vertical direction to prevent the cables 201-203 from being caught and broken by the rotational movement of the shutter link 803.

[0052] The canopies 810a and 810b are extensions integrally provided on the connector cover 810 so as to overlap the cables 201-203 and the shutter link 803, respectively, when viewed in a direction perpendicular to the first surface 611a or the second surface 611b, which are the planar portions of the heater 611. The canopy 810a is a first extension that extends in the longitudinal direction of the heater 611 toward the side closer to the heater holder 610 than the first side wall 811a (first wall portion). The canopy 810b is a second extension that extends toward the upstream side in the mounting direction of the connector 800 toward the connector cover 810, toward the rear end of the connector 800.

[0053] The canopy 801a extends to the left of the first side wall 811a, thereby entering the space between cables 201 and 203, which are mainly routed to the left of connector 800, and the movable shutter link 803, thereby protecting cables 201 and 203. The canopy 801b extends to the rear of connector 800, thereby entering the space between the area of ​​cables 201-203 located behind connector 800 and the movable shutter link 803, thereby protecting cables 201-203.

[0054] In this embodiment, the canopy 810a has a rib shape extending to the left from the connector cover 810, and the canopy 810b has a rib shape extending to the rear; however, the shapes of the canopies 810a and 810b are not limited to these.

[0055] According to this embodiment, it is possible to restrict the access of cables 201 to 203 to the pressure release mechanism 67 with a simple and inexpensive configuration. This makes it possible to avoid the risk of cables 201 to 203 getting too close to the shutter link 803, which is a movable part of the fuser 6, and causing wire jamming.

[0056] <Example 2> A configuration for separating cables 201-203 and shutter link 803, with a shape different from the canopy shape described above, will be explained using Figures 10(a) and 10(b). Figures 10(a) and 10(b) are perspective views of the heater holder of Embodiment 2. In Embodiment 2, here in particular... Matters not explained here are the same as in Example 1, and therefore their explanations are omitted.

[0057] In Example 1, multiple canopies were provided to protect the cable, but it is also possible to configure the cable protection on the left and rear sides of the connector 800 with a single integrated shape, such as canopy 820a.

[0058] <Example 3> Furthermore, the means for separating cables 201-203 from the shutter link 803 is not limited to simply extending ribs from the top surface of the connector cover 830. As shown in Figures 11(a) and 11(b), cable holding shapes may be provided on the side surfaces of the connector cover 830. Figures 11(a) and 11(b) are perspective views of the heater holder of Embodiment 3. Matters in Embodiment 3 that are not specifically described here are the same as in Embodiments 1 and 2, and are therefore omitted from the explanation.

[0059] The connector cover 830 has a first side wall 831a and a second side wall 831b that extend in a direction intersecting the longitudinal direction of the heater 611. The second side wall 831b is located further from the heater holder 610 than the first side wall 831a in the longitudinal direction of the heater 611. The second side wall 831b is provided with a slit 834 that has an opening on the lower side, which is a cutout portion of the second side wall 831b to allow cables 202 and 203 to be locked in place. Cables 202 and 203 that are routed to the right side of the connector 800 are housed in the slit 834 to prevent them from coming close to the shutter link 803.

[0060] For cables 201 and 203 routed to the left side of connector 800, the movement of cables 201 and 203 is restricted by a hook 832 and a regulating rib 833. The hook 832 is located to the left of the first side wall 831a, that is, on the side closer to the heater holder 610 than the first side wall 831a in the longitudinal direction of the heater 611. The hook 832 has a first extension portion that extends in the longitudinal direction and a locking portion that bends downward from the tip of the extension portion in a direction intersecting the longitudinal direction, and is configured to hold cables 201 and 203 between itself and the first side wall 831a. By locking cables 201 and 203 to the hook 832, it is prevented that cables 201 and 203 move upward and approach the shutter link 803. In addition, a regulating rib 833 is provided to prevent cables 201 and 203 from easily falling off the hook 832.

[0061] The configurations of each of the above embodiments can be combined with each other.

[0062] The disclosure of embodiments of the present invention includes the following configurations. (Composition 1) A cylindrical fixing belt, A plate-shaped heater is disposed in the internal space of the fixing belt, A heater holder is disposed within the internal space of the fixing belt and holds the heater along its longitudinal direction, A power supply connector for supplying power to the heater, comprising a power supply connector connected to the heater so as to sandwich the heater and the heater holder, A pressure roller that contacts the outer circumferential surface of the fixing belt, which together with the heater clamps the fixing belt and forms a fixing nip portion between itself and the fixing belt, The aforementioned fixing nip portion has a pressure changing mechanism that can switch between a high-pressure state and a low-pressure state. In a fixing device that transports the recording material in the fixing nip section and fixes the toner image formed on the recording material to the recording material, The heater holder has a connector cover integrally molded to house the power supply connector. The connector cover contains the power supply cable extending from the power supply connector and the pressure transformer. A fixing device characterized by having an extension portion that enters the space between the movable part of the mechanism and the power supply cable and the movable part when viewed in a direction perpendicular to the flat surface of the heater. (Configuration 2) The connector cover has a first wall portion and a second wall portion that intersect the longitudinal direction, The power supply connector has a first side facing the first wall and a second side facing the second wall. The fixing device according to configuration 1, characterized in that when the power supply connector is attached to the heater, the power supply connector is located between the first wall portion and the second wall portion of the connector cover. (Composition 3) The connector cover is provided at one end of the heater holder in the longitudinal direction, The second wall portion is located further from the heater holder than the first wall portion in the longitudinal direction. The fixing device according to configuration 2, characterized in that the extended portion includes a first extended portion that extends toward the side closer to the heater holder than the first wall portion in the longitudinal direction. (Composition 4) The fixing device according to configuration 3, characterized in that the extended portion includes a second extended portion that extends upstream in the mounting direction from the rear end of the power supply connector in the mounting direction of the power supply connector to the connector cover. (Composition 5) The fixing device according to configuration 3 or 4, characterized in that the first extension portion has a locking portion that extends in a direction intersecting the longitudinal direction so as to sandwich the power supply connector between itself and the first wall portion. (Composition 6) A cylindrical fixing belt, A plate-shaped heater is disposed in the internal space of the fixing belt, A heater holder is disposed within the internal space of the fixing belt and holds the heater along its longitudinal direction, A power supply connector for supplying power to the heater, comprising a power supply connector connected to the heater so as to sandwich the heater and the heater holder, A pressure roller that contacts the outer circumferential surface of the fixing belt, which together with the heater clamps the fixing belt and forms a fixing nip portion between itself and the fixing belt, The aforementioned fixing nip portion has a pressure changing mechanism that can switch between a high-pressure state and a low-pressure state. In a fixing device that transports the recording material in the fixing nip section and fixes the toner image formed on the recording material to the recording material, The heater holder has a connector cover integrally molded to house the power supply connector. The connector cover has a retaining shape for holding the power supply cable extending from the power supply connector, The fixing device is characterized in that the holding shape holds the power supply cable in such a way that it restricts the power supply cable from moving toward the movable part of the pressure changing mechanism. (Composition 7) The connector cover has a first wall portion and a second wall portion that intersect the longitudinal direction, The power supply connector has a first side facing the first wall and a second side facing the second wall. The configuration 6 is characterized in that when the power supply connector is attached to the heater, the power supply connector is positioned between the first wall and the second wall of the connector cover. Fixing device. (Composition 8) The connector cover is provided at one end of the heater holder in the longitudinal direction, The second wall portion is located further from the heater holder than the first wall portion in the longitudinal direction. The fixing device according to configuration 7, characterized in that the holding shape includes a locking portion that holds the power supply connector between itself and the first wall portion on the side closer to the heater holder than the first wall portion in the longitudinal direction. (Composition 9) The fixing device according to configuration 7 or 8, characterized in that the retaining shape includes a slit portion formed by cutting out a part of the second wall portion so that the power supply cable can be locked. (Composition 10) The fixing device according to any one of configurations 1 to 9, characterized in that the power supply connector is detachable from the connector cover in a direction that intersects both the longitudinal direction and the direction perpendicular to the planar portion of the heater. (Composition 11) An image forming apparatus for forming an image on a recording material, An image forming unit that forms an unfixed image on the recording material, A fixing unit that fixes the aforementioned unfixed image onto a recording material and A door that can move between an open position, which opens the inside of the image forming apparatus to the outside, and a closed position, Equipped with The fixing unit is a fixing device according to any one of the configurations 1 to 10. The image forming apparatus is characterized in that the pressure changing mechanism is a link mechanism connected to the door, and the link mechanism is capable of switching between the pressurized state and the released state of the pressure changing mechanism in conjunction with the opening and closing operation of the door. [Explanation of symbols]

[0063] 6…Fuser, 61…Heating unit, 610…Heater holder, 611…Heater, 613…Stay, 614…Belt, 62…Pressurizing rotating body, 67…Pressure release mechanism, 200…Power supply unit, 201, 202, 203…Cable, 800…Connector, 803…Shutter link, 810, 820, 830…Connector cover, 810a, 810b, 820a…Eaves, 811a, 821a, 831a…First side wall, 811b, 831b…Second side wall

Claims

1. A cylindrical fixing belt, A plate-shaped heater is disposed in the internal space of the fixing belt, A heater holder is disposed within the internal space of the fixing belt and holds the heater along its longitudinal direction, A power supply connector for supplying power to the heater, comprising a power supply connector connected to the heater so as to sandwich the heater and the heater holder, A pressure roller that contacts the outer circumferential surface of the fixing belt, which together with the heater clamps the fixing belt and forms a fixing nip portion between itself and the fixing belt, The aforementioned fixing nip portion has a pressure changing mechanism that can switch between a high-pressure state and a low-pressure state. In a fixing device that transports the recording material in the fixing nip section and fixes the toner image formed on the recording material to the recording material, The heater holder has a connector cover integrally molded to house the power supply connector. The fixing device is characterized in that the connector cover is provided with an extension that fits into the space between the power supply cable extending from the power supply connector and the movable part of the pressure changing mechanism, and overlaps the power supply cable and the movable part when viewed in a direction perpendicular to the flat surface of the heater.

2. The connector cover has a first wall portion and a second wall portion that intersect the longitudinal direction, The power supply connector has a first side facing the first wall and a second side facing the second wall. The fixing device according to claim 1, characterized in that when the power supply connector is attached to the heater, the power supply connector is located between the first wall and the second wall of the connector cover.

3. The connector cover is provided at one end of the heater holder in the longitudinal direction, The second wall portion is located further from the heater holder than the first wall portion in the longitudinal direction. The fixing device according to claim 2, characterized in that the extended portion includes a first extended portion that extends toward the side closer to the heater holder than the first wall portion in the longitudinal direction.

4. The fixing device according to claim 3, characterized in that the extended portion includes a second extended portion that extends upstream in the mounting direction from the rear end of the power supply connector in the mounting direction of the power supply connector to the connector cover.

5. The fixing device according to claim 3, characterized in that the first extension portion has a locking portion that extends in a direction intersecting the longitudinal direction so as to sandwich the power supply connector between itself and the first wall portion.

6. A cylindrical fixing belt, A plate-shaped heater is disposed in the internal space of the fixing belt, A heater holder is disposed within the internal space of the fixing belt and holds the heater along its longitudinal direction, A power supply connector for supplying power to the heater, comprising a power supply connector connected to the heater so as to sandwich the heater and the heater holder, A pressure roller that contacts the outer circumferential surface of the fixing belt, and together with the heater, the fixing belt A pressure roller that sandwiches the belt and forms a fixing nip portion between itself and the fixing belt, The aforementioned fixing nip portion has a pressure changing mechanism that can switch between a high-pressure state and a low-pressure state. In a fixing device that transports the recording material in the fixing nip section and fixes the toner image formed on the recording material to the recording material, The heater holder has a connector cover integrally molded to house the power supply connector. The connector cover has a retaining shape for holding the power supply cable extending from the power supply connector, The fixing device is characterized in that the holding shape holds the power supply cable in such a way that it restricts the power supply cable from moving toward the movable part of the pressure changing mechanism.

7. The connector cover has a first wall portion and a second wall portion that intersect the longitudinal direction, The power supply connector has a first side facing the first wall and a second side facing the second wall. The fixing device according to claim 6, characterized in that when the power supply connector is attached to the heater, the power supply connector is located between the first wall and the second wall of the connector cover.

8. The connector cover is provided at one end of the heater holder in the longitudinal direction, The second wall portion is located further from the heater holder than the first wall portion in the longitudinal direction. The fixing device according to claim 7, characterized in that the holding shape includes a locking portion that holds the power supply connector between itself and the first wall portion on the side closer to the heater holder than the first wall portion in the longitudinal direction.

9. The fixing device according to claim 8, characterized in that the retaining shape includes a slit portion formed by cutting out a part of the second wall portion so that the power supply cable can be locked in place.

10. The fixing device according to claim 1 or 6, characterized in that the power supply connector is detachable from the connector cover in a direction that intersects both the longitudinal direction and the direction perpendicular to the planar portion of the heater.

11. An image forming apparatus for forming an image on a recording material, An image forming unit that forms an unfixed image on the recording material, A fixing unit that fixes the aforementioned unfixed image onto a recording material and A door that can move between an open position, which opens the inside of the image forming apparatus to the outside, and a closed position, Equipped with The fixing unit is the fixing device according to claim 1 or 6, The image forming apparatus is characterized in that the pressure changing mechanism is a link mechanism connected to the door, and the link mechanism is capable of switching between the pressurized state and the separated state of the pressure changing mechanism in conjunction with the opening and closing operation of the door.

Images